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

compiler/rustc_const_eval/src/const_eval/error.rs

@@ -11,7 +11,8 @@ use rustc_span::{Span, Symbol};
 use super::CompileTimeMachine;
 use crate::errors::{self, FrameNote, ReportErrorExt};
 use crate::interpret::{
-    ErrorHandled, Frame, InterpError, InterpErrorInfo, MachineStopType, err_inval, err_machine_stop,
+    ErrorHandled, Frame, InterpErrorInfo, InterpErrorKind, MachineStopType, err_inval,
+    err_machine_stop,
 };
 
 /// The CTFE machine has some custom error kinds.
@@ -57,7 +58,7 @@ impl MachineStopType for ConstEvalErrKind {
     }
 }
 
-/// The errors become [`InterpError::MachineStop`] when being raised.
+/// The errors become [`InterpErrorKind::MachineStop`] when being raised.
 impl<'tcx> Into<InterpErrorInfo<'tcx>> for ConstEvalErrKind {
     fn into(self) -> InterpErrorInfo<'tcx> {
         err_machine_stop!(self).into()
@@ -124,7 +125,7 @@ pub fn get_span_and_frames<'tcx>(
 /// `get_span_and_frames`.
 pub(super) fn report<'tcx, C, F, E>(
     tcx: TyCtxt<'tcx>,
-    error: InterpError<'tcx>,
+    error: InterpErrorKind<'tcx>,
     span: Span,
     get_span_and_frames: C,
     mk: F,

compiler/rustc_const_eval/src/const_eval/eval_queries.rs

@@ -18,7 +18,7 @@ use tracing::{debug, instrument, trace};
 use super::{CanAccessMutGlobal, CompileTimeInterpCx, CompileTimeMachine};
 use crate::const_eval::CheckAlignment;
 use crate::interpret::{
-    CtfeValidationMode, GlobalId, Immediate, InternKind, InternResult, InterpCx, InterpError,
+    CtfeValidationMode, GlobalId, Immediate, InternKind, InternResult, InterpCx, InterpErrorKind,
     InterpResult, MPlaceTy, MemoryKind, OpTy, RefTracking, StackPopCleanup, create_static_alloc,
     eval_nullary_intrinsic, intern_const_alloc_recursive, interp_ok, throw_exhaust,
 };
@@ -463,7 +463,7 @@ fn report_validation_error<'tcx>(
     error: InterpErrorInfo<'tcx>,
     alloc_id: AllocId,
 ) -> ErrorHandled {
-    if !matches!(error.kind(), InterpError::UndefinedBehavior(_)) {
+    if !matches!(error.kind(), InterpErrorKind::UndefinedBehavior(_)) {
         // Some other error happened during validation, e.g. an unsupported operation.
         return report_eval_error(ecx, cid, error);
     }

compiler/rustc_const_eval/src/errors.rs

@@ -9,7 +9,7 @@ use rustc_errors::{
 use rustc_hir::ConstContext;
 use rustc_macros::{Diagnostic, LintDiagnostic, Subdiagnostic};
 use rustc_middle::mir::interpret::{
-    CheckInAllocMsg, CtfeProvenance, ExpectedKind, InterpError, InvalidMetaKind,
+    CheckInAllocMsg, CtfeProvenance, ExpectedKind, InterpErrorKind, InvalidMetaKind,
     InvalidProgramInfo, Misalignment, Pointer, PointerKind, ResourceExhaustionInfo,
     UndefinedBehaviorInfo, UnsupportedOpInfo, ValidationErrorInfo,
 };
@@ -835,23 +835,23 @@ impl ReportErrorExt for UnsupportedOpInfo {
     }
 }
 
