1 use rustc::middle::const_val;
2 use rustc::hir::def_id::DefId;
3 use rustc::mir::mir_map::MirMap;
4 use rustc::mir::repr as mir;
5 use rustc::traits::{self, ProjectionMode};
6 use rustc::ty::fold::TypeFoldable;
7 use rustc::ty::layout::{self, Layout, Size};
8 use rustc::ty::subst::{self, Subst, Substs};
9 use rustc::ty::{self, Ty, TyCtxt};
10 use rustc::util::nodemap::DefIdMap;
11 use std::cell::RefCell;
17 use syntax::codemap::{self, DUMMY_SP};
19 use error::{EvalError, EvalResult};
20 use memory::{Memory, Pointer};
21 use primval::{self, PrimVal};
23 use std::collections::HashMap;
27 pub fn step<'fncx, 'a: 'fncx, 'tcx: 'a>(gecx: &'fncx mut EvalContext<'a, 'tcx>) -> EvalResult<bool> {
28 stepper::Stepper::new(gecx).step()
31 pub struct EvalContext<'a, 'tcx: 'a> {
32 /// The results of the type checker, from rustc.
33 tcx: TyCtxt<'a, 'tcx, 'tcx>,
35 /// A mapping from NodeIds to Mir, from rustc. Only contains MIR for crate-local items.
36 mir_map: &'a MirMap<'tcx>,
38 /// A local cache from DefIds to Mir for non-crate-local items.
39 mir_cache: RefCell<DefIdMap<Rc<mir::Mir<'tcx>>>>,
41 /// The virtual memory system.
44 /// Precomputed statics, constants and promoteds
45 statics: HashMap<ConstantId<'tcx>, Pointer>,
47 /// The virtual call stack.
48 stack: Vec<Frame<'a, 'tcx>>,
52 pub struct Frame<'a, 'tcx: 'a> {
53 /// The def_id of the current function
56 /// The span of the call site
57 pub span: codemap::Span,
59 /// type substitutions for the current function invocation
60 pub substs: &'tcx Substs<'tcx>,
62 /// The MIR for the function called on this frame.
63 pub mir: CachedMir<'a, 'tcx>,
65 /// The block that is currently executed (or will be executed after the above call stacks return)
66 pub next_block: mir::BasicBlock,
68 /// A pointer for writing the return value of the current call if it's not a diverging call.
69 pub return_ptr: Option<Pointer>,
71 /// The list of locals for the current function, stored in order as
72 /// `[arguments..., variables..., temporaries...]`. The variables begin at `self.var_offset`
73 /// and the temporaries at `self.temp_offset`.
74 pub locals: Vec<Pointer>,
76 /// The offset of the first variable in `self.locals`.
77 pub var_offset: usize,
79 /// The offset of the first temporary in `self.locals`.
80 pub temp_offset: usize,
82 /// The index of the currently evaluated statment
86 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
92 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
96 // TODO(solson): Vtable(memory::AllocId),
97 DowncastVariant(usize),
101 pub enum CachedMir<'mir, 'tcx: 'mir> {
102 Ref(&'mir mir::Mir<'tcx>),
103 Owned(Rc<mir::Mir<'tcx>>)
106 #[derive(Clone, Debug, Eq, PartialEq, Hash)]
107 /// Uniquely identifies a specific constant or static
108 struct ConstantId<'tcx> {
109 /// the def id of the constant/static or in case of promoteds, the def id of the function they belong to
111 /// In case of statics and constants this is `Substs::empty()`, so only promoteds and associated
112 /// constants actually have something useful here. We could special case statics and constants,
113 /// but that would only require more branching when working with constants, and not bring any
115 substs: &'tcx Substs<'tcx>,
119 #[derive(Clone, Debug, Eq, PartialEq, Hash)]
122 /// Statics, constants and associated constants
126 impl<'a, 'tcx> EvalContext<'a, 'tcx> {
127 pub fn new(tcx: TyCtxt<'a, 'tcx, 'tcx>, mir_map: &'a MirMap<'tcx>) -> Self {
131 mir_cache: RefCell::new(DefIdMap()),
132 memory: Memory::new(tcx.sess
136 .expect("Session::target::uint_type was usize")/8),
137 statics: HashMap::new(),
142 pub fn alloc_ret_ptr(&mut self, output_ty: ty::FnOutput<'tcx>, substs: &'tcx Substs<'tcx>) -> Option<Pointer> {
144 ty::FnConverging(ty) => {
145 let size = self.type_size(ty, substs);
146 Some(self.memory.allocate(size))
148 ty::FnDiverging => None,
152 pub fn memory(&self) -> &Memory {
156 pub fn stack(&self) -> &[Frame] {
160 // TODO(solson): Try making const_to_primval instead.
161 fn const_to_ptr(&mut self, const_val: &const_val::ConstVal) -> EvalResult<Pointer> {
162 use rustc::middle::const_val::ConstVal::*;
164 Float(_f) => unimplemented!(),
166 // TODO(solson): Check int constant type.
167 let ptr = self.memory.allocate(8);
168 self.memory.write_uint(ptr, int.to_u64_unchecked(), 8)?;
172 let psize = self.memory.pointer_size;
173 let static_ptr = self.memory.allocate(s.len());
174 let ptr = self.memory.allocate(psize * 2);
175 self.memory.write_bytes(static_ptr, s.as_bytes())?;
176 self.memory.write_ptr(ptr, static_ptr)?;
177 self.memory.write_usize(ptr.offset(psize as isize), s.len() as u64)?;
181 let psize = self.memory.pointer_size;
182 let static_ptr = self.memory.allocate(bs.len());
183 let ptr = self.memory.allocate(psize);
184 self.memory.write_bytes(static_ptr, bs)?;
185 self.memory.write_ptr(ptr, static_ptr)?;
189 let ptr = self.memory.allocate(1);
190 self.memory.write_bool(ptr, b)?;
193 Char(_c) => unimplemented!(),
194 Struct(_node_id) => unimplemented!(),
195 Tuple(_node_id) => unimplemented!(),
196 Function(_def_id) => unimplemented!(),
197 Array(_, _) => unimplemented!(),
198 Repeat(_, _) => unimplemented!(),
199 Dummy => unimplemented!(),
203 fn type_needs_drop(&self, ty: Ty<'tcx>) -> bool {
204 self.tcx.type_needs_drop_given_env(ty, &self.tcx.empty_parameter_environment())
207 fn type_is_sized(&self, ty: Ty<'tcx>) -> bool {
208 ty.is_sized(self.tcx, &self.tcx.empty_parameter_environment(), DUMMY_SP)
211 fn fulfill_obligation(&self, trait_ref: ty::PolyTraitRef<'tcx>) -> traits::Vtable<'tcx, ()> {
212 // Do the initial selection for the obligation. This yields the shallow result we are
213 // looking for -- that is, what specific impl.
