blob: 20a79f19a111d7ad319c91c3f53d105524530619 [file] [log] [blame]
Finn Behrens2d1f7c92020-11-23 15:15:33 +01001#!/usr/bin/env perl
Rasmus Villemoes5bbb9f72015-08-20 11:53:30 +02002
3# Read two files produced by the stackusage script, and show the
4# delta between them.
5#
6# Currently, only shows changes for functions listed in both files. We
7# could add an option to show also functions which have vanished or
8# appeared (which would often be due to gcc making other inlining
9# decisions).
10#
11# Another possible option would be a minimum absolute value for the
12# delta.
13#
14# A third possibility is for sorting by delta, but that can be
15# achieved by piping to sort -k5,5g.
16
17sub read_stack_usage_file {
18 my %su;
19 my $f = shift;
20 open(my $fh, '<', $f)
21 or die "cannot open $f: $!";
22 while (<$fh>) {
23 chomp;
24 my ($file, $func, $size, $type) = split;
25 # Old versions of gcc (at least 4.7) have an annoying quirk in
26 # that a (static) function whose name has been changed into
27 # for example ext4_find_unwritten_pgoff.isra.11 will show up
28 # in the .su file with a name of just "11". Since such a
29 # numeric suffix is likely to change across different
30 # commits/compilers/.configs or whatever else we're trying to
31 # tweak, we can't really track those functions, so we just
32 # silently skip them.
33 #
34 # Newer gcc (at least 5.0) report the full name, so again,
35 # since the suffix is likely to change, we strip it.
36 next if $func =~ m/^[0-9]+$/;
37 $func =~ s/\..*$//;
38 # Line numbers are likely to change; strip those.
39 $file =~ s/:[0-9]+$//;
40 $su{"${file}\t${func}"} = {size => $size, type => $type};
41 }
42 close($fh);
43 return \%su;
44}
45
46@ARGV == 2
47 or die "usage: $0 <old> <new>";
48
49my $old = read_stack_usage_file($ARGV[0]);
50my $new = read_stack_usage_file($ARGV[1]);
51my @common = sort grep {exists $new->{$_}} keys %$old;
52for (@common) {
53 my $x = $old->{$_}{size};
54 my $y = $new->{$_}{size};
55 my $delta = $y - $x;
56 if ($delta) {
57 printf "%s\t%d\t%d\t%+d\n", $_, $x, $y, $delta;
58 }
59}