diff --git a/compiler/rustc_driver_impl/src/signal_handler.rs b/compiler/rustc_driver_impl/src/signal_handler.rs index deca108222150..441219eec90dc 100644 --- a/compiler/rustc_driver_impl/src/signal_handler.rs +++ b/compiler/rustc_driver_impl/src/signal_handler.rs @@ -1,6 +1,7 @@ //! Signal handler for rustc //! Primarily used to extract a backtrace from stack overflow +use rustc_interface::util::{DEFAULT_STACK_SIZE, STACK_SIZE}; use std::alloc::{alloc, Layout}; use std::{fmt, mem, ptr}; @@ -100,7 +101,10 @@ extern "C" fn print_stack_trace(_: libc::c_int) { written += 1; } raw_errln!("note: we would appreciate a report at https://github.com/rust-lang/rust"); - written += 1; + // get the current stack size WITHOUT blocking and double it + let new_size = STACK_SIZE.get().copied().unwrap_or(DEFAULT_STACK_SIZE) * 2; + raw_errln!("help: you can increase rustc's stack size by setting RUST_MIN_STACK={new_size}"); + written += 2; if written > 24 { // We probably just scrolled the earlier "we got SIGSEGV" message off the terminal raw_errln!("note: backtrace dumped due to SIGSEGV! resuming signal"); diff --git a/compiler/rustc_interface/src/util.rs b/compiler/rustc_interface/src/util.rs index 7d48f90db3625..d09f8d7d7cf75 100644 --- a/compiler/rustc_interface/src/util.rs +++ b/compiler/rustc_interface/src/util.rs @@ -48,12 +48,20 @@ pub fn add_configuration(cfg: &mut Cfg, sess: &mut Session, codegen_backend: &dy } } -const STACK_SIZE: usize = 8 * 1024 * 1024; - -fn get_stack_size() -> Option { - // FIXME: Hacks on hacks. If the env is trying to override the stack size - // then *don't* set it explicitly. - env::var_os("RUST_MIN_STACK").is_none().then_some(STACK_SIZE) +pub static STACK_SIZE: OnceLock = OnceLock::new(); +pub const DEFAULT_STACK_SIZE: usize = 8 * 1024 * 1024; + +fn init_stack_size() -> usize { + // Obey the environment setting or default + *STACK_SIZE.get_or_init(|| { + env::var_os("RUST_MIN_STACK") + .map(|os_str| os_str.to_string_lossy().into_owned()) + // ignore if it is set to nothing + .filter(|s| s.trim() != "") + .map(|s| s.trim().parse::().unwrap()) + // otherwise pick a consistent default + .unwrap_or(DEFAULT_STACK_SIZE) + }) } pub(crate) fn run_in_thread_with_globals R + Send, R: Send>( @@ -66,10 +74,7 @@ pub(crate) fn run_in_thread_with_globals R + Send, R: Send>( // the parallel compiler, in particular to ensure there is no accidental // sharing of data between the main thread and the compilation thread // (which might cause problems for the parallel compiler). - let mut builder = thread::Builder::new().name("rustc".to_string()); - if let Some(size) = get_stack_size() { - builder = builder.stack_size(size); - } + let builder = thread::Builder::new().name("rustc".to_string()).stack_size(init_stack_size()); // We build the session globals and run `f` on the spawned thread, because // `SessionGlobals` does not impl `Send` in the non-parallel compiler. @@ -120,7 +125,7 @@ pub(crate) fn run_in_thread_pool_with_globals R + Send, R: Send>( }); } - let mut builder = rayon::ThreadPoolBuilder::new() + let builder = rayon::ThreadPoolBuilder::new() .thread_name(|_| "rustc".to_string()) .acquire_thread_handler(jobserver::acquire_thread) .release_thread_handler(jobserver::release_thread) @@ -144,10 +149,8 @@ pub(crate) fn run_in_thread_pool_with_globals R + Send, R: Send>( on_panic.disable(); }) .unwrap(); - }); - if let Some(size) = get_stack_size() { - builder = builder.stack_size(size); - } + }) + .stack_size(init_stack_size()); // We create the session globals on the main thread, then create the thread // pool. Upon creation, each worker thread created gets a copy of the