glsl: Track in each ir_variable whether it was ever assigned.

This will be used for some compile-and-link-time error checking, where
currently we've been doing error checking only at link time.

Reviewed-by: Kenneth Graunke <[email protected]>

1 files changed, 13 insertions, 0 deletions

diff --git a/src/glsl/ir.h b/src/glsl/ir.h
index d6c6a607ae8..ddfaf3614ae 100644
--- a/src/glsl/ir.h
+++ b/src/glsl/ir.h
@@ -353,10 +353,23 @@ public:
     * Several GLSL semantic checks require knowledge of whether or not a
     * variable has been used.  For example, it is an error to redeclare a
     * variable as invariant after it has been used.
+    *
+    * This is only maintained in the ast_to_hir.cpp path, not in
+    * Mesa's fixed function or ARB program paths.
     */
    unsigned used:1;
 
    /**
+    * Has this variable been statically assigned?
+    *
+    * This answers whether the variable was assigned in any path of
+    * the shader during ast_to_hir.  This doesn't answer whether it is
+    * still written after dead code removal, nor is it maintained in
+    * non-ast_to_hir.cpp (GLSL parsing) paths.
+    */
+   unsigned assigned:1;
+
+   /**
     * Storage class of the variable.
     *
     * \sa ir_variable_mode