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ladybird/Libraries/LibC/stdlib.cpp
Sergey Bugaev 839ae82d66 LibC: Ensure abort() doesn't return 
It's not enough to send ourselves a SIGABRT, as it may be ignored or handled
differently. We really, really want abort() to never return, as that will mess
up the assumptions of the calling code big time. So, if raise(SIGABRT) returns,
kill ourselves with SIGKILL, and if that somehow returns too, call _exit().

An alternative approach, which glibc apparently follows, is to reset SIGABRT
disposition to its default value and then send SIGABRT to yourself a second
time. That would also work, but I believe SIGKILL + _exit() to be a simpler
approach that is less likely to break in extremely weird situations.

Note that this only guarantees that abort() never returns, not that the process
actually gets killed. It's still possible to install a SIGABRT handler that
simply never returns (such as by longjmp'ing out, endlessly looping, or exec'ing
another image). That is a legitimate use case we want to support; at the same
time most software doesn't use that functionality and would benefit from hard
guarantees that abort() terminates the program. The following commit is going to
introduce means for ensuring SIGABRT handler is never reset to something
unexpected.
2020-05-26 14:35:10 +02:00

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/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <AK/Assertions.h>
#include <AK/HashMap.h>
#include <AK/Noncopyable.h>
#include <AK/StdLibExtras.h>
#include <AK/Types.h>
#include <AK/Utf8View.h>
#include <Kernel/Syscall.h>
#include <alloca.h>
#include <assert.h>
#include <ctype.h>
#include <errno.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <unistd.h>
static void strtons(const char* str, char** endptr)
{
assert(endptr);
char* ptr = const_cast<char*>(str);
while (isspace(*ptr)) {
ptr += 1;
}
*endptr = ptr;
}
enum Sign {
Negative,
Positive,
};
static Sign strtosign(const char* str, char** endptr)
{
assert(endptr);
if (*str == '+') {
*endptr = const_cast<char*>(str + 1);
return Sign::Positive;
} else if (*str == '-') {
*endptr = const_cast<char*>(str + 1);
return Sign::Negative;
} else {
*endptr = const_cast<char*>(str);
return Sign::Positive;
}
}
enum DigitConsumeDecision {
Consumed,
PosOverflow,
NegOverflow,
Invalid,
};
template<typename T, T min_value, T max_value>
class NumParser {
AK_MAKE_NONMOVABLE(NumParser)
public:
NumParser(Sign sign, int base)
: m_base(base)
, m_num(0)
, m_sign(sign)
{
m_cutoff = positive() ? (max_value / base) : (min_value / base);
m_max_digit_after_cutoff = positive() ? (max_value % base) : (min_value % base);
}
int parse_digit(char ch)
{
int digit;
if (isdigit(ch))
digit = ch - '0';
else if (islower(ch))
digit = ch - ('a' - 10);
else if (isupper(ch))
digit = ch - ('A' - 10);
else
return -1;
if (static_cast<T>(digit) >= m_base)
return -1;
return digit;
}
DigitConsumeDecision consume(char ch)
{
int digit = parse_digit(ch);
if (digit == -1)
return DigitConsumeDecision::Invalid;
if (!can_append_digit(digit)) {
if (m_sign != Sign::Negative) {
return DigitConsumeDecision::PosOverflow;
} else {
return DigitConsumeDecision::NegOverflow;
}
}
m_num *= m_base;
m_num += positive() ? digit : -digit;
return DigitConsumeDecision::Consumed;
}
T number() const { return m_num; };
private:
bool can_append_digit(int digit)
{
const bool is_below_cutoff = positive() ? (m_num < m_cutoff) : (m_num > m_cutoff);
if (is_below_cutoff) {
return true;
} else {
return m_num == m_cutoff && digit < m_max_digit_after_cutoff;
}
}
bool positive() const
{
return m_sign != Sign::Negative;
}
const T m_base;
T m_num;
T m_cutoff;
int m_max_digit_after_cutoff;
Sign m_sign;
};
