[Bug libstdc++/100583] New: [modules] ICE when importing <span>

[Bug libstdc++/100583] New: [modules] ICE when importing <span>

[andreemalcher at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100583

            Bug ID: 100583
           Summary: [modules] ICE when importing <span>
           Product: gcc
           Version: 11.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: andreemalcher at gmail dot com
  Target Milestone: ---

$ g++ --version
g++ (Ubuntu 11.1.0-1ubuntu1~18.04.1) 11.1.0
Copyright (C) 2021 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
$ cat span.cpp
import <span>;
void foo() { std::span<int> s; }
$ g++ -fmodules-ts -std=c++20 -c -x c++-system-header span
$ g++ -fmodules-ts -std=c++20 -c span.cpp
In module /usr/include/c++/11/span, imported at span.cpp:1:
/usr/include/c++/11/span: In instantiation of ‘class std::span<int>’:
span.cpp:4:29:   required from here
/usr/include/c++/11/span:155:9: internal compiler error: Segmentation fault
  155 |         span(_It __first, size_type __count)
      |         ^~~~
0x1702697 internal_error(char const*, ...)
        ???:0
0x7bfc52 instantiate_class_template(tree_node*)
        ???:0
0x7f17ab complete_type(tree_node*)
        ???:0
0x6af20b start_decl_1(tree_node*, bool)
        ???:0
0x6c1e0f start_decl(cp_declarator const*, cp_decl_specifier_seq*, int,
tree_node*, tree_node*, tree_node**)
        ???:0
0x7888ee c_parse_file()
        ???:0
0x85988d c_common_parse_file()
        ???:0
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <file:///usr/share/doc/gcc-11/README.Bugs> for instructions.


Even if import <span> is replaced with #include <span>, the sheer presence of
span.gcm leads to an ICE when compiled with -fmodules-ts. The solution is to
use the include and remove the gcm file altogether.But this means that there is
no way of importing <span> as a module.

[Bug c++/100583] [modules] ICE when importing <span>

[johelegp at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100583

--- Comment #1 from Johel Ernesto Guerrero Peña <johelegp at gmail dot com> ---
Please, add Bug 99227 to **Blocks:** for visibility.

[Bug c++/100583] [modules] ICE when importing <span>

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100583

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2021-09-28
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Johel Ernesto Guerrero Peña from comment #1)
> Please, add Bug 99227 to **Blocks:** for visibility.

Done

[Bug c++/100583] [modules] ICE when importing <span>

[johelegp at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100583

--- Comment #3 from Johel Ernesto Guerrero Peña <johelegp at gmail dot com> ---
Thank you.

> The solution is to use the include and remove the gcm file altogether.

Is this still the case? I still get an ICE.

[Bug c++/100583] [modules] ICE when importing <span>

[johelegp at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100583

--- Comment #4 from Johel Ernesto Guerrero Peña <johelegp at gmail dot com> ---
As pointed out in https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103118#c3:

> What works is including them in a non-module unit translation unit.
> 
> ```C++
> #if defined(__GNUC__) and not defined(__clang__)
> #  include <chrono> // Workaround GCC bug 103118.
> #  include <span>   // Workaround GCC bug 100583.
> #endif
> import waarudo.geometries;
> import waarudo.numbers;
> import waarudo.quantities;
> #include <cassert>
> ```

[Bug c++/100583] [modules] ICE when importing <span>

[johelegp at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100583

--- Comment #5 from Johel Ernesto Guerrero Peña <johelegp at gmail dot com> ---
This was fixed somewhere along the way.

[Bug c++/100583] [modules] ICE when importing <span>

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100583

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |12.0
             Status|NEW                         |RESOLVED
         Resolution|---                         |DUPLICATE

--- Comment #6 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Fixed by commit r12-7133-g1ce5395977f37e

Date:   Wed Feb 9 00:31:12 2022 -0500

    c++: modules and explicit(bool) [PR103752]

    We weren't streaming a C++20 dependent explicit-specifier.

            PR c++/103752

    gcc/cp/ChangeLog:

            * module.cc (trees_out::core_vals): Stream explicit specifier.
            (trees_in::core_vals): Likewise.
            * pt.cc (store_explicit_specifier): No longer static.
            (tsubst_function_decl): Clear DECL_HAS_DEPENDENT_EXPLICIT_SPEC_P.
            * cp-tree.h (lookup_explicit_specifier): Declare.

*** This bug has been marked as a duplicate of bug 103752 ***