Initial implementation of a flow-graph builder for Dart's AST.

runtime/vm/flow_graph_builder.cc

Index: runtime/vm/flow_graph_builder.cc
diff --git a/runtime/vm/flow_graph_builder.cc b/runtime/vm/flow_graph_builder.cc
new file mode 100644
index 0000000000000000000000000000000000000000..3a57ccaaaa7f5466cd53b7ef4946ba9b06c8c671
--- /dev/null
+++ b/runtime/vm/flow_graph_builder.cc
@@ -0,0 +1,904 @@
+// 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/flags.h"
+#include "vm/intermediate_language.h"
+#include "vm/os.h"
+#include "vm/parser.h"
+
+namespace dart {
+
+DEFINE_FLAG(bool, trace_bailout, false, "Print bailout from graph builder.");
+DEFINE_FLAG(bool, print_flow_graph, false, "Print the IR flow graph.");
+DECLARE_FLAG(bool, enable_type_checks);
+
+void EffectGraphVisitor::Append(const EffectGraphVisitor& other_fragment) {
+  ASSERT(is_open());
+  if (other_fragment.is_empty()) return;
+  if (is_empty()) {
+    entry_ = other_fragment.entry();
+    exit_ = other_fragment.exit();
+  } else {
+    exit()->set_successor(other_fragment.entry());
+    exit_ = other_fragment.exit();
+  }
+}
+
+
+void EffectGraphVisitor::AddInstruction(Instruction* instruction) {
+  ASSERT(is_open());
+  if (is_empty()) {
+    entry_ = exit_ = instruction;
+  } else {
+    exit()->set_successor(instruction);
+    exit_ = instruction;
+  }
+}
+
+
+void EffectGraphVisitor::Join(const TestGraphVisitor& test_fragment,
+                              const EffectGraphVisitor& true_fragment,
+                              const EffectGraphVisitor& false_fragment) {
+  // We have: a test graph fragment with zero, one, or two available exits;
+  // and a pair of effect graph fragments with zero or one available exits.
+  // We want to append the branch and (if necessary) a join node to this
+  // graph fragment.
+  ASSERT(is_open());
+
+  // 1. Connect the test to this graph.
+  Append(test_fragment);
+
+  // 2. Connect the true body to the test if it is reachable, and if so
+  // record its exit (if any).
+  Instruction* true_exit = NULL;
+  if (test_fragment.can_be_true()) {
+    TargetEntryInstr* true_entry = new TargetEntryInstr();
+    *test_fragment.true_successor_address() = true_entry;
+    true_entry->set_successor(true_fragment.entry());
+    true_exit = true_fragment.is_empty() ? true_entry : true_fragment.exit();
+  }
+
+  // 3. Connect the false body to the test if it is reachable, and if so
+  // record its exit (if any).
+  Instruction* false_exit = NULL;
+  if (test_fragment.can_be_false()) {
+    TargetEntryInstr* false_entry = new TargetEntryInstr();
+    *test_fragment.false_successor_address() = false_entry;
+    false_entry->set_successor(false_fragment.entry());
+    false_exit =
+        false_fragment.is_empty() ? false_entry : false_fragment.exit();
+  }
+
+  // 4. Set the exit of this graph depending on which bodies are reachable
+  // from the test and have open exits.
+  if (true_exit == NULL) {
+    exit_ = false_exit;  // May be NULL.
+  } else if (false_exit == NULL) {
+    exit_ = true_exit;
+  } else {
+    exit_ = new JoinEntryInstr();
+    true_exit->set_successor(exit_);
+    false_exit->set_successor(exit_);
+  }
+}
+
+
+void EffectGraphVisitor::TieLoop(const TestGraphVisitor& test_fragment,
+                                 const EffectGraphVisitor& body_fragment) {
+  // We have: a test graph fragment with zero, one, or two available exits;
+  // and an effect graph fragment with zero or one available exits.  We want
+  // to append the 'while loop' consisting of the test graph fragment as
+  // condition and the effect graph fragment as body.
+  ASSERT(is_open());
+
+  // 1. Connect the body to the test if it is reachable, and if so record
+  // its exit (if any).
+  Instruction* body_exit = NULL;
+  if (test_fragment.can_be_true()) {
+    TargetEntryInstr* body_entry = new TargetEntryInstr();
+    *test_fragment.true_successor_address() = body_entry;
+    body_entry->set_successor(body_fragment.entry());
+    body_exit = body_fragment.is_empty() ? body_entry : body_fragment.exit();
+  }
+
+  // 2. Connect the test to this graph, including the body if reachable and
+  // using a fresh join node if the body is reachable and has an open exit.
+  if (body_exit == NULL) {
+    Append(test_fragment);
+  } else {
+    JoinEntryInstr* join = new JoinEntryInstr();
+    AddInstruction(join);
+    join->set_successor(test_fragment.entry());
+    body_exit->set_successor(join);
+  }
+
+  // 3. Set the exit to the graph to be empty or a fresh target node
+  // depending on whether the false branch of the test is reachable.
+  if (test_fragment.can_be_false()) {
+    exit_ = *test_fragment.false_successor_address() = new TargetEntryInstr();
+  } else {
+    exit_ = NULL;
+  }
+}
+
+
+void TestGraphVisitor::BranchOnValue(Value* value) {
+  BranchInstr* branch = new BranchInstr(value);
+  AddInstruction(branch);
+  CloseFragment();
+  true_successor_address_ = branch->true_successor_address();
+  false_successor_address_ = branch->false_successor_address();
+}
+
+
+void EffectGraphVisitor::Bailout(const char* reason) {
+  if (FLAG_trace_bailout) {
+    OS::Print("Flow Graph Bailout: %s\n", reason);
+  }
+  bailing_out_ = true;
+  owner()->Bailout(reason);

[srdjan, 2012/02/21 14:33:41]

If 'baling_out_' is always true when owner->Bailout() != NULL, then we could
eliminate bailing_out_ field.

