##################################################################
#
# FILENAME   :  Makefile
# DESCRIPT   :  A general makefile to generate an ELF or a
#                   dynamic or a static library for C/C++ project.
# AUTHOR     :  vfhky  2015.08.07
# URI        :  https://typecodes.com/cseries/cppgeneralmakefile.html
#
##################################################################

.PHONY: all clean help
all:

# Some important on-off settings. You can not be too careful about them.
DEBUG           := y
# Flag of generate a dynamic lib or a static lib: y means yes. If the target is a excutable file, it should be blank!
GEN_LIBS        := y
# Flag of generate a dynamic lib: y means yes. It should be blank unless you want to generate a dynamic lib!
GEN_DYN_LIB     := y
# The name of target bin file.Please let it be blank unless the target is a excutable file. 
EXCUTE_BIN      := 
# Name of the static lib. It should be blank unless the target is a static lib, then the GEN_LIBS is y and GEN_DYN_LIB is blank.
# STATIC_LIBS       := libsrcpbl.a
# Name of the dynamic lib. It should be blank unless the target is a dynamic lib, then the GEN_LIBS is y and GEN_DYN_LIB is y.
DYNAMIC_LIBS    := libsrcpbl.so

# Environment settings. The value of PROJECT_DIR shoule be set in the *nix system as the the absolute dir path of your project.
# PROJECT_DIR   := /home/typecodes
#CURDIR         := $(PROJECT_DIR)/src/pbl
CURDIR          := $(shell pwd)
PRG_BIN_DIR     := $(PROJECT_DIR)/bin
PRG_LIB_DIR     := $(PROJECT_DIR)/lib
PRG_INC_DIR     := $(PROJECT_DIR)/include

# Cross compile tools defined. You needn't modify these vars below generally.
AS      := as
LD      := ld
CC      := gcc
CXX     := g++
CPP     := $(CC) -E
AR      := ar rcs
NM      := nm
STRIP   := strip
RANLIB  := ranlib
STD_OPT := -std=c99 -D_GNU_SOURCE 
CC      += $(STD_OPT)
CXX     += $(STD_OPT)

# *nix system tools defined. You needn't modify these vars below generally.
CP      := cp
SED     := sed
FIND    := find
MKDIR   := mkdir -p
XARGS   := xargs
MV      := mv
RM      := rm -rf


# Get .c, .cpp source files by searching from current directory.
CUR_SRC_DIR = $(shell ls -AxR $(CURDIR)|grep ":"|tr -d ':')
CUR_SRC     := $(foreach subdir,$(CUR_SRC_DIR),$(wildcard $(subdir)/*.c $(subdir)/*.cpp))
#CUR_SRC    := $(shell find . -name "*.c" -o -name "*.cpp"|sed -e 's,./,,')
CUR_C       := $(filter %.c, $(CUR_SRC))
CUR_CPP     := $(filter %.cpp, $(CUR_SRC))

# Get the include files, object files, dependent files by searching from PRG_INC_DIR.
CUR_INC_DIR = $(shell ls -AxR $(PRG_INC_DIR)|grep ":"|tr -d ':')
CUR_INC     := $(foreach subdir,$(CUR_INC_DIR),$(subdir)/*.h)
SRC_H       := $(filter %.h, $(CUR_INC))
#CUR_OBJ    := $(addprefix $(PRG_BIN_DIR)/,$(strip $(CUR_CPP:.cpp=.o) $(CUR_C:.c=.o)))
#CUR_OBJ    := $(addprefix $(PRG_BIN_DIR)/,$(notdir $(CUR_CPP:.cpp=.o) $(CUR_C:.c=.o)))
CUR_OBJ     := $(strip $(CUR_CPP:.cpp=.o) $(CUR_C:.c=.o))
#CUR_DEP    := $(addprefix $(PRG_BIN_DIR)/,$(notdir $(CUR_CPP:.cpp=.d) $(CUR_C:.c=.d)))
CUR_DEP     := $(strip $(CUR_CPP:.cpp=.d) $(CUR_C:.c=.d))

# Create directory in the header files, bin and library directory.
$(foreach dirname,$(sort $(PRG_INC_DIR) $(PRG_BIN_DIR) $(PRG_LIB_DIR)),\
  $(shell $(MKDIR) $(dirname)))

