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Diffstat (limited to 'src/jsregexp.h')
| -rw-r--r-- | src/jsregexp.h | 1283 |
1 files changed, 1283 insertions, 0 deletions
diff --git a/src/jsregexp.h b/src/jsregexp.h new file mode 100644 index 00000000..3bc30b6a --- /dev/null +++ b/src/jsregexp.h @@ -0,0 +1,1283 @@ +// Copyright 2006-2008 the V8 project authors. All rights reserved. +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions are +// met: +// +// * Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// * Redistributions in binary form must reproduce the above +// copyright notice, this list of conditions and the following +// disclaimer in the documentation and/or other materials provided +// with the distribution. +// * Neither the name of Google Inc. nor the names of its +// contributors may be used to endorse or promote products derived +// from this software without specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +#ifndef V8_JSREGEXP_H_ +#define V8_JSREGEXP_H_ + +namespace v8 { +namespace internal { + + +class RegExpMacroAssembler; + + +class RegExpImpl { + public: + // Whether V8 is compiled with native regexp support or not. + static bool UsesNativeRegExp() { +#ifdef V8_NATIVE_REGEXP + return true; +#else + return false; +#endif + } + + // Creates a regular expression literal in the old space. + // This function calls the garbage collector if necessary. + static Handle<Object> CreateRegExpLiteral(Handle<JSFunction> constructor, + Handle<String> pattern, + Handle<String> flags, + bool* has_pending_exception); + + // Returns a string representation of a regular expression. + // Implements RegExp.prototype.toString, see ECMA-262 section 15.10.6.4. + // This function calls the garbage collector if necessary. + static Handle<String> ToString(Handle<Object> value); + + // Parses the RegExp pattern and prepares the JSRegExp object with + // generic data and choice of implementation - as well as what + // the implementation wants to store in the data field. + // Returns false if compilation fails. + static Handle<Object> Compile(Handle<JSRegExp> re, + Handle<String> pattern, + Handle<String> flags); + + // See ECMA-262 section 15.10.6.2. + // This function calls the garbage collector if necessary. + static Handle<Object> Exec(Handle<JSRegExp> regexp, + Handle<String> subject, + int index, + Handle<JSArray> lastMatchInfo); + + // Call RegExp.prototyp.exec(string) in a loop. + // Used by String.prototype.match and String.prototype.replace. + // This function calls the garbage collector if necessary. + static Handle<Object> ExecGlobal(Handle<JSRegExp> regexp, + Handle<String> subject, + Handle<JSArray> lastMatchInfo); + + // Prepares a JSRegExp object with Irregexp-specific data. + static void IrregexpPrepare(Handle<JSRegExp> re, + Handle<String> pattern, + JSRegExp::Flags flags, + int capture_register_count); + + + static void AtomCompile(Handle<JSRegExp> re, + Handle<String> pattern, + JSRegExp::Flags flags, + Handle<String> match_pattern); + + static Handle<Object> AtomExec(Handle<JSRegExp> regexp, + Handle<String> subject, + int index, + Handle<JSArray> lastMatchInfo); + + // Execute an Irregexp bytecode pattern. + // On a successful match, the result is a JSArray containing + // captured positions. On a failure, the result is the null value. + // Returns an empty handle in case of an exception. + static Handle<Object> IrregexpExec(Handle<JSRegExp> regexp, + Handle<String> subject, + int index, + Handle<JSArray> lastMatchInfo); + + // Offsets in the lastMatchInfo array. + static const int kLastCaptureCount = 0; + static const int kLastSubject = 1; + static const int kLastInput = 2; + static const int kFirstCapture = 3; + static const int kLastMatchOverhead = 3; + + // Used to access the lastMatchInfo array. + static int GetCapture(FixedArray* array, int index) { + return Smi::cast(array->get(index + kFirstCapture))->value(); + } + + static void SetLastCaptureCount(FixedArray* array, int to) { + array->set(kLastCaptureCount, Smi::FromInt(to)); + } + + static void SetLastSubject(FixedArray* array, String* to) { + array->set(kLastSubject, to); + } + + static void SetLastInput(FixedArray* array, String* to) { + array->set(kLastInput, to); + } + + static void SetCapture(FixedArray* array, int index, int to) { + array->set(index + kFirstCapture, Smi::FromInt(to)); + } + + static int GetLastCaptureCount(FixedArray* array) { + return Smi::cast(array->get(kLastCaptureCount))->value(); + } + + // For acting on the JSRegExp data FixedArray. + static int IrregexpMaxRegisterCount(FixedArray* re); + static void SetIrregexpMaxRegisterCount(FixedArray* re, int value); + static int IrregexpNumberOfCaptures(FixedArray* re); + static int IrregexpNumberOfRegisters(FixedArray* re); + static ByteArray* IrregexpByteCode(FixedArray* re, bool is_ascii); + static Code* IrregexpNativeCode(FixedArray* re, bool is_ascii); + + private: + static String* last_ascii_string_; + static String* two_byte_cached_string_; + + static bool CompileIrregexp(Handle<JSRegExp> re, bool is_ascii); + static inline bool EnsureCompiledIrregexp(Handle<JSRegExp> re, bool