Various local trait item iteration cleanups
Adding a trait impl for `Foo` unconditionally affected all queries that are interested in a completely independent trait `Bar`. Perf has no effect on this. We probably don't have a good perf test for this tho.
r? `@compiler-errors`
I am unsure about 9d05efb66f as it doesn't improve anything wrt incremental, because we still do all the checks for valid `Drop` impls, which subsequently will still invoke many queries and basically keep the depgraph the same.
I want to do
9549077a47/compiler/rustc_middle/src/ty/trait_def.rs (L141)
but would leave that to a follow-up PR, this one changes enough things as it is
remove `feature(inline_const_pat)`
Summarizing https://rust-lang.zulipchat.com/#narrow/channel/144729-t-types/topic/remove.20feature.28inline_const_pat.29.20and.20shared.20borrowck.
With https://github.com/rust-lang/types-team/issues/129 we will start to borrowck items together with their typeck parent. This is necessary to correctly support opaque types, blocking the new solver and TAIT/ATPIT stabilization with the old one. This means that we cannot really support `inline_const_pat` as they are implemented right now:
- we want to typeck inline consts together with their parent body to allow inference to flow both ways and to allow the const to refer to local regions of its parent.This means we also need to borrowck the inline const together with its parent as that's necessary to properly support opaque types
- we want the inline const pattern to participate in exhaustiveness checking
- to participate in exhaustiveness checking we need to evaluate it, which requires borrowck, which now relies on borrowck of the typeck root, which ends up checking exhaustiveness again. **This is a query cycle**.
There are 4 possible ways to handle this:
- stop typechecking inline const patterns together with their parent
- causes inline const patterns to be different than inline const exprs
- prevents bidirectional inference, we need to either fail to compile `if let const { 1 } = 1u32` or `if let const { 1u32 } = 1`
- region inference for inline consts will be harder, it feels non-trivial to support inline consts referencing local regions from the parent fn
- inline consts no longer participate in exhaustiveness checking. Treat them like `pat if pat == const { .. }` instead. We then only evaluate them after borrowck
- difference between `const { 1 }` and `const FOO: usize = 1; match x { FOO => () }`. This is confusing
- do they carry their weight if they are now just equivalent to using an if-guard
- delay exhaustiveness checking until after borrowck
- should be possible in theory, but is a quite involved change and may have some unexpected challenges
- remove this feature for now
I believe we should either delay exhaustiveness checking or remove the feature entirely. As moving exhaustiveness checking to after borrow checking is quite complex I think the right course of action is to fully remove the feature for now and to add it again once/if we've got that implementation figured out.
`const { .. }`-expressions remain stable. These seem to have been the main motivation for https://github.com/rust-lang/rfcs/issues/2920.
r? types
cc `@rust-lang/types` `@rust-lang/lang` #76001
Revert "Rollup merge of #136127 - WaffleLapkin:dyn_ptr_unwrap_cast, r=compiler-errors"
...not permanently tho. Just until we can land something like #138542, which will fix the underlying perf issues (https://github.com/rust-lang/rust/pull/136127#issuecomment-2743891744). I just don't want this to land on beta and have people rely on this behavior if it'll need some reworking for it to be implemented performantly.
r? `@WaffleLapkin` or reassign -- sorry for reverting ur pr! i'm working on getting it re-landed soon :>
hygiene: Rewrite `apply_mark_internal` to be more understandable
The previous implementation allocated new `SyntaxContext`s in the inverted order, and it was generally very hard to understand why its result matches what the `opaque` and `opaque_and_semitransparent` field docs promise.
```rust
/// This context, but with all transparent and semi-transparent expansions filtered away.
opaque: SyntaxContext,
/// This context, but with all transparent expansions filtered away.
opaque_and_semitransparent: SyntaxContext,
```
It also couldn't be easily reused for the case where the context id is pre-reserved like in #129827.
The new implementation tries to follow the docs in a more straightforward way.
