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/*

 * XML DRI client-side driver configuration

 * Copyright (C) 2003 Felix Kuehling

 *

 * Permission is hereby granted, free of charge, to any person obtaining a

 * copy of this software and associated documentation files (the "Software"),

 * to deal in the Software without restriction, including without limitation

 * the rights to use, copy, modify, merge, publish, distribute, sublicense,

 * and/or sell copies of the Software, and to permit persons to whom the

 * Software is furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included

 * in all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS

 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL

 * FELIX KUEHLING, OR ANY OTHER CONTRIBUTORS BE LIABLE FOR ANY CLAIM,

 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR

 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE

 * OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

 *

 */

/**

 * \file xmlconfig.c

 * \brief Driver-independent client-side part of the XML configuration

 * \author Felix Kuehling

 */

#include "main/glheader.h"

#include 

#include 

#include 

#include 

#include 

#include 

#include "main/imports.h"

#include "utils.h"

#include "xmlconfig.h"

#undef GET_PROGRAM_NAME

#if (defined(__GNU_LIBRARY__) || defined(__GLIBC__)) && !defined(__UCLIBC__)

#    if !defined(__GLIBC__) || (__GLIBC__ < 2)

/* These aren't declared in any libc5 header */

extern char *program_invocation_name, *program_invocation_short_name;

#    endif

#    define GET_PROGRAM_NAME() program_invocation_short_name

#elif defined(__FreeBSD__) && (__FreeBSD__ >= 2)

#    include 

#    if (__FreeBSD_version >= 440000)

#        include 

#        define GET_PROGRAM_NAME() getprogname()

#    endif

#elif defined(__NetBSD__) && defined(__NetBSD_Version) && (__NetBSD_Version >= 106000100)

#    include 

#    define GET_PROGRAM_NAME() getprogname()

#elif defined(__APPLE__)

#    include 

#    define GET_PROGRAM_NAME() getprogname()

#elif defined(__sun)

/* Solaris has getexecname() which returns the full path - return just

   the basename to match BSD getprogname() */

#    include 

#    include 

static const char *__getProgramName () {

    static const char *progname;

    if (progname == NULL) {

	const char *e = getexecname();

	if (e != NULL) {

	    /* Have to make a copy since getexecname can return a readonly

	       string, but basename expects to be able to modify its arg. */

	    char *n = strdup(e);

	    if (n != NULL) {

		progname = basename(n);

	    }

	}

    }

    return progname;

}

#    define GET_PROGRAM_NAME() __getProgramName()

#endif

#if !defined(GET_PROGRAM_NAME)

#    if defined(__OpenBSD__) || defined(NetBSD) || defined(__UCLIBC__) || defined(ANDROID)

/* This is a hack. It's said to work on OpenBSD, NetBSD and GNU.

 * Rogelio M.Serrano Jr. reported it's also working with UCLIBC. It's

 * used as a last resort, if there is no documented facility available. */

static const char *__getProgramName () {

    extern const char *__progname;

    char * arg = strrchr(__progname, '/');

    if (arg)

        return arg+1;

    else

        return __progname;

}

#        define GET_PROGRAM_NAME() __getProgramName()

#    else

#        define GET_PROGRAM_NAME() ""

#        warning "Per application configuration won't work with your OS version."

#    endif

#endif

/** \brief Find an option in an option cache with the name as key */

static GLuint findOption (const driOptionCache *cache, const char *name) {

    GLuint len = strlen (name);

    GLuint size = 1 << cache->tableSize, mask = size - 1;

    GLuint hash = 0;

    GLuint i, shift;

  /* compute a hash from the variable length name */

    for (i = 0, shift = 0; i < len; ++i, shift = (shift+8) & 31)

	hash += (GLuint)name[i] << shift;

    hash *= hash;

    hash = (hash >> (16-cache->tableSize/2)) & mask;

  /* this is just the starting point of the linear search for the option */

    for (i = 0; i < size; ++i, hash = (hash+1) & mask) {

      /* if we hit an empty entry then the option is not defined (yet) */

	if (cache->info[hash].name == 0)

	    break;

	else if (!strcmp (name, cache->info[hash].name))

	    break;

    }

  /* this assertion fails if the hash table is full */

    assert (i < size);

    return hash;

}

/** \brief Count the real number of options in an option cache */

static GLuint countOptions (const driOptionCache *cache) {

    GLuint size = 1 << cache->tableSize;

    GLuint i, count = 0;

    for (i = 0; i < size; ++i)

	if (cache->info[i].name)

	    count++;

    return count;

