732 lines
25 KiB
C
732 lines
25 KiB
C
|
// Tencent is pleased to support the open source community by making RapidJSON available.
|
||
|
|
//
|
||
|
|
// Copyright (C) 2015 THL A29 Limited, a Tencent company, and Milo Yip. All rights reserved.
|
||
|
|
//
|
||
|
|
// Licensed under the MIT License (the "License"); you may not use this file except
|
||
|
|
// in compliance with the License. You may obtain a copy of the License at
|
||
|
|
//
|
||
|
|
// http://opensource.org/licenses/MIT
|
||
|
|
//
|
||
|
|
// Unless required by applicable law or agreed to in writing, software distributed
|
||
|
|
// under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
|
||
|
|
// CONDITIONS OF ANY KIND, either express or implied. See the License for the
|
||
|
|
// specific language governing permissions and limitations under the License.
|
||
|
|
|
||
|
|
#ifndef RAPIDJSON_INTERNAL_REGEX_H_
|
||
|
|
#define RAPIDJSON_INTERNAL_REGEX_H_
|
||
|
|
|
||
|
|
#include "../allocators.h"
|
||
|
|
#include "../stream.h"
|
||
|
|
#include "stack.h"
|
||
|
|
|
||
|
|
#ifdef __clang__
|
||
|
|
RAPIDJSON_DIAG_PUSH
|
||
|
|
RAPIDJSON_DIAG_OFF(padded)
|
||
|
|
RAPIDJSON_DIAG_OFF(switch-enum)
|
||
|
|
RAPIDJSON_DIAG_OFF(implicit-fallthrough)
|
||
|
|
#endif
|
||
|
|
|
||
|
|
#ifdef __GNUC__
|
||
|
|
RAPIDJSON_DIAG_PUSH
|
||
|
|
RAPIDJSON_DIAG_OFF(effc++)
|
||
|
|
#endif
|
||
|
|
|
||
|
|
#ifdef _MSC_VER
|
||
|
|
RAPIDJSON_DIAG_PUSH
|
||
|
|
RAPIDJSON_DIAG_OFF(4512) // assignment operator could not be generated
|
||
|
|
#endif
|
||
|
|
|
||
|
|
#ifndef RAPIDJSON_REGEX_VERBOSE
|
||
|
|
#define RAPIDJSON_REGEX_VERBOSE 0
|
||
|
|
#endif
|
||
|
|
|
||
|
|
RAPIDJSON_NAMESPACE_BEGIN
|
||
|
|
namespace internal {
|
||
|
|
|
||
|
|
///////////////////////////////////////////////////////////////////////////////
|
||
|
|
// DecodedStream
|
||
|
|
|
||
|
|
template <typename SourceStream, typename Encoding>
|
||
|
|
class DecodedStream {
|
||
|
|
public:
|
||
|
|
DecodedStream(SourceStream& ss) : ss_(ss), codepoint_() { Decode(); }
|
||
|
|
unsigned Peek() { return codepoint_; }
|
||
|
|
unsigned Take() {
|
||
|
|
unsigned c = codepoint_;
|
||
|
|
if (c) // No further decoding when '\0'
|
||
|
|
Decode();
|
||
|
|
return c;
|
||
|
|
}
|
||
|
|
|
||
|
|
private:
|
||
|
|
void Decode() {
|
||
|
|
if (!Encoding::Decode(ss_, &codepoint_))
|
||
|
|
codepoint_ = 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
SourceStream& ss_;
|
||
|
|
unsigned codepoint_;
|
||
|
|
};
|
||
|
|
|
||
|
|
///////////////////////////////////////////////////////////////////////////////
|
||
|
|
// GenericRegex
|
||
|
|
|
||
|
|
static const SizeType kRegexInvalidState = ~SizeType(0); //!< Represents an invalid index in GenericRegex::State::out, out1
|
||
|
|
static const SizeType kRegexInvalidRange = ~SizeType(0);
|
||
|
|
|
||
|
|
template <typename Encoding, typename Allocator>
|
||
|
|
class GenericRegexSearch;
|
||
|
|
|
||
|
|
//! Regular expression engine with subset of ECMAscript grammar.
|
||
|
|
/*!
