Add goto and labeled statement

chibi.h

@@ -123,6 +123,8 @@ typedef enum {
   ND_BLOCK,      // { ... }
   ND_BREAK,      // "break"
   ND_CONTINUE,   // "continue"
+  ND_GOTO,       // "goto"
+  ND_LABEL,      // Labeled statement
   ND_FUNCALL,    // Function call
   ND_EXPR_STMT,  // Expression statement
   ND_STMT_EXPR,  // Statement expression
@@ -160,6 +162,9 @@ struct Node {
   char *funcname;
   Node *args;
 
+  // Goto or labeled statement
+  char *label_name;
+
   Var *var;      // Used if kind == ND_VAR
   long val;      // Used if kind == ND_NUM
 };

codegen.c

@@ -401,6 +401,13 @@ static void gen(Node *node) {
       error_tok(node->tok, "stray continue");
     printf("  jmp .L.continue.%d\n", contseq);
     return;
+  case ND_GOTO:
+    printf("  jmp .L.label.%s.%s\n", funcname, node->label_name);
+    return;
+  case ND_LABEL:
+    printf(".L.label.%s.%s:\n", funcname, node->label_name);
+    gen(node->lhs);
+    return;
   case ND_FUNCALL: {
     int nargs = 0;
     for (Node *arg = node->args; arg; arg = arg->next) {

parse.c

@@ -719,6 +719,8 @@ static Node *stmt(void) {
 //       | "{" stmt* "}"
 //       | "break" ";"
 //       | "continue" ";"
+//       | "goto" ident ";"
+//       | ident ":" stmt
 //       | declaration
 //       | expr ";"
 static Node *stmt2(void) {
@@ -802,6 +804,22 @@ static Node *stmt2(void) {
     return new_node(ND_CONTINUE, tok);
   }
 
+  if (tok = consume("goto")) {
+    Node *node = new_node(ND_GOTO, tok);
+    node->label_name = expect_ident();
+    expect(";");
+    return node;
+  }
+
+  if (tok = consume_ident()) {
+    if (consume(":")) {
+      Node *node = new_unary(ND_LABEL, stmt(), tok);
+      node->label_name = strndup(tok->str, tok->len);
+      return node;
+    }
+    token = tok;
+  }
+
   if (is_typename())
     return declaration();
 

tests

@@ -438,6 +438,10 @@ int main() {
   assert(5, ({ int i=0; int j=0; while (i++<10) { if (i>5) continue; j++; } j; }), "int i=0; int j=0; while (i++<10) { if (i>5) continue; j++; } j;");
   assert(11, ({ int i=0; int j=0; while(!i) { while (j++!=10) continue; break; } j; }), "int i=0; int j=0; while(!i) { while (j++!=10) continue; break; } j;");
 
+  assert(3, ({ int i=0; goto a; a: i++; b: i++; c: i++; i; }), "int i=0; goto a; a: i++; b: i++; c: i++; i;");
+  assert(2, ({ int i=0; goto e; d: i++; e: i++; f: i++; i; }), "int i=0; goto d; d: i++; e: i++; f: i++; i;");
+  assert(1, ({ int i=0; goto i; g: i++; h: i++; i: i++; i; }), "int i=0; goto g; h: i++; i: i++; j: i++; i;");
+
   printf("OK\n");
   return 0;
 }

tokenize.c

@@ -150,7 +150,7 @@ static char *starts_with_reserved(char *p) {
   static char *kw[] = {"return", "if", "else", "while", "for", "int",
                        "char", "sizeof", "struct", "typedef", "short",
                        "long", "void", "_Bool", "enum", "static", "break",
-                       "continue"};
+                       "continue", "goto"};
 
   for (int i = 0; i < sizeof(kw) / sizeof(*kw); i++) {
     int len = strlen(kw[i]);