| blob | 5b0581fd819d0b5ab37c067b45b63d6d5ce5ee93 |
1 /****************************************************************************
2 * *
3 * GNAT COMPILER COMPONENTS *
4 * *
5 * D E C L *
6 * *
7 * C Implementation File *
8 * *
9 * Copyright (C) 1992-2004, Free Software Foundation, Inc. *
10 * *
11 * GNAT is free software; you can redistribute it and/or modify it under *
12 * terms of the GNU General Public License as published by the Free Soft- *
13 * ware Foundation; either version 2, or (at your option) any later ver- *
14 * sion. GNAT is distributed in the hope that it will be useful, but WITH- *
15 * OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY *
16 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License *
17 * for more details. You should have received a copy of the GNU General *
18 * Public License distributed with GNAT; see file COPYING. If not, write *
19 * to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, *
20 * MA 02111-1307, USA. *
21 * *
22 * GNAT was originally developed by the GNAT team at New York University. *
23 * Extensive contributions were provided by Ada Core Technologies Inc. *
24 * *
25 ****************************************************************************/
55 /* Provide default values for the macros controlling stack checking.
56 This is copied from GCC's expr.h. */
58 #ifndef STACK_CHECK_BUILTIN
59 #define STACK_CHECK_BUILTIN 0
60 #endif
61 #ifndef STACK_CHECK_PROBE_INTERVAL
62 #define STACK_CHECK_PROBE_INTERVAL 4096
63 #endif
64 #ifndef STACK_CHECK_MAX_FRAME_SIZE
65 #define STACK_CHECK_MAX_FRAME_SIZE \
66 (STACK_CHECK_PROBE_INTERVAL - UNITS_PER_WORD)
67 #endif
68 #ifndef STACK_CHECK_MAX_VAR_SIZE
69 #define STACK_CHECK_MAX_VAR_SIZE (STACK_CHECK_MAX_FRAME_SIZE / 100)
70 #endif
72 /* These two variables are used to defer recursively expanding incomplete
73 types while we are processing a record or subprogram type. */
76 static struct incomplete
77 {
79 tree old_type;
80 Entity_Id full_type;
105 \f
106 /* Given GNAT_ENTITY, an entity in the incoming GNAT tree, return a
107 GCC type corresponding to that entity. GNAT_ENTITY is assumed to
108 refer to an Ada type. */
110 tree
112 {
113 tree gnu_decl;
115 /* The back end never attempts to annotate generic types */
119 /* Convert the ada entity type into a GCC TYPE_DECL node. */
125 }
126 \f
127 /* Given GNAT_ENTITY, a GNAT defining identifier node, which denotes some Ada
128 entity, this routine returns the equivalent GCC tree for that entity
129 (an ..._DECL node) and associates the ..._DECL node with the input GNAT
130 defining identifier.
132 If GNAT_ENTITY is a variable or a constant declaration, GNU_EXPR gives its
133 initial value (in GCC tree form). This is optional for variables.
134 For renamed entities, GNU_EXPR gives the object being renamed.
136 DEFINITION is nonzero if this call is intended for a definition. This is
137 used for separate compilation where it necessary to know whether an
138 external declaration or a definition should be created if the GCC equivalent
139 was not created previously. The value of 1 is normally used for a non-zero
140 DEFINITION, but a value of 2 is used in special circumstances, defined in
141 the code. */
143 tree
145 {
146 tree gnu_entity_id;
148 /* Contains the gnu XXXX_DECL tree node which is equivalent to the input
149 GNAT tree. This node will be associated with the GNAT node by calling
150 the save_gnu_tree routine at the end of the `switch' statement. */
152 /* Nonzero if we have already saved gnu_decl as a gnat association. */
154 /* Nonzero if we incremented defer_incomplete_level. */
156 /* Nonzero if we incremented force_global. */
158 /* Nonzero if we should check to see if elaborated during processing. */
160 /* Nonzero if we made GNU_DECL and its type here. */
166 Entity_Id gnat_temp;
167 unsigned int esize
177 int imported_p
182 /* Since a use of an Itype is a definition, process it as such if it
183 is not in a with'ed unit. */
188 {
189 /* Ensure that we are in a subprogram mentioned in the Scope
190 chain of this entity, our current scope is global,
191 or that we encountered a task or entry (where we can't currently
192 accurately check scoping). */
195 {
198 }
202 {
207 gnat_temp
219 && (current_function_decl
221 {
224 }
225 }
227 /* gigi abort 122 means that the entity "gnat_entity" has an incorrect
228 scope, i.e. that its scope does not correspond to the subprogram
229 in which it is declared */
231 }
233 /* If this is entity 0, something went badly wrong. */
237 /* If we've already processed this entity, return what we got last time.
