Proper support for cross-crate recursive const stability checks
~~Stacked on top of https://github.com/rust-lang/rust/pull/132492; only the last three commits are new.~~
In a crate without `staged_api` but with `-Zforce-unstable-if-unmarked`, we now subject all functions marked with `#[rustc_const_stable_indirect]` to recursive const stability checks. We require an opt-in so that by default, a crate can be built with `-Zforce-unstable-if-unmarked` and use nightly features as usual. This property is recorded in the crate metadata so when a `staged_api` crate calls such a function, it sees the `#[rustc_const_stable_indirect]` and allows it to be exposed on stable. This, finally, will let us expose `const fn` from hashbrown on stable.
The second commit makes const stability more like regular stability: via `check_missing_const_stability`, we ensure that all publicly reachable functions have a const stability attribute -- both in `staged_api` crates and `-Zforce-unstable-if-unmarked` crates. To achieve this, we move around the stability computation so that const stability is computed after regular stability is done. This lets us access the final result of the regular stability computation, which we use so that `const fn` can inherit the regular stability (but only if that is "unstable"). Fortunately, this lets us get rid of an `Option` in `ConstStability`.
This is the last PR that I have planned in this series.
r? `@compiler-errors`
Delete the `cfg(not(parallel))` serial compiler
Since it's inception a long time ago, the parallel compiler and its cfgs have been a maintenance burden. This was a necessary evil the allow iteration while not degrading performance because of synchronization overhead.
But this time is over. Thanks to the amazing work by the parallel working group (and the dyn sync crimes), the parallel compiler has now been fast enough to be shipped by default in nightly for quite a while now.
Stable and beta have still been on the serial compiler, because they can't use `-Zthreads` anyways.
But this is quite suboptimal:
- the maintenance burden still sucks
- we're not testing the serial compiler in nightly
Because of these reasons, it's time to end it. The serial compiler has served us well in the years since it was split from the parallel one, but it's over now.
Let the knight slay one head of the two-headed dragon!
#113349
Note that the default is still 1 thread, as more than 1 thread is still fairly broken.
cc `@onur-ozkan` to see if i did the bootstrap field removal correctly, `@SparrowLii` on the sync parts
Since it's inception a long time ago, the parallel compiler and its cfgs
have been a maintenance burden. This was a necessary evil the allow
iteration while not degrading performance because of synchronization
overhead.
But this time is over. Thanks to the amazing work by the parallel
working group (and the dyn sync crimes), the parallel compiler has now
been fast enough to be shipped by default in nightly for quite a while
now.
Stable and beta have still been on the serial compiler, because they
can't use `-Zthreads` anyways.
But this is quite suboptimal:
- the maintenance burden still sucks
- we're not testing the serial compiler in nightly
Because of these reasons, it's time to end it. The serial compiler has
served us well in the years since it was split from the parallel one,
but it's over now.
Let the knight slay one head of the two-headed dragon!
Consolidate type system const evaluation under `traits::evaluate_const`
Part of #130704Fixes#128232Fixes#118545
Removes `ty::Const::{normalize_internal, eval_valtree}` and `InferCtxt::(try_)const_eval_resolve`, consolidating the associated logic into `evaluate_const` in `rustc_trait_selection`. This results in an API for `ty::Const` that is free of any normalization/evaluation functions that would be incorrect to use under `min_generic_const_args`/`associated_const_equality`/`generic_const_exprs` or, more generally, that would be incorrect to use in the presence of generic type system constants.
Moving this logic to `rustc_trait_selection` and out of `rustc_middle` is also a pre-requisite for ensuring that we do not evaluate constants whose where clauses do not hold.
From this point it should be relatively simple (hah) to implement more complex normalization of type system constants such as: checking wf'ness before invoking CTFE machinery, or being able to normalize const aliases that still refer to generic parameters.
r? `@compiler-errors`
test(configure): cover `parse_args` in `src/bootstrap/configure.py`
I was reading `src/bootstrap/configure.py` and `parse_args` function there seems complex. So I added some tests to cover it and prevent regressions.
Update mdbook to 0.4.42
This updates mdbook to 0.4.42
Changelog: https://github.com/rust-lang/mdBook/blob/master/CHANGELOG.md#mdbook-0441
There were some significant changes that I would like to get early testing on.
This also updates rust-by-example which was required due to an update to the theme file.
Only copy, rename and link `llvm-objcopy` if llvm tools are enabled
Fixes#132719.
cc `@bjorn3` who reported the bootstrapping problem for cg_clif.
cc `@davidtwco` in case this might be problematic for linux -> macOS cross-compile builds, but seems very unlikely.
cc `@albertlarsan68` (co-reviewed #131405)
r? bootstrap
Stabilize Arm64EC inline assembly
This stabilizes inline assembly for Arm64EC ("Emulation Compatible").
