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;
12 use std::ops::{Deref, DerefMut};
17 use syntax::codemap::{self, DUMMY_SP};
19 use error::{EvalError, EvalResult};
20 use memory::{Memory, Pointer};
21 use primval::{self, PrimVal};
23 const TRACE_EXECUTION: bool = true;
25 struct GlobalEvalContext<'a, 'tcx: 'a> {
26 /// The results of the type checker, from rustc.
27 tcx: TyCtxt<'a, 'tcx, 'tcx>,
29 /// A mapping from NodeIds to Mir, from rustc. Only contains MIR for crate-local items.
30 mir_map: &'a MirMap<'tcx>,
32 /// A local cache from DefIds to Mir for non-crate-local items.
33 mir_cache: RefCell<DefIdMap<Rc<mir::Mir<'tcx>>>>,
35 /// The virtual memory system.
38 /// Another stack containing the type substitutions for the current function invocation. It
39 /// exists separately from `stack` because it must contain the `Substs` for a function while
40 /// *creating* the `Frame` for that same function.
41 substs_stack: Vec<&'tcx Substs<'tcx>>,
43 // TODO(solson): Merge with `substs_stack`. Also try restructuring `Frame` to accomodate.
44 /// A stack of the things necessary to print good strack traces:
45 /// * Function DefIds and Substs to print proper substituted function names.
46 /// * Spans pointing to specific function calls in the source.
47 name_stack: Vec<(DefId, &'tcx Substs<'tcx>, codemap::Span)>,
50 struct FnEvalContext<'a, 'b: 'a + 'mir, 'mir, 'tcx: 'b> {
51 gecx: &'a mut GlobalEvalContext<'b, 'tcx>,
53 /// The virtual call stack.
54 stack: Vec<Frame<'mir, 'tcx>>,
57 impl<'a, 'b, 'mir, 'tcx> Deref for FnEvalContext<'a, 'b, 'mir, 'tcx> {
58 type Target = GlobalEvalContext<'b, 'tcx>;
59 fn deref(&self) -> &Self::Target {
64 impl<'a, 'b, 'mir, 'tcx> DerefMut for FnEvalContext<'a, 'b, 'mir, 'tcx> {
65 fn deref_mut(&mut self) -> &mut Self::Target {
71 struct Frame<'a, 'tcx: 'a> {
72 /// The MIR for the function called on this frame.
73 mir: CachedMir<'a, 'tcx>,
75 /// The block this frame will execute when a function call returns back to this frame.
76 next_block: mir::BasicBlock,
78 /// A pointer for writing the return value of the current call if it's not a diverging call.
79 return_ptr: Option<Pointer>,
81 /// The list of locals for the current function, stored in order as
82 /// `[arguments..., variables..., temporaries...]`. The variables begin at `self.var_offset`
83 /// and the temporaries at `self.temp_offset`.
86 /// The offset of the first variable in `self.locals`.
89 /// The offset of the first temporary in `self.locals`.
93 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
99 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
103 // TODO(solson): Vtable(memory::AllocId),
104 DowncastVariant(usize),
108 enum CachedMir<'mir, 'tcx: 'mir> {
109 Ref(&'mir mir::Mir<'tcx>),
110 Owned(Rc<mir::Mir<'tcx>>)
113 /// Represents the action to be taken in the main loop as a result of executing a terminator.
114 enum TerminatorTarget {
115 /// Make a local jump to the given block.
116 Block(mir::BasicBlock),
118 /// Start executing from the new current frame. (For function calls.)
121 /// Stop executing the current frame and resume the previous frame.
125 impl<'a, 'tcx> GlobalEvalContext<'a, 'tcx> {
126 fn new(tcx: TyCtxt<'a, 'tcx, 'tcx>, mir_map: &'a MirMap<'tcx>) -> Self {
130 mir_cache: RefCell::new(DefIdMap()),
131 memory: Memory::new(),
132 substs_stack: Vec::new(),
133 name_stack: Vec::new(),
138 impl<'a, 'b, 'mir, 'tcx> FnEvalContext<'a, 'b, 'mir, 'tcx> {
139 fn new(gecx: &'a mut GlobalEvalContext<'b, 'tcx>) -> Self {
146 fn maybe_report<T>(&self, span: codemap::Span, r: EvalResult<T>) -> EvalResult<T> {
147 if let Err(ref e) = r {
148 let mut err = self.tcx.sess.struct_span_err(span, &e.to_string());
149 for &(def_id, substs, span) in self.name_stack.iter().rev() {
150 // FIXME(solson): Find a way to do this without this Display impl hack.
151 use rustc::util::ppaux;
153 struct Instance<'tcx>(DefId, &'tcx Substs<'tcx>);
154 impl<'tcx> fmt::Display for Instance<'tcx> {
155 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
156 ppaux::parameterized(f, self.1, self.0, ppaux::Ns::Value, &[],
157 |tcx| tcx.lookup_item_type(self.0).generics)
160 err.span_note(span, &format!("inside call to {}", Instance(def_id, substs)));
167 fn log<F>(&self, extra_indent: usize, f: F) where F: FnOnce() {
168 let indent = self.stack.len() + extra_indent;
169 if !TRACE_EXECUTION { return; }
170 for _ in 0..indent { print!(" "); }
175 fn run(&mut self) -> EvalResult<()> {
176 'outer: while !self.stack.is_empty() {
177 let mut current_block = self.frame().next_block;
180 self.log(0, || print!("// {:?}", current_block));
181 let current_mir = self.mir().clone(); // Cloning a reference.
