Implement a simple hash function for libclang cursors

llvm-svn: 119876

clang/include/clang-c/Index.h

@@ -1350,6 +1350,11 @@ CINDEX_LINKAGE CXCursor clang_getTranslationUnitCursor(CXTranslationUnit);
  */
 CINDEX_LINKAGE unsigned clang_equalCursors(CXCursor, CXCursor);
 
+/**
+ * \brief Compute a hash value for the given cursor.
+ */
+CINDEX_LINKAGE unsigned clang_hashCursor(CXCursor);
+  
 /**
  * \brief Retrieve the kind of the given cursor.
  */

clang/tools/libclang/CIndex.cpp

@@ -3137,6 +3137,15 @@ unsigned clang_equalCursors(CXCursor X, CXCursor Y) {
   return X == Y;
 }
 
+unsigned clang_hashCursor(CXCursor C) {
+  unsigned Index = 0;
+  if (clang_isExpression(C.kind) || clang_isStatement(C.kind))
+    Index = 1;
+  
+  return llvm::DenseMapInfo<std::pair<unsigned, void*> >::getHashValue(
+                                        std::make_pair(C.kind, C.data[Index]));
+}
+
 unsigned clang_isInvalid(enum CXCursorKind K) {
   return K >= CXCursor_FirstInvalid && K <= CXCursor_LastInvalid;
 }

clang/tools/libclang/libclang.darwin.exports

@@ -102,6 +102,7 @@ _clang_getTranslationUnitCursor
 _clang_getTranslationUnitSpelling
 _clang_getTypeDeclaration
 _clang_getTypeKindSpelling
+_clang_hashCursor
 _clang_isCursorDefinition
 _clang_isDeclaration
 _clang_isExpression

clang/tools/libclang/libclang.exports

@@ -102,6 +102,7 @@ clang_getTranslationUnitCursor
 clang_getTranslationUnitSpelling
 clang_getTypeDeclaration
 clang_getTypeKindSpelling
+clang_hashCursor
 clang_isCursorDefinition
 clang_isDeclaration
 clang_isExpression