| blob | adf648111b3a9673850320e25c0e5206fd8671ab |
1 /****************************************************************************
2 * *
3 * GNAT COMPILER COMPONENTS *
4 * *
5 * D E C L *
6 * *
7 * C Implementation File *
8 * *
9 * *
10 * Copyright (C) 1992-2002, Free Software Foundation, Inc. *
11 * *
12 * GNAT is free software; you can redistribute it and/or modify it under *
13 * terms of the GNU General Public License as published by the Free Soft- *
14 * ware Foundation; either version 2, or (at your option) any later ver- *
15 * sion. GNAT is distributed in the hope that it will be useful, but WITH- *
16 * OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY *
17 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License *
18 * for more details. You should have received a copy of the GNU General *
19 * Public License distributed with GNAT; see file COPYING. If not, write *
20 * to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, *
21 * MA 02111-1307, USA. *
22 * *
23 * GNAT was originally developed by the GNAT team at New York University. *
24 * Extensive contributions were provided by Ada Core Technologies Inc. *
25 * *
26 ****************************************************************************/
55 /* Setting this to 1 suppresses hashing of types. */
58 /* Provide default values for the macros controlling stack checking.
59 This is copied from GCC's expr.h. */
61 #ifndef STACK_CHECK_BUILTIN
62 #define STACK_CHECK_BUILTIN 0
63 #endif
64 #ifndef STACK_CHECK_PROBE_INTERVAL
65 #define STACK_CHECK_PROBE_INTERVAL 4096
66 #endif
67 #ifndef STACK_CHECK_MAX_FRAME_SIZE
68 #define STACK_CHECK_MAX_FRAME_SIZE \
69 (STACK_CHECK_PROBE_INTERVAL - UNITS_PER_WORD)
70 #endif
71 #ifndef STACK_CHECK_MAX_VAR_SIZE
72 #define STACK_CHECK_MAX_VAR_SIZE (STACK_CHECK_MAX_FRAME_SIZE / 100)
73 #endif
75 /* These two variables are used to defer recursively expanding incomplete
76 types while we are processing a record or subprogram type. */
79 static struct incomplete
80 {
82 tree old_type;
83 Entity_Id full_type;
113 \f
114 /* Given GNAT_ENTITY, an entity in the incoming GNAT tree, return a
115 GCC type corresponding to that entity. GNAT_ENTITY is assumed to
116 refer to an Ada type. */
118 tree
120 Entity_Id gnat_entity;
121 {
122 tree gnu_decl;
124 /* Convert the ada entity type into a GCC TYPE_DECL node. */
130 }
131 \f
132 /* Given GNAT_ENTITY, a GNAT defining identifier node, which denotes some Ada
133 entity, this routine returns the equivalent GCC tree for that entity
134 (an ..._DECL node) and associates the ..._DECL node with the input GNAT
135 defining identifier.
137 If GNAT_ENTITY is a variable or a constant declaration, GNU_EXPR gives its
138 initial value (in GCC tree form). This is optional for variables.
139 For renamed entities, GNU_EXPR gives the object being renamed.
141 DEFINITION is nonzero if this call is intended for a definition. This is
142 used for separate compilation where it necessary to know whether an
143 external declaration or a definition should be created if the GCC equivalent
144 was not created previously. The value of 1 is normally used for a non-zero
145 DEFINITION, but a value of 2 is used in special circumstances, defined in
146 the code. */
148 tree
150 Entity_Id gnat_entity;
151 tree gnu_expr;
153 {
154 tree gnu_entity_id;
156 /* Contains the gnu XXXX_DECL tree node which is equivalent to the input
157 GNAT tree. This node will be associated with the GNAT node by calling
158 the save_gnu_tree routine at the end of the `switch' statement. */
160 /* Nonzero if we have already saved gnu_decl as a gnat association. */
162 /* Nonzero if we incremented defer_incomplete_level. */
164 /* Nonzero if we incremented force_global. */
166 /* Nonzero if we should check to see if elaborated during processing. */
168 /* Nonzero if we made GNU_DECL and its type here. */
174 Entity_Id gnat_temp;
175 unsigned int esize
180 ? LONG_DOUBLE_TYPE_SIZE
185 int imported_p
190 /* Since a use of an Itype is a definition, process it as such if it
191 is not in a with'ed unit. */
196 {
197 /* Ensure that we are in a subprogram mentioned in the Scope
198 chain of this entity, our current scope is global,
199 or that we encountered a task or entry (where we can't currently
200 accurately check scoping). */
203 {
206 }
210 {
215 gnat_temp
227 && (current_function_decl
229 {
232 }
233 }
235 /* gigi abort 122 means that the entity "gnat_entity" has an incorrect
236 scope, i.e. that its scope does not correspond to the subprogram
237 in which it is declared */
239 }
241 /* If this is entity 0, something went badly wrong. */
245 /* If we've already processed this entity, return what we got last time.
246 If we are defining the node, we should not have already processed it.
247 In that case, we will abort below when we try to save a new GCC tree for
248 this object. We also need to handle the case of getting a dummy type
249 when a Full_View exists. */
252 && (! definition
254 {
261 {
267 }
270 }
272 /* If this is a numeric or enumeral type, or an access type, a nonzero
273 Esize must be specified unless it was specified by the programmer. */
282 /* Likewise, RM_Size must be specified for all discrete and fixed-point
283 types. */
288 /* Get the name of the entity and set up the line number and filename of
289 the original definition for use in any decl we make. */
294 /* If we get here, it means we have not yet done anything with this
295 entity. If we are not defining it here, it must be external,
296 otherwise we should have defined it already. */
298 && ! type_annotate_only
302 #if 1
304 #endif
305 )
308 /* For cases when we are not defining (i.e., we are referencing from
309 another compilation unit) Public entities, show we are at global level
310 for the purpose of computing sizes. Don't do this for components or
311 discriminants since the relevant test is whether or not the record is
312 being defined. */
318 /* Handle any attributes. */
323 {
325 /* If this is a use of a deferred constant, get its full
326 declaration. */
328 {
333 }
335 /* If we have an external constant that we are not defining,
336 get the expression that is was defined to represent. We
337 may throw that expression away later if it is not a
338 constant. */
344 /* Ignore deferred constant definitions; they are processed fully in the
345 front-end. For deferred constant references, get the full
346 definition. On the other hand, constants that are renamings are
347 handled like variable renamings. If No_Initialization is set, this is
348 not a deferred constant but a constant whose value is built
349 manually. */
354 {
358 }
361 {
366 }
371 /* If this is not a VMS exception, treat it as a normal object.
372 Otherwise, make an object at the specific address of character
373 type, point to it, and convert it to integer, and mask off
374 the lower 3 bits. */
378 /* Allocate the global object that we use to get the value of the
379 exception. */
387 /* Now return the expression giving the desired value. */
388 gnu_decl
392 gnu_decl)),
402 {
403 /* The GNAT record where the component was defined. */
406 /* If the variable is an inherited record component (in the case of
407 extended record types), just return the inherited entity, which
408 must be a FIELD_DECL. Likewise for discriminants.
409 For discriminants of untagged records which have explicit
410 girder discriminants, return the entity for the corresponding
411 girder discriminant. Also use Original_Record_Component
412 if the record has a private extension. */
419 {
420 gnu_decl
425 }
427 /* If the enclosing record has explicit girder discriminants,
428 then it is an untagged record. If the Corresponding_Discriminant
429 is not empty then this must be a renamed discriminant and its
430 Original_Record_Component must point to the corresponding explicit
431 girder discriminant (i.e., we should have taken the previous
432 branch). */
436 {
437 /* A tagged record has no explicit girder discriminants. */
443 gnu_decl
448 }
450 /* If the enclosing record has explicit girder discriminants,
451 then it is an untagged record. If the Corresponding_Discriminant
452 is not empty then this must be a renamed discriminant and its
453 Original_Record_Component must point to the corresponding explicit
454 girder discriminant (i.e., we should have taken the first
455 branch). */
462 /* Otherwise, if we are not defining this and we have no GCC type
463 for the containing record, make one for it. Then we should
464 have made our own equivalent. */
466 {
467 /* ??? If this is in a record whose scope is a protected
468 type and we have an Original_Record_Component, use it.
469 This is a workaround for major problems in protected type
470 handling. */
473 {
474 gnu_decl
480 }
486 }
488 /* Here we have no GCC type and this is a reference rather than a
489 definition. This should never happen. Most likely the cause is a
490 reference before declaration in the gnat tree for gnat_entity. */
491 else
493 }
499 /* Simple variables, loop variables, OUT parameters, and exceptions. */
500 object:
501 {
503 int const_flag
516 {
520 else
522 }
524 /* Get the type after elaborating the renamed object. */
527 /* If this is a loop variable, its type should be the base type.
528 This is because the code for processing a loop determines whether
529 a normal loop end test can be done by comparing the bounds of the
530 loop against those of the base type, which is presumed to be the
531 size used for computation. But this is not correct when the size
532 of the subtype is smaller than the type. */
536 /* Reject non-renamed objects whose types are unconstrained arrays or
537 any object whose type is a dummy type or VOID_TYPE. */
543 {
546 else
548 }
550 /* If we are defining the object, see if it has a Size value and
551 validate it if so. Then get the new type, if any. */
558 {
559 gnu_type
565 }
567 /* If this object has self-referential size, it must be a record with
568 a default value. We are supposed to allocate an object of the
569 maximum size in this case unless it is a constant with an
570 initializing expression, in which case we can get the size from
571 that. Note that the resulting size may still be a variable, so
572 this may end up with an indirect allocation. */
577 {
579 {
583 {
589 }
590 }
592 /* We may have no GNU_EXPR because No_Initialization is
593 set even though there's an Expression. */
598 gnu_size
600 (Etype
602 else
604 }
606 /* If the size is zero bytes, make it one byte since some linkers
607 have trouble with zero-sized objects. But if this will have a
608 template, that will make it nonzero. */
616 /* If an alignment is specified, use it if valid. Note that
617 exceptions are objects but don't have alignments. */
619 {
623 align
626 }
628 /* If this is an atomic object with no specified size and alignment,
629 but where the size of the type is a constant, set the alignment to
630 the lowest power of two greater than the size, or to the
631 biggest meaningful alignment, whichever is smaller. */
635 {
638 BIGGEST_ALIGNMENT))
640 else
645 }
647 #ifdef MINIMUM_ATOMIC_ALIGNMENT
648 /* If the size is a constant and no alignment is specified, force
649 the alignment to be the minimum valid atomic alignment. The
650 restriction on constant size avoids problems with variable-size
651 temporaries; if the size is variable, there's no issue with
652 atomic access. Also don't do this for a constant, since it isn't
653 necessary and can interfere with constant replacement. Finally,
654 do not do it for Out parameters since that creates an
655 size inconsistency with In parameters. */
664 #endif
666 /* If the object is set to have atomic components, find the component
667 type and validate it.
