Rollup merge of #134251 - bjorn3:various_cleanups2, r=oli-obk

A bunch of cleanups (part 2)

Just like https://github.com/rust-lang/rust/pull/133567 these were all found while looking at the respective code, but are not blocking any other changes I want to make in the short term.

compiler/rustc_codegen_ssa/Cargo.toml

@@ -11,7 +11,6 @@ bitflags = "2.4.1"
 cc = "1.1.23"
 either = "1.5.0"
 itertools = "0.12"
-jobserver = "0.1.28"
 pathdiff = "0.2.0"
 regex = "1.4"
 rustc_abi = { path = "../rustc_abi" }

compiler/rustc_codegen_ssa/src/back/link.rs

@@ -236,7 +236,13 @@ pub fn each_linked_rlib(
 ) -> Result<(), errors::LinkRlibError> {
     let crates = info.used_crates.iter();
 
-    let fmts = if crate_type.is_none() {
+    let fmts = if let Some(crate_type) = crate_type {
+        let Some(fmts) = info.dependency_formats.get(&crate_type) else {
+            return Err(errors::LinkRlibError::MissingFormat);
+        };
+
+        fmts
+    } else {
         for combination in info.dependency_formats.iter().combinations(2) {
             let (ty1, list1) = &combination[0];
             let (ty2, list2) = &combination[1];
@@ -252,18 +258,7 @@ pub fn each_linked_rlib(
         if info.dependency_formats.is_empty() {
             return Err(errors::LinkRlibError::MissingFormat);
         }
-        &info.dependency_formats[0].1
-    } else {
-        let fmts = info
-            .dependency_formats
-            .iter()
-            .find_map(|&(ty, ref list)| if Some(ty) == crate_type { Some(list) } else { None });
-
-        let Some(fmts) = fmts else {
-            return Err(errors::LinkRlibError::MissingFormat);
-        };
-
-        fmts
+        info.dependency_formats.first().unwrap().1
     };
 
     for &cnum in crates {
@@ -624,8 +619,7 @@ fn link_staticlib(
     let fmts = codegen_results
         .crate_info
         .dependency_formats
-        .iter()
-        .find_map(|&(ty, ref list)| if ty == CrateType::Staticlib { Some(list) } else { None })
+        .get(&CrateType::Staticlib)
         .expect("no dependency formats for staticlib");
 
     let mut all_rust_dylibs = vec![];
@@ -2355,11 +2349,10 @@ fn linker_with_args(
     // they are used within inlined functions or instantiated generic functions. We do this *after*
     // handling the raw-dylib symbols in the current crate to make sure that those are chosen first
     // by the linker.
-    let (_, dependency_linkage) = codegen_results
+    let dependency_linkage = codegen_results
         .crate_info
         .dependency_formats
-        .iter()
-        .find(|(ty, _)| *ty == crate_type)
+        .get(&crate_type)
         .expect("failed to find crate type in dependency format list");
 
     // We sort the libraries below
@@ -2738,11 +2731,10 @@ fn add_upstream_rust_crates(
     // Linking to a rlib involves just passing it to the linker (the linker
     // will slurp up the object files inside), and linking to a dynamic library
     // involves just passing the right -l flag.
-    let (_, data) = codegen_results
+    let data = codegen_results
         .crate_info
         .dependency_formats
-        .iter()
-        .find(|(ty, _)| *ty == crate_type)
+        .get(&crate_type)
         .expect("failed to find crate type in dependency format list");
 
     if sess.target.is_like_aix {

compiler/rustc_codegen_ssa/src/back/linker.rs

@@ -1749,7 +1749,7 @@ fn for_each_exported_symbols_include_dep<'tcx>(
     }
 
     let formats = tcx.dependency_formats(());
-    let deps = formats.iter().find_map(|(t, list)| (*t == crate_type).then_some(list)).unwrap();
+    let deps = &formats[&crate_type];
 
     for (index, dep_format) in deps.iter().enumerate() {
         let cnum = CrateNum::new(index + 1);

compiler/rustc_codegen_ssa/src/back/write.rs

@@ -6,9 +6,9 @@ use std::sync::Arc;
 use std::sync::mpsc::{Receiver, Sender, channel};
 use std::{fs, io, mem, str, thread};
 
-use jobserver::{Acquired, Client};
 use rustc_ast::attr;
 use rustc_data_structures::fx::{FxHashMap, FxIndexMap};
+use rustc_data_structures::jobserver::{self, Acquired};
 use rustc_data_structures::memmap::Mmap;
 use rustc_data_structures::profiling::{SelfProfilerRef, VerboseTimingGuard};
 use rustc_errors::emitter::Emitter;
@@ -456,7 +456,6 @@ pub(crate) fn start_async_codegen<B: ExtraBackendMethods>(
     metadata_module: Option<CompiledModule>,
 ) -> OngoingCodegen<B> {
     let (coordinator_send, coordinator_receive) = channel();
-    let sess = tcx.sess;
 
     let crate_attrs = tcx.hir().attrs(rustc_hir::CRATE_HIR_ID);
     let no_builtins = attr::contains_name(crate_attrs, sym::no_builtins);
@@ -477,7 +476,6 @@ pub(crate) fn start_async_codegen<B: ExtraBackendMethods>(
         shared_emitter,
         codegen_worker_send,
         coordinator_receive,
-        sess.jobserver.clone(),
         Arc::new(regular_config),
         Arc::new(metadata_config),
         Arc::new(allocator_config),
@@ -1093,7 +1091,6 @@ fn start_executing_work<B: ExtraBackendMethods>(
     shared_emitter: SharedEmitter,
     codegen_worker_send: Sender<CguMessage>,
     coordinator_receive: Receiver<Box<dyn Any + Send>>,
-    jobserver: Client,
     regular_config: Arc<ModuleConfig>,
     metadata_config: Arc<ModuleConfig>,
     allocator_config: Arc<ModuleConfig>,
@@ -1145,7 +1142,7 @@ fn start_executing_work<B: ExtraBackendMethods>(
     // get tokens on `coordinator_receive` which will
     // get managed in the main loop below.
     let coordinator_send2 = coordinator_send.clone();
-    let helper = jobserver
+    let helper = jobserver::client()
         .into_helper_thread(move |token| {
             drop(coordinator_send2.send(Box::new(Message::Token::<B>(token))));
         })