foo.c: In function ‘main’:
foo.c:7:9: warning: ‘gets’ is deprecated [-Wdeprecated-declarations]
    7 |         gets(str);
      |         ^~~~
In file included from foo.c:1:
/nix/glibc-2.39-52-dev/include/stdio.h:667:14: note: declared here
  667 | extern char *gets (char *__s) __wur __attribute_deprecated__;
      |              ^~~~
/nix/binutils-2.42/bin/ld: /tmp/ccItERtn.o: in function `main':
foo.c:(.text.startup+0xa): warning: the `gets' function is dangerous and should not be used.