slstruct.c

一个C格式的脚本处理函数库源代码,可让你的C程序具有执行C格式的脚本文件

/* Structure type implementation */
/* Copyright (c) 1998, 1999, 2001, 2002, 2003 John E. Davis
 * This file is part of the S-Lang library.
 *
 * You may distribute under the terms of either the GNU General Public
 * License or the Perl Artistic License.
 */
#include "slinclud.h"

/* #define SL_APP_WANTS_FOREACH */
#include "slang.h"
#include "_slang.h"

void _SLstruct_delete_struct (_SLang_Struct_Type *s)
{
   _SLstruct_Field_Type *field, *field_max;

   if (s == NULL) return;

   if (s->num_refs > 1)
     {
	s->num_refs -= 1;
	return;
     }

   field = s->fields;
   if (field != NULL)
     {
	field_max = field + s->nfields;

	while (field < field_max)
	  {
	     SLang_free_object (&field->obj);
	     SLang_free_slstring (field->name);   /* could be NULL */
	     field++;
	  }
	SLfree ((char *) s->fields);
     }
   SLfree ((char *) s);
}

static _SLang_Struct_Type *allocate_struct (unsigned int nfields)
{
   _SLang_Struct_Type *s;
   _SLstruct_Field_Type *f;
   unsigned int i, size;

   s = (_SLang_Struct_Type *) SLmalloc (sizeof (_SLang_Struct_Type));
   if (s == NULL) return NULL;

   SLMEMSET((char *) s, 0, sizeof (_SLang_Struct_Type));

   size = nfields * sizeof(_SLstruct_Field_Type);
   if (NULL == (f = (_SLstruct_Field_Type *) SLmalloc (size)))
     {
	SLfree ((char *) s);
	return NULL;
     }
   SLMEMSET ((char *) f, 0, size);
   s->nfields = nfields;
   s->fields = f;

   /* By default, all structs will be created with elements set to NULL.  I
    * do not know whether or not it is better to use SLANG_UNDEFINED_TYPE.
    */
   for (i = 0; i < nfields; i++)
     f[i].obj.data_type = SLANG_NULL_TYPE;

   return s;
}

static int push_struct_of_type (unsigned char type, _SLang_Struct_Type *s)
{
   SLang_Object_Type obj;

   obj.data_type = type;
   obj.v.struct_val = s;
   s->num_refs += 1;

   if (0 == SLang_push (&obj))
     return 0;

   s->num_refs -= 1;
   return -1;
}

int _SLang_push_struct (_SLang_Struct_Type *s)
{
   return push_struct_of_type (SLANG_STRUCT_TYPE, s);
}

int _SLang_pop_struct (_SLang_Struct_Type **sp)
{
   SLang_Object_Type obj;
   SLang_Class_Type *cl;
   unsigned char type;

   if (0 != SLang_pop (&obj))
     return -1;

   type = obj.data_type;
   if (type != SLANG_STRUCT_TYPE)
     {
	cl = _SLclass_get_class (type);
	if (cl->cl_struct_def == NULL)
	  {
	     *sp = NULL;
	     SLang_free_object (&obj);
	     SLang_verror (SL_TYPE_MISMATCH,
			   "Expecting struct type object.  Found %s",
			   cl->cl_name);
	     return -1;
	  }
     }

   *sp = obj.v.struct_val;
   return 0;
}

static void struct_destroy (unsigned char type, VOID_STAR vs)
{
   (void) type;
   _SLstruct_delete_struct (*(_SLang_Struct_Type **) vs);
}

static int struct_push (unsigned char type, VOID_STAR ptr)
{
   return push_struct_of_type (type, *(_SLang_Struct_Type **) ptr);
}

static _SLstruct_Field_Type *find_field (_SLang_Struct_Type *s, char *name)
{
   _SLstruct_Field_Type *f, *fmax;

   f = s->fields;
   fmax = f + s->nfields;

   while (f < fmax)
     {
	/* Since both these are slstrings, only compare pointer */
	if (name == f->name)
	  return f;

	f++;
     }

   return NULL;
}

static _SLstruct_Field_Type *pop_field (_SLang_Struct_Type *s, char *name,
					_SLstruct_Field_Type *(*find)(_SLang_Struct_Type *, char *))
{
   _SLstruct_Field_Type *f;

   f = (*find) (s, name);
   if (f == NULL)
     SLang_verror (SL_INVALID_PARM, "struct has no field named %s", name);
   return f;
}

static _SLang_Struct_Type *
  create_struct (unsigned int nfields,
		 char **field_names,
		 unsigned char *field_types,
		 VOID_STAR *field_values)
{
   _SLang_Struct_Type *s;
   _SLstruct_Field_Type *f;
   unsigned int i;

