2.5. Log Functions

The logfunctions class is one of the base classes of Bochs. It supports 4 log levels (debug, info, error, panic) and 4 possible "actions" that can be done when a log event occurs. Most of the higher level C++ classes of Bochs inherit this class to make the logging configuration per object (here called "module") possible. In the Bochs sources the log events appear as macros (BX_DEBUG, BX_INFO, BX_ERROR, BX_PANIC) and they call the related logfunction methods, unless the symbol BX_NO_LOGGING is set to 1. This is the definition in bochs.h:

typedef class BOCHSAPI logfunctions
{
  char *name;
  char *prefix;
  int onoff[N_LOGLEV];
  class iofunctions *logio;
  // default log actions for all devices, declared and initialized
  // in logio.cc.
  BOCHSAPI_CYGONLY static int default_onoff[N_LOGLEV];
public:
  logfunctions(void);
  logfunctions(class iofunctions *);
 ~logfunctions(void);

  void info(const char *fmt, ...)   BX_CPP_AttrPrintf(2, 3);
  void error(const char *fmt, ...)  BX_CPP_AttrPrintf(2, 3);
  void panic(const char *fmt, ...)  BX_CPP_AttrPrintf(2, 3);
  void ldebug(const char *fmt, ...) BX_CPP_AttrPrintf(2, 3);
  void fatal (const char *prefix, const char *fmt, va_list ap, int exit_status);
  void ask (int level, const char *prefix, const char *fmt, va_list ap);
  void put(const char *p);
  void put(const char *n, const char *p);
  void setio(class iofunctions *);
  void setonoff(int loglev, int value) {
    assert (loglev >= 0 && loglev < N_LOGLEV);
    onoff[loglev] = value;
  }
  const char *get_name() const { return name; }
  const char *getprefix() const { return prefix; }
  int getonoff(int level) const {
    assert (level>=0 && level<N_LOGLEV);
    return onoff[level];
  }
  static void set_default_action(int loglev, int action) {
    assert (loglev >= 0 && loglev < N_LOGLEV);
    assert (action >= 0 && action < N_ACT);
    default_onoff[loglev] = action;
  }
  static int get_default_action(int loglev) {
    assert (loglev >= 0 && loglev < N_LOGLEV);
    return default_onoff[loglev];
  }
} logfunc_t;