gcc/libstdc++-v3/scripts/make_exports.pl

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#!/usr/bin/perl -w
# This script takes two arguments, a version script and a dynamic library
# (in that order), and prints a list of symbols to be exported from the
# library.
# It expects a 'nm' with the POSIX '-P' option, but everyone has one of
# those, right? It also expects that symbol names have a leading underscore,
# which is somewhat less likely.
use File::Glob ':glob';
use FileHandle;
use IPC::Open2;
# The glob patterns that are to be applied to the demangled name
my @cxx_globs = ();
# The glob patterns that apply directly to the name in the .o files
my @globs = ();
# The patterns for local variables (usually just '*').
my @ignored = ();
##########
# Fill in the various glob arrays.
# The next pattern will go into this array.
my $glob = \@globs;
my $symvers = shift;
open F,$symvers or die $!;
while (<F>) {
chomp;
# Lines of the form '} SOME_VERSION_NAME_1.0;'
if (/^[ \t]*\}[ \tA-Z0-9_.a-z]*;[ \t]*$/) {
$glob = \@globs;
next;
}
# Comment and blank lines
next if (/^[ \t]*\#/);
next if (/^[ \t]*$/);
# Lines of the form 'SOME_VERSION_NAME_1.1 {'
next if (/^[A-Z0-9_. \t]*{$/);
# Ignore 'global:'
next if (/^[ \t]*global:$/);
# After 'local:', globs should be ignored, they won't be exported.
if (/^[ \t]*local:$/) {
$glob = \@ignored;
next;
}
# After 'extern "C++"', globs are C++ patterns
if (/^[ \t]*extern \"C\+\+\"[ \t]*$/) {
$glob = \@cxx_globs;
next;
}
# Catch globs. Note that '{}' is not allowed in globs by this script,
# so only '*' and '[]' are available.
if (/^[ \t]*([^ \t;{}#]+);?[ \t]*$/) {
my $ptn = $1;
# Turn the glob into a regex by replacing '*' with '.*'.
$ptn =~ s/\*/\.\*/g;
push @$glob,$ptn;
next;
}
# Important sanity check. This script can't handle lots of formats
# that GNU ld can, so be sure to error out if one is seen!
die "strange line `$_'";
}
close F;
# Make 'if (1)' for debugging.
if (0) {
print "cxx:\n";
(printf "%s\n",$_) foreach (@cxx_globs);
print "globs:\n";
(printf "%s\n", $_) foreach (@globs);
print "ignored:\n";
(printf "%s\n", $_) foreach (@ignored);
}
##########
# Combine the arrays into single regular expressions
# This cuts the time required from about 30 seconds to about 0.5 seconds.
my $glob_regex = '^_(' . (join '|',@globs) . ')$';
my $cxx_regex = (join '|',@cxx_globs);
##########
# Get all the symbols from the library, match them, and add them to a hash.
my %export_hash = ();
my $nm = $ENV{'NM_FOR_TARGET'} || "nm";
# Process each symbol.
print STDERR $nm.' -P '.(join ' ',@ARGV).'|';
open NM,$nm.' -P '.(join ' ',@ARGV).'|' or die $!;
# Talk to c++filt through a pair of file descriptors.
open2(*FILTIN, *FILTOUT, "c++filt -_") or die $!;
NAME: while (<NM>) {
my $i;
chomp;
# nm prints out stuff at the start, ignore it.
next if (/^$/);
next if (/:$/);
# Ignore undefined and local symbols.
next if (/^([^ ]+) [Ua-z] /);
# GCC does not export construction vtables from shared libraries.
# However the symbols are marked hidden, for Darwin that makes them
# also external "private_extern", which means that they show up in
# this list. When ld64 encounters them it generates a warning that
# they cannot be exported, so trim them from the set now.
next if (/^construction vtable.*$/);
next if (/^__ZTC.*$/);
# $sym is the name of the symbol, $noeh_sym is the same thing with
# any '.eh' suffix removed.
die "unknown nm output $_" if (! /^([^ ]+) [A-Z] /);
my $sym = $1;
my $noeh_sym = $sym;
$noeh_sym =~ s/\.eh$//;
# Maybe it matches one of the patterns based on the symbol in the .o file.
if ($noeh_sym =~ /$glob_regex/) {
$export_hash{$sym} = 1;
next NAME;
}
# No? Well, maybe its demangled form matches one of those patterns.
printf FILTOUT "%s\n",$noeh_sym;
my $dem = <FILTIN>;
chomp $dem;
if ($dem =~ /$cxx_regex/) {
$export_hash{$sym} = 2;
next NAME;
}
# No? Well, then ignore it.
}
close NM or die "nm error";
close FILTOUT or die "c++filt error";
close FILTIN or die "c++filt error";
##########
# Print out the export file
# Print information about generating this file
print "# This is a generated file.\n";
print "# It was generated by:\n";
printf "# %s %s %s\n", $0, $symvers, (join ' ',@ARGV);
foreach my $i (keys %export_hash) {
printf "%s\n",$i or die;
}