Enable writes and reads of context slots in fast compiler.

src/compiler.cc

 // Copyright 2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 632 matching lines @@
     Visit(stmts->at(i));
     CHECK_BAILOUT;
   }
 }
 
 
 void CodeGenSelector::VisitDeclaration(Declaration* decl) {
   if (decl->fun() != NULL) {
     ProcessExpression(decl->fun(), Expression::kValue);
   }
+  Variable* var = decl->proxy()->var();
+  ASSERT_NOT_NULL(var);
+  if ((!var->is_global() && decl->fun() != NULL)) {
+    BAILOUT("Non-global function declaration");
+  }
+  if ((!var->is_global() &&
+       var->slot() != NULL &&
+       var->slot()->type() == Slot::LOOKUP)) {
+    BAILOUT("Lookup slot encountered in declaration");
+  }
 }
 
 
 void CodeGenSelector::VisitBlock(Block* stmt) {
   VisitStatements(stmt->statements());
 }
 
 
 void CodeGenSelector::VisitExpressionStatement(ExpressionStatement* stmt) {
   ProcessExpression(stmt->expression(), Expression::kEffect);
@@ skipping 124 matching lines @@
   if (rewrite != NULL) {
     // Non-global.
     Slot* slot = rewrite->AsSlot();
     if (slot == NULL) {
       // This is a variable rewritten to an explicit property access
       // on the arguments object.
       BAILOUT("non-global/non-slot variable reference");
     }
 
     Slot::Type type = slot->type();
-    if (type != Slot::PARAMETER && type != Slot::LOCAL) {
-      BAILOUT("non-parameter/non-local slot reference");
+    // When LOOKUP slots are enabled, some currently dead code
+    // implementing unary typeof will become live.
+    if (type == Slot::LOOKUP) {
+      BAILOUT("Lookup slot");
     }
   }
 }
 
 
 void CodeGenSelector::VisitLiteral(Literal* expr) {
   /* Nothing to do. */
 }
 
 
@@ skipping 67 matching lines @@
   Variable* var = expr->target()->AsVariableProxy()->AsVariable();
   Property* prop = expr->target()->AsProperty();
   if (var != NULL) {
     // All global variables are supported.
     if (!var->is_global()) {
       if (var->slot() == NULL) {
         // This is a parameter that has rewritten to an arguments access.
         BAILOUT("non-global/non-slot assignment");
       }
       Slot::Type type = var->slot()->type();
-      if (type != Slot::PARAMETER && type != Slot::LOCAL) {
-        BAILOUT("non-parameter/non-local slot assignment");
+      if (type == Slot::LOOKUP) {
+        BAILOUT("Lookup slot");
       }
     }
   } else if (prop != NULL) {
     ProcessExpression(prop->obj(), Expression::kValue);
     CHECK_BAILOUT;
     // We will only visit the key during code generation for keyed property
     // stores.  Leave its expression context uninitialized for named
     // property stores.
     Literal* lit = prop->key()->AsLiteral();
     uint32_t ignored;
@@ skipping 198 matching lines @@
 
 void CodeGenSelector::VisitThisFunction(ThisFunction* expr) {
   BAILOUT("ThisFunction");
 }
 
 #undef BAILOUT
 #undef CHECK_BAILOUT
 
 
 } }  // namespace v8::internal