CTFE: LongRunningWarn is getting implicitly deduplicated #118612
Description
I tried the following code:
#![allow(long_running_const_eval)] const FOO: () = loop {}; fn main() { FOO }output after running for a very long time:
warning: constant evaluation is taking a long time --> src/main.rs:2:17 | 2 | const FOO: () = loop {}; | ^^^^^^^ the const evaluator is currently interpreting this expression | help: the constant being evaluated --> src/main.rs:2:1 | 2 | const FOO: () = loop {}; | ^^^^^^^^^^^^^ modify rustc as follows results in the following output:
diff --git a/compiler/rustc_const_eval/src/const_eval/machine.rs b/compiler/rustc_const_eval/src/const_eval/machine.rs index 2d8ca67c3a5..1bf7949725b 100644 --- a/compiler/rustc_const_eval/src/const_eval/machine.rs +++ b/compiler/rustc_const_eval/src/const_eval/machine.rs @@ -593,6 +593,9 @@ fn increment_const_eval_counter(ecx: &mut InterpCx<'mir, 'tcx, Self>) -> InterpR }; ecx.machine.num_evaluated_steps = new_steps; + if new_steps.is_power_of_two() { + eprintln!("power of two : {new_steps}"); + } // By default, we have a *deny* lint kicking in after some time // to ensure `loop {}` doesn't just go forever. // In case that lint got reduced, in particular for `--cap-lint` situations, we also Compiling test1 v0.1.0 (/home/lcnr/test1) power of two : 1 power of two : 2 power of two : 4 power of two : 8 power of two : 16 power of two : 32 power of two : 64 power of two : 128 power of two : 256 power of two : 512 power of two : 1024 power of two : 2048 power of two : 4096 power of two : 8192 power of two : 16384 power of two : 32768 power of two : 65536 power of two : 131072 power of two : 262144 power of two : 524288 power of two : 1048576 power of two : 2097152 power of two : 4194304 warning: constant evaluation is taking a long time --> src/main.rs:2:17 | 2 | const FOO: () = loop {}; | ^^^^^^^ the const evaluator is currently interpreting this expression | help: the constant being evaluated --> src/main.rs:2:1 | 2 | const FOO: () = loop {}; | ^^^^^^^^^^^^^ power of two : 8388608 power of two : 16777216 power of two : 33554432 power of two : 67108864 power of two : 134217728 changing the invocation to cargo rustc -- -Zdeduplicate-diagnostics=no actually prints the warning at each power of two of steps.
This warning should not be affected by deduplicate-diagnostics. It's whole point is to be repeated multiple times.