Auto merge of #47276 - kennytm:rollup, r=kennytm

Rollup of 10 pull requests

- Successful merges: #47210, #47233, #47246, #47254, #47256, #47258, #47259, #47263, #47270, #47272
- Failed merges: #47248

src/libcore/fmt/mod.rs

@@ -83,9 +83,12 @@ pub type Result = result::Result<(), Error>;
 /// some other means.
 ///
 /// An important thing to remember is that the type `fmt::Error` should not be
-/// confused with `std::io::Error` or `std::error::Error`, which you may also
+/// confused with [`std::io::Error`] or [`std::error::Error`], which you may also
 /// have in scope.
 ///
+/// [`std::io::Error`]: ../../std/io/struct.Error.html
+/// [`std::error::Error`]: ../../std/error/trait.Error.html
+///
 /// # Examples
 ///
 /// ```rust

src/librustc/middle/dead.rs

@@ -50,7 +50,7 @@ struct MarkSymbolVisitor<'a, 'tcx: 'a> {
     tcx: TyCtxt<'a, 'tcx, 'tcx>,
     tables: &'a ty::TypeckTables<'tcx>,
     live_symbols: Box<FxHashSet<ast::NodeId>>,
-    struct_has_extern_repr: bool,
+    repr_has_repr_c: bool,
     in_pat: bool,
     inherited_pub_visibility: bool,
     ignore_variant_stack: Vec<DefId>,
@@ -102,7 +102,7 @@ impl<'a, 'tcx> MarkSymbolVisitor<'a, 'tcx> {
     fn handle_field_access(&mut self, lhs: &hir::Expr, name: ast::Name) {
         match self.tables.expr_ty_adjusted(lhs).sty {
             ty::TyAdt(def, _) => {
-                self.insert_def_id(def.struct_variant().field_named(name).did);
+                self.insert_def_id(def.non_enum_variant().field_named(name).did);
             }
             _ => span_bug!(lhs.span, "named field access on non-ADT"),
         }
@@ -111,7 +111,7 @@ impl<'a, 'tcx> MarkSymbolVisitor<'a, 'tcx> {
     fn handle_tup_field_access(&mut self, lhs: &hir::Expr, idx: usize) {
         match self.tables.expr_ty_adjusted(lhs).sty {
             ty::TyAdt(def, _) => {
-                self.insert_def_id(def.struct_variant().fields[idx].did);
+                self.insert_def_id(def.non_enum_variant().fields[idx].did);
             }
             ty::TyTuple(..) => {}
             _ => span_bug!(lhs.span, "numeric field access on non-ADT"),
@@ -149,8 +149,8 @@ impl<'a, 'tcx> MarkSymbolVisitor<'a, 'tcx> {
     }
 
     fn visit_node(&mut self, node: &hir_map::Node<'tcx>) {
-        let had_extern_repr = self.struct_has_extern_repr;
-        self.struct_has_extern_repr = false;
+        let had_repr_c = self.repr_has_repr_c;
+        self.repr_has_repr_c = false;
         let had_inherited_pub_visibility = self.inherited_pub_visibility;
         self.inherited_pub_visibility = false;
         match *node {
@@ -159,7 +159,7 @@ impl<'a, 'tcx> MarkSymbolVisitor<'a, 'tcx> {
                     hir::ItemStruct(..) | hir::ItemUnion(..) => {
                         let def_id = self.tcx.hir.local_def_id(item.id);
                         let def = self.tcx.adt_def(def_id);
-                        self.struct_has_extern_repr = def.repr.c();
+                        self.repr_has_repr_c = def.repr.c();
 
                         intravisit::walk_item(self, &item);
                     }
@@ -187,7 +187,7 @@ impl<'a, 'tcx> MarkSymbolVisitor<'a, 'tcx> {
             }
             _ => ()
         }
-        self.struct_has_extern_repr = had_extern_repr;
+        self.repr_has_repr_c = had_repr_c;
         self.inherited_pub_visibility = had_inherited_pub_visibility;
     }
 
