The Tor Browser: intl/icu/source/common/rbbiscan.cpp@129ffea94266 (annotated)

intl/icu/source/common/rbbiscan.cpp@129ffea94266 (annotated)

intl/icu/source/common/rbbiscan.cpp

Sat, 03 Jan 2015 20:18:00 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Sat, 03 Jan 2015 20:18:00 +0100
branch: TOR_BUG_3246
changeset 7: 129ffea94266
permissions: -rw-r--r--

Conditionally enable double key logic according to:
private browsing mode or privacy.thirdparty.isolate preference and
implement in GetCookieStringCommon and FindCookie where it counts...
With some reservations of how to convince FindCookie users to test
condition and pass a nullptr when disabling double key logic.

 //
 //  file:  rbbiscan.cpp
 //
 //  Copyright (C) 2002-2012, International Business Machines Corporation and others.
 //  All Rights Reserved.
 //
 //  This file contains the Rule Based Break Iterator Rule Builder functions for
 //   scanning the rules and assembling a parse tree.  This is the first phase
 //   of compiling the rules.
 //
 //  The overall of the rules is managed by class RBBIRuleBuilder, which will
 //  create and use an instance of this class as part of the process.
 //
 #include "unicode/utypes.h"
 #if !UCONFIG_NO_BREAK_ITERATION
 #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 "cmemory.h"
 #include "cstring.h"
 #include "rbbirpt.h"   // Contains state table for the rbbi rules parser.
                        //   generated by a Perl script.
 #include "rbbirb.h"
 #include "rbbinode.h"
 #include "rbbiscan.h"
 #include "rbbitblb.h"
 #include "uassert.h"
 #define LENGTHOF(array) (int32_t)(sizeof(array)/sizeof((array)[0]))
 //------------------------------------------------------------------------------
 //
 // Unicode Set init strings for each of the character classes needed for parsing a rule file.
 //               (Initialized with hex values for portability to EBCDIC based machines.
 //                Really ugly, but there's no good way to avoid it.)
 //
 //              The sets are referred to by name in the rbbirpt.txt, which is the
 //              source form of the state transition table for the RBBI rule parser.
 //
 //------------------------------------------------------------------------------
 static const UChar gRuleSet_rule_char_pattern[]       = {
  //   [    ^      [    \     p     {      Z     }     \     u    0      0    2      0
 x5b, 0x5e, 0x5b, 0x5c, 0x70, 0x7b, 0x5a, 0x7d, 0x5c, 0x75, 0x30, 0x30, 0x32, 0x30,
  //   -    \      u    0     0     7      f     ]     -     [    \      p
 x2d, 0x5c, 0x75, 0x30, 0x30, 0x37, 0x66, 0x5d, 0x2d, 0x5b, 0x5c, 0x70,
  //   {     L     }    ]     -     [      \     p     {     N    }      ]     ]
 x7b, 0x4c, 0x7d, 0x5d, 0x2d, 0x5b, 0x5c, 0x70, 0x7b, 0x4e, 0x7d, 0x5d, 0x5d, 0};
 static const UChar gRuleSet_name_char_pattern[]       = {
 //    [    _      \    p     {     L      }     \     p     {    N      }     ]
 x5b, 0x5f, 0x5c, 0x70, 0x7b, 0x4c, 0x7d, 0x5c, 0x70, 0x7b, 0x4e, 0x7d, 0x5d, 0};
 static const UChar gRuleSet_digit_char_pattern[] = {
 //    [    0      -    9     ]
 x5b, 0x30, 0x2d, 0x39, 0x5d, 0};
 static const UChar gRuleSet_name_start_char_pattern[] = {
 //    [    _      \    p     {     L      }     ]
 x5b, 0x5f, 0x5c, 0x70, 0x7b, 0x4c, 0x7d, 0x5d, 0 };
 static const UChar kAny[] = {0x61, 0x6e, 0x79, 0x00};  // "any"
 U_CDECL_BEGIN
 static void U_CALLCONV RBBISetTable_deleter(void *p) {
     icu::RBBISetTableEl *px = (icu::RBBISetTableEl *)p;
     delete px->key;
     // Note:  px->val is owned by the linked list "fSetsListHead" in scanner.
     //        Don't delete the value nodes here.
     uprv_free(px);
 }
 U_CDECL_END
 U_NAMESPACE_BEGIN
 //------------------------------------------------------------------------------
 //
 //  Constructor.
 //
 //------------------------------------------------------------------------------
 RBBIRuleScanner::RBBIRuleScanner(RBBIRuleBuilder *rb)
 {
     fRB                 = rb;
     fStackPtr           = 0;
     fStack[fStackPtr]   = 0;
     fNodeStackPtr       = 0;
     fRuleNum            = 0;
     fNodeStack[0]       = NULL;
     fSymbolTable                            = NULL;
     fSetTable                               = NULL;
     fScanIndex = 0;
     fNextIndex = 0;
     fReverseRule        = FALSE;
     fLookAheadRule      = FALSE;
     fLineNum    = 1;
     fCharNum    = 0;
     fQuoteMode  = FALSE;
     // Do not check status until after all critical fields are sufficiently initialized
     //   that the destructor can run cleanly.
     if (U_FAILURE(*rb->fStatus)) {
         return;
     }
     //
     //  Set up the constant Unicode Sets.
