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Diffstat (limited to 'src/tools/msvc/gendef.pl')
| -rw-r--r-- | src/tools/msvc/gendef.pl | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/src/tools/msvc/gendef.pl b/src/tools/msvc/gendef.pl new file mode 100644 index 0000000..cf83d7d --- /dev/null +++ b/src/tools/msvc/gendef.pl @@ -0,0 +1,205 @@ + +# Copyright (c) 2021-2023, PostgreSQL Global Development Group + +use strict; +use warnings; +use List::Util qw(min); +use Getopt::Long; + +my @def; + +# +# Script that generates a .DEF file for all objects in a directory +# +# src/tools/msvc/gendef.pl +# + +# Given a symbol file path, loops over its contents +# and returns a list of symbols of interest as a dictionary +# of 'symbolname' -> symtype, where symtype is: +# +# 0 a CODE symbol, left undecorated in the .DEF +# 1 A DATA symbol, i.e. global var export +# +sub extract_syms +{ + my ($symfile, $def) = @_; + open(my $f, '<', $symfile) || die "Could not open $symfile for $_: $!\n"; + while (<$f>) + { + + # Expected symbol lines look like: + # + # 0 1 2 3 4 5 6 + # IDX SYMBOL SECT SYMTYPE SYMSTATIC SYMNAME + # ------------------------------------------------------------------------ + # 02E 00000130 SECTA notype External | _standbyState + # 02F 00000009 SECT9 notype Static | _LocalRecoveryInProgress + # 064 00000020 SECTC notype () Static | _XLogCheckBuffer + # 065 00000000 UNDEF notype () External | _BufferGetTag + # + # See http://msdn.microsoft.com/en-us/library/b842y285.aspx + # + # We're not interested in the symbol index or offset. + # + # SECT[ION] is only examined to see whether the symbol is defined in a + # COFF section of the local object file; if UNDEF, it's a symbol to be + # resolved at link time from another object so we can't export it. + # + # SYMTYPE is always notype for C symbols as there's no typeinfo and no + # way to get the symbol type from name (de)mangling. However, we care + # if "notype" is suffixed by "()" or not. The presence of () means the + # symbol is a function, the absence means it isn't. + # + # SYMSTATIC indicates whether it's a compilation-unit local "static" + # symbol ("Static"), or whether it's available for use from other + # compilation units ("External"). We export all symbols that aren't + # static as part of the whole program DLL interface to produce UNIX-like + # default linkage. + # + # SYMNAME is, obviously, the symbol name. The leading underscore + # indicates that the _cdecl calling convention is used. See + # http://www.unixwiz.net/techtips/win32-callconv.html + # http://www.codeproject.com/Articles/1388/Calling-Conventions-Demystified + # + s/notype \(\)/func/g; + s/notype/data/g; + + my @pieces = split; + + # Skip file and section headers and other non-symbol entries + next unless defined($pieces[0]) and $pieces[0] =~ /^[A-F0-9]{3,}$/; + + # Skip blank symbol names + next unless $pieces[6]; + + # Skip externs used from another compilation unit + next if ($pieces[2] eq "UNDEF"); + + # Skip static symbols + next unless ($pieces[4] eq "External"); + + # Skip some more MSVC-generated crud + next if $pieces[6] =~ /^@/; + next if $pieces[6] =~ /^\(/; + + # __real and __xmm are out-of-line floating point literals and + # (for __xmm) their SIMD equivalents. They shouldn't be part + # of the DLL interface. + next if $pieces[6] =~ /^__real/; + next if $pieces[6] =~ /^__xmm/; + + # __imp entries are imports from other DLLs, eg __imp__malloc . + # (We should never have one of these that hasn't already been skipped + # by the UNDEF test above, though). + next if $pieces[6] =~ /^__imp/; + + # More under-documented internal crud + next if $pieces[6] =~ /NULL_THUNK_DATA$/; + next if $pieces[6] =~ /^__IMPORT_DESCRIPTOR/; + next if $pieces[6] =~ /^__NULL_IMPORT/; + + # Skip string literals + next if $pieces[6] =~ /^\?\?_C/; + + # We assume that if a symbol is defined as data, then as a function, + # the linker will reject the binary anyway. So it's OK to just pick + # whatever came last. + $def->{ $pieces[6] } = $pieces[3]; + } + close($f); + return; +} + +sub writedef +{ + my ($deffile, $arch, $def) = @_; + open(my $fh, '>', $deffile) || die "Could not write to $deffile\n"; + print $fh "EXPORTS\n"; + foreach my $f (sort keys %{$def}) + { + my $isdata = $def->{$f} eq 'data'; + + # Strip the leading underscore for win32, but not x64 + $f =~ s/^_// + unless ($arch eq "x86_64"); + + # Emit just the name if it's a function symbol, or emit the name + # decorated with the DATA option for variables. + if ($isdata) + { + print $fh " $f DATA\n"; + } + else + { + print $fh " $f\n"; + } + } + close($fh); + return; +} + + +sub usage +{ + die("Usage: gendef.pl --arch <arch> --deffile <deffile> --tempdir <tempdir> files-or-directories\n" + . " arch: x86 | x86_64\n" + . " deffile: path of the generated file\n" + . " tempdir: directory for temporary files\n" + . " files or directories: object files or directory containing object files\n" + ); +} + +my $arch; +my $deffile; +my $tempdir = '.'; + +GetOptions( + 'arch:s' => \$arch, + 'deffile:s' => \$deffile, + 'tempdir:s' => \$tempdir,) or usage(); + +usage("arch: $arch") + unless ($arch eq 'x86' || $arch eq 'x86_64'); + +my @files; + +foreach my $in (@ARGV) +{ + if (-d $in) + { + push @files, glob "$in/*.obj"; + } + else + { + push @files, $in; + } +} + +# if the def file exists and is newer than all input object files, skip +# its creation +if (-f $deffile + && (-M $deffile < min(map { -M } @files))) +{ + print "Not re-generating $deffile, file already exists.\n"; + exit(0); +} + +print "Generating $deffile in tempdir $tempdir\n"; + +my %def = (); + +my $symfile = "$tempdir/all.sym"; +my $tmpfile = "$tempdir/tmp.sym"; +mkdir($tempdir) unless -d $tempdir; + +my $cmd = "dumpbin /nologo /symbols /out:$tmpfile " . join(' ', @files); + +system($cmd) && die "Could not call dumpbin"; +rename($tmpfile, $symfile); +extract_syms($symfile, \%def); +print "\n"; + +writedef($deffile, $arch, \%def); + +print "Generated " . scalar(keys(%def)) . " symbols\n"; |