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Fix compiler panic with a large number of threads

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This commit is contained in:
Michal Piotrowski 2024-10-30 12:31:26 +01:00
parent 16422dbd89
commit 7591eb60ad
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GPG Key ID: 2538DC6C8E7C7859
2 changed files with 12 additions and 3 deletions
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4
compiler/rustc_session/src/config.rs
View File

@ -2464,6 +2464,10 @@ pub fn build_session_options(early_dcx: &mut EarlyDiagCtxt, matches: &getopts::M
early_dcx.early_fatal("value for threads must be a positive non-zero integer");
}
if unstable_opts.threads == parse::MAX_THREADS_CAP {
early_dcx.early_warn(format!("number of threads was capped at {}", parse::MAX_THREADS_CAP));
}
let fuel = unstable_opts.fuel.is_some() || unstable_opts.print_fuel.is_some();
if fuel && unstable_opts.threads > 1 {
early_dcx.early_fatal("optimization fuel is incompatible with multiple threads");

11
compiler/rustc_session/src/options.rs
View File

@ -457,10 +457,11 @@ mod desc {
"either a boolean (`yes`, `no`, `on`, `off`, etc), or `nll` (default: `nll`)";
}
mod parse {
pub mod parse {
use std::str::FromStr;
pub(crate) use super::*;
pub(crate) const MAX_THREADS_CAP: usize = 256;
/// This is for boolean options that don't take a value and start with
/// `no-`. This style of option is deprecated.
@ -657,7 +658,7 @@ pub(crate) fn parse_opt_comma_list(slot: &mut Option<Vec<String>>, v: Option<&st
}
pub(crate) fn parse_threads(slot: &mut usize, v: Option<&str>) -> bool {
match v.and_then(|s| s.parse().ok()) {
let ret = match v.and_then(|s| s.parse().ok()) {
Some(0) => {
*slot = std::thread::available_parallelism().map_or(1, NonZero::<usize>::get);
true
@ -667,7 +668,11 @@ pub(crate) fn parse_threads(slot: &mut usize, v: Option<&str>) -> bool {
true
}
None => false,
}
};
// We want to cap the number of threads here to avoid large numbers like 999999 and compiler panics.
// This solution was suggested here https://github.com/rust-lang/rust/issues/117638#issuecomment-1800925067
*slot = slot.clone().min(MAX_THREADS_CAP);
ret
}
/// Use this for any numeric option that has a static default.