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Auto merge of #119614 - RalfJung:const-refs-to-static, r=oli-obk

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unstably allow constants to refer to statics and read from immutable statics

I am not aware of any fundamental reason why we cannot allow constants to mention statics. What we really need is that constants do not *read from* statics that can change their value:
- This would break the principle that "constants behave as-if their expression was inlined everywhere and executed at runtime". This is enforced by halting const-eval interpretation when a read from a mutable global occurs.
- When building a valtree we want to be sure that the constant and everything it refers to is truly immutable. This is enforced by aborting valtree construction when a read from a mutable global occurs.

r? `@oli-obk` -- if you are okay with experimenting with this feature, I will create a tracking issue.
Based on and blocked on https://github.com/rust-lang/rust/pull/119044; only the last commit is new.
This commit is contained in:
bors 2024-02-10 15:52:24 +00:00
commit 6cc4843512
57 changed files with 750 additions and 518 deletions
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14
compiler/rustc_const_eval/messages.ftl
View file

@ -30,7 +30,9 @@ const_eval_closure_non_const =
cannot call non-const closure in {const_eval_const_context}s
const_eval_consider_dereferencing =
consider dereferencing here
const_eval_const_accesses_static = constant accesses static
const_eval_const_accesses_mut_global =
constant accesses mutable global memory
const_eval_const_context = {$kind ->
[const] constant
@ -319,12 +321,6 @@ const_eval_size_overflow =
const_eval_stack_frame_limit_reached =
reached the configured maximum number of stack frames
const_eval_static_access =
{const_eval_const_context}s cannot refer to statics
.help = consider extracting the value of the `static` to a `const`, and referring to that
.teach_note = `static` and `const` variables can refer to other `const` variables. A `const` variable, however, cannot refer to a `static` variable.
.teach_help = To fix this, the value can be extracted to a `const` and then used.
const_eval_thread_local_access =
thread-local statics cannot be accessed at compile-time
@ -415,6 +411,10 @@ const_eval_upcast_mismatch =
## (We'd love to sort this differently to make that more clear but tidy won't let us...)
const_eval_validation_box_to_static = {$front_matter}: encountered a box pointing to a static variable in a constant
const_eval_validation_box_to_uninhabited = {$front_matter}: encountered a box pointing to uninhabited type {$ty}
const_eval_validation_const_ref_to_extern = {$front_matter}: encountered reference to `extern` static in `const`
const_eval_validation_const_ref_to_mutable = {$front_matter}: encountered reference to mutable memory in `const`
const_eval_validation_dangling_box_no_provenance = {$front_matter}: encountered a dangling box ({$pointer} has no provenance)
const_eval_validation_dangling_box_out_of_bounds = {$front_matter}: encountered a dangling box (going beyond the bounds of its allocation)
const_eval_validation_dangling_box_use_after_free = {$front_matter}: encountered a dangling box (use-after-free)

6
compiler/rustc_const_eval/src/const_eval/error.rs
View file

@ -17,7 +17,7 @@ use crate::interpret::{ErrorHandled, InterpError, InterpErrorInfo, MachineStopTy
/// The CTFE machine has some custom error kinds.
#[derive(Clone, Debug)]
pub enum ConstEvalErrKind {
ConstAccessesStatic,
ConstAccessesMutGlobal,
ModifiedGlobal,
AssertFailure(AssertKind<ConstInt>),
Panic { msg: Symbol, line: u32, col: u32, file: Symbol },
@ -28,7 +28,7 @@ impl MachineStopType for ConstEvalErrKind {
use crate::fluent_generated::*;
use ConstEvalErrKind::*;
match self {
ConstAccessesStatic => const_eval_const_accesses_static,
ConstAccessesMutGlobal => const_eval_const_accesses_mut_global,
ModifiedGlobal => const_eval_modified_global,
Panic { .. } => const_eval_panic,
AssertFailure(x) => x.diagnostic_message(),
@ -37,7 +37,7 @@ impl MachineStopType for ConstEvalErrKind {
fn add_args(self: Box<Self>, adder: &mut dyn FnMut(DiagnosticArgName, DiagnosticArgValue)) {
use ConstEvalErrKind::*;
match *self {
ConstAccessesStatic | ModifiedGlobal => {}
ConstAccessesMutGlobal | ModifiedGlobal => {}
AssertFailure(kind) => kind.add_args(adder),
Panic { msg, line, col, file } => {
adder("msg".into(), msg.into_diagnostic_arg());

21
compiler/rustc_const_eval/src/const_eval/eval_queries.rs
View file

@ -11,7 +11,7 @@ use rustc_middle::ty::{self, TyCtxt};
use rustc_span::Span;
use rustc_target::abi::{self, Abi};
use super::{CanAccessStatics, CompileTimeEvalContext, CompileTimeInterpreter};
use super::{CanAccessMutGlobal, CompileTimeEvalContext, CompileTimeInterpreter};
use crate::const_eval::CheckAlignment;
use crate::errors;
use crate::errors::ConstEvalError;
@ -90,14 +90,14 @@ pub(crate) fn mk_eval_cx<'mir, 'tcx>(
tcx: TyCtxt<'tcx>,
root_span: Span,
param_env: ty::ParamEnv<'tcx>,
can_access_statics: CanAccessStatics,
can_access_mut_global: CanAccessMutGlobal,
) -> CompileTimeEvalContext<'mir, 'tcx> {
debug!("mk_eval_cx: {:?}", param_env);
InterpCx::new(
tcx,
root_span,
param_env,
CompileTimeInterpreter::new(can_access_statics, CheckAlignment::No),
CompileTimeInterpreter::new(can_access_mut_global, CheckAlignment::No),
)
}
@ -200,7 +200,7 @@ pub(crate) fn turn_into_const_value<'tcx>(
tcx,
tcx.def_span(key.value.instance.def_id()),
key.param_env,
CanAccessStatics::from(is_static),
CanAccessMutGlobal::from(is_static),
);
let mplace = ecx.raw_const_to_mplace(constant).expect(
@ -277,9 +277,11 @@ pub fn eval_to_allocation_raw_provider<'tcx>(
tcx,
tcx.def_span(def),
key.param_env,
// Statics (and promoteds inside statics) may access other statics, because unlike consts
// Statics (and promoteds inside statics) may access mutable global memory, because unlike consts
// they do not have to behave "as if" they were evaluated at runtime.
CompileTimeInterpreter::new(CanAccessStatics::from(is_static), CheckAlignment::Error),
// For consts however we want to ensure they behave "as if" they were evaluated at runtime,
// so we have to reject reading mutable global memory.
CompileTimeInterpreter::new(CanAccessMutGlobal::from(is_static), CheckAlignment::Error),
);
eval_in_interpreter(ecx, cid, is_static)
}
@ -358,7 +360,7 @@ pub fn const_validate_mplace<'mir, 'tcx>(
// Promoteds in statics are consts that re allowed to point to statics.
CtfeValidationMode::Const {
allow_immutable_unsafe_cell: false,
allow_static_ptrs: true,
allow_extern_static_ptrs: true,
}
}
Some(mutbl) => CtfeValidationMode::Static { mutbl }, // a `static`
@ -366,7 +368,10 @@ pub fn const_validate_mplace<'mir, 'tcx>(
// In normal `const` (not promoted), the outermost allocation is always only copied,
// so having `UnsafeCell` in there is okay despite them being in immutable memory.
let allow_immutable_unsafe_cell = cid.promoted.is_none() && !inner;
CtfeValidationMode::Const { allow_immutable_unsafe_cell, allow_static_ptrs: false }
CtfeValidationMode::Const {
allow_immutable_unsafe_cell,
allow_extern_static_ptrs: false,
}
}
};
ecx.const_validate_operand(&mplace.into(), path, &mut ref_tracking, mode)?;

38
compiler/rustc_const_eval/src/const_eval/machine.rs
View file

@ -51,13 +51,10 @@ pub struct CompileTimeInterpreter<'mir, 'tcx> {
/// The virtual call stack.
pub(super) stack: Vec<Frame<'mir, 'tcx>>,
/// We need to make sure consts never point to anything mutable, even recursively. That is
/// relied on for pattern matching on consts with references.
/// To achieve this, two pieces have to work together:
/// * Interning makes everything outside of statics immutable.
/// * Pointers to allocations inside of statics can never leak outside, to a non-static global.
/// This boolean here controls the second part.
pub(super) can_access_statics: CanAccessStatics,
/// Pattern matching on consts with references would be unsound if those references
/// could point to anything mutable. Therefore, when evaluating consts and when constructing valtrees,
/// we ensure that only immutable global memory can be accessed.
pub(super) can_access_mut_global: CanAccessMutGlobal,
/// Whether to check alignment during evaluation.
pub(super) check_alignment: CheckAlignment,
@ -73,12 +70,12 @@ pub enum CheckAlignment {
}
#[derive(Copy, Clone, PartialEq)]
pub(crate) enum CanAccessStatics {
pub(crate) enum CanAccessMutGlobal {
No,
Yes,
}
impl From<bool> for CanAccessStatics {
impl From<bool> for CanAccessMutGlobal {
fn from(value: bool) -> Self {
if value { Self::Yes } else { Self::No }
}
@ -86,13 +83,13 @@ impl From<bool> for CanAccessStatics {
impl<'mir, 'tcx> CompileTimeInterpreter<'mir, 'tcx> {
pub(crate) fn new(
can_access_statics: CanAccessStatics,
can_access_mut_global: CanAccessMutGlobal,
check_alignment: CheckAlignment,
) -> Self {
CompileTimeInterpreter {
num_evaluated_steps: 0,
stack: Vec::new(),
can_access_statics,
can_access_mut_global,
check_alignment,
}
}
@ -680,7 +677,7 @@ impl<'mir, 'tcx> interpret::Machine<'mir, 'tcx> for CompileTimeInterpreter<'mir,
machine: &Self,
alloc_id: AllocId,
alloc: ConstAllocation<'tcx>,
static_def_id: Option<DefId>,
_static_def_id: Option<DefId>,
is_write: bool,
) -> InterpResult<'tcx> {
let alloc = alloc.inner();
@ -692,22 +689,15 @@ impl<'mir, 'tcx> interpret::Machine<'mir, 'tcx> for CompileTimeInterpreter<'mir,
}
} else {
// Read access. These are usually allowed, with some exceptions.
if machine.can_access_statics == CanAccessStatics::Yes {
if machine.can_access_mut_global == CanAccessMutGlobal::Yes {
// Machine configuration allows us read from anything (e.g., `static` initializer).
Ok(())
} else if static_def_id.is_some() {
// Machine configuration does not allow us to read statics
// (e.g., `const` initializer).
// See const_eval::machine::MemoryExtra::can_access_statics for why
// this check is so important: if we could read statics, we could read pointers
// to mutable allocations *inside* statics. These allocations are not themselves
// statics, so pointers to them can get around the check in `validity.rs`.
Err(ConstEvalErrKind::ConstAccessesStatic.into())
} else if alloc.mutability == Mutability::Mut {
// Machine configuration does not allow us to read statics (e.g., `const`
// initializer).
Err(ConstEvalErrKind::ConstAccessesMutGlobal.into())
} else {
// Immutable global, this read is fine.
// But make sure we never accept a read from something mutable, that would be
// unsound. The reason is that as the content of this allocation may be different
// now and at run-time, so if we permit reading now we might return the wrong value.
assert_eq!(alloc.mutability, Mutability::Not);
Ok(())
}

