Inline u8::is_utf8_char_boundary
Since Rust beta, Rust is incapable of inlining this function in the following example function.
```rust
pub fn safe_substr_to(s: &str, mut length: usize) -> &str {
loop {
if let Some(s) = s.get(..length) {
return s;
}
length -= 1;
}
}
```
When compiled with beta or nightly compiler on Godbolt with `-C opt-level=3` flag it prints the following assembly.
```asm
example::safe_substr_to:
push r15
push r14
push r12
push rbx
push rax
mov r14, rdi
test rdx, rdx
je .LBB0_8
mov rbx, rdx
mov r15, rsi
mov r12, qword ptr [rip + core::num::<impl u8>::is_utf8_char_boundary@GOTPCREL]
jmp .LBB0_4
.LBB0_2:
je .LBB0_9
.LBB0_3:
add rbx, -1
je .LBB0_8
.LBB0_4:
cmp rbx, r15
jae .LBB0_2
movzx edi, byte ptr [r14 + rbx]
call r12
test al, al
je .LBB0_3
mov r15, rbx
jmp .LBB0_9
.LBB0_8:
xor r15d, r15d
.LBB0_9:
mov rax, r14
mov rdx, r15
add rsp, 8
pop rbx
pop r12
pop r14
pop r15
ret
```
`qword ptr [rip + core::num::<impl u8>::is_utf8_char_boundary@GOTPCREL]` is not inlined. `-C remark=all` outputs the following message:
```
note: /rustc/7bccde19767082c7865a12902fa614ed4f8fed73/library/core/src/str/mod.rs:214:25: inline: _ZN4core3num20_$LT$impl$u20$u8$GT$21is_utf8_char_boundary17hace9f12f5ba07a7fE will not be inlined into _ZN4core3str21_$LT$impl$u20$str$GT$16is_char_boundary17hf2587e9a6b8c5e43E because its definition is unavailable
```
Stable compiler outputs more reasonable code:
```asm
example::safe_substr_to:
mov rcx, rdx
mov rax, rdi
test rdx, rdx
je .LBB0_9
mov rdx, rsi
jmp .LBB0_4
.LBB0_2:
cmp rdx, rcx
je .LBB0_7
.LBB0_3:
add rcx, -1
je .LBB0_9
.LBB0_4:
cmp rcx, rdx
jae .LBB0_2
cmp byte ptr [rax + rcx], -64
jl .LBB0_3
mov rdx, rcx
.LBB0_7:
ret
.LBB0_9:
xor edx, edx
ret
```
Link to std::io's platform-specific behavior disclaimer
This PR adds some links in standard library documentation to point to https://doc.rust-lang.org/std/io/index.html#platform-specific-behavior.
> ### Platform-specific behavior
>
> Many I/O functions throughout the standard library are documented to indicate what various library or syscalls they are delegated to. This is done to help applications both understand what’s happening under the hood as well as investigate any possibly unclear semantics. Note, however, that this is informative, not a binding contract. The implementation of many of these functions are subject to change over time and may call fewer or more syscalls/library functions.
Many of the `std::fs` APIs already link to this disclaimer when discussing system calls.
Fix yet another Box<T, A> ICE
Fixes#95036.
This widens the special case from #94414 to make sure that boxes with a custom allocator are never directly dereferenced.
parallel_compiler: hide dependencies behind feature
Separate dependencies for `parallel_compiler` feature, so they will not be compiled if feature not selected, reducing number of compiled crates from 238 to 224.
Rollup of 6 pull requests
Successful merges:
- #95301 (Remove `Nonterminal::NtTT`.)
- #95314 (Tell users that `||` operators are not currently supported in let chain expressions)
- #95350 (resolve: Simplify some diagnostic code to avoid an ICE)
- #95370 ([bootstrap] Don't print `Suite not skipped` unless `--verbose` is set)
- #95390 (Ignore doc comments in a declarative macro matcher.)
- #95401 (Remove duplicated and unused test files)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Ignore doc comments in a declarative macro matcher.
Fixes#95267. Reverts to the old behaviour before #95159 introduced a
regression.
r? `@petrochenkov`
[bootstrap] Don't print `Suite not skipped` unless `--verbose` is set
This was so verbose before that it made it hard to see what effect the flag actually had.
