From 127da9e4aa78d4e26484db2a8daa3f05d90e27fa Mon Sep 17 00:00:00 2001
From: Ying Wang <wangying@google.com>
Date: Tue, 22 Sep 2015 14:37:53 -0700
Subject: [PATCH] Use md5sum as the build.ninja filename suffix if the suffix
 gets too long.

Use md5sum as the build.ninja filename suffix if the suffix is longer
than 64 characters. Also store the original suffix in a corresponding
.suf file for human lookup.
This fixes the "File name too long" error when kati tries to write to
build.ninja with the long original suffix.

Bug: 24302576
Change-Id: Ie04b0c14e1a9d593aa5c2a6b357b19a9e8a7158e
---
 core/config.mk |  4 ++++
 core/ninja.mk  | 19 ++++++++++++++++++-
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/core/config.mk b/core/config.mk
index e7a1d2020..dd0dfc2d8 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -23,6 +23,10 @@ define newline
 
 
 endef
+# The pound character "#"
+define pound
+#
+endef
 # Unfortunately you can't simply define backslash as \ or \\.
 backslash := \a
 backslash := $(patsubst %a,%,$(backslash))
diff --git a/core/ninja.mk b/core/ninja.mk
index 56b4ac565..2aa0b283a 100644
--- a/core/ninja.mk
+++ b/core/ninja.mk
@@ -73,8 +73,26 @@ ifneq ($(BUILD_MODULES_IN_PATHS),)
 KATI_NINJA_SUFFIX := $(KATI_NINJA_SUFFIX)-mmma-$(call replace_space_and_slash,$(BUILD_MODULES_IN_PATHS))
 endif
 
+my_checksum_suffix :=
+ifneq ($(KATI_NINJA_SUFFIX),)
+my_ninja_suffix_too_long := $(filter 1, $(shell v='$(KATI_NINJA_SUFFIX)' && echo $$(($${$(pound)v} > 64))))
+ifneq ($(my_ninja_suffix_too_long),)
+# Replace the suffix with a checksum if it gets too long.
+my_checksum_suffix := $(KATI_NINJA_SUFFIX)
+KATI_NINJA_SUFFIX := -$(word 1, $(shell echo $(my_checksum_suffix) | $(MD5SUM)))
+endif
+endif
+
 KATI_BUILD_NINJA := $(PRODUCT_OUT)/build$(KATI_NINJA_SUFFIX).ninja
 KATI_NINJA_SH := $(PRODUCT_OUT)/ninja$(KATI_NINJA_SUFFIX).sh
+
+# Write out a file mapping checksum to the real suffix.
+ifneq ($(my_checksum_suffix),)
+my_ninja_suffix_file := $(basename $(KATI_BUILD_NINJA)).suf
+$(shell mkdir -p $(dir $(my_ninja_suffix_file)) && \
+    echo $(my_checksum_suffix) > $(my_ninja_suffix_file))
+endif
+
 KATI_OUTPUTS := $(KATI_BUILD_NINJA) $(KATI_NINJA_SH)
 
 ifeq (,$(NINJA_STATUS))
@@ -115,7 +133,6 @@ $(KATI_OUTPUTS): kati.intermediate $(KATI_FORCE)
 .INTERMEDIATE: kati.intermediate
 kati.intermediate: $(KATI) $(MAKEPARALLEL)
 	@echo Running kati to generate build$(KATI_NINJA_SUFFIX).ninja...
-	@#TODO: use separate ninja file for mm or single target build
 	+$(hide) $(KATI_MAKEPARALLEL) $(KATI) --ninja --ninja_dir=$(PRODUCT_OUT) --ninja_suffix=$(KATI_NINJA_SUFFIX) --regen --ignore_dirty=$(OUT_DIR)/% --ignore_optional_include=$(OUT_DIR)/%.P --detect_android_echo --use_find_emulator $(KATI_REMOTE_NUM_JOBS_FLAG) -f build/core/main.mk $(or $(KATI_TARGETS),--gen_all_phony_targets) USE_NINJA=false
 
 KATI_CXX := $(CLANG_CXX) $(CLANG_HOST_GLOBAL_CPPFLAGS)
-- 
2.11.0