Auto merge of #117309 - workingjubilee:rollup-zqb1dun, r=workingjubilee

Rollup of 8 pull requests

Successful merges:

 - #116534 (Remove -Zdep-tasks.)
 - #116739 (Make `E0277` use short paths)
 - #116816 (Create `windows/api.rs` for safer FFI)
 - #116945 (When encountering sealed traits, point types that implement it)
 - #117025 (Cleanup and improve `--check-cfg` implementation)
 - #117256 (Parse rustc version at compile time)
 - #117268 (`rustc_interface` cleanups)
 - #117277 (fix failure to detect a too-big-type after adding padding)

r? `@ghost`
`@rustbot` modify labels: rollup

43 files changed, 759 insertions, 445 deletions

diff --git a/Cargo.lock b/Cargo.lock
index e1b0de6c7a4..0761268c9d4 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -4054,7 +4054,6 @@ dependencies = [
  "rustc_hir_analysis",
  "rustc_hir_typeck",
  "rustc_incremental",
- "rustc_index",
  "rustc_lint",
  "rustc_macros",
  "rustc_metadata",
diff --git a/compiler/rustc_abi/src/layout.rs b/compiler/rustc_abi/src/layout.rs
index 00d862ca27b..9127e1d06e8 100644
--- a/compiler/rustc_abi/src/layout.rs
+++ b/compiler/rustc_abi/src/layout.rs
@@ -539,6 +539,7 @@ pub trait LayoutCalculator {
         // Align the maximum variant size to the largest alignment.
         size = size.align_to(align.abi);
 
+        // FIXME(oli-obk): deduplicate and harden these checks
         if size.bytes() >= dl.obj_size_bound() {
             return None;
         }
@@ -1103,6 +1104,10 @@ fn univariant<
         inverse_memory_index.into_iter().map(|it| it.index() as u32).collect()
     };
     let size = min_size.align_to(align.abi);
+    // FIXME(oli-obk): deduplicate and harden these checks
+    if size.bytes() >= dl.obj_size_bound() {
+        return None;
+    }
     let mut layout_of_single_non_zst_field = None;
     let mut abi = Abi::Aggregate { sized };
     // Try to make this a Scalar/ScalarPair.
diff --git a/compiler/rustc_attr/src/builtin.rs b/compiler/rustc_attr/src/builtin.rs
index 363ba0d4a81..ff23e3da438 100644
--- a/compiler/rustc_attr/src/builtin.rs
+++ b/compiler/rustc_attr/src/builtin.rs
@@ -10,10 +10,9 @@ use rustc_session::config::ExpectedValues;
 use rustc_session::lint::builtin::UNEXPECTED_CFGS;
 use rustc_session::lint::BuiltinLintDiagnostics;
 use rustc_session::parse::{feature_err, ParseSess};
-use rustc_session::Session;
+use rustc_session::{RustcVersion, Session};
 use rustc_span::hygiene::Transparency;
 use rustc_span::{symbol::sym, symbol::Symbol, Span};
-use std::fmt::{self, Display};
 use std::num::NonZeroU32;
 
 use crate::session_diagnostics::{self, IncorrectReprFormatGenericCause};
@@ -24,8 +23,6 @@ use crate::session_diagnostics::{self, IncorrectReprFormatGenericCause};
 /// For more, see [this pull request](https://github.com/rust-lang/rust/pull/100591).
 pub const VERSION_PLACEHOLDER: &str = "CURRENT_RUSTC_VERSION";
 
-pub const CURRENT_RUSTC_VERSION: &str = env!("CFG_RELEASE");
-
 pub fn is_builtin_attr(attr: &Attribute) -> bool {
     attr.is_doc_comment() || attr.ident().is_some_and(|ident| is_builtin_attr_name(ident.name))
 }
@@ -153,7 +150,7 @@ pub enum StabilityLevel {
 #[derive(Encodable, Decodable, PartialEq, Copy, Clone, Debug, Eq, Hash)]
 #[derive(HashStable_Generic)]
 pub enum Since {
-    Version(Version),
+    Version(RustcVersion),
     /// Stabilized in the upcoming version, whatever number that is.
     Current,
     /// Failed to parse a stabilization version.
@@ -382,7 +379,7 @@ fn parse_stability(sess: &Session, attr: &Attribute) -> Option<(Symbol, Stabilit
     let since = if let Some(since) = since {
         if since.as_str() == VERSION_PLACEHOLDER {
             Since::Current
-        } else if let Some(version) = parse_version(since.as_str(), false) {
+        } else if let Some(version) = parse_version(since) {
             Since::Version(version)
         } else {
             sess.emit_err(session_diagnostics::InvalidSince { span: attr.span });
@@ -567,31 +564,20 @@ fn gate_cfg(gated_cfg: &GatedCfg, cfg_span: Span, sess: &ParseSess, features: &F
     }
 }
 
-#[derive(Encodable, Decodable, Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
-#[derive(HashStable_Generic)]
-pub struct Version {
-    pub major: u16,
-    pub minor: u16,
-    pub patch: u16,
-}
-
-fn parse_version(s: &str, allow_appendix: bool) -> Option<Version> {
-    let mut components = s.split('-');
+/// Parse a rustc version number written inside string literal in an attribute,
+/// like appears in `since = "1.0.0"`. Suffixes like "-dev" and "-nightly" are
+/// not accepted in this position, unlike when parsing CFG_RELEASE.
+fn parse_version(s: Symbol) -> Option<RustcVersion> {
+    let mut components = s.as_str().split('-');
     let d = components.next()?;
-    if !allow_appendix && components.next().is_some() {
+    if components.next().is_some() {
         return None;
     }
     let mut digits = d.splitn(3, '.');
     let major = digits.next()?.parse().ok()?;
     let minor = digits.next()?.parse().ok()?;
     let patch = digits.next().unwrap_or("0").parse().ok()?;
-    Some(Version { major, minor, patch })
-}
-
-impl Display for Version {
-    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
-        write!(formatter, "{}.{}.{}", self.major, self.minor, self.patch)
-    }
+    Some(RustcVersion { major, minor, patch })
 }
 
 /// Evaluate a cfg-like condition (with `any` and `all`), using `eval` to
@@ -623,17 +609,16 @@ pub fn eval_condition(
                     return false;
                 }
             };
-            let Some(min_version) = parse_version(min_version.as_str(), false) else {
+            let Some(min_version) = parse_version(*min_version) else {
                 sess.emit_warning(session_diagnostics::UnknownVersionLiteral { span: *span });
                 return false;
             };
-            let rustc_version = parse_version(CURRENT_RUSTC_VERSION, true).unwrap();
 
             // See https://github.com/rust-lang/rust/issues/64796#issuecomment-640851454 for details
             if sess.assume_incomplete_release {
-                rustc_version > min_version
+                RustcVersion::CURRENT > min_version
             } else {
-                rustc_version >= min_version
+                RustcVersion::CURRENT >= min_version
             }
         }
         ast::MetaItemKind::List(mis) => {
diff --git a/compiler/rustc_attr/src/lib.rs b/compiler/rustc_attr/src/lib.rs
index 53e3eaaab37..868c0412255 100644
--- a/compiler/rustc_attr/src/lib.rs
+++ b/compiler/rustc_attr/src/lib.rs
@@ -27,6 +27,6 @@ pub use StabilityLevel::*;
 
 pub use rustc_ast::attr::*;
 
-pub(crate) use rustc_ast::HashStableContext;
+pub(crate) use rustc_session::HashStableContext;
 
 fluent_messages! { "../messages.ftl" }
diff --git a/compiler/rustc_driver_impl/src/lib.rs b/compiler/rustc_driver_impl/src/lib.rs
index c6c8fd22f4e..37897b8d702 100644
--- a/compiler/rustc_driver_impl/src/lib.rs
+++ b/compiler/rustc_driver_impl/src/lib.rs
@@ -317,7 +317,7 @@ fn run_compiler(
         return Ok(());
     }
 
-    let cfg = interface::parse_cfgspecs(&early_error_handler, matches.opt_strs("cfg"));
+    let cfg = interface::parse_cfg(&early_error_handler, matches.opt_strs("cfg"));
     let check_cfg = interface::parse_check_cfg(&early_error_handler, matches.opt_strs("check-cfg"));
     let (odir, ofile) = make_output(&matches);
     let mut config = interface::Config {
diff --git a/compiler/rustc_interface/Cargo.toml b/compiler/rustc_interface/Cargo.toml
index ae008674d01..b280665057c 100644
--- a/compiler/rustc_interface/Cargo.toml
+++ b/compiler/rustc_interface/Cargo.toml
@@ -26,7 +26,6 @@ rustc_middle = { path = "../rustc_middle" }
 rustc_ast_lowering = { path = "../rustc_ast_lowering" }
 rustc_ast_passes = { path = "../rustc_ast_passes" }
 rustc_incremental = { path = "../rustc_incremental" }
-rustc_index = { path = "../rustc_index" }
 rustc_traits = { path = "../rustc_traits" }
 rustc_data_structures = { path = "../rustc_data_structures" }
 rustc_codegen_ssa = { path = "../rustc_codegen_ssa" }
diff --git a/compiler/rustc_interface/src/callbacks.rs b/compiler/rustc_interface/src/callbacks.rs
index 45b1aeb4a5c..6fa989bb96c 100644
--- a/compiler/rustc_interface/src/callbacks.rs
+++ b/compiler/rustc_interface/src/callbacks.rs
@@ -26,7 +26,7 @@ fn track_span_parent(def_id: rustc_span::def_id::LocalDefId) {
     })
 }
 
-/// This is a callback from `rustc_ast` as it cannot access the implicit state
+/// This is a callback from `rustc_errors` as it cannot access the implicit state
 /// in `rustc_middle` otherwise. It is used when diagnostic messages are
 /// emitted and stores them in the current query, if there is one.
 fn track_diagnostic(diagnostic: &mut Diagnostic, f: &mut dyn FnMut(&mut Diagnostic)) {
diff --git a/compiler/rustc_interface/src/interface.rs b/compiler/rustc_interface/src/interface.rs
index 87badcbdf15..e703fe228c3 100644
--- a/compiler/rustc_interface/src/interface.rs
+++ b/compiler/rustc_interface/src/interface.rs
@@ -15,8 +15,10 @@ use rustc_middle::{bug, ty};
 use rustc_parse::maybe_new_parser_from_source_str;
 use rustc_query_impl::QueryCtxt;
 use rustc_query_system::query::print_query_stack;
-use rustc_session::config::{self, CheckCfg, ExpectedValues, Input, OutFileName, OutputFilenames};
-use rustc_session::parse::{CrateConfig, ParseSess};
+use rustc_session::config::{
+    self, Cfg, CheckCfg, ExpectedValues, Input, OutFileName, OutputFilenames,
+};
+use rustc_session::parse::ParseSess;
 use rustc_session::CompilerIO;
 use rustc_session::Session;
 use rustc_session::{lint, EarlyErrorHandler};
@@ -61,14 +63,13 @@ impl Compiler {
     }
 }
 
-/// Converts strings provided as `--cfg [cfgspec]` into a `crate_cfg`.
-pub fn parse_cfgspecs(
-    handler: &EarlyErrorHandler,
-    cfgspecs: Vec<String>,
-) -> FxHashSet<(String, Option<String>)> {
+/// Converts strings provided as `--cfg [cfgspec]` into a `Cfg`.
+pub fn parse_cfg(handler: &EarlyErrorHandler, cfgs: Vec<String>) -> Cfg<String> {
+    // This creates a short-lived `SessionGlobals`, containing an interner. The
+    // parsed values are converted from symbols to strings before exiting
+    // because the symbols are meaningless once the interner is gone.
     rustc_span::create_default_session_if_not_set_then(move |_| {
-        let cfg = cfgspecs
-            .into_iter()
+        cfgs.into_iter()
             .map(|s| {
                 let sess = ParseSess::with_silent_emitter(Some(format!(
                     "this error occurred on the command line: `--cfg={s}`"
@@ -97,7 +98,10 @@ pub fn parse_cfgspecs(
                                 }
                                 MetaItemKind::NameValue(..) | MetaItemKind::Word => {
                                     let ident = meta_item.ident().expect("multi-segment cfg key");
-                                    return (ident.name, meta_item.value_str());
+                                    return (
+                                        ident.name.to_string(),
+                                        meta_item.value_str().map(|sym| sym.to_string()),
+                                    );
                                 }
                             }
                         }
@@ -118,13 +122,14 @@ pub fn parse_cfgspecs(
                     error!(r#"expected `key` or `key="value"`"#);
                 }
             })
-            .collect::<CrateConfig>();
-        cfg.into_iter().map(|(a, b)| (a.to_string(), b.map(|b| b.to_string()))).collect()
+            .collect::<Cfg<String>>()
     })
 }
 
