rust/compiler/rustc_data_structures/src/lib.rs
bors 0d7b2fb797 Auto merge of #123441 - saethlin:fixed-len-file-names, r=oli-obk
Stabilize the size of incr comp object file names

The current implementation does not produce stable-length paths, and we create the paths in a way that makes our allocation behavior is nondeterministic. I think `@eddyb` fixed a number of other cases like this in the past, and this PR fixes another one. Whether that actually matters I have no idea, but we still have bimodal behavior in rustc-perf and the non-uniformity in `find` and `ls` was bothering me.

I've also removed the truncation of the mangled CGU names. Before this PR incr comp paths look like this:
```
target/debug/incremental/scratch-38izrrq90cex7/s-gux6gz0ow8-1ph76gg-ewe1xj434l26w9up5bedsojpd/261xgo1oqnd90ry5.o
```
And after, they look like this:
```
target/debug/incremental/scratch-035omutqbfkbw/s-gux6borni0-16r3v1j-6n64tmwqzchtgqzwwim5amuga/55v2re42sztc8je9bva6g8ft3.o
```

On the one hand, I'm sure this will break some people's builds because they're on Windows and only a few bytes from the path length limit. But if we're that seriously worried about the length of our file names, I have some other ideas on how to make them smaller. And last time I deleted some hash truncations from the compiler, there was a huge drop in the number if incremental compilation ICEs that were reported: https://github.com/rust-lang/rust/pull/110367https://github.com/rust-lang/rust/pull/110367

---

Upon further reading, this PR actually fixes a bug. This comment says the CGU names are supposed to be a fixed-length hash, and before this PR they aren't: ca7d34efa9/compiler/rustc_monomorphize/src/partitioning.rs (L445-L448)
2024-05-03 17:41:48 +00:00

163 lines
3.9 KiB
Rust

//! Various data structures used by the Rust compiler. The intention
//! is that code in here should not be *specific* to rustc, so that
//! it can be easily unit tested and so forth.
//!
//! # Note
//!
//! This API is completely unstable and subject to change.
// tidy-alphabetical-start
#![allow(internal_features)]
#![allow(rustc::default_hash_types)]
#![allow(rustc::potential_query_instability)]
#![cfg_attr(not(parallel_compiler), feature(cell_leak))]
#![deny(unsafe_op_in_unsafe_fn)]
#![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
#![doc(rust_logo)]
#![feature(allocator_api)]
#![feature(array_windows)]
#![feature(ascii_char)]
#![feature(ascii_char_variants)]
#![feature(auto_traits)]
#![feature(cfg_match)]
#![feature(core_intrinsics)]
#![feature(extend_one)]
#![feature(hash_raw_entry)]
#![feature(hasher_prefixfree_extras)]
#![feature(lazy_cell)]
#![feature(lint_reasons)]
#![feature(macro_metavar_expr)]
#![feature(map_try_insert)]
#![feature(maybe_uninit_uninit_array)]
#![feature(min_specialization)]
#![feature(negative_impls)]
#![feature(never_type)]
#![feature(ptr_alignment_type)]
#![feature(rustc_attrs)]
#![feature(rustdoc_internals)]
#![feature(strict_provenance)]
#![feature(test)]
#![feature(thread_id_value)]
#![feature(type_alias_impl_trait)]
#![feature(unwrap_infallible)]
// tidy-alphabetical-end
#[macro_use]
extern crate tracing;
use std::fmt;
pub use rustc_index::static_assert_size;
/// This calls the passed function while ensuring it won't be inlined into the caller.
#[inline(never)]
#[cold]
pub fn outline<F: FnOnce() -> R, R>(f: F) -> R {
f()
}
pub mod base_n;
pub mod binary_search_util;
pub mod captures;
pub mod flat_map_in_place;
pub mod flock;
pub mod fx;
pub mod graph;
pub mod intern;
pub mod jobserver;
pub mod macros;
pub mod obligation_forest;
pub mod sip128;
pub mod small_c_str;
pub mod snapshot_map;
pub mod svh;
pub use ena::snapshot_vec;
pub mod memmap;
pub mod sorted_map;
#[macro_use]
pub mod stable_hasher;
mod atomic_ref;
pub mod fingerprint;
pub mod marker;
pub mod profiling;
pub mod sharded;
pub mod stack;
pub mod sync;
pub mod tiny_list;
pub mod transitive_relation;
pub mod vec_linked_list;
pub mod work_queue;
pub use atomic_ref::AtomicRef;
pub mod aligned;
pub mod frozen;
mod hashes;
pub mod owned_slice;
pub mod packed;
pub mod sso;
pub mod steal;
pub mod tagged_ptr;
pub mod temp_dir;
pub mod unhash;
pub mod unord;
pub use ena::undo_log;
pub use ena::unify;
/// Returns a structure that calls `f` when dropped.
pub fn defer<F: FnOnce()>(f: F) -> OnDrop<F> {
OnDrop(Some(f))
}
pub struct OnDrop<F: FnOnce()>(Option<F>);
impl<F: FnOnce()> OnDrop<F> {
/// Disables on-drop call.
#[inline]
pub fn disable(mut self) {
self.0.take();
}
}
impl<F: FnOnce()> Drop for OnDrop<F> {
#[inline]
fn drop(&mut self) {
if let Some(f) = self.0.take() {
f();
}
}
}
/// This is a marker for a fatal compiler error used with `resume_unwind`.
pub struct FatalErrorMarker;
/// Turns a closure that takes an `&mut Formatter` into something that can be display-formatted.
pub fn make_display(f: impl Fn(&mut fmt::Formatter<'_>) -> fmt::Result) -> impl fmt::Display {
struct Printer<F> {
f: F,
}
impl<F> fmt::Display for Printer<F>
where
F: Fn(&mut fmt::Formatter<'_>) -> fmt::Result,
{
fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
(self.f)(fmt)
}
}
Printer { f }
}
// See comment in compiler/rustc_middle/src/tests.rs and issue #27438.
#[doc(hidden)]
pub fn __noop_fix_for_windows_dllimport_issue() {}
#[macro_export]
macro_rules! external_bitflags_debug {
($Name:ident) => {
impl ::std::fmt::Debug for $Name {
fn fmt(&self, f: &mut ::std::fmt::Formatter<'_>) -> ::std::fmt::Result {
::bitflags::parser::to_writer(self, f)
}
}
};
}