Stabilize #[track_caller].

Does not yet make its constness stable, though. Use of
`Location::caller` in const contexts is still gated by
`#![feature(const_caller_location)]`.

Author: anp

src/doc/unstable-book/src/language-features/track-caller.md

@@ -118,7 +118,7 @@
 #![feature(staged_api)]
 #![feature(std_internals)]
 #![feature(stmt_expr_attributes)]
-#![feature(track_caller)]
+#![cfg_attr(bootstrap, feature(track_caller))]
 #![feature(transparent_unions)]
 #![feature(unboxed_closures)]
 #![feature(unsized_locals)]

src/libcore/lib.rs

@@ -1,6 +1,6 @@
 #[doc(include = "panic.md")]
 #[macro_export]
-#[allow_internal_unstable(core_panic, track_caller)]
+#[allow_internal_unstable(core_panic, const_caller_location)]
 #[stable(feature = "core", since = "1.6.0")]
 macro_rules! panic {
     () => (

src/libcore/macros/mod.rs

@@ -190,7 +190,6 @@ impl<'a> Location<'a> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(track_caller)]
     /// use core::panic::Location;
     ///
     /// /// Returns the [`Location`] at which it is called.
@@ -206,7 +205,7 @@ impl<'a> Location<'a> {
     ///
     /// let fixed_location = get_just_one_location();
     /// assert_eq!(fixed_location.file(), file!());
-    /// assert_eq!(fixed_location.line(), 15);
+    /// assert_eq!(fixed_location.line(), 14);
     /// assert_eq!(fixed_location.column(), 5);
     ///
     /// // running the same untracked function in a different location gives us the same result
@@ -217,7 +216,7 @@ impl<'a> Location<'a> {
     ///
     /// let this_location = get_caller_location();
     /// assert_eq!(this_location.file(), file!());
-    /// assert_eq!(this_location.line(), 29);
+    /// assert_eq!(this_location.line(), 28);
     /// assert_eq!(this_location.column(), 21);
     ///
     /// // running the tracked function in a different location produces a different value
@@ -226,13 +225,8 @@ impl<'a> Location<'a> {
     /// assert_ne!(this_location.line(), another_location.line());
     /// assert_ne!(this_location.column(), another_location.column());
     /// ```
-    // FIXME: When stabilizing this method, please also update the documentation
-    // of `intrinsics::caller_location`.
-    #[unstable(
-        feature = "track_caller",
-        reason = "uses #[track_caller] which is not yet stable",
-        issue = "47809"
-    )]
+    #[stable(feature = "track_caller", since = "1.46.0")]
+    #[rustc_const_unstable(feature = "const_caller_location", issue = "47809")]
     #[track_caller]
     pub const fn caller() -> &'static Location<'static> {
         crate::intrinsics::caller_location()

src/libcore/panic.rs

@@ -3,8 +3,6 @@
 Erroneous code example:
 
 ```compile_fail,E0736
-#![feature(track_caller)]
-
 #[naked]
 #[track_caller]
 fn foo() {}

src/librustc_error_codes/error_codes/E0736.md

@@ -5,8 +5,6 @@ restrictions.
 Erroneous code example:
 
 ```compile_fail,E0737
-#![feature(track_caller)]
-
 #[track_caller]
 extern "C" fn foo() {}
 ```

src/librustc_error_codes/error_codes/E0737.md

@@ -3,7 +3,6 @@
 Erroneous code example:
 
 ```compile_fail,E0739
-#![feature(track_caller)]
 #[track_caller]
 struct Bar {
     a: u8,

src/librustc_error_codes/error_codes/E0739.md

@@ -5,7 +5,7 @@
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/")]
 #![feature(crate_visibility_modifier)]
 #![feature(nll)]
-#![feature(track_caller)]
+#![cfg_attr(bootstrap, feature(track_caller))]
 
 pub use emitter::ColorConfig;
 

src/librustc_errors/lib.rs

@@ -265,6 +265,9 @@ declare_features! (
     (accepted, const_if_match, "1.45.0", Some(49146), None),
     /// Allows the use of `loop` and `while` in constants.
     (accepted, const_loop, "1.45.0", Some(52000), None),
+    /// Allows `#[track_caller]` to be used which provides
+    /// accurate caller location reporting during panic (RFC 2091).
+    (accepted, track_caller, "1.46.0", Some(47809), None),
 
     // -------------------------------------------------------------------------
     // feature-group-end: accepted features

src/librustc_feature/accepted.rs

@@ -494,10 +494,6 @@ declare_features! (
     /// Allows the use of raw-dylibs (RFC 2627).
     (active, raw_dylib, "1.40.0", Some(58713), None),
 
-    /// Allows `#[track_caller]` to be used which provides
-    /// accurate caller location reporting during panic (RFC 2091).
-    (active, track_caller, "1.40.0", Some(47809), None),
-
     /// Allows making `dyn Trait` well-formed even if `Trait` is not object safe.
     /// In that case, `dyn Trait: Trait` does not hold. Moreover, coercions and
     /// casts in safe Rust to `dyn Trait` for such a `Trait` is also forbidden.