[libclang] Expose cursors for alias/weak attributes

[cameron314]

Summary

This patch introduces CXCursor_AliasAttr/CXCursor_WeakAttr and clang_getAliasTargetSpelling() for inspecting alias attributes via libclang.

include/clang-c/Index.h

enum CXCursorKind {
   CXCursor_CUDAConstantAttr              = 412,
   CXCursor_CUDADeviceAttr                = 413,
   CXCursor_CUDAGlobalAttr                = 414,
   CXCursor_CUDAHostAttr                  = 415,
   CXCursor_CUDASharedAttr                = 416,
   CXCursor_VisibilityAttr                = 417,
   CXCursor_DLLExport                     = 418,
   CXCursor_DLLImport                     = 419,
-  CXCursor_LastAttr                      = CXCursor_DLLImport,
+  CXCursor_WeakAttr                      = 420,
+  CXCursor_AliasAttr                     = 421,
+  CXCursor_LastAttr                      = CXCursor_AliasAttr,
 
   /* Preprocessing */
   CXCursor_PreprocessingDirective        = 500,
   CXCursor_MacroDefinition               = 501,
   CXCursor_MacroExpansion                = 502,
   CXCursor_MacroInstantiation            = CXCursor_MacroExpansion,
   CXCursor_InclusionDirective            = 503,
   CXCursor_FirstPreprocessing            = CXCursor_PreprocessingDirective,

 /**
  * \brief For cursors representing an iboutletcollection attribute,
  *  this function returns the collection element type.
  *
  */
 CINDEX_LINKAGE CXType clang_getIBOutletCollectionType(CXCursor);
 
 /**
+ * \brief For cursors representing an alias attribute,
+ *  this function returns the aliased symbol name as written.
+ */
+CINDEX_LINKAGE CXString clang_getAliasTargetSpelling(CXCursor);
+
+/**
  * @}
  */
 
 /**
  * \defgroup CINDEX_CURSOR_TRAVERSAL Traversing the AST with cursors
  *
  * These routines provide the ability to traverse the abstract syntax tree
  * using cursors.

tools/libclang/CIndex.cpp

CXString clang_getCursorKindSpelling(enum CXCursorKind Kind) {
   case CXCursor_CUDASharedAttr:
     return cxstring::createRef("attribute(shared)");
   case CXCursor_VisibilityAttr:
     return cxstring::createRef("attribute(visibility)");
   case CXCursor_DLLExport:
     return cxstring::createRef("attribute(dllexport)");
   case CXCursor_DLLImport:
     return cxstring::createRef("attribute(dllimport)");
+  case CXCursor_WeakAttr:
+    return cxstring::createRef("attribute(weak)");
+  case CXCursor_AliasAttr:
+    return cxstring::createRef("attribute(alias)");
   case CXCursor_PreprocessingDirective:
     return cxstring::createRef("preprocessing directive");
   case CXCursor_MacroDefinition:
     return cxstring::createRef("macro definition");
   case CXCursor_MacroExpansion:
     return cxstring::createRef("macro expansion");
   case CXCursor_InclusionDirective:
     return cxstring::createRef("inclusion directive");
if (PieceIndex == 0)
       SourceRange R = Pieces[PieceIndex];
       if (R.isValid())
         return cxloc::translateSourceRange(getCursorContext(C), R);
   }
   
   return clang_getNullRange();
 }
 
+CXString clang_getAliasTargetSpelling(CXCursor C) {
+  if (C.kind != CXCursor_AliasAttr)
+    return cxstring::createEmpty();
+
+  const AliasAttr *A =
+    cast<AliasAttr>(cxcursor::getCursorAttr(C));
+
+  return cxstring::createDup(A->getAliasee());
+}
+
 void clang_enableStackTraces(void) {
   llvm::sys::PrintStackTraceOnErrorSignal();
 }
 
 void clang_executeOnThread(void (*fn)(void*), void *user_data,
                            unsigned stack_size) {
   llvm::llvm_execute_on_thread(fn, user_data, stack_size);
 }

tools/libclang/CXCursor.cpp

switch (A->getKind()) {
     case attr::CUDAConstant: return CXCursor_CUDAConstantAttr;
     case attr::CUDADevice: return CXCursor_CUDADeviceAttr;
     case attr::CUDAGlobal: return CXCursor_CUDAGlobalAttr;
     case attr::CUDAHost: return CXCursor_CUDAHostAttr;
     case attr::CUDAShared: return CXCursor_CUDASharedAttr;
     case attr::Visibility: return CXCursor_VisibilityAttr;
     case attr::DLLExport: return CXCursor_DLLExport;
     case attr::DLLImport: return CXCursor_DLLImport;
+    case attr::Weak: return CXCursor_WeakAttr;
+    case attr::Alias: return CXCursor_AliasAttr;
   }
 
   return CXCursor_UnexposedAttr;
 }
 
 CXCursor cxcursor::MakeCXCursor(const Attr *A, const Decl *Parent,
                                 CXTranslationUnit TU) {
   assert(A && Parent && TU && "Invalid arguments!");