xmlconfig: read more config files from drirc.d/

Driver and application can put their drirc files in
${datadir}/drirc.d/ with name xxx.conf. Config files
will be read and applied in file name alphabetic order.

So there are three places for drirc listed in order:
1. /usr/share/drirc.d/
2. /etc/drirc
3. ~/.drirc

v4:
  fix meson build

v3:
  1. seperate driParseConfigFiles refine into another patch
  2. fix entries[i] mem leak

v2:
  drop /etc/drirc.d

Signed-off-by: Qiang Yu <Qiang.Yu@amd.com>
Acked-by: Michel Dänzer <michel.daenzer@amd.com>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>

docs/autoconf.html

@@ -94,6 +94,13 @@ Currently there's only one config file provided when dri drivers are
 enabled - it's <code>drirc</code>.</p>
 </dd>
 
+<dt><code>--datadir=DIR</code></dt>
+<dd><p>This option specifies the directory where the data files will
+be installed. The default is <code>${prefix}/share</code>.
+Currently when dri drivers are enabled, <code>drirc.d/</code> is at
+this place.</p>
+</dd>
+
 <dt><code>--enable-static, --disable-shared</code></dt>
 <dd><p>By default, Mesa
 will build shared libraries. Either of these options will force static

src/util/Makefile.am

@@ -67,6 +67,7 @@ libxmlconfig_la_CFLAGS = \
 	-I$(top_srcdir)/include \
 	-I$(top_srcdir)/src \
 	-DSYSCONFDIR=\"$(sysconfdir)\" \
+	-DDATADIR=\"$(datadir)\" \
 	$(VISIBILITY_CFLAGS) \
 	$(EXPAT_CFLAGS)
 libxmlconfig_la_LIBADD = $(EXPAT_LIBS) -lm

src/util/meson.build

@@ -123,6 +123,9 @@ libxmlconfig = static_library(
     '-DSYSCONFDIR="@0@"'.format(
       join_paths(get_option('prefix'), get_option('sysconfdir'))
     ),
+    '-DDATADIR="@0@"'.format(
+      join_paths(get_option('prefix'), get_option('datadir'))
+    ),
   ],
   build_by_default : false,
 )

src/util/xmlconfig.c

@@ -37,6 +37,8 @@
 #include <math.h>
 #include <unistd.h>
 #include <errno.h>
+#include <dirent.h>
+#include <fnmatch.h>
 #include "xmlconfig.h"
 #include "u_process.h"
 
@@ -929,10 +931,49 @@ parseOneConfigFile(struct OptConfData *data, const char *filename)
     XML_ParserFree (p);
 }
 
+static int
+scandir_filter(const struct dirent *ent)
+{
+    if (ent->d_type != DT_REG && ent->d_type != DT_LNK)
+       return 0;
+
+    if (fnmatch("*.conf", ent->d_name, 0))
+       return 0;
+
+    return 1;
+}
+
+/** \brief Parse configuration files in a directory */
+static void
+parseConfigDir(struct OptConfData *data, const char *dirname)
+{
+    int i, count;
+    struct dirent **entries = NULL;
+
+    count = scandir(dirname, &entries, scandir_filter, alphasort);
+    if (count < 0)
+        return;
+
+    for (i = 0; i < count; i++) {
+        char filename[PATH_MAX];
+
+        snprintf(filename, PATH_MAX, "%s/%s", dirname, entries[i]->d_name);
+        free(entries[i]);
+
+        parseOneConfigFile(data, filename);
+    }
+
+    free(entries);
+}
+
 #ifndef SYSCONFDIR
 #define SYSCONFDIR "/etc"
 #endif
 
+#ifndef DATADIR
+#define DATADIR "/usr/share"
+#endif
+
 void
 driParseConfigFiles(driOptionCache *cache, const driOptionCache *info,
                     int screenNum, const char *driverName)
@@ -947,6 +988,7 @@ driParseConfigFiles(driOptionCache *cache, const driOptionCache *info,
     userData.driverName = driverName;
     userData.execName = util_get_process_name();
 
+    parseConfigDir(&userData, DATADIR "/drirc.d");
     parseOneConfigFile(&userData, SYSCONFDIR "/drirc");
 
     if ((home = getenv ("HOME"))) {