submodules: update clippy from 3710ec59 to ad3269c4

[matthiaskrgr]

Changes:

Rustfmt all the things Clippy dogfood Update for compiletest changes Use symbols instead of strings Rustup to rustc 1.36.0-nightly (1764b2972 2019-05-12) Add regression test for identity_conversion FP UI test cleanup: Extract many_single_char_names tests Add tests for empty_loop lint Add in_macro again Rename in_macro to in_macro_or_desugar 

r? @oli-obk

[rust-highfive]

⚠️ Warning ⚠️

• These commits modify submodules.

[oli-obk]

@bors r+ p=1

[bors]

📌 Commit 41184aa has been approved by oli-obk

[ehuss]

After this PR, rls's tests seem to fail with an ICE in rustc:

backtrace

thread 'rustc' panicked at 'index out of bounds: the len is 2 but the index is 4294954756', /rustc/a9ec99f4201ec33026a468ef1289f98a95b4d71a/src/libcore/slice/mod.rs:2689:10 stack backtrace: 0: std::sys::unix::backtrace::tracing::imp::unwind_backtrace 1: std::sys_common::backtrace::_print 2: std::panicking::default_hook::{{closure}} 3: std::panicking::default_hook 4: rustc::util::common::panic_hook 5: std::panicking::rust_panic_with_hook 6: std::panicking::continue_panic_fmt 7: rust_begin_unwind 8: core::panicking::panic_fmt 9: core::panicking::panic_bounds_check 10: scoped_tls::ScopedKey::with 11: syntax_pos::symbol::Symbol::as_str 12: clippy_lints::utils::match_def_path::{{closure}} at /Users/eric/.cargo/git/checkouts/rust-clippy-4b72815e96774b3d/ad3269c/clippy_lints/src/utils/mod.rs:1122 13: ::eq at /rustc/a9ec99f4201ec33026a468ef1289f98a95b4d71a/src/libcore/iter/adapters/mod.rs:589 14: clippy_lints::utils::conf::helpers::doc_valid_idents::{{closure}} at /rustc/a9ec99f4201ec33026a468ef1289f98a95b4d71a/src/libcore/slice/mod.rs:3153 15: ::eq at /rustc/a9ec99f4201ec33026a468ef1289f98a95b4d71a/src/libcore/iter/adapters/mod.rs:589 16: std::sys_common::poison::Flag::borrow at /rustc/a9ec99f4201ec33026a468ef1289f98a95b4d71a/src/libcore/iter/traits/iterator.rs:604 17: ::drop at /rustc/a9ec99f4201ec33026a468ef1289f98a95b4d71a/src/liballoc/vec.rs:1862 18: ::drop at /rustc/a9ec99f4201ec33026a468ef1289f98a95b4d71a/src/liballoc/vec.rs:1845 19: ::drop at /rustc/a9ec99f4201ec33026a468ef1289f98a95b4d71a/src/liballoc/vec.rs:1731 20: std::sys_common::poison::Flag::borrow at /rustc/a9ec99f4201ec33026a468ef1289f98a95b4d71a/src/libcore/iter/traits/iterator.rs:1465 21: clippy_lints::utils::match_def_path at /Users/eric/.cargo/git/checkouts/rust-clippy-4b72815e96774b3d/ad3269c/clippy_lints/src/utils/mod.rs:1122 22: ::check_block_post::{{closure}} at /Users/eric/.cargo/git/checkouts/rust-clippy-4b72815e96774b3d/ad3269c/clippy_lints/src/regex.rs:116 23: ::check_expr 24: as rustc::hir::intravisit::Visitor>::visit_expr 25: rustc::hir::intravisit::walk_expr 26: as rustc::hir::intravisit::Visitor>::visit_expr 27: rustc::hir::intravisit::walk_fn 28: rustc::hir::intravisit::walk_item 29: rustc::hir::intravisit::Visitor::visit_nested_item 30: rustc::hir::intravisit::walk_crate 31: rustc::lint::context::late_lint_pass_crate 32: rustc::lint::context::late_lint_crate 33: rustc::util::common::time 34: rustc::util::common::time 35: __rust_maybe_catch_panic 36: as core::ops::function::FnOnce<()>>::call_once 37: __rust_maybe_catch_panic 38: rustc_interface::passes::analysis::{{closure}} 39: rustc::util::common::time 40: rustc_interface::passes::analysis 41: rustc::ty::query::__query_compute::analysis 42: rustc::ty::query::::compute 43: rustc::dep_graph::graph::DepGraph::with_task_impl 44: rustc::ty::query::plumbing::::get_query 45: rustc::ty::context::tls::enter_global 46: rustc_interface::passes::BoxedGlobalCtxt::access::{{closure}} 47: rustc_interface::passes::create_global_ctxt::{{closure}} 48: rustc_interface::interface::run_compiler_in_existing_thread_pool 49: std::thread::local::LocalKey::with 50: scoped_tls::ScopedKey::set 51: syntax::with_globals 

Is there anyone around who can help me debug it? For context, I would like to update cargo before beta, which will require updating rls, which will require getting rls working. cc @Xanewok

Also cc @Manishearth who looks like did the PR to update Symbol handling in clippy. There something fishy with the getting the interned string for a Symbol. I know very little about clippy, rustc, and rls, so I don't think I'll be able to make much progress.

Reproducing is fairly easy. Check out rls, change the clippy hash in Cargo.toml to the latest clippy, build with latest nightly. Create a cargo project with an empty lib.rs, and main.rs with fn main() {}. Run rls --cli, and it should crash with the above stack trace inside clippy match_def_path.

[Manishearth]

cc @oli-obk , i didn't really do that part of the PR (just the mechanical bits)

[Manishearth]

The backtrace doesn't make sense, there are no expressions in fn main() {}.

It's possible that the Symbol stuff broke some assumptions in RLS as well, and they need to update that.

[ehuss]

(Sorry for the noise on this PR, I'm not sure where to move this discussion.)

Looking closer, I think I see what's wrong. Clippy is storing Symbol definitions in globals (lazy_static), but those symbol definitions are only valid for a single session/thread. When rls fires up a second build, clippy reuses those Symbol definitions, but they point to invalid values.

I'm not sure of the best way to fix that. I'm pretty sure Clippy shouldn't be holding any global references to Symbols. Maybe clippy_lints/src/utils/paths.rs could go back to using strs and create Symbols as needed? I'm not sure how much of a performance issue that would be, or if there's a better way.

I'm going to stop looking for now. Feel free to ping me here or on discord if you have any questions. It looks pretty straightforward, though.

[Manishearth]

That's going to be super inefficient. The long term solution for paths.rs is to move as many of those into "diagnostic items" as possible.

Feels like a bug in libsyntax if this can be done safely, though