From 261a91519d57590283b250ea9dc1d924b01d4dd6 Mon Sep 17 00:00:00 2001
From: Yuki OKUSHI <huyuumi.dev@gmail.com>
Date: Fri, 29 Mar 2019 06:44:31 +0900
Subject: [PATCH 01/30] Use platform dependent mcount function

---
 src/librustc_codegen_llvm/attributes.rs | 30 ++++++++++++++++++++++++-
 src/test/codegen/instrument-mcount.rs   |  7 ++++++
 2 files changed, 36 insertions(+), 1 deletion(-)
 create mode 100644 src/test/codegen/instrument-mcount.rs

diff --git a/src/librustc_codegen_llvm/attributes.rs b/src/librustc_codegen_llvm/attributes.rs
index 71e7535313f7..e765b986d623 100644
--- a/src/librustc_codegen_llvm/attributes.rs
+++ b/src/librustc_codegen_llvm/attributes.rs
@@ -77,9 +77,37 @@ pub fn set_instrument_function(cx: &CodegenCx<'ll, '_>, llfn: &'ll Value) {
     if cx.sess().instrument_mcount() {
         // Similar to `clang -pg` behavior. Handled by the
         // `post-inline-ee-instrument` LLVM pass.
+
+        // The function name varies on platforms.
+        // See test/CodeGen/mcount.c in clang.
+        let mcount_name = if cfg!(target_os = "netbsd") {
+            const_cstr!("__mcount")
+        } else if cfg!(any(
+                target_arch = "mips", target_arch = "mips64",
+                target_arch = "powerpc", target_arch = "powerpc64")) {
+            const_cstr!("_mcount")
+        } else if cfg!(target_os = "darwin") {
+            const_cstr!("\01mcount")
+        } else if cfg!(target_arch = "aarch64")
+            && (cfg!(target_os = "linux")
+                || (cfg!(target_os = "unknown") && cfg!(target_env = "gnu")))
+        {
+            const_cstr!("\01_mcount")
+        } else if cfg!(target_arch = "arm")
+            && cfg!(any(target_os = "linux", target_os = "unknown"))
+        {
+            if cfg!(target_env = "gnu") {
+                const_cstr!("\01__gnu_mcount_nc")
+            } else {
+                const_cstr!("\01mcount")
+            }
+        } else {
+            const_cstr!("mcount")
+        };
+
         llvm::AddFunctionAttrStringValue(
             llfn, llvm::AttributePlace::Function,
-            const_cstr!("instrument-function-entry-inlined"), const_cstr!("mcount"));
+            const_cstr!("instrument-function-entry-inlined"), mcount_name);
     }
 }
 
diff --git a/src/test/codegen/instrument-mcount.rs b/src/test/codegen/instrument-mcount.rs
new file mode 100644
index 000000000000..bd01556d986a
--- /dev/null
+++ b/src/test/codegen/instrument-mcount.rs
@@ -0,0 +1,7 @@
+// ignore-tidy-linelength
+// compile-flags: -Z instrument-mcount
+
+#![crate_type = "lib"]
+
+// CHECK: attributes #{{.*}} "instrument-function-entry-inlined"="{{_*}}mcount" "no-frame-pointer-elim"="true"
+pub fn foo() {}

From 5b7f4e9e2106f5e83fc650e8185d59a57e27ad09 Mon Sep 17 00:00:00 2001
From: Eduard-Mihai Burtescu <edy.burt@gmail.com>
Date: Fri, 29 Mar 2019 07:44:54 +0200
Subject: [PATCH 02/30] rustc_target: factor out common fields of non-Single
 Variants.

---
 src/librustc/ty/layout.rs                     | 57 +++++++-----
 .../debuginfo/metadata.rs                     | 68 ++++++++++-----
 src/librustc_codegen_llvm/type_of.rs          |  8 +-
 src/librustc_codegen_ssa/mir/place.rs         | 36 ++++----
 src/librustc_codegen_ssa/mir/rvalue.rs        |  3 +-
 src/librustc_lint/types.rs                    | 87 ++++++++++---------
 src/librustc_mir/interpret/cast.rs            |  3 +-
 src/librustc_mir/interpret/operand.rs         | 16 ++--
 src/librustc_mir/interpret/place.rs           | 18 ++--
 src/librustc_mir/interpret/visitor.rs         |  3 +-
 src/librustc_target/abi/call/x86_64.rs        |  3 +-
 src/librustc_target/abi/mod.rs                | 25 +++---
 12 files changed, 193 insertions(+), 134 deletions(-)

diff --git a/src/librustc/ty/layout.rs b/src/librustc/ty/layout.rs
index 7d2b21b9aecd..e01b50113b9f 100644
--- a/src/librustc/ty/layout.rs
+++ b/src/librustc/ty/layout.rs
@@ -913,11 +913,13 @@ impl<'a, 'tcx> LayoutCx<'tcx, TyCtxt<'a, 'tcx, 'tcx>> {
                             }
 
                             return Ok(tcx.intern_layout(LayoutDetails {
-                                variants: Variants::NicheFilling {
-                                    dataful_variant: i,
-                                    niche_variants,
-                                    niche: niche_scalar,
-                                    niche_start,
+                                variants: Variants::Multiple {
+                                    discr: niche_scalar,
+                                    discr_kind: DiscriminantKind::Niche {
+                                        dataful_variant: i,
+                                        niche_variants,
+                                        niche_start,
+                                    },
                                     variants: st,
                                 },
                                 fields: FieldPlacement::Arbitrary {
@@ -1137,8 +1139,9 @@ impl<'a, 'tcx> LayoutCx<'tcx, TyCtxt<'a, 'tcx, 'tcx>> {
                 }
 
                 tcx.intern_layout(LayoutDetails {
-                    variants: Variants::Tagged {
-                        tag,
+                    variants: Variants::Multiple {
+                        discr: tag,
+                        discr_kind: DiscriminantKind::Tag,
                         variants: layout_variants,
                     },
                     fields: FieldPlacement::Arbitrary {
@@ -1293,8 +1296,7 @@ impl<'a, 'tcx> LayoutCx<'tcx, TyCtxt<'a, 'tcx, 'tcx>> {
                 }
             }
 
-            Variants::NicheFilling { .. } |
-            Variants::Tagged { .. } => {
+            Variants::Multiple { ref discr, ref discr_kind, .. } => {
                 debug!("print-type-size `{:#?}` adt general variants def {}",
                        layout.ty, adt_def.variants.len());
                 let variant_infos: Vec<_> =
@@ -1306,8 +1308,8 @@ impl<'a, 'tcx> LayoutCx<'tcx, TyCtxt<'a, 'tcx, 'tcx>> {
                                            layout.for_variant(self, i))
                     })
                     .collect();
-                record(adt_kind.into(), adt_packed, match layout.variants {
-                    Variants::Tagged { ref tag, .. } => Some(tag.value.size(self)),
+                record(adt_kind.into(), adt_packed, match discr_kind {
+                    DiscriminantKind::Tag => Some(discr.value.size(self)),
                     _ => None
                 }, variant_infos);
             }
@@ -1627,8 +1629,7 @@ impl<'a, 'tcx, C> TyLayoutMethods<'tcx, C> for Ty<'tcx>
                 })
             }
 
-            Variants::NicheFilling { ref variants, .. } |
-            Variants::Tagged { ref variants, .. } => {
+            Variants::Multiple { ref variants, .. } => {
                 &variants[variant_index]
             }
         };
@@ -1735,8 +1736,7 @@ impl<'a, 'tcx, C> TyLayoutMethods<'tcx, C> for Ty<'tcx>
                     }
 
                     // Discriminant field for enums (where applicable).
-                    Variants::Tagged { tag: ref discr, .. } |
-                    Variants::NicheFilling { niche: ref discr, .. } => {
+                    Variants::Multiple { ref discr, .. } => {
                         assert_eq!(i, 0);
                         let layout = LayoutDetails::scalar(cx, discr.clone());
                         return MaybeResult::from_ok(TyLayout {
@@ -1881,26 +1881,37 @@ impl<'a> HashStable<StableHashingContext<'a>> for Variants {
             Single { index } => {
                 index.hash_stable(hcx, hasher);
             }
-            Tagged {
-                ref tag,
+            Multiple {
+                ref discr,
+                ref discr_kind,
                 ref variants,
             } => {
-                tag.hash_stable(hcx, hasher);
+                discr.hash_stable(hcx, hasher);
+                discr_kind.hash_stable(hcx, hasher);
                 variants.hash_stable(hcx, hasher);
             }
-            NicheFilling {
+        }
+    }
+}
+
+impl<'a> HashStable<StableHashingContext<'a>> for DiscriminantKind {
+    fn hash_stable<W: StableHasherResult>(&self,
+                                          hcx: &mut StableHashingContext<'a>,
+                                          hasher: &mut StableHasher<W>) {
+        use crate::ty::layout::DiscriminantKind::*;
+        mem::discriminant(self).hash_stable(hcx, hasher);
+
+        match *self {
+            Tag => {}
+            Niche {
                 dataful_variant,
                 ref niche_variants,
-                ref niche,
                 niche_start,
-                ref variants,
             } => {
                 dataful_variant.hash_stable(hcx, hasher);
                 niche_variants.start().hash_stable(hcx, hasher);
                 niche_variants.end().hash_stable(hcx, hasher);
-                niche.hash_stable(hcx, hasher);
                 niche_start.hash_stable(hcx, hasher);
-                variants.hash_stable(hcx, hasher);
             }
         }
     }
diff --git a/src/librustc_codegen_llvm/debuginfo/metadata.rs b/src/librustc_codegen_llvm/debuginfo/metadata.rs
index 042a8c60cfaa..d2bbc00868a4 100644
--- a/src/librustc_codegen_llvm/debuginfo/metadata.rs
+++ b/src/librustc_codegen_llvm/debuginfo/metadata.rs
@@ -1235,7 +1235,11 @@ impl EnumMemberDescriptionFactory<'ll, 'tcx> {
                     }
                 ]
             }
-            layout::Variants::Tagged { ref variants, .. } => {
+            layout::Variants::Multiple {
+                discr_kind: layout::DiscriminantKind::Tag,
+                ref variants,
+                ..
+            } => {
                 let discriminant_info = if fallback {
                     RegularDiscriminant(self.discriminant_type_metadata
                                         .expect(""))
@@ -1277,12 +1281,14 @@ impl EnumMemberDescriptionFactory<'ll, 'tcx> {
                     }
                 }).collect()
             }
-            layout::Variants::NicheFilling {
-                ref niche_variants,
-                niche_start,
+            layout::Variants::Multiple {
+                discr_kind: layout::DiscriminantKind::Niche {
+                    ref niche_variants,
+                    niche_start,
+                    dataful_variant,
+                },
+                ref discr,
                 ref variants,
-                dataful_variant,
-                ref niche,
             } => {
                 if fallback {
                     let variant = self.layout.for_variant(cx, dataful_variant);
@@ -1369,7 +1375,11 @@ impl EnumMemberDescriptionFactory<'ll, 'tcx> {
                             let value = (i.as_u32() as u128)
                                 .wrapping_sub(niche_variants.start().as_u32() as u128)
                                 .wrapping_add(niche_start);
-                            let value = truncate(value, niche.value.size(cx));
+                            let value = truncate(value, discr.value.size(cx));
+                            // NOTE(eddyb) do *NOT* remove this assert, until
+                            // we pass the full 128-bit value to LLVM, otherwise
+                            // truncation will be silent and remain undetected.
+                            assert_eq!(value as u64 as u128, value);
                             Some(value as u64)
                         };
 
@@ -1586,8 +1596,11 @@ fn prepare_enum_metadata(
     let layout = cx.layout_of(enum_type);
 
     match (&layout.abi, &layout.variants) {
-        (&layout::Abi::Scalar(_), &layout::Variants::Tagged {ref tag, .. }) =>
-            return FinalMetadata(discriminant_type_metadata(tag.value)),
+        (&layout::Abi::Scalar(_), &layout::Variants::Multiple {
+            discr_kind: layout::DiscriminantKind::Tag,
+            ref discr,
+            ..
+        }) => return FinalMetadata(discriminant_type_metadata(discr.value)),
         _ => {}
     }
 
@@ -1599,9 +1612,16 @@ fn prepare_enum_metadata(
     if use_enum_fallback(cx) {
         let discriminant_type_metadata = match layout.variants {
             layout::Variants::Single { .. } |
-            layout::Variants::NicheFilling { .. } => None,
-            layout::Variants::Tagged { ref tag, .. } => {
-                Some(discriminant_type_metadata(tag.value))
+            layout::Variants::Multiple {
+                discr_kind: layout::DiscriminantKind::Niche { .. },
+                ..
+            } => None,
+            layout::Variants::Multiple {
+                discr_kind: layout::DiscriminantKind::Tag,
+                ref discr,
+                ..
+            } => {
+                Some(discriminant_type_metadata(discr.value))
             }
         };
 
@@ -1636,16 +1656,20 @@ fn prepare_enum_metadata(
         );
     }
 
-    let discriminator_metadata = match &layout.variants {
+    let discriminator_metadata = match layout.variants {
         // A single-variant enum has no discriminant.
-        &layout::Variants::Single { .. } => None,
+        layout::Variants::Single { .. } => None,
 
-        &layout::Variants::NicheFilling { ref niche, .. } => {
+        layout::Variants::Multiple {
+            discr_kind: layout::DiscriminantKind::Niche { .. },
+            ref discr,
+            ..
+        } => {
             // Find the integer type of the correct size.
-            let size = niche.value.size(cx);
-            let align = niche.value.align(cx);
+            let size = discr.value.size(cx);
+            let align = discr.value.align(cx);
 
-            let discr_type = match niche.value {
+            let discr_type = match discr.value {
                 layout::Int(t, _) => t,
                 layout::Float(layout::FloatTy::F32) => Integer::I32,
                 layout::Float(layout::FloatTy::F64) => Integer::I64,
@@ -1668,8 +1692,12 @@ fn prepare_enum_metadata(
             }
         },
 
-        &layout::Variants::Tagged { ref tag, .. } => {
-            let discr_type = tag.value.to_ty(cx.tcx);
+        layout::Variants::Multiple {
+            discr_kind: layout::DiscriminantKind::Tag,
+            ref discr,
+            ..
+        } => {
+            let discr_type = discr.value.to_ty(cx.tcx);
             let (size, align) = cx.size_and_align_of(discr_type);
 
             let discr_metadata = basic_type_metadata(cx, discr_type);
diff --git a/src/librustc_codegen_llvm/type_of.rs b/src/librustc_codegen_llvm/type_of.rs
index fb5624d56078..020447608eeb 100644
--- a/src/librustc_codegen_llvm/type_of.rs
+++ b/src/librustc_codegen_llvm/type_of.rs
@@ -452,7 +452,13 @@ impl<'tcx> LayoutLlvmExt<'tcx> for TyLayout<'tcx> {
 
             _ => {
                 let mut data_variant = match self.variants {
-                    layout::Variants::NicheFilling { dataful_variant, .. } => {
+                    layout::Variants::Multiple {
+                        discr_kind: layout::DiscriminantKind::Niche {
+                            dataful_variant,
+                            ..
+                        },
+                        ..
+                    } => {
                         // Only the niche itself is always initialized,
                         // so only check for a pointer at its offset.
                         //
diff --git a/src/librustc_codegen_ssa/mir/place.rs b/src/librustc_codegen_ssa/mir/place.rs
index 7cafa0088a01..39d7638ae088 100644
--- a/src/librustc_codegen_ssa/mir/place.rs
+++ b/src/librustc_codegen_ssa/mir/place.rs
@@ -216,37 +216,36 @@ impl<'a, 'tcx: 'a, V: CodegenObject> PlaceRef<'tcx, V> {
         if self.layout.abi.is_uninhabited() {
             return bx.cx().const_undef(cast_to);
         }
-        match self.layout.variants {
+        let (discr_scalar, discr_kind) = match self.layout.variants {
             layout::Variants::Single { index } => {
                 let discr_val = self.layout.ty.ty_adt_def().map_or(
                     index.as_u32() as u128,
                     |def| def.discriminant_for_variant(bx.cx().tcx(), index).val);
                 return bx.cx().const_uint_big(cast_to, discr_val);
             }
-            layout::Variants::Tagged { .. } |
-            layout::Variants::NicheFilling { .. } => {},
-        }
+            layout::Variants::Multiple { ref discr, ref discr_kind, .. } => {
+                (discr, discr_kind)
+            }
+        };
 
         let discr = self.project_field(bx, 0);
         let lldiscr = bx.load_operand(discr).immediate();
-        match self.layout.variants {
-            layout::Variants::Single { .. } => bug!(),
-            layout::Variants::Tagged { ref tag, .. } => {
-                let signed = match tag.value {
+        match *discr_kind {
+            layout::DiscriminantKind::Tag => {
+                let signed = match discr_scalar.value {
                     // We use `i1` for bytes that are always `0` or `1`,
                     // e.g., `#[repr(i8)] enum E { A, B }`, but we can't
                     // let LLVM interpret the `i1` as signed, because
                     // then `i1 1` (i.e., E::B) is effectively `i8 -1`.
-                    layout::Int(_, signed) => !tag.is_bool() && signed,
+                    layout::Int(_, signed) => !discr_scalar.is_bool() && signed,
                     _ => false
                 };
                 bx.intcast(lldiscr, cast_to, signed)
             }
-            layout::Variants::NicheFilling {
+            layout::DiscriminantKind::Niche {
                 dataful_variant,
                 ref niche_variants,
                 niche_start,
-                ..
             } => {
                 let niche_llty = bx.cx().immediate_backend_type(discr.layout);
                 if niche_variants.start() == niche_variants.end() {
@@ -291,7 +290,10 @@ impl<'a, 'tcx: 'a, V: CodegenObject> PlaceRef<'tcx, V> {
             layout::Variants::Single { index } => {
                 assert_eq!(index, variant_index);
             }
-            layout::Variants::Tagged { .. } => {
+            layout::Variants::Multiple {
+                discr_kind: layout::DiscriminantKind::Tag,
+                ..
+            } => {
                 let ptr = self.project_field(bx, 0);
                 let to = self.layout.ty.ty_adt_def().unwrap()
                     .discriminant_for_variant(bx.tcx(), variant_index)
@@ -301,10 +303,12 @@ impl<'a, 'tcx: 'a, V: CodegenObject> PlaceRef<'tcx, V> {
                     ptr.llval,
                     ptr.align);
             }
-            layout::Variants::NicheFilling {
-                dataful_variant,
-                ref niche_variants,
-                niche_start,
+            layout::Variants::Multiple {
+                discr_kind: layout::DiscriminantKind::Niche {
+                    dataful_variant,
+                    ref niche_variants,
+                    niche_start,
+                },
                 ..
             } => {
                 if variant_index != dataful_variant {
diff --git a/src/librustc_codegen_ssa/mir/rvalue.rs b/src/librustc_codegen_ssa/mir/rvalue.rs
index b8131671320e..6815d08321ef 100644
--- a/src/librustc_codegen_ssa/mir/rvalue.rs
+++ b/src/librustc_codegen_ssa/mir/rvalue.rs
@@ -303,8 +303,7 @@ impl<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                                     });
                                 }
                             }
-                            layout::Variants::Tagged { .. } |
-                            layout::Variants::NicheFilling { .. } => {},
+                            layout::Variants::Multiple { .. } => {},
                         }
                         let llval = operand.immediate();
 
diff --git a/src/librustc_lint/types.rs b/src/librustc_lint/types.rs
index 4ad1a00afe97..494a9bb73ed4 100644
--- a/src/librustc_lint/types.rs
+++ b/src/librustc_lint/types.rs
@@ -842,51 +842,56 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for VariantSizeDifferences {
             let item_def_id = cx.tcx.hir().local_def_id_from_hir_id(it.hir_id);
             let t = cx.tcx.type_of(item_def_id);
             let ty = cx.tcx.erase_regions(&t);
-            match cx.layout_of(ty) {
-                Ok(layout) => {
-                    let variants = &layout.variants;
-                    if let layout::Variants::Tagged { ref variants, ref tag, .. } = variants {
-                        let discr_size = tag.value.size(&cx.tcx).bytes();
-
-                        debug!("enum `{}` is {} bytes large with layout:\n{:#?}",
-                               t, layout.size.bytes(), layout);
-
-                        let (largest, slargest, largest_index) = enum_definition.variants
-                            .iter()
-                            .zip(variants)
-                            .map(|(variant, variant_layout)| {
-                                // Subtract the size of the enum discriminant.
-                                let bytes = variant_layout.size.bytes().saturating_sub(discr_size);
-
-                                debug!("- variant `{}` is {} bytes large",
-                                       variant.node.ident,
-                                       bytes);
-                                bytes
-                            })
-                            .enumerate()
-                            .fold((0, 0, 0), |(l, s, li), (idx, size)| if size > l {
-                                (size, l, idx)
-                            } else if size > s {
-                                (l, size, li)
-                            } else {
-                                (l, s, li)
-                            });
-
-                        // We only warn if the largest variant is at least thrice as large as
-                        // the second-largest.
-                        if largest > slargest * 3 && slargest > 0 {
-                            cx.span_lint(VARIANT_SIZE_DIFFERENCES,
-                                            enum_definition.variants[largest_index].span,
-                                            &format!("enum variant is more than three times \
-                                                      larger ({} bytes) than the next largest",
-                                                     largest));
-                        }
-                    }
-                }
+            let layout = match cx.layout_of(ty) {
+                Ok(layout) => layout,
                 Err(ty::layout::LayoutError::Unknown(_)) => return,
                 Err(err @ ty::layout::LayoutError::SizeOverflow(_)) => {
                     bug!("failed to get layout for `{}`: {}", t, err);
                 }
+            };
+            let (variants, tag) = match layout.variants {
+                layout::Variants::Multiple {
+                    discr_kind: layout::DiscriminantKind::Tag,
+                    ref discr,
+                    ref variants,
+                } => (variants, discr),
+                _ => return,
+            };
+
+            let discr_size = tag.value.size(&cx.tcx).bytes();
+
+            debug!("enum `{}` is {} bytes large with layout:\n{:#?}",
+                   t, layout.size.bytes(), layout);
+
+            let (largest, slargest, largest_index) = enum_definition.variants
+                .iter()
+                .zip(variants)
+                .map(|(variant, variant_layout)| {
+                    // Subtract the size of the enum discriminant.
+                    let bytes = variant_layout.size.bytes().saturating_sub(discr_size);
+
+                    debug!("- variant `{}` is {} bytes large",
+                           variant.node.ident,
+                           bytes);
+                    bytes
+                })
+                .enumerate()
+                .fold((0, 0, 0), |(l, s, li), (idx, size)| if size > l {
+                    (size, l, idx)
+                } else if size > s {
+                    (l, size, li)
+                } else {
+                    (l, s, li)
+                });
+
+            // We only warn if the largest variant is at least thrice as large as
+            // the second-largest.
+            if largest > slargest * 3 && slargest > 0 {
+                cx.span_lint(VARIANT_SIZE_DIFFERENCES,
+                                enum_definition.variants[largest_index].span,
+                                &format!("enum variant is more than three times \
+                                          larger ({} bytes) than the next largest",
+                                         largest));
             }
         }
     }
diff --git a/src/librustc_mir/interpret/cast.rs b/src/librustc_mir/interpret/cast.rs
index 003c2182d0b4..ba61b03ea673 100644
--- a/src/librustc_mir/interpret/cast.rs
+++ b/src/librustc_mir/interpret/cast.rs
@@ -64,8 +64,7 @@ impl<'a, 'mir, 'tcx, M: Machine<'a, 'mir, 'tcx>> InterpretCx<'a, 'mir, 'tcx, M>
                                     dest);
                             }
                         }
-                        layout::Variants::Tagged { .. } |
-                        layout::Variants::NicheFilling { .. } => {},
+                        layout::Variants::Multiple { .. } => {},
                     }
 
                     let dest_val = self.cast_scalar(src.to_scalar()?, src.layout, dest.layout)?;
diff --git a/src/librustc_mir/interpret/operand.rs b/src/librustc_mir/interpret/operand.rs
index 15b6d5c914d2..38a9371b9272 100644
--- a/src/librustc_mir/interpret/operand.rs
+++ b/src/librustc_mir/interpret/operand.rs
@@ -610,25 +610,24 @@ impl<'a, 'mir, 'tcx, M: Machine<'a, 'mir, 'tcx>> InterpretCx<'a, 'mir, 'tcx, M>
     ) -> EvalResult<'tcx, (u128, VariantIdx)> {
         trace!("read_discriminant_value {:#?}", rval.layout);
 
