https://gcc.gnu.org/g:fde96e8205f343e6471a11cc9def967bb5dd5362
commit r15-1946-gfde96e8205f343e6471a11cc9def967bb5dd5362
Author: Marek Polacek <pola...@redhat.com>
Date: Tue Jul 2 15:22:39 2024 -0400
c++: array new with value-initialization [PR115645]
This extends the r11-5179 fix which doesn't work with multidimensional
arrays. In particular,
struct S {
explicit S() { }
};
auto p = new S[1][1]();
should not say "converting to S from initializer list would use
explicit constructor" because there's no {}. However, since we
went into the block where we create a {}, we got confused. We
should not have gotten there but we did because array_p was true.
This patch refines the check once more.
PR c++/115645
gcc/cp/ChangeLog:
* init.cc (build_new): Don't do any deduction for arrays with
bounds if it's value-initialized.
gcc/testsuite/ChangeLog:
* g++.dg/expr/anew7.C: New test.
Diff:
---
gcc/cp/init.cc | 12 ++++++++----
gcc/testsuite/g++.dg/expr/anew7.C | 13 +++++++++++++
2 files changed, 21 insertions(+), 4 deletions(-)
diff --git a/gcc/cp/init.cc b/gcc/cp/init.cc
index 826a31c4a84e..e9561c146d7b 100644
--- a/gcc/cp/init.cc
+++ b/gcc/cp/init.cc
@@ -4005,10 +4005,14 @@ build_new (location_t loc, vec<tree, va_gc>
**placement, tree type,
/* P1009: Array size deduction in new-expressions. */
const bool array_p = TREE_CODE (type) == ARRAY_TYPE;
if (*init
- /* If ARRAY_P, we have to deduce the array bound. For C++20 paren-init,
- we have to process the parenthesized-list. But don't do it for (),
- which is value-initialization, and INIT should stay empty. */
- && (array_p || (cxx_dialect >= cxx20 && nelts && !(*init)->is_empty ())))
+ /* If the array didn't specify its bound, we have to deduce it. */
+ && ((array_p && !TYPE_DOMAIN (type))
+ /* For C++20 array with parenthesized-init, we have to process
+ the parenthesized-list. But don't do it for (), which is
+ value-initialization, and INIT should stay empty. */
+ || (cxx_dialect >= cxx20
+ && (array_p || nelts)
+ && !(*init)->is_empty ())))
{
/* This means we have 'new T[]()'. */
if ((*init)->is_empty ())
diff --git a/gcc/testsuite/g++.dg/expr/anew7.C
b/gcc/testsuite/g++.dg/expr/anew7.C
new file mode 100644
index 000000000000..ead5536e1093
--- /dev/null
+++ b/gcc/testsuite/g++.dg/expr/anew7.C
@@ -0,0 +1,13 @@
+// PR c++/115645
+// { dg-do compile { target c++11 } }
+
+struct S {
+ explicit S() { }
+};
+
+auto p = new S[1][1]();
+auto q = new S[1][1]{}; // { dg-error "explicit" }
+auto r = new S[1]();
+auto s = new S[1]{}; // { dg-error "explicit" }
+auto t = new S[1][1][1]();
+auto u = new S[1][1][1]{}; // { dg-error "explicit" }
