tclRegexp.c 30.9 KB
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/*
 * tclRegexp.c --
 *
 *	This file contains the public interfaces to the Tcl regular expression
 *	mechanism.
 *
 * Copyright (c) 1998 by Sun Microsystems, Inc.
 * Copyright (c) 1998-1999 by Scriptics Corporation.
 *
 * See the file "license.terms" for information on usage and redistribution of
 * this file, and for a DISCLAIMER OF ALL WARRANTIES.
 */

#include "tclInt.h"
#include "tclRegexp.h"

/*
 *----------------------------------------------------------------------
 * The routines in this file use Henry Spencer's regular expression package
 * contained in the following additional source files:
 *
 *	regc_color.c	regc_cvec.c	regc_lex.c
 *	regc_nfa.c	regcomp.c	regcustom.h
 *	rege_dfa.c	regerror.c	regerrs.h
 *	regex.h		regexec.c	regfree.c
 *	regfronts.c	regguts.h
 *
 * Copyright (c) 1998 Henry Spencer.  All rights reserved.
 *
 * Development of this software was funded, in part, by Cray Research Inc.,
 * UUNET Communications Services Inc., Sun Microsystems Inc., and Scriptics
 * Corporation, none of whom are responsible for the results. The author
 * thanks all of them.
 *
 * Redistribution and use in source and binary forms -- with or without
 * modification -- are permitted for any purpose, provided that
 * redistributions in source form retain this entire copyright notice and
 * indicate the origin and nature of any modifications.
 *
 * I'd appreciate being given credit for this package in the documentation of
 * software which uses it, but that is not a requirement.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
 * HENRY SPENCER BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * *** NOTE: this code has been altered slightly for use in Tcl: ***
 * *** 1. Names have been changed, e.g. from re_comp to		 ***
 * ***    TclRegComp, to avoid clashes with other		 ***
 * ***    regexp implementations used by applications.		 ***
 */

/*
 * Thread local storage used to maintain a per-thread cache of compiled
 * regular expressions.
 */

#define NUM_REGEXPS 30

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typedef struct {
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    int initialized;		/* Set to 1 when the module is initialized. */
    char *patterns[NUM_REGEXPS];/* Strings corresponding to compiled regular
				 * expression patterns. NULL means that this
				 * slot isn't used. Malloc-ed. */
    int patLengths[NUM_REGEXPS];/* Number of non-null characters in
				 * corresponding entry in patterns. -1 means
				 * entry isn't used. */
    struct TclRegexp *regexps[NUM_REGEXPS];
				/* Compiled forms of above strings. Also
				 * malloc-ed, or NULL if not in use yet. */
} ThreadSpecificData;

static Tcl_ThreadDataKey dataKey;

/*
 * Declarations for functions used only in this file.
 */

static TclRegexp *	CompileRegexp(Tcl_Interp *interp, const char *pattern,
			    int length, int flags);
static void		DupRegexpInternalRep(Tcl_Obj *srcPtr,
			    Tcl_Obj *copyPtr);
static void		FinalizeRegexp(ClientData clientData);
static void		FreeRegexp(TclRegexp *regexpPtr);
static void		FreeRegexpInternalRep(Tcl_Obj *objPtr);
static int		RegExpExecUniChar(Tcl_Interp *interp, Tcl_RegExp re,
			    const Tcl_UniChar *uniString, int numChars,
			    int nmatches, int flags);
static int		SetRegexpFromAny(Tcl_Interp *interp, Tcl_Obj *objPtr);

/*
 * The regular expression Tcl object type. This serves as a cache of the
 * compiled form of the regular expression.
 */

const Tcl_ObjType tclRegexpType = {
    "regexp",				/* name */
    FreeRegexpInternalRep,		/* freeIntRepProc */
    DupRegexpInternalRep,		/* dupIntRepProc */
    NULL,				/* updateStringProc */
    SetRegexpFromAny			/* setFromAnyProc */
};

