…ilee

CFI: Skip non-passed arguments

Rust will occasionally rely on fn((), X) -> Y being compatible with fn(X) -> Y, since () is a non-passed argument. Relax CFI by choosing not to encode non-passed arguments.

This PR was split off from rust-lang#121962 as part of fixing the larger vtable compatibility issues.

r? `@workingjubilee`

…ilee

CFI: Skip non-passed arguments

Rust will occasionally rely on fn((), X) -> Y being compatible with fn(X) -> Y, since () is a non-passed argument. Relax CFI by choosing not to encode non-passed arguments.

This PR was split off from rust-lang#121962 as part of fixing the larger vtable compatibility issues.

r? ``@workingjubilee``

CFI: Skip non-passed arguments

Rust will occasionally rely on fn((), X) -> Y being compatible with fn(X) -> Y, since () is a non-passed argument. Relax CFI by choosing not to encode non-passed arguments.

This PR was split off from rust-lang#121962 as part of fixing the larger vtable compatibility issues.

r? `@workingjubilee`

CFI: Skip non-passed arguments

Rust will occasionally rely on fn((), X) -> Y being compatible with fn(X) -> Y, since () is a non-passed argument. Relax CFI by choosing not to encode non-passed arguments.

This PR was split off from rust-lang#121962 as part of fixing the larger vtable compatibility issues.

r? `@workingjubilee`

…, r=workingjubilee

CFI: Support self_cell-like recursion

Current `transform_ty` attempts to avoid cycles when normalizing `#[repr(transparent)]` types to their interior, but runs afoul of this pattern used in `self_cell`:

```
struct X<T> {
  x: u8,
  p: PhantomData<T>,
}

 #[repr(transparent)]
struct Y(X<Y>);
```

When attempting to normalize Y, it will still cycle indefinitely. By using a types-visited list, this will instead get expanded exactly one layer deep to X<Y>, and then stop, not attempting to normalize `Y` any further.

This PR was split off from rust-lang#121962 as part of fixing the larger vtable compatibility issues.

r? `@workingjubilee`

…, r=workingjubilee

CFI: Support self_cell-like recursion

Current `transform_ty` attempts to avoid cycles when normalizing `#[repr(transparent)]` types to their interior, but runs afoul of this pattern used in `self_cell`:

```
struct X<T> {
  x: u8,
  p: PhantomData<T>,
}

 #[repr(transparent)]
struct Y(X<Y>);
```

When attempting to normalize Y, it will still cycle indefinitely. By using a types-visited list, this will instead get expanded exactly one layer deep to X<Y>, and then stop, not attempting to normalize `Y` any further.

This PR was split off from rust-lang#121962 as part of fixing the larger vtable compatibility issues.

r? ``@workingjubilee``

…, r=workingjubilee

CFI: Support self_cell-like recursion

Current `transform_ty` attempts to avoid cycles when normalizing `#[repr(transparent)]` types to their interior, but runs afoul of this pattern used in `self_cell`:

```
struct X<T> {
  x: u8,
  p: PhantomData<T>,
}

 #[repr(transparent)]
struct Y(X<Y>);
```

When attempting to normalize Y, it will still cycle indefinitely. By using a types-visited list, this will instead get expanded exactly one layer deep to X<Y>, and then stop, not attempting to normalize `Y` any further.

This PR was split off from rust-lang#121962 as part of fixing the larger vtable compatibility issues.

r? ```@workingjubilee```

…, r=workingjubilee

CFI: Support self_cell-like recursion

Current `transform_ty` attempts to avoid cycles when normalizing `#[repr(transparent)]` types to their interior, but runs afoul of this pattern used in `self_cell`:

```
struct X<T> {
  x: u8,
  p: PhantomData<T>,
}

 #[repr(transparent)]
struct Y(X<Y>);
```

When attempting to normalize Y, it will still cycle indefinitely. By using a types-visited list, this will instead get expanded exactly one layer deep to X<Y>, and then stop, not attempting to normalize `Y` any further.