61
compiler/rustc_const_eval/src/const_eval/mod.rs
View file

@ -1,12 +1,11 @@
// Not in interpret to make sure we do not use private implementation details
use crate::errors::MaxNumNodesInConstErr;
use crate::interpret::InterpCx;
use rustc_middle::mir;
use rustc_middle::mir::interpret::{EvalToValTreeResult, GlobalId};
use rustc_middle::mir::interpret::InterpErrorInfo;
use rustc_middle::query::TyCtxtAt;
use rustc_middle::ty::{self, Ty, TyCtxt};
use rustc_span::DUMMY_SP;
use rustc_middle::ty::{self, Ty};
use crate::interpret::{format_interp_error, InterpCx};
mod error;
mod eval_queries;
@ -18,56 +17,26 @@ pub use error::*;
pub use eval_queries::*;
pub use fn_queries::*;
pub use machine::*;
pub(crate) use valtrees::{const_to_valtree_inner, valtree_to_const_value};
pub(crate) use valtrees::{eval_to_valtree, valtree_to_const_value};
// We forbid type-level constants that contain more than `VALTREE_MAX_NODES` nodes.
const VALTREE_MAX_NODES: usize = 100000;
pub(crate) enum ValTreeCreationError {
NodesOverflow,
/// Values of this type, or this particular value, are not supported as valtrees.
NonSupportedType,
Other,
}
pub(crate) type ValTreeCreationResult<'tcx> = Result<ty::ValTree<'tcx>, ValTreeCreationError>;
/// Evaluates a constant and turns it into a type-level constant value.
pub(crate) fn eval_to_valtree<'tcx>(
tcx: TyCtxt<'tcx>,
param_env: ty::ParamEnv<'tcx>,
cid: GlobalId<'tcx>,
) -> EvalToValTreeResult<'tcx> {
let const_alloc = tcx.eval_to_allocation_raw(param_env.and(cid))?;
// FIXME Need to provide a span to `eval_to_valtree`
let ecx = mk_eval_cx(
tcx,
DUMMY_SP,
param_env,
// It is absolutely crucial for soundness that
// we do not read from static items or other mutable memory.
CanAccessStatics::No,
);
let place = ecx.raw_const_to_mplace(const_alloc).unwrap();
debug!(?place);
let mut num_nodes = 0;
let valtree_result = const_to_valtree_inner(&ecx, &place, &mut num_nodes);
match valtree_result {
Ok(valtree) => Ok(Some(valtree)),
Err(err) => {
let did = cid.instance.def_id();
let global_const_id = cid.display(tcx);
match err {
ValTreeCreationError::NodesOverflow => {
let span = tcx.hir().span_if_local(did);
tcx.dcx().emit_err(MaxNumNodesInConstErr { span, global_const_id });
Ok(None)
}
ValTreeCreationError::NonSupportedType | ValTreeCreationError::Other => Ok(None),
}
}
impl From<InterpErrorInfo<'_>> for ValTreeCreationError {
fn from(err: InterpErrorInfo<'_>) -> Self {
ty::tls::with(|tcx| {
bug!(
"Unexpected Undefined Behavior error during valtree construction: {}",
format_interp_error(tcx.dcx(), err),
)
})
}
}
@ -78,7 +47,7 @@ pub(crate) fn try_destructure_mir_constant_for_user_output<'tcx>(
ty: Ty<'tcx>,
) -> Option<mir::DestructuredConstant<'tcx>> {
let param_env = ty::ParamEnv::reveal_all();
let ecx = mk_eval_cx(tcx.tcx, tcx.span, param_env, CanAccessStatics::No);
let ecx = mk_eval_cx(tcx.tcx, tcx.span, param_env, CanAccessMutGlobal::No);
let op = ecx.const_val_to_op(val, ty, None).ok()?;
// We go to `usize` as we cannot allocate anything bigger anyway.

84
compiler/rustc_const_eval/src/const_eval/valtrees.rs
View file

@ -1,17 +1,20 @@
use rustc_middle::mir;
use rustc_middle::mir::interpret::{EvalToValTreeResult, GlobalId};
use rustc_middle::ty::layout::{LayoutCx, LayoutOf, TyAndLayout};
use rustc_middle::ty::{self, ScalarInt, Ty, TyCtxt};
use rustc_span::DUMMY_SP;
use rustc_target::abi::{Abi, VariantIdx};
use super::eval_queries::{mk_eval_cx, op_to_const};
use super::machine::CompileTimeEvalContext;
use super::{ValTreeCreationError, ValTreeCreationResult, VALTREE_MAX_NODES};
use crate::const_eval::CanAccessStatics;
use crate::const_eval::CanAccessMutGlobal;
use crate::errors::MaxNumNodesInConstErr;
use crate::interpret::MPlaceTy;
use crate::interpret::{
intern_const_alloc_recursive, ImmTy, Immediate, InternKind, MemPlaceMeta, MemoryKind, PlaceTy,
Projectable, Scalar,
};
use rustc_middle::mir;
use rustc_middle::ty::layout::{LayoutCx, LayoutOf, TyAndLayout};
use rustc_middle::ty::{self, ScalarInt, Ty, TyCtxt};
use rustc_span::DUMMY_SP;
use rustc_target::abi::{Abi, VariantIdx};
#[instrument(skip(ecx), level = "debug")]
fn branches<'tcx>(
@ -70,7 +73,7 @@ fn slice_branches<'tcx>(
}
#[instrument(skip(ecx), level = "debug")]
pub(crate) fn const_to_valtree_inner<'tcx>(
fn const_to_valtree_inner<'tcx>(
ecx: &CompileTimeEvalContext<'tcx, 'tcx>,
place: &MPlaceTy<'tcx>,
num_nodes: &mut usize,
@ -88,9 +91,7 @@ pub(crate) fn const_to_valtree_inner<'tcx>(
Ok(ty::ValTree::zst())
}
ty::Bool | ty::Int(_) | ty::Uint(_) | ty::Float(_) | ty::Char => {
let Ok(val) = ecx.read_immediate(place) else {
return Err(ValTreeCreationError::Other);
};
let val = ecx.read_immediate(place)?;
let val = val.to_scalar();
*num_nodes += 1;
@ -102,19 +103,17 @@ pub(crate) fn const_to_valtree_inner<'tcx>(
// equality at compile-time (see `ptr_guaranteed_cmp`).
// However we allow those that are just integers in disguise.
// First, get the pointer. Remember it might be wide!
let Ok(val) = ecx.read_immediate(place) else {
return Err(ValTreeCreationError::Other);
};
let val = ecx.read_immediate(place)?;
// We could allow wide raw pointers where both sides are integers in the future,
// but for now we reject them.
if matches!(val.layout.abi, Abi::ScalarPair(..)) {
return Err(ValTreeCreationError::Other);
return Err(ValTreeCreationError::NonSupportedType);
}
let val = val.to_scalar();
// We are in the CTFE machine, so ptr-to-int casts will fail.
// This can only be `Ok` if `val` already is an integer.
let Ok(val) = val.try_to_int() else {
return Err(ValTreeCreationError::Other);
return Err(ValTreeCreationError::NonSupportedType);
};
// It's just a ScalarInt!
Ok(ty::ValTree::Leaf(val))
@ -125,11 +124,7 @@ pub(crate) fn const_to_valtree_inner<'tcx>(
ty::FnPtr(_) => Err(ValTreeCreationError::NonSupportedType),
ty::Ref(_, _, _) => {
let Ok(derefd_place)= ecx.deref_pointer(place) else {
return Err(ValTreeCreationError::Other);
};
debug!(?derefd_place);
let derefd_place = ecx.deref_pointer(place)?;
const_to_valtree_inner(ecx, &derefd_place, num_nodes)
}
@ -153,9 +148,7 @@ pub(crate) fn const_to_valtree_inner<'tcx>(
bug!("uninhabited types should have errored and never gotten converted to valtree")
}
let Ok(variant) = ecx.read_discriminant(place) else {
return Err(ValTreeCreationError::Other);
};
let variant = ecx.read_discriminant(place)?;
branches(ecx, place, def.variant(variant).fields.len(), def.is_enum().then_some(variant), num_nodes)
}
@ -221,6 +214,47 @@ fn create_valtree_place<'tcx>(
ecx.allocate_dyn(layout, MemoryKind::Stack, meta).unwrap()
}
/// Evaluates a constant and turns it into a type-level constant value.
pub(crate) fn eval_to_valtree<'tcx>(
tcx: TyCtxt<'tcx>,
param_env: ty::ParamEnv<'tcx>,
cid: GlobalId<'tcx>,
) -> EvalToValTreeResult<'tcx> {
let const_alloc = tcx.eval_to_allocation_raw(param_env.and(cid))?;
// FIXME Need to provide a span to `eval_to_valtree`
let ecx = mk_eval_cx(
tcx,
DUMMY_SP,
param_env,
// It is absolutely crucial for soundness that
// we do not read from mutable memory.
CanAccessMutGlobal::No,
);
let place = ecx.raw_const_to_mplace(const_alloc).unwrap();
debug!(?place);
let mut num_nodes = 0;
let valtree_result = const_to_valtree_inner(&ecx, &place, &mut num_nodes);
match valtree_result {
Ok(valtree) => Ok(Some(valtree)),
Err(err) => {
let did = cid.instance.def_id();
let global_const_id = cid.display(tcx);
let span = tcx.hir().span_if_local(did);
match err {
ValTreeCreationError::NodesOverflow => {
let handled =
tcx.dcx().emit_err(MaxNumNodesInConstErr { span, global_const_id });
Err(handled.into())
}
ValTreeCreationError::NonSupportedType => Ok(None),
}
}
}
}
/// Converts a `ValTree` to a `ConstValue`, which is needed after mir
/// construction has finished.
// FIXME Merge `valtree_to_const_value` and `valtree_into_mplace` into one function
@ -253,7 +287,7 @@ pub fn valtree_to_const_value<'tcx>(
}
}
ty::Ref(_, inner_ty, _) => {
let mut ecx = mk_eval_cx(tcx, DUMMY_SP, param_env, CanAccessStatics::No);
let mut ecx = mk_eval_cx(tcx, DUMMY_SP, param_env, CanAccessMutGlobal::No);
let imm = valtree_to_ref(&mut ecx, valtree, *inner_ty);
let imm = ImmTy::from_immediate(imm, tcx.layout_of(param_env_ty).unwrap());
op_to_const(&ecx, &imm.into(), /* for diagnostics */ false)
@ -280,7 +314,7 @@ pub fn valtree_to_const_value<'tcx>(
bug!("could not find non-ZST field during in {layout:#?}");
}
let mut ecx = mk_eval_cx(tcx, DUMMY_SP, param_env, CanAccessStatics::No);
let mut ecx = mk_eval_cx(tcx, DUMMY_SP, param_env, CanAccessMutGlobal::No);
// Need to create a place for this valtree.
let place = create_valtree_place(&mut ecx, layout, valtree);

18
compiler/rustc_const_eval/src/errors.rs
View file

@ -56,23 +56,11 @@ pub(crate) struct UnstableInStable {
#[derive(Diagnostic)]
#[diag(const_eval_thread_local_access, code = E0625)]
pub(crate) struct NonConstOpErr {
pub(crate) struct ThreadLocalAccessErr {
#[primary_span]
pub span: Span,
}
#[derive(Diagnostic)]
#[diag(const_eval_static_access, code = E0013)]
#[help]
pub(crate) struct StaticAccessErr {
#[primary_span]
pub span: Span,
pub kind: ConstContext,
#[note(const_eval_teach_note)]
#[help(const_eval_teach_help)]
pub teach: Option<()>,
}
#[derive(Diagnostic)]
#[diag(const_eval_raw_ptr_to_int)]
#[note]
@ -623,6 +611,8 @@ impl<'tcx> ReportErrorExt for ValidationErrorInfo<'tcx> {
PointerAsInt { .. } => const_eval_validation_pointer_as_int,
PartialPointer => const_eval_validation_partial_pointer,
ConstRefToMutable => const_eval_validation_const_ref_to_mutable,
ConstRefToExtern => const_eval_validation_const_ref_to_extern,
MutableRefInConst => const_eval_validation_mutable_ref_in_const,
MutableRefToImmutable => const_eval_validation_mutable_ref_to_immutable,
NullFnPtr => const_eval_validation_null_fn_ptr,
@ -777,6 +767,8 @@ impl<'tcx> ReportErrorExt for ValidationErrorInfo<'tcx> {
NullPtr { .. }
| PtrToStatic { .. }
| MutableRefInConst
| ConstRefToMutable
| ConstRefToExtern
| MutableRefToImmutable
| NullFnPtr
| NeverVal

42
compiler/rustc_const_eval/src/interpret/eval_context.rs
View file

@ -4,6 +4,7 @@ use std::{fmt, mem};
use either::{Either, Left, Right};
use hir::CRATE_HIR_ID;
use rustc_errors::DiagCtxt;
use rustc_hir::{self as hir, def_id::DefId, definitions::DefPathData};
use rustc_index::IndexVec;
use rustc_middle::mir;
@ -430,6 +431,26 @@ pub(super) fn from_known_layout<'tcx>(
}
}
/// Turn the given error into a human-readable string. Expects the string to be printed, so if
/// `RUSTC_CTFE_BACKTRACE` is set this will show a backtrace of the rustc internals that
/// triggered the error.
///
/// This is NOT the preferred way to render an error; use `report` from `const_eval` instead.
/// However, this is useful when error messages appear in ICEs.
pub fn format_interp_error<'tcx>(dcx: &DiagCtxt, e: InterpErrorInfo<'tcx>) -> String {
let (e, backtrace) = e.into_parts();
backtrace.print_backtrace();
// FIXME(fee1-dead), HACK: we want to use the error as title therefore we can just extract the
// label and arguments from the InterpError.
#[allow(rustc::untranslatable_diagnostic)]
let mut diag = dcx.struct_allow("");
let msg = e.diagnostic_message();
e.add_args(dcx, &mut diag);
let s = dcx.eagerly_translate_to_string(msg, diag.args());
diag.cancel();
s
}
impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
pub fn new(
tcx: TyCtxt<'tcx>,
@ -462,27 +483,6 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
.map_or(CRATE_HIR_ID, |def_id| self.tcx.local_def_id_to_hir_id(def_id))
}
/// Turn the given error into a human-readable string. Expects the string to be printed, so if
/// `RUSTC_CTFE_BACKTRACE` is set this will show a backtrace of the rustc internals that
/// triggered the error.
///
/// This is NOT the preferred way to render an error; use `report` from `const_eval` instead.
/// However, this is useful when error messages appear in ICEs.
pub fn format_error(&self, e: InterpErrorInfo<'tcx>) -> String {
let (e, backtrace) = e.into_parts();
backtrace.print_backtrace();
// FIXME(fee1-dead), HACK: we want to use the error as title therefore we can just extract the
// label and arguments from the InterpError.
let dcx = self.tcx.dcx();
#[allow(rustc::untranslatable_diagnostic)]
let mut diag = dcx.struct_allow("");
let msg = e.diagnostic_message();
e.add_args(dcx, &mut diag);
let s = dcx.eagerly_translate_to_string(msg, diag.args());
diag.cancel();
s
}
#[inline(always)]
pub(crate) fn stack(&self) -> &[Frame<'mir, 'tcx, M::Provenance, M::FrameExtra>] {
M::stack(self)

