| |
| // |
| // file: regexcmp.cpp |
| // |
| // Copyright (C) 2002-2003 International Business Machines Corporation and others. |
| // All Rights Reserved. |
| // |
| // This file contains the ICU regular expression compiler, which is responsible |
| // for processing a regular expression pattern into the compiled form that |
| // is used by the match finding engine. |
| // |
| |
| #include "unicode/utypes.h" |
| |
| #if !UCONFIG_NO_REGULAR_EXPRESSIONS |
| |
| #include "unicode/unistr.h" |
| #include "unicode/uniset.h" |
| #include "unicode/uchar.h" |
| #include "unicode/uchriter.h" |
| #include "unicode/parsepos.h" |
| #include "unicode/parseerr.h" |
| #include "unicode/regex.h" |
| #include "uprops.h" |
| #include "cmemory.h" |
| #include "cstring.h" |
| #include "uvectr32.h" |
| #include "uassert.h" |
| #include "ucln_in.h" |
| #include "mutex.h" |
| |
| #include "regeximp.h" |
| #include "regexcst.h" // Contains state table for the regex pattern parser. |
| // generated by a Perl script. |
| #include "regexcmp.h" |
| #include "regexst.h" |
| |
| |
| |
| U_NAMESPACE_BEGIN |
| |
| |
| |
| |
| |
| //---------------------------------------------------------------------------------------- |
| // |
| // Constructor. |
| // |
| //---------------------------------------------------------------------------------------- |
| RegexCompile::RegexCompile(RegexPattern *rxp, UErrorCode &status) : fParenStack(status) |
| { |
| fStatus = &status; |
| |
| fRXPat = rxp; |
| fScanIndex = 0; |
| fNextIndex = 0; |
| fPeekChar = -1; |
| fLineNum = 1; |
| fCharNum = 0; |
| fQuoteMode = FALSE; |
| fInBackslashQuote = FALSE; |
| fModeFlags = fRXPat->fFlags; |
| fEOLComments = TRUE; |
| |
| fMatchOpenParen = -1; |
| fMatchCloseParen = -1; |
| fStringOpStart = -1; |
| |
| if (U_SUCCESS(status) && U_FAILURE(rxp->fDeferredStatus)) { |
| status = rxp->fDeferredStatus; |
| } |
| } |
| |
| |
| |
| //---------------------------------------------------------------------------------------- |
| // |
| // Destructor |
| // |
| //---------------------------------------------------------------------------------------- |
| RegexCompile::~RegexCompile() { |
| } |
| |
| |
| |
| //---------------------------------------------------------------------------------------- |
| // |
| // cleanup. Called (indirectly) by u_cleanup to free all cached memory |
| // |
| //---------------------------------------------------------------------------------------- |
| void RegexCompile::cleanup() { |
| delete RegexStaticSets::gStaticSets; |
| RegexStaticSets::gStaticSets = NULL; |
| } |
| |
| |
| //--------------------------------------------------------------------------------- |
| // |
| // Compile regex pattern. The state machine for rexexp pattern parsing is here. |
| // The state tables are hand-written in the file regexcst.txt, |
| // and converted to the form used here by a perl |
| // script regexcst.pl |
| // |
| //--------------------------------------------------------------------------------- |
| void RegexCompile::compile( |
| const UnicodeString &pat, // Source pat to be compiled. |
| UParseError &pp, // Error position info |
| UErrorCode &e) // Error Code |
| { |
| fStatus = &e; |
| fParseErr = &pp; |
| fStackPtr = 0; |
| fStack[fStackPtr] = 0; |
| |
| if (U_FAILURE(*fStatus)) { |
| return; |
| } |
| |
| // There should be no pattern stuff in the RegexPattern object. They can not be reused. |
| U_ASSERT(fRXPat->fPattern.length() == 0); |
| |
| // Prepare the RegexPattern object to receive the compiled pattern. |
| // TODO: remove per-instance field, and just use globals directly. (But check perf) |
| fRXPat->fPattern = pat; |
| fRXPat->fStaticSets = RegexStaticSets::gStaticSets->fPropSets; |
| fRXPat->fStaticSets8 = RegexStaticSets::gStaticSets->fPropSets8; |
| |
| |
| // Initialize the pattern scanning state machine |
| fPatternLength = pat.length(); |
| uint16_t state = 1; |
| const RegexTableEl *tableEl; |
| nextChar(fC); // Fetch the first char from the pattern string. |
| |
| // |
| // Main loop for the regex pattern parsing state machine. |
| // Runs once per state transition. |
| // Each time through optionally performs, depending on the state table, |
| // - an advance to the the next pattern char |
| // - an action to be performed. |
| // - pushing or popping a state to/from the local state return stack. |
| // file regexcst.txt is the source for the state table. The logic behind |
| // recongizing the pattern syntax is there, not here. |
| // |
| for (;;) { |
| // Bail out if anything has gone wrong. |
| // Regex pattern parsing stops on the first error encountered. |
| if (U_FAILURE(*fStatus)) { |
| break; |
| } |
| |
| U_ASSERT(state != 0); |
| |
| // Find the state table element that matches the input char from the pattern, or the |
| // class of the input character. Start with the first table row for this |
| // state, then linearly scan forward until we find a row that matches the |
| // character. The last row for each state always matches all characters, so |
| // the search will stop there, if not before. |
| // |
| tableEl = &gRuleParseStateTable[state]; |
| REGEX_SCAN_DEBUG_PRINTF( "char, line, col = (\'%c\', %d, %d) state=%s ", |
| fC.fChar, fLineNum, fCharNum, RegexStateNames[state]); |
| |
| for (;;) { // loop through table rows belonging to this state, looking for one |
| // that matches the current input char. |
| REGEX_SCAN_DEBUG_PRINTF( "."); |
| if (tableEl->fCharClass < 127 && fC.fQuoted == FALSE && tableEl->fCharClass == fC.fChar) { |
| // Table row specified an individual character, not a set, and |
| // the input character is not quoted, and |
| // the input character matched it. |
| break; |
| } |
| if (tableEl->fCharClass == 255) { |
| // Table row specified default, match anything character class. |
| break; |
| } |
| if (tableEl->fCharClass == 254 && fC.fQuoted) { |
| // Table row specified "quoted" and the char was quoted. |
| break; |
| } |
| if (tableEl->fCharClass == 253 && fC.fChar == (UChar32)-1) { |
| // Table row specified eof and we hit eof on the input. |
| break; |
| } |
| |
| if (tableEl->fCharClass >= 128 && tableEl->fCharClass < 240 && // Table specs a char class && |
| fC.fQuoted == FALSE && // char is not escaped && |
| fC.fChar != (UChar32)-1) { // char is not EOF |
| UnicodeSet *uniset = RegexStaticSets::gStaticSets->fRuleSets[tableEl->fCharClass-128]; |
| if (uniset->contains(fC.fChar)) { |
| // Table row specified a character class, or set of characters, |
| // and the current char matches it. |
| break; |
| } |
| } |
| |
| // No match on this row, advance to the next row for this state, |
| tableEl++; |
| } |
| REGEX_SCAN_DEBUG_PRINTF("\n"); |
| |
| // |
| // We've found the row of the state table that matches the current input |
| // character from the rules string. |
| // Perform any action specified by this row in the state table. |
| if (doParseActions((EParseAction)tableEl->fAction) == FALSE) { |
| // Break out of the state machine loop if the |
| // the action signalled some kind of error, or |
| // the action was to exit, occurs on normal end-of-rules-input. |
| break; |
| } |
| |
| if (tableEl->fPushState != 0) { |
| fStackPtr++; |
| if (fStackPtr >= kStackSize) { |
| error(U_REGEX_INTERNAL_ERROR); |
| REGEX_SCAN_DEBUG_PRINTF( "RegexCompile::parse() - state stack overflow.\n"); |
| fStackPtr--; |
| } |
| fStack[fStackPtr] = tableEl->fPushState; |
| } |
| |
| // |
| // NextChar. This is where characters are actually fetched from the pattern. |
| // Happens under control of the 'n' tag in the state table. |
| // |
| if (tableEl->fNextChar) { |
| nextChar(fC); |
| } |
| |
| // Get the next state from the table entry, or from the |
| // state stack if the next state was specified as "pop". |
| if (tableEl->fNextState != 255) { |
| state = tableEl->fNextState; |
| } else { |
| state = fStack[fStackPtr]; |
| fStackPtr--; |
| if (fStackPtr < 0) { |
| // state stack underflow |
| // This will occur if the user pattern has mis-matched parentheses, |
| // with extra close parens. |
| // |
| fStackPtr++; |
| error(U_REGEX_MISMATCHED_PAREN); |
| } |
| } |
| |
| } |
| |
| // |
| // The pattern has now been read and processed, and the compiled code generated. |
| // |
| |
| // Back-reference fixup |
| // |
| int32_t loc; |
| for (loc=0; loc<fRXPat->fCompiledPat->size(); loc++) { |
| int32_t op = fRXPat->fCompiledPat->elementAti(loc); |
| int32_t opType = URX_TYPE(op); |
| if (opType == URX_BACKREF || opType == URX_BACKREF_I) { |
| int32_t where = URX_VAL(op); |
| if (where > fRXPat->fGroupMap->size()) { |
| error(U_REGEX_INVALID_BACK_REF); |
| break; |
| } |
| where = fRXPat->fGroupMap->elementAti(where-1); |
| op = URX_BUILD(opType, where); |
| fRXPat->fCompiledPat->setElementAt(op, loc); |
| } |
| } |
| |
| |
| // |
| // Compute the number of digits requried for the largest capture group number. |
| // |
| fRXPat->fMaxCaptureDigits = 1; |
| int32_t n = 10; |
| for (;;) { |
| if (n > fRXPat->fGroupMap->size()) { |
| break; |
| } |
| fRXPat->fMaxCaptureDigits++; |
| n *= 10; |
| } |
| |
| // |
| // The pattern's fFrameSize so far has accumulated the requirements for |
| // storage for capture parentheses, counters, etc. that are encountered |
| // in the pattern. Add space for the two variables that are always |
| // present in the saved state: the input string position and the |
| // position in the compiled pattern. |
| // |
| fRXPat->fFrameSize+=2; |
| |
| // |
| // Get bounds for the minimum and maximum length of a string that this |
| // pattern can match. Used to avoid looking for matches in strings that |
| // are too short. |
| // |
| fRXPat->fMinMatchLen = minMatchLength(3, fRXPat->fCompiledPat->size()-1); |
| |
| // |
| // Optimization passes |
| // |
| matchStartType(); |
| OptDotStar(); |
| stripNOPs(); |
| |
| // |
| // Set up fast latin-1 range sets |
| // |
| int32_t numSets = fRXPat->fSets->size(); |
| fRXPat->fSets8 = new Regex8BitSet[numSets]; |
| int32_t i; |
| for (i=0; i<numSets; i++) { |
| UnicodeSet *s = (UnicodeSet *)fRXPat->fSets->elementAt(i); |
| fRXPat->fSets8[i].init(s); |
| } |
| |
| // |
| // A stupid bit of non-sense to prevent code coverage testing from complaining |
| // about the pattern.dump() debug function. Go through the motions of dumping, |
| // even though, without the #define set, it will do nothing. |
| // |
| #ifndef REGEX_DUMP_DEBUG |
| static UBool phonyDumpDone = FALSE; |
| if (phonyDumpDone==FALSE) { |
| fRXPat->dump(); |
| phonyDumpDone = TRUE; |
| } |
| #endif |
| |
| } |
| |
| |
| |
| |
| |
| //---------------------------------------------------------------------------------------- |
| // |
| // doParseAction Do some action during regex pattern parsing. |
| // Called by the parse state machine. |
| // |
| // Generation of the match engine PCode happens here, or |
| // in functions called from the parse actions defined here. |
| // |
| // |
| //---------------------------------------------------------------------------------------- |
| UBool RegexCompile::doParseActions(EParseAction action) |
| { |
| UBool returnVal = TRUE; |
| |
| switch ((Regex_PatternParseAction)action) { |
| |
| case doPatStart: |
| // Start of pattern compiles to: |
| //0 SAVE 2 Fall back to position of FAIL |
| //1 jmp 3 |
| //2 FAIL Stop if we ever reach here. |
| //3 NOP Dummy, so start of pattern looks the same as |
| // the start of an ( grouping. |
| //4 NOP Resreved, will be replaced by a save if there are |
| // OR | operators at the top level |
| fRXPat->fCompiledPat->addElement(URX_BUILD(URX_STATE_SAVE, 2), *fStatus); |
| fRXPat->fCompiledPat->addElement(URX_BUILD(URX_JMP, 3), *fStatus); |
| fRXPat->fCompiledPat->addElement(URX_BUILD(URX_FAIL, 0), *fStatus); |
| fRXPat->fCompiledPat->addElement(URX_BUILD(URX_NOP, 0), *fStatus); |
| fRXPat->fCompiledPat->addElement(URX_BUILD(URX_NOP, 0), *fStatus); |
| |
| fParenStack.push(-1, *fStatus); // Begin a Paren Stack Frame |
| fParenStack.push( 3, *fStatus); // Push location of first NOP |
| break; |
| |
| case doPatFinish: |
| // We've scanned to the end of the pattern |
| // The end of pattern compiles to: |
| // URX_END |
| // which will stop the runtime match engine. |
| // Encountering end of pattern also behaves like a close paren, |
| // and forces fixups of the State Save at the beginning of the compiled pattern |
| // and of any OR operations at the top level. |
| // |
| handleCloseParen(); |
| if (fParenStack.size() > 0) { |
| // Missing close paren in pattern. |
| error(U_REGEX_MISMATCHED_PAREN); |
| } |
| |
| // add the END operation to the compiled pattern. |
| fRXPat->fCompiledPat->addElement(URX_BUILD(URX_END, 0), *fStatus); |
| |
| // Terminate the pattern compilation state machine. |
| returnVal = FALSE; |
| break; |
| |
| |
| |
| case doOrOperator: |
| // Scanning a '|', as in (A|B) |
| { |
| // Insert a SAVE operation at the start of the pattern section preceding |
| // this OR at this level. This SAVE will branch the match forward |
| // to the right hand side of the OR in the event that the left hand |
| // side fails to match and backtracks. Locate the position for the |
| // save from the location on the top of the parentheses stack. |
| int32_t savePosition = fParenStack.popi(); |
| int32_t op = fRXPat->fCompiledPat->elementAti(savePosition); |
| U_ASSERT(URX_TYPE(op) == URX_NOP); // original contents of reserved location |
| op = URX_BUILD(URX_STATE_SAVE, fRXPat->fCompiledPat->size()+1); |
| fRXPat->fCompiledPat->setElementAt(op, savePosition); |
| |
| // Append an JMP operation into the compiled pattern. The operand for |
| // the JMP will eventually be the location following the ')' for the |
| // group. This will be patched in later, when the ')' is encountered. |
| op = URX_BUILD(URX_JMP, 0); |
| fRXPat->fCompiledPat->addElement(op, *fStatus); |
| |
| // Push the position of the newly added JMP op onto the parentheses stack. |
| // This registers if for fixup when this block's close paren is encountered. |
| fParenStack.push(fRXPat->fCompiledPat->size()-1, *fStatus); |
| |
| // Append a NOP to the compiled pattern. This is the slot reserved |
| // for a SAVE in the event that there is yet another '|' following |
| // this one. |
| fRXPat->fCompiledPat->addElement(URX_BUILD(URX_NOP, 0), *fStatus); |
| fParenStack.push(fRXPat->fCompiledPat->size()-1, *fStatus); |
| } |
| break; |
| |
| |
| case doOpenCaptureParen: |
| // Open Paren. |
| // Compile to a |
| // - NOP, which later may be replaced by a save-state if the |
