Merge of master

1 files changed, 728 insertions, 0 deletions

diff --git a/src/3rdparty/webkit/JavaScriptCore/yarr/RegexCompiler.cpp b/src/3rdparty/webkit/JavaScriptCore/yarr/RegexCompiler.cpp
new file mode 100644
index 0000000..c7b3c81
--- /dev/null
+++ b/src/3rdparty/webkit/JavaScriptCore/yarr/RegexCompiler.cpp
@@ -0,0 +1,728 @@
+/*
+ * Copyright (C) 2009 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. 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 with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#include "config.h"
+#include "RegexCompiler.h"
+
+#include "RegexInterpreter.h"
+#include "RegexPattern.h"
+#include <wtf/Vector.h>
+
+#if ENABLE(YARR)
+
+using namespace WTF;
+
+namespace JSC { namespace Yarr {
+
+class CharacterClassConstructor {
+public:
+    CharacterClassConstructor(bool isCaseInsensitive = false)
+        : m_isCaseInsensitive(isCaseInsensitive)
+    {
+    }
+    
+    void reset()
+    {
+        m_matches.clear();
+        m_ranges.clear();
+        m_matchesUnicode.clear();
+        m_rangesUnicode.clear();
+    }
+
+    void append(const CharacterClass* other)
+    {
+        for (size_t i = 0; i < other->m_matches.size(); ++i)
+            addSorted(m_matches, other->m_matches[i]);
+        for (size_t i = 0; i < other->m_ranges.size(); ++i)
+            addSortedRange(m_ranges, other->m_ranges[i].begin, other->m_ranges[i].end);
+        for (size_t i = 0; i < other->m_matchesUnicode.size(); ++i)
+            addSorted(m_matchesUnicode, other->m_matchesUnicode[i]);
+        for (size_t i = 0; i < other->m_rangesUnicode.size(); ++i)
+            addSortedRange(m_rangesUnicode, other->m_rangesUnicode[i].begin, other->m_rangesUnicode[i].end);
+    }
+
+    void putChar(UChar ch)
+    {
+        if (ch <= 0x7f) {
+            if (m_isCaseInsensitive && isASCIIAlpha(ch)) {
+                addSorted(m_matches, toASCIIUpper(ch));
+                addSorted(m_matches, toASCIILower(ch));
+            } else
+                addSorted(m_matches, ch);
+        } else {
+            UChar upper, lower;
+            if (m_isCaseInsensitive && ((upper = Unicode::toUpper(ch)) != (lower = Unicode::toLower(ch)))) {
+                addSorted(m_matchesUnicode, upper);
+                addSorted(m_matchesUnicode, lower);
+            } else
+                addSorted(m_matchesUnicode, ch);
+        }
+    }
+
+    // returns true if this character has another case, and 'ch' is the upper case form.
+    static inline bool isUnicodeUpper(UChar ch)
+    {
+        return ch != Unicode::toLower(ch);
+    }
+
+    // returns true if this character has another case, and 'ch' is the lower case form.
+    static inline bool isUnicodeLower(UChar ch)
+    {
+        return ch != Unicode::toUpper(ch);
+    }
+
+    void putRange(UChar lo, UChar hi)
+    {
+        if (lo <= 0x7f) {
+            char asciiLo = lo;
+            char asciiHi = std::min(hi, (UChar)0x7f);
+            addSortedRange(m_ranges, lo, asciiHi);
+            
+            if (m_isCaseInsensitive) {
+                if ((asciiLo <= 'Z') && (asciiHi >= 'A'))
+                    addSortedRange(m_ranges, std::max(asciiLo, 'A')+('a'-'A'), std::min(asciiHi, 'Z')+('a'-'A'));
+                if ((asciiLo <= 'z') && (asciiHi >= 'a'))
+                    addSortedRange(m_ranges, std::max(asciiLo, 'a')+('A'-'a'), std::min(asciiHi, 'z')+('A'-'a'));
+            }
+        }
+        if (hi >= 0x80) {
+            uint32_t unicodeCurr = std::max(lo, (UChar)0x80);
+            addSortedRange(m_rangesUnicode, unicodeCurr, hi);
+            
+            if (m_isCaseInsensitive) {
+                while (unicodeCurr <= hi) {
+                    // If the upper bound of the range (hi) is 0xffff, the increments to
+                    // unicodeCurr in this loop may take it to 0x10000.  This is fine
+                    // (if so we won't re-enter the loop, since the loop condition above
+                    // will definitely fail) - but this does mean we cannot use a UChar
+                    // to represent unicodeCurr, we must use a 32-bit value instead.
