#![feature( rustc_private, catch_expr, inclusive_range_fields, inclusive_range_methods, )] #![cfg_attr(feature = "cargo-clippy", allow(cast_lossless))] #[macro_use] extern crate log; // From rustc. #[macro_use] extern crate rustc; extern crate rustc_data_structures; extern crate rustc_mir; extern crate rustc_target; extern crate syntax; extern crate regex; #[macro_use] extern crate lazy_static; use rustc::ty::{self, TyCtxt}; use rustc::ty::layout::{TyLayout, LayoutOf, Size}; use rustc::ty::subst::Subst; use rustc::hir::def_id::DefId; use rustc::mir; use rustc_data_structures::fx::FxHasher; use syntax::ast::Mutability; use syntax::codemap::Span; use std::collections::{HashMap, BTreeMap}; use std::hash::{Hash, Hasher}; pub use rustc::mir::interpret::*; pub use rustc_mir::interpret::*; mod fn_call; mod operator; mod intrinsic; mod helpers; mod memory; mod tls; mod locks; mod range_map; mod validation; use fn_call::EvalContextExt as MissingFnsEvalContextExt; use operator::EvalContextExt as OperatorEvalContextExt; use intrinsic::EvalContextExt as IntrinsicEvalContextExt; use tls::EvalContextExt as TlsEvalContextExt; use locks::LockInfo; use locks::MemoryExt as LockMemoryExt; use validation::EvalContextExt as ValidationEvalContextExt; use range_map::RangeMap; use validation::{ValidationQuery, AbsPlace}; pub trait ScalarExt { fn null() -> Self; fn from_i32(i: i32) -> Self; fn from_u128(i: u128) -> Self; fn from_i128(i: i128) -> Self; fn from_usize(i: u64, ptr_size: Size) -> Self; fn from_isize(i: i64, ptr_size: Size) -> Self; fn from_f32(f: f32) -> Self; fn from_f64(f: f64) -> Self; fn to_usize<'a, 'mir, 'tcx>(self, ecx: &rustc_mir::interpret::EvalContext<'a, 'mir, 'tcx, Evaluator<'tcx>>) -> EvalResult<'static, u64>; fn is_null(self) -> EvalResult<'static, bool>; /// HACK: this function just extracts all bits if `defined != 0` /// Mainly used for args of C-functions and we should totally correctly fetch the size /// of their arguments fn to_bytes(self) -> EvalResult<'static, u128>; } impl ScalarExt for Scalar { fn null() -> Self { Scalar::Bits { bits: 0, defined: 128 } } fn from_i32(i: i32) -> Self { Scalar::Bits { bits: i as u32 as u128, defined: 32 } } fn from_u128(i: u128) -> Self { Scalar::Bits { bits: i, defined: 128 } } fn from_i128(i: i128) -> Self { Scalar::Bits { bits: i as u128, defined: 128 } } fn from_usize(i: u64, ptr_size: Size) -> Self { Scalar::Bits { bits: i as u128, defined: ptr_size.bits() as u8 } } fn from_isize(i: i64, ptr_size: Size) -> Self { Scalar::Bits { bits: i as i128 as u128, defined: ptr_size.bits() as u8 } } fn from_f32(f: f32) -> Self { Scalar::Bits { bits: f.to_bits() as u128, defined: 32 } } fn from_f64(f: f64) -> Self { Scalar::Bits { bits: f.to_bits() as u128, defined: 64 } } fn to_usize<'a, 'mir, 'tcx>(self, ecx: &rustc_mir::interpret::EvalContext<'a, 'mir, 'tcx, Evaluator<'tcx>>) -> EvalResult<'static, u64> { let b = self.to_bits(ecx.memory.pointer_size())?; assert_eq!(b as u64 as u128, b); Ok(b as u64) } fn is_null(self) -> EvalResult<'static, bool> { match self { Scalar::Bits { bits, defined } => { if defined > 0 { Ok(bits == 0) } else { err!