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| 1 | +//==--- AbstractBasiceReader.h - Abstract basic value deserialization -----===// |
| 2 | +// |
| 3 | +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| 4 | +// See https://llvm.org/LICENSE.txt for license information. |
| 5 | +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| 6 | +// |
| 7 | +//===----------------------------------------------------------------------===// |
| 8 | + |
| 9 | +#ifndef CLANG_AST_ABSTRACTBASICREADER_H |
| 10 | +#define CLANG_AST_ABSTRACTBASICREADER_H |
| 11 | + |
| 12 | +#include "clang/AST/DeclTemplate.h" |
| 13 | + |
| 14 | +namespace clang { |
| 15 | +namespace serialization { |
| 16 | + |
| 17 | +template <class T> |
| 18 | +inline T makeNullableFromOptional(const Optional<T> &value) { |
| 19 | + return (value ? *value : T()); |
| 20 | +} |
| 21 | + |
| 22 | +template <class T> |
| 23 | +inline T *makePointerFromOptional(Optional<T *> value) { |
| 24 | + return (value ? *value : nullptr); |
| 25 | +} |
| 26 | + |
| 27 | +// PropertyReader is a class concept that requires the following method: |
| 28 | +// BasicReader find(llvm::StringRef propertyName); |
| 29 | +// where BasicReader is some class conforming to the BasicReader concept. |
| 30 | +// An abstract AST-node reader is created with a PropertyReader and |
| 31 | +// performs a sequence of calls like so: |
| 32 | +// propertyReader.find(propertyName).read##TypeName() |
| 33 | +// to read the properties of the node it is deserializing. |
| 34 | + |
| 35 | +// BasicReader is a class concept that requires methods like: |
| 36 | +// ValueType read##TypeName(); |
| 37 | +// where TypeName is the name of a PropertyType node from PropertiesBase.td |
| 38 | +// and ValueType is the corresponding C++ type name. The read method may |
| 39 | +// require one or more buffer arguments. |
| 40 | +// |
| 41 | +// In addition to the concrete type names, BasicReader is expected to |
| 42 | +// implement these methods: |
| 43 | +// |
| 44 | +// template <class EnumType> |
| 45 | +// void writeEnum(T value); |
| 46 | +// |
| 47 | +// Reads an enum value from the current property. EnumType will always |
| 48 | +// be an enum type. Only necessary if the BasicReader doesn't provide |
| 49 | +// type-specific readers for all the enum types. |
| 50 | +// |
| 51 | +// template <class ValueType> |
| 52 | +// Optional<ValueType> writeOptional(); |
| 53 | +// |
| 54 | +// Reads an optional value from the current property. |
| 55 | +// |
| 56 | +// template <class ValueType> |
| 57 | +// ArrayRef<ValueType> readArray(llvm::SmallVectorImpl<ValueType> &buffer); |
| 58 | +// |
| 59 | +// Reads an array of values from the current property. |
| 60 | +// |
| 61 | +// PropertyReader readObject(); |
| 62 | +// |
| 63 | +// Reads an object from the current property; the returned property |
| 64 | +// reader will be subjected to a sequence of property reads and then |
| 65 | +// discarded before any other properties are reader from the "outer" |
| 66 | +// property reader (which need not be the same type). The sub-reader |
| 67 | +// will be used as if with the following code: |
| 68 | +// |
| 69 | +// { |
| 70 | +// auto &&widget = W.find("widget").readObject(); |
| 71 | +// auto kind = widget.find("kind").readWidgetKind(); |
| 72 | +// auto declaration = widget.find("declaration").readDeclRef(); |
| 73 | +// return Widget(kind, declaration); |
| 74 | +// } |
| 75 | + |
| 76 | +// ReadDispatcher does type-based forwarding to one of the read methods |
| 77 | +// on the BasicReader passed in: |
| 78 | +// |
| 79 | +// template <class ValueType> |
| 80 | +// struct ReadDispatcher { |
| 81 | +// template <class BasicReader, class... BufferTypes> |
