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// Copyright 2016 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef V8_REGEXP_REGEXP_AST_H_
#define V8_REGEXP_REGEXP_AST_H_
#include "src/objects/js-regexp.h"
#include "src/objects/objects.h"
#include "src/objects/string.h"
#include "src/utils/utils.h"
#include "src/zone/zone-containers.h"
#include "src/zone/zone.h"
namespace v8 {
namespace internal {
#define FOR_EACH_REG_EXP_TREE_TYPE(VISIT) \
VISIT(Disjunction) \
VISIT(Alternative) \
VISIT(Assertion) \
VISIT(CharacterClass) \
VISIT(Atom) \
VISIT(Quantifier) \
VISIT(Capture) \
VISIT(Group) \
VISIT(Lookaround) \
VISIT(BackReference) \
VISIT(Empty) \
VISIT(Text)
#define FORWARD_DECLARE(Name) class RegExp##Name;
FOR_EACH_REG_EXP_TREE_TYPE(FORWARD_DECLARE)
#undef FORWARD_DECLARE
class RegExpCompiler;
class RegExpNode;
class RegExpTree;
class RegExpVisitor {
public:
virtual ~RegExpVisitor() = default;
#define MAKE_CASE(Name) \
virtual void* Visit##Name(RegExp##Name*, void* data) = 0;
FOR_EACH_REG_EXP_TREE_TYPE(MAKE_CASE)
#undef MAKE_CASE
};
// 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_;
};
// Represents code units in the range from from_ to to_, both ends are
// inclusive.
class CharacterRange {
public:
CharacterRange() : from_(0), to_(0) {}
// For compatibility with the CHECK_OK macro
CharacterRange(void* null) { DCHECK_NULL(null); } // NOLINT
V8_EXPORT_PRIVATE static void AddClassEscape(char type,
ZoneList<CharacterRange>* ranges,
Zone* zone);
// Add class escapes. Add case equivalent closure for \w and \W if necessary.
V8_EXPORT_PRIVATE static void AddClassEscape(
char type, ZoneList<CharacterRange>* ranges,
bool add_unicode_case_equivalents, Zone* zone);
static Vector<const int> GetWordBounds();
static inline CharacterRange Singleton(uc32 value) {
return CharacterRange(value, value);
}
static inline CharacterRange Range(uc32 from, uc32 to) {
DCHECK(0 <= from && to <= String::kMaxCodePoint);
DCHECK(static_cast<uint32_t>(from) <= static_cast<uint32_t>(to));
return CharacterRange(from, to);
}
static inline CharacterRange Everything() {
return CharacterRange(0, String::kMaxCodePoint);
}
static inline ZoneList<CharacterRange>* List(Zone* zone,
CharacterRange range) {
ZoneList<CharacterRange>* list =
new (zone) ZoneList<CharacterRange>(1, zone);
list->Add(range, zone);
return list;
}
bool Contains(uc32 i) { return from_ <= i && i <= to_; }
uc32 from() const { return from_; }
void set_from(uc32 value) { from_ = value; }
uc32 to() const { return to_; }
void set_to(uc32 value) { to_ = value; }
bool is_valid() { return from_ <= to_; }
bool IsEverything(uc32 max) { return from_ == 0 && to_ >= max; }
bool IsSingleton() { return (from_ == to_); }
V8_EXPORT_PRIVATE static void AddCaseEquivalents(
Isolate* isolate, Zone* zone, ZoneList<CharacterRange>* ranges,
bool is_one_byte);
// Whether a range list is in canonical form: Ranges ordered by from value,
// and ranges non-overlapping and non-adjacent.
