From: Jonathan Wakely <jwakely.gcc@gmail.com>
To: Jonny Grant <jg@jguk.org>
Cc: gcc-help <gcc-help@gcc.gnu.org>
Subject: Re: __attribute__ error ("message")
Date: Fri, 31 Mar 2023 22:57:42 +0100 [thread overview]
Message-ID: <CAH6eHdRw48B_LnjLpgAfcct+yVwLyMGdCmgDdsKVtA4NsPXCSw@mail.gmail.com> (raw)
In-Reply-To: <6dc16e33-647e-5bf5-4025-3e10141aaa66@jguk.org>
On Fri, 31 Mar 2023 at 22:55, Jonny Grant wrote:
>
> Hello
>
> May I check, does this attribute error output the error message usually?
> My example links fine without any warnings or errors.
>
> Maybe I am misunderstanding it. I am sharing a simple program below and godbolt trunk example.
> I only get to see the error message if I don't implement the function and get a link failure.
Are you sure about that? If you remove the definition, you should get the error:
https://godbolt.org/z/z1hjn6Yan
>
> https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#Common-Function-Attributes
>
> error ("message")
> warning ("message")
>
> If the error or warning attribute is used on a function declaration and a call to such a function is not eliminated through dead code elimination or other optimizations, an error or warning (respectively) that includes message is diagnosed.
>
>
>
> https://godbolt.org/z/n849GPTjj
>
>
> void compile_abort() __attribute__((error("compile abort")));
>
> void compile_abort()
> {
> __builtin_abort();
> }
>
> int main()
> {
> compile_abort();
> }
next prev parent reply other threads:[~2023-03-31 21:57 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-31 21:54 Jonny Grant
2023-03-31 21:57 ` Jonathan Wakely [this message]
2023-03-31 21:58 ` Xi Ruoyao
2023-03-31 22:12 ` Jonny Grant
2023-03-31 22:13 ` Xi Ruoyao
2023-04-01 16:57 ` Jonny Grant
2023-04-01 23:00 ` Jonathan Wakely
2023-04-10 23:06 ` Jonny Grant
2023-04-01 17:11 ` Warning for unsafe/insecure functions Rajeev Bansal
2023-04-01 18:50 ` Xi Ruoyao
2023-04-02 2:12 ` Rajeev Bansal
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