Build: Fix parallel build
2 problems were found, but are in one change to avoid submitting a patch
that might fail to build. The problems were:
1. The macro MAKE_PREREQ_DIR has a minor bug, in that it is capable of
generating recursive dependencies.
2. The inclusion of BUILD_DIR in TEMP_OBJ_DIRS left no explicit
dependency, BUILD_DIR might not exist when subdirectories are
created by a thread on another CPU.
This fix corrects these with the following changes:
1. MAKE_PREREQ_DIR does nothing for a direct self dependency.
2. BUILD_DIR is built using MAKE_PREREQ_DIR.
3. BUILD_DIR is an explicit prerequisite of all OBJ_DIRS.
Change-Id: I938cddea4a006df225c02a47b9cf759212f27fb7
Signed-off-by: Evan Lloyd <evan.lloyd@arm.com>
diff --git a/make_helpers/unix.mk b/make_helpers/unix.mk
index ab60435..6f70200 100644
--- a/make_helpers/unix.mk
+++ b/make_helpers/unix.mk
@@ -1,5 +1,5 @@
#
-# Copyright (c) 2016, ARM Limited and Contributors. All rights reserved.
+# Copyright (c) 2016-2017, ARM Limited and Contributors. All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
@@ -67,11 +67,14 @@
# ${1} is the directory to be generated.
# ${2} is optional, and allows a prerequisite to be specified.
+ # Do nothing if $1 == $2, to ignore self dependencies.
define MAKE_PREREQ_DIR
+ ifneq (${1},${2})
${1} : ${2}
${Q}mkdir -p "${1}"
+ endif
endef
define SHELL_REMOVE_DIR