V8_EXPORT_PRIVATE static bool IsCanonical(ZoneList<CharacterRange>* 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(ZoneList<CharacterRange>* ranges);
// Negate the contents of a character range in canonical form.
static void Negate(ZoneList<CharacterRange>* src,
ZoneList<CharacterRange>* dst, Zone* zone);
static const int kStartMarker = (1 << 24);
static const int kPayloadMask = (1 << 24) - 1;
private:
CharacterRange(uc32 from, uc32 to) : from_(from), to_(to) {}
uc32 from_;
uc32 to_;
};
class CharacterSet final {
public:
explicit CharacterSet(uc16 standard_set_type)
: ranges_(nullptr), standard_set_type_(standard_set_type) {}
explicit CharacterSet(ZoneList<CharacterRange>* ranges)
: ranges_(ranges), standard_set_type_(0) {}
ZoneList<CharacterRange>* ranges(Zone* zone);
uc16 standard_set_type() const { return standard_set_type_; }
void set_standard_set_type(uc16 special_set_type) {
standard_set_type_ = special_set_type;
}
bool is_standard() { return standard_set_type_ != 0; }
V8_EXPORT_PRIVATE void Canonicalize();
private:
ZoneList<CharacterRange>* ranges_;
// If non-zero, the value represents a standard set (e.g., all whitespace
// characters) without having to expand the ranges.
uc16 standard_set_type_;
};
class TextElement final {
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 {
DCHECK(text_type() == ATOM);
return reinterpret_cast<RegExpAtom*>(tree());
}
RegExpCharacterClass* char_class() const {
DCHECK(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_;
};
class RegExpTree : public ZoneObject {
public:
static const int kInfinity = kMaxInt;
virtual ~RegExpTree() = default;
virtual void* Accept(RegExpVisitor* visitor, void* data) = 0;
virtual RegExpNode* ToNode(RegExpCompiler* compiler,
RegExpNode* on_success) = 0;
virtual bool IsTextElement() { return false; }
virtual bool IsAnchoredAtStart() { return false; }
virtual bool IsAnchoredAtEnd() { return false; }
virtual int min_match() = 0;
virtual int max_match() = 0;
// Returns the interval of registers used for captures within this
// expression.
virtual Interval CaptureRegisters() { return Interval::Empty(); }
virtual void AppendToText(RegExpText* text, Zone* zone);
V8_EXPORT_PRIVATE std::ostream& Print(std::ostream& os,
Zone* zone); // NOLINT
#define MAKE_ASTYPE(Name) \
virtual RegExp##Name* As##Name(); \
virtual bool Is##Name();
FOR_EACH_REG_EXP_TREE_TYPE(MAKE_ASTYPE)
#undef MAKE_ASTYPE
};
class RegExpDisjunction final : public RegExpTree {
public:
explicit RegExpDisjunction(ZoneList<RegExpTree*>* alternatives);
void* Accept(RegExpVisitor* visitor, void* data) override;
RegExpNode* ToNode(RegExpCompiler* compiler, RegExpNode* on_success) override;
RegExpDisjunction* AsDisjunction() override;
Interval CaptureRegisters() override;
bool IsDisjunction() override;
bool IsAnchoredAtStart() override;
bool IsAnchoredAtEnd() override;
int min_match() override { return min_match_; }
int max_match() override { return max_match_; }
ZoneList<RegExpTree*>* alternatives() { return alternatives_; }
private:
bool SortConsecutiveAtoms(RegExpCompiler* compiler);
void RationalizeConsecutiveAtoms(RegExpCompiler* compiler);
void FixSingleCharacterDisjunctions(RegExpCompiler* compiler);
ZoneList<RegExpTree*>* alternatives_;
int min_match_;
int max_match_;
};
class RegExpAlternative final : public RegExpTree {
public:
explicit RegExpAlternative(ZoneList<RegExpTree*>* nodes);
void* Accept(RegExpVisitor* visitor, void* data) override;
RegExpNode* ToNode(RegExpCompiler* compiler, RegExpNode* on_success) override;
RegExpAlternative* AsAlternative() override;
Interval CaptureRegisters() override;
bool IsAlternative() override;
bool IsAnchoredAtStart() override;
bool IsAnchoredAtEnd() override;
int min_match() override { return min_match_; }
int max_match() override { return max_match_; }
ZoneList<RegExpTree*>* nodes() { return nodes_; }
private:
ZoneList<RegExpTree*>* nodes_;
int min_match_;
int max_match_;
};
class RegExpAssertion final : public RegExpTree {
public:
enum AssertionType {
START_OF_LINE,
START_OF_INPUT,
END_OF_LINE,
END_OF_INPUT,
BOUNDARY,
NON_BOUNDARY
};
RegExpAssertion(AssertionType type, JSRegExp::Flags flags)
: assertion_type_(type), flags_(flags) {}
void* Accept(RegExpVisitor* visitor, void* data) override;
RegExpNode* ToNode(RegExpCompiler* compiler, RegExpNode* on_success) override;
RegExpAssertion* AsAssertion() override;
bool IsAssertion() override;
bool IsAnchoredAtStart() override;
bool IsAnchoredAtEnd() override;
int min_match() override { return 0; }
int max_match() override { return 0; }
AssertionType assertion_type() { return assertion_type_; }
private:
const AssertionType assertion_type_;
const JSRegExp::Flags flags_;
};
class RegExpCharacterClass final : public RegExpTree {
public:
// NEGATED: The character class is negated and should match everything but
// the specified ranges.
