[deliverable/binutils-gdb.git] / gdb / gnu-v2-abi.c

/* Abstraction of GNU v2 abi.

   Copyright 2001, 2002, 2003 Free Software Foundation, Inc.

   Contributed by Daniel Berlin <dberlin@redhat.com>

   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 "defs.h"
#include "gdb_string.h"
#include "symtab.h"
#include "gdbtypes.h"
#include "value.h"
#include "demangle.h"
#include "cp-abi.h"
#include "cp-support.h"

#include <ctype.h>

struct cp_abi_ops gnu_v2_abi_ops;

static int vb_match (struct type *, int, struct type *);
int gnuv2_baseclass_offset (struct type *type, int index, char *valaddr,
			    CORE_ADDR address);

static enum dtor_kinds
gnuv2_is_destructor_name (const char *name)
{
  if ((name[0] == '_' && is_cplus_marker (name[1]) && name[2] == '_')
      || strncmp (name, "__dt__", 6) == 0)
    return complete_object_dtor;
  else
    return 0;
}

static enum ctor_kinds
gnuv2_is_constructor_name (const char *name)
{
  if ((name[0] == '_' && name[1] == '_'
       && (isdigit (name[2]) || strchr ("Qt", name[2])))
      || strncmp (name, "__ct__", 6) == 0)
    return complete_object_ctor;
  else
    return 0;
}

static int
gnuv2_is_vtable_name (const char *name)
{
  return (((name)[0] == '_'
	   && (((name)[1] == 'V' && (name)[2] == 'T')
	       || ((name)[1] == 'v' && (name)[2] == 't'))
	   && is_cplus_marker ((name)[3])) ||
	  ((name)[0] == '_' && (name)[1] == '_'
	   && (name)[2] == 'v' && (name)[3] == 't' && (name)[4] == '_'));
}

static int
gnuv2_is_operator_name (const char *name)
{
  return strncmp (name, "operator", 8) == 0;
}

\f
/* Return a virtual function as a value.
   ARG1 is the object which provides the virtual function
   table pointer.  *ARG1P is side-effected in calling this function.
   F is the list of member functions which contains the desired virtual
   function.
   J is an index into F which provides the desired virtual function.

   TYPE is the type in which F is located.  */
static struct value *
gnuv2_virtual_fn_field (struct value **arg1p, struct fn_field * f, int j,
			struct type * type, int offset)
{
  struct value *arg1 = *arg1p;
  struct type *type1 = check_typedef (VALUE_TYPE (arg1));


  struct type *entry_type;
  /* First, get the virtual function table pointer.  That comes
     with a strange type, so cast it to type `pointer to long' (which
     should serve just fine as a function type).  Then, index into
     the table, and convert final value to appropriate function type.  */
  struct value *entry;
  struct value *vfn;
  struct value *vtbl;
  struct value *vi = value_from_longest (builtin_type_int,
				     (LONGEST) TYPE_FN_FIELD_VOFFSET (f, j));
  struct type *fcontext = TYPE_FN_FIELD_FCONTEXT (f, j);
  struct type *context;
  if (fcontext == NULL)
    /* We don't have an fcontext (e.g. the program was compiled with
       g++ version 1).  Try to get the vtbl from the TYPE_VPTR_BASETYPE.
       This won't work right for multiple inheritance, but at least we
       should do as well as GDB 3.x did.  */
    fcontext = TYPE_VPTR_BASETYPE (type);
  context = lookup_pointer_type (fcontext);
  /* Now context is a pointer to the basetype containing the vtbl.  */
  if (TYPE_TARGET_TYPE (context) != type1)
    {
      struct value *tmp = value_cast (context, value_addr (arg1));
      arg1 = value_ind (tmp);
      type1 = check_typedef (VALUE_TYPE (arg1));
    }

  context = type1;
  /* Now context is the basetype containing the vtbl.  */

  /* This type may have been defined before its virtual function table
     was.  If so, fill in the virtual function table entry for the
     type now.  */
  if (TYPE_VPTR_FIELDNO (context) < 0)
    fill_in_vptr_fieldno (context);

