https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101791
Bug ID: 101791 Summary: missing warning on a mismatch between scalar and array forms of new and delete Product: gcc Version: 12.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: middle-end Assignee: unassigned at gcc dot gnu.org Reporter: msebor at gcc dot gnu.org Target Milestone: --- The -Wmismatched-new-delete warning introduced in GCC 11 is meant to diagnose calls to operator delete with pointers obtained from a mismatched form or overload of operator new. A poster child for such a mismatch is the scalar form of a delete expression with an argument obtained from array new. GCC 11 diagnoses such mismatches when they involve member operators new and delete (as in g() below) but it fails to do the same for the default non-member operators (as in h()). $ cat t.C && gcc -S -Wall t.Ctypedef __SIZE_TYPE__ size_t; struct A { void* operator new (size_t); void operator delete (void*); void* operator new[] (size_t); void operator delete[] (void*); }; void f (void*); void g () { A *p = new A[7]; f (p); delete p; // -Wmismatched-new-delete (good) } void h () { int *p = new int[7]; f (p); delete p; // missing warning } t.C: In function ‘void g()’: t.C:18:10: warning: ‘static void A::operator delete(void*)’ called on pointer returned from a mismatched allocation function [-Wmismatched-new-delete] 18 | delete p; // -Wmismatched-new-delete (good) | ^ t.C:16:17: note: returned from ‘static void* A::operator new [](size_t)’ 16 | A *p = new A[7]; | ^