669 ??? Note that we ignore Has_Volatile_Components on objects; it's
670 not at all clear what to do in that case. */
673 {
674 tree gnu_inner
683 }
685 /* Now check if the type of the object allows atomic access. Note
686 that we must test the type, even if this object has size and
687 alignment to allow such access, because we will be going
688 inside the padded record to assign to the object. We could fix
689 this by always copying via an intermediate value, but it's not
690 clear it's worth the effort. */
694 /* Make a new type with the desired size and alignment, if needed. */
698 /* Make a volatile version of this object's type if we are to
699 make the object volatile. Note that 13.3(19) says that we
700 should treat other types of objects as volatile as well. */
710 /* If this is an aliased object with an unconstrained nominal subtype,
711 make a type that includes the template. */
715 {
716 tree gnu_fat
718 tree gnu_temp_type
721 gnu_type
725 }
727 /* Convert the expression to the type of the object except in the
728 case where the object's type is unconstrained or the object's type
729 is a padded record whose field is of self-referential size. In
730 the former case, converting will generate unnecessary evaluations
731 of the CONSTRUCTOR to compute the size and in the latter case, we
732 want to only copy the actual data. */
739 && (contains_placeholder_p
743 /* See if this is a renaming. If this is a constant renaming,
744 treat it as a normal variable whose initial value is what
745 is being renamed. We cannot do this if the type is
746 unconstrained or class-wide.
748 Otherwise, if what we are renaming is a reference, we can simply
749 return a stabilized version of that reference, after forcing
750 any SAVE_EXPRs to be evaluated. But, if this is at global level,
751 we can only do this if we know no SAVE_EXPRs will be made.
752 Otherwise, make this into a constant pointer to the object we are
753 to rename. */
756 {
757 /* If the renamed object had padding, strip off the reference
758 to the inner object and reset our type. */
762 && (TYPE_IS_PADDING_P
764 {
767 }
774 ;
776 /* If this is a declaration or reference, we can just use that
777 declaration or reference as this entity. */
784 {
792 gnu_decl));
794 }
795 else
796 {
803 }
804 }
806 /* If this is an aliased object whose nominal subtype is unconstrained,
807 the object is a record that contains both the template and
808 the object. If there is an initializer, it will have already
809 been converted to the right type, but we need to create the
810 template if there is no initializer. */
814 gnu_expr
815 = build_constructor
817 tree_cons
819 build_template
822 NULL_TREE),
823 NULL_TREE));
825 /* If this is a pointer and it does not have an initializing
826 expression, initialize it to NULL. */
832 /* If we are defining the object and it has an Address clause we must
833 get the address expression from the saved GCC tree for the
834 object if the object has a Freeze_Node. Otherwise, we elaborate
835 the address expression here since the front-end has guaranteed
836 in that case that the elaboration has no effects. Note that
837 only the latter mechanism is currently in use. */
839 {
840 tree gnu_address
846 /* Ignore the size. It's either meaningless or was handled
847 above. */
854 /* If we don't have an initializing expression for the underlying
855 variable, the initializing expression for the pointer is the
856 specified address. Otherwise, we have to make a COMPOUND_EXPR
857 to assign both the address and the initial value. */
860 else
861 gnu_expr
863 build_binary_op
866 gnu_address),
867 gnu_expr),
868 gnu_address);
869 }
871 /* If it has an address clause and we are not defining it, mark it
872 as an indirect object. Likewise for Stdcall objects that are
873 imported. */
877 {
881 }
883 /* If we are at top level and this object is of variable size,
884 make the actual type a hidden pointer to the real type and
885 make the initializer be a memory allocation and initialization.
886 Likewise for objects we aren't defining (presumed to be
887 external references from other packages), but there we do
888 not set up an initialization.
890 If the object's size overflows, make an allocator too, so that
891 Storage_Error gets raised. Note that we will never free
892 such memory, so we presume it never will get allocated. */
901 {
907 /* Get the data part of GNU_EXPR in case this was a
908 aliased object whose nominal subtype is unconstrained.
909 In that case the pointer above will be a thin pointer and
910 build_allocator will automatically make the template and
911 constructor already made above. */
914 {
919 {
920 gnu_alloc_type
922 gnu_expr
923 = build_component_ref
926 }
932 gnat_entity);
936 }
937 else
938 {
941 }
942 }
944 /* If this object would go into the stack and has an alignment
945 larger than the default largest alignment, make a variable
946 to hold the "aligning type" with a modified initial value,
947 if any, then point to it and make that the value of this
948 variable, which is now indirect. */
952 {
953 tree gnu_new_type
956 tree gnu_new_var;
959 gnu_expr
964 gnu_new_var
970 gnu_expr
971 = build_unary_op
979 }
981 /* Convert the expression to the type of the object except in the
982 case where the object's type is unconstrained or the object's type
983 is a padded record whose field is of self-referential size. In
984 the former case, converting will generate unnecessary evaluations
985 of the CONSTRUCTOR to compute the size and in the latter case, we
986 want to only copy the actual data. */
993 && (contains_placeholder_p
997 /* This name is external or there was a name specified, use it.
998 Don't use the Interface_Name if there is an address clause.
999 (see CD30005). */
1010 /* If this is constant initialized to a static constant and the
1011 object has an aggregrate type, force it to be statically
1012 allocated. */
1036 STACK_CHECK_MAX_VAR_SIZE))))
1039 /* If this is a public constant or we're not optimizing and we're not
1040 making a VAR_DECL for it, make one just for export or debugger
1041 use. Likewise if the address is taken or if the object or type is
1042 aliased. */
1054 /* If this is declared in a block that contains an block with an
1055 exception handler, we must force this variable in memory to
1056 suppress an invalid optimization. */
1059 {
1062 }
1064 /* Back-annotate the Alignment of the object if not already in the
1065 tree. Likewise for Esize if the object is of a constant size.
1066 But if the "object" is actually a pointer to an object, the
1067 alignment and size are the same as teh type, so don't back-annotate
1068 the values for the pointer. */
1075 {
1080 gnu_back_size
1085 }
1086 }
1090 /* Return a TYPE_DECL for "void" that we previously made. */
1095 /* A special case, for the types Character and Wide_Character in
1096 Standard, we do not list all the literals. So if the literals
1097 are not specified, make this an unsigned type. */
1099 {
1102 }
1104 /* Normal case of non-character type, or non-Standard character type */
1105 {
1106 /* Here we have a list of enumeral constants in First_Literal.
1107 We make a CONST_DECL for each and build into GNU_LITERAL_LIST
1108 the list to be places into TYPE_FIELDS. Each node in the list
1109 is a TREE_LIST node whose TREE_VALUE is the literal name
1110 and whose TREE_PURPOSE is the value of the literal.
1112 Esize contains the number of bits needed to represent the enumeral
1113 type, Type_Low_Bound also points to the first literal and
1114 Type_High_Bound points to the last literal. */
1116 Entity_Id gnat_literal;
1121 else
1129 {
1131 gnu_type);
1132 tree gnu_literal
1139 }
1143 /* Note that the bounds are updated at the end of this function
1144 because to avoid an infinite recursion when we get the bounds of
1145 this type, since those bounds are objects of this type. */
1146 }
1152 /* For integer types, just make a signed type the appropriate number
1153 of bits. */
1158 /* For modular types, make the unsigned type of the proper number of
1159 bits and then set up the modulus, if required. */
1160 {
1162 tree gnu_modulus;
1168 /* Find the smallest mode at least ESIZE bits wide and make a class
1169 using that mode. */
1174 ;
1180 /* Get the modulus in this type. If it overflows, assume it is because
1181 it is equal to 2**Esize. Note that there is no overflow checking
1182 done on unsigned type, so we detect the overflow by looking for
1183 a modulus of zero, which is otherwise invalid. */
1187 {
1192 }
1194 /* If we have to set TYPE_PRECISION different from its natural value,
1195 make a subtype to do do. Likewise if there is a modulus and
1196 it is not one greater than TYPE_MAX_VALUE. */
1200 {
1217 }
1218 }
1227 /* For integral subtypes, we make a new INTEGER_TYPE. Note
1228 that we do not want to call build_range_type since we would
1229 like each subtype node to be distinct. This will be important
1230 when memory aliasing is implemented.
1232 The TREE_TYPE field of the INTEGER_TYPE we make points to the
1233 parent type; this fact is used by the arithmetic conversion
1234 functions.
1236 We elaborate the Ancestor_Subtype if it is not in the current
1237 unit and one of our bounds is non-static. We do this to ensure
1238 consistent naming in the case where several subtypes share the same
1239 bounds by always elaborating the first such subtype first, thus
1240 using its name. */
1252 {
1256 }
1264 gnat_entity,
1271 gnat_entity,
1275 /* One of the above calls might have caused us to be elaborated,
1276 so don't blow up if so. */
1278 {
1281 }
1286 /* This should be an unsigned type if the lower bound is constant
1287 and non-negative or if the base type is unsigned; a signed type
1288 otherwise. */
1299 {
1301 tree gnu_field;
1314 }
1319 /* If this is a VAX floating-point type, use an integer of the proper
1320 size. All the operations will be handled with ASM statements. */
1322 {
1328 }
1330 /* The type of the Low and High bounds can be our type if this is
1331 a type from Standard, so set them at the end of the function. */
1339 {
1342 }
1344 {
1359 ;
1379 /* One of the above calls might have caused us to be elaborated,
1380 so don't blow up if so. */
1382 {
1385 }
1388 }
1391 /* Array and String Types and Subtypes
1393 Unconstrained array types are represented by E_Array_Type and
1394 constrained array types are represented by E_Array_Subtype. There
1395 are no actual objects of an unconstrained array type; all we have
1396 are pointers to that type.
