| 1 | //===- OwningOpRef.h - MLIR OwningOpRef -------------------------*- C++ -*-===// |
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| 2 | // |
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| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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| 4 | // See https://llvm.org/LICENSE.txt for license information. |
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| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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| 6 | // |
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| 7 | //===----------------------------------------------------------------------===// |
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| 8 | // |
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| 9 | // This file provides a base class for owning op refs. |
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| 10 | // |
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| 11 | //===----------------------------------------------------------------------===// |
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| 12 | |
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| 13 | #ifndef MLIR_IR_OWNINGOPREF_H |
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| 14 | #define MLIR_IR_OWNINGOPREF_H |
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| 15 | |
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| 16 | #include <type_traits> |
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| 17 | #include <utility> |
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| 18 | |
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| 19 | namespace mlir { |
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| 20 | class Operation; |
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| 21 | |
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| 22 | /// This class acts as an owning reference to an op, and will automatically |
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| 23 | /// destroy the held op on destruction if the held op is valid. |
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| 24 | /// |
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| 25 | /// Note that OpBuilder and related functionality should be highly preferred |
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| 26 | /// instead, and this should only be used in situations where existing solutions |
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| 27 | /// are not viable. |
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| 28 | template <typename OpTy> |
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| 29 | class OwningOpRef { |
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| 30 | public: |
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| 31 | /// The underlying operation type stored in this reference. |
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| 32 | using OperationT = OpTy; |
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| 33 | |
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| 34 | OwningOpRef(std::nullptr_t = nullptr) : op(nullptr) {} |
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| 35 | OwningOpRef(OpTy op) : op(op) {} |
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| 36 | OwningOpRef(OwningOpRef &&other) : op(other.release()) {} |
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| 37 | ~OwningOpRef() { |
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| 38 | if (op) |
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| 39 | op->erase(); |
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| 40 | } |
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| 41 | |
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| 42 | /// Assign from another op reference. |
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| 43 | OwningOpRef &operator=(OwningOpRef &&other) { |
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| 44 | if (op) |
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| 45 | op->erase(); |
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| 46 | op = other.release(); |
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| 47 | return *this; |
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| 48 | } |
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| 49 | |
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| 50 | /// Allow accessing the internal op. |
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| 51 | OpTy get() const { return op; } |
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| 52 | OpTy operator*() const { return op; } |
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| 53 | auto operator->() { |
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| 54 | // Specialize for the case where OpTy is a pointer, to allow using |
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| 55 | // OwningOpRef<Operation*>. |
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| 56 | if constexpr (std::is_pointer<OpTy>::value) |
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| 57 | return op; |
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| 58 | else |
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| 59 | return &op; |
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| 60 | } |
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| 61 | explicit operator bool() const { return op; } |
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| 62 | |
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| 63 | /// Downcast to generic operation. |
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| 64 | operator OwningOpRef<Operation *>() && { return release().getOperation(); } |
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| 65 | |
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| 66 | /// Release the referenced op. |
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| 67 | OpTy release() { |
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| 68 | OpTy released(nullptr); |
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| 69 | std::swap(released, op); |
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| 70 | return released; |
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| 71 | } |
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| 72 | |
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| 73 | private: |
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| 74 | OpTy op; |
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| 75 | }; |
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| 76 | |
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| 77 | } // namespace mlir |
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| 78 | |
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| 79 | #endif // MLIR_IR_OWNINGOPREF_H |
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| 80 | |
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