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#!/usr/bin/perl -w
#
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
use 5.004;
use strict;
use Getopt::Long;
$::opt_prune_depth = 0;
$::opt_subtree_size = 0;
$::opt_reverse = 0;
# GetOption will create $opt_object & $opt_exclude, so ignore the
# warning that gets spit out about those vbls.
GetOptions("object=s", "exclude=s", "comptrs=s", "ignore-balanced", "subtree-size=i", "prune-depth=i",
"collapse-to-method", "collapse-to-class", "old-style", "reverse");
$::opt_object ||
die qq{
usage: leak.pl < logfile
--object <obj> The address of the object to examine (required)
--exclude <file> Exclude routines listed in <file>
--comptrs <file> Subtract all the data in the balanced COMPtr log <file>
--ignore-balanced Ignore balanced subtrees
--subtree-size <n> Print subtrees with more than <n> nodes separately
--prune-depth <depth> Prune the tree to <depth>
--collapse-to-method Aggregate data by method
--collapse-to-class Aggregate data by class (subsumes --collapse-to-method)
--reverse Reverse call stacks, showing leaves first
--old-style Old-style formatting
};
$::opt_prune_depth = 0 if $::opt_prune_depth < 0;
$::opt_subtree_size = 0 if $::opt_subtree_size < 0;
warn "object $::opt_object\n";
warn "ignoring balanced subtrees\n" if $::opt_ignore_balanced;
warn "prune depth $::opt_prune_depth\n" if $::opt_prune_depth;
warn "collapsing to class\n" if $::opt_collapse_to_class;
warn "collapsing to method\n" if $::opt_collapse_to_method && !$::opt_collapse_to_class;
warn "reversing call stacks\n" if $::opt_reverse;
# The 'excludes' are functions that, if detected in a particular call
# stack, will cause the _entire_ call stack to be ignored. You might,
# for example, explicitly exclude two functions that have a matching
# AddRef/Release pair.
my %excludes;
if ($::opt_exclude) {
open(EXCLUDE, "<".$::opt_exclude)
|| die "unable to open $::opt_exclude";
while (<EXCLUDE>) {
chomp $_;
warn "excluding $_\n";
$excludes{$_} = 1;
}
}
# Each entry in the tree rooted by callGraphRoot contains the following:
# #name# This call's name+offset string
# #refcount# The net reference count of this call
# #label# The label used for this subtree; only defined for labeled nodes
# #children# List of children in alphabetical order
# zero or more children indexed by method name+offset strings.
my $callGraphRoot;
$callGraphRoot = { '#name#' => '.root', '#refcount#' => 'n/a' };
# The 'imbalance' is a gross count of how balanced a particular
# callsite is. It is used to prune away callsites that are detected to
# be balanced; that is, that have matching AddRef/Release() pairs.
my %imbalance;
$imbalance{'.root'} = 'n/a';
# The main read loop.
sub read_data($$$) {
my ($INFILE, $plus, $minus) = @_;
LINE: while (<$INFILE>) {
next LINE if (! /^</);
my @fields = split(/ /, $_);
my $class = shift(@fields);
my $obj = shift(@fields);
my $sno = shift(@fields);
next LINE unless ($obj eq $::opt_object);
my $op = shift(@fields);
next LINE unless ($op eq $plus || $op eq $minus);
my $cnt = shift(@fields);
# Collect the remaining lines to create a stack trace. We need to
# filter out the frame numbers so that frames that differ only in
# their frame number are considered equivalent. However, we need to
# keep a frame number on each line so that the fix*.py scripts can
# parse the output. So we set the frame number to 0 for every frame.
my @stack;
CALLSITE: while (<$INFILE>) {
chomp;
last CALLSITE if (/^$/);
$_ =~ s/#\d+: /#00: /; # replace frame number with 0
$stack[++$#stack] = $_;
}
# Reverse the remaining fields to produce the call stack, with the
# oldest frame at the front of the array.
if (! $::opt_reverse) {
@stack = reverse(@stack);
}
my $call;
# If any of the functions in the stack are supposed to be excluded,
# march on to the next line.
foreach $call (@stack) {
next LINE if exists($excludes{$call});
}
# Add the callstack as a path through the call graph, updating
# refcounts at each node.
my $caller = $callGraphRoot;
foreach $call (@stack) {
# Chop the method offset if we're 'collapsing to method' or
# 'collapsing to class'.
$call =~ s/\+0x.*$//g if ($::opt_collapse_to_method || $::opt_collapse_to_class);
# Chop the method name if we're 'collapsing to class'.
$call =~ s/::.*$//g if ($::opt_collapse_to_class);
my $site = $caller->{$call};
