Recommend to never display zero disambiguators when demangling v0 symbols
This PR extends the [v0 symbol mangling documentation](https://doc.rust-lang.org/rustc/symbol-mangling/v0.html) with the strong recommendation that demanglers should never display zero-disambiguators, especially when dealing with `crate-root`.
Being able to rely on `C3foo` to be rendered as `foo` (i.e. without explicit disambiguator value) rather than as `foo[0]` allows the compiler to encode things like new basic types in a backward compatible way. This idea has been originally proposed by `@eddyb` in [the discussion around supporting `f16` and `f128` in the v0 mangling scheme](https://github.com/rust-lang/rust/pull/122106). It is a generally useful mechanism for supporting a certain class of new elements in the v0 mangling scheme in a backward compatible way (whether as a temporary workaround until downstream tooling has picked up grammar changes or as a permanent encoding).
cc `@tgross35`
Tait must be constrained if in sig
r? `@compiler-errors`
kind of reverts https://github.com/rust-lang/rust/pull/62423, but that PR only removed cycles in cases that we want to forbid now anyway.
see https://rust-lang.zulipchat.com/#narrow/stream/315482-t-compiler.2Fetc.2Fopaque-types/topic/lcnr.20oli.20meeting/near/370712246 for related discussion and motivating example
a TAIT showing up in a signature doesn't just mean it can register a hidden type, but that it must.
This is the [design the types team decided upon](https://hackmd.io/QOsEaEJtQK-XDS_xN4UyQA#Proposal-preferred) for the following reasons
* avoids a hypothetical situation where getting smarter in trait solving could cause new cycle errors or new inference errors to show up, where today something is treated as opaque.
* avoids having the situation where a (minor?) change to a function body causes an error, because its TAIT usage suddenly isn't "opaque enough" anymore.
* avoids having to explain why in some cases you need to put a Tait into a tiny module together with its defining usages. Now you basically gotta always do this, the moment a Tait is in a signature that isn't in the defining scope.
* avoids false-cycle errors
* anything diverging from this pattern needs to either
* move the TAIT declaration and defining function into their own helper sub module
* use the attributes we'll provide in the future to explicitly opt in or out of being in the defining scope
fixes#117861
reverts #125362 cc `@Nilstrieb` `@joboet`
Update cargo
14 commits in b1feb75d062444e2cee8b3d2aaa95309d65e9ccd..4dcbca118ab7f9ffac4728004c983754bc6a04ff
2024-06-07 20:16:17 +0000 to 2024-06-11 16:27:02 +0000
- Add local registry overlays (rust-lang/cargo#13926)
- docs(change): Don't mention non-existent workspace.badges (rust-lang/cargo#14042)
- test: migrate binary_name to snapbox (rust-lang/cargo#14041)
- Bump to 0.82.0; update changelog (rust-lang/cargo#14040)
- tests: Migrate alt_registry to snapbox (rust-lang/cargo#14031)
- fix: proc-macro example from dep no longer affects feature resolution (rust-lang/cargo#13892)
- chore: Bump cargo-util-schemas to 0.5 (rust-lang/cargo#14038)
- chore(deps): update rust crate pulldown-cmark to 0.11.0 (rust-lang/cargo#14037)
- fix: remove `__CARGO_GITOXIDE_DISABLE_LIST_FILES` env var (rust-lang/cargo#14036)
- chore(deps): update rust crate itertools to 0.13.0 (rust-lang/cargo#13998)
- fix(toml): remove `lib.plugin` key support and make it warning (rust-lang/cargo#13902)
- chore(deps): update compatible (rust-lang/cargo#13995)
- fix: using `--release/debug` and `--profile` together becomes an error (rust-lang/cargo#13971)
- fix(toml): Convert warnings that `licence` and `readme` files do not exist into errors (rust-lang/cargo#13921)
r? ghost
We already do this for a number of crates, e.g. `rustc_middle`,
`rustc_span`, `rustc_metadata`, `rustc_span`, `rustc_errors`.
For the ones we don't, in many cases the attributes are a mess.
- There is no consistency about order of attribute kinds (e.g.
`allow`/`deny`/`feature`).
- Within attribute kind groups (e.g. the `feature` attributes),
sometimes the order is alphabetical, and sometimes there is no
particular order.
- Sometimes the attributes of a particular kind aren't even grouped
all together, e.g. there might be a `feature`, then an `allow`, then
another `feature`.
