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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.
1064 But if the "object" is actually a pointer to an object, the
1065 alignment and size are the same as teh type, so don't back-annotate
1066 the values for the pointer. */
1073 {
1078 gnu_back_size
1083 }
1084 }
1088 /* Return a TYPE_DECL for "void" that we previously made. */
1093 /* A special case, for the types Character and Wide_Character in
1094 Standard, we do not list all the literals. So if the literals
1095 are not specified, make this an unsigned type. */
1097 {
1100 }
1102 /* Normal case of non-character type, or non-Standard character type */
1103 {
1104 /* Here we have a list of enumeral constants in First_Literal.
1105 We make a CONST_DECL for each and build into GNU_LITERAL_LIST
1106 the list to be places into TYPE_FIELDS. Each node in the list
1107 is a TREE_LIST node whose TREE_VALUE is the literal name
1108 and whose TREE_PURPOSE is the value of the literal.
1110 Esize contains the number of bits needed to represent the enumeral
1111 type, Type_Low_Bound also points to the first literal and
1112 Type_High_Bound points to the last literal. */
1114 Entity_Id gnat_literal;
1119 else
1127 {
1129 gnu_type);
1130 tree gnu_literal
1137 }
1141 /* Note that the bounds are updated at the end of this function
1142 because to avoid an infinite recursion when we get the bounds of
1143 this type, since those bounds are objects of this type. */
1144 }
1150 /* For integer types, just make a signed type the appropriate number
1151 of bits. */
1156 /* For modular types, make the unsigned type of the proper number of
1157 bits and then set up the modulus, if required. */
1158 {
1160 tree gnu_modulus;
1166 /* Find the smallest mode at least ESIZE bits wide and make a class
1167 using that mode. */
1172 ;
1178 /* Get the modulus in this type. If it overflows, assume it is because
1179 it is equal to 2**Esize. Note that there is no overflow checking
1180 done on unsigned type, so we detect the overflow by looking for
1181 a modulus of zero, which is otherwise invalid. */
1185 {
1190 }
1192 /* If we have to set TYPE_PRECISION different from its natural value,
1193 make a subtype to do do. Likewise if there is a modulus and
1194 it is not one greater than TYPE_MAX_VALUE. */
1198 {
1215 }
1216 }
1225 /* For integral subtypes, we make a new INTEGER_TYPE. Note
1226 that we do not want to call build_range_type since we would
1227 like each subtype node to be distinct. This will be important
1228 when memory aliasing is implemented.
1230 The TREE_TYPE field of the INTEGER_TYPE we make points to the
1231 parent type; this fact is used by the arithmetic conversion
1232 functions.
1234 We elaborate the Ancestor_Subtype if it is not in the current
1235 unit and one of our bounds is non-static. We do this to ensure
1236 consistent naming in the case where several subtypes share the same
1237 bounds by always elaborating the first such subtype first, thus
1238 using its name. */
1250 {
1254 }
1262 gnat_entity,
1269 gnat_entity,
1273 /* One of the above calls might have caused us to be elaborated,
1274 so don't blow up if so. */
1276 {
1279 }
1284 /* This should be an unsigned type if the lower bound is constant
1285 and non-negative or if the base type is unsigned; a signed type
1286 otherwise. */
1297 {
1299 tree gnu_field;
1312 }
1317 /* If this is a VAX floating-point type, use an integer of the proper
1318 size. All the operations will be handled with ASM statements. */
1320 {
1326 }
1328 /* The type of the Low and High bounds can be our type if this is
1329 a type from Standard, so set them at the end of the function. */
1337 {
1340 }
1342 {
1357 ;
1377 /* One of the above calls might have caused us to be elaborated,
1378 so don't blow up if so. */
1380 {
1383 }
1386 }
1389 /* Array and String Types and Subtypes
1391 Unconstrained array types are represented by E_Array_Type and
1392 constrained array types are represented by E_Array_Subtype. There
1393 are no actual objects of an unconstrained array type; all we have
1394 are pointers to that type.
1396 The following fields are defined on array types and subtypes:
1398 Component_Type Component type of the array.
1399 Number_Dimensions Number of dimensions (an int).
1400 First_Index Type of first index. */
1404 {
1410 int firstdim
1412 int nextdim
1418 tree gnu_max_size_unit;
1420 Entity_Id gnat_ind_subtype;
1421 Entity_Id gnat_ind_base_subtype;
1422 tree gnu_template_reference;
1423 tree tem;
1431 /* Make a node for the array. If we are not defining the array
1432 suppress expanding incomplete types and save the node as the type
1433 for GNAT_ENTITY. */
1436 {
1437 defer_incomplete_level++;
1441 debug_info_p);
1444 }
1446 /* Build the fat pointer type. Use a "void *" object instead of
1447 a pointer to the array type since we don't have the array type
1448 yet (it will reference the fat pointer via the bounds). */
1451 ptr_void_type_node,
1454 gnu_ptr_template,
1457 /* Make sure we can put this into a register. */
1461 /* Build a reference to the template from a PLACEHOLDER_EXPR that
1462 is the fat pointer. This will be used to access the individual
1463 fields once we build them. */
1467 gnu_template_reference
1471 /* Now create the GCC type for each index and add the fields for
1472 that index to the template. */
1474 gnat_ind_base_subtype
1480 {
1482 tree gnu_ind_subtype
1484 tree gnu_base_subtype
1486 tree gnu_base_min
1488 tree gnu_base_max
1492 /* Make the FIELD_DECLs for the minimum and maximum of this
1493 type and then make extractions of that field from the
1494 template. */
1498 gnu_ind_subtype,
1502 gnu_ind_subtype,
1507 /* We can't use build_component_ref here since the template
1508 type isn't complete yet. */
1515 /* Make a range type with the new ranges, but using
1516 the Ada subtype. Then we convert to sizetype. */
1522 /* Update the maximum size of the array, in elements. */
1523 gnu_max_size
1527 gnu_base_min)));
1531 }
1534 gnu_template_fields
1537 /* Install all the fields into the template. */
1541 /* Now make the array of arrays and update the pointer to the array
1542 in the fat pointer. Note that it is the first field. */
1546 /* Get and validate any specified Component_Size, but if Packed,
1547 ignore it since the front end will have taken care of it. Also,
1548 allow sizes not a multiple of Storage_Unit if packed. */
1549 gnu_comp_size
1551 gnat_entity,
1559 /* If the component type is a RECORD_TYPE that has a self-referential
1560 size, use the maxium size. */
1567 {
1571 }
1577 /* If Component_Size is not already specified, annotate it with the
1578 size of the component. */
1588 gnu_max_size),
1592 {
1597 }
1599 /* If an alignment is specified, use it if valid. But ignore it for
1600 types that represent the unpacked base type for packed arrays. */
1603 {
1610 }
1616 /* The result type is an UNCONSTRAINED_ARRAY_TYPE that indicates the
1617 corresponding fat pointer. */
1624 /* If the maximum size doesn't overflow, use it. */
1627 {
1633 }
1637 debug_info_p);
1640 /* Create a record type for the object and its template and
1641 set the template at a negative offset. */
1653 /* Give the thin pointer type a name. */
1657 }
1663 /* This is the actual data type for array variables. Multidimensional
1664 arrays are implemented in the gnu tree as arrays of arrays. Note
1665 that for the moment arrays which have sparse enumeration subtypes as
1666 index components create sparse arrays, which is obviously space
1667 inefficient but so much easier to code for now.
1669 Also note that the subtype never refers to the unconstrained
1670 array type, which is somewhat at variance with Ada semantics.
