gdb/hpacc-abi.c

   1 /* Abstraction of HP aCC ABI.
   2
   3    Contributed by Daniel Berlin <dberlin@redhat.com>
   4    Most of the real code is from HP, i've just fiddled it to fit in
   5    the C++ ABI abstraction framework.
   6
   7    Copyright (C) 2001, 2005, 2007 Free Software Foundation, Inc.
   8
   9    This file is part of GDB.
  10
  11    This program is free software; you can redistribute it and/or
  12    modify
  13    it under the terms of the GNU General Public License as published
  14    by
  15    the Free Software Foundation; either version 2 of the License, or
  16    (at your option) any later version.
  17
  18    This program is distributed in the hope that it will be useful,
  19    but WITHOUT ANY WARRANTY; without even the implied warranty of
  20    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21    GNU General Public License for more details.
  22
  23    You should have received a copy of the GNU General Public License
  24    along with this program; if not, write to the Free Software
  25    Foundation, Inc., 51 Franklin Street, Fifth Floor,
  26    Boston, MA 02110-1301, USA.  */
  27
  28 #include "defs.h"
  29 #include "value.h"
  30 #include "gdb_regex.h"
  31 #include "gdb_string.h"
  32 #include "gdbtypes.h"
  33 #include "gdbcore.h"
  34 #include "cp-abi.h"
  35 #include "gnu-v2-abi.h"
  36
  37 struct cp_abi_ops hpacc_abi_ops;
  38
  39 /* It appears the is_*_name stuff is never used when we try the hpACC
  40  * ABI. As such, I have no clue what the real answers are. Shouldn't
  41  * have any more effect than it does now.  */
  42 static regex_t constructor_pattern;
  43 static regex_t destructor_pattern;
  44 static regex_t operator_pattern;
  45
  46 static enum dtor_kinds
  47 hpacc_is_destructor_name (const char *name)
  48 {
  49   if (regexec (&destructor_pattern, name, 0, 0, 0) == 0)
  50     return complete_object_dtor;
  51   else
  52     return 0;
  53 }
  54
  55 static enum ctor_kinds
  56 hpacc_is_constructor_name (const char *name)
  57 {
  58   if (regexec (&constructor_pattern, name, 0, 0, 0) == 0)
  59     return complete_object_ctor;
  60   else
  61     return 0;
  62 }
  63
  64 static int
  65 hpacc_is_operator_name (const char *name)
  66 {
  67   return regexec (&operator_pattern, name, 0, 0, 0) == 0;
  68 }
  69
  70 static int
  71 hpacc_is_vtable_name (const char *name)
  72 {
  73   return strcmp (name,
  74                  "This will never match anything, please fill it in") == 0;
  75 }
  76
  77 /* Return a virtual function as a value.
  78    ARG1 is the object which provides the virtual function
  79    table pointer.  *ARG1P is side-effected in calling this function.
  80    F is the list of member functions which contains the desired virtual
  81    function.
  82    J is an index into F which provides the desired virtual function.
  83
  84    TYPE is the type in which F is located.  */
  85 static struct value *
  86 hpacc_virtual_fn_field (struct value **arg1p, struct fn_field * f, int j,
  87                         struct type * type, int offset)
  88 {
  89   struct value *arg1 = *arg1p;
  90   struct type *type1 = check_typedef (value_type (arg1));
  91
  92   /* Deal with HP/Taligent runtime model for virtual functions */
  93   struct value *vp;
  94   struct value *argp;           /* arg1 cast to base */
  95   CORE_ADDR coreptr;            /* pointer to target address */
  96   int class_index;              /* which class segment pointer to use */
  97   struct type *ftype = TYPE_FN_FIELD_TYPE (f, j);       /* method type */
  98
  99   argp = value_cast (type, *arg1p);
 100
 101   if (VALUE_ADDRESS (argp) == 0)
 102     error (_("Address of object is null; object may not have been created."));
 103
 104   /* pai: FIXME -- 32x64 possible problem? */
 105   /* First word (4 bytes) in object layout is the vtable pointer */
 106   coreptr = *(CORE_ADDR *) (value_contents (argp));     /* pai: (temp)  */
 107   /* + offset + value_embedded_offset (argp)); */
 108
 109   if (!coreptr)
 110     error
 111       ("Virtual table pointer is null for object; object may not have been created.");
 112
 113   /* pai/1997-05-09
 114    * FIXME: The code here currently handles only