-        match rval.layout.variants {
+        let discr_kind = match rval.layout.variants {
             layout::Variants::Single { index } => {
                 let discr_val = rval.layout.ty.ty_adt_def().map_or(
                     index.as_u32() as u128,
                     |def| def.discriminant_for_variant(*self.tcx, index).val);
                 return Ok((discr_val, index));
             }
-            layout::Variants::Tagged { .. } |
-            layout::Variants::NicheFilling { .. } => {},
-        }
+            layout::Variants::Multiple { ref discr_kind, .. } => discr_kind,
+        };
+
         // read raw discriminant value
         let discr_op = self.operand_field(rval, 0)?;
         let discr_val = self.read_immediate(discr_op)?;
         let raw_discr = discr_val.to_scalar_or_undef();
         trace!("discr value: {:?}", raw_discr);
         // post-process
-        Ok(match rval.layout.variants {
-            layout::Variants::Single { .. } => bug!(),
-            layout::Variants::Tagged { .. } => {
+        Ok(match *discr_kind {
+            layout::DiscriminantKind::Tag => {
                 let bits_discr = match raw_discr.to_bits(discr_val.layout.size) {
                     Ok(raw_discr) => raw_discr,
                     Err(_) => return err!(InvalidDiscriminant(raw_discr.erase_tag())),
@@ -657,11 +656,10 @@ impl<'a, 'mir, 'tcx, M: Machine<'a, 'mir, 'tcx>> InterpretCx<'a, 'mir, 'tcx, M>
                     .ok_or_else(|| EvalErrorKind::InvalidDiscriminant(raw_discr.erase_tag()))?;
                 (real_discr, index.0)
             },
-            layout::Variants::NicheFilling {
+            layout::DiscriminantKind::Niche {
                 dataful_variant,
                 ref niche_variants,
                 niche_start,
-                ..
             } => {
                 let variants_start = niche_variants.start().as_u32() as u128;
                 let variants_end = niche_variants.end().as_u32() as u128;
diff --git a/src/librustc_mir/interpret/place.rs b/src/librustc_mir/interpret/place.rs
index 82b92acdb764..4d51772d5ea1 100644
--- a/src/librustc_mir/interpret/place.rs
+++ b/src/librustc_mir/interpret/place.rs
@@ -958,7 +958,11 @@ where
             layout::Variants::Single { index } => {
                 assert_eq!(index, variant_index);
             }
-            layout::Variants::Tagged { ref tag, .. } => {
+            layout::Variants::Multiple {
+                discr_kind: layout::DiscriminantKind::Tag,
+                ref discr,
+                ..
+            } => {
                 let adt_def = dest.layout.ty.ty_adt_def().unwrap();
                 assert!(variant_index.as_usize() < adt_def.variants.len());
                 let discr_val = adt_def
@@ -968,16 +972,18 @@ where
                 // raw discriminants for enums are isize or bigger during
                 // their computation, but the in-memory tag is the smallest possible
                 // representation
-                let size = tag.value.size(self);
+                let size = discr.value.size(self);
                 let discr_val = truncate(discr_val, size);
 
                 let discr_dest = self.place_field(dest, 0)?;
                 self.write_scalar(Scalar::from_uint(discr_val, size), discr_dest)?;
             }
-            layout::Variants::NicheFilling {
-                dataful_variant,
-                ref niche_variants,
-                niche_start,
+            layout::Variants::Multiple {
+                discr_kind: layout::DiscriminantKind::Niche {
+                    dataful_variant,
+                    ref niche_variants,
+                    niche_start,
+                },
                 ..
             } => {
                 assert!(
diff --git a/src/librustc_mir/interpret/visitor.rs b/src/librustc_mir/interpret/visitor.rs
index 90d4fff42183..05343ac66d96 100644
--- a/src/librustc_mir/interpret/visitor.rs
+++ b/src/librustc_mir/interpret/visitor.rs
@@ -241,8 +241,7 @@ macro_rules! make_value_visitor {
                 // If this is a multi-variant layout, we have find the right one and proceed with
                 // that.
                 match v.layout().variants {
-                    layout::Variants::NicheFilling { .. } |
-                    layout::Variants::Tagged { .. } => {
+                    layout::Variants::Multiple { .. } => {
                         let op = v.to_op(self.ecx())?;
                         let idx = self.ecx().read_discriminant(op)?.1;
                         let inner = v.project_downcast(self.ecx(), idx)?;
diff --git a/src/librustc_target/abi/call/x86_64.rs b/src/librustc_target/abi/call/x86_64.rs
index 680e529b108e..b68c70224c95 100644
--- a/src/librustc_target/abi/call/x86_64.rs
+++ b/src/librustc_target/abi/call/x86_64.rs
@@ -61,8 +61,7 @@ fn classify_arg<'a, Ty, C>(cx: &C, arg: &ArgType<'a, Ty>)
                         }
                         return Ok(());
                     }
-                    abi::Variants::Tagged { .. } |
-                    abi::Variants::NicheFilling { .. } => return Err(Memory),
+                    abi::Variants::Multiple { .. } => return Err(Memory),
                 }
             }
 
diff --git a/src/librustc_target/abi/mod.rs b/src/librustc_target/abi/mod.rs
index 8b96a8c1658b..235b530a7ef2 100644
--- a/src/librustc_target/abi/mod.rs
+++ b/src/librustc_target/abi/mod.rs
@@ -828,15 +828,22 @@ pub enum Variants {
         index: VariantIdx,
     },
 
-    /// General-case enums: for each case there is a struct, and they all have
-    /// all space reserved for the tag, and their first field starts
-    /// at a non-0 offset, after where the tag would go.
-    Tagged {
-        tag: Scalar,
+    /// Enums with more than one inhabited variant: for each case there is
+    /// a struct, and they all have space reserved for the discriminant,
+    /// which is the sole field of the enum layout.
+    Multiple {
+        discr: Scalar,
+        discr_kind: DiscriminantKind,
         variants: IndexVec<VariantIdx, LayoutDetails>,
     },
+}
+
+#[derive(PartialEq, Eq, Hash, Debug)]
+pub enum DiscriminantKind {
+    /// Integer tag holding the discriminant value itself.
+    Tag,
 
-    /// Multiple cases distinguished by a niche (values invalid for a type):
+    /// Niche (values invalid for a type) encoding the discriminant:
     /// the variant `dataful_variant` contains a niche at an arbitrary
     /// offset (field 0 of the enum), which for a variant with discriminant
     /// `d` is set to `(d - niche_variants.start).wrapping_add(niche_start)`.
@@ -844,13 +851,11 @@ pub enum Variants {
     /// For example, `Option<(usize, &T)>`  is represented such that
     /// `None` has a null pointer for the second tuple field, and
     /// `Some` is the identity function (with a non-null reference).
-    NicheFilling {
+    Niche {
         dataful_variant: VariantIdx,
         niche_variants: RangeInclusive<VariantIdx>,
-        niche: Scalar,
         niche_start: u128,
-        variants: IndexVec<VariantIdx, LayoutDetails>,
-    }
+    },
 }
 
 #[derive(PartialEq, Eq, Hash, Debug)]

From 8381cbab1a80b2c71df79fb8c33f480cfbca52bb Mon Sep 17 00:00:00 2001
From: Yuki OKUSHI <huyuumi.dev@gmail.com>
Date: Sat, 30 Mar 2019 18:50:19 +0900
Subject: [PATCH 03/30] Add target_mcount option

---
 src/librustc_target/spec/aarch64_unknown_linux_gnu.rs     | 1 +
 src/librustc_target/spec/aarch64_unknown_linux_musl.rs    | 1 +
 src/librustc_target/spec/aarch64_unknown_netbsd.rs        | 7 +++++--
 src/librustc_target/spec/arm_unknown_linux_gnueabi.rs     | 1 +
 src/librustc_target/spec/arm_unknown_linux_gnueabihf.rs   | 1 +
 src/librustc_target/spec/arm_unknown_linux_musleabi.rs    | 1 +
 src/librustc_target/spec/arm_unknown_linux_musleabihf.rs  | 1 +
 src/librustc_target/spec/armv4t_unknown_linux_gnueabi.rs  | 1 +
 src/librustc_target/spec/armv5te_unknown_linux_gnueabi.rs | 1 +
 .../spec/armv5te_unknown_linux_musleabi.rs                | 1 +
 src/librustc_target/spec/armv6_unknown_freebsd.rs         | 1 +
 src/librustc_target/spec/armv6_unknown_netbsd_eabihf.rs   | 1 +
 src/librustc_target/spec/armv7_unknown_cloudabi_eabihf.rs | 7 +++++--
 src/librustc_target/spec/armv7_unknown_freebsd.rs         | 1 +
 src/librustc_target/spec/armv7_unknown_linux_gnueabihf.rs | 1 +
 .../spec/armv7_unknown_linux_musleabihf.rs                | 1 +
 src/librustc_target/spec/armv7_unknown_netbsd_eabihf.rs   | 1 +
 src/librustc_target/spec/i686_apple_darwin.rs             | 7 +++++--
 src/librustc_target/spec/i686_unknown_netbsd.rs           | 7 +++++--
 src/librustc_target/spec/mips64_unknown_linux_gnuabi64.rs | 1 +
 .../spec/mips64el_unknown_linux_gnuabi64.rs               | 1 +
 src/librustc_target/spec/mips_unknown_linux_gnu.rs        | 1 +
 src/librustc_target/spec/mips_unknown_linux_musl.rs       | 7 +++++--
 src/librustc_target/spec/mips_unknown_linux_uclibc.rs     | 1 +
 src/librustc_target/spec/mipsel_unknown_linux_gnu.rs      | 1 +
 src/librustc_target/spec/mipsel_unknown_linux_musl.rs     | 7 +++++--
 src/librustc_target/spec/mipsel_unknown_linux_uclibc.rs   | 1 +
 src/librustc_target/spec/mipsisa32r6_unknown_linux_gnu.rs | 1 +
 .../spec/mipsisa32r6el_unknown_linux_gnu.rs               | 1 +
 .../spec/mipsisa64r6_unknown_linux_gnuabi64.rs            | 1 +
 .../spec/mipsisa64r6el_unknown_linux_gnuabi64.rs          | 1 +
 src/librustc_target/spec/mod.rs                           | 8 +++++++-
 src/librustc_target/spec/powerpc64_unknown_freebsd.rs     | 7 +++++--
 src/librustc_target/spec/powerpc64_unknown_linux_gnu.rs   | 7 +++++--
 src/librustc_target/spec/powerpc64_unknown_linux_musl.rs  | 7 +++++--
 src/librustc_target/spec/powerpc64le_unknown_linux_gnu.rs | 7 +++++--
 .../spec/powerpc64le_unknown_linux_musl.rs                | 7 +++++--
 src/librustc_target/spec/powerpc_unknown_linux_gnu.rs     | 7 +++++--
 src/librustc_target/spec/powerpc_unknown_linux_gnuspe.rs  | 7 +++++--
 src/librustc_target/spec/powerpc_unknown_linux_musl.rs    | 7 +++++--
 src/librustc_target/spec/powerpc_unknown_netbsd.rs        | 7 +++++--
 src/librustc_target/spec/sparc64_unknown_netbsd.rs        | 7 +++++--
 src/librustc_target/spec/x86_64_apple_darwin.rs           | 7 +++++--
 src/librustc_target/spec/x86_64_rumprun_netbsd.rs         | 7 +++++--
 src/librustc_target/spec/x86_64_unknown_netbsd.rs         | 7 +++++--
 45 files changed, 127 insertions(+), 39 deletions(-)

diff --git a/src/librustc_target/spec/aarch64_unknown_linux_gnu.rs b/src/librustc_target/spec/aarch64_unknown_linux_gnu.rs
index e772d8b532cb..59a285736412 100644
--- a/src/librustc_target/spec/aarch64_unknown_linux_gnu.rs
+++ b/src/librustc_target/spec/aarch64_unknown_linux_gnu.rs
@@ -17,6 +17,7 @@ pub fn target() -> TargetResult {
         linker_flavor: LinkerFlavor::Gcc,
         options: TargetOptions {
             abi_blacklist: super::arm_base::abi_blacklist(),
+            target_mcount: "\01_mcount".to_string(),
             .. base
         },
     })
diff --git a/src/librustc_target/spec/aarch64_unknown_linux_musl.rs b/src/librustc_target/spec/aarch64_unknown_linux_musl.rs
index 8123ee82ed52..781b1322f5ac 100644
--- a/src/librustc_target/spec/aarch64_unknown_linux_musl.rs
+++ b/src/librustc_target/spec/aarch64_unknown_linux_musl.rs
@@ -17,6 +17,7 @@ pub fn target() -> TargetResult {
         linker_flavor: LinkerFlavor::Gcc,
         options: TargetOptions {
             abi_blacklist: super::arm_base::abi_blacklist(),
+            target_mcount: "\01_mcount".to_string(),
             .. base
         },
     })
diff --git a/src/librustc_target/spec/aarch64_unknown_netbsd.rs b/src/librustc_target/spec/aarch64_unknown_netbsd.rs
index 47ae08ade9a6..455cbebb91e2 100644
--- a/src/librustc_target/spec/aarch64_unknown_netbsd.rs
+++ b/src/librustc_target/spec/aarch64_unknown_netbsd.rs
@@ -1,4 +1,4 @@
-use crate::spec::{LinkerFlavor, Target, TargetResult};
+use crate::spec::{LinkerFlavor, Target, TargetOptions, TargetResult};
 
 pub fn target() -> TargetResult {
     let mut base = super::netbsd_base::opts();
@@ -16,6 +16,9 @@ pub fn target() -> TargetResult {
         target_env: String::new(),
         target_vendor: "unknown".to_string(),
         linker_flavor: LinkerFlavor::Gcc,
-        options: base,
+        options: TargetOptions {
+            target_mcount: "__mcount".to_string(),
+            .. base
+        },
     })
 }
diff --git a/src/librustc_target/spec/arm_unknown_linux_gnueabi.rs b/src/librustc_target/spec/arm_unknown_linux_gnueabi.rs
index f291818ba80f..1173d18634e1 100644
--- a/src/librustc_target/spec/arm_unknown_linux_gnueabi.rs
+++ b/src/librustc_target/spec/arm_unknown_linux_gnueabi.rs
@@ -18,6 +18,7 @@ pub fn target() -> TargetResult {
         options: TargetOptions {
             features: "+strict-align,+v6".to_string(),
             abi_blacklist: super::arm_base::abi_blacklist(),
+            target_mcount: "\01__gnu_mcount_nc".to_string(),
             .. base
         },
     })
diff --git a/src/librustc_target/spec/arm_unknown_linux_gnueabihf.rs b/src/librustc_target/spec/arm_unknown_linux_gnueabihf.rs
index 32b509d9721e..6fc7c46be3b1 100644
--- a/src/librustc_target/spec/arm_unknown_linux_gnueabihf.rs
+++ b/src/librustc_target/spec/arm_unknown_linux_gnueabihf.rs
@@ -18,6 +18,7 @@ pub fn target() -> TargetResult {
         options: TargetOptions {
             features: "+strict-align,+v6,+vfp2".to_string(),
             abi_blacklist: super::arm_base::abi_blacklist(),
+            target_mcount: "\01__gnu_mcount_nc".to_string(),
             .. base
         }
     })
diff --git a/src/librustc_target/spec/arm_unknown_linux_musleabi.rs b/src/librustc_target/spec/arm_unknown_linux_musleabi.rs
index 7637577e7e84..7a2a4e85e4a1 100644
--- a/src/librustc_target/spec/arm_unknown_linux_musleabi.rs
+++ b/src/librustc_target/spec/arm_unknown_linux_musleabi.rs
@@ -23,6 +23,7 @@ pub fn target() -> TargetResult {
         linker_flavor: LinkerFlavor::Gcc,
         options: TargetOptions {
             abi_blacklist: super::arm_base::abi_blacklist(),
+            target_mcount: "\01mcount".to_string(),
             .. base
         },
     })
diff --git a/src/librustc_target/spec/arm_unknown_linux_musleabihf.rs b/src/librustc_target/spec/arm_unknown_linux_musleabihf.rs
index 9def151b3ef2..b7aa1952cb0b 100644
--- a/src/librustc_target/spec/arm_unknown_linux_musleabihf.rs
+++ b/src/librustc_target/spec/arm_unknown_linux_musleabihf.rs
@@ -23,6 +23,7 @@ pub fn target() -> TargetResult {
         linker_flavor: LinkerFlavor::Gcc,
         options: TargetOptions {
             abi_blacklist: super::arm_base::abi_blacklist(),
+            target_mcount: "\01mcount".to_string(),
             .. base
         },
     })
diff --git a/src/librustc_target/spec/armv4t_unknown_linux_gnueabi.rs b/src/librustc_target/spec/armv4t_unknown_linux_gnueabi.rs
index 7cd4b14cdebc..59c15f1610de 100644
--- a/src/librustc_target/spec/armv4t_unknown_linux_gnueabi.rs
+++ b/src/librustc_target/spec/armv4t_unknown_linux_gnueabi.rs
@@ -19,6 +19,7 @@ pub fn target() -> TargetResult {
             // Atomic operations provided by compiler-builtins
             max_atomic_width: Some(32),
             abi_blacklist: super::arm_base::abi_blacklist(),
+            target_mcount: "\01__gnu_mcount_nc".to_string(),
             .. base
         }
     })
diff --git a/src/librustc_target/spec/armv5te_unknown_linux_gnueabi.rs b/src/librustc_target/spec/armv5te_unknown_linux_gnueabi.rs
index 15f614827718..a1a61a69d052 100644
--- a/src/librustc_target/spec/armv5te_unknown_linux_gnueabi.rs
+++ b/src/librustc_target/spec/armv5te_unknown_linux_gnueabi.rs
@@ -19,6 +19,7 @@ pub fn target() -> TargetResult {
             // Atomic operations provided by compiler-builtins
             max_atomic_width: Some(32),
             abi_blacklist: super::arm_base::abi_blacklist(),
+            target_mcount: "\01__gnu_mcount_nc".to_string(),
             .. base
         }
     })
diff --git a/src/librustc_target/spec/armv5te_unknown_linux_musleabi.rs b/src/librustc_target/spec/armv5te_unknown_linux_musleabi.rs
index 74915b942ea4..9b44a54715e7 100644
--- a/src/librustc_target/spec/armv5te_unknown_linux_musleabi.rs
+++ b/src/librustc_target/spec/armv5te_unknown_linux_musleabi.rs
@@ -22,6 +22,7 @@ pub fn target() -> TargetResult {
             // Atomic operations provided by compiler-builtins
             max_atomic_width: Some(32),
             abi_blacklist: super::arm_base::abi_blacklist(),
+            target_mcount: "\01mcount".to_string(),
             .. base
         }
     })
diff --git a/src/librustc_target/spec/armv6_unknown_freebsd.rs b/src/librustc_target/spec/armv6_unknown_freebsd.rs
index 39886a16a740..e706c8281d23 100644
--- a/src/librustc_target/spec/armv6_unknown_freebsd.rs
+++ b/src/librustc_target/spec/armv6_unknown_freebsd.rs
@@ -18,6 +18,7 @@ pub fn target() -> TargetResult {
             features: "+v6,+vfp2".to_string(),
             max_atomic_width: Some(64),
             abi_blacklist: super::arm_base::abi_blacklist(),
+            target_mcount: "\01__gnu_mcount_nc".to_string(),
             .. base
         }
     })
diff --git a/src/librustc_target/spec/armv6_unknown_netbsd_eabihf.rs b/src/librustc_target/spec/armv6_unknown_netbsd_eabihf.rs
index e460b6c574a2..b056776bdfb8 100644
--- a/src/librustc_target/spec/armv6_unknown_netbsd_eabihf.rs
+++ b/src/librustc_target/spec/armv6_unknown_netbsd_eabihf.rs
@@ -18,6 +18,7 @@ pub fn target() -> TargetResult {
         options: TargetOptions {
             features: "+v6,+vfp2".to_string(),
             abi_blacklist: super::arm_base::abi_blacklist(),
+            target_mcount: "__mcount".to_string(),
             .. base
         }
     })
diff --git a/src/librustc_target/spec/armv7_unknown_cloudabi_eabihf.rs b/src/librustc_target/spec/armv7_unknown_cloudabi_eabihf.rs
index a6c7fb537c78..70d4985ab860 100644
--- a/src/librustc_target/spec/armv7_unknown_cloudabi_eabihf.rs
+++ b/src/librustc_target/spec/armv7_unknown_cloudabi_eabihf.rs
@@ -1,4 +1,4 @@
-use crate::spec::{LinkerFlavor, Target, TargetResult};
+use crate::spec::{LinkerFlavor, Target, TargetOptions, TargetResult};
 
