harec

commit b315aba134db251d9df47c75392ecf2e12531e80
parent 2a6711b038d44577cd1aca66ea666260cbecc34b
Author: Drew DeVault <sir@cmpwn.com>
Date:   Sun, 31 Jan 2021 11:06:37 -0500

check: fix issue with type assertions

Diffstat:
M
src/check.c
 | 
10
+++++++---
M
tests/18-match.ha
 | 
11
+++++++++++

2 files changed, 18 insertions(+), 3 deletions(-)
diff --git a/src/check.c b/src/check.c
@@ -544,15 +544,15 @@ check_expr_cast(struct context *ctx,
 	const struct type *secondary = expr->cast.secondary =
 		type_store_lookup_atype(ctx->store, aexpr->cast.type);
 	check_expression(ctx, aexpr->cast.value, value, secondary);
-	expect(&aexpr->cast.type->loc,
-		type_is_castable(secondary, value->result),
-		"Invalid cast");
 
 	if (aexpr->cast.kind == C_ASSERTION || aexpr->cast.kind == C_TEST) {
 		const struct type *primary = type_dealias(expr->cast.value->result);
 		expect(&aexpr->cast.value->loc,
 			primary->storage == TYPE_STORAGE_TAGGED,
 			"Expected a tagged union type");
+		expect(&aexpr->cast.type->loc,
+			type_is_castable(value->result, secondary),
+			"Invalid cast");
 		bool found = false;
 		for (const struct type_tagged_union *t = &primary->tagged;
 				t; t = t->next) {
@@ -567,6 +567,10 @@ check_expr_cast(struct context *ctx,
 
 	switch (aexpr->cast.kind) {
 	case C_CAST:
+		expect(&aexpr->cast.type->loc,
+			type_is_castable(secondary, value->result),
+			"Invalid cast");
+		// Fallthrough
 	case C_ASSERTION:
 		expr->result = secondary;
 		break;
diff --git a/tests/18-match.ha b/tests/18-match.ha
@@ -79,6 +79,16 @@ fn tagged_result() void = {
 	assert(y is uint);
 };
 
+fn implicit_cast() void = {
+	let x: foobar = foo;
+	let y: nullable *int = null;
+	let a: (int | foobar) = match (y) {
+		null => foo: foobar,
+		z: *int => *z,
+	};
+	assert(a is foobar);
+};
+
 export fn main() void = {
 	tagged();
 	termination();
@@ -86,5 +96,6 @@ export fn main() void = {
 	pointer();
 	alias();
 	tagged_result();
+	implicit_cast();
 	// TODO: Test exhaustiveness and dupe detection
 };