interpret, miri: uniform treatments of intrinsics/functions with and without return block

compiler/rustc_const_eval/src/const_eval/machine.rs

@@ -467,19 +467,6 @@ impl<'mir, 'tcx> interpret::Machine<'mir, 'tcx> for CompileTimeInterpreter<'mir,
         let intrinsic_name = ecx.tcx.item_name(instance.def_id());
 
         // CTFE-specific intrinsics.
-        let Some(ret) = target else {
-            // Handle diverging intrinsics. We can't handle any of them (that are not already
-            // handled above), but check if there is a fallback body.
-            if ecx.tcx.intrinsic(instance.def_id()).unwrap().must_be_overridden {
-                throw_unsup_format!(
-                    "intrinsic `{intrinsic_name}` is not supported at compile-time"
-                );
-            }
-            return Ok(Some(ty::Instance {
-                def: ty::InstanceDef::Item(instance.def_id()),
-                args: instance.args,
-            }));
-        };
         match intrinsic_name {
             sym::ptr_guaranteed_cmp => {
                 let a = ecx.read_scalar(&args[0])?;
@@ -559,7 +546,8 @@ impl<'mir, 'tcx> interpret::Machine<'mir, 'tcx> for CompileTimeInterpreter<'mir,
             }
         }
 
-        ecx.go_to_block(ret);
+        // Intrinsic is done, jump to next block.
+        ecx.return_to_block(target)?;
         Ok(None)
     }
 

compiler/rustc_const_eval/src/interpret/intrinsics.rs

@@ -113,10 +113,6 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
     ) -> InterpResult<'tcx, bool> {
         let instance_args = instance.args;
         let intrinsic_name = self.tcx.item_name(instance.def_id());
-        let Some(ret) = ret else {
-            // We don't support any intrinsic without return place.
-            return Ok(false);
-        };
 
         match intrinsic_name {
             sym::caller_location => {
@@ -376,7 +372,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                     };
 
                     M::panic_nounwind(self, &msg)?;
-                    // Skip the `go_to_block` at the end.
+                    // Skip the `return_to_block` at the end (we panicked, we do not return).
                     return Ok(true);
                 }
             }
@@ -437,11 +433,12 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                 self.write_scalar(Scalar::from_target_usize(align.bytes(), self), dest)?;
             }
 
+            // Unsupported intrinsic: skip the return_to_block below.
             _ => return Ok(false),
         }
 
         trace!("{:?}", self.dump_place(&dest.clone().into()));
-        self.go_to_block(ret);
+        self.return_to_block(ret)?;
         Ok(true)
     }
 

src/tools/miri/src/lib.rs

@@ -95,6 +95,7 @@ pub use rustc_const_eval::interpret::*;
 #[doc(no_inline)]
 pub use rustc_const_eval::interpret::{self, AllocMap, PlaceTy, Provenance as _};
 
+pub use crate::shims::EmulateItemResult;
 pub use crate::shims::env::{EnvVars, EvalContextExt as _};
 pub use crate::shims::foreign_items::{DynSym, EvalContextExt as _};
 pub use crate::shims::intrinsics::EvalContextExt as _;

src/tools/miri/src/shims/alloc.rs

@@ -4,7 +4,6 @@ use rustc_ast::expand::allocator::AllocatorKind;
 use rustc_target::abi::{Align, Size};
 
 use crate::*;
-use shims::foreign_items::EmulateForeignItemResult;
 
 /// Check some basic requirements for this allocation request:
 /// non-zero size, power-of-two alignment.
@@ -55,12 +54,12 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
     fn emulate_allocator(
         &mut self,
         default: impl FnOnce(&mut MiriInterpCx<'mir, 'tcx>) -> InterpResult<'tcx>,
-    ) -> InterpResult<'tcx, EmulateForeignItemResult> {
+    ) -> InterpResult<'tcx, EmulateItemResult> {
         let this = self.eval_context_mut();
 
         let Some(allocator_kind) = this.tcx.allocator_kind(()) else {
             // in real code, this symbol does not exist without an allocator
-            return Ok(EmulateForeignItemResult::NotSupported);
+            return Ok(EmulateItemResult::NotSupported);
         };
 
         match allocator_kind {
@@ -70,11 +69,11 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                 // and not execute any Miri shim. Somewhat unintuitively doing so is done
                 // by returning `NotSupported`, which triggers the `lookup_exported_symbol`
                 // fallback case in `emulate_foreign_item`.
-                return Ok(EmulateForeignItemResult::NotSupported);
+                return Ok(EmulateItemResult::NotSupported);
             }
             AllocatorKind::Default => {
                 default(this)?;
-                Ok(EmulateForeignItemResult::NeedsJumping)
+                Ok(EmulateItemResult::NeedsJumping)
             }
         }
     }

src/tools/miri/src/shims/foreign_items.rs

@@ -28,16 +28,6 @@ impl DynSym {
     }
 }
 
-/// Returned by `emulate_foreign_item_inner`.
-pub enum EmulateForeignItemResult {
-    /// The caller is expected to jump to the return block.
-    NeedsJumping,
-    /// Jumping has already been taken care of.
-    AlreadyJumped,
-    /// The item is not supported.
-    NotSupported,
-}
-
 impl<'mir, 'tcx: 'mir> EvalContextExt<'mir, 'tcx> for crate::MiriInterpCx<'mir, 'tcx> {}
 pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
     /// Emulates calling a foreign item, failing if the item is not supported.
@@ -58,15 +48,8 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
         let this = self.eval_context_mut();
         let tcx = this.tcx.tcx;
 
