Add Makefile and common.mk

These are required for the Chrome OS build. This is a partial
revert of c7e849876a3c2f264b19b569c0b44287a287e839 ("Remove
external/mojo makefiles") with some tweaks so things still compile
on ToT.

Bug: 37434548
Test: emerge libmojo-456626 for a CrOS board

Change-Id: I24f38f9798c6d1a44ec7638fb0717f6c347ef46f

2 files changed, 1125 insertions, 0 deletions

diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..b554549
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,191 @@
+# Copyright 2018 The Chromium OS Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+include common.mk
+
+PC_DEPS = libchrome-$(BASE_VER)
+PC_CFLAGS := $(shell $(PKG_CONFIG) --cflags $(PC_DEPS))
+PC_LIBS := $(shell $(PKG_CONFIG) --libs $(PC_DEPS))
+
+CPPFLAGS += -Wno-unused-parameter -Wno-missing-field-initializers $(PC_CFLAGS) -I$(OUT)
+
+CXXFLAGS += -std=c++11 \
+	-Wno-sign-promo \
+	-Wno-non-virtual-dtor \
+	-Wno-ignored-qualifiers \
+	-Wno-format-nonliteral \
+	-Wno-extra \
+	-Wno-deprecated-register \
+	-Wno-char-subscripts \
+	-DOS_POSIX \
+	-DNO_TCMALLOC \
+
+LDLIBS += $(PC_LIBS)
+
+CXX_OBJECTS := \
+	base/base_paths.o \
+	base/path_service.o \
+	base/unguessable_token.o \
+	ipc/ipc_message.o \
+	ipc/ipc_message_attachment.o \
+	ipc/ipc_message_attachment_set.o \
+	ipc/ipc_message_utils.o \
+	ipc/ipc_mojo_handle_attachment.o \
+	ipc/ipc_mojo_message_helper.o \
+	ipc/ipc_mojo_param_traits.o \
+	ipc/ipc_platform_file_attachment_posix.o \
+	mojo/common/common_custom_types_struct_traits.o \
+	mojo/edk/embedder/connection_params.o \
+	mojo/edk/embedder/embedder.o \
+	mojo/edk/embedder/entrypoints.o \
+	mojo/edk/embedder/platform_channel_pair.o \
+	mojo/edk/embedder/platform_channel_pair_posix.o \
+	mojo/edk/embedder/platform_channel_utils_posix.o \
+	mojo/edk/embedder/platform_handle.o \
+	mojo/edk/embedder/platform_handle_utils_posix.o \
+	mojo/edk/embedder/platform_shared_buffer.o \
+	mojo/edk/system/awakable_list.o \
+	mojo/edk/system/broker_host.o \
+	mojo/edk/system/broker_posix.o \
+	mojo/edk/system/channel.o \
+	mojo/edk/system/channel_posix.o \
+	mojo/edk/system/configuration.o \
+	mojo/edk/system/core.o \
+	mojo/edk/system/data_pipe_consumer_dispatcher.o \
+	mojo/edk/system/data_pipe_control_message.o \
+	mojo/edk/system/data_pipe_producer_dispatcher.o \
+	mojo/edk/system/dispatcher.o \
+	mojo/edk/system/handle_table.o \
+	mojo/edk/system/mapping_table.o \
+	mojo/edk/system/message_for_transit.o \
+	mojo/edk/system/message_pipe_dispatcher.o \
+	mojo/edk/system/node_channel.o \
+	mojo/edk/system/node_controller.o \
+	mojo/edk/system/platform_handle_dispatcher.o \
+	mojo/edk/system/ports/event.o \
+	mojo/edk/system/ports/message.o \
+	mojo/edk/system/ports/message_queue.o \
+	mojo/edk/system/ports/name.o \
+	mojo/edk/system/ports/node.o \
+	mojo/edk/system/ports/port.o \
+	mojo/edk/system/ports/port_ref.o \
+	mojo/edk/system/ports_message.o \
+	mojo/edk/system/request_context.o \
+	mojo/edk/system/shared_buffer_dispatcher.o \
+	mojo/edk/system/wait_set_dispatcher.o \
+	mojo/edk/system/waiter.o \
+	mojo/edk/system/watcher.o \
+	mojo/edk/system/watcher_set.o \
+	mojo/public/c/system/thunks.o \
+	mojo/public/cpp/bindings/lib/array_internal.o \
+	mojo/public/cpp/bindings/lib/associated_group.o \
+	mojo/public/cpp/bindings/lib/associated_group_controller.o \
+	mojo/public/cpp/bindings/lib/binding_state.o \
+	mojo/public/cpp/bindings/lib/connector.o \
+	mojo/public/cpp/bindings/lib/control_message_handler.o \
+	mojo/public/cpp/bindings/lib/control_message_proxy.o \
+	mojo/public/cpp/bindings/lib/filter_chain.o \
+	mojo/public/cpp/bindings/lib/fixed_buffer.o \
+	mojo/public/cpp/bindings/lib/interface_endpoint_client.o \
+	mojo/public/cpp/bindings/lib/message.o \
+	mojo/public/cpp/bindings/lib/message_buffer.o \
+	mojo/public/cpp/bindings/lib/message_builder.o \
+	mojo/public/cpp/bindings/lib/message_header_validator.o \
+	mojo/public/cpp/bindings/lib/multiplex_router.o \
+	mojo/public/cpp/bindings/lib/native_struct.o \
+	mojo/public/cpp/bindings/lib/native_struct_data.o \
+	mojo/public/cpp/bindings/lib/native_struct_serialization.o \
+	mojo/public/cpp/bindings/lib/pipe_control_message_handler.o \
+	mojo/public/cpp/bindings/lib/pipe_control_message_proxy.o \
+	mojo/public/cpp/bindings/lib/scoped_interface_endpoint_handle.o \
+	mojo/public/cpp/bindings/lib/serialization_context.o \
+	mojo/public/cpp/bindings/lib/sync_call_restrictions.o \
+	mojo/public/cpp/bindings/lib/sync_handle_registry.o \
+	mojo/public/cpp/bindings/lib/sync_handle_watcher.o \
+	mojo/public/cpp/bindings/lib/validation_context.o \
+	mojo/public/cpp/bindings/lib/validation_errors.o \
+	mojo/public/cpp/bindings/lib/validation_util.o \
+	mojo/public/cpp/system/platform_handle.o \
+	mojo/public/cpp/system/watcher.o
+
+MOJOM_FILES := ipc/ipc.mojom \
+	mojo/common/file.mojom \
+	mojo/common/string16.mojom \
+	mojo/common/text_direction.mojom \
+	mojo/common/time.mojom \
+	mojo/common/unguessable_token.mojom \
+	mojo/common/version.mojom \
+	mojo/public/interfaces/bindings/pipe_control_messages.mojom \
+	mojo/public/interfaces/bindings/interface_control_messages.mojom \
+
+MOJOM_BINDINGS_GENERATOR := \
+	$(S)/mojo/public/tools/bindings/mojom_bindings_generator.py
+
+GEN_TEMPLATES_DIR := $(S)/templates
+
+gen_templates:
+	@echo generate_mojo_templates: $(GEN_TEMPLATES_DIR)
+	@rm -rf $(GEN_TEMPLATES_DIR)
+	@mkdir -p $(GEN_TEMPLATES_DIR)
+	@python $(MOJOM_BINDINGS_GENERATOR) --use_bundled_pylibs precompile \
+		-o $(GEN_TEMPLATES_DIR)
+
+templates: gen_templates
+	cd $(S) && \
+		python $(abspath $(MOJOM_BINDINGS_GENERATOR)) \
+		--use_bundled_pylibs generate \
+		$(MOJOM_FILES) \
+		-o $(abspath $(S)) \
+		--bytecode_path $(abspath $(GEN_TEMPLATES_DIR)) \
+		-g c++
+	cd $(S) && \
+		python $(abspath $(MOJOM_BINDINGS_GENERATOR)) \
+		--use_bundled_pylibs generate \
+		$(MOJOM_FILES) \
+		-o $(abspath $(S)) \
+		--bytecode_path $(abspath $(GEN_TEMPLATES_DIR)) \
+		--generate_non_variant_code \
+		-g c++
+
+GENERATED_OBJECTS := $(patsubst %.mojom,%.mojom.o,$(MOJOM_FILES))
+GENERATED_SHARED_OBJECTS := $(patsubst %.mojom,%.mojom-shared.o,$(MOJOM_FILES))
+
+$(eval $(call add_object_rules,$(GENERATED_OBJECTS),CXX,cc,CXXFLAGS,$(SRC)/))
+$(eval $(call add_object_rules,$(GENERATED_SHARED_OBJECTS),CXX,cc,CXXFLAGS,$(SRC)/))
+# Note: I don't know why we need the line below (it's in commmon.mk), but without it,
+# .o files from CXX_OBJECTS won't be built.
