#
# \brief  Front end to the Genode build system
# \author Norman Feske
# \date   2011-08-04
#

#
# The operation of the build system can be tuned using the following variables,
# which can be specified at the command line or supplied via the
# 'etc/build.conf' file.
#
# BASE_DIR       - this directory points to Genode's 'base' repository
# REPOSITORIES   - list of directories incorporared into the build process
# VERBOSE        - variable that controls the verboseness of the build process
#
#                  By default, compiler messages are not displayed. If you are
#                  interested in these messages set this variable to nothing.
#                  ('VERBOSE=')
#
# VERBOSE_MK    - variable that controls the verboseness of make invocations
# VERBOSE_DIR   - variable that controls the verboseness of changing directories
#
#                 Using this variable, you can enable the make messages printed
#                 when changing directories. To enable the messages, set the
#                 variable to nothing.
#
# LIB_CACHE_DIR - location of the library build cache
#
#                 This variable defines the place for the library build cache.
#                 Normally, the libcache is located at 'var/libcache' and
#                 there is no need to change it.
#
# CONTRIB_DIR   - location of ported 3rd-party source codes
#
# REQUIRED_GCC_VERSION - GCC version required for building Genode
#

##
## Define global configuration variables
##

-include etc/build.conf

BUILD_BASE_DIR := $(CURDIR)
INSTALL_DIR    := $(CURDIR)/bin

export BASE_DIR         ?= ../base
export REPOSITORIES     ?= $(BASE_DIR:%base=%base-linux) $(BASE_DIR)
export VERBOSE          ?= @
export VERBOSE_DIR      ?= --no-print-directory
export VERBOSE_MK       ?= @
export LIB_CACHE_DIR    ?= $(BUILD_BASE_DIR)/var/libcache
export LIB_PROGRESS_LOG ?= $(BUILD_BASE_DIR)/progress.log
export LIB_DEP_FILE     ?= var/libdeps
export ECHO             ?= echo -e
export CONTRIB_DIR

#
# Convert user-defined directories to absolute directories
#
# The 'echo' shell command expands '~' characters to the home directory,
# 'realpath' converts relative path names to absolute.
#
REPOSITORIES := $(realpath $(shell echo $(REPOSITORIES)))
BASE_DIR     := $(realpath $(shell echo $(BASE_DIR)))

#
# Configure shell program before executing any shell commands. On Ubuntu the
# standard shell is dash, which breaks colored output via its built-in echo
# command.
#
export SHELL := $(shell which bash)

select_from_repositories = $(firstword $(foreach REP,$(REPOSITORIES),$(wildcard $(REP)/$(1))))

-include $(call select_from_repositories,etc/specs.conf)
-include $(BUILD_BASE_DIR)/etc/specs.conf
export SPEC_FILES := $(foreach SPEC,$(SPECS),$(call select_from_repositories,mk/spec-$(SPEC).mk))
include $(SPEC_FILES)
export SPECS

include $(BASE_DIR)/mk/global.mk

export LIBGCC_INC_DIR = $(shell dirname `$(CUSTOM_CXX_LIB) -print-libgcc-file-name`)/include

#
# Find out about the target directories to build
#
DST_DIRS := $(filter-out clean cleanall again run/%,$(MAKECMDGOALS))

ifeq ($(MAKECMDGOALS),)
DST_DIRS := *
endif

#
# Tool chain version check
#
# If SPECS contains 'always_hybrid' we skip the check as the host tool chain is
# used. Also, empty DST_DIRS is interpreted as a tool-chain agnostic target,
# e.g., clean.
#
ifeq ($(filter always_hybrid,$(SPECS)),)
ifneq ($(DST_DIRS),)
REQUIRED_GCC_VERSION ?= 4.9.2
GCC_VERSION := $(filter $(REQUIRED_GCC_VERSION) ,$(shell $(CUSTOM_CXX) --version))
ifneq ($(GCC_VERSION), $(REQUIRED_GCC_VERSION))
$(error "GCC version $(REQUIRED_GCC_VERSION) is required")
endif
endif
endif

