Rollup of 11 pull requests

compiler/rustc_errors/src/diagnostic_impls.rs

@@ -58,16 +58,29 @@ macro_rules! into_diagnostic_arg_using_display {
     }
 }
 
+macro_rules! into_diagnostic_arg_for_number {
+    ($( $ty:ty ),+ $(,)?) => {
+        $(
+            impl IntoDiagnosticArg for $ty {
+                fn into_diagnostic_arg(self) -> DiagnosticArgValue<'static> {
+                    // HACK: `FluentNumber` the underline backing struct represent
+                    // numbers using a f64 which can't represent all the i128 numbers
+                    // So in order to be able to use fluent selectors and still
+                    // have all the numbers representable we only convert numbers
+                    // below a certain threshold.
+                    if let Ok(n) = TryInto::<i128>::try_into(self) && n >= -100 && n <= 100 {
+                        DiagnosticArgValue::Number(n)
+                    } else {
+                        self.to_string().into_diagnostic_arg()
+                    }
+                }
+            }
+        )+
+    }
+}
+
 into_diagnostic_arg_using_display!(
     ast::ParamKindOrd,
-    i8,
-    u8,
-    i16,
-    u16,
-    u32,
-    i64,
-    i128,
-    u128,
     std::io::Error,
     Box<dyn std::error::Error>,
     std::num::NonZeroU32,
@@ -82,17 +95,7 @@ into_diagnostic_arg_using_display!(
     ExitStatus,
 );
 
-impl IntoDiagnosticArg for i32 {
-    fn into_diagnostic_arg(self) -> DiagnosticArgValue<'static> {
-        DiagnosticArgValue::Number(self.into())
-    }
-}
-
-impl IntoDiagnosticArg for u64 {
-    fn into_diagnostic_arg(self) -> DiagnosticArgValue<'static> {
-        DiagnosticArgValue::Number(self.into())
-    }
-}
+into_diagnostic_arg_for_number!(i8, u8, i16, u16, i32, u32, i64, u64, i128, u128, isize, usize);
 
 impl IntoDiagnosticArg for bool {
     fn into_diagnostic_arg(self) -> DiagnosticArgValue<'static> {
@@ -154,12 +157,6 @@ impl IntoDiagnosticArg for PathBuf {
     }
 }
 
-impl IntoDiagnosticArg for usize {
-    fn into_diagnostic_arg(self) -> DiagnosticArgValue<'static> {
-        DiagnosticArgValue::Number(self as i128)
-    }
-}
-
 impl IntoDiagnosticArg for PanicStrategy {
     fn into_diagnostic_arg(self) -> DiagnosticArgValue<'static> {
         DiagnosticArgValue::Str(Cow::Owned(self.desc().to_string()))

compiler/rustc_hir_analysis/src/astconv/lint.rs

@@ -132,7 +132,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
                     ],
                     Applicability::MachineApplicable,
                 );
-            } else if diag.is_error() && is_downgradable {
+            } else if is_downgradable {
                 // We'll emit the object safety error already, with a structured suggestion.
                 diag.downgrade_to_delayed_bug();
             }
@@ -158,7 +158,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
             }
             if !is_object_safe {
                 diag.note(format!("`{trait_name}` it is not object safe, so it can't be `dyn`"));
-                if diag.is_error() && is_downgradable {
+                if is_downgradable {
                     // We'll emit the object safety error already, with a structured suggestion.
                     diag.downgrade_to_delayed_bug();
                 }
@@ -241,13 +241,11 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
             } else {
                 let msg = "trait objects without an explicit `dyn` are deprecated";
                 tcx.node_span_lint(BARE_TRAIT_OBJECTS, self_ty.hir_id, self_ty.span, msg, |lint| {
-                    if self_ty.span.can_be_used_for_suggestions()
-                        && !self.maybe_lint_impl_trait(self_ty, lint)
-                    {
+                    if self_ty.span.can_be_used_for_suggestions() {
                         lint.multipart_suggestion_verbose(
                             "use `dyn`",
                             sugg,
-                            Applicability::MachineApplicable,
+                            Applicability::MaybeIncorrect,
                         );
                     }
                     self.maybe_lint_blanket_trait_impl(self_ty, lint);

compiler/rustc_middle/src/middle/region.rs

@@ -221,9 +221,6 @@ pub struct ScopeTree {
     /// variable is declared.
     var_map: FxIndexMap<hir::ItemLocalId, Scope>,
 