  /* The virtual function table is now an array of structures
     which have the form { int16 offset, delta; void *pfn; }.  */
  vtbl = value_primitive_field (arg1, 0, TYPE_VPTR_FIELDNO (context),
				TYPE_VPTR_BASETYPE (context));

  /* With older versions of g++, the vtbl field pointed to an array
     of structures.  Nowadays it points directly to the structure. */
  if (TYPE_CODE (VALUE_TYPE (vtbl)) == TYPE_CODE_PTR
      && TYPE_CODE (TYPE_TARGET_TYPE (VALUE_TYPE (vtbl))) == TYPE_CODE_ARRAY)
    {
      /* Handle the case where the vtbl field points to an
         array of structures. */
      vtbl = value_ind (vtbl);

      /* Index into the virtual function table.  This is hard-coded because
         looking up a field is not cheap, and it may be important to save
         time, e.g. if the user has set a conditional breakpoint calling
         a virtual function.  */
      entry = value_subscript (vtbl, vi);
    }
  else
    {
      /* Handle the case where the vtbl field points directly to a structure. */
      vtbl = value_add (vtbl, vi);
      entry = value_ind (vtbl);
    }

  entry_type = check_typedef (VALUE_TYPE (entry));

  if (TYPE_CODE (entry_type) == TYPE_CODE_STRUCT)
    {
      /* Move the `this' pointer according to the virtual function table. */
      VALUE_OFFSET (arg1) += value_as_long (value_field (entry, 0));

      if (!VALUE_LAZY (arg1))
	{
	  VALUE_LAZY (arg1) = 1;
	  value_fetch_lazy (arg1);
	}

      vfn = value_field (entry, 2);
    }
  else if (TYPE_CODE (entry_type) == TYPE_CODE_PTR)
    vfn = entry;
  else
    error ("I'm confused:  virtual function table has bad type");
  /* Reinstantiate the function pointer with the correct type.  */
  VALUE_TYPE (vfn) = lookup_pointer_type (TYPE_FN_FIELD_TYPE (f, j));

  *arg1p = arg1;
  return vfn;
}


static struct type *
gnuv2_value_rtti_type (struct value *v, int *full, int *top, int *using_enc)
{
  struct type *known_type;
  struct type *rtti_type;
  CORE_ADDR coreptr;
  struct value *vp;
  long top_offset = 0;
  char rtti_type_name[256];
  CORE_ADDR vtbl;
  struct minimal_symbol *minsym;
  struct symbol *sym;
  char *demangled_name;
  struct type *btype;

  if (full)
    *full = 0;
  if (top)
    *top = -1;
  if (using_enc)
    *using_enc = 0;

  /* Get declared type */
  known_type = VALUE_TYPE (v);
  CHECK_TYPEDEF (known_type);
  /* RTTI works only or class objects */
  if (TYPE_CODE (known_type) != TYPE_CODE_CLASS)
    return NULL;

  /* Plan on this changing in the future as i get around to setting
     the vtables properly for G++ compiled stuff.  Also, I'll be using
     the type info functions, which are always right.  Deal with it
     until then.  */

  /* If the type has no vptr fieldno, try to get it filled in */
  if (TYPE_VPTR_FIELDNO(known_type) < 0)
    fill_in_vptr_fieldno(known_type);

  /* If we still can't find one, give up */
  if (TYPE_VPTR_FIELDNO(known_type) < 0)
    return NULL;

  /* Make sure our basetype and known type match, otherwise, cast
     so we can get at the vtable properly.
  */
  btype = TYPE_VPTR_BASETYPE (known_type);
  CHECK_TYPEDEF (btype);
  if (btype != known_type )
    {
      v = value_cast (btype, v);
      if (using_enc)
        *using_enc=1;
    }
  /*
    We can't use value_ind here, because it would want to use RTTI, and
    we'd waste a bunch of time figuring out we already know the type.
    Besides, we don't care about the type, just the actual pointer
  */
  if (VALUE_ADDRESS (value_field (v, TYPE_VPTR_FIELDNO (known_type))) == 0)
    return NULL;

  vtbl=value_as_address(value_field(v,TYPE_VPTR_FIELDNO(known_type)));

