Merge from rustc

Author: RalfJung

RELEASES.md

@@ -1481,7 +1481,7 @@ and related tools.
 [is_power_of_two_usize]: https://doc.rust-lang.org/stable/core/num/struct.NonZeroUsize.html#method.is_power_of_two
 [stdarch/1266]: https://github.com/rust-lang/stdarch/pull/1266
 
-Version 1.58.1 (2022-01-19)
+Version 1.58.1 (2022-01-20)
 ===========================
 
 * Fix race condition in `std::fs::remove_dir_all` ([CVE-2022-21658])

compiler/rustc_builtin_macros/src/deriving/bounds.rs

@@ -27,3 +27,26 @@ pub fn expand_deriving_copy(
 
     trait_def.expand(cx, mitem, item, push);
 }
+
+pub fn expand_deriving_const_param_ty(
+    cx: &mut ExtCtxt<'_>,
+    span: Span,
+    mitem: &MetaItem,
+    item: &Annotatable,
+    push: &mut dyn FnMut(Annotatable),
+    is_const: bool,
+) {
+    let trait_def = TraitDef {
+        span,
+        path: path_std!(marker::ConstParamTy),
+        skip_path_as_bound: false,
+        needs_copy_as_bound_if_packed: false,
+        additional_bounds: Vec::new(),
+        supports_unions: false,
+        methods: Vec::new(),
+        associated_types: Vec::new(),
+        is_const,
+    };
+
+    trait_def.expand(cx, mitem, item, push);
+}

compiler/rustc_builtin_macros/src/lib.rs

@@ -115,6 +115,7 @@ pub fn register_builtin_macros(resolver: &mut dyn ResolverExpand) {
     register_derive! {
         Clone: clone::expand_deriving_clone,
         Copy: bounds::expand_deriving_copy,
+        ConstParamTy: bounds::expand_deriving_const_param_ty,
         Debug: debug::expand_deriving_debug,
         Default: default::expand_deriving_default,
         Eq: eq::expand_deriving_eq,

compiler/rustc_codegen_cranelift/src/base.rs

@@ -966,11 +966,7 @@ fn codegen_panic_inner<'tcx>(
     args: &[Value],
     span: Span,
 ) {
-    let def_id = fx
-        .tcx
-        .lang_items()
-        .require(lang_item)
-        .unwrap_or_else(|e| fx.tcx.sess.span_fatal(span, e.to_string()));
+    let def_id = fx.tcx.require_lang_item(lang_item, Some(span));
 
     let instance = Instance::mono(fx.tcx, def_id).polymorphize(fx.tcx);
     let symbol_name = fx.tcx.symbol_name(instance).name;

compiler/rustc_codegen_llvm/src/back/lto.rs

@@ -25,7 +25,6 @@ use std::fs::File;
 use std::io;
 use std::iter;
 use std::path::Path;
-use std::ptr;
 use std::slice;
 use std::sync::Arc;
 
@@ -709,17 +708,6 @@ pub unsafe fn optimize_thin_module(
         let llmod = module.module_llvm.llmod();
         save_temp_bitcode(cgcx, &module, "thin-lto-input");
 
-        // Before we do much else find the "main" `DICompileUnit` that we'll be
-        // using below. If we find more than one though then rustc has changed
-        // in a way we're not ready for, so generate an ICE by returning
-        // an error.
-        let mut cu1 = ptr::null_mut();
-        let mut cu2 = ptr::null_mut();
-        llvm::LLVMRustThinLTOGetDICompileUnit(llmod, &mut cu1, &mut cu2);
-        if !cu2.is_null() {
-            return Err(write::llvm_err(&diag_handler, LlvmError::MultipleSourceDiCompileUnit));
-        }
-
         // Up next comes the per-module local analyses that we do for Thin LTO.
         // Each of these functions is basically copied from the LLVM
         // implementation and then tailored to suit this implementation. Ideally
@@ -766,43 +754,6 @@ pub unsafe fn optimize_thin_module(
             save_temp_bitcode(cgcx, &module, "thin-lto-after-import");
         }
 
