[Bug c++/98327] New: C++ Module ICE on Linux

[Bug c++/98327] New: C++ Module ICE on Linux

[euloanty at live dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98327

            Bug ID: 98327
           Summary: C++ Module ICE on Linux
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: euloanty at live dot com
  Target Milestone: ---

cqwrteur@Home-Server:~/wwwww/working$ g++ -o hello hello.cc -std=c++20
-fmodules-ts
hello.cc:4:8: internal compiler error: Segmentation fault
    4 | export module hello;
      |        ^~~~~~
0x10ab5cf crash_signal
        ../../gcc/gcc/toplev.c:327
0x9f8667 has_definition
        ../../gcc/gcc/cp/module.cc:11361
0xa0a867 depset::hash::make_dependency(tree_node*, depset::entity_kind)
        ../../gcc/gcc/cp/module.cc:12531
0xa0af44 depset::hash::add_dependency(tree_node*, depset::entity_kind)
        ../../gcc/gcc/cp/module.cc:12669
0xa11f9a trees_out::decl_node(tree_node*, walk_kind)
        ../../gcc/gcc/cp/module.cc:8569
0xa12702 trees_out::tree_node(tree_node*)
        ../../gcc/gcc/cp/module.cc:9132
0xa13131 trees_out::core_vals(tree_node*)
        ../../gcc/gcc/cp/module.cc:5990
0xa164d4 trees_out::tree_node_vals(tree_node*)
        ../../gcc/gcc/cp/module.cc:7124
0xa164d4 trees_out::tree_value(tree_node*)
        ../../gcc/gcc/cp/module.cc:8939
0xa12564 trees_out::tree_node(tree_node*)
        ../../gcc/gcc/cp/module.cc:9137
0xa13131 trees_out::core_vals(tree_node*)
        ../../gcc/gcc/cp/module.cc:5990
0xa164d4 trees_out::tree_node_vals(tree_node*)
        ../../gcc/gcc/cp/module.cc:7124
0xa164d4 trees_out::tree_value(tree_node*)
        ../../gcc/gcc/cp/module.cc:8939
0xa12564 trees_out::tree_node(tree_node*)
        ../../gcc/gcc/cp/module.cc:9137
0xa13131 trees_out::core_vals(tree_node*)
        ../../gcc/gcc/cp/module.cc:5990
0xa164d4 trees_out::tree_node_vals(tree_node*)
        ../../gcc/gcc/cp/module.cc:7124
0xa164d4 trees_out::tree_value(tree_node*)
        ../../gcc/gcc/cp/module.cc:8939
0xa12564 trees_out::tree_node(tree_node*)
        ../../gcc/gcc/cp/module.cc:9137
0xa13131 trees_out::core_vals(tree_node*)
        ../../gcc/gcc/cp/module.cc:5990
0xa164d4 trees_out::tree_node_vals(tree_node*)
        ../../gcc/gcc/cp/module.cc:7124
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.
cqwrteur@Home-Server:~/wwwww/working$

[Bug c++/98327] C++ Module ICE on Linux

[euloanty at live dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98327

fdlbxtqi <euloanty at live dot com> changed:

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

--- Comment #1 from fdlbxtqi <euloanty at live dot com> ---
module;
#include <iostream>
#include <string_view>
export module hello;
export inline void greeter (std::string_view name) noexcept
{
  std::cout << "Hello " << name << "!\n";
}

[Bug c++/98327] C++ Module ICE on Linux

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98327

Martin Liška <marxin at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2020-12-17
                 CC|                            |marxin at gcc dot gnu.org
             Status|UNCONFIRMED                 |WAITING
     Ever confirmed|0                           |1

--- Comment #2 from Martin Liška <marxin at gcc dot gnu.org> ---
Can't reproduce with the current master:

$ g++ pr98327.cc -c -fmodules-ts -std=c++20
pr98327.cc:3:8: error: module-declaration not permitted here
    3 | export module hello;
      |        ^~~~~~
pr98327.cc:4:1: error: ‘export’ may only occur after a module interface
declaration
    4 | export inline void greeter (std::string_view name) noexcept
      | ^~~~~~

[Bug c++/98327] C++ Module ICE on Linux

[nathan at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98327

Nathan Sidwell <nathan at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|WAITING                     |ASSIGNED
           Assignee|unassigned at gcc dot gnu.org      |nathan at gcc dot gnu.org

--- Comment #3 from Nathan Sidwell <nathan at gcc dot gnu.org> ---
three things.
a) I think this is now fixed

b) it's not invalid code

c) Martin, I think you're falling foul of some of the requirements of where you
place code that is in the GMF (the bit between 'module;' and '[export] module
foo;'  But I think the diagnostic you're getting is not helping there.

[Bug c++/98327] C++ Module ICE on Linux

[nathan at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98327

--- Comment #4 from Nathan Sidwell <nathan at gcc dot gnu.org> ---
I cannot reproduce the reported crash -- like I said, I think this is fixed
(thanks for the backtrace).

I suspect Martin failed to copy the first line of the testcase 'module;' 
That's important -- it's not an English introduction of a piece of code :)

The error message could be improved to say where these decls are permitted,
rather than 'computer says no'.

[Bug c++/98327] C++ Module ICE on Linux

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98327

--- Comment #5 from Martin Liška <marxin at gcc dot gnu.org> ---
> I suspect Martin failed to copy the first line of the testcase 'module;' 
> That's important -- it's not an English introduction of a piece of code :)
> 

Yep, I failed to do that :)

Anyway, now I can bisect that it was fixed with r11-6309-g8be20b9e0d6d53d8.

[Bug c++/98327] C++ Module ICE on Linux

[nathan at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98327

Nathan Sidwell <nathan at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|ice-on-invalid-code         |ice-on-valid-code
             Status|ASSIGNED                    |RESOLVED
         Resolution|---                         |FIXED

--- Comment #6 from Nathan Sidwell <nathan at gcc dot gnu.org> ---
Diagnostic adjusted
 6ffaffd5d10 2021-01-05 | [c++]: Improve module-decl diagnostics [PR 98327]