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.
80 /// `miri_alloc` memory.
84 /// Windows `HeapAlloc` memory.
86 /// Memory for args, errno, and other parts of the machine-managed environment.
87 /// This memory may leak.
89 /// Memory allocated by the runtime (e.g. env vars). Separate from `Machine`
90 /// because we clean it up and leak-check it.
92 /// Globals copied from `tcx`.
93 /// This memory may leak.
95 /// Memory for extern statics.
96 /// This memory may leak.
98 /// Memory for thread-local statics.
99 /// This memory may leak.
103 impl From<MiriMemoryKind> for MemoryKind<MiriMemoryKind> {
105 fn from(kind: MiriMemoryKind) -> MemoryKind<MiriMemoryKind> {
106 MemoryKind::Machine(kind)
110 impl MayLeak for MiriMemoryKind {
112 fn may_leak(self) -> bool {
113 use self::MiriMemoryKind::*;
115 Rust | Miri | C | WinHeap | Runtime => false,
116 Machine | Global | ExternStatic | Tls => true,
121 impl fmt::Display for MiriMemoryKind {
122 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
123 use self::MiriMemoryKind::*;
125 Rust => write!(f, "Rust heap"),
126 Miri => write!(f, "Miri bare-metal heap"),
127 C => write!(f, "C heap"),
128 WinHeap => write!(f, "Windows heap"),
129 Machine => write!(f, "machine-managed memory"),
130 Runtime => write!(f, "language runtime memory"),
131 Global => write!(f, "global (static or const)"),
132 ExternStatic => write!(f, "extern static"),
133 Tls => write!(f, "thread-local static"),
138 /// Pointer provenance.
139 #[derive(Clone, Copy)]
140 pub enum Provenance {
143 /// Stacked Borrows tag.
149 // This needs to be `Eq`+`Hash` because the `Machine` trait needs that because validity checking
150 // *might* be recursive and then it has to track which places have already been visited.
151 // However, comparing provenance is meaningless, since `Wildcard` might be any provenance -- and of
152 // course we don't actually do recursive checking.
153 // We could change `RefTracking` to strip provenance for its `seen` set but that type is generic so that is quite annoying.
154 // Instead owe add the required instances but make them panic.
155 impl PartialEq for Provenance {
156 fn eq(&self, _other: &Self) -> bool {
157 panic!("Provenance must not be compared")
160 impl Eq for Provenance {}
161 impl std::hash::Hash for Provenance {
162 fn hash<H: std::hash::Hasher>(&self, _state: &mut H) {
163 panic!("Provenance must not be hashed")
167 /// The "extra" information a pointer has over a regular AllocId.
168 #[derive(Copy, Clone, PartialEq)]
169 pub enum ProvenanceExtra {
174 #[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
175 static_assert_size!(Pointer<Provenance>, 24);
176 // FIXME: this would with in 24bytes but layout optimizations are not smart enough
177 // #[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
178 //static_assert_size!(Pointer<Option<Provenance>>, 24);
179 #[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
180 static_assert_size!(Scalar<Provenance>, 32);
182 impl fmt::Debug for Provenance {
183 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
185 Provenance::Concrete { alloc_id, sb } => {
186 // Forward `alternate` flag to `alloc_id` printing.
188 write!(f, "[{alloc_id:#?}]")?;
190 write!(f, "[{alloc_id:?}]")?;
192 // Print Stacked Borrows tag.
193 write!(f, "{sb:?}")?;
195 Provenance::Wildcard => {
196 write!(f, "[wildcard]")?;
203 impl interpret::Provenance for Provenance {
204 /// We use absolute addresses in the `offset` of a `Pointer<Provenance>`.
205 const OFFSET_IS_ADDR: bool = true;
207 fn get_alloc_id(self) -> Option<AllocId> {
209 Provenance::Concrete { alloc_id, .. } => Some(alloc_id),
210 Provenance::Wildcard => None,
214 fn join(left: Option<Self>, right: Option<Self>) -> Option<Self> {
215 match (left, right) {
216 // If both are the *same* concrete tag, that is the result.
218 Some(Provenance::Concrete { alloc_id: left_alloc, sb: left_sb }),
219 Some(Provenance::Concrete { alloc_id: right_alloc, sb: right_sb }),
220 ) if left_alloc == right_alloc && left_sb == right_sb => left,
221 // If one side is a wildcard, the best possible outcome is that it is equal to the other
222 // one, and we use that.
223 (Some(Provenance::Wildcard), o) | (o, Some(Provenance::Wildcard)) => o,
224 // Otherwise, fall back to `None`.
230 impl fmt::Debug for ProvenanceExtra {
231 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
233 ProvenanceExtra::Concrete(pid) => write!(f, "{pid:?}"),
234 ProvenanceExtra::Wildcard => write!(f, "<wildcard>"),
239 impl ProvenanceExtra {
240 pub fn and_then<T>(self, f: impl FnOnce(SbTag) -> Option<T>) -> Option<T> {
242 ProvenanceExtra::Concrete(pid) => f(pid),
243 ProvenanceExtra::Wildcard => None,
248 /// Extra per-allocation data
249 #[derive(Debug, Clone)]
250 pub struct AllocExtra {
251 /// Stacked Borrows state is only added if it is enabled.
