Add cross-compilation Makefile targets and tar-based releases.

Revamp the build system to be more inline with other Prometheus exporters.
Notably add Darwin and Windows build targets, and add support for releases
using tar files.

tools/vendor/github.com/GoASTScanner/gas/Dockerfile

@@ -0,0 +1,23 @@
+# Docker version must be 17.05 or higher to allow multistage build
+# See build and run instructions in README.md
+
+# Builds Gas for utilization
+FROM golang:1.8.1-alpine as builder
+ENV workspace /go/src/github.com/GoASTScanner/gas
+ENV GOPATH /go
+COPY . $workspace
+WORKDIR $workspace
+
+RUN go vet $(go list ./... | grep -v /vendor/)
+RUN CGO_ENABLED=0 go build -o gas .
+
+########################################################
+
+# Runs Gas on all Go files in the current directory when 
+# 'docker run' command in README is given
+FROM alpine:3.6
+
+COPY --from=builder /go/src/github.com/GoASTScanner/gas/gas /
+
+# Mounted directory should be placed into the workdir
+CMD /gas $(find . -path ./vendor -prune -o -type f -name "*.go")

tools/vendor/github.com/GoASTScanner/gas/README.md

@@ -112,3 +112,20 @@ file. The output format is controlled by the '-fmt' flag, and the output file is
 # Write output in json format to results.json
 $ gas -fmt=json -out=results.json *.go
 ```
+
+### Docker container
+
+A Dockerfile is included with the Gas source code to provide a container that 
+allows users to easily run Gas on their code. It builds Gas, then runs it on 
+all Go files in your current directory. Use the following commands to build 
+and run locally:
+
+To build: (run command in cloned Gas source code directory)
+          docker build --build-arg http_proxy --build-arg https_proxy
+          --build-arg no_proxy -t goastscanner/gas:latest .
+
+To run:  (run command in desired directory with Go files)
+          docker run -v $PWD:$PWD --workdir $PWD goastscanner/gas:latest
+
+Note: Docker version 17.05 or later is required (to permit multistage build).
+```

tools/vendor/github.com/alecthomas/gometalinter/README.md

@@ -19,7 +19,6 @@
     - [2. Analyse the debug output](#2-analyse-the-debug-output)
     - [3. Report an issue.](#3-report-an-issue)
   - [How do I filter issues between two git refs?](#how-do-i-filter-issues-between-two-git-refs)
-- [Details](#details)
 - [Checkstyle XML format](#checkstyle-xml-format)
 
 <!-- /MarkdownTOC -->
@@ -57,12 +56,13 @@ It is intended for use with editor/IDE integration.
 - [go vet](https://golang.org/cmd/vet/) - Reports potential errors that otherwise compile.
 - [go tool vet --shadow](https://golang.org/cmd/vet/#hdr-Shadowed_variables) - Reports variables that may have been unintentionally shadowed.
 - [gotype](https://golang.org/x/tools/cmd/gotype) - Syntactic and semantic analysis similar to the Go compiler.
+- [gotype -x](https://golang.org/x/tools/cmd/gotype) - Syntactic and semantic analysis in external test packages (similar to the Go compiler).
 - [deadcode](https://github.com/tsenart/deadcode) - Finds unused code.
 - [gocyclo](https://github.com/alecthomas/gocyclo) - Computes the cyclomatic complexity of functions.
 - [golint](https://github.com/golang/lint) - Google's (mostly stylistic) linter.
 - [varcheck](https://github.com/opennota/check) - Find unused global variables and constants.
 - [structcheck](https://github.com/opennota/check) - Find unused struct fields.
-- [aligncheck](https://github.com/opennota/check) - Warn about un-optimally aligned structures.
+- [maligned](https://github.com/mdempsky/maligned) -  Detect structs that would take less memory if their fields were sorted.
 - [errcheck](https://github.com/kisielk/errcheck) - Check that error return values are used.
 - [megacheck](https://github.com/dominikh/go-tools/tree/master/cmd/megacheck) - Run staticcheck, gosimple and unused, sharing work.
 - [dupl](https://github.com/mibk/dupl) - Reports potentially duplicated code.
@@ -81,6 +81,7 @@ Disabled by default (enable with `--enable=<linter>`):
 - [gosimple](https://github.com/dominikh/go-tools/tree/master/cmd/gosimple) - Report simplifications in code.
 - [lll](https://github.com/walle/lll) - Report long lines (see `--line-length=N`).
 - [misspell](https://github.com/client9/misspell) - Finds commonly misspelled English words.
+- [nakedret](https://github.com/alexkohler/nakedret) - Finds naked returns.
 - [unparam](https://github.com/mvdan/unparam) - Find unused function parameters.
 - [unused](https://github.com/dominikh/go-tools/tree/master/cmd/unused) - Find unused variables.
 - [safesql](https://github.com/stripe/safesql) - Finds potential SQL injection vulnerabilities.
@@ -91,14 +92,15 @@ Additional linters can be added through the command line with `--linter=NAME:COM
 ## Configuration file
 
 gometalinter now supports a JSON configuration file which can be loaded via
-`--config=<file>`. The format of this file is determined by the Config struct
-in `config.go`.
+`--config=<file>`. The format of this file is determined by the `Config` struct
+in [config.go](https://github.com/alecthomas/gometalinter/blob/master/config.go).
 
 The configuration file mostly corresponds to command-line flags, with the following exceptions:
 
 - Linters defined in the configuration file will overlay existing definitions, not replace them.
 - "Enable" defines the exact set of linters that will be enabled (default
-  linters are disabled).
+  linters are disabled). `--help` displays the list of default linters with the exact names
+  you must use.
 
 Here is an example configuration file:
 
@@ -108,6 +110,34 @@ Here is an example configuration file:
 }
 ```
 
+### Adding Custom linters
+
+Linters can be added and customized from the config file using the `Linters` field.
+Linters supports the following fields:
+
+* `Command` - the path to the linter binary and any default arguments
+* `Pattern` - a regular expression used to parse the linter output
+* `IsFast` - if the linter should be run when the `--fast` flag is used
+* `PartitionStrategy` - how paths args should be passed to the linter command:
+  * `directories` - call the linter once with a list of all the directories
+  * `files` - call the linter once with a list of all the files
+  * `packages` - call the linter once with a list of all the package paths
+  * `files-by-package` - call the linter once per package with a list of the
+    files in the package.
+  * `single-directory` - call the linter once per directory
+
+The config for default linters can be overridden by using the name of the
+linter.
+
+Additional linters can be configured via the command line using the format
+`NAME:COMMAND:PATTERN`.
+
+Example:
+
+```
+$ gometalinter --linter='vet:go tool vet -printfuncs=Infof,Debugf,Warningf,Errorf:PATH:LINE:MESSAGE' .
+```
+
 ## Installing
 
 There are two options for installing gometalinter.
@@ -171,7 +201,8 @@ Install all known linters:
 $ gometalinter --install
 Installing:
   structcheck
-  aligncheck
+  maligned
+  nakedret
   deadcode
   gocyclo
   ineffassign
@@ -308,21 +339,6 @@ gometalinter |& revgrep master        # Show issues between master and HEAD (or
 gometalinter |& revgrep origin/master # Show issues that haven't been pushed.
 ```
 
-## Details
-
-Additional linters can be configured via the command line:
-
-```
-$ gometalinter --linter='vet:go tool vet -printfuncs=Infof,Debugf,Warningf,Errorf {path}:PATH:LINE:MESSAGE' .
-stutter.go:21:15:warning: error return value not checked (defer a.Close()) (errcheck)
-stutter.go:22:15:warning: error return value not checked (defer a.Close()) (errcheck)
-stutter.go:27:6:warning: error return value not checked (doit()           // test for errcheck) (errcheck)
-stutter.go:9::warning: unused global variable unusedGlobal (varcheck)
-stutter.go:13::warning: unused struct field MyStruct.Unused (structcheck)
-stutter.go:12:6:warning: exported type MyStruct should have comment or be unexported (golint)
-stutter.go:16:6:warning: exported type PublicUndocumented should have comment or be unexported (deadcode)
-```
-
 ## Checkstyle XML format
 
 `gometalinter` supports [checkstyle](http://checkstyle.sourceforge.net/)

tools/vendor/github.com/alecthomas/gometalinter/aggregate.go

@@ -5,27 +5,21 @@ import (
 	"strings"
 )
 
-type (
-	issueKey struct {
-		path      string
-		line, col int
-		message   string
-	}
-
-	multiIssue struct {
-		*Issue
-		linterNames []string
-	}
-)
-
-func maybeAggregateIssues(issues chan *Issue) chan *Issue {
-	if !config.Aggregate {
-		return issues
-	}
-	return aggregateIssues(issues)
+type issueKey struct {
+	path      string
+	line, col int
+	message   string
 }
 
-func aggregateIssues(issues chan *Issue) chan *Issue {
+type multiIssue struct {
+	*Issue
+	linterNames []string
+}
+
+// AggregateIssueChan reads issues from a channel, aggregates issues which have
+// the same file, line, vol, and message, and returns aggregated issues on
+// a new channel.
+func AggregateIssueChan(issues chan *Issue) chan *Issue {
 	out := make(chan *Issue, 1000000)
 	issueMap := make(map[issueKey]*multiIssue)
 	go func() {

tools/vendor/github.com/alecthomas/gometalinter/checkstyle.go

@@ -4,7 +4,7 @@ import (
 	"encoding/xml"
 	"fmt"
 
-	"gopkg.in/alecthomas/kingpin.v3-unstable"
+	kingpin "gopkg.in/alecthomas/kingpin.v3-unstable"
 )
 
 type checkstyleOutput struct {

tools/vendor/github.com/alecthomas/gometalinter/config.go

@@ -8,12 +8,12 @@ import (
 )
 
 // Config for gometalinter. This can be loaded from a JSON file with --config.
-type Config struct { // nolint: aligncheck
-	// A map of linter name to "<command>:<pattern>".
+type Config struct { // nolint: maligned
+	// A map from linter name -> <LinterConfig|string>.
 	//
-	// <command> should always include {path} as the target directory to execute. Globs in <command>
-	// are expanded by gometalinter (not by the shell).
-	Linters map[string]string
+	// For backwards compatibility, the value stored in the JSON blob can also
+	// be a string of the form "<command>:<pattern>".
+	Linters map[string]StringOrLinterConfig
 
 	// The set of linters that should be enabled.
 	Enable  []string
@@ -51,6 +51,35 @@ type Config struct { // nolint: aligncheck
 	EnableGC        bool
 	Aggregate       bool
 	EnableAll       bool
+
+	// Warn if a nolint directive was never matched to a linter issue
+	WarnUnmatchedDirective bool
+
+	formatTemplate *template.Template
+}
+
+type StringOrLinterConfig LinterConfig
+
+func (c *StringOrLinterConfig) UnmarshalJSON(raw []byte) error {
+	var linterConfig LinterConfig
+	// first try to un-marshall directly into struct
+	origErr := json.Unmarshal(raw, &linterConfig)
+	if origErr == nil {
+		*c = StringOrLinterConfig(linterConfig)
+		return nil
+	}
+
+	// i.e. bytes didn't represent the struct, treat them as a string
+	var linterSpec string
+	if err := json.Unmarshal(raw, &linterSpec); err != nil {
+		return origErr
+	}
+	linter, err := parseLinterConfigSpec("", linterSpec)
+	if err != nil {
+		return err
+	}
+	*c = StringOrLinterConfig(linter)
+	return nil
 }
 
 type jsonDuration time.Duration
@@ -70,17 +99,16 @@ func (td *jsonDuration) Duration() time.Duration {
 	return time.Duration(*td)
 }
 
-// TODO: should be a field on Config struct
-var formatTemplate = &template.Template{}
-
 var sortKeys = []string{"none", "path", "line", "column", "severity", "message", "linter"}
 
 // Configuration defaults.
 var config = &Config{
-	Format: "{{.Path}}:{{.Line}}:{{if .Col}}{{.Col}}{{end}}:{{.Severity}}: {{.Message}} ({{.Linter}})",
+	Format: DefaultIssueFormat,
 
+	Linters: map[string]StringOrLinterConfig{},
 	Severity: map[string]string{
 		"gotype":  "error",
+		"gotypex": "error",
 		"test":    "error",
 		"testify": "error",
 		"vet":     "error",

tools/vendor/github.com/alecthomas/gometalinter/directives.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"fmt"
 	"go/ast"
 	"go/parser"
 	"go/token"
@@ -14,6 +15,7 @@ type ignoredRange struct {
 	col        int
 	start, end int
 	linters    []string
+	matched    bool
 }
 
 func (i *ignoredRange) matches(issue *Issue) bool {
@@ -35,6 +37,14 @@ func (i *ignoredRange) near(col, start int) bool {
 	return col == i.col && i.end == start-1
 }
 
+func (i *ignoredRange) String() string {
+	linters := strings.Join(i.linters, ",")
+	if len(i.linters) == 0 {
+		linters = "all"
+	}
+	return fmt.Sprintf("%s:%d-%d", linters, i.start, i.end)
+}
+
 type ignoredRanges []*ignoredRange
 
 func (ir ignoredRanges) Len() int           { return len(ir) }
@@ -66,12 +76,43 @@ func (d *directiveParser) IsIgnored(issue *Issue) bool {
 	d.lock.Unlock()
 	for _, r := range ranges {
 		if r.matches(issue) {
+			debug("nolint: matched %s to issue %s", r, issue)
+			r.matched = true
 			return true
 		}
 	}
 	return false
 }
 
+// Unmatched returns all the ranges which were never used to ignore an issue
+func (d *directiveParser) Unmatched() map[string]ignoredRanges {
+	unmatched := map[string]ignoredRanges{}
+	for path, ranges := range d.files {
+		for _, ignore := range ranges {
+			if !ignore.matched {
+				unmatched[path] = append(unmatched[path], ignore)
+			}
+		}
+	}
+	return unmatched
+}
+
+// LoadFiles from a list of directories
+func (d *directiveParser) LoadFiles(paths []string) error {
+	d.lock.Lock()
+	defer d.lock.Unlock()
+	filenames, err := pathsToFileGlobs(paths)
+	if err != nil {
+		return err
+	}
+	for _, filename := range filenames {
+		ranges := d.parseFile(filename)
+		sort.Sort(ranges)
+		d.files[filename] = ranges
+	}
+	return nil
+}
+
 // Takes a set of ignoredRanges, determines if they immediately precede a statement
 // construct, and expands the range to include that construct. Why? So you can
 // precede a function or struct with //nolint
@@ -150,7 +191,28 @@ func filterIssuesViaDirectives(directives *directiveParser, issues chan *Issue)
 				out <- issue
 			}
 		}
+
+		if config.WarnUnmatchedDirective {
+			for _, issue := range warnOnUnusedDirective(directives) {
+				out <- issue
+			}
+		}
 		close(out)
 	}()
 	return out
 }
+
+func warnOnUnusedDirective(directives *directiveParser) []*Issue {
+	out := []*Issue{}
+	for path, ranges := range directives.Unmatched() {
+		for _, ignore := range ranges {
+			issue, _ := NewIssue("nolint", config.formatTemplate)
+			issue.Path = path
+			issue.Line = ignore.start
+			issue.Col = ignore.col
+			issue.Message = "nolint directive did not match any issue"
+			out = append(out, issue)
+		}
+	}
+	return out
+}

tools/vendor/github.com/alecthomas/gometalinter/execute.go

@@ -8,14 +8,13 @@ import (
 	"path/filepath"
 	"reflect"
 	"regexp"
-	"sort"
 	"strconv"
 	"strings"
 	"sync"
 	"time"
 
 	"github.com/google/shlex"
-	"gopkg.in/alecthomas/kingpin.v3-unstable"
+	kingpin "gopkg.in/alecthomas/kingpin.v3-unstable"
 )
 
 type Vars map[string]string
@@ -41,34 +40,8 @@ func (v Vars) Replace(s string) string {
 	return s
 }
 
-// Severity of linter message.
-type Severity string
-
-// Linter message severity levels.
-const ( // nolint: deadcode
-	Error   Severity = "error"
-	Warning Severity = "warning"
-)
-
-type Issue struct {
-	Linter   string   `json:"linter"`
-	Severity Severity `json:"severity"`
-	Path     string   `json:"path"`
-	Line     int      `json:"line"`
-	Col      int      `json:"col"`
-	Message  string   `json:"message"`
-}
-
-func (i *Issue) String() string {
-	buf := new(bytes.Buffer)
-	err := formatTemplate.Execute(buf, i)
-	kingpin.FatalIfError(err, "Invalid output format")
-	return buf.String()
-}
-
 type linterState struct {
 	*Linter
-	paths    []string
 	issues   chan *Issue
 	vars     Vars
 	exclude  *regexp.Regexp
@@ -76,26 +49,34 @@ type linterState struct {
 	deadline <-chan time.Time
 }
 
-func (l *linterState) Partitions() ([][]string, error) {
-	command := l.vars.Replace(l.Command)
-	cmdArgs, err := parseCommand(command)
+func (l *linterState) Partitions(paths []string) ([][]string, error) {
+	cmdArgs, err := parseCommand(l.command())
 	if err != nil {
 		return nil, err
 	}
-	parts, err := l.Linter.PartitionStrategy(cmdArgs, l.paths)
+	parts, err := l.Linter.PartitionStrategy(cmdArgs, paths)
 	if err != nil {
 		return nil, err
 	}
 	return parts, nil
 }
 
+func (l *linterState) command() string {
+	return l.vars.Replace(l.Command)
+}
+
 func runLinters(linters map[string]*Linter, paths []string, concurrency int, exclude, include *regexp.Regexp) (chan *Issue, chan error) {
 	errch := make(chan error, len(linters))
 	concurrencych := make(chan bool, concurrency)
 	incomingIssues := make(chan *Issue, 1000000)
-	processedIssues := filterIssuesViaDirectives(
-		newDirectiveParser(),
-		maybeSortIssues(maybeAggregateIssues(incomingIssues)))
+
+	directiveParser := newDirectiveParser()
+	if config.WarnUnmatchedDirective {
+		directiveParser.LoadFiles(paths)
+	}
+
+	processedIssues := maybeSortIssues(filterIssuesViaDirectives(
+		directiveParser, maybeAggregateIssues(incomingIssues)))
 
 	vars := Vars{
 		"duplthreshold":    fmt.Sprintf("%d", config.DuplThreshold),
@@ -105,43 +86,46 @@ func runLinters(linters map[string]*Linter, paths []string, concurrency int, exc
 		"min_occurrences":  fmt.Sprintf("%d", config.MinOccurrences),
 		"min_const_length": fmt.Sprintf("%d", config.MinConstLength),
 		"tests":            "",
+		"not_tests":        "true",
 	}
 	if config.Test {
-		vars["tests"] = "-t"
+		vars["tests"] = "true"
+		vars["not_tests"] = ""
 	}
 
 	wg := &sync.WaitGroup{}
+	id := 1
 	for _, linter := range linters {
 		deadline := time.After(config.Deadline.Duration())
 		state := &linterState{
 			Linter:   linter,
 			issues:   incomingIssues,
-			paths:    paths,
 			vars:     vars,
 			exclude:  exclude,
 			include:  include,
 			deadline: deadline,
 		}
 
-		partitions, err := state.Partitions()
+		partitions, err := state.Partitions(paths)
 		if err != nil {
 			errch <- err
 			continue
 		}
 		for _, args := range partitions {
 			wg.Add(1)
+			concurrencych <- true
 			// Call the goroutine with a copy of the args array so that the
 			// contents of the array are not modified by the next iteration of
 			// the above for loop
-			go func(args []string) {
-				concurrencych <- true
-				err := executeLinter(state, args)
+			go func(id int, args []string) {
+				err := executeLinter(id, state, args)
 				if err != nil {
 					errch <- err
 				}
 				<-concurrencych
 				wg.Done()
-			}(append(args))
+			}(id, args)
+			id++
 		}
 	}
 
@@ -153,13 +137,14 @@ func runLinters(linters map[string]*Linter, paths []string, concurrency int, exc
 	return processedIssues, errch
 }
 
-func executeLinter(state *linterState, args []string) error {
+func executeLinter(id int, state *linterState, args []string) error {
 	if len(args) == 0 {
 		return fmt.Errorf("missing linter command")
 	}
 
 	start := time.Now()
-	debug("executing %s", strings.Join(args, " "))
+	dbg := namespacedDebug(fmt.Sprintf("[%s.%d]: ", state.Name, id))
+	dbg("executing %s", strings.Join(args, " "))
 	buf := bytes.NewBuffer(nil)
 	command := args[0]
 	cmd := exec.Command(command, args[1:]...) // nolint: gas
@@ -191,12 +176,12 @@ func executeLinter(state *linterState, args []string) error {
 	}
 
 	if err != nil {
-		debug("warning: %s returned %s: %s", command, err, buf.String())
+		dbg("warning: %s returned %s: %s", command, err, buf.String())
 	}
 
-	processOutput(state, buf.Bytes())
+	processOutput(dbg, state, buf.Bytes())
 	elapsed := time.Since(start)
-	debug("%s linter took %s", state.Name, elapsed)
+	dbg("%s linter took %s", state.Name, elapsed)
 	return nil
 }
 
@@ -216,10 +201,10 @@ func parseCommand(command string) ([]string, error) {
 }
 
 // nolint: gocyclo
-func processOutput(state *linterState, out []byte) {
+func processOutput(dbg debugFunction, state *linterState, out []byte) {
 	re := state.regex
 	all := re.FindAllSubmatchIndex(out, -1)
-	debug("%s hits %d: %s", state.Name, len(all), state.Pattern)
+	dbg("%s hits %d: %s", state.Name, len(all), state.Pattern)
 
 	cwd, err := os.Getwd()
 	if err != nil {
@@ -239,7 +224,9 @@ func processOutput(state *linterState, out []byte) {
 			group = append(group, fragment)
 		}
 
-		issue := &Issue{Line: 1, Linter: state.Linter.Name}
+		issue, err := NewIssue(state.Linter.Name, config.formatTemplate)
+		kingpin.FatalIfError(err, "Invalid output format")
+
 		for i, name := range re.SubexpNames() {
 			if group[i] == nil {
 				continue
@@ -275,8 +262,6 @@ func processOutput(state *linterState, out []byte) {
 		}
 		if sev, ok := config.Severity[state.Name]; ok {
 			issue.Severity = Severity(sev)
-		} else {
-			issue.Severity = Warning
 		}
 		if state.exclude != nil && state.exclude.MatchString(issue.String()) {
 			continue
@@ -319,66 +304,16 @@ func resolvePath(path string) string {
 	return path
 }
 
-type sortedIssues struct {
-	issues []*Issue
-	order  []string
-}
-
-func (s *sortedIssues) Len() int      { return len(s.issues) }
-func (s *sortedIssues) Swap(i, j int) { s.issues[i], s.issues[j] = s.issues[j], s.issues[i] }
-
-// nolint: gocyclo
-func (s *sortedIssues) Less(i, j int) bool {
-	l, r := s.issues[i], s.issues[j]
-	for _, key := range s.order {
-		switch key {
-		case "path":
-			if l.Path > r.Path {
-				return false
-			}
-		case "line":
-			if l.Line > r.Line {
-				return false
-			}
-		case "column":
-			if l.Col > r.Col {
-				return false
-			}
-		case "severity":
-			if l.Severity > r.Severity {
-				return false
-			}
-		case "message":
-			if l.Message > r.Message {
-				return false
-			}
-		case "linter":
-			if l.Linter > r.Linter {
-				return false
-			}
-		}
-	}
-	return true
-}
-
 func maybeSortIssues(issues chan *Issue) chan *Issue {
 	if reflect.DeepEqual([]string{"none"}, config.Sort) {
 		return issues
 	}
-	out := make(chan *Issue, 1000000)
-	sorted := &sortedIssues{
-		issues: []*Issue{},
-		order:  config.Sort,
-	}
-	go func() {
-		for issue := range issues {
-			sorted.issues = append(sorted.issues, issue)
-		}
-		sort.Sort(sorted)
-		for _, issue := range sorted.issues {
-			out <- issue
-		}
-		close(out)
-	}()
-	return out
+	return SortIssueChan(issues, config.Sort)
+}
+
+func maybeAggregateIssues(issues chan *Issue) chan *Issue {
+	if !config.Aggregate {
+		return issues
+	}
+	return AggregateIssueChan(issues)
 }

tools/vendor/github.com/alecthomas/gometalinter/issue.go

@@ -0,0 +1,114 @@
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"io/ioutil"
+	"sort"
+	"strings"
+	"text/template"
+)
+
+// DefaultIssueFormat used to print an issue
+const DefaultIssueFormat = "{{.Path}}:{{.Line}}:{{if .Col}}{{.Col}}{{end}}:{{.Severity}}: {{.Message}} ({{.Linter}})"
+
+// Severity of linter message
+type Severity string
+
+// Linter message severity levels.
+const (
+	Error   Severity = "error"
+	Warning Severity = "warning"
+)
+
+type Issue struct {
+	Linter     string   `json:"linter"`
+	Severity   Severity `json:"severity"`
+	Path       string   `json:"path"`
+	Line       int      `json:"line"`
+	Col        int      `json:"col"`
+	Message    string   `json:"message"`
+	formatTmpl *template.Template
+}
+
+// NewIssue returns a new issue. Returns an error if formatTmpl is not a valid
+// template for an Issue.
+func NewIssue(linter string, formatTmpl *template.Template) (*Issue, error) {
+	issue := &Issue{
+		Line:       1,
+		Severity:   Warning,
+		Linter:     linter,
+		formatTmpl: formatTmpl,
+	}
+	err := formatTmpl.Execute(ioutil.Discard, issue)
+	return issue, err
+}
+
+func (i *Issue) String() string {
+	if i.formatTmpl == nil {
+		col := ""
+		if i.Col != 0 {
+			col = fmt.Sprintf("%d", i.Col)
+		}
+		return fmt.Sprintf("%s:%d:%s:%s: %s (%s)", strings.TrimSpace(i.Path), i.Line, col, i.Severity, strings.TrimSpace(i.Message), i.Linter)
+	}
+	buf := new(bytes.Buffer)
+	_ = i.formatTmpl.Execute(buf, i)
+	return buf.String()
+}
+
+type sortedIssues struct {
+	issues []*Issue
+	order  []string
+}
+
+func (s *sortedIssues) Len() int      { return len(s.issues) }
+func (s *sortedIssues) Swap(i, j int) { s.issues[i], s.issues[j] = s.issues[j], s.issues[i] }
+
+func (s *sortedIssues) Less(i, j int) bool {
+	l, r := s.issues[i], s.issues[j]
+	return CompareIssue(*l, *r, s.order)
+}
+
+// CompareIssue two Issues and return true if left should sort before right
+// nolint: gocyclo
+func CompareIssue(l, r Issue, order []string) bool {
+	for _, key := range order {
+		switch {
+		case key == "path" && l.Path != r.Path:
+			return l.Path < r.Path
+		case key == "line" && l.Line != r.Line:
+			return l.Line < r.Line
+		case key == "column" && l.Col != r.Col:
+			return l.Col < r.Col
+		case key == "severity" && l.Severity != r.Severity:
+			return l.Severity < r.Severity
+		case key == "message" && l.Message != r.Message:
+			return l.Message < r.Message
+		case key == "linter" && l.Linter != r.Linter:
+			return l.Linter < r.Linter
+		}
+	}
+	return true
+}
+
+// SortIssueChan reads issues from one channel, sorts them, and returns them to another
+// channel
+func SortIssueChan(issues chan *Issue, order []string) chan *Issue {
+	out := make(chan *Issue, 1000000)
+	sorted := &sortedIssues{
+		issues: []*Issue{},
+		order:  order,
+	}
+	go func() {
+		for issue := range issues {
+			sorted.issues = append(sorted.issues, issue)
+		}
+		sort.Sort(sorted)
+		for _, issue := range sorted.issues {
+			out <- issue
+		}
+		close(out)
+	}()
+	return out
+}

tools/vendor/github.com/alecthomas/gometalinter/linters.go

@@ -8,11 +8,10 @@ import (
 	"sort"
 	"strings"
 
-	"gopkg.in/alecthomas/kingpin.v3-unstable"
+	kingpin "gopkg.in/alecthomas/kingpin.v3-unstable"
 )
 
 type LinterConfig struct {
-	Name              string
 	Command           string
 	Pattern           string
 	InstallFrom       string
@@ -23,11 +22,12 @@ type LinterConfig struct {
 
 type Linter struct {
 	LinterConfig
+	Name  string
 	regex *regexp.Regexp
 }
 
 // NewLinter returns a new linter from a config
-func NewLinter(config LinterConfig) (*Linter, error) {
+func NewLinter(name string, config LinterConfig) (*Linter, error) {
 	if p, ok := predefinedPatterns[config.Pattern]; ok {
 		config.Pattern = p
 	}
@@ -35,8 +35,12 @@ func NewLinter(config LinterConfig) (*Linter, error) {
 	if err != nil {
 		return nil, err
 	}
+	if config.PartitionStrategy == nil {
+		config.PartitionStrategy = partitionPathsAsDirectories
+	}
 	return &Linter{
 		LinterConfig: config,
+		Name:         name,
 		regex:        regex,
 	}, nil
 }
@@ -50,26 +54,41 @@ var predefinedPatterns = map[string]string{
 	"PATH:LINE:MESSAGE":     `^(?P<path>.*?\.go):(?P<line>\d+):\s*(?P<message>.*)$`,
 }
 
-func getLinterByName(name string, customSpec string) *Linter {
-	if customSpec != "" {
-		return parseLinterSpec(name, customSpec)
+func getLinterByName(name string, overrideConf LinterConfig) *Linter {
+	conf := defaultLinters[name]
+	if val := overrideConf.Command; val != "" {
+		conf.Command = val
 	}
-	linter, _ := NewLinter(defaultLinters[name])
+	if val := overrideConf.Pattern; val != "" {
+		conf.Pattern = val
+	}
+	if val := overrideConf.InstallFrom; val != "" {
+		conf.InstallFrom = val
+	}
+	if overrideConf.IsFast {
+		conf.IsFast = true
+	}
+	if val := overrideConf.PartitionStrategy; val != nil {
+		conf.PartitionStrategy = val
+	}
+
+	linter, _ := NewLinter(name, conf)
 	return linter
 }
 
-func parseLinterSpec(name string, spec string) *Linter {
+func parseLinterConfigSpec(name string, spec string) (LinterConfig, error) {
 	parts := strings.SplitN(spec, ":", 2)
 	if len(parts) < 2 {
-		kingpin.Fatalf("invalid linter: %q", spec)
+		return LinterConfig{}, fmt.Errorf("linter spec needs at least two components")
 	}
 
 	config := defaultLinters[name]
 	config.Command, config.Pattern = parts[0], parts[1]
+	if predefined, ok := predefinedPatterns[config.Pattern]; ok {
+		config.Pattern = predefined
+	}
 
-	linter, err := NewLinter(config)
-	kingpin.FatalIfError(err, "invalid linter %q", name)
-	return linter
+	return config, nil
 }
 
 func makeInstallCommand(linters ...string) []string {
@@ -148,9 +167,9 @@ func installLinters() {
 
 func getDefaultLinters() []*Linter {
 	out := []*Linter{}
-	for _, config := range defaultLinters {
-		linter, err := NewLinter(config)
-		kingpin.FatalIfError(err, "invalid linter %q", config.Name)
+	for name, config := range defaultLinters {
+		linter, err := NewLinter(name, config)
+		kingpin.FatalIfError(err, "invalid linter %q", name)
 		out = append(out, linter)
 	}
 	return out
@@ -166,226 +185,228 @@ func defaultEnabled() []string {
 	return enabled
 }
 
+func validateLinters(linters map[string]*Linter, config *Config) error {
+	var unknownLinters []string
+	for name := range linters {
+		if _, isDefault := defaultLinters[name]; !isDefault {
+			if _, isCustom := config.Linters[name]; !isCustom {
+				unknownLinters = append(unknownLinters, name)
+			}
+		}
+	}
+	if len(unknownLinters) > 0 {
+		return fmt.Errorf("unknown linters: %s", strings.Join(unknownLinters, ", "))
+	}
+	return nil
+}
+
 const vetPattern = `^(?:vet:.*?\.go:\s+(?P<path>.*?\.go):(?P<line>\d+):(?P<col>\d+):\s*(?P<message>.*))|(?:(?P<path>.*?\.go):(?P<line>\d+):\s*(?P<message>.*))$`
 
 var defaultLinters = map[string]LinterConfig{
-	"aligncheck": {
-		Name:              "aligncheck",
-		Command:           "aligncheck",
+	"maligned": {
+		Command:           "maligned",
 		Pattern:           `^(?:[^:]+: )?(?P<path>.*?\.go):(?P<line>\d+):(?P<col>\d+):\s*(?P<message>.+)$`,
-		InstallFrom:       "github.com/opennota/check/cmd/aligncheck",
-		PartitionStrategy: partitionToMaxArgSizeWithPackagePaths,
+		InstallFrom:       "github.com/mdempsky/maligned",
+		PartitionStrategy: partitionPathsAsPackages,
 		defaultEnabled:    true,
 	},
 	"deadcode": {
-		Name:              "deadcode",
 		Command:           "deadcode",
 		Pattern:           `^deadcode: (?P<path>.*?\.go):(?P<line>\d+):(?P<col>\d+):\s*(?P<message>.*)$`,
 		InstallFrom:       "github.com/tsenart/deadcode",
-		PartitionStrategy: partitionToMaxArgSize,
+		PartitionStrategy: partitionPathsAsDirectories,
 		defaultEnabled:    true,
 	},
 	"dupl": {
-		Name:              "dupl",
 		Command:           `dupl -plumbing -threshold {duplthreshold}`,
 		Pattern:           `^(?P<path>.*?\.go):(?P<line>\d+)-\d+:\s*(?P<message>.*)$`,
 		InstallFrom:       "github.com/mibk/dupl",
-		PartitionStrategy: partitionToMaxArgSizeWithFileGlobs,
+		PartitionStrategy: partitionPathsAsFiles,
 		IsFast:            true,
 	},
 	"errcheck": {
-		Name:              "errcheck",
-		Command:           `errcheck -abspath`,
+		Command:           `errcheck -abspath {not_tests=-ignoretests}`,
 		Pattern:           `PATH:LINE:COL:MESSAGE`,
 		InstallFrom:       "github.com/kisielk/errcheck",
-		PartitionStrategy: partitionToMaxArgSizeWithPackagePaths,
+		PartitionStrategy: partitionPathsAsPackages,
 		defaultEnabled:    true,
 	},
 	"gas": {
-		Name:              "gas",
 		Command:           `gas -fmt=csv`,
 		Pattern:           `^(?P<path>.*?\.go),(?P<line>\d+),(?P<message>[^,]+,[^,]+,[^,]+)`,
 		InstallFrom:       "github.com/GoASTScanner/gas",
-		PartitionStrategy: partitionToMaxArgSize,
+		PartitionStrategy: partitionPathsAsFiles,
 		defaultEnabled:    true,
 		IsFast:            true,
 	},
 	"goconst": {
-		Name:              "goconst",
 		Command:           `goconst -min-occurrences {min_occurrences} -min-length {min_const_length}`,
 		Pattern:           `PATH:LINE:COL:MESSAGE`,
 		InstallFrom:       "github.com/jgautheron/goconst/cmd/goconst",
-		PartitionStrategy: partitionToMaxArgSize,
+		PartitionStrategy: partitionPathsAsDirectories,
 		defaultEnabled:    true,
 		IsFast:            true,
 	},
 	"gocyclo": {
-		Name:              "gocyclo",
 		Command:           `gocyclo -over {mincyclo}`,
 		Pattern:           `^(?P<cyclo>\d+)\s+\S+\s(?P<function>\S+)\s+(?P<path>.*?\.go):(?P<line>\d+):(\d+)$`,
 		InstallFrom:       "github.com/alecthomas/gocyclo",
-		PartitionStrategy: partitionToMaxArgSize,
+		PartitionStrategy: partitionPathsAsDirectories,
 		defaultEnabled:    true,
 		IsFast:            true,
 	},
 	"gofmt": {
-		Name:              "gofmt",
 		Command:           `gofmt -l -s`,
