From d1600411495c0bd52dd0f3809ed6bf0d6faca349 Mon Sep 17 00:00:00 2001
From: Dan Albert <danalbert@google.com>
Date: Wed, 10 Jun 2015 16:33:43 -0700
Subject: [PATCH] Force some clang Werrors that *will* break things.

Clang is really aggressive at optimizing a handful of cases (read:
clang will ruin your day some if you write bad code). Fortunately, it
also emits a warning when it's about to do this.

To prevent anyone from suffering from these optimizations, make these
warnings errors and make them impossible to disable.

Change-Id: I5e10bb0fc2ca23190017da716b3b84635577a0bd
---
 core/binary.mk      | 6 ++++++
 core/config.mk      | 7 ++++++-
 core/definitions.mk | 9 ++++++---
 core/product.mk     | 1 +
 4 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/core/binary.mk b/core/binary.mk
index d3d050e68..ba559354f 100644
--- a/core/binary.mk
+++ b/core/binary.mk
@@ -40,6 +40,8 @@ my_shared_libraries := $(LOCAL_SHARED_LIBRARIES)
 my_cflags := $(LOCAL_CFLAGS)
 my_conlyflags := $(LOCAL_CONLYFLAGS)
 my_cppflags := $(LOCAL_CPPFLAGS)
+my_cflags_no_override := $(GLOBAL_CFLAGS_NO_OVERRIDE)
+my_cppflags_no_override := $(GLOBAL_CPPFLAGS_NO_OVERRIDE)
 my_ldflags := $(LOCAL_LDFLAGS)
 my_ldlibs := $(LOCAL_LDLIBS)
 my_asflags := $(LOCAL_ASFLAGS)
@@ -1031,6 +1033,8 @@ ifeq ($(my_clang),true)
 my_cflags += $(LOCAL_CLANG_CFLAGS)
 my_conlyflags += $(LOCAL_CLANG_CONLYFLAGS)
 my_cppflags += $(LOCAL_CLANG_CPPFLAGS)
+my_cflags_no_override += $(GLOBAL_CLANG_CFLAGS_NO_OVERRIDE)
+my_cppflags_no_override += $(GLOBAL_CLANG_CPPFLAGS_NO_OVERRIDE)
 my_asflags += $(LOCAL_CLANG_ASFLAGS)
 my_ldflags += $(LOCAL_CLANG_LDFLAGS)
 my_cflags += $(LOCAL_CLANG_CFLAGS_$($(my_prefix)$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH)) $(LOCAL_CLANG_CFLAGS_$(my_32_64_bit_suffix))
@@ -1055,6 +1059,8 @@ $(LOCAL_INTERMEDIATE_TARGETS): PRIVATE_ASFLAGS := $(my_asflags)
 $(LOCAL_INTERMEDIATE_TARGETS): PRIVATE_CONLYFLAGS := $(my_conlyflags)
 $(LOCAL_INTERMEDIATE_TARGETS): PRIVATE_CFLAGS := $(my_cflags)
 $(LOCAL_INTERMEDIATE_TARGETS): PRIVATE_CPPFLAGS := $(my_cppflags)
+$(LOCAL_INTERMEDIATE_TARGETS): PRIVATE_CFLAGS_NO_OVERRIDE := $(my_cflags_no_override)
+$(LOCAL_INTERMEDIATE_TARGETS): PRIVATE_CPPFLAGS_NO_OVERRIDE := $(my_cppflags_no_override)
 $(LOCAL_INTERMEDIATE_TARGETS): PRIVATE_RTTI_FLAG := $(LOCAL_RTTI_FLAG)
 $(LOCAL_INTERMEDIATE_TARGETS): PRIVATE_DEBUG_CFLAGS := $(debug_cflags)
 $(LOCAL_INTERMEDIATE_TARGETS): PRIVATE_C_INCLUDES := $(my_c_includes)
diff --git a/core/config.mk b/core/config.mk
index 502dd7a73..07c392adb 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -117,10 +117,15 @@ COMMON_RELEASE_CFLAGS:= -DNDEBUG -UDEBUG
 COMMON_GLOBAL_CPPFLAGS:= $(COMMON_GLOBAL_CFLAGS) -Wsign-promo -std=gnu++11
 COMMON_RELEASE_CPPFLAGS:= $(COMMON_RELEASE_CFLAGS)
 
