[Bug preprocessor/60875] `_Pragma("message \"foo\")"` doesn't work in expression contexts.

[nok.raven at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60875

--- Comment #6 from Nikita Kniazev  ---
> Those pragmas are all extensions, so the standard doesn't cover them.

There was a Clang bug report recently with a pretty much same code I had posted
previously and Clang developers said that it is ill-formed with a reference to
the C11 standard https://bugs.llvm.org/show_bug.cgi?id=41514#c1

[Bug preprocessor/60875] `_Pragma("message \"foo\")"` doesn't work in expression contexts.

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60875

--- Comment #5 from Jakub Jelinek  ---
Those pragmas are all extensions, so the standard doesn't cover them.

[Bug preprocessor/60875] `_Pragma("message \"foo\")"` doesn't work in expression contexts.

[nok.raven at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60875

Nikita Kniazev  changed:

   What|Removed |Added

 CC||nok.raven at gmail dot com

--- Comment #4 from Nikita Kniazev  ---
Is this forbidden by the standard? The Clang and MSVC are fine with such pragma
usage. It really complicates warning suppression.

int main()
{
return
#pragma GCC diagnostic push
42;
}

: In function 'int main()':
:4:9: error: '#pragma' is not allowed here
4 | #pragma GCC diagnostic push
  | ^~~
:4:12: error: expected ';' before numeric constant
4 | #pragma GCC diagnostic push
  |^
  |;
5 | 42;
  | ~~ 

https://godbolt.org/z/mT1h0Z

[Bug preprocessor/60875] `_Pragma("message \"foo\")"` doesn't work in expression contexts.

[desrt at desrt dot ca]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60875

Ryan Lortie  changed:

   What|Removed |Added

 CC||desrt at desrt dot ca

--- Comment #3 from Ryan Lortie  ---
We want to do similar things in GLib in order to warn in the middle of
arbitrary expressions or statements expanded from macros (essentially: support
for deprecated macros).

[Bug preprocessor/60875] `_Pragma("message \"foo\")"` doesn't work in expression contexts.

[thakis at chromium dot org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60875

--- Comment #2 from thakis at chromium dot org ---
That only works on declarations, not in an expression, right?

(We do have a workaround that works with gcc. But "pragma message" matches the
semantics of what we want to do, and it works with MSVC and clang, so it'd be
nice if it worked in gcc too.)

[Bug preprocessor/60875] `_Pragma("message \"foo\")"` doesn't work in expression contexts.

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60875

Jakub Jelinek  changed:

   What|Removed |Added

 CC||jakub at gcc dot gnu.org

--- Comment #1 from Jakub Jelinek  ---
Use deprecated attribute instead?