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(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 fmt::Debug for Provenance {
180 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
182 Provenance::Concrete { alloc_id, sb } => {
183 // Forward `alternate` flag to `alloc_id` printing.
185 write!(f, "[{alloc_id:#?}]")?;
187 write!(f, "[{alloc_id:?}]")?;
189 // Print Stacked Borrows tag.
190 write!(f, "{sb:?}")?;
192 Provenance::Wildcard => {
193 write!(f, "[wildcard]")?;
200 impl interpret::Provenance for Provenance {
201 /// We use absolute addresses in the `offset` of a `Pointer<Provenance>`.
202 const OFFSET_IS_ADDR: bool = true;
204 fn get_alloc_id(self) -> Option<AllocId> {
206 Provenance::Concrete { alloc_id, .. } => Some(alloc_id),
207 Provenance::Wildcard => None,
211 fn join(left: Option<Self>, right: Option<Self>) -> Option<Self> {
212 match (left, right) {
213 // If both are the *same* concrete tag, that is the result.
215 Some(Provenance::Concrete { alloc_id: left_alloc, sb: left_sb }),
216 Some(Provenance::Concrete { alloc_id: right_alloc, sb: right_sb }),
217 ) if left_alloc == right_alloc && left_sb == right_sb => left,
218 // If one side is a wildcard, the best possible outcome is that it is equal to the other
219 // one, and we use that.
220 (Some(Provenance::Wildcard), o) | (o, Some(Provenance::Wildcard)) => o,
221 // Otherwise, fall back to `None`.
227 impl fmt::Debug for ProvenanceExtra {
228 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
230 ProvenanceExtra::Concrete(pid) => write!(f, "{pid:?}"),
231 ProvenanceExtra::Wildcard => write!(f, "<wildcard>"),
236 impl ProvenanceExtra {
237 pub fn and_then<T>(self, f: impl FnOnce(SbTag) -> Option<T>) -> Option<T> {
239 ProvenanceExtra::Concrete(pid) => f(pid),
240 ProvenanceExtra::Wildcard => None,
245 /// Extra per-allocation data
246 #[derive(Debug, Clone)]
247 pub struct AllocExtra {
248 /// Stacked Borrows state is only added if it is enabled.
249 pub stacked_borrows: Option<stacked_borrows::AllocExtra>,
250 /// Data race detection via the use of a vector-clock,
251 /// this is only added if it is enabled.
252 pub data_race: Option<data_race::AllocExtra>,
253 /// Weak memory emulation via the use of store buffers,
254 /// this is only added if it is enabled.
255 pub weak_memory: Option<weak_memory::AllocExtra>,
258 impl VisitTags for AllocExtra {
259 fn visit_tags(&self, visit: &mut dyn FnMut(SbTag)) {
260 let AllocExtra { stacked_borrows, data_race, weak_memory } = self;
262 stacked_borrows.visit_tags(visit);
263 data_race.visit_tags(visit);
264 weak_memory.visit_tags(visit);
268 /// Precomputed layouts of primitive types
269 pub struct PrimitiveLayouts<'tcx> {
270 pub unit: TyAndLayout<'tcx>,
271 pub i8: TyAndLayout<'tcx>,
272 pub i16: TyAndLayout<'tcx>,
273 pub i32: TyAndLayout<'tcx>,
274 pub i64: TyAndLayout<'tcx>,
275 pub i128: TyAndLayout<'tcx>,
276 pub isize: TyAndLayout<'tcx>,
277 pub u8: TyAndLayout<'tcx>,
278 pub u16: TyAndLayout<'tcx>,
279 pub u32: TyAndLayout<'tcx>,
280 pub u64: TyAndLayout<'tcx>,
281 pub u128: TyAndLayout<'tcx>,
282 pub usize: TyAndLayout<'tcx>,
283 pub bool: TyAndLayout<'tcx>,
284 pub mut_raw_ptr: TyAndLayout<'tcx>, // *mut ()
285 pub const_raw_ptr: TyAndLayout<'tcx>, // *const ()
288 impl<'mir, 'tcx: 'mir> PrimitiveLayouts<'tcx> {
289 fn new(layout_cx: LayoutCx<'tcx, TyCtxt<'tcx>>) -> Result<Self, LayoutError<'tcx>> {
290 let tcx = layout_cx.tcx;
291 let mut_raw_ptr = tcx.mk_ptr(TypeAndMut { ty: tcx.types.unit, mutbl: Mutability::Mut });
292 let const_raw_ptr = tcx.mk_ptr(TypeAndMut { ty: tcx.types.unit, mutbl: Mutability::Not });
294 unit: layout_cx.layout_of(tcx.mk_unit())?,
295 i8: layout_cx.layout_of(tcx.types.i8)?,
296 i16: layout_cx.layout_of(tcx.types.i16)?,
297 i32: layout_cx.layout_of(tcx.types.i32)?,
298 i64: layout_cx.layout_of(tcx.types.i64)?,
299 i128: layout_cx.layout_of(tcx.types.i128)?,