| // parenthesized group gets a * quantifier, followed by |
| // - START_CAPTURE n where n is stack frame offset to the capture group variables. |
| // - NOP, which may later be replaced by a save-state if there |
| // is an '|' alternation within the parens. |
| // |
| // Each capture group gets three slots in the save stack frame: |
| // 0: Capture Group start position (in input string being matched.) |
| // 1: Capture Group end positino. |
| // 2: Start of Match-in-progress. |
| // The first two locations are for a completed capture group, and are |
| // referred to by back references and the like. |
| // The third location stores the capture start position when an START_CAPTURE is |
| // encountered. This will be promoted to a completed capture when (and if) the corresponding |
| // END_CAPure is encountered. |
| { |
| fRXPat->fCompiledPat->addElement(URX_BUILD(URX_NOP, 0), *fStatus); |
| int32_t varsLoc = fRXPat->fFrameSize; // Reserve three slots in match stack frame. |
| fRXPat->fFrameSize += 3; |
| int32_t cop = URX_BUILD(URX_START_CAPTURE, varsLoc); |
| fRXPat->fCompiledPat->addElement(cop, *fStatus); |
| fRXPat->fCompiledPat->addElement(URX_BUILD(URX_NOP, 0), *fStatus); |
| |
| // On the Parentheses stack, start a new frame and add the postions |
| // of the two NOPs. Depending on what follows in the pattern, the |
| // NOPs may be changed to SAVE_STATE or JMP ops, with a target |
| // address of the end of the parenthesized group. |
| fParenStack.push(fModeFlags, *fStatus); // Match mode state |
| fParenStack.push(capturing, *fStatus); // Frame type. |
| fParenStack.push(fRXPat->fCompiledPat->size()-3, *fStatus); // The first NOP location |
| fParenStack.push(fRXPat->fCompiledPat->size()-1, *fStatus); // The second NOP loc |
| |
| // Save the mapping from group number to stack frame variable position. |
| fRXPat->fGroupMap->addElement(varsLoc, *fStatus); |
| } |
| break; |
| |
| case doOpenNonCaptureParen: |
| // Open non-caputuring (grouping only) Paren. |
| // Compile to a |
| // - NOP, which later may be replaced by a save-state if the |
| // parenthesized group gets a * quantifier, followed by |
| // - NOP, which may later be replaced by a save-state if there |
| // is an '|' alternation within the parens. |
| { |
| fRXPat->fCompiledPat->addElement(URX_BUILD(URX_NOP, 0), *fStatus); |
| fRXPat->fCompiledPat->addElement(URX_BUILD(URX_NOP, 0), *fStatus); |
| |
| // On the Parentheses stack, start a new frame and add the postions |
| // of the two NOPs. |
| fParenStack.push(fModeFlags, *fStatus); // Match mode state |
| fParenStack.push(plain, *fStatus); // Begin a new frame. |
| fParenStack.push(fRXPat->fCompiledPat->size()-2, *fStatus); // The first NOP location |
| fParenStack.push(fRXPat->fCompiledPat->size()-1, *fStatus); // The second NOP loc |
| } |
| break; |
| |
| |
| case doOpenAtomicParen: |
| // Open Atomic Paren. (?> |
| // Compile to a |
| // - NOP, which later may be replaced if the parenthesized group |
| // has a quantifier, followed by |
| // - STO_SP save state stack position, so it can be restored at the ")" |
| // - NOP, which may later be replaced by a save-state if there |
| // is an '|' alternation within the parens. |
| { |
| fRXPat->fCompiledPat->addElement(URX_BUILD(URX_NOP, 0), *fStatus); |
| int32_t varLoc = fRXPat->fDataSize; // Reserve a data location for saving the |
| fRXPat->fDataSize += 1; // state stack ptr. |
| int32_t stoOp = URX_BUILD(URX_STO_SP, varLoc); |
| fRXPat->fCompiledPat->addElement(stoOp, *fStatus); |
| fRXPat->fCompiledPat->addElement(URX_BUILD(URX_NOP, 0), *fStatus); |
| |
| // On the Parentheses stack, start a new frame and add the postions |
| // of the two NOPs. Depending on what follows in the pattern, the |
| // NOPs may be changed to SAVE_STATE or JMP ops, with a target |
| // address of the end of the parenthesized group. |
| fParenStack.push(fModeFlags, *fStatus); // Match mode state |
| fParenStack.push(atomic, *fStatus); // Frame type. |
| fParenStack.push(fRXPat->fCompiledPat->size()-3, *fStatus); // The first NOP |
| fParenStack.push(fRXPat->fCompiledPat->size()-1, *fStatus); // The second NOP |
| } |
| break; |
| |
| |
| case doOpenLookAhead: |
| // Positive Look-ahead (?= stuff ) |
| // Compiles to |
| // 1 START_LA dataLoc |
| // 2. NOP reserved for use by quantifiers on the block. |
| // Look-ahead can't have quantifiers, but paren stack |
| // compile time conventions require the slot anyhow. |
| // 3. NOP may be replaced if there is are '|' ops in the block. |
| // 4. code for parenthesized stuff. |
| // 5. ENDLA |
| // |
| // Two data slots are reserved, for saving the stack ptr and the input position. |
| { |
| int32_t dataLoc = fRXPat->fDataSize; |
| fRXPat->fDataSize += 2; |
| int32_t op = URX_BUILD(URX_LA_START, dataLoc); |
| fRXPat->fCompiledPat->addElement(op, *fStatus); |
| |
| op = URX_BUILD(URX_NOP, 0); |
| fRXPat->fCompiledPat->addElement(op, *fStatus); |
| fRXPat->fCompiledPat->addElement(op, *fStatus); |
| |
| // On the Parentheses stack, start a new frame and add the postions |
| // of the NOPs. |
| fParenStack.push(fModeFlags, *fStatus); // Match mode state |
| fParenStack.push(lookAhead, *fStatus); // Frame type. |
| fParenStack.push(fRXPat->fCompiledPat->size()-2, *fStatus); // The first NOP location |
| fParenStack.push(fRXPat->fCompiledPat->size()-1, *fStatus); // The second NOP location |
| } |
| break; |
| |
| case doOpenLookAheadNeg: |
| // Negated Lookahead. (?! stuff ) |
| // Compiles to |
| // 1. START_LA dataloc |
| // 2. SAVE_STATE 7 // Fail within look-ahead block restores to this state, |
| // // which continues with the match. |
| // 3. NOP // Std. Open Paren sequence, for possible '|' |
| // 4. code for parenthesized stuff. |
| // 5. END_LA // Cut back stack, remove saved state from step 2. |
| // 6. FAIL // code in block succeeded, so neg. lookahead fails. |
| // 7. ... |
| { |
| int32_t dataLoc = fRXPat->fDataSize; |
| fRXPat->fDataSize += 2; |
| int32_t op = URX_BUILD(URX_LA_START, dataLoc); |
| fRXPat->fCompiledPat->addElement(op, *fStatus); |
| |
| op = URX_BUILD(URX_STATE_SAVE, 0); // dest address will be patched later. |
| fRXPat->fCompiledPat->addElement(op, *fStatus); |
| |
| op = URX_BUILD(URX_NOP, 0); |
| fRXPat->fCompiledPat->addElement(op, *fStatus); |
| |
| // On the Parentheses stack, start a new frame and add the postions |
| // of the StateSave and NOP. |
| fParenStack.push(fModeFlags, *fStatus); // Match mode state |
| fParenStack.push( negLookAhead, *fStatus); // Frame type |
| fParenStack.push(fRXPat->fCompiledPat->size()-2, *fStatus); // The STATE_SAVE location |
| fParenStack.push(fRXPat->fCompiledPat->size()-1, *fStatus); // The second NOP location |
| |
| // Instructions #5 and #6 will be added when the ')' is encountered. |
| } |
| break; |
| |
| case doOpenLookBehind: |
| { |
| // Compile a (?<= look-behind open paren. |
| // |
| // Compiles to |
| // 0 URX_LB_START dataLoc |
| // 1 URX_LB_CONT dataLoc |
| // 2 MinMatchLen |
| // 3 MaxMatchLen |
| // 4 URX_NOP Standard '(' boilerplate. |
| // 5 URX_NOP Reserved slot for use with '|' ops within (block). |
| // 6 <code for LookBehind expression> |
| // 7 URX_LB_END dataLoc # Check match len, restore input len |
| // 8 URX_LA_END dataLoc # Restore stack, input pos |
| // |
| // Allocate a block of matcher data, to contain (when running a match) |
| // 0: Stack ptr on entry |
| // 1: Input Index on entry |
| // 2: Start index of match current match attempt. |
| // 3: Original Input String len. |
| |
| // Allocate data space |
| int32_t dataLoc = fRXPat->fDataSize; |
| fRXPat->fDataSize += 4; |
| |
| // Emit URX_LB_START |
| int32_t op = URX_BUILD(URX_LB_START, dataLoc); |
| fRXPat->fCompiledPat->addElement(op, *fStatus); |
| |
| // Emit URX_LB_CONT |
| op = URX_BUILD(URX_LB_CONT, dataLoc); |
| fRXPat->fCompiledPat->addElement(op, *fStatus); |
| fRXPat->fCompiledPat->addElement(0, *fStatus); // MinMatchLength. To be filled later. |
| fRXPat->fCompiledPat->addElement(0, *fStatus); // MaxMatchLength. To be filled later. |
| |
| // Emit the NOP |
| op = URX_BUILD(URX_NOP, 0); |
| fRXPat->fCompiledPat->addElement(op, *fStatus); |
| fRXPat->fCompiledPat->addElement(op, *fStatus); |
| |
| // On the Parentheses stack, start a new frame and add the postions |
| // of the URX_LB_CONT and the NOP. |
| fParenStack.push(fModeFlags, *fStatus); // Match mode state |
| fParenStack.push(lookBehind, *fStatus); // Frame type |
| fParenStack.push(fRXPat->fCompiledPat->size()-2, *fStatus); // The first NOP location |
| fParenStack.push(fRXPat->fCompiledPat->size()-1, *fStatus); // The 2nd NOP location |
| |
| // The final two instructions will be added when the ')' is encountered. |
| } |
| |
| break; |
| |
| case doOpenLookBehindNeg: |
| { |
| // Compile a (?<! negated look-behind open paren. |
| // |
| // Compiles to |
| // 0 URX_LB_START dataLoc # Save entry stack, input len |
| // 1 URX_LBN_CONT dataLoc # Iterate possible match positions |
| // 2 MinMatchLen |
| // 3 MaxMatchLen |
| // 4 continueLoc (9) |
| // 5 URX_NOP Standard '(' boilerplate. |
| // 6 URX_NOP Reserved slot for use with '|' ops within (block). |
| // 7 <code for LookBehind expression> |
| // 8 URX_LBN_END dataLoc # Check match len, cause a FAIL |
| // 9 ... |
| // |
| // Allocate a block of matcher data, to contain (when running a match) |
| // 0: Stack ptr on entry |
| // 1: Input Index on entry |
| // 2: Start index of match current match attempt. |
| // 3: Original Input String len. |
| |
| // Allocate data space |
| int32_t dataLoc = fRXPat->fDataSize; |
| fRXPat->fDataSize += 4; |
| |
| // Emit URX_LB_START |
| int32_t op = URX_BUILD(URX_LB_START, dataLoc); |
| fRXPat->fCompiledPat->addElement(op, *fStatus); |
| |
| // Emit URX_LBN_CONT |
| op = URX_BUILD(URX_LBN_CONT, dataLoc); |
| fRXPat->fCompiledPat->addElement(op, *fStatus); |
| fRXPat->fCompiledPat->addElement(0, *fStatus); // MinMatchLength. To be filled later. |
| fRXPat->fCompiledPat->addElement(0, *fStatus); // MaxMatchLength. To be filled later. |
| fRXPat->fCompiledPat->addElement(0, *fStatus); // Continue Loc. To be filled later. |
| |
| // Emit the NOP |
| op = URX_BUILD(URX_NOP, 0); |
| fRXPat->fCompiledPat->addElement(op, *fStatus); |
| fRXPat->fCompiledPat->addElement(op, *fStatus); |
| |
| // On the Parentheses stack, start a new frame and add the postions |
| // of the URX_LB_CONT and the NOP. |
| fParenStack.push(fModeFlags, *fStatus); // Match mode state |
| fParenStack.push(lookBehindN, *fStatus); // Frame type |
| fParenStack.push(fRXPat->fCompiledPat->size()-2, *fStatus); // The first NOP location |
| fParenStack.push(fRXPat->fCompiledPat->size()-1, *fStatus); // The 2nd NOP location |
| |
| // The final two instructions will be added when the ')' is encountered. |
| } |
| break; |
| |
| case doConditionalExpr: |
| // Conditionals such as (?(1)a:b) |
| case doPerlInline: |
| // Perl inline-condtionals. (?{perl code}a|b) We're not perl, no way to do them. |
| error(U_REGEX_UNIMPLEMENTED); |
| break; |
| |
| |
| case doCloseParen: |
| handleCloseParen(); |
| if (fParenStack.size() <= 0) { |
| // Extra close paren, or missing open paren. |
| error(U_REGEX_MISMATCHED_PAREN); |
| } |
| break; |
| |
| case doNOP: |
| break; |
| |
| |
| case doBadOpenParenType: |
| case doRuleError: |
| error(U_REGEX_RULE_SYNTAX); |
| break; |
| |
| |
| case doMismatchedParenErr: |
| error(U_REGEX_MISMATCHED_PAREN); |
| break; |
| |
| case doPlus: |
| // Normal '+' compiles to |
| // 1. stuff to be repeated (already built) |
| // 2. jmp-sav 1 |
| // 3. ... |
| // |
| // Or, if the item to be repeated can match a zero length string, |
| // 1. STO_INP_LOC data-loc |
| // 2. body of stuff to be repeated |
| // 3. JMP_SAV_X 2 |
| // 4. ... |
| |
| // |
| // Or, if the item to be repeated is simple |
| // 1. Item to be repeated. |
| // 2. LOOP_SR_I set number (assuming repeated item is a set ref) |
| // 3. LOOP_C stack location |
| { |
| int32_t topLoc = blockTopLoc(FALSE); // location of item #1 |
| int32_t frameLoc; |
| |
| // Check for simple constructs, which may get special optimized code. |
| if (topLoc == fRXPat->fCompiledPat->size() - 1) { |
| int32_t repeatedOp = fRXPat->fCompiledPat->elementAti(topLoc); |
| |
| if (URX_TYPE(repeatedOp) == URX_SETREF) { |
| // Emit optimized code for [char set]+ |
| int32_t loopOpI = URX_BUILD(URX_LOOP_SR_I, URX_VAL(repeatedOp)); |
| fRXPat->fCompiledPat->addElement(loopOpI, *fStatus); |
| frameLoc = fRXPat->fFrameSize; |
| fRXPat->fFrameSize++; |
| int32_t loopOpC = URX_BUILD(URX_LOOP_C, frameLoc); |
| fRXPat->fCompiledPat->addElement(loopOpC, *fStatus); |
| break; |
| } |
| |
| if (URX_TYPE(repeatedOp) == URX_DOTANY || |
| URX_TYPE(repeatedOp) == URX_DOTANY_ALL) { |
| // Emit Optimized code for .+ operations. |
| int32_t loopOpI = URX_BUILD(URX_LOOP_DOT_I, 0); |
| if (URX_TYPE(repeatedOp) == URX_DOTANY_ALL) { |
| // URX_LOOP_DOT_I operand is a flag indicating . matches any mode. |
| loopOpI |= 1; |
| } |
| fRXPat->fCompiledPat->addElement(loopOpI, *fStatus); |
| frameLoc = fRXPat->fFrameSize; |
| fRXPat->fFrameSize++; |
| int32_t loopOpC = URX_BUILD(URX_LOOP_C, frameLoc); |
| fRXPat->fCompiledPat->addElement(loopOpC, *fStatus); |
| break; |
| } |
| |
| } |
| |
| // General case. |
| |
| // Check for minimum match length of zero, which requires |
| // extra loop-breaking code. |
| if (minMatchLength(topLoc, fRXPat->fCompiledPat->size()-1) == 0) { |
| // Zero length match is possible. |
| // Emit the code sequence that can handle it. |
| insertOp(topLoc); |
| frameLoc = fRXPat->fFrameSize; |
| fRXPat->fFrameSize++; |
| |
| int32_t op = URX_BUILD(URX_STO_INP_LOC, frameLoc); |
| fRXPat->fCompiledPat->setElementAt(op, topLoc); |
| |
| op = URX_BUILD(URX_JMP_SAV_X, topLoc+1); |
| fRXPat->fCompiledPat->addElement(op, *fStatus); |
| } else { |
| // Simpler code when the repeated body must match something non-empty |
| int32_t jmpOp = URX_BUILD(URX_JMP_SAV, topLoc); |
| fRXPat->fCompiledPat->addElement(jmpOp, *fStatus); |
| } |
| } |
| break; |
| |
| case doNGPlus: |
| // Non-greedy '+?' compiles to |
| // 1. stuff to be repeated (already built) |
| // 2. state-save 1 |
| // 3. ... |
| { |
| int32_t topLoc = blockTopLoc(FALSE); |
| int32_t saveStateOp = URX_BUILD(URX_STATE_SAVE, topLoc); |
| fRXPat->fCompiledPat->addElement(saveStateOp, *fStatus); |
| } |
| break; |
| |
| |
| case doOpt: |
| // Normal (greedy) ? quantifier. |
| // Compiles to |
| // 1. state save 3 |
| // 2. body of optional block |
| // 3. ... |