# Complie and link variables. LD_LIBS means the dynamic or static library needed for the object file.
CFLAGS      := $(if $(DEBUG),-g -Wall, -O2 -Wall)
CFLAGS      += $(if $(GEN_DYN_LIB), $(addprefix -fPIC -I ,$(sort $(dir $(SRC_H)))), $(addprefix -I ,$(sort $(dir $(SRC_H)))))
CXXFLAGS    = $(CFLAGS)
LDFLAGS     := 
LD_LIB_DIR  := #-L $(PRG_LIB_DIR)
LD_LIBS     := #-lsrcpbl -lmysqlclient
XLD_FLG     := -Xlinker "-(" $(LDFLAGS) -Xlinker "-)"

# Add vpath.
vpath %.h $(sort $(dir $(SRC_H)))
vpath %.c $(sort $(dir $(CUR_C)))
vpath %.cpp $(sort $(dir $(CUR_CPP)))

# Generate depend files.
ifneq "$(MAKECMDGOALS)" "clean"
sinclude $(CUR_DEP)
endif

# Gen_depend(depend-file,source-file,object-file,cc). This command-package is used to generate a depend file with a postfix of .d.
define gen_depend
  @set -e;                                      \
  $(RM) $1;                                     \
  $4 $(CFLAGS) -MM $2 |                         \
  $(SED) 's,\($(notdir $3)\): ,$3: ,' > $1.tmp; \
  $(SED) -e 's/#.*//'                           \
         -e 's/^[^:]*: *//'                     \
         -e 's/ *\\$$//'                        \
         -e '/^$$/ d'                           \
         -e 's/$$/ :/' < $1.tmp >> $1.tmp;      \
  $(MV) $1.tmp $1;
endef

# Rules to generate objects file(.o) from .c or .cpp files.
$(CURDIR)/%.o: %.c
    @$(call gen_depend,$(patsubst %.o,%.d,$@),$<,$@,$(CC))
    $(CC) $(CFLAGS) -o $@ -c $<

$(CURDIR)/%.o: %.cpp
    @$(call gen_depend,$(patsubst %.o,%.d,$@),$<,$@,$(CXX))
    $(CXX) $(CXXFLAGS) -o $@ -c $<

# Gen_excbin(target,CUR_OBJ,cc). This command-package is used to generate a excutable file.
define gen_excbin
  ULT_BIN += $(PRG_BIN_DIR)/$1
  $(PRG_BIN_DIR)/$1: $2
    $3 $(LDFLAGS) $$^ $(LD_LIB_DIR) $(LD_LIBS) $(XLD_FLG) -o $$@
endef

# Gen_libs(libs,CUR_OBJ,cc). This command-package is used to generate a dynamic lib or a static lib.
define gen_libs
  ULT_LIBS += $(PRG_LIB_DIR)/$1
  $(PRG_LIB_DIR)/$1: $2
    $3 $(if $(GEN_DYN_LIB),-shared $$^ $(CXXFLAGS) $(LD_LIB_DIR) $(LD_LIBS) $(XLD_FLG) -o $$@,$$@ $$^)
endef

# Call gen_excbin to generate a excutale file.
$(foreach bin,$(EXCUTE_BIN),$(eval $(call gen_excbin,$(bin),$(CUR_OBJ),$(CXX))))

# Call gen_libs to generate a dynamic lib.
$(foreach lib,$(DYNAMIC_LIBS),$(eval $(call gen_libs,$(lib),$(CUR_OBJ),$(CXX))))

# Call gen_libs to generate a static lib.
$(foreach lib,$(STATIC_LIBS),$(eval $(call gen_libs,$(lib),$(CUR_OBJ),$(AR))))


all: $(ULT_BIN) $(ULT_LIBS)


clean: 
    -$(FIND) $(CURDIR) -name "*.o" -o -name "*.d" | $(XARGS) $(RM)
    -$(RM) $(ULT_BIN)
    -$(RM) $(ULT_LIBS)


help:
    @echo PROJECT_DIR=[$(PROJECT_DIR)]
    @echo CURDIR=[$(CURDIR)]
    @echo PRG_BIN_DIR=[$(PRG_BIN_DIR)]
    @echo PRG_LIB_DIR=[$(PRG_LIB_DIR)]
    @echo PRG_INC_DIR=[$(PRG_INC_DIR)]
    @echo CUR_SRC_DIR=[$(CUR_SRC_DIR)]
    @echo CUR_SRC=[$(CUR_SRC)]
    @echo CUR_C=[$(CUR_C)]
    @echo CUR_CPP=[$(CUR_CPP)]
    @echo CUR_OBJ=[$(CUR_OBJ)]
    @echo CUR_DEP=[$(CUR_DEP)]
    @echo STD_OPT=[$(STD_OPT)]
    @echo CFLAGS=[$(CFLAGS)]
    @echo STATIC_LIBS=[$(STATIC_LIBS)]
    @echo DYNAMIC_LIBS=[$(DYNAMIC_LIBS)]