1672 First check to see if this is simply a renaming of the array
1673 type. If so, the result is the array type. */
1678 else
1679 {
1682 int first_dim
1685 int next_dim
1687 Entity_Id gnat_ind_subtype;
1688 Entity_Id gnat_ind_base_subtype;
1693 tree gnu_max_size_unit;
1697 /* First create the gnu types for each index. Create types for
1698 debugging information to point to the index types if the
1699 are not integer types, have variable bounds, or are
1700 wider than sizetype. */
1703 gnat_ind_base_subtype
1709 {
1710 tree gnu_index_subtype
1712 tree gnu_min
1714 tree gnu_max
1716 tree gnu_base_subtype
1718 tree gnu_base_min
1720 tree gnu_base_max
1723 tree gnu_base_base_min
1725 tree gnu_base_base_max
1727 tree gnu_high;
1728 tree gnu_this_max;
1730 /* If the minimum and maximum values both overflow in
1731 SIZETYPE, but the difference in the original type
1732 does not overflow in SIZETYPE, ignore the overflow
1733 indications. */
1739 && (! TREE_OVERFLOW
1747 /* Similarly, if the range is null, use bounds of 1..0 for
1748 the sizetype bounds. */
1758 /* Now compute the size of this bound. We need to provide
1759 GCC with an upper bound to use but have to deal with the
1760 "superflat" case. There are three ways to do this. If we
1761 can prove that the array can never be superflat, we can
1762 just use the high bound of the index subtype. If we can
1763 prove that the low bound minus one can't overflow, we
1764 can do this as MAX (hb, lb - 1). Otherwise, we have to use
1765 the expression hb >= lb ? hb : lb - 1. */
1768 /* See if the base array type is already flat. If it is, we
1769 are probably compiling an ACVC test, but it will cause the
1770 code below to malfunction if we don't handle it specially. */
1778 /* If gnu_high is now an integer which overflowed, the array
1779 cannot be superflat. */
1786 else
1787 gnu_high
1788 = build_cond_expr
1796 /* Also compute the maximum size of the array. Here we
1797 see if any constraint on the index type of the base type
1798 can be used in the case of self-referential bound on
1799 the index type of the subtype. We look for a non-"infinite"
1800 and non-self-referential bound from any type involved and
1801 handle each bound separately. */
1828 gnu_this_max
1832 gnu_base_min)),
1833 size_zero_node);
1839 gnu_max_size
1853 }
1855 /* Then flatten: create the array of arrays. */
1859 /* One of the above calls might have caused us to be elaborated,
1860 so don't blow up if so. */
1862 {
1865 }
1867 /* Get and validate any specified Component_Size, but if Packed,
1868 ignore it since the front end will have taken care of it. Also,
1869 allow sizes not a multiple of Storage_Unit if packed. */
1870 gnu_comp_size
1872 gnat_entity,
1877 /* If the component type is a RECORD_TYPE that has a self-referential
1878 size, use the maxium size. */
1885 {
1890 }
1903 /* We don't want any array types shared for two reasons: first,
1904 we want to keep differently-named types distinct; second,
1905 setting TYPE_MULTI_ARRAY_TYPE of one type can clobber
1906 another. */
1909 {
1914 }
1916 /* If we are at file level and this is a multi-dimensional array, we
1917 need to make a variable corresponding to the stride of the
1918 inner dimensions. */
1920 {
1922 tree gnu_arr_type;
1928 {
1934 = elaborate_expression_1
1937 }
1938 }
1940 /* If we need to write out a record type giving the names of
1941 the bounds, do it now. */
1943 {
1946 tree gnu_field;
1952 {
1953 tree gnu_type_name
1960 integer_type_node,
1961 gnu_bound_rec_type,
1965 }
1968 }
1974 /* If our size depends on a placeholder and the maximum size doesn't
1975 overflow, use it. */
1981 {
1987 }
1989 /* Set our alias set to that of our base type. This gives all
1990 array subtypes the same alias set. */
1993 }
1995 /* If this is a packed type, make this type the same as the packed
1996 array type, but do some adjusting in the type first. */
1999 {
2000 Entity_Id gnat_index;
2001 tree gnu_inner_type;
2003 /* First finish the type we had been making so that we output
2004 debugging information for it */
2007 | (TYPE_QUAL_VOLATILE
2012 debug_info_p);
2016 /* Save it as our equivalent in case the call below elaborates
2017 this type again. */
2031 /* We need to point the type we just made to our index type so
2032 the actual bounds can be put into a template. */
2038 {
2040 {
2041 /* The TYPE_ACTUAL_BOUNDS field is also used for the modulus.
2042 If it is, we need to make another type. */
2044 {
2045 tree gnu_subtype;
2062 }
2065 }
2083 }
2084 }
2086 /* Abort if packed array with no packed array type field set. */
2093 /* Create the type for a string literal. */
2094 {
2095 Entity_Id gnat_full_type
2100 tree gnu_string_array_type
2102 tree gnu_string_index_type
2104 tree gnu_lower_bound
2109 tree gnu_upper_bound
2111 gnu_lower_bound,
2113 tree gnu_range_type
2116 tree gnu_index_type
2121 gnu_range_type);
2123 gnu_type
2125 gnu_index_type);
2126 }
2129 /* Record Types and Subtypes
2131 The following fields are defined on record types:
2133 Has_Discriminants True if the record has discriminants
2134 First_Discriminant Points to head of list of discriminants
2135 First_Entity Points to head of list of fields
2136 Is_Tagged_Type True if the record is tagged
2138 Implementation of Ada records and discriminated records:
2140 A record type definition is transformed into the equivalent of a C
2141 struct definition. The fields that are the discriminants which are
2142 found in the Full_Type_Declaration node and the elements of the
2143 Component_List found in the Record_Type_Definition node. The
2144 Component_List can be a recursive structure since each Variant of
2145 the Variant_Part of the Component_List has a Component_List.
2147 Processing of a record type definition comprises starting the list of
2148 field declarations here from the discriminants and the calling the
2149 function components_to_record to add the rest of the fields from the
2150 component list and return the gnu type node. The function
2151 components_to_record will call itself recursively as it traverses
2152 the tree. */
2155 #if 0
2157 {
2158 gnu_type
2159 = build_complex_type
2160 (get_unpadded_type
2163 (Component_List
2164 (Type_Definition
2167 /* ??? For now, don't use Complex if the real type is shorter than
2168 a word. */
2172 }
2173 #endif
2175 {
2178 Entity_Id gnat_field;
2179 tree gnu_field;
2181 tree gnu_get_parent;
2188 int is_extension
2192 /* See if all fields have a rep clause. Stop when we find one
2193 that doesn't. */
2202 /* If this is a record extension, go a level further to find the
2203 record definition. Also, verify we have a Parent_Subtype. */
2205 {
2212 }
2214 /* Make a node for the record. If we are not defining the record,
2215 suppress expanding incomplete types and save the node as the type
2216 for GNAT_ENTITY. We use the same RECORD_TYPE as was made
2217 for a dummy type and then show it's no longer a dummy. */
2227 {
2228 defer_incomplete_level++;
2233 debug_info_p);
2236 }
2238 /* If both a size and rep clause was specified, put the size in
2239 the record type now so that it can get the proper mode. */
2243 /* Always set the alignment here so that it can be used to
2244 set the mode, if it is making the alignment stricter. If
2245 it is invalid, it will be checked again below. If this is to
2246 be Atomic, choose a default alignment of a word. */
2254 /* If we have a Parent_Subtype, make a field for the parent. If
2255 this record has rep clauses, force the position to zero. */
2257 {
2258 tree gnu_parent;
2260 /* A major complexity here is that the parent subtype will
2261 reference our discriminants. But those must reference
2262 the parent component of this record. So here we will
2263 initialize each of those components to a COMPONENT_REF.
2264 The first operand of that COMPONENT_REF is another
2265 COMPONENT_REF which will be filled in below, once
2266 the parent type can be safely built. */
2271 NULL_TREE));
2278 save_gnu_tree
2282 gnu_get_parent,
2290 gnu_field_list
2300 }
2302 /* Add the fields for the discriminants into the record. */
2308 {
2309 /* If this is a record extension and this discriminant
2310 is the renaming of another discriminant, we've already
2311 handled the discriminant above. */
2316 gnu_field
2319 /* Make an expression using a PLACEHOLDER_EXPR from the
2320 FIELD_DECL node just created and link that with the
2321 corresponding GNAT defining identifier. Then add to the
2322 list of fields. */
2327 gnu_field),
2332 }
2334 /* Put the discriminants into the record (backwards), so we can
2335 know the appropriate discriminant to use for the names of the
2336 variants. */
2339 /* Add the listed fields into the record and finish up. */
2348 /* If this is an extension type, reset the tree for any
2349 inherited discriminants. Also remove the PLACEHOLDER_EXPR
2350 for non-inherited discriminants. */
2356 {
2360 else
2361 {
2365 }
2366 }
2368 /* If it is a tagged record force the type to BLKmode to insure
2369 that these objects will always be placed in memory. Do the
2370 same thing for limited record types. */
2375 /* Fill in locations of fields. */
2378 /* If there are any entities in the chain corresponding to
2379 components that we did not elaborate, ensure we elaborate their
2380 types if they are Itypes. */
2388 }
2392 /* If an equivalent type is present, that is what we should use.