 pub fn target() -> TargetResult {
     let mut base = super::cloudabi_base::opts();
@@ -19,6 +19,9 @@ pub fn target() -> TargetResult {
         target_env: String::new(),
         target_vendor: "unknown".to_string(),
         linker_flavor: LinkerFlavor::Gcc,
-        options: base,
+        options: TargetOptions {
+            target_mcount: "\01mcount".to_string(),
+            .. base
+        },
     })
 }
diff --git a/src/librustc_target/spec/armv7_unknown_freebsd.rs b/src/librustc_target/spec/armv7_unknown_freebsd.rs
index ba63fd2bf053..0f9ee5d44a95 100644
--- a/src/librustc_target/spec/armv7_unknown_freebsd.rs
+++ b/src/librustc_target/spec/armv7_unknown_freebsd.rs
@@ -18,6 +18,7 @@ pub fn target() -> TargetResult {
             features: "+v7,+vfp3,+d16,+thumb2,-neon".to_string(),
             max_atomic_width: Some(64),
             abi_blacklist: super::arm_base::abi_blacklist(),
+            target_mcount: "\01__gnu_mcount_nc".to_string(),
             .. base
         }
     })
diff --git a/src/librustc_target/spec/armv7_unknown_linux_gnueabihf.rs b/src/librustc_target/spec/armv7_unknown_linux_gnueabihf.rs
index f16215433c76..afba6f608ee0 100644
--- a/src/librustc_target/spec/armv7_unknown_linux_gnueabihf.rs
+++ b/src/librustc_target/spec/armv7_unknown_linux_gnueabihf.rs
@@ -23,6 +23,7 @@ pub fn target() -> TargetResult {
             cpu: "generic".to_string(),
             max_atomic_width: Some(64),
             abi_blacklist: super::arm_base::abi_blacklist(),
+            target_mcount: "\01__gnu_mcount_nc".to_string(),
             .. base
         }
     })
diff --git a/src/librustc_target/spec/armv7_unknown_linux_musleabihf.rs b/src/librustc_target/spec/armv7_unknown_linux_musleabihf.rs
index 45a26966b716..516d0401adf5 100644
--- a/src/librustc_target/spec/armv7_unknown_linux_musleabihf.rs
+++ b/src/librustc_target/spec/armv7_unknown_linux_musleabihf.rs
@@ -26,6 +26,7 @@ pub fn target() -> TargetResult {
             cpu: "generic".to_string(),
             max_atomic_width: Some(64),
             abi_blacklist: super::arm_base::abi_blacklist(),
+            target_mcount: "\01mcount".to_string(),
             .. base
         }
     })
diff --git a/src/librustc_target/spec/armv7_unknown_netbsd_eabihf.rs b/src/librustc_target/spec/armv7_unknown_netbsd_eabihf.rs
index 44e2636e9188..e2d55e9317b7 100644
--- a/src/librustc_target/spec/armv7_unknown_netbsd_eabihf.rs
+++ b/src/librustc_target/spec/armv7_unknown_netbsd_eabihf.rs
@@ -19,6 +19,7 @@ pub fn target() -> TargetResult {
             cpu: "generic".to_string(),
             max_atomic_width: Some(64),
             abi_blacklist: super::arm_base::abi_blacklist(),
+            target_mcount: "__mcount".to_string(),
             .. base
         }
     })
diff --git a/src/librustc_target/spec/i686_apple_darwin.rs b/src/librustc_target/spec/i686_apple_darwin.rs
index c8a61296d33d..a82ff33ce1db 100644
--- a/src/librustc_target/spec/i686_apple_darwin.rs
+++ b/src/librustc_target/spec/i686_apple_darwin.rs
@@ -1,4 +1,4 @@
-use crate::spec::{LinkerFlavor, Target, TargetResult};
+use crate::spec::{LinkerFlavor, Target, TargetOptions, TargetResult};
 
 pub fn target() -> TargetResult {
     let mut base = super::apple_base::opts();
@@ -19,6 +19,9 @@ pub fn target() -> TargetResult {
         target_env: String::new(),
         target_vendor: "apple".to_string(),
         linker_flavor: LinkerFlavor::Gcc,
-        options: base,
+        options: TargetOptions {
+            target_mcount: "\01mcount".to_string(),
+            .. base
+        },
     })
 }
diff --git a/src/librustc_target/spec/i686_unknown_netbsd.rs b/src/librustc_target/spec/i686_unknown_netbsd.rs
index e8a9f29ea5f4..99130e93dad6 100644
--- a/src/librustc_target/spec/i686_unknown_netbsd.rs
+++ b/src/librustc_target/spec/i686_unknown_netbsd.rs
@@ -1,4 +1,4 @@
-use crate::spec::{LinkerFlavor, Target, TargetResult};
+use crate::spec::{LinkerFlavor, Target, TargetOptions, TargetResult};
 
 pub fn target() -> TargetResult {
     let mut base = super::netbsd_base::opts();
@@ -18,6 +18,9 @@ pub fn target() -> TargetResult {
         target_env: String::new(),
         target_vendor: "unknown".to_string(),
         linker_flavor: LinkerFlavor::Gcc,
-        options: base,
+        options: TargetOptions {
+            target_mcount: "__mcount".to_string(),
+            .. base
+        },
     })
 }
diff --git a/src/librustc_target/spec/mips64_unknown_linux_gnuabi64.rs b/src/librustc_target/spec/mips64_unknown_linux_gnuabi64.rs
index 3b38e64050f3..b2ea8a6f3881 100644
--- a/src/librustc_target/spec/mips64_unknown_linux_gnuabi64.rs
+++ b/src/librustc_target/spec/mips64_unknown_linux_gnuabi64.rs
@@ -17,6 +17,7 @@ pub fn target() -> TargetResult {
             cpu: "mips64r2".to_string(),
             features: "+mips64r2".to_string(),
             max_atomic_width: Some(64),
+            target_mcount: "_mcount".to_string(),
 
             ..super::linux_base::opts()
         },
diff --git a/src/librustc_target/spec/mips64el_unknown_linux_gnuabi64.rs b/src/librustc_target/spec/mips64el_unknown_linux_gnuabi64.rs
index 0f6cd86d616d..48aea4a39b0a 100644
--- a/src/librustc_target/spec/mips64el_unknown_linux_gnuabi64.rs
+++ b/src/librustc_target/spec/mips64el_unknown_linux_gnuabi64.rs
@@ -17,6 +17,7 @@ pub fn target() -> TargetResult {
             cpu: "mips64r2".to_string(),
             features: "+mips64r2".to_string(),
             max_atomic_width: Some(64),
+            target_mcount: "_mcount".to_string(),
 
             ..super::linux_base::opts()
         },
diff --git a/src/librustc_target/spec/mips_unknown_linux_gnu.rs b/src/librustc_target/spec/mips_unknown_linux_gnu.rs
index b4d29c5fbeaf..e360abdb38d3 100644
--- a/src/librustc_target/spec/mips_unknown_linux_gnu.rs
+++ b/src/librustc_target/spec/mips_unknown_linux_gnu.rs
@@ -16,6 +16,7 @@ pub fn target() -> TargetResult {
             cpu: "mips32r2".to_string(),
             features: "+mips32r2,+fpxx,+nooddspreg".to_string(),
             max_atomic_width: Some(32),
+            target_mcount: "_mcount".to_string(),
 
             ..super::linux_base::opts()
         },
diff --git a/src/librustc_target/spec/mips_unknown_linux_musl.rs b/src/librustc_target/spec/mips_unknown_linux_musl.rs
index c56c6e382295..3f5428de9507 100644
--- a/src/librustc_target/spec/mips_unknown_linux_musl.rs
+++ b/src/librustc_target/spec/mips_unknown_linux_musl.rs
@@ -1,4 +1,4 @@
-use crate::spec::{LinkerFlavor, Target, TargetResult};
+use crate::spec::{LinkerFlavor, Target, TargetOptions, TargetResult};
 
 pub fn target() -> TargetResult {
     let mut base = super::linux_musl_base::opts();
@@ -17,6 +17,9 @@ pub fn target() -> TargetResult {
         target_env: "musl".to_string(),
         target_vendor: "unknown".to_string(),
         linker_flavor: LinkerFlavor::Gcc,
-        options: base,
+        options: TargetOptions {
+            target_mcount: "_mcount".to_string(),
+            .. base
+        },
     })
 }
diff --git a/src/librustc_target/spec/mips_unknown_linux_uclibc.rs b/src/librustc_target/spec/mips_unknown_linux_uclibc.rs
index cb02769c7dfe..8116b8c9cc84 100644
--- a/src/librustc_target/spec/mips_unknown_linux_uclibc.rs
+++ b/src/librustc_target/spec/mips_unknown_linux_uclibc.rs
@@ -16,6 +16,7 @@ pub fn target() -> TargetResult {
             cpu: "mips32r2".to_string(),
             features: "+mips32r2,+soft-float".to_string(),
             max_atomic_width: Some(32),
+            target_mcount: "_mcount".to_string(),
 
             ..super::linux_base::opts()
         },
diff --git a/src/librustc_target/spec/mipsel_unknown_linux_gnu.rs b/src/librustc_target/spec/mipsel_unknown_linux_gnu.rs
index ed49ddd49937..7e9d8cd942a2 100644
--- a/src/librustc_target/spec/mipsel_unknown_linux_gnu.rs
+++ b/src/librustc_target/spec/mipsel_unknown_linux_gnu.rs
@@ -17,6 +17,7 @@ pub fn target() -> TargetResult {
             cpu: "mips32r2".to_string(),
             features: "+mips32r2,+fpxx,+nooddspreg".to_string(),
             max_atomic_width: Some(32),
+            target_mcount: "_mcount".to_string(),
 
             ..super::linux_base::opts()
         },
diff --git a/src/librustc_target/spec/mipsel_unknown_linux_musl.rs b/src/librustc_target/spec/mipsel_unknown_linux_musl.rs
index bcc49cf5ffe4..56ad2940feba 100644
--- a/src/librustc_target/spec/mipsel_unknown_linux_musl.rs
+++ b/src/librustc_target/spec/mipsel_unknown_linux_musl.rs
@@ -1,4 +1,4 @@
-use crate::spec::{LinkerFlavor, Target, TargetResult};
+use crate::spec::{LinkerFlavor, Target, TargetOptions, TargetResult};
 
 pub fn target() -> TargetResult {
     let mut base = super::linux_musl_base::opts();
@@ -17,6 +17,9 @@ pub fn target() -> TargetResult {
         target_env: "musl".to_string(),
         target_vendor: "unknown".to_string(),
         linker_flavor: LinkerFlavor::Gcc,
-        options: base,
+        options: TargetOptions {
+            target_mcount: "_mcount".to_string(),
+            .. base
+        },
     })
 }
diff --git a/src/librustc_target/spec/mipsel_unknown_linux_uclibc.rs b/src/librustc_target/spec/mipsel_unknown_linux_uclibc.rs
index 205f328a24ce..a8152011efa7 100644
--- a/src/librustc_target/spec/mipsel_unknown_linux_uclibc.rs
+++ b/src/librustc_target/spec/mipsel_unknown_linux_uclibc.rs
@@ -17,6 +17,7 @@ pub fn target() -> TargetResult {
             cpu: "mips32r2".to_string(),
             features: "+mips32r2,+soft-float".to_string(),
             max_atomic_width: Some(32),
+            target_mcount: "_mcount".to_string(),
 
             ..super::linux_base::opts()
         },
diff --git a/src/librustc_target/spec/mipsisa32r6_unknown_linux_gnu.rs b/src/librustc_target/spec/mipsisa32r6_unknown_linux_gnu.rs
index f47291458492..36b83c63fca2 100644
--- a/src/librustc_target/spec/mipsisa32r6_unknown_linux_gnu.rs
+++ b/src/librustc_target/spec/mipsisa32r6_unknown_linux_gnu.rs
@@ -16,6 +16,7 @@ pub fn target() -> TargetResult {
             cpu: "mips32r6".to_string(),
             features: "+mips32r6".to_string(),
             max_atomic_width: Some(32),
+            target_mcount: "_mcount".to_string(),
 
             ..super::linux_base::opts()
         },
diff --git a/src/librustc_target/spec/mipsisa32r6el_unknown_linux_gnu.rs b/src/librustc_target/spec/mipsisa32r6el_unknown_linux_gnu.rs
index f4f98d33571f..717ae3f1d20e 100644
--- a/src/librustc_target/spec/mipsisa32r6el_unknown_linux_gnu.rs
+++ b/src/librustc_target/spec/mipsisa32r6el_unknown_linux_gnu.rs
@@ -17,6 +17,7 @@ pub fn target() -> TargetResult {
             cpu: "mips32r6".to_string(),
             features: "+mips32r6".to_string(),
             max_atomic_width: Some(32),
+            target_mcount: "_mcount".to_string(),
 
             ..super::linux_base::opts()
         },
diff --git a/src/librustc_target/spec/mipsisa64r6_unknown_linux_gnuabi64.rs b/src/librustc_target/spec/mipsisa64r6_unknown_linux_gnuabi64.rs
index 7faed3adc79c..3f7d233e55fb 100644
--- a/src/librustc_target/spec/mipsisa64r6_unknown_linux_gnuabi64.rs
+++ b/src/librustc_target/spec/mipsisa64r6_unknown_linux_gnuabi64.rs
@@ -17,6 +17,7 @@ pub fn target() -> TargetResult {
             cpu: "mips64r6".to_string(),
             features: "+mips64r6".to_string(),
             max_atomic_width: Some(64),
+            target_mcount: "_mcount".to_string(),
 
             ..super::linux_base::opts()
         },
diff --git a/src/librustc_target/spec/mipsisa64r6el_unknown_linux_gnuabi64.rs b/src/librustc_target/spec/mipsisa64r6el_unknown_linux_gnuabi64.rs
index 58a814a759eb..4f41b8323a99 100644
--- a/src/librustc_target/spec/mipsisa64r6el_unknown_linux_gnuabi64.rs
+++ b/src/librustc_target/spec/mipsisa64r6el_unknown_linux_gnuabi64.rs
@@ -17,6 +17,7 @@ pub fn target() -> TargetResult {
             cpu: "mips64r6".to_string(),
             features: "+mips64r6".to_string(),
             max_atomic_width: Some(64),
+            target_mcount: "_mcount".to_string(),
 
             ..super::linux_base::opts()
         },
diff --git a/src/librustc_target/spec/mod.rs b/src/librustc_target/spec/mod.rs
index fdb1db645c3c..7654d3932e33 100644
--- a/src/librustc_target/spec/mod.rs
+++ b/src/librustc_target/spec/mod.rs
@@ -759,7 +759,10 @@ pub struct TargetOptions {
     /// to opt out. The default is "aliases".
     ///
     /// Workaround for: https://github.com/rust-lang/rust/issues/57356
-    pub merge_functions: MergeFunctions
+    pub merge_functions: MergeFunctions,
+
+    /// Use platform dependent mcount function
+    pub target_mcount: String
 }
 
 impl Default for TargetOptions {
@@ -843,6 +846,7 @@ impl Default for TargetOptions {
             simd_types_indirect: true,
             override_export_symbols: None,
             merge_functions: MergeFunctions::Aliases,
+            target_mcount: "mcount".to_string(),
         }
     }
 }
@@ -1148,6 +1152,7 @@ impl Target {
         key!(simd_types_indirect, bool);
         key!(override_export_symbols, opt_list);
         key!(merge_functions, MergeFunctions)?;
+        key!(target_mcount);
 
         if let Some(array) = obj.find("abi-blacklist").and_then(Json::as_array) {
             for name in array.iter().filter_map(|abi| abi.as_string()) {
@@ -1362,6 +1367,7 @@ impl ToJson for Target {
         target_option_val!(simd_types_indirect);
         target_option_val!(override_export_symbols);
         target_option_val!(merge_functions);
+        target_option_val!(target_mcount);
 
         if default.abi_blacklist != self.options.abi_blacklist {
             d.insert("abi-blacklist".to_string(), self.options.abi_blacklist.iter()
diff --git a/src/librustc_target/spec/powerpc64_unknown_freebsd.rs b/src/librustc_target/spec/powerpc64_unknown_freebsd.rs
index 360876b9ff55..fc881db6b090 100644
--- a/src/librustc_target/spec/powerpc64_unknown_freebsd.rs
+++ b/src/librustc_target/spec/powerpc64_unknown_freebsd.rs
@@ -1,4 +1,4 @@
-use crate::spec::{LinkerFlavor, Target, TargetResult};
+use crate::spec::{LinkerFlavor, Target, TargetOptions, TargetResult};
 
 pub fn target() -> TargetResult {
     let mut base = super::freebsd_base::opts();
@@ -17,6 +17,9 @@ pub fn target() -> TargetResult {
         target_env: String::new(),
         target_vendor: "unknown".to_string(),
         linker_flavor: LinkerFlavor::Gcc,
-        options: base,
+        options: TargetOptions {
+            target_mcount: "_mcount".to_string(),
+            .. base
+        },
     })
 }
diff --git a/src/librustc_target/spec/powerpc64_unknown_linux_gnu.rs b/src/librustc_target/spec/powerpc64_unknown_linux_gnu.rs
index c16db7583f32..89e68ab30620 100644
--- a/src/librustc_target/spec/powerpc64_unknown_linux_gnu.rs
+++ b/src/librustc_target/spec/powerpc64_unknown_linux_gnu.rs
@@ -1,4 +1,4 @@
-use crate::spec::{LinkerFlavor, Target, TargetResult, RelroLevel};
+use crate::spec::{LinkerFlavor, Target, TargetOptions, TargetResult, RelroLevel};
 
 pub fn target() -> TargetResult {
     let mut base = super::linux_base::opts();
@@ -21,6 +21,9 @@ pub fn target() -> TargetResult {
         target_env: "gnu".to_string(),
         target_vendor: "unknown".to_string(),
         linker_flavor: LinkerFlavor::Gcc,
-        options: base,
+        options: TargetOptions {
+            target_mcount: "_mcount".to_string(),
+            .. base
+        },
     })
 }
diff --git a/src/librustc_target/spec/powerpc64_unknown_linux_musl.rs b/src/librustc_target/spec/powerpc64_unknown_linux_musl.rs
index ac0b7431f91a..be91dc44b935 100644
--- a/src/librustc_target/spec/powerpc64_unknown_linux_musl.rs
+++ b/src/librustc_target/spec/powerpc64_unknown_linux_musl.rs
@@ -1,4 +1,4 @@
-use crate::spec::{LinkerFlavor, Target, TargetResult};
+use crate::spec::{LinkerFlavor, Target, TargetOptions, TargetResult};
 
 pub fn target() -> TargetResult {
     let mut base = super::linux_musl_base::opts();
@@ -17,6 +17,9 @@ pub fn target() -> TargetResult {
         target_env: "musl".to_string(),
         target_vendor: "unknown".to_string(),
         linker_flavor: LinkerFlavor::Gcc,
-        options: base,
+        options: TargetOptions {
+            target_mcount: "_mcount".to_string(),
+            .. base
+        },
     })
 }
diff --git a/src/librustc_target/spec/powerpc64le_unknown_linux_gnu.rs b/src/librustc_target/spec/powerpc64le_unknown_linux_gnu.rs
index 038b925a2869..784e3b090943 100644
--- a/src/librustc_target/spec/powerpc64le_unknown_linux_gnu.rs
+++ b/src/librustc_target/spec/powerpc64le_unknown_linux_gnu.rs
@@ -1,4 +1,4 @@
-use crate::spec::{LinkerFlavor, Target, TargetResult};
+use crate::spec::{LinkerFlavor, Target, TargetOptions, TargetResult};
 
 pub fn target() -> TargetResult {
     let mut base = super::linux_base::opts();
@@ -17,6 +17,9 @@ pub fn target() -> TargetResult {
         target_env: "gnu".to_string(),
         target_vendor: "unknown".to_string(),
         linker_flavor: LinkerFlavor::Gcc,
-        options: base,
+        options: TargetOptions {
+            target_mcount: "_mcount".to_string(),
+            .. base
+        },
     })
 }
diff --git a/src/librustc_target/spec/powerpc64le_unknown_linux_musl.rs b/src/librustc_target/spec/powerpc64le_unknown_linux_musl.rs
index 57103345f0a0..a3cf47fc5e08 100644
--- a/src/librustc_target/spec/powerpc64le_unknown_linux_musl.rs
+++ b/src/librustc_target/spec/powerpc64le_unknown_linux_musl.rs
@@ -1,4 +1,4 @@
-use crate::spec::{LinkerFlavor, Target, TargetResult};
+use crate::spec::{LinkerFlavor, Target, TargetOptions, TargetResult};
 
 pub fn target() -> TargetResult {
     let mut base = super::linux_musl_base::opts();
@@ -17,6 +17,9 @@ pub fn target() -> TargetResult {
         target_env: "musl".to_string(),
         target_vendor: "unknown".to_string(),
         linker_flavor: LinkerFlavor::Gcc,
-        options: base,
+        options: TargetOptions {
+            target_mcount: "_mcount".to_string(),
+            .. base
+        },
     })
 }
diff --git a/src/librustc_target/spec/powerpc_unknown_linux_gnu.rs b/src/librustc_target/spec/powerpc_unknown_linux_gnu.rs
index 38a801d5ab50..ff52fbc179b1 100644
--- a/src/librustc_target/spec/powerpc_unknown_linux_gnu.rs
+++ b/src/librustc_target/spec/powerpc_unknown_linux_gnu.rs
@@ -1,4 +1,4 @@
-use crate::spec::{LinkerFlavor, Target, TargetResult};
+use crate::spec::{LinkerFlavor, Target, TargetOptions, TargetResult};
 
 pub fn target() -> TargetResult {
     let mut base = super::linux_base::opts();
@@ -16,6 +16,9 @@ pub fn target() -> TargetResult {
         target_env: "gnu".to_string(),
         target_vendor: "unknown".to_string(),
         linker_flavor: LinkerFlavor::Gcc,
-        options: base,
+        options: TargetOptions {
+            target_mcount: "_mcount".to_string(),
+            .. base
+        },
     })
 }
diff --git a/src/librustc_target/spec/powerpc_unknown_linux_gnuspe.rs b/src/librustc_target/spec/powerpc_unknown_linux_gnuspe.rs
index 675b2c749d64..1868c42be39d 100644
--- a/src/librustc_target/spec/powerpc_unknown_linux_gnuspe.rs
+++ b/src/librustc_target/spec/powerpc_unknown_linux_gnuspe.rs
@@ -1,4 +1,4 @@
-use crate::spec::{LinkerFlavor, Target, TargetResult};
+use crate::spec::{LinkerFlavor, Target, TargetOptions, TargetResult};
 
 pub fn target() -> TargetResult {
     let mut base = super::linux_base::opts();
@@ -16,6 +16,9 @@ pub fn target() -> TargetResult {
         target_env: "gnu".to_string(),
         target_vendor: "unknown".to_string(),
         linker_flavor: LinkerFlavor::Gcc,
-        options: base,
+        options: TargetOptions {
+            target_mcount: "_mcount".to_string(),
+            .. base
+        },
     })
 }
diff --git a/src/librustc_target/spec/powerpc_unknown_linux_musl.rs b/src/librustc_target/spec/powerpc_unknown_linux_musl.rs
index 240443aa98db..1ad2201092c3 100644
--- a/src/librustc_target/spec/powerpc_unknown_linux_musl.rs
+++ b/src/librustc_target/spec/powerpc_unknown_linux_musl.rs
@@ -1,4 +1,4 @@
-use crate::spec::{LinkerFlavor, Target, TargetResult};
+use crate::spec::{LinkerFlavor, Target, TargetOptions, TargetResult};
 
