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|
use super::{AllocId, AllocRange, ConstAlloc, Pointer, Scalar};
use crate::mir::interpret::ConstValue;
use crate::query::TyCtxtAt;
use crate::ty::{layout, tls, Ty, ValTree};
use rustc_data_structures::sync::Lock;
use rustc_errors::{
struct_span_err, DiagnosticArgValue, DiagnosticBuilder, DiagnosticMessage, ErrorGuaranteed,
IntoDiagnosticArg,
};
use rustc_macros::HashStable;
use rustc_session::CtfeBacktrace;
use rustc_span::def_id::DefId;
use rustc_target::abi::{call, Align, Size, VariantIdx, WrappingRange};
use std::borrow::Cow;
use std::{any::Any, backtrace::Backtrace, fmt};
#[derive(Debug, Copy, Clone, PartialEq, Eq, HashStable, TyEncodable, TyDecodable)]
pub enum ErrorHandled {
/// Already reported an error for this evaluation, and the compilation is
/// *guaranteed* to fail. Warnings/lints *must not* produce `Reported`.
Reported(ReportedErrorInfo),
/// Don't emit an error, the evaluation failed because the MIR was generic
/// and the args didn't fully monomorphize it.
TooGeneric,
}
impl From<ErrorGuaranteed> for ErrorHandled {
#[inline]
fn from(error: ErrorGuaranteed) -> ErrorHandled {
ErrorHandled::Reported(error.into())
}
}
#[derive(Debug, Copy, Clone, PartialEq, Eq, HashStable, TyEncodable, TyDecodable)]
pub struct ReportedErrorInfo {
error: ErrorGuaranteed,
is_tainted_by_errors: bool,
}
impl ReportedErrorInfo {
#[inline]
pub fn tainted_by_errors(error: ErrorGuaranteed) -> ReportedErrorInfo {
ReportedErrorInfo { is_tainted_by_errors: true, error }
}
/// Returns true if evaluation failed because MIR was tainted by errors.
#[inline]
pub fn is_tainted_by_errors(self) -> bool {
self.is_tainted_by_errors
}
}
impl From<ErrorGuaranteed> for ReportedErrorInfo {
#[inline]
fn from(error: ErrorGuaranteed) -> ReportedErrorInfo {
ReportedErrorInfo { is_tainted_by_errors: false, error }
}
}
impl Into<ErrorGuaranteed> for ReportedErrorInfo {
#[inline]
fn into(self) -> ErrorGuaranteed {
self.error
}
}
TrivialTypeTraversalAndLiftImpls! { ErrorHandled }
pub type EvalToAllocationRawResult<'tcx> = Result<ConstAlloc<'tcx>, ErrorHandled>;
pub type EvalToConstValueResult<'tcx> = Result<ConstValue<'tcx>, ErrorHandled>;
pub type EvalToValTreeResult<'tcx> = Result<Option<ValTree<'tcx>>, ErrorHandled>;
pub fn struct_error<'tcx>(
tcx: TyCtxtAt<'tcx>,
msg: &str,
) -> DiagnosticBuilder<'tcx, ErrorGuaranteed> {
struct_span_err!(tcx.sess, tcx.span, E0080, "{}", msg)
}
#[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
static_assert_size!(InterpErrorInfo<'_>, 8);
/// Packages the kind of error we got from the const code interpreter
/// up with a Rust-level backtrace of where the error occurred.
/// These should always be constructed by calling `.into()` on
/// an `InterpError`. In `rustc_mir::interpret`, we have `throw_err_*`
/// macros for this.
#[derive(Debug)]
pub struct InterpErrorInfo<'tcx>(Box<InterpErrorInfoInner<'tcx>>);
#[derive(Debug)]
struct InterpErrorInfoInner<'tcx> {
kind: InterpError<'tcx>,
backtrace: InterpErrorBacktrace,
}
#[derive(Debug)]
pub struct InterpErrorBacktrace {
backtrace: Option<Box<Backtrace>>,
}
impl InterpErrorBacktrace {
pub fn new() -> InterpErrorBacktrace {
let capture_backtrace = tls::with_opt(|tcx| {
if let Some(tcx) = tcx {
*Lock::borrow(&tcx.sess.ctfe_backtrace)
} else {
CtfeBacktrace::Disabled
}
});
let backtrace = match capture_backtrace {
CtfeBacktrace::Disabled => None,
CtfeBacktrace::Capture => Some(Box::new(Backtrace::force_capture())),
CtfeBacktrace::Immediate => {
// Print it now.