|
||
|
|
Supported regular expression syntax:
|
||
|
|
- \c ab Concatenation
|
||
|
|
- \c a|b Alternation
|
||
|
|
- \c a? Zero or one
|
||
|
|
- \c a* Zero or more
|
||
|
|
- \c a+ One or more
|
||
|
|
- \c a{3} Exactly 3 times
|
||
|
|
- \c a{3,} At least 3 times
|
||
|
|
- \c a{3,5} 3 to 5 times
|
||
|
|
- \c (ab) Grouping
|
||
|
|
- \c ^a At the beginning
|
||
|
|
- \c a$ At the end
|
||
|
|
- \c . Any character
|
||
|
|
- \c [abc] Character classes
|
||
|
|
- \c [a-c] Character class range
|
||
|
|
- \c [a-z0-9_] Character class combination
|
||
|
|
- \c [^abc] Negated character classes
|
||
|
|
- \c [^a-c] Negated character class range
|
||
|
|
- \c [\b] Backspace (U+0008)
|
||
|
|
- \c \\| \\\\ ... Escape characters
|
||
|
|
- \c \\f Form feed (U+000C)
|
||
|
|
- \c \\n Line feed (U+000A)
|
||
|
|
- \c \\r Carriage return (U+000D)
|
||
|
|
- \c \\t Tab (U+0009)
|
||
|
|
- \c \\v Vertical tab (U+000B)
|
||
|
|
|
||
|
|
\note This is a Thompson NFA engine, implemented with reference to
|
||
|
|
Cox, Russ. "Regular Expression Matching Can Be Simple And Fast (but is slow in Java, Perl, PHP, Python, Ruby,...).",
|
||
|
|
https://swtch.com/~rsc/regexp/regexp1.html
|
||
|
|
*/
|
||
|
|
template <typename Encoding, typename Allocator = CrtAllocator>
|
||
|
|
class GenericRegex {
|
||
|
|
public:
|
||
|
|
typedef Encoding EncodingType;
|
||
|
|
typedef typename Encoding::Ch Ch;
|
||
|
|
template <typename, typename> friend class GenericRegexSearch;
|
||
|
|
|
||
|
|
GenericRegex(const Ch* source, Allocator* allocator = 0) :
|
||
|
|
states_(allocator, 256), ranges_(allocator, 256), root_(kRegexInvalidState), stateCount_(), rangeCount_(),
|
||
|
|
anchorBegin_(), anchorEnd_()
|
||
|
|
{
|
||
|
|
GenericStringStream<Encoding> ss(source);
|
||
|
|
DecodedStream<GenericStringStream<Encoding>, Encoding> ds(ss);
|
||
|
|
Parse(ds);
|
||
|
|
}
|
||
|
|
|
||
|
|
~GenericRegex() {}
|
||
|
|
|
||
|
|
bool IsValid() const {
|
||
|
|
return root_ != kRegexInvalidState;
|
||
|
|
}
|
||
|
|
|
||
|
|
private:
|
||
|
|
enum Operator {
|
||
|
|
kZeroOrOne,
|
||
|
|
kZeroOrMore,
|
||
|
|
kOneOrMore,
|
||
|
|
kConcatenation,
|
||
|
|
kAlternation,
|
||
|
|
kLeftParenthesis
|
||
|
|
};
|
||
|
|
|
||
|
|
static const unsigned kAnyCharacterClass = 0xFFFFFFFF; //!< For '.'
|
||
|
|
static const unsigned kRangeCharacterClass = 0xFFFFFFFE;
|
||
|
|
static const unsigned kRangeNegationFlag = 0x80000000;
|
||
|
|
|
||
|
|
struct Range {
|
||
|
|
unsigned start; //
|
||
|
|
unsigned end;
|
||
|
|
SizeType next;
|
||
|
|
};
|
||
|
|
|
||
|
|
struct State {
|
||
|
|
SizeType out; //!< Equals to kInvalid for matching state
|
||
|
|
SizeType out1; //!< Equals to non-kInvalid for split
|
||
|
|
SizeType rangeStart;
|
||
|
|
unsigned codepoint;
|
||
|
|
};
|
||
|
|
|
||
|
|
struct Frag {
|
||
|
|
Frag(SizeType s, SizeType o, SizeType m) : start(s), out(o), minIndex(m) {}
|
||
|
|
SizeType start;
|
||
|
|
SizeType out; //!< link-list of all output states
|
||
|
|
SizeType minIndex;
|
||
|
|
};
|
||
|
|
|
||
|
|
State& GetState(SizeType index) {
|
||
|
|
RAPIDJSON_ASSERT(index < stateCount_);
|
||
|
|
return states_.template Bottom<State>()[index];
|
||
|
|
}
|
||
|
|
|
||
|
|
const State& GetState(SizeType index) const {
|
||
|
|
RAPIDJSON_ASSERT(index < stateCount_);
|
||
|
|
return states_.template Bottom<State>()[index];
|
||
|
|
}
|
||
|
|
|
||
|
|
Range& GetRange(SizeType index) {
|
||
|
|
RAPIDJSON_ASSERT(index < rangeCount_);
|
||
|
|
return ranges_.template Bottom<Range>()[index];
|
||
|
|
}
|
||
|
|
|
||
|
|
const Range& GetRange(SizeType index) const {
|
||
|
|
RAPIDJSON_ASSERT(index < rangeCount_);
|
||
|
|
return ranges_.template Bottom<Range>()[index];
