deduplicate ty::Instance constructors

8 files changed, 53 insertions, 125 deletions

diff --git a/src/librustc/ty/instance.rs b/src/librustc/ty/instance.rs
index be15b1e3cc9..f0251917074 100644
--- a/src/librustc/ty/instance.rs
+++ b/src/librustc/ty/instance.rs
@@ -4,6 +4,7 @@ use crate::hir::def_id::DefId;
 use crate::ty::{self, Ty, PolyFnSig, TypeFoldable, SubstsRef, TyCtxt};
 use crate::ty::print::{FmtPrinter, Printer};
 use crate::traits;
+use crate::middle::lang_items::DropInPlaceFnLangItem;
 use rustc_target::spec::abi::Abi;
 use rustc_macros::HashStable;
 
@@ -325,11 +326,47 @@ impl<'a, 'b, 'tcx> Instance<'tcx> {
         let actual_kind = substs.closure_kind(def_id, tcx);
 
         match needs_fn_once_adapter_shim(actual_kind, requested_kind) {
-            Ok(true) => fn_once_adapter_instance(tcx, def_id, substs),
+            Ok(true) => Instance::fn_once_adapter_instance(tcx, def_id, substs),
             _ => Instance::new(def_id, substs.substs)
         }
     }
 
+    pub fn resolve_drop_in_place(
+        tcx: TyCtxt<'a, 'tcx, 'tcx>,
+        ty: Ty<'tcx>)
+        -> ty::Instance<'tcx>
+    {
+        let def_id = tcx.require_lang_item(DropInPlaceFnLangItem);
+        let substs = tcx.intern_substs(&[ty.into()]);
+        Instance::resolve(tcx, ty::ParamEnv::reveal_all(), def_id, substs).unwrap()
+    }
+
+    pub fn fn_once_adapter_instance(
+        tcx: TyCtxt<'a, 'tcx, 'tcx>,
+        closure_did: DefId,
+        substs: ty::ClosureSubsts<'tcx>)
+        -> Instance<'tcx>
+    {
+        debug!("fn_once_adapter_shim({:?}, {:?})",
+               closure_did,
+               substs);
+        let fn_once = tcx.lang_items().fn_once_trait().unwrap();
+        let call_once = tcx.associated_items(fn_once)
+            .find(|it| it.kind == ty::AssocKind::Method)
+            .unwrap().def_id;
+        let def = ty::InstanceDef::ClosureOnceShim { call_once };
+
+        let self_ty = tcx.mk_closure(closure_did, substs);
+
+        let sig = substs.closure_sig(closure_did, tcx);
+        let sig = tcx.normalize_erasing_late_bound_regions(ty::ParamEnv::reveal_all(), &sig);
+        assert_eq!(sig.inputs().len(), 1);
+        let substs = tcx.mk_substs_trait(self_ty, &[sig.inputs()[0].into()]);
+
+        debug!("fn_once_adapter_shim: self_ty={:?} sig={:?}", self_ty, sig);
+        Instance { def, substs }
+    }
+
     pub fn is_vtable_shim(&self) -> bool {
         if let InstanceDef::VtableShim(..) = self.def {
             true
@@ -438,29 +475,3 @@ fn needs_fn_once_adapter_shim<'a, 'tcx>(actual_closure_kind: ty::ClosureKind,
         (ty::ClosureKind::FnOnce, _) => Err(())
     }
 }
-
-fn fn_once_adapter_instance<'a, 'tcx>(
-    tcx: TyCtxt<'a, 'tcx, 'tcx>,
-    closure_did: DefId,
-    substs: ty::ClosureSubsts<'tcx>)
-    -> Instance<'tcx>
-{
-    debug!("fn_once_adapter_shim({:?}, {:?})",
-           closure_did,
-           substs);
-    let fn_once = tcx.lang_items().fn_once_trait().unwrap();
-    let call_once = tcx.associated_items(fn_once)
-        .find(|it| it.kind == ty::AssocKind::Method)
-        .unwrap().def_id;
-    let def = ty::InstanceDef::ClosureOnceShim { call_once };
-
-    let self_ty = tcx.mk_closure(closure_did, substs);
-
-    let sig = substs.closure_sig(closure_did, tcx);
-    let sig = tcx.normalize_erasing_late_bound_regions(ty::ParamEnv::reveal_all(), &sig);
-    assert_eq!(sig.inputs().len(), 1);
-    let substs = tcx.mk_substs_trait(self_ty, &[sig.inputs()[0].into()]);
-
-    debug!("fn_once_adapter_shim: self_ty={:?} sig={:?}", self_ty, sig);
-    Instance { def, substs }
-}
diff --git a/src/librustc_codegen_ssa/meth.rs b/src/librustc_codegen_ssa/meth.rs
index 49f3c87ee2d..73065be9970 100644
--- a/src/librustc_codegen_ssa/meth.rs
+++ b/src/librustc_codegen_ssa/meth.rs
@@ -4,7 +4,7 @@ use rustc_mir::monomorphize;
 use crate::callee;
 use crate::traits::*;
 
