[PATCH vkd3d 1/5] vkd3d-shader: Treat undefined identifiers as equal to 0.

[Zebediah Figura]

Signed-off-by: Zebediah Figura 
---
 libs/vkd3d-shader/preproc.y | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/libs/vkd3d-shader/preproc.y b/libs/vkd3d-shader/preproc.y
index f9047c9f..008d01e7 100644
--- a/libs/vkd3d-shader/preproc.y
+++ b/libs/vkd3d-shader/preproc.y
@@ -588,6 +588,11 @@ expr
             $$ = preproc_parse_integer($1);
             vkd3d_free($1);
         }
+    | T_IDENTIFIER
+        {
+            $$ = 0;
+            vkd3d_free($1);
+        }
     | T_DEFINED T_IDENTIFIER
         {
             $$ = !!preproc_find_macro(ctx, $2);