harec

commit 689bdd02034adc68233d4e93dd233ead6d508108
parent 6f6cf46d0098afac20e5cae858129f2e53d6db68
Author: Drew DeVault <sir@cmpwn.com>
Date:   Thu, 31 Dec 2020 10:37:05 -0500

gen: implement len()

Diffstat:
M
src/check.c
 | 
6
++++--
M
src/gen.c
 | 
25
+++++++++++++++++++++++--

2 files changed, 27 insertions(+), 4 deletions(-)
diff --git a/src/check.c b/src/check.c
@@ -540,8 +540,10 @@ check_expr_measure(struct context *ctx,
 		expr->measure.value = xcalloc(1, sizeof(struct expression));
 		check_expression(ctx, aexpr->measure.value, expr->measure.value);
 		enum type_storage vstor = expr->measure.value->result->storage;
-		expect(vstor == TYPE_STORAGE_ARRAY || vstor == TYPE_STORAGE_SLICE,
-			"len argument must be of an array or slice type");
+		expect(vstor == TYPE_STORAGE_ARRAY
+				|| vstor == TYPE_STORAGE_SLICE
+				|| vstor == TYPE_STORAGE_STRING,
+			"len argument must be of an array, slice, or str type");
 		expect(expr->measure.value->result->size != SIZE_UNDEFINED,
 			"Cannot take length of array type with undefined length");
 		break;
diff --git a/src/gen.c b/src/gen.c
@@ -858,10 +858,31 @@ gen_expr_measure(struct gen_context *ctx,
 	const struct expression *expr,
 	const struct qbe_value *out)
 {
-	struct qbe_value temp = {0};
+	struct qbe_value temp = {0}, ptr = {0};
 	switch (expr->measure.op) {
 	case M_LEN:
-		assert(0); // TODO
+		switch (expr->measure.value->result->storage) {
+		case TYPE_STORAGE_ARRAY:
+			gen_temp(ctx, &temp,
+				qtype_for_type(ctx, expr->result, false),
+				"len.%d");
+			constl(&temp, expr->measure.value->result->array.length);
+			gen_store(ctx, out, &temp);
+			break;
+		case TYPE_STORAGE_SLICE:
+		case TYPE_STORAGE_STRING:
+			gen_temp(ctx, &ptr, &qbe_long, "ptr.%d");
+			qval_address(&ptr);
+			gen_expression(ctx, expr->measure.value, &ptr);
+			constl(&temp, builtin_type_size.size);
+			pushi(ctx->current, &ptr, Q_ADD, &ptr, &temp, NULL);
+			qval_deref(&ptr);
+			gen_load(ctx, out, &ptr, false);
+			break;
+		default:
+			assert(0); // Invariant
+		}
+		break;
 	case M_SIZE:
 		gen_temp(ctx, &temp,
 			qtype_for_type(ctx, expr->result, false),