  /* Try to find a symbol that is the vtable */
  minsym=lookup_minimal_symbol_by_pc(vtbl);
  if (minsym==NULL
      || (demangled_name=DEPRECATED_SYMBOL_NAME (minsym))==NULL
      || !is_vtable_name (demangled_name))
    return NULL;

  /* If we just skip the prefix, we get screwed by namespaces */
  demangled_name=cplus_demangle(demangled_name,DMGL_PARAMS|DMGL_ANSI);
  *(strchr(demangled_name,' '))=0;

  /* Lookup the type for the name */
  /* FIXME: chastain/2003-11-26: block=NULL is bogus.  See pr gdb/1465. */
  rtti_type = cp_lookup_rtti_type (demangled_name, NULL);
  if (rtti_type == NULL)
    return NULL;

  if (TYPE_N_BASECLASSES(rtti_type) > 1 &&  full && (*full) != 1)
    {
      if (top)
        *top=TYPE_BASECLASS_BITPOS(rtti_type,TYPE_VPTR_FIELDNO(rtti_type))/8;
      if (top && ((*top) >0))
        {
          if (TYPE_LENGTH(rtti_type) > TYPE_LENGTH(known_type))
            {
              if (full)
                *full=0;
            }
          else
            {
              if (full)
                *full=1;
            }
        }
    }
  else
    {
      if (full)
        *full=1;
    }

  return rtti_type;
}

/* Return true if the INDEXth field of TYPE is a virtual baseclass
   pointer which is for the base class whose type is BASECLASS.  */

static int
vb_match (struct type *type, int index, struct type *basetype)
{
  struct type *fieldtype;
  char *name = TYPE_FIELD_NAME (type, index);
  char *field_class_name = NULL;

  if (*name != '_')
    return 0;
  /* gcc 2.4 uses _vb$.  */
  if (name[1] == 'v' && name[2] == 'b' && is_cplus_marker (name[3]))
    field_class_name = name + 4;
  /* gcc 2.5 will use __vb_.  */
  if (name[1] == '_' && name[2] == 'v' && name[3] == 'b' && name[4] == '_')
    field_class_name = name + 5;

  if (field_class_name == NULL)
    /* This field is not a virtual base class pointer.  */
    return 0;

  /* It's a virtual baseclass pointer, now we just need to find out whether
     it is for this baseclass.  */
  fieldtype = TYPE_FIELD_TYPE (type, index);
  if (fieldtype == NULL
      || TYPE_CODE (fieldtype) != TYPE_CODE_PTR)
    /* "Can't happen".  */
    return 0;

  /* What we check for is that either the types are equal (needed for
     nameless types) or have the same name.  This is ugly, and a more
     elegant solution should be devised (which would probably just push
     the ugliness into symbol reading unless we change the stabs format).  */
  if (TYPE_TARGET_TYPE (fieldtype) == basetype)
    return 1;

  if (TYPE_NAME (basetype) != NULL
      && TYPE_NAME (TYPE_TARGET_TYPE (fieldtype)) != NULL
      && strcmp (TYPE_NAME (basetype),
		 TYPE_NAME (TYPE_TARGET_TYPE (fieldtype))) == 0)
    return 1;
  return 0;
}

/* Compute the offset of the baseclass which is
   the INDEXth baseclass of class TYPE,
   for value at VALADDR (in host) at ADDRESS (in target).
   The result is the offset of the baseclass value relative
   to (the address of)(ARG) + OFFSET.

