harec

commit 07e888e539e618dd5ccc16c0f0325d74d373a2b5
parent aef98a91675367e7d408d56488f82c2e1c78e29a
Author: Alexey Yerin <yyp@disroot.org>
Date:   Wed, 15 Feb 2023 16:20:20 +0300

check: disallow dereferencing void pointers

The following code used to crash harec:

    export fn main() void = {
    	let a: *void = &12;
    	*a;
    };

Signed-off-by: Alexey Yerin <yyp@disroot.org>

Diffstat:
M
src/check.c
 | 
5
+++++
M
tests/03-pointers.ha
 | 
8
++++++++

2 files changed, 13 insertions(+), 0 deletions(-)
diff --git a/src/check.c b/src/check.c
@@ -3107,6 +3107,11 @@ check_expr_unarithm(struct context *ctx,
 				"Cannot dereference nullable pointer type");
 			return;
 		}
+		if (type_dealias(operand->result)->pointer.referent->size == 0) {
+			error(ctx, aexpr->unarithm.operand->loc, expr,
+				"Cannot dereference pointer to zero-sized type");
+			return;
+		}
 		if (type_dealias(operand->result)->pointer.referent->size
 				== SIZE_UNDEFINED) {
 			error(ctx, aexpr->unarithm.operand->loc, expr,
diff --git a/tests/03-pointers.ha b/tests/03-pointers.ha
@@ -128,6 +128,14 @@ fn reject() void = {
 		let b: *int = &a;
 		let c: int = *b;
 	") as exited != EXIT_SUCCESS);
+
+	// dereference of a zero-sized type
+	assert(compile("
+		fn test() void = {
+			let a: *void = &12;
+			*a;
+		};
+	") as exited != EXIT_SUCCESS);
 };
 
 export fn main() void = {