rustdoc: Create anchor pages for primitive types

This commit adds support in rustdoc to recognize the `#[doc(primitive = "foo")]`
attribute. This attribute indicates that the current module is the "owner" of
the primitive type `foo`. For rustdoc, this means that the doc-comment for the
module is the doc-comment for the primitive type, plus a signal to all
downstream crates that hyperlinks for primitive types will be directed at the
crate containing the `#[doc]` directive.

Additionally, rustdoc will favor crates closest to the one being documented
which "implements the primitive type". For example, documentation of libcore
links to libcore for primitive types, but documentation for libstd and beyond
all links to libstd for primitive types.

This change involves no compiler modifications, it is purely a rustdoc change.
The landing pages for the primitive types primarily serve to show a list of
implemented traits for the primitive type itself.

The primitive types documented includes both strings and slices in a semi-ad-hoc
way, but in a way that should provide at least somewhat meaningful
documentation.

Closes #14474

12 files changed, 24 insertions, 0 deletions

diff --git a/src/libcore/num/f32.rs b/src/libcore/num/f32.rs
index 75d3db596ba..cadc874891d 100644
--- a/src/libcore/num/f32.rs
+++ b/src/libcore/num/f32.rs
@@ -10,6 +10,8 @@
 
 //! Operations and constants for 32-bits floats (`f32` type)
 
+#![doc(primitive = "f32")]
+
 use intrinsics;
 use mem;
 use num::{FPNormal, FPCategory, FPZero, FPSubnormal, FPInfinite, FPNaN};
diff --git a/src/libcore/num/f64.rs b/src/libcore/num/f64.rs
index d59aad077cc..5e19015dd02 100644
--- a/src/libcore/num/f64.rs
+++ b/src/libcore/num/f64.rs
@@ -10,6 +10,8 @@
 
 //! Operations and constants for 64-bits floats (`f64` type)
 
+#![doc(primitive = "f64")]
+
 use intrinsics;
 use mem;
 use num::{FPNormal, FPCategory, FPZero, FPSubnormal, FPInfinite, FPNaN};
diff --git a/src/libcore/num/i16.rs b/src/libcore/num/i16.rs
index 957e585e71c..b821ff60a73 100644
--- a/src/libcore/num/i16.rs
+++ b/src/libcore/num/i16.rs
@@ -10,5 +10,7 @@
 
 //! Operations and constants for signed 16-bits integers (`i16` type)
 
+#![doc(primitive = "i16")]
+
 int_module!(i16, 16)
 
diff --git a/src/libcore/num/i32.rs b/src/libcore/num/i32.rs
index cfeb1020f44..a8cab1f95b0 100644
--- a/src/libcore/num/i32.rs
+++ b/src/libcore/num/i32.rs
@@ -10,5 +10,7 @@
 
 //! Operations and constants for signed 32-bits integers (`i32` type)
 
+#![doc(primitive = "i32")]
+
 int_module!(i32, 32)
 
diff --git a/src/libcore/num/i64.rs b/src/libcore/num/i64.rs
index 21ae162d4aa..6009b953bb4 100644
--- a/src/libcore/num/i64.rs
+++ b/src/libcore/num/i64.rs
@@ -10,5 +10,7 @@
 
 //! Operations and constants for signed 64-bits integers (`i64` type)
 
+#![doc(primitive = "i64")]
+
 int_module!(i64, 64)
 
diff --git a/src/libcore/num/i8.rs b/src/libcore/num/i8.rs
index b9ae13da075..b3a5557b20c 100644
--- a/src/libcore/num/i8.rs
+++ b/src/libcore/num/i8.rs
@@ -10,5 +10,7 @@
 
 //! Operations and constants for signed 8-bits integers (`i8` type)
 
+#![doc(primitive = "i8")]
+
 int_module!(i8, 8)
 
diff --git a/src/libcore/num/int.rs b/src/libcore/num/int.rs
index 4979e9e01d3..06d64e73abd 100644
--- a/src/libcore/num/int.rs
+++ b/src/libcore/num/int.rs
@@ -10,6 +10,8 @@
 
 //! Operations and constants for architecture-sized signed integers (`int` type)
 
+#![doc(primitive = "int")]
+
 #[cfg(target_word_size = "32")] int_module!(int, 32)
 #[cfg(target_word_size = "64")] int_module!(int, 64)
 
diff --git a/src/libcore/num/u16.rs b/src/libcore/num/u16.rs
index b3c701115c5..eb4bd427d51 100644
--- a/src/libcore/num/u16.rs
+++ b/src/libcore/num/u16.rs
@@ -10,4 +10,6 @@
 
 //! Operations and constants for unsigned 16-bits integers (`u16` type)
 
+#![doc(primitive = "u16")]
+
 uint_module!(u16, i16, 16)
diff --git a/src/libcore/num/u32.rs b/src/libcore/num/u32.rs
index 46f90dca833..9522b2e86ac 100644
--- a/src/libcore/num/u32.rs
+++ b/src/libcore/num/u32.rs
@@ -10,5 +10,7 @@
 
 //! Operations and constants for unsigned 32-bits integers (`u32` type)
 
+#![doc(primitive = "u32")]
+
 uint_module!(u32, i32, 32)
 
diff --git a/src/libcore/num/u64.rs b/src/libcore/num/u64.rs
index bd4333ab589..7a654f4bffa 100644
--- a/src/libcore/num/u64.rs
+++ b/src/libcore/num/u64.rs
@@ -10,5 +10,7 @@
 
 //! Operations and constants for unsigned 64-bits integer (`u64` type)
 
+#![doc(primitive = "u64")]
+
 uint_module!(u64, i64, 64)
 
diff --git a/src/libcore/num/u8.rs b/src/libcore/num/u8.rs
index 00871a1c8fa..6a42ce07e5d 100644
--- a/src/libcore/num/u8.rs
+++ b/src/libcore/num/u8.rs
@@ -10,5 +10,7 @@
 
 //! Operations and constants for unsigned 8-bits integers (`u8` type)
 
+#![doc(primitive = "u8")]
+
 uint_module!(u8, i8, 8)
 
diff --git a/src/libcore/num/uint.rs b/src/libcore/num/uint.rs
index 99ed7e10bf9..2f539fff61a 100644
--- a/src/libcore/num/uint.rs
+++ b/src/libcore/num/uint.rs
@@ -10,5 +10,7 @@
 
 //! Operations and constants for architecture-sized unsigned integers (`uint` type)
 
+#![doc(primitive = "uint")]
+
 uint_module!(uint, int, ::int::BITS)