Mark Rousskov [Wed, 9 Feb 2022 22:05:44 +0000 (17:05 -0500)]
Remove support for JSON deserialization to Rust
This is no longer used by the compiler itself, and removing this support opens
the door to massively simplifying the Decodable/Decoder API by dropping the
self-describing deserialization support (necessary for JSON).
Frank Steffahn [Thu, 3 Feb 2022 21:16:06 +0000 (22:16 +0100)]
Improve `unused_unsafe` lint
Main motivation: Fixes some issues with the current behavior. This PR is
more-or-less completely re-implementing the unused_unsafe lint; it’s also only
done in the MIR-version of the lint, the set of tests for the `-Zthir-unsafeck`
version no longer succeeds (and is thus disabled, see `lint-unused-unsafe.rs`).
doesn’t create any warnings. This situation is not unrealistic to come by, the
inner `unsafe` block could e.g. come from a macro. Actually, this PR even
includes removal of one unused `unsafe` in the standard library that was missed
in a similar situation. (The inner `unsafe` coming from an external macro hides
the warning, too.)
The reason behind this problem is how the check currently works:
* While generating MIR, it already skips nested unsafe blocks (i.e. unsafe
nested in other unsafe) so that the inner one is always the one considered
unused
* To differentiate the cases of no unsafe operations inside the `unsafe` vs.
a surrounding `unsafe` block, there’s some ad-hoc magic walking up the HIR to
look for surrounding used `unsafe` blocks.
There’s a lot of problems with this approach besides the one presented above.
E.g. the MIR-building uses checks for `unsafe_op_in_unsafe_fn` lint to decide
early whether or not `unsafe` blocks in an `unsafe fn` are redundant and ought
to be removed.
```rs
unsafe fn granular_disallow_op_in_unsafe_fn() {
unsafe {
#[deny(unsafe_op_in_unsafe_fn)]
{
unsf();
}
}
}
```
```
error: call to unsafe function is unsafe and requires unsafe block (error E0133)
--> src/main.rs:13:13
|
13 | unsf();
| ^^^^^^ call to unsafe function
|
note: the lint level is defined here
--> src/main.rs:11:16
|
11 | #[deny(unsafe_op_in_unsafe_fn)]
| ^^^^^^^^^^^^^^^^^^^^^^
= note: consult the function's documentation for information on how to avoid undefined behavior
warning: unnecessary `unsafe` block
--> src/main.rs:10:5
|
9 | unsafe fn granular_disallow_op_in_unsafe_fn() {
| --------------------------------------------- because it's nested under this `unsafe` fn
10 | unsafe {
| ^^^^^^ unnecessary `unsafe` block
|
= note: `#[warn(unused_unsafe)]` on by default
```
Here, the intermediate `unsafe` was ignored, even though it contains a unsafe
operation that is not allowed to happen in an `unsafe fn` without an additional `unsafe` block.
Also closures were problematic and the workaround/algorithms used on current
nightly didn’t work properly. (I skipped trying to fully understand what it was
supposed to do, because this PR uses a completely different approach.)
```rs
fn nested() {
unsafe {
unsafe { unsf() }
}
}
```
```
warning: unnecessary `unsafe` block
--> src/main.rs:10:9
|
9 | unsafe {
| ------ because it's nested under this `unsafe` block
10 | unsafe { unsf() }
| ^^^^^^ unnecessary `unsafe` block
|
= note: `#[warn(unused_unsafe)]` on by default
```
vs
```rs
fn nested() {
let _ = || unsafe {
let _ = || unsafe { unsf() };
};
}
```
```
warning: unnecessary `unsafe` block
--> src/main.rs:9:16
|
9 | let _ = || unsafe {
| ^^^^^^ unnecessary `unsafe` block
|
= note: `#[warn(unused_unsafe)]` on by default
I also dislike the fact that it always suggests keeping the outermost `unsafe`.