2393 Otherwise, fall through to handle this like a record subtype
2394 since it may have constraints. */
2397 {
2401 }
2403 /* ... fall through ... */
2407 /* If Cloned_Subtype is Present it means this record subtype has
2408 identical layout to that type or subtype and we should use
2409 that GCC type for this one. The front end guarantees that
2410 the component list is shared. */
2412 {
2416 }
2418 /* Otherwise, first ensure the base type is elaborated. Then, if we are
2419 changing the type, make a new type with each field having the
2420 type of the field in the new subtype but having the position
2421 computed by transforming every discriminant reference according
2422 to the constraints. We don't see any difference between
2423 private and nonprivate type here since derivations from types should
2424 have been deferred until the completion of the private type. */
2425 else
2426 {
2428 tree gnu_base_type;
2429 tree gnu_orig_type;
2434 /* Get the base type initially for its alignment and sizes. But
2435 if it is a padded type, we do all the other work with the
2436 unpadded type. */
2445 {
2448 }
2450 /* When the type has discriminants, and these discriminants
2451 affect the shape of what it built, factor them in.
2453 If we are making a subtype of an Unchecked_Union (must be an
2454 Itype), just return the type.
2456 We can't just use Is_Constrained because private subtypes without
2457 discriminants of full types with discriminants with default
2458 expressions are Is_Constrained but aren't constrained! */
2466 {
2467 Entity_Id gnat_field;
2468 Entity_Id gnat_root_type;
2470 tree gnu_pos_list
2473 tree gnu_subst_list
2475 definition);
2476 tree gnu_temp;
2478 /* If this is a derived type, we may be seeing fields from any
2479 original records, so add those positions and discriminant
2480 substitutions to our lists. */
2484 {
2485 gnu_pos_list
2486 = compute_field_positions
2491 gnu_subst_list
2494 }
2506 {
2507 tree gnu_old_field
2508 = gnat_to_gnu_entity
2510 tree gnu_offset
2512 gnu_pos_list));
2515 tree gnu_field_type
2519 tree gnu_field;
2521 /* If there was a component clause, the field types must be
2522 the same for the type and subtype, so copy the data from
2523 the old field to avoid recomputation here. */
2526 {
2529 }
2531 /* If this was a bitfield, get the size from the old field.
2532 Also ensure the type can be placed into a bitfield. */
2534 {
2540 }
2550 /* If the size is now a constant, we can set it as the
2551 size of the field when we make it. Otherwise, we need
2552 to deal with it specially. */
2556 gnu_field
2557 = create_field_decl
2563 {
2568 SET_DECL_OFFSET_ALIGN
2574 bitsize_unit_node));
2576 }
2590 }
2594 /* Now set the size, alignment and alias set of the new type to
2595 match that of the old one, doing any substitutions, as
2596 above. */
2631 /* Recompute the mode of this record type now that we know its
2632 actual size. */
2635 /* Fill in locations of fields. */
2637 }
2639 /* If we've made a new type, record it and make an XVS type to show
2640 what this is a subtype of. Some debuggers require the XVS
2641 type to be output first, so do it in that order. */
2643 {
2645 {
2656 integer_type_node,
2657 gnu_subtype_marker,
2661 }
2667 gnu_type));
2671 }
2673 /* Otherwise, go down all the components in the new type and
2674 make them equivalent to those in the base type. */
2675 else
2682 get_gnu_tree
2684 }
2688 /* If we are not defining this entity, and we have incomplete
2689 entities being processed above us, make a dummy type and
2690 fill it in later. */
2692 {
2696 gnu_type
2697 = build_pointer_type
2701 debug_info_p);
2710 }
2712 /* ... fall through ... */
2719 {
2721 Entity_Id gnat_desig_full
2723 Incomplete_Or_Private_Kind))
2725 /* We want to know if we'll be seeing the freeze node for any
2726 incomplete type we may be pointing to. */
2727 int in_main_unit
2739 {
2741 {
2745 }
2747 Incomplete_Or_Private_Kind))
2749 }
2754 /* If either the designated type or its full view is an
2755 unconstrained array subtype, replace it with the type it's a
2756 subtype of. This avoids problems with multiple copies of
2757 unconstrained array types. */
2766 /* If we are pointing to an incomplete type whose completion is an
2767 unconstrained array, make a fat pointer type instead of a pointer
2768 to VOID. The two types in our fields will be pointers to VOID and
2769 will be replaced in update_pointer_to. Similiarly, if the type
2770 itself is a dummy type or an unconstrained array. Also make
2771 a dummy TYPE_OBJECT_RECORD_TYPE in case we have any thin
2772 pointers to it. */
2793 {
2794 tree gnu_old
2798 tree fields;
2800 /* Show the dummy we get will be a fat pointer. */
2803 /* If the call above got something that has a pointer, that
2804 pointer is our type. This could have happened either
2805 because the type was elaborated or because somebody
2806 else executed the code below. */
2809 {
2815 fields
2817 create_field_decl
2822 ptr_void_type_node,
2825 /* Make sure we can place this into a register. */
2836 }
2837 }
2839 /* If we already know what the full type is, use it. */
2844 /* Get the type of the thing we are to point to and build a pointer
2845 to it. If it is a reference to an incomplete or private type with a
2846 full view that is a record, make a dummy type node and get the
2847 actual type later when we have verified it is safe. */
2853 {
2856 }
2858 /* Likewise if we are pointing to a record or array and we are to defer
2859 elaborating incomplete types. We do this since this access type
2860 may be the full view of some private type. Note that the
2861 unconstrained array case is handled above. */
2869 {
2872 }
2874 {
2877 }
2878 else
2881 /* It is possible that the above call to gnat_to_gnu_type resolved our
2882 type. If so, just return it. */
2884 {
2887 }
2889 /* If we have a GCC type for the designated type, possibly
2890 modify it if we are pointing only to constant objects and then
2891 make a pointer to it. Don't do this for unconstrained arrays. */
2893 {
2896 gnu_desig_type
2902 }
2904 /* If we are not defining this object and we made a dummy pointer,
2905 save our current definition, evaluate the actual type, and replace
2906 the tentative type we made with the actual one. If we are to defer
2907 actually looking up the actual type, make an entry in the
2908 deferred list. */
2911 {
2912 tree gnu_old_type
2918 gnu_type
2919 = build_pointer_type
2920 (TYPE_OBJECT_RECORD_TYPE
2925 debug_info_p);
2932 else
2933 {
2941 }
2942 }
2943 }
2949 else
2950 /* The runtime representation is the equivalent type. */
2964 /* We treat this as identical to its base type; any constraint is
2965 meaningful only to the front end.
2967 The designated type must be elaborated as well, if it does
2968 not have its own freeze node. Designated (sub)types created
2969 for constrained components of records with discriminants are
2970 not frozen by the front end and thus not elaborated by gigi,
2971 because their use may appear before the base type is frozen,
2972 and because it is not clear that they are needed anywhere in
2973 Gigi. With the current model, there is no correct place where
2974 they could be elaborated. */
2981 {
2982 /* If we are not defining this entity, and we have incomplete
2983 entities being processed above us, make a dummy type and
2984 elaborate it later. */
2986 {
2989 tree gnu_ptr_type
2990 = build_pointer_type
2997 }
2998 else
3001 }
3006 /* Subprogram Entities
3008 The following access functions are defined for subprograms (functions
3009 or procedures):
3011 First_Formal The first formal parameter.
3012 Is_Imported Indicates that the subprogram has appeared in
3013 an INTERFACE or IMPORT pragma. For now we
3014 assume that the external language is C.