+                    ASSERT(unicodeCurr <= 0xffff);
+
+                    if (isUnicodeUpper(unicodeCurr)) {
+                        UChar lowerCaseRangeBegin = Unicode::toLower(unicodeCurr);
+                        UChar lowerCaseRangeEnd = lowerCaseRangeBegin;
+                        while ((++unicodeCurr <= hi) && isUnicodeUpper(unicodeCurr) && (Unicode::toLower(unicodeCurr) == (lowerCaseRangeEnd + 1)))
+                            lowerCaseRangeEnd++;
+                        addSortedRange(m_rangesUnicode, lowerCaseRangeBegin, lowerCaseRangeEnd);
+                    } else if (isUnicodeLower(unicodeCurr)) {
+                        UChar upperCaseRangeBegin = Unicode::toUpper(unicodeCurr);
+                        UChar upperCaseRangeEnd = upperCaseRangeBegin;
+                        while ((++unicodeCurr <= hi) && isUnicodeLower(unicodeCurr) && (Unicode::toUpper(unicodeCurr) == (upperCaseRangeEnd + 1)))
+                            upperCaseRangeEnd++;
+                        addSortedRange(m_rangesUnicode, upperCaseRangeBegin, upperCaseRangeEnd);
+                    } else
+                        ++unicodeCurr;
+                }
+            }
+        }
+    }
+
+    CharacterClass* charClass()
+    {
+        CharacterClass* characterClass = new CharacterClass();
+
+        characterClass->m_matches.append(m_matches);
+        characterClass->m_ranges.append(m_ranges);
+        characterClass->m_matchesUnicode.append(m_matchesUnicode);
+        characterClass->m_rangesUnicode.append(m_rangesUnicode);
+
+        reset();
+
+        return characterClass;
+    }
+
+private:
+    void addSorted(Vector<UChar>& matches, UChar ch)
+    {
+        unsigned pos = 0;
+        unsigned range = matches.size();
+
+        // binary chop, find position to insert char.
+        while (range) {
+            unsigned index = range >> 1;
+
+            int val = matches[pos+index] - ch;
+            if (!val)
+                return;
+            else if (val > 0)
+                range = index;
+            else {
+                pos += (index+1);
+                range -= (index+1);
+            }
+        }
+        
+        if (pos == matches.size())
+            matches.append(ch);
+        else
+            matches.insert(pos, ch);
+    }
+
+    void addSortedRange(Vector<CharacterRange>& ranges, UChar lo, UChar hi)
+    {
+        unsigned end = ranges.size();
+        
+        // Simple linear scan - I doubt there are that many ranges anyway...
+        // feel free to fix this with something faster (eg binary chop).
+        for (unsigned i = 0; i < end; ++i) {
+            // does the new range fall before the current position in the array
+            if (hi < ranges[i].begin) {
+                // optional optimization: concatenate appending ranges? - may not be worthwhile.
+                if (hi == (ranges[i].begin - 1)) {
+                    ranges[i].begin = lo;
+                    return;
+                }
+                ranges.insert(i, CharacterRange(lo, hi));
+                return;
+            }
+            // Okay, since we didn't hit the last case, the end of the new range is definitely at or after the begining
+            // If the new range start at or before the end of the last range, then the overlap (if it starts one after the
+            // end of the last range they concatenate, which is just as good.
+            if (lo <= (ranges[i].end + 1)) {
+                // found an intersect! we'll replace this entry in the array.
+                ranges[i].begin = std::min(ranges[i].begin, lo);
+                ranges[i].end = std::max(ranges[i].end, hi);
+
+                // now check if the new range can subsume any subsequent ranges.
+                unsigned next = i+1;
+                // each iteration of the loop we will either remove something from the list, or break the loop.
+                while (next < ranges.size()) {
+                    if (ranges[next].begin <= (ranges[i].end + 1)) {
+                        // the next entry now overlaps / concatenates this one.
