syntax: Implement #![no_core]

This commit is an implementation of [RFC 1184][rfc] which tweaks the behavior of
the `#![no_std]` attribute and adds a new `#![no_core]` attribute. The
`#![no_std]` attribute now injects `extern crate core` at the top of the crate
as well as the libcore prelude into all modules (in the same manner as the
standard library's prelude). The `#![no_core]` attribute disables both std and
core injection.

[rfc]: https://github.com/rust-lang/rfcs/pull/1184

7 files changed, 11 insertions, 8 deletions

diff --git a/src/libcore/num/f32.rs b/src/libcore/num/f32.rs
index 6b4424093b4..d0e6d4fa49c 100644
--- a/src/libcore/num/f32.rs
+++ b/src/libcore/num/f32.rs
@@ -15,7 +15,7 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
-use prelude::*;
+use prelude::v1::*;
 
 use intrinsics;
 use mem;
diff --git a/src/libcore/num/f64.rs b/src/libcore/num/f64.rs
index fa7aa2ab5ce..bf7da04f995 100644
--- a/src/libcore/num/f64.rs
+++ b/src/libcore/num/f64.rs
@@ -15,7 +15,7 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
-use prelude::*;
+use prelude::v1::*;
 
 use intrinsics;
 use mem;
diff --git a/src/libcore/num/flt2dec/bignum.rs b/src/libcore/num/flt2dec/bignum.rs
index 4f373c16f7c..1e39c53f9e0 100644
--- a/src/libcore/num/flt2dec/bignum.rs
+++ b/src/libcore/num/flt2dec/bignum.rs
@@ -21,7 +21,8 @@
 
 #![macro_use]
 
-use prelude::*;
+use prelude::v1::*;
+
 use mem;
 use intrinsics;
 
@@ -351,7 +352,7 @@ define_bignum!(Big32x36: type=Digit32, n=36);
 // this one is used for testing only.
 #[doc(hidden)]
 pub mod tests {
-    use prelude::*;
+    use prelude::v1::*;
     define_bignum!(Big8x3: type=u8, n=3);
 }
 
diff --git a/src/libcore/num/flt2dec/decoder.rs b/src/libcore/num/flt2dec/decoder.rs
index f98bc11a315..a292ffa2e9d 100644
--- a/src/libcore/num/flt2dec/decoder.rs
+++ b/src/libcore/num/flt2dec/decoder.rs
@@ -10,7 +10,7 @@
 
 //! Decodes a floating-point value into individual parts and error ranges.
 
-use prelude::*;
+use prelude::v1::*;
 
 use {f32, f64};
 use num::{Float, FpCategory};
diff --git a/src/libcore/num/flt2dec/mod.rs b/src/libcore/num/flt2dec/mod.rs
index f3a7e8f09a9..40fa2a5563d 100644
--- a/src/libcore/num/flt2dec/mod.rs
+++ b/src/libcore/num/flt2dec/mod.rs
@@ -129,7 +129,7 @@ functions.
 #![unstable(feature = "flt2dec",
             reason = "internal routines only exposed for testing")]
 
-use prelude::*;
+use prelude::v1::*;
 use i16;
 use num::Float;
 use slice::bytes;
diff --git a/src/libcore/num/flt2dec/strategy/dragon.rs b/src/libcore/num/flt2dec/strategy/dragon.rs
index a1137789371..b03286ddd0d 100644
--- a/src/libcore/num/flt2dec/strategy/dragon.rs
+++ b/src/libcore/num/flt2dec/strategy/dragon.rs
@@ -15,7 +15,8 @@ Almost direct (but slightly optimized) Rust translation of Figure 3 of [1].
     quickly and accurately. SIGPLAN Not. 31, 5 (May. 1996), 108-116.
 */
 
-use prelude::*;
+use prelude::v1::*;
+
 use num::Float;
 use cmp::Ordering;
 
diff --git a/src/libcore/num/flt2dec/strategy/grisu.rs b/src/libcore/num/flt2dec/strategy/grisu.rs
index 54d3c92eca4..390920a354c 100644
--- a/src/libcore/num/flt2dec/strategy/grisu.rs
+++ b/src/libcore/num/flt2dec/strategy/grisu.rs
@@ -16,7 +16,8 @@ Rust adaptation of Grisu3 algorithm described in [1]. It uses about
     accurately with integers. SIGPLAN Not. 45, 6 (June 2010), 233-243.
 */
 
-use prelude::*;
+use prelude::v1::*;
+
 use num::Float;
 
 use num::flt2dec::{Decoded, MAX_SIG_DIGITS, round_up};