Auto merge of #83870 - jackh726:binder-refactor-fix, r=nikomatsakis
Don't concatenate binders across types
Partially addresses #83737
There's actually two issues that I uncovered in #83737. The first is that we are concatenating bound vars across types, i.e. in
```
F: Fn(&()) -> &mut (dyn Future<Output = ()> + Unpin)
```
the bound vars on `Future` get set as `for<anon>` since those are the binders on `Fn(&()`. This is obviously wrong, since we should only concatenate directly nested trait refs. This is solved here by introducing a new `TraitRefBoundary` scope, that we put around the "syntactical" trait refs and basically don't allow concatenation across.
Now, this alone *shouldn't* be a super terrible problem. At least not until you consider the other issue, which is a much more elusive and harder to design a "perfect" fix. A repro can be seen in:
```
use core::future::Future;
async fn handle<F>(slf: &F)
where
F: Fn(&()) -> &mut (dyn for<'a> Future<Output = ()> + Unpin),
{
(slf)(&()).await;
}
```
Notice the `for<'a>` around `Future`. Here, `'a` is unused, so the `for<'a>` Binder gets changed to a `for<>` Binder in the generator witness, but the "local decl" still has it. This has heavy intersections with region anonymization and erasing. Luckily, it's not *super* common to find this unique set of circumstances. It only became apparently because of the first issue mentioned here. However, this *is* still a problem, so I'm leaving #83737 open.
Auto merge of #83941 - wesleywiser:win_dbginfo_closures, r=nagisa
Improve debuginfo for closures and async functions on Windows MSVC
The issue was that the resulting debuginfo was too complex for LLVM to
translate into CodeView records correctly. As a result, it simply
ignored the debuginfo which meant Windows debuggers could not display
any closed over variables when stepping inside a closure or async fn.
This fixes that by creating additional allocas on the stack so that
the resulting debuginfo is simple (just `*my_variable.dbg.spill`) and
LLVM can generate the correct CV records.
I also updated some of our existing tests to run in CDB to cover this case.
Rollup merge of #83992 - GuillaumeGomez:merge-idents, r=notriddle
Merge idents when generating source content
The idea here is to not have a span for each part of a path. Currently, for `a::b::c` we generate `<span>a</span>::<span>b</span>::<span>c</span>`, with this change, we will generate `<span>a::b::c</span>`.
A nice "side-effect" is that it reduces the size of the output HTML too. :)
Rollup merge of #81938 - lukaslueg:stab_peek_mut, r=Amanieu
Stabilize `peekable_peek_mut`
Resolves #78302. Also adds some documentation on `std::iter::Iterator::peekable()` regarding the new method.
The feature was added in #77491 in Nov' 20, which is recently, but the feature seems reasonably small. Never did a stabilization-pr, excuse my ignorance if there is a protocol I'm not aware of.
Rollup merge of #80733 - steffahn:prettify_pin_links, r=jyn514
Improve links in inline code in `core::pin`.
## Context
So I recently opened #80720. That PR uses HTML-based `<code>foo</code>` syntax in place of `` `foo` `` for some inline code. It looks like usage of `<code>` tags in doc comments is without precedent in the standard library, but the HTML-based syntax has an important advantage:
You can write something like
```
<code>[Box]<[Option]\<T>></code>
```
which becomes: <code>[Box]<[Option]\<T>></code>, whereas with ordinary backtick syntax, you cannot create links for a substring of an inline code block.
## Problem
I recalled (from my own experience) that a way to partially work around this limitation is to do something like
```
[`Box`]`<`[`Option`]`<T>>`
```
which looks like this: [`Box`]`<`[`Option`]`<T>>` _(admitted, it looks even worse on GitHub than in `rustdoc`’s CSS)_.
So I searched the standard library and found that e.g. the [std::pin](https://doc.rust-lang.org/std/pin/index.html) module documentation uses this hack/workaround quite a bit, with types like <code>[Pin]<[Box]\<T>></code> or <code>[Pin]<[&mut] T>></code>. Although the way they look like in this sentence is what I would like them to look like, not what they currently look.
