Remove assertion expansion.

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 442 matching lines @@
 
 
 struct NodeInfo {
   enum TriBool {
     UNKNOWN = -1, FALSE = 0, TRUE = 1
   };
 
   NodeInfo()
       : being_analyzed(false),
         been_analyzed(false),
-        being_expanded(false),
-        been_expanded(false),
-        determine_word(false),
-        determine_newline(false),
-        determine_start(false),
-        does_determine_word(false),
-        does_determine_newline(false),
-        does_determine_start(false),
         follows_word_interest(false),
         follows_newline_interest(false),
         follows_start_interest(false),
-        is_word(UNKNOWN),
-        is_newline(UNKNOWN),
         at_end(false),
-        follows_word(UNKNOWN),
-        follows_newline(UNKNOWN),
-        follows_start(UNKNOWN),
         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) &&
-           (follows_word == that->follows_word) &&
-           (follows_newline == that->follows_newline) &&
-           (follows_start == that->follows_start) &&
-           (does_determine_word == that->does_determine_word) &&
-           (does_determine_newline == that->does_determine_newline) &&
-           (does_determine_start == that->does_determine_start);
-  }
-
-  bool HasAssertions() {
-    return (follows_word != UNKNOWN) ||
-           (follows_newline != UNKNOWN) ||
-           (follows_start != UNKNOWN);
+           (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;
   }
 
-  void AddAssumptions(NodeInfo* that) {
-    if (that->follows_word != UNKNOWN) {
-      ASSERT(follows_word == UNKNOWN || follows_word == that->follows_word);
-      follows_word = that->follows_word;
-    }
-    if (that->follows_newline != UNKNOWN) {
-      ASSERT(follows_newline == UNKNOWN ||
-             follows_newline == that->follows_newline);
-      follows_newline = that->follows_newline;
-    }
-    if (that->follows_start != UNKNOWN) {
-      ASSERT(follows_start == UNKNOWN ||
-             follows_start == that->follows_start);
-      follows_start = that->follows_start;
-    }
-    does_determine_word = that->does_determine_word;
-    does_determine_newline = that->does_determine_newline;
-    does_determine_start = that->does_determine_start;
-  }
-
   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;
-    being_expanded = false;
-    been_expanded = false;
   }
 
   bool being_analyzed: 1;
   bool been_analyzed: 1;
-  bool being_expanded: 1;
-  bool been_expanded: 1;
-
-  // These bits are set if this node must propagate forward information
-  // about the last character it consumed (or, in the case of 'start',
-  // if it is at the start of the input).
-  bool determine_word: 1;
-  bool determine_newline: 1;
-  bool determine_start: 1;
-
-  bool does_determine_word: 1;
-  bool does_determine_newline: 1;
-  bool does_determine_start: 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;
 
-  TriBool is_word: 2;
-  TriBool is_newline: 2;
-
   bool at_end: 1;
-
-  // These bits are set if the node can make assumptions about what
-  // the previous character was.
-  TriBool follows_word: 2;
-  TriBool follows_newline: 2;
-  TriBool follows_start: 2;
-
   bool visited: 1;
 };
 
 
-class ExpansionGuard {
- public:
-  explicit inline ExpansionGuard(NodeInfo* info) : info_(info) {
-    ASSERT(!info->being_expanded);
-    info->being_expanded = true;
-  }
-  inline ~ExpansionGuard() {
-    info_->being_expanded = false;
-  }
- private:
-  NodeInfo* info_;
-};
-
-
 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);
@@ skipping 13 matching lines @@
   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, GenerationVariant* variant) = 0;
   static const int kNodeIsTooComplexForGreedyLoops = -1;
   virtual int GreedyLoopTextLength() { return kNodeIsTooComplexForGreedyLoops; }
   Label* label() { return &label_; }
   static const int kMaxVariantsGenerated = 10;
 
-  RegExpNode* EnsureExpanded(NodeInfo* info);
-  virtual RegExpNode* ExpandLocal(NodeInfo* info) = 0;
-  virtual void ExpandChildren() = 0;
-
   // 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); }
 
