MSVC: Test whether 32-bit Perl needs -D_USE_32BIT_TIME_T.

Commits 5a5c2feca3 and
b5178c5d08 introduced support for modern
MSVC-built, 32-bit Perl, but they broke use of MinGW-built, 32-bit Perl
distributions like Strawberry Perl and modern ActivePerl.  Perl has no
robust means to report whether it expects a -D_USE_32BIT_TIME_T ABI, so
test this.  Back-patch to 9.3 (all supported versions).

The chief alternative was a heuristic of adding -D_USE_32BIT_TIME_T when
$Config{gccversion} is nonempty.  That banks on every gcc-built Perl
using the same ABI.  gcc could change its default ABI the way MSVC once
did, and one could build Perl with gcc and the non-default ABI.

The GNU make build system could benefit from a similar test, without
which it does not support MSVC-built Perl.  For now, just add a comment.
Most users taking the special step of building Perl with MSVC probably
build PostgreSQL with MSVC.

Discussion: https://postgr.es/m/20171130041441.GA3161526@rfd.leadboat.com
This commit is contained in:
Noah Misch 2017-12-08 18:06:05 -08:00
parent 85a83a3cc6
commit 1c1a572d05
2 changed files with 158 additions and 42 deletions

View File

@ -51,19 +51,23 @@ AC_DEFUN([PGAC_CHECK_PERL_CONFIGS],
# PGAC_CHECK_PERL_EMBED_CCFLAGS
# -----------------------------
# We selectively extract stuff from $Config{ccflags}. We don't really need
# anything except -D switches, and other sorts of compiler switches can
# actively break things if Perl was compiled with a different compiler.
# Moreover, although Perl likes to put stuff like -D_LARGEFILE_SOURCE and
# -D_FILE_OFFSET_BITS=64 here, it would be fatal to try to compile PL/Perl
# 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. 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.
# We selectively extract stuff from $Config{ccflags}. 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. We don't really need anything except -D
# switches, and other sorts of compiler switches can actively break things if
# Perl was compiled with a different compiler. Moreover, although Perl likes
# to put stuff like -D_LARGEFILE_SOURCE and -D_FILE_OFFSET_BITS=64 here, it
# would be fatal to try to compile PL/Perl to a different libc ABI than core
# Postgres uses. The available information says that most symbols that affect
# Perl's own ABI begin with letters, so it's almost sufficient to adopt -D
# switches for symbols not beginning with underscore. Some exceptions are the
# Windows-specific -D_USE_32BIT_TIME_T and -D__MINGW_USE_VC2005_COMPAT; see
# Mkvcbuild.pm for details. We absorb the former when Perl reports it. Perl
# never reports the latter, and we don't attempt to deduce when it's needed.
# Consequently, we don't support using MinGW to link to MSVC-built Perl. As
# of 2017, all supported ActivePerl and Strawberry Perl are MinGW-built. If
# that changes or an MSVC-built Perl distribution becomes prominent, we can
# revisit this limitation.
AC_DEFUN([PGAC_CHECK_PERL_EMBED_CCFLAGS],
[AC_REQUIRE([PGAC_PATH_PERL])
AC_MSG_CHECKING([for CFLAGS recommended by Perl])