 		Pattern:           `^(?P<path>.*?\.go)$`,
-		PartitionStrategy: partitionToMaxArgSizeWithFileGlobs,
+		PartitionStrategy: partitionPathsAsFiles,
 		IsFast:            true,
 	},
 	"goimports": {
-		Name:              "goimports",
 		Command:           `goimports -l`,
 		Pattern:           `^(?P<path>.*?\.go)$`,
 		InstallFrom:       "golang.org/x/tools/cmd/goimports",
-		PartitionStrategy: partitionToMaxArgSizeWithFileGlobs,
+		PartitionStrategy: partitionPathsAsFiles,
 		IsFast:            true,
 	},
 	"golint": {
-		Name:              "golint",
 		Command:           `golint -min_confidence {min_confidence}`,
 		Pattern:           `PATH:LINE:COL:MESSAGE`,
 		InstallFrom:       "github.com/golang/lint/golint",
-		PartitionStrategy: partitionToMaxArgSize,
+		PartitionStrategy: partitionPathsAsDirectories,
 		defaultEnabled:    true,
 		IsFast:            true,
 	},
 	"gosimple": {
-		Name:              "gosimple",
 		Command:           `gosimple`,
 		Pattern:           `PATH:LINE:COL:MESSAGE`,
 		InstallFrom:       "honnef.co/go/tools/cmd/gosimple",
-		PartitionStrategy: partitionToMaxArgSizeWithPackagePaths,
+		PartitionStrategy: partitionPathsAsPackages,
 	},
 	"gotype": {
-		Name:              "gotype",
 		Command:           `gotype -e {tests=-t}`,
 		Pattern:           `PATH:LINE:COL:MESSAGE`,
 		InstallFrom:       "golang.org/x/tools/cmd/gotype",
-		PartitionStrategy: partitionToMaxArgSize,
+		PartitionStrategy: partitionPathsByDirectory,
+		defaultEnabled:    true,
+		IsFast:            true,
+	},
+	"gotypex": {
+		Command:           `gotype -e -x`,
+		Pattern:           `PATH:LINE:COL:MESSAGE`,
+		InstallFrom:       "golang.org/x/tools/cmd/gotype",
+		PartitionStrategy: partitionPathsByDirectory,
 		defaultEnabled:    true,
 		IsFast:            true,
 	},
 	"ineffassign": {
-		Name:              "ineffassign",
 		Command:           `ineffassign -n`,
 		Pattern:           `PATH:LINE:COL:MESSAGE`,
 		InstallFrom:       "github.com/gordonklaus/ineffassign",
-		PartitionStrategy: partitionToMaxArgSize,
+		PartitionStrategy: partitionPathsAsDirectories,
 		defaultEnabled:    true,
 		IsFast:            true,
 	},
 	"interfacer": {
-		Name:              "interfacer",
 		Command:           `interfacer`,
 		Pattern:           `PATH:LINE:COL:MESSAGE`,
-		InstallFrom:       "github.com/mvdan/interfacer/cmd/interfacer",
-		PartitionStrategy: partitionToMaxArgSizeWithPackagePaths,
+		InstallFrom:       "mvdan.cc/interfacer",
+		PartitionStrategy: partitionPathsAsPackages,
 		defaultEnabled:    true,
 	},
 	"lll": {
-		Name:              "lll",
 		Command:           `lll -g -l {maxlinelength}`,
 		Pattern:           `PATH:LINE:MESSAGE`,
 		InstallFrom:       "github.com/walle/lll/cmd/lll",
-		PartitionStrategy: partitionToMaxArgSizeWithFileGlobs,
+		PartitionStrategy: partitionPathsAsFiles,
 		IsFast:            true,
 	},
 	"megacheck": {
-		Name:              "megacheck",
 		Command:           `megacheck`,
 		Pattern:           `PATH:LINE:COL:MESSAGE`,
 		InstallFrom:       "honnef.co/go/tools/cmd/megacheck",
-		PartitionStrategy: partitionToMaxArgSizeWithPackagePaths,
+		PartitionStrategy: partitionPathsAsPackages,
 		defaultEnabled:    true,
 	},
 	"misspell": {
-		Name:              "misspell",
 		Command:           `misspell -j 1`,
 		Pattern:           `PATH:LINE:COL:MESSAGE`,
 		InstallFrom:       "github.com/client9/misspell/cmd/misspell",
-		PartitionStrategy: partitionToMaxArgSizeWithFileGlobs,
+		PartitionStrategy: partitionPathsAsFiles,
 		IsFast:            true,
 	},
+	"nakedret": {
+		Command:           `nakedret`,
+		Pattern:           `^(?P<path>.*?\.go):(?P<line>\d+)\s*(?P<message>.*)$`,
+		InstallFrom:       "github.com/alexkohler/nakedret",
+		PartitionStrategy: partitionPathsAsDirectories,
+	},
 	"safesql": {
-		Name:              "safesql",
 		Command:           `safesql`,
 		Pattern:           `^- (?P<path>.*?\.go):(?P<line>\d+):(?P<col>\d+)$`,
 		InstallFrom:       "github.com/stripe/safesql",
-		PartitionStrategy: partitionToMaxArgSizeWithPackagePaths,
+		PartitionStrategy: partitionPathsAsPackages,
 	},
 	"staticcheck": {
-		Name:              "staticcheck",
 		Command:           `staticcheck`,
 		Pattern:           `PATH:LINE:COL:MESSAGE`,
 		InstallFrom:       "honnef.co/go/tools/cmd/staticcheck",
-		PartitionStrategy: partitionToMaxArgSizeWithPackagePaths,
+		PartitionStrategy: partitionPathsAsPackages,
 	},
 	"structcheck": {
-		Name:              "structcheck",
 		Command:           `structcheck {tests=-t}`,
 		Pattern:           `^(?:[^:]+: )?(?P<path>.*?\.go):(?P<line>\d+):(?P<col>\d+):\s*(?P<message>.+)$`,
 		InstallFrom:       "github.com/opennota/check/cmd/structcheck",
-		PartitionStrategy: partitionToMaxArgSizeWithPackagePaths,
+		PartitionStrategy: partitionPathsAsPackages,
 		defaultEnabled:    true,
 	},
 	"test": {
-		Name:              "test",
 		Command:           `go test`,
 		Pattern:           `^--- FAIL: .*$\s+(?P<path>.*?\.go):(?P<line>\d+): (?P<message>.*)$`,
-		PartitionStrategy: partitionToMaxArgSizeWithPackagePaths,
+		PartitionStrategy: partitionPathsAsPackages,
 	},
 	"testify": {
-		Name:              "testify",
 		Command:           `go test`,
 		Pattern:           `Location:\s+(?P<path>.*?\.go):(?P<line>\d+)$\s+Error:\s+(?P<message>[^\n]+)`,
-		PartitionStrategy: partitionToMaxArgSizeWithPackagePaths,
+		PartitionStrategy: partitionPathsAsPackages,
 	},
 	"unconvert": {
-		Name:              "unconvert",
 		Command:           `unconvert`,
 		Pattern:           `PATH:LINE:COL:MESSAGE`,
 		InstallFrom:       "github.com/mdempsky/unconvert",
-		PartitionStrategy: partitionToMaxArgSizeWithPackagePaths,
+		PartitionStrategy: partitionPathsAsPackages,
 		defaultEnabled:    true,
 	},
 	"unparam": {
-		Name:              "unparam",
-		Command:           `unparam`,
+		Command:           `unparam {not_tests=-tests=false}`,
 		Pattern:           `PATH:LINE:COL:MESSAGE`,
-		InstallFrom:       "github.com/mvdan/unparam",
-		PartitionStrategy: partitionToMaxArgSizeWithPackagePaths,
+		InstallFrom:       "mvdan.cc/unparam",
+		PartitionStrategy: partitionPathsAsPackages,
 	},
 	"unused": {
-		Name:              "unused",
 		Command:           `unused`,
 		Pattern:           `PATH:LINE:COL:MESSAGE`,
 		InstallFrom:       "honnef.co/go/tools/cmd/unused",
-		PartitionStrategy: partitionToMaxArgSizeWithPackagePaths,
+		PartitionStrategy: partitionPathsAsPackages,
 	},
 	"varcheck": {
-		Name:              "varcheck",
 		Command:           `varcheck`,
 		Pattern:           `^(?:[^:]+: )?(?P<path>.*?\.go):(?P<line>\d+):(?P<col>\d+):\s*(?P<message>.*)$`,
 		InstallFrom:       "github.com/opennota/check/cmd/varcheck",
-		PartitionStrategy: partitionToMaxArgSizeWithPackagePaths,
+		PartitionStrategy: partitionPathsAsPackages,
 		defaultEnabled:    true,
 	},
 	"vet": {
-		Name:              "vet",
-		Command:           `go tool vet`,
+		Command:           `govet --no-recurse`,
 		Pattern:           vetPattern,
-		PartitionStrategy: partitionToPackageFileGlobs,
+		InstallFrom:       "github.com/dnephin/govet",
+		PartitionStrategy: partitionPathsAsDirectories,
 		defaultEnabled:    true,
 		IsFast:            true,
 	},
 	"vetshadow": {
-		Name:              "vetshadow",
-		Command:           `go tool vet --shadow`,
+		Command:           `govet --no-recurse --shadow`,
 		Pattern:           vetPattern,
-		PartitionStrategy: partitionToPackageFileGlobs,
+		PartitionStrategy: partitionPathsAsDirectories,
 		defaultEnabled:    true,
 		IsFast:            true,
 	},

tools/vendor/github.com/alecthomas/gometalinter/main.go

@@ -14,7 +14,7 @@ import (
 	"text/template"
 	"time"
 
-	"gopkg.in/alecthomas/kingpin.v3-unstable"
+	kingpin "gopkg.in/alecthomas/kingpin.v3-unstable"
 )
 
 var (
@@ -26,10 +26,10 @@ var (
 )
 
 func setupFlags(app *kingpin.Application) {
-	app.Flag("config", "Load JSON configuration from file.").Action(loadConfig).String()
+	app.Flag("config", "Load JSON configuration from file.").Envar("GOMETALINTER_CONFIG").Action(loadConfig).String()
 	app.Flag("disable", "Disable previously enabled linters.").PlaceHolder("LINTER").Short('D').Action(disableAction).Strings()
 	app.Flag("enable", "Enable previously disabled linters.").PlaceHolder("LINTER").Short('E').Action(enableAction).Strings()
-	app.Flag("linter", "Define a linter.").PlaceHolder("NAME:COMMAND:PATTERN").StringMapVar(&config.Linters)
+	app.Flag("linter", "Define a linter.").PlaceHolder("NAME:COMMAND:PATTERN").Action(cliLinterOverrides).StringMap()
 	app.Flag("message-overrides", "Override message from linter. {message} will be expanded to the original message.").PlaceHolder("LINTER:MESSAGE").StringMapVar(&config.MessageOverride)
 	app.Flag("severity", "Map of linter severities.").PlaceHolder("LINTER:SEVERITY").StringMapVar(&config.Severity)
 	app.Flag("disable-all", "Disable all linters.").Action(disableAllAction).Bool()
@@ -51,19 +51,36 @@ func setupFlags(app *kingpin.Application) {
 	app.Flag("line-length", "Report lines longer than N (using lll).").PlaceHolder("80").IntVar(&config.LineLength)
 	app.Flag("min-confidence", "Minimum confidence interval to pass to golint.").PlaceHolder(".80").FloatVar(&config.MinConfidence)
 	app.Flag("min-occurrences", "Minimum occurrences to pass to goconst.").PlaceHolder("3").IntVar(&config.MinOccurrences)
-	app.Flag("min-const-length", "Minimumum constant length.").PlaceHolder("3").IntVar(&config.MinConstLength)
+	app.Flag("min-const-length", "Minimum constant length.").PlaceHolder("3").IntVar(&config.MinConstLength)
 	app.Flag("dupl-threshold", "Minimum token sequence as a clone for dupl.").PlaceHolder("50").IntVar(&config.DuplThreshold)
 	app.Flag("sort", fmt.Sprintf("Sort output by any of %s.", strings.Join(sortKeys, ", "))).PlaceHolder("none").EnumsVar(&config.Sort, sortKeys...)
-	app.Flag("tests", "Include test files for linters that support this option").Short('t').BoolVar(&config.Test)
+	app.Flag("tests", "Include test files for linters that support this option.").Short('t').BoolVar(&config.Test)
 	app.Flag("deadline", "Cancel linters if they have not completed within this duration.").PlaceHolder("30s").DurationVar((*time.Duration)(&config.Deadline))
 	app.Flag("errors", "Only show errors.").BoolVar(&config.Errors)
 	app.Flag("json", "Generate structured JSON rather than standard line-based output.").BoolVar(&config.JSON)
 	app.Flag("checkstyle", "Generate checkstyle XML rather than standard line-based output.").BoolVar(&config.Checkstyle)
 	app.Flag("enable-gc", "Enable GC for linters (useful on large repositories).").BoolVar(&config.EnableGC)
 	app.Flag("aggregate", "Aggregate issues reported by several linters.").BoolVar(&config.Aggregate)
+	app.Flag("warn-unmatched-nolint", "Warn if a nolint directive is not matched with an issue.").BoolVar(&config.WarnUnmatchedDirective)
 	app.GetFlag("help").Short('h')
 }
 
+func cliLinterOverrides(app *kingpin.Application, element *kingpin.ParseElement, ctx *kingpin.ParseContext) error {
+	// expected input structure - <name>:<command-spec>
+	parts := strings.SplitN(*element.Value, ":", 2)
+	if len(parts) < 2 {
+		return fmt.Errorf("incorrectly formatted input: %s", *element.Value)
+	}
+	name := parts[0]
+	spec := parts[1]
+	conf, err := parseLinterConfigSpec(name, spec)
+	if err != nil {
+		return fmt.Errorf("incorrectly formatted input: %s", *element.Value)
+	}
+	config.Linters[name] = StringOrLinterConfig(conf)
+	return nil
+}
+
 func loadConfig(app *kingpin.Application, element *kingpin.ParseElement, ctx *kingpin.ParseContext) error {
 	r, err := os.Open(*element.Value)
 	if err != nil {
@@ -114,12 +131,20 @@ func enableAllAction(app *kingpin.Application, element *kingpin.ParseElement, ct
 	return nil
 }
 
+type debugFunction func(format string, args ...interface{})
+
 func debug(format string, args ...interface{}) {
 	if config.Debug {
 		fmt.Fprintf(os.Stderr, "DEBUG: "+format+"\n", args...)
 	}
 }
 
+func namespacedDebug(prefix string) debugFunction {
+	return func(format string, args ...interface{}) {
+		debug(prefix+format, args...)
+	}
+}
+
 func warning(format string, args ...interface{}) {
 	fmt.Fprintf(os.Stderr, "WARNING: "+format+"\n", args...)
 }
@@ -131,8 +156,8 @@ func formatLinters() string {
 		if install == "()" {
 			install = ""
 		}
-		fmt.Fprintf(w, "  %s  %s\n        %s\n        %s\n",
-			linter.Name, install, linter.Command, linter.Pattern)
+		fmt.Fprintf(w, "  %s: %s\n\tcommand: %s\n\tregex: %s\n\tfast: %t\n\tdefault enabled: %t\n\n",
+			linter.Name, install, linter.Command, linter.Pattern, linter.IsFast, linter.defaultEnabled)
 	}
 	return w.String()
 }
@@ -176,6 +201,9 @@ Severity override map (default is "warning"):
 	paths := resolvePaths(*pathsArg, config.Skip)
 
 	linters := lintersFromConfig(config)
+	err := validateLinters(linters, config)
+	kingpin.FatalIfError(err, "")
+
 	issues, errch := runLinters(linters, paths, config.Concurrency, exclude, include)
 	status := 0
 	if config.JSON {
@@ -198,7 +226,7 @@ Severity override map (default is "warning"):
 func processConfig(config *Config) (include *regexp.Regexp, exclude *regexp.Regexp) {
 	tmpl, err := template.New("output").Parse(config.Format)
 	kingpin.FatalIfError(err, "invalid format %q", config.Format)
-	formatTemplate = tmpl
+	config.formatTemplate = tmpl
 
 	// Linters are by their very nature, short lived, so disable GC.
 	// Reduced (user) linting time on kingpin from 0.97s to 0.64s.
@@ -340,8 +368,7 @@ func lintersFromConfig(config *Config) map[string]*Linter {
 	out := map[string]*Linter{}
 	config.Enable = replaceWithMegacheck(config.Enable, config.EnableAll)
 	for _, name := range config.Enable {
-		linter := getLinterByName(name, config.Linters[name])
-
+		linter := getLinterByName(name, LinterConfig(config.Linters[name]))
 		if config.Fast && !linter.IsFast {
 			continue
 		}

tools/vendor/github.com/alecthomas/gometalinter/partition.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"encoding/json"
 	"fmt"
 	"path/filepath"
 )
@@ -10,6 +11,29 @@ const MaxCommandBytes = 32000
 
 type partitionStrategy func([]string, []string) ([][]string, error)
 
+func (ps *partitionStrategy) UnmarshalJSON(raw []byte) error {
+	var strategyName string
+	if err := json.Unmarshal(raw, &strategyName); err != nil {
+		return err
+	}
+
+	switch strategyName {
+	case "directories":
+		*ps = partitionPathsAsDirectories
+	case "files":
+		*ps = partitionPathsAsFiles
+	case "packages":
+		*ps = partitionPathsAsPackages
+	case "files-by-package":
+		*ps = partitionPathsAsFilesGroupedByPackage
+	case "single-directory":
+		*ps = partitionPathsByDirectory
+	default:
+		return fmt.Errorf("unknown parition strategy %s", strategyName)
+	}
+	return nil
+}
+
 func pathsToFileGlobs(paths []string) ([]string, error) {
 	filePaths := []string{}
 	for _, dir := range paths {
@@ -22,7 +46,7 @@ func pathsToFileGlobs(paths []string) ([]string, error) {
 	return filePaths, nil
 }
 
-func partitionToMaxArgSize(cmdArgs []string, paths []string) ([][]string, error) {
+func partitionPathsAsDirectories(cmdArgs []string, paths []string) ([][]string, error) {
 	return partitionToMaxSize(cmdArgs, paths, MaxCommandBytes), nil
 }
 
@@ -72,15 +96,15 @@ func (p *sizePartitioner) end() [][]string {
 	return p.parts
 }
 
-func partitionToMaxArgSizeWithFileGlobs(cmdArgs []string, paths []string) ([][]string, error) {
+func partitionPathsAsFiles(cmdArgs []string, paths []string) ([][]string, error) {
 	filePaths, err := pathsToFileGlobs(paths)
 	if err != nil || len(filePaths) == 0 {
 		return nil, err
 	}
-	return partitionToMaxArgSize(cmdArgs, filePaths)
+	return partitionPathsAsDirectories(cmdArgs, filePaths)
 }
 
-func partitionToPackageFileGlobs(cmdArgs []string, paths []string) ([][]string, error) {
+func partitionPathsAsFilesGroupedByPackage(cmdArgs []string, paths []string) ([][]string, error) {
 	parts := [][]string{}
 	for _, path := range paths {
 		filePaths, err := pathsToFileGlobs([]string{path})
@@ -95,12 +119,12 @@ func partitionToPackageFileGlobs(cmdArgs []string, paths []string) ([][]string,
 	return parts, nil
 }
 
-func partitionToMaxArgSizeWithPackagePaths(cmdArgs []string, paths []string) ([][]string, error) {
+func partitionPathsAsPackages(cmdArgs []string, paths []string) ([][]string, error) {
 	packagePaths, err := pathsToPackagePaths(paths)
 	if err != nil || len(packagePaths) == 0 {
 		return nil, err
 	}
-	return partitionToMaxArgSize(cmdArgs, packagePaths)
+	return partitionPathsAsDirectories(cmdArgs, packagePaths)
 }
 
 func pathsToPackagePaths(paths []string) ([]string, error) {
@@ -129,3 +153,11 @@ func packageNameFromPath(path string) (string, error) {
 	}
 	return "", fmt.Errorf("%s not in GOPATH", path)
 }
+
+func partitionPathsByDirectory(cmdArgs []string, paths []string) ([][]string, error) {
+	parts := [][]string{}
+	for _, path := range paths {
+		parts = append(parts, append(cmdArgs, path))
+	}
+	return parts, nil
+}

tools/vendor/github.com/alexkohler/nakedret/LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2017 Alex Kohler
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

tools/vendor/github.com/alexkohler/nakedret/README.md

@@ -0,0 +1,103 @@
+# nakedret
+
+nakedret is a Go static analysis tool to find naked returns in functions greater than a specified function length.
+
+## Installation
+
+    go get -u github.com/alexkohler/nakedret
+
+## Usage
+
+Similar to other Go static anaylsis tools (such as golint, go vet) , nakedret can be invoked with one or more filenames, directories, or packages named by its import path. Nakedret also supports the `...` wildcard. 
+
+    nakedret [flags] files/directories/packages
+
+Currently, the only flag supported is -l, which is an optional numeric flag to specify the maximum length a function can be (in terms of line length). If not specified, it defaults to 5.
+
+## Purpose
+
+As noted in Go's [Code Review comments](https://github.com/golang/go/wiki/CodeReviewComments#named-result-parameters):
+
+> Naked returns are okay if the function is a handful of lines. Once it's a medium sized function, be explicit with your return 
+> values. Corollary: it's not worth it to name result parameters just because it enables you to use naked returns. Clarity of docs is always more important than saving a line or two in your function.
+
+This tool aims to catch naked returns on non-trivial functions.
+
+## Example
+
+Let's take the `types` package in the Go source as an example:
+
+```Bash
+$ nakedret -l 25 types/
+types/check.go:245 checkFiles naked returns on 26 line function 
+types/typexpr.go:443 collectParams naked returns on 53 line function 
+types/stmt.go:275 caseTypes naked returns on 27 line function 
+types/lookup.go:275 MissingMethod naked returns on 39 line function
+```
+
+Below is one of the not so intuitive uses of naked returns in `types/lookup.go` found by nakedret (nakedret will return the line number of the last naked return in the function):
+
+
+```Go
+func MissingMethod(V Type, T *Interface, static bool) (method *Func, wrongType bool) {
+	// fast path for common case
+	if T.Empty() {
+		return
+	}
+
+	// TODO(gri) Consider using method sets here. Might be more efficient.
+
+	if ityp, _ := V.Underlying().(*Interface); ityp != nil {
+		// TODO(gri) allMethods is sorted - can do this more efficiently
+		for _, m := range T.allMethods {
+			_, obj := lookupMethod(ityp.allMethods, m.pkg, m.name)
+			switch {
+			case obj == nil:
+				if static {
+					return m, false
+				}
+			case !Identical(obj.Type(), m.typ):
+				return m, true
+			}
+		}
+		return
+	}
+
+	// A concrete type implements T if it implements all methods of T.
+	for _, m := range T.allMethods {
+		obj, _, _ := lookupFieldOrMethod(V, false, m.pkg, m.name)
+
+		f, _ := obj.(*Func)
+		if f == nil {
+			return m, false
+		}
+
+		if !Identical(f.typ, m.typ) {
+			return m, true
+		}
+	}
+
+	return
+}
+```
+
+## TODO
+
+- Unit tests (may require some refactoring to do correctly)
+- supporting toggling of `build.Context.UseAllFiles` may be useful for some. 
+- Configuration on whether or not to run on test files
+- Vim quickfix format?
+- Globbing support (e.g. nakedret *.go)
+
+
+## Contributing
+
+Pull requests welcome!
+
+
+## Other static analysis tools
+
+If you've enjoyed nakedret, take a look at my other static anaylsis tools!
+
+- [unimport](https://github.com/alexkohler/unimport) - Finds unnecessary import aliases
+- [prealloc](https://github.com/alexkohler/prealloc) - Finds slice declarations that could potentially be preallocated.

tools/vendor/github.com/alexkohler/nakedret/import.go

@@ -0,0 +1,310 @@
+package main
+
+/*
+
+This file holds a direct copy of the import path matching code of
+https://github.com/golang/go/blob/master/src/cmd/go/main.go. It can be
+replaced when https://golang.org/issue/8768 is resolved.
+
+It has been updated to follow upstream changes in a few ways.
+
+*/
+
+import (
+	"fmt"
+	"go/build"
+	"log"
+	"os"
+	"path"
+	"path/filepath"
+	"regexp"
+	"runtime"
+	"strings"
+)
+
+var buildContext = build.Default
+
+var (
+	goroot    = filepath.Clean(runtime.GOROOT())
+	gorootSrc = filepath.Join(goroot, "src")
+)
+
+// importPathsNoDotExpansion returns the import paths to use for the given
+// command line, but it does no ... expansion.
+func importPathsNoDotExpansion(args []string) []string {
+	if len(args) == 0 {
+		return []string{"."}
+	}
+	var out []string
+	for _, a := range args {
+		// Arguments are supposed to be import paths, but
+		// as a courtesy to Windows developers, rewrite \ to /
+		// in command-line arguments.  Handles .\... and so on.
+		if filepath.Separator == '\\' {
+			a = strings.Replace(a, `\`, `/`, -1)
+		}
+
+		// Put argument in canonical form, but preserve leading ./.
+		if strings.HasPrefix(a, "./") {
+			a = "./" + path.Clean(a)
+			if a == "./." {
+				a = "."
+			}
+		} else {
+			a = path.Clean(a)
+		}
+		if a == "all" || a == "std" {
+			out = append(out, allPackages(a)...)
+			continue
+		}
+		out = append(out, a)
+	}
+	return out
+}
+
+// importPaths returns the import paths to use for the given command line.
+func importPaths(args []string) []string {
+	args = importPathsNoDotExpansion(args)
+	var out []string
+	for _, a := range args {
+		if strings.Contains(a, "...") {
+			if build.IsLocalImport(a) {
+				out = append(out, allPackagesInFS(a)...)
+			} else {
+				out = append(out, allPackages(a)...)
+			}
+			continue
+		}
+		out = append(out, a)
+	}
+	return out
+}
+
+// matchPattern(pattern)(name) reports whether
+// name matches pattern.  Pattern is a limited glob
+// pattern in which '...' means 'any string' and there
+// is no other special syntax.
+func matchPattern(pattern string) func(name string) bool {
+	re := regexp.QuoteMeta(pattern)
+	re = strings.Replace(re, `\.\.\.`, `.*`, -1)
+	// Special case: foo/... matches foo too.
+	if strings.HasSuffix(re, `/.*`) {
+		re = re[:len(re)-len(`/.*`)] + `(/.*)?`
+	}
+	reg := regexp.MustCompile(`^` + re + `$`)
+	return func(name string) bool {
+		return reg.MatchString(name)
+	}
+}
+
+// hasPathPrefix reports whether the path s begins with the
+// elements in prefix.
+func hasPathPrefix(s, prefix string) bool {
+	switch {
+	default:
+		return false
+	case len(s) == len(prefix):
+		return s == prefix
+	case len(s) > len(prefix):
+		if prefix != "" && prefix[len(prefix)-1] == '/' {
+			return strings.HasPrefix(s, prefix)
+		}
+		return s[len(prefix)] == '/' && s[:len(prefix)] == prefix
+	}
+}
+
+// treeCanMatchPattern(pattern)(name) reports whether
+// name or children of name can possibly match pattern.
+// Pattern is the same limited glob accepted by matchPattern.
+func treeCanMatchPattern(pattern string) func(name string) bool {
+	wildCard := false
+	if i := strings.Index(pattern, "..."); i >= 0 {
+		wildCard = true
+		pattern = pattern[:i]
+	}
+	return func(name string) bool {
+		return len(name) <= len(pattern) && hasPathPrefix(pattern, name) ||
+			wildCard && strings.HasPrefix(name, pattern)
+	}
+}
+
+// allPackages returns all the packages that can be found
+// under the $GOPATH directories and $GOROOT matching pattern.
+// The pattern is either "all" (all packages), "std" (standard packages)
+// or a path including "...".
+func allPackages(pattern string) []string {
+	pkgs := matchPackages(pattern)
+	if len(pkgs) == 0 {
+		fmt.Fprintf(os.Stderr, "warning: %q matched no packages\n", pattern)
+	}
+	return pkgs
+}
+
+func matchPackages(pattern string) []string {
+	match := func(string) bool { return true }
+	treeCanMatch := func(string) bool { return true }
+	if pattern != "all" && pattern != "std" {
+		match = matchPattern(pattern)
+		treeCanMatch = treeCanMatchPattern(pattern)
+	}
+
+	have := map[string]bool{
+		"builtin": true, // ignore pseudo-package that exists only for documentation
+	}
+	if !buildContext.CgoEnabled {
+		have["runtime/cgo"] = true // ignore during walk
+	}
+	var pkgs []string
+
+	// Commands
+	cmd := filepath.Join(goroot, "src/cmd") + string(filepath.Separator)
+	filepath.Walk(cmd, func(path string, fi os.FileInfo, err error) error {
+		if err != nil || !fi.IsDir() || path == cmd {
+			return nil
+		}
+		name := path[len(cmd):]
+		if !treeCanMatch(name) {
+			return filepath.SkipDir
+		}
+		// Commands are all in cmd/, not in subdirectories.
+		if strings.Contains(name, string(filepath.Separator)) {
+			return filepath.SkipDir
+		}
+
+		// We use, e.g., cmd/gofmt as the pseudo import path for gofmt.
+		name = "cmd/" + name
+		if have[name] {
+			return nil
+		}
+		have[name] = true
+		if !match(name) {
+			return nil
+		}
+		_, err = buildContext.ImportDir(path, 0)
+		if err != nil {
+			if _, noGo := err.(*build.NoGoError); !noGo {
+				log.Print(err)
+			}
+			return nil
+		}
+		pkgs = append(pkgs, name)
+		return nil
+	})
+
+	for _, src := range buildContext.SrcDirs() {
+		if (pattern == "std" || pattern == "cmd") && src != gorootSrc {
+			continue
+		}
+		src = filepath.Clean(src) + string(filepath.Separator)
+		root := src
+		if pattern == "cmd" {
+			root += "cmd" + string(filepath.Separator)
+		}
+		filepath.Walk(root, func(path string, fi os.FileInfo, err error) error {
+			if err != nil || !fi.IsDir() || path == src {
+				return nil
+			}
+
+			// Avoid .foo, _foo, testdata and vendor directory trees.
+			_, elem := filepath.Split(path)
+			if strings.HasPrefix(elem, ".") || strings.HasPrefix(elem, "_") || elem == "testdata" || elem == "vendor" {
+				return filepath.SkipDir
+			}
+
+			name := filepath.ToSlash(path[len(src):])
+			if pattern == "std" && (strings.Contains(name, ".") || name == "cmd") {
+				// The name "std" is only the standard library.
+				// If the name is cmd, it's the root of the command tree.
+				return filepath.SkipDir
+			}
+			if !treeCanMatch(name) {
+				return filepath.SkipDir
+			}
+			if have[name] {
+				return nil
+			}
+			have[name] = true
+			if !match(name) {
+				return nil
+			}
+			_, err = buildContext.ImportDir(path, 0)
+			if err != nil {
+				if _, noGo := err.(*build.NoGoError); noGo {
+					return nil
+				}
+			}
+			pkgs = append(pkgs, name)
+			return nil
+		})
+	}
+	return pkgs
+}
+
+// allPackagesInFS is like allPackages but is passed a pattern
+// beginning ./ or ../, meaning it should scan the tree rooted
+// at the given directory.  There are ... in the pattern too.
+func allPackagesInFS(pattern string) []string {
+	pkgs := matchPackagesInFS(pattern)
+	if len(pkgs) == 0 {
+		fmt.Fprintf(os.Stderr, "warning: %q matched no packages\n", pattern)
+	}
+	return pkgs
+}
+
+func matchPackagesInFS(pattern string) []string {
+	// Find directory to begin the scan.
+	// Could be smarter but this one optimization
+	// is enough for now, since ... is usually at the
+	// end of a path.
+	i := strings.Index(pattern, "...")
+	dir, _ := path.Split(pattern[:i])
+
+	// pattern begins with ./ or ../.
+	// path.Clean will discard the ./ but not the ../.
+	// We need to preserve the ./ for pattern matching
+	// and in the returned import paths.
+	prefix := ""
+	if strings.HasPrefix(pattern, "./") {
+		prefix = "./"
+	}
+	match := matchPattern(pattern)
+
+	var pkgs []string
+	filepath.Walk(dir, func(path string, fi os.FileInfo, err error) error {
+		if err != nil || !fi.IsDir() {
+			return nil
+		}
+		if path == dir {
+			// filepath.Walk starts at dir and recurses. For the recursive case,
+			// the path is the result of filepath.Join, which calls filepath.Clean.
+			// The initial case is not Cleaned, though, so we do this explicitly.
+			//
+			// This converts a path like "./io/" to "io". Without this step, running
+			// "cd $GOROOT/src/pkg; go list ./io/..." would incorrectly skip the io
+			// package, because prepending the prefix "./" to the unclean path would
+			// result in "././io", and match("././io") returns false.
+			path = filepath.Clean(path)
+		}
+
+		// Avoid .foo, _foo, testdata and vendor directory trees, but do not avoid "." or "..".
+		_, elem := filepath.Split(path)
+		dot := strings.HasPrefix(elem, ".") && elem != "." && elem != ".."
+		if dot || strings.HasPrefix(elem, "_") || elem == "testdata" || elem == "vendor" {
+			return filepath.SkipDir
+		}
+
+		name := prefix + filepath.ToSlash(path)
+		if !match(name) {
+			return nil
+		}
+		if _, err = build.ImportDir(path, 0); err != nil {
+			if _, noGo := err.(*build.NoGoError); !noGo {
+				log.Print(err)
+			}
+			return nil
+		}
+		pkgs = append(pkgs, name)
+		return nil
+	})
+	return pkgs
+}

tools/vendor/github.com/alexkohler/nakedret/nakedret.go

@@ -0,0 +1,213 @@
+package main
+
+import (
+	"errors"
+	"flag"
+	"fmt"
+	"go/ast"
+	"go/build"
+	"go/parser"
+	"go/token"
+	"log"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+const (
+	pwd = "./"
+)
+
+func init() {
+	//TODO allow build tags
+	build.Default.UseAllFiles = true
+}
+
+func usage() {
+	log.Printf("Usage of %s:\n", os.Args[0])
+	log.Printf("\nnakedret [flags] # runs on package in current directory\n")
+	log.Printf("\nnakedret [flags] [packages]\n")
+	log.Printf("Flags:\n")
+	flag.PrintDefaults()
+}
+
+type returnsVisitor struct {
+	f         *token.FileSet
+	maxLength uint
+}
+
+func main() {
+
+	// Remove log timestamp
+	log.SetFlags(0)
+
+	maxLength := flag.Uint("l", 5, "maximum number of lines for a naked return function")
+	flag.Usage = usage
+	flag.Parse()
+
+	if err := checkNakedReturns(flag.Args(), maxLength); err != nil {
+		log.Println(err)
+	}
+}
+
+func checkNakedReturns(args []string, maxLength *uint) error {
+
+	fset := token.NewFileSet()
+
+	files, err := parseInput(args, fset)
+	if err != nil {
+		return fmt.Errorf("could not parse input %v", err)
+	}
+
+	if maxLength == nil {
+		return errors.New("max length nil")
+	}
+
+	retVis := &returnsVisitor{
+		f:         fset,
+		maxLength: *maxLength,
+	}
+
+	for _, f := range files {
+		ast.Walk(retVis, f)
+	}
+
+	return nil
+}
+
+func parseInput(args []string, fset *token.FileSet) ([]*ast.File, error) {
+	var directoryList []string
+	var fileMode bool
+	files := make([]*ast.File, 0)
+
+	if len(args) == 0 {
+		directoryList = append(directoryList, pwd)
+	} else {
+		for _, arg := range args {
+			if strings.HasSuffix(arg, "/...") && isDir(arg[:len(arg)-len("/...")]) {
+
+				for _, dirname := range allPackagesInFS(arg) {
+					directoryList = append(directoryList, dirname)
+				}
+
+			} else if isDir(arg) {
+				directoryList = append(directoryList, arg)
+
+			} else if exists(arg) {
+				if strings.HasSuffix(arg, ".go") {
+					fileMode = true
+					f, err := parser.ParseFile(fset, arg, nil, 0)
+					if err != nil {
+						return nil, err
+					}
+					files = append(files, f)
+				} else {
+					return nil, fmt.Errorf("invalid file %v specified", arg)
+				}
+			} else {
+
+				//TODO clean this up a bit
+				imPaths := importPaths([]string{arg})
+				for _, importPath := range imPaths {
+					pkg, err := build.Import(importPath, ".", 0)
+					if err != nil {
+						return nil, err
+					}
+					var stringFiles []string
+					stringFiles = append(stringFiles, pkg.GoFiles...)
