Fix pch handling for tagged sources.

Still generate the one precompiled header for the default
configuration, but don't use it for sources that have additional tags
(.arm or .neon, shouldn't affect non-ARM32).

Patch contributed by @DoDoENT.

Bug: #14
Change-Id: I1fff1599b3f30e69134aed4972117745bc9c053a

build/core/build-binary.mk

@@ -438,13 +438,22 @@ ifneq (,$(LOCAL_PCH))
     # Build PCH
     $(call compile-cpp-source,$(LOCAL_PCH),$(LOCAL_BUILT_PCH).gch)
 
-    # All obj files are dependent on the PCH
-    $(foreach src,$(filter $(all_cpp_patterns),$(LOCAL_SRC_FILES)),\
+    # Filter obj files that are dependent on the PCH (only those without tags)
+    ifeq (true,$(LOCAL_ARM_NEON))
+        TAGS_TO_FILTER=arm
+    else
+        TAGS_TO_FILTER=arm neon
+    endif
+
+    allowed_src := $(foreach src,$(filter $(all_cpp_patterns),$(LOCAL_SRC_FILES)),\
+        $(if $(filter $(TAGS_TO_FILTER),$(LOCAL_SRC_FILES_TAGS.$(src))),,$(src))\
+    )
+    # All files without tags depend on PCH
+    $(foreach src,$(allowed_src),\
         $(eval $(LOCAL_OBJS_DIR)/$(call get-object-name,$(src)) : $(LOCAL_OBJS_DIR)/$(LOCAL_BUILT_PCH).gch)\
     )
-
-    # Files from now on build with PCH
-    LOCAL_CPPFLAGS += -Winvalid-pch -include $(LOCAL_OBJS_DIR)/$(LOCAL_BUILT_PCH)
+    # Make sure those files are built with PCH
+    $(call add-src-files-target-cflags,$(allowed_src),-Winvalid-pch -include $(LOCAL_OBJS_DIR)/$(LOCAL_BUILT_PCH))
 
     # Insert PCH dir at beginning of include search path
     LOCAL_C_INCLUDES := \

tests/build/pch-tags/jni/Android.mk

@@ -0,0 +1,22 @@
+LOCAL_PATH := $(call my-dir)
+
+include $(CLEAR_VARS)
+LOCAL_MODULE := pch
+LOCAL_PCH := stdafx.h
+LOCAL_SRC_FILES := foo.cpp bar.cpp
+LOCAL_CFLAGS := -Werror
+include $(BUILD_SHARED_LIBRARY)
+
+include $(CLEAR_VARS)
+LOCAL_MODULE := pch-arm
+LOCAL_PCH := stdafx.h
+LOCAL_SRC_FILES := foo.cpp bar.cpp.arm
+LOCAL_CFLAGS := -Werror
+include $(BUILD_SHARED_LIBRARY)
+
+include $(CLEAR_VARS)
+LOCAL_MODULE := pch-neon
+LOCAL_PCH := stdafx.h
+LOCAL_SRC_FILES := foo.cpp bar.cpp.neon
+LOCAL_CFLAGS := -Werror
+include $(BUILD_SHARED_LIBRARY)

tests/build/pch-tags/jni/stdafx.h

@@ -0,0 +1 @@
+