Simplify `LazyAttrTokenStream`
`LazyAttrTokenStream` is an unpleasant type: `Lrc<Box<dyn ToAttrTokenStream>>`. Why does it look like that?
- There are two `ToAttrTokenStream` impls, one for the lazy case, and one for the case where we already have an `AttrTokenStream`.
- The lazy case (`LazyAttrTokenStreamImpl`) is implemented in `rustc_parse`, but `LazyAttrTokenStream` is defined in `rustc_ast`, which does not depend on `rustc_parse`. The use of the trait lets `rustc_ast` implicitly depend on `rustc_parse`. This explains the `dyn`.
- `LazyAttrTokenStream` must have a `size_of` as small as possible, because it's used in many AST nodes. This explains the `Lrc<Box<_>>`, which keeps it to one word. (It's required `Lrc<dyn _>` would be a fat pointer.)
This PR moves `LazyAttrTokenStreamImpl` (and a few other token stream things) from `rustc_parse` to `rustc_ast`. This lets us replace the `ToAttrTokenStream` trait with a two-variant enum and also remove the `Box`, changing `LazyAttrTokenStream` to `Lrc<LazyAttrTokenStreamInner>`. Plus it does a few cleanups.
r? `@petrochenkov`
These appeared in a later nightly. In compiler-builtins we can apply the
suggestion, but in `libm` we need to ignore them since `fx::from_bits`
is not `const` at the MSRV.
`clippy::uninlined_format_args` also seems to have gotten stricter, so
fix those here.
This commit does the following.
- Changes it from `Lrc<Box<dyn ToAttrTokenStream>>` to
`Lrc<LazyAttrTokenStreamInner>`.
- Reworks `LazyAttrTokenStreamImpl` as `LazyAttrTokenStreamInner`, which
is a two-variant enum.
- Removes the `ToAttrTokenStream` trait and the two impls of it.
The recursion limit must be increased in some crates otherwise rustdoc
aborts.
Introduce Arena::try_alloc_from_iter.
`alloc_from_iter` already collects the iterator for reentrancy. So adding an early exit for a fallible iterator integrates naturally into the code. This avoids the other solution to allocate and dump the allocation.
The previous implementation was inconsistent about transitions that
apply for an init byte. For example, when answering a query, an init
byte could use corresponding init transition. Init byte could also use
uninit transition, but only when the corresponding init transition was
absent. This behaviour was incompatible with DFA union construction.
Define an uninit transition to match an uninit byte only and update
implementation accordingly. To describe that `Tree::uninit` is valid
for any value, build an automaton that accepts any byte value.
Additionally, represent byte ranges uniformly as a pair of integers to
avoid special case for uninit byte.
Replace the \01__gnu_mcount_nc to LLVM intrinsic for additional ARM targets
This is an extension to #113814 which seems to have missed two targets which also need this patch for instrumentation with `-Z instrument-mcount` to work correctly.
For anyone who might stumble over this issue again in the future: As a workaround one can dump the current target configuration using
```
rustc +nightly -Z unstable-options --target armv7-unknown-linux-gnueabihf --print target-spec-json
```
(assuming `armv7-unknown-linux-gnueabihf` is the target to build for) add the line
```
"llvm-mcount-intrinsic": "llvm.arm.gnu.eabi.mcount",
```
and compile with
```
RUSTFLAGS="-Z instrument-mcount -C passes=ee-instrument<post-inline>" cargo +nightly build -Z build-std --target <path to directory with modified target config>/armv7-unknown-linux-gnueabihf.json
```
It might be necessary to set the compiler for cross compiling using something like
```
export TARGET_CC=arm-linux-gnueabihf-gcc
```
unwind: bump `unwinding` dependency to 0.2.6
Xous now fails to compile under nightly, due to the recent change where `#[naked]` must now be wrapped in `unsafe(...)`. The `unwinding` crate was updated to account for this.
With the following `bootstrap.toml`:
```
profile = "library"
change-id = 138934
[build]
build-stage = 2
target = ["riscv32imac-unknown-xous-elf"]
[rust]
std-features = ["panic-unwind"]
download-rustc = false
```
The build fails when trying unwinding v0.2.5:
```
$ ./x.py build
[...]
Compiling unwinding v0.2.5
error: unsafe attribute used without unsafe
--> /home/user/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/unwinding-0.2.5/src/unwinder/arch/riscv32.rs:176:3
|
176 | #[naked]
| ^^^^^ usage of unsafe attribute
|
help: wrap the attribute in `unsafe(...)`
|
176 | #[unsafe(naked)]
| +++++++ +
error: could not compile `unwinding` (lib) due to 1 previous error
warning: build failed, waiting for other jobs to finish...
Build completed unsuccessfully in 0:06:26
$
```
This patch updates `unwinding` to v0.2.6, which now wraps all issues of `naked` in `unsafe()`.
PassWrapper: adapt for llvm/llvm-project@d3d856ad84
LLVM 21 moves to making it more explicit what this function call is doing, but nothing has changed behaviorally, so for now we just adjust to using the new name of the function.
`@rustbot` label llvm-main
compiletest: Remove the libtest-based executor and its dependency
Now that #140288 has landed and the new compiletest executor is used by default, we can now move forward with removing the libtest dependency from compiletest.
My hope is that after landing this, we can configure bootstrap to build compiletest with the pre-built stage0 library by default, instead of the in-tree stage0 library. That would give the stage0 redesign one less thing to worry about.
---
This PR has deliberately been kept small and simple, to make it easier to revert if necessary. Further cleanup can take palce after we're confident that it won't need to be reverted.
r? jieyouxu
Blocker for https://github.com/rust-lang/rust/pull/119899
