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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: set ts=8 sts=4 et sw=4 tw=99: */
+
+// Copyright 2012 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_
+
+#include "jscntxt.h"
+
+#include "ds/SplayTree.h"
+#include "jit/Label.h"
+#include "vm/RegExpObject.h"
+
+namespace js {
+
+class MatchPairs;
+class RegExpShared;
+
+namespace jit {
+ class Label;
+ class JitCode;
+}
+
+namespace irregexp {
+
+class RegExpTree;
+class RegExpMacroAssembler;
+
+struct RegExpCompileData
+{
+ RegExpCompileData()
+ : tree(nullptr),
+ simple(true),
+ contains_anchor(false),
+ capture_count(0)
+ {}
+
+ RegExpTree* tree;
+ bool simple;
+ bool contains_anchor;
+ int capture_count;
+};
+
+struct RegExpCode
+{
+ jit::JitCode* jitCode;
+ uint8_t* byteCode;
+
+ RegExpCode()
+ : jitCode(nullptr), byteCode(nullptr)
+ {}
+
+ bool empty() {
+ return !jitCode && !byteCode;
+ }
+
+ void destroy() {
+ js_free(byteCode);
+ }
+};
+
+RegExpCode
+CompilePattern(JSContext* cx, RegExpShared* shared, RegExpCompileData* data,
+ HandleLinearString sample, bool is_global, bool ignore_case,
+ bool is_ascii, bool match_only, bool force_bytecode, bool sticky,
+ bool unicode);
+
+// Note: this may return RegExpRunStatus_Error if an interrupt was requested
+// while the code was executing.
+template <typename CharT>
+RegExpRunStatus
+ExecuteCode(JSContext* cx, jit::JitCode* codeBlock, const CharT* chars, size_t start,
+ size_t length, MatchPairs* matches, size_t* endIndex);
+
+template <typename CharT>
+RegExpRunStatus
+InterpretCode(JSContext* cx, const uint8_t* byteCode, const CharT* chars, size_t start,
+ size_t length, MatchPairs* matches, size_t* endIndex);
+
+#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
+
+// InfallibleVector is like Vector, but all its methods are infallible (they
+// crash on OOM). We use this class instead of Vector to avoid a ton of
+// MOZ_MUST_USE warnings in irregexp code (imported from V8).
+template<typename T, size_t N>
+class InfallibleVector
+{
+ Vector<T, N, LifoAllocPolicy<Infallible>> vector_;
+
+ InfallibleVector(const InfallibleVector&) = delete;
+ void operator=(const InfallibleVector&) = delete;
+
+ public:
+ explicit InfallibleVector(const LifoAllocPolicy<Infallible>& alloc) : vector_(alloc) {}
+
+ void append(const T& t) { MOZ_ALWAYS_TRUE(vector_.append(t)); }
+ void append(const T* begin, size_t length) { MOZ_ALWAYS_TRUE(vector_.append(begin, length)); }
+
+ void clear() { vector_.clear(); }
+ void popBack() { vector_.popBack(); }
+ void reserve(size_t n) { MOZ_ALWAYS_TRUE(vector_.reserve(n)); }
+
+ size_t length() const { return vector_.length(); }
+ T popCopy() { return vector_.popCopy(); }
+
+ T* begin() { return vector_.begin(); }
+ const T* begin() const { return vector_.begin(); }
+
+ T& operator[](size_t index) { return vector_[index]; }
+ const T& operator[](size_t index) const { return vector_[index]; }
+
+ InfallibleVector& operator=(InfallibleVector&& rhs) { vector_ = Move(rhs.vector_); return *this; }
+};
+
+class CharacterRange;
+typedef InfallibleVector<CharacterRange, 1> CharacterRangeVector;
+
+// Represents code units in the range from from_ to to_, both ends are
+// inclusive.