300 isize: layout_cx.layout_of(tcx.types.isize)?,
301 u8: layout_cx.layout_of(tcx.types.u8)?,
302 u16: layout_cx.layout_of(tcx.types.u16)?,
303 u32: layout_cx.layout_of(tcx.types.u32)?,
304 u64: layout_cx.layout_of(tcx.types.u64)?,
305 u128: layout_cx.layout_of(tcx.types.u128)?,
306 usize: layout_cx.layout_of(tcx.types.usize)?,
307 bool: layout_cx.layout_of(tcx.types.bool)?,
308 mut_raw_ptr: layout_cx.layout_of(mut_raw_ptr)?,
309 const_raw_ptr: layout_cx.layout_of(const_raw_ptr)?,
313 pub fn uint(&self, size: Size) -> Option<TyAndLayout<'tcx>> {
316 16 => Some(self.u16),
317 32 => Some(self.u32),
318 64 => Some(self.u64),
319 128 => Some(self.u128),
324 pub fn int(&self, size: Size) -> Option<TyAndLayout<'tcx>> {
327 16 => Some(self.i16),
328 32 => Some(self.i32),
329 64 => Some(self.i64),
330 128 => Some(self.i128),
336 /// The machine itself.
338 /// If you add anything here that stores machine values, remember to update
339 /// `visit_all_machine_values`!
340 pub struct MiriMachine<'mir, 'tcx> {
341 // We carry a copy of the global `TyCtxt` for convenience, so methods taking just `&Evaluator` have `tcx` access.
342 pub tcx: TyCtxt<'tcx>,
344 /// Stacked Borrows global data.
345 pub stacked_borrows: Option<stacked_borrows::GlobalState>,
347 /// Data race detector global data.
348 pub data_race: Option<data_race::GlobalState>,
350 /// Ptr-int-cast module global data.
351 pub intptrcast: intptrcast::GlobalState,
353 /// Environment variables set by `setenv`.
354 /// Miri does not expose env vars from the host to the emulated program.
355 pub(crate) env_vars: EnvVars<'tcx>,
357 /// Program arguments (`Option` because we can only initialize them after creating the ecx).
358 /// These are *pointers* to argc/argv because macOS.
359 /// We also need the full command line as one string because of Windows.
360 pub(crate) argc: Option<MemPlace<Provenance>>,
361 pub(crate) argv: Option<MemPlace<Provenance>>,
362 pub(crate) cmd_line: Option<MemPlace<Provenance>>,
365 pub(crate) tls: TlsData<'tcx>,
367 /// What should Miri do when an op requires communicating with the host,
368 /// such as accessing host env vars, random number generation, and
369 /// file system access.
370 pub(crate) isolated_op: IsolatedOp,
372 /// Whether to enforce the validity invariant.
373 pub(crate) validate: bool,
375 /// Whether to enforce [ABI](Abi) of function calls.
376 pub(crate) enforce_abi: bool,
378 /// The table of file descriptors.
379 pub(crate) file_handler: shims::unix::FileHandler,
380 /// The table of directory descriptors.
381 pub(crate) dir_handler: shims::unix::DirHandler,
383 /// This machine's monotone clock.
384 pub(crate) clock: Clock,
386 /// The set of threads.
387 pub(crate) threads: ThreadManager<'mir, 'tcx>,
389 /// Precomputed `TyLayout`s for primitive data types that are commonly used inside Miri.
390 pub(crate) layouts: PrimitiveLayouts<'tcx>,
392 /// Allocations that are considered roots of static memory (that may leak).
393 pub(crate) static_roots: Vec<AllocId>,
395 /// The `measureme` profiler used to record timing information about
396 /// the emulated program.
397 profiler: Option<measureme::Profiler>,
398 /// Used with `profiler` to cache the `StringId`s for event names
399 /// uesd with `measureme`.
400 string_cache: FxHashMap<String, measureme::StringId>,
402 /// Cache of `Instance` exported under the given `Symbol` name.
403 /// `None` means no `Instance` exported under the given name is found.
404 pub(crate) exported_symbols_cache: FxHashMap<Symbol, Option<Instance<'tcx>>>,
406 /// Whether to raise a panic in the context of the evaluated process when unsupported
407 /// functionality is encountered. If `false`, an error is propagated in the Miri application context
408 /// instead (default behavior)
409 pub(crate) panic_on_unsupported: bool,
411 /// Equivalent setting as RUST_BACKTRACE on encountering an error.