+					// files = append(files, pkg.CgoFiles...)
+					stringFiles = append(stringFiles, pkg.TestGoFiles...)
+					if pkg.Dir != "." {
+						for i, f := range stringFiles {
+							stringFiles[i] = filepath.Join(pkg.Dir, f)
+						}
+					}
+
+					fileMode = true
+					for _, stringFile := range stringFiles {
+						f, err := parser.ParseFile(fset, stringFile, nil, 0)
+						if err != nil {
+							return nil, err
+						}
+						files = append(files, f)
+					}
+
+				}
+			}
+		}
+	}
+
+	// if we're not in file mode, then we need to grab each and every package in each directory
+	// we can to grab all the files
+	if !fileMode {
+		for _, fpath := range directoryList {
+			pkgs, err := parser.ParseDir(fset, fpath, nil, 0)
+			if err != nil {
+				return nil, err
+			}
+
+			for _, pkg := range pkgs {
+				for _, f := range pkg.Files {
+					files = append(files, f)
+				}
+			}
+		}
+	}
+
+	return files, nil
+}
+
+func isDir(filename string) bool {
+	fi, err := os.Stat(filename)
+	return err == nil && fi.IsDir()
+}
+
+func exists(filename string) bool {
+	_, err := os.Stat(filename)
+	return err == nil
+}
+
+func (v *returnsVisitor) Visit(node ast.Node) ast.Visitor {
+	var namedReturns []*ast.Ident
+
+	funcDecl, ok := node.(*ast.FuncDecl)
+	if !ok {
+		return v
+	}
+	var functionLineLength int
+	// We've found a function
+	if funcDecl.Type != nil && funcDecl.Type.Results != nil {
+		for _, field := range funcDecl.Type.Results.List {
+			for _, ident := range field.Names {
+				if ident != nil {
+					namedReturns = append(namedReturns, ident)
+				}
+			}
+		}
+		file := v.f.File(funcDecl.Pos())
+		functionLineLength = file.Position(funcDecl.End()).Line - file.Position(funcDecl.Pos()).Line
+	}
+
+	if len(namedReturns) > 0 && funcDecl.Body != nil {
+		// Scan the body for usage of the named returns
+		for _, stmt := range funcDecl.Body.List {
+
+			switch s := stmt.(type) {
+			case *ast.ReturnStmt:
+				if len(s.Results) == 0 {
+					file := v.f.File(s.Pos())
+					if file != nil && uint(functionLineLength) > v.maxLength {
+						if funcDecl.Name != nil {
+							log.Printf("%v:%v %v naked returns on %v line function \n", file.Name(), file.Position(s.Pos()).Line, funcDecl.Name.Name, functionLineLength)
+						}
+					}
+					continue
+				}
+
+			default:
+			}
+		}
+	}
+
+	return v
+}

tools/vendor/github.com/client9/misspell/cmd/misspell/main.go

@@ -1,3 +1,4 @@
+// The misspell command corrects commonly misspelled English words in source files.
 package main
 
 import (

tools/vendor/github.com/dnephin/govet/LICENSE

@@ -0,0 +1,27 @@
+Copyright (c) 2009 The Go Authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+   * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

tools/vendor/github.com/dnephin/govet/README

@@ -0,0 +1,33 @@
+Vet is a tool that checks correctness of Go programs. It runs a suite of tests,
+each tailored to check for a particular class of errors. Examples include incorrect
+Printf format verbs or malformed build tags.
+
+Over time many checks have been added to vet's suite, but many more have been
+rejected as not appropriate for the tool. The criteria applied when selecting which
+checks to add are:
+
+Correctness:
+
+Vet's tools are about correctness, not style. A vet check must identify real or
+potential bugs that could cause incorrect compilation or execution. A check that
+only identifies stylistic points or alternative correct approaches to a situation
+is not acceptable.
+
+Frequency:
+
+Vet is run every day by many programmers, often as part of every compilation or
+submission. The cost in execution time is considerable, especially in aggregate,
+so checks must be likely enough to find real problems that they are worth the
+overhead of the added check. A new check that finds only a handful of problems
+across all existing programs, even if the problem is significant, is not worth
+adding to the suite everyone runs daily.
+
+Precision:
+
+Most of vet's checks are heuristic and can generate both false positives (flagging
+correct programs) and false negatives (not flagging incorrect ones). The rate of
+both these failures must be very small. A check that is too noisy will be ignored
+by the programmer overwhelmed by the output; a check that misses too many of the
+cases it's looking for will give a false sense of security. Neither is acceptable.
+A vet check must be accurate enough that everything it reports is worth examining,
+and complete enough to encourage real confidence.

tools/vendor/github.com/dnephin/govet/asmdecl.go

@@ -0,0 +1,682 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Identify mismatches between assembly files and Go func declarations.
+
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"go/ast"
+	"go/token"
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+// 'kind' is a kind of assembly variable.
+// The kinds 1, 2, 4, 8 stand for values of that size.
+type asmKind int
+
+// These special kinds are not valid sizes.
+const (
+	asmString asmKind = 100 + iota
+	asmSlice
+	asmInterface
+	asmEmptyInterface
+)
+
+// An asmArch describes assembly parameters for an architecture
+type asmArch struct {
+	name      string
+	ptrSize   int
+	intSize   int
+	maxAlign  int
+	bigEndian bool
+	stack     string
+	lr        bool
+}
+
+// An asmFunc describes the expected variables for a function on a given architecture.
+type asmFunc struct {
+	arch        *asmArch
+	size        int // size of all arguments
+	vars        map[string]*asmVar
+	varByOffset map[int]*asmVar
+}
+
+// An asmVar describes a single assembly variable.
+type asmVar struct {
+	name  string
+	kind  asmKind
+	typ   string
+	off   int
+	size  int
+	inner []*asmVar
+}
+
+var (
+	asmArch386      = asmArch{"386", 4, 4, 4, false, "SP", false}
+	asmArchArm      = asmArch{"arm", 4, 4, 4, false, "R13", true}
+	asmArchArm64    = asmArch{"arm64", 8, 8, 8, false, "RSP", true}
+	asmArchAmd64    = asmArch{"amd64", 8, 8, 8, false, "SP", false}
+	asmArchAmd64p32 = asmArch{"amd64p32", 4, 4, 8, false, "SP", false}
+	asmArchMips64   = asmArch{"mips64", 8, 8, 8, true, "R29", true}
+	asmArchMips64LE = asmArch{"mips64", 8, 8, 8, false, "R29", true}
+	asmArchPpc64    = asmArch{"ppc64", 8, 8, 8, true, "R1", true}
+	asmArchPpc64LE  = asmArch{"ppc64le", 8, 8, 8, false, "R1", true}
+
+	arches = []*asmArch{
+		&asmArch386,
+		&asmArchArm,
+		&asmArchArm64,
+		&asmArchAmd64,
+		&asmArchAmd64p32,
+		&asmArchMips64,
+		&asmArchMips64LE,
+		&asmArchPpc64,
+		&asmArchPpc64LE,
+	}
+)
+
+var (
+	re           = regexp.MustCompile
+	asmPlusBuild = re(`//\s+\+build\s+([^\n]+)`)
+	asmTEXT      = re(`\bTEXT\b.*·([^\(]+)\(SB\)(?:\s*,\s*([0-9A-Z|+]+))?(?:\s*,\s*\$(-?[0-9]+)(?:-([0-9]+))?)?`)
+	asmDATA      = re(`\b(DATA|GLOBL)\b`)
+	asmNamedFP   = re(`([a-zA-Z0-9_\xFF-\x{10FFFF}]+)(?:\+([0-9]+))\(FP\)`)
+	asmUnnamedFP = re(`[^+\-0-9](([0-9]+)\(FP\))`)
+	asmSP        = re(`[^+\-0-9](([0-9]+)\(([A-Z0-9]+)\))`)
+	asmOpcode    = re(`^\s*(?:[A-Z0-9a-z_]+:)?\s*([A-Z]+)\s*([^,]*)(?:,\s*(.*))?`)
+	ppc64Suff    = re(`([BHWD])(ZU|Z|U|BR)?$`)
+)
+
+func asmCheck(pkg *Package) {
+	if !vet("asmdecl") {
+		return
+	}
+
+	// No work if no assembly files.
+	if !pkg.hasFileWithSuffix(".s") {
+		return
+	}
+
+	// Gather declarations. knownFunc[name][arch] is func description.
+	knownFunc := make(map[string]map[string]*asmFunc)
+
+	for _, f := range pkg.files {
+		if f.file != nil {
+			for _, decl := range f.file.Decls {
+				if decl, ok := decl.(*ast.FuncDecl); ok && decl.Body == nil {
+					knownFunc[decl.Name.Name] = f.asmParseDecl(decl)
+				}
+			}
+		}
+	}
+
+Files:
+	for _, f := range pkg.files {
+		if !strings.HasSuffix(f.name, ".s") {
+			continue
+		}
+		Println("Checking file", f.name)
+
+		// Determine architecture from file name if possible.
+		var arch string
+		var archDef *asmArch
+		for _, a := range arches {
+			if strings.HasSuffix(f.name, "_"+a.name+".s") {
+				arch = a.name
+				archDef = a
+				break
+			}
+		}
+
+		lines := strings.SplitAfter(string(f.content), "\n")
+		var (
+			fn                 *asmFunc
+			fnName             string
+			localSize, argSize int
+			wroteSP            bool
+			haveRetArg         bool
+			retLine            []int
+		)
+
+		flushRet := func() {
+			if fn != nil && fn.vars["ret"] != nil && !haveRetArg && len(retLine) > 0 {
+				v := fn.vars["ret"]
+				for _, line := range retLine {
+					f.Badf(token.NoPos, "%s:%d: [%s] %s: RET without writing to %d-byte ret+%d(FP)", f.name, line, arch, fnName, v.size, v.off)
+				}
+			}
+			retLine = nil
+		}
+		for lineno, line := range lines {
+			lineno++
+
+			badf := func(format string, args ...interface{}) {
+				f.Badf(token.NoPos, "%s:%d: [%s] %s: %s", f.name, lineno, arch, fnName, fmt.Sprintf(format, args...))
+			}
+
+			if arch == "" {
+				// Determine architecture from +build line if possible.
+				if m := asmPlusBuild.FindStringSubmatch(line); m != nil {
+				Fields:
+					for _, fld := range strings.Fields(m[1]) {
+						for _, a := range arches {
+							if a.name == fld {
+								arch = a.name
+								archDef = a
+								break Fields
+							}
+						}
+					}
+				}
+			}
+
+			if m := asmTEXT.FindStringSubmatch(line); m != nil {
+				flushRet()
+				if arch == "" {
+					f.Warnf(token.NoPos, "%s: cannot determine architecture for assembly file", f.name)
+					continue Files
+				}
+				fnName = m[1]
+				fn = knownFunc[m[1]][arch]
+				if fn != nil {
+					size, _ := strconv.Atoi(m[4])
+					if size != fn.size && (m[2] != "7" && !strings.Contains(m[2], "NOSPLIT") || size != 0) {
+						badf("wrong argument size %d; expected $...-%d", size, fn.size)
+					}
+				}
+				localSize, _ = strconv.Atoi(m[3])
+				localSize += archDef.intSize
+				if archDef.lr {
+					// Account for caller's saved LR
+					localSize += archDef.intSize
+				}
+				argSize, _ = strconv.Atoi(m[4])
+				if fn == nil && !strings.Contains(fnName, "<>") {
+					badf("function %s missing Go declaration", fnName)
+				}
+				wroteSP = false
+				haveRetArg = false
+				continue
+			} else if strings.Contains(line, "TEXT") && strings.Contains(line, "SB") {
+				// function, but not visible from Go (didn't match asmTEXT), so stop checking
+				flushRet()
+				fn = nil
+				fnName = ""
+				continue
+			}
+
+			if strings.Contains(line, "RET") {
+				retLine = append(retLine, lineno)
+			}
+
+			if fnName == "" {
+				continue
+			}
+
+			if asmDATA.FindStringSubmatch(line) != nil {
+				fn = nil
+			}
+
+			if archDef == nil {
+				continue
+			}
+
+			if strings.Contains(line, ", "+archDef.stack) || strings.Contains(line, ",\t"+archDef.stack) {
+				wroteSP = true
+				continue
+			}
+
+			for _, m := range asmSP.FindAllStringSubmatch(line, -1) {
+				if m[3] != archDef.stack || wroteSP {
+					continue
+				}
+				off := 0
+				if m[1] != "" {
+					off, _ = strconv.Atoi(m[2])
+				}
+				if off >= localSize {
+					if fn != nil {
+						v := fn.varByOffset[off-localSize]
+						if v != nil {
+							badf("%s should be %s+%d(FP)", m[1], v.name, off-localSize)
+							continue
+						}
+					}
+					if off >= localSize+argSize {
+						badf("use of %s points beyond argument frame", m[1])
+						continue
+					}
+					badf("use of %s to access argument frame", m[1])
+				}
+			}
+
+			if fn == nil {
+				continue
+			}
+
+			for _, m := range asmUnnamedFP.FindAllStringSubmatch(line, -1) {
+				off, _ := strconv.Atoi(m[2])
+				v := fn.varByOffset[off]
+				if v != nil {
+					badf("use of unnamed argument %s; offset %d is %s+%d(FP)", m[1], off, v.name, v.off)
+				} else {
+					badf("use of unnamed argument %s", m[1])
+				}
+			}
+
+			for _, m := range asmNamedFP.FindAllStringSubmatch(line, -1) {
+				name := m[1]
+				off := 0
+				if m[2] != "" {
+					off, _ = strconv.Atoi(m[2])
+				}
+				if name == "ret" || strings.HasPrefix(name, "ret_") {
+					haveRetArg = true
+				}
+				v := fn.vars[name]
+				if v == nil {
+					// Allow argframe+0(FP).
+					if name == "argframe" && off == 0 {
+						continue
+					}
+					v = fn.varByOffset[off]
+					if v != nil {
+						badf("unknown variable %s; offset %d is %s+%d(FP)", name, off, v.name, v.off)
+					} else {
+						badf("unknown variable %s", name)
+					}
+					continue
+				}
+				asmCheckVar(badf, fn, line, m[0], off, v)
+			}
+		}
+		flushRet()
+	}
+}
+
+// asmParseDecl parses a function decl for expected assembly variables.
+func (f *File) asmParseDecl(decl *ast.FuncDecl) map[string]*asmFunc {
+	var (
+		arch   *asmArch
+		fn     *asmFunc
+		offset int
+		failed bool
+	)
+
+	addVar := func(outer string, v asmVar) {
+		if vo := fn.vars[outer]; vo != nil {
+			vo.inner = append(vo.inner, &v)
+		}
+		fn.vars[v.name] = &v
+		for i := 0; i < v.size; i++ {
+			fn.varByOffset[v.off+i] = &v
+		}
+	}
+
+	addParams := func(list []*ast.Field) {
+		for i, fld := range list {
+			// Determine alignment, size, and kind of type in declaration.
+			var align, size int
+			var kind asmKind
+			names := fld.Names
+			typ := f.gofmt(fld.Type)
+			switch t := fld.Type.(type) {
+			default:
+				switch typ {
+				default:
+					f.Warnf(fld.Type.Pos(), "unknown assembly argument type %s", typ)
+					failed = true
+					return
+				case "int8", "uint8", "byte", "bool":
+					size = 1
+				case "int16", "uint16":
+					size = 2
+				case "int32", "uint32", "float32":
+					size = 4
+				case "int64", "uint64", "float64":
+					align = arch.maxAlign
+					size = 8
+				case "int", "uint":
+					size = arch.intSize
+				case "uintptr", "iword", "Word", "Errno", "unsafe.Pointer":
+					size = arch.ptrSize
+				case "string", "ErrorString":
+					size = arch.ptrSize * 2
+					align = arch.ptrSize
+					kind = asmString
+				}
+			case *ast.ChanType, *ast.FuncType, *ast.MapType, *ast.StarExpr:
+				size = arch.ptrSize
+			case *ast.InterfaceType:
+				align = arch.ptrSize
+				size = 2 * arch.ptrSize
+				if len(t.Methods.List) > 0 {
+					kind = asmInterface
+				} else {
+					kind = asmEmptyInterface
+				}
+			case *ast.ArrayType:
+				if t.Len == nil {
+					size = arch.ptrSize + 2*arch.intSize
+					align = arch.ptrSize
+					kind = asmSlice
+					break
+				}
+				f.Warnf(fld.Type.Pos(), "unsupported assembly argument type %s", typ)
+				failed = true
+			case *ast.StructType:
+				f.Warnf(fld.Type.Pos(), "unsupported assembly argument type %s", typ)
+				failed = true
+			}
+			if align == 0 {
+				align = size
+			}
+			if kind == 0 {
+				kind = asmKind(size)
+			}
+			offset += -offset & (align - 1)
+
+			// Create variable for each name being declared with this type.
+			if len(names) == 0 {
+				name := "unnamed"
+				if decl.Type.Results != nil && len(decl.Type.Results.List) > 0 && &list[0] == &decl.Type.Results.List[0] && i == 0 {
+					// Assume assembly will refer to single unnamed result as r.
+					name = "ret"
+				}
+				names = []*ast.Ident{{Name: name}}
+			}
+			for _, id := range names {
+				name := id.Name
+				addVar("", asmVar{
+					name: name,
+					kind: kind,
+					typ:  typ,
+					off:  offset,
+					size: size,
+				})
+				switch kind {
+				case 8:
+					if arch.ptrSize == 4 {
+						w1, w2 := "lo", "hi"
+						if arch.bigEndian {
+							w1, w2 = w2, w1
+						}
+						addVar(name, asmVar{
+							name: name + "_" + w1,
+							kind: 4,
+							typ:  "half " + typ,
+							off:  offset,
+							size: 4,
+						})
+						addVar(name, asmVar{
+							name: name + "_" + w2,
+							kind: 4,
+							typ:  "half " + typ,
+							off:  offset + 4,
+							size: 4,
+						})
+					}
+
+				case asmEmptyInterface:
+					addVar(name, asmVar{
+						name: name + "_type",
+						kind: asmKind(arch.ptrSize),
+						typ:  "interface type",
+						off:  offset,
+						size: arch.ptrSize,
+					})
+					addVar(name, asmVar{
+						name: name + "_data",
+						kind: asmKind(arch.ptrSize),
+						typ:  "interface data",
+						off:  offset + arch.ptrSize,
+						size: arch.ptrSize,
+					})
+
+				case asmInterface:
+					addVar(name, asmVar{
+						name: name + "_itable",
+						kind: asmKind(arch.ptrSize),
+						typ:  "interface itable",
+						off:  offset,
+						size: arch.ptrSize,
+					})
+					addVar(name, asmVar{
+						name: name + "_data",
+						kind: asmKind(arch.ptrSize),
+						typ:  "interface data",
+						off:  offset + arch.ptrSize,
+						size: arch.ptrSize,
+					})
+
+				case asmSlice:
+					addVar(name, asmVar{
+						name: name + "_base",
+						kind: asmKind(arch.ptrSize),
+						typ:  "slice base",
+						off:  offset,
+						size: arch.ptrSize,
+					})
+					addVar(name, asmVar{
+						name: name + "_len",
+						kind: asmKind(arch.intSize),
+						typ:  "slice len",
+						off:  offset + arch.ptrSize,
+						size: arch.intSize,
+					})
+					addVar(name, asmVar{
+						name: name + "_cap",
+						kind: asmKind(arch.intSize),
+						typ:  "slice cap",
+						off:  offset + arch.ptrSize + arch.intSize,
+						size: arch.intSize,
+					})
+
+				case asmString:
+					addVar(name, asmVar{
+						name: name + "_base",
+						kind: asmKind(arch.ptrSize),
+						typ:  "string base",
+						off:  offset,
+						size: arch.ptrSize,
+					})
+					addVar(name, asmVar{
+						name: name + "_len",
+						kind: asmKind(arch.intSize),
+						typ:  "string len",
+						off:  offset + arch.ptrSize,
+						size: arch.intSize,
+					})
+				}
+				offset += size
+			}
+		}
+	}
+
+	m := make(map[string]*asmFunc)
+	for _, arch = range arches {
+		fn = &asmFunc{
+			arch:        arch,
+			vars:        make(map[string]*asmVar),
+			varByOffset: make(map[int]*asmVar),
+		}
+		offset = 0
+		addParams(decl.Type.Params.List)
+		if decl.Type.Results != nil && len(decl.Type.Results.List) > 0 {
+			offset += -offset & (arch.maxAlign - 1)
+			addParams(decl.Type.Results.List)
+		}
+		fn.size = offset
+		m[arch.name] = fn
+	}
+
+	if failed {
+		return nil
+	}
+	return m
+}
+
+// asmCheckVar checks a single variable reference.
+func asmCheckVar(badf func(string, ...interface{}), fn *asmFunc, line, expr string, off int, v *asmVar) {
+	m := asmOpcode.FindStringSubmatch(line)
+	if m == nil {
+		if !strings.HasPrefix(strings.TrimSpace(line), "//") {
+			badf("cannot find assembly opcode")
+		}
+		return
+	}
+
+	// Determine operand sizes from instruction.
+	// Typically the suffix suffices, but there are exceptions.
+	var src, dst, kind asmKind
+	op := m[1]
+	switch fn.arch.name + "." + op {
+	case "386.FMOVLP":
+		src, dst = 8, 4
+	case "arm.MOVD":
+		src = 8
+	case "arm.MOVW":
+		src = 4
+	case "arm.MOVH", "arm.MOVHU":
+		src = 2
+	case "arm.MOVB", "arm.MOVBU":
+		src = 1
+	// LEA* opcodes don't really read the second arg.
+	// They just take the address of it.
+	case "386.LEAL":
+		dst = 4
+	case "amd64.LEAQ":
+		dst = 8
+	case "amd64p32.LEAL":
+		dst = 4
+	default:
+		switch fn.arch.name {
+		case "386", "amd64":
+			if strings.HasPrefix(op, "F") && (strings.HasSuffix(op, "D") || strings.HasSuffix(op, "DP")) {
+				// FMOVDP, FXCHD, etc
+				src = 8
+				break
+			}
+			if strings.HasPrefix(op, "P") && strings.HasSuffix(op, "RD") {
+				// PINSRD, PEXTRD, etc
+				src = 4
+				break
+			}
+			if strings.HasPrefix(op, "F") && (strings.HasSuffix(op, "F") || strings.HasSuffix(op, "FP")) {
+				// FMOVFP, FXCHF, etc
+				src = 4
+				break
+			}
+			if strings.HasSuffix(op, "SD") {
+				// MOVSD, SQRTSD, etc
+				src = 8
+				break
+			}
+			if strings.HasSuffix(op, "SS") {
+				// MOVSS, SQRTSS, etc
+				src = 4
+				break
+			}
+			if strings.HasPrefix(op, "SET") {
+				// SETEQ, etc
+				src = 1
+				break
+			}
+			switch op[len(op)-1] {
+			case 'B':
+				src = 1
+			case 'W':
+				src = 2
+			case 'L':
+				src = 4
+			case 'D', 'Q':
+				src = 8
+			}
+		case "ppc64", "ppc64le":
+			// Strip standard suffixes to reveal size letter.
+			m := ppc64Suff.FindStringSubmatch(op)
+			if m != nil {
+				switch m[1][0] {
+				case 'B':
+					src = 1
+				case 'H':
+					src = 2
+				case 'W':
+					src = 4
+				case 'D':
+					src = 8
+				}
+			}
+		case "mips64", "mips64le":
+			switch op {
+			case "MOVB", "MOVBU":
+				src = 1
+			case "MOVH", "MOVHU":
+				src = 2
+			case "MOVW", "MOVWU", "MOVF":
+				src = 4
+			case "MOVV", "MOVD":
+				src = 8
+			}
+		}
+	}
+	if dst == 0 {
+		dst = src
+	}
+
+	// Determine whether the match we're holding
+	// is the first or second argument.
+	if strings.Index(line, expr) > strings.Index(line, ",") {
+		kind = dst
+	} else {
+		kind = src
+	}
+
+	vk := v.kind
+	vt := v.typ
+	switch vk {
+	case asmInterface, asmEmptyInterface, asmString, asmSlice:
+		// allow reference to first word (pointer)
+		vk = v.inner[0].kind
+		vt = v.inner[0].typ
+	}
+
+	if off != v.off {
+		var inner bytes.Buffer
+		for i, vi := range v.inner {
+			if len(v.inner) > 1 {
+				fmt.Fprintf(&inner, ",")
+			}
+			fmt.Fprintf(&inner, " ")
+			if i == len(v.inner)-1 {
+				fmt.Fprintf(&inner, "or ")
+			}
+			fmt.Fprintf(&inner, "%s+%d(FP)", vi.name, vi.off)
+		}
+		badf("invalid offset %s; expected %s+%d(FP)%s", expr, v.name, v.off, inner.String())
+		return
+	}
+	if kind != 0 && kind != vk {
+		var inner bytes.Buffer
+		if len(v.inner) > 0 {
+			fmt.Fprintf(&inner, " containing")
+			for i, vi := range v.inner {
+				if i > 0 && len(v.inner) > 2 {
+					fmt.Fprintf(&inner, ",")
+				}
+				fmt.Fprintf(&inner, " ")
+				if i > 0 && i == len(v.inner)-1 {
+					fmt.Fprintf(&inner, "and ")
+				}
+				fmt.Fprintf(&inner, "%s+%d(FP)", vi.name, vi.off)
+			}
+		}
+		badf("invalid %s of %s; %s is %d-byte value%s", op, expr, vt, vk, inner.String())
+	}
+}

tools/vendor/github.com/dnephin/govet/assign.go

@@ -0,0 +1,49 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+/*
+This file contains the code to check for useless assignments.
+*/
+
+package main
+
+import (
+	"go/ast"
+	"go/token"
+	"reflect"
+)
+
+func init() {
+	register("assign",
+		"check for useless assignments",
+		checkAssignStmt,
+		assignStmt)
+}
+
+// TODO: should also check for assignments to struct fields inside methods
+// that are on T instead of *T.
+
+// checkAssignStmt checks for assignments of the form "<expr> = <expr>".
+// These are almost always useless, and even when they aren't they are usually a mistake.
+func checkAssignStmt(f *File, node ast.Node) {
+	stmt := node.(*ast.AssignStmt)
+	if stmt.Tok != token.ASSIGN {
+		return // ignore :=
+	}
+	if len(stmt.Lhs) != len(stmt.Rhs) {
+		// If LHS and RHS have different cardinality, they can't be the same.
+		return
+	}
+	for i, lhs := range stmt.Lhs {
+		rhs := stmt.Rhs[i]
+		if reflect.TypeOf(lhs) != reflect.TypeOf(rhs) {
+			continue // short-circuit the heavy-weight gofmt check
+		}
+		le := f.gofmt(lhs)
+		re := f.gofmt(rhs)
+		if le == re {
+			f.Badf(stmt.Pos(), "self-assignment of %s to %s", re, le)
+		}
+	}
+}

tools/vendor/github.com/dnephin/govet/atomic.go

@@ -0,0 +1,69 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"go/ast"
+	"go/token"
+)
+
+func init() {
+	register("atomic",
+		"check for common mistaken usages of the sync/atomic package",
+		checkAtomicAssignment,
+		assignStmt)
+}
+
+// checkAtomicAssignment walks the assignment statement checking for common
+// mistaken usage of atomic package, such as: x = atomic.AddUint64(&x, 1)
+func checkAtomicAssignment(f *File, node ast.Node) {
+	n := node.(*ast.AssignStmt)
+	if len(n.Lhs) != len(n.Rhs) {
+		return
+	}
+	if len(n.Lhs) == 1 && n.Tok == token.DEFINE {
+		return
+	}
+
+	for i, right := range n.Rhs {
+		call, ok := right.(*ast.CallExpr)
+		if !ok {
+			continue
+		}
+		sel, ok := call.Fun.(*ast.SelectorExpr)
+		if !ok {
+			continue
+		}
+		pkg, ok := sel.X.(*ast.Ident)
+		if !ok || pkg.Name != "atomic" {
+			continue
+		}
+
+		switch sel.Sel.Name {
+		case "AddInt32", "AddInt64", "AddUint32", "AddUint64", "AddUintptr":
+			f.checkAtomicAddAssignment(n.Lhs[i], call)
+		}
+	}
+}
+
+// checkAtomicAddAssignment walks the atomic.Add* method calls checking for assigning the return value
+// to the same variable being used in the operation
+func (f *File) checkAtomicAddAssignment(left ast.Expr, call *ast.CallExpr) {
+	if len(call.Args) != 2 {
+		return
+	}
+	arg := call.Args[0]
+	broken := false
+
+	if uarg, ok := arg.(*ast.UnaryExpr); ok && uarg.Op == token.AND {
+		broken = f.gofmt(left) == f.gofmt(uarg.X)
+	} else if star, ok := left.(*ast.StarExpr); ok {
+		broken = f.gofmt(star.X) == f.gofmt(arg)
+	}
+
+	if broken {
+		f.Bad(left.Pos(), "direct assignment to atomic value")
+	}
+}

tools/vendor/github.com/dnephin/govet/bool.go

@@ -0,0 +1,186 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file contains boolean condition tests.
+
+package main
+
+import (
+	"go/ast"
+	"go/token"
+)
+
+func init() {
+	register("bool",
+		"check for mistakes involving boolean operators",
+		checkBool,
+		binaryExpr)
+}
+
+func checkBool(f *File, n ast.Node) {
+	e := n.(*ast.BinaryExpr)
+
+	var op boolOp
+	switch e.Op {
+	case token.LOR:
+		op = or
+	case token.LAND:
+		op = and
+	default:
+		return
+	}
+
+	comm := op.commutativeSets(e)
+	for _, exprs := range comm {
+		op.checkRedundant(f, exprs)
+		op.checkSuspect(f, exprs)
+	}
+}
+
+type boolOp struct {
+	name  string
+	tok   token.Token // token corresponding to this operator
+	badEq token.Token // token corresponding to the equality test that should not be used with this operator
+}
+
+var (
+	or  = boolOp{"or", token.LOR, token.NEQ}
+	and = boolOp{"and", token.LAND, token.EQL}
+)
+
+// commutativeSets returns all side effect free sets of
+// expressions in e that are connected by op.
+// For example, given 'a || b || f() || c || d' with the or op,
+// commutativeSets returns {{b, a}, {d, c}}.
+func (op boolOp) commutativeSets(e *ast.BinaryExpr) [][]ast.Expr {
+	exprs := op.split(e)
+
+	// Partition the slice of expressions into commutative sets.
+	i := 0
+	var sets [][]ast.Expr
+	for j := 0; j <= len(exprs); j++ {
+		if j == len(exprs) || hasSideEffects(exprs[j]) {
+			if i < j {
+				sets = append(sets, exprs[i:j])
+			}
+			i = j + 1
+		}
+	}
+
+	return sets
+}
+
+// checkRedundant checks for expressions of the form
+//   e && e
+//   e || e
+// Exprs must contain only side effect free expressions.
+func (op boolOp) checkRedundant(f *File, exprs []ast.Expr) {
+	seen := make(map[string]bool)
+	for _, e := range exprs {
+		efmt := f.gofmt(e)
+		if seen[efmt] {
+			f.Badf(e.Pos(), "redundant %s: %s %s %s", op.name, efmt, op.tok, efmt)
+		} else {
+			seen[efmt] = true
+		}
+	}
+}
+
+// checkSuspect checks for expressions of the form
+//   x != c1 || x != c2
+//   x == c1 && x == c2
+// where c1 and c2 are constant expressions.
+// If c1 and c2 are the same then it's redundant;
+// if c1 and c2 are different then it's always true or always false.
+// Exprs must contain only side effect free expressions.
+func (op boolOp) checkSuspect(f *File, exprs []ast.Expr) {
+	// seen maps from expressions 'x' to equality expressions 'x != c'.
+	seen := make(map[string]string)
+
+	for _, e := range exprs {
+		bin, ok := e.(*ast.BinaryExpr)
+		if !ok || bin.Op != op.badEq {
+			continue
+		}
+
+		// In order to avoid false positives, restrict to cases
+		// in which one of the operands is constant. We're then
+		// interested in the other operand.
+		// In the rare case in which both operands are constant
+		// (e.g. runtime.GOOS and "windows"), we'll only catch
+		// mistakes if the LHS is repeated, which is how most
+		// code is written.
+		var x ast.Expr
+		switch {
+		case f.pkg.types[bin.Y].Value != nil:
+			x = bin.X
+		case f.pkg.types[bin.X].Value != nil:
+			x = bin.Y
+		default:
+			continue
+		}
+
+		// e is of the form 'x != c' or 'x == c'.
+		xfmt := f.gofmt(x)
+		efmt := f.gofmt(e)
+		if prev, found := seen[xfmt]; found {
+			// checkRedundant handles the case in which efmt == prev.
+			if efmt != prev {
+				f.Badf(e.Pos(), "suspect %s: %s %s %s", op.name, efmt, op.tok, prev)
+			}
+		} else {
+			seen[xfmt] = efmt
+		}
+	}
+}
+
+// hasSideEffects reports whether evaluation of e has side effects.
+func hasSideEffects(e ast.Expr) bool {
+	safe := true
+	ast.Inspect(e, func(node ast.Node) bool {
+		switch n := node.(type) {
+		// Using CallExpr here will catch conversions
+		// as well as function and method invocations.
+		// We'll live with the false negatives for now.
+		case *ast.CallExpr:
+			safe = false
+			return false
+		case *ast.UnaryExpr:
+			if n.Op == token.ARROW {
+				safe = false
+				return false
+			}
+		}
+		return true
+	})
+	return !safe
+}
+
+// split returns a slice of all subexpressions in e that are connected by op.
+// For example, given 'a || (b || c) || d' with the or op,
+// split returns []{d, c, b, a}.
+func (op boolOp) split(e ast.Expr) (exprs []ast.Expr) {
+	for {
+		e = unparen(e)
+		if b, ok := e.(*ast.BinaryExpr); ok && b.Op == op.tok {
+			exprs = append(exprs, op.split(b.Y)...)
+			e = b.X
+		} else {
+			exprs = append(exprs, e)
+			break
+		}
+	}
+	return
+}
+
+// unparen returns e with any enclosing parentheses stripped.
+func unparen(e ast.Expr) ast.Expr {
+	for {
+		p, ok := e.(*ast.ParenExpr)
+		if !ok {
+			return e
+		}
+		e = p.X
+	}
+}

tools/vendor/github.com/dnephin/govet/buildtag.go

@@ -0,0 +1,91 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"os"
+	"strings"
+	"unicode"
+)
+
+var (
+	nl         = []byte("\n")
+	slashSlash = []byte("//")
+	plusBuild  = []byte("+build")
+)
+
+// checkBuildTag checks that build tags are in the correct location and well-formed.
+func checkBuildTag(name string, data []byte) {
+	if !vet("buildtags") {
+		return
+	}
+	lines := bytes.SplitAfter(data, nl)
+
+	// Determine cutpoint where +build comments are no longer valid.
+	// They are valid in leading // comments in the file followed by
+	// a blank line.
+	var cutoff int
+	for i, line := range lines {
+		line = bytes.TrimSpace(line)
+		if len(line) == 0 {
+			cutoff = i
+			continue
+		}
+		if bytes.HasPrefix(line, slashSlash) {
+			continue
+		}
+		break
+	}
+
+	for i, line := range lines {
+		line = bytes.TrimSpace(line)
+		if !bytes.HasPrefix(line, slashSlash) {
+			continue
+		}
+		text := bytes.TrimSpace(line[2:])
+		if bytes.HasPrefix(text, plusBuild) {
+			fields := bytes.Fields(text)
+			if !bytes.Equal(fields[0], plusBuild) {
+				// Comment is something like +buildasdf not +build.
+				fmt.Fprintf(os.Stderr, "%s:%d: possible malformed +build comment\n", name, i+1)
+				continue
+			}
+			if i >= cutoff {
+				fmt.Fprintf(os.Stderr, "%s:%d: +build comment must appear before package clause and be followed by a blank line\n", name, i+1)
+				setExit(1)
+				continue
+			}
+			// Check arguments.
