#-------------------------------------------------------------------------------
# Makefile  for EIVE OBSW
#-------------------------------------------------------------------------------
#		User-modifiable options
#-------------------------------------------------------------------------------
# Fundamentals on the build process of C/C++ Software:
# https://www3.ntu.edu.sg/home/ehchua/programming/cpp/gcc_make.html

# Make documentation: https://www.gnu.org/software/make/manual/make.pdf
# Online: https://www.gnu.org/software/make/manual/make.html
# General rules: http://make.mad-scientist.net/papers/rules-of-makefiles/#rule3
SHELL = /bin/sh

# Chip & board used for compilation
# (can be overriden by adding CHIP=chip and BOARD=board to the command-line)
BOARD_FILE_ROOT = bsp_linux
BOARD = linux
OS_FSFW = linux
CUSTOM_DEFINES += -D$(OS_FSFW)
CUSTOM_DEFINES += -DLINUX

# General folder paths
FRAMEWORK_PATH = fsfw
MISSION_PATH = mission
CONFIG_PATH = fsfwconfig
TEST_PATH = test
UNITTEST_PATH = unittest

# Board specific paths
BSP_PATH = $(BOARD_FILE_ROOT)
BOARDTEST_PATH = $(BOARD_FILE_ROOT)/boardtest

# Output file basename
BASENAME = eiveobsw
BINARY_NAME = $(BASENAME)-$(BOARD)
# Output files will be put in this directory inside
OUTPUT_FOLDER = $(OS_FSFW)

# Default debug output
DEBUG_LEVEL = -g3

# Optimization level. -O0 default, -Os for size, -O3 for speed and size.
OPTIMIZATION = -O0

ifdef GCOV
CUSTOM_DEFINES += -DGCOV
endif

# Output directories
BUILDPATH = _bin
DEPENDPATH = _dep
OBJECTPATH = _obj
ifeq ($(MAKECMDGOALS), release)
BUILD_FOLDER = mission
else 
BUILD_FOLDER = devel
endif

DEPENDDIR = $(DEPENDPATH)/$(OUTPUT_FOLDER)/$(BUILD_FOLDER)
OBJDIR = $(OBJECTPATH)/$(OUTPUT_FOLDER)/$(BUILD_FOLDER)
BINDIR = $(BUILDPATH)/$(OUTPUT_FOLDER)/$(BUILD_FOLDER)

CLEANDEP = $(DEPENDPATH)/$(OUTPUT_FOLDER)
CLEANOBJ = $(OBJECTPATH)/$(OUTPUT_FOLDER)
CLEANBIN1 = $(BUILDPATH)/$(OUTPUT_FOLDER)/mission
CLEANBIN2 = $(BUILDPATH)/$(OUTPUT_FOLDER)/devel

#-------------------------------------------------------------------------------
#		Tools and Includes
#-------------------------------------------------------------------------------

# Tool suffix when cross-compiling
ifdef HOST_LINUX
CROSS_COMPILE = 
else
CROSS_COMPILE = arm-linux-gnueabihf-
endif

ifdef WINDOWS
# C Compiler
CC = $(CROSS_COMPILE)gcc.exe

# C++ compiler
CXX = $(CROSS_COMPILE)g++.exe

# Additional Tools
SIZE = $(CROSS_COMPILE)size.exe
STRIP = $(CROSS_COMPILE)strip.exe
CP = $(CROSS_COMPILE)objcopy.exe
else
# C Compiler
CC = $(CROSS_COMPILE)gcc

# C++ compiler
CXX = $(CROSS_COMPILE)g++

# Additional Tools
SIZE = $(CROSS_COMPILE)size
STRIP = $(CROSS_COMPILE)strip
CP = $(CROSS_COMPILE)objcopy
endif

HEXCOPY = $(CP) -O ihex
BINCOPY = $(CP) -O binary
# files to be compiled, will be filled in by include makefiles
# := assignment here is neccessary as initialization so that the +=
# operator can be used in the submakefiles to achieve immediate evaluation. 
# See: http://make.mad-scientist.net/evaluation-and-expansion/
CSRC := 
CXXSRC := 
ASRC := 
INCLUDES := 

