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Auto merge of #122629 - RalfJung:assert-unsafe-precondition, r=saethlin 

refactor check_{lang,library}_ub: use a single intrinsic

This enacts the plan I laid out [here](https://github.com/rust-lang/rust/pull/122282#issuecomment-1996917998): use a single intrinsic, called `ub_checks` (in aniticpation of https://github.com/rust-lang/compiler-team/issues/725), that just exposes the value of `debug_assertions` (consistently implemented in both codegen and the interpreter). Put the language vs library UB logic into the library.

This makes it easier to do something like https://github.com/rust-lang/rust/pull/122282 in the future: that just slightly alters the semantics of `ub_checks` (making it more approximating when crates built with different flags are mixed), but it no longer affects whether these checks can happen in Miri or compile-time.

The first commit just moves things around; I don't think these macros and functions belong into `intrinsics.rs` as they are not intrinsics.

r? `@saethlin`
This commit is contained in:
bors 2024-03-23 21:11:00 +00:00
parent e50ab29471 6177530420
commit 2f090c30dd
48 changed files with 313 additions and 291 deletions
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2
compiler/rustc_borrowck/src/type_check/mod.rs
View File

@ -2000,7 +2000,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
ConstraintCategory::SizedBound,
);
}
&Rvalue::NullaryOp(NullOp::UbCheck(_), _) => {}
&Rvalue::NullaryOp(NullOp::UbChecks, _) => {}
Rvalue::ShallowInitBox(operand, ty) => {
self.check_operand(operand, location);

2
compiler/rustc_codegen_cranelift/src/base.rs
View File

@ -780,7 +780,7 @@ fn codegen_stmt<'tcx>(
NullOp::OffsetOf(fields) => {
layout.offset_of_subfield(fx, fields.iter()).bytes()
}
NullOp::UbCheck(_) => {
NullOp::UbChecks => {
let val = fx.tcx.sess.opts.debug_assertions;
let val = CValue::by_val(
fx.bcx.ins().iconst(types::I8, i64::try_from(val).unwrap()),

3
compiler/rustc_codegen_ssa/src/mir/rvalue.rs
View File

@ -680,8 +680,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
let val = layout.offset_of_subfield(bx.cx(), fields.iter()).bytes();
bx.cx().const_usize(val)
}
mir::NullOp::UbCheck(_) => {
// In codegen, we want to check for language UB and library UB
mir::NullOp::UbChecks => {
let val = bx.tcx().sess.opts.debug_assertions;
bx.cx().const_bool(val)
}

12
compiler/rustc_const_eval/src/interpret/step.rs
View File

@ -258,17 +258,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
let val = layout.offset_of_subfield(self, fields.iter()).bytes();
Scalar::from_target_usize(val, self)
}
mir::NullOp::UbCheck(kind) => {
// We want to enable checks for library UB, because the interpreter doesn't
// know about those on its own.
// But we want to disable checks for language UB, because the interpreter
// has its own better checks for that.
let should_check = match kind {
mir::UbKind::LibraryUb => self.tcx.sess.opts.debug_assertions,
mir::UbKind::LanguageUb => false,
};
Scalar::from_bool(should_check)
}
mir::NullOp::UbChecks => Scalar::from_bool(self.tcx.sess.opts.debug_assertions),
};
self.write_scalar(val, &dest)?;
}

2
compiler/rustc_const_eval/src/transform/check_consts/check.rs
View File

@ -558,7 +558,7 @@ impl<'tcx> Visitor<'tcx> for Checker<'_, 'tcx> {
Rvalue::Cast(_, _, _) => {}
Rvalue::NullaryOp(
NullOp::SizeOf | NullOp::AlignOf | NullOp::OffsetOf(_) | NullOp::UbCheck(_),
NullOp::SizeOf | NullOp::AlignOf | NullOp::OffsetOf(_) | NullOp::UbChecks,
_,
) => {}
Rvalue::ShallowInitBox(_, _) => {}

2
compiler/rustc_const_eval/src/transform/validate.rs
View File

@ -1168,7 +1168,7 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
Rvalue::Repeat(_, _)
| Rvalue::ThreadLocalRef(_)
| Rvalue::AddressOf(_, _)
| Rvalue::NullaryOp(NullOp::SizeOf | NullOp::AlignOf | NullOp::UbCheck(_), _)
| Rvalue::NullaryOp(NullOp::SizeOf | NullOp::AlignOf | NullOp::UbChecks, _)
| Rvalue::Discriminant(_) => {}
}
self.super_rvalue(rvalue, location);

5
compiler/rustc_hir_analysis/src/check/intrinsic.rs
View File

@ -127,8 +127,7 @@ pub fn intrinsic_operation_unsafety(tcx: TyCtxt<'_>, intrinsic_id: LocalDefId) -
| sym::variant_count
| sym::is_val_statically_known
| sym::ptr_mask
| sym::check_language_ub
| sym::check_library_ub
| sym::ub_checks
| sym::fadd_algebraic
| sym::fsub_algebraic
| sym::fmul_algebraic
@ -571,7 +570,7 @@ pub fn check_intrinsic_type(
(0, 0, vec![Ty::new_imm_ptr(tcx, Ty::new_unit(tcx))], tcx.types.usize)
}
sym::check_language_ub | sym::check_library_ub => (0, 1, Vec::new(), tcx.types.bool),
sym::ub_checks => (0, 1, Vec::new(), tcx.types.bool),
sym::simd_eq
| sym::simd_ne

2
compiler/rustc_middle/src/mir/mod.rs
View File

@ -796,7 +796,7 @@ impl<'tcx> Body<'tcx> {
}
match rvalue {
Rvalue::NullaryOp(NullOp::UbCheck(_), _) => {
Rvalue::NullaryOp(NullOp::UbChecks, _) => {
Some((tcx.sess.opts.debug_assertions as u128, targets))
}
Rvalue::Use(Operand::Constant(constant)) => {

2
compiler/rustc_middle/src/mir/pretty.rs
View File

@ -944,7 +944,7 @@ impl<'tcx> Debug for Rvalue<'tcx> {
NullOp::SizeOf => write!(fmt, "SizeOf({t})"),
NullOp::AlignOf => write!(fmt, "AlignOf({t})"),
NullOp::OffsetOf(fields) => write!(fmt, "OffsetOf({t}, {fields:?})"),
NullOp::UbCheck(kind) => write!(fmt, "UbCheck({kind:?})"),
NullOp::UbChecks => write!(fmt, "UbChecks()"),
}
}
ThreadLocalRef(did) => ty::tls::with(|tcx| {

13
compiler/rustc_middle/src/mir/syntax.rs
View File

@ -1367,16 +1367,9 @@ pub enum NullOp<'tcx> {
AlignOf,
/// Returns the offset of a field
OffsetOf(&'tcx List<(VariantIdx, FieldIdx)>),
/// Returns whether we want to check for library UB or language UB at monomorphization time.
/// Both kinds of UB evaluate to `true` in codegen, and only library UB evalutes to `true` in
/// const-eval/Miri, because the interpreter has its own better checks for language UB.
UbCheck(UbKind),
}
#[derive(Clone, Copy, Debug, PartialEq, Eq, TyEncodable, TyDecodable, Hash, HashStable)]
pub enum UbKind {
LanguageUb,
LibraryUb,
/// Returns whether we want to check for UB.
/// This returns the value of `cfg!(debug_assertions)` at monomorphization time.
UbChecks,
}
#[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]