412 pub(crate) backtrace_style: BacktraceStyle,
414 /// Crates which are considered local for the purposes of error reporting.
415 pub(crate) local_crates: Vec<CrateNum>,
417 /// Mapping extern static names to their base pointer.
418 extern_statics: FxHashMap<Symbol, Pointer<Provenance>>,
420 /// The random number generator used for resolving non-determinism.
421 /// Needs to be queried by ptr_to_int, hence needs interior mutability.
422 pub(crate) rng: RefCell<StdRng>,
424 /// The allocation IDs to report when they are being allocated
425 /// (helps for debugging memory leaks and use after free bugs).
426 tracked_alloc_ids: FxHashSet<AllocId>,
428 /// Controls whether alignment of memory accesses is being checked.
429 pub(crate) check_alignment: AlignmentCheck,
431 /// Failure rate of compare_exchange_weak, between 0.0 and 1.0
432 pub(crate) cmpxchg_weak_failure_rate: f64,
434 /// Corresponds to -Zmiri-mute-stdout-stderr and doesn't write the output but acts as if it succeeded.
435 pub(crate) mute_stdout_stderr: bool,
437 /// Whether weak memory emulation is enabled
438 pub(crate) weak_memory: bool,
440 /// The probability of the active thread being preempted at the end of each basic block.
441 pub(crate) preemption_rate: f64,
443 /// If `Some`, we will report the current stack every N basic blocks.
444 pub(crate) report_progress: Option<u32>,
445 // The total number of blocks that have been executed.
446 pub(crate) basic_block_count: u64,
448 /// Handle of the optional shared object file for external functions.
449 #[cfg(target_os = "linux")]
450 pub external_so_lib: Option<(libloading::Library, std::path::PathBuf)>,
451 #[cfg(not(target_os = "linux"))]
452 pub external_so_lib: Option<!>,
454 /// Run a garbage collector for SbTags every N basic blocks.
455 pub(crate) gc_interval: u32,
456 /// The number of blocks that passed since the last SbTag GC pass.
457 pub(crate) since_gc: u32,
458 /// The number of CPUs to be reported by miri.
459 pub(crate) num_cpus: u32,
462 impl<'mir, 'tcx> MiriMachine<'mir, 'tcx> {
463 pub(crate) fn new(config: &MiriConfig, layout_cx: LayoutCx<'tcx, TyCtxt<'tcx>>) -> Self {
464 let local_crates = helpers::get_local_crates(layout_cx.tcx);
466 PrimitiveLayouts::new(layout_cx).expect("Couldn't get layouts of primitive types");
467 let profiler = config.measureme_out.as_ref().map(|out| {
468 measureme::Profiler::new(out).expect("Couldn't create `measureme` profiler")
470 let rng = StdRng::seed_from_u64(config.seed.unwrap_or(0));
471 let stacked_borrows = config.stacked_borrows.then(|| {
472 RefCell::new(stacked_borrows::GlobalStateInner::new(
473 config.tracked_pointer_tags.clone(),
474 config.tracked_call_ids.clone(),
478 let data_race = config.data_race_detector.then(|| data_race::GlobalState::new(config));
483 intptrcast: RefCell::new(intptrcast::GlobalStateInner::new(config)),
484 // `env_vars` depends on a full interpreter so we cannot properly initialize it yet.
485 env_vars: EnvVars::default(),
489 tls: TlsData::default(),
490 isolated_op: config.isolated_op,
491 validate: config.validate,
492 enforce_abi: config.check_abi,
493 file_handler: FileHandler::new(config.mute_stdout_stderr),
494 dir_handler: Default::default(),
496 threads: ThreadManager::default(),
497 static_roots: Vec::new(),
499 string_cache: Default::default(),
500 exported_symbols_cache: FxHashMap::default(),
501 panic_on_unsupported: config.panic_on_unsupported,
502 backtrace_style: config.backtrace_style,
504 extern_statics: FxHashMap::default(),
505 rng: RefCell::new(rng),
506 tracked_alloc_ids: config.tracked_alloc_ids.clone(),
507 check_alignment: config.check_alignment,
508 cmpxchg_weak_failure_rate: config.cmpxchg_weak_failure_rate,
509 mute_stdout_stderr: config.mute_stdout_stderr,
510 weak_memory: config.weak_memory_emulation,
511 preemption_rate: config.preemption_rate,
512 report_progress: config.report_progress,
513 basic_block_count: 0,
514 clock: Clock::new(config.isolated_op == IsolatedOp::Allow),
515 #[cfg(target_os = "linux")]
516 external_so_lib: config.external_so_file.as_ref().map(|lib_file_path| {
517 let target_triple = layout_cx.tcx.sess.opts.target_triple.triple();
518 // Check if host target == the session target.
