Port and integrate the irregexp engine from V8

runtime/vm/regexp_ast.h

Index: runtime/vm/regexp_ast.h
diff --git a/runtime/vm/regexp_ast.h b/runtime/vm/regexp_ast.h
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+// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+#ifndef VM_REGEXP_AST_H_
+#define VM_REGEXP_AST_H_
+
+#include "platform/globals.h"
+#include "platform/utils.h"
+#include "vm/allocation.h"
+#include "vm/regexp.h"
+
+namespace dart {
+
+// Forward declarations.
+class RegExpAlternative;
+class RegExpAssertion;
+class RegExpAtom;
+class RegExpBackReference;
+class RegExpCapture;
+class RegExpCharacterClass;
+class RegExpCompiler;
+class RegExpDisjunction;
+class RegExpEmpty;
+class RegExpLookahead;
+class RegExpQuantifier;
+class RegExpText;
+
+
+class RegExpVisitor : public ValueObject {
+ public:
+  virtual ~RegExpVisitor() { }
+#define MAKE_CASE(Name)                                              \
+  virtual void* Visit##Name(RegExp##Name*, void* data) = 0;
+  FOR_EACH_REG_EXP_TREE_TYPE(MAKE_CASE)
+#undef MAKE_CASE
+};
+
+
+class RegExpTree : public ZoneAllocated {
+ public:
+  static const intptr_t kInfinity = kMaxInt32;
+  virtual ~RegExpTree() {}
+  virtual void* Accept(RegExpVisitor* visitor, void* data) = 0;
+  virtual RegExpNode* ToNode(RegExpCompiler* compiler,
+                             RegExpNode* on_success) = 0;
+  virtual bool IsTextElement() const { return false; }
+  virtual bool IsAnchoredAtStart() const { return false; }
+  virtual bool IsAnchoredAtEnd() const { return false; }
+  virtual intptr_t min_match() const = 0;
+  virtual intptr_t max_match() const = 0;
+  // Returns the interval of registers used for captures within this
+  // expression.
+  virtual Interval CaptureRegisters() const { return Interval::Empty(); }
+  virtual void AppendToText(RegExpText* text);
+  void Print();
+#define MAKE_ASTYPE(Name)                                                  \
+  virtual RegExp##Name* As##Name();                                        \
+  virtual bool Is##Name() const;
+  FOR_EACH_REG_EXP_TREE_TYPE(MAKE_ASTYPE)
+#undef MAKE_ASTYPE
+};
+
+
+class RegExpText : public RegExpTree {
+ public:
+  RegExpText() : elements_(2), length_(0) {}
+  virtual void* Accept(RegExpVisitor* visitor, void* data);
+  virtual RegExpNode* ToNode(RegExpCompiler* compiler,
+                             RegExpNode* on_success);
+  virtual RegExpText* AsText();
+  virtual bool IsText() const;
+  virtual bool IsTextElement() const { return true; }
+  virtual intptr_t min_match() const { return length_; }
+  virtual intptr_t max_match() const { return length_; }
+  virtual void AppendToText(RegExpText* text);
+  void AddElement(TextElement elm)  {
+    elements_.Add(elm);
+    length_ += elm.length();
+  }
+  GrowableArray<TextElement>* elements() { return &elements_; }
+ private:
+  GrowableArray<TextElement> elements_;
+  intptr_t length_;
+};
+
+
+class RegExpQuantifier : public RegExpTree {
+ public:
+  enum QuantifierType { GREEDY, NON_GREEDY, POSSESSIVE };
+  RegExpQuantifier(intptr_t min, intptr_t max,
+                   QuantifierType type, RegExpTree* body)
+      : body_(body),
+        min_(min),
+        max_(max),
+        min_match_(min * body->min_match()),
+        quantifier_type_(type) {
+    if (max > 0 && body->max_match() > kInfinity / max) {
+      max_match_ = kInfinity;
+    } else {
+      max_match_ = max * body->max_match();
+    }
+  }
+  virtual void* Accept(RegExpVisitor* visitor, void* data);