   if (NULL == (s = allocate_struct (nfields)))
     return NULL;

   f = s->fields;
   for (i = 0; i < nfields; i++)
     {
	unsigned char type;
	SLang_Class_Type *cl;
	VOID_STAR value;
	char *name = field_names [i];

	if (name == NULL)
	  {
	     SLang_verror (SL_APPLICATION_ERROR, "A struct field name cannot be NULL");
	     goto return_error;
	  }

	if (-1 == _SLcheck_identifier_syntax (name))
	  goto return_error;

	if (NULL == (f->name = SLang_create_slstring (name)))
	  goto return_error;

	if ((field_values == NULL)
	    || (NULL == (value = field_values [i])))
	  {
	     f++;
	     continue;
	  }

	type = field_types[i];
	cl = _SLclass_get_class (type);

	if ((-1 == (cl->cl_apush (type, value)))
	    || (-1 == SLang_pop (&f->obj)))
	  goto return_error;

	f++;
     }

   return s;

   return_error:
   _SLstruct_delete_struct (s);
   return NULL;
}

int SLstruct_create_struct (unsigned int nfields,
			    char **field_names,
			    unsigned char *field_types,
			    VOID_STAR *field_values)
{
   _SLang_Struct_Type *s;
   
   if (NULL == (s = create_struct (nfields, field_names, field_types, field_values)))
     return -1;

   if (0 == _SLang_push_struct (s))
     return 0;

   _SLstruct_delete_struct (s);
   return -1;
}

/* Interpreter interface */

int _SLstruct_define_struct (void)
{
   int nfields;
   _SLang_Struct_Type *s;
   _SLstruct_Field_Type *f;

   if (-1 == SLang_pop_integer (&nfields))
     return -1;

   if (nfields <= 0)
     {
	SLang_verror (SL_INVALID_PARM, "Number of struct fields must be > 0");
	return -1;
     }

   if (NULL == (s = allocate_struct (nfields)))
     return -1;

   f = s->fields;
   while (nfields)
     {
	char *name;

	nfields--;
	if (-1 == SLang_pop_slstring (&name))
	  {
	     _SLstruct_delete_struct (s);
	     return -1;
	  }
	f[nfields].name = name;
     }

   if (-1 == _SLang_push_struct (s))
     {
	_SLstruct_delete_struct (s);
	return -1;
     }
   return 0;
}

/* Simply make a struct that contains the same fields as struct s.  Do not
 * duplicate the field values.
 */
static _SLang_Struct_Type *make_struct_shell (_SLang_Struct_Type *s)
{
   _SLang_Struct_Type *new_s;
   _SLstruct_Field_Type *new_f, *old_f;
   unsigned int i, nfields;

   nfields = s->nfields;
   if (NULL == (new_s = allocate_struct (nfields)))
     return NULL;

   new_f = new_s->fields;
   old_f = s->fields;

   for (i = 0; i < nfields; i++)
     {
	if (NULL == (new_f[i].name = SLang_create_slstring (old_f[i].name)))
	  {
	     _SLstruct_delete_struct (new_s);
	     return NULL;
	  }
     }
   return new_s;
}

static int struct_init_array_object (unsigned char type, VOID_STAR addr)
{
   SLang_Class_Type *cl;
   _SLang_Struct_Type *s;

   cl = _SLclass_get_class (type);
   if (NULL == (s = make_struct_shell (cl->cl_struct_def)))
     return -1;

   s->num_refs = 1;
   *(_SLang_Struct_Type **) addr = s;
   return 0;
}

static int
typedefed_struct_datatype_deref (unsigned char type)
{
   SLang_Class_Type *cl;
   _SLang_Struct_Type *s;

   cl = _SLclass_get_class (type);
   if (NULL == (s = make_struct_shell (cl->cl_struct_def)))
     return -1;

   if (-1 == push_struct_of_type (type, s))
     {
	_SLstruct_delete_struct (s);
	return -1;
     }

   return 0;
}

static _SLang_Struct_Type *duplicate_struct (_SLang_Struct_Type *s)
{
   _SLang_Struct_Type *new_s;
   _SLstruct_Field_Type *new_f, *f, *fmax;

   new_s = make_struct_shell (s);

   if (new_s == NULL)
     return NULL;

   f = s->fields;
   fmax = f + s->nfields;
   new_f = new_s->fields;

   while (f < fmax)
     {
	SLang_Object_Type *obj;

	obj = &f->obj;
	if (obj->data_type != SLANG_UNDEFINED_TYPE)
	  {
	     if ((-1 == _SLpush_slang_obj (obj))
		 || (-1 == SLang_pop (&new_f->obj)))
	       {
		  _SLstruct_delete_struct (new_s);
		  return NULL;
	       }
	  }
	new_f++;
	f++;
     }

