Re: preprocessing directive with no new-line character

[Vincent Lefevre <vincent+gcc at vinc17 dot org>]

On 2017-07-17 16:09:42 +0200, Mathieu Malaterre wrote:
> On Mon, Jul 17, 2017 at 3:19 PM, Vincent Lefevre <vincent+gcc@vinc17.org> wrote:
> > According to the C standard (either C99 or C11), a preprocessing
> > directive ends with a new-line character: "The last token in the
> > sequence is the first new-line character that follows the first
> > token in the sequence."
> >
> > But GCC accepts the following program with -std=c99 -pedantic:
> >
> > int main (void)
> > {
> >   return 0;
> > }
> > #define FOO
> >
> > where there is no new-line character after "FOO".
> >
> > Is there any reason?
> 
> Do you have 0x0A at the end of your text file ?

No:

zira:~> hd tst.c
00000000  69 6e 74 20 6d 61 69 6e  20 28 76 6f 69 64 29 0a  |int main (void).|
00000010  7b 0a 20 20 72 65 74 75  72 6e 20 30 3b 0a 7d 0a  |{.  return 0;.}.|
00000020  23 64 65 66 69 6e 65 20  46 4f 4f                 |#define FOO|
0000002b

And BTW, Clang behaves as expected:

zira:~> clang-4.0 -std=c99 -pedantic tst.c -o tst
tst.c:5:12: warning: no newline at end of file [-Wnewline-eof]
#define FOO
           ^
1 warning generated.

So, I think that's a bug in GCC. Do you agree?

-- 
Vincent Lefèvre <vincent@vinc17.net> - Web: <https://www.vinc17.net/>
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