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) 1992-2023, 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 struct GTY(()) lang_type { tree t1; tree t2; };
  37 struct GTY(()) lang_decl { tree t; };
  38
  39 extern struct lang_type *get_lang_specific (tree node);
  40
  41 /* Macros to get and set the trees in TYPE_LANG_SPECIFIC.  */
  42 #define GET_TYPE_LANG_SPECIFIC(NODE) \
  43   (TYPE_LANG_SPECIFIC (NODE) ? TYPE_LANG_SPECIFIC (NODE)->t1 : NULL_TREE)
  44
  45 #define SET_TYPE_LANG_SPECIFIC(NODE, X) (get_lang_specific (NODE)->t1 = (X))
  46
  47 #define GET_TYPE_LANG_SPECIFIC2(NODE) \
  48   (TYPE_LANG_SPECIFIC (NODE) ? TYPE_LANG_SPECIFIC (NODE)->t2 : NULL_TREE)
  49
  50 #define SET_TYPE_LANG_SPECIFIC2(NODE, X) (get_lang_specific (NODE)->t2 = (X))
  51
  52 /* Macros to get and set the tree in DECL_LANG_SPECIFIC.  */
  53 #define GET_DECL_LANG_SPECIFIC(NODE) \
  54   (DECL_LANG_SPECIFIC (NODE) ? DECL_LANG_SPECIFIC (NODE)->t : NULL_TREE)
  55
  56 #define SET_DECL_LANG_SPECIFIC(NODE, X)                  \
  57 do {                                                     \
  58   tree tmp = (X);                                        \
  59   if (!DECL_LANG_SPECIFIC (NODE))                        \
  60     DECL_LANG_SPECIFIC (NODE)                            \
  61       = ggc_alloc<struct lang_decl> (); \
  62   DECL_LANG_SPECIFIC (NODE)->t = tmp;                    \
  63 } while (0)
  64
  65
  66 /* Flags added to type nodes.  */
  67
  68 /* For RECORD_TYPE, UNION_TYPE, and QUAL_UNION_TYPE, nonzero if this is a
  69    record being used as a fat pointer (only true for RECORD_TYPE).  */
  70 #define TYPE_FAT_POINTER_P(NODE) \
  71   TYPE_LANG_FLAG_0 (RECORD_OR_UNION_CHECK (NODE))
  72
  73 #define TYPE_IS_FAT_POINTER_P(NODE) \
  74   (TREE_CODE (NODE) == RECORD_TYPE && TYPE_FAT_POINTER_P (NODE))
  75
  76 /* For integral types and array types, nonzero if this is an implementation
  77    type for a bit-packed array type.  Such types should not be extended to a
  78    larger size or validated against a specified size.  */
  79 #define TYPE_BIT_PACKED_ARRAY_TYPE_P(NODE) \
  80   TYPE_LANG_FLAG_0 (TREE_CHECK2 (NODE, INTEGER_TYPE, ARRAY_TYPE))
  81
  82 #define BIT_PACKED_ARRAY_TYPE_P(NODE) \
  83   ((TREE_CODE (NODE) == INTEGER_TYPE || TREE_CODE (NODE) == ARRAY_TYPE) \
  84    && TYPE_BIT_PACKED_ARRAY_TYPE_P (NODE))
  85
  86 /* For FUNCTION_TYPE and METHOD_TYPE, nonzero if the function returns by
  87    direct reference, i.e. the callee returns a pointer to a memory location
  88    it has allocated and the caller only needs to dereference the pointer.  */
  89 #define TYPE_RETURN_BY_DIRECT_REF_P(NODE) \
  90   TYPE_LANG_FLAG_0 (FUNC_OR_METHOD_CHECK (NODE))
  91
  92 /* For INTEGER_TYPE, nonzero if this is a modular type with a modulus that
  93    is not equal to two to the power of its mode's size.  */
  94 #define TYPE_MODULAR_P(NODE) TYPE_LANG_FLAG_1 (INTEGER_TYPE_CHECK (NODE))
  95
  96 /* For ARRAY_TYPE, nonzero if this type corresponds to a dimension of
  97    an Ada array other than the first.  */
  98 #define TYPE_MULTI_ARRAY_P(NODE) TYPE_LANG_FLAG_1 (ARRAY_TYPE_CHECK (NODE))
  99
 100 /* For RECORD_TYPE, UNION_TYPE, and QUAL_UNION_TYPE, nonzero if this denotes
 101    a justified modular type (will only be true for RECORD_TYPE).  */
 102 #define TYPE_JUSTIFIED_MODULAR_P(NODE) \
 103   TYPE_LANG_FLAG_1 (RECORD_OR_UNION_CHECK (NODE))
 104
 105 /* Nonzero in an arithmetic subtype if this is a subtype not known to the
 106    front-end.  */
 107 #define TYPE_EXTRA_SUBTYPE_P(NODE) TYPE_LANG_FLAG_2 (INTEGER_TYPE_CHECK (NODE))
 108
 109 #define TYPE_IS_EXTRA_SUBTYPE_P(NODE) \
 110   (TREE_CODE (NODE) == INTEGER_TYPE && TYPE_EXTRA_SUBTYPE_P (NODE))
 111
 112 /* Nonzero for an aggregate type if this is a by-reference type.  We also
