Auto merge of #111287 - matthiaskrgr:rollup-9lzax2c, r=matthiaskrgr

Rollup of 7 pull requests

Successful merges:

 - #110577 (Use fulfillment to check `Drop` impl compatibility)
 - #110610 (Add Terminator conversion from MIR to SMIR, part #1)
 - #110985 (Fix spans in LLVM-generated inline asm errors)
 - #110989 (Make the BUG_REPORT_URL configurable by tools )
 - #111167 (debuginfo: split method declaration and definition)
 - #111230 (add hint for =< as <=)
 - #111279 (More robust debug assertions for `Instance::resolve` on built-in traits with non-standard trait items)

Failed merges:

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

42 files changed, 1067 insertions, 413 deletions

diff --git a/Cargo.lock b/Cargo.lock
index d24a4271aa1..724587a4a71 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -4093,6 +4093,7 @@ dependencies = [
 name = "rustc_smir"
 version = "0.0.0"
 dependencies = [
+ "rustc_hir",
  "rustc_middle",
  "rustc_span",
  "tracing",
diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs b/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs
index 2e9f89f4196..b138b0c0e70 100644
--- a/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs
+++ b/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs
@@ -322,7 +322,7 @@ impl<'ll, 'tcx> DebugInfoMethods<'tcx> for CodegenCx<'ll, 'tcx> {
         let tcx = self.tcx;
 
         let def_id = instance.def_id();
-        let containing_scope = get_containing_scope(self, instance);
+        let (containing_scope, is_method) = get_containing_scope(self, instance);
         let span = tcx.def_span(def_id);
         let loc = self.lookup_debug_loc(span.lo());
         let file_metadata = file_metadata(self, &loc.file);
@@ -378,8 +378,29 @@ impl<'ll, 'tcx> DebugInfoMethods<'tcx> for CodegenCx<'ll, 'tcx> {
             }
         }
 
-        unsafe {
-            return llvm::LLVMRustDIBuilderCreateFunction(
+        // When we're adding a method to a type DIE, we only want a DW_AT_declaration there, because
+        // LLVM LTO can't unify type definitions when a child DIE is a full subprogram definition.
+        // When we use this `decl` below, the subprogram definition gets created at the CU level
+        // with a DW_AT_specification pointing back to the type's declaration.
+        let decl = is_method.then(|| unsafe {
+            llvm::LLVMRustDIBuilderCreateMethod(
+                DIB(self),
+                containing_scope,
+                name.as_ptr().cast(),
+                name.len(),
+                linkage_name.as_ptr().cast(),
+                linkage_name.len(),
+                file_metadata,
+                loc.line,
+                function_type_metadata,
+                flags,
+                spflags & !DISPFlags::SPFlagDefinition,
+                template_parameters,
+            )
+        });
+
+        return unsafe {
+            llvm::LLVMRustDIBuilderCreateFunction(
                 DIB(self),
                 containing_scope,
                 name.as_ptr().cast(),
@@ -394,9 +415,9 @@ impl<'ll, 'tcx> DebugInfoMethods<'tcx> for CodegenCx<'ll, 'tcx> {
                 spflags,
                 maybe_definition_llfn,
                 template_parameters,
-                None,
-            );
-        }
+                decl,
+            )
+        };
 
         fn get_function_signature<'ll, 'tcx>(
             cx: &CodegenCx<'ll, 'tcx>,
@@ -493,14 +514,16 @@ impl<'ll, 'tcx> DebugInfoMethods<'tcx> for CodegenCx<'ll, 'tcx> {
             names
         }
 
+        /// Returns a scope, plus `true` if that's a type scope for "class" methods,
+        /// otherwise `false` for plain namespace scopes.
         fn get_containing_scope<'ll, 'tcx>(
             cx: &CodegenCx<'ll, 'tcx>,
             instance: Instance<'tcx>,
-        ) -> &'ll DIScope {
+        ) -> (&'ll DIScope, bool) {
             // First, let's see if this is a method within an inherent impl. Because
             // if yes, we want to make the result subroutine DIE a child of the
             // subroutine's self-type.
-            let self_type = cx.tcx.impl_of_method(instance.def_id()).and_then(|impl_def_id| {
+            if let Some(impl_def_id) = cx.tcx.impl_of_method(instance.def_id()) {
                 // If the method does *not* belong to a trait, proceed
                 if cx.tcx.trait_id_of_impl(impl_def_id).is_none() {
                     let impl_self_ty = cx.tcx.subst_and_normalize_erasing_regions(
@@ -511,39 +534,33 @@ impl<'ll, 'tcx> DebugInfoMethods<'tcx> for CodegenCx<'ll, 'tcx> {
 
                     // Only "class" methods are generally understood by LLVM,
                     // so avoid methods on other types (e.g., `<*mut T>::null`).
-                    match impl_self_ty.kind() {
-                        ty::Adt(def, ..) if !def.is_box() => {
-                            // Again, only create type information if full debuginfo is enabled
-                            if cx.sess().opts.debuginfo == DebugInfo::Full
-                                && !impl_self_ty.has_param()
-                            {
-                                Some(type_di_node(cx, impl_self_ty))
-                            } else {
-                                Some(namespace::item_namespace(cx, def.did()))
-                            }
+                    if let ty::Adt(def, ..) = impl_self_ty.kind() && !def.is_box() {
+                        // Again, only create type information if full debuginfo is enabled
+                        if cx.sess().opts.debuginfo == DebugInfo::Full && !impl_self_ty.has_param()
+                        {
+                            return (type_di_node(cx, impl_self_ty), true);
+                        } else {
+                            return (namespace::item_namespace(cx, def.did()), false);
                         }
-                        _ => None,
                     }
                 } else {
                     // For trait method impls we still use the "parallel namespace"
                     // strategy
-                    None
                 }
-            });
+            }
 
-            self_type.unwrap_or_else(|| {
-                namespace::item_namespace(
-                    cx,
-                    DefId {
-                        krate: instance.def_id().krate,
-                        index: cx
-                            .tcx
-                            .def_key(instance.def_id())
-                            .parent
-                            .expect("get_containing_scope: missing parent?"),
-                    },
-                )
-            })
+            let scope = namespace::item_namespace(
+                cx,
+                DefId {
+                    krate: instance.def_id().krate,
+                    index: cx
+                        .tcx
+                        .def_key(instance.def_id())
+                        .parent
+                        .expect("get_containing_scope: missing parent?"),
+                },
+            );
+            (scope, false)
         }
     }
 
diff --git a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
index 53d97f35201..61365e6dc4b 100644
--- a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
+++ b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
@@ -1987,6 +1987,21 @@ extern "C" {
         Decl: Option<&'a DIDescriptor>,
     ) -> &'a DISubprogram;
 
+    pub fn LLVMRustDIBuilderCreateMethod<'a>(
+        Builder: &DIBuilder<'a>,
+        Scope: &'a DIDescriptor,
+        Name: *const c_char,
+        NameLen: size_t,
+        LinkageName: *const c_char,
+        LinkageNameLen: size_t,
+        File: &'a DIFile,
+        LineNo: c_uint,
+        Ty: &'a DIType,
+        Flags: DIFlags,
+        SPFlags: DISPFlags,
+        TParam: &'a DIArray,
+    ) -> &'a DISubprogram;
+
     pub fn LLVMRustDIBuilderCreateBasicType<'a>(
         Builder: &DIBuilder<'a>,
         Name: *const c_char,
diff --git a/compiler/rustc_codegen_ssa/src/back/write.rs b/compiler/rustc_codegen_ssa/src/back/write.rs
index c42d59bd51c..c323372bda4 100644
--- a/compiler/rustc_codegen_ssa/src/back/write.rs
+++ b/compiler/rustc_codegen_ssa/src/back/write.rs
@@ -1821,9 +1821,15 @@ impl SharedEmitterMain {
                         let source = sess
                             .source_map()
                             .new_source_file(FileName::inline_asm_source_code(&buffer), buffer);
-                        let source_span = Span::with_root_ctxt(source.start_pos, source.end_pos);
-                        let spans: Vec<_> =
-                            spans.iter().map(|sp| source_span.from_inner(*sp)).collect();
+                        let spans: Vec<_> = spans
+                            .iter()
+                            .map(|sp| {
+                                Span::with_root_ctxt(
+                                    source.normalized_byte_pos(sp.start as u32),
+                                    source.normalized_byte_pos(sp.end as u32),
+                                )
+                            })
+                            .collect();
                         err.span_note(spans, "instantiated into assembly here");
                     }
 
diff --git a/compiler/rustc_driver_impl/src/lib.rs b/compiler/rustc_driver_impl/src/lib.rs
index 2d529a34d8e..405f3d5b66d 100644
--- a/compiler/rustc_driver_impl/src/lib.rs
+++ b/compiler/rustc_driver_impl/src/lib.rs
@@ -25,7 +25,7 @@ use rustc_data_structures::profiling::{
 use rustc_data_structures::sync::SeqCst;
 use rustc_errors::registry::{InvalidErrorCode, Registry};
 use rustc_errors::{
-    DiagnosticMessage, ErrorGuaranteed, PResult, SubdiagnosticMessage, TerminalUrl,
+    DiagnosticMessage, ErrorGuaranteed, Handler, PResult, SubdiagnosticMessage, TerminalUrl,
 };
 use rustc_feature::find_gated_cfg;
 use rustc_fluent_macro::fluent_messages;
@@ -55,7 +55,7 @@ use std::panic::{self, catch_unwind};
 use std::path::PathBuf;
 use std::process::{self, Command, Stdio};
 use std::str;
-use std::sync::LazyLock;
+use std::sync::OnceLock;
 use std::time::Instant;
 
 // This import blocks the use of panicking `print` and `println` in all the code
@@ -119,7 +119,7 @@ pub const EXIT_SUCCESS: i32 = 0;
 /// Exit status code used for compilation failures and invalid flags.
 pub const EXIT_FAILURE: i32 = 1;
 
-const BUG_REPORT_URL: &str = "https://github.com/rust-lang/rust/issues/new\
+pub const DEFAULT_BUG_REPORT_URL: &str = "https://github.com/rust-lang/rust/issues/new\
     ?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md";
 
 const ICE_REPORT_COMPILER_FLAGS: &[&str] = &["-Z", "-C", "--crate-type"];
@@ -1196,35 +1196,58 @@ pub fn catch_with_exit_code(f: impl FnOnce() -> interface::Result<()>) -> i32 {
     }
 }
 