2
compiler/rustc_const_eval/src/interpret/mod.rs
View file

@ -20,7 +20,7 @@ mod visitor;
pub use rustc_middle::mir::interpret::*; // have all the `interpret` symbols in one place: here
pub use self::eval_context::{Frame, FrameInfo, InterpCx, StackPopCleanup};
pub use self::eval_context::{format_interp_error, Frame, FrameInfo, InterpCx, StackPopCleanup};
pub use self::intern::{
intern_const_alloc_for_constprop, intern_const_alloc_recursive, InternKind,
};

100
compiler/rustc_const_eval/src/interpret/validity.rs
View file

@ -27,8 +27,9 @@ use rustc_target::abi::{
use std::hash::Hash;
use super::{
AllocId, CheckInAllocMsg, GlobalAlloc, ImmTy, Immediate, InterpCx, InterpResult, MPlaceTy,
Machine, MemPlaceMeta, OpTy, Pointer, Projectable, Scalar, ValueVisitor,
format_interp_error, AllocId, CheckInAllocMsg, GlobalAlloc, ImmTy, Immediate, InterpCx,
InterpResult, MPlaceTy, Machine, MemPlaceMeta, OpTy, Pointer, Projectable, Scalar,
ValueVisitor,
};
// for the validation errors
@ -132,8 +133,7 @@ pub enum CtfeValidationMode {
/// `allow_immutable_unsafe_cell` says whether we allow `UnsafeCell` in immutable memory (which is the
/// case for the top-level allocation of a `const`, where this is fine because the allocation will be
/// copied at each use site).
/// `allow_static_ptrs` says if pointers to statics are permitted (which is the case for promoteds in statics).
Const { allow_immutable_unsafe_cell: bool, allow_static_ptrs: bool },
Const { allow_immutable_unsafe_cell: bool, allow_extern_static_ptrs: bool },
}
impl CtfeValidationMode {
@ -146,13 +146,6 @@ impl CtfeValidationMode {
}
}
fn allow_static_ptrs(self) -> bool {
match self {
CtfeValidationMode::Static { .. } => true, // statics can point to statics
CtfeValidationMode::Const { allow_static_ptrs, .. } => allow_static_ptrs,
}
}
fn may_contain_mutable_ref(self) -> bool {
match self {
CtfeValidationMode::Static { mutbl } => mutbl == Mutability::Mut,
@ -468,53 +461,59 @@ impl<'rt, 'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> ValidityVisitor<'rt, 'mir, '
// Special handling for pointers to statics (irrespective of their type).
assert!(!self.ecx.tcx.is_thread_local_static(did));
assert!(self.ecx.tcx.is_static(did));
if self.ctfe_mode.is_some_and(|c| !c.allow_static_ptrs()) {
// See const_eval::machine::MemoryExtra::can_access_statics for why
// this check is so important.
// This check is reachable when the const just referenced the static,
// but never read it (so we never entered `before_access_global`).
throw_validation_failure!(self.path, PtrToStatic { ptr_kind });
}
let is_mut =
matches!(self.ecx.tcx.def_kind(did), DefKind::Static(Mutability::Mut))
|| !self
.ecx
.tcx
.type_of(did)
.no_bound_vars()
.expect("statics should not have generic parameters")
.is_freeze(*self.ecx.tcx, ty::ParamEnv::reveal_all());
// Mutability check.
if ptr_expected_mutbl == Mutability::Mut {
if matches!(
self.ecx.tcx.def_kind(did),
DefKind::Static(Mutability::Not)
) && self
.ecx
.tcx
.type_of(did)
.no_bound_vars()
.expect("statics should not have generic parameters")
.is_freeze(*self.ecx.tcx, ty::ParamEnv::reveal_all())
{
if !is_mut {
throw_validation_failure!(self.path, MutableRefToImmutable);
}
}
// We skip recursively checking other statics. These statics must be sound by
// themselves, and the only way to get broken statics here is by using
// unsafe code.
// The reasons we don't check other statics is twofold. For one, in all
// sound cases, the static was already validated on its own, and second, we
// trigger cycle errors if we try to compute the value of the other static
// and that static refers back to us.
// We might miss const-invalid data,
// but things are still sound otherwise (in particular re: consts
// referring to statics).
return Ok(());
match self.ctfe_mode {
Some(CtfeValidationMode::Static { .. }) => {
// We skip recursively checking other statics. These statics must be sound by
// themselves, and the only way to get broken statics here is by using
// unsafe code.
// The reasons we don't check other statics is twofold. For one, in all
// sound cases, the static was already validated on its own, and second, we
// trigger cycle errors if we try to compute the value of the other static
// and that static refers back to us.
// This could miss some UB, but that's fine.
return Ok(());
}
Some(CtfeValidationMode::Const {
allow_extern_static_ptrs, ..
}) => {
// For consts on the other hand we have to recursively check;
// pattern matching assumes a valid value. However we better make
// sure this is not mutable.
if is_mut {
throw_validation_failure!(self.path, ConstRefToMutable);
}
if self.ecx.tcx.is_foreign_item(did) {
if !allow_extern_static_ptrs {
throw_validation_failure!(self.path, ConstRefToExtern);
} else {
// We can't validate this...
return Ok(());
}
}
}
None => {}
}
}
GlobalAlloc::Memory(alloc) => {
if alloc.inner().mutability == Mutability::Mut
&& matches!(self.ctfe_mode, Some(CtfeValidationMode::Const { .. }))
{
// This is impossible: this can only be some inner allocation of a
// `static mut` (everything else either hits the `GlobalAlloc::Static`
// case or is interned immutably). To get such a pointer we'd have to
// load it from a static, but such loads lead to a CTFE error.
span_bug!(
self.ecx.tcx.span,
"encountered reference to mutable memory inside a `const`"
);
throw_validation_failure!(self.path, ConstRefToMutable);
}
if ptr_expected_mutbl == Mutability::Mut
&& alloc.inner().mutability == Mutability::Not
@ -993,7 +992,10 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
// Complain about any other kind of error -- those are bad because we'd like to
// report them in a way that shows *where* in the value the issue lies.
Err(err) => {
bug!("Unexpected error during validation: {}", self.format_error(err));
bug!(
"Unexpected error during validation: {}",
format_interp_error(self.tcx.dcx(), err)
);
}
}
}

17
compiler/rustc_const_eval/src/transform/check_consts/ops.rs
View file

@ -580,16 +580,21 @@ impl<'tcx> NonConstOp<'tcx> for StaticAccess {
if let hir::ConstContext::Static(_) = ccx.const_kind() {
Status::Allowed
} else {
Status::Forbidden
Status::Unstable(sym::const_refs_to_static)
}
}
fn build_error(&self, ccx: &ConstCx<'_, 'tcx>, span: Span) -> DiagnosticBuilder<'tcx> {
ccx.dcx().create_err(errors::StaticAccessErr {
let mut err = feature_err(
&ccx.tcx.sess,
sym::const_refs_to_static,
span,
kind: ccx.const_kind(),
teach: ccx.tcx.sess.teach(E0013).then_some(()),
})
format!("referencing statics in {}s is unstable", ccx.const_kind(),),
);
err
.note("`static` and `const` variables can refer to other `const` variables. A `const` variable, however, cannot refer to a `static` variable.")
.help("to fix this, the value can be extracted to a `const` and then used.");
err
}
}
@ -598,7 +603,7 @@ impl<'tcx> NonConstOp<'tcx> for StaticAccess {
pub struct ThreadLocalAccess;
impl<'tcx> NonConstOp<'tcx> for ThreadLocalAccess {
fn build_error(&self, ccx: &ConstCx<'_, 'tcx>, span: Span) -> DiagnosticBuilder<'tcx> {
ccx.dcx().create_err(errors::NonConstOpErr { span })
ccx.dcx().create_err(errors::ThreadLocalAccessErr { span })
}
}

4
compiler/rustc_const_eval/src/util/caller_location.rs
View file

@ -6,7 +6,7 @@ use rustc_middle::ty::layout::LayoutOf;
use rustc_span::symbol::Symbol;
use rustc_type_ir::Mutability;
use crate::const_eval::{mk_eval_cx, CanAccessStatics, CompileTimeEvalContext};
use crate::const_eval::{mk_eval_cx, CanAccessMutGlobal, CompileTimeEvalContext};
use crate::interpret::*;
/// Allocate a `const core::panic::Location` with the provided filename and line/column numbers.
@ -57,7 +57,7 @@ pub(crate) fn const_caller_location_provider(
col: u32,
) -> mir::ConstValue<'_> {
trace!("const_caller_location: {}:{}:{}", file, line, col);
let mut ecx = mk_eval_cx(tcx.tcx, tcx.span, ty::ParamEnv::reveal_all(), CanAccessStatics::No);
let mut ecx = mk_eval_cx(tcx.tcx, tcx.span, ty::ParamEnv::reveal_all(), CanAccessMutGlobal::No);
let loc_place = alloc_caller_location(&mut ecx, file, line, col);
if intern_const_alloc_recursive(&mut ecx, InternKind::Constant, &loc_place).is_err() {

4
compiler/rustc_const_eval/src/util/check_validity_requirement.rs
View file

@ -2,7 +2,7 @@ use rustc_middle::ty::layout::{LayoutCx, LayoutError, LayoutOf, TyAndLayout, Val
use rustc_middle::ty::{ParamEnv, ParamEnvAnd, Ty, TyCtxt};
use rustc_target::abi::{Abi, FieldsShape, Scalar, Variants};
use crate::const_eval::{CanAccessStatics, CheckAlignment, CompileTimeInterpreter};
use crate::const_eval::{CanAccessMutGlobal, CheckAlignment, CompileTimeInterpreter};
use crate::interpret::{InterpCx, MemoryKind, OpTy};
/// Determines if this type permits "raw" initialization by just transmuting some memory into an
@ -44,7 +44,7 @@ fn might_permit_raw_init_strict<'tcx>(
tcx: TyCtxt<'tcx>,
kind: ValidityRequirement,
) -> Result<bool, &'tcx LayoutError<'tcx>> {
let machine = CompileTimeInterpreter::new(CanAccessStatics::No, CheckAlignment::Error);
let machine = CompileTimeInterpreter::new(CanAccessMutGlobal::No, CheckAlignment::Error);
let mut cx = InterpCx::new(tcx, rustc_span::DUMMY_SP, ParamEnv::reveal_all(), machine);

