Ping.
On Tue, Feb 11, 2025 at 06:24:32PM -0500, Marek Polacek wrote:
> Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk?
>
> -- >8 --
> Here we ICE since r11-7740 because we no longer say that (long)&a
> (where a is a global var) is non_constant_p. So VERIFY_CONSTANT
> does not return and we crash on tree_to_uhwi. We should check
> tree_fits_uhwi_p before calling tree_to_uhwi.
>
> PR c++/118775
>
> gcc/cp/ChangeLog:
>
> * constexpr.cc (cxx_eval_call_expression): Check tree_fits_uhwi_p.
>
> gcc/testsuite/ChangeLog:
>
> * g++.dg/cpp2a/constexpr-new24.C: New test.
> * g++.dg/cpp2a/constexpr-new25.C: New test.
> ---
> gcc/cp/constexpr.cc | 7 +++++
> gcc/testsuite/g++.dg/cpp2a/constexpr-new24.C | 25 ++++++++++++++++++
> gcc/testsuite/g++.dg/cpp2a/constexpr-new25.C | 27 ++++++++++++++++++++
> 3 files changed, 59 insertions(+)
> create mode 100644 gcc/testsuite/g++.dg/cpp2a/constexpr-new24.C
> create mode 100644 gcc/testsuite/g++.dg/cpp2a/constexpr-new25.C
>
> diff --git a/gcc/cp/constexpr.cc b/gcc/cp/constexpr.cc
> index f142dd32bc8..f8f9a9df1a2 100644
> --- a/gcc/cp/constexpr.cc
> +++ b/gcc/cp/constexpr.cc
> @@ -2909,6 +2909,13 @@ cxx_eval_call_expression (const constexpr_ctx *ctx,
> tree t,
> gcc_assert (arg0);
> if (new_op_p)
> {
> + if (!tree_fits_uhwi_p (arg0))
> + {
> + if (!ctx->quiet)
> + error_at (loc, "cannot allocate array: size too large");
> + *non_constant_p = true;
> + return t;
> + }
> tree type = build_array_type_nelts (char_type_node,
> tree_to_uhwi (arg0));
> tree var = build_decl (loc, VAR_DECL,
> diff --git a/gcc/testsuite/g++.dg/cpp2a/constexpr-new24.C
> b/gcc/testsuite/g++.dg/cpp2a/constexpr-new24.C
> new file mode 100644
> index 00000000000..debb7f0f5c4
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/cpp2a/constexpr-new24.C
> @@ -0,0 +1,25 @@
> +// PR c++/118775
> +// { dg-do compile { target c++20 } }
> +
> +int a;
> +
> +constexpr char *
> +f1 ()
> +{
> + constexpr auto p = new char[(long int) &a]; // { dg-error "size too large"
> }
> + return p;
> +}
> +
> +constexpr char *
> +f2 ()
> +{
> + auto p = new char[(long int) &a]; // { dg-error "size too large" }
> + return p;
> +}
> +
> +void
> +g ()
> +{
> + auto r1 = f2 ();
> + constexpr auto r2 = f2 (); // { dg-message "in .constexpr. expansion" }
> +}
> diff --git a/gcc/testsuite/g++.dg/cpp2a/constexpr-new25.C
> b/gcc/testsuite/g++.dg/cpp2a/constexpr-new25.C
> new file mode 100644
> index 00000000000..91c0318abd8
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/cpp2a/constexpr-new25.C
> @@ -0,0 +1,27 @@
> +// PR c++/118775
> +// { dg-do compile { target c++20 } }
> +
> +namespace std {
> +struct __uniq_ptr_impl {
> + constexpr __uniq_ptr_impl(char *) {}
> +};
> +template <typename> struct unique_ptr {
> + __uniq_ptr_impl _M_t;
> + constexpr ~unique_ptr() {}
> +};
> +template <typename> struct _MakeUniq;
> +template <typename _Tp> struct _MakeUniq<_Tp[]> {
> + typedef unique_ptr<_Tp[]> __array;
> +};
> +template <typename _Tp> using __unique_ptr_array_t = _MakeUniq<_Tp>::__array;
> +constexpr __unique_ptr_array_t<char[]> make_unique(long __num) {
> + return unique_ptr<char[]>(new char[__num]);
> +}
> +} // namespace std
> +int a;
> +int
> +main ()
> +{
> + std::unique_ptr p = std::make_unique((long)&a);
> + constexpr std::unique_ptr p2 = std::make_unique((long)&a); // { dg-error
> "conversion" }
> +}
>
> base-commit: 299a8e2dc667e795991bc439d2cad5ea5bd379e2
> --
> 2.48.1
>
Marek