-impl<'tcx> ReportErrorExt for InterpError<'tcx> {
+impl<'tcx> ReportErrorExt for InterpErrorKind<'tcx> {
     fn diagnostic_message(&self) -> DiagMessage {
         match self {
-            InterpError::UndefinedBehavior(ub) => ub.diagnostic_message(),
-            InterpError::Unsupported(e) => e.diagnostic_message(),
-            InterpError::InvalidProgram(e) => e.diagnostic_message(),
-            InterpError::ResourceExhaustion(e) => e.diagnostic_message(),
-            InterpError::MachineStop(e) => e.diagnostic_message(),
+            InterpErrorKind::UndefinedBehavior(ub) => ub.diagnostic_message(),
+            InterpErrorKind::Unsupported(e) => e.diagnostic_message(),
+            InterpErrorKind::InvalidProgram(e) => e.diagnostic_message(),
+            InterpErrorKind::ResourceExhaustion(e) => e.diagnostic_message(),
+            InterpErrorKind::MachineStop(e) => e.diagnostic_message(),
         }
     }
     fn add_args<G: EmissionGuarantee>(self, diag: &mut Diag<'_, G>) {
         match self {
-            InterpError::UndefinedBehavior(ub) => ub.add_args(diag),
-            InterpError::Unsupported(e) => e.add_args(diag),
-            InterpError::InvalidProgram(e) => e.add_args(diag),
-            InterpError::ResourceExhaustion(e) => e.add_args(diag),
-            InterpError::MachineStop(e) => e.add_args(&mut |name, value| {
+            InterpErrorKind::UndefinedBehavior(ub) => ub.add_args(diag),
+            InterpErrorKind::Unsupported(e) => e.add_args(diag),
+            InterpErrorKind::InvalidProgram(e) => e.add_args(diag),
+            InterpErrorKind::ResourceExhaustion(e) => e.add_args(diag),
+            InterpErrorKind::MachineStop(e) => e.add_args(&mut |name, value| {
                 diag.arg(name, value);
             }),
         }

compiler/rustc_const_eval/src/interpret/call.rs

@@ -471,7 +471,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
             // Don't forget to mark "initially live" locals as live.
             self.storage_live_for_always_live_locals()?;
         };
-        res.inspect_err(|_| {
+        res.inspect_err_kind(|_| {
             // Don't show the incomplete stack frame in the error stacktrace.
             self.stack_mut().pop();
         })

compiler/rustc_const_eval/src/interpret/eval_context.rs

@@ -19,7 +19,7 @@ use rustc_trait_selection::traits::ObligationCtxt;
 use tracing::{debug, instrument, trace};
 
 use super::{
-    Frame, FrameInfo, GlobalId, InterpError, InterpErrorInfo, InterpResult, MPlaceTy, Machine,
+    Frame, FrameInfo, GlobalId, InterpErrorInfo, InterpErrorKind, InterpResult, MPlaceTy, Machine,
     MemPlaceMeta, Memory, OpTy, Place, PlaceTy, PointerArithmetic, Projectable, Provenance,
     err_inval, interp_ok, throw_inval, throw_ub, throw_ub_custom,
 };
@@ -73,7 +73,7 @@ where
 }
 
 impl<'tcx, M: Machine<'tcx>> LayoutOfHelpers<'tcx> for InterpCx<'tcx, M> {
-    type LayoutOfResult = Result<TyAndLayout<'tcx>, InterpError<'tcx>>;
+    type LayoutOfResult = Result<TyAndLayout<'tcx>, InterpErrorKind<'tcx>>;
 
     #[inline]
     fn layout_tcx_at_span(&self) -> Span {
@@ -82,20 +82,25 @@ impl<'tcx, M: Machine<'tcx>> LayoutOfHelpers<'tcx> for InterpCx<'tcx, M> {
     }
 
     #[inline]
-    fn handle_layout_err(&self, err: LayoutError<'tcx>, _: Span, _: Ty<'tcx>) -> InterpError<'tcx> {
+    fn handle_layout_err(
+        &self,
+        err: LayoutError<'tcx>,
+        _: Span,
+        _: Ty<'tcx>,
+    ) -> InterpErrorKind<'tcx> {
         err_inval!(Layout(err))
     }
 }
 
 impl<'tcx, M: Machine<'tcx>> FnAbiOfHelpers<'tcx> for InterpCx<'tcx, M> {
-    type FnAbiOfResult = Result<&'tcx FnAbi<'tcx, Ty<'tcx>>, InterpError<'tcx>>;
+    type FnAbiOfResult = Result<&'tcx FnAbi<'tcx, Ty<'tcx>>, InterpErrorKind<'tcx>>;
 
     fn handle_fn_abi_err(
         &self,
         err: FnAbiError<'tcx>,
         _span: Span,
         _fn_abi_request: FnAbiRequest<'tcx>,
-    ) -> InterpError<'tcx> {
+    ) -> InterpErrorKind<'tcx> {
         match err {
             FnAbiError::Layout(err) => err_inval!(Layout(err)),
             FnAbiError::AdjustForForeignAbi(err) => {

compiler/rustc_const_eval/src/interpret/intrinsics.rs

@@ -324,13 +324,12 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
                     dist.checked_neg().unwrap(), // i64::MIN is impossible as no allocation can be that large
                     CheckInAllocMsg::OffsetFromTest,
                 )
-                .map_err(|_| {
+                .map_err_kind(|_| {
                     // Make the error more specific.
                     err_ub_custom!(
                         fluent::const_eval_offset_from_different_allocations,
                         name = intrinsic_name,
                     )
-                    .into()
                 })?;
 
