13 use rustc::ty::{self, TyCtxt};
14 use rustc::ty::layout::{TyLayout, LayoutOf};
15 use rustc::hir::def_id::DefId;
19 use syntax::ast::Mutability;
20 use syntax::codemap::Span;
22 use std::collections::{HashMap, BTreeMap};
24 pub use rustc::mir::interpret::*;
33 use fn_call::EvalContextExt as MissingFnsEvalContextExt;
34 use operator::EvalContextExt as OperatorEvalContextExt;
35 use intrinsic::EvalContextExt as IntrinsicEvalContextExt;
36 use tls::EvalContextExt as TlsEvalContextExt;
38 pub fn eval_main<'a, 'tcx: 'a>(
39 tcx: TyCtxt<'a, 'tcx, 'tcx>,
41 start_wrapper: Option<DefId>,
42 limits: ResourceLimits,
44 fn run_main<'a, 'tcx: 'a>(
45 ecx: &mut rustc::mir::interpret::EvalContext<'a, 'tcx, Evaluator>,
47 start_wrapper: Option<DefId>,
48 ) -> EvalResult<'tcx> {
49 let main_instance = ty::Instance::mono(ecx.tcx, main_id);
50 let main_mir = ecx.load_mir(main_instance.def)?;
51 let mut cleanup_ptr = None; // Pointer to be deallocated when we are done
53 if !main_mir.return_ty().is_nil() || main_mir.arg_count != 0 {
54 return err!(Unimplemented(
55 "miri does not support main functions without `fn()` type signatures"
60 if let Some(start_id) = start_wrapper {
61 let start_instance = ty::Instance::mono(ecx.tcx, start_id);
62 let start_mir = ecx.load_mir(start_instance.def)?;
64 if start_mir.arg_count != 3 {
65 return err!(AbiViolation(format!(
66 "'start' lang item should have three arguments, but has {}",
72 let size = ecx.tcx.data_layout.pointer_size.bytes();
73 let align = ecx.tcx.data_layout.pointer_align.abi();
74 let ret_ptr = ecx.memory_mut().allocate(size, align, Some(MemoryKind::Stack))?;
75 cleanup_ptr = Some(ret_ptr);
77 // Push our stack frame
82 Place::from_ptr(ret_ptr),
83 StackPopCleanup::None,
86 let mut args = ecx.frame().mir.args_iter();
88 // First argument: pointer to main()
89 let main_ptr = ecx.memory_mut().create_fn_alloc(main_instance);
90 let dest = ecx.eval_place(&mir::Place::Local(args.next().unwrap()))?;
91 let main_ty = main_instance.def.def_ty(ecx.tcx);
92 let main_ptr_ty = ecx.tcx.mk_fn_ptr(main_ty.fn_sig(ecx.tcx));
95 value: Value::ByVal(PrimVal::Ptr(main_ptr)),
101 // Second argument (argc): 1
102 let dest = ecx.eval_place(&mir::Place::Local(args.next().unwrap()))?;
103 let ty = ecx.tcx.types.isize;
104 ecx.write_primval(dest, PrimVal::Bytes(1), ty)?;
106 // FIXME: extract main source file path
107 // Third argument (argv): &[b"foo"]
108 let dest = ecx.eval_place(&mir::Place::Local(args.next().unwrap()))?;
109 let ty = ecx.tcx.mk_imm_ptr(ecx.tcx.mk_imm_ptr(ecx.tcx.types.u8));
110 let foo = ecx.memory.allocate_cached(b"foo\0");
111 let ptr_size = ecx.memory.pointer_size();
112 let foo_ptr = ecx.memory.allocate(ptr_size * 1, ptr_size, None)?;
113 ecx.memory.write_primval(foo_ptr.into(), PrimVal::Ptr(foo.into()), ptr_size, false)?;
114 ecx.memory.mark_static_initalized(foo_ptr.alloc_id, Mutability::Immutable)?;
115 ecx.write_ptr(dest, foo_ptr.into(), ty)?;
117 assert!(args.next().is_none(), "start lang item has more arguments than expected");
119 ecx.push_stack_frame(
124 StackPopCleanup::None,
128 let mut args = ecx.frame().mir.args_iter();
129 assert!(args.next().is_none(), "main function must not have arguments");
133 ecx.run_tls_dtors()?;
134 if let Some(cleanup_ptr) = cleanup_ptr {
135 ecx.memory_mut().deallocate(
144 let mut ecx = EvalContext::new(tcx, ty::ParamEnv::empty(traits::Reveal::All), limits, Default::default(), Default::default());
145 match run_main(&mut ecx, main_id, start_wrapper) {
147 let leaks = ecx.memory().leak_report();
149 tcx.sess.err("the evaluated program leaked memory");
159 pub struct Evaluator {
160 /// Environment variables set by `setenv`
161 /// Miri does not expose env vars from the host to the emulated program
162 pub(crate) env_vars: HashMap<Vec<u8>, MemoryPointer>,
165 pub type TlsKey = usize;
167 #[derive(Copy, Clone, Debug)]
168 pub struct TlsEntry<'tcx> {
169 data: Pointer, // Will eventually become a map from thread IDs to `Pointer`s, if we ever support more than one thread.
