ignore head usages from ignored candidates
Fixes https://github.com/rust-lang/trait-system-refactor-initiative/issues/210. The test now takes 0.8s to compile, which seems good enough to me. We are actually still walking the entire graph here, we're just avoiding unnecessary reruns.
The basic idea is that if we've only accessed a cycle head inside of a candidate which didn't impact the final result of our goal, we don't need to rerun that cycle head even if is the used provisional result differs from the final result.
We also use this information when rebasing goals over their cycle heads. If a goal doesn't actually depend on the result of that cycle head, rebasing always succeeds. However, we still need to make sure we track the fact that we relied on the cycle head at all to avoid query instability.
It is implemented by tracking the number of `HeadUsages` for every head while evaluating goals. We then also track the head usages while evaluating a single candidate, which the search graph returns as `CandidateHeadUsages`. If there is now an always applicable candidate candidate we know that all other candidates with that source did not matter. We then call `fn ignore_candidate_head_usages` to remove the usages while evaluating this single candidate from the total. If the final `HeadUsages` end up empty, we know that the result of this cycle head did not matter when evaluating its nested goals.
coverage: Remove intermediate data structures from mapping creation
The data structures in `coverage::mappings` were historically very useful for isolating the details of mapping-extraction from the details of how coverage mappings are stored in MIR.
But because of various changes that have taken place over time, they now provide little value, and cause difficulty for the coordinated changes that will be needed for introducing expansion mapping support.
In the future, the pendulum might eventually swing back towards these being useful again, but we can always reintroduce suitable intermediate data structures if and when that happens. For now, the simplicity of not having this intermediate layer is a higher priority.
There should be no changes to compiler output.
Add `FnContext` in parser for diagnostic
Fixesrust-lang/rust#144968
Inspired by https://github.com/rust-lang/rust/issues/144968#issuecomment-3156094581, I implemented `FnContext` to indicate whether a function should have a self parameter, for example, whether the function is a trait method, whether it is in an impl block. And I removed the outdated note.
I made two commits to show the difference.
cc ``@estebank`` ``@djc``
r? compiler
Resolve the prelude import in `build_reduced_graph`
This pr tries to resolve the prelude import at the `build_reduced_graph` stage.
Part of batched import resolution in rust-lang/rust#145108 (cherry picked commit) and maybe needed for rust-lang/rust#139493.
r? petrochenkov
llvm: Accept new LLVM lifetime format
In llvm/llvm-project#150248 LLVM removed the size parameter from the lifetime format. Tolerate not having that size parameter.
strip prefix of temporary file names when it exceeds filesystem name length limit
When doing lto, rustc generates filenames that are concatenating many information.
In the case of this testcase, it is concatenating crate name and rust file name, plus some hash, and the extension. In some other cases it will concatenate even more information reducing the maximum effective crate name to about 110 chars on linux filesystems where filename max length is 255
This commit is ensuring that the temporary file names are limited in size, while still reasonably ensuring the unicity (with hashing of the stripped part)
Fix: rust-lang/rust#49914
Fix description of unsigned `checked_exact_div`
Like its signed counterpart, this function does not panic. Also, fix the examples to document how it returns Some/None.
E0793: Clarify that it applies to unions as well
pick up inactive PR: https://github.com/rust-lang/rust/pull/131472
Also:
Adjust the language slightly to be more consistent with other similar messages (was created instead of got created).
Add a short section on union.
Add an example line showing referencing a field in a packed struct is safe if the field's type isn't more strictly aligned than the pack.
r? compiler-errors
Fix tail calls to `#[track_caller]` functions
We want `#[track_caller]` to be semver independent, i.e. it should not be a breaking change to add or remove it. Since it changes ABI of a function (adding an additional argument) we have to be careful to preserve this property when adding tail calls.
The only way to achieve this that I can see is:
- we forbid tail calls in functions which are marked with `#[track_caller]` (already implemented)
- tail-calling a `#[track_caller]` marked function downgrades the tail-call to a normal call (or equivalently tail-calls the shim made by fn def to fn ptr cast) (this pr)
Ideally the downgrade would be performed by a MIR pass, but that requires post mono MIR opts (cc ```@saethlin,``` rust-lang/rust#131650). For now I've changed code in cg_ssa to accomodate this behaviour (+ added a hack to mono collector so that the shim is actually generated)
Additionally I added a lint, although I don't think it's strictly necessary.
Alternative to rust-lang/rust#144762 (and thus closesrust-lang/rust#144762)
Fixes https://github.com/rust-lang/rust/issues/144755
compiler: Allow `extern "interrupt" fn() -> !`
While reviewing rust-lang/rust#142633 I overlooked a few details because I was kind of excited.
- Fixesrust-lang/rust#143072
Implement autodiff using intrinsics
This PR aims to move autodiff logic to `autodiff` intrinsic. Allowing us to delete a great part of our frontend code and overall, simplify the compilation pipeline of autodiff functions.
Change the desugaring of `assert!` for better error output
In the desugaring of `assert!`, we now expand to a `match` expression instead of `if !cond {..}`.
The span of incorrect conditions will point only at the expression, and not the whole `assert!` invocation.
```
error[E0308]: mismatched types
--> $DIR/issue-14091.rs:2:13
|
LL | assert!(1,1);
| ^ expected `bool`, found integer
```
We no longer mention the expression needing to implement the `Not` trait.
```
error[E0308]: mismatched types
--> $DIR/issue-14091-2.rs:15:13
|
LL | assert!(x, x);
| ^ expected `bool`, found `BytePos`
```
Now `assert!(val)` desugars to:
```rust
match val {
true => {},
_ => $crate::panic::panic_2021!(),
}
```
Fix#122159.