1398 The following fields are defined on array types and subtypes:
1400 Component_Type Component type of the array.
1401 Number_Dimensions Number of dimensions (an int).
1402 First_Index Type of first index. */
1406 {
1412 int firstdim
1414 int nextdim
1420 tree gnu_max_size_unit;
1422 Entity_Id gnat_ind_subtype;
1423 Entity_Id gnat_ind_base_subtype;
1424 tree gnu_template_reference;
1425 tree tem;
1433 /* Make a node for the array. If we are not defining the array
1434 suppress expanding incomplete types and save the node as the type
1435 for GNAT_ENTITY. */
1438 {
1439 defer_incomplete_level++;
1443 debug_info_p);
1446 }
1448 /* Build the fat pointer type. Use a "void *" object instead of
1449 a pointer to the array type since we don't have the array type
1450 yet (it will reference the fat pointer via the bounds). */
1453 ptr_void_type_node,
1456 gnu_ptr_template,
1459 /* Make sure we can put this into a register. */
1463 /* Build a reference to the template from a PLACEHOLDER_EXPR that
1464 is the fat pointer. This will be used to access the individual
1465 fields once we build them. */
1469 gnu_template_reference
1473 /* Now create the GCC type for each index and add the fields for
1474 that index to the template. */
1476 gnat_ind_base_subtype
1482 {
1484 tree gnu_ind_subtype
1486 tree gnu_base_subtype
1488 tree gnu_base_min
1490 tree gnu_base_max
1494 /* Make the FIELD_DECLs for the minimum and maximum of this
1495 type and then make extractions of that field from the
1496 template. */
1500 gnu_ind_subtype,
1504 gnu_ind_subtype,
1509 /* We can't use build_component_ref here since the template
1510 type isn't complete yet. */
1517 /* Make a range type with the new ranges, but using
1518 the Ada subtype. Then we convert to sizetype. */
1524 /* Update the maximum size of the array, in elements. */
1525 gnu_max_size
1529 gnu_base_min)));
1533 }
1536 gnu_template_fields
1539 /* Install all the fields into the template. */
1543 /* Now make the array of arrays and update the pointer to the array
1544 in the fat pointer. Note that it is the first field. */
1548 /* Get and validate any specified Component_Size, but if Packed,
1549 ignore it since the front end will have taken care of it. Also,
1550 allow sizes not a multiple of Storage_Unit if packed. */
1551 gnu_comp_size
1553 gnat_entity,
1561 /* If the component type is a RECORD_TYPE that has a self-referential
1562 size, use the maxium size. */
1569 {
1573 }
1579 /* If Component_Size is not already specified, annotate it with the
1580 size of the component. */
1590 gnu_max_size),
1594 {
1599 }
1601 /* If an alignment is specified, use it if valid. But ignore it for
1602 types that represent the unpacked base type for packed arrays. */
1605 {
1612 }
1618 /* The result type is an UNCONSTRAINED_ARRAY_TYPE that indicates the
1619 corresponding fat pointer. */
1626 /* If the maximum size doesn't overflow, use it. */
1639 debug_info_p);
1642 /* Create a record type for the object and its template and
1643 set the template at a negative offset. */
1655 /* Give the thin pointer type a name. */
1659 }
1665 /* This is the actual data type for array variables. Multidimensional
1666 arrays are implemented in the gnu tree as arrays of arrays. Note
1667 that for the moment arrays which have sparse enumeration subtypes as
1668 index components create sparse arrays, which is obviously space
1669 inefficient but so much easier to code for now.
1671 Also note that the subtype never refers to the unconstrained
1672 array type, which is somewhat at variance with Ada semantics.
1674 First check to see if this is simply a renaming of the array
1675 type. If so, the result is the array type. */
1680 else
1681 {
1684 int first_dim
1687 int next_dim
1689 Entity_Id gnat_ind_subtype;
1690 Entity_Id gnat_ind_base_subtype;
1695 tree gnu_max_size_unit;
1699 /* First create the gnu types for each index. Create types for
1700 debugging information to point to the index types if the
1701 are not integer types, have variable bounds, or are
1702 wider than sizetype. */
1705 gnat_ind_base_subtype
1711 {
1712 tree gnu_index_subtype
1714 tree gnu_min
1716 tree gnu_max
1718 tree gnu_base_subtype
1720 tree gnu_base_min
1722 tree gnu_base_max
1725 tree gnu_base_base_min
1727 tree gnu_base_base_max
1729 tree gnu_high;
1730 tree gnu_this_max;
1732 /* If the minimum and maximum values both overflow in
1733 SIZETYPE, but the difference in the original type
1734 does not overflow in SIZETYPE, ignore the overflow
1735 indications. */
1741 && (! TREE_OVERFLOW
1749 /* Similarly, if the range is null, use bounds of 1..0 for
1750 the sizetype bounds. */
1760 /* Now compute the size of this bound. We need to provide
1761 GCC with an upper bound to use but have to deal with the
1762 "superflat" case. There are three ways to do this. If we
1763 can prove that the array can never be superflat, we can
1764 just use the high bound of the index subtype. If we can
1765 prove that the low bound minus one can't overflow, we
1766 can do this as MAX (hb, lb - 1). Otherwise, we have to use
1767 the expression hb >= lb ? hb : lb - 1. */
1770 /* See if the base array type is already flat. If it is, we
1771 are probably compiling an ACVC test, but it will cause the
1772 code below to malfunction if we don't handle it specially. */
1780 /* If gnu_high is now an integer which overflowed, the array
1781 cannot be superflat. */
1788 else
1789 gnu_high
1790 = build_cond_expr
1798 /* Also compute the maximum size of the array. Here we
1799 see if any constraint on the index type of the base type
1800 can be used in the case of self-referential bound on
1801 the index type of the subtype. We look for a non-"infinite"
1802 and non-self-referential bound from any type involved and
1803 handle each bound separately. */
1830 gnu_this_max
1834 gnu_base_min)),
1835 size_zero_node);
1841 gnu_max_size
1855 }
1857 /* Then flatten: create the array of arrays. */
1861 /* One of the above calls might have caused us to be elaborated,
1862 so don't blow up if so. */
1864 {
1867 }
1869 /* Get and validate any specified Component_Size, but if Packed,
1870 ignore it since the front end will have taken care of it. Also,
1871 allow sizes not a multiple of Storage_Unit if packed. */
1872 gnu_comp_size
1874 gnat_entity,
1879 /* If the component type is a RECORD_TYPE that has a self-referential
1880 size, use the maxium size. */
1887 {
1892 }
1905 /* We don't want any array types shared for two reasons: first,
1906 we want to keep differently-named types distinct; second,
1907 setting TYPE_MULTI_ARRAY_TYPE of one type can clobber
1908 another. */
1911 {
1916 }
1918 /* If we are at file level and this is a multi-dimensional array, we
1919 need to make a variable corresponding to the stride of the
1920 inner dimensions. */
1922 {
1924 tree gnu_arr_type;
1930 {
1936 = elaborate_expression_1
1939 }
1940 }
1942 /* If we need to write out a record type giving the names of
1943 the bounds, do it now. */
1945 {
1948 tree gnu_field;
1954 {
1955 tree gnu_type_name
1962 integer_type_node,
1963 gnu_bound_rec_type,
1967 }
1970 }
1976 /* If our size depends on a placeholder and the maximum size doesn't
1977 overflow, use it. */
1985 {
1991 }
1993 /* Set our alias set to that of our base type. This gives all
1994 array subtypes the same alias set. */
1997 }
1999 /* If this is a packed type, make this type the same as the packed
2000 array type, but do some adjusting in the type first. */
2003 {
2004 Entity_Id gnat_index;
2005 tree gnu_inner_type;
2007 /* First finish the type we had been making so that we output
2008 debugging information for it */
2011 | (TYPE_QUAL_VOLATILE
2016 debug_info_p);
2020 /* Save it as our equivalent in case the call below elaborates
2021 this type again. */
2035 /* We need to point the type we just made to our index type so
2036 the actual bounds can be put into a template. */
2042 {
2044 {
2045 /* The TYPE_ACTUAL_BOUNDS field is also used for the modulus.
2046 If it is, we need to make another type. */
2048 {
2049 tree gnu_subtype;
2066 }
2069 }
2087 }
2088 }
2090 /* Abort if packed array with no packed array type field set. */
2097 /* Create the type for a string literal. */
2098 {
2099 Entity_Id gnat_full_type
2104 tree gnu_string_array_type
2106 tree gnu_string_index_type
2108 tree gnu_lower_bound
2113 tree gnu_upper_bound
2115 gnu_lower_bound,
2117 tree gnu_range_type
2120 tree gnu_index_type
2125 gnu_range_type);
2127 gnu_type
2129 gnu_index_type);
2130 }
2133 /* Record Types and Subtypes
2135 The following fields are defined on record types:
2137 Has_Discriminants True if the record has discriminants
2138 First_Discriminant Points to head of list of discriminants
2139 First_Entity Points to head of list of fields
2140 Is_Tagged_Type True if the record is tagged
2142 Implementation of Ada records and discriminated records:
2144 A record type definition is transformed into the equivalent of a C
2145 struct definition. The fields that are the discriminants which are
2146 found in the Full_Type_Declaration node and the elements of the
2147 Component_List found in the Record_Type_Definition node. The
2148 Component_List can be a recursive structure since each Variant of
2149 the Variant_Part of the Component_List has a Component_List.
2151 Processing of a record type definition comprises starting the list of
2152 field declarations here from the discriminants and the calling the
2153 function components_to_record to add the rest of the fields from the
2154 component list and return the gnu type node. The function
2155 components_to_record will call itself recursively as it traverses
2156 the tree. */
2160 {
2161 gnu_type
2162 = build_complex_type
2163 (get_unpadded_type
2166 (Component_List
2167 (Type_Definition
2172 }
2174 {
2177 Entity_Id gnat_field;
2178 tree gnu_field;
2180 tree gnu_get_parent;
2187 int is_extension
2191 /* See if all fields have a rep clause. Stop when we find one
2192 that doesn't. */
2201 /* If this is a record extension, go a level further to find the
2202 record definition. Also, verify we have a Parent_Subtype. */
2204 {
2211 }
2213 /* Make a node for the record. If we are not defining the record,
2214 suppress expanding incomplete types and save the node as the type
2215 for GNAT_ENTITY. We use the same RECORD_TYPE as was made
2216 for a dummy type and then show it's no longer a dummy. */
2226 {
2227 defer_incomplete_level++;
2232 debug_info_p);
2235 }
2237 /* If both a size and rep clause was specified, put the size in
2238 the record type now so that it can get the proper mode. */
2242 /* Always set the alignment here so that it can be used to
2243 set the mode, if it is making the alignment stricter. If
2244 it is invalid, it will be checked again below. If this is to
2245 be Atomic, choose a default alignment of a word. */
2253 /* If we have a Parent_Subtype, make a field for the parent. If
2254 this record has rep clauses, force the position to zero. */
2256 {
2257 tree gnu_parent;
2259 /* A major complexity here is that the parent subtype will
2260 reference our discriminants. But those must reference
2261 the parent component of this record. So here we will
2262 initialize each of those components to a COMPONENT_REF.
