It has been reported to that the current clang errors for, specifically,
static_assert in export contexts are a serious blocker to adoption of
modules in some cases.
There is also implementation divergence with GCC and MSVC allowing the
constructs mentioned below where clang currently rejects them with an
error.
The category of errors [for declarations in an exported context] is:
(unnamed, static_assert, empty and asm decls). These are now permitted
after P2615R1 which was approved by WG21 as a DR (and thus should be
applied to C++20 as well).
This patch removes these diagnostics and amends the testsuite accordingly.
Differential Revision: https://reviews.llvm.org/D152946
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
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
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