| // Insert the state save into the compiled pattern, and we're done. |
| { |
| int32_t saveStateLoc = blockTopLoc(TRUE); |
| int32_t saveStateOp = URX_BUILD(URX_STATE_SAVE, fRXPat->fCompiledPat->size()); |
| fRXPat->fCompiledPat->setElementAt(saveStateOp, saveStateLoc); |
| } |
| break; |
| |
| case doNGOpt: |
| // Non-greedy ?? quantifier |
| // compiles to |
| // 1. jmp 4 |
| // 2. body of optional block |
| // 3 jmp 5 |
| // 4. state save 2 |
| // 5 ... |
| // This code is less than ideal, with two jmps instead of one, because we can only |
| // insert one instruction at the top of the block being iterated. |
| { |
| int32_t jmp1_loc = blockTopLoc(TRUE); |
| int32_t jmp2_loc = fRXPat->fCompiledPat->size(); |
| |
| int32_t jmp1_op = URX_BUILD(URX_JMP, jmp2_loc+1); |
| fRXPat->fCompiledPat->setElementAt(jmp1_op, jmp1_loc); |
| |
| int32_t jmp2_op = URX_BUILD(URX_JMP, jmp2_loc+2); |
| fRXPat->fCompiledPat->addElement(jmp2_op, *fStatus); |
| |
| int32_t save_op = URX_BUILD(URX_STATE_SAVE, jmp1_loc+1); |
| fRXPat->fCompiledPat->addElement(save_op, *fStatus); |
| } |
| break; |
| |
| |
| case doStar: |
| // Normal (greedy) * quantifier. |
| // Compiles to |
| // 1. STATE_SAVE 4 |
| // 2. body of stuff being iterated over |
| // 3. JMP_SAV 2 |
| // 4. ... |
| // |
| // Or, if the body is a simple [Set], |
| // 1. LOOP_SR_I set number |
| // 2. LOOP_C stack location |
| // ... |
| // |
| // Or if this is a .* |
| // 1. LOOP_DOT_I (. matches all mode flag) |
| // 2. LOOP_C stack location |
| // |
| // Or, if the body can match a zero-length string, to inhibit infinite loops, |
| // 1. STATE_SAVE 5 |
| // 2. STO_INP_LOC data-loc |
| // 3. body of stuff |
| // 4. JMP_SAV_X 2 |
| // 5. ... |
| { |
| // location of item #1, the STATE_SAVE |
| int32_t topLoc = blockTopLoc(FALSE); |
| int32_t dataLoc = -1; |
| |
| // Check for simple *, where the construct being repeated |
| // compiled to single opcode, and might be optimizable. |
| if (topLoc == fRXPat->fCompiledPat->size() - 1) { |
| int32_t repeatedOp = fRXPat->fCompiledPat->elementAti(topLoc); |
| |
| if (URX_TYPE(repeatedOp) == URX_SETREF) { |
| // Emit optimized code for a [char set]* |
| int32_t loopOpI = URX_BUILD(URX_LOOP_SR_I, URX_VAL(repeatedOp)); |
| fRXPat->fCompiledPat->setElementAt(loopOpI, topLoc); |
| dataLoc = fRXPat->fFrameSize; |
| fRXPat->fFrameSize++; |
| int32_t loopOpC = URX_BUILD(URX_LOOP_C, dataLoc); |
| fRXPat->fCompiledPat->addElement(loopOpC, *fStatus); |
| break; |
| } |
| |
| if (URX_TYPE(repeatedOp) == URX_DOTANY || |
| URX_TYPE(repeatedOp) == URX_DOTANY_ALL) { |
| // Emit Optimized code for .* operations. |
| int32_t loopOpI = URX_BUILD(URX_LOOP_DOT_I, 0); |
| if (URX_TYPE(repeatedOp) == URX_DOTANY_ALL) { |
| // URX_LOOP_DOT_I operand is a flag indicating . matches any mode. |
| loopOpI |= 1; |
| } |
| fRXPat->fCompiledPat->setElementAt(loopOpI, topLoc); |
| dataLoc = fRXPat->fFrameSize; |
| fRXPat->fFrameSize++; |
| int32_t loopOpC = URX_BUILD(URX_LOOP_C, dataLoc); |
| fRXPat->fCompiledPat->addElement(loopOpC, *fStatus); |
| break; |
| } |
| } |
| |
| // Emit general case code for this * |
| // The optimizations did not apply. |
| |
| int32_t saveStateLoc = blockTopLoc(TRUE); |
| int32_t jmpOp = URX_BUILD(URX_JMP_SAV, saveStateLoc+1); |
| |
| // Check for minimum match length of zero, which requires |
| // extra loop-breaking code. |
| if (minMatchLength(saveStateLoc, fRXPat->fCompiledPat->size()-1) == 0) { |
| insertOp(saveStateLoc); |
| dataLoc = fRXPat->fFrameSize; |
| fRXPat->fFrameSize++; |
| |
| int32_t op = URX_BUILD(URX_STO_INP_LOC, dataLoc); |
| fRXPat->fCompiledPat->setElementAt(op, saveStateLoc+1); |
| jmpOp = URX_BUILD(URX_JMP_SAV_X, saveStateLoc+2); |
| } |
| |
| // Locate the position in the compiled pattern where the match will continue |
| // after completing the *. (4 or 5 in the comment above) |
| int32_t continueLoc = fRXPat->fCompiledPat->size()+1; |
| |
| // Put together the save state op store it into the compiled code. |
| int32_t saveStateOp = URX_BUILD(URX_STATE_SAVE, continueLoc); |
| fRXPat->fCompiledPat->setElementAt(saveStateOp, saveStateLoc); |
| |
| // Append the URX_JMP_SAV or URX_JMPX operation to the compiled pattern. |
| fRXPat->fCompiledPat->addElement(jmpOp, *fStatus); |
| } |
| break; |
| |
| case doNGStar: |
| // Non-greedy *? quantifier |
| // compiles to |
| // 1. JMP 3 |
| // 2. body of stuff being iterated over |
| // 3. STATE_SAVE 2 |
| // 4 ... |
| { |
| int32_t jmpLoc = blockTopLoc(TRUE); // loc 1. |
| int32_t saveLoc = fRXPat->fCompiledPat->size(); // loc 3. |
| int32_t jmpOp = URX_BUILD(URX_JMP, saveLoc); |
| int32_t stateSaveOp = URX_BUILD(URX_STATE_SAVE, jmpLoc+1); |
| fRXPat->fCompiledPat->setElementAt(jmpOp, jmpLoc); |
| fRXPat->fCompiledPat->addElement(stateSaveOp, *fStatus); |
| } |
| break; |
| |
| |
| case doIntervalInit: |
| // The '{' opening an interval quantifier was just scanned. |
| // Init the counter varaiables that will accumulate the values as the digits |
| // are scanned. |
| fIntervalLow = 0; |
| fIntervalUpper = -1; |
| break; |
| |
| case doIntevalLowerDigit: |
| // Scanned a digit from the lower value of an {lower,upper} interval |
| { |
| int32_t digitValue = u_charDigitValue(fC.fChar); |
| U_ASSERT(digitValue >= 0); |
| fIntervalLow = fIntervalLow*10 + digitValue; |
| if (fIntervalLow < 0) { |
| error(U_REGEX_NUMBER_TOO_BIG); |
| } |
| } |
| break; |
| |
| case doIntervalUpperDigit: |
| // Scanned a digit from the upper value of an {lower,upper} interval |
| { |
| if (fIntervalUpper < 0) { |
| fIntervalUpper = 0; |
| } |
| int32_t digitValue = u_charDigitValue(fC.fChar); |
| U_ASSERT(digitValue >= 0); |
| fIntervalUpper = fIntervalUpper*10 + digitValue; |
| if (fIntervalLow < 0) { |
| error(U_REGEX_NUMBER_TOO_BIG); |
| } |
| } |
| break; |
| |
| case doIntervalSame: |
| // Scanned a single value interval like {27}. Upper = Lower. |
| fIntervalUpper = fIntervalLow; |
| break; |
| |
| case doInterval: |
| // Finished scanning a normal {lower,upper} interval. Generate the code for it. |
| if (compileInlineInterval() == FALSE) { |
| compileInterval(URX_CTR_INIT, URX_CTR_LOOP); |
| } |
| break; |
| |
| case doPossessiveInterval: |
| // Finished scanning a Possessive {lower,upper}+ interval. Generate the code for it. |
| { |
| // Remember the loc for the top of the block being looped over. |
| // (Can not reserve a slot in the compiled pattern at this time, becuase |
| // compileInterval needs to reserve also, and blockTopLoc can only reserve |
| // once per block.) |
| int32_t topLoc = blockTopLoc(FALSE); |
| |
| // Produce normal looping code. |
| compileInterval(URX_CTR_INIT, URX_CTR_LOOP); |
| |
| // Surround the just-emitted normal looping code with a STO_SP ... LD_SP |
| // just as if the loop was inclosed in atomic parentheses. |
| |
| // First the STO_SP before the start of the loop |
| insertOp(topLoc); |
| int32_t varLoc = fRXPat->fDataSize; // Reserve a data location for saving the |
| fRXPat->fDataSize += 1; // state stack ptr. |
| int32_t op = URX_BUILD(URX_STO_SP, varLoc); |
| fRXPat->fCompiledPat->setElementAt(op, topLoc); |
| |
| int32_t loopOp = fRXPat->fCompiledPat->popi(); |
| U_ASSERT(URX_TYPE(loopOp) == URX_CTR_LOOP && URX_VAL(loopOp) == topLoc); |
| loopOp++; // point LoopOp after the just-inserted STO_SP |
| fRXPat->fCompiledPat->push(loopOp, *fStatus); |
| |
| // Then the LD_SP after the end of the loop |
| op = URX_BUILD(URX_LD_SP, varLoc); |
| fRXPat->fCompiledPat->addElement(op, *fStatus); |
| } |
| |
| break; |
| |
| case doNGInterval: |
| // Finished scanning a non-greedy {lower,upper}? interval. Generate the code for it. |
| compileInterval(URX_CTR_INIT_NG, URX_CTR_LOOP_NG); |
| break; |
| |
| case doIntervalError: |
| error(U_REGEX_BAD_INTERVAL); |
| break; |
| |
| case doLiteralChar: |
| // We've just scanned a "normal" character from the pattern, |
| literalChar(fC.fChar); |
| break; |
| |
| |
| |
| case doDotAny: |
| // scanned a ".", match any single character. |
| { |
| int32_t op; |
| if (fModeFlags & UREGEX_DOTALL) { |
| op = URX_BUILD(URX_DOTANY_ALL, 0); |
| } else { |
| op = URX_BUILD(URX_DOTANY, 0); |
| } |
| fRXPat->fCompiledPat->addElement(op, *fStatus); |
| } |
| break; |
| |
| case doCaret: |
| { |
| int32_t op = (fModeFlags & UREGEX_MULTILINE)? URX_CARET_M : URX_CARET; |
| fRXPat->fCompiledPat->addElement(URX_BUILD(op, 0), *fStatus); |
| } |
| break; |
| |
| |
| case doDollar: |
| { |
| int32_t op = (fModeFlags & UREGEX_MULTILINE)? URX_DOLLAR_M : URX_DOLLAR; |
| fRXPat->fCompiledPat->addElement(URX_BUILD(op, 0), *fStatus); |
| } |
| break; |
| |
| case doBackslashA: |
| fRXPat->fCompiledPat->addElement(URX_BUILD(URX_CARET, 0), *fStatus); |
| break; |
| |
| case doBackslashB: |
| { |
| int32_t op = (fModeFlags & UREGEX_UWORD)? URX_BACKSLASH_BU : URX_BACKSLASH_B; |
| fRXPat->fCompiledPat->addElement(URX_BUILD(op, 1), *fStatus); |
| } |
| break; |
| |
| case doBackslashb: |
| { |
| int32_t op = (fModeFlags & UREGEX_UWORD)? URX_BACKSLASH_BU : URX_BACKSLASH_B; |
| fRXPat->fCompiledPat->addElement(URX_BUILD(op, 0), *fStatus); |
| } |
| break; |
| |
| case doBackslashD: |
| fRXPat->fCompiledPat->addElement(URX_BUILD(URX_BACKSLASH_D, 1), *fStatus); |
| break; |
| |
| case doBackslashd: |
| fRXPat->fCompiledPat->addElement(URX_BUILD(URX_BACKSLASH_D, 0), *fStatus); |
| break; |
| |
| case doBackslashG: |
| fRXPat->fCompiledPat->addElement(URX_BUILD(URX_BACKSLASH_G, 0), *fStatus); |
| break; |
| |
| case doBackslashS: |
| fRXPat->fCompiledPat->addElement( |
| URX_BUILD(URX_STAT_SETREF_N, URX_ISSPACE_SET), *fStatus); |
| break; |
| |
| case doBackslashs: |
| fRXPat->fCompiledPat->addElement( |
| URX_BUILD(URX_STATIC_SETREF, URX_ISSPACE_SET), *fStatus); |
| break; |
| |
| case doBackslashW: |
| fRXPat->fCompiledPat->addElement( |
| URX_BUILD(URX_STAT_SETREF_N, URX_ISWORD_SET), *fStatus); |
| break; |
| |
| case doBackslashw: |
| fRXPat->fCompiledPat->addElement( |
| URX_BUILD(URX_STATIC_SETREF, URX_ISWORD_SET), *fStatus); |
| break; |
| |
| case doBackslashX: |
| fRXPat->fCompiledPat->addElement(URX_BUILD(URX_BACKSLASH_X, 0), *fStatus); |
| break; |
| |
| |
| case doBackslashZ: |
| fRXPat->fCompiledPat->addElement(URX_BUILD(URX_DOLLAR, 0), *fStatus); |
| break; |
| |
| case doBackslashz: |
| fRXPat->fCompiledPat->addElement(URX_BUILD(URX_BACKSLASH_Z, 0), *fStatus); |
| break; |
| |
| case doEscapeError: |
| error(U_REGEX_BAD_ESCAPE_SEQUENCE); |
| break; |
| |
| case doExit: |
| returnVal = FALSE; |
| break; |
| |
| case doProperty: |
| { |
| UnicodeSet *theSet = scanProp(); |
| compileSet(theSet); |
| } |
| break; |
| |
| |
| case doScanUnicodeSet: |
| { |
| UnicodeSet *theSet = scanSet(); |
| compileSet(theSet); |
| } |
| break; |
| |
| case doEnterQuoteMode: |
| // Just scanned a \Q. Put character scanner into quote mode. |
| fQuoteMode = TRUE; |
| break; |
| |
| case doBackRef: |
| // BackReference. Somewhat unusual in that the front-end can not completely parse |
| // the regular expression, because the number of digits to be consumed |
| // depends on the number of capture groups that have been defined. So |
| // we have to do it here instead. |
| { |
| int32_t numCaptureGroups = fRXPat->fGroupMap->size(); |
| int32_t groupNum = 0; |
| UChar32 c = fC.fChar; |
| |
| for (;;) { |
| // Loop once per digit, for max allowed number of digits in a back reference. |
| int32_t digit = u_charDigitValue(c); |
| groupNum = groupNum * 10 + digit; |
| if (groupNum >= numCaptureGroups) { |
| break; |
| } |
| c = peekCharLL(); |
| if (RegexStaticSets::gStaticSets->fRuleDigits->contains(c) == FALSE) { |
| break; |
| } |
| nextCharLL(); |
| } |
| |
| // Scan of the back reference in the source regexp is complete. Now generate |
| // the compiled code for it. |
| // Because capture groups can be forward-referenced by back-references, |
| // we fill the operand with the capture group number. At the end |
| // of compilation, it will be changed to the variable's location. |
| U_ASSERT(groupNum > 0); |
| int32_t op; |
| if (fModeFlags & UREGEX_CASE_INSENSITIVE) { |
| op = URX_BUILD(URX_BACKREF_I, groupNum); |
| } else { |
| op = URX_BUILD(URX_BACKREF, groupNum); |
| } |
| fRXPat->fCompiledPat->addElement(op, *fStatus); |
| } |
| break; |
| |
| |
| case doPossessivePlus: |
| // Possessive ++ quantifier. |
| // Compiles to |
| // 1. STO_SP |
| // 2. body of stuff being iterated over |
| // 3. STATE_SAVE 5 |
| // 4. JMP 2 |
| // 5. LD_SP |
| // 6. ... |
| // |
| // Note: TODO: This is pretty inefficient. A mass of saved state is built up |
| // then unconditionally discarded. Perhaps introduce a new opcode |
| // |
| { |
| // Emit the STO_SP |
| int32_t topLoc = blockTopLoc(TRUE); |
| int32_t stoLoc = fRXPat->fDataSize; |
| fRXPat->fDataSize++; // Reserve the data location for storing save stack ptr. |
| int32_t op = URX_BUILD(URX_STO_SP, stoLoc); |
| fRXPat->fCompiledPat->setElementAt(op, topLoc); |
| |
| // Emit the STATE_SAVE |
| op = URX_BUILD(URX_STATE_SAVE, fRXPat->fCompiledPat->size()+2); |
| fRXPat->fCompiledPat->addElement(op, *fStatus); |
| |
| // Emit the JMP |
| op = URX_BUILD(URX_JMP, topLoc+1); |
| fRXPat->fCompiledPat->addElement(op, *fStatus); |
| |
| // Emit the LD_SP |
| op = URX_BUILD(URX_LD_SP, stoLoc); |
| fRXPat->fCompiledPat->addElement(op, *fStatus); |
| } |
| break; |
| |
| case doPossessiveStar: |
| // Possessive *+ quantifier. |
| // Compiles to |
| // 1. STO_SP loc |
| // 2. STATE_SAVE 5 |
| // 3. body of stuff being iterated over |
| // 4. JMP 2 |
| // 5. LD_SP loc |
| // 6 ... |
| // TODO: do something to cut back the state stack each time through the loop. |
| { |
| // Reserve two slots at the top of the block. |
| int32_t topLoc = blockTopLoc(TRUE); |
| insertOp(topLoc); |
| |
| // emit STO_SP loc |
| int32_t stoLoc = fRXPat->fDataSize; |
| fRXPat->fDataSize++; // Reserve the data location for storing save stack ptr. |
| int32_t op = URX_BUILD(URX_STO_SP, stoLoc); |
| fRXPat->fCompiledPat->setElementAt(op, topLoc); |
| |
| // Emit the SAVE_STATE 5 |
| int32_t L7 = fRXPat->fCompiledPat->size()+1; |
| op = URX_BUILD(URX_STATE_SAVE, L7); |
| fRXPat->fCompiledPat->setElementAt(op, topLoc+1); |
| |
| // Append the JMP operation. |
| op = URX_BUILD(URX_JMP, topLoc+1); |
| fRXPat->fCompiledPat->addElement(op, *fStatus); |
| |
| // Emit the LD_SP loc |
| op = URX_BUILD(URX_LD_SP, stoLoc); |
| fRXPat->fCompiledPat->addElement(op, *fStatus); |
| } |
| break; |
| |
| case doPossessiveOpt: |
| // Possessive ?+ quantifier. |
| // Compiles to |
| // 1. STO_SP loc |
| // 2. SAVE_STATE 5 |