 pub fn target() -> TargetResult {
     let mut base = super::linux_musl_base::opts();
@@ -16,6 +16,9 @@ pub fn target() -> TargetResult {
         target_env: "musl".to_string(),
         target_vendor: "unknown".to_string(),
         linker_flavor: LinkerFlavor::Gcc,
-        options: base,
+        options: TargetOptions {
+            target_mcount: "_mcount".to_string(),
+            .. base
+        },
     })
 }
diff --git a/src/librustc_target/spec/powerpc_unknown_netbsd.rs b/src/librustc_target/spec/powerpc_unknown_netbsd.rs
index 10e7089cf1c4..6cc3a6c2ef3f 100644
--- a/src/librustc_target/spec/powerpc_unknown_netbsd.rs
+++ b/src/librustc_target/spec/powerpc_unknown_netbsd.rs
@@ -1,4 +1,4 @@
-use crate::spec::{LinkerFlavor, Target, TargetResult};
+use crate::spec::{LinkerFlavor, Target, TargetOptions, TargetResult};
 
 pub fn target() -> TargetResult {
     let mut base = super::netbsd_base::opts();
@@ -16,6 +16,9 @@ pub fn target() -> TargetResult {
         target_env: String::new(),
         target_vendor: "unknown".to_string(),
         linker_flavor: LinkerFlavor::Gcc,
-        options: base,
+        options: TargetOptions {
+            target_mcount: "__mcount".to_string(),
+            .. base
+        },
     })
 }
diff --git a/src/librustc_target/spec/sparc64_unknown_netbsd.rs b/src/librustc_target/spec/sparc64_unknown_netbsd.rs
index 78d53e69e8b5..09d1debef41e 100644
--- a/src/librustc_target/spec/sparc64_unknown_netbsd.rs
+++ b/src/librustc_target/spec/sparc64_unknown_netbsd.rs
@@ -1,4 +1,4 @@
-use crate::spec::{LinkerFlavor, Target, TargetResult};
+use crate::spec::{LinkerFlavor, Target, TargetOptions, TargetResult};
 
 pub fn target() -> TargetResult {
     let mut base = super::netbsd_base::opts();
@@ -17,6 +17,9 @@ pub fn target() -> TargetResult {
         target_env: String::new(),
         target_vendor: "unknown".to_string(),
         linker_flavor: LinkerFlavor::Gcc,
-        options: base,
+        options: TargetOptions {
+            target_mcount: "__mcount".to_string(),
+            .. base
+        },
     })
 }
diff --git a/src/librustc_target/spec/x86_64_apple_darwin.rs b/src/librustc_target/spec/x86_64_apple_darwin.rs
index 0911ce06c13d..fecc20c01c5e 100644
--- a/src/librustc_target/spec/x86_64_apple_darwin.rs
+++ b/src/librustc_target/spec/x86_64_apple_darwin.rs
@@ -1,4 +1,4 @@
-use crate::spec::{LinkerFlavor, Target, TargetResult};
+use crate::spec::{LinkerFlavor, Target, TargetOptions, TargetResult};
 
 pub fn target() -> TargetResult {
     let mut base = super::apple_base::opts();
@@ -19,6 +19,9 @@ pub fn target() -> TargetResult {
         target_env: String::new(),
         target_vendor: "apple".to_string(),
         linker_flavor: LinkerFlavor::Gcc,
-        options: base,
+        options: TargetOptions {
+            target_mcount: "\01mcount".to_string(),
+            .. base
+        },
     })
 }
diff --git a/src/librustc_target/spec/x86_64_rumprun_netbsd.rs b/src/librustc_target/spec/x86_64_rumprun_netbsd.rs
index a2c706c4c723..f6861f2a6872 100644
--- a/src/librustc_target/spec/x86_64_rumprun_netbsd.rs
+++ b/src/librustc_target/spec/x86_64_rumprun_netbsd.rs
@@ -1,4 +1,4 @@
-use crate::spec::{LinkerFlavor, Target, TargetResult};
+use crate::spec::{LinkerFlavor, Target, TargetOptions, TargetResult};
 
 pub fn target() -> TargetResult {
     let mut base = super::netbsd_base::opts();
@@ -24,6 +24,9 @@ pub fn target() -> TargetResult {
         target_env: String::new(),
         target_vendor: "rumprun".to_string(),
         linker_flavor: LinkerFlavor::Gcc,
-        options: base,
+        options: TargetOptions {
+            target_mcount: "__mcount".to_string(),
+            .. base
+        },
     })
 }
diff --git a/src/librustc_target/spec/x86_64_unknown_netbsd.rs b/src/librustc_target/spec/x86_64_unknown_netbsd.rs
index ffc4f1d5c49b..6f4ab4995b5d 100644
--- a/src/librustc_target/spec/x86_64_unknown_netbsd.rs
+++ b/src/librustc_target/spec/x86_64_unknown_netbsd.rs
@@ -1,4 +1,4 @@
-use crate::spec::{LinkerFlavor, Target, TargetResult};
+use crate::spec::{LinkerFlavor, Target, TargetOptions, TargetResult};
 
 pub fn target() -> TargetResult {
     let mut base = super::netbsd_base::opts();
@@ -18,6 +18,9 @@ pub fn target() -> TargetResult {
         target_env: String::new(),
         target_vendor: "unknown".to_string(),
         linker_flavor: LinkerFlavor::Gcc,
-        options: base,
+        options: TargetOptions {
+            target_mcount: "__mcount".to_string(),
+            .. base
+        },
     })
 }

From 3281248b88262687fcf34b2404cece968bcf837c Mon Sep 17 00:00:00 2001
From: Yuki OKUSHI <huyuumi.dev@gmail.com>
Date: Sat, 30 Mar 2019 18:50:34 +0900
Subject: [PATCH 04/30] Use target_mcount

---
 src/librustc_codegen_llvm/attributes.rs | 28 ++++---------------------
 1 file changed, 4 insertions(+), 24 deletions(-)

diff --git a/src/librustc_codegen_llvm/attributes.rs b/src/librustc_codegen_llvm/attributes.rs
index e765b986d623..9aaad60cd6d3 100644
--- a/src/librustc_codegen_llvm/attributes.rs
+++ b/src/librustc_codegen_llvm/attributes.rs
@@ -80,30 +80,10 @@ pub fn set_instrument_function(cx: &CodegenCx<'ll, '_>, llfn: &'ll Value) {
 
         // The function name varies on platforms.
         // See test/CodeGen/mcount.c in clang.
-        let mcount_name = if cfg!(target_os = "netbsd") {
-            const_cstr!("__mcount")
-        } else if cfg!(any(
-                target_arch = "mips", target_arch = "mips64",
-                target_arch = "powerpc", target_arch = "powerpc64")) {
-            const_cstr!("_mcount")
-        } else if cfg!(target_os = "darwin") {
-            const_cstr!("\01mcount")
-        } else if cfg!(target_arch = "aarch64")
-            && (cfg!(target_os = "linux")
-                || (cfg!(target_os = "unknown") && cfg!(target_env = "gnu")))
-        {
-            const_cstr!("\01_mcount")
-        } else if cfg!(target_arch = "arm")
-            && cfg!(any(target_os = "linux", target_os = "unknown"))
-        {
-            if cfg!(target_env = "gnu") {
-                const_cstr!("\01__gnu_mcount_nc")
-            } else {
-                const_cstr!("\01mcount")
-            }
-        } else {
-            const_cstr!("mcount")
-        };
+        use std::ffi::CStr;
+        let target_mcount = format!("{}{}",
+            &cx.sess().target.target.options.target_mcount, "\0");
+        let mcount_name = CStr::from_bytes_with_nul(target_mcount.as_bytes()).unwrap();
 
         llvm::AddFunctionAttrStringValue(
             llfn, llvm::AttributePlace::Function,

From 77774e4e960e6b65ddb95b087772c6d2ad6c3009 Mon Sep 17 00:00:00 2001
From: Yuki OKUSHI <huyuumi.dev@gmail.com>
Date: Sat, 30 Mar 2019 21:37:02 +0900
Subject: [PATCH 05/30] Use CString

---
 src/librustc_codegen_llvm/attributes.rs | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/src/librustc_codegen_llvm/attributes.rs b/src/librustc_codegen_llvm/attributes.rs
index 9aaad60cd6d3..77fa34e74dd7 100644
--- a/src/librustc_codegen_llvm/attributes.rs
+++ b/src/librustc_codegen_llvm/attributes.rs
@@ -80,14 +80,12 @@ pub fn set_instrument_function(cx: &CodegenCx<'ll, '_>, llfn: &'ll Value) {
 
         // The function name varies on platforms.
         // See test/CodeGen/mcount.c in clang.
-        use std::ffi::CStr;
-        let target_mcount = format!("{}{}",
-            &cx.sess().target.target.options.target_mcount, "\0");
-        let mcount_name = CStr::from_bytes_with_nul(target_mcount.as_bytes()).unwrap();
+        let mcount_name = CString::new(
+            cx.sess().target.target.options.target_mcount.as_str().as_bytes()).unwrap();
 
         llvm::AddFunctionAttrStringValue(
             llfn, llvm::AttributePlace::Function,
-            const_cstr!("instrument-function-entry-inlined"), mcount_name);
+            const_cstr!("instrument-function-entry-inlined"), &mcount_name);
     }
 }
 

From 29d68edc6e1d4f5e6d1599202e3af38080840977 Mon Sep 17 00:00:00 2001
From: Fabian Drinck <fabian.drinck@rwth-aachen.de>
Date: Fri, 22 Feb 2019 15:07:18 +0100
Subject: [PATCH 06/30] Add lint for redundant imports

Co-authored-by: Stephan Schauerte <stephan.schauerte@gmail.com>
---
 src/librustc/lint/builtin.rs            |  6 ++
 src/librustc_resolve/resolve_imports.rs | 93 ++++++++++++++++++++++++-
 src/test/ui/lint/use-redundant.rs       | 17 +++++
 src/test/ui/lint/use-redundant.stderr   | 14 ++++
 4 files changed, 129 insertions(+), 1 deletion(-)
 create mode 100644 src/test/ui/lint/use-redundant.rs
 create mode 100644 src/test/ui/lint/use-redundant.stderr

diff --git a/src/librustc/lint/builtin.rs b/src/librustc/lint/builtin.rs
index 10a5c1479fa6..615bc0af37a1 100644
--- a/src/librustc/lint/builtin.rs
+++ b/src/librustc/lint/builtin.rs
@@ -392,6 +392,12 @@ declare_lint! {
     "nested occurrence of `impl Trait` type"
 }
 
+declare_lint! {
+    pub REDUNDANT_IMPORT,
+    Warn,
+    "redundant import"
+}
+
 /// Does nothing as a lint pass, but registers some `Lint`s
 /// that are used by other parts of the compiler.
 #[derive(Copy, Clone)]
diff --git a/src/librustc_resolve/resolve_imports.rs b/src/librustc_resolve/resolve_imports.rs
index c2d2bd753c82..b40b68b08534 100644
--- a/src/librustc_resolve/resolve_imports.rs
+++ b/src/librustc_resolve/resolve_imports.rs
@@ -7,6 +7,7 @@ use crate::{NameBinding, NameBindingKind, ToNameBinding, PathResult, PrivacyErro
 use crate::{Resolver, Segment};
 use crate::{names_to_string, module_to_string};
 use crate::{resolve_error, ResolutionError, Suggestion};
+use crate::ModuleKind;
 use crate::macros::ParentScope;
 
 use errors::Applicability;
@@ -14,7 +15,11 @@ use errors::Applicability;
 use rustc_data_structures::ptr_key::PtrKey;
 use rustc::ty;
 use rustc::lint::builtin::BuiltinLintDiagnostics;
-use rustc::lint::builtin::{DUPLICATE_MACRO_EXPORTS, PUB_USE_OF_PRIVATE_EXTERN_CRATE};
+use rustc::lint::builtin::{
+    DUPLICATE_MACRO_EXPORTS,
+    PUB_USE_OF_PRIVATE_EXTERN_CRATE,
+    REDUNDANT_IMPORT,
+};
 use rustc::hir::def_id::{CrateNum, DefId};
 use rustc::hir::def::*;
 use rustc::session::DiagnosticMessageId;
@@ -1227,10 +1232,96 @@ impl<'a, 'b:'a> ImportResolver<'a, 'b> {
             import[ns] = Some(PathResolution::new(def));
         });
 
+        self.check_for_redundant_imports(
+            ident,
+            directive,
+            source_bindings,
+            target_bindings,
+            target,
+        );
+
         debug!("(resolving single import) successfully resolved import");
         None
     }
 
+    fn check_for_redundant_imports(
+        &mut self,
+        ident: Ident,
+        directive: &'b ImportDirective<'b>,
+        source_bindings: &PerNS<Cell<Result<&'b NameBinding<'b>, Determinacy>>>,
+        target_bindings: &PerNS<Cell<Option<&'b NameBinding<'b>>>>,
+        target: Ident,
+    ) {
+        // Check if we are at the root of a macro expansion and skip if we are.
+        if directive.parent_scope.expansion != Mark::root() {
+            return;
+        }
+
+        if let ModuleKind::Def(_, _) = directive.parent_scope.module.kind {
+            return;
+        }
+
+        let mut is_redundant = PerNS {
+            value_ns: None,
+            type_ns: None,
+            macro_ns: None,
+        };
+
+        let mut redundant_span = PerNS {
+            value_ns: None,
+            type_ns: None,
+            macro_ns: None,
+        };
+
+        self.per_ns(|this, ns| if let Some(binding) = source_bindings[ns].get().ok() {
+            if binding.def() == Def::Err {
+                return;
+            }
+
+            let orig_blacklisted_binding = mem::replace(
+                &mut this.blacklisted_binding,
+                target_bindings[ns].get()
+            );
+
+            match this.early_resolve_ident_in_lexical_scope(
+                target,
+                ScopeSet::Import(ns),
+                &directive.parent_scope,
+                false,
+                false,
+                directive.span,
+            ) {
+                Ok(other_binding) => {
+                    is_redundant[ns] = Some(binding.def() == other_binding.def());
+                    redundant_span[ns] = Some(other_binding.span);
+                }
+                Err(_) => is_redundant[ns] = Some(false)
+            }
+
+            this.blacklisted_binding = orig_blacklisted_binding;
+        });
+
+        if !is_redundant.is_empty() &&
+            is_redundant.present_items().all(|is_redundant| is_redundant)
+        {
+            self.session.buffer_lint(
+                REDUNDANT_IMPORT,
+                directive.id,
+                directive.span,
+                &format!("the item `{}` is imported redundantly", ident),
+            );
+
+            for span in redundant_span.present_items() {
+                self.session.buffer_lint(
+                    REDUNDANT_IMPORT,
+                    directive.id,
+                    span,
+                    "another import"
+                );
+            }
+        }
+    }
+
     fn resolve_glob_import(&mut self, directive: &'b ImportDirective<'b>) {
         let module = match directive.imported_module.get().unwrap() {
             ModuleOrUniformRoot::Module(module) => module,
diff --git a/src/test/ui/lint/use-redundant.rs b/src/test/ui/lint/use-redundant.rs
new file mode 100644
index 000000000000..50d4d30625a6
--- /dev/null
+++ b/src/test/ui/lint/use-redundant.rs
@@ -0,0 +1,17 @@
+// compile-pass
+
+use crate::foo::Bar; //~ WARNING first import
+
+mod foo {
+    pub type Bar = i32;
+}
+
+fn baz() -> Bar {
+    3
+}
+
+fn main() {
+    use crate::foo::Bar; //~ WARNING redundant import
+    let _a: Bar = 3;
+    baz();
+}
diff --git a/src/test/ui/lint/use-redundant.stderr b/src/test/ui/lint/use-redundant.stderr
new file mode 100644
index 000000000000..6a6becc5e615
--- /dev/null
+++ b/src/test/ui/lint/use-redundant.stderr
@@ -0,0 +1,14 @@
+warning: the item `Bar` is imported redundantly
+  --> $DIR/use-redundant.rs:14:9
+   |
+LL |     use crate::foo::Bar; //~ WARNING redundant import
+   |         ^^^^^^^^^^^^^^^
+   |
+   = note: #[warn(redundant_import)] on by default
+
+warning: another import
+  --> $DIR/use-redundant.rs:3:5
+   |
+LL | use crate::foo::Bar; //~ WARNING first import
+   |     ^^^^^^^^^^^^^^^
+

From 541c4999a9e878f26ada62bc9a82f088a8f2fad2 Mon Sep 17 00:00:00 2001
From: Fabian Drinck <fabian.drinck@rwth-aachen.de>
Date: Sun, 10 Mar 2019 12:52:30 +0100
Subject: [PATCH 07/30] Remove redundant imports

---
 src/librustc/ty/query/on_disk_cache.rs      | 1 -
 src/librustc_codegen_llvm/context.rs        | 1 -
 src/librustc_codegen_ssa/mir/rvalue.rs      | 1 -
 src/librustc_errors/lib.rs                  | 2 +-
 src/librustc_interface/profile/mod.rs       | 1 -
 src/librustc_mir/hair/pattern/mod.rs        | 1 -
 src/librustc_mir/interpret/operator.rs      | 2 --
 src/librustc_resolve/lib.rs                 | 1 -
 src/librustc_traits/lowering/environment.rs | 2 +-
 src/librustc_typeck/check/wfcheck.rs        | 5 -----
 10 files changed, 2 insertions(+), 15 deletions(-)

diff --git a/src/librustc/ty/query/on_disk_cache.rs b/src/librustc/ty/query/on_disk_cache.rs
index 1b4c36b8b06c..05d80f9203f1 100644
--- a/src/librustc/ty/query/on_disk_cache.rs
+++ b/src/librustc/ty/query/on_disk_cache.rs
@@ -777,7 +777,6 @@ impl<'enc, 'a, 'tcx, E> CacheEncoder<'enc, 'a, 'tcx, E>
                                                  value: &V)
                                                  -> Result<(), E::Error>
     {
-        use crate::ty::codec::TyEncoder;
         let start_pos = self.position();
 
         tag.encode(self)?;
diff --git a/src/librustc_codegen_llvm/context.rs b/src/librustc_codegen_llvm/context.rs
index fc79e868fb4b..f6956bd5736e 100644
--- a/src/librustc_codegen_llvm/context.rs
+++ b/src/librustc_codegen_llvm/context.rs
@@ -372,7 +372,6 @@ impl MiscMethods<'tcx> for CodegenCx<'ll, 'tcx> {
     // Returns a Value of the "eh_unwind_resume" lang item if one is defined,
     // otherwise declares it as an external function.
     fn eh_unwind_resume(&self) -> &'ll Value {
-        use crate::attributes;
         let unwresume = &self.eh_unwind_resume;
         if let Some(llfn) = unwresume.get() {
             return llfn;
diff --git a/src/librustc_codegen_ssa/mir/rvalue.rs b/src/librustc_codegen_ssa/mir/rvalue.rs
index 7a31c5b3950e..fc4f6b832478 100644
--- a/src/librustc_codegen_ssa/mir/rvalue.rs
+++ b/src/librustc_codegen_ssa/mir/rvalue.rs
@@ -732,7 +732,6 @@ fn cast_int_to_float<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
         // All inputs greater or equal to (f32::MAX + 0.5 ULP) are rounded to infinity,
         // and for everything else LLVM's uitofp works just fine.
         use rustc_apfloat::ieee::Single;
-        use rustc_apfloat::Float;
         const MAX_F32_PLUS_HALF_ULP: u128 = ((1 << (Single::PRECISION + 1)) - 1)
                                             << (Single::MAX_EXP - Single::PRECISION as i16);
         let max = bx.cx().const_uint_big(int_ty, MAX_F32_PLUS_HALF_ULP);
diff --git a/src/librustc_errors/lib.rs b/src/librustc_errors/lib.rs
index 6b4b437930d2..ebbc5a3d3a34 100644
--- a/src/librustc_errors/lib.rs
+++ b/src/librustc_errors/lib.rs
@@ -155,7 +155,7 @@ impl CodeSuggestion {
     /// Returns the assembled code suggestions and whether they should be shown with an underline.
     pub fn splice_lines(&self, cm: &SourceMapperDyn)
                         -> Vec<(String, Vec<SubstitutionPart>)> {
-        use syntax_pos::{CharPos, Loc, Pos};
+        use syntax_pos::{CharPos, Pos};
 
         fn push_trailing(buf: &mut String,
                          line_opt: Option<&Cow<'_, str>>,
diff --git a/src/librustc_interface/profile/mod.rs b/src/librustc_interface/profile/mod.rs
index d0c8dff20708..2e71d46f4154 100644
--- a/src/librustc_interface/profile/mod.rs
+++ b/src/librustc_interface/profile/mod.rs
@@ -62,7 +62,6 @@ fn total_duration(traces: &[trace::Rec]) -> Duration {
 fn profile_queries_thread(r: Receiver<ProfileQueriesMsg>) {
     use self::trace::*;
     use std::fs::File;
-    use std::time::{Instant};
 
     let mut profq_msgs: Vec<ProfileQueriesMsg> = vec![];
     let mut frame: StackFrame = StackFrame { parse_st: ParseState::Clear, traces: vec![] };
diff --git a/src/librustc_mir/hair/pattern/mod.rs b/src/librustc_mir/hair/pattern/mod.rs
index 6c532fce57f0..622cf00ed86e 100644
--- a/src/librustc_mir/hair/pattern/mod.rs
+++ b/src/librustc_mir/hair/pattern/mod.rs
@@ -427,7 +427,6 @@ impl<'a, 'tcx> PatternContext<'a, 'tcx> {
 
                 let mut kind = match (lo, hi) {
                     (PatternKind::Constant { value: lo }, PatternKind::Constant { value: hi }) => {
-                        use std::cmp::Ordering;
                         let cmp = compare_const_vals(
                             self.tcx,
                             lo,
diff --git a/src/librustc_mir/interpret/operator.rs b/src/librustc_mir/interpret/operator.rs
index ca93007788e0..488f81d8f740 100644
--- a/src/librustc_mir/interpret/operator.rs
+++ b/src/librustc_mir/interpret/operator.rs
@@ -331,8 +331,6 @@ impl<'a, 'mir, 'tcx, M: Machine<'a, 'mir, 'tcx>> InterpretCx<'a, 'mir, 'tcx, M>
         val: ImmTy<'tcx, M::PointerTag>,
     ) -> EvalResult<'tcx, Scalar<M::PointerTag>> {
         use rustc::mir::UnOp::*;
-        use rustc_apfloat::ieee::{Single, Double};
-        use rustc_apfloat::Float;
 
         let layout = val.layout;
         let val = val.to_scalar()?;
diff --git a/src/librustc_resolve/lib.rs b/src/librustc_resolve/lib.rs
index ab3d87fafdac..3703ea08b625 100644
--- a/src/librustc_resolve/lib.rs
+++ b/src/librustc_resolve/lib.rs
@@ -1738,7 +1738,6 @@ impl<'a> Resolver<'a> {
     /// just that an error occurred.
     pub fn resolve_str_path_error(&mut self, span: Span, path_str: &str, is_value: bool)
         -> Result<hir::Path, ()> {
-        use std::iter;
         let mut errored = false;
 
         let path = if path_str.starts_with("::") {
diff --git a/src/librustc_traits/lowering/environment.rs b/src/librustc_traits/lowering/environment.rs
index 3570cb102460..eb47892ea410 100644
--- a/src/librustc_traits/lowering/environment.rs
+++ b/src/librustc_traits/lowering/environment.rs
@@ -164,7 +164,7 @@ crate fn environment<'a, 'tcx>(
     tcx: TyCtxt<'a, 'tcx, 'tcx>,
     def_id: DefId
 ) -> Environment<'tcx> {
-    use super::{Lower, IntoFromEnvGoal};
+    use super::IntoFromEnvGoal;
     use rustc::hir::{Node, TraitItemKind, ImplItemKind, ItemKind, ForeignItemKind};
 
     debug!("environment(def_id = {:?})", def_id);
diff --git a/src/librustc_typeck/check/wfcheck.rs b/src/librustc_typeck/check/wfcheck.rs
index 920270b5473c..3579810b8d75 100644
--- a/src/librustc_typeck/check/wfcheck.rs
+++ b/src/librustc_typeck/check/wfcheck.rs
@@ -420,9 +420,6 @@ fn check_where_clauses<'a, 'gcx, 'fcx, 'tcx>(
     def_id: DefId,
     return_ty: Option<Ty<'tcx>>,
 ) {
-    use ty::subst::Subst;
-    use rustc::ty::TypeFoldable;
-
     let predicates = fcx.tcx.predicates_of(def_id);
 
     let generics = tcx.generics_of(def_id);
@@ -1010,8 +1007,6 @@ fn check_false_global_bounds<'a, 'gcx, 'tcx>(
     span: Span,
     id: hir::HirId)
 {
-    use rustc::ty::TypeFoldable;
-
     let empty_env = ty::ParamEnv::empty();
 
     let def_id = fcx.tcx.hir().local_def_id_from_hir_id(id);