+class CharacterRange
+{
+ public:
+ CharacterRange()
+ : from_(0), to_(0)
+ {}
+
+ CharacterRange(char16_t from, char16_t to)
+ : from_(from), to_(to)
+ {}
+
+ static void AddClassEscape(LifoAlloc* alloc, char16_t type, CharacterRangeVector* ranges);
+ static void AddClassEscapeUnicode(LifoAlloc* alloc, char16_t type,
+ CharacterRangeVector* ranges, bool ignoreCase);
+
+ static inline CharacterRange Singleton(char16_t value) {
+ return CharacterRange(value, value);
+ }
+ static inline CharacterRange Range(char16_t from, char16_t to) {
+ MOZ_ASSERT(from <= to);
+ return CharacterRange(from, to);
+ }
+ static inline CharacterRange Everything() {
+ return CharacterRange(0, 0xFFFF);
+ }
+ bool Contains(char16_t i) { return from_ <= i && i <= to_; }
+ char16_t from() const { return from_; }
+ void set_from(char16_t value) { from_ = value; }
+ char16_t to() const { return to_; }
+ void set_to(char16_t value) { to_ = value; }
+ bool is_valid() { return from_ <= to_; }
+ bool IsEverything(char16_t max) { return from_ == 0 && to_ >= max; }
+ bool IsSingleton() { return (from_ == to_); }
+ void AddCaseEquivalents(bool is_ascii, bool unicode, CharacterRangeVector* ranges);
+
+ static void Split(const LifoAlloc* alloc,
+ CharacterRangeVector base,
+ const Vector<int>& overlay,
+ CharacterRangeVector* included,
+ CharacterRangeVector* excluded);
+
+ // Whether a range list is in canonical form: Ranges ordered by from value,
+ // and ranges non-overlapping and non-adjacent.
+ static bool IsCanonical(const CharacterRangeVector& ranges);
+
+ // Convert range list to canonical form. The characters covered by the ranges
+ // will still be the same, but no character is in more than one range, and
+ // adjacent ranges are merged. The resulting list may be shorter than the
+ // original, but cannot be longer.
+ static void Canonicalize(CharacterRangeVector& ranges);
+
+ // Negate the contents of a character range in canonical form.
+ static void Negate(const LifoAlloc* alloc,
+ CharacterRangeVector src,
+ CharacterRangeVector* dst);
+
+ static const int kStartMarker = (1 << 24);
+ static const int kPayloadMask = (1 << 24) - 1;
+
+ private:
+ char16_t from_;
+ char16_t to_;
+};
+
+// A set of unsigned integers that behaves especially well on small
+// integers (< 32).
+class OutSet
+{
+ public:
+ OutSet()
+ : first_(0), remaining_(nullptr), successors_(nullptr)
+ {}
+
+ OutSet* Extend(LifoAlloc* alloc, unsigned value);
+ bool Get(unsigned value);
+ static const unsigned kFirstLimit = 32;
+
+ private:
+ typedef InfallibleVector<OutSet*, 1> OutSetVector;
+ typedef InfallibleVector<unsigned, 1> RemainingVector;
+
+ // 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(LifoAlloc* alloc, 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.
+ OutSetVector* successors() { return successors_; }
+
+ OutSet(uint32_t first, RemainingVector* remaining)
+ : first_(first), remaining_(remaining), successors_(nullptr)
+ {}
+
+ RemainingVector& remaining() { return *remaining_; }
+
+ uint32_t first_;
+ RemainingVector* remaining_;
+ OutSetVector* 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:
+ explicit DispatchTable(LifoAlloc* alloc)
+ {}
+
+ class Entry {
+ public:
+ Entry()
+ : from_(0), to_(0), out_set_(nullptr)
+ {}
+
+ Entry(char16_t from, char16_t to, OutSet* out_set)
+ : from_(from), to_(to), out_set_(out_set)
+ {}
+
+ char16_t from() { return from_; }
+ char16_t to() { return to_; }
+ void set_to(char16_t value) { to_ = value; }
+ void AddValue(LifoAlloc* alloc, int value) {
+ out_set_ = out_set_->Extend(alloc, value);
+ }
+ OutSet* out_set() { return out_set_; }
+ private:
+ char16_t from_;
+ char16_t to_;
+ OutSet* out_set_;
+ };
+
+ void AddRange(LifoAlloc* alloc, CharacterRange range, int value);
+ OutSet* Get(char16_t value);
+ void Dump();
+
+ private:
+ // There can't be a static empty set since it allocates its
+ // successors in a LifoAlloc and caches them.
