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authorBorislav Petkov <bp@alien8.de>2011-03-01 09:35:29 +0100
committerPaul Gortmaker <paul.gortmaker@windriver.com>2012-08-17 15:35:53 -0400
commit0d34797e902e198b671075368d2280add20b518a (patch)
tree87bdf0a3ccb853ed2fafdc08ccee6bb744eb5156
parent2ccd3d16c41e5b6226f24bb168298f18b90c5415 (diff)
kbuild: Add extra gcc checks
commit 4a5838ad9d2d4f7354a310982483f4c76aa0abeb upstream. Add a 'W=1' Makefile switch which adds additional checking per build object. The idea behind this option is targeted at developers who, in the process of writing their code, want to do the occasional make W=1 [target.o] and let gcc do more extensive code checking for them. Then, they could eyeball the output for valid gcc warnings about various bugs/discrepancies which are not reported during the normal build process. For more background information and a use case, read through this thread: http://marc.info/?l=kernel-janitors&m=129802065918147&w=2 Cc: Michal Marek <mmarek@suse.cz> Cc: linux-kbuild@vger.kernel.org Acked-by: Sam Ravnborg <sam@ravnborg.org> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Michal Marek <mmarek@suse.cz> [PG: used for 2.6.34 to better control new compilers on older code] Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
-rw-r--r--Documentation/kbuild/kbuild.txt5
-rw-r--r--Makefile5
-rw-r--r--scripts/Makefile.build35
3 files changed, 44 insertions, 1 deletions
diff --git a/Documentation/kbuild/kbuild.txt b/Documentation/kbuild/kbuild.txt
index 6f8c1cabbc5d..6c35f63fde73 100644
--- a/Documentation/kbuild/kbuild.txt
+++ b/Documentation/kbuild/kbuild.txt
@@ -162,3 +162,8 @@ For tags/TAGS/cscope targets, you can specify more than one arch
to be included in the databases, separated by blank space. E.g.:
$ make ALLSOURCE_ARCHS="x86 mips arm" tags
+
+KBUILD_ENABLE_EXTRA_GCC_CHECKS
+--------------------------------------------------
+If enabled over the make command line with "W=1", it turns on additional
+gcc -W... options for more extensive build-time checking.
diff --git a/Makefile b/Makefile
index eb9038f47f12..e922e6090ca9 100644
--- a/Makefile
+++ b/Makefile
@@ -102,6 +102,10 @@ ifeq ("$(origin O)", "command line")
KBUILD_OUTPUT := $(O)
endif
+ifeq ("$(origin W)", "command line")
+ export KBUILD_ENABLE_EXTRA_GCC_CHECKS := 1
+endif
+
# That's our default target when none is given on the command line
PHONY := _all
_all:
@@ -1291,6 +1295,7 @@ 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 ''
@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 0b94d2fa3a88..bd9d51864ebb 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -49,6 +49,40 @@ ifeq ($(KBUILD_NOPEDANTIC),)
$(error CFLAGS was changed in "$(kbuild-file)". Fix it to use EXTRA_CFLAGS)
endif
endif
+
+#
+# make W=1 settings
+#
+# $(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 += $(KBUILD_EXTRA_WARNINGS)
+endif
+
include scripts/Makefile.lib
ifdef host-progs
@@ -384,7 +418,6 @@ ifneq ($(cmd_files),)
include $(cmd_files)
endif
-
# Declare the contents of the .PHONY variable as phony. We keep that
# information in a variable se we can use it in if_changed and friends.