diff --git a/core/clang/config.mk b/core/clang/config.mk
index 6887522..0c5e963 100644
--- a/core/clang/config.mk
+++ b/core/clang/config.mk
@@ -1,7 +1,8 @@
 ## Clang configurations.
 
 LLVM_PREBUILTS_VERSION := 3.6
-LLVM_PREBUILTS_PATH := prebuilts/clang/$(BUILD_OS)-x86/host/$(LLVM_PREBUILTS_VERSION)/bin
+FORCE_BUILD_SANITIZER_SHARED_OBJECTS := true
+LLVM_PREBUILTS_PATH := prebuilts/clang/host/$(BUILD_OS)-x86/$(LLVM_PREBUILTS_VERSION)/bin
 LLVM_RTLIB_PATH := $(LLVM_PREBUILTS_PATH)/../lib/clang/$(LLVM_PREBUILTS_VERSION)/lib/linux/
 
 CLANG := $(LLVM_PREBUILTS_PATH)/clang$(BUILD_EXECUTABLE_SUFFIX)
@@ -78,7 +79,8 @@
   -Wno-unused-local-typedefs \
   -Wunused-but-set-parameter \
   -Wunused-but-set-variable \
-  -fdiagnostics-color
+  -fdiagnostics-color \
+  -fdebug-prefix-map=/proc/self/cwd=
 
 # Clang flags for all host rules
 CLANG_CONFIG_HOST_EXTRA_ASFLAGS :=
diff --git a/core/config.mk b/core/config.mk
index ca6dc7c..1ae2655 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -182,6 +182,19 @@
 FIND_LEAVES_EXCLUDES := $(addprefix --prune=, $(OUT_DIR) $(SCAN_EXCLUDE_DIRS) .repo .git)
 
 # ---------------------------------------------------------------
+# We run gcc/clang with PWD=/proc/self/cwd to remove the $TOP
+# from the debug output. That way two builds in two different
+# directories will create the same output.
+# /proc doesn't exist on Darwin.
+ifeq ($(HOST_OS),linux)
+RELATIVE_PWD := PWD=/proc/self/cwd
+# Remove this useless prefix from the debug output.
+COMMON_GLOBAL_CFLAGS += -fdebug-prefix-map=/proc/self/cwd=
+else
+RELATIVE_PWD :=
+endif
+
+# ---------------------------------------------------------------
 # Allow the C/C++ macros __DATE__ and __TIME__ to be set to the
 # build date and time, so that a build may be repeated.
 # Write the date and time to a file so that the command line
@@ -630,21 +643,14 @@
 endif
 
 # Flags for DEX2OAT
+first_non_empty_of_three = $(if $(1),$(1),$(if $(2),$(2),$(3)))
 DEX2OAT_TARGET_ARCH := $(TARGET_ARCH)
-ifeq ($(TARGET_CPU_VARIANT),)
-ifeq ($(TARGET_ARCH_VARIANT),)
-DEX2OAT_TARGET_CPU_VARIANT := default
-else
-DEX2OAT_TARGET_CPU_VARIANT := $(TARGET_ARCH_VARIANT)
-endif
-else
-DEX2OAT_TARGET_CPU_VARIANT := $(TARGET_CPU_VARIANT)
-endif
+DEX2OAT_TARGET_CPU_VARIANT := $(call first_non_empty_of_three,$(TARGET_CPU_VARIANT),$(TARGET_ARCH_VARIANT),default)
 DEX2OAT_TARGET_INSTRUCTION_SET_FEATURES := default
 
