gecko-dev/tools/module-deps/find-unused-exports.pl

270 строки
7.1 KiB
Perl

#!/bin/env perl
use strict;
my $export_file;
my @import_files;
my $show_class_usage = 0;
my $show_function_usage = 0;
my $infrequent_use_threshold = 1;
# first argument is the file that's exporting
# all further arguments are the input files
my $arg;
foreach $arg (@ARGV) {
if ($arg =~ /^-(.*)/) {
$show_class_usage=1 if ($1 eq "c");
$show_function_usage=1 if ($1 eq "f");
}
elsif (!$export_file) {
$export_file = $arg;
} else {
push @import_files, $arg;
}
}
if (!$export_file || $#import_files == -1) {
print "$export_file, $#import_files\n";
print "Usage: $ARGV[0] <exporter>.dll [ importer [ importer ..]]\n";
print " Builds up a list of exporters from <exporter>.dll,\n";
print " and then lists all exports that are rarely or never used.\n";
exit;
}
open EXPORTS, "dumpbin /exports $export_file|";
# $demangle{foo} is the demangled name of "foo"
my %demangle;
# $import_count{foo} is the number of exports of "foo"
my %import_count;
my %last_consumer_of;
my $found_exports;
while (<EXPORTS>) {
# format is
# ordinal hint RVA? name
if ($found_exports) {
# break up the words
my @words = split /\s+/;
next if ($#words != 4);
my $ordinal = $words[1];
my $name = $words[4];
$import_count{$name} = 0;
} elsif (/ordinal\s+hint\s+RVA/) {
$found_exports = 1;
}
}
close EXPORTS;
#
# now read in all imports, and ++ the imports from the exported file
#
my $filename;
foreach $filename (@import_files) {
print STDERR "gathering data for $filename\n";
open IMPORTS, "dumpbin /imports $filename|";
my $current_import_dll;
my $awaiting_import_dll;
my $importing_from;
my $awaiting_import_header;
while (<IMPORTS>) {
chop;
if (/Dump of file ([^\s]+)/) {
$awaiting_import_dll = 0;
$current_import_dll = $1;
#print STDERR "Found imports for $current_import_dll\n";
} elsif (/Section contains the following imports/) {
$awaiting_import_dll = 1;
} elsif ($awaiting_import_dll && /^\s+([\w\.]+)$/) {
$importing_from = $1;
$awaiting_import_dll = 0;
$awaiting_import_header = 1;
# print STDERR "$current_import_dll: Importing from $importing_from\n";
} elsif ($awaiting_import_header) {
if ($_ eq "") {
$awaiting_import_header = 0;
}
# print STDERR "...Skipped past header, starting imports\n" if (!$awaiting_import_header);
} else {
if ($_ eq "") {
$awaiting_import_dll = 1;
next;
}
if ($export_file eq $importing_from) {
# must be an import line
my @imports = split /\s+/;
next if ($#imports != 2);
my $func = $imports[2];
#print STDERR "... importing $func from $export_file\n";
$import_count{$func}++;
$last_consumer_of{$func} = $current_import_dll;
# print STDERR "Got import $importing_from\[$imports[2]\]\n";
}
}
}
close IMPORTS;
}
my $func;
my @funcs_to_demangle;
print STDERR "finding infrequently imported symbols..\n";
foreach $func (sort keys %import_count) {
# we need to demangle all symbols if we're showing unused classes
# otherwise, we only need to demangle infrequently-used symbols
if ($show_class_usage ||
$import_count{$func} <= $infrequent_use_threshold) {
push @funcs_to_demangle, $func;
} else {
#print STDERR "Found $import_count{$func} consumers of $func\n";
}
}
print STDERR "Demangling..$#funcs_to_demangle unused symbols\n";
my $max_per_run = 20;
my $demangle_queue;
my $count = 0;
while ($func = pop @funcs_to_demangle) {
# skip functions that are used often
#next if ($import_count{$func} > 1);
$count++;
$demangle_queue .= " $func";
if ($count == $max_per_run || ($#funcs_to_demangle == 0)) {
# set up the initial slot where the demangled name goes
open UNDNAME, "undname -f $demangle_queue|";
while (<UNDNAME>) {
chop;
# print STDERR "Got result $_\n";
if (/\s*(\S+)\s*==\s*(.*)$/) {
# print STDERR"succesfully demangled $1 to $2\n";
$demangle{$1} = $2;
} else {
$demangle{$1} = $1;
}
}
close UNDNAME;
$demangle_queue = "";
$count = 0;
}
}
print STDERR "Done.\n";
my %class_methods; # number of methods
my %class_method_unused; # number of unused methods in this class
my %class_method_infreq; # number of infrequently-used methods
my %class_method_used; # number of used method
my %multiple_consumers; # if a class is in here, it has multiple consumers
my %last_consumer_of_class; # last DLL to use this class
foreach $func (sort keys %demangle) {
# skip vtables, they don't matter
next if ($demangle{$func} =~ /vftable/);
next if ($demangle{$func} =~ /vbtable/);
my ($class) = ($demangle{$func} =~ /(\S+)::\S+/);
# gather general class info, no matter what the usage
if ($class) {
$class_methods{$class}++;
$multiple_consumers{$class} = 1 if ($import_count{$func} > 1);
}
# never used
if ($import_count{$func} == 0) {
$class_method_unused{$class}++ if ($class);
print "$demangle{$func}: No importers\n" if ($show_function_usage);
}
# used, but only by a few consumers
elsif ($import_count{$func} <= $infrequent_use_threshold) {
print "$demangle{$func}: $import_count{$func} consumer(s) ($last_consumer_of{$func})\n" if ($show_function_usage);
&gather_class_info($class, $func) if ($class);
}
# used by more than one consumer
else {
$class_method_used{$class}++ if ($class);
}
}
&show_class_usage() if ($show_class_usage);
sub show_class_usage() {
print "Classes that might be worth trimming:\n";
my $class;
foreach $class (sort keys %class_methods) {
# no methods are used
if ($class_method_unused{$class} == $class_methods{$class}) {
print "$class is never used! ($class_methods{$class} methods)\n";
}
# all methods are used
elsif ($class_method_used{$class} == $class_methods{$class}) {
# print "$class is well-used\n";
}
# only report classes that less than 50% used
elsif ($class_method_unused{$class}*2 > $class_methods{$class}) {
print "$class: $class_methods{$class} methods, mostly unused.\n";
print " Used: $class_method_used{$class}";
print " ($class_method_infreq{$class} are used by few consumers)"
if ($class_method_infreq{$class});
print "\n";
print " Unused: $class_method_unused{$class}\n";
if (!$multiple_consumers{$class}) {
print " Suggest moving $class into $last_consumer_of_class{$class} (the only consumer)\n";
}
}
}
}
sub gather_class_info() {
my ($class, $func) = @_;
$class_method_infreq{$class}++;
$class_method_used{$class}++;
# we rely on $infrequent_use_threshold being >= 1
if ($import_count{$func} == 1) {
# check to see if this class has multiple consumers
if (!$multiple_consumers{$class} && !$last_consumer_of_class{$class}) {
$last_consumer_of_class{$class} = $last_consumer_of{$func};
# $multiple_consumers{$class} = 0;
}
elsif ($last_consumer_of_class{$class} ne $last_consumer_of{$func}) {
# flag this to never match
$multiple_consumers{$class} = 1;
}
}
}