     //     Note:  These could be made static, lazily initialized, and shared among
     //            all instances of RBBIRuleScanners.  BUT this is quite a bit simpler,
     //            and the time to build these few sets should be small compared to a
     //            full break iterator build.
     fRuleSets[kRuleSet_rule_char-128]
         = UnicodeSet(UnicodeString(gRuleSet_rule_char_pattern),       *rb->fStatus);
     // fRuleSets[kRuleSet_white_space-128] = [:Pattern_White_Space:]
     fRuleSets[kRuleSet_white_space-128].
         add(9, 0xd).add(0x20).add(0x85).add(0x200e, 0x200f).add(0x2028, 0x2029);
     fRuleSets[kRuleSet_name_char-128]
         = UnicodeSet(UnicodeString(gRuleSet_name_char_pattern),       *rb->fStatus);
     fRuleSets[kRuleSet_name_start_char-128]
         = UnicodeSet(UnicodeString(gRuleSet_name_start_char_pattern), *rb->fStatus);
     fRuleSets[kRuleSet_digit_char-128]
         = UnicodeSet(UnicodeString(gRuleSet_digit_char_pattern),      *rb->fStatus);
     if (*rb->fStatus == U_ILLEGAL_ARGUMENT_ERROR) {
         // This case happens if ICU's data is missing.  UnicodeSet tries to look up property
         //   names from the init string, can't find them, and claims an illegal argument.
         //   Change the error so that the actual problem will be clearer to users.
         *rb->fStatus = U_BRK_INIT_ERROR;
     }
     if (U_FAILURE(*rb->fStatus)) {
         return;
     }
     fSymbolTable = new RBBISymbolTable(this, rb->fRules, *rb->fStatus);
     if (fSymbolTable == NULL) {
         *rb->fStatus = U_MEMORY_ALLOCATION_ERROR;
         return;
     }
     fSetTable    = uhash_open(uhash_hashUnicodeString, uhash_compareUnicodeString, NULL, rb->fStatus);
     if (U_FAILURE(*rb->fStatus)) {
         return;
     }
     uhash_setValueDeleter(fSetTable, RBBISetTable_deleter);
 }
 //------------------------------------------------------------------------------
 //
 //  Destructor
 //
 //------------------------------------------------------------------------------
 RBBIRuleScanner::~RBBIRuleScanner() {
     delete fSymbolTable;
     if (fSetTable != NULL) {
          uhash_close(fSetTable);
          fSetTable = NULL;
     }
     // Node Stack.
     //   Normally has one entry, which is the entire parse tree for the rules.
     //   If errors occured, there may be additional subtrees left on the stack.
     while (fNodeStackPtr > 0) {
         delete fNodeStack[fNodeStackPtr];
         fNodeStackPtr--;
     }
 }
 //------------------------------------------------------------------------------
 //
 //  doParseAction        Do some action during rule parsing.
 //                       Called by the parse state machine.
 //                       Actions build the parse tree and Unicode Sets,
 //                       and maintain the parse stack for nested expressions.
 //
 //                       TODO:  unify EParseAction and RBBI_RuleParseAction enum types.
 //                              They represent exactly the same thing.  They're separate
 //                              only to work around enum forward declaration restrictions
 //                              in some compilers, while at the same time avoiding multiple
 //                              definitions problems.  I'm sure that there's a better way.
 //
 //------------------------------------------------------------------------------
 UBool RBBIRuleScanner::doParseActions(int32_t action)
 {
     RBBINode *n       = NULL;
     UBool   returnVal = TRUE;
     switch (action) {
     case doExprStart:
         pushNewNode(RBBINode::opStart);
         fRuleNum++;
         break;
     case doExprOrOperator:
         {
             fixOpStack(RBBINode::precOpCat);
             RBBINode  *operandNode = fNodeStack[fNodeStackPtr--];
             RBBINode  *orNode      = pushNewNode(RBBINode::opOr);
             orNode->fLeftChild     = operandNode;
             operandNode->fParent   = orNode;
         }
         break;
     case doExprCatOperator:
         // concatenation operator.
         // For the implicit concatenation of adjacent terms in an expression that are
         //   not separated by any other operator.  Action is invoked between the
         //   actions for the two terms.
         {
             fixOpStack(RBBINode::precOpCat);
             RBBINode  *operandNode = fNodeStack[fNodeStackPtr--];
             RBBINode  *catNode     = pushNewNode(RBBINode::opCat);
             catNode->fLeftChild    = operandNode;
             operandNode->fParent   = catNode;
         }
         break;
     case doLParen:
         // Open Paren.
         //   The openParen node is a dummy operation type with a low precedence,
         //     which has the affect of ensuring that any real binary op that
         //     follows within the parens binds more tightly to the operands than
         //     stuff outside of the parens.
         pushNewNode(RBBINode::opLParen);
         break;
     case doExprRParen:
         fixOpStack(RBBINode::precLParen);
         break;
     case doNOP:
         break;
     case doStartAssign:
         // We've just scanned "$variable = "
         // The top of the node stack has the $variable ref node.
