Change prefetch to avoid deadlock
Was abled to reproduce the deadlock in #118205 and created a coredump when it happen. When looking at the backtraces I noticed that the prefetch of exported_symbols (Thread 17 frame 4) started after the "actual" exported_symbols (Thread 2 frame 18) but it also is working on some of the collect_crate_mono_items (Thread 17 frame12 ) that Thread 2 is blocked on resulting in a deadlock.
This PR results in less parallell work that can be done at the same time but from what I can find we do not call the query exported_symbols from multiple places in the same join call any more.
```
Thread 17 (Thread 0x7f87b6299700 (LWP 11370)):
#0 syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
#1 0x00007f87be5166a9 in <parking_lot::condvar::Condvar>::wait_until_internal () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#2 0x00007f87be12d854 in <rustc_query_system::query::job::QueryLatch>::wait_on () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#3 0x00007f87bd27d16f in rustc_query_system::query::plumbing::try_execute_query::<rustc_query_impl::DynamicConfig<rustc_query_system::query::caches::VecCache<rustc_span::def_id::CrateNum, rustc_middle::query::erase::Erased<[u8; 16]>>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt, false> () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#4 0x00007f87bd0b5b6a in rustc_query_impl::query_impl::exported_symbols::get_query_non_incr::__rust_end_short_backtrace () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#5 0x00007f87bdaebb0a in rustc_metadata::rmeta::encoder::encode_metadata::{closure#1}::{closure#1} () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#6 0x00007f87bdae1509 in rayon_core::join::join_context::call_b::<core::option::Option<rustc_data_structures::marker::FromDyn<&[(rustc_middle::middle::exported_symbols::ExportedSymbol, rustc_middle::middle::exported_symbols::SymbolExportInfo)]>>, rayon_core::join::join::call<core::option::Option<rustc_data_structures::marker::FromDyn<&[(rustc_middle::middle::exported_symbols::ExportedSymbol, rustc_middle::middle::exported_symbols::SymbolExportInfo)]>>, rustc_data_structures::sync::parallel::enabled::join<rustc_metadata::rmeta::encoder::encode_metadata::{closure#1}::{closure#0}, rustc_metadata::rmeta::encoder::encode_metadata::{closure#1}::{closure#1}, (), &[(rustc_middle::middle::exported_symbols::ExportedSymbol, rustc_middle::middle::exported_symbols::SymbolExportInfo)]>::{closure#0}::{closure#1}>::{closure#0}>::{closure#0} () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#7 0x00007f87bdae32ff in <rayon_core::job::StackJob<rayon_core::latch::SpinLatch, rayon_core::join::join_context::call_b<core::option::Option<rustc_data_structures::marker::FromDyn<&[(rustc_middle::middle::exported_symbols::ExportedSymbol, rustc_middle::middle::exported_symbols::SymbolExportInfo)]>>, rayon_core::join::join::call<core::option::Option<rustc_data_structures::marker::FromDyn<&[(rustc_middle::middle::exported_symbols::ExportedSymbol, rustc_middle::middle::exported_symbols::SymbolExportInfo)]>>, rustc_data_structures::sync::parallel::enabled::join<rustc_metadata::rmeta::encoder::encode_metadata::{closure#1}::{closure#0}, rustc_metadata::rmeta::encoder::encode_metadata::{closure#1}::{closure#1}, (), &[(rustc_middle::middle::exported_symbols::ExportedSymbol, rustc_middle::middle::exported_symbols::SymbolExportInfo)]>::{closure#0}::{closure#1}>::{closure#0}>::{closure#0}, core::option::Option<rustc_data_structures::marker::FromDyn<&[(rustc_middle::middle::exported_symbols::ExportedSymbol, rustc_middle::middle::exported_symbols::SymbolExportInfo)]>>> as