diff --git a/compiler/rustc_const_eval/messages.ftl b/compiler/rustc_const_eval/messages.ftl index b767ca9a3c251..0463788401189 100644 --- a/compiler/rustc_const_eval/messages.ftl +++ b/compiler/rustc_const_eval/messages.ftl @@ -56,6 +56,17 @@ const_eval_const_context = {$kind -> *[other] {""} } +const_eval_const_heap_ptr_in_final = encountered `const_allocate` pointer in final value that was not made global + .note = use `const_make_global` to make allocated pointers immutable before returning + +const_eval_const_make_global_ptr_already_made_global = attempting to call `const_make_global` twice on the same allocation {$alloc} + +const_eval_const_make_global_ptr_is_non_heap = pointer passed to `const_make_global` does not point to a heap allocation: {$ptr} + +const_eval_const_make_global_with_dangling_ptr = pointer passed to `const_make_global` is dangling: {$ptr} + +const_eval_const_make_global_with_offset = making {$ptr} global which does not point to the beginning of an object + const_eval_copy_nonoverlapping_overlapping = `copy_nonoverlapping` called on overlapping ranges diff --git a/compiler/rustc_const_eval/src/const_eval/dummy_machine.rs b/compiler/rustc_const_eval/src/const_eval/dummy_machine.rs index b6e2682af367b..438aed41b8be3 100644 --- a/compiler/rustc_const_eval/src/const_eval/dummy_machine.rs +++ b/compiler/rustc_const_eval/src/const_eval/dummy_machine.rs @@ -49,7 +49,6 @@ impl HasStaticRootDefId for DummyMachine { impl<'tcx> interpret::Machine<'tcx> for DummyMachine { interpret::compile_time_machine!(<'tcx>); - type MemoryKind = !; const PANIC_ON_ALLOC_FAIL: bool = true; // We want to just eval random consts in the program, so `eval_mir_const` can fail. diff --git a/compiler/rustc_const_eval/src/const_eval/error.rs b/compiler/rustc_const_eval/src/const_eval/error.rs index 08fc03d9c4647..3e880d0200133 100644 --- a/compiler/rustc_const_eval/src/const_eval/error.rs +++ b/compiler/rustc_const_eval/src/const_eval/error.rs @@ -2,7 +2,7 @@ use std::mem; use rustc_errors::{Diag, DiagArgName, DiagArgValue, DiagMessage, IntoDiagArg}; use rustc_middle::mir::AssertKind; -use rustc_middle::mir::interpret::{Provenance, ReportedErrorInfo}; +use rustc_middle::mir::interpret::{AllocId, Provenance, ReportedErrorInfo}; use rustc_middle::query::TyCtxtAt; use rustc_middle::ty::layout::LayoutError; use rustc_middle::ty::{ConstInt, TyCtxt}; @@ -11,8 +11,8 @@ use rustc_span::{Span, Symbol}; use super::CompileTimeMachine; use crate::errors::{self, FrameNote, ReportErrorExt}; use crate::interpret::{ - ErrorHandled, Frame, InterpErrorInfo, InterpErrorKind, MachineStopType, err_inval, - err_machine_stop, + CtfeProvenance, ErrorHandled, Frame, InterpErrorInfo, InterpErrorKind, MachineStopType, + Pointer, err_inval, err_machine_stop, }; /// The CTFE machine has some custom error kinds. @@ -22,8 +22,22 @@ pub enum ConstEvalErrKind { ModifiedGlobal, RecursiveStatic, AssertFailure(AssertKind), - Panic { msg: Symbol, line: u32, col: u32, file: Symbol }, + Panic { + msg: Symbol, + line: u32, + col: u32, + file: Symbol, + }, WriteThroughImmutablePointer, + /// Called `const_make_global` twice. + ConstMakeGlobalPtrAlreadyMadeGlobal(AllocId), + /// Called `const_make_global` on a non-heap pointer. + ConstMakeGlobalPtrIsNonHeap(Pointer>), + /// Called `const_make_global` on a dangling pointer. + ConstMakeGlobalWithDanglingPtr(Pointer>), + /// Called `const_make_global` on a pointer that does not start at the + /// beginning of an object. + ConstMakeGlobalWithOffset(Pointer>), } impl MachineStopType for ConstEvalErrKind { @@ -38,6 +52,12 @@ impl MachineStopType for ConstEvalErrKind { RecursiveStatic => const_eval_recursive_static, AssertFailure(x) => x.diagnostic_message(), WriteThroughImmutablePointer => const_eval_write_through_immutable_pointer, + ConstMakeGlobalPtrAlreadyMadeGlobal { .. } => { + const_eval_const_make_global_ptr_already_made_global + } + ConstMakeGlobalPtrIsNonHeap(_) => const_eval_const_make_global_ptr_is_non_heap, + ConstMakeGlobalWithDanglingPtr(_) => const_eval_const_make_global_with_dangling_ptr, + ConstMakeGlobalWithOffset(_) => const_eval_const_make_global_with_offset, } } fn add_args(self: Box, adder: &mut dyn FnMut(DiagArgName, DiagArgValue)) { @@ -51,6 +71,14 @@ impl MachineStopType for ConstEvalErrKind { Panic { msg, .. } => { adder("msg".into(), msg.into_diag_arg(&mut None)); } + ConstMakeGlobalPtrIsNonHeap(ptr) + | ConstMakeGlobalWithOffset(ptr) + | ConstMakeGlobalWithDanglingPtr(ptr) => { + adder("ptr".into(), format!("{ptr:?