1#!/usr/bin/perl
 
 2
 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}

 1#!/usr/bin/env perl
 2# SPDX-License-Identifier: GPL-2.0
 3
 4# Read two files produced by the stackusage script, and show the
 5# delta between them.
 6#
 7# Currently, only shows changes for functions listed in both files. We
 8# could add an option to show also functions which have vanished or
 9# appeared (which would often be due to gcc making other inlining
10# decisions).
11#
12# Another possible option would be a minimum absolute value for the
13# delta.
14#
15# A third possibility is for sorting by delta, but that can be
16# achieved by piping to sort -k5,5g.
17
18sub read_stack_usage_file {
19    my %su;
20    my $f = shift;
21    open(my $fh, '<', $f)
22	or die "cannot open $f: $!";
23    while (<$fh>) {
24	chomp;
25	my ($file, $func, $size, $type) = split;
26	# Old versions of gcc (at least 4.7) have an annoying quirk in
27	# that a (static) function whose name has been changed into
28	# for example ext4_find_unwritten_pgoff.isra.11 will show up
29	# in the .su file with a name of just "11". Since such a
30	# numeric suffix is likely to change across different
31	# commits/compilers/.configs or whatever else we're trying to
32	# tweak, we can't really track those functions, so we just
33	# silently skip them.
34	#
35	# Newer gcc (at least 5.0) report the full name, so again,
36	# since the suffix is likely to change, we strip it.
37	next if $func =~ m/^[0-9]+$/;
38	$func =~ s/\..*$//;
39	# Line numbers are likely to change; strip those.
40	$file =~ s/:[0-9]+$//;
41	$su{"${file}\t${func}"} = {size => $size, type => $type};
42    }
43    close($fh);
44    return \%su;
45}
46
47@ARGV == 2
48    or die "usage: $0 <old> <new>";
49
50my $old = read_stack_usage_file($ARGV[0]);
51my $new = read_stack_usage_file($ARGV[1]);
52my @common = sort grep {exists $new->{$_}} keys %$old;
53for (@common) {
54    my $x = $old->{$_}{size};
55    my $y = $new->{$_}{size};
56    my $delta = $y - $x;
57    if ($delta) {
58	printf "%s\t%d\t%d\t%+d\n", $_, $x, $y, $delta;
59    }
60}