I did the transformation in small steps, so it indeed matches the old implementation, not just the docs.
So I suggest reading only the new version.
Switch some rustc_on_unimplemented uses to diagnostic::on_unimplemented
The use on the SliceIndex impl appears unreachable, there is no mention of "vector indices" in any test output and I could not get it to show up in error messages.
Improve hir_pretty for struct expressions.
While working on https://github.com/rust-lang/rust/pull/139131 I noticed the hir pretty printer outputs an empty line between each field, and is also missing a space before the `{` and the `}`:
```rust
let a =
StructWithSomeFields{
field_1: 1,
field_2: 2,
field_3: 3,
field_4: 4,
field_5: 5,
field_6: 6,};
let a = StructWithSomeFields{ field_1: 1, field_2: 2, ..a};
```
This changes it to:
```rust
let a =
StructWithSomeFields {
field_1: 1,
field_2: 2,
field_3: 3,
field_4: 4,
field_5: 5,
field_6: 6 };
let a = StructWithSomeFields { field_1: 1, field_2: 2, ..a };
```
Remove attribute `#[rustc_error]`
It was an ancient way to write `check-pass` tests, but now it's no longer necessary (except for the `delayed_bug_from_inside_query` flavor, which is retained).
[AIX] Ignore linting on repr(C) structs with repr(packed) or repr(align(n))
This PR updates the lint added in 9b40bd7 to ignore repr(C) structs that also have repr(packed) or repr(align(n)).
As these representations can be modifiers on repr(C), it is assumed that users that add these should know what they are doing, and thus the the lint should not warn on the respective structs. For example, for the time being, using repr(packed) and manually padding a repr(C) struct can be done to correctly align struct members on AIX.
Set `target_vendor = "openwrt"` on `mips64-openwrt-linux-musl`
OpenWRT is a Linux distribution for embedded network devices. The target name contains `openwrt`, so we should set `cfg(target_vendor = "openwrt")`.
This is similar to what other Linux distributions do (the only one in-tree is `x86_64-unikraft-linux-musl`, but that sets `target_vendor = "unikraft"`).
Motivation: To make correctly [parsing target names](https://github.com/rust-lang/cc-rs/pull/1413) simpler.
Fixes https://github.com/rust-lang/rust/issues/131165.
CC target maintainer `@Itus-Shield`
Avoid wrapping constant allocations in packed structs when not necessary
This way LLVM will set the string merging flag if the alloc is a nul terminated string, reducing binary sizes.
try-job: armhf-gnu
hygiene: Ensure uniqueness of `SyntaxContextData`s
`SyntaxContextData`s are basically interned with `SyntaxContext`s working as indices, so they are supposed to be unique.
However, currently duplicate `SyntaxContextData`s can be created during decoding from metadata or incremental cache.
This PR fixes that.
cc https://github.com/rust-lang/rust/pull/129827#discussion_r1759074553
Remove InstanceKind::generates_cgu_internal_copy
This PR should not contain any behavior changes. Before this PR, the logic for selecting instantiation mode is spread across all of
* `instantiation_mode`
* `cross_crate_inlinable`
* `generates_cgu_internal_copy`
* `requires_inline`
The last two of those functions are not well-designed. The function that actually decides if we generate a CGU-internal copy is `instantiation_mode`, _not_ `generates_cgu_internal_copy`. The function `requires_inline` documents that it is about the LLVM `inline` attribute and that it is a hint. The LLVM attribute is called `inlinehint`, this function is also used by other codegen backends, and since it is part of instantiation mode selection it is *not* a hint.
The goal of this PR is to start cleaning up the logic into a sequence of checks that have a more logical flow and are easier to customize in the future (to do things like improve incrementality or improve optimizations without causing obscure linker errors because you forgot to update another part of the compiler).
Lower BinOp::Cmp to llvm.{s,u}cmp.* intrinsics
Lowers `mir::BinOp::Cmp` (`three_way_compare` intrinsic) to the corresponding LLVM `llvm.{s,u}cmp.i8.*` intrinsics.