519 if env!("TARGET") != target_triple {
521 "calling external C functions in linked .so file requires host and target to be the same: host={}, target={}",
526 // Note: it is the user's responsibility to provide a correct SO file.
527 // WATCH OUT: If an invalid/incorrect SO file is specified, this can cause
528 // undefined behaviour in Miri itself!
531 libloading::Library::new(lib_file_path)
532 .expect("failed to read specified extern shared object file")
534 lib_file_path.clone(),
537 #[cfg(not(target_os = "linux"))]
538 external_so_lib: config.external_so_file.as_ref().map(|_| {
539 panic!("loading external .so files is only supported on Linux")
541 gc_interval: config.gc_interval,
543 num_cpus: config.num_cpus,
547 pub(crate) fn late_init(
548 this: &mut MiriInterpCx<'mir, 'tcx>,
550 ) -> InterpResult<'tcx> {
551 EnvVars::init(this, config)?;
552 MiriMachine::init_extern_statics(this)?;
553 ThreadManager::init(this);
557 fn add_extern_static(
558 this: &mut MiriInterpCx<'mir, 'tcx>,
560 ptr: Pointer<Option<Provenance>>,
562 // This got just allocated, so there definitely is a pointer here.
563 let ptr = ptr.into_pointer_or_addr().unwrap();
564 this.machine.extern_statics.try_insert(Symbol::intern(name), ptr).unwrap();
567 fn alloc_extern_static(
568 this: &mut MiriInterpCx<'mir, 'tcx>,
570 val: ImmTy<'tcx, Provenance>,
571 ) -> InterpResult<'tcx> {
572 let place = this.allocate(val.layout, MiriMemoryKind::ExternStatic.into())?;
573 this.write_immediate(*val, &place.into())?;
574 Self::add_extern_static(this, name, place.ptr);
578 /// Sets up the "extern statics" for this machine.
579 fn init_extern_statics(this: &mut MiriInterpCx<'mir, 'tcx>) -> InterpResult<'tcx> {
580 match this.tcx.sess.target.os.as_ref() {
583 Self::add_extern_static(
586 this.machine.env_vars.environ.unwrap().ptr,
588 // A couple zero-initialized pointer-sized extern statics.
589 // Most of them are for weak symbols, which we all set to null (indicating that the
590 // symbol is not supported, and triggering fallback code which ends up calling a
591 // syscall that we do support).
592 for name in &["__cxa_thread_atexit_impl", "getrandom", "statx", "__clock_gettime64"]
594 let val = ImmTy::from_int(0, this.machine.layouts.usize);
595 Self::alloc_extern_static(this, name, val)?;
600 Self::add_extern_static(
603 this.machine.env_vars.environ.unwrap().ptr,
608 let layout = this.machine.layouts.const_raw_ptr;
609 let dlsym = Dlsym::from_str("signal".as_bytes(), &this.tcx.sess.target.os)?
610 .expect("`signal` must be an actual dlsym on android");
611 let ptr = this.create_fn_alloc_ptr(FnVal::Other(dlsym));
612 let val = ImmTy::from_scalar(Scalar::from_pointer(ptr, this), layout);
613 Self::alloc_extern_static(this, "signal", val)?;
614 // A couple zero-initialized pointer-sized extern statics.
615 // Most of them are for weak symbols, which we all set to null (indicating that the
616 // symbol is not supported, and triggering fallback code.)
617 for name in &["bsd_signal"] {
618 let val = ImmTy::from_int(0, this.machine.layouts.usize);
619 Self::alloc_extern_static(this, name, val)?;
624 // This is some obscure hack that is part of the Windows TLS story. It's a `u8`.
625 let val = ImmTy::from_int(0, this.machine.layouts.u8);
626 Self::alloc_extern_static(this, "_tls_used", val)?;
628 _ => {} // No "extern statics" supported on this target
633 pub(crate) fn communicate(&self) -> bool {
634 self.isolated_op == IsolatedOp::Allow
637 /// Check whether the stack frame that this `FrameInfo` refers to is part of a local crate.