|
||
|
|
}
|
||
|
|
|
||
|
|
template <typename InputStream>
|
||
|
|
void Parse(DecodedStream<InputStream, Encoding>& ds) {
|
||
|
|
Allocator allocator;
|
||
|
|
Stack<Allocator> operandStack(&allocator, 256); // Frag
|
||
|
|
Stack<Allocator> operatorStack(&allocator, 256); // Operator
|
||
|
|
Stack<Allocator> atomCountStack(&allocator, 256); // unsigned (Atom per parenthesis)
|
||
|
|
|
||
|
|
*atomCountStack.template Push<unsigned>() = 0;
|
||
|
|
|
||
|
|
unsigned codepoint;
|
||
|
|
while (ds.Peek() != 0) {
|
||
|
|
switch (codepoint = ds.Take()) {
|
||
|
|
case '^':
|
||
|
|
anchorBegin_ = true;
|
||
|
|
break;
|
||
|
|
|
||
|
|
case '$':
|
||
|
|
anchorEnd_ = true;
|
||
|
|
break;
|
||
|
|
|
||
|
|
case '|':
|
||
|
|
while (!operatorStack.Empty() && *operatorStack.template Top<Operator>() < kAlternation)
|
||
|
|
if (!Eval(operandStack, *operatorStack.template Pop<Operator>(1)))
|
||
|
|
return;
|
||
|
|
*operatorStack.template Push<Operator>() = kAlternation;
|
||
|
|
*atomCountStack.template Top<unsigned>() = 0;
|
||
|
|
break;
|
||
|
|
|
||
|
|
case '(':
|
||
|
|
*operatorStack.template Push<Operator>() = kLeftParenthesis;
|
||
|
|
*atomCountStack.template Push<unsigned>() = 0;
|
||
|
|
break;
|
||
|
|
|
||
|
|
case ')':
|
||
|
|
while (!operatorStack.Empty() && *operatorStack.template Top<Operator>() != kLeftParenthesis)
|
||
|
|
if (!Eval(operandStack, *operatorStack.template Pop<Operator>(1)))
|
||
|
|
return;
|
||
|
|
if (operatorStack.Empty())
|
||
|
|
return;
|
||
|
|
operatorStack.template Pop<Operator>(1);
|
||
|
|
atomCountStack.template Pop<unsigned>(1);
|
||
|
|
ImplicitConcatenation(atomCountStack, operatorStack);
|
||
|
|
break;
|
||
|
|
|
||
|
|
case '?':
|
||
|
|
if (!Eval(operandStack, kZeroOrOne))
|
||
|
|
return;
|
||
|
|
break;
|
||
|
|
|
||
|
|
case '*':
|
||
|
|
if (!Eval(operandStack, kZeroOrMore))
|
||
|
|
return;
|
||
|
|
break;
|
||
|
|
|
||
|
|
case '+':
|
||
|
|
if (!Eval(operandStack, kOneOrMore))
|
||
|
|
return;
|
||
|
|
break;
|
||
|
|
|
||
|
|
case '{':
|
||
|
|
{
|
||
|
|
unsigned n, m;
|
||
|
|
if (!ParseUnsigned(ds, &n))
|
||
|
|
return;
|
||
|
|
|
||
|
|
if (ds.Peek() == ',') {
|
||
|
|
ds.Take();
|
||
|
|
if (ds.Peek() == '}')
|
||
|
|
m = kInfinityQuantifier;
|
||
|
|
else if (!ParseUnsigned(ds, &m) || m < n)
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
else
|
||
|
|
m = n;
|
||
|
|
|
||
|
|
if (!EvalQuantifier(operandStack, n, m) || ds.Peek() != '}')
|
||
|
|
return;
|
||
|
|
ds.Take();
|
||
|
|
}
|
||
|
|
break;
|
||
|
|
|
||
|
|
case '.':
|
||
|
|
PushOperand(operandStack, kAnyCharacterClass);
|
||
|
|
ImplicitConcatenation(atomCountStack, operatorStack);
|
||
|
|
break;
|
||
|
|
|
||
|
|
case '[':
|
||
|
|
{
|
||
|
|
SizeType range;
|
||
|
|
if (!ParseRange(ds, &range))
|
||
|
|
return;
|
||
|
|
SizeType s = NewState(kRegexInvalidState, kRegexInvalidState, kRangeCharacterClass);
|
||
|
|
GetState(s).rangeStart = range;
|
||
|
|
*operandStack.template Push<Frag>() = Frag(s, s, s);
|
||
|
|
}
|
||
|
|
ImplicitConcatenation(atomCountStack, operatorStack);
|
||
|
|
break;
|
||
|
|
|
||
|
|
case '\\': // Escape character
|
||
|
|
if (!CharacterEscape(ds, &codepoint))
|
||
|
|
return; // Unsupported escape character
|
||
|
|
// fall through to default
|
||
|
|
|
||
|
|
default: // Pattern character
|
||
|
|
PushOperand(operandStack, codepoint);
|
||
|
|
ImplicitConcatenation(atomCountStack, operatorStack);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
while (!operatorStack.Empty())
|
||
|
|
if (!Eval(operandStack, *operatorStack.template Pop<Operator>(1)))
|
||
|
|
return;
|
||
|
|
|
||
|
|
// Link the operand to matching state.
