| #!/usr/bin/perl |
| |
| # 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; |
| } |
| } |