4
compiler/rustc_error_codes/src/error_codes/E0013.md
View file

@ -1,9 +1,11 @@
#### Note: this error code is no longer emitted by the compiler
Static and const variables can refer to other const variables. But a const
variable cannot refer to a static variable.
Erroneous code example:
```compile_fail,E0013
```compile_fail,E0658
static X: i32 = 42;
const Y: i32 = X;
```

2
compiler/rustc_feature/src/unstable.rs
View file

@ -409,6 +409,8 @@ declare_features! (
(unstable, const_precise_live_drops, "1.46.0", Some(73255)),
/// Allows references to types with interior mutability within constants
(unstable, const_refs_to_cell, "1.51.0", Some(80384)),
/// Allows creating pointers and references to `static` items in constants.
(unstable, const_refs_to_static, "CURRENT_RUSTC_VERSION", Some(119618)),
/// Allows `impl const Trait for T` syntax.
(unstable, const_trait_impl, "1.42.0", Some(67792)),
/// Allows the `?` operator in const contexts.

2
compiler/rustc_middle/src/mir/interpret/error.rs
View file

@ -417,6 +417,8 @@ pub enum ValidationErrorKind<'tcx> {
PtrToUninhabited { ptr_kind: PointerKind, ty: Ty<'tcx> },
PtrToStatic { ptr_kind: PointerKind },
MutableRefInConst,
ConstRefToMutable,
ConstRefToExtern,
MutableRefToImmutable,
UnsafeCellInImmutable,
NullFnPtr,

7
compiler/rustc_mir_transform/src/const_prop_lint.rs
View file

@ -3,8 +3,9 @@
use std::fmt::Debug;
use rustc_const_eval::interpret::{ImmTy, Projectable};
use rustc_const_eval::interpret::{InterpCx, InterpResult, Scalar};
use rustc_const_eval::interpret::{
format_interp_error, ImmTy, InterpCx, InterpResult, Projectable, Scalar,
};
use rustc_data_structures::fx::FxHashSet;
use rustc_hir::def::DefKind;
use rustc_hir::HirId;
@ -246,7 +247,7 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> {
assert!(
!error.kind().formatted_string(),
"const-prop encountered formatting error: {}",
self.ecx.format_error(error),
format_interp_error(self.ecx.tcx.dcx(), error),
);
None
}

1
compiler/rustc_span/src/symbol.rs
View file

@ -582,6 +582,7 @@ symbols! {
const_raw_ptr_deref,
const_raw_ptr_to_usize_cast,
const_refs_to_cell,
const_refs_to_static,
const_trait,
const_trait_bound_opt_out,
const_trait_impl,

6
src/tools/miri/src/diagnostics.rs
View file

@ -290,7 +290,7 @@ pub fn report_error<'tcx, 'mir>(
) =>
{
ecx.handle_ice(); // print interpreter backtrace
bug!("This validation error should be impossible in Miri: {}", ecx.format_error(e));
bug!("This validation error should be impossible in Miri: {}", format_interp_error(ecx.tcx.dcx(), e));
}
UndefinedBehavior(_) => "Undefined Behavior",
ResourceExhaustion(_) => "resource exhaustion",
@ -304,7 +304,7 @@ pub fn report_error<'tcx, 'mir>(
) => "post-monomorphization error",
_ => {
ecx.handle_ice(); // print interpreter backtrace
bug!("This error should be impossible in Miri: {}", ecx.format_error(e));
bug!("This error should be impossible in Miri: {}", format_interp_error(ecx.tcx.dcx(), e));
}
};
#[rustfmt::skip]
@ -370,7 +370,7 @@ pub fn report_error<'tcx, 'mir>(
_ => {}
}
msg.insert(0, ecx.format_error(e));
msg.insert(0, format_interp_error(ecx.tcx.dcx(), e));
report_msg(
DiagLevel::Error,

6
tests/ui/asm/aarch64/type-check-4.rs
View file

@ -23,10 +23,10 @@ const fn const_bar<T>(x: T) -> T {
x
}
global_asm!("{}", const S);
//~^ ERROR constants cannot refer to statics
//~^ ERROR referencing statics
global_asm!("{}", const const_foo(0));
global_asm!("{}", const const_foo(S));
//~^ ERROR constants cannot refer to statics
//~^ ERROR referencing statics
global_asm!("{}", const const_bar(0));
global_asm!("{}", const const_bar(S));
//~^ ERROR constants cannot refer to statics
//~^ ERROR referencing statics

26
tests/ui/asm/aarch64/type-check-4.stderr
View file

@ -1,27 +1,39 @@
error[E0013]: constants cannot refer to statics
error[E0658]: referencing statics in constants is unstable
--> $DIR/type-check-4.rs:25:25
|
LL | global_asm!("{}", const S);
| ^
|
= help: consider extracting the value of the `static` to a `const`, and referring to that
= note: see issue #119618 <https://github.com/rust-lang/rust/issues/119618> for more information
= help: add `#![feature(const_refs_to_static)]` to the crate attributes to enable
= note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
= note: `static` and `const` variables can refer to other `const` variables. A `const` variable, however, cannot refer to a `static` variable.
= help: to fix this, the value can be extracted to a `const` and then used.
error[E0013]: constants cannot refer to statics
error[E0658]: referencing statics in constants is unstable
--> $DIR/type-check-4.rs:28:35
|
LL | global_asm!("{}", const const_foo(S));
| ^
|
= help: consider extracting the value of the `static` to a `const`, and referring to that
= note: see issue #119618 <https://github.com/rust-lang/rust/issues/119618> for more information
= help: add `#![feature(const_refs_to_static)]` to the crate attributes to enable
= note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
= note: `static` and `const` variables can refer to other `const` variables. A `const` variable, however, cannot refer to a `static` variable.
= help: to fix this, the value can be extracted to a `const` and then used.
error[E0013]: constants cannot refer to statics
error[E0658]: referencing statics in constants is unstable
--> $DIR/type-check-4.rs:31:35
|
LL | global_asm!("{}", const const_bar(S));
| ^
|
= help: consider extracting the value of the `static` to a `const`, and referring to that
= note: see issue #119618 <https://github.com/rust-lang/rust/issues/119618> for more information
= help: add `#![feature(const_refs_to_static)]` to the crate attributes to enable
= note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
= note: `static` and `const` variables can refer to other `const` variables. A `const` variable, however, cannot refer to a `static` variable.
= help: to fix this, the value can be extracted to a `const` and then used.
error: aborting due to 3 previous errors
For more information about this error, try `rustc --explain E0013`.
For more information about this error, try `rustc --explain E0658`.

6
tests/ui/asm/x86_64/type-check-4.rs
View file

@ -19,10 +19,10 @@ const fn const_bar<T>(x: T) -> T {
x
}
global_asm!("{}", const S);
//~^ ERROR constants cannot refer to statics
//~^ ERROR referencing statics
global_asm!("{}", const const_foo(0));
global_asm!("{}", const const_foo(S));
//~^ ERROR constants cannot refer to statics
//~^ ERROR referencing statics
global_asm!("{}", const const_bar(0));
global_asm!("{}", const const_bar(S));
//~^ ERROR constants cannot refer to statics
//~^ ERROR referencing statics

26
tests/ui/asm/x86_64/type-check-4.stderr
View file

@ -1,27 +1,39 @@
error[E0013]: constants cannot refer to statics
error[E0658]: referencing statics in constants is unstable
--> $DIR/type-check-4.rs:21:25
|
LL | global_asm!("{}", const S);
| ^
|
= help: consider extracting the value of the `static` to a `const`, and referring to that
= note: see issue #119618 <https://github.com/rust-lang/rust/issues/119618> for more information
= help: add `#![feature(const_refs_to_static)]` to the crate attributes to enable
= note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
= note: `static` and `const` variables can refer to other `const` variables. A `const` variable, however, cannot refer to a `static` variable.
= help: to fix this, the value can be extracted to a `const` and then used.
error[E0013]: constants cannot refer to statics
error[E0658]: referencing statics in constants is unstable
--> $DIR/type-check-4.rs:24:35
|
LL | global_asm!("{}", const const_foo(S));
| ^
|
= help: consider extracting the value of the `static` to a `const`, and referring to that
= note: see issue #119618 <https://github.com/rust-lang/rust/issues/119618> for more information
= help: add `#![feature(const_refs_to_static)]` to the crate attributes to enable
= note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
= note: `static` and `const` variables can refer to other `const` variables. A `const` variable, however, cannot refer to a `static` variable.
= help: to fix this, the value can be extracted to a `const` and then used.
error[E0013]: constants cannot refer to statics
error[E0658]: referencing statics in constants is unstable
--> $DIR/type-check-4.rs:27:35
|
LL | global_asm!("{}", const const_bar(S));
| ^
|
= help: consider extracting the value of the `static` to a `const`, and referring to that
= note: see issue #119618 <https://github.com/rust-lang/rust/issues/119618> for more information
= help: add `#![feature(const_refs_to_static)]` to the crate attributes to enable
= note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
= note: `static` and `const` variables can refer to other `const` variables. A `const` variable, however, cannot refer to a `static` variable.
= help: to fix this, the value can be extracted to a `const` and then used.
error: aborting due to 3 previous errors
For more information about this error, try `rustc --explain E0013`.
For more information about this error, try `rustc --explain E0658`.

10
tests/ui/const_prop/const-prop-read-static-in-const.rs
View file

@ -1,10 +0,0 @@
// compile-flags: -Zunleash-the-miri-inside-of-you
#![allow(dead_code)]
const TEST: u8 = MY_STATIC; //~ ERROR constant
static MY_STATIC: u8 = 4;
fn main() {
}

17
tests/ui/const_prop/const-prop-read-static-in-const.stderr
View file

@ -1,17 +0,0 @@
error[E0080]: evaluation of constant value failed
--> $DIR/const-prop-read-static-in-const.rs:5:18
|
LL | const TEST: u8 = MY_STATIC;
| ^^^^^^^^^ constant accesses static
warning: skipping const checks
|
help: skipping check that does not even have a feature gate
--> $DIR/const-prop-read-static-in-const.rs:5:18
|
LL | const TEST: u8 = MY_STATIC;
| ^^^^^^^^^
error: aborting due to 1 previous error; 1 warning emitted
For more information about this error, try `rustc --explain E0080`.

4
tests/ui/consts/const-fn-not-safe-for-const.rs
View file

@ -18,12 +18,12 @@ static Y: u32 = 0;
const fn get_Y() -> u32 {
Y
//~^ ERROR E0013
//~^ ERROR referencing statics in constant functions
}
const fn get_Y_addr() -> &'static u32 {
&Y
//~^ ERROR E0013
//~^ ERROR referencing statics in constant functions
}
const fn get() -> u32 {

20
tests/ui/consts/const-fn-not-safe-for-const.stderr
View file

@ -6,23 +6,31 @@ LL | random()
|
= note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
error[E0013]: constant functions cannot refer to statics
error[E0658]: referencing statics in constant functions is unstable
--> $DIR/const-fn-not-safe-for-const.rs:20:5
|
LL | Y
| ^
|
= help: consider extracting the value of the `static` to a `const`, and referring to that
= note: see issue #119618 <https://github.com/rust-lang/rust/issues/119618> for more information
= help: add `#![feature(const_refs_to_static)]` to the crate attributes to enable
= note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
= note: `static` and `const` variables can refer to other `const` variables. A `const` variable, however, cannot refer to a `static` variable.
= help: to fix this, the value can be extracted to a `const` and then used.
error[E0013]: constant functions cannot refer to statics
error[E0658]: referencing statics in constant functions is unstable
--> $DIR/const-fn-not-safe-for-const.rs:25:6
|
LL | &Y
| ^
|
= help: consider extracting the value of the `static` to a `const`, and referring to that
= note: see issue #119618 <https://github.com/rust-lang/rust/issues/119618> for more information
= help: add `#![feature(const_refs_to_static)]` to the crate attributes to enable
= note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
= note: `static` and `const` variables can refer to other `const` variables. A `const` variable, however, cannot refer to a `static` variable.
= help: to fix this, the value can be extracted to a `const` and then used.
error: aborting due to 3 previous errors
Some errors have detailed explanations: E0013, E0015.
For more information about an error, try `rustc --explain E0013`.
Some errors have detailed explanations: E0015, E0658.
For more information about an error, try `rustc --explain E0015`.

19
tests/ui/consts/const_refs_to_static.rs Normal file
View file

@ -0,0 +1,19 @@
// run-pass
#![feature(const_refs_to_static)]
static S: i32 = 0;
static mut S_MUT: i32 = 0;
const C1: &i32 = &S;
#[allow(unused)]
const C1_READ: () = {
assert!(*C1 == 0);
};
const C2: *const i32 = unsafe { std::ptr::addr_of!(S_MUT) };
fn main() {
assert_eq!(*C1, 0);
assert_eq!(unsafe { *C2 }, 0);
// Computing this pattern will read from an immutable static. That's fine.
assert!(matches!(&0, C1));
}

21
tests/ui/consts/const_refs_to_static_fail.rs Normal file
View file

@ -0,0 +1,21 @@
// normalize-stderr-test "(the raw bytes of the constant) \(size: [0-9]*, align: [0-9]*\)" -> "$1 (size: $$SIZE, align: $$ALIGN)"
// normalize-stderr-test "([0-9a-f][0-9a-f] |╾─*ALLOC[0-9]+(\+[a-z0-9]+)?(<imm>)?─*╼ )+ *│.*" -> "HEX_DUMP"