182 let block_data = current_mir.basic_block_data(current_block);
184 for stmt in &block_data.statements {
185 self.log(0, || print!("{:?}", stmt));
186 let mir::StatementKind::Assign(ref lvalue, ref rvalue) = stmt.kind;
187 let result = self.eval_assignment(lvalue, rvalue);
188 self.maybe_report(stmt.span, result)?;
191 let terminator = block_data.terminator();
192 self.log(0, || print!("{:?}", terminator.kind));
194 let result = self.eval_terminator(terminator);
195 match self.maybe_report(terminator.span, result)? {
196 TerminatorTarget::Block(block) => current_block = block,
197 TerminatorTarget::Return => {
198 self.pop_stack_frame();
199 self.name_stack.pop();
202 TerminatorTarget::Call => continue 'outer,
210 fn call_nested(&mut self, mir: &mir::Mir<'tcx>) -> EvalResult<Option<Pointer>> {
211 let mut nested_fecx = FnEvalContext::new(self.gecx);
213 let return_ptr = match mir.return_ty {
214 ty::FnConverging(ty) => {
215 let size = nested_fecx.type_size(ty);
216 Some(nested_fecx.memory.allocate(size))
218 ty::FnDiverging => None,
221 let substs = nested_fecx.substs();
222 nested_fecx.push_stack_frame(CachedMir::Ref(mir), substs, return_ptr);
227 fn push_stack_frame(&mut self, mir: CachedMir<'mir, 'tcx>, substs: &'tcx Substs<'tcx>,
228 return_ptr: Option<Pointer>)
230 self.substs_stack.push(substs);
232 let arg_tys = mir.arg_decls.iter().map(|a| a.ty);
233 let var_tys = mir.var_decls.iter().map(|v| v.ty);
234 let temp_tys = mir.temp_decls.iter().map(|t| t.ty);
236 let locals: Vec<Pointer> = arg_tys.chain(var_tys).chain(temp_tys).map(|ty| {
237 let size = self.type_size(ty);
238 self.memory.allocate(size)
241 let num_args = mir.arg_decls.len();
242 let num_vars = mir.var_decls.len();
244 self.stack.push(Frame {
246 next_block: mir::START_BLOCK,
247 return_ptr: return_ptr,
249 var_offset: num_args,
250 temp_offset: num_args + num_vars,
254 fn pop_stack_frame(&mut self) {
255 let _frame = self.stack.pop().expect("tried to pop a stack frame, but there were none");
256 // TODO(solson): Deallocate local variables.
257 self.substs_stack.pop();
260 fn eval_terminator(&mut self, terminator: &mir::Terminator<'tcx>)
261 -> EvalResult<TerminatorTarget> {
262 use rustc::mir::repr::TerminatorKind::*;
263 let target = match terminator.kind {
264 Return => TerminatorTarget::Return,
266 Goto { target } => TerminatorTarget::Block(target),
268 If { ref cond, targets: (then_target, else_target) } => {
269 let cond_ptr = self.eval_operand(cond)?;
270 let cond_val = self.memory.read_bool(cond_ptr)?;
271 TerminatorTarget::Block(if cond_val { then_target } else { else_target })
274 SwitchInt { ref discr, ref values, ref targets, .. } => {
275 let discr_ptr = self.eval_lvalue(discr)?.to_ptr();
276 let discr_size = self
277 .type_layout(self.lvalue_ty(discr))
278 .size(&self.tcx.data_layout)
280 let discr_val = self.memory.read_uint(discr_ptr, discr_size)?;
282 // Branch to the `otherwise` case by default, if no match is found.
283 let mut target_block = targets[targets.len() - 1];
285 for (index, val_const) in values.iter().enumerate() {
286 let ptr = self.const_to_ptr(val_const)?;
287 let val = self.memory.read_uint(ptr, discr_size)?;
288 if discr_val == val {
289 target_block = targets[index];
294 TerminatorTarget::Block(target_block)
297 Switch { ref discr, ref targets, adt_def } => {
298 let adt_ptr = self.eval_lvalue(discr)?.to_ptr();
299 let adt_ty = self.lvalue_ty(discr);
300 let discr_val = self.read_discriminant_value(adt_ptr, adt_ty)?;
301 let matching = adt_def.variants.iter()
302 .position(|v| discr_val == v.disr_val.to_u64_unchecked());
305 Some(i) => TerminatorTarget::Block(targets[i]),
306 None => return Err(EvalError::InvalidDiscriminant),
310 Call { ref func, ref args, ref destination, .. } => {
311 let mut return_ptr = None;
312 if let Some((ref lv, target)) = *destination {
313 self.frame_mut().next_block = target;
314 return_ptr = Some(self.eval_lvalue(lv)?.to_ptr());
317 let func_ty = self.operand_ty(func);
319 ty::TyFnDef(def_id, substs, fn_ty) => {
320 use syntax::abi::Abi;
322 Abi::RustIntrinsic => {
323 let name = self.tcx.item_name(def_id).as_str();
324 match fn_ty.sig.0.output {
325 ty::FnConverging(ty) => {
326 let size = self.type_size(ty);
327 let ret = return_ptr.unwrap();
328 self.call_intrinsic(&name, substs, args, ret, size)?
330 ty::FnDiverging => unimplemented!(),
335 match fn_ty.sig.0.output {
336 ty::FnConverging(ty) => {
337 let size = self.type_size(ty);
338 self.call_c_abi(def_id, args, return_ptr.unwrap(), size)?
340 ty::FnDiverging => unimplemented!(),
344 Abi::Rust | Abi::RustCall => {
345 // TODO(solson): Adjust the first argument when calling a Fn or
346 // FnMut closure via FnOnce::call_once.
348 // Only trait methods can have a Self parameter.
349 let (resolved_def_id, resolved_substs) = if substs.self_ty().is_some() {
350 self.trait_method(def_id, substs)
355 let mut arg_srcs = Vec::new();
357 let src = self.eval_operand(arg)?;
358 let src_ty = self.operand_ty(arg);
359 arg_srcs.push((src, src_ty));
362 if fn_ty.abi == Abi::RustCall && !args.is_empty() {
364 let last_arg = args.last().unwrap();
365 let last = self.eval_operand(last_arg)?;
366 let last_ty = self.operand_ty(last_arg);
367 let last_layout = self.type_layout(last_ty);
368 match (&last_ty.sty, last_layout) {
369 (&ty::TyTuple(fields),
370 &Layout::Univariant { ref variant, .. }) => {
371 let offsets = iter::once(0)
372 .chain(variant.offset_after_field.iter()
373 .map(|s| s.bytes()));
374 for (offset, ty) in offsets.zip(fields) {
375 let src = last.offset(offset as isize);
376 arg_srcs.push((src, ty));
379 ty => panic!("expected tuple as last argument in function with 'rust-call' ABI, got {:?}", ty),
383 let mir = self.load_mir(resolved_def_id);
384 self.name_stack.push((def_id, substs, terminator.span));
385 self.push_stack_frame(mir, resolved_substs, return_ptr);
387 for (i, (src, src_ty)) in arg_srcs.into_iter().enumerate() {
388 let dest = self.frame().locals[i];
389 self.move_(src, dest, src_ty)?;
392 TerminatorTarget::Call
395 abi => panic!("can't handle function with {:?} ABI", abi),
399 _ => panic!("can't handle callee of type {:?}", func_ty),
403 Drop { ref value, target, .. } => {
404 let ptr = self.eval_lvalue(value)?.to_ptr();
405 let ty = self.lvalue_ty(value);
407 TerminatorTarget::Block(target)
410 Resume => unimplemented!(),
416 fn drop(&mut self, ptr: Pointer, ty: Ty<'tcx>) -> EvalResult<()> {
417 if !self.type_needs_drop(ty) {
418 self.log(1, || print!("no need to drop {:?}", ty));
421 self.log(1, || print!("need to drop {:?}", ty));
423 // TODO(solson): Call user-defined Drop::drop impls.
