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Diffstat (limited to 'src/3rdparty/masm/yarr/YarrJIT.cpp')
-rw-r--r-- | src/3rdparty/masm/yarr/YarrJIT.cpp | 2667 |
1 files changed, 2667 insertions, 0 deletions
diff --git a/src/3rdparty/masm/yarr/YarrJIT.cpp b/src/3rdparty/masm/yarr/YarrJIT.cpp new file mode 100644 index 0000000000..ce84e2c74f --- /dev/null +++ b/src/3rdparty/masm/yarr/YarrJIT.cpp @@ -0,0 +1,2667 @@ +/* + * 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 "YarrJIT.h" + +#include <wtf/ASCIICType.h> +#include "LinkBuffer.h" +#include "Options.h" +#include "Yarr.h" +#include "YarrCanonicalizeUCS2.h" + +#if ENABLE(YARR_JIT) + +using namespace WTF; + +namespace JSC { namespace Yarr { + +template<YarrJITCompileMode compileMode> +class YarrGenerator : private MacroAssembler { + friend void jitCompile(JSGlobalData*, YarrCodeBlock& jitObject, const String& pattern, unsigned& numSubpatterns, const char*& error, bool ignoreCase, bool multiline); + +#if CPU(ARM) + static const RegisterID input = ARMRegisters::r0; + static const RegisterID index = ARMRegisters::r1; + static const RegisterID length = ARMRegisters::r2; + static const RegisterID output = ARMRegisters::r4; + + static const RegisterID regT0 = ARMRegisters::r5; + static const RegisterID regT1 = ARMRegisters::r6; + + static const RegisterID returnRegister = ARMRegisters::r0; + static const RegisterID returnRegister2 = ARMRegisters::r1; +#elif CPU(MIPS) + static const RegisterID input = MIPSRegisters::a0; + static const RegisterID index = MIPSRegisters::a1; + static const RegisterID length = MIPSRegisters::a2; + static const RegisterID output = MIPSRegisters::a3; + + static const RegisterID regT0 = MIPSRegisters::t4; + static const RegisterID regT1 = MIPSRegisters::t5; + + static const RegisterID returnRegister = MIPSRegisters::v0; + static const RegisterID returnRegister2 = MIPSRegisters::v1; +#elif CPU(SH4) + static const RegisterID input = SH4Registers::r4; + static const RegisterID index = SH4Registers::r5; + static const RegisterID length = SH4Registers::r6; + static const RegisterID output = SH4Registers::r7; + + static const RegisterID regT0 = SH4Registers::r0; + static const RegisterID regT1 = SH4Registers::r1; + + static const RegisterID returnRegister = SH4Registers::r0; + static const RegisterID returnRegister2 = SH4Registers::r1; +#elif CPU(X86) + static const RegisterID input = X86Registers::eax; + static const RegisterID index = X86Registers::edx; + static const RegisterID length = X86Registers::ecx; + static const RegisterID output = X86Registers::edi; + + static const RegisterID regT0 = X86Registers::ebx; + static const RegisterID regT1 = X86Registers::esi; + + static const RegisterID returnRegister = X86Registers::eax; + static const RegisterID returnRegister2 = X86Registers::edx; +#elif CPU(X86_64) + static const RegisterID input = X86Registers::edi; + static const RegisterID index = X86Registers::esi; + static const RegisterID length = X86Registers::edx; + static const RegisterID output = X86Registers::ecx; + + static const RegisterID regT0 = X86Registers::eax; + static const RegisterID regT1 = X86Registers::ebx; + + static const RegisterID returnRegister = X86Registers::eax; + static const RegisterID returnRegister2 = X86Registers::edx; +#endif + + void optimizeAlternative(PatternAlternative* alternative) + { + if (!alternative->m_terms.size()) + return; + + for (unsigned i = 0; i < alternative->m_terms.size() - 1; ++i) { + PatternTerm& term = alternative->m_terms[i]; + PatternTerm& nextTerm = alternative->m_terms[i + 1]; + + if ((term.type == PatternTerm::TypeCharacterClass) + && (term.quantityType == QuantifierFixedCount) + && (nextTerm.type == PatternTerm::TypePatternCharacter) + && (nextTerm.quantityType == QuantifierFixedCount)) { + PatternTerm termCopy = term; + alternative->m_terms[i] = nextTerm; + alternative->m_terms[i + 1] = termCopy; + } + } + } + + void matchCharacterClassRange(RegisterID character, JumpList& failures, JumpList& matchDest, const CharacterRange* ranges, unsigned count, unsigned* matchIndex, const UChar* matches, unsigned matchCount) + { + do { + // pick which range we're going to generate + int which = count >> 1; + char lo = ranges[which].begin; + char hi = ranges[which].end; + + // check if there are any ranges or matches below lo. If not, just jl to failure - + // if there is anything else to check, check that first, if it falls through jmp to failure. + if ((*matchIndex < matchCount) && (matches[*matchIndex] < lo)) { + Jump loOrAbove = branch32(GreaterThanOrEqual, character, Imm32((unsigned short)lo)); + + // generate code for all ranges before this one + if (which) + matchCharacterClassRange(character, failures, matchDest, ranges, which, matchIndex, matches, matchCount); + + while ((*matchIndex < matchCount) && (matches[*matchIndex] < lo)) { + matchDest.append(branch32(Equal, character, Imm32((unsigned short)matches[*matchIndex]))); + ++*matchIndex; + } + failures.append(jump()); + + loOrAbove.link(this); + } else if (which) { + Jump loOrAbove = branch32(GreaterThanOrEqual, character, Imm32((unsigned short)lo)); + + matchCharacterClassRange(character, failures, matchDest, ranges, which, matchIndex, matches, matchCount); + failures.append(jump()); + + loOrAbove.link(this); + } else + failures.append(branch32(LessThan, character, Imm32((unsigned short)lo))); + + while ((*matchIndex < matchCount) && (matches[*matchIndex] <= hi)) + ++*matchIndex; + + matchDest.append(branch32(LessThanOrEqual, character, Imm32((unsigned short)hi))); + // fall through to here, the value is above hi. + + // shuffle along & loop around if there are any more matches to handle. + unsigned next = which + 1; + ranges += next; + count -= next; + } while (count); + } + + void matchCharacterClass(RegisterID character, JumpList& matchDest, const CharacterClass* charClass) + { + if (charClass->m_table) { + ExtendedAddress tableEntry(character, reinterpret_cast<intptr_t>(charClass->m_table->m_table)); + matchDest.append(branchTest8(charClass->m_table->m_inverted ? Zero : NonZero, tableEntry)); + return; + } + Jump unicodeFail; + if (charClass->m_matchesUnicode.size() || charClass->m_rangesUnicode.size()) { + Jump isAscii = branch32(LessThanOrEqual, character, TrustedImm32(0x7f)); + + if (charClass->m_matchesUnicode.size()) { + for (unsigned i = 0; i < charClass->m_matchesUnicode.size(); ++i) { + UChar ch = charClass->m_matchesUnicode[i]; + matchDest.append(branch32(Equal, character, Imm32(ch))); + } + } + + if (charClass->m_rangesUnicode.size()) { + for (unsigned i = 0; i < charClass->m_rangesUnicode.size(); ++i) { + UChar lo = charClass->m_rangesUnicode[i].begin; + UChar hi = charClass->m_rangesUnicode[i].end; + + Jump below = branch32(LessThan, character, Imm32(lo)); + matchDest.append(branch32(LessThanOrEqual, character, Imm32(hi))); + below.link(this); + } + } + + unicodeFail = jump(); + isAscii.link(this); + } + + if (charClass->m_ranges.size()) { + unsigned matchIndex = 0; + JumpList failures; + matchCharacterClassRange(character, failures, matchDest, charClass->m_ranges.begin(), charClass->m_ranges.size(), &matchIndex, charClass->m_matches.begin(), charClass->m_matches.size()); + while (matchIndex < charClass->m_matches.size()) + matchDest.append(branch32(Equal, character, Imm32((unsigned short)charClass->m_matches[matchIndex++]))); + + failures.link(this); + } else if (charClass->m_matches.size()) { + // optimization: gather 'a','A' etc back together, can mask & test once. + Vector<char> matchesAZaz; + + for (unsigned i = 0; i < charClass->m_matches.size(); ++i) { + char ch = charClass->m_matches[i]; + if (m_pattern.m_ignoreCase) { + if (isASCIILower(ch)) { + matchesAZaz.append(ch); + continue; + } + if (isASCIIUpper(ch)) + continue; + } + matchDest.append(branch32(Equal, character, Imm32((unsigned short)ch))); + } + + if (unsigned countAZaz = matchesAZaz.size()) { + or32(TrustedImm32(32), character); + for (unsigned i = 0; i < countAZaz; ++i) + matchDest.append(branch32(Equal, character, TrustedImm32(matchesAZaz[i]))); + } + } + + if (charClass->m_matchesUnicode.size() || charClass->m_rangesUnicode.size()) + unicodeFail.link(this); + } + + // Jumps if input not available; will have (incorrectly) incremented already! + Jump jumpIfNoAvailableInput(unsigned countToCheck = 0) + { + if (countToCheck) + add32(Imm32(countToCheck), index); + return branch32(Above, index, length); + } + + Jump jumpIfAvailableInput(unsigned countToCheck) + { + add32(Imm32(countToCheck), index); + return branch32(BelowOrEqual, index, length); + } + + Jump checkInput() + { + return branch32(BelowOrEqual, index, length); + } + + Jump atEndOfInput() + { + return branch32(Equal, index, length); + } + + Jump notAtEndOfInput() + { + return branch32(NotEqual, index, length); + } + + Jump jumpIfCharNotEquals(UChar ch, int inputPosition, RegisterID character) + { + readCharacter(inputPosition, character); + + // For case-insesitive compares, non-ascii characters that have different + // upper & lower case representations are converted to a character class. + ASSERT(!m_pattern.m_ignoreCase || isASCIIAlpha(ch) || isCanonicallyUnique(ch)); + if (m_pattern.m_ignoreCase && isASCIIAlpha(ch)) { + or32(TrustedImm32(0x20), character); + ch |= 0x20; + } + + return branch32(NotEqual, character, Imm32(ch)); + } + + void readCharacter(int inputPosition, RegisterID reg) + { + if (m_charSize == Char8) + load8(BaseIndex(input, index, TimesOne, inputPosition * sizeof(char)), reg); + else + load16(BaseIndex(input, index, TimesTwo, inputPosition * sizeof(UChar)), reg); + } + + void storeToFrame(RegisterID reg, unsigned frameLocation) + { + poke(reg, frameLocation); + } + + void storeToFrame(TrustedImm32 imm, unsigned frameLocation) + { + poke(imm, frameLocation); + } + + DataLabelPtr storeToFrameWithPatch(unsigned frameLocation) + { + return storePtrWithPatch(TrustedImmPtr(0), Address(stackPointerRegister, frameLocation * sizeof(void*))); + } + + void loadFromFrame(unsigned frameLocation, RegisterID reg) + { + peek(reg, frameLocation); + } + + void loadFromFrameAndJump(unsigned frameLocation) + { + jump(Address(stackPointerRegister, frameLocation * sizeof(void*))); + } + + void initCallFrame() + { + unsigned callFrameSize = m_pattern.m_body->m_callFrameSize; + if (callFrameSize) + subPtr(Imm32(callFrameSize * sizeof(void*)), stackPointerRegister); + } + void removeCallFrame() + { + unsigned callFrameSize = m_pattern.m_body->m_callFrameSize; + if (callFrameSize) + addPtr(Imm32(callFrameSize * sizeof(void*)), stackPointerRegister); + } + + // Used to record subpatters, should only be called if compileMode is IncludeSubpatterns. + void setSubpatternStart(RegisterID reg, unsigned subpattern) + { + ASSERT(subpattern); + // FIXME: should be able to ASSERT(compileMode == IncludeSubpatterns), but then this function is conditionally NORETURN. :-( + store32(reg, Address(output, (subpattern << 1) * sizeof(int))); + } + void setSubpatternEnd(RegisterID reg, unsigned subpattern) + { + ASSERT(subpattern); + // FIXME: should be able to ASSERT(compileMode == IncludeSubpatterns), but then this function is conditionally NORETURN. :-( + store32(reg, Address(output, ((subpattern << 1) + 1) * sizeof(int))); + } + void clearSubpatternStart(unsigned subpattern) + { + ASSERT(subpattern); + // FIXME: should be able to ASSERT(compileMode == IncludeSubpatterns), but then this function is conditionally NORETURN. :-( + store32(TrustedImm32(-1), Address(output, (subpattern << 1) * sizeof(int))); + } + + // We use one of three different strategies to track the start of the current match, + // while matching. + // 1) If the pattern has a fixed