(ReadUndefBytes) } } Scalar::Ptr(_) => Ok(false) } } fn to_bytes(self) -> EvalResult<'static, u128> { match self { Scalar::Bits { defined: 0, .. } => err!(ReadUndefBytes), Scalar::Bits { bits, .. } => Ok(bits), Scalar::Ptr(_) => err!(ReadPointerAsBytes), } } } pub fn create_ecx<'a, 'mir: 'a, 'tcx: 'mir>( tcx: TyCtxt<'a, 'tcx, 'tcx>, main_id: DefId, start_wrapper: Option, ) -> EvalResult<'tcx, (EvalContext<'a, 'mir, 'tcx, Evaluator<'tcx>>, Option)> { let mut ecx = EvalContext::new(tcx.at(syntax::codemap::DUMMY_SP), ty::ParamEnv::reveal_all(), Default::default(), Default::default()); let main_instance = ty::Instance::mono(ecx.tcx.tcx, main_id); let main_mir = ecx.load_mir(main_instance.def)?; let mut cleanup_ptr = None; // Scalar to be deallocated when we are done if !main_mir.return_ty().is_nil() || main_mir.arg_count != 0 { return err!(Unimplemented( "miri does not support main functions without `fn()` type signatures" .to_owned(), )); } if let Some(start_id) = start_wrapper { let main_ret_ty = ecx.tcx.fn_sig(main_id).output(); let main_ret_ty = main_ret_ty.no_late_bound_regions().unwrap(); let start_instance = ty::Instance::resolve( ecx.tcx.tcx, ty::ParamEnv::reveal_all(), start_id, ecx.tcx.mk_substs( ::std::iter::once(ty::subst::Kind::from(main_ret_ty))) ).unwrap(); let start_mir = ecx.load_mir(start_instance.def)?; if start_mir.arg_count != 3 { return err!(AbiViolation(format!( "'start' lang item should have three arguments, but has {}", start_mir.arg_count ))); } // Return value let size = ecx.tcx.data_layout.pointer_size; let align = ecx.tcx.data_layout.pointer_align; let ret_ptr = ecx.memory_mut().allocate(size, align, MemoryKind::Stack)?; cleanup_ptr = Some(ret_ptr); // Push our stack frame ecx.push_stack_frame( start_instance, start_mir.span, start_mir, Place::from_ptr(ret_ptr, align), StackPopCleanup::None, )?; let mut args = ecx.frame().mir.args_iter(); // First argument: pointer to main() let main_ptr = ecx.memory_mut().create_fn_alloc(main_instance); let dest = ecx.eval_place(&mir::Place::Local(args.next().unwrap()))?; let main_ty = main_instance.ty(ecx.tcx.tcx); let main_ptr_ty = ecx.tcx.mk_fn_ptr(main_ty.fn_sig(ecx.tcx.tcx)); ecx.write_value( ValTy { value: Value::Scalar(Scalar::Ptr(main_ptr)), ty: main_ptr_ty, }, dest, )?; // Second argument (argc): 1 let dest = ecx.eval_place(&mir::Place::Local(args.next().unwrap()))?; let ty = ecx.tcx.types.isize; ecx.write_scalar(dest, Scalar::from_u128(1), ty)?; // FIXME: extract main source file path // Third argument (argv): &[b"foo"] let dest = ecx.eval_place(&mir::Place::Local(args.next().unwrap()))?; let ty = ecx.tcx.mk_imm_ptr(ecx.tcx.mk_imm_ptr(ecx.tcx.types.u8)); let foo = ecx.memory.allocate_bytes(b"foo\0"); let ptr_size = ecx.memory.pointer_size(); let ptr_align = ecx.tcx.data_layout.pointer_align; let foo_ptr = ecx.memory.allocate(ptr_size, ptr_align, MemoryKind::Stack)?; ecx.memory.write_scalar(foo_ptr.into(), ptr_align, Scalar::Ptr(foo), ptr_size, false)?; ecx.memory.mark_static_initialized(foo_ptr.alloc_id, Mutability::Immutable)?; ecx.write_ptr(dest, foo_ptr.into(), ty)?; assert!