@@ -223,10 +223,10 @@ impl<'a, 'tcx> Visitor<'tcx> for MarkSymbolVisitor<'a, 'tcx> {
 
     fn visit_variant_data(&mut self, def: &'tcx hir::VariantData, _: ast::Name,
                         _: &hir::Generics, _: ast::NodeId, _: syntax_pos::Span) {
-        let has_extern_repr = self.struct_has_extern_repr;
+        let has_repr_c = self.repr_has_repr_c;
         let inherited_pub_visibility = self.inherited_pub_visibility;
         let live_fields = def.fields().iter().filter(|f| {
-            has_extern_repr || inherited_pub_visibility || f.vis == hir::Public
+            has_repr_c || inherited_pub_visibility || f.vis == hir::Public
         });
         self.live_symbols.extend(live_fields.map(|f| f.id));
 
@@ -428,7 +428,7 @@ fn find_live<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
         tcx,
         tables: &ty::TypeckTables::empty(None),
         live_symbols: box FxHashSet(),
-        struct_has_extern_repr: false,
+        repr_has_repr_c: false,
         in_pat: false,
         inherited_pub_visibility: false,
         ignore_variant_stack: vec![],

src/librustc/middle/expr_use_visitor.rs

@@ -663,7 +663,7 @@ impl<'a, 'gcx, 'tcx> ExprUseVisitor<'a, 'gcx, 'tcx> {
         match with_cmt.ty.sty {
             ty::TyAdt(adt, substs) if adt.is_struct() => {
                 // Consume those fields of the with expression that are needed.
-                for with_field in &adt.struct_variant().fields {
+                for with_field in &adt.non_enum_variant().fields {
                     if !contains_field_named(with_field, fields) {
                         let cmt_field = self.mc.cat_field(
                             &*with_expr,

src/librustc/middle/mem_categorization.rs

@@ -1248,7 +1248,7 @@ impl<'a, 'gcx, 'tcx> MemCategorizationContext<'a, 'gcx, 'tcx> {
                 Def::StructCtor(_, CtorKind::Fn) => {
                     match self.pat_ty(&pat)?.sty {
                         ty::TyAdt(adt_def, _) => {
-                            (cmt, adt_def.struct_variant().fields.len())
+                            (cmt, adt_def.non_enum_variant().fields.len())
                         }
                         ref ty => {
                             span_bug!(pat.span, "tuple struct pattern unexpected type {:?}", ty);

src/librustc/session/config.rs

@@ -1084,8 +1084,6 @@ options! {DebuggingOptions, DebuggingSetter, basic_debugging_options,
         "omit landing pads for unwinding"),
     fewer_names: bool = (false, parse_bool, [TRACKED],
         "reduce memory use by retaining fewer names within compilation artifacts (LLVM-IR)"),
-    debug_llvm: bool = (false, parse_bool, [UNTRACKED],
-        "enable debug output from LLVM"),
     meta_stats: bool = (false, parse_bool, [UNTRACKED],
         "gather metadata statistics"),
     print_link_args: bool = (false, parse_bool, [UNTRACKED],
@@ -2747,8 +2745,6 @@ mod tests {
         assert_eq!(reference.dep_tracking_hash(), opts.dep_tracking_hash());
         opts.debugging_opts.borrowck_stats = true;
         assert_eq!(reference.dep_tracking_hash(), opts.dep_tracking_hash());
-        opts.debugging_opts.debug_llvm = true;
-        assert_eq!(reference.dep_tracking_hash(), opts.dep_tracking_hash());
         opts.debugging_opts.meta_stats = true;
         assert_eq!(reference.dep_tracking_hash(), opts.dep_tracking_hash());
         opts.debugging_opts.print_link_args = true;

src/librustc/ty/layout.rs

@@ -2295,6 +2295,13 @@ impl<'a, 'tcx> TyLayout<'tcx> {
             }, niche_start))
         };
 