-static DEFAULT_HOOK: LazyLock<Box<dyn Fn(&panic::PanicInfo<'_>) + Sync + Send + 'static>> =
-    LazyLock::new(|| {
-        let hook = panic::take_hook();
-        panic::set_hook(Box::new(|info| {
-            // If the error was caused by a broken pipe then this is not a bug.
-            // Write the error and return immediately. See #98700.
-            #[cfg(windows)]
-            if let Some(msg) = info.payload().downcast_ref::<String>() {
-                if msg.starts_with("failed printing to stdout: ") && msg.ends_with("(os error 232)")
-                {
-                    early_error_no_abort(ErrorOutputType::default(), &msg);
-                    return;
-                }
-            };
+/// Stores the default panic hook, from before [`install_ice_hook`] was called.
+static DEFAULT_HOOK: OnceLock<Box<dyn Fn(&panic::PanicInfo<'_>) + Sync + Send + 'static>> =
+    OnceLock::new();
+
+/// Installs a panic hook that will print the ICE message on unexpected panics.
+///
+/// The hook is intended to be useable even by external tools. You can pass a custom
+/// `bug_report_url`, or report arbitrary info in `extra_info`. Note that `extra_info` is called in
+/// a context where *the thread is currently panicking*, so it must not panic or the process will
+/// abort.
+///
+/// If you have no extra info to report, pass the empty closure `|_| ()` as the argument to
+/// extra_info.
+///
+/// A custom rustc driver can skip calling this to set up a custom ICE hook.
+pub fn install_ice_hook(bug_report_url: &'static str, extra_info: fn(&Handler)) {
+    // If the user has not explicitly overridden "RUST_BACKTRACE", then produce
+    // full backtraces. When a compiler ICE happens, we want to gather
+    // as much information as possible to present in the issue opened
+    // by the user. Compiler developers and other rustc users can
+    // opt in to less-verbose backtraces by manually setting "RUST_BACKTRACE"
+    // (e.g. `RUST_BACKTRACE=1`)
+    if std::env::var("RUST_BACKTRACE").is_err() {
+        std::env::set_var("RUST_BACKTRACE", "full");
+    }
 
-            // Invoke the default handler, which prints the actual panic message and optionally a backtrace
-            // Don't do this for delayed bugs, which already emit their own more useful backtrace.
-            if !info.payload().is::<rustc_errors::DelayedBugPanic>() {
-                (*DEFAULT_HOOK)(info);
+    let default_hook = DEFAULT_HOOK.get_or_init(panic::take_hook);
 
-                // Separate the output with an empty line
-                eprintln!();
+    panic::set_hook(Box::new(move |info| {
+        // If the error was caused by a broken pipe then this is not a bug.
+        // Write the error and return immediately. See #98700.
+        #[cfg(windows)]
+        if let Some(msg) = info.payload().downcast_ref::<String>() {
+            if msg.starts_with("failed printing to stdout: ") && msg.ends_with("(os error 232)") {
+                early_error_no_abort(ErrorOutputType::default(), &msg);
+                return;
             }
+        };
 
-            // Print the ICE message
-            report_ice(info, BUG_REPORT_URL);
-        }));
-        hook
-    });
+        // Invoke the default handler, which prints the actual panic message and optionally a backtrace
+        // Don't do this for delayed bugs, which already emit their own more useful backtrace.
+        if !info.payload().is::<rustc_errors::DelayedBugPanic>() {
+            (*default_hook)(info);
+
+            // Separate the output with an empty line
+            eprintln!();
+        }
+
+        // Print the ICE message
+        report_ice(info, bug_report_url, extra_info);
+    }));
+}
 
 /// Prints the ICE message, including query stack, but without backtrace.
 ///
@@ -1232,7 +1255,7 @@ static DEFAULT_HOOK: LazyLock<Box<dyn Fn(&panic::PanicInfo<'_>) + Sync + Send +
 ///
 /// When `install_ice_hook` is called, this function will be called as the panic
 /// hook.
-pub fn report_ice(info: &panic::PanicInfo<'_>, bug_report_url: &str) {
+pub fn report_ice(info: &panic::PanicInfo<'_>, bug_report_url: &str, extra_info: fn(&Handler)) {
     let fallback_bundle =
         rustc_errors::fallback_fluent_bundle(crate::DEFAULT_LOCALE_RESOURCES.to_vec(), false);
     let emitter = Box::new(rustc_errors::emitter::EmitterWriter::stderr(
@@ -1277,6 +1300,10 @@ pub fn report_ice(info: &panic::PanicInfo<'_>, bug_report_url: &str) {
 
     interface::try_print_query_stack(&handler, num_frames);
 
+    // We don't trust this callback not to panic itself, so run it at the end after we're sure we've
+    // printed all the relevant info.
+    extra_info(&handler);
+
     #[cfg(windows)]
     if env::var("RUSTC_BREAK_ON_ICE").is_ok() {
         // Trigger a debugger if we crashed during bootstrap
@@ -1284,22 +1311,6 @@ pub fn report_ice(info: &panic::PanicInfo<'_>, bug_report_url: &str) {
     }
 }
 
-/// Installs a panic hook that will print the ICE message on unexpected panics.
-///
-/// A custom rustc driver can skip calling this to set up a custom ICE hook.
-pub fn install_ice_hook() {
-    // If the user has not explicitly overridden "RUST_BACKTRACE", then produce
-    // full backtraces. When a compiler ICE happens, we want to gather
-    // as much information as possible to present in the issue opened
-    // by the user. Compiler developers and other rustc users can
-    // opt in to less-verbose backtraces by manually setting "RUST_BACKTRACE"
-    // (e.g. `RUST_BACKTRACE=1`)
-    if std::env::var("RUST_BACKTRACE").is_err() {
-        std::env::set_var("RUST_BACKTRACE", "full");
-    }
-    LazyLock::force(&DEFAULT_HOOK);
-}
-
 /// This allows tools to enable rust logging without having to magically match rustc's
 /// tracing crate version.
 pub fn init_rustc_env_logger() {
@@ -1370,7 +1381,7 @@ pub fn main() -> ! {
     init_rustc_env_logger();
     signal_handler::install();
     let mut callbacks = TimePassesCallbacks::default();
-    install_ice_hook();
+    install_ice_hook(DEFAULT_BUG_REPORT_URL, |_| ());
     let exit_code = catch_with_exit_code(|| {
         let args = env::args_os()
             .enumerate()
diff --git a/compiler/rustc_hir_analysis/src/check/dropck.rs b/compiler/rustc_hir_analysis/src/check/dropck.rs
index bae80807f71..5ba1ca1c807 100644
--- a/compiler/rustc_hir_analysis/src/check/dropck.rs
+++ b/compiler/rustc_hir_analysis/src/check/dropck.rs
@@ -1,12 +1,14 @@
 // FIXME(@lcnr): Move this module out of `rustc_hir_analysis`.
 //
 // We don't do any drop checking during hir typeck.
+use rustc_data_structures::fx::FxHashSet;
 use rustc_errors::{struct_span_err, ErrorGuaranteed};
-use rustc_middle::ty::error::TypeError;
-use rustc_middle::ty::relate::{Relate, RelateResult, TypeRelation};
+use rustc_infer::infer::outlives::env::OutlivesEnvironment;
+use rustc_infer::infer::{RegionResolutionError, TyCtxtInferExt};
 use rustc_middle::ty::subst::SubstsRef;
 use rustc_middle::ty::util::IgnoreRegions;
-use rustc_middle::ty::{self, Predicate, Ty, TyCtxt};
+use rustc_middle::ty::{self, TyCtxt};
+use rustc_trait_selection::traits::{self, ObligationCtxt};
 
 use crate::errors;
 use crate::hir::def_id::{DefId, LocalDefId};
@@ -43,21 +45,20 @@ pub fn check_drop_impl(tcx: TyCtxt<'_>, drop_impl_did: DefId) -> Result<(), Erro
         }
     }
     let dtor_self_type = tcx.type_of(drop_impl_did).subst_identity();
-    let dtor_predicates = tcx.predicates_of(drop_impl_did);
     match dtor_self_type.kind() {
-        ty::Adt(adt_def, self_to_impl_substs) => {
+        ty::Adt(adt_def, adt_to_impl_substs) => {
             ensure_drop_params_and_item_params_correspond(
                 tcx,
                 drop_impl_did.expect_local(),
                 adt_def.did(),
-                self_to_impl_substs,
+                adt_to_impl_substs,
             )?;
 
             ensure_drop_predicates_are_implied_by_item_defn(
                 tcx,
-                dtor_predicates,
+                drop_impl_did.expect_local(),
                 adt_def.did().expect_local(),
-                self_to_impl_substs,
+                adt_to_impl_substs,
             )
         }
         _ => {
@@ -78,9 +79,9 @@ fn ensure_drop_params_and_item_params_correspond<'tcx>(
     tcx: TyCtxt<'tcx>,
     drop_impl_did: LocalDefId,
     self_type_did: DefId,
-    drop_impl_substs: SubstsRef<'tcx>,
+    adt_to_impl_substs: SubstsRef<'tcx>,
 ) -> Result<(), ErrorGuaranteed> {
-    let Err(arg) = tcx.uses_unique_generic_params(drop_impl_substs, IgnoreRegions::No) else {
+    let Err(arg) = tcx.uses_unique_generic_params(adt_to_impl_substs, IgnoreRegions::No) else {
         return Ok(())
     };
 
@@ -111,237 +112,94 @@ fn ensure_drop_params_and_item_params_correspond<'tcx>(
 /// implied by assuming the predicates attached to self_type_did.
 fn ensure_drop_predicates_are_implied_by_item_defn<'tcx>(
     tcx: TyCtxt<'tcx>,
-    dtor_predicates: ty::GenericPredicates<'tcx>,
-    self_type_did: LocalDefId,
-    self_to_impl_substs: SubstsRef<'tcx>,
+    drop_impl_def_id: LocalDefId,
+    adt_def_id: LocalDefId,
+    adt_to_impl_substs: SubstsRef<'tcx>,
 ) -> Result<(), ErrorGuaranteed> {
-    let mut result = Ok(());
-
-    // Here is an example, analogous to that from
-    // `compare_impl_method`.
-    //
-    // Consider a struct type:
-    //
-    //     struct Type<'c, 'b:'c, 'a> {
-    //         x: &'a Contents            // (contents are irrelevant;
-    //         y: &'c Cell<&'b Contents>, //  only the bounds matter for our purposes.)
-    //     }
-    //
-    // and a Drop impl:
-    //
-    //     impl<'z, 'y:'z, 'x:'y> Drop for P<'z, 'y, 'x> {
-    //         fn drop(&mut self) { self.y.set(self.x); } // (only legal if 'x: 'y)
-    //     }
-    //
-    // We start out with self_to_impl_substs, that maps the generic
-    // parameters of Type to that of the Drop impl.
+    let infcx = tcx.infer_ctxt().build();
+    let ocx = ObligationCtxt::new(&infcx);
+
+    // Take the param-env of the adt and substitute the substs that show up in
+    // the implementation's self type. This gives us the assumptions that the
+    // self ty of the implementation is allowed to know just from it being a
+    // well-formed adt, since that's all we're allowed to assume while proving
+    // the Drop implementation is not specialized.
     //
-    //     self_to_impl_substs = {'c => 'z, 'b => 'y, 'a => 'x}
-    //
-    // Applying this to the predicates (i.e., assumptions) provided by the item
-    // definition yields the instantiated assumptions:
-    //
-    //     ['y : 'z]
-    //
-    // We then check all of the predicates of the Drop impl:
-    //
-    //     ['y:'z, 'x:'y]
-    //
-    // and ensure each is in the list of instantiated
-    // assumptions. Here, `'y:'z` is present, but `'x:'y` is
-    // absent. So we report an error that the Drop impl injected a
-    // predicate that is not present on the struct definition.
-
-    // We can assume the predicates attached to struct/enum definition
-    // hold.
-    let generic_assumptions = tcx.predicates_of(self_type_did);
-
-    let assumptions_in_impl_context = generic_assumptions.instantiate(tcx, &self_to_impl_substs);
-    let assumptions_in_impl_context = assumptions_in_impl_context.predicates;
-
-    debug!(?assumptions_in_impl_context, ?dtor_predicates.predicates);
-
-    let self_param_env = tcx.param_env(self_type_did);
-
-    // An earlier version of this code attempted to do this checking
-    // via the traits::fulfill machinery. However, it ran into trouble
-    // since the fulfill machinery merely turns outlives-predicates
-    // 'a:'b and T:'b into region inference constraints. It is simpler
-    // just to look for all the predicates directly.
-
-    assert_eq!(dtor_predicates.parent, None);
-    for &(predicate, predicate_sp) in dtor_predicates.predicates {
-        // (We do not need to worry about deep analysis of type
-        // expressions etc because the Drop impls are already forced
-        // to take on a structure that is roughly an alpha-renaming of
-        // the generic parameters of the item definition.)
-
-        // This path now just checks *all* predicates via an instantiation of
-        // the `SimpleEqRelation`, which simply forwards to the `relate` machinery
-        // after taking care of anonymizing late bound regions.
-        //
-        // However, it may be more efficient in the future to batch
-        // the analysis together via the fulfill (see comment above regarding
-        // the usage of the fulfill machinery), rather than the
-        // repeated `.iter().any(..)` calls.
+    // We don't need to normalize this param-env or anything, since we're only
+    // substituting it with free params, so no additional param-env normalization
+    // can occur on top of what has been done in the param_env query itself.
+    let param_env = ty::EarlyBinder(tcx.param_env(adt_def_id))
+        .subst(tcx, adt_to_impl_substs)
+        .with_constness(tcx.constness(drop_impl_def_id));
+
+    for (pred, span) in tcx.predicates_of(drop_impl_def_id).instantiate_identity(tcx) {
+        let normalize_cause = traits::ObligationCause::misc(span, adt_def_id);
+        let pred = ocx.normalize(&normalize_cause, param_env, pred);
+        let cause = traits::ObligationCause::new(span, adt_def_id, traits::DropImpl);
+        ocx.register_obligation(traits::Obligation::new(tcx, cause, param_env, pred));
+    }
 
