From 19ee5efa61fe5a18b130b91fd319bf90cd717fec Mon Sep 17 00:00:00 2001
From: Anas Nashif <anas.nashif@intel.com>
Date: Sat, 22 Apr 2017 08:10:44 -0400
Subject: [PATCH] build: support building host tools

To speed up builds, this change allows building the needed host tools
that are built for every application and stores them un
${ZEPHYR_BASE}/bin.

Run 'make host-tools' and then define PREBUILT_HOST_TOOLS to reuse the
host tools across multiple builds.

$ make host-tools
  HOSTCC  scripts/basic/fixdep
  HOSTCC  scripts/gen_idt/version.o
  HOSTCC  scripts/gen_idt/gen_idt.o
  HOSTLD  scripts/gen_idt/gen_idt
  HOSTCC  scripts/gen_offset_header/gen_offset_header.o
  HOSTLD  scripts/gen_offset_header/gen_offset_header
  HOSTCC  scripts/kconfig/conf.o
  SHIPPED scripts/kconfig/zconf.tab.c
  SHIPPED scripts/kconfig/zconf.lex.c
  SHIPPED scripts/kconfig/zconf.hash.c
  HOSTCC  scripts/kconfig/zconf.tab.o
  HOSTLD  scripts/kconfig/conf

$ export PREBUILT_HOST_TOOLS=${ZEPHYR_BASE}/bin

$ make -C samples/hello_world

Now you will notice a speedup when building the application!

Change-Id: Ie0aeee7f9a60b1fd49e7e32d78601f03473d73b8
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
---
 Makefile                 | 15 +++++++++++++--
 scripts/kconfig/Makefile |  2 ++
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/Makefile b/Makefile
index 2c819a822a2..2ba656f2efa 100644
--- a/Makefile
+++ b/Makefile
@@ -478,7 +478,7 @@ endif
 
 version_h := include/generated/version.h
 
-no-dot-config-targets := pristine distclean clean mrproper help kconfig-help \
+no-dot-config-targets := pristine distclean clean mrproper help kconfig-help host-tools \
 			 cscope gtags TAGS tags help% %docs check% \
 			 $(version_h) headers_% kernelversion %src-pkg
 
@@ -1065,7 +1065,7 @@ CLEAN_FILES += 	include/generated/generated_dts_board.h \
 		*.bin *.hex *.stat *.strip staticIdt.o linker.cmd
 
 # Directories & files removed with 'make mrproper'
-MRPROPER_DIRS  += include/config usr/include include/generated          \
+MRPROPER_DIRS  += bin include/config usr/include include/generated          \
 		  arch/*/include/generated .tmp_objdiff
 MRPROPER_FILES += .config .config.old .version $(version_h) \
 		  Module.symvers tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS \
@@ -1193,6 +1193,17 @@ $(help-board-dirs): help-%:
 		echo '')
 
 
+
+host-tools:
+	$(Q)$(MAKE) $(build)=scripts/kconfig standalone
+	$(Q)$(MAKE) $(build)=scripts/basic
+	$(Q)$(MAKE) $(build)=scripts/gen_idt
+	$(Q)$(MAKE) $(build)=scripts/gen_offset_header
+	@mkdir -p ${ZEPHYR_BASE}/bin
+	@cp scripts/basic/fixdep scripts/gen_idt/gen_idt scripts/kconfig/conf \
+		scripts/gen_offset_header/gen_offset_header ${ZEPHYR_BASE}/bin
+
+
 # Documentation targets
 # ---------------------------------------------------------------------------
 %docs: FORCE
diff --git a/scripts/kconfig/Makefile b/scripts/kconfig/Makefile
index 5e0230444cb..a15068add38 100644
--- a/scripts/kconfig/Makefile
+++ b/scripts/kconfig/Makefile
@@ -34,6 +34,8 @@ gconfig: $(KCONFIG_BIN_PATH)/gconf
 menuconfig: $(KCONFIG_BIN_PATH)/mconf
 	$< $(Kconfig)
 
+standalone: $(obj)/conf
+
 config: $(KCONFIG_BIN_PATH)/conf
 	$< --oldaskconfig $(Kconfig)