Rollup of 13 pull requests

compiler/rustc_borrowck/src/type_check/input_output.rs

@@ -7,13 +7,16 @@
 //! `RETURN_PLACE` the MIR arguments) are always fully normalized (and
 //! contain revealed `impl Trait` values).
 
+use crate::type_check::constraint_conversion::ConstraintConversion;
 use rustc_index::vec::Idx;
 use rustc_infer::infer::LateBoundRegionConversionTime;
 use rustc_middle::mir::*;
-use rustc_middle::traits::ObligationCause;
-use rustc_middle::ty::{self, Ty};
+use rustc_middle::ty::Ty;
 use rustc_span::Span;
-use rustc_trait_selection::traits::query::normalize::AtExt;
+use rustc_span::DUMMY_SP;
+use rustc_trait_selection::traits::query::type_op::{self, TypeOp};
+use rustc_trait_selection::traits::query::Fallible;
+use type_op::TypeOpOutput;
 
 use crate::universal_regions::UniversalRegions;
 
@@ -30,6 +33,9 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
         let (&normalized_output_ty, normalized_input_tys) =
             normalized_inputs_and_output.split_last().unwrap();
 
+        debug!(?normalized_output_ty);
+        debug!(?normalized_input_tys);
+
         let mir_def_id = body.source.def_id().expect_local();
 
         // If the user explicitly annotated the input types, extract
@@ -75,10 +81,12 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                     .delay_span_bug(body.span, "found more normalized_input_ty than local_decls");
                 break;
             }
+
             // In MIR, argument N is stored in local N+1.
             let local = Local::new(argument_index + 1);
 
             let mir_input_ty = body.local_decls[local].ty;
+
             let mir_input_span = body.local_decls[local].source_info.span;
             self.equate_normalized_input_or_output(
                 normalized_input_ty,
@@ -100,6 +108,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                 // If the user explicitly annotated the input types, enforce those.
                 let user_provided_input_ty =
                     self.normalize(user_provided_input_ty, Locations::All(mir_input_span));
+
                 self.equate_normalized_input_or_output(
                     user_provided_input_ty,
                     mir_input_ty,
@@ -167,30 +176,14 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
             // `rustc_traits::normalize_after_erasing_regions`. Ideally, we'd
             // like to normalize *before* inserting into `local_decls`, but
             // doing so ends up causing some other trouble.
-            let b = match self
-                .infcx
-                .at(&ObligationCause::dummy(), ty::ParamEnv::empty())
-                .normalize(b)
-            {
-                Ok(n) => {
-                    debug!("equate_inputs_and_outputs: {:?}", n);
-                    if n.obligations.iter().all(|o| {
-                        matches!(
-                            o.predicate.kind().skip_binder(),
-                            ty::PredicateKind::RegionOutlives(_)
-                                | ty::PredicateKind::TypeOutlives(_)
-                        )
-                    }) {
-                        n.value
-                    } else {
-                        b
-                    }
-                }
+            let b = match self.normalize_and_add_constraints(b) {
+                Ok(n) => n,
                 Err(_) => {
                     debug!("equate_inputs_and_outputs: NoSolution");
                     b
                 }
             };
+
             // Note: if we have to introduce new placeholders during normalization above, then we won't have
             // added those universes to the universe info, which we would want in `relate_tys`.
             if let Err(terr) =
@@ -207,4 +200,27 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
             }
         }
     }
+
+    pub(crate) fn normalize_and_add_constraints(&mut self, t: Ty<'tcx>) -> Fallible<Ty<'tcx>> {
+        let TypeOpOutput { output: norm_ty, constraints, .. } =
+            self.param_env.and(type_op::normalize::Normalize::new(t)).fully_perform(self.infcx)?;
+
+        debug!("{:?} normalized to {:?}", t, norm_ty);
+
+        for data in constraints.into_iter().collect::<Vec<_>>() {
+            ConstraintConversion::new(
+                self.infcx,
+                &self.borrowck_context.universal_regions,
+                &self.region_bound_pairs,
+                Some(self.implicit_region_bound),
+                self.param_env,
+                Locations::All(DUMMY_SP),
+                ConstraintCategory::Internal,
+                &mut self.borrowck_context.constraints,
+            )
+            .convert_all(&*data);
+        }
+
+        Ok(norm_ty)
+    }
 }

