[Mesa-dev] [PATCH] mesa: load custom drirc only when specified in env variable

[Edmondo Tommasina]

Define a new MESA_CUSTOM_DRIRC environment variable to load
a drirc custom file, instead of blindly using the hardcoded
${HOME}/.drirc file created the driconf tool.

Some more discussion about the driconf issues can be found
in reading following mesa-dev thread:
https://lists.freedesktop.org/archives/mesa-dev/2017-January/139864.html

Users can now specify which custom driconf file they want
to use (for example the ${HOME}/.drirc created with the
tool).

Example:

$ glxgears
Running synchronized to the vertical refresh.  The framerate should be
approximately the same as the monitor refresh rate.
359 frames in 5.0 seconds = 71.579 FPS
300 frames in 5.0 seconds = 60.000 FPS

$ cat noblank.drirc
<driconf>
    <device>
        <application name="Default">
            <option name="vblank_mode" value="0" />
        </application>
    </device>
</driconf>

$ MESA_CUSTOM_DRIRC=/home/edmondo/noblank.drirc glxgears
27332 frames in 5.0 seconds = 5466.378 FPS
29730 frames in 5.0 seconds = 5945.912 FPS
---
 docs/application-issues.html            |  4 ++--
 docs/envvars.html                       |  1 +
 docs/postprocess.html                   |  4 ++--
 src/mesa/drivers/dri/common/xmlconfig.c | 16 +---------------
 4 files changed, 6 insertions(+), 19 deletions(-)

diff --git a/docs/application-issues.html b/docs/application-issues.html
index 6db0865..10e1957 100644
--- a/docs/application-issues.html
+++ b/docs/application-issues.html
@@ -33,8 +33,8 @@ without a depth buffer.
 <p>
 Mesa 9.1.2 and later (will) support a DRI configuration option to work around
 this issue.
-Using the <a href="http://dri.freedesktop.org/wiki/DriConf">driconf</a> tool,
-set the "Create all visuals with a depth buffer" option before running Topogun.
+Set the "always_have_depth_buffer" environment variable before running Topogun
+or use a custom drirc file (MESA_CUSTOM_DRIRC).
 Then, all GLX visuals will be created with a depth buffer.
 </p>
 
diff --git a/docs/envvars.html b/docs/envvars.html
index 9eee8db..e168a38 100644
--- a/docs/envvars.html
+++ b/docs/envvars.html
@@ -116,6 +116,7 @@ glGetString(GL_SHADING_LANGUAGE_VERSION). Valid values are integers, such as
 if it's higher than what's normally reported. (for developers only)
 <li>MESA_GLSL - <a href="shading.html#envvars">shading language compiler options</a>
 <li>MESA_NO_MINMAX_CACHE - when set, the minmax index cache is globally disabled.
+<li>MESA_CUSTOM_DRIRC - load custom drirc file.
 </ul>
 
 
diff --git a/docs/postprocess.html b/docs/postprocess.html
index db4abec..7efa99d 100644
--- a/docs/postprocess.html
+++ b/docs/postprocess.html
@@ -24,8 +24,8 @@ Example filters include morphological antialiasing and cell shading.
 </p>
 
 <p>
-The filters can be toggled per-app via driconf, or per-session via the
-corresponding environment variables.
+The filters can be toggled via corresponding environment variables
+or a custom drirc file (MESA_CUSTOM_DRIRC).
 </p>
 
 <p>
diff --git a/src/mesa/drivers/dri/common/xmlconfig.c b/src/mesa/drivers/dri/common/xmlconfig.c
index a8f7c9b..c36b78a 100644
--- a/src/mesa/drivers/dri/common/xmlconfig.c
+++ b/src/mesa/drivers/dri/common/xmlconfig.c
@@ -944,8 +944,7 @@ static void parseOneConfigFile (XML_Parser p) {
 
 void driParseConfigFiles (driOptionCache *cache, const driOptionCache *info,
 			  int screenNum, const char *driverName) {
-    char *filenames[2] = { SYSCONFDIR "/drirc", NULL};
-    char *home;
+    char *filenames[2] = { SYSCONFDIR "/drirc", getenv("MESA_CUSTOM_DRIRC") };
     uint32_t i;
     struct OptConfData userData;
 
@@ -956,17 +955,6 @@ void driParseConfigFiles (driOptionCache *cache, const driOptionCache *info,
     userData.driverName = driverName;
     userData.execName = GET_PROGRAM_NAME();
 
-    if ((home = getenv ("HOME"))) {
-	uint32_t 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)
@@ -987,8 +975,6 @@ void driParseConfigFiles (driOptionCache *cache, const driOptionCache *info,
 	parseOneConfigFile (p);
 	XML_ParserFree (p);
     }
-
-    free(filenames[1]);
 }
 
 void driDestroyOptionInfo (driOptionCache *info) {
-- 
2.10.0