From 8ec638e69c01e589a3e0c11fbe9ad21c0a3549f1 Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Sun, 24 Feb 2019 12:51:50 -0500
Subject: [PATCH] Fix ecpg bugs caused by missing semicolons in the backend
grammar.
The Bison documentation clearly states that a semicolon is required
after every grammar rule, and our scripts that generate ecpg's
grammar from the backend's implicitly assumed this is true. But it
turns out that only ancient versions of Bison actually enforce that.
There have been a couple of rules without trailing semicolons in
gram.y for some time, and as a consequence, ecpg's grammar was faulty
and produced wrong output for the affected statements.
To fix, add the missing semis, and add some cross-checks to ecpg's
scripts so that they'll bleat if we mess this up again.
The cases that were broken were:
* "SET variable = DEFAULT" (but not "SET variable TO DEFAULT"),
as well as allied syntaxes such as ALTER SYSTEM SET ... DEFAULT.
These produced syntactically invalid output that the server
would reject.
* Multiple type names in DROP TYPE/DOMAIN commands. Only the
first type name would be listed in the emitted command.
Per report from Daisuke Higuchi. Back-patch to all supported versions.
Discussion: https://postgr.es/m/1803D792815FC24D871C00D17AE95905DB51CE@g01jpexmbkw24
---
src/backend/parser/gram.y | 2 ++
src/interfaces/ecpg/preproc/check_rules.pl | 12 ++++++++++--
src/interfaces/ecpg/preproc/parse.pl | 8 ++++++++
3 files changed, 20 insertions(+), 2 deletions(-)
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index a8ce22f3117..53773a9e99a 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -1443,6 +1443,7 @@ generic_set:
n->name = $1;
$$ = n;
}
+ ;
set_rest_more: /* Generic SET syntaxes: */
generic_set {$$ = $1;}
@@ -6192,6 +6193,7 @@ attrs: '.' attr_name
type_name_list:
Typename { $$ = list_make1($1); }
| type_name_list ',' Typename { $$ = lappend($1, $3); }
+ ;
/*****************************************************************************
*
diff --git a/src/interfaces/ecpg/preproc/check_rules.pl b/src/interfaces/ecpg/preproc/check_rules.pl
index e681943856b..b1501d0804e 100644
--- a/src/interfaces/ecpg/preproc/check_rules.pl
+++ b/src/interfaces/ecpg/preproc/check_rules.pl
@@ -1,7 +1,7 @@
#!/usr/bin/perl
# src/interfaces/ecpg/preproc/check_rules.pl
-# test parser generater for ecpg
-# call with backend parser as stdin
+# test parser generator for ecpg
+# call with backend grammar as stdin
#
# Copyright (c) 2009-2017, PostgreSQL Global Development Group
#
@@ -47,6 +47,7 @@ my %replace_line = (
my $block = '';
my $yaccmode = 0;
+my $in_rule = 0;
my $brace_indent = 0;
my (@arr, %found);
my $comment = 0;
@@ -131,10 +132,14 @@ while (<$parser_fh>)
$found{$block} = 1;
$cc++;
$block = '';
+ $in_rule = 0 if $arr[$fieldIndexer] eq ';';
}
elsif (($arr[$fieldIndexer] =~ '[A-Za-z0-9]+:')
|| $arr[ $fieldIndexer + 1 ] eq ':')
{
+ die "unterminated rule at grammar line $.\n"
+ if $in_rule;
+ $in_rule = 1;
$non_term_id = $arr[$fieldIndexer];
$non_term_id =~ tr/://d;
}
@@ -145,6 +150,9 @@ while (<$parser_fh>)
}
}
+die "unterminated rule at end of grammar\n"
+ if $in_rule;
+
close $parser_fh;
if ($verbose)
{
diff --git a/src/interfaces/ecpg/preproc/parse.pl b/src/interfaces/ecpg/preproc/parse.pl
index 768df3a6b1c..7ed43e6a87f 100644
--- a/src/interfaces/ecpg/preproc/parse.pl
+++ b/src/interfaces/ecpg/preproc/parse.pl
@@ -22,6 +22,7 @@ $path = "." unless $path;
my $copymode = 0;
my $brace_indent = 0;
my $yaccmode = 0;
+my $in_rule = 0;
my $header_included = 0;
my $feature_not_supported = 0;
my $tokenmode = 0;
@@ -288,6 +289,7 @@ sub main
@fields = ();
$infield = 0;
$line = '';
+ $in_rule = 0;
next;
}
@@ -365,6 +367,9 @@ sub main
$line = '';
@fields = ();
$infield = 1;
+ die "unterminated rule at grammar line $.\n"
+ if $in_rule;
+ $in_rule = 1;
next;
}
elsif ($copymode)
@@ -415,6 +420,9 @@ sub main
}
}
}
+ die "unterminated rule at end of grammar\n"
+ if $in_rule;
+ return;
}