kbuild: Allow to combine multiple W= levels
Add support for make W=12, make W=123 and so on, to enable warnings from
multiple W= levels. Normally, make W=<level> does not include warnings
from the previous level.
Signed-off-by: Michal Marek <mmarek@suse.cz>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-By: Valdis Kletnieks <valdis.kletnieks@vt.edu>
diff --git a/Makefile b/Makefile
index 4527dc2..d342502 100644
--- a/Makefile
+++ b/Makefile
@@ -1290,7 +1290,7 @@
@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 ' Multiple levels can be combined with W=12 or W=123'
@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 9fb19c0..f133641 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -60,6 +60,8 @@
# $(call cc-option, -W...) handles gcc -W.. options which
# are not supported by all versions of the compiler
ifdef KBUILD_ENABLE_EXTRA_GCC_CHECKS
+warning- := $(empty)
+
warning-1 := -Wextra -Wunused -Wno-unused-parameter
warning-1 += -Wmissing-declarations
warning-1 += -Wmissing-format-attribute
@@ -86,9 +88,11 @@
warning-3 += $(call cc-option, -Wpacked-bitfield-compat)
warning-3 += $(call cc-option, -Wvla)
-warning := $(warning-$(KBUILD_ENABLE_EXTRA_GCC_CHECKS))
+warning := $(warning-$(findstring 1, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)))
+warning += $(warning-$(findstring 2, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)))
+warning += $(warning-$(findstring 3, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)))
-ifeq ("$(warning)","")
+ifeq ("$(strip $(warning))","")
$(error W=$(KBUILD_ENABLE_EXTRA_GCC_CHECKS) is unknown)
endif