 113    set this on an ENUMERAL_TYPE that is dummy.  */
 114 #define TYPE_BY_REFERENCE_P(NODE)                                      \
 115   TYPE_LANG_FLAG_2 (TREE_CHECK5 (NODE, RECORD_TYPE, UNION_TYPE,        \
 116                                  ARRAY_TYPE, UNCONSTRAINED_ARRAY_TYPE, \
 117                                  ENUMERAL_TYPE))
 118
 119 #define TYPE_IS_BY_REFERENCE_P(NODE)                \
 120   ((TREE_CODE (NODE) == RECORD_TYPE                 \
 121     || TREE_CODE (NODE) == UNION_TYPE               \
 122     || TREE_CODE (NODE) == ARRAY_TYPE               \
 123     || TREE_CODE (NODE) == UNCONSTRAINED_ARRAY_TYPE \
 124     || TREE_CODE (NODE) == ENUMERAL_TYPE)           \
 125    && TYPE_BY_REFERENCE_P (NODE))
 126
 127 /* For RECORD_TYPE, UNION_TYPE, and QUAL_UNION_TYPE, nonzero if this is the
 128    type for an object whose type includes its template in addition to
 129    its value (only true for RECORD_TYPE).  */
 130 #define TYPE_CONTAINS_TEMPLATE_P(NODE) \
 131   TYPE_LANG_FLAG_3 (RECORD_OR_UNION_CHECK (NODE))
 132
 133 /* For INTEGER_TYPE, nonzero if it implements a fixed-point type.  */
 134 #define TYPE_FIXED_POINT_P(NODE) \
 135   TYPE_LANG_FLAG_3 (INTEGER_TYPE_CHECK (NODE))
 136
 137 #define TYPE_IS_FIXED_POINT_P(NODE) \
 138   (TREE_CODE (NODE) == INTEGER_TYPE && TYPE_FIXED_POINT_P (NODE))
 139
 140 /* True if NODE is a thin pointer.  */
 141 #define TYPE_IS_THIN_POINTER_P(NODE)                    \
 142   (POINTER_TYPE_P (NODE)                                \
 143    && TREE_CODE (TREE_TYPE (NODE)) == RECORD_TYPE       \
 144    && TYPE_CONTAINS_TEMPLATE_P (TREE_TYPE (NODE)))
 145
 146 /* True if TYPE is either a fat or thin pointer to an unconstrained
 147    array.  */
 148 #define TYPE_IS_FAT_OR_THIN_POINTER_P(NODE) \
 149   (TYPE_IS_FAT_POINTER_P (NODE) || TYPE_IS_THIN_POINTER_P (NODE))
 150
 151 /* For INTEGER_TYPEs, nonzero if the type has a biased representation.  */
 152 #define TYPE_BIASED_REPRESENTATION_P(NODE) \
 153   TYPE_LANG_FLAG_4 (INTEGER_TYPE_CHECK (NODE))
 154
 155 /* For ARRAY_TYPEs, nonzero if the array type has Convention_Fortran.  */
 156 #define TYPE_CONVENTION_FORTRAN_P(NODE) \
 157   TYPE_LANG_FLAG_4 (ARRAY_TYPE_CHECK (NODE))
 158
 159 /* For RECORD_TYPE, UNION_TYPE and ENUMERAL_TYPE, nonzero if this is a dummy
 160    type, made to correspond to a private or incomplete type.  */
 161 #define TYPE_DUMMY_P(NODE) \
 162   TYPE_LANG_FLAG_4 (TREE_CHECK3 (NODE, RECORD_TYPE, UNION_TYPE, ENUMERAL_TYPE))
 163
 164 #define TYPE_IS_DUMMY_P(NODE)             \
 165   ((TREE_CODE (NODE) == RECORD_TYPE       \
 166     || TREE_CODE (NODE) == UNION_TYPE     \
 167     || TREE_CODE (NODE) == ENUMERAL_TYPE) \
 168    && TYPE_DUMMY_P (NODE))
 169
 170 /* For an INTEGER_TYPE, nonzero if TYPE_ACTUAL_BOUNDS is present.  */
 171 #define TYPE_HAS_ACTUAL_BOUNDS_P(NODE) \
 172   TYPE_LANG_FLAG_5 (INTEGER_TYPE_CHECK (NODE))
 173
 174 /* For a RECORD_TYPE, nonzero if this was made just to supply needed
 175    padding or alignment.  */
 176 #define TYPE_PADDING_P(NODE) TYPE_LANG_FLAG_5 (RECORD_TYPE_CHECK (NODE))
 177
 178 #define TYPE_IS_PADDING_P(NODE) \
 179   (TREE_CODE (NODE) == RECORD_TYPE && TYPE_PADDING_P (NODE))
 180
 181 /* True for a non-dummy type if TYPE can alias any other types.  */
 182 #define TYPE_UNIVERSAL_ALIASING_P(NODE) TYPE_LANG_FLAG_6 (NODE)
 183
 184 /* True for a dummy type if TYPE appears in a profile.  */
 185 #define TYPE_DUMMY_IN_PROFILE_P(NODE) TYPE_LANG_FLAG_6 (NODE)
 186
 187 /* True if objects of this type are guaranteed to be properly aligned.  */
 188 #define TYPE_ALIGN_OK(NODE) TYPE_LANG_FLAG_7 (NODE)
 189
 190 /* True for types that implement a packed array and for original packed array
 191    types.  */
 192 #define TYPE_IMPL_PACKED_ARRAY_P(NODE) \
 193   ((TREE_CODE (NODE) == ARRAY_TYPE && TYPE_PACKED (NODE)) \
