[Bug lto/106540] New: [13 Regression] lto -g ICE in dwarf2out_register_external_die at dwarf2out.cc:6076

[Bug lto/106540] New: [13 Regression] lto -g ICE in dwarf2out_register_external_die at dwarf2out.cc:6076

[slyfox at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106540

            Bug ID: 106540
           Summary: [13 Regression] lto -g ICE in
                    dwarf2out_register_external_die at dwarf2out.cc:6076
           Product: gcc
           Version: 13.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: lto
          Assignee: unassigned at gcc dot gnu.org
          Reporter: slyfox at gcc dot gnu.org
                CC: marxin at gcc dot gnu.org, rguenth at gcc dot gnu.org
  Target Milestone: ---

It's a very similar form of https://gcc.gnu.org/PR106334 where nix-2.10.3
package enabled -flto recently and started ICEing gcc.

This time I got the following 3-file reproducer:

  // $ cat eval.hh
    struct Value {
      auto listItems() {
        struct ListIterable {
          typedef int *iterator;
          iterator _begin, _end;
          iterator begin() { return _begin; }
          iterator end() { return _end; }
        };
        return ListIterable{};
      }
    };

  // $ cat eval-cache.cc
    #include "eval.hh"

    void AttrCursorgetListOfStrings(Value & v) {
      for (auto elem : v.listItems())
        ;
    }

  // $ cat eval.cc
    #include "eval.hh"
    template <typename T> auto enumerate(T) {
      struct iterator {
        int iter;
        bool operator!=(iterator) { return iter; }
        void operator++() {}
        auto operator*() { return 0; }
      };
      struct iterable_wrapper {
        auto begin() { return iterator{}; }
        auto end() { return iterator{}; }
      };
      return iterable_wrapper{};
    }
    void coerceToString(Value & v) {
      for (auto elem : enumerate(v.listItems()))
        ;
    }

Crashing:

$ g++ -O0 -flto -flto-partition=none -g1 -fPIC -I. -Wall -o eval.o -c eval.cc
eval.cc: In function 'void coerceToString(Value&)':
eval.cc:16:13: warning: unused variable 'elem' [-Wunused-variable]
   16 |   for (auto elem : enumerate(v.listItems()))
      |             ^~~~

$ g++ -O0 -flto -flto-partition=none -g1 -fPIC -I. -Wall -o eval-cache.o -c
eval-cache.cc
eval-cache.cc: In function 'void AttrCursorgetListOfStrings(Value&)':
eval-cache.cc:4:13: warning: unused variable 'elem' [-Wunused-variable]
    4 |   for (auto elem : v.listItems())
      |             ^~~~

$ g++ -O0 -flto -flto-partition=none -g1 -fPIC -I. -Wall -o libbug.so -shared
eval-cache.o eval.o

lto1: internal compiler error: in dwarf2out_register_external_die, at
dwarf2out.cc:6076
0xa093ff dwarf2out_register_external_die
        ../../gcc-13-20220731/gcc/dwarf2out.cc:6076
0x90743d lto_read_decls
        ../../gcc-13-20220731/gcc/lto/lto-common.cc:1952
0x908193 lto_file_finalize
        ../../gcc-13-20220731/gcc/lto/lto-common.cc:2271
0x908193 lto_create_files_from_ids
        ../../gcc-13-20220731/gcc/lto/lto-common.cc:2281
0x908193 lto_file_read
        ../../gcc-13-20220731/gcc/lto/lto-common.cc:2336
0x908193 read_cgraph_and_symbols(unsigned int, char const**)
        ../../gcc-13-20220731/gcc/lto/lto-common.cc:2784
0x8f0132 lto_main()
        ../../gcc-13-20220731/gcc/lto/lto.cc:626
Please submit a full bug report, with preprocessed source (by using
-freport-bug).
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.

It is a this week's gcc with
https://gcc.gnu.org/git/?p=gcc.git;a=commitdiff;h=bc7526f6fca0e6ac3bd462ae54170fa464539148
applied.