2
compiler/rustc_middle/src/mir/tcx.rs
View File

@ -194,7 +194,7 @@ impl<'tcx> Rvalue<'tcx> {
Rvalue::NullaryOp(NullOp::SizeOf | NullOp::AlignOf | NullOp::OffsetOf(..), _) => {
tcx.types.usize
}
Rvalue::NullaryOp(NullOp::UbCheck(_), _) => tcx.types.bool,
Rvalue::NullaryOp(NullOp::UbChecks, _) => tcx.types.bool,
Rvalue::Aggregate(ref ak, ref ops) => match **ak {
AggregateKind::Array(ty) => Ty::new_array(tcx, ty, ops.len() as u64),
AggregateKind::Tuple => {

2
compiler/rustc_mir_dataflow/src/move_paths/builder.rs
View File

@ -433,7 +433,7 @@ impl<'b, 'a, 'tcx, F: Fn(Ty<'tcx>) -> bool> Gatherer<'b, 'a, 'tcx, F> {
| Rvalue::Discriminant(..)
| Rvalue::Len(..)
| Rvalue::NullaryOp(
NullOp::SizeOf | NullOp::AlignOf | NullOp::OffsetOf(..) | NullOp::UbCheck(_),
NullOp::SizeOf | NullOp::AlignOf | NullOp::OffsetOf(..) | NullOp::UbChecks,
_,
) => {}
}

2
compiler/rustc_mir_transform/src/gvn.rs
View File

@ -487,7 +487,7 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
NullOp::OffsetOf(fields) => {
layout.offset_of_subfield(&self.ecx, fields.iter()).bytes()
}
NullOp::UbCheck(_) => return None,
NullOp::UbChecks => return None,
};
let usize_layout = self.ecx.layout_of(self.tcx.types.usize).unwrap();
let imm = ImmTy::try_from_uint(val, usize_layout)?;

2
compiler/rustc_mir_transform/src/known_panics_lint.rs
View File

@ -639,7 +639,7 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> {
NullOp::OffsetOf(fields) => {
op_layout.offset_of_subfield(self, fields.iter()).bytes()
}
NullOp::UbCheck(_) => return None,
NullOp::UbChecks => return None,
};
ImmTy::from_scalar(Scalar::from_target_usize(val, self), layout).into()
}

21
compiler/rustc_mir_transform/src/lower_intrinsics.rs
View File

@ -20,30 +20,13 @@ impl<'tcx> MirPass<'tcx> for LowerIntrinsics {
sym::unreachable => {
terminator.kind = TerminatorKind::Unreachable;
}
sym::check_language_ub => {
sym::ub_checks => {
let target = target.unwrap();
block.statements.push(Statement {
source_info: terminator.source_info,
kind: StatementKind::Assign(Box::new((
*destination,
Rvalue::NullaryOp(
NullOp::UbCheck(UbKind::LanguageUb),
tcx.types.bool,
),
))),
});
terminator.kind = TerminatorKind::Goto { target };
}
sym::check_library_ub => {
let target = target.unwrap();
block.statements.push(Statement {
source_info: terminator.source_info,
kind: StatementKind::Assign(Box::new((
*destination,
Rvalue::NullaryOp(
NullOp::UbCheck(UbKind::LibraryUb),
tcx.types.bool,
),
Rvalue::NullaryOp(NullOp::UbChecks, tcx.types.bool),
))),
});
terminator.kind = TerminatorKind::Goto { target };

2
compiler/rustc_mir_transform/src/promote_consts.rs
View File

@ -446,7 +446,7 @@ impl<'tcx> Validator<'_, 'tcx> {
NullOp::SizeOf => {}
NullOp::AlignOf => {}
NullOp::OffsetOf(_) => {}
NullOp::UbCheck(_) => {}
NullOp::UbChecks => {}
},
Rvalue::ShallowInitBox(_, _) => return Err(Unpromotable),

8
compiler/rustc_smir/src/rustc_smir/convert/mir.rs
View File

@ -251,19 +251,13 @@ impl<'tcx> Stable<'tcx> for mir::NullOp<'tcx> {
type T = stable_mir::mir::NullOp;
fn stable(&self, tables: &mut Tables<'_>) -> Self::T {
use rustc_middle::mir::NullOp::*;
use rustc_middle::mir::UbKind;
match self {
SizeOf => stable_mir::mir::NullOp::SizeOf,
AlignOf => stable_mir::mir::NullOp::AlignOf,
OffsetOf(indices) => stable_mir::mir::NullOp::OffsetOf(
indices.iter().map(|idx| idx.stable(tables)).collect(),
),
UbCheck(UbKind::LanguageUb) => {
stable_mir::mir::NullOp::UbCheck(stable_mir::mir::UbKind::LanguageUb)
}
UbCheck(UbKind::LibraryUb) => {
stable_mir::mir::NullOp::UbCheck(stable_mir::mir::UbKind::LibraryUb)
}
UbChecks => stable_mir::mir::NullOp::UbChecks,
}
}
}

3
compiler/rustc_span/src/symbol.rs
View File

@ -518,8 +518,6 @@ symbols! {
cfi,
cfi_encoding,
char,
check_language_ub,
check_library_ub,
client,
clippy,
clobber_abi,
@ -1867,6 +1865,7 @@ symbols! {
u8_legacy_fn_max_value,
u8_legacy_fn_min_value,
u8_legacy_mod,
ub_checks,
unaligned_volatile_load,
unaligned_volatile_store,
unboxed_closures,

10
compiler/stable_mir/src/mir/body.rs
View File

@ -621,7 +621,7 @@ impl Rvalue {
Rvalue::NullaryOp(NullOp::SizeOf | NullOp::AlignOf | NullOp::OffsetOf(..), _) => {
Ok(Ty::usize_ty())
}
Rvalue::NullaryOp(NullOp::UbCheck(_), _) => Ok(Ty::bool_ty()),
Rvalue::NullaryOp(NullOp::UbChecks, _) => Ok(Ty::bool_ty()),
Rvalue::Aggregate(ak, ops) => match *ak {
AggregateKind::Array(ty) => Ty::try_new_array(ty, ops.len() as u64),
AggregateKind::Tuple => Ok(Ty::new_tuple(
@ -989,13 +989,7 @@ pub enum NullOp {
/// Returns the offset of a field.
OffsetOf(Vec<(VariantIdx, FieldIdx)>),
/// cfg!(debug_assertions), but at codegen time
UbCheck(UbKind),
}
#[derive(Clone, Debug, Eq, PartialEq)]
pub enum UbKind {
LanguageUb,
LibraryUb,
UbChecks,
}
impl Operand {