+		Args:
+			for _, arg := range fields[1:] {
+				for _, elem := range strings.Split(string(arg), ",") {
+					if strings.HasPrefix(elem, "!!") {
+						fmt.Fprintf(os.Stderr, "%s:%d: invalid double negative in build constraint: %s\n", name, i+1, arg)
+						setExit(1)
+						break Args
+					}
+					if strings.HasPrefix(elem, "!") {
+						elem = elem[1:]
+					}
+					for _, c := range elem {
+						if !unicode.IsLetter(c) && !unicode.IsDigit(c) && c != '_' && c != '.' {
+							fmt.Fprintf(os.Stderr, "%s:%d: invalid non-alphanumeric build constraint: %s\n", name, i+1, arg)
+							setExit(1)
+							break Args
+						}
+					}
+				}
+			}
+			continue
+		}
+		// Comment with +build but not at beginning.
+		if bytes.Contains(line, plusBuild) && i < cutoff {
+			fmt.Fprintf(os.Stderr, "%s:%d: possible malformed +build comment\n", name, i+1)
+			continue
+		}
+	}
+}

tools/vendor/github.com/dnephin/govet/cgo.go

@@ -0,0 +1,130 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Check for invalid cgo pointer passing.
+// This looks for code that uses cgo to call C code passing values
+// whose types are almost always invalid according to the cgo pointer
+// sharing rules.
+// Specifically, it warns about attempts to pass a Go chan, map, func,
+// or slice to C, either directly, or via a pointer, array, or struct.
+
+package main
+
+import (
+	"go/ast"
+	"go/token"
+	"go/types"
+)
+
+func init() {
+	register("cgocall",
+		"check for types that may not be passed to cgo calls",
+		checkCgoCall,
+		callExpr)
+}
+
+func checkCgoCall(f *File, node ast.Node) {
+	x := node.(*ast.CallExpr)
+
+	// We are only looking for calls to functions imported from
+	// the "C" package.
+	sel, ok := x.Fun.(*ast.SelectorExpr)
+	if !ok {
+		return
+	}
+	id, ok := sel.X.(*ast.Ident)
+	if !ok || id.Name != "C" {
+		return
+	}
+
+	for _, arg := range x.Args {
+		if !typeOKForCgoCall(cgoBaseType(f, arg)) {
+			f.Badf(arg.Pos(), "possibly passing Go type with embedded pointer to C")
+		}
+
+		// Check for passing the address of a bad type.
+		if conv, ok := arg.(*ast.CallExpr); ok && len(conv.Args) == 1 && f.hasBasicType(conv.Fun, types.UnsafePointer) {
+			arg = conv.Args[0]
+		}
+		if u, ok := arg.(*ast.UnaryExpr); ok && u.Op == token.AND {
+			if !typeOKForCgoCall(cgoBaseType(f, u.X)) {
+				f.Badf(arg.Pos(), "possibly passing Go type with embedded pointer to C")
+			}
+		}
+	}
+}
+
+// cgoBaseType tries to look through type conversions involving
+// unsafe.Pointer to find the real type. It converts:
+//   unsafe.Pointer(x) => x
+//   *(*unsafe.Pointer)(unsafe.Pointer(&x)) => x
+func cgoBaseType(f *File, arg ast.Expr) types.Type {
+	switch arg := arg.(type) {
+	case *ast.CallExpr:
+		if len(arg.Args) == 1 && f.hasBasicType(arg.Fun, types.UnsafePointer) {
+			return cgoBaseType(f, arg.Args[0])
+		}
+	case *ast.StarExpr:
+		call, ok := arg.X.(*ast.CallExpr)
+		if !ok || len(call.Args) != 1 {
+			break
+		}
+		// Here arg is *f(v).
+		t := f.pkg.types[call.Fun].Type
+		if t == nil {
+			break
+		}
+		ptr, ok := t.Underlying().(*types.Pointer)
+		if !ok {
+			break
+		}
+		// Here arg is *(*p)(v)
+		elem, ok := ptr.Elem().Underlying().(*types.Basic)
+		if !ok || elem.Kind() != types.UnsafePointer {
+			break
+		}
+		// Here arg is *(*unsafe.Pointer)(v)
+		call, ok = call.Args[0].(*ast.CallExpr)
+		if !ok || len(call.Args) != 1 {
+			break
+		}
+		// Here arg is *(*unsafe.Pointer)(f(v))
+		if !f.hasBasicType(call.Fun, types.UnsafePointer) {
+			break
+		}
+		// Here arg is *(*unsafe.Pointer)(unsafe.Pointer(v))
+		u, ok := call.Args[0].(*ast.UnaryExpr)
+		if !ok || u.Op != token.AND {
+			break
+		}
+		// Here arg is *(*unsafe.Pointer)(unsafe.Pointer(&v))
+		return cgoBaseType(f, u.X)
+	}
+
+	return f.pkg.types[arg].Type
+}
+
+// typeOKForCgoCall returns true if the type of arg is OK to pass to a
+// C function using cgo. This is not true for Go types with embedded
+// pointers.
+func typeOKForCgoCall(t types.Type) bool {
+	if t == nil {
+		return true
+	}
+	switch t := t.Underlying().(type) {
+	case *types.Chan, *types.Map, *types.Signature, *types.Slice:
+		return false
+	case *types.Pointer:
+		return typeOKForCgoCall(t.Elem())
+	case *types.Array:
+		return typeOKForCgoCall(t.Elem())
+	case *types.Struct:
+		for i := 0; i < t.NumFields(); i++ {
+			if !typeOKForCgoCall(t.Field(i).Type()) {
+				return false
+			}
+		}
+	}
+	return true
+}

tools/vendor/github.com/dnephin/govet/composite.go

@@ -0,0 +1,82 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file contains the test for unkeyed struct literals.
+
+package main
+
+import (
+	"github.com/dnephin/govet/internal/whitelist"
+	"flag"
+	"go/ast"
+	"go/types"
+	"strings"
+)
+
+var compositeWhiteList = flag.Bool("compositewhitelist", true, "use composite white list; for testing only")
+
+func init() {
+	register("composites",
+		"check that composite literals used field-keyed elements",
+		checkUnkeyedLiteral,
+		compositeLit)
+}
+
+// checkUnkeyedLiteral checks if a composite literal is a struct literal with
+// unkeyed fields.
+func checkUnkeyedLiteral(f *File, node ast.Node) {
+	cl := node.(*ast.CompositeLit)
+
+	typ := f.pkg.types[cl].Type
+	if typ == nil {
+		// cannot determine composite literals' type, skip it
+		return
+	}
+	typeName := typ.String()
+	if *compositeWhiteList && whitelist.UnkeyedLiteral[typeName] {
+		// skip whitelisted types
+		return
+	}
+	if _, ok := typ.Underlying().(*types.Struct); !ok {
+		// skip non-struct composite literals
+		return
+	}
+	if isLocalType(f, typeName) {
+		// allow unkeyed locally defined composite literal
+		return
+	}
+
+	// check if the CompositeLit contains an unkeyed field
+	allKeyValue := true
+	for _, e := range cl.Elts {
+		if _, ok := e.(*ast.KeyValueExpr); !ok {
+			allKeyValue = false
+			break
+		}
+	}
+	if allKeyValue {
+		// all the composite literal fields are keyed
+		return
+	}
+
+	f.Badf(cl.Pos(), "%s composite literal uses unkeyed fields", typeName)
+}
+
+func isLocalType(f *File, typeName string) bool {
+	if strings.HasPrefix(typeName, "struct{") {
+		// struct literals are local types
+		return true
+	}
+
+	pkgname := f.pkg.path
+	if strings.HasPrefix(typeName, pkgname+".") {
+		return true
+	}
+
+	// treat types as local inside test packages with _test name suffix
+	if strings.HasSuffix(pkgname, "_test") {
+		pkgname = pkgname[:len(pkgname)-len("_test")]
+	}
+	return strings.HasPrefix(typeName, pkgname+".")
+}

tools/vendor/github.com/dnephin/govet/copylock.go

@@ -0,0 +1,239 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file contains the code to check that locks are not passed by value.
+
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"go/ast"
+	"go/token"
+	"go/types"
+)
+
+func init() {
+	register("copylocks",
+		"check that locks are not passed by value",
+		checkCopyLocks,
+		funcDecl, rangeStmt, funcLit, callExpr, assignStmt, genDecl, compositeLit, returnStmt)
+}
+
+// checkCopyLocks checks whether node might
+// inadvertently copy a lock.
+func checkCopyLocks(f *File, node ast.Node) {
+	switch node := node.(type) {
+	case *ast.RangeStmt:
+		checkCopyLocksRange(f, node)
+	case *ast.FuncDecl:
+		checkCopyLocksFunc(f, node.Name.Name, node.Recv, node.Type)
+	case *ast.FuncLit:
+		checkCopyLocksFunc(f, "func", nil, node.Type)
+	case *ast.CallExpr:
+		checkCopyLocksCallExpr(f, node)
+	case *ast.AssignStmt:
+		checkCopyLocksAssign(f, node)
+	case *ast.GenDecl:
+		checkCopyLocksGenDecl(f, node)
+	case *ast.CompositeLit:
+		checkCopyLocksCompositeLit(f, node)
+	case *ast.ReturnStmt:
+		checkCopyLocksReturnStmt(f, node)
+	}
+}
+
+// checkCopyLocksAssign checks whether an assignment
+// copies a lock.
+func checkCopyLocksAssign(f *File, as *ast.AssignStmt) {
+	for i, x := range as.Rhs {
+		if path := lockPathRhs(f, x); path != nil {
+			f.Badf(x.Pos(), "assignment copies lock value to %v: %v", f.gofmt(as.Lhs[i]), path)
+		}
+	}
+}
+
+// checkCopyLocksGenDecl checks whether lock is copied
+// in variable declaration.
+func checkCopyLocksGenDecl(f *File, gd *ast.GenDecl) {
+	if gd.Tok != token.VAR {
+		return
+	}
+	for _, spec := range gd.Specs {
+		valueSpec := spec.(*ast.ValueSpec)
+		for i, x := range valueSpec.Values {
+			if path := lockPathRhs(f, x); path != nil {
+				f.Badf(x.Pos(), "variable declaration copies lock value to %v: %v", valueSpec.Names[i].Name, path)
+			}
+		}
+	}
+}
+
+// checkCopyLocksCompositeLit detects lock copy inside a composite literal
+func checkCopyLocksCompositeLit(f *File, cl *ast.CompositeLit) {
+	for _, x := range cl.Elts {
+		if node, ok := x.(*ast.KeyValueExpr); ok {
+			x = node.Value
+		}
+		if path := lockPathRhs(f, x); path != nil {
+			f.Badf(x.Pos(), "literal copies lock value from %v: %v", f.gofmt(x), path)
+		}
+	}
+}
+
+// checkCopyLocksReturnStmt detects lock copy in return statement
+func checkCopyLocksReturnStmt(f *File, rs *ast.ReturnStmt) {
+	for _, x := range rs.Results {
+		if path := lockPathRhs(f, x); path != nil {
+			f.Badf(x.Pos(), "return copies lock value: %v", path)
+		}
+	}
+}
+
+// checkCopyLocksCallExpr detects lock copy in the arguments to a function call
+func checkCopyLocksCallExpr(f *File, ce *ast.CallExpr) {
+	if id, ok := ce.Fun.(*ast.Ident); ok && id.Name == "new" && f.pkg.types[id].IsBuiltin() {
+		// Skip 'new(Type)' for built-in 'new'
+		return
+	}
+	for _, x := range ce.Args {
+		if path := lockPathRhs(f, x); path != nil {
+			f.Badf(x.Pos(), "function call copies lock value: %v", path)
+		}
+	}
+}
+
+// checkCopyLocksFunc checks whether a function might
+// inadvertently copy a lock, by checking whether
+// its receiver, parameters, or return values
+// are locks.
+func checkCopyLocksFunc(f *File, name string, recv *ast.FieldList, typ *ast.FuncType) {
+	if recv != nil && len(recv.List) > 0 {
+		expr := recv.List[0].Type
+		if path := lockPath(f.pkg.typesPkg, f.pkg.types[expr].Type); path != nil {
+			f.Badf(expr.Pos(), "%s passes lock by value: %v", name, path)
+		}
+	}
+
+	if typ.Params != nil {
+		for _, field := range typ.Params.List {
+			expr := field.Type
+			if path := lockPath(f.pkg.typesPkg, f.pkg.types[expr].Type); path != nil {
+				f.Badf(expr.Pos(), "%s passes lock by value: %v", name, path)
+			}
+		}
+	}
+
+	// Don't check typ.Results. If T has a Lock field it's OK to write
+	//     return T{}
+	// because that is returning the zero value. Leave result checking
+	// to the return statement.
+}
+
+// checkCopyLocksRange checks whether a range statement
+// might inadvertently copy a lock by checking whether
+// any of the range variables are locks.
+func checkCopyLocksRange(f *File, r *ast.RangeStmt) {
+	checkCopyLocksRangeVar(f, r.Tok, r.Key)
+	checkCopyLocksRangeVar(f, r.Tok, r.Value)
+}
+
+func checkCopyLocksRangeVar(f *File, rtok token.Token, e ast.Expr) {
+	if e == nil {
+		return
+	}
+	id, isId := e.(*ast.Ident)
+	if isId && id.Name == "_" {
+		return
+	}
+
+	var typ types.Type
+	if rtok == token.DEFINE {
+		if !isId {
+			return
+		}
+		obj := f.pkg.defs[id]
+		if obj == nil {
+			return
+		}
+		typ = obj.Type()
+	} else {
+		typ = f.pkg.types[e].Type
+	}
+
+	if typ == nil {
+		return
+	}
+	if path := lockPath(f.pkg.typesPkg, typ); path != nil {
+		f.Badf(e.Pos(), "range var %s copies lock: %v", f.gofmt(e), path)
+	}
+}
+
+type typePath []types.Type
+
+// String pretty-prints a typePath.
+func (path typePath) String() string {
+	n := len(path)
+	var buf bytes.Buffer
+	for i := range path {
+		if i > 0 {
+			fmt.Fprint(&buf, " contains ")
+		}
+		// The human-readable path is in reverse order, outermost to innermost.
+		fmt.Fprint(&buf, path[n-i-1].String())
+	}
+	return buf.String()
+}
+
+func lockPathRhs(f *File, x ast.Expr) typePath {
+	if _, ok := x.(*ast.CompositeLit); ok {
+		return nil
+	}
+	if _, ok := x.(*ast.CallExpr); ok {
+		// A call may return a zero value.
+		return nil
+	}
+	if star, ok := x.(*ast.StarExpr); ok {
+		if _, ok := star.X.(*ast.CallExpr); ok {
+			// A call may return a pointer to a zero value.
+			return nil
+		}
+	}
+	return lockPath(f.pkg.typesPkg, f.pkg.types[x].Type)
+}
+
+// lockPath returns a typePath describing the location of a lock value
+// contained in typ. If there is no contained lock, it returns nil.
+func lockPath(tpkg *types.Package, typ types.Type) typePath {
+	if typ == nil {
+		return nil
+	}
+
+	// We're only interested in the case in which the underlying
+	// type is a struct. (Interfaces and pointers are safe to copy.)
+	styp, ok := typ.Underlying().(*types.Struct)
+	if !ok {
+		return nil
+	}
+
+	// We're looking for cases in which a reference to this type
+	// can be locked, but a value cannot. This differentiates
+	// embedded interfaces from embedded values.
+	if plock := types.NewMethodSet(types.NewPointer(typ)).Lookup(tpkg, "Lock"); plock != nil {
+		if lock := types.NewMethodSet(typ).Lookup(tpkg, "Lock"); lock == nil {
+			return []types.Type{typ}
+		}
+	}
+
+	nfields := styp.NumFields()
+	for i := 0; i < nfields; i++ {
+		ftyp := styp.Field(i).Type()
+		subpath := lockPath(tpkg, ftyp)
+		if subpath != nil {
+			return append(subpath, typ)
+		}
+	}
+
+	return nil
+}

tools/vendor/github.com/dnephin/govet/deadcode.go

@@ -0,0 +1,298 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Check for syntactically unreachable code.
+
+package main
+
+import (
+	"go/ast"
+	"go/token"
+)
+
+func init() {
+	register("unreachable",
+		"check for unreachable code",
+		checkUnreachable,
+		funcDecl, funcLit)
+}
+
+type deadState struct {
+	f           *File
+	hasBreak    map[ast.Stmt]bool
+	hasGoto     map[string]bool
+	labels      map[string]ast.Stmt
+	breakTarget ast.Stmt
+
+	reachable bool
+}
+
+// checkUnreachable checks a function body for dead code.
+//
+// TODO(adonovan): use the new cfg package, which is more precise.
+func checkUnreachable(f *File, node ast.Node) {
+	var body *ast.BlockStmt
+	switch n := node.(type) {
+	case *ast.FuncDecl:
+		body = n.Body
+	case *ast.FuncLit:
+		body = n.Body
+	}
+	if body == nil {
+		return
+	}
+
+	d := &deadState{
+		f:        f,
+		hasBreak: make(map[ast.Stmt]bool),
+		hasGoto:  make(map[string]bool),
+		labels:   make(map[string]ast.Stmt),
+	}
+
+	d.findLabels(body)
+
+	d.reachable = true
+	d.findDead(body)
+}
+
+// findLabels gathers information about the labels defined and used by stmt
+// and about which statements break, whether a label is involved or not.
+func (d *deadState) findLabels(stmt ast.Stmt) {
+	switch x := stmt.(type) {
+	default:
+		d.f.Warnf(x.Pos(), "internal error in findLabels: unexpected statement %T", x)
+
+	case *ast.AssignStmt,
+		*ast.BadStmt,
+		*ast.DeclStmt,
+		*ast.DeferStmt,
+		*ast.EmptyStmt,
+		*ast.ExprStmt,
+		*ast.GoStmt,
+		*ast.IncDecStmt,
+		*ast.ReturnStmt,
+		*ast.SendStmt:
+		// no statements inside
+
+	case *ast.BlockStmt:
+		for _, stmt := range x.List {
+			d.findLabels(stmt)
+		}
+
+	case *ast.BranchStmt:
+		switch x.Tok {
+		case token.GOTO:
+			if x.Label != nil {
+				d.hasGoto[x.Label.Name] = true
+			}
+
+		case token.BREAK:
+			stmt := d.breakTarget
+			if x.Label != nil {
+				stmt = d.labels[x.Label.Name]
+			}
+			if stmt != nil {
+				d.hasBreak[stmt] = true
+			}
+		}
+
+	case *ast.IfStmt:
+		d.findLabels(x.Body)
+		if x.Else != nil {
+			d.findLabels(x.Else)
+		}
+
+	case *ast.LabeledStmt:
+		d.labels[x.Label.Name] = x.Stmt
+		d.findLabels(x.Stmt)
+
+	// These cases are all the same, but the x.Body only works
+	// when the specific type of x is known, so the cases cannot
+	// be merged.
+	case *ast.ForStmt:
+		outer := d.breakTarget
+		d.breakTarget = x
+		d.findLabels(x.Body)
+		d.breakTarget = outer
+
+	case *ast.RangeStmt:
+		outer := d.breakTarget
+		d.breakTarget = x
+		d.findLabels(x.Body)
+		d.breakTarget = outer
+
+	case *ast.SelectStmt:
+		outer := d.breakTarget
+		d.breakTarget = x
+		d.findLabels(x.Body)
+		d.breakTarget = outer
+
+	case *ast.SwitchStmt:
+		outer := d.breakTarget
+		d.breakTarget = x
+		d.findLabels(x.Body)
+		d.breakTarget = outer
+
+	case *ast.TypeSwitchStmt:
+		outer := d.breakTarget
+		d.breakTarget = x
+		d.findLabels(x.Body)
+		d.breakTarget = outer
+
+	case *ast.CommClause:
+		for _, stmt := range x.Body {
+			d.findLabels(stmt)
+		}
+
+	case *ast.CaseClause:
+		for _, stmt := range x.Body {
+			d.findLabels(stmt)
+		}
+	}
+}
+
+// findDead walks the statement looking for dead code.
+// If d.reachable is false on entry, stmt itself is dead.
+// When findDead returns, d.reachable tells whether the
+// statement following stmt is reachable.
+func (d *deadState) findDead(stmt ast.Stmt) {
+	// Is this a labeled goto target?
+	// If so, assume it is reachable due to the goto.
+	// This is slightly conservative, in that we don't
+	// check that the goto is reachable, so
+	//	L: goto L
+	// will not provoke a warning.
+	// But it's good enough.
+	if x, isLabel := stmt.(*ast.LabeledStmt); isLabel && d.hasGoto[x.Label.Name] {
+		d.reachable = true
+	}
+
+	if !d.reachable {
+		switch stmt.(type) {
+		case *ast.EmptyStmt:
+			// do not warn about unreachable empty statements
+		default:
+			d.f.Bad(stmt.Pos(), "unreachable code")
+			d.reachable = true // silence error about next statement
+		}
+	}
+
+	switch x := stmt.(type) {
+	default:
+		d.f.Warnf(x.Pos(), "internal error in findDead: unexpected statement %T", x)
+
+	case *ast.AssignStmt,
+		*ast.BadStmt,
+		*ast.DeclStmt,
+		*ast.DeferStmt,
+		*ast.EmptyStmt,
+		*ast.GoStmt,
+		*ast.IncDecStmt,
+		*ast.SendStmt:
+		// no control flow
+
+	case *ast.BlockStmt:
+		for _, stmt := range x.List {
+			d.findDead(stmt)
+		}
+
+	case *ast.BranchStmt:
+		switch x.Tok {
+		case token.BREAK, token.GOTO, token.FALLTHROUGH:
+			d.reachable = false
+		case token.CONTINUE:
+			// NOTE: We accept "continue" statements as terminating.
+			// They are not necessary in the spec definition of terminating,
+			// because a continue statement cannot be the final statement
+			// before a return. But for the more general problem of syntactically
+			// identifying dead code, continue redirects control flow just
+			// like the other terminating statements.
+			d.reachable = false
+		}
+
+	case *ast.ExprStmt:
+		// Call to panic?
+		call, ok := x.X.(*ast.CallExpr)
+		if ok {
+			name, ok := call.Fun.(*ast.Ident)
+			if ok && name.Name == "panic" && name.Obj == nil {
+				d.reachable = false
+			}
+		}
+
+	case *ast.ForStmt:
+		d.findDead(x.Body)
+		d.reachable = x.Cond != nil || d.hasBreak[x]
+
+	case *ast.IfStmt:
+		d.findDead(x.Body)
+		if x.Else != nil {
+			r := d.reachable
+			d.reachable = true
+			d.findDead(x.Else)
+			d.reachable = d.reachable || r
+		} else {
+			// might not have executed if statement
+			d.reachable = true
+		}
+
+	case *ast.LabeledStmt:
+		d.findDead(x.Stmt)
+
+	case *ast.RangeStmt:
+		d.findDead(x.Body)
+		d.reachable = true
+
+	case *ast.ReturnStmt:
+		d.reachable = false
+
+	case *ast.SelectStmt:
+		// NOTE: Unlike switch and type switch below, we don't care
+		// whether a select has a default, because a select without a
+		// default blocks until one of the cases can run. That's different
+		// from a switch without a default, which behaves like it has
+		// a default with an empty body.
+		anyReachable := false
+		for _, comm := range x.Body.List {
+			d.reachable = true
+			for _, stmt := range comm.(*ast.CommClause).Body {
+				d.findDead(stmt)
+			}
+			anyReachable = anyReachable || d.reachable
+		}
+		d.reachable = anyReachable || d.hasBreak[x]
+
+	case *ast.SwitchStmt:
+		anyReachable := false
+		hasDefault := false
+		for _, cas := range x.Body.List {
+			cc := cas.(*ast.CaseClause)
+			if cc.List == nil {
+				hasDefault = true
+			}
+			d.reachable = true
+			for _, stmt := range cc.Body {
+				d.findDead(stmt)
+			}
+			anyReachable = anyReachable || d.reachable
+		}
+		d.reachable = anyReachable || d.hasBreak[x] || !hasDefault
+
+	case *ast.TypeSwitchStmt:
+		anyReachable := false
+		hasDefault := false
+		for _, cas := range x.Body.List {
+			cc := cas.(*ast.CaseClause)
+			if cc.List == nil {
+				hasDefault = true
+			}
+			d.reachable = true
+			for _, stmt := range cc.Body {
+				d.findDead(stmt)
+			}
+			anyReachable = anyReachable || d.reachable
+		}
+		d.reachable = anyReachable || d.hasBreak[x] || !hasDefault
+	}
+}

tools/vendor/github.com/dnephin/govet/doc.go

@@ -0,0 +1,205 @@
+// Copyright 2010 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+/*
+
+Vet examines Go source code and reports suspicious constructs, such as Printf
+calls whose arguments do not align with the format string. Vet uses heuristics
+that do not guarantee all reports are genuine problems, but it can find errors
+not caught by the compilers.
+
+It can be invoked three ways:
+
+By package, from the go tool:
+	go vet package/path/name
+vets the package whose path is provided.
+
+By files:
+	go tool vet source/directory/*.go
+vets the files named, all of which must be in the same package.
+
+By directory:
+	go tool vet source/directory
+recursively descends the directory, vetting each package it finds.
+
+Vet's exit code is 2 for erroneous invocation of the tool, 1 if a
+problem was reported, and 0 otherwise. Note that the tool does not
+check every possible problem and depends on unreliable heuristics
+so it should be used as guidance only, not as a firm indicator of
+program correctness.
+
+By default the -all flag is set so all checks are performed.
+If any flags are explicitly set to true, only those tests are run. Conversely, if
+any flag is explicitly set to false, only those tests are disabled.  Thus -printf=true
+runs the printf check, -printf=false runs all checks except the printf check.
+
+Available checks:
+
+Assembly declarations
+
+Flag: -asmdecl
+
+Mismatches between assembly files and Go function declarations.
+
+Useless assignments
+
+Flag: -assign
+
+Check for useless assignments.
+
+Atomic mistakes
+
+Flag: -atomic
+
+Common mistaken usages of the sync/atomic package.
+
+Boolean conditions
+
+Flag: -bool
+
+Mistakes involving boolean operators.
+
+Build tags
+
+Flag: -buildtags
+
+Badly formed or misplaced +build tags.
+
+Invalid uses of cgo
+
+Flag: -cgocall
+
+Detect some violations of the cgo pointer passing rules.
+
+Unkeyed composite literals
+
+Flag: -composites
+
+Composite struct literals that do not use the field-keyed syntax.
+
+Copying locks
+
+Flag: -copylocks
+
+Locks that are erroneously passed by value.
+
+Tests, benchmarks and documentation examples
+
+Flag: -tests
+
+Mistakes involving tests including functions with incorrect names or signatures
+and example tests that document identifiers not in the package.
+
+Failure to call the cancelation function returned by context.WithCancel.
+
+Flag: -lostcancel
+
+The cancelation function returned by context.WithCancel, WithTimeout,
+and WithDeadline must be called or the new context will remain live
+until its parent context is cancelled.
+(The background context is never cancelled.)
+
+Methods
+
+Flag: -methods
+
+Non-standard signatures for methods with familiar names, including:
+	Format GobEncode GobDecode MarshalJSON MarshalXML
+	Peek ReadByte ReadFrom ReadRune Scan Seek
+	UnmarshalJSON UnreadByte UnreadRune WriteByte
+	WriteTo
+
+Nil function comparison
+
+Flag: -nilfunc
+
+Comparisons between functions and nil.
+
+Printf family
+
+Flag: -printf
+
+Suspicious calls to functions in the Printf family, including any functions
+with these names, disregarding case:
+	Print Printf Println
+	Fprint Fprintf Fprintln
+	Sprint Sprintf Sprintln
+	Error Errorf
+	Fatal Fatalf
+	Log Logf
+	Panic Panicf Panicln
+The -printfuncs flag can be used to redefine this list.
+If the function name ends with an 'f', the function is assumed to take
+a format descriptor string in the manner of fmt.Printf. If not, vet
+complains about arguments that look like format descriptor strings.
+
+It also checks for errors such as using a Writer as the first argument of
+Printf.
+
+Struct tags
+
+Range loop variables
+
+Flag: -rangeloops
+
+Incorrect uses of range loop variables in closures.
+
+Shadowed variables
+
+Flag: -shadow=false (experimental; must be set explicitly)
+
+Variables that may have been unintentionally shadowed.
+
+Shifts
+
+Flag: -shift
+
+Shifts equal to or longer than the variable's length.
+
+Flag: -structtags
+
+Struct tags that do not follow the format understood by reflect.StructTag.Get.
+Well-known encoding struct tags (json, xml) used with unexported fields.
+
+Unreachable code
+
+Flag: -unreachable
+
+Unreachable code.
+
+Misuse of unsafe Pointers
+
+Flag: -unsafeptr
+
+Likely incorrect uses of unsafe.Pointer to convert integers to pointers.
+A conversion from uintptr to unsafe.Pointer is invalid if it implies that
+there is a uintptr-typed word in memory that holds a pointer value,
+because that word will be invisible to stack copying and to the garbage
+collector.
+
+Unused result of certain function calls
+
+Flag: -unusedresult
+
+Calls to well-known functions and methods that return a value that is
+discarded.  By default, this includes functions like fmt.Errorf and
+fmt.Sprintf and methods like String and Error. The flags -unusedfuncs
+and -unusedstringmethods control the set.
+
+Other flags
+
+These flags configure the behavior of vet:
+
+	-all (default true)
+		Enable all non-experimental checks.
+	-v
+		Verbose mode
+	-printfuncs
+		A comma-separated list of print-like function names
+		to supplement the standard list.
+		For more information, see the discussion of the -printf flag.
+	-shadowstrict
+		Whether to be strict about shadowing; can be noisy.
+*/
+package main

tools/vendor/github.com/dnephin/govet/internal/cfg/builder.go

@@ -0,0 +1,512 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package cfg
+
+// This file implements the CFG construction pass.
+
+import (
+	"fmt"
+	"go/ast"
+	"go/token"
+)
+
+type builder struct {
+	cfg       *CFG
+	mayReturn func(*ast.CallExpr) bool
+	current   *Block
+	lblocks   map[*ast.Object]*lblock // labeled blocks
+	targets   *targets                // linked stack of branch targets
+}
+
+func (b *builder) stmt(_s ast.Stmt) {
+	// The label of the current statement.  If non-nil, its _goto
+	// target is always set; its _break and _continue are set only
+	// within the body of switch/typeswitch/select/for/range.
+	// It is effectively an additional default-nil parameter of stmt().
+	var label *lblock
+start:
+	switch s := _s.(type) {
+	case *ast.BadStmt,
+		*ast.SendStmt,
+		*ast.IncDecStmt,
+		*ast.GoStmt,
+		*ast.DeferStmt,
+		*ast.EmptyStmt,
+		*ast.AssignStmt:
+		// No effect on control flow.
+		b.add(s)
+
+	case *ast.ExprStmt:
+		b.add(s)
+		if call, ok := s.X.(*ast.CallExpr); ok && !b.mayReturn(call) {
+			// Calls to panic, os.Exit, etc, never return.
+			b.current = b.newUnreachableBlock("unreachable.call")
+		}
+
+	case *ast.DeclStmt:
+		// Treat each var ValueSpec as a separate statement.
+		d := s.Decl.(*ast.GenDecl)
+		if d.Tok == token.VAR {
+			for _, spec := range d.Specs {
+				if spec, ok := spec.(*ast.ValueSpec); ok {
+					b.add(spec)
+				}
+			}
+		}
+
+	case *ast.LabeledStmt:
+		label = b.labeledBlock(s.Label)
+		b.jump(label._goto)
+		b.current = label._goto
+		_s = s.Stmt
+		goto start // effectively: tailcall stmt(g, s.Stmt, label)
+
+	case *ast.ReturnStmt:
+		b.add(s)
+		b.current = b.newUnreachableBlock("unreachable.return")
+
+	case *ast.BranchStmt:
+		var block *Block
+		switch s.Tok {
+		case token.BREAK:
+			if s.Label != nil {
+				if lb := b.labeledBlock(s.Label); lb != nil {
+					block = lb._break
+				}
+			} else {
+				for t := b.targets; t != nil && block == nil; t = t.tail {
+					block = t._break
+				}
+			}
+
+		case token.CONTINUE:
+			if s.Label != nil {
+				if lb := b.labeledBlock(s.Label); lb != nil {
+					block = lb._continue
+				}
+			} else {
+				for t := b.targets; t != nil && block == nil; t = t.tail {
+					block = t._continue
+				}
+			}
+
+		case token.FALLTHROUGH:
+			for t := b.targets; t != nil; t = t.tail {
+				block = t._fallthrough
+			}
+
+		case token.GOTO:
+			if s.Label != nil {
+				block = b.labeledBlock(s.Label)._goto
+			}
+		}
+		if block == nil {
+			block = b.newBlock("undefined.branch")
+		}
+		b.jump(block)
+		b.current = b.newUnreachableBlock("unreachable.branch")
+
+	case *ast.BlockStmt:
+		b.stmtList(s.List)
+
+	case *ast.IfStmt:
+		if s.Init != nil {
+			b.stmt(s.Init)
+		}
+		then := b.newBlock("if.then")
+		done := b.newBlock("if.done")
+		_else := done
+		if s.Else != nil {
+			_else = b.newBlock("if.else")
+		}
+		b.add(s.Cond)
+		b.ifelse(then, _else)
+		b.current = then
+		b.stmt(s.Body)
+		b.jump(done)
+
+		if s.Else != nil {
+			b.current = _else
+			b.stmt(s.Else)
+			b.jump(done)
+		}
+
+		b.current = done
+
+	case *ast.SwitchStmt:
+		b.switchStmt(s, label)
+
+	case *ast.TypeSwitchStmt:
+		b.typeSwitchStmt(s, label)
+
+	case *ast.SelectStmt:
+		b.selectStmt(s, label)
+
+	case *ast.ForStmt:
+		b.forStmt(s, label)
+
+	case *ast.RangeStmt:
+		b.rangeStmt(s, label)
+
+	default:
+		panic(fmt.Sprintf("unexpected statement kind: %T", s))
+	}
+}
+
+func (b *builder) stmtList(list []ast.Stmt) {
+	for _, s := range list {
+		b.stmt(s)
+	}
+}
+
+func (b *builder) switchStmt(s *ast.SwitchStmt, label *lblock) {
+	if s.Init != nil {
+		b.stmt(s.Init)
+	}
+	if s.Tag != nil {
+		b.add(s.Tag)
+	}
+	done := b.newBlock("switch.done")
+	if label != nil {
+		label._break = done
+	}
+	// We pull the default case (if present) down to the end.
+	// But each fallthrough label must point to the next
+	// body block in source order, so we preallocate a
+	// body block (fallthru) for the next case.
+	// Unfortunately this makes for a confusing block order.
+	var defaultBody *[]ast.Stmt
+	var defaultFallthrough *Block
+	var fallthru, defaultBlock *Block
+	ncases := len(s.Body.List)
+	for i, clause := range s.Body.List {
+		body := fallthru
+		if body == nil {
+			body = b.newBlock("switch.body") // first case only
+		}
+
+		// Preallocate body block for the next case.
+		fallthru = done
+		if i+1 < ncases {
+			fallthru = b.newBlock("switch.body")
+		}
+
+		cc := clause.(*ast.CaseClause)
+		if cc.List == nil {
+			// Default case.
+			defaultBody = &cc.Body
+			defaultFallthrough = fallthru
+			defaultBlock = body
+			continue
+		}
+
+		var nextCond *Block
+		for _, cond := range cc.List {
+			nextCond = b.newBlock("switch.next")
+			b.add(cond) // one half of the tag==cond condition
+			b.ifelse(body, nextCond)
+			b.current = nextCond
+		}
+		b.current = body
+		b.targets = &targets{
+			tail:         b.targets,
+			_break:       done,
+			_fallthrough: fallthru,
+		}
+		b.stmtList(cc.Body)
+		b.targets = b.targets.tail
+		b.jump(done)
+		b.current = nextCond
+	}
+	if defaultBlock != nil {
+		b.jump(defaultBlock)
+		b.current = defaultBlock
+		b.targets = &targets{
+			tail:         b.targets,
+			_break:       done,
+			_fallthrough: defaultFallthrough,
+		}
+		b.stmtList(*defaultBody)
+		b.targets = b.targets.tail
+	}
+	b.jump(done)
+	b.current = done
+}
+
+func (b *builder) typeSwitchStmt(s *ast.TypeSwitchStmt, label *lblock) {
+	if s.Init != nil {
+		b.stmt(s.Init)
+	}
+	if s.Assign != nil {
+		b.add(s.Assign)
+	}
+
+	done := b.newBlock("typeswitch.done")
+	if label != nil {
+		label._break = done
+	}
+	var default_ *ast.CaseClause
+	for _, clause := range s.Body.List {
+		cc := clause.(*ast.CaseClause)
+		if cc.List == nil {
+			default_ = cc
+			continue
+		}
+		body := b.newBlock("typeswitch.body")
+		var next *Block
+		for _, casetype := range cc.List {
+			next = b.newBlock("typeswitch.next")
+			// casetype is a type, so don't call b.add(casetype).
