From 1c92751a73f873e3e2af2973948a7dd03f6a9224 Mon Sep 17 00:00:00 2001
From: jD91mZM2 <me@krake.one>
Date: Sat, 17 Nov 2018 20:26:43 +0100
Subject: [PATCH] Don't rely on integer wrapping in ctype
Don't rely on integer wrapping in ctype and fix strcasecmp on
non-alphabetic characters
---
src/header/ctype/mod.rs | 18 +++++++++---------
src/header/strings/mod.rs | 3 ++-
tests/strings.c | 3 +++
3 files changed, 14 insertions(+), 10 deletions(-)
diff --git a/src/header/ctype/mod.rs b/src/header/ctype/mod.rs
index 8506f8425..59e5c0ce6 100644
--- a/src/header/ctype/mod.rs
+++ b/src/header/ctype/mod.rs
@@ -24,27 +24,27 @@ pub extern "C" fn isblank(c: c_int) -> c_int {
#[no_mangle]
pub extern "C" fn iscntrl(c: c_int) -> c_int {
- ((c as c_uint) < 0x20 || c == 0x7f) as c_int
+ (c < 0x20 || c == 0x7f) as c_int
}
#[no_mangle]
pub extern "C" fn isdigit(c: c_int) -> c_int {
- (((c - 0x30) as c_uint) < 10) as c_int
+ (c >= b'0' as c_int && c <= b'9' as c_int) as c_int
}
#[no_mangle]
pub extern "C" fn isgraph(c: c_int) -> c_int {
- (((c - 0x21) as c_uint) < 0x5e) as c_int
+ (c >= 0x21 && c < 0x7e) as c_int
}
#[no_mangle]
pub extern "C" fn islower(c: c_int) -> c_int {
- (((c - 0x61) as c_uint) < 26) as c_int
+ (c >= b'a' as c_int && c <= b'z' as c_int) as c_int
}
#[no_mangle]
pub extern "C" fn isprint(c: c_int) -> c_int {
- (((c - 0x20) as c_uint) < 0x5f) as c_int
+ (c >= 0x20 && c < 0x7f) as c_int
}
#[no_mangle]
@@ -59,12 +59,12 @@ pub extern "C" fn isspace(c: c_int) -> c_int {
#[no_mangle]
pub extern "C" fn isupper(c: c_int) -> c_int {
- (((c - 0x41) as c_uint) < 26) as c_int
+ (c >= b'A' as c_int && c <= b'Z' as c_int) as c_int
}
#[no_mangle]
pub extern "C" fn isxdigit(c: c_int) -> c_int {
- (isdigit(c) != 0 || ((c as c_int) | 32) - ('a' as c_int) < 6) as c_int
+ (isdigit(c) != 0 || (c | 32 >= b'a' as c_int && c | 32 <= 'f' as c_int)) as c_int
}
#[no_mangle]
@@ -77,7 +77,7 @@ pub extern "C" fn toascii(c: c_int) -> c_int {
#[no_mangle]
pub extern "C" fn tolower(c: c_int) -> c_int {
if isupper(c) != 0 {
- c + 0x20
+ c | 0x20
} else {
c
}
@@ -86,7 +86,7 @@ pub extern "C" fn tolower(c: c_int) -> c_int {
#[no_mangle]
pub extern "C" fn toupper(c: c_int) -> c_int {
if islower(c) != 0 {
- c - 0x20
+ c & !0x20
} else {
c
}
diff --git a/src/header/strings/mod.rs b/src/header/strings/mod.rs
index 562f5d805..78d2a5c44 100644
--- a/src/header/strings/mod.rs
+++ b/src/header/strings/mod.rs
@@ -2,6 +2,7 @@
use core::ptr;
+use header::ctype;
use platform::types::*;
#[no_mangle]
@@ -76,7 +77,7 @@ pub unsafe extern "C" fn strncasecmp(
mut n: size_t,
) -> c_int {
while n > 0 && (*first != 0 || *second != 0) {
- let cmp = (*first & !32) as c_int - (*second & !32) as c_int;
+ let cmp = ctype::tolower(*first as c_int) - ctype::tolower(*second as c_int);
if cmp != 0 {
return cmp;
}
diff --git a/tests/strings.c b/tests/strings.c
index ecc098a02..fefb631a6 100644
--- a/tests/strings.c
+++ b/tests/strings.c
@@ -22,6 +22,9 @@ int main() {
assert(strncasecmp("FLOOR0_1", "FLOOR0_1FLOOR4_1", 8) == 0);
assert(strncasecmp("FL00RO_1", "FLOOR0_1FLOOR4_1", 8) < 0);
+ // Ensure we aren't relying on the 5th (lowercase) bit on non-alpha characters
+ assert(strcasecmp("{[", "[{") > 0);
+
bzero(new, 1);
assert(*new == 0);
assert(*(new+1) == 'i');
--
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