Rollup of 9 pull requests

compiler/rustc_abi/src/lib.rs

@@ -638,7 +638,7 @@ impl AddAssign for Size {
 #[cfg(feature = "nightly")]
 impl Step for Size {
     #[inline]
-    fn steps_between(start: &Self, end: &Self) -> Option<usize> {
+    fn steps_between(start: &Self, end: &Self) -> (usize, Option<usize>) {
         u64::steps_between(&start.bytes(), &end.bytes())
     }
 

compiler/rustc_index_macros/src/newtype.rs

@@ -122,7 +122,7 @@ impl Parse for Newtype {
                 #gate_rustc_only
                 impl ::std::iter::Step for #name {
                     #[inline]
-                    fn steps_between(start: &Self, end: &Self) -> Option<usize> {
+                    fn steps_between(start: &Self, end: &Self) -> (usize, Option<usize>) {
                         <usize as ::std::iter::Step>::steps_between(
                             &Self::index(*start),
                             &Self::index(*end),

compiler/rustc_resolve/src/late.rs

@@ -3940,12 +3940,12 @@ impl<'a, 'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'a, 'ast, 'ra, 'tcx> {
             }
             Res::SelfCtor(_) => {
                 // We resolve `Self` in pattern position as an ident sometimes during recovery,
-                // so delay a bug instead of ICEing. (Note: is this no longer true? We now ICE. If
-                // this triggers, please convert to a delayed bug and add a test.)
-                self.r.dcx().span_bug(
+                // so delay a bug instead of ICEing.
+                self.r.dcx().span_delayed_bug(
                     ident.span,
                     "unexpected `SelfCtor` in pattern, expected identifier"
                 );
+                None
             }
             _ => span_bug!(
                 ident.span,

compiler/rustc_session/src/options.rs

@@ -358,7 +358,7 @@ fn build_options<O: Default>(
 
 #[allow(non_upper_case_globals)]
 mod desc {
-    pub(crate) const parse_no_flag: &str = "no value";
+    pub(crate) const parse_no_value: &str = "no value";
     pub(crate) const parse_bool: &str =
         "one of: `y`, `yes`, `on`, `true`, `n`, `no`, `off` or `false`";
     pub(crate) const parse_opt_bool: &str = parse_bool;
@@ -462,14 +462,18 @@ pub mod parse {
     pub(crate) use super::*;
     pub(crate) const MAX_THREADS_CAP: usize = 256;
 
