Consistently normalize fn types after erasing lifetimes.

Fixes #23406.
Fixes #23958.
Fixes #29832.

src/librustc_trans/trans/attributes.rs

@@ -142,6 +142,7 @@ pub fn from_fn_type<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, fn_type: ty::Ty<'tcx
     };
 
     let fn_sig = ccx.tcx().erase_late_bound_regions(fn_sig);
+    let fn_sig = infer::normalize_associated_type(ccx.tcx(), &fn_sig);
 
     let mut attrs = llvm::AttrBuilder::new();
     let ret_ty = fn_sig.output;

src/librustc_trans/trans/base.rs

@@ -38,6 +38,7 @@ use metadata::{csearch, encoder, loader};
 use middle::astencode;
 use middle::cfg;
 use middle::def_id::DefId;
+use middle::infer;
 use middle::lang_items::{LangItem, ExchangeMallocFnLangItem, StartFnLangItem};
 use middle::weak_lang_items;
 use middle::pat_util::simple_name;
@@ -1905,7 +1906,11 @@ pub fn trans_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
     debug!("trans_fn(param_substs={:?})", param_substs);
     let _icx = push_ctxt("trans_fn");
     let fn_ty = ccx.tcx().node_id_to_type(id);
-    let output_type = ccx.tcx().erase_late_bound_regions(&fn_ty.fn_ret());
+    let fn_ty = monomorphize::apply_param_substs(ccx.tcx(), param_substs, &fn_ty);
+    let sig = fn_ty.fn_sig();
+    let sig = ccx.tcx().erase_late_bound_regions(&sig);
+    let sig = infer::normalize_associated_type(ccx.tcx(), &sig);
+    let output_type = sig.output;
     let abi = fn_ty.fn_abi();
     trans_closure(ccx, decl, body, llfndecl, param_substs, id, attrs, output_type, abi,
                   closure::ClosureEnv::NotClosure);
@@ -1936,15 +1941,9 @@ pub fn trans_named_tuple_constructor<'blk, 'tcx>(mut bcx: Block<'blk, 'tcx>,
 
     let ccx = bcx.fcx.ccx;
 
-    let result_ty = match ctor_ty.sty {
-        ty::TyBareFn(_, ref bft) => {
-            bcx.tcx().erase_late_bound_regions(&bft.sig.output()).unwrap()
-        }
-        _ => ccx.sess().bug(
-            &format!("trans_enum_variant_constructor: \
-                     unexpected ctor return type {}",
-                     ctor_ty))
-    };
+    let sig = ccx.tcx().erase_late_bound_regions(&ctor_ty.fn_sig());
+    let sig = infer::normalize_associated_type(ccx.tcx(), &sig);
+    let result_ty = sig.output.unwrap();
 
     // Get location to store the result. If the user does not care about
     // the result, just make a stack slot
@@ -2026,15 +2025,10 @@ fn trans_enum_variant_or_tuple_like_struct<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx
     let ctor_ty = ccx.tcx().node_id_to_type(ctor_id);
     let ctor_ty = monomorphize::apply_param_substs(ccx.tcx(), param_substs, &ctor_ty);
 
-    let result_ty = match ctor_ty.sty {
-        ty::TyBareFn(_, ref bft) => {
-            ccx.tcx().erase_late_bound_regions(&bft.sig.output())
-        }
-        _ => ccx.sess().bug(
-            &format!("trans_enum_variant_or_tuple_like_struct: \
-                     unexpected ctor return type {}",
-                    ctor_ty))
-    };
+    let sig = ccx.tcx().erase_late_bound_regions(&ctor_ty.fn_sig());
+    let sig = infer::normalize_associated_type(ccx.tcx(), &sig);
+    let arg_tys = sig.inputs;
+    let result_ty = sig.output;
 
     let (arena, fcx): (TypedArena<_>, FunctionContext);
     arena = TypedArena::new();
@@ -2044,8 +2038,6 @@ fn trans_enum_variant_or_tuple_like_struct<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx
 
     assert!(!fcx.needs_ret_allocas);
 
