From aa689b96e6a1f0c5c027c1e867d4afe5dc49d68f Mon Sep 17 00:00:00 2001
From: Robert Hensing <robert@roberthensing.nl>
Date: Thu, 27 Mar 2025 14:55:51 +0000
Subject: [PATCH] nix-expr/parser: Suppress warning

We rely on `yyerror()` instead.

> The variable yynerrs contains the number of syntax errors reported so
> far.
> Normally this variable is global; but if you request a pure parser
> (see A Pure (Reentrant) Parser) then it is a local variable which only
> the actions can access.

https://www.gnu.org/software/bison/manual/html_node/Error-Reporting-Function.html
---
 src/libexpr/parser.y | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/libexpr/parser.y b/src/libexpr/parser.y
index bde721401..dc58e8d53 100644
--- a/src/libexpr/parser.y
+++ b/src/libexpr/parser.y
@@ -179,7 +179,12 @@ static Expr * makeCall(PosIdx pos, Expr * fn, Expr * arg) {
 
 %%
 
-start: expr { state->result = $1; };
+start: expr {
+  state->result = $1;
+
+  // This parser does not use yynerrs; suppress the warning.
+  (void) yynerrs;
+};
 
 expr: expr_function;