2263 The first operand of that COMPONENT_REF is another
2264 COMPONENT_REF which will be filled in below, once
2265 the parent type can be safely built. */
2270 NULL_TREE));
2277 save_gnu_tree
2281 gnu_get_parent,
2289 gnu_field_list
2299 }
2301 /* Add the fields for the discriminants into the record. */
2307 {
2308 /* If this is a record extension and this discriminant
2309 is the renaming of another discriminant, we've already
2310 handled the discriminant above. */
2315 gnu_field
2318 /* Make an expression using a PLACEHOLDER_EXPR from the
2319 FIELD_DECL node just created and link that with the
2320 corresponding GNAT defining identifier. Then add to the
2321 list of fields. */
2326 gnu_field),
2331 }
2333 /* Put the discriminants into the record (backwards), so we can
2334 know the appropriate discriminant to use for the names of the
2335 variants. */
2338 /* Add the listed fields into the record and finish up. */
2347 /* If this is an extension type, reset the tree for any
2348 inherited discriminants. Also remove the PLACEHOLDER_EXPR
2349 for non-inherited discriminants. */
2355 {
2359 else
2360 {
2364 }
2365 }
2367 /* If it is a tagged record force the type to BLKmode to insure
2368 that these objects will always be placed in memory. Do the
2369 same thing for limited record types. */
2374 /* Fill in locations of fields. */
2377 /* If there are any entities in the chain corresponding to
2378 components that we did not elaborate, ensure we elaborate their
2379 types if they are Itypes. */
2387 }
2391 /* If an equivalent type is present, that is what we should use.
2392 Otherwise, fall through to handle this like a record subtype
2393 since it may have constraints. */
2396 {
2400 }
2402 /* ... fall through ... */
2406 /* If Cloned_Subtype is Present it means this record subtype has
2407 identical layout to that type or subtype and we should use
2408 that GCC type for this one. The front end guarantees that
2409 the component list is shared. */
2411 {
2415 }
2417 /* Otherwise, first ensure the base type is elaborated. Then, if we are
2418 changing the type, make a new type with each field having the
2419 type of the field in the new subtype but having the position
2420 computed by transforming every discriminant reference according
2421 to the constraints. We don't see any difference between
2422 private and nonprivate type here since derivations from types should
2423 have been deferred until the completion of the private type. */
2424 else
2425 {
2427 tree gnu_base_type;
2428 tree gnu_orig_type;
2433 /* Get the base type initially for its alignment and sizes. But
2434 if it is a padded type, we do all the other work with the
2435 unpadded type. */
2444 {
2447 }
2449 /* When the type has discriminants, and these discriminants
2450 affect the shape of what it built, factor them in.
2452 If we are making a subtype of an Unchecked_Union (must be an
2453 Itype), just return the type.
2455 We can't just use Is_Constrained because private subtypes without
2456 discriminants of full types with discriminants with default
2457 expressions are Is_Constrained but aren't constrained! */
2465 {
2466 Entity_Id gnat_field;
2467 Entity_Id gnat_root_type;
2469 tree gnu_pos_list
2472 BIGGEST_ALIGNMENT);
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
2489 BIGGEST_ALIGNMENT);
2492 gnu_subst_list
2495 }
2507 {
2508 tree gnu_old_field
2509 = gnat_to_gnu_entity
2511 tree gnu_offset
2513 gnu_pos_list));
2516 tree gnu_field_type
2520 unsigned int offset_align
2523 tree gnu_field;
2525 /* If there was a component clause, the field types must be
2526 the same for the type and subtype, so copy the data from
2527 the old field to avoid recomputation here. */
2530 {
2533 }
2535 /* If this was a bitfield, get the size from the old field.
2536 Also ensure the type can be placed into a bitfield. */
2538 {
2544 }
2554 /* If the size is now a constant, we can set it as the
2555 size of the field when we make it. Otherwise, we need
2556 to deal with it specially. */
2560 gnu_field
2561 = create_field_decl
2567 {
2576 bitsize_unit_node));
2578 }
2593 }
2597 /* Now set the size, alignment and alias set of the new type to
2598 match that of the old one, doing any substitutions, as
2599 above. */
2634 /* Recompute the mode of this record type now that we know its
2635 actual size. */
2638 /* Fill in locations of fields. */
2640 }
2642 /* If we've made a new type, record it and make an XVS type to show
2643 what this is a subtype of. Some debuggers require the XVS
2644 type to be output first, so do it in that order. */
2646 {
2648 {
2659 integer_type_node,
2660 gnu_subtype_marker,
2664 }
2670 gnu_type));
2674 }
2676 /* Otherwise, go down all the components in the new type and
2677 make them equivalent to those in the base type. */
2678 else
2685 get_gnu_tree
2687 }
2691 /* If we are not defining this entity, and we have incomplete
2692 entities being processed above us, make a dummy type and
2693 fill it in later. */
2695 {
2699 gnu_type
2700 = build_pointer_type
2704 debug_info_p);
2713 }
2715 /* ... fall through ... */
2722 {
2724 Entity_Id gnat_desig_full
2726 Incomplete_Or_Private_Kind))
2728 /* We want to know if we'll be seeing the freeze node for any
2729 incomplete type we may be pointing to. */
2730 int in_main_unit
2742 {
2744 {
2748 }
2750 Incomplete_Or_Private_Kind))
2752 }
2757 /* If either the designated type or its full view is an
2758 unconstrained array subtype, replace it with the type it's a
2759 subtype of. This avoids problems with multiple copies of
2760 unconstrained array types. */
2769 /* If the designated type is a subtype of an incomplete record type,
2770 use the parent type to avoid order of elaboration issues. This
2771 can lose some code efficiency, but there is no alternative. */
2777 /* If we are pointing to an incomplete type whose completion is an
2778 unconstrained array, make a fat pointer type instead of a pointer
2779 to VOID. The two types in our fields will be pointers to VOID and
2780 will be replaced in update_pointer_to. Similiarly, if the type
2781 itself is a dummy type or an unconstrained array. Also make
2782 a dummy TYPE_OBJECT_RECORD_TYPE in case we have any thin
2783 pointers to it. */
2804 {
2805 tree gnu_old
2809 tree fields;
2811 /* Show the dummy we get will be a fat pointer. */
2814 /* If the call above got something that has a pointer, that
2815 pointer is our type. This could have happened either
2816 because the type was elaborated or because somebody
2817 else executed the code below. */
2820 {
2826 fields
2828 create_field_decl
2833 ptr_void_type_node,
2836 /* Make sure we can place this into a register. */
2847 }
2848 }
2850 /* If we already know what the full type is, use it. */
2855 /* Get the type of the thing we are to point to and build a pointer
2856 to it. If it is a reference to an incomplete or private type with a
2857 full view that is a record, make a dummy type node and get the
2858 actual type later when we have verified it is safe. */
2864 {
2867 }
2869 /* Likewise if we are pointing to a record or array and we are to defer
2870 elaborating incomplete types. We do this since this access type
2871 may be the full view of some private type. Note that the
2872 unconstrained array case is handled above. */
2880 {
2883 }
2885 {
2888 }
2889 else
2892 /* It is possible that the above call to gnat_to_gnu_type resolved our
2893 type. If so, just return it. */
2895 {
2898 }
2900 /* If we have a GCC type for the designated type, possibly
2901 modify it if we are pointing only to constant objects and then
2902 make a pointer to it. Don't do this for unconstrained arrays. */
2904 {
2907 gnu_desig_type
2913 }
2915 /* If we are not defining this object and we made a dummy pointer,
2916 save our current definition, evaluate the actual type, and replace
2917 the tentative type we made with the actual one. If we are to defer
2918 actually looking up the actual type, make an entry in the
2919 deferred list. */
2922 {
2923 tree gnu_old_type
2929 gnu_type
2930 = build_pointer_type
2931 (TYPE_OBJECT_RECORD_TYPE
2936 debug_info_p);
2943 else
2944 {
2952 }
2953 }
2954 }
2960 else
2961 /* The runtime representation is the equivalent type. */
2975 /* We treat this as identical to its base type; any constraint is
2976 meaningful only to the front end.
2978 The designated type must be elaborated as well, if it does
2979 not have its own freeze node. Designated (sub)types created
2980 for constrained components of records with discriminants are
2981 not frozen by the front end and thus not elaborated by gigi,
2982 because their use may appear before the base type is frozen,
2983 and because it is not clear that they are needed anywhere in
2984 Gigi. With the current model, there is no correct place where
2985 they could be elaborated. */
2992 {
2993 /* If we are not defining this entity, and we have incomplete
2994 entities being processed above us, make a dummy type and
2995 elaborate it later. */
2997 {
3000 tree gnu_ptr_type
3001 = build_pointer_type
3008 }
3009 else
3012 }
3017 /* Subprogram Entities
3019 The following access functions are defined for subprograms (functions
3020 or procedures):
3022 First_Formal The first formal parameter.
3023 Is_Imported Indicates that the subprogram has appeared in
3024 an INTERFACE or IMPORT pragma. For now we
3025 assume that the external language is C.
3026 Is_Inlined True if the subprogram is to be inlined.
3028 In addition for function subprograms we have:
3030 Etype Return type of the function.
3032 Each parameter is first checked by calling must_pass_by_ref on its
3033 type to determine if it is passed by reference. For parameters which
3034 are copied in, if they are Ada IN OUT or OUT parameters, their return
3035 value becomes part of a record which becomes the return type of the
3036 function (C function - note that this applies only to Ada procedures
3037 so there is no Ada return type). Additional code to store back the
3038 parameters will be generated on the caller side. This transformation
3039 is done here, not in the front-end.
3041 The intended result of the transformation can be seen from the
3042 equivalent source rewritings that follow:
3044 struct temp {int a,b};
3045 procedure P (A,B: IN OUT ...) is temp P (int A,B) {
3046 .. ..
