Files
mpd/src/util/Exception.cxx
Max Kellermann 7b938b4d14 util/Exception: sanitize message strings
This should prevent leaking unsanitized strings from libraries.
2024-06-25 20:29:07 +02:00

87 lines
2.0 KiB
C++

// SPDX-License-Identifier: BSD-2-Clause
// author: Max Kellermann <max.kellermann@gmail.com>
#include "Exception.hxx"
#include "CharUtil.hxx"
#include "StringStrip.hxx"
#include <utility>
/**
* Append the given C string to a std::string, with some
* sanitizations: strip whitespace at the beginning and the end and
* combine multiple whitespace to a single space.
*
* This shall compress strangely formatted multi-line messages (which
* may come from third-party libraries) to a single line.
*/
static void
AppendSanitize(std::string &dest, const char *src) noexcept
{
src = StripLeft(src);
bool space = false;
while (char ch = *src++) {
if (IsWhitespaceFast(ch)) {
space = true;
continue;
}
if (space) {
space = false;
dest.push_back(' ');
}
dest.push_back(ch);
}
}
template<typename T>
static void
AppendNestedMessage(std::string &result, T &&e,
const char *fallback, const char *separator) noexcept
{
try {
std::rethrow_if_nested(std::forward<T>(e));
} catch (const std::exception &nested) {
result += separator;
AppendSanitize(result, nested.what());
AppendNestedMessage(result, nested, fallback, separator);
} catch (const std::nested_exception &ne) {
AppendNestedMessage(result, ne, fallback, separator);
} catch (const char *s) {
result += separator;
AppendSanitize(result, s);
} catch (...) {
result += separator;
result += fallback;
}
}
std::string
GetFullMessage(const std::exception &e,
const char *fallback, const char *separator) noexcept
{
std::string result;
AppendSanitize(result, e.what());
AppendNestedMessage(result, e, fallback, separator);
return result;
}
std::string
GetFullMessage(std::exception_ptr ep,
const char *fallback, const char *separator) noexcept
{
try {
std::rethrow_exception(std::move(ep));
} catch (const std::exception &e) {
return GetFullMessage(e, fallback, separator);
} catch (const std::nested_exception &ne) {
return GetFullMessage(ne.nested_ptr(), fallback, separator);
} catch (const char *s) {
return s;
} catch (...) {
return fallback;
}
}