Rollup of 6 pull requests

Cargo.lock

@@ -115,9 +115,9 @@ checksum = "b671c8fb71b457dd4ae18c4ba1e59aa81793daacc361d82fcd410cef0d491875"
 
 [[package]]
 name = "backtrace"
-version = "0.3.37"
+version = "0.3.40"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5180c5a20655b14a819b652fd2378fa5f1697b6c9ddad3e695c2f9cedf6df4e2"
+checksum = "924c76597f0d9ca25d762c25a4d369d51267536465dc5064bdf0eb073ed477ea"
 dependencies = [
  "backtrace-sys",
  "cfg-if",
@@ -129,9 +129,9 @@ dependencies = [
 
 [[package]]
 name = "backtrace-sys"
-version = "0.1.30"
+version = "0.1.32"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5b3a000b9c543553af61bc01cbfc403b04b5caa9e421033866f2e98061eb3e61"
+checksum = "5d6575f128516de27e3ce99689419835fce9643a9b215a14d2b5b685be018491"
 dependencies = [
  "cc",
  "compiler_builtins",
@@ -150,9 +150,9 @@ dependencies = [
 
 [[package]]
 name = "bitflags"
-version = "1.1.0"
+version = "1.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3d155346769a6855b86399e9bc3814ab343cd3d62c7e985113d46a0ec3c281fd"
+checksum = "cf1de2fe8c75bc145a2f577add951f8134889b4795d47466a54a5c846d691693"
 
 [[package]]
 name = "blake2-rfc"
@@ -391,9 +391,9 @@ version = "0.1.0"
 
 [[package]]
 name = "cc"
-version = "1.0.35"
+version = "1.0.37"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5e5f3fee5eeb60324c2781f1e41286bdee933850fff9b3c672587fed5ec58c83"
+checksum = "39f75544d7bbaf57560d2168f28fd649ff9c76153874db88bdbdfd839b1a7e7d"
 
 [[package]]
 name = "cfg-if"
@@ -3113,6 +3113,7 @@ dependencies = [
  "backtrace",
  "bitflags",
  "byteorder",
+ "cc",
  "chalk-engine",
  "fmt_macros",
  "graphviz",

src/librustc/Cargo.toml

@@ -10,8 +10,12 @@ path = "lib.rs"
 doctest = false
 
 [dependencies]
+# Prevent cc from upgrading all the way to 1.0.46,
+# which fails the build (see e.g. #65445.)
+cc = "=1.0.37"
+
 arena = { path = "../libarena" }
-bitflags = "1.0"
+bitflags = "1.2.1"
 fmt_macros = { path = "../libfmt_macros" }
 graphviz = { path = "../libgraphviz" }
 jobserver = "0.1"
@@ -30,7 +34,7 @@ errors = { path = "../librustc_errors", package = "rustc_errors" }
 rustc_serialize = { path = "../libserialize", package = "serialize" }
 syntax = { path = "../libsyntax" }
 syntax_pos = { path = "../libsyntax_pos" }
-backtrace = "0.3.3"
+backtrace = "0.3.40"
 parking_lot = "0.9"
 byteorder = { version = "1.3" }
 chalk-engine = { version = "0.9.0", default-features=false }

src/librustc/error_codes.rs

@@ -2219,7 +2219,7 @@ rejected in your own crates.
 "##,
 
 E0736: r##"
-#[track_caller] and #[naked] cannot be applied to the same function.
+`#[track_caller]` and `#[naked]` cannot both be applied to the same function.
 
 Erroneous code example:
 
@@ -2237,6 +2237,57 @@ See [RFC 2091] for details on this and other limitations.
 [RFC 2091]: https://github.com/rust-lang/rfcs/blob/master/text/2091-inline-semantic.md
 "##,
 
+E0738: r##"
+`#[track_caller]` cannot be used in traits yet. This is due to limitations in
+the compiler which are likely to be temporary. See [RFC 2091] for details on
+this and other restrictions.
+
+Erroneous example with a trait method implementation:
+
+```compile_fail,E0738
+#![feature(track_caller)]
+
+trait Foo {
+    fn bar(&self);
+}
+
+impl Foo for u64 {
+    #[track_caller]
+    fn bar(&self) {}
+}
+```
+
+Erroneous example with a blanket trait method implementation:
+
+```compile_fail,E0738
+#![feature(track_caller)]
+
+trait Foo {
+    #[track_caller]
+    fn bar(&self) {}
+    fn baz(&self);
+}
+```
+
+Erroneous example with a trait method declaration:
+
+```compile_fail,E0738
+#![feature(track_caller)]
+
+trait Foo {
+    fn bar(&self) {}
+
+    #[track_caller]
+    fn baz(&self);
+}
+```
+
+Note that while the compiler may be able to support the attribute in traits in
+the future, [RFC 2091] prohibits their implementation without a follow-up RFC.
+
+[RFC 2091]: https://github.com/rust-lang/rfcs/blob/master/text/2091-inline-semantic.md
+"##,
+
 ;
 //  E0006, // merged with E0005
 //  E0101, // replaced with E0282