evas gl: Fix usage of OSMesa

It seems OSMesa was recently updated to not expose symbols statically,
so dlsym() returns invariably NULL. GetProcAddress must be used. Note
though that the extension "EGL_KHR_get_all_proc_addresses" is not
present (OSMesa is OpenGL, not GLES), and there is anyway no list
of extensions in OSMesa (at the WSI level, glGetString() returns a
ton of GL extensions as expected).

My OSMesa version is 11.2.0 (mesa 17.0.1).

This fixes make check.

@fix

1 files changed, 14 insertions, 5 deletions

diff --git a/src/modules/evas/engines/software_generic/evas_engine.c b/src/modules/evas/engines/software_generic/evas_engine.c
index 039459c9a2..0d2bced46e 100644
--- a/src/modules/evas/engines/software_generic/evas_engine.c
+++ b/src/modules/evas/engines/software_generic/evas_engine.c
@@ -4872,14 +4872,20 @@ glue_sym_init(void)
    return 1;
 }
 
-static int
+static Eina_Bool
 gl_sym_init(void)
 {
+   Eina_Bool ok = EINA_TRUE;
+
    //------------------------------------------------//
-#define FINDSYM(dst, sym, typ) \
+#define FINDSYM(dst, sym, typ) do { \
    if (!dst) dst = (typeof(dst))dlsym(gl_lib_handle, sym); \
-   if (!dst) DBG("Symbol not found: %s", sym);
-#define FALLBAK(dst, typ) if (!dst) dst = (typeof(dst))sym_missing;
+   if (!dst && _sym_OSMesaGetProcAddress) dst = (typeof(dst))_sym_OSMesaGetProcAddress(sym); \
+   if (!dst) DBG("Symbol not found: %s", sym); \
+   } while (0)
+#define FALLBAK(dst, typ) do { \
+   if (!dst) { dst = (typeof(dst))sym_missing; ok = EINA_FALSE; } \
+   } while (0)
 
    //------------------------------------------------------//
    // GLES 2.0 APIs...
@@ -5326,7 +5332,10 @@ gl_sym_init(void)
         gl_lib_is_gles = 1;
      }
 
-   return 1;
+   if (!ok)
+     ERR("Evas failed to initialize OSMesa for OpenGL with the software engine!");
+
+   return ok;
 }
 
 //--------------------------------------------------------------//