Diagnose the use of incomplete types in C++ typeid expressions

llvm-svn: 92045

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -1830,6 +1830,7 @@ def err_bad_dynamic_cast_not_polymorphic : Error<"%0 is not polymorphic">;
 // Other C++ expressions
 def err_need_header_before_typeid : Error<
   "you need to include <typeinfo> before using the 'typeid' operator">;
+def err_incomplete_typeid : Error<"'typeid' of incomplete type %0">;
 def err_static_illegal_in_new : Error<
   "the 'static' modifier for the array size is not legal in new expressions">;
 def err_array_new_needs_size : Error<

clang/lib/Sema/SemaExprCXX.cpp

@@ -37,7 +37,22 @@ Sema::ActOnCXXTypeid(SourceLocation OpLoc, SourceLocation LParenLoc,
     //   that is the operand of typeid are always ignored.
     // FIXME: Preserve type source info.
     // FIXME: Preserve the type before we stripped the cv-qualifiers?
-    TyOrExpr =GetTypeFromParser(TyOrExpr).getUnqualifiedType().getAsOpaquePtr();
+    QualType T = GetTypeFromParser(TyOrExpr);
+    if (T.isNull())
+      return ExprError();
+    
+    // C++ [expr.typeid]p4:
+    //   If the type of the type-id is a class type or a reference to a class 
+    //   type, the class shall be completely-defined.
+    QualType CheckT = T;
+    if (const ReferenceType *RefType = CheckT->getAs<ReferenceType>())
+      CheckT = RefType->getPointeeType();
+    
+    if (CheckT->getAs<RecordType>() &&
+        RequireCompleteType(OpLoc, CheckT, diag::err_incomplete_typeid))
+      return ExprError();
+    
+    TyOrExpr = T.getUnqualifiedType().getAsOpaquePtr();
   }
 
   IdentifierInfo *TypeInfoII = &PP.getIdentifierTable().get("type_info");
@@ -66,7 +81,8 @@ Sema::ActOnCXXTypeid(SourceLocation OpLoc, SourceLocation LParenLoc,
           // C++ [expr.typeid]p3:
           //   [...] If the type of the expression is a class type, the class
           //   shall be completely-defined.
-          // FIXME: implement this!
+          if (RequireCompleteType(OpLoc, T, diag::err_incomplete_typeid))
+            return ExprError();
         }
       }
 

clang/test/SemaCXX/typeid.cpp

@@ -14,3 +14,11 @@ void g()
 {
   (void)typeid(int);
 }
+
+struct X; // expected-note 3{{forward declaration}}
+
+void g1(X &x) {
+  (void)typeid(X); // expected-error{{'typeid' of incomplete type 'struct X'}}
+  (void)typeid(X&); // expected-error{{'typeid' of incomplete type 'struct X'}}
+  (void)typeid(x); // expected-error{{'typeid' of incomplete type 'struct X'}}
+}

clang/test/SemaTemplate/instantiate-expr-4.cpp

@@ -133,7 +133,7 @@ struct Throw1 {
   }
 };
 
-struct Incomplete; // expected-note{{forward}}
+struct Incomplete; // expected-note 2{{forward}}
 
 template struct Throw1<int>;
 template struct Throw1<int*>;
@@ -143,7 +143,6 @@ template struct Throw1<Incomplete*>; // expected-note{{instantiation}}
 // typeid expressions
 // ---------------------------------------------------------------------
 
-// FIXME: This should really include <typeinfo>, but we don't have that yet.
 namespace std {
   class type_info;
 }
@@ -154,7 +153,7 @@ struct TypeId0 {
     if (ptr)
       return typeid(ptr);
     else
-      return typeid(T);
+      return typeid(T); // expected-error{{'typeid' of incomplete type 'struct Incomplete'}}
   }
 };
 
@@ -163,7 +162,7 @@ struct Abstract {
 };
 
 template struct TypeId0<int>;
-template struct TypeId0<Incomplete>;
+template struct TypeId0<Incomplete>; // expected-note{{instantiation of member function}}
 template struct TypeId0<Abstract>;
 
 // ---------------------------------------------------------------------