+                        ranges[i].end = std::max(ranges[i].end, ranges[next].end);
+                        ranges.remove(next);
+                    } else
+                        break;
+                }
+                
+                return;
+            }
+        }
+
+        // CharacterRange comes after all existing ranges.
+        ranges.append(CharacterRange(lo, hi));
+    }
+
+    bool m_isCaseInsensitive;
+
+    Vector<UChar> m_matches;
+    Vector<CharacterRange> m_ranges;
+    Vector<UChar> m_matchesUnicode;
+    Vector<CharacterRange> m_rangesUnicode;
+};
+
+
+CharacterClass* newlineCreate()
+{
+    CharacterClass* characterClass = new CharacterClass();
+
+    characterClass->m_matches.append('\n');
+    characterClass->m_matches.append('\r');
+    characterClass->m_matchesUnicode.append(0x2028);
+    characterClass->m_matchesUnicode.append(0x2029);
+    
+    return characterClass;
+}
+
+CharacterClass* digitsCreate()
+{
+    CharacterClass* characterClass = new CharacterClass();
+
+    characterClass->m_ranges.append(CharacterRange('0', '9'));
+    
+    return characterClass;
+}
+
+CharacterClass* spacesCreate()
+{
+    CharacterClass* characterClass = new CharacterClass();
+
+    characterClass->m_matches.append(' ');
+    characterClass->m_ranges.append(CharacterRange('\t', '\r'));
+    characterClass->m_matchesUnicode.append(0x00a0);
+    characterClass->m_matchesUnicode.append(0x1680);
+    characterClass->m_matchesUnicode.append(0x180e);
+    characterClass->m_matchesUnicode.append(0x2028);
+    characterClass->m_matchesUnicode.append(0x2029);
+    characterClass->m_matchesUnicode.append(0x202f);
+    characterClass->m_matchesUnicode.append(0x205f);
+    characterClass->m_matchesUnicode.append(0x3000);
+    characterClass->m_rangesUnicode.append(CharacterRange(0x2000, 0x200a));
+    
+    return characterClass;
+}
+
+CharacterClass* wordcharCreate()
+{
+    CharacterClass* characterClass = new CharacterClass();
+
+    characterClass->m_matches.append('_');
+    characterClass->m_ranges.append(CharacterRange('0', '9'));
+    characterClass->m_ranges.append(CharacterRange('A', 'Z'));
+    characterClass->m_ranges.append(CharacterRange('a', 'z'));
+    
+    return characterClass;
+}
+
+CharacterClass* nondigitsCreate()
+{
+    CharacterClass* characterClass = new CharacterClass();
+
+    characterClass->m_ranges.append(CharacterRange(0, '0' - 1));
+    characterClass->m_ranges.append(CharacterRange('9' + 1, 0x7f));
+    characterClass->m_rangesUnicode.append(CharacterRange(0x80, 0xffff));
+    
+    return characterClass;
+}
+
+CharacterClass* nonspacesCreate()
+{
+    CharacterClass* characterClass = new CharacterClass();
+
+    characterClass->m_ranges.append(CharacterRange(0, '\t' - 1));
+    characterClass->m_ranges.append(CharacterRange('\r' + 1, ' ' - 1));
+    characterClass->m_ranges.append(CharacterRange(' ' + 1, 0x7f));
+    characterClass->m_rangesUnicode.append(CharacterRange(0x0080, 0x009f));
+    characterClass->m_rangesUnicode.append(CharacterRange(0x00a1, 0x167f));
+    characterClass->m_rangesUnicode.append(CharacterRange(0x1681, 0x180d));
+    characterClass->m_rangesUnicode.append(CharacterRange(0x180f, 0x1fff));
+    characterClass->m_rangesUnicode.append(CharacterRange(0x200b, 0x2027));
+    characterClass->m_rangesUnicode.append(CharacterRange(0x202a, 0x202e));
+    characterClass->m_rangesUnicode.append(CharacterRange(0x2030, 0x205e));
+    characterClass->m_rangesUnicode.append(CharacterRange(0x2060, 0x2fff));
+    characterClass->m_rangesUnicode.append(CharacterRange(0x3001, 0xffff));
+    
+    return characterClass;
+}
+
+CharacterClass* nonwordcharCreate()
+{
+    CharacterClass* characterClass = new CharacterClass();
+
+    characterClass->m_matches.append('`');
+    characterClass->m_ranges.append(CharacterRange(0, '0' - 1));
+    characterClass->m_ranges.append(CharacterRange('9' + 1, 'A' - 1));
+    characterClass->m_ranges.append(CharacterRange('Z' + 1, '_' - 1));
+    characterClass->m_ranges.append(CharacterRange('z' + 1, 0x7f));
+    characterClass->m_rangesUnicode.append(CharacterRange(0x80, 0xffff));
+
+    return characterClass;
+}
+
+
+class RegexPatternConstructor {
+public:
