| blob | 6207cb7605442ad840f19dd7bb26990ab727c3fc |
1 /****************************************************************************
2 * *
3 * GNAT COMPILER COMPONENTS *
4 * *
5 * D E C L *
6 * *
7 * C Implementation File *
8 * *
9 * $Revision$
10 * *
11 * Copyright (C) 1992-2001, Free Software Foundation, Inc. *
12 * *
13 * GNAT is free software; you can redistribute it and/or modify it under *
14 * terms of the GNU General Public License as published by the Free Soft- *
15 * ware Foundation; either version 2, or (at your option) any later ver- *
16 * sion. GNAT is distributed in the hope that it will be useful, but WITH- *
17 * OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY *
18 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License *
19 * for more details. You should have received a copy of the GNU General *
20 * Public License distributed with GNAT; see file COPYING. If not, write *
21 * to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, *
22 * MA 02111-1307, USA. *
23 * *
24 * GNAT was originally developed by the GNAT team at New York University. *
25 * It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). *
26 * *
27 ****************************************************************************/
54 /* Setting this to 1 suppresses hashing of types. */
57 /* Provide default values for the macros controlling stack checking.
58 This is copied from GCC's expr.h. */
60 #ifndef STACK_CHECK_BUILTIN
61 #define STACK_CHECK_BUILTIN 0
62 #endif
63 #ifndef STACK_CHECK_PROBE_INTERVAL
64 #define STACK_CHECK_PROBE_INTERVAL 4096
65 #endif
66 #ifndef STACK_CHECK_MAX_FRAME_SIZE
67 #define STACK_CHECK_MAX_FRAME_SIZE \
68 (STACK_CHECK_PROBE_INTERVAL - UNITS_PER_WORD)
69 #endif
70 #ifndef STACK_CHECK_MAX_VAR_SIZE
71 #define STACK_CHECK_MAX_VAR_SIZE (STACK_CHECK_MAX_FRAME_SIZE / 100)
72 #endif
74 /* These two variables are used to defer recursively expanding incomplete
75 types while we are processing a record or subprogram type. */
78 static struct incomplete
79 {
81 tree old_type;
82 Entity_Id full_type;
111 \f
112 /* Given GNAT_ENTITY, an entity in the incoming GNAT tree, return a
113 GCC type corresponding to that entity. GNAT_ENTITY is assumed to
114 refer to an Ada type. */
116 tree
118 Entity_Id gnat_entity;
119 {
120 tree gnu_decl;
122 /* Convert the ada entity type into a GCC TYPE_DECL node. */
128 }
129 \f
130 /* Given GNAT_ENTITY, a GNAT defining identifier node, which denotes some Ada
131 entity, this routine returns the equivalent GCC tree for that entity
132 (an ..._DECL node) and associates the ..._DECL node with the input GNAT
133 defining identifier.
135 If GNAT_ENTITY is a variable or a constant declaration, GNU_EXPR gives its
136 initial value (in GCC tree form). This is optional for variables.
137 For renamed entities, GNU_EXPR gives the object being renamed.
139 DEFINITION is nonzero if this call is intended for a definition. This is
140 used for separate compilation where it necessary to know whether an
141 external declaration or a definition should be created if the GCC equivalent
142 was not created previously. The value of 1 is normally used for a non-zero
143 DEFINITION, but a value of 2 is used in special circumstances, defined in
144 the code. */
146 tree
148 Entity_Id gnat_entity;
149 tree gnu_expr;
151 {
152 tree gnu_entity_id;
154 /* Contains the gnu XXXX_DECL tree node which is equivalent to the input
155 GNAT tree. This node will be associated with the GNAT node by calling
156 the save_gnu_tree routine at the end of the `switch' statement. */
158 /* Nonzero if we have already saved gnu_decl as a gnat association. */
160 /* Nonzero if we incremented defer_incomplete_level. */
162 /* Nonzero if we incremented force_global. */
164 /* Nonzero if we should check to see if elaborated during processing. */
166 /* Nonzero if we made GNU_DECL and its type here. */
172 Entity_Id gnat_temp;
173 unsigned int esize
178 ? LONG_DOUBLE_TYPE_SIZE
183 int imported_p
188 /* Since a use of an Itype is a definition, process it as such if it
189 is not in a with'ed unit. */
194 {
195 /* Ensure that we are in a subprogram mentioned in the Scope
196 chain of this entity, our current scope is global,
197 or that we encountered a task or entry (where we can't currently
198 accurately check scoping). */
201 {
204 }
208 {
213 gnat_temp
225 && (current_function_decl
227 {
230 }
231 }
233 /* gigi abort 122 means that the entity "gnat_entity" has an incorrect
234 scope, i.e. that its scope does not correspond to the subprogram
235 in which it is declared */
237 }
239 /* If this is entity 0, something went badly wrong. */
243 /* If we've already processed this entity, return what we got last time.
244 If we are defining the node, we should not have already processed it.
245 In that case, we will abort below when we try to save a new GCC tree for
246 this object. We also need to handle the case of getting a dummy type
247 when a Full_View exists. */
250 && (! definition
252 {
259 {
265 }
268 }
270 /* If this is a numeric or enumeral type, or an access type, a nonzero
271 Esize must be specified unless it was specified by the programmer. */
280 /* Likewise, RM_Size must be specified for all discrete and fixed-point
281 types. */
286 /* Get the name of the entity and set up the line number and filename of
287 the original definition for use in any decl we make. */
292 /* If we get here, it means we have not yet done anything with this
293 entity. If we are not defining it here, it must be external,
294 otherwise we should have defined it already. */
296 && ! type_annotate_only
300 #if 1
302 #endif
303 )
306 /* For cases when we are not defining (i.e., we are referencing from
307 another compilation unit) Public entities, show we are at global level
308 for the purpose of computing sizes. Don't do this for components or
309 discriminants since the relevant test is whether or not the record is
310 being defined. */
316 /* Handle any attributes. */
321 {
323 /* If this is a use of a deferred constant, get its full
324 declaration. */
326 {
331 }
333 /* If we have an external constant that we are not defining,
334 get the expression that is was defined to represent. We
335 may throw that expression away later if it is not a
336 constant. */
342 /* Ignore deferred constant definitions; they are processed fully in the
343 front-end. For deferred constant references, get the full
344 definition. On the other hand, constants that are renamings are
345 handled like variable renamings. If No_Initialization is set, this is
346 not a deferred constant but a constant whose value is built
347 manually. */
352 {
356 }
359 {
364 }
369 /* If this is not a VMS exception, treat it as a normal object.
370 Otherwise, make an object at the specific address of character
371 type, point to it, and convert it to integer, and mask off
372 the lower 3 bits. */
376 /* Allocate the global object that we use to get the value of the
377 exception. */
385 /* Now return the expression giving the desired value. */
386 gnu_decl
390 gnu_decl)),
400 {
401 /* The GNAT record where the component was defined. */
404 /* If the variable is an inherited record component (in the case of
405 extended record types), just return the inherited entity, which
406 must be a FIELD_DECL. Likewise for discriminants.
407 For discriminants of untagged records which have explicit
408 girder discriminants, return the entity for the corresponding
409 girder discriminant. Also use Original_Record_Component
410 if the record has a private extension. */
417 {
418 gnu_decl
423 }
425 /* If the enclosing record has explicit girder discriminants,
426 then it is an untagged record. If the Corresponding_Discriminant
427 is not empty then this must be a renamed discriminant and its
428 Original_Record_Component must point to the corresponding explicit
429 girder discriminant (i.e., we should have taken the previous
430 branch). */
434 {
435 /* A tagged record has no explicit girder discriminants. */
441 gnu_decl
446 }
448 /* If the enclosing record has explicit girder discriminants,
449 then it is an untagged record. If the Corresponding_Discriminant
450 is not empty then this must be a renamed discriminant and its
451 Original_Record_Component must point to the corresponding explicit
452 girder discriminant (i.e., we should have taken the first
453 branch). */
460 /* Otherwise, if we are not defining this and we have no GCC type
461 for the containing record, make one for it. Then we should
462 have made our own equivalent. */
464 {
465 /* ??? If this is in a record whose scope is a protected
466 type and we have an Original_Record_Component, use it.
467 This is a workaround for major problems in protected type
468 handling. */
471 {
472 gnu_decl
478 }
484 }
486 /* Here we have no GCC type and this is a reference rather than a
487 definition. This should never happen. Most likely the cause is a
488 reference before declaration in the gnat tree for gnat_entity. */
489 else
491 }
497 /* Simple variables, loop variables, OUT parameters, and exceptions. */
498 object:
499 {
501 int const_flag
514 {
518 else
520 }
522 /* Get the type after elaborating the renamed object. */
525 /* If this is a loop variable, its type should be the base type.
526 This is because the code for processing a loop determines whether
527 a normal loop end test can be done by comparing the bounds of the
528 loop against those of the base type, which is presumed to be the
529 size used for computation. But this is not correct when the size
530 of the subtype is smaller than the type. */
534 /* Reject non-renamed objects whose types are unconstrained arrays or
535 any object whose type is a dummy type or VOID_TYPE. */
541 {
544 else
546 }
548 /* If we are defining the object, see if it has a Size value and
549 validate it if so. Then get the new type, if any. */
556 {
557 gnu_type
563 }
565 /* If this object has self-referential size, it must be a record with
566 a default value. We are supposed to allocate an object of the
567 maximum size in this case unless it is a constant with an
568 initializing expression, in which case we can get the size from
569 that. Note that the resulting size may still be a variable, so
570 this may end up with an indirect allocation. */
575 {
577 {
581 {
584 /* Strip off any conversions in GNU_EXPR since
585 they can't be changing the size to allocate. */
594 }
595 }
597 /* We may have no GNU_EXPR because No_Initialization is
598 set even though there's an Expression. */
603 gnu_size
605 (Etype
607 else
609 }
611 /* If the size is zero bytes, make it one byte since some linkers
612 have trouble with zero-sized objects. But if this will have a
613 template, that will make it nonzero. */
621 /* If an alignment is specified, use it if valid. Note that
622 exceptions are objects but don't have alignments. */
624 {
628 align
631 }
633 /* If this is an atomic object with no specified size and alignment,
634 but where the size of the type is a constant, set the alignment to
635 the lowest power of two greater than the size, or to the
636 biggest meaningful alignment, whichever is smaller. */
640 {
643 BIGGEST_ALIGNMENT))
645 else
650 }
652 #ifdef MINIMUM_ATOMIC_ALIGNMENT
653 /* If the size is a constant and no alignment is specified, force
654 the alignment to be the minimum valid atomic alignment. The
655 restriction on constant size avoids problems with variable-size
656 temporaries; if the size is variable, there's no issue with
657 atomic access. Also don't do this for a constant, since it isn't
658 necessary and can interfere with constant replacement. Finally,
659 do not do it for Out parameters since that creates an
660 size inconsistency with In parameters. */
669 #endif
671 /* If the object is set to have atomic components, find the component
672 type and validate it.
