Remove all non-function-name uses of CONST_LEGACY

src/compiler/ast-graph-builder.cc

Index: src/compiler/ast-graph-builder.cc
diff --git a/src/compiler/ast-graph-builder.cc b/src/compiler/ast-graph-builder.cc
index 26d078a322c0be84dca74699ba889bcf109e13f1..e8085a34f0cd8391eaedb5f15e4914ea3a763b1a 100644
--- a/src/compiler/ast-graph-builder.cc
+++ b/src/compiler/ast-graph-builder.cc
@@ -1083,7 +1083,7 @@ void AstGraphBuilder::Visit(Expression* expr) {
 void AstGraphBuilder::VisitVariableDeclaration(VariableDeclaration* decl) {
   Variable* variable = decl->proxy()->var();
   VariableMode mode = decl->mode();
-  bool hole_init = mode == CONST || mode == CONST_LEGACY || mode == LET;
+  bool hole_init = mode == CONST || mode == LET;
   switch (variable->location()) {
     case VariableLocation::GLOBAL:
     case VariableLocation::UNALLOCATED: {
@@ -3376,15 +3376,7 @@ Node* AstGraphBuilder::BuildVariableLoad(Variable* variable,
     case VariableLocation::LOCAL: {
       // Local var, const, or let variable.
       Node* value = environment()->Lookup(variable);
-      if (mode == CONST_LEGACY) {
-        // Perform check for uninitialized legacy const variables.
-        if (value->op() == the_hole->op()) {
-          value = jsgraph()->UndefinedConstant();
-        } else if (value->opcode() == IrOpcode::kPhi) {
-          Node* undefined = jsgraph()->UndefinedConstant();
-          value = BuildHoleCheckSilent(value, undefined, value);

[Michael Starzinger, 2016/04/18 22:49:16]

There should be no more call-sites of BuildHoleCheckSilent left, can we remove
it as well (both implementation and declaration in header file)?

[adamk, 2016/04/18 23:15:34]

Done. Also removed a few analogous bits from hydrogen-instructions.h.

-        }
-      } else if (mode == LET || mode == CONST) {
+      if (mode == LET || mode == CONST) {
         // Perform check for uninitialized let/const variables.
         if (value->op() == the_hole->op()) {
           value = BuildThrowReferenceError(variable, bailout_id);
@@ -3404,11 +3396,7 @@ Node* AstGraphBuilder::BuildVariableLoad(Variable* variable,
       // TODO(titzer): initialization checks are redundant for already
       // initialized immutable context loads, but only specialization knows.
       // Maybe specializer should be a parameter to the graph builder?
-      if (mode == CONST_LEGACY) {
-        // Perform check for uninitialized legacy const variables.
-        Node* undefined = jsgraph()->UndefinedConstant();
-        value = BuildHoleCheckSilent(value, undefined, value);
-      } else if (mode == LET || mode == CONST) {
+      if (mode == LET || mode == CONST) {
         // Perform check for uninitialized let/const variables.
         value = BuildHoleCheckThenThrow(value, variable, value, bailout_id);
       }
@@ -3485,13 +3473,7 @@ Node* AstGraphBuilder::BuildVariableAssignment(
     case VariableLocation::PARAMETER:
     case VariableLocation::LOCAL:
       // Local var, const, or let variable.
-      if (mode == CONST_LEGACY && op == Token::INIT) {
-        // Perform an initialization check for legacy const variables.
-        Node* current = environment()->Lookup(variable);
-        if (current->op() != the_hole->op()) {
-          value = BuildHoleCheckSilent(current, value, current);
-        }
-      } else if (mode == CONST_LEGACY && op != Token::INIT) {
+      if (mode == CONST_LEGACY && op != Token::INIT) {
         // Non-initializing assignment to legacy const is
         // - exception in strict mode.
         // - ignored in sloppy mode.
@@ -3536,13 +3518,7 @@ Node* AstGraphBuilder::BuildVariableAssignment(
     case VariableLocation::CONTEXT: {
       // Context variable (potentially up the context chain).
       int depth = current_scope()->ContextChainLength(variable->scope());
-      if (mode == CONST_LEGACY && op == Token::INIT) {
-        // Perform an initialization check for legacy const variables.
-        const Operator* op =
-            javascript()->LoadContext(depth, variable->index(), false);
-        Node* current = NewNode(op, current_context());
-        value = BuildHoleCheckSilent(current, value, current);
-      } else if (mode == CONST_LEGACY && op != Token::INIT) {
+      if (mode == CONST_LEGACY && op != Token::INIT) {
         // Non-initializing assignment to legacy const is
         // - exception in strict mode.
         // - ignored in sloppy mode.
@@ -3580,8 +3556,6 @@ Node* AstGraphBuilder::BuildVariableAssignment(
     case VariableLocation::LOOKUP: {
       // Dynamic lookup of context variable (anywhere in the chain).
       Handle<Name> name = variable->name();
-      // TODO(mstarzinger): Use Runtime::kInitializeLegacyConstLookupSlot for
-      // initializations of const declarations.
       Node* store = BuildDynamicStore(name, value);
       PrepareFrameState(store, bailout_id, combine);
       return store;