use std::convert::{TryFrom, TryInto}; use std::mem; use std::num::NonZeroUsize; use std::time::Duration; use log::trace; use rustc_hir::def_id::{DefId, CRATE_DEF_INDEX}; use rustc_middle::mir; use rustc_middle::ty::{ self, layout::{LayoutOf, TyAndLayout}, List, TyCtxt, }; use rustc_span::Symbol; use rustc_target::abi::{Align, FieldsShape, Size, Variants}; use rustc_target::spec::abi::Abi; use rand::RngCore; use crate::*; impl<'mir, 'tcx: 'mir> EvalContextExt<'mir, 'tcx> for crate::MiriEvalContext<'mir, 'tcx> {} /// Gets an instance for a path. fn try_resolve_did<'mir, 'tcx>(tcx: TyCtxt<'tcx>, path: &[&str]) -> Option { tcx.crates(()).iter().find(|&&krate| tcx.crate_name(krate).as_str() == path[0]).and_then( |krate| { let krate = DefId { krate: *krate, index: CRATE_DEF_INDEX }; let mut items = tcx.module_children(krate); let mut path_it = path.iter().skip(1).peekable(); while let Some(segment) = path_it.next() { for item in mem::replace(&mut items, Default::default()).iter() { if item.ident.name.as_str() == *segment { if path_it.peek().is_none() { return Some(item.res.def_id()); } items = tcx.module_children(item.res.def_id()); break; } } } None }, ) } pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx> { /// Gets an instance for a path. fn resolve_path(&self, path: &[&str]) -> ty::Instance<'tcx> { let did = try_resolve_did(self.eval_context_ref().tcx.tcx, path) .unwrap_or_else(|| panic!("failed to find required Rust item: {:?}", path)); ty::Instance::mono(self.eval_context_ref().tcx.tcx, did) } /// Evaluates the scalar at the specified path. Returns Some(val) /// if the path could be resolved, and None otherwise fn eval_path_scalar(&mut self, path: &[&str]) -> InterpResult<'tcx, Scalar> { let this = self.eval_context_mut(); let instance = this.resolve_path(path); let cid = GlobalId { instance, promoted: None }; let const_val = this.eval_to_allocation(cid)?; let const_val = this.read_scalar(&const_val.into())?; return Ok(const_val.check_init()?); } /// Helper function to get a `libc` constant as a `Scalar`. fn eval_libc(&mut self, name: &str) -> InterpResult<'tcx, Scalar> { self.eval_context_mut().eval_path_scalar(&["libc", name]) } /// Helper function to get a `libc` constant as an `i32`. fn eval_libc_i32(&mut self, name: &str) -> InterpResult<'tcx, i32> { // TODO: Cache the result. self.eval_libc(name)?.to_i32() } /// Helper function to get a `windows` constant as a `Scalar`. fn eval_windows(&mut self, module: &str, name: &str) -> InterpResult<'tcx, Scalar> { self.eval_context_mut().eval_path_scalar(&["std", "sys", "windows", module, name]) } /// Helper function to get a `windows` constant as a `u64`. fn eval_windows_u64(&mut self, module: &str, name: &str) -> InterpResult<'tcx, u64> { // TODO: Cache the result. self.eval_windows(module, name)?.to_u64() } /// Helper function to get the `TyAndLayout` of a `libc` type fn libc_ty_layout(&mut self, name: &str) -> InterpResult<'tcx, TyAndLayout<'tcx>> { let this = self.eval_context_mut(); let ty = this.resolve_path(&["libc", name]).ty(*this.tcx, ty::ParamEnv::reveal_all()); this.layout_of(ty) } /// Helper function to get the `TyAndLayout` of a `windows` type fn windows_ty_layout(&mut self, name: &str) -> InterpResult<'tcx, TyAndLayout<'tcx>> { let this = self.eval_context_mut(); let ty = this .resolve_path(&["std", "sys", "windows", "c", name]) .ty(*this.tcx, ty::ParamEnv::reveal_all()); this.layout_of(ty) } /// Write a uint of the appropriate size to `dest`. fn write_uint(&mut self, i: impl Into, dest: &PlaceTy<'tcx, Tag>) -> InterpResult<'tcx> { self.eval_context_mut().write_scalar(Scalar::from_uint(i, dest.layout.size), dest) } /// Write an int of the appropriate size to `dest`. fn write_int(&mut self, i: impl Into, dest: &PlaceTy<'tcx, Tag>) -> InterpResult<'tcx> { self.eval_context_mut().write_scalar(Scalar::from_int(i, dest.layout.size), dest) } /// Write a 0 of the appropriate size to `dest`. fn write_null(&mut self, dest: &PlaceTy<'tcx, Tag>) -> InterpResult<'tcx> { self.write_int(0, dest) } /// Test if this pointer equals 0. fn ptr_is_null(&self, ptr: Pointer>) -> InterpResult<'tcx, bool> { let this = self.eval_context_ref(); let null = Scalar::null_ptr(this); this.ptr_eq(Scalar::from_maybe_pointer(ptr, this), null) } /// Get the `Place` for a local fn local_place(&mut self, local: mir::Local) -> InterpResult<'tcx, PlaceTy<'tcx, Tag>> { let this = self.eval_context_mut(); let place = mir::Place { local: local, projection: List::empty() }; this.eval_place(place) } /// Generate some random bytes, and write them to `dest`. fn gen_random(&mut self, ptr: Pointer>, len: u64) -> InterpResult<'tcx> { // Some programs pass in a null pointer and a length of 0 // to their platform's random-generation function (e.g. getrandom()) // on Linux. For compatibility with these programs, we don't perform // any additional checks - it's okay if the pointer is invalid, // since we wouldn't actually be writing to it. if len == 0 { return Ok(()); } let this = self.eval_context_mut(); let mut data = vec![0; usize::try_from(len).unwrap()]; if this.machine.communicate() { // Fill the buffer using the host's rng. getrandom::getrandom(&mut data) .map_err(|err| err_unsup_format!("host getrandom failed: {}", err))?; } else { let rng = this.memory.extra.rng.get_mut(); rng.fill_bytes(&mut data); } this.memory.write_bytes(ptr, data.iter().copied()) } /// Call a function: Push the stack frame and pass the arguments. /// For now, arguments must be scalars (so that the caller does not have to know the layout). fn call_function( &mut self, f: ty::Instance<'tcx>, caller_abi: Abi, args: &[Immediate], dest: Option<&PlaceTy<'tcx, Tag>>, stack_pop: StackPopCleanup, ) -> InterpResult<'tcx> { let this = self.eval_context_mut(); let param_env = ty::ParamEnv::reveal_all(); // in Miri this is always the param_env we use... and this.param_env is private. let callee_abi = f.ty(*this.tcx, param_env).fn_sig(*this.tcx).abi(); if this.machine.enforce_abi && callee_abi != caller_abi { throw_ub_format!( "calling a function with ABI {} using caller ABI {}", callee_abi.name(), caller_abi.name() ) } // Push frame. let mir = &*this.load_mir(f.def, None)?; this.push_stack_frame(f, mir, dest, stack_pop)?; // Initialize arguments. let mut callee_args = this.frame().body.args_iter(); for arg in args { let callee_arg = this.local_place( callee_args .next() .ok_or_else(|| err_ub_format!("callee has fewer arguments than expected"))?, )?; this.write_immediate(*arg, &callee_arg)?; } if callee_args.next().is_some() { throw_ub_format!("callee has more arguments than expected"); } Ok(()) } /// Visits the memory covered by `place`, sensitive to freezing: the 2nd parameter /// of `action` will be true if this is frozen, false if this is in an `UnsafeCell`. /// The range is relative to `place`. /// /// Assumes that the `place` has a proper pointer in it. fn visit_freeze_sensitive( &self, place: &MPlaceTy<'tcx, Tag>, size: Size, mut action: impl FnMut(AllocRange, bool) -> InterpResult<'tcx>, ) -> InterpResult<'tcx> { let this = self.eval_context_ref(); trace!("visit_frozen(place={:?