}").into_diag_arg(&mut None)); + } + ConstMakeGlobalPtrAlreadyMadeGlobal(alloc) => { + adder("alloc".into(), alloc.into_diag_arg(&mut None)); + } } } } diff --git a/compiler/rustc_const_eval/src/const_eval/eval_queries.rs b/compiler/rustc_const_eval/src/const_eval/eval_queries.rs index 4bd4b49300900..ce72d59b8b0e4 100644 --- a/compiler/rustc_const_eval/src/const_eval/eval_queries.rs +++ b/compiler/rustc_const_eval/src/const_eval/eval_queries.rs @@ -18,7 +18,7 @@ use tracing::{debug, instrument, trace}; use super::{CanAccessMutGlobal, CompileTimeInterpCx, CompileTimeMachine}; use crate::const_eval::CheckAlignment; use crate::interpret::{ - CtfeValidationMode, GlobalId, Immediate, InternKind, InternResult, InterpCx, InterpErrorKind, + CtfeValidationMode, GlobalId, Immediate, InternError, InternKind, InterpCx, InterpErrorKind, InterpResult, MPlaceTy, MemoryKind, OpTy, RefTracking, ReturnContinuation, create_static_alloc, intern_const_alloc_recursive, interp_ok, throw_exhaust, }; @@ -93,25 +93,30 @@ fn eval_body_using_ecx<'tcx, R: InterpretationResult<'tcx>>( // Since evaluation had no errors, validate the resulting constant. const_validate_mplace(ecx, &ret, cid)?; - // Only report this after validation, as validaiton produces much better diagnostics. + // Only report this after validation, as validation produces much better diagnostics. // FIXME: ensure validation always reports this and stop making interning care about it. match intern_result { Ok(()) => {} - Err(InternResult::FoundDanglingPointer) => { + Err(InternError::DanglingPointer) => { throw_inval!(AlreadyReported(ReportedErrorInfo::non_const_eval_error( ecx.tcx .dcx() .emit_err(errors::DanglingPtrInFinal { span: ecx.tcx.span, kind: intern_kind }), ))); } - Err(InternResult::FoundBadMutablePointer) => { + Err(InternError::BadMutablePointer) => { throw_inval!(AlreadyReported(ReportedErrorInfo::non_const_eval_error( ecx.tcx .dcx() .emit_err(errors::MutablePtrInFinal { span: ecx.tcx.span, kind: intern_kind }), ))); } + Err(InternError::ConstAllocNotGlobal) => { + throw_inval!(AlreadyReported(ReportedErrorInfo::non_const_eval_error( + ecx.tcx.dcx().emit_err(errors::ConstHeapPtrInFinal { span: ecx.tcx.span }), + ))); + } } interp_ok(R::make_result(ret, ecx)) diff --git a/compiler/rustc_const_eval/src/const_eval/machine.rs b/compiler/rustc_const_eval/src/const_eval/machine.rs index 52fc898192ade..70ad57b2b11b7 100644 --- a/compiler/rustc_const_eval/src/const_eval/machine.rs +++ b/compiler/rustc_const_eval/src/const_eval/machine.rs @@ -169,13 +169,19 @@ pub type CompileTimeInterpCx<'tcx> = InterpCx<'tcx, CompileTimeMachine<'tcx>>; #[derive(Debug, PartialEq, Eq, Copy, Clone)] pub enum MemoryKind { - Heap, + Heap { + /// Indicates whether `make_global` was called on this allocation. + /// If this is `true`, the allocation must be immutable. + was_made_global: bool, + }, } impl fmt::Display for MemoryKind { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { match self { - MemoryKind::Heap => write!(f, "heap allocation"), + MemoryKind::Heap { was_made_global } => { + write!(f, "heap allocation{}", if *was_made_global { " (made global)" } else { "" }) + } } } } @@ -184,7 +190,7 @@ impl interpret::MayLeak for MemoryKind { #[inline(always)] fn may_leak(self) -> bool { match self { - MemoryKind::Heap => false, + MemoryKind::Heap { was_made_global } => was_made_global, } } } @@ -314,8 +320,6 @@ impl<'tcx> CompileTimeMachine<'tcx> { impl<'tcx> interpret::Machine<'tcx> for CompileTimeMachine<'tcx> { compile_time_machine!(<'tcx>); - type MemoryKind = MemoryKind; - const PANIC_ON_ALLOC_FAIL: bool = false; // will be raised as a proper error #[inline(always)] @@ -420,7 +424,7 @@ impl<'tcx> interpret::Machine<'tcx> for CompileTimeMachine<'tcx> { let ptr = ecx.allocate_ptr( Size::from_bytes(size), align, - interpret::MemoryKind::Machine(MemoryKind::Heap), + interpret::MemoryKind::Machine(MemoryKind::Heap { was_made_global: false }), AllocInit::Uninit, )?; ecx.write_pointer(ptr, dest)?; @@ -453,10 +457,17 @@ impl<'tcx> interpret::Machine<'tcx> for CompileTimeMachine<'tcx> { ecx.deallocate_ptr( ptr, Some((size, align)), - interpret::MemoryKind::Machine(MemoryKind::Heap), + interpret::MemoryKind::Machine(MemoryKind::Heap { was_made_global: false }), )?; } } + + sym::const_make_global => { + let ptr = ecx.read_pointer(&args[0])?; + ecx.make_const_heap_ptr_global(ptr)?; + ecx.write_pointer(ptr, dest)?; + } + // The intrinsic represents whether the value is known to the optimizer (LLVM). // We're not doing any optimizations here, so there is no optimizer that could know the value. // (We know the value here in the machine of course, but this is the runtime of that code, diff --git a/compiler/rustc_const_eval/src/errors.rs b/compiler/rustc_const_eval/src/errors.rs index 49cd713874869..b6a64035261e5 100644 --- a/compiler/rustc_const_eval/src/errors.rs +++ b/compiler/rustc_const_eval/src/errors.rs @@ -43,6 +43,14 @@ pub(crate) struct MutablePtrInFinal { pub kind: InternKind, } +#[derive(Diagnostic)] +#[diag(const_eval_const_heap_ptr_in_final)] +#[note] +pub(crate) struct ConstHeapPtrInFinal { + #[primary_span] + pub span: Span, +} + #[derive(Diagnostic)] #[diag(const_eval_unstable_in_stable_exposed)] pub(crate) struct UnstableInStableExposed { diff --git a/compiler/rustc_const_eval/src/interpret/intern.rs b/compiler/rustc_const_eval/src/interpret/intern.rs index f0f958d069ee8..bb59b9f54186c 100644 --- a/compiler/rustc_const_eval/src/interpret/intern.rs +++ b/compiler/rustc_const_eval/src/interpret/intern.rs @@ -26,21 +26,18 @@ use rustc_middle::ty::layout::TyAndLayout; use rustc_span::def_id::LocalDefId; use tracing::{instrument, trace}; -use super::{ - AllocId, Allocation, InterpCx, MPlaceTy, Machine, MemoryKind, PlaceTy, err_ub, interp_ok, -}; -use crate::const_eval; +use super::{AllocId, Allocation, InterpCx, MPlaceTy, Machine, MemoryKind, PlaceTy, interp_ok}; use crate::const_eval::DummyMachine; -use crate::errors::NestedStaticInThreadLocal; +use crate::{const_eval, errors}; -pub trait CompileTimeMachine<'tcx, T> = Machine< +pub