                 // Perform division by size to compute return value.

compiler/rustc_const_eval/src/interpret/validity.rs

@@ -17,8 +17,8 @@ use rustc_hir as hir;
 use rustc_middle::bug;
 use rustc_middle::mir::interpret::ValidationErrorKind::{self, *};
 use rustc_middle::mir::interpret::{
-    ExpectedKind, InterpError, InterpErrorInfo, InvalidMetaKind, Misalignment, PointerKind,
-    Provenance, UnsupportedOpInfo, ValidationErrorInfo, alloc_range, interp_ok,
+    ExpectedKind, InterpErrorKind, InvalidMetaKind, Misalignment, PointerKind, Provenance,
+    UnsupportedOpInfo, ValidationErrorInfo, alloc_range, interp_ok,
 };
 use rustc_middle::ty::layout::{LayoutCx, LayoutOf, TyAndLayout};
 use rustc_middle::ty::{self, Ty};
@@ -37,8 +37,8 @@ use super::{
 
 // for the validation errors
 #[rustfmt::skip]
-use super::InterpError::UndefinedBehavior as Ub;
-use super::InterpError::Unsupported as Unsup;
+use super::InterpErrorKind::UndefinedBehavior as Ub;
+use super::InterpErrorKind::Unsupported as Unsup;
 use super::UndefinedBehaviorInfo::*;
 use super::UnsupportedOpInfo::*;
 
@@ -97,20 +97,19 @@ macro_rules! try_validation {
     ($e:expr, $where:expr,
     $( $( $p:pat_param )|+ => $kind: expr ),+ $(,)?
     ) => {{
-        $e.map_err(|e| {
+        $e.map_err_kind(|e| {
             // We catch the error and turn it into a validation failure. We are okay with
             // allocation here as this can only slow down builds that fail anyway.
-            let (kind, backtrace) = e.into_parts();
-            match kind {
+            match e {
                 $(
                     $($p)|+ => {
                         err_validation_failure!(
                             $where,
                             $kind
-                        ).into()
+                        )
                     }
                 ),+,
-                _ => InterpErrorInfo::from_parts(kind, backtrace),
+                e => e,
             }
         })?
     }};
@@ -1230,11 +1229,10 @@ impl<'rt, 'tcx, M: Machine<'tcx>> ValueVisitor<'tcx, M> for ValidityVisitor<'rt,
                 // No need for an alignment check here, this is not an actual memory access.
                 let alloc = self.ecx.get_ptr_alloc(mplace.ptr(), size)?.expect("we already excluded size 0");
 
-                alloc.get_bytes_strip_provenance().map_err(|err| {
+                alloc.get_bytes_strip_provenance().map_err_kind(|kind| {
                     // Some error happened, try to provide a more detailed description.
                     // For some errors we might be able to provide extra information.
                     // (This custom logic does not fit the `try_validation!` macro.)
-                    let (kind, backtrace) = err.into_parts();
                     match kind {
                         Ub(InvalidUninitBytes(Some((_alloc_id, access)))) | Unsup(ReadPointerAsInt(Some((_alloc_id, access)))) => {
                             // Some byte was uninitialized, determine which
@@ -1247,14 +1245,14 @@ impl<'rt, 'tcx, M: Machine<'tcx>> ValueVisitor<'tcx, M> for ValidityVisitor<'rt,
                             self.path.push(PathElem::ArrayElem(i));
 
                             if matches!(kind, Ub(InvalidUninitBytes(_))) {
-                                err_validation_failure!(self.path, Uninit { expected }).into()
+                                err_validation_failure!(self.path, Uninit { expected })
                             } else {
-                                err_validation_failure!(self.path, PointerAsInt { expected }).into()
+                                err_validation_failure!(self.path, PointerAsInt { expected })
                             }
                         }
 
