1 //! Global machine state as well as implementation of the interpreter engine
5 use std::cell::RefCell;
8 use rand::rngs::StdRng;
11 use rustc_ast::ast::Mutability;
12 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
14 use rustc_data_structures::static_assert_size;
19 layout::{LayoutCx, LayoutError, LayoutOf, TyAndLayout},
20 Instance, Ty, TyCtxt, TypeAndMut,
23 use rustc_span::def_id::{CrateNum, DefId};
24 use rustc_span::Symbol;
25 use rustc_target::abi::Size;
26 use rustc_target::spec::abi::Abi;
29 concurrency::{data_race, weak_memory},
30 shims::unix::FileHandler,
34 // Some global facts about the emulated machine.
35 pub const PAGE_SIZE: u64 = 4 * 1024; // FIXME: adjust to target architecture
36 pub const STACK_ADDR: u64 = 32 * PAGE_SIZE; // not really about the "stack", but where we start assigning integer addresses to allocations
37 pub const STACK_SIZE: u64 = 16 * PAGE_SIZE; // whatever
39 /// Extra data stored with each stack frame
40 pub struct FrameData<'tcx> {
41 /// Extra data for Stacked Borrows.
42 pub stacked_borrows: Option<stacked_borrows::FrameExtra>,
44 /// If this is Some(), then this is a special "catch unwind" frame (the frame of `try_fn`
45 /// called by `try`). When this frame is popped during unwinding a panic,
46 /// we stop unwinding, use the `CatchUnwindData` to handle catching.
47 pub catch_unwind: Option<CatchUnwindData<'tcx>>,
49 /// If `measureme` profiling is enabled, holds timing information
50 /// for the start of this frame. When we finish executing this frame,
51 /// we use this to register a completed event with `measureme`.
52 pub timing: Option<measureme::DetachedTiming>,
55 impl<'tcx> std::fmt::Debug for FrameData<'tcx> {
56 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
57 // Omitting `timing`, it does not support `Debug`.
58 let FrameData { stacked_borrows, catch_unwind, timing: _ } = self;
59 f.debug_struct("FrameData")
60 .field("stacked_borrows", stacked_borrows)
61 .field("catch_unwind", catch_unwind)
66 impl VisitTags for FrameData<'_> {
67 fn visit_tags(&self, visit: &mut dyn FnMut(SbTag)) {
68 let FrameData { catch_unwind, stacked_borrows, timing: _ } = self;
70 catch_unwind.visit_tags(visit);
71 stacked_borrows.visit_tags(visit);
75 /// Extra memory kinds
76 #[derive(Debug, Copy, Clone, PartialEq, Eq)]
77 pub enum MiriMemoryKind {
78 /// `__rust_alloc` memory.
82 /// Windows `HeapAlloc` memory.
84 /// Memory for args, errno, and other parts of the machine-managed environment.
85 /// This memory may leak.
87 /// Memory allocated by the runtime (e.g. env vars). Separate from `Machine`
88 /// because we clean it up and leak-check it.
90 /// Globals copied from `tcx`.
91 /// This memory may leak.
93 /// Memory for extern statics.
94 /// This memory may leak.
96 /// Memory for thread-local statics.
97 /// This memory may leak.
101 impl From<MiriMemoryKind> for MemoryKind<MiriMemoryKind> {
103 fn from(kind: MiriMemoryKind) -> MemoryKind<MiriMemoryKind> {
104 MemoryKind::Machine(kind)
108 impl MayLeak for MiriMemoryKind {
110 fn may_leak(self) -> bool {
111 use self::MiriMemoryKind::*;
113 Rust | C | WinHeap | Runtime => false,
114 Machine | Global | ExternStatic | Tls => true,
119 impl fmt::Display for MiriMemoryKind {
120 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
121 use self::MiriMemoryKind::*;
123 Rust => write!(f, "Rust heap"),
124 C => write!(f, "C heap"),
125 WinHeap => write!(f, "Windows heap"),
126 Machine => write!(f, "machine-managed memory"),
127 Runtime => write!(f, "language runtime memory"),
128 Global => write!(f, "global (static or const)"),
129 ExternStatic => write!(f, "extern static"),
130 Tls => write!(f, "thread-local static"),
135 /// Pointer provenance.
136 #[derive(Debug, Clone, Copy)]
137 pub enum Provenance {
140 /// Stacked Borrows tag.
146 // This needs to be `Eq`+`Hash` because the `Machine` trait needs that because validity checking
147 // *might* be recursive and then it has to track which places have already been visited.
148 // However, comparing provenance is meaningless, since `Wildcard` might be any provenance -- and of
149 // course we don't actually do recursive checking.
150 // We could change `RefTracking` to strip provenance for its `seen` set but that type is generic so that is quite annoying.
151 // Instead owe add the required instances but make them panic.
152 impl PartialEq for Provenance {
153 fn eq(&self, _other: &Self) -> bool {
154 panic!("Provenance must not be compared")
157 impl Eq for Provenance {}
158 impl std::hash::Hash for Provenance {
159 fn hash<H: std::hash::Hasher>(&self, _state: &mut H) {
160 panic!("Provenance must not be hashed")
164 /// The "extra" information a pointer has over a regular AllocId.
