#
#             LUFA Library
#     Copyright (C) Dean Camera, 2012.
#
#  dean [at] fourwalledcubicle [dot] com
#           www.lufa-lib.org
#

LUFA_BUILD_MODULES        += BUILD
LUFA_BUILD_TARGETS        += size symbol-sizes all elf hex lss clean
LUFA_BUILD_MANDATORY_VARS += TARGET ARCH MCU SRC F_USB LUFA_PATH
LUFA_BUILD_OPTIONAL_VARS  += BOARD OPTIMIZATION C_STANDARD CPP_STANDARD F_CPU C_FLAGS CPP_FLAGS ASM_FLAGS CC_FLAGS LD_FLAGS

# -----------------------------------------------------------------------------
#               LUFA GCC Compiler Buildsystem Makefile Module.
# -----------------------------------------------------------------------------
# DESCRIPTION:
#   Provides a set of targets to build a C, C++ and/or Assembly application
#   via the AVR-GCC compiler.
# -----------------------------------------------------------------------------
# TARGETS:
#
#    size                      - List built application size
#    symbol-sizes              - Print application symbols from the binary ELF
#                                file as a list sorted by size in bytes
#    all                       - Build application and list size
#    elf                       - Build application ELF debug object file
#    hex                       - Build application HEX object files
#    lss                       - Build application LSS assembly listing file
#    clean                     - Remove output files
#
# MANDATORY PARAMETERS:
#
#    TARGET                    - Application name
#    ARCH                      - Device architecture name
#    MCU                       - Microcontroller device model name
#    SRC                       - List of input source files (*.c, *.cpp, *.S)
#    F_USB                     - Speed of the input clock of the USB controller
#                                in Hz
#    LUFA_PATH                 - Path to the LUFA library core
#
# OPTIONAL PARAMETERS:
#
#    BOARD                     - LUFA board hardware
#    OPTIMIZATION              - Optimization level
#    C_STANDARD                - C Language Standard to use
#    CPP_STANDARD              - C++ Language Standard to use
#    F_CPU                     - Speed of the CPU, in Hz
#    C_FLAGS                   - Flags to pass to the C compiler only
#    CPP_FLAGS                 - Flags to pass to the C++ compiler only
#    ASM_FLAGS                 - Flags to pass to the assembler only
#    CC_FLAGS                  - Common flags to pass to the C/C++ compiler and
#                                assembler
#    LD_FLAGS                  - Flags to pass to the linker
#
# -----------------------------------------------------------------------------

ERROR_IF_UNSET     = $(if $(filter undefined, $(origin $(strip $(1)))), $(error Makefile $(strip $(1)) value not set))
ERROR_IF_EMPTY     = $(if $(strip $($(strip $(1)))), , $(error Makefile $(strip $(1)) option cannot be blank))
ERROR_IF_NONBOOL   = $(if $(filter Y N, $($(strip $(1)))), , $(error Makefile $(strip $(1)) option must be Y or N))

# Default values of optionally user-supplied variables
BOARD           ?= NONE
OPTIMIZATION    ?= s
F_CPU           ?=
C_STANDARD      ?= gnu99
CPP_STANDARD    ?= gnu++98
C_FLAGS         ?=
CPP_FLAGS       ?=
ASM_FLAGS       ?=
CC_FLAGS        ?=

# Sanity check user supplied values
$(foreach MANDATORY_VAR, $(LUFA_BUILD_MANDATORY_VARS), $(call ERROR_IF_UNSET, $(MANDATORY_VAR)))
$(call ERROR_IF_EMPTY, MCU)
$(call ERROR_IF_EMPTY, TARGET)
$(call ERROR_IF_EMPTY, ARCH)
$(call ERROR_IF_EMPTY, F_USB)
$(call ERROR_IF_EMPTY, LUFA_PATH)
$(call ERROR_IF_EMPTY, BOARD)
$(call ERROR_IF_EMPTY, OPTIMIZATION)
$(call ERROR_IF_EMPTY, C_STANDARD)
$(call ERROR_IF_EMPTY, CPP_STANDARD)