252 pub stacked_borrows: Option<stacked_borrows::AllocExtra>,
253 /// Data race detection via the use of a vector-clock,
254 /// this is only added if it is enabled.
255 pub data_race: Option<data_race::AllocExtra>,
256 /// Weak memory emulation via the use of store buffers,
257 /// this is only added if it is enabled.
258 pub weak_memory: Option<weak_memory::AllocExtra>,
261 impl VisitTags for AllocExtra {
262 fn visit_tags(&self, visit: &mut dyn FnMut(SbTag)) {
263 let AllocExtra { stacked_borrows, data_race, weak_memory } = self;
265 stacked_borrows.visit_tags(visit);
266 data_race.visit_tags(visit);
267 weak_memory.visit_tags(visit);
271 /// Precomputed layouts of primitive types
272 pub struct PrimitiveLayouts<'tcx> {
273 pub unit: TyAndLayout<'tcx>,
274 pub i8: TyAndLayout<'tcx>,
275 pub i16: TyAndLayout<'tcx>,
276 pub i32: TyAndLayout<'tcx>,
277 pub i64: TyAndLayout<'tcx>,
278 pub i128: TyAndLayout<'tcx>,
279 pub isize: TyAndLayout<'tcx>,
280 pub u8: TyAndLayout<'tcx>,
281 pub u16: TyAndLayout<'tcx>,
282 pub u32: TyAndLayout<'tcx>,
283 pub u64: TyAndLayout<'tcx>,
284 pub u128: TyAndLayout<'tcx>,
285 pub usize: TyAndLayout<'tcx>,
286 pub bool: TyAndLayout<'tcx>,
287 pub mut_raw_ptr: TyAndLayout<'tcx>, // *mut ()
288 pub const_raw_ptr: TyAndLayout<'tcx>, // *const ()
291 impl<'mir, 'tcx: 'mir> PrimitiveLayouts<'tcx> {
292 fn new(layout_cx: LayoutCx<'tcx, TyCtxt<'tcx>>) -> Result<Self, LayoutError<'tcx>> {
293 let tcx = layout_cx.tcx;
294 let mut_raw_ptr = tcx.mk_ptr(TypeAndMut { ty: tcx.types.unit, mutbl: Mutability::Mut });
295 let const_raw_ptr = tcx.mk_ptr(TypeAndMut { ty: tcx.types.unit, mutbl: Mutability::Not });
297 unit: layout_cx.layout_of(tcx.mk_unit())?,
298 i8: layout_cx.layout_of(tcx.types.i8)?,
299 i16: layout_cx.layout_of(tcx.types.i16)?,
300 i32: layout_cx.layout_of(tcx.types.i32)?,
301 i64: layout_cx.layout_of(tcx.types.i64)?,
302 i128: layout_cx.layout_of(tcx.types.i128)?,
303 isize: layout_cx.layout_of(tcx.types.isize)?,
304 u8: layout_cx.layout_of(tcx.types.u8)?,
305 u16: layout_cx.layout_of(tcx.types.u16)?,
306 u32: layout_cx.layout_of(tcx.types.u32)?,
307 u64: layout_cx.layout_of(tcx.types.u64)?,
308 u128: layout_cx.layout_of(tcx.types.u128)?,
309 usize: layout_cx.layout_of(tcx.types.usize)?,
310 bool: layout_cx.layout_of(tcx.types.bool)?,
311 mut_raw_ptr: layout_cx.layout_of(mut_raw_ptr)?,
312 const_raw_ptr: layout_cx.layout_of(const_raw_ptr)?,
316 pub fn uint(&self, size: Size) -> Option<TyAndLayout<'tcx>> {
319 16 => Some(self.u16),
320 32 => Some(self.u32),
321 64 => Some(self.u64),
322 128 => Some(self.u128),
327 pub fn int(&self, size: Size) -> Option<TyAndLayout<'tcx>> {
330 16 => Some(self.i16),
331 32 => Some(self.i32),
332 64 => Some(self.i64),
333 128 => Some(self.i128),
339 /// The machine itself.
341 /// If you add anything here that stores machine values, remember to update
342 /// `visit_all_machine_values`!
343 pub struct MiriMachine<'mir, 'tcx> {
344 // We carry a copy of the global `TyCtxt` for convenience, so methods taking just `&Evaluator` have `tcx` access.
345 pub tcx: TyCtxt<'tcx>,
347 /// Stacked Borrows global data.
348 pub stacked_borrows: Option<stacked_borrows::GlobalState>,
350 /// Data race detector global data.
351 pub data_race: Option<data_race::GlobalState>,
353 /// Ptr-int-cast module global data.
354 pub intptrcast: intptrcast::GlobalState,
356 /// Environment variables set by `setenv`.