These are the intrinsics mentioned in https://github.com/rust-lang/rust/pull/118310, which are now available in LLVM 19.
I couldn't find any follow-up PRs/discussions about this, please let me know if I missed something.
r? `@scottmcm`
Provide optional `Read`/`Write` methods for stdio
Override more of the default methods for `io::Read` and `io::Write` for stdio types, when efficient to do so, and deduplicate unsupported types.
Tracked in https://github.com/rust-lang/rust/issues/136756.
try-job: x86_64-msvc-1
Reduce FormattingOptions to 64 bits
This is part of https://github.com/rust-lang/rust/issues/99012
This reduces FormattingOptions from 6-7 machine words (384 bits on 64-bit platforms, 224 bits on 32-bit platforms) to just 64 bits (a single register on 64-bit platforms).
Before:
```rust
pub struct FormattingOptions {
flags: u32, // only 6 bits used
fill: char,
align: Option<Alignment>,
width: Option<usize>,
precision: Option<usize>,
}
```
After:
```rust
pub struct FormattingOptions {
/// Bits:
/// - 0-20: fill character (21 bits, a full `char`)
/// - 21: `+` flag
/// - 22: `-` flag
/// - 23: `#` flag
/// - 24: `0` flag
/// - 25: `x?` flag
/// - 26: `X?` flag
/// - 27: Width flag (if set, the width field below is used)
/// - 28: Precision flag (if set, the precision field below is used)
/// - 29-30: Alignment (0: Left, 1: Right, 2: Center, 3: Unknown)
/// - 31: Always set to 1
flags: u32,
/// Width if width flag above is set. Otherwise, always 0.
width: u16,
/// Precision if precision flag above is set. Otherwise, always 0.
precision: u16,
}
```
Avoid no-op unlink+link dances in incr comp
Incremental compilation scales quite poorly with the number of CGUs. This PR improves one reason for that.
The incr comp process hard-links all the files from an old session into a new one, then it runs the backend, which may just hard-link the new session files into the output directory. Then codegen hard-links all the output files back to the new session directory.
This PR (perhaps unimaginatively) fixes the silliness that ensues in the last step. The old `link_or_copy` implementation would be passed pairs of paths which are already the same inode, then it would blindly delete the destination and re-create the hard-link that it just deleted. This PR lets us skip both those operations. We don't skip the other two hard-links.
`cargo +stage1 b && touch crates/core/main.rs && strace -cfw -elink,linkat,unlink,unlinkat cargo +stage1 b` before and then after on `ripgrep-13.0.0`:
```
% time seconds usecs/call calls errors syscall
------ ----------- ----------- --------- --------- ----------------
52.56 0.024950 25 978 485 unlink
34.38 0.016318 22 727 linkat
13.06 0.006200 24 249 unlinkat
------ ----------- ----------- --------- --------- ----------------
100.00 0.047467 24 1954 485 total
```
```
% time seconds usecs/call calls errors syscall
------ ----------- ----------- --------- --------- ----------------
42.83 0.014521 57 252 unlink
38.41 0.013021 26 486 linkat
18.77 0.006362 25 249 unlinkat
------ ----------- ----------- --------- --------- ----------------
100.00 0.033904 34 987 total
```
This reduces the number of hard-links that are causing perf troubles, noted in https://github.com/rust-lang/rust/issues/64291 and https://github.com/rust-lang/rust/issues/137560
expand: Leave traces when expanding `cfg_attr` attributes
Currently `cfg_trace` just disappears during expansion, but after this PR `#[cfg_attr(some tokens)]` will leave a `#[cfg_attr_trace(some tokens)]` attribute instead of itself in AST after expansion (the new attribute is built-in and inert, its inner tokens are the same as in the original attribute).
This trace attribute can then be used by lints or other diagnostics, #133823 has some examples.