is_ascii); + + + // Set the subject cache. The previous string buffer is not deleted, so the + // caller should ensure that it doesn't leak. + static void SetSubjectCache(String* subject, + char* utf8_subject, + int uft8_length, + int character_position, + int utf8_position); + + // A one element cache of the last utf8_subject string and its length. The + // subject JS String object is cached in the heap. We also cache a + // translation between position and utf8 position. + static char* utf8_subject_cache_; + static int utf8_length_cache_; + static int utf8_position_; + static int character_position_; +}; + + +class CharacterRange { + public: + CharacterRange() : from_(0), to_(0) { } + // For compatibility with the CHECK_OK macro + CharacterRange(void* null) { ASSERT_EQ(NULL, null); } //NOLINT + CharacterRange(uc16 from, uc16 to) : from_(from), to_(to) { } + static void AddClassEscape(uc16 type, ZoneList<CharacterRange>* ranges); + static Vector<const uc16> GetWordBounds(); + static inline CharacterRange Singleton(uc16 value) { + return CharacterRange(value, value); + } + static inline CharacterRange Range(uc16 from, uc16 to) { + ASSERT(from <= to); + return CharacterRange(from, to); + } + static inline CharacterRange Everything() { + return CharacterRange(0, 0xFFFF); + } + bool Contains(uc16 i) { return from_ <= i && i <= to_; } + uc16 from() const { return from_; } + void set_from(uc16 value) { from_ = value; } + uc16 to() const { return to_; } + void set_to(uc16 value) { to_ = value; } + bool is_valid() { return from_ <= to_; } + bool IsEverything(uc16 max) { return from_ == 0 && to_ >= max; } + bool IsSingleton() { return (from_ == to_); } + void AddCaseEquivalents(ZoneList<CharacterRange>* ranges); + static void Split(ZoneList<CharacterRange>* base, + Vector<const uc16> overlay, + ZoneList<CharacterRange>** included, + ZoneList<CharacterRange>** excluded); + + static const int kRangeCanonicalizeMax = 0x346; + static const int kStartMarker = (1 << 24); + static const int kPayloadMask = (1 << 24) - 1; + + private: + uc16 from_; + uc16 to_; +}; + + +// A set of unsigned integers that behaves especially well on small +// integers (< 32). May do zone-allocation. +class OutSet: public ZoneObject { + public: + OutSet() : first_(0), remaining_(NULL), successors_(NULL) { } + OutSet* Extend(unsigned value); + bool Get(unsigned value); + static const unsigned kFirstLimit = 32; + + private: + // Destructively set a value in this set. In most cases you want + // to use Extend instead to ensure that only one instance exists + // that contains the same values. + void Set(unsigned value); + + // The successors are a list of sets that contain the same values + // as this set and the one more value that is not present in this + // set. + ZoneList<OutSet*>* successors() { return successors_; } + + OutSet(uint32_t first, ZoneList<unsigned>* remaining) + : first_(first), remaining_(remaining), successors_(NULL) { } + uint32_t first_; + ZoneList<unsigned>* remaining_; + ZoneList<OutSet*>* successors_; + friend class Trace; +}; + + +// A mapping from integers, specified as ranges, to a set of integers. +// Used for mapping character ranges to choices. +class DispatchTable : public ZoneObject { + public: + class Entry { + public: + Entry() : from_(0), to_(0), out_set_(NULL) { } + Entry(uc16 from, uc16 to, OutSet* out_set) + : from_(from), to_(to), out_set_(out_set) { } + uc16 from() { return from_; } + uc16 to() { return to_; } + void set_to(uc16 value) { to_ = value; } + void AddValue(int value) { out_set_ = out_set_->Extend(value); } + OutSet* out_set() { return out_set_; } + private: + uc16 from_; + uc16 to_; + OutSet* out_set_; + }; + + class Config { + public: + typedef uc16 Key; + typedef Entry Value; + static const uc16 kNoKey; + static const Entry kNoValue; + static inline int Compare(uc16 a, uc16 b) { + if (a == b) + return 0; + else if (a < b) + return -1; + else + return 1; + } + }; + + void AddRange(CharacterRange range, int value); + OutSet* Get(uc16 value); + void Dump(); + + template <typename Callback> + void ForEach(Callback* callback) { return tree()->ForEach(callback); } + private: + // There can't be a static empty set since it allocates its + // successors in a zone and caches them. + OutSet* empty() { return &empty_; } + OutSet empty_; + ZoneSplayTree<Config>* tree() { return &tree_; } + ZoneSplayTree<Config> tree_; +}; + + +#define FOR_EACH_NODE_TYPE(VISIT) \ + VISIT(End) \ + VISIT(Action) \ + VISIT(Choice) \ + VISIT(BackReference) \ + VISIT(Assertion) \ + VISIT(Text) + + +#define FOR_EACH_REG_EXP_TREE_TYPE(VISIT) \ + VISIT(Disjunction) \ + VISIT(Alternative) \ + VISIT(Assertion) \ + VISIT(CharacterClass) \ + VISIT(Atom) \ + VISIT(Quantifier) \ + VISIT(Capture) \ + VISIT(Lookahead) \ + VISIT(BackReference) \ + VISIT(Empty) \ + VISIT(Text) + + +#define FORWARD_DECLARE(Name) class RegExp##Name; +FOR_EACH_REG_EXP_TREE_TYPE(FORWARD_DECLARE) +#undef FORWARD_DECLARE + + +class TextElement { + public: + enum Type {UNINITIALIZED, ATOM, CHAR_CLASS}; + TextElement() : type(UNINITIALIZED) { } + explicit TextElement(Type t) : type(t), cp_offset(-1) { } + static