3047 end P; return {A,B};
3048 }
3049 procedure call
3051 {
3052 temp t;
3053 P(X,Y); t = P(X,Y);
3054 X = t.a , Y = t.b;
3055 }
3057 For subprogram types we need to perform mainly the same conversions to
3058 GCC form that are needed for procedures and function declarations. The
3059 only difference is that at the end, we make a type declaration instead
3060 of a function declaration. */
3065 {
3066 /* The first GCC parameter declaration (a PARM_DECL node). The
3067 PARM_DECL nodes are chained through the TREE_CHAIN field, so this
3068 actually is the head of this parameter list. */
3070 /* The type returned by a function. If the subprogram is a procedure
3071 this type should be void_type_node. */
3073 /* List of fields in return type of procedure with copy in copy out
3074 parameters. */
3076 /* Non-null for subprograms containing parameters passed by copy in
3077 copy out (Ada IN OUT or OUT parameters not passed by reference),
3078 in which case it is the list of nodes used to specify the values of
3079 the in out/out parameters that are returned as a record upon
3080 procedure return. The TREE_PURPOSE of an element of this list is
3081 a field of the record and the TREE_VALUE is the PARM_DECL
3082 corresponding to that field. This list will be saved in the
3083 TYPE_CI_CO_LIST field of the FUNCTION_TYPE node we create. */
3085 Entity_Id gnat_param;
3088 int extern_flag
3099 /* A parameter may refer to this type, so defer completion
3100 of any incomplete types. */
3103 /* If the subprogram has an alias, it is probably inherited, so
3104 we can use the original one. If the original "subprogram"
3105 is actually an enumeration literal, it may be the first use
3106 of its type, so we must elaborate that type now. */
3108 {
3115 /* Elaborate any Itypes in the parameters of this entity. */
3123 }
3128 /* If this function returns by reference, make the actual
3129 return type of this function the pointer and mark the decl. */
3131 {
3135 }
3137 /* If we are supposed to return an unconstrained array,
3138 actually return a fat pointer and make a note of that. Return
3139 a pointer to an unconstrained record of variable size. */
3141 {
3144 }
3146 /* If the type requires a transient scope, the result is allocated
3147 on the secondary stack, so the result type of the function is
3148 just a pointer. */
3150 {
3153 }
3155 /* If the type is a padded type and the underlying type would not
3156 be passed by reference or this function has a foreign convention,
3157 return the underlying type. */
3165 /* Look at all our parameters and get the type of
3166 each. While doing this, build a copy-out structure if
3167 we need one. */
3172 {
3182 /* See if a Mechanism was supplied that forced this
3183 parameter to be passed one way or another. */
3187 ;
3195 {
3201 else
3203 }
3204 else
3207 /* If this is either a foreign function or if the
3208 underlying type won't be passed by refererence, strip off
3209 possible padding type. */
3217 /* If this is an IN parameter it is read-only, so make a variant
3218 of the type that is read-only.
3220 ??? However, if this is an unconstrained array, that type can
3221 be very complex. So skip it for now. Likewise for any other
3222 self-referential type. */
3228 gnu_param_type
3233 /* For foreign conventions, pass arrays as a pointer to the
3234 underlying type. First check for unconstrained array and get
3235 the underlying array. Then get the component type and build
3236 a pointer to it. */
3239 gnu_param_type
3244 gnu_param_type
3245 = build_pointer_type
3248 gnat_entity));
3251 && ! req_by_copy
3253 {
3254 /* Strip off any multi-dimensional entries, then strip
3255 off the last array to get the component type. */
3264 gnu_param_type
3270 }
3272 /* Fat pointers are passed as thin pointers for foreign
3273 conventions. */
3276 gnu_param_type
3280 /* If we must pass or were requested to pass by reference, do so.
3281 If we were requested to pass by copy, do so.
3282 Otherwise, for foreign conventions, pass all in out parameters
3283 or aggregates by reference. For COBOL and Fortran, pass
3284 all integer and FP types that way too. For Convention Ada,
3285 use the standard Ada default. */
3287 || (! req_by_copy
3297 /* For convention Ada, see if we pass by reference
3298 by default. */
3301 {
3304 }
3312 /* If this is an OUT parameter that isn't passed by reference
3313 and isn't a pointer or aggregate, we don't make a PARM_DECL
3314 for it. Instead, it will be a VAR_DECL created when we process
3315 the procedure. For the special parameter of Valued_Procedure,
3316 never pass it in. */
3319 || (! by_descr_p
3323 else
3324 {
3326 gnu_param
3327 = create_param_decl
3329 by_ref_p || by_component_ptr_p
3341 /* If a parameter is a pointer, this function may modify
3342 memory through it and thus shouldn't be considered
3343 a pure function. Also, the memory may be modified
3344 between two calls, so they can't be CSE'ed. The latter
3345 case also handles by-ref parameters. */
3349 }
3352 {
3354 {
3361 }
3369 gnu_return_list);
3370 }
3371 }
3373 /* Do not compute record for out parameters if subprogram is
3374 stubbed since structures are incomplete for the back-end. */
3380 /* If we have a CICO list but it has only one entry, we convert
3381 this function into a function that simply returns that one
3382 object. */
3387 {
3397 }
3399 /* Both lists ware built in reverse. */
3403 gnu_type
3406 returns_by_ref,
3409 /* ??? For now, don't consider nested functions pure. */
3413 gnu_type
3419 /* Top-level or external functions need to have an assembler name.
3420 This is passed to create_subprog_decl through the ext_name argument.
3421 For Pragma Interface subprograms with no Pragma Interface_Name, the
3422 simple name already in entity_name is correct, and this is what is
3423 gotten when ext_name is NULL. If Interface_Name is specified, then
3424 the name is extracted from the N_String_Literal node containing the
3425 string specified in the Pragma. If there is no Pragma Interface,
3426 then the Ada fully qualified name is created. */
3430 {
3433 /* If there wasn't a specified Interface_Name, use this for the
3434 main name of the entity. This will cause GCC to allow
3435 qualification of a nested subprogram with a unique ID. We
3436 need this in case there is an overloaded subprogram somewhere
3437 up the scope chain.
3439 ??? This may be a kludge. */
3442 }
3446 /* If we are defining the subprogram and it has an Address clause
3447 we must get the address expression from the saved GCC tree for the
3448 subprogram if it has a Freeze_Node. Otherwise, we elaborate
3449 the address expression here since the front-end has guaranteed
3450 in that case that the elaboration has no effects. If there is
3451 an Address clause and we are not defining the object, just
3452 make it a constant. */
3454 {
3458 gnu_address
3469 gnu_decl
3474 }
3479 debug_info_p);
3480 else
3481 {
3488 }
3489 }
3500 /* If this type does not have a full view in the unit we are
3501 compiling, then just get the type from its Etype. */
3503 {
3504 /* If this is an incomplete type with no full view, it must
3505 be a Taft Amendement type, so just return a dummy type. */
3512 else
3513 {
3517 }
3520 }
3522 /* Otherwise, if we are not defining the type now, get the
3523 type from the full view. But always get the type from the full
3524 view for define on use types, since otherwise we won't see them! */
3531 {
3536 }
3538 /* For incomplete types, make a dummy type entry which will be
3539 replaced later. */
3542 /* Save this type as the full declaration's type so we can do any needed
3543 updates when we see it. */
3547 debug_info_p);
3551 /* Simple class_wide types are always viewed as their root_type
3552 by Gigi unless an Equivalent_Type is specified. */
3556 else
3568 else
3580 /* Nothing at all to do here, so just return an ERROR_MARK and claim
3581 we've already saved it, so we don't try to. */
3588 }
3590 /* If we had a case where we evaluated another type and it might have
3591 defined this one, handle it here. */
3593 {
3596 }
3598 /* If we are processing a type and there is either no decl for it or
3599 we just made one, do some common processing for the type, such as
3600 handling alignment and possible padding. */
3603 {
3610 /* ??? Don't set the size for a String_Literal since it is either
3611 confirming or we don't handle it properly (if the low bound is
3612 non-constant). */
3617 /* If a size was specified, see if we can make a new type of that size
3618 by rearranging the type, for example from a fat to a thin pointer. */
3620 {
3621 gnu_type
3628 }
3630 /* If the alignment hasn't already been processed and this is
3631 not an unconstrained array, see if an alignment is specified.
3632 If not, we pick a default alignment for atomic objects. */
3634 ;
3648 /* See if we need to pad the type. If we did, and made a record,
3649 the name of the new type may be changed. So get it back for
3650 us when we make the new TYPE_DECL below. */
3655 {
3659 }
3663 /* If we are at global level, GCC will have applied variable_size to
3664 the type, but that won't have done anything. So, if it's not
3665 a constant or self-referential, call elaborate_expression_1 to
3666 make a variable for the size rather than calculating it each time.
3667 Handle both the RM size and the actual size. */
3672 {
3676 {
3683 }
3684 else
3685 {
3692 /* ??? For now, store the size as a multiple of the alignment
3693 in bytes so that we can see the alignment from the tree. */
3695 = build_binary_op
3697 elaborate_expression_1
3713 }
3714 }
3716 /* If this is a record type or subtype, call elaborate_expression_1 on
3717 any field position. Do this for both global and local types.
3718 Skip any fields that we haven't made trees for to avoid problems with
3719 class wide types. */
3724 {
3727 /* ??? Unfortunately, GCC needs to be able to prove the
3728 alignment of this offset and if it's a variable, it can't.
3729 In GCC 3.2, we'll use DECL_OFFSET_ALIGN in some way, but
3730 right now, we have to put in an explicit multiply and
3731 divide by that value. */
3735 = build_binary_op
3737 elaborate_expression_1
3746 }
3750 | (TYPE_QUAL_VOLATILE
3760 {
3764 debug_info_p);
3765 }
3766 else
3768 }
3771 {
3774 /* Back-annotate the Alignment of the type if not already in the
3775 tree. Likewise for sizes. */
3781 {
3782 /* If the size is self-referential, we annotate the maximum
3783 value of that size. */
3790 }
3794 }
3803 /* If this decl is really indirect, adjust it. */
3807 /* If we haven't already, associate the ..._DECL node that we just made with
3808 the input GNAT entity node. */
3812 /* If this is an enumeral or floating-point type, we were not able to set
3813 the bounds since they refer to the type. These bounds are always static.
3815 For enumeration types, also write debugging information and declare the
3816 enumeration literal table, if needed. */
3820 {
3823 /* If this is a padded type, we need to use the underlying type. */
3828 /* If this is a floating point type and we haven't set a floating
3829 point type yet, use this in the evaluation of the bounds. */
3839 {
3842 /* Since this has both a typedef and a tag, avoid outputting
3843 the name twice. */
3846 }
3847 }
3849 /* If we deferred processing of incomplete types, re-enable it. If there
3850 were no other disables and we have some to process, do so. */
3853 {
3859 {
3866 }
3867 }
3869 /* If we are not defining this type, see if it's in the incomplete list.
