Filter invalid slots after array trimming.

test/unittests/heap/slot-set-unittest.cc

 // Copyright 2016 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 <limits>
 
 #include "src/globals.h"
 #include "src/heap/slot-set.h"
 #include "src/heap/spaces.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ skipping 76 matching lines @@
 
   for (int i = 0; i < Page::kPageSize; i += kPointerSize) {
     if (i % 21 == 0) {
       EXPECT_TRUE(set.Lookup(i));
     } else {
       EXPECT_FALSE(set.Lookup(i));
     }
   }
 }
 
+void CheckRemoveRangeOn(uint32_t start, uint32_t end) {
+  SlotSet set;
+  set.SetPageStart(0);
+  uint32_t first = start == 0 ? 0 : start - kPointerSize;
+  for (uint32_t i = first; i <= end; i += kPointerSize) {
+    set.Insert(i);
+  }
+  set.RemoveRange(start, end);
+  if (first != start) {
+    EXPECT_TRUE(set.Lookup(first));
+  }
+  EXPECT_TRUE(set.Lookup(end));
+  for (uint32_t i = start; i < end; i += kPointerSize) {
+    EXPECT_FALSE(set.Lookup(i));
+  }
+}
+
 TEST(SlotSet, RemoveRange) {
-  SlotSet set;
-  set.SetPageStart(0);
-  for (int i = 0; i < Page::kPageSize; i += kPointerSize) {
-    set.Insert(i);
-  }
-
-  set.RemoveRange(0, Page::kPageSize);
-
-  for (int i = 0; i < Page::kPageSize; i += kPointerSize) {
-    EXPECT_FALSE(set.Lookup(i));
-  }
-
-  for (int i = 0; i < Page::kPageSize; i += kPointerSize) {
-    set.Insert(i);
-  }
-
-  set.RemoveRange(10 * kPointerSize, 10 * kPointerSize);
-  EXPECT_TRUE(set.Lookup(9 * kPointerSize));
-  EXPECT_TRUE(set.Lookup(10 * kPointerSize));
-  EXPECT_TRUE(set.Lookup(11 * kPointerSize));
-
-  set.RemoveRange(10 * kPointerSize, 1000 * kPointerSize);
-  for (int i = 0; i < Page::kPageSize; i += kPointerSize) {
-    if (10 * kPointerSize <= i && i < 1000 * kPointerSize) {
-      EXPECT_FALSE(set.Lookup(i));
-    } else {
-      EXPECT_TRUE(set.Lookup(i));
+  CheckRemoveRangeOn(0, Page::kPageSize);
+  CheckRemoveRangeOn(1 * kPointerSize, 1023 * kPointerSize);
+  for (uint32_t start = 0; start <= 32; start++) {
+    CheckRemoveRangeOn(start * kPointerSize, (start + 1) * kPointerSize);
+    CheckRemoveRangeOn(start * kPointerSize, (start + 2) * kPointerSize);
+    const uint32_t kEnds[] = {32, 64, 100, 128, 1024, 1500, 2048};
+    for (int i = 0; i < sizeof(kEnds) / sizeof(uint32_t); i++) {
+      for (int k = -3; k <= 3; k++) {
+        uint32_t end = (kEnds[i] + k);
+        if (start < end) {
+          CheckRemoveRangeOn(start * kPointerSize, end * kPointerSize);
+        }
+      }
     }
   }
 }
 
 }  // namespace internal
 }  // namespace v8