-        // This closure is a more robust way to check `Predicate` equality
-        // than simple `==` checks (which were the previous implementation).
-        // It relies on `ty::relate` for `TraitPredicate`, `ProjectionPredicate`,
-        // `ConstEvaluatable` and `TypeOutlives` (which implement the Relate trait),
-        // while delegating on simple equality for the other `Predicate`.
-        // This implementation solves (Issue #59497) and (Issue #58311).
-        // It is unclear to me at the moment whether the approach based on `relate`
-        // could be extended easily also to the other `Predicate`.
-        let predicate_matches_closure = |p: Predicate<'tcx>| {
-            let mut relator: SimpleEqRelation<'tcx> = SimpleEqRelation::new(tcx, self_param_env);
-            let predicate = predicate.kind();
-            let p = p.kind();
-            match (predicate.skip_binder(), p.skip_binder()) {
-                (
-                    ty::PredicateKind::Clause(ty::Clause::Trait(a)),
-                    ty::PredicateKind::Clause(ty::Clause::Trait(b)),
-                ) => relator.relate(predicate.rebind(a), p.rebind(b)).is_ok(),
-                (
-                    ty::PredicateKind::Clause(ty::Clause::Projection(a)),
-                    ty::PredicateKind::Clause(ty::Clause::Projection(b)),
-                ) => relator.relate(predicate.rebind(a), p.rebind(b)).is_ok(),
-                (
-                    ty::PredicateKind::ConstEvaluatable(a),
-                    ty::PredicateKind::ConstEvaluatable(b),
-                ) => relator.relate(predicate.rebind(a), predicate.rebind(b)).is_ok(),
-                (
-                    ty::PredicateKind::Clause(ty::Clause::TypeOutlives(ty::OutlivesPredicate(
-                        ty_a,
-                        lt_a,
-                    ))),
-                    ty::PredicateKind::Clause(ty::Clause::TypeOutlives(ty::OutlivesPredicate(
-                        ty_b,
-                        lt_b,
-                    ))),
-                ) => {
-                    relator.relate(predicate.rebind(ty_a), p.rebind(ty_b)).is_ok()
-                        && relator.relate(predicate.rebind(lt_a), p.rebind(lt_b)).is_ok()
-                }
-                (ty::PredicateKind::WellFormed(arg_a), ty::PredicateKind::WellFormed(arg_b)) => {
-                    relator.relate(predicate.rebind(arg_a), p.rebind(arg_b)).is_ok()
-                }
-                _ => predicate == p,
+    // All of the custom error reporting logic is to preserve parity with the old
+    // error messages.
+    //
+    // They can probably get removed with better treatment of the new `DropImpl`
+    // obligation cause code, and perhaps some custom logic in `report_region_errors`.
+
+    let errors = ocx.select_all_or_error();
+    if !errors.is_empty() {
+        let mut guar = None;
+        let mut root_predicates = FxHashSet::default();
+        for error in errors {
+            let root_predicate = error.root_obligation.predicate;
+            if root_predicates.insert(root_predicate) {
+                let item_span = tcx.def_span(adt_def_id);
+                let self_descr = tcx.def_descr(adt_def_id.to_def_id());
+                guar = Some(
+                    struct_span_err!(
+                        tcx.sess,
+                        error.root_obligation.cause.span,
+                        E0367,
+                        "`Drop` impl requires `{root_predicate}` \
+                        but the {self_descr} it is implemented for does not",
+                    )
+                    .span_note(item_span, "the implementor must specify the same requirement")
+                    .emit(),
+                );
             }
-        };
-
-        if !assumptions_in_impl_context.iter().copied().any(predicate_matches_closure) {
-            let item_span = tcx.def_span(self_type_did);
-            let self_descr = tcx.def_descr(self_type_did.to_def_id());
-            let reported = struct_span_err!(
-                tcx.sess,
-                predicate_sp,
-                E0367,
-                "`Drop` impl requires `{predicate}` but the {self_descr} it is implemented for does not",
-            )
-            .span_note(item_span, "the implementor must specify the same requirement")
-            .emit();
-            result = Err(reported);
         }
+        return Err(guar.unwrap());
     }
 
-    result
-}
-
-/// This is an implementation of the [`TypeRelation`] trait with the
-/// aim of simply comparing for equality (without side-effects).
-///
-/// It is not intended to be used anywhere else other than here.
-pub(crate) struct SimpleEqRelation<'tcx> {
-    tcx: TyCtxt<'tcx>,
-    param_env: ty::ParamEnv<'tcx>,
-}
-
-impl<'tcx> SimpleEqRelation<'tcx> {
-    fn new(tcx: TyCtxt<'tcx>, param_env: ty::ParamEnv<'tcx>) -> SimpleEqRelation<'tcx> {
-        SimpleEqRelation { tcx, param_env }
-    }
-}
-
-impl<'tcx> TypeRelation<'tcx> for SimpleEqRelation<'tcx> {
-    fn tcx(&self) -> TyCtxt<'tcx> {
-        self.tcx
-    }
-
-    fn param_env(&self) -> ty::ParamEnv<'tcx> {
-        self.param_env
-    }
-
-    fn tag(&self) -> &'static str {
-        "dropck::SimpleEqRelation"
-    }
-
-    fn a_is_expected(&self) -> bool {
-        true
-    }
-
-    fn relate_with_variance<T: Relate<'tcx>>(
-        &mut self,
-        _: ty::Variance,
-        _info: ty::VarianceDiagInfo<'tcx>,
-        a: T,
-        b: T,
-    ) -> RelateResult<'tcx, T> {
-        // Here we ignore variance because we require drop impl's types
-        // to be *exactly* the same as to the ones in the struct definition.
-        self.relate(a, b)
-    }
-
-    fn tys(&mut self, a: Ty<'tcx>, b: Ty<'tcx>) -> RelateResult<'tcx, Ty<'tcx>> {
-        debug!("SimpleEqRelation::tys(a={:?}, b={:?})", a, b);
-        ty::relate::super_relate_tys(self, a, b)
-    }
-
-    fn regions(
-        &mut self,
-        a: ty::Region<'tcx>,
-        b: ty::Region<'tcx>,
-    ) -> RelateResult<'tcx, ty::Region<'tcx>> {
-        debug!("SimpleEqRelation::regions(a={:?}, b={:?})", a, b);
-
-        // We can just equate the regions because LBRs have been
-        // already anonymized.
-        if a == b {
-            Ok(a)
-        } else {
-            // I'm not sure is this `TypeError` is the right one, but
-            // it should not matter as it won't be checked (the dropck
-            // will emit its own, more informative and higher-level errors
-            // in case anything goes wrong).
-            Err(TypeError::RegionsPlaceholderMismatch)
+    let errors = ocx.infcx.resolve_regions(&OutlivesEnvironment::new(param_env));
+    if !errors.is_empty() {
+        let mut guar = None;
+        for error in errors {
+            let item_span = tcx.def_span(adt_def_id);
+            let self_descr = tcx.def_descr(adt_def_id.to_def_id());
+            let outlives = match error {
+                RegionResolutionError::ConcreteFailure(_, a, b) => format!("{b}: {a}"),
+                RegionResolutionError::GenericBoundFailure(_, generic, r) => {
+                    format!("{generic}: {r}")
+                }
+                RegionResolutionError::SubSupConflict(_, _, _, a, _, b, _) => format!("{b}: {a}"),
+                RegionResolutionError::UpperBoundUniverseConflict(a, _, _, _, b) => {
+                    format!("{b}: {a}", a = tcx.mk_re_var(a))
+                }
+            };
+            guar = Some(
+                struct_span_err!(
+                    tcx.sess,
+                    error.origin().span(),
+                    E0367,
+                    "`Drop` impl requires `{outlives}` \
+                    but the {self_descr} it is implemented for does not",
+                )
+                .span_note(item_span, "the implementor must specify the same requirement")
+                .emit(),
+            );
         }
+        return Err(guar.unwrap());
     }
 
-    fn consts(
-        &mut self,
-        a: ty::Const<'tcx>,
-        b: ty::Const<'tcx>,
-    ) -> RelateResult<'tcx, ty::Const<'tcx>> {
-        debug!("SimpleEqRelation::consts(a={:?}, b={:?})", a, b);
-        ty::relate::super_relate_consts(self, a, b)
-    }
-
-    fn binders<T>(
-        &mut self,
-        a: ty::Binder<'tcx, T>,
-        b: ty::Binder<'tcx, T>,
-    ) -> RelateResult<'tcx, ty::Binder<'tcx, T>>
-    where
-        T: Relate<'tcx>,
-    {
-        debug!("SimpleEqRelation::binders({:?}: {:?}", a, b);
-
-        // Anonymizing the LBRs is necessary to solve (Issue #59497).
-        // After we do so, it should be totally fine to skip the binders.
-        let anon_a = self.tcx.anonymize_bound_vars(a);
-        let anon_b = self.tcx.anonymize_bound_vars(b);
-        self.relate(anon_a.skip_binder(), anon_b.skip_binder())?;
-
-        Ok(a)
-    }
+    Ok(())
 }
diff --git a/compiler/rustc_infer/src/infer/lexical_region_resolve/mod.rs b/compiler/rustc_infer/src/infer/lexical_region_resolve/mod.rs
index f1468cae455..8482ae2aa38 100644
--- a/compiler/rustc_infer/src/infer/lexical_region_resolve/mod.rs
+++ b/compiler/rustc_infer/src/infer/lexical_region_resolve/mod.rs
@@ -102,6 +102,17 @@ pub enum RegionResolutionError<'tcx> {
     ),
 }
 