+        // Locals variables which live across yields are stored
+        // in the generator type as fields. These may be uninitialized
+        // so we don't look for niches there.
+        if let ty::TyGenerator(..) = self.ty.sty {
+            return Ok(None);
+        }
+
         match self.abi {
             Abi::Scalar(ref scalar) => {
                 return Ok(scalar_component(scalar, Size::from_bytes(0)));

src/librustc/ty/mod.rs

@@ -1538,7 +1538,7 @@ impl ReprOptions {
         for attr in tcx.get_attrs(did).iter() {
             for r in attr::find_repr_attrs(tcx.sess.diagnostic(), attr) {
                 flags.insert(match r {
-                    attr::ReprExtern => ReprFlags::IS_C,
+                    attr::ReprC => ReprFlags::IS_C,
                     attr::ReprPacked => ReprFlags::IS_PACKED,
                     attr::ReprSimd => ReprFlags::IS_SIMD,
                     attr::ReprInt(i) => {
@@ -1691,10 +1691,9 @@ impl<'a, 'gcx, 'tcx> AdtDef {
         self.destructor(tcx).is_some()
     }
 
-    /// Asserts this is a struct and returns the struct's unique
-    /// variant.
-    pub fn struct_variant(&self) -> &VariantDef {
-        assert!(!self.is_enum());
+    /// Asserts this is a struct or union and returns its unique variant.
+    pub fn non_enum_variant(&self) -> &VariantDef {
+        assert!(self.is_struct() || self.is_union());
         &self.variants[0]
     }
 
@@ -1733,7 +1732,7 @@ impl<'a, 'gcx, 'tcx> AdtDef {
         match def {
             Def::Variant(vid) | Def::VariantCtor(vid, ..) => self.variant_with_id(vid),
             Def::Struct(..) | Def::StructCtor(..) | Def::Union(..) |
-            Def::TyAlias(..) | Def::AssociatedTy(..) | Def::SelfTy(..) => self.struct_variant(),
+            Def::TyAlias(..) | Def::AssociatedTy(..) | Def::SelfTy(..) => self.non_enum_variant(),
             _ => bug!("unexpected def {:?} in variant_of_def", def)
         }
     }
@@ -2319,11 +2318,11 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
                 self.adt_def(enum_did).variant_with_id(did)
             }
             Def::Struct(did) | Def::Union(did) => {
-                self.adt_def(did).struct_variant()
+                self.adt_def(did).non_enum_variant()
             }
             Def::StructCtor(ctor_did, ..) => {
                 let did = self.parent_def_id(ctor_did).expect("struct ctor has no parent");
-                self.adt_def(did).struct_variant()
+                self.adt_def(did).non_enum_variant()
             }
             _ => bug!("expect_variant_def used with unexpected def {:?}", def)
         }

src/librustc/ty/sty.rs

@@ -1351,15 +1351,15 @@ impl<'a, 'gcx, 'tcx> TyS<'tcx> {
     pub fn simd_type(&self, tcx: TyCtxt<'a, 'gcx, 'tcx>) -> Ty<'tcx> {
         match self.sty {
             TyAdt(def, substs) => {
-                def.struct_variant().fields[0].ty(tcx, substs)
+                def.non_enum_variant().fields[0].ty(tcx, substs)
             }
             _ => bug!("simd_type called on invalid type")
         }
     }
 
     pub fn simd_size(&self, _cx: TyCtxt) -> usize {
         match self.sty {
-            TyAdt(def, _) => def.struct_variant().fields.len(),
+            TyAdt(def, _) => def.non_enum_variant().fields.len(),
             _ => bug!("simd_size called on invalid type")
         }
     }