-    /// Maps from a `NodeId` to the associated destruction scope (if any).
-    destruction_scopes: FxIndexMap<hir::ItemLocalId, Scope>,
-
     /// Identifies expressions which, if captured into a temporary, ought to
     /// have a temporary whose lifetime extends to the end of the enclosing *block*,
     /// and not the enclosing *statement*. Expressions that are not present in this
@@ -336,11 +333,6 @@ impl ScopeTree {
             let prev = self.parent_map.insert(child, p);
             assert!(prev.is_none());
         }
-
-        // Record the destruction scopes for later so we can query them.
-        if let ScopeData::Destruction = child.data {
-            self.destruction_scopes.insert(child.item_local_id(), child);
-        }
     }
 
     pub fn record_var_scope(&mut self, var: hir::ItemLocalId, lifetime: Scope) {

compiler/rustc_middle/src/mir/terminator.rs

@@ -74,6 +74,17 @@ impl SwitchTargets {
     pub fn target_for_value(&self, value: u128) -> BasicBlock {
         self.iter().find_map(|(v, t)| (v == value).then_some(t)).unwrap_or_else(|| self.otherwise())
     }
+
+    /// Adds a new target to the switch. But You cannot add an already present value.
+    #[inline]
+    pub fn add_target(&mut self, value: u128, bb: BasicBlock) {
+        let value = Pu128(value);
+        if self.values.contains(&value) {
+            bug!("target value {:?} already present", value);
+        }
+        self.values.push(value);
+        self.targets.insert(self.targets.len() - 1, bb);
+    }
 }
 
 pub struct SwitchTargetsIter<'a> {

compiler/rustc_mir_transform/src/uninhabited_enum_branching.rs

@@ -78,6 +78,7 @@ impl<'tcx> MirPass<'tcx> for UninhabitedEnumBranching {
         trace!("UninhabitedEnumBranching starting for {:?}", body.source);
 
         let mut removable_switchs = Vec::new();
+        let mut otherwise_is_last_variant_switchs = Vec::new();
 
         for (bb, bb_data) in body.basic_blocks.iter_enumerated() {
             trace!("processing block {:?}", bb);
@@ -92,8 +93,14 @@ impl<'tcx> MirPass<'tcx> for UninhabitedEnumBranching {
                 tcx.param_env_reveal_all_normalized(body.source.def_id()).and(discriminant_ty),
             );
 
-            let allowed_variants = if let Ok(layout) = layout {
+            let mut allowed_variants = if let Ok(layout) = layout {
                 variant_discriminants(&layout, discriminant_ty, tcx)
+            } else if let Some(variant_range) = discriminant_ty.variant_range(tcx) {
+                variant_range
+                    .map(|variant| {
+                        discriminant_ty.discriminant_for_variant(tcx, variant).unwrap().val
+                    })
+                    .collect()
             } else {
                 continue;
             };
@@ -103,20 +110,29 @@ impl<'tcx> MirPass<'tcx> for UninhabitedEnumBranching {
             let terminator = bb_data.terminator();
             let TerminatorKind::SwitchInt { targets, .. } = &terminator.kind else { bug!() };
 
-            let mut reachable_count = 0;
             for (index, (val, _)) in targets.iter().enumerate() {
-                if allowed_variants.contains(&val) {
-                    reachable_count += 1;
-                } else {
+                if !allowed_variants.remove(&val) {
                     removable_switchs.push((bb, index));
                 }
             }
 
-            if reachable_count == allowed_variants.len() {
+            if allowed_variants.is_empty() {
                 removable_switchs.push((bb, targets.iter().count()));
+            } else if allowed_variants.len() == 1 {
+                #[allow(rustc::potential_query_instability)]
+                let last_variant = *allowed_variants.iter().next().unwrap();
+                otherwise_is_last_variant_switchs.push((bb, last_variant));
             }
         }
 