3870 If so, handle that list entry now. */
3872 {
3877 {
3881 }
3882 }
3885 force_global--;
3894 }
3895 \f
3896 /* Given GNAT_ENTITY, elaborate all expressions that are required to
3897 be elaborated at the point of its definition, but do nothing else. */
3899 void
3901 Entity_Id gnat_entity;
3902 {
3904 {
3911 {
3915 /* ??? Tests for avoiding static constaint error expression
3916 is needed until the front stops generating bogus conversions
3917 on bounds of real types. */
3926 }
3929 {
3933 /* If this is a record extension, go a level further to find the
3934 record definition. */
3937 }
3947 {
3948 Node_Id gnat_discriminant_expr;
3949 Entity_Id gnat_field;
3952 gnat_discriminant_expr
3957 /* ??? For now, ignore access discriminants. */
3960 gnat_entity,
3962 }
3965 }
3966 }
3967 \f
3968 /* Mark GNAT_ENTITY as going out of scope at this point. Recursively mark
3969 any entities on its entity chain similarly. */
3971 void
3973 Entity_Id gnat_entity;
3974 {
3975 Entity_Id gnat_sub_entity;
3978 /* If this has an entity list, process all in the list. */
3995 /* Now clear this if it has been defined, but only do so if it isn't
3996 a subprogram or parameter. We could refine this, but it isn't
3997 worth it. If this is statically allocated, it is supposed to
3998 hang around out of cope. */
4001 {
4004 }
4005 }
4006 \f
4007 /* Return a TREE_LIST describing the substitutions needed to reflect
4008 discriminant substitutions from GNAT_SUBTYPE to GNAT_TYPE and add
4009 them to GNU_LIST. If GNAT_TYPE is not specified, use the base type
4010 of GNAT_SUBTYPE. The substitions can be in any order. TREE_PURPOSE
4011 gives the tree for the discriminant and TREE_VALUES is the replacement
4012 value. They are in the form of operands to substitute_in_expr.
4013 DEFINITION is as in gnat_to_gnu_entity. */
4015 static tree
4017 Entity_Id gnat_subtype;
4018 Entity_Id gnat_type;
4019 tree gnu_list;
4021 {
4022 Entity_Id gnat_discrim;
4023 Node_Id gnat_value;
4034 /* Ignore access discriminants. */
4037 elaborate_expression
4041 gnu_list);
4044 }
4045 \f
4046 /* For the following two functions: for each GNAT entity, the GCC
4047 tree node used as a dummy for that entity, if any. */
4051 /* Initialize the above table. */
4053 void
4055 {
4056 Node_Id gnat_node;
4064 }
4066 /* Make a dummy type corresponding to GNAT_TYPE. */
4068 tree
4070 Entity_Id gnat_type;
4071 {
4072 Entity_Id gnat_underlying;
4073 tree gnu_type;
4075 /* Find a full type for GNAT_TYPE, taking into account any class wide
4076 types. */
4086 ;
4088 /* If it there already a dummy type, use that one. Else make one. */
4092 /* If this is a record, make this a RECORD_TYPE or UNION_TYPE; else make
4093 it a VOID_TYPE. */
4097 else
4109 }
4110 \f
4111 /* Return 1 if the size represented by GNU_SIZE can be handled by an
4112 allocation. If STATIC_P is non-zero, consider only what can be
4113 done with a static allocation. */
4115 static int
4117 tree gnu_size;
4119 {
4120 /* If this is not a static allocation, the only case we want to forbid
4121 is an overflowing size. That will be converted into a raise a
4122 Storage_Error. */
4127 /* Otherwise, we need to deal with both variable sizes and constant
4128 sizes that won't fit in a host int. */
4130 }
4131 \f
4132 /* Return a list of attributes for GNAT_ENTITY, if any. */
4136 Entity_Id gnat_entity;
4137 {
4139 Node_Id gnat_temp;
4144 {
4154 {
4156 (gnat_to_gnu
4163 (gnat_to_gnu
4164 (Expression
4167 }
4170 {
4189 }
4196 attr->error_point
4200 }
4203 }
4204 \f
4205 /* Get the unpadded version of a GNAT type. */
4207 tree
4209 Entity_Id gnat_entity;
4210 {
4217 }
4218 \f
4219 /* Called when we need to protect a variable object using a save_expr. */
4221 tree
4223 tree gnu_operand;
4224 Node_Id gnat_node;
4225 {
4231 /* If we will be generating code, make sure we are at the proper
4232 line number. */
4240 else
4242 }
4243 \f
4244 /* Given a GNAT tree GNAT_EXPR, for an expression which is a value within a
4245 type definition (either a bound or a discriminant value) for GNAT_ENTITY,
4246 return the GCC tree to use for that expression. GNU_NAME is the
4247 qualification to use if an external name is appropriate and DEFINITION is
4248 nonzero if this is a definition of GNAT_ENTITY. If NEED_VALUE is nonzero,
4249 we need a result. Otherwise, we are just elaborating this for
4250 side-effects. If NEED_DEBUG is nonzero we need the symbol for debugging
4251 purposes even if it isn't needed for code generation. */
4253 static tree
4256 Node_Id gnat_expr;
4257 Entity_Id gnat_entity;
4258 tree gnu_name;
4262 {
4263 tree gnu_expr;
4265 /* If we already elaborated this expression (e.g., it was involved
4266 in the definition of a private type), use the old value. */
4270 /* If we don't need a value and this is static or a discriment, we
4271 don't need to do anything. */
4278 /* Otherwise, convert this tree to its GCC equivalant. */
4279 gnu_expr
4283 /* Save the expression in case we try to elaborate this entity again.
4284 Since this is not a DECL, don't check it. If this is a constant,
4285 don't save it since GNAT_EXPR might be used more than once. Also,
4286 don't save if it's a discriminant. */
4291 }
4293 /* Similar, but take a GNU expression. */
4295 static tree
4297 need_debug)
4298 Node_Id gnat_expr;
4299 Entity_Id gnat_entity;
4300 tree gnu_expr;
4301 tree gnu_name;
4304 {
4306 /* Strip any conversions to see if the expression is a readonly variable.
4307 ??? This really should remain readonly, but we have to think about
4308 the typing of the tree here. */
4313 /* In most cases, we won't see a naked FIELD_DECL here because a
4314 discriminant reference will have been replaced with a COMPONENT_REF
4315 when the type is being elaborated. However, there are some cases
4316 involving child types where we will. So convert it to a COMPONENT_REF
4317 here. We have to hope it will be at the highest level of the
4318 expression in these cases. */
4322 gnu_expr);
4324 /* If GNU_EXPR is neither a placeholder nor a constant, nor a variable
4325 that is a constant, make a variable that is initialized to contain the
4326 bound when the package containing the definition is elaborated. If
4327 this entity is defined at top level and a bound or discriminant value
4328 isn't a constant or a reference to a discriminant, replace the bound
4329 by the variable; otherwise use a SAVE_EXPR if needed. Note that we
4330 rely here on the fact that an expression cannot contain both the
4331 discriminant and some other variable. */
4338 /* If this is a static expression or contains a discriminant, we don't
4339 need the variable for debugging (and can't elaborate anyway if a
4340 discriminant). */
4346 /* Now create the variable if we need it. */
4348 {
4350 gnu_decl
4355 }
4357 /* We only need to use this variable if we are in global context since GCC
4358 can do the right thing in the local case. */
4363 else
4365 }
4366 \f
4367 /* Create a record type that contains a field of TYPE with a starting bit
4368 position so that it is aligned to ALIGN bits and is SIZE bytes long. */
4370 tree
4372 tree type;
4374 tree size;
4375 {
4380 place));
4389 /* The bit position is obtained by "and"ing the alignment minus 1
4390 with the two's complement of the address and multiplying
4391 by the number of bits per unit. Do all this in sizetype. */
4397 size_addr_place),
4400 bitsize_unit_node);
4411 bitsize_unit_node),
4417 }
4418 \f
4419 /* TYPE is a RECORD_TYPE with BLKmode that's being used as the field
4420 type of a packed record. See if we can rewrite it as a record that has
4421 a non-BLKmode type, which we can pack tighter. If so, return the
4422 new type. If not, return the original type. */
4424 static tree
4426 tree type;
4427 {
4430 tree old_field;
4432 /* Copy the name and flags from the old type to that of the new and set
4433 the alignment to try for an integral type. */
4443 /* Now copy the fields, keeping the position and size. */
4446 {
4447 tree new_field
4460 }
4464 }
4465 \f
4466 /* Ensure that TYPE has SIZE and ALIGN. Make and return a new padded type
4467 if needed. We have already verified that SIZE and TYPE are large enough.
4469 GNAT_ENTITY and NAME_TRAILER are used to name the resulting record and
4470 to issue a warning.