238 If we are defining the node, we should not have already processed it.
239 In that case, we will abort below when we try to save a new GCC tree for
240 this object. We also need to handle the case of getting a dummy type
241 when a Full_View exists. */
244 && (! definition
246 {
253 {
259 }
262 }
264 /* If this is a numeric or enumeral type, or an access type, a nonzero
265 Esize must be specified unless it was specified by the programmer. */
274 /* Likewise, RM_Size must be specified for all discrete and fixed-point
275 types. */
280 /* Get the name of the entity and set up the line number and filename of
281 the original definition for use in any decl we make. */
286 /* If we get here, it means we have not yet done anything with this
287 entity. If we are not defining it here, it must be external,
288 otherwise we should have defined it already. */
290 && ! type_annotate_only
294 #if 1
296 #endif
297 )
300 /* For cases when we are not defining (i.e., we are referencing from
301 another compilation unit) Public entities, show we are at global level
302 for the purpose of computing sizes. Don't do this for components or
303 discriminants since the relevant test is whether or not the record is
304 being defined. */
310 /* Handle any attributes. */
315 {
317 /* If this is a use of a deferred constant, get its full
318 declaration. */
320 {
325 }
327 /* If we have an external constant that we are not defining,
328 get the expression that is was defined to represent. We
329 may throw that expression away later if it is not a
330 constant.
331 Do not retrieve the expression if it is an aggregate, because
332 in complex instantiation contexts it may not be expanded */
341 /* Ignore deferred constant definitions; they are processed fully in the
342 front-end. For deferred constant references, get the full
343 definition. On the other hand, constants that are renamings are
344 handled like variable renamings. If No_Initialization is set, this is
345 not a deferred constant but a constant whose value is built
346 manually. */
351 {
355 }
358 {
363 }
368 /* We used to special case VMS exceptions here to directly map them to
369 their associated condition code. Since this code had to be masked
370 dynamically to strip off the severity bits, this caused trouble in
371 the GCC/ZCX case because the "type" pointers we store in the tables
372 have to be static. We now don't special case here anymore, and let
373 the regular processing take place, which leaves us with a regular
374 exception data object for VMS exceptions too. The condition code
375 mapping is taken care of by the front end and the bitmasking by the
376 runtime library. */
381 {
382 /* The GNAT record where the component was defined. */
385 /* If the variable is an inherited record component (in the case of
386 extended record types), just return the inherited entity, which
387 must be a FIELD_DECL. Likewise for discriminants.
388 For discriminants of untagged records which have explicit
389 stored discriminants, return the entity for the corresponding
390 stored discriminant. Also use Original_Record_Component
391 if the record has a private extension. */
399 {
400 gnu_decl
405 }
407 /* If the enclosing record has explicit stored discriminants,
408 then it is an untagged record. If the Corresponding_Discriminant
409 is not empty then this must be a renamed discriminant and its
410 Original_Record_Component must point to the corresponding explicit
411 stored discriminant (i.e., we should have taken the previous
412 branch). */
416 {
417 /* A tagged record has no explicit stored discriminants. */
423 gnu_decl
428 }
430 /* If the enclosing record has explicit stored discriminants,
431 then it is an untagged record. If the Corresponding_Discriminant
432 is not empty then this must be a renamed discriminant and its
433 Original_Record_Component must point to the corresponding explicit
434 stored discriminant (i.e., we should have taken the first
435 branch). */
442 /* Otherwise, if we are not defining this and we have no GCC type
443 for the containing record, make one for it. Then we should
444 have made our own equivalent. */
446 {
447 /* ??? If this is in a record whose scope is a protected
448 type and we have an Original_Record_Component, use it.
449 This is a workaround for major problems in protected type
450 handling. */
458 {
459 gnu_decl
465 }
471 }
473 /* Here we have no GCC type and this is a reference rather than a
474 definition. This should never happen. Most likely the cause is a
475 reference before declaration in the gnat tree for gnat_entity. */
476 else
478 }
484 /* Simple variables, loop variables, OUT parameters, and exceptions. */
485 object:
486 {
488 int const_flag
501 {
505 else
507 }
509 /* Get the type after elaborating the renamed object. */
512 /* If this is a loop variable, its type should be the base type.
513 This is because the code for processing a loop determines whether
514 a normal loop end test can be done by comparing the bounds of the
515 loop against those of the base type, which is presumed to be the
516 size used for computation. But this is not correct when the size
517 of the subtype is smaller than the type. */
521 /* Reject non-renamed objects whose types are unconstrained arrays or
522 any object whose type is a dummy type or VOID_TYPE. */
528 {
531 else
533 }
535 /* If we are defining the object, see if it has a Size value and
536 validate it if so. If we are not defining the object and a Size
537 clause applies, simply retrieve the value. We don't want to ignore
538 the clause and it is expected to have been validated already. Then
539 get the new type, if any. */
548 {
549 gnu_type
555 }
557 /* If this object has self-referential size, it must be a record with
558 a default value. We are supposed to allocate an object of the
559 maximum size in this case unless it is a constant with an
560 initializing expression, in which case we can get the size from
561 that. Note that the resulting size may still be a variable, so
562 this may end up with an indirect allocation. */
566 {
568 gnu_size
569 = SUBSTITUTE_PLACEHOLDER_IN_EXPR
572 /* We may have no GNU_EXPR because No_Initialization is
573 set even though there's an Expression. */
578 gnu_size
580 (Etype
582 else
584 }
586 /* If the size is zero bytes, make it one byte since some linkers have
587 trouble with zero-sized objects. If the object will have a
588 template, that will make it nonzero so don't bother. Also avoid
589 doing that for an object renaming or an object with an address
590 clause, as we would lose useful information on the view size
591 (e.g. for null array slices) and we are not allocating the object
592 here anyway. */
602 /* If an alignment is specified, use it if valid. Note that
603 exceptions are objects but don't have alignments. */
605 {
609 align
612 }
614 /* If this is an atomic object with no specified size and alignment,
615 but where the size of the type is a constant, set the alignment to
616 the lowest power of two greater than the size, or to the
617 biggest meaningful alignment, whichever is smaller. */
621 {
624 BIGGEST_ALIGNMENT))
626 else
631 }
633 /* If the object is set to have atomic components, find the component
634 type and validate it.