TextElement Atom(RegExpAtom* atom); + static TextElement CharClass(RegExpCharacterClass* char_class); + int length(); + Type type; + union { + RegExpAtom* u_atom; + RegExpCharacterClass* u_char_class; + } data; + int cp_offset; +}; + + +class Trace; + + +struct NodeInfo { + NodeInfo() + : being_analyzed(false), + been_analyzed(false), + follows_word_interest(false), + follows_newline_interest(false), + follows_start_interest(false), + at_end(false), + visited(false) { } + + // Returns true if the interests and assumptions of this node + // matches the given one. + bool Matches(NodeInfo* that) { + return (at_end == that->at_end) && + (follows_word_interest == that->follows_word_interest) && + (follows_newline_interest == that->follows_newline_interest) && + (follows_start_interest == that->follows_start_interest); + } + + // Updates the interests of this node given the interests of the + // node preceding it. + void AddFromPreceding(NodeInfo* that) { + at_end |= that->at_end; + follows_word_interest |= that->follows_word_interest; + follows_newline_interest |= that->follows_newline_interest; + follows_start_interest |= that->follows_start_interest; + } + + bool HasLookbehind() { + return follows_word_interest || + follows_newline_interest || + follows_start_interest; + } + + // Sets the interests of this node to include the interests of the + // following node. + void AddFromFollowing(NodeInfo* that) { + follows_word_interest |= that->follows_word_interest; + follows_newline_interest |= that->follows_newline_interest; + follows_start_interest |= that->follows_start_interest; + } + + void ResetCompilationState() { + being_analyzed = false; + been_analyzed = false; + } + + bool being_analyzed: 1; + bool been_analyzed: 1; + + // These bits are set of this node has to know what the preceding + // character was. + bool follows_word_interest: 1; + bool follows_newline_interest: 1; + bool follows_start_interest: 1; + + bool at_end: 1; + bool visited: 1; +}; + + +class SiblingList { + public: + SiblingList() : list_(NULL) { } + int length() { + return list_ == NULL ? 0 : list_->length(); + } + void Ensure(RegExpNode* parent) { + if (list_ == NULL) { + list_ = new ZoneList<RegExpNode*>(2); + list_->Add(parent); + } + } + void Add(RegExpNode* node) { list_->Add(node); } + RegExpNode* Get(int index) { return list_->at(index); } + private: + ZoneList<RegExpNode*>* list_; +}; + + +// Details of a quick mask-compare check that can look ahead in the +// input stream. +class QuickCheckDetails { + public: + QuickCheckDetails() + : characters_(0), + mask_(0), + value_(0), + cannot_match_(false) { } + explicit QuickCheckDetails(int characters) + : characters_(characters), + mask_(0), + value_(0), + cannot_match_(false) { } + bool Rationalize(bool ascii); + // Merge in the information from another branch of an alternation. + void Merge(QuickCheckDetails* other, int from_index); + // Advance the current position by some amount. + void Advance(int by, bool ascii); + void Clear(); + bool cannot_match() { return cannot_match_; } + void set_cannot_match() { cannot_match_ = true; } + struct Position { + Position() : mask(0), value(0), determines_perfectly(false) { } + uc16 mask; + uc16 value; + bool determines_perfectly; + }; + int characters() { return characters_; } + void set_characters(int characters) { characters_ = characters; } + Position* positions(int index) { + ASSERT(index >= 0); + ASSERT(index < characters_); + return positions_ + index; + } + uint32_t mask() { return mask_; } + uint32_t value() { return value_; } + + private: + // How many characters do we have quick check information from. This is + // the same for all branches of a choice node. + int characters_; + Position positions_[4]; + // These values are the condensate of the above array after Rationalize(). + uint32_t mask_; + uint32_t value_; + // If set to true, there is no way this quick check can match at all. + // E.g., if it requires to be at the start of the input, and isn't. + bool cannot_match_; +}; + + +class RegExpNode: public ZoneObject { + public: + RegExpNode() : trace_count_(0) { } + virtual ~RegExpNode(); + virtual void Accept(NodeVisitor* visitor) = 0; + // Generates a goto to this node or actually generates the code at this point. + virtual void Emit(RegExpCompiler* compiler, Trace* trace) = 0; + // How many characters must this node consume at a minimum in order to + // succeed. If we have found at least 'still_to_find' characters that + // must be consumed there is no need to ask any following nodes whether + // they are sure to eat any more characters. + virtual int EatsAtLeast(int still_to_find, int recursion_depth) = 0; + // Emits some quick code that checks whether the preloaded characters match. + // Falls through on certain failure, jumps to the label on possible success. + // If the node cannot make a quick check it does nothing and returns false. + bool EmitQuickCheck(RegExpCompiler* compiler, + Trace* trace, + bool preload_has_checked_bounds, + Label* on_possible_success, + QuickCheckDetails* details_return, + bool fall_through_on_failure); + // For a given