3015 Is_Inlined True if the subprogram is to be inlined.
3017 In addition for function subprograms we have:
3019 Etype Return type of the function.
3021 Each parameter is first checked by calling must_pass_by_ref on its
3022 type to determine if it is passed by reference. For parameters which
3023 are copied in, if they are Ada IN OUT or OUT parameters, their return
3024 value becomes part of a record which becomes the return type of the
3025 function (C function - note that this applies only to Ada procedures
3026 so there is no Ada return type). Additional code to store back the
3027 parameters will be generated on the caller side. This transformation
3028 is done here, not in the front-end.
3030 The intended result of the transformation can be seen from the
3031 equivalent source rewritings that follow:
3033 struct temp {int a,b};
3034 procedure P (A,B: IN OUT ...) is temp P (int A,B) {
3035 .. ..
3036 end P; return {A,B};
3037 }
3038 procedure call
3040 {
3041 temp t;
3042 P(X,Y); t = P(X,Y);
3043 X = t.a , Y = t.b;
3044 }
3046 For subprogram types we need to perform mainly the same conversions to
3047 GCC form that are needed for procedures and function declarations. The
3048 only difference is that at the end, we make a type declaration instead
3049 of a function declaration. */
3054 {
3055 /* The first GCC parameter declaration (a PARM_DECL node). The
3056 PARM_DECL nodes are chained through the TREE_CHAIN field, so this
3057 actually is the head of this parameter list. */
3059 /* The type returned by a function. If the subprogram is a procedure
3060 this type should be void_type_node. */
3062 /* List of fields in return type of procedure with copy in copy out
3063 parameters. */
3065 /* Non-null for subprograms containing parameters passed by copy in
3066 copy out (Ada IN OUT or OUT parameters not passed by reference),
3067 in which case it is the list of nodes used to specify the values of
3068 the in out/out parameters that are returned as a record upon
3069 procedure return. The TREE_PURPOSE of an element of this list is
3070 a field of the record and the TREE_VALUE is the PARM_DECL
3071 corresponding to that field. This list will be saved in the
3072 TYPE_CI_CO_LIST field of the FUNCTION_TYPE node we create. */
3074 Entity_Id gnat_param;
3077 int extern_flag
3088 /* A parameter may refer to this type, so defer completion
3089 of any incomplete types. */
3092 /* If the subprogram has an alias, it is probably inherited, so
3093 we can use the original one. If the original "subprogram"
3094 is actually an enumeration literal, it may be the first use
3095 of its type, so we must elaborate that type now. */
3097 {
3104 /* Elaborate any Itypes in the parameters of this entity. */
3112 }
3117 /* If this function returns by reference, make the actual
3118 return type of this function the pointer and mark the decl. */
3120 {
3124 }
3126 /* If we are supposed to return an unconstrained array,
3127 actually return a fat pointer and make a note of that. Return
3128 a pointer to an unconstrained record of variable size. */
3130 {
3133 }
3135 /* If the type requires a transient scope, the result is allocated
3136 on the secondary stack, so the result type of the function is
3137 just a pointer. */
3139 {
3142 }
3144 /* If the type is a padded type and the underlying type would not
3145 be passed by reference or this function has a foreign convention,
3146 return the underlying type. */
3154 /* Look at all our parameters and get the type of
3155 each. While doing this, build a copy-out structure if
3156 we need one. */
3161 {
3171 /* See if a Mechanism was supplied that forced this
3172 parameter to be passed one way or another. */
3176 ;
3184 {
3190 else
3192 }
3193 else
3196 /* If this is either a foreign function or if the
3197 underlying type won't be passed by refererence, strip off
3198 possible padding type. */
3206 /* If this is an IN parameter it is read-only, so make a variant
3207 of the type that is read-only.
3209 ??? However, if this is an unconstrained array, that type can
3210 be very complex. So skip it for now. Likewise for any other
3211 self-referential type. */
3217 gnu_param_type
3222 /* For foreign conventions, pass arrays as a pointer to the
3223 underlying type. First check for unconstrained array and get
3224 the underlying array. Then get the component type and build
3225 a pointer to it. */
3228 gnu_param_type
3233 gnu_param_type
3234 = build_pointer_type
3237 gnat_entity));
3240 && ! req_by_copy
3242 {
3243 /* Strip off any multi-dimensional entries, then strip
3244 off the last array to get the component type. */
3253 gnu_param_type
3259 }
3261 /* Fat pointers are passed as thin pointers for foreign
3262 conventions. */
3265 gnu_param_type
3269 /* If we must pass or were requested to pass by reference, do so.
3270 If we were requested to pass by copy, do so.
3271 Otherwise, for foreign conventions, pass all in out parameters
3272 or aggregates by reference. For COBOL and Fortran, pass
3273 all integer and FP types that way too. For Convention Ada,
3274 use the standard Ada default. */
3276 || (! req_by_copy
3286 /* For convention Ada, see if we pass by reference
3287 by default. */
3290 {
3293 }
3301 /* If this is an OUT parameter that isn't passed by reference
3302 and isn't a pointer or aggregate, we don't make a PARM_DECL
3303 for it. Instead, it will be a VAR_DECL created when we process
3304 the procedure. For the special parameter of Valued_Procedure,
3305 never pass it in. */
3308 || (! by_descr_p
3312 else
3313 {
3315 gnu_param
3316 = create_param_decl
3318 by_ref_p || by_component_ptr_p
3330 /* If a parameter is a pointer, this function may modify
3331 memory through it and thus shouldn't be considered
3332 a pure function. Also, the memory may be modified
3333 between two calls, so they can't be CSE'ed. The latter
3334 case also handles by-ref parameters. */
3338 }
3341 {
3343 {
3350 }
3358 gnu_return_list);
3359 }
3360 }
3362 /* Do not compute record for out parameters if subprogram is
3363 stubbed since structures are incomplete for the back-end. */
3369 /* If we have a CICO list but it has only one entry, we convert
3370 this function into a function that simply returns that one
3371 object. */
3376 {
3386 }
3388 /* Both lists ware built in reverse. */
3392 gnu_type
3395 returns_by_ref,
3398 /* ??? For now, don't consider nested functions pure. */
3402 gnu_type
3408 /* Top-level or external functions need to have an assembler name.
3409 This is passed to create_subprog_decl through the ext_name argument.
3410 For Pragma Interface subprograms with no Pragma Interface_Name, the
3411 simple name already in entity_name is correct, and this is what is
3412 gotten when ext_name is NULL. If Interface_Name is specified, then
3413 the name is extracted from the N_String_Literal node containing the
3414 string specified in the Pragma. If there is no Pragma Interface,
3415 then the Ada fully qualified name is created. */
3423 /* If we are defining the subprogram and it has an Address clause
3424 we must get the address expression from the saved GCC tree for the
3425 subprogram if it has a Freeze_Node. Otherwise, we elaborate
3426 the address expression here since the front-end has guaranteed
3427 in that case that the elaboration has no effects. If there is
3428 an Address clause and we are not defining the object, just
3429 make it a constant. */
3431 {
3435 gnu_address
3446 gnu_decl
3451 }
3456 debug_info_p);
3457 else
3458 {
3465 }
3466 }
3477 /* If this type does not have a full view in the unit we are
3478 compiling, then just get the type from its Etype. */
3480 {
3481 /* If this is an incomplete type with no full view, it must
3482 be a Taft Amendement type, so just return a dummy type. */
3489 else
3490 {
3494 }
3497 }
3499 /* Otherwise, if we are not defining the type now, get the
3500 type from the full view. But always get the type from the full
3501 view for define on use types, since otherwise we won't see them! */
3508 {
3513 }
3515 /* For incomplete types, make a dummy type entry which will be
3516 replaced later. */
3519 /* Save this type as the full declaration's type so we can do any needed
3520 updates when we see it. */
3524 debug_info_p);
3528 /* Simple class_wide types are always viewed as their root_type
3529 by Gigi unless an Equivalent_Type is specified. */
3533 else
3545 else
3557 /* Nothing at all to do here, so just return an ERROR_MARK and claim
3558 we've already saved it, so we don't try to. */
3565 }
3567 /* If we had a case where we evaluated another type and it might have
3568 defined this one, handle it here. */
3570 {
3573 }
3575 /* If we are processing a type and there is either no decl for it or
3576 we just made one, do some common processing for the type, such as
3577 handling alignment and possible padding. */
3580 {
3587 /* ??? Don't set the size for a String_Literal since it is either
3588 confirming or we don't handle it properly (if the low bound is
3589 non-constant). */
3594 /* If a size was specified, see if we can make a new type of that size
3595 by rearranging the type, for example from a fat to a thin pointer. */
3597 {
3598 gnu_type
3605 }
3607 /* If the alignment hasn't already been processed and this is
3608 not an unconstrained array, see if an alignment is specified.
