From 111ee18c31f9bac9436426399355facc79238566 Mon Sep 17 00:00:00 2001 From: Fredrik Kuivinen Date: Thu, 18 Aug 2011 20:34:39 +0200 Subject: [PATCH] Makefile: Use computed header dependencies if the compiler supports it 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. To avoid the small overhead we don't do the auto-detection if COMPUTE_HEADER_DEPENDENCIES is already set. Signed-off-by: Fredrik Kuivinen Acked-by: Jonathan Nieder Signed-off-by: Junio C Hamano --- Makefile | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/Makefile b/Makefile index 89cc6245a..c131439a3 100644 --- a/Makefile +++ b/Makefile @@ -250,10 +250,6 @@ 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. # @@ -1236,6 +1232,15 @@ endif ifdef CHECK_HEADER_DEPENDENCIES COMPUTE_HEADER_DEPENDENCIES = USE_COMPUTED_HEADER_DEPENDENCIES = +else +ifndef COMPUTE_HEADER_DEPENDENCIES +dep_check = $(shell sh -c \ + '$(CC) -c -MF /dev/null -MMD -MP -x c /dev/null -o /dev/null 2>&1; \ + echo $$?') +ifeq ($(dep_check),0) +COMPUTE_HEADER_DEPENDENCIES=YesPlease +endif +endif endif ifdef COMPUTE_HEADER_DEPENDENCIES -- 2.30.2