Tokens in these trace attributes are set to an empty token stream, so the traces are non-existent for proc macros and cannot affect any user-observable behavior.
This is also a weakness, because if a proc macro processes some code with the trace attributes, they will be lost, so the traces are best effort rather than precise.
The next step is to do the same thing with `cfg` attributes (`#[cfg(TRUE)]` currently remains in both AST and tokens after expanding, it should be replaced with a trace instead).
The idea belongs to `@estebank.`
Represent diagnostic side effects as dep nodes
This changes diagnostic to be tracked as a special dep node (`SideEffect`) instead of having a list of side effects associated with each dep node. `SideEffect` is always red and when forced, it emits the diagnostic and marks itself green. Each emitted diagnostic generates a new `SideEffect` with an unique dep node index.
Some implications of this:
- Diagnostic may now be emitted more than once as they can be emitted once when the `SideEffect` gets marked green and again if the task it depends on needs to be re-executed due to another node being red. It relies on deduplicating of diagnostics to avoid that.
- Anon tasks which emits diagnostics will no longer *incorrectly* be merged with other anon tasks.
- Reusing a CGU will now emit diagnostics from the task generating it.
uefi: fs: Implement exists
Also adds the initial file abstractions.
The file opening algorithm is inspired from UEFI shell. It starts by classifying if the Path is Shell mapping, text representation of device path protocol, or a relative path and converts into an absolute text representation of device path protocol.
After that, it queries all handles supporting
EFI_SIMPLE_FILE_SYSTEM_PROTOCOL and opens the volume that matches the device path protocol prefix (similar to Windows drive). After that, it opens the file in the volume using the remaining pat.
It also introduces OwnedDevicePath and BorrowedDevicePath abstractions to allow working with the base UEFI and Shell device paths efficiently.
DevicePath in UEFI behaves like an a group of nodes laied out in the memory contiguously and thus can be modeled using iterators.
This is an effort to break the original PR (https://github.com/rust-lang/rust/pull/129700) into much smaller chunks for faster upstreaming.
Rollup of 7 pull requests
Successful merges:
- #138384 (Move `hir::Item::ident` into `hir::ItemKind`.)
- #138508 (Clarify "owned data" in E0515.md)
- #138531 (Store test diffs in job summaries and improve analysis formatting)
- #138533 (Only use `DIST_TRY_BUILD` for try jobs that were not selected explicitly)
- #138556 (Fix ICE: attempted to remap an already remapped filename)
- #138608 (rustc_target: Add target feature constraints for LoongArch)
- #138619 (Flatten `if`s in `rustc_codegen_ssa`)
r? `@ghost`
`@rustbot` modify labels: rollup
Mangle rustc_std_internal_symbols functions
This reduces the risk of issues when using a staticlib or rust dylib compiled with a different rustc version in a rust program. Currently this will either (in the case of staticlib) cause a linker error due to duplicate symbol definitions, or (in the case of rust dylibs) cause rustc_std_internal_symbols functions to be silently overridden. As rust gets more commonly used inside the implementation of libraries consumed with a C interface (like Spidermonkey, Ruby YJIT (curently has to do partial linking of all rust code to hide all symbols not part of the C api), the Rusticl OpenCL implementation in mesa) this is becoming much more of an issue. With this PR the only symbols remaining with an unmangled name are rust_eh_personality (LLVM doesn't allow renaming it) and `__rust_no_alloc_shim_is_unstable`.
Helps mitigate https://github.com/rust-lang/rust/issues/104707
try-job: aarch64-gnu-debug
try-job: aarch64-apple
try-job: x86_64-apple-1
try-job: x86_64-mingw-1
try-job: i686-mingw-1
try-job: x86_64-msvc-1
try-job: i686-msvc-1
try-job: test-various
try-job: armhf-gnu
rustdoc-json: Don't also include `#[deprecated]` in `Item::attrs`
Closes#138378
Not sure if this should bump `FORMAT_VERSION` or not. CC `@Enselic` `@LukeMathWalker` `@obi1kenobi`
r? `@GuillaumeGomez,` best reviewed commit-by-commit
Install licenses into `share/doc/rust/licenses`
This changes the path from "licences" to "licenses" for consistency
across the repo, including the usage directly around this line. This is
a US/UK spelling difference, but I believe the US spelling is also more
common in open source in general.
