https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67345
Bug ID: 67345
Summary: -Woverloaded-virtual false negative: Does not warn on
overloaded virtual function
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: major
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: EisahLee at gmx dot de
Target Milestone: ---
Created attachment 36251
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=36251&action=edit
Example program to demonstrate missing warning.
See example program in attachment.
Crucial steps to reproduce code that exhibits the bug:
'MyDerived' defines 'virtual frob(int, int)', and hides the non-virtual
'frob(int)' of 'MyBase'.
Evidence that there is actually some "hiding" going on:
- Empirical: If we change 'frob(int)' of 'MyBase' to virtual, then g++ issues a
warning.
- Reported on stackoverflow, other people ran into that issue before me:
http://stackoverflow.com/a/6035884/3070326
Expected behaviour from g++: Warn that 'MyDerived::frob(int,int)' hides
'MyBase::frob(int)', although this might be unintuitive for C++ newbies. (Just
like the warning for "a < b < c".)
Actual behaviour: 'frob(int)' is inaccessible when the static type is
'MyDerived'. This means one of the following happens:
- If 'frob(int)' is not called, then g++ silently ignores the situation. BAD! I
want a warning, telling me that 'frob(int, int)' is at fault. (Example:
Attached file, verbatim)
- Otherwise, g++ only lists 'MyDerived::frob(int, int)' as candidate. BAD! I
want another candidate ('MyBase::frob(int)') with the explanation that overload
resolution does not operate across namespaces. (Example: Attached file, with
the 'derived.frob(23);' uncommented.)
Meta-info:
"gcc version 4.9.3 (Debian 4.9.3-3) "
As there is no similar bug report, I assume it has not been fixed by a more
recent version anyway.