typedef NumParser<int, INT_MIN, INT_MAX> IntParser;
typedef NumParser<long long, LONG_LONG_MIN, LONG_LONG_MAX> LongLongParser;
typedef NumParser<unsigned long long, 0ULL, ULONG_LONG_MAX> ULongLongParser;
static bool is_either(char* str, int offset, char lower, char upper)
{
char ch = *(str + offset);
return ch == lower || ch == upper;
}
__attribute__((warn_unused_result)) int __generate_unique_filename(char* pattern)
{
size_t length = strlen(pattern);
if (length < 6 || memcmp(pattern + length - 6, "XXXXXX", 6)) {
errno = EINVAL;
return -1;
}
size_t start = length - 6;
static constexpr char random_characters[] = "abcdefghijklmnopqrstuvwxyz0123456789";
for (int attempt = 0; attempt < 100; ++attempt) {
for (int i = 0; i < 6; ++i)
pattern[start + i] = random_characters[(rand() % sizeof(random_characters))];
struct stat st;
int rc = lstat(pattern, &st);
if (rc < 0 && errno == ENOENT)
return 0;
}
errno = EEXIST;
return -1;
}
extern "C" {
// Itanium C++ ABI methods defined in crt0.cpp
extern int __cxa_atexit(void (*function)(void*), void* paramter, void* dso_handle);
extern void __cxa_finalize(void* dso_handle);
void exit(int status)
{
__cxa_finalize(nullptr);
extern void _fini();
_fini();
fflush(stdout);
fflush(stderr);
_exit(status);
}
static void __atexit_to_cxa_atexit(void* handler)
{
reinterpret_cast<void (*)()>(handler)();
}
int atexit(void (*handler)())
{
return __cxa_atexit(__atexit_to_cxa_atexit, (void*)handler, nullptr);
}
void abort()
{
// For starters, send ourselves a SIGABRT.
raise(SIGABRT);
// If that didn't kill us, try harder.
raise(SIGKILL);
_exit(127);
}
static HashTable<const char*> s_malloced_environment_variables;
static void free_environment_variable_if_needed(const char* var)
{
if (!s_malloced_environment_variables.contains(var))
return;
free(const_cast<char*>(var));
s_malloced_environment_variables.remove(var);
}
char* getenv(const char* name)
{
size_t vl = strlen(name);
for (size_t i = 0; environ[i]; ++i) {
const char* decl = environ[i];
char* eq = strchr(decl, '=');
if (!eq)
continue;
size_t varLength = eq - decl;
if (vl != varLength)
continue;
if (strncmp(decl, name, varLength) == 0) {
return eq + 1;
}
}
return nullptr;
}
int unsetenv(const char* name)
{
auto new_var_len = strlen(name);
size_t environ_size = 0;
int skip = -1;
for (; environ[environ_size]; ++environ_size) {
char* old_var = environ[environ_size];
char* old_eq = strchr(old_var, '=');
ASSERT(old_eq);
size_t old_var_len = old_eq - old_var;
if (new_var_len != old_var_len)
continue; // can't match
if (strncmp(name, old_var, new_var_len) == 0)
skip = environ_size;
}
if (skip == -1)
return 0; // not found: no failure.
// Shuffle the existing array down by one.
memmove(&environ[skip], &environ[skip + 1], ((environ_size - 1) - skip) * sizeof(environ[0]));
environ[environ_size - 1] = nullptr;
free_environment_variable_if_needed(name);
return 0;
}
int setenv(const char* name, const char* value, int overwrite)
{
if (!overwrite && !getenv(name))
return 0;
auto length = strlen(name) + strlen(value) + 2;
auto* var = (char*)malloc(length);
snprintf(var, length, "%s=%s", name, value);
s_malloced_environment_variables.set(var);
return putenv(var);
}
int putenv(char* new_var)
{
char* new_eq = strchr(new_var, '=');
if (!new_eq)
return unsetenv(new_var);
auto new_var_len = new_eq - new_var;
int environ_size = 0;
for (; environ[environ_size]; ++environ_size) {
char* old_var = environ[environ_size];
char* old_eq = strchr(old_var, '=');
ASSERT(old_eq);
auto old_var_len = old_eq - old_var;
if (new_var_len != old_var_len)
continue; // can't match
if (strncmp(new_var, old_var, new_var_len) == 0) {
free_environment_variable_if_needed(old_var);
environ[environ_size] = new_var;
return 0;
}
}
// At this point, we need to append the new var.
