[Mesa-dev] [PATCH 06/11] glsl: Cross-validate explicit binding points.

[Kenneth Graunke]

All compilation units need to agree on the binding point, if they
specify one at all.

Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>
---
 src/glsl/linker.cpp | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/src/glsl/linker.cpp b/src/glsl/linker.cpp
index ba97ade..cca66f8 100644
--- a/src/glsl/linker.cpp
+++ b/src/glsl/linker.cpp
@@ -541,6 +541,28 @@ cross_validate_globals(struct gl_shader_program *prog,
 	       existing->explicit_location = true;
 	    }
 
+            /* From the GLSL 4.20 specification:
+             * "A link error will result if two compilation units in a program
+             *  specify different integer-constant bindings for the same
+             *  opaque-uniform name.  However, it is not an error to specify a
+             *  binding on some but not all declarations for the same name"
+             */
+            if (var->explicit_binding) {
+               assert(var->constant_value);
+               assert(!existing->explicit_binding || existing->constant_value);
+               if (existing->explicit_binding &&
+                   var->constant_value->value.i[0] !=
+                   existing->constant_value->value.i[0]) {
+                  linker_error(prog, "explicit bindings for %s "
+                               "`%s' have differing values\n",
+                               mode_string(var), var->name);
+                  return false;
+               }
+
+               existing->constant_value = var->constant_value;
+               existing->explicit_binding = true;
+            }
+
 	    /* Validate layout qualifiers for gl_FragDepth.
 	     *
 	     * From the AMD/ARB_conservative_depth specs:
-- 
1.8.3.2