assume MIR types are fully normalized in ascribe_user_type
This FIXME was introduced in c6a17bf8bc but it should've been restricted to `ascribe_user_type_skip_wf`.
Forward the `Display` implementation for `CrateType` to
`IntoDiagnosticArg` so that it can be used in diagnostic structs.
Signed-off-by: David Wood <david.wood@huawei.com>
Implement `IntoDiagnosticArg` for `&'a T` when `T` implements
`IntoDiagnosticArg` and `Clone`. Makes it easier to write diagnostic
structs that borrow something which implements `IntoDiagnosticArg`.
Signed-off-by: David Wood <david.wood@huawei.com>
Support for emission of notes was added in f8ebc72 but `emit_note` and
`create_note` functions weren't added to `Handler`.
Signed-off-by: David Wood <david.wood@huawei.com>
Rollup of 7 pull requests
Successful merges:
- #107125 (Add and use expect methods to hir.)
- #107172 (Reimplement NormalizeArrayLen based on SsaLocals)
- #107177 (Keep all theme-updating logic together)
- #107424 (Make Vec::clone_from and slice::clone_into share the same code)
- #107455 (use a more descriptive name)
- #107465 (`has_allow_dead_code_or_lang_attr` micro refactor)
- #107469 (Change turbofish context link to an archive link)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Change turbofish context link to an archive link
The original tweet in the chain linked to (via quote tweet), and thus the through line of links back to Anna's tweet where she named the turbofish (https://web.archive.org/web/20210911061514/https://twitter.com/whoisaldeka/status/914914008225816576) are lost as the user whoisaldeka has deleted their twitter account.
Switching to an archive link preserves this through line, allowing someone to browse back to see the point at which Anna created the turbofish, as was the original intent of including this context.
I was sharing this test with some friends as I often do, and noticed the changes (I had only seen the version from before her death previously). Looking for context myself, I realized the deleted twitter account was breaking an important link in the chain for the context of who Anna was to begin with, and the exact moment the turbofish was so named.
As an alternative to using an archive, we could link to both the tweet where Anna names the turbofish, and the tweet where she refers to herself as its guardian, as two separate links - not requiring the quote tweet to connect them.
Make Vec::clone_from and slice::clone_into share the same code
In the past, `Vec::clone_from` was implemented using `slice::clone_into`. The code from `clone_into` was later duplicated into `clone_from` in 8725e4c337, which is the commit that adds custom allocator support to Vec. Presumably this was done because the `slice::clone_into` method only works for vecs with the default allocator so it would have the wrong type to clone into `Vec<T, A>`.
Later on in 361398009b the code for the two methods diverged because the `Vec::clone_from` version gained a specialization to optimize the case when T is Copy. In order to reduce code duplication and make them both be able to take advantage of this specialization, this PR moves the specialization into the slice module and makes vec use it again.
Keep all theme-updating logic together
Prior to this PR, if the page is restored from the browser bfcache¹, we call `switchToSavedTheme`. But `switchToSavedTheme` never looks at the `use-system-theme` preference. Further, if it can't find a saved theme, it will fall back to the default of "light".
For a user with cookies disabled² whose preferred color scheme is dark, this means the theme will wobble back and forth between dark and light. The sequence that occurs is,
1. The page is loaded. During a page load, we consult `use-system-theme`: as cookies are disabled, this preference is unset. The default is true.
Because the default is true, we look at the preferred color scheme: for our example user, that's "dark". **The page theme is set to dark.** We'll attempt to store these preferences in localStorage, but fail due to cookies being disabled.
2. The user navigates through the docs. Subsequent page loads happen, and the same process in step 1 recurs. Previous pages are (potentially) put into the bfcache.
3. The user navigates backwards/forwards, causing a page in bfcache to be pulled out of cache. The `pageShow` event handler is triggered. However, this calls `switchToSavedTheme`: this doesn't consider the system theme, as noted above. Instead, it only looks for a saved theme. However, with cookies disabled, there is none. It defaults to light. **The page theme is set to light!** The user wonders why the dark theme is lost.
There are effectively two functions trying to determine and apply the correct theme: `updateSystemTheme` and `switchToSavedTheme`. Thus, we merge them into just one: `updateTheme`. This function contains all the logic for determining the correct theme, and is called in all circumstances where we need to set the theme:
* The initial page load
* If the browser preferred color scheme (i.e., light/dark mode) is changed
* If the page is restored from bfcache
* If the user updates the theme preferences (i.e., in `settings.js`)
Fixes https://github.com/rust-lang/rust/issues/94250.
¹bfcache: https://web.dev/bfcache/ The bfcache is used to sleep a page, if the user navigates away from it, and to restore it from cache if the user returns to it.