   -1 is returned on error. */

int
gnuv2_baseclass_offset (struct type *type, int index, char *valaddr,
		  CORE_ADDR address)
{
  struct type *basetype = TYPE_BASECLASS (type, index);

  if (BASETYPE_VIA_VIRTUAL (type, index))
    {
      /* Must hunt for the pointer to this virtual baseclass.  */
      int i, len = TYPE_NFIELDS (type);
      int n_baseclasses = TYPE_N_BASECLASSES (type);

      /* First look for the virtual baseclass pointer
         in the fields.  */
      for (i = n_baseclasses; i < len; i++)
	{
	  if (vb_match (type, i, basetype))
	    {
	      CORE_ADDR addr
	      = unpack_pointer (TYPE_FIELD_TYPE (type, i),
				valaddr + (TYPE_FIELD_BITPOS (type, i) / 8));

	      return addr - (LONGEST) address;
	    }
	}
      /* Not in the fields, so try looking through the baseclasses.  */
      for (i = index + 1; i < n_baseclasses; i++)
	{
	  int boffset =
	  baseclass_offset (type, i, valaddr, address);
	  if (boffset)
	    return boffset;
	}
      /* Not found.  */
      return -1;
    }

  /* Baseclass is easily computed.  */
  return TYPE_BASECLASS_BITPOS (type, index) / 8;
}

static void
init_gnuv2_ops (void)
{
  gnu_v2_abi_ops.shortname = "gnu-v2";
  gnu_v2_abi_ops.longname = "GNU G++ Version 2 ABI";
  gnu_v2_abi_ops.doc = "G++ Version 2 ABI";
  gnu_v2_abi_ops.is_destructor_name = gnuv2_is_destructor_name;
  gnu_v2_abi_ops.is_constructor_name = gnuv2_is_constructor_name;
  gnu_v2_abi_ops.is_vtable_name = gnuv2_is_vtable_name;
  gnu_v2_abi_ops.is_operator_name = gnuv2_is_operator_name;
  gnu_v2_abi_ops.virtual_fn_field = gnuv2_virtual_fn_field;
  gnu_v2_abi_ops.rtti_type = gnuv2_value_rtti_type;
  gnu_v2_abi_ops.baseclass_offset = gnuv2_baseclass_offset;
}