+  virtual RegExpNode* ToNode(RegExpCompiler* compiler,
+                             RegExpNode* on_success);
+  static RegExpNode* ToNode(intptr_t min,
+                            intptr_t max,
+                            bool is_greedy,
+                            RegExpTree* body,
+                            RegExpCompiler* compiler,
+                            RegExpNode* on_success,
+                            bool not_at_start = false);
+  virtual RegExpQuantifier* AsQuantifier();
+  virtual Interval CaptureRegisters() const;
+  virtual bool IsQuantifier() const;
+  virtual intptr_t min_match() const { return min_match_; }
+  virtual intptr_t max_match() const { return max_match_; }
+  intptr_t min() const { return min_; }
+  intptr_t max() const { return max_; }
+  bool is_possessive() const { return quantifier_type_ == POSSESSIVE; }
+  bool is_non_greedy() const { return quantifier_type_ == NON_GREEDY; }
+  bool is_greedy() const { return quantifier_type_ == GREEDY; }
+  RegExpTree* body() const { return body_; }
+
+ private:
+  RegExpTree* body_;
+  intptr_t min_;
+  intptr_t max_;
+  intptr_t min_match_;
+  intptr_t max_match_;
+  QuantifierType quantifier_type_;
+};
+
+
+class RegExpCapture : public RegExpTree {
+ public:
+  explicit RegExpCapture(RegExpTree* body, intptr_t index)
+      : body_(body), index_(index) { }
+  virtual void* Accept(RegExpVisitor* visitor, void* data);
+  virtual RegExpNode* ToNode(RegExpCompiler* compiler,
+                             RegExpNode* on_success);
+  static RegExpNode* ToNode(RegExpTree* body,
+                            intptr_t index,
+                            RegExpCompiler* compiler,
+                            RegExpNode* on_success);
+  virtual RegExpCapture* AsCapture();
+  virtual bool IsAnchoredAtStart() const;
+  virtual bool IsAnchoredAtEnd() const;
+  virtual Interval CaptureRegisters() const;
+  virtual bool IsCapture() const;
+  virtual intptr_t min_match() const { return body_->min_match(); }
+  virtual intptr_t max_match() const { return body_->max_match(); }
+  RegExpTree* body() const { return body_; }
+  intptr_t index() const { return index_; }
+  static intptr_t StartRegister(intptr_t index) { return index * 2; }
+  static intptr_t EndRegister(intptr_t index) { return index * 2 + 1; }
+
+ private:
+  RegExpTree* body_;
+  intptr_t index_;
+};
+
+
+class RegExpDisjunction : public RegExpTree {
+ public:
+  explicit RegExpDisjunction(ZoneGrowableArray<RegExpTree*>* alternatives);
+  virtual void* Accept(RegExpVisitor* visitor, void* data);
+  virtual RegExpNode* ToNode(RegExpCompiler* compiler,
+                             RegExpNode* on_success);
+  virtual RegExpDisjunction* AsDisjunction();
+  virtual Interval CaptureRegisters() const;
+  virtual bool IsDisjunction() const;
+  virtual bool IsAnchoredAtStart() const;
+  virtual bool IsAnchoredAtEnd() const;
+  virtual intptr_t min_match() const { return min_match_; }
+  virtual intptr_t max_match() const { return max_match_; }
+  ZoneGrowableArray<RegExpTree*>* alternatives() const { return alternatives_; }
+ private:
+  ZoneGrowableArray<RegExpTree*>* alternatives_;
+  intptr_t min_match_;
+  intptr_t max_match_;
+};
+
+
+class RegExpAlternative : public RegExpTree {
+ public:
+  explicit RegExpAlternative(ZoneGrowableArray<RegExpTree*>* nodes);
+  virtual void* Accept(RegExpVisitor* visitor, void* data);
+  virtual RegExpNode* ToNode(RegExpCompiler* compiler,
+                             RegExpNode* on_success);
