[Bug c++/108560] New: builtin_va_arg_pack_len is documented to return size_t, but actually returns int

[Bug c++/108560] New: builtin_va_arg_pack_len is documented to return size_t, but actually returns int

[jens.seifert at de dot ibm.com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108560

            Bug ID: 108560
           Summary: builtin_va_arg_pack_len is documented to return
                    size_t, but actually returns int
           Product: gcc
           Version: 12.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jens.seifert at de dot ibm.com
  Target Milestone: ---

#include <stdio.h>

bool test(const char *fmt, size_t numTokens, ...)
{
    return __builtin_va_arg_pack_len() != numTokens;
}

Compiled with -Wsign-compare results in:
<source>: In function 'bool test(const char*, size_t, ...)':
<source>:5:40: warning: comparison of integer expressions of different
signedness: 'int' and 'size_t' {aka 'long unsigned int'} [-Wsign-compare]
    5 |     return __builtin_va_arg_pack_len() != numTokens;
      |            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~
<source>:5:37: error: invalid use of '__builtin_va_arg_pack_len ()'
    5 |     return __builtin_va_arg_pack_len() != numTokens;
      |            ~~~~~~~~~~~~~~~~~~~~~~~~~^~
Compiler returned: 1

Documentation:
https://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html
indicates a size_t return type
Built-in Function: size_t __builtin_va_arg_pack_len ()

[Bug c++/108560] builtin_va_arg_pack_len is documented to return size_t, but actually returns int

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108560

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jakub at gcc dot gnu.org

--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
This is a bug in the documentation, introduced with
r0-103077-gab940b73bfabe2cec4
which was meant to be a documentation formatting only change.

[Bug other/108560] builtin_va_arg_pack_len is documented to return size_t, but actually returns int

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108560

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
           Assignee|unassigned at gcc dot gnu.org      |jakub at gcc dot gnu.org
   Last reconfirmed|                            |2023-01-26
             Status|UNCONFIRMED                 |ASSIGNED

--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Created attachment 54353
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=54353&action=edit
gcc13-pr108560.patch

Untested fix.

[Bug other/108560] builtin_va_arg_pack_len is documented to return size_t, but actually returns int

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108560

--- Comment #3 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Jakub Jelinek <jakub@gcc.gnu.org>:

https://gcc.gnu.org/g:16f30680f403891556da2ad6329fcef9dc9b47db

commit r13-5437-g16f30680f403891556da2ad6329fcef9dc9b47db
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Fri Jan 27 11:17:35 2023 +0100

    doc: Fix up return type of __builtin_va_arg_pack_len [PR108560]

    __builtin_va_arg_pack_len as implemented returned int since its
introduction
    in 2007.  The initial documentation didn't mention any return type,
    which changed in 2010 in r0-103077-gab940b73bfabe2cec4 during some
    documentation formatting cleanups
    https://gcc.gnu.org/legacy-ml/gcc-patches/2010-09/msg01632.html
    I can understand that for formatting some type was needed there
    but what exactly hasn't been really discussed.

    So, I think we should change documentation to match the implementation,
    rather than change implementation to match the documentation.
    Most people don't use more than 2147483647 arguments to inline functions,
    and on poor targets with 16-bit ints I bet even having more than 65535
    arguments to inline functions would be highly unexpected.

    2023-01-27  Jakub Jelinek  <jakub@redhat.com>

            PR other/108560
            * doc/extend.texi: Fix up return type of __builtin_va_arg_pack_len
            from size_t to int.

[Bug other/108560] builtin_va_arg_pack_len is documented to return size_t, but actually returns int

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108560

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |FIXED
             Status|ASSIGNED                    |RESOLVED

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Fixed.