| // 3. body of optional block |
| // 4. LD_SP loc |
| // 5. ... |
| // |
| { |
| // Reserve two slots at the top of the block. |
| int32_t topLoc = blockTopLoc(TRUE); |
| insertOp(topLoc); |
| |
| // Emit the STO_SP |
| int32_t stoLoc = fRXPat->fDataSize; |
| fRXPat->fDataSize++; // Reserve the data location for storing save stack ptr. |
| int32_t op = URX_BUILD(URX_STO_SP, stoLoc); |
| fRXPat->fCompiledPat->setElementAt(op, topLoc); |
| |
| // Emit the SAVE_STATE |
| int32_t continueLoc = fRXPat->fCompiledPat->size()+1; |
| op = URX_BUILD(URX_STATE_SAVE, continueLoc); |
| fRXPat->fCompiledPat->setElementAt(op, topLoc+1); |
| |
| // Emit the LD_SP |
| op = URX_BUILD(URX_LD_SP, stoLoc); |
| fRXPat->fCompiledPat->addElement(op, *fStatus); |
| } |
| break; |
| |
| |
| case doBeginMatchMode: |
| fNewModeFlags = fModeFlags; |
| fSetModeFlag = TRUE; |
| break; |
| |
| case doMatchMode: // (?i) and similar |
| { |
| int32_t bit = 0; |
| switch (fC.fChar) { |
| case 0x69: /* 'i' */ bit = UREGEX_CASE_INSENSITIVE; break; |
| case 0x6d: /* 'm' */ bit = UREGEX_MULTILINE; break; |
| case 0x73: /* 's' */ bit = UREGEX_DOTALL; break; |
| case 0x77: /* 'w' */ bit = UREGEX_UWORD; break; |
| case 0x78: /* 'x' */ bit = UREGEX_COMMENTS; break; |
| case 0x2d: /* '-' */ fSetModeFlag = FALSE; break; |
| default: |
| U_ASSERT(FALSE); // Should never happen. Other chars are filtered out |
| // by the scanner. |
| } |
| if (fSetModeFlag) { |
| fNewModeFlags |= bit; |
| } else { |
| fNewModeFlags &= ~bit; |
| } |
| } |
| break; |
| |
| case doSetMatchMode: |
| // We've got a (?i) or similar. The match mode is being changed, but |
| // the change is not scoped to a parenthesized block. |
| fModeFlags = fNewModeFlags; |
| |
| // Prevent any string from spanning across the change of match mode. |
| // Otherwise the pattern "abc(?i)def" would make a single string of "abcdef" |
| fixLiterals(); |
| break; |
| |
| |
| case doMatchModeParen: |
| // We've got a (?i: or similar. Begin a parenthesized block, save old |
| // mode flags so they can be restored at the close of the block. |
| // |
| // Compile to a |
| // - NOP, which later may be replaced by a save-state if the |
| // parenthesized group gets a * quantifier, followed by |
| // - NOP, which may later be replaced by a save-state if there |
| // is an '|' alternation within the parens. |
| { |
| fRXPat->fCompiledPat->addElement(URX_BUILD(URX_NOP, 0), *fStatus); |
| fRXPat->fCompiledPat->addElement(URX_BUILD(URX_NOP, 0), *fStatus); |
| |
| // On the Parentheses stack, start a new frame and add the postions |
| // of the two NOPs (a normal non-capturing () frame, except for the |
| // saving of the orignal mode flags.) |
| fParenStack.push(fModeFlags, *fStatus); |
| fParenStack.push(flags, *fStatus); // Frame Marker |
| fParenStack.push(fRXPat->fCompiledPat->size()-2, *fStatus); // The first NOP |
| fParenStack.push(fRXPat->fCompiledPat->size()-1, *fStatus); // The second NOP |
| |
| // Set the current mode flags to the new values. |
| fModeFlags = fNewModeFlags; |
| } |
| break; |
| |
| case doBadModeFlag: |
| error(U_REGEX_INVALID_FLAG); |
| break; |
| |
| case doSuppressComments: |
| // We have just scanned a '(?'. We now need to prevent the character scanner from |
| // treating a '#' as a to-the-end-of-line comment. |
| // (This Perl compatibility just gets uglier and uglier to do...) |
| fEOLComments = FALSE; |
| break; |
| |
| |
| |
| default: |
| U_ASSERT(FALSE); |
| error(U_REGEX_INTERNAL_ERROR); |
| break; |
| } |
| |
| if (U_FAILURE(*fStatus)) { |
| returnVal = FALSE; |
| } |
| |
| return returnVal; |
| }; |
| |
| |
| |
| //------------------------------------------------------------------------------ |
| // |
| // literalChar We've encountered a literal character from the pattern, |
| // or an escape sequence that reduces to a character. |
| // Add it to the string containing all literal chars/strings from |
| // the pattern. |
| // If we are in a pattern string already, add the new char to it. |
| // If we aren't in a pattern string, begin one now. |
| // |
| //------------------------------------------------------------------------------ |
| void RegexCompile::literalChar(UChar32 c) { |
| int32_t op; // An operation in the compiled pattern. |
| int32_t opType; |
| int32_t patternLoc; // A position in the compiled pattern. |
| int32_t stringLen; |
| |
| |
| // If the last thing compiled into the pattern was not a literal char, |
| // force this new literal char to begin a new string, and not append to the previous. |
| op = fRXPat->fCompiledPat->lastElementi(); |
| opType = URX_TYPE(op); |
| if (!(opType == URX_STRING_LEN || opType == URX_ONECHAR || opType == URX_ONECHAR_I)) { |
| fixLiterals(); |
| } |
| |
| if (fStringOpStart == -1) { |
| // First char of a string in the pattern. |
| // Emit a OneChar op into the compiled pattern. |
| emitONE_CHAR(c); |
| |
| // Also add it to the string pool, in case we get a second adjacent literal |
| // and want to change form ONE_CHAR to STRING |
| fStringOpStart = fRXPat->fLiteralText.length(); |
| fRXPat->fLiteralText.append(c); |
| return; |
| } |
| |
| // We are adding onto an existing string |
| fRXPat->fLiteralText.append(c); |
| |
| op = fRXPat->fCompiledPat->lastElementi(); |
| opType = URX_TYPE(op); |
| U_ASSERT(opType == URX_ONECHAR || opType == URX_ONECHAR_I || opType == URX_STRING_LEN); |
| |
| // If the most recently emitted op is a URX_ONECHAR, |
| if (opType == URX_ONECHAR || opType == URX_ONECHAR_I) { |
| if (U16_IS_TRAIL(c) && U16_IS_LEAD(URX_VAL(op))) { |
| // The most recently emitted op is a ONECHAR that was the first half |
| // of a surrogate pair. Update the ONECHAR's operand to be the |
| // supplementary code point resulting from both halves of the pair. |
| c = U16_GET_SUPPLEMENTARY(URX_VAL(op), c); |
| op = URX_BUILD(opType, c); |
| patternLoc = fRXPat->fCompiledPat->size() - 1; |
| fRXPat->fCompiledPat->setElementAt(op, patternLoc); |
| return; |
| } |
| |
| // The most recently emitted op is a ONECHAR. |
| // We've now received another adjacent char. Change the ONECHAR op |
| // to a string op. |
| if (fModeFlags & UREGEX_CASE_INSENSITIVE) { |
| op = URX_BUILD(URX_STRING_I, fStringOpStart); |
| } else { |
| op = URX_BUILD(URX_STRING, fStringOpStart); |
| } |
| patternLoc = fRXPat->fCompiledPat->size() - 1; |
| fRXPat->fCompiledPat->setElementAt(op, patternLoc); |
| op = URX_BUILD(URX_STRING_LEN, 0); |
| fRXPat->fCompiledPat->addElement(op, *fStatus); |
| } |
| |
| // The pattern contains a URX_SRING / URX_STRING_LEN. Update the |
| // string length to reflect the new char we just added to the string. |
| stringLen = fRXPat->fLiteralText.length() - fStringOpStart; |
| op = URX_BUILD(URX_STRING_LEN, stringLen); |
| patternLoc = fRXPat->fCompiledPat->size() - 1; |
| fRXPat->fCompiledPat->setElementAt(op, patternLoc); |
| } |
| |
| |
| |
| //------------------------------------------------------------------------------ |
| // |
| // emitONE_CHAR emit a ONE_CHAR op into the generated code. |
| // Choose cased or uncased version, depending on the |
| // match mode and whether the character itself is cased. |
| // |
| //------------------------------------------------------------------------------ |
| void RegexCompile::emitONE_CHAR(UChar32 c) { |
| int32_t op; |
| if ((fModeFlags & UREGEX_CASE_INSENSITIVE) && |
| u_hasBinaryProperty(c, UCHAR_CASE_SENSITIVE)) { |
| // We have a cased character, and are in case insensitive matching mode. |
| c = u_foldCase(c, U_FOLD_CASE_DEFAULT); |
| op = URX_BUILD(URX_ONECHAR_I, c); |
| } else { |
| // Uncased char, or case sensitive match mode. |
| // Either way, just generate a literal compare of the char. |
| op = URX_BUILD(URX_ONECHAR, c); |
| } |
| fRXPat->fCompiledPat->addElement(op, *fStatus); |
| } |
| |
| |
| //------------------------------------------------------------------------------ |
| // |
| // fixLiterals When compiling something that can follow a literal |
| // string in a pattern, we need to "fix" any preceding |
| // string, which will cause any subsequent literals to |
| // begin a new string, rather than appending to the |
| // old one. |
| // |
| // Optionally, split the last char of the string off into |
| // a single "ONE_CHAR" operation, so that quantifiers can |
| // apply to that char alone. Example: abc* |
| // The * must apply to the 'c' only. |
| // |
| //------------------------------------------------------------------------------ |
| void RegexCompile::fixLiterals(UBool split) { |
| int32_t stringStart = fStringOpStart; // start index of the current literal string |
| int32_t op; // An op from/for the compiled pattern. |
| int32_t opType; // An opcode type from the compiled pattern. |
| int32_t stringLastCharIdx; |
| UChar32 lastChar; |
| int32_t stringNextToLastCharIdx; |
| UChar32 nextToLastChar; |
| int32_t stringLen; |
| |
| fStringOpStart = -1; |
| if (!split) { |
| return; |
| } |
| |
| // Split: We need to ensure that the last item in the compiled pattern does |
| // not refer to a literal string of more than one char. If it does, |
| // separate the last char from the rest of the string. |
| |
| // If the last operation from the compiled pattern is not a string, |
| // nothing needs to be done |
| op = fRXPat->fCompiledPat->lastElementi(); |
| opType = URX_TYPE(op); |
| if (opType != URX_STRING_LEN) { |
| return; |
| } |
| stringLen = URX_VAL(op); |
| |
| // |
| // Find the position of the last code point in the string (might be a surrogate pair) |
| // |
| stringLastCharIdx = fRXPat->fLiteralText.length(); |
| stringLastCharIdx = fRXPat->fLiteralText.moveIndex32(stringLastCharIdx, -1); |
| lastChar = fRXPat->fLiteralText.char32At(stringLastCharIdx); |
| |
| // The string should always be at least two code points long, meaning that there |
| // should be something before the last char position that we just found. |
| U_ASSERT(stringLastCharIdx > stringStart); |
| stringNextToLastCharIdx = fRXPat->fLiteralText.moveIndex32(stringLastCharIdx, -1); |
| U_ASSERT(stringNextToLastCharIdx >= stringStart); |
| nextToLastChar = fRXPat->fLiteralText.char32At(stringNextToLastCharIdx); |
| |
| if (stringNextToLastCharIdx > stringStart) { |
| // The length of string remaining after removing one char is two or more. |
| // Leave the string in the compiled pattern, shorten it by one char, |
| // and append a URX_ONECHAR op for the last char. |
| stringLen -= (fRXPat->fLiteralText.length() - stringLastCharIdx); |
| op = URX_BUILD(URX_STRING_LEN, stringLen); |
| fRXPat->fCompiledPat->setElementAt(op, fRXPat->fCompiledPat->size() -1); |
| emitONE_CHAR(lastChar); |
| } else { |
| // The original string consisted of exactly two characters. Replace |
| // the existing compiled URX_STRING/URX_STRING_LEN ops with a pair |
| // of URX_ONECHARs. |
| fRXPat->fCompiledPat->setSize(fRXPat->fCompiledPat->size() -2); |
| emitONE_CHAR(nextToLastChar); |
| emitONE_CHAR(lastChar); |
| } |
| } |
| |
| |
| |
| |
| |
| |
| //------------------------------------------------------------------------------ |
| // |
| // insertOp() Insert a slot for a new opcode into the already |
| // compiled pattern code. |
| // |
| // Fill the slot with a NOP. Our caller will replace it |
| // with what they really wanted. |
| // |
| //------------------------------------------------------------------------------ |
| void RegexCompile::insertOp(int32_t where) { |
| UVector32 *code = fRXPat->fCompiledPat; |
| U_ASSERT(where>0 && where < code->size()); |
| |
| int32_t nop = URX_BUILD(URX_NOP, 0); |
| code->insertElementAt(nop, where, *fStatus); |
| |
| // Walk through the pattern, looking for any ops with targets that |
| // were moved down by the insert. Fix them. |
| int32_t loc; |
| for (loc=0; loc<code->size(); loc++) { |
| int32_t op = code->elementAti(loc); |
| int32_t opType = URX_TYPE(op); |
| int32_t opValue = URX_VAL(op); |
| if ((opType == URX_JMP || |
| opType == URX_JMPX || |
| opType == URX_STATE_SAVE || |
| opType == URX_CTR_LOOP || |
| opType == URX_CTR_LOOP_NG || |
| opType == URX_JMP_SAV || |
| opType == URX_RELOC_OPRND) && opValue > where) { |
| // Target location for this opcode is after the insertion point and |
| // needs to be incremented to adjust for the insertion. |
| opValue++; |
| op = URX_BUILD(opType, opValue); |
| code->setElementAt(op, loc); |
| } |
| } |
| |
| // Now fix up the parentheses stack. All positive values in it are locations in |
| // the compiled pattern. (Negative values are frame boundaries, and don't need fixing.) |
| for (loc=0; loc<fParenStack.size(); loc++) { |
| int32_t x = fParenStack.elementAti(loc); |
| if (x>where) { |
| x++; |
| fParenStack.setElementAt(x, loc); |
| } |
| } |
| |
| if (fMatchCloseParen > where) { |
| fMatchCloseParen++; |
| } |
| if (fMatchOpenParen > where) { |
| fMatchOpenParen++; |
| } |
| } |
| |
| |
| |
| //------------------------------------------------------------------------------ |
| // |
| // blockTopLoc() Find or create a location in the compiled pattern |
| // at the start of the operation or block that has |
| // just been compiled. Needed when a quantifier (* or |
| // whatever) appears, and we need to add an operation |
| // at the start of the thing being quantified. |
| // |
| // (Parenthesized Blocks) have a slot with a NOP that |
| // is reserved for this purpose. .* or similar don't |
| // and a slot needs to be added. |
| // |
| // parameter reserveLoc : TRUE - ensure that there is space to add an opcode |
| // at the returned location. |
| // FALSE - just return the address, |
| // do not reserve a location there. |
| // |
| //------------------------------------------------------------------------------ |
| int32_t RegexCompile::blockTopLoc(UBool reserveLoc) { |
| int32_t theLoc; |
| if (fRXPat->fCompiledPat->size() == fMatchCloseParen) |
| { |
| // The item just processed is a parenthesized block. |
| theLoc = fMatchOpenParen; // A slot is already reserved for us. |
| U_ASSERT(theLoc > 0); |
| uint32_t opAtTheLoc = fRXPat->fCompiledPat->elementAti(theLoc); |
| U_ASSERT(URX_TYPE(opAtTheLoc) == URX_NOP); |
| } |
| else { |
| // Item just compiled is a single thing, a ".", or a single char, or a set reference. |
| // No slot for STATE_SAVE was pre-reserved in the compiled code. |
| // We need to make space now. |
| fixLiterals(TRUE); // If last item was a string, separate the last char. |
| theLoc = fRXPat->fCompiledPat->size()-1; |
| if (reserveLoc) { |
| int32_t opAtTheLoc = fRXPat->fCompiledPat->elementAti(theLoc); |
