diff options
Diffstat (limited to 'compiler/rustc_const_eval')
| -rw-r--r-- | compiler/rustc_const_eval/messages.ftl | 11 | ||||
| -rw-r--r-- | compiler/rustc_const_eval/src/const_eval/error.rs | 32 | ||||
| -rw-r--r-- | compiler/rustc_const_eval/src/const_eval/eval_queries.rs | 2 | ||||
| -rw-r--r-- | compiler/rustc_const_eval/src/const_eval/machine.rs | 19 | ||||
| -rw-r--r-- | compiler/rustc_const_eval/src/errors.rs | 8 | ||||
| -rw-r--r-- | compiler/rustc_const_eval/src/interpret/intern.rs | 58 | ||||
| -rw-r--r-- | compiler/rustc_const_eval/src/interpret/memory.rs | 44 | ||||
| -rw-r--r-- | compiler/rustc_const_eval/src/util/check_validity_requirement.rs | 10 |
8 files changed, 166 insertions, 18 deletions
diff --git a/compiler/rustc_const_eval/messages.ftl b/compiler/rustc_const_eval/messages.ftl index b767ca9a3c2..04637884011 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/error.rs b/compiler/rustc_const_eval/src/const_eval/error.rs index 08fc03d9c46..5b07b7c13c1 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}; @@ -22,8 +22,22 @@ pub enum ConstEvalErrKind { ModifiedGlobal, RecursiveStatic, AssertFailure(AssertKind<ConstInt>), - 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(String), + /// Called `const_make_global` on a dangling pointer. + ConstMakeGlobalWithDanglingPtr(String), + /// Called `const_make_global` on a pointer that does not start at the + /// beginning of an object. + ConstMakeGlobalWithOffset(String), } 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<Self>, 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(), 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 4bd4b493009..32209ff4367 100644 --- a/compiler/rustc_const_eval/src/const_eval/eval_queries.rs +++ b/compiler/rustc_const_eval/src/const_eval/eval_queries.rs @@ -93,7 +93,7 @@ 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 { diff --git a/compiler/rustc_const_eval/src/const_eval/machine.rs b/compiler/rustc_const_eval/src/const_eval/machine.rs index 52fc898192a..4e952b043fb 100644 --- a/compiler/rustc_const_eval/src/const_eval/machine.rs +++ b/compiler/rustc_const_eval/src/const_eval/machine.rs @@ -169,13 +169,15 @@ pub type CompileTimeInterpCx<'tcx> = InterpCx<'tcx, CompileTimeMachine<'tcx>>; #[derive(Debug, PartialEq, Eq, Copy, Clone)] pub enum MemoryKind { - Heap, + Heap { 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 +186,7 @@ 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, } } } @@ -420,7 +422,7 @@ 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 +455,17 @@ 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 49cd7138748..b6a64035261 100644 --- a/compiler/rustc_const_eval/src/errors.rs +++ b/compiler/rustc_const_eval/src/errors.rs @@ -44,6 +44,14 @@ pub(crate) struct MutablePtrInFinal { } #[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 { pub gate: String, diff --git a/compiler/rustc_const_eval/src/interpret/intern.rs b/compiler/rustc_const_eval/src/interpret/intern.rs index f0f958d069e..85524949053 100644 --- a/compiler/rustc_const_eval/src/interpret/intern.rs +++ b/compiler/rustc_const_eval/src/interpret/intern.rs @@ -31,7 +31,7 @@ use super::{ }; use crate::const_eval; use crate::const_eval::DummyMachine; -use crate::errors::NestedStaticInThreadLocal; +use crate::errors::{ConstHeapPtrInFinal, NestedStaticInThreadLocal}; pub trait CompileTimeMachine<'tcx, T> = Machine< 'tcx, @@ -55,6 +55,35 @@ impl HasStaticRootDefId for const_eval::CompileTimeMachine<'_> { } } +pub enum DisallowInternReason { + ConstHeap, +} + +/// A trait for controlling whether memory allocated in the interpreter can be interned. +/// +/// This prevents us from interning `const_allocate` pointers that have not been made +/// global through `const_make_global`. +pub trait CanIntern { + fn disallows_intern(&self) -> Option<DisallowInternReason>; +} + +impl CanIntern for const_eval::MemoryKind { + fn disallows_intern(&self) -> Option<DisallowInternReason> { + match self { + const_eval::MemoryKind::Heap { was_made_global: false } => { + Some(DisallowInternReason::ConstHeap) + } + const_eval::MemoryKind::Heap { was_made_global: true } => None, + } + } +} + +impl CanIntern for ! { + fn disallows_intern(&self) -> Option<DisallowInternReason> { + *self + } +} + /// Intern an allocation. Returns `Err` if the allocation does not exist in the local memory. /// /// `mutability` can be used to force immutable interning: if it is `Mutability::Not`, the @@ -62,7 +91,7 @@ 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, T: CanIntern, M: CompileTimeMachine<'tcx, T>>( ecx: &mut InterpCx<'tcx, M>, alloc_id: AllocId, mutability: Mutability, @@ -71,9 +100,26 @@ fn intern_shallow<'tcx, T, M: CompileTimeMachine<'tcx, T>>( 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 { + let Some((kind, mut alloc)) = ecx.memory.alloc_map.swap_remove(&alloc_id) else { return Err(()); }; + + match kind { + MemoryKind::Machine(x) if let Some(reason) = x.disallows_intern() => match reason { + // attempting to intern a `const_allocate`d pointer that was not made global via + // `const_make_global`. We emit an error here but don't return an `Err`. The `Err` + // is for pointers that we can't intern at all (i.e. dangling pointers). We still + // (recursively) intern this pointer because we don't have to worry about the + // additional paperwork involved with _not_ interning it, such as storing it in + // the dead memory map and having to deal with additional "dangling pointer" + // messages if someone tries to store the non-made-global ptr in the final value. + DisallowInternReason::ConstHeap => { + ecx.tcx.dcx().emit_err(ConstHeapPtrInFinal { span: ecx.tcx.span }); + } + }, + MemoryKind::Machine(_) | 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 +145,7 @@ 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` @@ -181,7 +227,7 @@ 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 { @@ -321,7 +367,7 @@ pub fn intern_const_alloc_recursive<'tcx, M: CompileTimeMachine<'tcx, const_eval /// 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, T: CanIntern, M: CompileTimeMachine<'tcx, T>>( ecx: &mut InterpCx<'tcx, M>, alloc_id: AllocId, ) -> InterpResult<'tcx, ()> { diff --git a/compiler/rustc_const_eval/src/interpret/memory.rs b/compiler/rustc_const_eval/src/interpret/memory.rs index 6414821e21d..50578e13a7a 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 +312,49 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> { interp_ok(new_ptr) } + /// mark the `const_allocate`d pointer immutable so we can intern it. + pub fn make_const_heap_ptr_global( + &mut self, + ptr: Pointer<Option<M::Provenance>>, + ) -> InterpResult<'tcx> + where + M: Machine<'tcx, MemoryKind = crate::const_eval::MemoryKind>, + { + let (alloc_id, offset, _) = self.ptr_get_alloc_id(ptr, 0)?; + if offset.bytes() != 0 { + return Err(ConstEvalErrKind::ConstMakeGlobalWithOffset(format!("{ptr:?}"))).into(); + } + + let not_local_heap = + matches!(self.tcx.try_get_global_alloc(alloc_id), Some(GlobalAlloc::Memory(_))); + + if not_local_heap { + return Err(ConstEvalErrKind::ConstMakeGlobalPtrIsNonHeap(format!("{ptr:?}"))).into(); + } + + let (kind, alloc) = self.memory.alloc_map.get_mut_or(alloc_id, || { + Err(ConstEvalErrKind::ConstMakeGlobalWithDanglingPtr(format!("{ptr:?}"))) + })?; + + alloc.mutability = Mutability::Not; + + match kind { + MemoryKind::Stack | MemoryKind::CallerLocation => { + return Err(ConstEvalErrKind::ConstMakeGlobalPtrIsNonHeap(format!("{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; + } + } + + interp_ok(()) + } + #[instrument(skip(self), level = "debug")] pub fn deallocate_ptr( &mut self, 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 4ca39bbc68e..1c2167a50fd 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 +52,8 @@ 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"); + let allocated = + cx.allocate(ty, MemoryKind::Stack).expect("OOM: failed to allocate for uninit check"); if kind == ValidityRequirement::Zero { cx.write_bytes_ptr( @@ -185,7 +184,10 @@ pub(crate) fn validate_scalar_in_layout<'tcx>( bug!("could not compute layout of {scalar:?}:{ty:?}") }; let allocated = cx - .allocate(layout, MemoryKind::Machine(crate::const_eval::MemoryKind::Heap)) + .allocate( + layout, + MemoryKind::Machine(crate::const_eval::MemoryKind::Heap { was_made_global: false }), + ) .expect("OOM: failed to allocate for uninit check"); cx.write_scalar(scalar, &allocated).unwrap(); |