When `Foo.field` or `Foo.method()` exprs are encountered, suggest `Foo::field` or `Foo::method()` when Foo is a type alias, not just
a struct, trait, or module.
Also rename test for this suggestion from issue-22692.rs to something more meaningful.
Pattern Migration 2024: fix incorrect messages/suggestions when errors arise in macro expansions
See the diff between the two commits for how this affected the error message and suggestion. In order to decide how to format those, the pattern migration diagnostic keeps track of which parts of the user's pattern cause problems in Edition 2024. However, it neglected to do some of this bookkeeping when pointing to macro expansion sites. This fixes that.
Do not ICE on default_field_value const with lifetimes
`#![feature(default_field_values)]` uses a `const` body that should be treated as inline `const`s, but is actually being detected otherwise. This is similar to the situation in #78174, so we take the same solution: we check if the const actually comes from a field, and if it does, we use that logic to get the appropriate lifetimes and not ICE during borrowck.
Fix#135649.
Unless `try_trait_v2` is enabled, don't mention that `FromResidual` isn't implemented for a specific type when the implicit `From` conversion of a `?` fails. For the end user on stable, `?` might as well be a compiler intrinsic, so we remove that note to avoid further confusion and allowing other parts of the error to be more prominent.
```
error[E0277]: `?` couldn't convert the error to `u8`
--> $DIR/bad-interconversion.rs:4:20
|
LL | fn result_to_result() -> Result<u64, u8> {
| --------------- expected `u8` because of this
LL | Ok(Err(123_i32)?)
| ------------^ the trait `From<i32>` is not implemented for `u8`
| |
| this can't be annotated with `?` because it has type `Result<_, i32>`
|
= note: the question mark operation (`?`) implicitly performs a conversion on the error value using the `From` trait
= help: the following other types implement trait `From<T>`:
`u8` implements `From<Char>`
`u8` implements `From<bool>`
```
improve cold_path()
#120370 added a new instrinsic `cold_path()` and used it to fix `likely` and `unlikely`
However, in order to limit scope, the information about cold code paths is only used in 2-target switch instructions. This is sufficient for `likely` and `unlikely`, but limits usefulness of `cold_path` for idiomatic rust. For example, code like this:
```
if let Some(x) = y { ... }
```
may generate 3-target switch:
```
switch y.discriminator:
0 => true branch
1 = > false branch
_ => unreachable
```
and therefore marking a branch as cold will have no effect.
This PR improves `cold_path()` to work with arbitrary switch instructions.
Note that for 2-target switches, we can use `llvm.expect`, but for multiple targets we need to manually emit branch weights. I checked Clang and it also emits weights in this situation. The Clang's weight calculation is more complex that this PR, which I believe is mainly because `switch` in `C/C++` can have multiple cases going to the same target.
Instead of `expand_statements`. This makes the code shorter and
consistent with other MIR transform passes.
The tests require updating because there is a slight change in
MIR output:
- the old code replaced the original statement with twelve new
statements.
- the new code inserts converts the original statement to a `nop` and
then insert twelve new statements in front of it.
I.e. we now end up with an extra `nop`, which doesn't matter at all.
Rollup of 7 pull requests
Successful merges:
- #137095 (Replace some u64 hashes with Hash64)
- #137100 (HIR analysis: Remove unnecessary abstraction over list of clauses)
- #137105 (Restrict DerefPure for Cow<T> impl to T = impl Clone, [impl Clone], str.)
- #137120 (Enable `relative-path-include-bytes-132203` rustdoc-ui test on Windows)
- #137125 (Re-add missing empty lines in the releases notes)
- #137145 (use add-core-stubs / minicore for a few more tests)
- #137149 (Remove SSE ABI from i586-pc-windows-msvc)
r? `@ghost`
`@rustbot` modify labels: rollup
use add-core-stubs / minicore for a few more tests
See https://github.com/rust-lang/rust/issues/131485 for context. These are some tests I worked on in the past so I figured I'd see if `minicore` works for them. :)
Enable `relative-path-include-bytes-132203` rustdoc-ui test on Windows
The problem with the error message on Windows is:
- The path separators are different
- The OS error message string is different
Normalizing those two things makes the test pass on Windows.
Replace some u64 hashes with Hash64
I introduced the Hash64 and Hash128 types in https://github.com/rust-lang/rust/pull/110083, essentially as a mechanism to prevent hashes from landing in our leb128 encoding paths. If you just have a u64 or u128 field in a struct then derive Encodable/Decodable, that number gets leb128 encoding. So if you need to store a hash or some other value which behaves very close to a hash, don't store it as a u64.
This reverts part of https://github.com/rust-lang/rust/pull/117603, which turned an encoded Hash64 into a u64.
Based on https://github.com/rust-lang/rust/pull/110083, I don't expect this to be perf-sensitive on its own, though I expect that it may help stabilize some of the small rmeta size fluctuations we currently see in perf reports.
Fix const items not being allowed to be called `r#move` or `r#static`
Because of an ambiguity with const closures, the parser needs to ensure that for a const item, the `const` keyword isn't followed by a `move` or `static` keyword, as that would indicate a const closure:
```rust
fn main() {
const move // ...
}
```
This check did not take raw identifiers into account, therefore being unable to distinguish between `const move` and `const r#move`. The latter is obviously not a const closure, so it should be allowed as a const item.
This fixes the check in the parser to only treat `const ...` as a const closure if it's followed by the *proper keyword*, and not a raw identifier.
Additionally, this adds a large test that tests for all raw identifiers in all kinds of positions, including `const`, to prevent issues like this one from occurring again.
fixes#137128
Overhaul `rustc_middle::limits`
In particular, to make `pattern_complexity` work more like other limits, which then enables some other simplifications.
r? ``@Nadrieril``
Start removing `rustc_middle::hir::map::Map`
`rustc_middle::hir::map::Map` is now just a low-value wrapper around `TyCtxt`. This PR starts removing it.
r? `@cjgillot`
The end goal is to eliminate `Map` altogether.
I added a `hir_` prefix to all of them, that seemed simplest. The
exceptions are `module_items` which became `hir_module_free_items` because
there was already a `hir_module_items`, and `items` which became
`hir_free_items` for consistency with `hir_module_free_items`.
Because of an ambiguity with const closures, the parser needs to ensure
that for a const item, the `const` keyword isn't followed by a `move` or
`static` keyword, as that would indicate a const closure:
```rust
fn main() {
const move // ...
}
```
This check did not take raw identifiers into account, therefore being
unable to distinguish between `const move` and `const r#move`. The
latter is obviously not a const closure, so it should be allowed as a
const item.
This fixes the check in the parser to only treat `const ...` as a const
closure if it's followed by the *proper keyword*, and not a raw
identifier.
Additionally, this adds a large test that tests for all raw identifiers in
all kinds of positions, including `const`, to prevent issues like this
one from occurring again.
Rework `name_regions` to not rely on reverse scc graph for non-member-constrain usages
Fixes https://github.com/rust-lang/rust/issues/137015
Splits the `name_regions` into two versions: One meant for member region constraint error reporting (which I've renamed to `name_regions_for_member_constraint`), and one meant *just* to replace region vids with an external region.
Use the latter in the usage sites I added in #136559, since the regions returned by `name_regions_for_member_constraint` are also not *totally* accurate (which is fine for how they're used for member region constraint error reporting -- they're intentionally returning overapproximated universal regions so that we have something to name in `+ use<'a>` suggestions, because opaques can only capture universal regions and since member region constraints don't insert any edges into the region graph, the error region is probably gonna be shorter than a universal region) and because that function requires the reverse scc graph to have been computed which isn't done for our usages in #136559.
rustdoc: improve refdef handling in the unresolved link lint
This commit takes advantage of a feature in pulldown-cmark that makes the list of link definitions available to the consuming application. It produces unresolved link warnings for refdefs that aren't used, and can now produce exact spans for the dest even when it has escapes.
Closes#133150 since this lint would have caught the mistake in that issue, and, along with https://github.com/rust-lang/rust-clippy/pull/13707, most mistakes in this class should produce a warning from one of them.
Export kernel descriptor for amdgpu kernels
The host runtime (HIP or HSA) expects a kernel descriptor object for each kernel in the ELF file. The amdgpu LLVM backend generates the object. It is created as a symbol with the name of the kernel plus a `.kd` suffix.
Add it to the exported symbols in the linker script, so that it can be found.
For reference, the symbol is created here in LLVM: d5457e4c16/llvm/lib/Target/AMDGPU/MCTargetDesc/AMDGPUTargetStreamer.cpp (L966)
I wrote [a test](6a9115b121) for this as well, I’ll add that once the target is merged and working.
With this, all PRs to get working code for amdgpu are open (this + the target + the two patches adding addrspacecasts for alloca and global variables).
Tracking issue: #135024
r? `@workingjubilee`
This commit takes advantage of a feature in pulldown-cmark that
makes the list of link definitions available to the consuming
application. It produces unresolved link warnings for refdefs
that aren't used, and can now produce exact spans for the dest
even when it has escapes.
Try to recover from path sep error in type parsing
Fixes#129273
Error using `:` in the argument list may mess up the parser.
case `tests/ui/suggestions/struct-field-type-including-single-colon` also changed, seems it's the same meaning, should be OK.
r? `@estebank`
Do not allow attributes on struct field rest patterns
Fixes#81282.
This removes support for attributes on struct field rest patterns (the `..` bit) from the parser. Previously any attributes were being parsed but dropped from the AST, so didn't work and were deleted by rustfmt.
This needs an equivalent change to the reference but I wanted to see how this PR is received first.
The error message it produces isn't great, however it does match the error you get if you try to add attributes to .. in struct expressions atm, although I can understand wanting to do better given this was previously accepted. I think I could move attribute parsing back up to where it was and then emit a specific new error for this case, however I might need some guidance as this is the first time I've messed around inside the compiler.