| int32_t nop = URX_BUILD(URX_NOP, 0); |
| fRXPat->fCompiledPat->insertElementAt(nop, theLoc, *fStatus); |
| } |
| } |
| return theLoc; |
| } |
| |
| |
| |
| //------------------------------------------------------------------------------ |
| // |
| // handleCloseParen When compiling a close paren, we need to go back |
| // and fix up any JMP or SAVE operations within the |
| // parenthesized block that need to target the end |
| // of the block. The locations of these are kept on |
| // the paretheses stack. |
| // |
| // This function is called both when encountering a |
| // real ) and at the end of the pattern. |
| // |
| //------------------------------------------------------------------------------- |
| void RegexCompile::handleCloseParen() { |
| int32_t patIdx; |
| int32_t patOp; |
| if (fParenStack.size() <= 0) { |
| error(U_REGEX_MISMATCHED_PAREN); |
| return; |
| } |
| |
| // Force any literal chars that may follow the close paren to start a new string, |
| // and not attach to any preceding it. |
| fixLiterals(FALSE); |
| |
| // Fixup any operations within the just-closed parenthesized group |
| // that need to reference the end of the (block). |
| // (The first one popped from the stack is an unused slot for |
| // alternation (OR) state save, but applying the fixup to it does no harm.) |
| for (;;) { |
| patIdx = fParenStack.popi(); |
| if (patIdx < 0) { |
| // value < 0 flags the start of the frame on the paren stack. |
| break; |
| } |
| U_ASSERT(patIdx>0 && patIdx <= fRXPat->fCompiledPat->size()); |
| patOp = fRXPat->fCompiledPat->elementAti(patIdx); |
| U_ASSERT(URX_VAL(patOp) == 0); // Branch target for JMP should not be set. |
| patOp |= fRXPat->fCompiledPat->size(); // Set it now. |
| fRXPat->fCompiledPat->setElementAt(patOp, patIdx); |
| fMatchOpenParen = patIdx; |
| } |
| |
| // At the close of any parenthesized block, restore the match mode flags to |
| // the value they had at the open paren. Saved value is |
| // at the top of the paren stack. |
| fModeFlags = fParenStack.popi(); |
| |
| // DO any additional fixups, depending on the specific kind of |
| // parentesized grouping this is |
| |
| switch (patIdx) { |
| case plain: |
| case flags: |
| // No additional fixups required. |
| // (Grouping-only parentheses) |
| break; |
| case capturing: |
| // Capturing Parentheses. |
| // Insert a End Capture op into the pattern. |
| // The frame offset of the variables for this cg is obtained from the |
| // start capture op and put it into the end-capture op. |
| { |
| int32_t captureOp = fRXPat->fCompiledPat->elementAti(fMatchOpenParen+1); |
| U_ASSERT(URX_TYPE(captureOp) == URX_START_CAPTURE); |
| |
| int32_t frameVarLocation = URX_VAL(captureOp); |
| int32_t endCaptureOp = URX_BUILD(URX_END_CAPTURE, frameVarLocation); |
| fRXPat->fCompiledPat->addElement(endCaptureOp, *fStatus); |
| } |
| break; |
| case atomic: |
| // Atomic Parenthesis. |
| // Insert a LD_SP operation to restore the state stack to the position |
| // it was when the atomic parens were entered. |
| { |
| int32_t stoOp = fRXPat->fCompiledPat->elementAti(fMatchOpenParen+1); |
| U_ASSERT(URX_TYPE(stoOp) == URX_STO_SP); |
| int32_t stoLoc = URX_VAL(stoOp); |
| int32_t ldOp = URX_BUILD(URX_LD_SP, stoLoc); |
| fRXPat->fCompiledPat->addElement(ldOp, *fStatus); |
| } |
| break; |
| |
| case lookAhead: |
| { |
| int32_t startOp = fRXPat->fCompiledPat->elementAti(fMatchOpenParen-1); |
| U_ASSERT(URX_TYPE(startOp) == URX_LA_START); |
| int32_t dataLoc = URX_VAL(startOp); |
| int32_t op = URX_BUILD(URX_LA_END, dataLoc); |
| fRXPat->fCompiledPat->addElement(op, *fStatus); |
| } |
| break; |
| |
| case negLookAhead: |
| { |
| // See comment at doOpenLookAheadNeg |
| int32_t startOp = fRXPat->fCompiledPat->elementAti(fMatchOpenParen-1); |
| U_ASSERT(URX_TYPE(startOp) == URX_LA_START); |
| int32_t dataLoc = URX_VAL(startOp); |
| int32_t op = URX_BUILD(URX_LA_END, dataLoc); |
| fRXPat->fCompiledPat->addElement(op, *fStatus); |
| op = URX_BUILD(URX_FAIL, 0); |
| fRXPat->fCompiledPat->addElement(op, *fStatus); |
| |
| // Patch the URX_SAVE near the top of the block. |
| int32_t saveOp = fRXPat->fCompiledPat->elementAti(fMatchOpenParen); |
| U_ASSERT(URX_TYPE(saveOp) == URX_STATE_SAVE); |
| int32_t dest = fRXPat->fCompiledPat->size(); |
| saveOp = URX_BUILD(URX_STATE_SAVE, dest); |
| fRXPat->fCompiledPat->setElementAt(saveOp, fMatchOpenParen); |
| } |
| break; |
| |
| case lookBehind: |
| { |
| // See comment at doOpenLookBehind. |
| |
| // Append the URX_LB_END and URX_LA_END to the compiled pattern. |
| int32_t startOp = fRXPat->fCompiledPat->elementAti(fMatchOpenParen-4); |
| U_ASSERT(URX_TYPE(startOp) == URX_LB_START); |
| int32_t dataLoc = URX_VAL(startOp); |
| int32_t op = URX_BUILD(URX_LB_END, dataLoc); |
| fRXPat->fCompiledPat->addElement(op, *fStatus); |
| op = URX_BUILD(URX_LA_END, dataLoc); |
| fRXPat->fCompiledPat->addElement(op, *fStatus); |
| |
| // Determine the min and max bounds for the length of the |
| // string that the pattern can match. |
| // An unbounded upper limit is an error. |
| int32_t patEnd = fRXPat->fCompiledPat->size() - 1; |
| int32_t minML = minMatchLength(fMatchOpenParen, patEnd); |
| int32_t maxML = maxMatchLength(fMatchOpenParen, patEnd); |
| if (maxML == INT32_MAX) { |
| error(U_REGEX_LOOK_BEHIND_LIMIT); |
| break; |
| } |
| U_ASSERT(minML <= maxML); |
| |
| // Insert the min and max match len bounds into the URX_LB_CONT op that |
| // appears at the top of the look-behind block, at location fMatchOpenParen+1 |
| fRXPat->fCompiledPat->setElementAt(minML, fMatchOpenParen-2); |
| fRXPat->fCompiledPat->setElementAt(maxML, fMatchOpenParen-1); |
| |
| } |
| break; |
| |
| |
| |
| case lookBehindN: |
| { |
| // See comment at doOpenLookBehindNeg. |
| |
| // Append the URX_LBN_END to the compiled pattern. |
| int32_t startOp = fRXPat->fCompiledPat->elementAti(fMatchOpenParen-5); |
| U_ASSERT(URX_TYPE(startOp) == URX_LB_START); |
| int32_t dataLoc = URX_VAL(startOp); |
| int32_t op = URX_BUILD(URX_LBN_END, dataLoc); |
| fRXPat->fCompiledPat->addElement(op, *fStatus); |
| |
| // Determine the min and max bounds for the length of the |
| // string that the pattern can match. |
| // An unbounded upper limit is an error. |
| int32_t patEnd = fRXPat->fCompiledPat->size() - 1; |
| int32_t minML = minMatchLength(fMatchOpenParen, patEnd); |
| int32_t maxML = maxMatchLength(fMatchOpenParen, patEnd); |
| if (maxML == INT32_MAX) { |
| error(U_REGEX_LOOK_BEHIND_LIMIT); |
| break; |
| } |
| U_ASSERT(minML <= maxML); |
| |
| // Insert the min and max match len bounds into the URX_LB_CONT op that |
| // appears at the top of the look-behind block, at location fMatchOpenParen+1 |
| fRXPat->fCompiledPat->setElementAt(minML, fMatchOpenParen-3); |
| fRXPat->fCompiledPat->setElementAt(maxML, fMatchOpenParen-2); |
| |
| // Insert the pattern location to continue at after a successful match |
| // as the last operand of the URX_LBN_CONT |
| op = URX_BUILD(URX_RELOC_OPRND, fRXPat->fCompiledPat->size()); |
| fRXPat->fCompiledPat->setElementAt(op, fMatchOpenParen-1); |
| } |
| break; |
| |
| |
| |
| default: |
| U_ASSERT(FALSE); |
| } |
| |
| // remember the next location in the compiled pattern. |
| // The compilation of Quantifiers will look at this to see whether its looping |
| // over a parenthesized block or a single item |
| fMatchCloseParen = fRXPat->fCompiledPat->size(); |
| } |
| |
| |
| |
| //---------------------------------------------------------------------------------------- |
| // |
| // compileSet Compile the pattern operations for a reference to a |
| // UnicodeSet. |
| // |
| //---------------------------------------------------------------------------------------- |
| void RegexCompile::compileSet(UnicodeSet *theSet) |
| { |
| if (theSet == NULL) { |
| return; |
| } |
| int32_t setSize = theSet->size(); |
| UChar32 firstSetChar = theSet->charAt(0); |
| if (firstSetChar == -1) { |
| // Sets that contain only strings, but no individual chars, |
| // will end up here. |
| error(U_REGEX_SET_CONTAINS_STRING); |
| setSize = 0; |
| } |
| |
| switch (setSize) { |
| case 0: |
| { |
| // Set of no elements. Always fails to match. |
| fRXPat->fCompiledPat->addElement(URX_BUILD(URX_BACKTRACK, 0), *fStatus); |
| delete theSet; |
| } |
| break; |
| |
| case 1: |
| { |
| // The set contains only a single code point. Put it into |
| // the compiled pattern as a single char operation rather |
| // than a set, and discard the set itself. |
| literalChar(firstSetChar); |
| delete theSet; |
| } |
| break; |
| |
| default: |
| { |
| // The set contains two or more chars. (the normal case) |
| // Put it into the compiled pattern as a set. |
| int32_t setNumber = fRXPat->fSets->size(); |
| fRXPat->fSets->addElement(theSet, *fStatus); |
| int32_t setOp = URX_BUILD(URX_SETREF, setNumber); |
| fRXPat->fCompiledPat->addElement(setOp, *fStatus); |
| } |
| } |
| } |
| |
| |
| //---------------------------------------------------------------------------------------- |
| // |
| // compileInterval Generate the code for a {min, max} style interval quantifier. |
| // Except for the specific opcodes used, the code is the same |
| // for all three types (greedy, non-greedy, possessive) of |
| // intervals. The opcodes are supplied as parameters. |
| // |
| // The code for interval loops has this form: |
| // 0 CTR_INIT counter loc (in stack frame) |
| // 1 5 patt address of CTR_LOOP at bottom of block |
| // 2 min count |
| // 3 max count (-1 for unbounded) |
| // 4 ... block to be iterated over |
| // 5 CTR_LOOP |
| // |
| // In |
| //---------------------------------------------------------------------------------------- |
| void RegexCompile::compileInterval(int32_t InitOp, int32_t LoopOp) |
| { |
| // The CTR_INIT op at the top of the block with the {n,m} quantifier takes |
| // four slots in the compiled code. Reserve them. |
| int32_t topOfBlock = blockTopLoc(TRUE); |
| insertOp(topOfBlock); |
| insertOp(topOfBlock); |
| insertOp(topOfBlock); |
| |
| // The operands for the CTR_INIT opcode include the index in the matcher data |
| // of the counter. Allocate it now. |
| int32_t counterLoc = fRXPat->fFrameSize; |
| fRXPat->fFrameSize++; |
| |
| int32_t op = URX_BUILD(InitOp, counterLoc); |
| fRXPat->fCompiledPat->setElementAt(op, topOfBlock); |
| |
| // The second operand of CTR_INIT is the location following the end of the loop. |
| // Must put in as a URX_RELOC_OPRND so that the value will be adjusted if the |
| // compilation of something later on causes the code to grow and the target |
| // position to move. |
| int32_t loopEnd = fRXPat->fCompiledPat->size(); |
| op = URX_BUILD(URX_RELOC_OPRND, loopEnd); |
| fRXPat->fCompiledPat->setElementAt(op, topOfBlock+1); |
| |
| // Followed by the min and max counts. |
| fRXPat->fCompiledPat->setElementAt(fIntervalLow, topOfBlock+2); |
| fRXPat->fCompiledPat->setElementAt(fIntervalUpper, topOfBlock+3); |
| |
| // Apend the CTR_LOOP op. The operand is the location of the CTR_INIT op. |
| // Goes at end of the block being looped over, so just append to the code so far. |
| op = URX_BUILD(LoopOp, topOfBlock); |
| fRXPat->fCompiledPat->addElement(op, *fStatus); |
| |
| if (fIntervalLow > fIntervalUpper && fIntervalUpper != -1) { |
| error(U_REGEX_MAX_LT_MIN); |
| } |
| |
| |
| |
| } |
| |
| |
| |
| UBool RegexCompile::compileInlineInterval() { |
| if (fIntervalUpper > 10 || fIntervalUpper < fIntervalLow) { |
| // Too big to inline. Fail, which will cause looping code to be generated. |
| // (Upper < Lower picks up unbounded upper and errors, both.) |
| return FALSE; |
| } |
| |
| int32_t topOfBlock = blockTopLoc(FALSE); |
| if (fIntervalUpper == 0) { |
| // Pathological case. Attempt no matches, as if the block doesn't exist. |
| fRXPat->fCompiledPat->setSize(topOfBlock); |
| return TRUE; |
| } |
| |
| if (topOfBlock != fRXPat->fCompiledPat->size()-1 && fIntervalUpper != 1) { |
| // The thing being repeated is not a single op, but some |
| // more complex block. Do it as a loop, not inlines. |
| // Note that things "repeated" a max of once are handled as inline, because |
| // the one copy of the code already generated is just fine. |
| return FALSE; |
| } |
| |
| // Pick up the opcode that is to be repeated |
| // |
| int32_t op = fRXPat->fCompiledPat->elementAti(topOfBlock); |
| |
| // Compute the pattern location where the inline sequence |
| // will end, and set up the state save op that will be needed. |
| // |
| int32_t endOfSequenceLoc = fRXPat->fCompiledPat->size()-1 |
| + fIntervalUpper + (fIntervalUpper-fIntervalLow); |
| int32_t saveOp = URX_BUILD(URX_STATE_SAVE, endOfSequenceLoc); |
| if (fIntervalLow == 0) { |
| insertOp(topOfBlock); |
| fRXPat->fCompiledPat->setElementAt(saveOp, topOfBlock); |
| } |
| |
| |
| |
| // Loop, emitting the op for the thing being repeated each time. |
| // Loop starts at 1 because one instance of the op already exists in the pattern, |
| // it was put there when it was originally encountered. |
| int32_t i; |
| for (i=1; i<fIntervalUpper; i++ ) { |
| if (i == fIntervalLow) { |
| fRXPat->fCompiledPat->addElement(saveOp, *fStatus); |
| } |
| if (i > fIntervalLow) { |
| fRXPat->fCompiledPat->addElement(saveOp, *fStatus); |
| } |
| fRXPat->fCompiledPat->addElement(op, *fStatus); |
| } |
| return TRUE; |
| } |
| |
| |
| |
| //---------------------------------------------------------------------------------------- |
| // |
| // matchStartType Determine how a match can start. |
| // Used to optimize find() operations. |
| // |
| // Operation is very similar to minMatchLength(). Walk the compiled |
| // pattern, keeping an on-going minimum-match-length. For any |
| // op where the min match coming in is zero, add that ops possible |
| // starting matches to the possible starts for the overall pattern. |
| // |
| //---------------------------------------------------------------------------------------- |
| void RegexCompile::matchStartType() { |
| if (U_FAILURE(*fStatus)) { |
| return; |
| } |
| |
| |
| int32_t loc; // Location in the pattern of the current op being processed. |
| int32_t op; // The op being processed |
| int32_t opType; // The opcode type of the op |
| int32_t currentLen = 0; // Minimum length of a match to this point (loc) in the pattern |
| int32_t numInitialStrings = 0; // Number of strings encountered that could match at start. |
| |
| UBool atStart = TRUE; // True if no part of the pattern yet encountered |
| // could have advanced the position in a match. |