-    let arg_tys = ccx.tcx().erase_late_bound_regions(&ctor_ty.fn_args());
-
     if !type_is_zero_size(fcx.ccx, result_ty.unwrap()) {
         let dest = fcx.get_ret_slot(bcx, result_ty, "eret_slot");
         let repr = adt::represent_type(ccx, result_ty.unwrap());

src/librustc_trans/trans/callee.rs

@@ -25,7 +25,7 @@ use llvm::{self, ValueRef, get_params};
 use metadata::cstore::LOCAL_CRATE;
 use middle::def;
 use middle::def_id::DefId;
-use middle::infer::normalize_associated_type;
+use middle::infer;
 use middle::subst;
 use middle::subst::{Substs};
 use rustc::front::map as hir_map;
@@ -304,6 +304,7 @@ pub fn trans_fn_pointer_shim<'a, 'tcx>(
             }
         };
     let sig = tcx.erase_late_bound_regions(sig);
+    let sig = infer::normalize_associated_type(ccx.tcx(), &sig);
     let tuple_input_ty = tcx.mk_tup(sig.inputs.to_vec());
     let tuple_fn_ty = tcx.mk_fn(opt_def_id,
         tcx.mk_bare_fn(ty::BareFnTy {
@@ -466,7 +467,7 @@ pub fn trans_fn_ref_with_substs<'a, 'tcx>(
 
     // Type scheme of the function item (may have type params)
     let fn_type_scheme = tcx.lookup_item_type(def_id);
-    let fn_type = normalize_associated_type(tcx, &fn_type_scheme.ty);
+    let fn_type = infer::normalize_associated_type(tcx, &fn_type_scheme.ty);
 
     // Find the actual function pointer.
     let mut val = {
@@ -605,8 +606,9 @@ pub fn trans_call_inner<'a, 'blk, 'tcx, F>(bcx: Block<'blk, 'tcx>,
 
     let (abi, ret_ty) = match callee.ty.sty {
         ty::TyBareFn(_, ref f) => {
-            let output = bcx.tcx().erase_late_bound_regions(&f.sig.output());
-            (f.abi, output)
+            let sig = bcx.tcx().erase_late_bound_regions(&f.sig);
+            let sig = infer::normalize_associated_type(bcx.tcx(), &sig);
+            (f.abi, sig.output)
         }
         _ => panic!("expected bare rust fn or closure in trans_call_inner")
     };
@@ -826,7 +828,9 @@ fn trans_args_under_call_abi<'blk, 'tcx>(
                              ignore_self: bool)
                              -> Block<'blk, 'tcx>
 {
-    let args = bcx.tcx().erase_late_bound_regions(&fn_ty.fn_args());
+    let sig = bcx.tcx().erase_late_bound_regions(&fn_ty.fn_sig());
+    let sig = infer::normalize_associated_type(bcx.tcx(), &sig);
+    let args = sig.inputs;
 
     // Translate the `self` argument first.
     if !ignore_self {
@@ -887,7 +891,10 @@ fn trans_overloaded_call_args<'blk, 'tcx>(
                               ignore_self: bool)
                               -> Block<'blk, 'tcx> {
     // Translate the `self` argument first.
-    let arg_tys = bcx.tcx().erase_late_bound_regions( &fn_ty.fn_args());
+    let sig = bcx.tcx().erase_late_bound_regions(&fn_ty.fn_sig());
+    let sig = infer::normalize_associated_type(bcx.tcx(), &sig);
+    let arg_tys = sig.inputs;
+
     if !ignore_self {
         let arg_datum = unpack_datum!(bcx, expr::trans(bcx, arg_exprs[0]));
         bcx = trans_arg_datum(bcx,
@@ -933,8 +940,10 @@ pub fn trans_args<'a, 'blk, 'tcx>(cx: Block<'blk, 'tcx>,
     debug!("trans_args(abi={})", abi);
 