165 #[derive(Copy, Clone, PartialEq)]
166 pub enum ProvenanceExtra {
171 #[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
172 static_assert_size!(Pointer<Provenance>, 24);
173 // FIXME: this would with in 24bytes but layout optimizations are not smart enough
174 // #[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
175 //static_assert_size!(Pointer<Option<Provenance>>, 24);
176 #[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
177 static_assert_size!(Scalar<Provenance>, 32);
179 impl interpret::Provenance for Provenance {
180 /// We use absolute addresses in the `offset` of a `Pointer<Provenance>`.
181 const OFFSET_IS_ADDR: bool = true;
183 /// We cannot err on partial overwrites, it happens too often in practice (due to unions).
184 const ERR_ON_PARTIAL_PTR_OVERWRITE: bool = false;
186 fn fmt(ptr: &Pointer<Self>, f: &mut fmt::Formatter<'_>) -> fmt::Result {
187 let (prov, addr) = ptr.into_parts(); // address is absolute
188 write!(f, "{:#x}", addr.bytes())?;
191 Provenance::Concrete { alloc_id, sb } => {
192 // Forward `alternate` flag to `alloc_id` printing.
194 write!(f, "[{:#?}]", alloc_id)?;
196 write!(f, "[{:?}]", alloc_id)?;
198 // Print Stacked Borrows tag.
199 write!(f, "{:?}", sb)?;
201 Provenance::Wildcard => {
202 write!(f, "[wildcard]")?;
209 fn get_alloc_id(self) -> Option<AllocId> {
211 Provenance::Concrete { alloc_id, .. } => Some(alloc_id),
212 Provenance::Wildcard => None,
216 fn join(left: Option<Self>, right: Option<Self>) -> Option<Self> {
217 match (left, right) {
218 // If both are the *same* concrete tag, that is the result.
220 Some(Provenance::Concrete { alloc_id: left_alloc, sb: left_sb }),
221 Some(Provenance::Concrete { alloc_id: right_alloc, sb: right_sb }),
222 ) if left_alloc == right_alloc && left_sb == right_sb => left,
223 // If one side is a wildcard, the best possible outcome is that it is equal to the other
224 // one, and we use that.
225 (Some(Provenance::Wildcard), o) | (o, Some(Provenance::Wildcard)) => o,
226 // Otherwise, fall back to `None`.
232 impl fmt::Debug for ProvenanceExtra {
233 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
235 ProvenanceExtra::Concrete(pid) => write!(f, "{pid:?}"),
236 ProvenanceExtra::Wildcard => write!(f, "<wildcard>"),
241 impl ProvenanceExtra {
242 pub fn and_then<T>(self, f: impl FnOnce(SbTag) -> Option<T>) -> Option<T> {
244 ProvenanceExtra::Concrete(pid) => f(pid),
245 ProvenanceExtra::Wildcard => None,
250 /// Extra per-allocation data
251 #[derive(Debug, Clone)]
252 pub struct AllocExtra {
253 /// Stacked Borrows state is only added if it is enabled.
254 pub stacked_borrows: Option<stacked_borrows::AllocExtra>,
255 /// Data race detection via the use of a vector-clock,
256 /// this is only added if it is enabled.
257 pub data_race: Option<data_race::AllocExtra>,
258 /// Weak memory emulation via the use of store buffers,
259 /// this is only added if it is enabled.
260 pub weak_memory: Option<weak_memory::AllocExtra>,
263 impl VisitTags for AllocExtra {
264 fn visit_tags(&self, visit: &mut dyn FnMut(SbTag)) {
265 let AllocExtra { stacked_borrows, data_race, weak_memory } = self;
267 stacked_borrows.visit_tags(visit);
268 data_race.visit_tags(visit);
269 weak_memory.visit_tags(visit);
273 /// Precomputed layouts of primitive types
274 pub struct PrimitiveLayouts<'tcx> {
275 pub unit: TyAndLayout<'tcx>,
276 pub i8: TyAndLayout<'tcx>,
277 pub i16: TyAndLayout<'tcx>,
278 pub i32: TyAndLayout<'tcx>,
279 pub isize: TyAndLayout<'tcx>,
280 pub u8: TyAndLayout<'tcx>,
281 pub u16: TyAndLayout<'tcx>,
282 pub u32: TyAndLayout<'tcx>,
283 pub usize: TyAndLayout<'tcx>,
284 pub bool: TyAndLayout<'tcx>,
285 pub mut_raw_ptr: TyAndLayout<'tcx>, // *mut ()
286 pub const_raw_ptr: TyAndLayout<'tcx>, // *const ()
289 impl<'mir, 'tcx: 'mir> PrimitiveLayouts<'tcx> {
290 fn new(layout_cx: LayoutCx<'tcx, TyCtxt<'tcx>>) -> Result<Self, LayoutError<'tcx>> {
291 let tcx = layout_cx.tcx;
292 let mut_raw_ptr = tcx.mk_ptr(TypeAndMut { ty: tcx.types.unit, mutbl: Mutability::Mut });
293 let const_raw_ptr = tcx.mk_ptr(TypeAndMut { ty: tcx.types.unit, mutbl: Mutability::Not });
295 unit: layout_cx.layout_of(tcx.mk_unit())?,
296 i8: layout_cx.layout_of(tcx.types.i8)?,
297 i16: layout_cx.layout_of(tcx.types.i16)?,
298 i32: layout_cx.layout_of(tcx.types.i32)?,
299 isize: layout_cx.layout_of(tcx.types.isize)?,
300 u8: layout_cx.layout_of(tcx.types.u8)?,
301 u16: layout_cx.layout_of(tcx.types.u16)?,
302 u32: layout_cx.layout_of(tcx.types.u32)?,
303 usize: layout_cx.layout_of(tcx.types.usize)?,
304 bool: layout_cx.layout_of(tcx.types.bool)?,
305 mut_raw_ptr: layout_cx.layout_of(mut_raw_ptr)?,
306 const_raw_ptr: layout_cx.layout_of(const_raw_ptr)?,
311 /// The machine itself.