638 pub(crate) fn is_local(&self, frame: &FrameInfo<'_>) -> bool {
639 let def_id = frame.instance.def_id();
640 def_id.is_local() || self.local_crates.contains(&def_id.krate)
644 impl VisitTags for MiriMachine<'_, '_> {
645 fn visit_tags(&self, visit: &mut dyn FnMut(SbTag)) {
669 exported_symbols_cache: _,
670 panic_on_unsupported: _,
674 tracked_alloc_ids: _,
676 cmpxchg_weak_failure_rate: _,
677 mute_stdout_stderr: _,
681 basic_block_count: _,
688 threads.visit_tags(visit);
689 tls.visit_tags(visit);
690 env_vars.visit_tags(visit);
691 dir_handler.visit_tags(visit);
692 file_handler.visit_tags(visit);
693 data_race.visit_tags(visit);
694 stacked_borrows.visit_tags(visit);
695 intptrcast.visit_tags(visit);
696 argc.visit_tags(visit);
697 argv.visit_tags(visit);
698 cmd_line.visit_tags(visit);
699 for ptr in extern_statics.values() {
700 ptr.visit_tags(visit);
705 /// A rustc InterpCx for Miri.
706 pub type MiriInterpCx<'mir, 'tcx> = InterpCx<'mir, 'tcx, MiriMachine<'mir, 'tcx>>;
708 /// A little trait that's useful to be inherited by extension traits.
709 pub trait MiriInterpCxExt<'mir, 'tcx> {
710 fn eval_context_ref<'a>(&'a self) -> &'a MiriInterpCx<'mir, 'tcx>;
711 fn eval_context_mut<'a>(&'a mut self) -> &'a mut MiriInterpCx<'mir, 'tcx>;
713 impl<'mir, 'tcx> MiriInterpCxExt<'mir, 'tcx> for MiriInterpCx<'mir, 'tcx> {
715 fn eval_context_ref(&self) -> &MiriInterpCx<'mir, 'tcx> {
719 fn eval_context_mut(&mut self) -> &mut MiriInterpCx<'mir, 'tcx> {
724 /// Machine hook implementations.
725 impl<'mir, 'tcx> Machine<'mir, 'tcx> for MiriMachine<'mir, 'tcx> {
726 type MemoryKind = MiriMemoryKind;
727 type ExtraFnVal = Dlsym;
729 type FrameExtra = FrameData<'tcx>;
730 type AllocExtra = AllocExtra;
732 type Provenance = Provenance;
733 type ProvenanceExtra = ProvenanceExtra;
735 type MemoryMap = MonoHashMap<
737 (MemoryKind<MiriMemoryKind>, Allocation<Provenance, Self::AllocExtra>),
740 const GLOBAL_KIND: Option<MiriMemoryKind> = Some(MiriMemoryKind::Global);
742 const PANIC_ON_ALLOC_FAIL: bool = false;
745 fn enforce_alignment(ecx: &MiriInterpCx<'mir, 'tcx>) -> bool {
746 ecx.machine.check_alignment != AlignmentCheck::None
750 fn use_addr_for_alignment_check(ecx: &MiriInterpCx<'mir, 'tcx>) -> bool {
751 ecx.machine.check_alignment == AlignmentCheck::Int
755 fn enforce_validity(ecx: &MiriInterpCx<'mir, 'tcx>) -> bool {
760 fn enforce_abi(ecx: &MiriInterpCx<'mir, 'tcx>) -> bool {
761 ecx.machine.enforce_abi
765 fn checked_binop_checks_overflow(ecx: &MiriInterpCx<'mir, 'tcx>) -> bool {
766 ecx.tcx.sess.overflow_checks()
770 fn find_mir_or_eval_fn(
771 ecx: &mut MiriInterpCx<'mir, 'tcx>,
772 instance: ty::Instance<'tcx>,
774 args: &[OpTy<'tcx, Provenance>],
775 dest: &PlaceTy<'tcx, Provenance>,
776 ret: Option<mir::BasicBlock>,
777 unwind: StackPopUnwind,
778 ) -> InterpResult<'tcx, Option<(&'mir mir::Body<'tcx>, ty::Instance<'tcx>)>> {
779 ecx.find_mir_or_eval_fn(instance, abi, args, dest, ret, unwind)
784 ecx: &mut MiriInterpCx<'mir, 'tcx>,
787 args: &[OpTy<'tcx, Provenance>],
788 dest: &PlaceTy<'tcx, Provenance>,
789 ret: Option<mir::BasicBlock>,
790 _unwind: StackPopUnwind,
791 ) -> InterpResult<'tcx> {
792 ecx.call_dlsym(fn_val, abi, args, dest, ret)
797 ecx: &mut MiriInterpCx<'mir, 'tcx>,
798 instance: ty::Instance<'tcx>,
799 args: &[OpTy<'tcx, Provenance>],
800 dest: &PlaceTy<'tcx, Provenance>,
801 ret: Option<mir::BasicBlock>,
802 unwind: StackPopUnwind,
803 ) -> InterpResult<'tcx> {
804 ecx.call_intrinsic(instance, args, dest, ret, unwind)
809 ecx: &mut MiriInterpCx<'mir, 'tcx>,