}

/** \brief Like strdup but using malloc and with error checking. */

#define XSTRDUP(dest,source) do { \

    GLuint len = strlen (source); \

    if (!(dest = malloc(len+1))) { \

	fprintf (stderr, "%s: %d: out of memory.\n", __FILE__, __LINE__); \

	abort(); \

    } \

    memcpy (dest, source, len+1); \

} while (0)

static int compare (const void *a, const void *b) {

    return strcmp (*(char *const*)a, *(char *const*)b);

}

/** \brief Binary search in a string array. */

static GLuint bsearchStr (const XML_Char *name,

			  const XML_Char *elems[], GLuint count) {

    const XML_Char **found;

    found = bsearch (&name, elems, count, sizeof (XML_Char *), compare);

    if (found)

	return found - elems;

    else

	return count;

}

/** \brief Locale-independent integer parser.

 *

 * Works similar to strtol. Leading space is NOT skipped. The input

 * number may have an optional sign. Radix is specified by base. If

 * base is 0 then decimal is assumed unless the input number is

 * prefixed by 0x or 0X for hexadecimal or 0 for octal. After

 * returning tail points to the first character that is not part of

 * the integer number. If no number was found then tail points to the

 * start of the input string. */

static GLint strToI (const XML_Char *string, const XML_Char **tail, int base) {

    GLint radix = base == 0 ? 10 : base;

    GLint result = 0;

    GLint sign = 1;

    GLboolean numberFound = GL_FALSE;

    const XML_Char *start = string;

    assert (radix >= 2 && radix <= 36);

    if (*string == '-') {

	sign = -1;

	string++;

    } else if (*string == '+')

	string++;

    if (base == 0 && *string == '0') {

	numberFound = GL_TRUE;

	if (*(string+1) == 'x' || *(string+1) == 'X') {

	    radix = 16;

	    string += 2;

	} else {

	    radix = 8;

	    string++;

	}

    }

    do {

	GLint digit = -1;

	if (radix <= 10) {

	    if (*string >= '0' && *string < '0' + radix)

		digit = *string - '0';

	} else {

	    if (*string >= '0' && *string <= '9')

		digit = *string - '0';

	    else if (*string >= 'a' && *string < 'a' + radix - 10)

		digit = *string - 'a' + 10;

	    else if (*string >= 'A' && *string < 'A' + radix - 10)

		digit = *string - 'A' + 10;

	}

	if (digit != -1) {

	    numberFound = GL_TRUE;

	    result = radix*result + digit;

	    string++;

	} else

	    break;

    } while (GL_TRUE);

    *tail = numberFound ? string : start;

    return sign * result;

}

/** \brief Locale-independent floating-point parser.

 *

 * Works similar to strtod. Leading space is NOT skipped. The input

 * number may have an optional sign. '.' is interpreted as decimal

 * point and may occur at most once. Optionally the number may end in

 * [eE], where  is an integer as recognized by

 * strToI. In that case the result is number * 10^exponent. After

 * returning tail points to the first character that is not part of

 * the floating point number. If no number was found then tail points

 * to the start of the input string.

 *

 * Uses two passes for maximum accuracy. */

static GLfloat strToF (const XML_Char *string, const XML_Char **tail) {

    GLint nDigits = 0, pointPos, exponent;

    GLfloat sign = 1.0f, result = 0.0f, scale;

    const XML_Char *start = string, *numStart;

    /* sign */

    if (*string == '-') {

	sign = -1.0f;

	string++;

    } else if (*string == '+')

	string++;

    /* first pass: determine position of decimal point, number of

     * digits, exponent and the end of the number. */

    numStart = string;

    while (*string >= '0' && *string <= '9') {

	string++;

	nDigits++;

    }

    pointPos = nDigits;

    if (*string == '.') {

	string++;

	while (*string >= '0' && *string <= '9') {

	    string++;

	    nDigits++;

	}

    }

    if (nDigits == 0) {

	/* no digits, no number */

	*tail = start;

	return 0.0f;

    }

    *tail = string;

    if (*string == 'e' || *string == 'E') {

	const XML_Char *expTail;

	exponent = strToI (string+1, &expTail, 10);

	if (expTail == string+1)

	    exponent = 0;

	else

	    *tail = expTail;

    } else

	exponent = 0;

    string = numStart;

    /* scale of the first digit */

    scale = sign * (GLfloat)pow (10.0, (GLdouble)(pointPos-1 + exponent));

    /* second pass: parse digits */

    do {

	if (*string != '.') {

	    assert (*string >= '0' && *string <= '9');

	    result += scale * (GLfloat)(*string - '0');

	    scale *= 0.1f;

	    nDigits--;

	}

	string++;

    } while (nDigits > 0);

    return result;