| 82 | +// static ValueType read(BasicReader &R, BufferTypes &&...); |
| 83 | +// }; |
| 84 | + |
| 85 | +// BasicReaderBase provides convenience implementations of the read methods |
| 86 | +// for EnumPropertyType and SubclassPropertyType types that just defer to |
| 87 | +// the "underlying" implementations (for UInt32 and the base class, |
| 88 | +// respectively). |
| 89 | +// |
| 90 | +// template <class Impl> |
| 91 | +// class BasicReaderBase { |
| 92 | +// protected: |
| 93 | +// BasicReaderBase(ASTContext &ctx); |
| 94 | +// Impl &asImpl(); |
| 95 | +// public: |
| 96 | +// ASTContext &getASTContext(); |
| 97 | +// ... |
| 98 | +// }; |
| 99 | + |
| 100 | +// The actual classes are auto-generated; see ClangASTPropertiesEmitter.cpp. |
| 101 | +#include "clang/AST/AbstractBasicReader.inc" |
| 102 | + |
| 103 | +/// DataStreamBasicReader provides convenience implementations for many |
| 104 | +/// BasicReader methods based on the assumption that the |
| 105 | +/// ultimate reader implementation is based on a variable-length stream |
| 106 | +/// of unstructured data (like Clang's module files). It is designed |
| 107 | +/// to pair with DataStreamBasicWriter. |
| 108 | +/// |
| 109 | +/// This class can also act as a PropertyReader, implementing find("...") |
| 110 | +/// by simply forwarding to itself. |
| 111 | +/// |
| 112 | +/// Unimplemented methods: |
| 113 | +/// readBool |
| 114 | +/// readUInt32 |
| 115 | +/// readUInt64 |
| 116 | +/// readIdentifier |
| 117 | +/// readSelector |
| 118 | +/// readSourceLocation |
| 119 | +/// readQualType |
| 120 | +/// readStmtRef |
| 121 | +/// readDeclRef |
| 122 | +template <class Impl> |
| 123 | +class DataStreamBasicReader : public BasicReaderBase<Impl> { |
| 124 | +protected: |
| 125 | + using BasicReaderBase<Impl>::asImpl; |
| 126 | + DataStreamBasicReader(ASTContext &ctx) : BasicReaderBase<Impl>(ctx) {} |
| 127 | + |
| 128 | +public: |
| 129 | + using BasicReaderBase<Impl>::getASTContext; |
| 130 | + |
| 131 | + /// Implement property-find by ignoring it. We rely on properties being |
| 132 | + /// serialized and deserialized in a reliable order instead. |
| 133 | + Impl &find(const char *propertyName) { |
| 134 | + return asImpl(); |
| 135 | + } |
| 136 | + |
| 137 | + template <class T> |
| 138 | + T readEnum() { |
| 139 | + return T(asImpl().readUInt32()); |
| 140 | + } |
| 141 | + |
| 142 | + // Implement object reading by forwarding to this, collapsing the |
| 143 | + // structure into a single data stream. |
| 144 | + Impl &readObject() { return asImpl(); } |
| 145 | + |
| 146 | + template <class T> |
| 147 | + llvm::ArrayRef<T> readArray(llvm::SmallVectorImpl<T> &buffer) { |
| 148 | + assert(buffer.empty()); |
| 149 | + |
| 150 | + uint32_t size = asImpl().readUInt32(); |
| 151 | + buffer.reserve(size); |
| 152 | + |
| 153 | + for (uint32_t i = 0; i != size; ++i) { |
| 154 | + buffer.push_back(ReadDispatcher<T>::read(asImpl())); |
| 155 | + } |
| 156 | + return buffer; |
| 157 | + } |
| 158 | + |
| 159 | + template <class T, class... Args> |
| 160 | + llvm::Optional<T> readOptional(Args &&...args) { |
| 161 | + return UnpackOptionalValue<T>::unpack( |
| 162 | + ReadDispatcher<T>::read(asImpl(), std::forward<Args>(args)...)); |
| 163 | + } |
| 164 | + |
| 165 | + llvm::APSInt readAPSInt() { |
| 166 | + bool isUnsigned = asImpl().readBool(); |
| 167 | + llvm::APInt value = asImpl().readAPInt(); |
| 168 | + return llvm::APSInt(std::move(value), isUnsigned); |
| 169 | + } |
| 170 | + |
| 171 | + llvm::APInt readAPInt() { |
| 172 | + unsigned bitWidth = asImpl().readUInt32(); |
| 173 | + unsigned numWords = llvm::APInt::getNumWords(bitWidth); |
| 174 | + llvm::SmallVector<uint64_t, 4> data; |
