lib/Bindings/Python/Pass.cpp

//===- Pass.cpp - Pass Management -----------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#include "Pass.h"

#include "IRModule.h"
#include "mlir-c/Bindings/Python/Interop.h"
#include "mlir-c/Pass.h"

namespace py = pybind11;
using namespace py::literals;
using namespace mlir;
using namespace mlir::python;

namespace {

/// Owning Wrapper around a PassManager.
class PyPassManager {
public:
  PyPassManager(MlirPassManager passManager) : passManager(passManager) {}
  PyPassManager(PyPassManager &&other) noexcept
      : passManager(other.passManager) {
    other.passManager.ptr = nullptr;
  }
  ~PyPassManager() {
    if (!mlirPassManagerIsNull(passManager))
      mlirPassManagerDestroy(passManager);
  }
  MlirPassManager get() { return passManager; }

  void release() { passManager.ptr = nullptr; }
  pybind11::object getCapsule() {
    return py::reinterpret_steal<py::object>(
        mlirPythonPassManagerToCapsule(get()));
  }

  static pybind11::object createFromCapsule(pybind11::object capsule) {
    MlirPassManager rawPm = mlirPythonCapsuleToPassManager(capsule.ptr());
    if (mlirPassManagerIsNull(rawPm))
      throw py::error_already_set();
    return py::cast(PyPassManager(rawPm), py::return_value_policy::move);
  }

private:
  MlirPassManager passManager;
};

} // namespace

/// Create the `mlir.passmanager` here.
void mlir::python::populatePassManagerSubmodule(py::module &m) {
  //----------------------------------------------------------------------------
  // Mapping of the top-level PassManager
  //----------------------------------------------------------------------------
  py::class_<PyPassManager>(m, "PassManager", py::module_local())
      .def(py::init<>([](const std::string &anchorOp,
                         DefaultingPyMlirContext context) {
             MlirPassManager passManager = mlirPassManagerCreateOnOperation(
                 context->get(),
                 mlirStringRefCreate(anchorOp.data(), anchorOp.size()));
             return new PyPassManager(passManager);
           }),
           "anchor_op"_a = py::str("any"), "context"_a = py::none(),
           "Create a new PassManager for the current (or provided) Context.")
      .def_property_readonly(MLIR_PYTHON_CAPI_PTR_ATTR,
                             &PyPassManager::getCapsule)
      .def(MLIR_PYTHON_CAPI_FACTORY_ATTR, &PyPassManager::createFromCapsule)
      .def("_testing_release", &PyPassManager::release,
           "Releases (leaks) the backing pass manager (testing)")
      .def(
          "enable_ir_printing",
          [](PyPassManager &passManager) {
            mlirPassManagerEnableIRPrinting(passManager.get());
          },
          "Enable mlir-print-ir-after-all.")
      .def(
          "enable_verifier",
          [](PyPassManager &passManager, bool enable) {
            mlirPassManagerEnableVerifier(passManager.get(), enable);
          },
          "enable"_a, "Enable / disable verify-each.")
      .def_static(
          "parse",
          [](const std::string &pipeline, DefaultingPyMlirContext context) {
            MlirPassManager passManager = mlirPassManagerCreate(context->get());
            PyPrintAccumulator errorMsg;
            MlirLogicalResult status = mlirParsePassPipeline(
                mlirPassManagerGetAsOpPassManager(passManager),
                mlirStringRefCreate(pipeline.data(), pipeline.size()),
                errorMsg.getCallback(), errorMsg.getUserData());
            if (mlirLogicalResultIsFailure(status))
              throw py::value_error(std::string(errorMsg.join()));
            return new PyPassManager(passManager);
          },
          "pipeline"_a, "context"_a = py::none(),
          "Parse a textual pass-pipeline and return a top-level PassManager "
          "that can be applied on a Module. Throw a ValueError if the pipeline "
          "can't be parsed")
      .def(
          "add",
          [](PyPassManager &passManager, const std::string &pipeline) {
            PyPrintAccumulator errorMsg;
            MlirLogicalResult status = mlirOpPassManagerAddPipeline(
                mlirPassManagerGetAsOpPassManager(passManager.get()),
                mlirStringRefCreate(pipeline.data(), pipeline.size()),
                errorMsg.getCallback(), errorMsg.getUserData());
            if (mlirLogicalResultIsFailure(status))
              throw py::value_error(std::string(errorMsg.join()));
          },
          "pipeline"_a,
          "Add textual pipeline elements to the pass manager. Throws a "
          "ValueError if the pipeline can't be parsed.")
      .def(
          "run",
          [](PyPassManager &passManager, PyOperationBase &op,
             bool invalidateOps) {
            if (invalidateOps) {
              op.getOperation().getContext()->clearOperationsInside(op);
            }
            // Actually run the pass manager.
            PyMlirContext::ErrorCapture errors(op.getOperation().getContext());
            MlirLogicalResult status = mlirPassManagerRunOnOp(
                passManager.get(), op.getOperation().get());
            if (mlirLogicalResultIsFailure(status))
              throw MLIRError("Failure while executing pass pipeline",
                              errors.take());
          },
          "operation"_a, "invalidate_ops"_a = true,
          "Run the pass manager on the provided operation, raising an "
          "MLIRError on failure.")
      .def(
          "__str__",
          [](PyPassManager &self) {
            MlirPassManager passManager = self.get();
            PyPrintAccumulator printAccum;
            mlirPrintPassPipeline(
                mlirPassManagerGetAsOpPassManager(passManager),
                printAccum.getCallback(), printAccum.getUserData());
            return printAccum.join();
          },
          "Print the textual representation for this PassManager, suitable to "
          "be passed to `parse` for round-tripping.");
}