}

/** \brief Parse a value of a given type. */

static GLboolean parseValue (driOptionValue *v, driOptionType type,

			     const XML_Char *string) {

    const XML_Char *tail = NULL;

  /* skip leading white-space */

    string += strspn (string, " \f\n\r\t\v");

    switch (type) {

      case DRI_BOOL:

	if (!strcmp (string, "false")) {

	    v->_bool = GL_FALSE;

	    tail = string + 5;

	} else if (!strcmp (string, "true")) {

	    v->_bool = GL_TRUE;

	    tail = string + 4;

	}

	else

	    return GL_FALSE;

	break;

      case DRI_ENUM: /* enum is just a special integer */

      case DRI_INT:

	v->_int = strToI (string, &tail, 0);

	break;

      case DRI_FLOAT:

	v->_float = strToF (string, &tail);

	break;

    }

    if (tail == string)

	return GL_FALSE; /* empty string (or containing only white-space) */

  /* skip trailing white space */

    if (*tail)

	tail += strspn (tail, " \f\n\r\t\v");

    if (*tail)

	return GL_FALSE; /* something left over that is not part of value */

    return GL_TRUE;

}

/** \brief Parse a list of ranges of type info->type. */

static GLboolean parseRanges (driOptionInfo *info, const XML_Char *string) {

    XML_Char *cp, *range;

    GLuint nRanges, i;

    driOptionRange *ranges;

    XSTRDUP (cp, string);

  /* pass 1: determine the number of ranges (number of commas + 1) */

    range = cp;

    for (nRanges = 1; *range; ++range)

	if (*range == ',')

	    ++nRanges;

    if ((ranges = malloc(nRanges*sizeof(driOptionRange))) == NULL) {

	fprintf (stderr, "%s: %d: out of memory.\n", __FILE__, __LINE__);

	abort();

    }

  /* pass 2: parse all ranges into preallocated array */

    range = cp;

    for (i = 0; i < nRanges; ++i) {

	XML_Char *end, *sep;

	assert (range);

	end = strchr (range, ',');

	if (end)

	    *end = '\0';

	sep = strchr (range, ':');

	if (sep) { /* non-empty interval */

	    *sep = '\0';

	    if (!parseValue (&ranges[i].start, info->type, range) ||

		!parseValue (&ranges[i].end, info->type, sep+1))

	        break;

	    if (info->type == DRI_INT &&

		ranges[i].start._int > ranges[i].end._int)

		break;

	    if (info->type == DRI_FLOAT &&

		ranges[i].start._float > ranges[i].end._float)

		break;

	} else { /* empty interval */

	    if (!parseValue (&ranges[i].start, info->type, range))

		break;

	    ranges[i].end = ranges[i].start;

	}

	if (end)

	    range = end+1;

	else

	    range = NULL;

    }

    free(cp);

    if (i < nRanges) {

	free(ranges);

	return GL_FALSE;

    } else

	assert (range == NULL);

    info->nRanges = nRanges;

    info->ranges = ranges;

    return GL_TRUE;

}

/** \brief Check if a value is in one of info->ranges. */

static GLboolean checkValue (const driOptionValue *v, const driOptionInfo *info) {

    GLuint i;

    assert (info->type != DRI_BOOL); /* should be caught by the parser */

    if (info->nRanges == 0)

	return GL_TRUE;

    switch (info->type) {

      case DRI_ENUM: /* enum is just a special integer */

      case DRI_INT:

	for (i = 0; i < info->nRanges; ++i)

	    if (v->_int >= info->ranges[i].start._int &&

		v->_int <= info->ranges[i].end._int)

		return GL_TRUE;

	break;

      case DRI_FLOAT:

	for (i = 0; i < info->nRanges; ++i)

	    if (v->_float >= info->ranges[i].start._float &&

		v->_float <= info->ranges[i].end._float)

		return GL_TRUE;

	break;

      default:

	assert (0); /* should never happen */

    }

    return GL_FALSE;

}

/**

 * Print message to \c stderr if the \c LIBGL_DEBUG environment variable

 * is set.

 *

 * Is called from the drivers.

 *

 * \param f \c printf like format string.