Patterns: represent constants as valtrees
Const patterns are always valtrees now. Let's represent that in the types. We use `ty::Value` for this since it nicely packages value and type, and has some convenient methods.
Cc `@Nadrieril` `@BoxyUwU`
Use `default_field_values` in `Resolver`
Change `Resolver` to use `feature(default_field_values)`. This change is non-exhaustive, as fields may have been added since I made this commit, and `Fx(Index/Hash)(Map/Set)` types would need to have a `const` constructable to change the majority of the fields left over.
Using default field values should make it easier to review when we add or remove fields to `Resolver` in the future, and highlight which fields are run-time dependent in `Resolver::new`.
r? ``@petrochenkov``
bootstrap: Fix jemalloc 64K page support for aarch64 tools
Resolvesrust-lang/rust#133748
The prior page size fix only targeted the compile build step, not the tools step: https://github.com/rust-lang/rust/pull/135081
Also note that since `miri` always uses jemalloc, I didn't copy the `builder.config.jemalloc(target)` check to the tools section.
Tested by running `strings` on the compiled `miri` binary to see the LG_PAGE value.
Before:
```
> strings miri | grep '^LG_PAGE'
LG_PAGE 14
```
After:
```
> strings miri | grep '^LG_PAGE'
LG_PAGE 16
```
May also need a separate fix for the standalone miri repository: https://github.com/rust-lang/miri/issues/4514 (likely a change needed in miri-script?)
Rename and document `ONLY_HOSTS` in bootstrap
Everytime I examined the `ONLY_HOSTS` flag of bootstrap steps, I was utterly confused. Why is it called ONLY_HOSTS? How does the fact that it is skipped if `--target` is passed, but `--host` is not (which was not accurate) help me?
The reality of the flag is that if it is true, the targets for which the given Step will be built is determined based on the `--host` flag, while if it is false, it is determined based on the `--target` flag, that's pretty much it. The previous comment was just a (not very helpful and not even accurate) corollary of that.
I clarified the comment, and also renamed the flag to `IS_HOST` (happy to brainstorm better names, but the doc. comment change is IMO the main improvement).
r? ``@jieyouxu``
Improve tracing in bootstrap
I was annoyed that bootstrap had like 5 separate ways of debugging/tracing/profiling, and it was hard for me to understand how are individual steps executed. This PR tries to unify severla things behind `BOOTSTRAP_TRACING`, and improve tracing/profiling in general:
- All generated tracing outputs are now stored in a single directory to make it easier to examine them, plus bootstrap prepares a `latest` symlink to the latest generated tracing output directory for convenience.
- All executed spans are now logged automatically (without requiring usage of `#[tracing::instrument]`).
- A custom span/event formatter was implemented, to provide domain-specific output (like location of executed commands or spans) and hopefully also to reduce visual clutter.
- `tracing_forest` was removed. While it did some useful postprocessing, it didn't expose enough information for making the dynamic step spans work.
- You can now explicitly log steps (`STEP=info`) and/or commands (`COMMAND=info`), to have more granular control over what gets logged.
- `print-step-timings` also show when a step starts its execution (not just when it ends it), so that when some step fails in CI, we can actually see what step it was (before we would only see the end of the previous step).
- The rustc-dev-guide page on debugging/profiling bootstrap was updated.
There are still some things that work outside of tracing (`print-step-timings` and `dump-bootstrap-shims`), but I think that for now this improvement is good enough.
I removed the `> step`, `< step` verbose output, because I found it unusable, as verbose bootstrap output also enables verbose Cargo output, and then you simply drown in too much data, and because I think that the new tracing system makes it obsolete (although it does require recompilation with the `tracing` feature). If you want to keep it, happy to revert 690c781475. And the information about cached steps is now also shown in the Graphviz step dependency graph.
We can modify the tracing output however we want, as we now implement it ourselves. Notably, we could also show exit logs for step spans, currently I only show enter spans. Maybe creating indents for each executed nested command is also not needed. Happy to hear feedback!
Some further improvements could be to print step durations, if we decide to also log step exit events. We could also try to enable tracing in CI logs, but it might be too verbose.
Best reviewed commit-by-commit.
r? ``@jieyouxu``
CC ``@Shourya742``
cfg_select: Support unbraced expressions
Tracking issue for `cfg_select`: rust-lang/rust#115585
When operating on expressions, `cfg_select!` can now handle expressions
without braces. (It still requires braces for other things, such as
items.)
Expand the test coverage and documentation accordingly.
---
I'm not sure whether deciding to extend `cfg_select!` in this way is T-lang or T-libs-api. I've labeled for both, with the request that both teams don't block on each other. :)
Fix test intrinsic-raw_eq-const-bad for big-endian
The test fails on s390x and presumably other big-endian systems, due to print of raw values. To fix the tests remove the raw output values in the error note with normalize-stderr.
Include whitespace in "remove |" suggestion and make it hidden
Tweak error rendering of patterns with an extra `|` on either end.
Built on #137409. Only last commit is relevant.
? ``@compiler-errors``
Rework target checking for built-in attributes
This is a refactoring of target checking for built-in attributes.
This PR has the following goals:
- Only refactor the 80% of the attributes that are simple to target check. More complicated ones like `#[repr]` will be in a future PR. Tho I have written the code in such a way that this will be possible to add in the future.
- No breaking changes.
- This part of the codebase is not very well tested though, we can do a crater run if we want to be sure.
- I've spotted quite a few weird situations (like I don't think an impl block should be deprecated?). We can propose fixing these to in a future PR
Fixes https://github.com/rust-lang/rust/issues/143780
Fixes https://github.com/rust-lang/rust/issues/138510
I've split it in commits and left a description on some of the commits to help review.
r? `@jdonszelmann`