trait CompileTimeMachine<'tcx> = Machine< 'tcx, - MemoryKind = T, + MemoryKind = const_eval::MemoryKind, Provenance = CtfeProvenance, ExtraFnVal = !, FrameExtra = (), AllocExtra = (), - MemoryMap = FxIndexMap, Allocation)>, + MemoryMap = FxIndexMap, Allocation)>, > + HasStaticRootDefId; pub trait HasStaticRootDefId { @@ -62,18 +59,32 @@ impl HasStaticRootDefId for const_eval::CompileTimeMachine<'_> { /// already mutable (as a sanity check). /// /// Returns an iterator over all relocations referred to by this allocation. -fn intern_shallow<'tcx, T, M: CompileTimeMachine<'tcx, T>>( +fn intern_shallow<'tcx, M: CompileTimeMachine<'tcx>>( ecx: &mut InterpCx<'tcx, M>, alloc_id: AllocId, mutability: Mutability, disambiguator: Option<&mut DisambiguatorState>, -) -> Result + 'tcx, ()> { +) -> Result + 'tcx, InternError> { trace!("intern_shallow {:?}", alloc_id); // remove allocation // FIXME(#120456) - is `swap_remove` correct? - let Some((_kind, mut alloc)) = ecx.memory.alloc_map.swap_remove(&alloc_id) else { - return Err(()); + let Some((kind, mut alloc)) = ecx.memory.alloc_map.swap_remove(&alloc_id) else { + return Err(InternError::DanglingPointer); }; + + match kind { + MemoryKind::Machine(const_eval::MemoryKind::Heap { was_made_global }) => { + if !was_made_global { + // Attempting to intern a `const_allocate`d pointer that was not made global via + // `const_make_global`. We want to error here, but we have to first put the + // allocation back into the `alloc_map` to keep things in a consistent state. + ecx.memory.alloc_map.insert(alloc_id, (kind, alloc)); + return Err(InternError::ConstAllocNotGlobal); + } + } + MemoryKind::Stack | MemoryKind::CallerLocation => {} + } + // Set allocation mutability as appropriate. This is used by LLVM to put things into // read-only memory, and also by Miri when evaluating other globals that // access this one. @@ -99,7 +110,7 @@ fn intern_shallow<'tcx, T, M: CompileTimeMachine<'tcx, T>>( } else { ecx.tcx.set_alloc_id_memory(alloc_id, alloc); } - Ok(alloc.0.0.provenance().ptrs().iter().map(|&(_, prov)| prov)) + Ok(alloc.inner().provenance().ptrs().iter().map(|&(_, prov)| prov)) } /// Creates a new `DefId` and feeds all the right queries to make this `DefId` @@ -125,7 +136,7 @@ fn intern_as_new_static<'tcx>( tcx.set_nested_alloc_id_static(alloc_id, feed.def_id()); if tcx.is_thread_local_static(static_id.into()) { - tcx.dcx().emit_err(NestedStaticInThreadLocal { span: tcx.def_span(static_id) }); + tcx.dcx().emit_err(errors::NestedStaticInThreadLocal { span: tcx.def_span(static_id) }); } // These do not inherit the codegen attrs of the parent static allocation, since @@ -151,9 +162,10 @@ pub enum InternKind { } #[derive(Debug)] -pub enum InternResult { - FoundBadMutablePointer, - FoundDanglingPointer, +pub enum InternError { + BadMutablePointer, + DanglingPointer, + ConstAllocNotGlobal, } /// Intern `ret` and everything it references. @@ -163,11 +175,11 @@ pub enum InternResult { /// /// For `InternKind::Static` the root allocation will not be interned, but must be handled by the caller. #[instrument(level = "debug", skip(ecx))] -pub fn intern_const_alloc_recursive<'tcx, M: CompileTimeMachine<'tcx, const_eval::MemoryKind>>( +pub fn intern_const_alloc_recursive<'tcx, M: CompileTimeMachine<'tcx>>( ecx: &mut InterpCx<'tcx, M>, intern_kind: InternKind, ret: &MPlaceTy<'tcx>, -) -> Result<(), InternResult> { +) -> Result<(), InternError> { let mut disambiguator = DisambiguatorState::new(); // We are interning recursively, and for mutability we are distinguishing the "root" allocation @@ -181,7 +193,7 @@ pub fn intern_const_alloc_recursive<'tcx, M: CompileTimeMachine<'tcx, const_eval } InternKind::Static(Mutability::Not) => { ( - // Outermost allocation is mutable if `!Freeze`. + // Outermost allocation is mutable if `!Freeze` i.e. contains interior mutable types. if ret.layout.ty.is_freeze(*ecx.tcx, ecx.typing_env) { Mutability::Not } else { @@ -224,6 +236,7 @@ pub fn intern_const_alloc_recursive<'tcx, M: CompileTimeMachine<'tcx, const_eval // We want to first report "dangling" and then "mutable", so we need to delay reporting these // errors. let mut result = Ok(()); + let mut found_bad_mutable_ptr = false; // Keep interning as long as there are things to intern. // We show errors if there are dangling pointers, or mutable pointers in immutable contexts @@ -278,18 +291,7 @@ pub fn intern_const_alloc_recursive<'tcx, M: CompileTimeMachine<'tcx, const_eval // when there is memory there that someone might expect to be mutable, but we make it immutable. let dangling = !is_already_global && !ecx.memory.alloc_map.contains_key(&alloc_id); if !dangling { - // Found a mutable pointer inside a const where inner allocations should be - // immutable. - if !ecx.tcx.sess.opts.unstable_opts.unleash_the_miri_inside_of_you { - span_bug!