While this is technically breaking I don't think it's much of an issue: attributes in this position don't currently do anything and rustfmt outright deletes them, meaning it's incredibly unlikely to affect anyone. I have already made the equivalent change to *add* support for attributes (mostly) but the conversation in the linked issue suggested it would be more reasonable to just remove them (and pointed out it's much easier to add support later if we realise we need them).
Fix crate name validation
Reject macro calls inside attribute `#![crate_name]` like in `#![crate_name = concat!("na", "me")]`.
Prior to #117584, the result of the expansion (here: `"name"`) would actually be properly picked up by the compiler and used as the crate name. However since #117584 / on master, we extract the "value" (i.e., the *literal* string literal) of the `#![crate_name]` much earlier in the pipeline way before macro expansion and **skip**/**ignore** any `#![crate_name]`s "assigned to" a macro call. See also #122001.
T-lang has ruled to reject `#![crate_name = MACRO!(...)]` outright very similar to other built-in attributes whose value we need early like `#![crate_type]`. See accepted FCP: https://github.com/rust-lang/rust/issues/122001#issuecomment-2023203182.
Note that the check as implemented in this PR is even more "aggressive" compared to the one of `#![crate_type]` by running as early as possible in order to reject `#![crate_name = MACRO!(...)]` even in "non-normal" executions of `rustc`, namely on *print requests* (e.g., `--print=crate-name` and `--print=file-names`). If I were to move the validation step a bit further back close to the `#![crate_type]` one, `--print=crate-name` (etc.) would *not* exit fatally with an error in this kind of situation but happily report an incorrect crate name (i.e., the "crate name" as if `#![crate_name]` didn't exist / deduced from other sources like `--crate-name` or the file name) which would match the behavior on master. Again, see also #122001.
I'm mentioning this explicitly because I'm not sure if it was that clear in the FCP'ed issue. I argue that my current approach is the most reasonable one. I know (from reading the code and from past experiments) that various print requests are still quite broken (mostly lack of validation).
To the best of my knowledge, there's no print request whose output references/contains a crate *type*, so there's no "inherent need" to move `#![crate_type]`'s validation to happen earlier.
---
Fixes#122001.
https://github.com/rust-lang/rust/labels/relnotes: Compatibility. Breaking change.
Gets rid of two top-level UI tests which is always great.
Furthermore, move `need-crate-arg-ignore-tidy$x.rs`
from `command/` to `invalid-compile-flags/`.
`command/` concerns `std::process::Command` tests, not CLI tests.
llvm: Tolerate captures in tests
llvm/llvm-project@7e3735d1a1 introduces `captures` annotations. Adjust regexes to be tolerant of these.
`@rustbot` label:+llvm-main
add x86-sse2 (32bit) ABI that requires SSE2 target feature
This is the first commit of https://github.com/rust-lang/rust/pull/135408:
The primary goal of this is to make SSE2 required for our i686 targets (at least for the ones that use Pentium 4 as their baseline), to ensure they cannot be affected by https://github.com/rust-lang/rust/issues/114479. This has been MCPd in https://github.com/rust-lang/compiler-team/issues/808, and is tracked in https://github.com/rust-lang/rust/issues/133611.
We do this by defining a new ABI that these targets select, and making SSE2 required by the ABI (that's the first commit). That's kind of a hack, but it is the easiest way to make a target feature required via the target spec. In a follow-up change (https://github.com/rust-lang/rust/pull/135408), we can actually make use of SSE2 for the ABI, but that is running into some infrastructure issues.
r? `@workingjubilee`
try-job: aarch64-apple
try-job: aarch64-gnu
try-job: aarch64-gnu-debug
try-job: test-various
try-job: x86_64-gnu-nopt
try-job: dist-i586-gnu-i586-i686-musl
Normalize closure instance before eagerly monomorphizing it
We were monomorphizing two versions of the closure (or in the original issue, coroutine) -- one with normalized captures and one with unnormalized captures. This led to a symbol collision.
Fixes#137009
r? `@saethlin` or reassign
Rollup of 9 pull requests
Successful merges:
- #135778 (account for `c_enum_min_bits` in `multiple-reprs` UI test)
- #136052 (Correct comment for FreeBSD and DragonFly BSD in unix/thread)
- #136886 (Remove the common prelude module)
- #136956 (add vendor directory to .gitignore)
- #136958 (Fix presentation of purely "additive" replacement suggestion parts)
- #136967 (Use `slice::fill` in `io::Repeat` implementation)
- #136976 (alloc boxed: docs: use MaybeUninit::write instead of as_mut_ptr)
- #137007 (Emit MIR for each bit with on `dont_reset_cast_kind_without_updating_operand`)
- #137008 (Move code into `rustc_mir_transform`)
r? `@ghost`
`@rustbot` modify labels: rollup
Emit MIR for each bit with on `dont_reset_cast_kind_without_updating_operand`
PR #136450 introduced a diff that includes a pointer-sized alloc. This doesn't cause any problems on the compiler test suite but it affects the test suite that ferrocene has for `aarch64-unknown-none` as the snapshot of the diff only includes a 32-bit alloc even though this should be a 64-bit alloc on `aarch64-unknown-none`.
r? ``@compiler-errors``
Fix presentation of purely "additive" replacement suggestion parts
#127541 changes replacement suggestions to use the "diff" view always, which I think is really verbose in cases where a replacement snippet is a "superset" of the snippet that is being replaced.
Consider:
```
LL - Self::Baz: Clone,
LL + Self::Baz: Clone, T: std::clone::Clone
```
In this code, we suggest replacing `", "` with `", T: std::clone::Clone"`. This is a consequence of how the snippet is constructed. I believe that since the string that is being replaced is a subset of the replacement string, it's not providing much value to present this as a diff. Users should be able to clearly understand what's being suggested here using the `~` underline view we've been suggesting for some time now.
Given that this affects ~100 tests out of the ~1000 UI tests affected, I expect this to be a pretty meaningful improvement of the fallout of #127541.
---
In the last commit, this PR also "trims" replacement parts so that they are turned into their purely additive subset, if possible. See the diff for what this means.
---
r? estebank
Remove the common prelude module
This fixes the issues described in https://github.com/rust-lang/rust/issues/136102. Primarily, this resolves some issues with how the documentation for the prelude is generated:
- It avoids showing "unstable" for macros in the prelude that are actually stable.
- Avoids duplication of some pages due to the previous lack of `doc(no_inline)`.
- Makes the different edition preludes consistent, and sets a pattern that can be used by future editions.
We may need to rearrange these modules in the future if we decide to remove anything from the prelude again. If we do, I think we should look into a different solution that avoids the documentation problems.
Closes https://github.com/rust-lang/rust/issues/136102
Set both `nuw` and `nsw` in slice size calculation
There's an old note in the code to do this, and now that [LLVM-C has an API for it](f0b8ff1251/llvm/include/llvm-c/Core.h (L4403-L4408)), we might as well. And it's been there since what looks like LLVM 17 de9b6aa341 so doesn't even need to be conditional.
(There's other places, like `RawVecInner` or `Layout`, that might want to do things like this too, but I'll leave those for a future PR.)
Change description from compiletest to regression test
Co-authored-by: 许杰友 Jieyou Xu (Joe) <39484203+jieyouxu@users.noreply.github.com>
Improve test name, location, and description
Update tests/ui/impl-trait/impl-fn-rpit-opaque-107883.rs
Co-authored-by: waffle <waffle.lapkin@gmail.com>
`transmute` should also assume non-null pointers
Previously it only did integer-ABI things, but this way it does data pointers too. That gives more information in general to the backend, and allows slightly simplifying one of the helpers in slice iterators.
coverage: Eliminate more counters by giving them to unreachable nodes
When preparing a function's coverage counters and metadata during codegen, any part of the original coverage graph that was removed by MIR optimizations can be treated as having an execution count of zero.
Somewhat counter-intuitively, if we give those unreachable nodes a _higher_ priority for receiving physical counters (instead of counter expressions), that ends up reducing the total number of physical counters needed.
This works because if a node is unreachable, we don't actually create a physical counter for it. Instead that node gets a fixed zero counter, and any other node that would have relied on that physical counter in its counter expression can just ignore that term completely.
debuginfo: Set bitwidth appropriately in enum variant tags
Previously, we unconditionally set the bitwidth to 128-bits, the largest an enum would possibly be. Then, LLVM would cut down the constant by chopping off leading zeroes before emitting the DWARF. LLVM only supported 64-bit enumerators, so this would also have occasionally resulted in truncated data.
LLVM added support for 128-bit enumerators in llvm/llvm-project#125578
That patchset trusts the constant to describe how wide the variant tag is, so the high 64-bits of zeros are considered potentially load-bearing.
As a result, we went from emitting tags that looked like:
DW_AT_discr_value (0xfe)
(because `dwarf::BestForm` selected `data1`)
to emitting tags that looked like:
DW_AT_discr_value (<0x10> fe ff ff ff 00 00 00 00 00 00 00 00 00 00 00 00 )
This makes the `DW_AT_discr_value` encode at the bitwidth of the tag, which:
1. Is probably closer to our intentions in terms of describing the data.
2. Doesn't invoke the 128-bit support which may not be supported by all debuggers / downstream tools.
3. Will result in smaller debug information.
Rollup of 8 pull requests
Successful merges:
- #134999 (Add cygwin target.)
- #136559 (Resolve named regions when reporting type test failures in NLL)
- #136660 (Use a trait to enforce field validity for union fields + `unsafe` fields + `unsafe<>` binder types)
- #136858 (Parallel-compiler-related cleanup)
- #136881 (cg_llvm: Reduce visibility of all functions in the llvm module)
- #136888 (Always perform discr read for never pattern in EUV)
- #136948 (Split out the `extern_system_varargs` feature)
- #136949 (Fix import in bench for wasm)
r? `@ghost`
`@rustbot` modify labels: rollup
Split out the `extern_system_varargs` feature
After the stabilization PR was opened, `extern "system"` functions were added to `extended_varargs_abi_support`. This has a number of questions regarding it that were not discussed and were somewhat surprising. It deserves to be considered as its own feature, separate from `extended_varargs_abi_support`.
