Rollup of 7 pull requests

bootstrap.example.toml

@@ -859,6 +859,14 @@
 # Trigger a `DebugBreak` after an internal compiler error during bootstrap on Windows
 #rust.break-on-ice = true
 
+# Set the number of threads for the compiler frontend used during compilation of Rust code (passed to `-Zthreads`).
+# The valid options are:
+# 0 - Set the number of threads according to the detected number of threads of the host system
+# 1 - Use a single thread for compilation of Rust code (the default)
+# N - Number of threads used for compilation of Rust code
+#
+#rust.parallel-frontend-threads = 1
+
 # =============================================================================
 # Distribution options
 #

compiler/rustc/Cargo.toml

@@ -30,6 +30,7 @@ features = ['unprefixed_malloc_on_supported_platforms']
 check_only = ['rustc_driver_impl/check_only']
 jemalloc = ['dep:tikv-jemalloc-sys']
 llvm = ['rustc_driver_impl/llvm']
+llvm_enzyme = ['rustc_driver_impl/llvm_enzyme']
 max_level_info = ['rustc_driver_impl/max_level_info']
 rustc_randomized_layouts = ['rustc_driver_impl/rustc_randomized_layouts']
 # tidy-alphabetical-end

compiler/rustc_attr_parsing/src/attributes/crate_level.rs

@@ -174,3 +174,12 @@ impl<S: Stage> NoArgsAttributeParser<S> for NoStdParser {
     const ALLOWED_TARGETS: AllowedTargets = AllowedTargets::CrateLevel;
     const CREATE: fn(Span) -> AttributeKind = AttributeKind::NoStd;
 }
+
+pub(crate) struct RustcCoherenceIsCoreParser;
+
+impl<S: Stage> NoArgsAttributeParser<S> for RustcCoherenceIsCoreParser {
+    const PATH: &[Symbol] = &[sym::rustc_coherence_is_core];
+    const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Error;
+    const ALLOWED_TARGETS: AllowedTargets = AllowedTargets::CrateLevel;
+    const CREATE: fn(Span) -> AttributeKind = AttributeKind::RustcCoherenceIsCore;
+}

compiler/rustc_attr_parsing/src/attributes/traits.rs

@@ -149,14 +149,6 @@ impl<S: Stage> NoArgsAttributeParser<S> for AllowIncoherentImplParser {
     const CREATE: fn(Span) -> AttributeKind = AttributeKind::AllowIncoherentImpl;
 }
 
-pub(crate) struct CoherenceIsCoreParser;
-impl<S: Stage> NoArgsAttributeParser<S> for CoherenceIsCoreParser {
-    const PATH: &[Symbol] = &[sym::rustc_coherence_is_core];
-    const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Error;
-    const ALLOWED_TARGETS: AllowedTargets = AllowedTargets::CrateLevel;
-    const CREATE: fn(Span) -> AttributeKind = |_| AttributeKind::CoherenceIsCore;
-}
-
 pub(crate) struct FundamentalParser;
 impl<S: Stage> NoArgsAttributeParser<S> for FundamentalParser {
     const PATH: &[Symbol] = &[sym::fundamental];

