Make assert more hygienic

include/assert.h → include/bits/assert.h

-#ifndef _ASSERT_H
-#define _ASSERT_H
+#ifndef _BITS_ASSERT_H
+#define _BITS_ASSERT_H
 
 #ifdef NDEBUG
 # define assert(cond)
 #else
-# include <stdio.h>
 # define assert(cond) if (!(cond)) { \
-    fprintf(stderr, "%s: %s:%d: Assertion `%s` failed.\n", __func__, __FILE__, __LINE__, #cond); \
-    abort(); \
-    }
+    __assert(__func__, __FILE__, __LINE__, #cond); \
+  }
 #endif
 
 #endif

src/header/assert/cbindgen.toml

+sys_includes = ["bits/assert.h"]
+include_guard = "_ASSERT_H"
+language = "C"
+style = "Tag"
+
+[enum]
+prefix_with_name = true

src/header/assert/mod.rs

+//! assert implementation for Redox, following http://pubs.opengroup.org/onlinepubs/7908799/xsh/assert.h.html
+
+use c_str::CStr;
+use core::fmt::Write;
+use header::{stdio, stdlib};
+use platform;
+use platform::types::*;
+
+#[no_mangle]
+pub unsafe extern "C" fn __assert(func: *const c_char, file: *const c_char, line: c_int, cond: *const c_char) {
+    let func = CStr::from_ptr(func).to_str().unwrap();
+    let file = CStr::from_ptr(file).to_str().unwrap();
+    let cond = CStr::from_ptr(cond).to_str().unwrap();
+
+    write!(*stdio::stderr, "{}: {}:{}: Assertion `{}` failed.\n", func, file, line, cond).unwrap();
+    stdlib::abort();
+}

src/header/mod.rs

 pub mod aio;
 pub mod arpa_inet;
+pub mod assert;
 pub mod ctype;
 pub mod dirent;
 pub mod errno;