Rollup of 6 pull requests
Successful merges:
- #110435 (rustdoc-json: Add test for field ordering.)
- #111891 (feat: `riscv-interrupt-{m,s}` calling conventions)
- #114377 (test_get_dbpath_for_term(): handle non-utf8 paths (fix FIXME))
- #114469 (Detect method not found on arbitrary self type with different mutability)
- #114587 (Convert Const to Allocation in smir)
- #114670 (Don't use `type_of` to determine if item has intrinsic shim)
Failed merges:
- #114599 (Add impl trait declarations to SMIR)
r? `@ghost`
`@rustbot` modify labels: rollup
Don't use `type_of` to determine if item has intrinsic shim
When we're calling `resolve_instance` on an inline const, we were previously looking at the `type_of` for that const, seeing that it was an `extern "intrinsic"` fn def, and treating it as if we were computing the instance of that intrinsic itself. This is incorrect.
Instead, we should be using the def-id of the item we're computing to determine if it's an intrinsic.
Fixes#114660
Detect method not found on arbitrary self type with different mutability
```
error[E0599]: no method named `x` found for struct `Pin<&S>` in the current scope
--> $DIR/arbitrary_self_type_mut_difference.rs:11:18
|
LL | Pin::new(&S).x();
| ^ help: there is a method with a similar name: `y`
|
note: method is available for `Pin<&mut S>`
--> $DIR/arbitrary_self_type_mut_difference.rs:6:5
|
LL | fn x(self: Pin<&mut Self>) {}
| ^^^^^^^^^^^^^^^^^^^^^^^^^^
```
Related to #57994, as one of the presented cases can lead to code like this.
test_get_dbpath_for_term(): handle non-utf8 paths (fix FIXME)
Removes a FIXME for #9639
Part of #44366 which is E-help-wanted
The remaining two FIXMEs for #9639 are considerably more complicated, so I will create separate PRs for them.
feat: `riscv-interrupt-{m,s}` calling conventions
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]: 9281af2ecf/src/lib.rs (L440-L469)
[implemented by]: b7fb2a3fec/llvm/lib/Target/RISCV/RISCVRegisterInfo.cpp (L61-L67)
[callee-save]: 973f1fe7a8/llvm/lib/Target/RISCV/RISCVCallingConv.td (L30-L37)
[rfc]: https://github.com/rust-lang/rfcs/pull/3246
Sync rustc_codegen_cranelift
A couple of small bug fixes this time. In addition I fixed the test suite after the introduction of `#![deny(internal_feature)]` broke it.
r? `@ghost`
`@rustbot` label +A-codegen +A-cranelift +T-compiler
[`slow_vector_initialization`]: clarify why `Vec::new()` + resize is worse
#11198 extended this lint to also warn on `Vec::new()` + `resize(0, len)`, but did not update the lint documentation, so it left some confused (https://github.com/rust-lang/rust-clippy/issues/10938#issuecomment-1663880083).
This PR should make it a bit more clear. (cc `@djc` `@vi` what do you think about this?)
<details>
<summary>More details</summary>
Godbolt for `Vec::new()` + `.resize(x, 0)`: https://godbolt.org/z/e7q9xc9rG
The resize call first does a normal allocation (`__rust_alloc`):
```asm
alloc::raw_vec::finish_grow:
...
cmp qword ptr [rcx + 8], 0
je .LBB1_7 ; if capacity == 0 -> LBB1_7
.LBB1_7:
...
call qword ptr [rip + __rust_alloc@GOTPCREL]
```
*Then* a memset for zero initialization:
```asm
example::f:
...
xor esi, esi ; 0
call qword ptr [rip + memset@GOTPCREL]
```
------------
Godbolt for `vec![0; len]`: https://godbolt.org/z/M3vr53vWY
Important bit:
```asm
example::f:
...
call qword ptr [rip + __rust_alloc_zeroed@GOTPCREL]
```
</details>
changelog: [`slow_vector_initialization`]: clarify why `Vec::new()` + resize is worse than `vec![0; len]`
Rollup of 6 pull requests
Successful merges:
- #113939 (open pidfd in child process and send to the parent via SOCK_SEQPACKET+CMSG)
- #114548 (Migrate a trait selection error to use diagnostic translation)
- #114606 (fix: not insert missing lifetime for `ConstParamTy`)
- #114634 (Mention riscv64-linux-android support in Android documentation)
- #114638 (Remove old RPITIT tests (revisions were removed))
- #114641 (Rename copying `ascii::Char` methods from `as_` to `to_`)
r? `@ghost`
`@rustbot` modify labels: rollup
Rename copying `ascii::Char` methods from `as_` to `to_`
Tracking issue: #110998.
The [API guidelines][naming] describe `as_` as used for borrowed -> borrowed operations, and `to_` for
owned -> owned operations on `Copy` types.
[naming]: https://rust-lang.github.io/api-guidelines/naming.html
Mention riscv64-linux-android support in Android documentation
This CL brings the android.md file in-line with the list of supported targets from platform-support.md.
Followup to https://github.com/rust-lang/rust/pull/112858
r? `@Mark-Simulacrum`
fix: not insert missing lifetime for `ConstParamTy`
Fixes#113462
We should ignore the missing lifetime, as it's illegal to include a lifetime in a const param.
r? ``@compiler-errors``
open pidfd in child process and send to the parent via SOCK_SEQPACKET+CMSG
This avoids using `clone3` when a pidfd is requested while still getting it in a 100% race-free manner by passing it up from the child process.
This should solve most concerns in #82971
The change in 07f855d781 introduced a
trailing numeral of some kind after the `extern crate
compiler_builtins`, which appears to have caused at least two false
negatives (654b924 and 657fd24). Instead, this change normalizes the
test output to ignore the number (of symbols rustc recognizes?) to avoid
needing to re-`--bless` these two tests for unrelated changes.
These new interrupt calling conventions are not themselves stabilized,
but there are other unstable calling conventions present in the SMIR
mapping (e.g. AVR interrupts) and the mapping appears to be "complete"
so far, with no obvious way to represent unstable conventions separately
from the stable ones.
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]: 9281af2ecf/src/lib.rs (L440-L469)
[implemented by]: b7fb2a3fec/llvm/lib/Target/RISCV/RISCVRegisterInfo.cpp (L61-L67)
[callee-save]: 973f1fe7a8/llvm/lib/Target/RISCV/RISCVCallingConv.td (L30-L37)
[rfc]: https://github.com/rust-lang/rfcs/pull/3246
Restrict linker version script of proc-macro crates to just its two symbols
Restrict linker version script of proc-macro crates to just the two symbols of each proc-macro crate.
The main known effect of doing this is to stop including `#[no_mangle]` symbols in the linker version script.
Background:
The combination of a proc-macro crate with an import of another crate that itself exports a no_mangle function was broken for a period of time, because:
* In PR #99944 we stopped exporting no_mangle symbols from proc-macro crates; proc-macro crates have a very limited interface and are meant to be treated as a blackbox to everything except rustc itself. However: he constructed linker version script still referred to them, but resolving that discrepancy was left as a FIXME in the code, tagged with issue #99978.
* In PR #108017 we started telling the linker to check (via the`--no-undefined-version` linker invocation flag) that every symbol referenced in the "linker version script" is provided as linker input. So the unresolved discrepancy from #99978 started surfacing as a compile-time error (e.g. #111888).
Fix#111888Fix#99978.