+ OutSet* empty() { return &empty_; }
+ OutSet empty_;
+};
+
+class TextElement
+{
+ public:
+ enum TextType {
+ ATOM,
+ CHAR_CLASS
+ };
+
+ static TextElement Atom(RegExpAtom* atom);
+ static TextElement CharClass(RegExpCharacterClass* char_class);
+
+ int cp_offset() const { return cp_offset_; }
+ void set_cp_offset(int cp_offset) { cp_offset_ = cp_offset; }
+ int length() const;
+
+ TextType text_type() const { return text_type_; }
+
+ RegExpTree* tree() const { return tree_; }
+
+ RegExpAtom* atom() const {
+ MOZ_ASSERT(text_type() == ATOM);
+ return reinterpret_cast<RegExpAtom*>(tree());
+ }
+
+ RegExpCharacterClass* char_class() const {
+ MOZ_ASSERT(text_type() == CHAR_CLASS);
+ return reinterpret_cast<RegExpCharacterClass*>(tree());
+ }
+
+ private:
+ TextElement(TextType text_type, RegExpTree* tree)
+ : cp_offset_(-1), text_type_(text_type), tree_(tree)
+ {}
+
+ int cp_offset_;
+ TextType text_type_;
+ RegExpTree* tree_;
+};
+
+typedef InfallibleVector<TextElement, 1> TextElementVector;
+
+class NodeVisitor;
+class RegExpCompiler;
+class Trace;
+class BoyerMooreLookahead;
+
+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),
+ replacement_calculated(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;
+ bool replacement_calculated: 1;
+};
+
+// 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; }
+
+ int characters() { return characters_; }
+ void set_characters(int characters) { characters_ = characters; }
+
+ struct Position {
+ Position() : mask(0), value(0), determines_perfectly(false) { }
+ char16_t mask;
+ char16_t value;
+ bool determines_perfectly;
+ };
+
+ Position* positions(int index) {
+ MOZ_ASSERT(index >= 0);
+ MOZ_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:
+ explicit RegExpNode(LifoAlloc* alloc);
+ 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. The not_at_start argument is
+ // used to indicate that we know we are not at the start of the input. In
+ // this case anchored branches will always fail and can be ignored when
+ // determining how many characters are consumed on success.
+ virtual int EatsAtLeast(int still_to_find, int budget, bool not_at_start) = 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,
+ jit::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; }
+
+ // Only returns the successor for a text node of length 1 that matches any
+ // character and that has no guards on it.
+ virtual RegExpNode* GetSuccessorOfOmnivorousTextNode(RegExpCompiler* compiler) {
+ return nullptr;
+ }
+
+ static const int kRecursionBudget = 200;
+
+ // Collects information on the possible code units (mod 128) that can match if
+ // we look forward. This is used for a Boyer-Moore-like string searching
+ // implementation. TODO(erikcorry): This should share more code with
+ // EatsAtLeast, GetQuickCheckDetails. The budget argument is used to limit
+ // the number of nodes we are willing to look at in order to create this data.
+ virtual bool FillInBMInfo(int offset,
+ int budget,
+ BoyerMooreLookahead* bm,
+ bool not_at_start) {
+ MOZ_CRASH("Bad call");
+ }
+
+ // If we know that the input is ASCII then there are some nodes that can
+ // never match. This method returns a node that can be substituted for
+ // itself, or nullptr if the node can never match.
+ virtual RegExpNode* FilterASCII(int depth, bool ignore_case, bool unicode) { return this; }
+
+ // Helper for FilterASCII.
+ RegExpNode* replacement() {
+ MOZ_ASSERT(info()->replacement_calculated);
+ return replacement_;
+ }
+ RegExpNode* set_replacement(RegExpNode* replacement) {
+ info()->replacement_calculated = true;
+ replacement_ = replacement;
+ return replacement; // For convenience.
+ }
+
+ // We want to avoid recalculating the lookahead info, so we store it on the
+ // node. Only info that is for this node is stored. We can tell that the
+ // info is for this node when offset == 0, so the information is calculated
+ // relative to this node.
