[PATCH] D87331: Sema: add support for `__attribute__((__swift_error__))`

[Saleem Abdulrasool via Phabricator via cfe-commits]

compnerd marked 10 inline comments as done.
compnerd added inline comments.


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Comment at: clang/include/clang/Basic/Attr.td:2122
+def SwiftError : InheritableAttr {
+  let Spellings = [GCC<"swift_error">];
+  let Args = [
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aaron.ballman wrote:
> Is this attribute also supported by GCC? It looked like it wasn't from my quick check, so I'd recommend switching the spelling to be `Clang` instead. Note, this will give you `[[clang::swift_error(...)]]` in both C and C++ as well. If you only want the GNU spelling, use `GNU`.
Ah, oops, this should be `GNU`.


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Comment at: clang/include/clang/Basic/Attr.td:2128
+  ];
+  let Subjects = SubjectList<[Function, ObjCMethod], ErrorDiag>;
+  let Documentation = [SwiftErrorDocs];
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aaron.ballman wrote:
> Should this apply to function-like things such as blocks or function pointers? If so, you should use `HasFunctionProto`.
I believe not.


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Comment at: clang/include/clang/Basic/AttrDocs.td:3394
+parameter. Currently, the error parameter is always the last parameter of type
+``NSError**`` or ``CFErrorRef*``.  Swift will remove the error parameter from
+the imported API. When calling the API, Swift will always pass a valid address
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aaron.ballman wrote:
> Canonical type or are typedefs to these types also fine? May want to mention that the type has to be cv-unqualified, but I do wonder whether something like `NSError * const *` is fine.
I am definitely not the authority on this, but I believe that the common thing is to take `NSError **` or `CFErrorRef **` by canonical name.  The cv-qualified versions, except on the outermost pointer, is something that can be treated as valid, though it is certainly extremely unusual.  I've added test cases for them as well.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D87331/new/

https://reviews.llvm.org/D87331