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

@@ -3151,7 +3151,6 @@ dependencies = [
  "chalk-engine",
  "fmt_macros",
  "graphviz",
- "jobserver",
  "log",
  "measureme",
  "num_cpus",
@@ -3166,6 +3165,7 @@ dependencies = [
  "rustc_feature",
  "rustc_fs_util",
  "rustc_index",
+ "rustc_jobserver",
  "rustc_macros",
  "rustc_session",
  "rustc_target",
@@ -3464,7 +3464,6 @@ version = "0.0.0"
 dependencies = [
  "bitflags",
  "cc",
- "jobserver",
  "libc",
  "log",
  "memmap",
@@ -3478,6 +3477,7 @@ dependencies = [
  "rustc_fs_util",
  "rustc_incremental",
  "rustc_index",
+ "rustc_jobserver",
  "rustc_session",
  "rustc_target",
  "serialize",
@@ -3511,7 +3511,6 @@ dependencies = [
  "ena",
  "graphviz",
  "indexmap",
- "jobserver",
  "lazy_static 1.3.0",
  "log",
  "measureme",
@@ -3623,6 +3622,7 @@ dependencies = [
  "rustc_data_structures",
  "rustc_errors",
  "rustc_incremental",
+ "rustc_jobserver",
  "rustc_lint",
  "rustc_metadata",
  "rustc_mir",
@@ -3643,6 +3643,14 @@ dependencies = [
  "tempfile",
 ]
 
+[[package]]
+name = "rustc_jobserver"
+version = "0.0.0"
+dependencies = [
+ "jobserver",
+ "lazy_static 1.3.0",
+]
+
 [[package]]
 name = "rustc_lexer"
 version = "0.1.0"
@@ -3859,6 +3867,7 @@ dependencies = [
  "rustc_feature",
  "rustc_fs_util",
  "rustc_index",
+ "rustc_jobserver",
  "rustc_target",
  "serialize",
  "syntax_pos",

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" }
 num_cpus = "1.0"
 scoped-tls = "1.0"
 log = { version = "0.4", features = ["release_max_level_info", "std"] }

src/librustc/ty/query/job.rs

@@ -12,7 +12,8 @@ use std::ptr;
 #[cfg(parallel_compiler)]
 use {
     parking_lot::{Mutex, Condvar},
-    rustc_data_structures::{jobserver, OnDrop},
+    rustc_data_structures::{OnDrop},
+    rustc_jobserver as jobserver,
     rustc_data_structures::fx::FxHashSet,
     rustc_data_structures::stable_hasher::{StableHasher, HashStable},
     rustc_data_structures::sync::Lock,

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" }
@@ -33,3 +32,4 @@ rustc_index = { path = "../librustc_index" }
 rustc_target = { path = "../librustc_target" }
 rustc_error_codes = { path = "../librustc_error_codes" }
 rustc_session = { path = "../librustc_session" }
+rustc_jobserver = { path = "../librustc_jobserver" }

src/librustc_codegen_ssa/back/write.rs

@@ -30,7 +30,7 @@ use rustc_target::spec::MergeFunctions;
 use syntax::attr;
 use syntax_pos::hygiene::ExpnId;
 use syntax_pos::symbol::{Symbol, sym};
-use jobserver::{Client, Acquired};
+use rustc_jobserver::{Client, Acquired};
 
 use std::any::Any;
 use std::fs;

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

@@ -75,7 +75,6 @@ pub mod flock;
 pub mod fx;
 pub mod stable_map;
 pub mod graph;
-pub mod jobserver;
 pub mod obligation_forest;
 pub mod owning_ref;
 pub mod ptr_key;

src/librustc_interface/Cargo.toml

@@ -23,6 +23,7 @@ rustc = { path = "../librustc" }
 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

@@ -6,7 +6,7 @@ use rustc::ty;
 use rustc::lint;
 use rustc_codegen_utils::codegen_backend::CodegenBackend;
 #[cfg(parallel_compiler)]
-use rustc_data_structures::jobserver;
+use rustc_jobserver as jobserver;
 use rustc_data_structures::sync::{Lock, Lrc};
 use rustc_data_structures::stable_hasher::StableHasher;
 use rustc_data_structures::fingerprint::Fingerprint;

src/librustc_jobserver/Cargo.toml

@@ -0,0 +1,14 @@
+[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_crate = { version = "0.1.13", package = "jobserver" }
+lazy_static = "1"