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// file : butl/utility.cxx -*- C++ -*-
// copyright : Copyright (c) 2014-2017 Code Synthesis Ltd
// license : MIT; see accompanying LICENSE file
#include <butl/utility>
#ifdef _WIN32
# include <butl/win32-utility>
#endif
#include <string>
#include <ostream>
#include <system_error>
namespace butl
{
using namespace std;
#ifndef __cpp_lib_uncaught_exceptions
#ifdef __cpp_thread_local
thread_local
#else
__thread
#endif
bool exception_unwinding_dtor_ = false;
#ifdef _WIN32
bool&
exception_unwinding_dtor () {return exception_unwinding_dtor_;}
#endif
#endif
[[noreturn]] void
throw_generic_error (int errno_code, const char* what)
{
if (what == nullptr)
throw system_error (errno_code, generic_category ());
else
throw system_error (errno_code, generic_category (), what);
}
[[noreturn]] void
#ifndef _WIN32
throw_system_error (int system_code, int)
{
throw system_error (system_code, system_category ());
#else
throw_system_error (int system_code, int fallback_errno_code)
{
// Here we work around MinGW libstdc++ that interprets Windows system error
// codes (for example those returned by GetLastError()) as errno codes. The
// resulting system_error description will have the following form:
//
// <system_code description>: <fallback_errno_code description>
//
// Also note that the fallback-related description suffix is stripped by
// our custom operator<<(ostream, exception) for the common case (see
// below).
//
throw system_error (fallback_errno_code,
system_category (),
win32::error_msg (system_code));
#endif
}
}
namespace std
{
using namespace butl;
ostream&
operator<< (ostream& o, const exception& e)
{
const char* d (e.what ());
const char* s (d);
// Strip the leading junk (colons and spaces).
//
// Note that error descriptions for ios_base::failure exceptions thrown by
// fdstream can have the ': ' prefix for libstdc++ (read more in comment
// for throw_ios_failure()).
//
for (; *s == ' ' || *s == ':'; ++s) ;
// Strip the trailing junk (periods, spaces, newlines).
//
// Note that msvcrt adds some junk like this:
//
// Invalid data.\r\n
//
size_t n (string::traits_type::length (s));
for (; n > 0; --n)
{
switch (s[n-1])
{
case '\r':
case '\n':
case '.':
case ' ': continue;
}
break;
}
// Strip the suffix for system_error thrown by
// throw_system_error(system_code) on Windows. For example for the
// ERROR_INVALID_DATA error code the original description will be
// 'Invalid data. : Success' for MinGW libstdc++ and
// 'Invalid data. : Success.' for msvcrt.
//
if (n >= 11 &&
string::traits_type::compare (s + n - 11, ". : Success", 11) == 0)
n -= 11;
// Lower-case the first letter if the beginning looks like a word (the
// second character is the lower-case letter or space).
//
char c;
bool lc (n > 0 && alpha (c = s[0]) && c == ucase (c) &&
(n == 1 || (alpha (c = s[1]) && c == lcase (c)) || c == ' '));
// Print the description as is if no adjustment is required.
//
if (!lc && s == d && s[n] == '\0')
o << d;
else
{
// We need to produce the resulting description and then write it
// with a single formatted output operation.
//
string r (s, n);
if (lc)
r[0] = lcase (r[0]);
o << r;
}
return o;
}
}
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