-        // First: functions that diverge.
+        // Some shims forward to other MIR bodies.
-        let ret = match ret {
-            None =>
         match link_name.as_str() {
-                    "miri_start_unwind" => {
-                        // `check_shim` happens inside `handle_miri_start_unwind`.
-                        this.handle_miri_start_unwind(abi, link_name, args, unwind)?;
-                        return Ok(None);
-                    }
             // This matches calls to the foreign item `panic_impl`.
             // The implementation is provided by the function with the `#[panic_handler]` attribute.
             "panic_impl" => {
@@ -95,47 +78,17 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                     .expect("missing alloc error handler symbol");
                 return Ok(Some(handler));
             }
-                    #[rustfmt::skip]
+            _ => {}
-                    | "exit"
-                    | "ExitProcess"
-                    => {
-                        let exp_abi = if link_name.as_str() == "exit" {
-                            Abi::C { unwind: false }
-                        } else {
-                            Abi::System { unwind: false }
-                        };
-                        let [code] = this.check_shim(abi, exp_abi, link_name, args)?;
-                        // it's really u32 for ExitProcess, but we have to put it into the `Exit` variant anyway
-                        let code = this.read_scalar(code)?.to_i32()?;
-                        throw_machine_stop!(TerminationInfo::Exit { code: code.into(), leak_check: false });
         }
-                    "abort" => {
-                        let [] = this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?;
-                        throw_machine_stop!(TerminationInfo::Abort(
-                            "the program aborted execution".to_owned()
-                        ))
-                    }
-                    _ => {
-                        if let Some(body) = this.lookup_exported_symbol(link_name)? {
-                            return Ok(Some(body));
-                        }
-                        this.handle_unsupported(format!(
-                            "can't call (diverging) foreign function: {link_name}"
-                        ))?;
-                        return Ok(None);
-                    }
-                },
-            Some(p) => p,
-        };
 
-        // Second: functions that return immediately.
+        // The rest either implements the logic, or falls back to `lookup_exported_symbol`.
-        match this.emulate_foreign_item_inner(link_name, abi, args, dest)? {
+        match this.emulate_foreign_item_inner(link_name, abi, args, dest, unwind)? {
-            EmulateForeignItemResult::NeedsJumping => {
+            EmulateItemResult::NeedsJumping => {
                 trace!("{:?}", this.dump_place(&dest.clone().into()));
-                this.go_to_block(ret);
+                this.return_to_block(ret)?;
             }
-            EmulateForeignItemResult::AlreadyJumped => (),
+            EmulateItemResult::AlreadyJumped => (),
-            EmulateForeignItemResult::NotSupported => {
+            EmulateItemResult::NotSupported => {
                 if let Some(body) = this.lookup_exported_symbol(link_name)? {
                     return Ok(Some(body));
                 }
@@ -243,7 +196,8 @@ trait EvalContextExtPriv<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
         abi: Abi,
         args: &[OpTy<'tcx, Provenance>],
         dest: &MPlaceTy<'tcx, Provenance>,
-    ) -> InterpResult<'tcx, EmulateForeignItemResult> {
+        unwind: mir::UnwindAction,
+    ) -> InterpResult<'tcx, EmulateItemResult> {
         let this = self.eval_context_mut();
 
         // First deal with any external C functions in linked .so file.
@@ -254,7 +208,7 @@ trait EvalContextExtPriv<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
             // by the specified `.so` file; we should continue and check if it corresponds to
             // a provided shim.
             if this.call_external_c_fct(link_name, dest, args)? {
-                return Ok(EmulateForeignItemResult::NeedsJumping);
+                return Ok(EmulateItemResult::NeedsJumping);
             }
         }
 
@@ -298,6 +252,11 @@ trait EvalContextExtPriv<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
         // shim, add it to the corresponding submodule.
         match link_name.as_str() {
             // Miri-specific extern functions
+            "miri_start_unwind" => {
+                // `check_shim` happens inside `handle_miri_start_unwind`.
+                this.handle_miri_start_unwind(abi, link_name, args, unwind)?;
+                return Ok(EmulateItemResult::AlreadyJumped);
+            }
             "miri_run_provenance_gc" => {
                 let [] = this.check_shim(abi, Abi::Rust, link_name, args)?;
                 this.run_provenance_gc();
@@ -362,29 +321,24 @@ trait EvalContextExtPriv<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                 // Return value: 0 on success, otherwise the size it would have needed.
                 this.write_int(if success { 0 } else { needed_size }, dest)?;
             }
-
             // Obtains the size of a Miri backtrace. See the README for details.
             "miri_backtrace_size" => {
                 this.handle_miri_backtrace_size(abi, link_name, args, dest)?;
             }
-
             // Obtains a Miri backtrace. See the README for details.
             "miri_get_backtrace" => {
                 // `check_shim` happens inside `handle_miri_get_backtrace`.
                 this.handle_miri_get_backtrace(abi, link_name, args, dest)?;
             }
-
             // Resolves a Miri backtrace frame. See the README for details.
             "miri_resolve_frame" => {
                 // `check_shim` happens inside `handle_miri_resolve_frame`.
                 this.handle_miri_resolve_frame(abi, link_name, args, dest)?;
             }
-
             // Writes the function and file names of a Miri backtrace frame into a user provided buffer. See the README for details.
             "miri_resolve_frame_names" => {
                 this.handle_miri_resolve_frame_names(abi, link_name, args)?;
             }
-
             // Writes some bytes to the interpreter's stdout/stderr. See the
             // README for details.
             "miri_write_to_stdout" | "miri_write_to_stderr" => {
@@ -398,7 +352,6 @@ trait EvalContextExtPriv<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                     _ => unreachable!(),
                 };
             }
-
             // Promises that a pointer has a given symbolic alignment.
             "miri_promise_symbolic_alignment" => {
                 use rustc_target::abi::AlignFromBytesError;
@@ -442,6 +395,25 @@ trait EvalContextExtPriv<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                 }
             }
 
