text: /* Register support routines for the remote server for GDB.
     Copyright (C) 2001-2017 Free Software Foundation, Inc.
  
     This file is part of GDB.
  
     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/>.  */
  
  #include "server.h"
  #include "regdef.h"
  #include "gdbthread.h"
  #include "tdesc.h"
  #include "rsp-low.h"
  #ifndef IN_PROCESS_AGENT
  
  struct regcache *
  get_thread_regcache (struct thread_info *thread, int fetch)
  {
    struct regcache *regcache;
  
    regcache = inferior_regcache_data (thread);
  
    /* Threads' regcaches are created lazily, because biarch targets add
       the main thread/lwp before seeing it stop for the first time, and
       it is only after the target sees the thread stop for the first
       time that the target has a chance of determining the process's
       architecture.  IOW, when we first add the process's main thread
       we don't know which architecture/tdesc its regcache should
       have.  */
    if (regcache == NULL)
      {
        struct process_info *proc = get_thread_process (thread);
  
        gdb_assert (proc->tdesc != NULL);
  
        regcache = new_register_cache (proc->tdesc);
        set_inferior_regcache_data (thread, regcache);
      }
  
    if (fetch && regcache->registers_valid == 0)
      {
        struct thread_info *saved_thread = current_thread;
  
        current_thread = thread;
        /* Invalidate all registers, to prevent stale left-overs.  */
        memset (regcache->register_status, REG_UNAVAILABLE,
  	      regcache->tdesc->num_registers);
        fetch_inferior_registers (regcache, -1);
        current_thread = saved_thread;
        regcache->registers_valid = 1;
      }
  
    return regcache;
  }
  
  /* See common/common-regcache.h.  */
  
  struct regcache *
  get_thread_regcache_for_ptid (ptid_t ptid)
  {
    return get_thread_regcache (find_thread_ptid (ptid), 1);
  }
  
  void
  regcache_invalidate_thread (struct thread_info *thread)
  {
    struct regcache *regcache;
  
    regcache = inferior_regcache_data (thread);
  
    if (regcache == NULL)
      return;
  
    if (regcache->registers_valid)
      {
        struct thread_info *saved_thread = current_thread;
  
        current_thread = thread;
        store_inferior_registers (regcache, -1);
        current_thread = saved_thread;
      }
  
    regcache->registers_valid = 0;
  }
  
  static int
  regcache_invalidate_one (struct inferior_list_entry *entry,
  			 void *pid_p)
  {
    struct thread_info *thread = (struct thread_info *) entry;
    int pid = *(int *) pid_p;
  
    /* Only invalidate the regcaches of threads of this process.  */
    if (ptid_get_pid (entry->id) == pid)
      regcache_invalidate_thread (thread);
  
    return 0;
  }
  
  /* See regcache.h.  */
  
  void
  regcache_invalidate_pid (int pid)
  {
    find_inferior (&all_threads, regcache_invalidate_one, &pid);
  }
  
  /* See regcache.h.  */
  
  void
  regcache_invalidate (void)
  {
    /* Only update the threads of the current process.  */
    int pid = ptid_get_pid (current_thread->entry.id);
  
    regcache_invalidate_pid (pid);
  }
  
  #endif
  
  struct regcache *
  init_register_cache (struct regcache *regcache,
  		     const struct target_desc *tdesc,
  		     unsigned char *regbuf)
  {
    if (regbuf == NULL)
      {
  #ifndef IN_PROCESS_AGENT
        /* Make sure to zero-initialize the register cache when it is
  	 created, in case there are registers the target never
  	 fetches.  This way they'll read as zero instead of
  	 garbage.  */
        regcache->tdesc = tdesc;
        regcache->registers
  	= (unsigned char *) xcalloc (1, tdesc->registers_size);
        regcache->registers_owned = 1;
        regcache->register_status
  	= (unsigned char *) xmalloc (tdesc->num_registers);
        memset ((void *) regcache->register_status, REG_UNAVAILABLE,
  	      tdesc->num_registers);
  #else
        gdb_assert_not_reached ("can't allocate memory from the heap");
  #endif
      }
    else
      {
        regcache->tdesc = tdesc;
        regcache->registers = regbuf;
        regcache->registers_owned = 0;
  #ifndef IN_PROCESS_AGENT
        regcache->register_status = NULL;
  #endif
      }
  
    regcache->registers_valid = 0;
  
    return regcache;
  }
  
  #ifndef IN_PROCESS_AGENT
  
  struct regcache *
  new_register_cache (const struct target_desc *tdesc)
  {
    struct regcache *regcache = XCNEW (struct regcache);
  
    gdb_assert (tdesc->registers_size != 0);
  
    return init_register_cache (regcache, tdesc, NULL);
  }
  
  void
  free_register_cache (struct regcache *regcache)
  {
    if (regcache)
      {
        if (regcache->registers_owned)
  	free (regcache->registers);
        free (regcache->register_status);
        free (regcache);
      }
  }
  
