Commit Graph

5774 Commits

Author SHA1 Message Date
Ralf Jung
b87a9c90e1 fix handling of NaNs in simd max/min 2022-03-07 09:49:35 -05:00
Ralf Jung
2f97eb68a0 implement simd_fmax/fmin 2022-03-07 09:40:23 -05:00
Ralf Jung
9851b743c1 implement simd_reduce_min/max 2022-03-07 09:40:23 -05:00
Ralf Jung
db06d4998f implement simd_cast, simd_as 2022-03-07 09:40:23 -05:00
Ralf Jung
594a70a289 rustup 2022-03-07 09:39:32 -05:00
bors
a25d905ddf Auto merge of #2003 - RalfJung:simd-reduce-test, r=RalfJung
also test f32/f64 simd_reduce

Forgot to include this in https://github.com/rust-lang/miri/pull/2001
2022-03-06 04:22:12 +00:00
Ralf Jung
21d36ffd04 also test f32/f64 simd_reduce 2022-03-05 23:03:14 -05:00
bors
176f070d4c Auto merge of #2002 - RalfJung:negative-shifts, r=RalfJung
add extra tests for shifts with negative offsets

Cc https://github.com/rust-lang/rust/pull/94659
2022-03-06 04:00:41 +00:00
Ralf Jung
9810a147a7 add extra tests for shifts with negative offsets 2022-03-05 22:59:23 -05:00
bors
54b14b7f01 Auto merge of #2001 - RalfJung:simd, r=RalfJung
add more simd_reduce intrinsics

This makes large parts of the portable-simd test suite work. :D
Cc https://github.com/rust-lang/portable-simd/pull/255
2022-03-06 00:25:19 +00:00
Ralf Jung
b491b72673 implement simd_reduce_{add,mul} 2022-03-05 19:02:00 -05:00
Ralf Jung
3ed8ad4423 avoid repeated string matching, and add more simd_reduce intrinsics 2022-03-05 18:46:14 -05:00
bors
3854a76ace Auto merge of #1970 - asquared31415:open_unix_varargs, r=RalfJung
Allow varargs for libc::open when it is allowed by the second argument

This PR allows `libc::open` to be called using two or three arguments as defined in https://man7.org/linux/man-pages/man2/open.2.html

The presence of the third argument depends on the value of the second argument.  If the second argument dictates that the third argument is *required* miri will emit an error if the argument is missing.  If the second argument does *not* require a third argument, then the argument is ignored and passed as 0 internally (it would be ignored by libc anyway)
2022-03-05 22:47:51 +00:00
asquared31415
8e97599af4 allow varargs for libc::open when it is allowed by the second argument 2022-03-05 17:29:48 -05:00
bors
2c1b9ce348 Auto merge of #1998 - RalfJung:rustup, r=RalfJung
rustup

Adjusts our tests for https://github.com/rust-lang/rust/pull/92697
2022-03-05 22:26:57 +00:00
Ralf Jung
ec0e513c64 rustup 2022-03-05 17:26:32 -05:00
bors
926af6493b Auto merge of #1999 - RalfJung:forward-env, r=oli-obk
add flag to forward specific env vars (while isolation remains enabled)

The flag is called `-Zmiri-env-forward=<var>`, but I am open to bikeshedding. ;)
2022-03-05 19:36:10 +00:00
bors
0242acc786 Auto merge of #2000 - RalfJung:simd, r=RalfJung
implement missing SIMD comparison operators, simd_xor, and simd_reduce_all
2022-03-05 18:47:28 +00:00
Ralf Jung
90207a5484 implement missing SIMD comparison operators, simd_xor, and simd_reduce_all 2022-03-05 13:45:13 -05:00
Ralf Jung
ceec2b3ceb avoid env var forwarding logic panicking for non-UTF-8 env vars 2022-03-05 11:14:37 -05:00
Ralf Jung
3adc203c1c add flag to forward specific env vars (while isolation remains enabled) 2022-03-05 11:14:37 -05:00
bors
a715171534 Auto merge of #1997 - RalfJung:simd, r=RalfJung
implement simd_neg and simd_fabs