E.g. for
```rs
fn granularity() {
unsafe {
unsafe { unsf() }
unsafe { unsf() }
unsafe { unsf() }
}
}
```
I prefer if `rustc` suggests removing the more-course outer-level `unsafe`
instead of the fine-grained inner `unsafe` blocks, which it currently does on nightly:
```
warning: unnecessary `unsafe` block
--> src/main.rs:10:9
|
9 | unsafe {
| ------ because it's nested under this `unsafe` block
10 | unsafe { unsf() }
| ^^^^^^ unnecessary `unsafe` block
|
= note: `#[warn(unused_unsafe)]` on by default
Needless to say, this PR addresses all these points. For context, as far as my
understanding goes, the main advantage of skipping inner unsafe blocks was that
a test case like
```rs
fn top_level_used() {
unsafe {
unsf();
unsafe { unsf() }
unsafe { unsf() }
unsafe { unsf() }
}
}
```
should generate some warning because there’s redundant nested `unsafe`, however
every single `unsafe` block _does_ contain some statement that uses it. Of course
this PR doesn’t aim change the warnings on this kind of code example, because
the current behavior, warning on all the inner `unsafe` blocks, makes sense in this case.
As mentioned, during MIR building all the unsafe blocks *are* kept now, and usage
is attributed to them. The way to still generate a warning like
```
warning: unnecessary `unsafe` block
--> src/main.rs:11:9
|
9 | unsafe {
| ------ because it's nested under this `unsafe` block
10 | unsf();
11 | unsafe { unsf() }
| ^^^^^^ unnecessary `unsafe` block
|
= note: `#[warn(unused_unsafe)]` on by default
in this case is by emitting a `unused_unsafe` warning for all of the `unsafe`
blocks that are _within a **used** unsafe block_.
The previous code had a little HIR traversal already anyways to collect a set of
all the unsafe blocks (in order to afterwards determine which ones are unused
afterwards). This PR uses such a traversal to do additional things including logic
like _always_ warn for an `unsafe` block that’s inside of another **used**
unsafe block. The traversal is expanded to include nested closures in the same go,
this simplifies a lot of things.
The whole logic around `unsafe_op_in_unsafe_fn` is a little complicated, there’s
some test cases of corner-cases in this PR. (The implementation involves
differentiating between whether a used unsafe block was used exclusively by
operations where `allow(unsafe_op_in_unsafe_fn)` was active.) The main goal was
to make sure that code should compile successfully if all the `unused_unsafe`-warnings
are addressed _simultaneously_ (by removing the respective `unsafe` blocks)
no matter how complicated the patterns of `unsafe_op_in_unsafe_fn` being
disallowed and allowed throughout the function are.
One noteworthy design decision I took here: An `unsafe` block
with `allow(unused_unsafe)` **is considered used** for the purposes of
linting about redundant contained unsafe blocks. So while
```rs
bors [Sun, 20 Feb 2022 05:24:52 +0000 (05:24 +0000)]
Auto merge of #93387 - JakobDegen:improve_partialeq, r=tmiasko
Extend uninhabited enum variant branch elimination to also affect fallthrough
The `uninhabited_enum_branching` mir opt eliminates branches on variants where the data is uninhabited. This change extends this pass to also ensure that the `otherwise` case points to a trivially unreachable bb if all inhabited variants are present in the non-otherwise branches.
I believe it was `@scottmcm` who said that LLVM eliminates some of this information in its SimplifyCFG pass. This is unfortunate, but this change should still be at least a small improvement in principle (I don't think it will show up on any benchmarks)
Matthias Krüger [Sat, 19 Feb 2022 23:37:34 +0000 (00:37 +0100)]
Rollup merge of #94146 - est31:let_else, r=cjgillot
Adopt let else in more places
Continuation of #89933, #91018, #91481, #93046, #93590, #94011.
I have extended my clippy lint to also recognize tuple passing and match statements. The diff caused by fixing it is way above 1 thousand lines. Thus, I split it up into multiple pull requests to make reviewing easier. This is the biggest of these PRs and handles the changes outside of rustdoc, rustc_typeck, rustc_const_eval, rustc_trait_selection, which were handled in PRs #94139, #94142, #94143, #94144.
Matthias Krüger [Sat, 19 Feb 2022 23:37:33 +0000 (00:37 +0100)]
Rollup merge of #94142 - est31:let_else_typeck, r=oli-obk
rustc_typeck: adopt let else in more places
Continuation of https://github.com/rust-lang/rust/pull/89933, https://github.com/rust-lang/rust/pull/91018, https://github.com/rust-lang/rust/pull/91481, https://github.com/rust-lang/rust/pull/93046, https://github.com/rust-lang/rust/pull/93590, https://github.com/rust-lang/rust/pull/94011.