Tracking issue:
- https://github.com/rust-lang/rust/issues/136946
Always perform discr read for never pattern in EUV
Always perform a read of `!` discriminants to ensure that it's captured by closures in expr use visitor
Fixes#136852
r? Nadrieril or reassign
Use a trait to enforce field validity for union fields + `unsafe` fields + `unsafe<>` binder types
This PR introduces a new, internal-only trait called `BikeshedGuaranteedNoDrop`[^1] to faithfully model the field check that used to be implemented manually by `allowed_union_or_unsafe_field`.
942db6782f/compiler/rustc_hir_analysis/src/check/check.rs (L84-L115)
Copying over the doc comment from the trait:
```rust
/// Marker trait for the types that are allowed in union fields, unsafe fields,
/// and unsafe binder types.
///
/// Implemented for:
/// * `&T`, `&mut T` for all `T`,
/// * `ManuallyDrop<T>` for all `T`,
/// * tuples and arrays whose elements implement `BikeshedGuaranteedNoDrop`,
/// * or otherwise, all types that are `Copy`.
///
/// Notably, this doesn't include all trivially-destructible types for semver
/// reasons.
///
/// Bikeshed name for now.
```
As far as I am aware, there's no new behavior being guaranteed by this trait, since it operates the same as the manually implemented check. We could easily rip out this trait and go back to using the manually implemented check for union fields, however using a trait means that this code can be shared by WF for `unsafe<>` binders too. See the last commit.
The only diagnostic changes are that this now fires false-negatives for fields that are ill-formed. I don't consider that to be much of a problem though.
r? oli-obk
[^1]: Please let's not bikeshed this name lol. There's no good name for `ValidForUnsafeFieldsUnsafeBindersAndUnionFields`.
Resolve named regions when reporting type test failures in NLL
Just a improvement tweak to an error message that I broke out of a bigger PR that I had to close lol
Previously it only did integer-ABI things, but this way it does data pointers too. That gives more information in general to the backend, and allows slightly simplifying one of the helpers in slice iterators.
After the stabilization PR was opened, `extern "system"` functions were
added to `extended_varargs_abi_support`. This has a number of questions
regarding it that were not discussed and were somewhat surprising.
It deserves to be considered as its own feature, separate from
`extended_varargs_abi_support`.
When preparing a function's coverage counters and metadata during codegen, any
part of the original coverage graph that was removed by MIR optimizations can
be treated as having an execution count of zero.
Somewhat counter-intuitively, if we give those unreachable nodes a _higher_
priority for receiving physical counters (instead of counter expressions), that
ends up reducing the total number of physical counters needed.
This works because if a node is unreachable, we don't actually create a
physical counter for it. Instead that node gets a fixed zero counter, and any
other node that would have relied on that physical counter in its counter
expression can just ignore that term completely.
Correctly escape hashtags when running `invalid_rust_codeblocks` lint
Fixes#136899.
We forgot to use `map_line` when we wrote this lint.
r? ``@notriddle``
Mark condition/carry bit as clobbered in C-SKY inline assembly
C-SKY's compare and some arithmetic/logical instructions modify condition/carry bit (C) in PSR, but there is currently no way to mark it as clobbered in `asm!`.
This PR marks it as clobbered except when [`options(preserves_flags)`](https://doc.rust-lang.org/reference/inline-assembly.html#r-asm.options.supported-options.preserves_flags) is used.
Refs:
- Section 1.3 "Programming model" and Section 1.3.5 "Condition/carry bit" in CSKY Architecture user_guide:
9f7121f7d4/CSKY%20Architecture%20user_guide.pdf
> Under user mode, condition/carry bit (C) is located in the lowest bit of PSR, and it can be
accessed and changed by common user instructions. It is the only data bit that can be visited
under user mode in PSR.
> Condition or carry bit represents the result after one operation. Condition/carry bit can be
clearly set according to the results of compare instructions or unclearly set as some
high-precision arithmetic or logical instructions. In addition, special instructions such as
DEC[GT,LT,NE] and XTRB[0-3] will influence the value of condition/carry bit.
- Register definition in LLVM:
https://github.com/llvm/llvm-project/blob/llvmorg-19.1.0/llvm/lib/Target/CSKY/CSKYRegisterInfo.td#L88
cc ```@Dirreke``` ([target maintainer](aa6f5ab18e/src/doc/rustc/src/platform-support/csky-unknown-linux-gnuabiv2.md (target-maintainers)))
r? ```@Amanieu```
```@rustbot``` label +O-csky +A-inline-assembly
Reject `?Trait` bounds in various places where we unconditionally warned since 1.0
fixes#135730fixes#135809
Also a breaking change, so let's see what crater says.
This has been an unconditional warning since *before* 1.0
Cast allocas to default address space
Pointers for variables all need to be in the same address space for correct compilation. Therefore ensure that even if an `alloca` is created in a different address space, it is casted to the default address space before its value is used.
This is necessary for the amdgpu target and others where the default address space for `alloca`s is not 0.
For example the following code compiles incorrectly when not casting the address space to the default one:
```rust
fn f(p: *const i8 /* addrspace(0) */) -> *const i8 /* addrspace(0) */ {
let local = 0i8; /* addrspace(5) */
let res = if cond { p } else { &raw const local };
res
}
```
results in
```llvm
%local = alloca addrspace(5) i8
%res = alloca addrspace(5) ptr
if:
; Store 64-bit flat pointer
store ptr %p, ptr addrspace(5) %res
else:
; Store 32-bit scratch pointer
store ptr addrspace(5) %local, ptr addrspace(5) %res
ret:
; Load and return 64-bit flat pointer
%res.load = load ptr, ptr addrspace(5) %res
ret ptr %res.load
```
For amdgpu, `addrspace(0)` are 64-bit pointers, `addrspace(5)` are 32-bit pointers.
The above code may store a 32-bit pointer and read it back as a 64-bit pointer, which is obviously wrong and cannot work. Instead, we need to `addrspacecast %local to ptr addrspace(0)`, then we store and load the correct type.
Tracking issue: #135024
Stabilize target_feature_11
# Stabilization report
This is an updated version of https://github.com/rust-lang/rust/pull/116114, which is itself a redo of https://github.com/rust-lang/rust/pull/99767. Most of this commit and report were copied from those PRs. Thanks ```@LeSeulArtichaut``` and ```@calebzulawski!```
## Summary
Allows for safe functions to be marked with `#[target_feature]` attributes.
Functions marked with `#[target_feature]` are generally considered as unsafe functions: they are unsafe to call, cannot *generally* be assigned to safe function pointers, and don't implement the `Fn*` traits.
However, calling them from other `#[target_feature]` functions with a superset of features is safe.
```rust
// Demonstration function
#[target_feature(enable = "avx2")]
fn avx2() {}
fn foo() {
// Calling `avx2` here is unsafe, as we must ensure
// that AVX is available first.
unsafe {
avx2();
}
}
#[target_feature(enable = "avx2")]
fn bar() {
// Calling `avx2` here is safe.
avx2();
}
```
Moreover, once https://github.com/rust-lang/rust/pull/135504 is merged, they can be converted to safe function pointers in a context in which calling them is safe:
```rust
// Demonstration function
#[target_feature(enable = "avx2")]
fn avx2() {}
fn foo() -> fn() {
// Converting `avx2` to fn() is a compilation error here.
avx2
}
#[target_feature(enable = "avx2")]
fn bar() -> fn() {
// `avx2` coerces to fn() here
avx2
}
```
See the section "Closures" below for justification of this behaviour.
## Test cases
Tests for this feature can be found in [`tests/ui/target_feature/`](f6cb952dc1/tests/ui/target-feature).
## Edge cases
### Closures
* [target-feature 1.1: should closures inherit target-feature annotations? #73631](https://github.com/rust-lang/rust/issues/73631)
Closures defined inside functions marked with #[target_feature] inherit the target features of their parent function. They can still be assigned to safe function pointers and implement the appropriate `Fn*` traits.
```rust
#[target_feature(enable = "avx2")]
fn qux() {
let my_closure = || avx2(); // this call to `avx2` is safe
let f: fn() = my_closure;
}
```
This means that in order to call a function with #[target_feature], you must guarantee that the target-feature is available while the function, any closures defined inside it, as well as any safe function pointers obtained from target-feature functions inside it, execute.
This is usually ensured because target features are assumed to never disappear, and:
- on any unsafe call to a `#[target_feature]` function, presence of the target feature is guaranteed by the programmer through the safety requirements of the unsafe call.
- on any safe call, this is guaranteed recursively by the caller.
If you work in an environment where target features can be disabled, it is your responsibility to ensure that no code inside a target feature function (including inside a closure) runs after this (until the feature is enabled again).
**Note:** this has an effect on existing code, as nowadays closures do not inherit features from the enclosing function, and thus this strengthens a safety requirement. It was originally proposed in #73631 to solve this by adding a new type of UB: “taking a target feature away from your process after having run code that uses that target feature is UB” .
This was motivated by userspace code already assuming in a few places that CPU features never disappear from a program during execution (see i.e. 2e29bdf908/crates/std_detect/src/detect/arch/x86.rs); however, concerns were raised in the context of the Linux kernel; thus, we propose to relax that requirement to "causing the set of usable features to be reduced is unsafe; when doing so, the programmer is required to ensure that no closures or safe fn pointers that use removed features are still in scope".
* [Fix #[inline(always)] on closures with target feature 1.1 #111836](https://github.com/rust-lang/rust/pull/111836)
Closures accept `#[inline(always)]`, even within functions marked with `#[target_feature]`. Since these attributes conflict, `#[inline(always)]` wins out to maintain compatibility.
