Auto merge of #74958 - Mark-Simulacrum:stable-next, r=pnkfelix

[stable] 1.45.2 release

This is intended to fix the stable breakage noted in #74954, but does *not* close that issue -- there remains investigation and likely nightly/beta fixes need to be issued as well.

r? @pnkfelix

Author: bors

RELEASES.md

@@ -1,3 +1,12 @@
+Version 1.45.2 (2020-08-03)
+==========================
+
+* [Fix bindings in tuple struct patterns][74954]
+* [Fix track_caller integration with trait objects][74784]
+
+[74954]: https://github.com/rust-lang/rust/issues/74954
+[74784]: https://github.com/rust-lang/rust/issues/74784
+
 Version 1.45.1 (2020-07-30)
 ==========================
 

src/librustc_middle/ty/instance.rs

@@ -345,7 +345,7 @@ impl<'tcx> Instance<'tcx> {
             debug!(" => associated item with unsizeable self: Self");
             Some(Instance { def: InstanceDef::VtableShim(def_id), substs })
         } else {
-            Instance::resolve(tcx, param_env, def_id, substs).ok().flatten()
+            Instance::resolve_for_fn_ptr(tcx, param_env, def_id, substs)
         }
     }
 

src/librustc_resolve/late.rs

@@ -1407,30 +1407,18 @@ impl<'a, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
         pat_src: PatternSource,
         bindings: &mut SmallVec<[(PatBoundCtx, FxHashSet<Ident>); 1]>,
     ) {
-        let is_tuple_struct_pat = matches!(pat.kind, PatKind::TupleStruct(_, _));
-
         // Visit all direct subpatterns of this pattern.
         pat.walk(&mut |pat| {
             debug!("resolve_pattern pat={:?} node={:?}", pat, pat.kind);
             match pat.kind {
-                // In tuple struct patterns ignore the invalid `ident @ ...`.
-                // It will be handled as an error by the AST lowering.
                 PatKind::Ident(bmode, ident, ref sub) => {
-                    if is_tuple_struct_pat && sub.as_ref().filter(|p| p.is_rest()).is_some() {
-                        self.r
-                            .session
-                            .delay_span_bug(ident.span, "ident in tuple pattern is invalid");
-                    } else {
-                        // First try to resolve the identifier as some existing entity,
-                        // then fall back to a fresh binding.
-                        let has_sub = sub.is_some();
-                        let res = self
-                            .try_resolve_as_non_binding(pat_src, pat, bmode, ident, has_sub)
-                            .unwrap_or_else(|| {
-                                self.fresh_binding(ident, pat.id, pat_src, bindings)
-                            });
-                        self.r.record_partial_res(pat.id, PartialRes::new(res));
-                    }
+                    // First try to resolve the identifier as some existing entity,
+                    // then fall back to a fresh binding.
+                    let has_sub = sub.is_some();
+                    let res = self
+                        .try_resolve_as_non_binding(pat_src, pat, bmode, ident, has_sub)
+                        .unwrap_or_else(|| self.fresh_binding(ident, pat.id, pat_src, bindings));
+                    self.r.record_partial_res(pat.id, PartialRes::new(res));
                 }
                 PatKind::TupleStruct(ref path, ..) => {
                     self.smart_resolve_path(pat.id, None, path, PathSource::TupleStruct);

src/test/ui/issues/issue-74539.rs

@@ -0,0 +1,7 @@
+// check-pass
+
+fn main() {
+    if let Some([b'@', filename @ ..]) = Some(b"@abc123") {
+        println!("filename {:?}", filename);
+    }
+}

src/test/ui/issues/issue-74539.stderr

@@ -0,0 +1,25 @@
+// run-pass
+
+#![feature(track_caller)]
+
+trait Tracked {
+    #[track_caller]
+    fn handle(&self) {
+        let location = std::panic::Location::caller();
+        assert_eq!(location.file(), file!());
+        // we only call this via trait object, so the def site should *always* be returned
+        assert_eq!(location.line(), line!() - 4);
+        assert_eq!(location.column(), 5);
+    }
+}
+
+impl Tracked for () {}
+impl Tracked for u8 {}
+
+fn main() {
+    let tracked: &dyn Tracked = &5u8;
+    tracked.handle();
+
+    const TRACKED: &dyn Tracked = &();
+    TRACKED.handle();
+}