From 2cebbe25995f308fe6ed72a246f9d2ea633addf9 Mon Sep 17 00:00:00 2001
From: Fabian Drinck <fabian.drinck@rwth-aachen.de>
Date: Sat, 16 Mar 2019 16:49:13 +0100
Subject: [PATCH 08/30] Edit comments

---
 src/librustc_resolve/resolve_imports.rs | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/librustc_resolve/resolve_imports.rs b/src/librustc_resolve/resolve_imports.rs
index b40b68b08534..534e5e0ff45a 100644
--- a/src/librustc_resolve/resolve_imports.rs
+++ b/src/librustc_resolve/resolve_imports.rs
@@ -1252,11 +1252,13 @@ impl<'a, 'b:'a> ImportResolver<'a, 'b> {
         target_bindings: &PerNS<Cell<Option<&'b NameBinding<'b>>>>,
         target: Ident,
     ) {
-        // Check if we are at the root of a macro expansion and skip if we are.
+        // Skip if the import was produced by a macro.
         if directive.parent_scope.expansion != Mark::root() {
             return;
         }
 
+        // Skip if we are inside a named module (in contrast to an anonymous
+        // module defined by a block).
         if let ModuleKind::Def(_, _) = directive.parent_scope.module.kind {
             return;
         }

From 2245d10fac9b37c55a286f48d8560fc9537cbc3e Mon Sep 17 00:00:00 2001
From: Fabian Drinck <fabian.drinck@rwth-aachen.de>
Date: Sat, 16 Mar 2019 17:38:12 +0100
Subject: [PATCH 09/30] Improve warning

---
 src/librustc/lint/builtin.rs            |  9 +++++++++
 src/librustc_resolve/resolve_imports.rs | 15 +++++----------
 src/test/ui/lint/use-redundant.stderr   | 11 ++++-------
 3 files changed, 18 insertions(+), 17 deletions(-)

diff --git a/src/librustc/lint/builtin.rs b/src/librustc/lint/builtin.rs
index 615bc0af37a1..002ee5994005 100644
--- a/src/librustc/lint/builtin.rs
+++ b/src/librustc/lint/builtin.rs
@@ -489,6 +489,7 @@ pub enum BuiltinLintDiagnostics {
     UnknownCrateTypes(Span, String, String),
     UnusedImports(String, Vec<(Span, String)>),
     NestedImplTrait { outer_impl_trait_span: Span, inner_impl_trait_span: Span },
+    RedundantImport(Vec<Span>, ast::Ident),
 }
 
 impl BuiltinLintDiagnostics {
@@ -585,6 +586,14 @@ impl BuiltinLintDiagnostics {
                 db.span_label(outer_impl_trait_span, "outer `impl Trait`");
                 db.span_label(inner_impl_trait_span, "nested `impl Trait` here");
             }
+            BuiltinLintDiagnostics::RedundantImport(spans, ident) => {
+                for span in spans {
+                    db.span_label(
+                        span,
+                        format!("the item `{}` was already imported here", ident)
+                    );
+                }
+            }
         }
     }
 }
diff --git a/src/librustc_resolve/resolve_imports.rs b/src/librustc_resolve/resolve_imports.rs
index 534e5e0ff45a..cd018d8eb9e2 100644
--- a/src/librustc_resolve/resolve_imports.rs
+++ b/src/librustc_resolve/resolve_imports.rs
@@ -1306,21 +1306,16 @@ impl<'a, 'b:'a> ImportResolver<'a, 'b> {
         if !is_redundant.is_empty() &&
             is_redundant.present_items().all(|is_redundant| is_redundant)
         {
-            self.session.buffer_lint(
+            self.session.buffer_lint_with_diagnostic(
                 REDUNDANT_IMPORT,
                 directive.id,
                 directive.span,
                 &format!("the item `{}` is imported redundantly", ident),
+                BuiltinLintDiagnostics::RedundantImport(
+                    redundant_span.present_items().collect(),
+                    ident,
+                ),
             );
-
-            for span in redundant_span.present_items() {
-                self.session.buffer_lint(
-                    REDUNDANT_IMPORT,
-                    directive.id,
-                    span,
-                    "another import"
-                );
-            }
         }
     }
 
diff --git a/src/test/ui/lint/use-redundant.stderr b/src/test/ui/lint/use-redundant.stderr
index 6a6becc5e615..c843ed160df0 100644
--- a/src/test/ui/lint/use-redundant.stderr
+++ b/src/test/ui/lint/use-redundant.stderr
@@ -1,14 +1,11 @@
 warning: the item `Bar` is imported redundantly
   --> $DIR/use-redundant.rs:14:9
    |
-LL |     use crate::foo::Bar; //~ WARNING redundant import
+LL | use crate::foo::Bar;
+   |     --------------- the item `Bar` was already imported here
+...
+LL |     use crate::foo::Bar;
    |         ^^^^^^^^^^^^^^^
    |
    = note: #[warn(redundant_import)] on by default
 
-warning: another import
-  --> $DIR/use-redundant.rs:3:5
-   |
-LL | use crate::foo::Bar; //~ WARNING first import
-   |     ^^^^^^^^^^^^^^^
-

From d04e83fe2c51acd2c8e89c03d15deb7e1896bb8b Mon Sep 17 00:00:00 2001
From: Fabian Drinck <fabian.drinck@rwth-aachen.de>
Date: Sat, 16 Mar 2019 18:08:51 +0100
Subject: [PATCH 10/30] Bless tests

---
 src/test/ui/lint/lint-unused-imports.stderr   | 23 ++++++++++
 .../rust-2018/future-proofing-locals.stderr   | 46 +++++++++++++++++++
 2 files changed, 69 insertions(+)

diff --git a/src/test/ui/lint/lint-unused-imports.stderr b/src/test/ui/lint/lint-unused-imports.stderr
index f9a54f477f99..bf194696f618 100644
--- a/src/test/ui/lint/lint-unused-imports.stderr
+++ b/src/test/ui/lint/lint-unused-imports.stderr
@@ -34,12 +34,35 @@ error: unused import: `foo::Square`
 LL |         use foo::Square;
    |             ^^^^^^^^^^^
 
+warning: the item `g` is imported redundantly
+  --> $DIR/lint-unused-imports.rs:68:9
+   |
+LL | / fn g() {
+LL | |     use self::g;
+   | |         ^^^^^^^
+LL | |     fn f() {
+LL | |         self::g();
+LL | |     }
+LL | | }
+   | |_- the item `g` was already imported here
+   |
+   = note: #[warn(redundant_import)] on by default
+
 error: unused import: `self::g`
   --> $DIR/lint-unused-imports.rs:68:9
    |
 LL |     use self::g;
    |         ^^^^^^^
 
+warning: the item `foo` is imported redundantly
+  --> $DIR/lint-unused-imports.rs:77:9
+   |
+LL | use test2::{foo, bar};
+   |             --- the item `foo` was already imported here
+...
+LL |     use test2::foo;
+   |         ^^^^^^^^^^
+
 error: unused import: `test2::foo`
   --> $DIR/lint-unused-imports.rs:77:9
    |
diff --git a/src/test/ui/rust-2018/future-proofing-locals.stderr b/src/test/ui/rust-2018/future-proofing-locals.stderr
index 4d666d22afed..fa8333b5d211 100644
--- a/src/test/ui/rust-2018/future-proofing-locals.stderr
+++ b/src/test/ui/rust-2018/future-proofing-locals.stderr
@@ -52,5 +52,51 @@ error: imports cannot refer to local variables
 LL |     use {T as _, x};
    |                  ^
 
+warning: the item `T` is imported redundantly
+  --> $DIR/future-proofing-locals.rs:19:9
+   |
+LL | / mod T {
+LL | |     pub struct U;
+LL | | }
+   | |_- the item `T` was already imported here
+...
+LL |       use T;
+   |           ^
+   |
+   = note: #[warn(redundant_import)] on by default
+
+warning: the item `x` is imported redundantly
+  --> $DIR/future-proofing-locals.rs:31:9
+   |
+LL | / mod x {
+LL | |     pub struct y;
+LL | | }
+   | |_- the item `x` was already imported here
+...
+LL |       use x;
+   |           ^
+
+warning: the item `x` is imported redundantly
+  --> $DIR/future-proofing-locals.rs:37:17
+   |
+LL | / mod x {
+LL | |     pub struct y;
+LL | | }
+   | |_- the item `x` was already imported here
+...
+LL |               use x;
+   |                   ^
+
+warning: the item `x` is imported redundantly
+  --> $DIR/future-proofing-locals.rs:45:18
+   |
+LL | / mod x {
+LL | |     pub struct y;
+LL | | }
+   | |_- the item `x` was already imported here
+...
+LL |       use {T as _, x};
+   |                    ^
+
 error: aborting due to 9 previous errors
 

From 8919894c513a8f8eadacd9555afee7a6d095665c Mon Sep 17 00:00:00 2001
From: Fabian Drinck <fabian.drinck@rwth-aachen.de>
Date: Sat, 16 Mar 2019 19:06:22 +0100
Subject: [PATCH 11/30] Distinguish between imported and defined items

---
 src/librustc/lint/builtin.rs            | 7 ++++---
 src/librustc_resolve/resolve_imports.rs | 3 ++-
 src/test/ui/lint/use-redundant.stderr   | 2 +-
 3 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/src/librustc/lint/builtin.rs b/src/librustc/lint/builtin.rs
index 002ee5994005..462f0947338b 100644
--- a/src/librustc/lint/builtin.rs
+++ b/src/librustc/lint/builtin.rs
@@ -489,7 +489,7 @@ pub enum BuiltinLintDiagnostics {
     UnknownCrateTypes(Span, String, String),
     UnusedImports(String, Vec<(Span, String)>),
     NestedImplTrait { outer_impl_trait_span: Span, inner_impl_trait_span: Span },
-    RedundantImport(Vec<Span>, ast::Ident),
+    RedundantImport(Vec<(Span, bool)>, ast::Ident),
 }
 
 impl BuiltinLintDiagnostics {
@@ -587,10 +587,11 @@ impl BuiltinLintDiagnostics {
                 db.span_label(inner_impl_trait_span, "nested `impl Trait` here");
             }
             BuiltinLintDiagnostics::RedundantImport(spans, ident) => {
-                for span in spans {
+                for (span, is_imported) in spans {
+                    let introduced = if is_imported { "imported" } else { "defined" };
                     db.span_label(
                         span,
-                        format!("the item `{}` was already imported here", ident)
+                        format!("the item `{}` was {} here", ident, introduced)
                     );
                 }
             }
diff --git a/src/librustc_resolve/resolve_imports.rs b/src/librustc_resolve/resolve_imports.rs
index cd018d8eb9e2..eacbf81347aa 100644
--- a/src/librustc_resolve/resolve_imports.rs
+++ b/src/librustc_resolve/resolve_imports.rs
@@ -1295,7 +1295,8 @@ impl<'a, 'b:'a> ImportResolver<'a, 'b> {
             ) {
                 Ok(other_binding) => {
                     is_redundant[ns] = Some(binding.def() == other_binding.def());
-                    redundant_span[ns] = Some(other_binding.span);
+                    redundant_span[ns] =
+                        Some((other_binding.span, other_binding.is_import()));
                 }
                 Err(_) => is_redundant[ns] = Some(false)
             }
diff --git a/src/test/ui/lint/use-redundant.stderr b/src/test/ui/lint/use-redundant.stderr
index c843ed160df0..b5000b22a1da 100644
--- a/src/test/ui/lint/use-redundant.stderr
+++ b/src/test/ui/lint/use-redundant.stderr
@@ -2,7 +2,7 @@ warning: the item `Bar` is imported redundantly
   --> $DIR/use-redundant.rs:14:9
    |
 LL | use crate::foo::Bar;
-   |     --------------- the item `Bar` was already imported here
+   |     --------------- the item `Bar` was imported here
 ...
 LL |     use crate::foo::Bar;
    |         ^^^^^^^^^^^^^^^

From fef3f5c88d660277c85909af36edd3e121a0d576 Mon Sep 17 00:00:00 2001
From: Fabian Drinck <fabian.drinck@rwth-aachen.de>
Date: Sat, 16 Mar 2019 19:19:40 +0100
Subject: [PATCH 12/30] Remove redundant import

---
 src/librustdoc/html/render.rs | 2 --
 src/librustdoc/test.rs        | 3 +--
 2 files changed, 1 insertion(+), 4 deletions(-)

diff --git a/src/librustdoc/html/render.rs b/src/librustdoc/html/render.rs
index 9220d2feed2d..f7e8cdeaeca8 100644
--- a/src/librustdoc/html/render.rs
+++ b/src/librustdoc/html/render.rs
@@ -1069,8 +1069,6 @@ themePicker.onblur = handleThemeButtonsBlur;
     }
 
     if cx.shared.include_sources {
-        use std::path::Component;
-
         let mut hierarchy = Hierarchy::new(OsString::new());
         for source in cx.shared.local_sources.iter()
                                              .filter_map(|p| p.0.strip_prefix(&cx.shared.src_root)
diff --git a/src/librustdoc/test.rs b/src/librustdoc/test.rs
index f1d4d8470b2a..0bbc7c5c4b22 100644
--- a/src/librustdoc/test.rs
+++ b/src/librustdoc/test.rs
@@ -371,8 +371,7 @@ pub fn make_test(s: &str,
     // Uses libsyntax to parse the doctest and find if there's a main fn and the extern
     // crate already is included.
     let (already_has_main, already_has_extern_crate, found_macro) = crate::syntax::with_globals(|| {
-        use crate::syntax::{ast, parse::{self, ParseSess}, source_map::FilePathMapping};
-        use crate::syntax_pos::FileName;
+        use crate::syntax::{parse::{self, ParseSess}, source_map::FilePathMapping};
         use errors::emitter::EmitterWriter;
         use errors::Handler;
 

From f9272364bf443ec29cf9cc3548f37a7579b35bfd Mon Sep 17 00:00:00 2001
From: Fabian Drinck <fabian.drinck@rwth-aachen.de>
Date: Sat, 16 Mar 2019 19:21:03 +0100
Subject: [PATCH 13/30] Edit ui tests

---
 src/test/ui/lint/lint-unused-imports.rs         | 1 +
 src/test/ui/rust-2018/future-proofing-locals.rs | 1 +
 2 files changed, 2 insertions(+)

diff --git a/src/test/ui/lint/lint-unused-imports.rs b/src/test/ui/lint/lint-unused-imports.rs
index 9c5b206203c1..c7ffdc270c94 100644
--- a/src/test/ui/lint/lint-unused-imports.rs
+++ b/src/test/ui/lint/lint-unused-imports.rs
@@ -1,5 +1,6 @@
 #![deny(unused_imports)]
 #![allow(dead_code)]
+#![allow(redundant_import)]
 
 use bar::c::cc as cal;
 
diff --git a/src/test/ui/rust-2018/future-proofing-locals.rs b/src/test/ui/rust-2018/future-proofing-locals.rs
index 1e53c2d1daca..df3badb94e5f 100644
--- a/src/test/ui/rust-2018/future-proofing-locals.rs
+++ b/src/test/ui/rust-2018/future-proofing-locals.rs
@@ -1,6 +1,7 @@
 // edition:2018
 
 #![allow(non_camel_case_types)]
+#![allow(redundant_import)]
 
 mod T {
     pub struct U;

From 6e7b45e12b76cad70262281d5fae7ad98032fafc Mon Sep 17 00:00:00 2001
From: Fabian Drinck <fabian.drinck@rwth-aachen.de>
Date: Sun, 17 Mar 2019 09:49:31 +0100
Subject: [PATCH 14/30] Replace REDUNDANT_IMPORT with UNUSED_IMPORTS

---
 src/librustc/lint/builtin.rs                  |  8 +--
 src/librustc_resolve/resolve_imports.rs       |  4 +-
 src/test/ui/lint/lint-unused-imports.rs       |  1 -
 src/test/ui/lint/lint-unused-imports.stderr   | 10 ++-
 .../ui/rust-2018/future-proofing-locals.rs    |  2 +-
 .../rust-2018/future-proofing-locals.stderr   | 64 +++----------------
 6 files changed, 17 insertions(+), 72 deletions(-)

diff --git a/src/librustc/lint/builtin.rs b/src/librustc/lint/builtin.rs
index 462f0947338b..6908674bc13a 100644
--- a/src/librustc/lint/builtin.rs
+++ b/src/librustc/lint/builtin.rs
@@ -392,12 +392,6 @@ declare_lint! {
     "nested occurrence of `impl Trait` type"
 }
 
-declare_lint! {
-    pub REDUNDANT_IMPORT,
-    Warn,
-    "redundant import"
-}
-
 /// Does nothing as a lint pass, but registers some `Lint`s
 /// that are used by other parts of the compiler.
 #[derive(Copy, Clone)]
@@ -591,7 +585,7 @@ impl BuiltinLintDiagnostics {
                     let introduced = if is_imported { "imported" } else { "defined" };
                     db.span_label(
                         span,
-                        format!("the item `{}` was {} here", ident, introduced)
+                        format!("the item `{}` was already {} here", ident, introduced)
                     );
                 }
             }
diff --git a/src/librustc_resolve/resolve_imports.rs b/src/librustc_resolve/resolve_imports.rs
index eacbf81347aa..99e20c398d92 100644
--- a/src/librustc_resolve/resolve_imports.rs
+++ b/src/librustc_resolve/resolve_imports.rs
@@ -18,7 +18,7 @@ use rustc::lint::builtin::BuiltinLintDiagnostics;
 use rustc::lint::builtin::{
     DUPLICATE_MACRO_EXPORTS,
     PUB_USE_OF_PRIVATE_EXTERN_CRATE,
-    REDUNDANT_IMPORT,
+    UNUSED_IMPORTS,
 };
 use rustc::hir::def_id::{CrateNum, DefId};
 use rustc::hir::def::*;
@@ -1308,7 +1308,7 @@ impl<'a, 'b:'a> ImportResolver<'a, 'b> {
             is_redundant.present_items().all(|is_redundant| is_redundant)
         {
             self.session.buffer_lint_with_diagnostic(
-                REDUNDANT_IMPORT,
+                UNUSED_IMPORTS,
                 directive.id,
                 directive.span,
                 &format!("the item `{}` is imported redundantly", ident),
diff --git a/src/test/ui/lint/lint-unused-imports.rs b/src/test/ui/lint/lint-unused-imports.rs
index c7ffdc270c94..9c5b206203c1 100644
--- a/src/test/ui/lint/lint-unused-imports.rs
+++ b/src/test/ui/lint/lint-unused-imports.rs
@@ -1,6 +1,5 @@
 #![deny(unused_imports)]
 #![allow(dead_code)]
-#![allow(redundant_import)]
 
 use bar::c::cc as cal;
 
diff --git a/src/test/ui/lint/lint-unused-imports.stderr b/src/test/ui/lint/lint-unused-imports.stderr
index bf194696f618..62490972420a 100644
--- a/src/test/ui/lint/lint-unused-imports.stderr
+++ b/src/test/ui/lint/lint-unused-imports.stderr
@@ -34,7 +34,7 @@ error: unused import: `foo::Square`
 LL |         use foo::Square;
    |             ^^^^^^^^^^^
 
-warning: the item `g` is imported redundantly
+error: the item `g` is imported redundantly
   --> $DIR/lint-unused-imports.rs:68:9
    |
 LL | / fn g() {
@@ -44,9 +44,7 @@ LL | |     fn f() {
 LL | |         self::g();
 LL | |     }
 LL | | }
-   | |_- the item `g` was already imported here
-   |
-   = note: #[warn(redundant_import)] on by default
+   | |_- the item `g` was already defined here
 
 error: unused import: `self::g`
   --> $DIR/lint-unused-imports.rs:68:9
@@ -54,7 +52,7 @@ error: unused import: `self::g`
 LL |     use self::g;
    |         ^^^^^^^
 
-warning: the item `foo` is imported redundantly
+error: the item `foo` is imported redundantly
   --> $DIR/lint-unused-imports.rs:77:9
    |
 LL | use test2::{foo, bar};
@@ -75,5 +73,5 @@ error: unused import: `test::B2`
 LL | use test::B2;
    |     ^^^^^^^^
 
-error: aborting due to 8 previous errors
+error: aborting due to 10 previous errors
 
diff --git a/src/test/ui/rust-2018/future-proofing-locals.rs b/src/test/ui/rust-2018/future-proofing-locals.rs
index df3badb94e5f..2c388cf3713b 100644
--- a/src/test/ui/rust-2018/future-proofing-locals.rs
+++ b/src/test/ui/rust-2018/future-proofing-locals.rs
@@ -1,7 +1,7 @@
 // edition:2018
 