### ABI concerns
* [The extern "C" ABI of SIMD vector types depends on target features #116558](https://github.com/rust-lang/rust/issues/116558)
The ABI of some types can change when compiling a function with different target features. This could have introduced unsoundness with target_feature_11, but recent fixes (#133102, #132173) either make those situations invalid or make the ABI no longer dependent on features. Thus, those issues should no longer occur.
### Special functions
The `#[target_feature]` attribute is forbidden from a variety of special functions, such as main, current and future lang items (e.g. `#[start]`, `#[panic_handler]`), safe default trait implementations and safe trait methods.
This was not disallowed at the time of the first stabilization PR for target_features_11, and resulted in the following issues/PRs:
* [`#[target_feature]` is allowed on `main` #108645](https://github.com/rust-lang/rust/issues/108645)
* [`#[target_feature]` is allowed on default implementations #108646](https://github.com/rust-lang/rust/issues/108646)
* [#[target_feature] is allowed on #[panic_handler] with target_feature 1.1 #109411](https://github.com/rust-lang/rust/issues/109411)
* [Prevent using `#[target_feature]` on lang item functions #115910](https://github.com/rust-lang/rust/pull/115910)
## Documentation
* Reference: [Document the `target_feature_11` feature reference#1181](https://github.com/rust-lang/reference/pull/1181)
---
cc tracking issue https://github.com/rust-lang/rust/issues/69098
cc ```@workingjubilee```
cc ```@RalfJung```
r? ```@rust-lang/lang```
Rename rustc_middle::Ty::is_unsafe_ptr to is_raw_ptr
The wording unsafe pointer is less common and not mentioned in a lot of places, instead this is usually called a "raw pointer". For the sake of uniformity, we rename this method.
This came up during the review of
https://github.com/rust-lang/rust/pull/134424.
r? `@Noratrieb`
This continues two ongoing projects:
- Replacing ascii art with real icons that don't look like
syntax, are understandable to people who're familiar with
desktop computers and smart devices, and aren't ugly.
- Using labels and tooltips to clarify these icons, when the
limits of popular iconography hit us. In this case, I've added
tooltips, because, unfortunately, there's not room for
always-visible labels.
The host runtime (HIP or HSA) expects a kernel descriptor object for
each kernel in the ELF file. The amdgpu LLVM backend generates the
object. It is created as a symbol with the name of the kernel plus a
`.kd` suffix.
Add it to the exported symbols in the linker script, so that it can be
found.
compiler: give `ExternAbi` truly stable `Hash` and `Ord`
Currently, `ExternAbi` has a bunch of code to handle the reality that, as an enum, adding more variants to it will risk it hashing differently. It forces all of those variants to be added in a fixed order, except this means that the order of the variants doesn't correspond to any logical order except "historical accident". This is all to avoid having to rebless two tests. Perhaps there were more, once upon a time? But then we invented normalization in our test suite to handle exactly this sort of issue in a more general way.
There are two options here:
- Get rid of all the logical overhead and shrug, embracing blessing a couple of tests sometimes
- Change `ExternAbi` to have an ordering and hash that doesn't depend on the number of variants
As `ExternAbi` is essentially a strongly-typed string, and thus no two strings can be identical, this implements the second of the two by hand-implementing `Ord` and `Hash` to make the hashing and comparison based on the string! This will diff the current hashes, but they will diff no more after this.
tests: `-Copt-level=3` instead of `-O` in codegen tests
An effective blocker for redefining the meaning of `-O` is to stop reusing this somewhat ambiguous alias in our own codegen test suite. The choice between `-Copt-level=2` and `-Copt-level=3` is arbitrary for most of our tests. In most cases it makes no difference, so I set most of them to `-Copt-level=3`, as it will lead to slightly more "normalized" codegen.
try-job: test-various
try-job: arm-android
try-job: armhf-gnu
try-job: i686-gnu-1
try-job: i686-gnu-2
try-job: i686-mingw
try-job: i686-msvc-1
try-job: i686-msvc-2
try-job: aarch64-apple
try-job: aarch64-gnu
tests: `-Copt-level=3` instead of `-O` in assembly tests
An effective blocker for redefining the meaning of `-O` is to stop reusing this somewhat ambiguous alias in our own assembly test suite. The choice between `-Copt-level=2` and `-Copt-level=3` is arbitrary for most of our tests. In most cases it makes no difference, so I set most of them to `-Copt-level=3`, as it will lead to slightly more "normalized" assembly.
Previously, we unconditionally set the bitwidth to 128-bits, the largest
an discrimnator would possibly be. Then, LLVM would cut down the constant by
chopping off leading zeroes before emitting the DWARF. LLVM only
supported 64-bit descriminators, so this would also have occasionally
resulted in truncated data (or an assert) if more than 64-bits were
used.
LLVM added support for 128-bit enumerators in llvm/llvm-project#125578
That patchset also trusts the constant to describe how wide the variant tag is.
As a result, we went from emitting tags that looked like:
DW_AT_discr_value (0xfe)
(`form1`)
to emitting tags that looked like:
DW_AT_discr_value (<0x10> fe ff ff ff 00 00 00 00 00 00 00 00 00 00 00 00 )
This makes the `DW_AT_discr_value` encode at the bitwidth of the tag,
which:
1. Is probably closer to our intentions in terms of describing the data.
2. Doesn't invoke the 128-bit support which may not be supported by all
debuggers / downstream tools.
3. Will result in smaller debug information.
Rollup of 8 pull requests
Successful merges:
- #134981 ( Explain that in paths generics can't be set on both the enum and the variant)
- #136698 (Replace i686-unknown-redox target with i586-unknown-redox)
- #136767 (improve host/cross target checking)
- #136829 ([rustdoc] Move line numbers into the `<code>` directly)
- #136875 (Rustc dev guide subtree update)
- #136900 (compiler: replace `ExternAbi::name` calls with formatters)
- #136913 (Put kobzol back on review rotation)
- #136915 (documentation fix: `f16` and `f128` are not double-precision)
r? `@ghost`
`@rustbot` modify labels: rollup
compiler: replace `ExternAbi::name` calls with formatters
Most of these just format the ABI string, so... just format ExternAbi? This makes it more consistent and less jank when we can do it.
[rustdoc] Move line numbers into the `<code>` directly
Fixes#84242.
This is the first for adding support for https://github.com/rust-lang/rust/issues/127334 and also for another feature I'm working on.
A side-effect of this change is that it also fixes source code pages display in lynx since they're not directly in the source code.
To allow having code wrapping, the grid approach doesn't work as the line numbers are in their own container, so we need to move them into the code. Now with this, it becomes much simpler to do what we want (with CSS mostly). One downside: the highlighting became more complex and slow as we need to generate some extra HTML tags directly into the highlighting process. However that also allows to not have a huge HTML size increase.
You can test the result [here](https://rustdoc.crud.net/imperio/move-line-numbers-into-code/scrape_examples/fn.test_many.html) and [here](https://rustdoc.crud.net/imperio/move-line-numbers-into-code/src/scrape_examples/lib.rs.html#10).
The appearance should have close to no changes.
r? ``@notriddle``
Explain that in paths generics can't be set on both the enum and the variant
```
error[E0109]: type arguments are not allowed on tuple variant `TSVariant`
--> $DIR/enum-variant-generic-args.rs:54:29
|
LL | Enum::<()>::TSVariant::<()>(());
| --------- ^^ type argument not allowed
| |
| not allowed on tuple variant `TSVariant`
|
= note: generic arguments are not allowed on both an enum and its variant's path segments simultaneously; they are only valid in one place or the other
help: remove the generics arguments from one of the path segments
|
LL - Enum::<()>::TSVariant::<()>(());
LL + Enum::TSVariant::<()>(());
|
LL - Enum::<()>::TSVariant::<()>(());
LL + Enum::<()>::TSVariant(());
|
```
Fix#93993.
Rollup of 8 pull requests
Successful merges:
- #135549 (Document some safety constraints and use more safe wrappers)
- #135965 (In "specify type" suggestion, skip type params that are already known)
- #136193 (Implement pattern type ffi checks)
- #136646 (Add a TyPat in the AST to reuse the generic arg lowering logic)
- #136874 (Change the issue number for `likely_unlikely` and `cold_path`)
- #136884 (Lower fn items as ZST valtrees and delay a bug)
- #136885 (i686-linux-android: increase CPU baseline to Pentium 4 (without an actual change)
- #136891 (Check sig for errors before checking for unconstrained anonymous lifetime)
r? `@ghost`
`@rustbot` modify labels: rollup
Lower fn items as ZST valtrees and delay a bug
Lower it as a ZST instead of a const error, which we can handle mostly fine. Delay a bug so we don't accidentally support it tho.
r? BoxyUwU
Fixes#136855Fixes#136853Fixes#136854Fixes#136337
Only added one test bc that's really the crux of the issue (fn item in array length position).
Add a TyPat in the AST to reuse the generic arg lowering logic
This simplifies ast lowering significantly with little cost to the pattern types parser.
Also fixes any problems we've had with generic args (well, pushes any problems onto the `generic_const_exprs` feature gate)
follow-up to https://github.com/rust-lang/rust/pull/136284#discussion_r1939292367
r? ``@BoxyUwU``
Implement pattern type ffi checks
Previously we just rejected pattern types outright in FFI, but that was never meant to be a permanent situation. We'll need them supported to use them as the building block for `NonZero` and `NonNull` after all (both of which are FFI safe).
best reviewed commit by commit.
In "specify type" suggestion, skip type params that are already known
When we suggest specifying a type for an expression or pattern, like in a `let` binding, we previously would print the entire type as the type system knew it. We now look at the params that have *no* inference variables, so they are fully known to the type system which means that they don't need to be specified.
This helps in suggestions for types that are really long, because we can usually skip most of the type params and make the annotation as short as possible:
```
error[E0282]: type annotations needed for `Result<_, ((..., ..., ..., ...), ..., ..., ...)>`
--> $DIR/really-long-type-in-let-binding-without-sufficient-type-info.rs:7:9
|
LL | let y = Err(x);
| ^ ------ type must be known at this point
|
help: consider giving `y` an explicit type, where the type for type parameter `T` is specified
|
LL | let y: Result<T, _> = Err(x);
| ++++++++++++++
```
Fix#135919.