-        // Ok now this is a bit unfortunate. This is also something you won't
-        // find upstream in LLVM's ThinLTO passes! This is a hack for now to
-        // work around bugs in LLVM.
-        //
-        // First discovered in #45511 it was found that as part of ThinLTO
-        // importing passes LLVM will import `DICompileUnit` metadata
-        // information across modules. This means that we'll be working with one
-        // LLVM module that has multiple `DICompileUnit` instances in it (a
-        // bunch of `llvm.dbg.cu` members). Unfortunately there's a number of
-        // bugs in LLVM's backend which generates invalid DWARF in a situation
-        // like this:
-        //
-        //  https://bugs.llvm.org/show_bug.cgi?id=35212
-        //  https://bugs.llvm.org/show_bug.cgi?id=35562
-        //
-        // While the first bug there is fixed the second ended up causing #46346
-        // which was basically a resurgence of #45511 after LLVM's bug 35212 was
-        // fixed.
-        //
-        // This function below is a huge hack around this problem. The function
-        // below is defined in `PassWrapper.cpp` and will basically "merge"
-        // all `DICompileUnit` instances in a module. Basically it'll take all
-        // the objects, rewrite all pointers of `DISubprogram` to point to the
-        // first `DICompileUnit`, and then delete all the other units.
-        //
-        // This is probably mangling to the debug info slightly (but hopefully
-        // not too much) but for now at least gets LLVM to emit valid DWARF (or
-        // so it appears). Hopefully we can remove this once upstream bugs are
-        // fixed in LLVM.
-        {
-            let _timer = cgcx
-                .prof
-                .generic_activity_with_arg("LLVM_thin_lto_patch_debuginfo", thin_module.name());
-            llvm::LLVMRustThinLTOPatchDICompileUnit(llmod, cu1);
-            save_temp_bitcode(cgcx, &module, "thin-lto-after-patch");
-        }
-
         // Alright now that we've done everything related to the ThinLTO
         // analysis it's time to run some optimizations! Here we use the same
         // `run_pass_manager` as the "fat" LTO above except that we tell it to

compiler/rustc_codegen_llvm/src/llvm/ffi.rs

@@ -2484,12 +2484,6 @@ extern "C" {
         len: usize,
         out_len: &mut usize,
     ) -> *const u8;
-    pub fn LLVMRustThinLTOGetDICompileUnit(
-        M: &Module,
-        CU1: &mut *mut c_void,
-        CU2: &mut *mut c_void,
-    );
-    pub fn LLVMRustThinLTOPatchDICompileUnit(M: &Module, CU: *mut c_void);
 
     pub fn LLVMRustLinkerNew(M: &Module) -> &mut Linker<'_>;
     pub fn LLVMRustLinkerAdd(

compiler/rustc_codegen_ssa/src/back/metadata.rs

@@ -14,8 +14,7 @@ use snap::write::FrameEncoder;
 
 use object::elf::NT_GNU_PROPERTY_TYPE_0;
 use rustc_data_structures::memmap::Mmap;
-use rustc_data_structures::owned_slice::try_slice_owned;
-use rustc_data_structures::sync::MetadataRef;
+use rustc_data_structures::owned_slice::{try_slice_owned, OwnedSlice};
 use rustc_metadata::fs::METADATA_FILENAME;
 use rustc_metadata::EncodedMetadata;
 use rustc_session::cstore::MetadataLoader;
@@ -39,7 +38,7 @@ pub struct DefaultMetadataLoader;
 fn load_metadata_with(
     path: &Path,
     f: impl for<'a> FnOnce(&'a [u8]) -> Result<&'a [u8], String>,
-) -> Result<MetadataRef, String> {
+) -> Result<OwnedSlice, String> {
     let file =
         File::open(path).map_err(|e| format!("failed to open file '{}': {}", path.display(), e))?;
 
@@ -49,7 +48,7 @@ fn load_metadata_with(
 }
 
 impl MetadataLoader for DefaultMetadataLoader {
-    fn get_rlib_metadata(&self, _target: &Target, path: &Path) -> Result<MetadataRef, String> {
+    fn get_rlib_metadata(&self, _target: &Target, path: &Path) -> Result<OwnedSlice, String> {
         load_metadata_with(path, |data| {
             let archive = object::read::archive::ArchiveFile::parse(&*data)
                 .map_err(|e| format!("failed to parse rlib '{}': {}", path.display(), e))?;
@@ -69,7 +68,7 @@ impl MetadataLoader for DefaultMetadataLoader {
         })
     }
 
-    fn get_dylib_metadata(&self, _target: &Target, path: &Path) -> Result<MetadataRef, String> {
+    fn get_dylib_metadata(&self, _target: &Target, path: &Path) -> Result<OwnedSlice, String> {
         load_metadata_with(path, |data| search_for_section(path, data, ".rustc"))
     }
 }

compiler/rustc_codegen_ssa/src/traits/backend.rs

@@ -1,10 +1,13 @@
+use std::any::Any;
+
 use super::write::WriteBackendMethods;
 use super::CodegenObject;
 use crate::back::write::TargetMachineFactoryFn;
 use crate::{CodegenResults, ModuleCodegen};
 
 use rustc_ast::expand::allocator::AllocatorKind;
 use rustc_data_structures::fx::FxHashMap;
+use rustc_data_structures::sync::{DynSend, DynSync};
 use rustc_errors::ErrorGuaranteed;
 use rustc_metadata::EncodedMetadata;
 use rustc_middle::dep_graph::{WorkProduct, WorkProductId};
@@ -20,11 +23,6 @@ use rustc_span::symbol::Symbol;
 use rustc_target::abi::call::FnAbi;
 use rustc_target::spec::Target;
 