// CONTAINS_SPLIT_SURROGATE: The character class contains part of a split
// surrogate and should not be unicode-desugared (crbug.com/641091).
enum Flag {
NEGATED = 1 << 0,
CONTAINS_SPLIT_SURROGATE = 1 << 1,
};
using CharacterClassFlags = base::Flags<Flag>;
RegExpCharacterClass(
Zone* zone, ZoneList<CharacterRange>* ranges, JSRegExp::Flags flags,
CharacterClassFlags character_class_flags = CharacterClassFlags())
: set_(ranges),
flags_(flags),
character_class_flags_(character_class_flags) {
// Convert the empty set of ranges to the negated Everything() range.
if (ranges->is_empty()) {
ranges->Add(CharacterRange::Everything(), zone);
character_class_flags_ ^= NEGATED;
}
}
RegExpCharacterClass(uc16 type, JSRegExp::Flags flags)
: set_(type),
flags_(flags),
character_class_flags_(CharacterClassFlags()) {}
void* Accept(RegExpVisitor* visitor, void* data) override;
RegExpNode* ToNode(RegExpCompiler* compiler, RegExpNode* on_success) override;
RegExpCharacterClass* AsCharacterClass() override;
bool IsCharacterClass() override;
bool IsTextElement() override { return true; }
int min_match() override { return 1; }
// The character class may match two code units for unicode regexps.
// TODO(yangguo): we should split this class for usage in TextElement, and
// make max_match() dependent on the character class content.
int max_match() override { return 2; }
void AppendToText(RegExpText* text, Zone* zone) override;
CharacterSet character_set() { 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(Zone* zone);
// 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-newline
// * : All characters, for advancing unanchored regexp
uc16 standard_type() const { return set_.standard_set_type(); }
ZoneList<CharacterRange>* ranges(Zone* zone) { return set_.ranges(zone); }
bool is_negated() const { return (character_class_flags_ & NEGATED) != 0; }
JSRegExp::Flags flags() const { return flags_; }
bool contains_split_surrogate() const {
return (character_class_flags_ & CONTAINS_SPLIT_SURROGATE) != 0;
}
private:
CharacterSet set_;
const JSRegExp::Flags flags_;
CharacterClassFlags character_class_flags_;
};
class RegExpAtom final : public RegExpTree {
public:
explicit RegExpAtom(Vector<const uc16> data, JSRegExp::Flags flags)
: data_(data), flags_(flags) {}
void* Accept(RegExpVisitor* visitor, void* data) override;
RegExpNode* ToNode(RegExpCompiler* compiler, RegExpNode* on_success) override;
RegExpAtom* AsAtom() override;
bool IsAtom() override;
bool IsTextElement() override { return true; }
int min_match() override { return data_.length(); }
int max_match() override { return data_.length(); }
void AppendToText(RegExpText* text, Zone* zone) override;
Vector<const uc16> data() { return data_; }
int length() { return data_.length(); }
JSRegExp::Flags flags() const { return flags_; }
bool ignore_case() const { return (flags_ & JSRegExp::kIgnoreCase) != 0; }
private:
Vector<const uc16> data_;
const JSRegExp::Flags flags_;
};
class RegExpText final : public RegExpTree {
public:
explicit RegExpText(Zone* zone) : elements_(2, zone), length_(0) {}
void* Accept(RegExpVisitor* visitor, void* data) override;
RegExpNode* ToNode(RegExpCompiler* compiler, RegExpNode* on_success) override;
RegExpText* AsText() override;
bool IsText() override;