# Directories where $(directoryname).mk files should be included from
SUBDIRS := $(FRAMEWORK_PATH) $(TEST_PATH) $(BSP_PATH) $(UNITTEST_PATH)\
		   $(CONFIG_PATH) $(MISSION_PATH)
# INCLUDES += framework/test/catch2

# ETL library include.
ETL_PATH = etl/include
I_INCLUDES += -I$(ETL_PATH)

I_INCLUDES += $(addprefix -I, $(INCLUDES))

# This is a hack from http://make.mad-scientist.net/the-eval-function/
#
# The problem is, that included makefiles should be aware of their relative path
# but not need to guess or hardcode it. So we set $(CURRENTPATH) for them. If
# we do this globally and the included makefiles want to include other makefiles as
# well, they would overwrite $(CURRENTPATH), screwing the include after them.
#
# By using a for-loop with an eval'd macro, we can generate the code to include all
# sub-makefiles (with the correct $(CURRENTPATH) set) before actually evaluating
# (and by this possibly changing $(CURRENTPATH)) them.
#
# This works recursively, if an included makefile wants to include, it can safely set 
# $(SUBDIRS) (which has already been evaluated here) and do
# "$(foreach S,$(SUBDIRS),$(eval $(INCLUDE_FILE)))"
# $(SUBDIRS) must be relative to the project root, so to include subdir foo, set
# $(SUBDIRS) = $(CURRENTPATH)/foo.
define INCLUDE_FILE
CURRENTPATH := $S
include $(S)/$(notdir $S).mk
endef
$(foreach S,$(SUBDIRS),$(eval $(INCLUDE_FILE)))


#-------------------------------------------------------------------------------
#		Source Files
#-------------------------------------------------------------------------------
# Additional source files which were not includes by other .mk
# files are added here.
# To help Makefile find source files, the source location paths
# can be added by using the VPATH variable
# See: https://www.gnu.org/software/make/manual/html_node/General-Search.html
# It is recommended to only use VPATH to add source locations
# See: http://make.mad-scientist.net/papers/how-not-to-use-vpath/

# Please ensure that no files are included by both .mk file and here !

# All C Sources included by .mk files are assigned here
# Add the objects to sources so dependency handling works
C_OBJECTS += $(CSRC:.c=.o)

# Objects built from Assembly source files
ASM_OBJECTS = $(ASRC:.S=.o)

# Objects built from C++ source files
CXX_OBJECTS +=  $(CXXSRC:.cpp=.o)

#-------------------------------------------------------------------------------
#		Build Configuration + Output
#-------------------------------------------------------------------------------

TARGET = Debug
DEBUG_MESSAGE = Off
OPTIMIZATION_MESSAGE = Off

# Define Messages
MSG_INFO = Software: EIVE OBSW Linux.
MSG_LINKING = Linking:
MSG_COMPILING = Compiling:
MSG_ASSEMBLING = Assembling:
MSG_BINARY = Generate binary: 
MSG_OPTIMIZATION = Optimization: $(OPTIMIZATION), $(OPTIMIZATION_MESSAGE)
MSG_TARGET = Target Build: $(TARGET)
MSG_DEBUG = FSFW Debugging: $(DEBUG_MESSAGE)
MSG_COMIF = TMTC Communication Interface: $(COMIF_MESSAGE)
 
# See: https://stackoverflow.com/questions/6687630/how-to-remove-unused-c-c-symbols-with-gcc-and-ld
# Used to throw away unused code. Reduces code size significantly !
# -Wl,--gc-sections: needs to be passed to the linker to throw aways unused code
ifdef KEEP_UNUSED_CODE
PROTOTYPE_OPTIMIZATION = 
DEAD_CODE_REMOVAL = 
else
PROTOTYPE_OPTIMIZATION = -ffunction-sections -fdata-sections
DEAD_CODE_REMOVAL = -Wl,--gc-sections
# Link time optimization
# See https://gcc.gnu.org/onlinedocs/gcc/Optimize-Options.html for reference
# Link time is larger and size of object files can not be retrieved
# but resulting binary is smaller. Could be used in mission/deployment build
# Requires -ffunction-section in linker call
LINK_TIME_OPTIMIZATION = -flto
OPTIMIZATION += $(PROTOTYPE_OPTIMIZATION) 
endif 

