Use translatable diagnostics in `rustc_const_eval`
This PR:
* adds a `no_span` parameter to `note` / `help` attributes when using `Subdiagnostic` to allow adding notes/helps without using a span
* has minor tweaks and changes to error messages
I found this confusing because it includes the root item, plus the
inlined items reachable from the root item. The new formulation
separates the two parts more clearly.
Currently it overwrites all the CGUs with new CGUs. But those new CGUs
are just copies of the old CGUs, possibly with some things added. This
commit changes things so that each CGU just gets added to in place,
which makes things simpler and clearer.
It currently uses ranges, which index into `UsageMap::used_items`. This
commit changes it to just use `Vec`, which is much simpler to construct
and use. This change does result in more allocations, but it is few
enough that the perf impact is negligible.
`UsageMap` contains `used_map`, which maps from an item to the item it
uses. This commit add `user_map`, which is the inverse.
We already compute this inverse, but later on, and it is only held as a
local variable. Its simpler and nicer to put it next to `used_map`.
Currently, the code uses multiple words to describe when a mono item `f`
uses a mono item `g`, all of which have problems.
- `f` references `g`: confusing because there are multiple kinds of use,
e.g. "`f` calls `g`" is one, but "`f` takes a (`&T`-style) reference
of `g`" is another, and that's two subtly different meanings of
"reference" in play.
- `f` accesses `g`: meh, "accesses" makes me think of data, and this is
code.
- `g` is a neighbor (or neighbour) of `f`: is verbose, and doesn't
capture the directionality.
This commit changes the code to use "`f` uses `g`" everywhere. I think
it's better than the current terminology, and the consistency is
important.
Also, `InliningMap` is renamed `UsageMap` because (a) it was always
mostly about usage, and (b) the inlining information it did record was
removed in a recent commit.
Extra context for unreachable_pub lint
While experienced Rustaceans no doubt know this sort of thing already, as more of a newbie I had trouble understanding why I was triggering the lint. Hopefully this expanded explanation saves someone else some head-scratching.
Fixes#110922
`#[cfg]`s are frequently used to gate crate content behind cargo
features. This can lead to very confusing errors when features are
missing. For example, `serde` doesn't have the `derive` feature by
default. Therefore, `serde::Serialize` fails to resolve with a generic
error, even though the macro is present in the docs.
This commit adds a list of all stripped item names to metadata. This is
filled during macro expansion and then, through a fed query, persisted
in metadata. The downstream resolver can then access the metadata to
look at possible candidates for mentioning in the errors.
This slightly increases metadata (800k->809k for the feature-heavy
windows crate), but not enough to really matter.
Enable ConstGoto and SeparateConstSwitch passes by default
These 2 passes implement a limited form of jump-threading.
Filing this PR to see if enabling them would be lighter than https://github.com/rust-lang/rust/pull/107009.
Enable ScalarReplacementOfAggregates in optimized builds
Like MatchBranchSimplification, this pass is known to produce significant runtime improvements in Cranelift artifacts, and I believe based on the perf runs here that the primary effect of this pass is to empower MatchBranchSimplification. ScalarReplacementOfAggregates on its own has little effect on anything, but when this was rebased up to include https://github.com/rust-lang/rust/pull/112001 we started seeing significant and majority-positive results.
Based on the fact that we see most of the regressions in debug builds (https://github.com/rust-lang/rust/pull/112002#issuecomment-1566270144) and some rather significant ones in cycles and wall time, I'm only enabling this in optimized builds at the moment.
Don't compute inlining status of mono items in advance.
We record inlining status for mono items in `MonoItems`, and then transfer it to `InliningMap`, for later use in
`InliningMap::with_inlining_candidates`.
But we can just compute inlining status directly in `InliningMap::with_inlining_candidates`, because the mono item is right there. There's no need to compute it in advance.
This commit changes the code to do that, removing the need for `MonoItems` and `InliningMap::inlines`. This does result in more calls to `instantiation_mode` (one per static occurrence) but the performance effect is negligible.
r? ``@wesleywiser``
Preserve substs in opaques recorded in typeck results
This means that we now prepopulate MIR with opaques with the right substs.
The first commit is a hack that I think we discussed, having to do with `DefiningAnchor::Bubble` basically being equivalent to `DefiningAnchor::Error` in the new solver, so having to use `DefiningAnchor::Bind` instead, lol.
r? `@lcnr`
Add a distinct `OperandValue::ZeroSized` variant for ZSTs
These tend to have special handling in a bunch of places anyway, so the variant helps remember that. And I think it's easier to grok than `Aggregate`s sometimes being `Immediates` (after all, I previously got that wrong and caused #109992). As a minor bonus, it means we don't need to generate poison LLVM values for ZSTs to pass around in `OperandValue::Immediate`s.
