Auto merge of #65322 - tmandry:rollup-frr651r, r=tmandry

Rollup of 15 pull requests

Successful merges:

 - #64337 (libstd: Fix typos in doc)
 - #64986 (Function pointers as const generic arguments)
 - #65048 (Added doc about behavior of extend on HashMap)
 - #65191 (Add some regression tests)
 - #65200 (Add ?Sized bound to a supertrait listing in E0038 error documentation)
 - #65205 (Add long error explanation for E0568)
 - #65220 (Update LLVM for Emscripten exception handling support)
 - #65263 (Deduplicate is_{freeze,copy,sized}_raw)
 - #65266 (Mark Path::join as must_use)
 - #65276 (Don't cc rust-lang/compiler for toolstate changes)
 - #65277 (Query generator kind for error reporting)
 - #65283 (stability: Do not use `buffer_lint` after lowering to HIR)
 - #65289 (Fix suggested bound addition diagnostic)
 - #65310 (deriving: avoid dummy Span on an artificial `type_ident` path)
 - #65321 (Remove painful test that is not pulling its weight)

Failed merges:

r? @ghost

Author: bors

src/librustc/error_codes.rs

@@ -259,8 +259,8 @@ trait Foo {
 This is similar to the second sub-error, but subtler. It happens in situations
 like the following:
 
-```compile_fail
-trait Super<A> {}
+```compile_fail,E0038
+trait Super<A: ?Sized> {}
 
 trait Trait: Super<Self> {
 }
@@ -270,17 +270,21 @@ struct Foo;
 impl Super<Foo> for Foo{}
 
 impl Trait for Foo {}
+
+fn main() {
+    let x: Box<dyn Trait>;
+}
 ```
 
 Here, the supertrait might have methods as follows:
 