### Status Quo
Here’s a screenshot of what it currently looks like:
With a few HTML-style code blocks, we can fix all the spacing issues in the above screenshot that are due usage of this hack/workaround of putting multiple code blocks right next to each other being used.
There’s still a problem of inconsistency. Especially in a sentence such as
> A [`Pin<P>`][Pin] where `P: Deref` should be considered as a "`P`-style pointer" to _[...]_
looks weird with the variable `P` having different colors (and `Deref` has a different color from before where it was a link, too). Or compare the difference of <code>[Pin]<[Box]\<T>></code> vs [`Box<T>`][Box] where one time the variable is part of the link and the other time it isn’t.
_Note: Color differences show even **more strongly** when the ayu theme is used, while they are a bit less prominent in the light theme than they are in the dark theme, which is the one used for these screenshots._
This is why I’ve added the next commit
### after ceaeb249a3813a78bd81fa3890e27e8843a58262
pulling all the type parameters out of their links, and also the last commit with clearly visible changes
### after 87ac118ba3d0c8268e043fadbd63b51e06904795
where more links are added, removing e.g. the inconsistency with `Deref`’s color in e.g. `P: Deref` that I already mentioned above.
## Discussion
I am aware that this PR may very well be overkill. If for now only the first commit (plus the fix for the `Drop` link in e65385fbfa72995b27ec64aa54f330cf503dfc03, the link titles 684edf7a70d2e90466ae74e7a321670259bf3fd9 as far as they apply, and a few of the line-break changes) are wanted, I can reduce this PR to just those changes. I personally find the rendered result with all these changes very nice though. On the other hand, all these `<code>` tags are not very nice in the source code, I’ll admit.
Perhaps alternative solutions could be preferred, such as `rustdoc` support for merging subsequent inline code blocks so that all the cases that currently use workarounds rendered as [`Box`]`<`[`Option`]`<T>>` automatically become <code>[Box]<[Option]\<T>></code> without any need for further changes. Even in this case, having a properly formatted, better looking example in the standard library docs could help motivate such a change to `rustdoc` by prodiving an example of the expected results and also the already existing alternative (i.e. using `<code>`). On the other hand, `` [`Box`]`<`[`Option`]`<T>>` `` isn’t particularly nice-looking source code either. I’m not even sure if I wouldn’t actually find the version `<code>[Box]<[Option]\<T>></code>` cleaner to read.
Fix closed over variables not available in debuginfo for Windows MSVC
The issue was that the resulting debuginfo was too complex for LLVM to
translate into CodeView records correctly. As a result, it simply
ignored the debuginfo which meant Windows debuggers could not display
any closed over variables when stepping inside a closure.
This fixes that by spilling additional variables to the stack so that
the resulting debuginfo is simple (just `*my_variable.dbg.spill`) and
LLVM can generate the correct CV records.
Auto merge of #83763 - alexcrichton:wasm-multivalue-abi, r=nagisa
rustc: Add a new `wasm` ABI
This commit implements the idea of a new ABI for the WebAssembly target,
one called `"wasm"`. This ABI is entirely of my own invention
and has no current precedent, but I think that the addition of this ABI
might help solve a number of issues with the WebAssembly targets.
When `wasm32-unknown-unknown` was first added to Rust I naively
"implemented an abi" for the target. I then went to write `wasm-bindgen`
which accidentally relied on details of this ABI. Turns out the ABI
definition didn't match C, which is causing issues for C/Rust interop.
Currently the compiler has a "wasm32 bindgen compat" ABI which is the
original implementation I added, and it's purely there for, well,
`wasm-bindgen`.
Another issue with the WebAssembly target is that it's not clear to me
when and if the default C ABI will change to account for WebAssembly's
multi-value feature (a feature that allows functions to return multiple
values). Even if this does happen, though, it seems like the C ABI will
be guided based on the performance of WebAssembly code and will likely
not match even what the current wasm-bindgen-compat ABI is today. This
leaves a hole in Rust's expressivity in binding WebAssembly where given
a particular import type, Rust may not be able to import that signature
with an updated C ABI for multi-value.
