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| Rev | Author | Line No. | Line |
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| 14 | pmbaty | 1 | //===- YAML.h ---------------------------------------------------*- C++ -*-===// |
| 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 | |||
| 9 | #ifndef LLVM_OBJECTYAML_YAML_H |
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| 10 | #define LLVM_OBJECTYAML_YAML_H |
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| 11 | |||
| 12 | #include "llvm/ADT/ArrayRef.h" |
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| 13 | #include "llvm/ADT/StringRef.h" |
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| 14 | #include "llvm/Support/YAMLTraits.h" |
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| 15 | #include <cstdint> |
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| 16 | |||
| 17 | namespace llvm { |
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| 18 | |||
| 19 | class raw_ostream; |
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| 20 | |||
| 21 | namespace yaml { |
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| 22 | |||
| 23 | /// Specialized YAMLIO scalar type for representing a binary blob. |
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| 24 | /// |
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| 25 | /// A typical use case would be to represent the content of a section in a |
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| 26 | /// binary file. |
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| 27 | /// This class has custom YAMLIO traits for convenient reading and writing. |
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| 28 | /// It renders as a string of hex digits in a YAML file. |
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| 29 | /// For example, it might render as `DEADBEEFCAFEBABE` (YAML does not |
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| 30 | /// require the quotation marks, so for simplicity when outputting they are |
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| 31 | /// omitted). |
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| 32 | /// When reading, any string whose content is an even number of hex digits |
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| 33 | /// will be accepted. |
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| 34 | /// For example, all of the following are acceptable: |
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| 35 | /// `DEADBEEF`, `"DeADbEeF"`, `"\x44EADBEEF"` (Note: '\x44' == 'D') |
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| 36 | /// |
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| 37 | /// A significant advantage of using this class is that it never allocates |
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| 38 | /// temporary strings or buffers for any of its functionality. |
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| 39 | /// |
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| 40 | /// Example: |
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| 41 | /// |
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| 42 | /// The YAML mapping: |
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| 43 | /// \code |
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| 44 | /// Foo: DEADBEEFCAFEBABE |
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| 45 | /// \endcode |
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| 46 | /// |
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| 47 | /// Could be modeled in YAMLIO by the struct: |
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| 48 | /// \code |
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| 49 | /// struct FooHolder { |
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| 50 | /// BinaryRef Foo; |
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| 51 | /// }; |
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| 52 | /// namespace llvm { |
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| 53 | /// namespace yaml { |
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| 54 | /// template <> |
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| 55 | /// struct MappingTraits<FooHolder> { |
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| 56 | /// static void mapping(IO &IO, FooHolder &FH) { |
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| 57 | /// IO.mapRequired("Foo", FH.Foo); |
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| 58 | /// } |
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| 59 | /// }; |
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| 60 | /// } // end namespace yaml |
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| 61 | /// } // end namespace llvm |
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| 62 | /// \endcode |
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| 63 | class BinaryRef { |
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| 64 | friend bool operator==(const BinaryRef &LHS, const BinaryRef &RHS); |
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| 65 | |||
| 66 | /// Either raw binary data, or a string of hex bytes (must always |
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| 67 | /// be an even number of characters). |
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| 68 | ArrayRef<uint8_t> Data; |
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| 69 | |||
| 70 | /// Discriminator between the two states of the `Data` member. |
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| 71 | bool DataIsHexString = true; |
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| 72 | |||
| 73 | public: |
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| 74 | BinaryRef() = default; |
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| 75 | BinaryRef(ArrayRef<uint8_t> Data) : Data(Data), DataIsHexString(false) {} |
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| 76 | BinaryRef(StringRef Data) : Data(arrayRefFromStringRef(Data)) {} |
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| 77 | |||
| 78 | /// The number of bytes that are represented by this BinaryRef. |
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| 79 | /// This is the number of bytes that writeAsBinary() will write. |
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| 80 | ArrayRef<uint8_t>::size_type binary_size() const { |
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| 81 | if (DataIsHexString) |
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| 82 | return Data.size() / 2; |
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| 83 | return Data.size(); |
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| 84 | } |
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| 85 | |||
| 86 | /// Write the contents (regardless of whether it is binary or a |
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| 87 | /// hex string) as binary to the given raw_ostream. |
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| 88 | /// N can be used to specify the maximum number of bytes. |
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| 89 | void writeAsBinary(raw_ostream &OS, uint64_t N = UINT64_MAX) const; |
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| 90 | |||
| 91 | /// Write the contents (regardless of whether it is binary or a |
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| 92 | /// hex string) as hex to the given raw_ostream. |
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| 93 | /// |
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| 94 | /// For example, a possible output could be `DEADBEEFCAFEBABE`. |
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| 95 | void writeAsHex(raw_ostream &OS) const; |
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| 96 | }; |
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| 97 | |||
| 98 | inline bool operator==(const BinaryRef &LHS, const BinaryRef &RHS) { |
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| 99 | // Special case for default constructed BinaryRef. |
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| 100 | if (LHS.Data.empty() && RHS.Data.empty()) |
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| 101 | return true; |
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| 102 | |||
| 103 | return LHS.DataIsHexString == RHS.DataIsHexString && LHS.Data == RHS.Data; |
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| 104 | } |
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| 105 | |||
| 106 | template <> struct ScalarTraits<BinaryRef> { |
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| 107 | static void output(const BinaryRef &, void *, raw_ostream &); |
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| 108 | static StringRef input(StringRef, void *, BinaryRef &); |
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| 109 | static QuotingType mustQuote(StringRef S) { return needsQuotes(S); } |
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| 110 | }; |
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| 111 | |||
| 112 | } // end namespace yaml |
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| 113 | |||
| 114 | } // end namespace llvm |
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| 115 | |||
| 116 | #endif // LLVM_OBJECTYAML_YAML_H |