Author: arphaman Date: Thu Oct 27 08:51:30 2016 New Revision: 285292 URL: http://llvm.org/viewvc/llvm-project?rev=285292&view=rev Log: Add documentation for the transparent_union attribute
Differential Revision: https://reviews.llvm.org/D25995 Modified: cfe/trunk/include/clang/Basic/Attr.td cfe/trunk/include/clang/Basic/AttrDocs.td Modified: cfe/trunk/include/clang/Basic/Attr.td URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/Attr.td?rev=285292&r1=285291&r2=285292&view=diff ============================================================================== --- cfe/trunk/include/clang/Basic/Attr.td (original) +++ cfe/trunk/include/clang/Basic/Attr.td Thu Oct 27 08:51:30 2016 @@ -1542,7 +1542,7 @@ def Target : InheritableAttr { def TransparentUnion : InheritableAttr { let Spellings = [GCC<"transparent_union">]; // let Subjects = SubjectList<[Record, TypedefName]>; - let Documentation = [Undocumented]; + let Documentation = [TransparentUnionDocs]; let LangOpts = [COnly]; } Modified: cfe/trunk/include/clang/Basic/AttrDocs.td URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/AttrDocs.td?rev=285292&r1=285291&r2=285292&view=diff ============================================================================== --- cfe/trunk/include/clang/Basic/AttrDocs.td (original) +++ cfe/trunk/include/clang/Basic/AttrDocs.td Thu Oct 27 08:51:30 2016 @@ -2649,3 +2649,21 @@ Conversely, ``__attribute__((xray_never_ If a function has neither of these attributes, they become subject to the XRay heuristics used to determine whether a function should be instrumented or otherwise. }]; } + +def TransparentUnionDocs : Documentation { + let Category = DocCatType; + let Content = [{ +This attribute can be applied to a union to change the behaviour of calls to +functions that have an argument with a transparent union type. The compiler +behaviour is changed in the following manner: + +- A value whose type is any member of the transparent union can be passed as an +argument without the need to cast that value. + +- The argument is passed to the function using the calling convention of the +first member of the transparent union. Consequently, all the members of the +transparent union should have the same calling convention as its first member. + +Transparent unions are not supported in C++. + }]; +} _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
