https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115821
Bug ID: 115821
Summary: -Wc++-compat should warn about anonymous struct
Product: gcc
Version: 15.0
Status: UNCONFIRMED
Keywords: diagnostic, documentation
Severity: enhancement
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: pinskia at gcc dot gnu.org
Target Milestone: ---
The documentation for -Wc++-compat says:
Warn about ISO C constructs that are outside of the common subset of ISO C and
ISO C++, e.g. request for implicit conversion from void * to a pointer to
non-void type.
Which makes me think that it should warn about anonymous structs (which is
valid for ISO C but not for ISO C++).
Either we should refine the documentation for -Wc++-compat to talk about GNU
extensions in both (well it is part of C11) or warn in this case.
testcase:
```
struct foo{
struct{
const int i;
};
};
```
I don't have a preference on which way this should be fixed though.
Note we might want to warn on qualifiers on anonymous unions in a similar
fashion (see PR 115820) unless we change the documentation to talk about GNU
extensions here.