313 /// If you add anything here that stores machine values, remember to update
314 /// `visit_all_machine_values`!
315 pub struct MiriMachine<'mir, 'tcx> {
316 // We carry a copy of the global `TyCtxt` for convenience, so methods taking just `&Evaluator` have `tcx` access.
317 pub tcx: TyCtxt<'tcx>,
319 /// Stacked Borrows global data.
320 pub stacked_borrows: Option<stacked_borrows::GlobalState>,
322 /// Data race detector global data.
323 pub data_race: Option<data_race::GlobalState>,
325 /// Ptr-int-cast module global data.
326 pub intptrcast: intptrcast::GlobalState,
328 /// Environment variables set by `setenv`.
329 /// Miri does not expose env vars from the host to the emulated program.
330 pub(crate) env_vars: EnvVars<'tcx>,
332 /// Program arguments (`Option` because we can only initialize them after creating the ecx).
333 /// These are *pointers* to argc/argv because macOS.
334 /// We also need the full command line as one string because of Windows.
335 pub(crate) argc: Option<MemPlace<Provenance>>,
336 pub(crate) argv: Option<MemPlace<Provenance>>,
337 pub(crate) cmd_line: Option<MemPlace<Provenance>>,
340 pub(crate) tls: TlsData<'tcx>,
342 /// What should Miri do when an op requires communicating with the host,
343 /// such as accessing host env vars, random number generation, and
344 /// file system access.
345 pub(crate) isolated_op: IsolatedOp,
347 /// Whether to enforce the validity invariant.
348 pub(crate) validate: bool,
350 /// Whether to enforce [ABI](Abi) of function calls.
351 pub(crate) enforce_abi: bool,
353 /// The table of file descriptors.
354 pub(crate) file_handler: shims::unix::FileHandler,
355 /// The table of directory descriptors.
356 pub(crate) dir_handler: shims::unix::DirHandler,
358 /// This machine's monotone clock.
359 pub(crate) clock: Clock,
361 /// The set of threads.
362 pub(crate) threads: ThreadManager<'mir, 'tcx>,
364 /// Precomputed `TyLayout`s for primitive data types that are commonly used inside Miri.
365 pub(crate) layouts: PrimitiveLayouts<'tcx>,
367 /// Allocations that are considered roots of static memory (that may leak).
368 pub(crate) static_roots: Vec<AllocId>,
370 /// The `measureme` profiler used to record timing information about
371 /// the emulated program.
372 profiler: Option<measureme::Profiler>,
373 /// Used with `profiler` to cache the `StringId`s for event names
374 /// uesd with `measureme`.
375 string_cache: FxHashMap<String, measureme::StringId>,
377 /// Cache of `Instance` exported under the given `Symbol` name.
378 /// `None` means no `Instance` exported under the given name is found.
379 pub(crate) exported_symbols_cache: FxHashMap<Symbol, Option<Instance<'tcx>>>,
381 /// Whether to raise a panic in the context of the evaluated process when unsupported
382 /// functionality is encountered. If `false`, an error is propagated in the Miri application context
383 /// instead (default behavior)
384 pub(crate) panic_on_unsupported: bool,
386 /// Equivalent setting as RUST_BACKTRACE on encountering an error.
387 pub(crate) backtrace_style: BacktraceStyle,
389 /// Crates which are considered local for the purposes of error reporting.
390 pub(crate) local_crates: Vec<CrateNum>,
392 /// Mapping extern static names to their base pointer.
393 extern_statics: FxHashMap<Symbol, Pointer<Provenance>>,
395 /// The random number generator used for resolving non-determinism.
396 /// Needs to be queried by ptr_to_int, hence needs interior mutability.
397 pub(crate) rng: RefCell<StdRng>,
399 /// The allocation IDs to report when they are being allocated
400 /// (helps for debugging memory leaks and use after free bugs).
401 tracked_alloc_ids: FxHashSet<AllocId>,
403 /// Controls whether alignment of memory accesses is being checked.
404 pub(crate) check_alignment: AlignmentCheck,
406 /// Failure rate of compare_exchange_weak, between 0.0 and 1.0
407 pub(crate) cmpxchg_weak_failure_rate: f64,
409 /// Corresponds to -Zmiri-mute-stdout-stderr and doesn't write the output but acts as if it succeeded.