This commit extends the existing sorting to all compiler crates,
increasing consistency. If any new attribute line is added there is now
only one place it can go -- no need for arbitrary decisions.
Exceptions:
- `rustc_log`, `rustc_next_trait_solver` and `rustc_type_ir_macros`,
because they have no crate attributes.
- `rustc_codegen_gcc`, because it's quasi-external to rustc (e.g. it's
ignored in `rustfmt.toml`).
Make `ObligationEmittingRelation`s emit `Goal` rather than `Obligation`
Helps avoid needing to uplift `Obligation` into the solver. We still can't get rid of `ObligationCause`, but we can keep it as an associated type for `InferCtxtLike` and just give it a `dummy` function.
There's some shuttling between `Goal` and `Obligation` that may be perf-sensitive... Let's see what rust-timer says.
r? lcnr
Edition 2024: Make `!` fall back to `!`
This PR changes never type fallback to be `!` (the never type itself) in the next, 2024, edition.
This makes the never type's behavior more intuitive (in 2024 edition) and is the first step of the path to stabilize it.
r? `@compiler-errors`
PR #125443 will reformat all the use declarations in the repo. This
would break a patch kept in `rustc_codegen_cranelift` that gets applied
to `library/std/src/sys/pal/windows/rand.rs`.
So this commit formats the use declarations in
`library/std/src/sys/pal/windows/rand.rs` in advance of #125443 and
updates the patch file accordingly.
The motivation is that #125443 is a huge change and we want to get
fiddly little changes like this out of the way so it can be nothing more
than an `x fmt --all`.
Rollup of 6 pull requests
Successful merges:
- #115974 (Split core's PanicInfo and std's PanicInfo)
- #125659 (Remove usage of `isize` in example)
- #125669 (CI: Update riscv64gc-linux job to Ubuntu 22.04, rename to riscv64gc-gnu)
- #125684 (Account for existing bindings when suggesting `pin!()`)
- #126055 (Expand list of trait implementers in E0277 when calling rustc with --verbose)
- #126174 (Migrate `tests/run-make/prefer-dylib` to `rmake.rs`)
r? `@ghost`
`@rustbot` modify labels: rollup
Account for existing bindings when suggesting `pin!()`
When we encounter a situation where we'd suggest `pin!()`, we now account for that expression existing as part of an assignment and provide an appropriate suggestion:
```
error[E0599]: no method named `poll` found for type parameter `F` in the current scope
--> $DIR/pin-needed-to-poll-3.rs:19:28
|
LL | impl<F> Future for FutureWrapper<F>
| - method `poll` not found for this type parameter
...
LL | let res = self.fut.poll(cx);
| ^^^^ method not found in `F`
|
help: consider pinning the expression
|
LL ~ let mut pinned = std::pin::pin!(self.fut);
LL ~ let res = pinned.as_mut().poll(cx);
|
```
Fix#125661.
CI: Update riscv64gc-linux job to Ubuntu 22.04, rename to riscv64gc-gnu
Together with joshua.zivkovic@codethink.co.uk, we've been starting to explore improving the state of the `riscv64gc-unknown-linux-gnu` target. Additionally, I'm looking to add support for this platform in [Ferrocene](https://github.com/ferrocene/ferrocene) ([Related PR](https://github.com/ferrocene/ferrocene/pull/618)).
There currently exists a `src/ci/docker/host-x86_64/disabled/riscv64gc-linux` job for the CI, however it is currently experiencing errors.