+    RegexPatternConstructor(RegexPattern& pattern)
+        : m_pattern(pattern)
+        , m_characterClassConstructor(pattern.m_ignoreCase)
+    {
+    }
+
+    ~RegexPatternConstructor()
+    {
+    }
+
+    void reset()
+    {
+        m_pattern.reset();
+        m_characterClassConstructor.reset();
+    }
+    
+    void assertionBOL()
+    {
+        m_alternative->m_terms.append(PatternTerm::BOL());
+    }
+    void assertionEOL()
+    {
+        m_alternative->m_terms.append(PatternTerm::EOL());
+    }
+    void assertionWordBoundary(bool invert)
+    {
+        m_alternative->m_terms.append(PatternTerm::WordBoundary(invert));
+    }
+
+    void atomPatternCharacter(UChar ch)
+    {
+        // We handle case-insensitive checking of unicode characters which do have both
+        // cases by handling them as if they were defined using a CharacterClass.
+        if (m_pattern.m_ignoreCase && !isASCII(ch) && (Unicode::toUpper(ch) != Unicode::toLower(ch))) {
+            atomCharacterClassBegin();
+            atomCharacterClassAtom(ch);
+            atomCharacterClassEnd();
+        } else
+            m_alternative->m_terms.append(PatternTerm(ch));
+    }
+
+    void atomBuiltInCharacterClass(BuiltInCharacterClassID classID, bool invert)
+    {
+        switch (classID) {
+        case DigitClassID:
+            m_alternative->m_terms.append(PatternTerm(m_pattern.digitsCharacterClass(), invert));
+            break;
+        case SpaceClassID:
+            m_alternative->m_terms.append(PatternTerm(m_pattern.spacesCharacterClass(), invert));
+            break;
+        case WordClassID:
+            m_alternative->m_terms.append(PatternTerm(m_pattern.wordcharCharacterClass(), invert));
+            break;
+        case NewlineClassID:
+            m_alternative->m_terms.append(PatternTerm(m_pattern.newlineCharacterClass(), invert));
+            break;
+        }
+    }
+
+    void atomCharacterClassBegin(bool invert = false)
+    {
+        m_invertCharacterClass = invert;
+    }
+
+    void atomCharacterClassAtom(UChar ch)
+    {
+        m_characterClassConstructor.putChar(ch);
+    }
+
+    void atomCharacterClassRange(UChar begin, UChar end)
+    {
+        m_characterClassConstructor.putRange(begin, end);
+    }
+
+    void atomCharacterClassBuiltIn(BuiltInCharacterClassID classID, bool invert)
+    {
+        ASSERT(classID != NewlineClassID);
+
+        switch (classID) {
+        case DigitClassID:
+            m_characterClassConstructor.append(invert ? m_pattern.nondigitsCharacterClass() : m_pattern.digitsCharacterClass());
+            break;
+        
+        case SpaceClassID:
+            m_characterClassConstructor.append(invert ? m_pattern.nonspacesCharacterClass() : m_pattern.spacesCharacterClass());
+            break;
+        
+        case WordClassID:
+            m_characterClassConstructor.append(invert ? m_pattern.nonwordcharCharacterClass() : m_pattern.wordcharCharacterClass());
+            break;
+        
+        default:
+            ASSERT_NOT_REACHED();
+        }
+    }
+
+    void atomCharacterClassEnd()
+    {
+        CharacterClass* newCharacterClass = m_characterClassConstructor.charClass();
+        m_pattern.m_userCharacterClasses.append(newCharacterClass);
+        m_alternative->m_terms.append(PatternTerm(newCharacterClass, m_invertCharacterClass));
+    }
+
+    void atomParenthesesSubpatternBegin(bool capture = true)
+    {
+        unsigned subpatternId = m_pattern.m_numSubpatterns + 1;
+        if (capture)
+            m_pattern.m_numSubpatterns++;
+
+        PatternDisjunction* parenthesesDisjunction = new PatternDisjunction(m_alternative);
+        m_pattern.m_disjunctions.append(parenthesesDisjunction);
+        m_alternative->m_terms.append(PatternTerm(PatternTerm::TypeParenthesesSubpattern, subpatternId, parenthesesDisjunction, capture));
+        m_alternative = parenthesesDisjunction->addNewAlternative();
+    }
+
+    void atomParentheticalAssertionBegin(bool invert = false)
+    {
+        PatternDisjunction* parenthesesDisjunction = new PatternDisjunction(m_alternative);
+        m_pattern.m_disjunctions.append(parenthesesDisjunction);
