[Bug c++/29985] New: gdbtypes.h:985: internal-error: field: Assertion `idx >= 0 && idx < num_fields ()' failed.

[Bug c++/29985] New: gdbtypes.h:985: internal-error: field: Assertion `idx >= 0 && idx < num_fields ()' failed.

[pawel_sikora at zoho dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=29985

            Bug ID: 29985
           Summary: gdbtypes.h:985: internal-error: field: Assertion `idx
                    >= 0 && idx < num_fields ()' failed.
           Product: gdb
           Version: HEAD
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c++
          Assignee: unassigned at sourceware dot org
          Reporter: pawel_sikora at zoho dot com
  Target Milestone: ---

hi,
a large c++ enum-class crashes gdb during variable printing.

(gdb) r
Starting program: /home/pawels/src/bugs/gdb-big-enum/test 
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".

Breakpoint 1, main () at test.cpp:5
5           enumVal = ENUM_ID::ENUM_VAL_14;
(gdb) n
6           return 0;
(gdb) p enumVal
$1 = 
gdbtypes.h:985: internal-error: field: Assertion `idx >= 0 && idx < num_fields
()' failed.
A problem internal to GDB has been detected,
further debugging may prove unreliable.
----- Backtrace -----
0x56522c4cabf0 gdb_internal_backtrace_1
        /home/pawels/src/binutils-gdb/gdb/bt-utils.c:122
0x56522c4cabf0 _Z22gdb_internal_backtracev
        /home/pawels/src/binutils-gdb/gdb/bt-utils.c:168
0x56522c88a564 internal_vproblem
        /home/pawels/src/binutils-gdb/gdb/utils.c:396
0x56522c88a820 _Z15internal_verrorPKciS0_P13__va_list_tag
        /home/pawels/src/binutils-gdb/gdb/utils.c:476
0x56522c9d6d34 _Z18internal_error_locPKciS0_z
        /home/pawels/src/binutils-gdb/gdbsupport/errors.cc:58
0x56522c89a6d2 _ZNK4type5fieldEi
        /home/pawels/src/binutils-gdb/gdb/gdbtypes.h:985
0x56522c89a6d2 _ZNK4type5fieldEi
        /home/pawels/src/binutils-gdb/gdb/gdbtypes.h:983
0x56522c89a6d2 generic_val_print_enum_1
        /home/pawels/src/binutils-gdb/gdb/valprint.c:657
0x56522c89b3ca
_Z16common_val_printP5valueP7ui_fileiPK19value_print_optionsPK13language_defn
        /home/pawels/src/binutils-gdb/gdb/valprint.c:1073
0x56522c4ef9d0 _Z13c_value_printP5valueP7ui_filePK19value_print_options
        /home/pawels/src/binutils-gdb/gdb/c-valprint.c:588
0x56522c89b572 _Z11value_printP5valueP7ui_filePK19value_print_options
        /home/pawels/src/binutils-gdb/gdb/valprint.c:1190
0x56522c72e334 _Z11print_valueP5valueRK19value_print_options
        /home/pawels/src/binutils-gdb/gdb/printcmd.c:1252
0x56522c72e5c2 print_command_1
        /home/pawels/src/binutils-gdb/gdb/printcmd.c:1361
0x56522c4ff1e4 _Z8cmd_funcP16cmd_list_elementPKci
        cli/cli-decode.c:2543
0x56522c820ad1 _Z15execute_commandPKci
        /home/pawels/src/binutils-gdb/gdb/top.c:688
0x56522c5ef524 _Z15command_handlerPKc
        /home/pawels/src/binutils-gdb/gdb/event-top.c:616
0x56522c5f0833
_Z20command_line_handlerOSt10unique_ptrIcN3gdb13xfree_deleterIcEEE
        /home/pawels/src/binutils-gdb/gdb/event-top.c:852
0x56522c5eff7c gdb_rl_callback_handler
        /home/pawels/src/binutils-gdb/gdb/event-top.c:246
0x56522c8ccdd7 rl_callback_read_char
        /home/pawels/src/binutils-gdb/readline/readline/callback.c:290
0x56522c5eefbd gdb_rl_callback_read_char_wrapper_noexcept
        /home/pawels/src/binutils-gdb/gdb/event-top.c:188
0x56522c5efe33 gdb_rl_callback_read_char_wrapper
        /home/pawels/src/binutils-gdb/gdb/event-top.c:221
0x56522c5ee9af stdin_event_handler
        /home/pawels/src/binutils-gdb/gdb/event-top.c:541
0x56522c9d7495 gdb_wait_for_event
        /home/pawels/src/binutils-gdb/gdbsupport/event-loop.cc:694
0x56522c9d7eb5 gdb_wait_for_event
        /home/pawels/src/binutils-gdb/gdbsupport/event-loop.cc:593
0x56522c9d7eb5 _Z16gdb_do_one_eventi
        /home/pawels/src/binutils-gdb/gdbsupport/event-loop.cc:264
0x56522c6cb8e9 start_event_loop
        /home/pawels/src/binutils-gdb/gdb/main.c:411
0x56522c6cb8e9 captured_command_loop
        /home/pawels/src/binutils-gdb/gdb/main.c:471
0x56522c6cd484 captured_main
        /home/pawels/src/binutils-gdb/gdb/main.c:1310
0x56522c6cd484 _Z8gdb_mainP18captured_main_args
        /home/pawels/src/binutils-gdb/gdb/main.c:1325
0x56522c41bb7f main
        /home/pawels/src/binutils-gdb/gdb/gdb.c:32
---------------------
gdbtypes.h:985: internal-error: field: Assertion `idx >= 0 && idx < num_fields
()' failed.
A problem internal to GDB has been detected,
further debugging may prove unreliable.

