Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Thoroughly investigate transmute_undefined_repr #8496

Open
Manishearth opened this issue Mar 2, 2022 · 7 comments
Open

Thoroughly investigate transmute_undefined_repr #8496

Manishearth opened this issue Mar 2, 2022 · 7 comments
Labels
C-bug Category: Clippy is not doing the correct thing E-help-wanted Call for participation: Help is requested to fix this issue.

Comments

@Manishearth
Copy link
Member

Manishearth commented Mar 2, 2022 •
edited
Loading

See discussion in #8432

The lint is currently in the nursery and has had multiple problems in the past. We should do a deeper investigation: probably running it on a lot of crates and looking for false positives, as well as trying to structure it to be more conservative by default.

Subissues:
@Manishearth Manishearth mentioned this issue Mar 2, 2022
Merged
@Manishearth Manishearth added C-bug Category: Clippy is not doing the correct thing E-help-wanted Call for participation: Help is requested to fix this issue. labels Mar 2, 2022
@ghost
Copy link

ghost commented Mar 3, 2022

Ran this lint the top 1000 (more or less) crates from crates.io. Here are the warnings I found.

I'm unable to say which are false positives.

Hope this helps.

Crate Number
cgmath-0.18.0 32
criterion-0.3.5 1
iovec-0.1.4 3
nalgebra-0.30.1 2
parity-scale-codec-3.0.0 20
prettytable-rs-0.8.0 1
state-0.5.2 1
wasm-bindgen-0.2.79 40
Full warnings 
---> cgmath-0.18.0/src/quaternion.rs:600:18                                                       
warning: transmute into `&(S, S, S, S)` which has an undefined layout                             
   --> src/quaternion.rs:600:18
    |
600 |         unsafe { mem::transmute(self) }
    |                  ^^^^^^^^^^^^^^^^^^^^
    |
    = note: requested on the command line with `-W clippy::transmute-undefined-repr`
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr


---> cgmath-0.18.0/src/quaternion.rs:607:18                                                       
warning: transmute into `&mut (S, S, S, S)` which has an undefined layout                         
   --> src/quaternion.rs:607:18
    |
607 |         unsafe { mem::transmute(self) }
    |                  ^^^^^^^^^^^^^^^^^^^^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr


---> cgmath-0.18.0/src/quaternion.rs:623:18                                                       
warning: transmute from `&(S, S, S, S)` which has an undefined layout                             
   --> src/quaternion.rs:623:18
    |
623 |         unsafe { mem::transmute(v) }
    |                  ^^^^^^^^^^^^^^^^^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr


---> cgmath-0.18.0/src/quaternion.rs:630:18                                                       
warning: transmute from `&mut (S, S, S, S)` which has an undefined layout                         
   --> src/quaternion.rs:630:18
    |
630 |         unsafe { mem::transmute(v) }
    |                  ^^^^^^^^^^^^^^^^^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr


---> cgmath-0.18.0/src/macros.rs:229:26                                                           
warning: transmute into `&(S,)` which has an undefined layout                                     
   --> src/macros.rs:229:26
    |
229 |                 unsafe { mem::transmute(self) }
    |                          ^^^^^^^^^^^^^^^^^^^^
    |
   ::: src/vector.rs:384:1
    |
384 | impl_tuple_conversions!(Vector1<S> { x }, (S,));
    | ----------------------------------------------- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `impl_tuple_conversions` (in Nightly builds, run with -Z macro-backtrace for more info)


---> cgmath-0.18.0/src/macros.rs:236:26                                                           
warning: transmute into `&mut (S,)` which has an undefined layout                                 
   --> src/macros.rs:236:26
    |
236 |                 unsafe { mem::transmute(self) }
    |                          ^^^^^^^^^^^^^^^^^^^^
    |
   ::: src/vector.rs:384:1
    |
384 | impl_tuple_conversions!(Vector1<S> { x }, (S,));
    | ----------------------------------------------- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `impl_tuple_conversions` (in Nightly builds, run with -Z macro-backtrace for more info)


---> cgmath-0.18.0/src/macros.rs:250:26                                                           
warning: transmute from `&(S,)` which has an undefined layout                                     
   --> src/macros.rs:250:26
    |
250 |                 unsafe { mem::transmute(v) }
    |                          ^^^^^^^^^^^^^^^^^
    |
   ::: src/vector.rs:384:1
    |
384 | impl_tuple_conversions!(Vector1<S> { x }, (S,));
    | ----------------------------------------------- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `impl_tuple_conversions` (in Nightly builds, run with -Z macro-backtrace for more info)


---> cgmath-0.18.0/src/macros.rs:257:26                                                           
warning: transmute from `&mut (S,)` which has an undefined layout                                 
   --> src/macros.rs:257:26
    |
257 |                 unsafe { mem::transmute(v) }
    |                          ^^^^^^^^^^^^^^^^^
    |
   ::: src/vector.rs:384:1
    |
384 | impl_tuple_conversions!(Vector1<S> { x }, (S,));
    | ----------------------------------------------- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `impl_tuple_conversions` (in Nightly builds, run with -Z macro-backtrace for more info)


---> cgmath-0.18.0/src/macros.rs:229:26                                                           
warning: transmute into `&(S, S)` which has an undefined layout                                   
   --> src/macros.rs:229:26
    |
229 |                 unsafe { mem::transmute(self) }
    |                          ^^^^^^^^^^^^^^^^^^^^
    |
   ::: src/vector.rs:385:1
    |
385 | impl_tuple_conversions!(Vector2<S> { x, y }, (S, S));
    | ---------------------------------------------------- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `impl_tuple_conversions` (in Nightly builds, run with -Z macro-backtrace for more info)


---> cgmath-0.18.0/src/macros.rs:236:26                                                           
warning: transmute into `&mut (S, S)` which has an undefined layout                               
   --> src/macros.rs:236:26
    |
236 |                 unsafe { mem::transmute(self) }
    |                          ^^^^^^^^^^^^^^^^^^^^
    |
   ::: src/vector.rs:385:1
    |
385 | impl_tuple_conversions!(Vector2<S> { x, y }, (S, S));
    | ---------------------------------------------------- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `impl_tuple_conversions` (in Nightly builds, run with -Z macro-backtrace for more info)


---> cgmath-0.18.0/src/macros.rs:250:26                                                           
warning: transmute from `&(S, S)` which has an undefined layout                                   
   --> src/macros.rs:250:26
    |
250 |                 unsafe { mem::transmute(v) }
    |                          ^^^^^^^^^^^^^^^^^
    |
   ::: src/vector.rs:385:1
    |
385 | impl_tuple_conversions!(Vector2<S> { x, y }, (S, S));
    | ---------------------------------------------------- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `impl_tuple_conversions` (in Nightly builds, run with -Z macro-backtrace for more info)


---> cgmath-0.18.0/src/macros.rs:257:26                                                           
warning: transmute from `&mut (S, S)` which has an undefined layout                               
   --> src/macros.rs:257:26
    |
257 |                 unsafe { mem::transmute(v) }
    |                          ^^^^^^^^^^^^^^^^^
    |
   ::: src/vector.rs:385:1
    |
385 | impl_tuple_conversions!(Vector2<S> { x, y }, (S, S));
    | ---------------------------------------------------- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `impl_tuple_conversions` (in Nightly builds, run with -Z macro-backtrace for more info)


---> cgmath-0.18.0/src/macros.rs:229:26                                                           
warning: transmute into `&(S, S, S)` which has an undefined layout                                
   --> src/macros.rs:229:26
    |
229 |                 unsafe { mem::transmute(self) }
    |                          ^^^^^^^^^^^^^^^^^^^^
    |
   ::: src/vector.rs:386:1
    |
386 | impl_tuple_conversions!(Vector3<S> { x, y, z }, (S, S, S));
    | ---------------------------------------------------------- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `impl_tuple_conversions` (in Nightly builds, run with -Z macro-backtrace for more info)


---> cgmath-0.18.0/src/macros.rs:236:26                                                           
warning: transmute into `&mut (S, S, S)` which has an undefined layout                            
   --> src/macros.rs:236:26
    |
236 |                 unsafe { mem::transmute(self) }
    |                          ^^^^^^^^^^^^^^^^^^^^
    |
   ::: src/vector.rs:386:1
    |
386 | impl_tuple_conversions!(Vector3<S> { x, y, z }, (S, S, S));
    | ---------------------------------------------------------- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `impl_tuple_conversions` (in Nightly builds, run with -Z macro-backtrace for more info)


---> cgmath-0.18.0/src/macros.rs:250:26                                                           
warning: transmute from `&(S, S, S)` which has an undefined layout                                
   --> src/macros.rs:250:26
    |
250 |                 unsafe { mem::transmute(v) }
    |                          ^^^^^^^^^^^^^^^^^
    |
   ::: src/vector.rs:386:1
    |
386 | impl_tuple_conversions!(Vector3<S> { x, y, z }, (S, S, S));
    | ---------------------------------------------------------- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `impl_tuple_conversions` (in Nightly builds, run with -Z macro-backtrace for more info)