|
||
|
|
if (operandStack.GetSize() == sizeof(Frag)) {
|
||
|
|
Frag* e = operandStack.template Pop<Frag>(1);
|
||
|
|
Patch(e->out, NewState(kRegexInvalidState, kRegexInvalidState, 0));
|
||
|
|
root_ = e->start;
|
||
|
|
|
||
|
|
#if RAPIDJSON_REGEX_VERBOSE
|
||
|
|
printf("root: %d\n", root_);
|
||
|
|
for (SizeType i = 0; i < stateCount_ ; i++) {
|
||
|
|
State& s = GetState(i);
|
||
|
|
printf("[%2d] out: %2d out1: %2d c: '%c'\n", i, s.out, s.out1, (char)s.codepoint);
|
||
|
|
}
|
||
|
|
printf("\n");
|
||
|
|
#endif
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
SizeType NewState(SizeType out, SizeType out1, unsigned codepoint) {
|
||
|
|
State* s = states_.template Push<State>();
|
||
|
|
s->out = out;
|
||
|
|
s->out1 = out1;
|
||
|
|
s->codepoint = codepoint;
|
||
|
|
s->rangeStart = kRegexInvalidRange;
|
||
|
|
return stateCount_++;
|
||
|
|
}
|
||
|
|
|
||
|
|
void PushOperand(Stack<Allocator>& operandStack, unsigned codepoint) {
|
||
|
|
SizeType s = NewState(kRegexInvalidState, kRegexInvalidState, codepoint);
|
||
|
|
*operandStack.template Push<Frag>() = Frag(s, s, s);
|
||
|
|
}
|
||
|
|
|
||
|
|
void ImplicitConcatenation(Stack<Allocator>& atomCountStack, Stack<Allocator>& operatorStack) {
|
||
|
|
if (*atomCountStack.template Top<unsigned>())
|
||
|
|
*operatorStack.template Push<Operator>() = kConcatenation;
|
||
|
|
(*atomCountStack.template Top<unsigned>())++;
|
||
|
|
}
|
||
|
|
|
||
|
|
SizeType Append(SizeType l1, SizeType l2) {
|
||
|
|
SizeType old = l1;
|
||
|
|
while (GetState(l1).out != kRegexInvalidState)
|
||
|
|
l1 = GetState(l1).out;
|
||
|
|
GetState(l1).out = l2;
|
||
|
|
return old;
|
||
|
|
}
|
||
|
|
|
||
|
|
void Patch(SizeType l, SizeType s) {
|
||
|
|
for (SizeType next; l != kRegexInvalidState; l = next) {
|
||
|
|
next = GetState(l).out;
|
||
|
|
GetState(l).out = s;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
bool Eval(Stack<Allocator>& operandStack, Operator op) {
|
||
|
|
switch (op) {
|
||
|
|
case kConcatenation:
|
||
|
|
RAPIDJSON_ASSERT(operandStack.GetSize() >= sizeof(Frag) * 2);
|
||
|
|
{
|
||
|
|
Frag e2 = *operandStack.template Pop<Frag>(1);
|
||
|
|
Frag e1 = *operandStack.template Pop<Frag>(1);
|
||
|
|
Patch(e1.out, e2.start);
|
||
|
|
*operandStack.template Push<Frag>() = Frag(e1.start, e2.out, Min(e1.minIndex, e2.minIndex));
|
||
|
|
}
|
||
|
|
return true;
|
||
|
|
|
||
|
|
case kAlternation:
|
||
|
|
if (operandStack.GetSize() >= sizeof(Frag) * 2) {
|
||
|
|
Frag e2 = *operandStack.template Pop<Frag>(1);
|
||
|
|
Frag e1 = *operandStack.template Pop<Frag>(1);
|
||
|
|
SizeType s = NewState(e1.start, e2.start, 0);
|
||
|
|
*operandStack.template Push<Frag>() = Frag(s, Append(e1.out, e2.out), Min(e1.minIndex, e2.minIndex));
