utl/test/Makefile

#
# Makefile
# 
# Main makefile for utl Unit test
#
# Copyright (C) 2019 Christos Choutouridis <christos@choutouridis.net>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as
# published by the Free Software Foundation, either version 3
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#

# ========== Project settings ==========
TARGET   	:= utlTest.exe
SRC_DIR		:= tests gtest
INC_DIR		:= ../include gtest
EXC_FILE	:= 

# build directories
BUILD_DIR  	:= bin
OBJ_DIR  	:= $(BUILD_DIR)/obj
DEP_DIR		:= $(BUILD_DIR)/.dep


# ========== Compiler settings ==========
CXX			:= g++
CPP			:= g++ -E
CSIZE			:= size

CFLAGS 		:= -std=c++14 -Wall -Wextra
DEB_FLAGS	:= -DDEBUG -g3
REL_FLAGS	:= -O3
LDFLAGS  	:=

PRE_DEFS		:= 

MAP_FILE		:= $(BUILD_DIR)/output.map
MAP_FLAG		:= -Xlinker -Map=$(MAP_FILE)



#
# =========== Main body and Patterns ===========
#
INC  			:= $(foreach dir,$(INC_DIR),-I$(dir))
DEF  			:= $(foreach def,$(PRE_DEFS),-D$(def))

# source files
# recursive search into current and source directories
SRC			:= $(wildcard *.cpp)
SRC			+= $(foreach dir,$(SRC_DIR),$(wildcard $(dir)/*.cpp))
SRC			+= $(foreach dir,$(SRC_DIR),$(wildcard $(dir)/**/*.cpp))
# exclude every file from the exclude file list
SRC			:= $(filter-out $(wildcard $(EXC_FILE)),$(SRC))

OBJ 			:= $(foreach file,$(SRC:%.cpp=%.o),$(OBJ_DIR)/$(file))
DEP			:= $(foreach file,$(SRC:%.cpp=%.d),$(DEP_DIR)/$(file))


# Make Dependencies pattern.
# This little trick enables recompilation only when dependencies change
# and it does so for changes both in source AND header files ;)
# 
# It is based on Tom Tromey's method.
# 
# Invoke cpp to create makefile rules with dependencies for each source file
$(DEP_DIR)/%.d: %.cpp
	@mkdir -p $(@D)
	@$(CPP) $(CFLAGS) $(INC) $(DEF) -MM -MT $(OBJ_DIR)/$(<:.cpp=.o) -MF $@ $<


# objects depent on .cpp AND dependency files, which have an empty recipe 
$(OBJ_DIR)/%.o: %.cpp $(DEP_DIR)/%.d
	@mkdir -p $(@D)
	$(CXX) -c $(CFLAGS) $(INC) $(DEF) -o $@ $<

# empty recipe for dependency files. This prevents make errors
$(DEP):

# now include all dependencies
# After all they are makefile dependency rules ;)
include $(wildcard $(DEP))

# main target rule
$(BUILD_DIR)/$(TARGET): $(OBJ)
	@mkdir -p $(@D)
	@echo Linking to target: $(TARGET)
	@echo $(CXX) $(LDFLAGS) $(MAP_FLAG) -o $(@D)/$(TARGET) '$$(OBJ)'
	@$(CXX) $(LDFLAGS) $(MAP_FLAG) -o $(@D)/$(TARGET) $(OBJ)
	@echo
	@echo Print size information
	@$(CSIZE) $(@D)/$(TARGET)
	@echo Done


.PHONY: clean
clean:
	@echo Cleaning build directories
	@rm -rf $(OBJ_DIR)
	@rm -rf $(DEP_DIR)
	@rm -rf $(BUILD_DIR)



#
# ============ User Rules =============
#

.PHONY: debug
debug: CFLAGS += $(DEB_FLAGS)
debug: $(BUILD_DIR)/$(TARGET)


.PHONY: release
release: CFLAGS += $(REL_FLAGS)
release: clean $(BUILD_DIR)/$(TARGET)


.PHONY: all
all: clean release