[Bug other/108560] builtin_va_arg_pack_len is documented to return size_t, but actually returns int

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108560

--- Comment #5 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-12 branch has been updated by Jakub Jelinek
<jakub@gcc.gnu.org>:

https://gcc.gnu.org/g:ca1e81324ab9915b745e724945db4a108777f46d

commit r12-9145-gca1e81324ab9915b745e724945db4a108777f46d
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Fri Jan 27 11:17:35 2023 +0100

    doc: Fix up return type of __builtin_va_arg_pack_len [PR108560]

    __builtin_va_arg_pack_len as implemented returned int since its
introduction
    in 2007.  The initial documentation didn't mention any return type,
    which changed in 2010 in r0-103077-gab940b73bfabe2cec4 during some
    documentation formatting cleanups
    https://gcc.gnu.org/legacy-ml/gcc-patches/2010-09/msg01632.html
    I can understand that for formatting some type was needed there
    but what exactly hasn't been really discussed.

    So, I think we should change documentation to match the implementation,
    rather than change implementation to match the documentation.
    Most people don't use more than 2147483647 arguments to inline functions,
    and on poor targets with 16-bit ints I bet even having more than 65535
    arguments to inline functions would be highly unexpected.

    2023-01-27  Jakub Jelinek  <jakub@redhat.com>

            PR other/108560
            * doc/extend.texi: Fix up return type of __builtin_va_arg_pack_len
            from size_t to int.

    (cherry picked from commit 16f30680f403891556da2ad6329fcef9dc9b47db)

[Bug other/108560] builtin_va_arg_pack_len is documented to return size_t, but actually returns int

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108560

--- Comment #6 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-11 branch has been updated by Jakub Jelinek
<jakub@gcc.gnu.org>:

https://gcc.gnu.org/g:4dd44d0c899897da041d2dcc088bed6e11abd80a

commit r11-10703-g4dd44d0c899897da041d2dcc088bed6e11abd80a
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Fri Jan 27 11:17:35 2023 +0100

    doc: Fix up return type of __builtin_va_arg_pack_len [PR108560]

    __builtin_va_arg_pack_len as implemented returned int since its
introduction
    in 2007.  The initial documentation didn't mention any return type,
    which changed in 2010 in r0-103077-gab940b73bfabe2cec4 during some
    documentation formatting cleanups
    https://gcc.gnu.org/legacy-ml/gcc-patches/2010-09/msg01632.html
    I can understand that for formatting some type was needed there
    but what exactly hasn't been really discussed.

    So, I think we should change documentation to match the implementation,
    rather than change implementation to match the documentation.
    Most people don't use more than 2147483647 arguments to inline functions,
    and on poor targets with 16-bit ints I bet even having more than 65535
    arguments to inline functions would be highly unexpected.

    2023-01-27  Jakub Jelinek  <jakub@redhat.com>

            PR other/108560
            * doc/extend.texi: Fix up return type of __builtin_va_arg_pack_len
            from size_t to int.

    (cherry picked from commit 16f30680f403891556da2ad6329fcef9dc9b47db)

[Bug other/108560] builtin_va_arg_pack_len is documented to return size_t, but actually returns int

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108560

--- Comment #7 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-10 branch has been updated by Jakub Jelinek
<jakub@gcc.gnu.org>:

https://gcc.gnu.org/g:5ebdbf03c7fb77c2535faca020e25a16658e8cb6

commit r10-11358-g5ebdbf03c7fb77c2535faca020e25a16658e8cb6
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Fri Jan 27 11:17:35 2023 +0100

    doc: Fix up return type of __builtin_va_arg_pack_len [PR108560]

    __builtin_va_arg_pack_len as implemented returned int since its
introduction
    in 2007.  The initial documentation didn't mention any return type,
    which changed in 2010 in r0-103077-gab940b73bfabe2cec4 during some
    documentation formatting cleanups
    https://gcc.gnu.org/legacy-ml/gcc-patches/2010-09/msg01632.html
    I can understand that for formatting some type was needed there
    but what exactly hasn't been really discussed.

    So, I think we should change documentation to match the implementation,
    rather than change implementation to match the documentation.
    Most people don't use more than 2147483647 arguments to inline functions,
    and on poor targets with 16-bit ints I bet even having more than 65535
    arguments to inline functions would be highly unexpected.

    2023-01-27  Jakub Jelinek  <jakub@redhat.com>

            PR other/108560
            * doc/extend.texi: Fix up return type of __builtin_va_arg_pack_len
            from size_t to int.

    (cherry picked from commit 16f30680f403891556da2ad6329fcef9dc9b47db)