357 /// Miri does not expose env vars from the host to the emulated program.
358 pub(crate) env_vars: EnvVars<'tcx>,
360 /// Program arguments (`Option` because we can only initialize them after creating the ecx).
361 /// These are *pointers* to argc/argv because macOS.
362 /// We also need the full command line as one string because of Windows.
363 pub(crate) argc: Option<MemPlace<Provenance>>,
364 pub(crate) argv: Option<MemPlace<Provenance>>,
365 pub(crate) cmd_line: Option<MemPlace<Provenance>>,
368 pub(crate) tls: TlsData<'tcx>,
370 /// What should Miri do when an op requires communicating with the host,
371 /// such as accessing host env vars, random number generation, and
372 /// file system access.
373 pub(crate) isolated_op: IsolatedOp,
375 /// Whether to enforce the validity invariant.
376 pub(crate) validate: bool,
378 /// Whether to enforce [ABI](Abi) of function calls.
379 pub(crate) enforce_abi: bool,
381 /// The table of file descriptors.
382 pub(crate) file_handler: shims::unix::FileHandler,
383 /// The table of directory descriptors.
384 pub(crate) dir_handler: shims::unix::DirHandler,
386 /// This machine's monotone clock.
387 pub(crate) clock: Clock,
389 /// The set of threads.
390 pub(crate) threads: ThreadManager<'mir, 'tcx>,
392 /// Precomputed `TyLayout`s for primitive data types that are commonly used inside Miri.
393 pub(crate) layouts: PrimitiveLayouts<'tcx>,
395 /// Allocations that are considered roots of static memory (that may leak).
396 pub(crate) static_roots: Vec<AllocId>,
398 /// The `measureme` profiler used to record timing information about
399 /// the emulated program.
400 profiler: Option<measureme::Profiler>,
401 /// Used with `profiler` to cache the `StringId`s for event names
402 /// uesd with `measureme`.
403 string_cache: FxHashMap<String, measureme::StringId>,
405 /// Cache of `Instance` exported under the given `Symbol` name.
406 /// `None` means no `Instance` exported under the given name is found.
407 pub(crate) exported_symbols_cache: FxHashMap<Symbol, Option<Instance<'tcx>>>,
409 /// Whether to raise a panic in the context of the evaluated process when unsupported
410 /// functionality is encountered. If `false`, an error is propagated in the Miri application context
411 /// instead (default behavior)
412 pub(crate) panic_on_unsupported: bool,
414 /// Equivalent setting as RUST_BACKTRACE on encountering an error.
415 pub(crate) backtrace_style: BacktraceStyle,
417 /// Crates which are considered local for the purposes of error reporting.
418 pub(crate) local_crates: Vec<CrateNum>,
420 /// Mapping extern static names to their base pointer.
421 extern_statics: FxHashMap<Symbol, Pointer<Provenance>>,
423 /// The random number generator used for resolving non-determinism.
424 /// Needs to be queried by ptr_to_int, hence needs interior mutability.
425 pub(crate) rng: RefCell<StdRng>,
427 /// The allocation IDs to report when they are being allocated
428 /// (helps for debugging memory leaks and use after free bugs).
429 tracked_alloc_ids: FxHashSet<AllocId>,
431 /// Controls whether alignment of memory accesses is being checked.
432 pub(crate) check_alignment: AlignmentCheck,
434 /// Failure rate of compare_exchange_weak, between 0.0 and 1.0
435 pub(crate) cmpxchg_weak_failure_rate: f64,
437 /// Corresponds to -Zmiri-mute-stdout-stderr and doesn't write the output but acts as if it succeeded.
438 pub(crate) mute_stdout_stderr: bool,
440 /// Whether weak memory emulation is enabled
441 pub(crate) weak_memory: bool,
443 /// The probability of the active thread being preempted at the end of each basic block.
444 pub(crate) preemption_rate: f64,
446 /// If `Some`, we will report the current stack every N basic blocks.
447 pub(crate) report_progress: Option<u32>,
448 // The total number of blocks that have been executed.
449 pub(crate) basic_block_count: u64,
451 /// Handle of the optional shared object file for external functions.
452 #[cfg(target_os = "linux")]
453 pub external_so_lib: Option<(libloading::Library, std::path::PathBuf)>,
454 #[cfg(not(target_os = "linux"))]
455 pub external_so_lib: Option<!>,
457 /// Run a garbage collector for SbTags every N basic blocks.
458 pub(crate) gc_interval: u32,
459 /// The number of blocks that passed since the last SbTag GC pass.
460 pub(crate) since_gc: u32,
461 /// The number of CPUs to be reported by miri.