 115    * the non-RRBC case of the Taligent/HP runtime spec; when RRBC
 116    * is introduced, the condition for the "if" below will have to
 117    * be changed to be a test for the RRBC case.  */
 118
 119   if (1)
 120     {
 121       /* Non-RRBC case; the virtual function pointers are stored at fixed
 122        * offsets in the virtual table. */
 123
 124       /* Retrieve the offset in the virtual table from the debug
 125        * info.  The offset of the vfunc's entry is in words from
 126        * the beginning of the vtable; but first we have to adjust
 127        * by HP_ACC_VFUNC_START to account for other entries */
 128
 129       /* pai: FIXME: 32x64 problem here, a word may be 8 bytes in
 130        * which case the multiplier should be 8 and values should be long */
 131       vp = value_at (builtin_type_int,
 132                      coreptr + 4 * (TYPE_FN_FIELD_VOFFSET (f, j) +
 133                                     HP_ACC_VFUNC_START));
 134
 135       coreptr = *(CORE_ADDR *) (value_contents (vp));
 136       /* coreptr now contains the address of the virtual function */
 137       /* (Actually, it contains the pointer to the plabel for the function. */
 138     }
 139   else
 140     {
 141       /* RRBC case; the virtual function pointers are found by double
 142        * indirection through the class segment tables. */
 143
 144       /* Choose class segment depending on type we were passed */
 145       class_index = class_index_in_primary_list (type);
 146
 147       /* Find class segment pointer.  These are in the vtable slots after
 148        * some other entries, so adjust by HP_ACC_VFUNC_START for that. */
 149       /* pai: FIXME 32x64 problem here, if words are 8 bytes long
 150        * the multiplier below has to be 8 and value should be long. */
 151       vp = value_at (builtin_type_int,
 152                      coreptr + 4 * (HP_ACC_VFUNC_START + class_index));
 153       /* Indirect once more, offset by function index */
 154       /* pai: FIXME 32x64 problem here, again multiplier could be 8 and value long */
 155       coreptr =
 156         *(CORE_ADDR *) (value_contents (vp) +
 157                         4 * TYPE_FN_FIELD_VOFFSET (f, j));
 158       vp = value_at (builtin_type_int, coreptr);
 159       coreptr = *(CORE_ADDR *) (value_contents (vp));
 160
 161       /* coreptr now contains the address of the virtual function */
 162       /* (Actually, it contains the pointer to the plabel for the function.) */
 163
 164     }
 165
 166   if (!coreptr)
 167     error (_("Address of virtual function is null; error in virtual table?"));
 168
 169   /* Wrap this addr in a value and return pointer */
 170   vp = allocate_value (ftype);
 171   deprecated_set_value_type (vp, ftype);
 172   VALUE_ADDRESS (vp) = coreptr;
 173
 174   /* pai: (temp) do we need the value_ind stuff in value_fn_field? */
 175   return vp;
 176 }
 177
 178
 179 static struct type *
 180 hpacc_value_rtti_type (struct value *v, int *full, int *top, int *using_enc)
 181 {
 182   struct type *known_type;
 183   struct type *rtti_type;
 184   CORE_ADDR coreptr;
 185   struct value *vp;
 186   int using_enclosing = 0;
 187   long top_offset = 0;
 188   char rtti_type_name[256];
 189
 190   if (full)
 191     *full = 0;
 192   if (top)
 193     *top = -1;
 194   if (using_enc)
 195     *using_enc = 0;
 196
 197   /* Get declared type */
 198   known_type = value_type (v);
 199   CHECK_TYPEDEF (known_type);
 200   /* RTTI works only or class objects */
 201   if (TYPE_CODE (known_type) != TYPE_CODE_CLASS)
 202     return NULL;
 203
 204   /* If neither the declared type nor the enclosing type of the
 205    * value structure has a HP ANSI C++ style virtual table,
 206    * we can't do anything. */
 207   if (!TYPE_HAS_VTABLE (known_type))
 208     {
 209       known_type = value_enclosing_type (v);
 210       CHECK_TYPEDEF (known_type);
 211       if ((TYPE_CODE (known_type) != TYPE_CODE_CLASS) ||
 212           !TYPE_HAS_VTABLE (known_type))
 213         return NULL;            /* No RTTI, or not HP-compiled types */
 214       CHECK_TYPEDEF (known_type);
 215       using_enclosing = 1;
 216     }
 217
 218   if (using_enclosing && using_enc)
 219     *using_enc = 1;
 220