 /// Converts strings provided as `--check-cfg [specs]` into a `CheckCfg`.
-pub fn parse_check_cfg(handler: &EarlyErrorHandler, specs: Vec<String>) -> CheckCfg {
+pub fn parse_check_cfg(handler: &EarlyErrorHandler, specs: Vec<String>) -> CheckCfg<String> {
+    // The comment about `SessionGlobals` and symbols in `parse_cfg` above
+    // applies here too.
     rustc_span::create_default_session_if_not_set_then(move |_| {
         // If any --check-cfg is passed then exhaustive_values and exhaustive_names
         // are enabled by default.
@@ -140,7 +145,7 @@ pub fn parse_check_cfg(handler: &EarlyErrorHandler, specs: Vec<String>) -> Check
             let filename = FileName::cfg_spec_source_code(&s);
 
             macro_rules! error {
-                ($reason: expr) => {
+                ($reason:expr) => {
                     handler.early_error(format!(
                         concat!("invalid `--check-cfg` argument: `{}` (", $reason, ")"),
                         s
@@ -148,217 +153,202 @@ pub fn parse_check_cfg(handler: &EarlyErrorHandler, specs: Vec<String>) -> Check
                 };
             }
 
-            let expected_error =
-                || error!("expected `cfg(name, values(\"value1\", \"value2\", ... \"valueN\"))`");
-
-            match maybe_new_parser_from_source_str(&sess, filename, s.to_string()) {
-                Ok(mut parser) => match parser.parse_meta_item() {
-                    Ok(meta_item) if parser.token == token::Eof => {
-                        if let Some(args) = meta_item.meta_item_list() {
-                            if meta_item.has_name(sym::names) {
-                                // defaults are flipped for the old syntax
-                                if old_syntax == None {
-                                    check_cfg.exhaustive_names = false;
-                                    check_cfg.exhaustive_values = false;
-                                }
-                                old_syntax = Some(true);
-
-                                check_cfg.exhaustive_names = true;
-                                for arg in args {
-                                    if arg.is_word() && arg.ident().is_some() {
-                                        let ident = arg.ident().expect("multi-segment cfg key");
-                                        check_cfg
-                                            .expecteds
-                                            .entry(ident.name.to_string())
-                                            .or_insert(ExpectedValues::Any);
-                                    } else {
-                                        error!("`names()` arguments must be simple identifiers");
-                                    }
-                                }
-                            } else if meta_item.has_name(sym::values) {
-                                // defaults are flipped for the old syntax
-                                if old_syntax == None {
-                                    check_cfg.exhaustive_names = false;
-                                    check_cfg.exhaustive_values = false;
-                                }
-                                old_syntax = Some(true);
-
-                                if let Some((name, values)) = args.split_first() {
-                                    if name.is_word() && name.ident().is_some() {
-                                        let ident = name.ident().expect("multi-segment cfg key");
-                                        let expected_values = check_cfg
-                                            .expecteds
-                                            .entry(ident.name.to_string())
-                                            .and_modify(|expected_values| match expected_values {
-                                                ExpectedValues::Some(_) => {}
-                                                ExpectedValues::Any => {
-                                                    // handle the case where names(...) was done
-                                                    // before values by changing to a list
-                                                    *expected_values =
-                                                        ExpectedValues::Some(FxHashSet::default());
-                                                }
-                                            })
-                                            .or_insert_with(|| {
-                                                ExpectedValues::Some(FxHashSet::default())
-                                            });
-
-                                        let ExpectedValues::Some(expected_values) = expected_values
-                                        else {
-                                            bug!("`expected_values` should be a list a values")
-                                        };
-
-                                        for val in values {
-                                            if let Some(LitKind::Str(s, _)) =
-                                                val.lit().map(|lit| &lit.kind)
-                                            {
-                                                expected_values.insert(Some(s.to_string()));
-                                            } else {
-                                                error!(
-                                                    "`values()` arguments must be string literals"
-                                                );
-                                            }
-                                        }
-
-                                        if values.is_empty() {
-                                            expected_values.insert(None);
-                                        }
-                                    } else {
-                                        error!(
-                                            "`values()` first argument must be a simple identifier"
-                                        );
-                                    }
-                                } else if args.is_empty() {
-                                    check_cfg.exhaustive_values = true;
-                                } else {
-                                    expected_error();
-                                }
-                            } else if meta_item.has_name(sym::cfg) {
-                                old_syntax = Some(false);
-
-                                let mut names = Vec::new();
-                                let mut values: FxHashSet<_> = Default::default();
-
-                                let mut any_specified = false;
-                                let mut values_specified = false;
-                                let mut values_any_specified = false;
-
-                                for arg in args {
-                                    if arg.is_word() && let Some(ident) = arg.ident() {
-                                        if values_specified {
-                                            error!("`cfg()` names cannot be after values");
-                                        }
-                                        names.push(ident);
-                                    } else if arg.has_name(sym::any)
-                                        && let Some(args) = arg.meta_item_list()
-                                    {
-                                        if any_specified {
-                                            error!("`any()` cannot be specified multiple times");
-                                        }
-                                        any_specified = true;
-                                        if !args.is_empty() {
-                                            error!("`any()` must be empty");
-                                        }
-                                    } else if arg.has_name(sym::values)
-                                        && let Some(args) = arg.meta_item_list()
-                                    {
-                                        if names.is_empty() {
-                                            error!(
-                                                "`values()` cannot be specified before the names"
-                                            );
-                                        } else if values_specified {
-                                            error!(
-                                                "`values()` cannot be specified multiple times"
-                                            );
-                                        }
-                                        values_specified = true;
-
-                                        for arg in args {
-                                            if let Some(LitKind::Str(s, _)) =
-                                                arg.lit().map(|lit| &lit.kind)
-                                            {
-                                                values.insert(Some(s.to_string()));
-                                            } else if arg.has_name(sym::any)
-                                                && let Some(args) = arg.meta_item_list()
-                                            {
-                                                if values_any_specified {
-                                                    error!(
-                                                        "`any()` in `values()` cannot be specified multiple times"
-                                                    );
-                                                }
-                                                values_any_specified = true;
-                                                if !args.is_empty() {
-                                                    error!("`any()` must be empty");
-                                                }
-                                            } else {
-                                                error!(
-                                                    "`values()` arguments must be string literals or `any()`"
-                                                );
-                                            }
-                                        }
-                                    } else {
-                                        error!(
-                                            "`cfg()` arguments must be simple identifiers, `any()` or `values(...)`"
-                                        );
-                                    }
+            let expected_error = || -> ! {
+                error!("expected `cfg(name, values(\"value1\", \"value2\", ... \"valueN\"))`")
+            };
+
+            let Ok(mut parser) = maybe_new_parser_from_source_str(&sess, filename, s.to_string())
+            else {
+                expected_error();
+            };
+
+            let meta_item = match parser.parse_meta_item() {
+                Ok(meta_item) if parser.token == token::Eof => meta_item,
+                Ok(..) => expected_error(),
+                Err(err) => {
+                    err.cancel();
+                    expected_error();
+                }
+            };
+
+            let Some(args) = meta_item.meta_item_list() else {
+                expected_error();
+            };
+
+            if meta_item.has_name(sym::names) {
+                // defaults are flipped for the old syntax
+                if old_syntax == None {
+                    check_cfg.exhaustive_names = false;
+                    check_cfg.exhaustive_values = false;
+                }
+                old_syntax = Some(true);
+
+                check_cfg.exhaustive_names = true;
+                for arg in args {
+                    if arg.is_word() && arg.ident().is_some() {
+                        let ident = arg.ident().expect("multi-segment cfg key");
+                        check_cfg
+                            .expecteds
+                            .entry(ident.name.to_string())
+                            .or_insert(ExpectedValues::Any);
+                    } else {
+                        error!("`names()` arguments must be simple identifiers");
+                    }
+                }
+            } else if meta_item.has_name(sym::values) {
+                // defaults are flipped for the old syntax
+                if old_syntax == None {
+                    check_cfg.exhaustive_names = false;
+                    check_cfg.exhaustive_values = false;
+                }
+                old_syntax = Some(true);
+
+                if let Some((name, values)) = args.split_first() {
+                    if name.is_word() && name.ident().is_some() {
+                        let ident = name.ident().expect("multi-segment cfg key");
+                        let expected_values = check_cfg
+                            .expecteds
+                            .entry(ident.name.to_string())
+                            .and_modify(|expected_values| match expected_values {
+                                ExpectedValues::Some(_) => {}
+                                ExpectedValues::Any => {
+                                    // handle the case where names(...) was done
+                                    // before values by changing to a list
+                                    *expected_values = ExpectedValues::Some(FxHashSet::default());
                                 }
+                            })
+                            .or_insert_with(|| ExpectedValues::Some(FxHashSet::default()));
 
-                                if values.is_empty() && !values_any_specified && !any_specified {
-                                    values.insert(None);
-                                } else if !values.is_empty() && values_any_specified {
+                        let ExpectedValues::Some(expected_values) = expected_values else {
+                            bug!("`expected_values` should be a list a values")
+                        };
+
+                        for val in values {
+                            if let Some(LitKind::Str(s, _)) = val.lit().map(|lit| &lit.kind) {
+                                expected_values.insert(Some(s.to_string()));
+                            } else {
+                                error!("`values()` arguments must be string literals");
+                            }
+                        }
+
+                        if values.is_empty() {
+                            expected_values.insert(None);
+                        }
+                    } else {
+                        error!("`values()` first argument must be a simple identifier");
+                    }
+                } else if args.is_empty() {
+                    check_cfg.exhaustive_values = true;
+                } else {
+                    expected_error();
+                }
+            } else if meta_item.has_name(sym::cfg) {
+                old_syntax = Some(false);
+
+                let mut names = Vec::new();
+                let mut values: FxHashSet<_> = Default::default();
+
+                let mut any_specified = false;
+                let mut values_specified = false;
+                let mut values_any_specified = false;
+
+                for arg in args {
+                    if arg.is_word() && let Some(ident) = arg.ident() {
+                        if values_specified {
+                            error!("`cfg()` names cannot be after values");
+                        }
+                        names.push(ident);
+                    } else if arg.has_name(sym::any)
+                        && let Some(args) = arg.meta_item_list()
+                    {
+                        if any_specified {
+                            error!("`any()` cannot be specified multiple times");
+                        }
+                        any_specified = true;
+                        if !args.is_empty() {
+                            error!("`any()` must be empty");
+                        }
+                    } else if arg.has_name(sym::values)
+                        && let Some(args) = arg.meta_item_list()
+                    {
+                        if names.is_empty() {
+                            error!("`values()` cannot be specified before the names");
+                        } else if values_specified {
+                            error!("`values()` cannot be specified multiple times");
+                        }
+                        values_specified = true;
+
+                        for arg in args {
+                            if let Some(LitKind::Str(s, _)) =
+                                arg.lit().map(|lit| &lit.kind)
+                            {
+                                values.insert(Some(s.to_string()));
+                            } else if arg.has_name(sym::any)
+                                && let Some(args) = arg.meta_item_list()
+                            {
+                                if values_any_specified {
                                     error!(
-                                        "`values()` arguments cannot specify string literals and `any()` at the same time"
+                                        "`any()` in `values()` cannot be specified multiple times"
                                     );
                                 }
-
-                                if any_specified {
-                                    if !names.is_empty()
-                                        || !values.is_empty()
-                                        || values_any_specified
-                                    {
-                                        error!("`cfg(any())` can only be provided in isolation");
-                                    }
-
-                                    check_cfg.exhaustive_names = false;
-                                } else {
-                                    for name in names {
-                                        check_cfg
-                                            .expecteds
-                                            .entry(name.to_string())
-                                            .and_modify(|v| match v {
-                                                ExpectedValues::Some(v)
-                                                    if !values_any_specified =>
-                                                {
-                                                    v.extend(values.clone())
-                                                }
-                                                ExpectedValues::Some(_) => *v = ExpectedValues::Any,
-                                                ExpectedValues::Any => {}
-                                            })
-                                            .or_insert_with(|| {
-                                                if values_any_specified {
-                                                    ExpectedValues::Any
-                                                } else {
-                                                    ExpectedValues::Some(values.clone())
-                                                }
-                                            });
-                                    }
+                                values_any_specified = true;
+                                if !args.is_empty() {
+                                    error!("`any()` must be empty");
                                 }
                             } else {
-                                expected_error();
+                                error!(
+                                    "`values()` arguments must be string literals or `any()`"
+                                );
                             }
-                        } else {
-                            expected_error();
                         }
+                    } else {
+                        error!(
+                            "`cfg()` arguments must be simple identifiers, `any()` or `values(...)`"
+                        );
                     }
-                    Ok(..) => expected_error(),
-                    Err(err) => {
-                        err.cancel();
-                        expected_error();
+                }
+
+                if values.is_empty() && !values_any_specified && !any_specified {
+                    values.insert(None);
+                } else if !values.is_empty() && values_any_specified {
+                    error!(
+                        "`values()` arguments cannot specify string literals and `any()` at the same time"
+                    );
+                }
+
+                if any_specified {
+                    if names.is_empty()
+                        && values.is_empty()
+                        && !values_specified
+                        && !values_any_specified
+                    {
+                        check_cfg.exhaustive_names = false;
+                    } else {
+                        error!("`cfg(any())` can only be provided in isolation");
+                    }
+                } else {
+                    for name in names {
+                        check_cfg
+                            .expecteds
+                            .entry(name.to_string())
+                            .and_modify(|v| match v {
+                                ExpectedValues::Some(v) if !values_any_specified => {
+                                    v.extend(values.clone())
+                                }
+                                ExpectedValues::Some(_) => *v = ExpectedValues::Any,
+                                ExpectedValues::Any => {}
+                            })
+                            .or_insert_with(|| {
+                                if values_any_specified {
+                                    ExpectedValues::Any
+                                } else {
+                                    ExpectedValues::Some(values.clone())
+                                }
+                            });
                     }
-                },
-                Err(errs) => {
-                    drop(errs);
-                    expected_error();
                 }
+            } else {
+                expected_error();
             }
         }
 
