Add line and block comments

test.sh

@@ -213,4 +213,8 @@ assert 1 'int main() { ({ 0; return 1; 2; }); return 3; }'
 assert 6 'int main() { return ({ 1; }) + ({ 2; }) + ({ 3; }); }'
 assert 3 'int main() { return ({ int x=3; x; }); }'
 
+assert 2 'int main() { /* return 1; */ return 2; }'
+assert 2 'int main() { // return 1;
+return 2; }'
+
 echo OK

tokenize.c

@@ -230,6 +230,23 @@ static Token *tokenize(char *filename, char *p) {
   Token *cur = &head;
 
   while (*p) {
+    // Skip line comments.
+    if (startswith(p, "//")) {
+      p += 2;
+      while (*p != '\n')
+        p++;
+      continue;
+    }
+
+    // Skip block comments.
+    if (startswith(p, "/*")) {
+      char *q = strstr(p + 2, "*/");
+      if (!q)
+        error_at(p, "unclosed block comment");
+      p = q + 2;
+      continue;
+    }
+
     // Skip whitespace characters.
     if (isspace(*p)) {
       p++;