462 pub(crate) num_cpus: u32,
465 impl<'mir, 'tcx> MiriMachine<'mir, 'tcx> {
466 pub(crate) fn new(config: &MiriConfig, layout_cx: LayoutCx<'tcx, TyCtxt<'tcx>>) -> Self {
467 let local_crates = helpers::get_local_crates(layout_cx.tcx);
469 PrimitiveLayouts::new(layout_cx).expect("Couldn't get layouts of primitive types");
470 let profiler = config.measureme_out.as_ref().map(|out| {
471 measureme::Profiler::new(out).expect("Couldn't create `measureme` profiler")
473 let rng = StdRng::seed_from_u64(config.seed.unwrap_or(0));
474 let stacked_borrows = config.stacked_borrows.then(|| {
475 RefCell::new(stacked_borrows::GlobalStateInner::new(
476 config.tracked_pointer_tags.clone(),
477 config.tracked_call_ids.clone(),
481 let data_race = config.data_race_detector.then(|| data_race::GlobalState::new(config));
486 intptrcast: RefCell::new(intptrcast::GlobalStateInner::new(config)),
487 // `env_vars` depends on a full interpreter so we cannot properly initialize it yet.
488 env_vars: EnvVars::default(),
492 tls: TlsData::default(),
493 isolated_op: config.isolated_op,
494 validate: config.validate,
495 enforce_abi: config.check_abi,
496 file_handler: FileHandler::new(config.mute_stdout_stderr),
497 dir_handler: Default::default(),
499 threads: ThreadManager::default(),
500 static_roots: Vec::new(),
502 string_cache: Default::default(),
503 exported_symbols_cache: FxHashMap::default(),
504 panic_on_unsupported: config.panic_on_unsupported,
505 backtrace_style: config.backtrace_style,
507 extern_statics: FxHashMap::default(),
508 rng: RefCell::new(rng),
509 tracked_alloc_ids: config.tracked_alloc_ids.clone(),
510 check_alignment: config.check_alignment,
511 cmpxchg_weak_failure_rate: config.cmpxchg_weak_failure_rate,
512 mute_stdout_stderr: config.mute_stdout_stderr,
513 weak_memory: config.weak_memory_emulation,
514 preemption_rate: config.preemption_rate,
515 report_progress: config.report_progress,
516 basic_block_count: 0,
517 clock: Clock::new(config.isolated_op == IsolatedOp::Allow),
518 #[cfg(target_os = "linux")]
519 external_so_lib: config.external_so_file.as_ref().map(|lib_file_path| {
520 let target_triple = layout_cx.tcx.sess.opts.target_triple.triple();
521 // Check if host target == the session target.
522 if env!("TARGET") != target_triple {
524 "calling external C functions in linked .so file requires host and target to be the same: host={}, target={}",
529 // Note: it is the user's responsibility to provide a correct SO file.
530 // WATCH OUT: If an invalid/incorrect SO file is specified, this can cause
531 // undefined behaviour in Miri itself!
534 libloading::Library::new(lib_file_path)
535 .expect("failed to read specified extern shared object file")
537 lib_file_path.clone(),
540 #[cfg(not(target_os = "linux"))]
541 external_so_lib: config.external_so_file.as_ref().map(|_| {
542 panic!("loading external .so files is only supported on Linux")
544 gc_interval: config.gc_interval,
546 num_cpus: config.num_cpus,
550 pub(crate) fn late_init(
551 this: &mut MiriInterpCx<'mir, 'tcx>,
553 ) -> InterpResult<'tcx> {
554 EnvVars::init(this, config)?;
555 MiriMachine::init_extern_statics(this)?;
556 ThreadManager::init(this);
560 fn add_extern_static(
561 this: &mut MiriInterpCx<'mir, 'tcx>,
563 ptr: Pointer<Option<Provenance>>,
565 // This got just allocated, so there definitely is a pointer here.
566 let ptr = ptr.into_pointer_or_addr().unwrap();
567 this.machine.extern_statics.try_insert(Symbol::intern(name), ptr).unwrap();
570 fn alloc_extern_static(
571 this: &mut MiriInterpCx<'mir, 'tcx>,
573 val: ImmTy<'tcx, Provenance>,
574 ) -> InterpResult<'tcx> {
575 let place = this.allocate(val.layout, MiriMemoryKind::ExternStatic.into())?;
576 this.write_immediate(*val, &place.into())?;
577 Self::add_extern_static(this, name, place.ptr);
581 /// Sets up the "extern statics" for this machine.
582 fn init_extern_statics(this: &mut MiriInterpCx<'mir, 'tcx>) -> InterpResult<'tcx> {
583 match this.tcx.sess.target.os.as_ref() {
586 Self::add_extern_static(
589 this.machine.env_vars.environ.unwrap().ptr,
591 // A couple zero-initialized pointer-sized extern statics.
592 // Most of them are for weak symbols, which we all set to null (indicating that the
593 // symbol is not supported, and triggering fallback code which ends up calling a
594 // syscall that we do support).
595 for name in &["__cxa_thread_atexit_impl", "getrandom", "statx", "__clock_gettime64"]
597 let val = ImmTy::from_int(0, this.machine.layouts.usize);
598 Self::alloc_extern_static(this, name, val)?;
603 Self::add_extern_static(
606 this.machine.env_vars.environ.unwrap().ptr,
611 let layout = this.machine.layouts.const_raw_ptr;
612 let dlsym = Dlsym::from_str("signal".as_bytes(), &this.tcx.sess.target.os)?
