From 4f601f4896219d9c080d51ba1494ecc5f7f9fc11 Mon Sep 17 00:00:00 2001
From: Tom Almeida <tommoa256@gmail.com>
Date: Sat, 10 Mar 2018 16:59:53 +0800
Subject: [PATCH] Added memchr and memccpy to string
---
src/string/Cargo.toml | 3 ++-
src/string/src/lib.rs | 38 ++++++++++++++++++++++++++++++++++----
tests/Makefile | 1 +
tests/mem.c | 22 ++++++++++++++++++++++
4 files changed, 59 insertions(+), 5 deletions(-)
create mode 100644 tests/mem.c
diff --git a/src/string/Cargo.toml b/src/string/Cargo.toml
index d00a3e5c..771d72c5 100644
--- a/src/string/Cargo.toml
+++ b/src/string/Cargo.toml
@@ -10,4 +10,5 @@ cbindgen = { path = "../../cbindgen" }
[dependencies]
platform = { path = "../platform" }
stdlib = { path = "../stdlib" }
-errno = { path = "../errno" }
\ No newline at end of file
+errno = { path = "../errno" }
+compiler_builtins = { git = "https://github.com/rust-lang-nursery/compiler-builtins.git", default-features = false, features = ["mem"] }
diff --git a/src/string/src/lib.rs b/src/string/src/lib.rs
index c272d921..ad98548e 100644
--- a/src/string/src/lib.rs
+++ b/src/string/src/lib.rs
@@ -1,7 +1,9 @@
//! 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;
@@ -12,13 +14,41 @@ use core::cmp;
use core::usize;
#[no_mangle]
-pub extern "C" fn memccpy(s1: *mut c_void, s2: *const c_void, c: c_int, n: usize) -> *mut c_void {
- unimplemented!();
+pub unsafe extern "C" fn memccpy(
+ dest: *mut c_void,
+ src: *const c_void,
+ c: c_int,
+ n: usize,
+) -> *mut c_void {
+ use compiler_builtins::mem::memcpy;
+ use core::mem;
+ let dest = dest as *mut u8;
+ let to = memchr(src, c, n);
+ if to as usize == 0 {
+ return to;
+ }
+ let src = src as *mut u8;
+ let dist = ((to as usize) - (src as usize)) / mem::size_of::<u8>();
+ if memcpy(dest, src, dist) as usize > 0 {
+ return dest.offset(dist as isize) as *mut c_void;
+ }
+ 0usize as *mut c_void
}
#[no_mangle]
-pub extern "C" fn memchr(s: *const c_void, c: c_int, n: usize) -> *mut c_void {
- unimplemented!();
+pub unsafe extern "C" fn memchr(s: *const c_void, c: c_int, n: usize) -> *mut c_void {
+ let s = s as *mut u8;
+ let c = c as u8;
+ let mut i = 0;
+ loop {
+ if *s.offset(i as isize) == c {
+ return s.offset(i as isize) as *mut c_void;
+ }
+ i += 1;
+ if i == n {
+ return 0usize as *mut c_void;
+ }
+ }
}
// #[no_mangle]
diff --git a/tests/Makefile b/tests/Makefile
index ae73d603..18061472 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -16,6 +16,7 @@ BINS=\
getid \
link \
math \
+ mem \
pipe \
printf \
rmdir \
diff --git a/tests/mem.c b/tests/mem.c
new file mode 100644
index 00000000..0faa781f
--- /dev/null
+++ b/tests/mem.c
@@ -0,0 +1,22 @@
+#include <stdio.h>
+#include <string.h>
+
+int main(int argc, char ** argv) {
+ printf("# mem #\n");
+ char arr[100];
+ memset(arr, 0, 100); // Compiler builtin, should work
+ arr[50] = 1;
+ if ((size_t)memchr((void *)arr, 1, 100) - (size_t)arr != 50) {
+ printf("Incorrect memchr\n");
+ exit(1);
+ }
+ printf("Correct memchr\n");
+ char arr2[51];
+ memset(arr2, 0, 51); // Compiler builtin, should work
+ memccpy((void *)arr2, (void *)arr, 1, 100);
+ if (arr[50] != 1) {
+ printf("Incorrect memccpy\n");
+ exit(1);
+ }
+ printf("Correct memccpy\n");
+}
--
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