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

/* Abstraction of GNU v2 abi.

   Copyright (C) 2001, 2002, 2003, 2005, 2007, 2008
   Free Software Foundation, Inc.

   Contributed by Daniel Berlin <[email protected]>

   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 "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 "gnu-v2-abi.h"

#include <ctype.h>

struct cp_abi_ops gnu_v2_abi_ops;

static int vb_match (struct type *, int, struct type *);

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;
  struct type *context_vptr_basetype;
  int context_vptr_fieldno;

  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.  */
  context_vptr_fieldno = get_vptr_fieldno (context, &context_vptr_basetype);
  /* FIXME: What to do if vptr_fieldno is still -1?  */

  /* 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, context_vptr_fieldno,
				context_vptr_basetype);

  /* 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. */
      set_value_offset (arg1, value_offset (arg1) + value_as_long (value_field (entry, 0)));

      if (!value_lazy (arg1))
	{
	  set_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.  */
  deprecated_set_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, *p;
  struct type *btype;
  struct type *known_type_vptr_basetype;
  int known_type_vptr_fieldno;

  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.  */

  /* Try to get the vptr basetype, fieldno.  */
  known_type_vptr_fieldno = get_vptr_fieldno (known_type,
					      &known_type_vptr_basetype);

  /* If we can't find it, give up.  */
  if (known_type_vptr_fieldno < 0)
    return NULL;

  /* Make sure our basetype and known type match, otherwise, cast
     so we can get at the vtable properly.
  */
  btype = known_type_vptr_basetype;
  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, known_type_vptr_fieldno)) == 0)
    return NULL;

  vtbl = value_as_address (value_field (v, known_type_vptr_fieldno));