613 .expect("`signal` must be an actual dlsym on android");
614 let ptr = this.create_fn_alloc_ptr(FnVal::Other(dlsym));
615 let val = ImmTy::from_scalar(Scalar::from_pointer(ptr, this), layout);
616 Self::alloc_extern_static(this, "signal", val)?;
617 // A couple zero-initialized pointer-sized extern statics.
618 // Most of them are for weak symbols, which we all set to null (indicating that the
619 // symbol is not supported, and triggering fallback code.)
620 for name in &["bsd_signal"] {
621 let val = ImmTy::from_int(0, this.machine.layouts.usize);
622 Self::alloc_extern_static(this, name, val)?;
627 // This is some obscure hack that is part of the Windows TLS story. It's a `u8`.
628 let val = ImmTy::from_int(0, this.machine.layouts.u8);
629 Self::alloc_extern_static(this, "_tls_used", val)?;
631 _ => {} // No "extern statics" supported on this target
636 pub(crate) fn communicate(&self) -> bool {
637 self.isolated_op == IsolatedOp::Allow
640 /// Check whether the stack frame that this `FrameInfo` refers to is part of a local crate.
641 pub(crate) fn is_local(&self, frame: &FrameInfo<'_>) -> bool {
642 let def_id = frame.instance.def_id();
643 def_id.is_local() || self.local_crates.contains(&def_id.krate)
647 impl VisitTags for MiriMachine<'_, '_> {
648 fn visit_tags(&self, visit: &mut dyn FnMut(SbTag)) {
672 exported_symbols_cache: _,
673 panic_on_unsupported: _,
677 tracked_alloc_ids: _,
679 cmpxchg_weak_failure_rate: _,
680 mute_stdout_stderr: _,
684 basic_block_count: _,
691 threads.visit_tags(visit);
692 tls.visit_tags(visit);
693 env_vars.visit_tags(visit);
694 dir_handler.visit_tags(visit);
695 file_handler.visit_tags(visit);
696 data_race.visit_tags(visit);
697 stacked_borrows.visit_tags(visit);
698 intptrcast.visit_tags(visit);
699 argc.visit_tags(visit);
700 argv.visit_tags(visit);
701 cmd_line.visit_tags(visit);
702 for ptr in extern_statics.values() {
703 ptr.visit_tags(visit);
708 /// A rustc InterpCx for Miri.
709 pub type MiriInterpCx<'mir, 'tcx> = InterpCx<'mir, 'tcx, MiriMachine<'mir, 'tcx>>;
711 /// A little trait that's useful to be inherited by extension traits.
712 pub trait MiriInterpCxExt<'mir, 'tcx> {
713 fn eval_context_ref<'a>(&'a self) -> &'a MiriInterpCx<'mir, 'tcx>;
714 fn eval_context_mut<'a>(&'a mut self) -> &'a mut MiriInterpCx<'mir, 'tcx>;
716 impl<'mir, 'tcx> MiriInterpCxExt<'mir, 'tcx> for MiriInterpCx<'mir, 'tcx> {
718 fn eval_context_ref(&self) -> &MiriInterpCx<'mir, 'tcx> {
722 fn eval_context_mut(&mut self) -> &mut MiriInterpCx<'mir, 'tcx> {
727 /// Machine hook implementations.
728 impl<'mir, 'tcx> Machine<'mir, 'tcx> for MiriMachine<'mir, 'tcx> {
729 type MemoryKind = MiriMemoryKind;
730 type ExtraFnVal = Dlsym;
732 type FrameExtra = FrameData<'tcx>;
733 type AllocExtra = AllocExtra;
735 type Provenance = Provenance;
736 type ProvenanceExtra = ProvenanceExtra;
738 type MemoryMap = MonoHashMap<
740 (MemoryKind<MiriMemoryKind>, Allocation<Provenance, Self::AllocExtra>),
743 const GLOBAL_KIND: Option<MiriMemoryKind> = Some(MiriMemoryKind::Global);
745 const PANIC_ON_ALLOC_FAIL: bool = false;
748 fn enforce_alignment(ecx: &MiriInterpCx<'mir, 'tcx>) -> bool {
749 ecx.machine.check_alignment != AlignmentCheck::None
753 fn use_addr_for_alignment_check(ecx: &MiriInterpCx<'mir, 'tcx>) -> bool {
754 ecx.machine.check_alignment == AlignmentCheck::Int
758 fn enforce_validity(ecx: &MiriInterpCx<'mir, 'tcx>) -> bool {
763 fn enforce_abi(ecx: &MiriInterpCx<'mir, 'tcx>) -> bool {
764 ecx.machine.enforce_abi
768 fn checked_binop_checks_overflow(ecx: &MiriInterpCx<'mir, 'tcx>) -> bool {
769 ecx.tcx.sess.overflow_checks()
773 fn find_mir_or_eval_fn(
774 ecx: &mut MiriInterpCx<'mir, 'tcx>,
775 instance: ty::Instance<'tcx>,
777 args: &[OpTy<'tcx, Provenance>],
778 dest: &PlaceTy<'tcx, Provenance>,
779 ret: Option<mir::BasicBlock>,
780 unwind: StackPopUnwind,
781 ) -> InterpResult<'tcx, Option<(&'mir mir::Body<'tcx>, ty::Instance<'tcx>)>> {
782 ecx.find_mir_or_eval_fn(instance, abi, args, dest, ret, unwind)
787 ecx: &mut MiriInterpCx<'mir, 'tcx>,
790 args: &[OpTy<'tcx, Provenance>],
