#-*- mode: makefile; indent-tabs-mode: t; coding: utf-8; show-trailing-whitespace: t -*-
# Makefile.global
# Copyright 2022 Angelo Rossi <angelo.rossi.homelab@gmail.com>
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# 1. Redistributions of source code must retain the above copyright notice,
#    this list of conditions and the following disclaimer.
#
# 2. Redistributions in binary form must reproduce the above copyright notice,
#    this list of conditions and the following disclaimer in the documentation
#    and/or other materials provided with the distribution.
#
# 3. Neither the name of the copyright holder nor the names of its contributors
#    may be used to endorse or promote products derived from this software
#    without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.

#
# Get the operating system name.  If this is Cygwin, the .d files will be
# munged to convert c: into /cygdrive/c so that "make" will be happy with the
# auto-generated dependencies.
#

# The command for calling the compiler.
ifeq (${shell uname},linux)
	AS=${shell which as}
	CC=${shell which gcc}
	CXX=${shell which g++}
	LD=${shell which ld}
	OBJCOPY=${shell which objcopy}
	OBJDUMP=${shell which objdump}
	AR=${shell which ar}
	NM=${shell which nm}
else
	ifeq (${shell uname},OpenBSD)
		AS=${shell which gas}
		CC=${shell which egcc}
		CXX=${shell which eg++}
		LD=${shell which ld}
		OBJCOPY=${shell which objcopy}
		OBJDUMP=${shell which objdump}
		AR=${shell which egcc-ar}
		NM=${shell which egcc-nm}
	endif
endif
LINKER=${CXX}

# The flags passed to the assembler.

AS_FLAGS=

ifdef ARCH
	AS_FLAGS+=-march=${ARCH}
endif

# The flags passed to the c compiler.

CC_FLAGS=-O0				\
	 -Wall				\
	 -std=c99			\
         -pthread                       \
	 -c

# The flags passed to the c++ compiler.

CXX_FLAGS=-O0				        \
	  -Wall				        \
	  -std=gnu++11			        \
          -pthread                              \
	  -c

ifdef WITH_OVER1
CXX_FLAGS+=-DWITH_OVER1
endif
ifdef WITH_OVER20
CXX_FLAGS+=-DWITH_OVER20
endif
ifdef WITH_OVER51
CXX_FLAGS+=-DWITH_OVER51
endif


# The flags passed to the linker.
LD_SCRIPT_FLAGS=
ifneq (${LINKER_SCRIPT},)
	LD_SCRIPT_FLAGS+=-T ${SCRIPTS_PATH}/${LINKER_SCRIPT}.lnk
endif

# Specs files.
SPECS_FILES=

ifneq (${SPECS_FILES},)
	SPECS_FLAGS=${patsubst %,--specs=%,${subst :, ,${SPECS_FILES}}}
else
	SPECS_FLAGS=
endif

LD_FLAGS=

LD_FLAGS+=-Wl,--start-group			\
          ${LD_SCRIPT_FLAGS}			\
	  ${SPECS_FLAGS}			\
	  -Wl,-Map=${TOOLCHAIN}/${TARGET}.map	\
	  -Wl,--end-group

# ar most common flags.
AR_FLAGS=-cr

# objdump most common flags.
OBJDUMP_FLAGS=	-h	\
		-EL	\
		-s	\
		-S	\
		-d

# objcopy most common flags.
OBJCOPY_FLAGS=	-S		\
		-R .data

# Get the location of libgcc.a, libc.a, libstdc++ and
# libm.a from the GCC front-end.
LIBGCC=${shell ${CC} ${CC_FLAGS} -print-libgcc-file-name}
LIBC=${shell ${CC} ${CC_FLAGS} -print-file-name=libc.a}
LIBM=${shell ${CC} ${CC_FLAGS} -print-file-name=libm.a}
LIBPTHREAD=${shell ${CC} ${CC_FLAGS} --print-file-name=libpthread.a}
LIBSTDCXX=${shell ${CXX} ${CXX_FLAGS} --print-file-name=libstdc++.a}

