Re: [PATCH v2] Add infcall support for C++ constructor-style expressions

[Kevin Buettner <kevinb@redhat.com>]

Hi Keith,

On Mon, 27 Apr 2026 09:43:08 -0700
Keith Seitz <keiths@redhat.com> wrote:

> Changes in v2:
> - Formatting fixes
> - Use c_isspace to skip whitespace in typename_token_for()
> - Merged rules for typename_for_ctor to type_exp
>   [This adds ~20 shift/reduce conflicts.]
> - Updated error message when overload-resolution is off
> - Handle static constructors and add new tests for this case
> - Added test case for when ctor is not found
> - Test early return: remove integer return status

Claude found this problem...

Using this two line program, which it named /tmp/test_c.c:

struct S { int x; };
int main() { struct S s = {42}; return s.x; }

...do:

gcc -g -o /tmp/test_c /tmp/test_c.c

Then:

kevinb-claude@claude-1:bin$ ./gdb -q
(gdb) file /tmp/test_c
Reading symbols from /tmp/test_c...
(gdb) start
Temporary breakpoint 1 at 0x40044a: file /tmp/test_c.c, line 2.
Starting program: /tmp/test_c 

This GDB supports auto-downloading debuginfo from the following URLs:
  <ima:enforcing>
  <https://debuginfod.fedoraproject.org/>
  <ima:ignore>
Enable debuginfod for this session? (y or [n]) n
Debuginfod has been disabled.
To make this setting permanent, add 'set debuginfod enabled off' to .gdbinit.
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".

Temporary breakpoint 1, main () at /tmp/test_c.c:2
2	int main() { struct S s = {42}; return s.x; }
(gdb) print typeof(struct S)(42)
/home/kevinb-claude/binutils-gdb-patch-review/gdb/eval.c:1885: internal-error: evaluate_funcall: Assertion `exp->language_defn->la_language == language_cplus' failed.
A problem internal to GDB has been detected,
further debugging may prove unreliable.
----- Backtrace -----
0x51e699 gdb_internal_backtrace_1
	/home/kevinb-claude/binutils-gdb-patch-review/gdb/bt-utils.c:122
0x51e699 _Z22gdb_internal_backtracev
	/home/kevinb-claude/binutils-gdb-patch-review/gdb/bt-utils.c:173
0x9fb874 internal_vproblem
	/home/kevinb-claude/binutils-gdb-patch-review/gdb/utils.c:434
0x9fbd38 _Z15internal_verrorPKciS0_P13__va_list_tag
	/home/kevinb-claude/binutils-gdb-patch-review/gdb/utils.c:514
0xb6cea1 _Z18internal_error_locPKciS0_z
	/home/kevinb-claude/binutils-gdb-patch-review/gdbsupport/errors.cc:57
0x67e31c _ZN4expr14type_operation16evaluate_funcallEP4typeP10expression6nosideRKSt6vectorISt10unique_ptrINS_9operationESt14default_deleteIS8_EESaISB_EE
...


Claude also complained about the 20 new shift/reduce conflicts.  It
recommends reverting to a dedicated non-terminal for TYPENAME_CTOR
instead of routing through type_exp.  (It showed some code too, but
I don't want to taint your contribution by showing you AI generated
code.)  Claude says that, if done right, that change could fix both problems
at once.

Kevin