   return new_s;
}

static int struct_dereference (unsigned char type, VOID_STAR addr)
{
   _SLang_Struct_Type *s;

   if (NULL == (s = duplicate_struct (*(_SLang_Struct_Type **) addr)))
     return -1;

   if (-1 == push_struct_of_type (type, s))
     {
	_SLstruct_delete_struct (s);
	return -1;
     }

   return 0;
}

/*{{{ foreach */

struct _SLang_Foreach_Context_Type
{
   _SLang_Struct_Type *s;
   char *next_field_name;
};

static SLang_Foreach_Context_Type *
struct_foreach_open (unsigned char type, unsigned int num)
{
   SLang_Foreach_Context_Type *c;
   _SLang_Struct_Type *s;
   char *next_name;

   (void) type;

   if (-1 == _SLang_pop_struct (&s))
     return NULL;

   switch (num)
     {
      case 0:
	next_name = SLang_create_slstring ("next");
	break;

      case 1:
	if (-1 == SLang_pop_slstring (&next_name))
	  next_name = NULL;
	break;

      default:
	next_name = NULL;
	SLang_verror (SL_NOT_IMPLEMENTED,
		      "'foreach (Struct_Type) using' requires single control value");
	SLdo_pop_n (num);
	break;
     }

   if (next_name == NULL)
     {
	_SLstruct_delete_struct (s);
	return NULL;
     }

   c = (SLang_Foreach_Context_Type *)SLmalloc (sizeof (SLang_Foreach_Context_Type));
   if (c == NULL)
     {
	_SLstruct_delete_struct (s);
	SLang_free_slstring (next_name);
	return NULL;
     }
   memset ((char *) c, 0, sizeof (SLang_Foreach_Context_Type));

   c->next_field_name = next_name;
   c->s = s;

   return c;
}

static void struct_foreach_close (unsigned char type, SLang_Foreach_Context_Type *c)
{
   (void) type;
   if (c == NULL) return;

   SLang_free_slstring (c->next_field_name);
   if (c->s != NULL) _SLstruct_delete_struct (c->s);
   SLfree ((char *) c);
}

static int struct_foreach (unsigned char type, SLang_Foreach_Context_Type *c)
{
   _SLstruct_Field_Type *f;
   _SLang_Struct_Type *next_s;

   (void) type;

   if (c == NULL)
     return -1;

   if (c->s == NULL)
     return 0;			       /* done */

   if (-1 == _SLang_push_struct (c->s))
     return -1;

   /* Now get the next one ready for the next foreach loop */

   next_s = NULL;
   if (NULL != (f = find_field (c->s, c->next_field_name)))
     {
	SLang_Class_Type *cl;

	cl = _SLclass_get_class (f->obj.data_type);
	/* Note that I cannot simply look for SLANG_STRUCT_TYPE since the
	 * user may have typedefed another struct type.  So, look at the
	 * class methods.
	 */
	if (cl->cl_foreach_open == struct_foreach_open)
	  {
	     next_s = f->obj.v.struct_val;
	     next_s->num_refs += 1;
	  }
     }

   _SLstruct_delete_struct (c->s);
   c->s = next_s;

   /* keep going */
   return 1;
}

/*}}}*/

static int struct_sput (unsigned char type, char *name)
{
   _SLang_Struct_Type *s;
   _SLstruct_Field_Type *f;
   SLang_Object_Type obj;

   (void) type;

   if (-1 == _SLang_pop_struct (&s))
     return -1;

   if ((NULL == (f = pop_field (s, name, find_field)))
       || (-1 == SLang_pop (&obj)))
     {
	_SLstruct_delete_struct (s);
	return -1;
     }

   SLang_free_object (&f->obj);
   f->obj = obj;
   _SLstruct_delete_struct (s);
   return 0;
}

static int struct_sget (unsigned char type, char *name)
{
   _SLang_Struct_Type *s;
   _SLstruct_Field_Type *f;
   int ret;

   (void) type;

   if (-1 == _SLang_pop_struct (&s))
     return -1;

   if (NULL == (f = pop_field (s, name, find_field)))
     {
	_SLstruct_delete_struct (s);
	return -1;
     }

   ret = _SLpush_slang_obj (&f->obj);
   _SLstruct_delete_struct (s);
   return ret;
}

static int struct_typecast
  (unsigned char a_type, VOID_STAR ap, unsigned int na,
   unsigned char b_type, VOID_STAR bp)
{
   _SLang_Struct_Type **a, **b;
   unsigned int i;

   (void) a_type;
   (void) b_type;