810 msg: &mir::AssertMessage<'tcx>,
811 unwind: Option<mir::BasicBlock>,
812 ) -> InterpResult<'tcx> {
813 ecx.assert_panic(msg, unwind)
817 fn abort(_ecx: &mut MiriInterpCx<'mir, 'tcx>, msg: String) -> InterpResult<'tcx, !> {
818 throw_machine_stop!(TerminationInfo::Abort(msg))
823 ecx: &MiriInterpCx<'mir, 'tcx>,
825 left: &ImmTy<'tcx, Provenance>,
826 right: &ImmTy<'tcx, Provenance>,
827 ) -> InterpResult<'tcx, (Scalar<Provenance>, bool, Ty<'tcx>)> {
828 ecx.binary_ptr_op(bin_op, left, right)
831 fn thread_local_static_base_pointer(
832 ecx: &mut MiriInterpCx<'mir, 'tcx>,
834 ) -> InterpResult<'tcx, Pointer<Provenance>> {
835 ecx.get_or_create_thread_local_alloc(def_id)
838 fn extern_static_base_pointer(
839 ecx: &MiriInterpCx<'mir, 'tcx>,
841 ) -> InterpResult<'tcx, Pointer<Provenance>> {
842 let link_name = ecx.item_link_name(def_id);
843 if let Some(&ptr) = ecx.machine.extern_statics.get(&link_name) {
844 // Various parts of the engine rely on `get_alloc_info` for size and alignment
845 // information. That uses the type information of this static.
846 // Make sure it matches the Miri allocation for this.
847 let Provenance::Concrete { alloc_id, .. } = ptr.provenance else {
848 panic!("extern_statics cannot contain wildcards")
850 let (shim_size, shim_align, _kind) = ecx.get_alloc_info(alloc_id);
851 let extern_decl_layout =
852 ecx.tcx.layout_of(ty::ParamEnv::empty().and(ecx.tcx.type_of(def_id))).unwrap();
853 if extern_decl_layout.size != shim_size || extern_decl_layout.align.abi != shim_align {
855 "`extern` static `{name}` from crate `{krate}` has been declared \
856 with a size of {decl_size} bytes and alignment of {decl_align} bytes, \
857 but Miri emulates it via an extern static shim \
858 with a size of {shim_size} bytes and alignment of {shim_align} bytes",
859 name = ecx.tcx.def_path_str(def_id),
860 krate = ecx.tcx.crate_name(def_id.krate),
861 decl_size = extern_decl_layout.size.bytes(),
862 decl_align = extern_decl_layout.align.abi.bytes(),
863 shim_size = shim_size.bytes(),
864 shim_align = shim_align.bytes(),
870 "`extern` static `{name}` from crate `{krate}` is not supported by Miri",
871 name = ecx.tcx.def_path_str(def_id),
872 krate = ecx.tcx.crate_name(def_id.krate),
877 fn adjust_allocation<'b>(
878 ecx: &MiriInterpCx<'mir, 'tcx>,
880 alloc: Cow<'b, Allocation>,
881 kind: Option<MemoryKind<Self::MemoryKind>>,
882 ) -> InterpResult<'tcx, Cow<'b, Allocation<Self::Provenance, Self::AllocExtra>>> {
883 let kind = kind.expect("we set our STATIC_KIND so this cannot be None");
884 if ecx.machine.tracked_alloc_ids.contains(&id) {
885 ecx.emit_diagnostic(NonHaltingDiagnostic::CreatedAlloc(
893 let alloc = alloc.into_owned();
894 let stacks = ecx.machine.stacked_borrows.as_ref().map(|stacked_borrows| {
895 Stacks::new_allocation(
900 ecx.machine.current_span(),
903 let race_alloc = ecx.machine.data_race.as_ref().map(|data_race| {
904 data_race::AllocExtra::new_allocation(
906 &ecx.machine.threads,
911 let buffer_alloc = ecx.machine.weak_memory.then(weak_memory::AllocExtra::new_allocation);
912 let alloc: Allocation<Provenance, Self::AllocExtra> = alloc.adjust_from_tcx(
915 stacked_borrows: stacks.map(RefCell::new),
916 data_race: race_alloc,
917 weak_memory: buffer_alloc,
919 |ptr| ecx.global_base_pointer(ptr),
921 Ok(Cow::Owned(alloc))
924 fn adjust_alloc_base_pointer(
925 ecx: &MiriInterpCx<'mir, 'tcx>,
926 ptr: Pointer<AllocId>,
927 ) -> Pointer<Provenance> {
928 if cfg!(debug_assertions) {
929 // The machine promises to never call us on thread-local or extern statics.
