hw-tree.c

这个是LINUX下的GDB调度工具的源码

/* The common simulator framework for GDB, the GNU Debugger.

   Copyright 2002 Free Software Foundation, Inc.

   Contributed by Andrew Cagney and Red Hat.

   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 2 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, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */


#include "hw-main.h"
#include "hw-base.h"
#include "hw-tree.h"

#include "sim-io.h"
#include "sim-assert.h"

#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif

#ifdef HAVE_STRING_H
#include <string.h>
#else
#ifdef HAVE_STRINGS_H
#include <strings.h>
#endif
#endif

#include <ctype.h>

/* manipulate/lookup device names */

typedef struct _name_specifier {
  
  /* components in the full length name */
  char *path;
  char *property;
  char *value;
  
  /* current device */
  char *family;
  char *name;
  char *unit;
  char *args;
  
  /* previous device */
  char *last_name;
  char *last_family;
  char *last_unit;
  char *last_args;
  
  /* work area */
  char buf[1024];
  
} name_specifier;



/* Given a device specifier, break it up into its main components:
   path (and if present) property name and property value. */

static int
split_device_specifier (struct hw *current,
			const char *device_specifier,
			name_specifier *spec)
{
  char *chp = NULL;
  
  /* expand any leading alias if present */
  if (current != NULL
      && *device_specifier != '\0'
      && *device_specifier != '.'
      && *device_specifier != '/')
    {
      struct hw *aliases = hw_tree_find_device (current, "/aliases");
      char alias[32];
      int len = 0;
      while (device_specifier[len] != '\0'
	     && device_specifier[len] != '/'
	     && device_specifier[len] != ':'
	     && !isspace (device_specifier[len]))
	{
	  alias[len] = device_specifier[len];
	  len++;
	  if (len >= sizeof(alias))
	    hw_abort (NULL, "split_device_specifier: buffer overflow");
	}
      alias[len] = '\0';
      if (aliases != NULL
	  && hw_find_property (aliases, alias))
	{
	  strcpy (spec->buf, hw_find_string_property(aliases, alias));
	  strcat (spec->buf, device_specifier + len);
	}
      else
	{
	  strcpy (spec->buf, device_specifier);
	}
    }
  else
    {
      strcpy(spec->buf, device_specifier);
    }
  
  /* check no overflow */
  if (strlen(spec->buf) >= sizeof(spec->buf))
    hw_abort (NULL, "split_device_specifier: buffer overflow\n");
  
  /* strip leading spaces */
  chp = spec->buf;
  while (*chp != '\0' && isspace(*chp))
    chp++;
  if (*chp == '\0')
    return 0;
  
  /* find the path and terminate it with null */
  spec->path = chp;
  while (*chp != '\0' && !isspace(*chp))
    chp++;
  if (*chp != '\0')
    {
      *chp = '\0';
      chp++;
    }
  
  /* and any value */
  while (*chp != '\0' && isspace(*chp))
    chp++;
  spec->value = chp;
  
  /* now go back and chop the property off of the path */
  if (spec->value[0] == '\0')
    {
      spec->property = NULL; /*not a property*/
      spec->value = NULL;
    }
  else if (spec->value[0] == '>'
	   || spec->value[0] == '<')
    {
      /* an interrupt spec */
      spec->property = NULL;
    }
  else {
    chp = strrchr(spec->path, '/');
    if (chp == NULL)
      {
	spec->property = spec->path;
	spec->path = strchr(spec->property, '\0');
      }
    else {
      *chp = '\0';
      spec->property = chp+1;
    }
  }
  
  /* and mark the rest as invalid */
  spec->name = NULL;
  spec->family = NULL;
  spec->unit = NULL;
  spec->args = NULL;
  spec->last_name = NULL;
  spec->last_family = NULL;
  spec->last_unit = NULL;
  spec->last_args = NULL;
  
  return 1;
}


/* given a device specifier break it up into its main components -
   path and property name - assuming that the last `device' is a
   property name. */

static int
split_property_specifier (struct hw *current,
			  const char *property_specifier,
			  name_specifier *spec)
{
  if (split_device_specifier (current, property_specifier, spec))
    {
      if (spec->property == NULL)
	{
	  /* force the last name to be a property name */
	  char *chp = strrchr (spec->path, '/');
	  if (chp == NULL)
	    {
	      spec->property = spec->path;
	      spec->path = strrchr (spec->property, '\0');;
	    }
	  else
	    {
	      *chp = '\0';
	      spec->property = chp + 1;
	    }
	}
      return 1;
    }
  else
    return 0;
}