426 ty::TyBox(contents_ty) => {
427 match self.memory.read_ptr(ptr) {
428 Ok(contents_ptr) => {
429 self.drop(contents_ptr, contents_ty)?;
430 self.log(1, || print!("deallocating box"));
431 self.memory.deallocate(contents_ptr)?;
433 Err(EvalError::ReadBytesAsPointer) => {
434 let size = self.memory.pointer_size;
435 let possible_drop_fill = self.memory.read_bytes(ptr, size)?;
436 if possible_drop_fill.iter().all(|&b| b == mem::POST_DROP_U8) {
439 return Err(EvalError::ReadBytesAsPointer);
442 Err(e) => return Err(e),
446 // TODO(solson): Implement drop for other relevant types (e.g. aggregates).
451 // FIXME(solson): Trait objects (with no static size) probably get filled, too.
452 let size = self.type_size(ty);
453 self.memory.drop_fill(ptr, size)?;
458 fn read_discriminant_value(&self, adt_ptr: Pointer, adt_ty: Ty<'tcx>) -> EvalResult<u64> {
459 use rustc::ty::layout::Layout::*;
460 let adt_layout = self.type_layout(adt_ty);
462 let discr_val = match *adt_layout {
463 General { discr, .. } | CEnum { discr, .. } => {
464 let discr_size = discr.size().bytes();
465 self.memory.read_uint(adt_ptr, discr_size as usize)?
468 RawNullablePointer { nndiscr, .. } => {
469 self.read_nonnull_discriminant_value(adt_ptr, nndiscr)?
472 StructWrappedNullablePointer { nndiscr, ref discrfield, .. } => {
473 let offset = self.nonnull_offset(adt_ty, nndiscr, discrfield);
474 let nonnull = adt_ptr.offset(offset.bytes() as isize);
475 self.read_nonnull_discriminant_value(nonnull, nndiscr)?
478 // The discriminant_value intrinsic returns 0 for non-sum types.
479 Array { .. } | FatPointer { .. } | Scalar { .. } | Univariant { .. } |
486 fn read_nonnull_discriminant_value(&self, ptr: Pointer, nndiscr: u64) -> EvalResult<u64> {
487 let not_null = match self.memory.read_usize(ptr) {
489 Ok(_) | Err(EvalError::ReadPointerAsBytes) => true,
490 Err(e) => return Err(e),
492 assert!(nndiscr == 0 || nndiscr == 1);
493 Ok(if not_null { nndiscr } else { 1 - nndiscr })
499 substs: &'tcx Substs<'tcx>,
500 args: &[mir::Operand<'tcx>],
503 ) -> EvalResult<TerminatorTarget> {
504 let args_res: EvalResult<Vec<Pointer>> = args.iter()
505 .map(|arg| self.eval_operand(arg))
507 let args = args_res?;
510 // FIXME(solson): Handle different integer types correctly.
511 "add_with_overflow" => {
512 let ty = *substs.types.get(subst::FnSpace, 0);
513 let size = self.type_size(ty);
514 let left = self.memory.read_int(args[0], size)?;
515 let right = self.memory.read_int(args[1], size)?;
516 let (n, overflowed) = unsafe {
517 ::std::intrinsics::add_with_overflow::<i64>(left, right)
519 self.memory.write_int(dest, n, size)?;
520 self.memory.write_bool(dest.offset(size as isize), overflowed)?;
525 "copy_nonoverlapping" => {
526 let elem_ty = *substs.types.get(subst::FnSpace, 0);
527 let elem_size = self.type_size(elem_ty);
528 let src = self.memory.read_ptr(args[0])?;
529 let dest = self.memory.read_ptr(args[1])?;
530 let count = self.memory.read_isize(args[2])?;
531 self.memory.copy(src, dest, count as usize * elem_size)?;
534 "discriminant_value" => {
535 let ty = *substs.types.get(subst::FnSpace, 0);
536 let adt_ptr = self.memory.read_ptr(args[0])?;
537 let discr_val = self.read_discriminant_value(adt_ptr, ty)?;
538 self.memory.write_uint(dest, discr_val, dest_size)?;
542 let arg_ty = *substs.types.get(subst::FnSpace, 0);
543 let arg_size = self.type_size(arg_ty);
544 self.memory.drop_fill(args[0], arg_size)?;
547 "init" => self.memory.write_repeat(dest, 0, dest_size)?,
550 self.memory.write_int(dest, 1, dest_size)?;
554 let ty = *substs.types.get(subst::FnSpace, 0);
555 let ptr = self.memory.read_ptr(args[0])?;
556 self.move_(args[1], ptr, ty)?;
559 // FIXME(solson): Handle different integer types correctly.
560 "mul_with_overflow" => {
561 let ty = *substs.types.get(subst::FnSpace, 0);
562 let size = self.type_size(ty);
563 let left = self.memory.read_int(args[0], size)?;
564 let right = self.memory.read_int(args[1], size)?;
565 let (n, overflowed) = unsafe {
566 ::std::intrinsics::mul_with_overflow::<i64>(left, right)
568 self.memory.write_int(dest, n, size)?;
569 self.memory.write_bool(dest.offset(size as isize), overflowed)?;
573 let pointee_ty = *substs.types.get(subst::FnSpace, 0);
574 let pointee_size = self.type_size(pointee_ty) as isize;
575 let ptr_arg = args[0];
576 let offset = self.memory.read_isize(args[1])?;
578 match self.memory.read_ptr(ptr_arg) {
580 let result_ptr = ptr.offset(offset as isize * pointee_size);
581 self.memory.write_ptr(dest, result_ptr)?;
583 Err(EvalError::ReadBytesAsPointer) => {
584 let addr = self.memory.read_isize(ptr_arg)?;
585 let result_addr = addr + offset * pointee_size as i64;
586 self.memory.write_isize(dest, result_addr)?;
588 Err(e) => return Err(e),
592 // FIXME(solson): Handle different integer types correctly. Use primvals?