src/librustc/ty/util.rs

@@ -258,7 +258,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
                 adt.variant_with_id(vid).fields.get(i).map(|f| f.ty(self, substs))
             }
             (&TyAdt(adt, substs), None) => {
-                // Don't use `struct_variant`, this may be a univariant enum.
+                // Don't use `non_enum_variant`, this may be a univariant enum.
                 adt.variants[0].fields.get(i).map(|f| f.ty(self, substs))
             }
             (&TyTuple(ref v, _), None) => v.get(i).cloned(),
@@ -277,7 +277,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
                 adt.variant_with_id(vid).find_field_named(n).map(|f| f.ty(self, substs))
             }
             (&TyAdt(adt, substs), None) => {
-                adt.struct_variant().find_field_named(n).map(|f| f.ty(self, substs))
+                adt.non_enum_variant().find_field_named(n).map(|f| f.ty(self, substs))
             }
             _ => return None
         }
@@ -293,7 +293,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
                     if !def.is_struct() {
                         break;
                     }
-                    match def.struct_variant().fields.last() {
+                    match def.non_enum_variant().fields.last() {
                         Some(f) => ty = f.ty(self, substs),
                         None => break,
                     }
@@ -329,7 +329,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
             match (&a.sty, &b.sty) {
                 (&TyAdt(a_def, a_substs), &TyAdt(b_def, b_substs))
                         if a_def == b_def && a_def.is_struct() => {
-                    if let Some(f) = a_def.struct_variant().fields.last() {
+                    if let Some(f) = a_def.non_enum_variant().fields.last() {
                         a = f.ty(self, a_substs);
                         b = f.ty(self, b_substs);
                     } else {

src/librustc_borrowck/borrowck/gather_loans/restrictions.rs

@@ -107,7 +107,7 @@ impl<'a, 'tcx> RestrictionsContext<'a, 'tcx> {
                     ty::TyAdt(adt_def, _) if adt_def.is_union() => match result {
                         RestrictionResult::Safe => RestrictionResult::Safe,
                         RestrictionResult::SafeIf(base_lp, mut base_vec) => {
-                            for field in &adt_def.struct_variant().fields {
+                            for field in &adt_def.non_enum_variant().fields {
                                 let field = InteriorKind::InteriorField(mc::NamedField(field.name));
                                 let field_ty = if field == interior {
                                     cmt.ty

src/librustc_borrowck/borrowck/move_data.rs

@@ -343,7 +343,7 @@ impl<'a, 'tcx> MoveData<'tcx> {
             if let (&ty::TyAdt(adt_def, _), LpInterior(opt_variant_id, interior))
                     = (&base_lp.ty.sty, lp_elem) {
                 if adt_def.is_union() {
-                    for field in &adt_def.struct_variant().fields {
+                    for field in &adt_def.non_enum_variant().fields {
                         let field = InteriorKind::InteriorField(mc::NamedField(field.name));
                         if field != interior {
                             let sibling_lp_kind =
@@ -395,7 +395,7 @@ impl<'a, 'tcx> MoveData<'tcx> {
         if let LpExtend(ref base_lp, mutbl, LpInterior(opt_variant_id, interior)) = lp.kind {
             if let ty::TyAdt(adt_def, _) = base_lp.ty.sty {
                 if adt_def.is_union() {
-                    for field in &adt_def.struct_variant().fields {
+                    for field in &adt_def.non_enum_variant().fields {
                         let field = InteriorKind::InteriorField(mc::NamedField(field.name));
                         let field_ty = if field == interior {
                             lp.ty

src/librustc_driver/lib.rs

@@ -167,7 +167,6 @@ mod rustc_trans {
     pub use rustc_trans_utils::trans_crate::TranslatedCrate as CrateTranslation;
 
     pub fn init(_sess: &Session) {}
-    pub fn enable_llvm_debug() {}
     pub fn print_version() {}
     pub fn print_passes() {}
     pub fn print(_req: PrintRequest, _sess: &Session) {}
@@ -205,10 +204,6 @@ pub fn run_compiler<'a>(args: &[String],
 
     let (sopts, cfg) = config::build_session_options_and_crate_config(&matches);
 
-    if sopts.debugging_opts.debug_llvm {
-        rustc_trans::enable_llvm_debug();
-    }
-
     let descriptions = diagnostics_registry();
 
     do_or_return!(callbacks.early_callback(&matches,

src/librustc_lint/bad_style.rs

@@ -120,17 +120,15 @@ impl LintPass for NonCamelCaseTypes {
 
 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for NonCamelCaseTypes {
     fn check_item(&mut self, cx: &LateContext, it: &hir::Item) {
-        let extern_repr_count = it.attrs
+        let has_repr_c = it.attrs
             .iter()
-            .filter(|attr| {
+            .any(|attr| {
                 attr::find_repr_attrs(cx.tcx.sess.diagnostic(), attr)
                     .iter()
-                    .any(|r| r == &attr::ReprExtern)
-            })
-            .count();
-        let has_extern_repr = extern_repr_count > 0;
+                    .any(|r| r == &attr::ReprC)
+            });
 