+impl<'tcx> RegionResolutionError<'tcx> {
+    pub fn origin(&self) -> &SubregionOrigin<'tcx> {
+        match self {
+            RegionResolutionError::ConcreteFailure(origin, _, _)
+            | RegionResolutionError::GenericBoundFailure(origin, _, _)
+            | RegionResolutionError::SubSupConflict(_, _, origin, _, _, _, _)
+            | RegionResolutionError::UpperBoundUniverseConflict(_, _, _, origin, _) => origin,
+        }
+    }
+}
+
 struct RegionAndOrigin<'tcx> {
     region: Region<'tcx>,
     origin: SubregionOrigin<'tcx>,
diff --git a/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp b/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp
index cadb6b1e23f..49acd71b3e1 100644
--- a/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp
+++ b/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp
@@ -831,6 +831,28 @@ extern "C" LLVMMetadataRef LLVMRustDIBuilderCreateFunction(
   return wrap(Sub);
 }
 
+extern "C" LLVMMetadataRef LLVMRustDIBuilderCreateMethod(
+    LLVMRustDIBuilderRef Builder, LLVMMetadataRef Scope,
+    const char *Name, size_t NameLen,
+    const char *LinkageName, size_t LinkageNameLen,
+    LLVMMetadataRef File, unsigned LineNo,
+    LLVMMetadataRef Ty, LLVMRustDIFlags Flags,
+    LLVMRustDISPFlags SPFlags, LLVMMetadataRef TParam) {
+  DITemplateParameterArray TParams =
+      DITemplateParameterArray(unwrap<MDTuple>(TParam));
+  DISubprogram::DISPFlags llvmSPFlags = fromRust(SPFlags);
+  DINode::DIFlags llvmFlags = fromRust(Flags);
+  DISubprogram *Sub = Builder->createMethod(
+      unwrapDI<DIScope>(Scope),
+      StringRef(Name, NameLen),
+      StringRef(LinkageName, LinkageNameLen),
+      unwrapDI<DIFile>(File), LineNo,
+      unwrapDI<DISubroutineType>(Ty),
+      0, 0, nullptr, // VTable params aren't used
+      llvmFlags, llvmSPFlags, TParams);
+  return wrap(Sub);
+}
+
 extern "C" LLVMMetadataRef LLVMRustDIBuilderCreateBasicType(
     LLVMRustDIBuilderRef Builder, const char *Name, size_t NameLen,
     uint64_t SizeInBits, unsigned Encoding) {
diff --git a/compiler/rustc_middle/src/traits/mod.rs b/compiler/rustc_middle/src/traits/mod.rs
index c2375564208..8366567c2c3 100644
--- a/compiler/rustc_middle/src/traits/mod.rs
+++ b/compiler/rustc_middle/src/traits/mod.rs
@@ -444,6 +444,10 @@ pub enum ObligationCauseCode<'tcx> {
     AscribeUserTypeProvePredicate(Span),
 
     RustCall,
+
+    /// Obligations to prove that a `std::ops::Drop` impl is not stronger than
+    /// the ADT it's being implemented for.
+    DropImpl,
 }
 
 /// The 'location' at which we try to perform HIR-based wf checking.
diff --git a/compiler/rustc_middle/src/ty/instance.rs b/compiler/rustc_middle/src/ty/instance.rs
index cc86cba6fda..6c8f4af7594 100644
--- a/compiler/rustc_middle/src/ty/instance.rs
+++ b/compiler/rustc_middle/src/ty/instance.rs
@@ -385,7 +385,7 @@ impl<'tcx> Instance<'tcx> {
     /// couldn't complete due to errors elsewhere - this is distinct
     /// from `Ok(None)` to avoid misleading diagnostics when an error
     /// has already been/will be emitted, for the original cause
-    #[instrument(level = "debug", skip(tcx))]
+    #[instrument(level = "debug", skip(tcx), ret)]
     pub fn resolve(
         tcx: TyCtxt<'tcx>,
         param_env: ty::ParamEnv<'tcx>,
diff --git a/compiler/rustc_parse/src/parser/expr.rs b/compiler/rustc_parse/src/parser/expr.rs
index 61396ee0d4a..018eddea4b0 100644
--- a/compiler/rustc_parse/src/parser/expr.rs
+++ b/compiler/rustc_parse/src/parser/expr.rs
@@ -1448,8 +1448,19 @@ impl<'a> Parser<'a> {
     }
 
     fn parse_expr_path_start(&mut self) -> PResult<'a, P<Expr>> {
+        let maybe_eq_tok = self.prev_token.clone();
         let (qself, path) = if self.eat_lt() {
-            let (qself, path) = self.parse_qpath(PathStyle::Expr)?;
+            let lt_span = self.prev_token.span;
+            let (qself, path) = self.parse_qpath(PathStyle::Expr).map_err(|mut err| {
+                // Suggests using '<=' if there is an error parsing qpath when the previous token
+                // is an '=' token. Only emits suggestion if the '<' token and '=' token are
+                // directly adjacent (i.e. '=<')
+                if maybe_eq_tok.kind == TokenKind::Eq && maybe_eq_tok.span.hi() == lt_span.lo() {
+                    let eq_lt = maybe_eq_tok.span.to(lt_span);
+                    err.span_suggestion(eq_lt, "did you mean", "<=", Applicability::Unspecified);
+                }
+                err
+            })?;
             (Some(qself), path)
         } else {
             (None, self.parse_path(PathStyle::Expr)?)
diff --git a/compiler/rustc_smir/Cargo.toml b/compiler/rustc_smir/Cargo.toml
index fb97ee5bebe..80360a3c73f 100644
--- a/compiler/rustc_smir/Cargo.toml
+++ b/compiler/rustc_smir/Cargo.toml
@@ -4,6 +4,7 @@ version = "0.0.0"
 edition = "2021"
 
 [dependencies]
+rustc_hir = { path = "../rustc_hir" }
 rustc_middle = { path = "../rustc_middle", optional = true }
 rustc_span = { path = "../rustc_span", optional = true }
 tracing = "0.1"
diff --git a/compiler/rustc_smir/src/rustc_smir/mod.rs b/compiler/rustc_smir/src/rustc_smir/mod.rs
index 09cb6fd22d5..241cd182059 100644
--- a/compiler/rustc_smir/src/rustc_smir/mod.rs
+++ b/compiler/rustc_smir/src/rustc_smir/mod.rs
@@ -93,10 +93,10 @@ fn rustc_statement_to_statement(
     }
 }
 
-fn rustc_rvalue_to_rvalue(rvalue: &rustc_middle::mir::Rvalue<'_>) -> stable_mir::mir::Operand {
+fn rustc_rvalue_to_rvalue(rvalue: &rustc_middle::mir::Rvalue<'_>) -> stable_mir::mir::Rvalue {
     use rustc_middle::mir::Rvalue::*;
     match rvalue {
-        Use(op) => rustc_op_to_op(op),
+        Use(op) => stable_mir::mir::Rvalue::Use(rustc_op_to_op(op)),
         Repeat(_, _) => todo!(),
         Ref(_, _, _) => todo!(),
         ThreadLocalRef(_) => todo!(),
@@ -104,9 +104,15 @@ fn rustc_rvalue_to_rvalue(rvalue: &rustc_middle::mir::Rvalue<'_>) -> stable_mir:
         Len(_) => todo!(),
         Cast(_, _, _) => todo!(),
         BinaryOp(_, _) => todo!(),
-        CheckedBinaryOp(_, _) => todo!(),
+        CheckedBinaryOp(bin_op, ops) => stable_mir::mir::Rvalue::CheckedBinaryOp(
+            rustc_bin_op_to_bin_op(bin_op),
+            rustc_op_to_op(&ops.0),
+            rustc_op_to_op(&ops.1),
+        ),
         NullaryOp(_, _) => todo!(),
-        UnaryOp(_, _) => todo!(),
+        UnaryOp(un_op, op) => {
+            stable_mir::mir::Rvalue::UnaryOp(rustc_un_op_to_un_op(un_op), rustc_op_to_op(op))
+        }
         Discriminant(_) => todo!(),
         Aggregate(_, _) => todo!(),
         ShallowInitBox(_, _) => todo!(),
@@ -124,8 +130,10 @@ fn rustc_op_to_op(op: &rustc_middle::mir::Operand<'_>) -> stable_mir::mir::Opera
 }
 
 fn rustc_place_to_place(place: &rustc_middle::mir::Place<'_>) -> stable_mir::mir::Place {
-    assert_eq!(&place.projection[..], &[]);
-    stable_mir::mir::Place { local: place.local.as_usize() }
+    stable_mir::mir::Place {
+        local: place.local.as_usize(),
+        projection: format!("{:?}", place.projection),
+    }
 }
 
 fn rustc_unwind_to_unwind(
@@ -140,6 +148,96 @@ fn rustc_unwind_to_unwind(
     }
 }
 