+$(eval $(call add_object_rules,$(CXX_OBJECTS),CXX,cc,CXXFLAGS,$(SRC)/))
+
+LIB ?= lib
+LIB_PIE_NAME = libmojo-$(BASE_VER).pie.a
+LIB_PIC_NAME = libmojo-$(BASE_VER).pic.a
+
+CXX_STATIC_LIBRARY($(LIB_PIE_NAME)): $(GENERATED_SHARED_OBJECTS) $(GENERATED_OBJECTS) $(CXX_OBJECTS)
+CXX_STATIC_LIBRARY($(LIB_PIC_NAME)): $(GENERATED_SHARED_OBJECTS) $(GENERATED_OBJECTS) $(CXX_OBJECTS)
+
+all: CXX_STATIC_LIBRARY($(LIB_PIE_NAME)) CXX_STATIC_LIBRARY($(LIB_PIC_NAME))
+
+clean: CLEAN($(LIB_PIE_NAME)) CLEAN($(LIB_PIC_NAME))
+
+install_lib: all
+	install -D -m 755 $(OUT)/$(LIB_PIE_NAME) $(DESTDIR)/usr/$(LIB)/$(LIB_PIE_NAME)
+	install -D -m 755 $(OUT)/$(LIB_PIC_NAME) $(DESTDIR)/usr/$(LIB)/$(LIB_PIC_NAME)
+	sed -e "s:@LIB@:$(LIB):g" -e "s:@BSLOT@:$(BASE_VER):g" $(S)/libmojo.pc.in > $(S)/libmojo-$(BASE_VER).pc
+
+install_tool:
+	install -d $(DESTDIR)/usr/src/libmojo-$(BASE_VER)/mojo/
+	cp -r --preserve=mode $(SRC)/third_party $(DESTDIR)/usr/src/libmojo-$(BASE_VER)/
+	cp -r --preserve=mode $(SRC)/mojo/public/tools/bindings/* \
+		$(DESTDIR)/usr/src/libmojo-$(BASE_VER)/mojo/
+	cp --preserve=mode $(SRC)/build/gn_helpers.py \
+		$(DESTDIR)/usr/src/libmojo-$(BASE_VER)/mojo/
+	cp -r --preserve=mode $(SRC)/build/android/gyp/util/ \
+		$(DESTDIR)/usr/src/libmojo-$(BASE_VER)/mojo/
+	cp -r --preserve=mode $(SRC)/build/android/pylib \
+		$(DESTDIR)/usr/src/libmojo-$(BASE_VER)/mojo/
+	cp -r --preserve=mode $(SRC)/third_party/catapult/devil/devil \
+		$(DESTDIR)/usr/src/libmojo-$(BASE_VER)/mojo/
+
+install: install_lib install_tool
+
diff --git a/common.mk b/common.mk
new file mode 100644
index 0000000..aed7d3e
--- /dev/null
+++ b/common.mk
@@ -0,0 +1,934 @@
+# Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+#
+# If this file is part of another source distribution, it's license may be
+# stored in LICENSE.makefile or LICENSE.common.mk.
+#
+# NOTE NOTE NOTE
+#  The authoritative common.mk is located in:
+#    https://chromium.googlesource.com/chromiumos/platform2/+/master/common-mk
+#  Please make all changes there, then copy into place in other repos.
+# NOTE NOTE NOTE
+#
+# This file provides a common architecture for building C/C++ source trees.
+# It uses recursive makefile inclusion to create a single make process which
+# can be built in the source tree or with the build artifacts placed elsewhere.
+#
+# It is fully parallelizable for all targets, including static archives.
+#
+# To use:
+# 1. Place common.mk in your top source level
+# 2. In your top-level Makefile, place "include common.mk" at the top
+# 3. In all subdirectories, create a 'module.mk' file that starts with:
+#      include common.mk
+#    And then contains the remainder of your targets.
+# 4. All build targets should look like:
+#    relative/path/target: relative/path/obj.o
+#
+# See existing makefiles for rule examples.
+#
+# Exported macros:
+#   - cc_binary, cxx_binary provide standard compilation steps for binaries
+#   - cxx_library, cc_library provide standard compilation steps for
+#     shared objects.
+#   All of the above optionally take an argument for extra flags.
+#   - update_archive creates/updates a given .a target
+#
+# Instead of using the build macros, most users can just use wrapped targets:
+#   - CXX_BINARY, CC_BINARY, CC_STATIC_BINARY, CXX_STATIC_BINARY
+#   - CXX_LIBRARY, CC_LIBRARY, CC_STATIC_LIBRARY, CXX_STATIC_LIBRARY
+#   - E.g., CXX_BINARY(mahbinary): foo.o
+#   - object.depends targets may be used when a prerequisite is required for an
+#     object file. Because object files result in multiple build artifacts to
+#     handle PIC and PIE weirdness. E.g.
+#       foo.o.depends: generated/dbus.h
+#   - TEST(binary) or TEST(CXX_BINARY(binary)) may be used as a prerequisite
+#     for the tests target to trigger an automated test run.
+#   - CLEAN(file_or_dir) dependency can be added to 'clean'.
+#
+# If source code is being generated, rules will need to be registered for
+# compiling the objects.  This can be done by adding one of the following
+# to the Makefile:
+#   - For C source files
+#   $(eval $(call add_object_rules,sub/dir/gen_a.o sub/dir/b.o,CC,c,CFLAGS))
+#   - For C++ source files
+#   $(eval $(call add_object_rules,sub/dir/gen_a.o sub/dir/b.o,CXX,cc,CXXFLAGS))
+#
+# Exported targets meant to have prerequisites added to:
+#  - all - Your desired targets should be given
+#  - tests - Any TEST(test_binary) targets should be given
+#  - FORCE - force the given target to run regardless of changes
+#            In most cases, using .PHONY is preferred.