+        for (bb, last_variant) in otherwise_is_last_variant_switchs {
+            let bb_data = &mut body.basic_blocks.as_mut()[bb];
+            let terminator = bb_data.terminator_mut();
+            let TerminatorKind::SwitchInt { targets, .. } = &mut terminator.kind else { bug!() };
+            targets.add_target(last_variant, targets.otherwise());
+            removable_switchs.push((bb, targets.iter().count()));
+        }
+
         if removable_switchs.is_empty() {
             return;
         }

compiler/rustc_parse/src/parser/diagnostics.rs

@@ -791,13 +791,28 @@ impl<'a> Parser<'a> {
                 && let [segment] = &attr_kind.item.path.segments[..]
                 && segment.ident.name == sym::cfg
                 && let Some(args_span) = attr_kind.item.args.span()
-                && let Ok(next_attr) = snapshot.parse_attribute(InnerAttrPolicy::Forbidden(None))
+                && let next_attr = match snapshot.parse_attribute(InnerAttrPolicy::Forbidden(None))
+                {
+                    Ok(next_attr) => next_attr,
+                    Err(inner_err) => {
+                        err.cancel();
+                        inner_err.cancel();
+                        return;
+                    }
+                }
                 && let ast::AttrKind::Normal(next_attr_kind) = next_attr.kind
                 && let Some(next_attr_args_span) = next_attr_kind.item.args.span()
                 && let [next_segment] = &next_attr_kind.item.path.segments[..]
                 && segment.ident.name == sym::cfg
-                && let Ok(next_expr) = snapshot.parse_expr()
             {
+                let next_expr = match snapshot.parse_expr() {
+                    Ok(next_expr) => next_expr,
+                    Err(inner_err) => {
+                        err.cancel();
+                        inner_err.cancel();
+                        return;
+                    }
+                };
                 // We have for sure
                 // #[cfg(..)]
                 // expr

compiler/rustc_session/src/config.rs

@@ -347,6 +347,7 @@ impl SwitchWithOptPath {
 pub enum SymbolManglingVersion {
     Legacy,
     V0,
+    Hashed,
 }
 
 #[derive(Clone, Copy, Debug, PartialEq, Hash)]
@@ -2692,6 +2693,7 @@ pub fn build_session_options(early_dcx: &mut EarlyDiagCtxt, matches: &getopts::M
     match cg.symbol_mangling_version {
         // Stable values:
         None | Some(SymbolManglingVersion::V0) => {}
+
         // Unstable values:
         Some(SymbolManglingVersion::Legacy) => {
             if !unstable_opts.unstable_options {
@@ -2700,6 +2702,13 @@ pub fn build_session_options(early_dcx: &mut EarlyDiagCtxt, matches: &getopts::M
                 );
             }
         }
+        Some(SymbolManglingVersion::Hashed) => {
+            if !unstable_opts.unstable_options {
+                early_dcx.early_fatal(
+                    "`-C symbol-mangling-version=hashed` requires `-Z unstable-options`",
+                );
+            }
+        }
     }
 
     // Check for unstable values of `-C instrument-coverage`.
@@ -2741,6 +2750,12 @@ pub fn build_session_options(early_dcx: &mut EarlyDiagCtxt, matches: &getopts::M
                 );
             }
             Some(SymbolManglingVersion::V0) => {}
+            Some(SymbolManglingVersion::Hashed) => {
+                early_dcx.early_warn(
+                    "-C instrument-coverage requires symbol mangling version `v0`, \
+                    but `-C symbol-mangling-version=hashed` was specified",
+                );
+            }
         }
     }
 

