kbuild: implement several W= levels
Building a kernel with "make W=1" produces far too much noise to be
useful.
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 the whole kernel, those levels produce:
W=1 - 4859 warnings
W=2 - 1394 warnings
W=3 - 86666 warnings
respectively. Warnings have been counted with Geert's script at
http://www.kernel.org/pub/linux/kernel/people/geert/linux-log/linux-log-summary.pl
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 was just too much noise.
Borislav:
- make the W= levels exclusive
- 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'
- recount warnings per level
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Borislav Petkov <bp@alien8.de>
Cc: Dave Jones <davej@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>
diff --git a/Makefile b/Makefile
index d7c4231..d43429f 100644
--- a/Makefile
+++ b/Makefile
@@ -103,7 +103,7 @@
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
@@ -1274,7 +1274,11 @@
@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'