---> cgmath-0.18.0/src/macros.rs:257:26                                                           
warning: transmute from `&mut (S, S, S)` which has an undefined layout                            
   --> src/macros.rs:257:26
    |
257 |                 unsafe { mem::transmute(v) }
    |                          ^^^^^^^^^^^^^^^^^
    |
   ::: src/vector.rs:386:1
    |
386 | impl_tuple_conversions!(Vector3<S> { x, y, z }, (S, S, S));
    | ---------------------------------------------------------- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `impl_tuple_conversions` (in Nightly builds, run with -Z macro-backtrace for more info)


---> cgmath-0.18.0/src/macros.rs:229:26                                                           
warning: transmute into `&(S, S, S, S)` which has an undefined layout                             
   --> src/macros.rs:229:26
    |
229 |                 unsafe { mem::transmute(self) }
    |                          ^^^^^^^^^^^^^^^^^^^^
    |
   ::: src/vector.rs:387:1
    |
387 | impl_tuple_conversions!(Vector4<S> { x, y, z, w }, (S, S, S, S));
    | ---------------------------------------------------------------- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `impl_tuple_conversions` (in Nightly builds, run with -Z macro-backtrace for more info)


---> cgmath-0.18.0/src/macros.rs:236:26                                                           
warning: transmute into `&mut (S, S, S, S)` which has an undefined layout                         
   --> src/macros.rs:236:26
    |
236 |                 unsafe { mem::transmute(self) }
    |                          ^^^^^^^^^^^^^^^^^^^^
    |
   ::: src/vector.rs:387:1
    |
387 | impl_tuple_conversions!(Vector4<S> { x, y, z, w }, (S, S, S, S));
    | ---------------------------------------------------------------- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `impl_tuple_conversions` (in Nightly builds, run with -Z macro-backtrace for more info)


---> cgmath-0.18.0/src/macros.rs:250:26                                                           
warning: transmute from `&(S, S, S, S)` which has an undefined layout                             
   --> src/macros.rs:250:26
    |
250 |                 unsafe { mem::transmute(v) }
    |                          ^^^^^^^^^^^^^^^^^
    |
   ::: src/vector.rs:387:1
    |
387 | impl_tuple_conversions!(Vector4<S> { x, y, z, w }, (S, S, S, S));
    | ---------------------------------------------------------------- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `impl_tuple_conversions` (in Nightly builds, run with -Z macro-backtrace for more info)


---> cgmath-0.18.0/src/macros.rs:257:26                                                           
warning: transmute from `&mut (S, S, S, S)` which has an undefined layout                         
   --> src/macros.rs:257:26
    |
257 |                 unsafe { mem::transmute(v) }
    |                          ^^^^^^^^^^^^^^^^^
    |
   ::: src/vector.rs:387:1
    |
387 | impl_tuple_conversions!(Vector4<S> { x, y, z, w }, (S, S, S, S));
    | ---------------------------------------------------------------- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `impl_tuple_conversions` (in Nightly builds, run with -Z macro-backtrace for more info)


---> cgmath-0.18.0/src/macros.rs:229:26                                                           
warning: transmute into `&(S,)` which has an undefined layout                                     
   --> src/macros.rs:229:26
    |
229 |                 unsafe { mem::transmute(self) }
    |                          ^^^^^^^^^^^^^^^^^^^^
    |
   ::: src/point.rs:362:1
    |
362 | impl_tuple_conversions!(Point1<S> { x }, (S,));
    | ---------------------------------------------- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `impl_tuple_conversions` (in Nightly builds, run with -Z macro-backtrace for more info)


---> cgmath-0.18.0/src/macros.rs:236:26                                                           
warning: transmute into `&mut (S,)` which has an undefined layout                                 
   --> src/macros.rs:236:26
    |
236 |                 unsafe { mem::transmute(self) }
    |                          ^^^^^^^^^^^^^^^^^^^^
    |
   ::: src/point.rs:362:1
    |
362 | impl_tuple_conversions!(Point1<S> { x }, (S,));
    | ---------------------------------------------- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `impl_tuple_conversions` (in Nightly builds, run with -Z macro-backtrace for more info)


---> cgmath-0.18.0/src/macros.rs:250:26                                                           
warning: transmute from `&(S,)` which has an undefined layout                                     
   --> src/macros.rs:250:26
    |
250 |                 unsafe { mem::transmute(v) }
    |                          ^^^^^^^^^^^^^^^^^
    |
   ::: src/point.rs:362:1
    |
362 | impl_tuple_conversions!(Point1<S> { x }, (S,));
    | ---------------------------------------------- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `impl_tuple_conversions` (in Nightly builds, run with -Z macro-backtrace for more info)


---> cgmath-0.18.0/src/macros.rs:257:26                                                           
warning: transmute from `&mut (S,)` which has an undefined layout                                 
   --> src/macros.rs:257:26
    |
257 |                 unsafe { mem::transmute(v) }
    |                          ^^^^^^^^^^^^^^^^^
    |
   ::: src/point.rs:362:1
    |
362 | impl_tuple_conversions!(Point1<S> { x }, (S,));
    | ---------------------------------------------- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `impl_tuple_conversions` (in Nightly builds, run with -Z macro-backtrace for more info)


---> cgmath-0.18.0/src/macros.rs:229:26                                                           
warning: transmute into `&(S, S)` which has an undefined layout                                   
   --> src/macros.rs:229:26
    |
229 |                 unsafe { mem::transmute(self) }
    |                          ^^^^^^^^^^^^^^^^^^^^
    |
   ::: src/point.rs:363:1
    |
363 | impl_tuple_conversions!(Point2<S> { x, y }, (S, S));
    | --------------------------------------------------- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `impl_tuple_conversions` (in Nightly builds, run with -Z macro-backtrace for more info)


---> cgmath-0.18.0/src/macros.rs:236:26                                                           
warning: transmute into `&mut (S, S)` which has an undefined layout                               
   --> src/macros.rs:236:26
    |
236 |                 unsafe { mem::transmute(self) }
    |                          ^^^^^^^^^^^^^^^^^^^^
    |
   ::: src/point.rs:363:1
    |
363 | impl_tuple_conversions!(Point2<S> { x, y }, (S, S));
    | --------------------------------------------------- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `impl_tuple_conversions` (in Nightly builds, run with -Z macro-backtrace for more info)


---> cgmath-0.18.0/src/macros.rs:250:26                                                           
warning: transmute from `&(S, S)` which has an undefined layout                                   
   --> src/macros.rs:250:26
    |
250 |                 unsafe { mem::transmute(v) }
    |                          ^^^^^^^^^^^^^^^^^
    |
   ::: src/point.rs:363:1
    |
363 | impl_tuple_conversions!(Point2<S> { x, y }, (S, S));
    | --------------------------------------------------- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `impl_tuple_conversions` (in Nightly builds, run with -Z macro-backtrace for more info)


---> cgmath-0.18.0/src/macros.rs:257:26                                                           
warning: transmute from `&mut (S, S)` which has an undefined layout                               
   --> src/macros.rs:257:26
    |
257 |                 unsafe { mem::transmute(v) }
    |                          ^^^^^^^^^^^^^^^^^
    |
   ::: src/point.rs:363:1
    |
363 | impl_tuple_conversions!(Point2<S> { x, y }, (S, S));
    | --------------------------------------------------- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `impl_tuple_conversions` (in Nightly builds, run with -Z macro-backtrace for more info)


---> cgmath-0.18.0/src/macros.rs:229:26                                                           
warning: transmute into `&(S, S, S)` which has an undefined layout                                
   --> src/macros.rs:229:26
    |
229 |                 unsafe { mem::transmute(self) }
    |                          ^^^^^^^^^^^^^^^^^^^^
    |
   ::: src/point.rs:364:1
    |
364 | impl_tuple_conversions!(Point3<S> { x, y, z }, (S, S, S));
    | --------------------------------------------------------- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `impl_tuple_conversions` (in Nightly builds, run with -Z macro-backtrace for more info)


---> cgmath-0.18.0/src/macros.rs:236:26                                                           
warning: transmute into `&mut (S, S, S)` which has an undefined layout                            
   --> src/macros.rs:236:26
    |
236 |                 unsafe { mem::transmute(self) }
    |                          ^^^^^^^^^^^^^^^^^^^^
    |
   ::: src/point.rs:364:1
    |
364 | impl_tuple_conversions!(Point3<S> { x, y, z }, (S, S, S));
    | --------------------------------------------------------- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `impl_tuple_conversions` (in Nightly builds, run with -Z macro-backtrace for more info)


---> cgmath-0.18.0/src/macros.rs:250:26                                                           
warning: transmute from `&(S, S, S)` which has an undefined layout                                
   --> src/macros.rs:250:26
    |
250 |                 unsafe { mem::transmute(v) }
    |                          ^^^^^^^^^^^^^^^^^
    |
   ::: src/point.rs:364:1
    |
364 | impl_tuple_conversions!(Point3<S> { x, y, z }, (S, S, S));
    | --------------------------------------------------------- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `impl_tuple_conversions` (in Nightly builds, run with -Z macro-backtrace for more info)