+			// This block logically contains a type assertion,
+			// x.(casetype), but it's unclear how to represent x.
+			_ = casetype
+			b.ifelse(body, next)
+			b.current = next
+		}
+		b.current = body
+		b.typeCaseBody(cc, done)
+		b.current = next
+	}
+	if default_ != nil {
+		b.typeCaseBody(default_, done)
+	} else {
+		b.jump(done)
+	}
+	b.current = done
+}
+
+func (b *builder) typeCaseBody(cc *ast.CaseClause, done *Block) {
+	b.targets = &targets{
+		tail:   b.targets,
+		_break: done,
+	}
+	b.stmtList(cc.Body)
+	b.targets = b.targets.tail
+	b.jump(done)
+}
+
+func (b *builder) selectStmt(s *ast.SelectStmt, label *lblock) {
+	// First evaluate channel expressions.
+	// TODO(adonovan): fix: evaluate only channel exprs here.
+	for _, clause := range s.Body.List {
+		if comm := clause.(*ast.CommClause).Comm; comm != nil {
+			b.stmt(comm)
+		}
+	}
+
+	done := b.newBlock("select.done")
+	if label != nil {
+		label._break = done
+	}
+
+	var defaultBody *[]ast.Stmt
+	for _, cc := range s.Body.List {
+		clause := cc.(*ast.CommClause)
+		if clause.Comm == nil {
+			defaultBody = &clause.Body
+			continue
+		}
+		body := b.newBlock("select.body")
+		next := b.newBlock("select.next")
+		b.ifelse(body, next)
+		b.current = body
+		b.targets = &targets{
+			tail:   b.targets,
+			_break: done,
+		}
+		switch comm := clause.Comm.(type) {
+		case *ast.ExprStmt: // <-ch
+			// nop
+		case *ast.AssignStmt: // x := <-states[state].Chan
+			b.add(comm.Lhs[0])
+		}
+		b.stmtList(clause.Body)
+		b.targets = b.targets.tail
+		b.jump(done)
+		b.current = next
+	}
+	if defaultBody != nil {
+		b.targets = &targets{
+			tail:   b.targets,
+			_break: done,
+		}
+		b.stmtList(*defaultBody)
+		b.targets = b.targets.tail
+		b.jump(done)
+	}
+	b.current = done
+}
+
+func (b *builder) forStmt(s *ast.ForStmt, label *lblock) {
+	//	...init...
+	//      jump loop
+	// loop:
+	//      if cond goto body else done
+	// body:
+	//      ...body...
+	//      jump post
+	// post:				 (target of continue)
+	//      ...post...
+	//      jump loop
+	// done:                                 (target of break)
+	if s.Init != nil {
+		b.stmt(s.Init)
+	}
+	body := b.newBlock("for.body")
+	done := b.newBlock("for.done") // target of 'break'
+	loop := body                   // target of back-edge
+	if s.Cond != nil {
+		loop = b.newBlock("for.loop")
+	}
+	cont := loop // target of 'continue'
+	if s.Post != nil {
+		cont = b.newBlock("for.post")
+	}
+	if label != nil {
+		label._break = done
+		label._continue = cont
+	}
+	b.jump(loop)
+	b.current = loop
+	if loop != body {
+		b.add(s.Cond)
+		b.ifelse(body, done)
+		b.current = body
+	}
+	b.targets = &targets{
+		tail:      b.targets,
+		_break:    done,
+		_continue: cont,
+	}
+	b.stmt(s.Body)
+	b.targets = b.targets.tail
+	b.jump(cont)
+
+	if s.Post != nil {
+		b.current = cont
+		b.stmt(s.Post)
+		b.jump(loop) // back-edge
+	}
+	b.current = done
+}
+
+func (b *builder) rangeStmt(s *ast.RangeStmt, label *lblock) {
+	b.add(s.X)
+
+	if s.Key != nil {
+		b.add(s.Key)
+	}
+	if s.Value != nil {
+		b.add(s.Value)
+	}
+
+	//      ...
+	// loop:                                   (target of continue)
+	// 	if ... goto body else done
+	// body:
+	//      ...
+	// 	jump loop
+	// done:                                   (target of break)
+
+	loop := b.newBlock("range.loop")
+	b.jump(loop)
+	b.current = loop
+
+	body := b.newBlock("range.body")
+	done := b.newBlock("range.done")
+	b.ifelse(body, done)
+	b.current = body
+
+	if label != nil {
+		label._break = done
+		label._continue = loop
+	}
+	b.targets = &targets{
+		tail:      b.targets,
+		_break:    done,
+		_continue: loop,
+	}
+	b.stmt(s.Body)
+	b.targets = b.targets.tail
+	b.jump(loop) // back-edge
+	b.current = done
+}
+
+// -------- helpers --------
+
+// Destinations associated with unlabeled for/switch/select stmts.
+// We push/pop one of these as we enter/leave each construct and for
+// each BranchStmt we scan for the innermost target of the right type.
+//
+type targets struct {
+	tail         *targets // rest of stack
+	_break       *Block
+	_continue    *Block
+	_fallthrough *Block
+}
+
+// Destinations associated with a labeled block.
+// We populate these as labels are encountered in forward gotos or
+// labeled statements.
+//
+type lblock struct {
+	_goto     *Block
+	_break    *Block
+	_continue *Block
+}
+
+// labeledBlock returns the branch target associated with the
+// specified label, creating it if needed.
+//
+func (b *builder) labeledBlock(label *ast.Ident) *lblock {
+	lb := b.lblocks[label.Obj]
+	if lb == nil {
+		lb = &lblock{_goto: b.newBlock(label.Name)}
+		if b.lblocks == nil {
+			b.lblocks = make(map[*ast.Object]*lblock)
+		}
+		b.lblocks[label.Obj] = lb
+	}
+	return lb
+}
+
+// newBlock appends a new unconnected basic block to b.cfg's block
+// slice and returns it.
+// It does not automatically become the current block.
+// comment is an optional string for more readable debugging output.
+func (b *builder) newBlock(comment string) *Block {
+	g := b.cfg
+	block := &Block{
+		index:   int32(len(g.Blocks)),
+		comment: comment,
+	}
+	block.Succs = block.succs2[:0]
+	g.Blocks = append(g.Blocks, block)
+	return block
+}
+
+func (b *builder) newUnreachableBlock(comment string) *Block {
+	block := b.newBlock(comment)
+	block.unreachable = true
+	return block
+}
+
+func (b *builder) add(n ast.Node) {
+	b.current.Nodes = append(b.current.Nodes, n)
+}
+
+// jump adds an edge from the current block to the target block,
+// and sets b.current to nil.
+func (b *builder) jump(target *Block) {
+	b.current.Succs = append(b.current.Succs, target)
+	b.current = nil
+}
+
+// ifelse emits edges from the current block to the t and f blocks,
+// and sets b.current to nil.
+func (b *builder) ifelse(t, f *Block) {
+	b.current.Succs = append(b.current.Succs, t, f)
+	b.current = nil
+}

tools/vendor/github.com/dnephin/govet/internal/cfg/cfg.go

@@ -0,0 +1,142 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This package constructs a simple control-flow graph (CFG) of the
+// statements and expressions within a single function.
+//
+// Use cfg.New to construct the CFG for a function body.
+//
+// The blocks of the CFG contain all the function's non-control
+// statements.  The CFG does not contain control statements such as If,
+// Switch, Select, and Branch, but does contain their subexpressions.
+// For example, this source code:
+//
+//	if x := f(); x != nil {
+//		T()
+//	} else {
+//		F()
+//	}
+//
+// produces this CFG:
+//
+//    1:  x := f()
+//        x != nil
+//        succs: 2, 3
+//    2:  T()
+//        succs: 4
+//    3:  F()
+//        succs: 4
+//    4:
+//
+// The CFG does contain Return statements; even implicit returns are
+// materialized (at the position of the function's closing brace).
+//
+// The CFG does not record conditions associated with conditional branch
+// edges, nor the short-circuit semantics of the && and || operators,
+// nor abnormal control flow caused by panic.  If you need this
+// information, use golang.org/x/tools/go/ssa instead.
+//
+package cfg
+
+// Although the vet tool has type information, it is often extremely
+// fragmentary, so for simplicity this package does not depend on
+// go/types.  Consequently control-flow conditions are ignored even
+// when constant, and "mayReturn" information must be provided by the
+// client.
+import (
+	"bytes"
+	"fmt"
+	"go/ast"
+	"go/format"
+	"go/token"
+)
+
+// A CFG represents the control-flow graph of a single function.
+//
+// The entry point is Blocks[0]; there may be multiple return blocks.
+type CFG struct {
+	Blocks []*Block // block[0] is entry; order otherwise undefined
+}
+
+// A Block represents a basic block: a list of statements and
+// expressions that are always evaluated sequentially.
+//
+// A block may have 0-2 successors: zero for a return block or a block
+// that calls a function such as panic that never returns; one for a
+// normal (jump) block; and two for a conditional (if) block.
+type Block struct {
+	Nodes []ast.Node // statements, expressions, and ValueSpecs
+	Succs []*Block   // successor nodes in the graph
+
+	comment     string    // for debugging
+	index       int32     // index within CFG.Blocks
+	unreachable bool      // is block of stmts following return/panic/for{}
+	succs2      [2]*Block // underlying array for Succs
+}
+
+// New returns a new control-flow graph for the specified function body,
+// which must be non-nil.
+//
+// The CFG builder calls mayReturn to determine whether a given function
+// call may return.  For example, calls to panic, os.Exit, and log.Fatal
+// do not return, so the builder can remove infeasible graph edges
+// following such calls.  The builder calls mayReturn only for a
+// CallExpr beneath an ExprStmt.
+func New(body *ast.BlockStmt, mayReturn func(*ast.CallExpr) bool) *CFG {
+	b := builder{
+		mayReturn: mayReturn,
+		cfg:       new(CFG),
+	}
+	b.current = b.newBlock("entry")
+	b.stmt(body)
+
+	// Does control fall off the end of the function's body?
+	// Make implicit return explicit.
+	if b.current != nil && !b.current.unreachable {
+		b.add(&ast.ReturnStmt{
+			Return: body.End() - 1,
+		})
+	}
+
+	return b.cfg
+}
+
+func (b *Block) String() string {
+	return fmt.Sprintf("block %d (%s)", b.index, b.comment)
+}
+
+// Return returns the return statement at the end of this block if present, nil otherwise.
+func (b *Block) Return() (ret *ast.ReturnStmt) {
+	if len(b.Nodes) > 0 {
+		ret, _ = b.Nodes[len(b.Nodes)-1].(*ast.ReturnStmt)
+	}
+	return
+}
+
+// Format formats the control-flow graph for ease of debugging.
+func (g *CFG) Format(fset *token.FileSet) string {
+	var buf bytes.Buffer
+	for _, b := range g.Blocks {
+		fmt.Fprintf(&buf, ".%d: # %s\n", b.index, b.comment)
+		for _, n := range b.Nodes {
+			fmt.Fprintf(&buf, "\t%s\n", formatNode(fset, n))
+		}
+		if len(b.Succs) > 0 {
+			fmt.Fprintf(&buf, "\tsuccs:")
+			for _, succ := range b.Succs {
+				fmt.Fprintf(&buf, " %d", succ.index)
+			}
+			buf.WriteByte('\n')
+		}
+		buf.WriteByte('\n')
+	}
+	return buf.String()
+}
+
+func formatNode(fset *token.FileSet, n ast.Node) string {
+	var buf bytes.Buffer
+	format.Node(&buf, fset, n)
+	// Indent secondary lines by a tab.
+	return string(bytes.Replace(buf.Bytes(), []byte("\n"), []byte("\n\t"), -1))
+}

tools/vendor/github.com/dnephin/govet/internal/whitelist/whitelist.go

@@ -0,0 +1,28 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package whitelist defines exceptions for the vet tool.
+package whitelist
+
+// UnkeyedLiteral is a white list of types in the standard packages
+// that are used with unkeyed literals we deem to be acceptable.
+var UnkeyedLiteral = map[string]bool{
+	// These image and image/color struct types are frozen. We will never add fields to them.
+	"image/color.Alpha16": true,
+	"image/color.Alpha":   true,
+	"image/color.CMYK":    true,
+	"image/color.Gray16":  true,
+	"image/color.Gray":    true,
+	"image/color.NRGBA64": true,
+	"image/color.NRGBA":   true,
+	"image/color.NYCbCrA": true,
+	"image/color.RGBA64":  true,
+	"image/color.RGBA":    true,
+	"image/color.YCbCr":   true,
+	"image.Point":         true,
+	"image.Rectangle":     true,
+	"image.Uniform":       true,
+
+	"unicode.Range16": true,
+}

tools/vendor/github.com/dnephin/govet/lostcancel.go

@@ -0,0 +1,318 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"github.com/dnephin/govet/internal/cfg"
+	"fmt"
+	"go/ast"
+	"go/types"
+	"strconv"
+)
+
+func init() {
+	register("lostcancel",
+		"check for failure to call cancelation function returned by context.WithCancel",
+		checkLostCancel,
+		funcDecl, funcLit)
+}
+
+const debugLostCancel = false
+
+var contextPackage = "context"
+
+// checkLostCancel reports a failure to the call the cancel function
+// returned by context.WithCancel, either because the variable was
+// assigned to the blank identifier, or because there exists a
+// control-flow path from the call to a return statement and that path
+// does not "use" the cancel function.  Any reference to the variable
+// counts as a use, even within a nested function literal.
+//
+// checkLostCancel analyzes a single named or literal function.
+func checkLostCancel(f *File, node ast.Node) {
+	// Fast path: bypass check if file doesn't use context.WithCancel.
+	if !hasImport(f.file, contextPackage) {
+		return
+	}
+
+	// Maps each cancel variable to its defining ValueSpec/AssignStmt.
+	cancelvars := make(map[*types.Var]ast.Node)
+
+	// Find the set of cancel vars to analyze.
+	stack := make([]ast.Node, 0, 32)
+	ast.Inspect(node, func(n ast.Node) bool {
+		switch n.(type) {
+		case *ast.FuncLit:
+			if len(stack) > 0 {
+				return false // don't stray into nested functions
+			}
+		case nil:
+			stack = stack[:len(stack)-1] // pop
+			return true
+		}
+		stack = append(stack, n) // push
+
+		// Look for [{AssignStmt,ValueSpec} CallExpr SelectorExpr]:
+		//
+		//   ctx, cancel    := context.WithCancel(...)
+		//   ctx, cancel     = context.WithCancel(...)
+		//   var ctx, cancel = context.WithCancel(...)
+		//
+		if isContextWithCancel(f, n) && isCall(stack[len(stack)-2]) {
+			var id *ast.Ident // id of cancel var
+			stmt := stack[len(stack)-3]
+			switch stmt := stmt.(type) {
+			case *ast.ValueSpec:
+				if len(stmt.Names) > 1 {
+					id = stmt.Names[1]
+				}
+			case *ast.AssignStmt:
+				if len(stmt.Lhs) > 1 {
+					id, _ = stmt.Lhs[1].(*ast.Ident)
+				}
+			}
+			if id != nil {
+				if id.Name == "_" {
+					f.Badf(id.Pos(), "the cancel function returned by context.%s should be called, not discarded, to avoid a context leak",
+						n.(*ast.SelectorExpr).Sel.Name)
+				} else if v, ok := f.pkg.uses[id].(*types.Var); ok {
+					cancelvars[v] = stmt
+				} else if v, ok := f.pkg.defs[id].(*types.Var); ok {
+					cancelvars[v] = stmt
+				}
+			}
+		}
+
+		return true
+	})
+
+	if len(cancelvars) == 0 {
+		return // no need to build CFG
+	}
+
+	// Tell the CFG builder which functions never return.
+	info := &types.Info{Uses: f.pkg.uses, Selections: f.pkg.selectors}
+	mayReturn := func(call *ast.CallExpr) bool {
+		name := callName(info, call)
+		return !noReturnFuncs[name]
+	}
+
+	// Build the CFG.
+	var g *cfg.CFG
+	var sig *types.Signature
+	switch node := node.(type) {
+	case *ast.FuncDecl:
+		sig, _ = f.pkg.defs[node.Name].Type().(*types.Signature)
+		g = cfg.New(node.Body, mayReturn)
+	case *ast.FuncLit:
+		sig, _ = f.pkg.types[node.Type].Type.(*types.Signature)
+		g = cfg.New(node.Body, mayReturn)
+	}
+
+	// Print CFG.
+	if debugLostCancel {
+		fmt.Println(g.Format(f.fset))
+	}
+
+	// Examine the CFG for each variable in turn.
+	// (It would be more efficient to analyze all cancelvars in a
+	// single pass over the AST, but seldom is there more than one.)
+	for v, stmt := range cancelvars {
+		if ret := lostCancelPath(f, g, v, stmt, sig); ret != nil {
+			lineno := f.fset.Position(stmt.Pos()).Line
+			f.Badf(stmt.Pos(), "the %s function is not used on all paths (possible context leak)", v.Name())
+			f.Badf(ret.Pos(), "this return statement may be reached without using the %s var defined on line %d", v.Name(), lineno)
+		}
+	}
+}
+
+func isCall(n ast.Node) bool { _, ok := n.(*ast.CallExpr); return ok }
+
+func hasImport(f *ast.File, path string) bool {
+	for _, imp := range f.Imports {
+		v, _ := strconv.Unquote(imp.Path.Value)
+		if v == path {
+			return true
+		}
+	}
+	return false
+}
+
+// isContextWithCancel reports whether n is one of the qualified identifiers
+// context.With{Cancel,Timeout,Deadline}.
+func isContextWithCancel(f *File, n ast.Node) bool {
+	if sel, ok := n.(*ast.SelectorExpr); ok {
+		switch sel.Sel.Name {
+		case "WithCancel", "WithTimeout", "WithDeadline":
+			if x, ok := sel.X.(*ast.Ident); ok {
+				if pkgname, ok := f.pkg.uses[x].(*types.PkgName); ok {
+					return pkgname.Imported().Path() == contextPackage
+				}
+				// Import failed, so we can't check package path.
+				// Just check the local package name (heuristic).
+				return x.Name == "context"
+			}
+		}
+	}
+	return false
+}
+
+// lostCancelPath finds a path through the CFG, from stmt (which defines
+// the 'cancel' variable v) to a return statement, that doesn't "use" v.
+// If it finds one, it returns the return statement (which may be synthetic).
+// sig is the function's type, if known.
+func lostCancelPath(f *File, g *cfg.CFG, v *types.Var, stmt ast.Node, sig *types.Signature) *ast.ReturnStmt {
+	vIsNamedResult := sig != nil && tupleContains(sig.Results(), v)
+
+	// uses reports whether stmts contain a "use" of variable v.
+	uses := func(f *File, v *types.Var, stmts []ast.Node) bool {
+		found := false
+		for _, stmt := range stmts {
+			ast.Inspect(stmt, func(n ast.Node) bool {
+				switch n := n.(type) {
+				case *ast.Ident:
+					if f.pkg.uses[n] == v {
+						found = true
+					}
+				case *ast.ReturnStmt:
+					// A naked return statement counts as a use
+					// of the named result variables.
+					if n.Results == nil && vIsNamedResult {
+						found = true
+					}
+				}
+				return !found
+			})
+		}
+		return found
+	}
+
+	// blockUses computes "uses" for each block, caching the result.
+	memo := make(map[*cfg.Block]bool)
+	blockUses := func(f *File, v *types.Var, b *cfg.Block) bool {
+		res, ok := memo[b]
+		if !ok {
+			res = uses(f, v, b.Nodes)
+			memo[b] = res
+		}
+		return res
+	}
+
+	// Find the var's defining block in the CFG,
+	// plus the rest of the statements of that block.
+	var defblock *cfg.Block
+	var rest []ast.Node
+outer:
+	for _, b := range g.Blocks {
+		for i, n := range b.Nodes {
+			if n == stmt {
+				defblock = b
+				rest = b.Nodes[i+1:]
+				break outer
+			}
+		}
+	}
+	if defblock == nil {
+		panic("internal error: can't find defining block for cancel var")
+	}
+
+	// Is v "used" in the remainder of its defining block?
+	if uses(f, v, rest) {
+		return nil
+	}
+
+	// Does the defining block return without using v?
+	if ret := defblock.Return(); ret != nil {
+		return ret
+	}
+
+	// Search the CFG depth-first for a path, from defblock to a
+	// return block, in which v is never "used".
+	seen := make(map[*cfg.Block]bool)
+	var search func(blocks []*cfg.Block) *ast.ReturnStmt
+	search = func(blocks []*cfg.Block) *ast.ReturnStmt {
+		for _, b := range blocks {
+			if !seen[b] {
+				seen[b] = true
+
+				// Prune the search if the block uses v.
+				if blockUses(f, v, b) {
+					continue
+				}
+
+				// Found path to return statement?
+				if ret := b.Return(); ret != nil {
+					if debugLostCancel {
+						fmt.Printf("found path to return in block %s\n", b)
+					}
+					return ret // found
+				}
+
+				// Recur
+				if ret := search(b.Succs); ret != nil {
+					if debugLostCancel {
+						fmt.Printf(" from block %s\n", b)
+					}
+					return ret
+				}
+			}
+		}
+		return nil
+	}
+	return search(defblock.Succs)
+}
+
+func tupleContains(tuple *types.Tuple, v *types.Var) bool {
+	for i := 0; i < tuple.Len(); i++ {
+		if tuple.At(i) == v {
+			return true
+		}
+	}
+	return false
+}
+
+var noReturnFuncs = map[string]bool{
+	"(*testing.common).FailNow": true,
+	"(*testing.common).Fatal":   true,
+	"(*testing.common).Fatalf":  true,
+	"(*testing.common).Skip":    true,
+	"(*testing.common).SkipNow": true,
+	"(*testing.common).Skipf":   true,
+	"log.Fatal":                 true,
+	"log.Fatalf":                true,
+	"log.Fatalln":               true,
+	"os.Exit":                   true,
+	"panic":                     true,
+	"runtime.Goexit":            true,
+}
+
+// callName returns the canonical name of the builtin, method, or
+// function called by call, if known.
+func callName(info *types.Info, call *ast.CallExpr) string {
+	switch fun := call.Fun.(type) {
+	case *ast.Ident:
+		// builtin, e.g. "panic"
+		if obj, ok := info.Uses[fun].(*types.Builtin); ok {
+			return obj.Name()
+		}
+	case *ast.SelectorExpr:
+		if sel, ok := info.Selections[fun]; ok && sel.Kind() == types.MethodVal {
+			// method call, e.g. "(*testing.common).Fatal"
+			meth := sel.Obj()
+			return fmt.Sprintf("(%s).%s",
+				meth.Type().(*types.Signature).Recv().Type(),
+				meth.Name())
+		}
+		if obj, ok := info.Uses[fun.Sel]; ok {
+			// qualified identifier, e.g. "os.Exit"
+			return fmt.Sprintf("%s.%s",
+				obj.Pkg().Path(),
+				obj.Name())
+		}
+	}
+
+	// function with no name, or defined in missing imported package
+	return ""
+}

tools/vendor/github.com/dnephin/govet/main.go

@@ -0,0 +1,504 @@
+// Copyright 2010 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Vet is a simple checker for static errors in Go source code.
+// See doc.go for more information.
+package main
+
+import (
+	"bytes"
+	"flag"
+	"fmt"
+	"go/ast"
+	"go/build"
+	"go/parser"
+	"go/printer"
+	"go/token"
+	"go/types"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+)
+
+var (
+	verbose = flag.Bool("v", false, "verbose")
+	tags    = flag.String("tags", "", "comma-separated list of build tags to apply when parsing")
+	noRecurse = flag.Bool("no-recurse", false, "disable recursive directory walking")
+	tagList = []string{} // exploded version of tags flag; set in main
+)
+
+var exitCode = 0
+
+// "-all" flag enables all non-experimental checks
+var all = triStateFlag("all", unset, "enable all non-experimental checks")
+
+// Flags to control which individual checks to perform.
+var report = map[string]*triState{
+	// Only unusual checks are written here.
+	// Most checks that operate during the AST walk are added by register.
+	"asmdecl":   triStateFlag("asmdecl", unset, "check assembly against Go declarations"),
+	"buildtags": triStateFlag("buildtags", unset, "check that +build tags are valid"),
+}
+
+// experimental records the flags enabling experimental features. These must be
+// requested explicitly; they are not enabled by -all.
+var experimental = map[string]bool{}
+
+// setTrueCount record how many flags are explicitly set to true.
+var setTrueCount int
+
+// dirsRun and filesRun indicate whether the vet is applied to directory or
+// file targets. The distinction affects which checks are run.
+var dirsRun, filesRun bool
+
+// includesNonTest indicates whether the vet is applied to non-test targets.
+// Certain checks are relevant only if they touch both test and non-test files.
+var includesNonTest bool
+
+// A triState is a boolean that knows whether it has been set to either true or false.
+// It is used to identify if a flag appears; the standard boolean flag cannot
+// distinguish missing from unset. It also satisfies flag.Value.
+type triState int
+
+const (
+	unset triState = iota
+	setTrue
+	setFalse
+)
+
+func triStateFlag(name string, value triState, usage string) *triState {
+	flag.Var(&value, name, usage)
+	return &value
+}
+
+// triState implements flag.Value, flag.Getter, and flag.boolFlag.
+// They work like boolean flags: we can say vet -printf as well as vet -printf=true
+func (ts *triState) Get() interface{} {
+	return *ts == setTrue
+}
+
+func (ts triState) isTrue() bool {
+	return ts == setTrue
+}
+
+func (ts *triState) Set(value string) error {
+	b, err := strconv.ParseBool(value)
+	if err != nil {
+		return err
+	}
+	if b {
+		*ts = setTrue
+		setTrueCount++
+	} else {
+		*ts = setFalse
+	}
+	return nil
+}
+
+func (ts *triState) String() string {
+	switch *ts {
+	case unset:
+		return "true" // An unset flag will be set by -all, so defaults to true.
+	case setTrue:
+		return "true"
+	case setFalse:
+		return "false"
+	}
+	panic("not reached")
+}
+
+func (ts triState) IsBoolFlag() bool {
+	return true
+}
+
+// vet tells whether to report errors for the named check, a flag name.
+func vet(name string) bool {
+	return report[name].isTrue()
+}
+
+// setExit sets the value for os.Exit when it is called, later. It
+// remembers the highest value.
+func setExit(err int) {
+	if err > exitCode {
+		exitCode = err
+	}
+}
+
+var (
+	// Each of these vars has a corresponding case in (*File).Visit.
+	assignStmt    *ast.AssignStmt
+	binaryExpr    *ast.BinaryExpr
+	callExpr      *ast.CallExpr
+	compositeLit  *ast.CompositeLit
+	exprStmt      *ast.ExprStmt
+	field         *ast.Field
+	funcDecl      *ast.FuncDecl
+	funcLit       *ast.FuncLit
+	genDecl       *ast.GenDecl
+	interfaceType *ast.InterfaceType
+	rangeStmt     *ast.RangeStmt
+	returnStmt    *ast.ReturnStmt
+
+	// checkers is a two-level map.
+	// The outer level is keyed by a nil pointer, one of the AST vars above.
+	// The inner level is keyed by checker name.
+	checkers = make(map[ast.Node]map[string]func(*File, ast.Node))
+)
+
+func register(name, usage string, fn func(*File, ast.Node), types ...ast.Node) {
+	report[name] = triStateFlag(name, unset, usage)
+	for _, typ := range types {
+		m := checkers[typ]
+		if m == nil {
+			m = make(map[string]func(*File, ast.Node))
+			checkers[typ] = m
+		}
+		m[name] = fn
+	}
+}
+
+// Usage is a replacement usage function for the flags package.
+func Usage() {
+	fmt.Fprintf(os.Stderr, "Usage of %s:\n", os.Args[0])
+	fmt.Fprintf(os.Stderr, "\tvet [flags] directory...\n")
+	fmt.Fprintf(os.Stderr, "\tvet [flags] files... # Must be a single package\n")
+	fmt.Fprintf(os.Stderr, "By default, -all is set and all non-experimental checks are run.\n")
+	fmt.Fprintf(os.Stderr, "For more information run\n")
+	fmt.Fprintf(os.Stderr, "\tgo doc cmd/vet\n\n")
+	fmt.Fprintf(os.Stderr, "Flags:\n")
+	flag.PrintDefaults()
+	os.Exit(2)
+}
+
+// File is a wrapper for the state of a file used in the parser.
+// The parse tree walkers are all methods of this type.
+type File struct {
+	pkg     *Package
+	fset    *token.FileSet
+	name    string
+	content []byte
+	file    *ast.File
+	b       bytes.Buffer // for use by methods
+
+	// Parsed package "foo" when checking package "foo_test"
+	basePkg *Package
+
+	// The objects that are receivers of a "String() string" method.
+	// This is used by the recursiveStringer method in print.go.
+	stringers map[*ast.Object]bool
+
+	// Registered checkers to run.
+	checkers map[ast.Node][]func(*File, ast.Node)
+}
+
+func main() {
+	flag.Usage = Usage
+	flag.Parse()
+
+	// If any flag is set, we run only those checks requested.
+	// If all flag is set true or if no flags are set true, set all the non-experimental ones
+	// not explicitly set (in effect, set the "-all" flag).
+	if setTrueCount == 0 || *all == setTrue {
+		for name, setting := range report {
+			if *setting == unset && !experimental[name] {
+				*setting = setTrue
+			}
+		}
+	}
+
+	tagList = strings.Split(*tags, ",")
+
+	initPrintFlags()
+	initUnusedFlags()
+
+	if flag.NArg() == 0 {
+		Usage()
+	}
+	for _, name := range flag.Args() {
+		// Is it a directory?
+		fi, err := os.Stat(name)
+		if err != nil {
+			warnf("error walking tree: %s", err)
+			continue
+		}
+		if fi.IsDir() {
+			dirsRun = true
+		} else {
+			filesRun = true
+			if !strings.HasSuffix(name, "_test.go") {
+				includesNonTest = true
+			}
+		}
+	}
+	if dirsRun && filesRun {
+		Usage()
+	}
+	if dirsRun {
+		for _, name := range flag.Args() {
+			if *noRecurse {
+				doPackageDir(name)
+			} else {
+				walkDir(name)
+			}
+		}
+		os.Exit(exitCode)
+	}
+	if doPackage(".", flag.Args(), nil) == nil {
+		warnf("no files checked")
+	}
+	os.Exit(exitCode)
+}
+
+// prefixDirectory places the directory name on the beginning of each name in the list.
+func prefixDirectory(directory string, names []string) {
+	if directory != "." {
+		for i, name := range names {
+			names[i] = filepath.Join(directory, name)
+		}
+	}
+}
+
+// doPackageDir analyzes the single package found in the directory, if there is one,
+// plus a test package, if there is one.
+func doPackageDir(directory string) {
+	context := build.Default
+	if len(context.BuildTags) != 0 {
+		warnf("build tags %s previously set", context.BuildTags)
+	}
+	context.BuildTags = append(tagList, context.BuildTags...)
+
+	pkg, err := context.ImportDir(directory, 0)
+	if err != nil {
+		// If it's just that there are no go source files, that's fine.
+		if _, nogo := err.(*build.NoGoError); nogo {
+			return
+		}
+		// Non-fatal: we are doing a recursive walk and there may be other directories.
+		warnf("cannot process directory %s: %s", directory, err)
+		return
+	}
+	var names []string
+	names = append(names, pkg.GoFiles...)
+	names = append(names, pkg.CgoFiles...)
+	names = append(names, pkg.TestGoFiles...) // These are also in the "foo" package.
+	names = append(names, pkg.SFiles...)
+	prefixDirectory(directory, names)
+	basePkg := doPackage(directory, names, nil)
+	// Is there also a "foo_test" package? If so, do that one as well.
+	if len(pkg.XTestGoFiles) > 0 {
+		names = pkg.XTestGoFiles
+		prefixDirectory(directory, names)
+		doPackage(directory, names, basePkg)
+	}
+}
+
+type Package struct {
+	path      string
+	defs      map[*ast.Ident]types.Object
+	uses      map[*ast.Ident]types.Object
+	selectors map[*ast.SelectorExpr]*types.Selection
+	types     map[ast.Expr]types.TypeAndValue
+	spans     map[types.Object]Span
+	files     []*File
+	typesPkg  *types.Package
+}
+
+// doPackage analyzes the single package constructed from the named files.
+// It returns the parsed Package or nil if none of the files have been checked.
+func doPackage(directory string, names []string, basePkg *Package) *Package {
+	var files []*File
+	var astFiles []*ast.File
+	fs := token.NewFileSet()
+	for _, name := range names {
+		data, err := ioutil.ReadFile(name)
+		if err != nil {
+			// Warn but continue to next package.
+			warnf("%s: %s", name, err)
+			return nil
+		}
+		checkBuildTag(name, data)
+		var parsedFile *ast.File
+		if strings.HasSuffix(name, ".go") {
+			parsedFile, err = parser.ParseFile(fs, name, data, 0)
+			if err != nil {
+				warnf("%s: %s", name, err)
+				return nil
+			}
+			astFiles = append(astFiles, parsedFile)
+		}
+		files = append(files, &File{fset: fs, content: data, name: name, file: parsedFile})
+	}
+	if len(astFiles) == 0 {
+		return nil
+	}
+	pkg := new(Package)
+	pkg.path = astFiles[0].Name.Name
+	pkg.files = files
+	// Type check the package.
+	err := pkg.check(fs, astFiles)
+	if err != nil && *verbose {
+		warnf("%s", err)
+	}
+
+	// Check.
+	chk := make(map[ast.Node][]func(*File, ast.Node))
+	for typ, set := range checkers {
+		for name, fn := range set {
+			if vet(name) {
+				chk[typ] = append(chk[typ], fn)
+			}
+		}
+	}
+	for _, file := range files {
+		file.pkg = pkg
+		file.basePkg = basePkg
+		file.checkers = chk
+		if file.file != nil {
+			file.walkFile(file.name, file.file)
+		}
+	}
+	asmCheck(pkg)
+	return pkg
+}
+
+func visit(path string, f os.FileInfo, err error) error {
+	if err != nil {
+		warnf("walk error: %s", err)
+		return err
+	}
+	// One package per directory. Ignore the files themselves.
+	if !f.IsDir() {
+		return nil
+	}
+	doPackageDir(path)
+	return nil
+}
+
+func (pkg *Package) hasFileWithSuffix(suffix string) bool {
+	for _, f := range pkg.files {
+		if strings.HasSuffix(f.name, suffix) {
+			return true
+		}
+	}
+	return false
+}
+
+// walkDir recursively walks the tree looking for Go packages.
+func walkDir(root string) {
+	filepath.Walk(root, visit)
+}
+
+// errorf formats the error to standard error, adding program
+// identification and a newline, and exits.
+func errorf(format string, args ...interface{}) {
+	fmt.Fprintf(os.Stderr, "vet: "+format+"\n", args...)
+	os.Exit(2)
+}
+
+// warnf formats the error to standard error, adding program
+// identification and a newline, but does not exit.
+func warnf(format string, args ...interface{}) {
+	fmt.Fprintf(os.Stderr, "vet: "+format+"\n", args...)
+	setExit(1)
+}
+
+// Println is fmt.Println guarded by -v.
+func Println(args ...interface{}) {
+	if !*verbose {
+		return
+	}
+	fmt.Println(args...)
+}
+
+// Printf is fmt.Printf guarded by -v.
+func Printf(format string, args ...interface{}) {
+	if !*verbose {
+		return
+	}
+	fmt.Printf(format+"\n", args...)
+}
+
+// Bad reports an error and sets the exit code..
+func (f *File) Bad(pos token.Pos, args ...interface{}) {
+	f.Warn(pos, args...)
+	setExit(1)
+}
+
+// Badf reports a formatted error and sets the exit code.
+func (f *File) Badf(pos token.Pos, format string, args ...interface{}) {
+	f.Warnf(pos, format, args...)
+	setExit(1)
+}
+
+// loc returns a formatted representation of the position.
+func (f *File) loc(pos token.Pos) string {
+	if pos == token.NoPos {
+		return ""
+	}
+	// Do not print columns. Because the pos often points to the start of an
+	// expression instead of the inner part with the actual error, the
+	// precision can mislead.
