auto merge of #18144 : bkoropoff/rust/mighty-monomorphizin-unboxed-closures, r=nikomatsakis

This allows unboxed closures that reference free type/region parameters to be monomorphized correctly in trans.

It was necessary to make `ty_unboxed_closure` carry around a `Substs` to accomplish this.  Plumbing this through typeck revealed several areas where type/region parameters in unboxed closure types are possibly not being handled correctly.  Since my goal was just to fix trans, I decided to leave FIXME comments on areas that still need attention and seek feedback on the best way to clean them up, possibly as a follow-up PR.

Closes #16791

Author: bors

src/librustc/metadata/tydecode.rs

@@ -465,9 +465,12 @@ fn parse_ty(st: &mut PState, conv: conv_did) -> ty::t {
           return ty::mk_struct(st.tcx, did, substs);
       }
       'k' => {
+          assert_eq!(next(st), '[');
           let did = parse_def(st, NominalType, |x,y| conv(x,y));
-          let region = parse_region(st, conv);
-          return ty::mk_unboxed_closure(st.tcx, did, region);
+          let region = parse_region(st, |x,y| conv(x,y));
+          let substs = parse_substs(st, |x,y| conv(x,y));
+          assert_eq!(next(st), ']');
+          return ty::mk_unboxed_closure(st.tcx, did, region, substs);
       }
       'e' => {
           return ty::mk_err();

src/librustc/metadata/tyencode.rs

@@ -285,9 +285,11 @@ fn enc_sty(w: &mut SeekableMemWriter, cx: &ctxt, st: &ty::sty) {
             enc_substs(w, cx, substs);
             mywrite!(w, "]");
         }
-        ty::ty_unboxed_closure(def, region) => {
-            mywrite!(w, "k{}", (cx.ds)(def));
+        ty::ty_unboxed_closure(def, region, ref substs) => {
+            mywrite!(w, "k[{}|", (cx.ds)(def));
             enc_region(w, cx, region);
+            enc_substs(w, cx, substs);
+            mywrite!(w, "]");
         }
         ty::ty_err => {
             mywrite!(w, "e");

src/librustc/middle/mem_categorization.rs

@@ -594,7 +594,7 @@ impl<'t,'tcx,TYPER:Typer<'tcx>> MemCategorizationContext<'t,TYPER> {
                       };
                       self.cat_upvar(id, span, var_id, fn_node_id, kind, mode, false)
                   }
-                  ty::ty_unboxed_closure(closure_id, _) => {
+                  ty::ty_unboxed_closure(closure_id, _, _) => {
                       let unboxed_closures = self.typer.unboxed_closures().borrow();
                       let kind = (*unboxed_closures)[closure_id].kind;
                       let mode = self.typer.capture_mode(fn_node_id);

src/librustc/middle/traits/select.rs

@@ -110,7 +110,7 @@ enum Candidate {
     BuiltinCandidate(ty::BuiltinBound),
     ParamCandidate(VtableParamData),
     ImplCandidate(ast::DefId),
-    UnboxedClosureCandidate(/* closure */ ast::DefId),
+    UnboxedClosureCandidate(/* closure */ ast::DefId, Substs),
     ErrorCandidate,
 }
 
@@ -995,8 +995,8 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
         };
 
         let self_ty = self.infcx.shallow_resolve(obligation.self_ty());
-        let closure_def_id = match ty::get(self_ty).sty {
-            ty::ty_unboxed_closure(id, _) => id,
+        let (closure_def_id, substs) = match ty::get(self_ty).sty {
+            ty::ty_unboxed_closure(id, _, ref substs) => (id, substs.clone()),
             ty::ty_infer(ty::TyVar(_)) => {
                 candidates.ambiguous = true;
                 return Ok(());
@@ -1019,7 +1019,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
         };
 
         if closure_kind == kind {
-            candidates.vec.push(UnboxedClosureCandidate(closure_def_id));
+            candidates.vec.push(UnboxedClosureCandidate(closure_def_id, substs.clone()));
         }
 
         Ok(())
@@ -1383,7 +1383,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                 Ok(If(tys.clone()))
             }
 