(args.next().is_none(), "start lang item has more arguments than expected"); } else { ecx.push_stack_frame( main_instance, main_mir.span, main_mir, Place::from_scalar_ptr(Scalar::from_u128(1), ty::layout::Align::from_bytes(1, 1).unwrap()), StackPopCleanup::None, )?; // No arguments let mut args = ecx.frame().mir.args_iter(); assert!(args.next().is_none(), "main function must not have arguments"); } Ok((ecx, cleanup_ptr)) } pub fn eval_main<'a, 'tcx: 'a>( tcx: TyCtxt<'a, 'tcx, 'tcx>, main_id: DefId, start_wrapper: Option, ) { let (mut ecx, cleanup_ptr) = create_ecx(tcx, main_id, start_wrapper).expect("Couldn't create ecx"); let res: EvalResult = do catch { while ecx.step()? {} ecx.run_tls_dtors()?; if let Some(cleanup_ptr) = cleanup_ptr { ecx.memory_mut().deallocate( cleanup_ptr, None, MemoryKind::Stack, )?; } }; match res { Ok(()) => { let leaks = ecx.memory().leak_report(); if leaks != 0 { // TODO: Prevent leaks which aren't supposed to be there //tcx.sess.err("the evaluated program leaked memory"); } } Err(e) => { if let Some(frame) = ecx.stack().last() { let block = &frame.mir.basic_blocks()[frame.block]; let span = if frame.stmt < block.statements.len() { block.statements[frame.stmt].source_info.span } else { block.terminator().source_info.span }; let e = e.to_string(); let msg = format!("constant evaluation error: {}", e); let mut err = struct_error(ecx.tcx.tcx.at(span), msg.as_str()); let (frames, span) = ecx.generate_stacktrace(None); err.span_label(span, e); for FrameInfo { span, location, .. } in frames { err.span_note(span, &format!("inside call to `{}`", location)); } err.emit(); } else { ecx.tcx.sess.err(&e.to_string()); } for (i, frame) in ecx.stack().iter().enumerate() { trace!("-------------------"); trace!("Frame {}", i); trace!(" return: {:#?}", frame.return_place); for (i, local) in frame.locals.iter().enumerate() { if let Some(local) = local { trace!(" local {}: {:?}", i, local); } } } } } } #[derive(Clone, Default, PartialEq, Eq)] pub struct Evaluator<'tcx> { /// Environment variables set by `setenv` /// Miri does not expose env vars from the host to the emulated program pub(crate) env_vars: HashMap, Pointer>, /// Places that were suspended by the validation subsystem, and will be recovered later pub(crate) suspended: HashMap>>, } impl<'tcx> Hash for Evaluator<'tcx> { fn hash(&self, state: &mut H) { let Evaluator { env_vars, suspended: _, } = self; env_vars.iter() .map(|(env, ptr)| { let mut h = FxHasher::default(); env.hash(&mut h); ptr.hash(&mut h); h.finish() }) .fold(0u64, |acc, hash| acc.wrapping_add(hash)) .hash(state); } } pub type TlsKey = u128; #[derive(Copy, Clone, Debug, Hash, PartialEq, Eq)] pub struct TlsEntry<'tcx> { data: Scalar, // Will eventually become a map from thread IDs to `Scalar`s, if we ever support more than one thread. dtor: Option>, } #[derive(Clone, Default, PartialEq, Eq)] pub struct MemoryData<'tcx> { /// The Key to use for the next thread-local allocation. next_thread_local: TlsKey, /// pthreads-style thread-local storage. thread_local: BTreeMap>, /// Memory regions that are locked by some function /// /// Only mutable (static