---> cgmath-0.18.0/src/macros.rs:257:26                                                           
warning: transmute from `&mut (S, S, S)` which has an undefined layout                            
   --> src/macros.rs:257:26
    |
257 |                 unsafe { mem::transmute(v) }
    |                          ^^^^^^^^^^^^^^^^^
    |
   ::: src/point.rs:364:1
    |
364 | impl_tuple_conversions!(Point3<S> { x, y, z }, (S, S, S));
    | --------------------------------------------------------- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `impl_tuple_conversions` (in Nightly builds, run with -Z macro-backtrace for more info)


---> criterion-0.3.5/src/stats/univariate/resamples.rs:55:22                                      
warning: transmute from `&std::vec::Vec<A>` which has an undefined layout                         
  --> src/stats/univariate/resamples.rs:55:22
   |
55 |             unsafe { mem::transmute::<&[_], _>(v) }
   |                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: requested on the command line with `-W clippy::transmute-undefined-repr`
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr

---> iovec-0.1.4/src/sys/unix.rs:26:9                                                             
warning: transmute from `&[u8]` which has an undefined layout                                     
  --> src/sys/unix.rs:26:9
   |
26 |         mem::transmute(&self.inner)
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: requested on the command line with `-W clippy::transmute-undefined-repr`
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr


---> iovec-0.1.4/src/sys/unix.rs:34:13                                                            
warning: transmute to `&sys::unix::IoVec` which has an undefined layout                           
  --> src/sys/unix.rs:34:13
   |
34 | /             mem::transmute(libc::iovec {
35 | |                 iov_base: src.as_ptr() as *mut _,
36 | |                 iov_len: src.len(),
37 | |             })
   | |______________^
   |
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr


---> iovec-0.1.4/src/sys/unix.rs:46:13                                                            
warning: transmute to `&mut sys::unix::IoVec` which has an undefined layout                       
  --> src/sys/unix.rs:46:13
   |
46 | /             mem::transmute(libc::iovec {
47 | |                 iov_base: src.as_ptr() as *mut _,
48 | |                 iov_len: src.len(),
49 | |             })
   | |______________^
   |
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr


---> nalgebra-0.30.1/src/linalg/svd.rs:137:48                                                     
warning: transmute from `&linalg::svd::SVD<<T as simba::scalar::ComplexField>::RealField, base::dimension::Const<2_usize>, base::dimension::Const<2_usize>>` to `&linalg::svd::SVD<T, R, C>`, both of which have an undefined layout
   --> src/linalg/svd.rs:137:48
    |
137 |             let typed_result: &Self = unsafe { std::mem::transmute(&result) };
    |                                                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: requested on the command line with `-W clippy::transmute-undefined-repr`
    = note: two instances of the same generic type (`SVD`) may have different layouts
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr


---> nalgebra-0.30.1/src/linalg/svd.rs:143:48                                                     
warning: transmute into `&linalg::svd::SVD<T, R, C>` which has an undefined layout                
   --> src/linalg/svd.rs:143:48
    |
143 |             let typed_result: &Self = unsafe { std::mem::transmute(&result) };
    |                                                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr


---> parity-scale-codec-3.0.0/src/codec.rs:774:17                                                 
warning: transmute from `std::vec::Vec<u8>` to `std::vec::Vec<T>`, both of which have an undefined layout
   --> src/codec.rs:774:17
    |
774 |                   Ok(unsafe { mem::transmute::<Vec<$ty>, Vec<T>>(vec) })
    |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...
781 | /     with_type_info! {
782 | |         <T as Decode>::TYPE_INFO,
783 | |         decode(input, len),
784 | |         {
785 | |             decode_unoptimized(input, len)
786 | |         },
787 | |     }
    | |_____- in this macro invocation
    |
    = note: requested on the command line with `-W clippy::transmute-undefined-repr`
    = note: two instances of the same generic type (`Vec`) may have different layouts
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `decode` (in Nightly builds, run with -Z macro-backtrace for more info)


---> parity-scale-codec-3.0.0/src/codec.rs:774:17                                                 
warning: transmute from `std::vec::Vec<i8>` to `std::vec::Vec<T>`, both of which have an undefined layout
   --> src/codec.rs:774:17
    |
774 |                   Ok(unsafe { mem::transmute::<Vec<$ty>, Vec<T>>(vec) })
    |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...
781 | /     with_type_info! {
782 | |         <T as Decode>::TYPE_INFO,
783 | |         decode(input, len),
784 | |         {
785 | |             decode_unoptimized(input, len)
786 | |         },
787 | |     }
    | |_____- in this macro invocation
    |
    = note: two instances of the same generic type (`Vec`) may have different layouts
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `decode` (in Nightly builds, run with -Z macro-backtrace for more info)


---> parity-scale-codec-3.0.0/src/codec.rs:774:17                                                 
warning: transmute from `std::vec::Vec<u16>` to `std::vec::Vec<T>`, both of which have an undefined layout
   --> src/codec.rs:774:17
    |
774 |                   Ok(unsafe { mem::transmute::<Vec<$ty>, Vec<T>>(vec) })
    |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...
781 | /     with_type_info! {
782 | |         <T as Decode>::TYPE_INFO,
783 | |         decode(input, len),
784 | |         {
785 | |             decode_unoptimized(input, len)
786 | |         },
787 | |     }
    | |_____- in this macro invocation
    |
    = note: two instances of the same generic type (`Vec`) may have different layouts
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `decode` (in Nightly builds, run with -Z macro-backtrace for more info)


---> parity-scale-codec-3.0.0/src/codec.rs:774:17                                                 
warning: transmute from `std::vec::Vec<i16>` to `std::vec::Vec<T>`, both of which have an undefined layout
   --> src/codec.rs:774:17
    |
774 |                   Ok(unsafe { mem::transmute::<Vec<$ty>, Vec<T>>(vec) })
    |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...
781 | /     with_type_info! {
782 | |         <T as Decode>::TYPE_INFO,
783 | |         decode(input, len),
784 | |         {
785 | |             decode_unoptimized(input, len)
786 | |         },
787 | |     }
    | |_____- in this macro invocation
    |
    = note: two instances of the same generic type (`Vec`) may have different layouts
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `decode` (in Nightly builds, run with -Z macro-backtrace for more info)


---> parity-scale-codec-3.0.0/src/codec.rs:774:17                                                 
warning: transmute from `std::vec::Vec<u32>` to `std::vec::Vec<T>`, both of which have an undefined layout
   --> src/codec.rs:774:17
    |
774 |                   Ok(unsafe { mem::transmute::<Vec<$ty>, Vec<T>>(vec) })
    |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...
781 | /     with_type_info! {
782 | |         <T as Decode>::TYPE_INFO,
783 | |         decode(input, len),
784 | |         {
785 | |             decode_unoptimized(input, len)
786 | |         },
787 | |     }
    | |_____- in this macro invocation
    |
    = note: two instances of the same generic type (`Vec`) may have different layouts
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `decode` (in Nightly builds, run with -Z macro-backtrace for more info)


---> parity-scale-codec-3.0.0/src/codec.rs:774:17                                                 
warning: transmute from `std::vec::Vec<i32>` to `std::vec::Vec<T>`, both of which have an undefined layout
   --> src/codec.rs:774:17
    |
774 |                   Ok(unsafe { mem::transmute::<Vec<$ty>, Vec<T>>(vec) })
    |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...
781 | /     with_type_info! {
782 | |         <T as Decode>::TYPE_INFO,
783 | |         decode(input, len),
784 | |         {
785 | |             decode_unoptimized(input, len)
786 | |         },
787 | |     }
    | |_____- in this macro invocation
    |
    = note: two instances of the same generic type (`Vec`) may have different layouts
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `decode` (in Nightly builds, run with -Z macro-backtrace for more info)


---> parity-scale-codec-3.0.0/src/codec.rs:774:17                                                 
warning: transmute from `std::vec::Vec<u64>` to `std::vec::Vec<T>`, both of which have an undefined layout
   --> src/codec.rs:774:17
    |
774 |                   Ok(unsafe { mem::transmute::<Vec<$ty>, Vec<T>>(vec) })
    |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...
781 | /     with_type_info! {
782 | |         <T as Decode>::TYPE_INFO,
783 | |         decode(input, len),
784 | |         {
785 | |             decode_unoptimized(input, len)
786 | |         },
787 | |     }
    | |_____- in this macro invocation
    |
    = note: two instances of the same generic type (`Vec`) may have different layouts
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `decode` (in Nightly builds, run with -Z macro-backtrace for more info)


