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/*
* 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 (including the next
* paragraph) 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.
*/
#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)
{
fprintf(stderr, "An updated DRI driver loader (libGL.so or X Server) is "
"required for this Mesa driver.\n");
return NULL;
}
/**
* This is a stub driDriverAPI that is referenced by dri_util.c but should
* never be used.
*/
const struct __DriverAPIRec driDriverAPI = {
.InitScreen = stub_error_init_screen,
};
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