( - ecx.tcx.span, - "the static const safety checks accepted a mutable pointer they should not have accepted" - ); - } - // Prefer dangling pointer errors over mutable pointer errors - if result.is_ok() { - result = Err(InternResult::FoundBadMutablePointer); - } + found_bad_mutable_ptr = true; } } if ecx.tcx.try_get_global_alloc(alloc_id).is_some() { @@ -310,18 +312,31 @@ pub fn intern_const_alloc_recursive<'tcx, M: CompileTimeMachine<'tcx, const_eval just_interned.insert(alloc_id); match intern_shallow(ecx, alloc_id, inner_mutability, Some(&mut disambiguator)) { Ok(nested) => todo.extend(nested), - Err(()) => { - ecx.tcx.dcx().delayed_bug("found dangling pointer during const interning"); - result = Err(InternResult::FoundDanglingPointer); + Err(err) => { + ecx.tcx.dcx().delayed_bug("error during const interning"); + result = Err(err); } } } + if found_bad_mutable_ptr && result.is_ok() { + // We found a mutable pointer inside a const where inner allocations should be immutable, + // and there was no other error. This should usually never happen! However, this can happen + // in unleash-miri mode, so report it as a normal error then. + if ecx.tcx.sess.opts.unstable_opts.unleash_the_miri_inside_of_you { + result = Err(InternError::BadMutablePointer); + } else { + span_bug!( + ecx.tcx.span, + "the static const safety checks accepted a mutable pointer they should not have accepted" + ); + } + } result } /// Intern `ret`. This function assumes that `ret` references no other allocation. #[instrument(level = "debug", skip(ecx))] -pub fn intern_const_alloc_for_constprop<'tcx, T, M: CompileTimeMachine<'tcx, T>>( +pub fn intern_const_alloc_for_constprop<'tcx, M: CompileTimeMachine<'tcx>>( ecx: &mut InterpCx<'tcx, M>, alloc_id: AllocId, ) -> InterpResult<'tcx, ()> { @@ -330,10 +345,7 @@ pub fn intern_const_alloc_for_constprop<'tcx, T, M: CompileTimeMachine<'tcx, T>> return interp_ok(()); } // Move allocation to `tcx`. - if let Some(_) = intern_shallow(ecx, alloc_id, Mutability::Not, None) - .map_err(|()| err_ub!(DeadLocal))? - .next() - { + if let Some(_) = intern_shallow(ecx, alloc_id, Mutability::Not, None).unwrap().next() { // We are not doing recursive interning, so we don't currently support provenance. // (If this assertion ever triggers, we should just implement a // proper recursive interning loop -- or just call `intern_const_alloc_recursive`. diff --git a/compiler/rustc_const_eval/src/interpret/machine.rs b/compiler/rustc_const_eval/src/interpret/machine.rs index d150ed69250e5..e981f3973ae63 100644 --- a/compiler/rustc_const_eval/src/interpret/machine.rs +++ b/compiler/rustc_const_eval/src/interpret/machine.rs @@ -649,6 +649,7 @@ pub macro compile_time_machine(<$tcx: lifetime>) { type ExtraFnVal = !; + type MemoryKind = $crate::const_eval::MemoryKind; type MemoryMap = rustc_data_structures::fx::FxIndexMap, Allocation)>; const GLOBAL_KIND: Option = None; // no copying of globals from `tcx` to machine memory diff --git a/compiler/rustc_const_eval/src/interpret/memory.rs b/compiler/rustc_const_eval/src/interpret/memory.rs index 6414821e21d02..5f9f43a320b59 100644 --- a/compiler/rustc_const_eval/src/interpret/memory.rs +++ b/compiler/rustc_const_eval/src/interpret/memory.rs @@ -26,6 +26,7 @@ use super::{ Misalignment, Pointer, PointerArithmetic, Provenance, Scalar, alloc_range, err_ub, err_ub_custom, interp_ok, throw_ub, throw_ub_custom, throw_unsup, throw_unsup_format, }; +use crate::const_eval::ConstEvalErrKind; use crate::fluent_generated as fluent; #[derive(Debug, PartialEq, Copy, Clone)] @@ -311,6 +312,51 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> { interp_ok(new_ptr) } + /// Mark the `const_allocate`d allocation `ptr` points to as immutable so we can intern it. + pub fn make_const_heap_ptr_global( + &mut self, + ptr: Pointer>, + ) -> InterpResult<'tcx> + where + M: Machine<'tcx, MemoryKind = crate::const_eval::MemoryKind, Provenance = CtfeProvenance>, + { + let (alloc_id, offset, _) = self.ptr_get_alloc_id(ptr, 0)?; + if offset.bytes() != 0 { + return Err(ConstEvalErrKind::ConstMakeGlobalWithOffset(ptr)).into(); + } + + if matches!(self.tcx.try_get_global_alloc(alloc_id), Some(_)) { + // This points to something outside the current interpreter. + return Err(ConstEvalErrKind::ConstMakeGlobalPtrIsNonHeap(ptr)).into(); + } + + // If we can't find it in `alloc_map` it must be dangling (because we don't use + // `extra_fn_ptr_map` in const-eval). + let (kind, alloc) = self + .memory + .alloc_map + .get_mut_or(alloc_id, || Err(ConstEvalErrKind::ConstMakeGlobalWithDanglingPtr(ptr)))?; + + // Ensure this is actually a *heap* allocation, and record it as made-global. + match kind { + MemoryKind::Stack | MemoryKind::CallerLocation => { + return Err(ConstEvalErrKind::ConstMakeGlobalPtrIsNonHeap(ptr)).into(); + } + MemoryKind::Machine(crate::const_eval::MemoryKind::Heap { was_made_global }) => { + if *was_made_global { + return Err(ConstEvalErrKind::ConstMakeGlobalPtrAlreadyMadeGlobal(alloc_id)) + .into(); + } + *was_made_global = true; + } + } + + // Prevent further mutation, this is now an immutable global. + alloc.mutability = Mutability::Not; + + interp_ok(()) + } + #[instrument(skip(self), level = "debug")] pub fn deallocate_ptr( &mut self, diff --git a/compiler/rustc_const_eval/src/interpret/mod.rs b/compiler/rustc_const_eval/src/interpret/mod.rs index 2fc372dd01978..2f365ec77b33e 100644 --- a/compiler/rustc_const_eval/src/interpret/mod.rs +++ b/compiler/rustc_const_eval/src/interpret/mod.rs @@ -26,7 +26,7 @@ pub use self::call::FnArg; pub use self::eval_context::{InterpCx, format_interp_error}; use self::eval_context::{from_known_layout, mir_assign_valid_types}; pub use self::intern::{ - HasStaticRootDefId, InternKind, InternResult, intern_const_alloc_for_constprop, + HasStaticRootDefId, InternError, InternKind, intern_const_alloc_for_constprop, intern_const_alloc_recursive, }; pub use self::machine::{AllocMap, Machine, MayLeak, ReturnAction, compile_time_machine}; diff --git a/compiler/rustc_const_eval/src/interpret/validity.rs b/compiler/rustc_const_eval/src/interpret/validity.rs index fc44490c96d37..62f591ceaa910 100644 --- a/compiler/rustc_const_eval/src/interpret/validity.rs +++ b/compiler/rustc_const_eval/src/interpret/validity.rs @@ -558,7 +558,15 @@ impl<'rt, 'tcx, M: Machine<'tcx>> ValidityVisitor<'rt, 'tcx, M> { { // Everything should be already interned. let Some(global_alloc) = self.ecx.tcx.try_get_global_alloc(alloc_id) else { - assert!