+	posn := f.fset.Position(pos)
+	return fmt.Sprintf("%s:%d", posn.Filename, posn.Line)
+}
+
+// Warn reports an error but does not set the exit code.
+func (f *File) Warn(pos token.Pos, args ...interface{}) {
+	fmt.Fprintf(os.Stderr, "%s: %s", f.loc(pos), fmt.Sprintln(args...))
+}
+
+// Warnf reports a formatted error but does not set the exit code.
+func (f *File) Warnf(pos token.Pos, format string, args ...interface{}) {
+	fmt.Fprintf(os.Stderr, "%s: %s\n", f.loc(pos), fmt.Sprintf(format, args...))
+}
+
+// walkFile walks the file's tree.
+func (f *File) walkFile(name string, file *ast.File) {
+	Println("Checking file", name)
+	ast.Walk(f, file)
+}
+
+// Visit implements the ast.Visitor interface.
+func (f *File) Visit(node ast.Node) ast.Visitor {
+	var key ast.Node
+	switch node.(type) {
+	case *ast.AssignStmt:
+		key = assignStmt
+	case *ast.BinaryExpr:
+		key = binaryExpr
+	case *ast.CallExpr:
+		key = callExpr
+	case *ast.CompositeLit:
+		key = compositeLit
+	case *ast.ExprStmt:
+		key = exprStmt
+	case *ast.Field:
+		key = field
+	case *ast.FuncDecl:
+		key = funcDecl
+	case *ast.FuncLit:
+		key = funcLit
+	case *ast.GenDecl:
+		key = genDecl
+	case *ast.InterfaceType:
+		key = interfaceType
+	case *ast.RangeStmt:
+		key = rangeStmt
+	case *ast.ReturnStmt:
+		key = returnStmt
+	}
+	for _, fn := range f.checkers[key] {
+		fn(f, node)
+	}
+	return f
+}
+
+// gofmt returns a string representation of the expression.
+func (f *File) gofmt(x ast.Expr) string {
+	f.b.Reset()
+	printer.Fprint(&f.b, f.fset, x)
+	return f.b.String()
+}

tools/vendor/github.com/dnephin/govet/method.go

@@ -0,0 +1,182 @@
+// Copyright 2010 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file contains the code to check canonical methods.
+
+package main
+
+import (
+	"fmt"
+	"go/ast"
+	"go/printer"
+	"strings"
+)
+
+func init() {
+	register("methods",
+		"check that canonically named methods are canonically defined",
+		checkCanonicalMethod,
+		funcDecl, interfaceType)
+}
+
+type MethodSig struct {
+	args    []string
+	results []string
+}
+
+// canonicalMethods lists the input and output types for Go methods
+// that are checked using dynamic interface checks. Because the
+// checks are dynamic, such methods would not cause a compile error
+// if they have the wrong signature: instead the dynamic check would
+// fail, sometimes mysteriously. If a method is found with a name listed
+// here but not the input/output types listed here, vet complains.
+//
+// A few of the canonical methods have very common names.
+// For example, a type might implement a Scan method that
+// has nothing to do with fmt.Scanner, but we still want to check
+// the methods that are intended to implement fmt.Scanner.
+// To do that, the arguments that have a = prefix are treated as
+// signals that the canonical meaning is intended: if a Scan
+// method doesn't have a fmt.ScanState as its first argument,
+// we let it go. But if it does have a fmt.ScanState, then the
+// rest has to match.
+var canonicalMethods = map[string]MethodSig{
+	// "Flush": {{}, {"error"}}, // http.Flusher and jpeg.writer conflict
+	"Format":        {[]string{"=fmt.State", "rune"}, []string{}},                      // fmt.Formatter
+	"GobDecode":     {[]string{"[]byte"}, []string{"error"}},                           // gob.GobDecoder
+	"GobEncode":     {[]string{}, []string{"[]byte", "error"}},                         // gob.GobEncoder
+	"MarshalJSON":   {[]string{}, []string{"[]byte", "error"}},                         // json.Marshaler
+	"MarshalXML":    {[]string{"*xml.Encoder", "xml.StartElement"}, []string{"error"}}, // xml.Marshaler
+	"Peek":          {[]string{"=int"}, []string{"[]byte", "error"}},                   // image.reader (matching bufio.Reader)
+	"ReadByte":      {[]string{}, []string{"byte", "error"}},                           // io.ByteReader
+	"ReadFrom":      {[]string{"=io.Reader"}, []string{"int64", "error"}},              // io.ReaderFrom
+	"ReadRune":      {[]string{}, []string{"rune", "int", "error"}},                    // io.RuneReader
+	"Scan":          {[]string{"=fmt.ScanState", "rune"}, []string{"error"}},           // fmt.Scanner
+	"Seek":          {[]string{"=int64", "int"}, []string{"int64", "error"}},           // io.Seeker
+	"UnmarshalJSON": {[]string{"[]byte"}, []string{"error"}},                           // json.Unmarshaler
+	"UnmarshalXML":  {[]string{"*xml.Decoder", "xml.StartElement"}, []string{"error"}}, // xml.Unmarshaler
+	"UnreadByte":    {[]string{}, []string{"error"}},
+	"UnreadRune":    {[]string{}, []string{"error"}},
+	"WriteByte":     {[]string{"byte"}, []string{"error"}},                // jpeg.writer (matching bufio.Writer)
+	"WriteTo":       {[]string{"=io.Writer"}, []string{"int64", "error"}}, // io.WriterTo
+}
+
+func checkCanonicalMethod(f *File, node ast.Node) {
+	switch n := node.(type) {
+	case *ast.FuncDecl:
+		if n.Recv != nil {
+			canonicalMethod(f, n.Name, n.Type)
+		}
+	case *ast.InterfaceType:
+		for _, field := range n.Methods.List {
+			for _, id := range field.Names {
+				canonicalMethod(f, id, field.Type.(*ast.FuncType))
+			}
+		}
+	}
+}
+
+func canonicalMethod(f *File, id *ast.Ident, t *ast.FuncType) {
+	// Expected input/output.
+	expect, ok := canonicalMethods[id.Name]
+	if !ok {
+		return
+	}
+
+	// Actual input/output
+	args := typeFlatten(t.Params.List)
+	var results []ast.Expr
+	if t.Results != nil {
+		results = typeFlatten(t.Results.List)
+	}
+
+	// Do the =s (if any) all match?
+	if !f.matchParams(expect.args, args, "=") || !f.matchParams(expect.results, results, "=") {
+		return
+	}
+
+	// Everything must match.
+	if !f.matchParams(expect.args, args, "") || !f.matchParams(expect.results, results, "") {
+		expectFmt := id.Name + "(" + argjoin(expect.args) + ")"
+		if len(expect.results) == 1 {
+			expectFmt += " " + argjoin(expect.results)
+		} else if len(expect.results) > 1 {
+			expectFmt += " (" + argjoin(expect.results) + ")"
+		}
+
+		f.b.Reset()
+		if err := printer.Fprint(&f.b, f.fset, t); err != nil {
+			fmt.Fprintf(&f.b, "<%s>", err)
+		}
+		actual := f.b.String()
+		actual = strings.TrimPrefix(actual, "func")
+		actual = id.Name + actual
+
+		f.Badf(id.Pos(), "method %s should have signature %s", actual, expectFmt)
+	}
+}
+
+func argjoin(x []string) string {
+	y := make([]string, len(x))
+	for i, s := range x {
+		if s[0] == '=' {
+			s = s[1:]
+		}
+		y[i] = s
+	}
+	return strings.Join(y, ", ")
+}
+
+// Turn parameter list into slice of types
+// (in the ast, types are Exprs).
+// Have to handle f(int, bool) and f(x, y, z int)
+// so not a simple 1-to-1 conversion.
+func typeFlatten(l []*ast.Field) []ast.Expr {
+	var t []ast.Expr
+	for _, f := range l {
+		if len(f.Names) == 0 {
+			t = append(t, f.Type)
+			continue
+		}
+		for _ = range f.Names {
+			t = append(t, f.Type)
+		}
+	}
+	return t
+}
+
+// Does each type in expect with the given prefix match the corresponding type in actual?
+func (f *File) matchParams(expect []string, actual []ast.Expr, prefix string) bool {
+	for i, x := range expect {
+		if !strings.HasPrefix(x, prefix) {
+			continue
+		}
+		if i >= len(actual) {
+			return false
+		}
+		if !f.matchParamType(x, actual[i]) {
+			return false
+		}
+	}
+	if prefix == "" && len(actual) > len(expect) {
+		return false
+	}
+	return true
+}
+
+// Does this one type match?
+func (f *File) matchParamType(expect string, actual ast.Expr) bool {
+	if strings.HasPrefix(expect, "=") {
+		expect = expect[1:]
+	}
+	// Strip package name if we're in that package.
+	if n := len(f.file.Name.Name); len(expect) > n && expect[:n] == f.file.Name.Name && expect[n] == '.' {
+		expect = expect[n+1:]
+	}
+
+	// Overkill but easy.
+	f.b.Reset()
+	printer.Fprint(&f.b, f.fset, actual)
+	return f.b.String() == expect
+}

tools/vendor/github.com/dnephin/govet/nilfunc.go

@@ -0,0 +1,67 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+/*
+This file contains the code to check for useless function comparisons.
+A useless comparison is one like f == nil as opposed to f() == nil.
+*/
+
+package main
+
+import (
+	"go/ast"
+	"go/token"
+	"go/types"
+)
+
+func init() {
+	register("nilfunc",
+		"check for comparisons between functions and nil",
+		checkNilFuncComparison,
+		binaryExpr)
+}
+
+func checkNilFuncComparison(f *File, node ast.Node) {
+	e := node.(*ast.BinaryExpr)
+
+	// Only want == or != comparisons.
+	if e.Op != token.EQL && e.Op != token.NEQ {
+		return
+	}
+
+	// Only want comparisons with a nil identifier on one side.
+	var e2 ast.Expr
+	switch {
+	case f.isNil(e.X):
+		e2 = e.Y
+	case f.isNil(e.Y):
+		e2 = e.X
+	default:
+		return
+	}
+
+	// Only want identifiers or selector expressions.
+	var obj types.Object
+	switch v := e2.(type) {
+	case *ast.Ident:
+		obj = f.pkg.uses[v]
+	case *ast.SelectorExpr:
+		obj = f.pkg.uses[v.Sel]
+	default:
+		return
+	}
+
+	// Only want functions.
+	if _, ok := obj.(*types.Func); !ok {
+		return
+	}
+
+	f.Badf(e.Pos(), "comparison of function %v %v nil is always %v", obj.Name(), e.Op, e.Op == token.NEQ)
+}
+
+// isNil reports whether the provided expression is the built-in nil
+// identifier.
+func (f *File) isNil(e ast.Expr) bool {
+	return f.pkg.types[e].Type == types.Typ[types.UntypedNil]
+}

tools/vendor/github.com/dnephin/govet/print.go

@@ -0,0 +1,650 @@
+// Copyright 2010 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file contains the printf-checker.
+
+package main
+
+import (
+	"bytes"
+	"flag"
+	"go/ast"
+	"go/constant"
+	"go/token"
+	"go/types"
+	"strconv"
+	"strings"
+	"unicode/utf8"
+)
+
+var printfuncs = flag.String("printfuncs", "", "comma-separated list of print function names to check")
+
+func init() {
+	register("printf",
+		"check printf-like invocations",
+		checkFmtPrintfCall,
+		funcDecl, callExpr)
+}
+
+func initPrintFlags() {
+	if *printfuncs == "" {
+		return
+	}
+	for _, name := range strings.Split(*printfuncs, ",") {
+		if len(name) == 0 {
+			flag.Usage()
+		}
+
+		// Backwards compatibility: skip optional first argument
+		// index after the colon.
+		if colon := strings.LastIndex(name, ":"); colon > 0 {
+			name = name[:colon]
+		}
+
+		name = strings.ToLower(name)
+		if name[len(name)-1] == 'f' {
+			isFormattedPrint[name] = true
+		} else {
+			isPrint[name] = true
+		}
+	}
+}
+
+// isFormattedPrint records the formatted-print functions. Names are
+// lower-cased so the lookup is case insensitive.
+var isFormattedPrint = map[string]bool{
+	"errorf":  true,
+	"fatalf":  true,
+	"fprintf": true,
+	"logf":    true,
+	"panicf":  true,
+	"printf":  true,
+	"sprintf": true,
+}
+
+// isPrint records the unformatted-print functions. Names are lower-cased
+// so the lookup is case insensitive.
+var isPrint = map[string]bool{
+	"error":    true,
+	"fatal":    true,
+	"fprint":   true,
+	"fprintln": true,
+	"log":      true,
+	"panic":    true,
+	"panicln":  true,
+	"print":    true,
+	"println":  true,
+	"sprint":   true,
+	"sprintln": true,
+}
+
+// formatString returns the format string argument and its index within
+// the given printf-like call expression.
+//
+// The last parameter before variadic arguments is assumed to be
+// a format string.
+//
+// The first string literal or string constant is assumed to be a format string
+// if the call's signature cannot be determined.
+//
+// If it cannot find any format string parameter, it returns  ("", -1).
+func formatString(f *File, call *ast.CallExpr) (string, int) {
+	typ := f.pkg.types[call.Fun].Type
+	if typ != nil {
+		if sig, ok := typ.(*types.Signature); ok {
+			if !sig.Variadic() {
+				// Skip checking non-variadic functions
+				return "", -1
+			}
+			idx := sig.Params().Len() - 2
+			if idx < 0 {
+				// Skip checking variadic functions without
+				// fixed arguments.
+				return "", -1
+			}
+			s, ok := stringLiteralArg(f, call, idx)
+			if !ok {
+				// The last argument before variadic args isn't a string
+				return "", -1
+			}
+			return s, idx
+		}
+	}
+
+	// Cannot determine call's signature. Fallback to scanning for the first
+	// string argument in the call
+	for idx := range call.Args {
+		if s, ok := stringLiteralArg(f, call, idx); ok {
+			return s, idx
+		}
+	}
+	return "", -1
+}
+
+// stringLiteralArg returns call's string constant argument at the index idx.
+//
+// ("", false) is returned if call's argument at the index idx isn't a string
+// literal.
+func stringLiteralArg(f *File, call *ast.CallExpr, idx int) (string, bool) {
+	if idx >= len(call.Args) {
+		return "", false
+	}
+	arg := call.Args[idx]
+	lit := f.pkg.types[arg].Value
+	if lit != nil && lit.Kind() == constant.String {
+		return constant.StringVal(lit), true
+	}
+	return "", false
+}
+
+// checkCall triggers the print-specific checks if the call invokes a print function.
+func checkFmtPrintfCall(f *File, node ast.Node) {
+	if d, ok := node.(*ast.FuncDecl); ok && isStringer(f, d) {
+		// Remember we saw this.
+		if f.stringers == nil {
+			f.stringers = make(map[*ast.Object]bool)
+		}
+		if l := d.Recv.List; len(l) == 1 {
+			if n := l[0].Names; len(n) == 1 {
+				f.stringers[n[0].Obj] = true
+			}
+		}
+		return
+	}
+
+	call, ok := node.(*ast.CallExpr)
+	if !ok {
+		return
+	}
+	var Name string
+	switch x := call.Fun.(type) {
+	case *ast.Ident:
+		Name = x.Name
+	case *ast.SelectorExpr:
+		Name = x.Sel.Name
+	default:
+		return
+	}
+
+	name := strings.ToLower(Name)
+	if _, ok := isFormattedPrint[name]; ok {
+		f.checkPrintf(call, Name)
+		return
+	}
+	if _, ok := isPrint[name]; ok {
+		f.checkPrint(call, Name)
+		return
+	}
+}
+
+// isStringer returns true if the provided declaration is a "String() string"
+// method, an implementation of fmt.Stringer.
+func isStringer(f *File, d *ast.FuncDecl) bool {
+	return d.Recv != nil && d.Name.Name == "String" && d.Type.Results != nil &&
+		len(d.Type.Params.List) == 0 && len(d.Type.Results.List) == 1 &&
+		f.pkg.types[d.Type.Results.List[0].Type].Type == types.Typ[types.String]
+}
+
+// formatState holds the parsed representation of a printf directive such as "%3.*[4]d".
+// It is constructed by parsePrintfVerb.
+type formatState struct {
+	verb     rune   // the format verb: 'd' for "%d"
+	format   string // the full format directive from % through verb, "%.3d".
+	name     string // Printf, Sprintf etc.
+	flags    []byte // the list of # + etc.
+	argNums  []int  // the successive argument numbers that are consumed, adjusted to refer to actual arg in call
+	indexed  bool   // whether an indexing expression appears: %[1]d.
+	firstArg int    // Index of first argument after the format in the Printf call.
+	// Used only during parse.
+	file         *File
+	call         *ast.CallExpr
+	argNum       int  // Which argument we're expecting to format now.
+	indexPending bool // Whether we have an indexed argument that has not resolved.
+	nbytes       int  // number of bytes of the format string consumed.
+}
+
+// checkPrintf checks a call to a formatted print routine such as Printf.
+func (f *File) checkPrintf(call *ast.CallExpr, name string) {
+	format, idx := formatString(f, call)
+	if idx < 0 {
+		if *verbose {
+			f.Warn(call.Pos(), "can't check non-constant format in call to", name)
+		}
+		return
+	}
+
+	firstArg := idx + 1 // Arguments are immediately after format string.
+	if !strings.Contains(format, "%") {
+		if len(call.Args) > firstArg {
+			f.Badf(call.Pos(), "no formatting directive in %s call", name)
+		}
+		return
+	}
+	// Hard part: check formats against args.
+	argNum := firstArg
+	indexed := false
+	for i, w := 0, 0; i < len(format); i += w {
+		w = 1
+		if format[i] == '%' {
+			state := f.parsePrintfVerb(call, name, format[i:], firstArg, argNum)
+			if state == nil {
+				return
+			}
+			w = len(state.format)
+			if state.indexed {
+				indexed = true
+			}
+			if !f.okPrintfArg(call, state) { // One error per format is enough.
+				return
+			}
+			if len(state.argNums) > 0 {
+				// Continue with the next sequential argument.
+				argNum = state.argNums[len(state.argNums)-1] + 1
+			}
+		}
+	}
+	// Dotdotdot is hard.
+	if call.Ellipsis.IsValid() && argNum >= len(call.Args)-1 {
+		return
+	}
+	// If the arguments were direct indexed, we assume the programmer knows what's up.
+	// Otherwise, there should be no leftover arguments.
+	if !indexed && argNum != len(call.Args) {
+		expect := argNum - firstArg
+		numArgs := len(call.Args) - firstArg
+		f.Badf(call.Pos(), "wrong number of args for format in %s call: %d needed but %d args", name, expect, numArgs)
+	}
+}
+
+// parseFlags accepts any printf flags.
+func (s *formatState) parseFlags() {
+	for s.nbytes < len(s.format) {
+		switch c := s.format[s.nbytes]; c {
+		case '#', '0', '+', '-', ' ':
+			s.flags = append(s.flags, c)
+			s.nbytes++
+		default:
+			return
+		}
+	}
+}
+
+// scanNum advances through a decimal number if present.
+func (s *formatState) scanNum() {
+	for ; s.nbytes < len(s.format); s.nbytes++ {
+		c := s.format[s.nbytes]
+		if c < '0' || '9' < c {
+			return
+		}
+	}
+}
+
+// parseIndex scans an index expression. It returns false if there is a syntax error.
+func (s *formatState) parseIndex() bool {
+	if s.nbytes == len(s.format) || s.format[s.nbytes] != '[' {
+		return true
+	}
+	// Argument index present.
+	s.indexed = true
+	s.nbytes++ // skip '['
+	start := s.nbytes
+	s.scanNum()
+	if s.nbytes == len(s.format) || s.nbytes == start || s.format[s.nbytes] != ']' {
+		s.file.Badf(s.call.Pos(), "illegal syntax for printf argument index")
+		return false
+	}
+	arg32, err := strconv.ParseInt(s.format[start:s.nbytes], 10, 32)
+	if err != nil {
+		s.file.Badf(s.call.Pos(), "illegal syntax for printf argument index: %s", err)
+		return false
+	}
+	s.nbytes++ // skip ']'
+	arg := int(arg32)
+	arg += s.firstArg - 1 // We want to zero-index the actual arguments.
+	s.argNum = arg
+	s.indexPending = true
+	return true
+}
+
+// parseNum scans a width or precision (or *). It returns false if there's a bad index expression.
+func (s *formatState) parseNum() bool {
+	if s.nbytes < len(s.format) && s.format[s.nbytes] == '*' {
+		if s.indexPending { // Absorb it.
+			s.indexPending = false
+		}
+		s.nbytes++
+		s.argNums = append(s.argNums, s.argNum)
+		s.argNum++
+	} else {
+		s.scanNum()
+	}
+	return true
+}
+
+// parsePrecision scans for a precision. It returns false if there's a bad index expression.
+func (s *formatState) parsePrecision() bool {
+	// If there's a period, there may be a precision.
+	if s.nbytes < len(s.format) && s.format[s.nbytes] == '.' {
+		s.flags = append(s.flags, '.') // Treat precision as a flag.
+		s.nbytes++
+		if !s.parseIndex() {
+			return false
+		}
+		if !s.parseNum() {
+			return false
+		}
+	}
+	return true
+}
+
+// parsePrintfVerb looks the formatting directive that begins the format string
+// and returns a formatState that encodes what the directive wants, without looking
+// at the actual arguments present in the call. The result is nil if there is an error.
+func (f *File) parsePrintfVerb(call *ast.CallExpr, name, format string, firstArg, argNum int) *formatState {
+	state := &formatState{
+		format:   format,
+		name:     name,
+		flags:    make([]byte, 0, 5),
+		argNum:   argNum,
+		argNums:  make([]int, 0, 1),
+		nbytes:   1, // There's guaranteed to be a percent sign.
+		indexed:  false,
+		firstArg: firstArg,
+		file:     f,
+		call:     call,
+	}
+	// There may be flags.
+	state.parseFlags()
+	indexPending := false
+	// There may be an index.
+	if !state.parseIndex() {
+		return nil
+	}
+	// There may be a width.
+	if !state.parseNum() {
+		return nil
+	}
+	// There may be a precision.
+	if !state.parsePrecision() {
+		return nil
+	}
+	// Now a verb, possibly prefixed by an index (which we may already have).
+	if !indexPending && !state.parseIndex() {
+		return nil
+	}
+	if state.nbytes == len(state.format) {
+		f.Badf(call.Pos(), "missing verb at end of format string in %s call", name)
+		return nil
+	}
+	verb, w := utf8.DecodeRuneInString(state.format[state.nbytes:])
+	state.verb = verb
+	state.nbytes += w
+	if verb != '%' {
+		state.argNums = append(state.argNums, state.argNum)
+	}
+	state.format = state.format[:state.nbytes]
+	return state
+}
+
+// printfArgType encodes the types of expressions a printf verb accepts. It is a bitmask.
+type printfArgType int
+
+const (
+	argBool printfArgType = 1 << iota
+	argInt
+	argRune
+	argString
+	argFloat
+	argComplex
+	argPointer
+	anyType printfArgType = ^0
+)
+
+type printVerb struct {
+	verb  rune   // User may provide verb through Formatter; could be a rune.
+	flags string // known flags are all ASCII
+	typ   printfArgType
+}
+
+// Common flag sets for printf verbs.
+const (
+	noFlag       = ""
+	numFlag      = " -+.0"
+	sharpNumFlag = " -+.0#"
+	allFlags     = " -+.0#"
+)
+
+// printVerbs identifies which flags are known to printf for each verb.
+// TODO: A type that implements Formatter may do what it wants, and vet
+// will complain incorrectly.
+var printVerbs = []printVerb{
+	// '-' is a width modifier, always valid.
+	// '.' is a precision for float, max width for strings.
+	// '+' is required sign for numbers, Go format for %v.
+	// '#' is alternate format for several verbs.
+	// ' ' is spacer for numbers
+	{'%', noFlag, 0},
+	{'b', numFlag, argInt | argFloat | argComplex},
+	{'c', "-", argRune | argInt},
+	{'d', numFlag, argInt},
+	{'e', numFlag, argFloat | argComplex},
+	{'E', numFlag, argFloat | argComplex},
+	{'f', numFlag, argFloat | argComplex},
+	{'F', numFlag, argFloat | argComplex},
+	{'g', numFlag, argFloat | argComplex},
+	{'G', numFlag, argFloat | argComplex},
+	{'o', sharpNumFlag, argInt},
+	{'p', "-#", argPointer},
+	{'q', " -+.0#", argRune | argInt | argString},
+	{'s', " -+.0", argString},
+	{'t', "-", argBool},
+	{'T', "-", anyType},
+	{'U', "-#", argRune | argInt},
+	{'v', allFlags, anyType},
+	{'x', sharpNumFlag, argRune | argInt | argString},
+	{'X', sharpNumFlag, argRune | argInt | argString},
+}
+
+// okPrintfArg compares the formatState to the arguments actually present,
+// reporting any discrepancies it can discern. If the final argument is ellipsissed,
+// there's little it can do for that.
+func (f *File) okPrintfArg(call *ast.CallExpr, state *formatState) (ok bool) {
+	var v printVerb
+	found := false
+	// Linear scan is fast enough for a small list.
+	for _, v = range printVerbs {
+		if v.verb == state.verb {
+			found = true
+			break
+		}
+	}
+	if !found {
+		f.Badf(call.Pos(), "unrecognized printf verb %q", state.verb)
+		return false
+	}
+	for _, flag := range state.flags {
+		if !strings.ContainsRune(v.flags, rune(flag)) {
+			f.Badf(call.Pos(), "unrecognized printf flag for verb %q: %q", state.verb, flag)
+			return false
+		}
+	}
+	// Verb is good. If len(state.argNums)>trueArgs, we have something like %.*s and all
+	// but the final arg must be an integer.
+	trueArgs := 1
+	if state.verb == '%' {
+		trueArgs = 0
+	}
+	nargs := len(state.argNums)
+	for i := 0; i < nargs-trueArgs; i++ {
+		argNum := state.argNums[i]
+		if !f.argCanBeChecked(call, i, true, state) {
+			return
+		}
+		arg := call.Args[argNum]
+		if !f.matchArgType(argInt, nil, arg) {
+			f.Badf(call.Pos(), "arg %s for * in printf format not of type int", f.gofmt(arg))
+			return false
+		}
+	}
+	if state.verb == '%' {
+		return true
+	}
+	argNum := state.argNums[len(state.argNums)-1]
+	if !f.argCanBeChecked(call, len(state.argNums)-1, false, state) {
+		return false
+	}
+	arg := call.Args[argNum]
+	if f.isFunctionValue(arg) && state.verb != 'p' && state.verb != 'T' {
+		f.Badf(call.Pos(), "arg %s in printf call is a function value, not a function call", f.gofmt(arg))
+		return false
+	}
+	if !f.matchArgType(v.typ, nil, arg) {
+		typeString := ""
+		if typ := f.pkg.types[arg].Type; typ != nil {
+			typeString = typ.String()
+		}
+		f.Badf(call.Pos(), "arg %s for printf verb %%%c of wrong type: %s", f.gofmt(arg), state.verb, typeString)
+		return false
+	}
+	if v.typ&argString != 0 && v.verb != 'T' && !bytes.Contains(state.flags, []byte{'#'}) && f.recursiveStringer(arg) {
+		f.Badf(call.Pos(), "arg %s for printf causes recursive call to String method", f.gofmt(arg))
+		return false
+	}
+	return true
+}
+
+// recursiveStringer reports whether the provided argument is r or &r for the
+// fmt.Stringer receiver identifier r.
+func (f *File) recursiveStringer(e ast.Expr) bool {
+	if len(f.stringers) == 0 {
+		return false
+	}
+	var obj *ast.Object
+	switch e := e.(type) {
+	case *ast.Ident:
+		obj = e.Obj
+	case *ast.UnaryExpr:
+		if id, ok := e.X.(*ast.Ident); ok && e.Op == token.AND {
+			obj = id.Obj
+		}
+	}
+
+	// It's unlikely to be a recursive stringer if it has a Format method.
+	if typ := f.pkg.types[e].Type; typ != nil {
+		// Not a perfect match; see issue 6259.
+		if f.hasMethod(typ, "Format") {
+			return false
+		}
+	}
+
+	// We compare the underlying Object, which checks that the identifier
+	// is the one we declared as the receiver for the String method in
+	// which this printf appears.
+	return f.stringers[obj]
+}
+
+// isFunctionValue reports whether the expression is a function as opposed to a function call.
+// It is almost always a mistake to print a function value.
+func (f *File) isFunctionValue(e ast.Expr) bool {
+	if typ := f.pkg.types[e].Type; typ != nil {
+		_, ok := typ.(*types.Signature)
+		return ok
+	}
+	return false
+}
+
+// argCanBeChecked reports whether the specified argument is statically present;
+// it may be beyond the list of arguments or in a terminal slice... argument, which
+// means we can't see it.
+func (f *File) argCanBeChecked(call *ast.CallExpr, formatArg int, isStar bool, state *formatState) bool {
+	argNum := state.argNums[formatArg]
+	if argNum < 0 {
+		// Shouldn't happen, so catch it with prejudice.
+		panic("negative arg num")
+	}
+	if argNum == 0 {
+		f.Badf(call.Pos(), `index value [0] for %s("%s"); indexes start at 1`, state.name, state.format)
+		return false
+	}
+	if argNum < len(call.Args)-1 {
+		return true // Always OK.
+	}
+	if call.Ellipsis.IsValid() {
+		return false // We just can't tell; there could be many more arguments.
+	}
+	if argNum < len(call.Args) {
+		return true
+	}
+	// There are bad indexes in the format or there are fewer arguments than the format needs.
+	// This is the argument number relative to the format: Printf("%s", "hi") will give 1 for the "hi".
+	arg := argNum - state.firstArg + 1 // People think of arguments as 1-indexed.
+	f.Badf(call.Pos(), `missing argument for %s("%s"): format reads arg %d, have only %d args`, state.name, state.format, arg, len(call.Args)-state.firstArg)
+	return false
+}
+
+// checkPrint checks a call to an unformatted print routine such as Println.
+func (f *File) checkPrint(call *ast.CallExpr, name string) {
+	firstArg := 0
+	typ := f.pkg.types[call.Fun].Type
+	if typ == nil {
+		// Skip checking functions with unknown type.
+		return
+	}
+	if sig, ok := typ.(*types.Signature); ok {
+		if !sig.Variadic() {
+			// Skip checking non-variadic functions.
+			return
+		}
+		params := sig.Params()
+		firstArg = params.Len() - 1
+
+		typ := params.At(firstArg).Type()
+		typ = typ.(*types.Slice).Elem()
+		it, ok := typ.(*types.Interface)
+		if !ok || !it.Empty() {
+			// Skip variadic functions accepting non-interface{} args.
+			return
+		}
+	}
+	args := call.Args
+	if len(args) <= firstArg {
+		// Skip calls without variadic args.
+		return
+	}
+	args = args[firstArg:]
+
+	// check for Println(os.Stderr, ...)
+	if firstArg == 0 {
+		if sel, ok := args[0].(*ast.SelectorExpr); ok {
+			if x, ok := sel.X.(*ast.Ident); ok {
+				if x.Name == "os" && strings.HasPrefix(sel.Sel.Name, "Std") {
+					f.Badf(call.Pos(), "first argument to %s is %s.%s", name, x.Name, sel.Sel.Name)
+				}
+			}
+		}
+	}
+	arg := args[0]
+	if lit, ok := arg.(*ast.BasicLit); ok && lit.Kind == token.STRING {
+		if strings.Contains(lit.Value, "%") {
+			f.Badf(call.Pos(), "possible formatting directive in %s call", name)
+		}
+	}
+	if strings.HasSuffix(name, "ln") {
+		// The last item, if a string, should not have a newline.
+		arg = args[len(args)-1]
+		if lit, ok := arg.(*ast.BasicLit); ok && lit.Kind == token.STRING {
+			if strings.HasSuffix(lit.Value, `\n"`) {
+				f.Badf(call.Pos(), "%s call ends with newline", name)
+			}
+		}
+	}
+	for _, arg := range args {
+		if f.isFunctionValue(arg) {
+			f.Badf(call.Pos(), "arg %s in %s call is a function value, not a function call", f.gofmt(arg), name)
+		}
+		if f.recursiveStringer(arg) {
+			f.Badf(call.Pos(), "arg %s in %s call causes recursive call to String method", f.gofmt(arg), name)
+		}
+	}
+}

tools/vendor/github.com/dnephin/govet/rangeloop.go

@@ -0,0 +1,74 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+/*
+This file contains the code to check range loop variables bound inside function
+literals that are deferred or launched in new goroutines. We only check
+instances where the defer or go statement is the last statement in the loop
+body, as otherwise we would need whole program analysis.
+
+For example:
+
+	for i, v := range s {
+		go func() {
+			println(i, v) // not what you might expect
+		}()
+	}
+
+See: https://golang.org/doc/go_faq.html#closures_and_goroutines
+*/
+
+package main
+
+import "go/ast"
+
+func init() {
+	register("rangeloops",
+		"check that range loop variables are used correctly",
+		checkRangeLoop,
+		rangeStmt)
+}
+
+// checkRangeLoop walks the body of the provided range statement, checking if
+// its index or value variables are used unsafely inside goroutines or deferred
+// function literals.
+func checkRangeLoop(f *File, node ast.Node) {
+	n := node.(*ast.RangeStmt)
+	key, _ := n.Key.(*ast.Ident)
+	val, _ := n.Value.(*ast.Ident)
+	if key == nil && val == nil {
+		return
+	}
+	sl := n.Body.List
+	if len(sl) == 0 {
+		return
+	}
+	var last *ast.CallExpr
+	switch s := sl[len(sl)-1].(type) {
+	case *ast.GoStmt:
+		last = s.Call
+	case *ast.DeferStmt:
+		last = s.Call
+	default:
+		return
+	}
+	lit, ok := last.Fun.(*ast.FuncLit)
+	if !ok {
+		return
+	}
+	ast.Inspect(lit.Body, func(n ast.Node) bool {
+		id, ok := n.(*ast.Ident)
+		if !ok || id.Obj == nil {
+			return true
+		}
+		if f.pkg.types[id].Type == nil {
+			// Not referring to a variable
+			return true
+		}
+		if key != nil && id.Obj == key.Obj || val != nil && id.Obj == val.Obj {
+			f.Bad(id.Pos(), "range variable", id.Name, "captured by func literal")
+		}
+		return true
+	})
+}

tools/vendor/github.com/dnephin/govet/shadow.go

@@ -0,0 +1,246 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+/*
+This file contains the code to check for shadowed variables.
+A shadowed variable is a variable declared in an inner scope
+with the same name and type as a variable in an outer scope,
+and where the outer variable is mentioned after the inner one
+is declared.
+
+(This definition can be refined; the module generates too many
+false positives and is not yet enabled by default.)
+
+For example:
+
+	func BadRead(f *os.File, buf []byte) error {
+		var err error
+		for {
+			n, err := f.Read(buf) // shadows the function variable 'err'
+			if err != nil {
+				break // causes return of wrong value
+			}
+			foo(buf)
+		}
+		return err
+	}
+
+*/
+
+package main
+
+import (
+	"flag"
+	"go/ast"
+	"go/token"
+	"go/types"
+)
+
+var strictShadowing = flag.Bool("shadowstrict", false, "whether to be strict about shadowing; can be noisy")
+
+func init() {
+	register("shadow",
+		"check for shadowed variables (experimental; must be set explicitly)",
+		checkShadow,
+		assignStmt, genDecl)
+	experimental["shadow"] = true
+}
+
+func checkShadow(f *File, node ast.Node) {
+	switch n := node.(type) {
+	case *ast.AssignStmt:
+		checkShadowAssignment(f, n)
+	case *ast.GenDecl:
+		checkShadowDecl(f, n)
+	}
+}
+
+// Span stores the minimum range of byte positions in the file in which a
+// given variable (types.Object) is mentioned. It is lexically defined: it spans
+// from the beginning of its first mention to the end of its last mention.
+// A variable is considered shadowed (if *strictShadowing is off) only if the
+// shadowing variable is declared within the span of the shadowed variable.
+// In other words, if a variable is shadowed but not used after the shadowed
+// variable is declared, it is inconsequential and not worth complaining about.
+// This simple check dramatically reduces the nuisance rate for the shadowing
+// check, at least until something cleverer comes along.