let backtrace = Backtrace::force_capture();
print_backtrace(&backtrace);
None
}
};
InterpErrorBacktrace { backtrace }
}
pub fn print_backtrace(&self) {
if let Some(backtrace) = self.backtrace.as_ref() {
print_backtrace(backtrace);
}
}
}
impl<'tcx> InterpErrorInfo<'tcx> {
pub fn into_parts(self) -> (InterpError<'tcx>, InterpErrorBacktrace) {
let InterpErrorInfo(box InterpErrorInfoInner { kind, backtrace }) = self;
(kind, backtrace)
}
pub fn into_kind(self) -> InterpError<'tcx> {
let InterpErrorInfo(box InterpErrorInfoInner { kind, .. }) = self;
kind
}
#[inline]
pub fn kind(&self) -> &InterpError<'tcx> {
&self.0.kind
}
}
fn print_backtrace(backtrace: &Backtrace) {
eprintln!("\n\nAn error occurred in the MIR interpreter:\n{backtrace}");
}
impl From<ErrorGuaranteed> for InterpErrorInfo<'_> {
fn from(err: ErrorGuaranteed) -> Self {
InterpError::InvalidProgram(InvalidProgramInfo::AlreadyReported(err.into())).into()
}
}
impl<'tcx> From<InterpError<'tcx>> for InterpErrorInfo<'tcx> {
fn from(kind: InterpError<'tcx>) -> Self {
InterpErrorInfo(Box::new(InterpErrorInfoInner {
kind,
backtrace: InterpErrorBacktrace::new(),
}))
}
}
/// Error information for when the program we executed turned out not to actually be a valid
/// program. This cannot happen in stand-alone Miri, but it can happen during CTFE/ConstProp
/// where we work on generic code or execution does not have all information available.
#[derive(Debug)]
pub enum InvalidProgramInfo<'tcx> {
/// Resolution can fail if we are in a too generic context.
TooGeneric,
/// Abort in case errors are already reported.
AlreadyReported(ReportedErrorInfo),
/// An error occurred during layout computation.
Layout(layout::LayoutError<'tcx>),
/// An error occurred during FnAbi computation: the passed --target lacks FFI support
/// (which unfortunately typeck does not reject).
/// Not using `FnAbiError` as that contains a nested `LayoutError`.
FnAbiAdjustForForeignAbi(call::AdjustForForeignAbiError),
/// We are runnning into a nonsense situation due to ConstProp violating our invariants.
ConstPropNonsense,
}
/// Details of why a pointer had to be in-bounds.
#[derive(Debug, Copy, Clone, TyEncodable, TyDecodable, HashStable)]
pub enum CheckInAllocMsg {
/// We are dereferencing a pointer (i.e., creating a place).
DerefTest,
/// We are access memory.
MemoryAccessTest,
/// We are doing pointer arithmetic.
PointerArithmeticTest,
/// We are doing pointer offset_from.
OffsetFromTest,
/// None of the above -- generic/unspecific inbounds test.
InboundsTest,
}
#[derive(Debug, Copy, Clone, TyEncodable, TyDecodable, HashStable)]
pub enum InvalidMetaKind {
/// Size of a `[T]` is too big
SliceTooBig,
/// Size of a DST is too big
TooBig,
}
impl IntoDiagnosticArg for InvalidMetaKind {
fn into_diagnostic_arg(self) -> DiagnosticArgValue<'static> {
DiagnosticArgValue::Str(Cow::Borrowed(match self {
InvalidMetaKind::SliceTooBig => "slice_too_big",
InvalidMetaKind::TooBig => "too_big",
}))
}
}
/// Details of an access to uninitialized bytes / bad pointer bytes where it is not allowed.
#[derive(Debug, Clone, Copy)]
pub struct BadBytesAccess {
/// Range of the original memory access.
pub access: AllocRange,
/// Range of the bad memory that was encountered. (Might not be maximal.)
pub bad: AllocRange,
}
/// Information about a size mismatch.
#[derive(Debug)]
pub struct ScalarSizeMismatch {
pub target_size: u64,
pub data_size: u64,
}
macro_rules! impl_into_diagnostic_arg_through_debug {
($($ty:ty),*$(,)?) => {$(
impl IntoDiagnosticArg for $ty {
fn into_diagnostic_arg(self) -> DiagnosticArgValue<'static> {
DiagnosticArgValue::Str(Cow::Owned(format!("{self:?}")))
}
}
)*}
}
// These types have nice `Debug` output so we can just use them in diagnostics.
impl_into_diagnostic_arg_through_debug! {
AllocId,
Pointer,
AllocRange,
}
/// Error information for when the program caused Undefined Behavior.
#[derive(Debug)]
pub enum UndefinedBehaviorInfo<'a> {
/// Free-form case. Only for errors that are never caught! Used by miri
Ub(String),
/// Unreachable code was executed.
