[Mesa-stable] [PATCH] glsl: Disallow return with a void argument from void functions.

[Carl Worth]

From: Matt Turner <mattst88 at gmail.com>

Reviewed-by: Kenneth Graunke <kenneth at whitecape.org>
(cherry picked from commit fcaa48d9cc8937e0ceb59dfd22ef5b6e6fd1a273)

Conflicts (resolved by Carl Worth <cworth at cworth.org>):
	src/glsl/ast_to_hir.cpp

CC: mesa-stable at lists.freedesktop.org
---
 src/glsl/ast_to_hir.cpp | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/src/glsl/ast_to_hir.cpp b/src/glsl/ast_to_hir.cpp
index c5197d5..87420c6 100644
--- a/src/glsl/ast_to_hir.cpp
+++ b/src/glsl/ast_to_hir.cpp
@@ -3516,7 +3516,24 @@ ast_jump_statement::hir(exec_list *instructions,
 			     ret_type->name,
 			     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 {
-- 
1.8.3.1