sqlite/autosetup/sqlite-config.tcl

# This file holds functions for autosetup which are specific to the
# sqlite build tree.  They are in this file, instead of auto.def, so
# that they can be reused in the autoconf sub-tree. This file requires
# functions from proj.tcl.

if {[string first " " $autosetup(srcdir)] != -1} {
  user-error "The pathname of the source tree\
              may not contain space characters"
}
if {[string first " " $autosetup(builddir)] != -1} {
  user-error "The pathname of the build directory\
              may not contain space characters"
}
#parray ::autosetup; exit 0
use proj
#
# We want the package version info to be emitted early on, but doing
# so requires a bit of juggling. We have to [use system] for
# --prefix=... to work and to emit the Host/Build system info, but we
# don't want those to interfere with --help output.
define PACKAGE_VERSION [proj-file-content -trim $::autosetup(srcdir)/VERSION]
if {"--help" ni $::argv} {
  msg-result "Configuring SQLite version [get-define PACKAGE_VERSION]"
}
use system ; # Will output "Host System" and "Build System" lines
if {"--help" ni $::argv} {
  msg-result "Source dir = $::autosetup(srcdir)"
  msg-result "Build dir  = $::autosetup(builddir)"
  use cc cc-db cc-shared cc-lib pkg-config
}

#
# Object for communicating certain config-time state across various
# auto.def-related pieces.
array set sqliteConfig [subst [proj-strip-hash-comments {
  #
  # Gets set by [sqlite-configure] (the main configure script driver).
  build-mode unknown
  #
  # Gets set to 1 when using jimsh for code generation. May affect
  # later decisions.
  use-jim-for-codegen  0
  #
  # Set to 1 when cross-compiling This value may be changed by certain
  # build options, so it's important that config code which checks for
  # cross-compilation uses this var instead of
  # [proj-is-cross-compiling].
  is-cross-compiling [proj-is-cross-compiling]
  #
  # Pass msg-debug=1 to configure to enable obnoxiously loud output
  # from [msg-debug].
  msg-debug-enabled    0
  #
  # Output file for --dump-defines. Intended only for build debugging
  # and not part of the public build interface.
  dump-defines-txt   ./config.defines.txt
  #
  # If not empty then --dump-defines will dump not only
  # (dump-defines-txt) but also a JSON file named after this option's
  # value.
  dump-defines-json  ""
}]]

########################################################################
# Processes all configure --flags for this build, run build-specific
# config checks, then finalize the configure process. $buildMode must
# be one of (canonical, autoconf), and others may be added in the
# future. After bootstrapping, $configScript is eval'd in the caller's
# scope, then post-configuration finalization is run. $configScript is
# intended to hold configure code which is specific to the given
# $buildMode, with the caveat that _some_ build-specific code is
# encapsulated in the configuration finalization step.
#
# The intent is that all (or almost all) build-mode-specific
# configuration goes inside the $configScript argument to this
# function, and that an auto.def file contains only two commands:
#
#  use sqlite-config
#  sqlite-configure BUILD_NAME { build-specific configure script }
#
# There are snippets of build-mode-specific decision-making in
# [sqlite-configure-finalize]
proc sqlite-configure {buildMode configScript} {
  proj-assert {$::sqliteConfig(build-mode) eq "unknown"} \
    "sqlite-configure must not be called more than once"
  set allBuildModes {canonical autoconf tcl-extension}
  if {$buildMode ni $allBuildModes} {
    user-error "Invalid build mode: $buildMode. Expecting one of: $allBuildModes"
  }
  set ::sqliteConfig(build-mode) $buildMode
  ########################################################################
  # A gentle introduction to flags handling in autosetup
  #
  # Reference: https://msteveb.github.io/autosetup/developer/
  #
  # All configure flags must be described in an 'options' call. The
  # general syntax is:
  #
  #  FLAG => {Help text}
  #
  # Where FLAG can have any of the following formats:
  #
  #   boolopt            => "a boolean option which defaults to disabled"
  #   boolopt2=1         => "a boolean option which defaults to enabled"
  #   stringopt:         => "an option which takes an argument, e.g. --stringopt=value"
  #   stringopt:DESCR    => As for stringopt: with a description for the value
  #   stringopt2:=value  => "an option where the argument is optional and defaults to 'value'"
  #   optalias booltopt3 => "a boolean with a hidden alias. --optalias is not shown in --help"
  #
  # Autosetup does no small amount of specialized handling for flags,
  # especially booleans. Each bool-type --FLAG implicitly gets
  # --enable-FLAG and --disable-FLAG forms. That can lead lead to some
  # confusion when writing help text. For example:
  #
  #   options { json=1 {Disable JSON functions} }
  #
  # The reason the help text says "disable" is because a boolean option
  # which defaults to true is, in the --help text, rendered as:
  #
  #   --disable-json          Disable JSON functions
  #
  # Whereas a bool flag which defaults to false will instead render as:
  #
  #   --enable-FLAG
  #
  # Non-boolean flags, in contrast, use the names specifically given to
  # them in the [options] invocation. e.g. "with-tcl" is the --with-tcl
  # flag.
  #
  # Fetching values for flags:
  #
  #   booleans: use one of:
  #     - [opt-bool FLAG] is autosetup's built-in command for this, but we
  #       have some convenience variants:
  #     - [proj-opt-truthy FLAG]
  #     - [proj-opt-if-truthy FLAG {THEN} {ELSE}]
  #
  #   Non-boolean (i.e. string) flags:
  #     - [opt-val FLAG ?default?]
  #     - [opt-str ...] - see the docs in ./autosetup/autosetup
  #
  # [proj-opt-was-provided] can be used to determine whether a flag was
  # explicitly provided, which is often useful for distinguishing from
  # the case of a default value.
  ########################################################################
  set allFlags {
    # Structure: a list of M {Z} pairs, where M is a descriptive
    # option group name  and Z is a list of X Y pairs. X is a list of
    # $buildMode name(s) to which the Y flags apply, or {*} to apply
    # to all builds. Y is a {block} in the form expected by
    # autosetup's [options] command.  Each block which is applicable
    # to $buildMode is appended to a new list before that list is
    # passed on to [options]. The order of each Y and sub-Y is
    # retained, which is significant for rendering of --help.

    # When writing {help text blocks}, be aware that:
    #
    # A) autosetup formats them differently if the {block} starts with
    # a newline: it starts left-aligned, directly under the --flag, and
    # the rest of the block is pasted verbatim rather than
    # pretty-printed.
    #
    # B) Vars and commands are NOT expanded, but we use a [subst] call
    # below which will replace (only) var refs.

    # Options for how to build the library
    build-modes {
      {canonical autoconf} {
        shared=1             => {Disable build of shared library}
        static=1             => {Disable build of static library}
      }
      {canonical} {
        amalgamation=1       => {Disable the amalgamation and instead build all files separately}
      }
    }

    # Library-level features and defaults
    lib-features {
      {*} {
        threadsafe=1         => {Disable mutexing}
        with-tempstore:=no   => {Use an in-RAM database for temporary tables: never,no,yes,always}
        load-extension=1     => {Disable loading of external extensions}
        # ^^^ one of the downstream custom builds overrides the load-extension default to 0, which
        # confuses the --help text generator. https://github.com/msteveb/autosetup/issues/77
        math=1               => {Disable math functions}
        json=1               => {Disable JSON functions}
        memsys5              => {Enable MEMSYS5}
        memsys3              => {Enable MEMSYS3}
        fts3                 => {Enable the FTS3 extension}
        fts4                 => {Enable the FTS4 extension}
        fts5                 => {Enable the FTS5 extension}
        update-limit         => {Enable the UPDATE/DELETE LIMIT clause}
        geopoly              => {Enable the GEOPOLY extension}
        rtree                => {Enable the RTREE extension}
        session              => {Enable the SESSION extension}
        all                  => {Enable FTS4, FTS5, Geopoly, RTree, Sessions}
        largefile=1
          => {This legacy flag has no effect on the library but may influence
              the generated sqlite_cfg.h by adding #define HAVE_LFS}
      }
    }

    # Options for TCL support
    tcl {
      {canonical} {
        tcl=1
          => {Disable components which require TCL, including all tests.
              This tree requires TCL for code generation but can use the in-tree
              copy of autosetup/jimsh0.c for that. The SQLite TCL extension and the
              test code require a canonical tclsh.}
      }
      {canonical tcl-extension} {
        with-tcl:DIR
          => {Directory containing tclConfig.sh or a directory one level up from
              that, from which we can derive a directory containing tclConfig.sh.
              A dir name of "prefix" is equivalent to the directory specified by
              the --prefix flag.}
        with-tclsh:PATH
          => {Full pathname of tclsh to use.  It is used for (A) trying to find
              tclConfig.sh and (B) all TCL-based code generation.  Warning: if
              its containing dir has multiple tclsh versions, it may select the
              wrong tclConfig.sh!}
      }
    }

    # Options for line-editing modes for the CLI shell
    line-editing {
      {canonical autoconf} {
        readline=1
          => {Disable readline support}
        # --with-readline-lib is a backwards-compatible alias for
        # --with-readline-ldflags
        with-readline-lib:
        with-readline-ldflags:=auto
          => {Readline LDFLAGS, e.g. -lreadline -lncurses}
        # --with-readline-inc is a backwards-compatible alias for
        # --with-readline-cflags.
        with-readline-inc:
        with-readline-cflags:=auto
          => {Readline CFLAGS, e.g. -I/path/to/includes}
        with-readline-header:PATH
          => {Full path to readline.h, from which --with-readline-cflags will be derived}
        with-linenoise:DIR
          => {Source directory for linenoise.c and linenoise.h}
        editline=0
          => {Enable BSD editline support}
      }
    }

    # Options for ICU: International Components for Unicode
    icu {
      {*} {
        with-icu-ldflags:LDFLAGS
          => {Enable SQLITE_ENABLE_ICU and add the given linker flags for the
              ICU libraries. e.g. on Ubuntu systems, try '-licui18n -licuuc -licudata'.}
        with-icu-cflags:CFLAGS
          => {Apply extra CFLAGS/CPPFLAGS necessary for building with ICU.
              e.g. -I/usr/local/include}
        with-icu-config:=auto
          => {Enable SQLITE_ENABLE_ICU. Value must be one of: auto, pkg-config,
              /path/to/icu-config}
        icu-collations=0
          => {Enable SQLITE_ENABLE_ICU_COLLATIONS. Requires --with-icu-ldflags=...
              or --with-icu-config}
      }
    }

    # Options for exotic/alternative build modes
    alternative-builds {
      {canonical autoconf} {
        with-wasi-sdk:=/opt/wasi-sdk
          => {Top-most dir of the wasi-sdk for a WASI build}
      }