+            // Aborting the process.
+            "exit" | "ExitProcess" => {
+                let exp_abi = if link_name.as_str() == "exit" {
+                    Abi::C { unwind: false }
+                } else {
+                    Abi::System { unwind: false }
+                };
+                let [code] = this.check_shim(abi, exp_abi, link_name, args)?;
+                // it's really u32 for ExitProcess, but we have to put it into the `Exit` variant anyway
+                let code = this.read_scalar(code)?.to_i32()?;
+                throw_machine_stop!(TerminationInfo::Exit { code: code.into(), leak_check: false });
+            }
+            "abort" => {
+                let [] = this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?;
+                throw_machine_stop!(TerminationInfo::Abort(
+                    "the program aborted execution".to_owned()
+                ))
+            }
+
             // Standard C allocation
             "malloc" => {
                 let [size] = this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?;
@@ -504,7 +476,7 @@ trait EvalContextExtPriv<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                     "__rust_alloc" => return this.emulate_allocator(default),
                     "miri_alloc" => {
                         default(this)?;
-                        return Ok(EmulateForeignItemResult::NeedsJumping);
+                        return Ok(EmulateItemResult::NeedsJumping);
                     }
                     _ => unreachable!(),
                 }
@@ -564,7 +536,7 @@ trait EvalContextExtPriv<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                     }
                     "miri_dealloc" => {
                         default(this)?;
-                        return Ok(EmulateForeignItemResult::NeedsJumping);
+                        return Ok(EmulateItemResult::NeedsJumping);
                     }
                     _ => unreachable!(),
                 }
@@ -966,11 +938,11 @@ trait EvalContextExtPriv<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                         shims::windows::foreign_items::EvalContextExt::emulate_foreign_item_inner(
                             this, link_name, abi, args, dest,
                         ),
-                    _ => Ok(EmulateForeignItemResult::NotSupported),
+                    _ => Ok(EmulateItemResult::NotSupported),
                 },
         };
         // We only fall through to here if we did *not* hit the `_` arm above,
         // i.e., if we actually emulated the function with one of the shims.
-        Ok(EmulateForeignItemResult::NeedsJumping)
+        Ok(EmulateItemResult::NeedsJumping)
     }
 }

src/tools/miri/src/shims/intrinsics/atomic.rs

@@ -20,7 +20,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
         intrinsic_name: &str,
         args: &[OpTy<'tcx, Provenance>],
         dest: &MPlaceTy<'tcx, Provenance>,
-    ) -> InterpResult<'tcx, bool> {
+    ) -> InterpResult<'tcx, EmulateItemResult> {
         let this = self.eval_context_mut();
 
         let intrinsic_structure: Vec<_> = intrinsic_name.split('_').collect();
@@ -114,9 +114,9 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                 this.atomic_rmw_op(args, dest, AtomicOp::Max, rw_ord(ord)?)?;
             }
 
-            _ => return Ok(false),
+            _ => return Ok(EmulateItemResult::NotSupported),
         }
-        Ok(true)
+        Ok(EmulateItemResult::NeedsJumping)
     }
 }
 

src/tools/miri/src/shims/intrinsics/mod.rs

@@ -10,8 +10,8 @@ use rustc_middle::{
     mir,
     ty::{self, FloatTy},
 };
-use rustc_target::abi::Size;
 use rustc_span::{sym, Symbol};
+use rustc_target::abi::Size;
 
 use crate::*;
 use atomic::EvalContextExt as _;
@@ -37,52 +37,39 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
         let intrinsic_name = this.tcx.item_name(instance.def_id());
         let intrinsic_name = intrinsic_name.as_str();
 
-        // Handle intrinsics without return place.
+        match this.emulate_intrinsic_by_name(intrinsic_name, instance.args, args, dest, ret)? {
-        match intrinsic_name {
+            EmulateItemResult::NotSupported => {
-            "abort" => {
-                throw_machine_stop!(TerminationInfo::Abort(
-                    "the program aborted execution".to_owned()
-                ))
-            }
-            _ => {}
-        }
-
-        // All remaining supported intrinsics have a return place.
-        let ret = match ret {
-            // FIXME: add fallback body support once we actually have a diverging intrinsic with a fallback body
-            None => throw_unsup_format!("unimplemented (diverging) intrinsic: `{intrinsic_name}`"),
-            Some(p) => p,
-        };
-
-        // Some intrinsics are special and need the "ret".
-        match intrinsic_name {
-            "catch_unwind" => {
-                this.handle_catch_unwind(args, dest, ret)?;
-                return Ok(None);
-            }
-            _ => {}
-        }
-
-        // The rest jumps to `ret` immediately.
-        if !this.emulate_intrinsic_by_name(intrinsic_name, instance.args, args, dest)? {
                 // We haven't handled the intrinsic, let's see if we can use a fallback body.
                 if this.tcx.intrinsic(instance.def_id()).unwrap().must_be_overridden {
                     throw_unsup_format!("unimplemented intrinsic: `{intrinsic_name}`")
                 }
                 let intrinsic_fallback_checks_ub = Symbol::intern("intrinsic_fallback_checks_ub");
-            if this.tcx.get_attrs_by_path(instance.def_id(), &[sym::miri, intrinsic_fallback_checks_ub]).next().is_none() {
+                if this
-                throw_unsup_format!("miri can only use intrinsic fallback bodies that check UB. After verifying that `{intrinsic_name}` does so, add the `#[miri::intrinsic_fallback_checks_ub]` attribute to it; also ping @rust-lang/miri when you do that");
+                    .tcx
+                    .get_attrs_by_path(
+                        instance.def_id(),
+                        &[sym::miri, intrinsic_fallback_checks_ub],
+                    )
+                    .next()
+                    .is_none()
+                {
+                    throw_unsup_format!(
+                        "miri can only use intrinsic fallback bodies that check UB. After verifying that `{intrinsic_name}` does so, add the `#[miri::intrinsic_fallback_checks_ub]` attribute to it; also ping @rust-lang/miri when you do that"
+                    );
                 }
-            return Ok(Some(ty::Instance {
+                Ok(Some(ty::Instance {
                     def: ty::InstanceDef::Item(instance.def_id()),
                     args: instance.args,
                 }))
             }
-
+            EmulateItemResult::NeedsJumping => {
                 trace!("{:?}", this.dump_place(&dest.clone().into()));
-        this.go_to_block(ret);
+                this.return_to_block(ret)?;
                 Ok(None)
             }
+            EmulateItemResult::AlreadyJumped => Ok(None),
+        }
+    }
 