number of characters this returns a mask and a value. The + // next n characters are anded with the mask and compared with the value. + // A comparison failure indicates the node cannot match the next n characters. + // A comparison success indicates the node may match. + virtual void GetQuickCheckDetails(QuickCheckDetails* details, + RegExpCompiler* compiler, + int characters_filled_in, + bool not_at_start) = 0; + static const int kNodeIsTooComplexForGreedyLoops = -1; + virtual int GreedyLoopTextLength() { return kNodeIsTooComplexForGreedyLoops; } + Label* label() { return &label_; } + // If non-generic code is generated for a node (ie the node is not at the + // start of the trace) then it cannot be reused. This variable sets a limit + // on how often we allow that to happen before we insist on starting a new + // trace and generating generic code for a node that can be reused by flushing + // the deferred actions in the current trace and generating a goto. + static const int kMaxCopiesCodeGenerated = 10; + + NodeInfo* info() { return &info_; } + + void AddSibling(RegExpNode* node) { siblings_.Add(node); } + + // Static version of EnsureSibling that expresses the fact that the + // result has the same type as the input. + template <class C> + static C* EnsureSibling(C* node, NodeInfo* info, bool* cloned) { + return static_cast<C*>(node->EnsureSibling(info, cloned)); + } + + SiblingList* siblings() { return &siblings_; } + void set_siblings(SiblingList* other) { siblings_ = *other; } + + protected: + enum LimitResult { DONE, CONTINUE }; + LimitResult LimitVersions(RegExpCompiler* compiler, Trace* trace); + + // Returns a sibling of this node whose interests and assumptions + // match the ones in the given node info. If no sibling exists NULL + // is returned. + RegExpNode* TryGetSibling(NodeInfo* info); + + // Returns a sibling of this node whose interests match the ones in + // the given node info. The info must not contain any assertions. + // If no node exists a new one will be created by cloning the current + // node. The result will always be an instance of the same concrete + // class as this node. + RegExpNode* EnsureSibling(NodeInfo* info, bool* cloned); + + // Returns a clone of this node initialized using the copy constructor + // of its concrete class. Note that the node may have to be pre- + // processed before it is on a usable state. + virtual RegExpNode* Clone() = 0; + + private: + Label label_; + NodeInfo info_; + SiblingList siblings_; + // This variable keeps track of how many times code has been generated for + // this node (in different traces). We don't keep track of where the + // generated code is located unless the code is generated at the start of + // a trace, in which case it is generic and can be reused by flushing the + // deferred operations in the current trace and generating a goto. + int trace_count_; +}; + + +// A simple closed interval. +class Interval { + public: + Interval() : from_(kNone), to_(kNone) { } + Interval(int from, int to) : from_(from), to_(to) { } + Interval Union(Interval that) { + if (that.from_ == kNone) + return *this; + else if (from_ == kNone) + return that; + else + return Interval(Min(from_, that.from_), Max(to_, that.to_)); + } + bool Contains(int value) { + return (from_ <= value) && (value <= to_); + } + bool is_empty() { return from_ == kNone; } + int from() { return from_; } + int to() { return to_; } + static Interval Empty() { return Interval(); } + static const int kNone = -1; + private: + int from_; + int to_; +}; + + +class SeqRegExpNode: public RegExpNode { + public: + explicit SeqRegExpNode(RegExpNode* on_success) + : on_success_(on_success) { } + RegExpNode* on_success() { return on_success_; } + void set_on_success(RegExpNode* node) { on_success_ = node; } + private: + RegExpNode* on_success_; +}; + + +class ActionNode: public SeqRegExpNode { + public: + enum Type { + SET_REGISTER, + INCREMENT_REGISTER, + STORE_POSITION, + BEGIN_SUBMATCH, + POSITIVE_SUBMATCH_SUCCESS, + EMPTY_MATCH_CHECK, + CLEAR_CAPTURES + }; + static ActionNode* SetRegister(int reg, int val, RegExpNode* on_success); + static ActionNode* IncrementRegister(int reg, RegExpNode* on_success); + static ActionNode* StorePosition(int reg, + bool is_capture, + RegExpNode* on_success); + static ActionNode* ClearCaptures(Interval range, RegExpNode* on_success); + static ActionNode* BeginSubmatch(int stack_pointer_reg, + int position_reg, + RegExpNode* on_success); + static ActionNode* PositiveSubmatchSuccess(int stack_pointer_reg, + int restore_reg, + int clear_capture_count, + int clear_capture_from, + RegExpNode* on_success); + static ActionNode* EmptyMatchCheck(int start_register, + int repetition_register, + int repetition_limit, + RegExpNode* on_success); + virtual void Accept(NodeVisitor* visitor); + virtual void Emit(RegExpCompiler* compiler, Trace* trace); + virtual int EatsAtLeast(int still_to_find, int recursion_depth); + virtual void GetQuickCheckDetails(QuickCheckDetails* details, + RegExpCompiler* compiler, + int filled_in, + bool not_at_start) { + return on_success()->GetQuickCheckDetails( + details, compiler, filled_in, not_at_start); + } + Type