  /* 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);
  p = strchr (demangled_name, ' ');
  if (p)
    *p = '\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,
			const bfd_byte *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
9b254dd1 DJ	3	Copyright (C) 2001, 2002, 2003, 2005, 2007, 2008
9b254dd1 DJ	4	Free Software Foundation, Inc.
1bac305b	5
015a42b4	6	Contributed by Daniel Berlin <[email protected]>
015a42b4 JB	7
	8	This file is part of GDB.
	9
a9762ec7 JB	10	This program is free software; you can redistribute it and/or modify
	11	it under the terms of the GNU General Public License as published by
	12	the Free Software Foundation; either version 3 of the License, or
015a42b4 JB	13	(at your option) any later version.
	14
	15	This program is distributed in the hope that it will be useful,
	16	but WITHOUT ANY WARRANTY; without even the implied warranty of
	17	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	18	GNU General Public License for more details.
	19
	20	You should have received a copy of the GNU General Public License
a9762ec7	21	along with this program. If not, see <http://www.gnu.org/licenses/>. */
015a42b4 JB	22
015a42b4 JB	23	#include "defs.h"
015a42b4 JB	24	#include "gdb_string.h"
	25	#include "symtab.h"
	26	#include "gdbtypes.h"
	27	#include "value.h"
	28	#include "demangle.h"
	29	#include "cp-abi.h"
362ff856	30	#include "cp-support.h"
6b08edad	31	#include "gnu-v2-abi.h"
015a42b4 JB	32
	33	#include <ctype.h>
	34
	35	struct cp_abi_ops gnu_v2_abi_ops;
	36
	37	static int vb_match (struct type , int, struct type );
	38
	39	static enum dtor_kinds
	40	gnuv2_is_destructor_name (const char *name)
	41	{
	42	if ((name[0] == '_' && is_cplus_marker (name[1]) && name[2] == '_')
	43	\|\| strncmp (name, "__dt__", 6) == 0)
	44	return complete_object_dtor;
	45	else
	46	return 0;
	47	}
	48
	49	static enum ctor_kinds
	50	gnuv2_is_constructor_name (const char *name)
	51	{
	52	if ((name[0] == '_' && name[1] == '_'
	53	&& (isdigit (name[2]) \|\| strchr ("Qt", name[2])))
	54	\|\| strncmp (name, "__ct__", 6) == 0)
	55	return complete_object_ctor;
	56	else
	57	return 0;
	58	}
	59
	60	static int
	61	gnuv2_is_vtable_name (const char *name)
	62	{
	63	return (((name)[0] == '_'
	64	&& (((name)[1] == 'V' && (name)[2] == 'T')
	65	\|\| ((name)[1] == 'v' && (name)[2] == 't'))
	66	&& is_cplus_marker ((name)[3])) \|\|
	67	((name)[0] == '_' && (name)[1] == '_'
	68	&& (name)[2] == 'v' && (name)[3] == 't' && (name)[4] == '_'));
	69	}
	70
	71	static int
	72	gnuv2_is_operator_name (const char *name)
	73	{
	74	return strncmp (name, "operator", 8) == 0;
	75	}
	76
	77	\f
	78	/* Return a virtual function as a value.
	79	ARG1 is the object which provides the virtual function
	80	table pointer. *ARG1P is side-effected in calling this function.
	81	F is the list of member functions which contains the desired virtual
	82	function.
	83	J is an index into F which provides the desired virtual function.
	84
	85	TYPE is the type in which F is located. */
e933e538 AC	86	static struct value *
e933e538 AC	87	gnuv2_virtual_fn_field (struct value *arg1p, struct fn_field f, int j,
015a42b4 JB	88	struct type * type, int offset)
015a42b4 JB	89	{
e933e538	90	struct value arg1 = arg1p;
df407dfe	91	struct type *type1 = check_typedef (value_type (arg1));
015a42b4 JB	92	struct type *entry_type;
	93	/* First, get the virtual function table pointer. That comes
	94	with a strange type, so cast it to type `pointer to long' (which
	95	should serve just fine as a function type). Then, index into
	96	the table, and convert final value to appropriate function type. */
e933e538 AC	97	struct value *entry;
	98	struct value *vfn;
	99	struct value *vtbl;
	100	struct value *vi = value_from_longest (builtin_type_int,
