[Bug c/124830] c/c-decl.cc Fails to cross compile with C++20 host compiler

[rguenth at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=124830

--- Comment #2 from Richard Biener  ---
In case it matters this is seen with glibc 2.42

[Bug c/124830] c/c-decl.cc Fails to cross compile with C++20 host compiler

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=124830

--- Comment #6 from Drea Pinski  ---
 basically INCLUDE_MEMORY, INCLUDE_MUTEX, and INCLUDE_SSTREAM all need to moved
to before the include of safe-ctype.h

GCC 15 INCLUDE_SSTREAM was handled with
r15-5661-gf6e00226a4ca63e76e3e0b3a09a4ce6223980981

and MEMORY was done with r15-5603-gb3f1b9e2aa079f (by making it uncondtional).

MUTEX is not done on the trunk though.

[Bug c/124830] c/c-decl.cc Fails to cross compile with C++20 host compiler

[rguenth at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=124830

--- Comment #3 from Richard Biener  ---
Can also be reproduced with --disable-bootstrap instead of building a cross
compiler.  When bootstrapping we force -std=c++14 during stage1 build.

[Bug c/124830] c/c-decl.cc Fails to cross compile with C++20 host compiler

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=124830

--- Comment #4 from Drea Pinski  ---
This was PR 117771 which was only fixed on the trunk for GCC 15.

You should be able to just backport
r15-5661-gf6e00226a4ca63e76e3e0b3a09a4ce6223980981 and that will fix the issue.

[Bug c/124830] c/c-decl.cc Fails to cross compile with C++20 host compiler

[rguenth at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=124830

Richard Biener  changed:

   What|Removed |Added

 Ever confirmed|0   |1
 Status|UNCONFIRMED |ASSIGNED
   Last reconfirmed||2026-04-09
   Assignee|unassigned at gcc dot gnu.org  |rguenth at gcc dot 
gnu.org

--- Comment #5 from Richard Biener  ---
Will pick that and check it solves the issue.

[Bug c/124830] c/c-decl.cc Fails to cross compile with C++20 host compiler

[rguenth at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=124830

Richard Biener  changed:

   What|Removed |Added

  Known to fail||13.4.1, 14.3.1

--- Comment #1 from Richard Biener  ---
The 13 branch is affected in the same way.