-    /// This is for boolean options that don't take a value and start with
-    /// `no-`. This style of option is deprecated.
-    pub(crate) fn parse_no_flag(slot: &mut bool, v: Option<&str>) -> bool {
+    /// This is for boolean options that don't take a value, and are true simply
+    /// by existing on the command-line.
+    ///
+    /// This style of option is deprecated, and is mainly used by old options
+    /// beginning with `no-`.
+    pub(crate) fn parse_no_value(slot: &mut bool, v: Option<&str>) -> bool {
         match v {
             None => {
                 *slot = true;
                 true
             }
+            // Trying to specify a value is always forbidden.
             Some(_) => false,
         }
     }
@@ -1609,16 +1613,16 @@ options! {
         "perform LLVM link-time optimizations"),
     metadata: Vec<String> = (Vec::new(), parse_list, [TRACKED],
         "metadata to mangle symbol names with"),
-    no_prepopulate_passes: bool = (false, parse_no_flag, [TRACKED],
+    no_prepopulate_passes: bool = (false, parse_no_value, [TRACKED],
         "give an empty list of passes to the pass manager"),
     no_redzone: Option<bool> = (None, parse_opt_bool, [TRACKED],
         "disable the use of the redzone"),
     #[rustc_lint_opt_deny_field_access("documented to do nothing")]
-    no_stack_check: bool = (false, parse_no_flag, [UNTRACKED],
+    no_stack_check: bool = (false, parse_no_value, [UNTRACKED],
         "this option is deprecated and does nothing"),
-    no_vectorize_loops: bool = (false, parse_no_flag, [TRACKED],
+    no_vectorize_loops: bool = (false, parse_no_value, [TRACKED],
         "disable loop vectorization optimization passes"),
-    no_vectorize_slp: bool = (false, parse_no_flag, [TRACKED],
+    no_vectorize_slp: bool = (false, parse_no_value, [TRACKED],
         "disable LLVM's SLP vectorization pass"),
     opt_level: String = ("0".to_string(), parse_string, [TRACKED],
         "optimization level (0-3, s, or z; default: 0)"),
@@ -1915,25 +1919,25 @@ options! {
         "dump facts from NLL analysis into side files (default: no)"),
     nll_facts_dir: String = ("nll-facts".to_string(), parse_string, [UNTRACKED],
         "the directory the NLL facts are dumped into (default: `nll-facts`)"),
-    no_analysis: bool = (false, parse_no_flag, [UNTRACKED],
+    no_analysis: bool = (false, parse_no_value, [UNTRACKED],
         "parse and expand the source, but run no analysis"),
-    no_codegen: bool = (false, parse_no_flag, [TRACKED_NO_CRATE_HASH],
+    no_codegen: bool = (false, parse_no_value, [TRACKED_NO_CRATE_HASH],
         "run all passes except codegen; no output"),
-    no_generate_arange_section: bool = (false, parse_no_flag, [TRACKED],
+    no_generate_arange_section: bool = (false, parse_no_value, [TRACKED],
         "omit DWARF address ranges that give faster lookups"),
     no_implied_bounds_compat: bool = (false, parse_bool, [TRACKED],
         "disable the compatibility version of the `implied_bounds_ty` query"),
-    no_jump_tables: bool = (false, parse_no_flag, [TRACKED],
+    no_jump_tables: bool = (false, parse_no_value, [TRACKED],
         "disable the jump tables and lookup tables that can be generated from a switch case lowering"),
-    no_leak_check: bool = (false, parse_no_flag, [UNTRACKED],
+    no_leak_check: bool = (false, parse_no_value, [UNTRACKED],
         "disable the 'leak check' for subtyping; unsound, but useful for tests"),
-    no_link: bool = (false, parse_no_flag, [TRACKED],
+    no_link: bool = (false, parse_no_value, [TRACKED],
         "compile without linking"),
-    no_parallel_backend: bool = (false, parse_no_flag, [UNTRACKED],
+    no_parallel_backend: bool = (false, parse_no_value, [UNTRACKED],
         "run LLVM in non-parallel mode (while keeping codegen-units and ThinLTO)"),
-    no_profiler_runtime: bool = (false, parse_no_flag, [TRACKED],
+    no_profiler_runtime: bool = (false, parse_no_value, [TRACKED],
         "prevent automatic injection of the profiler_builtins crate"),
-    no_trait_vptr: bool = (false, parse_no_flag, [TRACKED],
+    no_trait_vptr: bool = (false, parse_no_value, [TRACKED],
         "disable generation of trait vptr in vtable for upcasting"),
     no_unique_section_names: bool = (false, parse_bool, [TRACKED],
         "do not use unique names for text and data sections when -Z function-sections is used"),
@@ -1991,7 +1995,7 @@ options! {
     proc_macro_execution_strategy: ProcMacroExecutionStrategy = (ProcMacroExecutionStrategy::SameThread,
         parse_proc_macro_execution_strategy, [UNTRACKED],
         "how to run proc-macro code (default: same-thread)"),
-    profile_closures: bool = (false, parse_no_flag, [UNTRACKED],
+    profile_closures: bool = (false, parse_no_value, [UNTRACKED],
         "profile size of closures"),
     profile_sample_use: Option<PathBuf> = (None, parse_opt_pathbuf, [TRACKED],
         "use the given `.prof` file for sampled profile-guided optimization (also known as AutoFDO)"),
@@ -2165,8 +2169,14 @@ written to standard error output)"),
         "enable unsound and buggy MIR optimizations (default: no)"),
     /// This name is kind of confusing: Most unstable options enable something themselves, while
     /// this just allows "normal" options to be feature-gated.
+    ///
+    /// The main check for `-Zunstable-options` takes place separately from the
+    /// usual parsing of `-Z` options (see [`crate::config::nightly_options`]),
+    /// so this boolean value is mostly used for enabling unstable _values_ of
+    /// stable options. That separate check doesn't handle boolean values, so
+    /// to avoid an inconsistent state we also forbid them here.
     #[rustc_lint_opt_deny_field_access("use `Session::unstable_options` instead of this field")]
-    unstable_options: bool = (false, parse_bool, [UNTRACKED],
+    unstable_options: bool = (false, parse_no_value, [UNTRACKED],
         "adds unstable command line options to rustc interface (default: no)"),
     use_ctors_section: Option<bool> = (None, parse_opt_bool, [TRACKED],
         "use legacy .ctors section for initializers rather than .init_array"),

compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs

@@ -91,14 +91,6 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
             } else if tcx.is_lang_item(def_id, LangItem::Sized) {
                 // Sized is never implementable by end-users, it is
                 // always automatically computed.
-
-                // FIXME: Consider moving this check to the top level as it
-                // may also be useful for predicates other than `Sized`
-                // Error type cannot possibly implement `Sized` (fixes #123154)
-                if let Err(e) = obligation.predicate.skip_binder().self_ty().error_reported() {
-                    return Err(SelectionError::Overflow(e.into()));
-                }
-
                 let sized_conditions = self.sized_conditions(obligation);
                 self.assemble_builtin_bound_candidates(sized_conditions, &mut candidates);
             } else if tcx.is_lang_item(def_id, LangItem::Unsize) {
@@ -230,13 +222,6 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
     ) -> Result<(), SelectionError<'tcx>> {
         debug!(?stack.obligation);
 
-        // An error type will unify with anything. So, avoid
-        // matching an error type with `ParamCandidate`.
-        // This helps us avoid spurious errors like issue #121941.
-        if stack.obligation.predicate.references_error() {
-            return Ok(());
-        }
-
         let bounds = stack
             .obligation
             .param_env
@@ -563,19 +548,6 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
         obligation: &PolyTraitObligation<'tcx>,
         candidates: &mut SelectionCandidateSet<'tcx>,
     ) {
-        // Essentially any user-written impl will match with an error type,
-        // so creating `ImplCandidates` isn't useful. However, we might
-        // end up finding a candidate elsewhere (e.g. a `BuiltinCandidate` for `Sized`)
-        // This helps us avoid overflow: see issue #72839
-        // Since compilation is already guaranteed to fail, this is just
-        // to try to show the 'nicest' possible errors to the user.
-        // We don't check for errors in the `ParamEnv` - in practice,
-        // it seems to cause us to be overly aggressive in deciding
-        // to give up searching for candidates, leading to spurious errors.
-        if obligation.predicate.references_error() {
-            return;
-        }
-
         let drcx = DeepRejectCtxt::relate_rigid_infer(self.tcx());
         let obligation_args = obligation.predicate.skip_binder().trait_ref.args;
         self.tcx().for_each_relevant_impl(

compiler/rustc_trait_selection/src/traits/select/mod.rs

@@ -2487,10 +2487,6 @@ impl<'tcx> SelectionContext<'_, 'tcx> {
         let impl_args = self.infcx.fresh_args_for_item(obligation.cause.span, impl_def_id);
 
         let trait_ref = impl_trait_header.trait_ref.instantiate(self.tcx(), impl_args);
-        if trait_ref.references_error() {
-            return Err(());
-        }
-
         debug!(?impl_trait_header);
 
         let Normalized { value: impl_trait_ref, obligations: mut nested_obligations } =

compiler/rustc_ty_utils/src/ty.rs

@@ -6,8 +6,7 @@ use rustc_index::bit_set::BitSet;
 use rustc_middle::bug;
 use rustc_middle::query::Providers;
 use rustc_middle::ty::{
-    self, EarlyBinder, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable, TypeVisitableExt,
-    TypeVisitor, Upcast,
+    self, EarlyBinder, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable, TypeVisitor, Upcast,
 };
 use rustc_span::DUMMY_SP;
 use rustc_span::def_id::{CRATE_DEF_ID, DefId, LocalDefId};
@@ -95,9 +94,6 @@ fn adt_sized_constraint<'tcx>(
     let tail_ty = tcx.type_of(tail_def.did).instantiate_identity();
 
     let constraint_ty = sized_constraint_for_ty(tcx, tail_ty)?;
-    if let Err(guar) = constraint_ty.error_reported() {
-        return Some(ty::EarlyBinder::bind(Ty::new_error(tcx, guar)));
-    }
 
     // perf hack: if there is a `constraint_ty: Sized` bound, then we know
     // that the type is sized and do not need to check it on the impl.