3609 If not, we pick a default alignment for atomic objects. */
3611 ;
3625 /* See if we need to pad the type. If we did, and made a record,
3626 the name of the new type may be changed. So get it back for
3627 us when we make the new TYPE_DECL below. */
3632 {
3636 }
3640 /* If we are at global level, GCC will have applied variable_size to
3641 the type, but that won't have done anything. So, if it's not
3642 a constant or self-referential, call elaborate_expression_1 to
3643 make a variable for the size rather than calculating it each time.
3644 Handle both the RM size and the actual size. */
3649 {
3659 {
3675 }
3676 else
3677 {
3688 }
3689 }
3691 /* If this is a record type or subtype, call elaborate_expression_1 on
3692 any field position. Do this for both global and local types.
3693 Skip any fields that we haven't made trees for to avoid problems with
3694 class wide types. */
3699 {
3709 }
3713 | (TYPE_QUAL_VOLATILE
3723 {
3727 debug_info_p);
3728 }
3729 else
3731 }
3734 {
3737 /* Back-annotate the Alignment of the type if not already in the
3738 tree. Likewise for sizes. */
3744 {
3745 /* If the size is self-referential, we annotate the maximum
3746 value of that size. */
3753 }
3757 }
3766 /* If this decl is really indirect, adjust it. */
3770 /* If we haven't already, associate the ..._DECL node that we just made with
3771 the input GNAT entity node. */
3775 /* If this is an enumeral or floating-point type, we were not able to set
3776 the bounds since they refer to the type. These bounds are always static.
3778 For enumeration types, also write debugging information and declare the
3779 enumeration literal table, if needed. */
3783 {
3786 /* If this is a padded type, we need to use the underlying type. */
3791 /* If this is a floating point type and we haven't set a floating
3792 point type yet, use this in the evaluation of the bounds. */
3802 {
3805 /* Since this has both a typedef and a tag, avoid outputting
3806 the name twice. */
3809 }
3810 }
3812 /* If we deferred processing of incomplete types, re-enable it. If there
3813 were no other disables and we have some to process, do so. */
3816 {
3822 {
3829 }
3830 }
3832 /* If we are not defining this type, see if it's in the incomplete list.
3833 If so, handle that list entry now. */
3835 {
3840 {
3844 }
3845 }
3848 force_global--;
3857 }
3858 \f
3859 /* Given GNAT_ENTITY, elaborate all expressions that are required to
3860 be elaborated at the point of its definition, but do nothing else. */
3862 void
3864 Entity_Id gnat_entity;
3865 {
3867 {
3874 {
3878 /* ??? Tests for avoiding static constaint error expression
3879 is needed until the front stops generating bogus conversions
3880 on bounds of real types. */
3889 }
3892 {
3896 /* If this is a record extension, go a level further to find the
3897 record definition. */
3900 }
3910 {
3911 Node_Id gnat_discriminant_expr;
3912 Entity_Id gnat_field;
3915 gnat_discriminant_expr
3920 /* ??? For now, ignore access discriminants. */
3923 gnat_entity,
3925 }
3928 }
3929 }
3930 \f
3931 /* Mark GNAT_ENTITY as going out of scope at this point. Recursively mark
3932 any entities on its entity chain similarly. */
3934 void
3936 Entity_Id gnat_entity;
3937 {
3938 Entity_Id gnat_sub_entity;
3941 /* If this has an entity list, process all in the list. */
3958 /* Now clear this if it has been defined, but only do so if it isn't
3959 a subprogram or parameter. We could refine this, but it isn't
3960 worth it. If this is statically allocated, it is supposed to
3961 hang around out of cope. */
3964 {
3967 }
3968 }
3969 \f
3970 /* Return a TREE_LIST describing the substitutions needed to reflect
3971 discriminant substitutions from GNAT_SUBTYPE to GNAT_TYPE and add
3972 them to GNU_LIST. If GNAT_TYPE is not specified, use the base type
3973 of GNAT_SUBTYPE. The substitions can be in any order. TREE_PURPOSE
3974 gives the tree for the discriminant and TREE_VALUES is the replacement
3975 value. They are in the form of operands to substitute_in_expr.
3976 DEFINITION is as in gnat_to_gnu_entity. */
3978 static tree
3980 Entity_Id gnat_subtype;
3981 Entity_Id gnat_type;
3982 tree gnu_list;
3984 {
3985 Entity_Id gnat_discrim;
3986 Node_Id gnat_value;
3997 /* Ignore access discriminants. */
4000 elaborate_expression
4004 gnu_list);
4007 }
4008 \f
4009 /* For the following two functions: for each GNAT entity, the GCC
4010 tree node used as a dummy for that entity, if any. */
4014 /* Initialize the above table. */
4016 void
4018 {
4019 Node_Id gnat_node;
4028 }
4030 /* Make a dummy type corresponding to GNAT_TYPE. */
4032 tree
4034 Entity_Id gnat_type;
4035 {
4036 Entity_Id gnat_underlying;
4037 tree gnu_type;
4039 /* Find a full type for GNAT_TYPE, taking into account any class wide
4040 types. */
4050 ;
4052 /* If it there already a dummy type, use that one. Else make one. */
4056 /* If this is a record, make this a RECORD_TYPE or UNION_TYPE; else make
4057 it a VOID_TYPE. */
4061 else
4073 }
4074 \f
4075 /* Return 1 if the size represented by GNU_SIZE can be handled by an
4076 allocation. If STATIC_P is non-zero, consider only what can be
4077 done with a static allocation. */
4079 static int
4081 tree gnu_size;
4083 {
4084 /* If this is not a static allocation, the only case we want to forbid
4085 is an overflowing size. That will be converted into a raise a
4086 Storage_Error. */
4091 /* Otherwise, we need to deal with both variable sizes and constant
4092 sizes that won't fit in a host int. */
4094 }
4095 \f
4096 /* Return a list of attributes for GNAT_ENTITY, if any. */
4100 Entity_Id gnat_entity;
4101 {
4103 Node_Id gnat_temp;
4108 {
4118 {
4120 (gnat_to_gnu
4127 (gnat_to_gnu
4128 (Expression
4131 }
4134 {
4153 }
4160 attr->error_point
4164 }
4167 }
4168 \f
4169 /* Get the unpadded version of a GNAT type. */
4171 tree
4173 Entity_Id gnat_entity;
4174 {
4181 }
4182 \f
4183 /* Called when we need to protect a variable object using a save_expr. */
4185 tree
4187 tree gnu_operand;
4188 Node_Id gnat_node;
4189 {
4195 /* If we will be generating code, make sure we are at the proper
4196 line number. */
4204 else
4206 }
4207 \f
4208 /* Given a GNAT tree GNAT_EXPR, for an expression which is a value within a
4209 type definition (either a bound or a discriminant value) for GNAT_ENTITY,
4210 return the GCC tree to use for that expression. GNU_NAME is the
4211 qualification to use if an external name is appropriate and DEFINITION is
4212 nonzero if this is a definition of GNAT_ENTITY. If NEED_VALUE is nonzero,
4213 we need a result. Otherwise, we are just elaborating this for
4214 side-effects. If NEED_DEBUG is nonzero we need the symbol for debugging
4215 purposes even if it isn't needed for code generation. */
4217 static tree
4220 Node_Id gnat_expr;
4221 Entity_Id gnat_entity;
4222 tree gnu_name;
4226 {
4227 tree gnu_expr;
4229 /* If we already elaborated this expression (e.g., it was involved
4230 in the definition of a private type), use the old value. */
4234 /* If we don't need a value and this is static or a discriment, we
4235 don't need to do anything. */
4242 /* Otherwise, convert this tree to its GCC equivalant. */
4243 gnu_expr
4247 /* Save the expression in case we try to elaborate this entity again.
