llvm-6502/include/llvm/Support/YAMLParser.h
2013-01-10 00:45:19 +00:00

556 lines
14 KiB
C++

//===--- 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_YAMLPARSER_H
#define LLVM_SUPPORT_YAMLPARSER_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:
/// @brief This keeps a reference to the string referenced by \p Input.
Stream(StringRef Input, SourceMgr &);
/// @brief This takes ownership of \p InputBuffer.
Stream(MemoryBuffer *InputBuffer, SourceMgr &);
~Stream();
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);
/// @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; }
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;
void operator delete(void *) throw() {}
virtual ~Node() {}
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 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());
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 Node *N) {
return N->getType() == NK_Scalar;
}
private:
StringRef Value;
StringRef unescapeDoubleQuoted( StringRef UnquotedValue
, StringRef::size_type Start
, SmallVectorImpl<char> &Storage) const;
};
/// @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() LLVM_OVERRIDE {
getKey()->skip();
getValue()->skip();
}
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() LLVM_OVERRIDE {
yaml::skip(*this);
}
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() LLVM_OVERRIDE {
yaml::skip(*this);
}
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 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(0) {}
document_iterator(OwningPtr<Document> &D) : Doc(&D) {}
bool operator ==(const document_iterator &Other) {
if (isAtEnd() || Other.isAtEnd())
return isAtEnd() && Other.isAtEnd();
return *Doc == *Other.Doc;
}
bool operator !=(const document_iterator &Other) {
return !(*this == Other);
}
document_iterator operator ++() {
assert(Doc != 0 && "incrementing iterator past the end.");
if (!(*Doc)->skip()) {
Doc->reset(0);
} else {
Stream &S = (*Doc)->stream;
Doc->reset(new Document(S));
}
return *this;
}
Document &operator *() {
return *Doc->get();
}
OwningPtr<Document> &operator ->() {
return *Doc;
}
private:
bool isAtEnd() const {
return Doc == 0 || *Doc == 0;
}
OwningPtr<Document> *Doc;
};
}
}
#endif