I have extended my clippy lint to also recognize tuple passing and match statements. The diff caused by fixing it is way above 1 thousand lines. Thus, I split it up into multiple pull requests to make reviewing easier. This PR handles rustc_typeck.
Matthias Krüger [Sat, 19 Feb 2022 23:37:30 +0000 (00:37 +0100)]
Rollup merge of #94112 - digama0:patch-3, r=scottmcm
Optimize char_try_from_u32
The optimization was proposed by ```````@falk-hueffner``````` in https://rust-lang.zulipchat.com/#narrow/stream/219381-t-libs/topic/Micro-optimizing.20char.3A.3Afrom_u32/near/272146171, and I simplified it a bit and added an explanation of why the optimization is correct. The generated code is 2 instructions shorter and uses 2 registers instead of 4 on x86.
Matthias Krüger [Sat, 19 Feb 2022 23:37:28 +0000 (00:37 +0100)]
Rollup merge of #94093 - tmiasko:pp-no-variants, r=oli-obk
Fix pretty printing of enums without variants
92d20c4aaddea9507f8ad37fe37c551219153bbf removed no-variants special case from `try_destructure_const` with expectation that this case would be handled gracefully when `read_discriminant` returns an error.
Alas in that case `read_discriminant` succeeds while returning a non-existing variant, so the special case is still necessary.
Matthias Krüger [Sat, 19 Feb 2022 23:37:26 +0000 (00:37 +0100)]
Rollup merge of #94023 - krasimirgg:head-llvm-use-llvm-nm, r=Mark-Simulacrum
adapt static-nobundle test to use llvm-nm
No functional changes intended.
This updates the test case to use llvm-nm instead of the system nm.
This fixes an instance over at the experimental build of rustc with HEAD LLVM:
https://buildkite.com/llvm-project/rust-llvm-integrate-prototype/builds/8380#ef6f41b5-8595-49a6-be37-0eff80e0ccb5
It is related to https://github.com/rust-lang/rust/pull/94001.
The issue is that this test uses the system nm, which may not be recent
enough to understand the update to uwtable. This replaces the test to
use the llvm-nm that should be recent enough (consistent with the LLVM
sources we use to build rustc).
Matthias Krüger [Sat, 19 Feb 2022 23:37:25 +0000 (00:37 +0100)]
Rollup merge of #94019 - hermitcore:target, r=Mark-Simulacrum
removing architecture requirements for RustyHermit
RustHermit and HermitCore is able to run on aarch64 and x86_64. In the future these operating systems will also support RISC-V. Consequently, the dependency to a specific target should be removed.
The build process of `hermit-abi` fails if the architecture isn't supported.
Matthias Krüger [Sat, 19 Feb 2022 23:37:23 +0000 (00:37 +0100)]
Rollup merge of #93686 - dbrgn:trim-on-byte-slices, r=joshtriplett
core: Implement ASCII trim functions on byte slices
Hi ````````@rust-lang/libs!```````` This is a feature that I wished for when implementing serial protocols with microcontrollers. Often these protocols may contain leading or trailing whitespace, which needs to be removed. Because oftentimes drivers will operate on the byte level, decoding to unicode and checking for unicode whitespace is unnecessary overhead.
I did not find any pre-existing discussions about this, which surprises me a bit. Maybe I'm missing something, and this functionality is already possible through other means? There's https://github.com/rust-lang/rfcs/issues/2547 ("Trim methods on slices"), but that has a different purpose.
As per the [std dev guide](https://std-dev-guide.rust-lang.org/feature-lifecycle/new-unstable-features.html), this is a proposed implementation without any issue / RFC. If this is the wrong process, please let me know. However, I thought discussing code is easier than discussing a mere idea, and hacking on the stdlib was fun.