 */

static void

__driUtilMessage(const char *f, ...)

{

    va_list args;

    if (getenv("LIBGL_DEBUG")) {

        fprintf(stderr, "libGL: ");

        va_start(args, f);

        vfprintf(stderr, f, args);

        va_end(args);

        fprintf(stderr, "\n");

    }

}

/** \brief Output a warning message. */

#define XML_WARNING1(msg) do {\

    __driUtilMessage ("Warning in %s line %d, column %d: "msg, data->name, \

                      (int) XML_GetCurrentLineNumber(data->parser), \

                      (int) XML_GetCurrentColumnNumber(data->parser)); \

} while (0)

#define XML_WARNING(msg,args...) do { \

    __driUtilMessage ("Warning in %s line %d, column %d: "msg, data->name, \

                      (int) XML_GetCurrentLineNumber(data->parser), \

                      (int) XML_GetCurrentColumnNumber(data->parser), \

                      args); \

} while (0)

/** \brief Output an error message. */

#define XML_ERROR1(msg) do { \

    __driUtilMessage ("Error in %s line %d, column %d: "msg, data->name, \

                      (int) XML_GetCurrentLineNumber(data->parser), \

                      (int) XML_GetCurrentColumnNumber(data->parser)); \

} while (0)

#define XML_ERROR(msg,args...) do { \

    __driUtilMessage ("Error in %s line %d, column %d: "msg, data->name, \

                      (int) XML_GetCurrentLineNumber(data->parser), \

                      (int) XML_GetCurrentColumnNumber(data->parser), \

                      args); \

} while (0)

/** \brief Output a fatal error message and abort. */

#define XML_FATAL1(msg) do { \

    fprintf (stderr, "Fatal error in %s line %d, column %d: "msg"\n", \

             data->name, \

             (int) XML_GetCurrentLineNumber(data->parser),	\

             (int) XML_GetCurrentColumnNumber(data->parser)); \

    abort();\

} while (0)

#define XML_FATAL(msg,args...) do { \

    fprintf (stderr, "Fatal error in %s line %d, column %d: "msg"\n", \

             data->name, \

             (int) XML_GetCurrentLineNumber(data->parser),	\

             (int) XML_GetCurrentColumnNumber(data->parser),		\

             args); \

    abort();\

} while (0)

/** \brief Parser context for __driConfigOptions. */

struct OptInfoData {

    const char *name;

    XML_Parser parser;

    driOptionCache *cache;

    GLboolean inDriInfo;

    GLboolean inSection;

    GLboolean inDesc;

    GLboolean inOption;

    GLboolean inEnum;

    int curOption;

};

/** \brief Elements in __driConfigOptions. */

enum OptInfoElem {

    OI_DESCRIPTION = 0, OI_DRIINFO, OI_ENUM, OI_OPTION, OI_SECTION, OI_COUNT

};

static const XML_Char *OptInfoElems[] = {

    "description", "driinfo", "enum", "option", "section"

};

/** \brief Parse attributes of an enum element.

 *

 * We're not actually interested in the data. Just make sure this is ok

 * for external configuration tools.

 */

static void parseEnumAttr (struct OptInfoData *data, const XML_Char **attr) {

    GLuint i;

    const XML_Char *value = NULL, *text = NULL;

    driOptionValue v;

    GLuint opt = data->curOption;

    for (i = 0; attr[i]; i += 2) {

	if (!strcmp (attr[i], "value")) value = attr[i+1];

	else if (!strcmp (attr[i], "text")) text = attr[i+1];

	else XML_FATAL("illegal enum attribute: %s.", attr[i]);

    }

    if (!value) XML_FATAL1 ("value attribute missing in enum.");

    if (!text) XML_FATAL1 ("text attribute missing in enum.");

     if (!parseValue (&v, data->cache->info[opt].type, value))

	XML_FATAL ("illegal enum value: %s.", value);

    if (!checkValue (&v, &data->cache->info[opt]))

	XML_FATAL ("enum value out of valid range: %s.", value);

}

/** \brief Parse attributes of a description element.

 *

 * We're not actually interested in the data. Just make sure this is ok

 * for external configuration tools.

 */

static void parseDescAttr (struct OptInfoData *data, const XML_Char **attr) {

    GLuint i;

    const XML_Char *lang = NULL, *text = NULL;

    for (i = 0; attr[i]; i += 2) {

	if (!strcmp (attr[i], "lang")) lang = attr[i+1];

	else if (!strcmp (attr[i], "text")) text = attr[i+1];

	else XML_FATAL("illegal description attribute: %s.", attr[i]);

    }

    if (!lang) XML_FATAL1 ("lang attribute missing in description.");

    if (!text) XML_FATAL1 ("text attribute missing in description.");

}

/** \brief Parse attributes of an option element. */

static void parseOptInfoAttr (struct OptInfoData *data, const XML_Char **attr) {

    enum OptAttr {OA_DEFAULT = 0, OA_NAME, OA_TYPE, OA_VALID, OA_COUNT};

    static const XML_Char *optAttr[] = {"default", "name", "type", "valid"};

    const XML_Char *attrVal[OA_COUNT] = {NULL, NULL, NULL, NULL};

    const char *defaultVal;

    driOptionCache *cache = data->cache;

