[flang-commits] [flang] [flang] Add HLFIR-to-FIR pass pipeline extension points (PR #212194)

[Tarun Prabhu via flang-commits]

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@@ -0,0 +1,223 @@
+//===- PassPipelineTest.cpp -----------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// Tests for the HLFIR extension points of the HLFIR-to-FIR pass pipeline.
+//
+// The callbacks run when the pipeline is built, so no IR is needed: building
+// the pipeline is enough to observe them.
+//
+//===----------------------------------------------------------------------===//
+
+#include "gtest/gtest.h"
+#include "mlir/IR/BuiltinOps.h"
+#include "mlir/IR/MLIRContext.h"
+#include "mlir/Pass/Pass.h"
+#include "mlir/Pass/PassManager.h"
+#include "mlir/Transforms/Passes.h"
+#include "flang/Optimizer/Passes/Pipelines.h"
+#include "flang/Tools/CrossToolHelpers.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Support/raw_ostream.h"
+#include <string>
+#include <vector>
+
+namespace {
+
+/// A no-op pass, identifiable by name in a textual pipeline, used to locate an
+/// extension point.
+struct MarkerPass : public mlir::PassWrapper<MarkerPass,
+                        mlir::OperationPass<mlir::ModuleOp>> {
+  MLIR_DEFINE_EXPLICIT_INTERNAL_INLINE_TYPE_ID(MarkerPass)
+
+  llvm::StringRef getArgument() const override { return "ep-marker"; }
+  llvm::StringRef getDescription() const override {
+    return "No-op pass used to locate an extension point in a pipeline";
+  }
+  void runOnOperation() override {}
+};
+
+/// Render \p pm as a textual pipeline.
+std::string pipelineAsString(mlir::PassManager &pm) {
+  std::string out;
+  llvm::raw_string_ostream os(out);
+  pm.printAsTextualPipeline(os);
+  return out;
+}
+
+/// Build a HLFIR-to-FIR pipeline at \p level with a MarkerPass injected at each
+/// requested extension point, and return it as a textual pipeline.
+std::string pipelineWithMarkers(
+    llvm::OptimizationLevel level, bool early, bool last) {
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tarunprabhu wrote:

Do we really need these additional `early` and `last` booleans? There is a broader question of a whole load of unnecessary tests here (see later comments). If we were to remove those, these would no longer be necessary.

https://github.com/llvm/llvm-project/pull/212194