      {canonical} {
        with-emsdk:=auto
          => {Top-most dir of the Emscripten SDK installation.
              Needed only by ext/wasm. Default=EMSDK env var.}

        amalgamation-extra-src:FILES
          => {Space-separated list of soure files to append as-is to the resulting
              sqlite3.c amalgamation file. May be provided multiple times.}
      }
    }

    # Options primarily for downstream packagers/package maintainers
    packaging {
      {autoconf} {
        # --disable-static-shell: https://sqlite.org/forum/forumpost/cc219ee704
        static-shell=1
          => {Link the sqlite3 shell app against the DLL instead of embedding sqlite3.c}
      }
      {canonical autoconf} {
        # A potential TODO without a current use case:
        #rpath=1 => {Disable use of the rpath linker flag}
        # soname: https://sqlite.org/src/forumpost/5a3b44f510df8ded
        soname:=legacy
          => {SONAME for libsqlite3.so. "none", or not using this flag, sets no
              soname. "legacy" sets it to its historical value of
              libsqlite3.so.0.  A value matching the glob "libsqlite3.*" sets
              it to that literal value. Any other value is assumed to be a
              suffix which gets applied to "libsqlite3.so.",
              e.g. --soname=9.10 equates to "libsqlite3.so.9.10".}
        # dll-basename: https://sqlite.org/forum/forumpost/828fdfe904
        dll-basename:=auto
          => {Specifies the base name of the resulting DLL file.
              If not provided, "libsqlite3" is usually assumed but on some platforms
              a platform-dependent default is used. On some platforms this flag
              gets automatically enabled if it is not provided. Use "default" to
              explicitly disable platform-dependent activation on such systems.}
        # out-implib: https://sqlite.org/forum/forumpost/0c7fc097b2
        out-implib:=auto
          => {Enable use of --out-implib linker flag to generate an
              "import library" for the DLL. The output's base name is
              specified by this flag's value, with "auto" meaning to figure
              out a name automatically. On some platforms this flag gets
              automatically enabled if it is not provided. Use "none" to
              explicitly disable this feature on such platforms.}
      }
    }

    # Options mostly for sqlite's own development
    developer {
      {*} {
        # Note that using the --debug/--enable-debug flag here
        # requires patching autosetup/autosetup to rename its builtin
        # --debug to --autosetup-debug. See details in
        # autosetup/README.md#patching.
        with-debug=0
        debug=0
          => {Enable debug build flags. This option will impact performance by
              as much as 4x, as it includes large numbers of assert()s in
              performance-critical loops.  Never use --debug for production
              builds.}
        scanstatus
          => {Enable the SQLITE_ENABLE_STMT_SCANSTATUS feature flag}
      }
      {canonical} {
        dev
          => {Enable dev-mode build: automatically enables certain other flags}
        test-status
          => {Enable status of tests}
        gcov=0
          => {Enable coverage testing using gcov}
        linemacros
          => {Enable #line macros in the amalgamation}
        dynlink-tools
          => {Dynamically link libsqlite3 to certain tools which normally statically embed it}
        asan-fsanitize:=auto
          => {Comma- or space-separated list of -fsanitize flags for use with the
              fuzzcheck-asan tool. Only those which the compiler claims to support
              will actually be used. May be provided multiple times.}
      }
      {*} {
        dump-defines=0
          => {Dump autosetup defines to $::sqliteConfig(dump-defines-txt)
              (for build debugging)}
      }
    }
  }; # $allFlags

  set allFlags [proj-strip-hash-comments $allFlags]
  # ^^^ lappend of [sqlite-custom-flags] introduces weirdness if
  # we delay [proj-strip-hash-comments] until after that.


  ########################################################################
  # sqlite-custom.tcl is intended only for vendor-branch-specific
  # customization.  See autosetup/README.md#branch-customization for
  # details.
  if {[file exists $::autosetup(libdir)/sqlite-custom.tcl]} {
    uplevel 1 {source $::autosetup(libdir)/sqlite-custom.tcl}
  }

  if {[llength [info proc sqlite-custom-flags]] > 0} {
    # sqlite-custom-flags is assumed to be imported via
    # autosetup/sqlite-custom.tcl.
    set scf [sqlite-custom-flags]
    if {"" ne $scf} {
      lappend allFlags sqlite-custom-flags $scf
    }
  }

  # Filter allFlags to create the set of [options] legal for this build
  set opts {}
  foreach {group XY} [subst -nobackslashes -nocommands \
                        [proj-strip-hash-comments $allFlags]] {
    foreach {X Y} $XY {
      if { $buildMode in $X || "*" in $X } {
        foreach y $Y {
          lappend opts $y
        }
      }
    }
  }
  #lappend opts "soname:=duplicateEntry => {x}"; #just testing
  if {[catch {options $opts} msg xopts]} {
    # Workaround for <https://github.com/msteveb/autosetup/issues/73>
    # where [options] behaves oddly on _some_ TCL builds when it's
    # called from deeper than the global scope.
    dict incr xopts -level
    return {*}$xopts $msg
  }
  sqlite-configure-phase1 $buildMode
  uplevel 1 $configScript
  sqlite-configure-finalize
}; # sqlite-configure

########################################################################
# Runs "phase 1" of the configure process: after initial --flags
# handling but before the build-specific parts are run. $buildMode
# must be the mode which was passed to [sqlite-configure].
proc sqlite-configure-phase1 {buildMode} {
  define PACKAGE_NAME sqlite
  define PACKAGE_URL {https://sqlite.org}
  define PACKAGE_BUGREPORT [get-define PACKAGE_URL]/forum
  define PACKAGE_STRING "[get-define PACKAGE_NAME] [get-define PACKAGE_VERSION]"
  proj-xfer-options-aliases {
    # Carry values from hidden --flag aliases over to their canonical
    # flag forms. This list must include only options which are common
    # to all build modes supported by [sqlite-configure].
    with-readline-inc => with-readline-cflags
    with-readline-lib => with-readline-ldflags
    with-debug => debug
  }
  set ::sqliteConfig(msg-debug-enabled) [proj-val-truthy [get-env msg-debug 0]]
  proc-debug "msg-debug is enabled"
  sqlite-autoreconfig
  proj-file-extensions
  if {".exe" eq [get-define TARGET_EXEEXT]} {
    define SQLITE_OS_UNIX 0
    define SQLITE_OS_WIN 1
  } else {
    define SQLITE_OS_UNIX 1
    define SQLITE_OS_WIN 0
  }
  sqlite-setup-default-cflags
  define HAVE_LFS 0
  if {[opt-bool largefile]} {
    #
    # Insofar as we can determine HAVE_LFS has no effect on the
    # library.  Perhaps it did back in the early 2000's. The
    # --enable/disable-largefile flag is retained because it's
    # harmless, but it doesn't do anything useful. It does have
    # visible side-effects, though: the generated sqlite_cfg.h may (or
    # may not) define HAVE_LFS.
    cc-check-lfs
  }
}; # sqlite-configure-phase1

########################################################################
# Performs late-stage config steps common to all supported
# $::sqliteConfig(build-mode) values.
proc sqlite-configure-finalize {} {
  sqlite-handle-rpath
  sqlite-handle-soname
  sqlite-handle-threadsafe
  sqlite-handle-tempstore
  sqlite-handle-load-extension
  sqlite-handle-math
  sqlite-handle-icu
  if {[proj-opt-exists readline]} {
    sqlite-handle-line-editing
  }
  if {[proj-opt-exists shared]} {
    proj-define-for-opt shared ENABLE_LIB_SHARED "Build shared library?"
  }
  if {[proj-opt-exists static]} {
    if {![proj-define-for-opt static ENABLE_LIB_STATIC "Build static library?"]} {
      # This notice really only applies to the canonical build...
      proj-indented-notice {
        NOTICE: static lib build may be implicitly re-activated by
        other components, e.g. some test apps.
      }
    }
  }
  sqlite-handle-env-quirks
  sqlite-handle-common-feature-flags
  sqlite-finalize-feature-flags
  sqlite-process-dot-in-files; # do not [define] anything after this
  sqlite-post-config-validation
  sqlite-dump-defines
}

########################################################################
# Internal config-time debugging output routine. It generates no
# output unless msg-debug=1 is passed to the configure script.
proc msg-debug {msg} {
  if {$::sqliteConfig(msg-debug-enabled)} {
    puts stderr [proj-bold "** DEBUG: $msg"]
  }
}
########################################################################
# A [msg-debug] proxy which prepends the name of the current proc to
# the debug message. It is not legal to call this from the global
# scope.
proc proc-debug {msg} {
  msg-debug "\[[proj-current-proc-name 1]\]: $msg"
}

########################################################################
# Sets up the SQLITE_AUTORECONFIG define.
proc sqlite-autoreconfig {} {
  # SQLITE_AUTORECONFIG contains make target rules for re-running the
  # configure script with the same arguments it was initially invoked
  # with. This can be used to automatically reconfigure.
  set squote {{arg} {
    # Wrap $arg in single-quotes if it looks like it might need that
    # to avoid mis-handling as a shell argument. We assume that $arg
    # will never contain any single-quote characters.
    if {[string match {*[ &;$*"]*} $arg]} { return '$arg' }
    return $arg
  }}
  define-append SQLITE_AUTORECONFIG cd [apply $squote $::autosetup(builddir)] \
    && [apply $squote $::autosetup(srcdir)/configure]
  #{*}$::autosetup(argv) breaks with --flag='val with spaces', so...
  foreach arg $::autosetup(argv) {
    define-append SQLITE_AUTORECONFIG [apply $squote $arg]
  }
}

define OPT_FEATURE_FLAGS {} ; # -DSQLITE_OMIT/ENABLE flags.
define OPT_SHELL {}         ; # Feature-related CFLAGS for the sqlite3 CLI app
########################################################################
# Adds $args, if not empty, to OPT_FEATURE_FLAGS.  If the first arg is
# -shell then it strips that arg and passes the remaining args the
# sqlite-add-shell-opt in addition to adding them to
# OPT_FEATURE_FLAGS. This is intended only for holding
# -DSQLITE_ENABLE/OMIT/... flags, but that is not enforced here.
proc sqlite-add-feature-flag {args} {
  set shell ""
  if {"-shell" eq [lindex $args 0]} {
    set args [lassign $args shell]
  }
  if {"" ne $args} {
    if {"" ne $shell} {
      sqlite-add-shell-opt {*}$args
    }
    define-append OPT_FEATURE_FLAGS {*}$args
  }
}