@@ -372,8 +362,8 @@ pub struct Config {
     pub opts: config::Options,
 
     /// cfg! configuration in addition to the default ones
-    pub crate_cfg: FxHashSet<(String, Option<String>)>,
-    pub crate_check_cfg: CheckCfg,
+    pub crate_cfg: Cfg<String>,
+    pub crate_check_cfg: CheckCfg<String>,
 
     pub input: Input,
     pub output_dir: Option<PathBuf>,
diff --git a/compiler/rustc_interface/src/tests.rs b/compiler/rustc_interface/src/tests.rs
index 3d191669b1a..57ca709267a 100644
--- a/compiler/rustc_interface/src/tests.rs
+++ b/compiler/rustc_interface/src/tests.rs
@@ -1,17 +1,16 @@
 #![allow(rustc::bad_opt_access)]
-use crate::interface::parse_cfgspecs;
-
-use rustc_data_structures::fx::FxHashSet;
+use crate::interface::parse_cfg;
 use rustc_data_structures::profiling::TimePassesFormat;
 use rustc_errors::{emitter::HumanReadableErrorType, registry, ColorConfig};
 use rustc_session::config::rustc_optgroups;
+use rustc_session::config::Cfg;
 use rustc_session::config::DebugInfo;
 use rustc_session::config::Input;
 use rustc_session::config::InstrumentXRay;
 use rustc_session::config::LinkSelfContained;
 use rustc_session::config::Polonius;
 use rustc_session::config::TraitSolver;
-use rustc_session::config::{build_configuration, build_session_options, to_crate_config};
+use rustc_session::config::{build_configuration, build_session_options};
 use rustc_session::config::{
     BranchProtection, Externs, OomStrategy, OutFileName, OutputType, OutputTypes, PAuthKey, PacRet,
     ProcMacroExecutionStrategy, SymbolManglingVersion, WasiExecModel,
@@ -31,26 +30,18 @@ use rustc_span::FileName;
 use rustc_span::SourceFileHashAlgorithm;
 use rustc_target::spec::{CodeModel, LinkerFlavorCli, MergeFunctions, PanicStrategy, RelocModel};
 use rustc_target::spec::{RelroLevel, SanitizerSet, SplitDebuginfo, StackProtector, TlsModel};
-
 use std::collections::{BTreeMap, BTreeSet};
 use std::num::NonZeroUsize;
 use std::path::{Path, PathBuf};
 use std::sync::Arc;
 
-type CfgSpecs = FxHashSet<(String, Option<String>)>;
-
-fn build_session_options_and_crate_config(
+fn mk_session(
     handler: &mut EarlyErrorHandler,
     matches: getopts::Matches,
-) -> (Options, CfgSpecs) {
-    let sessopts = build_session_options(handler, &matches);
-    let cfg = parse_cfgspecs(handler, matches.opt_strs("cfg"));
-    (sessopts, cfg)
-}
-
-fn mk_session(handler: &mut EarlyErrorHandler, matches: getopts::Matches) -> (Session, CfgSpecs) {
+) -> (Session, Cfg<String>) {
     let registry = registry::Registry::new(&[]);
-    let (sessopts, cfg) = build_session_options_and_crate_config(handler, matches);
+    let sessopts = build_session_options(handler, &matches);
+    let cfg = parse_cfg(handler, matches.opt_strs("cfg"));
     let temps_dir = sessopts.unstable_opts.temps_dir.as_deref().map(PathBuf::from);
     let io = CompilerIO {
         input: Input::Str { name: FileName::Custom(String::new()), input: String::new() },
@@ -141,7 +132,7 @@ fn test_switch_implies_cfg_test() {
         let matches = optgroups().parse(&["--test".to_string()]).unwrap();
         let mut handler = EarlyErrorHandler::new(ErrorOutputType::default());
         let (sess, cfg) = mk_session(&mut handler, matches);
-        let cfg = build_configuration(&sess, to_crate_config(cfg));
+        let cfg = build_configuration(&sess, cfg);
         assert!(cfg.contains(&(sym::test, None)));
     });
 }
@@ -153,7 +144,7 @@ fn test_switch_implies_cfg_test_unless_cfg_test() {
         let matches = optgroups().parse(&["--test".to_string(), "--cfg=test".to_string()]).unwrap();
         let mut handler = EarlyErrorHandler::new(ErrorOutputType::default());
         let (sess, cfg) = mk_session(&mut handler, matches);
-        let cfg = build_configuration(&sess, to_crate_config(cfg));
+        let cfg = build_configuration(&sess, cfg);
         let mut test_items = cfg.iter().filter(|&&(name, _)| name == sym::test);
         assert!(test_items.next().is_some());
         assert!(test_items.next().is_none());
@@ -684,7 +675,6 @@ fn test_unstable_options_tracking_hash() {
     // tidy-alphabetical-start
     untracked!(assert_incr_state, Some(String::from("loaded")));
     untracked!(deduplicate_diagnostics, false);
-    untracked!(dep_tasks, true);
     untracked!(dont_buffer_diagnostics, true);
     untracked!(dump_dep_graph, true);
     untracked!(dump_mir, Some(String::from("abc")));
@@ -880,6 +870,6 @@ fn test_edition_parsing() {
     let mut handler = EarlyErrorHandler::new(ErrorOutputType::default());
 
     let matches = optgroups().parse(&["--edition=2018".to_string()]).unwrap();
-    let (sessopts, _) = build_session_options_and_crate_config(&mut handler, matches);
+    let sessopts = build_session_options(&mut handler, &matches);
     assert!(sessopts.edition == Edition::Edition2018)
 }
diff --git a/compiler/rustc_interface/src/util.rs b/compiler/rustc_interface/src/util.rs
index d2455a036cc..4d0be65697a 100644
--- a/compiler/rustc_interface/src/util.rs
+++ b/compiler/rustc_interface/src/util.rs
@@ -3,18 +3,17 @@ use info;
 use libloading::Library;
 use rustc_ast as ast;
 use rustc_codegen_ssa::traits::CodegenBackend;
-use rustc_data_structures::fx::{FxHashMap, FxHashSet};
+use rustc_data_structures::fx::FxHashMap;
 #[cfg(parallel_compiler)]
 use rustc_data_structures::sync;
 use rustc_errors::registry::Registry;
 use rustc_parse::validate_attr;
 use rustc_session as session;
-use rustc_session::config::CheckCfg;
-use rustc_session::config::{self, CrateType};
-use rustc_session::config::{OutFileName, OutputFilenames, OutputTypes};
+use rustc_session::config::{
+    self, Cfg, CheckCfg, CrateType, OutFileName, OutputFilenames, OutputTypes,
+};
 use rustc_session::filesearch::sysroot_candidates;
 use rustc_session::lint::{self, BuiltinLintDiagnostics, LintBuffer};
-use rustc_session::parse::CrateConfig;
 use rustc_session::{filesearch, output, Session};
 use rustc_span::edit_distance::find_best_match_for_name;
 use rustc_span::edition::Edition;
@@ -38,7 +37,7 @@ pub type MakeBackendFn = fn() -> Box<dyn CodegenBackend>;
 /// This is performed by checking whether a set of permitted features
 /// is available on the target machine, by querying the codegen backend.
 pub fn add_configuration(
-    cfg: &mut CrateConfig,
+    cfg: &mut Cfg<Symbol>,
     sess: &mut Session,
     codegen_backend: &dyn CodegenBackend,
 ) {
@@ -60,8 +59,8 @@ pub fn add_configuration(
 pub fn create_session(
     handler: &EarlyErrorHandler,
     sopts: config::Options,
-    cfg: FxHashSet<(String, Option<String>)>,
-    check_cfg: CheckCfg,
+    cfg: Cfg<String>,
+    check_cfg: CheckCfg<String>,
     locale_resources: &'static [&'static str],
     file_loader: Option<Box<dyn FileLoader + Send + Sync + 'static>>,
     io: CompilerIO,
@@ -121,12 +120,13 @@ pub fn create_session(
 
     codegen_backend.init(&sess);
 
-    let mut cfg = config::build_configuration(&sess, config::to_crate_config(cfg));
+    let mut cfg = config::build_configuration(&sess, cfg);
     add_configuration(&mut cfg, &mut sess, &*codegen_backend);
 
-    let mut check_cfg = config::to_crate_check_config(check_cfg);
+    let mut check_cfg = check_cfg.intern();
     check_cfg.fill_well_known(&sess.target);
 
+    // These configs use symbols, rather than strings.
     sess.parse_sess.config = cfg;
     sess.parse_sess.check_config = check_cfg;
 
diff --git a/compiler/rustc_macros/src/current_version.rs b/compiler/rustc_macros/src/current_version.rs
new file mode 100644
index 00000000000..5e3b91c17bf
--- /dev/null
+++ b/compiler/rustc_macros/src/current_version.rs
@@ -0,0 +1,59 @@
+use proc_macro::TokenStream;
+use proc_macro2::Span;
+use quote::quote;
+use syn::parse::{Parse, ParseStream};
+use syn::{parenthesized, parse_macro_input, LitStr, Token};
+
+pub struct Input {
+    variable: LitStr,
+}
+
+mod kw {
+    syn::custom_keyword!(env);
+}
+
+impl Parse for Input {
+    // Input syntax is `env!("CFG_RELEASE")` to facilitate grepping.
+    fn parse(input: ParseStream<'_>) -> syn::Result<Self> {
+        let paren;
+        input.parse::<kw::env>()?;
+        input.parse::<Token![!]>()?;
+        parenthesized!(paren in input);
+        let variable: LitStr = paren.parse()?;
+        Ok(Input { variable })
+    }
+}
+
+pub(crate) fn current_version(input: TokenStream) -> TokenStream {
+    let input = parse_macro_input!(input as Input);
+
+    TokenStream::from(match RustcVersion::parse_env_var(&input.variable) {
+        Ok(RustcVersion { major, minor, patch }) => quote!(
+            Self { major: #major, minor: #minor, patch: #patch }
+        ),
+        Err(err) => syn::Error::new(Span::call_site(), err).into_compile_error(),
+    })
+}
+
+struct RustcVersion {
+    major: u16,
+    minor: u16,
+    patch: u16,
+}
+
+impl RustcVersion {
+    fn parse_env_var(env_var: &LitStr) -> Result<Self, Box<dyn std::error::Error>> {
+        let value = proc_macro::tracked_env::var(env_var.value())?;
+        Self::parse_str(&value)
+            .ok_or_else(|| format!("failed to parse rustc version: {:?}", value).into())
+    }
+
+    fn parse_str(value: &str) -> Option<Self> {
+        // Ignore any suffixes such as "-dev" or "-nightly".
+        let mut components = value.split('-').next().unwrap().splitn(3, '.');
+        let major = components.next()?.parse().ok()?;
+        let minor = components.next()?.parse().ok()?;
+        let patch = components.next().unwrap_or("0").parse().ok()?;
+        Some(RustcVersion { major, minor, patch })
+    }
+}
diff --git a/compiler/rustc_macros/src/lib.rs b/compiler/rustc_macros/src/lib.rs
index 776ba8f9ca1..193dbd75fbd 100644
--- a/compiler/rustc_macros/src/lib.rs
+++ b/compiler/rustc_macros/src/lib.rs
@@ -15,6 +15,7 @@ use synstructure::decl_derive;
 
 use proc_macro::TokenStream;
 