Inspired by https://github.com/rust-lang/rust/pull/110021#discussion_r1160486991, so
r? `@compiler-errors`
Replace const eval limit by a lint and add an exponential backoff warning
The lint triggers at the first power of 2 that comes after 1 million function calls or traversed back-edges (takes less than a second on usual programs). After the first emission, an unsilenceable warning is repeated at every following power of 2 terminators, causing it to get reported less and less the longer the evaluation runs.
cc `@rust-lang/wg-const-eval`
fixes#93481closes#67217
These tend to have special handling in a bunch of places anyway, so the variant helps remember that. And I think it's easier to grok than non-Scalar Aggregates sometimes being `Immediates` (like I got wrong and caused 109992). As a minor bonus, it means we don't need to generate poison LLVM values for them to pass around in `OperandValue::Immediate`s.
Uplift `clippy::cast_ref_to_mut` lint
This PR aims at uplifting the `clippy::cast_ref_to_mut` lint into rustc.
## `cast_ref_to_mut`
(deny-by-default)
The `cast_ref_to_mut` lint checks for casts of `&T` to `&mut T` without using interior mutability.
### Example
```rust,compile_fail
fn x(r: &i32) {
unsafe {
*(r as *const i32 as *mut i32) += 1;
}
}
```
### Explanation
Casting `&T` to `&mut T` without interior mutability is undefined behavior, as it's a violation of Rust reference aliasing requirements.
-----
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
-----
For Clippy:
changelog: Moves: Uplifted `clippy::cast_ref_to_mut` into rustc
linker: Report linker flavors incompatible with the current target
The linker flavor is checked for target compatibility even if linker is never used (e.g. we are producing a rlib).
If it causes trouble, we can move the check to `link.rs` so it will run if the linker (flavor) is actually used.
And also feature gate explicitly specifying linker flavors for tier 3 targets.
The next step is supporting all the internal linker flavors in user-visible interfaces (command line and json).
Only rewrite valtree-constants to patterns and keep other constants opaque
Now that we can reliably fall back to comparing constants with `PartialEq::eq` to the match scrutinee, we can
1. eagerly try to convert constants to valtrees
2. then deeply convert the valtree to a pattern
3. if the to-valtree conversion failed, create an "opaque constant" pattern.
This PR specifically avoids any behavioral changes or major cleanups. What we can now do as follow ups is
* move the two remaining call sites to `destructure_mir_constant` off that query
* make valtree to pattern conversion infallible
* this needs to be done after careful analysis of the effects. There may be user visible changes from that.
based on https://github.com/rust-lang/rust/pull/111768
We record inlining status for mono items in `MonoItems`, and then
transfer it to `InliningMap`, for later use in
`InliningMap::with_inlining_candidates`.
But we can just compute inlining status directly in
`InliningMap::with_inlining_candidates`, because the mono item is right
there. There's no need to compute it in advance.
This commit changes the code to do that, removing the need for
`MonoItems` and `InliningMap::inlines`. This does result in more calls
to `instantiation_mode` (one per static occurrence) but the performance
effect is negligible.
Rollup of 5 pull requests
Successful merges:
- #111772 (Fix linkage for large binaries on mips64 platforms)
- #111975 (Stop normalizing so many different prefixes)
- #111979 (Respect CARGOFLAGS in bootstrap.py)
- #112089 (Add `--warnings warn` flag to `x.py`)
- #112103 (Bootstrap update to 1.71 beta)
r? `@ghost`
`@rustbot` modify labels: rollup
Stop normalizing so many different prefixes
Previously, we would normalize *all* of
- the absolute path to the repository checkout
- the /rustc/$sha for stage1 (if `remap-debuginfo` was enabled)
- the /rustc/$sha for download-rustc
- the sysroot for download-rustc
Now, we consistently only normalize /rustc/FAKE_PREFIX. Not only is this much simpler, but it also avoids ongoing maintenance for download-rustc and makes it much less likely that tests break by accident.
- Change `tests/ui/track-diagnostics/track6.rs` to use a relative path instead of an absolute one. I am not actually sure why `track_caller` works here, but it does seem to work 🤷
- Pass `-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX` to all suites, not just UI. In particular, mir-opt tests emit /rustc/ paths in their output.
r? ```@cjgillot``` since you reviewed https://github.com/rust-lang/rust/pull/110699 - this is the test that it doesn't regress :)
Fix linkage for large binaries on mips64 platforms
This pull request fixes the linkage for large binaries on mips64 platforms by enabling the `xgot` feature in LLVM.