rayon_core::job::Job>::execute () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#8 0x00007f87b8338823 in <rayon_core::registry::WorkerThread>::wait_until_cold () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#9 0x00007f87bc2edbaf in rayon_core::join::join_context::<rayon::iter::plumbing::bridge_producer_consumer::helper<rayon::vec::DrainProducer<rustc_middle::mir::mono::MonoItem>, rayon::iter::for_each::ForEachConsumer<rustc_data_structures::sync::parallel::enabled::par_for_each_in<rustc_middle::mir::mono::MonoItem, alloc::vec::Vec<rustc_middle::mir::mono::MonoItem>, rustc_monomorphize::collector::collect_crate_mono_items::{closure#1}::{closure#0}>::{closure#0}::{closure#0}>>::{closure#0}, rayon::iter::plumbing::bridge_producer_consumer::helper<rayon::vec::DrainProducer<rustc_middle::mir::mono::MonoItem>, rayon::iter::for_each::ForEachConsumer<rustc_data_structures::sync::parallel::enabled::par_for_each_in<rustc_middle::mir::mono::MonoItem, alloc::vec::Vec<rustc_middle::mir::mono::MonoItem>, rustc_monomorphize::collector::collect_crate_mono_items::{closure#1}::{closure#0}>::{closure#0}::{closure#0}>>::{closure#1}, (), ()>::{closure#0} () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#10 0x00007f87bc2ed313 in rayon_core::registry::in_worker::<rayon_core::join::join_context<rayon::iter::plumbing::bridge_producer_consumer::helper<rayon::vec::DrainProducer<rustc_middle::mir::mono::MonoItem>, rayon::iter::for_each::ForEachConsumer<rustc_data_structures::sync::parallel::enabled::par_for_each_in<rustc_middle::mir::mono::MonoItem, alloc::vec::Vec<rustc_middle::mir::mono::MonoItem>, rustc_monomorphize::collector::collect_crate_mono_items::{closure#1}::{closure#0}>::{closure#0}::{closure#0}>>::{closure#0}, rayon::iter::plumbing::bridge_producer_consumer::helper<rayon::vec::DrainProducer<rustc_middle::mir::mono::MonoItem>, rayon::iter::for_each::ForEachConsumer<rustc_data_structures::sync::parallel::enabled::par_for_each_in<rustc_middle::mir::mono::MonoItem, alloc::vec::Vec<rustc_middle::mir::mono::MonoItem>, rustc_monomorphize::collector::collect_crate_mono_items::{closure#1}::{closure#0}>::{closure#0}::{closure#0}>>::{closure#1}, (), ()>::{closure#0}, ((), ())> () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#11 0x00007f87bc2db2a4 in rayon::iter::plumbing::bridge_producer_consumer::helper::<rayon::vec::DrainProducer<rustc_middle::mir::mono::MonoItem>, rayon::iter::for_each::ForEachConsumer<rustc_data_structures::sync::parallel::enabled::par_for_each_in<rustc_middle::mir::mono::MonoItem, alloc::vec::Vec<rustc_middle::mir::mono::MonoItem>, rustc_monomorphize::collector::collect_crate_mono_items::{closure#1}::{closure#0}>::{closure#0}::{closure#0}>> () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#12 0x00007f87bc2eead2 in <rayon_core::job::StackJob<rayon_core::latch::SpinLatch, rayon_core::join::join_context::call_b<(), rayon::iter::plumbing::bridge_producer_consumer::helper<rayon::vec::DrainProducer<rustc_middle::mir::mono::MonoItem>, rayon::iter::for_each::ForEachConsumer<rustc_data_structures::sync::parallel::enabled::par_for_each_in<rustc_middle::mir::mono::MonoItem, alloc::vec::Vec<rustc_middle::mir::mono::MonoItem>, rustc_monomorphize::collector::collect_crate_mono_items::{closure#1}::{closure#0}>::{closure#0}::{closure#0}>>::{closure#1}>::{closure#0}, ()> as rayon_core::job::Job>::execute () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#13 0x00007f87b8338823 in <rayon_core::registry::WorkerThread>::wait_until_cold () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#14 0x00007f87be52d1f9 in <rayon_core::registry::ThreadBuilder>::run () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#15 0x00007f87b8461c57 in <scoped_tls::ScopedKey<rustc_span::SessionGlobals>>::set::<rustc_interface::util::run_in_thread_pool_with_globals<rustc_interface::interface::run_compiler<core::result::Result<(), rustc_span::ErrorGuaranteed>, rustc_driver_impl::run_compiler::{closure#0}>::{closure#0}, core::result::Result<(), rustc_span::ErrorGuaranteed>>::{closure#3}::{closure#0}::{closure#0}::{closure#0}, ()> () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#16 0x00007f87b846e465 in rustc_span::set_session_globals_then::<(), rustc_interface::util::run_in_thread_pool_with_globals<rustc_interface::interface::run_compiler<core::result::Result<(), rustc_span::ErrorGuaranteed>, rustc_driver_impl::run_compiler::{closure#0}>::{closure#0}, core::result::Result<(), rustc_span::ErrorGuaranteed>>::{closure#3}::{closure#0}::{closure#0}::{closure#0}> () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#17 0x00007f87b844f282 in <<crossbeam_utils:🧵:ScopedThreadBuilder>::spawn<<rayon_core::ThreadPoolBuilder>::build_scoped<rustc_interface::util::run_in_thread_pool_with_globals<rustc_interface::interface::run_compiler<core::result::Result<(), rustc_span::ErrorGuaranteed>, rustc_driver_impl::run_compiler::{closure#0}>::{closure#0}, core::result::Result<(), rustc_span::ErrorGuaranteed>>::{closure#3}::{closure#0}::{closure#0}, rustc_interface::util::run_in_thread_pool_with_globals<rustc_interface::interface::run_compiler<core::result::Result<(), rustc_span::ErrorGuaranteed>, rustc_driver_impl::run_compiler::{closure#0}>::{closure#0}, core::result::Result<(), rustc_span::ErrorGuaranteed>>::{closure#3}::{closure#0}::{closure#1}, core::result::Result<(), rustc_span::ErrorGuaranteed>>::{closure#0}::{closure#0}::{closure#0}, ()>::{closure#0} as core::ops::function::FnOnce<()>>::call_once::{shim:vtable#0} () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#18 0x00007f87b846af58 in <<std:🧵:Builder>::spawn_unchecked_<alloc::boxed::Box<dyn core::ops::function::FnOnce<(), Output = ()> + core::marker::Send>, ()>::{closure#1} as core::ops::function::FnOnce<()>>::call_once::{shim:vtable#0} () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#19 0x00007f87b7898e85 in std::sys::unix:🧵:Thread:🆕:thread_start () from /home/andjo403/.rustup/toolchains/stage1/lib/libstd-d570b0650d35d951.so
#20 0x00007f87b7615609 in start_thread (arg=<optimized out>) at pthread_create.c:477
#21 0x00007f87b7755133 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95
Thread 2 (Thread 0x7f87b729b700 (LWP 11368)):
#0 syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
#1 0x00007f87b7887b51 in std::sys::unix::locks::futex_condvar::Condvar::wait () from /home/andjo403/.rustup/toolchains/stage1/lib/libstd-d570b0650d35d951.so
#2 0x00007f87b8339478 in <rayon_core::sleep::Sleep>::sleep () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#3 0x00007f87b83387c3 in <rayon_core::registry::WorkerThread>::wait_until_cold () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#4 0x00007f87bc2edbaf in rayon_core::join::join_context::<rayon::iter::plumbing::bridge_producer_consumer::helper<rayon::vec::DrainProducer<rustc_middle::mir::mono::MonoItem>, rayon::iter::for_each::ForEachConsumer<rustc_data_structures::sync::parallel::enabled::par_for_each_in<rustc_middle::mir::mono::MonoItem, alloc::vec::Vec<rustc_middle::mir::mono::MonoItem>, rustc_monomorphize::collector::collect_crate_mono_items::{closure#1}::{closure#0}>::{closure#0}::{closure#0}>>::{closure#0}, rayon::iter::plumbing::bridge_producer_consumer::helper<rayon::vec::DrainProducer<rustc_middle::mir::mono::MonoItem>, rayon::iter::for_each::ForEachConsumer<rustc_data_structures::sync::parallel::enabled::par_for_each_in<rustc_middle::mir::mono::MonoItem, alloc::vec::Vec<rustc_middle::mir::mono::MonoItem>, rustc_monomorphize::collector::collect_crate_mono_items::{closure#1}::{closure#0}>::{closure#0}::{closure#0}>>::{closure#1}, (), ()>::{closure#0} () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#5 