extern initialize_file_ftype _initialize_gnu_v2_abi; /* -Wmissing-prototypes */

void
_initialize_gnu_v2_abi (void)
{
  init_gnuv2_ops ();
  register_cp_abi (&gnu_v2_abi_ops);
  set_cp_abi_as_auto_default (gnu_v2_abi_ops.shortname);
}
Commit	Line	Data
015a42b4	1	/* Abstraction of GNU v2 abi.
1bac305b	2
362ff856	3	Copyright 2001, 2002, 2003 Free Software Foundation, Inc.
1bac305b	4
015a42b4	5	Contributed by Daniel Berlin <dberlin@redhat.com>
015a42b4 JB	6
	7	This file is part of GDB.
	8
	9	This program is free software; you can redistribute it and/or
	10	modify
	11	it under the terms of the GNU General Public License as published
	12	by
	13	the Free Software Foundation; either version 2 of the License, or
	14	(at your option) any later version.
	15
	16	This program is distributed in the hope that it will be useful,
	17	but WITHOUT ANY WARRANTY; without even the implied warranty of
	18	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	19	GNU General Public License for more details.
	20
	21	You should have received a copy of the GNU General Public License
	22	along with this program; if not, write to the Free Software
	23	Foundation, Inc., 59 Temple Place - Suite 330,
	24	Boston, MA 02111-1307, USA. */
	25
	26	#include "defs.h"
015a42b4 JB	27	#include "gdb_string.h"
	28	#include "symtab.h"
	29	#include "gdbtypes.h"
	30	#include "value.h"
	31	#include "demangle.h"
	32	#include "cp-abi.h"
362ff856	33	#include "cp-support.h"
015a42b4 JB	34
	35	#include <ctype.h>
	36
	37	struct cp_abi_ops gnu_v2_abi_ops;
	38
	39	static int vb_match (struct type , int, struct type );
1514d34e DJ	40	int gnuv2_baseclass_offset (struct type type, int index, char valaddr,
1514d34e DJ	41	CORE_ADDR address);
015a42b4 JB	42
	43	static enum dtor_kinds
	44	gnuv2_is_destructor_name (const char *name)
	45	{
	46	if ((name[0] == '_' && is_cplus_marker (name[1]) && name[2] == '_')
	47	\|\| strncmp (name, "__dt__", 6) == 0)
	48	return complete_object_dtor;
	49	else
	50	return 0;
	51	}
	52
	53	static enum ctor_kinds
	54	gnuv2_is_constructor_name (const char *name)
	55	{
	56	if ((name[0] == '_' && name[1] == '_'
	57	&& (isdigit (name[2]) \|\| strchr ("Qt", name[2])))
	58	\|\| strncmp (name, "__ct__", 6) == 0)
	59	return complete_object_ctor;
	60	else
	61	return 0;
	62	}
	63
	64	static int
	65	gnuv2_is_vtable_name (const char *name)
	66	{
	67	return (((name)[0] == '_'
	68	&& (((name)[1] == 'V' && (name)[2] == 'T')
	69	\|\| ((name)[1] == 'v' && (name)[2] == 't'))
	70	&& is_cplus_marker ((name)[3])) \|\|
	71	((name)[0] == '_' && (name)[1] == '_'
	72	&& (name)[2] == 'v' && (name)[3] == 't' && (name)[4] == '_'));
	73	}
	74
	75	static int
	76	gnuv2_is_operator_name (const char *name)
	77	{
	78	return strncmp (name, "operator", 8) == 0;
	79	}
	80
	81	\f
	82	/* Return a virtual function as a value.
	83	ARG1 is the object which provides the virtual function
	84	table pointer. *ARG1P is side-effected in calling this function.
	85	F is the list of member functions which contains the desired virtual
	86	function.
	87	J is an index into F which provides the desired virtual function.
	88
	89	TYPE is the type in which F is located. */
e933e538 AC	90	static struct value *
e933e538 AC	91	gnuv2_virtual_fn_field (struct value *arg1p, struct fn_field f, int j,
015a42b4 JB	92	struct type * type, int offset)
015a42b4 JB	93	{
e933e538	94	struct value arg1 = arg1p;
015a42b4 JB	95	struct type *type1 = check_typedef (VALUE_TYPE (arg1));
	96
	97
	98	struct type *entry_type;
	99	/* First, get the virtual function table pointer. That comes
	100	with a strange type, so cast it to type `pointer to long' (which