/*
 *----------------------------------------------------------------------
 *
 * Tcl_RegExpCompile --
 *
 *	Compile a regular expression into a form suitable for fast matching.
 *	This function is DEPRECATED in favor of the object version of the
 *	command.
 *
 * Results:
 *	The return value is a pointer to the compiled form of string, suitable
 *	for passing to Tcl_RegExpExec. This compiled form is only valid up
 *	until the next call to this function, so don't keep these around for a
 *	long time! If an error occurred while compiling the pattern, then NULL
 *	is returned and an error message is left in the interp's result.
 *
 * Side effects:
 *	Updates the cache of compiled regexps.
 *
 *----------------------------------------------------------------------
 */

Tcl_RegExp
Tcl_RegExpCompile(
    Tcl_Interp *interp,		/* For use in error reporting and to access
				 * the interp regexp cache. */
    const char *pattern)	/* String for which to produce compiled
				 * regular expression. */
{
    return (Tcl_RegExp) CompileRegexp(interp, pattern, (int) strlen(pattern),
	    REG_ADVANCED);
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_RegExpExec --
 *
 *	Execute the regular expression matcher using a compiled form of a
 *	regular expression and save information about any match that is found.
 *
 * Results:
 *	If an error occurs during the matching operation then -1 is returned
 *	and the interp's result contains an error message. Otherwise the
 *	return value is 1 if a matching range is found and 0 if there is no
 *	matching range.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_RegExpExec(
    Tcl_Interp *interp,		/* Interpreter to use for error reporting. */
    Tcl_RegExp re,		/* Compiled regular expression; must have been
				 * returned by previous call to
				 * Tcl_GetRegExpFromObj. */
    const char *text,		/* Text against which to match re. */
    const char *start)		/* If text is part of a larger string, this
				 * identifies beginning of larger string, so
				 * that "^" won't match. */
{
    int flags, result, numChars;
    TclRegexp *regexp = (TclRegexp *) re;
    Tcl_DString ds;
    const Tcl_UniChar *ustr;

    /*
     * If the starting point is offset from the beginning of the buffer, then
     * we need to tell the regexp engine not to match "^".
     */

    if (text > start) {
	flags = REG_NOTBOL;
    } else {
	flags = 0;
    }

    /*
     * Remember the string for use by Tcl_RegExpRange().
     */

    regexp->string = text;
    regexp->objPtr = NULL;

    /*
     * Convert the string to Unicode and perform the match.
     */

    Tcl_DStringInit(&ds);
    ustr = Tcl_UtfToUniCharDString(text, -1, &ds);
    numChars = Tcl_DStringLength(&ds) / sizeof(Tcl_UniChar);
    result = RegExpExecUniChar(interp, re, ustr, numChars, -1 /* nmatches */,
	    flags);
    Tcl_DStringFree(&ds);

    return result;
}

/*
 *---------------------------------------------------------------------------
 *
 * Tcl_RegExpRange --
 *
 *	Returns pointers describing the range of a regular expression match,
 *	or one of the subranges within the match.
 *
 * Results:
 *	The variables at *startPtr and *endPtr are modified to hold the
 *	addresses of the endpoints of the range given by index. If the
 *	specified range doesn't exist then NULLs are returned.
 *
 * Side effects:
 *	None.
 *
 *---------------------------------------------------------------------------
 */

void
Tcl_RegExpRange(
    Tcl_RegExp re,		/* Compiled regular expression that has been
				 * passed to Tcl_RegExpExec. */
    int index,			/* 0 means give the range of the entire match,
				 * > 0 means give the range of a matching
				 * subrange. */
    const char **startPtr,	/* Store address of first character in
				 * (sub-)range here. */
    const char **endPtr)	/* Store address of character just after last
				 * in (sub-)range here. */
{
    TclRegexp *regexpPtr = (TclRegexp *) re;
    const char *string;

    if ((size_t) index > regexpPtr->re.re_nsub) {
	*startPtr = *endPtr = NULL;
    } else if (regexpPtr->matches[index].rm_so < 0) {
	*startPtr = *endPtr = NULL;
    } else {
	if (regexpPtr->objPtr) {
	    string = TclGetString(regexpPtr->objPtr);
	} else {
	    string = regexpPtr->string;
	}
	*startPtr = Tcl_UtfAtIndex(string, regexpPtr->matches[index].rm_so);
	*endPtr = Tcl_UtfAtIndex(string, regexpPtr->matches[index].rm_eo);
    }
}