2
library/core/src/char/convert.rs
View File

@ -4,9 +4,9 @@ use crate::char::TryFromCharError;
use crate::convert::TryFrom;
use crate::error::Error;
use crate::fmt;
use crate::intrinsics::assert_unsafe_precondition;
use crate::mem::transmute;
use crate::str::FromStr;
use crate::ub_checks::assert_unsafe_precondition;
/// Converts a `u32` to a `char`. See [`char::from_u32`].
#[must_use]

5
library/core/src/hint.rs
View File

@ -4,6 +4,7 @@
//! Hints may be compile time or runtime.
use crate::intrinsics;
use crate::ub_checks;
/// Informs the compiler that the site which is calling this function is not
/// reachable, possibly enabling further optimizations.
@ -98,7 +99,7 @@ use crate::intrinsics;
#[rustc_const_stable(feature = "const_unreachable_unchecked", since = "1.57.0")]
#[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
pub const unsafe fn unreachable_unchecked() -> ! {
intrinsics::assert_unsafe_precondition!(
ub_checks::assert_unsafe_precondition!(
check_language_ub,
"hint::unreachable_unchecked must never be reached",
() => false
@ -148,7 +149,7 @@ pub const unsafe fn unreachable_unchecked() -> ! {
pub const unsafe fn assert_unchecked(cond: bool) {
// SAFETY: The caller promised `cond` is true.
unsafe {
intrinsics::assert_unsafe_precondition!(
ub_checks::assert_unsafe_precondition!(
check_language_ub,
"hint::assert_unchecked must never be called when the condition is false",
(cond: bool = cond) => cond,

