global assign

2 files changed, 98 insertions, 13 deletions

diff --git a/src/main.c b/src/main.c
index 0d810af..f082416 100644
--- a/src/main.c
+++ b/src/main.c
@@ -44,7 +44,8 @@ static void
 expect(const Token *tok, TokenType type)
 {
 	if (tok->type != type)
-		error("expected a %s, got %s", str_tok[type], str_tok[tok->type]);
+		error("expected a %s, got %s '%.*s'",
+		      str_tok[type], str_tok[tok->type], tok->len, tok->loc);
 }
 
 static bool
@@ -86,7 +87,7 @@ is_punct(const char *p)
 	if (strchr("=!<>", p[0]) != NULL && p[1] == '=')
 		return 2;
 
-	return (strchr("+-/*()<>,;{}", p[0]) != NULL);
+	return (strchr("+-/*()<>,;{}=", p[0]) != NULL);
 }
 
 static Token *
@@ -131,7 +132,7 @@ tokenize(char *p)
 			continue;
 		}
 
-		error("invalid token");
+		error("invalid token '%c'", *p);
 	}
 	cur->next = new_token(TOK_EOF, p, p);
 
@@ -150,9 +151,11 @@ typedef enum {
 	NOD_NUM, // integer
 	NOD_EXPR_STMT,
 	NOD_RETURN_STMT,
+	NOD_ASSIGN_STMT,
 	NOD_FUN,
 	NOD_WORD,
 	NOD_FNCALL,
+	NOD_GLOBAL,
 } NodeType;
 
 typedef struct Node Node;
@@ -212,9 +215,11 @@ 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 *expr(Token **rest, Token *tok);
 static Node *expr_stmt(Token **rest, Token *tok);
 static Node *return_stmt(Token **rest, Token *tok);
+static Node *assign_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);
@@ -253,6 +258,24 @@ function(Token **rest, Token *tok)
 }
 
 static Node *
+global(Token **rest, Token *tok)
+{
+	tok = skip(tok, "global");
+	Node *const node = new_word(tok);
+	node->type = NOD_GLOBAL;
+
+	tok = tok->next;
+	if (equal(tok, "=")) {
+		tok = tok->next;
+		node->val = get_number(tok);
+		tok = tok->next;
+	}
+
+	*rest = skip(tok, ";");
+	return node;
+}
+
+static Node *
 expr(Token **rest, Token *tok)
 {
 	return equality(rest, tok);
@@ -369,7 +392,7 @@ primary(Token **rest, Token *tok)
 		return node;
 	}
 
-	if (tok->type == TOK_WORD) {
+	if (tok->type == TOK_WORD && equal(tok->next, "(")) {
 		/* function call */
 		Node *node = new_word(tok);
 		tok = tok->next;
@@ -391,6 +414,13 @@ primary(Token **rest, Token *tok)
 		return node;
 	}
 
+	if (tok->type == TOK_WORD) {
+		/* variable */
+		Node *node = new_word(tok);
+		*rest = tok->next;
+		return node;
+	}
+
 	printf("'%.*s'\n", tok->len, tok->loc);
 	error("expected an expression");
 	return NULL;
@@ -401,6 +431,8 @@ stmt(Token **rest, Token *tok)
 {
 	if (equal(tok, "return"))
 		return return_stmt(rest, tok);
+	if (equal(tok->next, "="))
+		return assign_stmt(rest, tok);
 	return expr_stmt(rest, tok);
 }
 
@@ -421,12 +453,25 @@ static Node
 	return node;
 }
 
+static Node
+*assign_stmt(Token **rest, Token *tok)
+{
+	expect(tok, TOK_WORD);
+	skip(tok->next, "=");
+	Node *const word = new_word(tok);
+	Node *const node = new_binary(NOD_ASSIGN_STMT, word, expr(&tok, tok->next->next));
+	*rest = skip(tok, ";");
+	return node;
+}
+
 // code generator
 
 static int depth;
 
 static void gen_expr(Node *node);
+static void gen_globaldec(Node *node);
 static void gen_fncall(Node *node);
+static void gen_globalget(Node *node);
 
 static void
 gen_expr(Node *node)
@@ -442,6 +487,11 @@ gen_expr(Node *node)
 		return;
 	}
 
