1 //===--- YAMLParser.h - Simple YAML parser --------------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This is a YAML 1.2 parser.
12 // See http://www.yaml.org/spec/1.2/spec.html for the full standard.
14 // This currently does not implement the following:
15 // * Multi-line literal folding.
18 // * BOMs anywhere other than the first Unicode scalar value in the file.
20 // The most important class here is Stream. This represents a YAML stream with
21 // 0, 1, or many documents.
24 // StringRef input = getInput();
25 // yaml::Stream stream(input, sm);
27 // for (yaml::document_iterator di = stream.begin(), de = stream.end();
29 // yaml::Node *n = di->getRoot();
31 // // Do something with n...
36 //===----------------------------------------------------------------------===//
38 #ifndef LLVM_SUPPORT_YAMLPARSER_H
39 #define LLVM_SUPPORT_YAMLPARSER_H
41 #include "llvm/ADT/SmallString.h"
42 #include "llvm/ADT/StringRef.h"
43 #include "llvm/Support/Allocator.h"
44 #include "llvm/Support/MemoryBuffer.h"
45 #include "llvm/Support/SMLoc.h"
57 class document_iterator;
63 /// \brief Dump all the tokens in this stream to OS.
64 /// \returns true if there was an error, false otherwise.
65 bool dumpTokens(StringRef Input, raw_ostream &);
67 /// \brief Scans all tokens in input without outputting anything. This is used
68 /// for benchmarking the tokenizer.
69 /// \returns true if there was an error, false otherwise.
70 bool scanTokens(StringRef Input);
72 /// \brief Escape \a Input for a double quoted scalar.
73 std::string escape(StringRef Input);
75 /// \brief This class represents a YAML stream potentially containing multiple
79 /// \brief This keeps a reference to the string referenced by \p Input.
80 Stream(StringRef Input, SourceMgr &);
82 Stream(MemoryBufferRef InputBuffer, SourceMgr &);
85 document_iterator begin();
86 document_iterator end();
94 void printError(Node *N, const Twine &Msg);
97 std::unique_ptr<Scanner> scanner;
98 std::unique_ptr<Document> CurrentDoc;
100 friend class Document;
103 /// \brief Abstract base class for all Nodes.
105 virtual void anchor();
117 Node(unsigned int Type, std::unique_ptr<Document> &, StringRef Anchor,
120 /// \brief Get the value of the anchor attached to this node. If it does not
121 /// have one, getAnchor().size() will be 0.
122 StringRef getAnchor() const { return Anchor; }
124 /// \brief Get the tag as it was written in the document. This does not
125 /// perform tag resolution.
126 StringRef getRawTag() const { return Tag; }
128 /// \brief Get the verbatium tag for a given Node. This performs tag resoluton
129 /// and substitution.
130 std::string getVerbatimTag() const;
132 SMRange getSourceRange() const { return SourceRange; }
133 void setSourceRange(SMRange SR) { SourceRange = SR; }
135 // These functions forward to Document and Scanner.
138 Node *parseBlockNode();
139 BumpPtrAllocator &getAllocator();
140 void setError(const Twine &Message, Token &Location) const;
143 virtual void skip() {}
145 unsigned int getType() const { return TypeID; }
147 void *operator new(size_t Size, BumpPtrAllocator &Alloc,
148 size_t Alignment = 16) throw() {
149 return Alloc.Allocate(Size, Alignment);
152 void operator delete(void *Ptr, BumpPtrAllocator &Alloc, size_t Size) throw() {
153 Alloc.Deallocate(Ptr, Size);
157 std::unique_ptr<Document> &Doc;
160 void operator delete(void *) throw() {}
167 /// \brief The tag as typed in the document.
171 /// \brief A null value.
175 class NullNode : public Node {
176 void anchor() override;
179 NullNode(std::unique_ptr<Document> &D)
180 : Node(NK_Null, D, StringRef(), StringRef()) {}
182 static inline bool classof(const Node *N) { return N->getType() == NK_Null; }
185 /// \brief A scalar node is an opaque datum that can be presented as a
186 /// series of zero or more Unicode scalar values.