+fn rustc_assert_msg_to_msg<'tcx>(
+    assert_message: &rustc_middle::mir::AssertMessage<'tcx>,
+) -> stable_mir::mir::AssertMessage {
+    use rustc_middle::mir::AssertKind;
+    match assert_message {
+        AssertKind::BoundsCheck { len, index } => stable_mir::mir::AssertMessage::BoundsCheck {
+            len: rustc_op_to_op(len),
+            index: rustc_op_to_op(index),
+        },
+        AssertKind::Overflow(bin_op, op1, op2) => stable_mir::mir::AssertMessage::Overflow(
+            rustc_bin_op_to_bin_op(bin_op),
+            rustc_op_to_op(op1),
+            rustc_op_to_op(op2),
+        ),
+        AssertKind::OverflowNeg(op) => {
+            stable_mir::mir::AssertMessage::OverflowNeg(rustc_op_to_op(op))
+        }
+        AssertKind::DivisionByZero(op) => {
+            stable_mir::mir::AssertMessage::DivisionByZero(rustc_op_to_op(op))
+        }
+        AssertKind::RemainderByZero(op) => {
+            stable_mir::mir::AssertMessage::RemainderByZero(rustc_op_to_op(op))
+        }
+        AssertKind::ResumedAfterReturn(generator) => {
+            stable_mir::mir::AssertMessage::ResumedAfterReturn(rustc_generator_to_generator(
+                generator,
+            ))
+        }
+        AssertKind::ResumedAfterPanic(generator) => {
+            stable_mir::mir::AssertMessage::ResumedAfterPanic(rustc_generator_to_generator(
+                generator,
+            ))
+        }
+        AssertKind::MisalignedPointerDereference { required, found } => {
+            stable_mir::mir::AssertMessage::MisalignedPointerDereference {
+                required: rustc_op_to_op(required),
+                found: rustc_op_to_op(found),
+            }
+        }
+    }
+}
+
+fn rustc_bin_op_to_bin_op(bin_op: &rustc_middle::mir::BinOp) -> stable_mir::mir::BinOp {
+    use rustc_middle::mir::BinOp;
+    match bin_op {
+        BinOp::Add => stable_mir::mir::BinOp::Add,
+        BinOp::Sub => stable_mir::mir::BinOp::Sub,
+        BinOp::Mul => stable_mir::mir::BinOp::Mul,
+        BinOp::Div => stable_mir::mir::BinOp::Div,
+        BinOp::Rem => stable_mir::mir::BinOp::Rem,
+        BinOp::BitXor => stable_mir::mir::BinOp::BitXor,
+        BinOp::BitAnd => stable_mir::mir::BinOp::BitAnd,
+        BinOp::BitOr => stable_mir::mir::BinOp::BitOr,
+        BinOp::Shl => stable_mir::mir::BinOp::Shl,
+        BinOp::Shr => stable_mir::mir::BinOp::Shr,
+        BinOp::Eq => stable_mir::mir::BinOp::Eq,
+        BinOp::Lt => stable_mir::mir::BinOp::Lt,
+        BinOp::Le => stable_mir::mir::BinOp::Le,
+        BinOp::Ne => stable_mir::mir::BinOp::Ne,
+        BinOp::Ge => stable_mir::mir::BinOp::Ge,
+        BinOp::Gt => stable_mir::mir::BinOp::Gt,
+        BinOp::Offset => stable_mir::mir::BinOp::Offset,
+    }
+}
+
+fn rustc_un_op_to_un_op(unary_op: &rustc_middle::mir::UnOp) -> stable_mir::mir::UnOp {
+    use rustc_middle::mir::UnOp;
+    match unary_op {
+        UnOp::Not => stable_mir::mir::UnOp::Not,
+        UnOp::Neg => stable_mir::mir::UnOp::Neg,
+    }
+}
+
+fn rustc_generator_to_generator(
+    generator: &rustc_hir::GeneratorKind,
+) -> stable_mir::mir::GeneratorKind {
+    use rustc_hir::{AsyncGeneratorKind, GeneratorKind};
+    match generator {
+        GeneratorKind::Async(async_gen) => {
+            let async_gen = match async_gen {
+                AsyncGeneratorKind::Block => stable_mir::mir::AsyncGeneratorKind::Block,
+                AsyncGeneratorKind::Closure => stable_mir::mir::AsyncGeneratorKind::Closure,
+                AsyncGeneratorKind::Fn => stable_mir::mir::AsyncGeneratorKind::Fn,
+            };
+            stable_mir::mir::GeneratorKind::Async(async_gen)
+        }
+        GeneratorKind::Gen => stable_mir::mir::GeneratorKind::Gen,
+    }
+}
+
 fn rustc_terminator_to_terminator(
     terminator: &rustc_middle::mir::Terminator<'_>,
 ) -> stable_mir::mir::Terminator {
@@ -162,7 +260,11 @@ fn rustc_terminator_to_terminator(
         Terminate => Terminator::Abort,
         Return => Terminator::Return,
         Unreachable => Terminator::Unreachable,
-        Drop { .. } => todo!(),
+        Drop { place, target, unwind } => Terminator::Drop {
+            place: rustc_place_to_place(place),
+            target: target.as_usize(),
+            unwind: rustc_unwind_to_unwind(unwind),
+        },
         Call { func, args, destination, target, unwind, from_hir_call: _, fn_span: _ } => {
             Terminator::Call {
                 func: rustc_op_to_op(func),
@@ -172,9 +274,15 @@ fn rustc_terminator_to_terminator(
                 unwind: rustc_unwind_to_unwind(unwind),
             }
         }
-        Assert { .. } => todo!(),
+        Assert { cond, expected, msg, target, unwind } => Terminator::Assert {
+            cond: rustc_op_to_op(cond),
+            expected: *expected,
+            msg: rustc_assert_msg_to_msg(msg),
+            target: target.as_usize(),
+            unwind: rustc_unwind_to_unwind(unwind),
+        },
         Yield { .. } => todo!(),
-        GeneratorDrop => todo!(),
+        GeneratorDrop => Terminator::GeneratorDrop,
         FalseEdge { .. } => todo!(),
         FalseUnwind { .. } => todo!(),
         InlineAsm { .. } => todo!(),
diff --git a/compiler/rustc_smir/src/stable_mir/mir/body.rs b/compiler/rustc_smir/src/stable_mir/mir/body.rs
index bd5e6b68a12..4baf3f1f75e 100644
--- a/compiler/rustc_smir/src/stable_mir/mir/body.rs
+++ b/compiler/rustc_smir/src/stable_mir/mir/body.rs
@@ -26,7 +26,7 @@ pub enum Terminator {
     Drop {
         place: Place,
         target: usize,
-        unwind: Option<usize>,
+        unwind: UnwindAction,
     },
     Call {
         func: Operand,
@@ -38,10 +38,11 @@ pub enum Terminator {
     Assert {
         cond: Operand,
         expected: bool,
-        msg: String,
+        msg: AssertMessage,
         target: usize,
-        cleanup: Option<usize>,
+        unwind: UnwindAction,
     },
+    GeneratorDrop,
 }
 
 #[derive(Clone, Debug)]
@@ -53,11 +54,71 @@ pub enum UnwindAction {
 }
 
 #[derive(Clone, Debug)]
+pub enum AssertMessage {
+    BoundsCheck { len: Operand, index: Operand },
+    Overflow(BinOp, Operand, Operand),
+    OverflowNeg(Operand),
+    DivisionByZero(Operand),
+    RemainderByZero(Operand),
+    ResumedAfterReturn(GeneratorKind),
+    ResumedAfterPanic(GeneratorKind),
+    MisalignedPointerDereference { required: Operand, found: Operand },
+}
+
+#[derive(Clone, Debug)]
+pub enum BinOp {
+    Add,
+    Sub,
+    Mul,
+    Div,
+    Rem,
+    BitXor,
+    BitAnd,
+    BitOr,
+    Shl,
+    Shr,
+    Eq,
+    Lt,
+    Le,
+    Ne,
+    Ge,
+    Gt,
+    Offset,
+}
+
+#[derive(Clone, Debug)]
+pub enum UnOp {
+    Not,
+    Neg,
+}
+
+#[derive(Clone, Debug)]
+pub enum GeneratorKind {
+    Async(AsyncGeneratorKind),
+    Gen,
+}
+
+#[derive(Clone, Debug)]
+pub enum AsyncGeneratorKind {
+    Block,
+    Closure,
+    Fn,
+}
+
+#[derive(Clone, Debug)]
 pub enum Statement {
-    Assign(Place, Operand),
+    Assign(Place, Rvalue),
     Nop,
 }
 
+// FIXME this is incomplete
+#[derive(Clone, Debug)]
+pub enum Rvalue {
+    Use(Operand),
+    CheckedBinaryOp(BinOp, Operand, Operand),
+    UnaryOp(UnOp, Operand),
+}
+
 #[derive(Clone, Debug)]
 pub enum Operand {
     Copy(Place),
@@ -68,6 +129,7 @@ pub enum Operand {
 #[derive(Clone, Debug)]
 pub struct Place {
     pub local: usize,
+    pub projection: String,
 }
 
 #[derive(Clone, Debug)]
diff --git a/compiler/rustc_span/src/lib.rs b/compiler/rustc_span/src/lib.rs
index 5654a3979a0..7bbab34c69a 100644
--- a/compiler/rustc_span/src/lib.rs
+++ b/compiler/rustc_span/src/lib.rs
@@ -1744,6 +1744,28 @@ impl SourceFile {
         BytePos::from_u32(pos.0 - self.start_pos.0 + diff)
     }
 
+    /// Calculates a normalized byte position from a byte offset relative to the
+    /// start of the file.
+    ///
+    /// When we get an inline assembler error from LLVM during codegen, we
+    /// import the expanded assembly code as a new `SourceFile`, which can then
+    /// be used for error reporting with spans. However the byte offsets given
+    /// to us by LLVM are relative to the start of the original buffer, not the
+    /// normalized one. Hence we need to convert those offsets to the normalized
+    /// form when constructing spans.
+    pub fn normalized_byte_pos(&self, offset: u32) -> BytePos {
+        let diff = match self
+            .normalized_pos
+            .binary_search_by(|np| (np.pos.0 + np.diff).cmp(&(self.start_pos.0 + offset)))
+        {
+            Ok(i) => self.normalized_pos[i].diff,
+            Err(i) if i == 0 => 0,
+            Err(i) => self.normalized_pos[i - 1].diff,
+        };
+
+        BytePos::from_u32(self.start_pos.0 + offset - diff)
+    }
+
     /// Converts an absolute `BytePos` to a `CharPos` relative to the `SourceFile`.
     pub fn bytepos_to_file_charpos(&self, bpos: BytePos) -> CharPos {
         // The number of extra bytes due to multibyte chars in the `SourceFile`.
diff --git a/compiler/rustc_span/src/symbol.rs b/compiler/rustc_span/src/symbol.rs
index 58015d5d502..b97ec6c684b 100644
--- a/compiler/rustc_span/src/symbol.rs
+++ b/compiler/rustc_span/src/symbol.rs
@@ -1207,6 +1207,7 @@ symbols! {
         require,
         residual,
         result,
+        resume,
         return_position_impl_trait_in_trait,
         return_type_notation,
         rhs,
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 164540cc16f..53bf38c0a34 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
@@ -2793,7 +2793,8 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
             | ObligationCauseCode::LetElse
             | ObligationCauseCode::BinOp { .. }
             | ObligationCauseCode::AscribeUserTypeProvePredicate(..)
-            | ObligationCauseCode::RustCall => {}
+            | ObligationCauseCode::RustCall
+            | ObligationCauseCode::DropImpl => {}
             ObligationCauseCode::SliceOrArrayElem => {
                 err.note("slice and array elements must have `Sized` type");
             }
diff --git a/compiler/rustc_ty_utils/src/instance.rs b/compiler/rustc_ty_utils/src/instance.rs
index eedf459ce8f..b10aaad5f2a 100644
--- a/compiler/rustc_ty_utils/src/instance.rs
+++ b/compiler/rustc_ty_utils/src/instance.rs
@@ -177,15 +177,55 @@ fn resolve_associated_item<'tcx>(
 