0x00007f87bc2ed313 in rayon_core::registry::in_worker::<rayon_core::join::join_context<rayon::iter::plumbing::bridge_producer_consumer::helper<rayon::vec::DrainProducer<rustc_middle::mir::mono::MonoItem>, rayon::iter::for_each::ForEachConsumer<rustc_data_structures::sync::parallel::enabled::par_for_each_in<rustc_middle::mir::mono::MonoItem, alloc::vec::Vec<rustc_middle::mir::mono::MonoItem>, rustc_monomorphize::collector::collect_crate_mono_items::{closure#1}::{closure#0}>::{closure#0}::{closure#0}>>::{closure#0}, rayon::iter::plumbing::bridge_producer_consumer::helper<rayon::vec::DrainProducer<rustc_middle::mir::mono::MonoItem>, rayon::iter::for_each::ForEachConsumer<rustc_data_structures::sync::parallel::enabled::par_for_each_in<rustc_middle::mir::mono::MonoItem, alloc::vec::Vec<rustc_middle::mir::mono::MonoItem>, rustc_monomorphize::collector::collect_crate_mono_items::{closure#1}::{closure#0}>::{closure#0}::{closure#0}>>::{closure#1}, (), ()>::{closure#0}, ((), ())> () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#6 0x00007f87bc2db50c in <rayon::vec::IntoIter<rustc_middle::mir::mono::MonoItem> as rayon::iter::ParallelIterator>::for_each::<rustc_data_structures::sync::parallel::enabled::par_for_each_in<rustc_middle::mir::mono::MonoItem, alloc::vec::Vec<rustc_middle::mir::mono::MonoItem>, rustc_monomorphize::collector::collect_crate_mono_items::{closure#1}::{closure#0}>::{closure#0}::{closure#0}> () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#7 0x00007f87bc2e8cd7 in <rustc_session::session::Session>::time::<(), rustc_monomorphize::collector::collect_crate_mono_items::{closure#1}> () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#8 0x00007f87bc2b8f2c in rustc_monomorphize::collector::collect_crate_mono_items () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#9 0x00007f87bc2c30d9 in rustc_monomorphize::partitioning::collect_and_partition_mono_items () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#10 0x00007f87bcf2cde6 in rustc_query_impl::plumbing::__rust_begin_short_backtrace::<rustc_query_impl::query_impl::collect_and_partition_mono_items::dynamic_query::{closure#2}::{closure#0}, rustc_middle::query::erase::Erased<[u8; 24]>> () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#11 0x00007f87bd156a3c in <rustc_query_impl::query_impl::collect_and_partition_mono_items::dynamic_query::{closure#2} as core::ops::function::FnOnce<(rustc_middle::ty::context::TyCtxt, ())>>::call_once () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#12 0x00007f87bd1c6a7d in rustc_query_system::query::plumbing::try_execute_query::<rustc_query_impl::DynamicConfig<rustc_query_system::query::caches::SingleCache<rustc_middle::query::erase::Erased<[u8; 24]>>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt, false> () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#13 0x00007f87bd15df40 in rustc_query_impl::query_impl::collect_and_partition_mono_items::get_query_non_incr::__rust_end_short_backtrace () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#14 0x00007f87bd7a0ad9 in rustc_codegen_ssa:🔙:symbol_export::exported_symbols_provider_local () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#15 0x00007f87bcf29acb in