size, do nothing! - we calculate the value lazily + // at the end of matching. This is irrespective of compileMode, and in this case + // these methods should never be called. + // 2) If we're compiling IncludeSubpatterns, 'output' contains a pointer to an output + // vector, store the match start in the output vector. + // 3) If we're compiling MatchOnly, 'output' is unused, store the match start directly + // in this register. + void setMatchStart(RegisterID reg) + { + ASSERT(!m_pattern.m_body->m_hasFixedSize); + if (compileMode == IncludeSubpatterns) + store32(reg, output); + else + move(reg, output); + } + void getMatchStart(RegisterID reg) + { + ASSERT(!m_pattern.m_body->m_hasFixedSize); + if (compileMode == IncludeSubpatterns) + load32(output, reg); + else + move(output, reg); + } + + enum YarrOpCode { + // These nodes wrap body alternatives - those in the main disjunction, + // rather than subpatterns or assertions. These are chained together in + // a doubly linked list, with a 'begin' node for the first alternative, + // a 'next' node for each subsequent alternative, and an 'end' node at + // the end. In the case of repeating alternatives, the 'end' node also + // has a reference back to 'begin'. + OpBodyAlternativeBegin, + OpBodyAlternativeNext, + OpBodyAlternativeEnd, + // Similar to the body alternatives, but used for subpatterns with two + // or more alternatives. + OpNestedAlternativeBegin, + OpNestedAlternativeNext, + OpNestedAlternativeEnd, + // Used for alternatives in subpatterns where there is only a single + // alternative (backtrackingis easier in these cases), or for alternatives + // which never need to be backtracked (those in parenthetical assertions, + // terminal subpatterns). + OpSimpleNestedAlternativeBegin, + OpSimpleNestedAlternativeNext, + OpSimpleNestedAlternativeEnd, + // Used to wrap 'Once' subpattern matches (quantityCount == 1). + OpParenthesesSubpatternOnceBegin, + OpParenthesesSubpatternOnceEnd, + // Used to wrap 'Terminal' subpattern matches (at the end of the regexp). + OpParenthesesSubpatternTerminalBegin, + OpParenthesesSubpatternTerminalEnd, + // Used to wrap parenthetical assertions. + OpParentheticalAssertionBegin, + OpParentheticalAssertionEnd, + // Wraps all simple terms (pattern characters, character classes). + OpTerm, + // Where an expression contains only 'once through' body alternatives + // and no repeating ones, this op is used to return match failure. + OpMatchFailed + }; + + // This structure is used to hold the compiled opcode information, + // including reference back to the original PatternTerm/PatternAlternatives, + // and JIT compilation data structures. + struct YarrOp { + explicit YarrOp(PatternTerm* term) + : m_op(OpTerm) + , m_term(term) + , m_isDeadCode(false) + { + } + + explicit YarrOp(YarrOpCode op) + : m_op(op) + , m_isDeadCode(false) + { + } + + // The operation, as a YarrOpCode, and also a reference to the PatternTerm. + YarrOpCode m_op; + PatternTerm* m_term; + + // For alternatives, this holds the PatternAlternative and doubly linked + // references to this alternative's siblings. In the case of the + // OpBodyAlternativeEnd node at the end of a section of repeating nodes, + // m_nextOp will reference the OpBodyAlternativeBegin node of the first + // repeating alternative. + PatternAlternative* m_alternative; + size_t m_previousOp; + size_t m_nextOp; + + // Used to record a set of Jumps out of the generated code, typically + // used for jumps out to backtracking code, and a single reentry back + // into the code for a node (likely where a backtrack will trigger + // rematching). + Label m_reentry; + JumpList m_jumps; + + // Used for backtracking when the prior alternative did not consume any + // characters but matched. + Jump m_zeroLengthMatch; + + // This flag is used to null out the second pattern character, when + // two are fused to match a pair together. + bool m_isDeadCode; + + // Currently used in the case of some of the more complex management of + // 'm_checked', to cache the offset used in this alternative, to avoid + // recalculating it. + int m_checkAdjust; + + // Used by OpNestedAlternativeNext/End to hold the pointer to the + // value that will be pushed into the pattern's frame to return to, + // upon backtracking back into the disjunction. + DataLabelPtr m_returnAddress; + }; + + // BacktrackingState + // This class encapsulates information about the state of code generation + // whilst generating the code for backtracking, when a term fails to match. + // Upon entry to code generation of the backtracking code for a given node, + // the Backtracking state will hold references to all control flow sources + // that are outputs in need of further backtracking from the prior node + // generated (which is the subsequent operation in the regular expression, + // and in the m_ops Vector, since we generated backtracking backwards). + // These references to control flow take the form of: + // - A jump list of jumps, to be linked to code that will backtrack them + // further. + // - A set of DataLabelPtr values, to be populated with values to be + // treated effectively as return addresses backtracking into complex + // subpatterns. + // - A flag indicating that the current sequence of generated code up to + // this point requires backtracking. + class BacktrackingState { + public: + BacktrackingState() + : m_pendingFallthrough(false) + { + } + + // Add a jump or jumps, a return address, or set the flag indicating + // that the current 'fallthrough' control flow requires backtracking. + void append(const Jump& jump) + { + m_laterFailures.append(jump); + } + void append(JumpList& jumpList) + { + m_laterFailures.append(jumpList); + } + void append(const DataLabelPtr& returnAddress) + { + m_pendingReturns.append(returnAddress); + } + void fallthrough() + { + ASSERT(!m_pendingFallthrough); + m_pendingFallthrough = true; + } + + // These methods clear the backtracking state, either linking to the + // current location, a provided label, or copying the backtracking out + // to a JumpList. All actions may require code generation to take place, + // and as such are passed a pointer to the assembler. + void link(MacroAssembler* assembler) + { + if (m_pendingReturns.size()) { + Label here(assembler); + for (unsigned i = 0; i < m_pendingReturns.size(); ++i) + m_backtrackRecords.append(ReturnAddressRecord(m_pendingReturns[i], here)); + m_pendingReturns.clear(); + } + m_laterFailures.link(assembler); + m_laterFailures.clear(); + m_pendingFallthrough = false; + } + void linkTo(Label label, MacroAssembler* assembler) + { + if (m_pendingReturns.size()) { + for (unsigned i = 0; i < m_pendingReturns.size(); ++i) + m_backtrackRecords.append(ReturnAddressRecord(m_pendingReturns[i], label)); + m_pendingReturns.clear(); + } + if (m_pendingFallthrough) + assembler->jump(label); + m_laterFailures.linkTo(label, assembler); + m_laterFailures.clear(); + m_pendingFallthrough = false; + } + void takeBacktracksToJumpList(JumpList& jumpList, MacroAssembler* assembler) + { + if (m_pendingReturns.size()) { + Label here(assembler); + for (unsigned i = 0; i < m_pendingReturns.size(); ++i) + m_backtrackRecords.append(ReturnAddressRecord(m_pendingReturns[i], here)); + m_pendingReturns.clear(); + m_pendingFallthrough = true; + } + if (m_pendingFallthrough) + jumpList.append(assembler->jump()); + jumpList.append(m_laterFailures); + m_laterFailures.clear(); + m_pendingFallthrough = false; + } + + bool isEmpty() + { + return m_laterFailures.empty() && m_pendingReturns.isEmpty() && !m_pendingFallthrough; + } + + // Called at the end of code generation to link all return addresses. + void linkDataLabels(LinkBuffer& linkBuffer) + { + ASSERT(isEmpty()); + for (unsigned i = 0; i < m_backtrackRecords.size(); ++i) + linkBuffer.patch(m_backtrackRecords[i].m_dataLabel, linkBuffer.locationOf(m_backtrackRecords[i].m_backtrackLocation)); + } + + private: + struct ReturnAddressRecord { + ReturnAddressRecord(DataLabelPtr dataLabel, Label backtrackLocation) + : m_dataLabel(dataLabel) + , m_backtrackLocation(backtrackLocation) + { + } + + DataLabelPtr m_dataLabel; + Label m_backtrackLocation; + }; + + JumpList m_laterFailures; + bool m_pendingFallthrough; + Vector<DataLabelPtr, 4> m_pendingReturns; + Vector<ReturnAddressRecord, 4> m_backtrackRecords; + }; + + // Generation methods: + // =================== + + // This method provides a default implementation of backtracking common + // to many terms; terms commonly jump out of the forwards matching path + // on any failed conditions, and add these jumps to the m_jumps list. If + // no special handling is required we can often just backtrack to m_jumps. + void backtrackTermDefault(size_t opIndex) + { + YarrOp& op = m_ops[opIndex]; + m_backtrackingState.append(op.m_jumps); + } + + void generateAssertionBOL(size_t opIndex) + { + YarrOp& op = m_ops[opIndex]; + PatternTerm* term = op.m_term; + + if (m_pattern.m_multiline) { + const RegisterID character = regT0; + + JumpList matchDest; + if (!term->inputPosition) + matchDest.append(branch32(Equal, index, Imm32(m_checked))); + + readCharacter((term->inputPosition - m_checked) - 1, character); + matchCharacterClass(character, matchDest, m_pattern.newlineCharacterClass()); + op.m_jumps.append(jump()); + + matchDest.link(this); + } else { + // Erk, really should poison out these alternatives early. :-/ + if (term->inputPosition) + op.m_jumps.append(jump()); + else + op.m_jumps.append(branch32(NotEqual, index, Imm32(m_checked))); + } + } + void backtrackAssertionBOL(size_t opIndex) + { + backtrackTermDefault(opIndex); + } + + void generateAssertionEOL(size_t opIndex) + { + YarrOp& op = m_ops[opIndex]; + PatternTerm* term = op.m_term; + + if (m_pattern.m_multiline) { + const RegisterID character = regT0; + + JumpList matchDest; + if (term->inputPosition == m_checked) + matchDest.append(atEndOfInput()); + + readCharacter(term->inputPosition - m_checked, character); + matchCharacterClass(character, matchDest, m_pattern.newlineCharacterClass()); + op.m_jumps.append(jump()); + + matchDest.link(this); + } else { + if (term->inputPosition == m_checked) + op.m_jumps.append(notAtEndOfInput()); + // Erk, really should poison out these alternatives early. :-/ + else + op.m_jumps.append(jump()); + } + } + void backtrackAssertionEOL(size_t opIndex) + { + backtrackTermDefault(opIndex); + } + + // Also falls though on nextIsNotWordChar. + void matchAssertionWordchar(size_t opIndex, JumpList& nextIsWordChar, JumpList& nextIsNotWordChar) + { + YarrOp& op = m_ops[opIndex]; + PatternTerm* term = op.m_term; + + const RegisterID character = regT0; + + if (term->inputPosition == m_checked) + nextIsNotWordChar.append(atEndOfInput()); + + readCharacter((term->inputPosition - m_checked), character); + matchCharacterClass(character, nextIsWordChar, m_pattern.wordcharCharacterClass()); + } + + void generateAssertionWordBoundary(size_t opIndex) + { + YarrOp& op = m_ops[opIndex]; + PatternTerm* term = op.m_term; + + const RegisterID character = regT0; + + Jump atBegin; + JumpList matchDest; + if (!term->inputPosition) + atBegin = branch32(Equal, index, Imm32(m_checked)); + readCharacter((term->inputPosition - m_checked) - 1, character); + matchCharacterClass(character, matchDest, m_pattern.wordcharCharacterClass()); + if (!term->inputPosition) + atBegin.link(this); + + // We fall through to here if the last character was not a wordchar. + JumpList nonWordCharThenWordChar; + JumpList nonWordCharThenNonWordChar; + if (term->invert()) { + matchAssertionWordchar(opIndex, nonWordCharThenNonWordChar, nonWordCharThenWordChar); + nonWordCharThenWordChar.append(jump()); + } else { + matchAssertionWordchar(opIndex, nonWordCharThenWordChar, nonWordCharThenNonWordChar); + nonWordCharThenNonWordChar.append(jump()); + } + op.m_jumps.append(nonWordCharThenNonWordChar); + + // We jump here if the last character was a wordchar. + matchDest.link(this); + JumpList wordCharThenWordChar; + JumpList wordCharThenNonWordChar; + if (term->invert()) { + matchAssertionWordchar(opIndex, wordCharThenNonWordChar, wordCharThenWordChar); + wordCharThenWordChar.append(jump()); + } else { + matchAssertionWordchar(opIndex, wordCharThenWordChar, wordCharThenNonWordChar); + // This can fall-though! + } + + op.m_jumps.append(wordCharThenWordChar); + + nonWordCharThenWordChar.link(this); + wordCharThenNonWordChar.link(this); + } + void backtrackAssertionWordBoundary(size_t opIndex) + { + backtrackTermDefault(opIndex); + } + + void generatePatternCharacterOnce(size_t opIndex) + { + YarrOp& op = m_ops[opIndex]; + + if (op.m_isDeadCode) + return; + + // m_ops always ends with a OpBodyAlternativeEnd or OpMatchFailed + // node, so there must always be at least one more node. + ASSERT(opIndex + 1 < m_ops.size()); + YarrOp* nextOp = &m_ops[opIndex + 1]; + + PatternTerm* term = op.m_term; + UChar ch = term->patternCharacter; + + if ((ch > 0xff) && (m_charSize == Char8)) { + // Have a 16 bit pattern character and an 8 bit string - short circuit + op.m_jumps.append(jump()); + return; + } + + const RegisterID character = regT0; + int maxCharactersAtOnce = m_charSize == Char8 ? 