From c3290aae5406e334830009cf5ce8d64d551e0f58 Mon Sep 17 00:00:00 2001 From: Michael Brown Date: Tue, 17 Jul 2007 01:15:39 +0100 Subject: [PATCH] Use objdump -t for symcheck; it allows us to take the symbol section into account (and so remove the false positives due to .tbl.* symbols). --- src/Makefile.housekeeping | 2 +- src/util/symcheck.pl | 96 ++++++++++++++++++++++++--------------- 2 files changed, 61 insertions(+), 37 deletions(-) diff --git a/src/Makefile.housekeeping b/src/Makefile.housekeeping index ff52de1d..ccf4dc11 100644 --- a/src/Makefile.housekeeping +++ b/src/Makefile.housekeeping @@ -454,7 +454,7 @@ CLEANUP += TAGS* # SYMTAB = $(BIN)/symtab $(SYMTAB) : $(BLIB) - $(NM) -o -S $< > $@ + $(OBJDUMP) -w -t $< > $@ CLEANUP += $(BIN)/symtab diff --git a/src/util/symcheck.pl b/src/util/symcheck.pl index 63736589..6e46ae46 100755 --- a/src/util/symcheck.pl +++ b/src/util/symcheck.pl @@ -7,18 +7,34 @@ use constant WARNING_SIZE => 512; my $symtab = {}; -# Scan output of "nm -o -S bin/blib.a" and build up symbol table +# Scan output of "objdump -w -t bin/blib.a" and build up symbol table # +my $object; while ( <> ) { chomp; - ( my $object, undef, my $value, undef, my $size, my $type, my $symbol ) - = /^.*?:(.*?\.o):((\S+)(\s+(\S+))?)?\s+(\S)\s+(\S+)$/; - $symtab->{$object}->{$symbol} = { - global => ( $type eq uc $type ), - type => ( $type ), - value => ( $value ? hex ( $value ) : 0 ), - size => ( $size ? hex ( $size ) : 0 ), - }; + if ( /^In archive/ ) { + # Do nothing + } elsif ( /^$/ ) { + # Do nothing + } elsif ( /^(\S+\.o):\s+file format/ ) { + $object = $1; + } elsif ( /^SYMBOL TABLE:/ ) { + # Do nothing + } elsif ( /^([0-9a-fA-F]+)\s(l|g|\s)......\s(\S+)\s+([0-9a-fA-F]+)\s+(\S+)$/ ) { + my $value = $1; + my $scope = $2; + my $section = $3; + my $size = $4; + my $symbol = $5; + $symtab->{$object}->{$symbol} = { + global => ( $scope ne "l" ), + section => ( $section eq "*UND*" ? undef : $section ), + value => ( $value ? hex ( $value ) : 0 ), + size => ( $size ? hex ( $size ) : 0 ), + }; + } else { + die "Unrecognized line \"$_\""; + } } # Add symbols that we know will be generated or required by the linker @@ -29,16 +45,26 @@ foreach my $object ( keys %$symtab ) { $obj_symbol =~ s/\W/_/g; $symtab->{LINKER}->{$obj_symbol} = { global => 1, - type => 'U', + section => undef, value => 0, size => 0, }; } -foreach my $link_sym qw ( _prefix _eprefix _decompress _edecompress _text - _etext _data _edata _bss _ebss _end ) { +foreach my $link_sym qw ( __prefix _prefix _prefix_load_offset + _prefix_size _prefix_progbits_size _prefix_size_pgh + __text16 _text16 _text16_load_offset + _text16_size _text16_progbits_size _text16_size_pgh + __data16 _data16 _data16_load_offset + _data16_size _data16_progbits_size _data16_size_pgh + __text _text __data _data _textdata_load_offset + _textdata_size _textdata_progbits_size + __rodata __bss _end + _payload_offset _max_align + _load_size _load_size_pgh _load_size_sect + pci_vendor_id pci_device_id ) { $symtab->{LINKER}->{$link_sym} = { global => 1, - type => 'A', + section => '*ABS*', value => 0, size => 0, }; @@ -51,9 +77,15 @@ my $globals = {}; while ( ( my $object, my $symbols ) = each %$symtab ) { while ( ( my $symbol, my $info ) = each %$symbols ) { if ( $info->{global} ) { - my $category = ( ( $info->{type} eq 'U' ? "requires" : - ( $info->{type} eq 'C' ? "shares" : "provides" ) ) ); - $globals->{$symbol}->{$category}->{$object} = 1; + my $category; + if ( ! defined $info->{section} ) { + $category = "requires"; + } elsif ( $info->{section} eq "*COM*" ) { + $category = "shares"; + } else { + $category = "provides"; + } + $globals->{$symbol}->{$category}->{$object} = $info->{section}; } } } @@ -66,26 +98,22 @@ while ( ( my $symbol, my $info ) = each %$globals ) { my @requires = keys %{$info->{requires}}; my @shares = keys %{$info->{shares}}; - if ( ( @provides == 0 ) && ( @shares == 1 ) ) { - # A symbol "shared" by just a single file is actually being - # provided by that file; it just doesn't have an initialiser. - @provides = @shares; - @shares = (); - } - - if ( ( @requires > 0 ) && ( @provides == 0 ) ) { + if ( ( @requires > 0 ) && ( @provides == 0 ) && ( @shares == 0 ) ) { # No object provides this symbol, but some objects require it. $problems->{$_}->{nonexistent}->{$symbol} = 1 foreach @requires; } if ( ( @requires == 0 ) && ( @provides > 0 ) ) { # No object requires this symbol, but some objects provide it. - $problems->{$_}->{unused}->{$symbol} = 1 foreach @provides; - } - - if ( ( @shares > 0 ) && ( @requires > 0 ) ) { - # A shared symbol is being referenced from another object - $problems->{$_}->{shared}->{$symbol} = 1 foreach @requires; + foreach my $provide ( @provides ) { + if ( $provide eq "LINKER" ) { + # Linker-provided symbols are exempt from this check. + } elsif ( $info->{provides}->{$provide} =~ /^\.tbl\./ ) { + # Linker tables are exempt from this check. + } else { + $problems->{$provide}->{unused}->{$symbol} = 1; + } + } } if ( ( @shares > 0 ) && ( @provides > 0 ) ) { @@ -93,11 +121,6 @@ while ( ( my $symbol, my $info ) = each %$globals ) { $problems->{$_}->{shared}->{$symbol} = 1 foreach @provides; } - if ( ( @shares > 0 ) && ! ( $symbol =~ /^_shared_/ ) ) { - # A shared symbol is not declared via __shared - $problems->{$_}->{shared}->{$symbol} = 1 foreach @shares; - } - if ( @provides > 1 ) { # A non-shared symbol is defined in multiple objects $problems->{$_}->{multiples}->{$symbol} = 1 foreach @provides; @@ -110,7 +133,8 @@ while ( ( my $symbol, my $info ) = each %$globals ) { while ( ( my $object, my $symbols ) = each %$symtab ) { while ( ( my $symbol, my $info ) = each %$symbols ) { if ( ( ! $info->{global} ) && - ( ! ( $info->{type} =~ /^(t|r)$/ ) ) && + ( ( defined $info->{section} ) && + ! ( $info->{section} =~ /^(\.text|\.rodata)/ ) ) && ( $info->{size} >= WARNING_SIZE ) ) { $problems->{$object}->{large}->{$symbol} = 1; }