Directly map each ExternAbi variant to its string and back again.
This has a few advantages:
- By making the ABIs compare equal to their strings, we can easily
lexicographically sort them and use that sorted slice at runtime.
- We no longer need a workaround to make sure the hashes remain stable,
as they already naturally are (by being the hashes of unique strings).
- The compiler can carry around less &str wide pointers
Properly deeply normalize in the next solver
Turn deep normalization into a `TypeOp`. In the old solver, just dispatch to the `Normalize` type op, but in the new solver call `deeply_normalize`. I chose to separate it into a different type op b/c some normalization is a no-op in the new solver, so this distinguishes just the normalization we need for correctness.
Then use `DeeplyNormalize` in the callsites we used to be using a `CustomTypeOp` (for normalizing known type outlives obligations), and also use it to normalize function args and impl headers in the new solver.
Finally, use it to normalize signatures for WF checks in the new solver as well. This addresses https://github.com/rust-lang/trait-system-refactor-initiative/issues/146.
```
error[E0109]: type arguments are not allowed on tuple variant `TSVariant`
--> $DIR/enum-variant-generic-args.rs:54:29
|
LL | Enum::<()>::TSVariant::<()>(());
| --------- ^^ type argument not allowed
| |
| not allowed on tuple variant `TSVariant`
|
= note: generic arguments are not allowed on both an enum and its variant's path segments simultaneously; they are only valid in one place or the other
help: remove the generics arguments from one of the path segments
|
LL - Enum::<()>::TSVariant::<()>(());
LL + Enum::<()>::TSVariant(());
|
```
```
error[E0109]: type arguments are not allowed on enum `Enum` and tuple variant `TSVariant`
--> $DIR/enum-variant-generic-args.rs:54:12
|
LL | Enum::<()>::TSVariant::<()>(());
| ---- ^^ --------- ^^ type argument not allowed
| | |
| | not allowed on tuple variant `TSVariant`
| not allowed on enum `Enum`
|
= note: generic arguments are not allowed on both an enum and its variant's path segments simultaneously; they are only valid in one place or the other
help: remove the generics arguments from one of the path segments
|
LL - Enum::<()>::TSVariant::<()>(());
LL + Enum::<()>::TSVariant(());
|
```
Fix#93993.
This should guarantee it tests what we want it to test and no more.
It should probably also run on 64-bit platforms that are not x86-64,
which will often have the vector registers the opt implies.
This fixes the issues described in
https://github.com/rust-lang/rust/issues/136102. Primarily, this
resolves some issues with how the documentation for the prelude is
generated:
- It avoids showing "unstable" for macros in the prelude that are
actually stable.
- Avoids duplication of some pages due to the previous lack of
`doc(no_inline)`.
- Makes the different edition preludes consistent, and sets a pattern
that can be used by future editions.
We may need to rearrange these modules in the future if we decide to
remove anything from the prelude again. If we do, I think we should look
into a different solution that avoids the documentation problems.
show supported register classes in error message
a simple diagnostic change that shows the supported register classes when an invalid one is found.
This information can be hard to find (especially for unstable targets), and this message now gives at least something to try or search for. I've followed the pattern for invalid clobber ABIs.
`@rustbot` label +A-inline-assembly
fix ensure_monomorphic_enough
When polymorphization was still a thing, the visitor was used to only recurse into *used generic parameters* of function/closure/coroutine types and allow unused parameters (i.e. the polymorphized parameters) to remain generic.
When polymorphization got removed, this got changed to always treat all parameters as polymorphic and never recurse into them: https://github.com/rust-lang/rust/pull/133883/files#diff-210c59e321070d0ca4625c04e9fb064bf43ddc34082e7e33a7ee8a6c577e95afL44-L62
This is clearly wrong and can cause MIR opts to misbehave, for example this currently prints "false" in release mode:
```rust
#![feature(core_intrinsics)]
fn generic<T>() {}
const fn type_id_of_val<T: 'static>(_: &T) -> u128 {
std::intrinsics::type_id::<T>()
}
fn cursed_is_i32<T: 'static>() -> bool {
(const { type_id_of_val(&generic::<T>) } == const { type_id_of_val(&generic::<i32>) })
}
fn main() {
dbg!(cursed_is_i32::<i32>());
}
```
This PR reverts to the old behavior of always treating all types that contain type parameters as too generic, like we used to do without `-Zpolymorphize` before.
~~I'm not including the above as a test case here, because I think there is little value in testing code paths that have been removed and this seems unlikely to regress in a way that would be caught by a regression test, but let me know if you disagree and want me to add a test anyway.~~
Overhaul how contracts are lowered on fn-like bodies
Consolidates all of the contracts lowering logic into `lower_fn_body`, rather than having it be split between `lower_item_kind` and `lower_fn_body`. This should fix#136683.
r? celinval
Stop using span hack for contracts feature gating
The contracts machinery is a pretty straightforward case of an *external* feature using a (perma-unstable) *internal* feature within its implementation. There's no reason why it needs to be implemented any differently than other features by using global span tracking hacks to change whether the internals are gated behind the `contracts` or `contracts_internals` feature gate -- for the case of macro expansions we already have `allow_internal_unstable` for exactly this situation.
This PR changes the internal, perma-unstable AST syntax to use the `contracts_internals` gate always, and adjusts the macro expansion to use the right spans so that `allow_internal_unstable` works correctly.
As a follow-up, there's really no reason to have `contracts` be a *compiler feature* since it's at this point fully a *library feature*; the only reason it's a compiler feature today is so we can mark it as incomplete, but that seems like a weak reason. I didn't do anything in this PR for this.
r? ``@celinval``
Show diff suggestion format on verbose replacement
```
error[E0610]: `{integer}` is a primitive type and therefore doesn't have fields
--> $DIR/attempted-access-non-fatal.rs:7:15
|
LL | let _ = 2.l;
| ^
|
help: if intended to be a floating point literal, consider adding a `0` after the period and a `f64` suffix
|
LL - let _ = 2.l;
LL + let _ = 2.0f64;
|
```
before:
```
error[E0610]: `{integer}` is a primitive type and therefore doesn't have fields
--> $DIR/attempted-access-non-fatal.rs:7:15
|
LL | let _ = 2.l;
| ^
|
help: if intended to be a floating point literal, consider adding a `0` after the period and a `f64` suffix
|
LL + let _ = 2.0f64;
| ~~~~
```
r? `@oli-obk`
compiler: gate `extern "{abi}"` in ast_lowering
I don't believe low-level crates like `rustc_abi` should have to know or care about higher-level concerns like whether the ABI string is stable for users. These implementation details can be made less open to public inspection. This way the code that governs stability is near the code that enforces stability, and compiled together.
It also abstracts away certain error messages instead of constantly repeating them.
A few error messages are simply deleted outright, instead of made uniform, because they are either too dated to be useful or redundant with other diagnostic improvements we could make. These can be pursued in followups: my first concern was making sure there wasn't unnecessary diagnostics-related code in `rustc_abi`, which is not well-positioned to understand what kind of errors are going to be generated based on how it is used.
r? ``@ghost``
Prevent generic pattern types from being used in libstd
Pattern types should follow the same rules that patterns follow. So a pattern type range must not wrap and not be empty. While we reject such invalid ranges at layout computation time, that only happens during monomorphization in the case of const generics. This is the exact same issue as other const generic math has, and since there's no solution there yet, I put these pattern types behind a separate incomplete feature.
These are not necessary for the pattern types MVP (replacing the layout range attributes in libcore and rustc).
cc #136574 (new tracking issue for the `generic_pattern_types` feature gate)
r? ``@lcnr``
cc ``@scottmcm`` ``@joshtriplett``
Delay bug when method confirmation cannot upcast object pick of self
Justification is on the test comment. Simply delays a bug that we were previously ICEing on.
cc ``@adetaylor`` since this is a `arbitrary_self_types` ICE.
Introduce CoercePointeeWellformed for coherence checks at typeck stage
Fix#135206
This is the first PR to introduce the "wellformedness" check for `derive(CoercePointee)`.
This patch introduces a new error code to cover all the prerequisites of the said macro. The checks that is enforced with this patch is whether the data is indeed `struct` and whether the layout is set to `repr(transparent)`.
A following series of patch will arrive later to address the following concern.
1. #135217 so that we would only admit one single coercion on one type parameter, and leave the rest for future consideration in tandem of development of other coercion rules.
1. Enforcement of data field requirements.
**An open question** is whether there is a good schema to encode the `#[pointee]` as well, so that we could also check if the `#[pointee]` type parameter is indeed `?Sized`.
``@rustbot`` label F-derive_coerce_pointee
Pointers for variables all need to be in the same address space for
correct compilation. Therefore ensure that even if an `alloca` is
created in a different address space, it is casted to the default
address space before its value is used.
This is necessary for the amdgpu target and others where the default
address space for `alloca`s is not 0.
For example the following code compiles incorrectly when not casting the
address space to the default one:
```rust
fn f(p: *const i8 /* addrspace(0) */) -> *const i8 /* addrspace(0) */ {
let local = 0i8; /* addrspace(5) */
let res = if cond { p } else { &raw const local };
res
}
```
results in
```llvm
%local = alloca addrspace(5) i8
%res = alloca addrspace(5) ptr
if:
; Store 64-bit flat pointer
store ptr %p, ptr addrspace(5) %res
else:
; Store 32-bit scratch pointer
store ptr addrspace(5) %local, ptr addrspace(5) %res
ret:
; Load and return 64-bit flat pointer
%res.load = load ptr, ptr addrspace(5) %res
ret ptr %res.load
```
For amdgpu, `addrspace(0)` are 64-bit pointers, `addrspace(5)` are
32-bit pointers.