type() { return type_; } + // TODO(erikcorry): We should allow some action nodes in greedy loops. + virtual int GreedyLoopTextLength() { return kNodeIsTooComplexForGreedyLoops; } + virtual ActionNode* Clone() { return new ActionNode(*this); } + + private: + union { + struct { + int reg; + int value; + } u_store_register; + struct { + int reg; + } u_increment_register; + struct { + int reg; + bool is_capture; + } u_position_register; + struct { + int stack_pointer_register; + int current_position_register; + int clear_register_count; + int clear_register_from; + } u_submatch; + struct { + int start_register; + int repetition_register; + int repetition_limit; + } u_empty_match_check; + struct { + int range_from; + int range_to; + } u_clear_captures; + } data_; + ActionNode(Type type, RegExpNode* on_success) + : SeqRegExpNode(on_success), + type_(type) { } + Type type_; + friend class DotPrinter; +}; + + +class TextNode: public SeqRegExpNode { + public: + TextNode(ZoneList<TextElement>* elms, + RegExpNode* on_success) + : SeqRegExpNode(on_success), + elms_(elms) { } + TextNode(RegExpCharacterClass* that, + RegExpNode* on_success) + : SeqRegExpNode(on_success), + elms_(new ZoneList<TextElement>(1)) { + elms_->Add(TextElement::CharClass(that)); + } + virtual void Accept(NodeVisitor* visitor); + virtual void Emit(RegExpCompiler* compiler, Trace* trace); + virtual int EatsAtLeast(int still_to_find, int recursion_depth); + virtual void GetQuickCheckDetails(QuickCheckDetails* details, + RegExpCompiler* compiler, + int characters_filled_in, + bool not_at_start); + ZoneList<TextElement>* elements() { return elms_; } + void MakeCaseIndependent(); + virtual int GreedyLoopTextLength(); + virtual TextNode* Clone() { + TextNode* result = new TextNode(*this); + result->CalculateOffsets(); + return result; + } + void CalculateOffsets(); + + private: + enum TextEmitPassType { + NON_ASCII_MATCH, // Check for characters that can't match. + SIMPLE_CHARACTER_MATCH, // Case-dependent single character check. + NON_LETTER_CHARACTER_MATCH, // Check characters that have no case equivs. + CASE_CHARACTER_MATCH, // Case-independent single character check. + CHARACTER_CLASS_MATCH // Character class. + }; + static bool SkipPass(int pass, bool ignore_case); + static const int kFirstRealPass = SIMPLE_CHARACTER_MATCH; + static const int kLastPass = CHARACTER_CLASS_MATCH; + void TextEmitPass(RegExpCompiler* compiler, + TextEmitPassType pass, + bool preloaded, + Trace* trace, + bool first_element_checked, + int* checked_up_to); + int Length(); + ZoneList<TextElement>* elms_; +}; + + +class AssertionNode: public SeqRegExpNode { + public: + enum AssertionNodeType { + AT_END, + AT_START, + AT_BOUNDARY, + AT_NON_BOUNDARY, + AFTER_NEWLINE + }; + static AssertionNode* AtEnd(RegExpNode* on_success) { + return new AssertionNode(AT_END, on_success); + } + static AssertionNode* AtStart(RegExpNode* on_success) { + return new AssertionNode(AT_START, on_success); + } + static AssertionNode* AtBoundary(RegExpNode* on_success) { + return new AssertionNode(AT_BOUNDARY, on_success); + } + static AssertionNode* AtNonBoundary(RegExpNode* on_success) { + return new AssertionNode(AT_NON_BOUNDARY, on_success); + } + static AssertionNode* AfterNewline(RegExpNode* on_success) { + return new AssertionNode(AFTER_NEWLINE, on_success); + } + virtual void Accept(NodeVisitor* visitor); + virtual void Emit(RegExpCompiler* compiler, Trace* trace); + virtual int EatsAtLeast(int still_to_find, int recursion_depth); + virtual void GetQuickCheckDetails(QuickCheckDetails* details, + RegExpCompiler* compiler, + int filled_in, + bool not_at_start); + virtual AssertionNode* Clone() { return new AssertionNode(*this); } + AssertionNodeType type() { return type_; } + private: + AssertionNode(AssertionNodeType t, RegExpNode* on_success) + : SeqRegExpNode(on_success), type_(t) { } + AssertionNodeType type_; +}; + + +class BackReferenceNode: public SeqRegExpNode { + public: + BackReferenceNode(int start_reg, + int end_reg, + RegExpNode* on_success) + : SeqRegExpNode(on_success), + start_reg_(start_reg), + end_reg_(end_reg) { } + virtual void Accept(NodeVisitor* visitor); + int start_register() { return start_reg_; } + int end_register() { return end_reg_; } + virtual void Emit(RegExpCompiler* compiler, Trace* trace); + virtual int EatsAtLeast(int still_to_find, int recursion_depth); + virtual void GetQuickCheckDetails(QuickCheckDetails* details, + RegExpCompiler* compiler, + int characters_filled_in, + bool not_at_start) { + return; + } + virtual BackReferenceNode* Clone() { return new BackReferenceNode(*this); } + + private: + int start_reg_; + int end_reg_; +}; + + +class EndNode: public RegExpNode { + public: + enum Action { ACCEPT, BACKTRACK, NEGATIVE_SUBMATCH_SUCCESS }; + explicit EndNode(Action action) : action_(action) { } + virtual void Accept(NodeVisitor* visitor); + virtual void Emit(RegExpCompiler* compiler, Trace* trace); + virtual int EatsAtLeast(int still_to_find, int recursion_depth) { return 0; } + virtual void GetQuickCheckDetails(QuickCheckDetails* details, + RegExpCompiler* compiler, + int