²Note that the browser preference that enables/disables cookies really controls many forms of storage. The same preference thus also affects localStorage. (This is so a normal browser user doesn't need to understand the distinction between "cookies" and "localStorage".)
The original tweet in the chain linked to, and thus the through line of links back to Anna's tweet where she named the turbofish (https://web.archive.org/web/20210911061514/https://twitter.com/whoisaldeka/status/914914008225816576) are lost as the user whoisaldeka has deleted their twitter account.
Switching to an archive link preserves this through line, allowing someone to browse back to see the point at which Anna created the turbofish, as was the original intent of including this context.
bootstrap: cleanup the list of extra check cfgs
This PR performs some cleanups on the `EXTRA_CHECK_CFGS` list in bootstrap.
- `target_os=watchos`: no longer relevant because there are now proper targets `*-apple-watchos`
- `target_arch=nvptx64`: target `nvptx64-nvidia-cuda` makes it useless
- `target_arch=le32`: target was removed (https://github.com/rust-lang/rust/pull/45041)
- `release`: was removed from rustfmt (https://github.com/rust-lang/rustfmt/pull/5375 and https://github.com/rust-lang/rustfmt/pull/5449)
- `dont_compile_me`: was removed from stdarch (https://github.com/rust-lang/stdarch/pull/1308)
Also made some external cfg exception mode clear and only activated for rustc and rustc tools (as to not have the Standard Library unintentionally depend on them).
Add option to include private items in library docs
I need to perform some one-off analysis on libcore, and I wanted to use the unstable JSON rustdoc output to easily do it. Unfortunately, there is currently no way to include unstable items in the library docs. This PR adds support for that, with the off-by-default `build.library-docs-private-items` setting.
Don't re-export private/unstable ArgumentV1 from `alloc`.
The `alloc::fmt::ArgumentV1` re-export was marked as `#[stable]` even though the original `core::fmt::ArgumentV1` is `#[unstable]` (and `#[doc(hidden)]`).
(It wasn't usable though:
```
error[E0658]: use of unstable library feature 'fmt_internals': internal to format_args!
--> src/main.rs:4:12
|
4 | let _: alloc::fmt::ArgumentV1 = todo!();
| ^^^^^^^^^^^^^^^^^^^^^^
|
= help: add `#![feature(fmt_internals)]` to the crate attributes to enable
```
)
Part of #99012
Prior to this PR, if the page is restored from the browser bfcache¹, we
call `switchToSavedTheme`. But `switchToSavedTheme` never looks at the
`use-system-theme` preference. Further, if it can't find a saved theme,
it will fall back to the default of "light".
For a user with cookies disabled² whose preferred color scheme is dark,
this means the theme will wobble back and forth between dark and light.
The sequence that occurs is,
1. The page is loaded. During a page load, we consult
`use-system-theme`: as cookies are disabled, this preference is
unset. The default is true.
Because the default is true, we look at the preferred color scheme:
for our example user, that's "dark". **The page theme is set to
dark.** We'll attempt to store these preferences in localStorage, but
fail due to cookies being disabled.
2. The user navigates through the docs. Subsequent page loads happen,
and the same process in step 1 recurs. Previous pages are
(potentially) put into the bfcache.
3. The user navigates backwards/forwards, causing a page in bfcache to
be pulled out of cache. The `pageShow` event handler is triggered.
However, this calls `switchToSavedTheme`: this doesn't consider the
system theme, as noted above. Instead, it only looks for a saved
theme. However, with cookies disabled, there is none. It defaults to
light. **The page theme is set to light!** The user wonders why the
dark theme is lost.
There are effectively two functions trying to determine and apply the
correct theme: `updateSystemTheme` and `switchToSavedTheme`. Thus, we
merge them into just one: `updateTheme`. This function contains all the
logic for determining the correct theme, and is called in all
circumstances where we need to set the theme:
* The initial page load
* If the browser preferred color scheme (i.e., light/dark mode) is
changed
* If the page is restored from bfcache
* If the user updates the theme preferences (i.e., in `settings.js`)
Fixes#94250.
¹bfcache: https://web.dev/bfcache/ The bfcache is used to sleep a page,
if the user navigates away from it, and to restore it from cache if the
user returns to it.
²Note that the browser preference that enables/disables cookies really
controls many forms of storage. The same preference thus also affects
localStorage. (This is so a normal browser user doesn't need to
understand the distinction between "cookies" and "localStorage".)
Currently, deriving on packed structs has some non-trivial limitations,
related to the fact that taking references on unaligned fields is UB.
The current approach to field accesses in derived code:
- Normal case: `&self.0`
- In a packed struct that derives `Copy`: `&{self.0}`
- In a packed struct that doesn't derive `Copy`: `&self.0`
Plus, we disallow deriving any builtin traits other than `Default` for any
packed generic type, because it's possible that there might be
misaligned fields. This is a fairly broad restriction.