View File

@ -27,6 +27,7 @@ my $libpgport;
my $libpgcommon;
my $postgres;
my $libpq;
my @unlink_on_exit;
# Set of variables for modules in contrib/ and src/test/modules/
my $contrib_defines = { 'refint' => 'REFINT_VERBOSE' };
@ -508,34 +509,154 @@ sub mkvcbuild
my $plperl =
$solution->AddProject('plperl', 'dll', 'PLs', 'src/pl/plperl');
$plperl->AddIncludeDir($solution->{options}->{perl} . '/lib/CORE');
$plperl->AddReference($postgres);
my $perl_path = $solution->{options}->{perl} . '\lib\CORE\*perl*';
# ActivePerl 5.16 provided perl516.lib; 5.18 provided libperl518.a
my @perl_libs =
grep { /perl\d+\.lib$|libperl\d+\.a$/ } glob($perl_path);
if (@perl_libs == 1)
{
$plperl->AddLibrary($perl_libs[0]);
}
else
{
die
"could not identify perl library version matching pattern $perl_path\n";
}
# Add defines from Perl's ccflags; see PGAC_CHECK_PERL_EMBED_CCFLAGS
my @perl_embed_ccflags;
foreach my $f (split(" ", $Config{ccflags}))
{
if ( $f =~ /^-D[^_]/
|| $f =~ /^-D_USE_32BIT_TIME_T/)
if ($f =~ /^-D[^_]/)
{
$f =~ s/\-D//;
push(@perl_embed_ccflags, $f);
}
}
# Perl versions before 5.13.4 don't provide -D_USE_32BIT_TIME_T
# regardless of how they were built. On 32-bit Windows, assume
# such a version was built with a pre-MSVC-2005 compiler, and
# define the symbol anyway, so that we are compatible if we're
# being built with a later MSVC version.
push(@perl_embed_ccflags, '_USE_32BIT_TIME_T')
if $solution->{platform} eq 'Win32'
&& $Config{PERL_REVISION} == 5
&& ($Config{PERL_VERSION} < 13
|| ( $Config{PERL_VERSION} == 13
&& $Config{PERL_SUBVERSION} < 4));
# Also, a hack to prevent duplicate definitions of uid_t/gid_t
# hack to prevent duplicate definitions of uid_t/gid_t
push(@perl_embed_ccflags, 'PLPERL_HAVE_UID_GID');
# Windows offers several 32-bit ABIs. Perl is sensitive to
# sizeof(time_t), one of the ABI dimensions. To get 32-bit time_t,
# use "cl -D_USE_32BIT_TIME_T" or plain "gcc". For 64-bit time_t, use
# "gcc -D__MINGW_USE_VC2005_COMPAT" or plain "cl". Before MSVC 2005,
# plain "cl" chose 32-bit time_t. PostgreSQL doesn't support building
# with pre-MSVC-2005 compilers, but it does support linking to Perl
# built with such a compiler. MSVC-built Perl 5.13.4 and later report
# -D_USE_32BIT_TIME_T in $Config{ccflags} if applicable, but
# MinGW-built Perl never reports -D_USE_32BIT_TIME_T despite typically
# needing it. Ignore the $Config{ccflags} opinion about
# -D_USE_32BIT_TIME_T, and use a runtime test to deduce the ABI Perl
# expects. Specifically, test use of PL_modglobal, which maps to a
# PerlInterpreter field whose position depends on sizeof(time_t).
if ($solution->{platform} eq 'Win32')
{
my $source_file = 'conftest.c';
my $obj = 'conftest.obj';
my $exe = 'conftest.exe';
my @conftest = ($source_file, $obj, $exe);
push @unlink_on_exit, @conftest;
unlink $source_file;
open my $o, '>', $source_file
|| croak "Could not write to $source_file";
print $o '
/* compare to plperl.h */
#define __inline__ __inline
#define PERL_NO_GET_CONTEXT
#include <EXTERN.h>
#include <perl.h>
int
main(int argc, char **argv)
{
int dummy_argc = 1;
char *dummy_argv[1] = {""};
char *dummy_env[1] = {NULL};
static PerlInterpreter *interp;
PERL_SYS_INIT3(&dummy_argc, (char ***) &dummy_argv,
(char ***) &dummy_env);
interp = perl_alloc();
perl_construct(interp);
{
dTHX;
const char key[] = "dummy";
PL_exit_flags |= PERL_EXIT_DESTRUCT_END;
hv_store(PL_modglobal, key, sizeof(key) - 1, newSViv(1), 0);
return hv_fetch(PL_modglobal, key, sizeof(key) - 1, 0) == NULL;
}
}
';
close $o;
# Build $source_file with a given #define, and return a true value
# if a run of the resulting binary exits successfully.
my $try_define = sub {
my $define = shift;
unlink $obj, $exe;
my @cmd = (
'cl',
'-I' . $solution->{options}->{perl} . '/lib/CORE',
(map { "-D$_" } @perl_embed_ccflags, $define || ()),
$source_file,
'/link',
$perl_libs[0]);
my $compile_output = `@cmd 2>&1`;
-f $exe || die "Failed to build Perl test:\n$compile_output";
{
# Some builds exhibit runtime failure through Perl warning
# 'Can't spawn "conftest.exe"'; supress that.
no warnings;
# Disable error dialog boxes like we do in the postmaster.
# Here, we run code that triggers relevant errors.
use Win32API::File qw(SetErrorMode :SEM_);
my $oldmode = SetErrorMode(
SEM_FAILCRITICALERRORS | SEM_NOGPFAULTERRORBOX);
system(".\\$exe");
SetErrorMode($oldmode);
}
return !($? >> 8);
};
my $define_32bit_time = '_USE_32BIT_TIME_T';
my $ok_now = $try_define->(undef);
my $ok_32bit = $try_define->($define_32bit_time);
unlink @conftest;
if (!$ok_now && !$ok_32bit)
{
# Unsupported configuration. Since we used %Config from the
# Perl running the build scripts, this is expected if
# attempting to link with some other Perl.
die "Perl test fails with or without -D$define_32bit_time";
}
elsif ($ok_now && $ok_32bit)
{
# Resulting build may work, but it's especially important to
# verify with "vcregress plcheck". A refined test may avoid
# this outcome.
warn "Perl test passes with or without -D$define_32bit_time";
}
elsif ($ok_32bit)
{
push(@perl_embed_ccflags, $define_32bit_time);
} # else $ok_now, hence no flag required
}
print "CFLAGS recommended by Perl: $Config{ccflags}\n";
print "CFLAGS to compile embedded Perl: ",
(join ' ', map { "-D$_" } @perl_embed_ccflags), "\n";
foreach my $f (@perl_embed_ccflags)
{
$plperl->AddDefine($f);
@ -605,20 +726,6 @@ sub mkvcbuild
die 'Failed to create plperl_opmask.h' . "\n";
}
}
$plperl->AddReference($postgres);
my $perl_path = $solution->{options}->{perl} . '\lib\CORE\*perl*';
# ActivePerl 5.16 provided perl516.lib; 5.18 provided libperl518.a
my @perl_libs =
grep { /perl\d+\.lib$|libperl\d+\.a$/ } glob($perl_path);
if (@perl_libs == 1)
{
$plperl->AddLibrary($perl_libs[0]);
}
else
{
die
"could not identify perl library version matching pattern $perl_path\n";
}
# Add transform module dependent on plperl
my $hstore_plperl = AddTransformModule(
@ -965,4 +1072,9 @@ sub AdjustModule
}
}
END
{
unlink @unlink_on_exit;
}
1;