410 pub(crate) mute_stdout_stderr: bool,
412 /// Whether weak memory emulation is enabled
413 pub(crate) weak_memory: bool,
415 /// The probability of the active thread being preempted at the end of each basic block.
416 pub(crate) preemption_rate: f64,
418 /// If `Some`, we will report the current stack every N basic blocks.
419 pub(crate) report_progress: Option<u32>,
420 // The total number of blocks that have been executed.
421 pub(crate) basic_block_count: u64,
423 /// Handle of the optional shared object file for external functions.
425 pub external_so_lib: Option<(libloading::Library, std::path::PathBuf)>,
427 /// Run a garbage collector for SbTags every N basic blocks.
428 pub(crate) gc_interval: u32,
429 /// The number of blocks that passed since the last SbTag GC pass.
430 pub(crate) since_gc: u32,
431 /// The number of CPUs to be reported by miri.
432 pub(crate) num_cpus: u32,
435 impl<'mir, 'tcx> MiriMachine<'mir, 'tcx> {
436 pub(crate) fn new(config: &MiriConfig, layout_cx: LayoutCx<'tcx, TyCtxt<'tcx>>) -> Self {
437 let local_crates = helpers::get_local_crates(layout_cx.tcx);
439 PrimitiveLayouts::new(layout_cx).expect("Couldn't get layouts of primitive types");
440 let profiler = config.measureme_out.as_ref().map(|out| {
441 measureme::Profiler::new(out).expect("Couldn't create `measureme` profiler")
443 let rng = StdRng::seed_from_u64(config.seed.unwrap_or(0));
444 let stacked_borrows = config.stacked_borrows.then(|| {
445 RefCell::new(stacked_borrows::GlobalStateInner::new(
446 config.tracked_pointer_tags.clone(),
447 config.tracked_call_ids.clone(),
451 let data_race = config.data_race_detector.then(|| data_race::GlobalState::new(config));
456 intptrcast: RefCell::new(intptrcast::GlobalStateInner::new(config)),
457 // `env_vars` depends on a full interpreter so we cannot properly initialize it yet.
458 env_vars: EnvVars::default(),
462 tls: TlsData::default(),
463 isolated_op: config.isolated_op,
464 validate: config.validate,
465 enforce_abi: config.check_abi,
466 file_handler: FileHandler::new(config.mute_stdout_stderr),
467 dir_handler: Default::default(),
469 threads: ThreadManager::default(),
470 static_roots: Vec::new(),
472 string_cache: Default::default(),
473 exported_symbols_cache: FxHashMap::default(),
474 panic_on_unsupported: config.panic_on_unsupported,
475 backtrace_style: config.backtrace_style,
477 extern_statics: FxHashMap::default(),
478 rng: RefCell::new(rng),
479 tracked_alloc_ids: config.tracked_alloc_ids.clone(),
480 check_alignment: config.check_alignment,
481 cmpxchg_weak_failure_rate: config.cmpxchg_weak_failure_rate,
482 mute_stdout_stderr: config.mute_stdout_stderr,
483 weak_memory: config.weak_memory_emulation,
484 preemption_rate: config.preemption_rate,
485 report_progress: config.report_progress,
486 basic_block_count: 0,
487 clock: Clock::new(config.isolated_op == IsolatedOp::Allow),
489 external_so_lib: config.external_so_file.as_ref().map(|lib_file_path| {
490 let target_triple = layout_cx.tcx.sess.opts.target_triple.triple();
491 // Check if host target == the session target.
492 if env!("TARGET") != target_triple {
494 "calling external C functions in linked .so file requires host and target to be the same: host={}, target={}",
499 // Note: it is the user's responsibility to provide a correct SO file.
500 // WATCH OUT: If an invalid/incorrect SO file is specified, this can cause
501 // undefined behaviour in Miri itself!
504 libloading::Library::new(lib_file_path)
505 .expect("failed to read specified extern shared object file")
507 lib_file_path.clone(),
510 gc_interval: config.gc_interval,
512 num_cpus: config.num_cpus,
516 pub(crate) fn late_init(
517 this: &mut MiriInterpCx<'mir, 'tcx>,
519 ) -> InterpResult<'tcx> {
520 EnvVars::init(this, config)?;
521 MiriMachine::init_extern_statics(this)?;
522 ThreadManager::init(this);
526 fn add_extern_static(
527 this: &mut MiriInterpCx<'mir, 'tcx>,
529 ptr: Pointer<Option<Provenance>>,
531 // This got just allocated, so there definitely is a pointer here.
532 let ptr = ptr.into_pointer_or_addr().unwrap();
533 this.machine.extern_statics.try_insert(Symbol::intern(name), ptr).unwrap();
536 fn alloc_extern_static(
537 this: &mut MiriInterpCx<'mir, 'tcx>,
539 val: ImmTy<'tcx, Provenance>,
540 ) -> InterpResult<'tcx> {
541 let place = this.allocate(val.layout, MiriMemoryKind::ExternStatic.into())?;
542 this.write_immediate(*val, &place.into())?;
543 Self::add_extern_static(this, name, place.ptr);
547 /// Sets up the "extern statics" for this machine.
