[Mlir-commits] [mlir] [mlir][emitc] Fix emitc.for verification crash (PR #163754)

[Longsheng Mou]

https://github.com/CoTinker updated https://github.com/llvm/llvm-project/pull/163754

>From 5322f72f5fa6d36b0070fad9ebb36454b8a7a04d Mon Sep 17 00:00:00 2001
From: Longsheng Mou <longshengmou at gmail.com>
Date: Thu, 16 Oct 2025 19:28:36 +0800
Subject: [PATCH 1/3] [mlir][emitc] Fix `emitc.for` verification crash

This PR adds block arguments check to prevent a crash in `emitc.for` verifier.
---
 mlir/lib/Dialect/EmitC/IR/EmitC.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/mlir/lib/Dialect/EmitC/IR/EmitC.cpp b/mlir/lib/Dialect/EmitC/IR/EmitC.cpp
index 0992ce14b4afb..bae1e5202975f 100644
--- a/mlir/lib/Dialect/EmitC/IR/EmitC.cpp
+++ b/mlir/lib/Dialect/EmitC/IR/EmitC.cpp
@@ -584,6 +584,10 @@ void ForOp::print(OpAsmPrinter &p) {
 LogicalResult ForOp::verifyRegions() {
   // Check that the body defines as single block argument for the induction
   // variable.
+  if (getBody()->getNumArguments() == 0)
+    return emitOpError("expected body to have a single block argument for the "
+                       "induction variable");
+
   if (getInductionVar().getType() != getLowerBound().getType())
     return emitOpError(
         "expected induction variable to be same type as bounds and step");

>From 3ccbe53df43ea1c84062b37c5941c2d13a62a68b Mon Sep 17 00:00:00 2001
From: Longsheng Mou <longshengmou at gmail.com>
Date: Thu, 16 Oct 2025 19:30:26 +0800
Subject: [PATCH 2/3] add test

---
 mlir/test/Dialect/EmitC/invalid_ops.mlir | 25 ++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/mlir/test/Dialect/EmitC/invalid_ops.mlir b/mlir/test/Dialect/EmitC/invalid_ops.mlir
index 5f594fb08c43f..f30a614a93de0 100644
--- a/mlir/test/Dialect/EmitC/invalid_ops.mlir
+++ b/mlir/test/Dialect/EmitC/invalid_ops.mlir
@@ -876,3 +876,28 @@ func.func @test_do(%arg0 : !emitc.ptr<i32>) {
 
   return
 }
+
+// -----
+
+func.func @test_for_none_block_argument(%arg0: index) {
+  // expected-error at +1 {{expected body to have a single block argument for the induction variable}}
+  "emitc.for"(%arg0, %arg0, %arg0) (
+    {
+      emitc.yield
+    }
+  ) : (index, index, index) -> ()
+  return
+}
+
+// -----
+
+func.func @test_for_unmatch_type(%arg0: index) {
+  // expected-error at +1 {{expected induction variable to be same type as bounds}}
+  "emitc.for"(%arg0, %arg0, %arg0) (
+    {
+    ^bb0(%i0 : f32):
+      emitc.yield
+    }
+  ) : (index, index, index) -> ()
+  return
+}

>From 4feaf0173f5fdf43066a560e1103df654e20da31 Mon Sep 17 00:00:00 2001
From: Longsheng Mou <longshengmou at gmail.com>
Date: Sat, 1 Nov 2025 12:09:07 +0800
Subject: [PATCH 3/3] fix review

---
 mlir/lib/Dialect/EmitC/IR/EmitC.cpp      |  2 +-
 mlir/test/Dialect/EmitC/invalid_ops.mlir | 13 +++++++++++++
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/mlir/lib/Dialect/EmitC/IR/EmitC.cpp b/mlir/lib/Dialect/EmitC/IR/EmitC.cpp
index bae1e5202975f..d478220221f7a 100644
--- a/mlir/lib/Dialect/EmitC/IR/EmitC.cpp
+++ b/mlir/lib/Dialect/EmitC/IR/EmitC.cpp
@@ -584,7 +584,7 @@ void ForOp::print(OpAsmPrinter &p) {
 LogicalResult ForOp::verifyRegions() {
   // Check that the body defines as single block argument for the induction
   // variable.
-  if (getBody()->getNumArguments() == 0)
+  if (getBody()->getNumArguments() != 1)
     return emitOpError("expected body to have a single block argument for the "
                        "induction variable");
 
diff --git a/mlir/test/Dialect/EmitC/invalid_ops.mlir b/mlir/test/Dialect/EmitC/invalid_ops.mlir
index f30a614a93de0..f285196d466ce 100644
--- a/mlir/test/Dialect/EmitC/invalid_ops.mlir
+++ b/mlir/test/Dialect/EmitC/invalid_ops.mlir
@@ -891,6 +891,19 @@ func.func @test_for_none_block_argument(%arg0: index) {
 
 // -----
 
+func.func @test_for_more_than_one_block_argument(%arg0: index) {
+  // expected-error at +1 {{expected body to have a single block argument for the induction variable}}
+  "emitc.for"(%arg0, %arg0, %arg0) (
+    {
+    ^bb0(%i0 : index, %i1 : index):
+      emitc.yield
+    }
+  ) : (index, index, index) -> ()
+  return
+}
+
+// -----
+
 func.func @test_for_unmatch_type(%arg0: index) {
   // expected-error at +1 {{expected induction variable to be same type as bounds}}
   "emitc.for"(%arg0, %arg0, %arg0) (