Corresponding reference PR: https://github.com/rust-lang/reference/pull/1653
---
From the requirements of stabilization mentioned in https://github.com/rust-lang/rust/issues/93335
> Each architecture needs to be reviewed before stabilization:
> - It must have clobber_abi.
Done in https://github.com/rust-lang/rust/pull/131332.
> - It must be possible to clobber every register that is normally clobbered by a function call.
This is possible from the time of the initial implementation.
> - Generally review that the exposed register classes make sense.
The registers available in this target are a subset of those available in the AArch64 inline assembly which is already stable.
The following registers cannot be used in Arm64EC compared to AArch64:
- `x13`, `x14`, `x23`, `x24`, `x28` (register class: `reg`)
- `v[16-31]` (register class: `vreg`)
- `p[0-15]`, `ffr` (clobber-only register class `preg`)
These are disallowed by the ABI (see also [abi docs](https://learn.microsoft.com/en-us/cpp/build/arm64ec-windows-abi-conventions?view=msvc-170#register-mapping) for `reg`/`vreg` and https://github.com/rust-lang/rust/pull/131332#issuecomment-2401189142 for `preg`).
Although not listed in the above requirements, preserves_flags is also implemented and the same as AArch64.
---
cc `@dpaoliello`
r? `@Amanieu`
`@rustbot` label O-windows O-AArch64 +A-inline-assembly +T-lang -T-compiler +needs-fcp
Update minifer version to `0.3.2`
This version fixes a few lints but the main change is that it makes `clap` dependency optional since it's only used for the binary.
r? `@notriddle`
Update grammar in wasm-c-abi's compiler flag documentation
This PR adjusts the grammar of the `wasm-c-abi` compiler flag documentation. See the inline comments within the PR for details.
interpret: get_alloc_info: also return mutability
This will be needed for https://github.com/rust-lang/miri/pull/3971
This then tuned into a larger refactor where we introduce a new type for the `get_alloc_info` return data, and we move some code to methods on `GlobalAlloc` to avoid duplicating it between the validity check and `get_alloc_info`.
Stabilize s390x inline assembly
This stabilizes inline assembly for s390x (SystemZ).
Corresponding reference PR: https://github.com/rust-lang/reference/pull/1643
---
From the requirements of stabilization mentioned in https://github.com/rust-lang/rust/issues/93335
> Each architecture needs to be reviewed before stabilization:
> - It must have clobber_abi.
Done in https://github.com/rust-lang/rust/pull/130630.
> - It must be possible to clobber every register that is normally clobbered by a function call.
Done in the PR that added support for clobber_abi.
> - Generally review that the exposed register classes make sense.
The followings can be used as input/output:
- `reg` (`r[0-10]`, `r[12-14]`): General-purpose register
- `reg_addr` (`r[1-10]`, `r[12-14]`): General-purpose register except `r0` which is evaluated as zero in an address context
This class is needed because `r0`, which may be allocated when using the `reg` class, cannot be used as a register in certain contexts. This is identical to the `a` constraint in LLVM and GCC. See https://github.com/rust-lang/rust/pull/119431 for details.
- `freg` (`f[0-15]`): Floating-point register
The followings are clobber-only:
- `vreg` (`v[0-31]`): Vector register
Technically `vreg` should be able to accept `#[repr(simd)]` types as input/output if the unstable `vector` target feature added is enabled, but `core::arch` has no s390x vector type and both `#[repr(simd)]` and `core::simd` are unstable. Everything related is unstable, so the fact that this is currently a clobber-only should not be considered a stabilization blocker. (https://github.com/rust-lang/rust/issues/130869 tracks unstable stuff here)
- `areg` (`a[2-15]`): Access register
All of the above register classes except `reg_addr` are needed for `clobber_abi`.
The followings cannot be used as operands for inline asm (see also [getReservedRegs](https://github.com/llvm/llvm-project/blob/llvmorg-19.1.0/llvm/lib/Target/SystemZ/SystemZRegisterInfo.cpp#L258-L282) and [SystemZELFRegisters](https://github.com/llvm/llvm-project/blob/llvmorg-19.1.0/llvm/lib/Target/SystemZ/SystemZRegisterInfo.h#L107-L128) in LLVM):
- `r11`: frame pointer
- `r15`: stack pointer
- `a0`, `a1`: Reserved for system use
- `c[0-15]` (control register) Reserved by the kernel
Although not listed in the above requirements, `preserves_flags` is implemented in https://github.com/rust-lang/rust/pull/111331.
---
cc ``@uweigand``
r? ``@Amanieu``
``@rustbot`` label +O-SystemZ +A-inline-assembly
