Auto merge of rust-lang#135947 - matthiaskrgr:rollup-k9jpfls, r=matthiaskrgr

Rollup of 7 pull requests

Successful merges:

 - rust-lang#135073 (Implement `ByteStr` and `ByteString` types)
 - rust-lang#135492 (Add missing check for async body when suggesting await on futures.)
 - rust-lang#135766 (handle global trait bounds defining assoc types)
 - rust-lang#135880 (Get rid of RunCompiler)
 - rust-lang#135908 (rustc_codegen_llvm: remove outdated asm-to-obj codegen note)
 - rust-lang#135911 (Allow `arena_cache` queries to return `Option<&'tcx T>`)
 - rust-lang#135920 (simplify parse_format::Parser::ws by using next_if)

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

Diff for: Cargo.lock

@@ -4260,7 +4260,6 @@ dependencies = [
  "rustc_serialize",
  "rustc_type_ir",
  "rustc_type_ir_macros",
- "smallvec",
  "tracing",
 ]
 

Diff for: compiler/rustc_codegen_llvm/src/back/write.rs

@@ -769,12 +769,9 @@ pub(crate) unsafe fn codegen(
             }
         }
 
-        // Two things to note:
-        // - If object files are just LLVM bitcode we write bitcode, copy it to
-        //   the .o file, and delete the bitcode if it wasn't otherwise
-        //   requested.
-        // - If we don't have the integrated assembler then we need to emit
-        //   asm from LLVM and use `gcc` to create the object file.
+        // Note that if object files are just LLVM bitcode we write bitcode,
+        // copy it to the .o file, and delete the bitcode if it wasn't
+        // otherwise requested.
 
         let bc_out = cgcx.output_filenames.temp_path(OutputType::Bitcode, module_name);
         let bc_summary_out =

Diff for: compiler/rustc_driver_impl/src/lib.rs

@@ -28,8 +28,8 @@ use std::io::{self, IsTerminal, Read, Write};
 use std::panic::{self, PanicHookInfo, catch_unwind};
 use std::path::{Path, PathBuf};
 use std::process::{self, Command, Stdio};
+use std::sync::OnceLock;
 use std::sync::atomic::{AtomicBool, Ordering};
-use std::sync::{Arc, OnceLock};
 use std::time::{Instant, SystemTime};
 use std::{env, str};
 
@@ -60,7 +60,6 @@ use rustc_session::lint::{Lint, LintId};
 use rustc_session::output::collect_crate_types;
 use rustc_session::{EarlyDiagCtxt, Session, config, filesearch};
 use rustc_span::FileName;
-use rustc_span::source_map::FileLoader;
 use rustc_target::json::ToJson;
 use rustc_target::spec::{Target, TargetTuple};
 use time::OffsetDateTime;
@@ -208,84 +207,7 @@ pub fn diagnostics_registry() -> Registry {
 }
 