rustc_query_impl::plumbing::__rust_begin_short_backtrace::<rustc_query_impl::query_impl::exported_symbols::dynamic_query::{closure#2}::{closure#0}, rustc_middle::query::erase::Erased<[u8; 16]>> () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#16 0x00007f87bcfdb350 in <rustc_query_impl::query_impl::exported_symbols::dynamic_query::{closure#2} as core::ops::function::FnOnce<(rustc_middle::ty::context::TyCtxt, rustc_span::def_id::CrateNum)>>::call_once () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#17 0x00007f87bd27d64f in rustc_query_system::query::plumbing::try_execute_query::<rustc_query_impl::DynamicConfig<rustc_query_system::query::caches::VecCache<rustc_span::def_id::CrateNum, rustc_middle::query::erase::Erased<[u8; 16]>>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt, false> () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#18 0x00007f87bd0b5b6a in rustc_query_impl::query_impl::exported_symbols::get_query_non_incr::__rust_end_short_backtrace () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#19 0x00007f87bda927ce in rustc_middle::query::plumbing::query_get_at::<rustc_query_system::query::caches::VecCache<rustc_span::def_id::CrateNum, rustc_middle::query::erase::Erased<[u8; 16]>>> () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#20 0x00007f87bda9c93f in <rustc_metadata::rmeta::encoder::EncodeContext>::encode_crate_root () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#21 0x00007f87bdaa6ef7 in rustc_metadata::rmeta::encoder::encode_metadata_impl () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#22 0x00007f87bdae0b77 in rayon_core::join::join_context::<rayon_core::join::join::call<core::option::Option<rustc_data_structures::marker::FromDyn<()>>, rustc_data_structures::sync::parallel::enabled::join<rustc_metadata::rmeta::encoder::encode_metadata::{closure#0}, rustc_metadata::rmeta::encoder::encode_metadata::{closure#1}, (), ()>::{closure#0}::{closure#0}>::{closure#0}, rayon_core::join::join::call<core::option::Option<rustc_data_structures::marker::FromDyn<()>>, rustc_data_structures::sync::parallel::enabled::join<rustc_metadata::rmeta::encoder::encode_metadata::{closure#0}, rustc_metadata::rmeta::encoder::encode_metadata::{closure#1}, (), ()>::{closure#0}::{closure#1}>::{closure#0}, core::option::Option<rustc_data_structures::marker::FromDyn<()>>, core::option::Option<rustc_data_structures::marker::FromDyn<()>>>::{closure#0} () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#23 0x00007f87bdaded2f in rayon_core::registry::in_worker::<rayon_core::join::join_context<rayon_core::join::join::call<core::option::Option<rustc_data_structures::marker::FromDyn<()>>, rustc_data_structures::sync::parallel::enabled::join<rustc_metadata::rmeta::encoder::encode_metadata::{closure#0}, rustc_metadata::rmeta::encoder::encode_metadata::{closure#1}, (), ()>::{closure#0}::{closure#0}>::{closure#0}, rayon_core::join::join::call<core::option::Option<rustc_data_structures::marker::FromDyn<()>>, rustc_data_structures::sync::parallel::enabled::join<rustc_metadata::rmeta::encoder::encode_metadata::{closure#0}, rustc_metadata::rmeta::encoder::encode_metadata::{closure#1}, (), ()>::{closure#0}::{closure#1}>::{closure#0}, core::option::Option<rustc_data_structures::marker::FromDyn<()>>, core::option::Option<rustc_data_structures::marker::FromDyn<()>>>::{closure#0}, (core::option::Option<rustc_data_structures::marker::FromDyn<()>>, core::option::Option<rustc_data_structures::marker::FromDyn<()>>)> () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#24 0x00007f87bdaa5a03 in rustc_metadata::rmeta::encoder::encode_metadata () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#25 