[Bug c/95630] New: rejects-valid on comparison of pointers to complete vs incomplete types in C11 mode

[Bug c/95630] New: rejects-valid on comparison of pointers to complete vs incomplete types in C11 mode

[richard-gccbugzilla at metafoo dot co.uk]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95630

            Bug ID: 95630
           Summary: rejects-valid on comparison of pointers to complete vs
                    incomplete types in C11 mode
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: richard-gccbugzilla at metafoo dot co.uk
  Target Milestone: ---

Testcase:

int f(int (*p)[], int (*q)[3]) { return p < q; }

This is a constraint violation in C99, but the relevant rule was removed in
C11. GCC still rejects in -std=c11 mode under -pedantic-errors.

[Bug c/95630] rejects-valid on comparison of pointers to complete vs incomplete types in C11 mode

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95630

--- Comment #1 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Joseph Myers <jsm28@gcc.gnu.org>:

https://gcc.gnu.org/g:ed431431e069b59a1cfdd877134873248d8c93a6

commit r11-5265-ged431431e069b59a1cfdd877134873248d8c93a6
Author: Joseph Myers <joseph@codesourcery.com>
Date:   Mon Nov 23 23:28:58 2020 +0000

    c: Allow comparison of pointers to complete and incomplete types for C11
[PR95630]

    As noted in bug 95630, C11 removed a restriction in C99 on comparing
    pointers to compatible complete and incomplete types (this was one of
    the changes in N1439, which was largely a terminological change to
    make incomplete types a subset of object types rather than a different
    kind of type).  Implement that change by using pedwarn_c99 with
    OPT_Wpedantic for this diagnostic.

    Bootstrapped with no regressions for x86_64-pc-linux-gnu.

    gcc/c/
    2020-11-23  Joseph Myers  <joseph@codesourcery.com>

            PR c/95630
            * c-typeck.c (build_binary_op): Use pedwarn_c99 with OPT_Wpedantic
            for comparisons of complete and incomplete pointers.

    gcc/testsuite/
    2020-11-23  Joseph Myers  <joseph@codesourcery.com>

            PR c/95630
            * gcc.dg/c11-compare-incomplete-1.c,
            gcc.dg/c11-compare-incomplete-2.c,
            gcc.dg/c99-compare-incomplete-1.c,
            gcc.dg/c99-compare-incomplete-2.c: New tests.

[Bug c/95630] rejects-valid on comparison of pointers to complete vs incomplete types in C11 mode

[jsm28 at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95630

Joseph S. Myers <jsm28 at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|---                         |FIXED
   Target Milestone|---                         |11.0

--- Comment #2 from Joseph S. Myers <jsm28 at gcc dot gnu.org> ---
Fixed for GCC 11.