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string: fix sprintf

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Signed-off-by: Simon Rozman <simon@rozman.si>
This commit is contained in:
Simon Rozman 2024-01-05 17:01:43 +01:00
parent 0eebde6d81
commit 1685cd3283
1 changed files with 20 additions and 31 deletions
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51
include/stdex/string.hpp
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@ -2320,42 +2320,24 @@ namespace stdex
/// \cond internal
inline int vsnprintf(_Out_z_cap_(capacity) char* str, _In_ size_t capacity, _In_z_ _Printf_format_string_params_(2) const char* format, _In_opt_ locale_t locale, _In_ va_list arg)
{
int r;
#ifdef _WIN32
// Don't use _vsnprintf_s(). It terminates the string even if we want to print to the edge of the buffer.
#pragma warning(suppress: 4996)
r = _vsnprintf_l(str, capacity, format, locale, arg);
return _vsnprintf_l(str, capacity, format, locale, arg);
#else
r = ::vsnprintf(str, capacity, format, arg);
return ::vsnprintf(str, capacity, format, arg);
#endif
if (r == -1 && strnlen(str, capacity) == capacity) {
// Buffer overrun. Estimate buffer size for the next iteration.
capacity += std::max<size_t>(capacity / 8, 0x80);
if (capacity > INT_MAX)
throw std::invalid_argument("string too big");
return (int)capacity;
}
return r;
}
inline int vsnprintf(_Out_z_cap_(capacity) wchar_t* str, _In_ size_t capacity, _In_z_ _Printf_format_string_params_(2) const wchar_t* format, _In_opt_ locale_t locale, _In_ va_list arg)
{
int r;
#ifdef _WIN32
// Don't use _vsnwprintf_s(). It terminates the string even if we want to print to the edge of the buffer.
#pragma warning(suppress: 4996)
r = _vsnwprintf_l(str, capacity, format, locale, arg);
return _vsnwprintf_l(str, capacity, format, locale, arg);
#else
r = vswprintf(str, capacity, format, arg);
return vswprintf(str, capacity, format, arg);
#endif
if (r == -1 && strnlen(str, capacity) == capacity) {
// Buffer overrun. Estimate buffer size for the next iteration.
capacity += std::max<size_t>(capacity / 8, 0x80);
if (capacity > INT_MAX)
throw std::invalid_argument("string too big");
return (int)capacity;
}
return r;
}
/// \endcond
@ -2375,22 +2357,29 @@ namespace stdex
T buf[1024 / sizeof(T)];
// Try with stack buffer first.
int count = vsnprintf(buf, _countof(buf) - 1, format, locale, arg);
if (count >= 0) {
int count = vsnprintf(buf, _countof(buf), format, locale, arg);
if (0 <= count && count < _countof(buf)) {
// Copy from stack.
str.append(buf, count);
return count;
}
for (size_t capacity = 2 * 1024 / sizeof(T);; capacity *= 2) {
// Allocate on heap and retry.
auto buf_dyn = std::make_unique<T[]>(capacity);
count = vsnprintf(buf_dyn.get(), capacity - 1, format, locale, arg);
if (count >= 0) {
if (count < 0) {
switch (errno) {
case 0:
count = vsnprintf(NULL, 0, format, locale, arg);
break;
case EINVAL: throw std::invalid_argument("invalid vsnprintf arguments");
case EILSEQ: throw std::runtime_error("encoding error");
default: throw std::runtime_error("failed to format string");
}
}
auto buf_dyn = std::make_unique<T[]>(count + 1);
count = vsnprintf(buf_dyn.get(), count + 1, format, locale, arg);
if (count < 0) _Unlikely_
throw std::runtime_error("failed to format string");
str.append(buf_dyn.get(), count);
return count;
}
}
}
///
/// Formats string using `printf()`.