187
library/core/src/intrinsics.rs
View File

@ -67,6 +67,7 @@ use crate::marker::DiscriminantKind;
use crate::marker::Tuple;
use crate::mem::align_of;
use crate::ptr;
use crate::ub_checks;
pub mod mir;
pub mod simd;
@ -2660,38 +2661,22 @@ pub const unsafe fn typed_swap<T>(x: *mut T, y: *mut T) {
unsafe { ptr::swap_nonoverlapping(x, y, 1) };
}
/// Returns whether we should check for library UB. This evaluate to the value of `cfg!(debug_assertions)`
/// during monomorphization.
/// Returns whether we should perform some UB-checking at runtime. This evaluate to the value of
/// `cfg!(debug_assertions)` during monomorphization.
///
/// This intrinsic is evaluated after monomorphization, and therefore branching on this value can
/// be used to implement debug assertions that are included in the precompiled standard library,
/// but can be optimized out by builds that monomorphize the standard library code with debug
/// assertions disabled. This intrinsic is primarily used by [`assert_unsafe_precondition`].
///
/// We have separate intrinsics for library UB and language UB because checkers like the const-eval
/// interpreter and Miri already implement checks for language UB. Since such checkers do not know
/// about library preconditions, checks guarded by this intrinsic let them find more UB.
#[rustc_const_unstable(feature = "ub_checks", issue = "none")]
/// This intrinsic is evaluated after monomorphization, which is relevant when mixing crates
/// compiled with and without debug_assertions. The common case here is a user program built with
/// debug_assertions linked against the distributed sysroot which is built without debug_assertions.
/// For code that gets monomorphized in the user crate (i.e., generic functions and functions with
/// `#[inline]`), gating assertions on `ub_checks()` rather than `cfg!(debug_assertions)` means that
/// assertions are enabled whenever the *user crate* has debug assertions enabled. However if the
/// user has debug assertions disabled, the checks will still get optimized out. This intrinsic is
/// primarily used by [`ub_checks::assert_unsafe_precondition`].
#[rustc_const_unstable(feature = "const_ub_checks", issue = "none")]
#[unstable(feature = "core_intrinsics", issue = "none")]
#[inline(always)]
#[rustc_intrinsic]
pub(crate) const fn check_library_ub() -> bool {
cfg!(debug_assertions)
}
/// Returns whether we should check for language UB. This evaluate to the value of `cfg!(debug_assertions)`
/// during monomorphization.
///
/// Since checks implemented at the source level must come strictly before the operation that
/// executes UB, if we enabled language UB checks in const-eval/Miri we would miss out on the
/// interpreter's improved diagnostics for the cases that our source-level checks catch.
///
/// See `check_library_ub` for more information.
#[rustc_const_unstable(feature = "ub_checks", issue = "none")]
#[unstable(feature = "core_intrinsics", issue = "none")]
#[inline(always)]
#[rustc_intrinsic]
pub(crate) const fn check_language_ub() -> bool {
#[cfg_attr(not(bootstrap), rustc_intrinsic)] // just make it a regular fn in bootstrap
pub(crate) const fn ub_checks() -> bool {
cfg!(debug_assertions)
}
@ -2755,132 +2740,6 @@ pub unsafe fn vtable_align(_ptr: *const ()) -> usize {
// (`transmute` also falls into this category, but it cannot be wrapped due to the
// check that `T` and `U` have the same size.)
/// Check that the preconditions of an unsafe function are followed. The check is enabled at
/// runtime if debug assertions are enabled when the caller is monomorphized. In const-eval/Miri
/// checks implemented with this macro for language UB are always ignored.
///
/// This macro should be called as
/// `assert_unsafe_precondition!(check_{library,lang}_ub, "message", (ident: type = expr, ident: type = expr) => check_expr)`
/// where each `expr` will be evaluated and passed in as function argument `ident: type`. Then all
/// those arguments are passed to a function with the body `check_expr`.
/// Pick `check_language_ub` when this is guarding a violation of language UB, i.e., immediate UB
/// according to the Rust Abstract Machine. Pick `check_library_ub` when this is guarding a violation
/// of a documented library precondition that does not *immediately* lead to language UB.
///
/// If `check_library_ub` is used but the check is actually guarding language UB, the check will
/// slow down const-eval/Miri and we'll get the panic message instead of the interpreter's nice
/// diagnostic, but our ability to detect UB is unchanged.
/// But if `check_language_ub` is used when the check is actually for library UB, the check is
/// omitted in const-eval/Miri and thus if we eventually execute language UB which relies on the
/// library UB, the backtrace Miri reports may be far removed from original cause.
///
/// These checks are behind a condition which is evaluated at codegen time, not expansion time like
/// [`debug_assert`]. This means that a standard library built with optimizations and debug
/// assertions disabled will have these checks optimized out of its monomorphizations, but if a
/// caller of the standard library has debug assertions enabled and monomorphizes an expansion of
/// this macro, that monomorphization will contain the check.
///
/// Since these checks cannot be optimized out in MIR, some care must be taken in both call and
/// implementation to mitigate their compile-time overhead. Calls to this macro always expand to
/// this structure:
/// ```ignore (pseudocode)
/// if ::core::intrinsics::check_language_ub() {
/// precondition_check(args)
/// }
/// ```
/// where `precondition_check` is monomorphic with the attributes `#[rustc_nounwind]`, `#[inline]` and
/// `#[rustc_no_mir_inline]`. This combination of attributes ensures that the actual check logic is
/// compiled only once and generates a minimal amount of IR because the check cannot be inlined in
/// MIR, but *can* be inlined and fully optimized by a codegen backend.
///
/// Callers should avoid introducing any other `let` bindings or any code outside this macro in
/// order to call it. Since the precompiled standard library is built with full debuginfo and these
/// variables cannot be optimized out in MIR, an innocent-looking `let` can produce enough
/// debuginfo to have a measurable compile-time impact on debug builds.
#[allow_internal_unstable(ub_checks)] // permit this to be called in stably-const fn
macro_rules! assert_unsafe_precondition {
($kind:ident, $message:expr, ($($name:ident:$ty:ty = $arg:expr),*$(,)?) => $e:expr $(,)?) => {
{
// This check is inlineable, but not by the MIR inliner.
// The reason for this is that the MIR inliner is in an exceptionally bad position
// to think about whether or not to inline this. In MIR, this call is gated behind `debug_assertions`,
// which will codegen to `false` in release builds. Inlining the check would be wasted work in that case and
// would be bad for compile times.
//
// LLVM on the other hand sees the constant branch, so if it's `false`, it can immediately delete it without
// inlining the check. If it's `true`, it can inline it and get significantly better performance.
#[rustc_no_mir_inline]
#[inline]
#[rustc_nounwind]
#[rustc_const_unstable(feature = "ub_checks", issue = "none")]
const fn precondition_check($($name:$ty),*) {
if !$e {
::core::panicking::panic_nounwind(
concat!("unsafe precondition(s) violated: ", $message)
);
}
}
if ::core::intrinsics::$kind() {
precondition_check($($arg,)*);
}
}
};
}
pub(crate) use assert_unsafe_precondition;
/// Checks whether `ptr` is properly aligned with respect to
/// `align_of::<T>()`.
///
/// In `const` this is approximate and can fail spuriously. It is primarily intended
/// for `assert_unsafe_precondition!` with `check_language_ub`, in which case the
/// check is anyway not executed in `const`.
#[inline]
pub(crate) const fn is_aligned_and_not_null(ptr: *const (), align: usize) -> bool {
!ptr.is_null() && ptr.is_aligned_to(align)
}
#[inline]
pub(crate) const fn is_valid_allocation_size(size: usize, len: usize) -> bool {
let max_len = if size == 0 { usize::MAX } else { isize::MAX as usize / size };
len <= max_len
}
/// Checks whether the regions of memory starting at `src` and `dst` of size
/// `count * size` do *not* overlap.
///
/// Note that in const-eval this function just returns `true` and therefore must
/// only be used with `assert_unsafe_precondition!`, similar to `is_aligned_and_not_null`.
#[inline]
pub(crate) const fn is_nonoverlapping(
src: *const (),
dst: *const (),
size: usize,
count: usize,
) -> bool {
#[inline]
fn runtime(src: *const (), dst: *const (), size: usize, count: usize) -> bool {
let src_usize = src.addr();
let dst_usize = dst.addr();
let Some(size) = size.checked_mul(count) else {
crate::panicking::panic_nounwind(
"is_nonoverlapping: `size_of::<T>() * count` overflows a usize",
)
};
let diff = src_usize.abs_diff(dst_usize);
// If the absolute distance between the ptrs is at least as big as the size of the buffer,
// they do not overlap.
diff >= size
}
#[inline]
const fn comptime(_: *const (), _: *const (), _: usize, _: usize) -> bool {
true
}
const_eval_select((src, dst, size, count), comptime, runtime)
}
/// Copies `count * size_of::<T>()` bytes from `src` to `dst`. The source
/// and destination must *not* overlap.
///
@ -2979,7 +2838,7 @@ pub const unsafe fn copy_nonoverlapping<T>(src: *const T, dst: *mut T, count: us
pub fn copy_nonoverlapping<T>(src: *const T, dst: *mut T, count: usize);
}
assert_unsafe_precondition!(
ub_checks::assert_unsafe_precondition!(
check_language_ub,
"ptr::copy_nonoverlapping requires that both pointer arguments are aligned and non-null \
and the specified memory ranges do not overlap",
@ -2990,9 +2849,9 @@ pub const unsafe fn copy_nonoverlapping<T>(src: *const T, dst: *mut T, count: us
align: usize = align_of::<T>(),
count: usize = count,
) =>
is_aligned_and_not_null(src, align)
&& is_aligned_and_not_null(dst, align)
&& is_nonoverlapping(src, dst, size, count)
ub_checks::is_aligned_and_not_null(src, align)
&& ub_checks::is_aligned_and_not_null(dst, align)
&& ub_checks::is_nonoverlapping(src, dst, size, count)
);
// SAFETY: the safety contract for `copy_nonoverlapping` must be
@ -3083,7 +2942,7 @@ pub const unsafe fn copy<T>(src: *const T, dst: *mut T, count: usize) {
// SAFETY: the safety contract for `copy` must be upheld by the caller.
unsafe {
assert_unsafe_precondition!(
ub_checks::assert_unsafe_precondition!(
check_language_ub,
"ptr::copy_nonoverlapping requires that both pointer arguments are aligned and non-null \
and the specified memory ranges do not overlap",
@ -3092,8 +2951,8 @@ pub const unsafe fn copy<T>(src: *const T, dst: *mut T, count: usize) {
dst: *mut () = dst as *mut (),
align: usize = align_of::<T>(),
) =>
is_aligned_and_not_null(src, align)
&& is_aligned_and_not_null(dst, align)
ub_checks::is_aligned_and_not_null(src, align)
&& ub_checks::is_aligned_and_not_null(dst, align)
);
copy(src, dst, count)
}
@ -3164,13 +3023,13 @@ pub const unsafe fn write_bytes<T>(dst: *mut T, val: u8, count: usize) {
// SAFETY: the safety contract for `write_bytes` must be upheld by the caller.
unsafe {
assert_unsafe_precondition!(
ub_checks::assert_unsafe_precondition!(
check_language_ub,
"ptr::write_bytes requires that the destination pointer is aligned and non-null",
(
addr: *const () = dst as *const (),
align: usize = align_of::<T>(),
) => is_aligned_and_not_null(addr, align)
) => ub_checks::is_aligned_and_not_null(addr, align)
);
write_bytes(dst, val, count)
}

2
library/core/src/lib.rs
View File

@ -171,6 +171,7 @@
#![feature(const_type_id)]
#![feature(const_type_name)]
#![feature(const_typed_swap)]
#![feature(const_ub_checks)]
#![feature(const_unicode_case_lookup)]
#![feature(const_unsafecell_get_mut)]
#![feature(const_waker)]
@ -366,6 +367,7 @@ pub mod hint;
pub mod intrinsics;
pub mod mem;
pub mod ptr;
mod ub_checks;
/* Core language traits */

5
library/core/src/num/nonzero.rs
View File

@ -9,6 +9,7 @@ use crate::ops::{BitOr, BitOrAssign, Div, DivAssign, Neg, Rem, RemAssign};
use crate::panic::{RefUnwindSafe, UnwindSafe};
use crate::ptr;
use crate::str::FromStr;
use crate::ub_checks;
use super::from_str_radix;
use super::{IntErrorKind, ParseIntError};
@ -369,7 +370,7 @@ where
None => {
// SAFETY: The caller guarantees that `n` is non-zero, so this is unreachable.
unsafe {
intrinsics::assert_unsafe_precondition!(
ub_checks::assert_unsafe_precondition!(
check_language_ub,
"NonZero::new_unchecked requires the argument to be non-zero",
() => false,
@ -409,7 +410,7 @@ where
None => {
// SAFETY: The caller guarantees that `n` references a value that is non-zero, so this is unreachable.
unsafe {
intrinsics::assert_unsafe_precondition!(
ub_checks::assert_unsafe_precondition!(
check_library_ub,
"NonZero::from_mut_unchecked requires the argument to dereference as non-zero",
() => false,