593 "overflowing_sub" => {
594 let ty = *substs.types.get(subst::FnSpace, 0);
595 let size = self.type_size(ty);
596 let left = self.memory.read_int(args[0], size)?;
597 let right = self.memory.read_int(args[1], size)?;
598 let n = left.wrapping_sub(right);
599 self.memory.write_int(dest, n, size)?;
603 let ty = *substs.types.get(subst::FnSpace, 0);
604 let size = self.type_size(ty) as u64;
605 self.memory.write_uint(dest, size, dest_size)?;
609 let ty = *substs.types.get(subst::FnSpace, 0);
610 if self.type_is_sized(ty) {
611 let size = self.type_size(ty) as u64;
612 self.memory.write_uint(dest, size, dest_size)?;
615 ty::TySlice(_) | ty::TyStr => {
616 let elem_ty = ty.sequence_element_type(self.tcx);
617 let elem_size = self.type_size(elem_ty) as u64;
618 let ptr_size = self.memory.pointer_size as isize;
619 let n = self.memory.read_usize(args[0].offset(ptr_size))?;
620 self.memory.write_uint(dest, n * elem_size, dest_size)?;
623 _ => panic!("unimplemented: size_of_val::<{:?}>", ty),
629 let ty = *substs.types.get(subst::FnSpace, 0);
630 self.move_(args[0], dest, ty)?;
632 "uninit" => self.memory.mark_definedness(dest, dest_size, false)?,
634 name => panic!("can't handle intrinsic: {}", name),
637 // Since we pushed no stack frame, the main loop will act
638 // as if the call just completed and it's returning to the
640 Ok(TerminatorTarget::Call)
646 args: &[mir::Operand<'tcx>],
649 ) -> EvalResult<TerminatorTarget> {
650 let name = self.tcx.item_name(def_id);
651 let attrs = self.tcx.get_attrs(def_id);
652 let link_name = match attr::first_attr_value_str_by_name(&attrs, "link_name") {
653 Some(ln) => ln.clone(),
654 None => name.as_str(),
657 let args_res: EvalResult<Vec<Pointer>> = args.iter()
658 .map(|arg| self.eval_operand(arg))
660 let args = args_res?;
662 match &link_name[..] {
663 "__rust_allocate" => {
664 let size = self.memory.read_usize(args[0])?;
665 let ptr = self.memory.allocate(size as usize);
666 self.memory.write_ptr(dest, ptr)?;
669 "__rust_reallocate" => {
670 let ptr = self.memory.read_ptr(args[0])?;
671 let size = self.memory.read_usize(args[2])?;
672 self.memory.reallocate(ptr, size as usize)?;
673 self.memory.write_ptr(dest, ptr)?;
677 let left = self.memory.read_ptr(args[0])?;
678 let right = self.memory.read_ptr(args[1])?;
679 let n = self.memory.read_usize(args[2])? as usize;
682 let left_bytes = self.memory.read_bytes(left, n)?;
683 let right_bytes = self.memory.read_bytes(right, n)?;
685 use std::cmp::Ordering::*;
686 match left_bytes.cmp(right_bytes) {
693 self.memory.write_int(dest, result, dest_size)?;
696 _ => panic!("can't call C ABI function: {}", link_name),
699 // Since we pushed no stack frame, the main loop will act
700 // as if the call just completed and it's returning to the
702 Ok(TerminatorTarget::Call)
705 fn assign_fields<I: IntoIterator<Item = u64>>(
709 operands: &[mir::Operand<'tcx>],
710 ) -> EvalResult<()> {
711 for (offset, operand) in offsets.into_iter().zip(operands) {
712 let src = self.eval_operand(operand)?;
713 let src_ty = self.operand_ty(operand);
714 let field_dest = dest.offset(offset as isize);
715 self.move_(src, field_dest, src_ty)?;
720 fn eval_assignment(&mut self, lvalue: &mir::Lvalue<'tcx>, rvalue: &mir::Rvalue<'tcx>)
723 let dest = self.eval_lvalue(lvalue)?.to_ptr();
724 let dest_ty = self.lvalue_ty(lvalue);
725 let dest_layout = self.type_layout(dest_ty);
727 use rustc::mir::repr::Rvalue::*;
729 Use(ref operand) => {
730 let src = self.eval_operand(operand)?;
731 self.move_(src, dest, dest_ty)?;
734 BinaryOp(bin_op, ref left, ref right) => {
735 let left_ptr = self.eval_operand(left)?;
736 let left_ty = self.operand_ty(left);
737 let left_val = self.read_primval(left_ptr, left_ty)?;
739 let right_ptr = self.eval_operand(right)?;
740 let right_ty = self.operand_ty(right);
741 let right_val = self.read_primval(right_ptr, right_ty)?;
743 let val = primval::binary_op(bin_op, left_val, right_val)?;
744 self.memory.write_primval(dest, val)?;
747 UnaryOp(un_op, ref operand) => {
748 let ptr = self.eval_operand(operand)?;
749 let ty = self.operand_ty(operand);
750 let val = self.read_primval(ptr, ty)?;
751 self.memory.write_primval(dest, primval::unary_op(un_op, val))?;
754 Aggregate(ref kind, ref operands) => {
755 use rustc::ty::layout::Layout::*;
757 Univariant { ref variant, .. } => {
758 let offsets = iter::once(0)
759 .chain(variant.offset_after_field.iter().map(|s| s.bytes()));
760 self.assign_fields(dest, offsets, operands)?;
764 let elem_size = match dest_ty.sty {
765 ty::TyArray(elem_ty, _) => self.type_size(elem_ty) as u64,
766 _ => panic!("tried to assign {:?} to non-array type {:?}",
769 let offsets = (0..).map(|i| i * elem_size);
770 self.assign_fields(dest, offsets, operands)?;
773 General { discr, ref variants, .. } => {
774 if let mir::AggregateKind::Adt(adt_def, variant, _) = *kind {