$ g++ -v |& unnix
Using built-in specs.
COLLECT_GCC=/<<NIX>>/gcc-13.0.0/bin/g++
COLLECT_LTO_WRAPPER=/<<NIX>>/gcc-13.0.0/libexec/gcc/x86_64-unknown-linux-gnu/13.0.0/lto-wrapper
Target: x86_64-unknown-linux-gnu
Configured with:
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 13.0.0 20220731 (experimental) (GCC)

I suspect this crash has something to do with auto-inferred types that are
defined within a function.

[Bug lto/106540] [13 Regression] lto -g ICE in dwarf2out_register_external_die at dwarf2out.cc:6076

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106540

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2022-08-08
     Ever confirmed|0                           |1
   Target Milestone|---                         |13.0
           Assignee|unassigned at gcc dot gnu.org      |rguenth at gcc dot gnu.org

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
I will have a look.

[Bug lto/106540] [13 Regression] lto -g ICE in dwarf2out_register_external_die at dwarf2out.cc:6076

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106540

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |ice-checking,
                   |                            |ice-on-valid-code

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
I have a real fix this time (I think).  LTO bootstrap in testing.

[Bug lto/106540] [13 Regression] lto -g ICE in dwarf2out_register_external_die at dwarf2out.cc:6076

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106540

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
It's a regression introduced with r11-525-g03d90a20a1afcb, but also backported
as r10-8619-g1144d3cf1ff3d4.  It might result in strange debug info references
as well so if it works out it's possibly worth backporting.

[Bug lto/106540] [13 Regression] lto -g ICE in dwarf2out_register_external_die at dwarf2out.cc:6076

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106540

--- Comment #4 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Richard Biener <rguenth@gcc.gnu.org>:

https://gcc.gnu.org/g:2a1448f2763a72c83e2ec496f78243a975b0d44e

commit r13-1987-g2a1448f2763a72c83e2ec496f78243a975b0d44e
Author: Richard Biener <rguenther@suse.de>
Date:   Mon Aug 8 09:07:23 2022 +0200

    lto/106540 - fix LTO tree input wrt dwarf2out_register_external_die

    I've revisited the earlier two workarounds for
dwarf2out_register_external_die
    getting duplicate entries.  It turns out that r11-525-g03d90a20a1afcb
    added dref_queue pruning to lto_input_tree but decl reading uses that
    to stream in DECL_INITIAL even when in the middle of SCC streaming.
    When that SCC then gets thrown away we can end up with debug nodes
    registered which isn't supposed to happen.  The following adjusts
    the DECL_INITIAL streaming to go the in-SCC way, using lto_input_tree_1,
    since no SCCs are expected at this point, just refs.

            PR lto/106540
            PR lto/106334
            * dwarf2out.cc (dwarf2out_register_external_die): Restore
            original assert.
            * lto-streamer-in.cc (lto_read_tree_1): Use lto_input_tree_1
            to input DECL_INITIAL, avoiding to commit drefs.

[Bug lto/106540] [10/11/12 Regression] lto -g ICE in dwarf2out_register_external_die at dwarf2out.cc:6076

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106540

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[13 Regression] lto -g ICE  |[10/11/12 Regression] lto
                   |in                          |-g ICE in
                   |dwarf2out_register_external |dwarf2out_register_external
                   |_die at dwarf2out.cc:6076   |_die at dwarf2out.cc:6076
      Known to work|                            |13.0
   Target Milestone|13.0                        |10.5
           Priority|P3                          |P2

--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fixed on trunk, it's a regression though.

[Bug lto/106540] [10/11/12 Regression] lto -g ICE in dwarf2out_register_external_die at dwarf2out.cc:6076

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106540

--- Comment #6 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-12 branch has been updated by Richard Biener
<rguenth@gcc.gnu.org>:

https://gcc.gnu.org/g:4769ac6c5dfde2810a0266fe388211edc644e623

commit r12-8676-g4769ac6c5dfde2810a0266fe388211edc644e623
Author: Richard Biener <rguenther@suse.de>
Date:   Mon Aug 8 09:07:23 2022 +0200

    lto/106540 - fix LTO tree input wrt dwarf2out_register_external_die

    I've revisited the earlier two workarounds for
dwarf2out_register_external_die
    getting duplicate entries.  It turns out that r11-525-g03d90a20a1afcb
    added dref_queue pruning to lto_input_tree but decl reading uses that
    to stream in DECL_INITIAL even when in the middle of SCC streaming.
    When that SCC then gets thrown away we can end up with debug nodes
    registered which isn't supposed to happen.  The following adjusts
    the DECL_INITIAL streaming to go the in-SCC way, using lto_input_tree_1,
    since no SCCs are expected at this point, just refs.