 ifdef TARGET_2ND_ARCH
 $(TARGET_2ND_ARCH_VAR_PREFIX)DEX2OAT_TARGET_ARCH := $(TARGET_2ND_ARCH)
-$(TARGET_2ND_ARCH_VAR_PREFIX)DEX2OAT_TARGET_CPU_VARIANT := $(TARGET_2ND_CPU_VARIANT)
+$(TARGET_2ND_ARCH_VAR_PREFIX)DEX2OAT_TARGET_CPU_VARIANT := $(call first_non_empty_of_three,$(TARGET_2ND_CPU_VARIANT),$(TARGET_2ND_ARCH_VARIANT),default)
 $(TARGET_2ND_ARCH_VAR_PREFIX)DEX2OAT_TARGET_INSTRUCTION_SET_FEATURES := default
 endif
 
diff --git a/core/definitions.mk b/core/definitions.mk
index 12dcfb4..a036a25 100644
--- a/core/definitions.mk
+++ b/core/definitions.mk
@@ -1057,7 +1057,7 @@
 define transform-cpp-to-o
 @echo "target $(PRIVATE_ARM_MODE) C++: $(PRIVATE_MODULE) <= $<"
 @mkdir -p $(dir $@)
-$(hide) $(PRIVATE_CXX) \
+$(hide) $(RELATIVE_PWD) $(PRIVATE_CXX) \
 	$(addprefix -I , $(PRIVATE_C_INCLUDES)) \
 	$(shell cat $(PRIVATE_IMPORT_INCLUDES)) \
 	$(addprefix -isystem ,\
@@ -1089,7 +1089,7 @@
 # $(1): extra flags
 define transform-c-or-s-to-o-no-deps
 @mkdir -p $(dir $@)
-$(hide) $(PRIVATE_CC) \
+$(hide) $(RELATIVE_PWD) $(PRIVATE_CC) \
 	$(addprefix -I , $(PRIVATE_C_INCLUDES)) \
 	$(shell cat $(PRIVATE_IMPORT_INCLUDES)) \
 	$(addprefix -isystem ,\
@@ -1164,7 +1164,7 @@
 define transform-host-cpp-to-o
 @echo "$($(PRIVATE_PREFIX)DISPLAY) C++: $(PRIVATE_MODULE) <= $<"
 @mkdir -p $(dir $@)
-$(hide) $(PRIVATE_CXX) \
+$(hide) $(RELATIVE_PWD) $(PRIVATE_CXX) \
 	$(addprefix -I , $(PRIVATE_C_INCLUDES)) \
 	$(shell cat $(PRIVATE_IMPORT_INCLUDES)) \
 	$(addprefix -isystem ,\
@@ -1194,7 +1194,7 @@
 # $(1): extra flags
 define transform-host-c-or-s-to-o-no-deps
 @mkdir -p $(dir $@)
-$(hide) $(PRIVATE_CC) \
+$(hide) $(RELATIVE_PWD) $(PRIVATE_CC) \
 	$(addprefix -I , $(PRIVATE_C_INCLUDES)) \
 	$(shell cat $(PRIVATE_IMPORT_INCLUDES)) \
 	$(addprefix -isystem ,\
diff --git a/core/ninja.mk b/core/ninja.mk
index 6fc508d..81298e5 100644
--- a/core/ninja.mk
+++ b/core/ninja.mk
@@ -121,7 +121,7 @@
 .INTERMEDIATE: ninja.intermediate
 ninja.intermediate: $(KATI_OUTPUTS) $(MAKEPARALLEL)
 	@echo Starting build with ninja
-	+$(hide) PATH=prebuilts/ninja/$(HOST_PREBUILT_TAG)/:$$PATH NINJA_STATUS="$(NINJA_STATUS)" $(NINJA_MAKEPARALLEL) $(KATI_NINJA_SH) -C $(TOP) $(NINJA_ARGS) $(filter-out dist,$(ANDROID_TARGETS))
+	+$(hide) PATH=prebuilts/ninja/$(HOST_PREBUILT_TAG)/:$$PATH NINJA_STATUS="$(NINJA_STATUS)" $(NINJA_MAKEPARALLEL) $(KATI_NINJA_SH) $(filter-out dist,$(ANDROID_TARGETS)) -C $(TOP) $(NINJA_ARGS)
 else
 generateonly droid $(ANDROID_TARGETS) $(EXTRA_TARGETS): $(KATI_OUTPUTS)
 	@#empty
diff --git a/envsetup.sh b/envsetup.sh
index d133c8e..cc2b08f 100644
--- a/envsetup.sh
+++ b/envsetup.sh
@@ -21,7 +21,7 @@
 - sgrep:     Greps on all local source files.
 - godir:     Go to the directory containing a file.
 