[Kevin Millikin (Google), 2012/02/22 13:15:42]

Done.

+}
+
+
+#define CHECK_ALIVE(bailout)                    \
+  do {                                          \
+    if (bailing_out() || !is_open()) {          \

[srdjan, 2012/02/21 14:33:41]

Question: when can it happen that we are visiting an AST while not being open?

[Kevin Millikin (Google), 2012/02/22 13:15:42]

After visiting a break, continue, return, or throw statement.  The code after is
unreachable and we shouldn't visit it.

I agree that it's not ideal that this is doing two things (check for unsupported
syntax, and check for non-live control flow).  Eventually there will be no check
for unsupported syntax.

We could also eliminate that with setjmp/longjmp handling.  I looked into it but
it seemed too complicated (to me) to get into this already big change.  Perhaps
it would be simpler for you to implement since you're familiar for how it's used
in Dart?

[srdjan, 2012/02/22 14:08:16]

Please add a comment when graph cannot be open (as described in the reply).

+      bailout;                                  \
+    }                                           \
+  } while (false)
+
+
+// <Statement> ::= Return { value:                <Expression>
+//                          inlined_finally_list: <InlinedFinally>* }
+void EffectGraphVisitor::VisitReturnNode(ReturnNode* node) {
+  ValueGraphVisitor for_value(owner(), temp_index());
+  node->value()->Visit(&for_value);
+  Append(for_value);
+  CHECK_ALIVE(return);
+
+  for (intptr_t i = 0; i < node->inlined_finally_list_length(); i++) {
+    EffectGraphVisitor for_effect(owner(), for_value.temp_index());
+    node->InlinedFinallyNodeAt(i)->Visit(&for_effect);
+    Append(for_effect);
+    CHECK_ALIVE(return);
+  }
+
+  Value* return_value = for_value.value();
+  if (FLAG_enable_type_checks) {
+    const RawFunction::Kind kind = owner()->parsed_function().function().kind();
+    // Implicit getters do not need a type check at return.
+    if (kind != RawFunction::kImplicitGetter &&
+        kind != RawFunction::kConstImplicitGetter) {
+      const AbstractType& type =
+          AbstractType::ZoneHandle(
+              owner()->parsed_function().function().result_type());
+      AssertAssignableComp* assert =
+          new AssertAssignableComp(return_value, type);
+      AddInstruction(new BindInstr(temp_index(), assert));
+      return_value = new TempValue(temp_index());
+    }
+  }
+
+  AddInstruction(new ReturnInstr(return_value));
+  CloseFragment();
+}
+
+void ValueGraphVisitor::VisitReturnNode(ReturnNode* node) { UNREACHABLE(); }
+void TestGraphVisitor::VisitReturnNode(ReturnNode* node) { UNREACHABLE(); }
+
+
+// <Expression> ::= Literal { literal: Instance }
+void EffectGraphVisitor::VisitLiteralNode(LiteralNode* node) {
+  return;
+}
+
+void ValueGraphVisitor::VisitLiteralNode(LiteralNode* node) {
+  ReturnValue(new ConstantValue(node->literal()));
+}
+
+void TestGraphVisitor::VisitLiteralNode(LiteralNode* node) {
+  BranchOnValue(new ConstantValue(node->literal()));
+}
+
+
+// Type nodes only occur as the right-hand side of instanceof comparisons,
+// and they are handled specially in that context.
+void EffectGraphVisitor::VisitTypeNode(TypeNode* node) { UNREACHABLE(); }
+void ValueGraphVisitor::VisitTypeNode(TypeNode* node) { UNREACHABLE(); }
+void TestGraphVisitor::VisitTypeNode(TypeNode* node) { UNREACHABLE(); }
+
+
+// <Expression> :: Assignable { expr:     <Expression>
+//                              type:     AbstractType
+//                              dst_name: String }
+AssertAssignableComp* EffectGraphVisitor::TranslateAssignable(
+    AssignableNode* node) {
+  ValueGraphVisitor for_value(owner(), temp_index());
+  node->expr()->Visit(&for_value);
+  Append(for_value);
+  CHECK_ALIVE(return NULL);
+
+  return new AssertAssignableComp(for_value.value(), node->type());
+}
+
