Rollup merge of #131916 - RalfJung:interpret-err, r=jieyouxu

small interpreter error cleanup

- Add `InterpretResult::map_err_kind` for the common case of swapping out the error kind (while preserving the backtrace pointing to the original error source)
- Rename `InterpError` -> `InterpErrorKind` to be consistent with the `kind` field name, and make it more clear that this is not the final error type

Author: matthiaskrgr

src/borrow_tracker/stacked_borrows/diagnostics.rs

@@ -13,7 +13,7 @@ fn err_sb_ub<'tcx>(
     msg: String,
     help: Vec<String>,
     history: Option<TagHistory>,
-) -> InterpError<'tcx> {
+) -> InterpErrorKind<'tcx> {
     err_machine_stop!(TerminationInfo::StackedBorrowsUb { msg, help, history })
 }
 
@@ -376,7 +376,7 @@ impl<'history, 'ecx, 'tcx> DiagnosticCx<'history, 'ecx, 'tcx> {
 
     /// Report a descriptive error when `new` could not be granted from `derived_from`.
     #[inline(never)] // This is only called on fatal code paths
-    pub(super) fn grant_error(&self, stack: &Stack) -> InterpError<'tcx> {
+    pub(super) fn grant_error(&self, stack: &Stack) -> InterpErrorKind<'tcx> {
         let Operation::Retag(op) = &self.operation else {
             unreachable!("grant_error should only be called during a retag")
         };
@@ -402,7 +402,7 @@ impl<'history, 'ecx, 'tcx> DiagnosticCx<'history, 'ecx, 'tcx> {
 
     /// Report a descriptive error when `access` is not permitted based on `tag`.
     #[inline(never)] // This is only called on fatal code paths
-    pub(super) fn access_error(&self, stack: &Stack) -> InterpError<'tcx> {
+    pub(super) fn access_error(&self, stack: &Stack) -> InterpErrorKind<'tcx> {
         // Deallocation and retagging also do an access as part of their thing, so handle that here, too.
         let op = match &self.operation {
             Operation::Access(op) => op,
@@ -424,7 +424,7 @@ impl<'history, 'ecx, 'tcx> DiagnosticCx<'history, 'ecx, 'tcx> {
     }
 
     #[inline(never)] // This is only called on fatal code paths
-    pub(super) fn protector_error(&self, item: &Item, kind: ProtectorKind) -> InterpError<'tcx> {
+    pub(super) fn protector_error(&self, item: &Item, kind: ProtectorKind) -> InterpErrorKind<'tcx> {
         let protected = match kind {
             ProtectorKind::WeakProtector => "weakly protected",
             ProtectorKind::StrongProtector => "strongly protected",
@@ -445,7 +445,7 @@ impl<'history, 'ecx, 'tcx> DiagnosticCx<'history, 'ecx, 'tcx> {
     }
 
     #[inline(never)] // This is only called on fatal code paths
-    pub fn dealloc_error(&self, stack: &Stack) -> InterpError<'tcx> {
+    pub fn dealloc_error(&self, stack: &Stack) -> InterpErrorKind<'tcx> {
         let Operation::Dealloc(op) = &self.operation else {
             unreachable!("dealloc_error should only be called during a deallocation")
         };

src/borrow_tracker/tree_borrows/diagnostics.rs

@@ -298,7 +298,7 @@ pub(super) struct TbError<'node> {
 
 impl TbError<'_> {
     /// Produce a UB error.
-    pub fn build<'tcx>(self) -> InterpError<'tcx> {
+    pub fn build<'tcx>(self) -> InterpErrorKind<'tcx> {
         use TransitionError::*;
         let cause = self.access_cause;
         let accessed = self.accessed_info;

src/borrow_tracker/tree_borrows/tree.rs

@@ -674,7 +674,7 @@ impl<'tcx> Tree {
                             Ok(())
                         }
                     },
-                    |args: ErrHandlerArgs<'_, TransitionError>| -> InterpError<'tcx> {
+                    |args: ErrHandlerArgs<'_, TransitionError>| -> InterpErrorKind<'tcx> {
                         let ErrHandlerArgs { error_kind, conflicting_info, accessed_info } = args;
                         TbError {
                             conflicting_info,
@@ -772,7 +772,7 @@ impl<'tcx> Tree {
         let err_handler = |perms_range: Range<u64>,
                            access_cause: diagnostics::AccessCause,
                            args: ErrHandlerArgs<'_, TransitionError>|
-         -> InterpError<'tcx> {
+         -> InterpErrorKind<'tcx> {
             let ErrHandlerArgs { error_kind, conflicting_info, accessed_info } = args;
             TbError {
                 conflicting_info,

src/diagnostics.rs

@@ -214,7 +214,7 @@ pub fn report_error<'tcx>(
     ecx: &InterpCx<'tcx, MiriMachine<'tcx>>,
     e: InterpErrorInfo<'tcx>,
 ) -> Option<(i64, bool)> {
-    use InterpError::*;
+    use InterpErrorKind::*;
     use UndefinedBehaviorInfo::*;
 
     let mut msg = vec![];

src/intrinsics/simd.rs

@@ -245,17 +245,17 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
                     let val = match which {
                         Op::MirOp(mir_op) => {
                             // This does NaN adjustments.
-                            let val = this.binary_op(mir_op, &left, &right).map_err(|err| {
-                                match err.kind() {
-                                    &InterpError::UndefinedBehavior(UndefinedBehaviorInfo::ShiftOverflow { shift_amount, .. }) => {
+                            let val = this.binary_op(mir_op, &left, &right).map_err_kind(|kind| {
+                                match kind {
+                                    InterpErrorKind::UndefinedBehavior(UndefinedBehaviorInfo::ShiftOverflow { shift_amount, .. }) => {
                                         // This resets the interpreter backtrace, but it's not worth avoiding that.
                                         let shift_amount = match shift_amount {
                                             Either::Left(v) => v.to_string(),
                                             Either::Right(v) => v.to_string(),
                                         };
-                                        err_ub_format!("overflowing shift by {shift_amount} in `simd_{intrinsic_name}` in lane {i}").into()
+                                        err_ub_format!("overflowing shift by {shift_amount} in `simd_{intrinsic_name}` in lane {i}")
                                     }
-                                    _ => err
+                                    kind => kind
                                 }
                             })?;
                             if matches!(mir_op, BinOp::Eq | BinOp::Ne | BinOp::Lt | BinOp::Le | BinOp::Gt | BinOp::Ge) {

src/shims/foreign_items.rs

@@ -289,11 +289,10 @@ trait EvalContextExtPriv<'tcx>: crate::MiriInterpCxExt<'tcx> {
             "miri_get_alloc_id" => {
                 let [ptr] = this.check_shim(abi, Abi::Rust, link_name, args)?;
                 let ptr = this.read_pointer(ptr)?;
-                let (alloc_id, _, _) = this.ptr_get_alloc_id(ptr, 0).map_err(|_e| {
+                let (alloc_id, _, _) = this.ptr_get_alloc_id(ptr, 0).map_err_kind(|_e| {
                     err_machine_stop!(TerminationInfo::Abort(format!(
                         "pointer passed to `miri_get_alloc_id` must not be dangling, got {ptr:?}"
                     )))
-                    .into()
                 })?;
                 this.write_scalar(Scalar::from_u64(alloc_id.0.get()), dest)?;
             }