4 : 2; + unsigned ignoreCaseMask = 0; + int allCharacters = ch; + int numberCharacters; + int startTermPosition = term->inputPosition; + + // For case-insesitive compares, non-ascii characters that have different + // upper & lower case representations are converted to a character class. + ASSERT(!m_pattern.m_ignoreCase || isASCIIAlpha(ch) || isCanonicallyUnique(ch)); + + if (m_pattern.m_ignoreCase && isASCIIAlpha(ch)) + ignoreCaseMask |= 32; + + for (numberCharacters = 1; numberCharacters < maxCharactersAtOnce && nextOp->m_op == OpTerm; ++numberCharacters, nextOp = &m_ops[opIndex + numberCharacters]) { + PatternTerm* nextTerm = nextOp->m_term; + + if (nextTerm->type != PatternTerm::TypePatternCharacter + || nextTerm->quantityType != QuantifierFixedCount + || nextTerm->quantityCount != 1 + || nextTerm->inputPosition != (startTermPosition + numberCharacters)) + break; + + nextOp->m_isDeadCode = true; + + int shiftAmount = (m_charSize == Char8 ? 8 : 16) * numberCharacters; + + UChar currentCharacter = nextTerm->patternCharacter; + + if ((currentCharacter > 0xff) && (m_charSize == Char8)) { + // Have a 16 bit pattern character and an 8 bit string - short circuit + op.m_jumps.append(jump()); + return; + } + + // For case-insesitive compares, non-ascii characters that have different + // upper & lower case representations are converted to a character class. + ASSERT(!m_pattern.m_ignoreCase || isASCIIAlpha(currentCharacter) || isCanonicallyUnique(currentCharacter)); + + allCharacters |= (currentCharacter << shiftAmount); + + if ((m_pattern.m_ignoreCase) && (isASCIIAlpha(currentCharacter))) + ignoreCaseMask |= 32 << shiftAmount; + } + + if (m_charSize == Char8) { + switch (numberCharacters) { + case 1: + op.m_jumps.append(jumpIfCharNotEquals(ch, startTermPosition - m_checked, character)); + return; + case 2: { + BaseIndex address(input, index, TimesOne, (startTermPosition - m_checked) * sizeof(LChar)); + load16Unaligned(address, character); + break; + } + case 3: { + BaseIndex highAddress(input, index, TimesOne, (startTermPosition - m_checked) * sizeof(LChar)); + load16Unaligned(highAddress, character); + if (ignoreCaseMask) + or32(Imm32(ignoreCaseMask), character); + op.m_jumps.append(branch32(NotEqual, character, Imm32((allCharacters & 0xffff) | ignoreCaseMask))); + op.m_jumps.append(jumpIfCharNotEquals(allCharacters >> 16, startTermPosition + 2 - m_checked, character)); + return; + } + case 4: { + BaseIndex address(input, index, TimesOne, (startTermPosition - m_checked) * sizeof(LChar)); + load32WithUnalignedHalfWords(address, character); + break; + } + } + } else { + switch (numberCharacters) { + case 1: + op.m_jumps.append(jumpIfCharNotEquals(ch, term->inputPosition - m_checked, character)); + return; + case 2: + BaseIndex address(input, index, TimesTwo, (term->inputPosition - m_checked) * sizeof(UChar)); + load32WithUnalignedHalfWords(address, character); + break; + } + } + + if (ignoreCaseMask) + or32(Imm32(ignoreCaseMask), character); + op.m_jumps.append(branch32(NotEqual, character, Imm32(allCharacters | ignoreCaseMask))); + return; + } + void backtrackPatternCharacterOnce(size_t opIndex) + { + backtrackTermDefault(opIndex); + } + + void generatePatternCharacterFixed(size_t opIndex) + { + YarrOp& op = m_ops[opIndex]; + PatternTerm* term = op.m_term; + UChar ch = term->patternCharacter; + + const RegisterID character = regT0; + const RegisterID countRegister = regT1; + + move(index, countRegister); + sub32(Imm32(term->quantityCount.unsafeGet()), countRegister); + + Label loop(this); + BaseIndex address(input, countRegister, m_charScale, (Checked<int>(term->inputPosition - m_checked + Checked<int64_t>(term->quantityCount)) * static_cast<int>(m_charSize == Char8 ? sizeof(char) : sizeof(UChar))).unsafeGet()); + + if (m_charSize == Char8) + load8(address, character); + else + load16(address, character); + + // For case-insesitive compares, non-ascii characters that have different + // upper & lower case representations are converted to a character class. + ASSERT(!m_pattern.m_ignoreCase || isASCIIAlpha(ch) || isCanonicallyUnique(ch)); + if (m_pattern.m_ignoreCase && isASCIIAlpha(ch)) { + or32(TrustedImm32(0x20), character); + ch |= 0x20; + } + + op.m_jumps.append(branch32(NotEqual, character, Imm32(ch))); + add32(TrustedImm32(1), countRegister); + branch32(NotEqual, countRegister, index).linkTo(loop, this); + } + void backtrackPatternCharacterFixed(size_t opIndex) + { + backtrackTermDefault(opIndex); + } + + void generatePatternCharacterGreedy(size_t opIndex) + { + YarrOp& op = m_ops[opIndex]; + PatternTerm* term = op.m_term; + UChar ch = term->patternCharacter; + + const RegisterID character = regT0; + const RegisterID countRegister = regT1; + + move(TrustedImm32(0), countRegister); + + // Unless have a 16 bit pattern character and an 8 bit string - short circuit + if (!((ch > 0xff) && (m_charSize == Char8))) { + JumpList failures; + Label loop(this); + failures.append(atEndOfInput()); + failures.append(jumpIfCharNotEquals(ch, term->inputPosition - m_checked, character)); + + add32(TrustedImm32(1), countRegister); + add32(TrustedImm32(1), index); + if (term->quantityCount == quantifyInfinite) + jump(loop); + else + branch32(NotEqual, countRegister, Imm32(term->quantityCount.unsafeGet())).linkTo(loop, this); + + failures.link(this); + } + op.m_reentry = label(); + + storeToFrame(countRegister, term->frameLocation); + } + void backtrackPatternCharacterGreedy(size_t opIndex) + { + YarrOp& op = m_ops[opIndex]; + PatternTerm* term = op.m_term; + + const RegisterID countRegister = regT1; + + m_backtrackingState.link(this); + + loadFromFrame(term->frameLocation, countRegister); + m_backtrackingState.append(branchTest32(Zero, countRegister)); + sub32(TrustedImm32(1), countRegister); + sub32(TrustedImm32(1), index); + jump(op.m_reentry); + } + + void generatePatternCharacterNonGreedy(size_t opIndex) + { + YarrOp& op = m_ops[opIndex]; + PatternTerm* term = op.m_term; + + const RegisterID countRegister = regT1; + + move(TrustedImm32(0), countRegister); + op.m_reentry = label(); + storeToFrame(countRegister, term->frameLocation); + } + void backtrackPatternCharacterNonGreedy(size_t opIndex) + { + YarrOp& op = m_ops[opIndex]; + PatternTerm* term = op.m_term; + UChar ch = term->patternCharacter; + + const RegisterID character = regT0; + const RegisterID countRegister = regT1; + + m_backtrackingState.link(this); + + loadFromFrame(term->frameLocation, countRegister); + + // Unless have a 16 bit pattern character and an 8 bit string - short circuit + if (!((ch > 0xff) && (m_charSize == Char8))) { + JumpList nonGreedyFailures; + nonGreedyFailures.append(atEndOfInput()); + if (term->quantityCount != quantifyInfinite) + nonGreedyFailures.append(branch32(Equal, countRegister, Imm32(term->quantityCount.unsafeGet()))); + nonGreedyFailures.append(jumpIfCharNotEquals(ch, term->inputPosition - m_checked, character)); + + add32(TrustedImm32(1), countRegister); + add32(TrustedImm32(1), index); + + jump(op.m_reentry); + nonGreedyFailures.link(this); + } + + sub32(countRegister, index); + m_backtrackingState.fallthrough(); + } + + void generateCharacterClassOnce(size_t opIndex) + { + YarrOp& op = m_ops[opIndex]; + PatternTerm* term = op.m_term; + + const RegisterID character = regT0; + + JumpList matchDest; + readCharacter(term->inputPosition - m_checked, character); + matchCharacterClass(character, matchDest, term->characterClass); + + if (term->invert()) + op.m_jumps.append(matchDest); + else { + op.m_jumps.append(jump()); + matchDest.link(this); + } + } + void backtrackCharacterClassOnce(size_t opIndex) + { + backtrackTermDefault(opIndex); + } + + void generateCharacterClassFixed(size_t opIndex) + { + YarrOp& op = m_ops[opIndex]; + PatternTerm* term = op.m_term; + + const RegisterID character = regT0; + const RegisterID countRegister = regT1; + + move(index, countRegister); + sub32(Imm32(term->quantityCount.unsafeGet()), countRegister); + + Label loop(this); + JumpList matchDest; + if (m_charSize == Char8) + load8(BaseIndex(input, countRegister, TimesOne, (Checked<int>(term->inputPosition - m_checked + Checked<int64_t>(term->quantityCount)) * static_cast<int>(sizeof(char))).unsafeGet()), character); + else + load16(BaseIndex(input, countRegister, TimesTwo, (Checked<int>(term->inputPosition - m_checked + Checked<int64_t>(term->quantityCount)) * static_cast<int>(sizeof(UChar))).unsafeGet()), character); + matchCharacterClass(character, matchDest, term->characterClass); + + if (term->invert()) + op.m_jumps.append(matchDest); + else { + op.m_jumps.append(jump()); + matchDest.link(this); + } + + add32(TrustedImm32(1), countRegister); + branch32(NotEqual, countRegister, index).linkTo(loop, this); + } + void backtrackCharacterClassFixed(size_t opIndex) + { + backtrackTermDefault(opIndex); + } + + void generateCharacterClassGreedy(size_t opIndex) + { + YarrOp& op = m_ops[opIndex]; + PatternTerm* term = op.m_term; + + const RegisterID character = regT0; + const RegisterID countRegister = regT1; + + move(TrustedImm32(0), countRegister); + + JumpList failures; + Label loop(this); + failures.append(atEndOfInput()); + + if (term->invert()) { + readCharacter(term->inputPosition - m_checked, character); + matchCharacterClass(character, failures, term->characterClass); + } else { + JumpList matchDest; + readCharacter(term->inputPosition - m_checked, character); + matchCharacterClass(character, matchDest, term->characterClass); + failures.append(jump()); + matchDest.link(this); + } + + add32(TrustedImm32(1), countRegister); + add32(TrustedImm32(1), index); + if (term->quantityCount != quantifyInfinite) { + branch32(NotEqual, countRegister, Imm32(term->quantityCount.unsafeGet())).linkTo(loop, this); + failures.append(jump()); + } else + jump(loop); + + failures.link(this); + op.m_reentry = label(); + + storeToFrame(countRegister, term->frameLocation); + } + void backtrackCharacterClassGreedy(size_t opIndex) + { + YarrOp& op = m_ops[opIndex]; + PatternTerm* term = op.m_term; + + const RegisterID countRegister = regT1; + + m_backtrackingState.link(this); + + loadFromFrame(term->frameLocation, countRegister); + m_backtrackingState.append(branchTest32(Zero, countRegister)); + sub32(TrustedImm32(1), countRegister); + sub32(TrustedImm32(1), index); + jump(op.m_reentry); + } + + void generateCharacterClassNonGreedy(size_t opIndex) + { + YarrOp& op = m_ops[opIndex]; + PatternTerm* term = op.m_term; + + const RegisterID countRegister = regT1; + + move(TrustedImm32(0), countRegister); + op.m_reentry = label(); + storeToFrame(countRegister, term->frameLocation); + } + void backtrackCharacterClassNonGreedy(size_t opIndex) + { + YarrOp& op = m_ops[opIndex]; + PatternTerm* term = op.m_term; + + const RegisterID character = regT0; + const RegisterID countRegister = regT1; + + JumpList nonGreedyFailures; + + m_backtrackingState.link(this); + + loadFromFrame(term->frameLocation, countRegister); + + nonGreedyFailures.append(atEndOfInput()); + nonGreedyFailures.append(branch32(Equal, countRegister, Imm32(term->quantityCount.unsafeGet()))); + + JumpList matchDest; + readCharacter(term->inputPosition - m_checked, character); + matchCharacterClass(character, matchDest, term->characterClass); + + if (term->invert()) + nonGreedyFailures.append(matchDest); + else { + nonGreedyFailures.append(jump()); + matchDest.link(this); + } + + add32(TrustedImm32(1), countRegister); + add32(TrustedImm32(1), index); + + jump(op.m_reentry); + + nonGreedyFailures.link(this); + sub32(countRegister, index); + m_backtrackingState.fallthrough(); + } + + void generateDotStarEnclosure(size_t opIndex) + { + YarrOp& op = m_ops[opIndex]; + PatternTerm* term = op.m_term; + + const RegisterID character = regT0; + const RegisterID matchPos = regT1; + + JumpList foundBeginningNewLine; + JumpList saveStartIndex; + JumpList foundEndingNewLine; + + ASSERT(!m_pattern.m_body->m_hasFixedSize); + getMatchStart(matchPos); + + saveStartIndex.append(branchTest32(Zero, matchPos)); + Label findBOLLoop(this); + sub32(TrustedImm32(1), matchPos); + if (m_charSize == Char8) + load8(BaseIndex(input, matchPos, TimesOne, 0), character); + else + load16(BaseIndex(input, matchPos, TimesTwo, 0), character); + matchCharacterClass(character, foundBeginningNewLine, m_pattern.newlineCharacterClass()); + branchTest32(NonZero, matchPos).linkTo(findBOLLoop, this); + saveStartIndex.append(jump()); + + foundBeginningNewLine.link(this); + add32(TrustedImm32(1), matchPos); // Advance past newline + saveStartIndex.link(this); + + if (!m_pattern.m_multiline && term->anchors.bolAnchor) + op.m_jumps.append(branchTest32(NonZero, matchPos)); + + ASSERT(!m_pattern.m_body->m_hasFixedSize); + setMatchStart(matchPos); + + move(index, matchPos); + + Label findEOLLoop(this); + foundEndingNewLine.append(branch32(Equal, matchPos, length)); + if (m_charSize == Char8) + load8(BaseIndex(input, matchPos, TimesOne, 0), character); + else + load16(BaseIndex(input, matchPos, TimesTwo, 0), character); + matchCharacterClass(character, foundEndingNewLine, m_pattern.newlineCharacterClass()); + add32(TrustedImm32(1), matchPos); + jump(findEOLLoop); + + foundEndingNewLine.link(this); + + if (!m_pattern.m_multiline && term->anchors.eolAnchor) + op.m_jumps.append(branch32(NotEqual, matchPos, length)); + + move(matchPos, index); + } + + void backtrackDotStarEnclosure(size_t opIndex) + { + backtrackTermDefault(opIndex); + } + + // Code generation/backtracking for simple terms + // (pattern characters, character classes, and assertions). + // These methods farm out work to the set of functions above. + void generateTerm(size_t opIndex) + { + YarrOp& op = m_ops[opIndex]; + PatternTerm* term = op.m_term; + + switch (term->type) { + case PatternTerm::TypePatternCharacter: + switch (term->quantityType) { + case QuantifierFixedCount: + if (term->quantityCount == 1) + generatePatternCharacterOnce(opIndex); + else + generatePatternCharacterFixed(opIndex); + break; + case QuantifierGreedy: + generatePatternCharacterGreedy(opIndex); + break; + case QuantifierNonGreedy: + generatePatternCharacterNonGreedy(opIndex); + break; + } + break; + + case PatternTerm::TypeCharacterClass: + switch (term->quantityType) { + case QuantifierFixedCount: + if (term->quantityCount == 1) + generateCharacterClassOnce(opIndex); + else + generateCharacterClassFixed(opIndex); + break; + case QuantifierGreedy: + generateCharacterClassGreedy(opIndex); + break; + case QuantifierNonGreedy: + generateCharacterClassNonGreedy(opIndex); + break; + } + break; + + case PatternTerm::TypeAssertionBOL: + generateAssertionBOL(opIndex); + break; + + case PatternTerm::TypeAssertionEOL: + generateAssertionEOL(opIndex); + break; + + case PatternTerm::TypeAssertionWordBoundary: + generateAssertionWordBoundary(opIndex); + break; + + case PatternTerm::TypeForwardReference: + break; + + case PatternTerm::TypeParenthesesSubpattern: + case PatternTerm::TypeParentheticalAssertion: + ASSERT_NOT_REACHED(); + case PatternTerm::TypeBackReference: + m_shouldFallBack = true; + break; + case PatternTerm::TypeDotStarEnclosure: + generateDotStarEnclosure(opIndex); + break; + } + } + void backtrackTerm(size_t opIndex) + { + YarrOp& op = m_ops[opIndex]; + PatternTerm* term = op.m_term; + + switch (term->type) { + case PatternTerm::TypePatternCharacter: + switch (term->quantityType) { + case QuantifierFixedCount: + if (term->quantityCount == 1) + backtrackPatternCharacterOnce(opIndex); + else + backtrackPatternCharacterFixed(opIndex); + break; + case QuantifierGreedy: + backtrackPatternCharacterGreedy(opIndex); + break; + case QuantifierNonGreedy: + backtrackPatternCharacterNonGreedy(opIndex); + break; + } + break; + + case PatternTerm::TypeCharacterClass: + switch (term->quantityType) { + case QuantifierFixedCount: + if (term->quantityCount == 1) + backtrackCharacterClassOnce(opIndex); + else + backtrackCharacterClassFixed(opIndex); + break; + case QuantifierGreedy: + backtrackCharacterClassGreedy(opIndex); + break; + case QuantifierNonGreedy: + backtrackCharacterClassNonGreedy(opIndex); + break; + } + break; + + case PatternTerm::TypeAssertionBOL: + backtrackAssertionBOL(opIndex); + break; + + case PatternTerm::TypeAssertionEOL: + backtrackAssertionEOL(opIndex); + break; + + case PatternTerm::TypeAssertionWordBoundary: + backtrackAssertionWordBoundary(opIndex); + break; + + case PatternTerm::TypeForwardReference: + break; + + case PatternTerm::TypeParenthesesSubpattern: + case PatternTerm::TypeParentheticalAssertion: + ASSERT_NOT_REACHED(); + + case PatternTerm::TypeDotStarEnclosure: + backtrackDotStarEnclosure(opIndex); + break; + + case PatternTerm::TypeBackReference: + m_shouldFallBack = true; + break; + } + } + + void generate() + { + // Forwards generate the matching code. + ASSERT(m_ops.size()); + size_t opIndex = 0; + + do { + YarrOp& op = m_ops[opIndex]; + switch (op.m_op) { + + case OpTerm: + generateTerm(opIndex); + break; + + // OpBodyAlternativeBegin/Next/End + // + // These nodes wrap the set of alternatives in the body of the regular expression. + // There may be either one or two chains of OpBodyAlternative nodes, one representing + // the 'once through' sequence of alternatives (if any exist), and one representing + // the repeating alternatives (again, if any exist). + // + // Upon normal entry to the Begin alternative, we will check that input is available. + // Reentry to the Begin alternative will take place after the check has taken place, + // and will assume that the input position has already been progressed as appropriate. + // + // Entry to subsequent Next/End alternatives occurs when the prior alternative has + // successfully completed a match - return a success state from JIT code. + // + // Next alternatives allow for reentry optimized to suit backtracking from its + // preceding alternative. It expects the input position to still be set to a position + // appropriate to its predecessor, and it will only perform an input check if the + // predecessor had a minimum size less than its own. + // + // In the case 'once through' expressions, the End node will also have a reentry + // point to jump to when the last alternative fails. Again, this expects the input + // position to still reflect that expected by the prior alternative. + case OpBodyAlternativeBegin: { + PatternAlternative* alternative = op.m_alternative; + + // Upon entry at the head of the set of alternatives, check if input is available + // to run the first alternative. (This progresses the input position). + op.m_jumps.append(jumpIfNoAvailableInput(alternative->m_minimumSize)); + // We will reenter after the check, and assume the input position to have been + // set as appropriate to this alternative. + op.m_reentry = label(); + + m_checked += alternative->m_minimumSize; + break; + } + case OpBodyAlternativeNext: + case OpBodyAlternativeEnd: { + PatternAlternative* priorAlternative = m_ops[op.m_previousOp].m_alternative; + PatternAlternative* alternative = op.m_alternative; + + // If we get here, the prior alternative matched - return success. + + // Adjust the stack pointer to remove the pattern's frame. + removeCallFrame(); + + // Load appropriate values into the return register and the first output + // slot, and return. In the case of pattern with a fixed size, we will + // not have yet set the value in the first + ASSERT(index != returnRegister); + if (m_pattern.m_body->m_hasFixedSize) { + move(index, returnRegister); + if (priorAlternative->m_minimumSize) + sub32(Imm32(priorAlternative->m_minimumSize), returnRegister); + if (compileMode == IncludeSubpatterns) + store32(returnRegister, output); + } else + getMatchStart(returnRegister); + if (compileMode == IncludeSubpatterns) + store32(index, Address(output, 4)); + move(index, returnRegister2); + + generateReturn(); + + // This is the divide between the tail of the prior alternative, above, and + // the head of the subsequent alternative, below. + + if (op.m_op == OpBodyAlternativeNext) { + // This is the reentry point for the Next alternative. We expect any code + // that jumps here to do so with the input position matching that of the + // PRIOR alteranative, and we will only check input availability if we + // need to progress it forwards. + op.m_reentry = label(); + if (alternative->m_minimumSize > priorAlternative->m_minimumSize) { + add32(Imm32(alternative->m_minimumSize - priorAlternative->m_minimumSize), index); + op.m_jumps.append(jumpIfNoAvailableInput()); + } else if (priorAlternative->m_minimumSize > alternative->m_minimumSize) + sub32(Imm32(priorAlternative->m_minimumSize - alternative->m_minimumSize), index); + } else if (op.m_nextOp == notFound) { + // This is the reentry point for the End of 'once through' alternatives, + // jumped to when the last alternative fails to match. + op.m_reentry = label(); + sub32(Imm32(priorAlternative->m_minimumSize), index); + } + + if (op.m_op == OpBodyAlternativeNext) + m_checked += alternative->m_minimumSize; + m_checked -= priorAlternative->m_minimumSize; + break; + } + + // OpSimpleNestedAlternativeBegin/Next/End + // OpNestedAlternativeBegin/Next/End + // + // These nodes are used to handle sets of alternatives that are nested within + // subpatterns and parenthetical assertions. The 'simple' forms are used where + // we do not need to be able to backtrack back into any alternative other than + // the last, the normal forms allow backtracking into any alternative. + // + // Each Begin/Next node is responsible for planting an input check to ensure + // sufficient input is available on entry. Next nodes additionally need to + // jump to the end - Next nodes use the End node's m_jumps list to hold this + // set of jumps. + // + // In the non-simple forms, successful alternative matches must store a + // 'return address' using a DataLabelPtr, used to store the address to jump + // to when backtracking, to get to the code for the appropriate alternative. + case OpSimpleNestedAlternativeBegin: + case OpNestedAlternativeBegin: { + PatternTerm* term = op.m_term; + PatternAlternative* alternative = op.m_alternative; + PatternDisjunction* disjunction = term->parentheses.disjunction; + + // Calculate how much input we need to check for, and if non-zero check. + op.m_checkAdjust = alternative->m_minimumSize; + if ((term->quantityType == QuantifierFixedCount) && (term->type != PatternTerm::TypeParentheticalAssertion)) + op.m_checkAdjust -= disjunction->m_minimumSize; + if (op.m_checkAdjust) + op.m_jumps.append(jumpIfNoAvailableInput(op.m_checkAdjust)); + + m_checked += op.m_checkAdjust; + break; + } + case OpSimpleNestedAlternativeNext: + case OpNestedAlternativeNext: { + PatternTerm* term = op.m_term; + PatternAlternative* alternative = op.m_alternative; + PatternDisjunction* disjunction = term->parentheses.disjunction; + + // In the non-simple case, store a 'return address' so we can backtrack correctly. + if (op.m_op == OpNestedAlternativeNext) { + unsigned parenthesesFrameLocation = term->frameLocation; + unsigned alternativeFrameLocation = parenthesesFrameLocation; + if (term->quantityType != QuantifierFixedCount) + alternativeFrameLocation += YarrStackSpaceForBackTrackInfoParenthesesOnce; + op.m_returnAddress = storeToFrameWithPatch(alternativeFrameLocation); + } + + if (term->quantityType != QuantifierFixedCount && !m_ops[op.m_previousOp].m_alternative->m_minimumSize) { + // If the previous alternative matched without consuming characters then + // backtrack to try to match while consumming some input. + op.m_zeroLengthMatch = branch32(Equal, index, Address(stackPointerRegister, term->frameLocation * sizeof(void*))); + } + + // If we reach here then the last alternative has matched - jump to the + // End node, to skip over any further alternatives. + // + // FIXME: this is logically O(N^2) (though N can be expected to be very + // small). We could avoid this either by adding an extra jump to the JIT + // data structures, or by making backtracking code that jumps to Next + // alternatives are responsible for checking that input is available (if + // we didn't need to plant the input checks, then m_jumps would be free). + YarrOp* endOp = &m_ops[op.m_nextOp]; + while (endOp->m_nextOp != notFound) { + ASSERT(endOp->m_op == OpSimpleNestedAlternativeNext || endOp->m_op == OpNestedAlternativeNext); + endOp = &m_ops[endOp->m_nextOp]; + } + ASSERT(endOp->m_op == OpSimpleNestedAlternativeEnd || endOp->m_op == OpNestedAlternativeEnd); + endOp->m_jumps.append(jump()); + + // This is the entry point for the next alternative. + op.m_reentry = label(); + + // Calculate how much input we need to check for, and if non-zero check. + op.m_checkAdjust = alternative->m_minimumSize; + if ((term->quantityType == QuantifierFixedCount) && (term->type != PatternTerm::TypeParentheticalAssertion)) + op.m_checkAdjust -= disjunction->m_minimumSize; + if (op.m_checkAdjust) + op.m_jumps.append(jumpIfNoAvailableInput(op.m_checkAdjust)); + + YarrOp& lastOp = m_ops[op.m_previousOp]; + m_checked -= lastOp.m_checkAdjust; + m_checked += op.m_checkAdjust; + break; + } + case OpSimpleNestedAlternativeEnd: + case OpNestedAlternativeEnd: { + PatternTerm* term = op.m_term; + + // In the non-simple case, store a 'return address' so we can backtrack correctly. + if (op.m_op == OpNestedAlternativeEnd) { + unsigned parenthesesFrameLocation = term->frameLocation; + unsigned alternativeFrameLocation = parenthesesFrameLocation; + if (term->quantityType != QuantifierFixedCount) + alternativeFrameLocation += YarrStackSpaceForBackTrackInfoParenthesesOnce; + op.m_returnAddress = storeToFrameWithPatch(alternativeFrameLocation); + } + + if (term->quantityType != QuantifierFixedCount && !m_ops[op.m_previousOp].m_alternative->m_minimumSize) { + // If the previous alternative matched without consuming characters then + // backtrack to try to match while consumming some input. + op.m_zeroLengthMatch = branch32(Equal, index, Address(stackPointerRegister, term->frameLocation * sizeof(void*))); + } + + // If this set of alternatives contains more than one alternative, + // then the Next nodes will have planted jumps to the End, and added + // them to this node's m_jumps list. + op.m_jumps.link(this); + op.m_jumps.clear(); + + YarrOp& lastOp = m_ops[op.m_previousOp]; + m_checked -= lastOp.m_checkAdjust; + break; + } + + // OpParenthesesSubpatternOnceBegin/End + // + // These nodes support (optionally) capturing subpatterns, that have a + // quantity count of 1 (this covers fixed once, and ?/?? quantifiers). + case OpParenthesesSubpatternOnceBegin: { + PatternTerm* term = op.m_term; + unsigned parenthesesFrameLocation = term->frameLocation; + const RegisterID indexTemporary = regT0; + ASSERT(term->quantityCount == 1); + + // Upon entry to a Greedy quantified set of parenthese store the index. + // We'll use this for two purposes: + // - To indicate which iteration we are on of mathing the remainder of + // the expression after the parentheses - the first, including the + // match within the parentheses, or the second having skipped over them. + // - To check for empty matches, which must be rejected. + // + // At the head of a NonGreedy set of parentheses we'll immediately set the + // value on the stack to -1 (indicating a match skipping the subpattern), + // and plant a jump to the end. We'll also plant a label to backtrack to + // to reenter the subpattern later, with a store to set up index on the + // second iteration. + // + // FIXME: for capturing parens, could use the index in the capture array? + if (term->quantityType == QuantifierGreedy) + storeToFrame(index, parenthesesFrameLocation); + else if (term->quantityType == QuantifierNonGreedy) { + storeToFrame(TrustedImm32(-1), parenthesesFrameLocation); + op.m_jumps.append(jump()); + op.m_reentry = label(); + storeToFrame(index, parenthesesFrameLocation); + } + + // If the parenthese are capturing, store the starting index value to the + // captures array, offsetting as necessary. + // + // FIXME: could avoid offsetting this value in JIT code, apply + // offsets only afterwards, at the point the results array is + // being accessed. + if (term->capture() && compileMode == IncludeSubpatterns) { + int inputOffset = term->inputPosition - m_checked; + if (term->quantityType == QuantifierFixedCount) + inputOffset -= term->parentheses.disjunction->m_minimumSize; + if (inputOffset) { + move(index, indexTemporary); + add32(Imm32(inputOffset), indexTemporary); + setSubpatternStart(indexTemporary, term->parentheses.subpatternId); + } else + setSubpatternStart(index, term->parentheses.subpatternId); + } + break; + } + case OpParenthesesSubpatternOnceEnd: { + PatternTerm* term = op.m_term; + const RegisterID indexTemporary = regT0; + ASSERT(term->quantityCount == 1); + +#ifndef NDEBUG + // Runtime ASSERT to make sure that the nested alternative handled the + // "no input consumed" check. + if (term->quantityType != QuantifierFixedCount && !term->parentheses.disjunction->m_minimumSize) { + Jump pastBreakpoint; + pastBreakpoint = branch32(NotEqual, index, Address(stackPointerRegister, term->frameLocation * sizeof(void*))); + breakpoint(); + pastBreakpoint.link(this); + } +#endif + + // If the parenthese are capturing, store the ending index value to the + // captures array, offsetting as necessary. + // + // FIXME: could avoid offsetting this value in JIT code, apply + // offsets only afterwards, at the point the results array is + // being accessed. + if (term->capture() && compileMode == IncludeSubpatterns) { + int inputOffset = term->inputPosition - m_checked; + if (inputOffset) { + move(index, indexTemporary); + add32(Imm32(inputOffset), indexTemporary); + setSubpatternEnd(indexTemporary, term->parentheses.subpatternId); + } else + setSubpatternEnd(index, term->parentheses.subpatternId); + } + + // If the parentheses are quantified Greedy then add a label to jump back + // to if get a failed match from after the parentheses. For NonGreedy + // parentheses, link the jump from before the subpattern to here. + if (term->quantityType == QuantifierGreedy) + op.m_reentry = label(); + else if (term->quantityType == QuantifierNonGreedy) { + YarrOp& beginOp = m_ops[op.m_previousOp]; + beginOp.m_jumps.link(this); + } + break; + } + + // OpParenthesesSubpatternTerminalBegin/End + case OpParenthesesSubpatternTerminalBegin: { + PatternTerm* term = op.m_term; + ASSERT(term->quantityType == QuantifierGreedy); + ASSERT(term->quantityCount == quantifyInfinite); + ASSERT(!term->capture()); + + // Upon entry set a label to loop back to. + op.m_reentry = label(); + + // Store the start index of the current match; we need to reject zero + // length matches. + storeToFrame(index, term->frameLocation); + break; + } + case OpParenthesesSubpatternTerminalEnd: { + YarrOp& beginOp = m_ops[op.m_previousOp]; +#ifndef NDEBUG + PatternTerm* term = op.m_term; + + // Runtime ASSERT to make sure that the nested alternative handled the + // "no input consumed" check. + Jump pastBreakpoint; + pastBreakpoint = branch32(NotEqual, index, Address(stackPointerRegister, term->frameLocation * sizeof(void*))); + breakpoint(); + pastBreakpoint.link(this); +#endif + + // We know that the match is non-zero, we can accept it and + // loop back up to the head of the subpattern. + jump(beginOp.m_reentry); + + // This is the entry point to jump to when we stop matching - we will + // do so once the subpattern cannot match any more. + op.m_reentry = label(); + break; + } + + // OpParentheticalAssertionBegin/End + case OpParentheticalAssertionBegin: { + PatternTerm* term = op.m_term; + + // Store the current index - assertions should not update index, so + // we will need to restore it upon a successful match. + unsigned parenthesesFrameLocation = term->frameLocation; + storeToFrame(index, parenthesesFrameLocation); + + // Check + op.m_checkAdjust = m_checked - term->inputPosition; + if (op.m_checkAdjust) + sub32(Imm32(op.m_checkAdjust), index); + + m_checked -= op.m_checkAdjust; + break; + } + case OpParentheticalAssertionEnd: { + PatternTerm* term = op.m_term; + + // Restore the input index value. + unsigned parenthesesFrameLocation = term->frameLocation; + loadFromFrame(parenthesesFrameLocation, index); + + // If inverted, a successful match of the assertion must be treated + // as a failure, so jump to backtracking. + if (term->invert()) { + op.m_jumps.append(jump()); + op.m_reentry = label(); + } + + YarrOp& lastOp = m_ops[op.m_previousOp]; + m_checked += lastOp.m_checkAdjust; + break; + } + + case OpMatchFailed: + removeCallFrame(); + move(TrustedImmPtr((void*)WTF::notFound), returnRegister); + move(TrustedImm32(0), returnRegister2); + generateReturn(); + break; + } + + ++opIndex; + } while (opIndex < m_ops.size()); + } + + void backtrack() + { + // Backwards generate the backtracking code. + size_t opIndex = m_ops.size(); + ASSERT(opIndex); + + do { + --opIndex; + YarrOp& op = m_ops[opIndex]; + switch (op.m_op) { + + case OpTerm: + backtrackTerm(opIndex); + break; + + // OpBodyAlternativeBegin/Next/End + // + // For each Begin/Next node representing an alternative, we need to decide what to do + // in two circumstances: + // - If we backtrack back into this node, from within the alternative. + // - If the input check at the head of the alternative fails (if this exists). + // + // We treat these two cases differently since in the former case we have slightly + // more information - since we are backtracking out of a prior alternative we know + // that at least enough input was available to