Move jobserver integration into separate crate

Future commits on this branch will make our implementation pretty
specific to rustc (i.e., talking to Cargo and such) so coupling
ourselves into rustc_data_structures which is intended to be more
"agnostic" isn't a great fit.

This also removes uses of the jobserver inside rustc that refer directly
to the `jobsever` crate (and similar cleanups will follow in the next
few commits).

Author: Mark-Simulacrum

Cargo.lock

@@ -3113,7 +3113,6 @@ dependencies = [
  "chalk-engine",
  "fmt_macros",
  "graphviz",
- "jobserver",
  "log",
  "measureme",
  "parking_lot 0.9.0",
@@ -3127,6 +3126,7 @@ dependencies = [
  "rustc_feature",
  "rustc_hir",
  "rustc_index",
+ "rustc_jobserver",
  "rustc_macros",
  "rustc_session",
  "rustc_span",
@@ -3587,7 +3587,6 @@ version = "0.0.0"
 dependencies = [
  "bitflags",
  "cc",
- "jobserver",
  "libc",
  "log",
  "memmap",
@@ -3602,6 +3601,7 @@ dependencies = [
  "rustc_hir",
  "rustc_incremental",
  "rustc_index",
+ "rustc_jobserver",
  "rustc_session",
  "rustc_span",
  "rustc_target",
@@ -3636,7 +3636,6 @@ dependencies = [
  "ena",
  "graphviz",
  "indexmap",
- "jobserver",
  "lazy_static 1.4.0",
  "log",
  "measureme",
@@ -3796,6 +3795,7 @@ dependencies = [
  "rustc_expand",
  "rustc_hir",
  "rustc_incremental",
+ "rustc_jobserver",
  "rustc_lint",
  "rustc_metadata",
  "rustc_mir",
@@ -3818,6 +3818,15 @@ dependencies = [
  "winapi 0.3.8",
 ]
 
+[[package]]
+name = "rustc_jobserver"
+version = "0.0.0"
+dependencies = [
+ "jobserver",
+ "lazy_static 1.4.0",
+ "log",
+]
+
 [[package]]
 name = "rustc_lexer"
 version = "0.1.0"
@@ -4055,6 +4064,7 @@ dependencies = [
  "rustc_feature",
  "rustc_fs_util",
  "rustc_index",
+ "rustc_jobserver",
  "rustc_span",
  "rustc_target",
  "serialize",

src/librustc/Cargo.toml

@@ -14,7 +14,7 @@ arena = { path = "../libarena" }
 bitflags = "1.2.1"
 fmt_macros = { path = "../libfmt_macros" }
 graphviz = { path = "../libgraphviz" }
-jobserver = "0.1"
+rustc_jobserver = { path = "../librustc_jobserver" }
 scoped-tls = "1.0"
 log = { version = "0.4", features = ["release_max_level_info", "std"] }
 rustc-rayon = "0.3.0"

src/librustc/ty/query/job.rs

@@ -18,8 +18,8 @@ use {
     rustc_data_structures::stable_hasher::{HashStable, StableHasher},
     rustc_data_structures::sync::Lock,
     rustc_data_structures::sync::Lrc,
-    rustc_data_structures::{jobserver, OnDrop},
-    rustc_rayon_core as rayon_core,
+    rustc_data_structures::OnDrop,
+    rustc_jobserver as jobserver, rustc_rayon_core as rayon_core,
     rustc_span::DUMMY_SP,
     std::iter::FromIterator,
     std::{mem, process, thread},

src/librustc_codegen_ssa/Cargo.toml

@@ -16,7 +16,6 @@ num_cpus = "1.0"
 memmap = "0.7"
 log = "0.4.5"
 libc = "0.2.44"
-jobserver = "0.1.11"
 tempfile = "3.1"
 
 rustc_serialize = { path = "../libserialize", package = "serialize" }
@@ -34,3 +33,4 @@ rustc_incremental = { path = "../librustc_incremental" }
 rustc_index = { path = "../librustc_index" }
 rustc_target = { path = "../librustc_target" }
 rustc_session = { path = "../librustc_session" }
+rustc_jobserver = { path = "../librustc_jobserver" }

src/librustc_codegen_ssa/back/write.rs

@@ -10,7 +10,6 @@ use crate::{
 };
 
 use crate::traits::*;
-use jobserver::{Acquired, Client};
 use rustc::dep_graph::{WorkProduct, WorkProductFileKind, WorkProductId};
 use rustc::middle::cstore::EncodedMetadata;
 use rustc::middle::exported_symbols::SymbolExportLevel;
@@ -32,6 +31,7 @@ use rustc_hir::def_id::{CrateNum, LOCAL_CRATE};
 use rustc_incremental::{
     copy_cgu_workproducts_to_incr_comp_cache_dir, in_incr_comp_dir, in_incr_comp_dir_sess,
 };
+use rustc_jobserver::{Acquired, Client};
 use rustc_session::cgu_reuse_tracker::CguReuseTracker;
 use rustc_span::hygiene::ExpnId;
 use rustc_span::source_map::SourceMap;

src/librustc_data_structures/Cargo.toml

@@ -13,7 +13,6 @@ doctest = false
 ena = "0.13.1"
 indexmap = "1"
 log = "0.4"
-jobserver_crate = { version = "0.1.13", package = "jobserver" }
 lazy_static = "1"
 rustc_serialize = { path = "../libserialize", package = "serialize" }
 graphviz = { path = "../libgraphviz" }

src/librustc_data_structures/lib.rs

@@ -67,7 +67,6 @@ pub mod const_cstr;
 pub mod flock;
 pub mod fx;
 pub mod graph;
-pub mod jobserver;
 pub mod macros;
 pub mod obligation_forest;
 pub mod owning_ref;

src/librustc_interface/Cargo.toml

@@ -27,6 +27,7 @@ rustc_ast_passes = { path = "../librustc_ast_passes" }
 rustc_incremental = { path = "../librustc_incremental" }
 rustc_traits = { path = "../librustc_traits" }
 rustc_data_structures = { path = "../librustc_data_structures" }
+rustc_jobserver = { path = "../librustc_jobserver" }
 rustc_codegen_ssa = { path = "../librustc_codegen_ssa" }
 rustc_codegen_utils = { path = "../librustc_codegen_utils" }
 rustc_codegen_llvm = { path = "../librustc_codegen_llvm", optional = true }

src/librustc_interface/util.rs

@@ -4,11 +4,11 @@ use rustc::ty;
 use rustc_codegen_utils::codegen_backend::CodegenBackend;
 use rustc_data_structures::fingerprint::Fingerprint;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
-#[cfg(parallel_compiler)]
-use rustc_data_structures::jobserver;
 use rustc_data_structures::stable_hasher::StableHasher;
 use rustc_data_structures::sync::{Lock, Lrc};
 use rustc_errors::registry::Registry;
+#[cfg(parallel_compiler)]
+use rustc_jobserver as jobserver;
 use rustc_metadata::dynamic_lib::DynamicLibrary;
 use rustc_resolve::{self, Resolver};
 use rustc_session as session;

src/librustc_jobserver/Cargo.toml

@@ -0,0 +1,15 @@
+[package]
+authors = ["The Rust Project Developers"]
+name = "rustc_jobserver"
+version = "0.0.0"
+edition = "2018"
+
+[lib]
+name = "rustc_jobserver"
+path = "lib.rs"
+doctest = false
+
+[dependencies]
+jobserver = "0.1.21"
+log = "0.4"
+lazy_static = "1"