linux/scripts/stackdelta
Kamil Rytarowski cb77f0d623 scripts: Switch to more portable Perl shebang
The default NetBSD package manager is pkgsrc and it installs Perl
along other third party programs under custom and configurable prefix.
The default prefix for binary prebuilt packages is /usr/pkg, and the
Perl executable lands in /usr/pkg/bin/perl.

This change switches "/usr/bin/perl" to "/usr/bin/env perl" as it's
the most portable solution that should work for almost everybody.
Perl's executable is detected automatically.

This change switches -w option passed to the executable with more
modern "use warnings;" approach. There is no functional change to the
default behavior.

While there, drop "require 5" from scripts/namespace.pl (Perl from 1994?).

Signed-off-by: Kamil Rytarowski <n54@gmx.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2017-05-14 11:20:44 +09:00

60 lines
1.8 KiB
Perl
Executable File

#!/usr/bin/env 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;
}
}