[mlir] fix crash in transform.print verification

[ftynse]

Transform op trait verification calls getEffects, and since trait verification runs before op verification, this call cannot assume the op to be valid. However, the operand getters now return a TypedValue that unconditionally casts the value to the expected type, leading to an assertion failure. Use the untyped mechanism instead.

Fixes #84701.

[llvmbot]

@llvm/pr-subscribers-mlir

Author: Oleksandr "Alex" Zinenko (ftynse)

Changes

Transform op trait verification calls getEffects, and since trait verification runs before op verification, this call cannot assume the op to be valid. However, the operand getters now return a TypedValue that unconditionally casts the value to the expected type, leading to an assertion failure. Use the untyped mechanism instead.

Fixes #84701.

---

Full diff: https://github.com/llvm/llvm-project/pull/86679.diff

2 Files Affected:

• (modified) mlir/lib/Dialect/Transform/IR/TransformOps.cpp (+5-1)
• (modified) mlir/test/Dialect/Transform/ops-invalid.mlir (+11)

diff --git a/mlir/lib/Dialect/Transform/IR/TransformOps.cpp b/mlir/lib/Dialect/Transform/IR/TransformOps.cpp
index 8d2ed8f6d73714..abd557a508a103 100644
--- a/mlir/lib/Dialect/Transform/IR/TransformOps.cpp
+++ b/mlir/lib/Dialect/Transform/IR/TransformOps.cpp
@@ -2628,7 +2628,11 @@ transform::PrintOp::apply(transform::TransformRewriter &rewriter,
 
 void transform::PrintOp::getEffects(
     SmallVectorImpl<MemoryEffects::EffectInstance> &effects) {
-  onlyReadsHandle(getTarget(), effects);
+  // We don't really care about mutability here, but `getTarget` now
+  // unconditionally casts to a specific type before verification could run
+  // here.
+  if (!getTargetMutable().empty())
+    onlyReadsHandle(getTargetMutable()[0].get(), effects);
   onlyReadsPayload(effects);
 
   // There is no resource for stderr file descriptor, so just declare print
diff --git a/mlir/test/Dialect/Transform/ops-invalid.mlir b/mlir/test/Dialect/Transform/ops-invalid.mlir
index 73a5f36af92952..cc04e65420c5b7 100644
--- a/mlir/test/Dialect/Transform/ops-invalid.mlir
+++ b/mlir/test/Dialect/Transform/ops-invalid.mlir
@@ -771,3 +771,14 @@ module attributes { transform.with_named_sequence } {
     transform.yield %arg0 : !transform.any_op
   }
 }
+
+// -----
+
+module attributes { transform.with_named_sequence } {
+  transform.named_sequence @match_matmul(%entry: !transform.any_op) -> () {
+    %c3 = transform.param.constant 1 : i64 -> !transform.param<i64>
+    // expected-error @below {{op operand #0 must be TransformHandleTypeInterface instance}}
+    transform.print %c3 : !transform.param<i64>
+    transform.yield
+  }
+}

[kuhar]

Thanks, @ftynse! Would it be feasible to actually support printing types and params?

[ftynse]

We have this: https://mlir.llvm.org/docs/Dialects/Transform/#transformdebugemit_param_as_remark-transformdebugemitparamasremarkop.

Types are justs a param that holds a TypeAttr AFAIU so it should work, let me know if it does not.