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Diffstat (limited to 'include/llvm/Support/YAMLParser.h')
| -rw-r--r-- | include/llvm/Support/YAMLParser.h | 564 |
1 files changed, 564 insertions, 0 deletions
diff --git a/include/llvm/Support/YAMLParser.h b/include/llvm/Support/YAMLParser.h new file mode 100644 index 000000000000..27d039164c16 --- /dev/null +++ b/include/llvm/Support/YAMLParser.h @@ -0,0 +1,564 @@ +//===--- YAMLParser.h - Simple YAML parser --------------------------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This is a YAML 1.2 parser. +// +// See http://www.yaml.org/spec/1.2/spec.html for the full standard. +// +// This currently does not implement the following: +// * Multi-line literal folding. +// * Tag resolution. +// * UTF-16. +// * BOMs anywhere other than the first Unicode scalar value in the file. +// +// The most important class here is Stream. This represents a YAML stream with +// 0, 1, or many documents. +// +// SourceMgr sm; +// StringRef input = getInput(); +// yaml::Stream stream(input, sm); +// +// for (yaml::document_iterator di = stream.begin(), de = stream.end(); +// di != de; ++di) { +// yaml::Node *n = di->getRoot(); +// if (n) { +// // Do something with n... +// } else +// break; +// } +// +//===----------------------------------------------------------------------===// + +#ifndef LLVM_SUPPORT_YAML_PARSER_H +#define LLVM_SUPPORT_YAML_PARSER_H + +#include "llvm/ADT/OwningPtr.h" +#include "llvm/ADT/SmallString.h" +#include "llvm/ADT/StringRef.h" +#include "llvm/Support/Allocator.h" +#include "llvm/Support/SMLoc.h" + +#include <limits> +#include <utility> + +namespace llvm { +class MemoryBuffer; +class SourceMgr; +class raw_ostream; +class Twine; + +namespace yaml { + +class document_iterator; +class Document; +class Node; +class Scanner; +struct Token; + +/// @brief Dump all the tokens in this stream to OS. +/// @returns true if there was an error, false otherwise. +bool dumpTokens(StringRef Input, raw_ostream &); + +/// @brief Scans all tokens in input without outputting anything. This is used +/// for benchmarking the tokenizer. +/// @returns true if there was an error, false otherwise. +bool scanTokens(StringRef Input); + +/// @brief Escape \a Input for a double quoted scalar. +std::string escape(StringRef Input); + +/// @brief This class represents a YAML stream potentially containing multiple +/// documents. +class Stream { +public: + Stream(StringRef Input, SourceMgr &); + + document_iterator begin(); + document_iterator end(); + void skip(); + bool failed(); + bool validate() { + skip(); + return !failed(); + } + + void printError(Node *N, const Twine &Msg); + +private: + OwningPtr<Scanner> scanner; + OwningPtr<Document> CurrentDoc; + + friend class Document; + + /// @brief Validate a %YAML x.x directive. + void handleYAMLDirective(const Token &); +}; + +/// @brief Abstract base class for all Nodes. +class Node { +public: + enum NodeKind { + NK_Null, + NK_Scalar, + NK_KeyValue, + NK_Mapping, + NK_Sequence, + NK_Alias + }; + + Node(unsigned int Type, OwningPtr<Document>&, StringRef Anchor); + virtual ~Node(); + + /// @brief Get the value of the anchor attached to this node. If it does not + /// have one, getAnchor().size() will be 0. + StringRef getAnchor() const { return Anchor; } + + SMRange getSourceRange() const { return SourceRange; } + void setSourceRange(SMRange SR) { SourceRange = SR; } + + // These functions forward to Document and Scanner. + Token &peekNext(); + Token getNext(); + Node *parseBlockNode(); + BumpPtrAllocator &getAllocator(); + void setError(const Twine &Message, Token &Location) const; + bool failed() const; + + virtual void skip() {}; + + unsigned int getType() const { return TypeID; } + static inline bool classof(const Node *) { return true; } + + void *operator new ( size_t Size + , BumpPtrAllocator &Alloc + , size_t Alignment = 16) throw() { + return Alloc.Allocate(Size, Alignment); + } + + void operator delete(void *Ptr, BumpPtrAllocator &Alloc, size_t) throw() { + Alloc.Deallocate(Ptr); + } + +protected: + OwningPtr<Document> &Doc; + SMRange SourceRange; + +private: + unsigned int TypeID; + StringRef Anchor; +}; + +/// @brief A null value. +/// +/// Example: +/// !!null null +class NullNode : public Node { +public: + NullNode(OwningPtr<Document> &D) : Node(NK_Null, D, StringRef()) {} + + static inline bool classof(const NullNode *) { return true; } + static inline bool classof(const Node *N) { + return N->getType() == NK_Null; + } +}; + +/// @brief A scalar node is an opaque datum that can be presented as a +/// series of zero or more Unicode scalar values. +/// +/// Example: +/// Adena +class ScalarNode : public Node { +public: + ScalarNode(OwningPtr<Document> &D, StringRef Anchor, StringRef Val) + : Node(NK_Scalar, D, Anchor) + , Value(Val) { + SMLoc Start = SMLoc::getFromPointer(Val.begin()); + SMLoc End = SMLoc::getFromPointer(Val.end() - 1); + SourceRange = SMRange(Start, End); + } + + // Return Value without any escaping or folding or other fun YAML stuff. This + // is the exact bytes that are contained in the file (after conversion to + // utf8). + StringRef getRawValue() const { return Value; } + + /// @brief Gets the value of this node as a StringRef. + /// + /// @param Storage is used to store the content of the returned StringRef iff + /// it requires any modification from how it appeared in the source. + /// This happens with escaped characters and multi-line literals. + StringRef getValue(SmallVectorImpl<char> &Storage) const; + + static inline bool classof(const ScalarNode *) { return true; } + static inline bool classof(const Node *N) { + return N->getType() == NK_Scalar; + } + +private: + StringRef Value; + + StringRef unescapeDoubleQuoted( StringRef UnquotedValue + , StringRef::size_type Start + , SmallVectorImpl<char> &Storage) const; +}; + +static bool getAs(const ScalarNode *SN, bool &Result) { + SmallString<4> Storage; + StringRef Value = SN->getValue(Storage); + if (Value == "true") + Result = true; + else if (Value == "false") + Result = false; + else + return false; + return true; +} + +template<class T> +typename enable_if_c<std::numeric_limits<T>::is_integer, bool>::type +getAs(const ScalarNode *SN, T &Result) { + SmallString<4> Storage; + return !SN->getValue(Storage).getAsInteger(0, Result); +} + +/// @brief A key and value pair. While not technically a Node under the YAML +/// representation graph, it is easier to treat them this way. +/// +/// TODO: Consider making this not a child of Node. +/// +/// Example: +/// Section: .text +class KeyValueNode : public Node { +public: + KeyValueNode(OwningPtr<Document> &D) + : Node(NK_KeyValue, D, StringRef()) + , Key(0) + , Value(0) + {} + + /// @brief Parse and return the key. + /// + /// This may be called multiple times. + /// + /// @returns The key, or nullptr if failed() == true. + Node *getKey(); + + /// @brief Parse and return the value. + /// + /// This may be called multiple times. + /// + /// @returns The value, or nullptr if failed() == true. + Node *getValue(); + + virtual void skip() { + getKey()->skip(); + getValue()->skip(); + } + + static inline bool classof(const KeyValueNode *) { return true; } + static inline bool classof(const Node *N) { + return N->getType() == NK_KeyValue; + } + +private: + Node *Key; + Node *Value; +}; + +/// @brief This is an iterator abstraction over YAML collections shared by both +/// sequences and maps. +/// +/// BaseT must have a ValueT* member named CurrentEntry and a member function +/// increment() which must set CurrentEntry to 0 to create an end iterator. +template <class BaseT, class ValueT> +class basic_collection_iterator + : public std::iterator<std::forward_iterator_tag, ValueT> { +public: + basic_collection_iterator() : Base(0) {} + basic_collection_iterator(BaseT *B) : Base(B) {} + + ValueT *operator ->() const { + assert(Base && Base->CurrentEntry && "Attempted to access end iterator!"); + return Base->CurrentEntry; + } + + ValueT &operator *() const { + assert(Base && Base->CurrentEntry && + "Attempted to dereference end iterator!"); + return *Base->CurrentEntry; + } + + operator ValueT*() const { + assert(Base && Base->CurrentEntry && "Attempted to access end iterator!"); + return Base->CurrentEntry; + } + + bool operator !=(const basic_collection_iterator &Other) const { + if(Base != Other.Base) + return true; + return (Base && Other.Base) && Base->CurrentEntry + != Other.Base->CurrentEntry; + } + + basic_collection_iterator &operator++() { + assert(Base && "Attempted to advance iterator past end!"); + Base->increment(); + // Create an end iterator. + if (Base->CurrentEntry == 0) + Base = 0; + return *this; + } + +private: + BaseT *Base; +}; + +// The following two templates are used for both MappingNode and Sequence Node. +template <class CollectionType> +typename CollectionType::iterator begin(CollectionType &C) { + assert(C.IsAtBeginning && "You may only iterate over a collection once!"); + C.IsAtBeginning = false; + typename CollectionType::iterator ret(&C); + ++ret; + return ret; +} + +template <class CollectionType> +void skip(CollectionType &C) { + // TODO: support skipping from the middle of a parsed collection ;/ + assert((C.IsAtBeginning || C.IsAtEnd) && "Cannot skip mid parse!"); + if (C.IsAtBeginning) + for (typename CollectionType::iterator i = begin(C), e = C.end(); + i != e; ++i) + i->skip(); +} + +/// @brief Represents a YAML map created from either a block map for a flow map. +/// +/// This parses the YAML stream as increment() is called. +/// +/// Example: +/// Name: _main +/// Scope: Global +class MappingNode : public Node { +public: + enum MappingType { + MT_Block, + MT_Flow, + MT_Inline //< An inline mapping node is used for "[key: value]". + }; + + MappingNode(OwningPtr<Document> &D, StringRef Anchor, MappingType MT) + : Node(NK_Mapping, D, Anchor) + , Type(MT) + , IsAtBeginning(true) + , IsAtEnd(false) + , CurrentEntry(0) + {} + + friend class basic_collection_iterator<MappingNode, KeyValueNode>; + typedef basic_collection_iterator<MappingNode, KeyValueNode> iterator; + template <class T> friend typename T::iterator yaml::begin(T &); + template <class T> friend void yaml::skip(T &); + + iterator begin() { + return yaml::begin(*this); + } + + iterator end() { return iterator(); } + + virtual void skip() { + yaml::skip(*this); + } + + static inline bool classof(const MappingNode *) { return true; } + static inline bool classof(const Node *N) { + return N->getType() == NK_Mapping; + } + +private: + MappingType Type; + bool IsAtBeginning; + bool IsAtEnd; + KeyValueNode *CurrentEntry; + + void increment(); +}; + +/// @brief Represents a YAML sequence created from either a block sequence for a +/// flow sequence. +/// +/// This parses the YAML stream as increment() is called. +/// +/// Example: +/// - Hello +/// - World +class SequenceNode : public Node { +public: + enum SequenceType { + ST_Block, + ST_Flow, + // Use for: + // + // key: + // - val1 + // - val2 + // + // As a BlockMappingEntry and BlockEnd are not created in this case. + ST_Indentless + }; + + SequenceNode(OwningPtr<Document> &D, StringRef Anchor, SequenceType ST) + : Node(NK_Sequence, D, Anchor) + , SeqType(ST) + , IsAtBeginning(true) + , IsAtEnd(false) + , WasPreviousTokenFlowEntry(true) // Start with an imaginary ','. + , CurrentEntry(0) + {} + + friend class basic_collection_iterator<SequenceNode, Node>; + typedef basic_collection_iterator<SequenceNode, Node> iterator; + template <class T> friend typename T::iterator yaml::begin(T &); + template <class T> friend void yaml::skip(T &); + + void increment(); + + iterator begin() { + return yaml::begin(*this); + } + + iterator end() { return iterator(); } + + virtual void skip() { + yaml::skip(*this); + } + + static inline bool classof(const SequenceNode *) { return true; } + static inline bool classof(const Node *N) { + return N->getType() == NK_Sequence; + } + +private: + SequenceType SeqType; + bool IsAtBeginning; + bool IsAtEnd; + bool WasPreviousTokenFlowEntry; + Node *CurrentEntry; +}; + +/// @brief Represents an alias to a Node with an anchor. +/// +/// Example: +/// *AnchorName +class AliasNode : public Node { +public: + AliasNode(OwningPtr<Document> &D, StringRef Val) + : Node(NK_Alias, D, StringRef()), Name(Val) {} + + StringRef getName() const { return Name; } + Node *getTarget(); + + static inline bool classof(const ScalarNode *) { return true; } + static inline bool classof(const Node *N) { + return N->getType() == NK_Alias; + } + +private: + StringRef Name; +}; + +/// @brief A YAML Stream is a sequence of Documents. A document contains a root +/// node. +class Document { +public: + /// @brief Root for parsing a node. Returns a single node. + Node *parseBlockNode(); + + Document(Stream &ParentStream); + + /// @brief Finish parsing the current document and return true if there are + /// more. Return false otherwise. + bool skip(); + + /// @brief Parse and return the root level node. + Node *getRoot() { + if (Root) + return Root; + return Root = parseBlockNode(); + } + +private: + friend class Node; + friend class document_iterator; + + /// @brief Stream to read tokens from. + Stream &stream; + + /// @brief Used to allocate nodes to. All are destroyed without calling their + /// destructor when the document is destroyed. + BumpPtrAllocator NodeAllocator; + + /// @brief The root node. Used to support skipping a partially parsed + /// document. + Node *Root; + + Token &peekNext(); + Token getNext(); + void setError(const Twine &Message, Token &Location) const; + bool failed() const; + + void handleTagDirective(const Token &Tag) { + // TODO: Track tags. + } + + /// @brief Parse %BLAH directives and return true if any were encountered. + bool parseDirectives(); + + /// @brief Consume the next token and error if it is not \a TK. + bool expectToken(int TK); +}; + +/// @brief Iterator abstraction for Documents over a Stream. +class document_iterator { +public: + document_iterator() : Doc(NullDoc) {} + document_iterator(OwningPtr<Document> &D) : Doc(D) {} + + bool operator !=(const document_iterator &Other) { + return Doc != Other.Doc; + } + + document_iterator operator ++() { + if (!Doc->skip()) { + Doc.reset(0); + } else { + Stream &S = Doc->stream; + Doc.reset(new Document(S)); + } + return *this; + } + + Document &operator *() { + return *Doc; + } + + OwningPtr<Document> &operator ->() { + return Doc; + } + +private: + static OwningPtr<Document> NullDoc; + OwningPtr<Document> &Doc; +}; + +} +} + +#endif |