GCC/clang warning for Complex integers?

GCC/clang warning for Complex integers?

[Gerd Möllmann]

Does someone know how to get a warning for using imaginary numbers like
so (typo)?

  unsigned char *data = alloc (nbytes + 1i, IGC_OBJ_STRING_DATA);

That compiles without a warning for me, and one is in for a surprise. I
can't find the compiler flag that makes that a warning or error (tried with
clang 18 and GCC 14).

Re: GCC/clang warning for Complex integers?

[Eli Zaretskii]

> From: Gerd Möllmann <gerd.moellmann@gmail.com>
> Date: Mon, 01 Jul 2024 10:40:46 +0200
> 
> Does someone know how to get a warning for using imaginary numbers like
> so (typo)?
> 
>   unsigned char *data = alloc (nbytes + 1i, IGC_OBJ_STRING_DATA);
> 
> That compiles without a warning for me, and one is in for a surprise. I
> can't find the compiler flag that makes that a warning or error (tried with
> clang 18 and GCC 14).

Try compiling with -std=c99.  (Caveat: you might get gobs of warnings
that way.)

Re: GCC/clang warning for Complex integers?

[Pip Cet]

On Monday, July 1st, 2024 at 11:55, Eli Zaretskii <eliz@gnu.org> wrote:
> > From: Gerd Möllmann gerd.moellmann@gmail.com
> 
> > Date: Mon, 01 Jul 2024 10:40:46 +0200
> > 
> > Does someone know how to get a warning for using imaginary numbers like
> > so (typo)?
> > 
> > unsigned char *data = alloc (nbytes + 1i, IGC_OBJ_STRING_DATA);
> > 
> > That compiles without a warning for me, and one is in for a surprise. I
> > can't find the compiler flag that makes that a warning or error (tried with
> > clang 18 and GCC 14).
> 
> 
> Try compiling with -std=c99. (Caveat: you might get gobs of warnings
> that way.)

That doesn't appear to work here. gcc -Wno-error=pedantic -Wpedantic does work, but causes an (easily-fixed) compilation error (I didn't know -W flags could do that!) in seccomp-filter.c, and tons of warnings about things like statement expressions:

igc.c:1917:25: warning: imaginary constants are a GCC extension
 1917 |   ssize_t count_total = 0i;
      |                         ^~

I'm using the 20240614 version of gcc 13.3.1.

Pip

Re: GCC/clang warning for Complex integers?

[Po Lu]

Pip Cet <pipcet@protonmail.com> writes:

> That doesn't appear to work here. gcc -Wno-error=pedantic -Wpedantic does work, but causes an (easily-fixed) compilation error (I didn't know -W flags could do that!) in seccomp-filter.c, and tons of warnings about things like statement expressions:
>
> igc.c:1917:25: warning: imaginary constants are a GCC extension
>  1917 |   ssize_t count_total = 0i;
>       |                         ^~

This is a preprocessor warning, IIRC, only activated when -Wpedantic.

Re: GCC/clang warning for Complex integers?

[Gerd Möllmann]

Po Lu <luangruo@yahoo.com> writes:

> Pip Cet <pipcet@protonmail.com> writes:
>
>> That doesn't appear to work here. gcc -Wno-error=pedantic -Wpedantic does work, but causes an (easily-fixed) compilation error (I didn't know -W flags could do that!) in seccomp-filter.c, and tons of warnings about things like statement expressions:
>>
>> igc.c:1917:25: warning: imaginary constants are a GCC extension
>>  1917 |   ssize_t count_total = 0i;
>>       |                         ^~
>
> This is a preprocessor warning, IIRC, only activated when -Wpedantic.

This seems to work, at least for clang 18. Didn't try GCC further
because it can't build Emacs on macOS:

  CFLAGS = -Wgnu-imaginary-constant -g -O0

Gemini said something like that doesn't exist, the source code
disagreed :-).