#
# Default rule: build all directories specified as make arguments
#
_all $(DST_DIRS): gen_deps_and_build_targets
	@true

##
## First stage: generate library dependencies
##

#
# Reset library-build log and library-dependency file
#
# The 'progress' file contains the names of the already processed libraries
# of the current build process. Before considering to process any library,
# the build system checks if the library is already present in the 'progress'
# file and, if yes, skips it.
#
.PHONY: init_progress_log
init_progress_log:
	@echo "#" > $(LIB_PROGRESS_LOG)
	@echo "# Library build progress log - generated by dep_prg.mk and dep_lib.mk" >> $(LIB_PROGRESS_LOG)
	@echo "#" >> $(LIB_PROGRESS_LOG)

.PHONY: init_libdep_file
init_libdep_file: $(dir $(LIB_DEP_FILE))
	@echo "checking library dependencies..."
	@(echo "#"; \
	  echo "# Library dependencies for build '$(DST_DIRS)'"; \
	  echo "#"; \
	  echo ""; \
	  echo "export SPEC_FILES := \\"; \
	  for i in $(SPEC_FILES); do \
	    echo "  $$i \\"; done; \
	  echo ""; \
	  echo "LIB_CACHE_DIR = $(LIB_CACHE_DIR)"; \
	  echo "BASE_DIR      = $(realpath $(BASE_DIR))"; \
	  echo "VERBOSE      ?= $(VERBOSE)"; \
	  echo "VERBOSE_MK   ?= $(VERBOSE_MK)"; \
	  echo "VERBOSE_DIR  ?= $(VERBOSE_DIR)"; \
	  echo "INSTALL_DIR  ?= $(INSTALL_DIR)"; \
	  echo "SHELL        ?= $(SHELL)"; \
	  echo "MKDIR        ?= mkdir"; \
	  echo ""; \
	  echo "all:"; \
	  echo "	@true # prevent nothing-to-be-done message"; \
	  echo "") > $(LIB_DEP_FILE)

#
# We check if any target.mk files exist in the specified directories within
# any of the repositories listed in the 'REPOSITORIES' variable.
#

$(dir $(LIB_DEP_FILE)):
	@mkdir -p $@

#
# Find all 'target.mk' files located within any of the specified subdirectories
# ('DST_DIRS') and any repository. The 'sort' is used to remove duplicates.
#
TARGETS_TO_VISIT := $(shell find $(REPOSITORIES:=/src) -false \
                            $(foreach DST,$(DST_DIRS), \
                                      -or -path "*/src/$(DST)/**target.mk" \
                                          -printf " %P "))
TARGETS_TO_VISIT := $(sort $(TARGETS_TO_VISIT))

#
# Perform sanity check for non-existing targets being specified at the command
# line.
#
MISSING_TARGETS := $(strip \
                     $(foreach DST,$(DST_DIRS),\
                       $(if $(filter $(DST)/%,$(TARGETS_TO_VISIT)),,$(DST))))

ifneq ($(MAKECMDGOALS),)
ifneq ($(MISSING_TARGETS),)
init_libdep_file: error_missing_targets
error_missing_targets:
	@for target in $(MISSING_TARGETS); do \
	  echo "Error: target '$$target' does not exist"; done
	@false;
endif
endif