 221   /* First get the virtual table address */
 222   coreptr = *(CORE_ADDR *) ((value_contents_all (v))
 223                             + value_offset (v)
 224                             + (using_enclosing
 225                                ? 0
 226                                : value_embedded_offset (v)));
 227   if (coreptr == 0)
 228     /* return silently -- maybe called on gdb-generated value */
 229     return NULL;
 230
 231   /* Fetch the top offset of the object */
 232   /* FIXME possible 32x64 problem with pointer size & arithmetic */
 233   vp = value_at (builtin_type_int,
 234                  coreptr + 4 * HP_ACC_TOP_OFFSET_OFFSET);
 235   top_offset = value_as_long (vp);
 236   if (top)
 237     *top = top_offset;
 238
 239   /* Fetch the typeinfo pointer */
 240   /* FIXME possible 32x64 problem with pointer size & arithmetic */
 241   vp = value_at (builtin_type_int, coreptr + 4 * HP_ACC_TYPEINFO_OFFSET);
 242   /* Indirect through the typeinfo pointer and retrieve the pointer
 243    * to the string name */
 244   coreptr = *(CORE_ADDR *) (value_contents (vp));
 245   if (!coreptr)
 246     error (_("Retrieved null typeinfo pointer in trying to determine "
 247            "run-time type"));
 248   /* 4 -> offset of name field */
 249   vp = value_at (builtin_type_int, coreptr + 4);
 250   /* FIXME possible 32x64 problem */
 251
 252   coreptr = *(CORE_ADDR *) (value_contents (vp));
 253
 254   read_memory_string (coreptr, rtti_type_name, 256);
 255
 256   if (strlen (rtti_type_name) == 0)
 257     error (_("Retrieved null type name from typeinfo"));
 258
 259   /* search for type */
 260   rtti_type = lookup_typename (rtti_type_name, (struct block *) 0, 1);
 261
 262   if (!rtti_type)
 263     error (_("Could not find run-time type: invalid type name %s in typeinfo??"),
 264            rtti_type_name);
 265   CHECK_TYPEDEF (rtti_type);
 266 #if 0
 267   printf ("RTTI type name %s, tag %s, full? %d\n", TYPE_NAME (rtti_type),
 268           TYPE_TAG_NAME (rtti_type), full ? *full : -1);
 269 #endif
 270   /* Check whether we have the entire object */
 271   if (full                      /* Non-null pointer passed */
 272       &&
 273       /* Either we checked on the whole object in hand and found the
 274          top offset to be zero */
 275       (((top_offset == 0) &&
 276         using_enclosing &&
 277         TYPE_LENGTH (known_type) == TYPE_LENGTH (rtti_type))
 278        ||
 279        /* Or we checked on the embedded object and top offset was the
 280           same as the embedded offset */
 281        ((top_offset == value_embedded_offset (v)) &&
 282         !using_enclosing &&
 283         TYPE_LENGTH (value_enclosing_type (v)) == TYPE_LENGTH (rtti_type))))
 284
 285     *full = 1;
 286
 287   return rtti_type;
 288 }
 289
 290 static void
 291 init_hpacc_ops (void)
 292 {
 293   hpacc_abi_ops.shortname = "hpaCC";
 294   hpacc_abi_ops.longname = "HP aCC ABI";
 295   hpacc_abi_ops.doc = "HP aCC ABI";
 296   hpacc_abi_ops.is_destructor_name = hpacc_is_destructor_name;
 297   hpacc_abi_ops.is_constructor_name = hpacc_is_constructor_name;
 298   hpacc_abi_ops.is_vtable_name = hpacc_is_vtable_name;
 299   hpacc_abi_ops.is_operator_name = hpacc_is_operator_name;
 300   hpacc_abi_ops.virtual_fn_field = hpacc_virtual_fn_field;
 301   hpacc_abi_ops.rtti_type = hpacc_value_rtti_type;
 302   /* It seems that this function is specific to GNU G++ < 3.0.
 303      However, it is called for data members even in the HP
 304      case (although not for member functions).
 305      FIXME: Is that correct?  */
 306   hpacc_abi_ops.baseclass_offset = gnuv2_baseclass_offset;
 307 }
 308
 309 extern initialize_file_ftype _initialize_hpacc_abi; /* -Wmissing-prototypes */
 310
 311 void
 312 _initialize_hpacc_abi (void)
 313 {
 314   init_hpacc_ops ();
 315
 316   regcomp (&constructor_pattern,
 317            "^This will never match anything, please fill it in$", REG_NOSUB);
 318
 319   regcomp (&destructor_pattern,
 320            "^This will never match anything, please fill it in$", REG_NOSUB);
 321
 322   regcomp (&operator_pattern,
 323            "^This will never match anything, please fill it in$", REG_NOSUB);
 324
 325   register_cp_abi (&hpacc_abi_ops);
 326 }