     let _icx = push_ctxt("trans_args");
-    let arg_tys = cx.tcx().erase_late_bound_regions(&fn_ty.fn_args());
-    let variadic = fn_ty.fn_sig().0.variadic;
+    let sig = cx.tcx().erase_late_bound_regions(&fn_ty.fn_sig());
+    let sig = infer::normalize_associated_type(cx.tcx(), &sig);
+    let arg_tys = sig.inputs;
+    let variadic = sig.variadic;
 
     let mut bcx = cx;
 

src/librustc_trans/trans/closure.rs

@@ -210,6 +210,7 @@ pub fn trans_closure_expr<'a, 'tcx>(dest: Dest<'a, 'tcx>,
         tcx.with_freevars(id, |fv| fv.iter().cloned().collect());
 
     let sig = tcx.erase_late_bound_regions(&function_type.sig);
+    let sig = infer::normalize_associated_type(ccx.tcx(), &sig);
 
     trans_closure(ccx,
                   decl,
@@ -371,6 +372,8 @@ fn trans_fn_once_adapter_shim<'a, 'tcx>(
     let lloncefn = declare::define_internal_rust_fn(ccx, &function_name,
                                                     llonce_fn_ty);
     let sig = tcx.erase_late_bound_regions(&llonce_bare_fn_ty.sig);
+    let sig = infer::normalize_associated_type(ccx.tcx(), &sig);
+
     let (block_arena, fcx): (TypedArena<_>, FunctionContext);
     block_arena = TypedArena::new();
     fcx = new_fn_ctxt(ccx,

src/librustc_trans/trans/debuginfo/metadata.rs

@@ -24,6 +24,7 @@ use llvm::{self, ValueRef};
 use llvm::debuginfo::{DIType, DIFile, DIScope, DIDescriptor, DICompositeType};
 
 use middle::def_id::DefId;
+use middle::infer;
 use middle::pat_util;
 use middle::subst::{self, Substs};
 use rustc::front::map as hir_map;
@@ -262,6 +263,7 @@ impl<'tcx> TypeMap<'tcx> {
                 unique_type_id.push_str(" fn(");
 
                 let sig = cx.tcx().erase_late_bound_regions(sig);
+                let sig = infer::normalize_associated_type(cx.tcx(), &sig);
 
                 for &parameter_type in &sig.inputs {
                     let parameter_type_id =

src/librustc_trans/trans/debuginfo/mod.rs

@@ -35,6 +35,7 @@ use rustc_front::hir;
 use trans::common::{NodeIdAndSpan, CrateContext, FunctionContext, Block};
 use trans;
 use trans::{monomorphize, type_of};
+use middle::infer;
 use middle::ty::{self, Ty};
 use session::config::{self, FullDebugInfo, LimitedDebugInfo, NoDebugInfo};
 use util::nodemap::{NodeMap, FnvHashMap, FnvHashSet};
@@ -418,19 +419,23 @@ pub fn create_function_debug_context<'a, 'tcx>(cx: &CrateContext<'a, 'tcx>,
         // Return type -- llvm::DIBuilder wants this at index 0
         assert_type_for_node_id(cx, fn_ast_id, error_reporting_span);
         let fn_type = cx.tcx().node_id_to_type(fn_ast_id);
+        let fn_type = monomorphize::apply_param_substs(cx.tcx(), param_substs, &fn_type);
 
         let (sig, abi) = match fn_type.sty {
             ty::TyBareFn(_, ref barefnty) => {
-                (cx.tcx().erase_late_bound_regions(&barefnty.sig), barefnty.abi)
+                let sig = cx.tcx().erase_late_bound_regions(&barefnty.sig);
+                let sig = infer::normalize_associated_type(cx.tcx(), &sig);
+                (sig, barefnty.abi)
             }
             ty::TyClosure(def_id, ref substs) => {
                 let closure_type = cx.tcx().closure_type(def_id, substs);
-                (cx.tcx().erase_late_bound_regions(&closure_type.sig), closure_type.abi)
+                let sig = cx.tcx().erase_late_bound_regions(&closure_type.sig);
+                let sig = infer::normalize_associated_type(cx.tcx(), &sig);
+                (sig, closure_type.abi)
             }
 