(self.ecx.memory.alloc_map.get(alloc_id).is_none()); + if self.ecx.memory.alloc_map.contains_key(&alloc_id) { + // This can happen when interning didn't complete due to, e.g. + // missing `make_global`. This must mean other errors are already + // being reported. + self.ecx.tcx.dcx().delayed_bug( + "interning did not complete, there should be an error", + ); + return interp_ok(()); + } // We can't have *any* references to non-existing allocations in const-eval // as the rest of rustc isn't happy with them... so we throw an error, even // though for zero-sized references this isn't really UB. diff --git a/compiler/rustc_const_eval/src/util/check_validity_requirement.rs b/compiler/rustc_const_eval/src/util/check_validity_requirement.rs index 4ca39bbc68ec2..b1f2959875051 100644 --- a/compiler/rustc_const_eval/src/util/check_validity_requirement.rs +++ b/compiler/rustc_const_eval/src/util/check_validity_requirement.rs @@ -52,9 +52,9 @@ fn check_validity_requirement_strict<'tcx>( let mut cx = InterpCx::new(cx.tcx(), DUMMY_SP, cx.typing_env, machine); - let allocated = cx - .allocate(ty, MemoryKind::Machine(crate::const_eval::MemoryKind::Heap)) - .expect("OOM: failed to allocate for uninit check"); + // It doesn't really matter which `MemoryKind` we use here, `Stack` is the least wrong. + let allocated = + cx.allocate(ty, MemoryKind::Stack).expect("OOM: failed to allocate for uninit check"); if kind == ValidityRequirement::Zero { cx.write_bytes_ptr( @@ -184,9 +184,10 @@ pub(crate) fn validate_scalar_in_layout<'tcx>( let Ok(layout) = cx.layout_of(ty) else { bug!("could not compute layout of {scalar:?}:{ty:?}") }; - let allocated = cx - .allocate(layout, MemoryKind::Machine(crate::const_eval::MemoryKind::Heap)) - .expect("OOM: failed to allocate for uninit check"); + + // It doesn't really matter which `MemoryKind` we use here, `Stack` is the least wrong. + let allocated = + cx.allocate(layout, MemoryKind::Stack).expect("OOM: failed to allocate for uninit check"); cx.write_scalar(scalar, &allocated).unwrap(); diff --git a/compiler/rustc_hir_analysis/src/check/intrinsic.rs b/compiler/rustc_hir_analysis/src/check/intrinsic.rs index dcab6ef1c5a5f..6e5fe3823ab51 100644 --- a/compiler/rustc_hir_analysis/src/check/intrinsic.rs +++ b/compiler/rustc_hir_analysis/src/check/intrinsic.rs @@ -422,6 +422,9 @@ pub(crate) fn check_intrinsic_type( vec![Ty::new_mut_ptr(tcx, tcx.types.u8), tcx.types.usize, tcx.types.usize], tcx.types.unit, ), + sym::const_make_global => { + (0, 0, vec![Ty::new_mut_ptr(tcx, tcx.types.u8)], Ty::new_imm_ptr(tcx, tcx.types.u8)) + } sym::ptr_offset_from => ( 1, diff --git a/compiler/rustc_middle/src/mir/interpret/error.rs b/compiler/rustc_middle/src/mir/interpret/error.rs index 71e0c943fbbb2..3e68afbfabd04 100644 --- a/compiler/rustc_middle/src/mir/interpret/error.rs +++ b/compiler/rustc_middle/src/mir/interpret/error.rs @@ -257,7 +257,7 @@ pub enum InvalidProgramInfo<'tcx> { /// Details of why a pointer had to be in-bounds. #[derive(Debug, Copy, Clone)] pub enum CheckInAllocMsg { - /// We are access memory. + /// We are accessing memory. MemoryAccess, /// We are doing pointer arithmetic. InboundsPointerArithmetic, diff --git a/compiler/rustc_span/src/symbol.rs b/compiler/rustc_span/src/symbol.rs index 8b12edf426c1b..599ef9aba2abb 100644 --- a/compiler/rustc_span/src/symbol.rs +++ b/compiler/rustc_span/src/symbol.rs @@ -715,6 +715,7 @@ symbols! { const_indexing, const_let, const_loop, + const_make_global, const_mut_refs, const_panic, const_panic_fmt, diff --git a/library/alloc/src/boxed/thin.rs b/library/alloc/src/boxed/thin.rs index 21425b9846e42..1cce36606d2c0 100644 --- a/library/alloc/src/boxed/thin.rs +++ b/library/alloc/src/boxed/thin.rs @@ -5,7 +5,7 @@ use core::error::Error; use core::fmt::{self, Debug, Display, Formatter}; #[cfg(not(no_global_oom_handling))] -use core::intrinsics::const_allocate; +use core::intrinsics::{const_allocate, const_make_global}; use core::marker::PhantomData; #[cfg(not(no_global_oom_handling))] use core::marker::Unsize; @@ -340,9 +340,10 @@ impl WithHeader { alloc.add(metadata_offset).cast(); // SAFETY: `*metadata_ptr` is within the allocation. metadata_ptr.write(ptr::metadata::(ptr::dangling::() as *const Dyn)); - + // SAFETY: valid heap allocation + const_make_global(alloc); // SAFETY: we have just written the metadata. - &*(metadata_ptr) + &*metadata_ptr } }; diff --git a/library/core/src/intrinsics/mod.rs b/library/core/src/intrinsics/mod.rs index c2e4b751c65f3..038c705d5b509 100644 --- a/library/core/src/intrinsics/mod.rs +++ b/library/core/src/intrinsics/mod.rs @@ -2533,6 +2533,15 @@ pub const unsafe fn const_deallocate(_ptr: *mut u8, _size: usize, _align: usize) // Runtime NOP } +#[rustc_const_unstable(feature = "const_heap", issue = "79597")] +#[rustc_nounwind] +#[rustc_intrinsic] +#[miri::intrinsic_fallback_is_spec] +pub const unsafe fn const_make_global(ptr: *mut u8) -> *const u8 { + // const eval overrides this function; at runtime, it is a NOP. + ptr +} + /// Returns whether we should perform contract-checking at runtime. /// /// This is meant to be similar to the ub_checks intrinsic, in terms diff --git a/tests/crashes/const_mut_ref_check_bypass.rs b/tests/crashes/const_mut_ref_check_bypass.rs deleted file mode 100644 index 6234536c72beb..0000000000000 --- a/tests/crashes/const_mut_ref_check_bypass.rs +++ /dev/null @@ -1,11 +0,0 @@ -// Version of `tests/ui/consts/const-eval/heap/alloc_intrinsic_untyped.rs` without the flag that -// suppresses the ICE. -//@ known-bug: #129233 -#![feature(core_intrinsics)] -#![feature(const_heap)] -#![feature(const_mut_refs)] -use std::intrinsics; - -const BAR: *mut i32 = unsafe { intrinsics::const_allocate(4, 4) as *mut i32 }; - -fn main() {} diff --git a/tests/ui/consts/const-eval/heap/alloc_intrinsic_nontransient.rs b/tests/ui/consts/const-eval/heap/alloc_intrinsic_nontransient.rs index 83ed496ac2c25..af24e463b5059 100644 --- a/tests/ui/consts/const-eval/heap/alloc_intrinsic_nontransient.rs +++ b/tests/ui/consts/const-eval/heap/alloc_intrinsic_nontransient.rs @@ -8,11 +8,11 @@ const FOO_RAW: *const i32 = foo(); const fn foo() -> &'static i32 { let t = unsafe { - let i = intrinsics::const_allocate(4, 4) as * mut i32; + let i = intrinsics::const_allocate(4, 4) as *mut i32; *i = 20; i }; - unsafe { &*t } + unsafe { &*(intrinsics::const_make_global(t as *mut u8) as *const i32) } } fn main() { assert_eq!(*FOO, 20); diff --git a/tests/ui/consts/const-eval/heap/alloc_intrinsic_uninit.32bit.stderr b/tests/ui/consts/const-eval/heap/alloc_intrinsic_uninit.32bit.stderr index 11ed0841a0039..a8c7ee93971ec 100644 --- a/tests/ui/consts/const-eval/heap/alloc_intrinsic_uninit.32bit.stderr +++ b/tests/ui/consts/const-eval/heap/alloc_intrinsic_uninit.32bit.stderr @@ -1,7 +1,7 @@ error[E0080]: constructing invalid value at .: encountered uninitialized memory, but expected an integer --> $DIR/alloc_intrinsic_uninit.rs:7:1 | -LL | const BAR: &i32 = unsafe { &*(intrinsics::const_allocate(4, 4) as *mut i32) }; +LL | const BAR: &i32 = unsafe { | ^^^^^^^^^^^^^^^ it is undefined behavior to use this value | = 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. diff --git a/tests/ui/consts/const-eval/heap/alloc_intrinsic_uninit.64bit.stderr b/tests/ui/consts/const-eval/heap/alloc_intrinsic_uninit.64bit.stderr index 691bde87d2f21..47e1c22cc2c12 100644 --- a/tests/ui/consts/const-eval/heap/alloc_intrinsic_uninit.64bit.stderr +++ b/tests/ui/consts/const-eval/heap/alloc_intrinsic_uninit.64bit.stderr @@ -1,7 +1,7 @@ error[E0080]: constructing invalid value at .: encountered uninitialized memory, but expected an integer --> $DIR/alloc_intrinsic_uninit.rs:7:1 | -LL | const BAR: &i32 = unsafe { &*(intrinsics::const_allocate(4, 4) as *mut i32) }; +LL | const BAR: &i32 = unsafe { | ^^^^^^^^^^^^^^^ it is undefined behavior to use this value | = 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. diff --git a/tests/ui/consts/const-eval/heap/alloc_intrinsic_uninit.rs b/tests/ui/consts/const-eval/heap/alloc_intrinsic_uninit.rs index ffc35ca1ddceb..c54115de2045d 100644 --- a/tests/ui/consts/const-eval/heap/alloc_intrinsic_uninit.rs +++ b/tests/ui/consts/const-eval/heap/alloc_intrinsic_uninit.rs @@ -4,6 +4,8 @@ #![feature(const_heap)] use std::intrinsics; -const BAR: &i32 = unsafe { &*(intrinsics::const_allocate(4, 4) as *mut i32) }; -//~^ ERROR: uninitialized memory +const BAR: &i32 = unsafe { //~ ERROR: uninitialized memory + // Make the pointer immutable to avoid errors related to mutable pointers in constants. + &*(intrinsics::const_make_global(intrinsics::const_allocate(4, 4)) as *const i32) +}; fn main() {} diff --git a/tests/ui/consts/const-eval/heap/alloc_intrinsic_untyped.rs b/tests/ui/consts/const-eval/heap/alloc_intrinsic_untyped.rs deleted file mode 100644 index 26cb69e458b61..0000000000000 --- a/tests/ui/consts/const-eval/heap/alloc_intrinsic_untyped.rs +++ /dev/null @@ -1,11 +0,0 @@ -// We unleash Miri here since this test demonstrates code that bypasses the checks against interning -// mutable pointers, which currently ICEs. Unleashing Miri silences the ICE. -//@ compile-flags: -Zunleash-the-miri-inside-of-you -#![feature(core_intrinsics)] -#![feature(const_heap)] -use std::intrinsics; - -const BAR: *mut i32 = unsafe { intrinsics::const_allocate(4, 4) as *mut i32 }; -//~^ error: mutable pointer in final value of constant - -fn main() {} diff --git a/tests/ui/consts/const-eval/heap/alloc_intrinsic_untyped.stderr b/tests/ui/consts/const-eval/heap/alloc_intrinsic_untyped.stderr deleted file mode 100644 index 0dc49dc3cd864..0000000000000 --- a/tests/ui/consts/const-eval/heap/alloc_intrinsic_untyped.stderr +++ /dev/null @@ -1,8 +0,0 @@ -error: encountered mutable pointer in final value of constant - --> $DIR/alloc_intrinsic_untyped.rs:8:1 - | -LL | const BAR: *mut i32 = unsafe { intrinsics::const_allocate(4, 