// 2 here: one for the new var, one for the sentinel value.
char** new_environ = (char**)malloc((environ_size + 2) * sizeof(char*));
if (new_environ == nullptr) {
errno = ENOMEM;
return -1;
}
for (int i = 0; environ[i]; ++i) {
new_environ[i] = environ[i];
}
new_environ[environ_size] = new_var;
new_environ[environ_size + 1] = nullptr;
// swap new and old
// note that the initial environ is not heap allocated!
extern bool __environ_is_malloced;
if (__environ_is_malloced)
free(environ);
__environ_is_malloced = true;
environ = new_environ;
return 0;
}
double strtod(const char* str, char** endptr)
{
// Parse spaces, sign, and base
char* parse_ptr = const_cast<char*>(str);
strtons(parse_ptr, &parse_ptr);
const Sign sign = strtosign(parse_ptr, &parse_ptr);
// Parse inf/nan, if applicable.
if (is_either(parse_ptr, 0, 'i', 'I')) {
if (is_either(parse_ptr, 1, 'n', 'N')) {
if (is_either(parse_ptr, 2, 'f', 'F')) {
parse_ptr += 3;
if (is_either(parse_ptr, 0, 'i', 'I')) {
if (is_either(parse_ptr, 1, 'n', 'N')) {
if (is_either(parse_ptr, 2, 'i', 'I')) {
if (is_either(parse_ptr, 3, 't', 'T')) {
if (is_either(parse_ptr, 4, 'y', 'Y')) {
parse_ptr += 5;
}
}
}
}
}
if (endptr)
*endptr = parse_ptr;
// Don't set errno to ERANGE here:
// The caller may want to distinguish between "input is
// literal infinity" and "input is not literal infinity
// but did not fit into double".
if (sign != Sign::Negative) {
return __builtin_huge_val();
} else {
return -__builtin_huge_val();
}
}
}
}
if (is_either(parse_ptr, 0, 'n', 'N')) {
if (is_either(parse_ptr, 1, 'a', 'A')) {
if (is_either(parse_ptr, 2, 'n', 'N')) {
if (endptr)
*endptr = parse_ptr + 3;
errno = ERANGE;
if (sign != Sign::Negative) {
return __builtin_nan("");
} else {
return -__builtin_nan("");
}
}
}
}
// Parse base
char exponent_lower;
char exponent_upper;
int base = 10;
if (*parse_ptr == '0') {
const char base_ch = *(parse_ptr + 1);
if (base_ch == 'x' || base_ch == 'X') {
base = 16;
parse_ptr += 2;
}
}
if (base == 10) {
exponent_lower = 'e';
exponent_upper = 'E';
} else {
exponent_lower = 'p';
exponent_upper = 'P';
}
// Parse "digits", possibly keeping track of the exponent offset.
// We parse the most significant digits and the position in the
// base-`base` representation separately. This allows us to handle
// numbers like `0.0000000000000000000000000000000000001234` or
// `1234567890123456789012345678901234567890` with ease.
