[Bug other/113038] New: [14 regression] Excess errors for g++.dg/modules/hello-1_b.C after r14-6569-gfe54b57728c09a

[Bug other/113038] New: [14 regression] Excess errors for g++.dg/modules/hello-1_b.C after r14-6569-gfe54b57728c09a

[seurer at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113038

            Bug ID: 113038
           Summary: [14 regression] Excess errors for
                    g++.dg/modules/hello-1_b.C  after
                    r14-6569-gfe54b57728c09a
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: other
          Assignee: unassigned at gcc dot gnu.org
          Reporter: seurer at gcc dot gnu.org
  Target Milestone: ---

g:fe54b57728c09ab0389e2bb3f079d5210566199d, r14-6569-gfe54b57728c09a

FAIL: g++.dg/modules/hello-1 -std=c++2b execute
FAIL: g++.dg/modules/hello-1_b.C -std=c++2b (test for excess errors)


spawn -ignore SIGHUP
/home/seurer/gcc/git/build/gcc-test/gcc/testsuite/g++13/../../xg++
-B/home/seurer/gcc/git/build/gcc-test/gcc/testsuite/g++13/../../
/home/seurer/gcc/git/gcc-test/gcc/testsuite/g++.dg/modules/hello-1_b.C
-fdiagnostics-plain-output -nostdinc++
-I/home/seurer/gcc/git/build/gcc-test/powerpc64le-unknown-linux-gnu/libstdc++-v3/include/powerpc64le-unknown-linux-gnu
-I/home/seurer/gcc/git/build/gcc-test/powerpc64le-unknown-linux-gnu/libstdc++-v3/include
-I/home/seurer/gcc/git/gcc-test/libstdc++-v3/libsupc++
-I/home/seurer/gcc/git/gcc-test/libstdc++-v3/include/backward
-I/home/seurer/gcc/git/gcc-test/libstdc++-v3/testsuite/util -fmessage-length=0
-std=c++2b -pedantic-errors -Wno-long-long -fmodules-ts -S -o hello-1_b.s^M
/home/seurer/gcc/git/build/gcc-test/powerpc64le-unknown-linux-gnu/libstdc++-v3/include/bits/locale_classes.tcc:
In instantiation of 'const _Facet* std::__try_use_facet@hello(const
locale@hello&) [with _Facet = ctype@hello<char>]':^M
/home/seurer/gcc/git/build/gcc-test/powerpc64le-unknown-linux-gnu/libstdc++-v3/include/bits/locale_classes.tcc:200:59:
  required from 'const _Facet& std::use_facet@hello(const locale@hello&) [with
_Facet = ctype@hello<char>]'^M
/home/seurer/gcc/git/build/gcc-test/powerpc64le-unknown-linux-gnu/libstdc++-v3/include/bits/locale_facets_nonio.tcc:1573:63:
  required from '_InIter std::__cxx11::time_get@hello<_CharT,
_InIter>::do_get(iter_type, iter_type, std::ios_base&, std::ios_base::iostate&,
tm*, char, char) const [with _CharT = char; _InIter =
std::istreambuf_iterator<char, std::char_traits<char> >; iter_type =
std::istreambuf_iterator<char, std::char_traits<char> >; std::ios_base::iostate
= std::ios_base::iostate]'^M
/home/seurer/gcc/git/build/gcc-test/powerpc64le-unknown-linux-gnu/libstdc++-v3/include/bits/locale_facets_nonio.tcc:1567:5:
  required from here^M
<built-in>: warning: new declaration 'void* __cxxabiv1::__dynamic_cast(const
void*, const __class_type_info*, const __class_type_info*, long int)'
ambiguates built-in declaration 'void* __cxxabiv1::__dynamic_cast@hello(const
void*, const __class_type_info@hello*, const __class_type_info@hello*, long
int)' [-Wbuiltin-declaration-mismatch]^M
FAIL: g++.dg/modules/hello-1_b.C -std=c++2b (test for excess errors)
Excess errors:
<built-in>: warning: new declaration 'void* __cxxabiv1::__dynamic_cast(const
void*, const __class_type_info*, const __class_type_info*, long int)'
ambiguates built-in declaration 'void* __cxxabiv1::__dynamic_cast@hello(const
void*, const __class_type_info@hello*, const __class_type_info@hello*, long
int)' [-Wbuiltin-declaration-mismatch]