mut, heap, stack) allocations have an entry in this map. /// The entry is created when allocating the memory and deleted after deallocation. locks: HashMap>>, statics: HashMap, AllocId>, } impl<'tcx> Hash for MemoryData<'tcx> { fn hash(&self, state: &mut H) { let MemoryData { next_thread_local: _, thread_local, locks: _, statics: _, } = self; thread_local.hash(state); } } impl<'mir, 'tcx: 'mir> Machine<'mir, 'tcx> for Evaluator<'tcx> { type MemoryData = MemoryData<'tcx>; type MemoryKinds = memory::MemoryKind; /// Returns Ok() when the function was handled, fail otherwise fn eval_fn_call<'a>( ecx: &mut EvalContext<'a, 'mir, 'tcx, Self>, instance: ty::Instance<'tcx>, destination: Option<(Place, mir::BasicBlock)>, args: &[ValTy<'tcx>], span: Span, sig: ty::FnSig<'tcx>, ) -> EvalResult<'tcx, bool> { ecx.eval_fn_call(instance, destination, args, span, sig) } fn call_intrinsic<'a>( ecx: &mut rustc_mir::interpret::EvalContext<'a, 'mir, 'tcx, Self>, instance: ty::Instance<'tcx>, args: &[ValTy<'tcx>], dest: Place, dest_layout: TyLayout<'tcx>, target: mir::BasicBlock, ) -> EvalResult<'tcx> { ecx.call_intrinsic(instance, args, dest, dest_layout, target) } fn try_ptr_op<'a>( ecx: &rustc_mir::interpret::EvalContext<'a, 'mir, 'tcx, Self>, bin_op: mir::BinOp, left: Scalar, left_ty: ty::Ty<'tcx>, right: Scalar, right_ty: ty::Ty<'tcx>, ) -> EvalResult<'tcx, Option<(Scalar, bool)>> { ecx.ptr_op(bin_op, left, left_ty, right, right_ty) } fn mark_static_initialized<'a>( mem: &mut Memory<'a, 'mir, 'tcx, Self>, id: AllocId, _mutability: Mutability, ) -> EvalResult<'tcx, bool> { use memory::MemoryKind::*; match mem.get_alloc_kind(id) { // FIXME: This could be allowed, but not for env vars set during miri execution Some(MemoryKind::Machine(Env)) => err!(Unimplemented("statics can't refer to env vars".to_owned())), _ => Ok(false), // TODO: What does the bool mean? } } fn init_static<'a>( ecx: &mut EvalContext<'a, 'mir, 'tcx, Self>, cid: GlobalId<'tcx>, ) -> EvalResult<'tcx, AllocId> { // Step 1: If the static has already been evaluated return the cached version if let Some(alloc_id) = ecx.memory.data.statics.get(&cid) { return Ok(*alloc_id); } let tcx = ecx.tcx.tcx; // Step 2: Load mir let mut mir = ecx.load_mir(cid.instance.def)?; if let Some(index) = cid.promoted { mir = &mir.promoted[index]; } assert!(mir.arg_count == 0); // Step 3: Allocate storage let layout = ecx.layout_of(mir.return_ty().subst(tcx, cid.instance.substs))?; assert!(!layout.is_unsized()); let ptr = ecx.memory.allocate( layout.size, layout.align, MemoryKind::Stack, )?; // Step 4: Cache allocation id for recursive statics assert!(ecx.memory.data.statics.insert(cid, ptr.alloc_id).is_none()); // Step 5: Push stackframe to evaluate static let cleanup = StackPopCleanup::None; ecx.push_stack_frame( cid.instance, mir.span, mir, Place::from_ptr(ptr, layout.align), cleanup, )?; // Step 6: Step until static has been initialized let call_stackframe = ecx.stack().len(); while ecx.step()? && ecx.stack().len() >= call_stackframe { if ecx.stack().len() == call_stackframe { let frame = ecx.frame_mut(); let bb = &frame.mir.basic_blocks()[frame.block]; if