Check whether exceptions are caught

runtime/vm/parser.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/parser.h"
 
 #include "vm/bigint_operations.h"
 #include "vm/class_finalizer.h"
 #include "vm/compiler.h"
 #include "vm/compiler_stats.h"
@@ skipping 6045 matching lines @@
       }
       TypeNode* exception_type = new TypeNode(catch_pos, *exception_param.type);
       AstNode* exception_var = new LoadLocalNode(catch_pos, catch_excp_var);
       if (!exception_type->type().IsInstantiated()) {
         EnsureExpressionTemp();
       }
       AstNode* type_cond_expr = new ComparisonNode(
           catch_pos, Token::kIS, exception_var, exception_type);
       current_block_->statements->Add(
           new IfNode(catch_pos, type_cond_expr, catch_handler, NULL));
-      ASSERT(exception_type->type().IsInstantiated());
-      handler_types.Add(*exception_param.type);
+
+      // Do not add uninstantiated types (e.g. type parameter T or
+      // generic type List<T>), since the debugger won't be able to
+      // instantiate it when walking the stack.
+      // This means that the debugger is not able to determine whether
+      // an exception is caught if the catch clause uses generic types.
+      // It will report the exception as uncaught when in fact it might
+      // be caught and handled when we unwind the stack.
+      if (exception_param.type->IsInstantiated()) {
+        handler_types.Add(*exception_param.type);
+      }
     } else {
       // No exception type exists in the catch specifier so execute the
       // catch handler code unconditionally.
       current_block_->statements->Add(catch_handler);
       generic_catch_seen = true;
       // This catch clause will handle all exceptions. We can safely forget
       // all previous catch clause types.
       handler_types.SetLength(0);
       handler_types.Add(*exception_param.type);
     }
@@ skipping 3638 matching lines @@
 void Parser::SkipQualIdent() {
   ASSERT(IsIdentifier());
   ConsumeToken();
   if (CurrentToken() == Token::kPERIOD) {
     ConsumeToken();  // Consume the kPERIOD token.
     ExpectIdentifier("identifier expected after '.'");
   }
 }
 
 }  // namespace dart