#![feature(const_refs_to_static, const_mut_refs, sync_unsafe_cell)]
use std::cell::SyncUnsafeCell;
static S: SyncUnsafeCell<i32> = SyncUnsafeCell::new(0);
static mut S_MUT: i32 = 0;
const C1: &SyncUnsafeCell<i32> = &S; //~ERROR undefined behavior
//~| encountered reference to mutable memory
const C1_READ: () = unsafe {
assert!(*C1.get() == 0);
};
const C2: *const i32 = unsafe { std::ptr::addr_of!(S_MUT) };
const C2_READ: () = unsafe {
assert!(*C2 == 0); //~ERROR evaluation of constant value failed
//~^ constant accesses mutable global memory
};
fn main() {
}

26
tests/ui/consts/const_refs_to_static_fail.stderr Normal file
View file

@ -0,0 +1,26 @@
error[E0080]: it is undefined behavior to use this value
--> $DIR/const_refs_to_static_fail.rs:9:1
|
LL | const C1: &SyncUnsafeCell<i32> = &S;
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered reference to mutable memory in `const`
|
= note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
= note: the raw bytes of the constant (size: $SIZE, align: $ALIGN) {
HEX_DUMP
}
note: erroneous constant encountered
--> $DIR/const_refs_to_static_fail.rs:12:14
|
LL | assert!(*C1.get() == 0);
| ^^
error[E0080]: evaluation of constant value failed
--> $DIR/const_refs_to_static_fail.rs:16:13
|
LL | assert!(*C2 == 0);
| ^^^ constant accesses mutable global memory
error: aborting due to 2 previous errors
For more information about this error, try `rustc --explain E0080`.

51
tests/ui/consts/const_refs_to_static_fail_invalid.rs Normal file
View file

@ -0,0 +1,51 @@
// normalize-stderr-test "(the raw bytes of the constant) \(size: [0-9]*, align: [0-9]*\)" -> "$1 (size: $$SIZE, align: $$ALIGN)"
// normalize-stderr-test "([0-9a-f][0-9a-f] |╾─*ALLOC[0-9]+(\+[a-z0-9]+)?(<imm>)?─*╼ )+ *│.*" -> "HEX_DUMP"
#![feature(const_refs_to_static)]
fn invalid() {
static S: i8 = 10;
const C: &bool = unsafe { std::mem::transmute(&S) };
//~^ERROR: undefined behavior
//~| expected a boolean
// This must be rejected here (or earlier), since it's not a valid `&bool`.
match &true {
C => {} //~ERROR: could not evaluate constant pattern
_ => {}
}
}
fn extern_() {
extern "C" {
static S: i8;
}
const C: &i8 = unsafe { &S };
//~^ERROR: undefined behavior
//~| `extern` static
// This must be rejected here (or earlier), since the pattern cannot be read.
match &0 {
C => {} //~ERROR: could not evaluate constant pattern
_ => {}
}
}
fn mutable() {
static mut S_MUT: i32 = 0;
const C: &i32 = unsafe { &S_MUT };
//~^ERROR: undefined behavior
//~| encountered reference to mutable memory
//~| WARN shared reference of mutable static is discouraged
// This *must not build*, the constant we are matching against
// could change its value!
match &42 {
C => {}, //~ERROR: could not evaluate constant pattern
_ => {},
}
}
fn main() {}

69
tests/ui/consts/const_refs_to_static_fail_invalid.stderr Normal file
View file

@ -0,0 +1,69 @@
warning: shared reference of mutable static is discouraged
--> $DIR/const_refs_to_static_fail_invalid.rs:38:30
|
LL | const C: &i32 = unsafe { &S_MUT };
| ^^^^^^ shared reference of mutable static
|
= note: for more information, see issue #114447 <https://github.com/rust-lang/rust/issues/114447>
= note: reference of mutable static is a hard error from 2024 edition
= note: mutable statics can be written to by multiple threads: aliasing violations or data races will cause undefined behavior
= note: `#[warn(static_mut_ref)]` on by default
help: shared references are dangerous since if there's any kind of mutation of that static while the reference lives, that's UB; use `addr_of!` instead to create a raw pointer
|
LL | const C: &i32 = unsafe { addr_of!(S_MUT) };
| ~~~~~~~~~~~~~~~
error[E0080]: it is undefined behavior to use this value
--> $DIR/const_refs_to_static_fail_invalid.rs:8:5
|
LL | const C: &bool = unsafe { std::mem::transmute(&S) };
| ^^^^^^^^^^^^^^ constructing invalid value at .<deref>: encountered 0x0a, but expected a boolean
|
= note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
= note: the raw bytes of the constant (size: $SIZE, align: $ALIGN) {
HEX_DUMP
}
error: could not evaluate constant pattern
--> $DIR/const_refs_to_static_fail_invalid.rs:14:9
|
LL | C => {}
| ^
error[E0080]: it is undefined behavior to use this value
--> $DIR/const_refs_to_static_fail_invalid.rs:24:5
|
LL | const C: &i8 = unsafe { &S };
| ^^^^^^^^^^^^ constructing invalid value: encountered reference to `extern` static in `const`
|
= note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
= note: the raw bytes of the constant (size: $SIZE, align: $ALIGN) {
HEX_DUMP
}
error: could not evaluate constant pattern
--> $DIR/const_refs_to_static_fail_invalid.rs:30:9
|
LL | C => {}
| ^
error[E0080]: it is undefined behavior to use this value
--> $DIR/const_refs_to_static_fail_invalid.rs:38:5
|
LL | const C: &i32 = unsafe { &S_MUT };
| ^^^^^^^^^^^^^ constructing invalid value: encountered reference to mutable memory in `const`
|
= note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
= note: the raw bytes of the constant (size: $SIZE, align: $ALIGN) {
HEX_DUMP
}
error: could not evaluate constant pattern
--> $DIR/const_refs_to_static_fail_invalid.rs:46:9
|
LL | C => {},
| ^
error: aborting due to 6 previous errors; 1 warning emitted
For more information about this error, try `rustc --explain E0080`.

6
tests/ui/consts/issue-17718-const-bad-values.rs
View file

@ -3,8 +3,8 @@ const C1: &'static mut [usize] = &mut [];
static mut S: usize = 3;
const C2: &'static mut usize = unsafe { &mut S };
//~^ WARN mutable reference of mutable static is discouraged [static_mut_ref]
//~^^ ERROR: constants cannot refer to statics
//~| ERROR: constants cannot refer to statics
//~^ ERROR: referencing statics in constants
//~| ERROR: referencing statics in constants
//~| WARN mutable reference of mutable static is discouraged [static_mut_ref]
fn main() {}

20
tests/ui/consts/issue-17718-const-bad-values.stderr
View file

@ -19,24 +19,32 @@ error[E0764]: mutable references are not allowed in the final value of constants
LL | const C1: &'static mut [usize] = &mut [];
| ^^^^^^^
error[E0013]: constants cannot refer to statics
error[E0658]: referencing statics in constants is unstable
--> $DIR/issue-17718-const-bad-values.rs:5:46
|
LL | const C2: &'static mut usize = unsafe { &mut S };
| ^
|
= help: consider extracting the value of the `static` to a `const`, and referring to that
= note: see issue #119618 <https://github.com/rust-lang/rust/issues/119618> for more information
= help: add `#![feature(const_refs_to_static)]` to the crate attributes to enable
= note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
= note: `static` and `const` variables can refer to other `const` variables. A `const` variable, however, cannot refer to a `static` variable.
= help: to fix this, the value can be extracted to a `const` and then used.
error[E0013]: constants cannot refer to statics
error[E0658]: referencing statics in constants is unstable
--> $DIR/issue-17718-const-bad-values.rs:5:46
|
LL | const C2: &'static mut usize = unsafe { &mut S };
| ^
|
= help: consider extracting the value of the `static` to a `const`, and referring to that
= note: see issue #119618 <https://github.com/rust-lang/rust/issues/119618> for more information
= help: add `#![feature(const_refs_to_static)]` to the crate attributes to enable
= note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
= note: `static` and `const` variables can refer to other `const` variables. A `const` variable, however, cannot refer to a `static` variable.
= help: to fix this, the value can be extracted to a `const` and then used.
= note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
error: aborting due to 3 previous errors; 1 warning emitted
Some errors have detailed explanations: E0013, E0764.
For more information about an error, try `rustc --explain E0013`.
Some errors have detailed explanations: E0658, E0764.
For more information about an error, try `rustc --explain E0658`.

6
tests/ui/consts/issue-17718-references.rs
View file

@ -6,18 +6,18 @@ const C: usize = 1;
static S: usize = 1;
const T1: &'static usize = &C;
const T2: &'static usize = &S; //~ ERROR: constants cannot refer to statics
const T2: &'static usize = &S; //~ ERROR: referencing statics in constants
static T3: &'static usize = &C;
static T4: &'static usize = &S;
const T5: usize = C;
const T6: usize = S; //~ ERROR: constants cannot refer to statics
const T6: usize = S; //~ ERROR: referencing statics in constants
static T7: usize = C;
static T8: usize = S;
const T9: Struct = Struct { a: C };
const T10: Struct = Struct { a: S };
//~^ ERROR: constants cannot refer to statics
//~^ ERROR: referencing statics in constants
static T11: Struct = Struct { a: C };
static T12: Struct = Struct { a: S };

26
tests/ui/consts/issue-17718-references.stderr
View file

@ -1,27 +1,39 @@
error[E0013]: constants cannot refer to statics
error[E0658]: referencing statics in constants is unstable
--> $DIR/issue-17718-references.rs:9:29
|
LL | const T2: &'static usize = &S;
| ^
|
= help: consider extracting the value of the `static` to a `const`, and referring to that
= note: see issue #119618 <https://github.com/rust-lang/rust/issues/119618> for more information
= help: add `#![feature(const_refs_to_static)]` to the crate attributes to enable
= note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
= note: `static` and `const` variables can refer to other `const` variables. A `const` variable, however, cannot refer to a `static` variable.
= help: to fix this, the value can be extracted to a `const` and then used.
error[E0013]: constants cannot refer to statics
error[E0658]: referencing statics in constants is unstable
--> $DIR/issue-17718-references.rs:14:19
|
LL | const T6: usize = S;
| ^
|
= help: consider extracting the value of the `static` to a `const`, and referring to that
= note: see issue #119618 <https://github.com/rust-lang/rust/issues/119618> for more information
= help: add `#![feature(const_refs_to_static)]` to the crate attributes to enable
= note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
= note: `static` and `const` variables can refer to other `const` variables. A `const` variable, however, cannot refer to a `static` variable.
= help: to fix this, the value can be extracted to a `const` and then used.
error[E0013]: constants cannot refer to statics
error[E0658]: referencing statics in constants is unstable
--> $DIR/issue-17718-references.rs:19:33
|
LL | const T10: Struct = Struct { a: S };
| ^
|
= help: consider extracting the value of the `static` to a `const`, and referring to that
= note: see issue #119618 <https://github.com/rust-lang/rust/issues/119618> for more information
= help: add `#![feature(const_refs_to_static)]` to the crate attributes to enable
= note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
= note: `static` and `const` variables can refer to other `const` variables. A `const` variable, however, cannot refer to a `static` variable.
= help: to fix this, the value can be extracted to a `const` and then used.
error: aborting due to 3 previous errors
For more information about this error, try `rustc --explain E0013`.
For more information about this error, try `rustc --explain E0658`.

2
tests/ui/consts/issue-52060.rs
View file

@ -2,6 +2,6 @@
// The compiler shouldn't ICE in this case
static A: &'static [u32] = &[1];
static B: [u32; 1] = [0; A.len()];
//~^ ERROR [E0013]
//~^ ERROR referencing statics in constants
fn main() {}

10
tests/ui/consts/issue-52060.stderr
View file

@ -1,11 +1,15 @@
error[E0013]: constants cannot refer to statics
error[E0658]: referencing statics in constants is unstable
--> $DIR/issue-52060.rs:4:26
|
LL | static B: [u32; 1] = [0; A.len()];
| ^
|
= help: consider extracting the value of the `static` to a `const`, and referring to that
= note: see issue #119618 <https://github.com/rust-lang/rust/issues/119618> for more information
= help: add `#![feature(const_refs_to_static)]` to the crate attributes to enable
= note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
= note: `static` and `const` variables can refer to other `const` variables. A `const` variable, however, cannot refer to a `static` variable.
= help: to fix this, the value can be extracted to a `const` and then used.
error: aborting due to 1 previous error
For more information about this error, try `rustc --explain E0013`.
For more information about this error, try `rustc --explain E0658`.

4
tests/ui/consts/min_const_fn/min_const_fn.rs
View file

@ -86,8 +86,8 @@ const fn foo11_2<T: Send>(t: T) -> T { t }
// not ok
static BAR: u32 = 42;
const fn foo25() -> u32 { BAR } //~ ERROR cannot refer to statics
const fn foo26() -> &'static u32 { &BAR } //~ ERROR cannot refer to statics
const fn foo25() -> u32 { BAR } //~ ERROR referencing statics in constant functions
const fn foo26() -> &'static u32 { &BAR } //~ ERROR referencing statics in constant functions
const fn foo30(x: *const u32) -> usize { x as usize }
