glsl: Allow implicit conversion of return values.

Required by ARB_shading_language_420pack.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

diff --git a/src/glsl/ast_to_hir.cpp b/src/glsl/ast_to_hir.cpp
index e918adeef1debdcadde36e9671d976e53d5eafd4..22d0cad5079a54cc26247a36e3f3455ab0a5a107 100644 (file)
--- a/src/glsl/ast_to_hir.cpp
+++ b/src/glsl/ast_to_hir.cpp
@@ -3358,7 +3358,7 @@ ast_jump_statement::hir(exec_list *instructions,
       assert(state->current_function);
 
       if (opt_return_value) {
-        ir_rvalue *const ret = opt_return_value->hir(instructions, state);
+        ir_rvalue *ret = opt_return_value->hir(instructions, state);
 
         /* The value of the return type can be NULL if the shader says
          * 'return foo();' and foo() is a function that returns void.
@@ -3370,16 +3370,29 @@ ast_jump_statement::hir(exec_list *instructions,
         const glsl_type *const ret_type =
            (ret == NULL) ? glsl_type::void_type : ret->type;
 
-        /* Implicit conversions are not allowed for return values. */
-        if (state->current_function->return_type != ret_type) {
+         /* Implicit conversions are not allowed for return values prior to
+          * ARB_shading_language_420pack.
+          */
+         if (state->current_function->return_type != ret_type) {
            YYLTYPE loc = this->get_location();
 
-           _mesa_glsl_error(& loc, state,
-                            "`return' with wrong type %s, in function `%s' "
-                            "returning %s",
-                            ret_type->name,
-                            state->current_function->function_name(),
-                            state->current_function->return_type->name);
+            if (state->ARB_shading_language_420pack_enable) {
+               if (!apply_implicit_conversion(state->current_function->return_type,
+                                              ret, state)) {
+                  _mesa_glsl_error(& loc, state,
+                                   "Could not implicitly convert return value "
+                                   "to %s, in function `%s'",
+                                   state->current_function->return_type->name,
+                                   state->current_function->function_name());
+               }
+            } else {
+               _mesa_glsl_error(& loc, state,
+                                "`return' with wrong type %s, in function `%s' "
+                                "returning %s",
+                                ret_type->name,
+                                state->current_function->function_name(),
+                                state->current_function->return_type->name);
+            }
         }
 
         inst = new(ctx) ir_return(ret);