bool IsTextElement() override { return true; }
int min_match() override { return length_; }
int max_match() override { return length_; }
void AppendToText(RegExpText* text, Zone* zone) override;
void AddElement(TextElement elm, Zone* zone) {
elements_.Add(elm, zone);
length_ += elm.length();
}
ZoneList<TextElement>* elements() { return &elements_; }
private:
ZoneList<TextElement> elements_;
int length_;
};
class RegExpQuantifier final : public RegExpTree {
public:
enum QuantifierType { GREEDY, NON_GREEDY, POSSESSIVE };
RegExpQuantifier(int min, int max, QuantifierType type, RegExpTree* body)
: body_(body),
min_(min),
max_(max),
quantifier_type_(type) {
if (min > 0 && body->min_match() > kInfinity / min) {
min_match_ = kInfinity;
} else {
min_match_ = min * body->min_match();
}
if (max > 0 && body->max_match() > kInfinity / max) {
max_match_ = kInfinity;
} else {
max_match_ = max * body->max_match();
}
}
void* Accept(RegExpVisitor* visitor, void* data) override;
RegExpNode* ToNode(RegExpCompiler* compiler, RegExpNode* on_success) override;
static RegExpNode* ToNode(int min, int max, bool is_greedy, RegExpTree* body,
RegExpCompiler* compiler, RegExpNode* on_success,
bool not_at_start = false);
RegExpQuantifier* AsQuantifier() override;
Interval CaptureRegisters() override;
bool IsQuantifier() override;
int min_match() override { return min_match_; }
int max_match() override { return max_match_; }
int min() { return min_; }
int max() { return max_; }
bool is_possessive() { return quantifier_type_ == POSSESSIVE; }
bool is_non_greedy() { return quantifier_type_ == NON_GREEDY; }
bool is_greedy() { return quantifier_type_ == GREEDY; }
RegExpTree* body() { return body_; }
private:
RegExpTree* body_;
int min_;
int max_;
int min_match_;
int max_match_;
QuantifierType quantifier_type_;
};
class RegExpCapture final : public RegExpTree {
public:
explicit RegExpCapture(int index)
: body_(nullptr), index_(index), name_(nullptr) {}
void* Accept(RegExpVisitor* visitor, void* data) override;
RegExpNode* ToNode(RegExpCompiler* compiler, RegExpNode* on_success) override;
static RegExpNode* ToNode(RegExpTree* body, int index,
RegExpCompiler* compiler, RegExpNode* on_success);
RegExpCapture* AsCapture() override;
bool IsAnchoredAtStart() override;
bool IsAnchoredAtEnd() override;
Interval CaptureRegisters() override;
bool IsCapture() override;
int min_match() override { return body_->min_match(); }
int max_match() override { return body_->max_match(); }
RegExpTree* body() { return body_; }
void set_body(RegExpTree* body) { body_ = body; }
int index() { return index_; }
const ZoneVector<uc16>* name() const { return name_; }
void set_name(const ZoneVector<uc16>* name) { name_ = name; }
static int StartRegister(int index) { return index * 2; }
static int EndRegister(int index) { return index * 2 + 1; }
private:
RegExpTree* body_;
int index_;
const ZoneVector<uc16>* name_;
};
class RegExpGroup final : public RegExpTree {
public:
explicit RegExpGroup(RegExpTree* body) : body_(body) {}
void* Accept(RegExpVisitor* visitor, void* data) override;
RegExpNode* ToNode(RegExpCompiler* compiler,
RegExpNode* on_success) override {
return body_->ToNode(compiler, on_success);
}
RegExpGroup* AsGroup() override;
bool IsAnchoredAtStart() override { return body_->IsAnchoredAtStart(); }
