auto merge of #12403 : eddyb/rust/generic-dtors-with-bounds, r=nikomatsakis

Fix generic Drop impls with trait bounds.
Fixes #4252.

Author: bors

src/librustc/middle/astencode.rs

@@ -20,7 +20,7 @@ use metadata::tydecode;
 use metadata::tydecode::{DefIdSource, NominalType, TypeWithId, TypeParameter,
                          RegionParameter};
 use metadata::tyencode;
-use middle::typeck::{method_origin, method_map_entry};
+use middle::typeck::method_origin;
 use middle::{ty, typeck, moves};
 use middle;
 use util::ppaux::ty_to_str;
@@ -573,35 +573,7 @@ impl tr for moves::CaptureVar {
 }
 
 // ______________________________________________________________________
-// Encoding and decoding of method_map_entry
-
-trait read_method_map_entry_helper {
-    fn read_method_map_entry(&mut self, xcx: @ExtendedDecodeContext)
-                             -> method_map_entry;
-}
-
-fn encode_method_map_entry(ebml_w: &mut writer::Encoder, mme: method_map_entry) {
-    ebml_w.emit_struct("method_map_entry", 3, |ebml_w| {
-        ebml_w.emit_struct_field("origin", 1u, |ebml_w| {
-            mme.origin.encode(ebml_w);
-        });
-    })
-}
-
-impl<'a> read_method_map_entry_helper for reader::Decoder<'a> {
-    fn read_method_map_entry(&mut self, xcx: @ExtendedDecodeContext)
-                             -> method_map_entry {
-        self.read_struct("method_map_entry", 3, |this| {
-            method_map_entry {
-                origin: this.read_struct_field("origin", 1, |this| {
-                    let method_origin: method_origin =
-                        Decodable::decode(this);
-                    method_origin.tr(xcx)
-                })
-            }
-        })
-    }
-}
+// Encoding and decoding of method_origin
 
 impl tr for method_origin {
     fn tr(&self, xcx: @ExtendedDecodeContext) -> method_origin {
@@ -1023,11 +995,11 @@ fn encode_side_tables_for_id(ecx: &e::EncodeContext,
     {
         let method_map = maps.method_map.borrow();
         let r = method_map.get().find(&id);
-        for &mme in r.iter() {
+        for &origin in r.iter() {
             ebml_w.tag(c::tag_table_method_map, |ebml_w| {
                 ebml_w.id(id);
                 ebml_w.tag(c::tag_table_val, |ebml_w| {
-                    encode_method_map_entry(ebml_w, *mme)
+                    origin.encode(ebml_w);
                 })
             })
         }
@@ -1364,9 +1336,9 @@ fn decode_side_tables(xcx: @ExtendedDecodeContext,
                         ty_param_defs.get().insert(id, bounds);
                     }
                     c::tag_table_method_map => {
-                        let entry = val_dsr.read_method_map_entry(xcx);
+                        let origin: method_origin = Decodable::decode(val_dsr);
                         let mut method_map = dcx.maps.method_map.borrow_mut();
-                        method_map.get().insert(id, entry);
+                        method_map.get().insert(id, origin.tr(xcx));
                     }
                     c::tag_table_vtable_map => {
                         let vtable_res =

src/librustc/middle/dead.rs

@@ -94,7 +94,7 @@ impl MarkSymbolVisitor {
                                 span: codemap::Span) {
         let method_map = self.method_map.borrow();
         match method_map.get().find(id) {
-            Some(&typeck::method_map_entry { origin, .. }) => {
+            Some(&origin) => {
                 match origin {
                     typeck::method_static(def_id) => {
                         match ty::provided_source(self.tcx, def_id) {

src/librustc/middle/kind.rs

@@ -285,8 +285,15 @@ pub fn check_expr(cx: &mut Context, e: &Expr) {
 
                 // Even though the callee_id may have been the id with
                 // node_type_substs, e.id is correct here.
-                ty::method_call_type_param_defs(cx.tcx, cx.method_map, e.id).expect(
-                    "non path/method call expr has type substs??")
+                match cx.method_map.borrow().get().find(&e.id) {
+                    Some(origin) => {
+                        ty::method_call_type_param_defs(cx.tcx, *origin)
+                    }
+                    None => {
+                        cx.tcx.sess.span_bug(e.span,
+                            "non path/method call expr has type substs??");
+                    }
+                }
               }
             };
             let type_param_defs = type_param_defs.borrow();