To fix these issues I had the idea of a new ABI for WebAssembly, one
called `wasm`. The definition of this ABI is "what you write
maps straight to wasm". The goal here is that whatever you write down in
the parameter list or in the return values goes straight into the
function's signature in the WebAssembly file. This special ABI is for
intentionally matching the ABI of an imported function from the
environment or exporting a function with the right signature.
With the addition of a new ABI, this enables rustc to:
* Eventually remove the "wasm-bindgen compat hack". Once this multivalue
ABI is stable wasm-bindgen can switch to using it everywhere.
Afterwards the wasm32-unknown-unknown target can have its default ABI
updated to match C.
* Expose the ability to precisely match an ABI signature for a
WebAssembly function, regardless of what the C ABI that clang chooses
turns out to be.
* Continue to evolve the definition of the default C ABI to match what
clang does on all targets, since the purpose of that ABI will be
explicitly matching C rather than generating particular function
imports/exports.
Naturally this is implemented as an unstable feature initially, but it
would be nice for this to get stabilized (if it works) in the near-ish
future to remove the wasm32-unknown-unknown incompatibility with the C
ABI. Doing this, however, requires the feature to be on stable because
wasm-bindgen works with stable Rust.
Alex Crichton [Thu, 1 Apr 2021 23:08:29 +0000 (16:08 -0700)]
rustc: Add a new `wasm` ABI
This commit implements the idea of a new ABI for the WebAssembly target,
one called `"wasm"`. This ABI is entirely of my own invention
and has no current precedent, but I think that the addition of this ABI
might help solve a number of issues with the WebAssembly targets.
When `wasm32-unknown-unknown` was first added to Rust I naively
"implemented an abi" for the target. I then went to write `wasm-bindgen`
which accidentally relied on details of this ABI. Turns out the ABI
definition didn't match C, which is causing issues for C/Rust interop.
Currently the compiler has a "wasm32 bindgen compat" ABI which is the
original implementation I added, and it's purely there for, well,
`wasm-bindgen`.
Another issue with the WebAssembly target is that it's not clear to me
when and if the default C ABI will change to account for WebAssembly's
multi-value feature (a feature that allows functions to return multiple
values). Even if this does happen, though, it seems like the C ABI will
be guided based on the performance of WebAssembly code and will likely
not match even what the current wasm-bindgen-compat ABI is today. This
leaves a hole in Rust's expressivity in binding WebAssembly where given
a particular import type, Rust may not be able to import that signature
with an updated C ABI for multi-value.
To fix these issues I had the idea of a new ABI for WebAssembly, one
called `wasm`. The definition of this ABI is "what you write
maps straight to wasm". The goal here is that whatever you write down in
the parameter list or in the return values goes straight into the
function's signature in the WebAssembly file. This special ABI is for
intentionally matching the ABI of an imported function from the
environment or exporting a function with the right signature.
With the addition of a new ABI, this enables rustc to:
* Eventually remove the "wasm-bindgen compat hack". Once this
ABI is stable wasm-bindgen can switch to using it everywhere.
Afterwards the wasm32-unknown-unknown target can have its default ABI
updated to match C.
* Expose the ability to precisely match an ABI signature for a
WebAssembly function, regardless of what the C ABI that clang chooses
turns out to be.
* Continue to evolve the definition of the default C ABI to match what
clang does on all targets, since the purpose of that ABI will be
explicitly matching C rather than generating particular function
imports/exports.
Naturally this is implemented as an unstable feature initially, but it
would be nice for this to get stabilized (if it works) in the near-ish
future to remove the wasm32-unknown-unknown incompatibility with the C
ABI. Doing this, however, requires the feature to be on stable because
wasm-bindgen works with stable Rust.
Auto merge of #83981 - nagisa:nagisa/revert-cfg-wasm, r=Mark-Simulacrum
Remove the insta-stable `cfg(wasm)`
The addition of `cfg(wasm)` was an oversight on my end that turns out to have a number
of downsides:
* It was introduced as an insta-stable addition, forgoing the usual
staging mechanism we use for potentially far-reaching changes;
* It is a breaking change for people who are using `--cfg wasm` either
directly or via cargo for other purposes;
* It is not entirely clear if a bare `wasm` cfg is a right option or
whether `wasm` family of targets are special enough to warrant
special-casing these targets specifically.
