test/c-variadic: Fix patterns on powerpc64
On architectures such as powerpc64 that use extend_integer_width_to in
their C ABI processing, integer parameters shorter than the native
register width will be annotated with the ArgAttribute::SExt or
ArgAttribute::ZExt attribute, and that attribute will be included in the
generated LLVM IR.
In this test, all relevant parameters are `i32`, which will get the
`signext` annotation on the relevant 64-bit architectures. Match both
the annotated and non-annotated case, but enforce that the annotation is
applied consistently.
Make `abs`, `wrapping_abs`, `overflowing_abs` const functions
This makes `abs`, `wrapping_abs` and `overflowing_abs` const functions like #58044 makes `wrapping_neg` and `overflowing_neg` const functions.
`abs` is made const by returning `(self ^ -1) - -1` = `!self + 1` = `-self` for negative numbers and `(self ^ 0) - 0` = `self` for non-negative numbers. The subexpression `self >> ($BITS - 1)` evaluates to `-1` for negative numbers and `0` otherwise. The subtraction overflows when `self` is `min_value()`, as we would be subtracting `max_value() - -1`; this is when `abs` should overflow.
`wrapping_abs` and `overflowing_abs` make use of `wrapping_sub` and `overflowing_sub` instead of the subtraction operator.
This commit changes the HIR lowering around `await` so that temporary
lifetimes are extended. Previously, await was lowered as:
```rust
{
let mut pinned = future;
loop {
match ::std::future::poll_with_tls_context(unsafe {
<::std::pin::Pin>::new_unchecked(&mut pinned)
}) {
::std::task::Poll::Ready(result) => break result,
::std::task::Poll::Pending => {}
}
yield ();
}
}
```
With this commit, await is lowered as:
```rust
match future {
mut pinned => loop {
match ::std::future::poll_with_tls_context(unsafe {
<::std::pin::Pin>::new_unchecked(&mut pinned)
}) {
::std::task::Poll::Ready(result) => break result,
::std::task::Poll::Pending => {}
}
yield ();
}
}
```
However, this change has the following side-effects:
- All temporaries in future will be considered to live across a
yield for the purpose of auto-traits.
- Borrowed temporaries in future are likely to be considered to be live
across the yield for the purpose of the generator transform.
Signed-off-by: David Wood <david@davidtw.co>
On architectures such as powerpc64 that use extend_integer_width_to in
their C ABI processing, integer parameters shorter than the native
register width will be annotated with the ArgAttribute::SExt or
ArgAttribute::ZExt attribute, and that attribute will be included in the
generated LLVM IR.
In this test, all relevant parameters are `i32`, which will get the
`signext` annotation on the relevant 64-bit architectures. Match both
the annotated and non-annotated case, but enforce that the annotation is
applied consistently.
Resolve attributes in several places
Resolve attributes for Arm, Field, FieldPat, GenericParam, Param, StructField and Variant.
This PR is based on @petrochenkov work located at 83fdb8d598.
Stabilize `bind_by_move_pattern_guards` in Rust 1.39.0
Closes https://github.com/rust-lang/rust/issues/15287.
After stabilizing `#![feature(bind_by_move_pattern_guards)]`, you can now use bind-by-move bindings in patterns and take references to those bindings in `if` guards of `match` expressions. For example, the following now becomes legal:
```rust
fn main() {
let array: Box<[u8; 4]> = Box::new([1, 2, 3, 4]);
match array {
nums
// ---- `nums` is bound by move.
if nums.iter().sum::<u8>() == 10
// ^------ `.iter()` implicitly takes a reference to `nums`.
=> {
drop(nums);
// --------- Legal as `nums` was bound by move and so we have ownership.
}
_ => unreachable!(),
}
}
```
r? @matthewjasper
compiletest: disable -Aunused for run-pass tests
Disabled the flag, but that led to quite a bit of fall out -- I think most of it is benign but I've not investigated thoroughly.
r? @petrochenkov
Reduce span to function name in unreachable calls
As title suggests, this might close#64103. Refer to the updated tests for expected output.
There is potential to further improve usability. In particular, is it favourable that the exact diverging expression/statement be pointed out (not only in this case, but for all unreachable code)? Certainly that would deserve another issue, but I'm interested in the opinions.
Rename test locals to work around LLDB bug
LLDB's expression parser can't unambiguously resolve local variables in
some cases, as described in #47938. Work around this by using names that
don't shadow direct submodules of `core`.
Closes#64050.