}, size={:?})", *place, size); debug_assert_eq!( size, this.size_and_align_of_mplace(place)? .map(|(size, _)| size) .unwrap_or_else(|| place.layout.size) ); // Store how far we proceeded into the place so far. Everything to the left of // this offset has already been handled, in the sense that the frozen parts // have had `action` called on them. let ptr = place.ptr.into_pointer_or_addr().unwrap(); let start_offset = ptr.into_parts().1 as Size; // we just compare offsets, the abs. value never matters let mut cur_offset = start_offset; // Called when we detected an `UnsafeCell` at the given offset and size. // Calls `action` and advances `cur_ptr`. let mut unsafe_cell_action = |unsafe_cell_ptr: Pointer>, unsafe_cell_size: Size| { let unsafe_cell_ptr = unsafe_cell_ptr.into_pointer_or_addr().unwrap(); debug_assert_eq!(unsafe_cell_ptr.provenance, ptr.provenance); // We assume that we are given the fields in increasing offset order, // and nothing else changes. let unsafe_cell_offset = unsafe_cell_ptr.into_parts().1 as Size; // we just compare offsets, the abs. value never matters assert!(unsafe_cell_offset >= cur_offset); let frozen_size = unsafe_cell_offset - cur_offset; // Everything between the cur_ptr and this `UnsafeCell` is frozen. if frozen_size != Size::ZERO { action(alloc_range(cur_offset - start_offset, frozen_size), /*frozen*/ true)?; } cur_offset += frozen_size; // This `UnsafeCell` is NOT frozen. if unsafe_cell_size != Size::ZERO { action( alloc_range(cur_offset - start_offset, unsafe_cell_size), /*frozen*/ false, )?; } cur_offset += unsafe_cell_size; // Done Ok(()) }; // Run a visitor { let mut visitor = UnsafeCellVisitor { ecx: this, unsafe_cell_action: |place| { trace!("unsafe_cell_action on {:?}", place.ptr); // We need a size to go on. let unsafe_cell_size = this .size_and_align_of_mplace(&place)? .map(|(size, _)| size) // for extern types, just cover what we can .unwrap_or_else(|| place.layout.size); // Now handle this `UnsafeCell`, unless it is empty. if unsafe_cell_size != Size::ZERO { unsafe_cell_action(place.ptr, unsafe_cell_size) } else { Ok(()) } }, }; visitor.visit_value(place)?; } // The part between the end_ptr and the end of the place is also frozen. // So pretend there is a 0-sized `UnsafeCell` at the end. unsafe_cell_action(place.ptr.wrapping_offset(size, this), Size::ZERO)?; // Done! return Ok(()); /// Visiting the memory covered by a `MemPlace`, being aware of /// whether we are inside an `UnsafeCell` or not. struct UnsafeCellVisitor<'ecx, 'mir, 'tcx, F> where F: FnMut(&MPlaceTy<'tcx, Tag>) -> InterpResult<'tcx>, { ecx: &'ecx MiriEvalContext<'mir, 'tcx>, unsafe_cell_action: F, } impl<'ecx, 'mir, 'tcx: 'mir, F> ValueVisitor<'mir, 'tcx, Evaluator<'mir, 'tcx>> for UnsafeCellVisitor<'ecx, 'mir, 'tcx, F> where F: FnMut(&MPlaceTy<'tcx, Tag>) -> InterpResult<'tcx>, { type V = MPlaceTy<'tcx, Tag>; #[inline(always)] fn ecx(&self) -> &MiriEvalContext<'mir, 'tcx> { &self.ecx } // Hook to detect `UnsafeCell`. fn visit_value(&mut self, v: &MPlaceTy<'tcx, Tag>) -> InterpResult<'tcx> { trace!("UnsafeCellVisitor: {:?} {:?}", *v, v.layout.ty); let is_unsafe_cell = match v.layout.ty.kind() { ty::Adt(adt, _) => Some(adt.did()) == self.ecx.tcx.lang_items().unsafe_cell_type(), _ => false, }; if is_unsafe_cell { // We do not have to recurse further, this is an `UnsafeCell`. (self.unsafe_cell_action)(v) } else if self.ecx.type_is_freeze(v.layout.ty) { // This is `Freeze`, there cannot be an `UnsafeCell` Ok(()) } else if matches!