Before:
```
Set({test::src/tools/tidy}) not skipped for "bootstrap::test::Tidy" -- not in [src/test/ui, src/test/mir-opt/, src/test/debuginfo, src/test/ui-fulldeps]
Skipping Suite(test::src/test/ui) because it is excluded
Suite(test::src/test/run-pass-valgrind) not skipped for "bootstrap::test::RunPassValgrind" -- not in [src/test/ui, src/test/mir-opt/, src/test/debuginfo, src/test/ui-fulldeps]
Skipping Suite(test::src/test/mir-opt) because it is excluded
Suite(test::src/test/codegen) not skipped for "bootstrap::test::Codegen" -- not in [src/test/ui, src/test/mir-opt/, src/test/debuginfo, src/test/ui-fulldeps]
Suite(test::src/test/codegen-units) not skipped for "bootstrap::test::CodegenUnits" -- not in [src/test/ui, src/test/mir-opt/, src/test/debuginfo, src/test/ui-fulldeps]
Suite(test::src/test/assembly) not skipped for "bootstrap::test::Assembly" -- not in [src/test/ui, src/test/mir-opt/, src/test/debuginfo, src/test/ui-fulldeps]
Suite(test::src/test/incremental) not skipped for "bootstrap::test::Incremental" -- not in [src/test/ui, src/test/mir-opt/, src/test/debuginfo, src/test/ui-fulldeps]
Skipping Suite(test::src/test/debuginfo) because it is excluded
Skipping Suite(test::src/test/ui-fulldeps) because it is excluded
... about 100 more lines ...
```
After:
```
Skipping Suite(test::src/test/ui) because it is excluded
Skipping Suite(test::src/test/mir-opt) because it is excluded
Skipping Suite(test::src/test/debuginfo) because it is excluded
Skipping Suite(test::src/test/ui-fulldeps) because it is excluded
```
resolve: Simplify some diagnostic code to avoid an ICE
No need to resolve those paths, they are already resolved, we just need to take the results from `partial_res_map`.
Fixes https://github.com/rust-lang/rust/issues/95327
Tell users that `||` operators are not currently supported in let chain expressions
Tells that `||` operators are not currently supported instead of not allowed. See https://github.com/rust-lang/rust/issues/53667#issuecomment-1066075876
In other words, this PR is pretty much trivial.
Remove `Nonterminal::NtTT`.
It's only needed for macro expansion, not as a general element in the
AST. This commit removes it, adds `NtOrTt` for the parser and macro
expansion cases, and renames the variants in `NamedMatch` to better
match the new type.
r? `@petrochenkov`
rustdoc: add 🔒 to items with restricted visibility
This change marks items with restricted visibility with 🔒 when building with `--document-private-items`:
<img width="278" alt="Screen Shot 2022-03-20 at 23 50 24" src="https://user-images.githubusercontent.com/509209/159189513-9e4b09bb-6785-41a5-bfe2-df02f83f8641.png">
There also appears a “Restricted Visibility” tooltip when hovering over the emoji.
---
The original PR for reference:
This change makes private items slightly transparent (similar to `unstable` items in rustc):
<img width="272" alt="Screen Shot 2022-03-16 at 22 17 43" src="https://user-images.githubusercontent.com/509209/158692627-a1f6f5ec-e043-4aa2-9352-8d2b15c31c08.png">
I found myself using `--document-private-items` a lot recently because I find the documentation of private internals quite helpful when working on a larger project. However, not being able to distinguish private from public items (see #87785) when looking at the documentation makes this somewhat cumbersome.
This PR addresses the third suggestion of issue #87785 by marking private items typographically. It seems to me that the other suggestions are more involved but this is at least a first step.
A private item is also made slightly transparent in the path displayed in the header of a page:
<img width="467" alt="Screen Shot 2022-03-16 at 22 19 51" src="https://user-images.githubusercontent.com/509209/158692885-0bbd3417-3c0b-486f-b8ab-99c05c6fa7ca.png">
I am looking forward to feedback and suggestions.
Make fatal DiagnosticBuilder yield `!`
Fatal errors should really be fatal, so emitting them should cause us to exit at the same time.
Fine with just throwing away these changes if they're not worthwhile. Also, maybe we want to use an uninhabited enum instead of `!`.
r? `@eddyb` who has been working on `DiagnosticBuilder` stuff, feel free to reassign.
Skip needless bitset for debuginfo
Found this while digging around looking at the inlining logic.
Seemed obvious enough so I decided to try to take care of it.
Is this what you had in mind, `@eddyb?`
