From 40df759e2b9ec945f1a5ddc61b3fdfbb6583257e Mon Sep 17 00:00:00 2001 From: Michal Marek Date: Wed, 20 Apr 2011 13:45:30 +0200 Subject: kbuild: Fix build with binutils <= 2.19 The D option of ar is only available in newer versions. Signed-off-by: Michal Marek --- scripts/Kbuild.include | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'scripts/Kbuild.include') diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include index ed2773edfe7..fae2d8d8cb0 100644 --- a/scripts/Kbuild.include +++ b/scripts/Kbuild.include @@ -141,6 +141,11 @@ cc-ldoption = $(call try-run,\ ld-option = $(call try-run,\ $(CC) /dev/null -c -o "$$TMPO" ; $(LD) $(1) "$$TMPO" -o "$$TMP",$(1),$(2)) +# ar-option +# Usage: KBUILD_ARFLAGS := $(call ar-option,D) +# Important: no spaces around options +ar-option = $(call try-run, $(AR) rc$(1) "$$TMP",$(1),$(2)) + ###### ### -- cgit v1.2.3-70-g09d2 From 8417da6f2128008c431c7d130af6cd3d9079922e Mon Sep 17 00:00:00 2001 From: Michal Marek Date: Mon, 2 May 2011 12:51:15 +0200 Subject: kbuild: Fix passing -Wno-* options to gcc 4.4+ Starting with 4.4, gcc will happily accept -Wno- in the cc-option test and complain later when compiling a file that has some other warning. This rather unexpected behavior is intentional as per http://gcc.gnu.org/PR28322, so work around it by testing for support of the opposite option (without the no-). Introduce a new Makefile function cc-disable-warning that does this and update two uses of cc-option in the toplevel Makefile. Reported-and-tested-by: Stephen Rothwell Signed-off-by: Michal Marek --- Documentation/kbuild/makefiles.txt | 12 ++++++++++++ Makefile | 4 ++-- scripts/Kbuild.include | 5 +++++ 3 files changed, 19 insertions(+), 2 deletions(-) (limited to 'scripts/Kbuild.include') 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 where both are two digits. So for example diff --git a/Makefile b/Makefile index bc9eae424af..5cf4eb03fb3 100644 --- a/Makefile +++ b/Makefile @@ -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 $(CC)) -- cgit v1.2.3-70-g09d2 From c4d5ee13984f57b2f881635c49045151679f5e8a Mon Sep 17 00:00:00 2001 From: Michal Marek Date: Mon, 16 May 2011 16:37:34 +0200 Subject: kbuild: make KBUILD_NOCMDDEP=1 handle empty built-in.o Based on a patch by Rabin Vincent. Fix building with KBUILD_NOCMDDEP=1, which currently does not work because it does not build built-in.o with no dependencies: LD fs/notify/built-in.o ld: cannot find fs/notify/dnotify/built-in.o: No such file or directory ld: cannot find fs/notify/inotify/built-in.o: No such file or directory ld: cannot find fs/notify/fanotify/built-in.o: No such file or directory Reported-and-tested-by: Rabin Vincent Signed-off-by: Michal Marek --- scripts/Kbuild.include | 2 ++ 1 file changed, 2 insertions(+) (limited to 'scripts/Kbuild.include') diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include index c034dd7161a..be39cd1c74c 100644 --- a/scripts/Kbuild.include +++ b/scripts/Kbuild.include @@ -197,6 +197,8 @@ ifneq ($(KBUILD_NOCMDDEP),1) # User may override this check using make KBUILD_NOCMDDEP=1 arg-check = $(strip $(filter-out $(cmd_$(1)), $(cmd_$@)) \ $(filter-out $(cmd_$@), $(cmd_$(1))) ) +else +arg-check = $(if $(strip $(cmd_$@)),,1) endif # >'< substitution is for echo to work, -- cgit v1.2.3-70-g09d2