MINGW-packages: Exception handling is broken on mingw32 when using static runtime libraries.

If you build ccache >= 4.2 for mingw32, it crashes at runtime. This bug started to occur when static linking was enabled for the gcc runtime libraries. (https://github.com/ccache/ccache/pull/732)

The error almost always occurs in the same place: In Util.cpp read_file rais an exception:

std::string
read_file(const std::string& path, size_t size_hint)
{
  if (size_hint == 0) {
    auto stat = Stat::stat(path);
    if (!stat) {
>>    throw Error(strerror(errno));
    }
    size_hint = stat.size();
  }

But the catch block in the calling function is never reached.

std::string data;
  try {
>>  data = Util::read_file(path);
  } catch (const Error&) {
    // Ignore.
    return counters;
  }

Here is the callstack of “ccache -s” :

msvcrt.dll!msvcrt!_exit (Unbekannte Quelle:0)
msvcrt.dll!msvcrt!abort (Unbekannte Quelle:0)
uw_init_context_1(struct _Unwind_Context * context, void * outer_cfa, void * outer_ra) (c:\_\M\mingw-w64-gcc\src\gcc-10.3.0\libgcc\unwind-dw2.c:1593)
_Unwind_RaiseException(struct _Unwind_Exception * exc) (c:\_\M\mingw-w64-gcc\src\gcc-10.3.0\libgcc\unwind.inc:93)
__cxxabiv1::__cxa_throw(void * obj, std::type_info * tinfo, void (*)(void *) dest) (c:\_\M\mingw-w64-gcc\src\gcc-10.3.0\libstdc++-v3\libsupc++\eh_throw.cc:90)
Util::read_file(const std::string & path, size_t size_hint) (...\cache-4.3\src\Util.cpp:1164)
Statistics::read(const std::string & path) (...\cache-4.3\src\Statistics.cpp:196)
operator()(const struct {...} * const __closure, const std::string & path) (...\cache-4.3\src\Statistics.cpp:102)
std::__invoke_impl<void, collect_counters(const Config&)::<lambda(const string&)>&, const std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&>(std::__invoke_other, struct {...} &)(struct {...} & __f) (c:\msys64\mingw32\include\c++\10.3.0\bits\invoke.h:60)
std::__invoke_r<void, collect_counters(const Config&)::<lambda(const string&)>&, const std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&>(struct {...} &)(struct {...} & __fn) (c:\msys64\mingw32\include\c++\10.3.0\bits\invoke.h:153)
std::_Function_handler<void(const std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&), collect_counters(const Config&)::<lambda(const string&)> >::_M_invoke(const std::_Any_data &, const std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > &)(const std::_Any_data & __functor,  __args#0) (c:\msys64\mingw32\include\c++\10.3.0\bits\std_function.h:291)
std::function<void (std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)>::operator()(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) const(const std::function<void(const std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&)> * const this,  __args#0) (c:\msys64\mingw32\include\c++\10.3.0\bits\std_function.h:622)
for_each_level_1_and_2_stats_file(const std::string &, std::function<void(const std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&)>)(const std::string & cache_dir, const std::function<void(const std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&)> function) (...\cache-4.3\src\Statistics.cpp:84)
collect_counters(const Config & config) (...\cache-4.3\src\Statistics.cpp:99)
Statistics::format_human_readable[abi:cxx11](Config const&)(const Config & config) (...\cache-4.3\src\Statistics.cpp:281)
handle_main_options(int argc, const char * const * argv) (...\cache-4.3\src\ccache.cpp:2772)
ccache_main(int argc, const char * const * argv) (...\cache-4.3\src\ccache.cpp:2839)
main(int argc, char * const * argv) (...\cache-4.3\src\main.cpp:24)

I can’t generate a minimal example for this bug. But, since the prebuilt 32 bit versions of ccache do not have this bug I assume that it is caused by the mingw32 environment and not by ccache.