commit fe54b57728c09ab0389e2bb3f079d5210566199d (HEAD)
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Thu Dec 14 23:23:34 2023 +0000

    libstdc++: Implement C++23 <print> header [PR107760]

[Bug c++/113038] [14 regression] Excess errors for g++.dg/modules/hello-1_b.C after r14-6569-gfe54b57728c09a

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113038

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2023-12-16
             Target|powerpc64le-linux-gnu       |
             Status|UNCONFIRMED                 |NEW
               Host|powerpc64le-linux-gnu       |
     Ever confirmed|0                           |1
              Build|powerpc64le-linux-gnu       |

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
It's seen on other targets too. Patrick came up with this reduced reproducer
for it:

--- a/gcc/testsuite/g++.dg/modules/pr106304_b.C
+++ b/gcc/testsuite/g++.dg/modules/pr106304_b.C
@@ -5,4 +5,5 @@ module pr106304;

 void f(A& a) {
   as_b(a);
+  dynamic_cast<B*>(&a);
 }

Just another latent front-end modules bug, that gets triggered by my new
library code.

[Bug c++/113038] [14 regression] Excess errors for g++.dg/modules/hello-1_b.C after r14-6569-gfe54b57728c09a

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113038

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
jason: seems like a simple matter of forcing the builtin declaration into the
global module

ppalka: fwiw it also works if we get rid of the implicit declaration of
__class_type_info when declaring the builtin and just use const void*
throughout the parameter list

[Bug c++/113038] [14 regression] Excess errors for g++.dg/modules/hello-1_b.C after r14-6569-gfe54b57728c09a

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113038

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |testsuite-fail
   Target Milestone|---                         |14.0

[Bug c++/113038] [14 regression] Excess errors for g++.dg/modules/hello-1_b.C after r14-6569-gfe54b57728c09a

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113038

Jason Merrill <jason at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jason at gcc dot gnu.org
             Status|NEW                         |ASSIGNED
           Assignee|unassigned at gcc dot gnu.org      |jason at gcc dot gnu.org

[Bug c++/113038] [14 regression] Excess errors for g++.dg/modules/hello-1_b.C after r14-6569-gfe54b57728c09a

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113038

--- Comment #3 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The trunk branch has been updated by Jason Merrill <jason@gcc.gnu.org>:

https://gcc.gnu.org/g:27521a2f4f7b859d5656e5bdd69d3f759ea4c23a

commit r14-7213-g27521a2f4f7b859d5656e5bdd69d3f759ea4c23a
Author: Jason Merrill <jason@redhat.com>
Date:   Mon Dec 18 15:47:10 2023 -0500

    c++: __class_type_info and modules [PR113038]

    Doing a dynamic_cast in both TUs broke because we were declaring a new
    __class_type_info in _b that conflicted with the one imported in the global
    module from _a.  It seems clear to me that any new class declaration in
    the global module should merge with an imported definition, but for GCC 14
    let's just fix this for the specific case of __class_type_info.

            PR c++/113038

    gcc/cp/ChangeLog:

            * name-lookup.cc (lookup_elaborated_type): Look for bindings
            in the global namespace in the ABI namespace.

    gcc/testsuite/ChangeLog:

            * g++.dg/modules/pr106304_b.C: Add dynamic_cast.

