Move memory handling into string, do not use compiler_builtins for memory handling

Cargo.lock

@@ -379,7 +379,6 @@ name = "stdio"
 version = "0.1.0"
 dependencies = [
  "cbindgen 0.5.2",
- "compiler_builtins 0.1.0 (git+https://github.com/rust-lang-nursery/compiler-builtins.git)",
  "errno 0.1.0",
  "fcntl 0.1.0",
  "platform 0.1.0",
@@ -405,7 +404,6 @@ name = "string"
 version = "0.1.0"
 dependencies = [
  "cbindgen 0.5.2",
- "compiler_builtins 0.1.0 (git+https://github.com/rust-lang-nursery/compiler-builtins.git)",
  "errno 0.1.0",
  "platform 0.1.0",
  "stdlib 0.1.0",

Cargo.toml

@@ -14,7 +14,7 @@ members = ["src/crt0"]
 cc = "1.0"
 
 [dependencies]
-compiler_builtins = { git = "https://github.com/rust-lang-nursery/compiler-builtins.git", default-features = false, features = ["mem"] }
+compiler_builtins = { git = "https://github.com/rust-lang-nursery/compiler-builtins.git", default-features = false }
 ctype = { path = "src/ctype" }
 errno = { path = "src/errno" }
 fcntl = { path = "src/fcntl" }

include/bits/string.h

@@ -1,9 +0,0 @@
-#ifndef _BITS_STRING_H
-#define _BITS_STRING_H
-
-int memcmp(const void *s1, const void *s2, size_t n);
-void *memcpy(void *dest, const void *src, size_t n);
-void *memmove(void *dest, const void *src, size_t n);
-void *memset(void *s, int c, size_t n);
-
-#endif /* _BITS_STRING_H */

src/stdio/Cargo.toml

@@ -8,7 +8,6 @@ build = "build.rs"
 cbindgen = { path = "../../cbindgen" }
 
 [dependencies]
-compiler_builtins = { git = "https://github.com/rust-lang-nursery/compiler-builtins.git", default-features = false, features = ["mem"] }
 platform = { path = "../platform" }
 va_list = { path = "../../va_list", features = ["no_std"] }
 fcntl = { path = "../fcntl" }

src/stdio/src/lib.rs

@@ -1,9 +1,7 @@
 //! stdio implementation for Redox, following http://pubs.opengroup.org/onlinepubs/7908799/xsh/stdio.h.html
 
-#![feature(compiler_builtins_lib)]
 #![no_std]
 
-extern crate compiler_builtins;
 extern crate errno;
 extern crate fcntl;
 extern crate platform;

src/string/Cargo.toml

@@ -11,4 +11,3 @@ cbindgen = { path = "../../cbindgen" }
 platform = { path = "../platform" }
 stdlib = { path = "../stdlib" }
 errno = { path = "../errno" }
-compiler_builtins = { git = "https://github.com/rust-lang-nursery/compiler-builtins.git", default-features = false, features = ["mem"] }

src/string/cbindgen.toml

@@ -1,6 +1,5 @@
 sys_includes = ["stddef.h", "stdint.h"]
 include_guard = "_STRING_H"
-trailer = "#include <bits/string.h>"
 language = "C"
 
 [enum]

src/string/src/lib.rs

@@ -1,9 +1,7 @@
 //! string implementation for Redox, following http://pubs.opengroup.org/onlinepubs/7908799/xsh/string.h.html
 
-#![feature(compiler_builtins_lib)]
 #![no_std]
 
-extern crate compiler_builtins;
 extern crate errno;
 extern crate platform;
 extern crate stdlib;
@@ -21,18 +19,15 @@ pub unsafe extern "C" fn memccpy(
     c: c_int,
     n: usize,
 ) -> *mut c_void {
-    use compiler_builtins::mem::memcpy;
-    let dest = dest as *mut u8;
     let to = memchr(src, c, n);
     if to.is_null() {
         return to;
     }
-    let src = src as *mut u8;
     let dist = (to as usize) - (src as usize);
     if memcpy(dest, src, dist).is_null() {
         return ptr::null_mut();
     }
-    dest.offset(dist as isize + 1) as *mut c_void
+    (dest as *mut u8).offset(dist as isize + 1) as *mut c_void
 }
 
 #[no_mangle]
@@ -47,41 +42,75 @@ pub unsafe extern "C" fn memchr(s: *const c_void, c: c_int, n: usize) -> *mut c_
     ptr::null_mut()
 }
 
-// #[no_mangle]
-// pub extern "C" fn memcmp(
-//     s1: *const c_void,
-//     s2: *const c_void,
-//     n: usize,
-// ) -> c_int {
-//     unimplemented!();
-// }
-
-// #[no_mangle]
-// pub extern "C" fn memcpy(
-//     s1: *mut c_void,
-//     s2: *const c_void,
-//     n: usize,
-// ) -> *mut c_void {
-//     unimplemented!();
-// }
-
-// #[no_mangle]
-// pub extern "C" fn memmove(
-//     s1: *mut c_void,
-//     s2: *const c_void,
-//     n: usize,
-// ) -> *mut c_void {
-//     unimplemented!();
-// }
-
-// #[no_mangle]
-// pub extern "C" fn memset(
-//     s: *mut c_void,
-//     c: c_int,
-//     n: usize,
-// ) -> *mut c_void {
-//     unimplemented!();
-// }
+#[no_mangle]
+pub unsafe extern "C" fn memcmp(
+    s1: *const c_void,
+    s2: *const c_void,
+    n: usize,
+) -> c_int {
+    let mut i = 0;
+    while i < n {
+        let a = *(s1 as *const u8).offset(i as isize);
+        let b = *(s2 as *const u8).offset(i as isize);
+        if a != b {
+            return a as i32 - b as i32;
+        }
+        i += 1;
+    }
+    0
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn memcpy(
+    s1: *mut c_void,
+    s2: *const c_void,
+    n: usize,
+) -> *mut c_void {
+    let mut i = 0;
+    while i < n {
+        *(s1 as *mut u8).offset(i as isize) = *(s2 as *const u8).offset(i as isize);
+        i += 1;
+    }
+    s1
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn memmove(
+    s1: *mut c_void,
+    s2: *const c_void,
+    n: usize,
+) -> *mut c_void {
+    if s2 < s1 as *const c_void {
+        // copy from end
+        let mut i = n;
+        while i != 0 {
+            i -= 1;
+            *(s1 as *mut u8).offset(i as isize) = *(s2 as *const u8).offset(i as isize);
+        }
+    } else {
+        // copy from beginning
+        let mut i = 0;
+        while i < n {
+            *(s1 as *mut u8).offset(i as isize) = *(s2 as *const u8).offset(i as isize);
+            i += 1;
+        }
+    }
+    s1
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn memset(
+    s: *mut c_void,
+    c: c_int,
+    n: usize,
+) -> *mut c_void {
+    let mut i = 0;
+    while i < n {
+        *(s as *mut u8).offset(i as isize) = c as u8;
+        i += 1;
+    }
+    s
+}
 
 #[no_mangle]
 pub unsafe extern "C" fn strcat(s1: *mut c_char, s2: *const c_char) -> *mut c_char {