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#!/usr/bin/perl -w
use strict;
use warnings;
use constant WARNING_SIZE => 512;
my $symtab = {};
# Scan output of "objdump -w -t bin/blib.a" and build up symbol table
#
my $object;
while ( <> ) {
chomp;
if ( /^In archive/ ) {
# Do nothing
} elsif ( /^$/ ) {
# 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
#
foreach my $object ( keys %$symtab ) {
my $obj_symbol = "obj_$object";
$obj_symbol =~ s/\.o$//;
$obj_symbol =~ s/\W/_/g;
$symtab->{LINKER}->{$obj_symbol} = {
global => 1,
section => undef,
value => 0,
size => 0,
};
}
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,
section => '*ABS*',
value => 0,
size => 0,
};
}
# Add symbols that we know will be used by the debug system
#
foreach my $debug_sym qw ( dbg_autocolourise dbg_decolourise
dbg_hex_dump_da ) {
$symtab->{DEBUG}->{$debug_sym} = {
global => 1,
section => undef,
value => 0,
size => 0,
};
}
# Build up requires, provides and shares symbol tables for global
# symbols
#
my $globals = {};
while ( ( my $object, my $symbols ) = each %$symtab ) {
while ( ( my $symbol, my $info ) = each %$symbols ) {
if ( $info->{global} ) {
my $category;
if ( ! defined $info->{section} ) {
$category = "requires";
} elsif ( $info->{section} eq "*COM*" ) {
$category = "shares";
} else {
$category = "provides";
}
$globals->{$symbol}->{$category}->{$object} = 1;
}
}
}
# Check for multiply defined, never-defined and unused global symbols
#
my $problems = {};
while ( ( my $symbol, my $info ) = each %$globals ) {
my @provides = keys %{$info->{provides}};
my @requires = keys %{$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 ) && ( @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.
foreach my $provide ( @provides ) {
if ( $provide eq "LINKER" ) {
# Linker-provided symbols are exempt from this check.
} elsif ( $symtab->{$provide}->{$symbol}->{section} =~ /^\.tbl\./ ) {
# Linker tables are exempt from this check.
} else {
$problems->{$provide}->{unused}->{$symbol} = 1;
}
}
}
if ( ( @shares > 0 ) && ( @provides > 0 ) ) {
# A shared symbol is being initialised by an object
$problems->{$_}->{shared}->{$symbol} = 1 foreach @provides;
}
if ( @provides > 1 ) {
# A non-shared symbol is defined in multiple objects
$problems->{$_}->{multiples}->{$symbol} = 1 foreach @provides;
}
}
# Check for excessively large local symbols. Text and rodata symbols
# are exempt from this check
#
while ( ( my $object, my $symbols ) = each %$symtab ) {
while ( ( my $symbol, my $info ) = each %$symbols ) {
if ( ( ! $info->{global} ) &&
( ( defined $info->{section} ) &&
! ( $info->{section} =~ /^(\.text|\.rodata)/ ) ) &&
( $info->{size} >= WARNING_SIZE ) ) {
$problems->{$object}->{large}->{$symbol} = 1;
}
}
}
# Print out error messages
#
my $errors = 0;
my $warnings = 0;
foreach my $object ( sort keys %$problems ) {
my @nonexistent = sort keys %{$problems->{$object}->{nonexistent}};
my @multiples = sort keys %{$problems->{$object}->{multiples}};
my @unused = sort keys %{$problems->{$object}->{unused}};
my @shared = sort keys %{$problems->{$object}->{shared}};
my @large = sort keys %{$problems->{$object}->{large}};
print "WARN $object provides unused symbol $_\n" foreach @unused;
$warnings += @unused;
print "WARN $object has large static symbol $_\n" foreach @large;
$warnings += @large;
print "ERR $object requires non-existent symbol $_\n" foreach @nonexistent;
$errors += @nonexistent;
foreach my $symbol ( @multiples ) {
my @other_objects = sort grep { $_ ne $object }
keys %{$globals->{$symbol}->{provides}};
print "ERR $object provides symbol $symbol"
." (also provided by @other_objects)\n";
}
$errors += @multiples;
print "ERR $object misuses shared symbol $_\n" foreach @shared;
}
print "$errors error(s), $warnings warning(s)\n";
exit ( $errors ? 1 : 0 );
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