harec

commit b74b70a610d9f6b226dac14cabf945cd84ef3290
parent ea6d4c92cd331f1177eaea69e41d3d91a116b130
Author: Drew DeVault <sir@cmpwn.com>
Date:   Sat, 26 Dec 2020 13:47:37 -0500

check: implement index access

Diffstat:
M
include/ast.h
 | 
2
+-
M
include/expr.h
 | 
10
++++++++--
M
src/check.c
 | 
40
+++++++++++++++++++++++++++++-----------
M
src/parse.c
 | 
2
+-

4 files changed, 39 insertions(+), 15 deletions(-)
diff --git a/include/ast.h b/include/ast.h
@@ -102,7 +102,7 @@ struct ast_expression_access {
 	union {
 		struct identifier ident;
 		struct {
-			struct ast_expression *object;
+			struct ast_expression *array;
 			struct ast_expression *index;
 		};
 		// TODO: Field selection
diff --git a/include/expr.h b/include/expr.h
@@ -38,9 +38,15 @@ enum access_type {
 };
 
 struct expression_access {
-	const struct scope_object *object;
 	enum access_type type;
-	// TODO: Details for index, field selection
+	union {
+		const struct scope_object *object;
+		struct {
+			struct expression *array;
+			struct expression *index;
+		};
+		// TODO: Field selection
+	};
 };
 
 struct expression_assign {
diff --git a/src/check.c b/src/check.c
@@ -41,18 +41,36 @@ check_expr_access(struct context *ctx,
 	const struct ast_expression *aexpr,
 	struct expression *expr)
 {
-	char buf[1024];
-	identifier_unparse_static(&aexpr->access.ident, buf, sizeof(buf));
-
-	trace(TR_CHECK, "access %s", buf);
+	trace(TR_CHECK, "access");
 	expr->type = EXPR_ACCESS;
-
-	const struct scope_object *obj = scope_lookup(
-		ctx->scope, &aexpr->access.ident);
-	expect(obj, "Unknown object %s", buf);
-
-	expr->result = obj->type;
-	expr->access.object = obj;
+	expr->access.type = aexpr->access.type;
+
+	const struct scope_object *obj;
+	switch (expr->access.type) {
+	case ACCESS_IDENTIFIER:
+		obj = scope_lookup(ctx->scope, &aexpr->access.ident);
+		char buf[1024];
+		identifier_unparse_static(&aexpr->access.ident, buf, sizeof(buf));
+		expect(obj, "Unknown object", buf);
+		expr->result = obj->type;
+		expr->access.object = obj;
+		break;
+	case ACCESS_INDEX:
+		expr->access.array = xcalloc(1, sizeof(struct expression));
+		expr->access.index = xcalloc(1, sizeof(struct expression));
+		check_expression(ctx, aexpr->access.array, expr->access.array);
+		check_expression(ctx, aexpr->access.index, expr->access.index);
+		const struct type *atype = expr->access.array->result;
+		const struct type *itype = expr->access.index->result;
+		expect(atype->storage == TYPE_STORAGE_ARRAY
+				|| atype->storage == TYPE_STORAGE_SLICE,
+			"Cannot index non-array, non-slice object");
+		expect(type_is_integer(itype), "Cannot use non-integer type as slice/array index");
+		expr->result = atype->array.members;
+		break;
+	case ACCESS_FIELD:
+		assert(0); // TODO
+	}
 }
 
 static void
diff --git a/src/parse.c b/src/parse.c
@@ -876,7 +876,7 @@ parse_index_slice_expression(struct parser *par, struct ast_expression *lvalue)
 	if (!is_slice) {
 		exp->type = EXPR_ACCESS;
 		exp->access.type = ACCESS_INDEX;
-		exp->access.object = lvalue;
+		exp->access.array = lvalue;
 		exp->access.index = start;
 		trleave(TR_PARSE, "slice-index (index)");
 		return exp;