llvm-6502/include/llvm/Support/YAMLParser.h
Rafael Espindola 34806d20dd yaml::Stream doesn't need to take ownership of the buffer.
In fact, most users were already using the StringRef version.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216575 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-27 19:03:22 +00:00

557 lines
15 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/SmallString.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/Allocator.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/SMLoc.h"
#include <limits>
#include <map>
#include <utility>
namespace llvm {
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 &);
Stream(MemoryBufferRef 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:
std::unique_ptr<Scanner> scanner;
std::unique_ptr<Document> CurrentDoc;
friend class Document;
};
/// \brief Abstract base class for all Nodes.
class Node {
virtual void anchor();
public:
enum NodeKind {
NK_Null,
NK_Scalar,
NK_KeyValue,
NK_Mapping,
NK_Sequence,
NK_Alias
};
Node(unsigned int Type, std::unique_ptr<Document> &, StringRef Anchor,
StringRef Tag);
/// \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; }
/// \brief Get the tag as it was written in the document. This does not
/// perform tag resolution.
StringRef getRawTag() const { return Tag; }
/// \brief Get the verbatium tag for a given Node. This performs tag resoluton
/// and substitution.
std::string getVerbatimTag() const;
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 Size) throw() {
Alloc.Deallocate(Ptr, Size);
}
protected:
std::unique_ptr<Document> &Doc;
SMRange SourceRange;
void operator delete(void *) throw() {}
virtual ~Node() {}
private:
unsigned int TypeID;
StringRef Anchor;
/// \brief The tag as typed in the document.
StringRef Tag;
};
/// \brief A null value.
///
/// Example:
/// !!null null
class NullNode : public Node {
void anchor() override;
public:
NullNode(std::unique_ptr<Document> &D)
: Node(NK_Null, D, StringRef(), 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 {
void anchor() override;
public:
ScalarNode(std::unique_ptr<Document> &D, StringRef Anchor, StringRef Tag,
StringRef Val)
: Node(NK_Scalar, D, Anchor, Tag), 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 {
void anchor() override;
public:
KeyValueNode(std::unique_ptr<Document> &D)
: Node(NK_KeyValue, D, StringRef(), StringRef()), Key(nullptr),
Value(nullptr) {}
/// \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();
void skip() 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(nullptr) {}
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)
Base = nullptr;
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 {
void anchor() override;
public:
enum MappingType {
MT_Block,
MT_Flow,
MT_Inline ///< An inline mapping node is used for "[key: value]".
};
MappingNode(std::unique_ptr<Document> &D, StringRef Anchor, StringRef Tag,
MappingType MT)
: Node(NK_Mapping, D, Anchor, Tag), Type(MT), IsAtBeginning(true),
IsAtEnd(false), CurrentEntry(nullptr) {}
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(); }
void skip() 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 {
void anchor() override;
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(std::unique_ptr<Document> &D, StringRef Anchor, StringRef Tag,
SequenceType ST)
: Node(NK_Sequence, D, Anchor, Tag), SeqType(ST), IsAtBeginning(true),
IsAtEnd(false),
WasPreviousTokenFlowEntry(true), // Start with an imaginary ','.
CurrentEntry(nullptr) {}
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(); }
void skip() 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 {
void anchor() override;
public:
AliasNode(std::unique_ptr<Document> &D, StringRef Val)
: Node(NK_Alias, D, StringRef(), 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();
}
const std::map<StringRef, StringRef> &getTagMap() const { return TagMap; }
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;
/// \brief Maps tag prefixes to their expansion.
std::map<StringRef, StringRef> TagMap;
Token &peekNext();
Token getNext();
void setError(const Twine &Message, Token &Location) const;
bool failed() const;
/// \brief Parse %BLAH directives and return true if any were encountered.
bool parseDirectives();
/// \brief Parse %YAML
void parseYAMLDirective();
/// \brief Parse %TAG
void parseTAGDirective();
/// \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(nullptr) {}
document_iterator(std::unique_ptr<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 && "incrementing iterator past the end.");
if (!(*Doc)->skip()) {
Doc->reset(nullptr);
} else {
Stream &S = (*Doc)->stream;
Doc->reset(new Document(S));
}
return *this;
}
Document &operator*() { return *Doc->get(); }
std::unique_ptr<Document> &operator->() { return *Doc; }
private:
bool isAtEnd() const { return !Doc || !*Doc; }
std::unique_ptr<Document> *Doc;
};
} // End namespace yaml.
} // End namespace llvm.
#endif