gcc/ada/gcc-interface/ada-tree.h

   1 /****************************************************************************
   2  *                                                                          *
   3  *                         GNAT COMPILER COMPONENTS                         *
   4  *                                                                          *
   5  *                             A D A - T R E E                              *
   6  *                                                                          *
   7  *                              C Header File                               *
   8  *                                                                          *
   9  *          Copyright (C) 1992-2011, Free Software Foundation, Inc.         *
  10  *                                                                          *
  11  * GNAT is free software;  you can  redistribute it  and/or modify it under *
  12  * terms of the  GNU General Public License as published  by the Free Soft- *
  13  * ware  Foundation;  either version 3,  or (at your option) any later ver- *
  14  * sion.  GNAT is distributed in the hope that it will be useful, but WITH- *
  15  * OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY *
  16  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License *
  17  * for  more details.  You should have received a copy of the GNU General   *
  18  * Public License along with GCC; see the file COPYING3.  If not see        *
  19  * <http://www.gnu.org/licenses/>.                                          *
  20  *                                                                          *
  21  * GNAT was originally developed  by the GNAT team at  New York University. *
  22  * Extensive contributions were provided by Ada Core Technologies Inc.      *
  23  *                                                                          *
  24  ****************************************************************************/
  25
  26 /* The resulting tree type.  */
  27 union GTY((desc ("0"),
  28            chain_next ("CODE_CONTAINS_STRUCT (TREE_CODE (&%h.generic), TS_COMMON) ? ((union lang_tree_node *) TREE_CHAIN (&%h.generic)) : NULL")))
  29   lang_tree_node
  30 {
  31   union tree_node GTY((tag ("0"),
  32                        desc ("tree_node_structure (&%h)"))) generic;
  33 };
  34
  35 /* Ada uses the lang_decl and lang_type fields to hold a tree.
  36
  37    FIXME: the variable_size annotation here is needed because these types are
  38    variable-sized in some other front-ends.  Due to gengtype deficiency, the
  39    GTY options of such types have to agree across all front-ends.  */
  40 struct GTY((variable_size)) lang_type { tree t; };
  41 struct GTY((variable_size)) lang_decl { tree t; };
  42
  43 /* Macros to get and set the tree in TYPE_LANG_SPECIFIC.  */
  44 #define GET_TYPE_LANG_SPECIFIC(NODE) \
  45   (TYPE_LANG_SPECIFIC (NODE) ? TYPE_LANG_SPECIFIC (NODE)->t : NULL_TREE)
  46
