3 files changed, 155 insertions, 5 deletions

diff --git a/mesalib/src/mesa/drivers/dri/common/dri_util.c b/mesalib/src/mesa/drivers/dri/common/dri_util.c
index 0bce77ea9..d64821112 100644
--- a/mesalib/src/mesa/drivers/dri/common/dri_util.c
+++ b/mesalib/src/mesa/drivers/dri/common/dri_util.c
@@ -438,16 +438,19 @@ driCreateContextAttribs(__DRIscreen *screen, int api,
         return NULL;
     }
 
-    struct gl_context *ctx = context->driverPrivate;
+    *error = __DRI_CTX_ERROR_SUCCESS;
+    return context;
+}
+
+void
+driContextSetFlags(struct gl_context *ctx, uint32_t flags)
+{
     if ((flags & __DRI_CTX_FLAG_FORWARD_COMPATIBLE) != 0)
         ctx->Const.ContextFlags |= GL_CONTEXT_FLAG_FORWARD_COMPATIBLE_BIT;
     if ((flags & __DRI_CTX_FLAG_DEBUG) != 0) {
         ctx->Const.ContextFlags |= GL_CONTEXT_FLAG_DEBUG_BIT;
         ctx->Debug.DebugOutput = GL_TRUE;
     }
-
-    *error = __DRI_CTX_ERROR_SUCCESS;
-    return context;
 }
 
 static __DRIcontext *
@@ -873,3 +876,18 @@ const __DRIimageDriverExtension driImageDriverExtension = {
     .getAPIMask                 = driGetAPIMask,
     .createContextAttribs       = driCreateContextAttribs,
 };
+
+/* swrast copy sub buffer entrypoint. */
+static void driCopySubBuffer(__DRIdrawable *pdp, int x, int y,
+                             int w, int h)
+{
+    assert(pdp->driScreenPriv->swrast_loader);
+
+    pdp->driScreenPriv->driver->CopySubBuffer(pdp, x, y, w, h);
+}
+
+/* for swrast only */
+const __DRIcopySubBufferExtension driCopySubBufferExtension = {
+   { __DRI_COPY_SUB_BUFFER, 1 },
+   .copySubBuffer = driCopySubBuffer,
+};
diff --git a/mesalib/src/mesa/drivers/dri/common/dri_util.h b/mesalib/src/mesa/drivers/dri/common/dri_util.h
index 79a8564ad..a79a4ed7a 100644
--- a/mesalib/src/mesa/drivers/dri/common/dri_util.h
+++ b/mesalib/src/mesa/drivers/dri/common/dri_util.h
@@ -66,7 +66,7 @@ extern const __DRIcoreExtension driCoreExtension;
 extern const __DRIswrastExtension driSWRastExtension;
 extern const __DRIdri2Extension driDRI2Extension;
 extern const __DRI2configQueryExtension dri2ConfigQueryExtension;
-
+extern const __DRIcopySubBufferExtension driCopySubBufferExtension;
 /**
  * Driver callback functions.
  *
@@ -115,6 +115,9 @@ struct __DriverAPIRec {
                                     int width, int height);
 
     void (*ReleaseBuffer) (__DRIscreen *screenPrivate, __DRIbuffer *buffer);
+
+    void (*CopySubBuffer)(__DRIdrawable *driDrawPriv, int x, int y,
+                          int w, int h);
 };
 
 extern const struct __DriverAPIRec driDriverAPI;
@@ -289,6 +292,9 @@ dri2InvalidateDrawable(__DRIdrawable *drawable);
 extern void
 driUpdateFramebufferSize(struct gl_context *ctx, const __DRIdrawable *dPriv);
 
+extern void
+driContextSetFlags(struct gl_context *ctx, uint32_t flags);
+
 extern const __DRIimageDriverExtension driImageDriverExtension;
 
 #endif /* _DRI_UTIL_H_ */
diff --git a/mesalib/src/mesa/drivers/dri/common/megadriver_stub.c b/mesalib/src/mesa/drivers/dri/common/megadriver_stub.c
index 6bf5d7327..a8217703d 100644
--- a/mesalib/src/mesa/drivers/dri/common/megadriver_stub.c
+++ b/mesalib/src/mesa/drivers/dri/common/megadriver_stub.c
@@ -23,6 +23,132 @@
 