+#
+# Possible command line variables:
+#   - COLOR=[0|1] to set ANSI color output (default: 1)
+#   - VERBOSE=[0|1] to hide/show commands (default: 0)
+#   - MODE=[opt|dbg|profiling] (default: opt)
+#          opt - Enable optimizations for release builds
+#          dbg - Turn down optimization for debugging
+#          profiling - Turn off optimization and turn on profiling/coverage
+#                      support.
+#   - ARCH=[x86|arm|supported qemu name] (default: from portage or uname -m)
+#   - SPLITDEBUG=[0|1] splits debug info in target.debug (default: 0)
+#        If NOSTRIP=1, SPLITDEBUG will never strip the final emitted objects.
+#   - NOSTRIP=[0|1] determines if binaries are stripped. (default: 1)
+#        NOSTRIP=0 and MODE=opt will also drop -g from the CFLAGS.
+#   - VALGRIND=[0|1] runs tests under valgrind (default: 0)
+#   - OUT=/path/to/builddir puts all output in given path (default: $PWD)
+#   - VALGRIND_ARGS="" supplies extra memcheck arguments
+#
+# Per-target(-ish) variable:
+#   - NEEDS_ROOT=[0|1] allows a TEST() target to run with root.
+#     Default is 0 unless it is running under QEmu.
+#   - NEEDS_MOUNTS=[0|1] allows a TEST() target running on QEmu to get
+#     setup mounts in the $(SYSROOT)
+#
+# Caveats:
+# - Directories or files with spaces in them DO NOT get along with GNU Make.
+#   If you need them, all uses of dir/notdir/etc will need to have magic
+#   wrappers.  Proceed at risk to your own sanity.
+# - External CXXFLAGS and CFLAGS should be passed via the environment since
+#   this file does not use 'override' to control them.
+# - Our version of GNU Make doesn't seem to support the 'private' variable
+#   annotation, so you can't tag a variable private on a wrapping target.
+
+# Behavior configuration variables
+SPLITDEBUG ?= 0
+NOSTRIP ?= 1
+VALGRIND ?= 0
+COLOR ?= 1
+VERBOSE ?= 0
+MODE ?= opt
+CXXEXCEPTIONS ?= 0
+ARCH ?= $(shell uname -m)
+
+# Put objects in a separate tree based on makefile locations
+# This means you can build a tree without touching it:
+#   make -C $SRCDIR  # will create ./build-$(MODE)
+# Or
+#   make -C $SRCDIR OUT=$PWD
+# This variable is extended on subdir calls and doesn't need to be re-called.
+OUT ?= $(PWD)/
+
+# Make OUT now so we can use realpath.
+$(shell mkdir -p "$(OUT)")
+
+# TODO(wad) Relative paths are resolved against SRC and not the calling dir.
+# Ensure a command-line supplied OUT has a slash
+override OUT := $(realpath $(OUT))/
+
+# SRC is not meant to be set by the end user, but during make call relocation.
+# $(PWD) != $(CURDIR) all the time.
+export SRC ?= $(CURDIR)
+
+# Re-start in the $(OUT) directory if we're not there.
+# We may be invoked using -C or bare and we need to ensure behavior
+# is consistent so we check both PWD vs OUT and PWD vs CURDIR.
+override RELOCATE_BUILD := 0
+ifneq (${PWD}/,${OUT})
+override RELOCATE_BUILD := 1
+endif
+# Make sure we're running with no builtin targets. They cause
+# leakage and mayhem!
+ifneq (${PWD},${CURDIR})
+override RELOCATE_BUILD := 1
+# If we're run from the build dir, don't let it get cleaned up later.
+ifeq (${PWD}/,${OUT})
+$(shell touch "$(PWD)/.dont_delete_on_clean")
+endif
+endif  # ifneq (${PWD},${CURDIR}
+
+# "Relocate" if we need to restart without implicit rules.
+ifeq ($(subst r,,$(MAKEFLAGS)),$(MAKEFLAGS))
+override RELOCATE_BUILD := 1
+endif
+
+ifeq (${RELOCATE_BUILD},1)
+# By default, silence build output. Reused below as well.
+QUIET = @
+ifeq ($(VERBOSE),1)
+  QUIET=
+endif
+
+# This target will override all targets, including prerequisites. To avoid
+# calling $(MAKE) once per prereq on the given CMDGOAL, we guard it with a local
+# variable.
+RUN_ONCE := 0
+MAKECMDGOALS ?= all
+# Keep the rules split as newer make does not allow them to be declared
+# on the same line.  But the way :: rules work, the _all here will also
+# invoke the %:: rule while retaining "_all" as the default.
+_all::
+%::
+	$(if $(filter 0,$(RUN_ONCE)), \
+	  cd "$(OUT)" && \
+	  $(MAKE) -r -I "$(SRC)" -f "$(CURDIR)/Makefile" \
+	    SRC="$(CURDIR)" OUT="$(OUT)" $(foreach g,$(MAKECMDGOALS),"$(g)"),)
+	$(eval RUN_ONCE := 1)
+pass-to-subcall := 1
+endif
+
+ifeq ($(pass-to-subcall),)
+
+# Only call MODULE if we're in a submodule
+MODULES_LIST := $(filter-out Makefile %.d,$(MAKEFILE_LIST))
+ifeq ($(words $(filter-out Makefile common.mk %.d $(SRC)/Makefile \
+                           $(SRC)/common.mk,$(MAKEFILE_LIST))),0)
+
+# All the top-level defines outside of module.mk.
+
+#
+# Helper macros
+#
+
+# Create the directory if it doesn't yet exist.
+define auto_mkdir
+  $(if $(wildcard $(dir $1)),$2,$(QUIET)mkdir -p "$(dir $1)")
+endef
+
+# Creates the actual archive with an index.
+# The target $@ must end with .pic.a or .pie.a.
+define update_archive
+  $(call auto_mkdir,$(TARGET_OR_MEMBER))
+  $(QUIET)# Create the archive in one step to avoid parallel use accessing it
+  $(QUIET)# before all the symbols are present.
+  @$(ECHO) "AR		$(subst \
+$(SRC)/,,$(^:.o=$(suffix $(basename $(TARGET_OR_MEMBER))).o)) \
+-> $(subst $(SRC)/,,$(TARGET_OR_MEMBER))"
+  $(QUIET)$(AR) rcs $(TARGET_OR_MEMBER) \
+          $(subst $(SRC)/,,$(^:.o=$(suffix $(basename $(TARGET_OR_MEMBER))).o))
+endef
+
+# Default compile from objects using pre-requisites but filters out
+# subdirs and .d files.
+define cc_binary
+  $(call COMPILE_BINARY_implementation,CC,$(CFLAGS) $(1),$(EXTRA_FLAGS))
+endef
+
+define cxx_binary
+  $(call COMPILE_BINARY_implementation,CXX,$(CXXFLAGS) $(1),$(EXTRA_FLAGS))
+endef
+
+# Default compile from objects using pre-requisites but filters out
+# subdirs and .d files.
+define cc_library
+  $(call COMPILE_LIBRARY_implementation,CC,$(CFLAGS) $(1),$(EXTRA_FLAGS))
+endef
+define cxx_library
+  $(call COMPILE_LIBRARY_implementation,CXX,$(CXXFLAGS) $(1),$(EXTRA_FLAGS))
+endef
+
+# Deletes files silently if they exist. Meant for use in any local
+# clean targets.