775 let discr_val = adt_def.variants[variant].disr_val.to_u64_unchecked();
776 let discr_size = discr.size().bytes() as usize;
777 self.memory.write_uint(dest, discr_val, discr_size)?;
779 let offsets = variants[variant].offset_after_field.iter()
781 self.assign_fields(dest, offsets, operands)?;
783 panic!("tried to assign {:?} to Layout::General", kind);
787 RawNullablePointer { nndiscr, .. } => {
788 if let mir::AggregateKind::Adt(_, variant, _) = *kind {
789 if nndiscr == variant as u64 {
790 assert_eq!(operands.len(), 1);
791 let operand = &operands[0];
792 let src = self.eval_operand(operand)?;
793 let src_ty = self.operand_ty(operand);
794 self.move_(src, dest, src_ty)?;
796 assert_eq!(operands.len(), 0);
797 self.memory.write_isize(dest, 0)?;
800 panic!("tried to assign {:?} to Layout::RawNullablePointer", kind);
804 StructWrappedNullablePointer { nndiscr, ref nonnull, ref discrfield } => {
805 if let mir::AggregateKind::Adt(_, variant, _) = *kind {
806 if nndiscr == variant as u64 {
807 let offsets = iter::once(0)
808 .chain(nonnull.offset_after_field.iter().map(|s| s.bytes()));
809 try!(self.assign_fields(dest, offsets, operands));
811 assert_eq!(operands.len(), 0);
812 let offset = self.nonnull_offset(dest_ty, nndiscr, discrfield);
813 let dest = dest.offset(offset.bytes() as isize);
814 try!(self.memory.write_isize(dest, 0));
817 panic!("tried to assign {:?} to Layout::RawNullablePointer", kind);
821 CEnum { discr, signed, .. } => {
822 assert_eq!(operands.len(), 0);
823 if let mir::AggregateKind::Adt(adt_def, variant, _) = *kind {
824 let val = adt_def.variants[variant].disr_val.to_u64_unchecked();
825 let size = discr.size().bytes() as usize;
828 self.memory.write_int(dest, val as i64, size)?;
830 self.memory.write_uint(dest, val, size)?;
833 panic!("tried to assign {:?} to Layout::CEnum", kind);
837 _ => panic!("can't handle destination layout {:?} when assigning {:?}",
842 Repeat(ref operand, _) => {
843 let (elem_size, length) = match dest_ty.sty {
844 ty::TyArray(elem_ty, n) => (self.type_size(elem_ty), n),
845 _ => panic!("tried to assign array-repeat to non-array type {:?}", dest_ty),
848 let src = self.eval_operand(operand)?;
850 let elem_dest = dest.offset((i * elem_size) as isize);
851 self.memory.copy(src, elem_dest, elem_size)?;
856 let src = self.eval_lvalue(lvalue)?;
857 let ty = self.lvalue_ty(lvalue);
858 let len = match ty.sty {
859 ty::TyArray(_, n) => n as u64,
860 ty::TySlice(_) => if let LvalueExtra::Length(n) = src.extra {
863 panic!("Rvalue::Len of a slice given non-slice pointer: {:?}", src);
865 _ => panic!("Rvalue::Len expected array or slice, got {:?}", ty),
867 self.memory.write_usize(dest, len)?;
870 Ref(_, _, ref lvalue) => {
871 let lv = self.eval_lvalue(lvalue)?;
872 self.memory.write_ptr(dest, lv.ptr)?;
874 LvalueExtra::None => {},
875 LvalueExtra::Length(len) => {
876 let len_ptr = dest.offset(self.memory.pointer_size as isize);
877 self.memory.write_usize(len_ptr, len)?;
879 LvalueExtra::DowncastVariant(..) =>
880 panic!("attempted to take a reference to an enum downcast lvalue"),
885 let size = self.type_size(ty);
886 let ptr = self.memory.allocate(size);
887 self.memory.write_ptr(dest, ptr)?;
890 Cast(kind, ref operand, dest_ty) => {
891 let src = self.eval_operand(operand)?;
892 let src_ty = self.operand_ty(operand);
894 use rustc::mir::repr::CastKind::*;
897 self.move_(src, dest, src_ty)?;
898 let src_pointee_ty = pointee_type(src_ty).unwrap();
899 let dest_pointee_ty = pointee_type(dest_ty).unwrap();
901 match (&src_pointee_ty.sty, &dest_pointee_ty.sty) {
902 (&ty::TyArray(_, length), &ty::TySlice(_)) => {
903 let len_ptr = dest.offset(self.memory.pointer_size as isize);
904 self.memory.write_usize(len_ptr, length as u64)?;
907 _ => panic!("can't handle cast: {:?}", rvalue),
912 // FIXME(solson): Wrong for almost everything.
913 let size = dest_layout.size(&self.tcx.data_layout).bytes() as usize;
914 self.memory.copy(src, dest, size)?;
917 _ => panic!("can't handle cast: {:?}", rvalue),
921 Slice { .. } => unimplemented!(),
922 InlineAsm { .. } => unimplemented!(),
928 fn nonnull_offset(&self, ty: Ty<'tcx>, nndiscr: u64, discrfield: &[u32]) -> Size {
929 // Skip the constant 0 at the start meant for LLVM GEP.
930 let mut path = discrfield.iter().skip(1).map(|&i| i as usize);
932 // Handle the field index for the outer non-null variant.
933 let inner_ty = match ty.sty {
934 ty::TyEnum(adt_def, substs) => {
935 let variant = &adt_def.variants[nndiscr as usize];
936 let index = path.next().unwrap();
937 let field = &variant.fields[index];
938 field.ty(self.tcx, substs)
941 "non-enum for StructWrappedNullablePointer: {}",
946 self.field_path_offset(inner_ty, path)
949 fn field_path_offset<I: Iterator<Item = usize>>(&self, mut ty: Ty<'tcx>, path: I) -> Size {
950 let mut offset = Size::from_bytes(0);
952 // Skip the initial 0 intended for LLVM GEP.