5
library/core/src/ops/index_range.rs
View File

@ -1,6 +1,7 @@
use crate::intrinsics::{assert_unsafe_precondition, unchecked_add, unchecked_sub};
use crate::intrinsics::{unchecked_add, unchecked_sub};
use crate::iter::{FusedIterator, TrustedLen};
use crate::num::NonZero;
use crate::ub_checks;
/// Like a `Range<usize>`, but with a safety invariant that `start <= end`.
///
@ -19,7 +20,7 @@ impl IndexRange {
/// - `start <= end`
#[inline]
pub const unsafe fn new_unchecked(start: usize, end: usize) -> Self {
assert_unsafe_precondition!(
ub_checks::assert_unsafe_precondition!(
check_library_ub,
"IndexRange::new_unchecked requires `start <= end`",
(start: usize = start, end: usize = end) => start <= end,

4
library/core/src/ptr/alignment.rs
View File

@ -1,7 +1,7 @@
use crate::convert::{TryFrom, TryInto};
#[cfg(debug_assertions)]
use crate::intrinsics::assert_unsafe_precondition;
use crate::num::NonZero;
#[cfg(debug_assertions)]
use crate::ub_checks::assert_unsafe_precondition;
use crate::{cmp, fmt, hash, mem, num};
/// A type storing a `usize` which is a power of two, and thus

2
library/core/src/ptr/const_ptr.rs
View File

@ -818,7 +818,7 @@ impl<T: ?Sized> *const T {
intrinsics::const_eval_select((this, origin), comptime, runtime)
}
assert_unsafe_precondition!(
ub_checks::assert_unsafe_precondition!(
check_language_ub,
"ptr::sub_ptr requires `self >= origin`",
(

33
library/core/src/ptr/mod.rs
View File

@ -388,10 +388,9 @@
use crate::cmp::Ordering;
use crate::fmt;
use crate::hash;
use crate::intrinsics::{
self, assert_unsafe_precondition, is_aligned_and_not_null, is_nonoverlapping,
};
use crate::intrinsics;
use crate::marker::FnPtr;
use crate::ub_checks;
use crate::mem::{self, align_of, size_of, MaybeUninit};
@ -1019,7 +1018,7 @@ pub const unsafe fn swap_nonoverlapping<T>(x: *mut T, y: *mut T, count: usize) {
};
}
assert_unsafe_precondition!(
ub_checks::assert_unsafe_precondition!(
check_language_ub,
"ptr::swap_nonoverlapping requires that both pointer arguments are aligned and non-null \
and the specified memory ranges do not overlap",
@ -1030,9 +1029,9 @@ pub const unsafe fn swap_nonoverlapping<T>(x: *mut T, y: *mut T, count: usize) {
align: usize = align_of::<T>(),
count: usize = count,
) =>
is_aligned_and_not_null(x, align)
&& is_aligned_and_not_null(y, align)
&& is_nonoverlapping(x, y, size, count)
ub_checks::is_aligned_and_not_null(x, align)
&& ub_checks::is_aligned_and_not_null(y, align)
&& ub_checks::is_nonoverlapping(x, y, size, count)
);
// Split up the slice into small power-of-two-sized chunks that LLVM is able
@ -1135,13 +1134,13 @@ pub const unsafe fn replace<T>(dst: *mut T, src: T) -> T {
// and cannot overlap `src` since `dst` must point to a distinct
// allocated object.
unsafe {
assert_unsafe_precondition!(
ub_checks::assert_unsafe_precondition!(
check_language_ub,
"ptr::replace requires that the pointer argument is aligned and non-null",
(
addr: *const () = dst as *const (),
align: usize = align_of::<T>(),
) => is_aligned_and_not_null(addr, align)
) => ub_checks::is_aligned_and_not_null(addr, align)
);
mem::replace(&mut *dst, src)
}
@ -1287,13 +1286,13 @@ pub const unsafe fn read<T>(src: *const T) -> T {
// SAFETY: the caller must guarantee that `src` is valid for reads.
unsafe {
#[cfg(debug_assertions)] // Too expensive to always enable (for now?)
assert_unsafe_precondition!(
ub_checks::assert_unsafe_precondition!(
check_language_ub,
"ptr::read requires that the pointer argument is aligned and non-null",
(
addr: *const () = src as *const (),
align: usize = align_of::<T>(),
) => is_aligned_and_not_null(addr, align)
) => ub_checks::is_aligned_and_not_null(addr, align)
);
crate::intrinsics::read_via_copy(src)
}
@ -1496,13 +1495,13 @@ pub const unsafe fn write<T>(dst: *mut T, src: T) {
// to `dst` while `src` is owned by this function.
unsafe {
#[cfg(debug_assertions)] // Too expensive to always enable (for now?)
assert_unsafe_precondition!(
ub_checks::assert_unsafe_precondition!(
check_language_ub,
"ptr::write requires that the pointer argument is aligned and non-null",
(
addr: *mut () = dst as *mut (),
align: usize = align_of::<T>(),
) => is_aligned_and_not_null(addr, align)
) => ub_checks::is_aligned_and_not_null(addr, align)
);
intrinsics::write_via_move(dst, src)
}
@ -1668,13 +1667,13 @@ pub const unsafe fn write_unaligned<T>(dst: *mut T, src: T) {
pub unsafe fn read_volatile<T>(src: *const T) -> T {
// SAFETY: the caller must uphold the safety contract for `volatile_load`.
unsafe {
assert_unsafe_precondition!(
ub_checks::assert_unsafe_precondition!(
check_language_ub,
"ptr::read_volatile requires that the pointer argument is aligned and non-null",
(
addr: *const () = src as *const (),
align: usize = align_of::<T>(),
) => is_aligned_and_not_null(addr, align)
) => ub_checks::is_aligned_and_not_null(addr, align)
);
intrinsics::volatile_load(src)
}
@ -1747,13 +1746,13 @@ pub unsafe fn read_volatile<T>(src: *const T) -> T {
pub unsafe fn write_volatile<T>(dst: *mut T, src: T) {
// SAFETY: the caller must uphold the safety contract for `volatile_store`.
unsafe {
assert_unsafe_precondition!(
ub_checks::assert_unsafe_precondition!(
check_language_ub,
"ptr::write_volatile requires that the pointer argument is aligned and non-null",
(
addr: *mut () = dst as *mut (),
align: usize = align_of::<T>(),
) => is_aligned_and_not_null(addr, align)
) => ub_checks::is_aligned_and_not_null(addr, align)
);
intrinsics::volatile_store(dst, src);
}