---> parity-scale-codec-3.0.0/src/codec.rs:774:17                                                 
warning: transmute from `std::vec::Vec<i64>` to `std::vec::Vec<T>`, both of which have an undefined layout
   --> src/codec.rs:774:17
    |
774 |                   Ok(unsafe { mem::transmute::<Vec<$ty>, Vec<T>>(vec) })
    |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...
781 | /     with_type_info! {
782 | |         <T as Decode>::TYPE_INFO,
783 | |         decode(input, len),
784 | |         {
785 | |             decode_unoptimized(input, len)
786 | |         },
787 | |     }
    | |_____- in this macro invocation
    |
    = note: two instances of the same generic type (`Vec`) may have different layouts
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `decode` (in Nightly builds, run with -Z macro-backtrace for more info)


---> parity-scale-codec-3.0.0/src/codec.rs:774:17                                                 
warning: transmute from `std::vec::Vec<u128>` to `std::vec::Vec<T>`, both of which have an undefined layout
   --> src/codec.rs:774:17
    |
774 |                   Ok(unsafe { mem::transmute::<Vec<$ty>, Vec<T>>(vec) })
    |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...
781 | /     with_type_info! {
782 | |         <T as Decode>::TYPE_INFO,
783 | |         decode(input, len),
784 | |         {
785 | |             decode_unoptimized(input, len)
786 | |         },
787 | |     }
    | |_____- in this macro invocation
    |
    = note: two instances of the same generic type (`Vec`) may have different layouts
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `decode` (in Nightly builds, run with -Z macro-backtrace for more info)


---> parity-scale-codec-3.0.0/src/codec.rs:774:17                                                 
warning: transmute from `std::vec::Vec<i128>` to `std::vec::Vec<T>`, both of which have an undefined layout
   --> src/codec.rs:774:17
    |
774 |                   Ok(unsafe { mem::transmute::<Vec<$ty>, Vec<T>>(vec) })
    |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...
781 | /     with_type_info! {
782 | |         <T as Decode>::TYPE_INFO,
783 | |         decode(input, len),
784 | |         {
785 | |             decode_unoptimized(input, len)
786 | |         },
787 | |     }
    | |_____- in this macro invocation
    |
    = note: two instances of the same generic type (`Vec`) may have different layouts
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `decode` (in Nightly builds, run with -Z macro-backtrace for more info)


---> parity-scale-codec-3.0.0/src/codec.rs:1041:7                                                 
warning: transmute from `(&[T], &[T])` to `(&[u8], &[u8])`, both of which have an undefined layout
    --> src/codec.rs:1041:7
     |
1041 |                           core::mem::transmute::<(&[T], &[T]), (&[$ty], &[$ty])>(slices)
     |                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...
1054 | /         with_type_info! {
1055 | |             <T as Encode>::TYPE_INFO,
1056 | |             encode_to(self, dest),
1057 | |             {
...    |
1061 | |             },
1062 | |         }
     | |_________- in this macro invocation
     |
     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
     = note: this warning originates in the macro `encode_to` (in Nightly builds, run with -Z macro-backtrace for more info)


---> parity-scale-codec-3.0.0/src/codec.rs:1041:7                                                 
warning: transmute from `(&[T], &[T])` to `(&[i8], &[i8])`, both of which have an undefined layout
    --> src/codec.rs:1041:7
     |
1041 |                           core::mem::transmute::<(&[T], &[T]), (&[$ty], &[$ty])>(slices)
     |                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...
1054 | /         with_type_info! {
1055 | |             <T as Encode>::TYPE_INFO,
1056 | |             encode_to(self, dest),
1057 | |             {
...    |
1061 | |             },
1062 | |         }
     | |_________- in this macro invocation
     |
     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
     = note: this warning originates in the macro `encode_to` (in Nightly builds, run with -Z macro-backtrace for more info)


---> parity-scale-codec-3.0.0/src/codec.rs:1041:7                                                 
warning: transmute from `(&[T], &[T])` to `(&[u16], &[u16])`, both of which have an undefined layout
    --> src/codec.rs:1041:7
     |
1041 |                           core::mem::transmute::<(&[T], &[T]), (&[$ty], &[$ty])>(slices)
     |                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...
1054 | /         with_type_info! {
1055 | |             <T as Encode>::TYPE_INFO,
1056 | |             encode_to(self, dest),
1057 | |             {
...    |
1061 | |             },
1062 | |         }
     | |_________- in this macro invocation
     |
     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
     = note: this warning originates in the macro `encode_to` (in Nightly builds, run with -Z macro-backtrace for more info)


---> parity-scale-codec-3.0.0/src/codec.rs:1041:7                                                 
warning: transmute from `(&[T], &[T])` to `(&[i16], &[i16])`, both of which have an undefined layout
    --> src/codec.rs:1041:7
     |
1041 |                           core::mem::transmute::<(&[T], &[T]), (&[$ty], &[$ty])>(slices)
     |                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...
1054 | /         with_type_info! {
1055 | |             <T as Encode>::TYPE_INFO,
1056 | |             encode_to(self, dest),
1057 | |             {
...    |
1061 | |             },
1062 | |         }
     | |_________- in this macro invocation
     |
     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
     = note: this warning originates in the macro `encode_to` (in Nightly builds, run with -Z macro-backtrace for more info)


---> parity-scale-codec-3.0.0/src/codec.rs:1041:7                                                 
warning: transmute from `(&[T], &[T])` to `(&[u32], &[u32])`, both of which have an undefined layout
    --> src/codec.rs:1041:7
     |
1041 |                           core::mem::transmute::<(&[T], &[T]), (&[$ty], &[$ty])>(slices)
     |                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...
1054 | /         with_type_info! {
1055 | |             <T as Encode>::TYPE_INFO,
1056 | |             encode_to(self, dest),
1057 | |             {
...    |
1061 | |             },
1062 | |         }
     | |_________- in this macro invocation
     |
     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
     = note: this warning originates in the macro `encode_to` (in Nightly builds, run with -Z macro-backtrace for more info)


---> parity-scale-codec-3.0.0/src/codec.rs:1041:7                                                 
warning: transmute from `(&[T], &[T])` to `(&[i32], &[i32])`, both of which have an undefined layout
    --> src/codec.rs:1041:7
     |
1041 |                           core::mem::transmute::<(&[T], &[T]), (&[$ty], &[$ty])>(slices)
     |                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...
1054 | /         with_type_info! {
1055 | |             <T as Encode>::TYPE_INFO,
1056 | |             encode_to(self, dest),
1057 | |             {
...    |
1061 | |             },
1062 | |         }
     | |_________- in this macro invocation
     |
     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
     = note: this warning originates in the macro `encode_to` (in Nightly builds, run with -Z macro-backtrace for more info)


---> parity-scale-codec-3.0.0/src/codec.rs:1041:7                                                 
warning: transmute from `(&[T], &[T])` to `(&[u64], &[u64])`, both of which have an undefined layout
    --> src/codec.rs:1041:7
     |
1041 |                           core::mem::transmute::<(&[T], &[T]), (&[$ty], &[$ty])>(slices)
     |                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...
1054 | /         with_type_info! {
1055 | |             <T as Encode>::TYPE_INFO,
1056 | |             encode_to(self, dest),
1057 | |             {
...    |
1061 | |             },
1062 | |         }
     | |_________- in this macro invocation
     |
     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
     = note: this warning originates in the macro `encode_to` (in Nightly builds, run with -Z macro-backtrace for more info)


---> parity-scale-codec-3.0.0/src/codec.rs:1041:7                                                 
warning: transmute from `(&[T], &[T])` to `(&[i64], &[i64])`, both of which have an undefined layout
    --> src/codec.rs:1041:7
     |
1041 |                           core::mem::transmute::<(&[T], &[T]), (&[$ty], &[$ty])>(slices)
     |                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...
1054 | /         with_type_info! {
1055 | |             <T as Encode>::TYPE_INFO,
1056 | |             encode_to(self, dest),
1057 | |             {
...    |
1061 | |             },
1062 | |         }
     | |_________- in this macro invocation
     |
     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
     = note: this warning originates in the macro `encode_to` (in Nightly builds, run with -Z macro-backtrace for more info)


---> parity-scale-codec-3.0.0/src/codec.rs:1041:7                                                 
warning: transmute from `(&[T], &[T])` to `(&[u128], &[u128])`, both of which have an undefined layout
    --> src/codec.rs:1041:7
     |
1041 |                           core::mem::transmute::<(&[T], &[T]), (&[$ty], &[$ty])>(slices)
     |                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...
1054 | /         with_type_info! {
1055 | |             <T as Encode>::TYPE_INFO,
1056 | |             encode_to(self, dest),
1057 | |             {
...    |
1061 | |             },
1062 | |         }
     | |_________- in this macro invocation
     |
     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
     = note: this warning originates in the macro `encode_to` (in Nightly builds, run with -Z macro-backtrace for more info)


---> parity-scale-codec-3.0.0/src/codec.rs:1041:7                                                 
warning: transmute from `(&[T], &[T])` to `(&[i128], &[i128])`, both of which have an undefined layout
    --> src/codec.rs:1041:7
     |
1041 |                           core::mem::transmute::<(&[T], &[T]), (&[$ty], &[$ty])>(slices)
     |                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...
1054 | /         with_type_info! {
1055 | |             <T as Encode>::TYPE_INFO,
1056 | |             encode_to(self, dest),
1057 | |             {
...    |
1061 | |             },
1062 | |         }
     | |_________- in this macro invocation
     |
     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
     = note: this warning originates in the macro `encode_to` (in Nightly builds, run with -Z macro-backtrace for more info)