 194    || (TREE_CODE (NODE) == INTEGER_TYPE && TYPE_BIT_PACKED_ARRAY_TYPE_P (NODE)))
 195
 196 /* True for types that can hold a debug type.  */
 197 #define TYPE_CAN_HAVE_DEBUG_TYPE_P(NODE) (!TYPE_IMPL_PACKED_ARRAY_P (NODE))
 198
 199 /* For RECORD_TYPE, UNION_TYPE, and QUAL_UNION_TYPE, this holds the maximum
 200    alignment value the type ought to have.  */
 201 #define TYPE_MAX_ALIGN(NODE) (TYPE_PRECISION (RECORD_OR_UNION_CHECK (NODE)))
 202
 203 /* For an UNCONSTRAINED_ARRAY_TYPE, this is the record containing both the
 204    template and the object.
 205
 206    ??? We also put this on an ENUMERAL_TYPE that is dummy.  Technically,
 207    this is a conflict on the minval field, but there doesn't seem to be
 208    simple fix, so we'll live with this kludge for now.  */
 209 #define TYPE_OBJECT_RECORD_TYPE(NODE) \
 210   (TYPE_MIN_VALUE_RAW (TREE_CHECK2 ((NODE), UNCONSTRAINED_ARRAY_TYPE, \
 211                                     ENUMERAL_TYPE)))
 212
 213 /* For numerical types, this is the GCC lower bound of the type.  The GCC
 214    type system is based on the invariant that an object X of a given type
 215    cannot hold at run time a value smaller than its lower bound; otherwise
 216    the behavior is undefined.  The optimizer takes advantage of this and
 217    considers that the assertion X >= LB is always true.  */
 218 #define TYPE_GCC_MIN_VALUE(NODE) \
 219   (TYPE_MIN_VALUE_RAW (NUMERICAL_TYPE_CHECK (NODE)))
 220
 221 /* For numerical types, this is the GCC upper bound of the type.  The GCC
 222    type system is based on the invariant that an object X of a given type
 223    cannot hold at run time a value larger than its upper bound; otherwise
 224    the behavior is undefined.  The optimizer takes advantage of this and
 225    considers that the assertion X <= UB is always true.  */
 226 #define TYPE_GCC_MAX_VALUE(NODE) \
 227   (TYPE_MAX_VALUE_RAW (NUMERICAL_TYPE_CHECK (NODE)))
 228
 229 /* For a FUNCTION_TYPE and METHOD_TYPE, if the function has parameters passed
 230    by copy in/copy out, this is the list of nodes used to specify the return
 231    values of these parameters.  For a full description of the copy in/copy out
 232    parameter passing mechanism refer to the routine gnat_to_gnu_entity.  */
 233 #define TYPE_CI_CO_LIST(NODE) TYPE_LANG_SLOT_1 (FUNC_OR_METHOD_CHECK (NODE))
 234
 235 /* For an ARRAY_TYPE with variable size, this is the padding type built for
 236    the array type when it is itself the component type of another array.  */
 237 #define TYPE_PADDING_FOR_COMPONENT(NODE) \
 238   TYPE_LANG_SLOT_1 (ARRAY_TYPE_CHECK (NODE))
 239
 240 /* For a VECTOR_TYPE, this is the representative array type.  */
 241 #define TYPE_REPRESENTATIVE_ARRAY(NODE) \
 242   TYPE_LANG_SLOT_1 (VECTOR_TYPE_CHECK (NODE))
 243
 244 /* For numerical types, this holds various RM-defined values.  */
 245 #define TYPE_RM_VALUES(NODE) TYPE_LANG_SLOT_1 (NUMERICAL_TYPE_CHECK (NODE))
 246
 247 /* Macros to get and set the individual values in TYPE_RM_VALUES.  */
 248 #define TYPE_RM_VALUE(NODE, N)                              \
 249   (TYPE_RM_VALUES (NODE)                                    \
 250    ? TREE_VEC_ELT (TYPE_RM_VALUES (NODE), (N)) : NULL_TREE)
 251
 252 #define SET_TYPE_RM_VALUE(NODE, N, X)              \
 253 do {                                               \
 254   tree tmp = (X);                                  \
 255   if (!TYPE_RM_VALUES (NODE))                      \
 256     TYPE_RM_VALUES (NODE) = make_tree_vec (3);     \
 257   /* ??? The field is not visited by the generic   \
 258      code so we need to mark it manually.  */      \
 259   MARK_VISITED (tmp);                              \
 260   TREE_VEC_ELT (TYPE_RM_VALUES (NODE), (N)) = tmp; \
 261 } while (0)
 262
 263 /* For numerical types, this is the RM size of the type, aka its precision.