Emit function declarations for functions with `#[linkage="extern_weak"]`
Currently, when declaring an extern weak function in Rust, we use the following syntax:
```rust
unsafe extern "C" {
#[linkage = "extern_weak"]
static FOO: Option<unsafe extern "C" fn() -> ()>;
}
```
This allows runtime-checking the extern weak symbol through the Option.
When emitting LLVM-IR, the Rust compiler currently emits this static as an i8, and a pointer that is initialized with the value of the global i8 and represents the nullabilty e.g.
```
`@FOO` = extern_weak global i8
`@_rust_extern_with_linkage_FOO` = internal global ptr `@FOO`
```
This approach does not work well with CFI, where we need to attach CFI metadata to a concrete function declaration, which was pointed out in https://github.com/rust-lang/rust/issues/115199.
This change switches to emitting a proper function declaration instead of a global i8. This allows CFI to work for extern_weak functions. Example:
```
`@_rust_extern_with_linkage_FOO` = internal global ptr `@FOO`
...
declare !type !61 !type !62 !type !63 !type !64 extern_weak void `@FOO(double)` unnamed_addr #6
```
We keep initializing the Rust internal symbol with the function declaration, which preserves the correct behavior for runtime checking the Option.
r? `@rcvalle`
cc `@jakos-sec`
try-job: test-various
mir_build: Avoid some useless work when visiting "primary" bindings
While looking over `visit_primary_bindings`, I noticed that it does a bunch of extra work to build up a collection of “user-type projections”, even though 2/3 of its call sites don't even use them. Those callers can get the same result via `thir::Pat::walk_always`.
(And it turns out that doing so also avoids creating some redundant user-type entries in MIR for some binding constructs.)
I also noticed that even when the user-type projections *are* used, the process of building them ends up eagerly cloning some nested vectors at every recursion step, even in cases where they won't be used because the current subpattern has no bindings. To avoid this, the visit method now assembles a linked list on the stack containing the information that *would* be needed to create projections, and only creates the concrete projections as needed when a primary binding is encountered.
Some relevant prior PRs:
- #55274
- 0bfe184b1a in #55937
---
There should be no user-visible change in compiler output.
Denote `ControlFlow` as `#[must_use]`
I've repeatedly hit bugs in the compiler due to `ControlFlow` not being marked `#[must_use]`. There seems to be an accepted ACP to make the type `#[must_use]` (https://github.com/rust-lang/libs-team/issues/444), so this PR implements that part of it.
Most of the usages in the compiler that trigger this new warning are "root" usages (calling into an API that uses control-flow internally, but for which the callee doesn't really care) and have been suppressed by `let _ = ...`, but I did legitimately find one instance of a missing `?` and one for a never-used `ControlFlow` value in #137448.
Presumably this needs an FCP too, so I'm opening this and nominating it for T-libs-api.
This PR also touches the tools (incl. rust-analyzer), but if this went into FCP, I'd split those out into separate PRs which can land before this one does.
r? libs-api
`@rustbot` label: T-libs-api I-libs-api-nominated
uefi: helpers: Add DevicePathNode abstractions
- UEFI device path is a series of nodes layed out in a contiguous memory region. So it makes sense to use Iterator abstraction for modeling DevicePaths
- This PR has been split off from #135368 for easier review. The allow dead_code will be removed in #135368
cc `@nicholasbishop`
Add a .bss-like scheme for encoded const allocs
This check if all bytes are zero feel like it should be too slow, and instead we should have a flag that we track, but that seems hard. Let's see how this perfs first.