         // Save the start position of the RHS text in the StartExpression node
         //   that precedes the $variableReference node on the stack.
         //   This will eventually be used when saving the full $variable replacement
         //   text as a string.
         n = fNodeStack[fNodeStackPtr-1];
         n->fFirstPos = fNextIndex;              // move past the '='
         // Push a new start-of-expression node; needed to keep parse of the
         //   RHS expression happy.
         pushNewNode(RBBINode::opStart);
         break;
     case doEndAssign:
         {
             // We have reached the end of an assignement statement.
             //   Current scan char is the ';' that terminates the assignment.
             // Terminate expression, leaves expression parse tree rooted in TOS node.
             fixOpStack(RBBINode::precStart);
             RBBINode *startExprNode  = fNodeStack[fNodeStackPtr-2];
             RBBINode *varRefNode     = fNodeStack[fNodeStackPtr-1];
             RBBINode *RHSExprNode    = fNodeStack[fNodeStackPtr];
             // Save original text of right side of assignment, excluding the terminating ';'
             //  in the root of the node for the right-hand-side expression.
             RHSExprNode->fFirstPos = startExprNode->fFirstPos;
             RHSExprNode->fLastPos  = fScanIndex;
             fRB->fRules.extractBetween(RHSExprNode->fFirstPos, RHSExprNode->fLastPos, RHSExprNode->fText);
             // Expression parse tree becomes l. child of the $variable reference node.
             varRefNode->fLeftChild = RHSExprNode;
             RHSExprNode->fParent   = varRefNode;
             // Make a symbol table entry for the $variableRef node.
             fSymbolTable->addEntry(varRefNode->fText, varRefNode, *fRB->fStatus);
             if (U_FAILURE(*fRB->fStatus)) {
                 // This is a round-about way to get the parse position set
                 //  so that duplicate symbols error messages include a line number.
                 UErrorCode t = *fRB->fStatus;
                 *fRB->fStatus = U_ZERO_ERROR;
                 error(t);
             }
             // Clean up the stack.
             delete startExprNode;
             fNodeStackPtr-=3;
             break;
         }
     case doEndOfRule:
         {
         fixOpStack(RBBINode::precStart);      // Terminate expression, leaves expression
         if (U_FAILURE(*fRB->fStatus)) {       //   parse tree rooted in TOS node.
             break;
         }
 #ifdef RBBI_DEBUG
         if (fRB->fDebugEnv && uprv_strstr(fRB->fDebugEnv, "rtree")) {printNodeStack("end of rule");}
 #endif
         U_ASSERT(fNodeStackPtr == 1);
         // If this rule includes a look-ahead '/', add a endMark node to the
         //   expression tree.
         if (fLookAheadRule) {
             RBBINode  *thisRule       = fNodeStack[fNodeStackPtr];
             RBBINode  *endNode        = pushNewNode(RBBINode::endMark);
             RBBINode  *catNode        = pushNewNode(RBBINode::opCat);
             fNodeStackPtr -= 2;
             catNode->fLeftChild       = thisRule;
             catNode->fRightChild      = endNode;
             fNodeStack[fNodeStackPtr] = catNode;
             endNode->fVal             = fRuleNum;
             endNode->fLookAheadEnd    = TRUE;
         }
         // All rule expressions are ORed together.
         // The ';' that terminates an expression really just functions as a '|' with
         //   a low operator prededence.
         //
         // Each of the four sets of rules are collected separately.
         //  (forward, reverse, safe_forward, safe_reverse)
         //  OR this rule into the appropriate group of them.
         //
         RBBINode **destRules = (fReverseRule? &fRB->fReverseTree : fRB->fDefaultTree);
         if (*destRules != NULL) {
             // This is not the first rule encounted.
             // OR previous stuff  (from *destRules)
             // with the current rule expression (on the Node Stack)
             //  with the resulting OR expression going to *destRules
             //
             RBBINode  *thisRule    = fNodeStack[fNodeStackPtr];
             RBBINode  *prevRules   = *destRules;
             RBBINode  *orNode      = pushNewNode(RBBINode::opOr);
             orNode->fLeftChild     = prevRules;
             prevRules->fParent     = orNode;
             orNode->fRightChild    = thisRule;
             thisRule->fParent      = orNode;
             *destRules             = orNode;
         }
         else
         {
             // This is the first rule encountered (for this direction).
             // Just move its parse tree from the stack to *destRules.
             *destRules = fNodeStack[fNodeStackPtr];
         }
         fReverseRule   = FALSE;   // in preparation for the next rule.
         fLookAheadRule = FALSE;
         fNodeStackPtr  = 0;
         }
         break;
     case doRuleError:
         error(U_BRK_RULE_SYNTAX);
         returnVal = FALSE;
         break;
     case doVariableNameExpectedErr:
         error(U_BRK_RULE_SYNTAX);
         break;
     //
     //  Unary operands  + ? *
     //    These all appear after the operand to which they apply.
     //    When we hit one, the operand (may be a whole sub expression)
     //    will be on the top of the stack.
