https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91127
Bug ID: 91127
Summary: Incorrect checking of nonnull attribute with argument
to a constructor of class with a virtual base
Product: gcc
Version: 9.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: frankhb1989 at gmail dot com
Target Milestone: ---
Case:
struct B
{};
struct C : virtual B
{
__attribute__((nonnull(2))) C(const char*);
};
a.cc:6:43: warning: 'nonnull' attribute argument value '2' refers to parameter
type 'int' [-Wattributes]
6 | __attribute__((nonnull(2))) C(const char*);
| ^
Removal of `virtual` makes it works. Use of `__attribute__((nonnull))` (with no
argument `2`) also works.
Clang++ 8 seems OK with or without `virtual`.
Note it is worse in old versions of the compiler, e.g. with G++ 7.1:
a.cc:6:43: error: nonnull argument references non-pointer operand (argument 1,
operand 2)
__attribute__((nonnull(2))) C(const char*);
^
The change in PR 87541 has made the diagnostics more explicit. Not sure whether
the change from error to warning is intended, though.