0x00007f87bdaed628 in rustc_metadata::fs::encode_and_write_metadata () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#26 0x00007f87b86608be in rustc_interface::passes::start_codegen () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#27 0x00007f87b8664946 in <rustc_middle::ty::context::GlobalCtxt>::enter::<<rustc_interface::queries::Queries>::codegen_and_build_linker::{closure#0}, core::result::Result<rustc_interface::queries::Linker, rustc_span::ErrorGuaranteed>> () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#28 0x00007f87b864db00 in <rustc_interface::queries::Queries>::codegen_and_build_linker () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#29 0x00007f87b849400f in <rustc_interface::interface::Compiler>::enter::<rustc_driver_impl::run_compiler::{closure#0}::{closure#0}, core::result::Result<core::option::Option<rustc_interface::queries::Linker>, rustc_span::ErrorGuaranteed>> () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#30 0x00007f87b846e067 in rustc_span::set_source_map::<core::result::Result<(), rustc_span::ErrorGuaranteed>, rustc_interface::interface::run_compiler<core::result::Result<(), rustc_span::ErrorGuaranteed>, rustc_driver_impl::run_compiler::{closure#0}>::{closure#0}::{closure#0}> () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#31 0x00007f87b844dc13 in <rayon_core::thread_pool::ThreadPool>::install::<rustc_interface::interface::run_compiler<core::result::Result<(), rustc_span::ErrorGuaranteed>, rustc_driver_impl::run_compiler::{closure#0}>::{closure#0}, core::result::Result<(), rustc_span::ErrorGuaranteed>>::{closure#0} () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#32 0x00007f87b84509a1 in <rayon_core::job::StackJob<rayon_core::latch::LatchRef<rayon_core::latch::LockLatch>, <rayon_core::registry::Registry>::in_worker_cold<<rayon_core::thread_pool::ThreadPool>::install<rustc_interface::interface::run_compiler<core::result::Result<(), rustc_span::ErrorGuaranteed>, rustc_driver_impl::run_compiler::{closure#0}>::{closure#0}, core::result::Result<(), rustc_span::ErrorGuaranteed>>::{closure#0}, core::result::Result<(), rustc_span::ErrorGuaranteed>>::{closure#0}::{closure#0}, core::result::Result<(), rustc_span::ErrorGuaranteed>> as rayon_core::job::Job>::execute () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#33 0x00007f87b8338823 in <rayon_core::registry::WorkerThread>::wait_until_cold () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#34 0x00007f87be52d1f9 in <rayon_core::registry::ThreadBuilder>::run () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#35 0x00007f87b8461c57 in <scoped_tls::ScopedKey<rustc_span::SessionGlobals>>::set::<rustc_interface::util::run_in_thread_pool_with_globals<rustc_interface::interface::run_compiler<core::result::Result<(), rustc_span::ErrorGuaranteed>, rustc_driver_impl::run_compiler::{closure#0}>::{closure#0}, core::result::Result<(), rustc_span::ErrorGuaranteed>>::{closure#3}::{closure#0}::{closure#0}::{closure#0}, ()> () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#36 0x00007f87b846e465 in rustc_span::set_session_globals_then::<(), rustc_interface::util::run_in_thread_pool_with_globals<rustc_interface::interface::run_compiler<core::result::Result<(), rustc_span::ErrorGuaranteed>, rustc_driver_impl::run_compiler::{closure#0}>::{closure#0}, core::result::Result<(), rustc_span::ErrorGuaranteed>>::{closure#3}::{closure#0}::{closure#0}::{closure#0}> () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#37 0x00007f87b844f282 in <<crossbeam_utils:🧵:ScopedThreadBuilder>::spawn<<rayon_core::ThreadPoolBuilder>::build_scoped<rustc_interface::util::run_in_thread_pool_with_globals<rustc_interface::interface::run_compiler<core::result::Result<(), rustc_span::ErrorGuaranteed>, rustc_driver_impl::run_compiler::{closure#0}>::{closure#0}, core::result::Result<(), rustc_span::ErrorGuaranteed>>::{closure#3}::{closure#0}::{closure#0}, rustc_interface::util::run_in_thread_pool_with_globals<rustc_interface::interface::run_compiler<core::result::Result<(), rustc_span::ErrorGuaranteed>, rustc_driver_impl::run_compiler::{closure#0}>::{closure#0}, core::result::Result<(), rustc_span::ErrorGuaranteed>>::{closure#3}::{closure#0}::{closure#1}, core::result::Result<(), rustc_span::ErrorGuaranteed>>::{closure#0}::{closure#0}::{closure#0}, ()>::{closure#0} as core::ops::function::FnOnce<()>>::call_once::{shim:vtable#0} () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#38 0x00007f87b846af58 in <<std:🧵:Builder>::spawn_unchecked_<alloc::boxed::Box<dyn core::ops::function::FnOnce<(), Output = ()> + core::marker::Send>, ()>::{closure#1} as core::ops::function::FnOnce<()>>::call_once::{shim:vtable#0} () from /home/andjo403/.rustup/toolchains/stage1/lib/librustc_driver-70ddb84e8f7ce707.so
#39 0x00007f87b7898e85 in std::sys::unix:🧵:Thread:🆕:thread_start () from /home/andjo403/.rustup/toolchains/stage1/lib/libstd-d570b0650d35d951.so
#40 0x00007f87b7615609 in start_thread (arg=<optimized out>) at pthread_create.c:477
#41 0x00007f87b7755133 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95
```
fixes#118205fixes#117759 from the latest logs it is the same query map as in #118205fixes#118529fixes#117784
cc #118206
r? `@SparrowLii`
They're not used in `rustc_session`, and `rustc_metadata` is a more
obvious location.
`MetadataLoader` was originally put into `rustc_session` in #41565 to
avoid a dependency on LLVM, but things have changed a lot since then and
that's no longer relevant, e.g. `rustc_codegen_llvm` depends on
`rustc_metadata`.
Call FileEncoder::finish in rmeta encoding
Fixes https://github.com/rust-lang/rust/issues/117254
The bug here was that rmeta encoding never called FileEncoder::finish. Now it does. Most of the changes here are needed to support that, since rmeta encoding wants to finish _then_ access the File in the encoder, so finish can't move out.
I tried adding a `cfg(debug_assertions)` exploding Drop impl to FileEncoder that checked for finish being called before dropping, but fatal errors cause unwinding so this isn't really possible. If we encounter a fatal error with a dirty FileEncoder, the Drop impl ICEs even though the implementation is correct. If we try to paper over that by wrapping FileEncoder in ManuallyDrop then that just erases the fact that Drop automatically checks that we call finish on all paths.
I also changed the name of DepGraph::encode to DepGraph::finish_encoding, because that's what it does and it makes the fact that it is the path to FileEncoder::finish less confusing.
r? `@WaffleLapkin`
Currently we always do this:
```
use rustc_fluent_macro::fluent_messages;
...
fluent_messages! { "./example.ftl" }
```
But there is no need, we can just do this everywhere:
```
rustc_fluent_macro::fluent_messages! { "./example.ftl" }
```
which is shorter.
The `fluent_messages!` macro produces uses of
`crate::{D,Subd}iagnosticMessage`, which means that every crate using
the macro must have this import:
```
use rustc_errors::{DiagnosticMessage, SubdiagnosticMessage};
```
This commit changes the macro to instead use
`rustc_errors::{D,Subd}iagnosticMessage`, which avoids the need for the
imports.
They've been deprecated for four years.
This commit includes the following changes.
- It eliminates the `rustc_plugin_impl` crate.