674 ??? Note that we ignore Has_Volatile_Components on objects; it's
675 not at all clear what to do in that case. */
678 {
679 tree gnu_inner
688 }
690 /* Make a new type with the desired size and alignment, if needed. */
694 /* Make a volatile version of this object's type if we are to
695 make the object volatile. Note that 13.3(19) says that we
696 should treat other types of objects as volatile as well. */
706 /* If this is an aliased object with an unconstrained nominal subtype,
707 make a type that includes the template. */
711 {
712 tree gnu_fat
714 tree gnu_temp_type
717 gnu_type
721 }
723 /* Convert the expression to the type of the object except in the
724 case where the object's type is unconstrained or the object's type
725 is a padded record whose field is of self-referential size. In
726 the former case, converting will generate unnecessary evaluations
727 of the CONSTRUCTOR to compute the size and in the latter case, we
728 want to only copy the actual data. */
735 && (contains_placeholder_p
739 /* See if this is a renaming. If this is a constant renaming,
740 treat it as a normal variable whose initial value is what
741 is being renamed. We cannot do this if the type is
742 unconstrained or class-wide.
744 Otherwise, if what we are renaming is a reference, we can simply
745 return a stabilized version of that reference, after forcing
746 any SAVE_EXPRs to be evaluated. But, if this is at global level,
747 we can only do this if we know no SAVE_EXPRs will be made.
748 Otherwise, make this into a constant pointer to the object we are
749 to rename. */
752 {
753 /* If the renamed object had padding, strip off the reference
754 to the inner object and reset our type. */
758 && (TYPE_IS_PADDING_P
760 {
763 }
770 ;
772 /* If this is a declaration or reference, we can just use that
773 declaration or reference as this entity. */
780 {
788 gnu_decl));
790 }
791 else
792 {
799 }
800 }
802 /* If this is an aliased object whose nominal subtype is unconstrained,
803 the object is a record that contains both the template and
804 the object. If there is an initializer, it will have already
805 been converted to the right type, but we need to create the
806 template if there is no initializer. */
810 gnu_expr
811 = build_constructor
813 tree_cons
815 build_template
818 NULL_TREE),
819 NULL_TREE));
821 /* If this is a pointer and it does not have an initializing
822 expression, initialize it to NULL. */
828 /* If we are defining the object and it has an Address clause we must
829 get the address expression from the saved GCC tree for the
830 object if the object has a Freeze_Node. Otherwise, we elaborate
831 the address expression here since the front-end has guaranteed
832 in that case that the elaboration has no effects. Note that
833 only the latter mechanism is currently in use. */
835 {
836 tree gnu_address
842 /* Ignore the size. It's either meaningless or was handled
843 above. */
850 /* If we don't have an initializing expression for the underlying
851 variable, the initializing expression for the pointer is the
852 specified address. Otherwise, we have to make a COMPOUND_EXPR
853 to assign both the address and the initial value. */
856 else
857 gnu_expr
859 build_binary_op
862 gnu_address),
863 gnu_expr),
864 gnu_address);
865 }
867 /* If it has an address clause and we are not defining it, mark it
868 as an indirect object. Likewise for Stdcall objects that are
869 imported. */
873 {
877 }
879 /* If we are at top level and this object is of variable size,
880 make the actual type a hidden pointer to the real type and
881 make the initializer be a memory allocation and initialization.
882 Likewise for objects we aren't defining (presumed to be
883 external references from other packages), but there we do
884 not set up an initialization.
886 If the object's size overflows, make an allocator too, so that
887 Storage_Error gets raised. Note that we will never free
888 such memory, so we presume it never will get allocated. */
897 {
903 /* Get the data part of GNU_EXPR in case this was a
904 aliased object whose nominal subtype is unconstrained.
905 In that case the pointer above will be a thin pointer and
906 build_allocator will automatically make the template and
907 constructor already made above. */
910 {
915 {
916 gnu_alloc_type
918 gnu_expr
919 = build_component_ref
922 }
928 gnat_entity);
932 }
933 else
934 {
937 }
938 }
940 /* If this object would go into the stack and has an alignment
941 larger than the default largest alignment, make a variable
942 to hold the "aligning type" with a modified initial value,
943 if any, then point to it and make that the value of this
944 variable, which is now indirect. */
948 {
949 tree gnu_new_type
952 tree gnu_new_var;
955 gnu_expr
960 gnu_new_var
966 gnu_expr
967 = build_unary_op
975 }
977 /* Convert the expression to the type of the object except in the
978 case where the object's type is unconstrained or the object's type
979 is a padded record whose field is of self-referential size. In
980 the former case, converting will generate unnecessary evaluations
981 of the CONSTRUCTOR to compute the size and in the latter case, we
982 want to only copy the actual data. */
989 && (contains_placeholder_p
993 /* This name is external or there was a name specified, use it.
994 Don't use the Interface_Name if there is an address clause.
995 (see CD30005). */
1006 /* If this is constant initialized to a static constant and the
1007 object has an aggregrate type, force it to be statically
1008 allocated. */
1032 STACK_CHECK_MAX_VAR_SIZE))))
1035 /* If this is a public constant or we're not optimizing and we're not
1036 making a VAR_DECL for it, make one just for export or debugger
1037 use. Likewise if the address is taken or if the object or type is
1038 aliased. */
1053 /* If this is declared in a block that contains an block with an
1054 exception handler, we must force this variable in memory to
1055 suppress an invalid optimization. */
1057 {
1060 }
1062 /* Back-annotate the Alignment of the object if not already in the
1063 tree. Likewise for Esize if the object is of a constant size. */
1070 {
1075 gnu_back_size
1080 }
1081 }
1085 /* Return a TYPE_DECL for "void" that we previously made. */
1090 /* A special case, for the types Character and Wide_Character in
1091 Standard, we do not list all the literals. So if the literals
1092 are not specified, make this an unsigned type. */
1094 {
1097 }
1099 /* Normal case of non-character type, or non-Standard character type */
1100 {
1101 /* Here we have a list of enumeral constants in First_Literal.
1102 We make a CONST_DECL for each and build into GNU_LITERAL_LIST
1103 the list to be places into TYPE_FIELDS. Each node in the list
1104 is a TREE_LIST node whose TREE_VALUE is the literal name
1105 and whose TREE_PURPOSE is the value of the literal.
1107 Esize contains the number of bits needed to represent the enumeral
1108 type, Type_Low_Bound also points to the first literal and
1109 Type_High_Bound points to the last literal. */
1111 Entity_Id gnat_literal;
1116 else
1124 {
1126 gnu_type);
1127 tree gnu_literal
1134 }
1138 /* Note that the bounds are updated at the end of this function
1139 because to avoid an infinite recursion when we get the bounds of
1140 this type, since those bounds are objects of this type. */
1141 }
1147 /* For integer types, just make a signed type the appropriate number
1148 of bits. */
1153 /* For modular types, make the unsigned type of the proper number of
1154 bits and then set up the modulus, if required. */
1155 {
1157 tree gnu_modulus;
1163 /* Find the smallest mode at least ESIZE bits wide and make a class
1164 using that mode. */
1169 ;
1175 /* Get the modulus in this type. If it overflows, assume it is because
1176 it is equal to 2**Esize. Note that there is no overflow checking
1177 done on unsigned type, so we detect the overflow by looking for
1178 a modulus of zero, which is otherwise invalid. */
1182 {
1187 }
1189 /* If we have to set TYPE_PRECISION different from its natural value,
1190 make a subtype to do do. Likewise if there is a modulus and
1191 it is not one greater than TYPE_MAX_VALUE. */
1195 {
1212 }
1213 }
1222 /* For integral subtypes, we make a new INTEGER_TYPE. Note
1223 that we do not want to call build_range_type since we would
1224 like each subtype node to be distinct. This will be important
1225 when memory aliasing is implemented.
1227 The TREE_TYPE field of the INTEGER_TYPE we make points to the
1228 parent type; this fact is used by the arithmetic conversion
1229 functions.
1231 We elaborate the Ancestor_Subtype if it is not in the current
1232 unit and one of our bounds is non-static. We do this to ensure
1233 consistent naming in the case where several subtypes share the same
1234 bounds by always elaborating the first such subtype first, thus
1235 using its name. */
1247 {
1251 }
1259 gnat_entity,
1266 gnat_entity,
1270 /* One of the above calls might have caused us to be elaborated,
1271 so don't blow up if so. */
1273 {
1276 }
1281 /* This should be an unsigned type if the lower bound is constant
1282 and non-negative or if the base type is unsigned; a signed type
1283 otherwise. */
1294 {
1296 tree gnu_field;
1309 }
1314 /* If this is a VAX floating-point type, use an integer of the proper
1315 size. All the operations will be handled with ASM statements. */
1317 {
1323 }
1325 /* The type of the Low and High bounds can be our type if this is
1326 a type from Standard, so set them at the end of the function. */
1334 {
1337 }
1339 {
1354 ;
1374 /* One of the above calls might have caused us to be elaborated,
1375 so don't blow up if so. */
1377 {
1380 }
1383 }
1386 /* Array and String Types and Subtypes
1388 Unconstrained array types are represented by E_Array_Type and
1389 constrained array types are represented by E_Array_Subtype. There
1390 are no actual objects of an unconstrained array type; all we have
1391 are pointers to that type.