(v.layout.fields, FieldsShape::Union(..)) { // A (non-frozen) union. We fall back to whatever the type says. (self.unsafe_cell_action)(v) } else { // We want to not actually read from memory for this visit. So, before // walking this value, we have to make sure it is not a // `Variants::Multiple`. match v.layout.variants { Variants::Multiple { .. } => { // A multi-variant enum, or generator, or so. // Treat this like a union: without reading from memory, // we cannot determine the variant we are in. Reading from // memory would be subject to Stacked Borrows rules, leading // to all sorts of "funny" recursion. // We only end up here if the type is *not* freeze, so we just call the // `UnsafeCell` action. (self.unsafe_cell_action)(v) } Variants::Single { .. } => { // Proceed further, try to find where exactly that `UnsafeCell` // is hiding. self.walk_value(v) } } } } // Make sure we visit aggregrates in increasing offset order. fn visit_aggregate( &mut self, place: &MPlaceTy<'tcx, Tag>, fields: impl Iterator>>, ) -> InterpResult<'tcx> { match place.layout.fields { FieldsShape::Array { .. } => { // For the array layout, we know the iterator will yield sorted elements so // we can avoid the allocation. self.walk_aggregate(place, fields) } FieldsShape::Arbitrary { .. } => { // Gather the subplaces and sort them before visiting. let mut places = fields.collect::>>>()?; // we just compare offsets, the abs. value never matters places.sort_by_key(|place| { place.ptr.into_pointer_or_addr().unwrap().into_parts().1 as Size }); self.walk_aggregate(place, places.into_iter().map(Ok)) } FieldsShape::Union { .. } | FieldsShape::Primitive => { // Uh, what? bug!("unions/primitives are not aggregates we should ever visit") } } } fn visit_union( &mut self, _v: &MPlaceTy<'tcx, Tag>, _fields: NonZeroUsize, ) -> InterpResult<'tcx> { bug!("we should have already handled unions in `visit_value`") } } } // Writes several `ImmTy`s contiguously into memory. This is useful when you have to pack // different values into a struct. fn write_packed_immediates( &mut self, place: &MPlaceTy<'tcx, Tag>, imms: &[ImmTy<'tcx, Tag>], ) -> InterpResult<'tcx> { let this = self.eval_context_mut(); let mut offset = Size::from_bytes(0); for &imm in imms { this.write_immediate( *imm, &place.offset(offset, MemPlaceMeta::None, imm.layout, &*this.tcx)?.into(), )?; offset += imm.layout.size; } Ok(()) } /// Helper function used inside the shims of foreign functions to check that isolation is /// disabled. It returns an error using the `name` of the foreign function if this is not the /// case. fn check_no_isolation(&self, name: &str) -> InterpResult<'tcx> { if !self.eval_context_ref().machine.communicate() { self.reject_in_isolation(name, RejectOpWith::Abort)?; } Ok(()) } /// Helper function used inside the shims of foreign functions which reject the op /// when isolation is enabled. It is used to print a warning/backtrace about the rejection. fn reject_in_isolation(&self, op_name: &str, reject_with: RejectOpWith) -> InterpResult<'tcx> { let this = self.eval_context_ref(); match reject_with { RejectOpWith::Abort => isolation_abort_error(op_name), RejectOpWith::WarningWithoutBacktrace => { this.tcx .sess .warn(&format!("{} was made to return an error due to isolation", op_name)); Ok(()) } RejectOpWith::Warning => { register_diagnostic(NonHaltingDiagnostic::RejectedIsolatedOp(op_name.to_string())); Ok(()) } RejectOpWith::NoWarning => Ok(()), // no warning } } /// Helper function used inside the shims of foreign functions to assert that the target OS /// is `target_os`. It panics showing a message with the `name` of the foreign function /// if this is not the case. fn assert_target_os(&self, target_os: &str, name: &str) { assert_eq!