check for attempted writes to read-only vars

diff --git a/src/mesa/shader/slang/slang_codegen.c b/src/mesa/shader/slang/slang_codegen.c
index 1c037d4304b610befb7305c47b76587ee6276dbc..b1b4616f638c568c3b62362ec632e4b31ce61b91 100644 (file)
--- a/src/mesa/shader/slang/slang_codegen.c
+++ b/src/mesa/shader/slang/slang_codegen.c
@@ -2007,6 +2007,12 @@ _slang_gen_assignment(slang_assemble_ctx * A, slang_operation *oper)
    else {
       slang_ir_node *n, *lhs, *rhs;
       lhs = _slang_gen_operation(A, &oper->children[0]);
+      if (lhs->Store->File != PROGRAM_OUTPUT &&
+          lhs->Store->File != PROGRAM_TEMPORARY) {
+         slang_info_log_error(A->log, "Assignment to read-only variable");
+         return NULL;
+      }
+
       rhs = _slang_gen_operation(A, &oper->children[1]);
       if (lhs && rhs) {
          /* convert lhs swizzle into writemask */