             Some(ty::Instance::new(leaf_def.item.def_id, substs))
         }
-        traits::ImplSource::Generator(generator_data) => Some(Instance {
-            def: ty::InstanceDef::Item(generator_data.generator_def_id),
-            substs: generator_data.substs,
-        }),
-        traits::ImplSource::Future(future_data) => Some(Instance {
-            def: ty::InstanceDef::Item(future_data.generator_def_id),
-            substs: future_data.substs,
-        }),
+        traits::ImplSource::Generator(generator_data) => {
+            if cfg!(debug_assertions) && tcx.item_name(trait_item_id) != sym::resume {
+                // For compiler developers who'd like to add new items to `Generator`,
+                // you either need to generate a shim body, or perhaps return
+                // `InstanceDef::Item` pointing to a trait default method body if
+                // it is given a default implementation by the trait.
+                span_bug!(
+                    tcx.def_span(generator_data.generator_def_id),
+                    "no definition for `{trait_ref}::{}` for built-in generator type",
+                    tcx.item_name(trait_item_id)
+                )
+            }
+            Some(Instance {
+                def: ty::InstanceDef::Item(generator_data.generator_def_id),
+                substs: generator_data.substs,
+            })
+        }
+        traits::ImplSource::Future(future_data) => {
+            if cfg!(debug_assertions) && tcx.item_name(trait_item_id) != sym::poll {
+                // For compiler developers who'd like to add new items to `Future`,
+                // you either need to generate a shim body, or perhaps return
+                // `InstanceDef::Item` pointing to a trait default method body if
+                // it is given a default implementation by the trait.
+                span_bug!(
+                    tcx.def_span(future_data.generator_def_id),
+                    "no definition for `{trait_ref}::{}` for built-in async generator type",
+                    tcx.item_name(trait_item_id)
+                )
+            }
+            Some(Instance {
+                def: ty::InstanceDef::Item(future_data.generator_def_id),
+                substs: future_data.substs,
+            })
+        }
         traits::ImplSource::Closure(closure_data) => {
+            if cfg!(debug_assertions)
+                && ![sym::call, sym::call_mut, sym::call_once]
+                    .contains(&tcx.item_name(trait_item_id))
+            {
+                // For compiler developers who'd like to add new items to `Fn`/`FnMut`/`FnOnce`,
+                // you either need to generate a shim body, or perhaps return
+                // `InstanceDef::Item` pointing to a trait default method body if
+                // it is given a default implementation by the trait.
+                span_bug!(
+                    tcx.def_span(closure_data.closure_def_id),
+                    "no definition for `{trait_ref}::{}` for built-in closure type",
+                    tcx.item_name(trait_item_id)
+                )
+            }
             let trait_closure_kind = tcx.fn_trait_kind_from_def_id(trait_id).unwrap();
             Instance::resolve_closure(
                 tcx,
@@ -195,11 +235,29 @@ fn resolve_associated_item<'tcx>(
             )
         }
         traits::ImplSource::FnPointer(ref data) => match data.fn_ty.kind() {
-            ty::FnDef(..) | ty::FnPtr(..) => Some(Instance {
-                def: ty::InstanceDef::FnPtrShim(trait_item_id, data.fn_ty),
-                substs: rcvr_substs,
-            }),
-            _ => None,
+            ty::FnDef(..) | ty::FnPtr(..) => {
+                if cfg!(debug_assertions)
+                    && ![sym::call, sym::call_mut, sym::call_once]
+                        .contains(&tcx.item_name(trait_item_id))
+                {
+                    // For compiler developers who'd like to add new items to `Fn`/`FnMut`/`FnOnce`,
+                    // you either need to generate a shim body, or perhaps return
+                    // `InstanceDef::Item` pointing to a trait default method body if
+                    // it is given a default implementation by the trait.
+                    bug!(
+                        "no definition for `{trait_ref}::{}` for built-in fn type",
+                        tcx.item_name(trait_item_id)
+                    )
+                }
+                Some(Instance {
+                    def: ty::InstanceDef::FnPtrShim(trait_item_id, data.fn_ty),
+                    substs: rcvr_substs,
+                })
+            }
+            _ => bug!(
+                "no built-in definition for `{trait_ref}::{}` for non-fn type",
+                tcx.item_name(trait_item_id)
+            ),
         },
         traits::ImplSource::Object(ref data) => {
             traits::get_vtable_index_of_object_method(tcx, data, trait_item_id).map(|index| {
diff --git a/src/librustdoc/lib.rs b/src/librustdoc/lib.rs
index 1d4892bcb2a..b6eb450d62b 100644
--- a/src/librustdoc/lib.rs
+++ b/src/librustdoc/lib.rs
@@ -156,15 +156,19 @@ pub fn main() {
         }
     }
 
-    rustc_driver::install_ice_hook();
+    rustc_driver::install_ice_hook(
+        "https://github.com/rust-lang/rust/issues/new\
+    ?labels=C-bug%2C+I-ICE%2C+T-rustdoc&template=ice.md",
+        |_| (),
+    );
 
-    // When using CI artifacts (with `download_stage1 = true`), tracing is unconditionally built
+    // When using CI artifacts with `download-rustc`, tracing is unconditionally built
     // with `--features=static_max_level_info`, which disables almost all rustdoc logging. To avoid
     // this, compile our own version of `tracing` that logs all levels.
     // NOTE: this compiles both versions of tracing unconditionally, because
     // - The compile time hit is not that bad, especially compared to rustdoc's incremental times, and
-    // - Otherwise, there's no warning that logging is being ignored when `download_stage1 = true`.
-    // NOTE: The reason this doesn't show double logging when `download_stage1 = false` and
+    // - Otherwise, there's no warning that logging is being ignored when `download-rustc` is enabled
+    // NOTE: The reason this doesn't show double logging when `download-rustc = false` and
     // `debug_logging = true` is because all rustc logging goes to its version of tracing (the one
     // in the sysroot), and all of rustdoc's logging goes to its version (the one in Cargo.toml).
     init_logging();
diff --git a/src/tools/clippy/src/driver.rs b/src/tools/clippy/src/driver.rs
index 205905d5091..59bf447a7cd 100644
--- a/src/tools/clippy/src/driver.rs
+++ b/src/tools/clippy/src/driver.rs
@@ -11,7 +11,6 @@
 // FIXME: switch to something more ergonomic here, once available.
 // (Currently there is no way to opt into sysroot crates without `extern crate`.)
 extern crate rustc_driver;
-extern crate rustc_errors;
 extern crate rustc_interface;
 extern crate rustc_session;
 extern crate rustc_span;
@@ -20,13 +19,10 @@ use rustc_interface::interface;
 use rustc_session::parse::ParseSess;
 use rustc_span::symbol::Symbol;
 
-use std::borrow::Cow;
 use std::env;
 use std::ops::Deref;
-use std::panic;
 use std::path::Path;
 use std::process::exit;
-use std::sync::LazyLock;
 
 /// If a command-line option matches `find_arg`, then apply the predicate `pred` on its value. If
 /// true, then return it. The parameter is assumed to be either `--arg=value` or `--arg value`.
@@ -198,66 +194,18 @@ You can use tool lints to allow or deny lints from your code, eg.:
 
 const BUG_REPORT_URL: &str = "https://github.com/rust-lang/rust-clippy/issues/new";
 
-type PanicCallback = dyn Fn(&panic::PanicInfo<'_>) + Sync + Send + 'static;
-static ICE_HOOK: LazyLock<Box<PanicCallback>> = LazyLock::new(|| {
-    let hook = panic::take_hook();
-    panic::set_hook(Box::new(|info| report_clippy_ice(info, BUG_REPORT_URL)));
-    hook
-});
-
-fn report_clippy_ice(info: &panic::PanicInfo<'_>, bug_report_url: &str) {
-    // Invoke our ICE handler, which prints the actual panic message and optionally a backtrace
-    (*ICE_HOOK)(info);
-
-    // Separate the output with an empty line
-    eprintln!();
-
-    let fallback_bundle = rustc_errors::fallback_fluent_bundle(rustc_driver::DEFAULT_LOCALE_RESOURCES.to_vec(), false);
-    let emitter = Box::new(rustc_errors::emitter::EmitterWriter::stderr(
-        rustc_errors::ColorConfig::Auto,
-        None,
-        None,
-        fallback_bundle,
-        false,
-        false,
-        None,
-        false,
-        false,
-        rustc_errors::TerminalUrl::No,
-    ));
-    let handler = rustc_errors::Handler::with_emitter(true, None, emitter);
-
-    // a .span_bug or .bug call has already printed what
-    // it wants to print.
-    if !info.payload().is::<rustc_errors::ExplicitBug>() {
-        let mut d = rustc_errors::Diagnostic::new(rustc_errors::Level::Bug, "unexpected panic");
-        handler.emit_diagnostic(&mut d);
-    }
-
-    let version_info = rustc_tools_util::get_version_info!();
-
-    let xs: Vec<Cow<'static, str>> = vec![
-        "the compiler unexpectedly panicked. this is a bug.".into(),
-        format!("we would appreciate a bug report: {bug_report_url}").into(),
-        format!("Clippy version: {version_info}").into(),
-    ];
-
-    for note in &xs {
-        handler.note_without_error(note.as_ref());
-    }
-
-    // If backtraces are enabled, also print the query stack
-    let backtrace = env::var_os("RUST_BACKTRACE").map_or(false, |x| &x != "0");
-
-    let num_frames = if backtrace { None } else { Some(2) };
-
-    interface::try_print_query_stack(&handler, num_frames);
-}
-
 #[allow(clippy::too_many_lines)]
 pub fn main() {
     rustc_driver::init_rustc_env_logger();
-    LazyLock::force(&ICE_HOOK);
+
+    rustc_driver::install_ice_hook(BUG_REPORT_URL, |handler| {
+        // FIXME: this macro calls unwrap internally but is called in a panicking context!  It's not
+        // as simple as moving the call from the hook to main, because `install_ice_hook` doesn't
+        // accept a generic closure.
+        let version_info = rustc_tools_util::get_version_info!();
+        handler.note_without_error(format!("Clippy version: {version_info}"));
+    });
+
     exit(rustc_driver::catch_with_exit_code(move || {
         let mut orig_args: Vec<String> = env::args().collect();
         let has_sysroot_arg = arg_value(&orig_args, "--sysroot", |_| true).is_some();
diff --git a/src/tools/miri/src/bin/miri.rs b/src/tools/miri/src/bin/miri.rs
index e4ca40570b7..65bc004fc4a 100644
--- a/src/tools/miri/src/bin/miri.rs
+++ b/src/tools/miri/src/bin/miri.rs
@@ -286,11 +286,10 @@ fn main() {
     // (`install_ice_hook` might change `RUST_BACKTRACE`.)
     let env_snapshot = env::vars_os().collect::<Vec<_>>();
 
-    // Earliest rustc setup.
-    rustc_driver::install_ice_hook();
-
     // If the environment asks us to actually be rustc, then do that.
     if let Some(crate_kind) = env::var_os("MIRI_BE_RUSTC") {
+        // Earliest rustc setup.
+        rustc_driver::install_ice_hook(rustc_driver::DEFAULT_BUG_REPORT_URL, |_| ());
         rustc_driver::init_rustc_env_logger();
 
         let target_crate = if crate_kind == "target" {
@@ -309,6 +308,9 @@ fn main() {
         )
     }
 
+    // Add an ICE bug report hook.
+    rustc_driver::install_ice_hook("https://github.com/rust-lang/miri/issues/new", |_| ());
+
     // Init loggers the Miri way.
     init_early_loggers();
 
diff --git a/src/tools/rustfmt/src/bin/main.rs b/src/tools/rustfmt/src/bin/main.rs
index be64559e877..47846424b06 100644
--- a/src/tools/rustfmt/src/bin/main.rs
+++ b/src/tools/rustfmt/src/bin/main.rs
@@ -1,3 +1,5 @@
+#![feature(rustc_private)]
+
 use anyhow::{format_err, Result};
 
 use io::Error as IoError;
@@ -19,7 +21,14 @@ use crate::rustfmt::{
     FormatReportFormatterBuilder, Input, Session, Verbosity,
 };
 