+mod current_version;
 mod diagnostics;
 mod hash_stable;
 mod lift;
@@ -26,6 +27,11 @@ mod type_foldable;
 mod type_visitable;
 
 #[proc_macro]
+pub fn current_rustc_version(input: TokenStream) -> TokenStream {
+    current_version::current_version(input)
+}
+
+#[proc_macro]
 pub fn rustc_queries(input: TokenStream) -> TokenStream {
     query::rustc_queries(input)
 }
diff --git a/compiler/rustc_middle/src/middle/stability.rs b/compiler/rustc_middle/src/middle/stability.rs
index 84893b8e627..20547696d5a 100644
--- a/compiler/rustc_middle/src/middle/stability.rs
+++ b/compiler/rustc_middle/src/middle/stability.rs
@@ -16,7 +16,7 @@ use rustc_middle::ty::print::with_no_trimmed_paths;
 use rustc_session::lint::builtin::{DEPRECATED, DEPRECATED_IN_FUTURE, SOFT_UNSTABLE};
 use rustc_session::lint::{BuiltinLintDiagnostics, Level, Lint, LintBuffer};
 use rustc_session::parse::feature_err_issue;
-use rustc_session::Session;
+use rustc_session::{RustcVersion, Session};
 use rustc_span::symbol::{sym, Symbol};
 use rustc_span::Span;
 use std::num::NonZeroU32;
@@ -129,11 +129,6 @@ pub fn deprecation_in_effect(depr: &Deprecation) -> bool {
     let is_since_rustc_version = depr.is_since_rustc_version;
     let since = depr.since.as_ref().map(Symbol::as_str);
 
-    fn parse_version(ver: &str) -> Vec<u32> {
-        // We ignore non-integer components of the version (e.g., "nightly").
-        ver.split(|c| c == '.' || c == '-').flat_map(|s| s.parse()).collect()
-    }
-
     if !is_since_rustc_version {
         // The `since` field doesn't have semantic purpose without `#![staged_api]`.
         return true;
@@ -144,16 +139,18 @@ pub fn deprecation_in_effect(depr: &Deprecation) -> bool {
             return false;
         }
 
-        if let Some(rustc) = option_env!("CFG_RELEASE") {
-            let since: Vec<u32> = parse_version(&since);
-            let rustc: Vec<u32> = parse_version(rustc);
-            // We simply treat invalid `since` attributes as relating to a previous
-            // Rust version, thus always displaying the warning.
-            if since.len() != 3 {
-                return true;
-            }
-            return since <= rustc;
+        // We ignore non-integer components of the version (e.g., "nightly").
+        let since: Vec<u16> =
+            since.split(|c| c == '.' || c == '-').flat_map(|s| s.parse()).collect();
+
+        // We simply treat invalid `since` attributes as relating to a previous
+        // Rust version, thus always displaying the warning.
+        if since.len() != 3 {
+            return true;
         }
+
+        let rustc = RustcVersion::CURRENT;
+        return since.as_slice() <= &[rustc.major, rustc.minor, rustc.patch];
     };
 
     // Assume deprecation is in effect if "since" field is missing
diff --git a/compiler/rustc_query_impl/src/plumbing.rs b/compiler/rustc_query_impl/src/plumbing.rs
index 536c0a20e2a..6ad72e37a8c 100644
--- a/compiler/rustc_query_impl/src/plumbing.rs
+++ b/compiler/rustc_query_impl/src/plumbing.rs
@@ -440,8 +440,6 @@ where
     );
 
     if let Some(key) = Q::Key::recover(tcx, &dep_node) {
-        #[cfg(debug_assertions)]
-        let _guard = tracing::span!(tracing::Level::TRACE, stringify!($name), ?key).entered();
         force_query(query, QueryCtxt::new(tcx), key, dep_node);
         true
     } else {
diff --git a/compiler/rustc_query_system/src/dep_graph/graph.rs b/compiler/rustc_query_system/src/dep_graph/graph.rs
index 5ce21e0bbc6..6cace01955e 100644
--- a/compiler/rustc_query_system/src/dep_graph/graph.rs
+++ b/compiler/rustc_query_system/src/dep_graph/graph.rs
@@ -149,7 +149,6 @@ impl<D: Deps> DepGraph<D> {
             DepNode { kind: D::DEP_KIND_RED, hash: Fingerprint::ZERO.into() },
             EdgesVec::new(),
             None,
-            false,
         );
         assert_eq!(red_node_index, DepNodeIndex::FOREVER_RED_NODE);
         match red_node_prev_index_and_color {
@@ -373,8 +372,6 @@ impl<D: Deps> DepGraphData<D> {
         let current_fingerprint =
             hash_result.map(|f| dcx.with_stable_hashing_context(|mut hcx| f(&mut hcx, &result)));
 
-        let print_status = cfg!(debug_assertions) && dcx.sess().opts.unstable_opts.dep_tasks;
-
         // Intern the new `DepNode`.
         let (dep_node_index, prev_and_color) = self.current.intern_node(
             dcx.profiler(),
@@ -382,7 +379,6 @@ impl<D: Deps> DepGraphData<D> {
             key,
             edges,
             current_fingerprint,
-            print_status,
         );
 
         hashing_timer.finish_with_query_invocation_id(dep_node_index.into());
@@ -589,8 +585,6 @@ impl<D: Deps> DepGraph<D> {
                 cx.with_stable_hashing_context(|mut hcx| hash_result(&mut hcx, result))
             });
 
-            let print_status = cfg!(debug_assertions) && cx.sess().opts.unstable_opts.dep_tasks;
-
             // Intern the new `DepNode` with the dependencies up-to-now.
             let (dep_node_index, prev_and_color) = data.current.intern_node(
                 cx.profiler(),
@@ -598,7 +592,6 @@ impl<D: Deps> DepGraph<D> {
                 node,
                 edges,
                 current_fingerprint,
-                print_status,
             );
 
             hashing_timer.finish_with_query_invocation_id(dep_node_index.into());
@@ -1219,20 +1212,13 @@ impl<D: Deps> CurrentDepGraph<D> {
         key: DepNode,
         edges: EdgesVec,
         fingerprint: Option<Fingerprint>,
-        print_status: bool,
     ) -> (DepNodeIndex, Option<(SerializedDepNodeIndex, DepNodeColor)>) {
-        let print_status = cfg!(debug_assertions) && print_status;
-
         // Get timer for profiling `DepNode` interning
         let _node_intern_timer =
             self.node_intern_event_id.map(|eid| profiler.generic_activity_with_event_id(eid));
 
         if let Some(prev_index) = prev_graph.node_to_index_opt(&key) {
-            let get_dep_node_index = |color, fingerprint| {
-                if print_status {
-                    eprintln!("[task::{color:}] {key:?}");
-                }
-
+            let get_dep_node_index = |fingerprint| {
                 let mut prev_index_to_index = self.prev_index_to_index.lock();
 
                 let dep_node_index = match prev_index_to_index[prev_index] {
@@ -1256,12 +1242,12 @@ impl<D: Deps> CurrentDepGraph<D> {
                 if fingerprint == prev_graph.fingerprint_by_index(prev_index) {
                     // This is a green node: it existed in the previous compilation,
                     // its query was re-executed, and it has the same result as before.
-                    let dep_node_index = get_dep_node_index("green", fingerprint);
+                    let dep_node_index = get_dep_node_index(fingerprint);
                     (dep_node_index, Some((prev_index, DepNodeColor::Green(dep_node_index))))
                 } else {
                     // This is a red node: it existed in the previous compilation, its query
                     // was re-executed, but it has a different result from before.
-                    let dep_node_index = get_dep_node_index("red", fingerprint);
+                    let dep_node_index = get_dep_node_index(fingerprint);
                     (dep_node_index, Some((prev_index, DepNodeColor::Red)))
                 }
             } else {
@@ -1269,14 +1255,10 @@ impl<D: Deps> CurrentDepGraph<D> {
                 // session, its query was re-executed, but it doesn't compute a result hash
                 // (i.e. it represents a `no_hash` query), so we have no way of determining
                 // whether or not the result was the same as before.
-                let dep_node_index = get_dep_node_index("unknown", Fingerprint::ZERO);
+                let dep_node_index = get_dep_node_index(Fingerprint::ZERO);
                 (dep_node_index, Some((prev_index, DepNodeColor::Red)))
             }
         } else {
-            if print_status {
-                eprintln!("[task::new] {key:?}");
-            }
-
             let fingerprint = fingerprint.unwrap_or(Fingerprint::ZERO);
 
             // This is a new node: it didn't exist in the previous compilation session.
diff --git a/compiler/rustc_session/src/config.rs b/compiler/rustc_session/src/config.rs
index 7aced414ed6..854e2b77993 100644
--- a/compiler/rustc_session/src/config.rs
+++ b/compiler/rustc_session/src/config.rs
@@ -9,14 +9,13 @@ use crate::utils::{CanonicalizedPath, NativeLib, NativeLibKind};
 use crate::{lint, HashStableContext};
 use crate::{EarlyErrorHandler, Session};
 
-use rustc_data_structures::fx::{FxHashMap, FxHashSet};
+use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexSet};
 use rustc_data_structures::stable_hasher::{StableOrd, ToStableHashKey};
 use rustc_target::abi::Align;
 use rustc_target::spec::LinkSelfContainedComponents;
 use rustc_target::spec::{PanicStrategy, RelocModel, SanitizerSet, SplitDebuginfo};
 use rustc_target::spec::{Target, TargetTriple, TargetWarnings, TARGETS};
 
-use crate::parse::{CrateCheckConfig, CrateConfig};
 use rustc_feature::UnstableFeatures;
 use rustc_span::edition::{Edition, DEFAULT_EDITION, EDITION_NAME_LIST, LATEST_STABLE_EDITION};
 use rustc_span::source_map::{FileName, FilePathMapping};
@@ -1248,8 +1247,8 @@ pub const fn default_lib_output() -> CrateType {
     CrateType::Rlib
 }
 
-fn default_configuration(sess: &Session) -> CrateConfig {
-    // NOTE: This should be kept in sync with `CrateCheckConfig::fill_well_known` below.
+fn default_configuration(sess: &Session) -> Cfg<Symbol> {
+    // NOTE: This should be kept in sync with `CheckCfg::<Symbol>::fill_well_known` below.
     let end = &sess.target.endian;
     let arch = &sess.target.arch;
     let wordsz = sess.target.pointer_width.to_string();
@@ -1265,7 +1264,7 @@ fn default_configuration(sess: &Session) -> CrateConfig {
         sess.emit_fatal(err);
     });
 
-    let mut ret = CrateConfig::default();
+    let mut ret = Cfg::default();
     ret.reserve(7); // the minimum number of insertions
     // Target bindings.
     ret.insert((sym::target_os, Some(Symbol::intern(os))));
@@ -1358,15 +1357,17 @@ fn default_configuration(sess: &Session) -> CrateConfig {
     ret
 }
 
