memrchr: Correct aligned offset computation
The memrchr fallback did not compute the offset correctly. It was
intentioned to land on usize-aligned addresses but did not.
This was suspected to have resulted in a crash on ARMv7!
This bug affected non-linux platforms.
I think like this, if we have a slice with pointer `ptr` and length
`len`, we want to find the last usize-aligned offset in the slice.
The correct computation should be:
For example if ptr = 1 and len = 6, and `size_of::<usize>()` is 4:
```
[ x x x x x x ]
1 2 3 4 5 6
^-- last aligned address at offset 3 from the start.
```
The last aligned address is ptr + len - (ptr + len) % usize_size.
Compute offset from the start as:
offset = len - (ptr + len) % usize_size = 6 - (1 + 6) % 4 = 6 - 3 = 3.
I believe the function's return value was always correct previously, if
the platform supported unaligned addresses.
Fixes#35967
`ty::Predicate` was being used as a key for a hash map, but its hash
implementation indirectly hashed addresses, which vary between each
compiler run. This is fixed by sorting predicates by their ID before
encoding them.
In my tests, rustc is now able to produce deterministic results when
compiling libcore and libstd.
I've beefed up `run-make/reproducible-build` to compare the produced
artifacts bit-by-bit. This doesn't catch everything, but should be a
good start.
cc #34902
* A step towards #34902
* More stable error messages in some places related to crate loading
* Possible slight performance improvements since all `HashMap`s
replaced had small keys where `FnvHashMap` should be faster
(although I didn't measure)
rustc_borrowck: Don't hash types in loan paths
1) Types for equal loan paths are not always equal, they can sometimes differ in lifetimes, making equal loan paths hash differently.
Example:
71bdeea561/src/libcollections/linked_list.rs (L835-L856)
One of `self.list`s has type
```
&ReFree(CodeExtent(15013/CallSiteScope { fn_id: 18907, body_id: 18912 }), BrNamed(0:DefIndex(3066), 'a(397), WontChange)) mut linked_list::LinkedList<T>
```
and other has type
```
&ReScope(CodeExtent(15018/Remainder(BlockRemainder { block: 18912, first_statement_index: 0 }))) mut linked_list::LinkedList<T>
```
(... but I'm not sure it's not a bug actually.)
2) Not hashing types is faster than hashing types.
r? @arielb1
Combine types and regions in Substs into one interleaved list.
Previously, `Substs` would contain types and regions, in two separate vectors, for example:
```rust
<X as Trait<'a, 'b, A, B>>::method::<'p, 'q, T, U>
/* corresponds to */
Substs { regions: ['a, 'b, 'p, 'q], types: [X, A, B, T, U] }
```
This PR continues the work started in #35605 by further removing the distinction.
A new abstraction over types and regions is introduced in the compiler, `Kind`.
Each `Kind` is a pointer (`&TyS` or `&Region`), with the lowest two bits used as a tag.
Two bits were used instead of just one (type = `0`, region = `1`) to allow adding more kinds.
`Substs` contain only a `Vec<Kind>`, with `Self` first, followed by regions and types (in the definition order):
```rust
Substs { params: [X, 'a, 'b, A, B, 'p, 'q, T, U] }
```
The resulting interleaved list has the property of being the concatenation of parameters for the (potentially) nested generic items it describes, and can be sliced back into those components:
```rust
params[0..5] = [X, 'a, 'b, A, B] // <X as Trait<'a, 'b, A, B>>
params[5..9] = ['p, 'q, T, U] // <_>::method::<'p, 'q, T, U>
```
r? @nikomatsakis
Improve error message when failing to parse a block
We want to catch this error:
```
if (foo)
bar;
```
as it's valid syntax in other languages, and say how to fix it.
Unfortunately it didn't care if the suggestion made sense and just
highlighted the unexpected token.
Now it attempts to parse a statement, and if it succeeds, it shows the
help message.
Fixes#35907
Remove style guide.
We originally imported this into the repository with the intent of
fixing it up. Instead, nothing happened.
Its appearance on rust-lang.org makes it seem semi-official, but it's
not. The rustfmt strike team will end up producing something like this
anyway, and leaving it around does nothing but mislead people.
r? @aturon
A new target, `s390x-unknown-linux-gnu`, has been added to the compiler
and can be used to build no_core/no_std Rust programs.