---> prettytable-rs-0.8.0/src/lib.rs:505:13                                                       
warning: transmute from `&Table` to `&TableSlice`, both of which have an undefined layout         
   --> src/lib.rs:505:13
    |
505 |             transmute(self)
    |             ^^^^^^^^^^^^^^^
    |
    = note: requested on the command line with `-W clippy::transmute-undefined-repr`
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr

---> state-0.5.2/src/container.rs:205:18                                                          
warning: transmute from `*mut dyn std::any::Any` which has an undefined layout                    
   --> src/container.rs:205:18
    |
205 |         unsafe { std::mem::transmute(any) }
    |                  ^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: requested on the command line with `-W clippy::transmute-undefined-repr`
    = note: the contained type `&dyn std::any::Any` has an undefined layout
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr


---> wasm-bindgen-0.2.79/src/convert/closures.rs:19:50                                            
warning: transmute from `&dyn core::ops::Fn() -> R` which has an undefined layout                 
   --> src/convert/closures.rs:19:50
    |
19  |                       let (a, b): (usize, usize) = mem::transmute(self);
    |                                                    ^^^^^^^^^^^^^^^^^^^^
...
111 | / stack_closures! {
112 | |     (0 invoke0 invoke0_mut)
113 | |     (1 invoke1 invoke1_mut A)
114 | |     (2 invoke2 invoke2_mut A B)
...   |
120 | |     (8 invoke8 invoke8_mut A B C D E F G H)
121 | | }
    | |_- in this macro invocation
    |
    = note: requested on the command line with `-W clippy::transmute-undefined-repr`
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `stack_closures` (in Nightly builds, run with -Z macro-backtrace for more info)


---> wasm-bindgen-0.2.79/src/convert/closures.rs:37:50                                            
warning: transmute to `&dyn core::ops::Fn() -> R` which has an undefined layout                   
   --> src/convert/closures.rs:37:50
    |
37  |                   let f: &dyn Fn($($var),*) -> R = mem::transmute((a, b));
    |                                                    ^^^^^^^^^^^^^^^^^^^^^^
...
111 | / stack_closures! {
112 | |     (0 invoke0 invoke0_mut)
113 | |     (1 invoke1 invoke1_mut A)
114 | |     (2 invoke2 invoke2_mut A B)
...   |
120 | |     (8 invoke8 invoke8_mut A B C D E F G H)
121 | | }
    | |_- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `stack_closures` (in Nightly builds, run with -Z macro-backtrace for more info)


---> wasm-bindgen-0.2.79/src/convert/closures.rs:68:50                                            
warning: transmute from `&mut dyn core::ops::FnMut() -> R` which has an undefined layout          
   --> src/convert/closures.rs:68:50
    |
68  |                       let (a, b): (usize, usize) = mem::transmute(self);
    |                                                    ^^^^^^^^^^^^^^^^^^^^
...
111 | / stack_closures! {
112 | |     (0 invoke0 invoke0_mut)
113 | |     (1 invoke1 invoke1_mut A)
114 | |     (2 invoke2 invoke2_mut A B)
...   |
120 | |     (8 invoke8 invoke8_mut A B C D E F G H)
121 | | }
    | |_- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `stack_closures` (in Nightly builds, run with -Z macro-backtrace for more info)


---> wasm-bindgen-0.2.79/src/convert/closures.rs:86:57                                            
warning: transmute to `&mut dyn core::ops::FnMut() -> R` which has an undefined layout            
   --> src/convert/closures.rs:86:57
    |
86  |                   let f: &mut dyn FnMut($($var),*) -> R = mem::transmute((a, b));
    |                                                           ^^^^^^^^^^^^^^^^^^^^^^
...
111 | / stack_closures! {
112 | |     (0 invoke0 invoke0_mut)
113 | |     (1 invoke1 invoke1_mut A)
114 | |     (2 invoke2 invoke2_mut A B)
...   |
120 | |     (8 invoke8 invoke8_mut A B C D E F G H)
121 | | }
    | |_- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `stack_closures` (in Nightly builds, run with -Z macro-backtrace for more info)


---> wasm-bindgen-0.2.79/src/convert/closures.rs:19:50                                            
warning: transmute from `&dyn core::ops::Fn(A) -> R` which has an undefined layout                
   --> src/convert/closures.rs:19:50
    |
19  |                       let (a, b): (usize, usize) = mem::transmute(self);
    |                                                    ^^^^^^^^^^^^^^^^^^^^
...
111 | / stack_closures! {
112 | |     (0 invoke0 invoke0_mut)
113 | |     (1 invoke1 invoke1_mut A)
114 | |     (2 invoke2 invoke2_mut A B)
...   |
120 | |     (8 invoke8 invoke8_mut A B C D E F G H)
121 | | }
    | |_- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `stack_closures` (in Nightly builds, run with -Z macro-backtrace for more info)


---> wasm-bindgen-0.2.79/src/convert/closures.rs:37:50                                            
warning: transmute to `&dyn core::ops::Fn(A) -> R` which has an undefined layout                  
   --> src/convert/closures.rs:37:50
    |
37  |                   let f: &dyn Fn($($var),*) -> R = mem::transmute((a, b));
    |                                                    ^^^^^^^^^^^^^^^^^^^^^^
...
111 | / stack_closures! {
112 | |     (0 invoke0 invoke0_mut)
113 | |     (1 invoke1 invoke1_mut A)
114 | |     (2 invoke2 invoke2_mut A B)
...   |
120 | |     (8 invoke8 invoke8_mut A B C D E F G H)
121 | | }
    | |_- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `stack_closures` (in Nightly builds, run with -Z macro-backtrace for more info)


---> wasm-bindgen-0.2.79/src/convert/closures.rs:68:50                                            
warning: transmute from `&mut dyn core::ops::FnMut(A) -> R` which has an undefined layout         
   --> src/convert/closures.rs:68:50
    |
68  |                       let (a, b): (usize, usize) = mem::transmute(self);
    |                                                    ^^^^^^^^^^^^^^^^^^^^
...
111 | / stack_closures! {
112 | |     (0 invoke0 invoke0_mut)
113 | |     (1 invoke1 invoke1_mut A)
114 | |     (2 invoke2 invoke2_mut A B)
...   |
120 | |     (8 invoke8 invoke8_mut A B C D E F G H)
121 | | }
    | |_- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `stack_closures` (in Nightly builds, run with -Z macro-backtrace for more info)


---> wasm-bindgen-0.2.79/src/convert/closures.rs:86:57                                            
warning: transmute to `&mut dyn core::ops::FnMut(A) -> R` which has an undefined layout           
   --> src/convert/closures.rs:86:57
    |
86  |                   let f: &mut dyn FnMut($($var),*) -> R = mem::transmute((a, b));
    |                                                           ^^^^^^^^^^^^^^^^^^^^^^
...
111 | / stack_closures! {
112 | |     (0 invoke0 invoke0_mut)
113 | |     (1 invoke1 invoke1_mut A)
114 | |     (2 invoke2 invoke2_mut A B)
...   |
120 | |     (8 invoke8 invoke8_mut A B C D E F G H)
121 | | }
    | |_- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `stack_closures` (in Nightly builds, run with -Z macro-backtrace for more info)


---> wasm-bindgen-0.2.79/src/convert/closures.rs:19:50                                            
warning: transmute from `&dyn core::ops::Fn(A, B) -> R` which has an undefined layout             
   --> src/convert/closures.rs:19:50
    |
19  |                       let (a, b): (usize, usize) = mem::transmute(self);
    |                                                    ^^^^^^^^^^^^^^^^^^^^
...
111 | / stack_closures! {
112 | |     (0 invoke0 invoke0_mut)
113 | |     (1 invoke1 invoke1_mut A)
114 | |     (2 invoke2 invoke2_mut A B)
...   |
120 | |     (8 invoke8 invoke8_mut A B C D E F G H)
121 | | }
    | |_- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `stack_closures` (in Nightly builds, run with -Z macro-backtrace for more info)


---> wasm-bindgen-0.2.79/src/convert/closures.rs:37:50                                            
warning: transmute to `&dyn core::ops::Fn(A, B) -> R` which has an undefined layout               
   --> src/convert/closures.rs:37:50
    |
37  |                   let f: &dyn Fn($($var),*) -> R = mem::transmute((a, b));
    |                                                    ^^^^^^^^^^^^^^^^^^^^^^
...
111 | / stack_closures! {
112 | |     (0 invoke0 invoke0_mut)
113 | |     (1 invoke1 invoke1_mut A)
114 | |     (2 invoke2 invoke2_mut A B)
...   |
120 | |     (8 invoke8 invoke8_mut A B C D E F G H)
121 | | }
    | |_- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `stack_closures` (in Nightly builds, run with -Z macro-backtrace for more info)