4) as *mut i32 }; - | ^^^^^^^^^^^^^^^^^^^ - -error: aborting due to 1 previous error - diff --git a/tests/ui/consts/const-eval/heap/dealloc_intrinsic.rs b/tests/ui/consts/const-eval/heap/dealloc_intrinsic.rs index 3cc035c66d33f..515e12d2b7715 100644 --- a/tests/ui/consts/const-eval/heap/dealloc_intrinsic.rs +++ b/tests/ui/consts/const-eval/heap/dealloc_intrinsic.rs @@ -12,7 +12,7 @@ const _X: () = unsafe { const Y: &u32 = unsafe { let ptr = intrinsics::const_allocate(4, 4) as *mut u32; *ptr = 42; - &*ptr + &*(intrinsics::const_make_global(ptr as *mut u8) as *const u32) }; const Z: &u32 = &42; diff --git a/tests/ui/consts/const-eval/heap/make-global-dangling.rs b/tests/ui/consts/const-eval/heap/make-global-dangling.rs new file mode 100644 index 0000000000000..f4c5929bc416d --- /dev/null +++ b/tests/ui/consts/const-eval/heap/make-global-dangling.rs @@ -0,0 +1,18 @@ +// Ensure that we can't call `const_make_global` on dangling pointers. + +#![feature(core_intrinsics)] +#![feature(const_heap)] + +use std::intrinsics; + +const Y: &u32 = unsafe { + &*(intrinsics::const_make_global(std::ptr::null_mut()) as *const u32) + //~^ error: pointer not dereferenceable +}; + +const Z: &u32 = unsafe { + &*(intrinsics::const_make_global(std::ptr::dangling_mut()) as *const u32) + //~^ error: pointer not dereferenceable +}; + +fn main() {} diff --git a/tests/ui/consts/const-eval/heap/make-global-dangling.stderr b/tests/ui/consts/const-eval/heap/make-global-dangling.stderr new file mode 100644 index 0000000000000..48c2796d0bf21 --- /dev/null +++ b/tests/ui/consts/const-eval/heap/make-global-dangling.stderr @@ -0,0 +1,15 @@ +error[E0080]: pointer not dereferenceable: pointer must point to some allocation, but got null pointer + --> $DIR/make-global-dangling.rs:9:8 + | +LL | &*(intrinsics::const_make_global(std::ptr::null_mut()) as *const u32) + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ evaluation of `Y` failed here + +error[E0080]: pointer not dereferenceable: pointer must point to some allocation, but got 0x1[noalloc] which is a dangling pointer (it has no provenance) + --> $DIR/make-global-dangling.rs:14:8 + | +LL | &*(intrinsics::const_make_global(std::ptr::dangling_mut()) as *const u32) + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ evaluation of `Z` failed here + +error: aborting due to 2 previous errors + +For more information about this error, try `rustc --explain E0080`. diff --git a/tests/ui/consts/const-eval/heap/make-global-other.rs b/tests/ui/consts/const-eval/heap/make-global-other.rs new file mode 100644 index 0000000000000..4e2a59de13edc --- /dev/null +++ b/tests/ui/consts/const-eval/heap/make-global-other.rs @@ -0,0 +1,15 @@ +// Ensure that we can't call `const_make_global` on pointers not in the current interpreter. + +#![feature(core_intrinsics)] +#![feature(const_heap)] + +use std::intrinsics; + +const X: &i32 = &0; + +const Y: &i32 = unsafe { + &*(intrinsics::const_make_global(X as *const i32 as *mut u8) as *const i32) + //~^ error: pointer passed to `const_make_global` does not point to a heap allocation: ALLOC0 +}; + +fn main() {} diff --git a/tests/ui/consts/const-eval/heap/make-global-other.stderr b/tests/ui/consts/const-eval/heap/make-global-other.stderr new file mode 100644 index 0000000000000..ed0d768cf379f --- /dev/null +++ b/tests/ui/consts/const-eval/heap/make-global-other.stderr @@ -0,0 +1,9 @@ +error[E0080]: pointer passed to `const_make_global` does not point to a heap allocation: ALLOC0 + --> $DIR/make-global-other.rs:11:8 + | +LL | &*(intrinsics::const_make_global(X as *const i32 as *mut u8) as *const i32) + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ evaluation of `Y` failed here + +error: aborting due to 1 previous error + +For more information about this error, try `rustc --explain E0080`. diff --git a/tests/ui/consts/const-eval/heap/make-global-twice.rs b/tests/ui/consts/const-eval/heap/make-global-twice.rs new file mode 100644 index 0000000000000..0cd617cea3e6e --- /dev/null +++ b/tests/ui/consts/const-eval/heap/make-global-twice.rs @@ -0,0 +1,18 @@ +// Ensure that we can't call `const_make_global` twice. + +#![feature(core_intrinsics)] +#![feature(const_heap)] + +use std::intrinsics; + +const Y: &i32 = unsafe { + let ptr = intrinsics::const_allocate(4, 4); + let i = ptr as *mut i32; + *i = 20; + intrinsics::const_make_global(ptr); + intrinsics::const_make_global(ptr); + //~^ error: attempting to call `const_make_global` twice on the same allocation ALLOC0 + &*i +}; + +fn main() {} diff --git a/tests/ui/consts/const-eval/heap/make-global-twice.stderr b/tests/ui/consts/const-eval/heap/make-global-twice.stderr new file mode 100644 index 0000000000000..95cdb9694d8b9 --- /dev/null +++ b/tests/ui/consts/const-eval/heap/make-global-twice.stderr @@ -0,0 +1,9 @@ +error[E0080]: attempting to call `const_make_global` twice on the same allocation ALLOC0 + --> $DIR/make-global-twice.rs:13:5 + | +LL | intrinsics::const_make_global(ptr); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ evaluation of `Y` failed here + +error: aborting due to 1 previous error + +For more information about this error, try `rustc --explain E0080`. diff --git a/tests/ui/consts/const-eval/heap/make-global.rs b/tests/ui/consts/const-eval/heap/make-global.rs new file mode 100644 index 0000000000000..b26fe2434ab8b --- /dev/null +++ b/tests/ui/consts/const-eval/heap/make-global.rs @@ -0,0 +1,21 @@ +//@ run-pass +#![feature(core_intrinsics)] +#![feature(const_heap)] +use std::intrinsics; + +const FOO: &i32 = foo(); +const FOO_RAW: *const i32 = foo(); + +const fn foo() -> &'static i32 { + unsafe { + let ptr = intrinsics::const_allocate(4, 4); + let t = ptr as *mut i32; + *t = 20; + intrinsics::const_make_global(ptr); + &*t + } +} +fn main() { + assert_eq!