Also we can probably stash the "it's all zero actually" flag inside one of the other struct members that's already not using an entire byte. This optimization doesn't fire all that often, so it's possible that by sticking it in the varint length field, this PR actually makes rmeta size worse.
Do not register `Self: AutoTrait` when confirming auto trait (in old solver)
Every built-in auto impl for a trait goal like `Ty: Auto` immediately registers another obligation of `Ty: Auto` as one of its nested obligations, leading to us stressing the cycle detection machinery a lot more than we need to. This is because all traits have a `Self: Trait` predicate.
To fix this, remove the call to `impl_or_trait_obligations` in `vtable_auto_impl`, since auto traits do not have where clauses.
r? lcnr
Calculate predecessor count directly
Avoid allocating a vector of small vectors merely to determine how many
predecessors each basic block has.
Additionally use u8 and saturating operations. The pass only needs to
distinguish between [0..1] and [2..].
Update bootstrap to edition 2024
The stage0 compiler now supports edition 2024, so we can update bootstrap to it. I manually reviewed all the changes from `cargo fix --edition` and reverted most of them (`if let` -> `matches` changes and two unneeded usages of `use <>`).
r? `@onur-ozkan`
try-job: dist-x86_64-msvc
strip `-Wlinker-messages` wrappers from `rust-lld` rmake test
The `tests/run-make/rust-lld` rmake test is failing locally on my M1, due to linker messages being in a different shape than the test expects: it asserts that the LLD version is the first linker message, which is seemingly not always the case on osx I guess.
```console
thread 'main' panicked at /Users/lqd/rust/lqd-rust/tests/run-make/rust-lld/rmake.rs:24:5:
the LLD version string should be present in the output logs:
warning: linker stderr: rust-lld: directory not found for option -L/usr/local/lib
LLD 20.1.0 (https://github.com/rust-lang/llvm-project.git 1c3bb96fdb6db7b8e8f24edb016099c223fdd27e)
Library search paths:
/Users/lqd/rust/lqd-rust/build/aarch64-apple-darwin/test/run-make/rust-lld/rmake_out
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/lib
Framework search paths:
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/System/Library/Frameworks
```
This PR normalizes away the `-Wlinker-messages` wrappers around the linker output, to remove the requirement that the linker version is the first linker message / is prefixed with the warning wrapper in the regex.
(also another strange thing to explain the pre-existing regex: it seems the LLD version is sometimes output on stderr sometimes on stdout cool stuff)
We could do this for the other lld rmake tests, but they're only enabled on x64 linux so less likely to have random linker messages appearing without anyone noticing.
Allow bounds checks when enumerating `IndexSlice` to be elided
Without this hint, each loop iteration has to separately bounds check the index. See https://godbolt.org/z/zrfPY4Ten for an example.
This is technically a behaviour change, but only in cases where the compiler is going to crash anyways.
Add `#[define_opaques]` attribute and require it for all type-alias-impl-trait sites that register a hidden type
Instead of relying on the signature of items to decide whether they are constraining an opaque type, the opaque types that the item constrains must be explicitly listed.
A previous version of this PR used an actual attribute, but had to keep the resolved `DefId`s in a side table.
Now we just lower to fields in the AST that have no surface syntax, instead a builtin attribute macro fills in those fields where applicable.
Note that for convenience referencing opaque types in associated types from associated methods on the same impl will not require an attribute. If that causes problems `#[defines()]` can be used to overwrite the default of searching for opaques in the signature.
One wart of this design is that closures and static items do not have generics. So since I stored the opaques in the generics of functions, consts and methods, I would need to add a custom field to closures and statics to track this information. During a T-types discussion we decided to just not do this for now.
fixes#131298
Speed up target feature computation
The LLVM backend calls `LLVMRustHasFeature` twice for every feature. In short-running rustc invocations, this accounts for a surprising amount of work.
r? `@bjorn3`
