std: Avoid use of libc in portable modules

This commit removes usage of the `libc` crate in "portable" modules like
those at the top level and `sys_common`. Instead common types like `*mut
u8` or `u32` are used instead of `*mut c_void` or `c_int` as well as
switching to platform-specific functions like `sys::strlen` instead of
`libc::strlen`.

Author: alexcrichton

src/libstd/ffi/c_str.rs

@@ -14,14 +14,14 @@ use cmp::Ordering;
 use error::Error;
 use fmt::{self, Write};
 use io;
-use libc;
 use mem;
 use memchr;
 use ops;
 use os::raw::c_char;
 use ptr;
 use slice;
 use str::{self, Utf8Error};
+use sys;
 
 /// A type representing an owned, C-compatible, nul-terminated string with no nul bytes in the
 /// middle.
@@ -404,7 +404,7 @@ impl CString {
     /// ```
     #[stable(feature = "cstr_memory", since = "1.4.0")]
     pub unsafe fn from_raw(ptr: *mut c_char) -> CString {
-        let len = libc::strlen(ptr) + 1; // Including the NUL byte
+        let len = sys::strlen(ptr) + 1; // Including the NUL byte
         let slice = slice::from_raw_parts_mut(ptr, len as usize);
         CString { inner: Box::from_raw(slice as *mut [c_char] as *mut [u8]) }
     }
@@ -861,7 +861,7 @@ impl CStr {
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     pub unsafe fn from_ptr<'a>(ptr: *const c_char) -> &'a CStr {
-        let len = libc::strlen(ptr);
+        let len = sys::strlen(ptr);
         let ptr = ptr as *const u8;
         CStr::from_bytes_with_nul_unchecked(slice::from_raw_parts(ptr, len as usize + 1))
     }

src/libstd/sys/redox/backtrace/tracing.rs

@@ -96,8 +96,8 @@ extern fn trace_fn(ctx: *mut uw::_Unwind_Context,
 
     if cx.idx < cx.frames.len() {
         cx.frames[cx.idx] = Frame {
-            symbol_addr: symaddr,
-            exact_position: ip,
+            symbol_addr: symaddr as *mut u8,
+            exact_position: ip as *mut u8,
         };
         cx.idx += 1;
     }

src/libstd/sys/redox/mod.rs

@@ -12,6 +12,7 @@
 
 use io::{self, ErrorKind};
 
+pub use libc::strlen;
 pub use self::rand::hashmap_random_keys;
 
 pub mod args;

src/libstd/sys/unix/backtrace/printing/dladdr.rs

@@ -22,7 +22,7 @@ pub fn resolve_symname<F>(frame: Frame,
 {
     unsafe {
         let mut info: Dl_info = intrinsics::init();
-        let symname = if dladdr(frame.exact_position, &mut info) == 0 ||
+        let symname = if dladdr(frame.exact_position as *mut _, &mut info) == 0 ||
                          info.dli_sname.is_null() {
             None
         } else {
@@ -41,6 +41,5 @@ struct Dl_info {
 }
 
 extern {
-    fn dladdr(addr: *const libc::c_void,
-              info: *mut Dl_info) -> libc::c_int;
+    fn dladdr(addr: *const libc::c_void, info: *mut Dl_info) -> libc::c_int;
 }

src/libstd/sys/unix/backtrace/printing/mod.rs

@@ -20,7 +20,7 @@ pub use self::dladdr::resolve_symname;
 #[cfg(target_os = "emscripten")]
 pub fn foreach_symbol_fileline<F>(_: Frame, _: F, _: &BacktraceContext) -> io::Result<bool>
 where
-    F: FnMut(&[u8], ::libc::c_int) -> io::Result<()>
+    F: FnMut(&[u8], u32) -> io::Result<()>
 {
     Ok(false)
 }

src/libstd/sys/unix/backtrace/tracing/backtrace_fn.rs

@@ -36,8 +36,8 @@ pub fn unwind_backtrace(frames: &mut [Frame])
     } as usize;
     for (from, to) in raw_frames.iter().zip(frames.iter_mut()).take(nb_frames) {
         *to = Frame {
-            exact_position: *from,
-            symbol_addr: *from,
+            exact_position: *from as *mut u8,
+            symbol_addr: *from as *mut u8,
         };
     }
     Ok((nb_frames as usize, BacktraceContext))

src/libstd/sys/unix/backtrace/tracing/gcc_s.rs

@@ -96,8 +96,8 @@ extern fn trace_fn(ctx: *mut uw::_Unwind_Context,
 
     if cx.idx < cx.frames.len() {
         cx.frames[cx.idx] = Frame {
-            symbol_addr: symaddr,
-            exact_position: ip,
+            symbol_addr: symaddr as *mut u8,
+            exact_position: ip as *mut u8,
         };
         cx.idx += 1;
     }

src/libstd/sys/unix/mod.rs

@@ -30,6 +30,7 @@ use libc;
 #[cfg(all(not(dox), target_os = "l4re"))]      pub use os::linux as platform;
 
 pub use self::rand::hashmap_random_keys;
+pub use libc::strlen;
 
 #[macro_use]
 pub mod weak;

src/libstd/sys/unix/thread.rs

@@ -87,7 +87,7 @@ impl Thread {
         };
 
         extern fn thread_start(main: *mut libc::c_void) -> *mut libc::c_void {
-            unsafe { start_thread(main); }
+            unsafe { start_thread(main as *mut u8); }
             ptr::null_mut()
         }
     }

src/libstd/sys/windows/backtrace/mod.rs

@@ -95,8 +95,8 @@ pub fn unwind_backtrace(frames: &mut [Frame])
                frame.AddrReturn.Offset == 0 { break }
 
             frames[i] = Frame {
-                symbol_addr: (addr - 1) as *const c_void,
-                exact_position: (addr - 1) as *const c_void,
+                symbol_addr: (addr - 1) as *const u8,
+                exact_position: (addr - 1) as *const u8,
             };
             i += 1;
         }