            PR lto/106540
            PR lto/106334
            * lto-streamer-in.cc (lto_read_tree_1): Use lto_input_tree_1
            to input DECL_INITIAL, avoiding to commit drefs.

    (cherry picked from commit 2a1448f2763a72c83e2ec496f78243a975b0d44e)

[Bug lto/106540] [10/11 Regression] lto -g ICE in dwarf2out_register_external_die at dwarf2out.cc:6076

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106540

--- Comment #7 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-11 branch has been updated by Richard Biener
<rguenth@gcc.gnu.org>:

https://gcc.gnu.org/g:752d7664325037789ee4b634672e8e737ad9469c

commit r11-10307-g752d7664325037789ee4b634672e8e737ad9469c
Author: Richard Biener <rguenther@suse.de>
Date:   Mon Aug 8 09:07:23 2022 +0200

    lto/106540 - fix LTO tree input wrt dwarf2out_register_external_die

    I've revisited the earlier two workarounds for
dwarf2out_register_external_die
    getting duplicate entries.  It turns out that r11-525-g03d90a20a1afcb
    added dref_queue pruning to lto_input_tree but decl reading uses that
    to stream in DECL_INITIAL even when in the middle of SCC streaming.
    When that SCC then gets thrown away we can end up with debug nodes
    registered which isn't supposed to happen.  The following adjusts
    the DECL_INITIAL streaming to go the in-SCC way, using lto_input_tree_1,
    since no SCCs are expected at this point, just refs.

            PR lto/106540
            PR lto/106334
            * lto-streamer-in.c (lto_read_tree_1): Use lto_input_tree_1
            to input DECL_INITIAL, avoiding to commit drefs.

    (cherry picked from commit 4769ac6c5dfde2810a0266fe388211edc644e623)

[Bug lto/106540] [10 Regression] lto -g ICE in dwarf2out_register_external_die at dwarf2out.cc:6076

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106540

--- Comment #8 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-10 branch has been updated by Richard Biener
<rguenth@gcc.gnu.org>:

https://gcc.gnu.org/g:d2fa5521282cc7b5510e1e2c431a56d12693d74f

commit r10-11039-gd2fa5521282cc7b5510e1e2c431a56d12693d74f
Author: Richard Biener <rguenther@suse.de>
Date:   Mon Aug 8 09:07:23 2022 +0200

    lto/106540 - fix LTO tree input wrt dwarf2out_register_external_die

    I've revisited the earlier two workarounds for
dwarf2out_register_external_die
    getting duplicate entries.  It turns out that r11-525-g03d90a20a1afcb
    added dref_queue pruning to lto_input_tree but decl reading uses that
    to stream in DECL_INITIAL even when in the middle of SCC streaming.
    When that SCC then gets thrown away we can end up with debug nodes
    registered which isn't supposed to happen.  The following adjusts
    the DECL_INITIAL streaming to go the in-SCC way, using lto_input_tree_1,
    since no SCCs are expected at this point, just refs.

            PR lto/106540
            PR lto/106334
            * lto-streamer-in.c (lto_read_tree_1): Use lto_input_tree_1
            to input DECL_INITIAL, avoiding to commit drefs.

    (cherry picked from commit 4769ac6c5dfde2810a0266fe388211edc644e623)

[Bug lto/106540] [10 Regression] lto -g ICE in dwarf2out_register_external_die at dwarf2out.cc:6076

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106540

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to work|                            |10.4.1
         Resolution|---                         |FIXED
             Status|ASSIGNED                    |RESOLVED
      Known to fail|                            |10.4.0

--- Comment #9 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fixed.