Update Box::from_raw example to generalize better
I know very little about rust, so I saw the example here
```
use std::alloc::{alloc, Layout};
unsafe {
let ptr = alloc(Layout:🆕:<i32>()) as *mut i32;
*ptr = 5;
let x = Box::from_raw(ptr);
}
```
and tried to generalize it by writing,
```
let layout = Layout:🆕:<T>();
let new_obj = unsafe {
let ptr = alloc(layout) as *mut T;
*ptr = obj;
Box::from_raw(ptr)
};
```
for some more complicated `T`, which ended up crashing with SIGSEGV,
because it tried to `drop_in_place` the previous object in `ptr` which is
of course garbage. I think that changing this example to use `.write` instead
would be a good idea to suggest the correct generalization. It is also more
consistent with other documentation items in this file, which use `.write`.
I also added a comment to explain it, but I'm not too attached to that,
and can see it being too verbose in this place.
Bring net/parser.rs up to modern up to date with modern rust patterns
The current implementation of IP address parsing is very unidiomatic; it's full of `if` / `return` / `is_some` / `is_none` instead of `?`, `loop` with manual index tracking; etc. Went through and did and cleanup to try to bring it in line with modern sensibilities.
The obvious concern with making changes like this is "make sure you understand why it's written that way before changing it". Looking through the commit history for this file, there are several much smaller commits that make similar changes (For instance, 3024c1434a, 4f3ab4986e, 79f876495b), and there don't seem to be any commits in the history that indicate that this lack of idiomaticity is related to specific performance needs (ie, there aren't any commits that replace a `for` loop with a `loop` and a manual index count). In fact, the basic shape of the file is essentially unchanged from its initial commit back in 2015.
Made the following changes throughout the IP address parser:
- Replaced all uses of `is_some()` / `is_none()` with `?`.
- "Upgraded" loops wherever possible; ie, replace `while` with `for`, etc.
- Removed all cases of manual index tracking / incrementing.
- Renamed several single-character variables with more expressive names.
- Replaced several manual control flow segments with equivalent adapters (such as `Option::filter`).
- Removed `read_seq_3`; replaced with simple sequences of `?`.
- Parser now reslices its state when consuming, rather than carrying a separate state and index variable.
- `read_digit` now uses `char::to_digit`.
- Added comments throughout, especially in the complex IPv6 parsing logic.
- Added comprehensive local unit tests for the parser to validate these changes.
Added detailed error code explanation for issue E0687 in Rust compiler.
Added proper error explanation for issue E0687 in the Rust compiler.
Error Code E0687
Sub Part of Issue #61137
r? @GuillaumeGomez
Revert "ci: allow gating gha on everything but macOS"
The macOS issue on GHA's side seems to be fixed, so this is not needed anymore.
r? @Mark-Simulacrum
Serialize all foreign `SourceFile`s into proc-macro crate metadata
Normally, we encode a `Span` that references a foreign `SourceFile` by
encoding information about the foreign crate. When we decode this
`Span`, we lookup the foreign crate in order to decode the `SourceFile`.
However, this approach does not work for proc-macro crates. When we load
a proc-macro crate, we do not deserialzie any of its dependencies (since
a proc-macro crate can only export proc-macros). This means that we
cannot serialize a reference to an upstream crate, since the associated
metadata will not be available when we try to deserialize it.
This commit modifies foreign span handling so that we treat all foreign
`SourceFile`s as local `SourceFile`s when serializing a proc-macro.
All `SourceFile`s will be stored into the metadata of a proc-macro
crate, allowing us to cotinue to deserialize a proc-macro crate without
needing to load any of its dependencies.
Since the number of foreign `SourceFile`s that we load during a
compilation session may be very large, we only serialize a `SourceFile`
if we have also serialized a `Span` which requires it.
Made the following changes throughout the IP address parser:
- Replaced all uses of `is_some()` / `is_none()` with `?`.
- "Upgraded" loops wherever possible; ie, replace `while` with `for`, etc.
- Removed all cases of manual index tracking / incrementing.
- Renamed several single-character variables with more expressive names.
- Replaced several manual control flow segments with equivalent adapters (such as `Option::filter`).
- Removed `read_seq_3`; replaced with simple sequences of `?`.