214 self.tcx.normalizing_infer_ctxt(ProjectionMode::Any).enter(|infcx| {
215 let mut selcx = traits::SelectionContext::new(&infcx);
217 let obligation = traits::Obligation::new(
218 traits::ObligationCause::misc(DUMMY_SP, ast::DUMMY_NODE_ID),
219 trait_ref.to_poly_trait_predicate(),
221 let selection = selcx.select(&obligation).unwrap().unwrap();
223 // Currently, we use a fulfillment context to completely resolve all nested obligations.
224 // This is because they can inform the inference of the impl's type parameters.
225 let mut fulfill_cx = traits::FulfillmentContext::new();
226 let vtable = selection.map(|predicate| {
227 fulfill_cx.register_predicate_obligation(&infcx, predicate);
229 infcx.drain_fulfillment_cx_or_panic(DUMMY_SP, &mut fulfill_cx, &vtable)
233 /// Trait method, which has to be resolved to an impl method.
237 substs: &'tcx Substs<'tcx>
238 ) -> (DefId, &'tcx Substs<'tcx>) {
239 let method_item = self.tcx.impl_or_trait_item(def_id);
240 let trait_id = method_item.container().id();
241 let trait_ref = ty::Binder(substs.to_trait_ref(self.tcx, trait_id));
242 match self.fulfill_obligation(trait_ref) {
243 traits::VtableImpl(vtable_impl) => {
244 let impl_did = vtable_impl.impl_def_id;
245 let mname = self.tcx.item_name(def_id);
246 // Create a concatenated set of substitutions which includes those from the impl
247 // and those from the method:
248 let impl_substs = vtable_impl.substs.with_method_from(substs);
249 let substs = self.tcx.mk_substs(impl_substs);
250 let mth = get_impl_method(self.tcx, impl_did, substs, mname);
252 (mth.method.def_id, mth.substs)
255 traits::VtableClosure(vtable_closure) =>
256 (vtable_closure.closure_def_id, vtable_closure.substs.func_substs),
258 traits::VtableFnPointer(_fn_ty) => {
259 let _trait_closure_kind = self.tcx.lang_items.fn_trait_kind(trait_id).unwrap();
261 // let llfn = trans_fn_pointer_shim(ccx, trait_closure_kind, fn_ty);
263 // let method_ty = def_ty(tcx, def_id, substs);
264 // let fn_ptr_ty = match method_ty.sty {
265 // ty::TyFnDef(_, _, fty) => tcx.mk_ty(ty::TyFnPtr(fty)),
266 // _ => unreachable!("expected fn item type, found {}",
269 // Callee::ptr(immediate_rvalue(llfn, fn_ptr_ty))
272 traits::VtableObject(ref _data) => {
275 // data: Virtual(traits::get_vtable_index_of_object_method(
276 // tcx, data, def_id)),
277 // ty: def_ty(tcx, def_id, substs)
280 vtable => unreachable!("resolved vtable bad vtable {:?} in trans", vtable),
284 fn load_mir(&self, def_id: DefId) -> CachedMir<'a, 'tcx> {
285 match self.tcx.map.as_local_node_id(def_id) {
286 Some(node_id) => CachedMir::Ref(self.mir_map.map.get(&node_id).unwrap()),
288 let mut mir_cache = self.mir_cache.borrow_mut();
289 if let Some(mir) = mir_cache.get(&def_id) {
290 return CachedMir::Owned(mir.clone());
293 let cs = &self.tcx.sess.cstore;
294 let mir = cs.maybe_get_item_mir(self.tcx, def_id).unwrap_or_else(|| {
295 panic!("no mir for {:?}", def_id);
297 let cached = Rc::new(mir);
298 mir_cache.insert(def_id, cached.clone());
299 CachedMir::Owned(cached)
304 fn monomorphize(&self, ty: Ty<'tcx>, substs: &'tcx Substs<'tcx>) -> Ty<'tcx> {
305 let substituted = ty.subst(self.tcx, substs);
306 self.tcx.normalize_associated_type(&substituted)
309 fn type_size(&self, ty: Ty<'tcx>, substs: &'tcx Substs<'tcx>) -> usize {
310 self.type_layout(ty, substs).size(&self.tcx.data_layout).bytes() as usize
313 fn type_layout(&self, ty: Ty<'tcx>, substs: &'tcx Substs<'tcx>) -> &'tcx Layout {
314 // TODO(solson): Is this inefficient? Needs investigation.
315 let ty = self.monomorphize(ty, substs);
317 self.tcx.normalizing_infer_ctxt(ProjectionMode::Any).enter(|infcx| {
318 // TODO(solson): Report this error properly.
319 ty.layout(&infcx).unwrap()
323 pub fn push_stack_frame(&mut self, def_id: DefId, span: codemap::Span, mir: CachedMir<'a, 'tcx>, substs: &'tcx Substs<'tcx>,
324 return_ptr: Option<Pointer>)
326 let arg_tys = mir.arg_decls.iter().map(|a| a.ty);
327 let var_tys = mir.var_decls.iter().map(|v| v.ty);
328 let temp_tys = mir.temp_decls.iter().map(|t| t.ty);
330 let num_args = mir.arg_decls.len();
331 let num_vars = mir.var_decls.len();
333 ::log_settings::settings().indentation += 1;
335 let locals: Vec<Pointer> = arg_tys.chain(var_tys).chain(temp_tys).map(|ty| {
336 let size = self.type_size(ty, substs);
337 self.memory.allocate(size)
340 self.stack.push(Frame {
342 next_block: mir::START_BLOCK,
343 return_ptr: return_ptr,
345 var_offset: num_args,
346 temp_offset: num_args + num_vars,
354 fn pop_stack_frame(&mut self) {
355 ::log_settings::settings().indentation -= 1;
356 let _frame = self.stack.pop().expect("tried to pop a stack frame, but there were none");
357 // TODO(solson): Deallocate local variables.