 /// This is the primary entry point for rustc.
-pub struct RunCompiler<'a> {
-    at_args: &'a [String],
-    callbacks: &'a mut (dyn Callbacks + Send),
-    file_loader: Option<Box<dyn FileLoader + Send + Sync>>,
-    make_codegen_backend:
-        Option<Box<dyn FnOnce(&config::Options) -> Box<dyn CodegenBackend> + Send>>,
-    using_internal_features: Arc<std::sync::atomic::AtomicBool>,
-}
-
-impl<'a> RunCompiler<'a> {
-    pub fn new(at_args: &'a [String], callbacks: &'a mut (dyn Callbacks + Send)) -> Self {
-        Self {
-            at_args,
-            callbacks,
-            file_loader: None,
-            make_codegen_backend: None,
-            using_internal_features: Arc::default(),
-        }
-    }
-
-    /// Set a custom codegen backend.
-    ///
-    /// Has no uses within this repository, but is used by bjorn3 for "the
-    /// hotswapping branch of cg_clif" for "setting the codegen backend from a
-    /// custom driver where the custom codegen backend has arbitrary data."
-    /// (See #102759.)
-    pub fn set_make_codegen_backend(
-        &mut self,
-        make_codegen_backend: Option<
-            Box<dyn FnOnce(&config::Options) -> Box<dyn CodegenBackend> + Send>,
-        >,
-    ) -> &mut Self {
-        self.make_codegen_backend = make_codegen_backend;
-        self
-    }
-
-    /// Load files from sources other than the file system.
-    ///
-    /// Has no uses within this repository, but may be used in the future by
-    /// bjorn3 for "hooking rust-analyzer's VFS into rustc at some point for
-    /// running rustc without having to save". (See #102759.)
-    pub fn set_file_loader(
-        &mut self,
-        file_loader: Option<Box<dyn FileLoader + Send + Sync>>,
-    ) -> &mut Self {
-        self.file_loader = file_loader;
-        self
-    }
-
-    /// Set the session-global flag that checks whether internal features have been used,
-    /// suppressing the message about submitting an issue in ICEs when enabled.
-    #[must_use]
-    pub fn set_using_internal_features(mut self, using_internal_features: Arc<AtomicBool>) -> Self {
-        self.using_internal_features = using_internal_features;
-        self
-    }
-
-    /// Parse args and run the compiler.
-    pub fn run(self) {
-        run_compiler(
-            self.at_args,
-            self.callbacks,
-            self.file_loader,
-            self.make_codegen_backend,
-            self.using_internal_features,
-        );
-    }
-}
-
-fn run_compiler(
-    at_args: &[String],
-    callbacks: &mut (dyn Callbacks + Send),
-    file_loader: Option<Box<dyn FileLoader + Send + Sync>>,
-    make_codegen_backend: Option<
-        Box<dyn FnOnce(&config::Options) -> Box<dyn CodegenBackend> + Send>,
-    >,
-    using_internal_features: Arc<std::sync::atomic::AtomicBool>,
-) {
+pub fn run_compiler(at_args: &[String], callbacks: &mut (dyn Callbacks + Send)) {
     let mut default_early_dcx = EarlyDiagCtxt::new(ErrorOutputType::default());
 
     // Throw away the first argument, the name of the binary.
@@ -322,16 +244,16 @@ fn run_compiler(
         output_file: ofile,
         output_dir: odir,
         ice_file,
-        file_loader,
+        file_loader: None,
         locale_resources: DEFAULT_LOCALE_RESOURCES.to_vec(),
         lint_caps: Default::default(),
         psess_created: None,
         hash_untracked_state: None,
         register_lints: None,
         override_queries: None,
-        make_codegen_backend,
+        make_codegen_backend: None,
         registry: diagnostics_registry(),
-        using_internal_features,
+        using_internal_features: &USING_INTERNAL_FEATURES,
         expanded_args: args,
     };
 
@@ -1350,6 +1272,8 @@ fn ice_path_with_config(config: Option<&UnstableOptions>) -> &'static Option<Pat
     })
 }
 
+pub static USING_INTERNAL_FEATURES: AtomicBool = AtomicBool::new(false);
+
 /// Installs a panic hook that will print the ICE message on unexpected panics.
 ///
 /// The hook is intended to be useable even by external tools. You can pass a custom
@@ -1360,15 +1284,8 @@ fn ice_path_with_config(config: Option<&UnstableOptions>) -> &'static Option<Pat
 /// If you have no extra info to report, pass the empty closure `|_| ()` as the argument to
 /// extra_info.
 ///
-/// Returns a flag that can be set to disable the note for submitting a bug. This can be passed to
-/// [`RunCompiler::set_using_internal_features`] to let macro expansion set it when encountering
-/// internal features.
-///
 /// A custom rustc driver can skip calling this to set up a custom ICE hook.
-pub fn install_ice_hook(
-    bug_report_url: &'static str,
-    extra_info: fn(&DiagCtxt),
-) -> Arc<AtomicBool> {
+pub fn install_ice_hook(bug_report_url: &'static str, extra_info: fn(&DiagCtxt)) {
     // If the user has not explicitly overridden "RUST_BACKTRACE", then produce
     // full backtraces. When a compiler ICE happens, we want to gather
     // as much information as possible to present in the issue opened
@@ -1385,8 +1302,6 @@ pub fn install_ice_hook(
         }
     }
 
