Mesa (master): glsl: Disallow return with a void argument from void functions.

[Matt Turner]

Module: Mesa
Branch: master
Commit: fcaa48d9cc8937e0ceb59dfd22ef5b6e6fd1a273
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=fcaa48d9cc8937e0ceb59dfd22ef5b6e6fd1a273

Author: Matt Turner <mattst88 at gmail.com>
Date:   Wed May 22 14:57:04 2013 -0700

glsl: Disallow return with a void argument from void functions.

NOTE: This is a candidate for the stable branches.

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

---

 src/glsl/ast_to_hir.cpp |   18 +++++++++++++++++-
 1 files changed, 17 insertions(+), 1 deletions(-)

diff --git a/src/glsl/ast_to_hir.cpp b/src/glsl/ast_to_hir.cpp
index 22d0cad..4b5f049 100644
--- a/src/glsl/ast_to_hir.cpp
+++ b/src/glsl/ast_to_hir.cpp
@@ -3393,7 +3393,23 @@ ast_jump_statement::hir(exec_list *instructions,
                                 state->current_function->function_name(),
                                 state->current_function->return_type->name);
             }
-	 }
+         } else if (state->current_function->return_type->base_type ==
+                    GLSL_TYPE_VOID) {
+            YYLTYPE loc = this->get_location();
+
+            /* The ARB_shading_language_420pack, GLSL ES 3.0, and GLSL 4.20
+             * specs add a clarification:
+             *
+             *    "A void function can only use return without a return argument, even if
+             *     the return argument has void type. Return statements only accept values:
+             *
+             *         void func1() { }
+             *         void func2() { return func1(); } // illegal return statement"
+             */
+            _mesa_glsl_error(& loc, state,
+                             "void functions can only use `return' without a "
+                             "return argument");
+         }
 
 	 inst = new(ctx) ir_return(ret);
       } else {