                         // Propagate upwards (that will also check for unexpected errors).
-                        _ => return InterpErrorInfo::from_parts(kind, backtrace),
+                        err => err,
                     }
                 })?;
 
@@ -1368,12 +1366,12 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
             v.reset_padding(val)?;
             interp_ok(())
         })
-        .map_err(|err| {
+        .map_err_info(|err| {
             if !matches!(
                 err.kind(),
                 err_ub!(ValidationError { .. })
-                    | InterpError::InvalidProgram(_)
-                    | InterpError::Unsupported(UnsupportedOpInfo::ExternTypeField)
+                    | InterpErrorKind::InvalidProgram(_)
+                    | InterpErrorKind::Unsupported(UnsupportedOpInfo::ExternTypeField)
             ) {
                 bug!(
                     "Unexpected error during validation: {}",

compiler/rustc_middle/src/mir/interpret/allocation.rs

@@ -18,9 +18,9 @@ use rustc_macros::{HashStable, TyDecodable, TyEncodable};
 use rustc_target::abi::{Align, HasDataLayout, Size};
 
 use super::{
-    AllocId, BadBytesAccess, CtfeProvenance, InterpError, InterpResult, Pointer, PointerArithmetic,
-    Provenance, ResourceExhaustionInfo, Scalar, ScalarSizeMismatch, UndefinedBehaviorInfo,
-    UnsupportedOpInfo, interp_ok, read_target_uint, write_target_uint,
+    AllocId, BadBytesAccess, CtfeProvenance, InterpErrorKind, InterpResult, Pointer,
+    PointerArithmetic, Provenance, ResourceExhaustionInfo, Scalar, ScalarSizeMismatch,
+    UndefinedBehaviorInfo, UnsupportedOpInfo, interp_ok, read_target_uint, write_target_uint,
 };
 use crate::ty;
 
@@ -199,22 +199,22 @@ impl From<ScalarSizeMismatch> for AllocError {
 }
 
 impl AllocError {
-    pub fn to_interp_error<'tcx>(self, alloc_id: AllocId) -> InterpError<'tcx> {
+    pub fn to_interp_error<'tcx>(self, alloc_id: AllocId) -> InterpErrorKind<'tcx> {
         use AllocError::*;
         match self {
             ScalarSizeMismatch(s) => {
-                InterpError::UndefinedBehavior(UndefinedBehaviorInfo::ScalarSizeMismatch(s))
+                InterpErrorKind::UndefinedBehavior(UndefinedBehaviorInfo::ScalarSizeMismatch(s))
             }
-            ReadPointerAsInt(info) => InterpError::Unsupported(
+            ReadPointerAsInt(info) => InterpErrorKind::Unsupported(
                 UnsupportedOpInfo::ReadPointerAsInt(info.map(|b| (alloc_id, b))),
             ),
-            OverwritePartialPointer(offset) => InterpError::Unsupported(
+            OverwritePartialPointer(offset) => InterpErrorKind::Unsupported(
                 UnsupportedOpInfo::OverwritePartialPointer(Pointer::new(alloc_id, offset)),
             ),
-            ReadPartialPointer(offset) => InterpError::Unsupported(
+            ReadPartialPointer(offset) => InterpErrorKind::Unsupported(
                 UnsupportedOpInfo::ReadPartialPointer(Pointer::new(alloc_id, offset)),
             ),
-            InvalidUninitBytes(info) => InterpError::UndefinedBehavior(
+            InvalidUninitBytes(info) => InterpErrorKind::UndefinedBehavior(
                 UndefinedBehaviorInfo::InvalidUninitBytes(info.map(|b| (alloc_id, b))),
             ),
         }
@@ -318,7 +318,7 @@ impl<Prov: Provenance, Bytes: AllocBytes> Allocation<Prov, (), Bytes> {
     pub fn try_uninit<'tcx>(size: Size, align: Align) -> InterpResult<'tcx, Self> {
         Self::uninit_inner(size, align, || {
             ty::tls::with(|tcx| tcx.dcx().delayed_bug("exhausted memory during interpretation"));
-            InterpError::ResourceExhaustion(ResourceExhaustionInfo::MemoryExhausted)
+            InterpErrorKind::ResourceExhaustion(ResourceExhaustionInfo::MemoryExhausted)
         })
         .into()
     }