Hello, On penktadienis 11 Gruodis 2009 20:58:44 Joey Hess wrote: > Modestas Vainius wrote: > > If debhelper program has nothing to do, it will exit fast. Slow down > > should be minimal. > > There is some potential for speeding up dh. Josh Tripplet and I once > discussed: > > * Having dh optimize out calls to debhelper commands that will be > no-ops. For a subset of commands, this can be determined just > by looking for their config files. Some kind of metadata would be > necessary for dh to tell which commands are in that subset. > > * Make dh run debhelper commands directly in one perl process, rather > than through exec. (However, I think this is unlikely to be worth the > insanity.) > > * Writing a faster parser for simple command-line options. Benchmarks > show that parsing options is 50% of the overhead of running no-op > debhelper commands. This is because if there are options, it loads > Getopt::Long, which is slow. This overhead is particularly bad > when dh needs to pass -i / -a to all commands, which otherwise > would need no options. > > * Removing calls to dpkg-architecture from dh_auto_configure and > dh_auto_build when they will not actually be configuring or building. > > * Speed up dh_gencontrol, er, I mean dpkg-gencontrol, which by itself > is responsible for more than 1/3 of the total runtime of dh binary > in a package where the other debhelper commands are all no-ops.
* Detect noop (empty) override targets when parsing debian/rules and avoid make calls for them. Patch attached. -- Modestas Vainius <modes...@vainius.eu>
From cbd509e6b6fe690c0c59df7f117b402be8c89bff Mon Sep 17 00:00:00 2001
From: Modestas Vainius <modes...@vainius.eu>
Date: Fri, 11 Dec 2009 23:10:01 +0200
Subject: [PATCH] Do not call make for noop overrides.
1) Detect if target is noop when parsing debian/rules.
2) If override target is noop, do not call make for it.
---
dh | 79 +++++++++++++++++++++++++++++++++++++++++++++++--------------------
1 files changed, 55 insertions(+), 24 deletions(-)
diff --git a/dh b/dh
index 11fb27b..f1b1b68 100755
--- a/dh
+++ b/dh
@@ -526,30 +526,44 @@ sub run {
# Check for override targets in debian/rules and
# run them instead of running the command directly.
my $override_command;
- if (rules_explicit_target("override_".$command)) {
+ my $has_explicit_target = rules_explicit_target("override_".$command);
+ if (defined $has_explicit_target) {
$override_command=$command;
- # This passes the options through to commands called
- # inside the target.
- $ENV{DH_INTERNAL_OPTIONS}=join("\x1e", @options);
- $command="debian/rules";
- @options="override_".$override_command;
+ # Check if target isn't noop
+ if ($has_explicit_target) {
+ # This passes the options through to commands called
+ # inside the target.
+ $ENV{DH_INTERNAL_OPTIONS}=join("\x1e", @options);
+ $command="debian/rules";
+ @options="override_".$override_command;
+ }
+ else {
+ $command = undef;
+ }
}
else {
# Pass additional command options if any
unshift @options, @{$command_opts{$command}} if exists $command_opts{$command};
}
- # 3 space indent lines the command being run up under the
- # sequence name after "dh ".
- print " ".escape_shell($command, @options)."\n";
+ if (defined $command) {
+ # 3 space indent lines the command being run up under the
+ # sequence name after "dh ".
+ print " ".escape_shell($command, @options)."\n";
+ }
+ else {
+ print " ", "# Skipping ", $override_command, " - empty override", "\n";
+ }
if (! $dh{NO_ACT}) {
- my $ret=system($command, @options);
- if ($ret >> 8 != 0) {
- exit $ret >> 8;
- }
- elsif ($ret) {
- exit 1;
+ if (defined $command) {
+ my $ret=system($command, @options);
+ if ($ret >> 8 != 0) {
+ exit $ret >> 8;
+ }
+ elsif ($ret) {
+ exit 1;
+ }
}
if (defined $override_command) {
@@ -575,11 +589,14 @@ my $rules_parsed;
sub rules_explicit_target {
# Checks if a specified target exists as an explicit target
# in debian/rules.
+ # undef is returned if target does not exist, 0 if target is noop
+ # and 1 if target has dependencies or executes commands.
my $target=shift;
-
- if (! $rules_parsed) {
+
+ if (! $rules_parsed) {
my $processing_targets = 0;
my $not_a_target = 0;
+ my $current_target;
open(MAKE, "LC_ALL=C make -Rrnpsf debian/rules debhelper-fail-me 2>/dev/null |");
while (<MAKE>) {
if ($processing_targets) {
@@ -587,12 +604,26 @@ sub rules_explicit_target {
$not_a_target = 1;
}
else {
- if (!$not_a_target && /^([^#:]+)::?/) {
- # Target is defined.
- # NOTE: if it is a depenency
- # of .PHONY it will be
- # defined too but that's ok.
- $targets{$1} = 1;
+ if (!$not_a_target && /^([^#:]+)::?\s*(.*)$/) {
+ # Target is defined. NOTE: if it is a depenency of
+ # .PHONY it will be defined too but that's ok.
+ # $2 contains target dependencies if any.
+ $current_target = $1;
+ $targets{$current_target} = ($2) ? 1 : 0;
+ }
+ else {
+ if (defined $current_target) {
+ if (/^#/) {
+ # Check if target has commands to execute
+ if (/^#\s*commands to execute/) {
+ $targets{$current_target} = 1;
+ }
+ }
+ else {
+ # Target parsed.
+ $current_target = undef;
+ }
+ }
}
# "Not a target:" is always followed by
# a target name, so resetting this one
@@ -607,7 +638,7 @@ sub rules_explicit_target {
$rules_parsed = 1;
}
- return exists $targets{$target};
+ return (exists $targets{$target}) ? $targets{$target} : undef;
}
}
--
1.6.5.4
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