Similar to prior support added for the mips430, avr, and x86 targets
this change implements the rough equivalent of clang's
[`__attribute__((interrupt))`][clang-attr] for riscv targets, enabling
e.g.
```rust
static mut CNT: usize = 0;
pub extern "riscv-interrupt-m" fn isr_m() {
unsafe {
CNT += 1;
}
}
```
to produce highly effective assembly like:
```asm
pub extern "riscv-interrupt-m" fn isr_m() {
420003a0: 1141 addi sp,sp,-16
unsafe {
CNT += 1;
420003a2: c62a sw a0,12(sp)
420003a4: c42e sw a1,8(sp)
420003a6: 3fc80537 lui a0,0x3fc80
420003aa: 63c52583 lw a1,1596(a0) # 3fc8063c <_ZN12esp_riscv_rt3CNT17hcec3e3a214887d53E.0>
420003ae: 0585 addi a1,a1,1
420003b0: 62b52e23 sw a1,1596(a0)
}
}
420003b4: 4532 lw a0,12(sp)
420003b6: 45a2 lw a1,8(sp)
420003b8: 0141 addi sp,sp,16
420003ba: 30200073 mret
```
(disassembly via `riscv64-unknown-elf-objdump -C -S --disassemble ./esp32c3-hal/target/riscv32imc-unknown-none-elf/release/examples/gpio_interrupt`)
This outcome is superior to hand-coded interrupt routines which, lacking
visibility into any non-assembly body of the interrupt handler, have to
be very conservative and save the [entire CPU state to the stack
frame][full-frame-save]. By instead asking LLVM to only save the
registers that it uses, we defer the decision to the tool with the best
context: it can more accurately account for the cost of spills if it
knows that every additional register used is already at the cost of an
implicit spill.
At the LLVM level, this is apparently [implemented by] marking every
register as "[callee-save]," matching the semantics of an interrupt
handler nicely (it has to leave the CPU state just as it found it after
its `{m|s}ret`).
This approach is not suitable for every interrupt handler, as it makes
no attempt to e.g. save the state in a user-accessible stack frame. For
a full discussion of those challenges and tradeoffs, please refer to
[the interrupt calling conventions RFC][rfc].
Inside rustc, this implementation differs from prior art because LLVM
does not expose the "all-saved" function flavor as a calling convention
directly, instead preferring to use an attribute that allows for
differentiating between "machine-mode" and "superivsor-mode" interrupts.
Finally, some effort has been made to guide those who may not yet be
aware of the differences between machine-mode and supervisor-mode
interrupts as to why no `riscv-interrupt` calling convention is exposed
through rustc, and similarly for why `riscv-interrupt-u` makes no
appearance (as it would complicate future LLVM upgrades).
[clang-attr]: https://clang.llvm.org/docs/AttributeReference.html#interrupt-risc-v
[full-frame-save]: https://github.com/esp-rs/esp-riscv-rt/blob/9281af2ecffe13e40992917316f36920c26acaf3/src/lib.rs#L440-L469
[implemented by]: https://github.com/llvm/llvm-project/blob/b7fb2a3fec7c187d58a6d338ab512d9173bca987/llvm/lib/Target/RISCV/RISCVRegisterInfo.cpp#L61-L67
[callee-save]: https://github.com/llvm/llvm-project/blob/973f1fe7a8591c7af148e573491ab68cc15b6ecf/llvm/lib/Target/RISCV/RISCVCallingConv.td#L30-L37
[rfc]: https://github.com/rust-lang/rfcs/pull/3246
Add hotness data to LLVM remarks
Slight improvement of https://github.com/rust-lang/rust/pull/113040. This makes sure that if PGO is used, remarks generated using `-Zremark-dir` will include the `Hotness` attribute.
r? `@tmiasko`
Map RPIT duplicated lifetimes back to fn captured lifetimes
Use the [`lifetime_mapping`](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_hir/hir/struct.OpaqueTy.html#structfield.lifetime_mapping) to map an RPIT's captured lifetimes back to the early- or late-bound lifetimes from its parent function. We may be going thru several layers of mapping, since opaques can be nested, so we introduce `TyCtxt::map_rpit_lifetime_to_fn_lifetime` to loop through several opaques worth of mapping, and handle turning it into a `ty::Region` as well.
We can then use this instead of the identity substs for RPITs in `check_opaque_meets_bounds` to address #114285.