bors [Sat, 19 Feb 2022 23:25:06 +0000 (23:25 +0000)]
Auto merge of #92911 - nbdd0121:unwind, r=Amanieu
Guard against unwinding in cleanup code
Currently the only safe guard we have against double unwind is the panic count (which is local to Rust). When double unwinds indeed happen (e.g. C++ exception + Rust panic, or two C++ exceptions), then the second unwind actually goes through and the first unwind is leaked. This can cause UB. cc rust-lang/project-ffi-unwind#6
E.g. given the following C++ code:
```c++
extern "C" void foo() {
throw "A";
}
This program is well-defined to terminate:
```c++
struct dtor {
~dtor() noexcept(false) {
foo();
}
};
void a() {
dtor a;
dtor b;
}
int main() {
execute(a);
return 0;
}
```
But this Rust code doesn't catch the double unwind:
```rust
extern "C-unwind" {
fn foo();
fn execute(f: unsafe extern "C-unwind" fn());
}
struct Dtor;
impl Drop for Dtor {
fn drop(&mut self) {
unsafe { foo(); }
}
}
extern "C-unwind" fn a() {
let _a = Dtor;
let _b = Dtor;
}
fn main() {
unsafe { execute(a) };
}
```
To address this issue, this PR adds an unwind edge to an abort block, so that the Rust example aborts. This is similar to how clang guards against double unwind (except clang calls terminate per C++ spec and we abort).
The cost should be very small; it's an additional trap instruction (well, two for now, since we use TrapUnreachable, but that's a different issue) for each function with landing pads; if LLVM gains support to encode "abort/terminate" info directly in LSDA like GCC does, then it'll be free. It's an additional basic block though so compile time may be worse, so I'd like a perf run.
Tomasz Miąsko [Thu, 17 Feb 2022 00:00:00 +0000 (00:00 +0000)]
Fix pretty printing of enums without variants
92d20c4aaddea9507f8ad37fe37c551219153bbf removed no-variants special
case from try_destructure_const with expectation that this case would be
handled gracefully when read_discriminant returns an error.
Alas in that case read_discriminant succeeds while returning a
non-existing variant, so the special case is still necessary.
since it sorts a [`ConstraintCategory::ClosureUpvar(HirId)`](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/mir/enum.ConstraintCategory.html#variant.ClosureUpvar).
This PR makes that variant take a [`Field`](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/mir/struct.Field.html) instead.
Matthias Krüger [Sat, 19 Feb 2022 05:45:30 +0000 (06:45 +0100)]
Rollup merge of #93979 - SUPERCILEX:debug_check, r=dtolnay
Add debug assertions to validate NUL terminator in c strings
The `unchecked` variants from the stdlib usually perform the check anyway if debug assertions are on (for example, `unwrap_unchecked`). This PR does the same thing for `CStr` and `CString`, validating the correctness for the NUL byte in debug mode.
bors [Sat, 19 Feb 2022 05:08:13 +0000 (05:08 +0000)]
Auto merge of #94105 - 5225225:destabilise-entry-insert, r=Mark-Simulacrum
Destabilise entry_insert
See: https://github.com/rust-lang/rust/pull/90345
I didn't revert the rename that was done in that PR, I left it as `entry_insert`.
Additionally, before that PR, `VacantEntry::insert_entry` seemingly had no stability attribute on it? I kept the attribute, just made it an unstable one, same as the one on `Entry`.
There didn't seem to be any mention of this in the RELEASES.md, so I don't think there's anything for me to do other than this?
bors [Sat, 19 Feb 2022 02:07:43 +0000 (02:07 +0000)]
Auto merge of #94134 - matthiaskrgr:rollup-b132kjz, r=matthiaskrgr
Rollup of 10 pull requests
Successful merges:
- #89892 (Suggest `impl Trait` return type when incorrectly using a generic return type)
- #91675 (Add MemTagSanitizer Support)
- #92806 (Add more information to `impl Trait` error)
- #93497 (Pass `--test` flag through rustdoc to rustc so `#[test]` functions can be scraped)
- #93814 (mips64-openwrt-linux-musl: correct soft-foat)
- #93847 (kmc-solid: Use the filesystem thread-safety wrapper)
- #93877 (asm: Allow the use of r8-r14 as clobbers on Thumb1)
- #93892 (Only mark projection as ambiguous if GAT substs are constrained)
- #93915 (Implement --check-cfg option (RFC 3013), take 2)
- #93953 (Add the `known-bug` test directive, use it, and do some cleanup)
Matthias Krüger [Fri, 18 Feb 2022 22:23:11 +0000 (23:23 +0100)]
Rollup merge of #93953 - jackh726:known_bug, r=Mark-Simulacrum
Add the `known-bug` test directive, use it, and do some cleanup
cc rust-lang/compiler-team#476
Now tests can be annotated with `known-bug`, which should indicate that the test *should* pass (or at least that the current output is a bug). Adding it relaxes the requirement to add error annotations to the test (though it is still allowed). In the future, this could be extended with further relaxations - with the goal to make adding these tests need minimal effort.