4248 Since this is not a DECL, don't check it. If this is a constant,
4249 don't save it since GNAT_EXPR might be used more than once. Also,
4250 don't save if it's a discriminant. */
4255 }
4257 /* Similar, but take a GNU expression. */
4259 static tree
4261 need_debug)
4262 Node_Id gnat_expr;
4263 Entity_Id gnat_entity;
4264 tree gnu_expr;
4265 tree gnu_name;
4268 {
4274 /* Strip any conversions to see if the expression is a readonly variable.
4275 ??? This really should remain readonly, but we have to think about
4276 the typing of the tree here. */
4281 /* In most cases, we won't see a naked FIELD_DECL here because a
4282 discriminant reference will have been replaced with a COMPONENT_REF
4283 when the type is being elaborated. However, there are some cases
4284 involving child types where we will. So convert it to a COMPONENT_REF
4285 here. We have to hope it will be at the highest level of the
4286 expression in these cases. */
4290 gnu_expr);
4292 /* If GNU_EXPR is neither a placeholder nor a constant, nor a variable
4293 that is a constant, make a variable that is initialized to contain the
4294 bound when the package containing the definition is elaborated. If
4295 this entity is defined at top level and a bound or discriminant value
4296 isn't a constant or a reference to a discriminant, replace the bound
4297 by the variable; otherwise use a SAVE_EXPR if needed. Note that we
4298 rely here on the fact that an expression cannot contain both the
4299 discriminant and some other variable. */
4306 /* If this is a static expression or contains a discriminant, we don't
4307 need the variable for debugging (and can't elaborate anyway if a
4308 discriminant). */
4314 /* Now create the variable if we need it. */
4316 {
4318 gnu_decl
4323 }
4325 /* We only need to use this variable if we are in global context since GCC
4326 can do the right thing in the local case. */
4329 else
4331 }
4332 \f
4333 /* Create a record type that contains a field of TYPE with a starting bit
4334 position so that it is aligned to ALIGN bits and is SIZE bytes long. */
4336 tree
4338 tree type;
4340 tree size;
4341 {
4346 place));
4355 /* The bit position is obtained by "and"ing the alignment minus 1
4356 with the two's complement of the address and multiplying
4357 by the number of bits per unit. Do all this in sizetype. */
4363 size_addr_place),
4366 bitsize_unit_node);
4377 bitsize_unit_node),
4383 }
4384 \f
4385 /* TYPE is a RECORD_TYPE with BLKmode that's being used as the field
4386 type of a packed record. See if we can rewrite it as a record that has
4387 a non-BLKmode type, which we can pack tighter. If so, return the
4388 new type. If not, return the original type. */
4390 static tree
4392 tree type;
4393 {
4396 tree old_field;
4398 /* Copy the name and flags from the old type to that of the new and set
4399 the alignment to try for an integral type. */
4409 /* Now copy the fields, keeping the position and size. */
4412 {
4413 tree new_field
4426 }
4430 }
4431 \f
4432 /* Ensure that TYPE has SIZE and ALIGN. Make and return a new padded type
4433 if needed. We have already verified that SIZE and TYPE are large enough.
4435 GNAT_ENTITY and NAME_TRAILER are used to name the resulting record and
4436 to issue a warning.
4438 IS_USER_TYPE is nonzero if we must be sure we complete the original type.
4440 DEFINITION is nonzero if this type is being defined.
4442 SAME_RM_SIZE is nonzero if the RM_Size of the resulting type is to be
4443 set to its TYPE_SIZE; otherwise, it's set to the RM_Size of the original
4444 type. */
4446 static tree
4449 tree type;
4450 tree size;
4452 Entity_Id gnat_entity;
4457 {
4459 tree record;
4460 tree field;
4462 /* If TYPE is a padded type, see if it agrees with any size and alignment
4463 we were given. If so, return the original type. Otherwise, strip
4464 off the padding, since we will either be returning the inner type
4465 or repadding it. If no size or alignment is specified, use that of
4466 the original padded type. */
4469 {
4486 }
4488 /* If the size is either not being changed or is being made smaller (which
4489 is not done here (and is only valid for bitfields anyway), show the size
4490 isn't changing. Likewise, clear the alignment if it isn't being
4491 changed. Then return if we aren't doing anything. */
4505 /* We used to modify the record in place in some cases, but that could
4506 generate incorrect debugging information. So make a new record
4507 type and name. */
4513 /* If we were making a type, complete the original type and give it a
4514 name. */
4522 /* If we are changing the alignment and the input type is a record with
4523 BLKmode and a small constant size, try to make a form that has an
4524 integral mode. That might allow this record to have an integral mode,
4525 which will be much more efficient. There is no point in doing this if a
4526 size is specified unless it is also smaller than the biggest alignment
4527 and it is incorrect to do this if the size of the original type is not a
4528 multiple of the alignment. */
4548 bitsize_unit_node));
4555 /* Keep the RM_Size of the padded record as that of the old record
4556 if requested. */
4559 /* Unless debugging information isn't being written for the input type,
4560 write a record that shows what we are a subtype of and also make a
4561 variable that indicates our size, if variable. */
4566 {
4585 }
4593 /* If the size was widened explicitly, maybe give a warning. */
4599 {
4612 /* Generate message only for entities that come from source, since
4613 if we have an entity created by expansion, the message will be
4614 generated for some other corresponding source entity. */
4617 gnat_entity,
4624 }
4627 }
4628 \f
4629 /* Given a GNU tree and a GNAT list of choices, generate an expression to test
4630 the value passed against the list of choices. */
4632 tree
4634 tree operand;
4635 Node_Id choices;
4636 {
4637 Node_Id choice;
4638 Node_Id gnat_temp;
4643 {
4645 {
4650 /* There's no good type to use here, so we might as well use
4651 integer_type_node. */
4652 this_test
4666 this_test
4676 /* This represents either a subtype range, an enumeration
4677 literal, or a constant Ekind says which. If an enumeration
4678 literal or constant, fall through to the next case. */
4681 {
4687 this_test
4694 }
4695 /* ... fall through ... */
4700 single);
4709 }
4713 }
4716 }
4717 \f
4718 /* Return a GCC tree for a field corresponding to GNAT_FIELD to be
4719 placed in GNU_RECORD_TYPE.
4721 PACKED is 1 if the enclosing record is packed and -1 if the enclosing
4722 record has a Component_Alignment of Storage_Unit.
4724 DEFINITION is nonzero if this field is for a record being defined. */
4726 static tree
4728 Entity_Id gnat_field;
4729 tree gnu_record_type;
4732 {
4738 tree gnu_field;
4739 int needs_strict_alignment
4743 /* If this field requires strict alignment pretend it isn't packed. */
4747 /* For packed records, this is one of the few occasions on which we use
4748 the official RM size for discrete or fixed-point components, instead
4749 of the normal GNAT size stored in Esize. See description in Einfo:
4750 "Handling of Type'Size Values" for further details. */
4760 /* If we are packing this record and the field type is also a record
4761 that's BLKmode and with a small constant size, see if we can get a
4762 better form of the type that allows more packing. If we can, show
4763 a size was specified for it if there wasn't one so we know to
4764 make this a bitfield and avoid making things wider. */
4769 {
4774 }
4777 {
4782 /* Ensure the position does not overlap with the parent subtype,
4783 if there is one. */
4785 {
4786 tree gnu_parent
4792 {
4793 post_error_ne_tree
4797 }
4798 }
4800 /* If this field needs strict alignment, ensure the record is
4801 sufficiently aligned and that that position and size are
4802 consistent with the alignment. */
4804 {
4811 /* If Atomic, the size must match exactly and if aliased, the size
4812 must not be less than the rounded size. */
4815 {
4816 post_error_ne_tree
4822 }
4827 {
4828 post_error_ne_tree
4831 gnu_min_size);
4833 }
4838 {
4840 post_error_ne_num
4846 post_error_ne_num
4852 post_error_ne_num
4856 else
4860 }
4862 /* If an error set the size to zero, show we have no position
4863 either. */
4866 }
4873 bitsize_unit_node))))
4874 {
4875 /* Try to see if we can make this a packable type. If we
4876 can, it's OK. */
4881 {
4886 }
4887 }
4888 }
4890 /* If the record has rep clauses and this is the tag field, make a rep
4891 clause for it as well. */
4894 {
4897 }
4899 /* We need to make the size the maximum for the type if it is
4900 self-referential and an unconstrained type. */
4908 /* If no size is specified (or if there was an error), don't specify a
4909 position. */
4912 else
4913 {
4914 /* Unless this field is aliased, we can remove any left-justified
4915 modular type since it's only needed in the unchecked conversion
4916 case, which doesn't apply here. */
4922 gnu_field_type
4927 }
4945 }
4946 \f
4947 /* Return a GCC tree for a record type given a GNAT Component_List and a chain
4948 of GCC trees for fields that are in the record and have already been
4949 processed. When called from gnat_to_gnu_entity during the processing of a
4950 record type definition, the GCC nodes for the discriminants will be on
4951 the chain. The other calls to this function are recursive calls from
4952 itself for the Component_List of a variant and the chain is empty.
