std: Move the `cmath` module into the `sys` module

This commit moves the `f32::cmath` and `f64::cmath` modules into the
`sys` module. Note that these are not publicly exported modules, simply
implementation details. These modules are already platform-specific with
shims on MSVC and this is mostly just a reflection of that reality. This
should also help cut down on `#[cfg]` traffic if platforms are brought on
which don't directly support these functions.

2 files changed, 104 insertions, 0 deletions

diff --git a/src/libstd/sys/windows/cmath.rs b/src/libstd/sys/windows/cmath.rs
new file mode 100644
index 00000000000..b665a2c9ba4
--- /dev/null
+++ b/src/libstd/sys/windows/cmath.rs
@@ -0,0 +1,103 @@
+// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![cfg(not(test))]
+
+use libc::{c_float, c_double};
+
+#[link_name = "m"]
+extern {
+    pub fn acos(n: c_double) -> c_double;
+    pub fn asin(n: c_double) -> c_double;
+    pub fn atan(n: c_double) -> c_double;
+    pub fn atan2(a: c_double, b: c_double) -> c_double;
+    pub fn cbrt(n: c_double) -> c_double;
+    pub fn cbrtf(n: c_float) -> c_float;
+    pub fn cosh(n: c_double) -> c_double;
+    pub fn expm1(n: c_double) -> c_double;
+    pub fn expm1f(n: c_float) -> c_float;
+    pub fn fdim(a: c_double, b: c_double) -> c_double;
+    pub fn fdimf(a: c_float, b: c_float) -> c_float;
+    #[cfg_attr(target_env = "msvc", link_name = "_hypot")]
+    pub fn hypot(x: c_double, y: c_double) -> c_double;
+    #[cfg_attr(target_env = "msvc", link_name = "_hypotf")]
+    pub fn hypotf(x: c_float, y: c_float) -> c_float;
+    pub fn log1p(n: c_double) -> c_double;
+    pub fn log1pf(n: c_float) -> c_float;
+    pub fn sinh(n: c_double) -> c_double;
+    pub fn tan(n: c_double) -> c_double;
+    pub fn tanh(n: c_double) -> c_double;
+}
+
+pub use self::shims::*;
+
+#[cfg(not(target_env = "msvc"))]
+mod shims {
+    use libc::c_float;
+
+    extern {
+        pub fn acosf(n: c_float) -> c_float;
+        pub fn asinf(n: c_float) -> c_float;
+        pub fn atan2f(a: c_float, b: c_float) -> c_float;
+        pub fn atanf(n: c_float) -> c_float;
+        pub fn coshf(n: c_float) -> c_float;
+        pub fn sinhf(n: c_float) -> c_float;
+        pub fn tanf(n: c_float) -> c_float;
+        pub fn tanhf(n: c_float) -> c_float;
+    }
+}
+
+// On MSVC these functions aren't defined, so we just define shims which promote
+// everything fo f64, perform the calculation, and then demote back to f32.
+// While not precisely correct should be "correct enough" for now.
+#[cfg(target_env = "msvc")]
+mod shims {
+    use libc::c_float;
+
+    #[inline]
+    pub unsafe fn acosf(n: c_float) -> c_float {
+        f64::acos(n as f64) as c_float
+    }
+
+    #[inline]
+    pub unsafe fn asinf(n: c_float) -> c_float {
+        f64::asin(n as f64) as c_float
+    }
+
+    #[inline]
+    pub unsafe fn atan2f(n: c_float, b: c_float) -> c_float {
+        f64::atan2(n as f64, b as f64) as c_float
+    }
+
+    #[inline]
+    pub unsafe fn atanf(n: c_float) -> c_float {
+        f64::atan(n as f64) as c_float
+    }
+
+    #[inline]
+    pub unsafe fn coshf(n: c_float) -> c_float {
+        f64::cosh(n as f64) as c_float
+    }
+
+    #[inline]
+    pub unsafe fn sinhf(n: c_float) -> c_float {
+        f64::sinh(n as f64) as c_float
+    }
+
+    #[inline]
+    pub unsafe fn tanf(n: c_float) -> c_float {
+        f64::tan(n as f64) as c_float
+    }
+
+    #[inline]
+    pub unsafe fn tanhf(n: c_float) -> c_float {
+        f64::tanh(n as f64) as c_float
+    }
+}
diff --git a/src/libstd/sys/windows/mod.rs b/src/libstd/sys/windows/mod.rs
index ab8e155331e..180b55a66e3 100644
--- a/src/libstd/sys/windows/mod.rs
+++ b/src/libstd/sys/windows/mod.rs
@@ -25,6 +25,7 @@ pub mod args;
 #[cfg(feature = "backtrace")]
 pub mod backtrace;
 pub mod c;
+pub mod cmath;
 pub mod condvar;
 #[cfg(feature = "backtrace")]
 pub mod dynamic_lib;