compiler/rustc_attr_parsing/src/context.rs

@@ -26,7 +26,7 @@ use crate::attributes::codegen_attrs::{
 use crate::attributes::confusables::ConfusablesParser;
 use crate::attributes::crate_level::{
     CrateNameParser, MoveSizeLimitParser, NoCoreParser, NoStdParser, PatternComplexityLimitParser,
-    RecursionLimitParser, TypeLengthLimitParser,
+    RecursionLimitParser, RustcCoherenceIsCoreParser, TypeLengthLimitParser,
 };
 use crate::attributes::deprecation::DeprecationParser;
 use crate::attributes::dummy::DummyParser;
@@ -61,10 +61,10 @@ use crate::attributes::stability::{
 };
 use crate::attributes::test_attrs::{IgnoreParser, ShouldPanicParser};
 use crate::attributes::traits::{
-    AllowIncoherentImplParser, CoherenceIsCoreParser, CoinductiveParser, ConstTraitParser,
-    DenyExplicitImplParser, DoNotImplementViaObjectParser, FundamentalParser, MarkerParser,
-    ParenSugarParser, PointeeParser, SkipDuringMethodDispatchParser, SpecializationTraitParser,
-    TypeConstParser, UnsafeSpecializationMarkerParser,
+    AllowIncoherentImplParser, CoinductiveParser, ConstTraitParser, DenyExplicitImplParser,
+    DoNotImplementViaObjectParser, FundamentalParser, MarkerParser, ParenSugarParser,
+    PointeeParser, SkipDuringMethodDispatchParser, SpecializationTraitParser, TypeConstParser,
+    UnsafeSpecializationMarkerParser,
 };
 use crate::attributes::transparency::TransparencyParser;
 use crate::attributes::{AttributeParser as _, Combine, Single, WithoutArgs};
@@ -206,7 +206,6 @@ attribute_parsers!(
         Single<WithoutArgs<AllowInternalUnsafeParser>>,
         Single<WithoutArgs<AsPtrParser>>,
         Single<WithoutArgs<AutomaticallyDerivedParser>>,
-        Single<WithoutArgs<CoherenceIsCoreParser>>,
         Single<WithoutArgs<CoinductiveParser>>,
         Single<WithoutArgs<ColdParser>>,
         Single<WithoutArgs<ConstContinueParser>>,
@@ -234,6 +233,7 @@ attribute_parsers!(
         Single<WithoutArgs<ProcMacroAttributeParser>>,
         Single<WithoutArgs<ProcMacroParser>>,
         Single<WithoutArgs<PubTransparentParser>>,
+        Single<WithoutArgs<RustcCoherenceIsCoreParser>>,
         Single<WithoutArgs<SpecializationTraitParser>>,
         Single<WithoutArgs<StdInternalSymbolParser>>,
         Single<WithoutArgs<TrackCallerParser>>,

compiler/rustc_builtin_macros/Cargo.toml

@@ -33,3 +33,8 @@ smallvec = { version = "1.8.1", features = ["union", "may_dangle"] }
 thin-vec = "0.2.12"
 tracing = "0.1"
 # tidy-alphabetical-end
+
+[features]
+# tidy-alphabetical-start
+llvm_enzyme = []
+# tidy-alphabetical-end

compiler/rustc_builtin_macros/src/autodiff.rs

@@ -209,7 +209,8 @@ mod llvm_enzyme {
         mut item: Annotatable,
         mode: DiffMode,
     ) -> Vec<Annotatable> {
-        if cfg!(not(llvm_enzyme)) {
+        // FIXME(bjorn3) maybe have the backend directly tell if autodiff is supported?
+        if cfg!(not(feature = "llvm_enzyme")) {
             ecx.sess.dcx().emit_err(errors::AutoDiffSupportNotBuild { span: meta_item.span });
             return vec![item];
         }

compiler/rustc_codegen_gcc/src/intrinsic/mod.rs

@@ -730,7 +730,7 @@ impl<'gcc, 'tcx> ArgAbiExt<'gcc, 'tcx> for ArgAbi<'tcx, Ty<'tcx>> {
         if self.is_sized_indirect() {
             OperandValue::Ref(PlaceValue::new_sized(val, self.layout.align.abi)).store(bx, dst)
         } else if self.is_unsized_indirect() {
-            bug!("unsized `ArgAbi` must be handled through `store_fn_arg`");
+            bug!("unsized `ArgAbi` cannot be stored");
         } else if let PassMode::Cast { ref cast, .. } = self.mode {
             // FIXME(eddyb): Figure out when the simpler Store is safe, clang
             // uses it for i16 -> {i8, i8}, but not for i24 -> {i8, i8, i8}.
@@ -797,12 +797,7 @@ impl<'gcc, 'tcx> ArgAbiExt<'gcc, 'tcx> for ArgAbi<'tcx, Ty<'tcx>> {
                 OperandValue::Pair(next(), next()).store(bx, dst);
             }
             PassMode::Indirect { meta_attrs: Some(_), .. } => {
-                let place_val = PlaceValue {
-                    llval: next(),
-                    llextra: Some(next()),
-                    align: self.layout.align.abi,
-                };
-                OperandValue::Ref(place_val).store(bx, dst);
+                bug!("unsized `ArgAbi` cannot be stored");
             }
             PassMode::Direct(_)
             | PassMode::Indirect { meta_attrs: None, .. }

compiler/rustc_codegen_llvm/Cargo.toml

@@ -46,5 +46,6 @@ tracing = "0.1"
 [features]
 # tidy-alphabetical-start
 check_only = ["rustc_llvm/check_only"]
+llvm_enzyme = []
 # tidy-alphabetical-end
 