     /// Emulates a Miri-supported intrinsic (not supported by the core engine).
     /// Returns `Ok(true)` if the intrinsic was handled.
@@ -92,7 +79,8 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
         generic_args: ty::GenericArgsRef<'tcx>,
         args: &[OpTy<'tcx, Provenance>],
         dest: &MPlaceTy<'tcx, Provenance>,
-    ) -> InterpResult<'tcx, bool> {
+        ret: Option<mir::BasicBlock>,
+    ) -> InterpResult<'tcx, EmulateItemResult> {
         let this = self.eval_context_mut();
 
         if let Some(name) = intrinsic_name.strip_prefix("atomic_") {
@@ -103,6 +91,17 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
         }
 
         match intrinsic_name {
+            "abort" => {
+                throw_machine_stop!(TerminationInfo::Abort(
+                    "the program aborted execution".to_owned()
+                ));
+            }
+            "catch_unwind" => {
+                this.handle_catch_unwind(args, dest, ret)?;
+                // THis pushed a stack frame, don't jump to `ret`.
+                return Ok(EmulateItemResult::AlreadyJumped);
+            }
+
             // Raw memory accesses
             "volatile_load" => {
                 let [place] = check_arg_count(args)?;
@@ -426,9 +425,9 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                 throw_machine_stop!(TerminationInfo::Abort(format!("trace/breakpoint trap")))
             }
 
-            _ => return Ok(false),
+            _ => return Ok(EmulateItemResult::NotSupported),
         }
 
-        Ok(true)
+        Ok(EmulateItemResult::NeedsJumping)
     }
 }

src/tools/miri/src/shims/intrinsics/simd.rs

@@ -23,7 +23,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
         generic_args: ty::GenericArgsRef<'tcx>,
         args: &[OpTy<'tcx, Provenance>],
         dest: &MPlaceTy<'tcx, Provenance>,
-    ) -> InterpResult<'tcx, bool> {
+    ) -> InterpResult<'tcx, EmulateItemResult> {
         let this = self.eval_context_mut();
         match intrinsic_name {
             #[rustfmt::skip]
@@ -744,9 +744,9 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                 }
             }
 
-            _ => return Ok(false),
+            _ => return Ok(EmulateItemResult::NotSupported),
         }
-        Ok(true)
+        Ok(EmulateItemResult::NeedsJumping)
     }
 
     fn fminmax_op(

src/tools/miri/src/shims/mod.rs

@@ -16,3 +16,13 @@ pub mod os_str;
 pub mod panic;
 pub mod time;
 pub mod tls;
+
+/// What needs to be done after emulating an item (a shim or an intrinsic) is done.
+pub enum EmulateItemResult {
+    /// The caller is expected to jump to the return block.
+    NeedsJumping,
+    /// Jumping has already been taken care of.
+    AlreadyJumped,
+    /// The item is not supported.
+    NotSupported,
+}

src/tools/miri/src/shims/panic.rs

@@ -30,7 +30,7 @@ pub struct CatchUnwindData<'tcx> {
     /// The return place from the original call to `try`.
     dest: MPlaceTy<'tcx, Provenance>,
     /// The return block from the original call to `try`.
-    ret: mir::BasicBlock,
+    ret: Option<mir::BasicBlock>,
 }
 
 impl VisitProvenance for CatchUnwindData<'_> {
@@ -73,7 +73,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
         &mut self,
         args: &[OpTy<'tcx, Provenance>],
         dest: &MPlaceTy<'tcx, Provenance>,
-        ret: mir::BasicBlock,
+        ret: Option<mir::BasicBlock>,
     ) -> InterpResult<'tcx> {
         let this = self.eval_context_mut();
 
@@ -103,7 +103,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
             &[data.into()],
             None,
             // Directly return to caller.
-            StackPopCleanup::Goto { ret: Some(ret), unwind: mir::UnwindAction::Continue },
+            StackPopCleanup::Goto { ret, unwind: mir::UnwindAction::Continue },
         )?;
 
