Auto merge of #61460 - Centril:rollup-8txhjx4, r=Centril

Rollup of 6 pull requests

Successful merges:

 - #61380 (Fix some issues with `unwrap_usize` instead of `assert_usize`)
 - #61423 (codegen: change `$6d$` to `$u6d$`)
 - #61438 (Point at individual type args on arg count mismatch)
 - #61441 (Tweak wording when encountering `fn` call in pattern)
 - #61451 (Fix missing semicolon in doc)
 - #61458 (Fix typo in AsRef doc)

Failed merges:

r? @ghost

Author: bors

src/libcore/convert.rs

@@ -129,7 +129,7 @@ pub const fn identity<T>(x: T) -> T { x }
 /// # Examples
 ///
 /// By using trait bounds we can accept arguments of different types as long as they can be
-/// converted a the specified type `T`.
+/// converted to the specified type `T`.
 ///
 /// For example: By creating a generic function that takes an `AsRef<str>` we express that we
 /// want to accept all references that can be converted to `&str` as an argument.

src/librustc/hir/map/mod.rs

@@ -628,10 +628,6 @@ impl<'hir> Map<'hir> {
         })
     }
 
-    pub fn get_generics_span(&self, id: DefId) -> Option<Span> {
-        self.get_generics(id).map(|generics| generics.span).filter(|sp| *sp != DUMMY_SP)
-    }
-
     /// Retrieves the `Node` corresponding to `id`, returning `None` if cannot be found.
     pub fn find(&self, id: NodeId) -> Option<Node<'hir>> {
         let hir_id = self.node_to_hir_id(id);

src/librustc/hir/mod.rs

@@ -16,7 +16,7 @@ use crate::util::nodemap::{NodeMap, FxHashSet};
 use crate::mir::mono::Linkage;
 
 use errors::FatalError;
-use syntax_pos::{Span, DUMMY_SP, symbol::InternedString};
+use syntax_pos::{Span, DUMMY_SP, symbol::InternedString, MultiSpan};
 use syntax::source_map::Spanned;
 use rustc_target::spec::abi::Abi;
 use syntax::ast::{self, CrateSugar, Ident, Name, NodeId, AsmDialect};
@@ -625,6 +625,14 @@ impl Generics {
         }
         None
     }
+
+    pub fn spans(&self) -> MultiSpan {
+        if self.params.is_empty() {
+            self.span.into()
+        } else {
+            self.params.iter().map(|p| p.span).collect::<Vec<Span>>().into()
+        }
+    }
 }
 
 /// Synthetic type parameters are converted to another form during lowering; this allows

src/librustc/traits/error_reporting.rs

@@ -914,8 +914,11 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
             }
 
             // already reported in the query
-            ConstEvalFailure(_) => {
-                self.tcx.sess.delay_span_bug(span, "constant in type had an ignored error");
+            ConstEvalFailure(err) => {
+                self.tcx.sess.delay_span_bug(
+                    span,
+                    &format!("constant in type had an ignored error: {:?}", err),
+                );
                 return;
             }
 

src/librustc/ty/layout.rs

@@ -549,8 +549,8 @@ impl<'a, 'tcx> LayoutCx<'tcx, TyCtxt<'a, 'tcx, 'tcx>> {
                     }
                 }
 
+                let count = count.assert_usize(tcx).ok_or(LayoutError::Unknown(ty))?;
                 let element = self.layout_of(element)?;
-                let count = count.unwrap_usize(tcx);
                 let size = element.size.checked_mul(count, dl)
                     .ok_or(LayoutError::SizeOverflow(ty))?;
 

src/librustc_codegen_llvm/debuginfo/metadata.rs

@@ -342,9 +342,7 @@ fn fixed_vec_metadata(
     let (size, align) = cx.size_and_align_of(array_or_slice_type);
 
     let upper_bound = match array_or_slice_type.sty {
-        ty::Array(_, len) => {
-            len.unwrap_usize(cx.tcx) as c_longlong
-        }
+        ty::Array(_, len) => len.unwrap_usize(cx.tcx) as c_longlong,
         _ => -1
     };
 

src/librustc_codegen_utils/symbol_names/legacy.rs

@@ -440,7 +440,7 @@ impl fmt::Write for SymbolPrinter<'_, '_> {
                 '-' | ':' => self.path.temp_buf.push('.'),
 
                 // Avoid crashing LLVM in certain (LTO-related) situations, see #60925.
-                'm' if self.path.temp_buf.ends_with(".llv") => self.path.temp_buf.push_str("$6d$"),
+                'm' if self.path.temp_buf.ends_with(".llv") => self.path.temp_buf.push_str("$u6d$"),
 
