harec

commit 9aa447a7047b249c7649abfc339841e28525c765
parent 87f934c68d3cb6a24aaa6cdc0f9cf1a5a5981992
Author: Eyal Sawady <ecs@d2evs.net>
Date:   Fri,  5 Feb 2021 12:16:59 -0500

check: implement if with tagged union result

Diffstat:
M
src/check.c
 | 
16
+++++++++++++---
M
src/gen.c
 | 
2
+-

2 files changed, 14 insertions(+), 4 deletions(-)
diff --git a/src/check.c b/src/check.c
@@ -941,11 +941,21 @@ check_expr_if(struct context *ctx,
 			expr->result = false_branch->result;
 		} else if (false_branch->terminates) {
 			expr->result = true_branch->result;
-		} else {
-			// TODO: Tagged unions
-			assert(true_branch->result == false_branch->result);
+		} else if (true_branch->result == false_branch->result) {
 			expr->result = true_branch->result;
+		} else {
+			struct type_tagged_union _tags = {
+				.type = false_branch->result,
+				.next = NULL,
+			}, tags = {
+				.type = true_branch->result,
+				.next = &_tags,
+			};
+			expr->result =
+				type_store_lookup_tagged(ctx->store, &tags);
 		}
+		true_branch = lower_implicit_cast(expr->result, true_branch);
+		false_branch = lower_implicit_cast(expr->result, false_branch);
 	} else {
 		expr->result = &builtin_type_void;
 		expr->terminates = true_branch->terminates;
diff --git a/src/gen.c b/src/gen.c
@@ -1082,7 +1082,7 @@ gen_expr_type_assertion(struct gen_context *ctx,
 	      *tagged = type_dealias(expr->cast.value->result);
 	struct qbe_value tag = {0}, in = {0}, id = {0}, result = {0};
 	gen_temp(ctx, &tag, &qbe_word, "tag.%d");
-	gen_temp(ctx, &in, qtype_for_type(ctx, tagged, false), "cast.in.%d");
+	alloc_temp(ctx, &in, tagged, "cast.in.%d");
 	qval_address(&in);
 	gen_expression(ctx, expr->cast.value, &in);
 	pushi(ctx->current, &tag, Q_LOADUW, &in, NULL);