+/* Copyright © 2013, Intel Corporation
+ *
+ * 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 THE
+ * AUTHORS OR COPYRIGHT HOLDERS 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.
+ */
+
+#define _GNU_SOURCE
+#include <dlfcn.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+
+void *libgl_handle;
+void *wrapper_handle;
+
+static void
+open_libgl_handle (void)
+{
+ const char *path;
+
+ if (libgl_handle)
+ return;
+
+ path = getenv ("GLAZE_LIBGL");
+ if (path == NULL) {
+ fprintf (stderr, "GLAZE_LIBGL unset. Please set to path of real libGL.so under glaze.\n");
+ exit (1);
+ }
+
+ libgl_handle = dlopen (path, RTLD_LAZY | RTLD_GLOBAL);
+ if (libgl_handle == NULL) {
+ fprintf (stderr, "Error: Failed to dlopen %s\n", path);
+ exit (1);
+ }
+}
+
+static void
+open_wrapper_handle (void)
+{
+ const char *path;
+
+ if (wrapper_handle)
+ return;
+
+ path = getenv ("GLAZE_WRAPPER");
+ if (path == NULL) {
+ fprintf (stderr, "GLAZE_WRAPPER unset. Please set to path of real libGL.so under glaze.\n");
+ exit (1);
+ }
+
+ wrapper_handle = dlopen (path, RTLD_LAZY);
+ if (wrapper_handle == NULL) {
+ fprintf (stderr, "Error: Failed to dlopen %s\n", path);
+ exit (1);
+ }
+}
+
+static void
+glaze_init (void) __attribute__((constructor));
+
+static void
+glaze_init (void)
+{
+ open_libgl_handle ();
+ open_wrapper_handle ();
+}
+
+static void *
+resolve (const char *name)
+{
+ void *symbol;
+
+ /* The wrapper gets first choice on all symbols. */
+ symbol = dlsym (wrapper_handle, name);
+ if (symbol)
+ return symbol;
+
+ return dlsym (libgl_handle, name);
+}
+
+#define GLAZE_API(name) \
+void * name() __attribute__((ifunc(#name "_resolver"))); \
+static void * \
+name ## _resolver (void) { return resolve (#name); }
+
+#include "specs/gl.def"
+#include "specs/glx.def"