+void EffectGraphVisitor::VisitAssignableNode(AssignableNode* node) {
+  AssertAssignableComp* assert = TranslateAssignable(node);
+  CHECK_ALIVE(return);
+  DoComputation(assert);
+}
+
+void ValueGraphVisitor::VisitAssignableNode(AssignableNode* node) {
+  AssertAssignableComp* assert = TranslateAssignable(node);
+  CHECK_ALIVE(return);
+  ReturnValueOf(assert);
+}
+
+
+void TestGraphVisitor::VisitAssignableNode(AssignableNode* node) {
+  AssertAssignableComp* assert = TranslateAssignable(node);
+  CHECK_ALIVE(return);
+  BranchOnValueOf(assert);
+}
+
+
+// <Expression> :: BinaryOp { kind:  Token::Kind
+//                            left:  <Expression>
+//                            right: <Expression> }
+InstanceCallComp* EffectGraphVisitor::TranslateBinaryOp(BinaryOpNode* node) {
+  if (node->kind() == Token::kAND || node->kind() == Token::kOR) {
+    Bailout("EffectGraphVisitor::VisitBinaryOpNode");
+    return NULL;
+  }
+  ValueGraphVisitor for_left_value(owner(), temp_index());
+  node->left()->Visit(&for_left_value);
+  Append(for_left_value);
+  CHECK_ALIVE(return NULL);
+  ValueGraphVisitor for_right_value(owner(), for_left_value.temp_index());
+  node->right()->Visit(&for_right_value);
+  Append(for_right_value);
+  CHECK_ALIVE(return NULL);
+  ZoneGrowableArray<Value*>* arguments = new ZoneGrowableArray<Value*>(2);
+  arguments->Add(for_left_value.value());
+  arguments->Add(for_right_value.value());
+  return new InstanceCallComp(node->Name(), arguments);
+}
+
+void EffectGraphVisitor::VisitBinaryOpNode(BinaryOpNode* node) {
+  InstanceCallComp* call = TranslateBinaryOp(node);
+  CHECK_ALIVE(return);
+  DoComputation(call);
+}
+
+void ValueGraphVisitor::VisitBinaryOpNode(BinaryOpNode* node) {
+  InstanceCallComp* call = TranslateBinaryOp(node);
+  CHECK_ALIVE(return);
+  ReturnValueOf(call);
+}
+
+void TestGraphVisitor::VisitBinaryOpNode(BinaryOpNode* node) {
+  InstanceCallComp* call = TranslateBinaryOp(node);
+  CHECK_ALIVE(return);
+  BranchOnValueOf(call);
+}
+
+
+void EffectGraphVisitor::VisitStringConcatNode(StringConcatNode* node) {
+  Bailout("EffectGraphVisitor::VisitStringConcatNode");
+}
+void ValueGraphVisitor::VisitStringConcatNode(StringConcatNode* node) {
+  Bailout("ValueGraphVisitor::VisitStringConcatNode");
+}
+void TestGraphVisitor::VisitStringConcatNode(StringConcatNode* node) {
+  Bailout("TestGraphVisitor::VisitStringConcatNode");
+}
+
+
+// <Expression> :: Comparison { kind:  Token::Kind
+//                              left:  <Expression>
+//                              right: <Expression> }
+InstanceCallComp* EffectGraphVisitor::TranslateComparison(
+    ComparisonNode* node) {
+  if (Token::IsInstanceofOperator(node->kind()) ||
+      node->kind() == Token::kEQ_STRICT ||
+      node->kind() == Token::kNE_STRICT ||
+      node->kind() == Token::kEQ ||
+      node->kind() == Token::kNE) {
+    Bailout("Some kind of comparison we don't handle yet");
+    return NULL;
+  }
+  ValueGraphVisitor for_left_value(owner(), temp_index());
+  node->left()->Visit(&for_left_value);
+  Append(for_left_value);
+  CHECK_ALIVE(return NULL);
+  ValueGraphVisitor for_right_value(owner(), for_left_value.temp_index());
+  node->right()->Visit(&for_right_value);
+  Append(for_right_value);
+  CHECK_ALIVE(return NULL);
+  ZoneGrowableArray<Value*>* arguments = new ZoneGrowableArray<Value*>(2);
+  arguments->Add(for_left_value.value());
+  arguments->Add(for_right_value.value());
+  return new InstanceCallComp(node->Name(), arguments);
+}
+
+void EffectGraphVisitor::VisitComparisonNode(ComparisonNode* node) {
+  InstanceCallComp* call = TranslateComparison(node);
+  CHECK_ALIVE(return);
+  DoComputation(call);
+}
+
+void ValueGraphVisitor::VisitComparisonNode(ComparisonNode* node) {
+  InstanceCallComp* call = TranslateComparison(node);
+  CHECK_ALIVE(return);
+  ReturnValueOf(call);
+}
+
+void TestGraphVisitor::VisitComparisonNode(ComparisonNode* node) {
