From 9325183b211905673ac2b550c108ced32f1e7189 Mon Sep 17 00:00:00 2001
From: Jeremy Soller <jeremy@system76.com>
Date: Sat, 1 Dec 2018 08:55:02 -0700
Subject: [PATCH] Fix strcat
---
src/header/string/mod.rs | 24 +++++++++++++-----------
tests/Makefile | 1 +
tests/expected/string/strcat.stderr | 0
tests/expected/string/strcat.stdout | 2 ++
tests/string/strcat.c | 12 ++++++++++++
5 files changed, 28 insertions(+), 11 deletions(-)
create mode 100644 tests/expected/string/strcat.stderr
create mode 100644 tests/expected/string/strcat.stdout
create mode 100644 tests/string/strcat.c
diff --git a/src/header/string/mod.rs b/src/header/string/mod.rs
index 1e1d018b..48788f2b 100644
--- a/src/header/string/mod.rs
+++ b/src/header/string/mod.rs
@@ -147,11 +147,6 @@ pub unsafe extern "C" fn memset(s: *mut c_void, c: c_int, n: size_t) -> *mut c_v
s
}
-#[no_mangle]
-pub unsafe extern "C" fn strcat(s1: *mut c_char, s2: *const c_char) -> *mut c_char {
- strncat(s1, s2, usize::MAX)
-}
-
#[no_mangle]
pub unsafe extern "C" fn strchr(mut s: *const c_char, c: c_int) -> *mut c_char {
let c = c as c_char;
@@ -283,18 +278,25 @@ pub unsafe extern "C" fn strnlen(s: *const c_char, size: size_t) -> size_t {
i as size_t
}
+#[no_mangle]
+pub unsafe extern "C" fn strcat(s1: *mut c_char, s2: *const c_char) -> *mut c_char {
+ strncat(s1, s2, usize::MAX)
+}
+
#[no_mangle]
pub unsafe extern "C" fn strncat(s1: *mut c_char, s2: *const c_char, n: size_t) -> *mut c_char {
- let mut idx = strlen(s1 as *const _) as isize;
- for i in 0..n as isize {
- if *s2.offset(i) == 0 {
+ let len = strlen(s1 as *const c_char);
+ let mut i = 0;
+ while i < n {
+ let b = *s2.offset(i as isize);
+ if b == 0 {
break;
}
- *s1.offset(idx) = *s2.offset(i);
- idx += 1;
+ *s1.offset((len + i) as isize) = b;
+ i += 1;
}
- *s1.offset(idx) = 0;
+ *s1.offset((len + i) as isize) = 0;
s1
}
diff --git a/tests/Makefile b/tests/Makefile
index 609d6b4c..163a5041 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -46,6 +46,7 @@ EXPECT_BINS=\
stdlib/strtoul \
stdlib/system \
string/mem \
+ string/strcat \
string/strchr \
string/strcpy \
string/strcspn \
diff --git a/tests/expected/string/strcat.stderr b/tests/expected/string/strcat.stderr
new file mode 100644
index 00000000..e69de29b
diff --git a/tests/expected/string/strcat.stdout b/tests/expected/string/strcat.stdout
new file mode 100644
index 00000000..10bda518
--- /dev/null
+++ b/tests/expected/string/strcat.stdout
@@ -0,0 +1,2 @@
+hello world
+hello world
diff --git a/tests/string/strcat.c b/tests/string/strcat.c
new file mode 100644
index 00000000..6913c557
--- /dev/null
+++ b/tests/string/strcat.c
@@ -0,0 +1,12 @@
+#include <string.h>
+#include <stdio.h>
+
+int main(int argc, char* argv[]) {
+ char dest1[12] = "hello";
+ printf("%s\n", strcat(dest1, " world")); // should be hello world
+
+ char dest2[12] = "hello";
+ printf("%s\n", strncat(dest2, " world foobar", 6)); // should be hello world
+
+ return 0;
+}
--
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