+define silent_rm
+  $(if $(wildcard $(1)),
+  $(QUIET)($(ECHO) -n '$(COLOR_RED)CLEANFILE$(COLOR_RESET)		' && \
+    $(ECHO) '$(subst $(OUT)/,,$(wildcard $(1)))' && \
+    $(RM) $(1) 2>/dev/null) || true,)
+endef
+define silent_rmdir
+  $(if $(wildcard $(1)),
+    $(if $(wildcard $(1)/*),
+  $(QUIET)# $(1) not empty [$(wildcard $(1)/*)]. Not deleting.,
+  $(QUIET)($(ECHO) -n '$(COLOR_RED)CLEANDIR$(COLOR_RESET)		' && \
+    $(ECHO) '$(subst $(OUT)/,,$(wildcard $(1)))' && \
+    $(RMDIR) $(1) 2>/dev/null) || true),)
+endef
+
+#
+# Default variable values
+#
+
+# Only override toolchain vars if they are from make.
+CROSS_COMPILE ?=
+define override_var
+ifneq ($(filter undefined default,$(origin $1)),)
+$1 = $(CROSS_COMPILE)$2
+endif
+endef
+$(eval $(call override_var,AR,ar))
+$(eval $(call override_var,CC,gcc))
+$(eval $(call override_var,CXX,g++))
+$(eval $(call override_var,OBJCOPY,objcopy))
+$(eval $(call override_var,PKG_CONFIG,pkg-config))
+$(eval $(call override_var,RANLIB,ranlib))
+$(eval $(call override_var,STRIP,strip))
+
+RMDIR ?= rmdir
+ECHO = /bin/echo -e
+
+ifeq ($(lastword $(subst /, ,$(CC))),clang)
+CDRIVER = clang
+else
+CDRIVER = gcc
+endif
+
+ifeq ($(lastword $(subst /, ,$(CXX))),clang++)
+CXXDRIVER = clang
+else
+CXXDRIVER = gcc
+endif
+
+# Internal macro to support check_XXX macros below.
+# Usage: $(call check_compile, [code], [compiler], [code_type], [c_flags],
+#               [extra_c_flags], [library_flags], [success_ret], [fail_ret])
+# Return: [success_ret] if compile succeeded, otherwise [fail_ret]
+check_compile = $(shell printf '%b\n' $(1) | \
+  $($(2)) $($(4)) -x $(3) $(LDFLAGS) $(5) - $(6) -o /dev/null > /dev/null 2>&1 \
+  && echo "$(7)" || echo "$(8)")
+
+# Helper macro to check whether a test program will compile with the specified
+# compiler flags.
+# Usage: $(call check_compile_cc, [code], [flags], [alternate_flags])
+# Return: [flags] if compile succeeded, otherwise [alternate_flags]
+check_compile_cc = $(call check_compile,$(1),CC,c,CFLAGS,$(2),,$(2),$(3))
+check_compile_cxx = $(call check_compile,$(1),CXX,c++,CXXFLAGS,$(2),,$(2),$(3))
+
+# Helper macro to check whether a test program will compile with the specified
+# libraries.
+# Usage: $(call check_compile_cc, [code], [library_flags], [alternate_flags])
+# Return: [library_flags] if compile succeeded, otherwise [alternate_flags]
+check_libs_cc = $(call check_compile,$(1),CC,c,CFLAGS,,$(2),$(2),$(3))
+check_libs_cxx = $(call check_compile,$(1),CXX,c++,CXXFLAGS,,$(2),$(2),$(3))
+
+# Helper macro to check whether the compiler accepts the specified flags.
+# Usage: $(call check_compile_cc, [flags], [alternate_flags])
+# Return: [flags] if compile succeeded, otherwise [alternate_flags]
+check_cc = $(call check_compile_cc,'int main() { return 0; }',$(1),$(2))
+check_cxx = $(call check_compile_cxx,'int main() { return 0; }',$(1),$(2))
+
+# Choose the stack protector flags based on whats supported by the compiler.
+SSP_CFLAGS := $(call check_cc,-fstack-protector-strong)
+ifeq ($(SSP_CFLAGS),)
+ SSP_CFLAGS := $(call check_cc,-fstack-protector-all)
+endif
+
+# To update these from an including Makefile:
+#  CXXFLAGS += -mahflag  # Append to the list
+#  CXXFLAGS := -mahflag $(CXXFLAGS) # Prepend to the list
+#  CXXFLAGS := $(filter-out badflag,$(CXXFLAGS)) # Filter out a value
+# The same goes for CFLAGS.
+COMMON_CFLAGS-gcc := -fvisibility=internal -ggdb3 -Wa,--noexecstack
+COMMON_CFLAGS-clang := -fvisibility=hidden -ggdb
+COMMON_CFLAGS := -Wall -Werror -fno-strict-aliasing $(SSP_CFLAGS) -O1 -Wformat=2
+CXXFLAGS += $(COMMON_CFLAGS) $(COMMON_CFLAGS-$(CXXDRIVER))
+CFLAGS += $(COMMON_CFLAGS) $(COMMON_CFLAGS-$(CDRIVER))
+CPPFLAGS += -D_FORTIFY_SOURCE=2
+
+# Enable large file support.
+CPPFLAGS += -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE
+
+# Disable exceptions based on the CXXEXCEPTIONS setting.
+ifeq ($(CXXEXCEPTIONS),0)
+  CXXFLAGS := $(CXXFLAGS) -fno-exceptions -fno-unwind-tables \
+    -fno-asynchronous-unwind-tables
+endif
+
+ifeq ($(MODE),opt)
+  # Up the optimizations.
+  CFLAGS := $(filter-out -O1,$(CFLAGS)) -O2
+  CXXFLAGS := $(filter-out -O1,$(CXXFLAGS)) -O2
+  # Only drop -g* if symbols aren't desired.
+  ifeq ($(NOSTRIP),0)
+    # TODO: do we want -fomit-frame-pointer on x86?
+    CFLAGS := $(filter-out -ggdb3,$(CFLAGS))
+    CXXFLAGS := $(filter-out -ggdb3,$(CXXFLAGS))
+  endif
+endif
+
+ifeq ($(MODE),profiling)
+  CFLAGS := $(CFLAGS) -O0 -g  --coverage
+  CXXFLAGS := $(CXXFLAGS) -O0 -g  --coverage
+  LDFLAGS := $(LDFLAGS) --coverage
+endif
+
+LDFLAGS := $(LDFLAGS) -Wl,-z,relro -Wl,-z,noexecstack -Wl,-z,now
+
+# Fancy helpers for color if a prompt is defined
+ifeq ($(COLOR),1)
+COLOR_RESET = \x1b[0m
+COLOR_GREEN = \x1b[32;01m
+COLOR_RED = \x1b[31;01m
+COLOR_YELLOW = \x1b[33;01m
+endif
+
+# By default, silence build output.
+QUIET = @
+ifeq ($(VERBOSE),1)
+  QUIET=
+endif
+
+#
+# Implementation macros for compile helpers above
+#
+
+# Useful for dealing with pie-broken toolchains.
+# Call make with PIE=0 to disable default PIE use.
+OBJ_PIE_FLAG = -fPIE
+COMPILE_PIE_FLAG = -pie
+ifeq ($(PIE),0)
+  OBJ_PIE_FLAG =
+  COMPILE_PIE_FLAG =
+endif
+
+# Favor member targets first for CXX_BINARY(%) magic.
+# And strip out nested members if possible.