/* device the next device name and split it up, return 0 when no more
   names to struct hw */

static int
split_device_name (name_specifier *spec)
{
  char *chp;
  /* remember what came before */
  spec->last_name = spec->name;
  spec->last_family = spec->family;
  spec->last_unit = spec->unit;
  spec->last_args = spec->args;
  /* finished? */
  if (spec->path[0] == '\0')
    {
      spec->name = NULL;
      spec->family = NULL;
      spec->unit = NULL;
      spec->args = NULL;
      return 0;
    }
  /* break the current device spec from the path */
  spec->name = spec->path;
  chp = strchr (spec->name, '/');
  if (chp == NULL)
    spec->path = strchr (spec->name, '\0');
  else 
    {
      spec->path = chp+1;
      *chp = '\0';
    }
  /* break out the base */
  if (spec->name[0] == '(')
    {
      chp = strchr(spec->name, ')');
      if (chp == NULL)
	{
	  spec->family = spec->name;
	}
      else
	{
	  *chp = '\0';
	  spec->family = spec->name + 1;
	  spec->name = chp + 1;
	}
    }
  else
    {
      spec->family = spec->name;
    }
  /* now break out the unit */
  chp = strchr(spec->name, '@');
  if (chp == NULL)
    {
      spec->unit = NULL;
      chp = spec->name;
    }
  else
    {
      *chp = '\0';
      chp += 1;
      spec->unit = chp;
    }
  /* finally any args */
  chp = strchr(chp, ':');
  if (chp == NULL)
    spec->args = NULL;
  else
    {
      *chp = '\0';
      spec->args = chp+1;
    }
  return 1;
}


/* device the value, returning the next non-space token */

static char *
split_value (name_specifier *spec)
{
  char *token;
  if (spec->value == NULL)
    return NULL;
  /* skip leading white space */
  while (isspace (spec->value[0]))
    spec->value++;
  if (spec->value[0] == '\0')
    {
      spec->value = NULL;
      return NULL;
    }
  token = spec->value;
  /* find trailing space */
  while (spec->value[0] != '\0' && !isspace (spec->value[0]))
    spec->value++;
  /* chop this value out */
  if (spec->value[0] != '\0')
    {
      spec->value[0] = '\0';
      spec->value++;
    }
  return token;
}



/* traverse the path specified by spec starting at current */

static struct hw *
split_find_device (struct hw *current,
		   name_specifier *spec)
{
  /* strip off (and process) any leading ., .., ./ and / */
  while (1)
    {
      if (strncmp (spec->path, "/", strlen ("/")) == 0)
	{
	  /* cd /... */
	  while (current != NULL && hw_parent (current) != NULL)
	    current = hw_parent (current);
	  spec->path += strlen ("/");
	}
      else if (strncmp (spec->path, "./", strlen ("./")) == 0)
	{
	  /* cd ./... */
	  current = current;
	  spec->path += strlen ("./");
	}
      else if (strncmp (spec->path, "../", strlen ("../")) == 0)
	{
	  /* cd ../... */
	  if (current != NULL && hw_parent (current) != NULL)
	    current = hw_parent (current);
	  spec->path += strlen ("../");
	}
      else if (strcmp (spec->path, ".") == 0)
	{
	  /* cd . */
	  current = current;
	  spec->path += strlen (".");
	}
      else if (strcmp (spec->path, "..") == 0)
	{
	  /* cd .. */
	  if (current != NULL && hw_parent (current) != NULL)
	    current = hw_parent (current);
	  spec->path += strlen ("..");
	}
      else
	break;
    }
  
  /* now go through the path proper */
  
  if (current == NULL)
    {
      split_device_name (spec);
      return NULL;
    }
  
  while (split_device_name (spec))
    {
      struct hw *child;
      for (child = hw_child (current);
	   child != NULL; child = hw_sibling (child))
	{
	  if (strcmp (spec->name, hw_name (child)) == 0)
	    {
	      if (spec->unit == NULL)
		break;
	      else
		{
		  hw_unit phys;
		  hw_unit_decode (current, spec->unit, &phys);
		  if (memcmp (&phys, hw_unit_address (child),
			      sizeof (hw_unit)) == 0)
		    break;
		}
	    }
	}
      if (child == NULL)
	return current; /* search failed */
      current = child;
    }
  
  return current;
}


static struct hw *
split_fill_path (struct hw *current,
		 const char *device_specifier,
		 name_specifier *spec)
{
  /* break it up */
  if (!split_device_specifier (current, device_specifier, spec))
    hw_abort (current, "error parsing %s\n", device_specifier);
  
  /* fill our tree with its contents */
  current = split_find_device (current, spec);
  
  /* add any additional devices as needed */
  if (spec->name != NULL)
    {
      do
	{
	  if (current != NULL && !hw_finished_p (current))
	    hw_finish (current);
	  current = hw_create (NULL,
			       current,
			       spec->family,
			       spec->name,
			       spec->unit,
			       spec->args);
	}
      while (split_device_name (spec));
    }
  
  return current;
}


/* <non-white-space> */

static const char *
skip_token(const char *chp)
{
  while (!isspace(*chp) && *chp != '\0')
    chp++;
  while (isspace(*chp) && *chp != '\0')
    chp++;
  return chp;