+ void SaveBMInfo(BoyerMooreLookahead* bm, bool not_at_start, int offset) {
+ if (offset == 0) set_bm_info(not_at_start, bm);
+ }
+
+ jit::Label* label() { return &label_; }
+
+ // If non-generic code is generated for a node (i.e. 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_; }
+
+ BoyerMooreLookahead* bm_info(bool not_at_start) {
+ return bm_info_[not_at_start ? 1 : 0];
+ }
+
+ LifoAlloc* alloc() const { return alloc_; }
+
+ protected:
+ enum LimitResult { DONE, CONTINUE };
+ RegExpNode* replacement_;
+
+ LimitResult LimitVersions(RegExpCompiler* compiler, Trace* trace);
+
+ void set_bm_info(bool not_at_start, BoyerMooreLookahead* bm) {
+ bm_info_[not_at_start ? 1 : 0] = bm;
+ }
+
+ private:
+ static const int kFirstCharBudget = 10;
+ jit::Label label_;
+ NodeInfo info_;
+
+ // 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_;
+ BoyerMooreLookahead* bm_info_[2];
+
+ LifoAlloc* alloc_;
+};
+
+// 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() const { return from_; }
+ int to() const { 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)
+ : RegExpNode(on_success->alloc()), on_success_(on_success)
+ {}
+
+ RegExpNode* on_success() { return on_success_; }
+ void set_on_success(RegExpNode* node) { on_success_ = node; }
+ virtual RegExpNode* FilterASCII(int depth, bool ignore_case, bool unicode);
+ virtual bool FillInBMInfo(int offset,
+ int budget,
+ BoyerMooreLookahead* bm,
+ bool not_at_start);
+
+ protected:
+ RegExpNode* FilterSuccessor(int depth, bool ignore_case, bool unicode);
+
+ private:
+ RegExpNode* on_success_;
+};
+
+class ActionNode : public SeqRegExpNode
+{
+ public:
+ enum ActionType {
+ SET_REGISTER,
+ INCREMENT_REGISTER,
+ STORE_POSITION,
+ BEGIN_SUBMATCH,
+ POSITIVE_SUBMATCH_SUCCESS,
+ EMPTY_MATCH_CHECK,
+ CLEAR_CAPTURES
+ };
+
+ ActionNode(ActionType action_type, RegExpNode* on_success)
+ : SeqRegExpNode(on_success),
+ action_type_(action_type)
+ {}
+
+ 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 budget, bool not_at_start);
+ 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);
+ }
+ virtual bool FillInBMInfo(int offset,
+ int budget,
+ BoyerMooreLookahead* bm,
+ bool not_at_start);
+ ActionType action_type() { return action_type_; }
+ // TODO(erikcorry): We should allow some action nodes in greedy loops.
+ virtual int GreedyLoopTextLength() { return kNodeIsTooComplexForGreedyLoops; }
+
+ 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_;
+ ActionType action_type_;
+ friend class DotPrinter;
+};
+
+class TextNode : public SeqRegExpNode
+{
+ public:
+ TextNode(TextElementVector* elements,
+ RegExpNode* on_success)
+ : SeqRegExpNode(on_success),
+ elements_(elements)
+ {}
+
+ TextNode(RegExpCharacterClass* that,
+ RegExpNode* on_success)
+ : SeqRegExpNode(on_success),
+ elements_(alloc()->newInfallible<TextElementVector>(*alloc()))
+ {
+ elements_->append(TextElement::CharClass(that));
+ }
+
+ virtual void Accept(NodeVisitor* visitor);
+ virtual void Emit(RegExpCompiler* compiler, Trace* trace);
+ virtual int EatsAtLeast(int still_to_find, int budget, bool not_at_start);
+ virtual void GetQuickCheckDetails(QuickCheckDetails* details,
+ RegExpCompiler* compiler,
+ int characters_filled_in,
+ bool not_at_start);
+ TextElementVector& elements() { return *elements_; }
+ void MakeCaseIndependent(bool is_ascii, bool unicode);
+ virtual int GreedyLoopTextLength();
+ virtual RegExpNode* GetSuccessorOfOmnivorousTextNode(
+ RegExpCompiler* compiler);
+ virtual bool FillInBMInfo(int offset,
