Ensure that we never try to split range at its end position.

runtime/vm/flow_graph_builder.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/flow_graph_builder.h"
 
 #include "vm/ast_printer.h"
 #include "vm/bit_vector.h"
 #include "vm/code_descriptors.h"
 #include "vm/dart_entry.h"
@@ skipping 2618 matching lines @@
     }
   }
 
   // 2. Process normal instructions.
   for (ForwardInstructionIterator it(block_entry); !it.Done(); it.Advance()) {
     Instruction* current = it.Current();
     // Attach current environment to the instruction.
     // TODO(fschneider): Currently each instruction gets a full copy of the
     // environment. This should be optimized: Only instructions that can
     // deoptimize should have uses of the environment values.
-    current->set_env(new Environment(*env, fixed_parameter_count));
+    if (!current->IsReturn()) {

[Florian Schneider, 2012/07/31 15:31:59]

This is not part of the fix. I'd remove it.

[Vyacheslav Egorov (Google), 2012/07/31 16:18:49]

Done.

+      current->set_env(new Environment(*env, fixed_parameter_count));
+    }
 
     // 2a. Handle uses:
     // Update expression stack environment for each use.
     // For each use of a LoadLocal or StoreLocal: Replace it with the value
     // from the environment.
     for (intptr_t i = 0; i < current->InputCount(); ++i) {
       Value* v = current->InputAt(i);
       if (!v->IsUse()) continue;
       // Update expression stack.
       ASSERT(env->length() > var_count);
@@ skipping 100 matching lines @@
   char* chars = reinterpret_cast<char*>(
       Isolate::Current()->current_zone()->Allocate(len));
   OS::SNPrint(chars, len, kFormat, function_name, reason);
   const Error& error = Error::Handle(
       LanguageError::New(String::Handle(String::New(chars))));
   Isolate::Current()->long_jump_base()->Jump(1, error);
 }
 
 
 }  // namespace dart