( self.eval_context_ref().tcx.sess.target.os, target_os, "`{}` is only available on the `{}` target OS", name, target_os, ) } /// Get last error variable as a place, lazily allocating thread-local storage for it if /// necessary. fn last_error_place(&mut self) -> InterpResult<'tcx, MPlaceTy<'tcx, Tag>> { let this = self.eval_context_mut(); if let Some(errno_place) = this.active_thread_ref().last_error { Ok(errno_place) } else { // Allocate new place, set initial value to 0. let errno_layout = this.machine.layouts.u32; let errno_place = this.allocate(errno_layout, MiriMemoryKind::Machine.into())?; this.write_scalar(Scalar::from_u32(0), &errno_place.into())?; this.active_thread_mut().last_error = Some(errno_place); Ok(errno_place) } } /// Sets the last error variable. fn set_last_error(&mut self, scalar: Scalar) -> InterpResult<'tcx> { let this = self.eval_context_mut(); let errno_place = this.last_error_place()?; this.write_scalar(scalar, &errno_place.into()) } /// Gets the last error variable. fn get_last_error(&mut self) -> InterpResult<'tcx, Scalar> { let this = self.eval_context_mut(); let errno_place = this.last_error_place()?; this.read_scalar(&errno_place.into())?.check_init() } /// Sets the last OS error using a `std::io::ErrorKind`. This function tries to produce the most /// similar OS error from the `std::io::ErrorKind` and sets it as the last OS error. fn set_last_error_from_io_error(&mut self, err_kind: std::io::ErrorKind) -> InterpResult<'tcx> { use std::io::ErrorKind::*; let this = self.eval_context_mut(); let target = &this.tcx.sess.target; let target_os = &target.os; let last_error = if target.families.contains(&"unix".to_owned()) { this.eval_libc(match err_kind { ConnectionRefused => "ECONNREFUSED", ConnectionReset => "ECONNRESET", PermissionDenied => "EPERM", BrokenPipe => "EPIPE", NotConnected => "ENOTCONN", ConnectionAborted => "ECONNABORTED", AddrNotAvailable => "EADDRNOTAVAIL", AddrInUse => "EADDRINUSE", NotFound => "ENOENT", Interrupted => "EINTR", InvalidInput => "EINVAL", TimedOut => "ETIMEDOUT", AlreadyExists => "EEXIST", WouldBlock => "EWOULDBLOCK", DirectoryNotEmpty => "ENOTEMPTY", _ => { throw_unsup_format!( "io error {:?} cannot be translated into a raw os error", err_kind ) } })? } else if target.families.contains(&"windows".to_owned()) { // FIXME: we have to finish implementing the Windows equivalent of this. this.eval_windows( "c", match err_kind { NotFound => "ERROR_FILE_NOT_FOUND", PermissionDenied => "ERROR_ACCESS_DENIED", _ => throw_unsup_format!( "io error {:?} cannot be translated into a raw os error", err_kind ), }, )? } else { throw_unsup_format!( "setting the last OS error from an io::Error is unsupported for {}.", target_os ) }; this.set_last_error(last_error) } /// Helper function that consumes an `std::io::Result` and returns an /// `InterpResult<'tcx,T>::Ok` instead. In case the result is an error, this function returns /// `Ok(-1)` and sets the last OS error accordingly. /// /// This function uses `T: From` instead of `i32` directly because some IO related /// functions return different integer types (like `read`, that returns an `i64`). fn try_unwrap_io_result>( &mut self, result: std::io::Result, ) -> InterpResult<'tcx, T> { match result { Ok(ok) => Ok(ok), Err(e) => { self.eval_context_mut().set_last_error_from_io_error(e.kind())?; Ok((-1).into()) } } } fn read_scalar_at_offset( &self, op: &OpTy<'tcx, Tag>, offset: u64, layout: TyAndLayout<'tcx>, ) -> InterpResult<'tcx, ScalarMaybeUninit> { let this = self.eval_context_ref(); let op_place = this.deref_operand(op)?; let offset = Size::from_bytes(offset); // Ensure that the following read at an offset is within bounds assert!