bool IsAnchoredAtEnd() override { return body_->IsAnchoredAtEnd(); }
bool IsGroup() override;
int min_match() override { return body_->min_match(); }
int max_match() override { return body_->max_match(); }
Interval CaptureRegisters() override { return body_->CaptureRegisters(); }
RegExpTree* body() { return body_; }
private:
RegExpTree* body_;
};
class RegExpLookaround final : public RegExpTree {
public:
enum Type { LOOKAHEAD, LOOKBEHIND };
RegExpLookaround(RegExpTree* body, bool is_positive, int capture_count,
int capture_from, Type type)
: body_(body),
is_positive_(is_positive),
capture_count_(capture_count),
capture_from_(capture_from),
type_(type) {}
void* Accept(RegExpVisitor* visitor, void* data) override;
RegExpNode* ToNode(RegExpCompiler* compiler, RegExpNode* on_success) override;
RegExpLookaround* AsLookaround() override;
Interval CaptureRegisters() override;
bool IsLookaround() override;
bool IsAnchoredAtStart() override;
int min_match() override { return 0; }
int max_match() override { return 0; }
RegExpTree* body() { return body_; }
bool is_positive() { return is_positive_; }
int capture_count() { return capture_count_; }
int capture_from() { return capture_from_; }
Type type() { return type_; }
class Builder {
public:
Builder(bool is_positive, RegExpNode* on_success,
int stack_pointer_register, int position_register,
int capture_register_count = 0, int capture_register_start = 0);
RegExpNode* on_match_success() { return on_match_success_; }
RegExpNode* ForMatch(RegExpNode* match);
private:
bool is_positive_;
RegExpNode* on_match_success_;
RegExpNode* on_success_;
int stack_pointer_register_;
int position_register_;
};
private:
RegExpTree* body_;
bool is_positive_;
int capture_count_;
int capture_from_;
Type type_;
};
class RegExpBackReference final : public RegExpTree {
public:
explicit RegExpBackReference(JSRegExp::Flags flags)
: capture_(nullptr), name_(nullptr), flags_(flags) {}
RegExpBackReference(RegExpCapture* capture, JSRegExp::Flags flags)
: capture_(capture), name_(nullptr), flags_(flags) {}
void* Accept(RegExpVisitor* visitor, void* data) override;
RegExpNode* ToNode(RegExpCompiler* compiler, RegExpNode* on_success) override;
RegExpBackReference* AsBackReference() override;
bool IsBackReference() override;
int min_match() override { return 0; }
// The back reference may be recursive, e.g. /(\2)(\1)/. To avoid infinite
// recursion, we give up. Ignorance is bliss.
int max_match() override { return kInfinity; }
int index() { return capture_->index(); }
RegExpCapture* capture() { return capture_; }
void set_capture(RegExpCapture* capture) { capture_ = capture; }
const ZoneVector<uc16>* name() const { return name_; }
void set_name(const ZoneVector<uc16>* name) { name_ = name; }
private:
RegExpCapture* capture_;
const ZoneVector<uc16>* name_;
const JSRegExp::Flags flags_;
};
class RegExpEmpty final : public RegExpTree {
public:
RegExpEmpty() = default;
void* Accept(RegExpVisitor* visitor, void* data) override;
RegExpNode* ToNode(RegExpCompiler* compiler, RegExpNode* on_success) override;
RegExpEmpty* AsEmpty() override;
bool IsEmpty() override;
int min_match() override { return 0; }
int max_match() override { return 0; }
};
} // namespace internal
} // namespace v8
#endif // V8_REGEXP_REGEXP_AST_H_