190 class ScalarNode : public Node {
191 void anchor() override;
194 ScalarNode(std::unique_ptr<Document> &D, StringRef Anchor, StringRef Tag,
196 : Node(NK_Scalar, D, Anchor, Tag), Value(Val) {
197 SMLoc Start = SMLoc::getFromPointer(Val.begin());
198 SMLoc End = SMLoc::getFromPointer(Val.end());
199 SourceRange = SMRange(Start, End);
202 // Return Value without any escaping or folding or other fun YAML stuff. This
203 // is the exact bytes that are contained in the file (after conversion to
205 StringRef getRawValue() const { return Value; }
207 /// \brief Gets the value of this node as a StringRef.
209 /// \param Storage is used to store the content of the returned StringRef iff
210 /// it requires any modification from how it appeared in the source.
211 /// This happens with escaped characters and multi-line literals.
212 StringRef getValue(SmallVectorImpl<char> &Storage) const;
214 static inline bool classof(const Node *N) {
215 return N->getType() == NK_Scalar;
221 StringRef unescapeDoubleQuoted(StringRef UnquotedValue,
222 StringRef::size_type Start,
223 SmallVectorImpl<char> &Storage) const;
226 /// \brief A key and value pair. While not technically a Node under the YAML
227 /// representation graph, it is easier to treat them this way.
229 /// TODO: Consider making this not a child of Node.
233 class KeyValueNode : public Node {
234 void anchor() override;
237 KeyValueNode(std::unique_ptr<Document> &D)
238 : Node(NK_KeyValue, D, StringRef(), StringRef()), Key(nullptr),
241 /// \brief Parse and return the key.
243 /// This may be called multiple times.
245 /// \returns The key, or nullptr if failed() == true.
248 /// \brief Parse and return the value.
250 /// This may be called multiple times.
252 /// \returns The value, or nullptr if failed() == true.
255 void skip() override {
260 static inline bool classof(const Node *N) {
261 return N->getType() == NK_KeyValue;
269 /// \brief This is an iterator abstraction over YAML collections shared by both
270 /// sequences and maps.
272 /// BaseT must have a ValueT* member named CurrentEntry and a member function
273 /// increment() which must set CurrentEntry to 0 to create an end iterator.
274 template <class BaseT, class ValueT>
275 class basic_collection_iterator
276 : public std::iterator<std::forward_iterator_tag, ValueT> {
278 basic_collection_iterator() : Base(nullptr) {}
279 basic_collection_iterator(BaseT *B) : Base(B) {}
281 ValueT *operator->() const {
282 assert(Base && Base->CurrentEntry && "Attempted to access end iterator!");
283 return Base->CurrentEntry;
286 ValueT &operator*() const {
287 assert(Base && Base->CurrentEntry &&
288 "Attempted to dereference end iterator!");
289 return *Base->CurrentEntry;
292 operator ValueT *() const {
293 assert(Base && Base->CurrentEntry && "Attempted to access end iterator!");
294 return Base->CurrentEntry;
297 bool operator!=(const basic_collection_iterator &Other) const {
298 if (Base != Other.Base)
300 return (Base && Other.Base) &&
301 Base->CurrentEntry != Other.Base->CurrentEntry;
304 basic_collection_iterator &operator++() {
305 assert(Base && "Attempted to advance iterator past end!");
307 // Create an end iterator.
308 if (!Base->CurrentEntry)
317 // The following two templates are used for both MappingNode and Sequence Node.
318 template <class CollectionType>
319 typename CollectionType::iterator begin(CollectionType &C) {
320 assert(C.IsAtBeginning && "You may only iterate over a collection once!");
321 C.IsAtBeginning = false;
322 typename CollectionType::iterator ret(&C);
327 template <class CollectionType> void skip(CollectionType &C) {
328 // TODO: support skipping from the middle of a parsed collection ;/
329 assert((C.IsAtBeginning || C.IsAtEnd) && "Cannot skip mid parse!");
331 for (typename CollectionType::iterator i = begin(C), e = C.end(); i != e;
336 /// \brief Represents a YAML map created from either a block map for a flow map.
338 /// This parses the YAML stream as increment() is called.
