feat: impl ptr type

50cc.h

@@ -90,6 +90,12 @@ struct Node {
   int offset;
 };
 
+typedef struct Type Type;
+struct Type {
+  enum { INT, PTR } ty;
+  struct Type *ptr_to;
+};
+
 extern Node *code[];
 
 void program();
@@ -103,7 +109,7 @@ Node *add();
 Node *mul();
 Node *unary();
 Node *primary();
-Node * define_variable();
+Node *define_variable();
 Node *variable();
 
 Node *new_node(NodeKind kind, Node *lhs, Node *rhs);
@@ -119,6 +125,7 @@ struct LVar {
   char *name;
   int len;
   int offset;
+  Type *type;
 };
 
 extern LVar *locals[];

codegen.c

@@ -1,6 +1,10 @@
 #include "50cc.h"
 
 void gen_lval(Node *node) {
+  if (node->kind == ND_DEREF) {
+    gen(node->lhs);
+    return;
+  }
   if (node->kind != ND_LVAR) error("代入の左辺値が変数ではありません");
   printf("  mov rax, rbp\n");
   printf("  sub rax, %d\n", node->offset);

parser.c

@@ -113,6 +113,7 @@ Node *func() {
     error("type is not found");
   }
   Token *tok = consume_ident();
+
   if (tok == NULL) {
     error("there is no function");
   }
@@ -127,10 +128,9 @@ Node *func() {
     if (!consume_type()) {
       error("type of args is not found");
     }
-    Token *tok = consume_ident();
-    if (tok != NULL) {
-      node->args[i] = define_variable(tok);
-    }
+
+    node->args[i] = define_variable();
+
     if (consume(")")) {
       break;
     }
@@ -218,8 +218,7 @@ Node *stmt() {
   }
 
   if (consume_type()) {
-    Token *tok = consume_ident();
-    node = define_variable(tok);
+    node = define_variable();
     expect(";");
     return node;
   }
@@ -330,7 +329,22 @@ Node *primary() {
   return new_node_num(expect_number());
 }
 
-Node *define_variable(Token *tok) {
+Node *define_variable() {
+  Type *type;
+  type = calloc(1, sizeof(Type));
+  type->ty = INT;
+  type->ptr_to = NULL;
+  while (consume("*")) {
+    Type *ptr_type;
+    ptr_type = calloc(1, sizeof(Type));
+    ptr_type->ty = PTR;
+    ptr_type->ptr_to = type;
+    type = ptr_type;
+  }
+  Token *tok = consume_ident();
+  if (tok == NULL) {
+    error("invalid variable");
+  }
   Node *node = calloc(1, sizeof(Node));
   node->kind = ND_LVAR;
 
@@ -349,6 +363,7 @@ Node *define_variable(Token *tok) {
   } else {
     lvar->offset = locals[cur_func]->offset + 8;
   }
+  lvar->type = type;
   node->offset = lvar->offset;
   locals[cur_func] = lvar;
 

test.sh

@@ -20,25 +20,37 @@ assert(){
     fi
 }
 
-# define variables with type "int"
-assert 5 "int main() {
+# pointer
+assert 3 "
+int main(){
   int x;
-  x = 5;
+  int *y;
+  y = &x;
+  *y = 3;
   return x;
-}"
-
-assert 3 "int main() {
-  int a;
-  a = 4;
-  return fib(a);
-}
-int fib(int n){
-  if(n == 0) return 0;
-  if(n == 1) return 1;
-  return  fib(n - 1)+ fib(n -2);
 }
 "
 
+
+# define variables with type "int"
+# assert 5 "int main() {
+#   int x;
+#   x = 5;
+#   return x;
+# }"
+
+# assert 3 "int main() {
+#   int a;
+#   a = 4;
+#   return fib(a);
+# }
+# int fib(int n){
+#   if(n == 0) return 0;
+#   if(n == 1) return 1;
+#   return  fib(n - 1)+ fib(n -2);
+# }
+# "
+
 # basic test case
 # assert 2 "main(){return 2;}"
 # assert 42 "main()return 42;"