-/// Converts the crate `cfg!` configuration from `String` to `Symbol`.
-/// `rustc_interface::interface::Config` accepts this in the compiler configuration,
-/// but the symbol interner is not yet set up then, so we must convert it later.
-pub fn to_crate_config(cfg: FxHashSet<(String, Option<String>)>) -> CrateConfig {
-    cfg.into_iter().map(|(a, b)| (Symbol::intern(&a), b.map(|b| Symbol::intern(&b)))).collect()
-}
+/// The parsed `--cfg` options that define the compilation environment of the
+/// crate, used to drive conditional compilation. `T` is always `String` or
+/// `Symbol`. Strings are used temporarily very early on. Once the the main
+/// symbol interner is running, they are converted to symbols.
+///
+/// An `FxIndexSet` is used to ensure deterministic ordering of error messages
+/// relating to `--cfg`.
+pub type Cfg<T> = FxIndexSet<(T, Option<T>)>;
 
-/// The parsed `--check-cfg` options
-pub struct CheckCfg<T = String> {
+/// The parsed `--check-cfg` options. The `<T>` structure is similar to `Cfg`.
+pub struct CheckCfg<T> {
     /// Is well known names activated
     pub exhaustive_names: bool,
     /// Is well known values activated
@@ -1385,8 +1386,8 @@ impl<T> Default for CheckCfg<T> {
     }
 }
 
-impl<T> CheckCfg<T> {
-    fn map_data<O: Eq + Hash>(self, f: impl Fn(T) -> O) -> CheckCfg<O> {
+impl CheckCfg<String> {
+    pub fn intern(self) -> CheckCfg<Symbol> {
         CheckCfg {
             exhaustive_names: self.exhaustive_names,
             exhaustive_values: self.exhaustive_values,
@@ -1395,10 +1396,10 @@ impl<T> CheckCfg<T> {
                 .into_iter()
                 .map(|(name, values)| {
                     (
-                        f(name),
+                        Symbol::intern(&name),
                         match values {
                             ExpectedValues::Some(values) => ExpectedValues::Some(
-                                values.into_iter().map(|b| b.map(|b| f(b))).collect(),
+                                values.into_iter().map(|b| b.map(|b| Symbol::intern(&b))).collect(),
                             ),
                             ExpectedValues::Any => ExpectedValues::Any,
                         },
@@ -1441,14 +1442,7 @@ impl<'a, T: Eq + Hash + Copy + 'a> Extend<&'a T> for ExpectedValues<T> {
     }
 }
 
-/// Converts the crate `--check-cfg` options from `String` to `Symbol`.
-/// `rustc_interface::interface::Config` accepts this in the compiler configuration,
-/// but the symbol interner is not yet set up then, so we must convert it later.
-pub fn to_crate_check_config(cfg: CheckCfg) -> CrateCheckConfig {
-    cfg.map_data(|s| Symbol::intern(&s))
-}
-
-impl CrateCheckConfig {
+impl CheckCfg<Symbol> {
     pub fn fill_well_known(&mut self, current_target: &Target) {
         if !self.exhaustive_values && !self.exhaustive_names {
             return;
@@ -1588,7 +1582,13 @@ impl CrateCheckConfig {
     }
 }
 
-pub fn build_configuration(sess: &Session, mut user_cfg: CrateConfig) -> CrateConfig {
+pub fn build_configuration(sess: &Session, user_cfg: Cfg<String>) -> Cfg<Symbol> {
+    // We can now intern these strings.
+    let mut user_cfg: Cfg<Symbol> = user_cfg
+        .into_iter()
+        .map(|(a, b)| (Symbol::intern(&a), b.map(|b| Symbol::intern(&b))))
+        .collect();
+
     // Combine the configuration requested by the session (command line) with
     // some default and generated configuration items.
     let default_cfg = default_configuration(sess);
diff --git a/compiler/rustc_session/src/lib.rs b/compiler/rustc_session/src/lib.rs
index 7da0bcf01bf..17ac3e991c5 100644
--- a/compiler/rustc_session/src/lib.rs
+++ b/compiler/rustc_session/src/lib.rs
@@ -43,6 +43,9 @@ pub mod output;
 
 pub use getopts;
 
+mod version;
+pub use version::RustcVersion;
+
 fluent_messages! { "../messages.ftl" }
 
 /// Requirements for a `StableHashingContext` to be used in this crate.
diff --git a/compiler/rustc_session/src/options.rs b/compiler/rustc_session/src/options.rs
index fd473acbd3c..df92d8262e3 100644
--- a/compiler/rustc_session/src/options.rs
+++ b/compiler/rustc_session/src/options.rs
@@ -1492,9 +1492,6 @@ options! {
     dep_info_omit_d_target: bool = (false, parse_bool, [TRACKED],
         "in dep-info output, omit targets for tracking dependencies of the dep-info files \
         themselves (default: no)"),
-    dep_tasks: bool = (false, parse_bool, [UNTRACKED],
-        "print tasks that execute and the color their dep node gets (requires debug build) \
-        (default: no)"),
     dont_buffer_diagnostics: bool = (false, parse_bool, [UNTRACKED],
         "emit diagnostics rather than buffering (breaks NLL error downgrading, sorting) \
         (default: no)"),
diff --git a/compiler/rustc_session/src/parse.rs b/compiler/rustc_session/src/parse.rs
index abb0ab5630c..5b98ee5d992 100644
--- a/compiler/rustc_session/src/parse.rs
+++ b/compiler/rustc_session/src/parse.rs
@@ -1,7 +1,7 @@
 //! Contains `ParseSess` which holds state living beyond what one `Parser` might.
 //! It also serves as an input to the parser itself.
 
-use crate::config::CheckCfg;
+use crate::config::{Cfg, CheckCfg};
 use crate::errors::{
     CliFeatureDiagnosticHelp, FeatureDiagnosticForIssue, FeatureDiagnosticHelp, FeatureGateError,
 };
@@ -9,7 +9,7 @@ use crate::lint::{
     builtin::UNSTABLE_SYNTAX_PRE_EXPANSION, BufferedEarlyLint, BuiltinLintDiagnostics, Lint, LintId,
 };
 use rustc_ast::node_id::NodeId;
-use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexSet};
+use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_data_structures::sync::{AppendOnlyVec, Lock, Lrc};
 use rustc_errors::{emitter::SilentEmitter, Handler};
 use rustc_errors::{
@@ -25,11 +25,6 @@ use rustc_span::{Span, Symbol};
 use rustc_ast::attr::AttrIdGenerator;
 use std::str;
 
-/// The set of keys (and, optionally, values) that define the compilation
-/// environment of the crate, used to drive conditional compilation.
-pub type CrateConfig = FxIndexSet<(Symbol, Option<Symbol>)>;
-pub type CrateCheckConfig = CheckCfg<Symbol>;
-
 /// Collected spans during parsing for places where a certain feature was
 /// used and should be feature gated accordingly in `check_crate`.
 #[derive(Default)]
@@ -193,8 +188,8 @@ pub fn add_feature_diagnostics_for_issue(
 pub struct ParseSess {
     pub span_diagnostic: Handler,
     pub unstable_features: UnstableFeatures,
-    pub config: CrateConfig,
-    pub check_config: CrateCheckConfig,
+    pub config: Cfg<Symbol>,
+    pub check_config: CheckCfg<Symbol>,
     pub edition: Edition,
     /// Places where raw identifiers were used. This is used to avoid complaining about idents
     /// clashing with keywords in new editions.
@@ -237,8 +232,8 @@ impl ParseSess {
         Self {
             span_diagnostic: handler,
             unstable_features: UnstableFeatures::from_environment(None),
-            config: FxIndexSet::default(),
-            check_config: CrateCheckConfig::default(),
+            config: Cfg::default(),
+            check_config: CheckCfg::default(),
             edition: ExpnId::root().expn_data().edition,
             raw_identifier_spans: Default::default(),
             bad_unicode_identifiers: Lock::new(Default::default()),
diff --git a/compiler/rustc_session/src/version.rs b/compiler/rustc_session/src/version.rs
new file mode 100644
index 00000000000..1ad8620bfba
--- /dev/null
+++ b/compiler/rustc_session/src/version.rs
@@ -0,0 +1,19 @@
+use std::fmt::{self, Display};
+
+#[derive(Encodable, Decodable, Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
+#[derive(HashStable_Generic)]
+pub struct RustcVersion {
+    pub major: u16,
+    pub minor: u16,
+    pub patch: u16,
+}
+
+impl RustcVersion {
+    pub const CURRENT: Self = current_rustc_version!(env!("CFG_RELEASE"));
+}
+
+impl Display for RustcVersion {
+    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(formatter, "{}.{}.{}", self.major, self.minor, self.patch)
+    }
+}
diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
index 947ea3eece3..aad07d7683a 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
@@ -2691,8 +2691,6 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                         if let DefKind::Trait = tcx.def_kind(item_def_id)
                             && !visible_item
                         {
-                            // FIXME(estebank): extend this to search for all the types that do
-                            // implement this trait and list them.
                             err.note(format!(
                                 "`{short_item_name}` is a \"sealed trait\", because to implement \
                                  it you also need to implement `{}`, which is not accessible; \
@@ -2700,6 +2698,34 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                                  types that already implement it",
                                 with_no_trimmed_paths!(tcx.def_path_str(def_id)),
                             ));
+                            let impls_of = tcx.trait_impls_of(def_id);
+                            let impls = impls_of
+                                .non_blanket_impls()
+                                .values()
+                                .flatten()
+                                .chain(impls_of.blanket_impls().iter())
+                                .collect::<Vec<_>>();
+                            if !impls.is_empty() {
+                                let len = impls.len();
+                                let mut types = impls.iter()
+                                    .map(|t| with_no_trimmed_paths!(format!(
+                                        "  {}",
+                                        tcx.type_of(*t).instantiate_identity(),
+                                    )))
+                                    .collect::<Vec<_>>();
+                                let post = if types.len() > 9 {
+                                    types.truncate(8);
+                                    format!("\nand {} others", len - 8)
+                                } else {
+                                    String::new()
+                                };
+                                err.help(format!(
+                                    "the following type{} implement{} the trait:\n{}{post}",
+                                    pluralize!(len),
+                                    if len == 1 { "s" } else { "" },
+                                    types.join("\n"),
+                                ));
+                            }
                         }
                     }
                 } else {
diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/type_err_ctxt_ext.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/type_err_ctxt_ext.rs
index 7d6aa657104..af27f5cf4cb 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/type_err_ctxt_ext.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/type_err_ctxt_ext.rs
@@ -426,14 +426,18 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                             return;
                         }
                         let trait_ref = trait_predicate.to_poly_trait_ref();
-
-                        let (post_message, pre_message, type_def) = self
+                        let (post_message, pre_message, type_def, file_note) = self
                             .get_parent_trait_ref(obligation.cause.code())
                             .map(|(t, s)| {
+                                let (t, file) = self.tcx.short_ty_string(t);
                                 (
                                     format!(" in `{t}`"),
                                     format!("within `{t}`, "),
                                     s.map(|s| (format!("within this `{t}`"), s)),
+                                    file.map(|file| format!(
+                                        "the full trait has been written to '{}'",
+                                        file.display(),
+                                    ))
                                 )
                             })
                             .unwrap_or_default();
@@ -541,6 +545,8 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                             err.emit();
                             return;
                         }
+
+                        file_note.map(|note| err.note(note));
                         if let Some(s) = label {
                             // If it has a custom `#[rustc_on_unimplemented]`
                             // error message, let's display it as the label!
@@ -1094,7 +1100,7 @@ pub(super) trait InferCtxtPrivExt<'tcx> {
     fn get_parent_trait_ref(
         &self,
         code: &ObligationCauseCode<'tcx>,
-    ) -> Option<(String, Option<Span>)>;
+    ) -> Option<(Ty<'tcx>, Option<Span>)>;
 