########################################################################
# Appends $args, if not empty, to OPT_SHELL.
proc sqlite-add-shell-opt {args} {
  if {"" ne $args} {
    define-append OPT_SHELL {*}$args
  }
}

########################################################################
# Check for log(3) in libm and die with an error if it is not
# found. $featureName should be the feature name which requires that
# function (it's used only in error messages). defines LDFLAGS_MATH to
# the required linker flags (which may be empty even if the math APIs
# are found, depending on the OS).
proc sqlite-affirm-have-math {featureName} {
  if {"" eq [get-define LDFLAGS_MATH ""]} {
    if {![msg-quiet proj-check-function-in-lib log m]} {
      user-error "Missing math APIs for $featureName"
    }
    define LDFLAGS_MATH [get-define lib_log ""]
    undefine lib_log
  }
}

########################################################################
# Run checks for required binaries, like ld and ar. In the canonical
# build this must come before [sqlite-handle-wasi-sdk].
proc sqlite-check-common-bins {} {
  cc-check-tools ld ar ; # must come before [sqlite-handle-wasi-sdk]
  if {"" eq [proj-bin-define install]} {
    proj-warn "Cannot find install binary, so 'make install' will not work."
    define BIN_INSTALL false
  }
}

########################################################################
# Run checks for system-level includes and libs which are common to
# both the canonical build and the "autoconf" bundle.
#
# For the canonical build this must come after
# [sqlite-handle-wasi-sdk], as that function may change the
# environment in ways which affect this.
proc sqlite-check-common-system-deps {} {
  # Check for needed/wanted data types
  cc-with {-includes stdint.h} \
    {cc-check-types int8_t int16_t int32_t int64_t intptr_t \
       uint8_t uint16_t uint32_t uint64_t uintptr_t}

  # Check for needed/wanted functions
  cc-check-functions gmtime_r isnan localtime_r localtime_s \
    malloc_usable_size strchrnul usleep utime pread pread64 pwrite pwrite64

  set ldrt ""
  # Collapse funcs from librt into LDFLAGS_RT.
  # Some systems (ex: SunOS) require -lrt in order to use nanosleep
  foreach func {fdatasync nanosleep} {
    if {[proj-check-function-in-lib $func rt]} {
      lappend ldrt [get-define lib_${func}]
    }
  }
  define LDFLAGS_RT [join [lsort -unique $ldrt] ""]

  # Check for needed/wanted headers
  cc-check-includes \
    sys/types.h sys/stat.h dlfcn.h unistd.h \
    stdlib.h malloc.h memory.h \
    string.h strings.h \
    inttypes.h

  if {[cc-check-includes zlib.h] && [proj-check-function-in-lib deflate z]} {
    # TODO? port over the more sophisticated zlib search from the fossil auto.def
    define HAVE_ZLIB 1
    define LDFLAGS_ZLIB -lz
    sqlite-add-shell-opt -DSQLITE_HAVE_ZLIB=1
  } else {
    define HAVE_ZLIB 0
    define LDFLAGS_ZLIB ""
  }
}

########################################################################
# Move -DSQLITE_OMIT... and -DSQLITE_ENABLE... flags from CFLAGS and
# CPPFLAGS to OPT_FEATURE_FLAGS and remove them from BUILD_CFLAGS.
proc sqlite-munge-cflags {} {
  # Move CFLAGS and CPPFLAGS entries matching -DSQLITE_OMIT* and
  # -DSQLITE_ENABLE* to OPT_FEATURE_FLAGS. This behavior is derived
  # from the legacy build and was missing the 3.48.0 release (the
  # initial Autosetup port).
  # https://sqlite.org/forum/forumpost/9801e54665afd728
  #
  # Handling of CPPFLAGS, as well as removing ENABLE/OMIT from
  # CFLAGS/CPPFLAGS, was missing in the 3.49.0 release as well.
  #
  # If any configure flags for features are in conflict with
  # CFLAGS/CPPFLAGS-specified feature flags, all bets are off.  There
  # are no guarantees about which one will take precedence.
  foreach flagDef {CFLAGS CPPFLAGS} {
    set tmp ""
    foreach cf [get-define $flagDef ""] {
      switch -glob -- $cf {
        -DSQLITE_OMIT* -
        -DSQLITE_ENABLE* {
          sqlite-add-feature-flag $cf
        }
        default {
          lappend tmp $cf
        }
      }
    }
    define $flagDef $tmp
  }

  # Strip all SQLITE_ENABLE/OMIT flags from BUILD_CFLAGS,
  # for compatibility with the legacy build.
  set tmp ""
  foreach cf [get-define BUILD_CFLAGS ""] {
    switch -glob -- $cf {
      -DSQLITE_OMIT* -
      -DSQLITE_ENABLE* {}
      default {
        lappend tmp $cf
      }
    }
  }
  define BUILD_CFLAGS $tmp
}

#########################################################################
# Set up the default CFLAGS and BUILD_CFLAGS values.
proc sqlite-setup-default-cflags {} {
  ########################################################################
  # We differentiate between two C compilers: the one used for binaries
  # which are to run on the build system (in autosetup it's called
  # CC_FOR_BUILD and in Makefile.in it's $(B.cc)) and the one used for
  # compiling binaries for the target system (CC a.k.a. $(T.cc)).
  # Normally they're the same, but they will differ when
  # cross-compiling.
  #
  # When cross-compiling we default to not using the -g flag, based on a
  # /chat discussion prompted by
  # https://sqlite.org/forum/forumpost/9a67df63eda9925c
  set defaultCFlags {-O2}
  if {!$::sqliteConfig(is-cross-compiling)} {
    lappend defaultCFlags -g
  }
  define CFLAGS [proj-get-env CFLAGS $defaultCFlags]
  # BUILD_CFLAGS is the CFLAGS for CC_FOR_BUILD.
  define BUILD_CFLAGS [proj-get-env BUILD_CFLAGS {-g}]
  sqlite-munge-cflags
}

########################################################################
# Handle various SQLITE_ENABLE/OMIT_... feature flags.
proc sqlite-handle-common-feature-flags {} {
  msg-result "Feature flags..."
  foreach {boolFlag featureFlag ifSetEvalThis} {
    all         {} {
      # The 'all' option must be first in this list.
      proj-opt-set fts4
      proj-opt-set fts5
      proj-opt-set geopoly
      proj-opt-set rtree
      proj-opt-set session
    }
    fts4         -DSQLITE_ENABLE_FTS4    {sqlite-affirm-have-math fts4}
    fts5         -DSQLITE_ENABLE_FTS5    {sqlite-affirm-have-math fts5}
    geopoly      -DSQLITE_ENABLE_GEOPOLY {proj-opt-set rtree}
    rtree        -DSQLITE_ENABLE_RTREE   {}
    session      {-DSQLITE_ENABLE_SESSION -DSQLITE_ENABLE_PREUPDATE_HOOK} {}
    update-limit -DSQLITE_ENABLE_UPDATE_DELETE_LIMIT {}
    memsys5      -DSQLITE_ENABLE_MEMSYS5 {}
    memsys3      {} {
      if {[opt-bool memsys5]} {
        proj-warn "not enabling memsys3 because memsys5 is enabled."
        expr 0
      } else {
        sqlite-add-feature-flag -DSQLITE_ENABLE_MEMSYS3
      }
    }
    scanstatus     -DSQLITE_ENABLE_STMT_SCANSTATUS {}
  } {
    if {$boolFlag ni $::autosetup(options)} {
      # Skip flags which are in the canonical build but not
      # the autoconf bundle.
      continue
    }
    proj-if-opt-truthy $boolFlag {
      sqlite-add-feature-flag $featureFlag
      if {0 != [eval $ifSetEvalThis] && "all" ne $boolFlag} {
        msg-result "  + $boolFlag"
      }
    } {
      if {"all" ne $boolFlag} {
        msg-result "  - $boolFlag"
      }
    }
  }
  ########################################################################
  # Invert the above loop's logic for some SQLITE_OMIT_...  cases. If
  # config option $boolFlag is false, [sqlite-add-feature-flag
  # $featureFlag], where $featureFlag is intended to be
  # -DSQLITE_OMIT_...
  foreach {boolFlag featureFlag} {
    json        -DSQLITE_OMIT_JSON
  } {
    if {[proj-opt-truthy $boolFlag]} {
      msg-result "  + $boolFlag"
    } else {
      sqlite-add-feature-flag $featureFlag
      msg-result "  - $boolFlag"
    }
  }
}

#########################################################################
# Remove duplicates from the final feature flag sets and show them to
# the user.
proc sqlite-finalize-feature-flags {} {
  set oFF [get-define OPT_FEATURE_FLAGS]
  if {"" ne $oFF} {
    define OPT_FEATURE_FLAGS [lsort -unique $oFF]
    msg-result "Library feature flags: [get-define OPT_FEATURE_FLAGS]"
  }
  set oFF [get-define OPT_SHELL]
  if {"" ne $oFF} {
    define OPT_SHELL [lsort -unique $oFF]
    msg-result "Shell options: [get-define OPT_SHELL]"
  }
  if {"" ne [set extraSrc [get-define AMALGAMATION_EXTRA_SRC ""]]} {
    proj-assert {"canonical" eq $::sqliteConfig(build-mode)}
    msg-result "Appending source files to amalgamation: $extraSrc"
  }
  if {[lsearch [get-define TARGET_DEBUG ""] -DSQLITE_DEBUG=1] > -1} {
    msg-result "Note: this is a debug build, so performance will suffer."
  }
}

########################################################################
# Checks for the --debug flag and [define]s TARGET_DEBUG based on
# that.  TARGET_DEBUG is unused in the autoconf build but that is
# arguably a bug.
proc sqlite-handle-debug {} {
  msg-checking "SQLITE_DEBUG build? "
  proj-if-opt-truthy debug {
    define TARGET_DEBUG {-g -DSQLITE_DEBUG=1 -O0 -Wall}
    sqlite-add-feature-flag -DSQLITE_ENABLE_SELECTTRACE -DSQLITE_ENABLE_WHERETRACE
    proj-opt-set memsys5
    msg-result yes
  } {
    define TARGET_DEBUG {-DNDEBUG}
    msg-result no
  }
}