4472 IS_USER_TYPE is nonzero if we must be sure we complete the original type.
4474 DEFINITION is nonzero if this type is being defined.
4476 SAME_RM_SIZE is nonzero if the RM_Size of the resulting type is to be
4477 set to its TYPE_SIZE; otherwise, it's set to the RM_Size of the original
4478 type. */
4480 static tree
4483 tree type;
4484 tree size;
4486 Entity_Id gnat_entity;
4491 {
4493 tree record;
4494 tree field;
4496 /* If TYPE is a padded type, see if it agrees with any size and alignment
4497 we were given. If so, return the original type. Otherwise, strip
4498 off the padding, since we will either be returning the inner type
4499 or repadding it. If no size or alignment is specified, use that of
4500 the original padded type. */
4503 {
4520 }
4522 /* If the size is either not being changed or is being made smaller (which
4523 is not done here (and is only valid for bitfields anyway), show the size
4524 isn't changing. Likewise, clear the alignment if it isn't being
4525 changed. Then return if we aren't doing anything. */
4539 /* We used to modify the record in place in some cases, but that could
4540 generate incorrect debugging information. So make a new record
4541 type and name. */
4547 /* If we were making a type, complete the original type and give it a
4548 name. */
4556 /* If we are changing the alignment and the input type is a record with
4557 BLKmode and a small constant size, try to make a form that has an
4558 integral mode. That might allow this record to have an integral mode,
4559 which will be much more efficient. There is no point in doing this if a
4560 size is specified unless it is also smaller than the biggest alignment
4561 and it is incorrect to do this if the size of the original type is not a
4562 multiple of the alignment. */
4582 bitsize_unit_node));
4589 /* Keep the RM_Size of the padded record as that of the old record
4590 if requested. */
4593 /* Unless debugging information isn't being written for the input type,
4594 write a record that shows what we are a subtype of and also make a
4595 variable that indicates our size, if variable. */
4600 {
4619 }
4627 /* If the size was widened explicitly, maybe give a warning. */
4633 {
4646 /* Generate message only for entities that come from source, since
4647 if we have an entity created by expansion, the message will be
4648 generated for some other corresponding source entity. */
4651 gnat_entity,
4658 }
4661 }
4662 \f
4663 /* Given a GNU tree and a GNAT list of choices, generate an expression to test
4664 the value passed against the list of choices. */
4666 tree
4668 tree operand;
4669 Node_Id choices;
4670 {
4671 Node_Id choice;
4672 Node_Id gnat_temp;
4677 {
4679 {
4684 /* There's no good type to use here, so we might as well use
4685 integer_type_node. */
4686 this_test
4700 this_test
4710 /* This represents either a subtype range, an enumeration
4711 literal, or a constant Ekind says which. If an enumeration
4712 literal or constant, fall through to the next case. */
4715 {
4721 this_test
4728 }
4729 /* ... fall through ... */
4734 single);
4743 }
4747 }
4750 }
4751 \f
4752 /* Return a GCC tree for a field corresponding to GNAT_FIELD to be
4753 placed in GNU_RECORD_TYPE.
4755 PACKED is 1 if the enclosing record is packed and -1 if the enclosing
4756 record has a Component_Alignment of Storage_Unit.
4758 DEFINITION is nonzero if this field is for a record being defined. */
4760 static tree
4762 Entity_Id gnat_field;
4763 tree gnu_record_type;
4766 {
4772 tree gnu_field;
4773 int needs_strict_alignment
4777 /* If this field requires strict alignment pretend it isn't packed. */
4781 /* For packed records, this is one of the few occasions on which we use
4782 the official RM size for discrete or fixed-point components, instead
4783 of the normal GNAT size stored in Esize. See description in Einfo:
4784 "Handling of Type'Size Values" for further details. */
4794 /* If the field's type is a left-justified modular type, make the field
4795 the type of the inner object unless it is aliases. We don't need
4796 the the wrapper here and it can prevent packing. */
4801 /* If we are packing this record or we have a specified size that's
4802 smaller than that of the field type and the field type is also a record
4803 that's BLKmode and with a small constant size, see if we can get a
4804 better form of the type that allows more packing. If we can, show
4805 a size was specified for it if there wasn't one so we know to
4806 make this a bitfield and avoid making things wider. */
4811 && (packed
4814 {
4819 }
4822 {
4827 /* Ensure the position does not overlap with the parent subtype,
4828 if there is one. */
4830 {
4831 tree gnu_parent
4837 {
4838 post_error_ne_tree
4842 }
4843 }
4845 /* If this field needs strict alignment, ensure the record is
4846 sufficiently aligned and that that position and size are
4847 consistent with the alignment. */
4849 {
4856 /* If Atomic, the size must match exactly and if aliased, the size
4857 must not be less than the rounded size. */
4860 {
4861 post_error_ne_tree
4867 }
4872 {
4873 post_error_ne_tree
4876 gnu_min_size);
4878 }
4883 {
4885 post_error_ne_num
4891 post_error_ne_num
4897 post_error_ne_num
4901 else
4905 }
4907 /* If an error set the size to zero, show we have no position
4908 either. */
4911 }
4918 bitsize_unit_node))))
4919 {
4920 /* Try to see if we can make this a packable type. If we
4921 can, it's OK. */
4926 {
4931 }
4932 }
4933 }
4935 /* If the record has rep clauses and this is the tag field, make a rep
4936 clause for it as well. */
4939 {
4942 }
4944 /* We need to make the size the maximum for the type if it is
4945 self-referential and an unconstrained type. In that case, we can't
4946 pack the field since we can't make a copy to align it. */
4952 {
4955 }
4957 /* If no size is specified (or if there was an error), don't specify a
4958 position. */
4961 else
4962 {
4963 /* Unless this field is aliased, we can remove any left-justified
4964 modular type since it's only needed in the unchecked conversion
4965 case, which doesn't apply here. */
4971 gnu_field_type
4976 }
4994 }
4995 \f
4996 /* Return a GCC tree for a record type given a GNAT Component_List and a chain
4997 of GCC trees for fields that are in the record and have already been
4998 processed. When called from gnat_to_gnu_entity during the processing of a
4999 record type definition, the GCC nodes for the discriminants will be on
5000 the chain. The other calls to this function are recursive calls from
5001 itself for the Component_List of a variant and the chain is empty.
5003 PACKED is 1 if this is for a record with "pragma pack" and -1 is this is
5004 for a record type with "pragma component_alignment (storage_unit)".
5006 FINISH_RECORD is nonzero if this call will supply all of the remaining
5007 fields of the record.
5009 P_GNU_REP_LIST, if nonzero, is a pointer to a list to which each field
5010 with a rep clause is to be added. If it is nonzero, that is all that
5011 should be done with such fields.
5013 CANCEL_ALIGNMENT, if nonzero, means the alignment should be zeroed
5014 before laying out the record. This means the alignment only serves
5015 to force fields to be bitfields, but not require the record to be
5016 that aligned. This is used for variants.
5018 ALL_REP, if nonzero, means that a rep clause was found for all the
5019 fields. This simplifies the logic since we know we're not in the mixed
5020 case.
5022 The processing of the component list fills in the chain with all of the
5023 fields of the record and then the record type is finished. */
5025 static void
5028 tree gnu_record_type;
5029 Node_Id component_list;
5030 tree gnu_field_list;
5036 {
5037 Node_Id component_decl;
5038 Entity_Id gnat_field;
5039 Node_Id variant_part;
5040 Node_Id variant;
5045 /* For each variable within each component declaration create a GCC field
5046 and add it to the list, skipping any pragmas in the list. */
5052 {
5057 else
5058 {
5062 /* If this is the _Tag field, put it before any discriminants,
5063 instead of after them as is the case for all other fields. */
5066 else
5067 {
5070 }
5071 }
5074 }
5076 /* At the end of the component list there may be a variant part. */
5079 /* If this is an unchecked union, each variant must have exactly one
5080 component, each of which becomes one component of this union. */
5085 {
5086 component_decl
5090 definition);
5094 }
5096 /* We create a QUAL_UNION_TYPE for the variant part since the variants are
5097 mutually exclusive and should go in the same memory. To do this we need
5098 to treat each variant as a record whose elements are created from the
5099 component list for the variant. So here we create the records from the
5100 lists for the variants and put them all into the QUAL_UNION_TYPE. */
5102 {
5104 Node_Id variant;
5106 tree gnu_union_field;
5109 tree gnu_var_name
5110 = concat_id_with_name
5124 {
5126 tree gnu_inner_name;
5127 tree gnu_qual;
5135 /* Set the alignment of the inner type in case we need to make
5136 inner objects into bitfields, but then clear it out
5137 so the record actually gets only the alignment required. */
5154 }
5156 /* We can delete any empty variants from the end. This may leave none
5157 left. Note we cannot delete variants from anywhere else. */
5162 /* Only make the QUAL_UNION_TYPE if there are any non-empty variants. */
5164 {
5168 gnu_union_field
5170 packed,
5177 }
5178 }
5180 /* Scan GNU_FIELD_LIST and see if any fields have rep clauses. If they
5181 do, pull them out and put them into GNU_OUR_REP_LIST. We have to do this
5182 in a separate pass since we want to handle the discriminants but can't
5183 play with them until we've used them in debugging data above.
5185 ??? Note: if we then reorder them, debugging information will be wrong,
5186 but there's nothing that can be done about this at the moment. */
5189 {
5191 {
5196 else
5202 }
5203 else
5204 {
5207 }
5208 }
5210 /* If we have any items in our rep'ed field list, it is not the case that all
5211 the fields in the record have rep clauses, and P_REP_LIST is nonzero,
5212 set it and ignore the items. Otherwise, sort the fields by bit position
5213 and put them into their own record if we have any fields without
5214 rep clauses. */
5218 {
5219 tree gnu_rep_type
5225 /* Set DECL_SECTION_NAME to increasing integers so we have a
5226 stable sort. */
5229 {
5232 }
5236 /* Put the fields in the list in order of increasing position, which
5237 means we start from the end. */
5240 {
5245 }
5248 {
5254 }
5255 else
5256 {
5259 }
5260 }
5267 }
5268 \f
5269 /* Called via qsort from the above. Returns -1, 1, depending on the
5270 bit positions and ordinals of the two fields. */
5272 static int
5276 {
5281 return
5286 else
5288 }
5289 \f
5290 /* Given GNU_SIZE, a GCC tree representing a size, return a Uint to be
5291 placed into an Esize, Component_Bit_Offset, or Component_Size value
5292 in the GNAT tree. */
5294 static Uint
5296 tree gnu_size;
5297 {
5299 TCode tcode;
5304 /* If we do not return inside this switch, TCODE will be set to the
5305 code to use for a Create_Node operand and LEN (set above) will be
5306 the number of recursive calls for us to make. */
5309 {
5314 /* This may have come from a conversion from some smaller type,
5315 so ensure this is in bitsizetype. */
5318 /* For negative values, use NEGATE_EXPR of the supplied value. */
5320 {
5321 /* The rediculous code below is to handle the case of the largest
5322 negative integer. */
5325 tree temp;
5328 {
5329 negative_size
5332 bitsize_one_node));
5334 }
5341 }
5348 /* This peculiar test is to make sure that the size fits in an int
5349 on machines where HOST_WIDE_INT is not "int". */
5352 else
5356 /* The only case we handle here is a simple discriminant reference. */
5364 else
5370 /* Now just list the operations we handle. */
5401 }
5403 /* Now get each of the operands that's relevant for this code. If any
5404 cannot be expressed as a repinfo node, say we can't. */
5409 {
5413 }
5416 }
5418 /* Given GNAT_ENTITY, a record type, and GNU_TYPE, its corresponding
5419 GCC type, set Component_Bit_Offset and Esize to the position and size
5420 used by Gigi. */
5422 static void
5424 Entity_Id gnat_entity;
5425 tree gnu_type;
5426 {
5427 tree gnu_list;
5428 tree gnu_entry;
5429 Entity_Id gnat_field;
5431 /* We operate by first making a list of all field and their positions
5432 (we can get the sizes easily at any time) by a recursive call
5433 and then update all the sizes into the tree. */
5436 BIGGEST_ALIGNMENT);
5445 gnu_list)))
5446 {
5447 Set_Component_Bit_Offset
5456 }
5457 }
5459 /* Scan all fields in GNU_TYPE and build entries where TREE_PURPOSE is the
5460 FIELD_DECL and TREE_VALUE a TREE_LIST with TREE_PURPOSE being the byte
5461 position and TREE_VALUE being a TREE_LIST with TREE_PURPOSE the value to be
5462 placed into DECL_OFFSET_ALIGN and TREE_VALUE the bit position. GNU_POS is
5463 to be added to the position, GNU_BITPOS to the bit position, OFFSET_ALIGN is
5464 the present value of DECL_OFFSET_ALIGN and GNU_LIST is a list of the entries
5465 so far. */
5467 static tree
5469 tree gnu_type;
5470 tree gnu_list;
5471 tree gnu_pos;
5472 tree gnu_bitpos;
5474 {
5475 tree gnu_field;
5480 {
5485 unsigned int our_offset_align
5488 gnu_result
5493 NULL_TREE),
5494 gnu_result);
5497 gnu_result
5500 our_offset_align);
5501 }
5504 }
5505 \f
5506 /* UINT_SIZE is a Uint giving the specified size for an object of GNU_TYPE
5507 corresponding to GNAT_OBJECT. If size is valid, return a tree corresponding
5508 to its value. Otherwise return 0. KIND is VAR_DECL is we are specifying
5509 the size for an object, TYPE_DECL for the size of a type, and FIELD_DECL
5510 for the size of a field. COMPONENT_P is true if we are being called
5511 to process the Component_Size of GNAT_OBJECT. This is used for error
5512 message handling and to indicate to use the object size of GNU_TYPE.