360 fn eval_terminator(&mut self, terminator: &mir::Terminator<'tcx>)
362 use rustc::mir::repr::TerminatorKind::*;
363 match terminator.kind {
364 Return => self.pop_stack_frame(),
367 self.frame_mut().next_block = target;
370 If { ref cond, targets: (then_target, else_target) } => {
371 let cond_ptr = self.eval_operand(cond)?;
372 let cond_val = self.memory.read_bool(cond_ptr)?;
373 self.frame_mut().next_block = if cond_val { then_target } else { else_target };
376 SwitchInt { ref discr, ref values, ref targets, .. } => {
377 let discr_ptr = self.eval_lvalue(discr)?.to_ptr();
378 let discr_size = self
379 .type_layout(self.lvalue_ty(discr), self.substs())
380 .size(&self.tcx.data_layout)
382 let discr_val = self.memory.read_uint(discr_ptr, discr_size)?;
384 // Branch to the `otherwise` case by default, if no match is found.
385 let mut target_block = targets[targets.len() - 1];
387 for (index, val_const) in values.iter().enumerate() {
388 let ptr = self.const_to_ptr(val_const)?;
389 let val = self.memory.read_uint(ptr, discr_size)?;
390 if discr_val == val {
391 target_block = targets[index];
396 self.frame_mut().next_block = target_block;
399 Switch { ref discr, ref targets, adt_def } => {
400 let adt_ptr = self.eval_lvalue(discr)?.to_ptr();
401 let adt_ty = self.lvalue_ty(discr);
402 let discr_val = self.read_discriminant_value(adt_ptr, adt_ty)?;
403 let matching = adt_def.variants.iter()
404 .position(|v| discr_val == v.disr_val.to_u64_unchecked());
408 self.frame_mut().next_block = targets[i];
410 None => return Err(EvalError::InvalidDiscriminant),
414 Call { ref func, ref args, ref destination, .. } => {
415 let mut return_ptr = None;
416 if let Some((ref lv, target)) = *destination {
417 self.frame_mut().next_block = target;
418 return_ptr = Some(self.eval_lvalue(lv)?.to_ptr());
421 let func_ty = self.operand_ty(func);
423 ty::TyFnDef(def_id, substs, fn_ty) => {
424 use syntax::abi::Abi;
426 Abi::RustIntrinsic => {
427 let name = self.tcx.item_name(def_id).as_str();
428 match fn_ty.sig.0.output {
429 ty::FnConverging(ty) => {
430 let size = self.type_size(ty, self.substs());
431 let ret = return_ptr.unwrap();
432 self.call_intrinsic(&name, substs, args, ret, size)?
434 ty::FnDiverging => unimplemented!(),
439 match fn_ty.sig.0.output {
440 ty::FnConverging(ty) => {
441 let size = self.type_size(ty, self.substs());
442 self.call_c_abi(def_id, args, return_ptr.unwrap(), size)?
444 ty::FnDiverging => unimplemented!(),
448 Abi::Rust | Abi::RustCall => {
449 // TODO(solson): Adjust the first argument when calling a Fn or
450 // FnMut closure via FnOnce::call_once.
452 // Only trait methods can have a Self parameter.
453 let (resolved_def_id, resolved_substs) = if substs.self_ty().is_some() {
454 self.trait_method(def_id, substs)
459 let mut arg_srcs = Vec::new();
461 let src = self.eval_operand(arg)?;
462 let src_ty = self.operand_ty(arg);
463 arg_srcs.push((src, src_ty));
466 if fn_ty.abi == Abi::RustCall && !args.is_empty() {
468 let last_arg = args.last().unwrap();
469 let last = self.eval_operand(last_arg)?;
470 let last_ty = self.operand_ty(last_arg);
471 let last_layout = self.type_layout(last_ty, self.substs());
472 match (&last_ty.sty, last_layout) {
473 (&ty::TyTuple(fields),
474 &Layout::Univariant { ref variant, .. }) => {
475 let offsets = iter::once(0)
476 .chain(variant.offset_after_field.iter()
477 .map(|s| s.bytes()));
478 for (offset, ty) in offsets.zip(fields) {
479 let src = last.offset(offset as isize);
480 arg_srcs.push((src, ty));
483 ty => panic!("expected tuple as last argument in function with 'rust-call' ABI, got {:?}", ty),
487 let mir = self.load_mir(resolved_def_id);
488 self.push_stack_frame(def_id, terminator.span, mir, resolved_substs, return_ptr);
490 for (i, (src, src_ty)) in arg_srcs.into_iter().enumerate() {
491 let dest = self.frame().locals[i];
492 self.move_(src, dest, src_ty)?;
496 abi => return Err(EvalError::Unimplemented(format!("can't handle function with {:?} ABI", abi))),
500 _ => return Err(EvalError::Unimplemented(format!("can't handle callee of type {:?}", func_ty))),
504 Drop { ref value, target, .. } => {
505 let ptr = self.eval_lvalue(value)?.to_ptr();
506 let ty = self.lvalue_ty(value);
508 self.frame_mut().next_block = target;
511 Resume => unimplemented!(),
517 fn drop(&mut self, ptr: Pointer, ty: Ty<'tcx>) -> EvalResult<()> {
518 if !self.type_needs_drop(ty) {
519 debug!("no need to drop {:?}", ty);
522 trace!("-need to drop {:?}", ty);
524 // TODO(solson): Call user-defined Drop::drop impls.
527 ty::TyBox(contents_ty) => {
528 match self.memory.read_ptr(ptr) {
529 Ok(contents_ptr) => {
530 self.drop(contents_ptr, contents_ty)?;
531 trace!("-deallocating box");
532 self.memory.deallocate(contents_ptr)?;
534 Err(EvalError::ReadBytesAsPointer) => {
535 let size = self.memory.pointer_size;
536 let possible_drop_fill = self.memory.read_bytes(ptr, size)?;
537 if possible_drop_fill.iter().all(|&b| b == mem::POST_DROP_U8) {
540 return Err(EvalError::ReadBytesAsPointer);
543 Err(e) => return Err(e),
547 // TODO(solson): Implement drop for other relevant types (e.g. aggregates).
