From d62db7b1b9647bb8330841ec12975cf576eb422d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mateusz=20Miku=C5=82a?= <matti@marinelayer.io>
Date: Fri, 3 May 2019 18:16:48 +0200
Subject: [PATCH] Add memrchr()
---
src/header/string/mod.rs | 14 ++++++++++++++
tests/expected/string/mem.stdout | 1 +
tests/string/mem.c | 5 +++++
3 files changed, 20 insertions(+)
diff --git a/src/header/string/mod.rs b/src/header/string/mod.rs
index e58e5beb6..1bec129c0 100644
--- a/src/header/string/mod.rs
+++ b/src/header/string/mod.rs
@@ -107,6 +107,20 @@ pub unsafe extern "C" fn memmove(s1: *mut c_void, s2: *const c_void, n: size_t)
s1
}
+#[no_mangle]
+pub unsafe extern "C" fn memrchr(
+ haystack: *const c_void,
+ needle: c_int,
+ len: size_t,
+) -> *mut c_void {
+ let haystack = slice::from_raw_parts(haystack as *const u8, len as usize);
+
+ match memchr::memrchr(needle as u8, haystack) {
+ Some(index) => haystack[index..].as_ptr() as *mut c_void,
+ None => ptr::null_mut(),
+ }
+}
+
#[no_mangle]
pub unsafe extern "C" fn memset(s: *mut c_void, c: c_int, n: size_t) -> *mut c_void {
for i in 0..n {
diff --git a/tests/expected/string/mem.stdout b/tests/expected/string/mem.stdout
index 1d74e9a77..a6c001081 100644
--- a/tests/expected/string/mem.stdout
+++ b/tests/expected/string/mem.stdout
@@ -1,4 +1,5 @@
# mem #
Correct memchr
+Correct memrchr
Correct memccpy
Correct memcmp
diff --git a/tests/string/mem.c b/tests/string/mem.c
index 5b1b497b4..7529a3bb1 100644
--- a/tests/string/mem.c
+++ b/tests/string/mem.c
@@ -14,6 +14,11 @@ int main(void) {
exit(EXIT_FAILURE);
}
puts("Correct memchr");
+ if ((size_t)memrchr((void *)arr, 1, 100) - (size_t)arr != 50) {
+ puts("Incorrect memrchr");
+ exit(EXIT_FAILURE);
+ }
+ puts("Correct memrchr");
char arr2[51];
memset(arr2, 0, 51); // Compiler builtin, should work
memccpy((void *)arr2, (void *)arr, 1, 100);
--
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