[tip:perf/core] tools build: Make the fixdep helper part of the build process

[tip-bot for Jiri Olsa <tipbot@zytor.com>]

Commit-ID:  9fb81323eb3085b6a47fe81d78541958ae7eaea3
Gitweb:     http://git.kernel.org/tip/9fb81323eb3085b6a47fe81d78541958ae7eaea3
Author:     Jiri Olsa <jolsa@kernel.org>
AuthorDate: Wed, 23 Sep 2015 12:34:00 +0200
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Mon, 28 Sep 2015 15:50:55 -0300

tools build: Make the fixdep helper part of the build process

Making the fixdep helper to be invoked within dep-cmd.

Each user of the build framework needs to make sure fixdep exists before
executing the build itself.

If the build doesn't find fixdep, it falls back to the old style
dependency tracking.

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>
Link: http://lkml.kernel.org/r/1443004442-32660-6-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/build/Build.include  | 10 ++++++++--
 tools/build/Makefile.build |  7 +++++++
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/tools/build/Build.include b/tools/build/Build.include
index 851c420..4d000bc 100644
--- a/tools/build/Build.include
+++ b/tools/build/Build.include
@@ -58,8 +58,14 @@ any-prereq = $(filter-out $(PHONY),$?) $(filter-out $(PHONY) $(wildcard $^),$^)
 # Copy dependency data into .cmd file
 #  - gcc -M dependency info
 #  - command line to create object 'cmd_object :='
-dep-cmd = cat $(depfile) >  $(dot-target).cmd; \
-          printf '%s\n' 'cmd_$@ := $(make-cmd)' >> $(dot-target).cmd
+dep-cmd = $(if $(wildcard $(fixdep)),                                           \
+           $(fixdep) $(depfile) $@ '$(make-cmd)' > $(dot-target).tmp;           \
+           rm -f $(depfile);                                                    \
+           mv -f $(dot-target).tmp $(dot-target).cmd,                           \
+           printf '\# cannot find fixdep (%s)\n' $(fixdep) > $(dot-target).cmd; \
+           printf '\# using basic dep data\n\n' >> $(dot-target).cmd;           \
+           cat $(depfile) >> $(dot-target).cmd;                                 \
+           printf '%s\n' 'cmd_$@ := $(make-cmd)' >> $(dot-target).cmd)
 
 ###
 # if_changed_dep  - execute command if any prerequisite is newer than
diff --git a/tools/build/Makefile.build b/tools/build/Makefile.build
index 0c5f485..4a96473 100644
--- a/tools/build/Makefile.build
+++ b/tools/build/Makefile.build
@@ -21,6 +21,13 @@ endif
 
 build-dir := $(srctree)/tools/build
 
+# Define $(fixdep) for dep-cmd function
+ifeq ($(OUTPUT),)
+  fixdep := $(build-dir)/fixdep
+else
+  fixdep := $(OUTPUT)/fixdep
+endif
+
 # Generic definitions
 include $(build-dir)/Build.include