1393 The following fields are defined on array types and subtypes:
1395 Component_Type Component type of the array.
1396 Number_Dimensions Number of dimensions (an int).
1397 First_Index Type of first index. */
1401 {
1407 int firstdim
1409 int nextdim
1415 tree gnu_max_size_unit;
1417 Entity_Id gnat_ind_subtype;
1418 Entity_Id gnat_ind_base_subtype;
1419 tree gnu_template_reference;
1420 tree tem;
1428 /* Make a node for the array. If we are not defining the array
1429 suppress expanding incomplete types and save the node as the type
1430 for GNAT_ENTITY. */
1433 {
1434 defer_incomplete_level++;
1438 debug_info_p);
1441 }
1443 /* Build the fat pointer type. Use a "void *" object instead of
1444 a pointer to the array type since we don't have the array type
1445 yet (it will reference the fat pointer via the bounds). */
1448 ptr_void_type_node,
1451 gnu_ptr_template,
1454 /* Make sure we can put this into a register. */
1458 /* Build a reference to the template from a PLACEHOLDER_EXPR that
1459 is the fat pointer. This will be used to access the individual
1460 fields once we build them. */
1464 gnu_template_reference
1468 /* Now create the GCC type for each index and add the fields for
1469 that index to the template. */
1471 gnat_ind_base_subtype
1477 {
1479 tree gnu_ind_subtype
1481 tree gnu_base_subtype
1483 tree gnu_base_min
1485 tree gnu_base_max
1489 /* Make the FIELD_DECLs for the minimum and maximum of this
1490 type and then make extractions of that field from the
1491 template. */
1495 gnu_ind_subtype,
1499 gnu_ind_subtype,
1504 /* We can't use build_component_ref here since the template
1505 type isn't complete yet. */
1512 /* Make a range type with the new ranges, but using
1513 the Ada subtype. Then we convert to sizetype. */
1519 /* Update the maximum size of the array, in elements. */
1520 gnu_max_size
1524 gnu_base_min)));
1528 }
1531 gnu_template_fields
1534 /* Install all the fields into the template. */
1538 /* Now make the array of arrays and update the pointer to the array
1539 in the fat pointer. Note that it is the first field. */
1543 /* Get and validate any specified Component_Size, but if Packed,
1544 ignore it since the front end will have taken care of it. Also,
1545 allow sizes not a multiple of Storage_Unit if packed. */
1546 gnu_comp_size
1548 gnat_entity,
1556 /* If the component type is a RECORD_TYPE that has a self-referential
1557 size, use the maxium size. */
1564 {
1568 }
1574 /* If Component_Size is not already specified, annotate it with the
1575 size of the component. */
1585 gnu_max_size),
1589 {
1594 }
1596 /* If an alignment is specified, use it if valid. But ignore it for
1597 types that represent the unpacked base type for packed arrays. */
1600 {
1607 }
1613 /* The result type is an UNCONSTRAINED_ARRAY_TYPE that indicates the
1614 corresponding fat pointer. */
1621 /* If the maximum size doesn't overflow, use it. */
1624 {
1630 }
1634 debug_info_p);
1637 /* Create a record type for the object and its template and
1638 set the template at a negative offset. */
1650 /* Give the thin pointer type a name. */
1654 }
1660 /* This is the actual data type for array variables. Multidimensional
1661 arrays are implemented in the gnu tree as arrays of arrays. Note
1662 that for the moment arrays which have sparse enumeration subtypes as
1663 index components create sparse arrays, which is obviously space
1664 inefficient but so much easier to code for now.
1666 Also note that the subtype never refers to the unconstrained
1667 array type, which is somewhat at variance with Ada semantics.
1669 First check to see if this is simply a renaming of the array
1670 type. If so, the result is the array type. */
1675 else
1676 {
1679 int first_dim
1682 int next_dim
1684 Entity_Id gnat_ind_subtype;
1685 Entity_Id gnat_ind_base_subtype;
1690 tree gnu_max_size_unit;
1694 /* First create the gnu types for each index. Create types for
1695 debugging information to point to the index types if the
1696 are not integer types, have variable bounds, or are
1697 wider than sizetype. */
1700 gnat_ind_base_subtype
1706 {
1707 tree gnu_index_subtype
1709 tree gnu_min
1711 tree gnu_max
1713 tree gnu_base_subtype
1715 tree gnu_base_min
1717 tree gnu_base_max
1720 tree gnu_base_base_min
1722 tree gnu_base_base_max
1724 tree gnu_high;
1725 tree gnu_this_max;
1727 /* If the minimum and maximum values both overflow in
1728 SIZETYPE, but the difference in the original type
1729 does not overflow in SIZETYPE, ignore the overflow
1730 indications. */
1736 && (! TREE_OVERFLOW
1744 /* Similarly, if the range is null, use bounds of 1..0 for
1745 the sizetype bounds. */
1755 /* Now compute the size of this bound. We need to provide
1756 GCC with an upper bound to use but have to deal with the
1757 "superflat" case. There are three ways to do this. If we
1758 can prove that the array can never be superflat, we can
1759 just use the high bound of the index subtype. If we can
1760 prove that the low bound minus one can't overflow, we
1761 can do this as MAX (hb, lb - 1). Otherwise, we have to use
1762 the expression hb >= lb ? hb : lb - 1. */
1765 /* See if the base array type is already flat. If it is, we
1766 are probably compiling an ACVC test, but it will cause the
1767 code below to malfunction if we don't handle it specially. */
1775 /* If gnu_high is now an integer which overflowed, the array
1776 cannot be superflat. */
1783 else
1784 gnu_high
1785 = build_cond_expr
1793 /* Also compute the maximum size of the array. Here we
1794 see if any constraint on the index type of the base type
1795 can be used in the case of self-referential bound on
1796 the index type of the subtype. We look for a non-"infinite"
1797 and non-self-referential bound from any type involved and
1798 handle each bound separately. */
1825 gnu_this_max
1829 gnu_base_min)),
1830 size_zero_node);
1836 gnu_max_size
1850 }
1852 /* Then flatten: create the array of arrays. */
1856 /* One of the above calls might have caused us to be elaborated,
1857 so don't blow up if so. */
1859 {
1862 }
1864 /* Get and validate any specified Component_Size, but if Packed,
1865 ignore it since the front end will have taken care of it. Also,
1866 allow sizes not a multiple of Storage_Unit if packed. */
1867 gnu_comp_size
1869 gnat_entity,
1874 /* If the component type is a RECORD_TYPE that has a self-referential
1875 size, use the maxium size. */
1882 {
1887 }
1900 /* We don't want any array types shared for two reasons: first,
1901 we want to keep differently-named types distinct; second,
1902 setting TYPE_MULTI_ARRAY_TYPE of one type can clobber
1903 another. */
1906 {
1911 }
1913 /* If we are at file level and this is a multi-dimensional array, we
1914 need to make a variable corresponding to the stride of the
1915 inner dimensions. */
1917 {
1919 tree gnu_arr_type;
1925 {
1931 = elaborate_expression_1
1934 }
1935 }
1937 /* If we need to write out a record type giving the names of
1938 the bounds, do it now. */
1940 {
1943 tree gnu_field;
1949 {
1950 tree gnu_type_name
1957 integer_type_node,
1958 gnu_bound_rec_type,
1962 }
1965 }
1971 /* If our size depends on a placeholder and the maximum size doesn't
1972 overflow, use it. */
1978 {
1984 }
1986 /* Set our alias set to that of our base type. This gives all
1987 array subtypes the same alias set. */
1990 }
1992 /* If this is a packed type, make this type the same as the packed
1993 array type, but do some adjusting in the type first. */
1996 {
1997 Entity_Id gnat_index;
1998 tree gnu_inner_type;
2000 /* First finish the type we had been making so that we output
2001 debugging information for it */
2004 | (TYPE_QUAL_VOLATILE
2009 debug_info_p);
2013 /* Save it as our equivalent in case the call below elaborates
2014 this type again. */
2028 /* We need to point the type we just made to our index type so
2029 the actual bounds can be put into a template. */
2035 {
2037 {
2038 /* The TYPE_ACTUAL_BOUNDS field is also used for the modulus.
2039 If it is, we need to make another type. */
2041 {
2042 tree gnu_subtype;
2059 }
2062 }
2080 }
2081 }
2083 /* Abort if packed array with no packed array type field set. */
2090 /* Create the type for a string literal. */
2091 {
2092 Entity_Id gnat_full_type
2097 tree gnu_string_array_type
2099 tree gnu_string_index_type
2101 tree gnu_lower_bound
2106 tree gnu_upper_bound
2108 gnu_lower_bound,
2110 tree gnu_range_type
2113 tree gnu_index_type
2118 gnu_range_type);
2120 gnu_type
2122 gnu_index_type);
2123 }
2126 /* Record Types and Subtypes
2128 The following fields are defined on record types:
2130 Has_Discriminants True if the record has discriminants
2131 First_Discriminant Points to head of list of discriminants
2132 First_Entity Points to head of list of fields
2133 Is_Tagged_Type True if the record is tagged
2135 Implementation of Ada records and discriminated records:
2137 A record type definition is transformed into the equivalent of a C
2138 struct definition. The fields that are the discriminants which are
2139 found in the Full_Type_Declaration node and the elements of the
2140 Component_List found in the Record_Type_Definition node. The
2141 Component_List can be a recursive structure since each Variant of
2142 the Variant_Part of the Component_List has a Component_List.
2144 Processing of a record type definition comprises starting the list of
2145 field declarations here from the discriminants and the calling the
2146 function components_to_record to add the rest of the fields from the
2147 component list and return the gnu type node. The function
2148 components_to_record will call itself recursively as it traverses
2149 the tree. */
2152 #if 0
2154 {
2155 gnu_type
2156 = build_complex_type
2157 (get_unpadded_type
2160 (Component_List
2161 (Type_Definition
2164 /* ??? For now, don't use Complex if the real type is shorter than
2165 a word. */
2169 }
2170 #endif
2172 {
2175 Entity_Id gnat_field;
2176 tree gnu_field;
2178 tree gnu_get_parent;
2185 int is_extension
2189 /* See if all fields have a rep clause. Stop when we find one
2190 that doesn't. */
2199 /* If this is a record extension, go a level further to find the
2200 record definition. Also, verify we have a Parent_Subtype. */
2202 {
2209 }
2211 /* Make a node for the record. If we are not defining the record,
2212 suppress expanding incomplete types and save the node as the type
2213 for GNAT_ENTITY. We use the same RECORD_TYPE as was made
2214 for a dummy type and then show it's no longer a dummy. */
2224 {
2225 defer_incomplete_level++;
2230 debug_info_p);
2233 }
2235 /* If both a size and rep clause was specified, put the size in
2236 the record type now so that it can get the proper mode. */
2240 /* Always set the alignment here so that it can be used to
2241 set the mode, if it is making the alignment stricter. If
2242 it is invalid, it will be checked again below. If this is to
2243 be Atomic, choose a default alignment of a word. */
2251 /* If we have a Parent_Subtype, make a field for the parent. If
2252 this record has rep clauses, force the position to zero. */
2254 {
2255 tree gnu_parent;
2257 /* A major complexity here is that the parent subtype will
2258 reference our discriminants. But those must reference
2259 the parent component of this record. So here we will
2260 initialize each of those components to a COMPONENT_REF.