-        if has_extern_repr {
+        if has_repr_c {
             return;
         }
 

src/librustc_lint/types.rs

@@ -422,15 +422,15 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
                                               consider adding a #[repr(C)] attribute to the type");
                         }
 
-                        if def.struct_variant().fields.is_empty() {
+                        if def.non_enum_variant().fields.is_empty() {
                             return FfiUnsafe("found zero-size struct in foreign module, consider \
                                               adding a member to this struct");
                         }
 
                         // We can't completely trust repr(C) markings; make sure the
                         // fields are actually safe.
                         let mut all_phantom = true;
-                        for field in &def.struct_variant().fields {
+                        for field in &def.non_enum_variant().fields {
                             let field_ty = cx.fully_normalize_associated_types_in(
                                 &field.ty(cx, substs)
                             );
@@ -458,13 +458,13 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
                                               consider adding a #[repr(C)] attribute to the type");
                         }
 
-                        if def.struct_variant().fields.is_empty() {
+                        if def.non_enum_variant().fields.is_empty() {
                             return FfiUnsafe("found zero-size union in foreign module, consider \
                                               adding a member to this union");
                         }
 
                         let mut all_phantom = true;
-                        for field in &def.struct_variant().fields {
+                        for field in &def.non_enum_variant().fields {
                             let field_ty = cx.fully_normalize_associated_types_in(
                                 &field.ty(cx, substs)
                             );

src/librustc_llvm/ffi.rs

@@ -1315,9 +1315,6 @@ extern "C" {
                              ElementCount: c_uint,
                              Packed: Bool);
 
-    /// Enables LLVM debug output.
-    pub fn LLVMRustSetDebug(Enabled: c_int);
-
     /// Prepares inline assembly.
     pub fn LLVMRustInlineAsm(Ty: TypeRef,
                              AsmString: *const c_char,
@@ -1610,7 +1607,6 @@ extern "C" {
     pub fn LLVMRustSetNormalizedTarget(M: ModuleRef, triple: *const c_char);
     pub fn LLVMRustAddAlwaysInlinePass(P: PassManagerBuilderRef, AddLifetimes: bool);
     pub fn LLVMRustLinkInExternalBitcode(M: ModuleRef, bc: *const c_char, len: size_t) -> bool;
-    pub fn LLVMRustLinkInParsedExternalBitcode(M: ModuleRef, M: ModuleRef) -> bool;
     pub fn LLVMRustRunRestrictionPass(M: ModuleRef, syms: *const *const c_char, len: size_t);
     pub fn LLVMRustMarkAllFunctionsNounwind(M: ModuleRef);
 
@@ -1646,8 +1642,6 @@ extern "C" {
     pub fn LLVMRustWriteDiagnosticInfoToString(DI: DiagnosticInfoRef, s: RustStringRef);
     pub fn LLVMRustGetDiagInfoKind(DI: DiagnosticInfoRef) -> DiagnosticKind;
 
-    pub fn LLVMRustWriteDebugLocToString(C: ContextRef, DL: DebugLocRef, s: RustStringRef);
-
     pub fn LLVMRustSetInlineAsmDiagnosticHandler(C: ContextRef,
                                                  H: InlineAsmDiagHandler,
                                                  CX: *mut c_void);

src/librustc_llvm/lib.rs

@@ -296,11 +296,6 @@ pub unsafe fn twine_to_string(tr: TwineRef) -> String {
     build_string(|s| LLVMRustWriteTwineToString(tr, s)).expect("got a non-UTF8 Twine from LLVM")
 }
 
-pub unsafe fn debug_loc_to_string(c: ContextRef, tr: DebugLocRef) -> String {
-    build_string(|s| LLVMRustWriteDebugLocToString(c, tr, s))
-        .expect("got a non-UTF8 DebugLoc from LLVM")
-}
-
 pub fn initialize_available_targets() {
     macro_rules! init_target(
         ($cfg:meta, $($method:ident),*) => { {