qemu/pc-bios/s390-ccw/libc.c
Markus Armbruster d796588ba1 pc-bios/s390-ccw: Clean up harmless misuse of isdigit()
atoui() and get_index() pass char values to isdigit().  With a
standard isdigit(), we'd get undefined behavior when the value is
negative.  Can't happen as char is unsigned on s390x.  Even if it
ould, we're actually using isdigit() from pc-bios/s390-ccw/libc.h
here, which works fine for negative values.  Clean up anyway, just
to avoid setting a bad example.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190418145355.21100-6-armbru@redhat.com>
[thuth: updated the commit message]
Signed-off-by: Thomas Huth <thuth@redhat.com>
2019-05-08 10:52:14 +02:00

88 lines
2.1 KiB
C

/*
* libc-style definitions and functions
*
* Copyright 2018 IBM Corp.
* Author(s): Collin L. Walling <walling@linux.vnet.ibm.com>
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*/
#include "libc.h"
#include "s390-ccw.h"
/**
* atoui:
* @str: the string to be converted.
*
* Given a string @str, convert it to an integer. Leading spaces are
* ignored. Any other non-numerical value will terminate the conversion
* and return 0. This function only handles numbers between 0 and
* UINT64_MAX inclusive.
*
* Returns: an integer converted from the string @str, or the number 0
* if an error occurred.
*/
uint64_t atoui(const char *str)
{
int val = 0;
if (!str || !str[0]) {
return 0;
}
while (*str == ' ') {
str++;
}
while (*str) {
if (!isdigit(*(unsigned char *)str)) {
break;
}
val = val * 10 + *str - '0';
str++;
}
return val;
}
/**
* uitoa:
* @num: an integer (base 10) to be converted.
* @str: a pointer to a string to store the conversion.
* @len: the length of the passed string.
*
* Given an integer @num, convert it to a string. The string @str must be
* allocated beforehand. The resulting string will be null terminated and
* returned. This function only handles numbers between 0 and UINT64_MAX
* inclusive.
*
* Returns: the string @str of the converted integer @num
*/
char *uitoa(uint64_t num, char *str, size_t len)
{
long num_idx = 1; /* account for NUL */
uint64_t tmp = num;
IPL_assert(str != NULL, "uitoa: no space allocated to store string");
/* Count indices of num */
while ((tmp /= 10) != 0) {
num_idx++;
}
/* Check if we have enough space for num and NUL */
IPL_assert(len > num_idx, "uitoa: array too small for conversion");
str[num_idx--] = '\0';
/* Convert int to string */
while (num_idx >= 0) {
str[num_idx--] = num % 10 + '0';
num /= 10;
}
return str;
}