170 dtor: Option<ty::Instance<'tcx>>,
174 pub struct MemoryData<'tcx> {
175 /// The Key to use for the next thread-local allocation.
176 next_thread_local: TlsKey,
178 /// pthreads-style thread-local storage.
179 thread_local: BTreeMap<TlsKey, TlsEntry<'tcx>>,
182 impl<'tcx> Machine<'tcx> for Evaluator {
183 type MemoryData = MemoryData<'tcx>;
184 type MemoryKinds = memory::MemoryKind;
186 /// Returns Ok() when the function was handled, fail otherwise
188 ecx: &mut EvalContext<'a, 'tcx, Self>,
189 instance: ty::Instance<'tcx>,
190 destination: Option<(Place, mir::BasicBlock)>,
191 args: &[ValTy<'tcx>],
193 sig: ty::FnSig<'tcx>,
194 ) -> EvalResult<'tcx, bool> {
195 ecx.eval_fn_call(instance, destination, args, span, sig)
198 fn call_intrinsic<'a>(
199 ecx: &mut rustc::mir::interpret::EvalContext<'a, 'tcx, Self>,
200 instance: ty::Instance<'tcx>,
201 args: &[ValTy<'tcx>],
203 dest_layout: TyLayout<'tcx>,
204 target: mir::BasicBlock,
205 ) -> EvalResult<'tcx> {
206 ecx.call_intrinsic(instance, args, dest, dest_layout, target)
210 ecx: &rustc::mir::interpret::EvalContext<'a, 'tcx, Self>,
213 left_ty: ty::Ty<'tcx>,
215 right_ty: ty::Ty<'tcx>,
216 ) -> EvalResult<'tcx, Option<(PrimVal, bool)>> {
217 ecx.ptr_op(bin_op, left, left_ty, right, right_ty)
220 fn mark_static_initialized(m: memory::MemoryKind) -> EvalResult<'tcx> {
221 use memory::MemoryKind::*;
223 // FIXME: This could be allowed, but not for env vars set during miri execution
224 Env => err!(Unimplemented("statics can't refer to env vars".to_owned())),
230 ecx: &mut EvalContext<'a, 'tcx, Self>,
233 ) -> EvalResult<'tcx> {
234 let layout = ecx.layout_of(ty)?;
236 // Call the `exchange_malloc` lang item
237 let malloc = ecx.tcx.lang_items().exchange_malloc_fn().unwrap();
238 let malloc = ty::Instance::mono(ecx.tcx, malloc);
239 let malloc_mir = ecx.load_mir(malloc.def)?;
240 ecx.push_stack_frame(
245 // Don't do anything when we are done. The statement() function will increment
246 // the old stack frame's stmt counter to the next statement, which means that when
247 // exchange_malloc returns, we go on evaluating exactly where we want to be.
248 StackPopCleanup::None,
251 let mut args = ecx.frame().mir.args_iter();
252 let usize = ecx.tcx.types.usize;
254 // First argument: size
255 let dest = ecx.eval_place(&mir::Place::Local(args.next().unwrap()))?;
258 value: Value::ByVal(PrimVal::Bytes(layout.size.bytes().into())),
264 // Second argument: align
265 let dest = ecx.eval_place(&mir::Place::Local(args.next().unwrap()))?;
268 value: Value::ByVal(PrimVal::Bytes(layout.align.abi().into())),
275 assert!(args.next().is_none(), "exchange_malloc lang item has more arguments than expected");
279 fn global_item_with_linkage<'a>(
280 ecx: &mut EvalContext<'a, 'tcx, Self>,
281 instance: ty::Instance<'tcx>,
282 mutability: Mutability,
283 ) -> EvalResult<'tcx> {
284 // FIXME: check that it's `#[linkage = "extern_weak"]`
285 trace!("Initializing an extern global with NULL");
286 let ptr_size = ecx.memory.pointer_size();
287 let ptr = ecx.memory.allocate(
292 ecx.memory.write_ptr_sized_unsigned(ptr, PrimVal::Bytes(0))?;
293 ecx.memory.mark_static_initalized(ptr.alloc_id, mutability)?;
294 ecx.tcx.interpret_interner.borrow_mut().cache(