-    let using_internal_features = Arc::new(std::sync::atomic::AtomicBool::default());
-    let using_internal_features_hook = Arc::clone(&using_internal_features);
     panic::update_hook(Box::new(
         move |default_hook: &(dyn Fn(&PanicHookInfo<'_>) + Send + Sync + 'static),
               info: &PanicHookInfo<'_>| {
@@ -1438,11 +1353,9 @@ pub fn install_ice_hook(
             }
 
             // Print the ICE message
-            report_ice(info, bug_report_url, extra_info, &using_internal_features_hook);
+            report_ice(info, bug_report_url, extra_info, &USING_INTERNAL_FEATURES);
         },
     ));
-
-    using_internal_features
 }
 
 /// Prints the ICE message, including query stack, but without backtrace.
@@ -1583,13 +1496,11 @@ pub fn main() -> ! {
     init_rustc_env_logger(&early_dcx);
     signal_handler::install();
     let mut callbacks = TimePassesCallbacks::default();
-    let using_internal_features = install_ice_hook(DEFAULT_BUG_REPORT_URL, |_| ());
+    install_ice_hook(DEFAULT_BUG_REPORT_URL, |_| ());
     install_ctrlc_handler();
 
     let exit_code = catch_with_exit_code(|| {
-        RunCompiler::new(&args::raw_args(&early_dcx)?, &mut callbacks)
-            .set_using_internal_features(using_internal_features)
-            .run();
+        run_compiler(&args::raw_args(&early_dcx)?, &mut callbacks);
         Ok(())
     });
 

Diff for: compiler/rustc_interface/src/interface.rs

@@ -1,6 +1,5 @@
 use std::path::PathBuf;
 use std::result;
-use std::sync::Arc;
 
 use rustc_ast::{LitKind, MetaItemKind, token};
 use rustc_codegen_ssa::traits::CodegenBackend;
@@ -309,6 +308,11 @@ pub struct Config {
     pub output_dir: Option<PathBuf>,
     pub output_file: Option<OutFileName>,
     pub ice_file: Option<PathBuf>,
+    /// Load files from sources other than the file system.
+    ///
+    /// Has no uses within this repository, but may be used in the future by
+    /// bjorn3 for "hooking rust-analyzer's VFS into rustc at some point for
+    /// running rustc without having to save". (See #102759.)
     pub file_loader: Option<Box<dyn FileLoader + Send + Sync>>,
     /// The list of fluent resources, used for lints declared with
     /// [`Diagnostic`](rustc_errors::Diagnostic) and [`LintDiagnostic`](rustc_errors::LintDiagnostic).
@@ -337,6 +341,11 @@ pub struct Config {
     pub override_queries: Option<fn(&Session, &mut Providers)>,
 
     /// This is a callback from the driver that is called to create a codegen backend.
+    ///
+    /// Has no uses within this repository, but is used by bjorn3 for "the
+    /// hotswapping branch of cg_clif" for "setting the codegen backend from a
+    /// custom driver where the custom codegen backend has arbitrary data."
+    /// (See #102759.)
     pub make_codegen_backend:
         Option<Box<dyn FnOnce(&config::Options) -> Box<dyn CodegenBackend> + Send>>,
 
@@ -346,8 +355,7 @@ pub struct Config {
     /// The inner atomic value is set to true when a feature marked as `internal` is
     /// enabled. Makes it so that "please report a bug" is hidden, as ICEs with
     /// internal features are wontfix, and they are usually the cause of the ICEs.
-    /// None signifies that this is not tracked.
-    pub using_internal_features: Arc<std::sync::atomic::AtomicBool>,
+    pub using_internal_features: &'static std::sync::atomic::AtomicBool,
 
     /// All commandline args used to invoke the compiler, with @file args fully expanded.
     /// This will only be used within debug info, e.g. in the pdb file on windows

Diff for: compiler/rustc_interface/src/tests.rs

@@ -2,7 +2,7 @@
 use std::collections::{BTreeMap, BTreeSet};
 use std::num::NonZero;
 use std::path::{Path, PathBuf};
-use std::sync::Arc;
+use std::sync::atomic::AtomicBool;
 
 use rustc_data_structures::profiling::TimePassesFormat;
 use rustc_errors::emitter::HumanReadableErrorType;
@@ -62,6 +62,8 @@ where
             temps_dir,
         };
 