compiler/rustc_borrowck/src/type_check/mod.rs

@@ -893,11 +893,11 @@ struct TypeChecker<'a, 'tcx> {
 }
 
 struct BorrowCheckContext<'a, 'tcx> {
-    universal_regions: &'a UniversalRegions<'tcx>,
+    pub(crate) universal_regions: &'a UniversalRegions<'tcx>,
     location_table: &'a LocationTable,
     all_facts: &'a mut Option<AllFacts>,
     borrow_set: &'a BorrowSet<'tcx>,
-    constraints: &'a mut MirTypeckRegionConstraints<'tcx>,
+    pub(crate) constraints: &'a mut MirTypeckRegionConstraints<'tcx>,
     upvars: &'a [Upvar<'tcx>],
 }
 
@@ -1157,6 +1157,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
         self.relate_types(sup, ty::Variance::Contravariant, sub, locations, category)
     }
 
+    #[instrument(skip(self, category), level = "debug")]
     fn eq_types(
         &mut self,
         expected: Ty<'tcx>,

compiler/rustc_codegen_gcc/src/intrinsic/mod.rs

@@ -316,7 +316,7 @@ impl<'a, 'gcc, 'tcx> IntrinsicCallMethods<'tcx> for Builder<'a, 'gcc, 'tcx> {
                     extended_asm.add_input_operand(None, "r", result.llval);
                     extended_asm.add_clobber("memory");
                     extended_asm.set_volatile_flag(true);
-                    
+
                     // We have copied the value to `result` already.
                     return;
                 }
@@ -363,10 +363,6 @@ impl<'a, 'gcc, 'tcx> IntrinsicCallMethods<'tcx> for Builder<'a, 'gcc, 'tcx> {
         cond
     }
 
-    fn sideeffect(&mut self) {
-        // TODO(antoyo)
-    }
-
     fn type_test(&mut self, _pointer: Self::Value, _typeid: Self::Value) -> Self::Value {
         // Unsupported.
         self.context.new_rvalue_from_int(self.int_type, 0)

compiler/rustc_codegen_llvm/src/context.rs

@@ -597,7 +597,6 @@ impl CodegenCx<'b, 'tcx> {
         ifn!("llvm.trap", fn() -> void);
         ifn!("llvm.debugtrap", fn() -> void);
         ifn!("llvm.frameaddress", fn(t_i32) -> i8p);
-        ifn!("llvm.sideeffect", fn() -> void);
 
         ifn!("llvm.powi.f32", fn(t_f32, t_i32) -> t_f32);
         ifn!("llvm.powi.f64", fn(t_f64, t_i32) -> t_f64);

compiler/rustc_codegen_llvm/src/intrinsic.rs

@@ -392,15 +392,6 @@ impl IntrinsicCallMethods<'tcx> for Builder<'a, 'll, 'tcx> {
         self.call_intrinsic("llvm.expect.i1", &[cond, self.const_bool(expected)])
     }
 
-    fn sideeffect(&mut self) {
-        // This kind of check would make a ton of sense in the caller, but currently the only
-        // caller of this function is in `rustc_codegen_ssa`, which is agnostic to whether LLVM
-        // codegen backend being used, and so is unable to check the LLVM version.
-        if unsafe { llvm::LLVMRustVersionMajor() } < 12 {
-            self.call_intrinsic("llvm.sideeffect", &[]);
-        }
-    }
-
     fn type_test(&mut self, pointer: Self::Value, typeid: Self::Value) -> Self::Value {
         // Test the called operand using llvm.type.test intrinsic. The LowerTypeTests link-time
         // optimization pass replaces calls to this intrinsic with code to test type membership.

compiler/rustc_codegen_ssa/src/back/link.rs

@@ -1034,15 +1034,25 @@ fn link_natively<'a, B: ArchiveBuilder<'a>>(
         SplitDebuginfo::Packed => link_dwarf_object(sess, &out_filename),
     }
 