-            ty::ty_unboxed_closure(def_id, _) => {
+            ty::ty_unboxed_closure(def_id, _, ref substs) => {
                 // FIXME -- This case is tricky. In the case of by-ref
                 // closures particularly, we need the results of
                 // inference to decide how to reflect the type of each
@@ -1407,7 +1407,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                             .map(|freevar| {
                                 let freevar_def_id = freevar.def.def_id();
                                 self.typer.node_ty(freevar_def_id.node)
-                                    .unwrap_or(ty::mk_err())
+                                    .unwrap_or(ty::mk_err()).subst(self.tcx(), substs)
                             })
                             .collect();
                         Ok(If(tys))
@@ -1548,8 +1548,8 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                 Ok(VtableImpl(vtable_impl))
             }
 
-            UnboxedClosureCandidate(closure_def_id) => {
-                try!(self.confirm_unboxed_closure_candidate(obligation, closure_def_id));
+            UnboxedClosureCandidate(closure_def_id, ref substs) => {
+                try!(self.confirm_unboxed_closure_candidate(obligation, closure_def_id, substs));
                 Ok(VtableUnboxedClosure(closure_def_id))
             }
         }
@@ -1646,12 +1646,14 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
 
     fn confirm_unboxed_closure_candidate(&mut self,
                                          obligation: &Obligation,
-                                         closure_def_id: ast::DefId)
+                                         closure_def_id: ast::DefId,
+                                         substs: &Substs)
                                          -> Result<(),SelectionError>
     {
-        debug!("confirm_unboxed_closure_candidate({},{})",
+        debug!("confirm_unboxed_closure_candidate({},{},{})",
                obligation.repr(self.tcx()),
-               closure_def_id.repr(self.tcx()));
+               closure_def_id.repr(self.tcx()),
+               substs.repr(self.tcx()));
 
         let closure_type = match self.typer.unboxed_closures().borrow().find(&closure_def_id) {
             Some(closure) => closure.closure_type.clone(),
@@ -1678,7 +1680,8 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
         let trait_ref = Rc::new(ty::TraitRef {
             def_id: obligation.trait_ref.def_id,
             substs: Substs::new_trait(
-                vec![arguments_tuple, new_signature.output],
+                vec![arguments_tuple.subst(self.tcx(), substs),
+                     new_signature.output.subst(self.tcx(), substs)],
                 vec![],
                 obligation.self_ty())
         });
@@ -1959,7 +1962,9 @@ impl Repr for Candidate {
         match *self {
             ErrorCandidate => format!("ErrorCandidate"),
             BuiltinCandidate(b) => format!("BuiltinCandidate({})", b),
-            UnboxedClosureCandidate(c) => format!("MatchedUnboxedClosureCandidate({})", c),
+            UnboxedClosureCandidate(c, ref s) => {
+                format!("MatchedUnboxedClosureCandidate({},{})", c, s.repr(tcx))
+            }
             ParamCandidate(ref a) => format!("ParamCandidate({})", a.repr(tcx)),
             ImplCandidate(a) => format!("ImplCandidate({})", a.repr(tcx)),
         }

src/librustc/middle/trans/adt.rs

@@ -176,8 +176,8 @@ fn represent_type_uncached(cx: &CrateContext, t: ty::t) -> Repr {
 
             return Univariant(mk_struct(cx, ftys.as_slice(), packed, t), dtor)
         }
-        ty::ty_unboxed_closure(def_id, _) => {
-            let upvars = ty::unboxed_closure_upvars(cx.tcx(), def_id);
+        ty::ty_unboxed_closure(def_id, _, ref substs) => {
+            let upvars = ty::unboxed_closure_upvars(cx.tcx(), def_id, substs);
             let upvar_types = upvars.iter().map(|u| u.ty).collect::<Vec<_>>();
             return Univariant(mk_struct(cx, upvar_types.as_slice(), false, t),
                               false)

src/librustc/middle/trans/base.rs

@@ -253,21 +253,19 @@ fn get_extern_rust_fn(ccx: &CrateContext, fn_ty: ty::t, name: &str, did: ast::De
 }
 