 ```
-trait Super<A> {
-    fn get_a(&self) -> A; // note that this is object safe!
+trait Super<A: ?Sized> {
+    fn get_a(&self) -> &A; // note that this is object safe!
 }
 ```
 
-If the trait `Foo` was deriving from something like `Super<String>` or
+If the trait `Trait` was deriving from something like `Super<String>` or
 `Super<T>` (where `Foo` itself is `Foo<T>`), this is okay, because given a type
 `get_a()` will definitely return an object of that type.
 

src/librustc/hir/mod.rs

@@ -1366,6 +1366,10 @@ impl Body {
             hir_id: self.value.hir_id,
         }
     }
+
+    pub fn generator_kind(&self) -> Option<GeneratorKind> {
+        self.generator_kind
+    }
 }
 
 /// The type of source expression that caused this generator to be created.

src/librustc/middle/stability.rs

@@ -485,7 +485,13 @@ pub fn provide(providers: &mut Providers<'_>) {
 }
 
 pub fn report_unstable(
-    sess: &Session, feature: Symbol, reason: Option<Symbol>, issue: u32, is_soft: bool, span: Span
+    sess: &Session,
+    feature: Symbol,
+    reason: Option<Symbol>,
+    issue: u32,
+    is_soft: bool,
+    span: Span,
+    soft_handler: impl FnOnce(&'static lint::Lint, Span, &str),
 ) {
     let msg = match reason {
         Some(r) => format!("use of unstable library feature '{}': {}", feature, r),
@@ -511,7 +517,7 @@ pub fn report_unstable(
     let fresh = sess.one_time_diagnostics.borrow_mut().insert(error_id);
     if fresh {
         if is_soft {
-            sess.buffer_lint(lint::builtin::SOFT_UNSTABLE, CRATE_NODE_ID, span, &msg);
+            soft_handler(lint::builtin::SOFT_UNSTABLE, span, &msg)
         } else {
             emit_feature_err(
                 &sess.parse_sess, feature, span, GateIssue::Library(Some(issue)), &msg
@@ -779,10 +785,12 @@ impl<'tcx> TyCtxt<'tcx> {
     /// Additionally, this function will also check if the item is deprecated. If so, and `id` is
     /// not `None`, a deprecated lint attached to `id` will be emitted.
     pub fn check_stability(self, def_id: DefId, id: Option<HirId>, span: Span) {
+        let soft_handler =
+            |lint, span, msg: &_| self.lint_hir(lint, id.unwrap_or(hir::CRATE_HIR_ID), span, msg);
         match self.eval_stability(def_id, id, span) {
             EvalResult::Allow => {}
             EvalResult::Deny { feature, reason, issue, is_soft } =>
-                report_unstable(self.sess, feature, reason, issue, is_soft, span),
+                report_unstable(self.sess, feature, reason, issue, is_soft, span, soft_handler),
             EvalResult::Unmarked => {
                 // The API could be uncallable for other reasons, for example when a private module
                 // was referenced.

src/librustc/mir/interpret/mod.rs

@@ -470,6 +470,14 @@ impl<'tcx> AllocMap<'tcx> {
         }
     }
 
+    /// Panics if the `AllocId` does not refer to a function
+    pub fn unwrap_fn(&self, id: AllocId) -> Instance<'tcx> {
+        match self.get(id) {
+            Some(GlobalAlloc::Function(instance)) => instance,
+            _ => bug!("expected allocation ID {} to point to a function", id),
+        }
+    }
+
     /// Freezes an `AllocId` created with `reserve` by pointing it at an `Allocation`. Trying to
     /// call this function twice, even with the same `Allocation` will ICE the compiler.
     pub fn set_alloc_id_memory(&mut self, id: AllocId, mem: &'tcx Allocation) {

src/librustc/mir/mod.rs

@@ -2602,7 +2602,14 @@ impl<'tcx> Debug for Constant<'tcx> {
 impl<'tcx> Display for Constant<'tcx> {
     fn fmt(&self, fmt: &mut Formatter<'_>) -> fmt::Result {
         write!(fmt, "const ")?;
-        write!(fmt, "{}", self.literal)
+        // FIXME make the default pretty printing of raw pointers more detailed. Here we output the
+        // debug representation of raw pointers, so that the raw pointers in the mir dump output are
+        // detailed and just not '{pointer}'.
+        if let ty::RawPtr(_) = self.literal.ty.kind {
+            write!(fmt, "{:?} : {}", self.literal.val, self.literal.ty)
+        } else {
+            write!(fmt, "{}", self.literal)
+        }
     }
 }
 

src/librustc/ty/print/pretty.rs

@@ -863,125 +863,121 @@ pub trait PrettyPrinter<'tcx>:
         }
 
         let u8 = self.tcx().types.u8;
-        if let ty::FnDef(did, substs) = ct.ty.kind {
-            p!(print_value_path(did, substs));
-            return Ok(self);
-        }
-        if let ConstValue::Unevaluated(did, substs) = ct.val {
-            match self.tcx().def_kind(did) {
-                | Some(DefKind::Static)
-                | Some(DefKind::Const)
-                | Some(DefKind::AssocConst) => p!(print_value_path(did, substs)),
-                _ => if did.is_local() {
-                    let span = self.tcx().def_span(did);
-                    if let Ok(snip) = self.tcx().sess.source_map().span_to_snippet(span) {
-                        p!(write("{}", snip))
+
+        match (ct.val, &ct.ty.kind) {
+            (_,  ty::FnDef(did, substs)) => p!(print_value_path(*did, substs)),
+            (ConstValue::Unevaluated(did, substs), _) => {
+                match self.tcx().def_kind(did) {