if (!$site) {
# This is the first time we've seen this callsite. Add a
# new entry to the call tree.
$site = { '#name#' => $call, '#refcount#' => 0 };
$caller->{$call} = $site;
}
if ($op eq $plus) {
++($site->{'#refcount#'});
++($imbalance{$call});
} elsif ($op eq $minus) {
--($site->{'#refcount#'});
--($imbalance{$call});
} else {
die "Bad operation $op";
}
$caller = $site;
}
}
}
read_data(*STDIN, "AddRef", "Release");
if ($::opt_comptrs) {
warn "Subtracting comptr log ". $::opt_comptrs . "\n";
open(COMPTRS, "<".$::opt_comptrs)
|| die "unable to open $::opt_comptrs";
# read backwards to subtract
read_data(*COMPTRS, "nsCOMPtrRelease", "nsCOMPtrAddRef");
}
sub num_alpha {
my ($aN, $aS, $bN, $bS);
($aN, $aS) = ($1, $2) if $a =~ /^(\d+) (.+)$/;
($bN, $bS) = ($1, $2) if $b =~ /^(\d+) (.+)$/;
return $a cmp $b unless defined $aN && defined $bN;
return $aN <=> $bN unless $aN == $bN;
return $aS cmp $bS;
}
# Given a subtree and its nesting level, return true if that subtree should be pruned.
# If it shouldn't be pruned, destructively attempt to prune its children.
# Also compute the #children# properties of unpruned nodes.
sub prune($$) {
my ($site, $nest) = @_;
# If they want us to prune the tree's depth, do so here.
return 1 if ($::opt_prune_depth && $nest >= $::opt_prune_depth);
# If the subtree is balanced, ignore it.
return 1 if ($::opt_ignore_balanced && !$site->{'#refcount#'});
my $name = $site->{'#name#'};
# If the symbol isn't imbalanced, then prune here (and warn)
if ($::opt_ignore_balanced && !$imbalance{$name}) {
warn "discarding " . $name . "\n";
# return 1;
}
my @children;
foreach my $child (sort num_alpha keys(%$site)) {
if (substr($child, 0, 1) ne '#') {
if (prune($site->{$child}, $nest + 1)) {
delete $site->{$child};
} else {
push @children, $site->{$child};
}
}
}
$site->{'#children#'} = \@children;
return 0;
}
# Compute the #label# properties of this subtree.
# Return the subtree's number of nodes, not counting nodes reachable
# through a labeled node.
sub createLabels($) {
my ($site) = @_;
my @children = @{$site->{'#children#'}};
my $nChildren = @children;
my $nDescendants = 0;
foreach my $child (@children) {
my $childDescendants = createLabels($child);
if ($nChildren > 1 && $childDescendants > $::opt_subtree_size) {
die "Internal error" if defined($child->{'#label#'});
$child->{'#label#'} = "__label__";
$childDescendants = 1;
}
$nDescendants += $childDescendants;
}
return $nDescendants + 1;
}
my $nextLabel = 0;
my @labeledSubtrees;
sub list($$$$$) {
my ($site, $nest, $nestStr, $childrenLeft, $root) = @_;
my $label = !$root && $site->{'#label#'};
# Assign a unique number to the label.
if ($label) {
die unless $label eq "__label__";
$label = "__" . ++$nextLabel . "__";
$site->{'#label#'} = $label;
push @labeledSubtrees, $site;
}
print $nestStr;
if ($::opt_old_style) {
print $label, " " if $label;
print $site->{'#name#'}, ": bal=", $site->{'#refcount#'}, "\n";
} else {
my $refcount = $site->{'#refcount#'};
my $l = 8 - length $refcount;
$l = 1 if $l < 1;
print $refcount, " " x $l;
print $label, " " if $label;
print $site->{'#name#'}, "\n";
}
$nestStr .= $childrenLeft && !$::opt_old_style ? "| " : " ";
if (!$label) {
my @children = @{$site->{'#children#'}};
$childrenLeft = @children;
foreach my $child (@children) {
$childrenLeft--;
list($child, $nest + 1, $nestStr, $childrenLeft);
}
}
}
if (!prune($callGraphRoot, 0)) {
createLabels $callGraphRoot if ($::opt_subtree_size);
list $callGraphRoot, 0, "", 0, 1;
while (@labeledSubtrees) {
my $labeledSubtree = shift @labeledSubtrees;
print "\n------------------------------\n",
$labeledSubtree->{'#label#'}, "\n";
list $labeledSubtree, 0, "", 0, 1;
}
print "\n------------------------------\n" if @labeledSubtrees;
}
print qq{
Imbalance
---------
};
foreach my $call (sort num_alpha keys(%imbalance)) {
print $call . " " . $imbalance{$call} . "\n";
}