---> wasm-bindgen-0.2.79/src/convert/closures.rs:68:50                                            
warning: transmute from `&mut dyn core::ops::FnMut(A, B) -> R` which has an undefined layout      
   --> src/convert/closures.rs:68:50
    |
68  |                       let (a, b): (usize, usize) = mem::transmute(self);
    |                                                    ^^^^^^^^^^^^^^^^^^^^
...
111 | / stack_closures! {
112 | |     (0 invoke0 invoke0_mut)
113 | |     (1 invoke1 invoke1_mut A)
114 | |     (2 invoke2 invoke2_mut A B)
...   |
120 | |     (8 invoke8 invoke8_mut A B C D E F G H)
121 | | }
    | |_- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `stack_closures` (in Nightly builds, run with -Z macro-backtrace for more info)


---> wasm-bindgen-0.2.79/src/convert/closures.rs:86:57                                            
warning: transmute to `&mut dyn core::ops::FnMut(A, B) -> R` which has an undefined layout        
   --> src/convert/closures.rs:86:57
    |
86  |                   let f: &mut dyn FnMut($($var),*) -> R = mem::transmute((a, b));
    |                                                           ^^^^^^^^^^^^^^^^^^^^^^
...
111 | / stack_closures! {
112 | |     (0 invoke0 invoke0_mut)
113 | |     (1 invoke1 invoke1_mut A)
114 | |     (2 invoke2 invoke2_mut A B)
...   |
120 | |     (8 invoke8 invoke8_mut A B C D E F G H)
121 | | }
    | |_- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `stack_closures` (in Nightly builds, run with -Z macro-backtrace for more info)


---> wasm-bindgen-0.2.79/src/convert/closures.rs:19:50                                            
warning: transmute from `&dyn core::ops::Fn(A, B, C) -> R` which has an undefined layout          
   --> src/convert/closures.rs:19:50
    |
19  |                       let (a, b): (usize, usize) = mem::transmute(self);
    |                                                    ^^^^^^^^^^^^^^^^^^^^
...
111 | / stack_closures! {
112 | |     (0 invoke0 invoke0_mut)
113 | |     (1 invoke1 invoke1_mut A)
114 | |     (2 invoke2 invoke2_mut A B)
...   |
120 | |     (8 invoke8 invoke8_mut A B C D E F G H)
121 | | }
    | |_- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `stack_closures` (in Nightly builds, run with -Z macro-backtrace for more info)


---> wasm-bindgen-0.2.79/src/convert/closures.rs:37:50                                            
warning: transmute to `&dyn core::ops::Fn(A, B, C) -> R` which has an undefined layout            
   --> src/convert/closures.rs:37:50
    |
37  |                   let f: &dyn Fn($($var),*) -> R = mem::transmute((a, b));
    |                                                    ^^^^^^^^^^^^^^^^^^^^^^
...
111 | / stack_closures! {
112 | |     (0 invoke0 invoke0_mut)
113 | |     (1 invoke1 invoke1_mut A)
114 | |     (2 invoke2 invoke2_mut A B)
...   |
120 | |     (8 invoke8 invoke8_mut A B C D E F G H)
121 | | }
    | |_- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `stack_closures` (in Nightly builds, run with -Z macro-backtrace for more info)


---> wasm-bindgen-0.2.79/src/convert/closures.rs:68:50                                            
warning: transmute from `&mut dyn core::ops::FnMut(A, B, C) -> R` which has an undefined layout   
   --> src/convert/closures.rs:68:50
    |
68  |                       let (a, b): (usize, usize) = mem::transmute(self);
    |                                                    ^^^^^^^^^^^^^^^^^^^^
...
111 | / stack_closures! {
112 | |     (0 invoke0 invoke0_mut)
113 | |     (1 invoke1 invoke1_mut A)
114 | |     (2 invoke2 invoke2_mut A B)
...   |
120 | |     (8 invoke8 invoke8_mut A B C D E F G H)
121 | | }
    | |_- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `stack_closures` (in Nightly builds, run with -Z macro-backtrace for more info)


---> wasm-bindgen-0.2.79/src/convert/closures.rs:86:57                                            
warning: transmute to `&mut dyn core::ops::FnMut(A, B, C) -> R` which has an undefined layout     
   --> src/convert/closures.rs:86:57
    |
86  |                   let f: &mut dyn FnMut($($var),*) -> R = mem::transmute((a, b));
    |                                                           ^^^^^^^^^^^^^^^^^^^^^^
...
111 | / stack_closures! {
112 | |     (0 invoke0 invoke0_mut)
113 | |     (1 invoke1 invoke1_mut A)
114 | |     (2 invoke2 invoke2_mut A B)
...   |
120 | |     (8 invoke8 invoke8_mut A B C D E F G H)
121 | | }
    | |_- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `stack_closures` (in Nightly builds, run with -Z macro-backtrace for more info)


---> wasm-bindgen-0.2.79/src/convert/closures.rs:19:50                                            
warning: transmute from `&dyn core::ops::Fn(A, B, C, D) -> R` which has an undefined layout       
   --> src/convert/closures.rs:19:50
    |
19  |                       let (a, b): (usize, usize) = mem::transmute(self);
    |                                                    ^^^^^^^^^^^^^^^^^^^^
...
111 | / stack_closures! {
112 | |     (0 invoke0 invoke0_mut)
113 | |     (1 invoke1 invoke1_mut A)
114 | |     (2 invoke2 invoke2_mut A B)
...   |
120 | |     (8 invoke8 invoke8_mut A B C D E F G H)
121 | | }
    | |_- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `stack_closures` (in Nightly builds, run with -Z macro-backtrace for more info)


---> wasm-bindgen-0.2.79/src/convert/closures.rs:37:50                                            
warning: transmute to `&dyn core::ops::Fn(A, B, C, D) -> R` which has an undefined layout         
   --> src/convert/closures.rs:37:50
    |
37  |                   let f: &dyn Fn($($var),*) -> R = mem::transmute((a, b));
    |                                                    ^^^^^^^^^^^^^^^^^^^^^^
...
111 | / stack_closures! {
112 | |     (0 invoke0 invoke0_mut)
113 | |     (1 invoke1 invoke1_mut A)
114 | |     (2 invoke2 invoke2_mut A B)
...   |
120 | |     (8 invoke8 invoke8_mut A B C D E F G H)
121 | | }
    | |_- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `stack_closures` (in Nightly builds, run with -Z macro-backtrace for more info)


---> wasm-bindgen-0.2.79/src/convert/closures.rs:68:50                                            
warning: transmute from `&mut dyn core::ops::FnMut(A, B, C, D) -> R` which has an undefined layout
   --> src/convert/closures.rs:68:50
    |
68  |                       let (a, b): (usize, usize) = mem::transmute(self);
    |                                                    ^^^^^^^^^^^^^^^^^^^^
...
111 | / stack_closures! {
112 | |     (0 invoke0 invoke0_mut)
113 | |     (1 invoke1 invoke1_mut A)
114 | |     (2 invoke2 invoke2_mut A B)
...   |
120 | |     (8 invoke8 invoke8_mut A B C D E F G H)
121 | | }
    | |_- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `stack_closures` (in Nightly builds, run with -Z macro-backtrace for more info)


---> wasm-bindgen-0.2.79/src/convert/closures.rs:86:57                                            
warning: transmute to `&mut dyn core::ops::FnMut(A, B, C, D) -> R` which has an undefined layout  
   --> src/convert/closures.rs:86:57
    |
86  |                   let f: &mut dyn FnMut($($var),*) -> R = mem::transmute((a, b));
    |                                                           ^^^^^^^^^^^^^^^^^^^^^^
...
111 | / stack_closures! {
112 | |     (0 invoke0 invoke0_mut)
113 | |     (1 invoke1 invoke1_mut A)
114 | |     (2 invoke2 invoke2_mut A B)
...   |
120 | |     (8 invoke8 invoke8_mut A B C D E F G H)
121 | | }
    | |_- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `stack_closures` (in Nightly builds, run with -Z macro-backtrace for more info)


---> wasm-bindgen-0.2.79/src/convert/closures.rs:19:50                                            
warning: transmute from `&dyn core::ops::Fn(A, B, C, D, E) -> R` which has an undefined layout    
   --> src/convert/closures.rs:19:50
    |
19  |                       let (a, b): (usize, usize) = mem::transmute(self);
    |                                                    ^^^^^^^^^^^^^^^^^^^^
...
111 | / stack_closures! {
112 | |     (0 invoke0 invoke0_mut)
113 | |     (1 invoke1 invoke1_mut A)
114 | |     (2 invoke2 invoke2_mut A B)
...   |
120 | |     (8 invoke8 invoke8_mut A B C D E F G H)
121 | | }
    | |_- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `stack_closures` (in Nightly builds, run with -Z macro-backtrace for more info)