 #![allow(non_camel_case_types)]
-#![allow(redundant_import)]
+#![allow(unused_imports)]
 
 mod T {
     pub struct U;
diff --git a/src/test/ui/rust-2018/future-proofing-locals.stderr b/src/test/ui/rust-2018/future-proofing-locals.stderr
index fa8333b5d211..7021489a6ddc 100644
--- a/src/test/ui/rust-2018/future-proofing-locals.stderr
+++ b/src/test/ui/rust-2018/future-proofing-locals.stderr
@@ -1,102 +1,56 @@
 error: imports cannot refer to type parameters
-  --> $DIR/future-proofing-locals.rs:13:9
+  --> $DIR/future-proofing-locals.rs:14:9
    |
 LL |     use T as _;
    |         ^
 
 error: imports cannot refer to type parameters
-  --> $DIR/future-proofing-locals.rs:14:9
+  --> $DIR/future-proofing-locals.rs:15:9
    |
 LL |     use T::U;
    |         ^
 
 error: imports cannot refer to type parameters
-  --> $DIR/future-proofing-locals.rs:15:9
+  --> $DIR/future-proofing-locals.rs:16:9
    |
 LL |     use T::*;
    |         ^
 
 error: imports cannot refer to type parameters
-  --> $DIR/future-proofing-locals.rs:19:9
+  --> $DIR/future-proofing-locals.rs:20:9
    |
 LL |     use T;
    |         ^
 
 error: imports cannot refer to local variables
-  --> $DIR/future-proofing-locals.rs:25:9
+  --> $DIR/future-proofing-locals.rs:26:9
    |
 LL |     use x as _;
    |         ^
 
 error: imports cannot refer to local variables
-  --> $DIR/future-proofing-locals.rs:31:9
+  --> $DIR/future-proofing-locals.rs:32:9
    |
 LL |     use x;
    |         ^
 
 error: imports cannot refer to local variables
-  --> $DIR/future-proofing-locals.rs:37:17
+  --> $DIR/future-proofing-locals.rs:38:17
    |
 LL |             use x;
    |                 ^
 
 error: imports cannot refer to type parameters
-  --> $DIR/future-proofing-locals.rs:45:10
+  --> $DIR/future-proofing-locals.rs:46:10
    |
 LL |     use {T as _, x};
    |          ^
 
 error: imports cannot refer to local variables
-  --> $DIR/future-proofing-locals.rs:45:18
+  --> $DIR/future-proofing-locals.rs:46:18
    |
 LL |     use {T as _, x};
    |                  ^
 
-warning: the item `T` is imported redundantly
-  --> $DIR/future-proofing-locals.rs:19:9
-   |
-LL | / mod T {
-LL | |     pub struct U;
-LL | | }
-   | |_- the item `T` was already imported here
-...
-LL |       use T;
-   |           ^
-   |
-   = note: #[warn(redundant_import)] on by default
-
-warning: the item `x` is imported redundantly
-  --> $DIR/future-proofing-locals.rs:31:9
-   |
-LL | / mod x {
-LL | |     pub struct y;
-LL | | }
-   | |_- the item `x` was already imported here
-...
-LL |       use x;
-   |           ^
-
-warning: the item `x` is imported redundantly
-  --> $DIR/future-proofing-locals.rs:37:17
-   |
-LL | / mod x {
-LL | |     pub struct y;
-LL | | }
-   | |_- the item `x` was already imported here
-...
-LL |               use x;
-   |                   ^
-
-warning: the item `x` is imported redundantly
-  --> $DIR/future-proofing-locals.rs:45:18
-   |
-LL | / mod x {
-LL | |     pub struct y;
-LL | | }
-   | |_- the item `x` was already imported here
-...
-LL |       use {T as _, x};
-   |                    ^
-
 error: aborting due to 9 previous errors
 

From 0f3b1c035837fc5e101d5a2d8c49b1d5128927b5 Mon Sep 17 00:00:00 2001
From: Fabian Drinck <fabian.drinck@rwth-aachen.de>
Date: Sun, 17 Mar 2019 11:38:38 +0100
Subject: [PATCH 15/30] Fix tests

---
 src/test/ui/lint/lint-unused-imports.rs     |  2 ++
 src/test/ui/lint/lint-unused-imports.stderr |  5 +++--
 src/test/ui/lint/use-redundant.rs           |  1 +
 src/test/ui/lint/use-redundant.stderr       | 10 +++++++---
 4 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/src/test/ui/lint/lint-unused-imports.rs b/src/test/ui/lint/lint-unused-imports.rs
index 9c5b206203c1..4754d8880763 100644
--- a/src/test/ui/lint/lint-unused-imports.rs
+++ b/src/test/ui/lint/lint-unused-imports.rs
@@ -66,6 +66,7 @@ mod bar {
 
 fn g() {
     use self::g; //~ ERROR unused import: `self::g`
+    //~^ ERROR the item `g` is imported redundantly
     fn f() {
         self::g();
     }
@@ -75,6 +76,7 @@ fn g() {
 #[allow(unused_variables)]
 fn h() {
     use test2::foo; //~ ERROR unused import: `test2::foo`
+    //~^ ERROR the item `foo` is imported redundantly
     let foo = 0;
 }
 
diff --git a/src/test/ui/lint/lint-unused-imports.stderr b/src/test/ui/lint/lint-unused-imports.stderr
index 62490972420a..b37f25ec0174 100644
--- a/src/test/ui/lint/lint-unused-imports.stderr
+++ b/src/test/ui/lint/lint-unused-imports.stderr
@@ -40,6 +40,7 @@ error: the item `g` is imported redundantly
 LL | / fn g() {
 LL | |     use self::g;
    | |         ^^^^^^^
+LL | |
 LL | |     fn f() {
 LL | |         self::g();
 LL | |     }
@@ -53,7 +54,7 @@ LL |     use self::g;
    |         ^^^^^^^
 
 error: the item `foo` is imported redundantly
-  --> $DIR/lint-unused-imports.rs:77:9
+  --> $DIR/lint-unused-imports.rs:78:9
    |
 LL | use test2::{foo, bar};
    |             --- the item `foo` was already imported here
@@ -62,7 +63,7 @@ LL |     use test2::foo;
    |         ^^^^^^^^^^
 
 error: unused import: `test2::foo`
-  --> $DIR/lint-unused-imports.rs:77:9
+  --> $DIR/lint-unused-imports.rs:78:9
    |
 LL |     use test2::foo;
    |         ^^^^^^^^^^
diff --git a/src/test/ui/lint/use-redundant.rs b/src/test/ui/lint/use-redundant.rs
index 50d4d30625a6..7abf5e498b53 100644
--- a/src/test/ui/lint/use-redundant.rs
+++ b/src/test/ui/lint/use-redundant.rs
@@ -1,4 +1,5 @@
 // compile-pass
+#![warn(unused_imports)]
 
 use crate::foo::Bar; //~ WARNING first import
 
diff --git a/src/test/ui/lint/use-redundant.stderr b/src/test/ui/lint/use-redundant.stderr
index b5000b22a1da..b25ffc6073f4 100644
--- a/src/test/ui/lint/use-redundant.stderr
+++ b/src/test/ui/lint/use-redundant.stderr
@@ -1,11 +1,15 @@
 warning: the item `Bar` is imported redundantly
-  --> $DIR/use-redundant.rs:14:9
+  --> $DIR/use-redundant.rs:15:9
    |
 LL | use crate::foo::Bar;
-   |     --------------- the item `Bar` was imported here
+   |     --------------- the item `Bar` was already imported here
 ...
 LL |     use crate::foo::Bar;
    |         ^^^^^^^^^^^^^^^
    |
-   = note: #[warn(redundant_import)] on by default
+note: lint level defined here
+  --> $DIR/use-redundant.rs:2:9
+   |
+LL | #![warn(unused_imports)]
+   |         ^^^^^^^^^^^^^^
 

From 4a619aa1261c995abedc446226a7701c2c9e1c79 Mon Sep 17 00:00:00 2001
From: Fabian Drinck <fabian.drinck@rwth-aachen.de>
Date: Sun, 17 Mar 2019 11:55:32 +0100
Subject: [PATCH 16/30] Add glob import to redundancy test

---
 src/test/ui/lint/use-redundant.rs     |  9 ++++++++
 src/test/ui/lint/use-redundant.stderr | 33 ++++++++++++++++++++++-----
 2 files changed, 36 insertions(+), 6 deletions(-)

diff --git a/src/test/ui/lint/use-redundant.rs b/src/test/ui/lint/use-redundant.rs
index 7abf5e498b53..328f8232bafa 100644
--- a/src/test/ui/lint/use-redundant.rs
+++ b/src/test/ui/lint/use-redundant.rs
@@ -11,8 +11,17 @@ fn baz() -> Bar {
     3
 }
 
+mod m1 { pub struct S {} }
+mod m2 { pub struct S {} }
+
+use m1::*;
+use m2::*;
+
 fn main() {
     use crate::foo::Bar; //~ WARNING redundant import
     let _a: Bar = 3;
     baz();
+
+    use m1::S; //~ WARNING redundant import
+    let _s = S {};
 }
diff --git a/src/test/ui/lint/use-redundant.stderr b/src/test/ui/lint/use-redundant.stderr
index b25ffc6073f4..82d2312779e6 100644
--- a/src/test/ui/lint/use-redundant.stderr
+++ b/src/test/ui/lint/use-redundant.stderr
@@ -1,15 +1,36 @@
+warning: unused import: `m1::*`
+  --> $DIR/use-redundant.rs:17:5
+   |
+LL | use m1::*;
+   |     ^^^^^
+   |
+note: lint level defined here
+  --> $DIR/use-redundant.rs:2:9
+   |
+LL | #![warn(unused_imports)]
+   |         ^^^^^^^^^^^^^^
+
+warning: unused import: `m2::*`
+  --> $DIR/use-redundant.rs:18:5
+   |
+LL | use m2::*;
+   |     ^^^^^
+
 warning: the item `Bar` is imported redundantly
-  --> $DIR/use-redundant.rs:15:9
+  --> $DIR/use-redundant.rs:21:9
    |
 LL | use crate::foo::Bar;
    |     --------------- the item `Bar` was already imported here
 ...
 LL |     use crate::foo::Bar;
    |         ^^^^^^^^^^^^^^^
+
+warning: the item `S` is imported redundantly
+  --> $DIR/use-redundant.rs:25:9
    |
-note: lint level defined here
-  --> $DIR/use-redundant.rs:2:9
-   |
-LL | #![warn(unused_imports)]
-   |         ^^^^^^^^^^^^^^
+LL | use m1::*;
+   |     ----- the item `S` was already imported here
+...
+LL |     use m1::S;
+   |         ^^^^^
 

From a97aeb41d4d342136f52b3cdddc8d59beae606cc Mon Sep 17 00:00:00 2001
From: Fabian Drinck <fabian.drinck@rwth-aachen.de>
Date: Sun, 17 Mar 2019 13:30:42 +0100
Subject: [PATCH 17/30] Fix more tests

---
 src/test/run-pass/binding/match-arm-statics.rs                  | 2 --
 src/test/run-pass/ifmt.rs                                       | 2 --
 src/test/run-pass/invalid_const_promotion.rs                    | 1 -
 src/test/run-pass/issues/issue-38556.rs                         | 1 -
 src/test/run-pass/issues/issue-39367.rs                         | 1 -
 src/test/run-pass/out-of-stack.rs                               | 1 -
 src/test/run-pass/rfcs/rfc-2126-extern-absolute-paths/basic.rs  | 1 -
 .../traits/traits-multidispatch-infer-convert-target.rs         | 1 -
 8 files changed, 10 deletions(-)

diff --git a/src/test/run-pass/binding/match-arm-statics.rs b/src/test/run-pass/binding/match-arm-statics.rs
index 359c39211588..5f7e357eeb2a 100644
--- a/src/test/run-pass/binding/match-arm-statics.rs
+++ b/src/test/run-pass/binding/match-arm-statics.rs
@@ -45,8 +45,6 @@ pub mod glfw {
 }
 
 fn issue_6533() {
-    use glfw;
-
     fn action_to_str(state: glfw::InputState) -> &'static str {
         use glfw::{RELEASE, PRESS, REPEAT};
         match state {
diff --git a/src/test/run-pass/ifmt.rs b/src/test/run-pass/ifmt.rs
index 56222fa46f7c..8c17b01e2bd8 100644
--- a/src/test/run-pass/ifmt.rs
+++ b/src/test/run-pass/ifmt.rs
@@ -238,7 +238,6 @@ pub fn main() {
 // Basic test to make sure that we can invoke the `write!` macro with an
 // fmt::Write instance.
 fn test_write() {
-    use std::fmt::Write;
     let mut buf = String::new();
     write!(&mut buf, "{}", 3);
     {
@@ -267,7 +266,6 @@ fn test_print() {
 // Just make sure that the macros are defined, there's not really a lot that we
 // can do with them just yet (to test the output)
 fn test_format_args() {
-    use std::fmt::Write;
     let mut buf = String::new();
     {
         let w = &mut buf;
diff --git a/src/test/run-pass/invalid_const_promotion.rs b/src/test/run-pass/invalid_const_promotion.rs
index 1524373895d9..2775aac01561 100644
--- a/src/test/run-pass/invalid_const_promotion.rs
+++ b/src/test/run-pass/invalid_const_promotion.rs
@@ -25,7 +25,6 @@ fn foo() {
 #[cfg(unix)]
 fn check_status(status: std::process::ExitStatus)
 {
-    use libc;
     use std::os::unix::process::ExitStatusExt;
 
     assert!(status.signal() == Some(libc::SIGILL)
diff --git a/src/test/run-pass/issues/issue-38556.rs b/src/test/run-pass/issues/issue-38556.rs
index 0cc247f5b9ca..63fd9db08ff2 100644
--- a/src/test/run-pass/issues/issue-38556.rs
+++ b/src/test/run-pass/issues/issue-38556.rs
@@ -9,6 +9,5 @@ macro_rules! reexport {
 reexport!();
 
 fn main() {
-    use Bar;
     fn f(_: Bar) {}
 }
diff --git a/src/test/run-pass/issues/issue-39367.rs b/src/test/run-pass/issues/issue-39367.rs
index bd92224bce16..484cd782a09d 100644
--- a/src/test/run-pass/issues/issue-39367.rs
+++ b/src/test/run-pass/issues/issue-39367.rs
@@ -15,7 +15,6 @@ fn arena() -> &'static ArenaSet<Vec<u8>> {
         fn require_sync<T: Sync>(_: &T) { }
         unsafe fn __stability() -> &'static ArenaSet<Vec<u8>> {
             use std::mem::transmute;
-            use std::boxed::Box;
             static mut DATA: *const ArenaSet<Vec<u8>> = 0 as *const ArenaSet<Vec<u8>>;
 
             static mut ONCE: Once = ONCE_INIT;
diff --git a/src/test/run-pass/out-of-stack.rs b/src/test/run-pass/out-of-stack.rs
index 72d6d6806229..9f868d6e5c3e 100644
--- a/src/test/run-pass/out-of-stack.rs
+++ b/src/test/run-pass/out-of-stack.rs
@@ -36,7 +36,6 @@ fn loud_recurse() {
 #[cfg(unix)]
 fn check_status(status: std::process::ExitStatus)
 {
-    use libc;
     use std::os::unix::process::ExitStatusExt;
 
     assert!(!status.success());
diff --git a/src/test/run-pass/rfcs/rfc-2126-extern-absolute-paths/basic.rs b/src/test/run-pass/rfcs/rfc-2126-extern-absolute-paths/basic.rs
index 15449a6b83e2..f25d81f1c9a5 100644
--- a/src/test/run-pass/rfcs/rfc-2126-extern-absolute-paths/basic.rs
+++ b/src/test/run-pass/rfcs/rfc-2126-extern-absolute-paths/basic.rs
@@ -7,7 +7,6 @@
 use xcrate::Z;
 
 fn f() {
-    use xcrate;
     use xcrate as ycrate;
     let s = xcrate::S;
     assert_eq!(format!("{:?}", s), "S");
diff --git a/src/test/run-pass/traits/traits-multidispatch-infer-convert-target.rs b/src/test/run-pass/traits/traits-multidispatch-infer-convert-target.rs
index ca47d9736f63..626e1ae71bc2 100644
--- a/src/test/run-pass/traits/traits-multidispatch-infer-convert-target.rs
+++ b/src/test/run-pass/traits/traits-multidispatch-infer-convert-target.rs
@@ -28,7 +28,6 @@ where T : Convert<U>
 }
 
 fn main() {
-    use std::default::Default;
     // T = i16, U = u32
     test(22_i16, Default::default(),  2, 4);
 

From 8fb05491514c5cfb3c3aa03e0266389fa0b29ed0 Mon Sep 17 00:00:00 2001
From: Fabian Drinck <fabian.drinck@rwth-aachen.de>
Date: Sun, 17 Mar 2019 17:40:25 +0100
Subject: [PATCH 18/30] Fix doc tests

---
 src/liballoc/borrow.rs | 2 +-
 src/libcore/cell.rs    | 1 -
 2 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/src/liballoc/borrow.rs b/src/liballoc/borrow.rs
index 74c80a08b12a..ee1799fad8e1 100644
--- a/src/liballoc/borrow.rs
+++ b/src/liballoc/borrow.rs
@@ -135,7 +135,7 @@ impl<T> ToOwned for T
 /// Another example showing how to keep `Cow` in a struct:
 ///
 /// ```
-/// use std::borrow::{Cow, ToOwned};
+/// use std::borrow::Cow;
 ///
 /// struct Items<'a, X: 'a> where [X]: ToOwned<Owned = Vec<X>> {
 ///     values: Cow<'a, [X]>,
diff --git a/src/libcore/cell.rs b/src/libcore/cell.rs
index 753f10e6a0ad..3b888244341f 100644
--- a/src/libcore/cell.rs
+++ b/src/libcore/cell.rs
@@ -1421,7 +1421,6 @@ impl<T: ?Sized + fmt::Display> fmt::Display for RefMut<'_, T> {
 ///
 /// ```
 /// use std::cell::UnsafeCell;
-/// use std::marker::Sync;
 ///
 /// # #[allow(dead_code)]
 /// struct NotThreadSafe<T> {

From df80eae985e80e0907c1ebde4caf1d7cc8acbc21 Mon Sep 17 00:00:00 2001
From: Fabian Drinck <fabian.drinck@rwth-aachen.de>
Date: Sun, 17 Mar 2019 21:07:57 +0100
Subject: [PATCH 19/30] Change message to present tense

---
 src/librustc/lint/builtin.rs                | 2 +-
 src/test/ui/lint/lint-unused-imports.stderr | 4 ++--
 src/test/ui/lint/use-redundant.stderr       | 4 ++--
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/librustc/lint/builtin.rs b/src/librustc/lint/builtin.rs
index 6908674bc13a..2d8a2c6321fa 100644
--- a/src/librustc/lint/builtin.rs
+++ b/src/librustc/lint/builtin.rs
@@ -585,7 +585,7 @@ impl BuiltinLintDiagnostics {
                     let introduced = if is_imported { "imported" } else { "defined" };
                     db.span_label(
                         span,
-                        format!("the item `{}` was already {} here", ident, introduced)
+                        format!("the item `{}` is already {} here", ident, introduced)
                     );
                 }
             }
diff --git a/src/test/ui/lint/lint-unused-imports.stderr b/src/test/ui/lint/lint-unused-imports.stderr
index b37f25ec0174..96d71a228a5f 100644
--- a/src/test/ui/lint/lint-unused-imports.stderr
+++ b/src/test/ui/lint/lint-unused-imports.stderr
@@ -45,7 +45,7 @@ LL | |     fn f() {
 LL | |         self::g();
 LL | |     }
 LL | | }
-   | |_- the item `g` was already defined here
+   | |_- the item `g` is already defined here
 
 error: unused import: `self::g`
   --> $DIR/lint-unused-imports.rs:68:9
@@ -57,7 +57,7 @@ error: the item `foo` is imported redundantly
   --> $DIR/lint-unused-imports.rs:78:9
    |
 LL | use test2::{foo, bar};
-   |             --- the item `foo` was already imported here
+   |             --- the item `foo` is already imported here
 ...
 LL |     use test2::foo;
    |         ^^^^^^^^^^
diff --git a/src/test/ui/lint/use-redundant.stderr b/src/test/ui/lint/use-redundant.stderr
index 82d2312779e6..3554443590ab 100644
--- a/src/test/ui/lint/use-redundant.stderr
+++ b/src/test/ui/lint/use-redundant.stderr
@@ -20,7 +20,7 @@ warning: the item `Bar` is imported redundantly
   --> $DIR/use-redundant.rs:21:9
    |
 LL | use crate::foo::Bar;
-   |     --------------- the item `Bar` was already imported here
+   |     --------------- the item `Bar` is already imported here
 ...
 LL |     use crate::foo::Bar;
    |         ^^^^^^^^^^^^^^^
@@ -29,7 +29,7 @@ warning: the item `S` is imported redundantly
   --> $DIR/use-redundant.rs:25:9
    |
 LL | use m1::*;
-   |     ----- the item `S` was already imported here
+   |     ----- the item `S` is already imported here
 ...
 LL |     use m1::S;
    |         ^^^^^

From c244c411e4c869a76c7a8163b67840bdf83674e6 Mon Sep 17 00:00:00 2001
From: Fabian Drinck <fabian.drinck@rwth-aachen.de>
Date: Mon, 18 Mar 2019 17:50:49 +0100
Subject: [PATCH 20/30] Handle glob import in redundancy check

---
 src/librustc_resolve/resolve_imports.rs | 5 ++++-
 src/test/ui/lint/use-redundant.stderr   | 9 ---------
 2 files changed, 4 insertions(+), 10 deletions(-)

diff --git a/src/librustc_resolve/resolve_imports.rs b/src/librustc_resolve/resolve_imports.rs
index 99e20c398d92..7ea07f5e0cbc 100644
--- a/src/librustc_resolve/resolve_imports.rs
+++ b/src/librustc_resolve/resolve_imports.rs
@@ -1294,7 +1294,10 @@ impl<'a, 'b:'a> ImportResolver<'a, 'b> {
                 directive.span,
             ) {
                 Ok(other_binding) => {
-                    is_redundant[ns] = Some(binding.def() == other_binding.def());
+                    is_redundant[ns] = Some(
+                        binding.def() == other_binding.def()
+                        && !other_binding.is_ambiguity()
+                    );
                     redundant_span[ns] =
                         Some((other_binding.span, other_binding.is_import()));
                 }
diff --git a/src/test/ui/lint/use-redundant.stderr b/src/test/ui/lint/use-redundant.stderr
index 3554443590ab..fbd9f81f18f8 100644
--- a/src/test/ui/lint/use-redundant.stderr
+++ b/src/test/ui/lint/use-redundant.stderr
@@ -25,12 +25,3 @@ LL | use crate::foo::Bar;
 LL |     use crate::foo::Bar;
    |         ^^^^^^^^^^^^^^^
 
-warning: the item `S` is imported redundantly
-  --> $DIR/use-redundant.rs:25:9
-   |
-LL | use m1::*;
-   |     ----- the item `S` is already imported here
-...
-LL |     use m1::S;
-   |         ^^^^^
-

From 2ade4430402dcbe3bba9a17a13cb290f73f5a477 Mon Sep 17 00:00:00 2001
From: Fabian Drinck <fabian.drinck@rwth-aachen.de>
Date: Mon, 18 Mar 2019 17:51:00 +0100
Subject: [PATCH 21/30] Restore test