+        static USING_INTERNAL_FEATURES: AtomicBool = AtomicBool::new(false);
+
         let sess = build_session(
             early_dcx,
             sessopts,
@@ -74,7 +76,7 @@ where
             sysroot,
             "",
             None,
-            Arc::default(),
+            &USING_INTERNAL_FEATURES,
             Default::default(),
         );
         let cfg = parse_cfg(sess.dcx(), matches.opt_strs("cfg"));

Diff for: compiler/rustc_middle/src/query/arena_cached.rs

@@ -0,0 +1,47 @@
+/// Helper trait that allows `arena_cache` queries to return `Option<&T>`
+/// instead of `&Option<T>`, and avoid allocating `None` in the arena.
+///
+/// An arena-cached query must be declared to return a type that implements
+/// this trait, i.e. either `&'tcx T` or `Option<&'tcx T>`. This trait then
+/// determines the types returned by the provider and stored in the arena,
+/// and provides a function to bridge between the three types.
+pub trait ArenaCached<'tcx>: Sized {
+    /// Type that is returned by the query provider.
+    type Provided;
+    /// Type that is stored in the arena.
+    type Allocated: 'tcx;
+
+    /// Takes a provided value, and allocates it in the arena (if appropriate)
+    /// with the help of the given `arena_alloc` closure.
+    fn alloc_in_arena(
+        arena_alloc: impl Fn(Self::Allocated) -> &'tcx Self::Allocated,
+        value: Self::Provided,
+    ) -> Self;
+}
+
+impl<'tcx, T> ArenaCached<'tcx> for &'tcx T {
+    type Provided = T;
+    type Allocated = T;
+
+    fn alloc_in_arena(
+        arena_alloc: impl Fn(Self::Allocated) -> &'tcx Self::Allocated,
+        value: Self::Provided,
+    ) -> Self {
+        // Just allocate in the arena normally.
+        arena_alloc(value)
+    }
+}
+
+impl<'tcx, T> ArenaCached<'tcx> for Option<&'tcx T> {
+    type Provided = Option<T>;
+    /// The provide value is `Option<T>`, but we only store `T` in the arena.
+    type Allocated = T;
+
+    fn alloc_in_arena(
+        arena_alloc: impl Fn(Self::Allocated) -> &'tcx Self::Allocated,
+        value: Self::Provided,
+    ) -> Self {
+        // Don't store None in the arena, and wrap the allocated reference in Some.
+        value.map(arena_alloc)
+    }
+}

Diff for: compiler/rustc_middle/src/query/mod.rs

@@ -7,7 +7,6 @@
 #![allow(unused_parens)]
 
 use std::mem;
-use std::ops::Deref;
 use std::path::PathBuf;
 use std::sync::Arc;
 
@@ -85,6 +84,7 @@ use crate::ty::{
 };
 use crate::{dep_graph, mir, thir};
 
+mod arena_cached;
 pub mod erase;
 mod keys;
 pub use keys::{AsLocalKey, Key, LocalCrate};
@@ -586,7 +586,7 @@ rustc_queries! {
         separate_provide_extern
     }
 
-    query mir_coroutine_witnesses(key: DefId) -> &'tcx Option<mir::CoroutineLayout<'tcx>> {
+    query mir_coroutine_witnesses(key: DefId) -> Option<&'tcx mir::CoroutineLayout<'tcx>> {
         arena_cache
         desc { |tcx| "coroutine witness types for `{}`", tcx.def_path_str(key) }
         cache_on_disk_if { key.is_local() }
@@ -2415,7 +2415,7 @@ rustc_queries! {
     /// because the `ty::Ty`-based wfcheck is always run.
     query diagnostic_hir_wf_check(
         key: (ty::Predicate<'tcx>, WellFormedLoc)
-    ) -> &'tcx Option<ObligationCause<'tcx>> {
+    ) -> Option<&'tcx ObligationCause<'tcx>> {
         arena_cache
         eval_always
         no_hash