Model exceptional edges from call nodes in TurboFan.

src/compiler/ast-graph-builder.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler/ast-graph-builder.h"
 
 #include "src/compiler.h"
 #include "src/compiler/ast-loop-assignment-analyzer.h"
 #include "src/compiler/control-builders.h"
 #include "src/compiler/linkage.h"
@@ skipping 309 matching lines @@
  private:
   BreakableStatement* target_;
   LoopBuilder* control_;
 };
 
 
 // Control scope implementation for a TryCatchStatement.
 class AstGraphBuilder::ControlScopeForCatch : public ControlScope {
  public:
   ControlScopeForCatch(AstGraphBuilder* owner, TryCatchBuilder* control)
-      : ControlScope(owner, 0), control_(control) {}
+      : ControlScope(owner, 0), control_(control) {
+    builder()->try_nesting_level_++;  // Increment nesting.
+  }
+  ~ControlScopeForCatch() {
+    builder()->try_nesting_level_--;  // Decrement nesting.
+  }
 
  protected:
   virtual bool Execute(Command cmd, Statement* target, Node* value) OVERRIDE {
     switch (cmd) {
       case CMD_THROW:
         control_->Throw(value);
         return true;
       case CMD_BREAK:
       case CMD_CONTINUE:
       case CMD_RETURN:
         break;
     }
     return false;
   }
 
  private:
   TryCatchBuilder* control_;
 };
 
 
 // Control scope implementation for a TryFinallyStatement.
 class AstGraphBuilder::ControlScopeForFinally : public ControlScope {
  public:
   ControlScopeForFinally(AstGraphBuilder* owner, DeferredCommands* commands,
                          TryFinallyBuilder* control)
-      : ControlScope(owner, 0), commands_(commands), control_(control) {}
+      : ControlScope(owner, 0), commands_(commands), control_(control) {
+    builder()->try_nesting_level_++;  // Increment nesting.
+  }
+  ~ControlScopeForFinally() {
+    builder()->try_nesting_level_--;  // Decrement nesting.
+  }
 
  protected:
   virtual bool Execute(Command cmd, Statement* target, Node* value) OVERRIDE {
     Node* token = commands_->RecordCommand(cmd, target, value);
     control_->LeaveTry(token);
     return true;
   }
 
  private:
   DeferredCommands* commands_;
   TryFinallyBuilder* control_;
 };
 
 
 AstGraphBuilder::AstGraphBuilder(Zone* local_zone, CompilationInfo* info,
                                  JSGraph* jsgraph, LoopAssignmentAnalysis* loop)
     : local_zone_(local_zone),
       info_(info),
       jsgraph_(jsgraph),
       environment_(nullptr),
       ast_context_(nullptr),
       globals_(0, local_zone),
       execution_control_(nullptr),
       execution_context_(nullptr),
+      try_nesting_level_(0),
       input_buffer_size_(0),
       input_buffer_(nullptr),
       exit_control_(nullptr),
       loop_assignment_analysis_(loop) {
   InitializeAstVisitor(info->isolate(), local_zone);
 }
 
 
 Node* AstGraphBuilder::GetFunctionClosure() {
   if (!function_closure_.is_set()) {
@@ skipping 88 matching lines @@
   if (FLAG_trace) {
     // TODO(mstarzinger): Only traces implicit return.
     Node* return_value = jsgraph()->UndefinedConstant();
     NewNode(javascript()->CallRuntime(Runtime::kTraceExit, 1), return_value);
   }
 
   // Return 'undefined' in case we can fall off the end.
   BuildReturn(jsgraph()->UndefinedConstant());
 
   // Finish the basic structure of the graph.
-  environment()->UpdateControlDependency(exit_control());
-  graph()->SetEnd(NewNode(common()->End()));
+  graph()->SetEnd(graph()->NewNode(common()->End(), exit_control()));
 
   return true;
 }
 
 
 // Left-hand side can only be a property, a global or a variable slot.
 enum LhsKind { VARIABLE, NAMED_PROPERTY, KEYED_PROPERTY };
 
 
 // Determine the left-hand side kind of an assignment.
@@ skipping 2446 matching lines @@
   bool has_control = op->ControlInputCount() == 1;
   bool has_effect = op->EffectInputCount() == 1;
 
   DCHECK(op->ControlInputCount() < 2);
   DCHECK(op->EffectInputCount() < 2);
 
   Node* result = NULL;
   if (!has_context && !has_framestate && !has_control && !has_effect) {
     result = graph()->NewNode(op, value_input_count, value_inputs, incomplete);
   } else {
+    bool inside_try_scope = try_nesting_level_ > 0;
     int input_count_with_deps = value_input_count;
     if (has_context) ++input_count_with_deps;
     if (has_framestate) ++input_count_with_deps;
     if (has_control) ++input_count_with_deps;
     if (has_effect) ++input_count_with_deps;
     Node** buffer = EnsureInputBufferSize(input_count_with_deps);
     memcpy(buffer, value_inputs, kPointerSize * value_input_count);
     Node** current_input = buffer + value_input_count;
     if (has_context) {
       *current_input++ = current_context();
     }
     if (has_framestate) {
       // The frame state will be inserted later. Here we misuse
       // the {DeadControl} node as a sentinel to be later overwritten
       // with the real frame state.
       *current_input++ = jsgraph()->DeadControl();
     }
     if (has_effect) {
       *current_input++ = environment_->GetEffectDependency();
     }
     if (has_control) {
       *current_input++ = environment_->GetControlDependency();
     }
     result = graph()->NewNode(op, input_count_with_deps, buffer, incomplete);
     if (has_effect) {
       environment_->UpdateEffectDependency(result);
     }
-    if (result->op()->ControlOutputCount() > 0 &&
-        !environment()->IsMarkedAsUnreachable()) {
-      environment_->UpdateControlDependency(result);
+    if (!environment()->IsMarkedAsUnreachable()) {
+      // Update the current control dependency for control-producing nodes.
+      if (NodeProperties::IsControl(result)) {
+        environment_->UpdateControlDependency(result);
+      }
+      // Add implicit exception continuation for throwing nodes.
+      if (!result->op()->HasProperty(Operator::kNoThrow) && inside_try_scope) {
+        Node* on_exception = graph()->NewNode(common()->IfException(), result);
+        environment_->UpdateControlDependency(on_exception);
+        if (FLAG_turbo_exceptions) {
+          execution_control()->ThrowValue(jsgraph()->UndefinedConstant());
+        }
+      }
+      // Add implicit success continuation for throwing nodes.
+      if (!result->op()->HasProperty(Operator::kNoThrow)) {
+        Node* on_success = graph()->NewNode(common()->IfSuccess(), result);
+        environment_->UpdateControlDependency(on_success);
+      }
     }
   }
 
   return result;
 }
 
 
 void AstGraphBuilder::UpdateControlDependencyToLeaveFunction(Node* exit) {
   if (environment()->IsMarkedAsUnreachable()) return;
   if (exit_control() != NULL) {
@@ skipping 153 matching lines @@
     // Phi does not exist yet, introduce one.
     value = NewPhi(inputs, value, control);
     value->ReplaceInput(inputs - 1, other);
   }
   return value;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8