 264    There is a discrepancy between what is called precision here (and more
 265    generally throughout gigi) and what is called precision in the GCC type
 266    system: in the former case it's TYPE_RM_SIZE whereas it's TYPE_PRECISION
 267    in the latter case.  They are not identical because of the need to support
 268    invalid values.
 269
 270    These values can be outside the range of values allowed by the RM size
 271    but they must nevertheless be valid in the GCC type system, otherwise
 272    the optimizer can pretend that they simply don't exist.  Therefore they
 273    must be within the range of values allowed by the precision in the GCC
 274    sense, hence TYPE_PRECISION be set to the Esize, not the RM size.  */
 275 #define TYPE_RM_SIZE(NODE) TYPE_RM_VALUE ((NODE), 0)
 276 #define SET_TYPE_RM_SIZE(NODE, X) SET_TYPE_RM_VALUE ((NODE), 0, (X))
 277
 278 /* For numerical types, this is the RM lower bound of the type.  There is
 279    again a discrepancy between this lower bound and the GCC lower bound,
 280    again because of the need to support invalid values.
 281
 282    These values can be outside the range of values allowed by the RM lower
 283    bound but they must nevertheless be valid in the GCC type system, otherwise
 284    the optimizer can pretend that they simply don't exist.  Therefore they
 285    must be within the range of values allowed by the lower bound in the GCC
 286    sense, hence the GCC lower bound be set to that of the base type.
 287
 288    This lower bound is translated directly without the adjustments that may
 289    be required for type compatibility, so it will generally be necessary to
 290    convert it to the base type of the numerical type before using it.  */
 291 #define TYPE_RM_MIN_VALUE(NODE) TYPE_RM_VALUE ((NODE), 1)
 292 #define SET_TYPE_RM_MIN_VALUE(NODE, X) SET_TYPE_RM_VALUE ((NODE), 1, (X))
 293
 294 /* For numerical types, this is the RM upper bound of the type.  There is
 295    again a discrepancy between this upper bound and the GCC upper bound,
 296    again because of the need to support invalid values.
 297
 298    These values can be outside the range of values allowed by the RM upper
 299    bound but they must nevertheless be valid in the GCC type system, otherwise
 300    the optimizer can pretend that they simply don't exist.  Therefore they
 301    must be within the range of values allowed by the upper bound in the GCC
 302    sense, hence the GCC upper bound be set to that of the base type.