930 let alloc_id = ptr.provenance;
931 match ecx.tcx.try_get_global_alloc(alloc_id) {
932 Some(GlobalAlloc::Static(def_id)) if ecx.tcx.is_thread_local_static(def_id) => {
933 panic!("adjust_alloc_base_pointer called on thread-local static")
935 Some(GlobalAlloc::Static(def_id)) if ecx.tcx.is_foreign_item(def_id) => {
936 panic!("adjust_alloc_base_pointer called on extern static")
941 let absolute_addr = intptrcast::GlobalStateInner::rel_ptr_to_addr(ecx, ptr);
942 let sb_tag = if let Some(stacked_borrows) = &ecx.machine.stacked_borrows {
943 stacked_borrows.borrow_mut().base_ptr_tag(ptr.provenance, &ecx.machine)
945 // Value does not matter, SB is disabled
949 Provenance::Concrete { alloc_id: ptr.provenance, sb: sb_tag },
950 Size::from_bytes(absolute_addr),
955 fn ptr_from_addr_cast(
956 ecx: &MiriInterpCx<'mir, 'tcx>,
958 ) -> InterpResult<'tcx, Pointer<Option<Self::Provenance>>> {
959 intptrcast::GlobalStateInner::ptr_from_addr_cast(ecx, addr)
963 ecx: &mut InterpCx<'mir, 'tcx, Self>,
964 ptr: Pointer<Self::Provenance>,
965 ) -> InterpResult<'tcx> {
966 match ptr.provenance {
967 Provenance::Concrete { alloc_id, sb } =>
968 intptrcast::GlobalStateInner::expose_ptr(ecx, alloc_id, sb),
969 Provenance::Wildcard => {
970 // No need to do anything for wildcard pointers as
971 // their provenances have already been previously exposed.
977 /// Convert a pointer with provenance into an allocation-offset pair,
978 /// or a `None` with an absolute address if that conversion is not possible.
980 ecx: &MiriInterpCx<'mir, 'tcx>,
981 ptr: Pointer<Self::Provenance>,
982 ) -> Option<(AllocId, Size, Self::ProvenanceExtra)> {
983 let rel = intptrcast::GlobalStateInner::abs_ptr_to_rel(ecx, ptr);
985 rel.map(|(alloc_id, size)| {
986 let sb = match ptr.provenance {
987 Provenance::Concrete { sb, .. } => ProvenanceExtra::Concrete(sb),
988 Provenance::Wildcard => ProvenanceExtra::Wildcard,
995 fn before_memory_read(
998 alloc_extra: &AllocExtra,
999 (alloc_id, prov_extra): (AllocId, Self::ProvenanceExtra),
1001 ) -> InterpResult<'tcx> {
1002 if let Some(data_race) = &alloc_extra.data_race {
1006 machine.data_race.as_ref().unwrap(),
1010 if let Some(stacked_borrows) = &alloc_extra.stacked_borrows {
1011 stacked_borrows.borrow_mut().before_memory_read(
1015 machine.stacked_borrows.as_ref().unwrap(),
1016 machine.current_span(),
1020 if let Some(weak_memory) = &alloc_extra.weak_memory {
1021 weak_memory.memory_accessed(range, machine.data_race.as_ref().unwrap());
1027 fn before_memory_write(
1030 alloc_extra: &mut AllocExtra,
1031 (alloc_id, prov_extra): (AllocId, Self::ProvenanceExtra),
1033 ) -> InterpResult<'tcx> {
1034 if let Some(data_race) = &mut alloc_extra.data_race {
1038 machine.data_race.as_mut().unwrap(),
1042 if let Some(stacked_borrows) = &mut alloc_extra.stacked_borrows {
1043 stacked_borrows.get_mut().before_memory_write(
1047 machine.stacked_borrows.as_ref().unwrap(),
1048 machine.current_span(),
1052 if let Some(weak_memory) = &alloc_extra.weak_memory {
1053 weak_memory.memory_accessed(range, machine.data_race.as_ref().unwrap());
1059 fn before_memory_deallocation(
1062 alloc_extra: &mut AllocExtra,
1063 (alloc_id, prove_extra): (AllocId, Self::ProvenanceExtra),
1065 ) -> InterpResult<'tcx> {
1066 if machine.tracked_alloc_ids.contains(&alloc_id) {
1067 machine.emit_diagnostic(NonHaltingDiagnostic::FreedAlloc(alloc_id));
1069 if let Some(data_race) = &mut alloc_extra.data_race {