         // We ourselves will return `0`, eventually (will be overwritten if we catch a panic).
@@ -155,7 +155,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                 None,
                 // Directly return to caller of `try`.
                 StackPopCleanup::Goto {
-                    ret: Some(catch_unwind.ret),
+                    ret: catch_unwind.ret,
                     unwind: mir::UnwindAction::Continue,
                 },
             )?;

src/tools/miri/src/shims/unix/foreign_items.rs

@@ -9,7 +9,6 @@ use rustc_target::spec::abi::Abi;
 use crate::shims::alloc::EvalContextExt as _;
 use crate::shims::unix::*;
 use crate::*;
-use shims::foreign_items::EmulateForeignItemResult;
 
 use shims::unix::freebsd::foreign_items as freebsd;
 use shims::unix::linux::foreign_items as linux;
@@ -43,7 +42,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
         abi: Abi,
         args: &[OpTy<'tcx, Provenance>],
         dest: &MPlaceTy<'tcx, Provenance>,
-    ) -> InterpResult<'tcx, EmulateForeignItemResult> {
+    ) -> InterpResult<'tcx, EmulateItemResult> {
         let this = self.eval_context_mut();
 
         // See `fn emulate_foreign_item_inner` in `shims/foreign_items.rs` for the general pattern.
@@ -750,11 +749,11 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                     "freebsd" => freebsd::EvalContextExt::emulate_foreign_item_inner(this, link_name, abi, args, dest),
                     "linux" => linux::EvalContextExt::emulate_foreign_item_inner(this, link_name, abi, args, dest),
                     "macos" => macos::EvalContextExt::emulate_foreign_item_inner(this, link_name, abi, args, dest),
-                    _ => Ok(EmulateForeignItemResult::NotSupported),
+                    _ => Ok(EmulateItemResult::NotSupported),
                 };
             }
         };
 
-        Ok(EmulateForeignItemResult::NeedsJumping)
+        Ok(EmulateItemResult::NeedsJumping)
     }
 }

src/tools/miri/src/shims/unix/freebsd/foreign_items.rs

@@ -3,7 +3,6 @@ use rustc_target::spec::abi::Abi;
 
 use crate::shims::unix::*;
 use crate::*;
-use shims::foreign_items::EmulateForeignItemResult;
 
 pub fn is_dyn_sym(_name: &str) -> bool {
     false
@@ -17,7 +16,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
         abi: Abi,
         args: &[OpTy<'tcx, Provenance>],
         dest: &MPlaceTy<'tcx, Provenance>,
-    ) -> InterpResult<'tcx, EmulateForeignItemResult> {
+    ) -> InterpResult<'tcx, EmulateItemResult> {
         let this = self.eval_context_mut();
         match link_name.as_str() {
             // Threading
@@ -97,8 +96,8 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                 this.write_scalar(errno_place.to_ref(this).to_scalar(), dest)?;
             }
 
-            _ => return Ok(EmulateForeignItemResult::NotSupported),
+            _ => return Ok(EmulateItemResult::NotSupported),
         }
-        Ok(EmulateForeignItemResult::NeedsJumping)
+        Ok(EmulateItemResult::NeedsJumping)
     }
 }

src/tools/miri/src/shims/unix/linux/foreign_items.rs

@@ -5,7 +5,6 @@ use crate::machine::SIGRTMAX;
 use crate::machine::SIGRTMIN;
 use crate::shims::unix::*;
 use crate::*;
-use shims::foreign_items::EmulateForeignItemResult;
 use shims::unix::linux::epoll::EvalContextExt as _;
 use shims::unix::linux::eventfd::EvalContextExt as _;
 use shims::unix::linux::mem::EvalContextExt as _;
@@ -23,7 +22,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
         abi: Abi,
         args: &[OpTy<'tcx, Provenance>],
         dest: &MPlaceTy<'tcx, Provenance>,
-    ) -> InterpResult<'tcx, EmulateForeignItemResult> {
+    ) -> InterpResult<'tcx, EmulateItemResult> {
         let this = self.eval_context_mut();
 
         // See `fn emulate_foreign_item_inner` in `shims/foreign_items.rs` for the general pattern.
@@ -156,7 +155,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                     }
                     id => {
                         this.handle_unsupported(format!("can't execute syscall with ID {id}"))?;
-                        return Ok(EmulateForeignItemResult::AlreadyJumped);
+                        return Ok(EmulateItemResult::AlreadyJumped);
                     }
                 }
             }
@@ -204,10 +203,10 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                 this.write_null(dest)?;
             }
 
-            _ => return Ok(EmulateForeignItemResult::NotSupported),
+            _ => return Ok(EmulateItemResult::NotSupported),
         };
 
-        Ok(EmulateForeignItemResult::NeedsJumping)
+        Ok(EmulateItemResult::NeedsJumping)
     }
 }
 

src/tools/miri/src/shims/unix/macos/foreign_items.rs

@@ -3,7 +3,6 @@ use rustc_target::spec::abi::Abi;
 
 use crate::shims::unix::*;
 use crate::*;
-use shims::foreign_items::EmulateForeignItemResult;
 
 pub fn is_dyn_sym(_name: &str) -> bool {
     false
@@ -17,7 +16,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
         abi: Abi,
         args: &[OpTy<'tcx, Provenance>],
         dest: &MPlaceTy<'tcx, Provenance>,
-    ) -> InterpResult<'tcx, EmulateForeignItemResult> {
+    ) -> InterpResult<'tcx, EmulateItemResult> {
         let this = self.eval_context_mut();
 
         // See `fn emulate_foreign_item_inner` in `shims/foreign_items.rs` for the general pattern.
@@ -175,9 +174,9 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                 this.write_scalar(res, dest)?;
             }
 
-            _ => return Ok(EmulateForeignItemResult::NotSupported),
+            _ => return Ok(EmulateItemResult::NotSupported),
         };
 