+  virtual RegExpAlternative* AsAlternative();
+  virtual Interval CaptureRegisters() const;
+  virtual bool IsAlternative() const;
+  virtual bool IsAnchoredAtStart() const;
+  virtual bool IsAnchoredAtEnd() const;
+  virtual intptr_t min_match() const { return min_match_; }
+  virtual intptr_t max_match() const { return max_match_; }
+  ZoneGrowableArray<RegExpTree*>* nodes() const { return nodes_; }
+ private:
+  ZoneGrowableArray<RegExpTree*>* nodes_;
+  intptr_t min_match_;
+  intptr_t max_match_;
+};
+
+
+class RegExpAssertion : public RegExpTree {
+ public:
+  enum AssertionType {
+    START_OF_LINE,
+    START_OF_INPUT,
+    END_OF_LINE,
+    END_OF_INPUT,
+    BOUNDARY,
+    NON_BOUNDARY
+  };
+  explicit RegExpAssertion(AssertionType type) : assertion_type_(type) { }
+  virtual void* Accept(RegExpVisitor* visitor, void* data);
+  virtual RegExpNode* ToNode(RegExpCompiler* compiler,
+                             RegExpNode* on_success);
+  virtual RegExpAssertion* AsAssertion();
+  virtual bool IsAssertion() const;
+  virtual bool IsAnchoredAtStart() const;
+  virtual bool IsAnchoredAtEnd() const;
+  virtual intptr_t min_match() const { return 0; }
+  virtual intptr_t max_match() const { return 0; }
+  AssertionType assertion_type() const { return assertion_type_; }
+ private:
+  AssertionType assertion_type_;
+};
+
+
+class CharacterSet : public ValueObject {
+ public:
+  explicit CharacterSet(uint16_t standard_set_type)
+      : ranges_(NULL),
+        standard_set_type_(standard_set_type) {}
+  explicit CharacterSet(ZoneGrowableArray<CharacterRange>* ranges)
+      : ranges_(ranges),
+        standard_set_type_(0) {}
+  CharacterSet(const CharacterSet& that)
+      : ValueObject(),
+        ranges_(that.ranges_),
+        standard_set_type_(that.standard_set_type_) {}
+  ZoneGrowableArray<CharacterRange>* ranges();
+  uint16_t standard_set_type() const { return standard_set_type_; }
+  void set_standard_set_type(uint16_t special_set_type) {
+    standard_set_type_ = special_set_type;
+  }
+  bool is_standard() { return standard_set_type_ != 0; }
+  void Canonicalize();
+ private:
+  ZoneGrowableArray<CharacterRange>* ranges_;
+  // If non-zero, the value represents a standard set (e.g., all whitespace
+  // characters) without having to expand the ranges.
+  uint16_t standard_set_type_;
+};
+
+
+class RegExpCharacterClass : public RegExpTree {
+ public:
+  RegExpCharacterClass(ZoneGrowableArray<CharacterRange>* ranges,
+                       bool is_negated)
+      : set_(ranges),
+        is_negated_(is_negated) { }
+  explicit RegExpCharacterClass(uint16_t type)
+      : set_(type),
+        is_negated_(false) { }
+  virtual void* Accept(RegExpVisitor* visitor, void* data);
+  virtual RegExpNode* ToNode(RegExpCompiler* compiler,
+                             RegExpNode* on_success);
+  virtual RegExpCharacterClass* AsCharacterClass();
+  virtual bool IsCharacterClass() const;
+  virtual bool IsTextElement() const { return true; }
+  virtual intptr_t min_match() const { return 1; }
+  virtual intptr_t max_match() const { return 1; }
+  virtual void AppendToText(RegExpText* text);
+  CharacterSet character_set() const { return set_; }
+  // TODO(lrn): Remove need for complex version if is_standard that
+  // recognizes a mangled standard set and just do { return set_.is_special(); }
+  bool is_standard();
+  // Returns a value representing the standard character set if is_standard()
+  // returns true.