+const BUG_REPORT_URL: &str = "https://github.com/rust-lang/rustfmt/issues/new?labels=bug";
+
+// N.B. these crates are loaded from the sysroot, so they need extern crate.
+extern crate rustc_driver;
+
 fn main() {
+    rustc_driver::install_ice_hook(BUG_REPORT_URL, |_| ());
+
     env_logger::Builder::from_env("RUSTFMT_LOG").init();
     let opts = make_opts();
 
diff --git a/tests/run-make/issue-109934-lto-debuginfo/Makefile b/tests/run-make/issue-109934-lto-debuginfo/Makefile
new file mode 100644
index 00000000000..3b7a99d3dbc
--- /dev/null
+++ b/tests/run-make/issue-109934-lto-debuginfo/Makefile
@@ -0,0 +1,12 @@
+# ignore-cross-compile
+include ../tools.mk
+
+# With the upgrade to LLVM 16, this was getting:
+#
+#   error: Cannot represent a difference across sections
+#
+# The error stemmed from DI function definitions under type scopes, fixed by
+# only declaring in type scope and defining the subprogram elsewhere.
+
+all:
+	$(RUSTC) lib.rs --test -C lto=fat -C debuginfo=2 -C incremental=$(TMPDIR)/inc-fat
diff --git a/tests/run-make/issue-109934-lto-debuginfo/lib.rs b/tests/run-make/issue-109934-lto-debuginfo/lib.rs
new file mode 100644
index 00000000000..c405928bd18
--- /dev/null
+++ b/tests/run-make/issue-109934-lto-debuginfo/lib.rs
@@ -0,0 +1,9 @@
+extern crate alloc;
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn something_alloc() {
+        assert_eq!(Vec::<u32>::new(), Vec::<u32>::new());
+    }
+}
diff --git a/tests/rustdoc-ui/ice-bug-report-url.rs b/tests/rustdoc-ui/ice-bug-report-url.rs
new file mode 100644
index 00000000000..cc066447d31
--- /dev/null
+++ b/tests/rustdoc-ui/ice-bug-report-url.rs
@@ -0,0 +1,14 @@
+// compile-flags: -Ztreat-err-as-bug
+// failure-status: 101
+// error-pattern: aborting due to
+// error-pattern: we would appreciate a bug report: https://github.com/rust-lang/rust/issues/new?labels=C-bug%2C+I-ICE%2C+T-rustdoc&template=ice.md
+
+// normalize-stderr-test "note: compiler flags.*\n\n" -> ""
+// normalize-stderr-test "note: rustc.*running on.*" -> "note: rustc {version} running on {platform}"
+// normalize-stderr-test "thread.*panicked at .*, compiler.*" -> "thread panicked at 'aborting due to `-Z treat-err-as-bug`'"
+// normalize-stderr-test "\s*\d{1,}: .*\n" -> ""
+// normalize-stderr-test "\s at .*\n" -> ""
+// normalize-stderr-test ".*note: Some details are omitted.*\n" -> ""
+
+fn wrong()
+//~^ ERROR expected one of
diff --git a/tests/rustdoc-ui/ice-bug-report-url.stderr b/tests/rustdoc-ui/ice-bug-report-url.stderr
new file mode 100644
index 00000000000..cfb73a9b919
--- /dev/null
+++ b/tests/rustdoc-ui/ice-bug-report-url.stderr
@@ -0,0 +1,16 @@
+error: expected one of `->`, `where`, or `{`, found `<eof>`
+  --> $DIR/ice-bug-report-url.rs:13:10
+   |
+LL | fn wrong()
+   |          ^ expected one of `->`, `where`, or `{`
+
+thread panicked at 'aborting due to `-Z treat-err-as-bug`'
+stack backtrace:
+error: the compiler unexpectedly panicked. this is a bug.
+
+note: we would appreciate a bug report: https://github.com/rust-lang/rust/issues/new?labels=C-bug%2C+I-ICE%2C+T-rustdoc&template=ice.md
+
+note: rustc {version} running on {platform}
+
+query stack during panic:
+end of query stack
diff --git a/tests/ui-fulldeps/stable-mir/crate-info.rs b/tests/ui-fulldeps/stable-mir/crate-info.rs
index 95f27efa771..1454d6dde6c 100644
--- a/tests/ui-fulldeps/stable-mir/crate-info.rs
+++ b/tests/ui-fulldeps/stable-mir/crate-info.rs
@@ -60,6 +60,24 @@ fn test_stable_mir(tcx: TyCtxt<'_>) {
         stable_mir::mir::Terminator::Call { .. } => {}
         other => panic!("{other:?}"),
     }
+
+    let drop = get_item(tcx, &items, (DefKind::Fn, "drop")).unwrap();
+    let body = drop.body();
+    assert_eq!(body.blocks.len(), 2);
+    let block = &body.blocks[0];
+    match &block.terminator {
+        stable_mir::mir::Terminator::Drop { .. } => {}
+        other => panic!("{other:?}"),
+    }
+
+    let assert = get_item(tcx, &items, (DefKind::Fn, "assert")).unwrap();
+    let body = assert.body();
+    assert_eq!(body.blocks.len(), 2);
+    let block = &body.blocks[0];
+    match &block.terminator {
+        stable_mir::mir::Terminator::Assert { .. } => {}
+        other => panic!("{other:?}"),
+    }
 }
 