  47 #define SET_TYPE_LANG_SPECIFIC(NODE, X)                  \
  48 do {                                                     \
  49   tree tmp = (X);                                        \
  50   if (!TYPE_LANG_SPECIFIC (NODE))                        \
  51     TYPE_LANG_SPECIFIC (NODE)                            \
  52       = ggc_alloc_lang_type (sizeof (struct lang_type)); \
  53   TYPE_LANG_SPECIFIC (NODE)->t = tmp;                    \
  54 } while (0)
  55
  56 /* Macros to get and set the tree in DECL_LANG_SPECIFIC.  */
  57 #define GET_DECL_LANG_SPECIFIC(NODE) \
  58   (DECL_LANG_SPECIFIC (NODE) ? DECL_LANG_SPECIFIC (NODE)->t : NULL_TREE)
  59
  60 #define SET_DECL_LANG_SPECIFIC(NODE, X)                  \
  61 do {                                                     \
  62   tree tmp = (X);                                        \
  63   if (!DECL_LANG_SPECIFIC (NODE))                        \
  64     DECL_LANG_SPECIFIC (NODE)                            \
  65       = ggc_alloc_lang_decl (sizeof (struct lang_decl)); \
  66   DECL_LANG_SPECIFIC (NODE)->t = tmp;                    \
  67 } while (0)
  68
  69
  70 /* Flags added to type nodes.  */
  71
  72 /* For RECORD_TYPE, UNION_TYPE, and QUAL_UNION_TYPE, nonzero if this is a
  73    record being used as a fat pointer (only true for RECORD_TYPE).  */
  74 #define TYPE_FAT_POINTER_P(NODE) \
  75   TYPE_LANG_FLAG_0 (RECORD_OR_UNION_CHECK (NODE))
  76
  77 #define TYPE_IS_FAT_POINTER_P(NODE) \
  78   (TREE_CODE (NODE) == RECORD_TYPE && TYPE_FAT_POINTER_P (NODE))
  79
  80 /* For integral types and array types, nonzero if this is a packed array type
  81    used for bit-packed types.  Such types should not be extended to a larger
  82    size or validated against a specified size.  */
  83 #define TYPE_PACKED_ARRAY_TYPE_P(NODE) TYPE_LANG_FLAG_0 (NODE)
  84
  85 #define TYPE_IS_PACKED_ARRAY_TYPE_P(NODE) \
  86   ((TREE_CODE (NODE) == INTEGER_TYPE || TREE_CODE (NODE) == ARRAY_TYPE) \
  87    && TYPE_PACKED_ARRAY_TYPE_P (NODE))
  88
  89 /* For INTEGER_TYPE, nonzero if this is a modular type with a modulus that
  90    is not equal to two to the power of its mode's size.  */
  91 #define TYPE_MODULAR_P(NODE) TYPE_LANG_FLAG_1 (INTEGER_TYPE_CHECK (NODE))
  92
  93 /* For ARRAY_TYPE, nonzero if this type corresponds to a dimension of
  94    an Ada array other than the first.  */
  95 #define TYPE_MULTI_ARRAY_P(NODE) TYPE_LANG_FLAG_1 (ARRAY_TYPE_CHECK (NODE))
  96
  97 /* For FUNCTION_TYPE, nonzero if this denotes a function returning an
  98    unconstrained array or record.  */
  99 #define TYPE_RETURN_UNCONSTRAINED_P(NODE) \
 100   TYPE_LANG_FLAG_1 (FUNCTION_TYPE_CHECK (NODE))
 101
 102 /* For RECORD_TYPE, UNION_TYPE, and QUAL_UNION_TYPE, nonzero if this denotes
 103    a justified modular type (will only be true for RECORD_TYPE).  */
 104 #define TYPE_JUSTIFIED_MODULAR_P(NODE) \
 105   TYPE_LANG_FLAG_1 (RECORD_OR_UNION_CHECK (NODE))
 106
 107 /* Nonzero in an arithmetic subtype if this is a subtype not known to the