	101	should serve just fine as a function type). Then, index into
	102	the table, and convert final value to appropriate function type. */
e933e538 AC	103	struct value *entry;
	104	struct value *vfn;
	105	struct value *vtbl;
	106	struct value *vi = value_from_longest (builtin_type_int,
015a42b4 JB	107	(LONGEST) TYPE_FN_FIELD_VOFFSET (f, j));
	108	struct type *fcontext = TYPE_FN_FIELD_FCONTEXT (f, j);
	109	struct type *context;
	110	if (fcontext == NULL)
	111	/* We don't have an fcontext (e.g. the program was compiled with
	112	g++ version 1). Try to get the vtbl from the TYPE_VPTR_BASETYPE.
	113	This won't work right for multiple inheritance, but at least we
	114	should do as well as GDB 3.x did. */
	115	fcontext = TYPE_VPTR_BASETYPE (type);
	116	context = lookup_pointer_type (fcontext);
	117	/* Now context is a pointer to the basetype containing the vtbl. */
	118	if (TYPE_TARGET_TYPE (context) != type1)
	119	{
e933e538	120	struct value *tmp = value_cast (context, value_addr (arg1));
015a42b4 JB	121	arg1 = value_ind (tmp);
	122	type1 = check_typedef (VALUE_TYPE (arg1));
	123	}
	124
	125	context = type1;
	126	/* Now context is the basetype containing the vtbl. */
	127
	128	/* This type may have been defined before its virtual function table
	129	was. If so, fill in the virtual function table entry for the
	130	type now. */
	131	if (TYPE_VPTR_FIELDNO (context) < 0)
	132	fill_in_vptr_fieldno (context);
	133
	134	/* The virtual function table is now an array of structures
	135	which have the form { int16 offset, delta; void pfn; }. /
	136	vtbl = value_primitive_field (arg1, 0, TYPE_VPTR_FIELDNO (context),
	137	TYPE_VPTR_BASETYPE (context));
	138
	139	/* With older versions of g++, the vtbl field pointed to an array
	140	of structures. Nowadays it points directly to the structure. */
	141	if (TYPE_CODE (VALUE_TYPE (vtbl)) == TYPE_CODE_PTR
	142	&& TYPE_CODE (TYPE_TARGET_TYPE (VALUE_TYPE (vtbl))) == TYPE_CODE_ARRAY)
	143	{
	144	/* Handle the case where the vtbl field points to an
	145	array of structures. */
	146	vtbl = value_ind (vtbl);
	147
	148	/* Index into the virtual function table. This is hard-coded because
	149	looking up a field is not cheap, and it may be important to save
	150	time, e.g. if the user has set a conditional breakpoint calling
	151	a virtual function. */
	152	entry = value_subscript (vtbl, vi);
	153	}
	154	else
	155	{
	156	/* Handle the case where the vtbl field points directly to a structure. */
	157	vtbl = value_add (vtbl, vi);
	158	entry = value_ind (vtbl);
	159	}
	160
	161	entry_type = check_typedef (VALUE_TYPE (entry));
	162
	163	if (TYPE_CODE (entry_type) == TYPE_CODE_STRUCT)
	164	{
	165	/* Move the `this' pointer according to the virtual function table. */
	166	VALUE_OFFSET (arg1) += value_as_long (value_field (entry, 0));
	167
	168	if (!VALUE_LAZY (arg1))
	169	{
	170	VALUE_LAZY (arg1) = 1;
	171	value_fetch_lazy (arg1);
	172	}
	173
	174	vfn = value_field (entry, 2);
	175	}
	176	else if (TYPE_CODE (entry_type) == TYPE_CODE_PTR)
	177	vfn = entry;
	178	else
	179	error ("I'm confused: virtual function table has bad type");
	180	/* Reinstantiate the function pointer with the correct type. */
	181	VALUE_TYPE (vfn) = lookup_pointer_type (TYPE_FN_FIELD_TYPE (f, j));
	182
	183	*arg1p = arg1;
	184	return vfn;
185	}
186
187
b9362cc7	188	static struct type *
e933e538	189	gnuv2_value_rtti_type (struct value v, int full, int top, int using_enc)
015a42b4 JB	190	{
	191	struct type *known_type;
	192	struct type *rtti_type;
	193	CORE_ADDR coreptr;
e933e538	194	struct value *vp;