The above code may store a 32-bit pointer and read it back as a 64-bit
pointer, which is obviously wrong and cannot work. Instead, we need to
`addrspacecast %local to ptr addrspace(0)`, then we store and load the
correct type.
```
error[E0610]: `{integer}` is a primitive type and therefore doesn't have fields
--> $DIR/attempted-access-non-fatal.rs:7:15
|
LL | let _ = 2.l;
| ^
|
help: if intended to be a floating point literal, consider adding a `0` after the period and a `f64` suffix
|
LL - let _ = 2.l;
LL + let _ = 2.0f64;
|
```
adding autodiff tests
I'd like to get started with upstreaming some tests, even though I'm still waiting for an answer on how to best integrate the enzyme pass. Can we therefore temporarily support the -Z llvm-plugins here without too much effort? And in that case, how would that work? I saw you can do remapping, e.g. `rust-src-base`, but I don't think that will give me the path to libEnzyme.so. Do you have another suggestion?
Other than that this test simply checks that the derivative of `x*x` is `2.0 * x`, which in this case is computed as
`%0 = fadd fast double %x.0.val, %x.0.val`
(I'll add a few more tests and move it to an autodiff folder if we can use the -Z flag)
r? ``@jieyouxu``
Locally at least `-Zllvm-plugins=${PWD}/build/x86_64-unknown-linux-gnu/enzyme/build/Enzyme/libEnzyme-19.so` seems to work if I copy the command I get from x.py test and run it manually. However, running x.py test itself fails.
Tracking:
- https://github.com/rust-lang/rust/issues/124509
Zulip discussion: https://rust-lang.zulipchat.com/#narrow/channel/326414-t-infra.2Fbootstrap/topic/Enzyme.20build.20changes
coverage: Defer part of counter-creation until codegen
Follow-up to #135481 and #135873.
One of the pleasant properties of the new counter-assignment algorithm is that we can stop partway through the process, store the intermediate state in MIR, and then resume the rest of the algorithm during codegen. This lets it take into account which parts of the control-flow graph were eliminated by MIR opts, resulting in fewer physical counters and simpler counter expressions.
Those improvements end up completely obsoleting much larger chunks of code that were previously responsible for cleaning up the coverage metadata after MIR opts, while also doing a more thorough cleanup job.
(That change also unlocks some further simplifications that I've kept out of this PR to limit its scope.)
Add amdgpu target
Add amdgpu target to rustc and enable the LLVM target.
Fix compiling `core` with the amdgpu:
The amdgpu backend makes heavy use of different address spaces. This
leads to situations, where a pointer in one addrspace needs to be casted
to a pointer in a different addrspace. `bitcast` is invalid for this
case, `addrspacecast` needs to be used.
Fix compilation failures that created bitcasts for such cases by
creating pointer casts (which creates an `addrspacecast` under the hood)
instead.
MCP: https://github.com/rust-lang/compiler-team/issues/823
Tracking issue: #135024
Kinda related to the original amdgpu tracking issue #51575 (though that one has been closed for a while).
These are either residue of a long-term migration away from something,
or are simply trying too hard to be specifically useful:
nearest-match suggestions for ABI strings should handle this.
By moving this stability check into AST lowering, we effectively make
it impossible to accidentally miss, as it must happen to generate HIR.
Also, we put the ABI-stability code next to code that actually uses it!
This allows code that wants to reason about backend ABI implementations
to stop worrying about high-level concerns like syntax stability,
while still leaving it as the authority on what ABIs actually exist.
It also makes it easy to refactor things to have more consistent errors.
For now, we only apply this to generalize the existing messages a bit.
DWARF 1 is very different than DWARF 2+ (see the commentary in
https://gcc.gnu.org/onlinedocs/gcc/Debugging-Options.html#index-gdwarf)
and LLVM does not really seem to support DWARF 1 as Clang does not offer
a `-gdwarf-1` flag and `llc` will just generate DWARF 2 with the version
set to 1: https://godbolt.org/z/s85d87n3a.
Since this isn't actually supported (and it's not clear it would be
useful anyway), report that DWARF 1 is not supported if it is requested.
Also add a help message to the error saying which versions are supported.
Update bootstrap compiler and rustfmt
The rustfmt version we previously used formats things differently from what the latest nightly rustfmt does. This causes issues for subtrees that get formatted both in-tree and in their own repo. Updating the rustfmt used in-tree solves those issues. Also bumped the bootstrap compiler as the stage0 update command always updates both at the same
time.
Rollup of 5 pull requests
Successful merges:
- #134679 (Windows: remove readonly files)
- #136213 (Allow Rust to use a number of libc filesystem calls)
- #136530 (Implement `x perf` directly in bootstrap)
- #136601 (Detect (non-raw) borrows of null ZST pointers in CheckNull)
- #136659 (Pick the max DWARF version when LTO'ing modules with different versions )
r? `@ghost`
`@rustbot` modify labels: rollup
transmutability: fix ICE when passing wrong ADT to ASSUME
- Remove an incorrect assert that the `ASSUME` parameter has the type `Assume` and delay a bug instead.
- Since we checked the type of `ASSUME` is `Assume` (an ADT), its valtree must be a branch, so we can just unwrap it.
r? ```@jswrenn```
Add a comment pointing to ICE-136223
Fixes#136223
## Steps how the ICE happen
This explanation is based on the test case `&Some(Some(x)) = &Some(&mut Some(0))`.
The case should fail with E0596 error, but it catches the debug assertion instead.
1. For the first `&`: In check_pat_ref(), the value max_ref_mutbl becomes MutblCap::Not ([here](fdd1a3b026/compiler/rustc_hir_typeck/src/pat.rs (L2394-L2396))). Once max_ref_mutbl becomes Not, it will never be back to MutblCap::Mut.
2. For `&mut`: In peel_off_references(), because Some(x) doesn't have `&` nor `&mut`, `&mut` in `&mut Some(0)` is not consumed then default_binding_mode (def_br) becomes `ByRef::Yes(Mutability::Mut)` (around [here](fdd1a3b026/compiler/rustc_hir_typeck/src/pat.rs (L519-L536))). This will be inherited to the next step. So this pattern has the mismatch between `def_br=Yes(Mut)` and `max_ref_mutbl=Not` now.
3. For the value `0`: Because of the step 2, the default_binding_mode is `Yes(Mut)`, but max_ref_mutbl is `Not` from the step 1. It causes the assertion error [here](fdd1a3b026/compiler/rustc_hir_typeck/src/pat.rs (L427-L430)).
## What this PR fixes
Step 1 has happened from [this commit](e2f3ce9568) by deleting `no_ref_mut_behind_and` from the if block. In my understanding, after RFC3627 is released, step 1 should happen not only 2024 edition but also other editions to track MutblCap value. But for now, it should not happen for non-2024 edition. So I put it back.
NOTE: I think there is another solution - We should return an E0596 error in calc_default_binding_mode() instead of the debug assertion. Since the assertion is caused by the mismatch between `def_br = Yes(Mut)` and `max_ref_mutbl = Not`, but in my understanding this violation is the same as E0596. check_pat_ident() does returns E0596 by a similar reason [here](fdd1a3b026/compiler/rustc_hir_typeck/src/pat.rs (L837-L856)).
Pick the max DWARF version when LTO'ing modules with different versions
Currently, when rustc compiles code with `-Clto` enabled that was built
with different choices for `-Zdwarf-version`, a warning will be
reported. It's very easy to observe this by compiling most anything (eg,
"hello world") and specifying `-Clto -Zdwarf-version=5` since the
standard library is distributed with `-Zdwarf-version=4`.
This behavior isn't actually useful for a few reasons:
- From observation, LLVM chooses to pick the highest DWARF version
anyway after issuing the warning.
- Clang specifies that in this case, the max version should be picked
without a warning and as a general principle, we want to support
x-lang LTO with Clang which implies using the same module flag merge
behaviors.
- Debuggers need to be able to handle a variety of versions within the
same debugging session as you can easily have some parts of a binary
(or some dynamic libraries within an application) all compiled with
different DWARF versions.
This commit changes the module flag merge behavior to match Clang and
use the highest version of DWARF. It also adds a test to ensure this
behavior is respected in the case of two crates being LTO'd together and
adds a test to ensure no warning is printed.
Fixes#130041 which fails due to these warnings being printed
cc #103057
Generate correct terminate block under Wasm EH
This fixes failing LLVM assertions during insnsel.
Improves #135665.
r? bjorn3
^ you reviewed the PR bringing Wasm EH in, I assume this is within your area of expertise?
Currently, when rustc compiles code with `-Clto` enabled that was built
with different choices for `-Zdwarf-version`, a warning will be
reported. It's very easy to observe this by compiling most anything (eg,
"hello world") and specifying `-Clto -Zdwarf-version=5` since the
standard library is distributed with `-Zdwarf-version=4`.
This behavior isn't actually useful for a few reasons:
- from observation, LLVM chooses to pick the highest DWARF version
anyway after issuing the warning
- Clang specifies that in this case, the max version should be picked
without a warning and as a general principle, we want to support
x-lang LTO with Clang which implies using the same module flag merge
behaviors
- Debuggers need to be able to handle a variety of versions withing the
same debugging session as you can easily have some parts of a binary
(or some dynamic libraries within an application) all compiled with
different DWARF versions
This commit changes the module flag merge behavior to match Clang and
use the highest version of DWARF. It also adds a test to ensure this
behavior is respected in the case of two crates being LTO'd together and
updates the test added in the previous commit to ensure no warning is
printed.