    GLuint opt, i;

    for (i = 0; attr[i]; i += 2) {

	GLuint attrName = bsearchStr (attr[i], optAttr, OA_COUNT);

	if (attrName >= OA_COUNT)

	    XML_FATAL ("illegal option attribute: %s", attr[i]);

	attrVal[attrName] = attr[i+1];

    }

    if (!attrVal[OA_NAME]) XML_FATAL1 ("name attribute missing in option.");

    if (!attrVal[OA_TYPE]) XML_FATAL1 ("type attribute missing in option.");

    if (!attrVal[OA_DEFAULT]) XML_FATAL1 ("default attribute missing in option.");

    opt = findOption (cache, attrVal[OA_NAME]);

    if (cache->info[opt].name)

	XML_FATAL ("option %s redefined.", attrVal[OA_NAME]);

    data->curOption = opt;

    XSTRDUP (cache->info[opt].name, attrVal[OA_NAME]);

    if (!strcmp (attrVal[OA_TYPE], "bool"))

	cache->info[opt].type = DRI_BOOL;

    else if (!strcmp (attrVal[OA_TYPE], "enum"))

	cache->info[opt].type = DRI_ENUM;

    else if (!strcmp (attrVal[OA_TYPE], "int"))

	cache->info[opt].type = DRI_INT;

    else if (!strcmp (attrVal[OA_TYPE], "float"))

	cache->info[opt].type = DRI_FLOAT;

    else

	XML_FATAL ("illegal type in option: %s.", attrVal[OA_TYPE]);

    defaultVal = getenv (cache->info[opt].name);

    if (defaultVal != NULL) {

      /* don't use XML_WARNING, we want the user to see this! */

	fprintf (stderr,

		 "ATTENTION: default value of option %s overridden by environment.\n",

		 cache->info[opt].name);

    } else

	defaultVal = attrVal[OA_DEFAULT];

    if (!parseValue (&cache->values[opt], cache->info[opt].type, defaultVal))

	XML_FATAL ("illegal default value for %s: %s.", cache->info[opt].name, defaultVal);

    if (attrVal[OA_VALID]) {

	if (cache->info[opt].type == DRI_BOOL)

	    XML_FATAL1 ("boolean option with valid attribute.");

	if (!parseRanges (&cache->info[opt], attrVal[OA_VALID]))

	    XML_FATAL ("illegal valid attribute: %s.", attrVal[OA_VALID]);

	if (!checkValue (&cache->values[opt], &cache->info[opt]))

	    XML_FATAL ("default value out of valid range '%s': %s.",

		       attrVal[OA_VALID], defaultVal);

    } else if (cache->info[opt].type == DRI_ENUM) {

	XML_FATAL1 ("valid attribute missing in option (mandatory for enums).");

    } else {

	cache->info[opt].nRanges = 0;

	cache->info[opt].ranges = NULL;

    }

}

/** \brief Handler for start element events. */

static void optInfoStartElem (void *userData, const XML_Char *name,

			      const XML_Char **attr) {

    struct OptInfoData *data = (struct OptInfoData *)userData;

    enum OptInfoElem elem = bsearchStr (name, OptInfoElems, OI_COUNT);

    switch (elem) {

      case OI_DRIINFO:

	if (data->inDriInfo)

	    XML_FATAL1 ("nested  elements.");

	if (attr[0])

	    XML_FATAL1 ("attributes specified on  element.");

	data->inDriInfo = GL_TRUE;

	break;

      case OI_SECTION:

	if (!data->inDriInfo)

	    XML_FATAL1 ("
 must be inside .");

	if (data->inSection)

	    XML_FATAL1 ("nested 
 elements.");

	if (attr[0])

	    XML_FATAL1 ("attributes specified on 
 element.");

	data->inSection = GL_TRUE;

	break;

      case OI_DESCRIPTION:

	if (!data->inSection && !data->inOption)

	    XML_FATAL1 (" must be inside  or 

	if (data->inDesc)

	    XML_FATAL1 ("nested  elements.");

	data->inDesc = GL_TRUE;

	parseDescAttr (data, attr);

	break;

      case OI_OPTION:

	if (!data->inSection)

	    XML_FATAL1 (" must be inside 
.");

	if (data->inDesc)

	    XML_FATAL1 (" nested in  element.");

	if (data->inOption)

	    XML_FATAL1 ("nested  elements.");

	data->inOption = GL_TRUE;

	parseOptInfoAttr (data, attr);

	break;

      case OI_ENUM:

	if (!(data->inOption && data->inDesc))

	    XML_FATAL1 (" must be inside  and .");

	if (data->inEnum)

