Allow rethrow in nested try statements

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/flags.h"
 
 #ifndef DART_PRECOMPILED_RUNTIME
 
 #include "lib/invocation_mirror.h"
@@ skipping 10218 matching lines @@
     statement = ParseJump(label_name);
     AddNodeForFinallyInlining(statement);
     ExpectSemicolon();
   } else if (token == Token::kSEMICOLON) {
     // Empty statement, nothing to do.
     ConsumeToken();
   } else if (token == Token::kRETHROW) {
     // Rethrow of current exception.
     ConsumeToken();
     ExpectSemicolon();
-    // Check if it is ok to do a rethrow.
-    if ((try_stack_ == NULL) || !try_stack_->inside_catch()) {
+    // Check if it is ok to do a rethrow. Find the inntermost enclosing
+    // catch block.
+    TryStack* try_statement = try_stack_;
+    while ((try_statement != NULL) && !try_statement->inside_catch()) {
+      try_statement = try_statement->outer_try();
+    }
+    if (try_statement == NULL) {
       ReportError(statement_pos, "rethrow of an exception is not valid here");
     }
 
     // If in async code, use :saved_exception_var and :saved_stack_trace_var
     // instead of :exception_var and :stack_trace_var.
     // These variables are bound in the block containing the try.
     // Look in the try scope directly.
-    LocalScope* scope = try_stack_->try_block()->scope->parent();
+    LocalScope* scope = try_statement->try_block()->scope->parent();
     ASSERT(scope != NULL);
     LocalVariable* excp_var;
     LocalVariable* trace_var;
     if (innermost_function().IsAsyncClosure() ||
         innermost_function().IsAsyncFunction() ||
         innermost_function().IsSyncGenClosure() ||
         innermost_function().IsSyncGenerator() ||
         innermost_function().IsAsyncGenClosure() ||
         innermost_function().IsAsyncGenerator()) {
       excp_var = scope->LocalLookupVariable(Symbols::SavedExceptionVar());
@@ skipping 4343 matching lines @@
     const ArgumentListNode& function_args,
     const LocalVariable* temp_for_last_arg,
     bool is_super_invocation) {
   UNREACHABLE();
   return NULL;
 }
 
 }  // namespace dart
 
 #endif  // DART_PRECOMPILED_RUNTIME