 #include <stdio.h>
 #include "dri_util.h"
+#include <dlfcn.h>
+#include "main/macros.h"
+
+/* We need GNU extensions to dlfcn.h in order to provide backward
+ * compatibility for the older DRI driver loader mechanism. (dladdr,
+ * Dl_info, and RTLD_DEFAULT are only defined when _GNU_SOURCE is
+ * defined.)
+ */
+#ifdef _GNU_SOURCE
+
+#define MEGADRIVER_STUB_MAX_EXTENSIONS 10
+#define LIB_PATH_SUFFIX "_dri.so"
+#define LIB_PATH_SUFFIX_LENGTH (sizeof(LIB_PATH_SUFFIX)-1)
+
+/* This is the table of extensions that the loader will dlsym() for.
+ *
+ * Initially it is empty for the megadriver stub, but the library
+ * constructor may initialize it based on the name of the library that
+ * is being loaded.
+ */
+PUBLIC const __DRIextension *
+__driDriverExtensions[MEGADRIVER_STUB_MAX_EXTENSIONS] = {
+   NULL
+};
+
+/**
+ * This is a constructor function for the megadriver dynamic library.
+ *
+ * When the driver is dlopen'ed, this function will run. It will
+ * search for the name of the foo_dri.so file that was opened using
+ * the dladdr function.
+ *
+ * After finding foo's name, it will call __driDriverGetExtensions_foo
+ * and use the return to update __driDriverExtensions to enable
+ * compatibility with older DRI driver loaders.
+ */
+__attribute__((constructor)) static void
+megadriver_stub_init(void)
+{
+   Dl_info info;
+   char *driver_name;
+   size_t name_len;
+   char *get_extensions_name;
+   const __DRIextension **(*get_extensions)(void);
+   const __DRIextension **extensions;
+   int i;
+
+   /* Call dladdr on __driDriverExtensions. We are really
+    * interested in the returned info.dli_fname so we can
+    * figure out the path name of the library being loaded.
+    */
+   i = dladdr((void*) __driDriverExtensions, &info);
+   if (i == 0)
+      return;
+
+   /* Search for the last '/' character in the path. */
+   driver_name = strrchr(info.dli_fname, '/');
+   if (driver_name != NULL) {
+      /* Skip '/' character */
+      driver_name++;
+   } else {
+      /* Try using the start of the path */
+      driver_name = (char*) info.dli_fname;
+   }
+
+   /* Make sure the path ends with _dri.so */
+   name_len = strlen(driver_name);
+   i = name_len - LIB_PATH_SUFFIX_LENGTH;
+   if (i < 0 || strcmp(driver_name + i, LIB_PATH_SUFFIX) != 0)
+      return;
+
+   /* Duplicate the string so we can modify it.
+    * So far we've been using info.dli_fname.
+    */
+   driver_name = strdup(driver_name);
+   if (!driver_name)
+      return;
+
+   /* The path ends with _dri.so. Chop this part of the
+    * string off. Then we'll have the driver's final name.
+    */
+   driver_name[i] = '\0';
+
+   i = asprintf(&get_extensions_name, "%s_%s",
+                __DRI_DRIVER_GET_EXTENSIONS, driver_name);
+   free(driver_name);
+   if (i == -1)
+      return;
+
+   /* dlsym to get the driver's get extensions function. We
+    * don't have the dlopen handle, so we have to use
+    * RTLD_DEFAULT. It seems unlikely that the symbol will
+    * be found in another library, but this isn't optimal.
+    */
+   get_extensions = dlsym(RTLD_DEFAULT, get_extensions_name);
+   free(get_extensions_name);
+   if (!get_extensions)
+      return;
+
+   /* Use the newer DRI loader entrypoint to find extensions.
+    * We will then expose these extensions via the older
+    * __driDriverExtensions symbol.
+    */
+   extensions = get_extensions();
+
+   /* Copy the extensions into the __driDriverExtensions array
+    * we declared.
+    */
+   for (i = 0; i < ARRAY_SIZE(__driDriverExtensions); i++) {
+      __driDriverExtensions[i] = extensions[i];
+      if (extensions[i] == NULL)
+         break;
+   }
+
+   /* If the driver had more extensions than we reserved, then
+    * bail out.
+    */
+   if (i == ARRAY_SIZE(__driDriverExtensions)) {
+      __driDriverExtensions[0] = NULL;
+      fprintf(stderr, "Megadriver stub did not reserve enough extension "
+              "slots.\n");
+      return;
+   }
+}
+
+#endif /* _GNU_SOURCE */
 
 static const
 __DRIconfig **stub_error_init_screen(__DRIscreen *psp)