########################################################################
# "soname" for libsqlite3.so. See discussion at:
# https://sqlite.org/src/forumpost/5a3b44f510df8ded
proc sqlite-handle-soname {} {
  define LDFLAGS_LIBSQLITE3_SONAME ""
  if {[proj-opt-was-provided soname]} {
    set soname [join [opt-val soname] ""]
  } else {
    # Enabling soname breaks linking for the --dynlink-tools feature,
    # and this project has no direct use for soname, so default to
    # none. Package maintainers, on the other hand, like to have an
    # soname.
    set soname none
  }
  switch -exact -- $soname {
    none - "" { return 0 }
    legacy    { set soname libsqlite3.so.0 }
    default {
      if {[string match libsqlite3.* $soname]} {
        # use it as-is
      } else {
        # Assume it's a suffix
        set soname "libsqlite3.so.${soname}"
      }
    }
  }
  proc-debug "soname=$soname"
  if {[proj-check-soname $soname]} {
    define LDFLAGS_LIBSQLITE3_SONAME [get-define LDFLAGS_SONAME_PREFIX]$soname
    msg-result "Setting SONAME using: [get-define LDFLAGS_LIBSQLITE3_SONAME]"
  } elseif {[proj-opt-was-provided soname]} {
    # --soname was explicitly requested but not available, so fail fatally
    proj-fatal "This environment does not support SONAME."
  } else {
    # --soname was not explicitly requested but not available, so just warn
    msg-result "This environment does not support SONAME."
  }
}

########################################################################
# If --enable-threadsafe is set, this adds -DSQLITE_THREADSAFE=1 to
# OPT_FEATURE_FLAGS and sets LDFLAGS_PTHREAD to the linker flags
# needed for linking pthread (possibly an empty string). If
# --enable-threadsafe is not set, adds -DSQLITE_THREADSAFE=0 to
# OPT_FEATURE_FLAGS and sets LDFLAGS_PTHREAD to an empty string.
proc sqlite-handle-threadsafe {} {
  msg-checking "Support threadsafe operation? "
  define LDFLAGS_PTHREAD ""
  set enable 0
  proj-if-opt-truthy threadsafe {
    msg-result "Checking for libs..."
    if {[proj-check-function-in-lib pthread_create pthread]
        && [proj-check-function-in-lib pthread_mutexattr_init pthread]} {
      set enable 1
      define LDFLAGS_PTHREAD [get-define lib_pthread_create]
      undefine lib_pthread_create
      undefine lib_pthread_mutexattr_init
    } elseif {[proj-opt-was-provided threadsafe]} {
      user-error "Missing required pthread libraries. Use --disable-threadsafe to disable this check."
    } else {
      msg-result "pthread support not detected"
    }
    # Recall that LDFLAGS_PTHREAD might be empty even if pthreads if
    # found because it's in -lc on some platforms.
  } {
    msg-result "Disabled using --disable-threadsafe"
  }
  sqlite-add-feature-flag -DSQLITE_THREADSAFE=${enable}
  return $enable
}

########################################################################
# Handles the --with-tempstore flag.
#
# The test fixture likes to set SQLITE_TEMP_STORE on its own, so do
# not set that feature flag unless it was explicitly provided to the
# configure script.
proc sqlite-handle-tempstore {} {
  if {[proj-opt-was-provided with-tempstore]} {
    set ts [opt-val with-tempstore no]
    set tsn 1
    msg-checking "Use an in-RAM database for temporary tables? "
    switch -exact -- $ts {
      never  { set tsn 0 }
      no     { set tsn 1 }
      yes    { set tsn 2 }
      always { set tsn 3 }
      default {
        user-error "Invalid --with-tempstore value '$ts'. Use one of: never, no, yes, always"
      }
    }
    msg-result $ts
    sqlite-add-feature-flag -DSQLITE_TEMP_STORE=$tsn
  }
}

########################################################################
# Check for the Emscripten SDK for building the web-based wasm
# components.  The core lib and tools do not require this but ext/wasm
# does. Most of the work is done via [proj-check-emsdk], then this
# function adds the following defines:
#
# - EMCC_WRAPPER = "" or top-srcdir/tool/emcc.sh
# - BIN_WASM_OPT = "" or path to wasm-opt
# - BIN_WASM_STRIP = "" or path to wasm-strip
#
# Noting that:
#
# 1) Not finding the SDK is not fatal at this level, nor is failure to
#    find one of the related binaries.
#
# 2) wasm-strip is part of the wabt package:
#
#   https://github.com/WebAssembly/wabt
#
# and this project requires it for production-mode builds but not dev
# builds.
#
proc sqlite-handle-emsdk {} {
  define EMCC_WRAPPER ""
  define BIN_WASM_STRIP ""
  define BIN_WASM_OPT ""
  set srcdir $::autosetup(srcdir)
  if {$srcdir ne $::autosetup(builddir)} {
    # The EMSDK pieces require writing to the original source tree
    # even when doing an out-of-tree build. The ext/wasm pieces do not
    # support an out-of-tree build so we treat that case as if EMSDK
    # were not found.
    msg-result "Out-of tree build: not checking for EMSDK."
    return
  }
  set emccSh $srcdir/tool/emcc.sh
  set extWasmConfig $srcdir/ext/wasm/config.make
  if {![get-define HAVE_WASI_SDK] && [proj-check-emsdk]} {
    define EMCC_WRAPPER $emccSh
    set emsdkHome [get-define EMSDK_HOME ""]
    proj-assert {"" ne $emsdkHome}
    #define EMCC_WRAPPER ""; # just for testing
    proj-bin-define wasm-strip
    proj-bin-define bash; # ext/wasm/GNUmakefile requires bash
    if {[file-isexec $emsdkHome/upstream/bin/wasm-opt]} {
      define BIN_WASM_OPT $emsdkHome/upstream/bin/wasm-opt
    } else {
      # Maybe there's a copy in the path?
      proj-bin-define wasm-opt BIN_WASM_OPT
    }
    proj-make-from-dot-in $emccSh $extWasmConfig
    catch {exec chmod u+x $emccSh}
  } else {
    define EMCC_WRAPPER ""
    file delete -force -- $emccSh $extWasmConfig
  }
}

########################################################################
# Internal helper for [sqlite-check-line-editing]. Returns a list of
# potential locations under which readline.h might be found.
#
# On some environments this function may perform extra work to help
# sqlite-check-line-editing figure out how to find libreadline and
# friends. It will communicate those results via means other than the
# result value, e.g. by modifying configure --flags.
proc sqlite-get-readline-dir-list {} {
  # Historical note: the dirs list, except for the inclusion of
  # $prefix and some platform-specific dirs, originates from the
  # legacy configure script
  set dirs [list [get-define prefix]]
  switch -glob -- [get-define host] {
    *-linux-android {
      # Possibly termux
      lappend dirs /data/data/com.termux/files/usr
    }
    *-mingw32 {
      lappend dirs /mingw32 /mingw
    }
    *-mingw64 {
      lappend dirs /mingw64 /mingw
    }
    *-haiku {
      lappend dirs /boot/system/develop/headers
      if {[opt-val with-readline-ldflags] in {auto ""}} {
        # If the user did not supply their own --with-readline-ldflags
        # value, hijack that flag to inject options which are known to
        # work on a default Haiku installation.
        if {"" ne [glob -nocomplain /boot/system/lib/libreadline*]} {
          proj-opt-set with-readline-ldflags {-L/boot/system/lib -lreadline}
        }
      }
    }
  }
  lappend dirs /usr /usr/local /usr/local/readline /usr/contrib
  set rv {}
  foreach d $dirs {
    if {[file isdir $d]} {lappend rv $d}
  }
  #proc-debug "dirs=$rv"
  return $rv
}

########################################################################
# sqlite-check-line-editing jumps through proverbial hoops to try to
# find a working line-editing library, setting:
#
#   - HAVE_READLINE to 0 or 1
#   - HAVE_LINENOISE to 0, 1, or 2
#   - HAVE_EDITLINE to 0 or 1
#
# Only one of ^^^ those will be set to non-0.
#
#   - LDFLAGS_READLINE = linker flags or empty string
#
#   - CFLAGS_READLINE = compilation flags for clients or empty string.
#
# Note that LDFLAGS_READLINE and CFLAGS_READLINE may refer to
# linenoise or editline, not necessarily libreadline.  In some cases
# it will set HAVE_READLINE=1 when it's really using editline, for
# reasons described in this function's comments.
#
# Returns a string describing which line-editing approach to use, or
# "none" if no option is available.
#
# Order of checks:
#
#  1) --with-linenoise trumps all others and skips all of the
#     complexities involved with the remaining options.
#
#  2) --editline trumps --readline
#
#  3) --disable-readline trumps --readline
#
#  4) Default to automatic search for optional readline
#
#  5) Try to find readline or editline. If it's not found AND the
#     corresponding --FEATURE flag was explicitly given, fail fatally,
#     else fail silently.
proc sqlite-check-line-editing {} {
  msg-result "Checking for line-editing capability..."
  define HAVE_READLINE 0
  define HAVE_LINENOISE 0
  define HAVE_EDITLINE 0
  define LDFLAGS_READLINE ""
  define CFLAGS_READLINE ""
  set failIfNotFound 0 ; # Gets set to 1 for explicit --FEATURE requests
                         # so that we know whether to fail fatally or not
                         # if the library is not found.
  set libsForReadline {readline edit} ; # -l<LIB> names to check for readline().
                                        # The libedit check changes this.
  set editLibName "readline" ; # "readline" or "editline"
  set editLibDef "HAVE_READLINE" ; # "HAVE_READLINE" or "HAVE_EDITLINE"
  set dirLn [opt-val with-linenoise]
  if {"" ne $dirLn} {
    # Use linenoise from a copy of its sources (not a library)...
    if {![file isdir $dirLn]} {
      proj-fatal "--with-linenoise value is not a directory"
    }
    set lnH $dirLn/linenoise.h
    if {![file exists $lnH] } {
      proj-fatal "Cannot find linenoise.h in $dirLn"
    }
    set lnC ""
    set lnCOpts {linenoise-ship.c linenoise.c}
    foreach f $lnCOpts {
      if {[file exists $dirLn/$f]} {
        set lnC $dirLn/$f
        break;
      }
    }
    if {"" eq $lnC} {
      proj-fatal "Cannot find any of $lnCOpts in $dirLn"
    }
    set flavor ""
    set lnVal [proj-which-linenoise $lnH]
    switch -- $lnVal {
      1 { set flavor "antirez" }
      2 { set flavor "msteveb" }
      default {
        proj-fatal "Cannot determine the flavor of linenoise from $lnH"
      }
    }
    define CFLAGS_READLINE "-I$dirLn $lnC"
    define HAVE_LINENOISE $lnVal
    sqlite-add-shell-opt -DHAVE_LINENOISE=$lnVal
    if {$::sqliteConfig(use-jim-for-codegen) && 2 == $lnVal} {
      define-append CFLAGS_JIMSH -DUSE_LINENOISE [get-define CFLAGS_READLINE]
      user-notice "Adding linenoise support to jimsh."
    }
    return "linenoise ($flavor)"
  } elseif {[opt-bool editline]} {
    # libedit mimics libreadline and on some systems does not have its
    # own header installed (instead, that of libreadline is used).
    #
    # shell.c historically expects HAVE_EDITLINE to be set for
    # libedit, but it then expects to see <editline/readline.h>, which
    # some system's don't actually have despite having libedit.  If we
    # end up finding <editline/readline.h> below, we will use
    # -DHAVE_EDITLINE=1, else we will use -DHAVE_READLINE=1. In either
    # case, we will link against libedit.
    set failIfNotFound 1
    set libsForReadline {edit}
    set editLibName editline
  } elseif {![opt-bool readline]} {
    msg-result "Readline support explicitly disabled with --disable-readline"
    return "none"
  } elseif {[proj-opt-was-provided readline]} {
    # If an explicit --[enable-]readline was used, fail if it's not
    # found, else treat the feature as optional.
    set failIfNotFound 1
  }