| // (Maximum match length so far == 0) |
| |
| // forwardedLength is a vector holding minimum-match-length values that |
| // are propagated forward in the pattern by JMP or STATE_SAVE operations. |
| // It must be one longer than the pattern being checked because some ops |
| // will jmp to a end-of-block+1 location from within a block, and we must |
| // count those when checking the block. |
| int32_t end = fRXPat->fCompiledPat->size(); |
| UVector32 forwardedLength(end+1, *fStatus); |
| forwardedLength.setSize(end+1); |
| for (loc=3; loc<end; loc++) { |
| forwardedLength.setElementAt(INT32_MAX, loc); |
| } |
| |
| for (loc = 3; loc<end; loc++) { |
| op = fRXPat->fCompiledPat->elementAti(loc); |
| opType = URX_TYPE(op); |
| |
| // The loop is advancing linearly through the pattern. |
| // If the op we are now at was the destination of a branch in the pattern, |
| // and that path has a shorter minimum length than the current accumulated value, |
| // replace the current accumulated value. |
| U_ASSERT(currentLen>=0 && currentLen < INT32_MAX); |
| if (forwardedLength.elementAti(loc) < currentLen) { |
| currentLen = forwardedLength.elementAti(loc); |
| U_ASSERT(currentLen>=0 && currentLen < INT32_MAX); |
| } |
| |
| switch (opType) { |
| // Ops that don't change the total length matched |
| case URX_RESERVED_OP: |
| case URX_END: |
| case URX_STRING_LEN: |
| case URX_NOP: |
| case URX_START_CAPTURE: |
| case URX_END_CAPTURE: |
| case URX_BACKSLASH_B: |
| case URX_BACKSLASH_BU: |
| case URX_BACKSLASH_G: |
| case URX_BACKSLASH_Z: |
| case URX_DOLLAR: |
| case URX_RELOC_OPRND: |
| case URX_STO_INP_LOC: |
| case URX_DOLLAR_M: |
| case URX_BACKTRACK: |
| case URX_BACKREF: // BackRef. Must assume that it might be a zero length match |
| case URX_BACKREF_I: |
| |
| case URX_STO_SP: // Setup for atomic or possessive blocks. Doesn't change what can match. |
| case URX_LD_SP: |
| break; |
| |
| case URX_CARET: |
| if (atStart) { |
| fRXPat->fStartType = START_START; |
| } |
| break; |
| |
| case URX_CARET_M: |
| if (atStart) { |
| fRXPat->fStartType = START_LINE; |
| } |
| break; |
| |
| case URX_ONECHAR: |
| if (currentLen == 0) { |
| // This character could appear at the start of a match. |
| // Add it to the set of possible starting characters. |
| fRXPat->fInitialChars->add(URX_VAL(op)); |
| numInitialStrings += 2; |
| } |
| currentLen++; |
| atStart = FALSE; |
| break; |
| |
| |
| case URX_SETREF: |
| if (currentLen == 0) { |
| int32_t sn = URX_VAL(op); |
| U_ASSERT(sn > 0 && sn < fRXPat->fSets->size()); |
| const UnicodeSet *s = (UnicodeSet *)fRXPat->fSets->elementAt(sn); |
| fRXPat->fInitialChars->addAll(*s); |
| numInitialStrings += 2; |
| } |
| currentLen++; |
| atStart = FALSE; |
| break; |
| |
| case URX_LOOP_SR_I: |
| // [Set]*, like a SETREF, above, in what it can match, |
| // but may not match at all, so currentLen is not incremented. |
| if (currentLen == 0) { |
| int32_t sn = URX_VAL(op); |
| U_ASSERT(sn > 0 && sn < fRXPat->fSets->size()); |
| const UnicodeSet *s = (UnicodeSet *)fRXPat->fSets->elementAt(sn); |
| fRXPat->fInitialChars->addAll(*s); |
| numInitialStrings += 2; |
| } |
| atStart = FALSE; |
| break; |
| |
| case URX_LOOP_DOT_I: |
| if (currentLen == 0) { |
| // .* at the start of a pattern. |
| // Any character can begin the match. |
| fRXPat->fInitialChars->clear(); |
| fRXPat->fInitialChars->complement(); |
| numInitialStrings += 2; |
| } |
| atStart = FALSE; |
| break; |
| |
| |
| case URX_STATIC_SETREF: |
| if (currentLen == 0) { |
| int32_t sn = URX_VAL(op); |
| U_ASSERT(sn>0 && sn<URX_LAST_SET); |
| const UnicodeSet *s = fRXPat->fStaticSets[sn]; |
| fRXPat->fInitialChars->addAll(*s); |
| numInitialStrings += 2; |
| } |
| currentLen++; |
| atStart = FALSE; |
| break; |
| |
| |
| |
| case URX_STAT_SETREF_N: |
| if (currentLen == 0) { |
| int32_t sn = URX_VAL(op); |
| const UnicodeSet *s = fRXPat->fStaticSets[sn]; |
| UnicodeSet sc(*s); |
| sc.complement(); |
| fRXPat->fInitialChars->addAll(sc); |
| numInitialStrings += 2; |
| } |
| currentLen++; |
| atStart = FALSE; |
| break; |
| |
| |
| |
| case URX_BACKSLASH_D: |
| // Digit Char |
| if (currentLen == 0) { |
| UnicodeSet s; |
| s.applyIntPropertyValue(UCHAR_GENERAL_CATEGORY_MASK, U_GC_ND_MASK, *fStatus); |
| if (URX_VAL(op) != 0) { |
| s.complement(); |
| } |
| fRXPat->fInitialChars->addAll(s); |
| numInitialStrings += 2; |
| } |
| currentLen++; |
| atStart = FALSE; |
| break; |
| |
| |
| case URX_ONECHAR_I: |
| // Case Insensitive Single Character. |
| if (currentLen == 0) { |
| UChar32 c = URX_VAL(op); |
| if (u_hasBinaryProperty(c, UCHAR_CASE_SENSITIVE)) { |
| // character may have distinct cased forms. Add all of them |
| // to the set of possible starting match chars. |
| UnicodeSet s(c, c); |
| s.closeOver(USET_CASE); |
| fRXPat->fInitialChars->addAll(s); |
| } else { |
| // Char has no case variants. Just add it as-is to the |
| // set of possible starting chars. |
| fRXPat->fInitialChars->add(c); |
| } |
| numInitialStrings += 2; |
| } |
| currentLen++; |
| atStart = FALSE; |
| break; |
| |
| |
| case URX_BACKSLASH_X: // Grahpeme Cluster. Minimum is 1, max unbounded. |
| case URX_DOTANY_ALL: // . matches one or two. |
| case URX_DOTANY: |
| case URX_DOTANY_ALL_PL: |
| case URX_DOTANY_PL: |
| if (currentLen == 0) { |
| // These constructs are all bad news when they appear at the start |
| // of a match. Any character can begin the match. |
| fRXPat->fInitialChars->clear(); |
| fRXPat->fInitialChars->complement(); |
| numInitialStrings += 2; |
| } |
| currentLen++; |
| atStart = FALSE; |
| break; |
| |
| |
| case URX_JMPX: |
| loc++; // Except for extra operand on URX_JMPX, same as URX_JMP. |
| case URX_JMP: |
| { |
| int32_t jmpDest = URX_VAL(op); |
| if (jmpDest < loc) { |
| // Loop of some kind. Can safely ignore, the worst that will happen |
| // is that we understate the true minimum length |
| currentLen = forwardedLength.elementAti(loc+1); |
| |
| } else { |
| // Forward jump. Propagate the current min length to the target loc of the jump. |
| U_ASSERT(jmpDest <= end+1); |
| if (forwardedLength.elementAti(jmpDest) > currentLen) { |
| forwardedLength.setElementAt(currentLen, jmpDest); |
| } |
| } |
| } |
| atStart = FALSE; |
| break; |
| |
| case URX_JMP_SAV: |
| case URX_JMP_SAV_X: |
| // Combo of state save to the next loc, + jmp backwards. |
| // Net effect on min. length computation is nothing. |
| atStart = FALSE; |
| break; |
| |
| case URX_FAIL: |
| // Fails are kind of like a branch, except that the min length was |
| // propagated already, by the state save. |
| currentLen = forwardedLength.elementAti(loc+1); |
| atStart = FALSE; |
| break; |
| |
| |
| case URX_STATE_SAVE: |
| { |
| // State Save, for forward jumps, propagate the current minimum. |
| // of the state save. |
| int32_t jmpDest = URX_VAL(op); |
| if (jmpDest > loc) { |
| if (currentLen < forwardedLength.elementAti(jmpDest)) { |
| forwardedLength.setElementAt(currentLen, jmpDest); |
| } |
| } |
| } |
| atStart = FALSE; |
| break; |
| |
| |
| |
| |
| case URX_STRING: |
| { |
| loc++; |
| int32_t stringLenOp = fRXPat->fCompiledPat->elementAti(loc); |
| int32_t stringLen = URX_VAL(stringLenOp); |
| U_ASSERT(URX_TYPE(stringLenOp) == URX_STRING_LEN); |
| U_ASSERT(stringLenOp >= 2); |
| if (currentLen == 0) { |
| // Add the starting character of this string to the set of possible starting |
| // characters for this pattern. |
| int32_t stringStartIdx = URX_VAL(op); |
| UChar32 c = fRXPat->fLiteralText.char32At(stringStartIdx); |
| fRXPat->fInitialChars->add(c); |
| |
| // Remember this string. After the entire pattern has been checked, |
| // if nothing else is identified that can start a match, we'll use it. |
| numInitialStrings++; |
| fRXPat->fInitialStringIdx = stringStartIdx; |
| fRXPat->fInitialStringLen = stringLen; |
| } |
| |
| currentLen += stringLen; |
| atStart = FALSE; |
| } |
| break; |
| |
| case URX_STRING_I: |
| { |
| // Case-insensitive string. Unlike exact-match strings, we won't |
| // attempt a string search for possible match positions. But we |
| // do update the set of possible starting characters. |
| loc++; |
| int32_t stringLenOp = fRXPat->fCompiledPat->elementAti(loc); |
| int32_t stringLen = URX_VAL(stringLenOp); |
| U_ASSERT(URX_TYPE(stringLenOp) == URX_STRING_LEN); |
| U_ASSERT(stringLenOp >= 2); |
| if (currentLen == 0) { |
| // Add the starting character of this string to the set of possible starting |
| // characters for this pattern. |
| int32_t stringStartIdx = URX_VAL(op); |
| UChar32 c = fRXPat->fLiteralText.char32At(stringStartIdx); |
| UnicodeSet s(c, c); |
| s.closeOver(USET_CASE); |
| fRXPat->fInitialChars->addAll(s); |
| numInitialStrings += 2; // Matching on an initial string not possible. |
| } |
| currentLen += stringLen; |
| atStart = FALSE; |
| } |
| break; |
| |
| case URX_CTR_INIT: |
| case URX_CTR_INIT_NG: |
| { |
| // Loop Init Ops. These don't change the min length, but they are 4 word ops |
| // so location must be updated accordingly. |
| // Loop Init Ops. |
| // If the min loop count == 0 |
| // move loc forwards to the end of the loop, skipping over the body. |
| // If the min count is > 0, |
| // continue normal processing of the body of the loop. |
| int32_t loopEndLoc = fRXPat->fCompiledPat->elementAti(loc+1); |
| loopEndLoc = URX_VAL(loopEndLoc); |
| int32_t minLoopCount = fRXPat->fCompiledPat->elementAti(loc+2); |
| if (minLoopCount == 0) { |
| // Min Loop Count of 0, treat like a forward branch and |
| // move the current minimum length up to the target |
| // (end of loop) location. |
| U_ASSERT(loopEndLoc <= end+1); |
| if (forwardedLength.elementAti(loopEndLoc) > currentLen) { |
| forwardedLength.setElementAt(currentLen, loopEndLoc); |
| } |
| } |
| loc+=3; // Skips over operands of CTR_INIT |
| } |
| atStart = FALSE; |
| break; |
| |
| |
| case URX_CTR_LOOP: |
| case URX_CTR_LOOP_NG: |
| // Loop ops. |
| // The jump is conditional, backwards only. |
| atStart = FALSE; |
| break; |
| |
| case URX_LOOP_C: |
| // More loop ops. These state-save to themselves. |
| // don't change the minimum match |
| atStart = FALSE; |
| break; |
| |
| |
| case URX_LA_START: |
| case URX_LB_START: |
| { |
| // Look-around. Scan forward until the matching look-ahead end, |
| // without processing the look-around block. This is overly pessimistic. |
| int32_t depth = 0; |
| for (;;) { |
| loc++; |
| op = fRXPat->fCompiledPat->elementAti(loc); |
| if (URX_TYPE(op) == URX_LA_START || URX_TYPE(op) == URX_LB_START) { |
| depth++; |
| } |
| if (URX_TYPE(op) == URX_LA_END || URX_TYPE(op)==URX_LBN_END) { |
| if (depth == 0) { |
| break; |
| } |
| depth--; |
| } |
| if (URX_TYPE(op) == URX_STATE_SAVE) { |
| // Need this because neg lookahead blocks will FAIL to outside |
| // of the block. |
| int32_t jmpDest = URX_VAL(op); |
| if (jmpDest > loc) { |
| if (currentLen < forwardedLength.elementAti(jmpDest)) { |
| forwardedLength.setElementAt(currentLen, jmpDest); |
| } |
| } |
| } |
| U_ASSERT(loc <= end); |
| } |
| } |
| break; |
| |
| case URX_LA_END: |
| case URX_LB_CONT: |
| case URX_LB_END: |
| case URX_LBN_CONT: |
| case URX_LBN_END: |
| U_ASSERT(FALSE); // Shouldn't get here. These ops should be |
| // consumed by the scan in URX_LA_START and LB_START |
| |
| break; |
| |
| default: |
| U_ASSERT(FALSE); |
| } |
| |
| } |
| |
| |
| // We have finished walking through the ops. Check whether some forward jump |
| // propagated a shorter length to location end+1. |
| if (forwardedLength.elementAti(end+1) < currentLen) { |
| currentLen = forwardedLength.elementAti(end+1); |
| } |
| |
| |
| fRXPat->fInitialChars8->init(fRXPat->fInitialChars); |
| |
| |
| // Sort out what we should check for when looking for candidate match start positions. |
| // In order of preference, |
| // 1. Start of input text buffer. |
| // 2. A literal string. |
| // 3. Start of line in multi-line mode. |
| // 4. A single literal character. |
| // 5. A character from a set of characters. |
| // |
| if (fRXPat->fStartType == START_START) { |
| // Match only at the start of an input text string. |
| // start type is already set. We're done. |
| } else if (numInitialStrings == 1 && fRXPat->fMinMatchLen > 0) { |
| // Match beginning only with a literal string. |
| UChar32 c = fRXPat->fLiteralText.char32At(fRXPat->fInitialStringIdx); |
| U_ASSERT(fRXPat->fInitialChars->contains(c)); |
| fRXPat->fStartType = START_STRING; |
| fRXPat->fInitialChar = c; |
| } else if (fRXPat->fStartType == START_LINE) { |
| // Match at start of line in Multi-Line mode. |
| // Nothing to do here; everything is already set. |
| } else if (fRXPat->fMinMatchLen == 0) { |
| // Zero length match possible. We could start anywhere. |
| fRXPat->fStartType = START_NO_INFO; |
| } else if (fRXPat->fInitialChars->size() == 1) { |
| // All matches begin with the same char. |
| fRXPat->fStartType = START_CHAR; |
| fRXPat->fInitialChar = fRXPat->fInitialChars->charAt(0); |
| U_ASSERT(fRXPat->fInitialChar != (UChar32)-1); |
| } else if (fRXPat->fInitialChars->contains((UChar32)0, (UChar32)0x10ffff) == FALSE && |
| fRXPat->fMinMatchLen > 0) { |
| // Matches start with a set of character smaller than the set of all chars. |
| fRXPat->fStartType = START_SET; |
| } else { |
| // Matches can start with anything |
| fRXPat->fStartType = START_NO_INFO; |
| } |
| |
| return; |
| } |
| |
| |
| |
| //---------------------------------------------------------------------------------------- |
| // |
| // minMatchLength Calculate the length of the shortest string that could |
| // match the specified pattern. |
| // Length is in 16 bit code units, not code points. |
| // |
| // The calculated length may not be exact. The returned |
| // value may be shorter than the actual minimum; it must |
| // never be longer. |
| // |
| // start and end are the range of p-code operations to be |
| // examined. The endpoints are included in the range. |
| // |
| //---------------------------------------------------------------------------------------- |
| int32_t RegexCompile::minMatchLength(int32_t start, int32_t end) { |
| if (U_FAILURE(*fStatus)) { |
| return 0; |
| } |
| |
| U_ASSERT(start <= end); |
| U_ASSERT(end < fRXPat->fCompiledPat->size()); |
| |
| |
| int32_t loc; |
| int32_t op; |
| int32_t opType; |
| int32_t currentLen = 0; |
| |
| |
| // forwardedLength is a vector holding minimum-match-length values that |
| // are propagated forward in the pattern by JMP or STATE_SAVE operations. |
| // It must be one longer than the pattern being checked because some ops |
