[beta] backport
This PR backports:
- #113334: Revert the lexing of `c"…"` string literals
- #113231: Fix `dropping_copy_types` lint from linting in match-arm with side-effects
- #112794: Fix linker failures when #[global_allocator] is used in a dependency
r? `@Mark-Simulacrum`
This prevents #113238 from hitting stable while we sort out options for avoiding it. The downgrade
is expected to not affect any users on stable, since it primarily affects tier 3 targets.
[`let_with_type_underscore`]: Don't emit on locals from procedural macros
closes#10498
changelog: [`let_with_type_underscore`]: Don't emit on locals from procedural macros
The type inference of argument-position closures and async blocks
regressed in 1.70 as the evaluation order of async blocks changed, as
they are not implicitly wrapped in an identity-function anymore.
Fixes#112225 by making sure the evaluation order stays the same as it
used to.
[beta] backports + stage0 bump
This bumps the beta branch to use 1.70 as the bootstrap compiler, and backports:
* https://github.com/rust-lang/rust/pull/112070
r? `@Mark-Simulacrum`
Rollup of 6 pull requests
Successful merges:
- #108630 (Fix docs for `alloc::realloc`)
- #109084 (rustc driver: Remove argument 0 before at-expansion to prevent ICE)
- #111181 (fix(parse): return unpected when current token is EOF)
- #111656 (Use an unbounded lifetime in `String::leak`.)
- #111946 (rustdoc: Add `ItemTemplate` trait and related functions to avoid repetitively wrapping existing functions)
- #112018 (Clean up usage of `cx.tcx` when `tcx` is already set into a variable)
r? `@ghost`
`@rustbot` modify labels: rollup
Clean up usage of `cx.tcx` when `tcx` is already set into a variable
I discovered a few cases where `cx.tcx` (and equivalents) was used whereas `tcx` was already stored into a variable. In those cases, better to just use `tcx` directly.
r? `@notriddle`
rustc driver: Remove argument 0 before at-expansion to prevent ICE
Under Unix-based operating systems, when I execute rustc by setting argv0 to ``@/dev/null`,` it will expand command-line arguments from this file, leading to an empty arglist, which then triggers an ICE by trying to remove first argument.
The panic message is this:
```
thread 'main' panicked at 'range start index 1 out of range for slice of length 0', compiler/rustc_driver/src/lib.rs:972:17
```
My fix is to remove the first argument before expanding arguments.
<details>
<summary>Full backtrace</summary>
```sh
% (exec -a `@/dev/null` `rustup which rustc`)
thread 'main' panicked at 'range start index 1 out of range for slice of length 0', compiler/rustc_driver/src/lib.rs:972:17
stack backtrace:
0: 0x7fcec776659a - std::backtrace_rs::backtrace::libunwind::trace::h595f06c70adcc478
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/std/src/../../backtrace/src/backtrace/libunwind.rs:93:5
1: 0x7fcec776659a - std::backtrace_rs::backtrace::trace_unsynchronized::h177a0149c76cdde9
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
2: 0x7fcec776659a - std::sys_common::backtrace::_print_fmt::hc0701fd2c3530c58
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/std/src/sys_common/backtrace.rs:65:5
3: 0x7fcec776659a - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::hd4cd115d8750fd6c
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/std/src/sys_common/backtrace.rs:44:22
4: 0x7fcec77c839e - core::fmt::write::h93e2f5923c7eca08
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/core/src/fmt/mod.rs:1213:17
5: 0x7fcec7756be5 - std::io::Write::write_fmt::h8162dbb45f0b9e62
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/std/src/io/mod.rs:1682:15
6: 0x7fcec7766365 - std::sys_common::backtrace::_print::h1835ef8a8f9066da
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/std/src/sys_common/backtrace.rs:47:5
7: 0x7fcec7766365 - std::sys_common::backtrace::print::hcb5e6388b9235f41
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/std/src/sys_common/backtrace.rs:34:9
8: 0x7fcec776912f - std::panicking::default_hook::{{closure}}::h9c084969ccf9a722
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/std/src/panicking.rs:267:22
9: 0x7fcec7768e6b - std::panicking::default_hook::h68fa2ba3c3c6c12f
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/std/src/panicking.rs:286:9
10: 0x7fcecaab56e4 - <rustc_driver[f4ad927b3c57833d]::DEFAULT_HOOK::{closure#0}::{closure#0} as core[d16e85342ea223d9]::ops::function::FnOnce<(&core[d16e85342ea223d9]::panic::panic_info::PanicInfo,)>>::call_once::{shim:vtable#0}
11: 0x7fcec776996a - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::h4e6ced11e07d8b24
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/alloc/src/boxed.rs:2002:9
12: 0x7fcec776996a - std::panicking::rust_panic_with_hook::h8d5c434518ef298c
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/std/src/panicking.rs:692:13
13: 0x7fcec77696e9 - std::panicking::begin_panic_handler::{{closure}}::hf33414f5dabf6faf