 303
 304    This upper bound is translated directly without the adjustments that may
 305    be required for type compatibility, so it will generally be necessary to
 306    convert it to the base type of the numerical type before using it.  */
 307 #define TYPE_RM_MAX_VALUE(NODE) TYPE_RM_VALUE ((NODE), 2)
 308 #define SET_TYPE_RM_MAX_VALUE(NODE, X) SET_TYPE_RM_VALUE ((NODE), 2, (X))
 309
 310 /* For numerical types, this is the lower bound of the type, i.e. the RM lower
 311    bound for language-defined types and the GCC lower bound for others.  */
 312 #undef TYPE_MIN_VALUE
 313 #define TYPE_MIN_VALUE(NODE) \
 314   (TYPE_RM_MIN_VALUE (NODE) \
 315    ? TYPE_RM_MIN_VALUE (NODE) : TYPE_GCC_MIN_VALUE (NODE))
 316
 317 /* For numerical types, this is the upper bound of the type, i.e. the RM upper
 318    bound for language-defined types and the GCC upper bound for others.  */
 319 #undef TYPE_MAX_VALUE
 320 #define TYPE_MAX_VALUE(NODE) \
 321   (TYPE_RM_MAX_VALUE (NODE) \
 322    ? TYPE_RM_MAX_VALUE (NODE) : TYPE_GCC_MAX_VALUE (NODE))
 323
 324 /* For an INTEGER_TYPE with TYPE_MODULAR_P, this is the value of the
 325    modulus. */
 326 #define TYPE_MODULUS(NODE) \
 327   GET_TYPE_LANG_SPECIFIC (INTEGER_TYPE_CHECK (NODE))
 328 #define SET_TYPE_MODULUS(NODE, X) \
 329   SET_TYPE_LANG_SPECIFIC (INTEGER_TYPE_CHECK (NODE), X)
 330
 331 /* For an INTEGER_TYPE that is the TYPE_DOMAIN of some ARRAY_TYPE, this is
 332    the type corresponding to the Ada index type.  It is necessary to keep
 333    these 2 views for every array type because the TYPE_DOMAIN is subject
 334    to strong constraints in GENERIC: it must be a subtype of SIZETYPE and
 335    may not be superflat, i.e. the upper bound must always be larger or
 336    equal to the lower bound minus 1 (i.e. the canonical length formula
 337    must always yield a non-negative number), which means that at least
 338    one of the bounds may need to be a conditional expression.  There are
 339    no such constraints on the TYPE_INDEX_TYPE because gigi is prepared to
 340    deal with the superflat case; moreover the TYPE_INDEX_TYPE is used as
 341    the index type for the debug info and, therefore, needs to be as close
 342    as possible to the source index type.  */
 343 #define TYPE_INDEX_TYPE(NODE) \
 344   GET_TYPE_LANG_SPECIFIC (INTEGER_TYPE_CHECK (NODE))
 345 #define SET_TYPE_INDEX_TYPE(NODE, X) \
 346   SET_TYPE_LANG_SPECIFIC (INTEGER_TYPE_CHECK (NODE), X)
 347
 348 /* For an INTEGER_TYPE with TYPE_HAS_ACTUAL_BOUNDS_P or an ARRAY_TYPE, this is
 349    the index type that should be used when the actual bounds are required for
 350    a template.  This is used in the case of packed arrays.  */
 351 #define TYPE_ACTUAL_BOUNDS(NODE) \
 352   GET_TYPE_LANG_SPECIFIC (TREE_CHECK2 (NODE, INTEGER_TYPE, ARRAY_TYPE))
 353 #define SET_TYPE_ACTUAL_BOUNDS(NODE, X) \
 354   SET_TYPE_LANG_SPECIFIC (TREE_CHECK2 (NODE, INTEGER_TYPE, ARRAY_TYPE), X)
 355
 356 /* For a POINTER_TYPE that points to the template type of an unconstrained
 357    array type, this is the address to be used in a null fat pointer.  */
 358 #define TYPE_NULL_BOUNDS(NODE) \
 359   GET_TYPE_LANG_SPECIFIC (POINTER_TYPE_CHECK (NODE))
 360 #define SET_TYPE_NULL_BOUNDS(NODE, X) \
 361   SET_TYPE_LANG_SPECIFIC (POINTER_TYPE_CHECK (NODE), X)
 362
 363 /* For a RECORD_TYPE that is a fat pointer, this is the type for the
 364    unconstrained array.  Likewise for a RECORD_TYPE that is pointed
 365    to by a thin pointer, if it is made for the unconstrained array
 366    type itself; the field is NULL_TREE if the RECORD_TYPE is made
 367    for a constrained subtype of the array type.  */