|
||
|
|
return true;
|
||
|
|
}
|
||
|
|
return false;
|
||
|
|
|
||
|
|
case kZeroOrOne:
|
||
|
|
if (operandStack.GetSize() >= sizeof(Frag)) {
|
||
|
|
Frag e = *operandStack.template Pop<Frag>(1);
|
||
|
|
SizeType s = NewState(kRegexInvalidState, e.start, 0);
|
||
|
|
*operandStack.template Push<Frag>() = Frag(s, Append(e.out, s), e.minIndex);
|
||
|
|
return true;
|
||
|
|
}
|
||
|
|
return false;
|
||
|
|
|
||
|
|
case kZeroOrMore:
|
||
|
|
if (operandStack.GetSize() >= sizeof(Frag)) {
|
||
|
|
Frag e = *operandStack.template Pop<Frag>(1);
|
||
|
|
SizeType s = NewState(kRegexInvalidState, e.start, 0);
|
||
|
|
Patch(e.out, s);
|
||
|
|
*operandStack.template Push<Frag>() = Frag(s, s, e.minIndex);
|
||
|
|
return true;
|
||
|
|
}
|
||
|
|
return false;
|
||
|
|
|
||
|
|
default:
|
||
|
|
RAPIDJSON_ASSERT(op == kOneOrMore);
|
||
|
|
if (operandStack.GetSize() >= sizeof(Frag)) {
|
||
|
|
Frag e = *operandStack.template Pop<Frag>(1);
|
||
|
|
SizeType s = NewState(kRegexInvalidState, e.start, 0);
|
||
|
|
Patch(e.out, s);
|
||
|
|
*operandStack.template Push<Frag>() = Frag(e.start, s, e.minIndex);
|
||
|
|
return true;
|
||
|
|
}
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
bool EvalQuantifier(Stack<Allocator>& operandStack, unsigned n, unsigned m) {
|
||
|
|
RAPIDJSON_ASSERT(n <= m);
|
||
|
|
RAPIDJSON_ASSERT(operandStack.GetSize() >= sizeof(Frag));
|
||
|
|
|
||
|
|
if (n == 0) {
|
||
|
|
if (m == 0) // a{0} not support
|
||
|
|
return false;
|
||
|
|
else if (m == kInfinityQuantifier)
|
||
|
|
Eval(operandStack, kZeroOrMore); // a{0,} -> a*
|
||
|
|
else {
|
||
|
|
Eval(operandStack, kZeroOrOne); // a{0,5} -> a?
|
||
|
|
for (unsigned i = 0; i < m - 1; i++)
|
||
|
|
CloneTopOperand(operandStack); // a{0,5} -> a? a? a? a? a?
|
||
|
|
for (unsigned i = 0; i < m - 1; i++)
|
||
|
|
Eval(operandStack, kConcatenation); // a{0,5} -> a?a?a?a?a?
|
||
|
|
}
|
||
|
|
return true;
|
||
|
|
}
|
||
|
|
|
||
|
|
for (unsigned i = 0; i < n - 1; i++) // a{3} -> a a a
|
||
|
|
CloneTopOperand(operandStack);
|
||
|
|
|
||
|
|
if (m == kInfinityQuantifier)
|
||
|
|
Eval(operandStack, kOneOrMore); // a{3,} -> a a a+
|
||
|
|
else if (m > n) {
|
||
|
|
CloneTopOperand(operandStack); // a{3,5} -> a a a a
|
||
|
|
Eval(operandStack, kZeroOrOne); // a{3,5} -> a a a a?
|
||
|
|
for (unsigned i = n; i < m - 1; i++)
|
||
|
|
CloneTopOperand(operandStack); // a{3,5} -> a a a a? a?
|
||
|
|
for (unsigned i = n; i < m; i++)
|
||
|
|
Eval(operandStack, kConcatenation); // a{3,5} -> a a aa?a?
|
||
|
|
}
|
||
|
|
|
||
|
|
for (unsigned i = 0; i < n - 1; i++)
|
||
|
|
Eval(operandStack, kConcatenation); // a{3} -> aaa, a{3,} -> aaa+, a{3.5} -> aaaa?a?