 108    front-end.  */
 109 #define TYPE_EXTRA_SUBTYPE_P(NODE) TYPE_LANG_FLAG_2 (INTEGER_TYPE_CHECK (NODE))
 110
 111 /* For RECORD_TYPE, UNION_TYPE, and QUAL_UNION_TYPE, nonzero if this is the
 112    type for an object whose type includes its template in addition to
 113    its value (only true for RECORD_TYPE).  */
 114 #define TYPE_CONTAINS_TEMPLATE_P(NODE) \
 115   TYPE_LANG_FLAG_3 (RECORD_OR_UNION_CHECK (NODE))
 116
 117 /* For INTEGER_TYPE, nonzero if this really represents a VAX
 118    floating-point type.  */
 119 #define TYPE_VAX_FLOATING_POINT_P(NODE) \
 120   TYPE_LANG_FLAG_3 (INTEGER_TYPE_CHECK (NODE))
 121
 122 /* True if NODE is a thin pointer.  */
 123 #define TYPE_IS_THIN_POINTER_P(NODE)                    \
 124   (POINTER_TYPE_P (NODE)                                \
 125    && TREE_CODE (TREE_TYPE (NODE)) == RECORD_TYPE       \
 126    && TYPE_CONTAINS_TEMPLATE_P (TREE_TYPE (NODE)))
 127
 128 /* True if TYPE is either a fat or thin pointer to an unconstrained
 129    array.  */
 130 #define TYPE_IS_FAT_OR_THIN_POINTER_P(NODE) \
 131   (TYPE_IS_FAT_POINTER_P (NODE) || TYPE_IS_THIN_POINTER_P (NODE))
 132
 133 /* For INTEGER_TYPEs, nonzero if the type has a biased representation.  */
 134 #define TYPE_BIASED_REPRESENTATION_P(NODE) \
 135   TYPE_LANG_FLAG_4 (INTEGER_TYPE_CHECK (NODE))
 136
 137 /* For ARRAY_TYPEs, nonzero if the array type has Convention_Fortran.  */
 138 #define TYPE_CONVENTION_FORTRAN_P(NODE) \
 139   TYPE_LANG_FLAG_4 (ARRAY_TYPE_CHECK (NODE))
 140
 141 /* For FUNCTION_TYPEs, nonzero if the function returns by direct reference,
 142    i.e. the callee returns a pointer to a memory location it has allocated
 143    and the caller only needs to dereference the pointer.  */
 144 #define TYPE_RETURN_BY_DIRECT_REF_P(NODE) \
 145   TYPE_LANG_FLAG_4 (FUNCTION_TYPE_CHECK (NODE))
 146
 147 /* For VOID_TYPE, ENUMERAL_TYPE, UNION_TYPE, and RECORD_TYPE, nonzero if this
 148    is a dummy type, made to correspond to a private or incomplete type.  */
 149 #define TYPE_DUMMY_P(NODE) TYPE_LANG_FLAG_4 (NODE)
 150
 151 #define TYPE_IS_DUMMY_P(NODE) \
 152   ((TREE_CODE (NODE) == VOID_TYPE || TREE_CODE (NODE) == RECORD_TYPE    \
 153     || TREE_CODE (NODE) == UNION_TYPE || TREE_CODE (NODE) == ENUMERAL_TYPE) \
 154    && TYPE_DUMMY_P (NODE))
 155
 156 /* For an INTEGER_TYPE, nonzero if TYPE_ACTUAL_BOUNDS is present.  */
 157 #define TYPE_HAS_ACTUAL_BOUNDS_P(NODE) \
 158   TYPE_LANG_FLAG_5 (INTEGER_TYPE_CHECK (NODE))
 159
 160 /* For a RECORD_TYPE, nonzero if this was made just to supply needed
 161    padding or alignment.  */
 162 #define TYPE_PADDING_P(NODE) TYPE_LANG_FLAG_5 (RECORD_TYPE_CHECK (NODE))
 163
 164 #define TYPE_IS_PADDING_P(NODE) \
 165   (TREE_CODE (NODE) == RECORD_TYPE && TYPE_PADDING_P (NODE))
 166
 167 /* True if TYPE can alias any other types.  */
 168 #define TYPE_UNIVERSAL_ALIASING_P(NODE) TYPE_LANG_FLAG_6 (NODE)
 169
 170 /* In an UNCONSTRAINED_ARRAY_TYPE, this is the record containing both the
 171    template and the object.
