[Bug c++/107134] New: fatal error: stdint.h: No such file or directory for freestanding C++ toolchain

[Bug c++/107134] New: fatal error: stdint.h: No such file or directory for freestanding C++ toolchain

[unlvsur at live dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107134

            Bug ID: 107134
           Summary: fatal error: stdint.h: No such file or directory for
                    freestanding C++ toolchain
           Product: gcc
           Version: 13.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: unlvsur at live dot com
  Target Milestone: ---

x86_64-elf-g++ -v
Using built-in specs.
COLLECT_GCC=x86_64-elf-g++
COLLECT_LTO_WRAPPER=/home/cqwrteur/toolchains/native/x86_64-elf/libexec/gcc/x86_64-elf/13.0.0/lto-wrapper
Target: x86_64-elf
Configured with: ../../../../gcc/configure --disable-nls --disable-werror
--target=x86_64-elf --prefix=/home/cqwrteur/toolchains/native/x86_64-elf
--without-headers --disable-hosted-libstdcxx --disable-libstdcxx-verbose
--enable-languages=c,c++ --enable-multilib
Thread model: single
Supported LTO compression algorithms: zlib
gcc version 13.0.0 20221003 (experimental) (GCC) 


x86_64-elf-g++ -c b.cc -std=c++23
In file included from
/home/cqwrteur/toolchains/native/x86_64-elf/x86_64-elf/include/c++/13.0.0/cstdint:41,
                 from b.cc:1:
/home/cqwrteur/toolchains/native/x86_64-elf/lib/gcc/x86_64-elf/13.0.0/include/stdint.h:9:16:
fatal error: stdint.h: No such file or directory
    9 | # include_next <stdint.h>
      |                ^~~~~~~~~~
compilation terminated.

stdint.h requires -ffreestanding flag to include the right header. However
--without-headers --disable-hosted-libstdcxx already implies it is
freestanding. it needs a fix the stdint.h

[Bug c++/107134] fatal error: stdint.h: No such file or directory for freestanding C++ toolchain

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107134

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
With current trunk, you need to use -ffreestanding if you are compiling for
freestanding.

--without-headers --disable-hosted-libstdcxx  says to build a freestanding
library, that doesn't tell the compiler anything when you invoke it.

[Bug c++/107134] fatal error: stdint.h: No such file or directory for freestanding C++ toolchain

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107134

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Although we could do:

#if ! _GLIBCXX_HOSTED
#include <stdint-gcc.h>
#else
#include_next <stdint.h>
#endif

to make it work.

[Bug c++/107134] fatal error: stdint.h: No such file or directory for freestanding C++ toolchain

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107134

--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to cqwrteur from comment #0)
> x86_64-elf-g++ -c b.cc -std=c++23
> In file included from
> /home/cqwrteur/toolchains/native/x86_64-elf/x86_64-elf/include/c++/13.0.0/
> cstdint:41,
>                  from b.cc:1:
> /home/cqwrteur/toolchains/native/x86_64-elf/lib/gcc/x86_64-elf/13.0.0/
> include/stdint.h:9:16: fatal error: stdint.h: No such file or directory

Wait a minute, why do you even have libstdc++'s <stdint.h> installed for this
configuration?

[Bug c++/107134] fatal error: stdint.h: No such file or directory for freestanding C++ toolchain

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107134

--- Comment #4 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Oh it's not libstdc++'s one, it's GCC's one.

[Bug c++/107134] fatal error: stdint.h: No such file or directory for freestanding C++ toolchain

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107134

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|---                         |DUPLICATE

--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> ---
I think this is another dup of PR 104605, we don't need a second bug about the
same thing.

*** This bug has been marked as a duplicate of bug 104605 ***

[Bug c++/107134] fatal error: stdint.h: No such file or directory for freestanding C++ toolchain

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107134

--- Comment #6 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Jonathan Wakely <redi@gcc.gnu.org>:

https://gcc.gnu.org/g:7cdab65f3d770345903023f357b6ca96bc85a002

commit r13-3059-g7cdab65f3d770345903023f357b6ca96bc85a002
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Mon Oct 3 21:49:27 2022 +0100

    libstdc++: Make <cstdint> work freestanding [PR107134]

    When gcc/config.gcc defines use_gcc_stdin=wrap, GCC's <stdint.h> tries
    to use libc's <stdint.h> unless -ffreestanding is used.

    When libstdc++ is configured --disable-hosted-libstdcxx we want
    <cstdint> to work even without -ffreestanding being given. This is a
    kluge to make it include GCC's <stdint-gcc.h> directly even without
    -ffreestanding.

    libstdc++-v3/ChangeLog:

            PR libstdc++/107134
            * include/c_global/cstdint [!_GLIBCXX_HOSTED]: Include
            <stdint-gcc.h> directly.