2011-01-03 Xan Lopez <xlopez@igalia.com>

        Reviewed by Martin Robinson.

        [GTK] Disable superfluous GNU make built-in implicit rules
        https://bugs.webkit.org/show_bug.cgi?id=51826

        GNU make ships some superflous built-in rules that we never use
        and that end up adding up to a very significant portion of our
        total Makefile processing time. Disable them completely by
        defining the rule without any recipe, as suggested by the GNU make
        manual (10.5.6, Cancelling Implicit Rules).

        In my system the null-build goes from:

        make  43.51s user 12.77s system 99% cpu 56.628 total

        to:

        make  31.45s user 11.59s system 99% cpu 43.227 total

        * GNUmakefile.am: disable implicit built-in rules.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@74903 268f45cc-cd09-0410-ab3c-d52691b4dbfc

diff --git a/ChangeLog b/ChangeLog
index dc2af45c1531af471113e74ef771939394d1856f..b0d9f75c504fba2d232e250486bda0cf403d7749 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,26 @@
+2011-01-03  Xan Lopez  <xlopez@igalia.com>
+
+        Reviewed by Martin Robinson.
+
+        [GTK] Disable superfluous GNU make built-in implicit rules
+        https://bugs.webkit.org/show_bug.cgi?id=51826
+
+        GNU make ships some superflous built-in rules that we never use
+        and that end up adding up to a very significant portion of our
+        total Makefile processing time. Disable them completely by
+        defining the rule without any recipe, as suggested by the GNU make
+        manual (10.5.6, Cancelling Implicit Rules).
+
+        In my system the null-build goes from:
+
+        make  43.51s user 12.77s system 99% cpu 56.628 total
+
+        to:
+
+        make  31.45s user 11.59s system 99% cpu 43.227 total
+
+        * GNUmakefile.am: disable implicit built-in rules.
+
 2011-01-03  Mihai Parparita  <mihaip@chromium.org>
 
         Unreviewed. Update .gitignore with new JavaScriptCore location.

diff --git a/GNUmakefile.am b/GNUmakefile.am
index 17db6237ca8ed23289e23804f5b5f532a93895d9..238a1aa0858e2becb61e8bd4e23aa475c13512c6 100644 (file)
--- a/GNUmakefile.am
+++ b/GNUmakefile.am
@@ -86,6 +86,21 @@ CLEANFILES :=
 DISTCLEANFILES :=
 MAINTAINERCLEANFILES :=
 
+# We do not care at all about this implicit built-in make rules,
+# disable them to save some build time
+%: %.c
+%: %.cpp
+%: %.o
+(%): %
+%.out: %
+%.c: %.w %.ch
+%.tex: %.w %.ch
+%:: %,v
+%:: RCS/%,v
+%:: RCS/%
+%:: s.%
+%:: SCCS/s.%
+
 global_cppflags += \
        -Wall -W -Wcast-align -Wchar-subscripts -Wreturn-type \
        -Wformat -Wformat-security -Wno-format-y2k -Wundef \