 172
 173    ??? We also put this on an ENUMERAL_TYPE that is dummy.  Technically,
 174    this is a conflict on the minval field, but there doesn't seem to be
 175    simple fix, so we'll live with this kludge for now.  */
 176 #define TYPE_OBJECT_RECORD_TYPE(NODE) \
 177   (TYPE_MINVAL (TREE_CHECK2 ((NODE), UNCONSTRAINED_ARRAY_TYPE, ENUMERAL_TYPE)))
 178
 179 /* For numerical types, this is the GCC lower bound of the type.  The GCC
 180    type system is based on the invariant that an object X of a given type
 181    cannot hold at run time a value smaller than its lower bound; otherwise
 182    the behavior is undefined.  The optimizer takes advantage of this and
 183    considers that the assertion X >= LB is always true.  */
 184 #define TYPE_GCC_MIN_VALUE(NODE) (TYPE_MINVAL (NUMERICAL_TYPE_CHECK (NODE)))
 185
 186 /* For numerical types, this is the GCC upper bound of the type.  The GCC
 187    type system is based on the invariant that an object X of a given type
 188    cannot hold at run time a value larger than its upper bound; otherwise
 189    the behavior is undefined.  The optimizer takes advantage of this and
 190    considers that the assertion X <= UB is always true.  */
 191 #define TYPE_GCC_MAX_VALUE(NODE) (TYPE_MAXVAL (NUMERICAL_TYPE_CHECK (NODE)))
 192
 193 /* For a FUNCTION_TYPE, if the subprogram has parameters passed by copy in/
 194    copy out, this is the list of nodes used to specify the return values of
 195    the out (or in out) parameters that are passed by copy in/copy out.  For
 196    a full description of the copy in/copy out parameter passing mechanism
 197    refer to the routine gnat_to_gnu_entity.  */
 198 #define TYPE_CI_CO_LIST(NODE) TYPE_LANG_SLOT_1 (FUNCTION_TYPE_CHECK (NODE))
 199
 200 /* For a VECTOR_TYPE, this is the representative array type.  */
 201 #define TYPE_REPRESENTATIVE_ARRAY(NODE) \
 202   TYPE_LANG_SLOT_1 (VECTOR_TYPE_CHECK (NODE))
 203
 204 /* For numerical types, this holds various RM-defined values.  */
 205 #define TYPE_RM_VALUES(NODE) TYPE_LANG_SLOT_1 (NUMERICAL_TYPE_CHECK (NODE))
 206
 207 /* Macros to get and set the individual values in TYPE_RM_VALUES.  */
 208 #define TYPE_RM_VALUE(NODE, N)                              \
 209   (TYPE_RM_VALUES (NODE)                                    \
 210    ? TREE_VEC_ELT (TYPE_RM_VALUES (NODE), (N)) : NULL_TREE)
 211
 212 #define SET_TYPE_RM_VALUE(NODE, N, X)              \
 213 do {                                               \
 214   tree tmp = (X);                                  \
 215   if (!TYPE_RM_VALUES (NODE))                      \
 216     TYPE_RM_VALUES (NODE) = make_tree_vec (3);     \
 217   /* ??? The field is not visited by the generic   \
 218      code so we need to mark it manually.  */      \
 219   MARK_VISITED (tmp);                              \
 220   TREE_VEC_ELT (TYPE_RM_VALUES (NODE), (N)) = tmp; \
 221 } while (0)
 222
 223 /* For numerical types, this is the RM size of the type, aka its precision.
 224    There is a discrepancy between what is called precision here (and more
 225    generally throughout gigi) and what is called precision in the GCC type
 226    system: in the former case it's TYPE_RM_SIZE whereas it's TYPE_PRECISION
 227    in the latter case.  They are not identical because of the need to support
 228    invalid values.
 229
 230    These values can be outside the range of values allowed by the RM size
 231    but they must nevertheless be valid in the GCC type system, otherwise
 232    the optimizer can pretend that they simply don't exist.  Therefore they
 233    must be within the range of values allowed by the precision in the GCC
 234    sense, hence TYPE_PRECISION be set to the Esize, not the RM size.  */
 235 #define TYPE_RM_SIZE(NODE) TYPE_RM_VALUE ((NODE), 0)
 236 #define SET_TYPE_RM_SIZE(NODE, X) SET_TYPE_RM_VALUE ((NODE), 0, (X))
 237
 238 /* For numerical types, this is the RM lower bound of the type.  There is
 239    again a discrepancy between this lower bound and the GCC lower bound,
 240    again because of the need to support invalid values.