/*
 *---------------------------------------------------------------------------
 *
 * RegExpExecUniChar --
 *
 *	Execute the regular expression matcher using a compiled form of a
 *	regular expression and save information about any match that is found.
 *
 * Results:
 *	If an error occurs during the matching operation then -1 is returned
 *	and an error message is left in interp's result. Otherwise the return
 *	value is 1 if a matching range was found or 0 if there was no matching
 *	range.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static int
RegExpExecUniChar(
    Tcl_Interp *interp,		/* Interpreter to use for error reporting. */
    Tcl_RegExp re,		/* Compiled regular expression; returned by a
				 * previous call to Tcl_GetRegExpFromObj */
    const Tcl_UniChar *wString,	/* String against which to match re. */
    int numChars,		/* Length of Tcl_UniChar string (must be
				 * >=0). */
    int nmatches,		/* How many subexpression matches (counting
				 * the whole match as subexpression 0) are of
				 * interest. -1 means "don't know". */
    int flags)			/* Regular expression flags. */
{
    int status;
    TclRegexp *regexpPtr = (TclRegexp *) re;
    size_t last = regexpPtr->re.re_nsub + 1;
    size_t nm = last;

    if (nmatches >= 0 && (size_t) nmatches < nm) {
	nm = (size_t) nmatches;
    }

    status = TclReExec(&regexpPtr->re, wString, (size_t) numChars,
	    &regexpPtr->details, nm, regexpPtr->matches, flags);

    /*
     * Check for errors.
     */

    if (status != REG_OKAY) {
	if (status == REG_NOMATCH) {
	    return 0;
	}
	if (interp != NULL) {
	    TclRegError(interp, "error while matching regular expression: ",
		    status);
	}
	return -1;
    }
    return 1;
}

/*
 *---------------------------------------------------------------------------
 *
 * TclRegExpRangeUniChar --
 *
 *	Returns pointers describing the range of a regular expression match,
 *	or one of the subranges within the match, or the hypothetical range
 *	represented by the rm_extend field of the rm_detail_t.
 *
 * Results:
 *	The variables at *startPtr and *endPtr are modified to hold the
 *	offsets of the endpoints of the range given by index. If the specified
 *	range doesn't exist then -1s are supplied.
 *
 * Side effects:
 *	None.
 *
 *---------------------------------------------------------------------------
 */

void
TclRegExpRangeUniChar(
    Tcl_RegExp re,		/* Compiled regular expression that has been
				 * passed to Tcl_RegExpExec. */
    int index,			/* 0 means give the range of the entire match,
				 * > 0 means give the range of a matching
				 * subrange, -1 means the range of the
				 * rm_extend field. */
    int *startPtr,		/* Store address of first character in
				 * (sub-)range here. */
    int *endPtr)		/* Store address of character just after last
				 * in (sub-)range here. */
{
    TclRegexp *regexpPtr = (TclRegexp *) re;

    if ((regexpPtr->flags&REG_EXPECT) && index == -1) {
	*startPtr = regexpPtr->details.rm_extend.rm_so;
	*endPtr = regexpPtr->details.rm_extend.rm_eo;
    } else if ((size_t) index > regexpPtr->re.re_nsub) {
	*startPtr = -1;
	*endPtr = -1;
    } else {
	*startPtr = regexpPtr->matches[index].rm_so;
	*endPtr = regexpPtr->matches[index].rm_eo;
    }
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_RegExpMatch --
 *
 *	See if a string matches a regular expression.
 *
 * Results:
 *	If an error occurs during the matching operation then -1 is returned
 *	and the interp's result contains an error message. Otherwise the
 *	return value is 1 if "text" matches "pattern" and 0 otherwise.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_RegExpMatch(
    Tcl_Interp *interp,		/* Used for error reporting. May be NULL. */
    const char *text,		/* Text to search for pattern matches. */
    const char *pattern)	/* Regular expression to match against text. */
{
    Tcl_RegExp re = Tcl_RegExpCompile(interp, pattern);

