src/test/ui/lint/unused/unused-macro-rules.rs

   1 #![deny(unused_macro_rules)]
   2 // To make sure we are not hitting this
   3 #![deny(unused_macros)]
   4
   5 // Most simple case
   6 macro_rules! num {
   7     (one) => { 1 };
   8     (two) => { 2 }; //~ ERROR: 2nd rule of macro
   9     (three) => { 3 };
  10     (four) => { 4 }; //~ ERROR: 4th rule of macro
  11 }
  12 const _NUM: u8 = num!(one) + num!(three);
  13
  14 // Check that allowing the lint works
  15 #[allow(unused_macro_rules)]
  16 macro_rules! num_allowed {
  17     (one) => { 1 };
  18     (two) => { 2 };
  19     (three) => { 3 };
  20     (four) => { 4 };
  21 }
  22 const _NUM_ALLOWED: u8 = num_allowed!(one) + num_allowed!(three);
  23
  24 // Check that macro calls inside the macro trigger as usage
  25 macro_rules! num_rec {
  26     (one) => { 1 };
  27     (two) => {
  28         num_rec!(one) + num_rec!(one)
  29     };
  30     (three) => { //~ ERROR: 3rd rule of macro
  31         num_rec!(one) + num_rec!(two)
  32     };
  33     (four) => { num_rec!(two) + num_rec!(two) };
  34 }
  35 const _NUM_RECURSIVE: u8 = num_rec!(four);
  36
  37 // No error if the macro is being exported
  38 #[macro_export]
  39 macro_rules! num_exported {
  40     (one) => { 1 };
  41     (two) => { 2 };
  42     (three) => { 3 };
  43     (four) => { 4 };
  44 }
  45 const _NUM_EXPORTED: u8 = num_exported!(one) + num_exported!(three);
  46
  47 fn main() {}