src/librustc/middle/lint.rs

@@ -1400,7 +1400,7 @@ fn check_stability(cx: &Context, e: &ast::Expr) {
         ast::ExprMethodCall(..) => {
             let method_map = cx.method_map.borrow();
             match method_map.get().find(&e.id) {
-                Some(&typeck::method_map_entry { origin, .. }) => {
+                Some(&origin) => {
                     match origin {
                         typeck::method_static(def_id) => {
                             // If this implements a trait method, get def_id

src/librustc/middle/privacy.rs

@@ -790,17 +790,17 @@ impl<'a> Visitor<()> for PrivacyVisitor<'a> {
                 let t = ty::type_autoderef(ty::expr_ty(self.tcx, args[0]));
                 match ty::get(t).sty {
                     ty::ty_enum(_, _) | ty::ty_struct(_, _) => {
-                        let method_map = self.method_map.borrow();
-                        let entry = match method_map.get().find(&expr.id) {
+                        match self.method_map.borrow().get().find(&expr.id) {
                             None => {
                                 self.tcx.sess.span_bug(expr.span,
                                                        "method call not in \
                                                         method map");
                             }
-                            Some(entry) => entry
-                        };
-                        debug!("(privacy checking) checking impl method");
-                        self.check_method(expr.span, &entry.origin, ident);
+                            Some(origin) => {
+                                debug!("(privacy checking) checking impl method");
+                                self.check_method(expr.span, origin, ident);
+                            }
+                        }
                     }
                     _ => {}
                 }

src/librustc/middle/reachable.rs

@@ -149,10 +149,7 @@ impl Visitor<()> for MarkSymbolVisitor {
             ast::ExprMethodCall(..) => {
                 let method_map = self.method_map.borrow();
                 match method_map.get().find(&expr.id) {
-                    Some(&typeck::method_map_entry {
-                        origin: typeck::method_static(def_id),
-                        ..
-                    }) => {
+                    Some(&typeck::method_static(def_id)) => {
                         if is_local(def_id) {
                             if ReachableContext::
                                 def_id_represents_local_inlined_item(
@@ -174,8 +171,7 @@ impl Visitor<()> for MarkSymbolVisitor {
                     Some(_) => {}
                     None => {
                         self.tcx.sess.span_bug(expr.span,
-                        "method call expression \
-                                                   not in method map?!")
+                            "method call expression not in method map?!")
                     }
                 }
             }

src/librustc/middle/trans/base.rs

@@ -65,6 +65,7 @@ use middle::trans::type_of;
 use middle::trans::type_of::*;
 use middle::trans::value::Value;
 use middle::ty;
+use middle::typeck;
 use util::common::indenter;
 use util::ppaux::{Repr, ty_to_str};
 use util::sha2::Sha256;
@@ -535,22 +536,14 @@ pub fn get_res_dtor(ccx: @CrateContext,
     };
     if !substs.is_empty() {
         assert_eq!(did.krate, ast::LOCAL_CRATE);
-        let tsubsts = ty::substs {regions: ty::ErasedRegions,
-                                  self_ty: None,
-                                  tps: /*bad*/ substs.to_owned() };
-
-        // FIXME: #4252: Generic destructors with type bounds are broken.
-        //
-        // Since the vtables aren't passed to `monomorphic_fn` here, generic destructors with type
-        // bounds are broken. Sadly, the `typeck` pass isn't outputting the necessary metadata
-        // because it does so based on method calls present in the AST. Destructor calls are not yet
-        // known about at that stage of compilation, since `trans` handles cleanups.
-        let (val, _) = monomorphize::monomorphic_fn(ccx,
-                                                    did,
-                                                    &tsubsts,
-                                                    None,
-                                                    None,
-                                                    None);
+        let tsubsts = ty::substs {
+            regions: ty::ErasedRegions,
+            self_ty: None,
+            tps: substs.to_owned()
+        };
+
+        let vtables = typeck::check::vtable::trans_resolve_method(ccx.tcx, did.node, &tsubsts);
+        let (val, _) = monomorphize::monomorphic_fn(ccx, did, &tsubsts, vtables, None, None);
 
         val
     } else if did.krate == ast::LOCAL_CRATE {

src/librustc/middle/trans/meth.rs

@@ -95,16 +95,15 @@ pub fn trans_method_callee<'a>(
                            bcx: &'a Block<'a>,
                            callee_id: ast::NodeId,
                            this: &ast::Expr,
-                           mentry: typeck::method_map_entry,
+                           origin: typeck::method_origin,
                            arg_cleanup_scope: cleanup::ScopeId)
                            -> Callee<'a> {
     let _icx = push_ctxt("meth::trans_method_callee");
 