<details>
<summary>Errors</summary>
```bash
$ DEPLOY=1 ./src/ci/docker/run.sh riscv64gc-linux
# ...
[RUSTC-TIMING] addr2line test:false 0.371
[RUSTC-TIMING] gimli test:false 3.159
[RUSTC-TIMING] object test:false 4.249
error: linking with `riscv64-linux-gnu-gcc` failed: exit status: 1
|
= note: LC_ALL="C" PATH="/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/lib/rustlib/x86_64-unknown-linux-gnu/bin:/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/lib/rustlib/x86_64-unknown-linux-gnu/bin:/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/lib/rustlib/x86_64-unknown-linux-gnu/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin" VSLANG="1033" "riscv64-linux-gnu-gcc" "-Wl,--version-script=/tmp/rustcQaIpWi/list" "-Wl,--no-undefined-version" "/tmp/rustcQaIpWi/symbols.o" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-std/riscv64gc-unknown-linux-gnu/release/deps/std-ff89a9732cd5d858.std.1b5d59225ff40bd2-cgu.0.rcgu.o" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-std/riscv64gc-unknown-linux-gnu/release/deps/std-ff89a9732cd5d858.dalhl7sfna1ffn4nhy6pyfa7f.rcgu.rmeta" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-std/riscv64gc-unknown-linux-gnu/release/deps/std-ff89a9732cd5d858.ef0znsdf1ihn2bjkmclodhclp.rcgu.o" "-Wl,--as-needed" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-std/riscv64gc-unknown-linux-gnu/release/deps" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-std/release/deps" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-std/riscv64gc-unknown-linux-gnu/release/build/compiler_builtins-9e9a40064e2f2bd3/out" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/lib/rustlib/riscv64gc-unknown-linux-gnu/lib" "-Wl,-Bstatic" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-std/riscv64gc-unknown-linux-gnu/release/deps/libpanic_unwind-d968371aba64a26c.rlib" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-std/riscv64gc-unknown-linux-gnu/release/deps/libobject-da5b6473912e89d6.rlib" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-std/riscv64gc-unknown-linux-gnu/release/deps/libmemchr-9cfa08d2baa3643e.rlib" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-std/riscv64gc-unknown-linux-gnu/release/deps/libaddr2line-06e0d2153cecb6ce.rlib" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-std/riscv64gc-unknown-linux-gnu/release/deps/libgimli-6fdf5551cec83840.rlib" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-std/riscv64gc-unknown-linux-gnu/release/deps/librustc_demangle-8ada6466f763fa2e.rlib" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-std/riscv64gc-unknown-linux-gnu/release/deps/libstd_detect-edc0d12d029c4c86.rlib" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-std/riscv64gc-unknown-linux-gnu/release/deps/libhashbrown-9c782935934c8c14.rlib" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-std/riscv64gc-unknown-linux-gnu/release/deps/librustc_std_workspace_alloc-b6984e43b381efa4.rlib" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-std/riscv64gc-unknown-linux-gnu/release/deps/libminiz_oxide-37ee29bf49ccaa96.rlib" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-std/riscv64gc-unknown-linux-gnu/release/deps/libadler-591133f6804fa0f4.rlib" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-std/riscv64gc-unknown-linux-gnu/release/deps/libunwind-94d98075f42175f3.rlib" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-std/riscv64gc-unknown-linux-gnu/release/deps/libcfg_if-e267a7b9dd7af3a7.rlib" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-std/riscv64gc-unknown-linux-gnu/release/deps/liblibc-503571a038f8d9fd.rlib" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-std/riscv64gc-unknown-linux-gnu/release/deps/liballoc-e36c72a5cf0ee45f.rlib" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-std/riscv64gc-unknown-linux-gnu/release/deps/librustc_std_workspace_core-076c2b8501e25f03.rlib" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-std/riscv64gc-unknown-linux-gnu/release/deps/libcore-c446fff80486d0bb.rlib" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-std/riscv64gc-unknown-linux-gnu/release/deps/libcompiler_builtins-26dc6b5e31e1fdb9.rlib" "-Wl,-Bdynamic" "-lgcc_s" "-lutil" "-lrt" "-lpthread" "-lm" "-ldl" "-lc" "-Wl,--eh-frame-hdr" "-Wl,-z,noexecstack" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/lib/rustlib/riscv64gc-unknown-linux-gnu/lib" "-o" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-std/riscv64gc-unknown-linux-gnu/release/deps/libstd-ff89a9732cd5d858.so" "-shared" "-Wl,-z,relro,-z,now" "-Wl,-O1" "-nodefaultlibs" "-Wl,-z,origin" "-Wl,-rpath,$ORIGIN/../lib"