	    XML_FATAL1 ("nested  elements.");

	data->inEnum = GL_TRUE;

	parseEnumAttr (data, attr);

	break;

      default:

	XML_FATAL ("unknown element: %s.", name);

    }

}

/** \brief Handler for end element events. */

static void optInfoEndElem (void *userData, const XML_Char *name) {

    struct OptInfoData *data = (struct OptInfoData *)userData;

    enum OptInfoElem elem = bsearchStr (name, OptInfoElems, OI_COUNT);

    switch (elem) {

      case OI_DRIINFO:

	data->inDriInfo = GL_FALSE;

	break;

      case OI_SECTION:

	data->inSection = GL_FALSE;

	break;

      case OI_DESCRIPTION:

	data->inDesc = GL_FALSE;

	break;

      case OI_OPTION:

	data->inOption = GL_FALSE;

	break;

      case OI_ENUM:

	data->inEnum = GL_FALSE;

	break;

      default:

	assert (0); /* should have been caught by StartElem */

    }

}

void driParseOptionInfo (driOptionCache *info,

			 const char *configOptions, GLuint nConfigOptions) {

    XML_Parser p;

    int status;

    struct OptInfoData userData;

    struct OptInfoData *data = &userData;

    GLuint realNoptions;

  /* determine hash table size and allocate memory:

   * 3/2 of the number of options, rounded up, so there remains always

   * at least one free entry. This is needed for detecting undefined

   * options in configuration files without getting a hash table overflow.

   * Round this up to a power of two. */

    GLuint minSize = (nConfigOptions*3 + 1) / 2;

    GLuint size, log2size;

    for (size = 1, log2size = 0; size < minSize; size <<= 1, ++log2size);

    info->tableSize = log2size;

    info->info = calloc(size, sizeof (driOptionInfo));

    info->values = calloc(size, sizeof (driOptionValue));

    if (info->info == NULL || info->values == NULL) {

	fprintf (stderr, "%s: %d: out of memory.\n", __FILE__, __LINE__);

	abort();

    }

    p = XML_ParserCreate ("UTF-8"); /* always UTF-8 */

    XML_SetElementHandler (p, optInfoStartElem, optInfoEndElem);

    XML_SetUserData (p, data);

    userData.name = "__driConfigOptions";

    userData.parser = p;

    userData.cache = info;

    userData.inDriInfo = GL_FALSE;

    userData.inSection = GL_FALSE;

    userData.inDesc = GL_FALSE;

    userData.inOption = GL_FALSE;

    userData.inEnum = GL_FALSE;

    userData.curOption = -1;

    status = XML_Parse (p, configOptions, strlen (configOptions), 1);

    if (!status)

	XML_FATAL ("%s.", XML_ErrorString(XML_GetErrorCode(p)));

    XML_ParserFree (p);

  /* Check if the actual number of options matches nConfigOptions.

   * A mismatch is not fatal (a hash table overflow would be) but we

   * want the driver developer's attention anyway. */

    realNoptions = countOptions (info);

    if (realNoptions != nConfigOptions) {

	fprintf (stderr,

		 "Error: nConfigOptions (%u) does not match the actual number of options in\n"

		 "       __driConfigOptions (%u).\n",

		 nConfigOptions, realNoptions);

    }

}

/** \brief Parser context for configuration files. */

struct OptConfData {

    const char *name;

    XML_Parser parser;

    driOptionCache *cache;

    GLint screenNum;

    const char *driverName, *execName;

    GLuint ignoringDevice;

    GLuint ignoringApp;

    GLuint inDriConf;

    GLuint inDevice;

    GLuint inApp;

    GLuint inOption;

};

/** \brief Elements in configuration files. */

enum OptConfElem {

    OC_APPLICATION = 0, OC_DEVICE, OC_DRICONF, OC_OPTION, OC_COUNT

};

static const XML_Char *OptConfElems[] = {

    "application", "device", "driconf", "option"

};

/** \brief Parse attributes of a device element. */

static void parseDeviceAttr (struct OptConfData *data, const XML_Char **attr) {

    GLuint i;

    const XML_Char *driver = NULL, *screen = NULL;

    for (i = 0; attr[i]; i += 2) {

	if (!strcmp (attr[i], "driver")) driver = attr[i+1];

	else if (!strcmp (attr[i], "screen")) screen = attr[i+1];

	else XML_WARNING("unknown device attribute: %s.", attr[i]);

    }

    if (driver && strcmp (driver, data->driverName))

	data->ignoringDevice = data->inDevice;

    else if (screen) {

	driOptionValue screenNum;

	if (!parseValue (&screenNum, DRI_INT, screen))