compiler/rustc_codegen_llvm/src/abi.rs

@@ -215,9 +215,9 @@ impl<'ll, 'tcx> ArgAbiExt<'ll, 'tcx> for ArgAbi<'tcx, Ty<'tcx>> {
                 let align = attrs.pointee_align.unwrap_or(self.layout.align.abi);
                 OperandValue::Ref(PlaceValue::new_sized(val, align)).store(bx, dst);
             }
-            // Unsized indirect qrguments
+            // Unsized indirect arguments cannot be stored
             PassMode::Indirect { attrs: _, meta_attrs: Some(_), on_stack: _ } => {
-                bug!("unsized `ArgAbi` must be handled through `store_fn_arg`");
+                bug!("unsized `ArgAbi` cannot be stored");
             }
             PassMode::Cast { cast, pad_i32: _ } => {
                 // The ABI mandates that the value is passed as a different struct representation.
@@ -272,12 +272,7 @@ impl<'ll, 'tcx> ArgAbiExt<'ll, 'tcx> for ArgAbi<'tcx, Ty<'tcx>> {
                 OperandValue::Pair(next(), next()).store(bx, dst);
             }
             PassMode::Indirect { attrs: _, meta_attrs: Some(_), on_stack: _ } => {
-                let place_val = PlaceValue {
-                    llval: next(),
-                    llextra: Some(next()),
-                    align: self.layout.align.abi,
-                };
-                OperandValue::Ref(place_val).store(bx, dst);
+                bug!("unsized `ArgAbi` cannot be stored");
             }
             PassMode::Direct(_)
             | PassMode::Indirect { attrs: _, meta_attrs: None, on_stack: _ }

compiler/rustc_codegen_llvm/src/back/lto.rs

@@ -617,7 +617,7 @@ pub(crate) fn run_pass_manager(
         crate::builder::gpu_offload::handle_gpu_code(cgcx, &cx);
     }
 
-    if cfg!(llvm_enzyme) && enable_ad && !thin {
+    if cfg!(feature = "llvm_enzyme") && enable_ad && !thin {
         let opt_stage = llvm::OptStage::FatLTO;
         let stage = write::AutodiffStage::PostAD;
         if !config.autodiff.contains(&config::AutoDiff::NoPostopt) {

compiler/rustc_codegen_llvm/src/back/write.rs

@@ -574,7 +574,8 @@ pub(crate) unsafe fn llvm_optimize(
     // FIXME(ZuseZ4): In a future update we could figure out how to only optimize individual functions getting
     // differentiated.
 
-    let consider_ad = cfg!(llvm_enzyme) && config.autodiff.contains(&config::AutoDiff::Enable);
+    let consider_ad =
+        cfg!(feature = "llvm_enzyme") && config.autodiff.contains(&config::AutoDiff::Enable);
     let run_enzyme = autodiff_stage == AutodiffStage::DuringAD;
     let print_before_enzyme = config.autodiff.contains(&config::AutoDiff::PrintModBefore);
     let print_after_enzyme = config.autodiff.contains(&config::AutoDiff::PrintModAfter);
@@ -740,7 +741,8 @@ pub(crate) fn optimize(
 
         // If we know that we will later run AD, then we disable vectorization and loop unrolling.
         // Otherwise we pretend AD is already done and run the normal opt pipeline (=PostAD).
-        let consider_ad = cfg!(llvm_enzyme) && config.autodiff.contains(&config::AutoDiff::Enable);
+        let consider_ad =
+            cfg!(feature = "llvm_enzyme") && config.autodiff.contains(&config::AutoDiff::Enable);
         let autodiff_stage = if consider_ad { AutodiffStage::PreAD } else { AutodiffStage::PostAD };
         // The embedded bitcode is used to run LTO/ThinLTO.
         // The bitcode obtained during the `codegen` phase is no longer suitable for performing LTO.

compiler/rustc_codegen_llvm/src/llvm/enzyme_ffi.rs

@@ -59,10 +59,10 @@ pub(crate) enum LLVMRustVerifierFailureAction {
     LLVMReturnStatusAction = 2,
 }
 
-#[cfg(llvm_enzyme)]
+#[cfg(feature = "llvm_enzyme")]
 pub(crate) use self::Enzyme_AD::*;
 
-#[cfg(llvm_enzyme)]
+#[cfg(feature = "llvm_enzyme")]
 pub(crate) mod Enzyme_AD {
     use std::ffi::{CString, c_char};
 
@@ -134,10 +134,10 @@ pub(crate) mod Enzyme_AD {
     }
 }
 
-#[cfg(not(llvm_enzyme))]
+#[cfg(not(feature = "llvm_enzyme"))]
 pub(crate) use self::Fallback_AD::*;
 