+    let strip = strip_value(sess);
+
     if sess.target.is_like_osx {
-        match sess.opts.debugging_opts.strip {
+        match strip {
             Strip::Debuginfo => strip_symbols_in_osx(sess, &out_filename, Some("-S")),
             Strip::Symbols => strip_symbols_in_osx(sess, &out_filename, None),
             Strip::None => {}
         }
     }
 }
 
+// Temporarily support both -Z strip and -C strip
+fn strip_value(sess: &Session) -> Strip {
+    match (sess.opts.debugging_opts.strip, sess.opts.cg.strip) {
+        (s, Strip::None) => s,
+        (_, s) => s,
+    }
+}
+
 fn strip_symbols_in_osx<'a>(sess: &'a Session, out_filename: &Path, option: Option<&str>) {
     let mut cmd = Command::new("strip");
     if let Some(option) = option {
@@ -2014,7 +2024,7 @@ fn add_order_independent_options(
     cmd.optimize();
 
     // Pass debuginfo and strip flags down to the linker.
-    cmd.debuginfo(sess.opts.debugging_opts.strip);
+    cmd.debuginfo(strip_value(sess));
 
     // We want to prevent the compiler from accidentally leaking in any system libraries,
     // so by default we tell linkers not to link to any default libraries.

compiler/rustc_codegen_ssa/src/mir/block.rs

@@ -980,17 +980,6 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
             }
 
             mir::TerminatorKind::Goto { target } => {
-                if bb == target {
-                    // This is an unconditional branch back to this same basic block. That means we
-                    // have something like a `loop {}` statement. LLVM versions before 12.0
-                    // miscompile this because they assume forward progress. For older versions
-                    // try to handle just this specific case which comes up commonly in practice
-                    // (e.g., in embedded code).
-                    //
-                    // NB: the `sideeffect` currently checks for the LLVM version used internally.
-                    bx.sideeffect();
-                }
-
                 helper.funclet_br(self, &mut bx, target);
             }
 

compiler/rustc_codegen_ssa/src/traits/intrinsic.rs

@@ -20,10 +20,6 @@ pub trait IntrinsicCallMethods<'tcx>: BackendTypes {
     fn abort(&mut self);
     fn assume(&mut self, val: Self::Value);
     fn expect(&mut self, cond: Self::Value, expected: bool) -> Self::Value;
-    /// Emits a forced side effect.
-    ///
-    /// Currently has any effect only when LLVM versions prior to 12.0 are used as the backend.
-    fn sideeffect(&mut self);
     /// Trait method used to test whether a given pointer is associated with a type identifier.
     fn type_test(&mut self, pointer: Self::Value, typeid: Self::Value) -> Self::Value;
     /// Trait method used to inject `va_start` on the "spoofed" `VaListImpl` in

compiler/rustc_const_eval/src/interpret/memory.rs

@@ -1057,20 +1057,19 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> Memory<'mir, 'tcx, M> {
             Some(dest_ptr) => dest_ptr,
         };
 
+        // This checks relocation edges on the src, which needs to happen before
+        // `prepare_relocation_copy`.
+        let src_bytes = src_alloc
+            .get_bytes_with_uninit_and_ptr(&tcx, src_range)
+            .map_err(|e| e.to_interp_error(src_alloc_id))?
+            .as_ptr(); // raw ptr, so we can also get a ptr to the destination allocation
         // first copy the relocations to a temporary buffer, because
         // `get_bytes_mut` will clear the relocations, which is correct,
         // since we don't want to keep any relocations at the target.
-        // (`get_bytes_with_uninit_and_ptr` below checks that there are no
-        // relocations overlapping the edges; those would not be handled correctly).
         let relocations =
             src_alloc.prepare_relocation_copy(self, src_range, dest_offset, num_copies);
         // Prepare a copy of the initialization mask.
         let compressed = src_alloc.compress_uninit_range(src_range);
-        // This checks relocation edges on the src.
-        let src_bytes = src_alloc
-            .get_bytes_with_uninit_and_ptr(&tcx, src_range)
-            .map_err(|e| e.to_interp_error(src_alloc_id))?
-            .as_ptr(); // raw ptr, so we can also get a ptr to the destination allocation
 