bb.statements.len() == frame.stmt && !bb.is_cleanup { if let ::rustc::mir::TerminatorKind::Return = bb.terminator().kind { for (local, _local_decl) in mir.local_decls.iter_enumerated().skip(1) { // Don't deallocate locals, because the return value might reference them frame.storage_dead(local); } } } } } // TODO: Freeze immutable statics without copying them to the global static cache // Step 7: Return the alloc Ok(ptr.alloc_id) } fn box_alloc<'a>( ecx: &mut EvalContext<'a, 'mir, 'tcx, Self>, ty: ty::Ty<'tcx>, dest: Place, ) -> EvalResult<'tcx> { let layout = ecx.layout_of(ty)?; // Call the `exchange_malloc` lang item let malloc = ecx.tcx.lang_items().exchange_malloc_fn().unwrap(); let malloc = ty::Instance::mono(ecx.tcx.tcx, malloc); let malloc_mir = ecx.load_mir(malloc.def)?; ecx.push_stack_frame( malloc, malloc_mir.span, malloc_mir, dest, // Don't do anything when we are done. The statement() function will increment // the old stack frame's stmt counter to the next statement, which means that when // exchange_malloc returns, we go on evaluating exactly where we want to be. StackPopCleanup::None, )?; let mut args = ecx.frame().mir.args_iter(); let usize = ecx.tcx.types.usize; // First argument: size let dest = ecx.eval_place(&mir::Place::Local(args.next().unwrap()))?; ecx.write_value( ValTy { value: Value::Scalar(Scalar::from_u128(match layout.size.bytes() { 0 => 1 as u128, size => size as u128, })), ty: usize, }, dest, )?; // Second argument: align let dest = ecx.eval_place(&mir::Place::Local(args.next().unwrap()))?; ecx.write_value( ValTy { value: Value::Scalar(Scalar::from_u128(layout.align.abi().into())), ty: usize, }, dest, )?; // No more arguments assert!(args.next().is_none(), "exchange_malloc lang item has more arguments than expected"); Ok(()) } fn global_item_with_linkage<'a>( _ecx: &mut EvalContext<'a, 'mir, 'tcx, Self>, _instance: ty::Instance<'tcx>, _mutability: Mutability, ) -> EvalResult<'tcx> { panic!("remove this function from rustc"); } fn check_locks<'a>( mem: &Memory<'a, 'mir, 'tcx, Self>, ptr: Pointer, size: Size, access: AccessKind, ) -> EvalResult<'tcx> { mem.check_locks(ptr, size.bytes(), access) } fn add_lock<'a>( mem: &mut Memory<'a, 'mir, 'tcx, Self>, id: AllocId, ) { mem.data.locks.insert(id, RangeMap::new()); } fn free_lock<'a>( mem: &mut Memory<'a, 'mir, 'tcx, Self>, id: AllocId, len: u64, ) -> EvalResult<'tcx> { mem.data.locks .remove(&id) .expect("allocation has no corresponding locks") .check( Some(mem.cur_frame), 0, len, AccessKind::Read, ) .map_err(|lock| { EvalErrorKind::DeallocatedLockedMemory { //ptr, FIXME ptr: Pointer { alloc_id: AllocId(0), offset: Size::from_bytes(0), }, lock: lock.active, }.into() }) } fn end_region<'a>( ecx: &mut EvalContext<'a, 'mir, 'tcx, Self>, reg: Option<::rustc::middle::region::Scope>, ) -> EvalResult<'tcx> { ecx.end_region(reg) } fn validation_op<'a>( _ecx: &mut EvalContext<'a, 'mir, 'tcx, Self>, _op: ::rustc::mir::ValidationOp, _operand: &::rustc::mir::ValidationOperand<'tcx, ::rustc::mir::Place<'tcx>>, ) -> EvalResult<'tcx> { // FIXME: prevent this from ICEing //ecx.validation_op(op, operand) Ok(()) } }