fix nil check lowering

1 files changed, 27 insertions, 7 deletions

diff --git a/src/lower.c b/src/lower.c
index 1795292..3b6193f 100644
--- a/src/lower.c
+++ b/src/lower.c
@@ -112,7 +112,9 @@ static struct state create_state(struct state *parent)
 
 static size_t uniq(struct state *state)
 {
-	return state->uniq++;
+	(void)state;
+	static size_t q = 0;
+	return q++;
 }
 
 static void increase_indent(struct state *state)
@@ -656,17 +658,30 @@ static int lower_if(struct state *state, struct ast *stmt, bool last)
 
 static int lower_nil_check(struct state *state, struct ast *stmt, bool last)
 {
+	struct ast *var = nil_check_ref(stmt);
+	char *type = lower_type_str(state, var->scope, var->t);
+	char *name = mangle2(var);
+
+	fprintf(state->ctx, "  %s %s;\n", type, name);
+
 	indent(state);
-	fprintf(state->code, "if (");
+	fprintf(state->code, "ctx->%s = ", name);
 	if (lower_expr(state, nil_check_expr(stmt)))
 		return -1;
 
-	fprintf(state->code, ")\n");
+	fprintf(state->code, ";\n");
+
+	indent(state);
+	fprintf(state->code, "if (!ctx->%s)", name);
 	if (lower_block(state, nil_check_body(stmt), last))
 		return -1;
 
 	indent(state);
 	fprintf(state->code, "else\n");
+
+	free(type);
+	free(name);
+
 	return lower_block(state, nil_check_rest(stmt), last);
 }
 
@@ -710,15 +725,14 @@ static int lower_explode(struct state *state, struct ast *stmt, bool last)
 
 static int lower_let(struct state *state, struct ast *stmt, bool last)
 {
-	/* not relevant */
-	(void)last;
-
 	struct ast *var = let_var(stmt);
 	char *type = lower_type_str(state, var->scope, var->t);
 	char *name = mangle2(var);
 
+	fprintf(state->ctx, "  %s %s;\n", type, name);
+
 	indent(state);
-	fprintf(state->code, "%s %s = ", type, name);
+	fprintf(state->code, "ctx->%s = ", name);
 
 	free(type);
 	free(name);
@@ -727,6 +741,12 @@ static int lower_let(struct state *state, struct ast *stmt, bool last)
 		return -1;
 
 	fprintf(state->code, ";\n");
+
+	if (last) {
+		indent(state);
+		fprintf(state->code, "return stack;\n");
+	}
+
 	return 0;
 }