	    XML_WARNING("illegal screen number: %s.", screen);

	else if (screenNum._int != data->screenNum)

	    data->ignoringDevice = data->inDevice;

    }

}

/** \brief Parse attributes of an application element. */

static void parseAppAttr (struct OptConfData *data, const XML_Char **attr) {

    GLuint i;

    const XML_Char *exec = NULL;

    for (i = 0; attr[i]; i += 2) {

	if (!strcmp (attr[i], "name")) /* not needed here */;

	else if (!strcmp (attr[i], "executable")) exec = attr[i+1];

	else XML_WARNING("unknown application attribute: %s.", attr[i]);

    }

    if (exec && strcmp (exec, data->execName))

	data->ignoringApp = data->inApp;

}

/** \brief Parse attributes of an option element. */

static void parseOptConfAttr (struct OptConfData *data, const XML_Char **attr) {

    GLuint i;

    const XML_Char *name = NULL, *value = NULL;

    for (i = 0; attr[i]; i += 2) {

	if (!strcmp (attr[i], "name")) name = attr[i+1];

	else if (!strcmp (attr[i], "value")) value = attr[i+1];

	else XML_WARNING("unknown option attribute: %s.", attr[i]);

    }

    if (!name) XML_WARNING1 ("name attribute missing in option.");

    if (!value) XML_WARNING1 ("value attribute missing in option.");

    if (name && value) {

	driOptionCache *cache = data->cache;

	GLuint opt = findOption (cache, name);

	if (cache->info[opt].name == NULL)

            /* don't use XML_WARNING, drirc defines options for all drivers,

             * but not all drivers support them */

            return;

	else if (getenv (cache->info[opt].name))

	  /* don't use XML_WARNING, we want the user to see this! */

	    fprintf (stderr, "ATTENTION: option value of option %s ignored.\n",

		     cache->info[opt].name);

	else if (!parseValue (&cache->values[opt], cache->info[opt].type, value))

	    XML_WARNING ("illegal option value: %s.", value);

    }

}

/** \brief Handler for start element events. */

static void optConfStartElem (void *userData, const XML_Char *name,

			      const XML_Char **attr) {

    struct OptConfData *data = (struct OptConfData *)userData;

    enum OptConfElem elem = bsearchStr (name, OptConfElems, OC_COUNT);

    switch (elem) {

      case OC_DRICONF:

	if (data->inDriConf)

	    XML_WARNING1 ("nested  elements.");

	if (attr[0])

	    XML_WARNING1 ("attributes specified on  element.");

	data->inDriConf++;

	break;

      case OC_DEVICE:

	if (!data->inDriConf)

	    XML_WARNING1 (" should be inside .");

	if (data->inDevice)

	    XML_WARNING1 ("nested  elements.");

	data->inDevice++;

	if (!data->ignoringDevice && !data->ignoringApp)

	    parseDeviceAttr (data, attr);

	break;

      case OC_APPLICATION:

	if (!data->inDevice)

	    XML_WARNING1 (" should be inside .");

	if (data->inApp)

	    XML_WARNING1 ("nested  elements.");

	data->inApp++;

	if (!data->ignoringDevice && !data->ignoringApp)

	    parseAppAttr (data, attr);

	break;

      case OC_OPTION:

	if (!data->inApp)

	    XML_WARNING1 (" should be inside .");

	if (data->inOption)

	    XML_WARNING1 ("nested  elements.");

	data->inOption++;

	if (!data->ignoringDevice && !data->ignoringApp)

	    parseOptConfAttr (data, attr);

	break;

      default:

	XML_WARNING ("unknown element: %s.", name);

    }

}

/** \brief Handler for end element events. */

static void optConfEndElem (void *userData, const XML_Char *name) {

    struct OptConfData *data = (struct OptConfData *)userData;

    enum OptConfElem elem = bsearchStr (name, OptConfElems, OC_COUNT);

    switch (elem) {

      case OC_DRICONF:

	data->inDriConf--;

	break;

      case OC_DEVICE:

	if (data->inDevice-- == data->ignoringDevice)

	    data->ignoringDevice = 0;

	break;

      case OC_APPLICATION:

	if (data->inApp-- == data->ignoringApp)

	    data->ignoringApp = 0;

	break;

      case OC_OPTION:

	data->inOption--;

	break;

      default:

	/* unknown element, warning was produced on start tag */;

    }

}

/** \brief Initialize an option cache based on info */

static void initOptionCache (driOptionCache *cache, const driOptionCache *info) {

    cache->info = info->info;

    cache->tableSize = info->tableSize;

    cache->values = malloc((1<tableSize) * sizeof (driOptionValue));

    if (cache->values == NULL) {

	fprintf (stderr, "%s: %d: out of memory.\n", __FILE__, __LINE__);

	abort();