run it. For example, given the regular + // expression /a|b/, if we backtrack out of the first alternative (a failed pattern + // character match of 'a'), then we need not perform an additional input availability + // check before running the second alternative. + // + // Backtracking required differs for the last alternative, which in the case of the + // repeating set of alternatives must loop. The code generated for the last alternative + // will also be used to handle all input check failures from any prior alternatives - + // these require similar functionality, in seeking the next available alternative for + // which there is sufficient input. + // + // Since backtracking of all other alternatives simply requires us to link backtracks + // to the reentry point for the subsequent alternative, we will only be generating any + // code when backtracking the last alternative. + case OpBodyAlternativeBegin: + case OpBodyAlternativeNext: { + PatternAlternative* alternative = op.m_alternative; + + if (op.m_op == OpBodyAlternativeNext) { + PatternAlternative* priorAlternative = m_ops[op.m_previousOp].m_alternative; + m_checked += priorAlternative->m_minimumSize; + } + m_checked -= alternative->m_minimumSize; + + // Is this the last alternative? If not, then if we backtrack to this point we just + // need to jump to try to match the next alternative. + if (m_ops[op.m_nextOp].m_op != OpBodyAlternativeEnd) { + m_backtrackingState.linkTo(m_ops[op.m_nextOp].m_reentry, this); + break; + } + YarrOp& endOp = m_ops[op.m_nextOp]; + + YarrOp* beginOp = &op; + while (beginOp->m_op != OpBodyAlternativeBegin) { + ASSERT(beginOp->m_op == OpBodyAlternativeNext); + beginOp = &m_ops[beginOp->m_previousOp]; + } + + bool onceThrough = endOp.m_nextOp == notFound; + + // First, generate code to handle cases where we backtrack out of an attempted match + // of the last alternative. If this is a 'once through' set of alternatives then we + // have nothing to do - link this straight through to the End. + if (onceThrough) + m_backtrackingState.linkTo(endOp.m_reentry, this); + else { + // If we don't need to move the input poistion, and the pattern has a fixed size + // (in which case we omit the store of the start index until the pattern has matched) + // then we can just link the backtrack out of the last alternative straight to the + // head of the first alternative. + if (m_pattern.m_body->m_hasFixedSize + && (alternative->m_minimumSize > beginOp->m_alternative->m_minimumSize) + && (alternative->m_minimumSize - beginOp->m_alternative->m_minimumSize == 1)) + m_backtrackingState.linkTo(beginOp->m_reentry, this); + else { + // We need to generate a trampoline of code to execute before looping back + // around to the first alternative. + m_backtrackingState.link(this); + + // If the pattern size is not fixed, then store the start index, for use if we match. + if (!m_pattern.m_body->m_hasFixedSize) { + if (alternative->m_minimumSize == 1) + setMatchStart(index); + else { + move(index, regT0); + if (alternative->m_minimumSize) + sub32(Imm32(alternative->m_minimumSize - 1), regT0); + else + add32(TrustedImm32(1), regT0); + setMatchStart(regT0); + } + } + + // Generate code to loop. Check whether the last alternative is longer than the + // first (e.g. /a|xy/ or /a|xyz/). + if (alternative->m_minimumSize > beginOp->m_alternative->m_minimumSize) { + // We want to loop, and increment input position. If the delta is 1, it is + // already correctly incremented, if more than one then decrement as appropriate. + unsigned delta = alternative->m_minimumSize - beginOp->m_alternative->m_minimumSize; + ASSERT(delta); + if (delta != 1) + sub32(Imm32(delta - 1), index); + jump(beginOp->m_reentry); + } else { + // If the first alternative has minimum size 0xFFFFFFFFu, then there cannot + // be sufficent input available to handle this, so just fall through. + unsigned delta = beginOp->m_alternative->m_minimumSize - alternative->m_minimumSize; + if (delta != 0xFFFFFFFFu) { + // We need to check input because we are incrementing the input. + add32(Imm32(delta + 1), index); + checkInput().linkTo(beginOp->m_reentry, this); + } + } + } + } + + // We can reach this point in the code in two ways: + // - Fallthrough from the code above (a repeating alternative backtracked out of its + // last alternative, and did not have sufficent input to run the first). + // - We will loop back up to the following label when a releating alternative loops, + // following a failed input check. + // + // Either way, we have just failed the input check for the first alternative. + Label firstInputCheckFailed(this); + + // Generate code to handle input check failures from alternatives except the last. + // prevOp is the alternative we're handling a bail out from (initially Begin), and + // nextOp is the alternative we will be attempting to reenter into. + // + // We will link input check failures from the forwards matching path back to the code + // that can handle them. + YarrOp* prevOp = beginOp; + YarrOp* nextOp = &m_ops[beginOp->m_nextOp]; + while (nextOp->m_op != OpBodyAlternativeEnd) { + prevOp->m_jumps.link(this); + + // We only get here if an input check fails, it is only worth checking again + // if the next alternative has a minimum size less than the last. + if (prevOp->m_alternative->m_minimumSize > nextOp->m_alternative->m_minimumSize) { + // FIXME: if we added an extra label to YarrOp, we could avoid needing to + // subtract delta back out, and reduce this code. Should performance test + // the benefit of this. + unsigned delta = prevOp->m_alternative->m_minimumSize - nextOp->m_alternative->m_minimumSize; + sub32(Imm32(delta), index); + Jump fail = jumpIfNoAvailableInput(); + add32(Imm32(delta), index); + jump(nextOp->m_reentry); + fail.link(this); + } else if (prevOp->m_alternative->m_minimumSize < nextOp->m_alternative->m_minimumSize) + add32(Imm32(nextOp->m_alternative->m_minimumSize - prevOp->m_alternative->m_minimumSize), index); + prevOp = nextOp; + nextOp = &m_ops[nextOp->m_nextOp]; + } + + // We fall through to here if there is insufficient input to run the last alternative. + + // If there is insufficient input to run the last alternative, then for 'once through' + // alternatives we are done - just jump back up into the forwards matching path at the End. + if (onceThrough) { + op.m_jumps.linkTo(endOp.m_reentry, this); + jump(endOp.m_reentry); + break; + } + + // For repeating alternatives, link any input check failure from the last alternative to + // this point. + op.m_jumps.link(this); + + bool needsToUpdateMatchStart = !m_pattern.m_body->m_hasFixedSize; + + // Check for cases where input position is already incremented by 1 for the last + // alternative (this is particularly useful where the minimum size of the body + // disjunction is 0, e.g. /a*|b/). + if (needsToUpdateMatchStart && alternative->m_minimumSize == 1) { + // index is already incremented by 1, so just store it now! + setMatchStart(index); + needsToUpdateMatchStart = false; + } + + // Check whether there is sufficient input to loop. Increment the input position by + // one, and check. Also add in the minimum disjunction size before checking - there + // is no point in looping if we're just going to fail all the input checks around + // the next iteration. + ASSERT(alternative->m_minimumSize >= m_pattern.m_body->m_minimumSize); + if (alternative->m_minimumSize == m_pattern.m_body->m_minimumSize) { + // If the last alternative had the same minimum size as the disjunction, + // just simply increment input pos by 1, no adjustment based on minimum size. + add32(TrustedImm32(1), index); + } else { + // If the minumum for the last alternative was one greater than than that + // for the disjunction, we're already progressed by 1, nothing to do! + unsigned delta = (alternative->m_minimumSize - m_pattern.m_body->m_minimumSize) - 1; + if (delta) + sub32(Imm32(delta), index); + } + Jump matchFailed = jumpIfNoAvailableInput(); + + if (needsToUpdateMatchStart) { + if (!m_pattern.m_body->m_minimumSize) + setMatchStart(index); + else { + move(index, regT0); + sub32(Imm32(m_pattern.m_body->m_minimumSize), regT0); + setMatchStart(regT0); + } + } + + // Calculate how much more input the first alternative requires than the minimum + // for the body as a whole. If no more is needed then we dont need an additional + // input check here - jump straight back up to the start of the first alternative. + if (beginOp->m_alternative->m_minimumSize == m_pattern.m_body->m_minimumSize) + jump(beginOp->m_reentry); + else { + if (beginOp->m_alternative->m_minimumSize > m_pattern.m_body->m_minimumSize) + add32(Imm32(beginOp->m_alternative->m_minimumSize - m_pattern.m_body->m_minimumSize), index); + else + sub32(Imm32(m_pattern.m_body->m_minimumSize - beginOp->m_alternative->m_minimumSize), index); + checkInput().linkTo(beginOp->m_reentry, this); + jump(firstInputCheckFailed); + } + + // We jump to here if we iterate to the point that there is insufficient input to + // run any matches, and need to return a failure state from JIT code. + matchFailed.link(this); + + removeCallFrame(); + move(TrustedImmPtr((void*)WTF::notFound), returnRegister); + move(TrustedImm32(0), returnRegister2); + generateReturn(); + break; + } + case OpBodyAlternativeEnd: { + // We should never backtrack back into a body disjunction. + ASSERT(m_backtrackingState.isEmpty()); + + PatternAlternative* priorAlternative = m_ops[op.m_previousOp].m_alternative; + m_checked += priorAlternative->m_minimumSize; + break; + } + + // OpSimpleNestedAlternativeBegin/Next/End + // OpNestedAlternativeBegin/Next/End + // + // Generate code for when we backtrack back out of an alternative into + // a Begin or Next node, or when the entry input count check fails. If + // there are more alternatives we need to jump to the next alternative, + // if not we backtrack back out of the current set of parentheses. + // + // In the case of non-simple nested assertions we need to also link the + // 'return address' appropriately to backtrack back out into the correct + // alternative. + case OpSimpleNestedAlternativeBegin: + case OpSimpleNestedAlternativeNext: + case OpNestedAlternativeBegin: + case OpNestedAlternativeNext: { + YarrOp& nextOp = m_ops[op.m_nextOp]; + bool isBegin = op.m_previousOp == notFound; + bool isLastAlternative = nextOp.m_nextOp == notFound; + ASSERT(isBegin == (op.m_op == OpSimpleNestedAlternativeBegin || op.m_op == OpNestedAlternativeBegin)); + ASSERT(isLastAlternative == (nextOp.m_op == OpSimpleNestedAlternativeEnd || nextOp.m_op == OpNestedAlternativeEnd)); + + // Treat an input check failure the same as a failed match. + m_backtrackingState.append(op.m_jumps); + + // Set the backtracks to jump to the appropriate place. We may need + // to link the backtracks in one of three different way depending on + // the type of alternative we are dealing with: + // - A single alternative, with no simplings. + // - The last alternative of a set of two or more. + // - An alternative other than the last of a set of two or more. + // + // In the case of a single alternative on its own, we don't need to + // jump anywhere - if the alternative fails to match we can just + // continue to backtrack out of the parentheses without jumping. + // + // In the case of the last alternative in a set of more than one, we + // need to jump to return back out to the beginning. We'll do so by + // adding a jump to the End node's m_jumps list, and linking this + // when we come to generate the Begin node. For alternatives other + // than the last, we need to jump to the next alternative. + // + // If the alternative had adjusted the