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authorJonathan Nieder <jrnieder@gmail.com>2011-11-18 03:58:21 -0600
committerJunio C Hamano <gitster@pobox.com>2011-11-18 11:35:08 -0800
commit024c843d472658a3dabb344c843c9242c2f7e4de (patch)
tree35cfe336eb20bbe6ede89574fbe21ab2b2222d20
parent4c00c852b3f2596f246811ca933eef357183581b (diff)
downloadgit-024c843d472658a3dabb344c843c9242c2f7e4de.tar.gz
git-024c843d472658a3dabb344c843c9242c2f7e4de.tar.xz
Makefile: add option to disable automatic dependency generation
Now that the COMPUTE_HEADER_DEPENDENCIES feature is turned on automatically for compilers that support it (see v1.7.8-rc0~142^2~1, 2011-08-18), there is no easy way to force it off. For example, setting COMPUTE_HEADER_DEPENDENCIES to the empty string in config.mak just tells the makefile to treat it as undefined and run a test command to see if the -MMD option is supported. So allow setting COMPUTE_HEADER_DEPENDENCIES=no to explicitly force the feature off. The new semantics: - "yes" means to explicitly enable the feature - "no" means to disable it - "auto" means to autodetect The default is still "auto". Any value other than these three will cause the build to error out with a descriptive message so typos and stale settings in config.mak don't result in mysterious behavior. Makefile:1278: *** please set COMPUTE_HEADER_DEPENDENCIES to yes, no, or auto (not "1"). Stop. So now when someone using a compiler without -MMD support reports trouble building git, you can reproduce it by running "make COMPUTE_HEADER_DEPENDENCIES=no". Suggested-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Improved-by: Junio C Hamano <gitster@pobox.com> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Tested-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
-rw-r--r--Makefile31
1 files changed, 24 insertions, 7 deletions
diff --git a/Makefile b/Makefile
index 34ac79578..b1c80a678 100644
--- a/Makefile
+++ b/Makefile
@@ -250,6 +250,12 @@ all::
# DEFAULT_EDITOR='$GIT_FALLBACK_EDITOR',
# DEFAULT_EDITOR='"C:\Program Files\Vim\gvim.exe" --nofork'
#
+# Define COMPUTE_HEADER_DEPENDENCIES to "yes" if you want dependencies on
+# header files to be automatically computed, to avoid rebuilding objects when
+# an unrelated header file changes. Define it to "no" to use the hard-coded
+# dependency rules. The default is "auto", which means to use computed header
+# dependencies if your compiler is detected to support it.
+#
# Define CHECK_HEADER_DEPENDENCIES to check for problems in the hard-coded
# dependency rules.
#
@@ -1246,21 +1252,32 @@ endif
endif
ifdef CHECK_HEADER_DEPENDENCIES
-COMPUTE_HEADER_DEPENDENCIES =
+COMPUTE_HEADER_DEPENDENCIES = no
USE_COMPUTED_HEADER_DEPENDENCIES =
-else
+endif
+
ifndef COMPUTE_HEADER_DEPENDENCIES
+COMPUTE_HEADER_DEPENDENCIES = auto
+endif
+
+ifeq ($(COMPUTE_HEADER_DEPENDENCIES),auto)
dep_check = $(shell $(CC) $(ALL_CFLAGS) \
-c -MF /dev/null -MMD -MP -x c /dev/null -o /dev/null 2>&1; \
echo $$?)
ifeq ($(dep_check),0)
-COMPUTE_HEADER_DEPENDENCIES=YesPlease
-endif
+override COMPUTE_HEADER_DEPENDENCIES = yes
+else
+override COMPUTE_HEADER_DEPENDENCIES = no
endif
endif
-ifdef COMPUTE_HEADER_DEPENDENCIES
+ifeq ($(COMPUTE_HEADER_DEPENDENCIES),yes)
USE_COMPUTED_HEADER_DEPENDENCIES = YesPlease
+else
+ifneq ($(COMPUTE_HEADER_DEPENDENCIES),no)
+$(error please set COMPUTE_HEADER_DEPENDENCIES to yes, no, or auto \
+(not "$(COMPUTE_HEADER_DEPENDENCIES)"))
+endif
endif
ifdef SANE_TOOL_PATH
@@ -1907,7 +1924,7 @@ OBJECTS := $(GIT_OBJS) $(XDIFF_OBJS) $(VCSSVN_OBJS)
dep_files := $(foreach f,$(OBJECTS),$(dir $f).depend/$(notdir $f).d)
dep_dirs := $(addsuffix .depend,$(sort $(dir $(OBJECTS))))
-ifdef COMPUTE_HEADER_DEPENDENCIES
+ifeq ($(COMPUTE_HEADER_DEPENDENCIES),yes)
$(dep_dirs):
@mkdir -p $@
@@ -1920,7 +1937,7 @@ Please unset CHECK_HEADER_DEPENDENCIES and try again)
endif
endif
-ifndef COMPUTE_HEADER_DEPENDENCIES
+ifneq ($(COMPUTE_HEADER_DEPENDENCIES),yes)
ifndef CHECK_HEADER_DEPENDENCIES
dep_dirs =
missing_dep_dirs =