It is well understood that the generated binary will gain a hefty performance penalty where the external symbol jumps now cost at least three instructions each.
Also, this pull request does not address the same issue on the mips32 counterparts (due to being unable to test the changes thoroughly).
Should fix#52108
move `super_relate_consts` hack to `normalize_param_env_or_error`
`super_relate_consts` has as hack in it to work around the fact that `normalize_param_env_or_error` is broken. When relating two constants we attempt to evaluate them (aka normalize them). This is not an issue in any way specific to const generics, type aliases also have the same issue as demonstrated in [this code](https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=84b6d3956a2c852a04b60782476b56c9).
Since the hack in `super_relate_consts` only exists to make `normalize_param_env_or_error` emit less errors move it to `normalize_param_env_or_error`. This makes `super_relate_consts` act more like the normal plain structural equality its supposed to and should help ensure that the hack doesnt accidentally affect other situations.
r? `@compiler-errors`
offset_of: don't require type to be `Sized`
Fixes#112051
~~The RFC [explicitly forbids](https://rust-lang.github.io/rfcs/3308-offset_of.html#limitations) non-`Sized` types, but it looks like only the fields being recursed into were checked. The sized check also seemed to have been completely missing for tuples~~
Remove `-Zcgu-partitioning-strategy`.
This option was introduced three years ago, but it's never been meaningfully used, and `default` is the only acceptable value.
Also, I think the `Partition` trait presents an interface that is too closely tied to the existing strategy and would probably be wrong for other strategies. (My rule of thumb is to not make something generic until there are at least two instances of it, to avoid this kind of problem.)
Also, I don't think providing multiple partitioning strategies to the user is a good idea, because the compiler already has enough obscure knobs.
This commit removes the option, along with the `Partition` trait, and the `Partitioner` and `DefaultPartitioning` types. I left the existing code in `compiler/rustc_monomorphize/src/partitioning/default.rs`, though I could be persuaded that moving it into
`compiler/rustc_monomorphize/src/partitioning/mod.rs` is better.
r? ``@wesleywiser``
change `BorrowKind::Unique` to be a mutating `PlaceContext`
fixes#112056
I believe that `BorrowKind::Unique` is a footgun in general, so I added a FIXME and opened https://github.com/rust-lang/rust/issues/112072. This is a bit too involved for this PR though.
refactor and cleanup the leak check, add it to new solver
ended up being a bit more involved than I wanted but is hopefully still easy enough to review as a single PR, can split it into separate ones otherwise.
this can be reviewed commit by commit:
a473d55cdb9284aa2b01282d1b529a2a4d26547b 31a686646534ca006d906ec757ece4e771d6f973 949039c107852a5e36361c08b62821a0613656f5 242917bf5170d9a723c6c8e23e9d9d0c2fa8dc9d ed2b25a7aa28be3184be9e3022c2796a30eaad87 are all pretty straightforward.
03dd83b4c3f4ff27558f5c8ab859bd9f83db1d04 makes it easier to refactor coherence in a later commit, see the commit description, cc `@oli-obk`
4fe311d807a77b6270f384e41689bf5d58f46aec I don't quite remember what we wanted to test here, this definitely doesn't test that the occurs check doesn't cause incorrect errors in coherence, also cc `@oli-obk` here. I may end up writing a new test for this myself later.
5c200d88a91b75bd0875b973150655bd581ef97a is the main refactor of the leak check, changing it to take the `outer_universe` instead of getting it from a snapshot. Using a snapshot requires us to be in a probe which we aren't in the new solver, it also just feels dirty as snapshots don't really have anything to do with universes.
with all of this cfc230d54188d9c7ed867a9a0d1f51be77b485f9 is now kind of trivial.
r? `@nikomatsakis`
Don't typecheck recovered method call from suggestion
Only make the use-dot-operator-to-call-method suggestion, but do not double down and use the recovered type to perform method call typechecking as it will produce confusing diagnostics relevant for the *fixed* code.
