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| author | Jonathan Nieder <jrnieder@gmail.com> | 2011-11-18 23:23:24 (GMT) |
|---|---|---|
| committer | Junio C Hamano <gitster@pobox.com> | 2013-02-02 02:09:33 (GMT) |
| commit | 69789347134b4b04411ae22f6eb516552b6ac365 (patch) | |
| tree | 37127177980d8ca444160f4ad0429f67a6e6a5e5 /Makefile | |
| parent | 7e2010537e96d0a1144520222f20ba1dc3d61441 (diff) | |
| download | git-69789347134b4b04411ae22f6eb516552b6ac365.zip git-69789347134b4b04411ae22f6eb516552b6ac365.tar.gz git-69789347134b4b04411ae22f6eb516552b6ac365.tar.bz2 | |
Makefile: explicitly set target name for autogenerated dependencies
"gcc -MF depfile -MMD -MP -c -o path/to/file.o" produces a makefile
snippet named "depfile" describing what files are needed to build the
target given by "-o". When ccache versions before v3.0pre0~187 (Fix
handling of the -MD and -MDD options, 2009-11-01) run, they execute
gcc -MF depfile -MMD -MP -E
instead to get the final content for hashing. Notice that the "-c -o"
combination is replaced by "-E". The result is a target name without
a leading path.
Thus when building git with such versions of ccache with
COMPUTE_HEADER_DEPENDENCIES enabled, the generated makefile snippets
define dependencies for the wrong target:
$ make builtin/add.o
GIT_VERSION = 1.7.8.rc3
* new build flags or prefix
CC builtin/add.o
$ head -1 builtin/.depend/add.o.d
add.o: builtin/add.c cache.h git-compat-util.h compat/bswap.h strbuf.h \
After a change in a header file, object files in a subdirectory are
not automatically rebuilt by "make":
$ touch cache.h
$ make builtin/add.o
$
Luckily we can prevent trouble by explicitly supplying the name of the
target to ccache and gcc, using the -MQ option. Do so.
Reported-and-tested-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Reported-by: : 허종만 <jongman.heo@samsung.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'Makefile')
| -rw-r--r-- | Makefile | 5 |
1 files changed, 3 insertions, 2 deletions
@@ -1388,7 +1388,8 @@ 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; \ + -c -MF /dev/null -MQ /dev/null -MMD -MP \ + -x c /dev/null -o /dev/null 2>&1; \ echo $$?) ifeq ($(dep_check),0) override COMPUTE_HEADER_DEPENDENCIES = yes @@ -2211,7 +2212,7 @@ $(dep_dirs): missing_dep_dirs := $(filter-out $(wildcard $(dep_dirs)),$(dep_dirs)) dep_file = $(dir $@).depend/$(notdir $@).d -dep_args = -MF $(dep_file) -MMD -MP +dep_args = -MF $(dep_file) -MQ $@ -MMD -MP ifdef CHECK_HEADER_DEPENDENCIES $(error cannot compute header dependencies outside a normal build. \ Please unset CHECK_HEADER_DEPENDENCIES and try again) |