552 // FIXME(solson): Trait objects (with no static size) probably get filled, too.
553 let size = self.type_size(ty, self.substs());
554 self.memory.drop_fill(ptr, size)?;
559 fn read_discriminant_value(&self, adt_ptr: Pointer, adt_ty: Ty<'tcx>) -> EvalResult<u64> {
560 use rustc::ty::layout::Layout::*;
561 let adt_layout = self.type_layout(adt_ty, self.substs());
563 let discr_val = match *adt_layout {
564 General { discr, .. } | CEnum { discr, .. } => {
565 let discr_size = discr.size().bytes();
566 self.memory.read_uint(adt_ptr, discr_size as usize)?
569 RawNullablePointer { nndiscr, .. } => {
570 self.read_nonnull_discriminant_value(adt_ptr, nndiscr)?
573 StructWrappedNullablePointer { nndiscr, ref discrfield, .. } => {
574 let offset = self.nonnull_offset(adt_ty, nndiscr, discrfield)?;
575 let nonnull = adt_ptr.offset(offset.bytes() as isize);
576 self.read_nonnull_discriminant_value(nonnull, nndiscr)?
579 // The discriminant_value intrinsic returns 0 for non-sum types.
580 Array { .. } | FatPointer { .. } | Scalar { .. } | Univariant { .. } |
587 fn read_nonnull_discriminant_value(&self, ptr: Pointer, nndiscr: u64) -> EvalResult<u64> {
588 let not_null = match self.memory.read_usize(ptr) {
590 Ok(_) | Err(EvalError::ReadPointerAsBytes) => true,
591 Err(e) => return Err(e),
593 assert!(nndiscr == 0 || nndiscr == 1);
594 Ok(if not_null { nndiscr } else { 1 - nndiscr })
600 substs: &'tcx Substs<'tcx>,
601 args: &[mir::Operand<'tcx>],
604 ) -> EvalResult<()> {
605 let args_res: EvalResult<Vec<Pointer>> = args.iter()
606 .map(|arg| self.eval_operand(arg))
608 let args = args_res?;
611 // FIXME(solson): Handle different integer types correctly.
612 "add_with_overflow" => {
613 let ty = *substs.types.get(subst::FnSpace, 0);
614 let size = self.type_size(ty, self.substs());
615 let left = self.memory.read_int(args[0], size)?;
616 let right = self.memory.read_int(args[1], size)?;
617 let (n, overflowed) = unsafe {
618 ::std::intrinsics::add_with_overflow::<i64>(left, right)
620 self.memory.write_int(dest, n, size)?;
621 self.memory.write_bool(dest.offset(size as isize), overflowed)?;
626 "copy_nonoverlapping" => {
627 let elem_ty = *substs.types.get(subst::FnSpace, 0);
628 let elem_size = self.type_size(elem_ty, self.substs());
629 let src = self.memory.read_ptr(args[0])?;
630 let dest = self.memory.read_ptr(args[1])?;
631 let count = self.memory.read_isize(args[2])?;
632 self.memory.copy(src, dest, count as usize * elem_size)?;
635 "discriminant_value" => {
636 let ty = *substs.types.get(subst::FnSpace, 0);
637 let adt_ptr = self.memory.read_ptr(args[0])?;
638 let discr_val = self.read_discriminant_value(adt_ptr, ty)?;
639 self.memory.write_uint(dest, discr_val, dest_size)?;
643 let arg_ty = *substs.types.get(subst::FnSpace, 0);
644 let arg_size = self.type_size(arg_ty, self.substs());
645 self.memory.drop_fill(args[0], arg_size)?;
648 "init" => self.memory.write_repeat(dest, 0, dest_size)?,
651 self.memory.write_int(dest, 1, dest_size)?;
655 let ty = *substs.types.get(subst::FnSpace, 0);
656 let ptr = self.memory.read_ptr(args[0])?;
657 self.move_(args[1], ptr, ty)?;
660 // FIXME(solson): Handle different integer types correctly.
661 "mul_with_overflow" => {
662 let ty = *substs.types.get(subst::FnSpace, 0);
663 let size = self.type_size(ty, self.substs());
664 let left = self.memory.read_int(args[0], size)?;
665 let right = self.memory.read_int(args[1], size)?;
666 let (n, overflowed) = unsafe {
667 ::std::intrinsics::mul_with_overflow::<i64>(left, right)
669 self.memory.write_int(dest, n, size)?;
670 self.memory.write_bool(dest.offset(size as isize), overflowed)?;
674 let pointee_ty = *substs.types.get(subst::FnSpace, 0);
675 let pointee_size = self.type_size(pointee_ty, self.substs()) as isize;
676 let ptr_arg = args[0];
677 let offset = self.memory.read_isize(args[1])?;
679 match self.memory.read_ptr(ptr_arg) {
681 let result_ptr = ptr.offset(offset as isize * pointee_size);
682 self.memory.write_ptr(dest, result_ptr)?;
684 Err(EvalError::ReadBytesAsPointer) => {
685 let addr = self.memory.read_isize(ptr_arg)?;
686 let result_addr = addr + offset * pointee_size as i64;
687 self.memory.write_isize(dest, result_addr)?;
689 Err(e) => return Err(e),
693 // FIXME(solson): Handle different integer types correctly. Use primvals?
