Add -Z no-parallel-llvm flag

Codegen issues commonly only manifest under specific circumstances,
e.g. if multiple codegen units are used and ThinLTO is enabled.
However, these configuration are threaded, making the use of LLVM
debugging facilities hard, as output is interleaved.

This patch adds a -Z no-parallel-llvm flag, which allows disabling
parallelization of codegen and linking, while otherwise preserving
behavior with regard to codegen units and LTO.
This commit is contained in:
Nikita Popov 2018-05-22 19:23:40 +02:00
parent 9f80ea3281
commit 54f0668a10
2 changed files with 8 additions and 2 deletions

View file

@ -1337,6 +1337,8 @@ options! {DebuggingOptions, DebuggingSetter, basic_debugging_options,
"enable the experimental Chalk-based trait solving engine"),
cross_lang_lto: CrossLangLto = (CrossLangLto::Disabled, parse_cross_lang_lto, [TRACKED],
"generate build artifacts that are compatible with linker-based LTO."),
no_parallel_llvm: bool = (false, parse_bool, [UNTRACKED],
"don't run LLVM in parallel (while keeping codegen-units and ThinLTO)"),
}
pub fn default_lib_output() -> CrateType {

View file

@ -1738,7 +1738,9 @@ fn start_executing_work(tcx: TyCtxt,
.binary_search_by_key(&cost, |&(_, cost)| cost)
.unwrap_or_else(|e| e);
work_items.insert(insertion_index, (work, cost));
helper.request_token();
if !cgcx.opts.debugging_opts.no_parallel_llvm {
helper.request_token();
}
}
}
@ -1842,7 +1844,9 @@ fn start_executing_work(tcx: TyCtxt,
};
work_items.insert(insertion_index, (llvm_work_item, cost));
helper.request_token();
if !cgcx.opts.debugging_opts.no_parallel_llvm {
helper.request_token();
}
assert_eq!(main_thread_worker_state,
MainThreadWorkerState::Codegenning);
main_thread_worker_state = MainThreadWorkerState::Idle;