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/std/src/panicking.rs:579:13
14: 0x7fcec7766a4c - std::sys_common::backtrace::__rust_end_short_backtrace::hc50389427413bb75
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/std/src/sys_common/backtrace.rs:137:18
15: 0x7fcec77693f2 - rust_begin_unwind
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/std/src/panicking.rs:575:5
16: 0x7fcec77c4d43 - core::panicking::panic_fmt::h2de7a7938f816de8
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/core/src/panicking.rs:64:14
17: 0x7fcec77cb492 - core::slice::index::slice_start_index_len_fail_rt::h0c87d85ce11d10f6
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/core/src/slice/index.rs:53:5
18: 0x7fcec77cb416 - core::slice::index::slice_start_index_len_fail::h504609f2a6b168d1
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/core/src/slice/index.rs:41:9
19: 0x7fceca0eca1f - rustc_driver[f4ad927b3c57833d]::handle_options
20: 0x7fceca0e037f - <rustc_driver[f4ad927b3c57833d]::RunCompiler>::run
21: 0x7fceca0dfd0d - <core[d16e85342ea223d9]::panic::unwind_safe::AssertUnwindSafe<rustc_driver[f4ad927b3c57833d]::main::{closure#0}> as core[d16e85342ea223d9]::ops::function::FnOnce<()>>::call_once
22: 0x7fceca17ce89 - rustc_driver[f4ad927b3c57833d]::main
23: 0x564f5f008a87 - rustc_main[f164605d1302e295]::main
24: 0x564f5f008973 - std[3da461b304582a2c]::sys_common::backtrace::__rust_begin_short_backtrace::<fn(), ()>
25: 0x564f5f008969 - <std[3da461b304582a2c]::rt::lang_start<()>::{closure#0} as core[d16e85342ea223d9]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
26: 0x7fcec774795c - core::ops::function::impls::<impl core::ops::function::FnOnce<A> for &F>::call_once::h699977d052768608
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/core/src/ops/function.rs:287:13
27: 0x7fcec774795c - std::panicking::try::do_call::h4e121e623c70f903
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/std/src/panicking.rs:483:40
28: 0x7fcec774795c - std::panicking::try::hf9d919e062bc178a
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/std/src/panicking.rs:447:19
29: 0x7fcec774795c - std::panic::catch_unwind::h7a7b12272684cb97
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/std/src/panic.rs:140:14
30: 0x7fcec774795c - std::rt::lang_start_internal::{{closure}}::hd96b0eb4844b8762
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/std/src/rt.rs:148:48
31: 0x7fcec774795c - std::panicking::try::do_call::h1af1f88f4f92a22c
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/std/src/panicking.rs:483:40
32: 0x7fcec774795c - std::panicking::try::hf20d7abea7f0f097
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/std/src/panicking.rs:447:19
33: 0x7fcec774795c - std::panic::catch_unwind::hb0e084c3a9c042e4
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/std/src/panic.rs:140:14
34: 0x7fcec774795c - std::rt::lang_start_internal::hca9d5c7277f5b67c
at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/std/src/rt.rs:148:20
35: 0x564f5f008ab7 - main
36: 0x7fcec74a1790 - <unknown>
37: 0x7fcec74a184a - __libc_start_main
38: 0x564f5f00899e - <unknown>
39: 0x0 - <unknown>
error: internal compiler error: unexpected panic
note: the compiler unexpectedly panicked. this is a bug.
note: we would appreciate a bug report: https://github.com/rust-lang/rust/issues/new?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md
note: rustc 1.68.0 (2c8cc3432 2023-03-06) running on x86_64-unknown-linux-gnu
query stack during panic:
end of query stack
```
</details>
I also checked if I can trigger a similar problem by passing empty argument list to `execve`, but at least under Linux, it seems to always insert an empty first argument if there are none.
Fix docs for `alloc::realloc`
Fixes#108546.
Corrects the docs for `alloc::realloc` to bring the safety constraints into line with `Layout::from_size_align_unchecked`'s constraints.
Rework handling of recursive panics
This PR makes 2 changes to how recursive panics works (a panic while handling a panic).
1. The panic count is no longer used to determine whether to force an immediate abort. This allows code like the following to work without aborting the process immediately:
```rust
struct Double;
impl Drop for Double {
fn drop(&mut self) {
// 2 panics are active at once, but this is fine since it is caught.
std::panic::catch_unwind(|| panic!("twice"));
}
}
let _d = Double;
panic!("once");
```
Rustc already generates appropriate code so that any exceptions escaping out of a `Drop` called in the unwind path will immediately abort the process.
2. Any panics while the panic hook is executing will force an immediate abort. This is necessary to avoid potential deadlocks like #110771 where a panic happens while holding the backtrace lock. We don't even try to print the panic message in this case since the panic may have been caused by `Display` impls.
Fixes#110771