-    debug!("trans_method_callee(callee_id={:?}, mentry={})",
-           callee_id,
-           mentry.repr(bcx.tcx()));
+    debug!("trans_method_callee(callee_id={:?}, origin={})",
+           callee_id, origin.repr(bcx.tcx()));
 
-    match mentry.origin {
+    match origin {
         typeck::method_static(did) => {
             Callee {
                 bcx: bcx,

src/librustc/middle/ty.rs

@@ -3242,25 +3242,21 @@ pub fn expr_has_ty_params(cx: ctxt, expr: &ast::Expr) -> bool {
     return node_id_has_type_params(cx, expr.id);
 }
 
-pub fn method_call_type_param_defs(tcx: ctxt,
-                                   method_map: typeck::method_map,
-                                   id: ast::NodeId)
-                                   -> Option<Rc<~[TypeParameterDef]>> {
-    let method_map = method_map.borrow();
-    method_map.get().find(&id).map(|method| {
-        match method.origin {
-          typeck::method_static(did) => {
+pub fn method_call_type_param_defs(tcx: ctxt, origin: typeck::method_origin)
+                                   -> Rc<~[TypeParameterDef]> {
+    match origin {
+        typeck::method_static(did) => {
             // n.b.: When we encode impl methods, the bounds
             // that we encode include both the impl bounds
             // and then the method bounds themselves...
             ty::lookup_item_type(tcx, did).generics.type_param_defs
-          }
-          typeck::method_param(typeck::method_param {
-              trait_id: trt_id,
-              method_num: n_mth, ..}) |
-          typeck::method_object(typeck::method_object {
-              trait_id: trt_id,
-              method_num: n_mth, ..}) => {
+        }
+        typeck::method_param(typeck::method_param {
+            trait_id: trt_id,
+            method_num: n_mth, ..}) |
+        typeck::method_object(typeck::method_object {
+            trait_id: trt_id,
+            method_num: n_mth, ..}) => {
             // ...trait methods bounds, in contrast, include only the
             // method bounds, so we must preprend the tps from the
             // trait itself.  This ought to be harmonized.
@@ -3271,9 +3267,8 @@ pub fn method_call_type_param_defs(tcx: ctxt,
                 ty::trait_method(tcx,
                                  trt_id,
                                  n_mth).generics.type_param_defs()))
-          }
         }
-    })
+    }
 }
 
 pub fn resolve_expr(tcx: ctxt, expr: &ast::Expr) -> ast::Def {

src/librustc/middle/typeck/check/demand.rs

@@ -20,17 +20,17 @@ use syntax::codemap::Span;
 
 // Requires that the two types unify, and prints an error message if they
 // don't.
-pub fn suptype(fcx: @FnCtxt, sp: Span, expected: ty::t, actual: ty::t) {
+pub fn suptype(fcx: &FnCtxt, sp: Span, expected: ty::t, actual: ty::t) {
     suptype_with_fn(fcx, sp, false, expected, actual,
         |sp, e, a, s| { fcx.report_mismatched_types(sp, e, a, s) })
 }
 
-pub fn subtype(fcx: @FnCtxt, sp: Span, expected: ty::t, actual: ty::t) {
+pub fn subtype(fcx: &FnCtxt, sp: Span, expected: ty::t, actual: ty::t) {
     suptype_with_fn(fcx, sp, true, actual, expected,
         |sp, a, e, s| { fcx.report_mismatched_types(sp, e, a, s) })
 }
 