I've used this attribute for the GAT tests added in #93757.
Finally, I've also cleaned up `header.rs` in compiletest a bit, by extracting out a bit of common logic. I've also split out some of the directives into their own consts. This removes a lot of very similar functions from `Config` and makes `TestProps::load_from` read nicer.
I've split these into separate commits, so I in theory could split these into separate PRs if they're controversial, but I think they're pretty straightforward.
Matthias Krüger [Fri, 18 Feb 2022 22:23:10 +0000 (23:23 +0100)]
Rollup merge of #93915 - Urgau:rfc-3013, r=petrochenkov
Implement --check-cfg option (RFC 3013), take 2
This pull-request implement RFC 3013: Checking conditional compilation at compile time (https://github.com/rust-lang/rfcs/pull/3013) and is based on the previous attempt https://github.com/rust-lang/rust/pull/89346 by `@mwkmwkmwk` that was closed due to inactivity.
I have address all the review comments from the previous attempt and added some more tests.
cc https://github.com/rust-lang/rust/issues/82450
r? `@petrochenkov`
Matthias Krüger [Fri, 18 Feb 2022 22:23:09 +0000 (23:23 +0100)]
Rollup merge of #93892 - compiler-errors:issue-92917, r=jackh726,nikomatsakis
Only mark projection as ambiguous if GAT substs are constrained
A slightly more targeted version of #92917, where we only give up with ambiguity if we infer something about the GATs substs when probing for a projection candidate.
fixes #93874
also note (but like the previous PR, does not fix) #91762
r? `@jackh726`
cc `@nikomatsakis` who reviewed #92917
Matthias Krüger [Fri, 18 Feb 2022 22:23:07 +0000 (23:23 +0100)]
Rollup merge of #93847 - solid-rs:fix-kmc-solid-fs-ts, r=yaahc
kmc-solid: Use the filesystem thread-safety wrapper
Fixes the thread unsafety of the `std::fs` implementation used by the [`*-kmc-solid_*`](https://doc.rust-lang.org/nightly/rustc/platform-support/kmc-solid.html) Tier 3 targets.
Neither the SOLID filesystem API nor built-in filesystem drivers guarantee thread safety by default. Although this may suffice in general embedded-system use cases, and in fact the API can be used from multiple threads without any problems in many cases, this has been a source of unsoundness in `std::sys::solid::fs`.
This commit updates the implementation to leverage the filesystem thread-safety wrapper (which uses a pluggable synchronization mechanism) to enforce thread safety. This is done by prefixing all paths passed to the filesystem API with `\TS`. (Note that relative paths aren't supported in this platform.)
Matthias Krüger [Fri, 18 Feb 2022 22:23:05 +0000 (23:23 +0100)]
Rollup merge of #93497 - willcrichton:rustdoc-scrape-test, r=GuillaumeGomez
Pass `--test` flag through rustdoc to rustc so `#[test]` functions can be scraped
As a part of stabilizing the scrape examples extension in Cargo, I uncovered a bug where examples cannot be scraped from tests. See this test: https://github.com/rust-lang/cargo/pull/10343/files#diff-27aa4f012ebfebaaee61498d91d2370de460628405d136b05e77efe61e044679R2496
The issue is that when rustdoc is run on a test file, because `--test` is not passed as a rustc option, then functions annotated with `#[test]` are ignored by the compiler. So this PR changes rustdoc so when `--test` is passed in conjunction with a `--scrape-example-<suffix>` flag, then the `test` field of `rustc_interface::Config` is true.
Matthias Krüger [Fri, 18 Feb 2022 22:23:03 +0000 (23:23 +0100)]
Rollup merge of #91675 - ivanloz:memtagsan, r=nagisa
Add MemTagSanitizer Support
Add support for the LLVM [MemTagSanitizer](https://llvm.org/docs/MemTagSanitizer.html).
On hardware which supports it (see caveats below), the MemTagSanitizer can catch bugs similar to AddressSanitizer and HardwareAddressSanitizer, but with lower overhead.
On a tag mismatch, a SIGSEGV is signaled with code SEGV_MTESERR / SEGV_MTEAERR.
