tests/ui/hygiene/wrap_unhygienic_example.rs

   1 // check-pass
   2 // ignore-pretty pretty-printing is unhygienic
   3
   4 // aux-build:my_crate.rs
   5 // aux-build:unhygienic_example.rs
   6
   7 #![feature(decl_macro)]
   8
   9 extern crate unhygienic_example;
  10 extern crate my_crate; // (b)
  11
  12 // Hygienic version of `unhygienic_macro`.
  13 pub macro hygienic_macro() {
  14     fn g() {} // (c)
  15     ::unhygienic_example::unhygienic_macro!();
  16     // ^ Even though we invoke an unhygienic macro, `hygienic_macro` remains hygienic.
  17     // In the above expansion:
  18     // (1) `my_crate` always resolves to (b) regardless of invocation site.
  19     // (2) The defined function `f` is only usable inside this macro definition.
  20     // (3) `g` always resolves to (c) regardless of invocation site.
  21     // (4) `$crate::g` remains hygienic and continues to resolve to (a).
  22
  23     f();
  24 }
  25
  26 #[allow(unused)]
  27 fn test_hygienic_macro() {
  28     hygienic_macro!();
  29
  30     fn f() {} // (d) no conflict
  31     f(); // resolves to (d)
  32 }
  33
  34 fn main() {}