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()) {
32 let ptr = this.read_scalar(args[0])?.not_undef()?.assert_ptr();
33 let align = this.force_bits(
34 this.read_scalar(args[1])?.not_undef()?,
38 let stride = this.memory().get(ptr.alloc_id)?.align.bytes() as usize;
39 // if the allocation alignment is at least the required alignment, we use the
40 // libcore implementation
42 ((stride + ptr.offset.bytes() as usize) as *const ())
43 .align_offset(align) as u128
49 let dest = dest.unwrap();
50 let n = this.truncate(n, dest.layout);
51 this.write_scalar(Scalar::from_uint(n, dest.layout.size), dest)?;
52 this.goto_block(ret)?;
56 // Try to see if we can do something about foreign items.
57 if this.tcx.is_foreign_item(instance.def_id()) {
58 // An external function that we cannot find MIR for, but we can still run enough
59 // of them to make miri viable.
60 this.emulate_foreign_item(instance.def_id(), args, dest, ret)?;
61 // `goto_block` already handled.
65 // Otherwise, load the MIR.
66 Ok(Some(this.load_mir(instance.def, None)?))