- It changes the language used for lints in
`compiler/rustc_driver_impl/src/lib.rs` and
`compiler/rustc_lint/src/context.rs`. External lints are now called
"loaded" lints, rather than "plugins" to avoid confusion with the old
plugins. This only has a tiny effect on the output of `-W help`.
- E0457 and E0498 are no longer used.
- E0463 is narrowed, now only relating to unfound crates, not plugins.
- The `plugin` feature was moved from "active" to "removed".
- It removes the entire plugins chapter from the unstable book.
- It removes quite a few tests, mostly all of those in
`tests/ui-fulldeps/plugin/`.
Closes#29597.
- Sort dependencies and features sections.
- Add `tidy` markers to the sorted sections so they stay sorted.
- Remove empty `[lib`] sections.
- Remove "See more keys..." comments.
Excluded files:
- rustc_codegen_{cranelift,gcc}, because they're external.
- rustc_lexer, because it has external use.
- stable_mir, because it has external use.
Implement rustc part of RFC 3127 trim-paths
This PR implements (or at least tries to) [RFC 3127 trim-paths](https://github.com/rust-lang/rust/issues/111540), the rustc part. That is `-Zremap-path-scope` with all of it's components/scopes.
`@rustbot` label: +F-trim-paths
Move `DepKind` to `rustc_query_system` and define it as `u16`
This moves the `DepKind` type to `rustc_query_system` where it's defined with an inner `u16` field. This decouples it from `rustc_middle` and is a step towards letting other crates define dep kinds. It also allows some type parameters to be removed. The `DepKind` trait is replaced with a `Deps` trait. That's used when some operations or information about dep kinds which is unavailable in `rustc_query_system` are still needed.
r? `@cjgillot`
Simplify/Optimize FileEncoder
FileEncoder is basically a BufWriter except that it exposes access to the not-written-to-yet region of the buffer so that some users can write directly to the buffer. This strategy is awesome because it lets us avoid calling memcpy for small copies, but the previous strategy was based on the writer accessing a `&mut [MaybeUninit<u8>; N]` and returning a `&[u8]` which is an API which currently mandates the use of unsafe code, making that interface in general not that appealing.
So this PR cleans up the FileEncoder implementation and builds on that general idea of direct buffer access in order to prevent `memcpy` calls in a few key places when encoding the dep graph and rmeta tables. The interface used here is now 100% safe, but with the caveat that internally we need to avoid trusting the number of bytes that the provided function claims to have written.
The original primary objective of this PR was to clean up the FileEncoder implementation so that the fix for the following issues would be easy to implement. The fix for these issues is to correctly update self.buffered even when writes fail, which I think it's easy to verify manually is now done, because all the FileEncoder methods are small.
Fixes https://github.com/rust-lang/rust/issues/115298
Fixes https://github.com/rust-lang/rust/issues/114671
Fixes https://github.com/rust-lang/rust/issues/114045
Fixes https://github.com/rust-lang/rust/issues/108100
Fixes https://github.com/rust-lang/rust/issues/106787
Make `.rmeta` file in `dep-info` have correct name (`lib` prefix)
Since `filename_for_metadata()` and
`OutputFilenames::path(OutputType::Metadata)` had different logic for the name of the metadata file, the `.d` file contained a file name different from the actual name used. Share the logic to fix the out-of-sync name.
Without this fix, the `.d` file contained
dash-separated_something-extra.rmeta: dash-separated.rs
instead of
libdash_separated_something-extra.rmeta: dash-separated.rs
which is the name of the file that is actually written by the compiler.
Worth noting: It took me several iterations to get all tests to pass, so I am relatively confident that this PR does not break anything.
Closes#68839
Encode only MIR reachable from other crates
Only reachable items might participate in the code generation in the
downstream crates. Omit redundant optimized MIR of unreachable items
from a crate metadata.
Additionally, include reachable closures in reachable set, so that
unreachable closures can be omitted on the same basis.
