13 impl<'mir, 'tcx> EvalContextExt<'mir, 'tcx> for crate::MiriEvalContext<'mir, 'tcx> {}
14 pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx> {
17 instance: ty::Instance<'tcx>,
18 args: &[OpTy<'tcx, Tag>],
19 dest: Option<PlaceTy<'tcx, Tag>>,
20 ret: Option<mir::BasicBlock>,
21 unwind: Option<mir::BasicBlock>
22 ) -> InterpResult<'tcx, Option<&'mir mir::Body<'tcx>>> {
23 let this = self.eval_context_mut();
25 "eval_fn_call: {:#?}, {:?}",
27 dest.map(|place| *place)
30 // There are some more lang items we want to hook that CTFE does not hook (yet).
31 if this.tcx.lang_items().align_offset_fn() == Some(instance.def.def_id()) {
32 let dest = dest.unwrap();
34 .align_offset(args[0], args[1])?
35 .unwrap_or_else(|| this.truncate(u128::max_value(), dest.layout));
36 this.write_scalar(Scalar::from_uint(n, dest.layout.size), dest)?;
37 this.goto_block(ret)?;
41 // Try to see if we can do something about foreign items.
42 if this.tcx.is_foreign_item(instance.def_id()) {
43 // An external function call that does not have a MIR body. We either find MIR elsewhere
44 // or emulate its effect.
45 // This will be Ok(None) if we're emulating the intrinsic entirely within Miri (no need
46 // to run extra MIR), and Ok(Some(body)) if we found MIR to run for the
48 // Any needed call to `goto_block` will be performed by `emulate_foreign_item`.
49 return this.emulate_foreign_item(instance.def_id(), args, dest, ret, unwind);
52 // Otherwise, load the MIR.
53 Ok(Some(this.load_mir(instance.def, None)?))
58 ptr_op: OpTy<'tcx, Tag>,
59 align_op: OpTy<'tcx, Tag>,
60 ) -> InterpResult<'tcx, Option<u128>> {
61 let this = self.eval_context_mut();
63 let req_align = this.force_bits(
64 this.read_scalar(align_op)?.not_undef()?,
68 // FIXME: This should actually panic in the interpreted program
69 if !req_align.is_power_of_two() {
70 throw_unsup_format!("Required alignment should always be a power of two")
73 let ptr_scalar = this.read_scalar(ptr_op)?.not_undef()?;
75 if let Ok(ptr) = this.force_ptr(ptr_scalar) {
76 let cur_align = this.memory.get_size_and_align(ptr.alloc_id, AllocCheck::MaybeDead)?.1.bytes() as usize;
77 if cur_align >= req_align {
78 // if the allocation alignment is at least the required alignment we use the
79 // libcore implementation
81 (this.force_bits(ptr_scalar, this.pointer_size())? as *const i8)
82 .align_offset(req_align) as u128,
86 // If the allocation alignment is smaller than then required alignment or the pointer was
87 // actually an integer, we return `None`