-        Ok(EmulateForeignItemResult::NeedsJumping)
+        Ok(EmulateItemResult::NeedsJumping)
     }
 }

src/tools/miri/src/shims/windows/foreign_items.rs

@@ -12,7 +12,6 @@ use crate::shims::alloc::EvalContextExt as _;
 use crate::shims::os_str::bytes_to_os_str;
 use crate::shims::windows::*;
 use crate::*;
-use shims::foreign_items::EmulateForeignItemResult;
 use shims::windows::handle::{Handle, PseudoHandle};
 
 fn is_dyn_sym(name: &str) -> bool {
@@ -86,7 +85,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
         abi: Abi,
         args: &[OpTy<'tcx, Provenance>],
         dest: &MPlaceTy<'tcx, Provenance>,
-    ) -> InterpResult<'tcx, EmulateForeignItemResult> {
+    ) -> InterpResult<'tcx, EmulateItemResult> {
         let this = self.eval_context_mut();
 
         // See `fn emulate_foreign_item_inner` in `shims/foreign_items.rs` for the general pattern.
@@ -721,9 +720,9 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                 this.write_null(dest)?;
             }
 
-            _ => return Ok(EmulateForeignItemResult::NotSupported),
+            _ => return Ok(EmulateItemResult::NotSupported),
         }
 
-        Ok(EmulateForeignItemResult::NeedsJumping)
+        Ok(EmulateItemResult::NeedsJumping)
     }
 }

src/tools/miri/src/shims/x86/aesni.rs

@@ -4,7 +4,6 @@ use rustc_span::Symbol;
 use rustc_target::spec::abi::Abi;
 
 use crate::*;
-use shims::foreign_items::EmulateForeignItemResult;
 
 impl<'mir, 'tcx: 'mir> EvalContextExt<'mir, 'tcx> for crate::MiriInterpCx<'mir, 'tcx> {}
 pub(super) trait EvalContextExt<'mir, 'tcx: 'mir>:
@@ -16,7 +15,7 @@ pub(super) trait EvalContextExt<'mir, 'tcx: 'mir>:
         abi: Abi,
         args: &[OpTy<'tcx, Provenance>],
         dest: &MPlaceTy<'tcx, Provenance>,
-    ) -> InterpResult<'tcx, EmulateForeignItemResult> {
+    ) -> InterpResult<'tcx, EmulateItemResult> {
         let this = self.eval_context_mut();
         this.expect_target_feature_for_intrinsic(link_name, "aes")?;
         // Prefix should have already been checked.
@@ -126,9 +125,9 @@ pub(super) trait EvalContextExt<'mir, 'tcx: 'mir>:
             }
             // TODO: Implement the `llvm.x86.aesni.aeskeygenassist` when possible
             // with an external crate.
-            _ => return Ok(EmulateForeignItemResult::NotSupported),
+            _ => return Ok(EmulateItemResult::NotSupported),
         }
-        Ok(EmulateForeignItemResult::NeedsJumping)
+        Ok(EmulateItemResult::NeedsJumping)
     }
 }
 

src/tools/miri/src/shims/x86/avx.rs

@@ -11,7 +11,6 @@ use super::{
     FloatBinOp, FloatUnaryOp,
 };
 use crate::*;
-use shims::foreign_items::EmulateForeignItemResult;
 
 impl<'mir, 'tcx: 'mir> EvalContextExt<'mir, 'tcx> for crate::MiriInterpCx<'mir, 'tcx> {}
 pub(super) trait EvalContextExt<'mir, 'tcx: 'mir>:
@@ -23,7 +22,7 @@ pub(super) trait EvalContextExt<'mir, 'tcx: 'mir>:
         abi: Abi,
         args: &[OpTy<'tcx, Provenance>],
         dest: &MPlaceTy<'tcx, Provenance>,
-    ) -> InterpResult<'tcx, EmulateForeignItemResult> {
+    ) -> InterpResult<'tcx, EmulateItemResult> {
         let this = self.eval_context_mut();
         this.expect_target_feature_for_intrinsic(link_name, "avx")?;
         // Prefix should have already been checked.
@@ -343,8 +342,8 @@ pub(super) trait EvalContextExt<'mir, 'tcx: 'mir>:
 
                 this.write_scalar(Scalar::from_i32(res.into()), dest)?;
             }
-            _ => return Ok(EmulateForeignItemResult::NotSupported),
+            _ => return Ok(EmulateItemResult::NotSupported),
         }
-        Ok(EmulateForeignItemResult::NeedsJumping)
+        Ok(EmulateItemResult::NeedsJumping)
     }
 }

src/tools/miri/src/shims/x86/avx2.rs

@@ -9,7 +9,6 @@ use super::{
     packuswb, pmulhrsw, psign, shift_simd_by_scalar, shift_simd_by_simd, ShiftOp,
 };
 use crate::*;
-use shims::foreign_items::EmulateForeignItemResult;
 
 impl<'mir, 'tcx: 'mir> EvalContextExt<'mir, 'tcx> for crate::MiriInterpCx<'mir, 'tcx> {}
 pub(super) trait EvalContextExt<'mir, 'tcx: 'mir>:
@@ -21,7 +20,7 @@ pub(super) trait EvalContextExt<'mir, 'tcx: 'mir>:
         abi: Abi,
         args: &[OpTy<'tcx, Provenance>],
         dest: &MPlaceTy<'tcx, Provenance>,
-    ) -> InterpResult<'tcx, EmulateForeignItemResult> {
+    ) -> InterpResult<'tcx, EmulateItemResult> {
         let this = self.eval_context_mut();
         this.expect_target_feature_for_intrinsic(link_name, "avx2")?;
         // Prefix should have already been checked.
@@ -437,8 +436,8 @@ pub(super) trait EvalContextExt<'mir, 'tcx: 'mir>:
 