 241
 242    These values can be outside the range of values allowed by the RM lower
 243    bound but they must nevertheless be valid in the GCC type system, otherwise
 244    the optimizer can pretend that they simply don't exist.  Therefore they
 245    must be within the range of values allowed by the lower bound in the GCC
 246    sense, hence the GCC lower bound be set to that of the base type.  */
 247 #define TYPE_RM_MIN_VALUE(NODE) TYPE_RM_VALUE ((NODE), 1)
 248 #define SET_TYPE_RM_MIN_VALUE(NODE, X) SET_TYPE_RM_VALUE ((NODE), 1, (X))
 249
 250 /* For numerical types, this is the RM upper bound of the type.  There is
 251    again a discrepancy between this upper bound and the GCC upper bound,
 252    again because of the need to support invalid values.
 253
 254    These values can be outside the range of values allowed by the RM upper
 255    bound but they must nevertheless be valid in the GCC type system, otherwise
 256    the optimizer can pretend that they simply don't exist.  Therefore they
 257    must be within the range of values allowed by the upper bound in the GCC
 258    sense, hence the GCC upper bound be set to that of the base type.  */
 259 #define TYPE_RM_MAX_VALUE(NODE) TYPE_RM_VALUE ((NODE), 2)
 260 #define SET_TYPE_RM_MAX_VALUE(NODE, X) SET_TYPE_RM_VALUE ((NODE), 2, (X))
 261
 262 /* For numerical types, this is the lower bound of the type, i.e. the RM lower
 263    bound for language-defined types and the GCC lower bound for others.  */
 264 #undef TYPE_MIN_VALUE
 265 #define TYPE_MIN_VALUE(NODE) \
 266   (TYPE_RM_MIN_VALUE (NODE) \
 267    ? TYPE_RM_MIN_VALUE (NODE) : TYPE_GCC_MIN_VALUE (NODE))
 268
 269 /* For numerical types, this is the upper bound of the type, i.e. the RM upper
 270    bound for language-defined types and the GCC upper bound for others.  */
 271 #undef TYPE_MAX_VALUE
 272 #define TYPE_MAX_VALUE(NODE) \
 273   (TYPE_RM_MAX_VALUE (NODE) \
 274    ? TYPE_RM_MAX_VALUE (NODE) : TYPE_GCC_MAX_VALUE (NODE))
 275
 276 /* For an INTEGER_TYPE with TYPE_MODULAR_P, this is the value of the
 277    modulus. */
 278 #define TYPE_MODULUS(NODE) GET_TYPE_LANG_SPECIFIC (INTEGER_TYPE_CHECK (NODE))
 279 #define SET_TYPE_MODULUS(NODE, X) \
 280   SET_TYPE_LANG_SPECIFIC (INTEGER_TYPE_CHECK (NODE), X)
 281
 282 /* For an INTEGER_TYPE with TYPE_VAX_FLOATING_POINT_P, this is the
 283    Digits_Value.  */
 284 #define TYPE_DIGITS_VALUE(NODE) \
 285   GET_TYPE_LANG_SPECIFIC (INTEGER_TYPE_CHECK (NODE))
 286 #define SET_TYPE_DIGITS_VALUE(NODE, X) \
 287   SET_TYPE_LANG_SPECIFIC (INTEGER_TYPE_CHECK (NODE), X)
 288
 289 /* For an INTEGER_TYPE that is the TYPE_DOMAIN of some ARRAY_TYPE, this is
 290    the type corresponding to the Ada index type.  */
 291 #define TYPE_INDEX_TYPE(NODE) \
 292   GET_TYPE_LANG_SPECIFIC (INTEGER_TYPE_CHECK (NODE))
 293 #define SET_TYPE_INDEX_TYPE(NODE, X) \
