Commit Graph

5 Commits

Author SHA1 Message Date
Iain Sandoe f60dc3caa6 [C++20][Modules] Adjust handling of exports of namespaces and using-decls.
This adjusts the handling for:

export module  M;

export namespace {};

export namespace N {};
export using namespace N;

In the first case, we were allowing empty anonymous namespaces
as part of an extension allowing empty top-level entities, but that seems
inappropriate in this case, since the linkage would be internal for the
anonymous namespace.  We now report an error for this.

The second case was producing a warning diagnostic that this was
accepted as an extension - however the C++20 standard does allow this
as well-formed.

In the third case we keep the current practice that this is accepted with a
warning (as an extension). The C++20 standard says it's an error.

We also ensure that using decls are only applied to items with external linkage.

This adjusts error messages for exports involving redeclarations in modules to
be more specific about the reason that the decl has been rejected.

Differential Revision: https://reviews.llvm.org/D122119
2022-04-08 08:57:37 +01:00
Richard Smith bb750689d5 C++ DR2387: a variable template declared wtih (or instantiated with) a
const-qualified type is not implicitly given internal linkage. But a
variable template declared 'static' is.

This reinstates part of r359048, reverted in r359076.

llvm-svn: 359260
2019-04-26 01:51:08 +00:00
Ilya Biryukov b8292c955c Revert r359048: C++ DR2387: a variable template declared wthi
The change breaks libc++ with the follwing error:

In file included from valarray:4:
.../include/c++/v1/valarray:1062:60: error: explicit instantiation declaration of 'valarray<_Tp>' with internal linkage
_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS valarray<size_t>::valarray(size_t))
                                                           ^
.../include/c++/v1/valarray:1063:60: error: explicit instantiation declaration of '~valarray<_Tp>' with internal linkage
_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS valarray<size_t>::~valarray())

llvm-svn: 359076
2019-04-24 08:50:24 +00:00
Richard Smith eeab4518e1 C++ DR2387: a variable template declared wtih (or instantiated with) a
const-qualified type is not implicitly given internal linkage. But a
variable template declared 'static' is.

llvm-svn: 359048
2019-04-23 23:48:00 +00:00
Richard Smith e181de7f4f [c++2a] Implement semantic restrictions for 'export' declarations.
llvm-svn: 358932
2019-04-22 22:50:11 +00:00