-Environemnt options:
+Environment options:
 - SANITIZE_HOST: Set to 'true' to use ASAN for all host modules. Note that
                  ASAN_OPTIONS=detect_leaks=0 will be set by default until the
                  build is leak-check clean.
@@ -920,7 +920,7 @@
 	adb root;
 	adb wait-for-device;
 
-	echo "Remounting root parition read-write...";
+	echo "Remounting root partition read-write...";
 	adb shell mount -w -o remount -t rootfs rootfs;
 	sleep 1;
 	adb wait-for-device;
diff --git a/target/board/generic_x86/BoardConfig.mk b/target/board/generic_x86/BoardConfig.mk
index 0b8e1cd..a34e4f2 100644
--- a/target/board/generic_x86/BoardConfig.mk
+++ b/target/board/generic_x86/BoardConfig.mk
@@ -45,3 +45,5 @@
 BOARD_SEPOLICY_DIRS += \
         build/target/board/generic/sepolicy \
         build/target/board/generic_x86/sepolicy
+
+USE_CLANG_PLATFORM_BUILD := true
diff --git a/tools/makeparallel/Makefile b/tools/makeparallel/Makefile
index 4e79708..4e12b10 100644
--- a/tools/makeparallel/Makefile
+++ b/tools/makeparallel/Makefile
@@ -90,3 +90,5 @@
 	@EXPECTED="-j1"    $(MAKEPARALLEL_TEST) A=-j1234
 	@EXPECTED="-j1"    $(MAKEPARALLEL_TEST) A\ -j1234=-j1234
 	@EXPECTED="-j1234" $(MAKEPARALLEL_TEST) A\ -j1234=-j1234 -j1234
+
+	@EXPECTED="-j1234 args" ARGS="args" $(MAKEPARALLEL_TEST) -j1234
diff --git a/tools/makeparallel/Makefile.test b/tools/makeparallel/Makefile.test
index 91aacf7..cf53684 100644
--- a/tools/makeparallel/Makefile.test
+++ b/tools/makeparallel/Makefile.test
@@ -3,7 +3,7 @@
 .PHONY: test
 test:
 	@+echo MAKEFLAGS=$${MAKEFLAGS};              \
-	result=$$($(MAKEPARALLEL) echo);             \
+	result=$$($(MAKEPARALLEL) echo $(ARGS));     \
 	echo result: $${result};                     \
 	if [ "$${result}" = "$(EXPECTED)" ]; then    \
 	  echo SUCCESS && echo;                      \
diff --git a/tools/makeparallel/makeparallel.cpp b/tools/makeparallel/makeparallel.cpp
index 7dd0ceb..576fe8d 100644
--- a/tools/makeparallel/makeparallel.cpp
+++ b/tools/makeparallel/makeparallel.cpp
@@ -298,8 +298,12 @@
     argc--;
   }
 
+  if (argc < 2) {
+    error(EXIT_FAILURE, 0, "expected command to run");
+  }
+
   const char* path = argv[1];
-  std::vector<char*> args(&argv[1], &argv[argc]);
+  std::vector<char*> args({argv[1]});
 
   std::vector<std::string> makeflags = ReadMakeflags();
   if (ParseMakeflags(makeflags, &in_fd, &out_fd, &parallel, &keep_going)) {
@@ -328,6 +332,8 @@
     args.push_back(strdup(jarg.c_str()));
   }
 
+  args.insert(args.end(), &argv[2], &argv[argc]);
+
   args.push_back(nullptr);
 
   pid_t pid = fork();