# Usage
`-Zsanitizer=memtag -C target-feature="+mte"`
# Comments/Caveats
* MemTagSanitizer is only supported on AArch64 targets with hardware support
* Requires `-C target-feature="+mte"`
* LLVM MemTagSanitizer currently only performs stack tagging.
Matthias Krüger [Fri, 18 Feb 2022 22:23:02 +0000 (23:23 +0100)]
Rollup merge of #89892 - Nilstrieb:suggest-return-impl-trait, r=jackh726
Suggest `impl Trait` return type when incorrectly using a generic return type
Address #85991
When there is a type mismatch error and the return type is generic, and that generic parameter is not used in the function parameters, suggest replacing that generic with the `impl Trait` syntax.
Nilstrieb [Thu, 14 Oct 2021 19:44:43 +0000 (21:44 +0200)]
Suggest `impl Trait` return type
Address #85991
Suggest the `impl Trait` return type syntax if the user tried to return a generic parameter and we get a type mismatch
The suggestion is not emitted if the param appears in the function parameters, and only get the bounds that actually involve `T: ` directly
It also checks whether the generic param is contained in any where bound (where it isn't the self type), and if one is found (like `Option<T>: Send`), it is not suggested.
This also adds `TyS::contains`, which recursively vistits the type and looks if the other type is contained anywhere
bors [Fri, 18 Feb 2022 18:49:25 +0000 (18:49 +0000)]
Auto merge of #94121 - matthiaskrgr:rollup-6ps95da, r=matthiaskrgr
Rollup of 6 pull requests
Successful merges:
- #92683 (Suggest copying trait associated type bounds on lifetime error)
- #92933 (Deny mixing bin crate type with lib crate types)
- #92959 (Add more info and suggestions to use of #[test] on invalid items)
- #93024 (Do not ICE when inlining a function with un-satisfiable bounds)
- #93613 (Move `{core,std}::stream::Stream` to `{core,std}::async_iter::AsyncIterator`)
- #93634 (compiler: clippy::complexity fixes)
Matthias Krüger [Fri, 18 Feb 2022 15:23:30 +0000 (16:23 +0100)]
Rollup merge of #93024 - compiler-errors:inline-mir-bad-bounds, r=estebank
Do not ICE when inlining a function with un-satisfiable bounds
Fixes #93008
This is kinda a hack... but it's the fix I thought had the least blast-radius.
We use `normalize_param_env_or_error` to verify that the predicates in the param env are self-consistent, since with RevealAll, a bad predicate like `<&'static () as Clone>` will be evaluated with an empty ParamEnv (since it references no generics), and we'll raise an error for it.
Matthias Krüger [Fri, 18 Feb 2022 15:23:29 +0000 (16:23 +0100)]
Rollup merge of #92959 - asquared31415:test-non-fn-help, r=estebank
Add more info and suggestions to use of #[test] on invalid items
This pr changes the diagnostics for using `#[test]` on an item that can't be used as a test to explain that the attribute has no meaningful effect on non-functions and suggests the use of `#[cfg(test)]` for conditional compilation instead.
Example change:
```rs
#[test]
mod test {}
```
previously output
```
error: only functions may be used as tests
--> src/lib.rs:2:1
|
2 | mod test {}
| ^^^^^^^^^^^
```
now outputs
```
error: the `#[test]` attribute may only be used on a non-associated function
--> $DIR/test-on-not-fn.rs:3:1
|
LL | #[test]
| ^^^^^^^
LL | mod test {}
| ----------- expected a non-associated function, found a module
|
= note: the `#[test]` macro causes a a function to be run on a test and has no effect on non-functions
help: replace with conditional compilation to make the item only exist when tests are being run
|
LL | #[cfg(test)]
| ~~~~~~~~~~~~
```
Matthias Krüger [Fri, 18 Feb 2022 15:23:28 +0000 (16:23 +0100)]
Rollup merge of #92683 - jackh726:issue-92033, r=estebank
Suggest copying trait associated type bounds on lifetime error
Closes #92033
Kind of the most simple suggestion to make - we don't try to be fancy. Turns out, it's still pretty useful (the couple existing tests that trigger this error end up fixed - for this error - upon applying the fix).
Jakob Degen [Sun, 12 Dec 2021 02:32:08 +0000 (21:32 -0500)]
Extend uninhabited match branch optimization to also work on fallthrough.