LongLongParser digits { sign, base };
bool digits_usable = false;
bool should_continue = true;
bool digits_overflow = false;
bool after_decimal = false;
int exponent = 0;
do {
if (!after_decimal && *parse_ptr == '.') {
after_decimal = true;
parse_ptr += 1;
continue;
}
bool is_a_digit;
if (digits_overflow) {
is_a_digit = digits.parse_digit(*parse_ptr) != -1;
} else {
DigitConsumeDecision decision = digits.consume(*parse_ptr);
switch (decision) {
case DigitConsumeDecision::Consumed:
is_a_digit = true;
// The very first actual digit must pass here:
digits_usable = true;
break;
case DigitConsumeDecision::PosOverflow:
// fallthrough
case DigitConsumeDecision::NegOverflow:
is_a_digit = true;
digits_overflow = true;
break;
case DigitConsumeDecision::Invalid:
is_a_digit = false;
break;
default:
ASSERT_NOT_REACHED();
}
}
if (is_a_digit) {
exponent -= after_decimal ? 1 : 0;
exponent += digits_overflow ? 1 : 0;
}
should_continue = is_a_digit;
parse_ptr += should_continue;
} while (should_continue);
if (!digits_usable) {
// No actual number value available.
if (endptr)
*endptr = const_cast<char*>(str);
return 0.0;
}
// Parse exponent.
// We already know the next character is not a digit in the current base,
// nor a valid decimal point. Check whether it's an exponent sign.
if (*parse_ptr == exponent_lower || *parse_ptr == exponent_upper) {
// Need to keep the old parse_ptr around, in case of rollback.
char* old_parse_ptr = parse_ptr;
parse_ptr += 1;
// Can't use atol or strtol here: Must accept excessive exponents,
// even exponents >64 bits.
Sign exponent_sign = strtosign(parse_ptr, &parse_ptr);
IntParser exponent_parser { exponent_sign, base };
bool exponent_usable = false;
bool exponent_overflow = false;
should_continue = true;
do {
bool is_a_digit;
if (exponent_overflow) {
is_a_digit = exponent_parser.parse_digit(*parse_ptr) != -1;
} else {
DigitConsumeDecision decision = exponent_parser.consume(*parse_ptr);
switch (decision) {
case DigitConsumeDecision::Consumed:
is_a_digit = true;
// The very first actual digit must pass here:
exponent_usable = true;
break;
case DigitConsumeDecision::PosOverflow:
// fallthrough
case DigitConsumeDecision::NegOverflow:
is_a_digit = true;
exponent_overflow = true;
break;
case DigitConsumeDecision::Invalid:
is_a_digit = false;
break;
default:
ASSERT_NOT_REACHED();
}
}
should_continue = is_a_digit;
parse_ptr += should_continue;
} while (should_continue);
if (!exponent_usable) {
parse_ptr = old_parse_ptr;
} else if (exponent_overflow) {
// Technically this is wrong. If someone gives us 5GB of digits,
// and then an exponent of -5_000_000_000, the resulting exponent
// should be around 0.
// However, I think it's safe to assume that we never have to deal
// with that many digits anyway.
if (sign != Sign::Negative) {
exponent = INT_MIN;
} else {
exponent = INT_MAX;
}
} else {
// Literal exponent is usable and fits in an int.
// However, `exponent + exponent_parser.number()` might overflow an int.
// This would result in the wrong sign of the exponent!
long long new_exponent = static_cast<long long>(exponent) + static_cast<long long>(exponent_parser.number());
if (new_exponent < INT_MIN) {
exponent = INT_MIN;
} else if (new_exponent > INT_MAX) {
exponent = INT_MAX;
} else {
exponent = static_cast<int>(new_exponent);
}
}
}
// Parsing finished. now we only have to compute the result.
if (endptr)
*endptr = const_cast<char*>(parse_ptr);
// If `digits` is zero, we don't even have to look at `exponent`.
if (digits.number() == 0) {
if (sign != Sign::Negative) {
return 0.0;
} else {
return -0.0;
}
}
// Deal with extreme exponents.
// The smallest normal is 2^-1022.
// The smallest denormal is 2^-1074.
// The largest number in `digits` is 2^63 - 1.
// Therefore, if "base^exponent" is smaller than 2^-(1074+63), the result is 0.0 anyway.