//~^ ERROR pointers cannot be cast to integers
const fn foo30_with_unsafe(x: *const u32) -> usize { unsafe { x as usize } }

20
tests/ui/consts/min_const_fn/min_const_fn.stderr
View file

@ -142,21 +142,29 @@ LL | const fn get_mut_sq(&mut self) -> &mut T { &mut self.0 }
= help: add `#![feature(const_mut_refs)]` to the crate attributes to enable
= note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
error[E0013]: constant functions cannot refer to statics
error[E0658]: referencing statics in constant functions is unstable
--> $DIR/min_const_fn.rs:89:27
|
LL | const fn foo25() -> u32 { BAR }
| ^^^
|
= help: consider extracting the value of the `static` to a `const`, and referring to that
= note: see issue #119618 <https://github.com/rust-lang/rust/issues/119618> for more information
= help: add `#![feature(const_refs_to_static)]` to the crate attributes to enable
= note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
= note: `static` and `const` variables can refer to other `const` variables. A `const` variable, however, cannot refer to a `static` variable.
= help: to fix this, the value can be extracted to a `const` and then used.
error[E0013]: constant functions cannot refer to statics
error[E0658]: referencing statics in constant functions is unstable
--> $DIR/min_const_fn.rs:90:37
|
LL | const fn foo26() -> &'static u32 { &BAR }
| ^^^
|
= help: consider extracting the value of the `static` to a `const`, and referring to that
= note: see issue #119618 <https://github.com/rust-lang/rust/issues/119618> for more information
= help: add `#![feature(const_refs_to_static)]` to the crate attributes to enable
= note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
= note: `static` and `const` variables can refer to other `const` variables. A `const` variable, however, cannot refer to a `static` variable.
= help: to fix this, the value can be extracted to a `const` and then used.
error: pointers cannot be cast to integers during const eval
--> $DIR/min_const_fn.rs:91:42
@ -222,5 +230,5 @@ LL | const fn no_apit(_x: impl std::fmt::Debug) {}
error: aborting due to 24 previous errors
Some errors have detailed explanations: E0013, E0493, E0658.
For more information about an error, try `rustc --explain E0013`.
Some errors have detailed explanations: E0493, E0658.
For more information about an error, try `rustc --explain E0493`.

53
tests/ui/consts/miri_unleashed/const_refers_to_static.32bit.stderr
View file

@ -8,50 +8,28 @@ error[E0080]: evaluation of constant value failed
--> $DIR/const_refers_to_static.rs:14:14
|
LL | unsafe { *(&FOO as *const _ as *const usize) }
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constant accesses static
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constant accesses mutable global memory
error[E0080]: evaluation of constant value failed
--> $DIR/const_refers_to_static.rs:18:32
|
LL | const READ_MUT: u32 = unsafe { MUTABLE };
| ^^^^^^^ constant accesses static
| ^^^^^^^ constant accesses mutable global memory
error[E0080]: it is undefined behavior to use this value
--> $DIR/const_refers_to_static.rs:20:1
--> $DIR/const_refers_to_static.rs:21:1
|
LL | const REF_INTERIOR_MUT: &usize = {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered a reference pointing to a static variable in a constant
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered reference to mutable memory in `const`
|
= note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
= note: the raw bytes of the constant (size: 4, align: 4) {
╾ALLOC0<imm>╼ │ ╾──╼
}
error[E0080]: it is undefined behavior to use this value
--> $DIR/const_refers_to_static.rs:27:1
|
LL | const READ_IMMUT: &usize = {
| ^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered a reference pointing to a static variable in a constant
|
= note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
= note: the raw bytes of the constant (size: 4, align: 4) {
╾ALLOC1<imm>╼ │ ╾──╼
}
error[E0080]: it is undefined behavior to use this value
--> $DIR/const_refers_to_static.rs:34:1
|
LL | const REF_IMMUT: &u8 = &MY_STATIC;
| ^^^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered a reference pointing to a static variable in a constant
|
= note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
= note: the raw bytes of the constant (size: 4, align: 4) {
╾ALLOC2<imm>╼ │ ╾──╼
}
warning: skipping const checks
|
help: skipping check that does not even have a feature gate
help: skipping check for `const_refs_to_static` feature
--> $DIR/const_refers_to_static.rs:9:5
|
LL | FOO.fetch_add(1, Ordering::Relaxed)
@ -61,37 +39,32 @@ help: skipping check that does not even have a feature gate
|
LL | FOO.fetch_add(1, Ordering::Relaxed)
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
help: skipping check that does not even have a feature gate
help: skipping check for `const_refs_to_static` feature
--> $DIR/const_refers_to_static.rs:14:17
|
LL | unsafe { *(&FOO as *const _ as *const usize) }
| ^^^
help: skipping check that does not even have a feature gate
help: skipping check for `const_refs_to_static` feature
--> $DIR/const_refers_to_static.rs:18:32
|
LL | const READ_MUT: u32 = unsafe { MUTABLE };
| ^^^^^^^
help: skipping check that does not even have a feature gate
help: skipping check for `const_refs_to_static` feature
--> $DIR/const_refers_to_static.rs:18:32
|
LL | const READ_MUT: u32 = unsafe { MUTABLE };
| ^^^^^^^
help: skipping check that does not even have a feature gate
--> $DIR/const_refers_to_static.rs:23:18
help: skipping check for `const_refs_to_static` feature
--> $DIR/const_refers_to_static.rs:24:18
|
LL | unsafe { &*(&FOO as *const _ as *const usize) }
| ^^^
help: skipping check that does not even have a feature gate
--> $DIR/const_refers_to_static.rs:30:6
|
LL | &FOO
| ^^^
help: skipping check that does not even have a feature gate
--> $DIR/const_refers_to_static.rs:34:25
help: skipping check for `const_refs_to_static` feature
--> $DIR/const_refers_to_static.rs:29:25
|
LL | const REF_IMMUT: &u8 = &MY_STATIC;
| ^^^^^^^^^
error: aborting due to 6 previous errors; 1 warning emitted
error: aborting due to 4 previous errors; 1 warning emitted
For more information about this error, try `rustc --explain E0080`.

53
tests/ui/consts/miri_unleashed/const_refers_to_static.64bit.stderr
View file

@ -8,50 +8,28 @@ error[E0080]: evaluation of constant value failed
--> $DIR/const_refers_to_static.rs:14:14
|
LL | unsafe { *(&FOO as *const _ as *const usize) }
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constant accesses static
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constant accesses mutable global memory
error[E0080]: evaluation of constant value failed
--> $DIR/const_refers_to_static.rs:18:32
|
LL | const READ_MUT: u32 = unsafe { MUTABLE };
| ^^^^^^^ constant accesses static
| ^^^^^^^ constant accesses mutable global memory
error[E0080]: it is undefined behavior to use this value
--> $DIR/const_refers_to_static.rs:20:1
--> $DIR/const_refers_to_static.rs:21:1
|
LL | const REF_INTERIOR_MUT: &usize = {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered a reference pointing to a static variable in a constant
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered reference to mutable memory in `const`
|
= note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
= note: the raw bytes of the constant (size: 8, align: 8) {
╾ALLOC0<imm>╼ │ ╾──────╼
}
error[E0080]: it is undefined behavior to use this value
--> $DIR/const_refers_to_static.rs:27:1
|
LL | const READ_IMMUT: &usize = {
| ^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered a reference pointing to a static variable in a constant
|
= note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
= note: the raw bytes of the constant (size: 8, align: 8) {
╾ALLOC1<imm>╼ │ ╾──────╼
}
error[E0080]: it is undefined behavior to use this value
--> $DIR/const_refers_to_static.rs:34:1
|
LL | const REF_IMMUT: &u8 = &MY_STATIC;
| ^^^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered a reference pointing to a static variable in a constant
|
= note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
= note: the raw bytes of the constant (size: 8, align: 8) {
╾ALLOC2<imm>╼ │ ╾──────╼
}
warning: skipping const checks
|
help: skipping check that does not even have a feature gate
help: skipping check for `const_refs_to_static` feature
--> $DIR/const_refers_to_static.rs:9:5
|
LL | FOO.fetch_add(1, Ordering::Relaxed)
@ -61,37 +39,32 @@ help: skipping check that does not even have a feature gate
|
LL | FOO.fetch_add(1, Ordering::Relaxed)
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
help: skipping check that does not even have a feature gate
help: skipping check for `const_refs_to_static` feature
--> $DIR/const_refers_to_static.rs:14:17
|
LL | unsafe { *(&FOO as *const _ as *const usize) }
| ^^^
help: skipping check that does not even have a feature gate
help: skipping check for `const_refs_to_static` feature
--> $DIR/const_refers_to_static.rs:18:32
|
LL | const READ_MUT: u32 = unsafe { MUTABLE };
| ^^^^^^^
help: skipping check that does not even have a feature gate
help: skipping check for `const_refs_to_static` feature
--> $DIR/const_refers_to_static.rs:18:32
|
LL | const READ_MUT: u32 = unsafe { MUTABLE };
| ^^^^^^^
help: skipping check that does not even have a feature gate
--> $DIR/const_refers_to_static.rs:23:18
help: skipping check for `const_refs_to_static` feature
--> $DIR/const_refers_to_static.rs:24:18
|
LL | unsafe { &*(&FOO as *const _ as *const usize) }
| ^^^
help: skipping check that does not even have a feature gate
--> $DIR/const_refers_to_static.rs:30:6
|
LL | &FOO
| ^^^
help: skipping check that does not even have a feature gate
--> $DIR/const_refers_to_static.rs:34:25
help: skipping check for `const_refs_to_static` feature
--> $DIR/const_refers_to_static.rs:29:25
|
LL | const REF_IMMUT: &u8 = &MY_STATIC;
| ^^^^^^^^^
error: aborting due to 6 previous errors; 1 warning emitted
error: aborting due to 4 previous errors; 1 warning emitted
For more information about this error, try `rustc --explain E0080`.

16
tests/ui/consts/miri_unleashed/const_refers_to_static.rs
View file

@ -17,22 +17,16 @@ const READ_INTERIOR_MUT: usize = {
static mut MUTABLE: u32 = 0;
const READ_MUT: u32 = unsafe { MUTABLE }; //~ERROR evaluation of constant value failed
const REF_INTERIOR_MUT: &usize = { //~ ERROR undefined behavior to use this value
//~| encountered a reference pointing to a static variable
// Evaluating this does not read anything mutable, but validation does, so this should error.
const REF_INTERIOR_MUT: &usize = { //~ ERROR undefined behavior
//~| encountered reference to mutable memory
static FOO: AtomicUsize = AtomicUsize::new(0);
unsafe { &*(&FOO as *const _ as *const usize) }
};
// ok some day perhaps
const READ_IMMUT: &usize = { //~ ERROR it is undefined behavior to use this value
//~| encountered a reference pointing to a static variable
static FOO: usize = 0;
&FOO
};
// Not actually reading from anything mutable, so these are fine.
static MY_STATIC: u8 = 4;
const REF_IMMUT: &u8 = &MY_STATIC;
//~^ ERROR it is undefined behavior to use this value
//~| encountered a reference pointing to a static variable
const READ_IMMUT: u8 = *REF_IMMUT;
fn main() {}

77
tests/ui/consts/miri_unleashed/const_refers_to_static_cross_crate.32bit.stderr
View file

@ -1,5 +1,5 @@
warning: shared reference of mutable static is discouraged
--> $DIR/const_refers_to_static_cross_crate.rs:13:14
--> $DIR/const_refers_to_static_cross_crate.rs:12:14
|
LL | unsafe { &static_cross_crate::ZERO }
| ^^^^^^^^^^^^^^^^^^^^^^^^^ shared reference of mutable static
@ -17,7 +17,7 @@ error[E0080]: it is undefined behavior to use this value
--> $DIR/const_refers_to_static_cross_crate.rs:10:1
|
LL | const SLICE_MUT: &[u8; 1] = {
| ^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered a reference pointing to a static variable in a constant
| ^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered reference to mutable memory in `const`
|
= note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
= note: the raw bytes of the constant (size: 4, align: 4) {
@ -25,16 +25,16 @@ LL | const SLICE_MUT: &[u8; 1] = {
}
error: could not evaluate constant pattern
--> $DIR/const_refers_to_static_cross_crate.rs:42:9
--> $DIR/const_refers_to_static_cross_crate.rs:39:9
|
LL | SLICE_MUT => true,
| ^^^^^^^^^
error[E0080]: it is undefined behavior to use this value
--> $DIR/const_refers_to_static_cross_crate.rs:17:1
--> $DIR/const_refers_to_static_cross_crate.rs:16:1
|
LL | const U8_MUT: &u8 = {
| ^^^^^^^^^^^^^^^^^ constructing invalid value: encountered a reference pointing to a static variable in a constant
| ^^^^^^^^^^^^^^^^^ constructing invalid value: encountered reference to mutable memory in `const`
|
= note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
= note: the raw bytes of the constant (size: 4, align: 4) {
@ -42,89 +42,94 @@ LL | const U8_MUT: &u8 = {
}
error: could not evaluate constant pattern
