Introduce a minimum CGU size in non-incremental builds.
Because tiny CGUs slow down compilation *and* result in worse generated code.
r? `@wesleywiser`
Because tiny CGUs make compilation less efficient *and* result in worse
generated code.
We don't do this when the number of CGUs is explicitly given, because
there are times when the requested number is very important, as
described in some comments within the commit. So the commit also
introduces a `CodegenUnits` type that distinguishes between default
values and user-specified values.
This change has a roughly neutral effect on walltimes across the
rustc-perf benchmarks; there are some speedups and some slowdowns. But
it has significant wins for most other metrics on numerous benchmarks,
including instruction counts, cycles, binary size, and max-rss. It also
reduces parallelism, which is good for reducing jobserver competition
when multiple rustc processes are running at the same time. It's smaller
benchmarks that benefit the most; larger benchmarks already have CGUs
that are all larger than the minimum size.
Here are some example before/after CGU sizes for opt builds.
- html5ever
- CGUs: 16, mean size: 1196.1, sizes: [3908, 2992, 1706, 1652, 1572,
1136, 1045, 948, 946, 938, 579, 471, 443, 327, 286, 189]
- CGUs: 4, mean size: 4396.0, sizes: [6706, 3908, 3490, 3480]
- libc
- CGUs: 12, mean size: 35.3, sizes: [163, 93, 58, 53, 37, 8, 2 (x6)]
- CGUs: 1, mean size: 424.0, sizes: [424]
- tt-muncher
- CGUs: 5, mean size: 1819.4, sizes: [8508, 350, 198, 34, 7]
- CGUs: 1, mean size: 9075.0, sizes: [9075]
Note that CGUs of size 100,000+ aren't unusual in larger programs.
Make struct layout not depend on unsizeable tail
fixes (after backport) https://github.com/rust-lang/rust/issues/112048
Since unsizing `Ptr<Foo<T>>` -> `Ptr<Foo<U>` just copies the pointer and adds the metadata, the layout of `Foo` must not depend on niches in and alignment of the tail `T`.
Nominating for beta 1.71, because it will have this issue: `@rustbot` label beta-nominated
Ignore `core`, `alloc` and `test` tests that require unwinding on `-C panic=abort`
Some of the tests for `core` and `alloc` require unwinding through their use of `catch_unwind`. These tests fail when testing using `-C panic=abort` (in my case through a target without unwinding support, and `-Z panic-abort-tests`), while they should be ignored as they don't indicate a failure.
This PR marks all of these tests with this attribute:
```rust
#[cfg_attr(not(panic = "unwind"), ignore = "test requires unwinding support")]
```
I'm not aware of a way to test this on rust-lang/rust's CI, as we don't test any target with `-C panic=abort`, but I tested this locally on a Ferrocene target and it does indeed make the test suite pass.
Add MVP suggestion for `unsafe_op_in_unsafe_fn`
Rebase of https://github.com/rust-lang/rust/pull/99827
cc tracking issue https://github.com/rust-lang/rust/issues/71668
No real changes since the original PR, just migrated the new suggestion to use fluent messages and added a couple more testcases, AFAICT from the discussion there were no outstanding changes requested.
loongarch64-unknown-none*: Set default relocation model to static
This PR sets the default relocation model to `static` for `loongarch64-unknown-none*` targets. This change aims to streamline the development of the bare-metal project by removing the need for the executable program loader to implement relocation.
Suggest using `ptr::null_mut` when user provided `ptr::null` to a function expecting `ptr::null_mut`
```
error[E0308]: mismatched types
--> $DIR/ptr-null-mutability-suggestions.rs:9:24
|
LL | expecting_null_mut(ptr::null());
| ------------------ ^^^^^^^^^^^
| | |
| | types differ in mutability
| | help: consider using `core::ptr::null_mut` instead: `core::ptr::null_mut()`
| arguments to this function are incorrect
|
= note: expected raw pointer `*mut u8`
found raw pointer `*const _`
note: function defined here
--> $DIR/ptr-null-mutability-suggestions.rs:6:4
|
LL | fn expecting_null_mut(_: *mut u8) {}
| ^^^^^^^^^^^^^^^^^^ ----------
```
Closes#85184.
