From: Marek Polacek <polacek@redhat.com>
To: "Jiří Wolker" <woljiri@gmail.com>
Cc: gcc@gcc.gnu.org
Subject: Re: Feature request: Warning when .c file gets #include'd
Date: Fri, 2 Dec 2022 10:46:34 -0500 [thread overview]
Message-ID: <Y4od2g59tvh0aveX@redhat.com> (raw)
In-Reply-To: <87359xyhsn.fsf@gmail.com>
On Fri, Dec 02, 2022 at 03:57:44PM +0100, Jiří Wolker via Gcc wrote:
>
> Hi,
>
> I've met a guy that is learning C and got stuck when the linker produced
> a screenful of messages about that he did something define multiple
> times. The cause of the problem was trivial:
>
> He did ``#include "something.c"'' in his code.
>
> In the past, I also did this thing multiple times and I would appreciate
> a warning produced by the gcc when compiling C/C++ file that includes a
> file ending in .c, .cx, .cpp or .cxx.
>
> What do you think about that?
>
> I would prefer to make this enabled when -Wextra is used.
The problem is that a lot of beginners don't use -Wextra, so the
warning wouldn't be displayed anyway.
> Based on my past experience with using .c files in the include
> directive, I can think of these problems.
>
> - Sometimes, I want to include a file that is definitely not a header,
> but also it is not a stand-alone source file. I personally prefer
> using .inc suffix, but some people possibly terminate the file names
> with .c suffix like a source file.
>
> Example: list of enum fields included from a separate file that was
> generated by a script
>
> - In some projects, someone can deliberately want to include another
> source file. For example, this can happen when doing unit tests and
> you do not want to specify the source file name on the command line.
Indeed, e.g. elfutils uses this a lot:
#define LIBELFBITS 64
#include "elf32_xlatetom.c"
We use including .c in our testsuite a lot as well.
So I'm afraid this would get -1 from me personally, sorry.
> If you accept that, I can try to implement that. (That would be my first
> contribution to this project and I do not know gcc codebase, but it
> looks like a relatively simple change.) Do you think that it would need
> a copyright assignment?
I think it would.
Thanks,
Marek
next prev parent reply other threads:[~2022-12-02 15:46 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-02 14:57 Jiří Wolker
2022-12-02 15:46 ` Marek Polacek [this message]
2022-12-02 16:13 ` Jonathan Wakely
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