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

Diff for: 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))
     }

Diff for: 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;
     }

Diff for: 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;

Diff for: 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;
 }

Diff for: 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)
 }

Diff for: 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;
     }

Diff for: 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;

Diff for: 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()
         }
     }

Diff for: 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;
         }

Diff for: src/libstd/sys/windows/backtrace/printing/msvc.rs

@@ -10,7 +10,7 @@
 
 use ffi::CStr;
 use io;
-use libc::{c_ulong, c_int, c_char};
+use libc::{c_ulong, c_char};
 use mem;
 use sys::c;
 use sys::backtrace::BacktraceContext;
@@ -59,7 +59,7 @@ pub fn foreach_symbol_fileline<F>(frame: Frame,
                                   mut f: F,
                                   context: &BacktraceContext)
     -> io::Result<bool>
-    where F: FnMut(&[u8], c_int) -> io::Result<()>
+    where F: FnMut(&[u8], u32) -> io::Result<()>
 {
     let SymGetLineFromAddr64 = sym!(&context.dbghelp,
                                     "SymGetLineFromAddr64",
@@ -76,7 +76,7 @@ pub fn foreach_symbol_fileline<F>(frame: Frame,
                                        &mut line);
         if ret == c::TRUE {
             let name = CStr::from_ptr(line.Filename).to_bytes();
-            f(name, line.LineNumber as c_int)?;
+            f(name, line.LineNumber as u32)?;
         }
         Ok(false)
     }

Diff for: src/libstd/sys/windows/mod.rs

@@ -17,6 +17,7 @@ use os::windows::ffi::{OsStrExt, OsStringExt};
 use path::PathBuf;
 use time::Duration;
 
+pub use libc::strlen;
 pub use self::rand::hashmap_random_keys;
 
 #[macro_use] pub mod compat;

Diff for: src/libstd/sys/windows/thread.rs

@@ -52,7 +52,7 @@ impl Thread {
         };
 
         extern "system" fn thread_start(main: *mut c_void) -> c::DWORD {
-            unsafe { start_thread(main); }
+            unsafe { start_thread(main as *mut u8); }
             0
         }
     }

Diff for: src/libstd/sys_common/backtrace.rs

@@ -14,7 +14,6 @@
 use env;
 use io::prelude::*;
 use io;
-use libc;
 use str;
 use sync::atomic::{self, Ordering};
 use path::{self, Path};
@@ -39,9 +38,9 @@ pub const HEX_WIDTH: usize = 10;
 #[derive(Debug, Copy, Clone)]
 pub struct Frame {
     /// Exact address of the call that failed.
-    pub exact_position: *const libc::c_void,
+    pub exact_position: *const u8,
     /// Address of the enclosing function.
-    pub symbol_addr: *const libc::c_void,
+    pub symbol_addr: *const u8,
 }
 
 /// Max number of frames to print.
@@ -201,8 +200,10 @@ fn output(w: &mut Write, idx: usize, frame: Frame,
 ///
 /// See also `output`.
 #[allow(dead_code)]
-fn output_fileline(w: &mut Write, file: &[u8], line: libc::c_int,
-                       format: PrintFormat) -> io::Result<()> {
+fn output_fileline(w: &mut Write,
+                   file: &[u8],
+                   line: u32,
+                   format: PrintFormat) -> io::Result<()> {
     // prior line: "  ##: {:2$} - func"
     w.write_all(b"")?;
     match format {

Diff for: src/libstd/sys_common/gnu/libbacktrace.rs

@@ -20,13 +20,13 @@ use sys_common::backtrace::Frame;
 pub fn foreach_symbol_fileline<F>(frame: Frame,
                                   mut f: F,
                                   _: &BacktraceContext) -> io::Result<bool>
-where F: FnMut(&[u8], libc::c_int) -> io::Result<()>
+where F: FnMut(&[u8], u32) -> io::Result<()>
 {
     // pcinfo may return an arbitrary number of file:line pairs,
     // in the order of stack trace (i.e. inlined calls first).
     // in order to avoid allocation, we stack-allocate a fixed size of entries.
     const FILELINE_SIZE: usize = 32;
-    let mut fileline_buf = [(ptr::null(), -1); FILELINE_SIZE];
+    let mut fileline_buf = [(ptr::null(), !0); FILELINE_SIZE];
     let ret;
     let fileline_count = {
         let state = unsafe { init_state() };
@@ -136,7 +136,7 @@ extern {
 // helper callbacks
 ////////////////////////////////////////////////////////////////////////
 
-type FileLine = (*const libc::c_char, libc::c_int);
+type FileLine = (*const libc::c_char, u32);
 
 extern fn error_cb(_data: *mut libc::c_void, _msg: *const libc::c_char,
                    _errnum: libc::c_int) {
@@ -162,7 +162,7 @@ extern fn pcinfo_cb(data: *mut libc::c_void,
         // if the buffer is not full, add file:line to the buffer
         // and adjust the buffer for next possible calls to pcinfo_cb.
         if !buffer.is_empty() {
-            buffer[0] = (filename, lineno);
+            buffer[0] = (filename, lineno as u32);
             unsafe { ptr::write(slot, &mut buffer[1..]); }
         }
     }

Diff for: src/libstd/sys_common/thread.rs

@@ -10,12 +10,11 @@
 
 use env;
 use alloc::boxed::FnBox;
-use libc;
 use sync::atomic::{self, Ordering};
 use sys::stack_overflow;
 use sys::thread as imp;
 
-pub unsafe fn start_thread(main: *mut libc::c_void) {
+pub unsafe fn start_thread(main: *mut u8) {
     // Next, set up our stack overflow handler which may get triggered if we run
     // out of stack.
     let _handler = stack_overflow::Handler::new();