Factor out platforms for which libc is empty

Author: gnzlbg

README.md

@@ -1,8 +1,7 @@
 libc
 ====
 
-A Rust library with native bindings to the types and functions commonly found on
-various systems, including libc.
+Rust wrapper over the system's `libc`.
 
 [![Build Status](https://travis-ci.org/rust-lang/libc.svg?branch=master)](https://travis-ci.org/rust-lang/libc)
 [![Build status](https://ci.appveyor.com/api/projects/status/github/rust-lang/libc?svg=true)](https://ci.appveyor.com/project/rust-lang-libs/libc)

src/common.rs

@@ -98,38 +98,37 @@
 #[cfg(all(not(cross_platform_docs), feature = "use_std"))]
 extern crate std as core;
 
-#[macro_use] mod macros;
-mod dox;
+#[macro_use]
+mod macros;
 
-/*
- * `c_void` should be defined for all targets except wasm.
- */
-#[cfg(not(all(target_arch = "wasm32", not(target_os = "emscripten"))))]
+// Targets for which `libc` should not fail to compile, but be completely empty
+// instead.
+//
+// FIXME: `libc` should just fail to compile for these targets.
 cfg_if! {
-    if #[cfg(core_cvoid)] {
-        pub use core::ffi::c_void;
+    if #[cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))] {
+        // libc is empty for wasm32-unknown-unknown ...
     } else {
-        // Use repr(u8) as LLVM expects `void*` to be the same as `i8*` to help enable
-        // more optimization opportunities around it recognizing things like
-        // malloc/free.
-        #[repr(u8)]
-        pub enum c_void {
-            // Two dummy variants so the #[repr] attribute can be used.
-            #[doc(hidden)]
-            __variant1,
-            #[doc(hidden)]
-            __variant2,
+        mod dox;
+
+        cfg_if! {
+            if #[cfg(core_cvoid)] {
+                pub use core::ffi::c_void;
+            } else {
+                // Use repr(u8) as LLVM expects `void*` to be the same as `i8*` to help enable
+                // more optimization opportunities around it recognizing things like
+                // malloc/free.
+                #[repr(u8)]
+                pub enum c_void {
+                    // Two dummy variants so the #[repr] attribute can be used.
+                    #[doc(hidden)]
+                    __variant1,
+                    #[doc(hidden)]
+                    __variant2,
+                }
+            }
         }
-    }
-}
 
-cfg_if! {
-    if #[cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))] {
-        // empty ...
-    } else if #[cfg(target_os = "switch")] {
-        // On the Switch, we only define some useful universal types for
-        // convenience. Those can be found in the switch.rs file.
-    } else {
         pub type int8_t = i8;
         pub type int16_t = i16;
         pub type int32_t = i32;
@@ -284,6 +283,7 @@ cfg_if! {
 
         // These are all inline functions on android, so they end up just being entirely
         // missing on that platform.
+
         #[cfg(not(target_os = "android"))]
         extern {
             pub fn abs(i: c_int) -> c_int;
@@ -292,29 +292,29 @@ cfg_if! {
             pub fn rand() -> c_int;
             pub fn srand(seed: c_uint);
         }
-    }
-}
 
-cfg_if! {
-    if #[cfg(windows)] {
-        mod windows;
-        pub use windows::*;
-    } else if #[cfg(target_os = "redox")] {
-        mod redox;
-        pub use redox::*;
-    } else if #[cfg(target_os = "cloudabi")] {
-        mod cloudabi;
-        pub use cloudabi::*;
-    } else if #[cfg(target_os = "fuchsia")] {
-        mod fuchsia;
-        pub use fuchsia::*;
-    } else if #[cfg(target_os = "switch")] {
-        mod switch;
-        pub use switch::*;
-    } else if #[cfg(unix)] {
-        mod unix;
-        pub use unix::*;
-    } else {
-        // Unknown target_family
+        cfg_if! {
+            if #[cfg(windows)] {
+                mod windows;
+                pub use windows::*;
+            } else if #[cfg(target_os = "redox")] {
+                mod redox;
+                pub use redox::*;
+            } else if #[cfg(target_os = "cloudabi")] {
+                mod cloudabi;
+                pub use cloudabi::*;
+            } else if #[cfg(target_os = "fuchsia")] {
+                mod fuchsia;
+                pub use fuchsia::*;
+            } else if #[cfg(target_os = "switch")] {
+                mod switch;
+                pub use switch::*;
+            } else if #[cfg(unix)] {
+                mod unix;
+                pub use unix::*;
+            } else {
+                // Unknown target_family
+            }
+        }
     }
 }

src/lib.rs

@@ -1,34 +1,5 @@
 //! Switch C type definitions
 
-pub type int8_t = i8;
-pub type int16_t = i16;
-pub type int32_t = i32;
-pub type int64_t = i64;
-pub type uint8_t = u8;
-pub type uint16_t = u16;
-pub type uint32_t = u32;
-pub type uint64_t = u64;
-
-pub type c_schar = i8;
-pub type c_uchar = u8;
-pub type c_short = i16;
-pub type c_ushort = u16;
-pub type c_int = i32;
-pub type c_uint = u32;
-pub type c_float = f32;
-pub type c_double = f64;
-pub type c_longlong = i64;
-pub type c_ulonglong = u64;
-pub type intmax_t = i64;
-pub type uintmax_t = u64;
-
-pub type size_t = usize;
-pub type ptrdiff_t = isize;
-pub type intptr_t = isize;
-pub type uintptr_t = usize;
-pub type ssize_t = isize;
-
-// Arch specific
 pub type off_t = i64;
 pub type c_char = u8;
 pub type c_long = i64;