More auto work.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@74339 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/clang/Basic/DiagnosticSemaKinds.td b/include/clang/Basic/DiagnosticSemaKinds.td
index e16286f..7e8c34c 100644
--- a/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/include/clang/Basic/DiagnosticSemaKinds.td
@@ -403,6 +403,9 @@
   "variable %0 declared with 'auto' type cannot appear in its own initializer">;
 def err_illegal_decl_array_of_auto : Error<
   "'%0' declared as array of 'auto'">;
+def err_auto_not_allowed : Error<
+  "'auto' not allowed in %select{function prototype|struct member|union member"
+  "|class member|exception declaration|template parameter|block literal}0">;
   
 // Objective-C++
 def err_objc_decls_may_only_appear_in_global_scope : Error<
diff --git a/lib/Sema/SemaType.cpp b/lib/Sema/SemaType.cpp
index 35cfce2..c6bcdc3 100644
--- a/lib/Sema/SemaType.cpp
+++ b/lib/Sema/SemaType.cpp
@@ -807,6 +807,52 @@
     break;
   }
 
+  if (T == Context.UndeducedAutoTy) {
+    int Error = -1;
+    
+    switch (D.getContext()) {
+    case Declarator::KNRTypeListContext:
+      assert(0 && "K&R type lists aren't allowed in C++");
+      break;
+    default:
+      printf("context: %d\n", D.getContext());
+      assert(0);
+    case Declarator::PrototypeContext:
+      Error = 0; // Function prototype
+      break;
+    case Declarator::MemberContext:
+      switch (cast<TagDecl>(CurContext)->getTagKind()) {
+      case TagDecl::TK_enum: assert(0 && "unhandled tag kind"); break;
+      case TagDecl::TK_struct: Error = 1; /* Struct member */ break;
+      case TagDecl::TK_union:  Error = 2; /* Union member */ break;
+      case TagDecl::TK_class:  Error = 3; /* Class member */ break;
+      }  
+      break;
+    case Declarator::CXXCatchContext:
+      Error = 4; // Exception declaration
+      break;
+    case Declarator::TemplateParamContext:
+      Error = 5; // Template parameter
+      break;
+    case Declarator::BlockLiteralContext:
+      Error = 6;  // Block literal
+      break;
+    case Declarator::FileContext:
+    case Declarator::BlockContext:
+    case Declarator::ForContext:
+    case Declarator::ConditionContext:
+    case Declarator::TypeNameContext:
+      break;
+    }
+
+    if (Error != -1) {
+      Diag(D.getDeclSpec().getTypeSpecTypeLoc(), diag::err_auto_not_allowed)
+        << Error;
+      T = Context.IntTy;
+      D.setInvalidType(true);
+    }
+  }
+  
   // The name we're declaring, if any.
   DeclarationName Name;
   if (D.getIdentifier())
diff --git a/test/CXX/dcl.dcl/dcl.spec/dcl.type/dcl.spec.auto/p2.cpp b/test/CXX/dcl.dcl/dcl.spec/dcl.type/dcl.spec.auto/p2.cpp
index 8f5058e..fa3101c 100644
--- a/test/CXX/dcl.dcl/dcl.spec/dcl.type/dcl.spec.auto/p2.cpp
+++ b/test/CXX/dcl.dcl/dcl.spec/dcl.type/dcl.spec.auto/p2.cpp
@@ -2,3 +2,12 @@
 void f() {
   auto a = a; // expected-error{{variable 'a' declared with 'auto' type cannot appear in its own initializer}}
 }
+
+struct S { auto a; }; // expected-error{{'auto' not allowed in struct member}}
+
+void f(auto a) // expected-error{{'auto' not allowed in function prototype}}
+{
+  try { } catch (auto a) {  } // expected-error{{'auto' not allowed in exception declaration}}
+}
+
+template <auto a = 10> class C { }; // expected-error{{'auto' not allowed in template parameter}}