694 "overflowing_sub" => {
695 let ty = *substs.types.get(subst::FnSpace, 0);
696 let size = self.type_size(ty, self.substs());
697 let left = self.memory.read_int(args[0], size)?;
698 let right = self.memory.read_int(args[1], size)?;
699 let n = left.wrapping_sub(right);
700 self.memory.write_int(dest, n, size)?;
704 let ty = *substs.types.get(subst::FnSpace, 0);
705 let size = self.type_size(ty, self.substs()) as u64;
706 self.memory.write_uint(dest, size, dest_size)?;
710 let ty = *substs.types.get(subst::FnSpace, 0);
711 if self.type_is_sized(ty) {
712 let size = self.type_size(ty, self.substs()) as u64;
713 self.memory.write_uint(dest, size, dest_size)?;
716 ty::TySlice(_) | ty::TyStr => {
717 let elem_ty = ty.sequence_element_type(self.tcx);
718 let elem_size = self.type_size(elem_ty, self.substs()) as u64;
719 let ptr_size = self.memory.pointer_size as isize;
720 let n = self.memory.read_usize(args[0].offset(ptr_size))?;
721 self.memory.write_uint(dest, n * elem_size, dest_size)?;
724 _ => return Err(EvalError::Unimplemented(format!("unimplemented: size_of_val::<{:?}>", ty))),
730 let ty = *substs.types.get(subst::FnSpace, 0);
731 self.move_(args[0], dest, ty)?;
733 "uninit" => self.memory.mark_definedness(dest, dest_size, false)?,
735 name => return Err(EvalError::Unimplemented(format!("unimplemented intrinsic: {}", name))),
738 // Since we pushed no stack frame, the main loop will act
739 // as if the call just completed and it's returning to the
747 args: &[mir::Operand<'tcx>],
750 ) -> EvalResult<()> {
751 let name = self.tcx.item_name(def_id);
752 let attrs = self.tcx.get_attrs(def_id);
753 let link_name = match attr::first_attr_value_str_by_name(&attrs, "link_name") {
754 Some(ln) => ln.clone(),
755 None => name.as_str(),
758 let args_res: EvalResult<Vec<Pointer>> = args.iter()
759 .map(|arg| self.eval_operand(arg))
761 let args = args_res?;
763 match &link_name[..] {
764 "__rust_allocate" => {
765 let size = self.memory.read_usize(args[0])?;
766 let ptr = self.memory.allocate(size as usize);
767 self.memory.write_ptr(dest, ptr)?;
770 "__rust_reallocate" => {
771 let ptr = self.memory.read_ptr(args[0])?;
772 let size = self.memory.read_usize(args[2])?;
773 self.memory.reallocate(ptr, size as usize)?;
774 self.memory.write_ptr(dest, ptr)?;
778 let left = self.memory.read_ptr(args[0])?;
779 let right = self.memory.read_ptr(args[1])?;
780 let n = self.memory.read_usize(args[2])? as usize;
783 let left_bytes = self.memory.read_bytes(left, n)?;
784 let right_bytes = self.memory.read_bytes(right, n)?;
786 use std::cmp::Ordering::*;
787 match left_bytes.cmp(right_bytes) {
794 self.memory.write_int(dest, result, dest_size)?;
797 _ => return Err(EvalError::Unimplemented(format!("can't call C ABI function: {}", link_name))),
800 // Since we pushed no stack frame, the main loop will act
801 // as if the call just completed and it's returning to the
806 fn assign_fields<I: IntoIterator<Item = u64>>(
810 operands: &[mir::Operand<'tcx>],
811 ) -> EvalResult<()> {
812 for (offset, operand) in offsets.into_iter().zip(operands) {
813 let src = self.eval_operand(operand)?;
814 let src_ty = self.operand_ty(operand);
815 let field_dest = dest.offset(offset as isize);
816 self.move_(src, field_dest, src_ty)?;
821 fn eval_assignment(&mut self, lvalue: &mir::Lvalue<'tcx>, rvalue: &mir::Rvalue<'tcx>)
824 let dest = self.eval_lvalue(lvalue)?.to_ptr();
825 let dest_ty = self.lvalue_ty(lvalue);
826 let dest_layout = self.type_layout(dest_ty, self.substs());
828 use rustc::mir::repr::Rvalue::*;
830 Use(ref operand) => {
831 let src = self.eval_operand(operand)?;
832 self.move_(src, dest, dest_ty)?;
835 BinaryOp(bin_op, ref left, ref right) => {
836 let left_ptr = self.eval_operand(left)?;
837 let left_ty = self.operand_ty(left);
838 let left_val = self.read_primval(left_ptr, left_ty)?;
840 let right_ptr = self.eval_operand(right)?;
841 let right_ty = self.operand_ty(right);
842 let right_val = self.read_primval(right_ptr, right_ty)?;
844 let val = primval::binary_op(bin_op, left_val, right_val)?;
845 self.memory.write_primval(dest, val)?;
848 UnaryOp(un_op, ref operand) => {
849 let ptr = self.eval_operand(operand)?;
850 let ty = self.operand_ty(operand);
851 let val = self.read_primval(ptr, ty)?;
852 self.memory.write_primval(dest, primval::unary_op(un_op, val)?)?;
855 Aggregate(ref kind, ref operands) => {
856 use rustc::ty::layout::Layout::*;
858 Univariant { ref variant, .. } => {
859 let offsets = iter::once(0)
860 .chain(variant.offset_after_field.iter().map(|s| s.bytes()));
861 self.assign_fields(dest, offsets, operands)?;
865 let elem_size = match dest_ty.sty {
866 ty::TyArray(elem_ty, _) => self.type_size(elem_ty, self.substs()) as u64,
867 _ => panic!("tried to assign {:?} to non-array type {:?}",
870 let offsets = (0..).map(|i| i * elem_size);
871 self.assign_fields(dest, offsets, operands)?;
874 General { discr, ref variants, .. } => {
875 if let mir::AggregateKind::Adt(adt_def, variant, _) = *kind {
876 let discr_val = adt_def.variants[variant].disr_val.to_u64_unchecked();
