On 2/11/25 6:24 PM, 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");
"too large" seems misleading in this case, where it just isn't a
compile-time constant.
Why didn't the VERIFY_CONSTANT just above already reject this?
+ *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