548 fn init_extern_statics(this: &mut MiriInterpCx<'mir, 'tcx>) -> InterpResult<'tcx> {
549 match this.tcx.sess.target.os.as_ref() {
552 Self::add_extern_static(
555 this.machine.env_vars.environ.unwrap().ptr,
557 // A couple zero-initialized pointer-sized extern statics.
558 // Most of them are for weak symbols, which we all set to null (indicating that the
559 // symbol is not supported, and triggering fallback code which ends up calling a
560 // syscall that we do support).
561 for name in &["__cxa_thread_atexit_impl", "getrandom", "statx", "__clock_gettime64"]
563 let val = ImmTy::from_int(0, this.machine.layouts.usize);
564 Self::alloc_extern_static(this, name, val)?;
569 Self::add_extern_static(
572 this.machine.env_vars.environ.unwrap().ptr,
577 let layout = this.machine.layouts.const_raw_ptr;
578 let dlsym = Dlsym::from_str("signal".as_bytes(), &this.tcx.sess.target.os)?
579 .expect("`signal` must be an actual dlsym on android");
580 let ptr = this.create_fn_alloc_ptr(FnVal::Other(dlsym));
581 let val = ImmTy::from_scalar(Scalar::from_pointer(ptr, this), layout);
582 Self::alloc_extern_static(this, "signal", val)?;
583 // A couple zero-initialized pointer-sized extern statics.
584 // Most of them are for weak symbols, which we all set to null (indicating that the
585 // symbol is not supported, and triggering fallback code.)
586 for name in &["bsd_signal"] {
587 let val = ImmTy::from_int(0, this.machine.layouts.usize);
588 Self::alloc_extern_static(this, name, val)?;
593 // This is some obscure hack that is part of the Windows TLS story. It's a `u8`.
594 let val = ImmTy::from_int(0, this.machine.layouts.u8);
595 Self::alloc_extern_static(this, "_tls_used", val)?;
597 _ => {} // No "extern statics" supported on this target
602 pub(crate) fn communicate(&self) -> bool {
603 self.isolated_op == IsolatedOp::Allow
606 /// Check whether the stack frame that this `FrameInfo` refers to is part of a local crate.
607 pub(crate) fn is_local(&self, frame: &FrameInfo<'_>) -> bool {
608 let def_id = frame.instance.def_id();
609 def_id.is_local() || self.local_crates.contains(&def_id.krate)
613 impl VisitTags for MiriMachine<'_, '_> {
614 fn visit_tags(&self, visit: &mut dyn FnMut(SbTag)) {
638 exported_symbols_cache: _,
639 panic_on_unsupported: _,
643 tracked_alloc_ids: _,
645 cmpxchg_weak_failure_rate: _,
646 mute_stdout_stderr: _,
650 basic_block_count: _,
658 threads.visit_tags(visit);
659 tls.visit_tags(visit);
660 env_vars.visit_tags(visit);
661 dir_handler.visit_tags(visit);
662 file_handler.visit_tags(visit);
663 data_race.visit_tags(visit);
664 stacked_borrows.visit_tags(visit);
665 intptrcast.visit_tags(visit);
666 argc.visit_tags(visit);
667 argv.visit_tags(visit);
668 cmd_line.visit_tags(visit);
669 for ptr in extern_statics.values() {
670 ptr.visit_tags(visit);
675 /// A rustc InterpCx for Miri.
676 pub type MiriInterpCx<'mir, 'tcx> = InterpCx<'mir, 'tcx, MiriMachine<'mir, 'tcx>>;
678 /// A little trait that's useful to be inherited by extension traits.
679 pub trait MiriInterpCxExt<'mir, 'tcx> {
680 fn eval_context_ref<'a>(&'a self) -> &'a MiriInterpCx<'mir, 'tcx>;
681 fn eval_context_mut<'a>(&'a mut self) -> &'a mut MiriInterpCx<'mir, 'tcx>;
683 impl<'mir, 'tcx> MiriInterpCxExt<'mir, 'tcx> for MiriInterpCx<'mir, 'tcx> {
685 fn eval_context_ref(&self) -> &MiriInterpCx<'mir, 'tcx> {
689 fn eval_context_mut(&mut self) -> &mut MiriInterpCx<'mir, 'tcx> {
694 /// Machine hook implementations.