The `uninhabited_enum_branch` miropt now also checks whether the fallthrough
case is inhabited, and if not will ensure that it points to an unreachable
block.
bors [Fri, 18 Feb 2022 10:26:45 +0000 (10:26 +0000)]
Auto merge of #93766 - petrochenkov:doclinkregr, r=camelid,GuillaumeGomez
rustdoc: Collect traits in scope for lang items
Inherent impls on primitive types are not included in the list of all inherent impls in the crate (`inherent_impls_in_crate_untracked`), they are taken from the list of lang items instead, but such impls can also be inlined by rustdoc, e.g. if something derefs to a primitive type.
Mario Carneiro [Fri, 18 Feb 2022 04:27:53 +0000 (20:27 -0800)]
Optimize char_try_from_u32
The optimization was proposed by @falk-hueffner in https://rust-lang.zulipchat.com/#narrow/stream/219381-t-libs/topic/Micro-optimizing.20char.3A.3Afrom_u32/near/272146171, and I simplified it a bit and added an explanation of why the optimization is correct.
bors [Thu, 17 Feb 2022 22:54:18 +0000 (22:54 +0000)]
Auto merge of #94103 - matthiaskrgr:rollup-cd70ofn, r=matthiaskrgr
Rollup of 9 pull requests
Successful merges:
- #93337 (Update tracking issue numbers for inline assembly sub-features)
- #93758 (Improve comments about type folding/visiting.)
- #93780 (Generate list instead of div items in sidebar)
- #93976 (Add MAIN_SEPARATOR_STR)
- #94011 (Even more let_else adoptions)
- #94041 (Add a `try_collect()` helper method to `Iterator`)
- #94043 (Fix ICE when using Box<T, A> with pointer sized A)
- #94082 (Remove CFG_PLATFORM)
- #94085 (Clippy: Don't lint `needless_borrow` in method receiver positions)
Matthias Krüger [Thu, 17 Feb 2022 22:01:01 +0000 (23:01 +0100)]
Rollup merge of #94043 - DrMeepster:box_alloc_ice, r=oli-obk
Fix ICE when using Box<T, A> with pointer sized A
Fixes #78459
Note that using `Box<T, A>` with a more than pointer sized `A` or using a pointer sized `A` with a Box of a DST will produce a different ICE (#92054) which is not fixed by this PR.
Matthias Krüger [Thu, 17 Feb 2022 22:01:00 +0000 (23:01 +0100)]
Rollup merge of #94041 - a-lafrance:try-collect, r=scottmcm
Add a `try_collect()` helper method to `Iterator`
Implement `Iterator::try_collect()` as a helper around `Iterator::collect()` as discussed [here](https://internals.rust-lang.org/t/idea-fallible-iterator-mapping-with-try-map/15715/5?u=a.lafrance).
First time contributor so definitely open to any feedback about my implementation! Specifically wondering if I should open a tracking issue for the unstable feature I introduced.
As the main participant in the internals discussion: r? `@scottmcm`
Matthias Krüger [Thu, 17 Feb 2022 22:00:55 +0000 (23:00 +0100)]
Rollup merge of #93758 - nnethercote:improve-folding-comments, r=BoxyUwU
Improve comments about type folding/visiting.
I have found this code confusing for years. I've always roughly
understood it, but never exactly. I just made my fourth(?) attempt and
finally cracked it.
This commit improves the comments. In particular, it explicitly
describes how you can't do a custom fold/visit of any type; there are
actually a handful of "types of interest" (e.g. `Ty`, `Predicate`,
`Region`, `Const`) that can be custom folded/visted, and all other types
just get a generic traversal. I think this was the part that eluded me
on all my prior attempts at understanding.
The commit also updates comments to account for some newer changes such
as the fallible/infallible folding distinction, does some minor
reorderings, and moves one `impl` to a better place.
Matthias Krüger [Thu, 17 Feb 2022 22:00:55 +0000 (23:00 +0100)]
Rollup merge of #93337 - Amanieu:asm_tracking, r=tmiasko
Update tracking issue numbers for inline assembly sub-features
The main tracking issue for inline assembly is [closed](https://github.com/rust-lang/rust/issues/72016#issuecomment-1022332954), further tracking of the remaining sub-features has been moved to separate tracking issues.