---
 src/test/run-pass/rfcs/rfc-2126-extern-absolute-paths/basic.rs | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/test/run-pass/rfcs/rfc-2126-extern-absolute-paths/basic.rs b/src/test/run-pass/rfcs/rfc-2126-extern-absolute-paths/basic.rs
index f25d81f1c9a5..566b3581046d 100644
--- a/src/test/run-pass/rfcs/rfc-2126-extern-absolute-paths/basic.rs
+++ b/src/test/run-pass/rfcs/rfc-2126-extern-absolute-paths/basic.rs
@@ -4,9 +4,12 @@
 // compile-flags:--extern xcrate
 // edition:2018
 
+#![allow(unused_imports)]
+
 use xcrate::Z;
 
 fn f() {
+    use xcrate;
     use xcrate as ycrate;
     let s = xcrate::S;
     assert_eq!(format!("{:?}", s), "S");

From aec518addd7ab4624ccd57ea143395483dfc690a Mon Sep 17 00:00:00 2001
From: Yuki OKUSHI <huyuumi.dev@gmail.com>
Date: Sun, 31 Mar 2019 07:13:59 +0900
Subject: [PATCH 22/30] Fix test

---
 src/test/codegen/instrument-mcount.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/test/codegen/instrument-mcount.rs b/src/test/codegen/instrument-mcount.rs
index bd01556d986a..c72d09f7a03d 100644
--- a/src/test/codegen/instrument-mcount.rs
+++ b/src/test/codegen/instrument-mcount.rs
@@ -3,5 +3,5 @@
 
 #![crate_type = "lib"]
 
-// CHECK: attributes #{{.*}} "instrument-function-entry-inlined"="{{_*}}mcount" "no-frame-pointer-elim"="true"
+// CHECK: attributes #{{.*}} "instrument-function-entry-inlined"="{{.*}}mcount{{.*}}" "no-frame-pointer-elim"="true"
 pub fn foo() {}

From 70fa616a23b59e4b7b537e55f5b95ec3e963b2fd Mon Sep 17 00:00:00 2001
From: Jean-Marie Comets <jean.marie.comets@gmail.com>
Date: Sun, 31 Mar 2019 10:54:00 +0200
Subject: [PATCH 23/30] Stabilize refcell_replace_swap feature, closes #43570

---
 src/libcore/cell.rs           | 3 +--
 src/libcore/tests/lib.rs      | 1 -
 src/librustc/lib.rs           | 1 -
 src/librustc_typeck/lib.rs    | 1 -
 src/libsyntax/feature_gate.rs | 2 ++
 5 files changed, 3 insertions(+), 5 deletions(-)

diff --git a/src/libcore/cell.rs b/src/libcore/cell.rs
index 753f10e6a0ad..99169a6a259c 100644
--- a/src/libcore/cell.rs
+++ b/src/libcore/cell.rs
@@ -711,7 +711,6 @@ impl<T> RefCell<T> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(refcell_replace_swap)]
     /// use std::cell::RefCell;
     /// let cell = RefCell::new(5);
     /// let old_value = cell.replace_with(|&mut old| old + 1);
@@ -719,7 +718,7 @@ impl<T> RefCell<T> {
     /// assert_eq!(cell, RefCell::new(6));
     /// ```
     #[inline]
-    #[unstable(feature = "refcell_replace_swap", issue="43570")]
+    #[stable(feature = "refcell_replace_swap", since="1.35.0")]
     pub fn replace_with<F: FnOnce(&mut T) -> T>(&self, f: F) -> T {
         let mut_borrow = &mut *self.borrow_mut();
         let replacement = f(mut_borrow);
diff --git a/src/libcore/tests/lib.rs b/src/libcore/tests/lib.rs
index 2ed25a341021..5e0dbb7ab2f1 100644
--- a/src/libcore/tests/lib.rs
+++ b/src/libcore/tests/lib.rs
@@ -16,7 +16,6 @@
 #![feature(pattern)]
 #![feature(range_is_empty)]
 #![feature(raw)]
-#![feature(refcell_replace_swap)]
 #![feature(slice_patterns)]
 #![feature(sort_internals)]
 #![feature(specialization)]
diff --git a/src/librustc/lib.rs b/src/librustc/lib.rs
index e905c3688518..b87343b43c9f 100644
--- a/src/librustc/lib.rs
+++ b/src/librustc/lib.rs
@@ -45,7 +45,6 @@
 #![feature(proc_macro_internals)]
 #![feature(optin_builtin_traits)]
 #![feature(range_is_empty)]
-#![feature(refcell_replace_swap)]
 #![feature(rustc_diagnostic_macros)]
 #![feature(rustc_attrs)]
 #![feature(slice_patterns)]
diff --git a/src/librustc_typeck/lib.rs b/src/librustc_typeck/lib.rs
index cc90044573ce..1fa16352b867 100644
--- a/src/librustc_typeck/lib.rs
+++ b/src/librustc_typeck/lib.rs
@@ -64,7 +64,6 @@ This API is completely unstable and subject to change.
 #![feature(crate_visibility_modifier)]
 #![feature(exhaustive_patterns)]
 #![feature(nll)]
-#![feature(refcell_replace_swap)]
 #![feature(rustc_diagnostic_macros)]
 #![feature(slice_patterns)]
 #![feature(never_type)]
diff --git a/src/libsyntax/feature_gate.rs b/src/libsyntax/feature_gate.rs
index dcb55fb572f3..d53cfddaf8de 100644
--- a/src/libsyntax/feature_gate.rs
+++ b/src/libsyntax/feature_gate.rs
@@ -703,6 +703,8 @@ declare_features! (
     (accepted, extern_crate_self, "1.34.0", Some(56409), None),
     // support for arbitrary delimited token streams in non-macro attributes
     (accepted, unrestricted_attribute_tokens, "1.34.0", Some(55208), None),
+    // add replace and swap functions to RefCell
+    (accepted, refcell_replace_swap, "1.35.0", Some(43570), None),
 );
 
 // If you change this, please modify `src/doc/unstable-book` as well. You must

From ae6622da58d011e57489df7971a57f2cb6a6e926 Mon Sep 17 00:00:00 2001
From: Fabian Drinck <fabian.drinck@rwth-aachen.de>
Date: Sun, 31 Mar 2019 12:02:27 +0200
Subject: [PATCH 24/30] Add back missing import

---
 src/librustc_traits/lowering/environment.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/librustc_traits/lowering/environment.rs b/src/librustc_traits/lowering/environment.rs
index eb47892ea410..3570cb102460 100644
--- a/src/librustc_traits/lowering/environment.rs
+++ b/src/librustc_traits/lowering/environment.rs
@@ -164,7 +164,7 @@ crate fn environment<'a, 'tcx>(
     tcx: TyCtxt<'a, 'tcx, 'tcx>,
     def_id: DefId
 ) -> Environment<'tcx> {
-    use super::IntoFromEnvGoal;
+    use super::{Lower, IntoFromEnvGoal};
     use rustc::hir::{Node, TraitItemKind, ImplItemKind, ItemKind, ForeignItemKind};
 
     debug!("environment(def_id = {:?})", def_id);

From c1d5314bd3b628749491e4fe201b4c6916a53ce6 Mon Sep 17 00:00:00 2001
From: Fabian Drinck <fabian.drinck@rwth-aachen.de>
Date: Sun, 31 Mar 2019 14:11:46 +0200
Subject: [PATCH 25/30] Remove redundant import

---
 src/librustc_codegen_ssa/traits/type_.rs | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/librustc_codegen_ssa/traits/type_.rs b/src/librustc_codegen_ssa/traits/type_.rs
index 7fb2cb9d3936..efc18d401c08 100644
--- a/src/librustc_codegen_ssa/traits/type_.rs
+++ b/src/librustc_codegen_ssa/traits/type_.rs
@@ -77,7 +77,6 @@ pub trait DerivedTypeMethods<'tcx>: BaseTypeMethods<'tcx> + MiscMethods<'tcx> {
     }
 
     fn type_has_metadata(&self, ty: Ty<'tcx>) -> bool {
-        use syntax_pos::DUMMY_SP;
         if ty.is_sized(self.tcx().at(DUMMY_SP), ty::ParamEnv::reveal_all()) {
             return false;
         }

From c789a539a29b411b89411f8660d6ed2c2c4c4bbb Mon Sep 17 00:00:00 2001
From: Jean-Marie Comets <jean.marie.comets@gmail.com>
Date: Sun, 31 Mar 2019 14:50:06 +0200
Subject: [PATCH 26/30] refcell_replace_swap: remove feature gate & obsolete
 documentation item

---
 src/libcore/cell.rs           | 2 --
 src/libsyntax/feature_gate.rs | 2 --
 2 files changed, 4 deletions(-)

diff --git a/src/libcore/cell.rs b/src/libcore/cell.rs
index 99169a6a259c..f8c7ce101322 100644
--- a/src/libcore/cell.rs
+++ b/src/libcore/cell.rs
@@ -702,8 +702,6 @@ impl<T> RefCell<T> {
     /// Replaces the wrapped value with a new one computed from `f`, returning
     /// the old value, without deinitializing either one.
     ///
-    /// This function corresponds to [`std::mem::replace`](../mem/fn.replace.html).
-    ///
     /// # Panics
     ///
     /// Panics if the value is currently borrowed.
diff --git a/src/libsyntax/feature_gate.rs b/src/libsyntax/feature_gate.rs
index d53cfddaf8de..dcb55fb572f3 100644
--- a/src/libsyntax/feature_gate.rs
+++ b/src/libsyntax/feature_gate.rs
@@ -703,8 +703,6 @@ declare_features! (
     (accepted, extern_crate_self, "1.34.0", Some(56409), None),
     // support for arbitrary delimited token streams in non-macro attributes
     (accepted, unrestricted_attribute_tokens, "1.34.0", Some(55208), None),
-    // add replace and swap functions to RefCell
-    (accepted, refcell_replace_swap, "1.35.0", Some(43570), None),
 );
 
 // If you change this, please modify `src/doc/unstable-book` as well. You must

From 55b7efe29f333427bdc0d664a13171490ee615cc Mon Sep 17 00:00:00 2001
From: Jaro Fietz <jaro.fietz@gmx.de>
Date: Sun, 31 Mar 2019 15:20:10 +0200
Subject: [PATCH 27/30] match match match match match

---
 src/test/run-pass/weird-exprs.rs | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/src/test/run-pass/weird-exprs.rs b/src/test/run-pass/weird-exprs.rs
index 7ce7e29e8723..ae4de92ff748 100644
--- a/src/test/run-pass/weird-exprs.rs
+++ b/src/test/run-pass/weird-exprs.rs
@@ -127,6 +127,21 @@ fn punch_card() -> impl std::fmt::Debug {
     ..=.. ..=..    .. ..=..=..    ..=..=.. ..    .. ..=.. ..
 }
 
+fn r#match() {
+    let val = match match match match match () {
+        () => ()
+    } {
+        () => ()
+    } {
+        () => ()
+    } {
+        () => ()
+    } {
+        () => ()
+    };
+    assert_eq!(val, ());
+}
+
 pub fn main() {
     strange();
     funny();
@@ -142,4 +157,5 @@ pub fn main() {
     union();
     special_characters();
     punch_card();
+    r#match();
 }

From 7b26a43ae51fdb3c2ec7a3407e91add212c5754e Mon Sep 17 00:00:00 2001
From: Yuki OKUSHI <huyuumi.dev@gmail.com>
Date: Sun, 31 Mar 2019 23:17:49 +0900
Subject: [PATCH 28/30] Use `u{1}` instead of `01`

---
 src/librustc_target/spec/aarch64_unknown_linux_gnu.rs      | 2 +-
 src/librustc_target/spec/aarch64_unknown_linux_musl.rs     | 2 +-
 src/librustc_target/spec/arm_unknown_linux_gnueabi.rs      | 2 +-
 src/librustc_target/spec/arm_unknown_linux_gnueabihf.rs    | 2 +-
 src/librustc_target/spec/arm_unknown_linux_musleabi.rs     | 2 +-
 src/librustc_target/spec/arm_unknown_linux_musleabihf.rs   | 2 +-
 src/librustc_target/spec/armv4t_unknown_linux_gnueabi.rs   | 2 +-
 src/librustc_target/spec/armv5te_unknown_linux_gnueabi.rs  | 2 +-
 src/librustc_target/spec/armv5te_unknown_linux_musleabi.rs | 2 +-
 src/librustc_target/spec/armv6_unknown_freebsd.rs          | 2 +-
 src/librustc_target/spec/armv7_unknown_cloudabi_eabihf.rs  | 2 +-
 src/librustc_target/spec/armv7_unknown_freebsd.rs          | 2 +-
 src/librustc_target/spec/armv7_unknown_linux_gnueabihf.rs  | 2 +-
 src/librustc_target/spec/armv7_unknown_linux_musleabihf.rs | 2 +-
 src/librustc_target/spec/i686_apple_darwin.rs              | 2 +-
 src/librustc_target/spec/x86_64_apple_darwin.rs            | 2 +-
 16 files changed, 16 insertions(+), 16 deletions(-)

diff --git a/src/librustc_target/spec/aarch64_unknown_linux_gnu.rs b/src/librustc_target/spec/aarch64_unknown_linux_gnu.rs
index 59a285736412..b9d36c09f163 100644
--- a/src/librustc_target/spec/aarch64_unknown_linux_gnu.rs
+++ b/src/librustc_target/spec/aarch64_unknown_linux_gnu.rs
@@ -17,7 +17,7 @@ pub fn target() -> TargetResult {
         linker_flavor: LinkerFlavor::Gcc,
         options: TargetOptions {
             abi_blacklist: super::arm_base::abi_blacklist(),
-            target_mcount: "\01_mcount".to_string(),
+            target_mcount: "\u{1}_mcount".to_string(),
             .. base
         },
     })
diff --git a/src/librustc_target/spec/aarch64_unknown_linux_musl.rs b/src/librustc_target/spec/aarch64_unknown_linux_musl.rs
index 781b1322f5ac..968e82ca39fb 100644
--- a/src/librustc_target/spec/aarch64_unknown_linux_musl.rs
+++ b/src/librustc_target/spec/aarch64_unknown_linux_musl.rs
@@ -17,7 +17,7 @@ pub fn target() -> TargetResult {
         linker_flavor: LinkerFlavor::Gcc,
         options: TargetOptions {
             abi_blacklist: super::arm_base::abi_blacklist(),
-            target_mcount: "\01_mcount".to_string(),
+            target_mcount: "\u{1}_mcount".to_string(),
             .. base
         },
     })
diff --git a/src/librustc_target/spec/arm_unknown_linux_gnueabi.rs b/src/librustc_target/spec/arm_unknown_linux_gnueabi.rs
index 1173d18634e1..2f835420148f 100644
--- a/src/librustc_target/spec/arm_unknown_linux_gnueabi.rs
+++ b/src/librustc_target/spec/arm_unknown_linux_gnueabi.rs
@@ -18,7 +18,7 @@ pub fn target() -> TargetResult {
         options: TargetOptions {
             features: "+strict-align,+v6".to_string(),
             abi_blacklist: super::arm_base::abi_blacklist(),
-            target_mcount: "\01__gnu_mcount_nc".to_string(),
+            target_mcount: "\u{1}__gnu_mcount_nc".to_string(),
             .. base
         },
     })
diff --git a/src/librustc_target/spec/arm_unknown_linux_gnueabihf.rs b/src/librustc_target/spec/arm_unknown_linux_gnueabihf.rs
index 6fc7c46be3b1..cd4b2e1c9225 100644
--- a/src/librustc_target/spec/arm_unknown_linux_gnueabihf.rs
+++ b/src/librustc_target/spec/arm_unknown_linux_gnueabihf.rs
@@ -18,7 +18,7 @@ pub fn target() -> TargetResult {
         options: TargetOptions {
             features: "+strict-align,+v6,+vfp2".to_string(),
             abi_blacklist: super::arm_base::abi_blacklist(),
-            target_mcount: "\01__gnu_mcount_nc".to_string(),
+            target_mcount: "\u{1}__gnu_mcount_nc".to_string(),
             .. base
         }
     })
diff --git a/src/librustc_target/spec/arm_unknown_linux_musleabi.rs b/src/librustc_target/spec/arm_unknown_linux_musleabi.rs
index 7a2a4e85e4a1..606c3f190603 100644
--- a/src/librustc_target/spec/arm_unknown_linux_musleabi.rs
+++ b/src/librustc_target/spec/arm_unknown_linux_musleabi.rs
@@ -23,7 +23,7 @@ pub fn target() -> TargetResult {
         linker_flavor: LinkerFlavor::Gcc,
         options: TargetOptions {
             abi_blacklist: super::arm_base::abi_blacklist(),
-            target_mcount: "\01mcount".to_string(),
+            target_mcount: "\u{1}mcount".to_string(),
             .. base
         },
     })
diff --git a/src/librustc_target/spec/arm_unknown_linux_musleabihf.rs b/src/librustc_target/spec/arm_unknown_linux_musleabihf.rs
index b7aa1952cb0b..d22156bc328e 100644
--- a/src/librustc_target/spec/arm_unknown_linux_musleabihf.rs
+++ b/src/librustc_target/spec/arm_unknown_linux_musleabihf.rs
@@ -23,7 +23,7 @@ pub fn target() -> TargetResult {
         linker_flavor: LinkerFlavor::Gcc,
         options: TargetOptions {
             abi_blacklist: super::arm_base::abi_blacklist(),
-            target_mcount: "\01mcount".to_string(),
+            target_mcount: "\u{1}mcount".to_string(),
             .. base
         },
     })
diff --git a/src/librustc_target/spec/armv4t_unknown_linux_gnueabi.rs b/src/librustc_target/spec/armv4t_unknown_linux_gnueabi.rs
index 59c15f1610de..e7da24843cc0 100644
--- a/src/librustc_target/spec/armv4t_unknown_linux_gnueabi.rs
+++ b/src/librustc_target/spec/armv4t_unknown_linux_gnueabi.rs
@@ -19,7 +19,7 @@ pub fn target() -> TargetResult {
             // Atomic operations provided by compiler-builtins
             max_atomic_width: Some(32),
             abi_blacklist: super::arm_base::abi_blacklist(),
-            target_mcount: "\01__gnu_mcount_nc".to_string(),
+            target_mcount: "\u{1}__gnu_mcount_nc".to_string(),
             .. base
         }
     })
diff --git a/src/librustc_target/spec/armv5te_unknown_linux_gnueabi.rs b/src/librustc_target/spec/armv5te_unknown_linux_gnueabi.rs
index a1a61a69d052..ea586f42c269 100644
--- a/src/librustc_target/spec/armv5te_unknown_linux_gnueabi.rs
+++ b/src/librustc_target/spec/armv5te_unknown_linux_gnueabi.rs
@@ -19,7 +19,7 @@ pub fn target() -> TargetResult {
             // Atomic operations provided by compiler-builtins
             max_atomic_width: Some(32),
             abi_blacklist: super::arm_base::abi_blacklist(),
-            target_mcount: "\01__gnu_mcount_nc".to_string(),
+            target_mcount: "\u{1}__gnu_mcount_nc".to_string(),
             .. base
         }
     })
diff --git a/src/librustc_target/spec/armv5te_unknown_linux_musleabi.rs b/src/librustc_target/spec/armv5te_unknown_linux_musleabi.rs
index 9b44a54715e7..dae5c8c3d750 100644
--- a/src/librustc_target/spec/armv5te_unknown_linux_musleabi.rs
+++ b/src/librustc_target/spec/armv5te_unknown_linux_musleabi.rs
@@ -22,7 +22,7 @@ pub fn target() -> TargetResult {
             // Atomic operations provided by compiler-builtins
             max_atomic_width: Some(32),
             abi_blacklist: super::arm_base::abi_blacklist(),
-            target_mcount: "\01mcount".to_string(),
+            target_mcount: "\u{1}mcount".to_string(),
             .. base
         }
     })
diff --git a/src/librustc_target/spec/armv6_unknown_freebsd.rs b/src/librustc_target/spec/armv6_unknown_freebsd.rs
index e706c8281d23..a90590a39e75 100644
--- a/src/librustc_target/spec/armv6_unknown_freebsd.rs
+++ b/src/librustc_target/spec/armv6_unknown_freebsd.rs
@@ -18,7 +18,7 @@ pub fn target() -> TargetResult {
             features: "+v6,+vfp2".to_string(),
             max_atomic_width: Some(64),
             abi_blacklist: super::arm_base::abi_blacklist(),
-            target_mcount: "\01__gnu_mcount_nc".to_string(),
+            target_mcount: "\u{1}__gnu_mcount_nc".to_string(),
             .. base
         }
     })
diff --git a/src/librustc_target/spec/armv7_unknown_cloudabi_eabihf.rs b/src/librustc_target/spec/armv7_unknown_cloudabi_eabihf.rs
index 70d4985ab860..c03f4b544ed0 100644
--- a/src/librustc_target/spec/armv7_unknown_cloudabi_eabihf.rs
+++ b/src/librustc_target/spec/armv7_unknown_cloudabi_eabihf.rs
@@ -20,7 +20,7 @@ pub fn target() -> TargetResult {
         target_vendor: "unknown".to_string(),
         linker_flavor: LinkerFlavor::Gcc,
         options: TargetOptions {
-            target_mcount: "\01mcount".to_string(),
+            target_mcount: "\u{1}mcount".to_string(),
             .. base
         },
     })
diff --git a/src/librustc_target/spec/armv7_unknown_freebsd.rs b/src/librustc_target/spec/armv7_unknown_freebsd.rs
index 0f9ee5d44a95..ca7ab474bef8 100644
--- a/src/librustc_target/spec/armv7_unknown_freebsd.rs
+++ b/src/librustc_target/spec/armv7_unknown_freebsd.rs
@@ -18,7 +18,7 @@ pub fn target() -> TargetResult {
             features: "+v7,+vfp3,+d16,+thumb2,-neon".to_string(),
             max_atomic_width: Some(64),
             abi_blacklist: super::arm_base::abi_blacklist(),
-            target_mcount: "\01__gnu_mcount_nc".to_string(),
+            target_mcount: "\u{1}__gnu_mcount_nc".to_string(),
             .. base
         }
     })
diff --git a/src/librustc_target/spec/armv7_unknown_linux_gnueabihf.rs b/src/librustc_target/spec/armv7_unknown_linux_gnueabihf.rs
index afba6f608ee0..f0952cccb208 100644
--- a/src/librustc_target/spec/armv7_unknown_linux_gnueabihf.rs
+++ b/src/librustc_target/spec/armv7_unknown_linux_gnueabihf.rs
@@ -23,7 +23,7 @@ pub fn target() -> TargetResult {
             cpu: "generic".to_string(),
             max_atomic_width: Some(64),
             abi_blacklist: super::arm_base::abi_blacklist(),
-            target_mcount: "\01__gnu_mcount_nc".to_string(),
+            target_mcount: "\u{1}__gnu_mcount_nc".to_string(),
             .. base
         }
     })
diff --git a/src/librustc_target/spec/armv7_unknown_linux_musleabihf.rs b/src/librustc_target/spec/armv7_unknown_linux_musleabihf.rs
index 516d0401adf5..a9974f6b80c9 100644
--- a/src/librustc_target/spec/armv7_unknown_linux_musleabihf.rs
+++ b/src/librustc_target/spec/armv7_unknown_linux_musleabihf.rs
@@ -26,7 +26,7 @@ pub fn target() -> TargetResult {
             cpu: "generic".to_string(),
             max_atomic_width: Some(64),
             abi_blacklist: super::arm_base::abi_blacklist(),
-            target_mcount: "\01mcount".to_string(),
+            target_mcount: "\u{1}mcount".to_string(),
             .. base
         }
     })
diff --git a/src/librustc_target/spec/i686_apple_darwin.rs b/src/librustc_target/spec/i686_apple_darwin.rs
index a82ff33ce1db..58c59cc87284 100644
--- a/src/librustc_target/spec/i686_apple_darwin.rs
+++ b/src/librustc_target/spec/i686_apple_darwin.rs
@@ -20,7 +20,7 @@ pub fn target() -> TargetResult {
         target_vendor: "apple".to_string(),
         linker_flavor: LinkerFlavor::Gcc,
         options: TargetOptions {
-            target_mcount: "\01mcount".to_string(),
+            target_mcount: "\u{1}mcount".to_string(),
             .. base
         },
     })
diff --git a/src/librustc_target/spec/x86_64_apple_darwin.rs b/src/librustc_target/spec/x86_64_apple_darwin.rs
index fecc20c01c5e..c54181741b3c 100644
--- a/src/librustc_target/spec/x86_64_apple_darwin.rs
+++ b/src/librustc_target/spec/x86_64_apple_darwin.rs
@@ -20,7 +20,7 @@ pub fn target() -> TargetResult {
         target_vendor: "apple".to_string(),
         linker_flavor: LinkerFlavor::Gcc,
         options: TargetOptions {
-            target_mcount: "\01mcount".to_string(),
+            target_mcount: "\u{1}mcount".to_string(),
             .. base
         },
     })

