在C中与多个文件一起使用Makefile

Question

I have 6 files:

guiGame.c, which include guiGame.h
guiGame.h, include minimax.h,listutils.h
minimax.c, include minimax.h
minimax.h, include listutils.h 
listutils.c, include listutils.h

I built it in Visual Studio and I need to run it on Linux. I tried to search how to build makefile for them but I didn't succeed to build something that works; there's something with the including that never works for me.

Can someone tell me what I need to write in every X:<files> line?

Thanks.

Answer 1

The basics:

SRCS = guiGame.c minimax.c listutils.c
HDRS = guiGame.h minimax.h listutils.h

PROG = guiGame
OBJS = ${SRCS:.c=.o}

DEBRIS = a.out core *~
RM_F   = rm -f

all: ${PROG}

${PROG}: ${OBJS}
    ${CC} -o $@ ${CFLAGS} ${OBJS} ${LDFLAGS} ${LDLIBS}

clean:
    ${RM_F} ${OBJS} ${PROG} ${DEBRIS}

The residual issue is getting the dependencies correct. The object files depend on the headers they include. The pessimistic but simple version is:

${OBJS}: ${HDRS}

It works, but it means that if you change guiGame.h , listutils.o will be recompiled when it otherwise need not be.

There are various tools that automate the handling of dependencies. mkdep and mkdepend are two; you can also investigate the options to gcc .

Note that the command lines (starting ${CC} and ${RM_F} ) are indented by tabs, not spaces. This is crucial.

The variable LDFLAGS is for specifying library locations (primarily). The variable LDLIBS allows you to specify the libraries. Object files go before libraries on the command line; the library flags can be placed anywhere.

I normally build CFLAGS from various parts:

WFLAG1 = -Wall
WFLAG2 = -Wextra
WFLAG3 = -Wmissing-prototypes
WFLAG4 = -Wstrict-prototypes
WFLAG5 = -Wold-style-definition
WFLAG6 = -Werror
WFLAGS = ${WFLAG1} ${WFLAG2} ${WFLAG3} ${WFLAG4} ${WFLAG5} ${WFLAG6}
SFLAGS = -std=c11
GFLAGS = -g
OFLAGS = -O3
UFLAGS = # Set on command line
IFLAG1 = -I${HOME}/inc
IFLAGS = ${IFLAG1}

CFLAGS  = ${OFLAGS} ${GFLAGS} ${IFLAGS} ${SFLAGS} ${WFLAGS} ${UFLAGS}

This allows me to adjust any option on the make command line. Most people aren't so fussy (careful?). Note that GFLAGS is historically used for flags to the SCCS get command — you might screw something up by recycling it, but you probably won't.