877 let discr_size = discr.size().bytes() as usize;
878 self.memory.write_uint(dest, discr_val, discr_size)?;
880 let offsets = variants[variant].offset_after_field.iter()
882 self.assign_fields(dest, offsets, operands)?;
884 panic!("tried to assign {:?} to Layout::General", kind);
888 RawNullablePointer { nndiscr, .. } => {
889 if let mir::AggregateKind::Adt(_, variant, _) = *kind {
890 if nndiscr == variant as u64 {
891 assert_eq!(operands.len(), 1);
892 let operand = &operands[0];
893 let src = self.eval_operand(operand)?;
894 let src_ty = self.operand_ty(operand);
895 self.move_(src, dest, src_ty)?;
897 assert_eq!(operands.len(), 0);
898 self.memory.write_isize(dest, 0)?;
901 panic!("tried to assign {:?} to Layout::RawNullablePointer", kind);
905 StructWrappedNullablePointer { nndiscr, ref nonnull, ref discrfield } => {
906 if let mir::AggregateKind::Adt(_, variant, _) = *kind {
907 if nndiscr == variant as u64 {
908 let offsets = iter::once(0)
909 .chain(nonnull.offset_after_field.iter().map(|s| s.bytes()));
910 try!(self.assign_fields(dest, offsets, operands));
912 assert_eq!(operands.len(), 0);
913 let offset = self.nonnull_offset(dest_ty, nndiscr, discrfield)?;
914 let dest = dest.offset(offset.bytes() as isize);
915 try!(self.memory.write_isize(dest, 0));
918 panic!("tried to assign {:?} to Layout::RawNullablePointer", kind);
922 CEnum { discr, signed, .. } => {
923 assert_eq!(operands.len(), 0);
924 if let mir::AggregateKind::Adt(adt_def, variant, _) = *kind {
925 let val = adt_def.variants[variant].disr_val.to_u64_unchecked();
926 let size = discr.size().bytes() as usize;
929 self.memory.write_int(dest, val as i64, size)?;
931 self.memory.write_uint(dest, val, size)?;
934 panic!("tried to assign {:?} to Layout::CEnum", kind);
938 _ => return Err(EvalError::Unimplemented(format!("can't handle destination layout {:?} when assigning {:?}", dest_layout, kind))),
942 Repeat(ref operand, _) => {
943 let (elem_size, length) = match dest_ty.sty {
944 ty::TyArray(elem_ty, n) => (self.type_size(elem_ty, self.substs()), n),
945 _ => panic!("tried to assign array-repeat to non-array type {:?}", dest_ty),
948 let src = self.eval_operand(operand)?;
950 let elem_dest = dest.offset((i * elem_size) as isize);
951 self.memory.copy(src, elem_dest, elem_size)?;
956 let src = self.eval_lvalue(lvalue)?;
957 let ty = self.lvalue_ty(lvalue);
958 let len = match ty.sty {
959 ty::TyArray(_, n) => n as u64,
960 ty::TySlice(_) => if let LvalueExtra::Length(n) = src.extra {
963 panic!("Rvalue::Len of a slice given non-slice pointer: {:?}", src);
965 _ => panic!("Rvalue::Len expected array or slice, got {:?}", ty),
967 self.memory.write_usize(dest, len)?;
970 Ref(_, _, ref lvalue) => {
971 let lv = self.eval_lvalue(lvalue)?;
972 self.memory.write_ptr(dest, lv.ptr)?;
974 LvalueExtra::None => {},
975 LvalueExtra::Length(len) => {
976 let len_ptr = dest.offset(self.memory.pointer_size as isize);
977 self.memory.write_usize(len_ptr, len)?;
979 LvalueExtra::DowncastVariant(..) =>
980 panic!("attempted to take a reference to an enum downcast lvalue"),
985 let size = self.type_size(ty, self.substs());
986 let ptr = self.memory.allocate(size);
987 self.memory.write_ptr(dest, ptr)?;
990 Cast(kind, ref operand, dest_ty) => {
991 let src = self.eval_operand(operand)?;
992 let src_ty = self.operand_ty(operand);
994 use rustc::mir::repr::CastKind::*;
997 self.move_(src, dest, src_ty)?;
998 let src_pointee_ty = pointee_type(src_ty).unwrap();
999 let dest_pointee_ty = pointee_type(dest_ty).unwrap();
1001 match (&src_pointee_ty.sty, &dest_pointee_ty.sty) {
1002 (&ty::TyArray(_, length), &ty::TySlice(_)) => {
1003 let len_ptr = dest.offset(self.memory.pointer_size as isize);
1004 self.memory.write_usize(len_ptr, length as u64)?;
1007 _ => return Err(EvalError::Unimplemented(format!("can't handle cast: {:?}", rvalue))),
1012 // FIXME(solson): Wrong for almost everything.
1013 let size = dest_layout.size(&self.tcx.data_layout).bytes() as usize;
1014 self.memory.copy(src, dest, size)?;
1017 _ => return Err(EvalError::Unimplemented(format!("can't handle cast: {:?}", rvalue))),
1021 Slice { .. } => unimplemented!(),
1022 InlineAsm { .. } => unimplemented!(),
1028 fn nonnull_offset(&self, ty: Ty<'tcx>, nndiscr: u64, discrfield: &[u32]) -> EvalResult<Size> {
1029 // Skip the constant 0 at the start meant for LLVM GEP.
1030 let mut path = discrfield.iter().skip(1).map(|&i| i as usize);
1032 // Handle the field index for the outer non-null variant.
1033 let inner_ty = match ty.sty {
1034 ty::TyEnum(adt_def, substs) => {
1035 let variant = &adt_def.variants[nndiscr as usize];
1036 let index = path.next().unwrap();
1037 let field = &variant.fields[index];
1038 field.ty(self.tcx, substs)
1041 "non-enum for StructWrappedNullablePointer: {}",
1046 self.field_path_offset(inner_ty, path)
1049 fn field_path_offset<I: Iterator<Item = usize>>(&self, mut ty: Ty<'tcx>, path: I) -> EvalResult<Size> {
1050 let mut offset = Size::from_bytes(0);
1052 // Skip the initial 0 intended for LLVM GEP.