    if (re == NULL) {
	return -1;
    }
    return Tcl_RegExpExec(interp, re, text, text);
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_RegExpExecObj --
 *
 *	Execute a precompiled regexp against the given object.
 *
 * Results:
 *	If an error occurs during the matching operation then -1 is returned
 *	and the interp's result contains an error message. Otherwise the
 *	return value is 1 if "string" matches "pattern" and 0 otherwise.
 *
 * Side effects:
 *	Converts the object to a Unicode object.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_RegExpExecObj(
    Tcl_Interp *interp,		/* Interpreter to use for error reporting. */
    Tcl_RegExp re,		/* Compiled regular expression; must have been
				 * returned by previous call to
				 * Tcl_GetRegExpFromObj. */
    Tcl_Obj *textObj,		/* Text against which to match re. */
    int offset,			/* Character index that marks where matching
				 * should begin. */
    int nmatches,		/* How many subexpression matches (counting
				 * the whole match as subexpression 0) are of
				 * interest. -1 means all of them. */
    int flags)			/* Regular expression execution flags. */
{
    TclRegexp *regexpPtr = (TclRegexp *) re;
    Tcl_UniChar *udata;
    int length;
    int reflags = regexpPtr->flags;
#define TCL_REG_GLOBOK_FLAGS \
	(TCL_REG_ADVANCED | TCL_REG_NOSUB | TCL_REG_NOCASE)

    /*
     * Take advantage of the equivalent glob pattern, if one exists.
     * This is possible based only on the right mix of incoming flags (0)
     * and regexp compile flags.
     */
    if ((offset == 0) && (nmatches == 0) && (flags == 0)
	    && !(reflags & ~TCL_REG_GLOBOK_FLAGS)
	    && (regexpPtr->globObjPtr != NULL)) {
	int nocase = (reflags & TCL_REG_NOCASE) ? TCL_MATCH_NOCASE : 0;

	/*
	 * Pass to TclStringMatchObj for obj-specific handling.
	 * XXX: Currently doesn't take advantage of exact-ness that
	 * XXX: TclReToGlob tells us about
	 */

	return TclStringMatchObj(textObj, regexpPtr->globObjPtr, nocase);
    }

    /*
     * Save the target object so we can extract strings from it later.
     */

    regexpPtr->string = NULL;
    regexpPtr->objPtr = textObj;

    udata = Tcl_GetUnicodeFromObj(textObj, &length);

    if (offset > length) {
	offset = length;
    }
    udata += offset;
    length -= offset;

    return RegExpExecUniChar(interp, re, udata, length, nmatches, flags);
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_RegExpMatchObj --
 *
 *	See if an object matches a regular expression.
 *
 * Results:
 *	If an error occurs during the matching operation then -1 is returned
 *	and the interp's result contains an error message. Otherwise the
 *	return value is 1 if "text" matches "pattern" and 0 otherwise.
 *
 * Side effects:
 *	Changes the internal rep of the pattern and string objects.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_RegExpMatchObj(
    Tcl_Interp *interp,		/* Used for error reporting. May be NULL. */
    Tcl_Obj *textObj,		/* Object containing the String to search. */
    Tcl_Obj *patternObj)	/* Regular expression to match against
				 * string. */
{
    Tcl_RegExp re;

    /*
     * For performance reasons, first try compiling the RE without support for
     * subexpressions. On failure, try again without TCL_REG_NOSUB in case the
     * RE has backreferences in it. Closely related to [Bug 1366683]. If this
     * still fails, an error message will be left in the interpreter.
     */

    if (!(re = Tcl_GetRegExpFromObj(interp, patternObj,
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	    TCL_REG_ADVANCED | TCL_REG_NOSUB))
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     && !(re = Tcl_GetRegExpFromObj(interp, patternObj, TCL_REG_ADVANCED))) {
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	return -1;
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    }
    return Tcl_RegExpExecObj(interp, re, textObj, 0 /* offset */,
	    0 /* nmatches */, 0 /* flags */);
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_RegExpGetInfo --
 *
 *	Retrieve information about the current match.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

