• xf86-video-intel源码分析5 —— intel_options.c和intel_options.h（2）

    接上一篇文章《xf86-video-intel源码分析4 —— intel_options.c和intel_options.h（1）》，链接为：

    xf86-video-intel源码分析4 —— intel_options.c和intel_options.h（1）_蓝天居士的博客-CSDN博客

    本节对intel_options.c中的函数进行分析。

    • intel_options_get

     源码如下：

    1. OptionInfoPtr intel_options_get(ScrnInfoPtr scrn)
    2. {
    3. 	OptionInfoPtr options;
    4.  
    5. 	xf86CollectOptions(scrn, NULL);
    6. 	if (!(options = malloc(sizeof(intel_options))))
    7. 		return NULL;
    8.  
    9. 	memcpy(options, intel_options, sizeof(intel_options));
    10. 	xf86ProcessOptions(scrn->scrnIndex, scrn->options, options);
    11.  
    12. 	return options;
    13. }

    options的类型为OptionInfoPtr，即OptionInfoRec结构的指针。但是注意，这里给它分配的空间不仅仅包含一个实例即数组的一项，而是包含了整个intel_options数组，options指向的是数组intel_options数组拷贝到内存后的内存首地址。

    xf86开头的函数并不在xf86-video-intel源码中，也是在xorf-server代码中。xf86CollectOptions在xorg-server的hw/xfree86/common/xf86Option.c中，源码如下：

    1. /*
    2.  * xf86CollectOptions collects the options from each of the config file
    3.  * sections used by the screen and puts the combined list in pScrn->options.
    4.  * This function requires that the following have been initialised:
    5.  *
    6.  *	pScrn->confScreen
    7.  *	pScrn->Entities[i]->device
    8.  *	pScrn->display
    9.  *	pScrn->monitor
    10.  *
    11.  * The extraOpts parameter may optionally contain a list of additional options
    12.  * to include.
    13.  *
    14.  * The order of precedence for options is:
    15.  *
    16.  *   extraOpts, display, confScreen, monitor, device, outputClassOptions
    17.  */
    18.  
    19. void
    20. xf86CollectOptions(ScrnInfoPtr pScrn, XF86OptionPtr extraOpts)
    21. {
    22.     XF86OptionPtr tmp;
    23.     XF86OptionPtr extras = (XF86OptionPtr) extraOpts;
    24.     GDevPtr device;
    25.  
    26.     int i;
    27.  
    28.     pScrn->options = NULL;
    29.  
    30.     for (i = pScrn->numEntities - 1; i >= 0; i--) {
    31.         xf86MergeOutputClassOptions(pScrn->entityList[i], &pScrn->options);
    32.  
    33.         device = xf86GetDevFromEntity(pScrn->entityList[i],
    34.                                       pScrn->entityInstanceList[i]);
    35.         if (device && device->options) {
    36.             tmp = xf86optionListDup(device->options);
    37.             if (pScrn->options)
    38.                 pScrn->options = xf86optionListMerge(pScrn->options, tmp);
    39.             else
    40.                 pScrn->options = tmp;
    41.         }
    42.     }
    43.     if (pScrn->monitor->options) {
    44.         tmp = xf86optionListDup(pScrn->monitor->options);
    45.         if (pScrn->options)
    46.             pScrn->options = xf86optionListMerge(pScrn->options, tmp);
    47.         else
    48.             pScrn->options = tmp;
    49.     }
    50.     if (pScrn->confScreen->options) {
    51.         tmp = xf86optionListDup(pScrn->confScreen->options);
    52.         if (pScrn->options)
    53.             pScrn->options = xf86optionListMerge(pScrn->options, tmp);
    54.         else
    55.             pScrn->options = tmp;
    56.     }
    57.     if (pScrn->display->options) {
    58.         tmp = xf86optionListDup(pScrn->display->options);
    59.         if (pScrn->options)
    60.             pScrn->options = xf86optionListMerge(pScrn->options, tmp);
    61.         else
    62.             pScrn->options = tmp;
    63.     }
    64.     if (extras) {
    65.         tmp = xf86optionListDup(extras);
    66.         if (pScrn->options)
    67.             pScrn->options = xf86optionListMerge(pScrn->options, tmp);
    68.         else
    69.             pScrn->options = tmp;
    70.     }
    71. }