1053 for field_index in path {
1054 let field_offset = self.get_field_offset(ty, field_index)?;
1055 ty = self.get_field_ty(ty, field_index)?;
1056 offset = offset.checked_add(field_offset, &self.tcx.data_layout).unwrap();
1062 fn get_field_ty(&self, ty: Ty<'tcx>, field_index: usize) -> EvalResult<Ty<'tcx>> {
1064 ty::TyStruct(adt_def, substs) => {
1065 Ok(adt_def.struct_variant().fields[field_index].ty(self.tcx, substs))
1068 ty::TyRef(_, ty::TypeAndMut { ty, .. }) |
1069 ty::TyRawPtr(ty::TypeAndMut { ty, .. }) |
1071 assert_eq!(field_index, 0);
1074 _ => Err(EvalError::Unimplemented(format!("can't handle type: {:?}", ty))),
1078 fn get_field_offset(&self, ty: Ty<'tcx>, field_index: usize) -> EvalResult<Size> {
1079 let layout = self.type_layout(ty, self.substs());
1081 use rustc::ty::layout::Layout::*;
1083 Univariant { .. } => {
1084 assert_eq!(field_index, 0);
1085 Ok(Size::from_bytes(0))
1087 FatPointer { .. } => {
1088 let bytes = layout::FAT_PTR_ADDR * self.memory.pointer_size;
1089 Ok(Size::from_bytes(bytes as u64))
1091 _ => Err(EvalError::Unimplemented(format!("can't handle type: {:?}, with layout: {:?}", ty, layout))),
1095 fn eval_operand(&mut self, op: &mir::Operand<'tcx>) -> EvalResult<Pointer> {
1096 use rustc::mir::repr::Operand::*;
1098 Consume(ref lvalue) => Ok(self.eval_lvalue(lvalue)?.to_ptr()),
1099 Constant(mir::Constant { ref literal, ty, .. }) => {
1100 use rustc::mir::repr::Literal::*;
1102 Value { ref value } => Ok(self.const_to_ptr(value)?),
1103 Item { def_id, substs } => {
1104 if let ty::TyFnDef(..) = ty.sty {
1105 Err(EvalError::Unimplemented("unimplemented: mentions of function items".to_string()))
1107 let cid = ConstantId {
1110 kind: ConstantKind::Global,
1112 Ok(*self.statics.get(&cid).expect("static should have been cached (rvalue)"))
1115 Promoted { index } => {
1116 let cid = ConstantId {
1117 def_id: self.frame().def_id,
1118 substs: self.substs(),
1119 kind: ConstantKind::Promoted(index),
1121 Ok(*self.statics.get(&cid).expect("a promoted constant hasn't been precomputed"))
1128 fn eval_lvalue(&mut self, lvalue: &mir::Lvalue<'tcx>) -> EvalResult<Lvalue> {
1129 use rustc::mir::repr::Lvalue::*;
1130 let ptr = match *lvalue {
1131 ReturnPointer => self.frame().return_ptr
1132 .expect("ReturnPointer used in a function with no return value"),
1133 Arg(i) => self.frame().locals[i as usize],
1134 Var(i) => self.frame().locals[self.frame().var_offset + i as usize],
1135 Temp(i) => self.frame().locals[self.frame().temp_offset + i as usize],
1138 let substs = self.tcx.mk_substs(subst::Substs::empty());
1139 let cid = ConstantId {
1142 kind: ConstantKind::Global,
1144 *self.statics.get(&cid).expect("static should have been cached (lvalue)")
1147 Projection(ref proj) => {
1148 let base = self.eval_lvalue(&proj.base)?;
1149 let base_ty = self.lvalue_ty(&proj.base);
1150 let base_layout = self.type_layout(base_ty, self.substs());
1152 use rustc::mir::repr::ProjectionElem::*;
1154 Field(field, _) => {
1155 use rustc::ty::layout::Layout::*;
1156 let variant = match *base_layout {
1157 Univariant { ref variant, .. } => variant,
1158 General { ref variants, .. } => {
1159 if let LvalueExtra::DowncastVariant(variant_idx) = base.extra {
1160 &variants[variant_idx]
1162 panic!("field access on enum had no variant index");
1165 RawNullablePointer { .. } => {
1166 assert_eq!(field.index(), 0);
1169 StructWrappedNullablePointer { ref nonnull, .. } => nonnull,
1170 _ => panic!("field access on non-product type: {:?}", base_layout),
1173 let offset = variant.field_offset(field.index()).bytes();
1174 base.ptr.offset(offset as isize)
1177 Downcast(_, variant) => {
1178 use rustc::ty::layout::Layout::*;
1179 match *base_layout {
1180 General { discr, .. } => {
1182 ptr: base.ptr.offset(discr.size().bytes() as isize),
1183 extra: LvalueExtra::DowncastVariant(variant),
1186 RawNullablePointer { .. } | StructWrappedNullablePointer { .. } => {
1189 _ => panic!("variant downcast on non-aggregate: {:?}", base_layout),
1194 let pointee_ty = pointee_type(base_ty).expect("Deref of non-pointer");
1195 let ptr = self.memory.read_ptr(base.ptr)?;
1196 let extra = match pointee_ty.sty {
1197 ty::TySlice(_) | ty::TyStr => {
1198 let len_ptr = base.ptr.offset(self.memory.pointer_size as isize);
1199 let len = self.memory.read_usize(len_ptr)?;
1200 LvalueExtra::Length(len)
1202 ty::TyTrait(_) => unimplemented!(),
1203 _ => LvalueExtra::None,
1205 return Ok(Lvalue { ptr: ptr, extra: extra });
1208 Index(ref operand) => {
1209 let elem_size = match base_ty.sty {
1210 ty::TyArray(elem_ty, _) |
1211 ty::TySlice(elem_ty) => self.type_size(elem_ty, self.substs()),
1212 _ => panic!("indexing expected an array or slice, got {:?}", base_ty),
1214 let n_ptr = self.eval_operand(operand)?;
1215 let n = self.memory.read_usize(n_ptr)?;
1216 base.ptr.offset(n as isize * elem_size as isize)