#
# The procedure of collecting library dependencies is realized as a single
# rule to gain maximum performance. If we invoked a rule for each target,
# we would need to spawn one additional shell per target, which would take
# 10-20 percent more time.
#
traverse_dependencies: $(dir $(LIB_DEP_FILE)) init_libdep_file init_progress_log
	$(VERBOSE_MK) \
	for target in $(TARGETS_TO_VISIT); do \
	  for rep in $(REPOSITORIES); do \
	    test -f $$rep/src/$$target || continue; \
	    $(MAKE) $(VERBOSE_DIR) -f $(BASE_DIR)/mk/dep_prg.mk \
	            REP_DIR=$$rep TARGET_MK=$$rep/src/$$target \
	            BUILD_BASE_DIR=$(BUILD_BASE_DIR) \
	            SHELL=$(SHELL) \
	            DARK_COL="$(DARK_COL)" DEFAULT_COL="$(DEFAULT_COL)" || result=false; \
	    break; \
	  done; \
	done; $$result;

.PHONY: $(LIB_DEP_FILE)
$(LIB_DEP_FILE): traverse_dependencies

##
## Second stage: build targets based on the result of the first stage
##

$(INSTALL_DIR):
	$(VERBOSE)mkdir -p $@

.PHONY: gen_deps_and_build_targets
gen_deps_and_build_targets: $(INSTALL_DIR) $(LIB_DEP_FILE)
	@$(VERBOSE_MK)$(MAKE) $(VERBOSE_DIR) -f $(LIB_DEP_FILE) all

.PHONY: again
again: $(INSTALL_DIR)
	@$(VERBOSE_MK)$(MAKE) $(VERBOSE_DIR) -f $(LIB_DEP_FILE) all

##
## Rules for running automated test cases
##

RUN_OPT ?=

# helper for run/% rule
RUN_SCRIPT = $(call select_from_repositories,run/$*.run)

#
# Read tools configuration to obtain the cross-compiler prefix passed
# to the run script.
#
-include $(call select_from_repositories,etc/tools.conf)

run/%: $(call select_from_repositories,run/%.run) $(RUN_ENV)
	$(VERBOSE)test -f "$(RUN_SCRIPT)" || (echo "Error: No run script for $*"; exit -1)
	$(VERBOSE)$(GENODE_DIR)/tool/run/run --genode-dir $(GENODE_DIR) \
	                                     --name $* \
	                                     --specs "$(SPECS)" \
	                                     --repositories "$(REPOSITORIES)" \
	                                     --cross-dev-prefix "$(CROSS_DEV_PREFIX)" \
	                                     --qemu-args "$(QEMU_OPT)" \
	                                     $(RUN_OPT) \
	                                     --include $(RUN_SCRIPT)

##
## Clean rules
##

#
# For cleaning, visit each directory for that a corresponding target.mk
# file exists in the source tree. For each such directory, we call
# the single_target rule.
#
clean_targets:
	$(VERBOSE_MK)for d in `$(GNU_FIND) -mindepth 1 -type d | $(TAC) | sed "s/^..//"`; do \
		for r in $(REPOSITORIES); do \
			test -f $$r/src/$$d/target.mk && \
				$(MAKE) $(VERBOSE_DIR) clean \
					-C $$d \
					-f $(BASE_DIR)/mk/prg.mk \
					BUILD_BASE_DIR=$(BUILD_BASE_DIR) \
					PRG_REL_DIR=$$d \
					SHELL=$(SHELL) \
					REP_DIR=$$r || \
				true; \
		done; \
	done

clean_libcache:
	$(VERBOSE)rm -rf var/libcache

clean_run:
	$(VERBOSE)rm -rf var/run
	$(VERBOSE)rm -rf config-00-00-00-00-00-00

clean_gen_files:
	$(VERBOSE)rm -f $(LIB_PROGRESS_LOG)
	$(VERBOSE)rm -f $(LIB_DEP_FILE)

clean_install_dir:
	$(VERBOSE)(test -d $(INSTALL_DIR) && find $(INSTALL_DIR) -type l -not -readable -delete) || true

clean_empty_dirs: clean_targets clean_libcache clean_run clean_gen_files clean_install_dir
	$(VERBOSE)$(GNU_FIND) . -depth -type d -empty -delete

clean cleanall: clean_empty_dirs