input position we must link + // backtracking to here, correct, and then jump on. If not we can + // link the backtracks directly to their destination. + if (op.m_checkAdjust) { + // Handle the cases where we need to link the backtracks here. + m_backtrackingState.link(this); + sub32(Imm32(op.m_checkAdjust), index); + if (!isLastAlternative) { + // An alternative that is not the last should jump to its successor. + jump(nextOp.m_reentry); + } else if (!isBegin) { + // The last of more than one alternatives must jump back to the beginning. + nextOp.m_jumps.append(jump()); + } else { + // A single alternative on its own can fall through. + m_backtrackingState.fallthrough(); + } + } else { + // Handle the cases where we can link the backtracks directly to their destinations. + if (!isLastAlternative) { + // An alternative that is not the last should jump to its successor. + m_backtrackingState.linkTo(nextOp.m_reentry, this); + } else if (!isBegin) { + // The last of more than one alternatives must jump back to the beginning. + m_backtrackingState.takeBacktracksToJumpList(nextOp.m_jumps, this); + } + // In the case of a single alternative on its own do nothing - it can fall through. + } + + // If there is a backtrack jump from a zero length match link it here. + if (op.m_zeroLengthMatch.isSet()) + m_backtrackingState.append(op.m_zeroLengthMatch); + + // At this point we've handled the backtracking back into this node. + // Now link any backtracks that need to jump to here. + + // For non-simple alternatives, link the alternative's 'return address' + // so that we backtrack back out into the previous alternative. + if (op.m_op == OpNestedAlternativeNext) + m_backtrackingState.append(op.m_returnAddress); + + // If there is more than one alternative, then the last alternative will + // have planted a jump to be linked to the end. This jump was added to the + // End node's m_jumps list. If we are back at the beginning, link it here. + if (isBegin) { + YarrOp* endOp = &m_ops[op.m_nextOp]; + while (endOp->m_nextOp != notFound) { + ASSERT(endOp->m_op == OpSimpleNestedAlternativeNext || endOp->m_op == OpNestedAlternativeNext); + endOp = &m_ops[endOp->m_nextOp]; + } + ASSERT(endOp->m_op == OpSimpleNestedAlternativeEnd || endOp->m_op == OpNestedAlternativeEnd); + m_backtrackingState.append(endOp->m_jumps); + } + + if (!isBegin) { + YarrOp& lastOp = m_ops[op.m_previousOp]; + m_checked += lastOp.m_checkAdjust; + } + m_checked -= op.m_checkAdjust; + break; + } + case OpSimpleNestedAlternativeEnd: + case OpNestedAlternativeEnd: { + PatternTerm* term = op.m_term; + + // If there is a backtrack jump from a zero length match link it here. + if (op.m_zeroLengthMatch.isSet()) + m_backtrackingState.append(op.m_zeroLengthMatch); + + // If we backtrack into the end of a simple subpattern do nothing; + // just continue through into the last alternative. If we backtrack + // into the end of a non-simple set of alterntives we need to jump + // to the backtracking return address set up during generation. + if (op.m_op == OpNestedAlternativeEnd) { + m_backtrackingState.link(this); + + // Plant a jump to the return address. + unsigned parenthesesFrameLocation = term->frameLocation; + unsigned alternativeFrameLocation = parenthesesFrameLocation; + if (term->quantityType != QuantifierFixedCount) + alternativeFrameLocation += YarrStackSpaceForBackTrackInfoParenthesesOnce; + loadFromFrameAndJump(alternativeFrameLocation); + + // Link the DataLabelPtr associated with the end of the last + // alternative to this point. + m_backtrackingState.append(op.m_returnAddress); + } + + YarrOp& lastOp = m_ops[op.m_previousOp]; + m_checked += lastOp.m_checkAdjust; + break; + } + + // OpParenthesesSubpatternOnceBegin/End + // + // When we are backtracking back out of a capturing subpattern we need + // to clear the start index in the matches output array, to record that + // this subpattern has not been captured. + // + // When backtracking back out of a Greedy quantified subpattern we need + // to catch this, and try running the remainder of the alternative after + // the subpattern again, skipping the parentheses. + // + // Upon backtracking back into a quantified set of parentheses we need to + // check whether we were currently skipping the subpattern. If not, we + // can backtrack into them, if we were we need to either backtrack back + // out of the start of the parentheses, or jump back to the forwards + // matching start, depending of whether the match is Greedy or NonGreedy. + case OpParenthesesSubpatternOnceBegin: { + PatternTerm* term = op.m_term; + ASSERT(term->quantityCount == 1); + + // We only need to backtrack to thispoint if capturing or greedy. + if ((term->capture() && compileMode == IncludeSubpatterns) || term->quantityType == QuantifierGreedy) { + m_backtrackingState.link(this); + + // If capturing, clear the capture (we only need to reset start). + if (term->capture() && compileMode == IncludeSubpatterns) + clearSubpatternStart(term->parentheses.subpatternId); + + // If Greedy, jump to the end. + if (term->quantityType == QuantifierGreedy) { + // Clear the flag in the stackframe indicating we ran through the subpattern. + unsigned parenthesesFrameLocation = term->frameLocation; + storeToFrame(TrustedImm32(-1), parenthesesFrameLocation); + // Jump to after the parentheses, skipping the subpattern. + jump(m_ops[op.m_nextOp].m_reentry); + // A backtrack from after the parentheses, when skipping the subpattern, + // will jump back to here. + op.m_jumps.link(this); + } + + m_backtrackingState.fallthrough(); + } + break; + } + case OpParenthesesSubpatternOnceEnd: { + PatternTerm* term = op.m_term; + + if (term->quantityType != QuantifierFixedCount) { + m_backtrackingState.link(this); + + // Check whether we should backtrack back into the parentheses, or if we + // are currently in a state where we had skipped over the subpattern + // (in which case the flag value on the stack will be -1). + unsigned parenthesesFrameLocation = term->frameLocation; + Jump hadSkipped = branch32(Equal, Address(stackPointerRegister, parenthesesFrameLocation * sizeof(void*)), TrustedImm32(-1)); + + if (term->quantityType == QuantifierGreedy) { + // For Greedy parentheses, we skip after having already tried going + // through the subpattern, so if we get here we're done. + YarrOp& beginOp = m_ops[op.m_previousOp]; + beginOp.m_jumps.append(hadSkipped); + } else { + // For NonGreedy parentheses, we try skipping the subpattern first, + // so if we get here we need to try running through the subpattern + // next. Jump back to the start of the parentheses in the forwards + // matching path. + ASSERT(term->quantityType == QuantifierNonGreedy); + YarrOp& beginOp = m_ops[op.m_previousOp]; + hadSkipped.linkTo(beginOp.m_reentry, this); + } + + m_backtrackingState.fallthrough(); + } + + m_backtrackingState.append(op.m_jumps); + break; + } + + // OpParenthesesSubpatternTerminalBegin/End + // + // Terminal subpatterns will always match - there is nothing after them to + // force a backtrack, and they have a minimum count of 0, and as such will + // always produce an acceptable result. + case OpParenthesesSubpatternTerminalBegin: { + // We will backtrack to this point once the subpattern cannot match any + // more. Since no match is accepted as a successful match (we are Greedy + // quantified with a minimum of zero) jump back to the forwards matching + // path at the end. + YarrOp& endOp = m_ops[op.m_nextOp]; + m_backtrackingState.linkTo(endOp.m_reentry, this); + break; + } + case OpParenthesesSubpatternTerminalEnd: + // We should never be backtracking to here (hence the 'terminal' in the name). + ASSERT(m_backtrackingState.isEmpty()); + m_backtrackingState.append(op.m_jumps); + break; + + // OpParentheticalAssertionBegin/End + case OpParentheticalAssertionBegin: { + PatternTerm* term = op.m_term; + YarrOp& endOp = m_ops[op.m_nextOp]; + + // We need to handle the backtracks upon backtracking back out + // of a parenthetical assertion if either we need to correct + // the input index, or the assertion was inverted. + if (op.m_checkAdjust || term->invert()) { + m_backtrackingState.link(this); + + if (op.m_checkAdjust) + add32(Imm32(op.m_checkAdjust), index); + + // In an inverted assertion failure to match the subpattern + // is treated as a successful match - jump to the end of the + // subpattern. We already have adjusted the input position + // back to that before the assertion, which is correct. + if (term->invert()) + jump(endOp.m_reentry); + + m_backtrackingState.fallthrough(); + } + + // The End node's jump list will contain any backtracks into + // the end of the assertion. Also, if inverted, we will have + // added the failure caused by a successful match to this. + m_backtrackingState.append(endOp.m_jumps); + + m_checked += op.m_checkAdjust; + break; + } + case OpParentheticalAssertionEnd: { + // FIXME: We should really be clearing any nested subpattern + // matches on bailing out from after the pattern. Firefox has + // this bug too (presumably because they use YARR!) + + // Never backtrack into an assertion; later failures bail to before the begin. + m_backtrackingState.takeBacktracksToJumpList(op.m_jumps, this); + + YarrOp& lastOp = m_ops[op.m_previousOp]; + m_checked -= lastOp.m_checkAdjust; + break; + } + + case OpMatchFailed: + break; + } + + } while (opIndex); + } + + // Compilation methods: + // ==================== + + // opCompileParenthesesSubpattern + // Emits ops for a subpattern (set of parentheses). These consist + // of a set of alternatives wrapped in an outer set of nodes for + // the parentheses. + // Supported types of parentheses are 'Once' (quantityCount == 1) + // and 'Terminal' (non-capturing parentheses quantified as greedy + // and infinite). + // Alternatives will use the 'Simple' set of ops if either the + // subpattern is terminal (in which case we will never need to + // backtrack), or if the subpattern only contains one alternative. + void opCompileParenthesesSubpattern(PatternTerm* term) + { + YarrOpCode parenthesesBeginOpCode; + YarrOpCode parenthesesEndOpCode; + YarrOpCode alternativeBeginOpCode = OpSimpleNestedAlternativeBegin; + YarrOpCode alternativeNextOpCode = OpSimpleNestedAlternativeNext; + YarrOpCode alternativeEndOpCode = OpSimpleNestedAlternativeEnd; + + // We can currently only compile quantity 1 subpatterns that are + // not copies. We generate a copy in the case of a range quantifier, + // e.g. /(?:x){3,9}/, or /(?:x)+/ (These are effectively expanded to + // /(?:x){3,3}(?:x){0,6}/ and /(?:x)(?:x)*/ repectively). The problem + // comes where the subpattern is capturing, in which case we would + // need to restore the capture from the first subpattern upon a + // failure in the second. + if (term->quantityCount == 1 && !term->parentheses.isCopy) { + // Select the 'Once' nodes. + parenthesesBeginOpCode = OpParenthesesSubpatternOnceBegin; + parenthesesEndOpCode = OpParenthesesSubpatternOnceEnd; + + // If there is more than one alternative we cannot use the 'simple' nodes. + if (term->parentheses.disjunction->m_alternatives.size() != 1) { + alternativeBeginOpCode = OpNestedAlternativeBegin; + alternativeNextOpCode = OpNestedAlternativeNext; + alternativeEndOpCode = OpNestedAlternativeEnd; + } + } else if (term->parentheses.isTerminal) { + // Select the 'Terminal' nodes. + parenthesesBeginOpCode = OpParenthesesSubpatternTerminalBegin; + parenthesesEndOpCode = OpParenthesesSubpatternTerminalEnd; + } else { + // This subpattern is not supported by the JIT. + m_shouldFallBack = true; + return; + } + + size_t parenBegin = m_ops.size(); + m_ops.append(parenthesesBeginOpCode); + + m_ops.append(alternativeBeginOpCode); + m_ops.last().m_previousOp = notFound; + m_ops.last().m_term = term; + Vector<PatternAlternative*>& alternatives = term->parentheses.disjunction->m_alternatives; + for (unsigned i = 0; i < alternatives.size(); ++i) { + size_t lastOpIndex = m_ops.size() - 1; + + PatternAlternative* nestedAlternative = alternatives[i]; + opCompileAlternative(nestedAlternative); + + size_t thisOpIndex = m_ops.size(); + m_ops.append(YarrOp(alternativeNextOpCode)); + + YarrOp& lastOp = m_ops[lastOpIndex]; + YarrOp& thisOp = m_ops[thisOpIndex]; + + lastOp.m_alternative = nestedAlternative; + lastOp.m_nextOp = thisOpIndex; + thisOp.m_previousOp = lastOpIndex; + thisOp.m_term = term; + } + YarrOp& lastOp = m_ops.last(); + ASSERT(lastOp.m_op == alternativeNextOpCode); + lastOp.m_op = alternativeEndOpCode; + lastOp.m_alternative = 0; + lastOp.m_nextOp = notFound; + + size_t parenEnd = m_ops.size(); + m_ops.append(parenthesesEndOpCode); + + m_ops[parenBegin].m_term = term; + m_ops[parenBegin].m_previousOp = notFound; + m_ops[parenBegin].m_nextOp = parenEnd; + m_ops[parenEnd].m_term = term; + m_ops[parenEnd].m_previousOp = parenBegin; + m_ops[parenEnd].m_nextOp = notFound; + } + + // opCompileParentheticalAssertion + // Emits ops for a parenthetical assertion. These consist of an + // OpSimpleNestedAlternativeBegin/Next/End set of nodes wrapping + // the alternatives, with these wrapped by an outer pair of + // OpParentheticalAssertionBegin/End nodes. + // We can always use the OpSimpleNestedAlternative nodes in the + // case of parenthetical assertions since these only ever match + // once, and will never backtrack back into the assertion. + void opCompileParentheticalAssertion(PatternTerm* term) + { + size_t parenBegin = m_ops.size(); + m_ops.append(OpParentheticalAssertionBegin); + + m_ops.append(OpSimpleNestedAlternativeBegin); + m_ops.last().m_previousOp = notFound; + m_ops.last().m_term = term; + Vector<PatternAlternative*>& alternatives = term->parentheses.disjunction->m_alternatives; + for (unsigned i = 0; i < alternatives.size(); ++i) { + size_t lastOpIndex = m_ops.size() - 1; + + PatternAlternative* nestedAlternative = alternatives[i]; + opCompileAlternative(nestedAlternative); + + size_t thisOpIndex = m_ops.size(); + m_ops.append(YarrOp(OpSimpleNestedAlternativeNext)); + + YarrOp& lastOp = m_ops[lastOpIndex]; + YarrOp& thisOp = m_ops[thisOpIndex]; + + lastOp.m_alternative = nestedAlternative; + lastOp.m_nextOp = thisOpIndex; + thisOp.m_previousOp = lastOpIndex; + thisOp.m_term = term; + } + YarrOp& lastOp = m_ops.last(); + ASSERT(lastOp.m_op == OpSimpleNestedAlternativeNext); + lastOp.m_op = OpSimpleNestedAlternativeEnd; + lastOp.m_alternative = 0; + lastOp.m_nextOp = notFound; + + size_t parenEnd = m_ops.size(); + m_ops.append(OpParentheticalAssertionEnd); + + m_ops[parenBegin].m_term = term; + m_ops[parenBegin].m_previousOp = notFound; + m_ops[parenBegin].m_nextOp = parenEnd; + m_ops[parenEnd].m_term = term; + m_ops[parenEnd].m_previousOp = parenBegin; + m_ops[parenEnd].m_nextOp = notFound; + } + + // opCompileAlternative + // Called to emit nodes for all terms in an alternative. + void opCompileAlternative(PatternAlternative* alternative) + { + optimizeAlternative(alternative); + + for (unsigned i = 0; i < alternative->m_terms.size(); ++i) { + PatternTerm* term = &alternative->m_terms[i]; + + switch (term->type) { + case PatternTerm::TypeParenthesesSubpattern: + opCompileParenthesesSubpattern(term); + break; + + case PatternTerm::TypeParentheticalAssertion: + opCompileParentheticalAssertion(term); + break; + + default: + m_ops.append(term); + } + } + } + + // opCompileBody + // This method compiles the body disjunction of the regular expression. + // The body consists of two sets of alternatives - zero or more 'once + // through' (BOL anchored) alternatives, followed by zero or more + // repeated alternatives. + // For each of these two sets of alteratives, if not empty they will be + // wrapped in a set of OpBodyAlternativeBegin/Next/End nodes (with the + // 'begin' node referencing the first alternative, and 'next' nodes + // referencing any further alternatives. The begin/next/end nodes are + // linked together in a doubly linked list. In the case of repeating + // alternatives, the end node is also linked back to the beginning. + // If no repeating alternatives exist, then a OpMatchFailed node exists + // to return the failing result. + void opCompileBody(PatternDisjunction* disjunction) + { + Vector<PatternAlternative*>& alternatives = disjunction->m_alternatives; + size_t currentAlternativeIndex = 0; + + // Emit the 'once through' alternatives. + if (alternatives.size() && alternatives[0]->onceThrough()) { + m_ops.append(YarrOp(OpBodyAlternativeBegin)); + m_ops.last().m_previousOp = notFound; + + do { + size_t lastOpIndex = m_ops.size() - 1; + PatternAlternative* alternative = alternatives[currentAlternativeIndex]; + opCompileAlternative(alternative); + + size_t thisOpIndex = m_ops.size(); + m_ops.append(YarrOp(OpBodyAlternativeNext)); + + YarrOp& lastOp = m_ops[lastOpIndex]; + YarrOp& thisOp = m_ops[thisOpIndex]; + + lastOp.m_alternative = alternative; + lastOp.m_nextOp = thisOpIndex; + thisOp.m_previousOp = lastOpIndex; + + ++currentAlternativeIndex; + } while (currentAlternativeIndex < alternatives.size() && alternatives[currentAlternativeIndex]->onceThrough()); + + YarrOp& lastOp = m_ops.last(); + + ASSERT(lastOp.m_op == OpBodyAlternativeNext); + lastOp.m_op = OpBodyAlternativeEnd; + lastOp.m_alternative = 0; + lastOp.m_nextOp = notFound; + } + + if (currentAlternativeIndex == alternatives.size()) { + m_ops.append(YarrOp(OpMatchFailed)); + return; + } + + // Emit the repeated alternatives. + size_t repeatLoop = m_ops.size(); + m_ops.append(YarrOp(OpBodyAlternativeBegin)); + m_ops.last().m_previousOp = notFound; + do { + size_t lastOpIndex = m_ops.size() - 1; + PatternAlternative* alternative = alternatives[currentAlternativeIndex]; + ASSERT(!alternative->onceThrough()); + opCompileAlternative(alternative); + + size_t thisOpIndex = m_ops.size(); + m_ops.append(YarrOp(OpBodyAlternativeNext)); + + YarrOp& lastOp = m_ops[lastOpIndex]; + YarrOp& thisOp = m_ops[thisOpIndex]; + + lastOp.m_alternative = alternative; + lastOp.m_nextOp = thisOpIndex; + thisOp.m_previousOp = lastOpIndex; + + ++currentAlternativeIndex; + } while (currentAlternativeIndex < alternatives.size()); + YarrOp& lastOp = m_ops.last(); + ASSERT(lastOp.m_op == OpBodyAlternativeNext); + lastOp.m_op = OpBodyAlternativeEnd; + lastOp.m_alternative = 0; + lastOp.m_nextOp = repeatLoop; + } + + void generateEnter() + { +#if CPU(X86_64) + push(X86Registers::ebp); + move(stackPointerRegister, X86Registers::ebp); + push(X86Registers::ebx); +#elif CPU(X86) + push(X86Registers::ebp); + move(stackPointerRegister, X86Registers::ebp); + // TODO: do we need spill registers to fill the output pointer if there are no sub captures? + push(X86Registers::ebx); + push(X86Registers::edi); + push(X86Registers::esi); + // load output into edi (2 = saved ebp + return address). + #if COMPILER(MSVC) + loadPtr(Address(X86Registers::ebp, 2 * sizeof(void*)), input); + loadPtr(Address(X86Registers::ebp, 3 * sizeof(void*)), index); + loadPtr(Address(X86Registers::ebp, 4 * sizeof(void*)), length); + if (compileMode == IncludeSubpatterns) + loadPtr(Address(X86Registers::ebp, 5 * sizeof(void*)), output); + #else + if (compileMode == IncludeSubpatterns) + loadPtr(Address(X86Registers::ebp, 2 * sizeof(void*)), output); + #endif +#elif CPU(ARM) + push(ARMRegisters::r4); + push(ARMRegisters::r5); + push(ARMRegisters::r6); +#if CPU(ARM_TRADITIONAL) + push(ARMRegisters::r8); // scratch register +#endif + if (compileMode == IncludeSubpatterns) + move(ARMRegisters::r3, output); +#elif CPU(SH4) + push(SH4Registers::r11); + push(SH4Registers::r13); +#elif CPU(MIPS) + // Do nothing. +#endif + } + + void generateReturn() + { +#if CPU(X86_64) + pop(X86Registers::ebx); + pop(X86Registers::ebp); +#elif CPU(X86) + pop(X86Registers::esi); + pop(X86Registers::edi); + pop(X86Registers::ebx); + pop(X86Registers::ebp); +#elif CPU(ARM) +#if CPU(ARM_TRADITIONAL) + pop(ARMRegisters::r8); // scratch register +#endif + pop(ARMRegisters::r6); + pop(ARMRegisters::r5); + pop(ARMRegisters::r4); +#elif CPU(SH4) + pop(SH4Registers::r13); + pop(SH4Registers::r11); +#elif CPU(MIPS) + // Do nothing +#endif + ret(); + } + +public: + YarrGenerator(YarrPattern& pattern, YarrCharSize charSize) + : m_pattern(pattern) + , m_charSize(charSize) + , m_charScale(m_charSize == Char8 ? TimesOne: TimesTwo) + , m_shouldFallBack(false) + , m_checked(0) + { + } + + void compile(JSGlobalData* globalData, YarrCodeBlock& jitObject) + { + generateEnter(); + + Jump hasInput = checkInput(); + move(TrustedImmPtr((void*)WTF::notFound), returnRegister); + move(TrustedImm32(0), returnRegister2); + generateReturn(); + hasInput.link(this); + + if (compileMode == IncludeSubpatterns) { + for (unsigned i = 0; i < m_pattern.m_numSubpatterns + 1; ++i) + store32(TrustedImm32(-1), Address(output, (i << 1) * sizeof(int))); + } + + if (!m_pattern.m_body->m_hasFixedSize) + setMatchStart(index); + + initCallFrame(); + + // Compile the pattern to the internal 'YarrOp' representation. + opCompileBody(m_pattern.m_body); + + // If we encountered anything we can't handle in the JIT code + // (e.g. backreferences) then return early. + if (m_shouldFallBack) { + jitObject.setFallBack(true); + return; + } + + generate(); + backtrack(); + + // Link & finalize the code. + LinkBuffer linkBuffer(*globalData, this, REGEXP_CODE_ID); + m_backtrackingState.linkDataLabels(linkBuffer); + + if (compileMode == MatchOnly) { + if (m_charSize == Char8) + jitObject.set8BitCodeMatchOnly(FINALIZE_CODE(linkBuffer, ("Match-only 8-bit regular expression"))); + else + jitObject.set16BitCodeMatchOnly(FINALIZE_CODE(linkBuffer, ("Match-only 16-bit regular expression"))); + } else { + if (m_charSize == Char8) + jitObject.set8BitCode(FINALIZE_CODE(linkBuffer, ("8-bit regular expression"))); + else + jitObject.set16BitCode(FINALIZE_CODE(linkBuffer, ("16-bit regular expression"))); + } + jitObject.setFallBack(m_shouldFallBack); + } + +private: + YarrPattern& m_pattern; + + YarrCharSize m_charSize; + + Scale m_charScale; + + // Used to detect regular expression constructs that are not currently + // supported in the JIT; fall back to the interpreter when this is detected. + bool m_shouldFallBack; + + // The regular expression expressed as a linear sequence of operations. + Vector<YarrOp, 128> m_ops; + + // This records the current input offset being applied due to the current + // set of alternatives we are nested within. E.g. when matching the + // character 'b' within the regular expression /abc/, we will know that + // the minimum size for the alternative is 3, checked upon entry to the + // alternative, and that 'b' is at offset 1 from the start, and as such + // when matching 'b' we need to apply an offset of -2 to the load. + // + // FIXME: This should go away. Rather than tracking this value throughout + // code generation, we should gather this information up front & store it + // on the YarrOp structure. + int m_checked; + + // This class records state whilst generating the backtracking path of code. + BacktrackingState m_backtrackingState; +}; + +void jitCompile(YarrPattern& pattern, YarrCharSize charSize, JSGlobalData* globalData, YarrCodeBlock& jitObject, YarrJITCompileMode mode) +{ + if (mode == MatchOnly) + YarrGenerator<MatchOnly>(pattern, charSize).compile(globalData, jitObject); + else + YarrGenerator<IncludeSubpatterns>(pattern, charSize).compile(globalData, jitObject); +} + +}} + +#endif |