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[Bug c++/29985] gdbtypes.h:985: internal-error: field: Assertion `idx >= 0 && idx < num_fields ()' failed.

[pawel_sikora at zoho dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=29985

--- Comment #1 from Paweł Sikora <pawel_sikora at zoho dot com> ---
Created attachment 14570
  --> https://sourceware.org/bugzilla/attachment.cgi?id=14570&action=edit
testcase

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[Bug c++/29985] gdbtypes.h:985: internal-error: field: Assertion `idx >= 0 && idx < num_fields ()' failed.

[pawel_sikora at zoho dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=29985

--- Comment #2 from Paweł Sikora <pawel_sikora at zoho dot com> ---
looks like, fine tuned 'short nfields' (gdbtypes.h:839) is not enough for such
testcase. lldb works fine.

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[Bug c++/29985] gdbtypes.h:985: internal-error: field: Assertion `idx >= 0 && idx < num_fields ()' failed.

[tromey at sourceware dot org]

https://sourceware.org/bugzilla/show_bug.cgi?id=29985

Tom Tromey <tromey at sourceware dot org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |tromey at sourceware dot org

--- Comment #3 from Tom Tromey <tromey at sourceware dot org> ---
I feel like we've been waiting for years for this to bite.
Hilariously I think this test case would work with 'unsigned short',
but at the same time, surely someone out there wants an enum
with 65537 constants.

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[Bug c++/29985] gdbtypes.h:985: internal-error: field: Assertion `idx >= 0 && idx < num_fields ()' failed.

[pedro at palves dot net]

https://sourceware.org/bugzilla/show_bug.cgi?id=29985

Pedro Alves <pedro at palves dot net> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |pedro at palves dot net

--- Comment #4 from Pedro Alves <pedro at palves dot net> ---
Is this a real program (presumably auto generated code), or just some toolchain
testcase or some such?  "ENUM_ID::ENUM_VAL_14" kind of hints at the latter.

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[Bug c++/29985] gdbtypes.h:985: internal-error: field: Assertion `idx >= 0 && idx < num_fields ()' failed.

[pawel_sikora at zoho dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=29985

--- Comment #5 from Paweł Sikora <pawel_sikora at zoho dot com> ---
(In reply to Pedro Alves from comment #4)
> Is this a real program (presumably auto generated code), or just some
> toolchain testcase or some such?  "ENUM_ID::ENUM_VAL_14" kind of hints at
> the latter.

original program is a real hdl compiler for complex fpga technology. testcase
is reduced and anonymized to ENUM_VAL_*. one way or another, assigning 'int
idx' to 'short' will not work forever...

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[Bug c++/29985] gdbtypes.h:985: internal-error: field: Assertion `idx >= 0 && idx < num_fields ()' failed.

[tromey at sourceware dot org]

https://sourceware.org/bugzilla/show_bug.cgi?id=29985

Tom Tromey <tromey at sourceware dot org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2023-01-11
     Ever confirmed|0                           |1

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[Bug c++/29985] gdbtypes.h:985: internal-error: field: Assertion `idx >= 0 && idx < num_fields ()' failed.

[tromey at sourceware dot org]

https://sourceware.org/bugzilla/show_bug.cgi?id=29985

--- Comment #6 from Tom Tromey <tromey at sourceware dot org> ---
https://sourceware.org/pipermail/gdb-patches/2023-January/195572.html

That allows about 2 billion constants on typical arches.
We could boost it higher if we cared to.

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[Bug c++/29985] gdbtypes.h:985: internal-error: field: Assertion `idx >= 0 && idx < num_fields ()' failed.

[tromey at sourceware dot org]

https://sourceware.org/bugzilla/show_bug.cgi?id=29985

Tom Tromey <tromey at sourceware dot org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Assignee|unassigned at sourceware dot org   |tromey at sourceware dot org

--- Comment #7 from Tom Tromey <tromey at sourceware dot org> ---
Sent v2.

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[Bug c++/29985] gdbtypes.h:985: internal-error: field: Assertion `idx >= 0 && idx < num_fields ()' failed.