    根据函数说明，xf86CollectOptions收集屏幕使用的配置文件中每个段的选项，并且将这些选项的组合列表放置到pScrn->options中。
    xf86ProcessOptions函数同样在xorg-server的xf86Option.c中实现，代码如下：

    1. void
    2. xf86ProcessOptions(int scrnIndex, XF86OptionPtr options, OptionInfoPtr optinfo)
    3. {
    4.     OptionInfoPtr p;
    5.  
    6.     for (p = optinfo; p->name != NULL; p++) {
    7.         ParseOptionValue(scrnIndex, options, p, TRUE);
    8.     }
    9. }
    1. static Bool
    2. ParseOptionValue(int scrnIndex, XF86OptionPtr options, OptionInfoPtr p,
    3.                  Bool markUsed)
    4. {
    5.     const char *s;
    6.     char *end;
    7.     Bool wasUsed = FALSE;
    8.  
    9.     if ((s = xf86findOptionValue(options, p->name)) != NULL) {
    10.         if (markUsed) {
    11.             wasUsed = xf86CheckIfOptionUsedByName(options, p->name);
    12.             xf86MarkOptionUsedByName(options, p->name);
    13.         }
    14.         switch (p->type) {
    15.         case OPTV_INTEGER:
    16.             if (*s == '\0') {
    17.                 if (markUsed) {
    18.                     xf86DrvMsg(scrnIndex, X_WARNING,
    19.                                "Option \"%s\" requires an integer value\n",
    20.                                p->name);
    21.                 }
    22.                 p->found = FALSE;
    23.             }
    24.             else {
    25.                 p->value.num = strtoul(s, &end, 0);
    26.                 if (*end == '\0') {
    27.                     p->found = TRUE;
    28.                 }
    29.                 else {
    30.                     if (markUsed) {
    31.                         xf86DrvMsg(scrnIndex, X_WARNING,
    32.                                    "Option \"%s\" requires an integer value\n",
    33.                                    p->name);
    34.                     }
    35.                     p->found = FALSE;
    36.                 }
    37.             }
    38.             break;
    39.         case OPTV_STRING:
    40.             if (*s == '\0') {
    41.                 if (markUsed) {
    42.                     xf86DrvMsg(scrnIndex, X_WARNING,
    43.                                "Option \"%s\" requires a string value\n",
    44.                                p->name);
    45.                 }
    46.                 p->found = FALSE;
    47.             }
    48.             else {
    49.                 p->value.str = s;
    50.                 p->found = TRUE;
    51.             }
    52.             break;
    53.         case OPTV_ANYSTR:
    54.             p->value.str = s;
    55.             p->found = TRUE;
    56.             break;
    57.         case OPTV_REAL:
    58.             if (*s == '\0') {
    59.                 if (markUsed) {
    60.                     xf86DrvMsg(scrnIndex, X_WARNING,
    61.                                "Option \"%s\" requires a floating point "
    62.                                "value\n", p->name);
    63.                 }
    64.                 p->found = FALSE;
    65.             }
    66.             else {
    67.                 p->value.realnum = strtod(s, &end);
    68.                 if (*end == '\0') {
    69.                     p->found = TRUE;
    70.                 }
    71.                 else {
    72.                     if (markUsed) {
    73.                         xf86DrvMsg(scrnIndex, X_WARNING,
    74.                                    "Option \"%s\" requires a floating point "
    75.                                    "value\n", p->name);
    76.                     }
    77.                     p->found = FALSE;
    78.                 }
    79.             }
    80.             break;
    81.         case OPTV_BOOLEAN:
    82.             if (GetBoolValue(p, s)) {
    83.                 p->found = TRUE;
    84.             }
    85.             else {
    86.                 if (markUsed) {
    87.                     xf86DrvMsg(scrnIndex, X_WARNING,
    88.                                "Option \"%s\" requires a boolean value\n",
    89.                                p->name);
    90.                 }
    91.                 p->found = FALSE;
    92.             }
    93.             break;
    94.         case OPTV_PERCENT:
    95.         {
    96.             char tmp = 0;
    97.  
    98.             /* awkward match, but %% doesn't increase the match counter,
    99.              * hence 100 looks the same as 100% to the caller of sccanf
    100.              */
    101.             if (sscanf(s, "%lf%c", &p->value.realnum, &tmp) != 2 || tmp != '%') {
    102.                 if (markUsed) {
    103.                     xf86DrvMsg(scrnIndex, X_WARNING,
    104.                                "Option \"%s\" requires a percent value\n",
    105.                                p->name);
    106.                 }
    107.                 p->found = FALSE;
    108.             }
    109.             else {
    110.                 p->found = TRUE;
    111.             }
    112.         }
