[PATCH] Makefile: Use computed header dependencies if the compiler supports it
From: Fredrik Kuivinen <hidden>
Date: 2016-06-15 22:51:31
Subsystem:
kernel build + files below scripts/ (unless maintained elsewhere), the rest · Maintainers:
Nathan Chancellor, Nicolas Schier, Linus Torvalds
Previously you had to manually define COMPUTE_HEADER_DEPENDENCIES to enable this feature. It seemed a bit sad that such a useful feature had to be enabled manually. Signed-off-by: Fredrik Kuivinen <redacted> --- Makefile | 13 +++++++++---- 1 files changed, 9 insertions(+), 4 deletions(-)
diff --git a/Makefile b/Makefile
index e40ac0c..3b9efac 100644
--- a/Makefile
+++ b/Makefile@@ -243,10 +243,6 @@ all:: # DEFAULT_EDITOR='$GIT_FALLBACK_EDITOR', # DEFAULT_EDITOR='"C:\Program Files\Vim\gvim.exe" --nofork' # -# Define COMPUTE_HEADER_DEPENDENCIES if your compiler supports the -MMD option -# and you want to avoid rebuilding objects when an unrelated header file -# changes. -# # Define CHECK_HEADER_DEPENDENCIES to check for problems in the hard-coded # dependency rules. #
@@ -1211,6 +1207,15 @@ endif ifdef CHECK_HEADER_DEPENDENCIES COMPUTE_HEADER_DEPENDENCIES = USE_COMPUTED_HEADER_DEPENDENCIES = +else +dep_check = $(shell sh -c \ + ': > ++empty.c; \ + $(CC) -c -MF /dev/null -MMD -MP ++empty.c -o /dev/null 2>&1; \ + echo $$?; \ + $(RM) ++empty.c') +ifeq ($(dep_check),0) +COMPUTE_HEADER_DEPENDENCIES=YesPlease +endif endif ifdef COMPUTE_HEADER_DEPENDENCIES
--
1.7.5.3.368.g8b1b7.dirty