2
library/core/src/ptr/non_null.rs
View File

@ -2,7 +2,6 @@ use crate::cmp::Ordering;
use crate::fmt;
use crate::hash;
use crate::intrinsics;
use crate::intrinsics::assert_unsafe_precondition;
use crate::marker::Unsize;
use crate::mem::{MaybeUninit, SizedTypeProperties};
use crate::num::NonZero;
@ -10,6 +9,7 @@ use crate::ops::{CoerceUnsized, DispatchFromDyn};
use crate::ptr;
use crate::ptr::Unique;
use crate::slice::{self, SliceIndex};
use crate::ub_checks::assert_unsafe_precondition;
/// `*mut T` but non-zero and [covariant].
///

2
library/core/src/slice/index.rs
View File

@ -1,10 +1,10 @@
//! Indexing implementations for `[T]`.
use crate::intrinsics::assert_unsafe_precondition;
use crate::intrinsics::const_eval_select;
use crate::intrinsics::unchecked_sub;
use crate::ops;
use crate::ptr;
use crate::ub_checks::assert_unsafe_precondition;
#[stable(feature = "rust1", since = "1.0.0")]
impl<T, I> ops::Index<I> for [T]

2
library/core/src/slice/mod.rs
View File

@ -9,7 +9,6 @@
use crate::cmp::Ordering::{self, Equal, Greater, Less};
use crate::fmt;
use crate::hint;
use crate::intrinsics::assert_unsafe_precondition;
use crate::intrinsics::exact_div;
use crate::mem::{self, SizedTypeProperties};
use crate::num::NonZero;
@ -17,6 +16,7 @@ use crate::ops::{Bound, OneSidedRange, Range, RangeBounds};
use crate::ptr;
use crate::simd::{self, Simd};
use crate::slice;
use crate::ub_checks::assert_unsafe_precondition;
#[unstable(
feature = "slice_internals",

16
library/core/src/slice/raw.rs
View File

@ -1,12 +1,10 @@
//! Free functions to create `&[T]` and `&mut [T]`.
use crate::array;
use crate::intrinsics::{
assert_unsafe_precondition, is_aligned_and_not_null, is_valid_allocation_size,
};
use crate::mem::{align_of, size_of};
use crate::ops::Range;
use crate::ptr;
use crate::ub_checks;
/// Forms a slice from a pointer and a length.
///
@ -95,7 +93,7 @@ use crate::ptr;
pub const unsafe fn from_raw_parts<'a, T>(data: *const T, len: usize) -> &'a [T] {
// SAFETY: the caller must uphold the safety contract for `from_raw_parts`.
unsafe {
assert_unsafe_precondition!(
ub_checks::assert_unsafe_precondition!(
check_language_ub,
"slice::from_raw_parts requires the pointer to be aligned and non-null, and the total size of the slice not to exceed `isize::MAX`",
(
@ -104,8 +102,8 @@ pub const unsafe fn from_raw_parts<'a, T>(data: *const T, len: usize) -> &'a [T]
align: usize = align_of::<T>(),
len: usize = len,
) =>
is_aligned_and_not_null(data, align)
&& is_valid_allocation_size(size, len)
ub_checks::is_aligned_and_not_null(data, align)
&& ub_checks::is_valid_allocation_size(size, len)
);
&*ptr::slice_from_raw_parts(data, len)
}
@ -149,7 +147,7 @@ pub const unsafe fn from_raw_parts<'a, T>(data: *const T, len: usize) -> &'a [T]
pub const unsafe fn from_raw_parts_mut<'a, T>(data: *mut T, len: usize) -> &'a mut [T] {
// SAFETY: the caller must uphold the safety contract for `from_raw_parts_mut`.
unsafe {
assert_unsafe_precondition!(
ub_checks::assert_unsafe_precondition!(
check_language_ub,
"slice::from_raw_parts_mut requires the pointer to be aligned and non-null, and the total size of the slice not to exceed `isize::MAX`",
(
@ -158,8 +156,8 @@ pub const unsafe fn from_raw_parts_mut<'a, T>(data: *mut T, len: usize) -> &'a m
align: usize = align_of::<T>(),
len: usize = len,
) =>
is_aligned_and_not_null(data, align)
&& is_valid_allocation_size(size, len)
ub_checks::is_aligned_and_not_null(data, align)
&& ub_checks::is_valid_allocation_size(size, len)
);
&mut *ptr::slice_from_raw_parts_mut(data, len)
}

2
library/core/src/str/traits.rs
View File

@ -1,10 +1,10 @@
//! Trait implementations for `str`.
use crate::cmp::Ordering;
use crate::intrinsics::assert_unsafe_precondition;
use crate::ops;
use crate::ptr;
use crate::slice::SliceIndex;
use crate::ub_checks::assert_unsafe_precondition;
use super::ParseBoolError;