void
Tcl_RegExpGetInfo(
    Tcl_RegExp regexp,		/* Pattern from which to get subexpressions. */
    Tcl_RegExpInfo *infoPtr)	/* Match information is stored here. */
{
    TclRegexp *regexpPtr = (TclRegexp *) regexp;

    infoPtr->nsubs = regexpPtr->re.re_nsub;
    infoPtr->matches = (Tcl_RegExpIndices *) regexpPtr->matches;
    infoPtr->extendStart = regexpPtr->details.rm_extend.rm_so;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_GetRegExpFromObj --
 *
 *	Compile a regular expression into a form suitable for fast matching.
 *	This function caches the result in a Tcl_Obj.
 *
 * Results:
 *	The return value is a pointer to the compiled form of string, suitable
 *	for passing to Tcl_RegExpExec. If an error occurred while compiling
 *	the pattern, then NULL is returned and an error message is left in the
 *	interp's result.
 *
 * Side effects:
 *	Updates the native rep of the Tcl_Obj.
 *
 *----------------------------------------------------------------------
 */

Tcl_RegExp
Tcl_GetRegExpFromObj(
    Tcl_Interp *interp,		/* For use in error reporting, and to access
				 * the interp regexp cache. */
    Tcl_Obj *objPtr,		/* Object whose string rep contains regular
				 * expression pattern. Internal rep will be
				 * changed to compiled form of this regular
				 * expression. */
    int flags)			/* Regular expression compilation flags. */
{
    int length;
    TclRegexp *regexpPtr;
    const char *pattern;

    /*
     * This is OK because we only actually interpret this value properly as a
     * TclRegexp* when the type is tclRegexpType.
     */

    regexpPtr = objPtr->internalRep.twoPtrValue.ptr1;

    if ((objPtr->typePtr != &tclRegexpType) || (regexpPtr->flags != flags)) {
	pattern = TclGetStringFromObj(objPtr, &length);

	regexpPtr = CompileRegexp(interp, pattern, length, flags);
	if (regexpPtr == NULL) {
	    return NULL;
	}

	/*
	 * Add a reference to the regexp so it will persist even if it is
	 * pushed out of the current thread's regexp cache. This reference
	 * will be removed when the object's internal rep is freed.
	 */

	regexpPtr->refCount++;

	/*
	 * Free the old representation and set our type.
	 */

	TclFreeIntRep(objPtr);
	objPtr->internalRep.twoPtrValue.ptr1 = regexpPtr;
	objPtr->typePtr = &tclRegexpType;
    }
    return (Tcl_RegExp) regexpPtr;
}

/*
 *----------------------------------------------------------------------
 *
 * TclRegAbout --
 *
 *	Return information about a compiled regular expression.
 *
 * Results:
 *	The return value is -1 for failure, 0 for success, although at the
 *	moment there's nothing that could fail. On success, a list is left in
 *	the interp's result: first element is the subexpression count, second
 *	is a list of re_info bit names.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

int
TclRegAbout(
    Tcl_Interp *interp,		/* For use in variable assignment. */
    Tcl_RegExp re)		/* The compiled regular expression. */
{
    TclRegexp *regexpPtr = (TclRegexp *) re;
    struct infoname {
	int bit;
	const char *text;
    };
    static const struct infoname infonames[] = {
	{REG_UBACKREF,		"REG_UBACKREF"},
	{REG_ULOOKAHEAD,	"REG_ULOOKAHEAD"},
	{REG_UBOUNDS,		"REG_UBOUNDS"},
	{REG_UBRACES,		"REG_UBRACES"},
	{REG_UBSALNUM,		"REG_UBSALNUM"},
	{REG_UPBOTCH,		"REG_UPBOTCH"},
	{REG_UBBS,		"REG_UBBS"},
	{REG_UNONPOSIX,		"REG_UNONPOSIX"},
	{REG_UUNSPEC,		"REG_UUNSPEC"},
	{REG_UUNPORT,		"REG_UUNPORT"},
	{REG_ULOCALE,		"REG_ULOCALE"},
	{REG_UEMPTYMATCH,	"REG_UEMPTYMATCH"},
	{REG_UIMPOSSIBLE,	"REG_UIMPOSSIBLE"},
	{REG_USHORTEST,		"REG_USHORTEST"},
	{0,			NULL}
    };
    const struct infoname *inf;
    Tcl_Obj *infoObj, *resultObj;

