Path: csiph.com!eternal-september.org!feeder.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail
From: Ben Bacarisse <ben.usenet@bsb.me.uk>
Newsgroups: comp.lang.c
Subject: Re: How to compile several C files
Date: Tue, 07 Feb 2017 16:19:38 +0000
Organization: A noiseless patient Spider
Lines: 43
Message-ID: <87wpd2as85.fsf@bsb.me.uk>
References: <ddcc4bba-8f05-4537-9deb-1d5c759602f5@googlegroups.com> <87a89yca76.fsf@bsb.me.uk> <o7cpp9$o2l$1@dont-email.me>
Mime-Version: 1.0
Content-Type: text/plain
Injection-Info: mx02.eternal-september.org; posting-host="6b16403c060c76fc53ae0c0bdb247f77"; logging-data="28520"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX1/Re/IXMmYdJm9lDPK7acHboqxbDTj2v/I="
Cancel-Lock: sha1:8jXJRnVKzCepbvDr6p1lryST5aQ= sha1:D78Q8ku04MqkJSxVlkx7TWK0Uuo=
X-BSB-Auth: 1.9502ad98574966732db0.20170207161938GMT.87wpd2as85.fsf@bsb.me.uk
Xref: csiph.com comp.lang.c:103373

Richard Heathfield <rjh@cpax.org.uk> writes:

> On 07/02/17 15:06, Ben Bacarisse wrote:
>> Once I have two files, I write a makefile.
>
> I'm slightly lazier than that. Once I have /one/ file, I write a
> makefile.

At a pinch, you can be even lazier when there is only one file because
you might be able to get away with no makefile at all because, in an
otherwise empty directory, "make x" will compile and link x.c (if it
exists).

For me, the next stage is to put (for example)

  CFLAGS=-std=c99 -Wall -pedantic

into "makefile" and nothing else.  That lets you "make x" and/or "make
x.o" with the right flags for any C files you have in that directory
(for different "x" of course).  A very simple solution for quick
one-file tests.

> To be more precise, I'm even lazier than /that/ - I run a program to
> write the makefile on my behalf:
>
> makegen foo > Makefile

Since that is (I think) your own program, it is probably more helpful to
know about "gcc -MM *.c".  This will write out the dependencies between
files.

To finish off a simple (GNU) makefile it helps to know one magic rule:

  program: one.o two.o other.o
           gcc -o $@ $^

where $@ means the target ("program") and $^ means the dependencies
("one.o two.o three.o").  You can write it out of course, but knowing $@
and $^ makes it the same rule every time.

<snip>
-- 
Ben.