# Determine the utility prefix to use for the selected architecture
ifeq ($(ARCH), AVR8)
   CROSS        := avr-
else ifeq ($(ARCH), XMEGA)
   CROSS        := avr-
else ifeq ($(ARCH), UC3)
   CROSS        := avr32-
else
    $(error Unsupported architecture "$(ARCH)".)
endif

# Output Messages
MSG_BUILD_BEGIN  := Begin compilation of project \"$(TARGET)\"...
MSG_BUILD_END    := Finished building project \"$(TARGET)\".
MSG_COMPILE_CMD  := ' [CC]      :'
MSG_ASSEMBLE_CMD := ' [AS]      :'
MSG_NM_CMD       := ' [NM]      :'
MSG_REMOVE_CMD   := ' [RM]      :'
MSG_LINKER_CMD   := ' [LNK]     :'
MSG_SIZE_CMD     := ' [SIZE]    :'
MSG_OBJCPY_CMD   := ' [OBJCPY]  :'
MSG_OBJDMP_CMD   := ' [OBJDMP]  :'

# Convert input source file list to differentiate them by type
C_SOURCE   = $(filter %.c, $(SRC))
CPP_SOURCE = $(filter %.cpp, $(SRC))
ASM_SOURCE = $(filter %.S, $(SRC))

# Create a list of unknown source file types, if any are found throw an error
UNKNOWN_SOURCE = $(filter-out $(C_SOURCE) $(CPP_SOURCE) $(ASM_SOURCE), $(SRC))
ifneq ($(UNKNOWN_SOURCE),)
   $(error Unknown input source formats: $(UNKNOWN_SOURCE))
endif

# Convert input source filenames into a list of required output object files
OBJECT_FILES     = $(filter %.o, $(C_SOURCE:%.c=%.o) $(CPP_SOURCE:%.cpp=%.o) $(ASM_SOURCE:%.S=%.o))
DEPENDENCY_FILES = $(OBJECT_FILES:%.o=%.d)

# Create a list of common flags to pass to the compiler/linker/assembler
BASE_CC_FLAGS    := 
ifeq ($(ARCH), AVR8)
   BASE_CC_FLAGS += -mmcu=$(MCU) -gdwarf-2 -fshort-enums -fno-inline-small-functions -fpack-struct
else ifeq ($(ARCH), XMEGA)
   BASE_CC_FLAGS += -mmcu=$(MCU) -gdwarf-2 -fshort-enums -fno-inline-small-functions -fpack-struct
else ifeq ($(ARCH), UC3)
   BASE_CC_FLAGS += -mpart=$(MCU:at32%=%) -g3 -masm-addr-pseudos
endif
BASE_CC_FLAGS += -Wall -fno-strict-aliasing -funsigned-char -funsigned-bitfields -ffunction-sections
BASE_CC_FLAGS += -I. -I$(patsubst %/,%,$(LUFA_PATH))/..
BASE_CC_FLAGS += -DARCH=ARCH_$(ARCH) -DBOARD=BOARD_$(BOARD) -DF_USB=$(F_USB)UL
ifneq ($(F_CPU),)
   BASE_CC_FLAGS += -DF_CPU=$(F_CPU)UL
endif

# Additional language specific compiler flags
BASE_C_FLAGS   := -x c -O$(OPTIMIZATION) -std=$(C_STANDARD) -Wstrict-prototypes
BASE_CPP_FLAGS := -x c++ -O$(OPTIMIZATION) -std=$(CPP_STANDARD)
BASE_ASM_FLAGS := -x assembler-with-cpp

# Create a list of flags to pass to the linker
BASE_LD_FLAGS := -lm -Wl,-Map=$(TARGET).map,--cref -Wl,--gc-sections 
ifeq ($(ARCH), UC3)
   BASE_LD_FLAGS += --rodata-writable --direct-data   
else
   BASE_LD_FLAGS += -Wl,--relax
endif

