//==--- AbstractBasicWriter.h - Abstract basic value serialization --------===//
//
// 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
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CLANG_AST_ABSTRACTBASICWRITER_H
#define LLVM_CLANG_AST_ABSTRACTBASICWRITER_H
#include "clang/AST/ASTContext.h"
#include "clang/AST/DeclTemplate.h"
#include <optional>
namespace clang {
namespace serialization {
template <class T>
inline std::optional<T> makeOptionalFromNullable(const T &value) {
return (value.isNull() ? std::optional<T>() : std::optional<T>(value));
}
template <class T> inline std::optional<T *> makeOptionalFromPointer(T *value) {
return (value ? std::optional<T *>(value) : std::optional<T *>());
}
// PropertyWriter is a class concept that requires the following method:
// BasicWriter find(llvm::StringRef propertyName);
// where BasicWriter is some class conforming to the BasicWriter concept.
// An abstract AST-node writer is created with a PropertyWriter and
// performs a sequence of calls like so:
// propertyWriter.find(propertyName).write##TypeName(value)
// to write the properties of the node it is serializing.
// BasicWriter is a class concept that requires methods like:
// void write##TypeName(ValueType value);
// where TypeName is the name of a PropertyType node from PropertiesBase.td
// and ValueType is the corresponding C++ type name.
//
// In addition to the concrete property types, BasicWriter is expected
// to implement these methods:
//
// template <class EnumType>
// void writeEnum(T value);
//
// Writes an enum value as the current property. EnumType will always
// be an enum type. Only necessary if the BasicWriter doesn't provide
// type-specific writers for all the enum types.
//
// template <class ValueType>
// void writeOptional(std::optional<ValueType> value);
//
// Writes an optional value as the current property.
//
// template <class ValueType>
// void writeArray(ArrayRef<ValueType> value);
//
// Writes an array of values as the current property.
//
// PropertyWriter writeObject();
//
// Writes an object as the current property; the returned property
// writer will be subjected to a sequence of property writes and then
// discarded before any other properties are written to the "outer"
// property writer (which need not be the same type). The sub-writer
// will be used as if with the following code:
//
// {
// auto &&widget = W.find("widget").writeObject();
// widget.find("kind").writeWidgetKind(...);
// widget.find("declaration").writeDeclRef(...);
// }
// WriteDispatcher is a template which does type-based forwarding to one
// of the write methods of the BasicWriter passed in:
//
// template <class ValueType>
// struct WriteDispatcher {
// template <class BasicWriter>
// static void write(BasicWriter &W, ValueType value);
// };
// BasicWriterBase provides convenience implementations of the write
// methods for EnumPropertyType and SubclassPropertyType types that just
// defer to the "underlying" implementations (for UInt32 and the base class,
// respectively).
//
// template <class Impl>
// class BasicWriterBase {
// protected:
// Impl &asImpl();
// public:
// ...
// };
// The actual classes are auto-generated; see ClangASTPropertiesEmitter.cpp.
#include "clang/AST/AbstractBasicWriter.inc"
/// DataStreamBasicWriter provides convenience implementations for many
/// BasicWriter methods based on the assumption that the
/// ultimate writer implementation is based on a variable-length stream
/// of unstructured data (like Clang's module files). It is designed
/// to pair with DataStreamBasicReader.
///
/// This class can also act as a PropertyWriter, implementing find("...")
/// by simply forwarding to itself.
///
/// Unimplemented methods:
/// writeBool
/// writeUInt32
/// writeUInt64
/// writeIdentifier
/// writeSelector
/// writeSourceLocation
/// writeQualType
/// writeStmtRef
/// writeDeclRef
template <class Impl>
class DataStreamBasicWriter : public BasicWriterBase<Impl> {
protected:
using BasicWriterBase<Impl>::asImpl;
DataStreamBasicWriter(ASTContext &ctx) : BasicWriterBase<Impl>(ctx) {}
public:
/// Implement property-find by ignoring it. We rely on properties being
/// serialized and deserialized in a reliable order instead.
Impl &find(const char *propertyName) {
return asImpl();
}
// Implement object writing by forwarding to this, collapsing the
// structure into a single data stream.