015a42b4 JB	101	(LONGEST) TYPE_FN_FIELD_VOFFSET (f, j));
	102	struct type *fcontext = TYPE_FN_FIELD_FCONTEXT (f, j);
	103	struct type *context;
81fe8080 DE	104	struct type *context_vptr_basetype;
	105	int context_vptr_fieldno;
	106
015a42b4 JB	107	if (fcontext == NULL)
	108	/* We don't have an fcontext (e.g. the program was compiled with
	109	g++ version 1). Try to get the vtbl from the TYPE_VPTR_BASETYPE.
	110	This won't work right for multiple inheritance, but at least we
	111	should do as well as GDB 3.x did. */
	112	fcontext = TYPE_VPTR_BASETYPE (type);
	113	context = lookup_pointer_type (fcontext);
	114	/* Now context is a pointer to the basetype containing the vtbl. */
	115	if (TYPE_TARGET_TYPE (context) != type1)
	116	{
e933e538	117	struct value *tmp = value_cast (context, value_addr (arg1));
015a42b4	118	arg1 = value_ind (tmp);
df407dfe	119	type1 = check_typedef (value_type (arg1));
015a42b4 JB	120	}
	121
	122	context = type1;
	123	/* Now context is the basetype containing the vtbl. */
	124
	125	/* This type may have been defined before its virtual function table
	126	was. If so, fill in the virtual function table entry for the
	127	type now. */
81fe8080 DE	128	context_vptr_fieldno = get_vptr_fieldno (context, &context_vptr_basetype);
81fe8080 DE	129	/* FIXME: What to do if vptr_fieldno is still -1? */
015a42b4 JB	130
	131	/* The virtual function table is now an array of structures
	132	which have the form { int16 offset, delta; void pfn; }. /
81fe8080 DE	133	vtbl = value_primitive_field (arg1, 0, context_vptr_fieldno,
81fe8080 DE	134	context_vptr_basetype);
015a42b4 JB	135
	136	/* With older versions of g++, the vtbl field pointed to an array
	137	of structures. Nowadays it points directly to the structure. */
df407dfe AC	138	if (TYPE_CODE (value_type (vtbl)) == TYPE_CODE_PTR
df407dfe AC	139	&& TYPE_CODE (TYPE_TARGET_TYPE (value_type (vtbl))) == TYPE_CODE_ARRAY)
015a42b4 JB	140	{
	141	/* Handle the case where the vtbl field points to an
	142	array of structures. */
	143	vtbl = value_ind (vtbl);
	144
	145	/* Index into the virtual function table. This is hard-coded because
	146	looking up a field is not cheap, and it may be important to save
	147	time, e.g. if the user has set a conditional breakpoint calling
	148	a virtual function. */
	149	entry = value_subscript (vtbl, vi);
	150	}
	151	else
	152	{
	153	/* Handle the case where the vtbl field points directly to a structure. */
	154	vtbl = value_add (vtbl, vi);
	155	entry = value_ind (vtbl);
	156	}
	157
df407dfe	158	entry_type = check_typedef (value_type (entry));
015a42b4 JB	159
	160	if (TYPE_CODE (entry_type) == TYPE_CODE_STRUCT)
	161	{
	162	/* Move the `this' pointer according to the virtual function table. */
f5cf64a7	163	set_value_offset (arg1, value_offset (arg1) + value_as_long (value_field (entry, 0)));
015a42b4	164
d69fe07e	165	if (!value_lazy (arg1))
015a42b4	166	{
dfa52d88	167	set_value_lazy (arg1, 1);
015a42b4 JB	168	value_fetch_lazy (arg1);
	169	}
	170
	171	vfn = value_field (entry, 2);
	172	}
	173	else if (TYPE_CODE (entry_type) == TYPE_CODE_PTR)
	174	vfn = entry;
	175	else
8a3fe4f8	176	error (_("I'm confused: virtual function table has bad type"));
015a42b4	177	/* Reinstantiate the function pointer with the correct type. */
04624583	178	deprecated_set_value_type (vfn, lookup_pointer_type (TYPE_FN_FIELD_TYPE (f, j)));
015a42b4 JB	179
	180	*arg1p = arg1;
	181	return vfn;
	182	}
	183
	184
b9362cc7	185	static struct type *
e933e538	186	gnuv2_value_rtti_type (struct value v, int full, int top, int using_enc)
015a42b4 JB	187	{
	188	struct type *known_type;
	189	struct type *rtti_type;
	190	CORE_ADDR coreptr;
e933e538	191	struct value *vp;
015a42b4 JB	192	long top_offset = 0;