2261 The first operand of that COMPONENT_REF is another
2262 COMPONENT_REF which will be filled in below, once
2263 the parent type can be safely built. */
2268 NULL_TREE));
2275 save_gnu_tree
2279 gnu_get_parent,
2287 gnu_field_list
2297 }
2299 /* Add the fields for the discriminants into the record. */
2305 {
2306 /* If this is a record extension and this discriminant
2307 is the renaming of another discriminant, we've already
2308 handled the discriminant above. */
2313 gnu_field
2316 /* Make an expression using a PLACEHOLDER_EXPR from the
2317 FIELD_DECL node just created and link that with the
2318 corresponding GNAT defining identifier. Then add to the
2319 list of fields. */
2324 gnu_field),
2329 }
2331 /* Put the discriminants into the record (backwards), so we can
2332 know the appropriate discriminant to use for the names of the
2333 variants. */
2336 /* Add the listed fields into the record and finish up. */
2345 /* If this is an extension type, reset the tree for any
2346 inherited discriminants. Also remove the PLACEHOLDER_EXPR
2347 for non-inherited discriminants. */
2353 {
2357 else
2358 {
2362 }
2363 }
2365 /* If it is a tagged record force the type to BLKmode to insure
2366 that these objects will always be placed in memory. Do the
2367 same thing for limited record types. */
2372 /* Fill in locations of fields. */
2375 /* If there are any entities in the chain corresponding to
2376 components that we did not elaborate, ensure we elaborate their
2377 types if they are Itypes. */
2385 }
2389 /* If an equivalent type is present, that is what we should use.
2390 Otherwise, fall through to handle this like a record subtype
2391 since it may have constraints. */
2394 {
2398 }
2400 /* ... fall through ... */
2404 /* If Cloned_Subtype is Present it means this record subtype has
2405 identical layout to that type or subtype and we should use
2406 that GCC type for this one. The front end guarantees that
2407 the component list is shared. */
2409 {
2413 }
2415 /* Otherwise, first ensure the base type is elaborated. Then, if we are
2416 changing the type, make a new type with each field having the
2417 type of the field in the new subtype but having the position
2418 computed by transforming every discriminant reference according
2419 to the constraints. We don't see any difference between
2420 private and nonprivate type here since derivations from types should
2421 have been deferred until the completion of the private type. */
2422 else
2423 {
2425 tree gnu_base_type;
2426 tree gnu_orig_type;
2431 /* Get the base type initially for its alignment and sizes. But
2432 if it is a padded type, we do all the other work with the
2433 unpadded type. */
2442 {
2445 }
2447 /* When the type has discriminants, and these discriminants
2448 affect the shape of what it built, factor them in.
2450 If we are making a subtype of an Unchecked_Union (must be an
2451 Itype), just return the type.
2453 We can't just use Is_Constrained because private subtypes without
2454 discriminants of full types with discriminants with default
2455 expressions are Is_Constrained but aren't constrained! */
2463 {
2464 Entity_Id gnat_field;
2465 Entity_Id gnat_root_type;
2467 tree gnu_pos_list
2470 tree gnu_subst_list
2472 definition);
2473 tree gnu_temp;
2475 /* If this is a derived type, we may be seeing fields from any
2476 original records, so add those positions and discriminant
2477 substitutions to our lists. */
2481 {
2482 gnu_pos_list
2483 = compute_field_positions
2488 gnu_subst_list
2491 }
2503 {
2504 tree gnu_old_field
2505 = gnat_to_gnu_entity
2507 tree gnu_offset
2509 gnu_pos_list));
2512 tree gnu_field_type
2516 tree gnu_field;
2518 /* If there was a component clause, the field types must be
2519 the same for the type and subtype, so copy the data from
2520 the old field to avoid recomputation here. */
2523 {
2526 }
2528 /* If this was a bitfield, get the size from the old field.
2529 Also ensure the type can be placed into a bitfield. */
2531 {
2537 }
2547 /* If the size is now a constant, we can set it as the
2548 size of the field when we make it. Otherwise, we need
2549 to deal with it specially. */
2553 gnu_field
2554 = create_field_decl
2560 {
2565 SET_DECL_OFFSET_ALIGN
2571 bitsize_unit_node));
2573 }
2587 }
2591 /* Now set the size, alignment and alias set of the new type to
2592 match that of the old one, doing any substitutions, as
2593 above. */
2628 /* Recompute the mode of this record type now that we know its
2629 actual size. */
2632 /* Fill in locations of fields. */
2634 }
2636 /* If we've made a new type, record it and make an XVS type to show
2637 what this is a subtype of. Some debuggers require the XVS
2638 type to be output first, so do it in that order. */
2640 {
2642 {
2653 integer_type_node,
2654 gnu_subtype_marker,
2658 }
2664 gnu_type));
2668 }
2670 /* Otherwise, go down all the components in the new type and
2671 make them equivalent to those in the base type. */
2672 else
2679 get_gnu_tree
2681 }
2685 /* If we are not defining this entity, and we have incomplete
2686 entities being processed above us, make a dummy type and
2687 fill it in later. */
2689 {
2693 gnu_type
2694 = build_pointer_type
2698 debug_info_p);
2707 }
2709 /* ... fall through ... */
2716 {
2718 Entity_Id gnat_desig_full
2720 Incomplete_Or_Private_Kind))
2722 /* We want to know if we'll be seeing the freeze node for any
2723 incomplete type we may be pointing to. */
2724 int in_main_unit
2736 {
2738 {
2742 }
2744 Incomplete_Or_Private_Kind))
2746 }
2751 /* If either the designated type or its full view is an
2752 unconstrained array subtype, replace it with the type it's a
2753 subtype of. This avoids problems with multiple copies of
2754 unconstrained array types. */
2763 /* If we are pointing to an incomplete type whose completion is an
2764 unconstrained array, make a fat pointer type instead of a pointer
2765 to VOID. The two types in our fields will be pointers to VOID and
2766 will be replaced in update_pointer_to. Similiarly, if the type
2767 itself is a dummy type or an unconstrained array. Also make
2768 a dummy TYPE_OBJECT_RECORD_TYPE in case we have any thin
2769 pointers to it. */
2790 {
2791 tree gnu_old
2795 tree fields;
2797 /* Show the dummy we get will be a fat pointer. */
2800 /* If the call above got something that has a pointer, that
2801 pointer is our type. This could have happened either
2802 because the type was elaborated or because somebody
2803 else executed the code below. */
2806 {
2812 fields
2814 create_field_decl
2819 ptr_void_type_node,
2822 /* Make sure we can place this into a register. */
2833 }
2834 }
2836 /* If we already know what the full type is, use it. */
2841 /* Get the type of the thing we are to point to and build a pointer
2842 to it. If it is a reference to an incomplete or private type with a
2843 full view that is a record, make a dummy type node and get the
2844 actual type later when we have verified it is safe. */
2850 {
2853 }
2855 /* Likewise if we are pointing to a record or array and we are to defer
2856 elaborating incomplete types. We do this since this access type
2857 may be the full view of some private type. Note that the
2858 unconstrained array case is handled above. */
2866 {
2869 }
2871 {
2874 }
2875 else
2878 /* It is possible that the above call to gnat_to_gnu_type resolved our
2879 type. If so, just return it. */
2881 {
2884 }
2886 /* If we have a GCC type for the designated type, possibly
2887 modify it if we are pointing only to constant objects and then
2888 make a pointer to it. Don't do this for unconstrained arrays. */
2890 {
2893 gnu_desig_type
2899 }
2901 /* If we are not defining this object and we made a dummy pointer,
2902 save our current definition, evaluate the actual type, and replace
2903 the tentative type we made with the actual one. If we are to defer
2904 actually looking up the actual type, make an entry in the
2905 deferred list. */
2908 {
2909 tree gnu_old_type
2915 gnu_type
2916 = build_pointer_type
2917 (TYPE_OBJECT_RECORD_TYPE
2922 debug_info_p);
2929 else
2930 {
2938 }
2939 }
2940 }
2946 else
2947 /* The runtime representation is the equivalent type. */
2961 /* We treat this as identical to its base type; any constraint is
2962 meaningful only to the front end.
2964 The designated type must be elaborated as well, if it does
2965 not have its own freeze node. Designated (sub)types created
2966 for constrained components of records with discriminants are
2967 not frozen by the front end and thus not elaborated by gigi,
2968 because their use may appear before the base type is frozen,
2969 and because it is not clear that they are needed anywhere in
2970 Gigi. With the current model, there is no correct place where
2971 they could be elaborated. */
2978 {
2979 /* If we are not defining this entity, and we have incomplete
2980 entities being processed above us, make a dummy type and
2981 elaborate it later. */
2983 {
2986 tree gnu_ptr_type
2987 = build_pointer_type
2994 }
2995 else
2998 }
3003 /* Subprogram Entities
3005 The following access functions are defined for subprograms (functions
3006 or procedures):
3008 First_Formal The first formal parameter.
3009 Is_Imported Indicates that the subprogram has appeared in
3010 an INTERFACE or IMPORT pragma. For now we
3011 assume that the external language is C.