Rollup of 6 pull requests
Successful merges:
- #136640 (Debuginfo for function ZSTs should have alignment of 8 bits, not 1 bit)
- #136648 (Add a missing `//@ needs-symlink` to `tests/run-make/libs-through-symlinks`)
- #136651 (Label mismatched parameters at the def site for foreign functions)
- #136691 (Remove Linkage::Private and Linkage::Appending)
- #136692 (add module level doc for bootstrap:utils:exec)
- #136700 (i686-unknown-hurd-gnu: bump baseline CPU to Pentium 4)
r? `@ghost`
`@rustbot` modify labels: rollup
Label mismatched parameters at the def site for foreign functions
Nice and simple. Adds parameter marking for the only missing definition type.
r? ``@compiler-errors``
Debuginfo for function ZSTs should have alignment of 8 bits, not 1 bit
In #116096, function ZSTs were made to have debuginfo that gives them an alignment of “1”. But because alignment in LLVM debuginfo is denoted in *bits*, not bytes, this resulted in an alignment specification of 1 bit instead of 1 byte.
I don't know whether this has any practical consequences, but I noticed that a test started failing when I accidentally fixed the mistake while working on #136632, so I extracted the fix (and the test adjustment) to this PR.
Rollup of 7 pull requests
Successful merges:
- #135179 (Make sure to use `Receiver` trait when extracting object method candidate)
- #136554 (Add `opt_alias_variances` and use it in outlives code)
- #136556 ([AIX] Update tests/ui/wait-forked-but-failed-child.rs to accomodate exiting and idle processes.)
- #136589 (Enable "jump to def" feature on rustc docs)
- #136615 (sys: net: Add UEFI stubs)
- #136635 (Remove outdated `base_port` calculation in std net test)
- #136682 (Move two windows process tests to tests/ui)
r? `@ghost`
`@rustbot` modify labels: rollup
Move two windows process tests to tests/ui
Spawning processes from std unit tests is not something it's well suited for so moving them into tests/ui is more robust and means we don't need to hack around `cmd.exe`.
Follow up to #136630
[AIX] Update tests/ui/wait-forked-but-failed-child.rs to accomodate exiting and idle processes.
The `wait-forked-but-failed-child.rs` test expects to see an integer PPID in the
output of the command: `ps -A -o pid,ppid,args`.
However, on AIX, sometimes an integer PPID is not available when a process is
either exiting or idle, as documented in https://www.ibm.com/docs/en/aix/7.3?topic=p-ps-command.
In these situations, a `-` is instead shown in the PPID column of the `ps` output.
This PR updates the test to accommodate this behaviour on AIX by first filtering out the
lines of the `ps` output where a `-` is found in the `PPID` column.
Add `opt_alias_variances` and use it in outlives code
...so to fix some subtle outlives bugs with precise capturing in traits, and eventually make it easier to compute variances for "forced unconstrained" trait lifetimes.
r? lcnr
Make sure to use `Receiver` trait when extracting object method candidate
In method confirmation, the `extract_existential_trait_ref` function re-extracts the object type by derefing until it reaches an object. If we're assembling methods via the `Receiver` trait, make sure we re-do our work also using the receiver trait.
Fixes#135155
cc ``@adetaylor``
Pattern Migration 2024: try to suggest eliding redundant binding modifiers
This is based on #136475. Only the last commit is new.
This is a simpler, more restrictive alternative to #136496, meant to partially address #136047. If a pattern can be migrated to Rust 2024 solely by removing redundant binding modifiers, this will make that suggestion; otherwise, it uses the old suggestion of making the pattern fully explicit.
Relevant tracking issue: #131414
``@rustbot`` label A-diagnostics A-patterns A-edition-2024
r? ``@Nadrieril``
Remove some unnecessary parens in `assert!` conditions
While working on #122661, some of these started triggering our "unnecessary parens" lints due to a change in the `assert!` desugaring. A cursory search identified a few more. Some of these have been carried from before 1.0, were a bulk rename from the previous name of `assert!` left them in that state. I went and removed as many of these unnecessary parens as possible in order to have fewer annoyances in the future if we make the lint smarter.
fix tail call checks wrt `#[track_caller]`
Only check the caller + disallow caller having the attribute.
fixes#134336
r? `@compiler-errors`
<sub>apparently there were no tests for `#[track_caller]` before... ooops</sub>
Don't reset cast kind without also updating the operand in `simplify_cast` in GVN
Consider this heavily elided segment of the pre-GVN example code that was committed as a test:
```rust
let _4: *const ();
let _5: *const [()];
let mut _6: *const ();
let _7: *mut ();
let mut _8: *const [()];
let mut _9: std::boxed::Box<()>;
let mut _10: *const ();
/* ... */
// Deref a box
_10 = copy ((_9.0: std::ptr::Unique<()>).0: std::ptr::NonNull<()>) as *const () (Transmute);
_4 = copy _10;
_6 = copy _4;
// Inlined body of `slice::from_raw_parts`, to turn a unit pointer into a slice-of-unit pointer
_5 = *const [()] from (copy _6, copy _11);
_8 = copy _5;
// Cast the raw slice-of-unit pointer back to a unit pointer
_7 = copy _8 as *mut () (PtrToPtr);
```
A malformed optimization was changing `_7` (which casted the slice-of-unit ptr to a unit ptr) to:
```
_7 = copy _5 as *mut () (Transmute);
```
...where `_8` was just replaced with `_5` bc of simple copy propagation, that part is not important... the CastKind changing to Transmute is the important part here.
In #133324, two new functionalities were implemented:
* Peeking through unsized -> sized PtrToPtr casts whose operand is `AggregateKind::RawPtr`, to turn it into PtrToPtr casts of the base of the aggregate. In this case, this allows us to see that the value of `_7` is just a ptr-to-ptr cast of `_6`.
* Folding a PtrToPtr cast of an operand which is a Transmute cast into just a single Transmute, which (theoretically) allows us to treat `_7` as a transmute into `*mut ()` of the base of the cast of `_10`, which is the place projection of `((_9.0: std::ptr::Unique<()>).0: std::ptr::NonNull<()>)`.
However, when applying those two subsequent optimizations, we must *not* update the CastKind of the final cast *unless* we also update the operand of the cast, since the operand may no longer make sense with the updated CastKind.
In this case, this is problematic because the type of `_8` is `*const [()]`, but that operand in assignment statement of `_7` does *not* get turned into something like `((_9.0: std::ptr::Unique<()>).0: std::ptr::NonNull<()>)` -- **in other words, `try_to_operand` fails** -- because GVN only turns value nodes into locals or consts, not projections of locals. So we fail to update the operand, but we still update the CastKind to Transmute, which means we now are transmuting types of different sizes (a wide pointer and a thin pointer).
r? `@scottmcm` or `@cjgillot`
Fixes#136361Fixes#135997
this commit makes `deref_into_dyn_supertrait` lint allow-by-default,
removes future incompatibility (we finally live in a broken world), and
changes the wording in the documentation.
previously documentation erroneously said that it lints against *usage*
of the deref impl, while it actually (since 104742) lints on the impl
itself (oooops, my oversight, should have updated it 2+ years ago...)
While working on #122661, some of these started triggering our "unnecessary parens" lints due to a change in the `assert!` desugaring. A cursory search identified a few more. Some of these have been carried from before 1.0, were a bulk rename from the previous name of `assert!` left them in that state. I went and removed as many of these unnecessary parens as possible in order to have fewer annoyances in the future if we make the lint smarter.
Fix accidentally not emitting overflowing literals lints anymore in patterns
This was regressed in https://github.com/rust-lang/rust/pull/134228 (not in beta yet).
The issue was that previously we nested `hir::Expr` inside `hir::PatKind::Lit`, so it was linted by the expression code.
So now I've set it up for visitors to be able to directly visit literals and get all literals
Use short ty string for binop and unop errors
```
error[E0369]: cannot add `(..., ..., ..., ...)` to `(..., ..., ..., ...)`
--> $DIR/binop.rs:10:7
|
LL | x + x;
| - ^ - (..., ..., ..., ...)
| |
| (..., ..., ..., ...)
|
= note: the full name for the type has been written to '$TEST_BUILD_DIR/$FILE.long-type-hash.txt'
= note: consider using `--verbose` to print the full type name to the console
```
```
error[E0600]: cannot apply unary operator `!` to type `(..., ..., ..., ...)`
--> $DIR/binop.rs:14:5
|
LL | !x;
| ^^ cannot apply unary operator `!`
|
= note: the full name for the type has been written to '$TEST_BUILD_DIR/$FILE.long-type-hash.txt'
= note: consider using `--verbose` to print the full type name to the console
```
CC #135919.
Ensure that we never try to monomorphize the upcasting or vtable calls of impossible dyn types
Check for impossible obligations in the `dyn Trait` type we're trying to compute its the vtable upcasting and method call slots.
r? lcnr
Pretty print pattern type values with transmute if they don't satisfy their pattern
Instead of printing `0_u32 is 1..`, we now print the default fallback rendering that we also use for invalid bools, chars, ...: `{transmute(0x00000000): (u32) is 1..=}`.
These cases can occur in mir dumps when const prop propagates a constant across a safety check that would prevent the actually UB value from existing. That's fine though, as it's dead code and we always need to allow UB in dead code.
follow-up to https://github.com/rust-lang/rust/pull/136176
cc ``@compiler-errors`` ``@scottmcm``
r? ``@RalfJung`` because of the interpreter changes
Always compute coroutine layout for eagerly emitting recursive layout errors
Detect recursive coroutine layouts even if we don't detect opaque type recursion in the new solver. This is for two reasons:
1. It helps us detect (bad) recursive async function calls in the new solver, which due to its approach to normalization causes us to not detect this via a recursive RPIT (since the opaques are more eagerly revealed in the opaque body).
* Fixes https://github.com/rust-lang/trait-system-refactor-initiative/issues/137.
2. It helps us detect (bad) recursive async functions behind AFITs. See the AFIT test that changed for the old solver too.
3. It also greatly simplifies the recursive impl trait check, since I can remove some jankness around how it handles coroutines.
Only highlight unmatchable parameters at the definition site
Followup to #136497
This generally results more focused messages in the same vein as #99635 (see `test/ui/argument-suggestions/complex.rs`). There are still some cases (e.g. `test/ui/argument-suggestions/permuted_arguments.rs`) where it might be worth highlighting the arguments. This is mitigated by the fact that a suggestion with a suggested rearrangement is given.
r? `@compiler-errors`
Pass spans around new solver
...so that when we instantiate canonical responses, we can actually have region obligations with the right span.