+//
+// One wrinkle: A "naked return" is a silent use of a variable that the Span
+// will not capture, but the compilers catch naked returns of shadowed
+// variables so we don't need to.
+//
+// Cases this gets wrong (TODO):
+// - If a for loop's continuation statement mentions a variable redeclared in
+// the block, we should complain about it but don't.
+// - A variable declared inside a function literal can falsely be identified
+// as shadowing a variable in the outer function.
+//
+type Span struct {
+	min token.Pos
+	max token.Pos
+}
+
+// contains reports whether the position is inside the span.
+func (s Span) contains(pos token.Pos) bool {
+	return s.min <= pos && pos < s.max
+}
+
+// growSpan expands the span for the object to contain the instance represented
+// by the identifier.
+func (pkg *Package) growSpan(ident *ast.Ident, obj types.Object) {
+	if *strictShadowing {
+		return // No need
+	}
+	pos := ident.Pos()
+	end := ident.End()
+	span, ok := pkg.spans[obj]
+	if ok {
+		if span.min > pos {
+			span.min = pos
+		}
+		if span.max < end {
+			span.max = end
+		}
+	} else {
+		span = Span{pos, end}
+	}
+	pkg.spans[obj] = span
+}
+
+// checkShadowAssignment checks for shadowing in a short variable declaration.
+func checkShadowAssignment(f *File, a *ast.AssignStmt) {
+	if a.Tok != token.DEFINE {
+		return
+	}
+	if f.idiomaticShortRedecl(a) {
+		return
+	}
+	for _, expr := range a.Lhs {
+		ident, ok := expr.(*ast.Ident)
+		if !ok {
+			f.Badf(expr.Pos(), "invalid AST: short variable declaration of non-identifier")
+			return
+		}
+		checkShadowing(f, ident)
+	}
+}
+
+// idiomaticShortRedecl reports whether this short declaration can be ignored for
+// the purposes of shadowing, that is, that any redeclarations it contains are deliberate.
+func (f *File) idiomaticShortRedecl(a *ast.AssignStmt) bool {
+	// Don't complain about deliberate redeclarations of the form
+	//	i := i
+	// Such constructs are idiomatic in range loops to create a new variable
+	// for each iteration. Another example is
+	//	switch n := n.(type)
+	if len(a.Rhs) != len(a.Lhs) {
+		return false
+	}
+	// We know it's an assignment, so the LHS must be all identifiers. (We check anyway.)
+	for i, expr := range a.Lhs {
+		lhs, ok := expr.(*ast.Ident)
+		if !ok {
+			f.Badf(expr.Pos(), "invalid AST: short variable declaration of non-identifier")
+			return true // Don't do any more processing.
+		}
+		switch rhs := a.Rhs[i].(type) {
+		case *ast.Ident:
+			if lhs.Name != rhs.Name {
+				return false
+			}
+		case *ast.TypeAssertExpr:
+			if id, ok := rhs.X.(*ast.Ident); ok {
+				if lhs.Name != id.Name {
+					return false
+				}
+			}
+		default:
+			return false
+		}
+	}
+	return true
+}
+
+// idiomaticRedecl reports whether this declaration spec can be ignored for
+// the purposes of shadowing, that is, that any redeclarations it contains are deliberate.
+func (f *File) idiomaticRedecl(d *ast.ValueSpec) bool {
+	// Don't complain about deliberate redeclarations of the form
+	//	var i, j = i, j
+	if len(d.Names) != len(d.Values) {
+		return false
+	}
+	for i, lhs := range d.Names {
+		if rhs, ok := d.Values[i].(*ast.Ident); ok {
+			if lhs.Name != rhs.Name {
+				return false
+			}
+		}
+	}
+	return true
+}
+
+// checkShadowDecl checks for shadowing in a general variable declaration.
+func checkShadowDecl(f *File, d *ast.GenDecl) {
+	if d.Tok != token.VAR {
+		return
+	}
+	for _, spec := range d.Specs {
+		valueSpec, ok := spec.(*ast.ValueSpec)
+		if !ok {
+			f.Badf(spec.Pos(), "invalid AST: var GenDecl not ValueSpec")
+			return
+		}
+		// Don't complain about deliberate redeclarations of the form
+		//	var i = i
+		if f.idiomaticRedecl(valueSpec) {
+			return
+		}
+		for _, ident := range valueSpec.Names {
+			checkShadowing(f, ident)
+		}
+	}
+}
+
+// checkShadowing checks whether the identifier shadows an identifier in an outer scope.
+func checkShadowing(f *File, ident *ast.Ident) {
+	if ident.Name == "_" {
+		// Can't shadow the blank identifier.
+		return
+	}
+	obj := f.pkg.defs[ident]
+	if obj == nil {
+		return
+	}
+	// obj.Parent.Parent is the surrounding scope. If we can find another declaration
+	// starting from there, we have a shadowed identifier.
+	_, shadowed := obj.Parent().Parent().LookupParent(obj.Name(), obj.Pos())
+	if shadowed == nil {
+		return
+	}
+	// Don't complain if it's shadowing a universe-declared identifier; that's fine.
+	if shadowed.Parent() == types.Universe {
+		return
+	}
+	if *strictShadowing {
+		// The shadowed identifier must appear before this one to be an instance of shadowing.
+		if shadowed.Pos() > ident.Pos() {
+			return
+		}
+	} else {
+		// Don't complain if the span of validity of the shadowed identifier doesn't include
+		// the shadowing identifier.
+		span, ok := f.pkg.spans[shadowed]
+		if !ok {
+			f.Badf(ident.Pos(), "internal error: no range for %q", ident.Name)
+			return
+		}
+		if !span.contains(ident.Pos()) {
+			return
+		}
+	}
+	// Don't complain if the types differ: that implies the programmer really wants two different things.
+	if types.Identical(obj.Type(), shadowed.Type()) {
+		f.Badf(ident.Pos(), "declaration of %q shadows declaration at %s", obj.Name(), f.loc(shadowed.Pos()))
+	}
+}

tools/vendor/github.com/dnephin/govet/shift.go

@@ -0,0 +1,82 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+/*
+This file contains the code to check for suspicious shifts.
+*/
+
+package main
+
+import (
+	"go/ast"
+	"go/constant"
+	"go/token"
+	"go/types"
+)
+
+func init() {
+	register("shift",
+		"check for useless shifts",
+		checkShift,
+		binaryExpr, assignStmt)
+}
+
+func checkShift(f *File, node ast.Node) {
+	switch node := node.(type) {
+	case *ast.BinaryExpr:
+		if node.Op == token.SHL || node.Op == token.SHR {
+			checkLongShift(f, node, node.X, node.Y)
+		}
+	case *ast.AssignStmt:
+		if len(node.Lhs) != 1 || len(node.Rhs) != 1 {
+			return
+		}
+		if node.Tok == token.SHL_ASSIGN || node.Tok == token.SHR_ASSIGN {
+			checkLongShift(f, node, node.Lhs[0], node.Rhs[0])
+		}
+	}
+}
+
+// checkLongShift checks if shift or shift-assign operations shift by more than
+// the length of the underlying variable.
+func checkLongShift(f *File, node ast.Node, x, y ast.Expr) {
+	v := f.pkg.types[y].Value
+	if v == nil {
+		return
+	}
+	amt, ok := constant.Int64Val(v)
+	if !ok {
+		return
+	}
+	t := f.pkg.types[x].Type
+	if t == nil {
+		return
+	}
+	b, ok := t.Underlying().(*types.Basic)
+	if !ok {
+		return
+	}
+	var size int64
+	var msg string
+	switch b.Kind() {
+	case types.Uint8, types.Int8:
+		size = 8
+	case types.Uint16, types.Int16:
+		size = 16
+	case types.Uint32, types.Int32:
+		size = 32
+	case types.Uint64, types.Int64:
+		size = 64
+	case types.Int, types.Uint, types.Uintptr:
+		// These types may be as small as 32 bits, but no smaller.
+		size = 32
+		msg = "might be "
+	default:
+		return
+	}
+	if amt >= size {
+		ident := f.gofmt(x)
+		f.Badf(node.Pos(), "%s %stoo small for shift of %d", ident, msg, amt)
+	}
+}

tools/vendor/github.com/dnephin/govet/structtag.go

@@ -0,0 +1,122 @@
+// Copyright 2010 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file contains the test for canonical struct tags.
+
+package main
+
+import (
+	"errors"
+	"go/ast"
+	"reflect"
+	"strconv"
+)
+
+func init() {
+	register("structtags",
+		"check that struct field tags have canonical format and apply to exported fields as needed",
+		checkCanonicalFieldTag,
+		field)
+}
+
+// checkCanonicalFieldTag checks a struct field tag.
+func checkCanonicalFieldTag(f *File, node ast.Node) {
+	field := node.(*ast.Field)
+	if field.Tag == nil {
+		return
+	}
+
+	tag, err := strconv.Unquote(field.Tag.Value)
+	if err != nil {
+		f.Badf(field.Pos(), "unable to read struct tag %s", field.Tag.Value)
+		return
+	}
+
+	if err := validateStructTag(tag); err != nil {
+		f.Badf(field.Pos(), "struct field tag %s not compatible with reflect.StructTag.Get: %s", field.Tag.Value, err)
+	}
+
+	// Check for use of json or xml tags with unexported fields.
+
+	// Embedded struct. Nothing to do for now, but that
+	// may change, depending on what happens with issue 7363.
+	if len(field.Names) == 0 {
+		return
+	}
+
+	if field.Names[0].IsExported() {
+		return
+	}
+
+	st := reflect.StructTag(tag)
+	for _, enc := range [...]string{"json", "xml"} {
+		if st.Get(enc) != "" {
+			f.Badf(field.Pos(), "struct field %s has %s tag but is not exported", field.Names[0].Name, enc)
+			return
+		}
+	}
+}
+
+var (
+	errTagSyntax      = errors.New("bad syntax for struct tag pair")
+	errTagKeySyntax   = errors.New("bad syntax for struct tag key")
+	errTagValueSyntax = errors.New("bad syntax for struct tag value")
+)
+
+// validateStructTag parses the struct tag and returns an error if it is not
+// in the canonical format, which is a space-separated list of key:"value"
+// settings. The value may contain spaces.
+func validateStructTag(tag string) error {
+	// This code is based on the StructTag.Get code in package reflect.
+
+	for tag != "" {
+		// Skip leading space.
+		i := 0
+		for i < len(tag) && tag[i] == ' ' {
+			i++
+		}
+		tag = tag[i:]
+		if tag == "" {
+			break
+		}
+
+		// Scan to colon. A space, a quote or a control character is a syntax error.
+		// Strictly speaking, control chars include the range [0x7f, 0x9f], not just
+		// [0x00, 0x1f], but in practice, we ignore the multi-byte control characters
+		// as it is simpler to inspect the tag's bytes than the tag's runes.
+		i = 0
+		for i < len(tag) && tag[i] > ' ' && tag[i] != ':' && tag[i] != '"' && tag[i] != 0x7f {
+			i++
+		}
+		if i == 0 {
+			return errTagKeySyntax
+		}
+		if i+1 >= len(tag) || tag[i] != ':' {
+			return errTagSyntax
+		}
+		if tag[i+1] != '"' {
+			return errTagValueSyntax
+		}
+		tag = tag[i+1:]
+
+		// Scan quoted string to find value.
+		i = 1
+		for i < len(tag) && tag[i] != '"' {
+			if tag[i] == '\\' {
+				i++
+			}
+			i++
+		}
+		if i >= len(tag) {
+			return errTagValueSyntax
+		}
+		qvalue := tag[:i+1]
+		tag = tag[i+1:]
+
+		if _, err := strconv.Unquote(qvalue); err != nil {
+			return errTagValueSyntax
+		}
+	}
+	return nil
+}

tools/vendor/github.com/dnephin/govet/tests.go

@@ -0,0 +1,187 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"go/ast"
+	"go/types"
+	"strings"
+	"unicode"
+	"unicode/utf8"
+)
+
+func init() {
+	register("tests",
+		"check for common mistaken usages of tests/documentation examples",
+		checkTestFunctions,
+		funcDecl)
+}
+
+func isExampleSuffix(s string) bool {
+	r, size := utf8.DecodeRuneInString(s)
+	return size > 0 && unicode.IsLower(r)
+}
+
+func isTestSuffix(name string) bool {
+	if len(name) == 0 {
+		// "Test" is ok.
+		return true
+	}
+	r, _ := utf8.DecodeRuneInString(name)
+	return !unicode.IsLower(r)
+}
+
+func isTestParam(typ ast.Expr, wantType string) bool {
+	ptr, ok := typ.(*ast.StarExpr)
+	if !ok {
+		// Not a pointer.
+		return false
+	}
+	// No easy way of making sure it's a *testing.T or *testing.B:
+	// ensure the name of the type matches.
+	if name, ok := ptr.X.(*ast.Ident); ok {
+		return name.Name == wantType
+	}
+	if sel, ok := ptr.X.(*ast.SelectorExpr); ok {
+		return sel.Sel.Name == wantType
+	}
+	return false
+}
+
+func lookup(name string, scopes []*types.Scope) types.Object {
+	for _, scope := range scopes {
+		if o := scope.Lookup(name); o != nil {
+			return o
+		}
+	}
+	return nil
+}
+
+func extendedScope(f *File) []*types.Scope {
+	scopes := []*types.Scope{f.pkg.typesPkg.Scope()}
+	if f.basePkg != nil {
+		scopes = append(scopes, f.basePkg.typesPkg.Scope())
+	} else {
+		// If basePkg is not specified (e.g. when checking a single file) try to
+		// find it among imports.
+		pkgName := f.pkg.typesPkg.Name()
+		if strings.HasSuffix(pkgName, "_test") {
+			basePkgName := strings.TrimSuffix(pkgName, "_test")
+			for _, p := range f.pkg.typesPkg.Imports() {
+				if p.Name() == basePkgName {
+					scopes = append(scopes, p.Scope())
+					break
+				}
+			}
+		}
+	}
+	return scopes
+}
+
+func checkExample(fn *ast.FuncDecl, f *File, report reporter) {
+	fnName := fn.Name.Name
+	if params := fn.Type.Params; len(params.List) != 0 {
+		report("%s should be niladic", fnName)
+	}
+	if results := fn.Type.Results; results != nil && len(results.List) != 0 {
+		report("%s should return nothing", fnName)
+	}
+
+	if filesRun && !includesNonTest {
+		// The coherence checks between a test and the package it tests
+		// will report false positives if no non-test files have
+		// been provided.
+		return
+	}
+
+	if fnName == "Example" {
+		// Nothing more to do.
+		return
+	}
+
+	var (
+		exName = strings.TrimPrefix(fnName, "Example")
+		elems  = strings.SplitN(exName, "_", 3)
+		ident  = elems[0]
+		obj    = lookup(ident, extendedScope(f))
+	)
+	if ident != "" && obj == nil {
+		// Check ExampleFoo and ExampleBadFoo.
+		report("%s refers to unknown identifier: %s", fnName, ident)
+		// Abort since obj is absent and no subsequent checks can be performed.
+		return
+	}
+	if len(elems) < 2 {
+		// Nothing more to do.
+		return
+	}
+
+	if ident == "" {
+		// Check Example_suffix and Example_BadSuffix.
+		if residual := strings.TrimPrefix(exName, "_"); !isExampleSuffix(residual) {
+			report("%s has malformed example suffix: %s", fnName, residual)
+		}
+		return
+	}
+
+	mmbr := elems[1]
+	if !isExampleSuffix(mmbr) {
+		// Check ExampleFoo_Method and ExampleFoo_BadMethod.
+		if obj, _, _ := types.LookupFieldOrMethod(obj.Type(), true, obj.Pkg(), mmbr); obj == nil {
+			report("%s refers to unknown field or method: %s.%s", fnName, ident, mmbr)
+		}
+	}
+	if len(elems) == 3 && !isExampleSuffix(elems[2]) {
+		// Check ExampleFoo_Method_suffix and ExampleFoo_Method_Badsuffix.
+		report("%s has malformed example suffix: %s", fnName, elems[2])
+	}
+}
+
+func checkTest(fn *ast.FuncDecl, prefix string, report reporter) {
+	// Want functions with 0 results and 1 parameter.
+	if fn.Type.Results != nil && len(fn.Type.Results.List) > 0 ||
+		fn.Type.Params == nil ||
+		len(fn.Type.Params.List) != 1 ||
+		len(fn.Type.Params.List[0].Names) > 1 {
+		return
+	}
+
+	// The param must look like a *testing.T or *testing.B.
+	if !isTestParam(fn.Type.Params.List[0].Type, prefix[:1]) {
+		return
+	}
+
+	if !isTestSuffix(fn.Name.Name[len(prefix):]) {
+		report("%s has malformed name: first letter after '%s' must not be lowercase", fn.Name.Name, prefix)
+	}
+}
+
+type reporter func(format string, args ...interface{})
+
+// checkTestFunctions walks Test, Benchmark and Example functions checking
+// malformed names, wrong signatures and examples documenting inexistent
+// identifiers.
+func checkTestFunctions(f *File, node ast.Node) {
+	if !strings.HasSuffix(f.name, "_test.go") {
+		return
+	}
+
+	fn, ok := node.(*ast.FuncDecl)
+	if !ok || fn.Recv != nil {
+		// Ignore non-functions or functions with receivers.
+		return
+	}
+
+	report := func(format string, args ...interface{}) { f.Badf(node.Pos(), format, args...) }
+
+	switch {
+	case strings.HasPrefix(fn.Name.Name, "Example"):
+		checkExample(fn, f, report)
+	case strings.HasPrefix(fn.Name.Name, "Test"):
+		checkTest(fn, "Test", report)
+	case strings.HasPrefix(fn.Name.Name, "Benchmark"):
+		checkTest(fn, "Benchmark", report)
+	}
+}

tools/vendor/github.com/dnephin/govet/types.go

@@ -0,0 +1,281 @@
+// Copyright 2010 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file contains the pieces of the tool that use typechecking from the go/types package.
+
+package main
+
+import (
+	"go/ast"
+	"go/importer"
+	"go/token"
+	"go/types"
+)
+
+// stdImporter is the importer we use to import packages.
+// It is created during initialization so that all packages
+// are imported by the same importer.
+var stdImporter = importer.Default()
+
+var (
+	errorType     *types.Interface
+	stringerType  *types.Interface // possibly nil
+	formatterType *types.Interface // possibly nil
+)
+
+func init() {
+	errorType = types.Universe.Lookup("error").Type().Underlying().(*types.Interface)
+
+	if typ := importType("fmt", "Stringer"); typ != nil {
+		stringerType = typ.Underlying().(*types.Interface)
+	}
+
+	if typ := importType("fmt", "Formatter"); typ != nil {
+		formatterType = typ.Underlying().(*types.Interface)
+	}
+}
+
+// importType returns the type denoted by the qualified identifier
+// path.name, and adds the respective package to the imports map
+// as a side effect. In case of an error, importType returns nil.
+func importType(path, name string) types.Type {
+	pkg, err := stdImporter.Import(path)
+	if err != nil {
+		// This can happen if the package at path hasn't been compiled yet.
+		warnf("import failed: %v", err)
+		return nil
+	}
+	if obj, ok := pkg.Scope().Lookup(name).(*types.TypeName); ok {
+		return obj.Type()
+	}
+	warnf("invalid type name %q", name)
+	return nil
+}
+
+func (pkg *Package) check(fs *token.FileSet, astFiles []*ast.File) error {
+	pkg.defs = make(map[*ast.Ident]types.Object)
+	pkg.uses = make(map[*ast.Ident]types.Object)
+	pkg.selectors = make(map[*ast.SelectorExpr]*types.Selection)
+	pkg.spans = make(map[types.Object]Span)
+	pkg.types = make(map[ast.Expr]types.TypeAndValue)
+	config := types.Config{
+		// We use the same importer for all imports to ensure that
+		// everybody sees identical packages for the given paths.
+		Importer: stdImporter,
+		// By providing a Config with our own error function, it will continue
+		// past the first error. There is no need for that function to do anything.
+		Error: func(error) {},
+	}
+	info := &types.Info{
+		Selections: pkg.selectors,
+		Types:      pkg.types,
+		Defs:       pkg.defs,
+		Uses:       pkg.uses,
+	}
+	typesPkg, err := config.Check(pkg.path, fs, astFiles, info)
+	pkg.typesPkg = typesPkg
+	// update spans
+	for id, obj := range pkg.defs {
+		pkg.growSpan(id, obj)
+	}
+	for id, obj := range pkg.uses {
+		pkg.growSpan(id, obj)
+	}
+	return err
+}
+
+// matchArgType reports an error if printf verb t is not appropriate
+// for operand arg.
+//
+// typ is used only for recursive calls; external callers must supply nil.
+//
+// (Recursion arises from the compound types {map,chan,slice} which
+// may be printed with %d etc. if that is appropriate for their element
+// types.)
+func (f *File) matchArgType(t printfArgType, typ types.Type, arg ast.Expr) bool {
+	return f.matchArgTypeInternal(t, typ, arg, make(map[types.Type]bool))
+}
+
+// matchArgTypeInternal is the internal version of matchArgType. It carries a map
+// remembering what types are in progress so we don't recur when faced with recursive
+// types or mutually recursive types.
+func (f *File) matchArgTypeInternal(t printfArgType, typ types.Type, arg ast.Expr, inProgress map[types.Type]bool) bool {
+	// %v, %T accept any argument type.
+	if t == anyType {
+		return true
+	}
+	if typ == nil {
+		// external call
+		typ = f.pkg.types[arg].Type
+		if typ == nil {
+			return true // probably a type check problem
+		}
+	}
+	// If the type implements fmt.Formatter, we have nothing to check.
+	// formatterTyp may be nil - be conservative and check for Format method in that case.
+	if formatterType != nil && types.Implements(typ, formatterType) || f.hasMethod(typ, "Format") {
+		return true
+	}
+	// If we can use a string, might arg (dynamically) implement the Stringer or Error interface?
+	if t&argString != 0 {
+		if types.AssertableTo(errorType, typ) || stringerType != nil && types.AssertableTo(stringerType, typ) {
+			return true
+		}
+	}
+
+	typ = typ.Underlying()
+	if inProgress[typ] {
+		// We're already looking at this type. The call that started it will take care of it.
+		return true
+	}
+	inProgress[typ] = true
+
+	switch typ := typ.(type) {
+	case *types.Signature:
+		return t&argPointer != 0
+
+	case *types.Map:
+		// Recur: map[int]int matches %d.
+		return t&argPointer != 0 ||
+			(f.matchArgTypeInternal(t, typ.Key(), arg, inProgress) && f.matchArgTypeInternal(t, typ.Elem(), arg, inProgress))
+
+	case *types.Chan:
+		return t&argPointer != 0
+
+	case *types.Array:
+		// Same as slice.
+		if types.Identical(typ.Elem().Underlying(), types.Typ[types.Byte]) && t&argString != 0 {
+			return true // %s matches []byte
+		}
+		// Recur: []int matches %d.
+		return t&argPointer != 0 || f.matchArgTypeInternal(t, typ.Elem().Underlying(), arg, inProgress)
+
+	case *types.Slice:
+		// Same as array.
+		if types.Identical(typ.Elem().Underlying(), types.Typ[types.Byte]) && t&argString != 0 {
+			return true // %s matches []byte
+		}
+		// Recur: []int matches %d. But watch out for
+		//	type T []T
+		// If the element is a pointer type (type T[]*T), it's handled fine by the Pointer case below.
+		return t&argPointer != 0 || f.matchArgTypeInternal(t, typ.Elem(), arg, inProgress)
+
+	case *types.Pointer:
+		// Ugly, but dealing with an edge case: a known pointer to an invalid type,
+		// probably something from a failed import.
+		if typ.Elem().String() == "invalid type" {
+			if *verbose {
+				f.Warnf(arg.Pos(), "printf argument %v is pointer to invalid or unknown type", f.gofmt(arg))
+			}
+			return true // special case
+		}
+		// If it's actually a pointer with %p, it prints as one.
+		if t == argPointer {
+			return true
+		}
+		// If it's pointer to struct, that's equivalent in our analysis to whether we can print the struct.
+		if str, ok := typ.Elem().Underlying().(*types.Struct); ok {
+			return f.matchStructArgType(t, str, arg, inProgress)
+		}
+		// The rest can print with %p as pointers, or as integers with %x etc.
+		return t&(argInt|argPointer) != 0
+
+	case *types.Struct:
+		return f.matchStructArgType(t, typ, arg, inProgress)
+
+	case *types.Interface:
+		// If the static type of the argument is empty interface, there's little we can do.
+		// Example:
+		//	func f(x interface{}) { fmt.Printf("%s", x) }
+		// Whether x is valid for %s depends on the type of the argument to f. One day
+		// we will be able to do better. For now, we assume that empty interface is OK
+		// but non-empty interfaces, with Stringer and Error handled above, are errors.
+		return typ.NumMethods() == 0
+
+	case *types.Basic:
+		switch typ.Kind() {
+		case types.UntypedBool,
+			types.Bool:
+			return t&argBool != 0
+
+		case types.UntypedInt,
+			types.Int,
+			types.Int8,
+			types.Int16,
+			types.Int32,
+			types.Int64,
+			types.Uint,
+			types.Uint8,
+			types.Uint16,
+			types.Uint32,
+			types.Uint64,
+			types.Uintptr:
+			return t&argInt != 0
+
+		case types.UntypedFloat,
+			types.Float32,
+			types.Float64:
+			return t&argFloat != 0
+
+		case types.UntypedComplex,
+			types.Complex64,
+			types.Complex128:
+			return t&argComplex != 0
+
+		case types.UntypedString,
+			types.String:
+			return t&argString != 0
+
+		case types.UnsafePointer:
+			return t&(argPointer|argInt) != 0
+
+		case types.UntypedRune:
+			return t&(argInt|argRune) != 0
+
+		case types.UntypedNil:
+			return t&argPointer != 0 // TODO?
+
+		case types.Invalid:
+			if *verbose {
+				f.Warnf(arg.Pos(), "printf argument %v has invalid or unknown type", f.gofmt(arg))
+			}
+			return true // Probably a type check problem.
+		}
+		panic("unreachable")
+	}
+
+	return false
+}
+
+// hasBasicType reports whether x's type is a types.Basic with the given kind.
+func (f *File) hasBasicType(x ast.Expr, kind types.BasicKind) bool {
+	t := f.pkg.types[x].Type
+	if t != nil {
+		t = t.Underlying()
+	}
+	b, ok := t.(*types.Basic)
+	return ok && b.Kind() == kind
+}
+
+// matchStructArgType reports whether all the elements of the struct match the expected
+// type. For instance, with "%d" all the elements must be printable with the "%d" format.
+func (f *File) matchStructArgType(t printfArgType, typ *types.Struct, arg ast.Expr, inProgress map[types.Type]bool) bool {
+	for i := 0; i < typ.NumFields(); i++ {
+		if !f.matchArgTypeInternal(t, typ.Field(i).Type(), arg, inProgress) {
+			return false
+		}
+	}
+	return true
+}
+
+// hasMethod reports whether the type contains a method with the given name.
+// It is part of the workaround for Formatters and should be deleted when
+// that workaround is no longer necessary.
+// TODO: This could be better once issue 6259 is fixed.
+func (f *File) hasMethod(typ types.Type, name string) bool {
+	// assume we have an addressable variable of type typ
+	obj, _, _ := types.LookupFieldOrMethod(typ, true, f.pkg.typesPkg, name)
+	_, ok := obj.(*types.Func)
+	return ok
+}

tools/vendor/github.com/dnephin/govet/unsafeptr.go

@@ -0,0 +1,97 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Check for invalid uintptr -> unsafe.Pointer conversions.
+
+package main
+
+import (
+	"go/ast"
+	"go/token"
+	"go/types"
+)
+
+func init() {
+	register("unsafeptr",
+		"check for misuse of unsafe.Pointer",
+		checkUnsafePointer,
+		callExpr)
+}
+
+func checkUnsafePointer(f *File, node ast.Node) {
+	x := node.(*ast.CallExpr)
+	if len(x.Args) != 1 {
+		return
+	}
+	if f.hasBasicType(x.Fun, types.UnsafePointer) && f.hasBasicType(x.Args[0], types.Uintptr) && !f.isSafeUintptr(x.Args[0]) {
+		f.Badf(x.Pos(), "possible misuse of unsafe.Pointer")
+	}
+}
+
+// isSafeUintptr reports whether x - already known to be a uintptr -
+// is safe to convert to unsafe.Pointer. It is safe if x is itself derived
+// directly from an unsafe.Pointer via conversion and pointer arithmetic
+// or if x is the result of reflect.Value.Pointer or reflect.Value.UnsafeAddr
+// or obtained from the Data field of a *reflect.SliceHeader or *reflect.StringHeader.
+func (f *File) isSafeUintptr(x ast.Expr) bool {
+	switch x := x.(type) {
+	case *ast.ParenExpr:
+		return f.isSafeUintptr(x.X)
+
+	case *ast.SelectorExpr:
+		switch x.Sel.Name {
+		case "Data":
+			// reflect.SliceHeader and reflect.StringHeader are okay,
+			// but only if they are pointing at a real slice or string.
+			// It's not okay to do:
+			//	var x SliceHeader
+			//	x.Data = uintptr(unsafe.Pointer(...))
+			//	... use x ...
+			//	p := unsafe.Pointer(x.Data)
+			// because in the middle the garbage collector doesn't
+			// see x.Data as a pointer and so x.Data may be dangling
+			// by the time we get to the conversion at the end.
+			// For now approximate by saying that *Header is okay
+			// but Header is not.
+			pt, ok := f.pkg.types[x.X].Type.(*types.Pointer)
+			if ok {
+				t, ok := pt.Elem().(*types.Named)
+				if ok && t.Obj().Pkg().Path() == "reflect" {
+					switch t.Obj().Name() {
+					case "StringHeader", "SliceHeader":
+						return true
+					}
+				}
+			}
+		}
+
+	case *ast.CallExpr:
+		switch len(x.Args) {
+		case 0:
+			// maybe call to reflect.Value.Pointer or reflect.Value.UnsafeAddr.
+			sel, ok := x.Fun.(*ast.SelectorExpr)
+			if !ok {
+				break
+			}
+			switch sel.Sel.Name {
+			case "Pointer", "UnsafeAddr":
+				t, ok := f.pkg.types[sel.X].Type.(*types.Named)
+				if ok && t.Obj().Pkg().Path() == "reflect" && t.Obj().Name() == "Value" {
+					return true
+				}
+			}
+
+		case 1:
+			// maybe conversion of uintptr to unsafe.Pointer
+			return f.hasBasicType(x.Fun, types.Uintptr) && f.hasBasicType(x.Args[0], types.UnsafePointer)
+		}
+
+	case *ast.BinaryExpr:
+		switch x.Op {
+		case token.ADD, token.SUB:
+			return f.isSafeUintptr(x.X) && !f.isSafeUintptr(x.Y)
+		}
+	}
+	return false
+}

tools/vendor/github.com/dnephin/govet/unused.go

@@ -0,0 +1,93 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file defines the check for unused results of calls to certain
+// pure functions.
+
+package main
+
+import (
+	"flag"
+	"go/ast"
+	"go/token"
+	"go/types"
+	"strings"
+)
+
+var unusedFuncsFlag = flag.String("unusedfuncs",
+	"errors.New,fmt.Errorf,fmt.Sprintf,fmt.Sprint,sort.Reverse",
+	"comma-separated list of functions whose results must be used")
+
+var unusedStringMethodsFlag = flag.String("unusedstringmethods",
+	"Error,String",
+	"comma-separated list of names of methods of type func() string whose results must be used")
+
+func init() {
+	register("unusedresult",
+		"check for unused result of calls to functions in -unusedfuncs list and methods in -unusedstringmethods list",
+		checkUnusedResult,
+		exprStmt)
+}
+
+// func() string
+var sigNoArgsStringResult = types.NewSignature(nil, nil,
+	types.NewTuple(types.NewVar(token.NoPos, nil, "", types.Typ[types.String])),
+	false)
+
+var unusedFuncs = make(map[string]bool)
+var unusedStringMethods = make(map[string]bool)
+
+func initUnusedFlags() {
+	commaSplit := func(s string, m map[string]bool) {
+		if s != "" {
+			for _, name := range strings.Split(s, ",") {
+				if len(name) == 0 {
+					flag.Usage()
+				}
+				m[name] = true
+			}
+		}
+	}
+	commaSplit(*unusedFuncsFlag, unusedFuncs)
+	commaSplit(*unusedStringMethodsFlag, unusedStringMethods)
+}
+
+func checkUnusedResult(f *File, n ast.Node) {
+	call, ok := unparen(n.(*ast.ExprStmt).X).(*ast.CallExpr)
+	if !ok {
+		return // not a call statement
+	}
+	fun := unparen(call.Fun)
+
+	if f.pkg.types[fun].IsType() {
+		return // a conversion, not a call
+	}
+
+	selector, ok := fun.(*ast.SelectorExpr)
+	if !ok {
+		return // neither a method call nor a qualified ident
+	}
+
+	sel, ok := f.pkg.selectors[selector]
+	if ok && sel.Kind() == types.MethodVal {
+		// method (e.g. foo.String())
+		obj := sel.Obj().(*types.Func)
+		sig := sel.Type().(*types.Signature)
+		if types.Identical(sig, sigNoArgsStringResult) {
+			if unusedStringMethods[obj.Name()] {
+				f.Badf(call.Lparen, "result of (%s).%s call not used",
+					sig.Recv().Type(), obj.Name())
+			}
+		}
+	} else if !ok {
+		// package-qualified function (e.g. fmt.Errorf)
+		obj, _ := f.pkg.uses[selector.Sel]
+		if obj, ok := obj.(*types.Func); ok {
+			qname := obj.Pkg().Path() + "." + obj.Name()
+			if unusedFuncs[qname] {
+				f.Badf(call.Lparen, "result of %v call not used", qname)
+			}
+		}
+	}
+}

tools/vendor/github.com/gordonklaus/ineffassign/ineffassign.go

@@ -12,26 +12,36 @@ import (
 	"strings"
 )
 
-var (
-	root            string
-	dontRecurseFlag = flag.Bool("n", false, "don't recursively check paths")
-)
+const invalidArgumentExitCode = 3
+
+var dontRecurseFlag = flag.Bool("n", false, "don't recursively check paths")
 
 func main() {
 	flag.Parse()
-	if len(flag.Args()) != 1 {
+
+	if len(flag.Args()) == 0 {
 		fmt.Println("missing argument: filepath")
-		return
+		os.Exit(invalidArgumentExitCode)
 	}
 
-	var err error
-	root, err = filepath.Abs(flag.Arg(0))
-	if err != nil {
-		fmt.Printf("Error finding absolute path :%s", err)
-		return
+	lintFailed := false
+	for _, path := range flag.Args() {
+		root, err := filepath.Abs(path)
+		if err != nil {
+			fmt.Printf("Error finding absolute path: %s", err)
+			os.Exit(invalidArgumentExitCode)
+		}
+		if walkPath(root) {
+			lintFailed = true
+		}
 	}
+	if lintFailed {
+		os.Exit(1)
+	}
+}
 
-	errors := false
+func walkPath(root string) bool {
+	lintFailed := false
 	filepath.Walk(root, func(path string, fi os.FileInfo, err error) error {
 		if err != nil {
 			fmt.Printf("Error during filesystem walk: %v\n", err)
@@ -51,13 +61,11 @@ func main() {
 		fset, _, ineff := checkPath(path)
 		for _, id := range ineff {
 			fmt.Printf("%s: ineffectual assignment to %s\n", fset.Position(id.Pos()), id.Name)
-			errors = true
+			lintFailed = true
 		}
 		return nil
 	})
-	if errors {
-		os.Exit(1)
-	}
+	return lintFailed
 }
 
 func checkPath(path string) (*token.FileSet, []*ast.CommentGroup, []*ast.Ident) {
@@ -223,15 +231,24 @@ func (bld *builder) Visit(n ast.Node) ast.Visitor {
 		}
 
 	case *ast.AssignStmt:
+		if n.Tok == token.QUO_ASSIGN || n.Tok == token.REM_ASSIGN {
+			bld.maybePanic()
+		}
+
 		for _, x := range n.Rhs {
 			bld.walk(x)
 		}
-		for _, x := range n.Lhs {
+		for i, x := range n.Lhs {
 			if id, ok := ident(x); ok {
 				if n.Tok >= token.ADD_ASSIGN && n.Tok <= token.AND_NOT_ASSIGN {
 					bld.use(id)
 				}
-				bld.assign(id)
+				// Don't treat explicit initialization to zero as assignment; it is often used as shorthand for a bare declaration.