3012 Is_Inlined True if the subprogram is to be inlined.
3014 In addition for function subprograms we have:
3016 Etype Return type of the function.
3018 Each parameter is first checked by calling must_pass_by_ref on its
3019 type to determine if it is passed by reference. For parameters which
3020 are copied in, if they are Ada IN OUT or OUT parameters, their return
3021 value becomes part of a record which becomes the return type of the
3022 function (C function - note that this applies only to Ada procedures
3023 so there is no Ada return type). Additional code to store back the
3024 parameters will be generated on the caller side. This transformation
3025 is done here, not in the front-end.
3027 The intended result of the transformation can be seen from the
3028 equivalent source rewritings that follow:
3030 struct temp {int a,b};
3031 procedure P (A,B: IN OUT ...) is temp P (int A,B) {
3032 .. ..
3033 end P; return {A,B};
3034 }
3035 procedure call
3037 {
3038 temp t;
3039 P(X,Y); t = P(X,Y);
3040 X = t.a , Y = t.b;
3041 }
3043 For subprogram types we need to perform mainly the same conversions to
3044 GCC form that are needed for procedures and function declarations. The
3045 only difference is that at the end, we make a type declaration instead
3046 of a function declaration. */
3051 {
3052 /* The first GCC parameter declaration (a PARM_DECL node). The
3053 PARM_DECL nodes are chained through the TREE_CHAIN field, so this
3054 actually is the head of this parameter list. */
3056 /* The type returned by a function. If the subprogram is a procedure
3057 this type should be void_type_node. */
3059 /* List of fields in return type of procedure with copy in copy out
3060 parameters. */
3062 /* Non-null for subprograms containing parameters passed by copy in
3063 copy out (Ada IN OUT or OUT parameters not passed by reference),
3064 in which case it is the list of nodes used to specify the values of
3065 the in out/out parameters that are returned as a record upon
3066 procedure return. The TREE_PURPOSE of an element of this list is
3067 a field of the record and the TREE_VALUE is the PARM_DECL
3068 corresponding to that field. This list will be saved in the
3069 TYPE_CI_CO_LIST field of the FUNCTION_TYPE node we create. */
3071 Entity_Id gnat_param;
3074 int extern_flag
3085 /* A parameter may refer to this type, so defer completion
3086 of any incomplete types. */
3089 /* If the subprogram has an alias, it is probably inherited, so
3090 we can use the original one. If the original "subprogram"
3091 is actually an enumeration literal, it may be the first use
3092 of its type, so we must elaborate that type now. */
3094 {
3101 /* Elaborate any Itypes in the parameters of this entity. */
3109 }
3114 /* If this function returns by reference, make the actual
3115 return type of this function the pointer and mark the decl. */
3117 {
3121 }
3123 /* If we are supposed to return an unconstrained array,
3124 actually return a fat pointer and make a note of that. Return
3125 a pointer to an unconstrained record of variable size. */
3127 {
3130 }
3132 /* If the type requires a transient scope, the result is allocated
3133 on the secondary stack, so the result type of the function is
3134 just a pointer. */
3136 {
3139 }
3141 /* If the type is a padded type and the underlying type would not
3142 be passed by reference or this function has a foreign convention,
3143 return the underlying type. */
3151 /* Look at all our parameters and get the type of
3152 each. While doing this, build a copy-out structure if
3153 we need one. */
3158 {
3168 /* See if a Mechanism was supplied that forced this
3169 parameter to be passed one way or another. */
3173 ;
3181 {
3187 else
3189 }
3190 else
3193 /* If this is either a foreign function or if the
3194 underlying type won't be passed by refererence, strip off
3195 possible padding type. */
3203 /* If this is an IN parameter it is read-only, so make a variant
3204 of the type that is read-only.
3206 ??? However, if this is an unconstrained array, that type can
3207 be very complex. So skip it for now. Likewise for any other
3208 self-referential type. */
3214 gnu_param_type
3219 /* For foreign conventions, pass arrays as a pointer to the
3220 underlying type. First check for unconstrained array and get
3221 the underlying array. Then get the component type and build
3222 a pointer to it. */
3225 gnu_param_type
3230 gnu_param_type
3231 = build_pointer_type
3234 gnat_entity));
3237 && ! req_by_copy
3239 {
3240 /* Strip off any multi-dimensional entries, then strip
3241 off the last array to get the component type. */
3250 gnu_param_type
3256 }
3258 /* Fat pointers are passed as thin pointers for foreign
3259 conventions. */
3262 gnu_param_type
3266 /* If we must pass or were requested to pass by reference, do so.
3267 If we were requested to pass by copy, do so.
3268 Otherwise, for foreign conventions, pass all in out parameters
3269 or aggregates by reference. For COBOL and Fortran, pass
3270 all integer and FP types that way too. For Convention Ada,
3271 use the standard Ada default. */
3273 || (! req_by_copy
3283 /* For convention Ada, see if we pass by reference
3284 by default. */
3287 {
3290 }
3298 /* If this is an OUT parameter that isn't passed by reference
3299 and isn't a pointer or aggregate, we don't make a PARM_DECL
3300 for it. Instead, it will be a VAR_DECL created when we process
3301 the procedure. For the special parameter of Valued_Procedure,
3302 never pass it in. */
3305 || (! by_descr_p
3309 else
3310 {
3312 gnu_param
3313 = create_param_decl
3315 by_ref_p || by_component_ptr_p
3327 /* If a parameter is a pointer, this function may modify
3328 memory through it and thus shouldn't be considered
3329 a pure function. Also, the memory may be modified
3330 between two calls, so they can't be CSE'ed. The latter
3331 case also handles by-ref parameters. */
3335 }
3338 {
3340 {
3347 }
3355 gnu_return_list);
3356 }
3357 }
3359 /* Do not compute record for out parameters if subprogram is
3360 stubbed since structures are incomplete for the back-end. */
3366 /* If we have a CICO list but it has only one entry, we convert
3367 this function into a function that simply returns that one
3368 object. */
3373 {
3383 }
3385 /* Both lists ware built in reverse. */
3389 gnu_type
3392 returns_by_ref,
3395 /* ??? For now, don't consider nested functions pure. */
3399 gnu_type
3405 /* Top-level or external functions need to have an assembler name.
3406 This is passed to create_subprog_decl through the ext_name argument.
3407 For Pragma Interface subprograms with no Pragma Interface_Name, the
3408 simple name already in entity_name is correct, and this is what is
3409 gotten when ext_name is NULL. If Interface_Name is specified, then
3410 the name is extracted from the N_String_Literal node containing the
3411 string specified in the Pragma. If there is no Pragma Interface,
3412 then the Ada fully qualified name is created. */
3420 /* If we are defining the subprogram and it has an Address clause
3421 we must get the address expression from the saved GCC tree for the
3422 subprogram if it has a Freeze_Node. Otherwise, we elaborate
3423 the address expression here since the front-end has guaranteed
3424 in that case that the elaboration has no effects. If there is
3425 an Address clause and we are not defining the object, just
3426 make it a constant. */
3428 {
3432 gnu_address
3443 gnu_decl
3448 }
3453 debug_info_p);
3454 else
3455 {
3462 }
3463 }
3474 /* If this type does not have a full view in the unit we are
3475 compiling, then just get the type from its Etype. */
3477 {
3478 /* If this is an incomplete type with no full view, it must
3479 be a Taft Amendement type, so just return a dummy type. */
3486 else
3487 {
3491 }
3494 }
3496 /* Otherwise, if we are not defining the type now, get the
3497 type from the full view. But always get the type from the full
3498 view for define on use types, since otherwise we won't see them! */
3505 {
3510 }
3512 /* For incomplete types, make a dummy type entry which will be
3513 replaced later. */
3516 /* Save this type as the full declaration's type so we can do any needed
3517 updates when we see it. */
3521 debug_info_p);
3525 /* Simple class_wide types are always viewed as their root_type
3526 by Gigi unless an Equivalent_Type is specified. */
3530 else
3542 else
3554 /* Nothing at all to do here, so just return an ERROR_MARK and claim
3555 we've already saved it, so we don't try to. */
3562 }
3564 /* If we had a case where we evaluated another type and it might have
3565 defined this one, handle it here. */
3567 {
3570 }
3572 /* If we are processing a type and there is either no decl for it or
3573 we just made one, do some common processing for the type, such as
3574 handling alignment and possible padding. */
3577 {
3584 /* ??? Don't set the size for a String_Literal since it is either
3585 confirming or we don't handle it properly (if the low bound is
3586 non-constant). */
3591 /* If a size was specified, see if we can make a new type of that size
3592 by rearranging the type, for example from a fat to a thin pointer. */
3594 {
3595 gnu_type
3602 }
3604 /* If the alignment hasn't already been processed and this is
3605 not an unconstrained array, see if an alignment is specified.
3606 If not, we pick a default alignment for atomic objects. */
3608 ;
3622 /* See if we need to pad the type. If we did, and made a record,
3623 the name of the new type may be changed. So get it back for
3624 us when we make the new TYPE_DECL below. */
3629 {
3633 }
3637 /* If we are at global level, GCC will have applied variable_size to
3638 the type, but that won't have done anything. So, if it's not
3639 a constant or self-referential, call elaborate_expression_1 to
3640 make a variable for the size rather than calculating it each time.
3641 Handle both the RM size and the actual size. */
3646 {
3656 {
3672 }
3673 else
3674 {
3685 }
3686 }
3688 /* If this is a record type or subtype, call elaborate_expression_1 on
3689 any field position. Do this for both global and local types.
3690 Skip any fields that we haven't made trees for to avoid problems with
3691 class wide types. */
3696 {
3706 }
3710 | (TYPE_QUAL_VOLATILE
3720 {
3724 debug_info_p);
3725 }
3726 else
3728 }
3731 {
3734 /* Back-annotate the Alignment of the type if not already in the
3735 tree. Likewise for sizes. */
3741 {
3742 /* If the size is self-referential, we annotate the maximum
3743 value of that size. */
3750 }
3754 }
3763 /* If this decl is really indirect, adjust it. */
3767 /* If we haven't already, associate the ..._DECL node that we just made with
3768 the input GNAT entity node. */
3772 /* If this is an enumeral or floating-point type, we were not able to set
3773 the bounds since they refer to the type. These bounds are always static.
