So, I have a set of different libraries in C and C++ that I need to build with some common options. My current "template" makefile looks something like so:
#Change this for different MCUs. Standard includes atmega328
VARIANT = ../variants/standard
HDRS=RedBot.h
OBJS=RedBot.o RedBotAccel.o RedBotMotor.o RedBotSensor.o
CPPFLAGS = -I../arduino/ -I./ -DF_CPU=16000000UL -Os -mmcu=atmega328p
CC=avr-gcc
CPP=avr-g++
AR=avr-ar
default: libredbot.a
libredbot.a: ${OBJS}
${AR} crs libredbot.a $(OBJS)
.c.o: ${HDRS}
${CC} -I ${VARIANT} ${CFLAGS} -c $*.c
.cpp.o: ${HDRS}
${CPP} -I ${VARIANT} ${CPPFLAGS} -c $*.cpp
clean:
rm -f ${OBJS} core a.out errs *.a
I place the makefile in the same folder as all the sources. However, this is ugly for a few reasons. For one, it's only a template. I have to duplicate this across about 15 libraries. And I need for the compilation options to be very easy to change across all libraries, because multiple targets is common. Currently, the best thing I can think of is making a root makefile with the options passed to each library makefile. However, I still have to keep track of all the files (the OBJS bit). And not all libraries are capable of being built on all targets.
Can someone point me either to a more comprehensive makefile, or possibly an example build file for something like Rake that could handle this?
I ended up writing my own little hacky thing with Ruby to get this done easily. You can draw inspiration from it here: https://github.com/Earlz/make-wiring/blob/master/build.rb
Basically, it consists of a "template" makefile that takes many environment variables. And the build.rb script just passes them off to the makefile without you having to manually specify everything on the command line. Usage thus would look like so:
./build.rb build redbot
./build.rb build arduino
or whatever, and all flags and arguments are neatly contained within build.rb, instead of being spread among dozens of makefiles or being manually specified on the command line