  #endif
  
  void
  regcache_cpy (struct regcache *dst, struct regcache *src)
  {
    gdb_assert (src != NULL && dst != NULL);
    gdb_assert (src->tdesc == dst->tdesc);
    gdb_assert (src != dst);
  
    memcpy (dst->registers, src->registers, src->tdesc->registers_size);
  #ifndef IN_PROCESS_AGENT
    if (dst->register_status != NULL && src->register_status != NULL)
      memcpy (dst->register_status, src->register_status,
  	    src->tdesc->num_registers);
  #endif
    dst->registers_valid = src->registers_valid;
  }
  
  
  #ifndef IN_PROCESS_AGENT
  
  void
  registers_to_string (struct regcache *regcache, char *buf)
  {
    unsigned char *registers = regcache->registers;
    const struct target_desc *tdesc = regcache->tdesc;
    int i;
  
    for (i = 0; i < tdesc->num_registers; i++)
      {
        if (regcache->register_status[i] == REG_VALID)
  	{
  	  bin2hex (registers, buf, register_size (tdesc, i));
  	  buf += register_size (tdesc, i) * 2;
  	}
        else
  	{
  	  memset (buf, 'x', register_size (tdesc, i) * 2);
  	  buf += register_size (tdesc, i) * 2;
  	}
        registers += register_size (tdesc, i);
      }
    *buf = '\0';
  }
  
  void
  registers_from_string (struct regcache *regcache, char *buf)
  {
    int len = strlen (buf);
    unsigned char *registers = regcache->registers;
    const struct target_desc *tdesc = regcache->tdesc;
  
    if (len != tdesc->registers_size * 2)
      {
        warning ("Wrong sized register packet (expected %d bytes, got %d)",
  	       2 * tdesc->registers_size, len);
        if (len > tdesc->registers_size * 2)
  	len = tdesc->registers_size * 2;
      }
    hex2bin (buf, registers, len / 2);
  }
  
  int
  find_regno (const struct target_desc *tdesc, const char *name)
  {
    int i;
  
    for (i = 0; i < tdesc->num_registers; i++)
      if (strcmp (name, tdesc->reg_defs[i].name) == 0)
        return i;
    internal_error (__FILE__, __LINE__, "Unknown register %s requested",
  		  name);
  }
  
  struct reg *
  find_register_by_number (const struct target_desc *tdesc, int n)
  {
    return &tdesc->reg_defs[n];
  }
  
  #endif
  
  #ifndef IN_PROCESS_AGENT
  static void
  free_register_cache_thread (struct thread_info *thread)
  {
    struct regcache *regcache = inferior_regcache_data (thread);
  
    if (regcache != NULL)
      {
        regcache_invalidate_thread (thread);
        free_register_cache (regcache);
        set_inferior_regcache_data (thread, NULL);
      }
  }
  
  static void
  free_register_cache_thread_one (struct inferior_list_entry *entry)
  {
    struct thread_info *thread = (struct thread_info *) entry;
  
    free_register_cache_thread (thread);
  }
  
  void
  regcache_release (void)
  {
    /* Flush and release all pre-existing register caches.  */
    for_each_inferior (&all_threads, free_register_cache_thread_one);
  }
  #endif
  
  int
  register_cache_size (const struct target_desc *tdesc)
  {
    return tdesc->registers_size;
  }
  
  int
  register_size (const struct target_desc *tdesc, int n)
  {
    return tdesc->reg_defs[n].size / 8;
  }
  
  /* See common/common-regcache.h.  */
  
  int
  regcache_register_size (const struct regcache *regcache, int n)
  {
    return register_size (regcache->tdesc, n);
  }
  
  static unsigned char *
  register_data (struct regcache *regcache, int n, int fetch)
  {
    return regcache->registers + regcache->tdesc->reg_defs[n].offset / 8;
  }
  