3775 For enumeration types, also write debugging information and declare the
3776 enumeration literal table, if needed. */
3780 {
3783 /* If this is a padded type, we need to use the underlying type. */
3788 /* If this is a floating point type and we haven't set a floating
3789 point type yet, use this in the evaluation of the bounds. */
3799 {
3802 /* Since this has both a typedef and a tag, avoid outputting
3803 the name twice. */
3806 }
3807 }
3809 /* If we deferred processing of incomplete types, re-enable it. If there
3810 were no other disables and we have some to process, do so. */
3813 {
3819 {
3826 }
3827 }
3829 /* If we are not defining this type, see if it's in the incomplete list.
3830 If so, handle that list entry now. */
3832 {
3837 {
3841 }
3842 }
3845 force_global--;
3854 }
3855 \f
3856 /* Given GNAT_ENTITY, elaborate all expressions that are required to
3857 be elaborated at the point of its definition, but do nothing else. */
3859 void
3861 Entity_Id gnat_entity;
3862 {
3864 {
3871 {
3875 /* ??? Tests for avoiding static constaint error expression
3876 is needed until the front stops generating bogus conversions
3877 on bounds of real types. */
3886 }
3889 {
3893 /* If this is a record extension, go a level further to find the
3894 record definition. */
3897 }
3907 {
3908 Node_Id gnat_discriminant_expr;
3909 Entity_Id gnat_field;
3912 gnat_discriminant_expr
3917 /* ??? For now, ignore access discriminants. */
3920 gnat_entity,
3922 }
3925 }
3926 }
3927 \f
3928 /* Mark GNAT_ENTITY as going out of scope at this point. Recursively mark
3929 any entities on its entity chain similarly. */
3931 void
3933 Entity_Id gnat_entity;
3934 {
3935 Entity_Id gnat_sub_entity;
3938 /* If this has an entity list, process all in the list. */
3955 /* Now clear this if it has been defined, but only do so if it isn't
3956 a subprogram or parameter. We could refine this, but it isn't
3957 worth it. If this is statically allocated, it is supposed to
3958 hang around out of cope. */
3961 {
3964 }
3965 }
3966 \f
3967 /* Return a TREE_LIST describing the substitutions needed to reflect
3968 discriminant substitutions from GNAT_SUBTYPE to GNAT_TYPE and add
3969 them to GNU_LIST. If GNAT_TYPE is not specified, use the base type
3970 of GNAT_SUBTYPE. The substitions can be in any order. TREE_PURPOSE
3971 gives the tree for the discriminant and TREE_VALUES is the replacement
3972 value. They are in the form of operands to substitute_in_expr.
3973 DEFINITION is as in gnat_to_gnu_entity. */
3975 static tree
3977 Entity_Id gnat_subtype;
3978 Entity_Id gnat_type;
3979 tree gnu_list;
3981 {
3982 Entity_Id gnat_discrim;
3983 Node_Id gnat_value;
3994 /* Ignore access discriminants. */
3997 elaborate_expression
4001 gnu_list);
4004 }
4005 \f
4006 /* For the following two functions: for each GNAT entity, the GCC
4007 tree node used as a dummy for that entity, if any. */
4011 /* Initialize the above table. */
4013 void
4015 {
4016 Node_Id gnat_node;
4025 }
4027 /* Make a dummy type corresponding to GNAT_TYPE. */
4029 tree
4031 Entity_Id gnat_type;
4032 {
4033 Entity_Id gnat_underlying;
4034 tree gnu_type;
4036 /* Find a full type for GNAT_TYPE, taking into account any class wide
4037 types. */
4047 ;
4049 /* If it there already a dummy type, use that one. Else make one. */
4053 /* If this is a record, make this a RECORD_TYPE or UNION_TYPE; else make
4054 it a VOID_TYPE. */
4058 else
4070 }
4071 \f
4072 /* Return 1 if the size represented by GNU_SIZE can be handled by an
4073 allocation. If STATIC_P is non-zero, consider only what can be
4074 done with a static allocation. */
4076 static int
4078 tree gnu_size;
4080 {
4081 /* If this is not a static allocation, the only case we want to forbid
4082 is an overflowing size. That will be converted into a raise a
4083 Storage_Error. */
4088 /* Otherwise, we need to deal with both variable sizes and constant
4089 sizes that won't fit in a host int. */
4091 }
4092 \f
4093 /* Return a list of attributes for GNAT_ENTITY, if any. */
4097 Entity_Id gnat_entity;
4098 {
4100 Node_Id gnat_temp;
4105 {
4115 {
4117 (gnat_to_gnu
4124 (gnat_to_gnu
4125 (Expression
4128 }
4131 {
4150 }
4157 attr->error_point
4161 }
4164 }
4165 \f
4166 /* Get the unpadded version of a GNAT type. */
4168 tree
4170 Entity_Id gnat_entity;
4171 {
4178 }
4179 \f
4180 /* Called when we need to protect a variable object using a save_expr. */
4182 tree
4184 tree gnu_operand;
4185 Node_Id gnat_node;
4186 {
4192 /* If we will be generating code, make sure we are at the proper
4193 line number. */
4201 else
4203 }
4204 \f
4205 /* Given a GNAT tree GNAT_EXPR, for an expression which is a value within a
4206 type definition (either a bound or a discriminant value) for GNAT_ENTITY,
4207 return the GCC tree to use for that expression. GNU_NAME is the
4208 qualification to use if an external name is appropriate and DEFINITION is
4209 nonzero if this is a definition of GNAT_ENTITY. If NEED_VALUE is nonzero,
4210 we need a result. Otherwise, we are just elaborating this for
4211 side-effects. If NEED_DEBUG is nonzero we need the symbol for debugging
4212 purposes even if it isn't needed for code generation. */
4214 static tree
4217 Node_Id gnat_expr;
4218 Entity_Id gnat_entity;
4219 tree gnu_name;
4223 {
4224 tree gnu_expr;
4226 /* If we already elaborated this expression (e.g., it was involved
4227 in the definition of a private type), use the old value. */
4231 /* If we don't need a value and this is static or a discriment, we
4232 don't need to do anything. */
4239 /* Otherwise, convert this tree to its GCC equivalant. */
4240 gnu_expr
4244 /* Save the expression in case we try to elaborate this entity again.
4245 Since this is not a DECL, don't check it. If this is a constant,
4246 don't save it since GNAT_EXPR might be used more than once. Also,
4247 don't save if it's a discriminant. */
4252 }
4254 /* Similar, but take a GNU expression. */
4256 static tree
4258 need_debug)
4259 Node_Id gnat_expr;
4260 Entity_Id gnat_entity;
4261 tree gnu_expr;
4262 tree gnu_name;
4265 {
4271 /* Strip any conversions to see if the expression is a readonly variable.
4272 ??? This really should remain readonly, but we have to think about
4273 the typing of the tree here. */
4278 /* In most cases, we won't see a naked FIELD_DECL here because a
4279 discriminant reference will have been replaced with a COMPONENT_REF
4280 when the type is being elaborated. However, there are some cases
4281 involving child types where we will. So convert it to a COMPONENT_REF
4282 here. We have to hope it will be at the highest level of the
4283 expression in these cases. */
4287 gnu_expr);
4289 /* If GNU_EXPR is neither a placeholder nor a constant, nor a variable
4290 that is a constant, make a variable that is initialized to contain the
4291 bound when the package containing the definition is elaborated. If
4292 this entity is defined at top level and a bound or discriminant value
4293 isn't a constant or a reference to a discriminant, replace the bound
4294 by the variable; otherwise use a SAVE_EXPR if needed. Note that we
4295 rely here on the fact that an expression cannot contain both the
4296 discriminant and some other variable. */
4303 /* If this is a static expression or contains a discriminant, we don't
4304 need the variable for debugging (and can't elaborate anyway if a
4305 discriminant). */
4311 /* Now create the variable if we need it. */
4313 {
4315 gnu_decl
4320 }
4322 /* We only need to use this variable if we are in global context since GCC
4323 can do the right thing in the local case. */
4326 else
4328 }
4329 \f
4330 /* Create a record type that contains a field of TYPE with a starting bit
4331 position so that it is aligned to ALIGN bits and is SIZE bytes long. */
4333 tree
4335 tree type;
4337 tree size;
4338 {
4343 place));
4352 /* The bit position is obtained by "and"ing the alignment minus 1
4353 with the two's complement of the address and multiplying
4354 by the number of bits per unit. Do all this in sizetype. */
4360 size_addr_place),
4363 bitsize_unit_node);
4374 bitsize_unit_node),
4380 }
4381 \f
4382 /* TYPE is a RECORD_TYPE with BLKmode that's being used as the field
4383 type of a packed record. See if we can rewrite it as a record that has
4384 a non-BLKmode type, which we can pack tighter. If so, return the
4385 new type. If not, return the original type. */
4387 static tree
4389 tree type;
4390 {
4393 tree old_field;
4395 /* Copy the name and flags from the old type to that of the new and set
4396 the alignment to try for an integral type. */
4406 /* Now copy the fields, keeping the position and size. */
4409 {
4410 tree new_field
4423 }
4427 }
4428 \f
4429 /* Ensure that TYPE has SIZE and ALIGN. Make and return a new padded type
4430 if needed. We have already verified that SIZE and TYPE are large enough.
4432 GNAT_ENTITY and NAME_TRAILER are used to name the resulting record and
4433 to issue a warning.