-#[cfg(not(llvm_enzyme))]
+#[cfg(not(feature = "llvm_enzyme"))]
 pub(crate) mod Fallback_AD {
     #![allow(unused_variables)]
 

compiler/rustc_driver_impl/Cargo.toml

@@ -74,6 +74,7 @@ ctrlc = "3.4.4"
 # tidy-alphabetical-start
 check_only = ['rustc_interface/check_only']
 llvm = ['rustc_interface/llvm']
+llvm_enzyme = ['rustc_interface/llvm_enzyme']
 max_level_info = ['rustc_log/max_level_info']
 rustc_randomized_layouts = [
     'rustc_index/rustc_randomized_layouts',

compiler/rustc_hir/src/attrs/data_structures.rs

@@ -444,9 +444,6 @@ pub enum AttributeKind {
         span: Span,
     },
 
-    /// Represents `#[rustc_coherence_is_core]`.
-    CoherenceIsCore,
-
     /// Represents `#[rustc_coinductive]`.
     Coinductive(Span),
 
@@ -639,6 +636,9 @@ pub enum AttributeKind {
     /// Represents `#[rustc_builtin_macro]`.
     RustcBuiltinMacro { builtin_name: Option<Symbol>, helper_attrs: ThinVec<Symbol>, span: Span },
 
+    /// Represents `#[rustc_coherence_is_core]`
+    RustcCoherenceIsCore(Span),
+
     /// Represents `#[rustc_layout_scalar_valid_range_end]`.
     RustcLayoutScalarValidRangeEnd(Box<u128>, Span),
 

compiler/rustc_hir/src/attrs/encode_cross_crate.rs

@@ -26,7 +26,6 @@ impl AttributeKind {
             AsPtr(..) => Yes,
             AutomaticallyDerived(..) => Yes,
             BodyStability { .. } => No,
-            CoherenceIsCore => No,
             Coinductive(..) => No,
             Cold(..) => No,
             Confusables { .. } => Yes,
@@ -84,6 +83,7 @@ impl AttributeKind {
             RecursionLimit { .. } => No,
             Repr { .. } => No,
             RustcBuiltinMacro { .. } => Yes,
+            RustcCoherenceIsCore(..) => No,
             RustcLayoutScalarValidRangeEnd(..) => Yes,
             RustcLayoutScalarValidRangeStart(..) => Yes,
             RustcObjectLifetimeDefault => No,

compiler/rustc_interface/Cargo.toml

@@ -58,4 +58,5 @@ rustc_abi = { path = "../rustc_abi" }
 # tidy-alphabetical-start
 check_only = ['rustc_codegen_llvm?/check_only']
 llvm = ['dep:rustc_codegen_llvm']
+llvm_enzyme = ['rustc_builtin_macros/llvm_enzyme', 'rustc_codegen_llvm/llvm_enzyme']
 # tidy-alphabetical-end

compiler/rustc_middle/src/hir/map.rs

@@ -370,7 +370,7 @@ impl<'tcx> TyCtxt<'tcx> {
     }
 
     pub fn hir_rustc_coherence_is_core(self) -> bool {
-        find_attr!(self.hir_krate_attrs(), AttributeKind::CoherenceIsCore)
+        find_attr!(self.hir_krate_attrs(), AttributeKind::RustcCoherenceIsCore(..))
     }
 
     pub fn hir_get_module(self, module: LocalModDefId) -> (&'tcx Mod<'tcx>, Span, HirId) {

compiler/rustc_passes/src/check_attr.rs

@@ -246,7 +246,6 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                     | AttributeKind::Repr { .. }
                     | AttributeKind::Cold(..)
                     | AttributeKind::ExportName { .. }
-                    | AttributeKind::CoherenceIsCore
                     | AttributeKind::Fundamental
                     | AttributeKind::Optimize(..)
                     | AttributeKind::LinkSection { .. }
@@ -278,6 +277,7 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                     | AttributeKind::NoStd { .. }
                     | AttributeKind::ObjcClass { .. }
                     | AttributeKind::ObjcSelector { .. }
+                    | AttributeKind::RustcCoherenceIsCore(..)
                 ) => { /* do nothing  */ }
                 Attribute::Unparsed(attr_item) => {
                     style = Some(attr_item.style);

