Experimental: periodic merge of the bleeding_edge branch to the...

src/jsregexp.h

 // 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
@@ skipping 392 matching lines @@
   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)                                                  \
@@ skipping 157 matching lines @@
   uint32_t value_;
 };
 
 
 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.
-  // Until the implementation is complete we will return true for success and
-  // false for failure.
-  virtual bool Emit(RegExpCompiler* compiler, Trace* trace) = 0;
+  virtual void Emit(RegExpCompiler* compiler, Trace* trace) = 0;
   // How many characters must this node consume at a minimum in order to
-  // succeed.
-  virtual int EatsAtLeast(int recursion_depth) = 0;
+  // 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) = 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;
 
-  // Propagates the given interest information forward.  When seeing
-  // \bfoo for instance, the \b is implemented by propagating forward
-  // to the 'foo' string that it should only succeed if its first
-  // character is a letter xor the previous character was a letter.
-  virtual RegExpNode* PropagateForward(NodeInfo* info) = 0;
-
   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, FAIL, CONTINUE };
+  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 useable state.
+  // 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
@@ skipping 46 matching lines @@
     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, 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 bool Emit(RegExpCompiler* compiler, Trace* trace);
-  virtual int EatsAtLeast(int recursion_depth);
+  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) {
     return on_success()->GetQuickCheckDetails(details, compiler, filled_in);
   }
-  virtual RegExpNode* PropagateForward(NodeInfo* info);
   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;
@@ skipping 12 matching lines @@
            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 RegExpNode* PropagateForward(NodeInfo* info);
-  virtual bool Emit(RegExpCompiler* compiler, Trace* trace);
-  virtual int EatsAtLeast(int recursion_depth);
+  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);
   ZoneList<TextElement>* elements() { return elms_; }
   void MakeCaseIndependent();
   virtual int GreedyLoopTextLength();
   virtual TextNode* Clone() {
     TextNode* result = new TextNode(*this);
     result->CalculateOffsets();
     return result;
@@ skipping 11 matching lines @@
                     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) {
+    return on_success()->GetQuickCheckDetails(details, compiler, filled_in);
+  }
+  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 bool Emit(RegExpCompiler* compiler, Trace* trace);
-  virtual int EatsAtLeast(int recursion_depth) { return 0; }
+  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) {
     return;
   }
-  virtual RegExpNode* PropagateForward(NodeInfo* info);
   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 bool Emit(RegExpCompiler* compiler, Trace* trace);
-  virtual int EatsAtLeast(int recursion_depth) { return 0; }
+  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) {
     // Returning 0 from EatsAtLeast should ensure we never get here.
     UNREACHABLE();
   }
-  virtual RegExpNode* PropagateForward(NodeInfo* info);
   virtual EndNode* Clone() { return new EndNode(*this); }
 
- protected:
-  void EmitInfoChecks(RegExpMacroAssembler* macro, Trace* trace);
-
  private:
   Action action_;
 };
 
 
 class NegativeSubmatchSuccess: public EndNode {
  public:
-  NegativeSubmatchSuccess(int stack_pointer_reg, int position_reg)
+  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) { }
-  virtual bool Emit(RegExpCompiler* compiler, Trace* trace);
+        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) { }
@@ skipping 28 matching lines @@
 class ChoiceNode: public RegExpNode {
  public:
   explicit ChoiceNode(int expected_size)
       : alternatives_(new ZoneList<GuardedAlternative>(expected_size)),
         table_(NULL),
         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 bool Emit(RegExpCompiler* compiler, Trace* trace);
-  virtual int EatsAtLeast(int recursion_depth);
-  int EatsAtLeastHelper(int recursion_depth, RegExpNode* ignore_this_node);
+  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);
-  virtual RegExpNode* PropagateForward(NodeInfo* info);
   virtual ChoiceNode* Clone() { return new ChoiceNode(*this); }
 
   bool being_calculated() { return being_calculated_; }
   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);
-  bool EmitOutOfLineContinuation(RegExpCompiler* compiler,
+  void EmitOutOfLineContinuation(RegExpCompiler* compiler,
                                  Trace* trace,
                                  GuardedAlternative alternative,
                                  AlternativeGeneration* alt_gen,
                                  int preload_characters,
                                  bool next_expects_preload);
   DispatchTable* table_;
   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);
+  // 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 bool Emit(RegExpCompiler* compiler, Trace* trace);
-  virtual int EatsAtLeast(int recursion_depth);  // Returns 0.
+  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);
   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:
@@ skipping 31 matching lines @@
     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 {
+  class DeferredCapture : public DeferredAction {
    public:
-    DeferredCapture(int reg, Trace* trace)
+    DeferredCapture(int reg, bool is_capture, Trace* trace)
         : DeferredAction(ActionNode::STORE_POSITION, reg),
-          cp_offset_(trace->cp_offset()) { }
+          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 {
+  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 {
+  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) { }
   // 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.
-  bool Flush(RegExpCompiler* compiler, RegExpNode* successor);
+  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
@@ skipping 26 matching lines @@
     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_quick_check_performed(QuickCheckDetails* d) {
     quick_check_performed_ = *d;
   }
-  void clear_quick_check_performed() {
-  }
-  void AdvanceCurrentPositionInTrace(int by, bool ascii);
+  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& affected_registers,
+                               OutSet* registers_to_pop,
+                               OutSet* registers_to_clear);
   void RestoreAffectedRegisters(RegExpMacroAssembler* macro,
                                 int max_register,
-                                OutSet& affected_registers);
-  void PushAffectedRegisters(RegExpMacroAssembler* macro,
-                             int max_register,
-                             OutSet& affected_registers);
+                                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_;
 };
 
@@ skipping 94 matching lines @@
                                     Handle<String> pattern,
                                     bool is_ascii);
 
   static void DotPrint(const char* label, RegExpNode* node, bool ignore_case);
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_JSREGEXP_H_