5513 ZERO_OK is nonzero if a size of zero is permitted; if ZERO_OK is zero,
5514 it means that a size of zero should be treated as an unspecified size. */
5516 static tree
5518 Uint uint_size;
5519 tree gnu_type;
5520 Entity_Id gnat_object;
5524 {
5525 Node_Id gnat_error_node;
5526 tree type_size
5528 tree size;
5543 else
5546 /* Don't give errors on packed array types; we'll be giving the error on
5547 the type itself soon enough. */
5551 /* Get the size as a tree. Return 0 if none was specified, either because
5552 Esize was not Present or if the specified size was zero. Give an error
5553 if a size was specified, but cannot be represented as in sizetype. If
5554 the size is negative, it was a back-annotation of a variable size and
5555 should be treated as not specified. */
5561 {
5565 else
5569 }
5571 /* Ignore a negative size since that corresponds to our back-annotation.
5572 Also ignore a zero size unless a size clause exists. */
5576 /* The size of objects is always a multiple of a byte. */
5579 bitsize_unit_node)))
5580 {
5584 else
5588 }
5590 /* If this is an integral type, the front-end has verified the size, so we
5591 need not do it here (which would entail checking against the bounds).
5592 However, if this is an aliased object, it may not be smaller than the
5593 type of the object. */
5598 /* If the object is a record that contains a template, add the size of
5599 the template to the specified size. */
5604 /* If the size of the object is a constant, the new size must not be
5605 smaller. */
5609 {
5611 post_error_ne_tree
5614 else
5621 post_error_ne_tree_2
5631 }
5634 }
5635 \f
5636 /* Similarly, but both validate and process a value of RM_Size. This
5637 routine is only called for types. */
5639 static void
5641 Uint uint_size;
5642 tree gnu_type;
5643 Entity_Id gnat_entity;
5644 {
5645 /* Only give an error if a Value_Size clause was explicitly given.
5646 Otherwise, we'd be duplicating an error on the Size clause. */
5647 Node_Id gnat_attr_node
5650 tree size;
5652 /* Get the size as a tree. Do nothing if none was specified, either
5653 because RM_Size was not Present or if the specified size was zero.
5654 Give an error if a size was specified, but cannot be represented as
5655 in sizetype. */
5661 {
5664 gnat_entity);
5667 }
5669 /* Ignore a negative size since that corresponds to our back-annotation.
5670 Also ignore a zero size unless a size clause exists, a Value_Size
5671 clause exists, or this is an integer type, in which case the
5672 front end will have always set it. */
5679 /* If the old size is self-referential, get the maximum size. */
5684 /* If the size of the object is a constant, the new size must not be
5685 smaller (the front end checks this for scalar types). */
5690 {
5692 post_error_ne_tree
5697 }
5699 /* Otherwise, set the RM_Size. */
5710 }
5711 \f
5712 /* Given a type TYPE, return a new type whose size is appropriate for SIZE.
5713 If TYPE is the best type, return it. Otherwise, make a new type. We
5714 only support new integral and pointer types. BIASED_P is nonzero if
5715 we are making a biased type. */
5717 static tree
5719 tree type;
5720 tree size_tree;
5722 {
5723 tree new_type;
5726 /* If size indicates an error, just return TYPE to avoid propagating the
5727 error. Likewise if it's too large to represent. */
5733 {
5736 /* Only do something if the type is not already the proper size and is
5737 not a packed array type. */
5762 /* Do something if this is a fat pointer, in which case we
5763 may need to return the thin pointer. */
5765 return
5766 build_pointer_type
5771 /* Only do something if this is a thin pointer, in which case we
5772 may need to return the fat pointer. */
5774 return
5781 }
5784 }
5785 \f
5786 /* ALIGNMENT is a Uint giving the alignment specified for GNAT_ENTITY,
5787 a type or object whose present alignment is ALIGN. If this alignment is
5788 valid, return it. Otherwise, give an error and return ALIGN. */
5790 static unsigned int
5792 Uint alignment;
5793 Entity_Id gnat_entity;
5795 {
5799 #ifndef MAX_OFILE_ALIGNMENT
5800 #define MAX_OFILE_ALIGNMENT BIGGEST_ALIGNMENT
5801 #endif
5806 /* Don't worry about checking alignment if alignment was not specified
5807 by the source program and we already posted an error for this entity. */
5812 /* Within GCC, an alignment is an integer, so we must make sure a
5813 value is specified that fits in that range. Also, alignments of
5814 more than MAX_OFILE_ALIGNMENT can't be supported. */
5828 else
5832 }
5833 \f
5834 /* Verify that OBJECT, a type or decl, is something we can implement
5835 atomically. If not, give an error for GNAT_ENTITY. COMP_P is nonzero
5836 if we require atomic components. */
5838 static void
5840 tree object;
5841 Entity_Id gnat_entity;
5843 {
5845 Node_Id gnat_node;
5848 tree size;
5850 /* There are three case of what OBJECT can be. It can be a type, in which
5851 case we take the size, alignment and mode from the type. It can be a
5852 declaration that was indirect, in which case the relevant values are
5853 that of the type being pointed to, or it can be a normal declaration,
5854 in which case the values are of the decl. The code below assumes that
5855 OBJECT is either a type or a decl. */
5857 {
5861 }
5863 {
5867 }
5868 else
5869 {
5873 }
5875 /* Consider all floating-point types atomic and any types that that are
5876 represented by integers no wider than a machine word. */
5883 /* For the moment, also allow anything that has an alignment equal
5884 to its size and which is smaller than a word. */
5892 {
5900 }
5905 else
5908 }
5909 \f
5910 /* Given a type T, a FIELD_DECL F, and a replacement value R,
5911 return a new type with all size expressions that contain F
5912 updated by replacing F with R. This is identical to GCC's
5913 substitute_in_type except that it knows about TYPE_INDEX_TYPE.
5914 If F is NULL_TREE, always make a new RECORD_TYPE, even if nothing has
5915 changed. */
5917 tree
5920 {
5922 tree tem;
5925 {
5934 {
5946 }
5957 {
5971 }
5987 /* Don't know how to do these yet. */
5991 {
6005 }
6010 {
6011 tree field;
6012 int changed_field
6019 /* Start out with no fields, make new fields, and chain them
6020 in. If we haven't actually changed the type of any field,
6021 discard everything we've done and return the old type. */
6028 {
6039 /* If this is an internal field and the type of this field is
6040 a UNION_TYPE or RECORD_TYPE with no elements, ignore it. If
6041 the type just has one element, treat that as the field.
6042 But don't do this if we are processing a QUAL_UNION_TYPE. */
6047 {
6052 {
6053 tree next_new_field
6056 /* Make sure omitting the union doesn't change
6057 the layout. */
6060 }
6061 }
6068 /* If the size of the old field was set at a constant,
6069 propagate the size in case the type's size was variable.
6070 (This occurs in the case of a variant or discriminated
6071 record with a default size used as a field of another
6072 record.) */
6081 {
6087 /* Do the substitution inside the qualifier and if we find
6088 that this field will not be present, omit it. */
6093 }
6097 else
6102 /* If this is a qualified type and this field will always be
6103 present, we are done. */
6107 }
6109 /* If this used to be a qualified union type, but we now know what
6110 field will be present, make this a normal union. */
6123 /* If the size was originally a constant use it. */
6126 {
6130 }
6133 }
6137 }
6138 }
6139 \f
6140 /* Return the "RM size" of GNU_TYPE. This is the actual number of bits
6141 needed to represent the object. */
6143 tree
6145 tree gnu_type;
6146 {
6147 /* For integer types, this is the precision. For record types, we store
6148 the size explicitly. For other types, this is just the size. */
6154 /* Return the rm_size of the actual data plus the size of the template. */
6155 return
6165 else
6167 }
6168 \f
6169 /* Return an identifier representing the external name to be used for
6170 GNAT_ENTITY. If SUFFIX is specified, the name is followed by "___"
6171 and the specified suffix. */
6173 tree
6175 Entity_Id gnat_entity;
6177 {
6185 }
6187 /* Return the name to be used for GNAT_ENTITY. If a type, create a
6188 fully-qualified name, possibly with type information encoding.
6189 Otherwise, return the name. */
6191 tree
6193 Entity_Id gnat_entity;
6194 {
6197 }
6199 /* Given GNU_ID, an IDENTIFIER_NODE containing a name and SUFFIX, a
6200 string, return a new IDENTIFIER_NODE that is the concatenation of
6201 the name in GNU_ID and SUFFIX. */
6203 tree
6205 tree gnu_id;
6207 {
6216 }