New extensible build system - initial work

make/build/config.mk

@@ -0,0 +1,55 @@
+# This file is included by the top-level Makefile.  It sets up
+# standard variables based on the current configuration and
+# platform that are not specific to what is being built.
+
+# Always use bash, not whatever is installed as /bin/sh
+SHELL := /bin/bash
+
+# Utility variables
+
+empty :=
+space := $(empty) $(empty)
+comma := ,
+
+# Note: make removes the newline immediately prior to `endef`
+define newline
+
+
+endef
+
+backslash := \a
+backslash := $(patsubst %a,%,$(backslash))
+
+
+# ###############################################################
+# Build system internal files
+# ###############################################################
+
+BUILD_COMBOS:= $(BUILD_SYSTEM)/combo
+
+CLEAR_VARS:= $(BUILD_SYSTEM)/clear_vars.mk
+# TODO: BUILD_STATIC_LIBRARY := $(BUILD_SYSTEM)/static_library.mk
+# TODO: BUILD_HOST_EXECUTABLE := $(BUILD_SYSTEM)/host_executable.mk
+# TODO: BUILD_TARGET_EXECUTABLE := $(BUILD_SYSTEM)/target_executable.mk
+
+
+# ###############################################################
+# Include sub-configuration files
+# ###############################################################
+
+# This sets up most of the global variables that are specific to the
+# user's build configuration.
+include $(BUILD_SYSTEM)/envsetup.mk
+
+# ###############################################################
+# Generic tools
+# ###############################################################
+
+COLUMN := column
+
+# It's called md5 on Mac OS and md5sum on Linux
+ifeq ($(HOST_OS),darwin)
+MD5SUM:=md5 -q
+else
+MD5SUM:=md5sum
+endif

make/build/definitions.mk

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+# Common build system definitions.  Mostly helpful shortcuts or
+# functions, since we don't actually compile code here.
+
+# The names of all packages in the system.
+ALL_PACKAGES :=
+
+
+###########################################################
+## Debugging; prints a variable list to stdout
+###########################################################
+
+# $(1): variable name list, not variable values
+define print-vars
+$(foreach var,$(1), \
+  $(info $(var):) \
+  $(foreach word,$($(var)), \
+    $(info $(space)$(space)$(word)) \
+   ) \
+ )
+endef
+
+
+###########################################################
+## Retrieve the directory of the current makefile
+## Must be called before including any other makefile!!
+###########################################################
+
+# Figure out where we are.
+define my-dir
+$(strip \
+  $(eval LOCAL_MODULE_MAKEFILE := $$(lastword $$(MAKEFILE_LIST))) \
+  $(if $(filter $(BUILD_SYSTEM)/% $(OUT_DIR)/%,$(LOCAL_MODULE_MAKEFILE)), \
+    $(error my-dir must be called before including any other makefile.) \
+   , \
+    $(patsubst %/,%,$(dir $(LOCAL_MODULE_MAKEFILE))) \
+   ) \
+ )
+endef
+
+
+###########################################################
+## Function we can evaluate to introduce a dynamic dependency
+###########################################################
+
+define add-dependency
+$(1): $(2)
+endef
+
+
+###########################################################
+## Run rot13 on a string
+## $(1): the string.  Must be one line.
+###########################################################
+
+define rot13
+$(shell echo $(1) | tr 'a-zA-Z' 'n-za-mN-ZA-M')
+endef
+
+
+###########################################################
+## Returns true if $(1) and $(2) are equal.  Returns
+## the empty string if they are not equal.
+###########################################################
+
+define streq
+$(strip $(if $(strip $(1)),\
+  $(if $(strip $(2)),\
+    $(if $(filter-out __,_$(subst $(strip $(1)),,$(strip $(2)))$(subst $(strip $(2)),,$(strip $(1)))_),,true), \
+    ),\
+  $(if $(strip $(2)),\
+    ,\
+    true)\
+ ))
+endef
+
+
+###########################################################
+## TODO: Command for running 'make' to build an output
+## TODO: Command for running ./configure to prepare a build
+###########################################################