     /// If the `Self` type of the unsatisfied trait `trait_ref` implements a trait
     /// with the same path as `trait_ref`, a help message about
@@ -1943,7 +1949,7 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
     fn get_parent_trait_ref(
         &self,
         code: &ObligationCauseCode<'tcx>,
-    ) -> Option<(String, Option<Span>)> {
+    ) -> Option<(Ty<'tcx>, Option<Span>)> {
         match code {
             ObligationCauseCode::BuiltinDerivedObligation(data) => {
                 let parent_trait_ref = self.resolve_vars_if_possible(data.parent_trait_pred);
@@ -1953,7 +1959,7 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                         let ty = parent_trait_ref.skip_binder().self_ty();
                         let span = TyCategory::from_ty(self.tcx, ty)
                             .map(|(_, def_id)| self.tcx.def_span(def_id));
-                        Some((ty.to_string(), span))
+                        Some((ty, span))
                     }
                 }
             }
diff --git a/compiler/rustc_ty_utils/src/layout_sanity_check.rs b/compiler/rustc_ty_utils/src/layout_sanity_check.rs
index 8633334381a..6332c614a90 100644
--- a/compiler/rustc_ty_utils/src/layout_sanity_check.rs
+++ b/compiler/rustc_ty_utils/src/layout_sanity_check.rs
@@ -19,6 +19,9 @@ pub(super) fn sanity_check_layout<'tcx>(
     if layout.size.bytes() % layout.align.abi.bytes() != 0 {
         bug!("size is not a multiple of align, in the following layout:\n{layout:#?}");
     }
+    if layout.size.bytes() >= cx.tcx.data_layout.obj_size_bound() {
+        bug!("size is too large, in the following layout:\n{layout:#?}");
+    }
 
     if !cfg!(debug_assertions) {
         // Stop here, the rest is kind of expensive.
diff --git a/library/std/src/sys/windows/api.rs b/library/std/src/sys/windows/api.rs
new file mode 100644
index 00000000000..e9f0bbfbe2e
--- /dev/null
+++ b/library/std/src/sys/windows/api.rs
@@ -0,0 +1,157 @@
+//! # Safe(r) wrappers around Windows API functions.
+//!
+//! This module contains fairly thin wrappers around Windows API functions,
+//! aimed at centralising safety instead of having unsafe blocks spread
+//! throughout higher level code. This makes it much easier to audit FFI safety.
+//!
+//! Not all functions can be made completely safe without more context but in
+//! such cases we should still endeavour to reduce the caller's burden of safety
+//! as much as possible.
+//!
+//! ## Guidelines for wrappers
+//!
+//! Items here should be named similarly to their raw Windows API name, except
+//! that they follow Rust's case conventions. E.g. function names are
+//! lower_snake_case. The idea here is that it should be easy for a Windows
+//! C/C++ programmer to identify the underlying function that's being wrapped
+//! while not looking too out of place in Rust code.
+//!
+//! Every use of an `unsafe` block must have a related SAFETY comment, even if
+//! it's trivially safe (for example, see `get_last_error`). Public unsafe
+//! functions must document what the caller has to do to call them safely.
+//!
+//! Avoid unchecked `as` casts. For integers, either assert that the integer
+//! is in range or use `try_into` instead. For pointers, prefer to use
+//! `ptr.cast::<Type>()` when possible.
+//!
+//! This module must only depend on core and not on std types as the eventual
+//! hope is to have std depend on sys and not the other way around.
+//! However, some amount of glue code may currently be necessary so such code
+//! should go in sys/windows/mod.rs rather than here. See `IoResult` as an example.
+
+use core::ffi::c_void;
+use core::ptr::addr_of;
+
+use super::c;
+
+/// Helper method for getting the size of `T` as a u32.
+/// Errors at compile time if the size would overflow.
+///
+/// While a type larger than u32::MAX is unlikely, it is possible if only because of a bug.
+/// However, one key motivation for this function is to avoid the temptation to
+/// use frequent `as` casts. This is risky because they are too powerful.
+/// For example, the following will compile today:
+///
+/// `std::mem::size_of::<u64> as u32`
+///
+/// Note that `size_of` is never actually called, instead a function pointer is
+/// converted to a `u32`. Clippy would warn about this but, alas, it's not run
+/// on the standard library.
+const fn win32_size_of<T: Sized>() -> u32 {
+    // Const assert that the size is less than u32::MAX.
+    // Uses a trait to workaround restriction on using generic types in inner items.
+    trait Win32SizeOf: Sized {
+        const WIN32_SIZE_OF: u32 = {
+            let size = core::mem::size_of::<Self>();
+            assert!(size <= u32::MAX as usize);
+            size as u32
+        };
+    }
+    impl<T: Sized> Win32SizeOf for T {}
+
+    T::WIN32_SIZE_OF
+}
+
+/// The `SetFileInformationByHandle` function takes a generic parameter by
+/// making the user specify the type (class), a pointer to the data and its
+/// size. This trait allows attaching that information to a Rust type so that
+/// [`set_file_information_by_handle`] can be called safely.
+///
+/// This trait is designed so that it can support variable sized types.
+/// However, currently Rust's std only uses fixed sized structures.
+///
+/// # Safety
+///
+/// * `as_ptr` must return a pointer to memory that is readable up to `size` bytes.
+/// * `CLASS` must accurately reflect the type pointed to by `as_ptr`. E.g.
+/// the `FILE_BASIC_INFO` structure has the class `FileBasicInfo`.
+pub unsafe trait SetFileInformation {
+    /// The type of information to set.
+    const CLASS: i32;
+    /// A pointer to the file information to set.
+    fn as_ptr(&self) -> *const c_void;
+    /// The size of the type pointed to by `as_ptr`.
+    fn size(&self) -> u32;
+}
+/// Helper trait for implementing `SetFileInformation` for statically sized types.
+unsafe trait SizedSetFileInformation: Sized {
+    const CLASS: i32;
+}
+unsafe impl<T: SizedSetFileInformation> SetFileInformation for T {
+    const CLASS: i32 = T::CLASS;
+    fn as_ptr(&self) -> *const c_void {
+        addr_of!(*self).cast::<c_void>()
+    }
+    fn size(&self) -> u32 {
+        win32_size_of::<Self>()
+    }
+}
+
+// SAFETY: FILE_BASIC_INFO, FILE_END_OF_FILE_INFO, FILE_ALLOCATION_INFO,
+// FILE_DISPOSITION_INFO, FILE_DISPOSITION_INFO_EX and FILE_IO_PRIORITY_HINT_INFO
+// are all plain `repr(C)` structs that only contain primitive types.
+// The given information classes correctly match with the struct.
+unsafe impl SizedSetFileInformation for c::FILE_BASIC_INFO {
+    const CLASS: i32 = c::FileBasicInfo;
+}
+unsafe impl SizedSetFileInformation for c::FILE_END_OF_FILE_INFO {
+    const CLASS: i32 = c::FileEndOfFileInfo;
+}
+unsafe impl SizedSetFileInformation for c::FILE_ALLOCATION_INFO {
+    const CLASS: i32 = c::FileAllocationInfo;
+}
+unsafe impl SizedSetFileInformation for c::FILE_DISPOSITION_INFO {
+    const CLASS: i32 = c::FileDispositionInfo;
+}
+unsafe impl SizedSetFileInformation for c::FILE_DISPOSITION_INFO_EX {
+    const CLASS: i32 = c::FileDispositionInfoEx;
+}
+unsafe impl SizedSetFileInformation for c::FILE_IO_PRIORITY_HINT_INFO {
+    const CLASS: i32 = c::FileIoPriorityHintInfo;
+}
+
+#[inline]
+pub fn set_file_information_by_handle<T: SetFileInformation>(
+    handle: c::HANDLE,
+    info: &T,
+) -> Result<(), WinError> {
+    unsafe fn set_info(
+        handle: c::HANDLE,
+        class: i32,
+        info: *const c_void,
+        size: u32,
+    ) -> Result<(), WinError> {
+        let result = c::SetFileInformationByHandle(handle, class, info, size);
+        (result != 0).then_some(()).ok_or_else(|| get_last_error())
+    }
+    // SAFETY: The `SetFileInformation` trait ensures that this is safe.
+    unsafe { set_info(handle, T::CLASS, info.as_ptr(), info.size()) }
+}
+
+/// Gets the error from the last function.
+/// This must be called immediately after the function that sets the error to
+/// avoid the risk of another function overwriting it.
+pub fn get_last_error() -> WinError {
+    // SAFETY: This just returns a thread-local u32 and has no other effects.
+    unsafe { WinError { code: c::GetLastError() } }
+}
+
+/// An error code as returned by [`get_last_error`].
+///
+/// This is usually a 16-bit Win32 error code but may be a 32-bit HRESULT or NTSTATUS.
+/// Check the documentation of the Windows API function being called for expected errors.
+#[derive(Clone, Copy, PartialEq, Eq)]
+#[repr(transparent)]
+pub struct WinError {
+    pub code: u32,
+}
diff --git a/library/std/src/sys/windows/c/windows_sys.lst b/library/std/src/sys/windows/c/windows_sys.lst
index 78b1988afeb..38bf15b7c72 100644
--- a/library/std/src/sys/windows/c/windows_sys.lst
+++ b/library/std/src/sys/windows/c/windows_sys.lst
@@ -2224,6 +2224,7 @@ Windows.Win32.Storage.FileSystem.FILE_ACCESS_RIGHTS
 Windows.Win32.Storage.FileSystem.FILE_ADD_FILE
 Windows.Win32.Storage.FileSystem.FILE_ADD_SUBDIRECTORY
 Windows.Win32.Storage.FileSystem.FILE_ALL_ACCESS
+Windows.Win32.Storage.FileSystem.FILE_ALLOCATION_INFO
 Windows.Win32.Storage.FileSystem.FILE_APPEND_DATA
 Windows.Win32.Storage.FileSystem.FILE_ATTRIBUTE_ARCHIVE
 Windows.Win32.Storage.FileSystem.FILE_ATTRIBUTE_COMPRESSED
@@ -2284,6 +2285,7 @@ Windows.Win32.Storage.FileSystem.FILE_GENERIC_READ
 Windows.Win32.Storage.FileSystem.FILE_GENERIC_WRITE
 Windows.Win32.Storage.FileSystem.FILE_ID_BOTH_DIR_INFO
 Windows.Win32.Storage.FileSystem.FILE_INFO_BY_HANDLE_CLASS
+Windows.Win32.Storage.FileSystem.FILE_IO_PRIORITY_HINT_INFO
 Windows.Win32.Storage.FileSystem.FILE_LIST_DIRECTORY
 Windows.Win32.Storage.FileSystem.FILE_NAME_NORMALIZED
 Windows.Win32.Storage.FileSystem.FILE_NAME_OPENED
diff --git a/library/std/src/sys/windows/c/windows_sys.rs b/library/std/src/sys/windows/c/windows_sys.rs
index 9ecd45e09ff..e0509e6a5dd 100644
--- a/library/std/src/sys/windows/c/windows_sys.rs
+++ b/library/std/src/sys/windows/c/windows_sys.rs
@@ -3129,6 +3129,16 @@ impl ::core::clone::Clone for FILETIME {
 pub type FILE_ACCESS_RIGHTS = u32;
 pub const FILE_ADD_FILE: FILE_ACCESS_RIGHTS = 2u32;
 pub const FILE_ADD_SUBDIRECTORY: FILE_ACCESS_RIGHTS = 4u32;
+#[repr(C)]
+pub struct FILE_ALLOCATION_INFO {
+    pub AllocationSize: i64,
+}
+impl ::core::marker::Copy for FILE_ALLOCATION_INFO {}
+impl ::core::clone::Clone for FILE_ALLOCATION_INFO {
+    fn clone(&self) -> Self {
+        *self
+    }
+}
 pub const FILE_ALL_ACCESS: FILE_ACCESS_RIGHTS = 2032127u32;
 pub const FILE_APPEND_DATA: FILE_ACCESS_RIGHTS = 4u32;
 pub const FILE_ATTRIBUTE_ARCHIVE: FILE_FLAGS_AND_ATTRIBUTES = 32u32;
@@ -3270,6 +3280,16 @@ impl ::core::clone::Clone for FILE_ID_BOTH_DIR_INFO {
     }
 }
 pub type FILE_INFO_BY_HANDLE_CLASS = i32;
+#[repr(C)]
+pub struct FILE_IO_PRIORITY_HINT_INFO {
+    pub PriorityHint: PRIORITY_HINT,
+}
+impl ::core::marker::Copy for FILE_IO_PRIORITY_HINT_INFO {}
+impl ::core::clone::Clone for FILE_IO_PRIORITY_HINT_INFO {
+    fn clone(&self) -> Self {
+        *self
+    }
+}
 pub const FILE_LIST_DIRECTORY: FILE_ACCESS_RIGHTS = 1u32;
 pub const FILE_NAME_NORMALIZED: GETFINALPATHNAMEBYHANDLE_FLAGS = 0u32;
 pub const FILE_NAME_OPENED: GETFINALPATHNAMEBYHANDLE_FLAGS = 8u32;
@@ -3775,6 +3795,7 @@ pub const PIPE_SERVER_END: NAMED_PIPE_MODE = 1u32;
 pub const PIPE_TYPE_BYTE: NAMED_PIPE_MODE = 0u32;
 pub const PIPE_TYPE_MESSAGE: NAMED_PIPE_MODE = 4u32;
 pub const PIPE_WAIT: NAMED_PIPE_MODE = 0u32;
+pub type PRIORITY_HINT = i32;
 pub type PROCESSOR_ARCHITECTURE = u16;
 pub type PROCESS_CREATION_FLAGS = u32;
 #[repr(C)]
diff --git a/library/std/src/sys/windows/fs.rs b/library/std/src/sys/windows/fs.rs
index 22f2b1007ef..d7e36b9a3ff 100644
--- a/library/std/src/sys/windows/fs.rs
+++ b/library/std/src/sys/windows/fs.rs
@@ -19,7 +19,7 @@ use crate::thread;
 use core::ffi::c_void;
 