  # Transform with-readline-header=X to with-readline-cflags=-I...
  set v [opt-val with-readline-header]
  proj-opt-set with-readline-header ""
  if {"" ne $v} {
    if {"auto" eq $v} {
      proj-opt-set with-readline-cflags auto
    } else {
      set v [file dirname $v]
      if {[string match */readline $v]} {
        # Special case: if the path includes .../readline/readline.h,
        # set the -I to one dir up from that because our sources
        # #include <readline/readline.h> or <editline/readline.h>.
        set v [file dirname $v]
      }
      proj-opt-set with-readline-cflags "-I$v"
    }
  }

  # Look for readline.h
  set rlInc [opt-val with-readline-cflags auto]
  if {"auto" eq $rlInc} {
    set rlInc ""
    if {$::sqliteConfig(is-cross-compiling)} {
      # ^^^ this check is derived from the legacy configure script.
      proj-warn "Skipping check for readline.h because we're cross-compiling."
    } else {
      set dirs [sqlite-get-readline-dir-list]
      set subdirs [list \
                     include/$editLibName \
                     readline]
      if {"editline" eq $editLibName} {
        lappend subdirs include/readline
        # ^^^ editline, on some systems, does not have its own header,
        # and uses libreadline's header.
      }
      lappend subdirs include
      set rlInc [proj-search-for-header-dir readline.h \
                   -dirs $dirs -subdirs $subdirs]
      #proc-debug "rlInc=$rlInc"
      if {"" ne $rlInc} {
        if {[string match */readline $rlInc]} {
          set rlInc [file dirname $rlInc]; # CLI shell: #include <readline/readline.h>
        } elseif {[string match */editline $rlInc]} {
          set editLibDef HAVE_EDITLINE
          set rlInc [file dirname $rlInc]; # CLI shell: #include <editline/readline.h>
        }
        set rlInc "-I${rlInc}"
      }
    }
  } elseif {"" ne $rlInc && ![string match *-I* $rlInc]} {
    proj-fatal "Argument to --with-readline-cflags is intended to be CFLAGS and contain -I..."
  }

  # If readline.h was found/specified, look for lib(readline|edit)...
  #
  # This is not quite straightforward because both libreadline and
  # libedit typically require some other library which (according to
  # legacy autotools-generated tests) provides tgetent(3). On some
  # systems that's built into libreadline/edit, on some (most?) its in
  # lib[n]curses, and on some it's in libtermcap.
  set rlLib ""
  if {"" ne $rlInc} {
    set rlLib [opt-val with-readline-ldflags]
    #proc-debug "rlLib=$rlLib"
    if {$rlLib in {auto ""}} {
      set rlLib ""
      set libTerm ""
      if {[proj-check-function-in-lib tgetent "$editLibName ncurses curses termcap"]} {
        # ^^^ that libs list comes from the legacy configure script ^^^
        set libTerm [get-define lib_tgetent]
        undefine lib_tgetent
      }
      if {$editLibName eq $libTerm} {
        set rlLib $libTerm
      } elseif {[proj-check-function-in-lib readline $libsForReadline $libTerm]} {
        set rlLib [get-define lib_readline]
        lappend rlLib $libTerm
        undefine lib_readline
      }
    }
  }

  # If we found a library, configure the build to use it...
  if {"" ne $rlLib} {
    if {"editline" eq $editLibName && "HAVE_READLINE" eq $editLibDef} {
      # Alert the user that, despite outward appearances, we won't be
      # linking to the GPL'd libreadline. Presumably that distinction is
      # significant for those using --editline.
      proj-indented-notice {
        NOTE: the local libedit uses <readline/readline.h> so we
        will compile with -DHAVE_READLINE=1 but will link with
        libedit.
      }
    }
    set rlLib [join $rlLib]
    set rlInc [join $rlInc]
    define LDFLAGS_READLINE $rlLib
    define CFLAGS_READLINE $rlInc
    proj-assert {$editLibDef in {HAVE_READLINE HAVE_EDITLINE}}
    proj-assert {$editLibName in {readline editline}}
    sqlite-add-shell-opt -D${editLibDef}=1
    msg-result "Using $editLibName flags: $rlInc $rlLib"
    # Check whether rl_completion_matches() has a signature we can use
    # and disable that sub-feature if it doesn't.
    if {![cctest \
            -cflags "$rlInc -D${editLibDef}" -libs $rlLib -nooutput 1 -source {
             #include <stdio.h>
             #ifdef HAVE_EDITLINE
             #include <editline/readline.h>
             #else
             #include <readline/readline.h>
             #endif
             static char * rcg(const char *z, int i){(void)z; (void)i; return 0;}
             int main(void) {
               char ** x = rl_completion_matches("one", rcg);
               (void)x;
               return 0;
             }
           }]} {
      proj-warn "readline-style completion disabled due to rl_completion_matches() signature mismatch"
      sqlite-add-shell-opt -DSQLITE_OMIT_READLINE_COMPLETION
    }
    return $editLibName
  }

  if {$failIfNotFound} {
    proj-fatal "Explicit --$editLibName failed to find a matching library."
  }
  return "none"
}; # sqlite-check-line-editing

########################################################################
# Runs sqlite-check-line-editing and adds a message around it. In the
# canonical build this must not be called before
# sqlite-determine-codegen-tcl for reasons now lost to history (and
# might not still be applicable).
proc sqlite-handle-line-editing {} {
  msg-result "Line-editing support for the sqlite3 shell: [sqlite-check-line-editing]"
}


########################################################################
# ICU - International Components for Unicode
#
# Handles these flags:
#
#  --with-icu-ldflags=LDFLAGS
#  --with-icu-cflags=CFLAGS
#  --with-icu-config[=auto | pkg-config | /path/to/icu-config]
#  --enable-icu-collations
#
# --with-icu-config values:
#
#   - auto: use the first one of (pkg-config, icu-config) found on the
#     system.
#   - pkg-config: use only pkg-config to determine flags
#   - /path/to/icu-config: use that to determine flags
#
# If --with-icu-config is used as neither pkg-config nor icu-config
# are found, fail fatally.
#
# If both --with-icu-ldflags and --with-icu-config are provided, they
# are cumulative.  If neither are provided, icu-collations is not
# honored and a warning is emitted if it is provided.
#
# Design note: though we could automatically enable ICU if the
# icu-config binary or (pkg-config icu-io) are found, we specifically
# do not. ICU is always an opt-in feature.
proc sqlite-handle-icu {} {
  define LDFLAGS_ICU [join [opt-val with-icu-ldflags ""]]
  define CFLAGS_ICU [join [opt-val with-icu-cflags ""]]
  if {[proj-opt-was-provided with-icu-config]} {
    msg-result "Checking for ICU support..."
    set icuConfigBin [opt-val with-icu-config]
    set tryIcuConfigBin 1; # set to 0 if we end up using pkg-config
    if {$icuConfigBin in {auto pkg-config}} {
      if {[pkg-config-init 0] && [pkg-config icu-io]} {
        # Maintenance reminder: historical docs say to use both of
        # (icu-io, icu-uc). icu-uc lacks a required lib and icu-io has
        # all of them on tested OSes.
        set tryIcuConfigBin 0
        define LDFLAGS_ICU [get-define PKG_ICU_IO_LDFLAGS]
        define-append LDFLAGS_ICU [get-define PKG_ICU_IO_LIBS]
        define CFLAGS_ICU [get-define PKG_ICU_IO_CFLAGS]
      } elseif {"pkg-config" eq $icuConfigBin} {
        proj-fatal "pkg-config cannot find package icu-io"
      } else {
        proj-assert {"auto" eq $icuConfigBin}
      }
    }
    if {$tryIcuConfigBin} {
      if {"auto" eq $icuConfigBin} {
        set icuConfigBin [proj-first-bin-of \
                            /usr/local/bin/icu-config \
                            /usr/bin/icu-config]
        if {"" eq $icuConfigBin} {
          proj-indented-notice -error {
            --with-icu-config=auto cannot find (pkg-config icu-io) or icu-config binary.
            On Ubuntu-like systems try:
            --with-icu-ldflags='-licui18n -licuuc -licudata'
          }
        }
      }
      if {[file-isexec $icuConfigBin]} {
        set x [exec $icuConfigBin --ldflags]
        if {"" eq $x} {
          proj-indented-notice -error \
            [subst {
              $icuConfigBin --ldflags returned no data.
              On Ubuntu-like systems try:
              --with-icu-ldflags='-licui18n -licuuc -licudata'
            }]
        }
        define-append LDFLAGS_ICU $x
        set x [exec $icuConfigBin --cppflags]
        define-append CFLAGS_ICU $x
      } else {
        proj-fatal "--with-icu-config=$icuConfigBin does not refer to an executable"
      }
    }
  }
  set ldflags [define LDFLAGS_ICU [string trim [get-define LDFLAGS_ICU]]]
  set cflags [define CFLAGS_ICU [string trim [get-define CFLAGS_ICU]]]
  if {"" ne $ldflags} {
    sqlite-add-feature-flag -shell -DSQLITE_ENABLE_ICU
    msg-result "Enabling ICU support with flags: $ldflags $cflags"
    if {[opt-bool icu-collations]} {
      msg-result "Enabling ICU collations."
      sqlite-add-feature-flag -shell -DSQLITE_ENABLE_ICU_COLLATIONS
      # Recall that shell.c builds with sqlite3.c except in the case
      # of --disable-static-shell, a combination we do not
      # specifically attempt to account for.
    }
  } elseif {[opt-bool icu-collations]} {
    proj-warn "ignoring --enable-icu-collations because neither --with-icu-ldflags nor --with-icu-config provided any linker flags"
  } else {
    msg-result "ICU support is disabled."
  }
}; # sqlite-handle-icu