This lets us run the puny portable-simd smoke test in the core test suite. ;)
2022-03-03 20:08:02 +00:00
Ralf Jung
0d4902f12f implement simd_neg and simd_fabs 2022-03-03 14:54:54 -05:00
Ralf Jung
0147b88ce5 use binary_op over overflowing_binary_op 2022-03-03 14:44:50 -05:00
bors
80c3f424b9 Auto merge of #1995 - saethlin:trophies, r=RalfJung
rkyv deallocation alignment issue
2022-03-03 18:57:56 +00:00
Ben Kimock
0bd83245ed rkyv deallocation alignment issue 2022-03-03 13:10:05 -05:00
bors
2f9ecdeba4 Auto merge of #1992 - RalfJung:sdiv, r=RalfJung
adjust for div/rem overflow being UB

This is the Miri side of https://github.com/rust-lang/rust/pull/94512. Just some error messages change.
2022-03-03 17:32:59 +00:00
Ralf Jung
c0f7251055 add test for simd division overflow UB 2022-03-03 12:32:42 -05:00
Ralf Jung
d7c7fc0fa2 rustup 2022-03-03 12:26:42 -05:00
Ralf Jung
97ddcf1f6b adjust for div/rem overflow being UB 2022-03-03 12:14:24 -05:00
bors
2b23786c48 Auto merge of #1994 - RalfJung:unaligned-ptr-test, r=RalfJung
Make sure we notice when a u16 is loaded at offset 1 into a u8 allocation

Cc https://github.com/rust-lang/miri/pull/1990 which would have changed the integer address logic in a way that this bug could not be found any more.
2022-03-02 18:07:58 +00:00
Ralf Jung
798dc5a78a Make sure we notice when a u16 is loaded at offset 1 into a u8 allocation 2022-03-02 13:06:28 -05:00
bors
c6b3f687d5 Auto merge of #1991 - RalfJung:rustup, r=RalfJung
Rustup: simd_select

Cc https://github.com/rust-lang/rust/issues/94474
2022-03-01 23:47:10 +00:00
Ralf Jung
363236e2d4 test overflowing Div/Rem 2022-03-01 18:44:37 -05:00
Ralf Jung
aa4f82ea48 implement simd_select 2022-03-01 18:40:40 -05:00
Ralf Jung
f672282bf2 factor SIMD bool handling into helper functions 2022-03-01 18:15:39 -05:00
bors
e05a543f74 Auto merge of #1985 - RalfJung:fn-ptr, r=RalfJung
update fn ptr tests

This adjusts the tests for https://github.com/rust-lang/rust/pull/94343.
2022-02-27 20:27:47 +00:00
Ralf Jung
c347b04e82 add test for rust issue 94371 2022-02-27 15:27:34 -05:00
Ralf Jung
71075672f5 rustup 2022-02-27 15:22:49 -05:00
bors
b490e6b01b Auto merge of #1989 - saethlin:short-backtraces, r=RalfJung
Only print the pruning note if the trace was definitely pruned

Per https://github.com/rust-lang/miri/pull/1987#discussion_r815337994

The only problem with this is that it looks like we can't emit the note about `-Zmiri-backtrace=full` if we also emit a tag-tracking diagnostic. The final note about the setting simply doesn't appear on the final error if it is printed before. I feel like we're running up against some diagnostic deduplication logic?
2022-02-26 22:17:04 +00:00
Ben Kimock
f1c649890b Only print the pruning note if the trace was definitely pruned 2022-02-26 17:02:17 -05:00
bors
144d56532c Auto merge of #1987 - saethlin:short-backtraces, r=oli-obk
Prune stacktraces for tag-tracking diagnostics too