### Code Sample
```rust
struct Client;
impl Client {
fn post<T: std::ops::Add>(&self, _: T, _: T) {}
}
fn f() {
let c = Client;
post(c, ());
}
```
### Before This PR
```
error[[E0277]](https://doc.rust-lang.org/stable/error_codes/E0277.html): cannot add `()` to `()`
--> src/lib.rs:9:5
|
9 | post(c, ());
| ^^^^^^^^^^^ no implementation for `() + ()`
|
= help: the trait `Add` is not implemented for `()`
note: required by a bound in `Client::post`
--> src/lib.rs:4:16
|
4 | fn post<T: std::ops::Add>(&self, _: T, _: T) {}
| ^^^^^^^^^^^^^ required by this bound in `Client::post`
error[[E0061]](https://doc.rust-lang.org/stable/error_codes/E0061.html): this function takes 2 arguments but 1 argument was supplied
--> src/lib.rs:9:5
|
9 | post(c, ());
| ^^^^ an argument of type `()` is missing
|
note: method defined here
--> src/lib.rs:4:8
|
4 | fn post<T: std::ops::Add>(&self, _: T, _: T) {}
| ^^^^ ----- ---- ----
help: provide the argument
|
9 | post((), ())(c, ());
| ++++++++
error[[E0425]](https://doc.rust-lang.org/stable/error_codes/E0425.html): cannot find function `post` in this scope
--> src/lib.rs:9:5
|
9 | post(c, ());
| ^^^^ not found in this scope
|
help: use the `.` operator to call the method `post` on `&Client`
|
9 - post(c, ());
9 + c.post(());
|
Some errors have detailed explanations: E0061, E0277, E0425.
For more information about an error, try `rustc --explain E0061`.
```
### After This PR
```
error[E0425]: cannot find function `post` in this scope
--> tests/ui/typeck/issue-106929.rs:9:5
|
9 | post(c, ());
| ^^^^ not found in this scope
|
help: use the `.` operator to call the method `post` on `&Client`
|
9 - post(c, ());
9 + c.post(());
|
error: aborting due to previous error
For more information about this error, try `rustc --explain E0425`.
```
Fixes#106929.
`EarlyBinder::new` -> `EarlyBinder::bind`
for consistency with `Binder::bind`. it may make sense to also add `EarlyBinder::dummy` in places where we know that no parameters exist, but I left that out of this PR.
r? `@jackh726` `@kylematsuda`
fix: dedup `static_candidates` before report
Fixes https://github.com/rust-lang/rust/issues/103646
`record_static_candidate` had been executed twice, resulting in the presence of two identical `CandidateSource::Trait(Cat)` in static_candidates. This PR aims to deduplication the `static_candidates` list, allowing it to execute `suggest_associated_call_syntax` properly.
Uplift `clippy::invalid_utf8_in_unchecked` lint
This PR aims at uplifting the `clippy::invalid_utf8_in_unchecked` lint into two lints.
## `invalid_from_utf8_unchecked`
(deny-by-default)
The `invalid_from_utf8_unchecked` lint checks for calls to `std::str::from_utf8_unchecked` and `std::str::from_utf8_unchecked_mut` with an invalid UTF-8 literal.
### Example
```rust
unsafe {
std::str::from_utf8_unchecked(b"cl\x82ippy");
}
```
### Explanation
Creating such a `str` would result in undefined behavior as per documentation for `std::str::from_utf8_unchecked` and `std::str::from_utf8_unchecked_mut`.
## `invalid_from_utf8`
(warn-by-default)
The `invalid_from_utf8` lint checks for calls to `std::str::from_utf8` and `std::str::from_utf8_mut` with an invalid UTF-8 literal.
### Example
```rust
std::str::from_utf8(b"ru\x82st");
```
### Explanation
Trying to create such a `str` would always return an error as per documentation for `std::str::from_utf8` and `std::str::from_utf8_mut`.
-----
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
-----
For Clippy:
changelog: Moves: Uplifted `clippy::invalid_utf8_in_unchecked` into rustc
we can otherwise assign a hidden type to the opaque which
causes ICE if we don't use `take_opaque_types` during
coherence. This is annoying so I didn't bother. Added a test
showing the behavior this prevents.
Optimize scalar and scalar pair representations loaded from ByRef in llvm
in https://github.com/rust-lang/rust/pull/105653 I noticed that we were generating suboptimal LLVM IR if we had a `ConstValue::ByRef` that could be represented by a `ScalarPair`. Before https://github.com/rust-lang/rust/pull/105653 this is probably rare, but after it, every slice will go down this suboptimal code path that requires LLVM to untangle a bunch of indirections and translate static allocations that are only used once to read a scalar pair from.
Only make the use-dot-operator-to-call-method suggestion, but do not
double down and use the recovered type to perform method call
typechecking as it will produce confusing diagnostics on the "fixed"
code.
This option was introduced three years ago, but it's never been
meaningfully used, and `default` is the only acceptable value.
Also, I think the `Partition` trait presents an interface that is too
closely tied to the existing strategy and would probably be wrong for
other strategies. (My rule of thumb is to not make something generic
until there are at least two instances of it, to avoid this kind of
problem.)
Also, I don't think providing multiple partitioning strategies to the
user is a good idea, because the compiler already has enough obscure
knobs.