953 for field_index in path {
954 let field_offset = self.get_field_offset(ty, field_index);
955 ty = self.get_field_ty(ty, field_index);
956 offset = offset.checked_add(field_offset, &self.tcx.data_layout).unwrap();
962 fn get_field_ty(&self, ty: Ty<'tcx>, field_index: usize) -> Ty<'tcx> {
964 ty::TyStruct(adt_def, substs) => {
965 adt_def.struct_variant().fields[field_index].ty(self.tcx, substs)
968 ty::TyRef(_, ty::TypeAndMut { ty, .. }) |
969 ty::TyRawPtr(ty::TypeAndMut { ty, .. }) |
971 assert_eq!(field_index, 0);
974 _ => panic!("can't handle type: {:?}", ty),
978 fn get_field_offset(&self, ty: Ty<'tcx>, field_index: usize) -> Size {
979 let layout = self.type_layout(ty);
981 use rustc::ty::layout::Layout::*;
983 Univariant { .. } => {
984 assert_eq!(field_index, 0);
987 FatPointer { .. } => {
988 let bytes = layout::FAT_PTR_ADDR * self.memory.pointer_size;
989 Size::from_bytes(bytes as u64)
991 _ => panic!("can't handle type: {:?}, with layout: {:?}", ty, layout),
995 fn eval_operand(&mut self, op: &mir::Operand<'tcx>) -> EvalResult<Pointer> {
996 use rustc::mir::repr::Operand::*;
998 Consume(ref lvalue) => Ok(self.eval_lvalue(lvalue)?.to_ptr()),
999 Constant(mir::Constant { ref literal, .. }) => {
1000 use rustc::mir::repr::Literal::*;
1002 Value { ref value } => Ok(self.const_to_ptr(value)?),
1003 Item { .. } => unimplemented!(),
1004 Promoted { index } => {
1005 // TODO(solson): Mark constants and statics as read-only and cache their
1007 let current_mir = self.mir();
1008 let mir = ¤t_mir.promoted[index];
1009 self.call_nested(mir).map(Option::unwrap)
1016 fn eval_lvalue(&mut self, lvalue: &mir::Lvalue<'tcx>) -> EvalResult<Lvalue> {
1017 use rustc::mir::repr::Lvalue::*;
1018 let ptr = match *lvalue {
1019 ReturnPointer => self.frame().return_ptr
1020 .expect("ReturnPointer used in a function with no return value"),
1021 Arg(i) => self.frame().locals[i as usize],
1022 Var(i) => self.frame().locals[self.frame().var_offset + i as usize],
1023 Temp(i) => self.frame().locals[self.frame().temp_offset + i as usize],
1026 // TODO(solson): Mark constants and statics as read-only and cache their values.
1027 let mir = self.load_mir(def_id);
1028 self.call_nested(&mir)?.unwrap()
1031 Projection(ref proj) => {
1032 let base = self.eval_lvalue(&proj.base)?;
1033 let base_ty = self.lvalue_ty(&proj.base);
1034 let base_layout = self.type_layout(base_ty);
1036 use rustc::mir::repr::ProjectionElem::*;
1038 Field(field, _) => {
1039 use rustc::ty::layout::Layout::*;
1040 let variant = match *base_layout {
1041 Univariant { ref variant, .. } => variant,
1042 General { ref variants, .. } => {
1043 if let LvalueExtra::DowncastVariant(variant_idx) = base.extra {
1044 &variants[variant_idx]
1046 panic!("field access on enum had no variant index");
1049 RawNullablePointer { .. } => {
1050 assert_eq!(field.index(), 0);
1053 StructWrappedNullablePointer { ref nonnull, .. } => nonnull,
1054 _ => panic!("field access on non-product type: {:?}", base_layout),
1057 let offset = variant.field_offset(field.index()).bytes();
1058 base.ptr.offset(offset as isize)
1061 Downcast(_, variant) => {
1062 use rustc::ty::layout::Layout::*;
1063 match *base_layout {
1064 General { discr, .. } => {
1066 ptr: base.ptr.offset(discr.size().bytes() as isize),
1067 extra: LvalueExtra::DowncastVariant(variant),
1070 RawNullablePointer { .. } | StructWrappedNullablePointer { .. } => {
1073 _ => panic!("variant downcast on non-aggregate: {:?}", base_layout),
1078 let pointee_ty = pointee_type(base_ty).expect("Deref of non-pointer");
1079 let ptr = self.memory.read_ptr(base.ptr)?;
1080 let extra = match pointee_ty.sty {
1081 ty::TySlice(_) | ty::TyStr => {
1082 let len_ptr = base.ptr.offset(self.memory.pointer_size as isize);
1083 let len = self.memory.read_usize(len_ptr)?;
1084 LvalueExtra::Length(len)
1086 ty::TyTrait(_) => unimplemented!(),
1087 _ => LvalueExtra::None,
1089 return Ok(Lvalue { ptr: ptr, extra: extra });
1092 Index(ref operand) => {
1093 let elem_size = match base_ty.sty {
1094 ty::TyArray(elem_ty, _) |
1095 ty::TySlice(elem_ty) => self.type_size(elem_ty),
1096 _ => panic!("indexing expected an array or slice, got {:?}", base_ty),
1098 let n_ptr = self.eval_operand(operand)?;
1099 let n = self.memory.read_usize(n_ptr)?;
1100 base.ptr.offset(n as isize * elem_size as isize)
1103 ConstantIndex { .. } => unimplemented!(),
1108 Ok(Lvalue { ptr: ptr, extra: LvalueExtra::None })
1111 // TODO(solson): Try making const_to_primval instead.
1112 fn const_to_ptr(&mut self, const_val: &const_val::ConstVal) -> EvalResult<Pointer> {
1113 use rustc::middle::const_val::ConstVal::*;
1115 Float(_f) => unimplemented!(),
1117 // TODO(solson): Check int constant type.