         // Destination alloc preparations and access hooks.
         let (dest_alloc, extra) = self.get_raw_mut(dest_alloc_id)?;

compiler/rustc_infer/src/traits/util.rs

@@ -5,6 +5,7 @@ use crate::traits::{Obligation, ObligationCause, PredicateObligation};
 use rustc_data_structures::fx::{FxHashSet, FxIndexSet};
 use rustc_middle::ty::{self, ToPredicate, TyCtxt, WithConstness};
 use rustc_span::symbol::Ident;
+use rustc_span::Span;
 
 pub fn anonymize_predicate<'tcx>(
     tcx: TyCtxt<'tcx>,
@@ -97,6 +98,22 @@ pub fn elaborate_predicates<'tcx>(
     elaborate_obligations(tcx, obligations)
 }
 
+pub fn elaborate_predicates_with_span<'tcx>(
+    tcx: TyCtxt<'tcx>,
+    predicates: impl Iterator<Item = (ty::Predicate<'tcx>, Span)>,
+) -> Elaborator<'tcx> {
+    let obligations = predicates
+        .map(|(predicate, span)| {
+            predicate_obligation(
+                predicate,
+                ty::ParamEnv::empty(),
+                ObligationCause::dummy_with_span(span),
+            )
+        })
+        .collect();
+    elaborate_obligations(tcx, obligations)
+}
+
 pub fn elaborate_obligations<'tcx>(
     tcx: TyCtxt<'tcx>,
     mut obligations: Vec<PredicateObligation<'tcx>>,

compiler/rustc_interface/src/tests.rs

@@ -551,6 +551,7 @@ fn test_codegen_options_tracking_hash() {
     untracked!(remark, Passes::Some(vec![String::from("pass1"), String::from("pass2")]));
     untracked!(rpath, true);
     untracked!(save_temps, true);
+    untracked!(strip, Strip::Debuginfo);
 
     macro_rules! tracked {
         ($name: ident, $non_default_value: expr) => {
@@ -684,7 +685,6 @@ fn test_debugging_options_tracking_hash() {
     untracked!(self_profile_events, Some(vec![String::new()]));
     untracked!(span_debug, true);
     untracked!(span_free_formats, true);
-    untracked!(strip, Strip::Debuginfo);
     untracked!(temps_dir, Some(String::from("abc")));
     untracked!(terminal_width, Some(80));
     untracked!(threads, 99);

compiler/rustc_middle/src/ty/sty.rs

@@ -2067,7 +2067,9 @@ impl<'tcx> TyS<'tcx> {
     ) -> Option<Discr<'tcx>> {
         match self.kind() {
             TyKind::Adt(adt, _) if adt.variants.is_empty() => {
-                bug!("discriminant_for_variant called on zero variant enum");
+                // This can actually happen during CTFE, see
+                // https://github.com/rust-lang/rust/issues/89765.
+                None
             }
             TyKind::Adt(adt, _) if adt.is_enum() => {
                 Some(adt.discriminant_for_variant(tcx, variant_index))

compiler/rustc_parse/src/lexer/unescape_error_reporting.rs

@@ -82,6 +82,33 @@ pub(crate) fn emit_unescape_error(
                         Applicability::MachineApplicable,
                     );
                 }
+            } else {
+                let printable: Vec<char> = lit
+                    .chars()
+                    .filter(|&x| {
+                        unicode_width::UnicodeWidthChar::width(x).unwrap_or(0) != 0
+                            && !x.is_whitespace()
+                    })
+                    .collect();
+
+                if let [ch] = printable.as_slice() {
+                    has_help = true;
+
+                    handler.span_note(
+                        span,
+                        &format!(
+                            "there are non-printing characters, the full sequence is `{}`",
+                            lit.escape_default(),
+                        ),
+                    );
+
+                    handler.span_suggestion(
+                        span,
+                        "consider removing the non-printing characters",
+                        ch.to_string(),
+                        Applicability::MaybeIncorrect,
+                    );
+                }
             }
 
             if !has_help {