As for the last point, there appears to be a fair amount of support for
reducing the boilerplate in specifying architectures from the same
family, while ignoring their pointer width. The suggested way forward
would be to propose such a change as a separate RFC as it is potentially
a quite contentious addition.
Auto merge of #83986 - Dylan-DPC:rollup-51vygcj, r=Dylan-DPC
Rollup of 5 pull requests
Successful merges:
- #82497 (Fix handling of `--output-format json` flag)
- #83689 (Add more info for common trait resolution and async/await errors)
- #83952 (Account for `ExprKind::Block` when suggesting .into() and deref)
- #83965 (Add Debug implementation for hir::intravisit::FnKind)
- #83974 (Fix outdated crate names in `rustc_interface::callbacks`)
Rollup merge of #82497 - jyn514:json, r=CraftSpider
Fix handling of `--output-format json` flag
- Don't treat it as deprecated on stable and beta channels. Before, it
would give confusing and incorrect output:
```
warning: the 'output-format' flag is considered deprecated
|
= warning: see issue #44136 <https://github.com/rust-lang/rust/issues/44136> for more information
error: json output format isn't supported for doc generation
```
Both of those are wrong: output-format isn't deprecated, and json
output is supported.
- Require -Z unstable-options for `--output-format json`
Previously, it was allowed by default on nightly, which made it hard
to realize the flag wouldn't be accepted on beta or stable.
To get the test working I had to remove `-Z unstable-options`, which x.py passed to compiletest unconditionally. It was first added in https://github.com/rust-lang/rust/commit/8c2ec689c159e7f021d5913efb991aff875be967 so `-Z miri` would be allowed. -Z miri is no longer passed unconditionally, so hopefully removing it won't break anything.
r? ```@aDotInTheVoid``` cc ```@HeroicKatora``` ```@CraftSpider```
Thanks to ```@memoryruins``` for pointing it out on Discord!
cc ```@Mark-Simulacrum``` for the change to compiletest.
Auto merge of #82451 - jyn514:defaults, r=Mark-Simulacrum
Cleanup option parsing and config.toml.example
- Add an assertion that `link-shared = true` when `thin-lto = true`.
Previously, link-shared would be silently overwritten.
- Get rid of `Option<bool>` in bootstrap/config.rs. Set defaults
immediately instead of delaying until later in bootstrap. This makes
it easier to find what the default value is.
- Remove redundant `config.x = false` when the default was already false
- Set defaults for `bindir` in `default_opts()` instead of `parse()`
- Update `download-ci-llvm = if-supported` option to match bootstrap.py
- Remove redundant check for link_shared. Previously, it was checked twice.
- Update various options in config.toml.example to their defaults.
Previously, some options showed an example value instead of the
default value.
- Fix incorrect defaults in config.toml.example
+ `use-libcxx` defaults to false
+ Add missing `check-stage = 0`
+ Update several defaults to be conditional (e.g. `if incremental { 10 } else { 100 }`)
- Remove redundant defaults in prose
- Use the same comment for the default and target-dependent `musl-root`
- Fix typos
- Link to `cc_detect` for `cc` and `cxx`, since the logic is ... complicated.
- Update more defaults to better reflect how they actually get set
- Remove ignored `gpg-password-file` option
This stopped being used in 7704d35,
but was never removed from config.toml.
- Remove unused flags from `config.toml`
+ Disallow `infodir` and `localstatedir` in `config.toml`
+ Allow the flags in `./configure`, but give a warning that they will be
ignored.
+ Fix incorrect comment that `datadir` will be ignored.
Example output:
```
$ ./configure --set install.infodir=xxx
configure: processing command line
configure:
configure: install.infodir := xxx
configure: build.configure-args := ['--set', 'install.infodir=xxx']
warning: infodir will be ignored
configure:
configure: writing `config.toml` in current directory
configure:
configure: run `python /home/joshua/rustc3/x.py --help`
configure:
```
- Update CHANGELOG
cc https://rust-lang.zulipchat.com/#narrow/stream/131828-t-compiler/topic/bootstrap.20defaults
The addition of `cfg(wasm)` was an oversight on my end that has a number
of downsides:
* It was introduced as an insta-stable addition, forgoing the usual
staging mechanism we use for potentially far-reaching changes;
* It is a breaking change for people who are using `--cfg wasm` either
directly or via cargo for other purposes;
* It is not entirely clear if a bare `wasm` cfg is a right option or
whether `wasm` family of targets are special enough to warrant
special-casing these targets specifically.