# Libraries to link.
LIBRARIES=pthread

# Tell the compiler to include debugging information if the DEBUG environment
# variable is set.
ifneq (${DEBUG},)
	AS_FLAGS+=-ggdb3
	CC_FLAGS+=-ggdb3 -DDEBUG
	CXX_FLAGS+=-ggdb3 -DDEBUG
	LD_FLAGS+=-ggdb3
endif

# Add the include file paths to AS_FLAGS, CC_FLAGS and CXX_FLAGS.
AS_FLAGS+=${patsubst %,-I%,${subst :, ,${INCLUDES_PATH}}}
CC_FLAGS+=${patsubst %,-I%,${subst :, ,${INCLUDES_PATH}}}
CXX_FLAGS+=${patsubst %,-I%,${subst :, ,${INCLUDES_PATH}}}

LD_FLAGS+=-pthread

ifneq (${LIBRARIES_PATH},)
LD_FLAGS+=${patsubst %,-L%,${subst :, ,${LIBRARIES_PATH}}}
endif

ifneq (${LIBRARIES},)
LD_FLAGS+=${patsubst %,-l%,${subst :, ,${LIBRARIES}}}
endif

# Rule for building the object file from each assembly source files.
${TOOLCHAIN}/%.o: %.S
	@if [ 'x${VERBOSE}' = x ];			\
	then						\
		echo " [ AS ] ${<}";			\
	else						\
		echo "${AS} ${AS_FLAGS}  ${<} -o ${@}";	\
	fi
	@${AS} ${AS_FLAGS} ${<} -o ${@}

# Rule for building the object file from each C source file.

${TOOLCHAIN}/%.o: %.c
	@if [ 'x${VERBOSE}' = x ];                      \
	 then                                           \
	     echo " [ CC ] ${<}";                       \
	 else                               		\
	     echo ${CC} ${CC_FLAGS} -o ${@} ${<}; 	\
	 fi
	@${CC} ${CC_FLAGS} -o ${@} ${<}

${TOOLCHAIN}/%.o: %.cpp
	@if [ 'x${VERBOSE}' = x ];                      \
	 then                                           \
	     echo " [ CPP ] ${<}";                      \
	 else                                           \
	     echo ${CXX} ${CXX_FLAGS} -o ${@} ${<};	\
	 fi
	@${CXX} ${CXX_FLAGS} -o ${@} ${<}

# Rule for creating an object library.
${TOOLCHAIN}/%.a:
	@if [ 'x${VERBOSE}' = x ];     		\
	 then                          		\
	     echo " [ AR ] ${@}";      		\
	 else                          		\
	     echo ${AR} ${AR_FLAGS} ${@} ${^}; 	\
	 fi
	@${AR} ${AR_FLAGS} ${@} ${^}

# Rule for linking the application.
${TOOLCHAIN}/%:
	@if [ 'x${VERBOSE}' = x ];			\
	then						\
		echo " [ LD ] ${@}";			\
	else						\
		echo ${LINKER} $(filter %.o %.a, ${^})	\
                               ${LD_FLAGS}              \
                               -o ${@};                 \
	fi
	@${LINKER} $(filter %.o %.a, ${^})      \
                   ${LD_FLAGS}                  \
                   -o ${@}

# Rule to create a .lst file.
${TOOLCHAIN}/%.lst:
	@if [ 'x${VERBOSE}' = x ];							\
	then										\
		echo " [ OBJDUMP ] ${@}";						\
	else										\
		echo "${OBJDUMP} ${OBJDUMP_FLAGS} ${TOOLCHAIN}/${TARGET} > ${@}";	\
	fi
	@${OBJDUMP} ${OBJDUMP_FLAGS} ${TOOLCHAIN}/${TARGET} > ${@}