-pub fn suptype_with_fn(fcx: @FnCtxt,
+pub fn suptype_with_fn(fcx: &FnCtxt,
                        sp: Span,
                        b_is_expected: bool,
                        ty_a: ty::t,

src/librustc/middle/typeck/check/method.rs

@@ -90,7 +90,7 @@ use middle::typeck::check::{structurally_resolved_type};
 use middle::typeck::check::vtable;
 use middle::typeck::check;
 use middle::typeck::infer;
-use middle::typeck::{method_map_entry, method_origin, method_param};
+use middle::typeck::{method_origin, method_param};
 use middle::typeck::{method_static, method_object};
 use middle::typeck::{param_numbered, param_self, param_index};
 use middle::typeck::check::regionmanip::replace_bound_regions_in_fn_sig;
@@ -133,7 +133,7 @@ pub fn lookup(
         deref_args: check::DerefArgs,       // Whether we autopointer first.
         check_traits: CheckTraitsFlag,      // Whether we check traits only.
         autoderef_receiver: AutoderefReceiverFlag)
-     -> Option<method_map_entry> {
+     -> Option<method_origin> {
     let impl_dups = @RefCell::new(HashSet::new());
     let lcx = LookupContext {
         fcx: fcx,
@@ -211,7 +211,7 @@ enum RcvrMatchCondition {
 }
 
 impl<'a> LookupContext<'a> {
-    fn search(&self, self_ty: ty::t) -> Option<method_map_entry> {
+    fn search(&self, self_ty: ty::t) -> Option<method_origin> {
         let mut self_ty = self_ty;
         let mut autoderefs = 0;
         loop {
@@ -592,7 +592,7 @@ impl<'a> LookupContext<'a> {
     fn search_for_autoderefd_method(&self,
                                         self_ty: ty::t,
                                         autoderefs: uint)
-                                        -> Option<method_map_entry> {
+                                        -> Option<method_origin> {
         let (self_ty, autoadjust) =
             self.consider_reborrow(self_ty, autoderefs);
         match self.search_for_method(self_ty) {
@@ -686,9 +686,9 @@ impl<'a> LookupContext<'a> {
     }
 
     fn search_for_autosliced_method(&self,
-                                        self_ty: ty::t,
-                                        autoderefs: uint)
-                                        -> Option<method_map_entry> {
+                                    self_ty: ty::t,
+                                    autoderefs: uint)
+                                    -> Option<method_origin> {
         /*!
          *
          * Searches for a candidate by converting things like
@@ -763,7 +763,7 @@ impl<'a> LookupContext<'a> {
     }
 
     fn search_for_autoptrd_method(&self, self_ty: ty::t, autoderefs: uint)
-                                      -> Option<method_map_entry> {
+                                  -> Option<method_origin> {
         /*!
          *
          * Converts any type `T` to `&M T` where `M` is an
@@ -799,7 +799,7 @@ impl<'a> LookupContext<'a> {
             autoderefs: uint,
             mutbls: &[ast::Mutability],
             mk_autoref_ty: |ast::Mutability, ty::Region| -> ty::t)
-            -> Option<method_map_entry> {
+            -> Option<method_origin> {
         // This is hokey. We should have mutability inference as a
         // variable.  But for now, try &const, then &, then &mut:
         let region =
@@ -823,7 +823,7 @@ impl<'a> LookupContext<'a> {
     }
 
     fn search_for_method(&self, rcvr_ty: ty::t)
-                             -> Option<method_map_entry> {
+                         -> Option<method_origin> {
         debug!("search_for_method(rcvr_ty={})", self.ty_to_str(rcvr_ty));
         let _indenter = indenter();
 
@@ -855,7 +855,7 @@ impl<'a> LookupContext<'a> {
     fn consider_candidates(&self,
                            rcvr_ty: ty::t,
                            candidates: &mut ~[Candidate])
-                           -> Option<method_map_entry> {
+                           -> Option<method_origin> {
         // FIXME(pcwalton): Do we need to clone here?
         let relevant_candidates: ~[Candidate] =
             candidates.iter().map(|c| (*c).clone()).
@@ -926,7 +926,7 @@ impl<'a> LookupContext<'a> {
     }
 
     fn confirm_candidate(&self, rcvr_ty: ty::t, candidate: &Candidate)
-                             -> method_map_entry {
+                         -> method_origin {
         // This method performs two sets of substitutions, one after the other:
         // 1. Substitute values for any type/lifetime parameters from the impl and
         //    method declaration into the method type. This is the function type
@@ -1037,9 +1037,7 @@ impl<'a> LookupContext<'a> {
 
         self.fcx.write_ty(self.callee_id, fty);
         self.fcx.write_substs(self.callee_id, all_substs);
-        method_map_entry {
-            origin: candidate.origin
-        }
+        candidate.origin
     }
 
     fn construct_transformed_self_ty_for_object(