 368 #define TYPE_UNCONSTRAINED_ARRAY(NODE) \
 369   GET_TYPE_LANG_SPECIFIC (RECORD_TYPE_CHECK (NODE))
 370 #define SET_TYPE_UNCONSTRAINED_ARRAY(NODE, X) \
 371   SET_TYPE_LANG_SPECIFIC (RECORD_TYPE_CHECK (NODE), X)
 372
 373 /* For other RECORD_TYPEs and all UNION_TYPEs and QUAL_UNION_TYPEs, this is
 374    the Ada size of the object.  This differs from the GCC size in that it
 375    does not include any rounding up to the alignment of the type.  */
 376 #define TYPE_ADA_SIZE(NODE) \
 377   GET_TYPE_LANG_SPECIFIC (RECORD_OR_UNION_CHECK (NODE))
 378 #define SET_TYPE_ADA_SIZE(NODE, X) \
 379   SET_TYPE_LANG_SPECIFIC (RECORD_OR_UNION_CHECK (NODE), X)
 380
 381 /* For an INTEGER_TYPE with TYPE_IS_FIXED_POINT_P, this is the value of the
 382    scale factor.  Modular types, index types (sizetype subtypes) and
 383    fixed-point types are totally distinct types, so there is no problem with
 384    sharing type lang specific's first slot.  */
 385 #define TYPE_SCALE_FACTOR(NODE) \
 386   GET_TYPE_LANG_SPECIFIC (INTEGER_TYPE_CHECK (NODE))
 387 #define SET_TYPE_SCALE_FACTOR(NODE, X) \
 388   SET_TYPE_LANG_SPECIFIC (INTEGER_TYPE_CHECK (NODE), X)
 389
 390 /* For types with TYPE_CAN_HAVE_DEBUG_TYPE_P, this is the type to use in
 391    debugging information.  */
 392 #define TYPE_DEBUG_TYPE(NODE) \
 393   GET_TYPE_LANG_SPECIFIC2 (NODE)
 394 #define SET_TYPE_DEBUG_TYPE(NODE, X) \
 395   SET_TYPE_LANG_SPECIFIC2 (NODE, X)
 396
 397 /* For types with TYPE_IMPL_PACKED_ARRAY_P, this is the original packed
 398    array type.  Note that this predicate is true for original packed array
 399    types, so these cannot have a debug type.  */
 400 #define TYPE_ORIGINAL_PACKED_ARRAY(NODE) \
 401   GET_TYPE_LANG_SPECIFIC2 (NODE)
 402 #define SET_TYPE_ORIGINAL_PACKED_ARRAY(NODE, X) \
 403   SET_TYPE_LANG_SPECIFIC2 (NODE, X)
 404
 405
 406 /* Flags added to decl nodes.  */
 407
 408 /* Nonzero in a VAR_DECL if it is guaranteed to be constant after having
 409    been elaborated and TREE_READONLY is not set on it.  */
 410 #define DECL_READONLY_ONCE_ELAB(NODE) DECL_LANG_FLAG_0 (VAR_DECL_CHECK (NODE))
 411
 412 /* Nonzero in a CONST_DECL if its value is (essentially) the address of a
 413    constant CONSTRUCTOR.  */
 414 #define DECL_CONST_ADDRESS_P(NODE) DECL_LANG_FLAG_0 (CONST_DECL_CHECK (NODE))
 415
 416 /* Nonzero in a FIELD_DECL if it is declared as aliased.  */
 417 #define DECL_ALIASED_P(NODE) DECL_LANG_FLAG_0 (FIELD_DECL_CHECK (NODE))
 418
 419 /* Nonzero in a TYPE_DECL if this is the declaration of a Taft amendment type
 420    in the main unit, i.e. the full declaration is available.  */
 421 #define DECL_TAFT_TYPE_P(NODE) DECL_LANG_FLAG_0 (TYPE_DECL_CHECK (NODE))
 422
 423 /* Nonzero in a PARM_DECL passed by reference but for which only a restricted
 424    form of aliasing is allowed.  The first restriction comes explicitly from
 425    the RM 6.2(12) clause: there is no read-after-write dependency between a
 426    store based on such a PARM_DECL and a load not based on this PARM_DECL,
 427    so stores based on such PARM_DECLs can be sunk past all loads based on
 428    a distinct object.  The second restriction can be inferred from the same
 429    clause: there is no write-after-write dependency between a store based
 430    on such a PARM_DECL and a store based on a distinct such PARM_DECL, as
 431    the compiler would be allowed to pass the parameters by copy and the
 432    order of assignment to actual parameters after a call is arbitrary as
 433    per the RM 6.4.1(17) clause, so stores based on distinct such PARM_DECLs
 434    can be swapped.  */