  /* Supply register N, whose contents are stored in BUF, to REGCACHE.
     If BUF is NULL, the register's value is recorded as
     unavailable.  */
  
  void
  supply_register (struct regcache *regcache, int n, const void *buf)
  {
    if (buf)
      {
        memcpy (register_data (regcache, n, 0), buf,
  	      register_size (regcache->tdesc, n));
  #ifndef IN_PROCESS_AGENT
        if (regcache->register_status != NULL)
  	regcache->register_status[n] = REG_VALID;
  #endif
      }
    else
      {
        memset (register_data (regcache, n, 0), 0,
  	      register_size (regcache->tdesc, n));
  #ifndef IN_PROCESS_AGENT
        if (regcache->register_status != NULL)
  	regcache->register_status[n] = REG_UNAVAILABLE;
  #endif
      }
  }
  
  /* Supply register N with value zero to REGCACHE.  */
  
  void
  supply_register_zeroed (struct regcache *regcache, int n)
  {
    memset (register_data (regcache, n, 0), 0,
  	  register_size (regcache->tdesc, n));
  #ifndef IN_PROCESS_AGENT
    if (regcache->register_status != NULL)
      regcache->register_status[n] = REG_VALID;
  #endif
  }
  
  /* Supply the whole register set whose contents are stored in BUF, to
     REGCACHE.  If BUF is NULL, all the registers' values are recorded
     as unavailable.  */
  
  void
  supply_regblock (struct regcache *regcache, const void *buf)
  {
    if (buf)
      {
        const struct target_desc *tdesc = regcache->tdesc;
  
        memcpy (regcache->registers, buf, tdesc->registers_size);
  #ifndef IN_PROCESS_AGENT
        {
  	int i;
  
  	for (i = 0; i < tdesc->num_registers; i++)
  	  regcache->register_status[i] = REG_VALID;
        }
  #endif
      }
    else
      {
        const struct target_desc *tdesc = regcache->tdesc;
  
        memset (regcache->registers, 0, tdesc->registers_size);
  #ifndef IN_PROCESS_AGENT
        {
  	int i;
  
  	for (i = 0; i < tdesc->num_registers; i++)
  	  regcache->register_status[i] = REG_UNAVAILABLE;
        }
  #endif
      }
  }
  
  #ifndef IN_PROCESS_AGENT
  
  void
  supply_register_by_name (struct regcache *regcache,
  			 const char *name, const void *buf)
  {
    supply_register (regcache, find_regno (regcache->tdesc, name), buf);
  }
  
  #endif
  
  void
  collect_register (struct regcache *regcache, int n, void *buf)
  {
    memcpy (buf, register_data (regcache, n, 1),
  	  register_size (regcache->tdesc, n));
  }
  
  enum register_status
  regcache_raw_read_unsigned (struct regcache *regcache, int regnum,
  			    ULONGEST *val)
  {
    int size;
  
    gdb_assert (regcache != NULL);
    gdb_assert (regnum >= 0 && regnum < regcache->tdesc->num_registers);
  
    size = register_size (regcache->tdesc, regnum);
  
    if (size > (int) sizeof (ULONGEST))
      error (_("That operation is not available on integers of more than"
              "%d bytes."),
            (int) sizeof (ULONGEST));
  
    *val = 0;
    collect_register (regcache, regnum, val);
  
    return REG_VALID;
  }
  
  #ifndef IN_PROCESS_AGENT
  
  void
  collect_register_as_string (struct regcache *regcache, int n, char *buf)
  {
    bin2hex (register_data (regcache, n, 1), buf,
  	   register_size (regcache->tdesc, n));
  }
  
  void
  collect_register_by_name (struct regcache *regcache,
  			  const char *name, void *buf)
  {
    collect_register (regcache, find_regno (regcache->tdesc, name), buf);
  }
  
  /* Special handling for register PC.  */
  
  CORE_ADDR
  regcache_read_pc (struct regcache *regcache)
  {
    CORE_ADDR pc_val;
  
    if (the_target->read_pc)
      pc_val = the_target->read_pc (regcache);
    else
      internal_error (__FILE__, __LINE__,
  		    "regcache_read_pc: Unable to find PC");
  
    return pc_val;
  }
  
  void
  regcache_write_pc (struct regcache *regcache, CORE_ADDR pc)
  {
    if (the_target->write_pc)
      the_target->write_pc (regcache, pc);
    else
      internal_error (__FILE__, __LINE__,
  		    "regcache_write_pc: Unable to update PC");
  }
  
  #endif
  