+LP := (
+RP := )
+TARGET_OR_MEMBER = $(lastword $(subst $(LP), ,$(subst $(RP),,$(or $%,$@))))
+
+# Default compile from objects using pre-requisites but filters out
+# all non-.o files.
+define COMPILE_BINARY_implementation
+  @$(ECHO) "LD$(1)		$(subst $(PWD)/,,$(TARGET_OR_MEMBER))"
+  $(call auto_mkdir,$(TARGET_OR_MEMBER))
+  $(QUIET)$($(1)) $(COMPILE_PIE_FLAGS) -o $(TARGET_OR_MEMBER) \
+    $(2) $(LDFLAGS) \
+    $(filter %.o %.a,$(^:.o=.pie.o)) \
+    $(foreach so,$(filter %.so,$^),-L$(dir $(so)) \
+                            -l$(patsubst lib%,%,$(basename $(notdir $(so))))) \
+    $(LDLIBS)
+  $(call conditional_strip)
+  @$(ECHO) -n "BIN		"
+  @$(ECHO) "$(COLOR_GREEN)$(subst $(PWD)/,,$(TARGET_OR_MEMBER))$(COLOR_RESET)"
+  @$(ECHO) "	$(COLOR_YELLOW)-----$(COLOR_RESET)"
+endef
+
+# TODO: add version support extracted from PV environment variable
+#ifeq ($(PV),9999)
+#$(warning PV=$(PV). If shared object versions matter, please force PV=.)
+#endif
+# Then add -Wl,-soname,$@.$(PV) ?
+
+# Default compile from objects using pre-requisites but filters out
+# all non-.o values. (Remember to add -L$(OUT) -llib)
+COMMA := ,
+define COMPILE_LIBRARY_implementation
+  @$(ECHO) "SHARED$(1)	$(subst $(PWD)/,,$(TARGET_OR_MEMBER))"
+  $(call auto_mkdir,$(TARGET_OR_MEMBER))
+  $(QUIET)$($(1)) -shared -Wl,-E -o $(TARGET_OR_MEMBER) \
+    $(2) $(LDFLAGS) \
+    $(if $(filter %.a,$^),-Wl$(COMMA)--whole-archive,) \
+    $(filter %.o ,$(^:.o=.pic.o)) \
+    $(foreach a,$(filter %.a,$^),-L$(dir $(a)) \
+                            -l$(patsubst lib%,%,$(basename $(notdir $(a))))) \
+    $(foreach so,$(filter %.so,$^),-L$(dir $(so)) \
+                            -l$(patsubst lib%,%,$(basename $(notdir $(so))))) \
+    $(LDLIBS)
+  $(call conditional_strip)
+  @$(ECHO) -n "LIB		$(COLOR_GREEN)"
+  @$(ECHO) "$(subst $(PWD)/,,$(TARGET_OR_MEMBER))$(COLOR_RESET)"
+  @$(ECHO) "	$(COLOR_YELLOW)-----$(COLOR_RESET)"
+endef
+
+define conditional_strip
+  $(if $(filter 0,$(NOSTRIP)),$(call strip_artifact))
+endef
+
+define strip_artifact
+  @$(ECHO) "STRIP		$(subst $(OUT)/,,$(TARGET_OR_MEMBER))"
+  $(if $(filter 1,$(SPLITDEBUG)), @$(ECHO) -n "DEBUG	"; \
+    $(ECHO) "$(COLOR_YELLOW)\
+$(subst $(OUT)/,,$(TARGET_OR_MEMBER)).debug$(COLOR_RESET)")
+  $(if $(filter 1,$(SPLITDEBUG)), \
+    $(QUIET)$(OBJCOPY) --only-keep-debug "$(TARGET_OR_MEMBER)" \
+      "$(TARGET_OR_MEMBER).debug")
+  $(if $(filter-out dbg,$(MODE)),$(QUIET)$(STRIP) --strip-unneeded \
+    "$(TARGET_OR_MEMBER)",)
+endef
+
+#
+# Global pattern rules
+#
+
+# Below, the archive member syntax is abused to create fancier
+# syntactic sugar for recipe authors that avoids needed to know
+# subcall options.  The downside is that make attempts to look
+# into the phony archives for timestamps. This will cause the final
+# target to be rebuilt/linked on _every_ call to make even when nothing
+# has changed.  Until a better way presents itself, we have helpers that
+# do the stat check on make's behalf.  Dodgy but simple.
+define old_or_no_timestamp
+  $(if $(realpath $%),,$(1))
+  $(if $(shell find $^ -cnewer "$%" 2>/dev/null),$(1))
+endef
+
+define check_deps
+  $(if $(filter 0,$(words $^)),\
+    $(error Missing dependencies or declaration of $@($%)),)
+endef
+
+# Build a cxx target magically
+CXX_BINARY(%):
+	$(call check_deps)
+	$(call old_or_no_timestamp,$(call cxx_binary))
+clean: CLEAN(CXX_BINARY*)
+
+CC_BINARY(%):
+	$(call check_deps)
+	$(call old_or_no_timestamp,$(call cc_binary))
+clean: CLEAN(CC_BINARY*)
+
+CXX_STATIC_BINARY(%):
+	$(call check_deps)
+	$(call old_or_no_timestamp,$(call cxx_binary,-static))
+clean: CLEAN(CXX_STATIC_BINARY*)
+
+CC_STATIC_BINARY(%):
+	$(call check_deps)
+	$(call old_or_no_timestamp,$(call cc_binary,-static))
+clean: CLEAN(CC_STATIC_BINARY*)
+
+CXX_LIBRARY(%):
+	$(call check_deps)
+	$(call old_or_no_timestamp,$(call cxx_library))
+clean: CLEAN(CXX_LIBRARY*)
+
+CXX_LIBARY(%):
+	$(error Typo alert! LIBARY != LIBRARY)
+
+CC_LIBRARY(%):
+	$(call check_deps)
+	$(call old_or_no_timestamp,$(call cc_library))
+clean: CLEAN(CC_LIBRARY*)
+
+CC_LIBARY(%):
+	$(error Typo alert! LIBARY != LIBRARY)
+
+CXX_STATIC_LIBRARY(%):
+	$(call check_deps)
+	$(call old_or_no_timestamp,$(call update_archive))
+clean: CLEAN(CXX_STATIC_LIBRARY*)
+
+CXX_STATIC_LIBARY(%):
+	$(error Typo alert! LIBARY != LIBRARY)
+
+CC_STATIC_LIBRARY(%):
+	$(call check_deps)
+	$(call old_or_no_timestamp,$(call update_archive))
+clean: CLEAN(CC_STATIC_LIBRARY*)
+
+CC_STATIC_LIBARY(%):
+	$(error Typo alert! LIBARY != LIBRARY)
+
+
+TEST(%): % qemu_chroot_install
+	$(call TEST_implementation)
+.PHONY: TEST
+
+# multiple targets with a wildcard need to share an directory.
+# Don't use this directly it just makes sure the directory is removed _after_
+# the files are.
+CLEANFILE(%):
+	$(call silent_rm,$(TARGET_OR_MEMBER))
+.PHONY: CLEANFILE
+
+CLEAN(%): CLEANFILE(%)
+	$(QUIET)# CLEAN($%) meta-target called
+	$(if $(filter-out $(PWD)/,$(dir $(abspath $(TARGET_OR_MEMBER)))), \
+	  $(call silent_rmdir,$(dir $(abspath $(TARGET_OR_MEMBER)))),\
+	  $(QUIET)# Not deleting $(dir $(abspath $(TARGET_OR_MEMBER))) yet.)
