[index/AST] Determine if a typedef shares a name and spelling location with its underlying tag type

In such a case, as when using the NS_ENUM macro, for indexing purposes treat the typedef as 'transparent',
meaning we treat its references as symbols of the underlying tag symbol.
Also provide a libclang API to check for such typedefs.

llvm-svn: 298392

1 files changed, 10 insertions, 0 deletions

diff --git a/clang/include/clang-c/Index.h b/clang/include/clang-c/Index.h
index d466fce8515..208da7d0f42 100644
--- a/clang/include/clang-c/Index.h
+++ b/clang/include/clang-c/Index.h
@@ -3437,6 +3437,16 @@ CINDEX_LINKAGE long long clang_getArraySize(CXType T);
 CINDEX_LINKAGE CXType clang_Type_getNamedType(CXType T);
 
 /**
+ * \brief Determine if a typedef is 'transparent' tag.
+ *
+ * A typedef is considered 'transparent' if it shares a name and spelling
+ * location with its underlying tag type, as is the case with the NS_ENUM macro.
+ *
+ * \returns non-zero if transparent and zero otherwise.
+ */
+CINDEX_LINKAGE unsigned clang_Type_isTransparentTagTypedef(CXType T);
+
+/**
  * \brief List the possible error codes for \c clang_Type_getSizeOf,
  *   \c clang_Type_getAlignOf, \c clang_Type_getOffsetOf and
  *   \c clang_Cursor_getOffsetOf.