158
library/core/src/ub_checks.rs Normal file
View File

@ -0,0 +1,158 @@
//! Provides the [`assert_unsafe_precondition`] macro as well as some utility functions that cover
//! common preconditions.
use crate::intrinsics::{self, const_eval_select};
/// Check that the preconditions of an unsafe function are followed. The check is enabled at
/// runtime if debug assertions are enabled when the caller is monomorphized. In const-eval/Miri
/// checks implemented with this macro for language UB are always ignored.
///
/// This macro should be called as
/// `assert_unsafe_precondition!(check_{library,lang}_ub, "message", (ident: type = expr, ident: type = expr) => check_expr)`
/// where each `expr` will be evaluated and passed in as function argument `ident: type`. Then all
/// those arguments are passed to a function with the body `check_expr`.
/// Pick `check_language_ub` when this is guarding a violation of language UB, i.e., immediate UB
/// according to the Rust Abstract Machine. Pick `check_library_ub` when this is guarding a violation
/// of a documented library precondition that does not *immediately* lead to language UB.
///
/// If `check_library_ub` is used but the check is actually guarding language UB, the check will
/// slow down const-eval/Miri and we'll get the panic message instead of the interpreter's nice
/// diagnostic, but our ability to detect UB is unchanged.
/// But if `check_language_ub` is used when the check is actually for library UB, the check is
/// omitted in const-eval/Miri and thus if we eventually execute language UB which relies on the
/// library UB, the backtrace Miri reports may be far removed from original cause.
///
/// These checks are behind a condition which is evaluated at codegen time, not expansion time like
/// [`debug_assert`]. This means that a standard library built with optimizations and debug
/// assertions disabled will have these checks optimized out of its monomorphizations, but if a
/// caller of the standard library has debug assertions enabled and monomorphizes an expansion of
/// this macro, that monomorphization will contain the check.
///
/// Since these checks cannot be optimized out in MIR, some care must be taken in both call and
/// implementation to mitigate their compile-time overhead. Calls to this macro always expand to
/// this structure:
/// ```ignore (pseudocode)
/// if ::core::intrinsics::check_language_ub() {
/// precondition_check(args)
/// }
/// ```
/// where `precondition_check` is monomorphic with the attributes `#[rustc_nounwind]`, `#[inline]` and
/// `#[rustc_no_mir_inline]`. This combination of attributes ensures that the actual check logic is
/// compiled only once and generates a minimal amount of IR because the check cannot be inlined in
/// MIR, but *can* be inlined and fully optimized by a codegen backend.
///
/// Callers should avoid introducing any other `let` bindings or any code outside this macro in
/// order to call it. Since the precompiled standard library is built with full debuginfo and these
/// variables cannot be optimized out in MIR, an innocent-looking `let` can produce enough
/// debuginfo to have a measurable compile-time impact on debug builds.
#[allow_internal_unstable(const_ub_checks)] // permit this to be called in stably-const fn
macro_rules! assert_unsafe_precondition {
($kind:ident, $message:expr, ($($name:ident:$ty:ty = $arg:expr),*$(,)?) => $e:expr $(,)?) => {
{
// This check is inlineable, but not by the MIR inliner.
// The reason for this is that the MIR inliner is in an exceptionally bad position
// to think about whether or not to inline this. In MIR, this call is gated behind `debug_assertions`,
// which will codegen to `false` in release builds. Inlining the check would be wasted work in that case and
// would be bad for compile times.
//
// LLVM on the other hand sees the constant branch, so if it's `false`, it can immediately delete it without
// inlining the check. If it's `true`, it can inline it and get significantly better performance.
#[rustc_no_mir_inline]
#[inline]
#[rustc_nounwind]
#[rustc_const_unstable(feature = "const_ub_checks", issue = "none")]
const fn precondition_check($($name:$ty),*) {
if !$e {
::core::panicking::panic_nounwind(
concat!("unsafe precondition(s) violated: ", $message)
);
}
}
if ::core::ub_checks::$kind() {
precondition_check($($arg,)*);
}
}
};
}
pub(crate) use assert_unsafe_precondition;
/// Checking library UB is always enabled when UB-checking is done
/// (and we use a reexport so that there is no unnecessary wrapper function).
pub(crate) use intrinsics::ub_checks as check_library_ub;
/// Determines whether we should check for language UB.
///
/// The intention is to not do that when running in the interpreter, as that one has its own
/// language UB checks which generally produce better errors.
#[rustc_const_unstable(feature = "const_ub_checks", issue = "none")]
#[inline]
pub(crate) const fn check_language_ub() -> bool {
#[inline]
fn runtime() -> bool {
// Disable UB checks in Miri.
!cfg!(miri)
}
#[inline]
const fn comptime() -> bool {
// Always disable UB checks.
false
}
// Only used for UB checks so we may const_eval_select.
intrinsics::ub_checks() && const_eval_select((), comptime, runtime)
}
/// Checks whether `ptr` is properly aligned with respect to
/// `align_of::<T>()`.
///
/// In `const` this is approximate and can fail spuriously. It is primarily intended
/// for `assert_unsafe_precondition!` with `check_language_ub`, in which case the
/// check is anyway not executed in `const`.
#[inline]
pub(crate) const fn is_aligned_and_not_null(ptr: *const (), align: usize) -> bool {
!ptr.is_null() && ptr.is_aligned_to(align)
}
#[inline]
pub(crate) const fn is_valid_allocation_size(size: usize, len: usize) -> bool {
let max_len = if size == 0 { usize::MAX } else { isize::MAX as usize / size };
len <= max_len
}
/// Checks whether the regions of memory starting at `src` and `dst` of size
/// `count * size` do *not* overlap.
///
/// Note that in const-eval this function just returns `true` and therefore must
/// only be used with `assert_unsafe_precondition!`, similar to `is_aligned_and_not_null`.
#[inline]
pub(crate) const fn is_nonoverlapping(
src: *const (),
dst: *const (),
size: usize,
count: usize,
) -> bool {
#[inline]
fn runtime(src: *const (), dst: *const (), size: usize, count: usize) -> bool {
let src_usize = src.addr();
let dst_usize = dst.addr();
let Some(size) = size.checked_mul(count) else {
crate::panicking::panic_nounwind(
"is_nonoverlapping: `size_of::<T>() * count` overflows a usize",
)
};
let diff = src_usize.abs_diff(dst_usize);
// If the absolute distance between the ptrs is at least as big as the size of the buffer,
// they do not overlap.
diff >= size
}
#[inline]
const fn comptime(_: *const (), _: *const (), _: usize, _: usize) -> bool {
true
}
// This is just for safety checks so we can const_eval_select.
const_eval_select((src, dst, size, count), comptime, runtime)
}

2
src/tools/clippy/clippy_utils/src/qualify_min_const_fn.rs
View File

@ -174,7 +174,7 @@ fn check_rvalue<'tcx>(
))
}
},
Rvalue::NullaryOp(NullOp::SizeOf | NullOp::AlignOf | NullOp::OffsetOf(_) | NullOp::UbCheck(_), _)
Rvalue::NullaryOp(NullOp::SizeOf | NullOp::AlignOf | NullOp::OffsetOf(_) | NullOp::UbChecks, _)
| Rvalue::ShallowInitBox(_, _) => Ok(()),
Rvalue::UnaryOp(_, operand) => {
let ty = operand.ty(body, tcx);

6
tests/mir-opt/dataflow-const-prop/default_boxed_slice.main.DataflowConstProp.32bit.panic-abort.diff
View File

@ -28,6 +28,10 @@
let mut _10: *mut ();
let mut _11: *const [bool; 0];
scope 13 {
scope 14 (inlined core::ub_checks::check_language_ub) {
scope 15 (inlined core::ub_checks::check_language_ub::runtime) {
}
}
}
}
}
@ -60,7 +64,7 @@
StorageDead(_7);
StorageLive(_11);
StorageLive(_8);
_8 = UbCheck(LanguageUb);
_8 = UbChecks();
switchInt(move _8) -> [0: bb4, otherwise: bb2];
}

6
tests/mir-opt/dataflow-const-prop/default_boxed_slice.main.DataflowConstProp.32bit.panic-unwind.diff
View File

@ -28,6 +28,10 @@
let mut _10: *mut ();
let mut _11: *const [bool; 0];
scope 13 {
scope 14 (inlined core::ub_checks::check_language_ub) {
scope 15 (inlined core::ub_checks::check_language_ub::runtime) {
}
}
}
}
}
@ -60,7 +64,7 @@
StorageDead(_7);
StorageLive(_11);
StorageLive(_8);
_8 = UbCheck(LanguageUb);
_8 = UbChecks();
switchInt(move _8) -> [0: bb5, otherwise: bb3];
}

6
tests/mir-opt/dataflow-const-prop/default_boxed_slice.main.DataflowConstProp.64bit.panic-abort.diff
View File

@ -28,6 +28,10 @@
let mut _10: *mut ();
let mut _11: *const [bool; 0];
scope 13 {
scope 14 (inlined core::ub_checks::check_language_ub) {
scope 15 (inlined core::ub_checks::check_language_ub::runtime) {
}
}
}
}
}
@ -60,7 +64,7 @@
StorageDead(_7);
StorageLive(_11);
StorageLive(_8);
_8 = UbCheck(LanguageUb);
_8 = UbChecks();
switchInt(move _8) -> [0: bb4, otherwise: bb2];
}