    /*
     * The reset here guarantees that the interpreter result is empty and
     * unshared. This means that we can use Tcl_ListObjAppendElement on the
     * result object quite safely.
     */

    Tcl_ResetResult(interp);

    /*
     * Assume that there will never be more than INT_MAX subexpressions. This
     * is a pretty reasonable assumption; the RE engine doesn't scale _that_
     * well and Tcl has other limits that constrain things as well...
     */

    resultObj = Tcl_NewObj();
    Tcl_ListObjAppendElement(NULL, resultObj,
682
	    Tcl_NewWideIntObj((Tcl_WideInt) regexpPtr->re.re_nsub));
683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081

    /*
     * Now append a list of all the bit-flags set for the RE.
     */

    TclNewObj(infoObj);
    for (inf=infonames ; inf->bit != 0 ; inf++) {
	if (regexpPtr->re.re_info & inf->bit) {
	    Tcl_ListObjAppendElement(NULL, infoObj,
		    Tcl_NewStringObj(inf->text, -1));
	}
    }
    Tcl_ListObjAppendElement(NULL, resultObj, infoObj);
    Tcl_SetObjResult(interp, resultObj);

    return 0;
}

/*
 *----------------------------------------------------------------------
 *
 * TclRegError --
 *
 *	Generate an error message based on the regexp status code.
 *
 * Results:
 *	Places an error in the interpreter.
 *
 * Side effects:
 *	Sets errorCode as well.
 *
 *----------------------------------------------------------------------
 */

void
TclRegError(
    Tcl_Interp *interp,		/* Interpreter for error reporting. */
    const char *msg,		/* Message to prepend to error. */
    int status)			/* Status code to report. */
{
    char buf[100];		/* ample in practice */
    char cbuf[TCL_INTEGER_SPACE];
    size_t n;
    const char *p;

    Tcl_ResetResult(interp);
    n = TclReError(status, NULL, buf, sizeof(buf));
    p = (n > sizeof(buf)) ? "..." : "";
    Tcl_SetObjResult(interp, Tcl_ObjPrintf("%s%s%s", msg, buf, p));

    sprintf(cbuf, "%d", status);
    (void) TclReError(REG_ITOA, NULL, cbuf, sizeof(cbuf));
    Tcl_SetErrorCode(interp, "REGEXP", cbuf, buf, NULL);
}

/*
 *----------------------------------------------------------------------
 *
 * FreeRegexpInternalRep --
 *
 *	Deallocate the storage associated with a regexp object's internal
 *	representation.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Frees the compiled regular expression.
 *
 *----------------------------------------------------------------------
 */

static void
FreeRegexpInternalRep(
    Tcl_Obj *objPtr)		/* Regexp object with internal rep to free. */
{
    TclRegexp *regexpRepPtr = objPtr->internalRep.twoPtrValue.ptr1;

    /*
     * If this is the last reference to the regexp, free it.
     */

    if (regexpRepPtr->refCount-- <= 1) {
	FreeRegexp(regexpRepPtr);
    }
    objPtr->typePtr = NULL;
}

/*
 *----------------------------------------------------------------------
 *
 * DupRegexpInternalRep --
 *
 *	We copy the reference to the compiled regexp and bump its reference
 *	count.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Increments the reference count of the regexp.
 *
 *----------------------------------------------------------------------
 */

static void
DupRegexpInternalRep(
    Tcl_Obj *srcPtr,		/* Object with internal rep to copy. */
    Tcl_Obj *copyPtr)		/* Object with internal rep to set. */
{
    TclRegexp *regexpPtr = srcPtr->internalRep.twoPtrValue.ptr1;

    regexpPtr->refCount++;
    copyPtr->internalRep.twoPtrValue.ptr1 = srcPtr->internalRep.twoPtrValue.ptr1;
    copyPtr->typePtr = &tclRegexpType;
}