As for the last point, there appears to be a fair amount of support for
reducing the boilerplate in specifying architectures from the same
family, while ignoring their pointer width. The suggested way forward
would be to propose such a change as a separate RFC as it is potentially
a quite contentious addition.
Joshua Nelson [Tue, 23 Feb 2021 18:01:39 +0000 (13:01 -0500)]
Cleanup option parsing and config.toml.example
- Add an assertion that `link-shared = true` when `thin-lto = true`.
Previously, link-shared would be silently overwritten.
- Get rid of `Option<bool>` in bootstrap/config.rs. Set defaults
immediately instead of delaying until later in bootstrap. This makes
it easier to find what the default value is.
- Remove redundant `config.x = false` when the default was already false
- Set defaults for `bindir` in `default_opts()` instead of `parse()`
- Update `download-ci-llvm = if-supported` option to match bootstrap.py
- Remove redundant check for link_shared. Previously, it was checked twice.
- Update various options in config.toml.example to their defaults.
Previously, some options showed an example value instead of the
default value.
- Fix incorrect defaults in config.toml.example
+ `use-libcxx` defaults to false
+ Add missing `check-stage = 0`
+ Update several defaults to be conditional (e.g. `if incremental { 10 } else { 100 }`)
- Remove redundant defaults in prose
- Use the same comment for the default and target-dependent `musl-root`
- Fix typos
- Link to `cc_detect` for `cc` and `cxx`, since the logic is ... complicated.
- Update more defaults to better reflect how they actually get set
- Remove ignored `gpg-password-file` option
- Remove unused flags from `config.toml`
+ Disallow `infodir` and `localstatedir` in `config.toml`
+ Allow the flags in `./configure`, but give a warning that they will be
ignored.
+ Fix incorrect comment that `datadir` will be ignored.
Example output:
```
$ ./configure --set install.infodir=xxx
configure: processing command line
configure:
configure: install.infodir := xxx
configure: build.configure-args := ['--set', 'install.infodir=xxx']
warning: infodir will be ignored
configure:
configure: writing `config.toml` in current directory
configure:
configure: run `python /home/joshua/rustc3/x.py --help`
configure:
```
- Update CHANGELOG
- Add "as an example" where appropriate
- Link to an issue instead of to ephemeral chats
Auto merge of #83964 - Dylan-DPC:rollup-9kinaiv, r=Dylan-DPC
Rollup of 8 pull requests
Successful merges:
- #83476 (Add strong_count mutation methods to Rc)
- #83634 (Do not emit the advanced diagnostics on macros)
- #83816 (Trigger `unused_doc_comments` on macros at once)
- #83916 (Use AnonConst for asm! constants)
- #83935 (forbid `impl Trait` in generic param defaults)
- #83936 (Disable using non-ascii identifiers in extern blocks.)
- #83945 (Add suggestion to reborrow mutable references when they're moved in a for loop)
- #83954 (Do not ICE when closure is involved in Trait Alias Impl Trait)
Rollup merge of #83935 - SNCPlay42:param-default-impl-trait, r=varkor
forbid `impl Trait` in generic param defaults
Fixes #83929
Forbid using `impl Trait` in the default types of generic parameters, e.g. `struct Foo<T = impl Trait>`. I assume this was never supposed to be allowed - it seems no UI test used it.
Note that using `impl Trait` in this position did not hit a feature gate error; however, this *shouldn't* be a breaking change as any attempt to use it should have hit the ICE in #83929 and/or failed to provide a defining use of the `impl Trait`.
Rollup merge of #83916 - Amanieu:asm_anonconst, r=petrochenkov
Use AnonConst for asm! constants
This replaces the old system which used explicit promotion. See #83169 for more background.
The syntax for `const` operands is still the same as before: `const <expr>`.
Fixes #83169
Because the implementation is heavily based on inline consts, we suffer from the same issues:
- We lose the ability to use expressions derived from generics. See the deleted tests in `src/test/ui/asm/const.rs`.