characters_filled_in, + bool not_at_start) { + // Returning 0 from EatsAtLeast should ensure we never get here. + UNREACHABLE(); + } + virtual EndNode* Clone() { return new EndNode(*this); } + + private: + Action action_; +}; + + +class NegativeSubmatchSuccess: public EndNode { + public: + NegativeSubmatchSuccess(int stack_pointer_reg, + int position_reg, + int clear_capture_count, + int clear_capture_start) + : EndNode(NEGATIVE_SUBMATCH_SUCCESS), + stack_pointer_register_(stack_pointer_reg), + current_position_register_(position_reg), + clear_capture_count_(clear_capture_count), + clear_capture_start_(clear_capture_start) { } + virtual void Emit(RegExpCompiler* compiler, Trace* trace); + + private: + int stack_pointer_register_; + int current_position_register_; + int clear_capture_count_; + int clear_capture_start_; +}; + + +class Guard: public ZoneObject { + public: + enum Relation { LT, GEQ }; + Guard(int reg, Relation op, int value) + : reg_(reg), + op_(op), + value_(value) { } + int reg() { return reg_; } + Relation op() { return op_; } + int value() { return value_; } + + private: + int reg_; + Relation op_; + int value_; +}; + + +class GuardedAlternative { + public: + explicit GuardedAlternative(RegExpNode* node) : node_(node), guards_(NULL) { } + void AddGuard(Guard* guard); + RegExpNode* node() { return node_; } + void set_node(RegExpNode* node) { node_ = node; } + ZoneList<Guard*>* guards() { return guards_; } + + private: + RegExpNode* node_; + ZoneList<Guard*>* guards_; +}; + + +class AlternativeGeneration; + + +class ChoiceNode: public RegExpNode { + public: + explicit ChoiceNode(int expected_size) + : alternatives_(new ZoneList<GuardedAlternative>(expected_size)), + table_(NULL), + not_at_start_(false), + being_calculated_(false) { } + virtual void Accept(NodeVisitor* visitor); + void AddAlternative(GuardedAlternative node) { alternatives()->Add(node); } + ZoneList<GuardedAlternative>* alternatives() { return alternatives_; } + DispatchTable* GetTable(bool ignore_case); + virtual void Emit(RegExpCompiler* compiler, Trace* trace); + virtual int EatsAtLeast(int still_to_find, int recursion_depth); + int EatsAtLeastHelper(int still_to_find, + int recursion_depth, + RegExpNode* ignore_this_node); + virtual void GetQuickCheckDetails(QuickCheckDetails* details, + RegExpCompiler* compiler, + int characters_filled_in, + bool not_at_start); + virtual ChoiceNode* Clone() { return new ChoiceNode(*this); } + + bool being_calculated() { return being_calculated_; } + bool not_at_start() { return not_at_start_; } + void set_not_at_start() { not_at_start_ = true; } + void set_being_calculated(bool b) { being_calculated_ = b; } + virtual bool try_to_emit_quick_check_for_alternative(int i) { return true; } + + protected: + int GreedyLoopTextLength(GuardedAlternative* alternative); + ZoneList<GuardedAlternative>* alternatives_; + + private: + friend class DispatchTableConstructor; + friend class Analysis; + void GenerateGuard(RegExpMacroAssembler* macro_assembler, + Guard* guard, + Trace* trace); + int CalculatePreloadCharacters(RegExpCompiler* compiler); + void EmitOutOfLineContinuation(RegExpCompiler* compiler, + Trace* trace, + GuardedAlternative alternative, + AlternativeGeneration* alt_gen, + int preload_characters, + bool next_expects_preload); + DispatchTable* table_; + // If true, this node is never checked at the start of the input. + // Allows a new trace to start with at_start() set to false. + bool not_at_start_; + bool being_calculated_; +}; + + +class NegativeLookaheadChoiceNode: public ChoiceNode { + public: + explicit NegativeLookaheadChoiceNode(GuardedAlternative this_must_fail, + GuardedAlternative then_do_this) + : ChoiceNode(2) { + AddAlternative(this_must_fail); + AddAlternative(then_do_this); + } + virtual int EatsAtLeast(int still_to_find, int recursion_depth); + virtual void GetQuickCheckDetails(QuickCheckDetails* details, + RegExpCompiler* compiler, + int characters_filled_in, + bool not_at_start); + // For a negative lookahead we don't emit the quick check for the + // alternative that is expected to fail. This is because quick check code + // starts by loading enough characters for the alternative that takes fewest + // characters, but on a negative lookahead the negative branch did not take + // part in that calculation (EatsAtLeast) so the assumptions don't hold. + virtual bool try_to_emit_quick_check_for_alternative(int i) { return i != 0; } +}; + + +class LoopChoiceNode: public ChoiceNode { + public: + explicit LoopChoiceNode(bool body_can_be_zero_length) + : ChoiceNode(2), + loop_node_(NULL), + continue_node_(NULL), + body_can_be_zero_length_(body_can_be_zero_length) { } + void AddLoopAlternative(GuardedAlternative alt); + void AddContinueAlternative(GuardedAlternative alt); + virtual void Emit(RegExpCompiler* compiler, Trace* trace); + virtual int EatsAtLeast(int still_to_find, int recursion_depth); + virtual void GetQuickCheckDetails(QuickCheckDetails* details, + RegExpCompiler* compiler, + int characters_filled_in, + bool not_at_start); + virtual LoopChoiceNode* Clone() { return new