     //    Unary Operator becomes TOS, with the old TOS as its one child.
     case doUnaryOpPlus:
         {
             RBBINode  *operandNode = fNodeStack[fNodeStackPtr--];
             RBBINode  *plusNode    = pushNewNode(RBBINode::opPlus);
             plusNode->fLeftChild   = operandNode;
             operandNode->fParent   = plusNode;
         }
         break;
     case doUnaryOpQuestion:
         {
             RBBINode  *operandNode = fNodeStack[fNodeStackPtr--];
             RBBINode  *qNode       = pushNewNode(RBBINode::opQuestion);
             qNode->fLeftChild      = operandNode;
             operandNode->fParent   = qNode;
         }
         break;
     case doUnaryOpStar:
         {
             RBBINode  *operandNode = fNodeStack[fNodeStackPtr--];
             RBBINode  *starNode    = pushNewNode(RBBINode::opStar);
             starNode->fLeftChild   = operandNode;
             operandNode->fParent   = starNode;
         }
         break;
     case doRuleChar:
         // A "Rule Character" is any single character that is a literal part
         // of the regular expression.  Like a, b and c in the expression "(abc*) | [:L:]"
         // These are pretty uncommon in break rules; the terms are more commonly
         //  sets.  To keep things uniform, treat these characters like as
         // sets that just happen to contain only one character.
         {
             n = pushNewNode(RBBINode::setRef);
             findSetFor(UnicodeString(fC.fChar), n);
             n->fFirstPos = fScanIndex;
             n->fLastPos  = fNextIndex;
             fRB->fRules.extractBetween(n->fFirstPos, n->fLastPos, n->fText);
             break;
         }
     case doDotAny:
         // scanned a ".", meaning match any single character.
         {
             n = pushNewNode(RBBINode::setRef);
             findSetFor(UnicodeString(TRUE, kAny, 3), n);
             n->fFirstPos = fScanIndex;
             n->fLastPos  = fNextIndex;
             fRB->fRules.extractBetween(n->fFirstPos, n->fLastPos, n->fText);
             break;
         }
     case doSlash:
         // Scanned a '/', which identifies a look-ahead break position in a rule.
         n = pushNewNode(RBBINode::lookAhead);
         n->fVal      = fRuleNum;
         n->fFirstPos = fScanIndex;
         n->fLastPos  = fNextIndex;
         fRB->fRules.extractBetween(n->fFirstPos, n->fLastPos, n->fText);
         fLookAheadRule = TRUE;
         break;
     case doStartTagValue:
         // Scanned a '{', the opening delimiter for a tag value within a rule.
         n = pushNewNode(RBBINode::tag);
         n->fVal      = 0;
         n->fFirstPos = fScanIndex;
         n->fLastPos  = fNextIndex;
         break;
     case doTagDigit:
         // Just scanned a decimal digit that's part of a tag value
         {
             n = fNodeStack[fNodeStackPtr];
             uint32_t v = u_charDigitValue(fC.fChar);
             U_ASSERT(v < 10);
             n->fVal = n->fVal*10 + v;
             break;
         }
     case doTagValue:
         n = fNodeStack[fNodeStackPtr];
         n->fLastPos = fNextIndex;
         fRB->fRules.extractBetween(n->fFirstPos, n->fLastPos, n->fText);
         break;
     case doTagExpectedError:
         error(U_BRK_MALFORMED_RULE_TAG);
         returnVal = FALSE;
         break;
     case doOptionStart:
         // Scanning a !!option.   At the start of string.
         fOptionStart = fScanIndex;
         break;
     case doOptionEnd:
         {
             UnicodeString opt(fRB->fRules, fOptionStart, fScanIndex-fOptionStart);
             if (opt == UNICODE_STRING("chain", 5)) {
                 fRB->fChainRules = TRUE;
             } else if (opt == UNICODE_STRING("LBCMNoChain", 11)) {
                 fRB->fLBCMNoChain = TRUE;
             } else if (opt == UNICODE_STRING("forward", 7)) {
                 fRB->fDefaultTree   = &fRB->fForwardTree;
             } else if (opt == UNICODE_STRING("reverse", 7)) {
                 fRB->fDefaultTree   = &fRB->fReverseTree;
             } else if (opt == UNICODE_STRING("safe_forward", 12)) {
                 fRB->fDefaultTree   = &fRB->fSafeFwdTree;
             } else if (opt == UNICODE_STRING("safe_reverse", 12)) {
                 fRB->fDefaultTree   = &fRB->fSafeRevTree;
             } else if (opt == UNICODE_STRING("lookAheadHardBreak", 18)) {
                 fRB->fLookAheadHardBreak = TRUE;
             } else {
                 error(U_BRK_UNRECOGNIZED_OPTION);
             }
         }
         break;
     case doReverseDir:
         fReverseRule = TRUE;
         break;
     case doStartVariableName:
         n = pushNewNode(RBBINode::varRef);
         if (U_FAILURE(*fRB->fStatus)) {
             break;
         }
         n->fFirstPos = fScanIndex;
         break;
     case doEndVariableName:
         n = fNodeStack[fNodeStackPtr];
         if (n==NULL || n->fType != RBBINode::varRef) {
             error(U_BRK_INTERNAL_ERROR);
             break;
         }
         n->fLastPos = fScanIndex;
         fRB->fRules.extractBetween(n->fFirstPos+1, n->fLastPos, n->fText);
         // Look the newly scanned name up in the symbol table
         //   If there's an entry, set the l. child of the var ref to the replacement expression.