+        m_alternative->m_terms.append(PatternTerm(PatternTerm::TypeParentheticalAssertion, m_pattern.m_numSubpatterns + 1, parenthesesDisjunction, invert));
+        m_alternative = parenthesesDisjunction->addNewAlternative();
+    }
+
+    void atomParenthesesEnd()
+    {
+        ASSERT(m_alternative->m_parent);
+        ASSERT(m_alternative->m_parent->m_parent);
+        m_alternative = m_alternative->m_parent->m_parent;
+        
+        m_alternative->lastTerm().parentheses.lastSubpatternId = m_pattern.m_numSubpatterns;
+    }
+
+    void atomBackReference(unsigned subpatternId)
+    {
+        ASSERT(subpatternId);
+        m_pattern.m_maxBackReference = std::max(m_pattern.m_maxBackReference, subpatternId);
+
+        if (subpatternId > m_pattern.m_numSubpatterns) {
+            m_alternative->m_terms.append(PatternTerm::ForwardReference());
+            return;
+        }
+
+        PatternAlternative* currentAlternative = m_alternative;
+        ASSERT(currentAlternative);
+
+        // Note to self: if we waited until the AST was baked, we could also remove forwards refs 
+        while ((currentAlternative = currentAlternative->m_parent->m_parent)) {
+            PatternTerm& term = currentAlternative->lastTerm();
+            ASSERT((term.type == PatternTerm::TypeParenthesesSubpattern) || (term.type == PatternTerm::TypeParentheticalAssertion));
+
+            if ((term.type == PatternTerm::TypeParenthesesSubpattern) && term.invertOrCapture && (subpatternId == term.subpatternId)) {
+                m_alternative->m_terms.append(PatternTerm::ForwardReference());
+                return;
+            }
+        }
+
+        m_alternative->m_terms.append(PatternTerm(subpatternId));
+    }
+
+    PatternDisjunction* copyDisjunction(PatternDisjunction* disjunction)
+    {
+        PatternDisjunction* newDisjunction = new PatternDisjunction();
+
+        newDisjunction->m_parent = disjunction->m_parent;
+        for (unsigned alt = 0; alt < disjunction->m_alternatives.size(); ++alt) {
+            PatternAlternative* alternative = disjunction->m_alternatives[alt];
+            PatternAlternative* newAlternative = newDisjunction->addNewAlternative();
+            for (unsigned i = 0; i < alternative->m_terms.size(); ++i)
+                newAlternative->m_terms.append(copyTerm(alternative->m_terms[i]));
+        }
+
+        m_pattern.m_disjunctions.append(newDisjunction);
+        return newDisjunction;
+    }
+
+    PatternTerm copyTerm(PatternTerm& term)
+    {
+        if ((term.type != PatternTerm::TypeParenthesesSubpattern) && (term.type != PatternTerm::TypeParentheticalAssertion))
+            return PatternTerm(term);
+
+        PatternTerm termCopy = term;
+        termCopy.parentheses.disjunction = copyDisjunction(termCopy.parentheses.disjunction);
+        return termCopy;
+    }
+
+    void quantifyAtom(unsigned min, unsigned max, bool greedy)
+    {
+        ASSERT(min <= max);
+        ASSERT(m_alternative->m_terms.size());
+
+        if (!max) {
+            m_alternative->removeLastTerm();
+            return;
+        }
+
+        PatternTerm& term = m_alternative->lastTerm();
+        ASSERT(term.type > PatternTerm::TypeAssertionWordBoundary);
+        ASSERT((term.quantityCount == 1) && (term.quantityType == QuantifierFixedCount));
+
+        // For any assertion with a zero minimum, not matching is valid and has no effect,
+        // remove it.  Otherwise, we need to match as least once, but there is no point
+        // matching more than once, so remove the quantifier.  It is not entirely clear
+        // from the spec whether or not this behavior is correct, but I believe this
+        // matches Firefox. :-/
+        if (term.type == PatternTerm::TypeParentheticalAssertion) {
+            if (!min)
+                m_alternative->removeLastTerm();
+            return;
+        }
+
+        if (min == 0)
+            term.quantify(max, greedy   ? QuantifierGreedy : QuantifierNonGreedy);
+        else if (min == max)
+            term.quantify(min, QuantifierFixedCount);
+        else {
+            term.quantify(min, QuantifierFixedCount);
+            m_alternative->m_terms.append(copyTerm(term));
+            // NOTE: this term is interesting from an analysis perspective, in that it can be ignored.....