(op_place.layout.size >= offset + layout.size); let value_place = op_place.offset(offset, MemPlaceMeta::None, layout, this)?; this.read_scalar(&value_place.into()) } fn write_scalar_at_offset( &mut self, op: &OpTy<'tcx, Tag>, offset: u64, value: impl Into>, layout: TyAndLayout<'tcx>, ) -> InterpResult<'tcx, ()> { let this = self.eval_context_mut(); let op_place = this.deref_operand(op)?; let offset = Size::from_bytes(offset); // Ensure that the following read at an offset is within bounds assert!(op_place.layout.size >= offset + layout.size); let value_place = op_place.offset(offset, MemPlaceMeta::None, layout, this)?; this.write_scalar(value, &value_place.into()) } /// Parse a `timespec` struct and return it as a `std::time::Duration`. It returns `None` /// if the value in the `timespec` struct is invalid. Some libc functions will return /// `EINVAL` in this case. fn read_timespec(&mut self, tp: &MPlaceTy<'tcx, Tag>) -> InterpResult<'tcx, Option> { let this = self.eval_context_mut(); let seconds_place = this.mplace_field(&tp, 0)?; let seconds_scalar = this.read_scalar(&seconds_place.into())?; let seconds = seconds_scalar.to_machine_isize(this)?; let nanoseconds_place = this.mplace_field(&tp, 1)?; let nanoseconds_scalar = this.read_scalar(&nanoseconds_place.into())?; let nanoseconds = nanoseconds_scalar.to_machine_isize(this)?; Ok(try { // tv_sec must be non-negative. let seconds: u64 = seconds.try_into().ok()?; // tv_nsec must be non-negative. let nanoseconds: u32 = nanoseconds.try_into().ok()?; if nanoseconds >= 1_000_000_000 { // tv_nsec must not be greater than 999,999,999. None? } Duration::new(seconds, nanoseconds) }) } fn read_c_str<'a>(&'a self, ptr: Pointer>) -> InterpResult<'tcx, &'a [u8]> where 'tcx: 'a, 'mir: 'a, { let this = self.eval_context_ref(); let size1 = Size::from_bytes(1); // Step 1: determine the length. let mut len = Size::ZERO; loop { // FIXME: We are re-getting the allocation each time around the loop. // Would be nice if we could somehow "extend" an existing AllocRange. let alloc = this.memory.get(ptr.offset(len, this)?.into(), size1, Align::ONE)?.unwrap(); // not a ZST, so we will get a result let byte = alloc.read_scalar(alloc_range(Size::ZERO, size1))?.to_u8()?; if byte == 0 { break; } else { len = len + size1; } } // Step 2: get the bytes. this.memory.read_bytes(ptr.into(), len) } fn read_wide_str(&self, mut ptr: Pointer>) -> InterpResult<'tcx, Vec> { let this = self.eval_context_ref(); let size2 = Size::from_bytes(2); let align2 = Align::from_bytes(2).unwrap(); let mut wchars = Vec::new(); loop { // FIXME: We are re-getting the allocation each time around the loop. // Would be nice if we could somehow "extend" an existing AllocRange. let alloc = this.memory.get(ptr.into(), size2, align2)?.unwrap(); // not a ZST, so we will get a result let wchar = alloc.read_scalar(alloc_range(Size::ZERO, size2))?.to_u16()?; if wchar == 0 { break; } else { wchars.push(wchar); ptr = ptr.offset(size2, this)?; } } Ok(wchars) } /// Check that the ABI is what we expect. fn check_abi<'a>(&self, abi: Abi, exp_abi: Abi) -> InterpResult<'a, ()> { if self.eval_context_ref().machine.enforce_abi && abi != exp_abi { throw_ub_format!