 294   SET_TYPE_LANG_SPECIFIC (INTEGER_TYPE_CHECK (NODE), X)
 295
 296 /* For an INTEGER_TYPE with TYPE_HAS_ACTUAL_BOUNDS_P or an ARRAY_TYPE, this is
 297    the index type that should be used when the actual bounds are required for
 298    a template.  This is used in the case of packed arrays.  */
 299 #define TYPE_ACTUAL_BOUNDS(NODE) \
 300   GET_TYPE_LANG_SPECIFIC (TREE_CHECK2 (NODE, INTEGER_TYPE, ARRAY_TYPE))
 301 #define SET_TYPE_ACTUAL_BOUNDS(NODE, X) \
 302   SET_TYPE_LANG_SPECIFIC (TREE_CHECK2 (NODE, INTEGER_TYPE, ARRAY_TYPE), X)
 303
 304 /* For a RECORD_TYPE that is a fat pointer, this is the type for the
 305    unconstrained object.  Likewise for a RECORD_TYPE that is pointed
 306    to by a thin pointer.  */
 307 #define TYPE_UNCONSTRAINED_ARRAY(NODE) \
 308   GET_TYPE_LANG_SPECIFIC (RECORD_TYPE_CHECK (NODE))
 309 #define SET_TYPE_UNCONSTRAINED_ARRAY(NODE, X) \
 310   SET_TYPE_LANG_SPECIFIC (RECORD_TYPE_CHECK (NODE), X)
 311
 312 /* For other RECORD_TYPEs and all UNION_TYPEs and QUAL_UNION_TYPEs, this is
 313    the Ada size of the object.  This differs from the GCC size in that it
 314    does not include any rounding up to the alignment of the type.  */
 315 #define TYPE_ADA_SIZE(NODE) \
 316   GET_TYPE_LANG_SPECIFIC (RECORD_OR_UNION_CHECK (NODE))
 317 #define SET_TYPE_ADA_SIZE(NODE, X) \
 318   SET_TYPE_LANG_SPECIFIC (RECORD_OR_UNION_CHECK (NODE), X)
 319
 320
 321 /* Flags added to decl nodes.  */
 322
 323 /* Nonzero in a FUNCTION_DECL that represents a stubbed function
 324    discriminant.  */
 325 #define DECL_STUBBED_P(NODE) DECL_LANG_FLAG_0 (FUNCTION_DECL_CHECK (NODE))
 326
 327 /* Nonzero in a VAR_DECL if it is guaranteed to be constant after having
 328    been elaborated and TREE_READONLY is not set on it.  */
 329 #define DECL_READONLY_ONCE_ELAB(NODE) DECL_LANG_FLAG_0 (VAR_DECL_CHECK (NODE))
 330
 331 /* Nonzero in a CONST_DECL if its value is (essentially) the address of a
 332    constant CONSTRUCTOR.  */
 333 #define DECL_CONST_ADDRESS_P(NODE) DECL_LANG_FLAG_0 (CONST_DECL_CHECK (NODE))
 334
 335 /* Nonzero in a PARM_DECL if it is always used by double reference, i.e. a
 336    pair of INDIRECT_REFs is needed to access the object.  */
 337 #define DECL_BY_DOUBLE_REF_P(NODE) DECL_LANG_FLAG_0 (PARM_DECL_CHECK (NODE))
 338
 339 /* Nonzero in a TYPE_DECL if this is the declaration of a Taft amendment type
 340    in the main unit, i.e. the full declaration is available.  */
 341 #define DECL_TAFT_TYPE_P(NODE) DECL_LANG_FLAG_0 (TYPE_DECL_CHECK (NODE))
 342
 343 /* Nonzero in a DECL if it is always used by reference, i.e. an INDIRECT_REF
 344    is needed to access the object.  */
 345 #define DECL_BY_REF_P(NODE) DECL_LANG_FLAG_1 (NODE)
 346
 347 /* Nonzero in a FIELD_DECL that is a dummy built for some internal reason.  */
 348 #define DECL_INTERNAL_P(NODE) DECL_LANG_FLAG_3 (FIELD_DECL_CHECK (NODE))
 349