This commit removes the option, along with the `Partition` trait, and
the `Partitioner` and `DefaultPartitioning` types. I left the existing
code in `compiler/rustc_monomorphize/src/partitioning/default.rs`,
though I could be persuaded that moving it into
`compiler/rustc_monomorphize/src/partitioning/mod.rs` is better.
Make `TyKind: Debug` have less verbose output
Current `TyKind: Debug` impl is basically unusable for debugging, its too verbose even for verbose debugging 🤣 This PR replaces the debug logic for `TyKind` with a more manual debug impl instead of a hand expanded derived impl. This should help make #107084 more reasonable to land since the output of `Ty: Debug` will be better.
This isn't a fully completed change to the `Debug` impl of `TyKind` as there's still logic from the derive macro for some variants. Some of the variants are also not consisten with the `-Zverbose` printing of `Ty`, ideally `-Zverbose` printing of `Ty` would also just defer to the debug impl instead of having lots of checks in pretty printing. I plan on fixing this in follow up PRs since it seems tricky to do in this one and its already a large PR 😅
Add build instructions for cranelift backend as part of Rust repo
All other instructions assume that user works with separate repository than Rust compiler repository. When one follows default instructions, cranelift codegen tries to use different sys-root and compiler internal crates which leads to compiler errors when building it.
I needed to do all this steps while adding new intrinsic to rustc.
r? bjorn3
Go through an intermediate pair of `cc`and `lld` hints instead of mapping CLI options to `LinkerFlavor` directly, and use the target's default linker flavor as a reference.
Load only the crate header for `locator::crate_matches`
Previously, we used the following info to determine whether to load the crate:
1. The METADATA_HEADER, which includes a METADATA_VERSION constant
2. The embedded rustc version
3. Various metadata in the `CrateRoot`, including the SVH
This worked ok most of the time. Unfortunately, when building locally the rustc version is always
the same because `omit-git-hash` is on by default. That meant that we depended only on 1 and 3, and
we are not very good about bumping METADATA_VERSION (it's currently at 7) so in practice we were
only depending on 3. `CrateRoot` is a very large struct and changes somewhat regularly, so this led
to a steady stream of crashes from trying to load it.
Change the logic to add an intermediate step between 2 and 3: introduce a new `CrateHeader` struct
that contains only the minimum info needed to decide whether the crate should be loaded or not. That
avoids having to load all of `CrateRoot`, which in practice means we should crash much less often.
Note that this works because the SVH should be different between any two dependencies, even if the
compiler has changed, because we use `-Zbinary-dep-depinfo` in bootstrap. See
https://github.com/rust-lang/rust/pull/111329#issuecomment-1538303474 for more details about how the
original crash happened.
Use `Cow` in `{D,Subd}iagnosticMessage`.
Each of `{D,Subd}iagnosticMessage::{Str,Eager}` has a comment:
```
// FIXME(davidtwco): can a `Cow<'static, str>` be used here?
```
This commit answers that question in the affirmative. It's not the most compelling change ever, but it might be worth merging.
This requires changing the `impl<'a> From<&'a str>` impls to `impl From<&'static str>`, which involves a bunch of knock-on changes that require/result in call sites being a little more precise about exactly what kind of string they use to create errors, and not just `&str`. This will result in fewer unnecessary allocations, though this will not have any notable perf effects given that these are error paths.
Note that I was lazy within Clippy, using `to_string` in a few places to preserve the existing string imprecision. I could have used `impl Into<{D,Subd}iagnosticMessage>` in various places as is done in the compiler, but that would have required changes to *many* call sites (mostly changing `&format("...")` to `format!("...")`) which didn't seem worthwhile.
r? `@WaffleLapkin`
Rollup of 5 pull requests
Successful merges:
- #112029 (Recover upon mistyped error on typo'd `const` in const param def)
- #112037 (Add details about `unsafe_op_in_unsafe_fn` to E0133)
- #112039 (compiler: update solaris/illumos to enable tsan support.)
- #112042 (Migrate GUI colors test to original CSS color format)
- #112045 (Followup to #111973)
r? `@ghost`
`@rustbot` modify labels: rollup
Recover upon mistyped error on typo'd `const` in const param def
And add machine-applicable fix for the typo'd `const` keyword.
### Before
```
error: expected one of `,`, `:`, `=`, or `>`, found `N`
--> src/lib.rs:1:18
|
1 | pub fn bar<Const N: u8>() {}
| ^ expected one of `,`, `:`, `=`, or `>`
```
### After This PR
```
error: `const` keyword was mistyped as `Const`
--> test.rs:1:8
|
1 | fn bar<Const N: u8>() {}
| ^^^^^
|
help: use the `const` keyword
|
1 | fn bar<const N: u8>() {}
| ~~~~~
```
Fixes#111941.
