1#!/usr/bin/perl -w 2 3# This script takes two arguments, a version script and a dynamic library 4# (in that order), and prints a list of symbols to be exported from the 5# library. 6# It expects a 'nm' with the POSIX '-P' option, but everyone has one of 7# those, right? It also expects that symbol names have a leading underscore, 8# which is somewhat less likely. 9 10use File::Glob ':glob'; 11use FileHandle; 12use IPC::Open2; 13 14# The glob patterns that are to be applied to the demangled name 15my @cxx_globs = (); 16# The glob patterns that apply directly to the name in the .o files 17my @globs = (); 18# The patterns for local variables (usually just '*'). 19my @ignored = (); 20 21########## 22# Fill in the various glob arrays. 23 24# The next pattern will go into this array. 25my $glob = \@globs; 26my $symvers = shift; 27 28open F,$symvers or die $!; 29 30while (<F>) { 31 chomp; 32 # Lines of the form '} SOME_VERSION_NAME_1.0;' 33 if (/^[ \t]*\}[ \tA-Z0-9_.a-z]*;[ \t]*$/) { 34 $glob = \@globs; 35 next; 36 } 37 # Comment and blank lines 38 next if (/^[ \t]*\#/); 39 next if (/^[ \t]*$/); 40 # Lines of the form 'SOME_VERSION_NAME_1.1 {' 41 next if (/^[A-Z0-9_. \t]*{$/); 42 # Ignore 'global:' 43 next if (/^[ \t]*global:$/); 44 # After 'local:', globs should be ignored, they won't be exported. 45 if (/^[ \t]*local:$/) { 46 $glob = \@ignored; 47 next; 48 } 49 # After 'extern "C++"', globs are C++ patterns 50 if (/^[ \t]*extern \"C\+\+\"[ \t]*$/) { 51 $glob = \@cxx_globs; 52 next; 53 } 54 # Catch globs. Note that '{}' is not allowed in globs by this script, 55 # so only '*' and '?' and '[]' are available. 56 if (/^[ \t]*([^ \t;{}#]+);?[ \t]*$/) { 57 my $ptn = $1; 58 # Turn the glob into a regex by replacing '*' with '.*'. 59 $ptn =~ s/\*/.*/g; 60 # And replacing '?' with '.'. 61 $ptn =~ s/\?/./g; 62 push @$glob,$ptn; 63 next; 64 } 65 # Important sanity check. This script can't handle lots of formats 66 # that GNU ld can, so be sure to error out if one is seen! 67 die "strange line `$_'"; 68} 69close F; 70 71# Make 'if (1)' for debugging. 72if (0) { 73 print "cxx:\n"; 74 (printf "%s\n",$_) foreach (@cxx_globs); 75 print "globs:\n"; 76 (printf "%s\n", $_) foreach (@globs); 77 print "ignored:\n"; 78 (printf "%s\n", $_) foreach (@ignored); 79} 80 81########## 82# Combine the arrays into single regular expressions 83# This cuts the time required from about 30 seconds to about 0.5 seconds. 84 85my $glob_regex = '^_(' . (join '|',@globs) . ')$'; 86my $cxx_regex = (join '|',@cxx_globs); 87 88########## 89# Get all the symbols from the library, match them, and add them to a hash. 90 91my %export_hash = (); 92my $nm = $ENV{'NM_FOR_TARGET'} || "nm"; 93# Process each symbol. 94print STDERR $nm.' -P '.(join ' ',@ARGV).'|'; 95open NM,$nm.' -P '.(join ' ',@ARGV).'|' or die $!; 96# Talk to c++filt through a pair of file descriptors. 97open2(*FILTIN, *FILTOUT, "c++filt -_") or die $!; 98NAME: while (<NM>) { 99 my $i; 100 chomp; 101 102 # nm prints out stuff at the start, ignore it. 103 next if (/^$/); 104 next if (/:$/); 105 # Ignore undefined and local symbols. 106 next if (/^([^ ]+) [Ua-z] /); 107 108 # GCC does not export construction vtables from shared libraries. 109 # However the symbols are marked hidden, for Darwin that makes them 110 # also external "private_extern", which means that they show up in 111 # this list. When ld64 encounters them it generates a warning that 112 # they cannot be exported, so trim them from the set now. 113 next if (/^construction vtable.*$/); 114 next if (/^__ZTC.*$/); 115 116 # $sym is the name of the symbol, $noeh_sym is the same thing with 117 # any '.eh' suffix removed. 118 die "unknown nm output $_" if (! /^([^ ]+) [A-Z] /); 119 my $sym = $1; 120 my $noeh_sym = $sym; 121 $noeh_sym =~ s/\.eh$//; 122 123 # Maybe it matches one of the patterns based on the symbol in the .o file. 124 if ($noeh_sym =~ /$glob_regex/) { 125 $export_hash{$sym} = 1; 126 next NAME; 127 } 128 129 # No? Well, maybe its demangled form matches one of those patterns. 130 printf FILTOUT "%s\n",$noeh_sym; 131 my $dem = <FILTIN>; 132 chomp $dem; 133 if ($dem =~ /$cxx_regex/) { 134 $export_hash{$sym} = 2; 135 next NAME; 136 } 137 138 # No? Well, then ignore it. 139} 140close NM or die "nm error"; 141close FILTOUT or die "c++filt error"; 142close FILTIN or die "c++filt error"; 143 144########## 145# Print out the export file 146 147# Print information about generating this file 148print "# This is a generated file.\n"; 149print "# It was generated by:\n"; 150printf "# %s %s %s\n", $0, $symvers, (join ' ',@ARGV); 151 152foreach my $i (keys %export_hash) { 153 printf "%s\n",$i or die; 154} 155