 use super::path::maybe_verbatim;
-use super::to_u16s;
+use super::{api, to_u16s, IoResult};
 
 pub struct File {
     handle: Handle,
@@ -123,7 +123,7 @@ impl Iterator for ReadDir {
             let mut wfd = mem::zeroed();
             loop {
                 if c::FindNextFileW(self.handle.0, &mut wfd) == 0 {
-                    if c::GetLastError() == c::ERROR_NO_MORE_FILES {
+                    if api::get_last_error().code == c::ERROR_NO_MORE_FILES {
                         return None;
                     } else {
                         return Some(Err(Error::last_os_error()));
@@ -318,17 +318,8 @@ impl File {
     }
 
     pub fn truncate(&self, size: u64) -> io::Result<()> {
-        let mut info = c::FILE_END_OF_FILE_INFO { EndOfFile: size as c::LARGE_INTEGER };
-        let size = mem::size_of_val(&info);
-        cvt(unsafe {
-            c::SetFileInformationByHandle(
-                self.handle.as_raw_handle(),
-                c::FileEndOfFileInfo,
-                &mut info as *mut _ as *mut _,
-                size as c::DWORD,
-            )
-        })?;
-        Ok(())
+        let info = c::FILE_END_OF_FILE_INFO { EndOfFile: size as i64 };
+        api::set_file_information_by_handle(self.handle.as_raw_handle(), &info).io_result()
     }
 
     #[cfg(not(target_vendor = "uwp"))]
@@ -565,23 +556,14 @@ impl File {
     }
 
     pub fn set_permissions(&self, perm: FilePermissions) -> io::Result<()> {
-        let mut info = c::FILE_BASIC_INFO {
+        let info = c::FILE_BASIC_INFO {
             CreationTime: 0,
             LastAccessTime: 0,
             LastWriteTime: 0,
             ChangeTime: 0,
             FileAttributes: perm.attrs,
         };
-        let size = mem::size_of_val(&info);
-        cvt(unsafe {
-            c::SetFileInformationByHandle(
-                self.handle.as_raw_handle(),
-                c::FileBasicInfo,
-                &mut info as *mut _ as *mut _,
-                size as c::DWORD,
-            )
-        })?;
-        Ok(())
+        api::set_file_information_by_handle(self.handle.as_raw_handle(), &info).io_result()
     }
 
     pub fn set_times(&self, times: FileTimes) -> io::Result<()> {
@@ -641,38 +623,20 @@ impl File {
     /// If the operation is not supported for this filesystem or OS version
     /// then errors will be `ERROR_NOT_SUPPORTED` or `ERROR_INVALID_PARAMETER`.
     fn posix_delete(&self) -> io::Result<()> {
-        let mut info = c::FILE_DISPOSITION_INFO_EX {
+        let info = c::FILE_DISPOSITION_INFO_EX {
             Flags: c::FILE_DISPOSITION_FLAG_DELETE
                 | c::FILE_DISPOSITION_FLAG_POSIX_SEMANTICS
                 | c::FILE_DISPOSITION_FLAG_IGNORE_READONLY_ATTRIBUTE,
         };
-        let size = mem::size_of_val(&info);
-        cvt(unsafe {
-            c::SetFileInformationByHandle(
-                self.handle.as_raw_handle(),
-                c::FileDispositionInfoEx,
-                &mut info as *mut _ as *mut _,
-                size as c::DWORD,
-            )
-        })?;
-        Ok(())
+        api::set_file_information_by_handle(self.handle.as_raw_handle(), &info).io_result()
     }
 
     /// Delete a file using win32 semantics. The file won't actually be deleted
     /// until all file handles are closed. However, marking a file for deletion
     /// will prevent anyone from opening a new handle to the file.
     fn win32_delete(&self) -> io::Result<()> {
-        let mut info = c::FILE_DISPOSITION_INFO { DeleteFile: c::TRUE as _ };
-        let size = mem::size_of_val(&info);
-        cvt(unsafe {
-            c::SetFileInformationByHandle(
-                self.handle.as_raw_handle(),
-                c::FileDispositionInfo,
-                &mut info as *mut _ as *mut _,
-                size as c::DWORD,
-            )
-        })?;
-        Ok(())
+        let info = c::FILE_DISPOSITION_INFO { DeleteFile: c::TRUE as _ };
+        api::set_file_information_by_handle(self.handle.as_raw_handle(), &info).io_result()
     }
 
     /// Fill the given buffer with as many directory entries as will fit.
diff --git a/library/std/src/sys/windows/mod.rs b/library/std/src/sys/windows/mod.rs
index b609ad2472c..c4e56e13be3 100644
--- a/library/std/src/sys/windows/mod.rs
+++ b/library/std/src/sys/windows/mod.rs
@@ -44,6 +44,18 @@ cfg_if::cfg_if! {
     }
 }
 
+mod api;
+
+/// Map a Result<T, WinError> to io::Result<T>.
+trait IoResult<T> {
+    fn io_result(self) -> crate::io::Result<T>;
+}
+impl<T> IoResult<T> for Result<T, api::WinError> {
+    fn io_result(self) -> crate::io::Result<T> {
+        self.map_err(|e| crate::io::Error::from_raw_os_error(e.code as i32))
+    }
+}
+
 // SAFETY: must be called only once during runtime initialization.
 // NOTE: this is not guaranteed to run, for example when Rust code is called externally.
 pub unsafe fn init(_argc: isize, _argv: *const *const u8, _sigpipe: u8) {
@@ -241,11 +253,11 @@ where
             // not an actual error.
             c::SetLastError(0);
             let k = match f1(buf.as_mut_ptr().cast::<u16>(), n as c::DWORD) {
-                0 if c::GetLastError() == 0 => 0,
+                0 if api::get_last_error().code == 0 => 0,
                 0 => return Err(crate::io::Error::last_os_error()),
                 n => n,
             } as usize;
-            if k == n && c::GetLastError() == c::ERROR_INSUFFICIENT_BUFFER {
+            if k == n && api::get_last_error().code == c::ERROR_INSUFFICIENT_BUFFER {
                 n = n.saturating_mul(2).min(c::DWORD::MAX as usize);
             } else if k > n {
                 n = k;
diff --git a/library/std/src/sys/windows/os.rs b/library/std/src/sys/windows/os.rs
index 58afca088ef..8cc905101de 100644
--- a/library/std/src/sys/windows/os.rs
+++ b/library/std/src/sys/windows/os.rs
@@ -17,10 +17,10 @@ use crate::ptr;
 use crate::slice;
 use crate::sys::{c, cvt};
 
-use super::to_u16s;
+use super::{api, to_u16s};
 
 pub fn errno() -> i32 {
-    unsafe { c::GetLastError() as i32 }
+    api::get_last_error().code as i32
 }
 
 /// Gets a detailed string description for the given error number.
@@ -336,7 +336,7 @@ fn home_dir_crt() -> Option<PathBuf> {
         super::fill_utf16_buf(
             |buf, mut sz| {
                 match c::GetUserProfileDirectoryW(token, buf, &mut sz) {
-                    0 if c::GetLastError() != c::ERROR_INSUFFICIENT_BUFFER => 0,
+                    0 if api::get_last_error().code != c::ERROR_INSUFFICIENT_BUFFER => 0,
                     0 => sz,
                     _ => sz - 1, // sz includes the null terminator
                 }
diff --git a/library/std/src/sys/windows/stack_overflow.rs b/library/std/src/sys/windows/stack_overflow.rs
index 0caf0a317a4..627763da856 100644
--- a/library/std/src/sys/windows/stack_overflow.rs
+++ b/library/std/src/sys/windows/stack_overflow.rs
@@ -3,6 +3,8 @@
 use crate::sys::c;
 use crate::thread;
 
+use super::api;
+
 pub struct Handler;
 
 impl Handler {
@@ -10,7 +12,7 @@ impl Handler {
         // This API isn't available on XP, so don't panic in that case and just
         // pray it works out ok.
         if c::SetThreadStackGuarantee(&mut 0x5000) == 0
-            && c::GetLastError() as u32 != c::ERROR_CALL_NOT_IMPLEMENTED as u32
+            && api::get_last_error().code != c::ERROR_CALL_NOT_IMPLEMENTED
         {
             panic!("failed to reserve stack space for exception handling");
         }
diff --git a/library/std/src/sys/windows/stdio.rs b/library/std/src/sys/windows/stdio.rs
index 3fcaaa508e3..a9ff909aa67 100644
--- a/library/std/src/sys/windows/stdio.rs
+++ b/library/std/src/sys/windows/stdio.rs
@@ -9,6 +9,7 @@ use crate::str;
 use crate::sys::c;
 use crate::sys::cvt;
 use crate::sys::handle::Handle;
+use crate::sys::windows::api;
 use core::str::utf8_char_width;
 
 #[cfg(test)]
@@ -369,7 +370,7 @@ fn read_u16s(handle: c::HANDLE, buf: &mut [MaybeUninit<u16>]) -> io::Result<usiz
 
         // ReadConsoleW returns success with ERROR_OPERATION_ABORTED for Ctrl-C or Ctrl-Break.
         // Explicitly check for that case here and try again.
-        if amount == 0 && unsafe { c::GetLastError() } == c::ERROR_OPERATION_ABORTED {
+        if amount == 0 && api::get_last_error().code == c::ERROR_OPERATION_ABORTED {
             continue;
         }
         break;
diff --git a/src/doc/unstable-book/src/compiler-flags/check-cfg.md b/src/doc/unstable-book/src/compiler-flags/check-cfg.md
index 7a3ef5e9e2b..0e15c79076f 100644
--- a/src/doc/unstable-book/src/compiler-flags/check-cfg.md
+++ b/src/doc/unstable-book/src/compiler-flags/check-cfg.md
@@ -139,7 +139,7 @@ fn do_mumble_frotz() {}
 
 ```bash
 # This turns on checking for feature values, but not for condition names.
-rustc --check-cfg 'configure(feature, values("zapping", "lasers"))' \
+rustc --check-cfg 'cfg(feature, values("zapping", "lasers"))' \
       --check-cfg 'cfg(any())' \
       --cfg 'feature="zapping"' -Z unstable-options
 ```
diff --git a/src/librustdoc/core.rs b/src/librustdoc/core.rs
index 94e557dcfdb..bcc61df7c4d 100644
--- a/src/librustdoc/core.rs
+++ b/src/librustdoc/core.rs
@@ -255,7 +255,7 @@ pub(crate) fn create_config(
 
     interface::Config {
         opts: sessopts,
-        crate_cfg: interface::parse_cfgspecs(handler, cfgs),
+        crate_cfg: interface::parse_cfg(handler, cfgs),
         crate_check_cfg: interface::parse_check_cfg(handler, check_cfgs),
         input,
         output_file: None,
diff --git a/src/librustdoc/doctest.rs b/src/librustdoc/doctest.rs
index 97913345e8f..c61c98e4de9 100644
--- a/src/librustdoc/doctest.rs
+++ b/src/librustdoc/doctest.rs
@@ -92,7 +92,7 @@ pub(crate) fn run(options: RustdocOptions) -> Result<(), ErrorGuaranteed> {
     cfgs.push("doctest".to_owned());
     let config = interface::Config {
         opts: sessopts,
-        crate_cfg: interface::parse_cfgspecs(&early_error_handler, cfgs),
+        crate_cfg: interface::parse_cfg(&early_error_handler, cfgs),
         crate_check_cfg: interface::parse_check_cfg(
             &early_error_handler,
             options.check_cfgs.clone(),
diff --git a/src/librustdoc/html/render/mod.rs b/src/librustdoc/html/render/mod.rs
index d9086433608..0b6079b2933 100644
--- a/src/librustdoc/html/render/mod.rs
+++ b/src/librustdoc/html/render/mod.rs
@@ -48,13 +48,14 @@ use std::str;
 use std::string::ToString;
 
