src/test/mir-opt/loop_test.rs

   1 // Copyright 2018 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 // compile-flags: -Z identify_regions -Z emit-end-regions
  12
  13 // Tests to make sure we correctly generate falseUnwind edges in loops
  14
  15 fn main() {
  16     // Exit early at runtime. Since only care about the generated MIR
  17     // and not the runtime behavior (which is exercised by other tests)
  18     // we just bail early. Without this the test just loops infinitely.
  19     if true {
  20         return;
  21     }
  22     loop {
  23         let x = 1;
  24         continue;
  25     }
  26 }
  27
  28 // END RUST SOURCE
  29 // START rustc.main.SimplifyCfg-qualify-consts.after.mir
  30 //    ...
  31 //    bb1: { // The cleanup block
  32 //        resume;
  33 //    }
  34 //    ...
  35 //    bb3: { // Entry into the loop
  36 //        _1 = ();
  37 //        goto -> bb4;
  38 //    }
  39 //    bb4: { // The loop_block
  40 //        falseUnwind -> [real: bb5, cleanup: bb1];
  41 //    }
  42 //    bb5: { // The loop body (body_block)
  43 //        StorageLive(_5);
  44 //        _5 = const 1i32;
  45 //        StorageDead(_5);
  46 //        goto -> bb4;
  47 //    }
  48 //    ...
  49 // END rustc.main.SimplifyCfg-qualify-consts.after.mir