Within the solver itself, we still use dummy spans everywhere.
Avoid using make_direct_deprecated() in extern "ptx-kernel"
This method will be removed in the future as it produces a broken ABI that depends on cg_llvm implementation details. After this PR wasm32-unknown-unknown is the only remaining user of make_direct_deprecated().
Fixes https://github.com/rust-lang/rust/issues/117271
Blocks https://github.com/rust-lang/rust/issues/38788
Most of these are meant to test possible future improvements, but since
they cover cases the existing test suite didn't, I figure including them
now may be helpful.
Arbitrary self types v2: recursion test
Add a test for infinite recursion of an arbitrary self type.
These diagnostics aren't perfect (especially the repetition of the statement that there's too much recursion) but for now at least let's add a test to confirm that such diagnostics are emitted.
As suggested by ```@oli-obk```
Relates to #44874
r? ```@wesleywiser```
implement inherent str constructors
implement #131114
this implements
- str::from_utf8
- str::from_utf8_mut
- str::from_utf8_unchecked
- str::from_utf8_unchecked_mut
i left `std::str::from_raw_parts` and `std::str::from_raw_parts_mut` out of this as those are unstable and were not mentioned by the tracking issue or the original pull request, but i can add those here as well.
i was also unsure of what to do with the `rustc_const_(un)stable` attributes: i removed the `#[rustc_const_stable]` attribute from `str::from_utf8`, `str::from_utf8_unchecked` and `str::from_utf8_unchecked_mut`, and left the`#[rust_const_unstable]` in `str::from_utf8_mut` (btw why is that one not const stable yet with #57349 merged?).
is there a way to redirect users to the stable `std::str::from_utf8` instead of only saying "hey this is unstable"?
for now i just removed the check for `str::from_utf8` in the test in `tests/ui/suggestions/suggest-std-when-using-type.rs`.
std: move network code into `sys`
As per #117276, this PR moves `sys_common::net` and the `sys::pal::net` into the newly created `sys::net` module. In order to support #135141, I've moved all the current network code into a separate `connection` module, future functions like `hostname` can live in separate modules.
I'll probably do a follow-up PR and clean up some of the actual code, this is mostly just a reorganization.
Reject negative literals for unsigned or char types in pattern ranges and literals
It sucks a bit that we have to duplicate the work here (normal expressions just get this for free from the `ExprKind::UnOp(UnOp::Neg, ...)` typeck logic.
In https://github.com/rust-lang/rust/pull/134228 I caused
```rust
fn main() {
match 42_u8 {
-10..255 => {},
_ => {}
}
}
```
to just compile without even a lint.
I can't believe we didn't have tests for this
Amusingly https://github.com/rust-lang/rust/pull/136302 will also register a delayed bug in `lit_to_const` for this, so we'll have a redundancy if something like this fails again.
tests: Port `split-debuginfo` to rmake.rs
Part of #121876.
This PR supersedes #128754 and is co-authored with `@Oneirical.`
## Known limitations
- In general, like the `Makefile` version, this test in its present form is also somewhat funny because for the most part it merely checks for existence/absence of output artifacts but makes no attempt to actually check if the debuginfo is at all usable.
## Changes
This PR ports `tests/run-make/split-debuginfo` to rmake.rs. This is an **initial** port, and certainly could be cleaned up and/or enhanced.
The original Makefile version had several functional problems. I fixed some of them, but also left some existing issues as-is.
1. The linux/non-linux final branch had a conditional interpolation of `UNSTABLE_OPTIONS := -Zunstable-options`. However, one of the use sites was `-C $(UNSTABLE_OPTIONS) split-debuginfo`. This indicates to me that this run-make test is not run in CI under a non-linux + non-windows + non-darwin environment, because that would've failed as this would expand to `-C -Zunstable-options split-debuginfo`. I fixed this in the rmake.rs version, but I'm not sure if this distinction is worth keeping at all if it's not tested in CI.
2. There are several comments that were discovered to be wrong. I tried to fix them in the rmake.rs version as well.
3. The check for path remapping / lack of path remapping through
```make
objdump -Wi $(TMPDIR)/foo | grep DW_AT_GNU_dwo_name | (! grep $(TMPDIR)) || exit 1
```
is incorrect, because that looks at the single line of that contains `DW_AT_GNU_dwo_name`. This is unfortunately wrong because empirical evidence shows that with `objdump`[^objdump], the check actually needs to look at the attribute value of `DW_AT_comp_dir` on the previous line not `DW_AT_GNU_dwo_name`[^gnu-ext]. Example output of `objdump`:
```text
<10> DW_AT_comp_dir : (indirect string, offset: 0xafb48): /home/joe/repos/rust
<14> DW_AT_GNU_dwo_name: (indirect string, offset: 0x5d1b0): foo.foo.fc848df41df7a00d-cgu.0.rcgu.dwo
```
In the rmake.rs version I used a 2-line sliding window to check for `DW_AT_comp_dir` and `DW_AT_GNU_dwo_name`, but to look at `DW_AT_comp_dir` specifically.
4. I included a bunch of FIXMEs and ENHANCEMENTs I noticed regarding the test because I didn't want to fix them in this initial port[^enhancement].
5. The Makefile version didn't test *anything* on Windows (both windows-msvc and windows-gnu). I added some *very* basic and *very* sparse checks for windows-msvc, but I am not willing to spend the effort to expand test coverage to windows-gnu in this initial port.
6. This run-make test is way too big. But I didn't want to expend the effort of breaking this up in this initial port.
[^objdump]: the output format differs between `objdump` and `llvm-objdump`, but the same is true for `llvm-objdump` that this is looking at the wrong line.
[^gnu-ext]: AFAICT that is a GNU DWARF attribute extension, since it isn't mentioned in DWARFv5 spec
[^enhancement]: For instance, the previous path remapping check could in theory be precisely inspected by inspecting `.debug_info` section to look for attribute value of `DW_AT_comp_dir`. But that involves resolving the value of the indirect string, which means you have to: (1) look for offset into string offset table and (2) use *that* offset to find the string itself in the string table. The split part of "split-debuginfo" makes this murky for me, so I wasn't able to replace `llvm-objdump` textual output substring matches with more precise `object` + `gimli` inspections.
## Review advice
- I'm sorry for how long the rmake.rs test ended up, but a lot of it is comments and just vertical space due to formatting. If there's any ways to make this test less long / convoluted, advice would be appreciated.
- This PR *intentionally* introduces several intermediate commits for the `Makefile`, mostly to illustrate the problems I discovered when looking at the original `Makefile` version. This is intended to highlight the existing problems in the `Makefile` version for the reviewer[^squash].
- There are several intentional non-functional commits:
1. Reindent the `Makefile` to make the platform conditional gating more obvious.
2. Collapse nested if-else branches into an else if construct, which is not supported by GNU Make 3.80.
3. Remove all redundant `-C debuginfo=2` when `-g` is already specified.
- This PR is best reviewed commit-by-commit.
[^squash]: I intend to squash these intermediate commits away after the reviewer concludes that the current form of the rmake.rs test is acceptable for merge. Before then, I'll keep them to help with review.
---
try-job: x86_64-msvc
try-job: i686-msvc
try-job: i686-mingw
try-job: x86_64-mingw-1
try-job: x86_64-apple-1
try-job: aarch64-apple
try-job: test-various
Add a test for infinite recursion of an arbitrary self type.
These diagnostics aren't perfect (especially the repetition of the
statement that there's too much recursion) but for now at least
let's add a test to confirm that such diagnostics are emitted.
#[contracts::requires(...)] + #[contracts::ensures(...)]
cc https://github.com/rust-lang/rust/issues/128044
Updated contract support: attribute syntax for preconditions and postconditions, implemented via a series of desugarings that culminates in:
1. a compile-time flag (`-Z contract-checks`) that, similar to `-Z ub-checks`, attempts to ensure that the decision of enabling/disabling contract checks is delayed until the end user program is compiled,
2. invocations of lang-items that handle invoking the precondition, building a checker for the post-condition, and invoking that post-condition checker at the return sites for the function, and
3. intrinsics for the actual evaluation of pre- and post-condition predicates that third-party verification tools can intercept and reinterpret for their own purposes (e.g. creating shims of behavior that abstract away the function body and replace it solely with the pre- and post-conditions).
Known issues:
* My original intent, as described in the MCP (https://github.com/rust-lang/compiler-team/issues/759) was to have a rustc-prefixed attribute namespace (like rustc_contracts::requires). But I could not get things working when I tried to do rewriting via a rustc-prefixed builtin attribute-macro. So for now it is called `contracts::requires`.
* Our attribute macro machinery does not provide direct support for attribute arguments that are parsed like rust expressions. I spent some time trying to add that (e.g. something that would parse the attribute arguments as an AST while treating the remainder of the items as a token-tree), but its too big a lift for me to undertake. So instead I hacked in something approximating that goal, by semi-trivially desugaring the token-tree attribute contents into internal AST constucts. This may be too fragile for the long-term.
* (In particular, it *definitely* breaks when you try to add a contract to a function like this: `fn foo1(x: i32) -> S<{ 23 }> { ... }`, because its token-tree based search for where to inject the internal AST constructs cannot immediately see that the `{ 23 }` is within a generics list. I think we can live for this for the short-term, i.e. land the work, and continue working on it while in parallel adding a new attribute variant that takes a token-tree attribute alongside an AST annotation, which would completely resolve the issue here.)
* the *intent* of `-Z contract-checks` is that it behaves like `-Z ub-checks`, in that we do not prematurely commit to including or excluding the contract evaluation in upstream crates (most notably, `core` and `std`). But the current test suite does not actually *check* that this is the case. Ideally the test suite would be extended with a multi-crate test that explores the matrix of enabling/disabling contracts on both the upstream lib and final ("leaf") bin crates.