--> $DIR/const_refers_to_static_cross_crate.rs:50:9
--> $DIR/const_refers_to_static_cross_crate.rs:47:9
|
LL | U8_MUT => true,
| ^^^^^^
error[E0080]: evaluation of constant value failed
--> $DIR/const_refers_to_static_cross_crate.rs:25:15
error[E0080]: it is undefined behavior to use this value
--> $DIR/const_refers_to_static_cross_crate.rs:22:1
|
LL | unsafe { &(*static_cross_crate::ZERO_REF)[0] }
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constant accesses static
LL | const U8_MUT2: &u8 = {
| ^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered reference to mutable memory in `const`
|
= note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
= note: the raw bytes of the constant (size: 4, align: 4) {
╾ALLOC0<imm>╼ │ ╾──╼
}
error: could not evaluate constant pattern
--> $DIR/const_refers_to_static_cross_crate.rs:60:9
--> $DIR/const_refers_to_static_cross_crate.rs:57:9
|
LL | U8_MUT2 => true,
| ^^^^^^^
error[E0080]: evaluation of constant value failed
--> $DIR/const_refers_to_static_cross_crate.rs:31:15
--> $DIR/const_refers_to_static_cross_crate.rs:28:15
|
LL | match static_cross_crate::OPT_ZERO {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constant accesses static
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constant accesses mutable global memory
error: could not evaluate constant pattern
--> $DIR/const_refers_to_static_cross_crate.rs:67:9
--> $DIR/const_refers_to_static_cross_crate.rs:64:9
|
LL | U8_MUT3 => true,
| ^^^^^^^
warning: skipping const checks
|
help: skipping check that does not even have a feature gate
--> $DIR/const_refers_to_static_cross_crate.rs:13:15
help: skipping check for `const_refs_to_static` feature
--> $DIR/const_refers_to_static_cross_crate.rs:12:15
|
LL | unsafe { &static_cross_crate::ZERO }
| ^^^^^^^^^^^^^^^^^^^^^^^^
help: skipping check that does not even have a feature gate
--> $DIR/const_refers_to_static_cross_crate.rs:13:15
help: skipping check for `const_refs_to_static` feature
--> $DIR/const_refers_to_static_cross_crate.rs:12:15
|
LL | unsafe { &static_cross_crate::ZERO }
| ^^^^^^^^^^^^^^^^^^^^^^^^
help: skipping check that does not even have a feature gate
--> $DIR/const_refers_to_static_cross_crate.rs:20:15
help: skipping check for `const_refs_to_static` feature
--> $DIR/const_refers_to_static_cross_crate.rs:18:15
|
LL | unsafe { &static_cross_crate::ZERO[0] }
| ^^^^^^^^^^^^^^^^^^^^^^^^
help: skipping check that does not even have a feature gate
--> $DIR/const_refers_to_static_cross_crate.rs:20:15
help: skipping check for `const_refs_to_static` feature
--> $DIR/const_refers_to_static_cross_crate.rs:18:15
|
LL | unsafe { &static_cross_crate::ZERO[0] }
| ^^^^^^^^^^^^^^^^^^^^^^^^
help: skipping check that does not even have a feature gate
--> $DIR/const_refers_to_static_cross_crate.rs:20:15
help: skipping check for `const_refs_to_static` feature
--> $DIR/const_refers_to_static_cross_crate.rs:18:15
|
LL | unsafe { &static_cross_crate::ZERO[0] }
| ^^^^^^^^^^^^^^^^^^^^^^^^
help: skipping check that does not even have a feature gate
--> $DIR/const_refers_to_static_cross_crate.rs:25:17
help: skipping check for `const_refs_to_static` feature
--> $DIR/const_refers_to_static_cross_crate.rs:24:17
|
LL | unsafe { &(*static_cross_crate::ZERO_REF)[0] }
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
help: skipping check that does not even have a feature gate
--> $DIR/const_refers_to_static_cross_crate.rs:31:15
help: skipping check for `const_refs_to_static` feature
--> $DIR/const_refers_to_static_cross_crate.rs:28:15
|
LL | match static_cross_crate::OPT_ZERO {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
help: skipping check that does not even have a feature gate
--> $DIR/const_refers_to_static_cross_crate.rs:31:15
help: skipping check for `const_refs_to_static` feature
--> $DIR/const_refers_to_static_cross_crate.rs:28:15
|
LL | match static_cross_crate::OPT_ZERO {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
help: skipping check that does not even have a feature gate
--> $DIR/const_refers_to_static_cross_crate.rs:31:15
help: skipping check for `const_refs_to_static` feature
--> $DIR/const_refers_to_static_cross_crate.rs:28:15
|
LL | match static_cross_crate::OPT_ZERO {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
help: skipping check that does not even have a feature gate
--> $DIR/const_refers_to_static_cross_crate.rs:31:15
help: skipping check for `const_refs_to_static` feature
--> $DIR/const_refers_to_static_cross_crate.rs:28:15
|
LL | match static_cross_crate::OPT_ZERO {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
help: skipping check that does not even have a feature gate
--> $DIR/const_refers_to_static_cross_crate.rs:31:15
help: skipping check for `const_refs_to_static` feature
--> $DIR/const_refers_to_static_cross_crate.rs:28:15
|
LL | match static_cross_crate::OPT_ZERO {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^

77
tests/ui/consts/miri_unleashed/const_refers_to_static_cross_crate.64bit.stderr
View file

@ -1,5 +1,5 @@
warning: shared reference of mutable static is discouraged
--> $DIR/const_refers_to_static_cross_crate.rs:13:14
--> $DIR/const_refers_to_static_cross_crate.rs:12:14
|
LL | unsafe { &static_cross_crate::ZERO }
| ^^^^^^^^^^^^^^^^^^^^^^^^^ shared reference of mutable static
@ -17,7 +17,7 @@ error[E0080]: it is undefined behavior to use this value
--> $DIR/const_refers_to_static_cross_crate.rs:10:1
|
LL | const SLICE_MUT: &[u8; 1] = {
| ^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered a reference pointing to a static variable in a constant
| ^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered reference to mutable memory in `const`
|
= note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
= note: the raw bytes of the constant (size: 8, align: 8) {
@ -25,16 +25,16 @@ LL | const SLICE_MUT: &[u8; 1] = {
}
error: could not evaluate constant pattern
--> $DIR/const_refers_to_static_cross_crate.rs:42:9
--> $DIR/const_refers_to_static_cross_crate.rs:39:9
|
LL | SLICE_MUT => true,
| ^^^^^^^^^
error[E0080]: it is undefined behavior to use this value
--> $DIR/const_refers_to_static_cross_crate.rs:17:1
--> $DIR/const_refers_to_static_cross_crate.rs:16:1
|
LL | const U8_MUT: &u8 = {
| ^^^^^^^^^^^^^^^^^ constructing invalid value: encountered a reference pointing to a static variable in a constant
| ^^^^^^^^^^^^^^^^^ constructing invalid value: encountered reference to mutable memory in `const`
|
= note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
= note: the raw bytes of the constant (size: 8, align: 8) {
@ -42,89 +42,94 @@ LL | const U8_MUT: &u8 = {
}
error: could not evaluate constant pattern
--> $DIR/const_refers_to_static_cross_crate.rs:50:9
--> $DIR/const_refers_to_static_cross_crate.rs:47:9
|
LL | U8_MUT => true,
| ^^^^^^
error[E0080]: evaluation of constant value failed
--> $DIR/const_refers_to_static_cross_crate.rs:25:15
error[E0080]: it is undefined behavior to use this value
--> $DIR/const_refers_to_static_cross_crate.rs:22:1
|
LL | unsafe { &(*static_cross_crate::ZERO_REF)[0] }
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constant accesses static
LL | const U8_MUT2: &u8 = {
| ^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered reference to mutable memory in `const`
|
= note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
= note: the raw bytes of the constant (size: 8, align: 8) {
╾ALLOC0<imm>╼ │ ╾──────╼
}
error: could not evaluate constant pattern
--> $DIR/const_refers_to_static_cross_crate.rs:60:9
--> $DIR/const_refers_to_static_cross_crate.rs:57:9
|
LL | U8_MUT2 => true,
| ^^^^^^^
error[E0080]: evaluation of constant value failed
--> $DIR/const_refers_to_static_cross_crate.rs:31:15
--> $DIR/const_refers_to_static_cross_crate.rs:28:15
|
LL | match static_cross_crate::OPT_ZERO {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constant accesses static
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constant accesses mutable global memory
error: could not evaluate constant pattern
--> $DIR/const_refers_to_static_cross_crate.rs:67:9
--> $DIR/const_refers_to_static_cross_crate.rs:64:9
|
LL | U8_MUT3 => true,
| ^^^^^^^
warning: skipping const checks
|
help: skipping check that does not even have a feature gate
--> $DIR/const_refers_to_static_cross_crate.rs:13:15
help: skipping check for `const_refs_to_static` feature
--> $DIR/const_refers_to_static_cross_crate.rs:12:15
|
LL | unsafe { &static_cross_crate::ZERO }
| ^^^^^^^^^^^^^^^^^^^^^^^^
help: skipping check that does not even have a feature gate
--> $DIR/const_refers_to_static_cross_crate.rs:13:15
help: skipping check for `const_refs_to_static` feature
--> $DIR/const_refers_to_static_cross_crate.rs:12:15
|
LL | unsafe { &static_cross_crate::ZERO }
| ^^^^^^^^^^^^^^^^^^^^^^^^
help: skipping check that does not even have a feature gate
--> $DIR/const_refers_to_static_cross_crate.rs:20:15
help: skipping check for `const_refs_to_static` feature
--> $DIR/const_refers_to_static_cross_crate.rs:18:15
|
LL | unsafe { &static_cross_crate::ZERO[0] }
| ^^^^^^^^^^^^^^^^^^^^^^^^
help: skipping check that does not even have a feature gate
--> $DIR/const_refers_to_static_cross_crate.rs:20:15
help: skipping check for `const_refs_to_static` feature
--> $DIR/const_refers_to_static_cross_crate.rs:18:15
|
LL | unsafe { &static_cross_crate::ZERO[0] }
| ^^^^^^^^^^^^^^^^^^^^^^^^
help: skipping check that does not even have a feature gate
--> $DIR/const_refers_to_static_cross_crate.rs:20:15
help: skipping check for `const_refs_to_static` feature
--> $DIR/const_refers_to_static_cross_crate.rs:18:15
|
LL | unsafe { &static_cross_crate::ZERO[0] }
| ^^^^^^^^^^^^^^^^^^^^^^^^
help: skipping check that does not even have a feature gate
--> $DIR/const_refers_to_static_cross_crate.rs:25:17
help: skipping check for `const_refs_to_static` feature
--> $DIR/const_refers_to_static_cross_crate.rs:24:17
|
LL | unsafe { &(*static_cross_crate::ZERO_REF)[0] }
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
help: skipping check that does not even have a feature gate
--> $DIR/const_refers_to_static_cross_crate.rs:31:15
help: skipping check for `const_refs_to_static` feature
--> $DIR/const_refers_to_static_cross_crate.rs:28:15
|
LL | match static_cross_crate::OPT_ZERO {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
help: skipping check that does not even have a feature gate
--> $DIR/const_refers_to_static_cross_crate.rs:31:15
help: skipping check for `const_refs_to_static` feature
--> $DIR/const_refers_to_static_cross_crate.rs:28:15
|
LL | match static_cross_crate::OPT_ZERO {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
help: skipping check that does not even have a feature gate
--> $DIR/const_refers_to_static_cross_crate.rs:31:15
help: skipping check for `const_refs_to_static` feature
--> $DIR/const_refers_to_static_cross_crate.rs:28:15
|
LL | match static_cross_crate::OPT_ZERO {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
help: skipping check that does not even have a feature gate
--> $DIR/const_refers_to_static_cross_crate.rs:31:15
help: skipping check for `const_refs_to_static` feature
--> $DIR/const_refers_to_static_cross_crate.rs:28:15
|
LL | match static_cross_crate::OPT_ZERO {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
help: skipping check that does not even have a feature gate
--> $DIR/const_refers_to_static_cross_crate.rs:31:15
help: skipping check for `const_refs_to_static` feature
--> $DIR/const_refers_to_static_cross_crate.rs:28:15
|
LL | match static_cross_crate::OPT_ZERO {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^

17
tests/ui/consts/miri_unleashed/const_refers_to_static_cross_crate.rs
View file

@ -7,30 +7,27 @@ extern crate static_cross_crate;
// Sneaky: reference to a mutable static.
// Allowing this would be a disaster for pattern matching, we could violate exhaustiveness checking!
const SLICE_MUT: &[u8; 1] = {
//~^ ERROR undefined behavior to use this value
//~| encountered a reference pointing to a static variable
const SLICE_MUT: &[u8; 1] = { //~ ERROR undefined behavior
//~| encountered reference to mutable memory
unsafe { &static_cross_crate::ZERO }
//~^ WARN shared reference of mutable static is discouraged [static_mut_ref]
};
const U8_MUT: &u8 = {
//~^ ERROR undefined behavior to use this value
//~| encountered a reference pointing to a static variable
const U8_MUT: &u8 = { //~ ERROR undefined behavior
//~| encountered reference to mutable memory
unsafe { &static_cross_crate::ZERO[0] }
};
// Also test indirection that reads from other static.
const U8_MUT2: &u8 = {
const U8_MUT2: &u8 = { //~ ERROR undefined behavior
//~| encountered reference to mutable memory
unsafe { &(*static_cross_crate::ZERO_REF)[0] }
//~^ ERROR evaluation of constant value failed
//~| constant accesses static
};
const U8_MUT3: &u8 = {
unsafe {
match static_cross_crate::OPT_ZERO {
//~^ ERROR evaluation of constant value failed
//~| constant accesses static
//~| constant accesses mutable global memory
Some(ref u) => u,