Inline derived `hash`
Because most of the other derived functions are inlined: `clone`, `default`, `eq`, `partial_cmp`, `cmp`. The exception is `fmt`, but it tends to not be on hot paths as much.
r? `@ghost`
Each of `{D,Subd}iagnosticMessage::{Str,Eager}` has a comment:
```
// FIXME(davidtwco): can a `Cow<'static, str>` be used here?
```
This commit answers that question in the affirmative. It's not the most
compelling change ever, but it might be worth merging.
This requires changing the `impl<'a> From<&'a str>` impls to `impl
From<&'static str>`, which involves a bunch of knock-on changes that
require/result in call sites being a little more precise about exactly
what kind of string they use to create errors, and not just `&str`. This
will result in fewer unnecessary allocations, though this will not have
any notable perf effects given that these are error paths.
Note that I was lazy within Clippy, using `to_string` in a few places to
preserve the existing string imprecision. I could have used `impl
Into<{D,Subd}iagnosticMessage>` in various places as is done in the
compiler, but that would have required changes to *many* call sites
(mostly changing `&format("...")` to `format!("...")`) which didn't seem
worthwhile.
MIR: opt-in normalization of `BasicBlock` and `Local` numbering
This doesn't matter at all for actual codegen, but after spending some time reading pre-codegen MIR, I was wishing I didn't have to jump around so much in reading post-inlining code.
So this add two passes that are off by default for every mir level, but can be enabled (`-Zmir-enable-passes=+ReorderBasicBlocks,+ReorderLocals`) for humans.
Make `EarlyBinder`'s inner value private
Currently, `EarlyBinder(T)`'s inner value is public, which allows implicitly skipping the binder by indexing into the tuple struct (i.e., `x.0`). `@lcnr` suggested making `EarlyBinder`'s inner value private so users are required to explicitly call `skip_binder` (https://github.com/rust-lang/rust/issues/105779#issuecomment-1549933424) .
This PR makes the inner value private, adds `EarlyBinder::new` for constructing a new instance, and replaces uses of `x.0` with `x.skip_binder()` (or similar). It also adds some documentation to `EarlyBinder::skip_binder` explaining how to skip the binder of `&EarlyBinder<T>` to get `&T` now that the inner value is private (since previously we could just do `&x.0`).
r? `@lcnr`
Use only one shard with a single thread
This changes `Sharded` to only access a single shard using a mask set to `0` when a single thread is used, which leads to cache utilization improvements.
Performance improvement with 1 thread and `cfg(parallel_compiler)`:
<table><tr><td rowspan="2">Benchmark</td><td colspan="1"><b>Before</b></th><td colspan="2"><b>After</b></th></tr><tr><td align="right">Time</td><td align="right">Time</td><td align="right">%</th></tr><tr><td>🟣 <b>clap</b>:check</td><td align="right">1.7402s</td><td align="right">1.7004s</td><td align="right">💚 -2.29%</td></tr><tr><td>🟣 <b>hyper</b>:check</td><td align="right">0.2633s</td><td align="right">0.2550s</td><td align="right">💚 -3.12%</td></tr><tr><td>🟣 <b>regex</b>:check</td><td align="right">0.9716s</td><td align="right">0.9482s</td><td align="right">💚 -2.41%</td></tr><tr><td>🟣 <b>syn</b>:check</td><td align="right">1.5679s</td><td align="right">1.5358s</td><td align="right">💚 -2.05%</td></tr><tr><td>🟣 <b>syntex_syntax</b>:check</td><td align="right">6.0569s</td><td align="right">5.9272s</td><td align="right">💚 -2.14%</td></tr><tr><td>Total</td><td align="right">10.5999s</td><td align="right">10.3666s</td><td align="right">💚 -2.20%</td></tr><tr><td>Summary</td><td align="right">1.0000s</td><td align="right">0.9760s</td><td align="right">💚 -2.40%</td></tr></table>
cc `@SparrowLii`
Don't check for misaligned raw pointer derefs inside Rvalue::AddressOf
From https://github.com/rust-lang/rust/pull/112026#issuecomment-1565686697:
rustc 1.70 (stable next week) added a Mir pass to add pointer alignment checks in debug mode. Adding these checks caused some crates to break, but that was expected, since they contain broken code (https://github.com/rust-lang/rust/issues/111487) for tracking that.