This PR was split off from rust-lang#121962 as part of fixing the larger vtable compatibility issues.

r? ````@workingjubilee````

…, r=workingjubilee

CFI: Support self_cell-like recursion

Current `transform_ty` attempts to avoid cycles when normalizing `#[repr(transparent)]` types to their interior, but runs afoul of this pattern used in `self_cell`:

```
struct X<T> {
  x: u8,
  p: PhantomData<T>,
}

 #[repr(transparent)]
struct Y(X<Y>);
```

When attempting to normalize Y, it will still cycle indefinitely. By using a types-visited list, this will instead get expanded exactly one layer deep to X<Y>, and then stop, not attempting to normalize `Y` any further.

This PR was split off from rust-lang#121962 as part of fixing the larger vtable compatibility issues.

r? `````@workingjubilee`````

…, r=workingjubilee

CFI: Support self_cell-like recursion

Current `transform_ty` attempts to avoid cycles when normalizing `#[repr(transparent)]` types to their interior, but runs afoul of this pattern used in `self_cell`:

```
struct X<T> {
  x: u8,
  p: PhantomData<T>,
}

 #[repr(transparent)]
struct Y(X<Y>);
```

When attempting to normalize Y, it will still cycle indefinitely. By using a types-visited list, this will instead get expanded exactly one layer deep to X<Y>, and then stop, not attempting to normalize `Y` any further.

This PR was split off from rust-lang#121962 as part of fixing the larger vtable compatibility issues.

r? ``````@workingjubilee``````

Rollup merge of rust-lang#122875 - maurer:cfi-transparent-termination, r=workingjubilee

CFI: Support self_cell-like recursion

Current `transform_ty` attempts to avoid cycles when normalizing `#[repr(transparent)]` types to their interior, but runs afoul of this pattern used in `self_cell`:

```
struct X<T> {
  x: u8,
  p: PhantomData<T>,
}

 #[repr(transparent)]
struct Y(X<Y>);
```

When attempting to normalize Y, it will still cycle indefinitely. By using a types-visited list, this will instead get expanded exactly one layer deep to X<Y>, and then stop, not attempting to normalize `Y` any further.

This PR was split off from rust-lang#121962 as part of fixing the larger vtable compatibility issues.

r? ``````@workingjubilee``````

…, r=workingjubilee

CFI: Support self_cell-like recursion

Current `transform_ty` attempts to avoid cycles when normalizing `#[repr(transparent)]` types to their interior, but runs afoul of this pattern used in `self_cell`:

```
struct X<T> {
  x: u8,
  p: PhantomData<T>,
}

 #[repr(transparent)]
struct Y(X<Y>);
```

When attempting to normalize Y, it will still cycle indefinitely. By using a types-visited list, this will instead get expanded exactly one layer deep to X<Y>, and then stop, not attempting to normalize `Y` any further.

This PR was split off from rust-lang#121962 as part of fixing the larger vtable compatibility issues.

r? ``````@workingjubilee``````

Since we're now using an approach which is a variant of rust-lang#123082 (that
transforms closures into dynamic Fn traits but isolating it to the Fn
call methods only) instead of rust-lang#121962 or rust-lang#122573, skipping non-passed
arguments shouldn't be necessary KCFI anymore and we can claim back the
reduced granularity.

This reverts commit f2f0d25.

Since we're now using an approach which is a variant of rust-lang#123082 (that
transforms closures into dynamic Fn traits but isolating it to the Fn
call methods only) instead of rust-lang#121962 or rust-lang#122573, skipping non-passed
arguments shouldn't be necessary for KCFI anymore and we can claim back
the reduced granularity.

This reverts commit f2f0d25.

Since we're now using an approach which is a variant of rust-lang#123082 (that
transforms closures into dynamic Fn traits but isolating it to the Fn
call methods only) instead of rust-lang#121962 or rust-lang#122573, skipping non-passed
arguments shouldn't be necessary for KCFI anymore and we can claim back
the reduced granularity.

This reverts commit f2f0d25.