---> wasm-bindgen-0.2.79/src/convert/closures.rs:37:50                                            
warning: transmute to `&dyn core::ops::Fn(A, B, C, D, E) -> R` which has an undefined layout      
   --> src/convert/closures.rs:37:50
    |
37  |                   let f: &dyn Fn($($var),*) -> R = mem::transmute((a, b));
    |                                                    ^^^^^^^^^^^^^^^^^^^^^^
...
111 | / stack_closures! {
112 | |     (0 invoke0 invoke0_mut)
113 | |     (1 invoke1 invoke1_mut A)
114 | |     (2 invoke2 invoke2_mut A B)
...   |
120 | |     (8 invoke8 invoke8_mut A B C D E F G H)
121 | | }
    | |_- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `stack_closures` (in Nightly builds, run with -Z macro-backtrace for more info)


---> wasm-bindgen-0.2.79/src/convert/closures.rs:68:50                                            
warning: transmute from `&mut dyn core::ops::FnMut(A, B, C, D, E) -> R` which has an undefined layout
   --> src/convert/closures.rs:68:50
    |
68  |                       let (a, b): (usize, usize) = mem::transmute(self);
    |                                                    ^^^^^^^^^^^^^^^^^^^^
...
111 | / stack_closures! {
112 | |     (0 invoke0 invoke0_mut)
113 | |     (1 invoke1 invoke1_mut A)
114 | |     (2 invoke2 invoke2_mut A B)
...   |
120 | |     (8 invoke8 invoke8_mut A B C D E F G H)
121 | | }
    | |_- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `stack_closures` (in Nightly builds, run with -Z macro-backtrace for more info)


---> wasm-bindgen-0.2.79/src/convert/closures.rs:86:57                                            
warning: transmute to `&mut dyn core::ops::FnMut(A, B, C, D, E) -> R` which has an undefined layout
   --> src/convert/closures.rs:86:57
    |
86  |                   let f: &mut dyn FnMut($($var),*) -> R = mem::transmute((a, b));
    |                                                           ^^^^^^^^^^^^^^^^^^^^^^
...
111 | / stack_closures! {
112 | |     (0 invoke0 invoke0_mut)
113 | |     (1 invoke1 invoke1_mut A)
114 | |     (2 invoke2 invoke2_mut A B)
...   |
120 | |     (8 invoke8 invoke8_mut A B C D E F G H)
121 | | }
    | |_- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `stack_closures` (in Nightly builds, run with -Z macro-backtrace for more info)


---> wasm-bindgen-0.2.79/src/convert/closures.rs:19:50                                            
warning: transmute from `&dyn core::ops::Fn(A, B, C, D, E, F) -> R` which has an undefined layout 
   --> src/convert/closures.rs:19:50
    |
19  |                       let (a, b): (usize, usize) = mem::transmute(self);
    |                                                    ^^^^^^^^^^^^^^^^^^^^
...
111 | / stack_closures! {
112 | |     (0 invoke0 invoke0_mut)
113 | |     (1 invoke1 invoke1_mut A)
114 | |     (2 invoke2 invoke2_mut A B)
...   |
120 | |     (8 invoke8 invoke8_mut A B C D E F G H)
121 | | }
    | |_- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `stack_closures` (in Nightly builds, run with -Z macro-backtrace for more info)


---> wasm-bindgen-0.2.79/src/convert/closures.rs:37:50                                            
warning: transmute to `&dyn core::ops::Fn(A, B, C, D, E, F) -> R` which has an undefined layout   
   --> src/convert/closures.rs:37:50
    |
37  |                   let f: &dyn Fn($($var),*) -> R = mem::transmute((a, b));
    |                                                    ^^^^^^^^^^^^^^^^^^^^^^
...
111 | / stack_closures! {
112 | |     (0 invoke0 invoke0_mut)
113 | |     (1 invoke1 invoke1_mut A)
114 | |     (2 invoke2 invoke2_mut A B)
...   |
120 | |     (8 invoke8 invoke8_mut A B C D E F G H)
121 | | }
    | |_- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `stack_closures` (in Nightly builds, run with -Z macro-backtrace for more info)


---> wasm-bindgen-0.2.79/src/convert/closures.rs:68:50                                            
warning: transmute from `&mut dyn core::ops::FnMut(A, B, C, D, E, F) -> R` which has an undefined layout
   --> src/convert/closures.rs:68:50
    |
68  |                       let (a, b): (usize, usize) = mem::transmute(self);
    |                                                    ^^^^^^^^^^^^^^^^^^^^
...
111 | / stack_closures! {
112 | |     (0 invoke0 invoke0_mut)
113 | |     (1 invoke1 invoke1_mut A)
114 | |     (2 invoke2 invoke2_mut A B)
...   |
120 | |     (8 invoke8 invoke8_mut A B C D E F G H)
121 | | }
    | |_- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `stack_closures` (in Nightly builds, run with -Z macro-backtrace for more info)


---> wasm-bindgen-0.2.79/src/convert/closures.rs:86:57                                            
warning: transmute to `&mut dyn core::ops::FnMut(A, B, C, D, E, F) -> R` which has an undefined layout
   --> src/convert/closures.rs:86:57
    |
86  |                   let f: &mut dyn FnMut($($var),*) -> R = mem::transmute((a, b));
    |                                                           ^^^^^^^^^^^^^^^^^^^^^^
...
111 | / stack_closures! {
112 | |     (0 invoke0 invoke0_mut)
113 | |     (1 invoke1 invoke1_mut A)
114 | |     (2 invoke2 invoke2_mut A B)
...   |
120 | |     (8 invoke8 invoke8_mut A B C D E F G H)
121 | | }
    | |_- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `stack_closures` (in Nightly builds, run with -Z macro-backtrace for more info)


---> wasm-bindgen-0.2.79/src/convert/closures.rs:19:50                                            
warning: transmute from `&dyn core::ops::Fn(A, B, C, D, E, F, G) -> R` which has an undefined layout
   --> src/convert/closures.rs:19:50
    |
19  |                       let (a, b): (usize, usize) = mem::transmute(self);
    |                                                    ^^^^^^^^^^^^^^^^^^^^
...
111 | / stack_closures! {
112 | |     (0 invoke0 invoke0_mut)
113 | |     (1 invoke1 invoke1_mut A)
114 | |     (2 invoke2 invoke2_mut A B)
...   |
120 | |     (8 invoke8 invoke8_mut A B C D E F G H)
121 | | }
    | |_- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `stack_closures` (in Nightly builds, run with -Z macro-backtrace for more info)


---> wasm-bindgen-0.2.79/src/convert/closures.rs:37:50                                            
warning: transmute to `&dyn core::ops::Fn(A, B, C, D, E, F, G) -> R` which has an undefined layout
   --> src/convert/closures.rs:37:50
    |
37  |                   let f: &dyn Fn($($var),*) -> R = mem::transmute((a, b));
    |                                                    ^^^^^^^^^^^^^^^^^^^^^^
...
111 | / stack_closures! {
112 | |     (0 invoke0 invoke0_mut)
113 | |     (1 invoke1 invoke1_mut A)
114 | |     (2 invoke2 invoke2_mut A B)
...   |
120 | |     (8 invoke8 invoke8_mut A B C D E F G H)
121 | | }
    | |_- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `stack_closures` (in Nightly builds, run with -Z macro-backtrace for more info)


---> wasm-bindgen-0.2.79/src/convert/closures.rs:68:50                                            
warning: transmute from `&mut dyn core::ops::FnMut(A, B, C, D, E, F, G) -> R` which has an undefined layout
   --> src/convert/closures.rs:68:50
    |
68  |                       let (a, b): (usize, usize) = mem::transmute(self);
    |                                                    ^^^^^^^^^^^^^^^^^^^^
...
111 | / stack_closures! {
112 | |     (0 invoke0 invoke0_mut)
113 | |     (1 invoke1 invoke1_mut A)
114 | |     (2 invoke2 invoke2_mut A B)
...   |
120 | |     (8 invoke8 invoke8_mut A B C D E F G H)
121 | | }
    | |_- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `stack_closures` (in Nightly builds, run with -Z macro-backtrace for more info)


---> wasm-bindgen-0.2.79/src/convert/closures.rs:86:57                                            
warning: transmute to `&mut dyn core::ops::FnMut(A, B, C, D, E, F, G) -> R` which has an undefined layout
   --> src/convert/closures.rs:86:57
    |
86  |                   let f: &mut dyn FnMut($($var),*) -> R = mem::transmute((a, b));
    |                                                           ^^^^^^^^^^^^^^^^^^^^^^
...
111 | / stack_closures! {
112 | |     (0 invoke0 invoke0_mut)
113 | |     (1 invoke1 invoke1_mut A)
114 | |     (2 invoke2 invoke2_mut A B)
...   |
120 | |     (8 invoke8 invoke8_mut A B C D E F G H)
121 | | }
    | |_- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `stack_closures` (in Nightly builds, run with -Z macro-backtrace for more info)