015a42b4 JB	195	long top_offset = 0;
	196	char rtti_type_name[256];
	197	CORE_ADDR vtbl;
	198	struct minimal_symbol *minsym;
	199	struct symbol *sym;
	200	char *demangled_name;
	201	struct type *btype;
	202
	203	if (full)
	204	*full = 0;
	205	if (top)
	206	*top = -1;
	207	if (using_enc)
	208	*using_enc = 0;
	209
	210	/* Get declared type */
	211	known_type = VALUE_TYPE (v);
	212	CHECK_TYPEDEF (known_type);
	213	/* RTTI works only or class objects */
	214	if (TYPE_CODE (known_type) != TYPE_CODE_CLASS)
	215	return NULL;
	216
	217	/* Plan on this changing in the future as i get around to setting
	218	the vtables properly for G++ compiled stuff. Also, I'll be using
	219	the type info functions, which are always right. Deal with it
	220	until then. */
	221
	222	/* If the type has no vptr fieldno, try to get it filled in */
	223	if (TYPE_VPTR_FIELDNO(known_type) < 0)
	224	fill_in_vptr_fieldno(known_type);
	225
	226	/* If we still can't find one, give up */
	227	if (TYPE_VPTR_FIELDNO(known_type) < 0)
	228	return NULL;
	229
	230	/* Make sure our basetype and known type match, otherwise, cast
	231	so we can get at the vtable properly.
	232	*/
	233	btype = TYPE_VPTR_BASETYPE (known_type);
	234	CHECK_TYPEDEF (btype);
	235	if (btype != known_type )
	236	{
	237	v = value_cast (btype, v);
	238	if (using_enc)
	239	*using_enc=1;
	240	}
	241	/*
	242	We can't use value_ind here, because it would want to use RTTI, and
	243	we'd waste a bunch of time figuring out we already know the type.
	244	Besides, we don't care about the type, just the actual pointer
	245	*/
	246	if (VALUE_ADDRESS (value_field (v, TYPE_VPTR_FIELDNO (known_type))) == 0)
	247	return NULL;
	248
2a73a662	249	vtbl=value_as_address(value_field(v,TYPE_VPTR_FIELDNO(known_type)));
015a42b4 JB	250
	251	/* Try to find a symbol that is the vtable */
	252	minsym=lookup_minimal_symbol_by_pc(vtbl);
	253	if (minsym==NULL
22abf04a	254	\|\| (demangled_name=DEPRECATED_SYMBOL_NAME (minsym))==NULL
015a42b4 JB	255	\|\| !is_vtable_name (demangled_name))
	256	return NULL;
	257
	258	/* If we just skip the prefix, we get screwed by namespaces */
	259	demangled_name=cplus_demangle(demangled_name,DMGL_PARAMS\|DMGL_ANSI);
	260	*(strchr(demangled_name,' '))=0;
	261
	262	/* Lookup the type for the name */
362ff856 MC	263	/* FIXME: chastain/2003-11-26: block=NULL is bogus. See pr gdb/1465. */
	264	rtti_type = cp_lookup_rtti_type (demangled_name, NULL);
	265	if (rtti_type == NULL)
015a42b4 JB	266	return NULL;
	267
	268	if (TYPE_N_BASECLASSES(rtti_type) > 1 && full && (*full) != 1)
	269	{
	270	if (top)
	271	*top=TYPE_BASECLASS_BITPOS(rtti_type,TYPE_VPTR_FIELDNO(rtti_type))/8;
	272	if (top && ((*top) >0))
	273	{
	274	if (TYPE_LENGTH(rtti_type) > TYPE_LENGTH(known_type))
	275	{
	276	if (full)
	277	*full=0;
	278	}
	279	else
	280	{
	281	if (full)
	282	*full=1;
	283	}
	284	}
	285	}
	286	else
	287	{
	288	if (full)
	289	*full=1;
	290	}
015a42b4 JB	291
	292	return rtti_type;
	293	}
	294
1514d34e DJ	295	/* Return true if the INDEXth field of TYPE is a virtual baseclass
	296	pointer which is for the base class whose type is BASECLASS. */
	297
	298	static int
	299	vb_match (struct type type, int index, struct type basetype)
	300	{
	301	struct type *fieldtype;
	302	char *name = TYPE_FIELD_NAME (type, index);
	303	char *field_class_name = NULL;
	304
	305	if (*name != '_')
	306	return 0;
	307	/* gcc 2.4 uses _vb$. */
	308	if (name[1] == 'v' && name[2] == 'b' && is_cplus_marker (name[3]))
	309	field_class_name = name + 4;
	310	/* gcc 2.5 will use __vb_. */
	311	if (name[1] == '_' && name[2] == 'v' && name[3] == 'b' && name[4] == '_')