-GLOBAL_CFLAGS_NO_OVERRIDE :=  \
+GLOBAL_CFLAGS_NO_OVERRIDE := \
     -Werror=int-to-pointer-cast \
     -Werror=pointer-to-int-cast \
 
+GLOBAL_CLANG_CFLAGS_NO_OVERRIDE := \
+    -Werror=address-of-temporary \
+    -Werror=null-dereference \
+    -Werror=return-type \
+
 GLOBAL_CPPFLAGS_NO_OVERRIDE :=
 
 # Set the extensions used for various packages
diff --git a/core/definitions.mk b/core/definitions.mk
index db51f9497..c1841dc2b 100644
--- a/core/definitions.mk
+++ b/core/definitions.mk
@@ -1032,8 +1032,8 @@ $(hide) $(PRIVATE_CXX) \
 	$(PRIVATE_CFLAGS) \
 	$(PRIVATE_CPPFLAGS) \
 	$(PRIVATE_DEBUG_CFLAGS) \
-	$(GLOBAL_CFLAGS_NO_OVERRIDE) \
-	$(GLOBAL_CPPFLAGS_NO_OVERRIDE) \
+	$(PRIVATE_CFLAGS_NO_OVERRIDE) \
+	$(PRIVATE_CPPFLAGS_NO_OVERRIDE) \
 	-MD -MF $(patsubst %.o,%.d,$@) -o $@ $<
 $(transform-d-to-p)
 endef
@@ -1070,7 +1070,7 @@ $(call transform-c-or-s-to-o-no-deps, \
     $(PRIVATE_CFLAGS) \
     $(PRIVATE_CONLYFLAGS) \
     $(PRIVATE_DEBUG_CFLAGS) \
-    $(GLOBAL_CFLAGS_NO_OVERRIDE))
+    $(PRIVATE_CFLAGS_NO_OVERRIDE))
 endef
 
 define transform-s-to-o-no-deps
@@ -1137,6 +1137,8 @@ $(hide) $(PRIVATE_CXX) \
 	$(PRIVATE_CFLAGS) \
 	$(PRIVATE_CPPFLAGS) \
 	$(PRIVATE_DEBUG_CFLAGS) \
+	$(PRIVATE_CFLAGS_NO_OVERRIDE) \
+	$(PRIVATE_CPPFLAGS_NO_OVERRIDE) \
 	-MD -MF $(patsubst %.o,%.d,$@) -o $@ $<
 $(transform-d-to-p)
 endef
@@ -1163,6 +1165,7 @@ $(hide) $(PRIVATE_CC) \
 	    $(PRIVATE_HOST_GLOBAL_CONLYFLAGS) \
 	 ) \
 	$(1) \
+	$(PRIVATE_CFLAGS_NO_OVERRIDE) \
 	-MD -MF $(patsubst %.o,%.d,$@) -o $@ $<
 endef
 
diff --git a/core/product.mk b/core/product.mk
index 46fad8951..ac5f85440 100644
--- a/core/product.mk
+++ b/core/product.mk
@@ -270,6 +270,7 @@ _product_stash_var_list += \
 _product_stash_var_list += \
 	GLOBAL_CFLAGS_NO_OVERRIDE \
 	GLOBAL_CPPFLAGS_NO_OVERRIDE \
+	GLOBAL_CLANG_CFLAGS_NO_OVERRIDE \
 
 #
 # Stash values of the variables in _product_stash_var_list.