343 class MappingNode : public Node {
344 void anchor() override;
350 MT_Inline ///< An inline mapping node is used for "[key: value]".
353 MappingNode(std::unique_ptr<Document> &D, StringRef Anchor, StringRef Tag,
355 : Node(NK_Mapping, D, Anchor, Tag), Type(MT), IsAtBeginning(true),
356 IsAtEnd(false), CurrentEntry(nullptr) {}
358 friend class basic_collection_iterator<MappingNode, KeyValueNode>;
359 typedef basic_collection_iterator<MappingNode, KeyValueNode> iterator;
360 template <class T> friend typename T::iterator yaml::begin(T &);
361 template <class T> friend void yaml::skip(T &);
363 iterator begin() { return yaml::begin(*this); }
365 iterator end() { return iterator(); }
367 void skip() override { yaml::skip(*this); }
369 static inline bool classof(const Node *N) {
370 return N->getType() == NK_Mapping;
377 KeyValueNode *CurrentEntry;
382 /// \brief Represents a YAML sequence created from either a block sequence for a
385 /// This parses the YAML stream as increment() is called.
390 class SequenceNode : public Node {
391 void anchor() override;
403 // As a BlockMappingEntry and BlockEnd are not created in this case.
407 SequenceNode(std::unique_ptr<Document> &D, StringRef Anchor, StringRef Tag,
409 : Node(NK_Sequence, D, Anchor, Tag), SeqType(ST), IsAtBeginning(true),
411 WasPreviousTokenFlowEntry(true), // Start with an imaginary ','.
412 CurrentEntry(nullptr) {}
414 friend class basic_collection_iterator<SequenceNode, Node>;
415 typedef basic_collection_iterator<SequenceNode, Node> iterator;
416 template <class T> friend typename T::iterator yaml::begin(T &);
417 template <class T> friend void yaml::skip(T &);
421 iterator begin() { return yaml::begin(*this); }
423 iterator end() { return iterator(); }
425 void skip() override { yaml::skip(*this); }
427 static inline bool classof(const Node *N) {
428 return N->getType() == NK_Sequence;
432 SequenceType SeqType;
435 bool WasPreviousTokenFlowEntry;
439 /// \brief Represents an alias to a Node with an anchor.
443 class AliasNode : public Node {
444 void anchor() override;
447 AliasNode(std::unique_ptr<Document> &D, StringRef Val)
448 : Node(NK_Alias, D, StringRef(), StringRef()), Name(Val) {}
450 StringRef getName() const { return Name; }
453 static inline bool classof(const Node *N) { return N->getType() == NK_Alias; }
459 /// \brief A YAML Stream is a sequence of Documents. A document contains a root
463 /// \brief Root for parsing a node. Returns a single node.
464 Node *parseBlockNode();
466 Document(Stream &ParentStream);
468 /// \brief Finish parsing the current document and return true if there are
469 /// more. Return false otherwise.
472 /// \brief Parse and return the root level node.
476 return Root = parseBlockNode();
479 const std::map<StringRef, StringRef> &getTagMap() const { return TagMap; }
483 friend class document_iterator;
485 /// \brief Stream to read tokens from.
488 /// \brief Used to allocate nodes to. All are destroyed without calling their
489 /// destructor when the document is destroyed.
490 BumpPtrAllocator NodeAllocator;
492 /// \brief The root node. Used to support skipping a partially parsed
496 /// \brief Maps tag prefixes to their expansion.
497 std::map<StringRef, StringRef> TagMap;
501 void setError(const Twine &Message, Token &Location) const;
504 /// \brief Parse %BLAH directives and return true if any were encountered.
505 bool parseDirectives();
507 /// \brief Parse %YAML
508 void parseYAMLDirective();
510 /// \brief Parse %TAG
511 void parseTAGDirective();
513 /// \brief Consume the next token and error if it is not \a TK.
514 bool expectToken(int TK);
517 /// \brief Iterator abstraction for Documents over a Stream.
518 class document_iterator {
520 document_iterator() : Doc(nullptr) {}
521 document_iterator(std::unique_ptr<Document> &D) : Doc(&D) {}
523 bool operator==(const document_iterator &Other) {
524 if (isAtEnd() || Other.isAtEnd())
525 return isAtEnd() && Other.isAtEnd();
527 return Doc == Other.Doc;
529 bool operator!=(const document_iterator &Other) { return !(*this == Other); }
531 document_iterator operator++() {
532 assert(Doc && "incrementing iterator past the end.");
533 if (!(*Doc)->skip()) {
536 Stream &S = (*Doc)->stream;
537 Doc->reset(new Document(S));
542 Document &operator*() { return *Doc->get(); }
544 std::unique_ptr<Document> &operator->() { return *Doc; }
547 bool isAtEnd() const { return !Doc || !*Doc; }
549 std::unique_ptr<Document> *Doc;
552 } // End namespace yaml.
554 } // End namespace llvm.