factor/vm/errors.cpp

#include "master.hpp"

namespace factor {

bool factor_vm::fatal_erroring_p;

static inline void fa_diddly_atal_error() {
  printf("fatal_error in fatal_error!\n");
  breakpoint();
  ::_exit(86);
}

void fatal_error(const char* msg, cell tagged) {
  if (factor_vm::fatal_erroring_p)
    fa_diddly_atal_error();

  factor_vm::fatal_erroring_p = true;

  std::cout << "fatal_error: " << msg;
  std::cout << ": " << (void*)tagged;
  std::cout << std::endl;
  abort();
}

void critical_error(const char* msg, cell tagged) {
  std::cout << "You have triggered a bug in Factor. Please report.\n";
  std::cout << "critical_error: " << msg;
  std::cout << ": " << std::hex << tagged << std::dec;
  std::cout << std::endl;
  current_vm()->factorbug();
}

void out_of_memory(const char *msg) {
  std::cout << "Out of memory: " << msg << "\n\n";
  current_vm()->dump_generations(std::cout);
  abort();
}

/* Allocates memory */
void factor_vm::general_error(vm_error_type error, cell arg1_, cell arg2_) {

  data_root<object> arg1(arg1_, this);
  data_root<object> arg2(arg2_, this);

  faulting_p = true;

  /* If we had an underflow or overflow, data or retain stack
     pointers might be out of bounds, so fix them before allocating
     anything */
  ctx->fix_stacks();

  /* If error was thrown during heap scan, we re-enable the GC */
  gc_off = false;

  /* If the error handler is set, we rewind any C stack frames and
     pass the error to user-space. */
  if (!current_gc && to_boolean(special_objects[ERROR_HANDLER_QUOT])) {
#ifdef FACTOR_DEBUG
    /* Doing a GC here triggers all kinds of funny errors */
    primitive_compact_gc();
#endif

    /* Now its safe to allocate and GC */
    cell error_object =
        allot_array_4(special_objects[OBJ_ERROR], tag_fixnum(error),
                      arg1.value(), arg2.value());
    ctx->push(error_object);

    /* Clear the data roots since arg1 and arg2's destructors won't be
       called. */
    data_roots.clear();

    /* The unwind-native-frames subprimitive will clear faulting_p
       if it was successfully reached. */
    unwind_native_frames(special_objects[ERROR_HANDLER_QUOT],
                         ctx->callstack_top);
  } /* Error was thrown in early startup before error handler is set, so just
       crash. */
  else {
    std::cout << "You have triggered a bug in Factor. Please report.\n";
    std::cout << "error: " << error << std::endl;
    std::cout << "arg 1: ";
    print_obj(std::cout, arg1.value());
    std::cout << std::endl;
    std::cout << "arg 2: ";
    print_obj(std::cout, arg2.value());
    std::cout << std::endl;
    factorbug();
    abort();
  }
}

/* Allocates memory */
void factor_vm::type_error(cell type, cell tagged) {
  general_error(ERROR_TYPE, tag_fixnum(type), tagged);
}

/* Allocates memory */
void factor_vm::not_implemented_error() {
  general_error(ERROR_NOT_IMPLEMENTED, false_object, false_object);
}

void factor_vm::verify_memory_protection_error(cell addr) {
  /* Called from the OS-specific top halves of the signal handlers to
     make sure it's safe to dispatch to memory_protection_error */
  if (fatal_erroring_p)
    fa_diddly_atal_error();
  if (faulting_p && !code->safepoint_p(addr))
    fatal_error("Double fault", addr);
  else if (fep_p)
    fatal_error("Memory protection fault during low-level debugger", addr);
  else if (atomic::load(&current_gc_p))
    fatal_error("Memory protection fault during gc", addr);
}

/* Allocates memory */
void factor_vm::memory_protection_error(cell pc, cell addr) {
  if (code->safepoint_p(addr))
    safepoint.handle_safepoint(this, pc);
  else if (ctx->datastack_seg->underflow_p(addr))
    general_error(ERROR_DATASTACK_UNDERFLOW, false_object, false_object);
  else if (ctx->datastack_seg->overflow_p(addr))
    general_error(ERROR_DATASTACK_OVERFLOW, false_object, false_object);
  else if (ctx->retainstack_seg->underflow_p(addr))
    general_error(ERROR_RETAINSTACK_UNDERFLOW, false_object, false_object);
  else if (ctx->retainstack_seg->overflow_p(addr))
    general_error(ERROR_RETAINSTACK_OVERFLOW, false_object, false_object);
  else if (ctx->callstack_seg->underflow_p(addr))
    general_error(ERROR_CALLSTACK_OVERFLOW, false_object, false_object);
  else if (ctx->callstack_seg->overflow_p(addr))
    general_error(ERROR_CALLSTACK_UNDERFLOW, false_object, false_object);
  else
    general_error(ERROR_MEMORY, from_unsigned_cell(addr), false_object);
}

/* Allocates memory */
void factor_vm::signal_error(cell signal) {
  general_error(ERROR_SIGNAL, from_unsigned_cell(signal), false_object);
}

/* Allocates memory */
void factor_vm::divide_by_zero_error() {
  general_error(ERROR_DIVIDE_BY_ZERO, false_object, false_object);
}

/* Allocates memory */
void factor_vm::fp_trap_error(unsigned int fpu_status) {
  general_error(ERROR_FP_TRAP, tag_fixnum(fpu_status), false_object);
}

/* For testing purposes */
/* Allocates memory */
void factor_vm::primitive_unimplemented() { not_implemented_error(); }

/* Allocates memory */
void factor_vm::memory_signal_handler_impl() {
  memory_protection_error(signal_fault_pc, signal_fault_addr);
  if (!signal_resumable) {
    /* In theory we should only get here if the callstack overflowed during a
       safepoint */
    general_error(ERROR_CALLSTACK_OVERFLOW, false_object, false_object);
  }
}

/* Allocates memory */
void memory_signal_handler_impl() {
  current_vm()->memory_signal_handler_impl();
}

/* Allocates memory */
void factor_vm::synchronous_signal_handler_impl() {
  signal_error(signal_number);
}

/* Allocates memory */
void synchronous_signal_handler_impl() {
  current_vm()->synchronous_signal_handler_impl();
}

/* Allocates memory (fp_trap_error())*/
void factor_vm::fp_signal_handler_impl() {
  /* Clear pending exceptions to avoid getting stuck in a loop */
  set_fpu_state(get_fpu_state());

  fp_trap_error(signal_fpu_status);
}

/* Allocates memory */
void fp_signal_handler_impl() { current_vm()->fp_signal_handler_impl(); }
}