However, the checks added are slightly more aggressive than they should have been. Specifically, they also check the place in an `addr_of!` expression. Whether lack of alignment there is or isn't UB is unclear. This PR modifies the pass to not affect those cases.
I spot checked the crater regressions and the ones I saw were not the case that this PR is modifying. It still seems good to not land anything overaggressive though
Enable MatchBranchSimplification
This pass is one of the small number of benefits from `-Zmir-opt-level=3` that has motivated rustc_codegen_cranelift to use it:
19ed0aade6/compiler/rustc_codegen_cranelift/build_system/build_sysroot.rs (L244-L246)
Cranelift's motivation for this is _runtime_ performance improvements in debug builds. Lifting this pass all the way to `-Zmir-opt-level=1` seems to come without significant perf overhead, so that's what I'm suggesting here.
Add support for LLVM SafeStack
Adds support for LLVM [SafeStack] which provides backward edge control
flow protection by separating the stack into two parts: data which is
only accessed in provable safe ways is allocated on the normal stack
(the "safe stack") and all other data is placed in a separate allocation
(the "unsafe stack").
SafeStack support is enabled by passing `-Zsanitizer=safestack`.
[SafeStack]: https://clang.llvm.org/docs/SafeStack.html
cc `@rcvalle` #39699
Add warn-by-default lint when local binding shadows exported glob re-export item
This PR introduces a warn-by-default rustc lint for when a local binding (a use statement, or a type declaration) produces a name which shadows an exported glob re-export item, causing the name from the exported glob re-export to be hidden (see #111336).
### Unresolved Questions
- [x] ~~Is this approach correct? While it passes the UI tests, I'm not entirely convinced it is correct.~~ Seems to be ok now.
- [x] ~~What should the lint be called / how should it be worded? I don't like calling `use x::*;` or `struct Foo;` a "local binding" but they are `NameBinding`s internally if I'm not mistaken.~~ ~~The lint is called `local_binding_shadows_glob_reexport` for now, unless a better name is suggested.~~ `hidden_glob_reexports`.
Fixes#111336.
rustc driver: Remove argument 0 before at-expansion to prevent ICE
Under Unix-based operating systems, when I execute rustc by setting argv0 to ``@/dev/null`,` it will expand command-line arguments from this file, leading to an empty arglist, which then triggers an ICE by trying to remove first argument.
The panic message is this:
```
thread 'main' panicked at 'range start index 1 out of range for slice of length 0', compiler/rustc_driver/src/lib.rs:972:17
```
My fix is to remove the first argument before expanding arguments.
<details>
<summary>Full backtrace</summary>
```sh
% (exec -a `@/dev/null` `rustup which rustc`)
thread 'main' panicked at 'range start index 1 out of range for slice of length 0', compiler/rustc_driver/src/lib.rs:972:17
stack backtrace:
0: 0x7fcec776659a - std::backtrace_rs::backtrace::libunwind::trace::h595f06c70adcc478
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/std/src/../../backtrace/src/backtrace/libunwind.rs:93:5
1: 0x7fcec776659a - std::backtrace_rs::backtrace::trace_unsynchronized::h177a0149c76cdde9
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
2: 0x7fcec776659a - std::sys_common::backtrace::_print_fmt::hc0701fd2c3530c58
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/std/src/sys_common/backtrace.rs:65:5
3: 0x7fcec776659a - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::hd4cd115d8750fd6c
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/std/src/sys_common/backtrace.rs:44:22
4: 0x7fcec77c839e - core::fmt::write::h93e2f5923c7eca08
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/core/src/fmt/mod.rs:1213:17
5: 0x7fcec7756be5 - std::io::Write::write_fmt::h8162dbb45f0b9e62
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/std/src/io/mod.rs:1682:15
6: 0x7fcec7766365 - std::sys_common::backtrace::_print::h1835ef8a8f9066da
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/std/src/sys_common/backtrace.rs:47:5
7: 0x7fcec7766365 - std::sys_common::backtrace::print::hcb5e6388b9235f41
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/std/src/sys_common/backtrace.rs:34:9
8: 0x7fcec776912f - std::panicking::default_hook::{{closure}}::h9c084969ccf9a722
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/std/src/panicking.rs:267:22
9: 0x7fcec7768e6b - std::panicking::default_hook::h68fa2ba3c3c6c12f
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/std/src/panicking.rs:286:9
10: 0x7fcecaab56e4 - <rustc_driver[f4ad927b3c57833d]::DEFAULT_HOOK::{closure#0}::{closure#0} as core[d16e85342ea223d9]::ops::function::FnOnce<(&core[d16e85342ea223d9]::panic::panic_info::PanicInfo,)>>::call_once::{shim:vtable#0}