+  InstanceCallComp* call = TranslateComparison(node);
+  CHECK_ALIVE(return);
+  BranchOnValueOf(call);
+}
+
+
+void EffectGraphVisitor::VisitUnaryOpNode(UnaryOpNode* node) {
+  Bailout("EffectGraphVisitor::VisitUnaryOpNode");
+}
+void ValueGraphVisitor::VisitUnaryOpNode(UnaryOpNode* node) {
+  Bailout("ValueGraphVisitor::VisitUnaryOpNode");
+}
+void TestGraphVisitor::VisitUnaryOpNode(UnaryOpNode* node) {
+  Bailout("TestGraphVisitor::VisitUnaryOpNode");
+}
+
+
+void EffectGraphVisitor::VisitIncrOpLocalNode(IncrOpLocalNode* node) {
+  Bailout("EffectGraphVisitor::VisitIncrOpLocalNode");
+}
+void ValueGraphVisitor::VisitIncrOpLocalNode(IncrOpLocalNode* node) {
+  Bailout("ValueGraphVisitor::VisitIncrOpLocalNode");
+}
+void TestGraphVisitor::VisitIncrOpLocalNode(IncrOpLocalNode* node) {
+  Bailout("TestGraphVisitor::VisitIncrOpLocalNode");
+}
+
+
+void EffectGraphVisitor::VisitIncrOpInstanceFieldNode(
+    IncrOpInstanceFieldNode* node) {
+  Bailout("EffectGraphVisitor::VisitIncrOpInstanceFieldNode");
+}
+void ValueGraphVisitor::VisitIncrOpInstanceFieldNode(
+    IncrOpInstanceFieldNode* node) {
+  Bailout("ValueGraphVisitor::VisitIncrOpInstanceFieldNode");
+}
+void TestGraphVisitor::VisitIncrOpInstanceFieldNode(
+    IncrOpInstanceFieldNode* node) {
+  Bailout("TestGraphVisitor::VisitIncrOpInstanceFieldNode");
+}
+
+
+void EffectGraphVisitor::VisitIncrOpStaticFieldNode(
+    IncrOpStaticFieldNode* node) {
+  Bailout("EffectGraphVisitor::VisitIncrOpStaticFieldNode");
+}
+void ValueGraphVisitor::VisitIncrOpStaticFieldNode(
+    IncrOpStaticFieldNode* node) {
+  Bailout("ValueGraphVisitor::VisitIncrOpStaticFieldNode");
+}
+void TestGraphVisitor::VisitIncrOpStaticFieldNode(IncrOpStaticFieldNode* node) {
+  Bailout("TestGraphVisitor::VisitIncrOpStaticFieldNode");
+}
+
+
+void EffectGraphVisitor::VisitIncrOpIndexedNode(IncrOpIndexedNode* node) {
+  Bailout("EffectGraphVisitor::VisitIncrOpIndexedNode");
+}
+void ValueGraphVisitor::VisitIncrOpIndexedNode(IncrOpIndexedNode* node) {
+  Bailout("ValueGraphVisitor::VisitIncrOpIndexedNode");
+}
+void TestGraphVisitor::VisitIncrOpIndexedNode(IncrOpIndexedNode* node) {
+  Bailout("TestGraphVisitor::VisitIncrOpIndexedNode");
+}
+
+
+void EffectGraphVisitor::VisitConditionalExprNode(ConditionalExprNode* node) {
+  Bailout("EffectGraphVisitor::VisitConditionalExprNode");
+}
+void ValueGraphVisitor::VisitConditionalExprNode(ConditionalExprNode* node) {
+  Bailout("ValueGraphVisitor::VisitConditionalExprNode");
+}
+void TestGraphVisitor::VisitConditionalExprNode(ConditionalExprNode* node) {
+  Bailout("TestGraphVisitor::VisitConditionalExprNode");
+}
+
+
+// <Statement> ::= If { condition: <Expression>
+//                      true_branch: <Sequence>
+//                      false_branch: <Sequence> }
+void EffectGraphVisitor::VisitIfNode(IfNode* node) {
+  TestGraphVisitor for_test(owner(), temp_index());
+  node->condition()->Visit(&for_test);
+  Append(for_test);
+
+  EffectGraphVisitor for_true(owner(), temp_index());
+  EffectGraphVisitor for_false(owner(), temp_index());
+
+  if (for_test.can_be_true()) node->true_branch()->Visit(&for_true);
+  if (for_test.can_be_false()) {
+    // The for_false graph fragment will be empty (default graph fragment)
+    // if we do not call Visit.
+    if (node->false_branch() != NULL) node->false_branch()->Visit(&for_false);
+  }
+  Join(for_test, for_true, for_false);
+}
+
+void ValueGraphVisitor::VisitIfNode(IfNode* node) { UNREACHABLE(); }
+void TestGraphVisitor::VisitIfNode(IfNode* node) { UNREACHABLE(); }
+
+
+void EffectGraphVisitor::VisitSwitchNode(SwitchNode* node) {
+  Bailout("EffectGraphVisitor::VisitSwitchNode");
+}
+void ValueGraphVisitor::VisitSwitchNode(SwitchNode* node) {
+  Bailout("ValueGraphVisitor::VisitSwitchNode");
+}
+void TestGraphVisitor::VisitSwitchNode(SwitchNode* node) {
+  Bailout("TestGraphVisitor::VisitSwitchNode");
+}
+
+
