harec

commit 4ae764e204cb7d63f5653583c4823b7fd265032b
parent 000a268c4c1e348e613dec9545bb52cb64c9ab67
Author: Drew DeVault <sir@cmpwn.com>
Date:   Wed, 20 Jan 2021 09:46:49 -0500

check: implement defer

Diffstat:
M
include/ast.h
 | 
2
+-
M
include/check.h
 | 
1
+
M
include/expr.h
 | 
5
+++++
M
src/check.c
 | 
19
++++++++++++++++++-
M
src/parse.c
 | 
2
+-

5 files changed, 26 insertions(+), 3 deletions(-)
diff --git a/include/ast.h b/include/ast.h
@@ -210,7 +210,7 @@ struct ast_expression_control {
 };
 
 struct ast_expression_defer {
-	struct ast_expression *expression;
+	struct ast_expression *deferred;
 };
 
 struct ast_expression_for {
diff --git a/include/check.h b/include/check.h
@@ -14,6 +14,7 @@ struct context {
 	struct identifier *ns;
 	struct scope *unit;
 	struct scope *scope;
+	bool deferring;
 	int id;
 };
 
diff --git a/include/expr.h b/include/expr.h
@@ -144,6 +144,10 @@ struct expression_control {
 	char *label;
 };
 
+struct expression_defer {
+	struct expression *deferred;
+};
+
 struct expression_for {
 	char *label;
 	struct scope *scope;
@@ -241,6 +245,7 @@ struct expression {
 		struct expression_call call;
 		struct expression_cast cast;
 		union expression_constant constant;
+		struct expression_defer defer;
 		struct expression_control control;
 		struct expression_for _for;
 		struct expression_if _if;
diff --git a/src/check.c b/src/check.c
@@ -607,6 +607,22 @@ check_expr_constant(struct context *ctx,
 }
 
 static void
+check_expr_defer(struct context *ctx,
+	const struct ast_expression *aexpr,
+	struct expression *expr,
+	const struct type *hint)
+{
+	expect(&aexpr->loc, !ctx->deferring,
+		"Cannot defer within another defer expression.");
+	expr->type = EXPR_DEFER;
+	expr->result = &builtin_type_void;
+	expr->defer.deferred = xcalloc(1, sizeof(struct expression));
+	ctx->deferring = true;
+	check_expression(ctx, aexpr->defer.deferred, expr->defer.deferred, NULL);
+	ctx->deferring = false;
+}
+
+static void
 check_expr_control(struct context *ctx,
 	const struct ast_expression *aexpr,
 	struct expression *expr,
@@ -1123,7 +1139,8 @@ check_expression(struct context *ctx,
 		check_expr_constant(ctx, aexpr, expr, hint);
 		break;
 	case EXPR_DEFER:
-		assert(0);
+		check_expr_defer(ctx, aexpr, expr, hint);
+		break;
 	case EXPR_FOR:
 		check_expr_for(ctx, aexpr, expr, hint);
 		break;
diff --git a/src/parse.c b/src/parse.c
@@ -1045,7 +1045,7 @@ parse_defer_expression(struct lexer *lexer)
 	struct ast_expression *exp = mkexpr(&lexer->loc);
 	want(lexer, T_DEFER, NULL);
 	exp->type = EXPR_DEFER;
-	exp->defer.expression = parse_scope_expression(lexer);
+	exp->defer.deferred = parse_scope_expression(lexer);
 	return exp;
 }