+ int budget,
+ BoyerMooreLookahead* bm,
+ bool not_at_start);
+ void CalculateOffsets();
+ virtual RegExpNode* FilterASCII(int depth, bool ignore_case, bool unicode);
+
+ 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();
+ TextElementVector* elements_;
+};
+
+class AssertionNode : public SeqRegExpNode
+{
+ public:
+ enum AssertionType {
+ AT_END,
+ AT_START,
+ AT_BOUNDARY,
+ AT_NON_BOUNDARY,
+ AFTER_NEWLINE,
+ NOT_AFTER_LEAD_SURROGATE,
+ NOT_IN_SURROGATE_PAIR
+ };
+ AssertionNode(AssertionType t, RegExpNode* on_success)
+ : SeqRegExpNode(on_success), assertion_type_(t)
+ {}
+
+ static AssertionNode* AtEnd(RegExpNode* on_success) {
+ return on_success->alloc()->newInfallible<AssertionNode>(AT_END, on_success);
+ }
+ static AssertionNode* AtStart(RegExpNode* on_success) {
+ return on_success->alloc()->newInfallible<AssertionNode>(AT_START, on_success);
+ }
+ static AssertionNode* AtBoundary(RegExpNode* on_success) {
+ return on_success->alloc()->newInfallible<AssertionNode>(AT_BOUNDARY, on_success);
+ }
+ static AssertionNode* AtNonBoundary(RegExpNode* on_success) {
+ return on_success->alloc()->newInfallible<AssertionNode>(AT_NON_BOUNDARY, on_success);
+ }
+ static AssertionNode* AfterNewline(RegExpNode* on_success) {
+ return on_success->alloc()->newInfallible<AssertionNode>(AFTER_NEWLINE, on_success);
+ }
+ static AssertionNode* NotAfterLeadSurrogate(RegExpNode* on_success) {
+ return on_success->alloc()->newInfallible<AssertionNode>(NOT_AFTER_LEAD_SURROGATE,
+ on_success);
+ }
+ static AssertionNode* NotInSurrogatePair(RegExpNode* on_success) {
+ return on_success->alloc()->newInfallible<AssertionNode>(NOT_IN_SURROGATE_PAIR,
+ on_success);
+ }
+ virtual void Accept(NodeVisitor* visitor);
+ virtual void Emit(RegExpCompiler* compiler, Trace* trace);
+ virtual int EatsAtLeast(int still_to_find, int budget, bool not_at_start);
+ virtual void GetQuickCheckDetails(QuickCheckDetails* details,
+ RegExpCompiler* compiler,
+ int filled_in,
+ bool not_at_start);
+ virtual bool FillInBMInfo(int offset,
+ int budget,
+ BoyerMooreLookahead* bm,
+ bool not_at_start);
+ AssertionType assertion_type() { return assertion_type_; }
+
+ private:
+ void EmitBoundaryCheck(RegExpCompiler* compiler, Trace* trace);
+ enum IfPrevious { kIsNonWord, kIsWord };
+ void BacktrackIfPrevious(RegExpCompiler* compiler,
+ Trace* trace,
+ IfPrevious backtrack_if_previous);
+ AssertionType assertion_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,
+ bool not_at_start);
+ virtual void GetQuickCheckDetails(QuickCheckDetails* details,
+ RegExpCompiler* compiler,
+ int characters_filled_in,
+ bool not_at_start) {
+ return;
+ }
+ virtual bool FillInBMInfo(int offset,
+ int budget,
+ BoyerMooreLookahead* bm,
+ bool not_at_start);
+
+ private:
+ int start_reg_;
+ int end_reg_;
+};
+
+class EndNode : public RegExpNode
+{
+ public:
+ enum Action { ACCEPT, BACKTRACK, NEGATIVE_SUBMATCH_SUCCESS };
+
+ explicit EndNode(LifoAlloc* alloc, Action action)
+ : RegExpNode(alloc), action_(action)
+ {}
+
+ virtual void Accept(NodeVisitor* visitor);
+ virtual void Emit(RegExpCompiler* compiler, Trace* trace);
+ virtual int EatsAtLeast(int still_to_find,
+ int recursion_depth,
+ bool not_at_start) { 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.
+ MOZ_CRASH("Bad call");
+ }
+ virtual bool FillInBMInfo(int offset,
+ int budget,
+ BoyerMooreLookahead* bm,
+ bool not_at_start) {
+ // Returning 0 from EatsAtLeast should ensure we never get here.