# Dependency Flags
# These flags tell the compiler to build dependencies
# See: https://www.gnu.org/software/make/manual/html_node/Automatic-Prerequisites.html
# Using following guide: 
# http://make.mad-scientist.net/papers/advanced-auto-dependency-generation/
DEPFLAGS = -MT $@ -MMD -MP -MF $(DEPENDDIR)/$*.d

# Flags for the compiler call
# - std: Which C++ version to use. Common versions: c++11, c++14 and c++17
# - Wall: enable all warnings
# - Wextra: enable extra warnings
# - g: defines debug level
# - fmessage-length: to control the formatting algorithm for diagnostic messages;
#    =0 means  no line-wrapping is done; each error message appears on a single line
# - fno-exceptions: stops generating extra code needed to propagate exceptions, 
#    which can produce significant data size overhead
WARNING_FLAGS =  -Wall -Wshadow=local -Wextra -Wimplicit-fallthrough=1 \
		-Wno-unused-parameter 

CXXDEFINES := $(CUSTOM_DEFINES)
CFLAGS += 
CXXFLAGS += -I. $(DEBUG_LEVEL) $(OPTIMIZATION) $(DEPFLAGS) $(WARNING_FLAGS) \
		$(I_INCLUDES) -fmessage-length=0 $(CXXDEFINES) 
CPPFLAGS += -std=c++17 -fno-exceptions
ASFLAGS = -Wall $(DEBUG_LEVEL) $(OPTIMIZATION) $(I_INCLUDES) -D__ASSEMBLY__

# Flags for the linker call
# LINK_INCLUDES specify the path to used libraries and the linker script
# LINK_LIBRARIES link HCC and HAL library and enable float support
LINK_FLAGS = $(DEBUG_LEVEL) $(DEAD_CODE_REMOVAL) $(OPTIMIZATION) -pthread 
LINK_INCLUDES = 
LINK_LIBRARIES = -lrt

# Gnu Coverage Tools Flags
ifdef GCOV
GCOV_CXXFLAGS = -fprofile-arcs -ftest-coverage
CXXFLAGS += $(GCOV_CXXFLAGS)
GCOV_LINKER_LIBS = -lgcov -fprofile-arcs -ftest-coverage
LINK_LIBRARIES += $(GCOV_LINKER_LIBS)
endif

#-------------------------------------------------------------------------------
#		Rules
#-------------------------------------------------------------------------------
# Makefile rules: https://www.gnu.org/software/make/manual/html_node/Rules.html
# This is the primary section which defines the ruleset to build
# the executable from the sources.

default: all

# In this section, the binaries are built for all selected memories

all: executable 
	
# Cleans all files 
hardclean: 
	-rm -rf $(BUILDPATH)
	-rm -rf $(OBJECTPATH)
	-rm -rf $(DEPENDPATH)

# Only clean files for current build
clean:
	@echo $(DEPFILES)
	-rm -rf $(CLEANOBJ)
	-rm -rf $(CLEANBIN)
	-rm -rf $(CLEANDEP)

# Only clean binaries. Useful for changing the binary type when object files 
# are already compiled so complete rebuild is not necessary
cleanbin:
	-rm -rf $(BUILDPATH)/$(OUTPUT_FOLDER)
	
# Build target configuration
release: OPTIMIZATION = -O2 $(PROTOTYPE_OPTIMIZATION) $(LINK_TIME_OPTIMIZATION)
release: LINK_TIME_OPTIMIZATION = -flto
release: TARGET = Release
release: OPTIMIZATION_MESSAGE = On with Link Time Optimization
release: DEBUG_LEVEL = -g0

debug: CXXDEFINES += -DDEBUG
debug: DEBUG_MESSAGE = On

debug release: executable
	
executable: $(BINDIR)/$(BINARY_NAME).elf
	@echo
	@echo $(MSG_INFO)
	@echo $(MSG_TARGET)
	@echo $(MSG_OPTIMIZATION)
	@echo $(MSG_DEBUG)