We can then also use `map_rpit_lifetime_to_fn_lifetime` to properly install bidirectional-outlives predicates for both RPITs and RPITITs. This addresses #114601.
I based this on #114574, but I don't actually know how much of that PR we still need, so some code may be redundant now... 🤷
---
Fixes#114597Fixes#114579Fixes#114285
Also fixes#114601, since it turns out we had other bugs with RPITITs and their duplicated lifetime params 😅.
Supersedes #114574
r? `@oli-obk`
[rustc_data_structures][base_n][perf] Remove unnecessary utf8 check.
Since all output characters taken from `BASE_64` are valid UTF8 chars there is no need to waste cycles on validation.
Even though it's obviously a perf win, I've also used a [benchmark](https://gist.github.com/ttsugriy/e1e63c07927d8f31e71695a9c617bbf3) on M1 MacBook Air with following results:
```
Running benches/base_n_benchmark.rs (target/release/deps/base_n_benchmark-825fe5895b5c2693)
push_str/old time: [14.670 µs 14.852 µs 15.074 µs]
Found 11 outliers among 100 measurements (11.00%)
4 (4.00%) high mild
7 (7.00%) high severe
push_str/new time: [12.573 µs 12.674 µs 12.801 µs]
Found 11 outliers among 100 measurements (11.00%)
7 (7.00%) high mild
4 (4.00%) high severe
```
rustc_interface: Dismantle `register_plugins` query
It did three independent things:
- Constructed `LintStore`
- Prepared incremental directories and dep graph
- Initialized some fields in `Session`
The `LintStore` construction (now `passes::create_lint_store`) is more or less left in place.
The incremental stuff is now moved into `fn dep_graph_future`.
This helps us to start loading the dep graph a bit earlier.
The `Session` field initialization is moved to tcx construction point.
Now that tcx is constructed early these fields don't even need to live in `Session`, they can live in tcx instead and be initialized at its creation (see the FIXME).
Three previously existing `rustc_interface` queries are de-querified (`register_plugins`, `dep_graph_future`, `dep_graph`) because they are only used locally in `fn global_ctxt` and their results don't need to be saved elsewhere.
On the other hand, `crate_types` and `stable_crate_id` are querified.
They are used from different places and their use is very similar to the existing `crate_name` query in this regard.
Structurally normalize weak and inherent in new solver
It seems pretty obvious to me that we should be normalizing weak and inherent aliases too, since they can always be normalized. This PR still leaves open the question of what to do with opaques, though 💀
**Also**, we need to structurally resolve the target of a coercion, for the UI test to work.
r? `@lcnr`
Store the laziness of type aliases in their `DefKind`
Previously, we would treat paths referring to type aliases as *lazy* type aliases if the current crate had lazy type aliases enabled independently of whether the crate which the alias was defined in had the feature enabled or not.
With this PR, the laziness of a type alias depends on the crate it is defined in. This generally makes more sense to me especially if / once lazy type aliases become the default in a new edition and we need to think about *edition interoperability*:
Consider the hypothetical case where the dependency crate has an older edition (and thus eager type aliases), it exports a type alias with bounds & a where-clause (which are void but technically valid), the dependent crate has the latest edition (and thus lazy type aliases) and it uses that type alias. Arguably, the bounds should *not* be checked since at any time, the dependency crate should be allowed to change the bounds at will with a *non*-major version bump & without negatively affecting downstream crates.
As for the reverse case (dependency: lazy type aliases, dependent: eager type aliases), I guess it rules out anything from slight confusion to mild annoyance from upstream crate authors that would be caused by the compiler ignoring the bounds of their type aliases in downstream crates with older editions.
---
This fixes#114468 since before, my assumption that the type alias associated with a given weak projection was lazy (and therefore had its variances computed) did not necessarily hold in cross-crate scenarios (which [I kinda had a hunch about](https://github.com/rust-lang/rust/pull/114253#discussion_r1278608099)) as outlined above. Now it does hold.
`@rustbot` label F-lazy_type_alias
r? `@oli-obk`
Remove arm crypto target feature
Follow-up to https://github.com/rust-lang/stdarch/pull/1407.
LLVM has moved away from a combined `crypto` feature on both aarch64 and arm, and we did the same on aarch64, but were deferred from doing the same on arm due to compatibility with older LLVM.
As the minimum LLVM version has increased, we can now remove this (unstable) target feature on arm.
r? `@Amanieu`
Warn when #[macro_export] is applied on decl macros
The existing code checks if `#[macro_export]` is being applied to an item other than a macro, and warns in that case, but fails to take into account macros 2.0/decl macros, despite the attribute having no effect on these macros.
