[PATCH] D117664: [Support] Remove incorrect noalias return attribute in BumpPtrAllocator

[Nikita Popov via Phabricator via llvm-commits]

nikic created this revision.
nikic added reviewers: aganea, reames, jdoerfert.
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The memory returned by the Allocate() function is also otherwise accessible -- and is indeed accessed by the DestroyAll() method of SpecificBumpPtrAlloactor. This is a violation of the noalias return contract.

This should address the issue reported in https://reviews.llvm.org/D116728#3252464.


https://reviews.llvm.org/D117664

Files:
  llvm/include/llvm/Support/Allocator.h


Index: llvm/include/llvm/Support/Allocator.h
===================================================================
--- llvm/include/llvm/Support/Allocator.h
+++ llvm/include/llvm/Support/Allocator.h
@@ -141,8 +141,7 @@
   }
 
   /// Allocate space at the specified alignment.
-  LLVM_ATTRIBUTE_RETURNS_NONNULL LLVM_ATTRIBUTE_RETURNS_NOALIAS void *
-  Allocate(size_t Size, Align Alignment) {
+  LLVM_ATTRIBUTE_RETURNS_NONNULL void *Allocate(size_t Size, Align Alignment) {
     // Keep track of how many bytes we've allocated.
     BytesAllocated += Size;
 
@@ -198,7 +197,7 @@
     return AlignedPtr;
   }
 
-  inline LLVM_ATTRIBUTE_RETURNS_NONNULL LLVM_ATTRIBUTE_RETURNS_NOALIAS void *
+  inline LLVM_ATTRIBUTE_RETURNS_NONNULL void *
   Allocate(size_t Size, size_t Alignment) {
     assert(Alignment > 0 && "0-byte alignment is not allowed. Use 1 instead.");
     return Allocate(Size, Align(Alignment));


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