1118 let ptr = self.memory.allocate(8);
1119 self.memory.write_uint(ptr, int.to_u64_unchecked(), 8)?;
1123 let psize = self.memory.pointer_size;
1124 let static_ptr = self.memory.allocate(s.len());
1125 let ptr = self.memory.allocate(psize * 2);
1126 self.memory.write_bytes(static_ptr, s.as_bytes())?;
1127 self.memory.write_ptr(ptr, static_ptr)?;
1128 self.memory.write_usize(ptr.offset(psize as isize), s.len() as u64)?;
1131 ByteStr(ref bs) => {
1132 let psize = self.memory.pointer_size;
1133 let static_ptr = self.memory.allocate(bs.len());
1134 let ptr = self.memory.allocate(psize);
1135 self.memory.write_bytes(static_ptr, bs)?;
1136 self.memory.write_ptr(ptr, static_ptr)?;
1140 let ptr = self.memory.allocate(1);
1141 self.memory.write_bool(ptr, b)?;
1144 Char(_c) => unimplemented!(),
1145 Struct(_node_id) => unimplemented!(),
1146 Tuple(_node_id) => unimplemented!(),
1147 Function(_def_id) => unimplemented!(),
1148 Array(_, _) => unimplemented!(),
1149 Repeat(_, _) => unimplemented!(),
1150 Dummy => unimplemented!(),
1154 fn lvalue_ty(&self, lvalue: &mir::Lvalue<'tcx>) -> Ty<'tcx> {
1155 self.monomorphize(self.mir().lvalue_ty(self.tcx, lvalue).to_ty(self.tcx))
1158 fn operand_ty(&self, operand: &mir::Operand<'tcx>) -> Ty<'tcx> {
1159 self.monomorphize(self.mir().operand_ty(self.tcx, operand))
1162 fn monomorphize(&self, ty: Ty<'tcx>) -> Ty<'tcx> {
1163 let substituted = ty.subst(self.tcx, self.substs());
1164 self.tcx.normalize_associated_type(&substituted)
1167 fn type_needs_drop(&self, ty: Ty<'tcx>) -> bool {
1168 self.tcx.type_needs_drop_given_env(ty, &self.tcx.empty_parameter_environment())
1171 fn move_(&mut self, src: Pointer, dest: Pointer, ty: Ty<'tcx>) -> EvalResult<()> {
1172 let size = self.type_size(ty);
1173 self.memory.copy(src, dest, size)?;
1174 if self.type_needs_drop(ty) {
1175 self.memory.drop_fill(src, size)?;
1180 fn type_is_sized(&self, ty: Ty<'tcx>) -> bool {
1181 ty.is_sized(self.tcx, &self.tcx.empty_parameter_environment(), DUMMY_SP)
1184 fn type_size(&self, ty: Ty<'tcx>) -> usize {
1185 self.type_layout(ty).size(&self.tcx.data_layout).bytes() as usize
1188 fn type_layout(&self, ty: Ty<'tcx>) -> &'tcx Layout {
1189 // TODO(solson): Is this inefficient? Needs investigation.
1190 let ty = self.monomorphize(ty);
1192 self.tcx.normalizing_infer_ctxt(ProjectionMode::Any).enter(|infcx| {
1193 // TODO(solson): Report this error properly.
1194 ty.layout(&infcx).unwrap()
1198 pub fn read_primval(&mut self, ptr: Pointer, ty: Ty<'tcx>) -> EvalResult<PrimVal> {
1199 use syntax::ast::{IntTy, UintTy};
1200 let val = match ty.sty {
1201 ty::TyBool => PrimVal::Bool(self.memory.read_bool(ptr)?),
1202 ty::TyInt(IntTy::I8) => PrimVal::I8(self.memory.read_int(ptr, 1)? as i8),
1203 ty::TyInt(IntTy::I16) => PrimVal::I16(self.memory.read_int(ptr, 2)? as i16),
1204 ty::TyInt(IntTy::I32) => PrimVal::I32(self.memory.read_int(ptr, 4)? as i32),
1205 ty::TyInt(IntTy::I64) => PrimVal::I64(self.memory.read_int(ptr, 8)? as i64),
1206 ty::TyUint(UintTy::U8) => PrimVal::U8(self.memory.read_uint(ptr, 1)? as u8),
1207 ty::TyUint(UintTy::U16) => PrimVal::U16(self.memory.read_uint(ptr, 2)? as u16),
1208 ty::TyUint(UintTy::U32) => PrimVal::U32(self.memory.read_uint(ptr, 4)? as u32),
1209 ty::TyUint(UintTy::U64) => PrimVal::U64(self.memory.read_uint(ptr, 8)? as u64),
1211 // TODO(solson): Pick the PrimVal dynamically.
1212 ty::TyInt(IntTy::Is) => PrimVal::I64(self.memory.read_isize(ptr)?),
1213 ty::TyUint(UintTy::Us) => PrimVal::U64(self.memory.read_usize(ptr)?),
1215 ty::TyRef(_, ty::TypeAndMut { ty, .. }) |
1216 ty::TyRawPtr(ty::TypeAndMut { ty, .. }) => {
1217 if self.type_is_sized(ty) {
1218 match self.memory.read_ptr(ptr) {
1219 Ok(p) => PrimVal::AbstractPtr(p),
1220 Err(EvalError::ReadBytesAsPointer) => {
1221 PrimVal::IntegerPtr(self.memory.read_usize(ptr)?)
1223 Err(e) => return Err(e),
1226 panic!("unimplemented: primitive read of fat pointer type: {:?}", ty);
1230 _ => panic!("primitive read of non-primitive type: {:?}", ty),
1235 fn frame(&self) -> &Frame<'mir, 'tcx> {
1236 self.stack.last().expect("no call frames exist")
1239 fn frame_mut(&mut self) -> &mut Frame<'mir, 'tcx> {
1240 self.stack.last_mut().expect("no call frames exist")
1243 fn mir(&self) -> CachedMir<'mir, 'tcx> {
1244 self.frame().mir.clone()
1247 fn substs(&self) -> &'tcx Substs<'tcx> {
1248 self.substs_stack.last().cloned().unwrap_or_else(|| self.tcx.mk_substs(Substs::empty()))
1251 fn load_mir(&self, def_id: DefId) -> CachedMir<'mir, 'tcx> {
1252 match self.tcx.map.as_local_node_id(def_id) {
1253 Some(node_id) => CachedMir::Ref(self.mir_map.map.get(&node_id).unwrap()),
1255 let mut mir_cache = self.mir_cache.borrow_mut();
1256 if let Some(mir) = mir_cache.get(&def_id) {
1257 return CachedMir::Owned(mir.clone());
1260 let cs = &self.tcx.sess.cstore;
1261 let mir = cs.maybe_get_item_mir(self.tcx, def_id).unwrap_or_else(|| {
1262 panic!("no mir for {:?}", def_id);
1264 let cached = Rc::new(mir);
1265 mir_cache.insert(def_id, cached.clone());
1266 CachedMir::Owned(cached)
1271 fn fulfill_obligation(&self, trait_ref: ty::PolyTraitRef<'tcx>) -> traits::Vtable<'tcx, ()> {
1272 // Do the initial selection for the obligation. This yields the shallow result we are
1273 // looking for -- that is, what specific impl.
1274 self.tcx.normalizing_infer_ctxt(ProjectionMode::Any).enter(|infcx| {
1275 let mut selcx = traits::SelectionContext::new(&infcx);
1277 let obligation = traits::Obligation::new(
1278 traits::ObligationCause::misc(DUMMY_SP, ast::DUMMY_NODE_ID),
1279 trait_ref.to_poly_trait_predicate(),
1281 let selection = selcx.select(&obligation).unwrap().unwrap();
1283 // Currently, we use a fulfillment context to completely resolve all nested obligations.
