Commit Graph

2 Commits

Author SHA1 Message Date
Jiri Olsa 5e50426d5d tools build: Use fixdep with OUTPUT path prefix
Adding OUTPUT path prefix for fixdep target so we use it properly in out
of tree builds.

If the fixdep already existed in the tree, the out of tree build would
see it already exist and did not build the out of tree version, as
reported by Arnaldo:

  [acme@zoo linux]$ make O=/tmp/build/perf -C tools/perf
  make: Entering directory '/home/git/linux/tools/perf'
    BUILD:   Doing 'make -j4' parallel build
  make[2]: Nothing to be done for 'fixdep'.
  make: Leaving directory '/home/git/linux/tools/perf'

Reported-and-Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/20151126185055.GC19410@krava.brq.redhat.com
[ Fixed conflict with 5725dd8fa8 ("tools build: Clean CFLAGS and LDFLAGS for fixdep") ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-11-26 16:32:24 -03:00
Jiri Olsa 9f7ef9854e tools build: Add fixdep dependency helper
For dependency tracking we currently use targets that fall out of the
gcc -MD command. We store this info in the .cmd file and include as
makefile during the build.

This format put object as target and all the c and header files as
dependencies, like:

  util/abspath.o: util/abspath.c /usr/include/stdc-predef.h util/cache.h \
   /usr/include/bits/wordsize.h /usr/include/gnu/stubs.h \
   ...

If any of those dependency header files (krava.h below) is removed the
build fails on:

  make[1]: *** No rule to make target 'krava.h', needed by 'inc.o'.  Stop.

This patch adds fixdep helper, that is used by kbuild to alter the shape
of the object dependencies like:

  source_util/abspath.o := util/abspath.c

  deps_util/abspath.o := \
    /usr/include/stdc-predef.h \
    util/cache.h \
    ...

  util/abspath.o: $(deps_util/abspath.o)

  $(deps_util/abspath.o):

With this format the header removal won't make the build fail, because
it'll be picked up by the last empty target defined for each header.

As previously mentioned the fixdep tool is taken from kbuild. It's not
complete backport, only the part that alters the standard dependency
info was taken, the part that adds the CONFIG_* dependency logic will be
probably taken later on.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Kai Germaschewski <kai.germaschewski@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1443004442-32660-4-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-09-28 15:50:55 -03:00