function call

3 files changed, 77 insertions, 7 deletions

diff --git a/Tupfile b/Tupfile
index 4b55aec..d01672e 100644
--- a/Tupfile
+++ b/Tupfile
@@ -1,6 +1,6 @@
 CC     = gcc
 LD     = $(CC)
-CFLAGS = -std=c99 -Wall -Wextra
+CFLAGS = -O0 -g3 -std=c99 -Wall -Wextra
 LIBS   =
 NAME   = golem
 
diff --git a/src/main.c b/src/main.c
index afc74dc..dbe70c0 100644
--- a/src/main.c
+++ b/src/main.c
@@ -44,7 +44,7 @@ static void
 expect(const Token *tok, TokenType type)
 {
 	if (tok->type != type)
-		error("expected a %s", str_tok[type]);
+		error("expected a %s, got %s", str_tok[type], str_tok[tok->type]);
 }
 
 static bool
@@ -149,8 +149,10 @@ typedef enum {
 	NOD_LE,  // <=
 	NOD_NUM, // integer
 	NOD_EXPR_STMT,
+	NOD_RETURN_STMT,
 	NOD_FUN,
 	NOD_WORD,
+	NOD_FNCALL,
 } NodeType;
 
 typedef struct Node Node;
@@ -212,6 +214,7 @@ static Node *stmt(Token **rest, Token *tok);
 static Node *function(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);
 static Node *equality(Token **rest, Token *tok);
 static Node *relational(Token **rest, Token *tok);
 static Node *add(Token **rest, Token *tok);
@@ -366,6 +369,29 @@ primary(Token **rest, Token *tok)
 		return node;
 	}
 
+	if (tok->type == TOK_WORD) {
+		/* function call */
+		Node *node = new_word(tok);
+		tok = tok->next;
+		node->type = NOD_FNCALL;
+
+		/* args */
+		Node head = {0};
+		Node *cur = &head;
+
+		tok = skip(tok, "(");
+		while (tok->type != TOK_EOF && !equal(tok, ")")) {
+			cur = cur->next = expr(&tok, tok);
+			if (equal(tok, ","))
+				tok = tok->next;
+		}
+		*rest = skip(tok, ")");
+
+		node->rhs = head.next;
+		return node;
+	}
+
+	printf("'%.*s'\n", tok->len, tok->loc);
 	error("expected an expression");
 	return NULL;
 }
@@ -373,6 +399,8 @@ primary(Token **rest, Token *tok)
 static Node *
 stmt(Token **rest, Token *tok)
 {
+	if (equal(tok, "return"))
+		return return_stmt(rest, tok);
 	return expr_stmt(rest, tok);
 }
 
@@ -384,10 +412,22 @@ static Node
 	return node;
 }
 
+static Node
+*return_stmt(Token **rest, Token *tok)
+{
+	tok = skip(tok, "return");
+	Node *const node = new_unary(NOD_RETURN_STMT, expr(&tok, tok));
+	*rest = skip(tok, ";");
+	return node;
+}
+
 // code generator
 
 static int depth;
 
+static void gen_expr(Node *node);
+static void gen_fncall(Node *node);
+
 static void
 gen_expr(Node *node)
 {
@@ -397,6 +437,11 @@ gen_expr(Node *node)
 		return;
 	}
 
+	if (node->type == NOD_FNCALL) {
+		gen_fncall(node);
+		return;
+	}
+
 	gen_expr(node->lhs);
 	gen_expr(node->rhs);
 
@@ -434,16 +479,39 @@ gen_expr(Node *node)
 }
 
 static void
+gen_fncall(Node *node)
+{
+	printf("\t( function call )\n");
+	Node *cur = node->rhs;
+	while (cur != NULL) {
+		gen_expr(cur);
+		depth -= 1;
+		cur = cur->next;
+	}
+	printf("\tJRT ,__fn_%.*s\n", node->len, node->loc);
+	depth += 1;
+}
+
+static void
 gen_function(Node *node)
 {
-	printf("@_fn_%.*s\n", node->lhs->len, node->lhs->loc);
+	printf("@__fn_%.*s\n", node->lhs->len, node->lhs->loc);
 
 	node = node->rhs;
 	while (node != NULL) {
-		gen_expr(node->lhs);
-		while (depth) {
+		switch (node->type) {
+		case NOD_EXPR_STMT:
+			gen_expr(node->lhs);
 			printf("\tPOP ( discard stack )\n");
 			depth -= 1;
+			break;
+		case NOD_RETURN_STMT:
+			gen_expr(node->lhs);
+			printf("\tRET\n");
+			depth -= 1;
+			break;
+		default:
+			error("unexpected %d", node->type);
 		}
 		node = node->next;
 	}
@@ -481,8 +549,9 @@ main(int argc, char **argv)
 
 	Node *node = parse(tok);
 
-	printf("\tJMP ,_fn_main ( entry point )\n");
+	printf("\tJMP ,__fn_main ( entry point )\n");
 	codegen(node);
+	printf("@__stack\n");
 
 	assert(depth == 0);
 	return 0;
diff --git a/testing.sh b/testing.sh
index f6f0083..40f93c2 100755
--- a/testing.sh
+++ b/testing.sh
@@ -11,7 +11,8 @@ function test() {
 }
 
 tup || exit 1
-test "main(){5 + 2;}"
+test "main(){5 + 2; return 4;}"
 test "main(){6 + 3;}"
 test "main(){'a' - 'b';}"
+test "main() { fizz(50 + buzz() - 3) * 4; } fizz(x) { return 3; } buzz() { return 42; }"
 rm -f build/tmp.*