+  // Currently used values are:
+  // s : unicode whitespace
+  // S : unicode non-whitespace
+  // w : ASCII word character (digit, letter, underscore)
+  // W : non-ASCII word character
+  // d : ASCII digit
+  // D : non-ASCII digit
+  // . : non-unicode non-newline
+  // * : All characters
+  uint16_t standard_type() const { return set_.standard_set_type(); }
+  ZoneGrowableArray<CharacterRange>* ranges() {
+    return set_.ranges();
+  }
+  bool is_negated() const { return is_negated_; }
+
+ private:
+  CharacterSet set_;
+  bool is_negated_;
+};
+
+
+class RegExpAtom : public RegExpTree {
+ public:
+  explicit RegExpAtom(ZoneGrowableArray<uint16_t>* data) : data_(data) { }
+  virtual void* Accept(RegExpVisitor* visitor, void* data);
+  virtual RegExpNode* ToNode(RegExpCompiler* compiler,
+                             RegExpNode* on_success);
+  virtual RegExpAtom* AsAtom();
+  virtual bool IsAtom() const;
+  virtual bool IsTextElement() const { return true; }
+  virtual intptr_t min_match() const { return data_->length(); }
+  virtual intptr_t max_match() const { return data_->length(); }
+  virtual void AppendToText(RegExpText* text);
+  ZoneGrowableArray<uint16_t>* data() const { return data_; }
+  intptr_t length() const { return data_->length(); }
+ private:
+  ZoneGrowableArray<uint16_t>* data_;
+};
+
+
+class RegExpLookahead : public RegExpTree {
+ public:
+  RegExpLookahead(RegExpTree* body,
+                  bool is_positive,
+                  intptr_t capture_count,
+                  intptr_t capture_from)
+      : body_(body),
+        is_positive_(is_positive),
+        capture_count_(capture_count),
+        capture_from_(capture_from) { }
+
+  virtual void* Accept(RegExpVisitor* visitor, void* data);
+  virtual RegExpNode* ToNode(RegExpCompiler* compiler,
+                             RegExpNode* on_success);
+  virtual RegExpLookahead* AsLookahead();
+  virtual Interval CaptureRegisters() const;
+  virtual bool IsLookahead() const;
+  virtual bool IsAnchoredAtStart() const;
+  virtual intptr_t min_match() const { return 0; }
+  virtual intptr_t max_match() const { return 0; }
+  RegExpTree* body() const { return body_; }
+  bool is_positive() const { return is_positive_; }
+  intptr_t capture_count() const { return capture_count_; }
+  intptr_t capture_from() const { return capture_from_; }
+
+ private:
+  RegExpTree* body_;
+  bool is_positive_;
+  intptr_t capture_count_;
+  intptr_t capture_from_;
+};
+
+
+class RegExpBackReference : public RegExpTree {
+ public:
+  explicit RegExpBackReference(RegExpCapture* capture)
+      : capture_(capture) { }
+  virtual void* Accept(RegExpVisitor* visitor, void* data);
+  virtual RegExpNode* ToNode(RegExpCompiler* compiler,
+                             RegExpNode* on_success);
+  virtual RegExpBackReference* AsBackReference();
+  virtual bool IsBackReference() const;
+  virtual intptr_t min_match() const { return 0; }
+  virtual intptr_t max_match() const { return capture_->max_match(); }
+  intptr_t index() const { return capture_->index(); }
+  RegExpCapture* capture() const { return capture_; }
+ private:
+  RegExpCapture* capture_;
+};
+
+
+class RegExpEmpty : public RegExpTree {
+ public:
+  RegExpEmpty() { }
+  virtual void* Accept(RegExpVisitor* visitor, void* data);
+  virtual RegExpNode* ToNode(RegExpCompiler* compiler,
+                             RegExpNode* on_success);
+  virtual RegExpEmpty* AsEmpty();
+  virtual bool IsEmpty() const;
+  virtual intptr_t min_match() const { return 0; }
+  virtual intptr_t max_match() const { return 0; }
+  static RegExpEmpty* GetInstance() {
+    static RegExpEmpty* instance = ::new RegExpEmpty();
+    return instance;
+  }
+};
+
+}  // namespace dart
+
+#endif  // VM_REGEXP_AST_H_