# ...
/usr/lib/gcc-cross/riscv64-linux-gnu/9/../../../../riscv64-linux-gnu/bin/ld: failed to merge target specific data of file /checkout/obj/build/x86_64-unknown-linux-gnu/stage2-std/riscv64gc-unknown-linux-gnu/release/deps/libcompiler_builtins-26dc6b5e31e1fdb9.rlib(compiler_builtins-26dc6b5e31e1fdb9.compiler_builtins.74504a151a6bdbbf-cgu.124.rcgu.o)
/usr/lib/gcc-cross/riscv64-linux-gnu/9/../../../../riscv64-linux-gnu/bin/ld: -march=rv64i2p1_m2p0_a2p1_f2p2_d2p2_c2p0_zicsr2p0: unsupported ISA subset `z'
/usr/lib/gcc-cross/riscv64-linux-gnu/9/../../../../riscv64-linux-gnu/bin/ld: failed to merge target specific data of file /checkout/obj/build/x86_64-unknown-linux-gnu/stage2-std/riscv64gc-unknown-linux-gnu/release/deps/libcompiler_builtins-26dc6b5e31e1fdb9.rlib(compiler_builtins-26dc6b5e31e1fdb9.compiler_builtins.74504a151a6bdbbf-cgu.004.rcgu.o)
collect2: error: ld returned 1 exit status
[RUSTC-TIMING] std test:false 15.138
error: could not compile `std` (lib) due to 1 previous error
Building bootstrap
Build completed unsuccessfully in 0:04:41
local time: Tue May 28 16:25:09 UTC 2024
network time: Tue, 28 May 2024 16:25:17 GMT
```
</details>
This PR fixes the breakage enough to get the tests running. It does so through bringing the `riscv64gc-unknown-linux-gnu` related test job in line with other related jobs, adopting many of the recent changes present in `src/ci/docker/host-x86_64/armhf-gnu` such as:
* Using Ubuntu 22.04
* Installing a more narrowly scoped package set
* Using `curl` instead of `debootstrap` to set up the root
* No longer patching `busybox`
* Removing the `cmake.sh` script related steps
## Justifying Renaming `riscv64gc-linux` to `riscv64gc-gnu`
The `src/ci/docker/host-x86_64/disabled/riscv64gc-linux` job runs the tests for `risv64gc-unknown-linux-gnu`, it is based off `src/ci/docker/host-x86_64/armhf-gnu`.
There are other jobs that follow a `$arch-gnu` naming scheme:
* `src/ci/docker/host-x86_64/armhf-gnu`
* `src/ci/docker/host-x86_64/x86_64-gnu`
* `src/ci/docker/host-aarch64/aarch64-gnu`
It follows that the name `src/ci/docker/host-x86_64/disabled/riscv64gc-linux` should be `src/ci/docker/host-x86_64/disabled/riscv64gc-gnu`, like the others.
## Testing
> [!NOTE]
> `riscv64gc-unknown-linux-gnu` is a [**Tier 2 with Host Tools** platform](https://doc.rust-lang.org/beta/rustc/platform-support.html), all tests may not necessarily pass! There is work in https://github.com/rust-lang/rust/pull/125220 which helps fix several related tests.
You can test out the renamed job:
```sh
DEPLOY=1 ./src/ci/docker/run.sh riscv64gc-gnu
```
`DEPLOY=1` helps reproduce the CI's environment and also avoids the chance of a `llvm-c/BitReader.h` error (detailed in https://github.com/rust-lang/rust/issues/85424 and https://github.com/rust-lang/rust/issues/56650).
<details>
<summary>Sample of output (expected test failure)</summary>
```bash
$ DEPLOY=1 ./src/ci/docker/run.sh riscv64gc-gnu
# ...
test [ui] tests/ui/where-clauses/where-clause-method-substituion-rpass.rs ... ok
failures:
---- [ui] tests/ui/debuginfo/debuginfo-emit-llvm-ir-and-split-debuginfo.rs stdout ----
error: test compilation failed although it shouldn't!