+ MOZ_CRASH("Bad call");
+ }
+
+ private:
+ Action action_;
+};
+
+class NegativeSubmatchSuccess : public EndNode
+{
+ public:
+ NegativeSubmatchSuccess(LifoAlloc* alloc,
+ int stack_pointer_reg,
+ int position_reg,
+ int clear_capture_count,
+ int clear_capture_start)
+ : EndNode(alloc, 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:
+ 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_;
+};
+
+typedef InfallibleVector<Guard*, 1> GuardVector;
+
+class GuardedAlternative
+{
+ public:
+ explicit GuardedAlternative(RegExpNode* node)
+ : node_(node), guards_(nullptr)
+ {}
+
+ void AddGuard(LifoAlloc* alloc, Guard* guard);
+ RegExpNode* node() const { return node_; }
+ void set_node(RegExpNode* node) { node_ = node; }
+ const GuardVector* guards() const { return guards_; }
+
+ private:
+ RegExpNode* node_;
+ GuardVector* guards_;
+};
+
+typedef InfallibleVector<GuardedAlternative, 0> GuardedAlternativeVector;
+
+class AlternativeGeneration;
+
+class ChoiceNode : public RegExpNode
+{
+ public:
+ explicit ChoiceNode(LifoAlloc* alloc, int expected_size)
+ : RegExpNode(alloc),
+ alternatives_(*alloc),
+ table_(nullptr),
+ not_at_start_(false),
+ being_calculated_(false)
+ {
+ alternatives_.reserve(expected_size);
+ }
+
+ virtual void Accept(NodeVisitor* visitor);
+ void AddAlternative(GuardedAlternative node) {
+ alternatives_.append(node);
+ }
+
+ GuardedAlternativeVector& alternatives() { return alternatives_; }
+ DispatchTable* GetTable(bool ignore_case);
+ virtual void Emit(RegExpCompiler* compiler, Trace* trace);
+ virtual int EatsAtLeast(int still_to_find, int budget, bool not_at_start);
+ int EatsAtLeastHelper(int still_to_find,
+ int budget,
+ RegExpNode* ignore_this_node,
+ bool not_at_start);
+ virtual void GetQuickCheckDetails(QuickCheckDetails* details,
+ RegExpCompiler* compiler,
+ int characters_filled_in,
+ bool not_at_start);
+ virtual bool FillInBMInfo(int offset,
+ int budget,
+ BoyerMooreLookahead* bm,
+ bool not_at_start);
+
+ 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; }
+ virtual RegExpNode* FilterASCII(int depth, bool ignore_case, bool unicode);
+
+ protected:
+ int GreedyLoopTextLengthForAlternative(GuardedAlternative* alternative);
+ GuardedAlternativeVector alternatives_;
+
+ private:
+ friend class Analysis;
+ void GenerateGuard(RegExpMacroAssembler* macro_assembler,
+ Guard* guard,
+ Trace* trace);
+ int CalculatePreloadCharacters(RegExpCompiler* compiler, int eats_at_least);
+ 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(LifoAlloc* alloc,
+ GuardedAlternative this_must_fail,
+ GuardedAlternative then_do_this)
+ : ChoiceNode(alloc, 2)
+ {
+ AddAlternative(this_must_fail);
+ AddAlternative(then_do_this);
+ }
+ virtual int EatsAtLeast(int still_to_find, int budget, bool not_at_start);
+ virtual void GetQuickCheckDetails(QuickCheckDetails* details,
+ RegExpCompiler* compiler,
+ int characters_filled_in,
+ bool not_at_start);
+ virtual bool FillInBMInfo(int offset,
+ int budget,
+ BoyerMooreLookahead* bm,
+ 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; }
+ virtual RegExpNode* FilterASCII(int depth, bool ignore_case, bool unicode);
+};
+
+class LoopChoiceNode : public ChoiceNode
+{
+ public:
+ explicit LoopChoiceNode(LifoAlloc* alloc, bool body_can_be_zero_length)
+ : ChoiceNode(alloc, 2),
+ loop_node_(nullptr),
+ continue_node_(nullptr),
+ 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 budget, bool not_at_start);
+ virtual void GetQuickCheckDetails(QuickCheckDetails* details,
+ RegExpCompiler* compiler,
+ int characters_filled_in,
+ bool not_at_start);
+ virtual bool FillInBMInfo(int offset,
+ int budget,
+ BoyerMooreLookahead* bm,
+ bool not_at_start);
+ 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);
+ virtual RegExpNode* FilterASCII(int depth, bool ignore_case, bool unicode);
+
+ 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_;
+};
+
+// Improve the speed that we scan for an initial point where a non-anchored
+// regexp can match by using a Boyer-Moore-like table. This is done by
+// identifying non-greedy non-capturing loops in the nodes that eat any
+// character one at a time. For example in the middle of the regexp
+// /foo[\s\S]*?bar/ we find such a loop. There is also such a loop implicitly
+// inserted at the start of any non-anchored regexp.
