Absorb -D_USE_32BIT_TIME_T switch from Perl, if relevant.

tglsfdc · tglsfdc · commit 5a5c2feca3fd · 2017-08-14T11:48:59.000-04:00
Commit 3c163a7's original choice to ignore all #define symbols whose names begin with underscore turns out to be too simplistic. On Windows, some Perl installations are built with -D_USE_32BIT_TIME_T, and we must absorb that or we get the wrong result for sizeof(PerlInterpreter). This effectively re-reverts commit ef58b87, which injected that symbol in a hacky way, making it apply to all of Postgres not just PL/Perl. More significantly, it did so on *all* 32-bit Windows builds, even when the Perl build to be used did not select this option; so that it fails to work properly with some newer Perl builds. By making this change, we would be introducing an ABI break in 32-bit Windows builds; but fortunately we have not used type time_t in any exported Postgres APIs in a long time. So it should be OK, both for PL/Perl itself and for third-party extensions, if an extension library is built with a different _USE_32BIT_TIME_T setting than the core code. Patch by me, based on research by Ashutosh Sharma and Robert Haas. Back-patch to all supported branches, as commit 3c163a7 was. Discussion: https://postgr.es/m/CANFyU97OVQ3+Mzfmt3MhuUm5NwPU=-FtbNH5Eb7nZL9ua8=rcA@mail.gmail.com
diff --git a/config/perl.m4 b/config/perl.m4
@@ -56,7 +56,9 @@ AC_DEFUN([PGAC_CHECK_PERL_CONFIGS],
 # to a different libc ABI than core Postgres uses.  The available information
 # says that all the symbols that affect Perl's own ABI begin with letters,
 # so it should be sufficient to adopt -D switches for symbols not beginning
-# with underscore.
+# with underscore.  An exception is that we need to let through
+# -D_USE_32BIT_TIME_T if it's present.  (We probably could restrict that to
+# only get through on Windows, but for the moment we let it through always.)
 # For debugging purposes, let's have the configure output report the raw
 # ccflags value as well as the set of flags we chose to adopt.
 AC_DEFUN([PGAC_CHECK_PERL_EMBED_CCFLAGS],
@@ -65,7 +67,7 @@ AC_MSG_CHECKING([for CFLAGS recommended by Perl])
 perl_ccflags=`$PERL -MConfig -e ['print $Config{ccflags}']`
 AC_MSG_RESULT([$perl_ccflags])
 AC_MSG_CHECKING([for CFLAGS to compile embedded Perl])
-perl_embed_ccflags=`$PERL -MConfig -e ['foreach $f (split(" ",$Config{ccflags})) {print $f, " " if ($f =~ /^-D[^_]/)}']`
+perl_embed_ccflags=`$PERL -MConfig -e ['foreach $f (split(" ",$Config{ccflags})) {print $f, " " if ($f =~ /^-D[^_]/ || $f =~ /^-D_USE_32BIT_TIME_T/)}']`
 AC_SUBST(perl_embed_ccflags)dnl
 AC_MSG_RESULT([$perl_embed_ccflags])
 ])# PGAC_CHECK_PERL_EMBED_CCFLAGS
diff --git a/configure b/configure
@@ -7866,7 +7866,7 @@ perl_ccflags=`$PERL -MConfig -e 'print $Config{ccflags}'`
 $as_echo "$perl_ccflags" >&6; }
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for CFLAGS to compile embedded Perl" >&5
 $as_echo_n "checking for CFLAGS to compile embedded Perl... " >&6; }
-perl_embed_ccflags=`$PERL -MConfig -e 'foreach $f (split(" ",$Config{ccflags})) {print $f, " " if ($f =~ /^-D[^_]/)}'`
+perl_embed_ccflags=`$PERL -MConfig -e 'foreach $f (split(" ",$Config{ccflags})) {print $f, " " if ($f =~ /^-D[^_]/ || $f =~ /^-D_USE_32BIT_TIME_T/)}'`
 { $as_echo "$as_me:${as_lineno-$LINENO}: result: $perl_embed_ccflags" >&5
 $as_echo "$perl_embed_ccflags" >&6; }
 
diff --git a/src/tools/msvc/MSBuildProject.pm b/src/tools/msvc/MSBuildProject.pm
@@ -63,21 +63,16 @@ EOF
   </PropertyGroup>
 EOF
 
