feat: define variables with type

50cc.h

@@ -15,6 +15,7 @@ typedef enum {
   TK_ELSE,
   TK_WHILE,
   TK_FOR,
+  TK_TYPE,
   TK_EOF
 } TokenKind;
 
@@ -40,6 +41,7 @@ bool consume_if();
 bool consume_else();
 bool consume_while();
 bool consume_for();
+bool consume_type();
 void expect(char *op);
 int expect_number();
 bool at_eof();
@@ -101,6 +103,7 @@ Node *add();
 Node *mul();
 Node *unary();
 Node *primary();
+Node * define_variable();
 Node *variable();
 
 Node *new_node(NodeKind kind, Node *lhs, Node *rhs);

parser.c

@@ -64,6 +64,12 @@ bool consume_for() {
   return true;
 }
 
+bool consume_type() {
+  if (token->kind != TK_TYPE) return false;
+  token = token->next;
+  return true;
+}
+
 void expect(char *op) {
   if (token->kind != TK_RESERVED || strlen(op) != token->len ||
       memcmp(token->str, op, token->len))
@@ -201,10 +207,17 @@ Node *stmt() {
 
   if (consume_return()) {
     node = new_node(ND_RETURN, expr(), NULL);
-  } else {
-    node = expr();
+    expect(";");
+    return node;
   }
 
+  if (consume_type()) {
+    Token *tok = consume_ident();
+    node = define_variable(tok);
+    expect(";");
+    return node;
+  }
+  node = expr();
   expect(";");
   return node;
 }
@@ -311,25 +324,40 @@ Node *primary() {
   return new_node_num(expect_number());
 }
 
-Node *variable(Token *tok) {
+Node *define_variable(Token *tok) {
   Node *node = calloc(1, sizeof(Node));
   node->kind = ND_LVAR;
 
   LVar *lvar = find_lvar(tok);
-  if (lvar) {
-    node->offset = lvar->offset;
+  if (lvar != NULL) {
+    char *name = calloc(1, tok->len + 1);
+    memcpy(name, tok->str, tok->len);
+    error("duplicated variable: %s\n", name);
+  }
+  lvar = calloc(1, sizeof(LVar));
+  lvar->next = locals[cur_func];
+  lvar->name = tok->str;
+  lvar->len = tok->len;
+  if (locals[cur_func] == NULL) {
+    lvar->offset = 8;
   } else {
-    lvar = calloc(1, sizeof(LVar));
-    lvar->next = locals[cur_func];
-    lvar->name = tok->str;
-    lvar->len = tok->len;
-    if (locals[cur_func] == NULL) {
-      lvar->offset = 8;
-    } else {
-      lvar->offset = locals[cur_func]->offset + 8;
-    }
-    node->offset = lvar->offset;
-    locals[cur_func] = lvar;
+    lvar->offset = locals[cur_func]->offset + 8;
+  }
+  node->offset = lvar->offset;
+  locals[cur_func] = lvar;
+
+  return node;
+}
+
+Node *variable(Token *tok) {
+  Node *node = calloc(1, sizeof(Node));
+  node->kind = ND_LVAR;
+  LVar *lvar = find_lvar(tok);
+  if (lvar == NULL) {
+    char *name = calloc(1, tok->len + 1);
+    memcpy(name, tok->str, tok->len);
+    error("undefined variable: %s\n", name);
   }
+  node->offset = lvar->offset;
   return node;
 }

test.sh

@@ -20,39 +20,22 @@ assert(){
     fi
 }
 
-# assert 2 "main () { return 2;}"
-# assert 3 "
-# main() return func(1, 2);
-# func(a, b) { return a + b; }
-# "
-
-# assert 4 "
-# main() return func(1, 2, 3);
-# func(a, b, c) { return a + c; }
-# "
-
-# assert 3 "main() {
-#   a = 4;
-#   return fib(a);
-# }
-# fib(n){
-#   if(n == 0) return 0;
-#   if(n == 1) return 1;
-#   return  fib(n - 1)+ fib(n -2);
-# }
-# "
-
-assert 4 "main(){x = 4;
-y = &x;
-return *y;
+# define variables with type "int"
+assert 5 "main() {
+  int x;
+  x = 5;
+  return x;
 }"
-# assert 42 "42;"
-# assert 21 "5+20-4;"
-# assert 2 " 5 - 3; "
-# assert 47 "5+6*7;"
-# assert 15 "5*(9-6);"
-# assert 4 "(3+5)/2;"
-# assert 10 "-10+20;"
+
+# basic test case
+assert 2 "main () { return 2;}"
+assert 42 "main()return 42;"
+assert 21 "main(){return 5+20-4;}"
+assert 2 "main(){return 5 - 3;}"
+assert 47 "main(){return 5+6*7;}"
+assert 15 "main(){return 5*(9-6);}"
+assert 4 "main(){ return (3+5)/2;}"
+assert 10 "main(){ return -10+20;}"
 
 # assert 0 "0==1;"
 # assert 1 "42==42;"
@@ -87,6 +70,31 @@ return *y;
 # else return 6;
 # return 2;
 # "
+# assert 3 "
+# main() return func(1, 2);
+# func(a, b) { return a + b; }
+# "
+
+# assert 4 "
+# main() return func(1, 2, 3);
+# func(a, b, c) { return a + c; }
+# "
+
+# assert 3 "main() {
+#   a = 4;
+#   return fib(a);
+# }
+# fib(n){
+#   if(n == 0) return 0;
+#   if(n == 1) return 1;
+#   return  fib(n - 1)+ fib(n -2);
+# }
+# "
+
+# assert 4 "main(){x = 4;
+# y = &x;
+# return *y;
+# }"
 
 # assert 10 "i = 0;
 # while (i < 10) i = i + 1;

tokenize.c

@@ -75,6 +75,12 @@ Token *tokenize() {
       continue;
     }
 
+    if (startswith(p, "int") && !isalnum(p[3])) {
+      cur = new_token(TK_TYPE, cur, p, 3);
+      p += 3;
+      continue;
+    }
+
     if ('a' <= *p && *p <= 'z') {
       char *c = p;
       while ('a' <= *c && *c <= 'z') {