---> wasm-bindgen-0.2.79/src/convert/closures.rs:19:50                                            
warning: transmute from `&dyn core::ops::Fn(A, B, C, D, E, F, G, H) -> R` which has an undefined layout
   --> src/convert/closures.rs:19:50
    |
19  |                       let (a, b): (usize, usize) = mem::transmute(self);
    |                                                    ^^^^^^^^^^^^^^^^^^^^
...
111 | / stack_closures! {
112 | |     (0 invoke0 invoke0_mut)
113 | |     (1 invoke1 invoke1_mut A)
114 | |     (2 invoke2 invoke2_mut A B)
...   |
120 | |     (8 invoke8 invoke8_mut A B C D E F G H)
121 | | }
    | |_- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `stack_closures` (in Nightly builds, run with -Z macro-backtrace for more info)


---> wasm-bindgen-0.2.79/src/convert/closures.rs:37:50                                            
warning: transmute to `&dyn core::ops::Fn(A, B, C, D, E, F, G, H) -> R` which has an undefined layout
   --> src/convert/closures.rs:37:50
    |
37  |                   let f: &dyn Fn($($var),*) -> R = mem::transmute((a, b));
    |                                                    ^^^^^^^^^^^^^^^^^^^^^^
...
111 | / stack_closures! {
112 | |     (0 invoke0 invoke0_mut)
113 | |     (1 invoke1 invoke1_mut A)
114 | |     (2 invoke2 invoke2_mut A B)
...   |
120 | |     (8 invoke8 invoke8_mut A B C D E F G H)
121 | | }
    | |_- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `stack_closures` (in Nightly builds, run with -Z macro-backtrace for more info)


---> wasm-bindgen-0.2.79/src/convert/closures.rs:68:50                                            
warning: transmute from `&mut dyn core::ops::FnMut(A, B, C, D, E, F, G, H) -> R` which has an undefined layout
   --> src/convert/closures.rs:68:50
    |
68  |                       let (a, b): (usize, usize) = mem::transmute(self);
    |                                                    ^^^^^^^^^^^^^^^^^^^^
...
111 | / stack_closures! {
112 | |     (0 invoke0 invoke0_mut)
113 | |     (1 invoke1 invoke1_mut A)
114 | |     (2 invoke2 invoke2_mut A B)
...   |
120 | |     (8 invoke8 invoke8_mut A B C D E F G H)
121 | | }
    | |_- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `stack_closures` (in Nightly builds, run with -Z macro-backtrace for more info)


---> wasm-bindgen-0.2.79/src/convert/closures.rs:86:57                                            
warning: transmute to `&mut dyn core::ops::FnMut(A, B, C, D, E, F, G, H) -> R` which has an undefined layout
   --> src/convert/closures.rs:86:57
    |
86  |                   let f: &mut dyn FnMut($($var),*) -> R = mem::transmute((a, b));
    |                                                           ^^^^^^^^^^^^^^^^^^^^^^
...
111 | / stack_closures! {
112 | |     (0 invoke0 invoke0_mut)
113 | |     (1 invoke1 invoke1_mut A)
114 | |     (2 invoke2 invoke2_mut A B)
...   |
120 | |     (8 invoke8 invoke8_mut A B C D E F G H)
121 | | }
    | |_- in this macro invocation
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr
    = note: this warning originates in the macro `stack_closures` (in Nightly builds, run with -Z macro-backtrace for more info)


---> wasm-bindgen-0.2.79/src/convert/closures.rs:132:42                                           
warning: transmute from `&dyn for<'r> core::ops::Fn(&'r A) -> R` which has an undefined layout    
   --> src/convert/closures.rs:132:42
    |
132 |             let (a, b): (usize, usize) = mem::transmute(self);
    |                                          ^^^^^^^^^^^^^^^^^^^^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr


---> wasm-bindgen-0.2.79/src/convert/closures.rs:153:35                                           
warning: transmute to `&dyn for<'r> core::ops::Fn(&'r A) -> R` which has an undefined layout      
   --> src/convert/closures.rs:153:35
    |
153 |         let f: &dyn Fn(&A) -> R = mem::transmute((a, b));
    |                                   ^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr


---> wasm-bindgen-0.2.79/src/convert/closures.rs:184:42                                           
warning: transmute from `&mut dyn for<'r> core::ops::FnMut(&'r A) -> R` which has an undefined layout
   --> src/convert/closures.rs:184:42
    |
184 |             let (a, b): (usize, usize) = mem::transmute(self);
    |                                          ^^^^^^^^^^^^^^^^^^^^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr


---> wasm-bindgen-0.2.79/src/convert/closures.rs:205:42                                           
warning: transmute to `&mut dyn for<'r> core::ops::FnMut(&'r A) -> R` which has an undefined layout
   --> src/convert/closures.rs:205:42
    |
205 |         let f: &mut dyn FnMut(&A) -> R = mem::transmute((a, b));
    |                                          ^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#transmute_undefined_repr

@llogiq
Copy link
Contributor

llogiq commented Mar 3, 2022

The criterion error seems to indicate that the lint fails to apply type adjustments – in this case from &Vec<T> to &[T] as indicated by the first generic argument of the transmute call. If I replace v (which is of type &Vec<_> by &v[..], the lint no longer fires.

@Manishearth
Copy link
Member Author

sounds like we should at the very least be using the inferred or provided generic arguments of transmute instead of reading the expression types

@llogiq
Copy link
Contributor

llogiq commented Mar 3, 2022

I opened #8501 to track this.

@Jarcho
Copy link
Contributor

Jarcho commented Mar 3, 2022 •
edited
Loading

Just went through all them.

  • cgmath is relying on the order of tuple fields.
  • criterion is a bug. Probably used expr_ty instead of expr_ty_adjusted.
  • iovec is relying on the order of slice pointers.
  • nalgebra is fine, it's checking the TypeId of the generic types first.
  • parity-scale-codec is the same as nalgebra.
  • prettytable is between two non-repr(C) types.
  • state is fine. It doesn't read either of the fields, but the names for the fields are useless.
  • wasm-bindgen looks to be the same as state, but using tuples instead of a struct.

For both wasm-bindgen and state would not have triggered if they used [usize; 2]. (usize, usize) could be allowed here as well. state uses a struct so there's nothing to really do there.

parity-scale-codec really should be using a trait instead of transmuting. nalgebra could probably do that, but would be more complicated. (this would need specialization to work, so not practical)

@Jarcho
Copy link
Contributor

Jarcho commented Mar 17, 2022

With the recent changes both nalgebra and state are still false positives.

  • nalgebra still needs to be fixed not to lint.
  • state I don't think should be fixed given that the fields are named. Were the struct to be declared as #[repr(C)] struct AnyObject([usize;2]) then it would not lint.

@Jarcho
Copy link
Contributor

Jarcho commented Aug 7, 2022 •
edited
Loading

Results on running on more crates https://gist.github.com/Jarcho/6890efe9c9f051aef943f1dedbbbb02d

True positives

*vsdb-0.45.2: Transmute between different Vec instances
*sxd-document-0.3.2: Relies on the order of &str
*utf8-cstr-0.1.6: Relies on the order of &str
*hyper-old-types-0.11.0: Relies on the order of &dyn Trait
*serde_v8-0.56.0: Relies on the order of non-repr(C) structs
*query_interface-0.3.5: Relies on the order of &dyn Trait
*solana_rbpf-0.2.31: Relies on the order of &dyn Trait and the vtable layout
*fontdue-0.7.2: Relies on the layout of tuples (f32, f32, f32, f32)
*str-buf-3.0.1: Relies on the &[u8], but it at least has a test for it. Not guarenteed on the target platform, but better than nothing
*rusty_v8-0.32.1: Relies on the layout of &dyn Trait. Has a runtime assert checking the layout.
*iovec-0.1.4: Relies on the layout of &[u8]
*libpulse-binding-2.26.0: Relies on the layout of a non-repr(C) struct.
*adapton-0.3.31: Relies on the layout of &dyn Trait. It also manages to leak memory by transmuting Box<&dyn Trait> into &Box<U>, with no way to deallocate the original box.
*v8-0.48.0: same as rusty_v8

False positives

*parity-scale-codec-3.1.5: Type parameter -> concrete type
*lodepng-3.7.0: Horrible &mut *mut u8 -> &mut &mut Vec which is un-erasing the type. (Won't lint with #9287)
*skia-safe: Transmutes between &dyn Trait and a struct, but doesn't read the fields.
*state-0.5.3: Same as skia-safe. Uses a custom struct but doesn't read the fields.
*fluent-bundle-0.15.2: Cast NonNull<u8> from alloc to `NonNull. (Fixed with #9287)

Most of those are related to fat pointer layouts, which as far as I know are still formally undefined. The Unsafe Code Guidelines Working Group has them defined well enough for most of these transmutes, but should that be considered enough to ignore these cases?

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Assignees
No one assigned
Labels
C-bug Category: Clippy is not doing the correct thing E-help-wanted Call for participation: Help is requested to fix this issue.
Projects
None yet
Milestone
No milestone
Development

No branches or pull requests
3 participants
@Manishearth @llogiq @Jarcho