########################################################################
# Handles the --enable-load-extension flag. Returns 1 if the support
# is enabled, else 0. If support for that feature is not found, a
# fatal error is triggered if --enable-load-extension is explicitly
# provided, else a loud warning is instead emitted. If
# --disable-load-extension is used, no check is performed.
#
# Makes the following environment changes:
#
# - defines LDFLAGS_DLOPEN to any linker flags needed for this
#   feature.  It may legally be empty on some systems where dlopen()
#   is in libc.
#
# - If the feature is not available, adds
#   -DSQLITE_OMIT_LOAD_EXTENSION=1 to the feature flags list.
proc sqlite-handle-load-extension {} {
  define LDFLAGS_DLOPEN ""
  set found 0
  proj-if-opt-truthy load-extension {
    set found [proj-check-function-in-lib dlopen dl]
    if {$found} {
      define LDFLAGS_DLOPEN [get-define lib_dlopen]
      undefine lib_dlopen
    } else {
      if {[proj-opt-was-provided load-extension]} {
        # Explicit --enable-load-extension: fail if not found
        proj-indented-notice -error {
          --enable-load-extension was provided but dlopen()
          not found. Use --disable-load-extension to bypass this
          check.
        }
      } else {
        # It was implicitly enabled: warn if not found
        proj-indented-notice {
          WARNING: dlopen() not found, so loadable module support will
          be disabled. Use --disable-load-extension to bypass this
          check.
        }
      }
    }
  }
  if {$found} {
    msg-result "Loadable extension support enabled."
  } else {
    msg-result "Disabling loadable extension support. Use --enable-load-extension to enable them."
    sqlite-add-feature-flag -DSQLITE_OMIT_LOAD_EXTENSION=1
  }
  return $found
}

########################################################################
# Handles the --enable-math flag.
proc sqlite-handle-math {} {
  proj-if-opt-truthy math {
    if {![proj-check-function-in-lib ceil m]} {
      user-error "Cannot find libm functions. Use --disable-math to bypass this."
    }
    define LDFLAGS_MATH [get-define lib_ceil]
    undefine lib_ceil
    sqlite-add-feature-flag -DSQLITE_ENABLE_MATH_FUNCTIONS
    msg-result "Enabling math SQL functions"
  } {
    define LDFLAGS_MATH ""
    msg-result "Disabling math SQL functions"
  }
}

########################################################################
# If this OS looks like a Mac, checks for the Mac-specific
# -current_version and -compatibility_version linker flags. Defines
# LDFLAGS_MAC_CVERSION to an empty string and returns 0 if they're not
# supported, else defines that to the linker flags and returns 1.
#
# We don't check this on non-Macs because this whole thing is a
# libtool compatibility kludge to account for a version stamp which
# libtool applied only on Mac platforms.
#
# Based on https://sqlite.org/forum/forumpost/9dfd5b8fd525a5d7.
proc sqlite-handle-mac-cversion {} {
  define LDFLAGS_MAC_CVERSION ""
  set rc 0
  if {[proj-looks-like-mac]} {
    cc-with {-link 1} {
      # These version numbers are historical libtool-defined values, not
      # library-defined ones
      if {[cc-check-flags "-Wl,-current_version,9.6.0"]
          && [cc-check-flags "-Wl,-compatibility_version,9.0.0"]} {
        define LDFLAGS_MAC_CVERSION "-Wl,-compatibility_version,9.0.0 -Wl,-current_version,9.6.0"
        set rc 1
      } elseif {[cc-check-flags "-compatibility_version 9.0.0"]
                && [cc-check-flags "-current_version 9.6.0"]} {
        define LDFLAGS_MAC_CVERSION "-compatibility_version 9.0.0 -current_version 9.6.0"
        set rc 1
      }
    }
  }
  return $rc
}

########################################################################
# Handles the --dll-basename configure flag. [define]'s
# SQLITE_DLL_BASENAME to the DLL's preferred base name (minus
# extension). If --dll-basename is not provided (or programmatically
# set - see [sqlite-handle-env-quirks]) then this is always
# "libsqlite3", otherwise it may use a different value based on the
# value of [get-define host].
proc sqlite-handle-dll-basename {} {
  if {[proj-opt-was-provided dll-basename]} {
    set dn [join [opt-val dll-basename] ""]
    if {$dn in {none default}} { set dn libsqlite3 }
  } else {
    set dn libsqlite3
  }
  if {$dn in {auto ""}} {
    switch -glob -- [get-define host] {
      *-*-cygwin  { set dn cygsqlite3-0 }
      *-*-ming*   { set dn libsqlite3-0 }
      *-*-msys    { set dn msys-sqlite3-0 }
      default     { set dn libsqlite3 }
    }
  }
  define SQLITE_DLL_BASENAME $dn
}

########################################################################
# [define]s LDFLAGS_OUT_IMPLIB to either an empty string or to a
# -Wl,... flag for the platform-specific --out-implib flag, which is
# used for building an "import library .dll.a" file on some platforms
# (e.g. msys2, mingw). SQLITE_OUT_IMPLIB is defined to the name of the
# import lib or an empty string. Returns 1 if supported, else 0.
#
# The name of the import library is [define]d in SQLITE_OUT_IMPLIB.
#
# If the configure flag --out-implib is not used (or programmatically
# set) then this simply sets the above-listed defines to empty strings
# (but see [sqlite-handle-env-quirks]).  If that flag is used but the
# capability is not available, a fatal error is triggered.
#
# This feature is specifically opt-in because it's supported on far
# more platforms than actually need it and enabling it causes creation
# of libsqlite3.so.a files which are unnecessary in most environments.
#
# Added in response to: https://sqlite.org/forum/forumpost/0c7fc097b2
#
# Platform notes:
#
# - cygwin sqlite packages historically install no .dll.a file.
#
# - msys2 and mingw sqlite packages historically install
#   /usr/lib/libsqlite3.dll.a despite the DLL being in
#   /usr/bin.
proc sqlite-handle-out-implib {} {
  define LDFLAGS_OUT_IMPLIB ""
  define SQLITE_OUT_IMPLIB ""
  set rc 0
  if {[proj-opt-was-provided out-implib]} {
    set olBaseName [join [opt-val out-implib] ""]
    if {$olBaseName in {auto ""}} {
      set olBaseName "libsqlite3" ;# [get-define SQLITE_DLL_BASENAME]
      # Based on discussions with mingw/msys users, the import lib
      # should always be called libsqlite3.dll.a even on platforms
      # which rename libsqlite3.dll to something else.
    }
    if {$olBaseName ne "none"} {
      cc-with {-link 1} {
        set dll "${olBaseName}[get-define TARGET_DLLEXT]"
        set flags [proj-cc-check-Wl-flag --out-implib ${dll}.a]
        if {"" ne $flags} {
          define LDFLAGS_OUT_IMPLIB $flags
          define SQLITE_OUT_IMPLIB ${dll}.a
          set rc 1
        }
      }
      if {!$rc} {
        user-error "--out-implib is not supported on this platform"
      }
    }
  }
  return $rc
}

########################################################################
# If the given platform identifier (defaulting to [get-define host])
# appears to be one of the Unix-on-Windows environments, returns a
# brief symbolic name for that environment, else returns an empty
# string.
#
# It does not distinguish between msys and msys2, returning msys for
# both. The build does not, as of this writing, specifically support
# msys v1. Similarly, this function returns "mingw" for both "mingw32"
# and "mingw64".
proc sqlite-env-is-unix-on-windows {{envTuple ""}} {
  if {"" eq $envTuple} {
    set envTuple [get-define host]
  }
  set name ""
  switch -glob -- $envTuple {
    *-*-cygwin { set name cygwin }
    *-*-ming*  { set name mingw }
    *-*-msys   { set name msys }
  }
  return $name
}

########################################################################
# Performs various tweaks to the build which are only relevant on
# certain platforms, e.g. Mac and "Unix on Windows" platforms (msys2,
# cygwin, ...).
#
# 1) DLL installation:
#
# [define]s SQLITE_DLL_INSTALL_RULES to a symbolic name suffix for a
# set of "make install" rules to use for installation of the DLL
# deliverable. The makefile is tasked with providing rules named
# install-dll-NAME which runs the installation for that set, as well
# as providing a rule named install-dll which resolves to
# install-dll-NAME (perhaps indirectly, depending on whether the DLL
# is (de)activated).
#
# The default value is "unix-generic".
#
# 2) --out-implib:
#
# On platforms where an "import library" is conventionally used but
# --out-implib was not explicitly used, automatically add that flag.
# This conventionally applies only to the "Unix on Windows"
# environments like msys and cygwin.
#
# 3) --dll-basename:
#
# On the same platforms addressed by --out-implib, if --dll-basename
# is not explicitly specified, --dll-basename=auto is implied.
proc sqlite-handle-env-quirks {} {
  set instName unix-generic; # name of installation rules set
  set autoDll 0; # true if --out-implib/--dll-basename should be implied
  set host [get-define host]
  switch -glob -- $host {
    *apple* -
    *darwin*    { set instName darwin }
    default {
      set x [sqlite-env-is-unix-on-windows $host]
      if {"" ne $x} {
        set instName $x
        set autoDll 1
      }
    }
  }
  define SQLITE_DLL_INSTALL_RULES $instName
  if {$autoDll} {
    if {![proj-opt-was-provided out-implib]} {
      # Imply --out-implib=auto
      proj-indented-notice [subst -nocommands -nobackslashes {
        NOTICE: auto-enabling --out-implib for environment [$host].
        Use --out-implib=none to disable this special case
        or --out-implib=auto to squelch this notice.
      }]
      proj-opt-set out-implib auto
    }
    if {![proj-opt-was-provided dll-basename]} {
      # Imply --dll-basename=auto
      proj-indented-notice [subst -nocommands -nobackslashes {
        NOTICE: auto-enabling --dll-basename for environment [$host].
        Use --dll-basename=default to disable this special case
        or --dll-basename=auto to squelch this notice.
      }]
      proj-opt-set dll-basename auto
    }
  }
  sqlite-handle-dll-basename
  sqlite-handle-out-implib
  sqlite-handle-mac-cversion
  if {[llength [info proc sqlite-custom-handle-flags]] > 0} {
    # sqlite-custom-handle-flags is assumed to be imported via a
    # client-specific import: autosetup/sqlite-custom.tcl.
    sqlite-custom-handle-flags
  }
}

