[Mlir-commits] [mlir] [MLIR][Python] add mlirLLVMStructTypeGetTypeID and enable downcasting for StructType (PR #169383)

[Maksim Levental]

https://github.com/makslevental created https://github.com/llvm/llvm-project/pull/169383

None

>From ca34a23ad44fc5a5cc2f43533efa8045f70b94c0 Mon Sep 17 00:00:00 2001
From: Maksim Levental <maksim.levental at gmail.com>
Date: Mon, 24 Nov 2025 10:19:20 -0800
Subject: [PATCH] [MLIR][Python] add mlirLLVMStructTypeGetTypeID and enable
 downcasting for StructType

---
 mlir/include/mlir-c/Dialect/LLVM.h       | 2 ++
 mlir/lib/Bindings/Python/DialectLLVM.cpp | 4 ++--
 mlir/lib/CAPI/Dialect/LLVM.cpp           | 4 ++++
 mlir/test/python/dialects/llvm.py        | 3 +++
 4 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/mlir/include/mlir-c/Dialect/LLVM.h b/mlir/include/mlir-c/Dialect/LLVM.h
index c1ade9ed8617c..a0fbfd5c8227a 100644
--- a/mlir/include/mlir-c/Dialect/LLVM.h
+++ b/mlir/include/mlir-c/Dialect/LLVM.h
@@ -58,6 +58,8 @@ MLIR_CAPI_EXPORTED MlirType mlirLLVMFunctionTypeGetReturnType(MlirType type);
 /// Returns `true` if the type is an LLVM dialect struct type.
 MLIR_CAPI_EXPORTED bool mlirTypeIsALLVMStructType(MlirType type);
 
+MLIR_CAPI_EXPORTED MlirTypeID mlirLLVMStructTypeGetTypeID();
+
 /// Returns `true` if the type is a literal (unnamed) LLVM struct type.
 MLIR_CAPI_EXPORTED bool mlirLLVMStructTypeIsLiteral(MlirType type);
 
diff --git a/mlir/lib/Bindings/Python/DialectLLVM.cpp b/mlir/lib/Bindings/Python/DialectLLVM.cpp
index 870a713b8edcb..63aa707a4adde 100644
--- a/mlir/lib/Bindings/Python/DialectLLVM.cpp
+++ b/mlir/lib/Bindings/Python/DialectLLVM.cpp
@@ -31,8 +31,8 @@ static void populateDialectLLVMSubmodule(nanobind::module_ &m) {
   // StructType
   //===--------------------------------------------------------------------===//
 
-  auto llvmStructType =
-      mlir_type_subclass(m, "StructType", mlirTypeIsALLVMStructType);
+  auto llvmStructType = mlir_type_subclass(
+      m, "StructType", mlirTypeIsALLVMStructType, mlirLLVMStructTypeGetTypeID);
 
   llvmStructType
       .def_classmethod(
diff --git a/mlir/lib/CAPI/Dialect/LLVM.cpp b/mlir/lib/CAPI/Dialect/LLVM.cpp
index 6636f0ea73ec9..560148abf4c91 100644
--- a/mlir/lib/CAPI/Dialect/LLVM.cpp
+++ b/mlir/lib/CAPI/Dialect/LLVM.cpp
@@ -73,6 +73,10 @@ bool mlirTypeIsALLVMStructType(MlirType type) {
   return isa<LLVM::LLVMStructType>(unwrap(type));
 }
 
+MlirTypeID mlirLLVMStructTypeGetTypeID() {
+  return wrap(LLVM::LLVMStructType::getTypeID());
+}
+
 bool mlirLLVMStructTypeIsLiteral(MlirType type) {
   return !cast<LLVM::LLVMStructType>(unwrap(type)).isIdentified();
 }
diff --git a/mlir/test/python/dialects/llvm.py b/mlir/test/python/dialects/llvm.py
index 8ea0fddee3f7c..547e541b43bdf 100644
--- a/mlir/test/python/dialects/llvm.py
+++ b/mlir/test/python/dialects/llvm.py
@@ -98,6 +98,9 @@ def testStructType():
     assert opaque.opaque
     # CHECK: !llvm.struct<"opaque", opaque>
 
+    typ = Type.parse('!llvm.struct<"zoo", (i32, i64)>')
+    assert isinstance(type, llvm.StructType)
+
 
 # CHECK-LABEL: testSmoke
 @constructAndPrintInModule