[gcc r12-8093] c++: operator new lookup [PR98249]

[gcc r12-8093] c++: operator new lookup [PR98249]

[Jason Merrill]

https://gcc.gnu.org/g:d087b59527a658a4de13febbb593edbf03339e93

commit r12-8093-gd087b59527a658a4de13febbb593edbf03339e93
Author: Jason Merrill <jason@redhat.com>
Date:   Mon Apr 11 13:06:05 2022 -0400

    c++: operator new lookup [PR98249]
    
    The standard says, as we quote in the comment just above, that if we don't
    find operator new in the allocated type, it should be looked up in the
    global scope.  This is specifically ::, not just any namespace, and we
    already give an error for an operator new declared in any other namespace.
    
            PR c++/98249
    
    gcc/cp/ChangeLog:
    
            * call.cc (build_operator_new_call): Just look in ::.
    
    gcc/testsuite/ChangeLog:
    
            * g++.dg/lookup/new3.C: New test.

Diff:
---
 gcc/cp/call.cc                     |  3 +--
 gcc/testsuite/g++.dg/lookup/new3.C | 10 ++++++++++
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/gcc/cp/call.cc b/gcc/cp/call.cc
index 73fede5a3df..3a8d7e4b131 100644
--- a/gcc/cp/call.cc
+++ b/gcc/cp/call.cc
@@ -4899,8 +4899,7 @@ build_operator_new_call (tree fnname, vec<tree, va_gc> **args,
        up in the global scope.
 
      we disregard block-scope declarations of "operator new".  */
-  fns = lookup_name (fnname, LOOK_where::NAMESPACE);
-  fns = lookup_arg_dependent (fnname, fns, *args);
+  fns = lookup_qualified_name (global_namespace, fnname);
 
   if (align_arg)
     {
diff --git a/gcc/testsuite/g++.dg/lookup/new3.C b/gcc/testsuite/g++.dg/lookup/new3.C
new file mode 100644
index 00000000000..36afb5b48e2
--- /dev/null
+++ b/gcc/testsuite/g++.dg/lookup/new3.C
@@ -0,0 +1,10 @@
+// PR c++/98249
+
+#include <new>
+struct Incomplete;
+template<class T> struct Holder { T t; };
+Holder<Incomplete> *p;
+void test() {
+    ::new (p) int;
+    new (p) int;
+}