src/waffle/wayland/wayland_wrapper.c

   1 // Copyright 2015 Emil Velikov
   2 //
   3 // All rights reserved.
   4 //
   5 // Redistribution and use in source and binary forms, with or without
   6 // modification, are permitted provided that the following conditions are met:
   7 //
   8 // - Redistributions of source code must retain the above copyright notice, this
   9 //   list of conditions and the following disclaimer.
  10 //
  11 // - Redistributions in binary form must reproduce the above copyright notice,
  12 //   this list of conditions and the following disclaimer in the documentation
  13 //   and/or other materials provided with the distribution.
  14 //
  15 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  16 // AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  17 // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  18 // DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
  19 // FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  20 // DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  21 // SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  22 // CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  23 // OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  24 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25
  26 /// @file
  27 /// @brief Wrappers for Wayland-client functions
  28 ///
  29 /// Many of the wayland functions are defined as static inline within the
  30 /// public headers. In order to avoid the static(link-time) dependency, we
  31 /// provide the required symbols with this file.
  32 ///
  33 /// This is achieved by declaring wrapper functions, around which we define the
  34 /// needed (base) wayland ones. After that we include the public header, at
  35 /// which point the pre-processor/compiler will use our defines.
  36 ///
  37 /// Each wrapper is initialised via dlsym to retrieve the relevant symbol from
  38 /// the library libwayland-client.so.0
  39
  40
  41 #include <stdbool.h>
  42 #include <dlfcn.h>
  43
  44 #include "wcore_error.h"
  45
  46 #include "wayland_wrapper.h"
  47
  48 // dlopen handle for libwayland-client.so.0
  49 static void *dl_wl_client;
  50
  51 static const char *libwl_client_filename = "libwayland-client.so.0";
  52
  53 bool
  54 wayland_wrapper_teardown(void)
  55 {
  56     bool ok = true;
  57     int error;
  58
  59     if (dl_wl_client) {
  60         error = dlclose(dl_wl_client);
  61         if (error) {
  62             ok &= false;
  63             wcore_errorf(WAFFLE_ERROR_UNKNOWN,
  64                          "dlclose(\"%s\") failed: %s",
  65                          libwl_client_filename, dlerror());
  66         }
  67     }
  68
  69     return ok;
  70 }
  71
  72 bool
  73 wayland_wrapper_init(void)
  74 {
  75     bool ok = true;
  76
  77     dl_wl_client = dlopen(libwl_client_filename, RTLD_LAZY | RTLD_LOCAL);
  78     if (!dl_wl_client) {
  79         wcore_errorf(WAFFLE_ERROR_FATAL,
  80                      "dlopen(\"%s\") failed: %s",
  81                      libwl_client_filename, dlerror());
  82         ok = false;
  83         goto error;
  84     }
  85
  86 #define RETRIEVE_WL_CLIENT_SYMBOL(S)                            \
  87     wfl_##S = (__typeof__(wfl_##S))dlsym(dl_wl_client, #S);     \
  88     if (!wfl_##S) {                                             \
  89         wcore_errorf(WAFFLE_ERROR_FATAL,                        \
  90                      "dlsym(\"%s\", \"" #S "\") failed: %s",    \
  91                      libwl_client_filename, dlerror());         \
  92         ok = false;                                             \
  93         goto error;                                             \
  94     }
  95
  96     RETRIEVE_WL_CLIENT_SYMBOL(wl_compositor_interface);
  97     RETRIEVE_WL_CLIENT_SYMBOL(wl_registry_interface);
  98     RETRIEVE_WL_CLIENT_SYMBOL(wl_shell_interface);
  99     RETRIEVE_WL_CLIENT_SYMBOL(wl_shell_surface_interface);
 100     RETRIEVE_WL_CLIENT_SYMBOL(wl_surface_interface);
 101
 102     RETRIEVE_WL_CLIENT_SYMBOL(wl_display_connect);
 103     RETRIEVE_WL_CLIENT_SYMBOL(wl_display_disconnect);
 104     RETRIEVE_WL_CLIENT_SYMBOL(wl_display_roundtrip);
 105     RETRIEVE_WL_CLIENT_SYMBOL(wl_proxy_destroy);
 106     RETRIEVE_WL_CLIENT_SYMBOL(wl_proxy_add_listener);
 107     RETRIEVE_WL_CLIENT_SYMBOL(wl_proxy_marshal);
 108     RETRIEVE_WL_CLIENT_SYMBOL(wl_proxy_marshal_constructor);
 109     RETRIEVE_WL_CLIENT_SYMBOL(wl_proxy_marshal_constructor_versioned);
 110 #undef RETRIEVE_WL_CLIENT_SYMBOL
 111
 112 error:
 113     // On failure the caller of wayland_wrapper_init will trigger it's own
 114     // destruction which will execute wayland_wrapper_teardown.
 115     return ok;
 116 }