                 // These are legal symbols
                 'a'..='z' | 'A'..='Z' | '0'..='9' | '_' | '.' | '$' => self.path.temp_buf.push(c),

src/librustc_mir/borrow_check/places_conflict.rs

@@ -332,8 +332,8 @@ fn place_base_conflict<'a, 'gcx: 'tcx, 'tcx>(
                 },
                 (StaticKind::Promoted(promoted_1), StaticKind::Promoted(promoted_2)) => {
                     if promoted_1 == promoted_2 {
-                        if let ty::Array(_, size) = s1.ty.sty {
-                            if size.unwrap_usize(tcx) == 0 {
+                        if let ty::Array(_, len) = s1.ty.sty {
+                            if let Some(0) = len.assert_usize(tcx) {
                                 // Ignore conflicts with promoted [T; 0].
                                 debug!("place_element_conflict: IGNORE-LEN-0-PROMOTED");
                                 return Overlap::Disjoint;

src/librustc_mir/transform/qualify_consts.rs

@@ -316,8 +316,9 @@ impl Qualif for HasMutInterior {
                     } else if let ty::Array(_, len) = ty.sty {
                         // FIXME(eddyb) the `cx.mode == Mode::Fn` condition
                         // seems unnecessary, given that this is merely a ZST.
-                        if !(len.unwrap_usize(cx.tcx) == 0 && cx.mode == Mode::Fn) {
-                            return true;
+                        match len.assert_usize(cx.tcx) {
+                            Some(0) if cx.mode == Mode::Fn => {},
+                            _ => return true,
                         }
                     } else {
                         return true;

src/librustc_typeck/check/_match.rs

@@ -400,27 +400,36 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
                 let expected_ty = self.structurally_resolved_type(pat.span, expected);
                 let (inner_ty, slice_ty) = match expected_ty.sty {
                     ty::Array(inner_ty, size) => {
-                        let size = size.unwrap_usize(tcx);
-                        let min_len = before.len() as u64 + after.len() as u64;
-                        if slice.is_none() {
-                            if min_len != size {
-                                struct_span_err!(
-                                    tcx.sess, pat.span, E0527,
-                                    "pattern requires {} elements but array has {}",
-                                    min_len, size)
-                                    .span_label(pat.span, format!("expected {} elements", size))
+                        if let Some(size) = size.assert_usize(tcx) {
+                            let min_len = before.len() as u64 + after.len() as u64;
+                            if slice.is_none() {
+                                if min_len != size {
+                                    struct_span_err!(
+                                        tcx.sess, pat.span, E0527,
+                                        "pattern requires {} elements but array has {}",
+                                        min_len, size)
+                                        .span_label(pat.span, format!("expected {} elements", size))
+                                        .emit();
+                                }
+                                (inner_ty, tcx.types.err)
+                            } else if let Some(rest) = size.checked_sub(min_len) {
+                                (inner_ty, tcx.mk_array(inner_ty, rest))
+                            } else {
+                                struct_span_err!(tcx.sess, pat.span, E0528,
+                                        "pattern requires at least {} elements but array has {}",
+                                        min_len, size)
+                                    .span_label(pat.span,
+                                        format!("pattern cannot match array of {} elements", size))
                                     .emit();
+                                (inner_ty, tcx.types.err)
                             }
-                            (inner_ty, tcx.types.err)
-                        } else if let Some(rest) = size.checked_sub(min_len) {
-                            (inner_ty, tcx.mk_array(inner_ty, rest))
                         } else {
-                            struct_span_err!(tcx.sess, pat.span, E0528,
-                                    "pattern requires at least {} elements but array has {}",
-                                    min_len, size)
-                                .span_label(pat.span,
-                                    format!("pattern cannot match array of {} elements", size))
-                                .emit();
+                            struct_span_err!(
+                                tcx.sess,
+                                pat.span,
+                                E0730,
+                                "cannot pattern-match on an array without a fixed length",
+                            ).emit();
                             (inner_ty, tcx.types.err)
                         }
                     }
@@ -1080,8 +1089,18 @@ https://doc.rust-lang.org/reference/types.html#trait-objects");
             let msg = format!("expected tuple struct/variant, found {} `{}`",
                               res.descr(),
                               hir::print::to_string(tcx.hir(), |s| s.print_qpath(qpath, false)));
-            struct_span_err!(tcx.sess, pat.span, E0164, "{}", msg)
-                .span_label(pat.span, "not a tuple variant or struct").emit();
+            let mut err = struct_span_err!(tcx.sess, pat.span, E0164, "{}", msg);
+            match (res, &pat.node) {
+                (Res::Def(DefKind::Fn, _), _) | (Res::Def(DefKind::Method, _), _) => {
+                    err.span_label(pat.span, "`fn` calls are not allowed in patterns");
+                    err.help("for more information, visit \
+                              https://doc.rust-lang.org/book/ch18-00-patterns.html");
+                }
+                _ => {
+                    err.span_label(pat.span, "not a tuple variant or struct");
+                }
+            }
+            err.emit();
             on_error();
         };