From c056a79f354b9b85cfeb9a6d32632edea4719263 Mon Sep 17 00:00:00 2001
From: Aaron Power <theaaronepower@gmail.com>
Date: Sun, 31 Mar 2019 16:54:05 +0200
Subject: [PATCH 29/30] Remove #[doc(hidden)] from Error::type_id

---
 src/libstd/error.rs | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/libstd/error.rs b/src/libstd/error.rs
index 3eb289501cb0..6c80a23e2e04 100644
--- a/src/libstd/error.rs
+++ b/src/libstd/error.rs
@@ -197,7 +197,6 @@ pub trait Error: Debug + Display {
     fn source(&self) -> Option<&(dyn Error + 'static)> { None }
 
     /// Gets the `TypeId` of `self`
-    #[doc(hidden)]
     #[stable(feature = "error_type_id", since = "1.34.0")]
     fn type_id(&self) -> TypeId where Self: 'static {
         TypeId::of::<Self>()

From 07021e07edf30384203b43024f5bc81ac84a9574 Mon Sep 17 00:00:00 2001
From: Taiki Endo <te316e89@gmail.com>
Date: Mon, 1 Apr 2019 00:00:43 +0900
Subject: [PATCH 30/30] Allow closure to unsafe fn coercion

---
 src/librustc/middle/expr_use_visitor.rs              |  2 +-
 src/librustc/middle/mem_categorization.rs            |  2 +-
 src/librustc/mir/mod.rs                              |  5 +++--
 src/librustc/ty/adjustment.rs                        |  5 +++--
 src/librustc/ty/context.rs                           |  8 ++++++--
 src/librustc/ty/structural_impls.rs                  |  6 +++---
 src/librustc_codegen_ssa/mir/rvalue.rs               |  2 +-
 src/librustc_mir/borrow_check/nll/type_check/mod.rs  |  4 ++--
 src/librustc_mir/build/expr/as_rvalue.rs             |  4 ++--
 src/librustc_mir/hair/cx/expr.rs                     |  4 ++--
 src/librustc_mir/hair/mod.rs                         |  1 +
 src/librustc_mir/interpret/cast.rs                   |  2 +-
 src/librustc_mir/monomorphize/collector.rs           |  2 +-
 src/librustc_mir/transform/qualify_consts.rs         |  2 +-
 src/librustc_mir/transform/qualify_min_const_fn.rs   |  2 +-
 src/librustc_passes/rvalue_promotion.rs              |  2 +-
 src/librustc_typeck/check/coercion.rs                | 12 ++++++++----
 .../coerce-unsafe-closure-to-unsafe-fn-ptr.rs        |  5 +++++
 src/test/run-pass/typeck-closure-to-unsafe-fn-ptr.rs |  7 +++++++
 19 files changed, 50 insertions(+), 27 deletions(-)
 create mode 100644 src/test/compile-fail/coerce-unsafe-closure-to-unsafe-fn-ptr.rs
 create mode 100644 src/test/run-pass/typeck-closure-to-unsafe-fn-ptr.rs

diff --git a/src/librustc/middle/expr_use_visitor.rs b/src/librustc/middle/expr_use_visitor.rs
index 01e57273e54a..4f630fe9a391 100644
--- a/src/librustc/middle/expr_use_visitor.rs
+++ b/src/librustc/middle/expr_use_visitor.rs
@@ -707,7 +707,7 @@ impl<'a, 'gcx, 'tcx> ExprUseVisitor<'a, 'gcx, 'tcx> {
                 adjustment::Adjust::NeverToAny |
                 adjustment::Adjust::ReifyFnPointer |
                 adjustment::Adjust::UnsafeFnPointer |
-                adjustment::Adjust::ClosureFnPointer |
+                adjustment::Adjust::ClosureFnPointer(_) |
                 adjustment::Adjust::MutToConstPointer |
                 adjustment::Adjust::Unsize => {
                     // Creating a closure/fn-pointer or unsizing consumes
diff --git a/src/librustc/middle/mem_categorization.rs b/src/librustc/middle/mem_categorization.rs
index 4b169dea06c7..1a3fef18404e 100644
--- a/src/librustc/middle/mem_categorization.rs
+++ b/src/librustc/middle/mem_categorization.rs
@@ -621,7 +621,7 @@ impl<'a, 'gcx, 'tcx> MemCategorizationContext<'a, 'gcx, 'tcx> {
             adjustment::Adjust::NeverToAny |
             adjustment::Adjust::ReifyFnPointer |
             adjustment::Adjust::UnsafeFnPointer |
-            adjustment::Adjust::ClosureFnPointer |
+            adjustment::Adjust::ClosureFnPointer(_) |
             adjustment::Adjust::MutToConstPointer |
             adjustment::Adjust::Borrow(_) |
             adjustment::Adjust::Unsize => {
diff --git a/src/librustc/mir/mod.rs b/src/librustc/mir/mod.rs
index d35ee1e57d5c..7b419e306db6 100644
--- a/src/librustc/mir/mod.rs
+++ b/src/librustc/mir/mod.rs
@@ -2247,8 +2247,9 @@ pub enum CastKind {
     /// Converts unique, zero-sized type for a fn to fn()
     ReifyFnPointer,
 
-    /// Converts non capturing closure to fn()
-    ClosureFnPointer,
+    /// Converts non capturing closure to fn() or unsafe fn().
+    /// It cannot convert a closure that requires unsafe.
+    ClosureFnPointer(hir::Unsafety),
 
     /// Converts safe fn() to unsafe fn()
     UnsafeFnPointer,
diff --git a/src/librustc/ty/adjustment.rs b/src/librustc/ty/adjustment.rs
index f9149ce0f6e6..c2ef08c4c40f 100644
--- a/src/librustc/ty/adjustment.rs
+++ b/src/librustc/ty/adjustment.rs
@@ -62,8 +62,9 @@ pub enum Adjust<'tcx> {
     /// Go from a safe fn pointer to an unsafe fn pointer.
     UnsafeFnPointer,
 
-    /// Go from a non-capturing closure to an fn pointer.
-    ClosureFnPointer,
+    /// Go from a non-capturing closure to an fn pointer or an unsafe fn pointer.
+    /// It cannot convert a closure that requires unsafe.
+    ClosureFnPointer(hir::Unsafety),
 
     /// Go from a mut raw pointer to a const raw pointer.
     MutToConstPointer,
diff --git a/src/librustc/ty/context.rs b/src/librustc/ty/context.rs
index ea003ba1ac70..77330c7a9d1b 100644
--- a/src/librustc/ty/context.rs
+++ b/src/librustc/ty/context.rs
@@ -2441,7 +2441,11 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
     /// type with the same signature. Detuples and so forth -- so
     /// e.g., if we have a sig with `Fn<(u32, i32)>` then you would get
     /// a `fn(u32, i32)`.
-    pub fn coerce_closure_fn_ty(self, sig: PolyFnSig<'tcx>) -> Ty<'tcx> {
+    /// `unsafety` determines the unsafety of the `fn` type. If you pass
+    /// `hir::Unsafety::Unsafe` in the previous example, then you would get
+    /// an `unsafe fn (u32, i32)`.
+    /// It cannot convert a closure that requires unsafe.
+    pub fn coerce_closure_fn_ty(self, sig: PolyFnSig<'tcx>, unsafety: hir::Unsafety) -> Ty<'tcx> {
         let converted_sig = sig.map_bound(|s| {
             let params_iter = match s.inputs()[0].sty {
                 ty::Tuple(params) => {
@@ -2453,7 +2457,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
                 params_iter,
                 s.output(),
                 s.c_variadic,
-                hir::Unsafety::Normal,
+                unsafety,
                 abi::Abi::Rust,
             )
         });
diff --git a/src/librustc/ty/structural_impls.rs b/src/librustc/ty/structural_impls.rs
index cbdda7326928..4f1fda3f4e53 100644
--- a/src/librustc/ty/structural_impls.rs
+++ b/src/librustc/ty/structural_impls.rs
@@ -630,8 +630,8 @@ impl<'a, 'tcx> Lift<'tcx> for ty::adjustment::Adjust<'a> {
                 Some(ty::adjustment::Adjust::ReifyFnPointer),
             ty::adjustment::Adjust::UnsafeFnPointer =>
                 Some(ty::adjustment::Adjust::UnsafeFnPointer),
-            ty::adjustment::Adjust::ClosureFnPointer =>
-                Some(ty::adjustment::Adjust::ClosureFnPointer),
+            ty::adjustment::Adjust::ClosureFnPointer(unsafety) =>
+                Some(ty::adjustment::Adjust::ClosureFnPointer(unsafety)),
             ty::adjustment::Adjust::MutToConstPointer =>
                 Some(ty::adjustment::Adjust::MutToConstPointer),
             ty::adjustment::Adjust::Unsize =>
@@ -1187,7 +1187,7 @@ EnumTypeFoldableImpl! {
         (ty::adjustment::Adjust::NeverToAny),
         (ty::adjustment::Adjust::ReifyFnPointer),
         (ty::adjustment::Adjust::UnsafeFnPointer),
-        (ty::adjustment::Adjust::ClosureFnPointer),
+        (ty::adjustment::Adjust::ClosureFnPointer)(a),
         (ty::adjustment::Adjust::MutToConstPointer),
         (ty::adjustment::Adjust::Unsize),
         (ty::adjustment::Adjust::Deref)(a),
diff --git a/src/librustc_codegen_ssa/mir/rvalue.rs b/src/librustc_codegen_ssa/mir/rvalue.rs
index 7a31c5b3950e..5e8723029651 100644
--- a/src/librustc_codegen_ssa/mir/rvalue.rs
+++ b/src/librustc_codegen_ssa/mir/rvalue.rs
@@ -193,7 +193,7 @@ impl<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                             }
                         }
                     }
-                    mir::CastKind::ClosureFnPointer => {
+                    mir::CastKind::ClosureFnPointer(_) => {
                         match operand.layout.ty.sty {
                             ty::Closure(def_id, substs) => {
                                 let instance = monomorphize::resolve_closure(
diff --git a/src/librustc_mir/borrow_check/nll/type_check/mod.rs b/src/librustc_mir/borrow_check/nll/type_check/mod.rs
index a3561515aaa3..3b559b28f123 100644
--- a/src/librustc_mir/borrow_check/nll/type_check/mod.rs
+++ b/src/librustc_mir/borrow_check/nll/type_check/mod.rs
@@ -1999,14 +1999,14 @@ impl<'a, 'gcx, 'tcx> TypeChecker<'a, 'gcx, 'tcx> {
                         }
                     }
 
-                    CastKind::ClosureFnPointer => {
+                    CastKind::ClosureFnPointer(unsafety) => {
                         let sig = match op.ty(mir, tcx).sty {
                             ty::Closure(def_id, substs) => {
                                 substs.closure_sig_ty(def_id, tcx).fn_sig(tcx)
                             }
                             _ => bug!(),
                         };
-                        let ty_fn_ptr_from = tcx.coerce_closure_fn_ty(sig);
+                        let ty_fn_ptr_from = tcx.coerce_closure_fn_ty(sig, *unsafety);
 
                         if let Err(terr) = self.eq_types(
                             ty_fn_ptr_from,
diff --git a/src/librustc_mir/build/expr/as_rvalue.rs b/src/librustc_mir/build/expr/as_rvalue.rs
index 9e12a7e6fa93..84f74484e606 100644
--- a/src/librustc_mir/build/expr/as_rvalue.rs
+++ b/src/librustc_mir/build/expr/as_rvalue.rs
@@ -162,9 +162,9 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> {
                 let source = unpack!(block = this.as_operand(block, scope, source));
                 block.and(Rvalue::Cast(CastKind::UnsafeFnPointer, source, expr.ty))
             }
-            ExprKind::ClosureFnPointer { source } => {
+            ExprKind::ClosureFnPointer { source, unsafety } => {
                 let source = unpack!(block = this.as_operand(block, scope, source));
-                block.and(Rvalue::Cast(CastKind::ClosureFnPointer, source, expr.ty))
+                block.and(Rvalue::Cast(CastKind::ClosureFnPointer(unsafety), source, expr.ty))
             }
             ExprKind::MutToConstPointer { source } => {
                 let source = unpack!(block = this.as_operand(block, scope, source));
diff --git a/src/librustc_mir/hair/cx/expr.rs b/src/librustc_mir/hair/cx/expr.rs
index e4f92f81e9ff..91113dc2271b 100644
--- a/src/librustc_mir/hair/cx/expr.rs
+++ b/src/librustc_mir/hair/cx/expr.rs
@@ -81,8 +81,8 @@ fn apply_adjustment<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
         Adjust::UnsafeFnPointer => {
             ExprKind::UnsafeFnPointer { source: expr.to_ref() }
         }
-        Adjust::ClosureFnPointer => {
-            ExprKind::ClosureFnPointer { source: expr.to_ref() }
+        Adjust::ClosureFnPointer(unsafety) => {
+            ExprKind::ClosureFnPointer { source: expr.to_ref(), unsafety }
         }
         Adjust::NeverToAny => {
             ExprKind::NeverToAny { source: expr.to_ref() }
diff --git a/src/librustc_mir/hair/mod.rs b/src/librustc_mir/hair/mod.rs
index 3a38876bb680..a661649db0fd 100644
--- a/src/librustc_mir/hair/mod.rs
+++ b/src/librustc_mir/hair/mod.rs
@@ -185,6 +185,7 @@ pub enum ExprKind<'tcx> {
     },
     ClosureFnPointer {
         source: ExprRef<'tcx>,
+        unsafety: hir::Unsafety,
     },
     UnsafeFnPointer {
         source: ExprRef<'tcx>,
diff --git a/src/librustc_mir/interpret/cast.rs b/src/librustc_mir/interpret/cast.rs
index 003c2182d0b4..b60cc99e51c1 100644
--- a/src/librustc_mir/interpret/cast.rs
+++ b/src/librustc_mir/interpret/cast.rs
@@ -105,7 +105,7 @@ impl<'a, 'mir, 'tcx, M: Machine<'a, 'mir, 'tcx>> InterpretCx<'a, 'mir, 'tcx, M>
                 }
             }
 
-            ClosureFnPointer => {
+            ClosureFnPointer(_) => {
                 // The src operand does not matter, just its type
                 match src.layout.ty.sty {
                     ty::Closure(def_id, substs) => {
diff --git a/src/librustc_mir/monomorphize/collector.rs b/src/librustc_mir/monomorphize/collector.rs
index 0e8ab2ba2a5a..45b346b64136 100644
--- a/src/librustc_mir/monomorphize/collector.rs
+++ b/src/librustc_mir/monomorphize/collector.rs
@@ -563,7 +563,7 @@ impl<'a, 'tcx> MirVisitor<'tcx> for MirNeighborCollector<'a, 'tcx> {
                 );
                 visit_fn_use(self.tcx, fn_ty, false, &mut self.output);
             }
-            mir::Rvalue::Cast(mir::CastKind::ClosureFnPointer, ref operand, _) => {
+            mir::Rvalue::Cast(mir::CastKind::ClosureFnPointer(_), ref operand, _) => {
                 let source_ty = operand.ty(self.mir, self.tcx);
                 let source_ty = self.tcx.subst_and_normalize_erasing_regions(
                     self.param_substs,
diff --git a/src/librustc_mir/transform/qualify_consts.rs b/src/librustc_mir/transform/qualify_consts.rs
index 0b9ad85e6b1c..9bd5fce31f1a 100644
--- a/src/librustc_mir/transform/qualify_consts.rs
+++ b/src/librustc_mir/transform/qualify_consts.rs
@@ -1105,7 +1105,7 @@ impl<'a, 'tcx> Visitor<'tcx> for Checker<'a, 'tcx> {
             Rvalue::CheckedBinaryOp(..) |
             Rvalue::Cast(CastKind::ReifyFnPointer, ..) |
             Rvalue::Cast(CastKind::UnsafeFnPointer, ..) |
-            Rvalue::Cast(CastKind::ClosureFnPointer, ..) |
+            Rvalue::Cast(CastKind::ClosureFnPointer(_), ..) |
             Rvalue::Cast(CastKind::Unsize, ..) |
             Rvalue::Cast(CastKind::MutToConstPointer, ..) |
             Rvalue::Discriminant(..) |
diff --git a/src/librustc_mir/transform/qualify_min_const_fn.rs b/src/librustc_mir/transform/qualify_min_const_fn.rs
index 8742c5d759c8..87459571b529 100644
--- a/src/librustc_mir/transform/qualify_min_const_fn.rs
+++ b/src/librustc_mir/transform/qualify_min_const_fn.rs
@@ -156,7 +156,7 @@ fn check_rvalue(
             check_operand(tcx, mir, operand, span)
         }
         Rvalue::Cast(CastKind::UnsafeFnPointer, _, _) |
-        Rvalue::Cast(CastKind::ClosureFnPointer, _, _) |
+        Rvalue::Cast(CastKind::ClosureFnPointer(_), _, _) |
         Rvalue::Cast(CastKind::ReifyFnPointer, _, _) => Err((
             span,
             "function pointer casts are not allowed in const fn".into(),
diff --git a/src/librustc_passes/rvalue_promotion.rs b/src/librustc_passes/rvalue_promotion.rs
index a0a0d7be1b95..7c37c38f2d74 100644
--- a/src/librustc_passes/rvalue_promotion.rs
+++ b/src/librustc_passes/rvalue_promotion.rs
@@ -586,7 +586,7 @@ fn check_adjustments<'a, 'tcx>(
             Adjust::NeverToAny |
             Adjust::ReifyFnPointer |
             Adjust::UnsafeFnPointer |
-            Adjust::ClosureFnPointer |
+            Adjust::ClosureFnPointer(_) |
             Adjust::MutToConstPointer |
             Adjust::Borrow(_) |
             Adjust::Unsize => {}
diff --git a/src/librustc_typeck/check/coercion.rs b/src/librustc_typeck/check/coercion.rs
index ac8b639edbfa..c470bc09e8cd 100644
--- a/src/librustc_typeck/check/coercion.rs
+++ b/src/librustc_typeck/check/coercion.rs
@@ -225,7 +225,8 @@ impl<'f, 'gcx, 'tcx> Coerce<'f, 'gcx, 'tcx> {
             }
             ty::Closure(def_id_a, substs_a) => {
                 // Non-capturing closures are coercible to
-                // function pointers
+                // function pointers or unsafe function pointers.
+                // It cannot convert closures that require unsafe.
                 self.coerce_closure_to_fn(a, def_id_a, substs_a, b)
             }
             _ => {
@@ -714,16 +715,19 @@ impl<'f, 'gcx, 'tcx> Coerce<'f, 'gcx, 'tcx> {
 
         let hir_id_a = self.tcx.hir().as_local_hir_id(def_id_a).unwrap();
         match b.sty {
-            ty::FnPtr(_) if self.tcx.with_freevars(hir_id_a, |v| v.is_empty()) => {
+            ty::FnPtr(fn_ty) if self.tcx.with_freevars(hir_id_a, |v| v.is_empty()) => {
                 // We coerce the closure, which has fn type
                 //     `extern "rust-call" fn((arg0,arg1,...)) -> _`
                 // to
                 //     `fn(arg0,arg1,...) -> _`
+                // or
+                //     `unsafe fn(arg0,arg1,...) -> _`
                 let sig = self.closure_sig(def_id_a, substs_a);
-                let pointer_ty = self.tcx.coerce_closure_fn_ty(sig);
+                let unsafety = fn_ty.unsafety();
+                let pointer_ty = self.tcx.coerce_closure_fn_ty(sig, unsafety);
                 debug!("coerce_closure_to_fn(a={:?}, b={:?}, pty={:?})",
                        a, b, pointer_ty);
-                self.unify_and(pointer_ty, b, simple(Adjust::ClosureFnPointer))
+                self.unify_and(pointer_ty, b, simple(Adjust::ClosureFnPointer(unsafety)))
             }
             _ => self.unify_and(a, b, identity),
         }
diff --git a/src/test/compile-fail/coerce-unsafe-closure-to-unsafe-fn-ptr.rs b/src/test/compile-fail/coerce-unsafe-closure-to-unsafe-fn-ptr.rs
new file mode 100644
index 000000000000..36777693faba
--- /dev/null
+++ b/src/test/compile-fail/coerce-unsafe-closure-to-unsafe-fn-ptr.rs
@@ -0,0 +1,5 @@
+fn main() {
+    let _: unsafe fn() = || { ::std::pin::Pin::new_unchecked(&0_u8); };
+    //~^ ERROR E0133
+    let _: unsafe fn() = || unsafe { ::std::pin::Pin::new_unchecked(&0_u8); }; // OK
+}
diff --git a/src/test/run-pass/typeck-closure-to-unsafe-fn-ptr.rs b/src/test/run-pass/typeck-closure-to-unsafe-fn-ptr.rs
new file mode 100644
index 000000000000..fe15b912d602
--- /dev/null
+++ b/src/test/run-pass/typeck-closure-to-unsafe-fn-ptr.rs
@@ -0,0 +1,7 @@
+unsafe fn call_unsafe(func: unsafe fn() -> ()) -> () {
+    func()
+}
+
+pub fn main() {
+    unsafe { call_unsafe(|| {}); }
+}