695 impl<'mir, 'tcx> Machine<'mir, 'tcx> for MiriMachine<'mir, 'tcx> {
696 type MemoryKind = MiriMemoryKind;
697 type ExtraFnVal = Dlsym;
699 type FrameExtra = FrameData<'tcx>;
700 type AllocExtra = AllocExtra;
702 type Provenance = Provenance;
703 type ProvenanceExtra = ProvenanceExtra;
705 type MemoryMap = MonoHashMap<
707 (MemoryKind<MiriMemoryKind>, Allocation<Provenance, Self::AllocExtra>),
710 const GLOBAL_KIND: Option<MiriMemoryKind> = Some(MiriMemoryKind::Global);
712 const PANIC_ON_ALLOC_FAIL: bool = false;
715 fn enforce_alignment(ecx: &MiriInterpCx<'mir, 'tcx>) -> bool {
716 ecx.machine.check_alignment != AlignmentCheck::None
720 fn use_addr_for_alignment_check(ecx: &MiriInterpCx<'mir, 'tcx>) -> bool {
721 ecx.machine.check_alignment == AlignmentCheck::Int
725 fn enforce_validity(ecx: &MiriInterpCx<'mir, 'tcx>) -> bool {
730 fn enforce_abi(ecx: &MiriInterpCx<'mir, 'tcx>) -> bool {
731 ecx.machine.enforce_abi
735 fn checked_binop_checks_overflow(ecx: &MiriInterpCx<'mir, 'tcx>) -> bool {
736 ecx.tcx.sess.overflow_checks()
740 fn find_mir_or_eval_fn(
741 ecx: &mut MiriInterpCx<'mir, 'tcx>,
742 instance: ty::Instance<'tcx>,
744 args: &[OpTy<'tcx, Provenance>],
745 dest: &PlaceTy<'tcx, Provenance>,
746 ret: Option<mir::BasicBlock>,
747 unwind: StackPopUnwind,
748 ) -> InterpResult<'tcx, Option<(&'mir mir::Body<'tcx>, ty::Instance<'tcx>)>> {
749 ecx.find_mir_or_eval_fn(instance, abi, args, dest, ret, unwind)
754 ecx: &mut MiriInterpCx<'mir, 'tcx>,
757 args: &[OpTy<'tcx, Provenance>],
758 dest: &PlaceTy<'tcx, Provenance>,
759 ret: Option<mir::BasicBlock>,
760 _unwind: StackPopUnwind,
761 ) -> InterpResult<'tcx> {
762 ecx.call_dlsym(fn_val, abi, args, dest, ret)
767 ecx: &mut MiriInterpCx<'mir, 'tcx>,
768 instance: ty::Instance<'tcx>,
769 args: &[OpTy<'tcx, Provenance>],
770 dest: &PlaceTy<'tcx, Provenance>,
771 ret: Option<mir::BasicBlock>,
772 unwind: StackPopUnwind,
773 ) -> InterpResult<'tcx> {
774 ecx.call_intrinsic(instance, args, dest, ret, unwind)
779 ecx: &mut MiriInterpCx<'mir, 'tcx>,
780 msg: &mir::AssertMessage<'tcx>,
781 unwind: Option<mir::BasicBlock>,
782 ) -> InterpResult<'tcx> {
783 ecx.assert_panic(msg, unwind)
787 fn abort(_ecx: &mut MiriInterpCx<'mir, 'tcx>, msg: String) -> InterpResult<'tcx, !> {
788 throw_machine_stop!(TerminationInfo::Abort(msg))
793 ecx: &MiriInterpCx<'mir, 'tcx>,
795 left: &ImmTy<'tcx, Provenance>,
796 right: &ImmTy<'tcx, Provenance>,
797 ) -> InterpResult<'tcx, (Scalar<Provenance>, bool, Ty<'tcx>)> {
798 ecx.binary_ptr_op(bin_op, left, right)
801 fn thread_local_static_base_pointer(
802 ecx: &mut MiriInterpCx<'mir, 'tcx>,
804 ) -> InterpResult<'tcx, Pointer<Provenance>> {
805 ecx.get_or_create_thread_local_alloc(def_id)
808 fn extern_static_base_pointer(
809 ecx: &MiriInterpCx<'mir, 'tcx>,
811 ) -> InterpResult<'tcx, Pointer<Provenance>> {
812 let link_name = ecx.item_link_name(def_id);
813 if let Some(&ptr) = ecx.machine.extern_statics.get(&link_name) {
814 // Various parts of the engine rely on `get_alloc_info` for size and alignment
815 // information. That uses the type information of this static.
816 // Make sure it matches the Miri allocation for this.
817 let Provenance::Concrete { alloc_id, .. } = ptr.provenance else {
818 panic!("extern_statics cannot contain wildcards")
820 let (shim_size, shim_align, _kind) = ecx.get_alloc_info(alloc_id);
821 let extern_decl_layout =
822 ecx.tcx.layout_of(ty::ParamEnv::empty().and(ecx.tcx.type_of(def_id))).unwrap();
823 if extern_decl_layout.size != shim_size || extern_decl_layout.align.abi != shim_align {
825 "`extern` static `{name}` from crate `{krate}` has been declared \
826 with a size of {decl_size} bytes and alignment of {decl_align} bytes, \
827 but Miri emulates it via an extern static shim \
828 with a size of {shim_size} bytes and alignment of {shim_align} bytes",
829 name = ecx.tcx.def_path_str(def_id),
830 krate = ecx.tcx.crate_name(def_id.krate),
831 decl_size = extern_decl_layout.size.bytes(),
832 decl_align = extern_decl_layout.align.abi.bytes(),
833 shim_size = shim_size.bytes(),
834 shim_align = shim_align.bytes(),
840 "`extern` static `{name}` from crate `{krate}` is not supported by Miri",
841 name = ecx.tcx.def_path_str(def_id),
842 krate = ecx.tcx.crate_name(def_id.krate),
847 fn adjust_allocation<'b>(
848 ecx: &MiriInterpCx<'mir, 'tcx>,
850 alloc: Cow<'b, Allocation>,
851 kind: Option<MemoryKind<Self::MemoryKind>>,
852 ) -> InterpResult<'tcx, Cow<'b, Allocation<Self::Provenance, Self::AllocExtra>>> {
853 let kind = kind.expect("we set our STATIC_KIND so this cannot be None");
854 if ecx.machine.tracked_alloc_ids.contains(&id) {
855 ecx.emit_diagnostic(NonHaltingDiagnostic::CreatedAlloc(
863 let alloc = alloc.into_owned();
864 let stacks = ecx.machine.stacked_borrows.as_ref().map(|stacked_borrows| {
865 Stacks::new_allocation(
870 ecx.machine.current_span(),
873 let race_alloc = ecx.machine.data_race.as_ref().map(|data_race| {
874 data_race::AllocExtra::new_allocation(
876 &ecx.machine.threads,
881 let buffer_alloc = ecx.machine.weak_memory.then(weak_memory::AllocExtra::new_allocation);
882 let alloc: Allocation<Provenance, Self::AllocExtra> = alloc.adjust_from_tcx(
885 stacked_borrows: stacks.map(RefCell::new),
886 data_race: race_alloc,
887 weak_memory: buffer_alloc,
889 |ptr| ecx.global_base_pointer(ptr),
891 Ok(Cow::Owned(alloc))
894 fn adjust_alloc_base_pointer(
895 ecx: &MiriInterpCx<'mir, 'tcx>,
896 ptr: Pointer<AllocId>,
897 ) -> Pointer<Provenance> {
898 if cfg!(debug_assertions) {
899 // The machine promises to never call us on thread-local or extern statics.
