typeinfo and exceptions

[Tim Janik]

hi all.

i really fail to see what i'm doing wrong in the following code:

struct Exception : std::exception {
  Exception (const char *format, ...) __attribute__((__format__ (__printf__, 2, 
3)));
  [...]
};
struct Obj {
  Obj () { throw Exception ("%s: error", typeid (this).name()); }
};
try { Obj a; } catch (std::exception &e) {
  printf ("exception: what(): %s\n", e.what());
}

it does however produce garbage (with 3.3 and 3.4) instead of Obj's typename:
exception: what(): 44`l$@: error

i have attached a full test case with 2 throw statements that
will both produce a garbage typename. i'm not sure this isn't
a compiler bug, so any help is apprechiated.

---
ciaoTJ
#include <stdio.h>
#include <string.h>
#include <malloc.h>
#include <stdarg.h>
#include <typeinfo>

struct Exception : std::exception {
  Exception (const char *format, ...) __attribute__((__format__ (__printf__, 2, 3)));
  virtual const char* what() const throw() { return reason ? reason : "out of memory"; }
  Exception (const Exception &e) : reason (e.reason ? strdup (e.reason) : NULL) {}
  ~Exception() throw() { if (reason) free (reason); }
private:
  char *reason;
  Exception& operator= (const Exception&);
};

Exception::Exception (const char *format, ...)
{
  va_list args;
  va_start (args, format);
  reason = NULL;
  if (asprintf (&reason, format, args) < 0 || !reason)
    reason = NULL; /* indicate "out of memory" */
  va_end (args);
}

struct Obj {
  Obj ()
  {
    const char *thisname = typeid (this).name();
    printf ("A: thisname: %s\n", thisname);
    throw Exception ("%s: error", typeid (this).name());
    throw Exception ("%s: error", thisname);
  }
};

int
main (int   argc,
      char *argv[])
{
  try {
    Obj a;
  } catch (std::exception &e) {
    printf ("exception: what(): %s\n", e.what());
  }
  return 0;
}