             _ => cx.sess().bug("get_function_metdata: Expected a function type!")
         };
-        let sig = monomorphize::apply_param_substs(cx.tcx(), param_substs, &sig);
 
         let mut signature = Vec::with_capacity(sig.inputs.len() + 1);
 

src/librustc_trans/trans/debuginfo/type_names.rs

@@ -14,6 +14,7 @@ use super::namespace::crate_root_namespace;
 
 use trans::common::CrateContext;
 use middle::def_id::DefId;
+use middle::infer;
 use middle::subst::{self, Substs};
 use middle::ty::{self, Ty};
 
@@ -124,6 +125,7 @@ pub fn push_debuginfo_type_name<'a, 'tcx>(cx: &CrateContext<'a, 'tcx>,
             output.push_str("fn(");
 
             let sig = cx.tcx().erase_late_bound_regions(sig);
+            let sig = infer::normalize_associated_type(cx.tcx(), &sig);
             if !sig.inputs.is_empty() {
                 for &parameter_type in &sig.inputs {
                     push_debuginfo_type_name(cx, parameter_type, true, output);

src/librustc_trans/trans/declare.rs

@@ -103,9 +103,6 @@ pub fn declare_rust_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, name: &str,
                                  fn_type: ty::Ty<'tcx>) -> ValueRef {
     debug!("declare_rust_fn(name={:?}, fn_type={:?})", name,
            fn_type);
-    let fn_type = infer::normalize_associated_type(ccx.tcx(), &fn_type);
-    debug!("declare_rust_fn (after normalised associated types) fn_type={:?}",
-           fn_type);
 
     let function_type; // placeholder so that the memory ownership works out ok
     let (sig, abi, env) = match fn_type.sty {
@@ -124,14 +121,15 @@ pub fn declare_rust_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, name: &str,
         _ => ccx.sess().bug("expected closure or fn")
     };
 
-    let sig = ty::Binder(ccx.tcx().erase_late_bound_regions(sig));
+    let sig = ccx.tcx().erase_late_bound_regions(sig);
+    let sig = infer::normalize_associated_type(ccx.tcx(), &sig);
     debug!("declare_rust_fn (after region erasure) sig={:?}", sig);
     let llfty = type_of::type_of_rust_fn(ccx, env, &sig, abi);
     debug!("declare_rust_fn llfty={}", ccx.tn().type_to_string(llfty));
 
     // it is ok to directly access sig.0.output because we erased all
     // late-bound-regions above
-    let llfn = declare_fn(ccx, name, llvm::CCallConv, llfty, sig.0.output);
+    let llfn = declare_fn(ccx, name, llvm::CCallConv, llfty, sig.output);
     attributes::from_fn_type(ccx, fn_type).apply_llfn(llfn);
     llfn
 }

src/librustc_trans/trans/intrinsic.rs

@@ -15,6 +15,7 @@ use intrinsics::{self, Intrinsic};
 use libc;
 use llvm;
 use llvm::{SequentiallyConsistent, Acquire, Release, AtomicXchg, ValueRef, TypeKind};
+use middle::infer;
 use middle::subst;
 use middle::subst::FnSpace;
 use trans::adt;
@@ -170,13 +171,10 @@ pub fn trans_intrinsic_call<'a, 'blk, 'tcx>(mut bcx: Block<'blk, 'tcx>,
 
     let _icx = push_ctxt("trans_intrinsic_call");
 
-    let (arg_tys, ret_ty) = match callee_ty.sty {
-        ty::TyBareFn(_, ref f) => {
-            (bcx.tcx().erase_late_bound_regions(&f.sig.inputs()),
-             bcx.tcx().erase_late_bound_regions(&f.sig.output()))
-        }
-        _ => panic!("expected bare_fn in trans_intrinsic_call")
-    };
+    let sig = ccx.tcx().erase_late_bound_regions(callee_ty.fn_sig());
+    let sig = infer::normalize_associated_type(ccx.tcx(), &sig);
+    let arg_tys = sig.inputs;
+    let ret_ty = sig.output;
     let foreign_item = tcx.map.expect_foreign_item(node);
     let name = foreign_item.name.as_str();
 
