Fix some defects identifies by Coverity Prevent. All are false...

src/ia32/codegen-ia32.cc

 // Copyright 2006-2009 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 3839 matching lines @@
       __ mov(tmp.reg(), FieldOperand(tmp.reg(), JSFunction::kContextOffset));
       context = tmp.reg();
     }
     // If no outer scope calls eval, we do not need to check more
     // context extensions.  If we have reached an eval scope, we check
     // all extensions from this point.
     if (!s->outer_scope_calls_eval() || s->is_eval_scope()) break;
     s = s->outer_scope();
   }
 
-  if (s->is_eval_scope()) {
+  if (s != NULL && s->is_eval_scope()) {
     // Loop up the context chain.  There is no frame effect so it is
     // safe to use raw labels here.
     Label next, fast;
     if (!context.is(tmp.reg())) {
       __ mov(tmp.reg(), context);
     }
     __ bind(&next);
     // Terminate at global context.
     __ cmp(FieldOperand(tmp.reg(), HeapObject::kMapOffset),
            Immediate(Factory::global_context_map()));
@@ skipping 1510 matching lines @@
       // It will be discarded anyway, and can have no side effect.
       frame_->Push(Factory::undefined_value());
     } else {
       Load(node->expression());
       frame_->SetElementAt(0, Factory::undefined_value());
     }
 
   } else {
     Load(node->expression());
     switch (op) {
-      case Token::NOT:
-      case Token::DELETE:
-      case Token::TYPEOF:
-        UNREACHABLE();  // handled above
-        break;
-
       case Token::SUB: {
         bool overwrite =
             (node->AsBinaryOperation() != NULL &&
              node->AsBinaryOperation()->ResultOverwriteAllowed());
         UnarySubStub stub(overwrite);
         // TODO(1222589): remove dependency of TOS being cached inside stub
         Result operand = frame_->Pop();
         Result answer = frame_->CallStub(&stub, &operand);
         frame_->Push(&answer);
         break;
@@ skipping 34 matching lines @@
         frame_->Push(&operand);
         Result answer = frame_->InvokeBuiltin(Builtins::TO_NUMBER,
                                               CALL_FUNCTION, 1);
 
         continue_label.Bind(&answer);
         frame_->Push(&answer);
         break;
       }
 
       default:
+        // NOT, DELETE, TYPEOF, and VOID are handled outside the
+        // switch.
         UNREACHABLE();
     }
   }
 }
 
 
 // The value in dst was optimistically incremented or decremented.  The
 // result overflowed or was not smi tagged.  Undo the operation, call
 // into the runtime to convert the argument to a number, and call the
 // specialized add or subtract stub.  The result is left in dst.
@@ skipping 2460 matching lines @@
 
 int CompareStub::MinorKey() {
   // Encode the two parameters in a unique 16 bit value.
   ASSERT(static_cast<unsigned>(cc_) < (1 << 15));
   return (static_cast<unsigned>(cc_) << 1) | (strict_ ? 1 : 0);
 }
 
 #undef __
 
 } }  // namespace v8::internal