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

diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 030285c1fda296f6f5ba506784b9c02059694c1a..b1846e31e3767621c240ea58ebb54234966eb5ce 100644 (file)
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -1377,6 +1377,7 @@ generic_set:
                    n->name = $1;
                    $$ = n;
                }
+       ;
 
 set_rest_more: /* Generic SET syntaxes: */
            generic_set                         {$$ = $1;}

diff --git a/src/interfaces/ecpg/preproc/check_rules.pl b/src/interfaces/ecpg/preproc/check_rules.pl
index e34d7a18607c7e11b2d052823410f63585614d8f..9fc8d8a4e41b31665ecfaae725fce0c38ccb1002 100644 (file)
--- 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) 2009-2014, 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 (<GRAM>)
            $found{$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 (<GRAM>)
    }
 }
 
+die "unterminated rule at end of grammar\n"
+  if $in_rule;
+
 close GRAM;
 if ($verbose)
 {

diff --git a/src/interfaces/ecpg/preproc/parse.pl b/src/interfaces/ecpg/preproc/parse.pl
index d33ab180d63cdb084622617aa5353af787a8c580..d892abeb865991999a03fc7b327ea5cc4bfa6c1c 100644 (file)
--- 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;
@@ -285,6 +286,7 @@ sub main
                @fields  = ();
                $infield = 0;
                $line    = '';
+               $in_rule = 0;
                next;
            }
 
@@ -362,6 +364,9 @@ sub main
                $line    = '';
                @fields  = ();
                $infield = 1;
+               die "unterminated rule at grammar line $.\n"
+                 if $in_rule;
+               $in_rule = 1;
                next;
            }
            elsif ($copymode)
@@ -412,6 +417,9 @@ sub main
            }
        }
    }
+   die "unterminated rule at end of grammar\n"
+     if $in_rule;
+   return;
 }