4954 PACKED is 1 if this is for a record with "pragma pack" and -1 is this is
4955 for a record type with "pragma component_alignment (storage_unit)".
4957 FINISH_RECORD is nonzero if this call will supply all of the remaining
4958 fields of the record.
4960 P_GNU_REP_LIST, if nonzero, is a pointer to a list to which each field
4961 with a rep clause is to be added. If it is nonzero, that is all that
4962 should be done with such fields.
4964 CANCEL_ALIGNMENT, if nonzero, means the alignment should be zeroed
4965 before laying out the record. This means the alignment only serves
4966 to force fields to be bitfields, but not require the record to be
4967 that aligned. This is used for variants.
4969 ALL_REP, if nonzero, means that a rep clause was found for all the
4970 fields. This simplifies the logic since we know we're not in the mixed
4971 case.
4973 The processing of the component list fills in the chain with all of the
4974 fields of the record and then the record type is finished. */
4976 static void
4979 tree gnu_record_type;
4980 Node_Id component_list;
4981 tree gnu_field_list;
4987 {
4988 Node_Id component_decl;
4989 Entity_Id gnat_field;
4990 Node_Id variant_part;
4991 Node_Id variant;
4996 /* For each variable within each component declaration create a GCC field
4997 and add it to the list, skipping any pragmas in the list. */
5003 {
5008 else
5009 {
5013 /* If this is the _Tag field, put it before any discriminants,
5014 instead of after them as is the case for all other fields. */
5017 else
5018 {
5021 }
5022 }
5025 }
5027 /* At the end of the component list there may be a variant part. */
5030 /* If this is an unchecked union, each variant must have exactly one
5031 component, each of which becomes one component of this union. */
5036 {
5037 component_decl
5041 definition);
5045 }
5047 /* We create a QUAL_UNION_TYPE for the variant part since the variants are
5048 mutually exclusive and should go in the same memory. To do this we need
5049 to treat each variant as a record whose elements are created from the
5050 component list for the variant. So here we create the records from the
5051 lists for the variants and put them all into the QUAL_UNION_TYPE. */
5053 {
5055 Node_Id variant;
5057 tree gnu_union_field;
5060 tree gnu_var_name
5061 = concat_id_with_name
5075 {
5077 tree gnu_inner_name;
5078 tree gnu_qual;
5086 /* Set the alignment of the inner type in case we need to make
5087 inner objects into bitfields, but then clear it out
5088 so the record actually gets only the alignment required. */
5105 }
5107 /* We can delete any empty variants from the end. This may leave none
5108 left. Note we cannot delete variants from anywhere else. */
5113 /* Only make the QUAL_UNION_TYPE if there are any non-empty variants. */
5115 {
5119 gnu_union_field
5121 packed,
5128 }
5129 }
5131 /* Scan GNU_FIELD_LIST and see if any fields have rep clauses. If they
5132 do, pull them out and put them into GNU_OUR_REP_LIST. We have to do this
5133 in a separate pass since we want to handle the discriminants but can't
5134 play with them until we've used them in debugging data above.
5136 ??? Note: if we then reorder them, debugging information will be wrong,
5137 but there's nothing that can be done about this at the moment. */
5140 {
5142 {
5147 else
5153 }
5154 else
5155 {
5158 }
5159 }
5161 /* If we have any items in our rep'ed field list, it is not the case that all
5162 the fields in the record have rep clauses, and P_REP_LIST is nonzero,
5163 set it and ignore the items. Otherwise, sort the fields by bit position
5164 and put them into their own record if we have any fields without
5165 rep clauses. */
5169 {
5170 tree gnu_rep_type
5176 /* Set DECL_SECTION_NAME to increasing integers so we have a
5177 stable sort. */
5180 {
5183 }
5187 /* Put the fields in the list in order of increasing position, which
5188 means we start from the end. */
5191 {
5196 }
5199 {
5205 }
5206 else
5207 {
5210 }
5211 }
5218 }
5219 \f
5220 /* Called via qsort from the above. Returns -1, 1, depending on the
5221 bit positions and ordinals of the two fields. */
5223 static int
5227 {
5232 return
5237 else
5239 }
5240 \f
5241 /* Given GNU_SIZE, a GCC tree representing a size, return a Uint to be
5242 placed into an Esize, Component_Bit_Offset, or Component_Size value
5243 in the GNAT tree. */
5245 static Uint
5247 tree gnu_size;
5248 {
5250 TCode tcode;
5255 /* If we do not return inside this switch, TCODE will be set to the
5256 code to use for a Create_Node operand and LEN (set above) will be
5257 the number of recursive calls for us to make. */
5260 {
5265 /* This may have come from a conversion from some smaller type,
5266 so ensure this is in bitsizetype. */
5269 /* For negative values, use NEGATE_EXPR of the supplied value. */
5271 {
5272 /* The rediculous code below is to handle the case of the largest
5273 negative integer. */
5276 tree temp;
5279 {
5280 negative_size
5283 bitsize_one_node));
5285 }
5292 }
5299 /* This peculiar test is to make sure that the size fits in an int
5300 on machines where HOST_WIDE_INT is not "int". */
5303 else
5307 /* The only case we handle here is a simple discriminant reference. */
5315 else
5321 /* Now just list the operations we handle. */
5352 }
5354 /* Now get each of the operands that's relevant for this code. If any
5355 cannot be expressed as a repinfo node, say we can't. */
5360 {
5364 }
5367 }
5369 /* Given GNAT_ENTITY, a record type, and GNU_TYPE, its corresponding
5370 GCC type, set Component_Bit_Offset and Esize to the position and size
5371 used by Gigi. */
5373 static void
5375 Entity_Id gnat_entity;
5376 tree gnu_type;
5377 {
5378 tree gnu_list;
5379 tree gnu_entry;
5380 Entity_Id gnat_field;
5382 /* We operate by first making a list of all field and their positions
5383 (we can get the sizes easily at any time) by a recursive call
5384 and then update all the sizes into the tree. */
5395 gnu_list)))
5396 {
5397 Set_Component_Bit_Offset
5405 }
5406 }
5408 /* Scan all fields in GNU_TYPE and build entries where TREE_PURPOSE is
5409 the FIELD_DECL and TREE_VALUE a TREE_LIST with TREE_PURPOSE being the
5410 byte position and TREE_VALUE being the bit position. GNU_POS is to
5411 be added to the position, GNU_BITPOS to the bit position, and GNU_LIST
5412 is the entries so far. */
5414 static tree
5416 tree gnu_type;
5417 tree gnu_list;
5418 tree gnu_pos;
5419 tree gnu_bitpos;
5420 {
5421 tree gnu_field;
5426 {
5432 gnu_result
5435 gnu_result);
5438 gnu_result
5441 }
5444 }
5445 \f
5446 /* UINT_SIZE is a Uint giving the specified size for an object of GNU_TYPE
5447 corresponding to GNAT_OBJECT. If size is valid, return a tree corresponding
5448 to its value. Otherwise return 0. KIND is VAR_DECL is we are specifying
5449 the size for an object, TYPE_DECL for the size of a type, and FIELD_DECL
5450 for the size of a field. COMPONENT_P is true if we are being called
5451 to process the Component_Size of GNAT_OBJECT. This is used for error
5452 message handling and to indicate to use the object size of GNU_TYPE.
