Commit Graph

13 Commits

Author SHA1 Message Date
Alan Zhao 6f2b347895 Add missing `struct` keyword to the test p2-2.cpp
While working on D53847, I noticed that this test would fail once we
started recognizing the types in the modified `export` statement [0].
The tests would fail because Clang would emit a "declaration does not
declare anything" diagnostic instead of the expected namespace scope
diagnostic.

I believe that the test is currently incorrectly passing because Clang
doesn't parse the type and therefore doesn't treat the statement as a
declaration. My understanding is that the intention of this test case is
that it wants to export a `struct` type, which I believe requires a
`struct` keyword, even for types with template parameters. With this
change, the only error with these two statements should be the
namespace scope issue.

[0]: https://reviews.llvm.org/D53847?id=462032#inline-1297053

Reviewed By: erichkeane

Differential Revision: https://reviews.llvm.org/D134578
2022-09-28 09:48:00 -07:00
Chuanqi Xu 9c04851cf5 [C++20] [Module] Support reachable definition initially/partially
This patch introduces a new kind of ModuleOwnershipKind as
ReachableWhenImported. This intended the status for reachable described
at: https://eel.is/c++draft/module.reach#3.

Note that this patch is not intended to support all semantics about
reachable semantics. For example, this patch didn't implement discarded
declarations in GMF. (https://eel.is/c++draft/module.global.frag#3).

This fixes: https://bugs.llvm.org/show_bug.cgi?id=52281 and
https://godbolt.org/z/81f3ocjfW.

Reviewed By: rsmith, iains

Differential Revision: https://reviews.llvm.org/D113545
2022-06-29 12:48:48 +08:00
Chuanqi Xu 7a541406b5 Revert "[C++20] [Modules] Implement Reachable initiallly"
This reverts commit a223ba0a69.

The previous commit don't contain additional information, which is bad.
2022-06-29 12:43:26 +08:00
Chuanqi Xu a223ba0a69 [C++20] [Modules] Implement Reachable initiallly 2022-06-29 12:32:31 +08:00
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
Chuanqi Xu 5c1f7b296a [C++20] [Modules] Only check decls under namespace scope in CheckRedeclarationExported
Since only the decls inhabit in a namespace scope could be exported, it
is not meaningful to check it in CheckRedeclarationExported, which
implements [module.interface]/p6.

Reviewed By: urnathan

Differential Revision: https://reviews.llvm.org/D118120
2022-01-26 10:54:52 +08:00
Chuanqi Xu 3a3af2bbc9 [C++20] [Module] fix bug 47716 and implement [module.interface]/p6
This fixes bug 47716.

According to [module.interface]p2, it is meaningless to export an entity
which is not in namespace scope.
The reason why the compiler crashes is that the compiler missed
ExportDecl when the compiler traverse the subclass of DeclContext. So
here is the crash.

Also, the patch implements [module.interface]p6 in
Sema::CheckRedeclaration* functions.

Reviewed By: aaron.ballman, urnathan

Differential Revision: https://reviews.llvm.org/D112903
2022-01-24 10:25:25 +08:00
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 3ac3e9ce04 Add missing diagnostic for anonymous struct/union definitions that don't
introduce any names.

llvm-svn: 359051
2019-04-24 00:08:02 +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
Richard Smith a5bbbfef15 [c++2a] Add semantic support for private module fragments.
llvm-svn: 358713
2019-04-18 21:12:54 +00:00