This PR adds a special case for decl macros with the aforementioned attribute, so that the warning is a bit more precise. Instead of just saying "this attribute has no effect", hint towards the fact that decl macros get exported and resolved like regular items.
It also removes a `#[macro_export]` attribute which was applied on one of `core`'s decl macros.
- core: Remove #[macro_export] from `debug_assert_matches`
- check_attrs: Warn when #[macro_export] is used on macros 2.0
Avoid exporting __rust_alloc_error_handler_should_panic more than once.
Exporting `__rust_alloc_error_handler_should_panic` multiple times causes `ld.gold` to balk with: `error: version script assignment of to symbol __rust_alloc_error_handler_should_panic failed: symbol not defined`
Specifically this breaks builds of 1.70.0 and newer on DragonFly and YoctoProject with `ld.gold`. Builds with `ld.bfd` and `lld` should be unaffected.
http://errors.yoctoproject.org/Errors/Details/708194/
The compiler should emit a more specific error when the `#[macro_export]`
attribute is present on a decl macro, instead of silently ignoring it.
This commit adds the required error message in rustc_passes/messages.ftl,
as well as a note. A new variant is added to the `errors::MacroExport`
enum, specifically for the case where the attribute is added to a macro
2.0.
Rollup of 9 pull requests
Successful merges:
- #113568 (Fix spurious test failure with `panic=abort`)
- #114196 (Bubble up nested goals from equation in `predicates_for_object_candidate`)
- #114485 (Add trait decls to SMIR)
- #114495 (Set max_atomic_width for AVR to 16)
- #114496 (Set max_atomic_width for sparc-unknown-linux-gnu to 32)
- #114510 (llvm-wrapper: adapt for LLVM API changes)
- #114562 (stabilize abi_thiscall)
- #114570 ([miri][typo] Fix a typo in a vector_block comment.)
- #114573 (CI: do not hide error logs in a group)
r? `@ghost`
`@rustbot` modify labels: rollup
Bubble up nested goals from equation in `predicates_for_object_candidate`
This used to be needed for https://github.com/rust-lang/rust/pull/114036#discussion_r1273987510, but since it's no longer, I'm opening this as a separate PR. This also fixes one ICEing UI test: (`tests/ui/unboxed-closures/issue-53448.rs`)
r? `@lcnr`
Make `unconditional_recursion` warning detect recursive drops
Closes#55388
Also closes#50049 unless we want to keep it for the second example which this PR does not solve, but I think it is better to track that work in #57965.
r? `@oli-obk` since you are the mentor for #55388
Unresolved questions:
- [x] There are two false positives that must be fixed before merging (see diff). I suspect the best way to solve them is to perform analysis after drop elaboration instead of before, as now, but I have not explored that any further yet. Could that be an option? **Answer:** Yes, that solved the problem.
`@rustbot` label +T-compiler +C-enhancement +A-lint
Add a new `compare_bytes` intrinsic instead of calling `memcmp` directly
As discussed in #113435, this lets the backends be the place that can have the "don't call the function if n == 0" logic, if it's needed for the target. (I didn't actually *add* those checks, though, since as I understood it we didn't actually need them on known targets?)
Doing this also let me make it `const` (unstable), which I don't think `extern "C" fn memcmp` can be.
cc `@RalfJung` `@Amanieu`
Rollup of 6 pull requests
Successful merges:
- #114535 (bump schannel, miow to drop windows-sys 0.42)
- #114542 (interpret: use ConstPropNonsense for more const-prop induced issues)
- #114543 (add tests for some fixed ConstProp ICEs)
- #114550 (Generate better function argument names in global_allocator expansion)
- #114556 (Issue numbers are enforced on active features; remove FIXME)
- #114558 (Remove FIXME about NLL diagnostic that is already improved)
Failed merges:
- #114485 (Add trait decls to SMIR)
r? `@ghost`
`@rustbot` modify labels: rollup
Issue numbers are enforced on active features; remove FIXME
Since https://github.com/rust-lang/rust/pull/51090 tidy enforces that active features have an issue number, so remove the FIXME.
This PR is part of #44366 which is E-help-wanted.
Steal MIR for CTFE when possible.
Some bodies, like constants, have CTFE MIR but no optimized MIR.
In that case, have `mir_for_ctfe` steal the MIR instead of cloning it.
Seth Pellegrino