5453 ZERO_OK is nonzero if a size of zero is permitted; if ZERO_OK is zero,
5454 it means that a size of zero should be treated as an unspecified size. */
5456 static tree
5458 Uint uint_size;
5459 tree gnu_type;
5460 Entity_Id gnat_object;
5464 {
5465 Node_Id gnat_error_node;
5466 tree type_size
5468 tree size;
5483 else
5486 /* Don't give errors on packed array types; we'll be giving the error on
5487 the type itself soon enough. */
5491 /* Get the size as a tree. Return 0 if none was specified, either because
5492 Esize was not Present or if the specified size was zero. Give an error
5493 if a size was specified, but cannot be represented as in sizetype. If
5494 the size is negative, it was a back-annotation of a variable size and
5495 should be treated as not specified. */
5501 {
5505 else
5509 }
5511 /* Ignore a negative size since that corresponds to our back-annotation.
5512 Also ignore a zero size unless a size clause exists. */
5516 /* The size of objects is always a multiple of a byte. */
5519 bitsize_unit_node)))
5520 {
5524 else
5528 }
5530 /* If this is an integral type, the front-end has verified the size, so we
5531 need not do it here (which would entail checking against the bounds).
5532 However, if this is an aliased object, it may not be smaller than the
5533 type of the object. */
5538 /* If the object is a record that contains a template, add the size of
5539 the template to the specified size. */
5544 /* If the size of the object is a constant, the new size must not be
5545 smaller. */
5549 {
5551 post_error_ne_tree
5554 else
5561 post_error_ne_tree_2
5571 }
5574 }
5575 \f
5576 /* Similarly, but both validate and process a value of RM_Size. This
5577 routine is only called for types. */
5579 static void
5581 Uint uint_size;
5582 tree gnu_type;
5583 Entity_Id gnat_entity;
5584 {
5585 /* Only give an error if a Value_Size clause was explicitly given.
5586 Otherwise, we'd be duplicating an error on the Size clause. */
5587 Node_Id gnat_attr_node
5590 tree size;
5592 /* Get the size as a tree. Do nothing if none was specified, either
5593 because RM_Size was not Present or if the specified size was zero.
5594 Give an error if a size was specified, but cannot be represented as
5595 in sizetype. */
5601 {
5604 gnat_entity);
5607 }
5609 /* Ignore a negative size since that corresponds to our back-annotation.
5610 Also ignore a zero size unless a size clause exists, a Value_Size
5611 clause exists, or this is an integer type, in which case the
5612 front end will have always set it. */
5619 /* If the old size is self-referential, get the maximum size. */
5624 /* If the size of the object is a constant, the new size must not be
5625 smaller (the front end checks this for scalar types). */
5630 {
5632 post_error_ne_tree
5637 }
5639 /* Otherwise, set the RM_Size. */
5650 }
5651 \f
5652 /* Given a type TYPE, return a new type whose size is appropriate for SIZE.
5653 If TYPE is the best type, return it. Otherwise, make a new type. We
5654 only support new integral and pointer types. BIASED_P is nonzero if
5655 we are making a biased type. */
5657 static tree
5659 tree type;
5660 tree size_tree;
5662 {
5663 tree new_type;
5666 /* If size indicates an error, just return TYPE to avoid propagating the
5667 error. Likewise if it's too large to represent. */
5673 {
5676 /* Only do something if the type is not already the proper size and is
5677 not a packed array type. */
5702 /* Do something if this is a fat pointer, in which case we
5703 may need to return the thin pointer. */
5705 return
5706 build_pointer_type
5711 /* Only do something if this is a thin pointer, in which case we
5712 may need to return the fat pointer. */
5714 return
5721 }
5724 }
5725 \f
5726 /* ALIGNMENT is a Uint giving the alignment specified for GNAT_ENTITY,
5727 a type or object whose present alignment is ALIGN. If this alignment is
5728 valid, return it. Otherwise, give an error and return ALIGN. */
5730 static unsigned int
5732 Uint alignment;
5733 Entity_Id gnat_entity;
5735 {
5739 #ifndef MAX_OFILE_ALIGNMENT
5740 #define MAX_OFILE_ALIGNMENT BIGGEST_ALIGNMENT
5741 #endif
5746 /* Within GCC, an alignment is an integer, so we must make sure a
5747 value is specified that fits in that range. Also, alignments of
5748 more than MAX_OFILE_ALIGNMENT can't be supported. */
5762 else
5766 }
5767 \f
5768 /* Verify that OBJECT, a type or decl, is something we can implement
5769 atomically. If not, give an error for GNAT_ENTITY. COMP_P is nonzero
5770 if we require atomic components. */
5772 static void
5774 tree object;
5775 Entity_Id gnat_entity;
5777 {
5779 Node_Id gnat_node;
5782 tree size;
5784 /* There are three case of what OBJECT can be. It can be a type, in which
5785 case we take the size, alignment and mode from the type. It can be a
5786 declaration that was indirect, in which case the relevant values are
5787 that of the type being pointed to, or it can be a normal declaration,
5788 in which case the values are of the decl. The code below assumes that
5789 OBJECT is either a type or a decl. */
5791 {
5795 }
5797 {
5801 }
5802 else
5803 {
5807 }
5809 /* Consider all floating-point types atomic and any types that that are
5810 represented by integers no wider than a machine word. */
5817 /* For the moment, also allow anything that has an alignment equal
5818 to its size and which is smaller than a word. */
5826 {
5834 }
5839 else
5842 }
5843 \f
5844 /* Given a type T, a FIELD_DECL F, and a replacement value R,
5845 return a new type with all size expressions that contain F
5846 updated by replacing F with R. This is identical to GCC's
5847 substitute_in_type except that it knows about TYPE_INDEX_TYPE.
5848 If F is NULL_TREE, always make a new RECORD_TYPE, even if nothing has
5849 changed. */
5851 tree
5854 {
5856 tree tem;
5859 {
5868 {
5880 }
5891 {
5905 }
5921 /* Don't know how to do these yet. */
5925 {
5939 }
5944 {
5945 tree field;
5946 int changed_field
5953 /* Start out with no fields, make new fields, and chain them
5954 in. If we haven't actually changed the type of any field,
5955 discard everything we've done and return the old type. */
5962 {
5973 /* If this is an internal field and the type of this field is
5974 a UNION_TYPE or RECORD_TYPE with no elements, ignore it. If
5975 the type just has one element, treat that as the field.
5976 But don't do this if we are processing a QUAL_UNION_TYPE. */
5981 {
5986 {
5987 tree next_new_field
5990 /* Make sure omitting the union doesn't change
5991 the layout. */
5994 }
5995 }
6002 /* If the size of the old field was set at a constant,
6003 propagate the size in case the type's size was variable.
6004 (This occurs in the case of a variant or discriminated
6005 record with a default size used as a field of another
6006 record.) */
6015 {
6021 /* Do the substitution inside the qualifier and if we find
6022 that this field will not be present, omit it. */
6027 }
6031 else
6036 /* If this is a qualified type and this field will always be
6037 present, we are done. */
6041 }
6043 /* If this used to be a qualified union type, but we now know what
6044 field will be present, make this a normal union. */
6057 /* If the size was originally a constant use it. */
6060 {
6064 }
6067 }
6071 }
6072 }
6073 \f
6074 /* Return the "RM size" of GNU_TYPE. This is the actual number of bits
6075 needed to represent the object. */
6077 tree
6079 tree gnu_type;
6080 {
6081 /* For integer types, this is the precision. For record types, we store
6082 the size explicitly. For other types, this is just the size. */
6088 /* Return the rm_size of the actual data plus the size of the template. */
6089 return
6099 else
6101 }
6102 \f
6103 /* Return an identifier representing the external name to be used for
6104 GNAT_ENTITY. If SUFFIX is specified, the name is followed by "___"
6105 and the specified suffix. */
6107 tree
6109 Entity_Id gnat_entity;
6111 {
6119 }
6121 /* Return the name to be used for GNAT_ENTITY. If a type, create a
6122 fully-qualified name, possibly with type information encoding.
6123 Otherwise, return the name. */
6125 tree
6127 Entity_Id gnat_entity;
6128 {
6131 }
6133 /* Given GNU_ID, an IDENTIFIER_NODE containing a name and SUFFIX, a
6134 string, return a new IDENTIFIER_NODE that is the concatenation of
6135 the name in GNU_ID and SUFFIX. */
6137 tree
6139 tree gnu_id;
6141 {
6150 }