In https://github.com/rust-lang/miri/pull/1977 we forgot to use the pruning logic when printing tag-tracking messages. I just saw this output before this PR which is very silly:
```
test sanity ... note: tracking was triggered
   --> src/lib.rs:110:21
    |
110 |         unsafe { &*(&self.value[range] as *const [T] as *const Aligned<A, [T]>) }
    |                     ^^^^^^^^^^^^^^^^^^ created tag 160954
    |
    = note: inside `<Aligned<A4, [u8]> as std::ops::Index<std::ops::RangeTo<usize>>>::index` at src/lib.rs:110:21
note: inside `sanity` at src/lib.rs:261:30
   --> src/lib.rs:261:30
    |
261 |     let y: &Aligned<_, _> = &y[..2];
    |                              ^^^^^^
note: inside closure at src/lib.rs:229:1
   --> src/lib.rs:229:1
    |
228 |   #[test]
    |   ------- in this procedural macro expansion
229 | / fn sanity() {
230 | |     use core::mem;
231 | |
232 | |     let x: Aligned<A2, _> = Aligned([0u8; 3]);
...   |
284 | |     let _: &[u8] = y;
285 | | }
    | |_^
    = note: inside `<[closure@src/lib.rs:229:1: 285:2] as std::ops::FnOnce<()>>::call_once - shim` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/core/src/ops/function.rs:227:5
    = note: inside `<fn() as std::ops::FnOnce<()>>::call_once - shim(fn())` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/core/src/ops/function.rs:227:5
    = note: inside `test::__rust_begin_short_backtrace::<fn()>` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/test/src/lib.rs:575:5
    = note: inside closure at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/test/src/lib.rs:566:30
    = note: inside `<[closure@test::run_test::{closure#1}] as std::ops::FnOnce<()>>::call_once - shim(vtable)` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/core/src/ops/function.rs:227:5
    = note: inside `<std::boxed::Box<dyn std::ops::FnOnce() + std::marker::Send> as std::ops::FnOnce<()>>::call_once` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/alloc/src/boxed.rs:1854:9
    = note: inside `<std::panic::AssertUnwindSafe<std::boxed::Box<dyn std::ops::FnOnce() + std::marker::Send>> as std::ops::FnOnce<()>>::call_once` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/core/src/panic/unwind_safe.rs:271:9
    = note: inside `std::panicking::r#try::do_call::<std::panic::AssertUnwindSafe<std::boxed::Box<dyn std::ops::FnOnce() + std::marker::Send>>, ()>` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/panicking.rs:492:40
    = note: inside `std::panicking::r#try::<(), std::panic::AssertUnwindSafe<std::boxed::Box<dyn std::ops::FnOnce() + std::marker::Send>>>` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/panicking.rs:456:19
    = note: inside `std::panic::catch_unwind::<std::panic::AssertUnwindSafe<std::boxed::Box<dyn std::ops::FnOnce() + std::marker::Send>>, ()>` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/panic.rs:137:14
    = note: inside `test::run_test_in_process` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/test/src/lib.rs:598:18
    = note: inside closure at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/test/src/lib.rs:492:39
    = note: inside `test::run_test::run_test_inner` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/test/src/lib.rs:530:13
    = note: inside `test::run_test` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/test/src/lib.rs:562:28
    = note: inside `test::run_tests::<[closure@test::run_tests_console::{closure#2}]>` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/test/src/lib.rs:305:17
    = note: inside `test::run_tests_console` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/test/src/console.rs:286:5
    = note: inside `test::test_main` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/test/src/lib.rs:116:15
    = note: inside `test::test_main_static` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/test/src/lib.rs:135:5
    = note: inside `main`
    = note: inside `<fn() as std::ops::FnOnce<()>>::call_once - shim(fn())` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/core/src/ops/function.rs:227:5