@@ skipping 63 matching lines @@
   static ActionNode* BeginSubmatch(
       int stack_pointer_reg,
       int position_reg,
       RegExpNode* on_success);
   static ActionNode* PositiveSubmatchSuccess(
       int stack_pointer_reg,
       int restore_reg,
       RegExpNode* on_success);
   virtual void Accept(NodeVisitor* visitor);
   virtual bool Emit(RegExpCompiler* compiler, GenerationVariant* variant);
-  virtual RegExpNode* ExpandLocal(NodeInfo* info);
-  virtual void ExpandChildren();
   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;
@@ skipping 25 matching lines @@
       : 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 RegExpNode* ExpandLocal(NodeInfo* info);
-  virtual void ExpandChildren();
   virtual bool Emit(RegExpCompiler* compiler, GenerationVariant* variant);
   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:
-  void ExpandAtomChildren(RegExpAtom* that);
-  void ExpandCharClassChildren(RegExpCharacterClass* that);
-
   ZoneList<TextElement>* elms_;
 };
 
 
 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, GenerationVariant* variant);
   virtual RegExpNode* PropagateForward(NodeInfo* info);
-  virtual RegExpNode* ExpandLocal(NodeInfo* info);
-  virtual void ExpandChildren();
   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, GenerationVariant* variant);
   virtual RegExpNode* PropagateForward(NodeInfo* info);
-  virtual RegExpNode* ExpandLocal(NodeInfo* info);
-  virtual void ExpandChildren();
   virtual EndNode* Clone() { return new EndNode(*this); }
 
  protected:
   void EmitInfoChecks(RegExpMacroAssembler* macro, GenerationVariant* variant);
 
  private:
   Action action_;
 };
 
 
@@ skipping 48 matching lines @@
   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, GenerationVariant* variant);
   virtual RegExpNode* PropagateForward(NodeInfo* info);
-  virtual RegExpNode* ExpandLocal(NodeInfo* info);
-  virtual void ExpandChildren();
   virtual ChoiceNode* Clone() { return new ChoiceNode(*this); }
 
   bool being_calculated() { return being_calculated_; }
   void set_being_calculated(bool b) { being_calculated_ = b; }
 
  protected:
   int GreedyLoopTextLength(GuardedAlternative *alternative);
   ZoneList<GuardedAlternative>* alternatives_;
 
  private:
   friend class DispatchTableConstructor;
-  friend class AssertionPropagation;
+  friend class Analysis;
   void GenerateGuard(RegExpMacroAssembler* macro_assembler,
                      Guard *guard,
                      GenerationVariant* variant);
   DispatchTable* table_;
   bool being_calculated_;
 };
 
 
 class LoopChoiceNode: public ChoiceNode {
  public:
@@ skipping 169 matching lines @@
 // 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 |
 //   +-------+        +------------+
-//
-// At a later phase all nodes that determine information for their
-// following nodes are split into several 'sibling' nodes.  In this
-// case the first '.' is split into one node that only matches words
-// and one that only matches non-words.  The second '.' is also split,
-// into one node that assumes that the previous character was a word
-// character and one that assumes that is was non-word.  In this case
-// the result is
-//
-//         +------------------+        +------------------+
-//   /-->  | intersect(., \w) |  --->  | intersect(., \W) |
-//   |     +------------------+        +------------------+
-//   |                                 |    follows \w    |
-//   |                                 +------------------+
-// --?
-//   |     +------------------+        +------------------+
-//   \-->  | intersect(., \W) |  --->  | intersect(., \w) |
-//         +------------------+        +------------------+
-//                                     |    follows \W    |
-//                                     +------------------+
-//
-// This way we don't need to explicitly check the previous character
-// but can always assume that whoever consumed the previous character
-// has propagated the relevant information forward.
-class AssertionPropagation: public NodeVisitor {
+class Analysis: public NodeVisitor {
  public:
-  explicit AssertionPropagation(bool ignore_case)
+  explicit Analysis(bool ignore_case)
       : ignore_case_(ignore_case) { }
   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);
 
  private:
   bool ignore_case_;
 
-  DISALLOW_IMPLICIT_CONSTRUCTORS(AssertionPropagation);
+  DISALLOW_IMPLICIT_CONSTRUCTORS(Analysis);
 };
 
 
 struct RegExpCompileData {
   RegExpCompileData()
     : tree(NULL),
       node(NULL),
-      has_lookbehind(false),
       simple(true),
       capture_count(0) { }
   RegExpTree* tree;
   RegExpNode* node;
-  bool has_lookbehind;
   bool simple;
   Handle<String> error;
   int capture_count;
 };
 
 
 class RegExpEngine: public AllStatic {
  public:
   static Handle<FixedArray> 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_