1070 data_race.deallocate(
1073 machine.data_race.as_mut().unwrap(),
1077 if let Some(stacked_borrows) = &mut alloc_extra.stacked_borrows {
1078 stacked_borrows.get_mut().before_memory_deallocation(
1082 machine.stacked_borrows.as_ref().unwrap(),
1083 machine.current_span(),
1093 ecx: &mut InterpCx<'mir, 'tcx, Self>,
1094 kind: mir::RetagKind,
1095 place: &PlaceTy<'tcx, Provenance>,
1096 ) -> InterpResult<'tcx> {
1097 if ecx.machine.stacked_borrows.is_some() { ecx.retag(kind, place) } else { Ok(()) }
1101 fn init_frame_extra(
1102 ecx: &mut InterpCx<'mir, 'tcx, Self>,
1103 frame: Frame<'mir, 'tcx, Provenance>,
1104 ) -> InterpResult<'tcx, Frame<'mir, 'tcx, Provenance, FrameData<'tcx>>> {
1105 // Start recording our event before doing anything else
1106 let timing = if let Some(profiler) = ecx.machine.profiler.as_ref() {
1107 let fn_name = frame.instance.to_string();
1108 let entry = ecx.machine.string_cache.entry(fn_name.clone());
1109 let name = entry.or_insert_with(|| profiler.alloc_string(&*fn_name));
1111 Some(profiler.start_recording_interval_event_detached(
1113 measureme::EventId::from_label(*name),
1114 ecx.get_active_thread().to_u32(),
1120 let stacked_borrows = ecx.machine.stacked_borrows.as_ref();
1122 let extra = FrameData {
1123 stacked_borrows: stacked_borrows.map(|sb| sb.borrow_mut().new_frame(&ecx.machine)),
1127 Ok(frame.with_extra(extra))
1131 ecx: &'a InterpCx<'mir, 'tcx, Self>,
1132 ) -> &'a [Frame<'mir, 'tcx, Self::Provenance, Self::FrameExtra>] {
1133 ecx.active_thread_stack()
1137 ecx: &'a mut InterpCx<'mir, 'tcx, Self>,
1138 ) -> &'a mut Vec<Frame<'mir, 'tcx, Self::Provenance, Self::FrameExtra>> {
1139 ecx.active_thread_stack_mut()
1142 fn before_terminator(ecx: &mut InterpCx<'mir, 'tcx, Self>) -> InterpResult<'tcx> {
1143 ecx.machine.basic_block_count += 1u64; // a u64 that is only incremented by 1 will "never" overflow
1144 ecx.machine.since_gc += 1;
1145 // Possibly report our progress.
1146 if let Some(report_progress) = ecx.machine.report_progress {
1147 if ecx.machine.basic_block_count % u64::from(report_progress) == 0 {
1148 ecx.emit_diagnostic(NonHaltingDiagnostic::ProgressReport {
1149 block_count: ecx.machine.basic_block_count,
1154 // Search for SbTags to find all live pointers, then remove all other tags from borrow
1156 // When debug assertions are enabled, run the GC as often as possible so that any cases
1157 // where it mistakenly removes an important tag become visible.
1158 if ecx.machine.gc_interval > 0 && ecx.machine.since_gc >= ecx.machine.gc_interval {
1159 ecx.machine.since_gc = 0;
1160 ecx.garbage_collect_tags()?;
1163 // These are our preemption points.
1164 ecx.maybe_preempt_active_thread();
1166 // Make sure some time passes.
1167 ecx.machine.clock.tick();
1173 fn after_stack_push(ecx: &mut InterpCx<'mir, 'tcx, Self>) -> InterpResult<'tcx> {
1174 if ecx.machine.stacked_borrows.is_some() { ecx.retag_return_place() } else { Ok(()) }
1179 ecx: &mut InterpCx<'mir, 'tcx, Self>,
1180 mut frame: Frame<'mir, 'tcx, Provenance, FrameData<'tcx>>,
1182 ) -> InterpResult<'tcx, StackPopJump> {
1183 let timing = frame.extra.timing.take();
1184 if let Some(stacked_borrows) = &ecx.machine.stacked_borrows {
1185 stacked_borrows.borrow_mut().end_call(&frame.extra);
1187 let res = ecx.handle_stack_pop_unwind(frame.extra, unwinding);
1188 if let Some(profiler) = ecx.machine.profiler.as_ref() {
1189 profiler.finish_recording_interval_event(timing.unwrap());