Unreachable,
/// A slice/array index projection went out-of-bounds.
BoundsCheckFailed { len: u64, index: u64 },
/// Something was divided by 0 (x / 0).
DivisionByZero,
/// Something was "remainded" by 0 (x % 0).
RemainderByZero,
/// Signed division overflowed (INT_MIN / -1).
DivisionOverflow,
/// Signed remainder overflowed (INT_MIN % -1).
RemainderOverflow,
/// Overflowing inbounds pointer arithmetic.
PointerArithOverflow,
/// Invalid metadata in a wide pointer
InvalidMeta(InvalidMetaKind),
/// Reading a C string that does not end within its allocation.
UnterminatedCString(Pointer),
/// Using a pointer after it got freed.
PointerUseAfterFree(AllocId, CheckInAllocMsg),
/// Used a pointer outside the bounds it is valid for.
/// (If `ptr_size > 0`, determines the size of the memory range that was expected to be in-bounds.)
PointerOutOfBounds {
alloc_id: AllocId,
alloc_size: Size,
ptr_offset: i64,
ptr_size: Size,
msg: CheckInAllocMsg,
},
/// Using an integer as a pointer in the wrong way.
DanglingIntPointer(u64, CheckInAllocMsg),
/// Used a pointer with bad alignment.
AlignmentCheckFailed { required: Align, has: Align },
/// Writing to read-only memory.
WriteToReadOnly(AllocId),
/// Trying to access the data behind a function pointer.
DerefFunctionPointer(AllocId),
/// Trying to access the data behind a vtable pointer.
DerefVTablePointer(AllocId),
/// Using a non-boolean `u8` as bool.
InvalidBool(u8),
/// Using a non-character `u32` as character.
InvalidChar(u32),
/// The tag of an enum does not encode an actual discriminant.
InvalidTag(Scalar),
/// Using a pointer-not-to-a-function as function pointer.
InvalidFunctionPointer(Pointer),
/// Using a pointer-not-to-a-vtable as vtable pointer.
InvalidVTablePointer(Pointer),
/// Using a string that is not valid UTF-8,
InvalidStr(std::str::Utf8Error),
/// Using uninitialized data where it is not allowed.
InvalidUninitBytes(Option<(AllocId, BadBytesAccess)>),
/// Working with a local that is not currently live.
DeadLocal,
/// Data size is not equal to target size.
ScalarSizeMismatch(ScalarSizeMismatch),
/// A discriminant of an uninhabited enum variant is written.
UninhabitedEnumVariantWritten(VariantIdx),
/// An uninhabited enum variant is projected.
UninhabitedEnumVariantRead(VariantIdx),
/// Validation error.
ValidationError(ValidationErrorInfo<'a>),
// FIXME(fee1-dead) these should all be actual variants of the enum instead of dynamically
// dispatched
/// A custom (free-form) error, created by `err_ub_custom!`.
Custom(crate::error::CustomSubdiagnostic<'a>),
}
#[derive(Debug, Clone, Copy)]
pub enum PointerKind {
Ref,
Box,
}
impl IntoDiagnosticArg for PointerKind {
fn into_diagnostic_arg(self) -> DiagnosticArgValue<'static> {
DiagnosticArgValue::Str(
match self {
Self::Ref => "ref",
Self::Box => "box",
}
.into(),
)
}
}
#[derive(Debug)]
pub struct ValidationErrorInfo<'tcx> {
pub path: Option<String>,
pub kind: ValidationErrorKind<'tcx>,
}
#[derive(Debug)]
pub enum ExpectedKind {
Reference,
Box,
RawPtr,
InitScalar,
Bool,
Char,
Float,
Int,
FnPtr,
EnumTag,
Str,
}
impl From<PointerKind> for ExpectedKind {
fn from(x: PointerKind) -> ExpectedKind {
match x {
PointerKind::Box => ExpectedKind::Box,
PointerKind::Ref => ExpectedKind::Reference,
}
}
}
#[derive(Debug)]
pub enum ValidationErrorKind<'tcx> {
PointerAsInt { expected: ExpectedKind },
PartialPointer,
PtrToUninhabited { ptr_kind: PointerKind, ty: Ty<'tcx> },
PtrToStatic { ptr_kind: PointerKind },
PtrToMut { ptr_kind: PointerKind },
MutableRefInConst,
NullFnPtr,
NeverVal,
NullablePtrOutOfRange { range: WrappingRange, max_value: u128 },
PtrOutOfRange { range: WrappingRange, max_value: u128 },
OutOfRange { value: String, range: WrappingRange, max_value: u128 },
UnsafeCell,
UninhabitedVal { ty: Ty<'tcx> },
InvalidEnumTag { value: String },
UninhabitedEnumVariant,
Uninit { expected: ExpectedKind },
InvalidVTablePtr { value: String },
InvalidMetaSliceTooLarge { ptr_kind: PointerKind },
InvalidMetaTooLarge { ptr_kind: PointerKind },
UnalignedPtr { ptr_kind: PointerKind, required_bytes: u64, found_bytes: u64 },
NullPtr { ptr_kind: PointerKind },
DanglingPtrNoProvenance { ptr_kind: PointerKind, pointer: String },
DanglingPtrOutOfBounds { ptr_kind: PointerKind },
DanglingPtrUseAfterFree { ptr_kind: PointerKind },
InvalidBool { value: String },
InvalidChar { value: String },
InvalidFnPtr { value: String },
}
/// Error information for when the program did something that might (or might not) be correct
/// to do according to the Rust spec, but due to limitations in the interpreter, the
/// operation could not be carried out. These limitations can differ between CTFE and the
/// Miri engine, e.g., CTFE does not support dereferencing pointers at integral addresses.