 435 #define DECL_RESTRICTED_ALIASING_P(NODE) \
 436   DECL_LANG_FLAG_0 (PARM_DECL_CHECK (NODE))
 437
 438 /* Nonzero in a DECL if it is always used by reference, i.e. an INDIRECT_REF
 439    is needed to access the object.  */
 440 #define DECL_BY_REF_P(NODE) DECL_LANG_FLAG_1 (NODE)
 441
 442 /* Nonzero in a DECL if it is made for a pointer that can never be null.  */
 443 #define DECL_CAN_NEVER_BE_NULL_P(NODE) DECL_LANG_FLAG_2 (NODE)
 444
 445 /* Nonzero in a VAR_DECL if it is made for a loop parameter.  */
 446 #define DECL_LOOP_PARM_P(NODE) DECL_LANG_FLAG_3 (VAR_DECL_CHECK (NODE))
 447
 448 /* Nonzero in a FIELD_DECL that is a dummy built for some internal reason.  */
 449 #define DECL_INTERNAL_P(NODE) DECL_LANG_FLAG_3 (FIELD_DECL_CHECK (NODE))
 450
 451 /* Nonzero in a PARM_DECL if it is made for an Ada array being passed to a
 452    foreign convention subprogram.  */
 453 #define DECL_BY_COMPONENT_PTR_P(NODE) DECL_LANG_FLAG_3 (PARM_DECL_CHECK (NODE))
 454
 455 /* Nonzero in a FUNCTION_DECL that corresponds to an elaboration procedure.  */
 456 #define DECL_ELABORATION_PROC_P(NODE) \
 457   DECL_LANG_FLAG_3 (FUNCTION_DECL_CHECK (NODE))
 458
 459 /* Nonzero in a CONST_DECL, VAR_DECL or PARM_DECL if it is made for a pointer
 460    that points to something which is readonly.  */
 461 #define DECL_POINTS_TO_READONLY_P(NODE) DECL_LANG_FLAG_4 (NODE)
 462
 463 /* Nonzero in a FIELD_DECL if it is invariant once set, for example if it is
 464    a discriminant of a discriminated type without default expression.  */
 465 #define DECL_INVARIANT_P(NODE) DECL_LANG_FLAG_4 (FIELD_DECL_CHECK (NODE))
 466
 467 /* Nonzero in a FUNCTION_DECL if this is a definition, i.e. if it was created
 468    by a call to gnat_to_gnu_entity with definition set to True.  */
 469 #define DECL_FUNCTION_IS_DEF(NODE) \
 470   DECL_LANG_FLAG_4 (FUNCTION_DECL_CHECK (NODE))
 471
 472 /* Nonzero in a VAR_DECL if it is a temporary created to hold the return
 473    value of a function call or 'reference to a function call.  */
 474 #define DECL_RETURN_VALUE_P(NODE) DECL_LANG_FLAG_5 (VAR_DECL_CHECK (NODE))
 475
 476 /* Nonzero in a PARM_DECL if its mechanism was forced to by-reference.  */
 477 #define DECL_FORCED_BY_REF_P(NODE) DECL_LANG_FLAG_5 (PARM_DECL_CHECK (NODE))
 478
 479 /* In a FIELD_DECL corresponding to a discriminant, contains the
 480    discriminant number.  */
 481 #define DECL_DISCRIMINANT_NUMBER(NODE) DECL_INITIAL (FIELD_DECL_CHECK (NODE))
 482
 483 /* In a CONST_DECL, points to a VAR_DECL that is allocatable to
 484    memory.  Used when a scalar constant is aliased or has its
 485    address taken.  */
 486 #define DECL_CONST_CORRESPONDING_VAR(NODE) \
 487   GET_DECL_LANG_SPECIFIC (CONST_DECL_CHECK (NODE))
 488 #define SET_DECL_CONST_CORRESPONDING_VAR(NODE, X) \
 489   SET_DECL_LANG_SPECIFIC (CONST_DECL_CHECK (NODE), X)
 490
 491 /* In a FIELD_DECL, points to the FIELD_DECL that was the ultimate
 492    source of the decl.  */
 493 #define DECL_ORIGINAL_FIELD(NODE) \
 494   GET_DECL_LANG_SPECIFIC (FIELD_DECL_CHECK (NODE))
 495 #define SET_DECL_ORIGINAL_FIELD(NODE, X) \
 496   SET_DECL_LANG_SPECIFIC (FIELD_DECL_CHECK (NODE), X)
 497
 498 /* Set DECL_ORIGINAL_FIELD of FIELD1 to (that of) FIELD2.  */
 499 #define SET_DECL_ORIGINAL_FIELD_TO_FIELD(FIELD1, FIELD2)        \
 500   SET_DECL_ORIGINAL_FIELD ((FIELD1),                            \
 501                            DECL_ORIGINAL_FIELD (FIELD2)         \
 502                            ? DECL_ORIGINAL_FIELD (FIELD2) : (FIELD2))
 503
 504 /* Return true if FIELD1 and FIELD2 represent the same field.  */