 // Use internal API to find a function in a crate.
@@ -131,6 +149,12 @@ fn generate_input(path: &str) -> std::io::Result<()> {
         let x_64 = foo::bar(x);
         let y_64 = foo::bar(y);
         x_64.wrapping_add(y_64)
+    }}
+
+    pub fn drop(_: String) {{}}
+
+    pub fn assert(x: i32) -> i32 {{
+        x + 1
     }}"#
     )?;
     Ok(())
diff --git a/tests/ui/dropck/explicit-drop-bounds.bad1.stderr b/tests/ui/dropck/explicit-drop-bounds.bad1.stderr
new file mode 100644
index 00000000000..3b506c7e7ec
--- /dev/null
+++ b/tests/ui/dropck/explicit-drop-bounds.bad1.stderr
@@ -0,0 +1,35 @@
+error[E0277]: the trait bound `T: Copy` is not satisfied
+  --> $DIR/explicit-drop-bounds.rs:27:18
+   |
+LL | impl<T> Drop for DropMe<T>
+   |                  ^^^^^^^^^ the trait `Copy` is not implemented for `T`
+   |
+note: required by a bound in `DropMe`
+  --> $DIR/explicit-drop-bounds.rs:7:18
+   |
+LL | struct DropMe<T: Copy>(T);
+   |                  ^^^^ required by this bound in `DropMe`
+help: consider further restricting type parameter `T`
+   |
+LL |     [T; 1]: Copy, T: std::marker::Copy // But `[T; 1]: Copy` does not imply `T: Copy`
+   |                 ~~~~~~~~~~~~~~~~~~~~~~
+
+error[E0277]: the trait bound `T: Copy` is not satisfied
+  --> $DIR/explicit-drop-bounds.rs:32:13
+   |
+LL |     fn drop(&mut self) {}
+   |             ^^^^^^^^^ the trait `Copy` is not implemented for `T`
+   |
+note: required by a bound in `DropMe`
+  --> $DIR/explicit-drop-bounds.rs:7:18
+   |
+LL | struct DropMe<T: Copy>(T);
+   |                  ^^^^ required by this bound in `DropMe`
+help: consider further restricting type parameter `T`
+   |
+LL |     [T; 1]: Copy, T: std::marker::Copy // But `[T; 1]: Copy` does not imply `T: Copy`
+   |                 ~~~~~~~~~~~~~~~~~~~~~~
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/dropck/explicit-drop-bounds.bad2.stderr b/tests/ui/dropck/explicit-drop-bounds.bad2.stderr
new file mode 100644
index 00000000000..832af3e521a
--- /dev/null
+++ b/tests/ui/dropck/explicit-drop-bounds.bad2.stderr
@@ -0,0 +1,35 @@
+error[E0277]: the trait bound `T: Copy` is not satisfied
+  --> $DIR/explicit-drop-bounds.rs:37:18
+   |
+LL | impl<T> Drop for DropMe<T>
+   |                  ^^^^^^^^^ the trait `Copy` is not implemented for `T`
+   |
+note: required by a bound in `DropMe`
+  --> $DIR/explicit-drop-bounds.rs:7:18
+   |
+LL | struct DropMe<T: Copy>(T);
+   |                  ^^^^ required by this bound in `DropMe`
+help: consider restricting type parameter `T`
+   |
+LL | impl<T: std::marker::Copy> Drop for DropMe<T>
+   |       +++++++++++++++++++
+
+error[E0277]: the trait bound `T: Copy` is not satisfied
+  --> $DIR/explicit-drop-bounds.rs:40:13
+   |
+LL |     fn drop(&mut self) {}
+   |             ^^^^^^^^^ the trait `Copy` is not implemented for `T`
+   |
+note: required by a bound in `DropMe`
+  --> $DIR/explicit-drop-bounds.rs:7:18
+   |
+LL | struct DropMe<T: Copy>(T);
+   |                  ^^^^ required by this bound in `DropMe`
+help: consider restricting type parameter `T`
+   |
+LL | impl<T: std::marker::Copy> Drop for DropMe<T>
+   |       +++++++++++++++++++
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/dropck/explicit-drop-bounds.rs b/tests/ui/dropck/explicit-drop-bounds.rs
new file mode 100644
index 00000000000..ab6f33c0999
--- /dev/null
+++ b/tests/ui/dropck/explicit-drop-bounds.rs
@@ -0,0 +1,44 @@
+// revisions: good1 good2 bad1 bad2
+//[good1] check-pass
+//[good2] check-pass
+
+use std::ops::Drop;
+
+struct DropMe<T: Copy>(T);
+
+#[cfg(good1)]
+impl<T> Drop for DropMe<T>
+where
+    T: Copy + Clone,
+{
+    fn drop(&mut self) {}
+}
+
+#[cfg(good2)]
+impl<T> Drop for DropMe<T>
+where
+    T: Copy,
+    [T; 1]: Copy, // Trivial bound implied by `T: Copy`
+{
+    fn drop(&mut self) {}
+}
+
+#[cfg(bad1)]
+impl<T> Drop for DropMe<T>
+//[bad1]~^ ERROR the trait bound `T: Copy` is not satisfied
+where
+    [T; 1]: Copy, // But `[T; 1]: Copy` does not imply `T: Copy`
+{
+    fn drop(&mut self) {}
+    //[bad1]~^ ERROR the trait bound `T: Copy` is not satisfied
+}
+
+#[cfg(bad2)]
+impl<T> Drop for DropMe<T>
+//[bad2]~^ ERROR the trait bound `T: Copy` is not satisfied
+{
+    fn drop(&mut self) {}
+    //[bad2]~^ ERROR the trait bound `T: Copy` is not satisfied
+}
+
+fn main() {}
diff --git a/tests/ui/dropck/explicit-implied-outlives.bad1.stderr b/tests/ui/dropck/explicit-implied-outlives.bad1.stderr
new file mode 100644
index 00000000000..bf6d70e7d37
--- /dev/null
+++ b/tests/ui/dropck/explicit-implied-outlives.bad1.stderr
@@ -0,0 +1,15 @@
+error[E0367]: `Drop` impl requires `T: 'static` but the struct it is implemented for does not
+  --> $DIR/explicit-implied-outlives.rs:28:8
+   |
+LL |     T: 'static,
+   |        ^^^^^^^
+   |
+note: the implementor must specify the same requirement
+  --> $DIR/explicit-implied-outlives.rs:7:1
+   |
+LL | struct DropMe<'a, T>(&'a T);
+   | ^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0367`.
diff --git a/tests/ui/dropck/explicit-implied-outlives.bad2.stderr b/tests/ui/dropck/explicit-implied-outlives.bad2.stderr
new file mode 100644
index 00000000000..27a15170bdd
--- /dev/null
+++ b/tests/ui/dropck/explicit-implied-outlives.bad2.stderr
@@ -0,0 +1,15 @@
+error[E0367]: `Drop` impl requires `'a: 'static` but the struct it is implemented for does not
+  --> $DIR/explicit-implied-outlives.rs:37:9
+   |
+LL |     'a: 'static,
+   |         ^^^^^^^
+   |
+note: the implementor must specify the same requirement
+  --> $DIR/explicit-implied-outlives.rs:7:1
+   |
+LL | struct DropMe<'a, T>(&'a T);
+   | ^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0367`.
diff --git a/tests/ui/dropck/explicit-implied-outlives.rs b/tests/ui/dropck/explicit-implied-outlives.rs
new file mode 100644
index 00000000000..fa446591f3d
--- /dev/null
+++ b/tests/ui/dropck/explicit-implied-outlives.rs
@@ -0,0 +1,43 @@
+// revisions: good1 good2 bad1 bad2
+//[good1] check-pass
+//[good2] check-pass
+
+use std::ops::Drop;
+
+struct DropMe<'a, T>(&'a T);
+
+#[cfg(good1)]
+impl<'a, T> Drop for DropMe<'a, T>
+where
+    T: 'a, // Implied by struct, explicit on impl
+{
+    fn drop(&mut self) {}
+}
+
+#[cfg(good2)]
+impl<'a, T> Drop for DropMe<'a, T>
+where
+    'static: 'a, // Trivial bound
+{
+    fn drop(&mut self) {}
+}
+
+#[cfg(bad1)]
+impl<'a, T> Drop for DropMe<'a, T>
+where
+    T: 'static,
+    //[bad1]~^ ERROR `Drop` impl requires `T: 'static`
+{
+    fn drop(&mut self) {}
+}
+
+#[cfg(bad2)]
+impl<'a, T> Drop for DropMe<'a, T>
+where
+    'a: 'static,
+    //[bad2]~^ ERROR `Drop` impl requires `'a: 'static`
+{
+    fn drop(&mut self) {}
+}
+
+fn main() {}
diff --git a/tests/ui/dropck/transitive-outlives-2.rs b/tests/ui/dropck/transitive-outlives-2.rs
new file mode 100644
index 00000000000..87154e25d40
--- /dev/null
+++ b/tests/ui/dropck/transitive-outlives-2.rs
@@ -0,0 +1,18 @@
+// check-pass
+
+use std::marker::PhantomData;
+use std::ops::Drop;
+
+// a >= b >= c >= a implies a = b = c
+struct DropMe<'a: 'b, 'b: 'c, 'c: 'a>(
+    PhantomData<&'a ()>,
+    PhantomData<&'b ()>,
+    PhantomData<&'c ()>,
+);
+
+// a >= b, a >= c, b >= a, c >= a implies a = b = c
+impl<'a: 'b + 'c, 'b: 'a, 'c: 'a> Drop for DropMe<'a, 'b, 'c> {
+    fn drop(&mut self) {}
+}
+
+fn main() {}
diff --git a/tests/ui/dropck/transitive-outlives.bad.stderr b/tests/ui/dropck/transitive-outlives.bad.stderr
new file mode 100644
index 00000000000..da5088b27b4
--- /dev/null
+++ b/tests/ui/dropck/transitive-outlives.bad.stderr
@@ -0,0 +1,15 @@
+error[E0367]: `Drop` impl requires `'a: 'c` but the struct it is implemented for does not
+  --> $DIR/transitive-outlives.rs:20:9
+   |
+LL |     'a: 'c,
+   |         ^^
+   |
+note: the implementor must specify the same requirement
+  --> $DIR/transitive-outlives.rs:7:1
+   |
+LL | struct DropMe<'a, 'b: 'a, 'c: 'b>(PhantomData<&'a ()>, PhantomData<&'b ()>, PhantomData<&'c ()>);
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0367`.
diff --git a/tests/ui/dropck/transitive-outlives.rs b/tests/ui/dropck/transitive-outlives.rs
new file mode 100644
index 00000000000..d071664abde
--- /dev/null
+++ b/tests/ui/dropck/transitive-outlives.rs
@@ -0,0 +1,26 @@
+// revisions: good bad
+//[good] check-pass
+
+use std::marker::PhantomData;
+use std::ops::Drop;
+
+struct DropMe<'a, 'b: 'a, 'c: 'b>(PhantomData<&'a ()>, PhantomData<&'b ()>, PhantomData<&'c ()>);
+
+#[cfg(good)]
+impl<'a, 'b, 'c> Drop for DropMe<'a, 'b, 'c>
+where
+    'c: 'a,
+{
+    fn drop(&mut self) {}
+}
+
+#[cfg(bad)]
+impl<'a, 'b, 'c> Drop for DropMe<'a, 'b, 'c>
+where
+    'a: 'c,
+    //[bad]~^ ERROR `Drop` impl requires `'a: 'c`
+{
+    fn drop(&mut self) {}
+}
+
+fn main() {}
diff --git a/tests/ui/dropck/trivial-impl-bounds.rs b/tests/ui/dropck/trivial-impl-bounds.rs
new file mode 100644
index 00000000000..a8f5d2c354b
--- /dev/null
+++ b/tests/ui/dropck/trivial-impl-bounds.rs
@@ -0,0 +1,34 @@
+// revisions: good1 good2 good3
+// check-pass
+
+use std::ops::Drop;
+
+struct Foo;
+
+const X: usize = 1;
+
+#[cfg(good1)]
+impl Drop for Foo
+where
+    [(); X]:, // Trivial WF bound
+{
+    fn drop(&mut self) {}
+}
+
+#[cfg(good2)]
+impl Drop for Foo
+where
+    for<'a> &'a (): Copy, // Trivial trait bound
+{
+    fn drop(&mut self) {}
+}
+
+#[cfg(good3)]
+impl Drop for Foo
+where
+    for<'a> &'a (): 'a, // Trivial outlives bound
+{
+    fn drop(&mut self) {}
+}
+
+fn main() {}
diff --git a/tests/ui/parser/eq-less-to-less-eq.rs b/tests/ui/parser/eq-less-to-less-eq.rs
new file mode 100644
index 00000000000..23c6c59d7a6
--- /dev/null
+++ b/tests/ui/parser/eq-less-to-less-eq.rs
@@ -0,0 +1,33 @@
+fn foo() {
+    let a = 0;
+    let b = 4;
+    if a =< b { //~ERROR
+        println!("yay!");
+    }
+}
+
+fn bar() {
+    let a = 0;
+    let b = 4;
+    if a = <b { //~ERROR
+        println!("yay!");
+    }
+}
+
+fn baz() {
+    let a = 0;
+    let b = 4;
+    if a = < b { //~ERROR
+        println!("yay!");
+    }
+}
+
+fn qux() {
+    let a = 0;
+    let b = 4;
+    if a =< i32>::abs(-4) { //~ERROR: mismatched types
+        println!("yay!");
+    }
+}
+
+fn main() {}
diff --git a/tests/ui/parser/eq-less-to-less-eq.stderr b/tests/ui/parser/eq-less-to-less-eq.stderr
new file mode 100644
index 00000000000..4717d8287ff
--- /dev/null
+++ b/tests/ui/parser/eq-less-to-less-eq.stderr
@@ -0,0 +1,34 @@
+error: expected one of `!`, `(`, `+`, `::`, `<`, `>`, or `as`, found `{`
+  --> $DIR/eq-less-to-less-eq.rs:4:15
+   |
+LL |     if a =< b {
+   |          --   ^ expected one of 7 possible tokens
+   |          |
+   |          help: did you mean: `<=`
+
+error: expected one of `!`, `(`, `+`, `::`, `<`, `>`, or `as`, found `{`
+  --> $DIR/eq-less-to-less-eq.rs:12:15
+   |
+LL |     if a = <b {
+   |               ^ expected one of 7 possible tokens
+
+error: expected one of `!`, `(`, `+`, `::`, `<`, `>`, or `as`, found `{`
+  --> $DIR/eq-less-to-less-eq.rs:20:16
+   |
+LL |     if a = < b {
+   |                ^ expected one of 7 possible tokens
+
+error[E0308]: mismatched types
+  --> $DIR/eq-less-to-less-eq.rs:28:8
+   |
+LL |     if a =< i32>::abs(-4) {
+   |        ^^^^^^^^^^^^^^^^^^ expected `bool`, found `()`
+   |
+help: you might have meant to compare for equality
+   |
+LL |     if a ==< i32>::abs(-4) {
+   |           +
+
+error: aborting due to 4 previous errors
+
+For more information about this error, try `rustc --explain E0308`.
diff --git a/tests/ui/traits/non_lifetime_binders/drop-impl-pred.no.stderr b/tests/ui/traits/non_lifetime_binders/drop-impl-pred.no.stderr
new file mode 100644
index 00000000000..a985b1a6e12
--- /dev/null
+++ b/tests/ui/traits/non_lifetime_binders/drop-impl-pred.no.stderr
@@ -0,0 +1,24 @@
+warning: the feature `non_lifetime_binders` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/drop-impl-pred.rs:6:12
+   |
+LL | #![feature(non_lifetime_binders)]
+   |            ^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: see issue #108185 <https://github.com/rust-lang/rust/issues/108185> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
+error[E0367]: `Drop` impl requires `H: Foo` but the struct it is implemented for does not
+  --> $DIR/drop-impl-pred.rs:19:15
+   |
+LL |     for<H> H: Foo,
+   |               ^^^
+   |
+note: the implementor must specify the same requirement
+  --> $DIR/drop-impl-pred.rs:12:1
+   |
+LL | struct Bar<T>(T) where T: Foo;
+   | ^^^^^^^^^^^^^
+
+error: aborting due to previous error; 1 warning emitted
+
+For more information about this error, try `rustc --explain E0367`.
diff --git a/tests/ui/traits/non_lifetime_binders/drop-impl-pred.rs b/tests/ui/traits/non_lifetime_binders/drop-impl-pred.rs
new file mode 100644
index 00000000000..c65b5ea9ba4
--- /dev/null
+++ b/tests/ui/traits/non_lifetime_binders/drop-impl-pred.rs
@@ -0,0 +1,25 @@
+// revisions: no yes
+//[yes] check-pass
+
+// Issue 110557
+
+#![feature(non_lifetime_binders)]
+//~^ WARN the feature `non_lifetime_binders` is incomplete
+
+pub trait Foo {}
+
+#[cfg(no)]
+struct Bar<T>(T) where T: Foo;
+
+#[cfg(yes)]
+struct Bar<T>(T) where for<H> H: Foo;
+
+impl<T> Drop for Bar<T>
+where
+    for<H> H: Foo,
+//[no]~^ ERROR `Drop` impl requires `H: Foo` but the struct it is implemented for does not
+{
+    fn drop(&mut self) {}
+}
+
+fn main() {}
diff --git a/tests/ui/traits/non_lifetime_binders/drop-impl-pred.yes.stderr b/tests/ui/traits/non_lifetime_binders/drop-impl-pred.yes.stderr
new file mode 100644
index 00000000000..165cf2ee13d
--- /dev/null
+++ b/tests/ui/traits/non_lifetime_binders/drop-impl-pred.yes.stderr
@@ -0,0 +1,11 @@
+warning: the feature `non_lifetime_binders` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/drop-impl-pred.rs:6:12
+   |
+LL | #![feature(non_lifetime_binders)]
+   |            ^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: see issue #108185 <https://github.com/rust-lang/rust/issues/108185> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
+warning: 1 warning emitted
+