[Bug c++/99208] New: [modules] ICE with partitions & instantiations of linkage-typedef structs

[Bug c++/99208] New: [modules] ICE with partitions & instantiations of linkage-typedef structs

[nathan at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99208

            Bug ID: 99208
           Summary: [modules] ICE with partitions & instantiations of
                    linkage-typedef structs
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: nathan at gcc dot gnu.org
  Target Milestone: ---

Triaging 98718 ran into this:

// b_a.ii
module;
# 3 "b_a.ii" 1
typedef struct {} __mbstate_t;
template<typename _StateT> class fpos;
# 6 "" 2
export module hello:format;
export void format (const fpos<__mbstate_t> &);

// b_b.ii
export module hello;
export import :format;

zathras:94>./cc1plus -quiet -fmodules-ts b_a.ii && ./cc1plus -quiet
-fmodules-ts b_b.ii    
b_b.ii:1:8: internal compiler error: in insert, at cp/module.cc:4904
    1 | export module hello;
      |        ^~~~~~
0xcb1949 trees_out::insert(tree_node*, walk_kind)
        ../../../src/gcc/cp/module.cc:4904
0xcbaf8f trees_out::add_indirects(tree_node*)
        ../../../src/gcc/cp/module.cc:7328
0xcc1f6a trees_out::decl_node(tree_node*, walk_kind)
        ../../../src/gcc/cp/module.cc:8677
0xcc41c1 trees_out::tree_node(tree_node*)
        ../../../src/gcc/cp/module.cc:9179
0xcb1e4e trees_out::vec_chained_decls(tree_node*)
        ../../../src/gcc/cp/module.cc:4992
0xcd17a0 trees_out::write_class_def(tree_node*)
        ../../../src/gcc/cp/module.cc:11748
0xcd5947 trees_out::write_definition(tree_node*)
        ../../../src/gcc/cp/module.cc:12356
0xcd9299 depset::hash::find_dependencies(module_state*)
        ../../../src/gcc/cp/module.cc:13238
0xce60ed module_state::write(elf_out*, cpp_reader*)
        ../../../src/gcc/cp/module.cc:17611
0xcec92c finish_module_processing(cpp_reader*)
        ../../../src/gcc/cp/module.cc:19860

[Bug c++/99208] [modules] ICE with partitions & instantiations of linkage-typedef structs

[nathan at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99208

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
           Assignee|unassigned at gcc dot gnu.org      |nathan at gcc dot gnu.org
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2021-02-22

[Bug c++/99208] [modules] ICE with partitions & instantiations of linkage-typedef structs

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99208

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

https://gcc.gnu.org/g:47145e6916f58e1cd4f562c06fa7289da49f690c

commit r11-7347-g47145e6916f58e1cd4f562c06fa7289da49f690c
Author: Nathan Sidwell <nathan@acm.org>
Date:   Tue Feb 23 07:08:55 2021 -0800

    c++: typedef for linkage [PR 99208]

    Unnamed types with a typedef name for linkage were always troublesome
    in modules.  This is the underlying cause of that trouble -- we were
    creating incorrect type structures.  Classes have an implicit
    self-reference, and we created that for unnamed classes too.  It turns
    out we make use of this member, so just not generating it turned into
    a rathole.  This member is created using the anonymous name -- because
    we've not yet met the typedef name.  When we retrofit the typedef name
    we were checking identifier matching and changing all type variants
    with that identifier.  Which meant we ended up with a strange typedef
    for the self reference.  This fixes things to check for DECL identity
    of the variants, so we don't smash the self-reference -- that
    continues to have the anonymous name.

            PR c++/99208
            gcc/cp/
            * decl.c (name_unnamed_type): Check DECL identity, not IDENTIFIER
            identity.
            gcc/testsuite/
            * g++.dg/modules/pr99208_a.C: New.
            * g++.dg/modules/pr99208_b.C: New.

[Bug c++/99208] [modules] ICE with partitions & instantiations of linkage-typedef structs

[nathan at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99208

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

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

--- Comment #2 from Nathan Sidwell <nathan at gcc dot gnu.org> ---
47145e6916f 2021-02-23 | c++: typedef for linkage [PR 99208]