Makefile for building C++ Google Protocol Buffers Project - c++

Question

I Just started fooling around using Google Protocol Buffers and I am trying to incorporate the C++ output files from the protocol buffer compiler into my project. I have Been using a simple makefile for my projects so far and it does the trick for building source files all sharing the same extension. I use ".cpp" for my source files but Google Protocol Buffers outputs its source as ".pb.cc" files. I need to be able to compile and link both types of source files into one executable.
I have been searching and fiddling around with my makefile for a few hours now and have had no success.
My Current Makefile:
PROGRAM_NAME=aserv
CC=gcc
CXX=g++
RM=rm -f
CPPFLAGS=-g --std=c++14 -O3 -I/usr/local/include/
LDFLAGS=-g -L/usr/local/lib -L/usr/local/lib/boost
LDLIBS= -lrtaudio -pthread -lboost_system -lprotobuf
INSTALL_DIR = /usr/local/bin/
SRCS=$(wildcard *.cpp)
OBJS=$(subst .cpp,.o,$(SRCS))
all: $(PROGRAM_NAME)
$(PROGRAM_NAME): $(OBJS)
$(CXX) $(LDFLAGS) -o $(PROGRAM_NAME) $(OBJS) $(LDLIBS)
depend: .depend
.depend: $(SRCS)
rm -f ./.depend
$(CXX) $(CPPFLAGS) -MM $^>>./.depend;
clean:
$(RM) $(OBJS) $(PROGRAM_NAME) .depend
install:
cp $(PROGRAM_NAME) $(INSTALL_DIR)$(PROGRAM_NAME)
uninstall:
$(RM) $(INSTALL_DIR)$(PROGRAM_NAME)
dist-clean: clean
$(RM) *~ .depend
include .depend
I am not too well versed in writing makefiles yet, so I just don't quite know what to do to make this work.
If it helps i have GNU make 4.1 and gcc 5.3.1 on Ubuntu 16.04 beta

Answer 1

I couldnt get your original Makefile to work so I changed a few things but I think the tricky part with this is the implicit rules that make generates to build your .o files. I think for the .pb.cc files you need to generate .pb.o objects so that the implicit rules can match them.
Try this:
PROGRAM_NAME = aserv
CC = gcc
CXX = g++
RM = rm -f
CXXFLAGS = --std=c++14 -pthread -g -O3 -MMD -MP
CPPFLAGS = -I/usr/local/include/
LDFLAGS = -L/usr/local/lib -L/usr/local/lib/boost
LDLIBS = -lrtaudio -lboost_system -lprotobuf
INSTALL_DIR = /usr/local/bin
SRCS = $(wildcard *.cpp) $(wildcard *.pb.cc)
OBJS = $(subst .pb.cc,.pb.o,$(subst .cpp,.o,$(SRCS)))
DEPS = $(subst .pb.cc,.pb.d,$(subst .cpp,.d,$(SRCS)))
all: $(PROGRAM_NAME)
$(PROGRAM_NAME): $(OBJS)
$(CXX) $(CXXFLAGS) $(CPPFLAGS) -o $# $^ $(LDFLAGS) $(LDLIBS)
-include $(DEPS)
clean:
$(RM) $(OBJS) $(PROGRAM_NAME)
install:
cp $(PROGRAM_NAME) $(INSTALL_DIR)
uninstall:
$(RM) $(INSTALL_DIR)/$(PROGRAM_NAME)
dist-clean: clean
$(RM) *~ $(DEPS)

Answer 2

If you wanto to only strictly rely on Make, and not the surrounding shell you can add another set of SRC and OBJ variables, which will serve as a second set of dependencies.
Add these right below the first set:
SRC1=$(wildcard *.pb.cc)
OBJ1=$(subst .pb.cc,.o,$(SRC1))
And change the .depend and $(PROGRAM_NAME) rule:
.depend: $(SRCS) $(SRC1)
$(PROGRAM_NAME): $(OBJS) $(OBJ1)
$(CXX) $(LDFLAGS) $^ $(LDLIBS) -o $#
%.o: %.c
$(CC) $(ALL_CFLAGS) $(ALL_CPPFLAGS) -c -o $# $<