// This threshold is roughly 5.3566 * 10^-343.
// So if the resulting exponent is -344 or lower (closer to -inf),
// the result is 0.0 anyway.
// We only need to avoid false positives, so we can ignore base 16.
if (exponent <= -344) {
errno = ERANGE;
// Definitely can't be represented more precisely.
// I lied, sometimes the result is +0.0, and sometimes -0.0.
if (sign != Sign::Negative) {
return 0.0;
} else {
return -0.0;
}
}
// The largest normal is 2^+1024-eps.
// The smallest number in `digits` is 1.
// Therefore, if "base^exponent" is 2^+1024, the result is INF anyway.
// This threshold is roughly 1.7977 * 10^-308.
// So if the resulting exponent is +309 or higher,
// the result is INF anyway.
// We only need to avoid false positives, so we can ignore base 16.
if (exponent >= 309) {
errno = ERANGE;
// Definitely can't be represented more precisely.
// I lied, sometimes the result is +INF, and sometimes -INF.
if (sign != Sign::Negative) {
return __builtin_huge_val();
} else {
return -__builtin_huge_val();
}
}
// TODO: If `exponent` is large, this could be made faster.
double value = digits.number();
if (exponent < 0) {
exponent = -exponent;
for (int i = 0; i < exponent; ++i) {
value /= base;
}
if (value == -0.0 || value == +0.0) {
errno = ERANGE;
}
} else if (exponent > 0) {
for (int i = 0; i < exponent; ++i) {
value *= base;
}
if (value == -__builtin_huge_val() || value == +__builtin_huge_val()) {
errno = ERANGE;
}
}
return value;
}
long double strtold(const char* str, char** endptr)
{
assert(sizeof(double) == sizeof(long double));
return strtod(str, endptr);
}
float strtof(const char* str, char** endptr)
{
return strtod(str, endptr);
}
double atof(const char* str)
{
return strtod(str, nullptr);
}
int atoi(const char* str)
{
long value = strtol(str, nullptr, 10);
if (value > INT_MAX) {
return INT_MAX;
}
return value;
}
long atol(const char* str)
{
return strtol(str, nullptr, 10);
}
long long atoll(const char* str)
{
return strtoll(str, nullptr, 10);
}
static char ptsname_buf[32];
char* ptsname(int fd)
{
if (ptsname_r(fd, ptsname_buf, sizeof(ptsname_buf)) < 0)
return nullptr;
return ptsname_buf;
}
int ptsname_r(int fd, char* buffer, size_t size)
{
int rc = syscall(SC_ptsname_r, fd, buffer, size);
__RETURN_WITH_ERRNO(rc, rc, -1);
}
static unsigned long s_next_rand = 1;
int rand()
{
s_next_rand = s_next_rand * 1103515245 + 12345;
return ((unsigned)(s_next_rand / ((RAND_MAX + 1) * 2)) % (RAND_MAX + 1));
}
void srand(unsigned seed)
{
s_next_rand = seed;
}
int abs(int i)
{
return i < 0 ? -i : i;
}
long int random()
{
return rand();
}
void srandom(unsigned seed)
{
srand(seed);
}
int system(const char* command)
{
if (!command)
return 1;
auto child = fork();
if (child < 0)
return -1;
if (!child) {
int rc = execl("/bin/sh", "sh", "-c", command, nullptr);
ASSERT(rc < 0);
perror("execl");
exit(127);
}
int wstatus;
waitpid(child, &wstatus, 0);
return WEXITSTATUS(wstatus);
}
char* mktemp(char* pattern)
{
if (__generate_unique_filename(pattern) < 0)
pattern[0] = '\0';
return pattern;
}
int mkstemp(char* pattern)
{
char* path = mktemp(pattern);
int fd = open(path, O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR); // I'm using the flags I saw glibc using.