( "calling a function with ABI {} using caller ABI {}", exp_abi.name(), abi.name() ) } Ok(()) } fn frame_in_std(&self) -> bool { let this = self.eval_context_ref(); this.tcx.lang_items().start_fn().map_or(false, |start_fn| { this.tcx.def_path(this.frame().instance.def_id()).krate == this.tcx.def_path(start_fn).krate }) } /// Handler that should be called when unsupported functionality is encountered. /// This function will either panic within the context of the emulated application /// or return an error in the Miri process context /// /// Return value of `Ok(bool)` indicates whether execution should continue. fn handle_unsupported>(&mut self, error_msg: S) -> InterpResult<'tcx, ()> { let this = self.eval_context_mut(); if this.machine.panic_on_unsupported { // message is slightly different here to make automated analysis easier let error_msg = format!("unsupported Miri functionality: {}", error_msg.as_ref()); this.start_panic(error_msg.as_ref(), StackPopUnwind::Skip)?; return Ok(()); } else { throw_unsup_format!("{}", error_msg.as_ref()); } } fn check_abi_and_shim_symbol_clash( &mut self, abi: Abi, exp_abi: Abi, link_name: Symbol, ) -> InterpResult<'tcx, ()> { self.check_abi(abi, exp_abi)?; if let Some((body, _)) = self.eval_context_mut().lookup_exported_symbol(link_name)? { throw_machine_stop!(TerminationInfo::SymbolShimClashing { link_name, span: body.span.data(), }) } Ok(()) } fn check_shim<'a, const N: usize>( &mut self, abi: Abi, exp_abi: Abi, link_name: Symbol, args: &'a [OpTy<'tcx, Tag>], ) -> InterpResult<'tcx, &'a [OpTy<'tcx, Tag>; N]> where &'a [OpTy<'tcx, Tag>; N]: TryFrom<&'a [OpTy<'tcx, Tag>]>, { self.check_abi_and_shim_symbol_clash(abi, exp_abi, link_name)?; check_arg_count(args) } /// Mark a machine allocation that was just created as immutable. fn mark_immutable(&mut self, mplace: &MemPlace) { let this = self.eval_context_mut(); this.memory .mark_immutable(mplace.ptr.into_pointer_or_addr().unwrap().provenance.alloc_id) .unwrap(); } } /// Check that the number of args is what we expect. pub fn check_arg_count<'a, 'tcx, const N: usize>( args: &'a [OpTy<'tcx, Tag>], ) -> InterpResult<'tcx, &'a [OpTy<'tcx, Tag>; N]> where &'a [OpTy<'tcx, Tag>; N]: TryFrom<&'a [OpTy<'tcx, Tag>]>, { if let Ok(ops) = args.try_into() { return Ok(ops); } throw_ub_format!("incorrect number of arguments: got {}, expected {}", args.len(), N) } pub fn isolation_abort_error(name: &str) -> InterpResult<'static> { throw_machine_stop!(TerminationInfo::UnsupportedInIsolation(format!( "{} not available when isolation is enabled", name, ))) } pub fn immty_from_int_checked<'tcx>( int: impl Into, layout: TyAndLayout<'tcx>, ) -> InterpResult<'tcx, ImmTy<'tcx, Tag>> { let int = int.into(); Ok(ImmTy::try_from_int(int, layout).ok_or_else(|| { err_unsup_format!("signed value {:#x} does not fit in {} bits", int, layout.size.bits()) })?) } pub fn immty_from_uint_checked<'tcx>( int: impl Into, layout: TyAndLayout<'tcx>, ) -> InterpResult<'tcx, ImmTy<'tcx, Tag>> { let int = int.into(); Ok(ImmTy::try_from_uint(int, layout).ok_or_else(|| { err_unsup_format!("unsigned value {:#x} does not fit in {} bits", int, layout.size.bits()) })?) } pub fn bool_to_simd_element(b: bool, size: Size) -> Scalar { // SIMD uses all-1 as pattern for "true" let val = if b { -1 } else { 0 }; Scalar::from_int(val, size) } pub fn simd_element_to_bool<'tcx>(elem: ImmTy<'tcx, Tag>) -> InterpResult<'tcx, bool> { let val = elem.to_scalar()?.to_int(elem.layout.size)?; Ok(match val { 0 => false, -1 => true, _ => throw_ub_format!("each element of a SIMD mask must be all-0-bits or all-1-bits"), }) }