4435 IS_USER_TYPE is nonzero if we must be sure we complete the original type.
4437 DEFINITION is nonzero if this type is being defined.
4439 SAME_RM_SIZE is nonzero if the RM_Size of the resulting type is to be
4440 set to its TYPE_SIZE; otherwise, it's set to the RM_Size of the original
4441 type. */
4443 static tree
4446 tree type;
4447 tree size;
4449 Entity_Id gnat_entity;
4454 {
4456 tree record;
4457 tree field;
4459 /* If TYPE is a padded type, see if it agrees with any size and alignment
4460 we were given. If so, return the original type. Otherwise, strip
4461 off the padding, since we will either be returning the inner type
4462 or repadding it. If no size or alignment is specified, use that of
4463 the original padded type. */
4466 {
4483 }
4485 /* If the size is either not being changed or is being made smaller (which
4486 is not done here (and is only valid for bitfields anyway), show the size
4487 isn't changing. Likewise, clear the alignment if it isn't being
4488 changed. Then return if we aren't doing anything. */
4502 /* We used to modify the record in place in some cases, but that could
4503 generate incorrect debugging information. So make a new record
4504 type and name. */
4510 /* If we were making a type, complete the original type and give it a
4511 name. */
4519 /* If we are changing the alignment and the input type is a record with
4520 BLKmode and a small constant size, try to make a form that has an
4521 integral mode. That might allow this record to have an integral mode,
4522 which will be much more efficient. There is no point in doing this if a
4523 size is specified unless it is also smaller than the biggest alignment
4524 and it is incorrect to do this if the size of the original type is not a
4525 multiple of the alignment. */
4545 bitsize_unit_node));
4552 /* Keep the RM_Size of the padded record as that of the old record
4553 if requested. */
4556 /* Unless debugging information isn't being written for the input type,
4557 write a record that shows what we are a subtype of and also make a
4558 variable that indicates our size, if variable. */
4563 {
4582 }
4590 /* If the size was widened explicitly, maybe give a warning. */
4596 {
4609 /* Generate message only for entities that come from source, since
4610 if we have an entity created by expansion, the message will be
4611 generated for some other corresponding source entity. */
4614 gnat_entity,
4621 }
4624 }
4625 \f
4626 /* Given a GNU tree and a GNAT list of choices, generate an expression to test
4627 the value passed against the list of choices. */
4629 tree
4631 tree operand;
4632 Node_Id choices;
4633 {
4634 Node_Id choice;
4635 Node_Id gnat_temp;
4640 {
4642 {
4647 /* There's no good type to use here, so we might as well use
4648 integer_type_node. */
4649 this_test
4663 this_test
4673 /* This represents either a subtype range, an enumeration
4674 literal, or a constant Ekind says which. If an enumeration
4675 literal or constant, fall through to the next case. */
4678 {
4684 this_test
4691 }
4692 /* ... fall through ... */
4697 single);
4706 }
4710 }
4713 }
4714 \f
4715 /* Return a GCC tree for a field corresponding to GNAT_FIELD to be
4716 placed in GNU_RECORD_TYPE.
4718 PACKED is 1 if the enclosing record is packed and -1 if the enclosing
4719 record has a Component_Alignment of Storage_Unit.
4721 DEFINITION is nonzero if this field is for a record being defined. */
4723 static tree
4725 Entity_Id gnat_field;
4726 tree gnu_record_type;
4729 {
4735 tree gnu_field;
4736 int needs_strict_alignment
4740 /* If this field requires strict alignment pretend it isn't packed. */
4744 /* For packed records, this is one of the few occasions on which we use
4745 the official RM size for discrete or fixed-point components, instead
4746 of the normal GNAT size stored in Esize. See description in Einfo:
4747 "Handling of Type'Size Values" for further details. */
4757 /* If we are packing this record and the field type is also a record
4758 that's BLKmode and with a small constant size, see if we can get a
4759 better form of the type that allows more packing. If we can, show
4760 a size was specified for it if there wasn't one so we know to
4761 make this a bitfield and avoid making things wider. */
4766 {
4771 }
4774 {
4779 /* Ensure the position does not overlap with the parent subtype,
4780 if there is one. */
4782 {
4783 tree gnu_parent
4789 {
4790 post_error_ne_tree
4794 }
4795 }
4797 /* If this field needs strict alignment, ensure the record is
4798 sufficiently aligned and that that position and size are
4799 consistent with the alignment. */
4801 {
4808 /* If Atomic, the size must match exactly and if aliased, the size
4809 must not be less than the rounded size. */
4812 {
4813 post_error_ne_tree
4819 }
4824 {
4825 post_error_ne_tree
4828 gnu_min_size);
4830 }
4835 {
4837 post_error_ne_num
4843 post_error_ne_num
4849 post_error_ne_num
4853 else
4857 }
4859 /* If an error set the size to zero, show we have no position
4860 either. */
4863 }
4870 bitsize_unit_node))))
4871 {
4872 /* Try to see if we can make this a packable type. If we
4873 can, it's OK. */
4878 {
4883 }
4884 }
4885 }
4887 /* If the record has rep clauses and this is the tag field, make a rep
4888 clause for it as well. */
4891 {
4894 }
4896 /* We need to make the size the maximum for the type if it is
4897 self-referential and an unconstrained type. */
4905 /* If no size is specified (or if there was an error), don't specify a
4906 position. */
4909 else
4910 {
4911 /* Unless this field is aliased, we can remove any left-justified
4912 modular type since it's only needed in the unchecked conversion
4913 case, which doesn't apply here. */
4919 gnu_field_type
4924 }
4942 }
4943 \f
4944 /* Return a GCC tree for a record type given a GNAT Component_List and a chain
4945 of GCC trees for fields that are in the record and have already been
4946 processed. When called from gnat_to_gnu_entity during the processing of a
4947 record type definition, the GCC nodes for the discriminants will be on
4948 the chain. The other calls to this function are recursive calls from
4949 itself for the Component_List of a variant and the chain is empty.
4951 PACKED is 1 if this is for a record with "pragma pack" and -1 is this is
4952 for a record type with "pragma component_alignment (storage_unit)".
4954 FINISH_RECORD is nonzero if this call will supply all of the remaining
4955 fields of the record.
4957 P_GNU_REP_LIST, if nonzero, is a pointer to a list to which each field
4958 with a rep clause is to be added. If it is nonzero, that is all that
4959 should be done with such fields.
4961 CANCEL_ALIGNMENT, if nonzero, means the alignment should be zeroed
4962 before laying out the record. This means the alignment only serves
4963 to force fields to be bitfields, but not require the record to be
4964 that aligned. This is used for variants.
4966 ALL_REP, if nonzero, means that a rep clause was found for all the
4967 fields. This simplifies the logic since we know we're not in the mixed
4968 case.
4970 The processing of the component list fills in the chain with all of the
4971 fields of the record and then the record type is finished. */
4973 static void
4976 tree gnu_record_type;
4977 Node_Id component_list;
4978 tree gnu_field_list;
4984 {
4985 Node_Id component_decl;
4986 Entity_Id gnat_field;
4987 Node_Id variant_part;
4988 Node_Id variant;
4993 /* For each variable within each component declaration create a GCC field
4994 and add it to the list, skipping any pragmas in the list. */
5000 {
5005 else
5006 {
5010 /* If this is the _Tag field, put it before any discriminants,
5011 instead of after them as is the case for all other fields. */
5014 else
5015 {
5018 }
5019 }
5022 }
5024 /* At the end of the component list there may be a variant part. */
5027 /* If this is an unchecked union, each variant must have exactly one
5028 component, each of which becomes one component of this union. */
5033 {
5034 component_decl
5038 definition);
5042 }
5044 /* We create a QUAL_UNION_TYPE for the variant part since the variants are
5045 mutually exclusive and should go in the same memory. To do this we need
5046 to treat each variant as a record whose elements are created from the
5047 component list for the variant. So here we create the records from the
5048 lists for the variants and put them all into the QUAL_UNION_TYPE. */
5050 {
5052 Node_Id variant;
5054 tree gnu_union_field;
5057 tree gnu_var_name
5058 = concat_id_with_name
5072 {
5074 tree gnu_inner_name;
5075 tree gnu_qual;
5083 /* Set the alignment of the inner type in case we need to make
5084 inner objects into bitfields, but then clear it out
5085 so the record actually gets only the alignment required. */
5102 }
5104 /* We can delete any empty variants from the end. This may leave none
5105 left. Note we cannot delete variants from anywhere else. */
5110 /* Only make the QUAL_UNION_TYPE if there are any non-empty variants. */
5112 {
5116 gnu_union_field
5118 packed,
5125 }
5126 }
5128 /* Scan GNU_FIELD_LIST and see if any fields have rep clauses. If they
5129 do, pull them out and put them into GNU_OUR_REP_LIST. We have to do this
5130 in a separate pass since we want to handle the discriminants but can't
5131 play with them until we've used them in debugging data above.
5133 ??? Note: if we then reorder them, debugging information will be wrong,
5134 but there's nothing that can be done about this at the moment. */
5137 {
5139 {
5144 else
5150 }
5151 else
5152 {
5155 }
5156 }
5158 /* If we have any items in our rep'ed field list, it is not the case that all
5159 the fields in the record have rep clauses, and P_REP_LIST is nonzero,
5160 set it and ignore the items. Otherwise, sort the fields by bit position
5161 and put them into their own record if we have any fields without
5162 rep clauses. */
5166 {
5167 tree gnu_rep_type
5173 /* Set DECL_SECTION_NAME to increasing integers so we have a
5174 stable sort. */
5177 {
5180 }
5184 /* Put the fields in the list in order of increasing position, which
5185 means we start from the end. */
5188 {
5193 }
5196 {
5202 }
5203 else
5204 {
5207 }
5208 }
5215 }
5216 \f
5217 /* Called via qsort from the above. Returns -1, 1, depending on the
5218 bit positions and ordinals of the two fields. */
5220 static int
5224 {
5229 return
5234 else
5236 }
5237 \f
5238 /* Given GNU_SIZE, a GCC tree representing a size, return a Uint to be
5239 placed into an Esize, Component_Bit_Offset, or Component_Size value
5240 in the GNAT tree. */
5242 static Uint
5244 tree gnu_size;
5245 {
5247 TCode tcode;
5252 /* If we do not return inside this switch, TCODE will be set to the
5253 code to use for a Create_Node operand and LEN (set above) will be
5254 the number of recursive calls for us to make. */
5257 {
5262 /* This may have come from a conversion from some smaller type,
5263 so ensure this is in bitsizetype. */
5266 /* For negative values, use NEGATE_EXPR of the supplied value. */
5268 {
5269 /* The rediculous code below is to handle the case of the largest
5270 negative integer. */
5273 tree temp;
5276 {
5277 negative_size
5280 bitsize_one_node));
5282 }
5289 }
5296 /* This peculiar test is to make sure that the size fits in an int
5297 on machines where HOST_WIDE_INT is not "int". */
5300 else
5304 /* The only case we handle here is a simple discriminant reference. */
5312 else
5318 /* Now just list the operations we handle. */
5349 }
5351 /* Now get each of the operands that's relevant for this code. If any
5352 cannot be expressed as a repinfo node, say we can't. */
5357 {
5361 }
5364 }
5366 /* Given GNAT_ENTITY, a record type, and GNU_TYPE, its corresponding
5367 GCC type, set Component_Bit_Offset and Esize to the position and size
5368 used by Gigi. */
5370 static void
5372 Entity_Id gnat_entity;
5373 tree gnu_type;
5374 {
5375 tree gnu_list;
5376 tree gnu_entry;
5377 Entity_Id gnat_field;
5379 /* We operate by first making a list of all field and their positions
5380 (we can get the sizes easily at any time) by a recursive call
5381 and then update all the sizes into the tree. */
5392 gnu_list)))
5393 {
5394 Set_Component_Bit_Offset
5402 }
5403 }
5405 /* Scan all fields in GNU_TYPE and build entries where TREE_PURPOSE is
5406 the FIELD_DECL and TREE_VALUE a TREE_LIST with TREE_PURPOSE being the
5407 byte position and TREE_VALUE being the bit position. GNU_POS is to
5408 be added to the position, GNU_BITPOS to the bit position, and GNU_LIST
5409 is the entries so far. */
5411 static tree
5413 tree gnu_type;
5414 tree gnu_list;
5415 tree gnu_pos;
5416 tree gnu_bitpos;
5417 {
5418 tree gnu_field;
5423 {
5429 gnu_result
5432 gnu_result);
5435 gnu_result
5438 }
5441 }
5442 \f
5443 /* UINT_SIZE is a Uint giving the specified size for an object of GNU_TYPE
5444 corresponding to GNAT_OBJECT. If size is valid, return a tree corresponding
5445 to its value. Otherwise return 0. KIND is VAR_DECL is we are specifying
5446 the size for an object, TYPE_DECL for the size of a type, and FIELD_DECL
5447 for the size of a field. COMPONENT_P is true if we are being called
5448 to process the Component_Size of GNAT_OBJECT. This is used for error
5449 message handling and to indicate to use the object size of GNU_TYPE.
