use strict;
use warnings;
-my $symbols = {};
+use constant WARNING_SIZE => 512;
-# Scan output of "nm -o -g bin/blib.a" and build up symbol cross-ref table
+my $symtab = {};
+
+# Scan output of "objdump -w -t bin/blib.a" and build up symbol table
#
+my $object;
while ( <> ) {
chomp;
- ( my $object, my $type, my $symbol ) = /^.*?:(.*?\.o):.*?\s(\S)\s(.*)$/;
- my $category = $type eq 'U' ? "requires" : "provides";
- $symbols->{$symbol}->{$category}->{$object} = 1;
+ 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
#
-while ( ( my $symbol, my $info ) = each %$symbols ) {
- $info->{requires}->{LINKER} = 1 if $symbol =~ /^obj_/;
+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,
+ };
+}
+
+# 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} = $info->{section};
+ }
+ }
}
-$symbols->{$_}->{provides}->{LINKER} = 1
- foreach qw ( _prefix _eprefix _decompress _edecompress _text
- _etext _data _edata _bss _ebss _end device_drivers
- device_drivers_end bus_drivers bus_drivers_end
- type_drivers type_drivers_end console_drivers
- console_drivers_end post_reloc_fns post_reloc_fns_end
- init_fns init_fns_end );
-# Check for multiply defined, never-defined and unused symbols
+# Check for multiply defined, never-defined and unused global symbols
#
my $problems = {};
-while ( ( my $symbol, my $info ) = each %$symbols ) {
+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 ) {
- # No object provides this symbol
+ if ( ( @requires > 0 ) && ( @provides == 0 ) && ( @shares == 0 ) ) {
+ # No object provides this symbol, but some objects require it.
$problems->{$_}->{nonexistent}->{$symbol} = 1 foreach @requires;
- } elsif ( @provides > 1 ) {
- # Symbol defined in multiple objects
+ }
+
+ 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 ( $info->{provides}->{$provide} =~ /^\.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;
}
- if ( @requires == 0 ) {
- # Symbol not required
- $problems->{$_}->{unused}->{$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}->{$symbol} = 1;
+ }
}
}
my @nonexistent = sort keys %{$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 $object }
- keys %{$symbols->{$symbol}->{provides}};
+ keys %{$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";