11 impl<'mir, 'tcx> EvalContextExt<'mir, 'tcx> for crate::MiriEvalContext<'mir, 'tcx> {}
12 pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx> {
15 instance: ty::Instance<'tcx>,
16 args: &[OpTy<'tcx, Tag>],
17 dest: Option<PlaceTy<'tcx, Tag>>,
18 ret: Option<mir::BasicBlock>,
19 ) -> InterpResult<'tcx, Option<&'mir mir::Body<'tcx>>> {
20 let this = self.eval_context_mut();
21 trace!("eval_fn_call: {:#?}, {:?}", instance, dest.map(|place| *place));
23 // First, run the common hooks also supported by CTFE.
24 if this.hook_fn(instance, args, dest)? {
25 this.goto_block(ret)?;
28 // There are some more lang items we want to hook that CTFE does not hook (yet).
29 if this.tcx.lang_items().align_offset_fn() == Some(instance.def.def_id()) {
30 let n = this.align_offset(args[0], args[1])?;
31 let dest = dest.unwrap();
32 let n = this.truncate(n, dest.layout);
33 this.write_scalar(Scalar::from_uint(n, dest.layout.size), dest)?;
34 this.goto_block(ret)?;
38 // Try to see if we can do something about foreign items.
39 if this.tcx.is_foreign_item(instance.def_id()) {
40 // An external function that we cannot find MIR for, but we can still run enough
41 // of them to make miri viable.
42 this.emulate_foreign_item(instance.def_id(), args, dest, ret)?;
43 // `goto_block` already handled.
47 // Otherwise, load the MIR.
48 Ok(Some(this.load_mir(instance.def, None)?))
53 ptr_op: OpTy<'tcx, Tag>,
54 align_op: OpTy<'tcx, Tag>
55 ) -> InterpResult<'tcx, u128> {
56 let this = self.eval_context_mut();
58 let req_align = this.force_bits(
59 this.read_scalar(align_op)?.not_undef()?,
63 let ptr_scalar = this.read_scalar(ptr_op)?.not_undef()?;
65 if let Scalar::Ptr(ptr) = ptr_scalar {
66 let cur_align = this.memory().get(ptr.alloc_id)?.align.bytes() as usize;
67 if cur_align < req_align {
68 return Ok(u128::max_value());
72 // if the allocation alignment is at least the required alignment or if the pointer is an
73 // integer, we use the libcore implementation
75 (this.force_bits(ptr_scalar, this.pointer_size())? as *const i8)
76 .align_offset(req_align) as u128