[vm] Fix missing null check in FLAG_force_evacuation.

sjindel-google · commit-bot@chromium.org · commit 4ebde3fa9b7f · 2019-08-09T20:51:41.000Z
Bug: #37772 Change-Id: I4e62dd0355fe0ebc7716de05a093142389067191 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/112403 Commit-Queue: Ryan Macnak <rmacnak@google.com> Reviewed-by: Ryan Macnak <rmacnak@google.com>
diff --git a/runtime/vm/heap/compactor.cc b/runtime/vm/heap/compactor.cc
@@ -213,11 +213,19 @@ void GCCompactor::Compact(HeapPage* pages,
     // objects move and all pages that used to have an object are released.
     // This can be helpful for finding untracked pointers because it prevents
     // an untracked pointer from getting lucky with its target not moving.
-    for (intptr_t task_index = 0; task_index < num_tasks; task_index++) {
+    bool oom = false;
+    for (intptr_t task_index = 0; task_index < num_tasks && !oom;
+         task_index++) {
       const intptr_t pages_per_task = num_pages / num_tasks;
       for (intptr_t j = 0; j < pages_per_task; j++) {
         HeapPage* page = heap_->old_space()->AllocatePage(HeapPage::kData,
                                                           /* link */ false);
+
+        if (page == nullptr) {
+          oom = true;
+          break;
+        }
+
         FreeListElement::AsElement(page->object_start(),
                                    page->object_end() - page->object_start());
 