########################################################################
# Perform some late-stage work and generate the configure-process
# output file(s).
proc sqlite-process-dot-in-files {} {
  ########################################################################
  # "Re-export" the autoconf-conventional --XYZdir flags into something
  # which is more easily overridable from a make invocation. See the docs
  # for [proj-remap-autoconf-dir-vars] for the explanation of why.
  #
  # We do this late in the config process, immediately before we export
  # the Makefile and other generated files, so that configure tests
  # which make make use of the autotools-conventional flags
  # (e.g. [proj-check-rpath]) may do so before we "mangle" them here.
  proj-remap-autoconf-dir-vars

  set srcdir $::autosetup(srcdir)/
  foreach f {Makefile sqlite3.pc} {
    if {[file exists $srcdir/$f.in]} {
      # ^^^ we do this only so that this block can be made to work for
      # multiple builds. e.g. the tea build (under construction) does
      # not hae sqlite3.pc.in.
      proj-make-from-dot-in -touch $f
    }
  }
  make-config-header sqlite_cfg.h \
    -bare {SIZEOF_* HAVE_DECL_*} \
    -none {HAVE_CFLAG_* LDFLAGS_* SH_* SQLITE_AUTORECONFIG
      TARGET_* USE_GCOV TCL_*} \
    -auto {HAVE_* PACKAGE_*} \
    -none *
  proj-touch sqlite_cfg.h ; # help avoid frequent unnecessary @SQLITE_AUTORECONFIG@
}

########################################################################
# Perform some high-level validation on the generated files...
#
# 1) Ensure that no unresolved @VAR@ placeholders are in files which
#    use those.
#
# 2) TBD
proc sqlite-post-config-validation {} {
  # Check #1: ensure that files which get filtered for @VAR@ do not
  # contain any unresolved @VAR@ refs. That may indicate an
  # unexported/unused var or a typo.
  set srcdir $::autosetup(srcdir)
  foreach f [list Makefile sqlite3.pc \
             $srcdir/tool/emcc.sh \
             $srcdir/ext/wasm/config.make] {
    if {![file exists $f]} continue
    set lnno 1
    foreach line [proj-file-content-list $f] {
      if {[regexp {(@[A-Za-z0-9_]+@)} $line match]} {
        error "Unresolved reference to $match at line $lnno of $f"
      }
      incr lnno
    }
  }
}

########################################################################
# Handle --with-wasi-sdk[=DIR]
#
# This must be run relatively early on because it may change the
# toolchain and disable a number of config options. However, in the
# canonical build this must come after [sqlite-check-common-bins].
proc sqlite-handle-wasi-sdk {} {
  set wasiSdkDir [opt-val with-wasi-sdk] ; # ??? [lindex [opt-val with-wasi-sdk] end]
  define HAVE_WASI_SDK 0
  if {$wasiSdkDir eq ""} {
    return 0
  } elseif {$::sqliteConfig(is-cross-compiling)} {
    proj-fatal "Cannot combine --with-wasi-sdk with cross-compilation"
  }
  msg-result "Checking WASI SDK directory \[$wasiSdkDir]... "
  proj-affirm-files-exist -v {*}[prefix "$wasiSdkDir/bin/" {clang wasm-ld ar}]
  define HAVE_WASI_SDK 1
  define WASI_SDK_DIR $wasiSdkDir
  # Disable numerous options which we know either can't work or are
  # not useful in this build...
  msg-result "Using wasi-sdk clang. Disabling CLI shell and modifying config flags:"
  # Boolean (--enable-/--disable-) flags which must be switched off:
  foreach opt {
    dynlink-tools
    editline
    gcov
    icu-collations
    load-extension
    readline
    shared
    tcl
    threadsafe
  } {
    if {[proj-opt-exists $opt] && [opt-bool $opt]} {
      # -^^^^ not all builds define all of these flags
      msg-result "  --disable-$opt"
      proj-opt-set $opt 0
    }
  }
  # Non-boolean flags which need to be cleared:
  foreach opt {
    with-emsdk
    with-icu-config
    with-icu-ldflags
    with-icu-cflags
    with-linenoise
    with-tcl
  } {
    if {[proj-opt-was-provided $opt]} {
      msg-result "  removing --$opt"
      proj-opt-set $opt ""
    }
  }
  # Remember that we now have a discrepancy between
  # $::sqliteConfig(is-cross-compiling) and [proj-is-cross-compiling].
  set ::sqliteConfig(is-cross-compiling) 1

  #
  # Changing --host and --target have no effect here except to
  # possibly cause confusion. Autosetup has finished processing them
  # by this point.
  #
  #  host_alias=wasm32-wasi
  #  target=wasm32-wasi
  #
  # Merely changing CC, LD, and AR to the wasi-sdk's is enough to get
  # sqlite3.o building in WASM format.
  #
  define CC "${wasiSdkDir}/bin/clang"
  define LD "${wasiSdkDir}/bin/wasm-ld"
  define AR "${wasiSdkDir}/bin/ar"
  #define STRIP "${wasiSdkDir}/bin/strip"
  return 1
}; # sqlite-handle-wasi-sdk

########################################################################
# TCL...
#
# sqlite-check-tcl performs most of the --with-tcl and --with-tclsh
# handling. Some related bits and pieces are performed before and
# after that function is called.
#
# Important [define]'d vars:
#
#  - HAVE_TCL indicates whether we have a tclsh suitable for building
#    the TCL SQLite extension and, by extension, the testing
#    infrastructure. This must only be 1 for environments where
#    tclConfig.sh can be found.
#
#  - TCLSH_CMD is the path to the canonical tclsh or "". It never
#    refers to jimtcl.
#
#  - TCL_CONFIG_SH is the path to tclConfig.sh or "".
#
#  - TCLLIBDIR is the dir to which libtclsqlite3 gets installed.
#
#  - BTCLSH = the path to the tcl interpreter used for in-tree code
#    generation.  It may be jimtcl or the canonical tclsh but may not
#    be empty - this tree requires TCL to generated numerous
#    components.
#
# If --tcl or --with-tcl are provided but no TCL is found, this
# function fails fatally. If they are not explicitly provided then
# failure to find TCL is not fatal but a loud warning will be emitted.
#
proc sqlite-check-tcl {} {
  define TCLSH_CMD false ; # Significant is that it exits with non-0
  define HAVE_TCL 0      ; # Will be enabled via --tcl or a successful search
  define TCLLIBDIR ""    ; # Installation dir for TCL extension lib
  define TCL_CONFIG_SH ""; # full path to tclConfig.sh

  # Clear out all vars which would harvest from tclConfig.sh so that
  # the late-config validation of @VARS@ works even if --disable-tcl
  # is used.
  proj-tclConfig-sh-to-autosetup ""

  file delete -force ".tclenv.sh"; # ensure no stale state from previous configures.
  if {![opt-bool tcl]} {
    proj-indented-notice {
      NOTE: TCL is disabled via --disable-tcl. This means that none
      of the TCL-based components will be built, including tests
      and sqlite3_analyzer.
    }
    return
  }
  # TODO: document the steps this is taking.
  set srcdir $::autosetup(srcdir)
  msg-result "Checking for a suitable tcl... "
  proj-assert [proj-opt-truthy tcl]
  set use_tcl 1
  set with_tclsh [opt-val with-tclsh]
  set with_tcl [opt-val with-tcl]
  if {"prefix" eq $with_tcl} {
    set with_tcl [get-define prefix]
  }
  proc-debug "use_tcl ${use_tcl}"
  proc-debug "with_tclsh=${with_tclsh}"
  proc-debug "with_tcl=$with_tcl"
  if {"" eq $with_tclsh && "" eq $with_tcl} {
    # If neither --with-tclsh nor --with-tcl are provided, try to find
    # a workable tclsh.
    set with_tclsh [proj-first-bin-of tclsh9.1 tclsh9.0 tclsh8.6 tclsh]
    proc-debug "with_tclsh=${with_tclsh}"
  }

  set doConfigLookup 1 ; # set to 0 to test the tclConfig.sh-not-found cases
  if {"" ne $with_tclsh} {
    # --with-tclsh was provided or found above. Validate it and use it
    # to trump any value passed via --with-tcl=DIR.
    if {![file-isexec $with_tclsh]} {
      proj-fatal "TCL shell $with_tclsh is not executable"
    } else {
      define TCLSH_CMD $with_tclsh
      #msg-result "Using tclsh: $with_tclsh"
    }
    if {$doConfigLookup &&
        [catch {exec $with_tclsh $::autosetup(libdir)/find_tclconfig.tcl} result] == 0} {
      set with_tcl $result
    }
    if {"" ne $with_tcl && [file isdir $with_tcl]} {
      msg-result "$with_tclsh recommends the tclConfig.sh from $with_tcl"
    } else {
      proj-warn "$with_tclsh is unable to recommend a tclConfig.sh"
      set use_tcl 0
    }
  }
  set cfg ""
  set tclSubdirs {tcl9.1 tcl9.0 tcl8.6 lib}
  while {$use_tcl} {
    if {"" ne $with_tcl} {
      # Ensure that we can find tclConfig.sh under ${with_tcl}/...
      if {$doConfigLookup} {
        if {[file readable "${with_tcl}/tclConfig.sh"]} {
          set cfg "${with_tcl}/tclConfig.sh"
        } else {
          foreach i $tclSubdirs {
            if {[file readable "${with_tcl}/$i/tclConfig.sh"]} {
              set cfg "${with_tcl}/$i/tclConfig.sh"
              break
            }
          }
        }
      }
      if {"" eq $cfg} {
        proj-fatal "No tclConfig.sh found under ${with_tcl}"
      }
    } else {
      # If we have not yet found a tclConfig.sh file, look in $libdir
      # which is set automatically by autosetup or via the --prefix
      # command-line option.  See
      # https://sqlite.org/forum/forumpost/e04e693439a22457
      set libdir [get-define libdir]
      if {[file readable "${libdir}/tclConfig.sh"]} {
        set cfg "${libdir}/tclConfig.sh"
      } else {
        foreach i $tclSubdirs {
          if {[file readable "${libdir}/$i/tclConfig.sh"]} {
            set cfg "${libdir}/$i/tclConfig.sh"
            break
          }
        }
      }
      if {![file readable $cfg]} {
        break
      }
    }
    msg-result "Using tclConfig.sh: $cfg"
    break
  }
  define TCL_CONFIG_SH $cfg
  # Export a subset of tclConfig.sh to the current TCL-space.  If $cfg
  # is an empty string, this emits empty-string entries for the
  # various options we're interested in.
  proj-tclConfig-sh-to-autosetup $cfg

