From 18283feac1ba5e1bc8f3710272de1a842de5c8d8 Mon Sep 17 00:00:00 2001
From: Tom Almeida <tommoa256@gmail.com>
Date: Sat, 10 Mar 2018 22:58:35 +0800
Subject: [PATCH] Added implementations of strchr, strcspn and strspn
---
src/string/src/lib.rs | 67 ++++++++++++++++++++++++++++++++++++++----
tests/.gitignore | 3 ++
tests/Makefile | 3 ++
tests/string/strchr.c | 10 +++++++
tests/string/strcspn.c | 9 ++++++
tests/string/strspn.c | 10 +++++++
6 files changed, 96 insertions(+), 6 deletions(-)
create mode 100644 tests/string/strchr.c
create mode 100644 tests/string/strcspn.c
create mode 100644 tests/string/strspn.c
diff --git a/src/string/src/lib.rs b/src/string/src/lib.rs
index a3d454fe7..7914b57ce 100644
--- a/src/string/src/lib.rs
+++ b/src/string/src/lib.rs
@@ -90,8 +90,19 @@ pub unsafe extern "C" fn strcat(s1: *mut c_char, s2: *const c_char) -> *mut c_ch
}
#[no_mangle]
-pub extern "C" fn strchr(s: *const c_char, c: c_int) -> *mut c_char {
- unimplemented!();
+pub unsafe extern "C" fn strchr(s: *const c_char, c: c_int) -> *mut c_char {
+ let c = c as i8;
+ let mut i = 0;
+ loop {
+ let cur = *s.offset(i);
+ if cur == c {
+ return s.offset(i) as *mut c_char;
+ }
+ if cur == 0 {
+ return ptr::null_mut();
+ }
+ i += 1;
+ }
}
#[no_mangle]
@@ -110,8 +121,30 @@ pub unsafe extern "C" fn strcpy(s1: *mut c_char, s2: *const c_char) -> *mut c_ch
}
#[no_mangle]
-pub extern "C" fn strcspn(s1: *const c_char, s2: *const c_char) -> c_ulong {
- unimplemented!();
+pub unsafe extern "C" fn strcspn(s1: *const c_char, s2: *const c_char) -> c_ulong {
+ use core::mem;
+
+ let s1 = s1 as *const u8;
+ let s2 = s2 as *const u8;
+
+ // The below logic is effectively ripped from the musl implementation
+
+ let mut byteset = [0u8; 32/mem::size_of::<usize>()];
+
+ let mut i = 0;
+ while *s2.offset(i) != 0 {
+ byteset[(*s2.offset(i) as usize)/(8*mem::size_of::<usize>())] |= 1 << (*s2.offset(i) as usize % (8*mem::size_of::<usize>()));
+ i += 1;
+ }
+
+ i = 0; // reset
+ while *s2.offset(i) != 0 {
+ if byteset[(*s2.offset(i) as usize)/(8*mem::size_of::<usize>())] & 1 << (*s2.offset(i) as usize % (8*mem::size_of::<usize>())) > 0 {
+ break;
+ }
+ i += 1;
+ }
+ i as u64
}
#[no_mangle]
@@ -228,8 +261,30 @@ pub extern "C" fn strrchr(s: *const c_char, c: c_int) -> *mut c_char {
}
#[no_mangle]
-pub extern "C" fn strspn(s1: *const c_char, s2: *const c_char) -> c_ulong {
- unimplemented!();
+pub unsafe extern "C" fn strspn(s1: *const c_char, s2: *const c_char) -> c_ulong {
+ use core::mem;
+
+ let s1 = s1 as *const u8;
+ let s2 = s2 as *const u8;
+
+ // The below logic is effectively ripped from the musl implementation
+
+ let mut byteset = [0u8; 32/mem::size_of::<usize>()];
+
+ let mut i = 0;
+ while *s2.offset(i) != 0 {
+ byteset[(*s2.offset(i) as usize)/(8*mem::size_of::<usize>())] |= 1 << (*s2.offset(i) as usize % (8*mem::size_of::<usize>()));
+ i += 1;
+ }
+
+ i = 0; // reset
+ while *s2.offset(i) != 0 {
+ if byteset[(*s2.offset(i) as usize)/(8*mem::size_of::<usize>())] & 1 << (*s2.offset(i) as usize % (8*mem::size_of::<usize>())) < 1 {
+ break;
+ }
+ i += 1;
+ }
+ i as u64
}
#[no_mangle]
diff --git a/tests/.gitignore b/tests/.gitignore
index 0c582647b..929fcc62d 100644
--- a/tests/.gitignore
+++ b/tests/.gitignore
@@ -30,5 +30,8 @@
/sprintf
/stdlib/strtol
/string/strncmp
+/string/strcspn
+/string/strchr
+/string/strspn
/unlink
/write
diff --git a/tests/Makefile b/tests/Makefile
index 0726ba101..49c313a55 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -25,6 +25,9 @@ BINS=\
sprintf \
stdlib/strtol \
string/strncmp \
+ string/strcspn \
+ string/strchr \
+ string/strspn \
unlink \
write
diff --git a/tests/string/strchr.c b/tests/string/strchr.c
new file mode 100644
index 000000000..929c22bed
--- /dev/null
+++ b/tests/string/strchr.c
@@ -0,0 +1,10 @@
+#include <string.h>
+#include <stdio.h>
+
+int main(int argc, char* argv[]) {
+ printf("%s\n", strchr("hello", 'e')); // should be ello
+ printf("%s\n", strchr("world", 'l')); // should be ld
+ printf("%s\n", strchr("world", 0)); // should be ''
+
+ return 0;
+}
diff --git a/tests/string/strcspn.c b/tests/string/strcspn.c
new file mode 100644
index 000000000..fa433d7e4
--- /dev/null
+++ b/tests/string/strcspn.c
@@ -0,0 +1,9 @@
+#include <string.h>
+#include <stdio.h>
+
+int main(int argc, char* argv[]) {
+ printf("%ld\n", strcspn("hello", "world")); // should be 2
+ printf("%ld\n", strcspn("banana", "world")); // should be 6
+
+ return 0;
+}
diff --git a/tests/string/strspn.c b/tests/string/strspn.c
new file mode 100644
index 000000000..9e4fc70c5
--- /dev/null
+++ b/tests/string/strspn.c
@@ -0,0 +1,10 @@
+#include <string.h>
+#include <stdio.h>
+
+int main(int argc, char* argv[]) {
+ printf("%lu\n", strspn("hello", "hello")); // should be 5
+ printf("%lu\n", strspn("world", "wendy")); // should be 1
+ printf("%lu\n", strspn("banana", "apple")); // should be 0
+
+ return 0;
+}
--
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