From ee482fd521a0b3c7c33539c7b1a8d552c18832c3 Mon Sep 17 00:00:00 2001
From: Shinichiro Hamaji <hamaji@google.com>
Date: Mon, 17 Aug 2015 17:38:24 +0900
Subject: [PATCH] Use goma when USE_GOMA=true is set

With USE_GOMA, the path to gomacc in $GOMA_DIR or $HOME/goma
will be appended to CC_WRAPPER and CXX_WRAPPER.

Note this works only with USE_NINJA. Unlike ninja, GNU make
cannot change the parallelism depending on targets. Specifying
-j500 to GNU make would mean you may run 500 local jobs in
parallel, but with -j32 goma will just slow down the build.

Change-Id: I0f571454fd2a5b525ee29b445f7ab8715927ca00
---
 core/config.mk |  1 +
 core/goma.mk   | 58 ++++++++++++++++++++++++++++++++++++++++++++++++++
 core/ninja.mk  |  2 +-
 3 files changed, 60 insertions(+), 1 deletion(-)
 create mode 100644 core/goma.mk

diff --git a/core/config.mk b/core/config.mk
index 78a43eceec..3c53d619ef 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -277,6 +277,7 @@ include $(BUILD_SYSTEM)/combo/select.mk
 endif
 
 include $(BUILD_SYSTEM)/ccache.mk
+include $(BUILD_SYSTEM)/goma.mk
 
 ifdef TARGET_PREFER_32_BIT
 TARGET_PREFER_32_BIT_APPS := true
diff --git a/core/goma.mk b/core/goma.mk
new file mode 100644
index 0000000000..1d44aea93e
--- /dev/null
+++ b/core/goma.mk
@@ -0,0 +1,58 @@
+#
+# Copyright (C) 2015 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+# Notice: this works only with Google's Goma build infrastructure.
+ifneq ($(USE_GOMA),)
+  # Check if USE_NINJA is defined because GNU make won't work well
+  # with goma. Note this file is evaluated twice, once with
+  # USE_NINJA=true by GNU make and once with USE_NINJA=false by kati
+  # which is invoked by GNU make. So, we cannot test the value of
+  # USE_NINJA.
+  ifndef USE_NINJA
+    $(error USE_GOMA=true works only with USE_NINJA=true)
+  endif
+
+  ifdef GOMA_DIR
+    goma_dir := $(GOMA_DIR)
+  else
+    goma_dir := $(HOME)/goma
+  endif
+  goma_ctl := $(goma_dir)/goma_ctl.py
+  goma_cc := $(goma_dir)/gomacc
+
+  $(if $(wildcard $(goma_ctl)),, \
+   $(warning You should have goma in $$GOMA_DIR or $(HOME)/goma) \
+   $(error See go/ma/how-to-use-goma/how-to-use-goma-for-android for detail))
+
+  # Append gomacc to existing *_WRAPPER variables so it's possible to
+  # use both ccache and gomacc.
+  CC_WRAPPER := $(strip $(CC_WRAPPER) $(goma_cc))
+  CXX_WRAPPER := $(strip $(CXX_WRAPPER) $(goma_cc))
+
+  # Ninja file generated by kati uses this for remote jobs (i.e.,
+  # commands which contain gomacc). Note the parallelism of all other
+  # jobs will be limited the number of cores.
+  KATI_REMOTE_NUM_JOBS_FLAG := --remote_num_jobs=500
+
+  # gomacc can start goma client's daemon process automatically, but
+  # it is safer and faster to start up it beforehand. We run this as a
+  # background process so this won't slow down the build.
+  $(shell $(goma_ctl) ensure_start &> /dev/null &)
+
+  goma_cc :=
+  goma_ctl :=
+  goma_dir :=
+endif
diff --git a/core/ninja.mk b/core/ninja.mk
index 057f091d3e..3dcc65c93b 100644
--- a/core/ninja.mk
+++ b/core/ninja.mk
@@ -38,7 +38,7 @@ $(KATI_OUTPUTS): kati.intermediate $(KATI_FORCE)
 kati.intermediate: $(KATI)
 	@echo Running kati to generate build.ninja...
 	@#TODO: use separate ninja file for mm or single target build
-	$(hide) $(KATI) --ninja --ninja_dir=$(PRODUCT_OUT) --regen --ignore_dirty=$(OUT_DIR)/% --ignore_optional_include=$(OUT_DIR)/%.P --detect_android_echo --use_find_emulator -f build/core/main.mk $(ANDROID_TARGETS) USE_NINJA=false
+	$(hide) $(KATI) --ninja --ninja_dir=$(PRODUCT_OUT) --regen --ignore_dirty=$(OUT_DIR)/% --ignore_optional_include=$(OUT_DIR)/%.P --detect_android_echo --use_find_emulator $(KATI_REMOTE_NUM_JOBS_FLAG) -f build/core/main.mk $(ANDROID_TARGETS) USE_NINJA=false
 
 KATI_CXX := $(CLANG_CXX) $(CLANG_HOST_GLOBAL_CPPFLAGS)
 KATI_LD := $(CLANG_CXX) $(CLANG_HOST_GLOBAL_LDFLAGS)