/*
 *----------------------------------------------------------------------
 *
 * SetRegexpFromAny --
 *
 *	Attempt to generate a compiled regular expression for the Tcl object
 *	"objPtr".
 *
 * Results:
 *	The return value is TCL_OK or TCL_ERROR. If an error occurs during
 *	conversion, an error message is left in the interpreter's result
 *	unless "interp" is NULL.
 *
 * Side effects:
 *	If no error occurs, a regular expression is stored as "objPtr"s
 *	internal representation.
 *
 *----------------------------------------------------------------------
 */

static int
SetRegexpFromAny(
    Tcl_Interp *interp,		/* Used for error reporting if not NULL. */
    Tcl_Obj *objPtr)		/* The object to convert. */
{
    if (Tcl_GetRegExpFromObj(interp, objPtr, REG_ADVANCED) == NULL) {
	return TCL_ERROR;
    }
    return TCL_OK;
}

/*
 *---------------------------------------------------------------------------
 *
 * CompileRegexp --
 *
 *	Attempt to compile the given regexp pattern. If the compiled regular
 *	expression can be found in the per-thread cache, it will be used
 *	instead of compiling a new copy.
 *
 * Results:
 *	The return value is a pointer to a newly allocated TclRegexp that
 *	represents the compiled pattern, or NULL if the pattern could not be
 *	compiled. If NULL is returned, an error message is left in the
 *	interp's result.
 *
 * Side effects:
 *	The thread-local regexp cache is updated and a new TclRegexp may be
 *	allocated.
 *
 *----------------------------------------------------------------------
 */

static TclRegexp *
CompileRegexp(
    Tcl_Interp *interp,		/* Used for error reporting if not NULL. */
    const char *string,		/* The regexp to compile (UTF-8). */
    int length,			/* The length of the string in bytes. */
    int flags)			/* Compilation flags. */
{
    TclRegexp *regexpPtr;
    const Tcl_UniChar *uniString;
    int numChars, status, i, exact;
    Tcl_DString stringBuf;
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);

    if (!tsdPtr->initialized) {
	tsdPtr->initialized = 1;
	Tcl_CreateThreadExitHandler(FinalizeRegexp, NULL);
    }

    /*
     * This routine maintains a second-level regular expression cache in
     * addition to the per-object regexp cache. The per-thread cache is needed
     * to handle the case where for various reasons the object is lost between
     * invocations of the regexp command, but the literal pattern is the same.
     */

    /*
     * Check the per-thread compiled regexp cache. We can only reuse a regexp
     * if it has the same pattern and the same flags.
     */

    for (i = 0; (i < NUM_REGEXPS) && (tsdPtr->patterns[i] != NULL); i++) {
	if ((length == tsdPtr->patLengths[i])
		&& (tsdPtr->regexps[i]->flags == flags)
		&& (strcmp(string, tsdPtr->patterns[i]) == 0)) {
	    /*
	     * Move the matched pattern to the first slot in the cache and
	     * shift the other patterns down one position.
	     */

	    if (i != 0) {
		int j;
		char *cachedString;

		cachedString = tsdPtr->patterns[i];
		regexpPtr = tsdPtr->regexps[i];
		for (j = i-1; j >= 0; j--) {
		    tsdPtr->patterns[j+1] = tsdPtr->patterns[j];
		    tsdPtr->patLengths[j+1] = tsdPtr->patLengths[j];
		    tsdPtr->regexps[j+1] = tsdPtr->regexps[j];
		}
		tsdPtr->patterns[0] = cachedString;
		tsdPtr->patLengths[0] = length;
		tsdPtr->regexps[0] = regexpPtr;
	    }
	    return tsdPtr->regexps[0];
	}
    }

    /*
     * This is a new expression, so compile it and add it to the cache.
     */

    regexpPtr = ckalloc(sizeof(TclRegexp));
    regexpPtr->objPtr = NULL;
    regexpPtr->string = NULL;
    regexpPtr->details.rm_extend.rm_so = -1;
    regexpPtr->details.rm_extend.rm_eo = -1;

    /*
     * Get the up-to-date string representation and map to unicode.
     */

    Tcl_DStringInit(&stringBuf);
    uniString = Tcl_UtfToUniCharDString(string, length, &stringBuf);
    numChars = Tcl_DStringLength(&stringBuf) / sizeof(Tcl_UniChar);