+                    | Some(DefKind::Static)
+                    | Some(DefKind::Const)
+                    | Some(DefKind::AssocConst) => p!(print_value_path(did, substs)),
+                    _ => if did.is_local() {
+                        let span = self.tcx().def_span(did);
+                        if let Ok(snip) = self.tcx().sess.source_map().span_to_snippet(span) {
+                            p!(write("{}", snip))
+                        } else {
+                            p!(write("_: "), print(ct.ty))
+                        }
                     } else {
                         p!(write("_: "), print(ct.ty))
-                    }
+                    },
+                }
+            },
+            (ConstValue::Infer(..), _) =>  p!(write("_: "), print(ct.ty)),
+            (ConstValue::Param(ParamConst { name, .. }), _) => p!(write("{}", name)),
+            (ConstValue::Scalar(Scalar::Raw { data, .. }), ty::Bool) =>
+                p!(write("{}", if data == 0 { "false" } else { "true" })),
+            (ConstValue::Scalar(Scalar::Raw { data, .. }), ty::Float(ast::FloatTy::F32)) =>
+                p!(write("{}f32", Single::from_bits(data))),
+            (ConstValue::Scalar(Scalar::Raw { data, .. }), ty::Float(ast::FloatTy::F64)) =>
+                p!(write("{}f64", Double::from_bits(data))),
+            (ConstValue::Scalar(Scalar::Raw { data, .. }), ty::Uint(ui)) => {
+                let bit_size = Integer::from_attr(&self.tcx(), UnsignedInt(*ui)).size();
+                let max = truncate(u128::max_value(), bit_size);
+
+                if data == max {
+                    p!(write("std::{}::MAX", ui))
                 } else {
-                    p!(write("_: "), print(ct.ty))
-                },
-            }
-            return Ok(self);
-        }
-        if let ConstValue::Infer(..) = ct.val {
-            p!(write("_: "), print(ct.ty));
-            return Ok(self);
-        }
-        if let ConstValue::Param(ParamConst { name, .. }) = ct.val {
-            p!(write("{}", name));
-            return Ok(self);
-        }
-        if let ConstValue::Scalar(Scalar::Raw { data, .. }) = ct.val {
-            match ct.ty.kind {
-                ty::Bool => {
-                    p!(write("{}", if data == 0 { "false" } else { "true" }));
-                    return Ok(self);
-                },
-                ty::Float(ast::FloatTy::F32) => {
-                    p!(write("{}f32", Single::from_bits(data)));
-                    return Ok(self);
-                },
-                ty::Float(ast::FloatTy::F64) => {
-                    p!(write("{}f64", Double::from_bits(data)));
-                    return Ok(self);
-                },
-                ty::Uint(ui) => {
-                    let bit_size = Integer::from_attr(&self.tcx(), UnsignedInt(ui)).size();
-                    let max = truncate(u128::max_value(), bit_size);
+                    p!(write("{}{}", data, ui))
+                };
+            },
+            (ConstValue::Scalar(Scalar::Raw { data, .. }), ty::Int(i)) => {
+                let bit_size = Integer::from_attr(&self.tcx(), SignedInt(*i))
+                    .size().bits() as u128;
+                let min = 1u128 << (bit_size - 1);
+                let max = min - 1;
+
+                let ty = self.tcx().lift(&ct.ty).unwrap();
+                let size = self.tcx().layout_of(ty::ParamEnv::empty().and(ty))
+                    .unwrap()
+                    .size;
+                match data {
+                    d if d == min => p!(write("std::{}::MIN", i)),
+                    d if d == max => p!(write("std::{}::MAX", i)),
+                    _ => p!(write("{}{}", sign_extend(data, size) as i128, i))
+                }
+            },
+            (ConstValue::Scalar(Scalar::Raw { data, .. }), ty::Char) =>
+                p!(write("{:?}", ::std::char::from_u32(data as u32).unwrap())),
+            (ConstValue::Scalar(_), ty::RawPtr(_)) => p!(write("{{pointer}}")),
+            (ConstValue::Scalar(Scalar::Ptr(ptr)), ty::FnPtr(_)) => {
+                let instance = {
+                    let alloc_map = self.tcx().alloc_map.lock();
+                    alloc_map.unwrap_fn(ptr.alloc_id)
+                };
+                p!(print_value_path(instance.def_id(), instance.substs));
+            },
+            _ => {
+                let printed = if let ty::Ref(_, ref_ty, _) = ct.ty.kind {
+                    let byte_str = match (ct.val, &ref_ty.kind) {
+                        (ConstValue::Scalar(Scalar::Ptr(ptr)), ty::Array(t, n)) if *t == u8 => {
+                            let n = n.eval_usize(self.tcx(), ty::ParamEnv::empty());
+                            Some(self.tcx()
+                                .alloc_map.lock()
+                                .unwrap_memory(ptr.alloc_id)
+                                .get_bytes(&self.tcx(), ptr, Size::from_bytes(n)).unwrap())
+                        },
+                        (ConstValue::Slice { data, start, end }, ty::Slice(t)) if *t == u8 => {
+                            // The `inspect` here is okay since we checked the bounds, and there are