|
||
|
|
|
||
|
|
return true;
|
||
|
|
}
|
||
|
|
|
||
|
|
static SizeType Min(SizeType a, SizeType b) { return a < b ? a : b; }
|
||
|
|
|
||
|
|
void CloneTopOperand(Stack<Allocator>& operandStack) {
|
||
|
|
const Frag src = *operandStack.template Top<Frag>(); // Copy constructor to prevent invalidation
|
||
|
|
SizeType count = stateCount_ - src.minIndex; // Assumes top operand contains states in [src->minIndex, stateCount_)
|
||
|
|
State* s = states_.template Push<State>(count);
|
||
|
|
memcpy(s, &GetState(src.minIndex), count * sizeof(State));
|
||
|
|
for (SizeType j = 0; j < count; j++) {
|
||
|
|
if (s[j].out != kRegexInvalidState)
|
||
|
|
s[j].out += count;
|
||
|
|
if (s[j].out1 != kRegexInvalidState)
|
||
|
|
s[j].out1 += count;
|
||
|
|
}
|
||
|
|
*operandStack.template Push<Frag>() = Frag(src.start + count, src.out + count, src.minIndex + count);
|
||
|
|
stateCount_ += count;
|
||
|
|
}
|
||
|
|
|
||
|
|
template <typename InputStream>
|
||
|
|
bool ParseUnsigned(DecodedStream<InputStream, Encoding>& ds, unsigned* u) {
|
||
|
|
unsigned r = 0;
|
||
|
|
if (ds.Peek() < '0' || ds.Peek() > '9')
|
||
|
|
return false;
|
||
|
|
while (ds.Peek() >= '0' && ds.Peek() <= '9') {
|
||
|
|
if (r >= 429496729 && ds.Peek() > '5') // 2^32 - 1 = 4294967295
|
||
|
|
return false; // overflow
|
||
|
|
r = r * 10 + (ds.Take() - '0');
|
||
|
|
}
|
||
|
|
*u = r;
|
||
|
|
return true;
|
||
|
|
}
|
||
|
|
|
||
|
|
template <typename InputStream>
|
||
|
|
bool ParseRange(DecodedStream<InputStream, Encoding>& ds, SizeType* range) {
|
||
|
|
bool isBegin = true;
|
||
|
|
bool negate = false;
|
||
|
|
int step = 0;
|
||
|
|
SizeType start = kRegexInvalidRange;
|
||
|
|
SizeType current = kRegexInvalidRange;
|
||
|
|
unsigned codepoint;
|
||
|
|
while ((codepoint = ds.Take()) != 0) {
|
||
|
|
if (isBegin) {
|
||
|
|
isBegin = false;
|
||
|
|
if (codepoint == '^') {
|
||
|
|
negate = true;
|
||
|
|
continue;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
switch (codepoint) {
|
||
|
|
case ']':
|
||
|
|
if (start == kRegexInvalidRange)
|
||
|
|
return false; // Error: nothing inside []
|
||
|
|
if (step == 2) { // Add trailing '-'
|
||
|
|
SizeType r = NewRange('-');
|
||
|
|
RAPIDJSON_ASSERT(current != kRegexInvalidRange);
|
||
|
|
GetRange(current).next = r;
|
||
|
|
}
|
||
|
|
if (negate)
|
||
|
|
GetRange(start).start |= kRangeNegationFlag;
|
||
|
|
*range = start;
|
||
|
|
return true;
|
||
|
|
|
||
|
|
case '\\':
|
||
|
|
if (ds.Peek() == 'b') {
|
||
|
|
ds.Take();
|
||
|
|
codepoint = 0x0008; // Escape backspace character
|
||
|
|
}
|
||
|
|
else if (!CharacterEscape(ds, &codepoint))
|
||
|
|
return false;
|
||
|
|
// fall through to default
|
||
|
|
|
||
|
|
default:
|
||
|
|
switch (step) {
|
||
|
|
case 1:
|
||
|
|
if (codepoint == '-') {
|
||
|
|
step++;
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
// fall through to step 0 for other characters
|
||
|
|
|
||
|
|
case 0:
|
||
|
|
{
|
||
|
|
SizeType r = NewRange(codepoint);
|
||
|
|
if (current != kRegexInvalidRange)
|
||
|
|
GetRange(current).next = r;
|
||
|
|
if (start == kRegexInvalidRange)
|
||
|
|
start = r;
|
||
|
|
current = r;
|
||
|
|
}
|
||
|
|
step = 1;
|
||
|
|
break;
|
||
|
|
|
||
|
|
default:
|
||
|
|
RAPIDJSON_ASSERT(step == 2);
|
||
|
|
