From e7ca2ab9e12e34c346b033ec6862f2d7cb5228f0 Mon Sep 17 00:00:00 2001
From: schaeff <thibaut@schaeff.fr>
Date: Mon, 22 Jan 2018 18:37:16 +0100
Subject: [PATCH] catch undefined variables in return statements

---
 src/semantics.rs | 28 +++++++++++++++++++++++++++-
 1 file changed, 27 insertions(+), 1 deletion(-)

diff --git a/src/semantics.rs b/src/semantics.rs
index d55da048..3def7524 100644
--- a/src/semantics.rs
+++ b/src/semantics.rs
@@ -183,7 +183,10 @@ impl Checker {
 				Ok(())
 			}
 			Expression::Number(_) => Ok(()),
-			Expression::List(values) => {
+			Expression::List(exprs) => {
+				for expr in exprs {
+					self.check_expression(expr)?
+				}
 				Ok(())
 			}
 		}
@@ -443,4 +446,27 @@ mod tests {
 		let mut checker = Checker::new_with_args(HashSet::new(), 0, HashSet::new());
 		assert_eq!(checker.check_function(bar), Err(("Function definition for function ??? with ??? argument(s) not found.".to_string())));
 	}
+
+	#[test]
+	fn return_undefined() {
+		// def bar():
+		//   return a, b
+		// should fail
+		let bar_statements: Vec<Statement<FieldPrime>> = vec![Statement::Return(
+			Expression::List(vec![
+				Expression::Identifier("a".to_string()),
+				Expression::Identifier("b".to_string())
+			])
+		)];
+
+		let bar = Function {
+			id: "bar".to_string(),
+			arguments: vec![],
+			statements: bar_statements,
+			return_count: 2
+		};
+
+		let mut checker = Checker::new_with_args(HashSet::new(), 0, HashSet::new());
+		assert_eq!(checker.check_function(bar), Err(("\"a\" is undefined".to_string())));
+	}
 }
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