900 let alloc_id = ptr.provenance;
901 match ecx.tcx.try_get_global_alloc(alloc_id) {
902 Some(GlobalAlloc::Static(def_id)) if ecx.tcx.is_thread_local_static(def_id) => {
903 panic!("adjust_alloc_base_pointer called on thread-local static")
905 Some(GlobalAlloc::Static(def_id)) if ecx.tcx.is_foreign_item(def_id) => {
906 panic!("adjust_alloc_base_pointer called on extern static")
911 let absolute_addr = intptrcast::GlobalStateInner::rel_ptr_to_addr(ecx, ptr);
912 let sb_tag = if let Some(stacked_borrows) = &ecx.machine.stacked_borrows {
913 stacked_borrows.borrow_mut().base_ptr_tag(ptr.provenance, &ecx.machine)
915 // Value does not matter, SB is disabled
919 Provenance::Concrete { alloc_id: ptr.provenance, sb: sb_tag },
920 Size::from_bytes(absolute_addr),
925 fn ptr_from_addr_cast(
926 ecx: &MiriInterpCx<'mir, 'tcx>,
928 ) -> InterpResult<'tcx, Pointer<Option<Self::Provenance>>> {
929 intptrcast::GlobalStateInner::ptr_from_addr_cast(ecx, addr)
933 ecx: &mut InterpCx<'mir, 'tcx, Self>,
934 ptr: Pointer<Self::Provenance>,
935 ) -> InterpResult<'tcx> {
936 match ptr.provenance {
937 Provenance::Concrete { alloc_id, sb } =>
938 intptrcast::GlobalStateInner::expose_ptr(ecx, alloc_id, sb),
939 Provenance::Wildcard => {
940 // No need to do anything for wildcard pointers as
941 // their provenances have already been previously exposed.
947 /// Convert a pointer with provenance into an allocation-offset pair,
948 /// or a `None` with an absolute address if that conversion is not possible.
950 ecx: &MiriInterpCx<'mir, 'tcx>,
951 ptr: Pointer<Self::Provenance>,
952 ) -> Option<(AllocId, Size, Self::ProvenanceExtra)> {
953 let rel = intptrcast::GlobalStateInner::abs_ptr_to_rel(ecx, ptr);
955 rel.map(|(alloc_id, size)| {
956 let sb = match ptr.provenance {
957 Provenance::Concrete { sb, .. } => ProvenanceExtra::Concrete(sb),
958 Provenance::Wildcard => ProvenanceExtra::Wildcard,
965 fn before_memory_read(
968 alloc_extra: &AllocExtra,
969 (alloc_id, prov_extra): (AllocId, Self::ProvenanceExtra),
971 ) -> InterpResult<'tcx> {
972 if let Some(data_race) = &alloc_extra.data_race {
976 machine.data_race.as_ref().unwrap(),
980 if let Some(stacked_borrows) = &alloc_extra.stacked_borrows {
981 stacked_borrows.borrow_mut().before_memory_read(
985 machine.stacked_borrows.as_ref().unwrap(),
986 machine.current_span(),
990 if let Some(weak_memory) = &alloc_extra.weak_memory {
991 weak_memory.memory_accessed(range, machine.data_race.as_ref().unwrap());
997 fn before_memory_write(
1000 alloc_extra: &mut AllocExtra,
1001 (alloc_id, prov_extra): (AllocId, Self::ProvenanceExtra),
1003 ) -> InterpResult<'tcx> {
1004 if let Some(data_race) = &mut alloc_extra.data_race {
1008 machine.data_race.as_mut().unwrap(),
1012 if let Some(stacked_borrows) = &mut alloc_extra.stacked_borrows {
1013 stacked_borrows.get_mut().before_memory_write(
1017 machine.stacked_borrows.as_ref().unwrap(),
1018 machine.current_span(),
1022 if let Some(weak_memory) = &alloc_extra.weak_memory {
1023 weak_memory.memory_accessed(range, machine.data_race.as_ref().unwrap());
1029 fn before_memory_deallocation(
1032 alloc_extra: &mut AllocExtra,
1033 (alloc_id, prove_extra): (AllocId, Self::ProvenanceExtra),
1035 ) -> InterpResult<'tcx> {
1036 if machine.tracked_alloc_ids.contains(&alloc_id) {
1037 machine.emit_diagnostic(NonHaltingDiagnostic::FreedAlloc(alloc_id));
1039 if let Some(data_race) = &mut alloc_extra.data_race {