+            m_alternative->lastTerm().quantify((max == UINT_MAX) ? max : max - min, greedy ? QuantifierGreedy : QuantifierNonGreedy);
+            if (m_alternative->lastTerm().type == PatternTerm::TypeParenthesesSubpattern)
+                m_alternative->lastTerm().parentheses.isCopy = true;
+        }
+    }
+
+    void disjunction()
+    {
+        m_alternative = m_alternative->m_parent->addNewAlternative();
+    }
+
+    void regexBegin()
+    {
+        m_pattern.m_body = new PatternDisjunction();
+        m_alternative = m_pattern.m_body->addNewAlternative();
+        m_pattern.m_disjunctions.append(m_pattern.m_body);
+    }
+    void regexEnd()
+    {
+    }
+    void regexError()
+    {
+    }
+
+    unsigned setupAlternativeOffsets(PatternAlternative* alternative, unsigned currentCallFrameSize, unsigned initialInputPosition)
+    {
+        alternative->m_hasFixedSize = true;
+        unsigned currentInputPosition = initialInputPosition;
+
+        for (unsigned i = 0; i < alternative->m_terms.size(); ++i) {
+            PatternTerm& term = alternative->m_terms[i];
+
+            switch (term.type) {
+            case PatternTerm::TypeAssertionBOL:
+            case PatternTerm::TypeAssertionEOL:
+            case PatternTerm::TypeAssertionWordBoundary:
+                term.inputPosition = currentInputPosition;
+                break;
+
+            case PatternTerm::TypeBackReference:
+                term.inputPosition = currentInputPosition;
+                term.frameLocation = currentCallFrameSize;
+                currentCallFrameSize += RegexStackSpaceForBackTrackInfoBackReference;
+                alternative->m_hasFixedSize = false;
+                break;
+
+            case PatternTerm::TypeForwardReference:
+                break;
+
+            case PatternTerm::TypePatternCharacter:
+                term.inputPosition = currentInputPosition;
+                if (term.quantityType != QuantifierFixedCount) {
+                    term.frameLocation = currentCallFrameSize;
+                    currentCallFrameSize += RegexStackSpaceForBackTrackInfoPatternCharacter;
+                    alternative->m_hasFixedSize = false;
+                } else
+                    currentInputPosition += term.quantityCount;
+                break;
+
+            case PatternTerm::TypeCharacterClass:
+                term.inputPosition = currentInputPosition;
+                if (term.quantityType != QuantifierFixedCount) {
+                    term.frameLocation = currentCallFrameSize;
+                    currentCallFrameSize += RegexStackSpaceForBackTrackInfoCharacterClass;
+                    alternative->m_hasFixedSize = false;
+                } else
+                    currentInputPosition += term.quantityCount;
+                break;
+
+            case PatternTerm::TypeParenthesesSubpattern:
+                // Note: for fixed once parentheses we will ensure at least the minimum is available; others are on their own.
