Wierd names in import table

Question

I'm trying to do a static analysis of a PE file to see what it does. While doing so, I stumbled upon some really wierd function names in my objdump

DLL Name: msvcrt.dll
vma:  Hint/Ord Member-Name Bound-To
c2c68    1371  wcsncmp
c2c72    1017  _wcsnicmp
c2c7e    1229  iswdigit
c2c8a    1013  _wcslwr_s
c2c96    1225  iswalpha
c2ca2       5  ??0bad_cast@@QAE@ABV0@@Z
c2cbe      14  ??1bad_cast@@UAE@XZ
c2cd4    1241  localeconv
c2ce2    1256  memchr
c2cec    1304  strcspn
c2cf6    1292  sprintf_s
c2d02     884  _strtoi64

notice the 2 bad_cast functions. Why are they wierd looking like that? What does this syntax mean?

Answer 1

As @guntram-blohm says, these are mangled C++ functions. If you demangle the names (using, for example, an online demangler) you will get the fully decorated function names:

public: __thiscall bad_cast::bad_cast(class bad_cast const &)
public: virtual __thiscall bad_cast::~bad_cast(void)

So these functions are the constructor and the destructor for bad_cast objects, used to thrown an exception when a dynamic_cast to a reference type fails the run-time check.