[gtk/wip/otte/conic: 1/3] glrenderer: Emit more useful error messages

[Benjamin Otte <otte src gnome org>]

commit d1e8772740d33ebc0c0e1365fc563ea818169364
Author: Benjamin Otte <otte redhat com>
Date:   Thu Dec 3 05:33:30 2020 +0100

    glrenderer: Emit more useful error messages
    
    In particular, don't print some random string, blame ourselves for not
    tracking what went wrong.

 gsk/gl/gskglrenderer.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
---
diff --git a/gsk/gl/gskglrenderer.c b/gsk/gl/gskglrenderer.c
index bb09be8bdd..cff7b77c6e 100644
--- a/gsk/gl/gskglrenderer.c
+++ b/gsk/gl/gskglrenderer.c
@@ -54,6 +54,8 @@
                               glGetUniformLocation(programs->program_name ## _program.id, "u_" 
#uniform_basename);\
                 if (programs->program_name ## _program.program_name.uniform_basename ## _location == -1) \
                   { \
+                    g_set_error (error, GDK_GL_ERROR, GDK_GL_ERROR_LINK_FAILED, \
+                                 "Failed to find variable \"u_%s\" in shader", #uniform_basename); \
                     g_clear_pointer (&programs, gsk_gl_renderer_programs_unref); \
                     goto out; \
                   } \
@@ -3363,7 +3365,7 @@ out:
 
   if (error && !(*error) && !programs)
     g_set_error (error, GDK_GL_ERROR, GDK_GL_ERROR_COMPILATION_FAILED,
-                 "Failed to compile all shader programs"); /* Probably, eh. */
+                 "Failed to emit an error in the correct place - now compilation failed and we don't know 
why."); /* Probably, eh. */
 
   return programs;
 }