- We are hitting the same ICEs as inline consts, for example #78174. It is unlikely that we will be able to stabilize this before inline consts are stabilized.
Rollup merge of #83916 - Amanieu:asm_anonconst, r=petrochenkov
Use AnonConst for asm! constants
This replaces the old system which used explicit promotion. See #83169 for more background.
The syntax for `const` operands is still the same as before: `const <expr>`.
Fixes #83169
Because the implementation is heavily based on inline consts, we suffer from the same issues:
- We lose the ability to use expressions derived from generics. See the deleted tests in `src/test/ui/asm/const.rs`.
- We are hitting the same ICEs as inline consts, for example #78174. It is unlikely that we will be able to stabilize this before inline consts are stabilized.
Rollup merge of #83476 - mystor:rc_mutate_strong_count, r=m-ou-se
Add strong_count mutation methods to Rc
The corresponding methods were stabilized on `Arc` in #79285 (tracking: #71983). This patch implements and stabilizes identical methods on the `Rc` types as well.
Auto merge of #83833 - jyn514:no-resolver, r=GuillaumeGomez
rustdoc: Store intra-doc links in Cache instead of on items directly
Items are first built after rustdoc creates the TyCtxt. To allow
resolving the links before the TyCtxt is built, the links can't be
stored on `clean::Item` directly.
Helps with https://github.com/rust-lang/rust/issues/83761. Opening this early because I think it might decrease memory usage.
Joshua Nelson [Wed, 24 Feb 2021 21:16:49 +0000 (16:16 -0500)]
Fix handling of `--output-format json` flag
- Don't treat it as deprecated on stable and beta channels. Before, it
would give confusing and incorrect output:
```
warning: the 'output-format' flag is considered deprecated
|
= warning: see issue #44136 <https://github.com/rust-lang/rust/issues/44136> for more information
error: json output format isn't supported for doc generation
```
Both of those are wrong: output-format isn't deprecated, and json
output is supported.
- Require -Z unstable-options for `--output-format json`
Previously, it was allowed by default on nightly, which made it hard
to realize the flag wouldn't be accepted on beta or stable.
Note that this still allows `--output-format html`, which has been
stable since 1.0.
- Remove unnecessary double-checking of the feature gate when parsing
the output format
- Add custom run-make test since compiletest passes -Zunstable-options
by default
Joshua Nelson [Sun, 4 Apr 2021 02:15:24 +0000 (22:15 -0400)]
Store links in Cache instead of on items directly
Items are first built after rustdoc creates the TyCtxt. To allow
resolving the links before the TyCtxt is built, the links can't be
stored on `clean::Item` directly.
Auto merge of #83934 - Dylan-DPC:rollup-nw5dadn, r=Dylan-DPC
Rollup of 7 pull requests
Successful merges:
- #82963 (Move `SharedContext` to `context.rs`)
- #83829 (rustc_target: Rely on defaults more in target specs)
- #83895 (Add listing of lints (eg via `-W help`) to rustdoc)
- #83902 (Update LLVM to support more wasm simd ops)
- #83903 (Fix typo in TokenStream documentation)
- #83910 (Update cargo)
- #83920 (Fix HashMap/HashSet LLDB pretty-printer after hashbrown 0.11.0)
Rollup merge of #83920 - ortem:fix-hashmap-lldb-pretty-printer-1.52, r=pnkfelix
Fix HashMap/HashSet LLDB pretty-printer after hashbrown 0.11.0
The pretty-printer was broken in https://github.com/rust-lang/rust/pull/77566 after updating hashbrown to 0.11.0.
Note that the corresponding GDB pretty-printer was updated properly.
Auto merge of #6931 - Jarcho:needless_borrow, r=phansch,flip1995
Fix all occurences `needless_borrow` internally
The bug that got 'needless_borrow' moved into the nursery was fixed two years ago in d4370f8b.
This did trigger over a thousand times internally, so that's all the other changes. I vetted most of them, but there's a lot The only interesting change is to the lint list. `declare_tool_lint` already makes a reference, so there's no need to take a reference to the lints.
projects / rust.git / log