make/build/envsetup.mk

@@ -0,0 +1,43 @@
+# ---------------------------------------------------------------
+# Set up configuration for the host machine.
+UNAME := $(shell uname -sm)
+
+ifneq (,$(findstring Linux,$(UNAME)))
+  HOST_OS := linux
+endif
+ifneq (,$(findstring Darwin,$(UNAME)))
+  HOST_OS := darwin
+endif
+ifneq (,$(findstring Macintosh,$(UNAME)))
+  HOST_OS := darwin
+endif
+ifneq (,$(findstring CYGWIN,$(UNAME)))
+  HOST_OS := windows
+endif
+
+ifeq ($(HOST_OS),)
+$(error Unable to determine HOST_OS from uname -sm: $(UNAME)!)
+endif
+
+ifneq (,$(findstring x86_64,$(UNAME)))
+  HOST_ARCH := x86_64
+else
+ifneq (,$(findstring x86,$(UNAME)))
+$(error Building on a 32-bit x86 host is not supported: $(UNAME)!)
+endif
+endif
+
+ifeq ($(HOST_ARCH),)
+$(error Unable to determine HOST_ARCH from uname -sm: $(UNAME)!)
+endif
+
+
+# ---------------------------------------------------------------
+# Figure out the output directory
+ifeq (,$(strip $(OUT_DIR)))
+OUT_DIR := $(TOPDIR)out
+endif
+
+
+# ---------------------------------------------------------------
+# TODO: figure out the target output dir, etc...

make/build/main.mk

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+# Always use bash, not whatever is installed as /bin/sh
+SHELL := /bin/bash
+
+# Disable built-in suffix rules.
+.SUFFIXES:
+
+# Turn off the RCS / SCCS implicit rules of GNU Make
+% : RCS/%,v
+% : RCS/%
+% : %,v
+% : s.%
+% : SCCS/s.%
+
+# If a rule fails, delete $@.
+.DELETE_ON_ERROR:
+
+# Check for broken versions of make.
+# (Allow any version under Cygwin since we don't actually build the platform there.)
+ifneq (1,$(strip $(shell expr $(MAKE_VERSION) \>= 3.81)))
+$(warning ********************************************************************************)
+$(warning *  You are using version $(MAKE_VERSION) of make.)
+$(warning *  Android can only be built by versions 3.81 and higher.)
+$(warning *  see https://source.android.com/source/download.html)
+$(warning ********************************************************************************)
+$(error stopping)
+endif
+
+# Absolute path of the present working direcotry.
+# This overrides the shell variable $PWD, which does not necessarily point to
+# the top of the source tree, for example when "make -C" is used.
+PWD := $(shell pwd)
+
+TOP := .
+TOPDIR :=
+
+# This is the default target.  It must be the first declared target.
+.PHONY: all
+DEFAULT_GOAL := all
+$(DEFAULT_GOAL):
+
+# The path to the directory containing our build system's Makefiles.
+BUILD_SYSTEM := $(TOPDIR)build
+
+# Set up standard variables based on configuration.
+include $(BUILD_SYSTEM)/config.mk
+
+# Check the sanity of the build tools.
+VERSION_CHECK_SEQUENCE_NUMBER := 5
+-include $(OUT_DIR)/versions_checked.mk
+ifneq ($(VERSION_CHECK_SEQUENCE_NUMBER),$(VERSIONS_CHECKED))
+
+$(info Checking build tools versions...)
+
+# Make sure that there are no spaces in the absolute path; the
+# build system can't deal with them.
+ifneq ($(words $(shell pwd)),1)
+$(warning ************************************************************)
+$(warning You are building in a directory whose absolute path contains)
+$(warning a space character:)
+$(warning $(space))
+$(warning "$(shell pwd)")
+$(warning $(space))
+$(warning Please move your source tree to a path that does not contain)
+$(warning any spaces.)
+$(warning ************************************************************)
+$(error Directory names containing spaces not supported)
+endif
+
+# Now that we've checked all our build tools, write the include file that we
+# load next time.
+$(shell echo 'VERSIONS_CHECKED := $(VERSION_CHECK_SEQUENCE_NUMBER)' \
+        > $(OUT_DIR)/versions_checked.mk)
+endif
+
+# Bring in standard build system definitions
+include $(BUILD_SYSTEM)/definitions.mk

make/out/.gitignore

@@ -0,0 +1,2 @@
+*
+!.gitignore