    113.             break;
    114.         case OPTV_FREQ:
    115.             if (*s == '\0') {
    116.                 if (markUsed) {
    117.                     xf86DrvMsg(scrnIndex, X_WARNING,
    118.                                "Option \"%s\" requires a frequency value\n",
    119.                                p->name);
    120.                 }
    121.                 p->found = FALSE;
    122.             }
    123.             else {
    124.                 double freq = strtod(s, &end);
    125.                 int units = 0;
    126.  
    127.                 if (end != s) {
    128.                     p->found = TRUE;
    129.                     if (!xf86NameCmp(end, "Hz"))
    130.                         units = 1;
    131.                     else if (!xf86NameCmp(end, "kHz") || !xf86NameCmp(end, "k"))
    132.                         units = 1000;
    133.                     else if (!xf86NameCmp(end, "MHz") || !xf86NameCmp(end, "M"))
    134.                         units = 1000000;
    135.                     else {
    136.                         if (markUsed) {
    137.                             xf86DrvMsg(scrnIndex, X_WARNING,
    138.                                        "Option \"%s\" requires a frequency value\n",
    139.                                        p->name);
    140.                         }
    141.                         p->found = FALSE;
    142.                     }
    143.                     if (p->found)
    144.                         freq *= (double) units;
    145.                 }
    146.                 else {
    147.                     if (markUsed) {
    148.                         xf86DrvMsg(scrnIndex, X_WARNING,
    149.                                    "Option \"%s\" requires a frequency value\n",
    150.                                    p->name);
    151.                     }
    152.                     p->found = FALSE;
    153.                 }
    154.                 if (p->found) {
    155.                     p->value.freq.freq = freq;
    156.                     p->value.freq.units = units;
    157.                 }
    158.             }
    159.             break;
    160.         case OPTV_NONE:
    161.             /* Should never get here */
    162.             p->found = FALSE;
    163.             break;
    164.         }
    165.         if (p->found && markUsed) {
    166.             int verb = 2;
    167.  
    168.             if (wasUsed)
    169.                 verb = 4;
    170.             xf86DrvMsgVerb(scrnIndex, X_CONFIG, verb, "Option \"%s\"", p->name);
    171.             if (!(p->type == OPTV_BOOLEAN && *s == 0)) {
    172.                 xf86ErrorFVerb(verb, " \"%s\"", s);
    173.             }
    174.             xf86ErrorFVerb(verb, "\n");
    175.         }
    176.     }
    177.     else if (p->type == OPTV_BOOLEAN) {
    178.         /* Look for matches with options with or without a "No" prefix. */
    179.         char *n, *newn;
    180.         OptionInfoRec opt;
    181.  
    182.         n = xf86NormalizeName(p->name);
    183.         if (!n) {
    184.             p->found = FALSE;
    185.             return FALSE;
    186.         }
    187.         if (strncmp(n, "no", 2) == 0) {
    188.             newn = n + 2;
    189.         }
    190.         else {
    191.             free(n);
    192.             if (asprintf(&n, "No%s", p->name) == -1) {
    193.                 p->found = FALSE;
    194.                 return FALSE;
    195.             }
    196.             newn = n;
    197.         }
    198.         if ((s = xf86findOptionValue(options, newn)) != NULL) {
    199.             if (markUsed)
    200.                 xf86MarkOptionUsedByName(options, newn);
    201.             if (GetBoolValue(&opt, s)) {
    202.                 p->value.boolean = !opt.value.boolean;
    203.                 p->found = TRUE;
    204.             }
    205.             else {
    206.                 xf86DrvMsg(scrnIndex, X_WARNING,
    207.                            "Option \"%s\" requires a boolean value\n", newn);
    208.                 p->found = FALSE;
    209.             }
    210.         }
    211.         else {
    212.             p->found = FALSE;
    213.         }
    214.         if (p->found && markUsed) {
    215.             xf86DrvMsgVerb(scrnIndex, X_CONFIG, 2, "Option \"%s\"", newn);
    216.             if (*s != 0) {
    217.                 xf86ErrorFVerb(2, " \"%s\"", s);
    218.             }
    219.             xf86ErrorFVerb(2, "\n");
    220.         }
    221.         free(n);
    222.     }
    223.     else {
    224.         p->found = FALSE;
    225.     }
    226.     return p->found;
    227. }
    • intel_option_cast_to_bool
    1. Bool intel_option_cast_to_bool(OptionInfoPtr options, int id, Bool val)
    2. {
    3. #if XORG_VERSION_CURRENT >= XORG_VERSION_NUMERIC(1,7,99,901,0)
    4. 	xf86getBoolValue(&val, xf86GetOptValString(options, id));
    5. #endif
    6. 	return val;
    7. }