@@ -1330,12 +1328,9 @@ fn generic_simd_intrinsic<'blk, 'tcx, 'a>
 
 
     let tcx = bcx.tcx();
-    let arg_tys = match callee_ty.sty {
-        ty::TyBareFn(_, ref f) => {
-            bcx.tcx().erase_late_bound_regions(&f.sig.inputs())
-        }
-        _ => unreachable!()
-    };
+    let sig = tcx.erase_late_bound_regions(callee_ty.fn_sig());
+    let sig = infer::normalize_associated_type(tcx, &sig);
+    let arg_tys = sig.inputs;
 
     // every intrinsic takes a SIMD vector as its first argument
     require_simd!(arg_tys[0], "input");

src/librustc_trans/trans/meth.rs

@@ -12,6 +12,7 @@ use arena::TypedArena;
 use back::link;
 use llvm::{ValueRef, get_params};
 use middle::def_id::DefId;
+use middle::infer;
 use middle::subst::{Subst, Substs};
 use middle::subst::VecPerParamSpace;
 use middle::subst;
@@ -522,6 +523,7 @@ fn trans_object_shim<'a, 'tcx>(
     let llfn = declare::define_internal_rust_fn(ccx, &function_name, shim_fn_ty);
 
     let sig = ccx.tcx().erase_late_bound_regions(&fty.sig);
+    let sig = infer::normalize_associated_type(ccx.tcx(), &sig);
 
     let empty_substs = tcx.mk_substs(Substs::trans_empty());
     let (block_arena, fcx): (TypedArena<_>, FunctionContext);

src/librustc_trans/trans/type_of.rs

@@ -11,6 +11,7 @@
 #![allow(non_camel_case_types)]
 
 use middle::def_id::DefId;
+use middle::infer;
 use middle::subst;
 use trans::adt;
 use trans::common::*;
@@ -89,24 +90,25 @@ pub fn untuple_arguments<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
 
 pub fn type_of_rust_fn<'a, 'tcx>(cx: &CrateContext<'a, 'tcx>,
                                  llenvironment_type: Option<Type>,
-                                 sig: &ty::Binder<ty::FnSig<'tcx>>,
+                                 sig: &ty::FnSig<'tcx>,
                                  abi: abi::Abi)
                                  -> Type
 {
     debug!("type_of_rust_fn(sig={:?},abi={:?})",
            sig,
            abi);
 
-    let sig = cx.tcx().erase_late_bound_regions(sig);
     assert!(!sig.variadic); // rust fns are never variadic
 
     let mut atys: Vec<Type> = Vec::new();
 
     // First, munge the inputs, if this has the `rust-call` ABI.
-    let inputs = &if abi == abi::RustCall {
-        untuple_arguments(cx, &sig.inputs)
+    let inputs_temp;
+    let inputs = if abi == abi::RustCall {
+        inputs_temp = untuple_arguments(cx, &sig.inputs);
+        &inputs_temp
     } else {
-        sig.inputs
+        &sig.inputs
     };
 
     // Arg 0: Output pointer.
@@ -155,7 +157,9 @@ pub fn type_of_fn_from_ty<'a, 'tcx>(cx: &CrateContext<'a, 'tcx>, fty: Ty<'tcx>)
             // FIXME(#19925) once fn item types are
             // zero-sized, we'll need to do something here
             if f.abi == abi::Rust || f.abi == abi::RustCall {
-                type_of_rust_fn(cx, None, &f.sig, f.abi)
+                let sig = cx.tcx().erase_late_bound_regions(&f.sig);
+                let sig = infer::normalize_associated_type(cx.tcx(), &sig);
+                type_of_rust_fn(cx, None, &sig, f.abi)
             } else {
                 foreign::lltype_for_foreign_fn(cx, fty)
             }

src/test/run-pass/issue-23406.rs

@@ -0,0 +1,23 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+trait Inner {
+    type T;
+}
+
+impl<'a> Inner for &'a i32 {
+    type T = i32;
+}
+
+fn f<'a>(x: &'a i32) -> <&'a i32 as Inner>::T {
+    *x
+}
+
+fn main() {}