sim/common/sim-engine.h

/* Generic simulator halt/resume.
   Copyright (C) 1997-2025 Free Software Foundation, Inc.
   Contributed by Cygnus Support.

This file is part of GDB, the GNU debugger.

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

#ifndef SIM_ENGINE_H
#define SIM_ENGINE_H

#include <stdarg.h>

#include "ansidecl.h"

typedef struct _sim_engine sim_engine;
struct _sim_engine
{
  void *jmpbuf;
  sim_cpu *last_cpu;
  sim_cpu *next_cpu;
  int nr_cpus;
  enum sim_stop reason;
  sim_event *stepper;
  int sigrc;
};



/* jmpval: 0 (initial use) start simulator
           1               halt simulator
           2               restart simulator
   This is required by the ISO C standard (the only time 0 is returned
   is at the initial call to setjmp). */

enum {
  sim_engine_start_jmpval,
  sim_engine_halt_jmpval,
  sim_engine_restart_jmpval,
};


/* Get/set the run state of CPU to REASON/SIGRC.
   REASON/SIGRC are the values returned by sim_stop_reason.  */
void sim_engine_get_run_state (SIM_DESC sd, enum sim_stop *reason, int *sigrc);
void sim_engine_set_run_state (SIM_DESC sd, enum sim_stop reason, int sigrc);


/* Halt the simulator *now* */

extern void sim_engine_halt
(SIM_DESC sd,
 sim_cpu *last_cpu, /* NULL -> in event-mgr */
 sim_cpu *next_cpu, /* NULL -> succ (last_cpu) or event-mgr */
 sim_cia cia,
 enum sim_stop reason,
 int sigrc) ATTRIBUTE_NORETURN;

/* Halt hook - allow target specific operation when halting a
   simulator */

#if !defined (SIM_ENGINE_HALT_HOOK)
#define SIM_ENGINE_HALT_HOOK(SD, LAST_CPU, CIA) \
if ((LAST_CPU) != NULL) CPU_PC_SET (LAST_CPU, CIA)
#endif

/* NB: If a port uses the SIM_CPU_EXCEPTION_* hooks, the default
   SIM_ENGINE_HALT_HOOK and SIM_ENGINE_RESUME_HOOK must not be used.
   They conflict in that the PC set by the HALT_HOOK may overwrite the
   proper one, as intended to be saved by the EXCEPTION_TRIGGER
   hook. */


/* restart the simulator *now* */

extern void sim_engine_restart
(SIM_DESC sd,
 sim_cpu *last_cpu, /* NULL -> in event-mgr */
 sim_cpu *next_cpu, /* NULL -> succ (last_cpu) or event-mgr */
 sim_cia cia) ATTRIBUTE_NORETURN;

/* Restart hook - allow target specific operation when restarting a
   simulator */

#if !defined (SIM_ENGINE_RESTART_HOOK)
#define SIM_ENGINE_RESTART_HOOK(SD, LAST_CPU, CIA) SIM_ENGINE_HALT_HOOK(SD, LAST_CPU, CIA)
#endif




/* Abort the simulator *now*.

   This function is NULL safe.  It can be called when either of SD or
   CIA are NULL.

   This function is setjmp/longjmp safe.  It can be called when of
   the sim_engine setjmp/longjmp buffer has not been established.

   Simulators that are using components such as sim-core but are not
   yet using this sim-engine module should link in file sim-abort.o
   which implements a non setjmp/longjmp version of
   sim_engine_abort. */

extern void sim_engine_abort
(SIM_DESC sd,
 sim_cpu *cpu,
 sim_cia cia,
 const char *fmt,
 ...) ATTRIBUTE_PRINTF (4, 5) ATTRIBUTE_NORETURN;

extern void sim_engine_vabort
(SIM_DESC sd,
 sim_cpu *cpu,
 sim_cia cia,
 const char *fmt,
 va_list ap) ATTRIBUTE_PRINTF (4, 0) ATTRIBUTE_NORETURN;

/* No abort hook - when possible this function exits using the
   engine_halt function (and SIM_ENGINE_HALT_HOOK). */




/* Called by the generic sim_resume to run the simulation within the
   above safety net.

   An example implementation of sim_engine_run can be found in the
   file sim-run.c */

extern void sim_engine_run
(SIM_DESC sd,
 int next_cpu_nr,
 int nr_cpus,
 int siggnal); /* most simulators ignore siggnal */



/* Determine the state of next/last cpu when the simulator was last
   halted - a value >= MAX_NR_PROCESSORS indicates that the
   event-queue was next/last. */

extern int sim_engine_next_cpu_nr (SIM_DESC sd);
extern int sim_engine_last_cpu_nr (SIM_DESC sd);
extern int sim_engine_nr_cpus (SIM_DESC sd);


#endif