None => panic!(),
}

22
tests/ui/consts/miri_unleashed/mutable_references_err.32bit.stderr
View file

@ -42,18 +42,24 @@ error[E0080]: it is undefined behavior to use this value
--> $DIR/mutable_references_err.rs:47:1
|
LL | const POINTS_TO_MUTABLE1: &i32 = unsafe { &MUTABLE };
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered a reference pointing to a static variable in a constant
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered reference to mutable memory in `const`
|
= note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
= note: the raw bytes of the constant (size: 4, align: 4) {
╾ALLOC2<imm>╼ │ ╾──╼
}
note: erroneous constant encountered
--> $DIR/mutable_references_err.rs:49:34
|
LL | const READS_FROM_MUTABLE: i32 = *POINTS_TO_MUTABLE1;
| ^^^^^^^^^^^^^^^^^^
error[E0080]: evaluation of constant value failed
--> $DIR/mutable_references_err.rs:51:43
|
LL | const POINTS_TO_MUTABLE2: &i32 = unsafe { &*MUTABLE_REF };
| ^^^^^^^^^^^^^ constant accesses static
| ^^^^^^^^^^^^^ constant accesses mutable global memory
error: encountered mutable pointer in final value of constant
--> $DIR/mutable_references_err.rs:55:1
@ -103,12 +109,12 @@ help: skipping check that does not even have a feature gate
|
LL | const SNEAKY: &dyn Sync = &Synced { x: UnsafeCell::new(42) };
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
help: skipping check that does not even have a feature gate
help: skipping check for `const_refs_to_static` feature
--> $DIR/mutable_references_err.rs:32:40
|
LL | const SUBTLE: &mut i32 = unsafe { &mut FOO };
| ^^^
help: skipping check that does not even have a feature gate
help: skipping check for `const_refs_to_static` feature
--> $DIR/mutable_references_err.rs:32:40
|
LL | const SUBTLE: &mut i32 = unsafe { &mut FOO };
@ -133,22 +139,22 @@ help: skipping check for `const_mut_refs` feature
|
LL | static mut MUT_TO_READONLY: &mut i32 = unsafe { &mut *(&READONLY as *const _ as *mut _) };
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
help: skipping check that does not even have a feature gate
help: skipping check for `const_refs_to_static` feature
--> $DIR/mutable_references_err.rs:47:44
|
LL | const POINTS_TO_MUTABLE1: &i32 = unsafe { &MUTABLE };
| ^^^^^^^
help: skipping check that does not even have a feature gate
help: skipping check for `const_refs_to_static` feature
--> $DIR/mutable_references_err.rs:47:44
|
LL | const POINTS_TO_MUTABLE1: &i32 = unsafe { &MUTABLE };
| ^^^^^^^
help: skipping check that does not even have a feature gate
help: skipping check for `const_refs_to_static` feature
--> $DIR/mutable_references_err.rs:51:45
|
LL | const POINTS_TO_MUTABLE2: &i32 = unsafe { &*MUTABLE_REF };
| ^^^^^^^^^^^
help: skipping check that does not even have a feature gate
help: skipping check for `const_refs_to_static` feature
--> $DIR/mutable_references_err.rs:51:45
|
LL | const POINTS_TO_MUTABLE2: &i32 = unsafe { &*MUTABLE_REF };

22
tests/ui/consts/miri_unleashed/mutable_references_err.64bit.stderr
View file

@ -42,18 +42,24 @@ error[E0080]: it is undefined behavior to use this value
--> $DIR/mutable_references_err.rs:47:1
|
LL | const POINTS_TO_MUTABLE1: &i32 = unsafe { &MUTABLE };
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered a reference pointing to a static variable in a constant
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered reference to mutable memory in `const`
|
= note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
= note: the raw bytes of the constant (size: 8, align: 8) {
╾ALLOC2<imm>╼ │ ╾──────╼
}
note: erroneous constant encountered
--> $DIR/mutable_references_err.rs:49:34
|
LL | const READS_FROM_MUTABLE: i32 = *POINTS_TO_MUTABLE1;
| ^^^^^^^^^^^^^^^^^^
error[E0080]: evaluation of constant value failed
--> $DIR/mutable_references_err.rs:51:43
|
LL | const POINTS_TO_MUTABLE2: &i32 = unsafe { &*MUTABLE_REF };
| ^^^^^^^^^^^^^ constant accesses static
| ^^^^^^^^^^^^^ constant accesses mutable global memory
error: encountered mutable pointer in final value of constant
--> $DIR/mutable_references_err.rs:55:1
@ -103,12 +109,12 @@ help: skipping check that does not even have a feature gate
|
LL | const SNEAKY: &dyn Sync = &Synced { x: UnsafeCell::new(42) };
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
help: skipping check that does not even have a feature gate
help: skipping check for `const_refs_to_static` feature
--> $DIR/mutable_references_err.rs:32:40
|
LL | const SUBTLE: &mut i32 = unsafe { &mut FOO };
| ^^^
help: skipping check that does not even have a feature gate
help: skipping check for `const_refs_to_static` feature
--> $DIR/mutable_references_err.rs:32:40
|
LL | const SUBTLE: &mut i32 = unsafe { &mut FOO };
@ -133,22 +139,22 @@ help: skipping check for `const_mut_refs` feature
|
LL | static mut MUT_TO_READONLY: &mut i32 = unsafe { &mut *(&READONLY as *const _ as *mut _) };
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
help: skipping check that does not even have a feature gate
help: skipping check for `const_refs_to_static` feature
--> $DIR/mutable_references_err.rs:47:44
|
LL | const POINTS_TO_MUTABLE1: &i32 = unsafe { &MUTABLE };
| ^^^^^^^
help: skipping check that does not even have a feature gate
help: skipping check for `const_refs_to_static` feature
--> $DIR/mutable_references_err.rs:47:44
|
LL | const POINTS_TO_MUTABLE1: &i32 = unsafe { &MUTABLE };
| ^^^^^^^
help: skipping check that does not even have a feature gate
help: skipping check for `const_refs_to_static` feature
--> $DIR/mutable_references_err.rs:51:45
|
LL | const POINTS_TO_MUTABLE2: &i32 = unsafe { &*MUTABLE_REF };
| ^^^^^^^^^^^
help: skipping check that does not even have a feature gate
help: skipping check for `const_refs_to_static` feature
--> $DIR/mutable_references_err.rs:51:45
|
LL | const POINTS_TO_MUTABLE2: &i32 = unsafe { &*MUTABLE_REF };

10
tests/ui/consts/miri_unleashed/mutable_references_err.rs
View file

@ -42,15 +42,15 @@ static mut MUT_TO_READONLY: &mut i32 = unsafe { &mut *(&READONLY as *const _ as
//~| pointing to read-only memory
// Check for consts pointing to mutable memory.
// Currently it's not even possible to create such a const.
// These are fine as long as they are not being read.
static mut MUTABLE: i32 = 42;
const POINTS_TO_MUTABLE1: &i32 = unsafe { &MUTABLE };
//~^ ERROR: undefined behavior to use this value
//~| pointing to a static
const POINTS_TO_MUTABLE1: &i32 = unsafe { &MUTABLE }; //~ERROR: undefined behavior
//~| encountered reference to mutable memory
const READS_FROM_MUTABLE: i32 = *POINTS_TO_MUTABLE1;
static mut MUTABLE_REF: &mut i32 = &mut 42;
const POINTS_TO_MUTABLE2: &i32 = unsafe { &*MUTABLE_REF };
//~^ ERROR: evaluation of constant value failed
//~| accesses static
//~| accesses mutable global memory
const POINTS_TO_MUTABLE_INNER: *const i32 = &mut 42 as *mut _ as *const _;
//~^ ERROR: mutable pointer in final value

4
tests/ui/error-codes/E0013.rs
View file

@ -1,4 +0,0 @@
static X: i32 = 42;
const Y: i32 = X; //~ ERROR constants cannot refer to statics [E0013]
fn main() {}

11
tests/ui/error-codes/E0013.stderr
View file

@ -1,11 +0,0 @@
error[E0013]: constants cannot refer to statics
--> $DIR/E0013.rs:2:16
|
LL | const Y: i32 = X;
| ^
|
= help: consider extracting the value of the `static` to a `const`, and referring to that
error: aborting due to 1 previous error
For more information about this error, try `rustc --explain E0013`.

12
tests/ui/feature-gates/feature-gate-const-refs-to-static.rs Normal file
View file

@ -0,0 +1,12 @@
static S: i32 = 0;
static mut S_MUT: i32 = 0;
const C1: &i32 = &S; //~ERROR: referencing statics in constants is unstable
const C1_READ: () = {
assert!(*C1 == 0);
};
const C2: *const i32 = unsafe { std::ptr::addr_of!(S_MUT) }; //~ERROR: referencing statics in constants is unstable
//~^ERROR: referencing statics in constants is unstable
fn main() {
}

40
tests/ui/feature-gates/feature-gate-const-refs-to-static.stderr Normal file
View file

@ -0,0 +1,40 @@
error[E0658]: referencing statics in constants is unstable
--> $DIR/feature-gate-const-refs-to-static.rs:4:19
|
LL | const C1: &i32 = &S;
| ^
|
= note: see issue #119618 <https://github.com/rust-lang/rust/issues/119618> for more information
= help: add `#![feature(const_refs_to_static)]` to the crate attributes to enable
= note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
= note: `static` and `const` variables can refer to other `const` variables. A `const` variable, however, cannot refer to a `static` variable.
= help: to fix this, the value can be extracted to a `const` and then used.
error[E0658]: referencing statics in constants is unstable
--> $DIR/feature-gate-const-refs-to-static.rs:8:52
|
LL | const C2: *const i32 = unsafe { std::ptr::addr_of!(S_MUT) };
| ^^^^^
|
= note: see issue #119618 <https://github.com/rust-lang/rust/issues/119618> for more information
= help: add `#![feature(const_refs_to_static)]` to the crate attributes to enable
= note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
= note: `static` and `const` variables can refer to other `const` variables. A `const` variable, however, cannot refer to a `static` variable.
= help: to fix this, the value can be extracted to a `const` and then used.
error[E0658]: referencing statics in constants is unstable
--> $DIR/feature-gate-const-refs-to-static.rs:8:52
|
LL | const C2: *const i32 = unsafe { std::ptr::addr_of!(S_MUT) };
| ^^^^^
|
= note: see issue #119618 <https://github.com/rust-lang/rust/issues/119618> for more information
= help: add `#![feature(const_refs_to_static)]` to the crate attributes to enable
= note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
= note: `static` and `const` variables can refer to other `const` variables. A `const` variable, however, cannot refer to a `static` variable.
= help: to fix this, the value can be extracted to a `const` and then used.
= note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
error: aborting due to 3 previous errors
For more information about this error, try `rustc --explain E0658`.

2
tests/ui/static/issue-18118-2.rs
View file

@ -1,6 +1,6 @@
pub fn main() {
const z: &'static isize = {
static p: isize = 3;
&p //~ ERROR constants cannot refer to statics
&p //~ ERROR referencing statics
};
}

10
tests/ui/static/issue-18118-2.stderr
View file

@ -1,11 +1,15 @@
error[E0013]: constants cannot refer to statics
error[E0658]: referencing statics in constants is unstable
--> $DIR/issue-18118-2.rs:4:10
|
LL | &p
| ^
|
= help: consider extracting the value of the `static` to a `const`, and referring to that
= note: see issue #119618 <https://github.com/rust-lang/rust/issues/119618> for more information
= help: add `#![feature(const_refs_to_static)]` to the crate attributes to enable
= note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
= note: `static` and `const` variables can refer to other `const` variables. A `const` variable, however, cannot refer to a `static` variable.
= help: to fix this, the value can be extracted to a `const` and then used.
error: aborting due to 1 previous error
For more information about this error, try `rustc --explain E0013`.
For more information about this error, try `rustc --explain E0658`.

2
tests/ui/thread-local/thread-local-static.rs
View file

@ -12,7 +12,7 @@ const fn g(x: &mut [u32; 8]) {
//~^^ ERROR thread-local statics cannot be accessed
//~| ERROR mutable references are not allowed
//~| ERROR use of mutable static is unsafe
//~| constant functions cannot refer to statics
//~| referencing statics
}
fn main() {}

12
tests/ui/thread-local/thread-local-static.stderr
View file

@ -37,13 +37,17 @@ error[E0625]: thread-local statics cannot be accessed at compile-time
LL | std::mem::swap(x, &mut STATIC_VAR_2)
| ^^^^^^^^^^^^
error[E0013]: constant functions cannot refer to statics
error[E0658]: referencing statics in constant functions is unstable
--> $DIR/thread-local-static.rs:10:28
|
LL | std::mem::swap(x, &mut STATIC_VAR_2)
| ^^^^^^^^^^^^
|
= help: consider extracting the value of the `static` to a `const`, and referring to that
= note: see issue #119618 <https://github.com/rust-lang/rust/issues/119618> for more information
= help: add `#![feature(const_refs_to_static)]` to the crate attributes to enable
= note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
= note: `static` and `const` variables can refer to other `const` variables. A `const` variable, however, cannot refer to a `static` variable.
= help: to fix this, the value can be extracted to a `const` and then used.
error[E0658]: mutable references are not allowed in constant functions
--> $DIR/thread-local-static.rs:10:23
@ -57,5 +61,5 @@ LL | std::mem::swap(x, &mut STATIC_VAR_2)
error: aborting due to 5 previous errors; 1 warning emitted
Some errors have detailed explanations: E0013, E0133, E0625, E0658.
For more information about an error, try `rustc --explain E0013`.
Some errors have detailed explanations: E0133, E0625, E0658.
For more information about an error, try `rustc --explain E0133`.