+				if n.Tok == token.DEFINE && i < len(n.Rhs) && isZeroLiteral(n.Rhs[i]) {
+					bld.use(id)
+				} else {
+					bld.assign(id)
+				}
 			} else {
 				bld.walk(x)
 			}
@@ -277,7 +294,21 @@ func (bld *builder) Visit(n ast.Node) ast.Visitor {
 				bld.use(id)
 			}
 		}
+	case *ast.SendStmt:
+		bld.maybePanic()
+		return bld
 
+	case *ast.BinaryExpr:
+		if n.Op == token.EQL || n.Op == token.QUO || n.Op == token.REM {
+			bld.maybePanic()
+		}
+		return bld
+	case *ast.CallExpr:
+		bld.maybePanic()
+		return bld
+	case *ast.IndexExpr:
+		bld.maybePanic()
+		return bld
 	case *ast.UnaryExpr:
 		id, ok := ident(n.X)
 		if ix, isIx := n.X.(*ast.IndexExpr); isIx {
@@ -291,6 +322,7 @@ func (bld *builder) Visit(n ast.Node) ast.Visitor {
 		}
 		return bld
 	case *ast.SelectorExpr:
+		bld.maybePanic()
 		// A method call (possibly delayed via a method value) might implicitly take
 		// the address of its receiver, causing it to escape.
 		// We can't do any better here without knowing the variable's type.
@@ -301,6 +333,7 @@ func (bld *builder) Visit(n ast.Node) ast.Visitor {
 		}
 		return bld
 	case *ast.SliceExpr:
+		bld.maybePanic()
 		// We don't care about slicing into slices, but without type information we can do no better.
 		if id, ok := ident(n.X); ok {
 			if v, ok := bld.vars[id.Obj]; ok {
@@ -308,6 +341,12 @@ func (bld *builder) Visit(n ast.Node) ast.Visitor {
 			}
 		}
 		return bld
+	case *ast.StarExpr:
+		bld.maybePanic()
+		return bld
+	case *ast.TypeAssertExpr:
+		bld.maybePanic()
+		return bld
 
 	default:
 		return bld
@@ -315,6 +354,18 @@ func (bld *builder) Visit(n ast.Node) ast.Visitor {
 	return nil
 }
 
+func isZeroLiteral(x ast.Expr) bool {
+	b, ok := x.(*ast.BasicLit)
+	if !ok {
+		return false
+	}
+	switch b.Value {
+	case "0", "0.0", "0.", ".0", `""`:
+		return true
+	}
+	return false
+}
+
 func (bld *builder) fun(typ *ast.FuncType, body *ast.BlockStmt) {
 	for _, v := range bld.vars {
 		v.fundept++
@@ -382,6 +433,22 @@ func (bld *builder) swtch(stmt ast.Stmt, cases []ast.Stmt) {
 	bld.breaks.pop()
 }
 
+// An operation that might panic marks named function results as used.
+func (bld *builder) maybePanic() {
+	if len(bld.results) == 0 {
+		return
+	}
+	res := bld.results[len(bld.results)-1]
+	if res == nil {
+		return
+	}
+	for _, f := range res.List {
+		for _, id := range f.Names {
+			bld.use(id)
+		}
+	}
+}
+
 func (bld *builder) newBlock(parents ...*block) *block {
 	bld.block = &block{ops: map[*ast.Object][]operation{}}
 	for _, b := range parents {

tools/vendor/github.com/kisielk/errcheck/README.md

@@ -99,7 +99,7 @@ in the importer.
 
 However, you can use errcheck on packages that depend on those which use cgo. In
 order for this to work you need to `go install` the cgo dependencies before running
-errcheck on the dependant packages.
+errcheck on the dependent packages.
 
 See https://github.com/kisielk/errcheck/issues/16 for more details.
 

tools/vendor/github.com/mattn/goveralls/README.md

@@ -40,7 +40,7 @@ Enable Travis-CI on your github repository settings.
 
 For a **public** github repository put below's `.travis.yml`.
 
-```
+```yml
 language: go
 sudo: false
 go:
@@ -48,14 +48,14 @@ go:
 before_install:
   - go get github.com/mattn/goveralls
 script:
-  - $HOME/gopath/bin/goveralls -service=travis-ci
+  - $GOPATH/bin/goveralls -service=travis-ci
 ```
 
 For a **public** github repository, it is not necessary to define your repository key (`COVERALLS_TOKEN`).
 
 For a **private** github repository put below's `.travis.yml`. If you use **travis pro**, you need to specify `-service=travis-pro` instead of `-service=travis-ci`.
 
-```
+```yml
 language: go
 sudo: false
 go:
@@ -63,7 +63,7 @@ go:
 before_install:
   - go get github.com/mattn/goveralls
 script:
-  - $HOME/gopath/bin/goveralls -service=travis-pro
+  - $GOPATH/bin/goveralls -service=travis-pro
 ```
 
 Store your Coveralls API token in `Environment variables`.
@@ -81,7 +81,7 @@ $ travis encrypt COVERALLS_TOKEN=your_token_goes_here --add env.global
 
 travis will add `env` block as following example:
 
-```
+```yml
 env:
   global:
     secure: xxxxxxxxxxxxx

tools/vendor/github.com/mattn/goveralls/gocover.go

@@ -48,14 +48,13 @@ func mergeProfs(pfss [][]*cover.Profile) []*cover.Profile {
 	ret := make([]*cover.Profile, 0, len(head))
 	for i, profile := range head {
 		for _, ps := range rest {
+			// find profiles
 			if len(ps) == 0 {
-				// no test files
 				continue
 			} else if len(ps) < i+1 {
-				log.Fatal("Profile length is different")
-			}
-			if ps[i].FileName != profile.FileName {
-				log.Fatal("Profile FileName is different")
+				continue
+			} else if ps[i].FileName != profile.FileName {
+				continue
 			}
 			profile.Blocks = mergeProfBlocks(profile.Blocks, ps[i].Blocks)
 		}

tools/vendor/github.com/mattn/goveralls/goveralls.go

@@ -45,6 +45,7 @@ var (
 	extraFlags Flags
 	pkg        = flag.String("package", "", "Go package")
 	verbose    = flag.Bool("v", false, "Pass '-v' argument to 'go test' and output to stdout")
+	race       = flag.Bool("race", false, "Pass '-race' argument to 'go test'")
 	debug      = flag.Bool("debug", false, "Enable debug output")
 	coverprof  = flag.String("coverprofile", "", "If supplied, use a go cover profile (comma separated)")
 	covermode  = flag.String("covermode", "count", "sent as covermode argument to go test")
@@ -132,12 +133,18 @@ func getCoverage() ([]*SourceFile, error) {
 		outBuf := new(bytes.Buffer)
 		cmd.Stdout = outBuf
 		cmd.Stderr = outBuf
-
-		args := []string{"go", "test", "-covermode", *covermode, "-coverprofile", f.Name(), coverpkg}
+		coverm := *covermode
+		if *race {
+			coverm = "atomic"
+		}
+		args := []string{"go", "test", "-covermode", coverm, "-coverprofile", f.Name(), coverpkg}
 		if *verbose {
 			args = append(args, "-v")
 			cmd.Stdout = os.Stdout
 		}
+		if *race {
+			args = append(args, "-race")
+		}
 		args = append(args, extraFlags...)
 		args = append(args, line)
 		cmd.Args = args

tools/vendor/github.com/mdempsky/maligned/LICENSE

@@ -0,0 +1,27 @@
+Copyright (c) 2012 The Go Authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+   * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

tools/vendor/github.com/mdempsky/maligned/README

@@ -0,0 +1,7 @@
+Install:
+
+    go get github.com/mdempsky/maligned
+
+Usage:
+
+    maligned cmd/compile/internal/gc cmd/link/internal/ld

tools/vendor/github.com/mdempsky/maligned/maligned.go

@@ -0,0 +1,229 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"flag"
+	"fmt"
+	"go/ast"
+	"go/build"
+	"go/token"
+	"go/types"
+	"log"
+	"sort"
+
+	"github.com/kisielk/gotool"
+	"golang.org/x/tools/go/loader"
+)
+
+var fset = token.NewFileSet()
+
+func main() {
+	flag.Parse()
+
+	importPaths := gotool.ImportPaths(flag.Args())
+	if len(importPaths) == 0 {
+		return
+	}
+
+	var conf loader.Config
+	conf.Fset = fset
+	for _, importPath := range importPaths {
+		conf.Import(importPath)
+	}
+	prog, err := conf.Load()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	for _, pkg := range prog.InitialPackages() {
+		for _, file := range pkg.Files {
+			ast.Inspect(file, func(node ast.Node) bool {
+				if s, ok := node.(*ast.StructType); ok {
+					malign(node.Pos(), pkg.Types[s].Type.(*types.Struct))
+				}
+				return true
+			})
+		}
+	}
+}
+
+func malign(pos token.Pos, str *types.Struct) {
+	wordSize := int64(8)
+	maxAlign := int64(8)
+	switch build.Default.GOARCH {
+	case "386", "arm":
+		wordSize, maxAlign = 4, 4
+	case "amd64p32":
+		wordSize = 4
+	}
+
+	s := gcSizes{wordSize, maxAlign}
+	sz, opt := s.Sizeof(str), optimalSize(str, &s)
+	if sz != opt {
+		fmt.Printf("%s: struct of size %d could be %d\n", fset.Position(pos), sz, opt)
+	}
+}
+
+func optimalSize(str *types.Struct, sizes *gcSizes) int64 {
+	nf := str.NumFields()
+	fields := make([]*types.Var, nf)
+	alignofs := make([]int64, nf)
+	sizeofs := make([]int64, nf)
+	for i := 0; i < nf; i++ {
+		fields[i] = str.Field(i)
+		ft := fields[i].Type()
+		alignofs[i] = sizes.Alignof(ft)
+		sizeofs[i] = sizes.Sizeof(ft)
+	}
+	sort.Sort(&byAlignAndSize{fields, alignofs, sizeofs})
+	return sizes.Sizeof(types.NewStruct(fields, nil))
+}
+
+type byAlignAndSize struct {
+	fields   []*types.Var
+	alignofs []int64
+	sizeofs  []int64
+}
+
+func (s *byAlignAndSize) Len() int { return len(s.fields) }
+func (s *byAlignAndSize) Swap(i, j int) {
+	s.fields[i], s.fields[j] = s.fields[j], s.fields[i]
+	s.alignofs[i], s.alignofs[j] = s.alignofs[j], s.alignofs[i]
+	s.sizeofs[i], s.sizeofs[j] = s.sizeofs[j], s.sizeofs[i]
+}
+
+func (s *byAlignAndSize) Less(i, j int) bool {
+	// Place zero sized objects before non-zero sized objects.
+	if s.sizeofs[i] == 0 && s.sizeofs[j] != 0 {
+		return true
+	}
+	if s.sizeofs[j] == 0 && s.sizeofs[i] != 0 {
+		return false
+	}
+
+	// Next, place more tightly aligned objects before less tightly aligned objects.
+	if s.alignofs[i] != s.alignofs[j] {
+		return s.alignofs[i] > s.alignofs[j]
+	}
+
+	// Lastly, order by size.
+	if s.sizeofs[i] != s.sizeofs[j] {
+		return s.sizeofs[i] > s.sizeofs[j]
+	}
+
+	return false
+}
+
+// Code below based on go/types.StdSizes.
+
+type gcSizes struct {
+	WordSize int64
+	MaxAlign int64
+}
+
+func (s *gcSizes) Alignof(T types.Type) int64 {
+	// NOTE: On amd64, complex64 is 8 byte aligned,
+	// even though float32 is only 4 byte aligned.
+
+	// For arrays and structs, alignment is defined in terms
+	// of alignment of the elements and fields, respectively.
+	switch t := T.Underlying().(type) {
+	case *types.Array:
+		// spec: "For a variable x of array type: unsafe.Alignof(x)
+		// is the same as unsafe.Alignof(x[0]), but at least 1."
+		return s.Alignof(t.Elem())
+	case *types.Struct:
+		// spec: "For a variable x of struct type: unsafe.Alignof(x)
+		// is the largest of the values unsafe.Alignof(x.f) for each
+		// field f of x, but at least 1."
+		max := int64(1)
+		for i, nf := 0, t.NumFields(); i < nf; i++ {
+			if a := s.Alignof(t.Field(i).Type()); a > max {
+				max = a
+			}
+		}
+		return max
+	}
+	a := s.Sizeof(T) // may be 0
+	// spec: "For a variable x of any type: unsafe.Alignof(x) is at least 1."
+	if a < 1 {
+		return 1
+	}
+	if a > s.MaxAlign {
+		return s.MaxAlign
+	}
+	return a
+}
+
+var basicSizes = [...]byte{
+	types.Bool:       1,
+	types.Int8:       1,
+	types.Int16:      2,
+	types.Int32:      4,
+	types.Int64:      8,
+	types.Uint8:      1,
+	types.Uint16:     2,
+	types.Uint32:     4,
+	types.Uint64:     8,
+	types.Float32:    4,
+	types.Float64:    8,
+	types.Complex64:  8,
+	types.Complex128: 16,
+}
+
+func (s *gcSizes) Sizeof(T types.Type) int64 {
+	switch t := T.Underlying().(type) {
+	case *types.Basic:
+		k := t.Kind()
+		if int(k) < len(basicSizes) {
+			if s := basicSizes[k]; s > 0 {
+				return int64(s)
+			}
+		}
+		if k == types.String {
+			return s.WordSize * 2
+		}
+	case *types.Array:
+		n := t.Len()
+		if n == 0 {
+			return 0
+		}
+		a := s.Alignof(t.Elem())
+		z := s.Sizeof(t.Elem())
+		return align(z, a)*(n-1) + z
+	case *types.Slice:
+		return s.WordSize * 3
+	case *types.Struct:
+		nf := t.NumFields()
+		if nf == 0 {
+			return 0
+		}
+
+		var o int64
+		max := int64(1)
+		for i := 0; i < nf; i++ {
+			ft := t.Field(i).Type()
+			a, sz := s.Alignof(ft), s.Sizeof(ft)
+			if a > max {
+				max = a
+			}
+			if i == nf-1 && sz == 0 && o != 0 {
+				sz = 1
+			}
+			o = align(o, a) + sz
+		}
+		return align(o, max)
+	case *types.Interface:
+		return s.WordSize * 2
+	}
+	return s.WordSize // catch-all
+}
+
+// align returns the smallest y >= x such that y % a == 0.
+func align(x, a int64) int64 {
+	y := x + a - 1
+	return y - y%a
+}

tools/vendor/github.com/mibk/dupl/main.go

@@ -12,7 +12,7 @@ import (
 	"strings"
 
 	"github.com/mibk/dupl/job"
-	"github.com/mibk/dupl/output"
+	"github.com/mibk/dupl/printer"
 	"github.com/mibk/dupl/syntax"
 )
 
@@ -20,18 +20,18 @@ const defaultThreshold = 15
 
 var (
 	paths     = []string{"."}
-	vendor    = flag.Bool("vendor", false, "check files in vendor directory")
-	verbose   = flag.Bool("verbose", false, "explain what is being done")
-	threshold = flag.Int("threshold", defaultThreshold, "minimum token sequence as a clone")
-	files     = flag.Bool("files", false, "files names from stdin")
+	vendor    = flag.Bool("vendor", false, "")
+	verbose   = flag.Bool("verbose", false, "")
+	threshold = flag.Int("threshold", defaultThreshold, "")
+	files     = flag.Bool("files", false, "")
 
-	html     = flag.Bool("html", false, "html output")
-	plumbing = flag.Bool("plumbing", false, "plumbing output for consumption by scripts or tools")
+	html     = flag.Bool("html", false, "")
+	plumbing = flag.Bool("plumbing", false, "")
 )
 
 const (
 	vendorDirPrefix = "vendor" + string(filepath.Separator)
-	vendorDirInPath = string(filepath.Separator) + "vendor" + string(filepath.Separator)
+	vendorDirInPath = string(filepath.Separator) + vendorDirPrefix
 )
 
 func init() {
@@ -39,43 +39,6 @@ func init() {
 	flag.IntVar(threshold, "t", defaultThreshold, "alias for -threshold")
 }
 
-func usage() {
-	fmt.Fprintln(os.Stderr, `Usage of dupl:
-  dupl [flags] [paths]
-
-Paths:
-  If the given path is a file, dupl will use it regardless of
-  the file extension. If it is a directory it will recursively
-  search for *.go files in that directory.
-
-  If no path is given dupl will recursively search for *.go
-  files in the current directory.
-
-Flags:
-  -files
-    	read file names from stdin one at each line
-  -html
-    	output the results as HTML, including duplicate code fragments
-  -plumbing
-    	plumbing (easy-to-parse) output for consumption by scripts or tools
-  -t, -threshold size
-    	minimum token sequence size as a clone (default 15)
-  -vendor
-    	check files in vendor directory
-  -v, -verbose
-    	explain what is being done
-
-Examples:
-  dupl -t 100
-    	Search clones in the current directory of size at least
-    	100 tokens.
-  dupl $(find app/ -name '*_test.go')
-    	Search for clones in tests in the app directory.
-  find app/ -name '*_test.go' |dupl -files
-    	The same as above.`)
-	os.Exit(2)
-}
-
 func main() {
 	flag.Usage = usage
 	flag.Parse()
@@ -110,7 +73,17 @@ func main() {
 		}
 		close(duplChan)
 	}()
-	printDupls(duplChan)
+
+	newPrinter := printer.NewText
+	if *html {
+		newPrinter = printer.NewHTML
+	} else if *plumbing {
+		newPrinter = printer.NewPlumbing
+	}
+	p := newPrinter(os.Stdout, ioutil.ReadFile)
+	if err := printDupls(p, duplChan); err != nil {
+		log.Fatal(err)
+	}
 }
 
 func filesFeed() chan string {
@@ -120,10 +93,7 @@ func filesFeed() chan string {
 			s := bufio.NewScanner(os.Stdin)
 			for s.Scan() {
 				f := s.Text()
-				if strings.HasPrefix(f, "./") {
-					f = f[2:]
-				}
-				fchan <- f
+				fchan <- strings.TrimPrefix(f, "./")
 			}
 			close(fchan)
 		}()
@@ -160,7 +130,7 @@ func crawlPaths(paths []string) chan string {
 	return fchan
 }
 
-func printDupls(duplChan <-chan syntax.Match) {
+func printDupls(p printer.Printer, duplChan <-chan syntax.Match) error {
 	groups := make(map[string][][]*syntax.Node)
 	for dupl := range duplChan {
 		groups[dupl.Hash] = append(groups[dupl.Hash], dupl.Frags...)
@@ -171,32 +141,18 @@ func printDupls(duplChan <-chan syntax.Match) {
 	}
 	sort.Strings(keys)
 
-	p := getPrinter()
+	if err := p.PrintHeader(); err != nil {
+		return err
+	}
 	for _, k := range keys {
 		uniq := unique(groups[k])
 		if len(uniq) > 1 {
-			if err := p.Print(uniq); err != nil {
-				log.Fatal(err)
+			if err := p.PrintClones(uniq); err != nil {
+				return err
 			}
 		}
 	}
-	p.Finish()
-}
-
-func getPrinter() output.Printer {
-	var fr fileReader
-	if *html {
-		return output.NewHTMLPrinter(os.Stdout, fr)
-	} else if *plumbing {
-		return output.NewPlumbingPrinter(os.Stdout, fr)
-	}
-	return output.NewTextPrinter(os.Stdout, fr)
-}
-
-type fileReader struct{}
-
-func (fileReader) ReadFile(filename string) ([]byte, error) {
-	return ioutil.ReadFile(filename)
+	return p.PrintFooter()
 }
 
 func unique(group [][]*syntax.Node) [][]*syntax.Node {
@@ -217,3 +173,39 @@ func unique(group [][]*syntax.Node) [][]*syntax.Node {
 	}
 	return newGroup
 }
+
+func usage() {
+	fmt.Fprintln(os.Stderr, `Usage: dupl [flags] [paths]
+
+Paths:
+  If the given path is a file, dupl will use it regardless of
+  the file extension. If it is a directory, it will recursively
+  search for *.go files in that directory.
+
+  If no path is given, dupl will recursively search for *.go
+  files in the current directory.
+
+Flags:
+  -files
+    	read file names from stdin one at each line
+  -html
+    	output the results as HTML, including duplicate code fragments
+  -plumbing
+    	plumbing (easy-to-parse) output for consumption by scripts or tools
+  -t, -threshold size
+    	minimum token sequence size as a clone (default 15)
+  -vendor
+    	check files in vendor directory
+  -v, -verbose
+    	explain what is being done
+
+Examples:
+  dupl -t 100
+    	Search clones in the current directory of size at least
+    	100 tokens.
+  dupl $(find app/ -name '*_test.go')
+    	Search for clones in tests in the app directory.
+  find app/ -name '*_test.go' |dupl -files
+    	The same as above.`)
+	os.Exit(2)
+}

tools/vendor/github.com/mibk/dupl/printer/html.go

@@ -0,0 +1,120 @@
+package printer
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"regexp"
+	"sort"
+
+	"github.com/mibk/dupl/syntax"
+)
+
+type html struct {
+	iota int
+	w    io.Writer
+	ReadFile
+}
+
+func NewHTML(w io.Writer, fread ReadFile) Printer {
+	return &html{w: w, ReadFile: fread}
+}
+
+func (p *html) PrintHeader() error {
+	_, err := fmt.Fprint(p.w, `<!DOCTYPE html>
+<meta charset="utf-8"/>
+<title>Duplicates</title>
+<style>
+	pre {
+		background-color: #FFD;
+		border: 1px solid #E2E2E2;
+		padding: 1ex;
+	}
+</style>
+`)
+	return err
+}
+
+func (p *html) PrintClones(dups [][]*syntax.Node) error {
+	p.iota++
+	fmt.Fprintf(p.w, "<h1>#%d found %d clones</h1>\n", p.iota, len(dups))
+
+	clones := make([]clone, len(dups))
+	for i, dup := range dups {
+		cnt := len(dup)
+		if cnt == 0 {
+			panic("zero length dup")
+		}
+		nstart := dup[0]
+		nend := dup[cnt-1]
+
+		file, err := p.ReadFile(nstart.Filename)
+		if err != nil {
+			return err
+		}
+
+		lineStart, _ := blockLines(file, nstart.Pos, nend.End)
+		cl := clone{filename: nstart.Filename, lineStart: lineStart}
+		start := findLineBeg(file, nstart.Pos)
+		content := append(toWhitespace(file[start:nstart.Pos]), file[nstart.Pos:nend.End]...)
+		cl.fragment = deindent(content)
+		clones[i] = cl
+	}
+
+	sort.Sort(byNameAndLine(clones))
+	for _, cl := range clones {
+		fmt.Fprintf(p.w, "<h2>%s:%d</h2>\n<pre>%s</pre>\n", cl.filename, cl.lineStart, cl.fragment)
+	}
+	return nil
+}
+
+func (*html) PrintFooter() error { return nil }
+
+func findLineBeg(file []byte, index int) int {
+	for i := index; i >= 0; i-- {
+		if file[i] == '\n' {
+			return i + 1
+		}
+	}
+	return 0
+}
+
+func toWhitespace(str []byte) []byte {
+	var out []byte
+	for _, c := range bytes.Runes(str) {
+		if c == '\t' {
+			out = append(out, '\t')
+		} else {
+			out = append(out, ' ')
+		}
+	}
+	return out
+}
+
+func deindent(block []byte) []byte {
+	const maxVal = 99
+	min := maxVal
+	re := regexp.MustCompile(`(^|\n)(\t*)\S`)
+	for _, line := range re.FindAllSubmatch(block, -1) {
+		indent := line[2]
+		if len(indent) < min {
+			min = len(indent)
+		}
+	}
+	if min == 0 || min == maxVal {
+		return block
+	}
+	block = block[min:]
+Loop:
+	for i := 0; i < len(block); i++ {
+		if block[i] == '\n' && i != len(block)-1 {
+			for j := 0; j < min; j++ {
+				if block[i+j+1] != '\t' {
+					continue Loop
+				}
+			}
+			block = append(block[:i+1], block[i+1+min:]...)
+		}
+	}
+	return block
+}

tools/vendor/github.com/mibk/dupl/printer/plumbing.go

@@ -0,0 +1,36 @@
+package printer
+
+import (
+	"fmt"
+	"io"
+	"sort"
+
+	"github.com/mibk/dupl/syntax"
+)
+
+type plumbing struct {
+	w io.Writer
+	ReadFile
+}
+
+func NewPlumbing(w io.Writer, fread ReadFile) Printer {
+	return &plumbing{w, fread}
+}
+
+func (p *plumbing) PrintHeader() error { return nil }
+
+func (p *plumbing) PrintClones(dups [][]*syntax.Node) error {
+	clones, err := prepareClonesInfo(p.ReadFile, dups)
+	if err != nil {
+		return err
+	}
+	sort.Sort(byNameAndLine(clones))
+	for i, cl := range clones {
+		nextCl := clones[(i+1)%len(clones)]
+		fmt.Fprintf(p.w, "%s:%d-%d: duplicate of %s:%d-%d\n", cl.filename, cl.lineStart, cl.lineEnd,
+			nextCl.filename, nextCl.lineStart, nextCl.lineEnd)
+	}
+	return nil
+}
+
+func (p *plumbing) PrintFooter() error { return nil }

tools/vendor/github.com/mibk/dupl/printer/printer.go

@@ -0,0 +1,11 @@
+package printer
+
+import "github.com/mibk/dupl/syntax"
+
+type ReadFile func(filename string) ([]byte, error)
+
+type Printer interface {
+	PrintHeader() error
+	PrintClones(dups [][]*syntax.Node) error
+	PrintFooter() error
+}

tools/vendor/github.com/mibk/dupl/printer/text.go

@@ -0,0 +1,100 @@
+package printer
+
+import (
+	"fmt"
+	"io"
+	"sort"
+
+	"github.com/mibk/dupl/syntax"
+)
+
+type text struct {
+	cnt int
+	w   io.Writer
+	ReadFile
+}
+
+func NewText(w io.Writer, fread ReadFile) Printer {
+	return &text{w: w, ReadFile: fread}
+}
+
+func (p *text) PrintHeader() error { return nil }
+
+func (p *text) PrintClones(dups [][]*syntax.Node) error {
+	p.cnt++
+	fmt.Fprintf(p.w, "found %d clones:\n", len(dups))
+	clones, err := prepareClonesInfo(p.ReadFile, dups)
+	if err != nil {
+		return err
+	}
+	sort.Sort(byNameAndLine(clones))
+	for _, cl := range clones {
+		fmt.Fprintf(p.w, "  %s:%d,%d\n", cl.filename, cl.lineStart, cl.lineEnd)
+	}
+	return nil
+}
+
+func (p *text) PrintFooter() error {
+	_, err := fmt.Fprintf(p.w, "\nFound total %d clone groups.\n", p.cnt)
+	return err
+}
+
+func prepareClonesInfo(fread ReadFile, dups [][]*syntax.Node) ([]clone, error) {
+	clones := make([]clone, len(dups))
+	for i, dup := range dups {
+		cnt := len(dup)
+		if cnt == 0 {
+			panic("zero length dup")
+		}
+		nstart := dup[0]
+		nend := dup[cnt-1]
+
+		file, err := fread(nstart.Filename)
+		if err != nil {
+			return nil, err
+		}
+
+		cl := clone{filename: nstart.Filename}
+		cl.lineStart, cl.lineEnd = blockLines(file, nstart.Pos, nend.End)
+		clones[i] = cl
+	}
+	return clones, nil
+}
+
+func blockLines(file []byte, from, to int) (int, int) {
+	line := 1
+	lineStart, lineEnd := 0, 0
+	for offset, b := range file {
+		if b == '\n' {
+			line++
+		}
+		if offset == from {
+			lineStart = line
+		}
+		if offset == to-1 {
+			lineEnd = line
+			break
+		}
+	}
+	return lineStart, lineEnd
+}
+
+type clone struct {
+	filename  string
+	lineStart int
+	lineEnd   int
+	fragment  []byte
+}
+
+type byNameAndLine []clone
+
+func (c byNameAndLine) Len() int { return len(c) }
+
+func (c byNameAndLine) Swap(i, j int) { c[i], c[j] = c[j], c[i] }
+
+func (c byNameAndLine) Less(i, j int) bool {
+	if c[i].filename == c[j].filename {
+		return c[i].lineStart < c[j].lineStart
+	}
+	return c[i].filename < c[j].filename
+}

tools/vendor/github.com/mvdan/unparam/check/check.go

@@ -12,7 +12,6 @@ import (
 	"go/parser"
 	"go/token"
 	"go/types"
-	"io"
 	"os"
 	"path/filepath"
 	"regexp"
@@ -29,19 +28,15 @@ import (
 	"github.com/mvdan/lint"
 )
 
-func UnusedParams(tests, debug bool, args ...string) ([]string, error) {
+func UnusedParams(tests bool, args ...string) ([]string, error) {
 	wd, err := os.Getwd()
 	if err != nil {
 		return nil, err
 	}
 	c := &Checker{
-		wd:               wd,
-		tests:            tests,
+		wd: wd, tests: tests,
 		cachedDeclCounts: make(map[string]map[string]int),
 	}
-	if debug {
-		c.debugLog = os.Stderr
-	}
 	return c.lines(args...)
 }
 
@@ -51,8 +46,7 @@ type Checker struct {
 
 	wd string
 
-	tests    bool
-	debugLog io.Writer
+	tests bool
 
 	cachedDeclCounts map[string]map[string]int
 }
@@ -107,12 +101,6 @@ func (c *Checker) ProgramSSA(prog *ssa.Program) {
 	c.prog = prog
 }
 
-func (c *Checker) debug(format string, a ...interface{}) {
-	if c.debugLog != nil {
-		fmt.Fprintf(c.debugLog, format, a...)
-	}
-}
-
 func (c *Checker) Check() ([]lint.Issue, error) {
 	wantPkg := make(map[*types.Package]*loader.PackageInfo)
 	for _, info := range c.lprog.InitialPackages() {
@@ -133,9 +121,7 @@ funcLoop:
 		if info == nil { // not part of given pkgs
 			continue
 		}
-		c.debug("func %s\n", fn.String())
 		if dummyImpl(fn.Blocks[0]) { // panic implementation
-			c.debug("  skip - dummy implementation\n")
 			continue
 		}
 		for _, edge := range cg.Nodes[fn].In {
@@ -144,29 +130,24 @@ funcLoop:
 			default:
 				// called via a parameter or field, type
 				// is set in stone.
-				c.debug("  skip - type is required via call\n")
 				continue funcLoop
 			}
 		}
 		if c.multipleImpls(info, fn) {
-			c.debug("  skip - multiple implementations via build tags\n")
 			continue
 		}
 		for i, par := range fn.Params {
 			if i == 0 && fn.Signature.Recv() != nil { // receiver
 				continue
 			}
-			c.debug("%s\n", par.String())
 			switch par.Object().Name() {
 			case "", "_": // unnamed
-				c.debug("  skip - unnamed\n")
 				continue
 			}
 			reason := "is unused"
 			if cv := receivesSameValue(cg.Nodes[fn].In, par, i); cv != nil {
 				reason = fmt.Sprintf("always receives %v", cv)
 			} else if anyRealUse(par, i) {
-				c.debug("  skip - used somewhere in the func body\n")
 				continue
 			}
 			issues = append(issues, Issue{
@@ -177,25 +158,15 @@ funcLoop:
 
 	}
 	// TODO: replace by sort.Slice once we drop Go 1.7 support
-	sort.Sort(byNamePos{c.prog.Fset, issues})
+	sort.Sort(byPos(issues))
 	return issues, nil
 }
 
-type byNamePos struct {
-	fset *token.FileSet
-	l    []lint.Issue
-}
+type byPos []lint.Issue
 
-func (p byNamePos) Len() int      { return len(p.l) }
-func (p byNamePos) Swap(i, j int) { p.l[i], p.l[j] = p.l[j], p.l[i] }
-func (p byNamePos) Less(i, j int) bool {
-	p1 := p.fset.Position(p.l[i].Pos())
-	p2 := p.fset.Position(p.l[j].Pos())
-	if p1.Filename == p2.Filename {
-		return p1.Offset < p2.Offset
-	}
-	return p1.Filename < p2.Filename
-}
+func (p byPos) Len() int           { return len(p) }
+func (p byPos) Swap(i, j int)      { p[i], p[j] = p[j], p[i] }
+func (p byPos) Less(i, j int) bool { return p[i].Pos() < p[j].Pos() }
 
 func receivesSameValue(in []*callgraph.Edge, par *ssa.Parameter, pos int) constant.Value {
 	if ast.IsExported(par.Parent().Name()) {
@@ -221,47 +192,27 @@ func receivesSameValue(in []*callgraph.Edge, par *ssa.Parameter, pos int) consta
 func anyRealUse(par *ssa.Parameter, pos int) bool {
 refLoop:
 	for _, ref := range *par.Referrers() {
-		switch x := ref.(type) {
-		case *ssa.Call:
-			if x.Call.Value != par.Parent() {
-				return true // not a recursive call
-			}
-			for i, arg := range x.Call.Args {
-				if arg != par {
-					continue
-				}
-				if i == pos {
-					// reused directly in a recursive call
-					continue refLoop
-				}
-			}
-			return true
-		case *ssa.Store:
-			if insertedStore(x) {
-				continue // inserted by go/ssa, not from the code
-			}
-			return true
-		default:
+		call, ok := ref.(*ssa.Call)
+		if !ok {
 			return true
 		}
+		if call.Call.Value != par.Parent() {
+			return true // not a recursive call
+		}
+		for i, arg := range call.Call.Args {
+			if arg != par {
+				continue
+			}
+			if i == pos {
+				// reused directly in a recursive call
+				continue refLoop
+			}
+		}
+		return true
 	}
 	return false
 }
 
-func insertedStore(instr ssa.Instruction) bool {
-	if instr.Pos() != token.NoPos {
-		return false
-	}
-	store, ok := instr.(*ssa.Store)
-	if !ok {
-		return false
-	}
-	alloc, ok := store.Addr.(*ssa.Alloc)
-	// we want exactly one use of this alloc value for it to be
-	// inserted by ssa and dummy - the alloc instruction itself.
-	return ok && len(*alloc.Referrers()) == 1
-}
-
 var rxHarmlessCall = regexp.MustCompile(`(?i)\b(log(ger)?|errors)\b|\bf?print`)
 
 // dummyImpl reports whether a block is a dummy implementation. This is
@@ -270,15 +221,11 @@ var rxHarmlessCall = regexp.MustCompile(`(?i)\b(log(ger)?|errors)\b|\bf?print`)
 func dummyImpl(blk *ssa.BasicBlock) bool {
 	var ops [8]*ssa.Value
 	for _, instr := range blk.Instrs {
-		if insertedStore(instr) {
-			continue // inserted by go/ssa, not from the code
-		}
 		for _, val := range instr.Operands(ops[:0]) {
 			switch x := (*val).(type) {
 			case nil, *ssa.Const, *ssa.ChangeType, *ssa.Alloc,
 				*ssa.MakeInterface, *ssa.Function,
-				*ssa.Global, *ssa.IndexAddr, *ssa.Slice,
-				*ssa.UnOp:
+				*ssa.Global, *ssa.IndexAddr, *ssa.Slice:
 			case *ssa.Call:
 				if rxHarmlessCall.MatchString(x.Call.Value.String()) {
 					continue

tools/vendor/github.com/mvdan/unparam/main.go

@@ -11,18 +11,11 @@ import (
 	"github.com/mvdan/unparam/check"
 )
 
-var (
-	tests = flag.Bool("tests", true, "include tests")
-	debug = flag.Bool("debug", false, "debug prints")
-)
+var tests = flag.Bool("tests", true, "include tests")
 
 func main() {
-	flag.Usage = func() {
-		fmt.Fprintln(os.Stderr, "usage: unparam [flags] [package ...]")
-		flag.PrintDefaults()
-	}
 	flag.Parse()
-	warns, err := check.UnusedParams(*tests, *debug, flag.Args()...)
+	warns, err := check.UnusedParams(*tests, flag.Args()...)
 	if err != nil {
 		fmt.Fprintln(os.Stderr, err)
 		os.Exit(1)