compiler/rustc_session/src/options.rs

@@ -407,7 +407,8 @@ mod desc {
     pub const parse_switch_with_opt_path: &str =
         "an optional path to the profiling data output directory";
     pub const parse_merge_functions: &str = "one of: `disabled`, `trampolines`, or `aliases`";
-    pub const parse_symbol_mangling_version: &str = "either `legacy` or `v0` (RFC 2603)";
+    pub const parse_symbol_mangling_version: &str =
+        "one of: `legacy`, `v0` (RFC 2603), or `hashed`";
     pub const parse_src_file_hash: &str = "either `md5` or `sha1`";
     pub const parse_relocation_model: &str =
         "one of supported relocation models (`rustc --print relocation-models`)";
@@ -1180,6 +1181,7 @@ mod parse {
         *slot = match v {
             Some("legacy") => Some(SymbolManglingVersion::Legacy),
             Some("v0") => Some(SymbolManglingVersion::V0),
+            Some("hashed") => Some(SymbolManglingVersion::Hashed),
             _ => return false,
         };
         true
@@ -1504,7 +1506,7 @@ options! {
         "tell the linker which information to strip (`none` (default), `debuginfo` or `symbols`)"),
     symbol_mangling_version: Option<SymbolManglingVersion> = (None,
         parse_symbol_mangling_version, [TRACKED],
-        "which mangling version to use for symbol names ('legacy' (default) or 'v0')"),
+        "which mangling version to use for symbol names ('legacy' (default), 'v0', or 'hashed')"),
     target_cpu: Option<String> = (None, parse_opt_string, [TRACKED],
         "select target processor (`rustc --print target-cpus` for details)"),
     target_feature: String = (String::new(), parse_target_feature, [TRACKED],

compiler/rustc_symbol_mangling/src/hashed.rs

@@ -0,0 +1,43 @@
+use crate::v0;
+use rustc_data_structures::stable_hasher::{Hash64, HashStable, StableHasher};
+use rustc_hir::def_id::CrateNum;
+use rustc_middle::ty::{Instance, TyCtxt};
+
+use std::fmt::Write;
+
+pub(super) fn mangle<'tcx>(
+    tcx: TyCtxt<'tcx>,
+    instance: Instance<'tcx>,
+    instantiating_crate: Option<CrateNum>,
+    full_mangling_name: impl FnOnce() -> String,
+) -> String {
+    // The symbol of a generic function may be scattered in multiple downstream dylibs.
+    // If the symbol of a generic function still contains `crate name`, hash conflicts between the
+    // generic funcion and other symbols of the same `crate` cannot be detected in time during
+    // construction. This symbol conflict is left over until it occurs during run time.
+    // In this case, `instantiating-crate name` is used to replace `crate name` can completely
+    // eliminate the risk of the preceding potential hash conflict.
+    let crate_num =
+        if let Some(krate) = instantiating_crate { krate } else { instance.def_id().krate };
+
+    let mut symbol = "_RNxC".to_string();
+    v0::push_ident(tcx.crate_name(crate_num).as_str(), &mut symbol);
+
+    let hash = tcx.with_stable_hashing_context(|mut hcx| {
+        let mut hasher = StableHasher::new();
+        full_mangling_name().hash_stable(&mut hcx, &mut hasher);
+        hasher.finish::<Hash64>().as_u64()
+    });
+
+    push_hash64(hash, &mut symbol);
+
+    symbol
+}
+
+// The hash is encoded based on `base-62` and the final terminator `_` is removed because it does
+// not help prevent hash collisions
+fn push_hash64(hash: u64, output: &mut String) {
+    let hash = v0::encode_integer_62(hash);
+    let hash_len = hash.len();
+    let _ = write!(output, "{hash_len}H{}", &hash[..hash_len - 1]);
+}

compiler/rustc_symbol_mangling/src/lib.rs

@@ -109,6 +109,7 @@ use rustc_middle::query::Providers;
 use rustc_middle::ty::{self, Instance, TyCtxt};
 use rustc_session::config::SymbolManglingVersion;
 
+mod hashed;
 mod legacy;
 mod v0;
 
@@ -263,6 +264,9 @@ fn compute_symbol_name<'tcx>(
     let symbol = match mangling_version {
         SymbolManglingVersion::Legacy => legacy::mangle(tcx, instance, instantiating_crate),
         SymbolManglingVersion::V0 => v0::mangle(tcx, instance, instantiating_crate),
+        SymbolManglingVersion::Hashed => hashed::mangle(tcx, instance, instantiating_crate, || {
+            v0::mangle(tcx, instance, instantiating_crate)
+        }),
     };
 
     debug_assert!(