[Mlir-commits] [mlir] [mlir][IR] Initialize empty AsmResourceBlob mutability (PR #220586)

[Mehdi Amini]

https://github.com/joker-eph created https://github.com/llvm/llvm-project/pull/220586

The default constructor leaves dataIsMutable indeterminate even though isMutable may be called on an empty blob. Treat default-constructed blobs as immutable and cover that state with a unit test.

Valgrind pre-fix trace:

```
  Invalid read of size 8
    at testing::Test::Run()
  Invalid write of size 8
  Invalid free() / delete / delete[] / realloc()
  ERROR SUMMARY: 6 errors from 6 contexts
```

Found by Coverity.

Assisted-by: Codex

>From 8a6dafe7494402b8ea2c6e577bc42c0bbd3da3d6 Mon Sep 17 00:00:00 2001
From: Mehdi Amini <joker.eph at gmail.com>
Date: Wed, 2 Sep 2026 05:56:04 -0700
Subject: [PATCH] [mlir][IR] Initialize empty AsmResourceBlob mutability

The default constructor leaves dataIsMutable indeterminate even though
isMutable may be called on an empty blob. Treat default-constructed blobs as
immutable and cover that state with a unit test.

Valgrind pre-fix trace:

  Invalid read of size 8
    at testing::Test::Run()
  Invalid write of size 8
  Invalid free() / delete / delete[] / realloc()
  ERROR SUMMARY: 6 errors from 6 contexts

Found by Coverity.

Assisted-by: Codex
---
 mlir/include/mlir/IR/AsmState.h     |  2 +-
 mlir/unittests/IR/AttributeTest.cpp | 11 +++++++++++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/mlir/include/mlir/IR/AsmState.h b/mlir/include/mlir/IR/AsmState.h
index 5e9311742bd94..2c611f6060394 100644
--- a/mlir/include/mlir/IR/AsmState.h
+++ b/mlir/include/mlir/IR/AsmState.h
@@ -179,7 +179,7 @@ class AsmResourceBlob {
   DeleterFn deleter;
 
   /// Whether the data is mutable.
-  bool dataIsMutable;
+  bool dataIsMutable = false;
 
   friend class HeapAsmResourceBlob;
 };
diff --git a/mlir/unittests/IR/AttributeTest.cpp b/mlir/unittests/IR/AttributeTest.cpp
index 17d8e567fbebc..5db6a0c636aa3 100644
--- a/mlir/unittests/IR/AttributeTest.cpp
+++ b/mlir/unittests/IR/AttributeTest.cpp
@@ -262,6 +262,17 @@ TEST(DenseSplatMapValuesTest, I32ToFalse) {
 }
 } // namespace
 
+//===----------------------------------------------------------------------===//
+// AsmResourceBlob
+//===----------------------------------------------------------------------===//
+
+namespace {
+TEST(AsmResourceBlobTest, DefaultBlobIsImmutable) {
+  AsmResourceBlob blob;
+  EXPECT_FALSE(blob.isMutable());
+}
+} // namespace
+
 //===----------------------------------------------------------------------===//
 // DenseResourceElementsAttr
 //===----------------------------------------------------------------------===//