xmlconfig.c

Mesa is an open-source implementation of the OpenGL specification - a system for rendering interacti

/*
 * 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 "glheader.h"

#include <string.h>
#include <assert.h>
#include <expat.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include "imports.h"
#include "dri_util.h"
#include "xmlconfig.h"

/*
 * OS dependent ways of getting the name of the running program
 */
#if (defined(__unix__) || defined(unix)) && !defined(USG)
#include <sys/param.h>
#endif

#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 <osreldate.h>
#    if (__FreeBSD_version >= 440000)
#        include <stdlib.h>
#        define GET_PROGRAM_NAME() getprogname()
#    endif
#elif defined(__NetBSD__) && defined(__NetBSD_Version) && (__NetBSD_Version >= 106000100)
#    include <stdlib.h>
#    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 <stdlib.h>
#    include <libgen.h>
#    define GET_PROGRAM_NAME() basename(getexecname())
#endif

#if !defined(GET_PROGRAM_NAME)
#    if defined(OpenBSD) || defined(NetBSD) || defined(__UCLIBC__)
/* 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 occor at most once. Optionally the number may end in
 * [eE]<exponent>, where <exponent> 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__);