         //   (We also pass through here when scanning assignments, but no harm is done, other
         //    than a slight wasted effort that seems hard to avoid.  Lookup will be null)
         n->fLeftChild = fSymbolTable->lookupNode(n->fText);
         break;
     case doCheckVarDef:
         n = fNodeStack[fNodeStackPtr];
         if (n->fLeftChild == NULL) {
             error(U_BRK_UNDEFINED_VARIABLE);
             returnVal = FALSE;
         }
         break;
     case doExprFinished:
         break;
     case doRuleErrorAssignExpr:
         error(U_BRK_ASSIGN_ERROR);
         returnVal = FALSE;
         break;
     case doExit:
         returnVal = FALSE;
         break;
     case doScanUnicodeSet:
         scanSet();
         break;
     default:
         error(U_BRK_INTERNAL_ERROR);
         returnVal = FALSE;
         break;
     }
     return returnVal;
 }
 //------------------------------------------------------------------------------
 //
 //  Error         Report a rule parse error.
 //                Only report it if no previous error has been recorded.
 //
 //------------------------------------------------------------------------------
 void RBBIRuleScanner::error(UErrorCode e) {
     if (U_SUCCESS(*fRB->fStatus)) {
         *fRB->fStatus = e;
         if (fRB->fParseError) {
             fRB->fParseError->line  = fLineNum;
             fRB->fParseError->offset = fCharNum;
             fRB->fParseError->preContext[0] = 0;
             fRB->fParseError->preContext[0] = 0;
         }
     }
 }
 //------------------------------------------------------------------------------
 //
 //  fixOpStack   The parse stack holds partially assembled chunks of the parse tree.
 //               An entry on the stack may be as small as a single setRef node,
 //               or as large as the parse tree
 //               for an entire expression (this will be the one item left on the stack
 //               when the parsing of an RBBI rule completes.
 //
 //               This function is called when a binary operator is encountered.
 //               It looks back up the stack for operators that are not yet associated
 //               with a right operand, and if the precedence of the stacked operator >=
 //               the precedence of the current operator, binds the operand left,
 //               to the previously encountered operator.
 //
 //------------------------------------------------------------------------------
 void RBBIRuleScanner::fixOpStack(RBBINode::OpPrecedence p) {
     RBBINode *n;
     // printNodeStack("entering fixOpStack()");
     for (;;) {
         n = fNodeStack[fNodeStackPtr-1];   // an operator node
         if (n->fPrecedence == 0) {
             RBBIDebugPuts("RBBIRuleScanner::fixOpStack, bad operator node");
             error(U_BRK_INTERNAL_ERROR);
             return;
         }
         if (n->fPrecedence < p || n->fPrecedence <= RBBINode::precLParen) {
             // The most recent operand goes with the current operator,
             //   not with the previously stacked one.
             break;
         }
             // Stack operator is a binary op  ( '|' or concatenation)
             //   TOS operand becomes right child of this operator.
             //   Resulting subexpression becomes the TOS operand.
             n->fRightChild = fNodeStack[fNodeStackPtr];
             fNodeStack[fNodeStackPtr]->fParent = n;
             fNodeStackPtr--;
         // printNodeStack("looping in fixOpStack()   ");
     }
     if (p <= RBBINode::precLParen) {
         // Scan is at a right paren or end of expression.
         //  The scanned item must match the stack, or else there was an error.
         //  Discard the left paren (or start expr) node from the stack,
             //  leaving the completed (sub)expression as TOS.
             if (n->fPrecedence != p) {
                 // Right paren encountered matched start of expression node, or
                 // end of expression matched with a left paren node.
                 error(U_BRK_MISMATCHED_PAREN);
             }
             fNodeStack[fNodeStackPtr-1] = fNodeStack[fNodeStackPtr];
             fNodeStackPtr--;
             // Delete the now-discarded LParen or Start node.
             delete n;
     }
     // printNodeStack("leaving fixOpStack()");
 }
 //------------------------------------------------------------------------------
 //
 //   findSetFor    given a UnicodeString,
 //                  - find the corresponding Unicode Set  (uset node)
 //                         (create one if necessary)
 //                  - Set fLeftChild of the caller's node (should be a setRef node)
 //                         to the uset node
 //                 Maintain a hash table of uset nodes, so the same one is always used
 //                    for the same string.
 //                 If a "to adopt" set is provided and we haven't seen this key before,
 //                    add the provided set to the hash table.
 //                 If the string is one (32 bit) char in length, the set contains
 //                    just one element which is the char in question.
 //                 If the string is "any", return a set containing all chars.
 //
 //------------------------------------------------------------------------------
 void RBBIRuleScanner::findSetFor(const UnicodeString &s, RBBINode *node, UnicodeSet *setToAdopt) {
     RBBISetTableEl   *el;
     // First check whether we've already cached a set for this string.
     // If so, just use the cached set in the new node.
