Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754911Ab1DVKqx (ORCPT ); Fri, 22 Apr 2011 06:46:53 -0400 Received: from mail.skyhub.de ([78.46.96.112]:58139 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754526Ab1DVKqu (ORCPT ); Fri, 22 Apr 2011 06:46:50 -0400 Date: Fri, 22 Apr 2011 12:46:46 +0200 From: Borislav Petkov To: Sam Ravnborg Cc: Michal Marek , Dave Jones , linux-kbuild , lkml Subject: [PATCH v3] kbuild: implement several W= levels Message-ID: <20110422104646.GB8324@liondog.tnic> Mail-Followup-To: Borislav Petkov , Sam Ravnborg , Michal Marek , Dave Jones , linux-kbuild , lkml MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20110422102028.GA8324@liondog.tnic> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6110 Lines: 175 On Fri, Apr 22, 2011 at 12:20:28PM +0200, Borislav Petkov wrote: > But seriously, let me add my comments to your patch while they're fresh > in my head and let's see what we come up with in our combined and > perfectly orchestrated effort :). Ok, this is starting to look like another kernelnewbies.org task: make W=x 2>>w.log and stare at compiler output in the other xterm: tail -f w.log and the bugs are just waiting there to be fixed! :) Below is v3, please take a look. -- 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. Borislav: - make the W= levels exclusive - drop -Wmissing-prototypes since it is being added to the toplevel Makefile - move very noisy and making little sense for the kernel warnings to W=3 - drop -Woverlength-strings due to useless warning message - copy explanatory text for the different warning levels to 'make help' Signed-off-by: Sam Ravnborg Signed-off-by: Borislav Petkov Cc: Dave Jones --- Makefile | 8 ++++- scripts/Makefile.build | 64 +++++++++++++++++++++++++++-------------------- 2 files changed, 43 insertions(+), 29 deletions(-) diff --git a/Makefile b/Makefile index b967b96..17ce5d5 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 +1267,11 @@ 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 where' + @echo ' 1: warnings which may be relevant and do not occur too often' + @echo ' 2: warnings which occur quite often but may still be relevant' + @echo ' 3: more obscure warnings, can most likely be ignored' + @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..3c6e7ed 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -51,36 +51,46 @@ 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 -Wunused -Wno-unused-parameter +warning-1 += -Wmissing-declarations +warning-1 += -Wmissing-format-attribute +warning-1 += -Wold-style-definition +warning-1 += $(call cc-option, -Wmissing-include-dirs) + +warning-2 := -Waggregate-return +warning-2 += -Wcast-align +warning-2 += -Wdisabled-optimization +warning-2 += -Wnested-externs +warning-2 += -Wshadow +warning-2 += $(call cc-option, -Wlogical-op) + +warning-3 := -Wbad-function-cast +warning-3 += -Wcast-qual +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 -- 1.7.5.rc1.16.g9db1 -- Regards/Gruss, Boris. -- 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/