-	# We have to use this flag on 32 bit targets because the 32bit perls
-	# are built with it and sometimes crash if we don't.
-	my $use_32bit_time_t =
-	  $self->{platform} eq 'Win32' ? '_USE_32BIT_TIME_T;' : '';
-
 	$self->WriteItemDefinitionGroup(
 		$f, 'Debug',
-		{   defs    => "_DEBUG;DEBUG=1;$use_32bit_time_t",
+		{   defs    => "_DEBUG;DEBUG=1",
 			opt     => 'Disabled',
 			strpool => 'false',
 			runtime => 'MultiThreadedDebugDLL' });
 	$self->WriteItemDefinitionGroup(
 		$f,
 		'Release',
-		{   defs    => "$use_32bit_time_t",
+		{   defs    => "",
 			opt     => 'Full',
 			strpool => 'true',
 			runtime => 'MultiThreadedDLL' });
diff --git a/src/tools/msvc/Mkvcbuild.pm b/src/tools/msvc/Mkvcbuild.pm
@@ -522,14 +522,15 @@ sub mkvcbuild
 		my @perl_embed_ccflags;
 		foreach my $f (split(" ",$Config{ccflags}))
 		{
-			if ($f =~ /^-D[^_]/)
+			if ($f =~ /^-D[^_]/ ||
+			    $f =~ /^-D_USE_32BIT_TIME_T/)
 			{
 				$f =~ s/\-D//;
 				push(@perl_embed_ccflags, $f);
 			}
 		}
 
-		# XXX this probably is redundant now?
+		# Also, a hack to prevent duplicate definitions of uid_t/gid_t
 		push(@perl_embed_ccflags, 'PLPERL_HAVE_UID_GID');
 
 		foreach my $f (@perl_embed_ccflags)
diff --git a/src/tools/msvc/VCBuildProject.pm b/src/tools/msvc/VCBuildProject.pm
@@ -33,23 +33,17 @@ sub WriteHeader
  <Configurations>
 EOF
 
-	# We have to use this flag on 32 bit targets because the 32bit perls
-	# are built with it and sometimes crash if we don't.
-	my $use_32bit_time_t =
-	  $self->{platform} eq 'Win32' ? '_USE_32BIT_TIME_T;' : '';
-
-
 	$self->WriteConfiguration(
 		$f, 'Debug',
-		{   defs     => "_DEBUG;DEBUG=1;$use_32bit_time_t",
+		{   defs     => "_DEBUG;DEBUG=1",
 			wholeopt => 0,
 			opt      => 0,
 			strpool  => 'false',
 			runtime  => 3 });
 	$self->WriteConfiguration(
 		$f,
 		'Release',
-		{   defs     => "$use_32bit_time_t",
+		{   defs     => "",
 			wholeopt => 0,
 			opt      => 3,
 			strpool  => 'true',

Original file line number	Diff line number	Diff line change
`@@ -522,14 +522,15 @@ sub mkvcbuild`
`522`	`522`	`my @perl_embed_ccflags;`
`523`	`523`	`foreach my $f (split(" ",$Config{ccflags}))`
`524`	`524`	`{`
`525`		`- if ($f =~ /^-D[^_]/)`
	`525`	`+ if ($f =~ /^-D[^_]/ \|\|`
	`526`	`+ $f =~ /^-D_USE_32BIT_TIME_T/)`
`526`	`527`	`{`
`527`	`528`	`$f =~ s/\-D//;`
`528`	`529`	`push(@perl_embed_ccflags, $f);`
`529`	`530`	`}`
`530`	`531`	`}`
`531`	`532`
`532`		`- # XXX this probably is redundant now?`
	`533`	`+ # Also, a hack to prevent duplicate definitions of uid_t/gid_t`
`533`	`534`	`push(@perl_embed_ccflags, 'PLPERL_HAVE_UID_GID');`
`534`	`535`
`535`	`536`	`foreach my $f (@perl_embed_ccflags)`