 pub fn self_type_for_unboxed_closure(ccx: &CrateContext,
-                                     closure_id: ast::DefId)
+                                     closure_id: ast::DefId,
+                                     fn_ty: ty::t)
                                      -> ty::t {
-    let unboxed_closure_type = ty::mk_unboxed_closure(ccx.tcx(),
-                                                      closure_id,
-                                                      ty::ReStatic);
     let unboxed_closures = ccx.tcx().unboxed_closures.borrow();
     let unboxed_closure = &(*unboxed_closures)[closure_id];
     match unboxed_closure.kind {
         ty::FnUnboxedClosureKind => {
-            ty::mk_imm_rptr(ccx.tcx(), ty::ReStatic, unboxed_closure_type)
+            ty::mk_imm_rptr(ccx.tcx(), ty::ReStatic, fn_ty)
         }
         ty::FnMutUnboxedClosureKind => {
-            ty::mk_mut_rptr(ccx.tcx(), ty::ReStatic, unboxed_closure_type)
+            ty::mk_mut_rptr(ccx.tcx(), ty::ReStatic, fn_ty)
         }
-        ty::FnOnceUnboxedClosureKind => unboxed_closure_type,
+        ty::FnOnceUnboxedClosureKind => fn_ty
     }
 }
 
@@ -285,14 +283,14 @@ pub fn decl_rust_fn(ccx: &CrateContext, fn_ty: ty::t, name: &str) -> ValueRef {
         ty::ty_closure(ref f) => {
             (f.sig.inputs.clone(), f.sig.output, f.abi, Some(Type::i8p(ccx)))
         }
-        ty::ty_unboxed_closure(closure_did, _) => {
+        ty::ty_unboxed_closure(closure_did, _, ref substs) => {
             let unboxed_closures = ccx.tcx().unboxed_closures.borrow();
             let unboxed_closure = &(*unboxed_closures)[closure_did];
             let function_type = unboxed_closure.closure_type.clone();
-            let self_type = self_type_for_unboxed_closure(ccx, closure_did);
+            let self_type = self_type_for_unboxed_closure(ccx, closure_did, fn_ty);
             let llenvironment_type = type_of_explicit_arg(ccx, self_type);
-            (function_type.sig.inputs.clone(),
-             function_type.sig.output,
+            (function_type.sig.inputs.iter().map(|t| t.subst(ccx.tcx(), substs)).collect(),
+             function_type.sig.output.subst(ccx.tcx(), substs),
              RustCall,
              Some(llenvironment_type))
         }
@@ -738,9 +736,9 @@ pub fn iter_structural_ty<'a, 'blk, 'tcx>(cx: Block<'blk, 'tcx>,
               }
           })
       }
-      ty::ty_unboxed_closure(def_id, _) => {
+      ty::ty_unboxed_closure(def_id, _, ref substs) => {
           let repr = adt::represent_type(cx.ccx(), t);
-          let upvars = ty::unboxed_closure_upvars(cx.tcx(), def_id);
+          let upvars = ty::unboxed_closure_upvars(cx.tcx(), def_id, substs);
           for (i, upvar) in upvars.iter().enumerate() {
               let llupvar = adt::trans_field_ptr(cx, &*repr, data_ptr, 0, i);
               cx = f(cx, llupvar, upvar.ty);
@@ -2351,12 +2349,12 @@ pub fn get_fn_llvm_attributes(ccx: &CrateContext, fn_ty: ty::t)
     let (fn_sig, abi, has_env) = match ty::get(fn_ty).sty {
         ty::ty_closure(ref f) => (f.sig.clone(), f.abi, true),
         ty::ty_bare_fn(ref f) => (f.sig.clone(), f.abi, false),
-        ty::ty_unboxed_closure(closure_did, _) => {
+        ty::ty_unboxed_closure(closure_did, _, ref substs) => {
             let unboxed_closures = ccx.tcx().unboxed_closures.borrow();
             let ref function_type = (*unboxed_closures)[closure_did]
                                                     .closure_type;
 
