Auto merge of #51496 - petrochenkov:mhelper2, r=nikomatsakis

Implement `#[macro_export(local_inner_macros)]` (a solution for the macro helper import problem)

Implement a solution for the macro helper issue discussed in https://github.com/rust-lang/rust/issues/35896 as described in https://github.com/rust-lang/rust/issues/35896#issuecomment-395977901.

Macros exported from libraries can be marked with `#[macro_export(local_inner_macros)]` and this annotation changes how nested macros in them are resolved.

If we have a fn-like macro call `ident!(...)` and `ident` comes from a `macro_rules!` macro marked with  `#[macro_export(local_inner_macros)]` then it's replaced with `$crate::ident!(...)` and resolved as such (`$crate` gets the same context as `ident`).

diff --git a/src/libcore/num/mod.rs b/src/libcore/num/mod.rs
index 1168126c47c93a538c4a35a304533a0e3c20302b..7e2dd304d7f5a23b2fa2644d949eaf2711c9c1d5 100644 (file)
--- a/src/libcore/num/mod.rs
+++ b/src/libcore/num/mod.rs
@@ -1996,12 +1996,10 @@ pub fn is_negative(self) -> bool { self < 0 }
         /// # Examples
         ///
         /// ```
-        /// #![feature(int_to_from_bytes)]
-        ///
         /// let bytes = i32::min_value().to_be().to_bytes();
         /// assert_eq!(bytes, [0x80, 0, 0, 0]);
         /// ```
-        #[unstable(feature = "int_to_from_bytes", issue = "49792")]
+        #[stable(feature = "int_to_from_bytes", since = "1.29.0")]
         #[inline]
         pub fn to_bytes(self) -> [u8; mem::size_of::<Self>()] {
             unsafe { mem::transmute(self) }
@@ -2018,12 +2016,10 @@ pub fn is_negative(self) -> bool { self < 0 }
         /// # Examples
         ///
         /// ```
-        /// #![feature(int_to_from_bytes)]
-        ///
         /// let int = i32::from_be(i32::from_bytes([0x80, 0, 0, 0]));
         /// assert_eq!(int, i32::min_value());
         /// ```
-        #[unstable(feature = "int_to_from_bytes", issue = "49792")]
+        #[stable(feature = "int_to_from_bytes", since = "1.29.0")]
         #[inline]
         pub fn from_bytes(bytes: [u8; mem::size_of::<Self>()]) -> Self {
             unsafe { mem::transmute(bytes) }
@@ -3702,12 +3698,10 @@ pub fn wrapping_next_power_of_two(self) -> Self {
         /// # Examples
         ///
         /// ```
-        /// #![feature(int_to_from_bytes)]
-        ///
         /// let bytes = 0x1234_5678_u32.to_be().to_bytes();
         /// assert_eq!(bytes, [0x12, 0x34, 0x56, 0x78]);
         /// ```
-        #[unstable(feature = "int_to_from_bytes", issue = "49792")]
+        #[stable(feature = "int_to_from_bytes", since = "1.29.0")]
         #[inline]
         pub fn to_bytes(self) -> [u8; mem::size_of::<Self>()] {
             unsafe { mem::transmute(self) }
@@ -3724,12 +3718,10 @@ pub fn wrapping_next_power_of_two(self) -> Self {
         /// # Examples
         ///
         /// ```
-        /// #![feature(int_to_from_bytes)]
-        ///
         /// let int = u32::from_be(u32::from_bytes([0x12, 0x34, 0x56, 0x78]));
         /// assert_eq!(int, 0x1234_5678_u32);
         /// ```
-        #[unstable(feature = "int_to_from_bytes", issue = "49792")]
+        #[stable(feature = "int_to_from_bytes", since = "1.29.0")]
         #[inline]
         pub fn from_bytes(bytes: [u8; mem::size_of::<Self>()]) -> Self {
             unsafe { mem::transmute(bytes) }