1219 ConstantIndex { .. } => unimplemented!(),
1224 Ok(Lvalue { ptr: ptr, extra: LvalueExtra::None })
1227 fn lvalue_ty(&self, lvalue: &mir::Lvalue<'tcx>) -> Ty<'tcx> {
1228 self.monomorphize(self.mir().lvalue_ty(self.tcx, lvalue).to_ty(self.tcx), self.substs())
1231 fn operand_ty(&self, operand: &mir::Operand<'tcx>) -> Ty<'tcx> {
1232 self.monomorphize(self.mir().operand_ty(self.tcx, operand), self.substs())
1235 fn move_(&mut self, src: Pointer, dest: Pointer, ty: Ty<'tcx>) -> EvalResult<()> {
1236 let size = self.type_size(ty, self.substs());
1237 self.memory.copy(src, dest, size)?;
1238 if self.type_needs_drop(ty) {
1239 self.memory.drop_fill(src, size)?;
1244 pub fn read_primval(&mut self, ptr: Pointer, ty: Ty<'tcx>) -> EvalResult<PrimVal> {
1245 use syntax::ast::{IntTy, UintTy};
1246 let val = match (self.memory.pointer_size, &ty.sty) {
1247 (_, &ty::TyBool) => PrimVal::Bool(self.memory.read_bool(ptr)?),
1248 (_, &ty::TyInt(IntTy::I8)) => PrimVal::I8(self.memory.read_int(ptr, 1)? as i8),
1249 (2, &ty::TyInt(IntTy::Is)) |
1250 (_, &ty::TyInt(IntTy::I16)) => PrimVal::I16(self.memory.read_int(ptr, 2)? as i16),
1251 (4, &ty::TyInt(IntTy::Is)) |
1252 (_, &ty::TyInt(IntTy::I32)) => PrimVal::I32(self.memory.read_int(ptr, 4)? as i32),
1253 (8, &ty::TyInt(IntTy::Is)) |
1254 (_, &ty::TyInt(IntTy::I64)) => PrimVal::I64(self.memory.read_int(ptr, 8)? as i64),
1255 (_, &ty::TyUint(UintTy::U8)) => PrimVal::U8(self.memory.read_uint(ptr, 1)? as u8),
1256 (2, &ty::TyUint(UintTy::Us)) |
1257 (_, &ty::TyUint(UintTy::U16)) => PrimVal::U16(self.memory.read_uint(ptr, 2)? as u16),
1258 (4, &ty::TyUint(UintTy::Us)) |
1259 (_, &ty::TyUint(UintTy::U32)) => PrimVal::U32(self.memory.read_uint(ptr, 4)? as u32),
1260 (8, &ty::TyUint(UintTy::Us)) |
1261 (_, &ty::TyUint(UintTy::U64)) => PrimVal::U64(self.memory.read_uint(ptr, 8)? as u64),
1263 (_, &ty::TyRef(_, ty::TypeAndMut { ty, .. })) |
1264 (_, &ty::TyRawPtr(ty::TypeAndMut { ty, .. })) => {
1265 if self.type_is_sized(ty) {
1266 match self.memory.read_ptr(ptr) {
1267 Ok(p) => PrimVal::AbstractPtr(p),
1268 Err(EvalError::ReadBytesAsPointer) => {
1269 PrimVal::IntegerPtr(self.memory.read_usize(ptr)?)
1271 Err(e) => return Err(e),
1274 return Err(EvalError::Unimplemented(format!("unimplemented: primitive read of fat pointer type: {:?}", ty)));
1278 _ => panic!("primitive read of non-primitive type: {:?}", ty),
1283 fn frame(&self) -> &Frame<'a, 'tcx> {
1284 self.stack.last().expect("no call frames exist")
1287 fn basic_block(&self) -> &mir::BasicBlockData<'tcx> {
1288 let frame = self.frame();
1289 frame.mir.basic_block_data(frame.next_block)
1292 fn frame_mut(&mut self) -> &mut Frame<'a, 'tcx> {
1293 self.stack.last_mut().expect("no call frames exist")
1296 fn mir(&self) -> CachedMir<'a, 'tcx> {
1297 self.frame().mir.clone()
1300 fn substs(&self) -> &'tcx Substs<'tcx> {
1305 fn pointee_type(ptr_ty: ty::Ty) -> Option<ty::Ty> {
1307 ty::TyRef(_, ty::TypeAndMut { ty, .. }) |
1308 ty::TyRawPtr(ty::TypeAndMut { ty, .. }) |
1317 fn to_ptr(self) -> Pointer {
1318 assert_eq!(self.extra, LvalueExtra::None);
1323 impl<'mir, 'tcx: 'mir> Deref for CachedMir<'mir, 'tcx> {
1324 type Target = mir::Mir<'tcx>;
1325 fn deref(&self) -> &mir::Mir<'tcx> {
1327 CachedMir::Ref(r) => r,
1328 CachedMir::Owned(ref rc) => rc,
1334 pub struct ImplMethod<'tcx> {
1335 pub method: Rc<ty::Method<'tcx>>,
1336 pub substs: &'tcx Substs<'tcx>,
1337 pub is_provided: bool,
1340 /// Locates the applicable definition of a method, given its name.
1341 pub fn get_impl_method<'a, 'tcx>(
1342 tcx: TyCtxt<'a, 'tcx, 'tcx>,
1344 substs: &'tcx Substs<'tcx>,
1346 ) -> ImplMethod<'tcx> {
1347 assert!(!substs.types.needs_infer());
1349 let trait_def_id = tcx.trait_id_of_impl(impl_def_id).unwrap();
1350 let trait_def = tcx.lookup_trait_def(trait_def_id);
1352 match trait_def.ancestors(impl_def_id).fn_defs(tcx, name).next() {
1353 Some(node_item) => {
1354 let substs = tcx.normalizing_infer_ctxt(ProjectionMode::Any).enter(|infcx| {
1355 let substs = traits::translate_substs(&infcx, impl_def_id,
1356 substs, node_item.node);
1357 tcx.lift(&substs).unwrap_or_else(|| {
1358 bug!("trans::meth::get_impl_method: translate_substs \
1359 returned {:?} which contains inference types/regions",
1364 method: node_item.item,
1366 is_provided: node_item.node.is_from_trait(),
1370 bug!("method {:?} not found in {:?}", name, impl_def_id)
1375 // TODO(solson): Upstream these methods into rustc::ty::layout.
1378 fn size(self) -> Size;
1381 impl IntegerExt for layout::Integer {
1382 fn size(self) -> Size {
1383 use rustc::ty::layout::Integer::*;
1385 I1 | I8 => Size::from_bits(8),
1386 I16 => Size::from_bits(16),
1387 I32 => Size::from_bits(32),
1388 I64 => Size::from_bits(64),
1394 fn field_offset(&self, index: usize) -> Size;
1397 impl StructExt for layout::Struct {
1398 fn field_offset(&self, index: usize) -> Size {
1402 self.offset_after_field[index - 1]