     //   delete any set provided by the caller, since we own it.
     el = (RBBISetTableEl *)uhash_get(fSetTable, &s);
     if (el != NULL) {
         delete setToAdopt;
         node->fLeftChild = el->val;
         U_ASSERT(node->fLeftChild->fType == RBBINode::uset);
         return;
     }
     // Haven't seen this set before.
     // If the caller didn't provide us with a prebuilt set,
     //   create a new UnicodeSet now.
     if (setToAdopt == NULL) {
         if (s.compare(kAny, -1) == 0) {
             setToAdopt = new UnicodeSet(0x000000, 0x10ffff);
         } else {
             UChar32 c;
             c = s.char32At(0);
             setToAdopt = new UnicodeSet(c, c);
         }
     }
     //
     // Make a new uset node to refer to this UnicodeSet
     // This new uset node becomes the child of the caller's setReference node.
     //
     RBBINode *usetNode    = new RBBINode(RBBINode::uset);
     if (usetNode == NULL) {
         error(U_MEMORY_ALLOCATION_ERROR);
         return;
     }
     usetNode->fInputSet   = setToAdopt;
     usetNode->fParent     = node;
     node->fLeftChild      = usetNode;
     usetNode->fText = s;
     //
     // Add the new uset node to the list of all uset nodes.
     //
     fRB->fUSetNodes->addElement(usetNode, *fRB->fStatus);
     //
     // Add the new set to the set hash table.
     //
     el      = (RBBISetTableEl *)uprv_malloc(sizeof(RBBISetTableEl));
     UnicodeString *tkey = new UnicodeString(s);
     if (tkey == NULL || el == NULL || setToAdopt == NULL) {
         // Delete to avoid memory leak
         delete tkey;
         tkey = NULL;
         uprv_free(el);
         el = NULL;
         delete setToAdopt;
         setToAdopt = NULL;
         error(U_MEMORY_ALLOCATION_ERROR);
         return;
     }
     el->key = tkey;
     el->val = usetNode;
     uhash_put(fSetTable, el->key, el, fRB->fStatus);
     return;
 }
 //
 //  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      chBackSlash = 0x5c;      // '\'  introduces a char escape
 static const UChar      chLParen    = 0x28;
 static const UChar      chRParen    = 0x29;
 //------------------------------------------------------------------------------
 //
 //  stripRules    Return a rules string without unnecessary
 //                characters.
 //
 //------------------------------------------------------------------------------
 UnicodeString RBBIRuleScanner::stripRules(const UnicodeString &rules) {
     UnicodeString strippedRules;
     int rulesLength = rules.length();
     for (int idx = 0; idx < rulesLength; ) {
         UChar ch = rules[idx++];
         if (ch == chPound) {
             while (idx < rulesLength
                 && ch != chCR && ch != chLF && ch != chNEL)
             {
                 ch = rules[idx++];
             }
         }
         if (!u_isISOControl(ch)) {
             strippedRules.append(ch);
         }
     }
     // strippedRules = strippedRules.unescape();
     return strippedRules;
 }
 //------------------------------------------------------------------------------
 //
 //  nextCharLL    Low Level Next Char from rule input source.
 //                Get a char from the input character iterator,
 //                keep track of input position for error reporting.
 //
 //------------------------------------------------------------------------------
 UChar32  RBBIRuleScanner::nextCharLL() {
     UChar32  ch;
     if (fNextIndex >= fRB->fRules.length()) {
         return (UChar32)-1;
     }
     ch         = fRB->fRules.char32At(fNextIndex);
     fNextIndex = fRB->fRules.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_BRK_NEW_LINE_IN_QUOTED_STRING);
             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;
 }
 //------------------------------------------------------------------------------
 //
 //   nextChar     for rules scanning.  At this level, we handle stripping
 //                out comments and processing backslash character escapes.
 //                The rest of the rules grammar is handled at the next level up.
 //
 //------------------------------------------------------------------------------
 void RBBIRuleScanner::nextChar(RBBIRuleChar &c) {
     // Unicode Character constants needed for the processing done by nextChar(),
     //   in hex because literals wont work on EBCDIC machines.
     fScanIndex = fNextIndex;
     c.fChar    = nextCharLL();
     c.fEscaped = FALSE;
     //
     //  check for '' sequence.
     //  These are recognized in all contexts, whether in quoted text or not.
     //
     if (c.fChar == chApos) {
         if (fRB->fRules.char32At(fNextIndex) == chApos) {
             c.fChar    = nextCharLL();        // get nextChar officially so character counts
             c.fEscaped = TRUE;                //   stay correct.
         }
         else
         {
             // Single quote, by itself.
             //   Toggle quoting mode.
             //   Return either '('  or ')', because quotes cause a grouping of the quoted text.
             fQuoteMode = !fQuoteMode;
             if (fQuoteMode == TRUE) {
                 c.fChar = chLParen;
             } else {
                 c.fChar = chRParen;
             }
             c.fEscaped = FALSE;      // The paren that we return is not escaped.
             return;
         }
     }
     if (fQuoteMode) {
         c.fEscaped = TRUE;
     }
     else
     {
         // We are not in a 'quoted region' of the source.
         //
         if (c.fChar == chPound) {
             // Start of a comment.  Consume the rest of it.
             //  The new-line char that terminates the comment is always returned.