791 dest: &PlaceTy<'tcx, Provenance>,
792 ret: Option<mir::BasicBlock>,
793 _unwind: StackPopUnwind,
794 ) -> InterpResult<'tcx> {
795 ecx.call_dlsym(fn_val, abi, args, dest, ret)
800 ecx: &mut MiriInterpCx<'mir, 'tcx>,
801 instance: ty::Instance<'tcx>,
802 args: &[OpTy<'tcx, Provenance>],
803 dest: &PlaceTy<'tcx, Provenance>,
804 ret: Option<mir::BasicBlock>,
805 unwind: StackPopUnwind,
806 ) -> InterpResult<'tcx> {
807 ecx.call_intrinsic(instance, args, dest, ret, unwind)
812 ecx: &mut MiriInterpCx<'mir, 'tcx>,
813 msg: &mir::AssertMessage<'tcx>,
814 unwind: Option<mir::BasicBlock>,
815 ) -> InterpResult<'tcx> {
816 ecx.assert_panic(msg, unwind)
820 fn abort(_ecx: &mut MiriInterpCx<'mir, 'tcx>, msg: String) -> InterpResult<'tcx, !> {
821 throw_machine_stop!(TerminationInfo::Abort(msg))
826 ecx: &MiriInterpCx<'mir, 'tcx>,
828 left: &ImmTy<'tcx, Provenance>,
829 right: &ImmTy<'tcx, Provenance>,
830 ) -> InterpResult<'tcx, (Scalar<Provenance>, bool, Ty<'tcx>)> {
831 ecx.binary_ptr_op(bin_op, left, right)
834 fn thread_local_static_base_pointer(
835 ecx: &mut MiriInterpCx<'mir, 'tcx>,
837 ) -> InterpResult<'tcx, Pointer<Provenance>> {
838 ecx.get_or_create_thread_local_alloc(def_id)
841 fn extern_static_base_pointer(
842 ecx: &MiriInterpCx<'mir, 'tcx>,
844 ) -> InterpResult<'tcx, Pointer<Provenance>> {
845 let link_name = ecx.item_link_name(def_id);
846 if let Some(&ptr) = ecx.machine.extern_statics.get(&link_name) {
847 // Various parts of the engine rely on `get_alloc_info` for size and alignment
848 // information. That uses the type information of this static.
849 // Make sure it matches the Miri allocation for this.
850 let Provenance::Concrete { alloc_id, .. } = ptr.provenance else {
851 panic!("extern_statics cannot contain wildcards")
853 let (shim_size, shim_align, _kind) = ecx.get_alloc_info(alloc_id);
854 let extern_decl_layout =
855 ecx.tcx.layout_of(ty::ParamEnv::empty().and(ecx.tcx.type_of(def_id))).unwrap();
856 if extern_decl_layout.size != shim_size || extern_decl_layout.align.abi != shim_align {
858 "`extern` static `{name}` from crate `{krate}` has been declared \
859 with a size of {decl_size} bytes and alignment of {decl_align} bytes, \
860 but Miri emulates it via an extern static shim \
861 with a size of {shim_size} bytes and alignment of {shim_align} bytes",
862 name = ecx.tcx.def_path_str(def_id),
863 krate = ecx.tcx.crate_name(def_id.krate),
864 decl_size = extern_decl_layout.size.bytes(),
865 decl_align = extern_decl_layout.align.abi.bytes(),
866 shim_size = shim_size.bytes(),
867 shim_align = shim_align.bytes(),
873 "`extern` static `{name}` from crate `{krate}` is not supported by Miri",
874 name = ecx.tcx.def_path_str(def_id),
875 krate = ecx.tcx.crate_name(def_id.krate),
880 fn adjust_allocation<'b>(
881 ecx: &MiriInterpCx<'mir, 'tcx>,
883 alloc: Cow<'b, Allocation>,
884 kind: Option<MemoryKind<Self::MemoryKind>>,
885 ) -> InterpResult<'tcx, Cow<'b, Allocation<Self::Provenance, Self::AllocExtra>>> {
886 let kind = kind.expect("we set our STATIC_KIND so this cannot be None");
887 if ecx.machine.tracked_alloc_ids.contains(&id) {
888 ecx.emit_diagnostic(NonHaltingDiagnostic::CreatedAlloc(
896 let alloc = alloc.into_owned();
897 let stacks = ecx.machine.stacked_borrows.as_ref().map(|stacked_borrows| {
898 Stacks::new_allocation(
903 ecx.machine.current_span(),
906 let race_alloc = ecx.machine.data_race.as_ref().map(|data_race| {
907 data_race::AllocExtra::new_allocation(
909 &ecx.machine.threads,
914 let buffer_alloc = ecx.machine.weak_memory.then(weak_memory::AllocExtra::new_allocation);
915 let alloc: Allocation<Provenance, Self::AllocExtra> = alloc.adjust_from_tcx(
918 stacked_borrows: stacks.map(RefCell::new),
919 data_race: race_alloc,
920 weak_memory: buffer_alloc,
922 |ptr| ecx.global_base_pointer(ptr),
924 Ok(Cow::Owned(alloc))
927 fn adjust_alloc_base_pointer(
928 ecx: &MiriInterpCx<'mir, 'tcx>,
929 ptr: Pointer<AllocId>,
930 ) -> Pointer<Provenance> {
931 if cfg!(debug_assertions) {
932 // The machine promises to never call us on thread-local or extern statics.