                 shift_simd_by_simd(this, left, right, which, dest)?;
             }
-            _ => return Ok(EmulateForeignItemResult::NotSupported),
+            _ => return Ok(EmulateItemResult::NotSupported),
         }
-        Ok(EmulateForeignItemResult::NeedsJumping)
+        Ok(EmulateItemResult::NeedsJumping)
     }
 }

src/tools/miri/src/shims/x86/mod.rs

@@ -10,7 +10,6 @@ use rustc_target::spec::abi::Abi;
 
 use crate::*;
 use helpers::bool_to_simd_element;
-use shims::foreign_items::EmulateForeignItemResult;
 
 mod aesni;
 mod avx;
@@ -31,7 +30,7 @@ pub(super) trait EvalContextExt<'mir, 'tcx: 'mir>:
         abi: Abi,
         args: &[OpTy<'tcx, Provenance>],
         dest: &MPlaceTy<'tcx, Provenance>,
-    ) -> InterpResult<'tcx, EmulateForeignItemResult> {
+    ) -> InterpResult<'tcx, EmulateItemResult> {
         let this = self.eval_context_mut();
         // Prefix should have already been checked.
         let unprefixed_name = link_name.as_str().strip_prefix("llvm.x86.").unwrap();
@@ -43,7 +42,7 @@ pub(super) trait EvalContextExt<'mir, 'tcx: 'mir>:
             // https://www.intel.com/content/www/us/en/docs/cpp-compiler/developer-guide-reference/2021-8/addcarry-u32-addcarry-u64.html
             "addcarry.32" | "addcarry.64" => {
                 if unprefixed_name == "addcarry.64" && this.tcx.sess.target.arch != "x86_64" {
-                    return Ok(EmulateForeignItemResult::NotSupported);
+                    return Ok(EmulateItemResult::NotSupported);
                 }
 
                 let [c_in, a, b] = this.check_shim(abi, Abi::Unadjusted, link_name, args)?;
@@ -69,7 +68,7 @@ pub(super) trait EvalContextExt<'mir, 'tcx: 'mir>:
             // https://www.intel.com/content/www/us/en/docs/cpp-compiler/developer-guide-reference/2021-8/subborrow-u32-subborrow-u64.html
             "subborrow.32" | "subborrow.64" => {
                 if unprefixed_name == "subborrow.64" && this.tcx.sess.target.arch != "x86_64" {
-                    return Ok(EmulateForeignItemResult::NotSupported);
+                    return Ok(EmulateItemResult::NotSupported);
                 }
 
                 let [b_in, a, b] = this.check_shim(abi, Abi::Unadjusted, link_name, args)?;
@@ -143,9 +142,9 @@ pub(super) trait EvalContextExt<'mir, 'tcx: 'mir>:
                 );
             }
 
-            _ => return Ok(EmulateForeignItemResult::NotSupported),
+            _ => return Ok(EmulateItemResult::NotSupported),
         }
-        Ok(EmulateForeignItemResult::NeedsJumping)
+        Ok(EmulateItemResult::NeedsJumping)
     }
 }
 

src/tools/miri/src/shims/x86/sse.rs

@@ -8,7 +8,6 @@ use super::{
     FloatUnaryOp,
 };
 use crate::*;
-use shims::foreign_items::EmulateForeignItemResult;
 
 impl<'mir, 'tcx: 'mir> EvalContextExt<'mir, 'tcx> for crate::MiriInterpCx<'mir, 'tcx> {}
 pub(super) trait EvalContextExt<'mir, 'tcx: 'mir>:
@@ -20,7 +19,7 @@ pub(super) trait EvalContextExt<'mir, 'tcx: 'mir>:
         abi: Abi,
         args: &[OpTy<'tcx, Provenance>],
         dest: &MPlaceTy<'tcx, Provenance>,
-    ) -> InterpResult<'tcx, EmulateForeignItemResult> {
+    ) -> InterpResult<'tcx, EmulateItemResult> {
         let this = self.eval_context_mut();
         this.expect_target_feature_for_intrinsic(link_name, "sse")?;
         // Prefix should have already been checked.
@@ -211,8 +210,8 @@ pub(super) trait EvalContextExt<'mir, 'tcx: 'mir>:
                     this.copy_op(&this.project_index(&left, i)?, &this.project_index(&dest, i)?)?;
                 }
             }
-            _ => return Ok(EmulateForeignItemResult::NotSupported),
+            _ => return Ok(EmulateItemResult::NotSupported),
         }
-        Ok(EmulateForeignItemResult::NeedsJumping)
+        Ok(EmulateItemResult::NeedsJumping)
     }
 }

src/tools/miri/src/shims/x86/sse2.rs

@@ -7,7 +7,6 @@ use super::{
     packuswb, shift_simd_by_scalar, FloatBinOp, ShiftOp,
 };
 use crate::*;
-use shims::foreign_items::EmulateForeignItemResult;
 