1040 data_race.deallocate(
1043 machine.data_race.as_mut().unwrap(),
1047 if let Some(stacked_borrows) = &mut alloc_extra.stacked_borrows {
1048 stacked_borrows.get_mut().before_memory_deallocation(
1052 machine.stacked_borrows.as_ref().unwrap(),
1053 machine.current_span(),
1063 ecx: &mut InterpCx<'mir, 'tcx, Self>,
1064 kind: mir::RetagKind,
1065 place: &PlaceTy<'tcx, Provenance>,
1066 ) -> InterpResult<'tcx> {
1067 if ecx.machine.stacked_borrows.is_some() { ecx.retag(kind, place) } else { Ok(()) }
1071 fn init_frame_extra(
1072 ecx: &mut InterpCx<'mir, 'tcx, Self>,
1073 frame: Frame<'mir, 'tcx, Provenance>,
1074 ) -> InterpResult<'tcx, Frame<'mir, 'tcx, Provenance, FrameData<'tcx>>> {
1075 // Start recording our event before doing anything else
1076 let timing = if let Some(profiler) = ecx.machine.profiler.as_ref() {
1077 let fn_name = frame.instance.to_string();
1078 let entry = ecx.machine.string_cache.entry(fn_name.clone());
1079 let name = entry.or_insert_with(|| profiler.alloc_string(&*fn_name));
1081 Some(profiler.start_recording_interval_event_detached(
1083 measureme::EventId::from_label(*name),
1084 ecx.get_active_thread().to_u32(),
1090 let stacked_borrows = ecx.machine.stacked_borrows.as_ref();
1092 let extra = FrameData {
1093 stacked_borrows: stacked_borrows.map(|sb| sb.borrow_mut().new_frame(&ecx.machine)),
1097 Ok(frame.with_extra(extra))
1101 ecx: &'a InterpCx<'mir, 'tcx, Self>,
1102 ) -> &'a [Frame<'mir, 'tcx, Self::Provenance, Self::FrameExtra>] {
1103 ecx.active_thread_stack()
1107 ecx: &'a mut InterpCx<'mir, 'tcx, Self>,
1108 ) -> &'a mut Vec<Frame<'mir, 'tcx, Self::Provenance, Self::FrameExtra>> {
1109 ecx.active_thread_stack_mut()
1112 fn before_terminator(ecx: &mut InterpCx<'mir, 'tcx, Self>) -> InterpResult<'tcx> {
1113 ecx.machine.basic_block_count += 1u64; // a u64 that is only incremented by 1 will "never" overflow
1114 ecx.machine.since_gc += 1;
1115 // Possibly report our progress.
1116 if let Some(report_progress) = ecx.machine.report_progress {
1117 if ecx.machine.basic_block_count % u64::from(report_progress) == 0 {
1118 ecx.emit_diagnostic(NonHaltingDiagnostic::ProgressReport {
1119 block_count: ecx.machine.basic_block_count,
1124 // Search for SbTags to find all live pointers, then remove all other tags from borrow
1126 // When debug assertions are enabled, run the GC as often as possible so that any cases
1127 // where it mistakenly removes an important tag become visible.
1128 if ecx.machine.gc_interval > 0 && ecx.machine.since_gc >= ecx.machine.gc_interval {
1129 ecx.machine.since_gc = 0;
1130 ecx.garbage_collect_tags()?;
1133 // These are our preemption points.
1134 ecx.maybe_preempt_active_thread();
1136 // Make sure some time passes.
1137 ecx.machine.clock.tick();
1143 fn after_stack_push(ecx: &mut InterpCx<'mir, 'tcx, Self>) -> InterpResult<'tcx> {
1144 if ecx.machine.stacked_borrows.is_some() { ecx.retag_return_place() } else { Ok(()) }
1149 ecx: &mut InterpCx<'mir, 'tcx, Self>,
1150 mut frame: Frame<'mir, 'tcx, Provenance, FrameData<'tcx>>,
1152 ) -> InterpResult<'tcx, StackPopJump> {
1153 let timing = frame.extra.timing.take();
1154 if let Some(stacked_borrows) = &ecx.machine.stacked_borrows {
1155 stacked_borrows.borrow_mut().end_call(&frame.extra);
1157 let res = ecx.handle_stack_pop_unwind(frame.extra, unwinding);
1158 if let Some(profiler) = ecx.machine.profiler.as_ref() {
1159 profiler.finish_recording_interval_event(timing.unwrap());