+.PHONY: CLEAN
+
+#
+# Top-level objects and pattern rules
+#
+
+# All objects for .c files at the top level
+C_OBJECTS = $(patsubst $(SRC)/%.c,%.o,$(wildcard $(SRC)/*.c))
+
+
+# All objects for .cxx files at the top level
+CXX_OBJECTS = $(patsubst $(SRC)/%.cc,%.o,$(wildcard $(SRC)/*.cc))
+
+# Note, the catch-all pattern rules don't work in subdirectories because
+# we're building from the $(OUT) directory. At the top-level (here) they will
+# work, but we go ahead and match using the module form.  Then we can place a
+# generic pattern rule to capture leakage from the main Makefile. (Later in the
+# file.)
+#
+# The reason target specific pattern rules work well for modules,
+# MODULE_C_OBJECTS, is because it scopes the behavior to the given target which
+# ensures we get a relative directory offset from $(OUT) which otherwise would
+# not match without further magic on a per-subdirectory basis.
+
+# Creates object file rules. Call with eval.
+# $(1) list of .o files
+# $(2) source type (CC or CXX)
+# $(3) source suffix (cc or c)
+# $(4) compiler flag name (CFLAGS or CXXFLAGS)
+# $(5) source dir: _only_ if $(SRC). Leave blank for obj tree.
+define add_object_rules
+$(patsubst %.o,%.pie.o,$(1)): %.pie.o: $(5)%.$(3) %.o.depends
+	$$(call auto_mkdir,$$@)
+	$$(call OBJECT_PATTERN_implementation,$(2),\
+          $$(basename $$@),$$($(4)) $$(CPPFLAGS) $$(OBJ_PIE_FLAG))
+
+$(patsubst %.o,%.pic.o,$(1)): %.pic.o: $(5)%.$(3) %.o.depends
+	$$(call auto_mkdir,$$@)
+	$$(call OBJECT_PATTERN_implementation,$(2),\
+          $$(basename $$@),$$($(4)) $$(CPPFLAGS) -fPIC)
+
+# Placeholder for depends
+$(patsubst %.o,%.o.depends,$(1)):
+	$$(call auto_mkdir,$$@)
+	$$(QUIET)touch "$$@"
+
+$(1): %.o: %.pic.o %.pie.o
+	$$(call auto_mkdir,$$@)
+	$$(QUIET)touch "$$@"
+endef
+
+define OBJECT_PATTERN_implementation
+  @$(ECHO) "$(1)		$(subst $(SRC)/,,$<) -> $(2).o"
+  $(call auto_mkdir,$@)
+  $(QUIET)$($(1)) -c -MD -MF $(2).d $(3) -o $(2).o $<
+  $(QUIET)# Wrap all the deps in $$(wildcard) so a missing header
+  $(QUIET)# won't cause weirdness.  First we remove newlines and \,
+  $(QUIET)# then wrap it.
+  $(QUIET)sed -i -e :j -e '$$!N;s|\\\s*\n| |;tj' \
+    -e 's|^\(.*\s*:\s*\)\(.*\)$$|\1 $$\(wildcard \2\)|' $(2).d
+endef
+
+# Now actually register handlers for C(XX)_OBJECTS.
+$(eval $(call add_object_rules,$(C_OBJECTS),CC,c,CFLAGS,$(SRC)/))
+$(eval $(call add_object_rules,$(CXX_OBJECTS),CXX,cc,CXXFLAGS,$(SRC)/))
+
+# Disable default pattern rules to help avoid leakage.
+# These may already be handled by '-r', but let's keep it to be safe.
+%: %.o ;
+%.a: %.o ;
+%.o: %.c ;
+%.o: %.cc ;
+
+# NOTE: A specific rule for archive objects is avoided because parallel
+#       update of the archive causes build flakiness.
+# Instead, just make the objects the prerequisites and use update_archive
+# To use the foo.a(obj.o) functionality, targets would need to specify the
+# explicit object they expect on the prerequisite line.
+
+#
+# Architecture detection and QEMU wrapping
+#
+
+HOST_ARCH ?= $(shell uname -m)
+override ARCH := $(strip $(ARCH))
+override HOST_ARCH := $(strip $(HOST_ARCH))
+# emake will supply "x86" or "arm" for ARCH, but
+# if uname -m runs and you get x86_64, then this subst
+# will break.
+ifeq ($(subst x86,i386,$(ARCH)),i386)
+  QEMU_ARCH := $(subst x86,i386,$(ARCH))  # x86 -> i386
+else ifeq ($(subst amd64,x86_64,$(ARCH)),x86_64)
+  QEMU_ARCH := $(subst amd64,x86_64,$(ARCH))  # amd64 -> x86_64
+else
+  QEMU_ARCH = $(ARCH)
+endif
+override QEMU_ARCH := $(strip $(QEMU_ARCH))
+
+# If we're cross-compiling, try to use qemu for running the tests.
+ifneq ($(QEMU_ARCH),$(HOST_ARCH))
+  ifeq ($(SYSROOT),)
+    $(info SYSROOT not defined. qemu-based testing disabled)
+  else
+    # A SYSROOT is assumed for QEmu use.
+    USE_QEMU ?= 1
+
+    # Allow 64-bit hosts to run 32-bit without qemu.
+    ifeq ($(HOST_ARCH),x86_64)
+      ifeq ($(QEMU_ARCH),i386)
+        USE_QEMU = 0
+      endif
+    endif
+  endif
+else
+  USE_QEMU ?= 0
+endif
+
+# Normally we don't need to run as root or do bind mounts, so only
+# enable it by default when we're using QEMU.
+NEEDS_ROOT ?= $(USE_QEMU)
+NEEDS_MOUNTS ?= $(USE_QEMU)
+
+SYSROOT_OUT = $(OUT)
+ifneq ($(SYSROOT),)
+  SYSROOT_OUT = $(subst $(SYSROOT),,$(OUT))
+else
+  # Default to / when all the empty-sysroot logic is done.
+  SYSROOT = /
+endif
+
+QEMU_NAME = qemu-$(QEMU_ARCH)
+QEMU_PATH = /build/bin/$(QEMU_NAME)
+QEMU_SYSROOT_PATH = $(SYSROOT)$(QEMU_PATH)
+QEMU_SRC_PATH = /usr/bin/$(QEMU_NAME)
+QEMU_BINFMT_PATH = /proc/sys/fs/binfmt_misc/$(QEMU_NAME)
+QEMU_REGISTER_PATH = /proc/sys/fs/binfmt_misc/register
+
+QEMU_MAGIC_arm = ":$(QEMU_NAME):M::\x7fELF\x01\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x28\x00:\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff\xff:/build/bin/qemu-arm:"
+
+
+#
+# Output full configuration at top level
+#
+
+# Don't show on clean
+ifneq ($(MAKECMDGOALS),clean)
+  $(info build configuration:)
+  $(info - OUT=$(OUT))
+  $(info - SRC=$(SRC))
+  $(info - MODE=$(MODE))
+  $(info - SPLITDEBUG=$(SPLITDEBUG))
+  $(info - NOSTRIP=$(NOSTRIP))
+  $(info - VALGRIND=$(VALGRIND))
+  $(info - COLOR=$(COLOR))
+  $(info - CXXEXCEPTIONS=$(CXXEXCEPTIONS))
+  $(info - ARCH=$(ARCH))
+  $(info - QEMU_ARCH=$(QEMU_ARCH))
+  $(info - USE_QEMU=$(USE_QEMU))
+  $(info - NEEDS_ROOT=$(NEEDS_ROOT))
+  $(info - NEEDS_MOUNTS=$(NEEDS_MOUNTS))
+  $(info - SYSROOT=$(SYSROOT))
+  $(info )
+endif
+
+#
+# Standard targets with detection for when they are improperly configured.
