[compiler-rt] [scudo] Only init RingBuffer when needed. (PR #85994)

[via llvm-commits]

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@@ -867,29 +867,83 @@ SCUDO_TYPED_TEST(ScudoCombinedTest, ReallocateInPlaceStress) {
   }
 }
 
+SCUDO_TYPED_TEST(ScudoCombinedTest, RingBufferDefaultDisabled) {
+  // The RingBuffer is not initialized until tracking is enabled for the
+  // first time.
+  auto *Allocator = this->Allocator.get();
+  ASSERT_EQ(0u, Allocator->getRingBufferSize());
+  ASSERT_EQ(nullptr, Allocator->getRingBufferAddress());
+}
+
+SCUDO_TYPED_TEST(ScudoCombinedTest, RingBufferInitOnce) {
+  auto *Allocator = this->Allocator.get();
+  Allocator->setTrackAllocationStacks(true);
+
+  auto Size = Allocator->getRingBufferSize();
+  ASSERT_GT(Size, 0u);
+  auto *Addr = Allocator->getRingBufferAddress();
+  EXPECT_NE(nullptr, Addr);
+
+  // Enable tracking again to verify that the initialization only happens once.
+  Allocator->setTrackAllocationStacks(true);
+  ASSERT_EQ(Size, Allocator->getRingBufferSize());
+  EXPECT_EQ(Addr, Allocator->getRingBufferAddress());
+}
+
 SCUDO_TYPED_TEST(ScudoCombinedTest, RingBufferSize) {
   auto *Allocator = this->Allocator.get();
+  Allocator->setTrackAllocationStacks(true);
+
   auto Size = Allocator->getRingBufferSize();
   ASSERT_GT(Size, 0u);
   EXPECT_EQ(Allocator->getRingBufferAddress()[Size - 1], '\0');
 }
 
 SCUDO_TYPED_TEST(ScudoCombinedTest, RingBufferAddress) {
   auto *Allocator = this->Allocator.get();
+  Allocator->setTrackAllocationStacks(true);
+
   auto *Addr = Allocator->getRingBufferAddress();
   EXPECT_NE(Addr, nullptr);
   EXPECT_EQ(Addr, Allocator->getRingBufferAddress());
 }
 
+SCUDO_TYPED_TEST(ScudoCombinedTest, StackDepotDefaultDisabled) {
+  // The StackDepot is not initialized until tracking is enabled for the
+  // first time.
+  auto *Allocator = this->Allocator.get();
+  ASSERT_EQ(0u, Allocator->getStackDepotSize());
+  ASSERT_EQ(nullptr, Allocator->getStackDepotAddress());
+}
+
+SCUDO_TYPED_TEST(ScudoCombinedTest, StackDepotInitOnce) {
+  auto *Allocator = this->Allocator.get();
+  Allocator->setTrackAllocationStacks(true);
+
+  auto Size = Allocator->getStackDepotSize();
+  ASSERT_GT(Size, 0u);
+  auto *Addr = Allocator->getStackDepotAddress();
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ChiaHungDuan wrote:

I may suggest spelling out the type if possible. 

https://github.com/llvm/llvm-project/pull/85994