 350 /* Nonzero in a PARM_DECL if it is made for an Ada array being passed to a
 351    foreign convention subprogram.  */
 352 #define DECL_BY_COMPONENT_PTR_P(NODE) DECL_LANG_FLAG_3 (PARM_DECL_CHECK (NODE))
 353
 354 /* Nonzero in a FUNCTION_DECL that corresponds to an elaboration procedure.  */
 355 #define DECL_ELABORATION_PROC_P(NODE) \
 356   DECL_LANG_FLAG_3 (FUNCTION_DECL_CHECK (NODE))
 357
 358 /* Nonzero in a DECL if it is made for a pointer that points to something which
 359    is readonly.  Used mostly for fat pointers.  */
 360 #define DECL_POINTS_TO_READONLY_P(NODE) DECL_LANG_FLAG_4 (NODE)
 361
 362 /* Nonzero in a PARM_DECL if we are to pass by descriptor.  */
 363 #define DECL_BY_DESCRIPTOR_P(NODE) DECL_LANG_FLAG_5 (PARM_DECL_CHECK (NODE))
 364
 365 /* Nonzero in a VAR_DECL if it is a pointer renaming a global object.  */
 366 #define DECL_RENAMING_GLOBAL_P(NODE) DECL_LANG_FLAG_5 (VAR_DECL_CHECK (NODE))
 367
 368 /* In a FIELD_DECL corresponding to a discriminant, contains the
 369    discriminant number.  */
 370 #define DECL_DISCRIMINANT_NUMBER(NODE) DECL_INITIAL (FIELD_DECL_CHECK (NODE))
 371
 372 /* In a CONST_DECL, points to a VAR_DECL that is allocatable to
 373    memory.  Used when a scalar constant is aliased or has its
 374    address taken.  */
 375 #define DECL_CONST_CORRESPONDING_VAR(NODE) \
 376   GET_DECL_LANG_SPECIFIC (CONST_DECL_CHECK (NODE))
 377 #define SET_DECL_CONST_CORRESPONDING_VAR(NODE, X) \
 378   SET_DECL_LANG_SPECIFIC (CONST_DECL_CHECK (NODE), X)
 379
 380 /* In a FIELD_DECL, points to the FIELD_DECL that was the ultimate
 381    source of the decl.  */
 382 #define DECL_ORIGINAL_FIELD(NODE) \
 383   GET_DECL_LANG_SPECIFIC (FIELD_DECL_CHECK (NODE))
 384 #define SET_DECL_ORIGINAL_FIELD(NODE, X) \
 385   SET_DECL_LANG_SPECIFIC (FIELD_DECL_CHECK (NODE), X)
 386
 387 /* Set DECL_ORIGINAL_FIELD of FIELD1 to (that of) FIELD2.  */
 388 #define SET_DECL_ORIGINAL_FIELD_TO_FIELD(FIELD1, FIELD2)        \
 389   SET_DECL_ORIGINAL_FIELD ((FIELD1),                            \
 390                            DECL_ORIGINAL_FIELD (FIELD2)         \
 391                            ? DECL_ORIGINAL_FIELD (FIELD2) : (FIELD2))
 392
 393 /* Return true if FIELD1 and FIELD2 represent the same field.  */
 394 #define SAME_FIELD_P(FIELD1, FIELD2)                                    \
 395   ((FIELD1) == (FIELD2)                                                 \
 396    || DECL_ORIGINAL_FIELD (FIELD1) == (FIELD2)                          \
 397    || (FIELD1) == DECL_ORIGINAL_FIELD (FIELD2)                          \
 398    || (DECL_ORIGINAL_FIELD (FIELD1)                                     \
 399        && (DECL_ORIGINAL_FIELD (FIELD1) == DECL_ORIGINAL_FIELD (FIELD2))))
 400
 401 /* In a VAR_DECL, points to the object being renamed if the VAR_DECL is a
 402    renaming pointer, otherwise 0.  Note that this object is guaranteed to
