Previously, directly tagged enums had a `variant$` field which would
show the name of the active variant. We now show the variant using a
`[variant]` synthetic item just like we do for niche-layout enums.
In some projects (e.g. kernel), floating point is forbidden. They can disable
hardware floating point support and use `+soft-float` to avoid fp instructions
from being generated, but as libcore contains the formatting code for `f32`
and `f64`, some fp intrinsics are depended. One could define stubs for these
intrinsics that just panic [1], but it means that if any formatting functions
are accidentally used, mistake can only be caught during the runtime rather
than during compile-time or link-time, and they consume a lot of space without
LTO.
This patch provides an unstable cfg `no_fp_fmt_parse` to disable these.
A panicking stub is still provided for the `Debug` implementation (unfortunately)
because there are some SIMD types that use `#[derive(Debug)]`.
[1]: https://lkml.org/lkml/2021/4/14/1028
Rollup of 7 pull requests
Successful merges:
- #84029 (add `track_path::path` fn for usage in `proc_macro`s)
- #85001 (Merge `sys_common::bytestring` back into `os_str_bytes`)
- #86308 (Docs: clarify that certain intrinsics are not unsafe)
- #86796 (Add a regression test for issue-70703)
- #86803 (Remove & from Command::args calls in documentation)
- #86807 (Fix double import in wasm thread )
- #86813 (Add a help message to `unused_doc_comments` lint)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Add a help message to `unused_doc_comments` lint
Fixes#83492
This adds a help message to suggest a plain comment like the E0658 error. I've yet to come up with the best message about the doc attribute but the current shouldn't harm anything.
I was thinking of recovering in the `doc_comment_between_if_else` case, but I came to the conclusion that it unlikely happened and was an overkill.
Fix double import in wasm thread
The `unsupported` type is imported two times, as `super::unsupported` and as `crate::sys::unsupported`, throwing an error. Remove `super::unsupported` in favor of the other.
As reported in #86802.
Fix#86802
Remove & from Command::args calls in documentation
Now that arrays implement `IntoIterator`, using `&` is no longer necessary. This makes examples easier to understand.
Merge `sys_common::bytestring` back into `os_str_bytes`
`bytestring` contains code for correctly debug formatting a byte slice (`[u8]`). This functionality is and has historically only been used to provide the debug formatting of byte-based os-strings (on unix etc.).
Having this functionality in the separate `bytestring` module was useful in the past to reduce duplication, as [when it was added](https://github.com/rust-lang/rust/pull/46798) `os_str_bytes` was still split into `sys::{unix, redox, wasi, etc.}::os_str`. However, now that is no longer the case, there is not much reason for the `bytestring` functionality to be separate from `os_str_bytes`; I don't think it is very likely that another part of std will need to handle formatting byte strings that are not os-strings in the future (everything should be `utf8`). This is why this PR merges the functionality of `bytestring` directly into the debug implementation in `os_str_bytes`.
add `track_path::path` fn for usage in `proc_macro`s
Adds a way to declare a dependency on external files without including them, to either re-trigger the build of a file as well as covering the use case of including dependencies within the `rustc` invocation, such that tools like `sccache`/`cachepot` are able to handle references to external files which are not included.
Ref #73921
Improve debug symbol names to avoid ambiguity and work better with MSVC's debugger
There are several cases where names of types and functions in the debug info are either ambiguous, or not helpful, such as including ambiguous placeholders (e.g., `{{impl}}`, `{{closure}}` or `dyn _'`) or dropping qualifications (e.g., for dynamic types).
Instead, each debug symbol name should be unique and useful:
* Include disambiguators for anonymous `DefPathDataName` (closures and generators), and unify their formatting when used as a path-qualifier vs item being qualified.
* Qualify the principal trait for dynamic types.
* If there is no principal trait for a dynamic type, emit all other traits instead.
* Respect the `qualified` argument when emitting ref and pointer types.