Plus, we disallow deriving any builtin traits other than `Default` for most
packed types that don't derive `Copy`. (The exceptions are those where the
alignments inherently satisfy the packing, e.g. in a type with
`repr(packed(N))` where all the fields have alignments of `N` or less
anyway. Such types are pretty strange, because the `packed` attribute is
not having any effect.)
This commit introduces a new, simpler approach to field accesses:
- Normal case: `&self.0`
- In a packed struct: `&{self.0}`
In the latter case, this requires that all fields impl `Copy`, which is
a new restriction. This means that the following example compiles under
the old approach and doesn't compile under the new approach.
```
#[derive(Debug)]
struct NonCopy(u8);
#[derive(Debug)
#[repr(packed)]
struct MyType(NonCopy);
```
(Note that the old approach's support for cases like this was brittle.
Changing the `u8` to a `u16` would be enough to stop it working. So not
much capability is lost here.)
However, the other constraints from the old rules are removed. We can now
derive builtin traits for packed generic structs like this:
```
trait Trait { type A; }
#[derive(Hash)]
#[repr(packed)]
pub struct Foo<T: Trait>(T, T::A);
```
To allow this, we add a `T: Copy` bound in the derived impl and a `T::A:
Copy` bound in where clauses. So `T` and `T::A` must impl `Copy`.
We can now also derive builtin traits for packed structs that don't derive
`Copy`, so long as the fields impl `Copy`:
```
#[derive(Hash)]
#[repr(packed)]
pub struct Foo(u32);
```
This includes types that hand-impl `Copy` rather than deriving it, such as the
following, that show up in winapi-0.2:
```
#[derive(Clone)]
#[repr(packed)]
struct MyType(i32);
impl Copy for MyType {}
```
The new approach is simpler to understand and implement, and it avoids
the need for the `unsafe_derive_on_repr_packed` check.
One exception is required for backwards-compatibility: we allow `[u8]`
fields for now. There is a new lint for this,
`byte_slice_in_packed_struct_with_derive`.
Port pgo.sh to Python
This PR ports the `pgo.sh` multi stage build file from bash to Python, to make it easier to add new functionality and gather statistics. Main changes:
1) `pgo.sh` rewritten from Bash to Python. Jump from ~200 Bash LOC to ~650 Python LOC. Bash is, unsurprisingly, more concise for running scripts and binaries.
2) Better logging. Each separate stage is now clearly separated in logs, and the logs can be quickly grepped to find out which stage has completed or failed, and how long it took.
3) Better statistics. At the end of the run, there is now a table that shows the duration of the individual stages, along with a percentual ratio of the total workflow run:
```
2023-01-15T18:13:49.9896916Z stage-build INFO: Timer results
2023-01-15T18:13:49.9902185Z ---------------------------------------------------------
2023-01-15T18:13:49.9902605Z Build rustc (LLVM PGO): 1815.67s (21.47%)
2023-01-15T18:13:49.9902949Z Gather profiles (LLVM PGO): 418.73s ( 4.95%)
2023-01-15T18:13:49.9903269Z Build rustc (rustc PGO): 584.46s ( 6.91%)
2023-01-15T18:13:49.9903835Z Gather profiles (rustc PGO): 806.32s ( 9.53%)
2023-01-15T18:13:49.9904154Z Build rustc (LLVM BOLT): 1662.92s (19.66%)
2023-01-15T18:13:49.9904464Z Gather profiles (LLVM BOLT): 715.18s ( 8.46%)
2023-01-15T18:13:49.9914463Z Final build: 2454.00s (29.02%)
2023-01-15T18:13:49.9914798Z Total duration: 8457.27s
2023-01-15T18:13:49.9915305Z ---------------------------------------------------------
```
A sample run can be seen [here](https://github.com/rust-lang/rust/actions/runs/3923980164/jobs/6707932029).
I tried to keep the code compatible with Python 3.6 and don't use dependencies, which required me to reimplement some small pieces of functionality (like formatting bytes). I suppose that it shouldn't be so hard to upgrade to a newer Python or install dependencies in the CI container, but I'd like to avoid it if it won't be needed.
The code is in a single file `stage-build.py`, so it's a bit cluttered. I can also separate it into multiple files, although having it in a single file has some benefits. The code could definitely be nicer, but I'm a bit wary of introducing a lot of abstraction and similar stuff, as long as the code is stuffed into a single file.
Currently, the Python pipeline should faithfully mirror the bash pipeline one by one. After this PR, I'd like to try to optimize it, e.g. by caching the LLVM builds on S3.
r? `@Mark-Simulacrum`