Bail out when encountering likely missing turbofish in parser
When encountering a likely intended turbofish without `::`, bubble
up the diagnostic instead of emitting it to allow the parser to recover
more gracefully and avoid uneccessary type errors that are likely to be
wrong.
Fix#61329.
rustc_codegen_llvm: give names to non-alloca variable values.
These names only matter when looking at LLVM IR, but they can help.
When one value is used for multiple variables, I decided to combine the names.
I chose `,` as a separator but maybe `=` or ` ` (space) are more appropriate.
(LLVM names can contain any characters - if necessary they end up having quotes)
As an example, this function:
```rust
#[no_mangle]
pub fn test(a: u32, b: u32) -> u32 {
let c = a + b;
let d = c;
let e = d * a;
e
}
```
Used to produce this LLVM IR:
```llvm
define i32 @test(i32 %a, i32 %b) unnamed_addr #0 {
start:
%0 = add i32 %a, %b
%1 = mul i32 %0, %a
ret i32 %1
}
```
But after this PR you get this:
```llvm
define i32 @test(i32 %a, i32 %b) unnamed_addr #0 {
start:
%"c,d" = add i32 %a, %b
%e = mul i32 %"c,d", %a
ret i32 %e
}
```
cc @nagisa @rkruppe
Use hygiene for AST passes
AST passes are now able to have resolve consider their expansions as if they were opaque macros defined either in some module in the current crate, or a fake empty module with `#[no_implicit_prelude]`.
* Add an ExpnKind for AST passes.
* Remove gensyms in AST passes.
* Remove gensyms in`#[test]`, `#[bench]` and `#[test_case]`.
* Allow opaque macros to define tests.
* Move tests for unit tests to their own directory.
* Remove `Ident::{gensym, is_gensymed}` - `Ident::gensym_if_underscore` still exists.
cc #60869, #61019
r? @petrochenkov
Rust 2018: NLL migrate mode => hard error
As per decision on a language team meeting as described in https://github.com/rust-lang/rust/pull/63565#issuecomment-528563744, we refuse to downgrade NLL errors, that AST borrowck accepts, into warnings and keep them as hard errors.
cc @rust-lang/lang
cc @rust-lang/wg-compiler-nll
or-patterns: Uniformly use `PatKind::Or` in AST & Fix/Cleanup resolve
Following up on work in https://github.com/rust-lang/rust/pull/63693 and https://github.com/rust-lang/rust/pull/61708, in this PR we:
- Uniformly use `PatKind::Or(...)` in AST:
- Change `ast::Arm.pats: Vec<P<Pat>>` => `ast::Arm.pat: P<Pat>`
- Change `ast::ExprKind::Let.0: Vec<P<Pat>>` => `ast::ExprKind::Let.0: P<Pat>`
- Adjust `librustc_resolve/late.rs` to correctly handle or-patterns at any level of nesting as a result.
In particular, the already-bound check which rejects e.g. `let (a, a);` now accounts for or-patterns. The consistency checking (ensures no missing bindings and binding mode consistency) also now accounts for or-patterns. In the process, a bug was found in the current compiler which allowed:
```rust
enum E<T> { A(T, T), B(T) }
use E::*;
fn foo() {
match A(0, 1) {
B(mut a) | A(mut a, mut a) => {}
}
}
```
The new algorithms took a few iterations to get right. I tried several clever schemes but ultimately a version based on a stack of hashsets and recording product/sum contexts was chosen since it is more clearly correct.
- Clean up `librustc_resolve/late.rs` by, among other things, using a new `with_rib` function to better ensure stack dicipline.
- Do not push the change in AST to HIR for now to avoid doing too much in this PR. To cope with this, we introduce a temporary hack in `rustc::hir::lowering` (clearly marked in the diff).
cc https://github.com/rust-lang/rust/issues/54883
cc @dlrobertson @matthewjasper
r? @petrochenkov
Improve searching in rustdoc and add tests
👋 I have made searching in rustdoc more intuitive, added a couple more tests and made a little shell script to aid testing. Closes#63005.
It took me quite a while to figure out how to run the tests for rustdoc (instead of running tests for other crates with rustdoc); the only pointer I found was [hidden in the rustc book](https://rust-lang.github.io/rustc-guide/rustdoc.html#cheat-sheet). Maybe this could be better documented? I shall be delighted to help if it is desirable.
When encountering a likely intended turbofish without `::`, bubble
up the diagnostic instead of emitting it to allow the parser to recover
more gracefully and avoid uneccessary type errors that are likely to be
wrong.