* For implementations, emit the disambiguator.
* Print const generics when emitting generic parameters or arguments.
Additionally, when targeting MSVC, its debugger treats many command arguments as C++ expressions, even when the argument is defined to be a symbol name. As such names in the debug info need to be more C++-like to be parsed correctly:
* Avoid characters with special meaning (`#`, `[`, `"`, `+`).
* Never start a name with `<` or `{` as this is treated as an operator.
* `>>` is always treated as a right-shift, even when parsing generic arguments (so add a space to avoid this).
* Emit function declarations using C/C++ style syntax (e.g., leading return type).
* Emit arrays as a synthetic `array$<type, size>` type.
* Include a `$` in all synthetic types as this is a legal character for C++, but not Rust (thus we avoid collisions with user types).
They are infallible, and could not be actually used because
they will trigger an error when monomorphized, but it is better
to just remove them.
Link: https://github.com/Rust-for-Linux/linux/pull/402
Suggested-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
The `unsupported` type is imported two times, as `super::unsupported` and as `crate::sys::unsupported`, throwing an error. Remove `super::unsupported` in favor of the other.
Document rustfmt on nightly-rustc
- Refactor the doc step for Rustdoc into a macro
- Call the macro for both rustdoc and rustfmt
- Add a `recursion_limit` macro to avoid overflow errors
This does not currently pass --document-private-items for rustfmt due to https://github.com/rust-lang/cargo/pull/8422#issuecomment-871082935.
r? `@Mark-Simulacrum` cc `@calebcartwright`
Add linked list cursor end methods
I add several methods to `LinkedList::CursorMut` and `LinkedList::Cursor`. These methods allow you to access/manipulate the ends of a list via the cursor. This is especially helpful when scanning through a list and reordering. For example:
```rust
let mut c = ll.back_cursor_mut();
let mut moves = 10;
while c.current().map(|x| x > 5).unwrap_or(false) {
let n = c.remove_current();
c.push_front(n);
if moves > 0 { break; } else { moves -= 1; }
}
```
I encountered this problem working on my bachelors thesis doing graph index manipulation.
While this problem can be avoided by splicing, it is awkward. I asked about the problem [here](https://internals.rust-lang.org/t/linked-list-cursurmut-missing-methods/14921/4) and it was suggested I write a PR.
All methods added consist of
```rust
Cursor::front(&self) -> Option<&T>;
Cursor::back(&self) -> Option<&T>;
CursorMut::front(&self) -> Option<&T>;
CursorMut::back(&self) -> Option<&T>;
CursorMut::front_mut(&mut self) -> Option<&mut T>;
CursorMut::back_mut(&mut self) -> Option<&mut T>;
CursorMut::push_front(&mut self, elt: T);
CursorMut::push_back(&mut self, elt: T);
CursorMut::pop_front(&mut self) -> Option<T>;
CursorMut::pop_back(&mut self) -> Option<T>;
```
#### Design decisions:
I tried to remain as consistent as possible with what was already present for linked lists.
The methods `front`, `front_mut`, `back` and `back_mut` are identical to their `LinkedList` equivalents.
I tried to make the `pop_front` and `pop_back` methods work the same way (vis a vis the "ghost" node) as `remove_current`. I thought this was the closest analog.
`push_front` and `push_back` do not change the "current" node, even if it is the "ghost" node. I thought it was most intuitive to say that if you add to the list, current will never change.
Any feedback would be welcome 😄
Revert "Don't load all extern crates unconditionally"
Fixes https://github.com/rust-lang/rust/issues/84738.
This reverts https://github.com/rust-lang/rust/pull/83738.
For the "smart" load of external crates, we need to be able to access their items in order to check their doc comments, which seems, if not impossible, quite complicated using only the AST.
For some context, I first tried to extend the `IntraLinkCrateLoader` visitor by adding `visit_foreign_item`. Unfortunately, it never enters into this call, so definitely not the right place...