| // will jmp to a end-of-block+1 location from within a block, and we must |
| // count those when checking the block. |
| UVector32 forwardedLength(end+2, *fStatus); |
| forwardedLength.setSize(end+2); |
| for (loc=start; loc<=end+1; loc++) { |
| forwardedLength.setElementAt(INT32_MAX, loc); |
| } |
| |
| for (loc = start; loc<=end; loc++) { |
| op = fRXPat->fCompiledPat->elementAti(loc); |
| opType = URX_TYPE(op); |
| |
| // The loop is advancing linearly through the pattern. |
| // If the op we are now at was the destination of a branch in the pattern, |
| // and that path has a shorter minimum length than the current accumulated value, |
| // replace the current accumulated value. |
| U_ASSERT(currentLen>=0 && currentLen < INT32_MAX); |
| if (forwardedLength.elementAti(loc) < currentLen) { |
| currentLen = forwardedLength.elementAti(loc); |
| U_ASSERT(currentLen>=0 && currentLen < INT32_MAX); |
| } |
| |
| switch (opType) { |
| // Ops that don't change the total length matched |
| case URX_RESERVED_OP: |
| case URX_END: |
| case URX_STRING_LEN: |
| case URX_NOP: |
| case URX_START_CAPTURE: |
| case URX_END_CAPTURE: |
| case URX_BACKSLASH_B: |
| case URX_BACKSLASH_BU: |
| case URX_BACKSLASH_G: |
| case URX_BACKSLASH_Z: |
| case URX_CARET: |
| case URX_DOLLAR: |
| case URX_RELOC_OPRND: |
| case URX_STO_INP_LOC: |
| case URX_DOLLAR_M: |
| case URX_CARET_M: |
| case URX_BACKTRACK: |
| case URX_BACKREF: // BackRef. Must assume that it might be a zero length match |
| case URX_BACKREF_I: |
| |
| case URX_STO_SP: // Setup for atomic or possessive blocks. Doesn't change what can match. |
| case URX_LD_SP: |
| |
| case URX_JMP_SAV: |
| case URX_JMP_SAV_X: |
| break; |
| |
| |
| // Ops that match a minimum of one character (one or two 16 bit code units.) |
| // |
| case URX_ONECHAR: |
| case URX_STATIC_SETREF: |
| case URX_STAT_SETREF_N: |
| case URX_SETREF: |
| case URX_BACKSLASH_D: |
| case URX_ONECHAR_I: |
| case URX_BACKSLASH_X: // Grahpeme Cluster. Minimum is 1, max unbounded. |
| case URX_DOTANY_ALL: // . matches one or two. |
| case URX_DOTANY: |
| case URX_DOTANY_PL: |
| case URX_DOTANY_ALL_PL: |
| currentLen++; |
| break; |
| |
| |
| case URX_JMPX: |
| loc++; // URX_JMPX has an extra operand, ignored here, |
| // otherwise processed identically to URX_JMP. |
| case URX_JMP: |
| { |
| int32_t jmpDest = URX_VAL(op); |
| if (jmpDest < loc) { |
| // Loop of some kind. Can safely ignore, the worst that will happen |
| // is that we understate the true minimum length |
| currentLen = forwardedLength.elementAti(loc+1); |
| } else { |
| // Forward jump. Propagate the current min length to the target loc of the jump. |
| U_ASSERT(jmpDest <= end+1); |
| if (forwardedLength.elementAti(jmpDest) > currentLen) { |
| forwardedLength.setElementAt(currentLen, jmpDest); |
| } |
| } |
| } |
| break; |
| |
| case URX_FAIL: |
| { |
| // Fails are kind of like a branch, except that the min length was |
| // propagated already, by the state save. |
| currentLen = forwardedLength.elementAti(loc+1); |
| U_ASSERT(currentLen>=0 && currentLen < INT32_MAX); |
| } |
| break; |
| |
| |
| case URX_STATE_SAVE: |
| { |
| // State Save, for forward jumps, propagate the current minimum. |
| // of the state save. |
| int32_t jmpDest = URX_VAL(op); |
| if (jmpDest > loc) { |
| if (currentLen < forwardedLength.elementAti(jmpDest)) { |
| forwardedLength.setElementAt(currentLen, jmpDest); |
| } |
| } |
| } |
| break; |
| |
| |
| case URX_STRING: |
| case URX_STRING_I: |
| { |
| loc++; |
| int32_t stringLenOp = fRXPat->fCompiledPat->elementAti(loc); |
| currentLen += URX_VAL(stringLenOp); |
| } |
| break; |
| |
| |
| case URX_CTR_INIT: |
| case URX_CTR_INIT_NG: |
| { |
| // Loop Init Ops. |
| // If the min loop count == 0 |
| // move loc forwards to the end of the loop, skipping over the body. |
| // If the min count is > 0, |
| // continue normal processing of the body of the loop. |
| int32_t loopEndLoc = fRXPat->fCompiledPat->elementAti(loc+1); |
| loopEndLoc = URX_VAL(loopEndLoc); |
| int32_t minLoopCount = fRXPat->fCompiledPat->elementAti(loc+2); |
| if (minLoopCount == 0) { |
| loc = loopEndLoc; |
| } else { |
| loc+=3; // Skips over operands of CTR_INIT |
| } |
| } |
| break; |
| |
| |
| case URX_CTR_LOOP: |
| case URX_CTR_LOOP_NG: |
| // Loop ops. |
| // The jump is conditional, backwards only. |
| break; |
| |
| case URX_LOOP_SR_I: |
| case URX_LOOP_DOT_I: |
| case URX_LOOP_C: |
| // More loop ops. These state-save to themselves. |
| // don't change the minimum match - could match nothing at all. |
| break; |
| |
| |
| case URX_LA_START: |
| case URX_LB_START: |
| { |
| // Look-around. Scan forward until the matching look-ahead end, |
| // without processing the look-around block. This is overly pessimistic. |
| // TODO: Positive lookahead could recursively do the block, then continue |
| // with the longer of the block or the value coming in. |
| int32_t depth = 0; |
| for (;;) { |
| loc++; |
| op = fRXPat->fCompiledPat->elementAti(loc); |
| if (URX_TYPE(op) == URX_LA_START || URX_TYPE(op) == URX_LB_START) { |
| depth++; |
| } |
| if (URX_TYPE(op) == URX_LA_END || URX_TYPE(op)==URX_LBN_END) { |
| if (depth == 0) { |
| break; |
| } |
| depth--; |
| } |
| if (URX_TYPE(op) == URX_STATE_SAVE) { |
| // Need this because neg lookahead blocks will FAIL to outside |
| // of the block. |
| int32_t jmpDest = URX_VAL(op); |
| if (jmpDest > loc) { |
| if (currentLen < forwardedLength.elementAti(jmpDest)) { |
| forwardedLength.setElementAt(currentLen, jmpDest); |
| } |
| } |
| } |
| |
| U_ASSERT(loc <= end); |
| } |
| } |
| break; |
| |
| case URX_LA_END: |
| case URX_LB_CONT: |
| case URX_LB_END: |
| case URX_LBN_CONT: |
| case URX_LBN_END: |
| // Only come here if the matching URX_LA_START or URX_LB_START was not in the |
| // range being sized, which happens when measuring size of look-behind blocks. |
| break; |
| |
| default: |
| U_ASSERT(FALSE); |
| } |
| |
| } |
| |
| // We have finished walking through the ops. Check whether some forward jump |
| // propagated a shorter length to location end+1. |
| if (forwardedLength.elementAti(end+1) < currentLen) { |
| currentLen = forwardedLength.elementAti(end+1); |
| U_ASSERT(currentLen>=0 && currentLen < INT32_MAX); |
| } |
| |
| return currentLen; |
| } |
| |
| |
| |
| //---------------------------------------------------------------------------------------- |
| // |
| // maxMatchLength Calculate the length of the longest string that could |
| // match the specified pattern. |
| // Length is in 16 bit code units, not code points. |
| // |
| // The calculated length may not be exact. The returned |
| // value may be longer than the actual maximum; it must |
| // never be shorter. |
| // |
| //---------------------------------------------------------------------------------------- |
| int32_t RegexCompile::maxMatchLength(int32_t start, int32_t end) { |
| if (U_FAILURE(*fStatus)) { |
| return 0; |
| } |
| U_ASSERT(start <= end); |
| U_ASSERT(end < fRXPat->fCompiledPat->size()); |
| |
| |
| int32_t loc; |
| int32_t op; |
| int32_t opType; |
| int32_t currentLen = 0; |
| UVector32 forwardedLength(end+1, *fStatus); |
| forwardedLength.setSize(end+1); |
| |
| for (loc=start; loc<=end; loc++) { |
| forwardedLength.setElementAt(0, loc); |
| } |
| |
| for (loc = start; loc<=end; loc++) { |
| op = fRXPat->fCompiledPat->elementAti(loc); |
| opType = URX_TYPE(op); |
| |
| // The loop is advancing linearly through the pattern. |
| // If the op we are now at was the destination of a branch in the pattern, |
| // and that path has a longer maximum length than the current accumulated value, |
| // replace the current accumulated value. |
| if (forwardedLength.elementAti(loc) > currentLen) { |
| currentLen = forwardedLength.elementAti(loc); |
| } |
| |
| switch (opType) { |
| // Ops that don't change the total length matched |
| case URX_RESERVED_OP: |
| case URX_END: |
| case URX_STRING_LEN: |
| case URX_NOP: |
| case URX_START_CAPTURE: |
| case URX_END_CAPTURE: |
| case URX_BACKSLASH_B: |
| case URX_BACKSLASH_BU: |
| case URX_BACKSLASH_G: |
| case URX_BACKSLASH_Z: |
| case URX_CARET: |
| case URX_DOLLAR: |
| case URX_RELOC_OPRND: |
| case URX_STO_INP_LOC: |
| case URX_DOLLAR_M: |
| case URX_CARET_M: |
| case URX_BACKTRACK: |
| |
| case URX_STO_SP: // Setup for atomic or possessive blocks. Doesn't change what can match. |
| case URX_LD_SP: |
| |
| case URX_LB_END: |
| case URX_LB_CONT: |
| case URX_LBN_CONT: |
| case URX_LBN_END: |
| break; |
| |
| |
| // Ops that increase that cause an unbounded increase in the length |
| // of a matched string, or that increase it a hard to characterize way. |
| // Call the max length unbounded, and stop further checking. |
| case URX_BACKREF: // BackRef. Must assume that it might be a zero length match |
| case URX_BACKREF_I: |
| case URX_BACKSLASH_X: // Grahpeme Cluster. Minimum is 1, max unbounded. |
| case URX_DOTANY_PL: |
| case URX_DOTANY_ALL_PL: |
| currentLen = INT32_MAX; |
| break; |
| |
| |
| // Ops that match a max of one character (possibly two 16 bit code units.) |
| // |
| case URX_STATIC_SETREF: |
| case URX_STAT_SETREF_N: |
| case URX_SETREF: |
| case URX_BACKSLASH_D: |
| case URX_ONECHAR_I: |
| case URX_DOTANY_ALL: |
| case URX_DOTANY: |
| currentLen+=2; |
| break; |
| |
| // Single literal character. Increase current max length by one or two, |
| // depending on whether the char is in the supplementary range. |
| case URX_ONECHAR: |
| currentLen++; |
| if (URX_VAL(op) > 0x10000) { |
| currentLen++; |
| } |
| break; |
| |
| // Jumps. |
| // |
| case URX_JMP: |
| case URX_JMPX: |
| case URX_JMP_SAV: |
| case URX_JMP_SAV_X: |
| { |
| int32_t jmpDest = URX_VAL(op); |
| if (jmpDest < loc) { |
| // Loop of some kind. Max match length is unbounded. |
| currentLen = INT32_MAX; |
| } else { |
| // Forward jump. Propagate the current min length to the target loc of the jump. |
| if (forwardedLength.elementAti(jmpDest) < currentLen) { |
| forwardedLength.setElementAt(currentLen, jmpDest); |
| } |
| currentLen = 0; |
| } |
| } |
| break; |
| |
| case URX_FAIL: |
| // Fails are kind of like a branch, except that the max length was |
| // propagated already, by the state save. |
| currentLen = forwardedLength.elementAti(loc+1); |
| break; |
| |
| |
| case URX_STATE_SAVE: |
| { |
| // State Save, for forward jumps, propagate the current minimum. |
| // of the state save. |
| // For backwards jumps, they create a loop, maximum |
| // match length is unbounded. |
| int32_t jmpDest = URX_VAL(op); |
| if (jmpDest > loc) { |
| if (currentLen > forwardedLength.elementAti(jmpDest)) { |
| forwardedLength.setElementAt(currentLen, jmpDest); |
| } |
| } else { |
| currentLen = INT32_MAX; |
| } |
| } |
| break; |
| |
| |
| |
| |
| case URX_STRING: |
| case URX_STRING_I: |
| { |
| loc++; |
| int32_t stringLenOp = fRXPat->fCompiledPat->elementAti(loc); |
| currentLen += URX_VAL(stringLenOp); |
| } |
| break; |
| |
| |
| case URX_CTR_INIT: |
| case URX_CTR_INIT_NG: |
| case URX_CTR_LOOP: |
| case URX_CTR_LOOP_NG: |
| case URX_LOOP_SR_I: |
| case URX_LOOP_DOT_I: |
| case URX_LOOP_C: |
| // For anything to do with loops, make the match length unbounded. |
| // Note: INIT instructions are multi-word. Can ignore because |
| // INT32_MAX length will stop the per-instruction loop. |
| currentLen = INT32_MAX; |
| break; |
| |
| |
| |
| case URX_LA_START: |
| case URX_LA_END: |
| // Look-ahead. Just ignore, treat the look-ahead block as if |
| // it were normal pattern. Gives a too-long match length, |
| // but good enough for now. |
| break; |
| |
| // End of look-ahead ops should always be consumed by the processing at |
| // the URX_LA_START op. |
| U_ASSERT(FALSE); |
| break; |
| |
| case URX_LB_START: |
| { |
| // Look-behind. Scan forward until the matching look-around end, |
| // without processing the look-behind block. |
| int32_t depth = 0; |
| for (;;) { |
| loc++; |
| op = fRXPat->fCompiledPat->elementAti(loc); |
| if (URX_TYPE(op) == URX_LA_START || URX_TYPE(op) == URX_LB_START) { |
| depth++; |
| } |
| if (URX_TYPE(op) == URX_LA_END || URX_TYPE(op)==URX_LBN_END) { |
| if (depth == 0) { |
| break; |
| } |
| depth--; |
| } |
| U_ASSERT(loc < end); |
| } |
| } |
| break; |
| |
| default: |
| U_ASSERT(FALSE); |
| } |
| |
| |
| if (currentLen == INT32_MAX) { |
| // The maximum length is unbounded. |
| // Stop further processing of the pattern. |
| break; |
| } |
| |
| } |
| return currentLen; |
| |
| } |
| |
| |
| //---------------------------------------------------------------------------------------- |
| // |
| // stripNOPs Remove any NOP operations from the compiled pattern code. |
| // Extra NOPs are inserted for some constructs during the initial |
| // code generation to provide locations that may be patched later. |
| // Many end up unneeded, and are removed by this function. |
| // |
| //---------------------------------------------------------------------------------------- |
| void RegexCompile::stripNOPs() { |
| |
| if (U_FAILURE(*fStatus)) { |
| return; |
| } |
| |
| int32_t end = fRXPat->fCompiledPat->size(); |
| UVector32 deltas(end, *fStatus); |
| |
| // Make a first pass over the code, computing the amount that things |
| // will be offset at each location in the original code. |
| int32_t loc; |
| int32_t d = 0; |
| for (loc=0; loc<end; loc++) { |
| deltas.addElement(d, *fStatus); |
| int32_t op = fRXPat->fCompiledPat->elementAti(loc); |
| if (URX_TYPE(op) == URX_NOP) { |
| d++; |
| } |
| } |
| |
| // Make a second pass over the code, removing the NOPs by moving following |
| // code up, and patching operands that refer to code locations that |
| // are being moved. The array of offsets from the first step is used |
| // to compute the new operand values. |
| int32_t src; |
| int32_t dst = 0; |
| for (src=0; src<end; src++) { |
| int32_t op = fRXPat->fCompiledPat->elementAti(src); |
| int32_t opType = URX_TYPE(op); |
| switch (opType) { |
| case URX_NOP: |
| break; |
| |
| case URX_STATE_SAVE: |
| case URX_JMP: |
| case URX_CTR_LOOP: |
| case URX_CTR_LOOP_NG: |
| case URX_RELOC_OPRND: |
| case URX_JMPX: |
| case URX_JMP_SAV: |
| case URX_JMP_SAV_X: |
| // These are instructions with operands that refer to code locations. |
| { |
| int32_t operandAddress = URX_VAL(op); |
| U_ASSERT(operandAddress>=0 && operandAddress<deltas.size()); |
| int32_t fixedOperandAddress = operandAddress - deltas.elementAti(operandAddress); |
| op = URX_BUILD(opType, fixedOperandAddress); |