1284 // This is because they can inform the inference of the impl's type parameters.
1285 let mut fulfill_cx = traits::FulfillmentContext::new();
1286 let vtable = selection.map(|predicate| {
1287 fulfill_cx.register_predicate_obligation(&infcx, predicate);
1289 infcx.drain_fulfillment_cx_or_panic(DUMMY_SP, &mut fulfill_cx, &vtable)
1293 /// Trait method, which has to be resolved to an impl method.
1294 pub fn trait_method(
1297 substs: &'tcx Substs<'tcx>
1298 ) -> (DefId, &'tcx Substs<'tcx>) {
1299 let method_item = self.tcx.impl_or_trait_item(def_id);
1300 let trait_id = method_item.container().id();
1301 let trait_ref = ty::Binder(substs.to_trait_ref(self.tcx, trait_id));
1302 match self.fulfill_obligation(trait_ref) {
1303 traits::VtableImpl(vtable_impl) => {
1304 let impl_did = vtable_impl.impl_def_id;
1305 let mname = self.tcx.item_name(def_id);
1306 // Create a concatenated set of substitutions which includes those from the impl
1307 // and those from the method:
1308 let impl_substs = vtable_impl.substs.with_method_from(substs);
1309 let substs = self.tcx.mk_substs(impl_substs);
1310 let mth = get_impl_method(self.tcx, impl_did, substs, mname);
1312 (mth.method.def_id, mth.substs)
1315 traits::VtableClosure(vtable_closure) =>
1316 (vtable_closure.closure_def_id, vtable_closure.substs.func_substs),
1318 traits::VtableFnPointer(_fn_ty) => {
1319 let _trait_closure_kind = self.tcx.lang_items.fn_trait_kind(trait_id).unwrap();
1321 // let llfn = trans_fn_pointer_shim(ccx, trait_closure_kind, fn_ty);
1323 // let method_ty = def_ty(tcx, def_id, substs);
1324 // let fn_ptr_ty = match method_ty.sty {
1325 // ty::TyFnDef(_, _, fty) => tcx.mk_ty(ty::TyFnPtr(fty)),
1326 // _ => unreachable!("expected fn item type, found {}",
1329 // Callee::ptr(immediate_rvalue(llfn, fn_ptr_ty))
1332 traits::VtableObject(ref _data) => {
1335 // data: Virtual(traits::get_vtable_index_of_object_method(
1336 // tcx, data, def_id)),
1337 // ty: def_ty(tcx, def_id, substs)
1340 vtable => unreachable!("resolved vtable bad vtable {:?} in trans", vtable),
1345 fn pointee_type(ptr_ty: ty::Ty) -> Option<ty::Ty> {
1347 ty::TyRef(_, ty::TypeAndMut { ty, .. }) |
1348 ty::TyRawPtr(ty::TypeAndMut { ty, .. }) |
1357 fn to_ptr(self) -> Pointer {
1358 assert_eq!(self.extra, LvalueExtra::None);
1363 impl<'mir, 'tcx: 'mir> Deref for CachedMir<'mir, 'tcx> {
1364 type Target = mir::Mir<'tcx>;
1365 fn deref(&self) -> &mir::Mir<'tcx> {
1367 CachedMir::Ref(r) => r,
1368 CachedMir::Owned(ref rc) => rc,
1374 pub struct ImplMethod<'tcx> {
1375 pub method: Rc<ty::Method<'tcx>>,
1376 pub substs: &'tcx Substs<'tcx>,
1377 pub is_provided: bool,
1380 /// Locates the applicable definition of a method, given its name.
1381 pub fn get_impl_method<'a, 'tcx>(
1382 tcx: TyCtxt<'a, 'tcx, 'tcx>,
1384 substs: &'tcx Substs<'tcx>,
1386 ) -> ImplMethod<'tcx> {
1387 assert!(!substs.types.needs_infer());
1389 let trait_def_id = tcx.trait_id_of_impl(impl_def_id).unwrap();
1390 let trait_def = tcx.lookup_trait_def(trait_def_id);
1392 match trait_def.ancestors(impl_def_id).fn_defs(tcx, name).next() {
1393 Some(node_item) => {
1394 let substs = tcx.normalizing_infer_ctxt(ProjectionMode::Any).enter(|infcx| {
1395 let substs = traits::translate_substs(&infcx, impl_def_id,
1396 substs, node_item.node);
1397 tcx.lift(&substs).unwrap_or_else(|| {
1398 bug!("trans::meth::get_impl_method: translate_substs \
1399 returned {:?} which contains inference types/regions",
1404 method: node_item.item,
1406 is_provided: node_item.node.is_from_trait(),
1410 bug!("method {:?} not found in {:?}", name, impl_def_id)
1415 pub fn interpret_start_points<'a, 'tcx>(
1416 tcx: TyCtxt<'a, 'tcx, 'tcx>,
1417 mir_map: &MirMap<'tcx>,
1419 for (&id, mir) in &mir_map.map {
1420 for attr in tcx.map.attrs(id) {
1421 use syntax::attr::AttrMetaMethods;
1422 if attr.check_name("miri_run") {
1423 let item = tcx.map.expect_item(id);
1425 if TRACE_EXECUTION {
1426 println!("Interpreting: {}", item.name);
1429 let mut gecx = GlobalEvalContext::new(tcx, mir_map);
1430 let mut fecx = FnEvalContext::new(&mut gecx);
1431 match fecx.call_nested(mir) {
1432 Ok(Some(return_ptr)) => if TRACE_EXECUTION {
1433 fecx.memory.dump(return_ptr.alloc_id);
1435 Ok(None) => println!("(diverging function returned)"),
1437 // TODO(solson): Detect whether the error was already reported or not.
1438 // tcx.sess.err(&e.to_string());
1442 if TRACE_EXECUTION {
1450 // TODO(solson): Upstream these methods into rustc::ty::layout.
1453 fn size(self) -> Size;
1456 impl IntegerExt for layout::Integer {
1457 fn size(self) -> Size {
1458 use rustc::ty::layout::Integer::*;
1460 I1 | I8 => Size::from_bits(8),
1461 I16 => Size::from_bits(16),
1462 I32 => Size::from_bits(32),
1463 I64 => Size::from_bits(64),
1469 fn field_offset(&self, index: usize) -> Size;
1472 impl StructExt for layout::Struct {
1473 fn field_offset(&self, index: usize) -> Size {
1477 self.offset_after_field[index - 1]