move stack pointer

1 files changed, 44 insertions, 3 deletions

diff --git a/src/main.c b/src/main.c
index fb90340..3944956 100644
--- a/src/main.c
+++ b/src/main.c
@@ -164,6 +164,7 @@ typedef enum {
 	NOD_WORD,
 	NOD_FNCALL,
 	NOD_GLOBAL,
+	NOD_LOCAL,
 } NodeType;
 
 typedef struct Node Node;
@@ -188,6 +189,14 @@ node_size(const Node *node)
 	return size;
 }
 
+static Node *
+node_tail(Node *node)
+{
+	while (node != NULL && node->next != NULL)
+		node = node->next;
+	return node;
+}
+
 static bool
 node_equal(const Node *node, const char *op)
 {
@@ -241,6 +250,7 @@ new_num(int val)
 static Node *stmt(Token **rest, Token *tok);
 static Node *function(Token **rest, Token *tok);
 static Node *global(Token **rest, Token *tok);
+static Node *local(Token **rest, Token *tok);
 static Node *expr(Token **rest, Token *tok);
 static Node *expr_stmt(Token **rest, Token *tok);
 static Node *return_stmt(Token **rest, Token *tok);
@@ -276,6 +286,10 @@ function(Token **rest, Token *tok)
 
 	head.next = NULL;
 	cur = &head;
+
+	while (tok->type != TOK_EOF && equal(tok, "local"))
+		cur = cur->next = local(&tok, tok);
+
 	while (tok->type != TOK_EOF && !equal(tok, "}"))
 		cur = cur->next = stmt(&tok, tok);
 	tok = skip(tok, "}");
@@ -305,6 +319,15 @@ global(Token **rest, Token *tok)
 }
 
 static Node *
+local(Token **rest, Token *tok)
+{
+	tok = skip(tok, "local");
+	Node *const node = new_unary(NOD_LOCAL, new_word(tok));
+	*rest = skip(tok->next, ";");
+	return node;
+}
+
+static Node *
 expr(Token **rest, Token *tok)
 {
 	return equality(rest, tok);
@@ -600,13 +623,26 @@ gen_globalget(Node *node)
 static void
 gen_function(Node *node)
 {
+	Node *const ognode = node;
 	printf("@__fn_%.*s\n", node->lhs->len, node->lhs->loc);
 
 	/* GOTO */
 	locals = node->lhs->next;
-	fprintf(stderr, "argcount %d\n", node_size(locals));
+	const int argcount = node_size(locals);
 
+	Node *cur = node_tail(locals);
 	node = node->rhs;
+	while (node->type == NOD_LOCAL) {
+		cur = cur->next = node->lhs;
+		node = node->next;
+	}
+
+	const int locals_size = node_size(locals);
+
+	printf("\tLIT ,__stack_ptr LDA\n");
+	printf("\tLIT %04x ADD\n", locals_size);
+	printf("\tLIT ,__stack_ptr STA\n");
+
 	while (node != NULL) {
 		switch (node->type) {
 		case NOD_EXPR_STMT:
@@ -616,7 +652,7 @@ gen_function(Node *node)
 			break;
 		case NOD_RETURN_STMT:
 			gen_expr(node->lhs);
-			printf("\tRET\n");
+			printf("\tJMP ,__fnret_%.*s\n", ognode->lhs->len, ognode->lhs->loc);
 			depth -= 1;
 			break;
 		case NOD_WRT_STMT:
@@ -636,7 +672,12 @@ gen_function(Node *node)
 		node = node->next;
 	}
 
-	printf("\tLIT 0000 ( default return )\n\tRET\n");
+	printf("\tLIT 0000 ( default return )\n");
+	printf("@__fnret_%.*s\n", ognode->lhs->len, ognode->lhs->loc);
+	printf("\tLIT ,__stack_ptr LDA\n");
+	printf("\tLIT %04x SUB\n", locals_size);
+	printf("\tLIT ,__stack_ptr STA\n");
+	printf("\tRET\n");
 }
 
 static void