#----------------------------------------------------------------------
# Clients fill in the source files to build
#----------------------------------------------------------------------
# C_SOURCES := main.c
# CXX_SOURCES :=
# OBJC_SOURCES :=
# OBJCXX_SOURCES :=
# DYLIB_C_SOURCES :=

# Uncomment line below for debugging shell commands
# SHELL = /bin/sh -x

#----------------------------------------------------------------------
# If ARCH is not defined, default to x86_64.
# If OS is not defined, use 'uname -s' to determine the OS name.
#----------------------------------------------------------------------
ifeq "$(ARCH)" ""
	ARCH = x86_64
endif

ifeq "$(OS)" ""
	OS = $(shell uname -s)
endif

#----------------------------------------------------------------------
# CC defaults to gcc.
# See also these functions:
#   o cxx_compiler
#   o cxx_linker
#----------------------------------------------------------------------
CC ?= gcc
ifeq "$(CC)" "cc"
	CC = gcc
endif

#----------------------------------------------------------------------
# Change any build/tool options needed
#----------------------------------------------------------------------
CFLAGS ?= -gdwarf-2 -O0
CXXFLAGS +=$(CFLAGS)
LD = $(CC)
LDFLAGS ?= $(CFLAGS)
OBJECTS =
EXE ?= a.out

ifeq "$(OS)" "Darwin"
	CFLAGS += -arch $(ARCH)
	DS := /usr/bin/dsymutil
	DSFLAGS =
	DSYM = $(EXE).dSYM
endif

ifneq "$(DYLIB_NAME)" ""
	ifeq "$(OS)" "Darwin"
		DYLIB_FILENAME = lib$(DYLIB_NAME).dylib
	else
		DYLIB_FILENAME = lib$(DYLIB_NAME).so
	endif
endif

# Function that returns the counterpart C++ compiler, given $(CC) as arg.
cxx_compiler = $(if $(findstring clang,$(1)), $(subst clang,clang++,$(1)), $(if $(findstring llvm-gcc,$(1)), $(subst llvm-gcc,llvm-g++,$(1)), $(subst gcc,g++,$(1))))

# Function that returns the C++ linker, given $(CC) as arg.
cxx_linker = $(if $(findstring clang,$(1)), $(subst clang,g++,$(1)), $(if $(findstring llvm-gcc,$(1)), $(subst llvm-gcc,g++,$(1)), $(subst gcc,g++,$(1))))

#----------------------------------------------------------------------
# dylib settings
#----------------------------------------------------------------------
ifneq "$(strip $(DYLIB_C_SOURCES))" ""
	DYLIB_OBJECTS +=$(strip $(DYLIB_C_SOURCES:.c=.o))
endif


#----------------------------------------------------------------------
# Check if we have any C source files
#----------------------------------------------------------------------
ifneq "$(strip $(C_SOURCES))" ""
	OBJECTS +=$(strip $(C_SOURCES:.c=.o))
endif

#----------------------------------------------------------------------
# Check if we have any C++ source files
#----------------------------------------------------------------------
ifneq "$(strip $(CXX_SOURCES))" ""
	OBJECTS +=$(strip $(CXX_SOURCES:.cpp=.o))
	CXX = $(call cxx_compiler,$(CC))
	LD = $(call cxx_linker,$(CC))
endif

#----------------------------------------------------------------------
# Check if we have any ObjC source files
#----------------------------------------------------------------------
ifneq "$(strip $(OBJC_SOURCES))" ""
	OBJECTS +=$(strip $(OBJC_SOURCES:.m=.o))
	LDFLAGS +=-lobjc
endif

#----------------------------------------------------------------------
# Check if we have any ObjC++ source files
#----------------------------------------------------------------------
ifneq "$(strip $(OBJCXX_SOURCES))" ""
	OBJECTS +=$(strip $(OBJCXX_SOURCES:.mm=.o))
	CXX = $(call cxx_compiler,$(CC))
	LD = $(call cxx_linker,$(CC))
	ifeq $(findstring lobjc,$(LDFLAGS)) ""
		LDFLAGS +=-lobjc
	endif
endif


#----------------------------------------------------------------------
# Make the dSYM file from the executable if $(MAKE_DSYM) != "NO"
#----------------------------------------------------------------------
ifeq "$(OS)" "Darwin"
ifneq "$(MAKE_DSYM)" "NO"
$(DSYM) : $(EXE)
	$(DS) $(DSFLAGS) -o "$(DSYM)" "$(EXE)"
endif
endif