    如果xorg-server的版本比1.7.99.901新，则调用xf86getBoolValue函数，将options中的字符串转换为布尔值；否则不做处理，直接返回。

    • namecmp
    1. static int
    2. namecmp(const char *s1, const char *s2)
    3. {
    4. 	char c1, c2;
    5.  
    6. 	if (!s1 || *s1 == 0) {
    7. 		if (!s2 || *s2 == 0)
    8. 			return 0;
    9. 		else
    10. 			return 1;
    11. 	}
    12.  
    13. 	while (*s1 == '_' || *s1 == ' ' || *s1 == '\t')
    14. 		s1++;
    15.  
    16. 	while (*s2 == '_' || *s2 == ' ' || *s2 == '\t')
    17. 		s2++;
    18.  
    19. 	c1 = isupper(*s1) ? tolower(*s1) : *s1;
    20. 	c2 = isupper(*s2) ? tolower(*s2) : *s2;
    21. 	while (c1 == c2) {
    22. 		if (c1 == '\0')
    23. 			return 0;
    24.  
    25. 		s1++;
    26. 		while (*s1 == '_' || *s1 == ' ' || *s1 == '\t')
    27. 			s1++;
    28.  
    29. 		s2++;
    30. 		while (*s2 == '_' || *s2 == ' ' || *s2 == '\t')
    31. 			s2++;
    32.  
    33. 		c1 = isupper(*s1) ? tolower(*s1) : *s1;
    34. 		c2 = isupper(*s2) ? tolower(*s2) : *s2;
    35. 	}
    36.  
    37. 	return c1 - c2;
    38. }

    这个函数顾名思义，进行名称比较，有些类似于strcmp函数。

    • intel_option_cast_to_unsigned
    1. unsigned intel_option_cast_to_unsigned(OptionInfoPtr options, int id, unsigned val)
    2. {
    3. #if XORG_VERSION_CURRENT >= XORG_VERSION_NUMERIC(1,7,99,901,0)
    4. 	const char *str = xf86GetOptValString(options, id);
    5. #else
    6. 	const char *str = NULL;
    7. #endif
    8. 	unsigned v;
    9.  
    10. 	if (str == NULL || *str == '\0')
    11. 		return val;
    12.  
    13. 	if (namecmp(str, "on") == 0)
    14. 		return val;
    15. 	if (namecmp(str, "true") == 0)
    16. 		return val;
    17. 	if (namecmp(str, "yes") == 0)
    18. 		return val;
    19.  
    20. 	if (namecmp(str, "0") == 0)
    21. 		return 0;
    22. 	if (namecmp(str, "off") == 0)
    23. 		return 0;
    24. 	if (namecmp(str, "false") == 0)
    25. 		return 0;
    26. 	if (namecmp(str, "no") == 0)
    27. 		return 0;
    28.  
    29. 	v = atoi(str);
    30. 	if (v)
    31. 		return v;
    32.  
    33. 	return val;
    34. }

    这个函数同样不难理解，调用了上边的namecmp函数。如果入参str中包含了"on"、"true"、"yes"，则返回val；如果str中包含的是"0"、"off"、"false"或者"no"，则直接返回0；如果str中没有这些关键字，则将字符串转换为整数并返回。

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  • 原文地址：https://blog.csdn.net/phmatthaus/article/details/128024334