- Parser now reslices its state when consuming, rather than carrying a separate state and index variable.
- `read_digit` now uses `char::to_digit`.
- Removed unnecessary casts back and forth between u8 and u32
- Added comments throughout, especially in the complex IPv6 parsing logic.
- Added comprehensive local unit tests for the parser to validate these changes.
bootstrap: Configurable musl libdir
Make it possible to customize the location of musl libdir using
musl-libdir in config.toml, e.g., to use lib64 instead of lib.
[AVR] Update the rust-lang/llvm-project submodule to include AVR fixes recently merged
This PR updates rustc's LLVM submodule to include new AVR-specific
fixes recently merged on the Rust LLVM 'rustc/10.0-2020-05-05' branch.
All of these cherry-picked commits exist in upstream LLVM and were
cherry-picked into Rust's LLVM fork in commit 6c040dd86ed.
Relates to https://github.com/rust-lang/llvm-project/pull/66
```
|- 6c040dd86ed Merge pull request #66 from dylanmckay/avr-pick-upstream-llvm-fixes
|- 12dfdd3aed7 [AVR] Rewrite the function calling convention.
|- 118ac53f12b [AVR] Don't adjust for instruction size
|- bc27c282e13 [AVR] Fix miscompilation of zext + add
|- cfbe205a7e8 [AVR] Remove faulty stack pushing behavior
|- 143e1469e96 [AVR] Fix stack size in functions with a frame pointer
|- 6b2445d841e [LLVM][AVR] Support for R_AVR_6 fixup
|- 93ee4da19cf [AVR] Fix I/O instructions on XMEGA
|- 962c2415ffb [AVR] Do not place functions in .progmem.data
|- 65b8b170aef [AVR] Do not use divmod calls for bigger integers
|- 93a3b595d1c [AVR] Generalize the previous interrupt bugfix to signal
|- handlers too
|- cc4286349b4 [AVR] Respect the 'interrupt' function attribute
|- 954d0a92205 [AVR] Fix reads of uninitialized variables from constructor of AVRSubtarget
|- 1c0ddae73c9 [AVR] Fix read of uninitialized variable AVRSubtarget:::ELFArch
|- 0ed0823fe60 [AVR] Fix incorrect register state for LDRdPtr
|- 96075fc433d [AVR] Don't adjust addresses by 2 for absolute values
|- 6dfc55ba53b [AVR] Use correct register class for mul instructions
```
These changes include both correctness fixes and LLVM assertion error
fixes. Once all of these commits have been cherry-picked, all of the
LLVM plumbing for rust-lang/master to compile the AVR blink program will
be in place. Once this commit is merged, only PR rust-lang/rust#73270 will
be blocking successful compilation and emission of the AVR LED blink program.
The number of symbols we allocate (even early on) seems to be platform
dependent. We only care about hygiene for the purposes of this test,
so just set all of the symbol ids to zero
Normally, we encode a `Span` that references a foreign `SourceFile` by
encoding information about the foreign crate. When we decode this
`Span`, we lookup the foreign crate in order to decode the `SourceFile`.
However, this approach does not work for proc-macro crates. When we load
a proc-macro crate, we do not deserialzie any of its dependencies (since
a proc-macro crate can only export proc-macros). This means that we
cannot serialize a reference to an upstream crate, since the associated
metadata will not be available when we try to deserialize it.
This commit modifies foreign span handling so that we treat all foreign
`SourceFile`s as local `SourceFile`s when serializing a proc-macro.
All `SourceFile`s will be stored into the metadata of a proc-macro
crate, allowing us to cotinue to deserialize a proc-macro crate without
needing to load any of its dependencies.
Since the number of foreign `SourceFile`s that we load during a
compilation session may be very large, we only serialize a `SourceFile`
if we have also serialized a `Span` which requires it.
rustbuild: Move compiler-builtins build logic to manifest
This commit moves the compiler-builtins-specific build logic from
`src/bootstrap/bin/rustc.rs` into the workspace `Cargo.toml`'s
`[profile]` configuration. Now that rust-lang/cargo#7253 is fixed we can
ensure that Cargo knows about debug assertions settings, and it can also
be configured to specifically disable debug assertions unconditionally
for compiler-builtins. This should improve rebuild logic when
debug-assertions settings change and also improve build-std integration
where Cargo externally now has an avenue to learn how to build
compiler-builtins as well.