 505 #define SAME_FIELD_P(FIELD1, FIELD2)                                    \
 506   ((FIELD1) == (FIELD2)                                                 \
 507    || DECL_ORIGINAL_FIELD (FIELD1) == (FIELD2)                          \
 508    || (FIELD1) == DECL_ORIGINAL_FIELD (FIELD2)                          \
 509    || (DECL_ORIGINAL_FIELD (FIELD1)                                     \
 510        && (DECL_ORIGINAL_FIELD (FIELD1) == DECL_ORIGINAL_FIELD (FIELD2))))
 511
 512 /* In a VAR_DECL with the DECL_LOOP_PARM_P flag set, points to the special
 513    induction variable that is built under certain circumstances, if any.  */
 514 #define DECL_INDUCTION_VAR(NODE) \
 515   GET_DECL_LANG_SPECIFIC (VAR_DECL_CHECK (NODE))
 516 #define SET_DECL_INDUCTION_VAR(NODE, X) \
 517   SET_DECL_LANG_SPECIFIC (VAR_DECL_CHECK (NODE), X)
 518
 519 /* In a TYPE_DECL, points to the parallel type if any, otherwise 0.  */
 520 #define DECL_PARALLEL_TYPE(NODE) \
 521   GET_DECL_LANG_SPECIFIC (TYPE_DECL_CHECK (NODE))
 522 #define SET_DECL_PARALLEL_TYPE(NODE, X) \
 523   SET_DECL_LANG_SPECIFIC (TYPE_DECL_CHECK (NODE), X)
 524
 525
 526 /* Flags added to ref nodes.  */
 527
 528 /* Nonzero means this node will not trap.  */
 529 #undef TREE_THIS_NOTRAP
 530 #define TREE_THIS_NOTRAP(NODE) \
 531   (TREE_CHECK4 (NODE, INDIRECT_REF, ARRAY_REF, UNCONSTRAINED_ARRAY_REF, \
 532                 ARRAY_RANGE_REF)->base.nothrow_flag)
 533
 534
 535 /* Fields and macros for statements.  */
 536 #define IS_ADA_STMT(NODE) \
 537   (STATEMENT_CLASS_P (NODE) && TREE_CODE (NODE) >= STMT_STMT)
 538
 539 #define STMT_STMT_STMT(NODE)     TREE_OPERAND_CHECK_CODE (NODE, STMT_STMT, 0)
 540
 541 #define LOOP_STMT_COND(NODE)     TREE_OPERAND_CHECK_CODE (NODE, LOOP_STMT, 0)
 542 #define LOOP_STMT_UPDATE(NODE)   TREE_OPERAND_CHECK_CODE (NODE, LOOP_STMT, 1)
 543 #define LOOP_STMT_BODY(NODE)     TREE_OPERAND_CHECK_CODE (NODE, LOOP_STMT, 2)
 544 #define LOOP_STMT_LABEL(NODE)    TREE_OPERAND_CHECK_CODE (NODE, LOOP_STMT, 3)
 545
 546 /* A loop statement is conceptually made up of 6 sub-statements:
 547
 548     loop:
 549       TOP_CONDITION
 550       TOP_UPDATE
 551       BODY
 552       BOTTOM_CONDITION
 553       BOTTOM_UPDATE
 554       GOTO loop
 555
 556   However, only 4 of them can exist for a given loop, the pair of conditions
 557   and the pair of updates being mutually exclusive.  The default setting is
 558   TOP_CONDITION and BOTTOM_UPDATE and the following couple of flags are used
 559   to toggle the individual settings.  */
 560 #define LOOP_STMT_BOTTOM_COND_P(NODE) TREE_LANG_FLAG_0 (LOOP_STMT_CHECK (NODE))
 561 #define LOOP_STMT_TOP_UPDATE_P(NODE)  TREE_LANG_FLAG_1 (LOOP_STMT_CHECK (NODE))
 562
 563 /* Optimization hints on loops.  */
 564 #define LOOP_STMT_IVDEP(NODE)     TREE_LANG_FLAG_2 (LOOP_STMT_CHECK (NODE))
 565 #define LOOP_STMT_NO_UNROLL(NODE) TREE_LANG_FLAG_3 (LOOP_STMT_CHECK (NODE))
 566 #define LOOP_STMT_UNROLL(NODE)    TREE_LANG_FLAG_4 (LOOP_STMT_CHECK (NODE))
 567 #define LOOP_STMT_NO_VECTOR(NODE) TREE_LANG_FLAG_5 (LOOP_STMT_CHECK (NODE))
 568 #define LOOP_STMT_VECTOR(NODE)    TREE_LANG_FLAG_6 (LOOP_STMT_CHECK (NODE))
 569
 570 #define EXIT_STMT_COND(NODE)     TREE_OPERAND_CHECK_CODE (NODE, EXIT_STMT, 0)
 571 #define EXIT_STMT_LABEL(NODE)    TREE_OPERAND_CHECK_CODE (NODE, EXIT_STMT, 1)
 572
 573 /* Small kludge to be able to define Ada built-in functions locally.
 574    We overload them on top of the C++ coroutines builtin functions.  */
 575 #define BUILT_IN_LIKELY      BUILT_IN_CORO_PROMISE
 576 #define BUILT_IN_UNLIKELY    BUILT_IN_CORO_RESUME
 577 #define BUILT_IN_RETURN_SLOT BUILT_IN_CORO_DESTROY