-use rustc::ty::{self, Ty};
+use rustc::ty::{self, Ty, Instance};
 
 #[derive(Copy, Clone, Debug)]
 pub struct VirtualIndex(u64);
@@ -103,7 +103,7 @@ pub fn get_vtable<'tcx, Cx: CodegenMethods<'tcx>>(
     // `get_vtable` in rust_mir/interpret/traits.rs
     // /////////////////////////////////////////////////////////////////////////////////////////////
     let components: Vec<_> = [
-        cx.get_fn(monomorphize::resolve_drop_in_place(cx.tcx(), ty)),
+        cx.get_fn(Instance::resolve_drop_in_place(cx.tcx(), ty)),
         cx.const_usize(layout.size.bytes()),
         cx.const_usize(layout.align.abi.bytes())
     ].iter().cloned().chain(methods).collect();
diff --git a/src/librustc_codegen_ssa/mir/block.rs b/src/librustc_codegen_ssa/mir/block.rs
index c7dd019fc3e..f2d4cd33229 100644
--- a/src/librustc_codegen_ssa/mir/block.rs
+++ b/src/librustc_codegen_ssa/mir/block.rs
@@ -1,5 +1,5 @@
 use rustc::middle::lang_items;
-use rustc::ty::{self, Ty, TypeFoldable};
+use rustc::ty::{self, Ty, TypeFoldable, Instance};
 use rustc::ty::layout::{self, LayoutOf, HasTyCtxt, FnTypeExt};
 use rustc::mir::{self, Place, PlaceBase, Static, StaticKind};
 use rustc::mir::interpret::InterpError;
@@ -310,7 +310,7 @@ impl<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
     ) {
         let ty = location.ty(self.mir, bx.tcx()).ty;
         let ty = self.monomorphize(&ty);
-        let drop_fn = monomorphize::resolve_drop_in_place(bx.tcx(), ty);
+        let drop_fn = Instance::resolve_drop_in_place(bx.tcx(), ty);
 
         if let ty::InstanceDef::DropGlue(_, None) = drop_fn.def {
             // we don't actually need to drop anything.
diff --git a/src/librustc_codegen_ssa/mir/rvalue.rs b/src/librustc_codegen_ssa/mir/rvalue.rs
index 586db5cfabe..b11fe236833 100644
--- a/src/librustc_codegen_ssa/mir/rvalue.rs
+++ b/src/librustc_codegen_ssa/mir/rvalue.rs
@@ -1,4 +1,4 @@
-use rustc::ty::{self, Ty, adjustment::{PointerCast}};
+use rustc::ty::{self, Ty, adjustment::{PointerCast}, Instance};
 use rustc::ty::cast::{CastTy, IntTy};
 use rustc::ty::layout::{self, LayoutOf, HasTyCtxt};
 use rustc::mir;
@@ -196,7 +196,7 @@ impl<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                     mir::CastKind::Pointer(PointerCast::ClosureFnPointer(_)) => {
                         match operand.layout.ty.sty {
                             ty::Closure(def_id, substs) => {
-                                let instance = monomorphize::resolve_closure(
+                                let instance = Instance::resolve_closure(
                                     bx.cx().tcx(), def_id, substs, ty::ClosureKind::FnOnce);
                                 OperandValue::Immediate(bx.cx().get_fn(instance))
                             }
diff --git a/src/librustc_mir/interpret/terminator.rs b/src/librustc_mir/interpret/terminator.rs
index ba48a28fc83..a39af9640ac 100644
--- a/src/librustc_mir/interpret/terminator.rs
+++ b/src/librustc_mir/interpret/terminator.rs
@@ -1,6 +1,7 @@
 use std::borrow::Cow;
 
 use rustc::{mir, ty};
+use rustc::ty::Instance;
 use rustc::ty::layout::{self, TyLayout, LayoutOf};
 use syntax::source_map::Span;
 use rustc_target::spec::abi::Abi;
@@ -112,7 +113,7 @@ impl<'a, 'mir, 'tcx, M: Machine<'a, 'mir, 'tcx>> InterpretCx<'a, 'mir, 'tcx, M>
                 let ty = place.layout.ty;
                 trace!("TerminatorKind::drop: {:?}, type {}", location, ty);
 