This commit moves the compiler-builtins-specific build logic from
`src/bootstrap/bin/rustc.rs` into the workspace `Cargo.toml`'s
`[profile]` configuration. Now that rust-lang/cargo#7253 is fixed we can
ensure that Cargo knows about debug assertions settings, and it can also
be configured to specifically disable debug assertions unconditionally
for compiler-builtins. This should improve rebuild logic when
debug-assertions settings change and also improve build-std integration
where Cargo externally now has an avenue to learn how to build
compiler-builtins as well.
stabilize leading_trailing_ones
This PR stabilizes the `leading_trailing_ones` feature. It's been available on nightly since the start of the year, and hasn't had any issues since. It seems unlikely we'll want to change this, so following up on @djc's suggestion in https://github.com/rust-lang/rust/issues/57969#issuecomment-638405264 I'd like to put forward this PR to stabilize the feature and make it part of `1.46.0`. Thanks!
cc/ @djc @rust-lang/libs
Stabilize `#![feature(const_if_match)]`
Quoting from the [stabilization report](https://github.com/rust-lang/rust/issues/49146#issuecomment-616301045):
> `if` and `match` expressions as well as the short-circuiting logic operators `&&` and `||` will become legal in all [const contexts](https://doc.rust-lang.org/reference/const_eval.html#const-context). A const context is any of the following:
>
> - The initializer of a `const`, `static`, `static mut` or enum discriminant.
> - The body of a `const fn`.
> - The value of a const generic (nightly only).
> - The length of an array type (`[u8; 3]`) or an array repeat expression (`[0u8; 3]`).
>
> Furthermore, the short-circuiting logic operators will no longer be lowered to their bitwise equivalents (`&` and `|` respectively) in `const` and `static` initializers (see #57175). As a result, `let` bindings can be used alongside short-circuiting logic in those initializers.
Resolves#49146.
Ideally, we would resolve 🐳#66753 before this lands on stable, so it might be worth pushing this back a release. Also, this means we should get the process started for #52000, otherwise people will have no recourse except recursion for iterative `const fn`.
r? @oli-obk
Rename clashing_extern_decl to clashing_extern_declarations.
Rename clashing_extern_decl to clashing_extern_declarations to bring in-line with lint naming conventions.
Fixes#73802.
r? @petrochenkov
Rename two `Resolver` traits
`trait Resolver` -> `trait ResolverExpand` for the resolver interface available from expansion.
`trait Resolver` -> `trait ResolverAstLowering` for the resolver interface available from AST lowering.
Addresses https://github.com/rust-lang/rust/pull/73587#discussion_r443242556
Forward Hash::write_iN to Hash::write_uN
The `Hasher::write_iN()` methods should forward to `Hasher::write_uN()`, because some Hasher implementations implement only the `write_uN()` variants, with the expectation that `write_iN()` will use the same implementation. Most notably, this is the case for the [FxHasher](5e09ea0a1c/src/lib.rs (L111)) used by rustc itself.
This used to be the case previously, but was broken in #59982. As the PR description makes no mention of this particular change, I assume it was unintentional.
In a local test, this mitigates the regression from #73526 on at least one test-case (cc @cuviper), because we're no longer at the mercy of `FxHasher::write()` getting inlined to get reasonable performance.
Make liveness more precise for assignments to fields
Previously, we were too conservative and `x.field = 4` was treated as a "use" of `x`. Now it neither kills `x` (since other fields of `x` may still be live) nor marks it as live.
cc @jonas-schievink, who ran into this problem.
Const prop: erase all block-only locals at the end of every block
I messed up this erasure in https://github.com/rust-lang/rust/pull/73656#discussion_r446040140. I think it is too fragile to have the previous scheme. Let's benchmark the new scheme and see what happens.
r? @wesleywiser
cc @felix91gr
Add partition_point
Add partition_point in C++.
Although existing binary_search in rust does not suitable when the slice has multiple hits,
this function returns exact point of partition.
The definition of this function is very clear and able to accept general matter, therefore you can easily get index which you want like lower/upper_bound.
https://github.com/rust-lang/rfcs/issues/2184