status: exit status: 1
command: env -u RUSTC_LOG_COLOR RUSTC_ICE="0" RUST_BACKTRACE="short" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/debuginfo/debuginfo-emit-llvm-ir-and-split-debuginfo.rs" "-Zthreads=1" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Z" "ignore-directory-in-diagnostics-source-blocks=/cargo" "-Z" "ignore-directory-in-diagnostics-source-blocks=/checkout/vendor" "--sysroot" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2" "--target=riscv64gc-unknown-linux-gnu" "--check-cfg" "cfg(FALSE)" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zwrite-long-types-to-disk=no" "-Cstrip=debuginfo" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/debuginfo/debuginfo-emit-llvm-ir-and-split-debuginfo" "-A" "unused" "-A" "internal_features" "-Crpath" "-Lnative=/checkout/obj/build/riscv64gc-unknown-linux-gnu/native/rust-test-helpers" "-Clinker=riscv64-linux-gnu-gcc" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/debuginfo/debuginfo-emit-llvm-ir-and-split-debuginfo/auxiliary" "-g" "--emit=llvm-ir" "-Csplit-debuginfo=unpacked"
stdout: none
--- stderr -------------------------------
error: `-Csplit-debuginfo=unpacked` is unstable on this platform
error: aborting due to 1 previous error
------------------------------------------
failures:
[ui] tests/ui/debuginfo/debuginfo-emit-llvm-ir-and-split-debuginfo.rs
test result: FAILED. 5 passed; 1 failed; 16897 ignored; 0 measured; 0 filtered out; finished in 410.99ms
Some tests failed in compiletest suite=ui mode=ui host=x86_64-unknown-linux-gnu target=riscv64gc-unknown-linux-gnu
local time: Tue May 28 16:28:22 UTC 2024
network time: Tue, 28 May 2024 16:28:30 GMT
```
</details>
try-job: riscv64gc-gnu
Split core's PanicInfo and std's PanicInfo
`PanicInfo` is used in two ways:
1. As argument to the `#[panic_handler]` in `no_std` context.
2. As argument to the [panic hook](https://doc.rust-lang.org/stable/std/panic/fn.set_hook.html) in `std` context.
In situation 1, the `PanicInfo` always has a *message* (of type `fmt::Arguments`), but never a *payload* (of type `&dyn Any`).
In situation 2, the `PanicInfo` always has a *payload* (which is often a `String`), but not always a *message*.
Having these as the same type is annoying. It means we can't add `.message()` to the first one without also finding a way to properly support it on the second one. (Which is what https://github.com/rust-lang/rust/issues/66745 is blocked on.)
It also means that, because the implementation is in `core`, the implementation cannot make use of the `String` type (which doesn't exist in `core`): 0692db1a90/library/core/src/panic/panic_info.rs (L171-L172)
This also means that we cannot easily add a useful method like `PanicInfo::payload_as_str() -> Option<&str>` that works for both `&'static str` and `String` payloads.
I don't see any good reasons for these to be the same type, other than historical reasons.
---
This PR is makes 1 and 2 separate types. To try to avoid breaking existing code and reduce churn, the first one is still named `core::panic::PanicInfo`, and `std::panic::PanicInfo` is a new (deprecated) alias to `PanicHookInfo`. The crater run showed this as a viable option, since people write `core::` when defining a `#[panic_handler]` (because they're in `no_std`) and `std::` when writing a panic hook (since then they're definitely using `std`). On top of that, many definitions of a panic hook don't specify a type at all: they are written as a closure with an inferred argument type.
(Based on some thoughts I was having here: https://github.com/rust-lang/rust/pull/115561#issuecomment-1725830032)
---
For the release notes:
> We have renamed `std::panic::PanicInfo` to `std::panic::PanicHookInfo`. The old name will continue to work as an alias, but will result in a deprecation warning starting in Rust 1.82.0.
>
> `core::panic::PanicInfo` will remain unchanged, however, as this is now a *different type*.
>
> The reason is that these types have different roles: `std::panic::PanicHookInfo` is the argument to the [panic hook](https://doc.rust-lang.org/stable/std/panic/fn.set_hook.html) in std context (where panics can have an arbitrary payload), while `core::panic::PanicInfo` is the argument to the [`#[panic_handler]`](https://doc.rust-lang.org/nomicon/panic-handler.html) in no_std context (where panics always carry a formatted *message*). Separating these types allows us to add more useful methods to these types, such as `std::panic::PanicHookInfo::payload_as_str()` and `core::panic::PanicInfo::message()`.
Print `token::Interpolated` with token stream pretty printing.
This is a step towards removing `token::Interpolated` (#124141). It unavoidably changes the output of the `stringify!` macro, generally for the better.
r? `@petrochenkov`
run-make-support: add wrapper for `fs` operations
Suggested by #125728.
The point of this wrapper is to stop silent fails caused by forgetting to `unwrap` `fs` functions. However, functions like `fs::read` which return something and get stored in a variable should cause a failure on their own if they are not unwrapped (as the `Result` will be stored in the variable, and something will be done on that `Result` that should have been done to its contents). Is it still pertinent to wrap `fs::read_to_string`, `fs::metadata` and so on?
Closes: https://github.com/rust-lang/rust/issues/125728
try-job: x86_64-msvc
try-job: i686-mingw
