On 11/6/24 2:23 PM, Simon Martin wrote:
Even though this PR is very close to PR117101, it's not addressed by the
fix I made through r15-4958-g5821f5c8c89a05 because cxx_placement_new_fn
has the very same issue as std_placement_new_fn_p used to have.
This patch fixes the issue exactly the same, by checking the first
parameter against NULL_TREE. I considered somehow sharing code between
the two *_placement_new_fn* static functions, but it looked pointless
since the shared part ("the second parameter is the last one, and a
pointer") is unlikely to be useful elsewhere.
It seems those two functions are intended to test the exact same thing:
whether the argument is ::operator new(size_t, void*).
I think cxx_placement_new_fn should just be
return (cxx_dialect >= cxx20 && std_placement_new_fn_p (fndecl));
and some of the tests in cxx_placement_new_fn move into
std_placement_new_fn_p to accommodate callers that e.g. don't already
know we're dealing with operator new.
Successfully tested on x86_64-pc-linux-gnu.
PR c++/117463
gcc/cp/ChangeLog:
* constexpr.cc (cxx_placement_new_fn): Check first_arg against
NULL_TREE.
gcc/testsuite/ChangeLog:
* g++.dg/init/new54.C: New test.
---
gcc/cp/constexpr.cc | 3 ++-
gcc/testsuite/g++.dg/init/new54.C | 14 ++++++++++++++
2 files changed, 16 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/g++.dg/init/new54.C
diff --git a/gcc/cp/constexpr.cc b/gcc/cp/constexpr.cc
index 71e6dc4ef32..379700ca2c1 100644
--- a/gcc/cp/constexpr.cc
+++ b/gcc/cp/constexpr.cc
@@ -2334,7 +2334,8 @@ cxx_placement_new_fn (tree fndecl)
&& TREE_CODE (TREE_TYPE (fndecl)) == FUNCTION_TYPE)
{
tree first_arg = TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (fndecl)));
- if (TREE_VALUE (first_arg) == ptr_type_node
+ if (first_arg
+ && TREE_VALUE (first_arg) == ptr_type_node
&& TREE_CHAIN (first_arg) == void_list_node)
return true;
}
diff --git a/gcc/testsuite/g++.dg/init/new54.C
b/gcc/testsuite/g++.dg/init/new54.C
new file mode 100644
index 00000000000..fdff1b55f0d
--- /dev/null
+++ b/gcc/testsuite/g++.dg/init/new54.C
@@ -0,0 +1,14 @@
+// PR c++/117463
+// { dg-do "compile" { target c++20 } }
+
+struct S {};
+void *operator new[] (unsigned long, // { dg-bogus "first parameter" "" {
xfail *-*-* } }
+ void void *volatile p); // { dg-error "two or more" }
+S *fun(void *p) {
+ return new(p) S[10];
+}
+
+void *operator new (decltype(sizeof(0)), // { dg-bogus "first parameter" "" {
xfail *-*-* } }
+ void void * p); // { dg-error "two or more" }
+void *p;
+auto t = new(p) int;