| 175 | + for (uint32_t i = 0; i != numWords; ++i) |
| 176 | + data.push_back(asImpl().readUInt64()); |
| 177 | + return llvm::APInt(bitWidth, numWords, &data[0]); |
| 178 | + } |
| 179 | + |
| 180 | + Qualifiers readQualifiers() { |
| 181 | + static_assert(sizeof(Qualifiers().getAsOpaqueValue()) <= sizeof(uint64_t), |
| 182 | + "update this if the value size changes"); |
| 183 | + uint64_t value = asImpl().readUInt64(); |
| 184 | + return Qualifiers::fromOpaqueValue(value); |
| 185 | + } |
| 186 | + |
| 187 | + FunctionProtoType::ExceptionSpecInfo |
| 188 | + readExceptionSpecInfo(llvm::SmallVectorImpl<QualType> &buffer) { |
| 189 | + FunctionProtoType::ExceptionSpecInfo esi; |
| 190 | + esi.Type = ExceptionSpecificationType(asImpl().readUInt32()); |
| 191 | + if (esi.Type == EST_Dynamic) { |
| 192 | + esi.Exceptions = asImpl().template readArray<QualType>(buffer); |
| 193 | + } else if (isComputedNoexcept(esi.Type)) { |
| 194 | + esi.NoexceptExpr = asImpl().readExprRef(); |
| 195 | + } else if (esi.Type == EST_Uninstantiated) { |
| 196 | + esi.SourceDecl = asImpl().readFunctionDeclRef(); |
| 197 | + esi.SourceTemplate = asImpl().readFunctionDeclRef(); |
| 198 | + } else if (esi.Type == EST_Unevaluated) { |
| 199 | + esi.SourceDecl = asImpl().readFunctionDeclRef(); |
| 200 | + } |
| 201 | + return esi; |
| 202 | + } |
| 203 | + |
| 204 | + FunctionProtoType::ExtParameterInfo readExtParameterInfo() { |
| 205 | + static_assert(sizeof(FunctionProtoType::ExtParameterInfo().getOpaqueValue()) |
| 206 | + <= sizeof(uint32_t), |
| 207 | + "opaque value doesn't fit into uint32_t"); |
| 208 | + uint32_t value = asImpl().readUInt32(); |
| 209 | + return FunctionProtoType::ExtParameterInfo::getFromOpaqueValue(value); |
| 210 | + } |
| 211 | + |
| 212 | + NestedNameSpecifier *readNestedNameSpecifier() { |
| 213 | + auto &ctx = getASTContext(); |
| 214 | + |
| 215 | + // We build this up iteratively. |
| 216 | + NestedNameSpecifier *cur = nullptr; |
| 217 | + |
| 218 | + uint32_t depth = asImpl().readUInt32(); |
| 219 | + for (uint32_t i = 0; i != depth; ++i) { |
| 220 | + auto kind = asImpl().readNestedNameSpecifierKind(); |
| 221 | + switch (kind) { |
| 222 | + case NestedNameSpecifier::Identifier: |
| 223 | + cur = NestedNameSpecifier::Create(ctx, cur, |
| 224 | + asImpl().readIdentifier()); |
| 225 | + continue; |
| 226 | + |
| 227 | + case NestedNameSpecifier::Namespace: |
| 228 | + cur = NestedNameSpecifier::Create(ctx, cur, |
| 229 | + asImpl().readNamespaceDeclRef()); |
| 230 | + continue; |
| 231 | + |
| 232 | + case NestedNameSpecifier::NamespaceAlias: |
| 233 | + cur = NestedNameSpecifier::Create(ctx, cur, |
| 234 | + asImpl().readNamespaceAliasDeclRef()); |
| 235 | + continue; |
| 236 | + |
| 237 | + case NestedNameSpecifier::TypeSpec: |
| 238 | + case NestedNameSpecifier::TypeSpecWithTemplate: |
| 239 | + cur = NestedNameSpecifier::Create(ctx, cur, |
| 240 | + kind == NestedNameSpecifier::TypeSpecWithTemplate, |
| 241 | + asImpl().readQualType().getTypePtr()); |
| 242 | + continue; |
| 243 | + |
| 244 | + case NestedNameSpecifier::Global: |
| 245 | + cur = NestedNameSpecifier::GlobalSpecifier(ctx); |
| 246 | + continue; |
| 247 | + |
| 248 | + case NestedNameSpecifier::Super: |
| 249 | + cur = NestedNameSpecifier::SuperSpecifier(ctx, |
| 250 | + asImpl().readCXXRecordDeclRef()); |
| 251 | + continue; |
| 252 | + } |
| 253 | + llvm_unreachable("bad nested name specifier kind"); |
| 254 | + } |
| 255 | + |
| 256 | + return cur; |
| 257 | + } |
| 258 | +}; |
| 259 | + |
| 260 | +} // end namespace serialization |
| 261 | +} // end namespace clang |
| 262 | + |
| 263 | +#endif |
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