| #!/usr/bin/env perl | |
| # SPDX-License-Identifier: GPL-2.0 | |
| # Read two files produced by the stackusage script, and show the | |
| # delta between them. | |
| # | |
| # Currently, only shows changes for functions listed in both files. We | |
| # could add an option to show also functions which have vanished or | |
| # appeared (which would often be due to gcc making other inlining | |
| # decisions). | |
| # | |
| # Another possible option would be a minimum absolute value for the | |
| # delta. | |
| # | |
| # A third possibility is for sorting by delta, but that can be | |
| # achieved by piping to sort -k5,5g. | |
| sub read_stack_usage_file { | |
| my %su; | |
| my $f = shift; | |
| open(my $fh, '<', $f) | |
| or die "cannot open $f: $!"; | |
| while (<$fh>) { | |
| chomp; | |
| my ($file, $func, $size, $type) = split; | |
| # Old versions of gcc (at least 4.7) have an annoying quirk in | |
| # that a (static) function whose name has been changed into | |
| # for example ext4_find_unwritten_pgoff.isra.11 will show up | |
| # in the .su file with a name of just "11". Since such a | |
| # numeric suffix is likely to change across different | |
| # commits/compilers/.configs or whatever else we're trying to | |
| # tweak, we can't really track those functions, so we just | |
| # silently skip them. | |
| # | |
| # Newer gcc (at least 5.0) report the full name, so again, | |
| # since the suffix is likely to change, we strip it. | |
| next if $func =~ m/^[0-9]+$/; | |
| $func =~ s/\..*$//; | |
| # Line numbers are likely to change; strip those. | |
| $file =~ s/:[0-9]+$//; | |
| $su{"${file}\t${func}"} = {size => $size, type => $type}; | |
| } | |
| close($fh); | |
| return \%su; | |
| } | |
| @ARGV == 2 | |
| or die "usage: $0 <old> <new>"; | |
| my $old = read_stack_usage_file($ARGV[0]); | |
| my $new = read_stack_usage_file($ARGV[1]); | |
| my @common = sort grep {exists $new->{$_}} keys %$old; | |
| for (@common) { | |
| my $x = $old->{$_}{size}; | |
| my $y = $new->{$_}{size}; | |
| my $delta = $y - $x; | |
| if ($delta) { | |
| printf "%s\t%d\t%d\t%+d\n", $_, $x, $y, $delta; | |
| } | |
| } |