-            (function_type.sig.clone(), RustCall, true)
+            (function_type.sig.subst(ccx.tcx(), substs), RustCall, true)
         }
         _ => ccx.sess().bug("expected closure or function.")
     };
@@ -2371,7 +2369,7 @@ pub fn get_fn_llvm_attributes(ccx: &CrateContext, fn_ty: ty::t)
     // These have an odd calling convention, so we need to manually
     // unpack the input ty's
     let input_tys = match ty::get(fn_ty).sty {
-        ty::ty_unboxed_closure(_, _) => {
+        ty::ty_unboxed_closure(_, _, _) => {
             assert!(abi == RustCall);
 
             match ty::get(fn_sig.inputs[0]).sty {

src/librustc/middle/trans/callee.rs

@@ -491,7 +491,7 @@ pub fn trans_fn_ref_with_substs(
     };
 
     // If this is an unboxed closure, redirect to it.
-    match closure::get_or_create_declaration_if_unboxed_closure(ccx, def_id) {
+    match closure::get_or_create_declaration_if_unboxed_closure(bcx, def_id) {
         None => {}
         Some(llfn) => return llfn,
     }

src/librustc/middle/trans/closure.rs

@@ -23,6 +23,7 @@ use middle::trans::common::*;
 use middle::trans::datum::{Datum, DatumBlock, Expr, Lvalue, rvalue_scratch_datum};
 use middle::trans::debuginfo;
 use middle::trans::expr;
+use middle::trans::monomorphize::MonoId;
 use middle::trans::type_of::*;
 use middle::trans::type_::Type;
 use middle::ty;
@@ -312,7 +313,8 @@ fn load_unboxed_closure_environment<'blk, 'tcx>(
     }
 
     // Special case for small by-value selfs.
-    let self_type = self_type_for_unboxed_closure(bcx.ccx(), closure_id);
+    let self_type = self_type_for_unboxed_closure(bcx.ccx(), closure_id,
+                                                  node_id_type(bcx, closure_id.node));
     let kind = kind_for_unboxed_closure(bcx.ccx(), closure_id);
     let llenv = if kind == ty::FnOnceUnboxedClosureKind &&
             !arg_is_indirect(bcx.ccx(), self_type) {
@@ -418,15 +420,26 @@ pub fn trans_expr_fn<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
 
 /// Returns the LLVM function declaration for an unboxed closure, creating it
 /// if necessary. If the ID does not correspond to a closure ID, returns None.
-pub fn get_or_create_declaration_if_unboxed_closure(ccx: &CrateContext,
-                                                    closure_id: ast::DefId)
-                                                    -> Option<ValueRef> {
+pub fn get_or_create_declaration_if_unboxed_closure<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
+                                                                closure_id: ast::DefId)
+                                                                -> Option<ValueRef> {
+    let ccx = bcx.ccx();
     if !ccx.tcx().unboxed_closures.borrow().contains_key(&closure_id) {
         // Not an unboxed closure.
         return None
     }
 
-    match ccx.unboxed_closure_vals().borrow().find(&closure_id) {
+    let function_type = node_id_type(bcx, closure_id.node);
+    let params = match ty::get(function_type).sty {
+        ty::ty_unboxed_closure(_, _, ref substs) => substs.types.clone(),
+        _ => unreachable!()
+    };
+    let mono_id = MonoId {
+        def: closure_id,
+        params: params
+    };
+
+    match ccx.unboxed_closure_vals().borrow().find(&mono_id) {
         Some(llfn) => {
             debug!("get_or_create_declaration_if_unboxed_closure(): found \
                     closure");
@@ -435,9 +448,7 @@ pub fn get_or_create_declaration_if_unboxed_closure(ccx: &CrateContext,
         None => {}
     }
 
-    let function_type = ty::mk_unboxed_closure(ccx.tcx(),
-                                               closure_id,
-                                               ty::ReStatic);
+    let function_type = node_id_type(bcx, closure_id.node);
     let symbol = ccx.tcx().map.with_path(closure_id.node, |path| {
         mangle_internal_name_by_path_and_seq(path, "unboxed_closure")
     });
@@ -449,9 +460,9 @@ pub fn get_or_create_declaration_if_unboxed_closure(ccx: &CrateContext,
 
     debug!("get_or_create_declaration_if_unboxed_closure(): inserting new \
             closure {} (type {})",
-           closure_id,
+           mono_id,
            ccx.tn().type_to_string(val_ty(llfn)));
-    ccx.unboxed_closure_vals().borrow_mut().insert(closure_id, llfn);
+    ccx.unboxed_closure_vals().borrow_mut().insert(mono_id, llfn);
 