    = note: inside `std::sys_common::backtrace::__rust_begin_short_backtrace::<fn(), ()>` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/sys_common/backtrace.rs:122:18
    = note: inside closure at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/rt.rs:145:18
    = note: inside `std::ops::function::impls::<impl std::ops::FnOnce<()> for &dyn std::ops::Fn() -> i32 + std::marker::Sync + std::panic::RefUnwindSafe>::call_once` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/core/src/ops/function.rs:259:13
    = note: inside `std::panicking::r#try::do_call::<&dyn std::ops::Fn() -> i32 + std::marker::Sync + std::panic::RefUnwindSafe, i32>` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/panicking.rs:492:40
    = note: inside `std::panicking::r#try::<i32, &dyn std::ops::Fn() -> i32 + std::marker::Sync + std::panic::RefUnwindSafe>` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/panicking.rs:456:19
    = note: inside `std::panic::catch_unwind::<&dyn std::ops::Fn() -> i32 + std::marker::Sync + std::panic::RefUnwindSafe, i32>` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/panic.rs:137:14
    = note: inside closure at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/rt.rs:128:48
    = note: inside `std::panicking::r#try::do_call::<[closure@std::rt::lang_start_internal::{closure#2}], isize>` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/panicking.rs:492:40
    = note: inside `std::panicking::r#try::<isize, [closure@std::rt::lang_start_internal::{closure#2}]>` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/panicking.rs:456:19
    = note: inside `std::panic::catch_unwind::<[closure@std::rt::lang_start_internal::{closure#2}], isize>` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/panic.rs:137:14
    = note: inside `std::rt::lang_start_internal` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/rt.rs:128:20
    = note: inside `std::rt::lang_start::<()>` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/rt.rs:144:17
    = note: this note originates in the attribute macro `test` (in Nightly builds, run with -Z macro-backtrace for more info)

error: Undefined Behavior: trying to reborrow for SharedReadOnly at alloc61593+0x2, but parent tag <160954> does not have an appropriate item in the borrow stack
   --> src/lib.rs:261:30
    |
261 |     let y: &Aligned<_, _> = &y[..2];
    |                              ^^^^^^ trying to reborrow for SharedReadOnly at alloc61593+0x2, but parent tag <160954> does not have an appropriate item in the borrow stack
    |
    = help: this indicates a potential bug in the program: it performed an invalid operation, but the rules it violated are still experimental
    = help: see https://github.com/rust-lang/unsafe-code-guidelines/blob/master/wip/stacked-borrows.md for further information

    = note: inside `sanity` at src/lib.rs:261:30
note: inside closure at src/lib.rs:229:1
   --> src/lib.rs:229:1
    |
228 |   #[test]
    |   ------- in this procedural macro expansion
229 | / fn sanity() {
230 | |     use core::mem;
231 | |
232 | |     let x: Aligned<A2, _> = Aligned([0u8; 3]);
...   |
284 | |     let _: &[u8] = y;
285 | | }
    | |_^
    = note: this error originates in the attribute macro `test` (in Nightly builds, run with -Z macro-backtrace for more info)

note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace

error: aborting due to previous error

error: test failed, to rerun pass '--lib'
```
2022-02-26 08:56:02 +00:00
Ben Kimock
d2bb231954 Prune stacktraces for tag-tracking diagnostics too 2022-02-25 19:18:05 -05:00
Ralf Jung
e9b140b4a5 update fn ptr tests 2022-02-25 12:06:10 -05:00
Ralf Jung
ddd3e3c4e0 rustup 2022-02-25 12:05:59 -05:00
bors
538aedf099 Auto merge of #1984 - RalfJung:rustup, r=RalfJung
rustup
2022-02-24 15:57:56 +00:00
Ralf Jung
444396d620 rustup 2022-02-24 10:55:40 -05:00
bors
6a39eeb764 Auto merge of #1982 - saethlin:trophies, r=oli-obk
Add crossbeam-epoch and integer-encoding to the trophy case