if (fd >= 0)
return fd;
return -1;
}
char* mkdtemp(char* pattern)
{
if (__generate_unique_filename(pattern) < 0)
return nullptr;
if (mkdir(pattern, 0700) < 0)
return nullptr;
return pattern;
}
void* bsearch(const void* key, const void* base, size_t nmemb, size_t size, int (*compar)(const void*, const void*))
{
int low = 0;
int high = nmemb - 1;
while (low <= high) {
int middle = (low + high) / 2;
void* middle_memb = const_cast<char*>((const char*)base + middle * size);
int comparison = compar(key, middle_memb);
if (comparison < 0)
high = middle - 1;
else if (comparison > 0)
low = middle + 1;
else
return middle_memb;
}
return NULL;
}
div_t div(int numerator, int denominator)
{
div_t result;
result.quot = numerator / denominator;
result.rem = numerator % denominator;
if (numerator >= 0 && result.rem < 0) {
result.quot++;
result.rem -= denominator;
}
return result;
}
ldiv_t ldiv(long numerator, long denominator)
{
ldiv_t result;
result.quot = numerator / denominator;
result.rem = numerator % denominator;
if (numerator >= 0 && result.rem < 0) {
result.quot++;
result.rem -= denominator;
}
return result;
}
size_t mbstowcs(wchar_t*, const char*, size_t)
{
ASSERT_NOT_REACHED();
}
size_t mbtowc(wchar_t* wch, const char* data, size_t data_size)
{
// FIXME: This needs a real implementation.
UNUSED_PARAM(data_size);
if (wch && data) {
*wch = *data;
return 1;
}
if (!wch && data) {
return 1;
}
return 0;
}
int wctomb(char*, wchar_t)
{
ASSERT_NOT_REACHED();
}
size_t wcstombs(char* dest, const wchar_t* src, size_t max)
{
char* originalDest = dest;
while ((size_t)(dest - originalDest) < max) {
StringView v { (const char*)src, sizeof(wchar_t) };
// FIXME: dependent on locale, for now utf-8 is supported.
Utf8View utf8 { v };
if (*utf8.begin() == '\0') {
*dest = '\0';
return (size_t)(dest - originalDest); // Exclude null character in returned size
}
for (auto byte : utf8) {
if (byte != '\0')
*dest++ = byte;
}
++src;
}
return max;
}
long strtol(const char* str, char** endptr, int base)
{
long long value = strtoll(str, endptr, base);
if (value < LONG_MIN) {
errno = ERANGE;
return LONG_MIN;
} else if (value > LONG_MAX) {
errno = ERANGE;
return LONG_MAX;
}
return value;
}
unsigned long strtoul(const char* str, char** endptr, int base)
{
unsigned long long value = strtoull(str, endptr, base);
if (value > ULONG_MAX) {
errno = ERANGE;
return ULONG_MAX;
}
return value;
}
long long strtoll(const char* str, char** endptr, int base)
{
// Parse spaces and sign
char* parse_ptr = const_cast<char*>(str);
strtons(parse_ptr, &parse_ptr);
const Sign sign = strtosign(parse_ptr, &parse_ptr);
// Parse base
if (base == 0) {
if (*parse_ptr == '0') {
parse_ptr += 1;
if (*parse_ptr == 'x' || *parse_ptr == 'X') {
base = 16;
parse_ptr += 2;
} else {
base = 8;
}
} else {
base = 10;
}
}
// Parse actual digits.
LongLongParser digits { sign, base };
bool digits_usable = false;
bool should_continue = true;
bool overflow = false;
do {
bool is_a_digit;
if (overflow) {
is_a_digit = digits.parse_digit(*parse_ptr) >= 0;
} else {
DigitConsumeDecision decision = digits.consume(*parse_ptr);
switch (decision) {
case DigitConsumeDecision::Consumed:
is_a_digit = true;
// The very first actual digit must pass here:
digits_usable = true;
break;
case DigitConsumeDecision::PosOverflow: // fall-through
case DigitConsumeDecision::NegOverflow:
is_a_digit = true;
overflow = true;
break;
case DigitConsumeDecision::Invalid:
is_a_digit = false;
break;
default:
ASSERT_NOT_REACHED();
}
}
should_continue = is_a_digit;
parse_ptr += should_continue;
} while (should_continue);
if (!digits_usable) {
// No actual number value available.