	312	field_class_name = name + 5;
	313
	314	if (field_class_name == NULL)
	315	/* This field is not a virtual base class pointer. */
	316	return 0;
	317
	318	/* It's a virtual baseclass pointer, now we just need to find out whether
	319	it is for this baseclass. */
	320	fieldtype = TYPE_FIELD_TYPE (type, index);
	321	if (fieldtype == NULL
	322	\|\| TYPE_CODE (fieldtype) != TYPE_CODE_PTR)
	323	/* "Can't happen". */
	324	return 0;
	325
	326	/* What we check for is that either the types are equal (needed for
	327	nameless types) or have the same name. This is ugly, and a more
	328	elegant solution should be devised (which would probably just push
	329	the ugliness into symbol reading unless we change the stabs format). */
	330	if (TYPE_TARGET_TYPE (fieldtype) == basetype)
	331	return 1;
	332
	333	if (TYPE_NAME (basetype) != NULL
	334	&& TYPE_NAME (TYPE_TARGET_TYPE (fieldtype)) != NULL
bde58177 AC	335	&& strcmp (TYPE_NAME (basetype),
bde58177 AC	336	TYPE_NAME (TYPE_TARGET_TYPE (fieldtype))) == 0)
1514d34e DJ	337	return 1;
	338	return 0;
	339	}
	340
	341	/* Compute the offset of the baseclass which is
	342	the INDEXth baseclass of class TYPE,
	343	for value at VALADDR (in host) at ADDRESS (in target).
	344	The result is the offset of the baseclass value relative
	345	to (the address of)(ARG) + OFFSET.
	346
	347	-1 is returned on error. */
	348
	349	int
	350	gnuv2_baseclass_offset (struct type type, int index, char valaddr,
	351	CORE_ADDR address)
	352	{
	353	struct type *basetype = TYPE_BASECLASS (type, index);
	354
	355	if (BASETYPE_VIA_VIRTUAL (type, index))
	356	{
	357	/* Must hunt for the pointer to this virtual baseclass. */
aa1ee363 AC	358	int i, len = TYPE_NFIELDS (type);
aa1ee363 AC	359	int n_baseclasses = TYPE_N_BASECLASSES (type);
1514d34e DJ	360
	361	/* First look for the virtual baseclass pointer
	362	in the fields. */
	363	for (i = n_baseclasses; i < len; i++)
	364	{
	365	if (vb_match (type, i, basetype))
	366	{
	367	CORE_ADDR addr
	368	= unpack_pointer (TYPE_FIELD_TYPE (type, i),
	369	valaddr + (TYPE_FIELD_BITPOS (type, i) / 8));
	370
	371	return addr - (LONGEST) address;
	372	}
	373	}
	374	/* Not in the fields, so try looking through the baseclasses. */
	375	for (i = index + 1; i < n_baseclasses; i++)
	376	{
	377	int boffset =
	378	baseclass_offset (type, i, valaddr, address);
	379	if (boffset)
	380	return boffset;
	381	}
	382	/* Not found. */
	383	return -1;
	384	}
	385
	386	/* Baseclass is easily computed. */
	387	return TYPE_BASECLASS_BITPOS (type, index) / 8;
	388	}
015a42b4 JB	389
	390	static void
	391	init_gnuv2_ops (void)
	392	{
	393	gnu_v2_abi_ops.shortname = "gnu-v2";
	394	gnu_v2_abi_ops.longname = "GNU G++ Version 2 ABI";
	395	gnu_v2_abi_ops.doc = "G++ Version 2 ABI";
	396	gnu_v2_abi_ops.is_destructor_name = gnuv2_is_destructor_name;
	397	gnu_v2_abi_ops.is_constructor_name = gnuv2_is_constructor_name;
	398	gnu_v2_abi_ops.is_vtable_name = gnuv2_is_vtable_name;
	399	gnu_v2_abi_ops.is_operator_name = gnuv2_is_operator_name;
	400	gnu_v2_abi_ops.virtual_fn_field = gnuv2_virtual_fn_field;
	401	gnu_v2_abi_ops.rtti_type = gnuv2_value_rtti_type;
1514d34e	402	gnu_v2_abi_ops.baseclass_offset = gnuv2_baseclass_offset;
015a42b4 JB	403	}
015a42b4 JB	404
b9362cc7 AC	405	extern initialize_file_ftype _initialize_gnu_v2_abi; /* -Wmissing-prototypes */
b9362cc7 AC	406
015a42b4 JB	407	void
	408	_initialize_gnu_v2_abi (void)
	409	{
	410	init_gnuv2_ops ();
fe1f4a5e DJ	411	register_cp_abi (&gnu_v2_abi_ops);
fe1f4a5e DJ	412	set_cp_abi_as_auto_default (gnu_v2_abi_ops.shortname);
015a42b4	413	}