GetRange(current).end = codepoint;
|
||
|
|
step = 0;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
|
||
|
|
SizeType NewRange(unsigned codepoint) {
|
||
|
|
Range* r = ranges_.template Push<Range>();
|
||
|
|
r->start = r->end = codepoint;
|
||
|
|
r->next = kRegexInvalidRange;
|
||
|
|
return rangeCount_++;
|
||
|
|
}
|
||
|
|
|
||
|
|
template <typename InputStream>
|
||
|
|
bool CharacterEscape(DecodedStream<InputStream, Encoding>& ds, unsigned* escapedCodepoint) {
|
||
|
|
unsigned codepoint;
|
||
|
|
switch (codepoint = ds.Take()) {
|
||
|
|
case '^':
|
||
|
|
case '$':
|
||
|
|
case '|':
|
||
|
|
case '(':
|
||
|
|
case ')':
|
||
|
|
case '?':
|
||
|
|
case '*':
|
||
|
|
case '+':
|
||
|
|
case '.':
|
||
|
|
case '[':
|
||
|
|
case ']':
|
||
|
|
case '{':
|
||
|
|
case '}':
|
||
|
|
case '\\':
|
||
|
|
*escapedCodepoint = codepoint; return true;
|
||
|
|
case 'f': *escapedCodepoint = 0x000C; return true;
|
||
|
|
case 'n': *escapedCodepoint = 0x000A; return true;
|
||
|
|
case 'r': *escapedCodepoint = 0x000D; return true;
|
||
|
|
case 't': *escapedCodepoint = 0x0009; return true;
|
||
|
|
case 'v': *escapedCodepoint = 0x000B; return true;
|
||
|
|
default:
|
||
|
|
return false; // Unsupported escape character
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
Stack<Allocator> states_;
|
||
|
|
Stack<Allocator> ranges_;
|
||
|
|
SizeType root_;
|
||
|
|
SizeType stateCount_;
|
||
|
|
SizeType rangeCount_;
|
||
|
|
|
||
|
|
static const unsigned kInfinityQuantifier = ~0u;
|
||
|
|
|
||
|
|
// For SearchWithAnchoring()
|
||
|
|
bool anchorBegin_;
|
||
|
|
bool anchorEnd_;
|
||
|
|
};
|
||
|
|
|
||
|
|
template <typename RegexType, typename Allocator = CrtAllocator>
|
||
|
|
class GenericRegexSearch {
|
||
|
|
public:
|
||
|
|
typedef typename RegexType::EncodingType Encoding;
|
||
|
|
typedef typename Encoding::Ch Ch;
|
||
|
|
|
||
|
|
GenericRegexSearch(const RegexType& regex, Allocator* allocator = 0) :
|
||
|
|
regex_(regex), allocator_(allocator), ownAllocator_(0),
|
||
|
|
state0_(allocator, 0), state1_(allocator, 0), stateSet_()
|
||
|
|
{
|
||
|
|
RAPIDJSON_ASSERT(regex_.IsValid());
|
||
|
|
if (!allocator_)
|
||
|
|
ownAllocator_ = allocator_ = RAPIDJSON_NEW(Allocator());
|
||
|
|
stateSet_ = static_cast<unsigned*>(allocator_->Malloc(GetStateSetSize()));
|
||
|
|
state0_.template Reserve<SizeType>(regex_.stateCount_);
|
||
|
|
state1_.template Reserve<SizeType>(regex_.stateCount_);
|
||
|
|
}
|
||
|
|
|
||
|
|
~GenericRegexSearch() {
|
||
|
|
Allocator::Free(stateSet_);
|
||
|
|
RAPIDJSON_DELETE(ownAllocator_);
|
||
|
|
}
|
||
|
|
|
||
|
|
template <typename InputStream>
|
||
|
|
bool Match(InputStream& is) {
|
||
|
|
return SearchWithAnchoring(is, true, true);
|
||
|
|
}
|
||
|
|
|
||
|
|
bool Match(const Ch* s) {
|
||
|
|
GenericStringStream<Encoding> is(s);
|
||
|
|
return Match(is);
|
||
|
|
}
|
||
|
|
|
||
|
|
template <typename InputStream>
|
||
|
|
bool Search(InputStream& is) {
|
||
|
|
return SearchWithAnchoring(is, regex_.anchorBegin_, regex_.anchorEnd_);
|
||
|
|
}
|
||
|
|
|
||
|
|
bool Search(const Ch* s) {
|
||
|
|
GenericStringStream<Encoding> is(s);
|
||
|
|
return Search(is);
|
||
|
|
}
|
||
|
|
|
||
|
|
private:
|
||
|
|
typedef typename RegexType::State State;
|
||
|
|
typedef typename RegexType::Range Range;