LoopChoiceNode(*this); } + RegExpNode* loop_node() { return loop_node_; } + RegExpNode* continue_node() { return continue_node_; } + bool body_can_be_zero_length() { return body_can_be_zero_length_; } + virtual void Accept(NodeVisitor* visitor); + + private: + // AddAlternative is made private for loop nodes because alternatives + // should not be added freely, we need to keep track of which node + // goes back to the node itself. + void AddAlternative(GuardedAlternative node) { + ChoiceNode::AddAlternative(node); + } + + RegExpNode* loop_node_; + RegExpNode* continue_node_; + bool body_can_be_zero_length_; +}; + + +// There are many ways to generate code for a node. This class encapsulates +// the current way we should be generating. In other words it encapsulates +// the current state of the code generator. The effect of this is that we +// generate code for paths that the matcher can take through the regular +// expression. A given node in the regexp can be code-generated several times +// as it can be part of several traces. For example for the regexp: +// /foo(bar|ip)baz/ the code to match baz will be generated twice, once as part +// of the foo-bar-baz trace and once as part of the foo-ip-baz trace. The code +// to match foo is generated only once (the traces have a common prefix). The +// code to store the capture is deferred and generated (twice) after the places +// where baz has been matched. +class Trace { + public: + // A value for a property that is either known to be true, know to be false, + // or not known. + enum TriBool { + UNKNOWN = -1, FALSE = 0, TRUE = 1 + }; + + class DeferredAction { + public: + DeferredAction(ActionNode::Type type, int reg) + : type_(type), reg_(reg), next_(NULL) { } + DeferredAction* next() { return next_; } + bool Mentions(int reg); + int reg() { return reg_; } + ActionNode::Type type() { return type_; } + private: + ActionNode::Type type_; + int reg_; + DeferredAction* next_; + friend class Trace; + }; + + class DeferredCapture : public DeferredAction { + public: + DeferredCapture(int reg, bool is_capture, Trace* trace) + : DeferredAction(ActionNode::STORE_POSITION, reg), + cp_offset_(trace->cp_offset()), + is_capture_(is_capture) { } + int cp_offset() { return cp_offset_; } + bool is_capture() { return is_capture_; } + private: + int cp_offset_; + bool is_capture_; + void set_cp_offset(int cp_offset) { cp_offset_ = cp_offset; } + }; + + class DeferredSetRegister : public DeferredAction { + public: + DeferredSetRegister(int reg, int value) + : DeferredAction(ActionNode::SET_REGISTER, reg), + value_(value) { } + int value() { return value_; } + private: + int value_; + }; + + class DeferredClearCaptures : public DeferredAction { + public: + explicit DeferredClearCaptures(Interval range) + : DeferredAction(ActionNode::CLEAR_CAPTURES, -1), + range_(range) { } + Interval range() { return range_; } + private: + Interval range_; + }; + + class DeferredIncrementRegister : public DeferredAction { + public: + explicit DeferredIncrementRegister(int reg) + : DeferredAction(ActionNode::INCREMENT_REGISTER, reg) { } + }; + + Trace() + : cp_offset_(0), + actions_(NULL), + backtrack_(NULL), + stop_node_(NULL), + loop_label_(NULL), + characters_preloaded_(0), + bound_checked_up_to_(0), + flush_budget_(100), + at_start_(UNKNOWN) { } + + // End the trace. This involves flushing the deferred actions in the trace + // and pushing a backtrack location onto the backtrack stack. Once this is + // done we can start a new trace or go to one that has already been + // generated. + void Flush(RegExpCompiler* compiler, RegExpNode* successor); + int cp_offset() { return cp_offset_; } + DeferredAction* actions() { return actions_; } + // A trivial trace is one that has no deferred actions or other state that + // affects the assumptions used when generating code. There is no recorded + // backtrack location in a trivial trace, so with a trivial trace we will + // generate code that, on a failure to match, gets the backtrack location + // from the backtrack stack rather than using a direct jump instruction. We + // always start code generation with a trivial trace and non-trivial traces + // are created as we emit code for nodes or add to the list of deferred + // actions in the trace. The location of the code generated for a node using + // a trivial trace is recorded in a label in the node so that gotos can be + // generated to that code. + bool is_trivial() { + return backtrack_ == NULL && + actions_ == NULL && + cp_offset_ == 0 && + characters_preloaded_ == 0 && + bound_checked_up_to_ == 0 && + quick_check_performed_.characters() == 0 && + at_start_ == UNKNOWN; + } + TriBool at_start() { return at_start_; } + void set_at_start(bool at_start) { at_start_ = at_start ? TRUE : FALSE; } + Label* backtrack() { return backtrack_; } + Label* loop_label() { return loop_label_; } + RegExpNode* stop_node() { return stop_node_; } + int characters_preloaded() { return characters_preloaded_; } + int bound_checked_up_to() { return bound_checked_up_to_; } + int flush_budget() { return flush_budget_; } + QuickCheckDetails* quick_check_performed() { return &quick_check_performed_; } + bool mentions_reg(int reg); + // Returns true if a deferred position store exists to the specified + // register and stores the offset in the out-parameter. Otherwise + // returns false. + bool GetStoredPosition(int reg, int* cp_offset); + // These set methods and AdvanceCurrentPositionInTrace should be used only on + // new traces - the intention is that traces are immutable after creation. + void add_action(DeferredAction* new_action) { + ASSERT(new_action->next_ == NULL); + new_action->next_ = actions_; + actions_ = new_action; + } + void set_backtrack(Label* backtrack) { backtrack_ = backtrack; } + void set_stop_node(RegExpNode* node) { stop_node_ = node; } + void set_loop_label(Label* label) { loop_label_ = label; } + void set_characters_preloaded(int cpre) { characters_preloaded_ = cpre; } + void set_bound_checked_up_to(int to) { bound_checked_up_to_ = to; } + void set_flush_budget(int to) { flush_budget_ = to; } + void set_quick_check_performed(QuickCheckDetails* d) { + quick_check_performed_ = *d; + } + void InvalidateCurrentCharacter(); + void AdvanceCurrentPositionInTrace(int by, RegExpCompiler* compiler); + private: + int FindAffectedRegisters(OutSet* affected_registers); + void PerformDeferredActions(RegExpMacroAssembler* macro, + int max_register, + OutSet& affected_registers, + OutSet* registers_to_pop, + OutSet* registers_to_clear); + void RestoreAffectedRegisters(RegExpMacroAssembler* macro, + int max_register, + OutSet& registers_to_pop, + OutSet& registers_to_clear); + int cp_offset_; + DeferredAction* actions_; + Label* backtrack_; + RegExpNode* stop_node_; + Label* loop_label_; + int characters_preloaded_; + int bound_checked_up_to_; + QuickCheckDetails quick_check_performed_; + int flush_budget_; + TriBool at_start_; +}; + + +class NodeVisitor { + public: + virtual ~NodeVisitor() { } +#define DECLARE_VISIT(Type) \ + virtual void Visit##Type(Type##Node* that) = 0; +FOR_EACH_NODE_TYPE(DECLARE_VISIT) +#undef DECLARE_VISIT + virtual void VisitLoopChoice(LoopChoiceNode* that) { VisitChoice(that); } +}; + + +// Node visitor used to add the start set of the alternatives to the +// dispatch table of a choice node. +class DispatchTableConstructor: public NodeVisitor { + public: + DispatchTableConstructor(DispatchTable* table, bool ignore_case) + : table_(table), + choice_index_(-1), + ignore_case_(ignore_case) { } + + void BuildTable(ChoiceNode* node); + + void AddRange(CharacterRange range) { + table()->AddRange(range, choice_index_); + } + + void AddInverse(ZoneList<CharacterRange>* ranges); + +#define DECLARE_VISIT(Type) \ + virtual void Visit##Type(Type##Node* that); +FOR_EACH_NODE_TYPE(DECLARE_VISIT) +#undef DECLARE_VISIT + + DispatchTable* table() { return table_; } + void set_choice_index(int value) { choice_index_ = value; } + + protected: + DispatchTable* table_; + int choice_index_; + bool ignore_case_; +}; + + +// Assertion propagation moves information about assertions such as +// \b to the affected nodes. For instance, in /.\b./ information must +// be propagated to the first '.' that whatever follows needs to know +// if it matched a word or a non-word, and to the second '.' that it +// has to check if it succeeds a word or non-word. In this case the +// result will be something like: +// +// +-------+ +------------+ +// | . | | . | +// +-------+ ---> +------------+ +// | word? | | check word | +// +-------+ +------------+ +class Analysis: public NodeVisitor { + public: + explicit Analysis(bool ignore_case) + : ignore_case_(ignore_case), error_message_(NULL) { } + void EnsureAnalyzed(RegExpNode* node); + +#define DECLARE_VISIT(Type) \ + virtual void Visit##Type(Type##Node* that); +FOR_EACH_NODE_TYPE(DECLARE_VISIT) +#undef DECLARE_VISIT + virtual void VisitLoopChoice(LoopChoiceNode* that); + + bool has_failed() { return error_message_ != NULL; } + const char* error_message() { + ASSERT(error_message_ != NULL); + return error_message_; + } + void fail(const char* error_message) { + error_message_ = error_message; + } + private: + bool ignore_case_; + const char* error_message_; + + DISALLOW_IMPLICIT_CONSTRUCTORS(Analysis); +}; + + +struct RegExpCompileData { + RegExpCompileData() + : tree(NULL), + node(NULL), + simple(true), + contains_anchor(false), + capture_count(0) { } + RegExpTree* tree; + RegExpNode* node; + bool simple; + bool contains_anchor; + Handle<String> error; + int capture_count; +}; + + +class RegExpEngine: public AllStatic { + public: + struct CompilationResult { + explicit CompilationResult(const char* error_message) + : error_message(error_message), + code(Heap::the_hole_value()), + num_registers(0) {} + CompilationResult(Object* code, int registers) + : error_message(NULL), + code(code), + num_registers(registers) {} + const char* error_message; + Object* code; + int num_registers; + }; + + static CompilationResult Compile(RegExpCompileData* input, + bool ignore_case, + bool multiline, + Handle<String> pattern, + bool is_ascii); + + static void DotPrint(const char* label, RegExpNode* node, bool ignore_case); +}; + + +} } // namespace v8::internal + +#endif // V8_JSREGEXP_H_ |