    }

    memcpy (cache->values, info->values,

	    (1<tableSize) * sizeof (driOptionValue));

}

/** \brief Parse the named configuration file */

static void parseOneConfigFile (XML_Parser p) {

#define BUF_SIZE 0x1000

    struct OptConfData *data = (struct OptConfData *)XML_GetUserData (p);

    int status;

    int fd;

    if ((fd = open (data->name, O_RDONLY)) == -1) {

	__driUtilMessage ("Can't open configuration file %s: %s.",

			  data->name, strerror (errno));

	return;

    }

    while (1) {

	int bytesRead;

	void *buffer = XML_GetBuffer (p, BUF_SIZE);

	if (!buffer) {

	    __driUtilMessage ("Can't allocate parser buffer.");

	    break;

	}

	bytesRead = read (fd, buffer, BUF_SIZE);

	if (bytesRead == -1) {

	    __driUtilMessage ("Error reading from configuration file %s: %s.",

			      data->name, strerror (errno));

	    break;

	}

	status = XML_ParseBuffer (p, bytesRead, bytesRead == 0);

	if (!status) {

	    XML_ERROR ("%s.", XML_ErrorString(XML_GetErrorCode(p)));

	    break;

	}

	if (bytesRead == 0)

	    break;

    }

    close (fd);

#undef BUF_SIZE

}

void driParseConfigFiles (driOptionCache *cache, const driOptionCache *info,

			  GLint screenNum, const char *driverName) {

    char *filenames[2] = {"/etc/drirc", NULL};

    char *home;

    GLuint i;

    struct OptConfData userData;

    initOptionCache (cache, info);

    userData.cache = cache;

    userData.screenNum = screenNum;

    userData.driverName = driverName;

    userData.execName = GET_PROGRAM_NAME();

    if ((home = getenv ("HOME"))) {

	GLuint len = strlen (home);

	filenames[1] = malloc(len + 7+1);

	if (filenames[1] == NULL)

	    __driUtilMessage ("Can't allocate memory for %s/.drirc.", home);

	else {

	    memcpy (filenames[1], home, len);

	    memcpy (filenames[1] + len, "/.drirc", 7+1);

	}

    }

    for (i = 0; i < 2; ++i) {

	XML_Parser p;

	if (filenames[i] == NULL)

	    continue;

	p = XML_ParserCreate (NULL); /* use encoding specified by file */

	XML_SetElementHandler (p, optConfStartElem, optConfEndElem);

	XML_SetUserData (p, &userData);

	userData.parser = p;

	userData.name = filenames[i];

	userData.ignoringDevice = 0;

	userData.ignoringApp = 0;

	userData.inDriConf = 0;

	userData.inDevice = 0;

	userData.inApp = 0;

	userData.inOption = 0;

	parseOneConfigFile (p);

	XML_ParserFree (p);

    }

    free(filenames[1]);

}

void driDestroyOptionInfo (driOptionCache *info) {

    driDestroyOptionCache (info);

    if (info->info) {

	GLuint i, size = 1 << info->tableSize;

	for (i = 0; i < size; ++i) {

	    if (info->info[i].name) {

		free(info->info[i].name);

		free(info->info[i].ranges);

	    }

	}

	free(info->info);

    }

}

void driDestroyOptionCache (driOptionCache *cache) {

    free(cache->values);

}

GLboolean driCheckOption (const driOptionCache *cache, const char *name,

			  driOptionType type) {

    GLuint i = findOption (cache, name);

    return cache->info[i].name != NULL && cache->info[i].type == type;

}

GLboolean driQueryOptionb (const driOptionCache *cache, const char *name) {

    GLuint i = findOption (cache, name);

  /* make sure the option is defined and has the correct type */

    assert (cache->info[i].name != NULL);

    assert (cache->info[i].type == DRI_BOOL);

    return cache->values[i]._bool;

}

GLint driQueryOptioni (const driOptionCache *cache, const char *name) {

    GLuint i = findOption (cache, name);

  /* make sure the option is defined and has the correct type */

    assert (cache->info[i].name != NULL);

    assert (cache->info[i].type == DRI_INT || cache->info[i].type == DRI_ENUM);

    return cache->values[i]._int;

}

GLfloat driQueryOptionf (const driOptionCache *cache, const char *name) {

    GLuint i = findOption (cache, name);

  /* make sure the option is defined and has the correct type */

    assert (cache->info[i].name != NULL);

    assert (cache->info[i].type == DRI_FLOAT);

    return cache->values[i]._float;

}