+//
+// When we have found such a loop we look ahead in the nodes to find the set of
+// characters that can come at given distances. For example for the regexp
+// /.?foo/ we know that there are at least 3 characters ahead of us, and the
+// sets of characters that can occur are [any, [f, o], [o]]. We find a range in
+// the lookahead info where the set of characters is reasonably constrained. In
+// our example this is from index 1 to 2 (0 is not constrained). We can now
+// look 3 characters ahead and if we don't find one of [f, o] (the union of
+// [f, o] and [o]) then we can skip forwards by the range size (in this case 2).
+//
+// For Unicode input strings we do the same, but modulo 128.
+//
+// We also look at the first string fed to the regexp and use that to get a hint
+// of the character frequencies in the inputs. This affects the assessment of
+// whether the set of characters is 'reasonably constrained'.
+//
+// We also have another lookahead mechanism (called quick check in the code),
+// which uses a wide load of multiple characters followed by a mask and compare
+// to determine whether a match is possible at this point.
+enum ContainedInLattice {
+ kNotYet = 0,
+ kLatticeIn = 1,
+ kLatticeOut = 2,
+ kLatticeUnknown = 3 // Can also mean both in and out.
+};
+
+inline ContainedInLattice
+Combine(ContainedInLattice a, ContainedInLattice b) {
+ return static_cast<ContainedInLattice>(a | b);
+}
+
+ContainedInLattice
+AddRange(ContainedInLattice a,
+ const int* ranges,
+ int ranges_size,
+ Interval new_range);
+
+class BoyerMoorePositionInfo
+{
+ public:
+ explicit BoyerMoorePositionInfo(LifoAlloc* alloc)
+ : map_(*alloc),
+ map_count_(0),
+ w_(kNotYet),
+ s_(kNotYet),
+ d_(kNotYet),
+ surrogate_(kNotYet)
+ {
+ map_.reserve(kMapSize);
+ for (int i = 0; i < kMapSize; i++)
+ map_.append(false);
+ }
+
+ bool& at(int i) { return map_[i]; }
+
+ static const int kMapSize = 128;
+ static const int kMask = kMapSize - 1;
+
+ int map_count() const { return map_count_; }
+
+ void Set(int character);
+ void SetInterval(const Interval& interval);
+ void SetAll();
+ bool is_non_word() { return w_ == kLatticeOut; }
+ bool is_word() { return w_ == kLatticeIn; }
+
+ private:
+ InfallibleVector<bool, 0> map_;
+ int map_count_; // Number of set bits in the map.
+ ContainedInLattice w_; // The \w character class.
+ ContainedInLattice s_; // The \s character class.
+ ContainedInLattice d_; // The \d character class.
+ ContainedInLattice surrogate_; // Surrogate UTF-16 code units.