Impl &writeObject() { return asImpl(); }
template <class T>
void writeEnum(T value) {
asImpl().writeUInt32(uint32_t(value));
}
template <class T>
void writeArray(llvm::ArrayRef<T> array) {
asImpl().writeUInt32(array.size());
for (const T &elt : array) {
WriteDispatcher<T>::write(asImpl(), elt);
}
}
template <class T> void writeOptional(std::optional<T> value) {
WriteDispatcher<T>::write(asImpl(), PackOptionalValue<T>::pack(value));
}
void writeAPSInt(const llvm::APSInt &value) {
asImpl().writeBool(value.isUnsigned());
asImpl().writeAPInt(value);
}
void writeAPInt(const llvm::APInt &value) {
asImpl().writeUInt32(value.getBitWidth());
const uint64_t *words = value.getRawData();
for (size_t i = 0, e = value.getNumWords(); i != e; ++i)
asImpl().writeUInt64(words[i]);
}
void writeFixedPointSemantics(const llvm::FixedPointSemantics &sema) {
asImpl().writeUInt32(sema.getWidth());
asImpl().writeUInt32(sema.getScale());
asImpl().writeUInt32(sema.isSigned() | sema.isSaturated() << 1 |
sema.hasUnsignedPadding() << 2);
}
void writeLValuePathSerializationHelper(
APValue::LValuePathSerializationHelper lvaluePath) {
ArrayRef<APValue::LValuePathEntry> path = lvaluePath.Path;
QualType elemTy = lvaluePath.getType();
asImpl().writeQualType(elemTy);
asImpl().writeUInt32(path.size());
auto &ctx = ((BasicWriterBase<Impl> *)this)->getASTContext();
for (auto elem : path) {
if (elemTy->getAs<RecordType>()) {
asImpl().writeUInt32(elem.getAsBaseOrMember().getInt());
const Decl *baseOrMember = elem.getAsBaseOrMember().getPointer();
if (const auto *recordDecl = dyn_cast<CXXRecordDecl>(baseOrMember)) {
asImpl().writeDeclRef(recordDecl);
elemTy = ctx.getRecordType(recordDecl);
} else {
const auto *valueDecl = cast<ValueDecl>(baseOrMember);
asImpl().writeDeclRef(valueDecl);
elemTy = valueDecl->getType();
}
} else {
asImpl().writeUInt32(elem.getAsArrayIndex());
elemTy = ctx.getAsArrayType(elemTy)->getElementType();
}
}
}
void writeQualifiers(Qualifiers value) {
static_assert(sizeof(value.getAsOpaqueValue()) <= sizeof(uint32_t),
"update this if the value size changes");
asImpl().writeUInt32(value.getAsOpaqueValue());
}
void writeExceptionSpecInfo(
const FunctionProtoType::ExceptionSpecInfo &esi) {
asImpl().writeUInt32(uint32_t(esi.Type));
if (esi.Type == EST_Dynamic) {
asImpl().writeArray(esi.Exceptions);
} else if (isComputedNoexcept(esi.Type)) {
asImpl().writeExprRef(esi.NoexceptExpr);
} else if (esi.Type == EST_Uninstantiated) {
asImpl().writeDeclRef(esi.SourceDecl);
asImpl().writeDeclRef(esi.SourceTemplate);
} else if (esi.Type == EST_Unevaluated) {
asImpl().writeDeclRef(esi.SourceDecl);
}
}
void writeExtParameterInfo(FunctionProtoType::ExtParameterInfo epi) {
static_assert(sizeof(epi.getOpaqueValue()) <= sizeof(uint32_t),
"opaque value doesn't fit into uint32_t");
asImpl().writeUInt32(epi.getOpaqueValue());
}
void writeNestedNameSpecifier(NestedNameSpecifier *NNS) {
// Nested name specifiers usually aren't too long. I think that 8 would
// typically accommodate the vast majority.
SmallVector<NestedNameSpecifier *, 8> nestedNames;
// Push each of the NNS's onto a stack for serialization in reverse order.
while (NNS) {
nestedNames.push_back(NNS);
NNS = NNS->getPrefix();
}
asImpl().writeUInt32(nestedNames.size());
while (!nestedNames.empty()) {
NNS = nestedNames.pop_back_val();
NestedNameSpecifier::SpecifierKind kind = NNS->getKind();
asImpl().writeNestedNameSpecifierKind(kind);
switch (kind) {
case NestedNameSpecifier::Identifier:
asImpl().writeIdentifier(NNS->getAsIdentifier());
continue;
case NestedNameSpecifier::Namespace:
asImpl().writeNamespaceDeclRef(NNS->getAsNamespace());
continue;
case NestedNameSpecifier::NamespaceAlias:
asImpl().writeNamespaceAliasDeclRef(NNS->getAsNamespaceAlias());
continue;
case NestedNameSpecifier::TypeSpec:
case NestedNameSpecifier::TypeSpecWithTemplate:
asImpl().writeQualType(QualType(NNS->getAsType(), 0));
continue;
case NestedNameSpecifier::Global:
// Don't need to write an associated value.
continue;
case NestedNameSpecifier::Super:
asImpl().writeDeclRef(NNS->getAsRecordDecl());
continue;
}
llvm_unreachable("bad nested name specifier kind");
}
}
};
} // end namespace serialization
} // end namespace clang
#endif