Known limitations:
- librustc_trans/cabi_s390x.rs is missing. This means no support for
`extern "C" fn`.
- No support for this arch in libc. This means std can be cross compiled
for this target.
[MIR] track Location in MirVisitor, combine Location
All the users of MirVisitor::visit_statement implement their own statement index tracking. This PR move the tracking into MirVisitor itself.
Also, there were 2 separate implementations of Location that were identical. This PR eliminates one of them.
Do not emit "class method" debuginfo for types that are not DICompositeType.
Fixes#35991 by restricting the "class method" debuginfo sugar from #33358 to structs and enums only.
r? @michaelwoerister
With this commit one can build no_core (and probably no_std as well)
Rust programs for these targets. It's not yet possible to cross compile
std for these targets because rust-lang/libc doesn't know about the
mips64 architecture.
These targets have been tested by cross compiling the "smallest hello"
program (see code below) and then running it under QEMU.
``` rust
#![feature(start)]
#![feature(lang_items)]
#![feature(no_core)]
#![no_core]
#[link(name = "c")]
extern {
fn puts(_: *const u8);
}
#[start]
fn start(_: isize, _: *const *const u8) -> isize {
unsafe {
let msg = b"Hello, world!\0";
puts(msg as *const _ as *const u8);
}
0
}
#[lang = "copy"]
trait Copy {}
#[lang = "sized"]
trait Sized {}
```
This pull request is based on the discussion in PR #35927.
Add a module-level note that `&&` and `||` are short-circuiting operators and not overloadable.
Add a simple `Scalar` example that lifts the `&` operator to a trivial struct tuple.
Make `BooleanVector` a struct tuple.
Derive `PartialEq` for `BooleanVector` instead of implementing it.
Adds a `fn main` wrapper so that the example can integrate with Rust Playground.
simplified bitand expression
add a comment explaining what "rhs" means
PR #35695 for `Range` was approved, so it seems that this side-effect-free style is preferred for Range* examples. This PR performs the same translation for `RangeFrom` and `RangeInclusive`. It also removes what looks to be an erroneously commented line for `#![feature(step_by)]`, and an unnecessary primitive-type annotation in `0u8..`.
add `fn main` wrappers to enable Rust Playground "Run" button
Buffer unix and lock windows to prevent message interleaving
When cargo does a build on multiple processes, multiple crates may error at the same time. If this happens, currently you'll see interleaving of the error messages, which makes for an unreadable message.
Example:
```
--> --> src/bin/multithread-unix.rs:16:35src/bin/singlethread.rs:16:24
||
1616 | | Server::new(&addr).workers(8). Server::new(&addr).serveserve(|r: Request| {(|r: Request| {
| | ^^^^^^^^^^ expected struct `std::io::Error`, found () expected struct `std::io::Error`, found ()
||
= = notenote: expected type `std::io::Error`: expected type `std::io::Error`
= = notenote: found type `()`: found type `()`
= = notenote: required because of the requirements on the impl of `futures_minihttp::Service<futures_minihttp::Request, futures_minihttp::Response>` for `[closure@src/bin/multithread-unix.rs:16:41: 22:6]`: required because of the requirements on the impl of `futures_minihttp::Service<futures_minihttp::Request, futures_minihttp::Response>` for `[closure@src/bin/singlethread.rs:16:30: 22:6]`
error: aborting due to previous error
error: aborting due to previous error
```
This patch uses two techniques to prevent this interleaving. On Unix systems, since they use the text-based ANSI protocol for coloring, we can safely buffer up whole messages before we emit. This PR does this buffering, and emits the whole message at once.
On Windows, term must use the Windows terminal API to color the output. This disallows us from using the same buffering technique. Instead, here we grab a Windows mutex (thanks to @alexcrichton for the lock code). This lock only works in Windows and will hold a mutex for the duration of a message output.
r? @nikomatsakis
modify fds-are-cloexec test to open a file that exists
Fixes#35753.
Is it a valid assumption that the current directory is always the root of the repo when the tests are run?
r? @nagisa
We originally imported this into the repository with the intent of
fixing it up. Instead, nothing happened.
Its appearance on rust-lang.org makes it seem semi-official, but it's
not. The rustfmt strike team will end up producing something like this
anyway, and leaving it around does nothing but mislead people.