#----------------------------------------------------------------------
# Compile the executable from all the objects.
#----------------------------------------------------------------------
ifeq "$(DYLIB_NAME)" ""
$(EXE) : $(OBJECTS)
	$(LD) $(LDFLAGS) $(OBJECTS) -o "$(EXE)"
else
$(EXE) : $(OBJECTS) $(DYLIB_FILENAME)
	$(LD) $(LDFLAGS) $(OBJECTS) -L. -l$(DYLIB_NAME) -o "$(EXE)"
endif

#----------------------------------------------------------------------
# Make the dylib
#----------------------------------------------------------------------
$(DYLIB_FILENAME) : $(DYLIB_OBJECTS)
ifeq "$(OS)" "Darwin"
	$(LD) $(LDFLAGS) $(DYLIB_OBJECTS) -install_name "@executable_path/$(DYLIB_FILENAME)" -dynamiclib -o "$(DYLIB_FILENAME)"
else
	$(LD) $(LDFLAGS) $(DYLIB_OBJECTS) -shared -o "$(DYLIB_FILENAME)"
endif

#----------------------------------------------------------------------
# Automatic variables based on items already entered. Below we create
# an objects lists from the list of sources by replacing all entries
# that end with .c with .o, and we also create a list of prerequisite
# files by replacing all .c files with .d.
#----------------------------------------------------------------------
PREREQS := $(OBJECTS:.o=.d)
ifneq "$(DYLIB_NAME)" ""
	DYLIB_PREREQS := $(DYLIB_OBJECTS:.o=.d)
endif

#----------------------------------------------------------------------
# Rule for Generating Prerequisites Automatically using .d files and
# the compiler -MM option. The -M option will list all system headers,
# and the -MM option will list all non-system dependencies.
#----------------------------------------------------------------------
%.d: %.c
	@set -e; rm -f $@; \
	$(CC) -M $(CPPFLAGS) $< > $@.$$$$; \
	sed 's,\($*\)\.o[ :]*,\1.o $@ : ,g' < $@.$$$$ > $@; \
	rm -f $@.$$$$

%.d: %.cpp
	@set -e; rm -f $@; \
	$(CC) -M $(CPPFLAGS) $< > $@.$$$$; \
	sed 's,\($*\)\.o[ :]*,\1.o $@ : ,g' < $@.$$$$ > $@; \
	rm -f $@.$$$$

%.d: %.m
	@set -e; rm -f $@; \
	$(CC) -M $(CPPFLAGS) $< > $@.$$$$; \
	sed 's,\($*\)\.o[ :]*,\1.o $@ : ,g' < $@.$$$$ > $@; \
	rm -f $@.$$$$

%.d: %.mm
	@set -e; rm -f $@; \
	$(CC) -M $(CPPFLAGS) $< > $@.$$$$; \
	sed 's,\($*\)\.o[ :]*,\1.o $@ : ,g' < $@.$$$$ > $@; \
	rm -f $@.$$$$

#----------------------------------------------------------------------
# Include all of the makefiles for each source file so we don't have
# to manually track all of the prerequisites for each source file.
#----------------------------------------------------------------------
sinclude $(PREREQS)
ifneq "$(DYLIB_NAME)" ""
	sinclude $(DYLIB_PREREQS)
endif

.PHONY: clean
dsym:	$(DSYM)
all:	$(EXE) $(DSYM)
clean::
ifeq "$(DYLIB_NAME)" ""
	rm -rf "$(EXE)" "$(DSYM)" $(OBJECTS) $(PREREQS)
else
	rm -rf "$(EXE)" "$(DSYM)" $(OBJECTS) $(PREREQS) $(DYLIB_OBJECTS) $(DYLIB_FILENAME) $(DYLIB_FILENAME).dSYM
endif

#----------------------------------------------------------------------
# From http://blog.melski.net/tag/debugging-makefiles/
# 
# Usage: make print-CC print-CXX print-LD
#----------------------------------------------------------------------
print-%:
	@echo '$*=$($*)'
	@echo '  origin = $(origin $*)'
	@echo '  flavor = $(flavor $*)'
	@echo '   value = $(value  $*)'


### Local Variables: ###
### mode:makefile ###
### End: ###