+void EffectGraphVisitor::VisitCaseNode(CaseNode* node) {
+  Bailout("EffectGraphVisitor::VisitCaseNode");
+}
+void ValueGraphVisitor::VisitCaseNode(CaseNode* node) {
+  Bailout("ValueGraphVisitor::VisitCaseNode");
+}
+void TestGraphVisitor::VisitCaseNode(CaseNode* node) {
+  Bailout("TestGraphVisitor::VisitCaseNode");
+}
+
+
+// <Statement> ::= While { label:     SourceLabel
+//                         condition: <Expression>
+//                         body:      <Sequence> }
+void EffectGraphVisitor::VisitWhileNode(WhileNode* node) {
+  TestGraphVisitor for_test(owner(), temp_index());
+  node->condition()->Visit(&for_test);
+
+  EffectGraphVisitor for_body(owner(), temp_index());
+  if (for_test.can_be_true()) node->body()->Visit(&for_body);
+  TieLoop(for_test, for_body);
+}
+
+void ValueGraphVisitor::VisitWhileNode(WhileNode* node) { UNREACHABLE(); }
+void TestGraphVisitor::VisitWhileNode(WhileNode* node) { UNREACHABLE(); }
+
+
+void EffectGraphVisitor::VisitDoWhileNode(DoWhileNode* node) {
+  Bailout("EffectGraphVisitor::VisitDoWhileNode");
+}
+void ValueGraphVisitor::VisitDoWhileNode(DoWhileNode* node) {
+  Bailout("ValueGraphVisitor::VisitDoWhileNode");
+}
+void TestGraphVisitor::VisitDoWhileNode(DoWhileNode* node) {
+  Bailout("TestGraphVisitor::VisitDoWhileNode");
+}
+
+
+void EffectGraphVisitor::VisitForNode(ForNode* node) {
+  Bailout("EffectGraphVisitor::VisitForNode");
+}
+void ValueGraphVisitor::VisitForNode(ForNode* node) {
+  Bailout("ValueGraphVisitor::VisitForNode");
+}
+void TestGraphVisitor::VisitForNode(ForNode* node) {
+  Bailout("TestGraphVisitor::VisitForNode");
+}
+
+
+void EffectGraphVisitor::VisitJumpNode(JumpNode* node) {
+  Bailout("EffectGraphVisitor::VisitJumpNode");
+}
+void ValueGraphVisitor::VisitJumpNode(JumpNode* node) {
+  Bailout("ValueGraphVisitor::VisitJumpNode");
+}
+void TestGraphVisitor::VisitJumpNode(JumpNode* node) {
+  Bailout("TestGraphVisitor::VisitJumpNode");
+}
+
+
+void EffectGraphVisitor::VisitArgumentListNode(ArgumentListNode* node) {
+  UNREACHABLE();
+}
+void ValueGraphVisitor::VisitArgumentListNode(ArgumentListNode* node) {
+  UNREACHABLE();
+}
+void TestGraphVisitor::VisitArgumentListNode(ArgumentListNode* node) {
+  UNREACHABLE();
+}
+
+
+void EffectGraphVisitor::VisitArrayNode(ArrayNode* node) {
+  Bailout("EffectGraphVisitor::VisitArrayNode");
+}
+void ValueGraphVisitor::VisitArrayNode(ArrayNode* node) {
+  Bailout("ValueGraphVisitor::VisitArrayNode");
+}
+void TestGraphVisitor::VisitArrayNode(ArrayNode* node) {
+  Bailout("TestGraphVisitor::VisitArrayNode");
+}
+
+
+void EffectGraphVisitor::VisitClosureNode(ClosureNode* node) {
+  Bailout("EffectGraphVisitor::VisitClosureNode");
+}
+void ValueGraphVisitor::VisitClosureNode(ClosureNode* node) {
+  Bailout("ValueGraphVisitor::VisitClosureNode");
+}
+void TestGraphVisitor::VisitClosureNode(ClosureNode* node) {
+  Bailout("TestGraphVisitor::VisitClosureNode");
+}
+
+
+void EffectGraphVisitor::VisitInstanceCallNode(InstanceCallNode* node) {
+  Bailout("EffectGraphVisitor::VisitInstanceCallNode");
+}
+void ValueGraphVisitor::VisitInstanceCallNode(InstanceCallNode* node) {
+  Bailout("ValueGraphVisitor::VisitInstanceCallNode");
+}
+void TestGraphVisitor::VisitInstanceCallNode(InstanceCallNode* node) {
+  Bailout("TestGraphVisitor::VisitInstanceCallNode");
+}
+
+
+// <Expression> ::= StaticCall { function: Function
+//                               arguments: <ArgumentList> }
+StaticCallComp* EffectGraphVisitor::TranslateStaticCall(StaticCallNode* node) {
+  ArgumentListNode* arguments = node->arguments();
+  int length = arguments->length();
+  ZoneGrowableArray<Value*>* values = new ZoneGrowableArray<Value*>(length);
+  int index = temp_index();
+  for (intptr_t i = 0; i < length; ++i) {
+    ValueGraphVisitor for_value(owner(), index);
+    arguments->NodeAt(i)->Visit(&for_value);
+    Append(for_value);
+    CHECK_ALIVE(return NULL);