# For debugging.
# $(info $${C_OBJECTS} is [${C_OBJECTS}])	
# $(info $${CXX_OBJECTS} is [${CXX_OBJECTS}])	

C_OBJECTS_PREFIXED = $(addprefix $(OBJDIR)/, $(C_OBJECTS))
CXX_OBJECTS_PREFIXED = $(addprefix $(OBJDIR)/, $(CXX_OBJECTS))
ASM_OBJECTS_PREFIXED = $(addprefix $(OBJDIR)/, $(ASM_OBJECTS))
ALL_OBJECTS_PREFIXED = $(ASM_OBJECTS_PREFIXED) $(C_OBJECTS_PREFIXED) \
					   $(CXX_OBJECTS_PREFIXED) 

# Useful for debugging the Makefile
# Also see: https://www.oreilly.com/openbook/make3/book/ch12.pdf
# $$(info $${ALL_OBJECTS_PREFIXED} is [${ALL_OBJECTS_PREFIXED}])

# Automatic variables are used here extensively. Some of them
# are escaped($$) to suppress immediate evaluation. The most important ones are:
# $@: Name of Target (left side of rule)
# $<: Name of the first prerequisite (right side of rule)
# @^: List of all prerequisite, omitting duplicates
# @D: Directory and file-within-directory part of $@

# Generates binary and displays all build properties
# -p with mkdir ignores error and creates directory when needed.

# SHOW_DETAILS = 1

$(BINDIR)/$(BINARY_NAME).elf: $(ALL_OBJECTS_PREFIXED)
	@echo $(MSG_LINKING) Target $@
	@mkdir -p $(@D)
ifdef SHOW_DETAILS
	$(CXX) $(LINK_FLAGS) $(LINK_INCLUDES) -o $@ $^ $(LINK_LIBRARIES)
else
	@$(CXX) $(LINK_FLAGS) $(LINK_INCLUDES) -o $@ $^ $(LINK_LIBRARIES)
endif
ifeq ($(BUILD_FOLDER), release)
# With Link Time Optimization, section size is not available
	$(SIZE) $@
else
	@$(SIZE) $^ $@
endif


$(OBJDIR)/%.o: %.cpp
$(OBJDIR)/%.o: %.cpp $(DEPENDDIR)/%.d | $(DEPENDDIR)
	@echo $(I_INCLUDES)
	@echo 
	@echo $(MSG_COMPILING) $<
	@mkdir -p $(@D)
ifdef SHOW_DETAILS
	$(CXX) $(CXXFLAGS) $(CPPFLAGS) -c -o $@ $<
else
	@$(CXX) $(CXXFLAGS) $(CPPFLAGS) -c -o $@ $<
endif


$(OBJDIR)/%.o: %.c 
$(OBJDIR)/%.o: %.c $(DEPENDDIR)/%.d | $(DEPENDDIR) 
	@echo 
	@echo $(MSG_COMPILING) $<
	@mkdir -p $(@D)
ifdef SHOW_DETAILS
	$(CC) $(CXXFLAGS) $(CFLAGS) -c -o $@ $<
else
	@$(CC) $(CXXFLAGS) $(CFLAGS) -c -o $@ $<
endif


#-------------------------------------------------------------------------------
#		Dependency Handling
#-------------------------------------------------------------------------------

# Dependency Handling according to following guide:
# http://make.mad-scientist.net/papers/advanced-auto-dependency-generation/
$(DEPENDDIR):
	@mkdir -p $(@D)
DEPENDENCY_RELATIVE = $(CSRC:.c=.d) $(CXXSRC:.cpp=.d)
# This is the list of all dependencies
DEPFILES = $(addprefix $(DEPENDDIR)/, $(DEPENDENCY_RELATIVE))
# Create subdirectories for dependencies
$(DEPFILES):
	@mkdir -p $(@D)
	
	
# Include all dependencies
include $(wildcard $(DEPFILES))	
	
# .PHONY tells make that these targets aren't files
.PHONY: clean sdramCfg release debug all hardclean