Auto merge of #814 - RalfJung:shims, r=RalfJung

move find_fn (which is not specific to foreign items) out of foreign_item

Author: bors

src/lib.rs

@@ -28,6 +28,7 @@ pub use rustc_mir::interpret::*;
 // Resolve ambiguity.
 pub use rustc_mir::interpret::{self, AllocMap, PlaceTy};
 
+pub use crate::shims::{EvalContextExt as ShimsEvalContextExt};
 pub use crate::shims::foreign_items::EvalContextExt as ForeignItemsEvalContextExt;
 pub use crate::shims::intrinsics::EvalContextExt as IntrinsicsEvalContextExt;
 pub use crate::operator::EvalContextExt as OperatorEvalContextExt;

src/shims/foreign_items.rs

@@ -1,4 +1,3 @@
-use rustc::ty;
 use rustc::ty::layout::{Align, LayoutOf, Size};
 use rustc::hir::def_id::DefId;
 use rustc::mir;
@@ -11,46 +10,6 @@ use crate::*;
 
 impl<'mir, 'tcx> EvalContextExt<'mir, 'tcx> for crate::MiriEvalContext<'mir, 'tcx> {}
 pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx> {
- fn find_fn(
- &mut self,
- instance: ty::Instance<'tcx>,
- args: &[OpTy<'tcx, Tag>],
- dest: Option<PlaceTy<'tcx, Tag>>,
- ret: Option<mir::BasicBlock>,
- ) -> InterpResult<'tcx, Option<&'mir mir::Body<'tcx>>> {
- let this = self.eval_context_mut();
- trace!("eval_fn_call: {:#?}, {:?}", instance, dest.map(|place| *place));
-
- // First, run the common hooks also supported by CTFE.
- if this.hook_fn(instance, args, dest)? {
- this.goto_block(ret)?;
- return Ok(None);
- }
- // There are some more lang items we want to hook that CTFE does not hook (yet).
- if this.tcx.lang_items().align_offset_fn() == Some(instance.def.def_id()) {
- // FIXME: return a real value in case the target allocation has an
- // alignment bigger than the one requested.
- let n = u128::max_value();
- let dest = dest.unwrap();
- let n = this.truncate(n, dest.layout);
- this.write_scalar(Scalar::from_uint(n, dest.layout.size), dest)?;
- this.goto_block(ret)?;
- return Ok(None);
- }
-
- // Try to see if we can do something about foreign items.
- if this.tcx.is_foreign_item(instance.def_id()) {
- // An external function that we cannot find MIR for, but we can still run enough
- // of them to make miri viable.
- this.emulate_foreign_item(instance.def_id(), args, dest, ret)?;
- // `goto_block` already handled.
- return Ok(None);
- }
-
- // Otherwise, load the MIR.
- Ok(Some(this.load_mir(instance.def)?))
- }
-
  /// Returns the minimum alignment for the target architecture.
  fn min_align(&self) -> Align {
  let this = self.eval_context_ref();

src/shims/mod.rs

@@ -1,2 +1,49 @@
 pub mod foreign_items;
 pub mod intrinsics;
+
+use rustc::{ty, mir};
+
+use crate::*;
+
+impl<'mir, 'tcx> EvalContextExt<'mir, 'tcx> for crate::MiriEvalContext<'mir, 'tcx> {}
+pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx> {
+ fn find_fn(
+ &mut self,
+ instance: ty::Instance<'tcx>,
+ args: &[OpTy<'tcx, Tag>],
+ dest: Option<PlaceTy<'tcx, Tag>>,
+ ret: Option<mir::BasicBlock>,
+ ) -> InterpResult<'tcx, Option<&'mir mir::Body<'tcx>>> {
+ let this = self.eval_context_mut();
+ trace!("eval_fn_call: {:#?}, {:?}", instance, dest.map(|place| *place));
+
+ // First, run the common hooks also supported by CTFE.
+ if this.hook_fn(instance, args, dest)? {
+ this.goto_block(ret)?;
+ return Ok(None);
+ }
+ // There are some more lang items we want to hook that CTFE does not hook (yet).
+ if this.tcx.lang_items().align_offset_fn() == Some(instance.def.def_id()) {
+ // FIXME: return a real value in case the target allocation has an
+ // alignment bigger than the one requested.
+ let n = u128::max_value();
+ let dest = dest.unwrap();
+ let n = this.truncate(n, dest.layout);
+ this.write_scalar(Scalar::from_uint(n, dest.layout.size), dest)?;
+ this.goto_block(ret)?;
+ return Ok(None);
+ }
+
+ // Try to see if we can do something about foreign items.
+ if this.tcx.is_foreign_item(instance.def_id()) {
+ // An external function that we cannot find MIR for, but we can still run enough
+ // of them to make miri viable.
+ this.emulate_foreign_item(instance.def_id(), args, dest, ret)?;
+ // `goto_block` already handled.
+ return Ok(None);
+ }
+
+ // Otherwise, load the MIR.
+ Ok(Some(this.load_mir(instance.def)?))
+ }
+}