# Determine flags to pass to the size utility based on its reported features
SIZE_MCU_FLAG    := $(shell $(CROSS)size --help | grep -- --mcu > /dev/null && echo --mcu=$(MCU) )
SIZE_FORMAT_FLAG := $(shell $(CROSS)size --help | grep -- --format=.*avr > /dev/null && echo --format=avr )


begin:
	@echo ""
	@echo $(MSG_BUILD_BEGIN)
	@echo ""
	
end:
	@echo ""
	@echo $(MSG_BUILD_END)
	@echo ""

gcc_version:
	@$(CROSS)gcc --version

check_source:
	@for f in $(SRC); do \
		if [ ! -f $$f ]; then \
			echo "Error: Source file not found: $$f"; \
			exit 1; \
		fi; \
	 done

size: $(TARGET).elf
	@echo $(MSG_SIZE_CMD) Determining size of \"$<\"
	@if test -f $(TARGET).elf; then \
	    $(CROSS)size $(SIZE_MCU_FLAG) $(SIZE_FORMAT_FLAG) $< ; 2>/dev/null; \
	 fi

symbol-sizes: $(TARGET).elf
	@echo $(MSG_NM_CMD) Extracting \"$<\" symbols with decimal byte sizes
	avr-nm --size-sort --demangle --radix=d $<

clean:
	@echo $(MSG_REMOVE_CMD) Removing object files of \"$(TARGET)\"
	rm -f $(OBJECT_FILES)
	@echo $(MSG_REMOVE_CMD) Removing dependency files of \"$(TARGET)\"
	rm -f $(DEPENDENCY_FILES)
	@echo $(MSG_REMOVE_CMD) Removing output files of \"$(TARGET)\"
	rm -f $(TARGET).elf $(TARGET).hex $(TARGET).eep $(TARGET).map $(TARGET).lss

all: begin check_source gcc_version elf hex lss size end

elf: $(TARGET).elf
hex: $(TARGET).hex $(TARGET).eep
lss: $(TARGET).lss

%.o: %.c $(MAKEFILE_LIST)
	@echo $(MSG_COMPILE_CMD) Compiling C file \"$<\"
	$(CROSS)gcc -c $(BASE_CC_FLAGS) $(BASE_C_FLAGS) $(CC_FLAGS) $(C_FLAGS) -MMD -MP -MF $(@:%.o=%.d) $< -o $@

%.o: %.cpp $(MAKEFILE_LIST)
	@echo $(MSG_COMPILE_CMD) Compiling C++ file \"$<\"
	$(CROSS)gcc -c $(BASE_CC_FLAGS) $(BASE_CPP_FLAGS) $(CC_FLAGS) $(CPP_FLAGS) -MMD -MP -MF $(@:%.o=%.d) $< -o $@
	
%.o: %.S $(MAKEFILE_LIST)
	@echo $(MSG_ASSEMBLE_CMD) Assembling \"$<\"
	$(CROSS)gcc -c $(BASE_CC_FLAGS) $(BASE_ASM_FLAGS) $(CC_FLAGS) $(ASM_FLAGS) $< -o $@

.PRECIOUS : $(OBJECT_FILES)
%.elf: $(OBJECT_FILES)
	@echo $(MSG_LINKER_CMD) Linking object files into \"$@\"
	$(CROSS)gcc $(BASE_CC_FLAGS) $(BASE_LD_FLAGS) $(CC_FLAGS) $(LD_FLAGS) $^ -o $@

%.hex: %.elf
	@echo $(MSG_OBJCPY_CMD) Extracting HEX file data from \"$<\"
	$(CROSS)objcopy -O ihex -R .eeprom -R .fuse -R .lock -R .signature $< $@

%.eep: %.elf
	@echo $(MSG_OBJCPY_CMD) Extracting EEP file data from \"$<\"
	$(CROSS)objcopy -j .eeprom --set-section-flags=.eeprom="alloc,load" --change-section-lma .eeprom=0 --no-change-warnings -O ihex $< $@ || exit 0

%.lss: %.elf
	@echo $(MSG_OBJDMP_CMD) Extracting LSS file data from \"$<\"
	$(CROSS)objdump -h -S -z $< > $@

# Include build dependency files
-include $(DEPENDENCY_FILES)

# Phony build targets for this module
.PHONY: begin end gcc_version check_source size symbol-sizes elf hex lss clean