library/alloc/src/boxed.rs

@@ -640,7 +640,7 @@ impl<T> Box<[T]> {
     /// values[0].write(1);
     /// values[1].write(2);
     /// values[2].write(3);
-    /// let values = unsafe {values.assume_init() };
+    /// let values = unsafe { values.assume_init() };
     ///
     /// assert_eq!(*values, [1, 2, 3])
     /// ```

src/bootstrap/bootstrap.py

@@ -1193,16 +1193,16 @@ def get_latest_commit(self):
             return "<commit>"
         cmd = [
             "git",
-            "-C",
-            repo_path,
             "rev-list",
             "--author",
             author_email,
             "-n1",
             "HEAD",
         ]
         try:
-            commit = subprocess.check_output(cmd, universal_newlines=True).strip()
+            commit = subprocess.check_output(
+                cmd, universal_newlines=True, cwd=repo_path
+            ).strip()
             return commit or "<commit>"
         except subprocess.CalledProcessError:
             return "<commit>"

src/bootstrap/configure.py

@@ -340,6 +340,11 @@ def v(*args):
     "don't truncate options when printing them in this configure script",
 )
 v("set", None, "set arbitrary key/value pairs in TOML configuration")
+v(
+    "parallel-frontend-threads",
+    "rust.parallel-frontend-threads",
+    "number of parallel threads for rustc compilation",
+)
 
 
 def p(msg):

src/bootstrap/src/core/build_steps/compile.rs

@@ -1357,10 +1357,6 @@ pub fn rustc_cargo_env(builder: &Builder<'_>, cargo: &mut Cargo, target: TargetS
         cargo.env("RUSTC_VERIFY_LLVM_IR", "1");
     }
 
-    if builder.config.llvm_enzyme {
-        cargo.rustflag("--cfg=llvm_enzyme");
-    }
-
     // These conditionals represent a tension between three forces:
     // - For non-check builds, we need to define some LLVM-related environment
     //   variables, requiring LLVM to have been built.

src/bootstrap/src/core/builder/cargo.rs

@@ -679,6 +679,12 @@ impl Builder<'_> {
         // cargo would implicitly add it, it was discover that sometimes bootstrap only use
         // `rustflags` without `cargo` making it required.
         rustflags.arg("-Zunstable-options");
+
+        // Add parallel frontend threads configuration
+        if let Some(threads) = self.config.rust_parallel_frontend_threads {
+            rustflags.arg(&format!("-Zthreads={threads}"));
+        }
+
         for (restricted_mode, name, values) in EXTRA_CHECK_CFGS {
             if restricted_mode.is_none() || *restricted_mode == Some(mode) {
                 rustflags.arg(&check_cfg_arg(name, *values));

src/bootstrap/src/core/config/config.rs

@@ -191,7 +191,6 @@ pub struct Config {
     pub rust_optimize: RustOptimize,
     pub rust_codegen_units: Option<u32>,
     pub rust_codegen_units_std: Option<u32>,
-
     pub rustc_debug_assertions: bool,
     pub std_debug_assertions: bool,
     pub tools_debug_assertions: bool,
@@ -222,6 +221,8 @@ pub struct Config {
     pub rust_validate_mir_opts: Option<u32>,
     pub rust_std_features: BTreeSet<String>,
     pub rust_break_on_ice: bool,
+    pub rust_parallel_frontend_threads: Option<u32>,
+
     pub llvm_profile_use: Option<String>,
     pub llvm_profile_generate: bool,
     pub llvm_libunwind_default: Option<LlvmLibunwind>,
@@ -534,6 +535,7 @@ impl Config {
             backtrace_on_ice: rust_backtrace_on_ice,
             verify_llvm_ir: rust_verify_llvm_ir,
             thin_lto_import_instr_limit: rust_thin_lto_import_instr_limit,
+            parallel_frontend_threads: rust_parallel_frontend_threads,
             remap_debuginfo: rust_remap_debuginfo,
             jemalloc: rust_jemalloc,
             test_compare_mode: rust_test_compare_mode,
@@ -1298,6 +1300,7 @@ impl Config {
             rust_overflow_checks_std: rust_overflow_checks_std
                 .or(rust_overflow_checks)
                 .unwrap_or(rust_debug == Some(true)),
+            rust_parallel_frontend_threads: rust_parallel_frontend_threads.map(threads_from_config),
             rust_profile_generate: flags_rust_profile_generate.or(rust_profile_generate),
             rust_profile_use: flags_rust_profile_use.or(rust_profile_use),
             rust_randomize_layout: rust_randomize_layout.unwrap_or(false),