+    values->Add(for_value.value());
+    index = for_value.temp_index();
+  }
+  return new StaticCallComp(node->function(), values);
+}
+
+void EffectGraphVisitor::VisitStaticCallNode(StaticCallNode* node) {
+  StaticCallComp* call = TranslateStaticCall(node);
+  CHECK_ALIVE(return);
+  DoComputation(call);
+}
+
+void ValueGraphVisitor::VisitStaticCallNode(StaticCallNode* node) {
+  StaticCallComp* call = TranslateStaticCall(node);
+  CHECK_ALIVE(return);
+  ReturnValueOf(call);
+}
+
+void TestGraphVisitor::VisitStaticCallNode(StaticCallNode* node) {
+  StaticCallComp* call = TranslateStaticCall(node);
+  CHECK_ALIVE(return);
+  BranchOnValueOf(call);
+}
+
+
+void EffectGraphVisitor::VisitClosureCallNode(ClosureCallNode* node) {
+  Bailout("EffectGraphVisitor::VisitClosureCallNode");
+}
+void ValueGraphVisitor::VisitClosureCallNode(ClosureCallNode* node) {
+  Bailout("ValueGraphVisitor::VisitClosureCallNode");
+}
+void TestGraphVisitor::VisitClosureCallNode(ClosureCallNode* node) {
+  Bailout("TestGraphVisitor::VisitClosureCallNode");
+}
+
+
+void EffectGraphVisitor::VisitCloneContextNode(CloneContextNode* node) {
+  Bailout("EffectGraphVisitor::VisitCloneContextNode");
+}
+void ValueGraphVisitor::VisitCloneContextNode(CloneContextNode* node) {
+  Bailout("ValueGraphVisitor::VisitCloneContextNode");
+}
+void TestGraphVisitor::VisitCloneContextNode(CloneContextNode* node) {
+  Bailout("TestGraphVisitor::VisitCloneContextNode");
+}
+
+
+void EffectGraphVisitor::VisitConstructorCallNode(ConstructorCallNode* node) {
+  Bailout("EffectGraphVisitor::VisitConstructorCallNode");
+}
+void ValueGraphVisitor::VisitConstructorCallNode(ConstructorCallNode* node) {
+  Bailout("ValueGraphVisitor::VisitConstructorCallNode");
+}
+void TestGraphVisitor::VisitConstructorCallNode(ConstructorCallNode* node) {
+  Bailout("TestGraphVisitor::VisitConstructorCallNode");
+}
+
+
+void EffectGraphVisitor::VisitInstanceGetterNode(InstanceGetterNode* node) {
+  Bailout("EffectGraphVisitor::VisitInstanceGetterNode");
+}
+void ValueGraphVisitor::VisitInstanceGetterNode(InstanceGetterNode* node) {
+  Bailout("ValueGraphVisitor::VisitInstanceGetterNode");
+}
+void TestGraphVisitor::VisitInstanceGetterNode(InstanceGetterNode* node) {
+  Bailout("TestGraphVisitor::VisitInstanceGetterNode");
+}
+
+
+void EffectGraphVisitor::VisitInstanceSetterNode(InstanceSetterNode* node) {
+  Bailout("EffectGraphVisitor::VisitInstanceSetterNode");
+}
+void ValueGraphVisitor::VisitInstanceSetterNode(InstanceSetterNode* node) {
+  Bailout("ValueGraphVisitor::VisitInstanceSetterNode");
+}
+void TestGraphVisitor::VisitInstanceSetterNode(InstanceSetterNode* node) {
+  Bailout("TestGraphVisitor::VisitInstanceSetterNode");
+}
+
+
+void EffectGraphVisitor::VisitStaticGetterNode(StaticGetterNode* node) {
+  Bailout("EffectGraphVisitor::VisitStaticGetterNode");
+}
+void ValueGraphVisitor::VisitStaticGetterNode(StaticGetterNode* node) {
+  Bailout("ValueGraphVisitor::VisitStaticGetterNode");
+}
+void TestGraphVisitor::VisitStaticGetterNode(StaticGetterNode* node) {
+  Bailout("TestGraphVisitor::VisitStaticGetterNode");
+}
+
+
+void EffectGraphVisitor::VisitStaticSetterNode(StaticSetterNode* node) {
+  Bailout("EffectGraphVisitor::VisitStaticSetterNode");
+}
+void ValueGraphVisitor::VisitStaticSetterNode(StaticSetterNode* node) {
+  Bailout("ValueGraphVisitor::VisitStaticSetterNode");
+}
+void TestGraphVisitor::VisitStaticSetterNode(StaticSetterNode* node) {
+  Bailout("TestGraphVisitor::VisitStaticSetterNode");
+}
+
+
+void EffectGraphVisitor::VisitNativeBodyNode(NativeBodyNode* node) {
+  Bailout("EffectGraphVisitor::VisitNativeBodyNode");
+}
+void ValueGraphVisitor::VisitNativeBodyNode(NativeBodyNode* node) {
+  Bailout("ValueGraphVisitor::VisitNativeBodyNode");
+}
+void TestGraphVisitor::VisitNativeBodyNode(NativeBodyNode* node) {
+  Bailout("TestGraphVisitor::VisitNativeBodyNode");
+}
+
+