+#
+
+# all does not include tests by default
+all:
+	$(QUIET)(test -z "$^" && \
+	$(ECHO) "You must add your targets as 'all' prerequisites") || true
+	$(QUIET)test -n "$^"
+
+# Builds and runs tests for the target arch
+# Run them in parallel
+# After the test have completed, if profiling, run coverage analysis
+tests:
+ifeq ($(MODE),profiling)
+	@$(ECHO) "COVERAGE [$(COLOR_YELLOW)STARTED$(COLOR_RESET)]"
+	$(QUIET)FILES="";						\
+		for GCNO in `find . -name "*.gcno"`; do			\
+			GCDA="$${GCNO%.gcno}.gcda";			\
+			if [ -e $${GCDA} ]; then			\
+				FILES="$${FILES} $${GCDA}";		\
+			fi						\
+		done;							\
+		if [ -n "$${FILES}" ]; then				\
+			gcov -l $${FILES};				\
+			lcov --capture --directory .			\
+				--output-file=lcov-coverage.info;	\
+			genhtml lcov-coverage.info			\
+				--output-directory lcov-html;		\
+		fi
+	@$(ECHO) "COVERAGE [$(COLOR_YELLOW)FINISHED$(COLOR_RESET)]"
+endif
+.PHONY: tests
+
+qemu_chroot_install:
+ifeq ($(USE_QEMU),1)
+	$(QUIET)$(ECHO) "QEMU   Preparing $(QEMU_NAME)"
+	@# Copying strategy
+	@# Compare /usr/bin/qemu inode to /build/$board/build/bin/qemu, if different
+	@# hard link to a temporary file, then rename temp to target. This should
+	@# ensure that once $QEMU_SYSROOT_PATH exists it will always exist, regardless
+	@# of simultaneous test setups.
+	$(QUIET)if [[ ! -e $(QEMU_SYSROOT_PATH) || \
+	    `stat -c %i $(QEMU_SRC_PATH)` != `stat -c %i $(QEMU_SYSROOT_PATH)` \
+	    ]]; then \
+	  $(ROOT_CMD) ln -Tf $(QEMU_SRC_PATH) $(QEMU_SYSROOT_PATH).$$$$; \
+	  $(ROOT_CMD) mv -Tf $(QEMU_SYSROOT_PATH).$$$$ $(QEMU_SYSROOT_PATH); \
+	fi
+
+	@# Prep the binfmt handler. First mount if needed, then unregister any bad
+	@# mappings and then register our mapping.
+	@# There may still be some race conditions here where one script de-registers
+	@# and another script starts executing before it gets re-registered, however
+	@# it should be rare.
+	-$(QUIET)[[ -e $(QEMU_REGISTER_PATH) ]] || \
+	  $(ROOT_CMD) mount binfmt_misc -t binfmt_misc \
+	    /proc/sys/fs/binfmt_misc
+
+	-$(QUIET)if [[ -e $(QEMU_BINFMT_PATH) && \
+	      `awk '$$1 == "interpreter" {print $$NF}' $(QEMU_BINFMT_PATH)` != \
+	      "$(QEMU_PATH)" ]]; then \
+	  echo -1 | $(ROOT_CMD) tee $(QEMU_BINFMT_PATH) >/dev/null; \
+	fi
+
+	-$(if $(QEMU_MAGIC_$(ARCH)),$(QUIET)[[ -e $(QEMU_BINFMT_PATH) ]] || \
+	  echo $(QEMU_MAGIC_$(ARCH)) | $(ROOT_CMD) tee $(QEMU_REGISTER_PATH) \
+	    >/dev/null)
+endif
+.PHONY: qemu_clean qemu_chroot_install
+
+# TODO(wad) Move to -L $(SYSROOT) and fakechroot when qemu-user
+#           doesn't hang traversing /proc from SYSROOT.
+SUDO_CMD = sudo
+UNSHARE_CMD = unshare
+QEMU_CMD =
+ROOT_CMD = $(if $(filter 1,$(NEEDS_ROOT)),$(SUDO_CMD) , )
+MOUNT_CMD = $(if $(filter 1,$(NEEDS_MOUNTS)),$(ROOT_CMD) mount, \#)
+UMOUNT_CMD = $(if $(filter 1,$(NEEDS_MOUNTS)),$(ROOT_CMD) umount, \#)
+QEMU_LDPATH = $(SYSROOT_LDPATH):/lib64:/lib:/usr/lib64:/usr/lib
+ROOT_CMD_LDPATH = $(SYSROOT_LDPATH):$(SYSROOT)/lib64:
+ROOT_CMD_LDPATH := $(ROOT_CMD_LDPATH):$(SYSROOT)/lib:$(SYSROOT)/usr/lib64:
+ROOT_CMD_LDPATH := $(ROOT_CMD_LDPATH):$(SYSROOT)/usr/lib
+ifeq ($(USE_QEMU),1)
+  export QEMU_CMD = \
+   $(SUDO_CMD) chroot $(SYSROOT) $(QEMU_PATH) \
+   -drop-ld-preload \
+   -E LD_LIBRARY_PATH="$(QEMU_LDPATH):$(patsubst $(OUT),,$(LD_DIRS))" \
+   -E HOME="$(HOME)" -E SRC="$(SRC)" --
+  # USE_QEMU conditional function
+  define if_qemu
+    $(1)
+  endef
+else
+  ROOT_CMD = $(if $(filter 1,$(NEEDS_ROOT)),sudo, ) \
+    LD_LIBRARY_PATH="$(ROOT_CMD_LDPATH):$(LD_DIRS)"
+  define if_qemu
+    $(2)
+  endef
+endif
+
+VALGRIND_CMD =
+ifeq ($(VALGRIND),1)
+  VALGRIND_CMD = /usr/bin/valgrind --tool=memcheck $(VALGRIND_ARGS) --
+endif
+
+define TEST_implementation
+  $(QUIET)$(call TEST_setup)
+  $(QUIET)$(call TEST_run)
+  $(QUIET)$(call TEST_teardown)
+  $(QUIET)exit $$(cat $(OUT)$(TARGET_OR_MEMBER).status.test)
+endef
+
+define TEST_setup
+  @$(ECHO) -n "TEST		$(TARGET_OR_MEMBER) "
+  @$(ECHO) "[$(COLOR_YELLOW)SETUP$(COLOR_RESET)]"
+  $(QUIET)# Setup a target-specific results file
+  $(QUIET)(echo > $(OUT)$(TARGET_OR_MEMBER).setup.test)
+  $(QUIET)(echo 1 > $(OUT)$(TARGET_OR_MEMBER).status.test)
+  $(QUIET)(echo > $(OUT)$(TARGET_OR_MEMBER).cleanup.test)
+  $(QUIET)# No setup if we are not using QEMU
+  $(QUIET)# TODO(wad) this is racy until we use a vfs namespace
+  $(call if_qemu,\
+    $(QUIET)(echo "mkdir -p '$(SYSROOT)/proc' '$(SYSROOT)/dev' \
+                            '$(SYSROOT)/mnt/host/source'" \
+             >> "$(OUT)$(TARGET_OR_MEMBER).setup.test"))
+  $(call if_qemu,\
+    $(QUIET)(echo "$(MOUNT_CMD) --bind /mnt/host/source \
+             '$(SYSROOT)/mnt/host/source'" \
+             >> "$(OUT)$(TARGET_OR_MEMBER).setup.test"))
+  $(call if_qemu,\
+    $(QUIET)(echo "$(MOUNT_CMD) --bind /proc '$(SYSROOT)/proc'" \
+             >> "$(OUT)$(TARGET_OR_MEMBER).setup.test"))
+  $(call if_qemu,\
+    $(QUIET)(echo "$(MOUNT_CMD) --bind /dev '$(SYSROOT)/dev'" \
+             >> "$(OUT)$(TARGET_OR_MEMBER).setup.test"))
+endef
+
+define TEST_teardown
+  @$(ECHO) -n "TEST		$(TARGET_OR_MEMBER) "
+  @$(ECHO) "[$(COLOR_YELLOW)TEARDOWN$(COLOR_RESET)]"
+  $(call if_qemu, $(QUIET)$(SHELL) "$(OUT)$(TARGET_OR_MEMBER).cleanup.test")
+endef
+
+# Use GTEST_ARGS.[arch] if defined.
