[Mlir-commits] [mlir] [MLIR][Python] Add bindings for PDL native rewrite function registering (PR #159926)

[Maksim Levental]

================
@@ -36,6 +41,43 @@ class PyPDLPatternModule {
   }
   MlirPDLPatternModule get() { return module; }
 
+  static nb::object fromPDLValue(MlirPDLValue value) {
+    if (mlirPDLValueIsValue(value)) {
+      return nb::cast(mlirPDLValueAsValue(value));
+    }
+    if (mlirPDLValueIsOperation(value)) {
+      return nb::cast(mlirPDLValueAsOperation(value));
+    }
+    if (mlirPDLValueIsAttribute(value)) {
+      return nb::cast(mlirPDLValueAsAttribute(value));
+    }
+    if (mlirPDLValueIsType(value)) {
+      return nb::cast(mlirPDLValueAsType(value));
+    }
+
+    throw std::runtime_error("unsupported PDL value type");
+  }
+
+  void registerRewriteFunction(const std::string &name,
+                               const nb::callable &fn) {
+    mlirPDLPatternModuleRegisterRewriteFunction(
+        get(), mlirStringRefCreate(name.data(), name.size()),
+        [](MlirPatternRewriter rewriter, MlirPDLResultList results,
+           size_t nValues, MlirPDLValue *values,
+           void *userData) -> MlirLogicalResult {
+          auto f = nb::handle(static_cast<PyObject *>(userData));
+          std::vector<nb::object> args;
+          args.reserve(nValues);
+          for (size_t i = 0; i < nValues; ++i) {
+            args.push_back(fromPDLValue(values[i]));
+          }
----------------
makslevental wrote:

nit:
```suggestion
          for (size_t i = 0; i < nValues; ++i)
            args.push_back(fromPDLValue(values[i]));
```

https://github.com/llvm/llvm-project/pull/159926