-                let instance = crate::monomorphize::resolve_drop_in_place(*self.tcx, ty);
+                let instance = Instance::resolve_drop_in_place(*self.tcx, ty);
                 self.drop_in_place(
                     place,
                     instance,
diff --git a/src/librustc_mir/interpret/traits.rs b/src/librustc_mir/interpret/traits.rs
index 208bba60bf2..33cb1a09717 100644
--- a/src/librustc_mir/interpret/traits.rs
+++ b/src/librustc_mir/interpret/traits.rs
@@ -1,4 +1,4 @@
-use rustc::ty::{self, Ty};
+use rustc::ty::{self, Ty, Instance};
 use rustc::ty::layout::{Size, Align, LayoutOf};
 use rustc::mir::interpret::{Scalar, Pointer, EvalResult, PointerArithmetic};
 
@@ -55,8 +55,9 @@ impl<'a, 'mir, 'tcx, M: Machine<'a, 'mir, 'tcx>> InterpretCx<'a, 'mir, 'tcx, M>
         );
         let tcx = &*self.tcx;
 
-        let drop = crate::monomorphize::resolve_drop_in_place(*tcx, ty);
+        let drop = Instance::resolve_drop_in_place(*tcx, ty);
         let drop = self.memory.create_fn_alloc(drop);
+
         // no need to do any alignment checks on the memory accesses below, because we know the
         // allocation is correctly aligned as we created it above. Also we're only offsetting by
         // multiples of `ptr_align`, which means that it will stay aligned to `ptr_align`.
diff --git a/src/librustc_mir/monomorphize/collector.rs b/src/librustc_mir/monomorphize/collector.rs
index dae5f1b8cd2..b808f64b007 100644
--- a/src/librustc_mir/monomorphize/collector.rs
+++ b/src/librustc_mir/monomorphize/collector.rs
@@ -181,7 +181,7 @@ use rustc::hir::def_id::{DefId, LOCAL_CRATE};
 use rustc::mir::interpret::{AllocId, ConstValue};
 use rustc::middle::lang_items::{ExchangeMallocFnLangItem, StartFnLangItem};
 use rustc::ty::subst::{InternalSubsts, SubstsRef};
-use rustc::ty::{self, TypeFoldable, Ty, TyCtxt, GenericParamDefKind};
+use rustc::ty::{self, TypeFoldable, Ty, TyCtxt, GenericParamDefKind, Instance};
 use rustc::ty::adjustment::{CustomCoerceUnsized, PointerCast};
 use rustc::session::config::EntryFnType;
 use rustc::mir::{self, Location, Place, PlaceBase, Promoted, Static, StaticKind};
@@ -189,7 +189,7 @@ use rustc::mir::visit::Visitor as MirVisitor;
 use rustc::mir::mono::MonoItem;
 use rustc::mir::interpret::{Scalar, GlobalId, GlobalAlloc, ErrorHandled};
 
-use crate::monomorphize::{self, Instance};
+use crate::monomorphize;
 use rustc::util::nodemap::{FxHashSet, FxHashMap, DefIdMap};
 use rustc::util::common::time;
 
@@ -580,7 +580,7 @@ impl<'a, 'tcx> MirVisitor<'tcx> for MirNeighborCollector<'a, 'tcx> {
                 );
                 match source_ty.sty {
                     ty::Closure(def_id, substs) => {
-                        let instance = monomorphize::resolve_closure(
+                        let instance = Instance::resolve_closure(
                             self.tcx, def_id, substs, ty::ClosureKind::FnOnce);
                         if should_monomorphize_locally(self.tcx, &instance) {
                             self.output.push(create_fn_mono_item(instance));
@@ -684,7 +684,7 @@ fn visit_drop_use<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
                             is_direct_call: bool,
                             output: &mut Vec<MonoItem<'tcx>>)
 {
-    let instance = monomorphize::resolve_drop_in_place(tcx, ty);
+    let instance = Instance::resolve_drop_in_place(tcx, ty);
     visit_instance_use(tcx, instance, is_direct_call, output);
 }
 
diff --git a/src/librustc_mir/monomorphize/mod.rs b/src/librustc_mir/monomorphize/mod.rs
index 5cf03a6a35b..8dda352d5e6 100644
--- a/src/librustc_mir/monomorphize/mod.rs
+++ b/src/librustc_mir/monomorphize/mod.rs
@@ -1,5 +1,3 @@
-use rustc::hir::def_id::DefId;
-use rustc::middle::lang_items::DropInPlaceFnLangItem;
 use rustc::traits;
 use rustc::ty::adjustment::CustomCoerceUnsized;
 use rustc::ty::{self, Ty, TyCtxt, Instance};
@@ -54,89 +52,6 @@ pub fn assert_symbols_are_distinct<'a, 'tcx, I>(tcx: TyCtxt<'a, 'tcx, 'tcx>, mon
     }
 }
 