(*FOO, 20); + assert_eq!(unsafe { *FOO_RAW }, 20); +} diff --git a/tests/ui/consts/const-eval/heap/ptr_made_global_mutated.rs b/tests/ui/consts/const-eval/heap/ptr_made_global_mutated.rs new file mode 100644 index 0000000000000..bea2a5949c261 --- /dev/null +++ b/tests/ui/consts/const-eval/heap/ptr_made_global_mutated.rs @@ -0,0 +1,15 @@ +// Ensure that once an allocation is "made global", we can no longer mutate it. +#![feature(core_intrinsics)] +#![feature(const_heap)] +use std::intrinsics; + +const A: &u8 = unsafe { + let ptr = intrinsics::const_allocate(1, 1); + *ptr = 1; + let ptr: *const u8 = intrinsics::const_make_global(ptr); + *(ptr as *mut u8) = 2; + //~^ error: writing to ALLOC0 which is read-only + &*ptr +}; + +fn main() {} diff --git a/tests/ui/consts/const-eval/heap/ptr_made_global_mutated.stderr b/tests/ui/consts/const-eval/heap/ptr_made_global_mutated.stderr new file mode 100644 index 0000000000000..0e88ea77d1ca0 --- /dev/null +++ b/tests/ui/consts/const-eval/heap/ptr_made_global_mutated.stderr @@ -0,0 +1,9 @@ +error[E0080]: writing to ALLOC0 which is read-only + --> $DIR/ptr_made_global_mutated.rs:10:5 + | +LL | *(ptr as *mut u8) = 2; + | ^^^^^^^^^^^^^^^^^^^^^ evaluation of `A` failed here + +error: aborting due to 1 previous error + +For more information about this error, try `rustc --explain E0080`. diff --git a/tests/ui/consts/const-eval/heap/ptr_not_made_global.rs b/tests/ui/consts/const-eval/heap/ptr_not_made_global.rs new file mode 100644 index 0000000000000..6980e92c21896 --- /dev/null +++ b/tests/ui/consts/const-eval/heap/ptr_not_made_global.rs @@ -0,0 +1,24 @@ +// Ensure that we reject interning `const_allocate`d allocations in the final value of constants +// if they have not been made global through `const_make_global`. The pointers are made *immutable* +// to focus the test on the missing `make_global`; `ptr_not_made_global_mut.rs` covers the case +// where the pointer remains mutable. + +#![feature(core_intrinsics)] +#![feature(const_heap)] +use std::intrinsics; + +const FOO: &i32 = foo(); +//~^ error: encountered `const_allocate` pointer in final value that was not made global +const FOO_RAW: *const i32 = foo(); +//~^ error: encountered `const_allocate` pointer in final value that was not made global + +const fn foo() -> &'static i32 { + let t = unsafe { + let i = intrinsics::const_allocate(4, 4) as *mut i32; + *i = 20; + i + }; + unsafe { &*t } +} + +fn main() {} diff --git a/tests/ui/consts/const-eval/heap/ptr_not_made_global.stderr b/tests/ui/consts/const-eval/heap/ptr_not_made_global.stderr new file mode 100644 index 0000000000000..cb2bb1e8cd852 --- /dev/null +++ b/tests/ui/consts/const-eval/heap/ptr_not_made_global.stderr @@ -0,0 +1,18 @@ +error: encountered `const_allocate` pointer in final value that was not made global + --> $DIR/ptr_not_made_global.rs:10:1 + | +LL | const FOO: &i32 = foo(); + | ^^^^^^^^^^^^^^^ + | + = note: use `const_make_global` to make allocated pointers immutable before returning + +error: encountered `const_allocate` pointer in final value that was not made global + --> $DIR/ptr_not_made_global.rs:12:1 + | +LL | const FOO_RAW: *const i32 = foo(); + | ^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: use `const_make_global` to make allocated pointers immutable before returning + +error: aborting due to 2 previous errors + diff --git a/tests/ui/consts/const-eval/heap/ptr_not_made_global_mut.rs b/tests/ui/consts/const-eval/heap/ptr_not_made_global_mut.rs new file mode 100644 index 0000000000000..e44a3f7a23c2c --- /dev/null +++ b/tests/ui/consts/const-eval/heap/ptr_not_made_global_mut.rs @@ -0,0 +1,11 @@ +// Ensure that we reject interning `const_allocate`d allocations in the final value of constants +// if they have not been made global through `const_make_global`. This covers the case where the +// pointer is even still mutable, which used to ICE. +#![feature(core_intrinsics)] +#![feature(const_heap)] +use std::intrinsics; + +const BAR: *mut i32 = unsafe { intrinsics::const_allocate(4, 4) as *mut i32 }; +//~^ error: encountered `const_allocate` pointer in final value that was not made global + +fn main() {} diff --git a/tests/ui/consts/const-eval/heap/ptr_not_made_global_mut.stderr b/tests/ui/consts/const-eval/heap/ptr_not_made_global_mut.stderr new file mode 100644 index 0000000000000..2445ce633d6ff --- /dev/null +++ b/tests/ui/consts/const-eval/heap/ptr_not_made_global_mut.stderr @@ -0,0 +1,10 @@ +error: encountered `const_allocate` pointer in final value that was not made global + --> $DIR/ptr_not_made_global_mut.rs:8:1 + | +LL | const BAR: *mut i32 = unsafe { intrinsics::const_allocate(4, 4) as *mut i32 }; + | ^^^^^^^^^^^^^^^^^^^ + | + = note: use `const_make_global` to make allocated pointers immutable before returning + +error: aborting due to 1 previous error +