Dont compute `opt_suggest_box_span` span for TAIT
Fixes#112434
Also a couple more commits on top, pruning some dead code and fixing another weird suggestion encountered in the above issue.
iat selection: normalize self ty & completely erase bound vars
Erase bound vars (most notably late-bound regions) irrespective of their binding level instead of just at the innermost one.
Fixes#111404.
Instead of linking to the old Rust Reference site on static.rust-lang.org,
link to the current website doc.rust-lang.org/stable/reference instead in
diagnostic about incorrect literals.
Adjust span labels for `HIDDEN_GLOB_REEXPORTS`
Addresses https://github.com/rust-lang/rust/pull/111378#issuecomment-1581226063.
### Before This PR
The possibility that the private item comes before the glob re-export was not account for, causing the span label messages to say "but private item here shadows it" before "the name `Foo` in the type namespace is supposed to be publicly re-exported here".
### After This PR
```rust
warning: private item shadows public glob re-export
--> $DIR/hidden_glob_reexports.rs:9:5
|
LL | struct Foo;
| ^^^^^^^^^^^ the private item here shadows the name `Foo` in the type namespace
...
LL | pub use self::inner::*;
| -------------- but it is supposed to be publicly re-exported here
|
= note: `#[warn(hidden_glob_reexports)]` on by default
warning: private item shadows public glob re-export
--> $DIR/hidden_glob_reexports.rs:27:9
|
LL | pub use self::inner::*;
| -------------- the name `Foo` in the type namespace is supposed to be publicly re-exported here
LL |
LL | use self::other::Foo;
| ^^^^^^^^^^^^^^^^ but the private item here shadows it
```
Update field-offset and enable unstable_offset_of
This makes the compiler use the builtin `offset_of!()` macro, through the wrappers in memoffset and then in field-offset.
cc #111839
Uplift `clippy::cmp_nan` lint
This PR aims at uplifting the `clippy::cmp_nan` lint into rustc.
## `invalid_nan_comparisons`
~~(deny-by-default)~~ (warn-by-default)
The `invalid_nan_comparisons` lint checks comparison with `f32::NAN` or `f64::NAN` as one of the operand.
### Example
```rust,compile_fail
let a = 2.3f32;
if a == f32::NAN {}
```
### Explanation
NaN does not compare meaningfully to anything – not even itself – so those comparisons are always false.
-----
Mostly followed the instructions for uplifting a clippy lint described here: https://github.com/rust-lang/rust/pull/99696#pullrequestreview-1134072751
`@rustbot` label: +I-lang-nominated
r? compiler
expand: Change how `#![cfg(FALSE)]` behaves on crate root
Previously it removed all other attributes from the crate root.
Now it removes only attributes below itself (during both regular expansion and pre-configuration).
So it becomes possible to configure some global crate properties even for fully unconfigured crates.
Fixes https://github.com/rust-lang/rust/issues/104633
Part of https://github.com/rust-lang/rust/issues/110082
increase the accuracy of effective visibilities calculation
Effective visibilities are calculated lazily due to performance restrictions. Therefore
- crate should be walked at least 1 time in `compute_effective_visibilities` pass
- Impl's should always be in the effective visibilities table
to ensure that the table is filled in correctly.
r? `@petrochenkov`
Previously it removed all other attributes from the crate root.
Now it removes only attributes below itself.
So it becomes possible to configure some global crate properties even for fully unconfigured crates.
Support float-like tuple indices in offset_of!()
Supports invocations like `offset_of!((((), ()), ()), 0.0)`. This `0.0` gets tokenized as float literal, so it has to be broken up again.
The code that did the breaking up was returning a finished `Expr`, while we need a `Ident`, so this PR splits up the `parse_expr_tuple_field_access_float` function into:
* a function that breaks up the float literal (similar to `TokenKind::break_two_token_op`, but we do access the parser during this splitting operation, so we keep it as an inherent function on the parser)
* and a function that constructs an `Expr` from it
The former we can then re-use in `offset_of` parsing. The edge cases especially involving whitespaces are tricky so this adds a bunch of new tests as well.
fixes#112204