if (endptr)
*endptr = const_cast<char*>(str);
return 0;
}
if (endptr)
*endptr = parse_ptr;
if (overflow) {
errno = ERANGE;
if (sign != Sign::Negative) {
return LONG_LONG_MAX;
} else {
return LONG_LONG_MIN;
}
}
return digits.number();
}
unsigned long long strtoull(const char* str, char** endptr, int base)
{
// Parse spaces and sign
char* parse_ptr = const_cast<char*>(str);
strtons(parse_ptr, &parse_ptr);
// Parse base
if (base == 0) {
if (*parse_ptr == '0') {
parse_ptr += 1;
if (*parse_ptr == 'x' || *parse_ptr == 'X') {
base = 16;
parse_ptr += 2;
} else {
base = 8;
}
} else {
base = 10;
}
}
// Parse actual digits.
ULongLongParser digits { Sign::Positive, base };
bool digits_usable = false;
bool should_continue = true;
bool overflow = false;
do {
bool is_a_digit;
if (overflow) {
is_a_digit = digits.parse_digit(*parse_ptr) >= 0;
} else {
DigitConsumeDecision decision = digits.consume(*parse_ptr);
switch (decision) {
case DigitConsumeDecision::Consumed:
is_a_digit = true;
// The very first actual digit must pass here:
digits_usable = true;
break;
case DigitConsumeDecision::PosOverflow: // fall-through
case DigitConsumeDecision::NegOverflow:
is_a_digit = true;
overflow = true;
break;
case DigitConsumeDecision::Invalid:
is_a_digit = false;
break;
default:
ASSERT_NOT_REACHED();
}
}
should_continue = is_a_digit;
parse_ptr += should_continue;
} while (should_continue);
if (!digits_usable) {
// No actual number value available.
if (endptr)
*endptr = const_cast<char*>(str);
return 0;
}
if (endptr)
*endptr = parse_ptr;
if (overflow) {
errno = ERANGE;
return LONG_LONG_MAX;
}
return digits.number();
}
// Serenity's PRNG is not cryptographically secure. Do not rely on this for
// any real crypto! These functions (for now) are for compatibility.
// TODO: In the future, rand can be made determinstic and this not.
uint32_t arc4random(void)
{
char buf[4];
syscall(SC_getrandom, buf, 4, 0);
return *(uint32_t*)buf;
}
void arc4random_buf(void* buffer, size_t buffer_size)
{
// arc4random_buf should never fail, but user supplied buffers could fail.
// However, if the user passes a garbage buffer, that's on them.
syscall(SC_getrandom, buffer, buffer_size, 0);
}
uint32_t arc4random_uniform(uint32_t max_bounds)
{
// XXX: Should actually apply special rules for uniformity; avoid what is
// called "modulo bias".
return arc4random() % max_bounds;
}
char* realpath(const char* pathname, char* buffer)
{
if (!pathname) {
errno = EFAULT;
return nullptr;
}
size_t size = PATH_MAX;
if (buffer == nullptr)
buffer = (char*)malloc(size);
Syscall::SC_realpath_params params { { pathname, strlen(pathname) }, { buffer, size } };
int rc = syscall(SC_realpath, &params);
if (rc < 0) {
errno = -rc;
return nullptr;
}
errno = 0;
return buffer;
}
int posix_openpt(int flags)
{
if (flags & ~(O_RDWR | O_NOCTTY | O_CLOEXEC)) {
errno = EINVAL;
return -1;
}
return open("/dev/ptmx", flags);
}
int grantpt(int fd)
{
(void)fd;
return 0;
}
int unlockpt(int fd)
{
(void)fd;
return 0;
}
}
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