             //  It will be treated as white-space, and serves to break up anything
             //    that might otherwise incorrectly clump together with a comment in
             //    the middle (a variable name, for example.)
             for (;;) {
                 c.fChar = nextCharLL();
                 if (c.fChar == (UChar32)-1 ||  // EOF
                     c.fChar == chCR     ||
                     c.fChar == chLF     ||
                     c.fChar == chNEL    ||
                     c.fChar == chLS)       {break;}
             }
         }
         if (c.fChar == (UChar32)-1) {
             return;
         }
         //
         //  check for backslash escaped characters.
         //  Use UnicodeString::unescapeAt() to handle them.
         //
         if (c.fChar == chBackSlash) {
             c.fEscaped = TRUE;
             int32_t startX = fNextIndex;
             c.fChar = fRB->fRules.unescapeAt(fNextIndex);
             if (fNextIndex == startX) {
                 error(U_BRK_HEX_DIGITS_EXPECTED);
             }
             fCharNum += fNextIndex-startX;
         }
     }
     // putc(c.fChar, stdout);
 }
 //------------------------------------------------------------------------------
 //
 //  Parse RBBI rules.   The state machine for rules parsing is here.
 //                      The state tables are hand-written in the file rbbirpt.txt,
 //                      and converted to the form used here by a perl
 //                      script rbbicst.pl
 //
 //------------------------------------------------------------------------------
 void RBBIRuleScanner::parse() {
     uint16_t                state;
     const RBBIRuleTableEl  *tableEl;
     if (U_FAILURE(*fRB->fStatus)) {
         return;
     }
     state = 1;
     nextChar(fC);
     //
     // Main loop for the rule parsing state machine.
     //   Runs once per state transition.
     //   Each time through optionally performs, depending on the state table,
     //      - an advance to the the next input char
     //      - an action to be performed.
     //      - pushing or popping a state to/from the local state return stack.
     //
     for (;;) {
         //  Bail out if anything has gone wrong.
         //  RBBI rule file parsing stops on the first error encountered.
         if (U_FAILURE(*fRB->fStatus)) {
             break;
         }
         // Quit if state == 0.  This is the normal way to exit the state machine.
         //
         if (state == 0) {
             break;
         }
         // Find the state table element that matches the input char from the rule, 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];
         #ifdef RBBI_DEBUG
             if (fRB->fDebugEnv && uprv_strstr(fRB->fDebugEnv, "scan")) {
                 RBBIDebugPrintf("char, line, col = (\'%c\', %d, %d)    state=%s ",
                     fC.fChar, fLineNum, fCharNum, RBBIRuleStateNames[state]);
             }
         #endif
         for (;;) {
             #ifdef RBBI_DEBUG
                 if (fRB->fDebugEnv && uprv_strstr(fRB->fDebugEnv, "scan")) { RBBIDebugPrintf(".");}
             #endif
             if (tableEl->fCharClass < 127 && fC.fEscaped == FALSE &&   tableEl->fCharClass == fC.fChar) {
                 // Table row specified an individual character, not a set, and
                 //   the input character is not escaped, 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.fEscaped)  {
                 // Table row specified "escaped" and the char was escaped.
                 break;
             }
             if (tableEl->fCharClass == 253 && fC.fEscaped &&
                 (fC.fChar == 0x50 || fC.fChar == 0x70 ))  {
                 // Table row specified "escaped P" and the char is either 'p' or 'P'.
                 break;
             }
             if (tableEl->fCharClass == 252 && 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.fEscaped == FALSE &&                                      //   char is not escaped &&
                 fC.fChar != (UChar32)-1) {                                   //   char is not EOF
                 U_ASSERT((tableEl->fCharClass-128) < LENGTHOF(fRuleSets));
                 if (fRuleSets[tableEl->fCharClass-128].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++;
         }
         if (fRB->fDebugEnv && uprv_strstr(fRB->fDebugEnv, "scan")) { RBBIDebugPuts("");}
         //
         // 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((int32_t)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_BRK_INTERNAL_ERROR);
                 RBBIDebugPuts("RBBIRuleScanner::parse() - state stack overflow.");
                 fStackPtr--;
             }
             fStack[fStackPtr] = tableEl->fPushState;
         }
         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) {
                 error(U_BRK_INTERNAL_ERROR);
                 RBBIDebugPuts("RBBIRuleScanner::parse() - state stack underflow.");
                 fStackPtr++;
             }
         }
     }
     //
     // If there were NO user specified reverse rules, set up the equivalent of ".*;"
     //
     if (fRB->fReverseTree == NULL) {
         fRB->fReverseTree  = pushNewNode(RBBINode::opStar);
         RBBINode  *operand = pushNewNode(RBBINode::setRef);
         findSetFor(UnicodeString(TRUE, kAny, 3), operand);
         fRB->fReverseTree->fLeftChild = operand;
         operand->fParent              = fRB->fReverseTree;
         fNodeStackPtr -= 2;
     }
     //
     // Parsing of the input RBBI rules is complete.
     // We now have a parse tree for the rule expressions
     // and a list of all UnicodeSets that are referenced.
