//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include <cstdarg> // va_start, va_end
#include <cstddef> // size_t
#include <cstdio> // vsprintf, vsnprintf
#include <cstdlib> // malloc
#include <cstring> // strcpy, wcsncpy
#include <cwchar> // mbstate_t
// Like sprintf, but when return value >= 0 it returns
// a pointer to a malloc'd string in *sptr.
// If return >= 0, use free to delete *sptr.
int __libcpp_vasprintf(char** sptr, const char* __restrict format, va_list ap) {
*sptr = nullptr;
// Query the count required.
va_list ap_copy;
va_copy(ap_copy, ap);
_LIBCPP_DIAGNOSTIC_PUSH
_LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wformat-nonliteral")
int count = vsnprintf(nullptr, 0, format, ap_copy);
_LIBCPP_DIAGNOSTIC_POP
va_end(ap_copy);
if (count < 0)
return count;
size_t buffer_size = static_cast<size_t>(count) + 1;
char* p = static_cast<char*>(malloc(buffer_size));
if (!p)
return -1;
// If we haven't used exactly what was required, something is wrong.
// Maybe bug in vsnprintf. Report the error and return.
_LIBCPP_DIAGNOSTIC_PUSH
_LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wformat-nonliteral")
if (vsnprintf(p, buffer_size, format, ap) != count) {
_LIBCPP_DIAGNOSTIC_POP
free(p);
return -1;
}
// All good. This is returning memory to the caller not freeing it.
*sptr = p;
return count;
}
// Returns >= 0: the number of wide characters found in the
// multi byte sequence src (of src_size_bytes), that fit in the buffer dst
// (of max_dest_chars elements size). The count returned excludes the
// null terminator. When dst is NULL, no characters are copied
// and no "out" parameters are updated.
// Returns (size_t) -1: an incomplete sequence encountered.
// Leaves *src pointing the next character to convert or NULL
// if a null character was converted from *src.
size_t mbsnrtowcs(wchar_t* __restrict dst,
const char** __restrict src,
size_t src_size_bytes,
size_t max_dest_chars,
mbstate_t* __restrict ps) {
const size_t terminated_sequence = static_cast<size_t>(0);
// const size_t invalid_sequence = static_cast<size_t>(-1);
const size_t incomplete_sequence = static_cast< size_t>(-2);
size_t dest_converted = 0;
size_t source_converted = 0;
size_t source_remaining = src_size_bytes;
size_t result = 0;
bool have_result = false;
// If dst is null then max_dest_chars should be ignored according to the
// standard. Setting max_dest_chars to a large value has this effect.
if (!dst)
max_dest_chars = static_cast<size_t>(-1);
while (source_remaining) {
if (dst && dest_converted >= max_dest_chars)
break;
// Converts one multi byte character.
// if result > 0, it's the size in bytes of that character.
// othewise if result is zero it indicates the null character has been found.
// otherwise it's an error and errno may be set.
size_t char_size = mbrtowc(dst ? dst + dest_converted : nullptr, *src + source_converted, source_remaining, ps);
// Don't do anything to change errno from here on.
if (char_size > 0) {
source_remaining -= char_size;
source_converted += char_size;
++dest_converted;
continue;
}
result = char_size;
have_result = true;
break;
}
if (dst) {
if (have_result && result == terminated_sequence)
*src = nullptr;
else
*src += source_converted;
}
if (have_result && result != terminated_sequence && result != incomplete_sequence)
return static_cast<size_t>(-1);
return dest_converted;
}
// Converts max_source_chars from the wide character buffer pointer to by *src,
// into the multi byte character sequence buffer stored at dst which must be
// dst_size_bytes bytes in size.
// Returns >= 0: the number of bytes in the sequence
// converted from *src, excluding the null terminator.
// Returns size_t(-1) if an error occurs, also sets errno.
// If dst is NULL dst_size_bytes is ignored and no bytes are copied to dst
// and no "out" parameters are updated.
size_t wcsnrtombs(char* __restrict dst,
const wchar_t** __restrict src,
size_t max_source_chars,
size_t dst_size_bytes,
mbstate_t* __restrict ps) {
// const size_t invalid_sequence = static_cast<size_t>(-1);
size_t source_converted = 0;
size_t dest_converted = 0;
size_t dest_remaining = dst_size_bytes;
size_t char_size = 0;
const errno_t no_error = (errno_t)0;
errno_t result = (errno_t)0;
bool have_result = false;
bool terminator_found = false;
// If dst is null then dst_size_bytes should be ignored according to the
// standard. Setting dest_remaining to a large value has this effect.
if (!dst)
dest_remaining = static_cast<size_t>(-1);
while (source_converted != max_source_chars) {
if (!dest_remaining)
break;
wchar_t c = (*src)[source_converted];
if (dst)
result = wcrtomb_s(&char_size, dst + dest_converted, dest_remaining, c, ps);
else
result = wcrtomb_s(&char_size, nullptr, 0, c, ps);
// If result is zero there is no error and char_size contains the
// size of the multi-byte-sequence converted.
// Otherwise result indicates an errno type error.
if (result == no_error) {
if (c == L'\0') {
terminator_found = true;
break;
}
++source_converted;
if (dst)
dest_remaining -= char_size;
dest_converted += char_size;
continue;
}
have_result = true;
break;
}
if (dst) {
if (terminator_found)
*src = nullptr;
else
*src = *src + source_converted;
}
if (have_result && result != no_error) {
errno = result;
return static_cast<size_t>(-1);
}
return dest_converted;
}
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