What are the critera for adding SB entries to the trophy case?
2022-02-23 09:13:16 +00:00
Ben Kimock
a20d1f1889 Add crossbeam-epoch and integer-encoding to the trophy case 2022-02-22 21:09:30 -05:00
bors
c71006722e Auto merge of #1977 - saethlin:short-backtraces, r=RalfJung
Prune backtraces similar to RUST_BACKTRACE=1 logic

This removes the majority of output from `cargo miri run` and `cargo miri test` in common usage.

~~I've copied the logic almost directly from `std`:
3b186511f6/library/std/src/sys_common/backtrace.rs (L76-L77~~)

~~It might be nice to have the "some details were omitted" note and a fallback to a setting where we print everything just in case this logic goes sideways, but~~
~~1. I'm not sure where to put the note~~
~~2. `MIRI_BACKTRACE`, `RUST_BACKTRACE`, and `RUSTC_CTFE_BACKTRACE` already do something else. Should we repurpose or add on to the semantics of `MIRI_BACKTRACE`?~~

---
Based on this tiny silly crate:
```rust
fn main() {
    some_function();
}

fn some_function() {
    unsafe {
        let _x: &u8 = core::mem::transmute(1usize);
    }
}

#[cfg(test)]
mod tests {
    #[test]
    fn it_works() {
        unsafe {
            let _x: &'static u8 = core::mem::transmute(1usize);
        }
    }
}
```

`cargo miri run`:
Before:
```
    Finished dev [unoptimized + debuginfo] target(s) in 0.10s
     Running `/home/ben/.cargo/bin/cargo-miri target/miri/x86_64-unknown-linux-gnu/debug/scratch`
error: Undefined Behavior: type validation failed: encountered a dangling reference (address 0x1 is unallocated)
 --> src/main.rs:7:23
  |
7 |         let _x: &u8 = core::mem::transmute(1usize);
  |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered a dangling reference (address 0x1 is unallocated)
  |
  = help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior
  = help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information

  = note: inside `some_function` at src/main.rs:7:23
note: inside `main` at src/main.rs:2:5
 --> src/main.rs:2:5
  |
2 |     some_function();
  |     ^^^^^^^^^^^^^^^
  = note: inside `<fn() as std::ops::FnOnce<()>>::call_once - shim(fn())` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/core/src/ops/function.rs:227:5
  = note: inside `std::sys_common::backtrace::__rust_begin_short_backtrace::<fn(), ()>` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/sys_common/backtrace.rs:122:18
  = note: inside closure at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/rt.rs:145:18
  = note: inside `std::ops::function::impls::<impl std::ops::FnOnce<()> for &dyn std::ops::Fn() -> i32 + std::marker::Sync + std::panic::RefUnwindSafe>::call_once` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/core/src/ops/function.rs:259:13
  = note: inside `std::panicking::r#try::do_call::<&dyn std::ops::Fn() -> i32 + std::marker::Sync + std::panic::RefUnwindSafe, i32>` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/panicking.rs:492:40
  = note: inside `std::panicking::r#try::<i32, &dyn std::ops::Fn() -> i32 + std::marker::Sync + std::panic::RefUnwindSafe>` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/panicking.rs:456:19
  = note: inside `std::panic::catch_unwind::<&dyn std::ops::Fn() -> i32 + std::marker::Sync + std::panic::RefUnwindSafe, i32>` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/panic.rs:137:14
  = note: inside closure at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/rt.rs:128:48
  = note: inside `std::panicking::r#try::do_call::<[closure@std::rt::lang_start_internal::{closure#2}], isize>` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/panicking.rs:492:40
  = note: inside `std::panicking::r#try::<isize, [closure@std::rt::lang_start_internal::{closure#2}]>` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/panicking.rs:456:19
  = note: inside `std::panic::catch_unwind::<[closure@std::rt::lang_start_internal::{closure#2}], isize>` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/panic.rs:137:14
  = note: inside `std::rt::lang_start_internal` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/rt.rs:128:20
  = note: inside `std::rt::lang_start::<()>` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/rt.rs:144:17

error: aborting due to previous error