+};
+
+typedef InfallibleVector<BoyerMoorePositionInfo*, 1> BoyerMoorePositionInfoVector;
+
+class BoyerMooreLookahead
+{
+ public:
+ BoyerMooreLookahead(LifoAlloc* alloc, size_t length, RegExpCompiler* compiler);
+
+ int length() { return length_; }
+ int max_char() { return max_char_; }
+ RegExpCompiler* compiler() { return compiler_; }
+
+ int Count(int map_number) {
+ return bitmaps_[map_number]->map_count();
+ }
+
+ BoyerMoorePositionInfo* at(int i) { return bitmaps_[i]; }
+
+ void Set(int map_number, int character) {
+ if (character > max_char_) return;
+ BoyerMoorePositionInfo* info = bitmaps_[map_number];
+ info->Set(character);
+ }
+
+ void SetInterval(int map_number, const Interval& interval) {
+ if (interval.from() > max_char_) return;
+ BoyerMoorePositionInfo* info = bitmaps_[map_number];
+ if (interval.to() > max_char_) {
+ info->SetInterval(Interval(interval.from(), max_char_));
+ } else {
+ info->SetInterval(interval);
+ }
+ }
+
+ void SetAll(int map_number) {
+ bitmaps_[map_number]->SetAll();
+ }
+
+ void SetRest(int from_map) {
+ for (int i = from_map; i < length_; i++) SetAll(i);
+ }
+ bool EmitSkipInstructions(RegExpMacroAssembler* masm);
+
+ bool CheckOverRecursed();
+
+ private:
+ // This is the value obtained by EatsAtLeast. If we do not have at least this
+ // many characters left in the sample string then the match is bound to fail.
+ // Therefore it is OK to read a character this far ahead of the current match
+ // point.
+ int length_;
+ RegExpCompiler* compiler_;
+
+ // 0x7f for ASCII, 0xffff for UTF-16.
+ int max_char_;
+ BoyerMoorePositionInfoVector bitmaps_;
+
+ int GetSkipTable(int min_lookahead,
+ int max_lookahead,
+ uint8_t* boolean_skip_table);
+ bool FindWorthwhileInterval(int* from, int* to);
+ int FindBestInterval(int max_number_of_chars, int old_biggest_points, int* from, int* to);
+};
+
+// 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_VALUE = 0, TRUE_VALUE = 1
+ };
+
+ class DeferredAction {
+ public:
+ DeferredAction(ActionNode::ActionType action_type, int reg)
+ : action_type_(action_type), reg_(reg), next_(nullptr)
+ {}
+
+ DeferredAction* next() { return next_; }
+ bool Mentions(int reg);
+ int reg() { return reg_; }
+ ActionNode::ActionType action_type() { return action_type_; }
+ private:
+ ActionNode::ActionType action_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_(nullptr),
+ backtrack_(nullptr),
+ stop_node_(nullptr),
+ loop_label_(nullptr),
+ 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_ == nullptr &&
+ actions_ == nullptr &&
+ 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_VALUE : FALSE_VALUE;
+ }
+ jit::Label* backtrack() { return backtrack_; }
+ jit::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) {
+ MOZ_ASSERT(new_action->next_ == nullptr);
+ new_action->next_ = actions_;
+ actions_ = new_action;
+ }
+
+ void set_backtrack(jit::Label* backtrack) { backtrack_ = backtrack; }
+ void set_stop_node(RegExpNode* node) { stop_node_ = node; }
+ void set_loop_label(jit::Label* label) { loop_label_ = label; }
+ void set_characters_preloaded(int count) { characters_preloaded_ = count; }
+ 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(LifoAlloc* alloc, OutSet* affected_registers);
+ void PerformDeferredActions(LifoAlloc* alloc,
+ 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_;
+ jit::Label* backtrack_;
+ RegExpNode* stop_node_;
+ jit::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); }
+};
+
+// 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:
+ Analysis(JSContext* cx, bool ignore_case, bool is_ascii, bool unicode)
+ : cx(cx),
+ ignore_case_(ignore_case),
+ is_ascii_(is_ascii),
+ unicode_(unicode),
+ error_message_(nullptr)
+ {}
+
+ 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_ != nullptr; }
+ const char* errorMessage() {
+ MOZ_ASSERT(error_message_ != nullptr);
+ return error_message_;
+ }
+ void failASCII(const char* error_message) {
+ error_message_ = error_message;
+ }
+
+ private:
+ JSContext* cx;
+ bool ignore_case_;
+ bool is_ascii_;
+ bool unicode_;
+ const char* error_message_;
+
+ Analysis(Analysis&) = delete;
+ void operator=(Analysis&) = delete;
+};
+
+} } // namespace js::irregexp
+
+#endif // V8_JSREGEXP_H_