1 files changed, 7 insertions, 19 deletions
diff --git a/include/llvm/Support/Allocator.h b/include/llvm/Support/Allocator.h
index de317719714d..f9b5cf22f97d 100644
--- a/include/llvm/Support/Allocator.h
+++ b/include/llvm/Support/Allocator.h
@@ -148,7 +148,7 @@ public:
       : CurPtr(nullptr), End(nullptr), BytesAllocated(0),
         Allocator(std::forward<T &&>(Allocator)) {}
 
-  // Manually implement a move constructor as we must clear the old allocators
+  // Manually implement a move constructor as we must clear the old allocator's
   // slabs as a matter of correctness.
   BumpPtrAllocatorImpl(BumpPtrAllocatorImpl &&Old)
       : CurPtr(Old.CurPtr), End(Old.End), Slabs(std::move(Old.Slabs)),
@@ -187,6 +187,9 @@ public:
   /// \brief Deallocate all but the current slab and reset the current pointer
   /// to the beginning of it, freeing all memory allocated so far.
   void Reset() {
+    DeallocateCustomSizedSlabs();
+    CustomSizedSlabs.clear();
+
     if (Slabs.empty())
       return;
 
@@ -195,15 +198,14 @@ public:
     CurPtr = (char *)Slabs.front();
     End = CurPtr + SlabSize;
 
-    // Deallocate all but the first slab, and all custome sized slabs.
+    // Deallocate all but the first slab, and deallocate all custom-sized slabs.
     DeallocateSlabs(std::next(Slabs.begin()), Slabs.end());
     Slabs.erase(std::next(Slabs.begin()), Slabs.end());
-    DeallocateCustomSizedSlabs();
-    CustomSizedSlabs.clear();
   }
 
   /// \brief Allocate space at the specified alignment.
-  LLVM_ATTRIBUTE_RETURNS_NONNULL void *Allocate(size_t Size, size_t Alignment) {
+  LLVM_ATTRIBUTE_RETURNS_NONNULL LLVM_ATTRIBUTE_RETURNS_NOALIAS void *
+  Allocate(size_t Size, size_t Alignment) {
     assert(Alignment > 0 && "0-byte alignnment is not allowed. Use 1 instead.");
 
     // Keep track of how many bytes we've allocated.
@@ -319,14 +321,6 @@ private:
     for (; I != E; ++I) {
       size_t AllocatedSlabSize =
           computeSlabSize(std::distance(Slabs.begin(), I));
-#ifndef NDEBUG
-      // Poison the memory so stale pointers crash sooner.  Note we must
-      // preserve the Size and NextPtr fields at the beginning.
-      if (AllocatedSlabSize != 0) {
-        sys::Memory::setRangeWritable(*I, AllocatedSlabSize);
-        memset(*I, 0xCD, AllocatedSlabSize);
-      }
-#endif
       Allocator.Deallocate(*I, AllocatedSlabSize);
     }
   }
@@ -336,12 +330,6 @@ private:
     for (auto &PtrAndSize : CustomSizedSlabs) {
       void *Ptr = PtrAndSize.first;
       size_t Size = PtrAndSize.second;
-#ifndef NDEBUG
-      // Poison the memory so stale pointers crash sooner.  Note we must
-      // preserve the Size and NextPtr fields at the beginning.
-      sys::Memory::setRangeWritable(Ptr, Size);
-      memset(Ptr, 0xCD, Size);
-#endif
       Allocator.Deallocate(Ptr, Size);
     }
   }