From: Paul Berry <stereotype441@gmail.com>
Date: Sun, 14 Jul 2013 15:57:49 +0000 (-0700)
Subject: glsl: Fix lower_named_interface_blocks to account for dereferences of consts.
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=428e0302100a82ab8ed5734eabd781ae36882fad;p=mesa.git

glsl: Fix lower_named_interface_blocks to account for dereferences of consts.

In certain rare cases (such as those involving dereference of a
literal constant array of structs),
flatten_named_interface_blocks_declarations's rvalue visitor may be
invoked on an ir_dereference_record whose variable_referenced() method
returns NULL.

Check for this case to avoid a segfault.

Prevents crashes in piglit tests
{vs,fs}-deref-literal-array-of-structs.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
---

diff --git a/src/glsl/lower_named_interface_blocks.cpp b/src/glsl/lower_named_interface_blocks.cpp
index 922cc024f89..d0d491d3db1 100644
--- a/src/glsl/lower_named_interface_blocks.cpp
+++ b/src/glsl/lower_named_interface_blocks.cpp
@@ -194,6 +194,8 @@ flatten_named_interface_blocks_declarations::handle_rvalue(ir_rvalue **rvalue)
       return;
 
    ir_variable *var = ir->variable_referenced();
+   if (var == NULL)
+      return;
 
    if (!var->is_interface_instance())
       return;