+void EffectGraphVisitor::VisitPrimaryNode(PrimaryNode* node) {
+  Bailout("EffectGraphVisitor::VisitPrimaryNode");
+}
+void ValueGraphVisitor::VisitPrimaryNode(PrimaryNode* node) {
+  Bailout("ValueGraphVisitor::VisitPrimaryNode");
+}
+void TestGraphVisitor::VisitPrimaryNode(PrimaryNode* node) {
+  Bailout("TestGraphVisitor::VisitPrimaryNode");
+}
+
+
+// <Expression> ::= LoadLocal { local: LocalVariable }
+void EffectGraphVisitor::VisitLoadLocalNode(LoadLocalNode* node) {
+  return;
+}
+
+void ValueGraphVisitor::VisitLoadLocalNode(LoadLocalNode* node) {
+  LoadLocalComp* load = new LoadLocalComp(node->local());
+  ReturnValueOf(load);
+}
+
+void TestGraphVisitor::VisitLoadLocalNode(LoadLocalNode* node) {
+  LoadLocalComp* load = new LoadLocalComp(node->local());
+  BranchOnValueOf(load);
+}
+
+
+// <Expression> ::= StoreLocal { local: LocalVariable
+//                               value: <Expression> }
+StoreLocalComp* EffectGraphVisitor::TranslateStoreLocal(StoreLocalNode* node) {
+  ValueGraphVisitor for_value(owner(), temp_index());
+  node->value()->Visit(&for_value);
+  Append(for_value);
+  CHECK_ALIVE(return NULL);
+  return new StoreLocalComp(node->local(), for_value.value());
+}
+
+void EffectGraphVisitor::VisitStoreLocalNode(StoreLocalNode* node) {
+  StoreLocalComp* store = TranslateStoreLocal(node);
+  CHECK_ALIVE(return);
+  DoComputation(store);
+}
+
+void ValueGraphVisitor::VisitStoreLocalNode(StoreLocalNode* node) {
+  StoreLocalComp* store = TranslateStoreLocal(node);
+  CHECK_ALIVE(return);
+  ReturnValueOf(store);
+}
+
+void TestGraphVisitor::VisitStoreLocalNode(StoreLocalNode* node) {
+  StoreLocalComp* store = TranslateStoreLocal(node);
+  CHECK_ALIVE(return);
+  BranchOnValueOf(store);
+}
+
+
+void EffectGraphVisitor::VisitLoadInstanceFieldNode(
+    LoadInstanceFieldNode* node) {
+  Bailout("EffectGraphVisitor::VisitLoadInstanceFieldNode");
+}
+void ValueGraphVisitor::VisitLoadInstanceFieldNode(
+    LoadInstanceFieldNode* node) {
+  Bailout("ValueGraphVisitor::VisitLoadInstanceFieldNode");
+}
+void TestGraphVisitor::VisitLoadInstanceFieldNode(LoadInstanceFieldNode* node) {
+  Bailout("TestGraphVisitor::VisitLoadInstanceFieldNode");
+}
+
+
+void EffectGraphVisitor::VisitStoreInstanceFieldNode(
+    StoreInstanceFieldNode* node) {
+  Bailout("EffectGraphVisitor::VisitStoreInstanceFieldNode");
+}
+void ValueGraphVisitor::VisitStoreInstanceFieldNode(
+    StoreInstanceFieldNode* node) {
+  Bailout("ValueGraphVisitor::VisitStoreInstanceFieldNode");
+}
+void TestGraphVisitor::VisitStoreInstanceFieldNode(
+    StoreInstanceFieldNode* node) {
+  Bailout("TestGraphVisitor::VisitStoreInstanceFieldNode");
+}
+
+
+void EffectGraphVisitor::VisitLoadStaticFieldNode(LoadStaticFieldNode* node) {
+  Bailout("EffectGraphVisitor::VisitLoadStaticFieldNode");
+}
+void ValueGraphVisitor::VisitLoadStaticFieldNode(LoadStaticFieldNode* node) {
+  Bailout("ValueGraphVisitor::VisitLoadStaticFieldNode");
+}
+void TestGraphVisitor::VisitLoadStaticFieldNode(LoadStaticFieldNode* node) {
+  Bailout("TestGraphVisitor::VisitLoadStaticFieldNode");
+}
+
+
+void EffectGraphVisitor::VisitStoreStaticFieldNode(StoreStaticFieldNode* node) {
+  Bailout("EffectGraphVisitor::VisitStoreStaticFieldNode");
+}
+void ValueGraphVisitor::VisitStoreStaticFieldNode(StoreStaticFieldNode* node) {
+  Bailout("ValueGraphVisitor::VisitStoreStaticFieldNode");
+}
+void TestGraphVisitor::VisitStoreStaticFieldNode(StoreStaticFieldNode* node) {
+  Bailout("TestGraphVisitor::VisitStoreStaticFieldNode");
+}
+
+
+void EffectGraphVisitor::VisitLoadIndexedNode(LoadIndexedNode* node) {
+  Bailout("EffectGraphVisitor::VisitLoadIndexedNode");
+}
+void ValueGraphVisitor::VisitLoadIndexedNode(LoadIndexedNode* node) {
+  Bailout("ValueGraphVisitor::VisitLoadIndexedNode");
+}
+void TestGraphVisitor::VisitLoadIndexedNode(LoadIndexedNode* node) {
+  Bailout("TestGraphVisitor::VisitLoadIndexedNode");