 use askama::Template;
-use rustc_attr::{ConstStability, Deprecation, Since, StabilityLevel, CURRENT_RUSTC_VERSION};
+use rustc_attr::{ConstStability, Deprecation, Since, StabilityLevel};
 use rustc_data_structures::captures::Captures;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_hir::def_id::{DefId, DefIdSet};
 use rustc_hir::Mutability;
 use rustc_middle::middle::stability;
 use rustc_middle::ty::{self, TyCtxt};
+use rustc_session::RustcVersion;
 use rustc_span::{
     symbol::{sym, Symbol},
     BytePos, FileName, RealFileName,
@@ -979,7 +980,7 @@ fn render_stability_since_raw_with_extra(
 fn since_to_string(since: &Since) -> Option<String> {
     match since {
         Since::Version(since) => Some(since.to_string()),
-        Since::Current => Some(CURRENT_RUSTC_VERSION.to_owned()),
+        Since::Current => Some(RustcVersion::CURRENT.to_string()),
         Since::Err => None,
     }
 }
diff --git a/src/tools/clippy/clippy_utils/src/qualify_min_const_fn.rs b/src/tools/clippy/clippy_utils/src/qualify_min_const_fn.rs
index 1e465ac91b7..31f7b87de63 100644
--- a/src/tools/clippy/clippy_utils/src/qualify_min_const_fn.rs
+++ b/src/tools/clippy/clippy_utils/src/qualify_min_const_fn.rs
@@ -5,7 +5,7 @@
 
 use crate::msrvs::Msrv;
 use hir::LangItem;
-use rustc_attr::{Since, CURRENT_RUSTC_VERSION};
+use rustc_attr::Since;
 use rustc_const_eval::transform::check_consts::ConstCx;
 use rustc_hir as hir;
 use rustc_hir::def_id::DefId;
@@ -372,23 +372,16 @@ fn is_const_fn(tcx: TyCtxt<'_>, def_id: DefId, msrv: &Msrv) -> bool {
                 // as a part of an unimplemented MSRV check https://github.com/rust-lang/rust/issues/65262.
 
                 let const_stab_rust_version = match since {
-                    Since::Version(version) => RustcVersion::new(
-                        u32::from(version.major),
-                        u32::from(version.minor),
-                        u32::from(version.patch),
-                    ),
-                    Since::Current => {
-                        // HACK(nilstrieb): CURRENT_RUSTC_VERSION can return versions like 1.66.0-dev.
-                        // `rustc-semver` doesn't accept the `-dev` version number so we have to strip it off.
-                        let short_version = CURRENT_RUSTC_VERSION.split('-').next().unwrap();
-                        RustcVersion::parse(short_version).unwrap_or_else(|err| {
-                            panic!("`rustc_attr::StabilityLevel::Stable::since` is ill-formatted: `{CURRENT_RUSTC_VERSION}`, {err:?}")
-                        })
-                    },
+                    Since::Version(version) => version,
+                    Since::Current => rustc_session::RustcVersion::CURRENT,
                     Since::Err => return false,
                 };
 
-                msrv.meets(const_stab_rust_version)
+                msrv.meets(RustcVersion::new(
+                    u32::from(const_stab_rust_version.major),
+                    u32::from(const_stab_rust_version.minor),
+                    u32::from(const_stab_rust_version.patch),
+                ))
             } else {
                 // Unstable const fn with the feature enabled.
                 msrv.current().is_none()
diff --git a/tests/ui/check-cfg/invalid-arguments.any_values.stderr b/tests/ui/check-cfg/invalid-arguments.any_values.stderr
new file mode 100644
index 00000000000..f9a9c4a6e13
--- /dev/null
+++ b/tests/ui/check-cfg/invalid-arguments.any_values.stderr
@@ -0,0 +1,2 @@
+error: invalid `--check-cfg` argument: `cfg(any(),values())` (`values()` cannot be specified before the names)
+
diff --git a/tests/ui/check-cfg/invalid-arguments.rs b/tests/ui/check-cfg/invalid-arguments.rs
index 79bef89c957..a56f48e0af9 100644
--- a/tests/ui/check-cfg/invalid-arguments.rs
+++ b/tests/ui/check-cfg/invalid-arguments.rs
@@ -6,7 +6,7 @@
 // revisions: multiple_values_any not_empty_any not_empty_values_any
 // revisions: values_any_missing_values values_any_before_ident ident_in_values_1
 // revisions: ident_in_values_2 unknown_meta_item_1 unknown_meta_item_2 unknown_meta_item_3
-// revisions: mixed_values_any mixed_any giberich
+// revisions: mixed_values_any mixed_any any_values giberich unterminated
 //
 // compile-flags: -Z unstable-options
 // [anything_else]compile-flags: --check-cfg=anything_else(...)
@@ -29,6 +29,8 @@
 // [unknown_meta_item_3]compile-flags: --check-cfg=cfg(foo,values(test()))
 // [mixed_values_any]compile-flags: --check-cfg=cfg(foo,values("bar",any()))
 // [mixed_any]compile-flags: --check-cfg=cfg(any(),values(any()))
+// [any_values]compile-flags: --check-cfg=cfg(any(),values())
 // [giberich]compile-flags: --check-cfg=cfg(...)
+// [unterminated]compile-flags: --check-cfg=cfg(
 
 fn main() {}
diff --git a/tests/ui/check-cfg/invalid-arguments.unterminated.stderr b/tests/ui/check-cfg/invalid-arguments.unterminated.stderr
new file mode 100644
index 00000000000..80161a6aa0f
--- /dev/null
+++ b/tests/ui/check-cfg/invalid-arguments.unterminated.stderr
@@ -0,0 +1,2 @@
+error: invalid `--check-cfg` argument: `cfg(` (expected `cfg(name, values("value1", "value2", ... "valueN"))`)
+
diff --git a/tests/ui/layout/too-big-with-padding.rs b/tests/ui/layout/too-big-with-padding.rs
new file mode 100644
index 00000000000..cf41ac872c2
--- /dev/null
+++ b/tests/ui/layout/too-big-with-padding.rs
@@ -0,0 +1,18 @@
+// build-fail
+// compile-flags: --target i686-unknown-linux-gnu --crate-type lib
+// needs-llvm-components: x86
+#![feature(no_core, lang_items)]
+#![allow(internal_features)]
+#![no_std]
+#![no_core]
+
+// 0x7fffffff is fine, but after rounding up it becomes too big
+#[repr(C, align(2))]
+pub struct Example([u8; 0x7fffffff]);
+
+pub fn lib(_x: Example) {} //~ERROR: too big for the current architecture
+
+#[lang = "sized"]
+pub trait Sized {}
+#[lang = "copy"]
+pub trait Copy: Sized {}
diff --git a/tests/ui/layout/too-big-with-padding.stderr b/tests/ui/layout/too-big-with-padding.stderr
new file mode 100644
index 00000000000..5cc854adce0
--- /dev/null
+++ b/tests/ui/layout/too-big-with-padding.stderr
@@ -0,0 +1,8 @@
+error: values of the type `Example` are too big for the current architecture
+  --> $DIR/too-big-with-padding.rs:13:1
+   |
+LL | pub fn lib(_x: Example) {}
+   | ^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+
diff --git a/tests/ui/privacy/sealed-traits/sealed-trait-local.rs b/tests/ui/privacy/sealed-traits/sealed-trait-local.rs
index 778ddf0f817..9ae01259a78 100644
--- a/tests/ui/privacy/sealed-traits/sealed-trait-local.rs
+++ b/tests/ui/privacy/sealed-traits/sealed-trait-local.rs
@@ -13,7 +13,43 @@ pub mod a {
     }
 }
 
-struct S;
-impl a::Sealed for S {} //~ ERROR the trait bound `S: Hidden` is not satisfied
+pub mod c {
+    pub trait Sealed: self::d::Hidden {
+        fn foo() {}
+    }
+
+    struct X;
+    impl Sealed for X {}
+    impl self::d::Hidden for X {}
+
+    struct Y;
+    impl Sealed for Y {}
+    impl self::d::Hidden for Y {}
+
+    mod d {
+        pub trait Hidden {}
+    }
+}
 
+pub mod e {
+    pub trait Sealed: self::f::Hidden {
+        fn foo() {}
+    }
+
+    struct X;
+    impl self::f::Hidden for X {}
+
+    struct Y;
+    impl self::f::Hidden for Y {}
+    impl<T: self::f::Hidden> Sealed for T {}
+
+    mod f {
+        pub trait Hidden {}
+    }
+}
+
+struct S;
+impl a::Sealed for S {} //~ ERROR the trait bound
+impl c::Sealed for S {} //~ ERROR the trait bound
+impl e::Sealed for S {} //~ ERROR the trait bound
 fn main() {}
diff --git a/tests/ui/privacy/sealed-traits/sealed-trait-local.stderr b/tests/ui/privacy/sealed-traits/sealed-trait-local.stderr
index 5f8076fc84d..a7f77a1c0c0 100644
--- a/tests/ui/privacy/sealed-traits/sealed-trait-local.stderr
+++ b/tests/ui/privacy/sealed-traits/sealed-trait-local.stderr
@@ -1,16 +1,50 @@
-error[E0277]: the trait bound `S: Hidden` is not satisfied
-  --> $DIR/sealed-trait-local.rs:17:20
+error[E0277]: the trait bound `S: b::Hidden` is not satisfied
+  --> $DIR/sealed-trait-local.rs:52:20
    |
 LL | impl a::Sealed for S {}
-   |                    ^ the trait `Hidden` is not implemented for `S`
+   |                    ^ the trait `b::Hidden` is not implemented for `S`
    |
-note: required by a bound in `Sealed`
+note: required by a bound in `a::Sealed`
   --> $DIR/sealed-trait-local.rs:3:23
    |
 LL |     pub trait Sealed: self::b::Hidden {
    |                       ^^^^^^^^^^^^^^^ required by this bound in `Sealed`
    = note: `Sealed` is a "sealed trait", because to implement it you also need to implement `a::b::Hidden`, which is not accessible; this is usually done to force you to use one of the provided types that already implement it
+   = help: the following type implements the trait:
+             a::X
 
-error: aborting due to previous error
+error[E0277]: the trait bound `S: d::Hidden` is not satisfied
+  --> $DIR/sealed-trait-local.rs:53:20
+   |
+LL | impl c::Sealed for S {}
+   |                    ^ the trait `d::Hidden` is not implemented for `S`
+   |
+note: required by a bound in `c::Sealed`
+  --> $DIR/sealed-trait-local.rs:17:23
+   |
+LL |     pub trait Sealed: self::d::Hidden {
+   |                       ^^^^^^^^^^^^^^^ required by this bound in `Sealed`
+   = note: `Sealed` is a "sealed trait", because to implement it you also need to implement `c::d::Hidden`, which is not accessible; this is usually done to force you to use one of the provided types that already implement it
+   = help: the following types implement the trait:
+             c::X
+             c::Y
+
+error[E0277]: the trait bound `S: f::Hidden` is not satisfied
+  --> $DIR/sealed-trait-local.rs:54:20
+   |
+LL | impl e::Sealed for S {}
+   |                    ^ the trait `f::Hidden` is not implemented for `S`
+   |
+note: required by a bound in `e::Sealed`
+  --> $DIR/sealed-trait-local.rs:35:23
+   |
+LL |     pub trait Sealed: self::f::Hidden {
+   |                       ^^^^^^^^^^^^^^^ required by this bound in `Sealed`
+   = note: `Sealed` is a "sealed trait", because to implement it you also need to implement `e::f::Hidden`, which is not accessible; this is usually done to force you to use one of the provided types that already implement it
+   = help: the following types implement the trait:
+             e::X
+             e::Y
+
+error: aborting due to 3 previous errors
 
 For more information about this error, try `rustc --explain E0277`.