[pedro at palves dot net]

https://sourceware.org/bugzilla/show_bug.cgi?id=29985

--- Comment #8 from Pedro Alves <pedro at palves dot net> ---
> original program is a real hdl compiler for complex fpga technology. testcase 
> is reduced and anonymized to ENUM_VAL_*. one way or another, assigning 'int 
> idx' to 'short' will not work forever...

Thanks.  I was asking because I had the impression that GCC dropped debug info
once some limit is reached or some such.  Turns out it's worse than that -- it
fails to compile, as Tromey discovered while writing a testcase.  So I guess
you must be using Clang or some other compiler.

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[Bug c++/29985] gdbtypes.h:985: internal-error: field: Assertion `idx >= 0 && idx < num_fields ()' failed.

[tromey at sourceware dot org]

https://sourceware.org/bugzilla/show_bug.cgi?id=29985

--- Comment #9 from Tom Tromey <tromey at sourceware dot org> ---
(In reply to Pedro Alves from comment #8)

> Thanks.  I was asking because I had the impression that GCC dropped debug
> info once some limit is reached or some such.  Turns out it's worse than
> that -- it fails to compile, as Tromey discovered while writing a testcase. 
> So I guess you must be using Clang or some other compiler.

Actually it turned out that the supplied test does work in gcc, but
when I wrote one for the test suite I used a larger constant and that
caused a failure.

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[Bug c++/29985] gdbtypes.h:985: internal-error: field: Assertion `idx >= 0 && idx < num_fields ()' failed.

[pawel_sikora at zoho dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=29985

--- Comment #10 from Paweł Sikora <pawel_sikora at zoho dot com> ---
(In reply to Pedro Alves from comment #8)
> > original program is a real hdl compiler for complex fpga technology. testcase 
> > is reduced and anonymized to ENUM_VAL_*. one way or another, assigning 'int 
> > idx' to 'short' will not work forever...
> 
> Thanks.  I was asking because I had the impression that GCC dropped debug
> info once some limit is reached or some such.  Turns out it's worse than
> that -- it fails to compile, as Tromey discovered while writing a testcase. 
> So I guess you must be using Clang or some other compiler.

yes, we're currently using clang-15 (compiler/tools/thinlto/lld) +
libcxx.llvm.org + qtcreator-9.x + gdb for development and local
(x86_64)/remote(x86_64->arm64) debugging.

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[Bug c++/29985] gdbtypes.h:985: internal-error: field: Assertion `idx >= 0 && idx < num_fields ()' failed.

[cvs-commit at gcc dot gnu.org]

https://sourceware.org/bugzilla/show_bug.cgi?id=29985

--- Comment #11 from cvs-commit at gcc dot gnu.org <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Tom Tromey <tromey@sourceware.org>:

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=1775f8b3804744c22611ed0c9fd2df4f5b4d8641

commit 1775f8b3804744c22611ed0c9fd2df4f5b4d8641
Author: Tom Tromey <tromey@adacore.com>
Date:   Wed Jan 11 12:42:40 2023 -0700

    Increase size of main_type::nfields

    main_type::nfields is a 'short', and has been for many years.  PR
    c++/29985 points out that 'short' is too narrow for an enum that
    contains more than 2^15 constants.

    This patch bumps the size of 'nfields'.  To verify that the field
    isn't directly used, it is also renamed.  Note that this does not
    affect the size of main_type on x86-64 Fedora 36.  And, if it does
    have a negative effect somewhere, it's worth considering that types
    could be shrunk more drastically by using subclasses for the different
    codes.

    This is v2 of this patch, which has these changes:

    * I changed nfields to 'unsigned', per Simon's request.  I looked at
      changing all the uses, but this quickly fans out into a very large
      patch.  (One additional tweak was needed, though.)

    * I wrote a test case.  I discovered that GCC cannot compile a large
      enough C test case, so I resorted to using the DWARF assembler.
      This test doesn't reproduce the crash, but it does fail without the
      patch.

    Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=29985

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[Bug c++/29985] gdbtypes.h:985: internal-error: field: Assertion `idx >= 0 && idx < num_fields ()' failed.

[tromey at sourceware dot org]

https://sourceware.org/bugzilla/show_bug.cgi?id=29985

Tom Tromey <tromey at sourceware dot org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |14.1
         Resolution|---                         |FIXED
             Status|NEW                         |RESOLVED

--- Comment #12 from Tom Tromey <tromey at sourceware dot org> ---
Fixed.

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[Bug c++/29985] gdbtypes.h:985: internal-error: field: Assertion `idx >= 0 && idx < num_fields ()' failed.

[simon.marchi at polymtl dot ca]

https://sourceware.org/bugzilla/show_bug.cgi?id=29985

Simon Marchi <simon.marchi at polymtl dot ca> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |blue.swallow.71 at gmail dot com

--- Comment #13 from Simon Marchi <simon.marchi at polymtl dot ca> ---
*** Bug 30236 has been marked as a duplicate of this bug. ***

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