+                term.frameLocation = currentCallFrameSize;
+                if ((term.quantityCount == 1) && !term.parentheses.isCopy) {
+                    if (term.quantityType == QuantifierFixedCount) {
+                        currentCallFrameSize = setupDisjunctionOffsets(term.parentheses.disjunction, currentCallFrameSize, currentInputPosition);
+                        currentInputPosition += term.parentheses.disjunction->m_minimumSize;
+                    } else {
+                        currentCallFrameSize += RegexStackSpaceForBackTrackInfoParenthesesOnce;
+                        currentCallFrameSize = setupDisjunctionOffsets(term.parentheses.disjunction, currentCallFrameSize, currentInputPosition);
+                    }
+                    term.inputPosition = currentInputPosition;
+                } else {
+                    term.inputPosition = currentInputPosition;
+                    setupDisjunctionOffsets(term.parentheses.disjunction, 0, currentInputPosition);
+                    currentCallFrameSize += RegexStackSpaceForBackTrackInfoParentheses;
+                }
+                // Fixed count of 1 could be accepted, if they have a fixed size *AND* if all alternatives are of the same length.
+                alternative->m_hasFixedSize = false;
+                break;
+
+            case PatternTerm::TypeParentheticalAssertion:
+                term.inputPosition = currentInputPosition;
+                term.frameLocation = currentCallFrameSize;
+                currentCallFrameSize = setupDisjunctionOffsets(term.parentheses.disjunction, currentCallFrameSize + RegexStackSpaceForBackTrackInfoParentheticalAssertion, currentInputPosition);
+                break;
+            }
+        }
+
+        alternative->m_minimumSize = currentInputPosition - initialInputPosition;
+        return currentCallFrameSize;
+    }
+
+    unsigned setupDisjunctionOffsets(PatternDisjunction* disjunction, unsigned initialCallFrameSize, unsigned initialInputPosition)
+    {
+        if ((disjunction != m_pattern.m_body) && (disjunction->m_alternatives.size() > 1))
+            initialCallFrameSize += RegexStackSpaceForBackTrackInfoAlternative;
+
+        unsigned minimumInputSize = UINT_MAX;
+        unsigned maximumCallFrameSize = 0;
+        bool hasFixedSize = true;
+
+        for (unsigned alt = 0; alt < disjunction->m_alternatives.size(); ++alt) {
+            PatternAlternative* alternative = disjunction->m_alternatives[alt];
+            unsigned currentAlternativeCallFrameSize = setupAlternativeOffsets(alternative, initialCallFrameSize, initialInputPosition);
+            minimumInputSize = min(minimumInputSize, alternative->m_minimumSize);
+            maximumCallFrameSize = max(maximumCallFrameSize, currentAlternativeCallFrameSize);
+            hasFixedSize &= alternative->m_hasFixedSize;
+        }
+        
+        ASSERT(minimumInputSize != UINT_MAX);
+        ASSERT(maximumCallFrameSize >= initialCallFrameSize);
+
+        disjunction->m_hasFixedSize = hasFixedSize;
+        disjunction->m_minimumSize = minimumInputSize;
+        disjunction->m_callFrameSize = maximumCallFrameSize;
+        return maximumCallFrameSize;
+    }
+
+    void setupOffsets()
+    {
+        setupDisjunctionOffsets(m_pattern.m_body, 0, 0);
+    }
+
+private:
+    RegexPattern& m_pattern;
+    PatternAlternative* m_alternative;
+    CharacterClassConstructor m_characterClassConstructor;
+    bool m_invertCharacterClass;
+};
+
+
+const char* compileRegex(const UString& patternString, RegexPattern& pattern)
+{
+    RegexPatternConstructor constructor(pattern);
+
+    if (const char* error = parse(constructor, patternString))
+        return error;
+    
+    // If the pattern contains illegal backreferences reset & reparse.
+    // Quoting Netscape's "What's new in JavaScript 1.2",
+    //      "Note: if the number of left parentheses is less than the number specified
+    //       in \#, the \# is taken as an octal escape as described in the next row."
+    if (pattern.containsIllegalBackReference()) {
+        unsigned numSubpatterns = pattern.m_numSubpatterns;
+
+        constructor.reset();
+#ifndef NDEBUG
+        const char* error =
+#endif
+            parse(constructor, patternString, numSubpatterns);
+
+        ASSERT(!error);
+        ASSERT(numSubpatterns == pattern.m_numSubpatterns);
+    }
+
+    constructor.setupOffsets();
+
+    return false;
+};
+
+
+} }
+
+#endif