Fix --max_old_space_size=4096 integer overflow.

src/heap/heap.cc

 // Copyright 2012 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/v8.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/base/bits.h"
 #include "src/base/once.h"
@@ skipping 5090 matching lines @@
 // size is not big enough to fit all the initial objects.
 bool Heap::ConfigureHeap(int max_semi_space_size, int max_old_space_size,
                          int max_executable_size, size_t code_range_size) {
   if (HasBeenSetUp()) return false;
 
   // Overwrite default configuration.
   if (max_semi_space_size > 0) {
     max_semi_space_size_ = max_semi_space_size * MB;
   }
   if (max_old_space_size > 0) {
-    max_old_generation_size_ = max_old_space_size * MB;
+    max_old_generation_size_ = static_cast<intptr_t>(max_old_space_size) * MB;
   }
   if (max_executable_size > 0) {
-    max_executable_size_ = max_executable_size * MB;
+    max_executable_size_ = static_cast<intptr_t>(max_executable_size) * MB;
   }
 
   // If max space size flags are specified overwrite the configuration.
   if (FLAG_max_semi_space_size > 0) {
     max_semi_space_size_ = FLAG_max_semi_space_size * MB;
   }
   if (FLAG_max_old_space_size > 0) {
-    max_old_generation_size_ = FLAG_max_old_space_size * MB;
+    max_old_generation_size_ =
+        static_cast<intptr_t>(FLAG_max_old_space_size) * MB;
   }
   if (FLAG_max_executable_size > 0) {
-    max_executable_size_ = FLAG_max_executable_size * MB;
+    max_executable_size_ = static_cast<intptr_t>(FLAG_max_executable_size) * MB;
   }
 
   if (FLAG_stress_compaction) {
     // This will cause more frequent GCs when stressing.
     max_semi_space_size_ = Page::kPageSize;
   }
 
   if (Snapshot::HaveASnapshotToStartFrom()) {
     // If we are using a snapshot we always reserve the default amount
     // of memory for each semispace because code in the snapshot has
@@ skipping 1327 matching lines @@
       static_cast<int>(object_sizes_last_time_[index]));
   CODE_AGE_LIST_COMPLETE(ADJUST_LAST_TIME_OBJECT_COUNT)
 #undef ADJUST_LAST_TIME_OBJECT_COUNT
 
   MemCopy(object_counts_last_time_, object_counts_, sizeof(object_counts_));
   MemCopy(object_sizes_last_time_, object_sizes_, sizeof(object_sizes_));
   ClearObjectStats();
 }
 }
 }  // namespace v8::internal