    /*
     * Compile the string and check for errors.
     */

    regexpPtr->flags = flags;
    status = TclReComp(&regexpPtr->re, uniString, (size_t) numChars, flags);
    Tcl_DStringFree(&stringBuf);

    if (status != REG_OKAY) {
	/*
	 * Clean up and report errors in the interpreter, if possible.
	 */

	ckfree(regexpPtr);
	if (interp) {
	    TclRegError(interp,
		    "couldn't compile regular expression pattern: ", status);
	}
	return NULL;
    }

    /*
     * Convert RE to a glob pattern equivalent, if any, and cache it.  If this
     * is not possible, then globObjPtr will be NULL.  This is used by
     * Tcl_RegExpExecObj to optionally do a fast match (avoids RE engine).
     */

    if (TclReToGlob(NULL, string, length, &stringBuf, &exact,
	    NULL) == TCL_OK) {
	regexpPtr->globObjPtr = TclDStringToObj(&stringBuf);
	Tcl_IncrRefCount(regexpPtr->globObjPtr);
    } else {
	regexpPtr->globObjPtr = NULL;
    }

    /*
     * Allocate enough space for all of the subexpressions, plus one extra for
     * the entire pattern.
     */

    regexpPtr->matches =
	    ckalloc(sizeof(regmatch_t) * (regexpPtr->re.re_nsub + 1));

    /*
     * Initialize the refcount to one initially, since it is in the cache.
     */

    regexpPtr->refCount = 1;

    /*
     * Free the last regexp, if necessary, and make room at the head of the
     * list for the new regexp.
     */

    if (tsdPtr->patterns[NUM_REGEXPS-1] != NULL) {
	TclRegexp *oldRegexpPtr = tsdPtr->regexps[NUM_REGEXPS-1];

	if (oldRegexpPtr->refCount-- <= 1) {
	    FreeRegexp(oldRegexpPtr);
	}
	ckfree(tsdPtr->patterns[NUM_REGEXPS-1]);
    }
    for (i = NUM_REGEXPS - 2; i >= 0; i--) {
	tsdPtr->patterns[i+1] = tsdPtr->patterns[i];
	tsdPtr->patLengths[i+1] = tsdPtr->patLengths[i];
	tsdPtr->regexps[i+1] = tsdPtr->regexps[i];
    }
    tsdPtr->patterns[0] = ckalloc(length + 1);
    memcpy(tsdPtr->patterns[0], string, (unsigned) length + 1);
    tsdPtr->patLengths[0] = length;
    tsdPtr->regexps[0] = regexpPtr;

    return regexpPtr;
}

/*
 *----------------------------------------------------------------------
 *
 * FreeRegexp --
 *
 *	Release the storage associated with a TclRegexp.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static void
FreeRegexp(
    TclRegexp *regexpPtr)	/* Compiled regular expression to free. */
{
    TclReFree(&regexpPtr->re);
    if (regexpPtr->globObjPtr) {
	TclDecrRefCount(regexpPtr->globObjPtr);
    }
    if (regexpPtr->matches) {
	ckfree(regexpPtr->matches);
    }
    ckfree(regexpPtr);
}

/*
 *----------------------------------------------------------------------
 *
 * FinalizeRegexp --
 *
 *	Release the storage associated with the per-thread regexp cache.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static void
FinalizeRegexp(
    ClientData clientData)	/* Not used. */
{
    int i;
    TclRegexp *regexpPtr;
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);

    for (i = 0; (i < NUM_REGEXPS) && (tsdPtr->patterns[i] != NULL); i++) {
	regexpPtr = tsdPtr->regexps[i];
	if (regexpPtr->refCount-- <= 1) {
	    FreeRegexp(regexpPtr);
	}
	ckfree(tsdPtr->patterns[i]);
	tsdPtr->patterns[i] = NULL;
    }

    /*
     * We may find ourselves reinitialized if another finalization routine
     * invokes regexps.
     */

    tsdPtr->initialized = 0;
}

/*
 * Local Variables:
 * mode: c
 * c-basic-offset: 4
 * fill-column: 78
 * End:
 */