-pub use rustc_data_structures::sync::MetadataRef;
-
-use rustc_data_structures::sync::{DynSend, DynSync};
-use std::any::Any;
-
 pub trait BackendTypes {
     type Value: CodegenObject;
     type Function: CodegenObject;

compiler/rustc_const_eval/src/const_eval/error.rs

@@ -3,7 +3,8 @@ use std::fmt;
 
 use rustc_errors::Diagnostic;
 use rustc_middle::mir::AssertKind;
-use rustc_middle::ty::{layout::LayoutError, query::TyCtxtAt, ConstInt};
+use rustc_middle::query::TyCtxtAt;
+use rustc_middle::ty::{layout::LayoutError, ConstInt};
 use rustc_span::{Span, Symbol};
 
 use super::InterpCx;
@@ -169,14 +170,14 @@ impl<'tcx> ConstEvalErr<'tcx> {
                 // See <https://github.com/rust-lang/rust/pull/63152>.
                 let mut err = struct_error(tcx, &self.error.to_string());
                 self.decorate(&mut err, decorate);
-                ErrorHandled::Reported(err.emit())
+                ErrorHandled::Reported(err.emit().into())
             }
             _ => {
                 // Report as hard error.
                 let mut err = struct_error(tcx, message);
                 err.span_label(self.span, self.error.to_string());
                 self.decorate(&mut err, decorate);
-                ErrorHandled::Reported(err.emit())
+                ErrorHandled::Reported(err.emit().into())
             }
         }
     }

compiler/rustc_const_eval/src/const_eval/machine.rs

@@ -382,7 +382,7 @@ impl<'mir, 'tcx> interpret::Machine<'mir, 'tcx> for CompileTimeInterpreter<'mir,
                         rustc_span::DUMMY_SP,
                         "This is likely a const item that is missing from its impl",
                     );
-                    throw_inval!(AlreadyReported(guar));
+                    throw_inval!(AlreadyReported(guar.into()));
                 } else {
                     // `find_mir_or_eval_fn` checks that this is a const fn before even calling us,
                     // so this should be unreachable.

compiler/rustc_const_eval/src/interpret/eval_context.rs

@@ -7,14 +7,13 @@ use either::{Either, Left, Right};
 use rustc_hir::{self as hir, def_id::DefId, definitions::DefPathData};
 use rustc_index::IndexVec;
 use rustc_middle::mir;
-use rustc_middle::mir::interpret::{ErrorHandled, InterpError};
+use rustc_middle::mir::interpret::{ErrorHandled, InterpError, ReportedErrorInfo};
+use rustc_middle::query::TyCtxtAt;
 use rustc_middle::ty::layout::{
     self, FnAbiError, FnAbiOfHelpers, FnAbiRequest, LayoutError, LayoutOf, LayoutOfHelpers,
     TyAndLayout,
 };
-use rustc_middle::ty::{
-    self, query::TyCtxtAt, subst::SubstsRef, ParamEnv, Ty, TyCtxt, TypeFoldable,
-};
+use rustc_middle::ty::{self, subst::SubstsRef, ParamEnv, Ty, TyCtxt, TypeFoldable};
 use rustc_mir_dataflow::storage::always_storage_live_locals;
 use rustc_session::Limit;
 use rustc_span::Span;
@@ -470,7 +469,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
         };
         // do not continue if typeck errors occurred (can only occur in local crate)
         if let Some(err) = body.tainted_by_errors {
-            throw_inval!(AlreadyReported(err));
+            throw_inval!(AlreadyReported(ReportedErrorInfo::tainted_by_errors(err)));
         }
         Ok(body)
     }
@@ -517,7 +516,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
             Ok(None) => throw_inval!(TooGeneric),
 
             // FIXME(eddyb) this could be a bit more specific than `AlreadyReported`.
-            Err(error_reported) => throw_inval!(AlreadyReported(error_reported)),
+            Err(error_reported) => throw_inval!(AlreadyReported(error_reported.into())),
         }
     }
 
@@ -905,7 +904,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
         query(self.tcx.at(span.unwrap_or_else(|| self.cur_span()))).map_err(|err| {
             match err {
                 ErrorHandled::Reported(err) => {
-                    if let Some(span) = span {
+                    if !err.is_tainted_by_errors() && let Some(span) = span {
                         // To make it easier to figure out where this error comes from, also add a note at the current location.
                         self.tcx.sess.span_note_without_error(span, "erroneous constant used");
                     }

compiler/rustc_const_eval/src/interpret/operand.rs

@@ -595,7 +595,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
             // FIXME(generic_const_exprs): `ConstKind::Expr` should be able to be evaluated
             ty::ConstKind::Expr(_) => throw_inval!(TooGeneric),
             ty::ConstKind::Error(reported) => {
-                throw_inval!(AlreadyReported(reported))
+                throw_inval!(AlreadyReported(reported.into()))
             }
             ty::ConstKind::Unevaluated(uv) => {
                 let instance = self.resolve(uv.def, uv.substs)?;

compiler/rustc_data_structures/src/owned_slice.rs

@@ -1,13 +1,14 @@
 use std::{borrow::Borrow, ops::Deref};
 