     //
 #ifdef RBBI_DEBUG
     if (fRB->fDebugEnv && uprv_strstr(fRB->fDebugEnv, "symbols")) {fSymbolTable->rbbiSymtablePrint();}
     if (fRB->fDebugEnv && uprv_strstr(fRB->fDebugEnv, "ptree"))
     {
         RBBIDebugPrintf("Completed Forward Rules Parse Tree...\n");
         fRB->fForwardTree->printTree(TRUE);
         RBBIDebugPrintf("\nCompleted Reverse Rules Parse Tree...\n");
         fRB->fReverseTree->printTree(TRUE);
         RBBIDebugPrintf("\nCompleted Safe Point Forward Rules Parse Tree...\n");
         fRB->fSafeFwdTree->printTree(TRUE);
         RBBIDebugPrintf("\nCompleted Safe Point Reverse Rules Parse Tree...\n");
         fRB->fSafeRevTree->printTree(TRUE);
     }
 #endif
 }
 //------------------------------------------------------------------------------
 //
 //  printNodeStack     for debugging...
 //
 //------------------------------------------------------------------------------
 #ifdef RBBI_DEBUG
 void RBBIRuleScanner::printNodeStack(const char *title) {
     int i;
     RBBIDebugPrintf("%s.  Dumping node stack...\n", title);
     for (i=fNodeStackPtr; i>0; i--) {fNodeStack[i]->printTree(TRUE);}
 }
 #endif
 //------------------------------------------------------------------------------
 //
 //  pushNewNode   create a new RBBINode of the specified type and push it
 //                onto the stack of nodes.
 //
 //------------------------------------------------------------------------------
 RBBINode  *RBBIRuleScanner::pushNewNode(RBBINode::NodeType  t) {
     fNodeStackPtr++;
     if (fNodeStackPtr >= kStackSize) {
         error(U_BRK_INTERNAL_ERROR);
         RBBIDebugPuts("RBBIRuleScanner::pushNewNode - stack overflow.");
         *fRB->fStatus = U_BRK_INTERNAL_ERROR;
         return NULL;
     }
     fNodeStack[fNodeStackPtr] = new RBBINode(t);
     if (fNodeStack[fNodeStackPtr] == NULL) {
         *fRB->fStatus = U_MEMORY_ALLOCATION_ERROR;
     }
     return fNodeStack[fNodeStackPtr];
 }
 //------------------------------------------------------------------------------
 //
 //  scanSet    Construct a UnicodeSet from the text at the current scan
 //             position.  Advance the scan position to the first character
 //             after the set.
 //
 //             A new RBBI setref node referring to the set is pushed onto the node
 //             stack.
 //
 //             The scan position is normally under the control of the state machine
 //             that controls rule parsing.  UnicodeSets, however, are parsed by
 //             the UnicodeSet constructor, not by the RBBI rule parser.
 //
 //------------------------------------------------------------------------------
 void RBBIRuleScanner::scanSet() {
     UnicodeSet    *uset;
     ParsePosition  pos;
     int            startPos;
     int            i;
     if (U_FAILURE(*fRB->fStatus)) {
         return;
     }
     pos.setIndex(fScanIndex);
     startPos = fScanIndex;
     UErrorCode localStatus = U_ZERO_ERROR;
     uset = new UnicodeSet();
     if (uset == NULL) {
         localStatus = U_MEMORY_ALLOCATION_ERROR;
     } else {
         uset->applyPatternIgnoreSpace(fRB->fRules, pos, fSymbolTable, 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.
         #ifdef RBBI_DEBUG
             RBBIDebugPrintf("UnicodeSet parse postion.ErrorIndex = %d\n", pos.getIndex());
         #endif
         error(localStatus);
         delete uset;
         return;
     }
     // Verify that the set contains at least one code point.
     //
     U_ASSERT(uset!=NULL);
     if (uset->isEmpty()) {
         // This set is empty.
         //  Make it an error, because it almost certainly is not what the user wanted.
         //  Also, avoids having to think about corner cases in the tree manipulation code
         //   that occurs later on.
         error(U_BRK_RULE_EMPTY_SET);
         delete uset;
         return;
     }
     // Advance the RBBI parse postion over the UnicodeSet pattern.
     //   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();
     }
     if (U_SUCCESS(*fRB->fStatus)) {
         RBBINode         *n;
         n = pushNewNode(RBBINode::setRef);
         n->fFirstPos = startPos;
         n->fLastPos  = fNextIndex;
         fRB->fRules.extractBetween(n->fFirstPos, n->fLastPos, n->fText);
         //  findSetFor() serves several purposes here:
         //     - Adopts storage for the UnicodeSet, will be responsible for deleting.
         //     - Mantains collection of all sets in use, needed later for establishing
         //          character categories for run time engine.
         //     - Eliminates mulitiple instances of the same set.
         //     - Creates a new uset node if necessary (if this isn't a duplicate.)
         findSetFor(n->fText, n, uset);
     }
 }
 U_NAMESPACE_END
 #endif /* #if !UCONFIG_NO_BREAK_ITERATION */

The Tor Browser / annotate

intl/icu/source/common/rbbiscan.cpp@129ffea94266 (annotated)

intl/icu/source/common/rbbiscan.cpp