	193	char rtti_type_name[256];
	194	CORE_ADDR vtbl;
	195	struct minimal_symbol *minsym;
	196	struct symbol *sym;
7d63ec12	197	char demangled_name, p;
015a42b4	198	struct type *btype;
81fe8080 DE	199	struct type *known_type_vptr_basetype;
81fe8080 DE	200	int known_type_vptr_fieldno;
015a42b4 JB	201
	202	if (full)
	203	*full = 0;
	204	if (top)
	205	*top = -1;
	206	if (using_enc)
	207	*using_enc = 0;
	208
	209	/* Get declared type */
df407dfe	210	known_type = value_type (v);
015a42b4 JB	211	CHECK_TYPEDEF (known_type);
	212	/* RTTI works only or class objects */
	213	if (TYPE_CODE (known_type) != TYPE_CODE_CLASS)
	214	return NULL;
	215
	216	/* Plan on this changing in the future as i get around to setting
	217	the vtables properly for G++ compiled stuff. Also, I'll be using
	218	the type info functions, which are always right. Deal with it
	219	until then. */
	220
81fe8080 DE	221	/* Try to get the vptr basetype, fieldno. */
	222	known_type_vptr_fieldno = get_vptr_fieldno (known_type,
	223	&known_type_vptr_basetype);
015a42b4	224
81fe8080 DE	225	/* If we can't find it, give up. */
81fe8080 DE	226	if (known_type_vptr_fieldno < 0)
015a42b4 JB	227	return NULL;
	228
	229	/* Make sure our basetype and known type match, otherwise, cast
	230	so we can get at the vtable properly.
	231	*/
81fe8080	232	btype = known_type_vptr_basetype;
015a42b4 JB	233	CHECK_TYPEDEF (btype);
	234	if (btype != known_type )
	235	{
	236	v = value_cast (btype, v);
	237	if (using_enc)
	238	*using_enc=1;
	239	}
	240	/*
	241	We can't use value_ind here, because it would want to use RTTI, and
	242	we'd waste a bunch of time figuring out we already know the type.
	243	Besides, we don't care about the type, just the actual pointer
	244	*/
81fe8080	245	if (VALUE_ADDRESS (value_field (v, known_type_vptr_fieldno)) == 0)
015a42b4 JB	246	return NULL;
015a42b4 JB	247
81fe8080	248	vtbl = value_as_address (value_field (v, known_type_vptr_fieldno));
015a42b4 JB	249
	250	/* Try to find a symbol that is the vtable */
	251	minsym=lookup_minimal_symbol_by_pc(vtbl);
	252	if (minsym==NULL
22abf04a	253	\|\| (demangled_name=DEPRECATED_SYMBOL_NAME (minsym))==NULL
015a42b4 JB	254	\|\| !is_vtable_name (demangled_name))
	255	return NULL;
	256
	257	/* If we just skip the prefix, we get screwed by namespaces */
	258	demangled_name=cplus_demangle(demangled_name,DMGL_PARAMS\|DMGL_ANSI);
7d63ec12 MS	259	p = strchr (demangled_name, ' ');
	260	if (p)
	261	*p = '\0';
015a42b4 JB	262
015a42b4 JB	263	/* Lookup the type for the name */
362ff856 MC	264	/* FIXME: chastain/2003-11-26: block=NULL is bogus. See pr gdb/1465. */
	265	rtti_type = cp_lookup_rtti_type (demangled_name, NULL);
	266	if (rtti_type == NULL)
015a42b4 JB	267	return NULL;
	268
	269	if (TYPE_N_BASECLASSES(rtti_type) > 1 && full && (*full) != 1)
	270	{
	271	if (top)
	272	*top=TYPE_BASECLASS_BITPOS(rtti_type,TYPE_VPTR_FIELDNO(rtti_type))/8;
	273	if (top && ((*top) >0))
	274	{
	275	if (TYPE_LENGTH(rtti_type) > TYPE_LENGTH(known_type))
	276	{
	277	if (full)
	278	*full=0;
	279	}
	280	else
	281	{
	282	if (full)
	283	*full=1;
	284	}
	285	}
	286	}
	287	else
	288	{
	289	if (full)
	290	*full=1;
	291	}
015a42b4 JB	292
	293	return rtti_type;
	294	}
	295
1514d34e DJ	296	/* Return true if the INDEXth field of TYPE is a virtual baseclass
	297	pointer which is for the base class whose type is BASECLASS. */
	298
	299	static int
	300	vb_match (struct type type, int index, struct type basetype)
	301	{
	302	struct type *fieldtype;
	303	char *name = TYPE_FIELD_NAME (type, index);
	304	char *field_class_name = NULL;
	305
	306	if (*name != '_')
	307	return 0;
	308	/* gcc 2.4 uses _vb$. */
	309	if (name[1] == 'v' && name[2] == 'b' && is_cplus_marker (name[3]))
	310	field_class_name = name + 4;
