[Mlir-commits] [mlir] e980458 - [MemRef] Fix-forward use-after-scope in #164955 (#165478)

[llvmlistbot at llvm.org]

Author: Thurston Dang
Date: 2025-10-28T15:21:43-07:00
New Revision: e9804584f75c1ab267431c43a0928a8b0a3814f0

URL: https://github.com/llvm/llvm-project/commit/e9804584f75c1ab267431c43a0928a8b0a3814f0
DIFF: https://github.com/llvm/llvm-project/commit/e9804584f75c1ab267431c43a0928a8b0a3814f0.diff

LOG: [MemRef] Fix-forward use-after-scope in #164955 (#165478)

https://github.com/llvm/llvm-project/pull/164955 has a use-after-scope
(https://lab.llvm.org/buildbot/#/builders/169/builds/16454):

```
==mlir-opt==3940651==ERROR: AddressSanitizer: stack-use-after-scope on address 0x6e1f6ba5c878 at pc 0x6336b214912a bp 0x7ffe607f1670 sp 0x7ffe607f1668
READ of size 4 at 0x6e1f6ba5c878 thread T0
    #0 0x6336b2149129 in size /home/b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/include/llvm/ADT/SmallVector.h:80:32
    #1 0x6336b2149129 in operator[] /home/b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/include/llvm/ADT/SmallVector.h:299:5
    #2 0x6336b2149129 in populateBoundsForShapedValueDim /home/b/sanitizer-x86_64-linux-fast/build/llvm-project/mlir/lib/Dialect/MemRef/IR/ValueBoundsOpInterfaceImpl.cpp:113:43
...
```

This patch attempts to fix-forward by stack-allocating reassocIndices,
instead of taking a reference to a return value.

Added: 
    

Modified: 
    mlir/lib/Dialect/MemRef/IR/ValueBoundsOpInterfaceImpl.cpp

Removed: 
    


################################################################################
diff  --git a/mlir/lib/Dialect/MemRef/IR/ValueBoundsOpInterfaceImpl.cpp b/mlir/lib/Dialect/MemRef/IR/ValueBoundsOpInterfaceImpl.cpp
index 3aa801b48a2e9..69afbcadb0b07 100644
--- a/mlir/lib/Dialect/MemRef/IR/ValueBoundsOpInterfaceImpl.cpp
+++ b/mlir/lib/Dialect/MemRef/IR/ValueBoundsOpInterfaceImpl.cpp
@@ -107,7 +107,7 @@ struct CollapseShapeOpInterface
     assert(value == collapseOp.getResult() && "invalid value");
 
     // Multiply the expressions for the dimensions in the reassociation group.
-    const ReassociationIndices &reassocIndices =
+    const ReassociationIndices reassocIndices =
         collapseOp.getReassociationIndices()[dim];
     AffineExpr productExpr =
         cstr.getExpr(collapseOp.getSrc(), reassocIndices[0]);