+                            // no relocations (we have an active slice reference here). We don't use
+                            // this result to affect interpreter execution.
+                            Some(data.inspect_with_undef_and_ptr_outside_interpreter(start..end))
+                        },
+                        _ => None,
+                    };
 
-                    if data == max {
-                        p!(write("std::{}::MAX", ui))
+                    if let Some(byte_str) = byte_str {
+                        p!(write("b\""));
+                        for &c in byte_str {
+                            for e in std::ascii::escape_default(c) {
+                                self.write_char(e as char)?;
+                            }
+                        }
+                        p!(write("\""));
+                        true
+                    } else if let (ConstValue::Slice { data, start, end }, ty::Str) =
+                        (ct.val, &ref_ty.kind)
+                    {
+                        // The `inspect` here is okay since we checked the bounds, and there are no
+                        // relocations (we have an active `str` reference here). We don't use this
+                        // result to affect interpreter execution.
+                        let slice = data.inspect_with_undef_and_ptr_outside_interpreter(start..end);
+                        let s = ::std::str::from_utf8(slice)
+                            .expect("non utf8 str from miri");
+                        p!(write("{:?}", s));
+                        true
                     } else {
-                        p!(write("{}{}", data, ui))
-                    };
-                    return Ok(self);
-                },
-                ty::Int(i) =>{
-                    let bit_size = Integer::from_attr(&self.tcx(), SignedInt(i))
-                        .size().bits() as u128;
-                    let min = 1u128 << (bit_size - 1);
-                    let max = min - 1;
-
-                    let ty = self.tcx().lift(&ct.ty).unwrap();
-                    let size = self.tcx().layout_of(ty::ParamEnv::empty().and(ty))
-                        .unwrap()
-                        .size;
-                    match data {
-                        d if d == min => p!(write("std::{}::MIN", i)),
-                        d if d == max => p!(write("std::{}::MAX", i)),
-                        _ => p!(write("{}{}", sign_extend(data, size) as i128, i))
-                    }
-                    return Ok(self);
-                },
-                ty::Char => {
-                    p!(write("{:?}", ::std::char::from_u32(data as u32).unwrap()));
-                    return Ok(self);
-                }
-                _ => {},
-            }
-        }
-        if let ty::Ref(_, ref_ty, _) = ct.ty.kind {
-            let byte_str = match (ct.val, &ref_ty.kind) {
-                (ConstValue::Scalar(Scalar::Ptr(ptr)), ty::Array(t, n)) if *t == u8 => {
-                    let n = n.eval_usize(self.tcx(), ty::ParamEnv::empty());
-                    Some(self.tcx()
-                        .alloc_map.lock()
-                        .unwrap_memory(ptr.alloc_id)
-                        .get_bytes(&self.tcx(), ptr, Size::from_bytes(n)).unwrap())
-                },
-                (ConstValue::Slice { data, start, end }, ty::Slice(t)) if *t == u8 => {
-                    // The `inspect` here is okay since we checked the bounds, and there are no
-                    // relocations (we have an active slice reference here). We don't use this
-                    // result to affect interpreter execution.
-                    Some(data.inspect_with_undef_and_ptr_outside_interpreter(start..end))
-                },
-                (ConstValue::Slice { data, start, end }, ty::Str) => {
-                    // The `inspect` here is okay since we checked the bounds, and there are no
-                    // relocations (we have an active `str` reference here). We don't use this
-                    // result to affect interpreter execution.
-                    let slice = data.inspect_with_undef_and_ptr_outside_interpreter(start..end);
-                    let s = ::std::str::from_utf8(slice)
-                        .expect("non utf8 str from miri");
-                    p!(write("{:?}", s));
-                    return Ok(self);
-                },
-                _ => None,
-            };
-            if let Some(byte_str) = byte_str {
-                p!(write("b\""));
-                for &c in byte_str {
-                    for e in std::ascii::escape_default(c) {
-                        self.write_char(e as char)?;
+                        false
                     }
+                } else {
+                    false
+                };
+                if !printed {
+                    // fallback
+                    p!(write("{:?} : ", ct.val), print(ct.ty))
                 }
-                p!(write("\""));
-                return Ok(self);
             }
-        }
-        p!(write("{:?} : ", ct.val), print(ct.ty));
-
+        };
         Ok(self)
     }
 }