diff options
| -rw-r--r-- | Documentation/kbuild/makefiles.txt | 12 | ||||
| -rw-r--r-- | Makefile | 4 | ||||
| -rw-r--r-- | scripts/Kbuild.include | 5 |
3 files changed, 19 insertions, 2 deletions
diff --git a/Documentation/kbuild/makefiles.txt b/Documentation/kbuild/makefiles.txt index 835b64acf0b..47435e56c5d 100644 --- a/Documentation/kbuild/makefiles.txt +++ b/Documentation/kbuild/makefiles.txt @@ -501,6 +501,18 @@ more details, with real examples. gcc >= 3.00. For gcc < 3.00, -malign-functions=4 is used. Note: cc-option-align uses KBUILD_CFLAGS for $(CC) options + cc-disable-warning + cc-disable-warning checks if gcc supports a given warning and returns + the commandline switch to disable it. This special function is needed, + because gcc 4.4 and later accept any unknown -Wno-* option and only + warn about it if there is another warning in the source file. + + Example: + KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable) + + In the above example, -Wno-unused-but-set-variable will be added to + KBUILD_CFLAGS only if gcc really accepts it. + cc-version cc-version returns a numerical version of the $(CC) compiler version. The format is <major><minor> where both are two digits. So for example @@ -569,7 +569,7 @@ endif # This warning generated too much noise in a regular build. # Use make W=1 to enable this warning (see scripts/Makefile.build) -KBUILD_CFLAGS += $(call cc-option, -Wno-unused-but-set-variable) +KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable) ifdef CONFIG_FRAME_POINTER KBUILD_CFLAGS += -fno-omit-frame-pointer -fno-optimize-sibling-calls @@ -616,7 +616,7 @@ CHECKFLAGS += $(NOSTDINC_FLAGS) KBUILD_CFLAGS += $(call cc-option,-Wdeclaration-after-statement,) # disable pointer signed / unsigned warnings in gcc 4.0 -KBUILD_CFLAGS += $(call cc-option,-Wno-pointer-sign,) +KBUILD_CFLAGS += $(call cc-disable-warning, pointer-sign) # disable invalid "can't wrap" optimizations for signed / pointers KBUILD_CFLAGS += $(call cc-option,-fno-strict-overflow) diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include index fae2d8d8cb0..c034dd7161a 100644 --- a/scripts/Kbuild.include +++ b/scripts/Kbuild.include @@ -118,6 +118,11 @@ cc-option-yn = $(call try-run,\ cc-option-align = $(subst -functions=0,,\ $(call cc-option,-falign-functions=0,-malign-functions=0)) +# cc-disable-warning +# Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable) +cc-disable-warning = $(call try-run,\ + $(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) -W$(strip $(1)) -c -xc /dev/null -o "$$TMP",-Wno-$(strip $(1))) + # cc-version # Usage gcc-ver := $(call cc-version) cc-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC)) |