+}
+
+
+void EffectGraphVisitor::VisitStoreIndexedNode(StoreIndexedNode* node) {
+  Bailout("EffectGraphVisitor::VisitStoreIndexedNode");
+}
+void ValueGraphVisitor::VisitStoreIndexedNode(StoreIndexedNode* node) {
+  Bailout("ValueGraphVisitor::VisitStoreIndexedNode");
+}
+void TestGraphVisitor::VisitStoreIndexedNode(StoreIndexedNode* node) {
+  Bailout("TestGraphVisitor::VisitStoreIndexedNode");
+}
+
+
+// <Statement> ::= Sequence { scope: LocalScope
+//                            nodes: <Statement>*
+//                            label: SourceLabel }
+void EffectGraphVisitor::VisitSequenceNode(SequenceNode* node) {
+  if (node->scope() != NULL && node->scope()->num_context_variables() != 0) {
+    Bailout("Sequence needs a context.  Gotta have a context.");
+  }
+  for (intptr_t i = 0; i < node->length(); ++i) {
+    EffectGraphVisitor for_effect(owner(), temp_index());
+    node->NodeAt(i)->Visit(&for_effect);
+    Append(for_effect);
+    CHECK_ALIVE(return);
+  }
+}
+
+void ValueGraphVisitor::VisitSequenceNode(SequenceNode* node) { UNREACHABLE(); }
+void TestGraphVisitor::VisitSequenceNode(SequenceNode* node) { UNREACHABLE(); }
+
+
+void EffectGraphVisitor::VisitCatchClauseNode(CatchClauseNode* node) {
+  Bailout("EffectGraphVisitor::VisitCatchClauseNode");
+}
+void ValueGraphVisitor::VisitCatchClauseNode(CatchClauseNode* node) {
+  Bailout("ValueGraphVisitor::VisitCatchClauseNode");
+}
+void TestGraphVisitor::VisitCatchClauseNode(CatchClauseNode* node) {
+  Bailout("TestGraphVisitor::VisitCatchClauseNode");
+}
+
+
+void EffectGraphVisitor::VisitTryCatchNode(TryCatchNode* node) {
+  Bailout("EffectGraphVisitor::VisitTryCatchNode");
+}
+void ValueGraphVisitor::VisitTryCatchNode(TryCatchNode* node) {
+  Bailout("ValueGraphVisitor::VisitTryCatchNode");
+}
+void TestGraphVisitor::VisitTryCatchNode(TryCatchNode* node) {
+  Bailout("TestGraphVisitor::VisitTryCatchNode");
+}
+
+
+void EffectGraphVisitor::VisitThrowNode(ThrowNode* node) {
+  Bailout("EffectGraphVisitor::VisitThrowNode");
+}
+void ValueGraphVisitor::VisitThrowNode(ThrowNode* node) {
+  Bailout("ValueGraphVisitor::VisitThrowNode");
+}
+void TestGraphVisitor::VisitThrowNode(ThrowNode* node) {
+  Bailout("TestGraphVisitor::VisitThrowNode");
+}
+
+
+void EffectGraphVisitor::VisitInlinedFinallyNode(InlinedFinallyNode* node) {
+  Bailout("EffectGraphVisitor::VisitInlinedFinallyNode");
+}
+void ValueGraphVisitor::VisitInlinedFinallyNode(InlinedFinallyNode* node) {
+  Bailout("ValueGraphVisitor::VisitInlinedFinallyNode");
+}
+void TestGraphVisitor::VisitInlinedFinallyNode(InlinedFinallyNode* node) {
+  Bailout("TestGraphVisitor::VisitInlinedFinallyNode");
+}
+
+
+void FlowGraphBuilder::TraceBailout() const {
+  if (FLAG_trace_bailout && bailout_reason_ != NULL) {
+    OS::Print("Failed: %s in %s\n",
+              bailout_reason_,
+              parsed_function().function().ToFullyQualifiedCString());
+  }
+}
+
+
+void FlowGraphBuilder::PrintGraph() const {
+  if (!FLAG_print_flow_graph || bailout_reason_ != NULL) return;
+
+  OS::Print("==== %s\n",
+            parsed_function().function().ToFullyQualifiedCString());
+
+  for (intptr_t i = postorder_.length() - 1; i >= 0; --i) {
+    OS::Print("%8d: ", postorder_.length() - i);
+    postorder_[i]->Print(i, postorder_);
+    OS::Print("\n");
+  }
+  OS::Print("\n");
+}
+
+
+void FlowGraphBuilder::BuildGraph() {
+  EffectGraphVisitor for_effect(this, 0);
+  parsed_function().node_sequence()->Visit(&for_effect);
+  TraceBailout();
+  if (bailout_reason_ == NULL && for_effect.entry() != NULL) {

[srdjan, 2012/02/22 00:41:34]

Another "standard" in the VM code is to use parentheses to make precedence more
explicit, i.e., ((A == null) && (B ==null)). Applies to other comparisons above.

[Kevin Millikin (Google), 2012/02/22 13:15:42]

Done.

+    for_effect.entry()->Postorder(&postorder_);
+  }
+  PrintGraph();
+}
+
+}  // namespace dart