I then added `visit_use_tree` to then check all the imports outside with something like this:
```rust
let mut loader = crate::passes::collect_intra_doc_links::IntraLinkCrateLoader::new(resolver);
ast::visit::walk_crate(&mut loader, krate);
let mut items = Vec::new();
for import in &loader.imports_to_check {
if let Some(item) = krate.items.iter().find(|i| i.id == *import) {
items.push(item);
}
}
for item in items {
ast::visit::walk_item(&mut item);
for attr in &item.attrs {
loader.check_attribute(attr);
}
}
```
This was, of course, a failure. We find the items without problems, but we still can't go into the external crate to check its items' attributes.
Finally, `@jyn514` suggested to look into the [`CrateLoader`](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_metadata/creader/struct.CrateLoader.html), but it only seems to provide metadata (I went through [`CStore`](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_metadata/creader/struct.CStore.html) and [`CrateMetadata`](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_metadata/rmeta/decoder/struct.CrateMetadata.html)).
I think we are too limited here (with AST only) to be able to determine the crates we actually need to import, but it's very likely that I missed something. Maybe `@petrochenkov` or `@Aaron1011` have an idea?
So until we find a way to make it work completely, we need to revert it to fix the ICE. Once merged, we'll need to re-open #68427.
r? `@jyn514`
Redefine `ErrorKind::Other` and stop using it in std.
This implements the idea I shared yesterday in the libs meeting when we were discussing how to handle adding new `ErrorKind`s to the standard library: This redefines `Other` to be for *user defined errors only*, and changes all uses of `Other` in the standard library to a `#[doc(hidden)]` and permanently `#[unstable]` `ErrorKind` that users can not match on. This ensures that adding `ErrorKind`s at a later point in time is not a breaking change, since the user couldn't match on these errors anyway. This way, we use the `#[non_exhaustive]` property of the enum in a more effective way.
Open questions:
- How do we check this change doesn't cause too much breakage? Will a crate run help and be enough?
- How do we ensure we don't accidentally start using `Other` again in the standard library? We don't have a `pub(not crate)` or `#[deprecated(in this crate only)]`.
cc https://github.com/rust-lang/rust/pull/79965
cc `@rust-lang/libs` `@ijackson`
r? `@dtolnay`
Implement printing of stack traces on LLVM segfaults and aborts
Implement #79153
Based on discussion, try to extend the rust_backtrace=1 feature to handle segfault or aborts in the llvm backend
Add stderr_locked, stdin_locked, and stdout_locked free functions
to obtain owned locked stdio handles in a single step. Also add
into_lock methods to consume a stdio handle and return an owned
lock. These methods will make it easier to use locked stdio
handles without having to deal with lifetime problems or keeping
bindings to the unlocked handles around.
Include terminators in instance size estimate
For example, drop glue generated for struct below, doesn't have any
statements, only terminators. Previously it received an estimate of 0,
the new estimate is 13 (6+5 drop terminators, +1 resume, +1 return).
```rust
struct S {
a: String,
b: String,
c: String,
d: String,
e: String,
f: String,
}
```
Originally reported in https://github.com/rust-lang/rust/issues/69382#issue-569392141
The recursion_limit attribute avoids the following error:
```
error[E0275]: overflow evaluating the requirement `std::ptr::Unique<rustc_ast::Pat>: std::marker::Send`
|
= help: consider adding a `#![recursion_limit="256"]` attribute to your crate (`rustfmt_nightly`)
```
Allow anyone to add or remove any label starting with perf-
In order to fully realize planned changes to the performance tracking process, we'd like to allow anyone to change the perf related labels.
r? ``@Mark-Simulacrum``
Test for const trait impls behind feature gates
- Make the previous cross-crate tests use revisions instead of being separate files
- Added test for gating const trait impls.
cc ``@oli-obk`` ``@jonas-schievink``