  if {"" eq $with_tclsh && $cfg ne ""} {
    # We have tclConfig.sh but no tclsh. Attempt to locate a tclsh
    # based on info from tclConfig.sh.
    set tclExecPrefix [get-define TCL_EXEC_PREFIX]
    proj-assert {"" ne $tclExecPrefix}
    set tryThese [list \
                    $tclExecPrefix/bin/tclsh[get-define TCL_VERSION] \
                    $tclExecPrefix/bin/tclsh ]
    foreach trySh $tryThese {
      if {[file-isexec $trySh]} {
        set with_tclsh $trySh
        break
      }
    }
    if {![file-isexec $with_tclsh]} {
      proj-warn "Cannot find a usable tclsh (tried: $tryThese)
    }
  }
  define TCLSH_CMD $with_tclsh
  if {$use_tcl} {
    # Set up the TCLLIBDIR
    #
    # 2024-10-28: calculation of TCLLIBDIR is now done via the shell
    # in main.mk (search it for T.tcl.env.sh) so that
    # static/hand-written makefiles which import main.mk do not have
    # to define that before importing main.mk. Even so, we export
    # TCLLIBDIR from here, which will cause the canonical makefile to
    # use this one rather than to re-calculate it at make-time.
    set tcllibdir [get-env TCLLIBDIR ""]
    if {"" eq $tcllibdir} {
      # Attempt to extract TCLLIBDIR from TCL's $auto_path
      if {"" ne $with_tclsh &&
          [catch {exec echo "puts stdout \$auto_path" | "$with_tclsh"} result] == 0} {
        foreach i $result {
          if {[file isdir $i]} {
            set tcllibdir $i/sqlite3
            break
          }
        }
      } else {
        proj-warn "Cannot determine TCLLIBDIR."
        # The makefile will fail fatally in this case if a target is
        # invoked which requires TCLLIBDIR.
      }
    }
    #if {"" ne $tcllibdir} { msg-result "TCLLIBDIR = ${tcllibdir}"; }
    define TCLLIBDIR $tcllibdir
  }; # find TCLLIBDIR

  if {[file-isexec $with_tclsh]} {
    msg-result "Using tclsh: $with_tclsh"
    if {$cfg ne ""} {
      define HAVE_TCL 1
    } else {
      proj-warn "Found tclsh but no tclConfig.sh."
    }
  }
  show-notices
  # If TCL is not found: if it was explicitly requested then fail
  # fatally, else just emit a warning. If we can find the APIs needed
  # to generate a working JimTCL then that will suffice for build-time
  # TCL purposes (see: proc sqlite-determine-codegen-tcl).
  if {![get-define HAVE_TCL] &&
      ([proj-opt-was-provided tcl] || [proj-opt-was-provided with-tcl])} {
    proj-fatal "TCL support was requested but no tclConfig.sh could be found."
  }
  if {"" eq $cfg} {
    proj-assert {0 == [get-define HAVE_TCL]}
    proj-indented-notice {
      WARNING: Cannot find a usable tclConfig.sh file.  Use
      --with-tcl=DIR to specify a directory where tclConfig.sh can be
      found.  SQLite does not use TCL internally, but some optional
      components require TCL, including tests and sqlite3_analyzer.
    }
  }
}; # sqlite-check-tcl

########################################################################
# sqlite-determine-codegen-tcl checks which TCL to use as a code
# generator.  By default, prefer jimsh simply because we have it
# in-tree (it's part of autosetup) unless --with-tclsh=X is used, in
# which case prefer X.
#
# Returns the human-readable name of the TCL it selects. Fails fatally
# if it cannot detect a TCL appropriate for code generation.
#
# Defines:
#
#   - BTCLSH = the TCL shell used for code generation. It may set this
#     to an unexpanded makefile var name.
#
#   - CFLAGS_JIMSH = any flags needed for buildng a BTCLSH-compatible
#     jimsh. The defaults may be passed on to configure as
#     CFLAGS_JIMSH=...
proc sqlite-determine-codegen-tcl {} {
  msg-result "Checking for TCL to use for code generation... "
  define CFLAGS_JIMSH [proj-get-env CFLAGS_JIMSH {-O1}]
  set cgtcl [opt-val with-tclsh jimsh]
  if {"jimsh" ne $cgtcl} {
    # When --with-tclsh=X is used, use that for all TCL purposes,
    # including in-tree code generation, per developer request.
    define BTCLSH "\$(TCLSH_CMD)"
    return $cgtcl
  }
  set flagsToRestore {CC CFLAGS AS_CFLAGS CPPFLAGS AS_CPPFLAGS LDFLAGS LINKFLAGS LIBS CROSS}
  define-push $flagsToRestore {
    # We have to swap CC to CC_FOR_BUILD for purposes of the various
    # [cc-...] tests below. Recall that --with-wasi-sdk may have
    # swapped out CC with one which is not appropriate for this block.
    # Per consulation with autosetup's creator, doing this properly
    # requires us to [define-push] the whole $flagsToRestore list
    # (plus a few others which are not relevant in this tree).
    #
    # These will get set to their previous values at the end of this
    # block.
    foreach flag $flagsToRestore {define $flag ""}
    define CC [get-define CC_FOR_BUILD]
    # These headers are technically optional for JimTCL but necessary if
    # we want to use it for code generation:
    set sysh [cc-check-includes dirent.h sys/time.h]
    # jimsh0.c hard-codes #define's for HAVE_DIRENT_H and
    # HAVE_SYS_TIME_H on the platforms it supports, so we do not
    # need to add -D... flags for those. We check for them here only
    # so that we can avoid the situation that we later, at
    # make-time, try to compile jimsh but it then fails due to
    # missing headers (i.e. fail earlier rather than later).
    if {$sysh && [cc-check-functions realpath]} {
      define-append CFLAGS_JIMSH -DHAVE_REALPATH
      define BTCLSH "\$(JIMSH)"
      set ::sqliteConfig(use-jim-for-codegen) 1
    } elseif {$sysh && [cc-check-functions _fullpath]} {
      # _fullpath() is a Windows API. It's not entirely clear
      # whether we need to add {-DHAVE_SYS_TIME_H -DHAVE_DIRENT_H}
      # to CFLAGS_JIMSH in this case. On MinGW32 we definitely do
      # not want to because it already hard-codes them. On _MSC_VER
      # builds it does not.
      define-append CFLAGS_JIMSH -DHAVE__FULLPATH
      define BTCLSH "\$(JIMSH)"
      set ::sqliteConfig(use-jim-for-codegen) 1
    } elseif {[file-isexec [get-define TCLSH_CMD]]} {
      set cgtcl [get-define TCLSH_CMD]
      define BTCLSH "\$(TCLSH_CMD)"
    } else {
      # One last-ditch effort to find TCLSH_CMD: use info from
      # tclConfig.sh to try to find a tclsh
      if {"" eq [get-define TCLSH_CMD]} {
        set tpre [get-define TCL_EXEC_PREFIX]
        if {"" ne $tpre} {
          set tv [get-define TCL_VERSION]
          if {[file-isexec "${tpre}/bin/tclsh${tv}"]} {
            define TCLSH_CMD "${tpre}/bin/tclsh${tv}"
          } elseif {[file-isexec "${tpre}/bin/tclsh"]} {
            define TCLSH_CMD "${tpre}/bin/tclsh"
          }
        }
      }
      set cgtcl [get-define TCLSH_CMD]
      if {![file-isexec $cgtcl]} {
        proj-fatal "Cannot find a tclsh to use for code generation."
      }
      define BTCLSH "\$(TCLSH_CMD)"
    }
  }; # /define-push $flagsToRestore
  return $cgtcl
}; # sqlite-determine-codegen-tcl

########################################################################
# Runs sqlite-check-tcl and, if $alsoCheckCodeGen is true,
# sqlite-determine-codegen-tcl (intended only for the canonical
# build).
proc sqlite-handle-tcl {{alsoCheckCodeGen 1}} {
  sqlite-check-tcl
  if {$alsoCheckCodeGen} {
    msg-result "TCL for code generation: [sqlite-determine-codegen-tcl]"
  }
}

########################################################################
# Handle the --enable/disable-rpath flag.
proc sqlite-handle-rpath {} {
  proj-check-rpath
  # autosetup/cc-shared.tcl sets the rpath flag definition in
  # [get-define SH_LINKRPATH], but it does so on a per-platform basis
  # rather than as a compiler check. Though we should do a proper
  # compiler check (as proj-check-rpath does), we may want to consider
  # adopting its approach of clearing the rpath flags for environments
  # for which sqlite-env-is-unix-on-windows returns a non-empty
  # string.

#  if {[proj-opt-truthy rpath]} {
#    proj-check-rpath
#  } else {
#    msg-result "Disabling use of rpath."
#    define LDFLAGS_RPATH ""
#  }
}

########################################################################
# If the --dump-defines configure flag is provided then emit a list of
# all [define] values to config.defines.txt, else do nothing.
proc sqlite-dump-defines {} {
  proj-if-opt-truthy dump-defines {
    make-config-header $::sqliteConfig(dump-defines-txt) \
      -bare {SQLITE_OS* SQLITE_DEBUG USE_*} \
      -str {BIN_* CC LD AR LDFLAG* OPT_*} \
      -auto {*}
    # achtung: ^^^^ whichever SQLITE_OS_foo flag which is set to 0 will
    # get _undefined_ here unless it's part of the -bare set.
    if {"" ne $::sqliteConfig(dump-defines-json)} {
      msg-result "--dump-defines is creating $::sqliteConfig(dump-defines-json)"
      ########################################################################
      # Dump config-defines.json...
      # Demonstrate (mis?)handling of spaces in JSON-export array values:
      # define-append OPT_FOO.list {"-DFOO=bar baz" -DBAR="baz barre"}
      define OPT_FEATURE_FLAGS.list [get-define OPT_FEATURE_FLAGS]
      define OPT_SHELL.list [get-define OPT_SHELL]
      set dumpDefsOpt {
        -bare {SIZEOF_* HAVE_DECL_*}
        -none {HAVE_CFLAG_* LDFLAGS_* SH_* SQLITE_AUTORECONFIG TARGET_* USE_GCOV TCL_*}
        -array {*.list}
        -auto {OPT_* PACKAGE_* HAVE_*}
      }
#      if {$::sqliteConfig(dump-defines-json-include-lowercase)} {
#        lappend dumpDefsOpt -none {lib_*} ; # remnants from proj-check-function-in-lib and friends
#        lappend dumpDefsOpt -auto {[a-z]*}
#      }
      lappend dumpDefsOpt -none *
      proj-dump-defs-json $::sqliteConfig(dump-defines-json) {*}$dumpDefsOpt
      undefine OPT_FEATURE_FLAGS.list
      undefine OPT_SHELL.list
    }
  }
}