+	if (node->type == NOD_WORD) {
+		gen_globalget(node);
+		return;
+	}
+
 	gen_expr(node->lhs);
 	gen_expr(node->rhs);
 
@@ -479,6 +529,13 @@ gen_expr(Node *node)
 }
 
 static void
+gen_globaldec(Node *node)
+{
+	printf("@__gl_%.*s\n", node->len, node->loc);
+	printf("\tLIT %04d\n", node->val);
+}
+
+static void
 gen_fncall(Node *node)
 {
 	Node *cur = node->rhs;
@@ -492,6 +549,14 @@ gen_fncall(Node *node)
 }
 
 static void
+gen_globalget(Node *node)
+{
+	printf("\tLIT ,__gl_%.*s\n", node->len, node->loc);
+	printf("\tLDA\n");
+	depth += 1;
+}
+
+static void
 gen_function(Node *node)
 {
 	printf("@__fn_%.*s\n", node->lhs->len, node->lhs->loc);
@@ -509,6 +574,12 @@ gen_function(Node *node)
 			printf("\tRET\n");
 			depth -= 1;
 			break;
+		case NOD_ASSIGN_STMT:
+			gen_expr(node->rhs);
+			printf("\tLIT ,__gl_%.*s\n\tSTA\n",
+			       node->lhs->len, node->lhs->loc);
+			depth -= 1;
+			break;
 		default:
 			error("unexpected %d", node->type);
 		}
@@ -522,7 +593,10 @@ static void
 codegen(Node *node)
 {
 	while (node != NULL) {
-		gen_function(node);
+		if (node->type == NOD_GLOBAL)
+			gen_globaldec(node);
+		else
+			gen_function(node);
 		node = node->next;
 	}
 }
@@ -533,8 +607,14 @@ parse(Token *tok)
 {
 	Node head = {0};
 	Node *cur = &head;
-	while (tok->type != TOK_EOF)
+	while (tok->type != TOK_EOF) {
+		if (equal(tok, "global")) {
+			cur = cur->next = global(&tok, tok);
+			continue;
+		}
+
 		cur = cur->next = function(&tok, tok);
+	}
 	return head.next;
 }
 
diff --git a/testing.sh b/testing.sh
index d579990..e846bde 100755
--- a/testing.sh
+++ b/testing.sh
@@ -1,18 +1,23 @@
 #!/bin/sh
 
 function test() {
-	CODE="$1"
+	QUIET="$1"
+	CODE="$2"
 	echo "--- $CODE ---"
 	./build/golem "$CODE" >"build/tmp.orgaasm"
-	cat "build/tmp.orgaasm"
+	[ "$QUIET" != "-q" ] && cat "build/tmp.orgaasm"
 	orgaasm "build/tmp.orgaasm" "build/tmp.rom"
 	orgaemu "build/tmp.rom"
-	echo ""
+	[ "$QUIET" != "-q" ] && echo ""
 }
 
 tup || exit 1
-test "main(){5 + 2; return 4;}"
-test "main(){6 + 3;}"
-test "main(){'a' - 'b';}"
-test "main(){ fizz(50 + buzz() - 3) * 4; } fizz() { return 3; } buzz() { return 42; }"
+test "$1" "main(){5 + 2; return 4;}"
+test "$1" "main(){6 + 3;}"
+test "$1" "main(){'a' - 'b';}"
+test "$1" "main(){ fizz(50 + buzz() - 3) * 4; } fizz() { return 3; } buzz() { return 42; }"
+test "$1" "global abc; main(){ return abc; }"
+test "$1" "global abc = 5; main(){ return abc; }"
+test "$1" "main(){ return abc; } global abc = 5;"
+test "$1" "global abc = 5; main(){ inc(); return abc; } inc() { abc = abc + 1; }"
 rm -f build/tmp.*