 impl<'mir, 'tcx: 'mir> EvalContextExt<'mir, 'tcx> for crate::MiriInterpCx<'mir, 'tcx> {}
 pub(super) trait EvalContextExt<'mir, 'tcx: 'mir>:
@@ -19,7 +18,7 @@ pub(super) trait EvalContextExt<'mir, 'tcx: 'mir>:
         abi: Abi,
         args: &[OpTy<'tcx, Provenance>],
         dest: &MPlaceTy<'tcx, Provenance>,
-    ) -> InterpResult<'tcx, EmulateForeignItemResult> {
+    ) -> InterpResult<'tcx, EmulateItemResult> {
         let this = self.eval_context_mut();
         this.expect_target_feature_for_intrinsic(link_name, "sse2")?;
         // Prefix should have already been checked.
@@ -387,8 +386,8 @@ pub(super) trait EvalContextExt<'mir, 'tcx: 'mir>:
                     this.copy_op(&this.project_index(&left, i)?, &this.project_index(&dest, i)?)?;
                 }
             }
-            _ => return Ok(EmulateForeignItemResult::NotSupported),
+            _ => return Ok(EmulateItemResult::NotSupported),
         }
-        Ok(EmulateForeignItemResult::NeedsJumping)
+        Ok(EmulateItemResult::NeedsJumping)
     }
 }

src/tools/miri/src/shims/x86/sse3.rs

@@ -4,7 +4,6 @@ use rustc_target::spec::abi::Abi;
 
 use super::horizontal_bin_op;
 use crate::*;
-use shims::foreign_items::EmulateForeignItemResult;
 
 impl<'mir, 'tcx: 'mir> EvalContextExt<'mir, 'tcx> for crate::MiriInterpCx<'mir, 'tcx> {}
 pub(super) trait EvalContextExt<'mir, 'tcx: 'mir>:
@@ -16,7 +15,7 @@ pub(super) trait EvalContextExt<'mir, 'tcx: 'mir>:
         abi: Abi,
         args: &[OpTy<'tcx, Provenance>],
         dest: &MPlaceTy<'tcx, Provenance>,
-    ) -> InterpResult<'tcx, EmulateForeignItemResult> {
+    ) -> InterpResult<'tcx, EmulateItemResult> {
         let this = self.eval_context_mut();
         this.expect_target_feature_for_intrinsic(link_name, "sse3")?;
         // Prefix should have already been checked.
@@ -50,8 +49,8 @@ pub(super) trait EvalContextExt<'mir, 'tcx: 'mir>:
 
                 this.mem_copy(src_ptr, dest.ptr(), dest.layout.size, /*nonoverlapping*/ true)?;
             }
-            _ => return Ok(EmulateForeignItemResult::NotSupported),
+            _ => return Ok(EmulateItemResult::NotSupported),
         }
-        Ok(EmulateForeignItemResult::NeedsJumping)
+        Ok(EmulateItemResult::NeedsJumping)
     }
 }

src/tools/miri/src/shims/x86/sse41.rs

@@ -3,7 +3,6 @@ use rustc_target::spec::abi::Abi;
 
 use super::{conditional_dot_product, mpsadbw, packusdw, round_all, round_first, test_bits_masked};
 use crate::*;
-use shims::foreign_items::EmulateForeignItemResult;
 
 impl<'mir, 'tcx: 'mir> EvalContextExt<'mir, 'tcx> for crate::MiriInterpCx<'mir, 'tcx> {}
 pub(super) trait EvalContextExt<'mir, 'tcx: 'mir>:
@@ -15,7 +14,7 @@ pub(super) trait EvalContextExt<'mir, 'tcx: 'mir>:
         abi: Abi,
         args: &[OpTy<'tcx, Provenance>],
         dest: &MPlaceTy<'tcx, Provenance>,
-    ) -> InterpResult<'tcx, EmulateForeignItemResult> {
+    ) -> InterpResult<'tcx, EmulateItemResult> {
         let this = self.eval_context_mut();
         this.expect_target_feature_for_intrinsic(link_name, "sse4.1")?;
         // Prefix should have already been checked.
@@ -175,8 +174,8 @@ pub(super) trait EvalContextExt<'mir, 'tcx: 'mir>:
 
                 this.write_scalar(Scalar::from_i32(res.into()), dest)?;
             }
-            _ => return Ok(EmulateForeignItemResult::NotSupported),
+            _ => return Ok(EmulateItemResult::NotSupported),
         }
-        Ok(EmulateForeignItemResult::NeedsJumping)
+        Ok(EmulateItemResult::NeedsJumping)
     }
 }

src/tools/miri/src/shims/x86/ssse3.rs

@@ -4,7 +4,6 @@ use rustc_target::spec::abi::Abi;
 
 use super::{horizontal_bin_op, int_abs, pmulhrsw, psign};
 use crate::*;
-use shims::foreign_items::EmulateForeignItemResult;
 
 impl<'mir, 'tcx: 'mir> EvalContextExt<'mir, 'tcx> for crate::MiriInterpCx<'mir, 'tcx> {}
 pub(super) trait EvalContextExt<'mir, 'tcx: 'mir>:
@@ -16,7 +15,7 @@ pub(super) trait EvalContextExt<'mir, 'tcx: 'mir>:
         abi: Abi,
         args: &[OpTy<'tcx, Provenance>],
         dest: &MPlaceTy<'tcx, Provenance>,
-    ) -> InterpResult<'tcx, EmulateForeignItemResult> {
+    ) -> InterpResult<'tcx, EmulateItemResult> {
         let this = self.eval_context_mut();
         this.expect_target_feature_for_intrinsic(link_name, "ssse3")?;
         // Prefix should have already been checked.
@@ -136,8 +135,8 @@ pub(super) trait EvalContextExt<'mir, 'tcx: 'mir>:
 
                 psign(this, left, right, dest)?;
             }
-            _ => return Ok(EmulateForeignItemResult::NotSupported),
+            _ => return Ok(EmulateItemResult::NotSupported),
         }
-        Ok(EmulateForeignItemResult::NeedsJumping)
+        Ok(EmulateItemResult::NeedsJumping)
     }
 }