6
tests/mir-opt/dataflow-const-prop/default_boxed_slice.main.DataflowConstProp.64bit.panic-unwind.diff
View File

@ -28,6 +28,10 @@
let mut _10: *mut ();
let mut _11: *const [bool; 0];
scope 13 {
scope 14 (inlined core::ub_checks::check_language_ub) {
scope 15 (inlined core::ub_checks::check_language_ub::runtime) {
}
}
}
}
}
@ -60,7 +64,7 @@
StorageDead(_7);
StorageLive(_11);
StorageLive(_8);
_8 = UbCheck(LanguageUb);
_8 = UbChecks();
switchInt(move _8) -> [0: bb5, otherwise: bb3];
}

6
tests/mir-opt/dataflow-const-prop/default_boxed_slice.main.GVN.32bit.panic-abort.diff
View File

@ -28,6 +28,10 @@
let mut _10: *mut ();
let mut _11: *const [bool; 0];
scope 13 {
scope 14 (inlined core::ub_checks::check_language_ub) {
scope 15 (inlined core::ub_checks::check_language_ub::runtime) {
}
}
}
}
}
@ -62,7 +66,7 @@
StorageDead(_7);
StorageLive(_11);
StorageLive(_8);
_8 = UbCheck(LanguageUb);
_8 = UbChecks();
switchInt(move _8) -> [0: bb4, otherwise: bb2];
}

6
tests/mir-opt/dataflow-const-prop/default_boxed_slice.main.GVN.32bit.panic-unwind.diff
View File

@ -28,6 +28,10 @@
let mut _10: *mut ();
let mut _11: *const [bool; 0];
scope 13 {
scope 14 (inlined core::ub_checks::check_language_ub) {
scope 15 (inlined core::ub_checks::check_language_ub::runtime) {
}
}
}
}
}
@ -62,7 +66,7 @@
StorageDead(_7);
StorageLive(_11);
StorageLive(_8);
_8 = UbCheck(LanguageUb);
_8 = UbChecks();
switchInt(move _8) -> [0: bb5, otherwise: bb3];
}

6
tests/mir-opt/dataflow-const-prop/default_boxed_slice.main.GVN.64bit.panic-abort.diff
View File

@ -28,6 +28,10 @@
let mut _10: *mut ();
let mut _11: *const [bool; 0];
scope 13 {
scope 14 (inlined core::ub_checks::check_language_ub) {
scope 15 (inlined core::ub_checks::check_language_ub::runtime) {
}
}
}
}
}
@ -62,7 +66,7 @@
StorageDead(_7);
StorageLive(_11);
StorageLive(_8);
_8 = UbCheck(LanguageUb);
_8 = UbChecks();
switchInt(move _8) -> [0: bb4, otherwise: bb2];
}

6
tests/mir-opt/dataflow-const-prop/default_boxed_slice.main.GVN.64bit.panic-unwind.diff
View File

@ -28,6 +28,10 @@
let mut _10: *mut ();
let mut _11: *const [bool; 0];
scope 13 {
scope 14 (inlined core::ub_checks::check_language_ub) {
scope 15 (inlined core::ub_checks::check_language_ub::runtime) {
}
}
}
}
}
@ -62,7 +66,7 @@
StorageDead(_7);
StorageLive(_11);
StorageLive(_8);
_8 = UbCheck(LanguageUb);
_8 = UbChecks();
switchInt(move _8) -> [0: bb5, otherwise: bb3];
}

6
tests/mir-opt/inline/unwrap_unchecked.unwrap_unchecked.Inline.panic-abort.diff
View File

@ -17,6 +17,10 @@
+ let _5: ();
+ scope 5 {
+ }
+ scope 6 (inlined core::ub_checks::check_language_ub) {
+ scope 7 (inlined core::ub_checks::check_language_ub::runtime) {
+ }
+ }
+ }
+ }
+ }
@ -37,7 +41,7 @@
+
+ bb2: {
+ StorageLive(_4);
+ _4 = UbCheck(LanguageUb);
+ _4 = UbChecks();
+ assume(_4);
+ _5 = unreachable_unchecked::precondition_check() -> [return: bb1, unwind unreachable];
+ }

6
tests/mir-opt/inline/unwrap_unchecked.unwrap_unchecked.Inline.panic-unwind.diff
View File

@ -17,6 +17,10 @@
+ let _5: ();
+ scope 5 {
+ }
+ scope 6 (inlined core::ub_checks::check_language_ub) {
+ scope 7 (inlined core::ub_checks::check_language_ub::runtime) {
+ }
+ }
+ }
+ }
+ }
@ -41,7 +45,7 @@
- resume;
+ bb2: {
+ StorageLive(_4);
+ _4 = UbCheck(LanguageUb);
+ _4 = UbChecks();
+ assume(_4);
+ _5 = unreachable_unchecked::precondition_check() -> [return: bb1, unwind unreachable];
+ }

6
tests/mir-opt/inline/unwrap_unchecked.unwrap_unchecked.PreCodegen.after.panic-abort.mir
View File

@ -15,6 +15,10 @@ fn unwrap_unchecked(_1: Option<T>) -> T {
let _4: ();
scope 5 {
}
scope 6 (inlined core::ub_checks::check_language_ub) {
scope 7 (inlined core::ub_checks::check_language_ub::runtime) {
}
}
}
}
}
@ -27,7 +31,7 @@ fn unwrap_unchecked(_1: Option<T>) -> T {
bb1: {
StorageLive(_3);
_3 = UbCheck(LanguageUb);
_3 = UbChecks();
assume(_3);
_4 = unreachable_unchecked::precondition_check() -> [return: bb3, unwind unreachable];
}

6
tests/mir-opt/inline/unwrap_unchecked.unwrap_unchecked.PreCodegen.after.panic-unwind.mir
View File

@ -15,6 +15,10 @@ fn unwrap_unchecked(_1: Option<T>) -> T {
let _4: ();
scope 5 {
}
scope 6 (inlined core::ub_checks::check_language_ub) {
scope 7 (inlined core::ub_checks::check_language_ub::runtime) {
}
}
}
}
}
@ -27,7 +31,7 @@ fn unwrap_unchecked(_1: Option<T>) -> T {
bb1: {
StorageLive(_3);
_3 = UbCheck(LanguageUb);
_3 = UbChecks();
assume(_3);
_4 = unreachable_unchecked::precondition_check() -> [return: bb3, unwind unreachable];
}

6
tests/mir-opt/pre-codegen/duplicate_switch_targets.ub_if_b.PreCodegen.after.mir
View File

@ -9,6 +9,10 @@ fn ub_if_b(_1: Thing) -> Thing {
let _4: ();
scope 2 {
}
scope 3 (inlined core::ub_checks::check_language_ub) {
scope 4 (inlined core::ub_checks::check_language_ub::runtime) {
}
}
}
bb0: {
@ -23,7 +27,7 @@ fn ub_if_b(_1: Thing) -> Thing {
bb2: {
StorageLive(_3);
_3 = UbCheck(LanguageUb);
_3 = UbChecks();
assume(_3);
_4 = unreachable_unchecked::precondition_check() -> [return: bb3, unwind unreachable];
}