|
||
|
|
|
||
|
|
template <typename InputStream>
|
||
|
|
bool SearchWithAnchoring(InputStream& is, bool anchorBegin, bool anchorEnd) {
|
||
|
|
DecodedStream<InputStream, Encoding> ds(is);
|
||
|
|
|
||
|
|
state0_.Clear();
|
||
|
|
Stack<Allocator> *current = &state0_, *next = &state1_;
|
||
|
|
const size_t stateSetSize = GetStateSetSize();
|
||
|
|
std::memset(stateSet_, 0, stateSetSize);
|
||
|
|
|
||
|
|
bool matched = AddState(*current, regex_.root_);
|
||
|
|
unsigned codepoint;
|
||
|
|
while (!current->Empty() && (codepoint = ds.Take()) != 0) {
|
||
|
|
std::memset(stateSet_, 0, stateSetSize);
|
||
|
|
next->Clear();
|
||
|
|
matched = false;
|
||
|
|
for (const SizeType* s = current->template Bottom<SizeType>(); s != current->template End<SizeType>(); ++s) {
|
||
|
|
const State& sr = regex_.GetState(*s);
|
||
|
|
if (sr.codepoint == codepoint ||
|
||
|
|
sr.codepoint == RegexType::kAnyCharacterClass ||
|
||
|
|
(sr.codepoint == RegexType::kRangeCharacterClass && MatchRange(sr.rangeStart, codepoint)))
|
||
|
|
{
|
||
|
|
matched = AddState(*next, sr.out) || matched;
|
||
|
|
if (!anchorEnd && matched)
|
||
|
|
return true;
|
||
|
|
}
|
||
|
|
if (!anchorBegin)
|
||
|
|
AddState(*next, regex_.root_);
|
||
|
|
}
|
||
|
|
internal::Swap(current, next);
|
||
|
|
}
|
||
|
|
|
||
|
|
return matched;
|
||
|
|
}
|
||
|
|
|
||
|
|
size_t GetStateSetSize() const {
|
||
|
|
return (regex_.stateCount_ + 31) / 32 * 4;
|
||
|
|
}
|
||
|
|
|
||
|
|
// Return whether the added states is a match state
|
||
|
|
bool AddState(Stack<Allocator>& l, SizeType index) {
|
||
|
|
RAPIDJSON_ASSERT(index != kRegexInvalidState);
|
||
|
|
|
||
|
|
const State& s = regex_.GetState(index);
|
||
|
|
if (s.out1 != kRegexInvalidState) { // Split
|
||
|
|
bool matched = AddState(l, s.out);
|
||
|
|
return AddState(l, s.out1) || matched;
|
||
|
|
}
|
||
|
|
else if (!(stateSet_[index >> 5] & (1 << (index & 31)))) {
|
||
|
|
stateSet_[index >> 5] |= (1 << (index & 31));
|
||
|
|
*l.template PushUnsafe<SizeType>() = index;
|
||
|
|
}
|
||
|
|
return s.out == kRegexInvalidState; // by using PushUnsafe() above, we can ensure s is not validated due to reallocation.
|
||
|
|
}
|
||
|
|
|
||
|
|
bool MatchRange(SizeType rangeIndex, unsigned codepoint) const {
|
||
|
|
bool yes = (regex_.GetRange(rangeIndex).start & RegexType::kRangeNegationFlag) == 0;
|
||
|
|
while (rangeIndex != kRegexInvalidRange) {
|
||
|
|
const Range& r = regex_.GetRange(rangeIndex);
|
||
|
|
if (codepoint >= (r.start & ~RegexType::kRangeNegationFlag) && codepoint <= r.end)
|
||
|
|
return yes;
|
||
|
|
rangeIndex = r.next;
|
||
|
|
}
|
||
|
|
return !yes;
|
||
|
|
}
|
||
|
|
|
||
|
|
const RegexType& regex_;
|
||
|
|
Allocator* allocator_;
|
||
|
|
Allocator* ownAllocator_;
|
||
|
|
Stack<Allocator> state0_;
|
||
|
|
Stack<Allocator> state1_;
|
||
|
|
uint32_t* stateSet_;
|
||
|
|
};
|
||
|
|
|
||
|
|
typedef GenericRegex<UTF8<> > Regex;
|
||
|
|
typedef GenericRegexSearch<Regex> RegexSearch;
|
||
|
|
|
||
|
|
} // namespace internal
|
||
|
|
RAPIDJSON_NAMESPACE_END
|
||
|
|
|
||
|
|
#ifdef __clang__
|
||
|
|
RAPIDJSON_DIAG_POP
|
||
|
|
#endif
|
||
|
|
|
||
|
|
#ifdef _MSC_VER
|
||
|
|
RAPIDJSON_DIAG_POP
|
||
|
|
#endif
|
||
|
|
|
||
|
|
#endif // RAPIDJSON_INTERNAL_REGEX_H_
|