	311	/* gcc 2.5 will use __vb_. */
	312	if (name[1] == '_' && name[2] == 'v' && name[3] == 'b' && name[4] == '_')
	313	field_class_name = name + 5;
	314
	315	if (field_class_name == NULL)
	316	/* This field is not a virtual base class pointer. */
	317	return 0;
	318
	319	/* It's a virtual baseclass pointer, now we just need to find out whether
	320	it is for this baseclass. */
	321	fieldtype = TYPE_FIELD_TYPE (type, index);
	322	if (fieldtype == NULL
	323	\|\| TYPE_CODE (fieldtype) != TYPE_CODE_PTR)
	324	/* "Can't happen". */
	325	return 0;
	326
	327	/* What we check for is that either the types are equal (needed for
	328	nameless types) or have the same name. This is ugly, and a more
	329	elegant solution should be devised (which would probably just push
	330	the ugliness into symbol reading unless we change the stabs format). */
	331	if (TYPE_TARGET_TYPE (fieldtype) == basetype)
	332	return 1;
	333
	334	if (TYPE_NAME (basetype) != NULL
	335	&& TYPE_NAME (TYPE_TARGET_TYPE (fieldtype)) != NULL
bde58177 AC	336	&& strcmp (TYPE_NAME (basetype),
bde58177 AC	337	TYPE_NAME (TYPE_TARGET_TYPE (fieldtype))) == 0)
1514d34e DJ	338	return 1;
	339	return 0;
	340	}
	341
	342	/* Compute the offset of the baseclass which is
	343	the INDEXth baseclass of class TYPE,
	344	for value at VALADDR (in host) at ADDRESS (in target).
	345	The result is the offset of the baseclass value relative
	346	to (the address of)(ARG) + OFFSET.
	347
	348	-1 is returned on error. */
	349
	350	int
06c4d4dc AC	351	gnuv2_baseclass_offset (struct type *type, int index,
06c4d4dc AC	352	const bfd_byte *valaddr, CORE_ADDR address)
1514d34e DJ	353	{
	354	struct type *basetype = TYPE_BASECLASS (type, index);
	355
	356	if (BASETYPE_VIA_VIRTUAL (type, index))
	357	{
	358	/* Must hunt for the pointer to this virtual baseclass. */
aa1ee363 AC	359	int i, len = TYPE_NFIELDS (type);
aa1ee363 AC	360	int n_baseclasses = TYPE_N_BASECLASSES (type);
1514d34e DJ	361
	362	/* First look for the virtual baseclass pointer
	363	in the fields. */
	364	for (i = n_baseclasses; i < len; i++)
	365	{
	366	if (vb_match (type, i, basetype))
	367	{
	368	CORE_ADDR addr
	369	= unpack_pointer (TYPE_FIELD_TYPE (type, i),
	370	valaddr + (TYPE_FIELD_BITPOS (type, i) / 8));
	371
	372	return addr - (LONGEST) address;
	373	}
	374	}
	375	/* Not in the fields, so try looking through the baseclasses. */
	376	for (i = index + 1; i < n_baseclasses; i++)
	377	{
	378	int boffset =
	379	baseclass_offset (type, i, valaddr, address);
	380	if (boffset)
	381	return boffset;
	382	}
	383	/* Not found. */
	384	return -1;
	385	}
	386
	387	/* Baseclass is easily computed. */
	388	return TYPE_BASECLASS_BITPOS (type, index) / 8;
	389	}
015a42b4 JB	390
	391	static void
	392	init_gnuv2_ops (void)
	393	{
	394	gnu_v2_abi_ops.shortname = "gnu-v2";
	395	gnu_v2_abi_ops.longname = "GNU G++ Version 2 ABI";
	396	gnu_v2_abi_ops.doc = "G++ Version 2 ABI";
	397	gnu_v2_abi_ops.is_destructor_name = gnuv2_is_destructor_name;
	398	gnu_v2_abi_ops.is_constructor_name = gnuv2_is_constructor_name;
	399	gnu_v2_abi_ops.is_vtable_name = gnuv2_is_vtable_name;
	400	gnu_v2_abi_ops.is_operator_name = gnuv2_is_operator_name;
	401	gnu_v2_abi_ops.virtual_fn_field = gnuv2_virtual_fn_field;
	402	gnu_v2_abi_ops.rtti_type = gnuv2_value_rtti_type;
1514d34e	403	gnu_v2_abi_ops.baseclass_offset = gnuv2_baseclass_offset;
015a42b4 JB	404	}
015a42b4 JB	405
b9362cc7 AC	406	extern initialize_file_ftype _initialize_gnu_v2_abi; /* -Wmissing-prototypes */
b9362cc7 AC	407
015a42b4 JB	408	void
	409	_initialize_gnu_v2_abi (void)
	410	{
	411	init_gnuv2_ops ();
fe1f4a5e DJ	412	register_cp_abi (&gnu_v2_abi_ops);
fe1f4a5e DJ	413	set_cp_abi_as_auto_default (gnu_v2_abi_ops.shortname);
015a42b4	414	}