11: 0x7fcec776996a - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::h4e6ced11e07d8b24
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/alloc/src/boxed.rs:2002:9
12: 0x7fcec776996a - std::panicking::rust_panic_with_hook::h8d5c434518ef298c
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/std/src/panicking.rs:692:13
13: 0x7fcec77696e9 - std::panicking::begin_panic_handler::{{closure}}::hf33414f5dabf6faf
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/std/src/panicking.rs:579:13
14: 0x7fcec7766a4c - std::sys_common::backtrace::__rust_end_short_backtrace::hc50389427413bb75
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/std/src/sys_common/backtrace.rs:137:18
15: 0x7fcec77693f2 - rust_begin_unwind
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/std/src/panicking.rs:575:5
16: 0x7fcec77c4d43 - core::panicking::panic_fmt::h2de7a7938f816de8
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/core/src/panicking.rs:64:14
17: 0x7fcec77cb492 - core::slice::index::slice_start_index_len_fail_rt::h0c87d85ce11d10f6
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/core/src/slice/index.rs:53:5
18: 0x7fcec77cb416 - core::slice::index::slice_start_index_len_fail::h504609f2a6b168d1
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/core/src/slice/index.rs:41:9
19: 0x7fceca0eca1f - rustc_driver[f4ad927b3c57833d]::handle_options
20: 0x7fceca0e037f - <rustc_driver[f4ad927b3c57833d]::RunCompiler>::run
21: 0x7fceca0dfd0d - <core[d16e85342ea223d9]::panic::unwind_safe::AssertUnwindSafe<rustc_driver[f4ad927b3c57833d]::main::{closure#0}> as core[d16e85342ea223d9]::ops::function::FnOnce<()>>::call_once
22: 0x7fceca17ce89 - rustc_driver[f4ad927b3c57833d]::main
23: 0x564f5f008a87 - rustc_main[f164605d1302e295]::main
24: 0x564f5f008973 - std[3da461b304582a2c]::sys_common::backtrace::__rust_begin_short_backtrace::<fn(), ()>
25: 0x564f5f008969 - <std[3da461b304582a2c]::rt::lang_start<()>::{closure#0} as core[d16e85342ea223d9]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
26: 0x7fcec774795c - core::ops::function::impls::<impl core::ops::function::FnOnce<A> for &F>::call_once::h699977d052768608
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/core/src/ops/function.rs:287:13
27: 0x7fcec774795c - std::panicking::try::do_call::h4e121e623c70f903
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/std/src/panicking.rs:483:40
28: 0x7fcec774795c - std::panicking::try::hf9d919e062bc178a
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/std/src/panicking.rs:447:19
29: 0x7fcec774795c - std::panic::catch_unwind::h7a7b12272684cb97
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/std/src/panic.rs:140:14
30: 0x7fcec774795c - std::rt::lang_start_internal::{{closure}}::hd96b0eb4844b8762
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/std/src/rt.rs:148:48
31: 0x7fcec774795c - std::panicking::try::do_call::h1af1f88f4f92a22c
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/std/src/panicking.rs:483:40
32: 0x7fcec774795c - std::panicking::try::hf20d7abea7f0f097
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/std/src/panicking.rs:447:19
33: 0x7fcec774795c - std::panic::catch_unwind::hb0e084c3a9c042e4
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/std/src/panic.rs:140:14
34: 0x7fcec774795c - std::rt::lang_start_internal::hca9d5c7277f5b67c
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/std/src/rt.rs:148:20
35: 0x564f5f008ab7 - main
36: 0x7fcec74a1790 - <unknown>
37: 0x7fcec74a184a - __libc_start_main
38: 0x564f5f00899e - <unknown>
39: 0x0 - <unknown>
error: internal compiler error: unexpected panic
note: the compiler unexpectedly panicked. this is a bug.
note: we would appreciate a bug report: https://github.com/rust-lang/rust/issues/new?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md
note: rustc 1.68.0 (2c8cc3432 2023-03-06) running on x86_64-unknown-linux-gnu
query stack during panic:
end of query stack
```
</details>
I also checked if I can trigger a similar problem by passing empty argument list to `execve`, but at least under Linux, it seems to always insert an empty first argument if there are none.
Perform MIR type ops locally in new solver
The new solver already does caching, and it's generally more correct to be using the infcx of the MIR typeck (which has the defining anchor set correctly and has already initialized all the opaques from HIR typeck).
This is based on #111918 so look at the final 3 commits.
This actually causes some tests to go from passing to failing, and failing to passing. Here's the full diff: https://www.diffchecker.com/hB4bh1A9/
Putting this up for exposure mostly.
r? `@lcnr`