-fn fn_once_adapter_instance<'a, 'tcx>(
-    tcx: TyCtxt<'a, 'tcx, 'tcx>,
-    closure_did: DefId,
-    substs: ty::ClosureSubsts<'tcx>,
-    ) -> Instance<'tcx> {
-    debug!("fn_once_adapter_shim({:?}, {:?})",
-           closure_did,
-           substs);
-    let fn_once = tcx.lang_items().fn_once_trait().unwrap();
-    let call_once = tcx.associated_items(fn_once)
-        .find(|it| it.kind == ty::AssocKind::Method)
-        .unwrap().def_id;
-    let def = ty::InstanceDef::ClosureOnceShim { call_once };
-
-    let self_ty = tcx.mk_closure(closure_did, substs);
-
-    let sig = substs.closure_sig(closure_did, tcx);
-    let sig = tcx.normalize_erasing_late_bound_regions(ty::ParamEnv::reveal_all(), &sig);
-    assert_eq!(sig.inputs().len(), 1);
-    let substs = tcx.mk_substs_trait(self_ty, &[sig.inputs()[0].into()]);
-
-    debug!("fn_once_adapter_shim: self_ty={:?} sig={:?}", self_ty, sig);
-    Instance { def, substs }
-}
-
-fn needs_fn_once_adapter_shim(actual_closure_kind: ty::ClosureKind,
-                              trait_closure_kind: ty::ClosureKind)
-                              -> Result<bool, ()>
-{
-    match (actual_closure_kind, trait_closure_kind) {
-        (ty::ClosureKind::Fn, ty::ClosureKind::Fn) |
-        (ty::ClosureKind::FnMut, ty::ClosureKind::FnMut) |
-        (ty::ClosureKind::FnOnce, ty::ClosureKind::FnOnce) => {
-            // No adapter needed.
-           Ok(false)
-        }
-        (ty::ClosureKind::Fn, ty::ClosureKind::FnMut) => {
-            // The closure fn `llfn` is a `fn(&self, ...)`.  We want a
-            // `fn(&mut self, ...)`. In fact, at codegen time, these are
-            // basically the same thing, so we can just return llfn.
-            Ok(false)
-        }
-        (ty::ClosureKind::Fn, ty::ClosureKind::FnOnce) |
-        (ty::ClosureKind::FnMut, ty::ClosureKind::FnOnce) => {
-            // The closure fn `llfn` is a `fn(&self, ...)` or `fn(&mut
-            // self, ...)`.  We want a `fn(self, ...)`. We can produce
-            // this by doing something like:
-            //
-            //     fn call_once(self, ...) { call_mut(&self, ...) }
-            //     fn call_once(mut self, ...) { call_mut(&mut self, ...) }
-            //
-            // These are both the same at codegen time.
-            Ok(true)
-        }
-        _ => Err(()),
-    }
-}
-
-pub fn resolve_closure<'a, 'tcx> (
-    tcx: TyCtxt<'a, 'tcx, 'tcx>,
-    def_id: DefId,
-    substs: ty::ClosureSubsts<'tcx>,
-    requested_kind: ty::ClosureKind)
-    -> Instance<'tcx>
-{
-    let actual_kind = substs.closure_kind(def_id, tcx);
-
-    match needs_fn_once_adapter_shim(actual_kind, requested_kind) {
-        Ok(true) => fn_once_adapter_instance(tcx, def_id, substs),
-        _ => Instance::new(def_id, substs.substs)
-    }
-}
-
-pub fn resolve_drop_in_place<'a, 'tcx>(
-    tcx: TyCtxt<'a, 'tcx, 'tcx>,
-    ty: Ty<'tcx>)
-    -> ty::Instance<'tcx>
-{
-    let def_id = tcx.require_lang_item(DropInPlaceFnLangItem);
-    let substs = tcx.intern_substs(&[ty.into()]);
-    Instance::resolve(tcx, ty::ParamEnv::reveal_all(), def_id, substs).unwrap()
-}
-
 pub fn custom_coerce_unsize_info<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
                                            source_ty: Ty<'tcx>,
                                            target_ty: Ty<'tcx>)