```
After:
```    Finished dev [unoptimized + debuginfo] target(s) in 0.10s
     Running `/home/ben/.cargo/bin/cargo-miri target/miri/x86_64-unknown-linux-gnu/debug/scratch`
error: Undefined Behavior: type validation failed: encountered a dangling reference (address 0x1 is unallocated)
 --> src/main.rs:7:23
  |
7 |         let _x: &u8 = core::mem::transmute(1usize);
  |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered a dangling reference (address 0x1 is unallocated)
  |
  = help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior
  = help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information

  = note: inside `some_function` at src/main.rs:7:23
note: inside `main` at src/main.rs:2:5
 --> src/main.rs:2:5
  |
2 |     some_function();
  |     ^^^^^^^^^^^^^^^

note: Some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace.

error: aborting due to previous error
```

`cargo miri test`
Before:
```
    Finished test [unoptimized + debuginfo] target(s) in 0.00s
     Running unittests (target/miri/x86_64-unknown-linux-gnu/debug/deps/scratch-9d7717efc37bb64c)

running 1 test
test tests::it_works ... error: Undefined Behavior: type validation failed: encountered a dangling reference (address 0x1 is unallocated)
  --> src/main.rs:16:35
   |
16 |             let _x: &'static u8 = core::mem::transmute(1usize);
   |                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered a dangling reference (address 0x1 is unallocated)
   |
   = help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior
   = help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information

   = note: inside `tests::it_works` at src/main.rs:16:35
note: inside closure at src/main.rs:14:5
  --> src/main.rs:14:5
   |
13 |       #[test]
   |       ------- in this procedural macro expansion
14 | /     fn it_works() {
15 | |         unsafe {
16 | |             let _x: &'static u8 = core::mem::transmute(1usize);
17 | |         }
18 | |     }
   | |_____^
   = note: inside `<[closure@src/main.rs:14:5: 18:6] as std::ops::FnOnce<()>>::call_once - shim` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/core/src/ops/function.rs:227:5
   = note: inside `<fn() as std::ops::FnOnce<()>>::call_once - shim(fn())` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/core/src/ops/function.rs:227:5
   = note: inside `tests::test::__rust_begin_short_backtrace::<fn()>` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/test/src/lib.rs:575:5
   = note: inside closure at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/test/src/lib.rs:566:30
   = note: inside `<[closure@tests::test::run_test::{closure#1}] as std::ops::FnOnce<()>>::call_once - shim(vtable)` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/core/src/ops/function.rs:227:5
   = note: inside `<std::boxed::Box<dyn std::ops::FnOnce() + std::marker::Send> as std::ops::FnOnce<()>>::call_once` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/alloc/src/boxed.rs:1854:9
   = note: inside `<std::panic::AssertUnwindSafe<std::boxed::Box<dyn std::ops::FnOnce() + std::marker::Send>> as std::ops::FnOnce<()>>::call_once` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/core/src/panic/unwind_safe.rs:271:9
   = note: inside `std::panicking::r#try::do_call::<std::panic::AssertUnwindSafe<std::boxed::Box<dyn std::ops::FnOnce() + std::marker::Send>>, ()>` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/panicking.rs:492:40
   = note: inside `std::panicking::r#try::<(), std::panic::AssertUnwindSafe<std::boxed::Box<dyn std::ops::FnOnce() + std::marker::Send>>>` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/panicking.rs:456:19
   = note: inside `std::panic::catch_unwind::<std::panic::AssertUnwindSafe<std::boxed::Box<dyn std::ops::FnOnce() + std::marker::Send>>, ()>` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/panic.rs:137:14
   = note: inside `tests::test::run_test_in_process` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/test/src/lib.rs:598:18
   = note: inside closure at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/test/src/lib.rs:492:39
   = note: inside `tests::test::run_test::run_test_inner` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/test/src/lib.rs:530:13
   = note: inside `tests::test::run_test` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/test/src/lib.rs:562:28
