[PATCH 5/7] tools build: Make fixdep helper part of the build process

[Jiri Olsa <jolsa@kernel.org>]

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

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

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

Link: http://lkml.kernel.org/n/tip-iaegu48r5t9k2lttjrvozmb1@git.kernel.org
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
 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 851c420098e7..4d000bc959b4 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 0c5f485521d6..4a96473b180f 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
 
-- 
2.4.3