Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755251Ab1DUVjG (ORCPT ); Thu, 21 Apr 2011 17:39:06 -0400 Received: from pfepb.post.tele.dk ([195.41.46.236]:47777 "EHLO pfepb.post.tele.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753658Ab1DUVjF (ORCPT ); Thu, 21 Apr 2011 17:39:05 -0400 X-Greylist: delayed 1811 seconds by postgrey-1.27 at vger.kernel.org; Thu, 21 Apr 2011 17:39:04 EDT Date: Thu, 21 Apr 2011 23:39:03 +0200 From: Sam Ravnborg To: Michal Marek , linux-kbuild , lkml , Borislav Petkov Subject: [RFC PATCH] kbuild: implement several W= levels Message-ID: <20110421213903.GB9660@merkur.ravnborg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit 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: 4978 Lines: 127 Building a kernel with "make W=1" produce far too much noise to be usefull. Divide the warning options in three groups: W=1 - usefull warning options W=2 - noisy but semi usefull warnign options W=3 - almost pure noise options I do not feel strongly about the distinction between group 2 and 3. But we should consider what we add in group 1. Sample run on my box (x86, 32bit allyesconfig build) CC kernel/bounds.s kernel/bounds.c:14: warning: no previous prototype for ‘foo’ GEN include/generated/bounds.h CC arch/x86/kernel/asm-offsets.s In file included from include/linux/sched.h:73, from arch/x86/kernel/asm-offsets.c:9: include/linux/signal.h: In function ‘sigorsets’: include/linux/signal.h:121: warning: nested extern declaration of ‘_NSIG_WORDS_is_unsupported_size’ include/linux/signal.h: In function ‘sigandsets’: include/linux/signal.h:124: warning: nested extern declaration of ‘_NSIG_WORDS_is_unsupported_size’ include/linux/signal.h: In function ‘signandsets’: include/linux/signal.h:127: warning: nested extern declaration of ‘_NSIG_WORDS_is_unsupported_size’ include/linux/signal.h: In function ‘signotset’: include/linux/signal.h:151: warning: nested extern declaration of ‘_NSIG_WORDS_is_unsupported_size’ arch/x86/kernel/asm-offsets.c: At top level: arch/x86/kernel/asm-offsets.c:30: warning: no previous prototype for ‘common’ the patch is only an RFC - and is not made on top of an upstream kernel with no additiona stuff applied. Sam diff --git a/Makefile b/Makefile index b967b96..f0e138b 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 diff --git a/scripts/Makefile.build b/scripts/Makefile.build index d5f925a..b65f820 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -56,31 +56,43 @@ endif # $(call cc-option... ) 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-2 += -Waggregate-return +warning-2 += -Wbad-function-cast +warning-2 += -Wcast-qual +warning-2 += -Wcast-align +warning-3 += -Wconversion +warning-2 += -Wdisabled-optimization +warning-2 += -Wlogical-op +warning-1 += -Wmissing-declarations +warning-1 += -Wmissing-format-attribute +warning-1 += $(call cc-option, -Wmissing-include-dirs,) +warning-1 += -Wmissing-prototypes +warning-1 += -Wnested-externs +warning-2 += -Wold-style-definition +warning-2 += $(call cc-option, -Woverlength-strings,) +warning-3 += -Wpacked +warning-3 += -Wpacked-bitfield-compat +warning-3 += -Wpadded +warning-3 += -Wpointer-arith +warning-2 += -Wredundant-decls +warning-2 += -Wshadow +warning-3 += -Wswitch-default +warning-3 += $(call cc-option, -Wvla,) +ifeq ($(KBUILD_ENABLE_EXTRA_GCC_CHECKS),1) + KBUILD_CFLAGS += $(warning-1) +else + ifeq ($(KBUILD_ENABLE_EXTRA_GCC_CHECKS),2) + KBUILD_CFLAGS += $(warning-1) $(warning-2) + else + ifeq ($(KBUILD_ENABLE_EXTRA_GCC_CHECKS),3) + KBUILD_CFLAGS += $(warning-1) $(warning-2) $(warning-3) + else + $(error W=$(KBUILD_ENABLE_EXTRA_GCC_CHECKS) is unknown) + endif + endif +endif endif include scripts/Makefile.lib -- 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/