harec

commit 95e3f2e9ce8389bb63b49cf728f3d93a3609507a
parent 95aba73afa70bb5d314541b98d003988c96398d6
Author: Karl Schultheisz <k@kdsch.org>
Date:   Tue, 26 Apr 2022 12:13:35 -0400

check: reject return statement not in function

Fix segfaults for incorrect code like

	let x: [return 0]int;

by failing gracefully if a return statement appears outside of
a function body. The parser accepts this syntax because it only looks
for an expression in the array length, not the subset of expressions
that could be valid array lengths.

Signed-off-by: Karl Schultheisz <k@kdsch.org>

Diffstat:
M
src/check.c
 | 
4
++++

1 file changed, 4 insertions(+), 0 deletions(-)
diff --git a/src/check.c b/src/check.c
@@ -2129,6 +2129,10 @@ check_expr_return(struct context *ctx,
 			"Cannot return inside a defer expression");
 		return;
 	}
+	if (ctx->fntype == NULL) {
+		error(ctx, aexpr->loc, expr, "Cannot return outside a function body");
+		return;
+	}
 	if (ctx->fntype->func.flags & FN_NORETURN) {
 		error(ctx, aexpr->loc, expr,
 			"Cannot return inside @noreturn function");