   = note: inside `tests::test::run_tests::<[closure@tests::test::run_tests_console::{closure#2}]>` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/test/src/lib.rs:305:17
   = note: inside `tests::test::run_tests_console` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/test/src/console.rs:290:5
   = note: inside `tests::test::test_main` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/test/src/lib.rs:116:15
   = note: inside `tests::test::test_main_static` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/test/src/lib.rs:135:5
   = note: inside `main`
   = note: inside `<fn() as std::ops::FnOnce<()>>::call_once - shim(fn())` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/core/src/ops/function.rs:227:5
   = note: inside `std::sys_common::backtrace::__rust_begin_short_backtrace::<fn(), ()>` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/sys_common/backtrace.rs:122:18
   = note: inside closure at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/rt.rs:145:18
   = note: inside `std::ops::function::impls::<impl std::ops::FnOnce<()> for &dyn std::ops::Fn() -> i32 + std::marker::Sync + std::panic::RefUnwindSafe>::call_once` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/core/src/ops/function.rs:259:13
   = note: inside `std::panicking::r#try::do_call::<&dyn std::ops::Fn() -> i32 + std::marker::Sync + std::panic::RefUnwindSafe, i32>` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/panicking.rs:492:40
   = note: inside `std::panicking::r#try::<i32, &dyn std::ops::Fn() -> i32 + std::marker::Sync + std::panic::RefUnwindSafe>` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/panicking.rs:456:19
   = note: inside `std::panic::catch_unwind::<&dyn std::ops::Fn() -> i32 + std::marker::Sync + std::panic::RefUnwindSafe, i32>` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/panic.rs:137:14
   = note: inside closure at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/rt.rs:128:48
   = note: inside `std::panicking::r#try::do_call::<[closure@std::rt::lang_start_internal::{closure#2}], isize>` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/panicking.rs:492:40
   = note: inside `std::panicking::r#try::<isize, [closure@std::rt::lang_start_internal::{closure#2}]>` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/panicking.rs:456:19
   = note: inside `std::panic::catch_unwind::<[closure@std::rt::lang_start_internal::{closure#2}], isize>` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/panic.rs:137:14
   = note: inside `std::rt::lang_start_internal` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/rt.rs:128:20
   = note: inside `std::rt::lang_start::<()>` at /home/ben/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/rt.rs:144:17
   = note: this error originates in the attribute macro `test` (in Nightly builds, run with -Z macro-backtrace for more info)

error: aborting due to previous error

error: test failed, to rerun pass '--bin scratch'
```

After:
```
    Finished test [unoptimized + debuginfo] target(s) in 0.00s
     Running unittests (target/miri/x86_64-unknown-linux-gnu/debug/deps/scratch-9d7717efc37bb64c)

running 1 test
test tests::it_works ... error: Undefined Behavior: type validation failed: encountered a dangling reference (address 0x1 is unallocated)
  --> src/main.rs:16:35
   |
16 |             let _x: &'static u8 = core::mem::transmute(1usize);
   |                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered a dangling reference (address 0x1 is unallocated)
   |
   = help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior
   = help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information

   = note: inside `tests::it_works` at src/main.rs:16:35
note: inside closure at src/main.rs:14:5
  --> src/main.rs:14:5
   |
13 |       #[test]
   |       ------- in this procedural macro expansion
14 | /     fn it_works() {
15 | |         unsafe {
16 | |             let _x: &'static u8 = core::mem::transmute(1usize);
17 | |         }
18 | |     }
   | |_____^
   = note: this error originates in the attribute macro `test` (in Nightly builds, run with -Z macro-backtrace for more info)

note: Some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace.

error: aborting due to previous error

error: test failed, to rerun pass '--bin scratch'
```
2022-02-22 15:39:07 +00:00