+use crate::sync::Lrc;
 // Use our fake Send/Sync traits when on not parallel compiler,
 // so that `OwnedSlice` only implements/requires Send/Sync
 // for parallel compiler builds.
 use crate::sync::{Send, Sync};
 
 /// An owned slice.
 ///
-/// This is similar to `Box<[u8]>` but allows slicing and using anything as the
+/// This is similar to `Lrc<[u8]>` but allows slicing and using anything as the
 /// backing buffer.
 ///
 /// See [`slice_owned`] for `OwnedSlice` construction and examples.
@@ -16,6 +17,7 @@ use crate::sync::{Send, Sync};
 ///
 /// This is essentially a replacement for `owning_ref` which is a lot simpler
 /// and even sound! 🌸
+#[derive(Clone)]
 pub struct OwnedSlice {
     /// This is conceptually a `&'self.owner [u8]`.
     bytes: *const [u8],
@@ -31,7 +33,7 @@ pub struct OwnedSlice {
     //       \/
     //      ⊂(´･◡･⊂ )∘˚˳° (I am the phantom remnant of #97770)
     #[expect(dead_code)]
-    owner: Box<dyn Send + Sync>,
+    owner: Lrc<dyn Send + Sync>,
 }
 
 /// Makes an [`OwnedSlice`] out of an `owner` and a `slicer` function.
@@ -72,23 +74,50 @@ where
     O: Send + Sync + 'static,
     F: FnOnce(&O) -> Result<&[u8], E>,
 {
-    // We box the owner of the bytes, so it doesn't move.
+    // We wrap the owner of the bytes in, so it doesn't move.
     //
     // Since the owner does not move and we don't access it in any way
-    // before drop, there is nothing that can invalidate the bytes pointer.
+    // before dropping, there is nothing that can invalidate the bytes pointer.
     //
     // Thus, "extending" the lifetime of the reference returned from `F` is fine.
     // We pretend that we pass it a reference that lives as long as the returned slice.
     //
     // N.B. the HRTB on the `slicer` is important — without it the caller could provide
     // a short lived slice, unrelated to the owner.
 
-    let owner = Box::new(owner);
+    let owner = Lrc::new(owner);
     let bytes = slicer(&*owner)?;
 
     Ok(OwnedSlice { bytes, owner })
 }
 
+impl OwnedSlice {
+    /// Slice this slice by `slicer`.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use rustc_data_structures::owned_slice::{OwnedSlice, slice_owned};
+    /// let vec = vec![1, 2, 3, 4];
+    ///
+    /// // Identical to slicing via `&v[1..3]` but produces an owned slice
+    /// let slice: OwnedSlice = slice_owned(vec, |v| &v[..]);
+    /// assert_eq!(&*slice, [1, 2, 3, 4]);
+    ///
+    /// let slice = slice.slice(|slice| &slice[1..][..2]);
+    /// assert_eq!(&*slice, [2, 3]);
+    /// ```
+    ///
+    pub fn slice(self, slicer: impl FnOnce(&[u8]) -> &[u8]) -> OwnedSlice {
+        // This is basically identical to `try_slice_owned`,
+        // `slicer` can only return slices of its argument or some static data,
+        // both of which are valid while `owner` is alive.
+
+        let bytes = slicer(&self);
+        OwnedSlice { bytes, ..self }
+    }
+}
+
 impl Deref for OwnedSlice {
     type Target = [u8];
 
@@ -108,11 +137,11 @@ impl Borrow<[u8]> for OwnedSlice {
     }
 }
 
-// Safety: `OwnedSlice` is conceptually `(&'self.1 [u8], Box<dyn Send + Sync>)`, which is `Send`
+// Safety: `OwnedSlice` is conceptually `(&'self.1 [u8], Arc<dyn Send + Sync>)`, which is `Send`
 #[cfg(parallel_compiler)]
 unsafe impl Send for OwnedSlice {}
 
-// Safety: `OwnedSlice` is conceptually `(&'self.1 [u8], Box<dyn Send + Sync>)`, which is `Sync`
+// Safety: `OwnedSlice` is conceptually `(&'self.1 [u8], Arc<dyn Send + Sync>)`, which is `Sync`
 #[cfg(parallel_compiler)]
 unsafe impl Sync for OwnedSlice {}