933 let alloc_id = ptr.provenance;
934 match ecx.tcx.try_get_global_alloc(alloc_id) {
935 Some(GlobalAlloc::Static(def_id)) if ecx.tcx.is_thread_local_static(def_id) => {
936 panic!("adjust_alloc_base_pointer called on thread-local static")
938 Some(GlobalAlloc::Static(def_id)) if ecx.tcx.is_foreign_item(def_id) => {
939 panic!("adjust_alloc_base_pointer called on extern static")
944 let absolute_addr = intptrcast::GlobalStateInner::rel_ptr_to_addr(ecx, ptr);
945 let sb_tag = if let Some(stacked_borrows) = &ecx.machine.stacked_borrows {
946 stacked_borrows.borrow_mut().base_ptr_tag(ptr.provenance, &ecx.machine)
948 // Value does not matter, SB is disabled
952 Provenance::Concrete { alloc_id: ptr.provenance, sb: sb_tag },
953 Size::from_bytes(absolute_addr),
958 fn ptr_from_addr_cast(
959 ecx: &MiriInterpCx<'mir, 'tcx>,
961 ) -> InterpResult<'tcx, Pointer<Option<Self::Provenance>>> {
962 intptrcast::GlobalStateInner::ptr_from_addr_cast(ecx, addr)
966 ecx: &mut InterpCx<'mir, 'tcx, Self>,
967 ptr: Pointer<Self::Provenance>,
968 ) -> InterpResult<'tcx> {
969 match ptr.provenance {
970 Provenance::Concrete { alloc_id, sb } =>
971 intptrcast::GlobalStateInner::expose_ptr(ecx, alloc_id, sb),
972 Provenance::Wildcard => {
973 // No need to do anything for wildcard pointers as
974 // their provenances have already been previously exposed.
980 /// Convert a pointer with provenance into an allocation-offset pair,
981 /// or a `None` with an absolute address if that conversion is not possible.
983 ecx: &MiriInterpCx<'mir, 'tcx>,
984 ptr: Pointer<Self::Provenance>,
985 ) -> Option<(AllocId, Size, Self::ProvenanceExtra)> {
986 let rel = intptrcast::GlobalStateInner::abs_ptr_to_rel(ecx, ptr);
988 rel.map(|(alloc_id, size)| {
989 let sb = match ptr.provenance {
990 Provenance::Concrete { sb, .. } => ProvenanceExtra::Concrete(sb),
991 Provenance::Wildcard => ProvenanceExtra::Wildcard,
998 fn before_memory_read(
1001 alloc_extra: &AllocExtra,
1002 (alloc_id, prov_extra): (AllocId, Self::ProvenanceExtra),
1004 ) -> InterpResult<'tcx> {
1005 if let Some(data_race) = &alloc_extra.data_race {
1009 machine.data_race.as_ref().unwrap(),
1013 if let Some(stacked_borrows) = &alloc_extra.stacked_borrows {
1014 stacked_borrows.borrow_mut().before_memory_read(
1018 machine.stacked_borrows.as_ref().unwrap(),
1019 machine.current_span(),
1023 if let Some(weak_memory) = &alloc_extra.weak_memory {
1024 weak_memory.memory_accessed(range, machine.data_race.as_ref().unwrap());
1030 fn before_memory_write(
1033 alloc_extra: &mut AllocExtra,
1034 (alloc_id, prov_extra): (AllocId, Self::ProvenanceExtra),
1036 ) -> InterpResult<'tcx> {
1037 if let Some(data_race) = &mut alloc_extra.data_race {
1041 machine.data_race.as_mut().unwrap(),
1045 if let Some(stacked_borrows) = &mut alloc_extra.stacked_borrows {
1046 stacked_borrows.get_mut().before_memory_write(
1050 machine.stacked_borrows.as_ref().unwrap(),
1051 machine.current_span(),
1055 if let Some(weak_memory) = &alloc_extra.weak_memory {
1056 weak_memory.memory_accessed(range, machine.data_race.as_ref().unwrap());
1062 fn before_memory_deallocation(
1065 alloc_extra: &mut AllocExtra,
1066 (alloc_id, prove_extra): (AllocId, Self::ProvenanceExtra),
1068 ) -> InterpResult<'tcx> {
1069 if machine.tracked_alloc_ids.contains(&alloc_id) {
1070 machine.emit_diagnostic(NonHaltingDiagnostic::FreedAlloc(alloc_id));
1072 if let Some(data_race) = &mut alloc_extra.data_race {