 403    be protected against multiple evaluations.  */
 404 #define DECL_RENAMED_OBJECT(NODE) \
 405   GET_DECL_LANG_SPECIFIC (VAR_DECL_CHECK (NODE))
 406 #define SET_DECL_RENAMED_OBJECT(NODE, X) \
 407   SET_DECL_LANG_SPECIFIC (VAR_DECL_CHECK (NODE), X)
 408
 409 /* In a TYPE_DECL, points to the parallel type if any, otherwise 0.  */
 410 #define DECL_PARALLEL_TYPE(NODE) \
 411   GET_DECL_LANG_SPECIFIC (TYPE_DECL_CHECK (NODE))
 412 #define SET_DECL_PARALLEL_TYPE(NODE, X) \
 413   SET_DECL_LANG_SPECIFIC (TYPE_DECL_CHECK (NODE), X)
 414
 415 /* In a FUNCTION_DECL, points to the stub associated with the function
 416    if any, otherwise 0.  */
 417 #define DECL_FUNCTION_STUB(NODE) \
 418   GET_DECL_LANG_SPECIFIC (FUNCTION_DECL_CHECK (NODE))
 419 #define SET_DECL_FUNCTION_STUB(NODE, X) \
 420   SET_DECL_LANG_SPECIFIC (FUNCTION_DECL_CHECK (NODE), X)
 421
 422 /* In a PARM_DECL, points to the alternate TREE_TYPE.  */
 423 #define DECL_PARM_ALT_TYPE(NODE) \
 424   GET_DECL_LANG_SPECIFIC (PARM_DECL_CHECK (NODE))
 425 #define SET_DECL_PARM_ALT_TYPE(NODE, X) \
 426   SET_DECL_LANG_SPECIFIC (PARM_DECL_CHECK (NODE), X)
 427
 428
 429 /* Flags added to ref nodes.  */
 430
 431 /* Nonzero means this node will not trap.  */
 432 #undef TREE_THIS_NOTRAP
 433 #define TREE_THIS_NOTRAP(NODE) \
 434   (TREE_CHECK4 (NODE, INDIRECT_REF, ARRAY_REF, UNCONSTRAINED_ARRAY_REF, \
 435                 ARRAY_RANGE_REF)->base.nothrow_flag)
 436
 437
 438 /* Fields and macros for statements.  */
 439 #define IS_ADA_STMT(NODE) \
 440   (STATEMENT_CLASS_P (NODE) && TREE_CODE (NODE) >= STMT_STMT)
 441
 442 #define STMT_STMT_STMT(NODE)     TREE_OPERAND_CHECK_CODE (NODE, STMT_STMT, 0)
 443
 444 #define LOOP_STMT_COND(NODE)     TREE_OPERAND_CHECK_CODE (NODE, LOOP_STMT, 0)
 445 #define LOOP_STMT_UPDATE(NODE)   TREE_OPERAND_CHECK_CODE (NODE, LOOP_STMT, 1)
 446 #define LOOP_STMT_BODY(NODE)     TREE_OPERAND_CHECK_CODE (NODE, LOOP_STMT, 2)
 447 #define LOOP_STMT_LABEL(NODE)    TREE_OPERAND_CHECK_CODE (NODE, LOOP_STMT, 3)
 448
 449 /* A loop statement is conceptually made up of 6 sub-statements:
 450
 451     loop:
 452       TOP_CONDITION
 453       TOP_UPDATE
 454       BODY
 455       BOTTOM_CONDITION
 456       BOTTOM_UPDATE
 457       GOTO loop
 458
 459   However, only 4 of them can exist for a given loop, the pair of conditions
 460   and the pair of updates being mutually exclusive.  The default setting is
 461   TOP_CONDITION and BOTTOM_UPDATE and the following couple of flags are used
 462   to toggle the individual settings.  */
 463 #define LOOP_STMT_BOTTOM_COND_P(NODE) TREE_LANG_FLAG_0 (LOOP_STMT_CHECK (NODE))
 464 #define LOOP_STMT_TOP_UPDATE_P(NODE)  TREE_LANG_FLAG_1 (LOOP_STMT_CHECK (NODE))
 465
 466 #define EXIT_STMT_COND(NODE)     TREE_OPERAND_CHECK_CODE (NODE, EXIT_STMT, 0)
 467 #define EXIT_STMT_LABEL(NODE)    TREE_OPERAND_CHECK_CODE (NODE, EXIT_STMT, 1)