     Some(llfn)
 }
@@ -469,7 +480,7 @@ pub fn trans_unboxed_closure<'blk, 'tcx>(
 
     let closure_id = ast_util::local_def(id);
     let llfn = get_or_create_declaration_if_unboxed_closure(
-        bcx.ccx(),
+        bcx,
         closure_id).unwrap();
 
     let unboxed_closures = bcx.tcx().unboxed_closures.borrow();

src/librustc/middle/trans/context.rs

@@ -138,7 +138,7 @@ pub struct LocalCrateContext {
     builder: BuilderRef_res,
 
     /// Holds the LLVM values for closure IDs.
-    unboxed_closure_vals: RefCell<DefIdMap<ValueRef>>,
+    unboxed_closure_vals: RefCell<HashMap<MonoId, ValueRef>>,
 
     dbg_cx: Option<debuginfo::CrateDebugContext>,
 
@@ -419,7 +419,7 @@ impl LocalCrateContext {
                 int_type: Type::from_ref(ptr::null_mut()),
                 opaque_vec_type: Type::from_ref(ptr::null_mut()),
                 builder: BuilderRef_res(llvm::LLVMCreateBuilderInContext(llcx)),
-                unboxed_closure_vals: RefCell::new(DefIdMap::new()),
+                unboxed_closure_vals: RefCell::new(HashMap::new()),
                 dbg_cx: dbg_cx,
                 eh_personality: RefCell::new(None),
                 intrinsics: RefCell::new(HashMap::new()),
@@ -689,7 +689,7 @@ impl<'b, 'tcx> CrateContext<'b, 'tcx> {
         self.local.opaque_vec_type
     }
 
-    pub fn unboxed_closure_vals<'a>(&'a self) -> &'a RefCell<DefIdMap<ValueRef>> {
+    pub fn unboxed_closure_vals<'a>(&'a self) -> &'a RefCell<HashMap<MonoId,ValueRef>> {
         &self.local.unboxed_closure_vals
     }
 

src/librustc/middle/trans/debuginfo.rs

@@ -190,7 +190,7 @@ use llvm;
 use llvm::{ModuleRef, ContextRef, ValueRef};
 use llvm::debuginfo::*;
 use metadata::csearch;
-use middle::subst;
+use middle::subst::{mod, Subst};
 use middle::trans::adt;
 use middle::trans::common::*;
 use middle::trans::machine;
@@ -460,9 +460,9 @@ impl TypeMap {
                                                         closure_ty.clone(),
                                                         &mut unique_type_id);
             },
-            ty::ty_unboxed_closure(ref def_id, _) => {
+            ty::ty_unboxed_closure(ref def_id, _, ref substs) => {
                 let closure_ty = cx.tcx().unboxed_closures.borrow()
-                                   .find(def_id).unwrap().closure_type.clone();
+                                   .find(def_id).unwrap().closure_type.subst(cx.tcx(), substs);
                 self.get_unique_type_id_of_closure_type(cx,
                                                         closure_ty,
                                                         &mut unique_type_id);
@@ -2911,9 +2911,9 @@ fn type_metadata(cx: &CrateContext,
         ty::ty_closure(ref closurety) => {
             subroutine_type_metadata(cx, unique_type_id, &closurety.sig, usage_site_span)
         }
-        ty::ty_unboxed_closure(ref def_id, _) => {
+        ty::ty_unboxed_closure(ref def_id, _, ref substs) => {
             let sig = cx.tcx().unboxed_closures.borrow()
-                        .find(def_id).unwrap().closure_type.sig.clone();
+                        .find(def_id).unwrap().closure_type.sig.subst(cx.tcx(), substs);
             subroutine_type_metadata(cx, unique_type_id, &sig, usage_site_span)
         }
         ty::ty_struct(def_id, ref substs) => {