#[derive(Debug)]
pub enum UnsupportedOpInfo {
/// Free-form case. Only for errors that are never caught!
// FIXME still use translatable diagnostics
Unsupported(String),
//
// The variants below are only reachable from CTFE/const prop, miri will never emit them.
//
/// Overwriting parts of a pointer; without knowing absolute addresses, the resulting state
/// cannot be represented by the CTFE interpreter.
OverwritePartialPointer(Pointer<AllocId>),
/// Attempting to read or copy parts of a pointer to somewhere else; without knowing absolute
/// addresses, the resulting state cannot be represented by the CTFE interpreter.
ReadPartialPointer(Pointer<AllocId>),
/// Encountered a pointer where we needed an integer.
ReadPointerAsInt(Option<(AllocId, BadBytesAccess)>),
/// Accessing thread local statics
ThreadLocalStatic(DefId),
/// Accessing an unsupported extern static.
ReadExternStatic(DefId),
}
/// Error information for when the program exhausted the resources granted to it
/// by the interpreter.
#[derive(Debug)]
pub enum ResourceExhaustionInfo {
/// The stack grew too big.
StackFrameLimitReached,
/// There is not enough memory (on the host) to perform an allocation.
MemoryExhausted,
/// The address space (of the target) is full.
AddressSpaceFull,
}
/// A trait for machine-specific errors (or other "machine stop" conditions).
pub trait MachineStopType: Any + fmt::Debug + Send {
/// The diagnostic message for this error
fn diagnostic_message(&self) -> DiagnosticMessage;
/// Add diagnostic arguments by passing name and value pairs to `adder`, which are passed to
/// fluent for formatting the translated diagnostic message.
fn add_args(
self: Box<Self>,
adder: &mut dyn FnMut(Cow<'static, str>, DiagnosticArgValue<'static>),
);
}
impl dyn MachineStopType {
#[inline(always)]
pub fn downcast_ref<T: Any>(&self) -> Option<&T> {
let x: &dyn Any = self;
x.downcast_ref()
}
}
#[derive(Debug)]
pub enum InterpError<'tcx> {
/// The program caused undefined behavior.
UndefinedBehavior(UndefinedBehaviorInfo<'tcx>),
/// The program did something the interpreter does not support (some of these *might* be UB
/// but the interpreter is not sure).
Unsupported(UnsupportedOpInfo),
/// The program was invalid (ill-typed, bad MIR, not sufficiently monomorphized, ...).
InvalidProgram(InvalidProgramInfo<'tcx>),
/// The program exhausted the interpreter's resources (stack/heap too big,
/// execution takes too long, ...).
ResourceExhaustion(ResourceExhaustionInfo),
/// Stop execution for a machine-controlled reason. This is never raised by
/// the core engine itself.
MachineStop(Box<dyn MachineStopType>),
}
pub type InterpResult<'tcx, T = ()> = Result<T, InterpErrorInfo<'tcx>>;
impl InterpError<'_> {
/// Some errors do string formatting even if the error is never printed.
/// To avoid performance issues, there are places where we want to be sure to never raise these formatting errors,
/// so this method lets us detect them and `bug!` on unexpected errors.
pub fn formatted_string(&self) -> bool {
matches!(
self,
InterpError::Unsupported(UnsupportedOpInfo::Unsupported(_))
| InterpError::UndefinedBehavior(UndefinedBehaviorInfo::ValidationError { .. })
| InterpError::UndefinedBehavior(UndefinedBehaviorInfo::Ub(_))
)
}
}
|