1073 data_race.deallocate(
1076 machine.data_race.as_mut().unwrap(),
1080 if let Some(stacked_borrows) = &mut alloc_extra.stacked_borrows {
1081 stacked_borrows.get_mut().before_memory_deallocation(
1085 machine.stacked_borrows.as_ref().unwrap(),
1086 machine.current_span(),
1096 ecx: &mut InterpCx<'mir, 'tcx, Self>,
1097 kind: mir::RetagKind,
1098 place: &PlaceTy<'tcx, Provenance>,
1099 ) -> InterpResult<'tcx> {
1100 if ecx.machine.stacked_borrows.is_some() { ecx.retag(kind, place) } else { Ok(()) }
1104 fn init_frame_extra(
1105 ecx: &mut InterpCx<'mir, 'tcx, Self>,
1106 frame: Frame<'mir, 'tcx, Provenance>,
1107 ) -> InterpResult<'tcx, Frame<'mir, 'tcx, Provenance, FrameData<'tcx>>> {
1108 // Start recording our event before doing anything else
1109 let timing = if let Some(profiler) = ecx.machine.profiler.as_ref() {
1110 let fn_name = frame.instance.to_string();
1111 let entry = ecx.machine.string_cache.entry(fn_name.clone());
1112 let name = entry.or_insert_with(|| profiler.alloc_string(&*fn_name));
1114 Some(profiler.start_recording_interval_event_detached(
1116 measureme::EventId::from_label(*name),
1117 ecx.get_active_thread().to_u32(),
1123 let stacked_borrows = ecx.machine.stacked_borrows.as_ref();
1125 let extra = FrameData {
1126 stacked_borrows: stacked_borrows.map(|sb| sb.borrow_mut().new_frame(&ecx.machine)),
1130 Ok(frame.with_extra(extra))
1134 ecx: &'a InterpCx<'mir, 'tcx, Self>,
1135 ) -> &'a [Frame<'mir, 'tcx, Self::Provenance, Self::FrameExtra>] {
1136 ecx.active_thread_stack()
1140 ecx: &'a mut InterpCx<'mir, 'tcx, Self>,
1141 ) -> &'a mut Vec<Frame<'mir, 'tcx, Self::Provenance, Self::FrameExtra>> {
1142 ecx.active_thread_stack_mut()
1145 fn before_terminator(ecx: &mut InterpCx<'mir, 'tcx, Self>) -> InterpResult<'tcx> {
1146 ecx.machine.basic_block_count += 1u64; // a u64 that is only incremented by 1 will "never" overflow
1147 ecx.machine.since_gc += 1;
1148 // Possibly report our progress.
1149 if let Some(report_progress) = ecx.machine.report_progress {
1150 if ecx.machine.basic_block_count % u64::from(report_progress) == 0 {
1151 ecx.emit_diagnostic(NonHaltingDiagnostic::ProgressReport {
1152 block_count: ecx.machine.basic_block_count,
1157 // Search for SbTags to find all live pointers, then remove all other tags from borrow
1159 // When debug assertions are enabled, run the GC as often as possible so that any cases
1160 // where it mistakenly removes an important tag become visible.
1161 if ecx.machine.gc_interval > 0 && ecx.machine.since_gc >= ecx.machine.gc_interval {
1162 ecx.machine.since_gc = 0;
1163 ecx.garbage_collect_tags()?;
1166 // These are our preemption points.
1167 ecx.maybe_preempt_active_thread();
1169 // Make sure some time passes.
1170 ecx.machine.clock.tick();
1176 fn after_stack_push(ecx: &mut InterpCx<'mir, 'tcx, Self>) -> InterpResult<'tcx> {
1177 if ecx.machine.stacked_borrows.is_some() { ecx.retag_return_place() } else { Ok(()) }
1182 ecx: &mut InterpCx<'mir, 'tcx, Self>,
1183 mut frame: Frame<'mir, 'tcx, Provenance, FrameData<'tcx>>,
1185 ) -> InterpResult<'tcx, StackPopJump> {
1186 let timing = frame.extra.timing.take();
1187 if let Some(stacked_borrows) = &ecx.machine.stacked_borrows {
1188 stacked_borrows.borrow_mut().end_call(&frame.extra);
1190 let res = ecx.handle_stack_pop_unwind(frame.extra, unwinding);
1191 if let Some(profiler) = ecx.machine.profiler.as_ref() {
1192 profiler.finish_recording_interval_event(timing.unwrap());