+override GTEST_ARGS.real = \
+ $(call if_qemu,$(GTEST_ARGS.qemu.$(QEMU_ARCH)),$(GTEST_ARGS.host.$(HOST_ARCH)))
+
+define TEST_run
+  @$(ECHO) -n "TEST		$(TARGET_OR_MEMBER) "
+  @$(ECHO) "[$(COLOR_GREEN)RUN$(COLOR_RESET)]"
+  $(QUIET)(echo 1 > "$(OUT)$(TARGET_OR_MEMBER).status.test")
+  $(QUIET)(echo $(ROOT_CMD) SRC="$(SRC)" $(QEMU_CMD) $(VALGRIND_CMD) \
+    "$(strip $(call if_qemu, $(SYSROOT_OUT),$(OUT))$(TARGET_OR_MEMBER))" \
+      $(if $(filter-out 0,$(words $(GTEST_ARGS.real))),$(GTEST_ARGS.real),\
+           $(GTEST_ARGS)) >> "$(OUT)$(TARGET_OR_MEMBER).setup.test")
+  -$(QUIET)$(call if_qemu,$(SUDO_CMD) $(UNSHARE_CMD) -m) $(SHELL) \
+      $(OUT)$(TARGET_OR_MEMBER).setup.test \
+  && echo 0 > "$(OUT)$(TARGET_OR_MEMBER).status.test"
+endef
+
+# Recursive list reversal so that we get RMDIR_ON_CLEAN in reverse order.
+define reverse
+$(if $(1),$(call reverse,$(wordlist 2,$(words $(1)),$(1)))) $(firstword $(1))
+endef
+
+clean: qemu_clean
+clean: CLEAN($(OUT)*.d) CLEAN($(OUT)*.o) CLEAN($(OUT)*.debug)
+clean: CLEAN($(OUT)*.test) CLEAN($(OUT)*.depends)
+clean: CLEAN($(OUT)*.gcno) CLEAN($(OUT)*.gcda) CLEAN($(OUT)*.gcov)
+clean: CLEAN($(OUT)lcov-coverage.info) CLEAN($(OUT)lcov-html)
+
+clean:
+	$(QUIET)# Always delete the containing directory last.
+	$(call silent_rmdir,$(OUT))
+
+FORCE: ;
+# Empty rule for use when no special targets are needed, like large_tests
+NONE:
+
+.PHONY: clean NONE valgrind NONE
+.DEFAULT_GOAL  :=  all
+# Don't let make blow away "intermediates"
+.PRECIOUS: %.pic.o %.pie.o %.a %.pic.a %.pie.a %.test
+
+# Start accruing build info
+OUT_DIRS = $(OUT)
+LD_DIRS = $(OUT)
+SRC_DIRS = $(SRC)
+
+include $(wildcard $(OUT)*.d)
+SUBMODULE_DIRS = $(wildcard $(SRC)/*/module.mk)
+include $(SUBMODULE_DIRS)
+
+
+else  ## In duplicate inclusions of common.mk
+
+# Get the current inclusion directory without a trailing slash
+MODULE := $(patsubst %/,%, \
+           $(dir $(lastword $(filter-out %common.mk,$(MAKEFILE_LIST)))))
+MODULE := $(subst $(SRC)/,,$(MODULE))
+MODULE_NAME := $(subst /,_,$(MODULE))
+#VPATH := $(MODULE):$(VPATH)
+
+
+# Depth first
+$(eval OUT_DIRS += $(OUT)$(MODULE))
+$(eval SRC_DIRS += $(OUT)$(MODULE))
+$(eval LD_DIRS := $(LD_DIRS):$(OUT)$(MODULE))
+
+# Add the defaults from this dir to rm_clean
+clean: CLEAN($(OUT)$(MODULE)/*.d) CLEAN($(OUT)$(MODULE)/*.o)
+clean: CLEAN($(OUT)$(MODULE)/*.debug) CLEAN($(OUT)$(MODULE)/*.test)
+clean: CLEAN($(OUT)$(MODULE)/*.depends)
+clean: CLEAN($(OUT)$(MODULE)/*.gcno) CLEAN($(OUT)$(MODULE)/*.gcda)
+clean: CLEAN($(OUT)$(MODULE)/*.gcov) CLEAN($(OUT)lcov-coverage.info)
+clean: CLEAN($(OUT)lcov-html)
+
+$(info + submodule: $(MODULE_NAME))
+# We must eval otherwise they may be dropped.
+MODULE_C_OBJECTS = $(patsubst $(SRC)/$(MODULE)/%.c,$(MODULE)/%.o,\
+  $(wildcard $(SRC)/$(MODULE)/*.c))
+$(eval $(MODULE_NAME)_C_OBJECTS ?= $(MODULE_C_OBJECTS))
+MODULE_CXX_OBJECTS = $(patsubst $(SRC)/$(MODULE)/%.cc,$(MODULE)/%.o,\
+  $(wildcard $(SRC)/$(MODULE)/*.cc))
+$(eval $(MODULE_NAME)_CXX_OBJECTS ?= $(MODULE_CXX_OBJECTS))
+
+# Note, $(MODULE) is implicit in the path to the %.c.
+# See $(C_OBJECTS) for more details.
+# Register rules for the module objects.
+$(eval $(call add_object_rules,$(MODULE_C_OBJECTS),CC,c,CFLAGS,$(SRC)/))
+$(eval $(call add_object_rules,$(MODULE_CXX_OBJECTS),CXX,cc,CXXFLAGS,$(SRC)/))
+
+# Continue recursive inclusion of module.mk files
+SUBMODULE_DIRS = $(wildcard $(SRC)/$(MODULE)/*/module.mk)
+include $(wildcard $(OUT)$(MODULE)/*.d)
+include $(SUBMODULE_DIRS)
+
+endif
+endif  ## pass-to-subcall wrapper for relocating the call directory