From 05909fae9ffd8071411d961db23b05f33615c82a Mon Sep 17 00:00:00 2001
From: Dan Willemsen <dwillemsen@google.com>
Date: Sun, 19 Mar 2017 13:22:45 -0700
Subject: [PATCH] Add LOCAL_EXPORT_CFLAGS for Soong

This lets Soong pass -isystem or -I as necessary (or potentially, even
other cflags in the future).

This is not available for Android.mk use, nor exposed directly to
Android.bp users.

Test: m -j
Change-Id: Id37d4692d5fbddce467bd777903b20169f44dd6e
---
 core/binary.mk            | 16 +++++++++++-----
 core/clear_vars.mk        |  1 +
 core/prebuilt_internal.mk | 16 +++++++++++-----
 3 files changed, 23 insertions(+), 10 deletions(-)

diff --git a/core/binary.mk b/core/binary.mk
index 3eb77604b..32f8ebea3 100644
--- a/core/binary.mk
+++ b/core/binary.mk
@@ -1738,7 +1738,14 @@ $(LOCAL_INSTALLED_MODULE): | $(installed_static_library_notice_file_targets)
 # Export includes
 ###########################################################
 export_includes := $(intermediates)/export_includes
-$(export_includes): PRIVATE_EXPORT_C_INCLUDE_DIRS := $(my_export_c_include_dirs)
+export_cflags := $(foreach d,$(my_export_c_include_dirs),-I $(d))
+# Soong exports cflags instead of include dirs, so that -isystem can be included.
+ifeq ($(LOCAL_MODULE_MAKEFILE),$(SOONG_ANDROID_MK))
+export_cflags += $(LOCAL_EXPORT_CFLAGS)
+else ifdef LOCAL_EXPORT_CFLAGS
+$(call pretty-error,LOCAL_EXPORT_CFLAGS can only be used by Soong, use LOCAL_EXPORT_C_INCLUDE_DIRS instead)
+endif
+$(export_includes): PRIVATE_EXPORT_CFLAGS := $(export_cflags)
 # Headers exported by whole static libraries are also exported by this library.
 export_include_deps := $(strip \
    $(foreach l,$(my_whole_static_libraries), \
@@ -1761,10 +1768,8 @@ $(export_includes): PRIVATE_REEXPORTED_INCLUDES := $(export_include_deps)
 $(export_includes) : $(my_export_c_include_deps) $(my_generated_sources) $(export_include_deps) $(LOCAL_EXPORT_C_INCLUDE_DEPS)
 	@echo Export includes file: $< -- $@
 	$(hide) mkdir -p $(dir $@) && rm -f $@.tmp && touch $@.tmp
-ifdef my_export_c_include_dirs
-	$(hide) for d in $(PRIVATE_EXPORT_C_INCLUDE_DIRS); do \
-	        echo "-I $$d" >> $@.tmp; \
-	        done
+ifdef export_cflags
+	$(hide) echo "$(PRIVATE_EXPORT_CFLAGS)" >>$@.tmp
 endif
 ifdef export_include_deps
 	$(hide) for f in $(PRIVATE_REEXPORTED_INCLUDES); do \
@@ -1776,6 +1781,7 @@ endif
 	else \
 	  mv $@.tmp $@ ; \
 	fi
+export_cflags :=
 
 # Kati adds restat=1 to ninja. GNU make does nothing for this.
 .KATI_RESTAT: $(export_includes)
diff --git a/core/clear_vars.mk b/core/clear_vars.mk
index c2ae8b835..37d8364c8 100644
--- a/core/clear_vars.mk
+++ b/core/clear_vars.mk
@@ -69,6 +69,7 @@ LOCAL_DX_FLAGS:=
 LOCAL_EMMA_COVERAGE_FILTER:=
 LOCAL_EMMA_INSTRUMENT:=
 LOCAL_ERROR_PRONE_FLAGS:=
+LOCAL_EXPORT_CFLAGS:=
 LOCAL_EXPORT_C_INCLUDE_DEPS:=
 LOCAL_EXPORT_C_INCLUDE_DIRS:=
 LOCAL_EXPORT_HEADER_LIBRARY_HEADERS:=
diff --git a/core/prebuilt_internal.mk b/core/prebuilt_internal.mk
index 36a32804b..20ffc872c 100644
--- a/core/prebuilt_internal.mk
+++ b/core/prebuilt_internal.mk
@@ -126,17 +126,23 @@ else  # my_strip_module and my_pack_module_relocations not true
 
 ifdef prebuilt_module_is_a_library
 export_includes := $(intermediates)/export_includes
-$(export_includes): PRIVATE_EXPORT_C_INCLUDE_DIRS := $(LOCAL_EXPORT_C_INCLUDE_DIRS)
+export_cflags := $(foreach d,$(LOCAL_EXPORT_C_INCLUDE_DIRS),-I $(d))
+# Soong exports cflags instead of include dirs, so that -isystem can be included.
+ifeq ($(LOCAL_MODULE_MAKEFILE),$(SOONG_ANDROID_MK))
+export_cflags += $(LOCAL_EXPORT_CFLAGS)
+else ifdef LOCAL_EXPORT_CFLAGS
+$(call pretty-error,LOCAL_EXPORT_CFLAGS can only be used by Soong, use LOCAL_EXPORT_C_INCLUDE_DIRS instead)
+endif
+$(export_includes): PRIVATE_EXPORT_CFLAGS := $(export_cflags)
 $(export_includes): $(LOCAL_EXPORT_C_INCLUDE_DEPS)
 	@echo Export includes file: $< -- $@
 	$(hide) mkdir -p $(dir $@) && rm -f $@
-ifdef LOCAL_EXPORT_C_INCLUDE_DIRS
-	$(hide) for d in $(PRIVATE_EXPORT_C_INCLUDE_DIRS); do \
-	        echo "-I $$d" >> $@; \
-	        done
+ifdef export_cflags
+	$(hide) echo "$(PRIVATE_EXPORT_CFLAGS)" >$@
 else
 	$(hide) touch $@
 endif
+export_cflags :=
 
 my_link_type := $(intermediates)/link_type
 $(my_link_type): PRIVATE_LINK_TYPE := native:$(if $(LOCAL_SDK_VERSION),ndk,platform)