Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752662Ab1DVHiH (ORCPT ); Fri, 22 Apr 2011 03:38:07 -0400 Received: from pfepa.post.tele.dk ([195.41.46.235]:39641 "EHLO pfepa.post.tele.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752392Ab1DVHiD (ORCPT ); Fri, 22 Apr 2011 03:38:03 -0400 Date: Fri, 22 Apr 2011 09:38:01 +0200 From: Sam Ravnborg To: Michal Marek , linux-kbuild , lkml Cc: Dave Jones , Borislav Petkov Subject: [RFC PATCH v2] kbuild: implement several W= levels Message-ID: <20110422073800.GA20603@merkur.ravnborg.org> References: <20110421213903.GB9660@merkur.ravnborg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110421213903.GB9660@merkur.ravnborg.org> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5572 Lines: 159 >From 7f1edfc13eadc1cf8c80d72ff850a121bf472e00 Mon Sep 17 00:00:00 2001 From: Sam Ravnborg Date: Fri, 22 Apr 2011 08:22:25 +0200 Subject: [PATCH] kbuild: implement several W= levels Building a kernel with "make W=1" produce far too much noise to be usefull. Divide the warning options in three groups: W=1 - warnings that may be relevant and does not occur too often W=2 - warnings that occur quite often but may still be relevant W=3 - the more obscure warnings, can most likely be ignored When building init/ on my box the levels produces: W=1 - 46 warnings W=2 - 863 warnings W=3 - 6496 warnings Many warnings occur from .h files so fixing one file may have a nice effect on the total number of warnings. With these changes I am actually tempted to try W=1 now and then. Previously there were just too much noise. Signed-off-by: Sam Ravnborg Cc: Borislav Petkov Cc: Dave Jones --- This is based on top of -linus to make it easy to test. But I included fixes for older gcc as posted in a separate patch. Changes since v1: - updated help text - updated grouping, less warnings in W=1 - reimplment selection of warnings for the individual levels - added a comment describing the individual levels Sam Makefile | 4 +- scripts/Makefile.build | 69 +++++++++++++++++++++++++++++------------------ 2 files changed, 44 insertions(+), 29 deletions(-) diff --git a/Makefile b/Makefile index b967b96..37a6062 100644 --- a/Makefile +++ b/Makefile @@ -103,7 +103,7 @@ ifeq ("$(origin O)", "command line") endif ifeq ("$(origin W)", "command line") - export KBUILD_ENABLE_EXTRA_GCC_CHECKS := 1 + export KBUILD_ENABLE_EXTRA_GCC_CHECKS := $(W) endif # That's our default target when none is given on the command line @@ -1267,7 +1267,7 @@ help: @echo ' make O=dir [targets] Locate all output files in "dir", including .config' @echo ' make C=1 [targets] Check all c source with $$CHECK (sparse by default)' @echo ' make C=2 [targets] Force check of all c source with $$CHECK' - @echo ' make W=1 [targets] Enable extra gcc checks' + @echo ' make W=n [targets] Enable extra gcc checks, n=1,2,3' @echo '' @echo 'Execute "make" or "make all" to build all targets marked with [*] ' @echo 'For further info see the ./README file' diff --git a/scripts/Makefile.build b/scripts/Makefile.build index d5f925a..6874c3b 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -51,36 +51,51 @@ ifeq ($(KBUILD_NOPEDANTIC),) endif # -# make W=1 settings +# make W=... settings # -# $(call cc-option... ) handles gcc -W.. options which +# W=1 - warnings that may be relevant and does not occur too often +# W=2 - warnings that occur quite often but may still be relevant +# W=3 - the more obscure warnings, can most likely be ignored +# +# $(call cc-option, -W...) handles gcc -W.. options which # are not supported by all versions of the compiler ifdef KBUILD_ENABLE_EXTRA_GCC_CHECKS -KBUILD_EXTRA_WARNINGS := -Wextra -KBUILD_EXTRA_WARNINGS += -Wunused -Wno-unused-parameter -KBUILD_EXTRA_WARNINGS += -Waggregate-return -KBUILD_EXTRA_WARNINGS += -Wbad-function-cast -KBUILD_EXTRA_WARNINGS += -Wcast-qual -KBUILD_EXTRA_WARNINGS += -Wcast-align -KBUILD_EXTRA_WARNINGS += -Wconversion -KBUILD_EXTRA_WARNINGS += -Wdisabled-optimization -KBUILD_EXTRA_WARNINGS += -Wlogical-op -KBUILD_EXTRA_WARNINGS += -Wmissing-declarations -KBUILD_EXTRA_WARNINGS += -Wmissing-format-attribute -KBUILD_EXTRA_WARNINGS += $(call cc-option, -Wmissing-include-dirs,) -KBUILD_EXTRA_WARNINGS += -Wmissing-prototypes -KBUILD_EXTRA_WARNINGS += -Wnested-externs -KBUILD_EXTRA_WARNINGS += -Wold-style-definition -KBUILD_EXTRA_WARNINGS += $(call cc-option, -Woverlength-strings,) -KBUILD_EXTRA_WARNINGS += -Wpacked -KBUILD_EXTRA_WARNINGS += -Wpacked-bitfield-compat -KBUILD_EXTRA_WARNINGS += -Wpadded -KBUILD_EXTRA_WARNINGS += -Wpointer-arith -KBUILD_EXTRA_WARNINGS += -Wredundant-decls -KBUILD_EXTRA_WARNINGS += -Wshadow -KBUILD_EXTRA_WARNINGS += -Wswitch-default -KBUILD_EXTRA_WARNINGS += $(call cc-option, -Wvla,) -KBUILD_CFLAGS += $(KBUILD_EXTRA_WARNINGS) +warning-1 := -Wextra +warning-1 += -Wunused -Wno-unused-parameter +warning-1 += -Wmissing-declarations +warning-1 += -Wmissing-format-attribute +warning-1 += -Wmissing-prototypes +warning-1 += -Wnested-externs +warning-1 += $(call cc-option, -Wmissing-include-dirs) + +warning-2 := $(warning-1) +warning-2 += -Waggregate-return +warning-2 += -Wbad-function-cast +warning-2 += -Wcast-qual +warning-2 += -Wcast-align +warning-2 += -Wdisabled-optimization +warning-2 += -Wold-style-definition +warning-2 += -Wshadow +warning-2 += $(call cc-option, -Wlogical-op) +warning-2 += $(call cc-option, -Woverlength-strings) + +warning-3 := $(warning-2) +warning-3 += -Wconversion +warning-3 += -Wpacked +warning-3 += -Wpadded +warning-3 += -Wpointer-arith +warning-3 += -Wredundant-decls +warning-3 += -Wswitch-default +warning-3 += $(call cc-option, -Wpacked-bitfield-compat) +warning-3 += $(call cc-option, -Wvla) + +warning := $(warning-$(KBUILD_ENABLE_EXTRA_GCC_CHECKS)) + +ifeq ("$(warning)","") + $(error W=$(KBUILD_ENABLE_EXTRA_GCC_CHECKS) is unknown) +endif + +KBUILD_CFLAGS += $(warning) endif include scripts/Makefile.lib -- 1.6.0.6 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/