5450 ZERO_OK is nonzero if a size of zero is permitted; if ZERO_OK is zero,
5451 it means that a size of zero should be treated as an unspecified size. */
5453 static tree
5455 Uint uint_size;
5456 tree gnu_type;
5457 Entity_Id gnat_object;
5461 {
5462 Node_Id gnat_error_node;
5463 tree type_size
5465 tree size;
5480 else
5483 /* Don't give errors on packed array types; we'll be giving the error on
5484 the type itself soon enough. */
5488 /* Get the size as a tree. Return 0 if none was specified, either because
5489 Esize was not Present or if the specified size was zero. Give an error
5490 if a size was specified, but cannot be represented as in sizetype. If
5491 the size is negative, it was a back-annotation of a variable size and
5492 should be treated as not specified. */
5498 {
5502 else
5506 }
5508 /* Ignore a negative size since that corresponds to our back-annotation.
5509 Also ignore a zero size unless a size clause exists. */
5513 /* The size of objects is always a multiple of a byte. */
5516 bitsize_unit_node)))
5517 {
5521 else
5525 }
5527 /* If this is an integral type, the front-end has verified the size, so we
5528 need not do it here (which would entail checking against the bounds).
5529 However, if this is an aliased object, it may not be smaller than the
5530 type of the object. */
5535 /* If the object is a record that contains a template, add the size of
5536 the template to the specified size. */
5541 /* If the size of the object is a constant, the new size must not be
5542 smaller. */
5546 {
5548 post_error_ne_tree
5551 else
5558 post_error_ne_tree_2
5568 }
5571 }
5572 \f
5573 /* Similarly, but both validate and process a value of RM_Size. This
5574 routine is only called for types. */
5576 static void
5578 Uint uint_size;
5579 tree gnu_type;
5580 Entity_Id gnat_entity;
5581 {
5582 /* Only give an error if a Value_Size clause was explicitly given.
5583 Otherwise, we'd be duplicating an error on the Size clause. */
5584 Node_Id gnat_attr_node
5587 tree size;
5589 /* Get the size as a tree. Do nothing if none was specified, either
5590 because RM_Size was not Present or if the specified size was zero.
5591 Give an error if a size was specified, but cannot be represented as
5592 in sizetype. */
5598 {
5601 gnat_entity);
5604 }
5606 /* Ignore a negative size since that corresponds to our back-annotation.
5607 Also ignore a zero size unless a size clause exists, a Value_Size
5608 clause exists, or this is an integer type, in which case the
5609 front end will have always set it. */
5616 /* If the old size is self-referential, get the maximum size. */
5621 /* If the size of the object is a constant, the new size must not be
5622 smaller (the front end checks this for scalar types). */
5627 {
5629 post_error_ne_tree
5634 }
5636 /* Otherwise, set the RM_Size. */
5647 }
5648 \f
5649 /* Given a type TYPE, return a new type whose size is appropriate for SIZE.
5650 If TYPE is the best type, return it. Otherwise, make a new type. We
5651 only support new integral and pointer types. BIASED_P is nonzero if
5652 we are making a biased type. */
5654 static tree
5656 tree type;
5657 tree size_tree;
5659 {
5660 tree new_type;
5663 /* If size indicates an error, just return TYPE to avoid propagating the
5664 error. Likewise if it's too large to represent. */
5670 {
5673 /* Only do something if the type is not already the proper size and is
5674 not a packed array type. */
5699 /* Do something if this is a fat pointer, in which case we
5700 may need to return the thin pointer. */
5702 return
5703 build_pointer_type
5708 /* Only do something if this is a thin pointer, in which case we
5709 may need to return the fat pointer. */
5711 return
5718 }
5721 }
5722 \f
5723 /* ALIGNMENT is a Uint giving the alignment specified for GNAT_ENTITY,
5724 a type or object whose present alignment is ALIGN. If this alignment is
5725 valid, return it. Otherwise, give an error and return ALIGN. */
5727 static unsigned int
5729 Uint alignment;
5730 Entity_Id gnat_entity;
5732 {
5736 #ifndef MAX_OFILE_ALIGNMENT
5737 #define MAX_OFILE_ALIGNMENT BIGGEST_ALIGNMENT
5738 #endif
5743 /* Within GCC, an alignment is an integer, so we must make sure a
5744 value is specified that fits in that range. Also, alignments of
5745 more than MAX_OFILE_ALIGNMENT can't be supported. */
5759 else
5763 }
5764 \f
5765 /* Verify that OBJECT, a type or decl, is something we can implement
5766 atomically. If not, give an error for GNAT_ENTITY. COMP_P is nonzero
5767 if we require atomic components. */
5769 static void
5771 tree object;
5772 Entity_Id gnat_entity;
5774 {
5776 Node_Id gnat_node;
5779 tree size;
5781 /* There are three case of what OBJECT can be. It can be a type, in which
5782 case we take the size, alignment and mode from the type. It can be a
5783 declaration that was indirect, in which case the relevant values are
5784 that of the type being pointed to, or it can be a normal declaration,
5785 in which case the values are of the decl. The code below assumes that
5786 OBJECT is either a type or a decl. */
5788 {
5792 }
5794 {
5798 }
5799 else
5800 {
5804 }
5806 /* Consider all floating-point types atomic and any types that that are
5807 represented by integers no wider than a machine word. */
5814 /* For the moment, also allow anything that has an alignment equal
5815 to its size and which is smaller than a word. */
5823 {
5831 }
5836 else
5839 }
5840 \f
5841 /* Given a type T, a FIELD_DECL F, and a replacement value R,
5842 return a new type with all size expressions that contain F
5843 updated by replacing F with R. This is identical to GCC's
5844 substitute_in_type except that it knows about TYPE_INDEX_TYPE.
5845 If F is NULL_TREE, always make a new RECORD_TYPE, even if nothing has
5846 changed. */
5848 tree
5851 {
5853 tree tem;
5856 {
5865 {
5877 }
5888 {
5902 }
5918 /* Don't know how to do these yet. */
5922 {
5936 }
5941 {
5942 tree field;
5943 int changed_field
5950 /* Start out with no fields, make new fields, and chain them
5951 in. If we haven't actually changed the type of any field,
5952 discard everything we've done and return the old type. */
5959 {
5970 /* If this is an internal field and the type of this field is
5971 a UNION_TYPE or RECORD_TYPE with no elements, ignore it. If
5972 the type just has one element, treat that as the field.
5973 But don't do this if we are processing a QUAL_UNION_TYPE. */
5978 {
5983 {
5984 tree next_new_field
5987 /* Make sure omitting the union doesn't change
5988 the layout. */
5991 }
5992 }
5999 /* If the size of the old field was set at a constant,
6000 propagate the size in case the type's size was variable.
6001 (This occurs in the case of a variant or discriminated
6002 record with a default size used as a field of another
6003 record.) */
6012 {
6018 /* Do the substitution inside the qualifier and if we find
6019 that this field will not be present, omit it. */
6024 }
6028 else
6033 /* If this is a qualified type and this field will always be
6034 present, we are done. */
6038 }
6040 /* If this used to be a qualified union type, but we now know what
6041 field will be present, make this a normal union. */
6054 /* If the size was originally a constant use it. */
6057 {
6061 }
6064 }
6068 }
6069 }
6070 \f
6071 /* Return the "RM size" of GNU_TYPE. This is the actual number of bits
6072 needed to represent the object. */
6074 tree
6076 tree gnu_type;
6077 {
6078 /* For integer types, this is the precision. For record types, we store
6079 the size explicitly. For other types, this is just the size. */
6085 /* Return the rm_size of the actual data plus the size of the template. */
6086 return
6096 else
6098 }
6099 \f
6100 /* Return an identifier representing the external name to be used for
6101 GNAT_ENTITY. If SUFFIX is specified, the name is followed by "___"
6102 and the specified suffix. */
6104 tree
6106 Entity_Id gnat_entity;
6108 {
6116 }
6118 /* Return the name to be used for GNAT_ENTITY. If a type, create a
6119 fully-qualified name, possibly with type information encoding.
6120 Otherwise, return the name. */
6122 tree
6124 Entity_Id gnat_entity;
6125 {
6128 }
6130 /* Given GNU_ID, an IDENTIFIER_NODE containing a name and SUFFIX, a
6131 string, return a new IDENTIFIER_NODE that is the concatenation of
6132 the name in GNU_ID and SUFFIX. */
6134 tree
6136 tree gnu_id;
6138 {
6147 }