michael@0: # This Source Code Form is subject to the terms of the Mozilla Public
michael@0: # License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0: # file, You can obtain one at http://mozilla.org/MPL/2.0/.
michael@0: package TraceMalloc;
michael@0: 
michael@0: use strict;
michael@0: 
michael@0: # Read in the type inference file and construct a network that we can
michael@0: # use to match stack prefixes to types.
michael@0: sub init_type_inference($) {
michael@0:     my ($file) = @_;
michael@0: 
michael@0:     $::Fingerprints = { };
michael@0: 
michael@0:     open(TYPES, "<$file") || die "unable to open $::opt_types, $!";
michael@0: 
michael@0:   TYPE: while (<TYPES>) {
michael@0:       next TYPE unless /<(.*)>/;
michael@0:       my $type = $1;
michael@0: 
michael@0:       my $link = \%::Fingerprints;
michael@0: 
michael@0:     FRAME: while (<TYPES>) {
michael@0:         chomp;
michael@0:         last FRAME if /^$/;
michael@0: 
michael@0:         my $next = $link->{$_};
michael@0:         if (! $next) {
michael@0:             $next = $link->{$_} = {};
michael@0:         }
michael@0:         $link = $next;
michael@0:     }
michael@0: 
michael@0:       $link->{'#type#'} = $type;
michael@0: 
michael@0:       last TYPE if eof;
michael@0:   }
michael@0: }
michael@0: 
michael@0: # Infer the type, trying to find the most specific type possible.
michael@0: sub infer_type($) {
michael@0:     my ($stack) = @_;
michael@0: 
michael@0:     my $link = \%::Fingerprints;
michael@0:     my $last;
michael@0:     my $type = 'void*';
michael@0:   FRAME: foreach my $frame (@$stack) {
michael@0:       last FRAME unless $link;
michael@0: 
michael@0:       $frame =~ s/\[.*\]$//; # ignore exact addresses, as they'll drift
michael@0: 
michael@0:       $last = $link;
michael@0: 
michael@0:       #
michael@0:       # Remember this type, but keep going.  We use the longest match
michael@0:       # we find, but substacks of longer matches will also match.
michael@0:       #
michael@0:       if ($last->{'#type#'}) {
michael@0:           $type = $last->{'#type#'};
michael@0:       }
michael@0: 
michael@0:       $link = $link->{$frame};
michael@0: 
michael@0:       if (! $link) {
michael@0:         CHILD: foreach my $child (keys %$last) {
michael@0:             next CHILD unless $child =~ /^~/;
michael@0: 
michael@0:             $child =~ s/^~//;
michael@0: 
michael@0:             if ($frame =~ $child) {
michael@0:                 $link = $last->{'~' . $child};
michael@0:                 last CHILD;
michael@0:             }
michael@0:           }
michael@0:       }
michael@0:   }
michael@0: 
michael@0:     return $type;
michael@0: }
michael@0: 
michael@0: 
michael@0: #----------------------------------------------------------------------
michael@0: #
michael@0: # Read in the output a trace malloc's dump. 
michael@0: #
michael@0: sub read {
michael@0:     my ($callback, $noslop) = @_;
michael@0: 
michael@0:   OBJECT: while (<>) {
michael@0:       # e.g., 0x0832FBD0 <void*> (80)
michael@0:       next OBJECT unless /^0x(\S+) <(.*)> \((\d+)\)/;
michael@0:       my ($addr, $type, $size) = (hex $1, $2, $3);
michael@0: 
michael@0:       my $object = { 'type' => $type, 'size' => $size };
michael@0: 
michael@0:       # Record the object's slots
michael@0:       my @slots;
michael@0: 
michael@0:     SLOT: while (<>) {
michael@0:         # e.g.,      0x00000000
michael@0:         last SLOT unless /^\t0x(\S+)/;
michael@0:         my $value = hex $1;
michael@0: 
michael@0:         # Ignore low bits, unless they've specified --noslop
michael@0:         $value &= ~0x7 unless $noslop;
michael@0: 
michael@0:         $slots[$#slots + 1] = $value;
michael@0:     }
michael@0: 
michael@0:       $object->{'slots'} = \@slots;
michael@0: 
michael@0:       # Record the stack by which the object was allocated
michael@0:       my @stack;
michael@0: 
michael@0:       while (/^(.*)\[(.*) \+0x(\S+)\]$/) {
michael@0:           # e.g., _dl_debug_message[/lib/ld-linux.so.2 +0x0000B858]
michael@0:           my ($func, $lib, $off) = ($1, $2, hex $3);
michael@0: 
michael@0:           chomp;
michael@0:           $stack[$#stack + 1] = $_;
michael@0: 
michael@0:           $_ = <>;
michael@0:       }
michael@0: 
michael@0:       $object->{'stack'} = \@stack;
michael@0: 
michael@0:       $object->{'type'} = infer_type(\@stack)
michael@0:           if $object->{'type'} eq 'void*';
michael@0: 
michael@0:       &$callback($object) if $callback;
michael@0: 
michael@0:       # Gotta check EOF explicitly...
michael@0:       last OBJECT if eof;
michael@0:   }
michael@0: }
michael@0: 
michael@0: 1;
michael@0: __END__
michael@0: 
michael@0: =head1 NAME
michael@0: 
michael@0: TraceMalloc - Perl routines to deal with output from ``trace malloc''
michael@0: and the Boehm GC
michael@0: 
michael@0: =head1 SYNOPSIS
michael@0: 
michael@0:     use TraceMalloc;
michael@0: 
michael@0:     TraceMalloc::init_type_inference("types.dat");
michael@0:     TraceMalloc::read(0);
michael@0: 
michael@0: =head1 DESCRIPTION
michael@0: 
michael@0: =head1 EXAMPLES
michael@0: 
michael@0: =cut