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

[Eli Zaretskii <eliz@gnu.org>]

> From: Keith Seitz <keiths@redhat.com>
> Date: Thu, 26 Mar 2026 12:17:20 -0700
> 
> This patch adds an initial try at teaching the expression parser/evaluator
> to construct temporary objects requiring construction during an inferior
> function call.
> 
> To accomplish this, I've chosen the route of modifying the parser to
> teach it that `Type(args)' is a function call when `Type' names a
> class/struct/union and is immediately followed by '(', that is, via look-
> ahead). A new parser token and grammar rule have been added to deal
> with this new production.
> 
> The real work is dispatched to `type_operation::evaluate_funcall',
> allocating memory for the temporary and finding the most suitable constructor
> with `find_overload_match'.  It then runs the inferior call, returning
> the newly constructed object.
> 
> I've included many tests covering as many corner cases as I could invent,
> and these tests are clang clean.  They also introduce no regressions on
> x86-64 Fedora 43 with GCC 15.2.1 and RHEL 9.4 with GCC 11.5.0.
> 
> Example:
> Consider a C++ frame where 'struct S { int x; S(int); ... }' is in scope
> 
> Before:
> (gdb) print S(42)
> ❌️ A syntax error in expression, near `10)'.
> 
> After:
> (gdb) print S(42)
> $1 = {x = 42}
> 
> Note that no attempt has been made to deal with templates.  Hopefully
> a follow-on patch can address that.
> ---
>  gdb/NEWS                               |   5 +
>  gdb/c-exp.y                            |  86 +++++++++--
>  gdb/eval.c                             |  55 ++++++++
>  gdb/expop.h                            |   5 +
>  gdb/testsuite/gdb.cp/infcall-ctors.cc  | 128 +++++++++++++++++
>  gdb/testsuite/gdb.cp/infcall-ctors.exp | 188 +++++++++++++++++++++++++
>  6 files changed, 457 insertions(+), 10 deletions(-)
>  create mode 100644 gdb/testsuite/gdb.cp/infcall-ctors.cc
>  create mode 100644 gdb/testsuite/gdb.cp/infcall-ctors.exp

The NEWS part is okay, thanks.

Reviewed-By: Eli Zaretskii <eliz@gnu.org>