[Bug c++/113038] [14 regression] Excess errors for g++.dg/modules/hello-1_b.C after r14-6569-gfe54b57728c09a

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113038

--- Comment #4 from Jason Merrill <jason at gcc dot gnu.org> ---
Created attachment 57052
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=57052&action=edit
more general approach WIP for GCC 15

this is the beginning of a more general approach to this issue that also
handles P1811 include-after-import.  More work will be needed.

[Bug c++/113038] [14 regression] Excess errors for g++.dg/modules/hello-1_b.C after r14-6569-gfe54b57728c09a

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113038

--- Comment #5 from Jason Merrill <jason at gcc dot gnu.org> ---
Created attachment 57053
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=57053&action=edit
second piece

and an accompanying patch to allow P1811 redefinition of classes.  I think we
need to extend this to all redefinitions, especially with -fno-module-lazy

[Bug c++/113038] [14 regression] Excess errors for g++.dg/modules/hello-1_b.C after r14-6569-gfe54b57728c09a

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113038

Jason Merrill <jason at gcc dot gnu.org> changed:

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

--- Comment #6 from Jason Merrill <jason at gcc dot gnu.org> ---
But the regression is fixed.

[Bug c++/113038] [14 regression] Excess errors for g++.dg/modules/hello-1_b.C after r14-6569-gfe54b57728c09a

[hp at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113038

Hans-Peter Nilsson <hp at gcc dot gnu.org> changed:

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

--- Comment #7 from Hans-Peter Nilsson <hp at gcc dot gnu.org> ---
(In reply to Jason Merrill from comment #6)
> But the regression is fixed.

Only partially: the "g++.dg/modules/hello-1 -std=c++2b execute"
is still there, and was part of the regression; at least introduced at the same
time.  This both for cris-elf@r14-7217-g444a31f3b354 and
powerpc64le-unknown-linux-gnu@r14-7215-g8b447fa89d
(https://gcc.gnu.org/pipermail/gcc-testresults/2024-January/805221.html).

Thus reopening.

[Bug c++/113038] [14 regression] Excess errors for g++.dg/modules/hello-1_b.C after r14-6569-gfe54b57728c09a

[danglin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113038

John David Anglin <danglin at gcc dot gnu.org> changed:

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

--- Comment #8 from John David Anglin <danglin at gcc dot gnu.org> ---
> Only partially: the "g++.dg/modules/hello-1 -std=c++2b execute"
> is still there, and was part of the regression; at least introduced at the
> same time.

Same failure is observed on hppa64-hp-hpux11.11.

[Bug c++/113038] [14 regression] Excess errors for g++.dg/modules/hello-1_b.C after r14-6569-gfe54b57728c09a

[hp at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113038

--- Comment #9 from Hans-Peter Nilsson <hp at gcc dot gnu.org> ---
For cris-elf, a change in the range (known to fail, known to pass]
(r14-8193-g3340878009acfc, r14-8200-g9a5e8f9d112adb] seems to have fixed the
remaining hello-1 execution failure, so fixed by r14-8196-g3471a61ed0ddef
(being a change to the c++ modules code and the only code change outside
riscv).

Being the person that reopened the PR, I think I'm going to reclose this if I
can find support for it being fixed on one more target.

[Bug c++/113038] [14 regression] Excess errors for g++.dg/modules/hello-1_b.C after r14-6569-gfe54b57728c09a

[hp at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113038

Hans-Peter Nilsson <hp at gcc dot gnu.org> changed:

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

--- Comment #10 from Hans-Peter Nilsson <hp at gcc dot gnu.org> ---
(In reply to Hans-Peter Nilsson from comment #9)
> I'm going to reclose this if
> I can find support for it being fixed on one more target.

So, https://gcc.gnu.org/pipermail/gcc-testresults/2024-January/805640.html
says it's fixed for power8 too, compared to the previous report, for r14-8195.

[Bug c++/113038] [14 regression] Excess errors for g++.dg/modules/hello-1_b.C after r14-6569-gfe54b57728c09a

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113038

--- Comment #11 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
I can confirm it is also fixed on aarch64.