| fRXPat->fCompiledPat->setElementAt(op, dst); |
| dst++; |
| break; |
| } |
| |
| case URX_RESERVED_OP: |
| case URX_RESERVED_OP_N: |
| case URX_BACKTRACK: |
| case URX_END: |
| case URX_ONECHAR: |
| case URX_STRING: |
| case URX_STRING_LEN: |
| case URX_START_CAPTURE: |
| case URX_END_CAPTURE: |
| case URX_STATIC_SETREF: |
| case URX_STAT_SETREF_N: |
| case URX_SETREF: |
| case URX_DOTANY: |
| case URX_FAIL: |
| case URX_BACKSLASH_B: |
| case URX_BACKSLASH_BU: |
| case URX_BACKSLASH_G: |
| case URX_BACKSLASH_X: |
| case URX_BACKSLASH_Z: |
| case URX_DOTANY_ALL: |
| case URX_DOTANY_ALL_PL: |
| case URX_DOTANY_PL: |
| case URX_BACKSLASH_D: |
| case URX_CARET: |
| case URX_DOLLAR: |
| case URX_CTR_INIT: |
| case URX_CTR_INIT_NG: |
| case URX_STO_SP: |
| case URX_LD_SP: |
| case URX_BACKREF: |
| case URX_STO_INP_LOC: |
| case URX_LA_START: |
| case URX_LA_END: |
| case URX_ONECHAR_I: |
| case URX_STRING_I: |
| case URX_BACKREF_I: |
| case URX_DOLLAR_M: |
| case URX_CARET_M: |
| case URX_LB_START: |
| case URX_LB_CONT: |
| case URX_LB_END: |
| case URX_LBN_CONT: |
| case URX_LBN_END: |
| case URX_LOOP_SR_I: |
| case URX_LOOP_DOT_I: |
| case URX_LOOP_C: |
| // These instructions are unaltered by the relocation. |
| fRXPat->fCompiledPat->setElementAt(op, dst); |
| dst++; |
| break; |
| |
| default: |
| // Some op is unaccounted for. |
| U_ASSERT(FALSE); |
| error(U_REGEX_INTERNAL_ERROR); |
| } |
| } |
| |
| fRXPat->fCompiledPat->setSize(dst); |
| } |
| |
| |
| |
| |
| //---------------------------------------------------------------------------------------- |
| // |
| // OptDotStar Optimize patterns that end with a '.*' or '.+' to |
| // just advance the input to the end. |
| // |
| // Transform this compiled sequence |
| // [DOT_ANY | DOT_ANY_ALL] |
| // JMP_SAV to previous instruction |
| // [NOP | END_CAPTURE | DOLLAR | BACKSLASH_Z]* |
| // END |
| // |
| // To |
| // NOP |
| // [DOT_ANY_PL | DOT_ANY_ALL_PL] |
| // [NOP | END_CAPTURE | DOLLAR | BACKSLASH_Z]* |
| // END |
| // |
| //---------------------------------------------------------------------------------------- |
| void RegexCompile::OptDotStar() { |
| // Scan backwards in the pattern, looking for a JMP_SAV near the end. |
| int32_t jmpLoc; |
| int32_t op = 0; |
| int32_t opType; |
| for (jmpLoc=fRXPat->fCompiledPat->size(); jmpLoc--;) { |
| U_ASSERT(jmpLoc>0); |
| op = fRXPat->fCompiledPat->elementAti(jmpLoc); |
| opType = URX_TYPE(op); |
| switch(opType) { |
| |
| |
| case URX_END: |
| case URX_NOP: |
| case URX_END_CAPTURE: |
| case URX_DOLLAR_M: |
| case URX_DOLLAR: |
| case URX_BACKSLASH_Z: |
| // These ops may follow the JMP_SAV without preventing us from |
| // doing this optimization. |
| continue; |
| |
| case URX_JMP_SAV: |
| // Got a trailing JMP_SAV that's a candidate for optimization. |
| break; |
| |
| default: |
| // This optimization not possible. |
| return; |
| } |
| break; // from the for loop. |
| } |
| |
| // We found in URX_JMP_SAV near the end that is a candidate for optimizing. |
| // Is the target address the previous instruction? |
| // Is the previous instruction a flavor of URX_DOTANY |
| int32_t loopTopLoc = URX_VAL(op); |
| if (loopTopLoc != jmpLoc-1) { |
| return; |
| } |
| int32_t newOp; |
| int32_t oldOp = fRXPat->fCompiledPat->elementAti(loopTopLoc); |
| int32_t oldOpType = opType = URX_TYPE(oldOp); |
| if (oldOpType == URX_DOTANY) { |
| newOp = URX_BUILD(URX_DOTANY_PL, 0); |
| } |
| else if (oldOpType == URX_DOTANY_ALL) { |
| newOp = URX_BUILD(URX_DOTANY_ALL_PL, 0); |
| } else { |
| return; // Sequence we were looking for isn't there. |
| } |
| |
| // Substitute the new instructions into the pattern. |
| // The NOP will be removed in a later optimization step. |
| fRXPat->fCompiledPat->setElementAt(URX_BUILD(URX_NOP, 0), loopTopLoc); |
| fRXPat->fCompiledPat->setElementAt(newOp, jmpLoc); |
| } |
| |
| |
| //---------------------------------------------------------------------------------------- |
| // |
| // Error Report a rule parse error. |
| // Only report it if no previous error has been recorded. |
| // |
| //---------------------------------------------------------------------------------------- |
| void RegexCompile::error(UErrorCode e) { |
| if (U_SUCCESS(*fStatus)) { |
| *fStatus = e; |
| fParseErr->line = fLineNum; |
| fParseErr->offset = fCharNum; |
| |
| // Fill in the context. |
| // Note: extractBetween() pins supplied indicies to the string bounds. |
| uprv_memset(fParseErr->preContext, 0, sizeof(fParseErr->preContext)); |
| uprv_memset(fParseErr->postContext, 0, sizeof(fParseErr->postContext)); |
| fRXPat->fPattern.extractBetween(fScanIndex-U_PARSE_CONTEXT_LEN+1, fScanIndex, |
| fParseErr->preContext, 0); |
| fRXPat->fPattern.extractBetween(fScanIndex, fScanIndex+U_PARSE_CONTEXT_LEN-1, |
| fParseErr->postContext, 0); |
| } |
| } |
| |
| |
| // |
| // Assorted Unicode character constants. |
| // Numeric because there is no portable way to enter them as literals. |
| // (Think EBCDIC). |
| // |
| static const UChar chCR = 0x0d; // New lines, for terminating comments. |
| static const UChar chLF = 0x0a; |
| static const UChar chNEL = 0x85; // NEL newline variant |
| static const UChar chLS = 0x2028; // Unicode Line Separator |
| static const UChar chApos = 0x27; // single quote, for quoted chars. |
| static const UChar chPound = 0x23; // '#', introduces a comment. |
| static const UChar chE = 0x45; // 'E' |
| static const UChar chBackSlash = 0x5c; // '\' introduces a char escape |
| static const UChar chLParen = 0x28; |
| static const UChar chRParen = 0x29; |
| static const UChar chLBracket = 0x5b; |
| static const UChar chRBracket = 0x5d; |
| static const UChar chRBrace = 0x7d; |
| static const UChar chUpperN = 0x4E; |
| static const UChar chLowerP = 0x70; |
| static const UChar chUpperP = 0x50; |
| |
| |
| //---------------------------------------------------------------------------------------- |
| // |
| // nextCharLL Low Level Next Char from the regex pattern. |
| // Get a char from the string, keep track of input position |
| // for error reporting. |
| // |
| //---------------------------------------------------------------------------------------- |
| UChar32 RegexCompile::nextCharLL() { |
| UChar32 ch; |
| UnicodeString &pattern = fRXPat->fPattern; |
| |
| if (fPeekChar != -1) { |
| ch = fPeekChar; |
| fPeekChar = -1; |
| return ch; |
| } |
| if (fPatternLength==0 || fNextIndex >= fPatternLength) { |
| return (UChar32)-1; |
| } |
| ch = pattern.char32At(fNextIndex); |
| fNextIndex = pattern.moveIndex32(fNextIndex, 1); |
| |
| if (ch == chCR || |
| ch == chNEL || |
| ch == chLS || |
| ch == chLF && fLastChar != chCR) { |
| // Character is starting a new line. Bump up the line number, and |
| // reset the column to 0. |
| fLineNum++; |
| fCharNum=0; |
| if (fQuoteMode) { |
| error(U_REGEX_RULE_SYNTAX); |
| fQuoteMode = FALSE; |
| } |
| } |
| else { |
| // Character is not starting a new line. Except in the case of a |
| // LF following a CR, increment the column position. |
| if (ch != chLF) { |
| fCharNum++; |
| } |
| } |
| fLastChar = ch; |
| return ch; |
| } |
| |
| //--------------------------------------------------------------------------------- |
| // |
| // peekCharLL Low Level Character Scanning, sneak a peek at the next |
| // character without actually getting it. |
| // |
| //--------------------------------------------------------------------------------- |
| UChar32 RegexCompile::peekCharLL() { |
| if (fPeekChar == -1) { |
| fPeekChar = nextCharLL(); |
| } |
| return fPeekChar; |
| } |
| |
| |
| //--------------------------------------------------------------------------------- |
| // |
| // nextChar for pattern scanning. At this level, we handle stripping |
| // out comments and processing some backslash character escapes. |
| // The rest of the pattern grammar is handled at the next level up. |
| // |
| //--------------------------------------------------------------------------------- |
| void RegexCompile::nextChar(RegexPatternChar &c) { |
| |
| fScanIndex = fNextIndex; |
| c.fChar = nextCharLL(); |
| c.fQuoted = FALSE; |
| |
| if (fQuoteMode) { |
| c.fQuoted = TRUE; |
| if ((c.fChar==chBackSlash && peekCharLL()==chE) || c.fChar == (UChar32)-1) { |
| fQuoteMode = FALSE; // Exit quote mode, |
| nextCharLL(); // discard the E |
| nextChar(c); // recurse to get the real next char |
| } |
| } |
| else if (fInBackslashQuote) { |
| // The current character immediately follows a '\' |
| // Don't check for any further escapes, just return it as-is. |
| // Don't set c.fQuoted, because that would prevent the state machine from |
| // dispatching on the character. |
| fInBackslashQuote = FALSE; |
| } |
| else |
| { |
| // We are not in a \Q quoted region \E of the source. |
| // |
| if (fModeFlags & UREGEX_COMMENTS) { |
| // |
| // We are in free-spacing and comments mode. |
| // Scan through any white space and comments, until we |
| // reach a significant character or the end of inut. |
| for (;;) { |
| if (c.fChar == (UChar32)-1) { |
| break; // End of Input |
| } |
| if (c.fChar == chPound && fEOLComments == TRUE) { |
| // Start of a comment. Consume the rest of it, until EOF or a new line |
| for (;;) { |
| c.fChar = nextCharLL(); |
| if (c.fChar == (UChar32)-1 || // EOF |
| c.fChar == chCR || |
| c.fChar == chLF || |
| c.fChar == chNEL || |
| c.fChar == chLS) { |
| break; |
| } |
| } |
| } |
| if (uprv_isRuleWhiteSpace(c.fChar) == FALSE) { |
| break; |
| } |
| c.fChar = nextCharLL(); |
| } |
| } |
| |
| // |
| // check for backslash escaped characters. |
| // |
| int32_t startX = fNextIndex; // start and end positions of the |
| int32_t endX = fNextIndex; // sequence following the '\' |
| if (c.fChar == chBackSlash) { |
| if (RegexStaticSets::gStaticSets->fUnescapeCharSet->contains(peekCharLL())) { |
| // |
| // A '\' sequence that is handled by ICU's standard unescapeAt function. |
| // Includes \uxxxx, \n, \r, many others. |
| // Return the single equivalent character. |
| // |
| nextCharLL(); // get & discard the peeked char. |
| c.fQuoted = TRUE; |
| c.fChar = fRXPat->fPattern.unescapeAt(endX); |
| if (startX == endX) { |
| error(U_REGEX_BAD_ESCAPE_SEQUENCE); |
| } |
| fCharNum += endX - startX; |
| fNextIndex = endX; |
| } |
| else |
| { |
| // We are in a '\' escape that will be handled by the state table scanner. |
| // Just return the backslash, but remember that the following char is to |
| // be taken literally. TODO: this is awkward, think about alternatives. |
| fInBackslashQuote = TRUE; |
| } |
| } |
| } |
| |
| // re-enable # to end-of-line comments, in case they were disabled. |
| // They are disabled by the parser upon seeing '(?', but this lasts for |
| // the fetching of the next character only. |
| fEOLComments = TRUE; |
| |
| // putc(c.fChar, stdout); |
| } |
| |
| |
| |
| //--------------------------------------------------------------------------------- |
| // |
| // scanSet Construct a UnicodeSet from the text at the current scan |
| // position. Advance the scan position to the first character |
| // after the set. |
| // |
| // The scan position is normally under the control of the state machine |
| // that controls pattern parsing. UnicodeSets, however, are parsed by |
| // the UnicodeSet constructor, not by the Regex pattern parser. |
| // |
| //--------------------------------------------------------------------------------- |
| UnicodeSet *RegexCompile::scanSet() { |
| UnicodeSet *uset = NULL; |
| ParsePosition pos; |
| int startPos; |
| int i; |
| |
| if (U_FAILURE(*fStatus)) { |
| return NULL; |
| } |
| |
| pos.setIndex(fScanIndex); |
| startPos = fScanIndex; |
| UErrorCode localStatus = U_ZERO_ERROR; |
| uint32_t usetFlags = 0; |
| if (fModeFlags & UREGEX_CASE_INSENSITIVE) { |
| usetFlags |= USET_CASE_INSENSITIVE; |
| } |
| if (fModeFlags & UREGEX_COMMENTS) { |
| usetFlags |= USET_IGNORE_SPACE; |
| } |
| |
| uset = new UnicodeSet(fRXPat->fPattern, pos, |
| usetFlags, NULL, localStatus); |
| if (U_FAILURE(localStatus)) { |
| // TODO: Get more accurate position of the error from UnicodeSet's return info. |
| // UnicodeSet appears to not be reporting correctly at this time. |
| REGEX_SCAN_DEBUG_PRINTF( "UnicodeSet parse postion.ErrorIndex = %d\n", pos.getIndex()); |
| error(localStatus); |
| delete uset; |
| return NULL; |
| } |
| |
| // Advance the current scan postion over the UnicodeSet. |
| // Don't just set fScanIndex because the line/char positions maintained |
| // for error reporting would be thrown off. |
| i = pos.getIndex(); |
| for (;;) { |
| if (fNextIndex >= i) { |
| break; |
| } |
| nextCharLL(); |
| } |
| |
| return uset; |
| }; |
| |
| |
| //--------------------------------------------------------------------------------- |
| // |
| // scanProp Construct a UnicodeSet from the text at the current scan |
| // position, which will be of the form \p{whaterver} |
| // |
| // The scan position will be at the 'p' or 'P'. On return |
| // the scan position should be just after the '}' |
| // |
| // Return a UnicodeSet, constructed from the \P pattern, |
| // or NULL if the pattern is invalid. |
| // |
| //--------------------------------------------------------------------------------- |
| UnicodeSet *RegexCompile::scanProp() { |
| UnicodeSet *uset = NULL; |
| |
| if (U_FAILURE(*fStatus)) { |
| return NULL; |
| } |
| |
| U_ASSERT(fC.fChar == chLowerP || fC.fChar == chUpperP || fC.fChar == chUpperN); |
| |
| // enclose the \p{property} from the regex pattern source in [brackets] |
| UnicodeString setPattern; |
| setPattern.append(chLBracket); |
| setPattern.append(chBackSlash); |
| for (;;) { |
| setPattern.append(fC.fChar); |
| if (fC.fChar == chRBrace) { |
| break; |
| } |
| nextChar(fC); |
| if (fC.fChar == -1) { |
| // Hit the end of the input string without finding the closing '}' |
| error(U_REGEX_PROPERTY_SYNTAX); |
| return NULL; |
| } |
| } |
| setPattern.append(chRBracket); |
| |
| uint32_t usetFlags = 0; |
| if (fModeFlags & UREGEX_CASE_INSENSITIVE) { |
| usetFlags |= USET_CASE_INSENSITIVE; |
| } |
| if (fModeFlags & UREGEX_COMMENTS) { |
| usetFlags |= USET_IGNORE_SPACE; |
| } |
| |
| // Build the UnicodeSet from the set pattern we just built up in a string. |
| uset = new UnicodeSet(setPattern, usetFlags, NULL, *fStatus); |
| if (U_FAILURE(*fStatus)) { |
| delete uset; |
| uset = NULL; |
| } |
| |
| nextChar(fC); // Continue overall regex pattern processing with char after the '}' |
| return uset; |
| }; |
| |
| U_NAMESPACE_END |
| #endif // !UCONFIG_NO_REGULAR_EXPRESSIONS |