636 ??? Note that we ignore Has_Volatile_Components on objects; it's
637 not at all clear what to do in that case. */
640 {
641 tree gnu_inner
650 }
652 /* Now check if the type of the object allows atomic access. Note
653 that we must test the type, even if this object has size and
654 alignment to allow such access, because we will be going
655 inside the padded record to assign to the object. We could fix
656 this by always copying via an intermediate value, but it's not
657 clear it's worth the effort. */
661 /* If this is an aliased object with an unconstrained nominal subtype,
662 make a type that includes the template. */
666 {
667 tree gnu_fat
669 tree gnu_temp_type
672 gnu_type
676 }
678 #ifdef MINIMUM_ATOMIC_ALIGNMENT
679 /* If the size is a constant and no alignment is specified, force
680 the alignment to be the minimum valid atomic alignment. The
681 restriction on constant size avoids problems with variable-size
682 temporaries; if the size is variable, there's no issue with
683 atomic access. Also don't do this for a constant, since it isn't
684 necessary and can interfere with constant replacement. Finally,
685 do not do it for Out parameters since that creates an
686 size inconsistency with In parameters. */
695 #endif
697 /* Make a new type with the desired size and alignment, if needed. */
701 /* Make a volatile version of this object's type if we are to
702 make the object volatile. Note that 13.3(19) says that we
703 should treat other types of objects as volatile as well. */
713 /* Convert the expression to the type of the object except in the
714 case where the object's type is unconstrained or the object's type
715 is a padded record whose field is of self-referential size. In
716 the former case, converting will generate unnecessary evaluations
717 of the CONSTRUCTOR to compute the size and in the latter case, we
718 want to only copy the actual data. */
724 && (CONTAINS_PLACEHOLDER_P
728 /* See if this is a renaming. If this is a constant renaming,
729 treat it as a normal variable whose initial value is what
730 is being renamed. We cannot do this if the type is
731 unconstrained or class-wide.
733 Otherwise, if what we are renaming is a reference, we can simply
734 return a stabilized version of that reference, after forcing
735 any SAVE_EXPRs to be evaluated. But, if this is at global level,
736 we can only do this if we know no SAVE_EXPRs will be made.
737 Otherwise, make this into a constant pointer to the object we are
738 to rename. */
741 {
742 /* If the renamed object had padding, strip off the reference
743 to the inner object and reset our type. */
747 && (TYPE_IS_PADDING_P
749 {
752 }
759 ;
761 /* If this is a declaration or reference, we can just use that
762 declaration or reference as this entity. */
769 {
777 gnu_decl));
779 }
780 else
781 {
788 }
789 }
791 /* If this is an aliased object whose nominal subtype is unconstrained,
792 the object is a record that contains both the template and
793 the object. If there is an initializer, it will have already
794 been converted to the right type, but we need to create the
795 template if there is no initializer. */
798 /* Beware that padding might have been introduced
799 via maybe_pad_type above. */
802 == RECORD_TYPE
803 && TYPE_CONTAINS_TEMPLATE_P
806 {
807 tree template_field
812 gnu_expr
813 = gnat_build_constructor
815 tree_cons
819 NULL_TREE),
820 NULL_TREE));
821 }
823 /* If this is a pointer and it does not have an initializing
824 expression, initialize it to NULL, unless the obect is
825 imported. */
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_new_var
965 expand_expr_stmt
966 (build_binary_op
970 gnu_expr));
973 gnu_expr
974 = build_unary_op
982 }
984 /* Convert the expression to the type of the object except in the
985 case where the object's type is unconstrained or the object's type
986 is a padded record whose field is of self-referential size. In
987 the former case, converting will generate unnecessary evaluations
988 of the CONSTRUCTOR to compute the size and in the latter case, we
989 want to only copy the actual data. */
995 && (CONTAINS_PLACEHOLDER_P
999 /* If this name is external or there was a name specified, use it,
1000 unless this is a VMS exception object since this would conflict
1001 with the symbol we need to export in addition. Don't use the
1002 Interface_Name if there is an address clause (see CD30005). */
1004 &&
1007 ||
1016 /* If this is constant initialized to a static constant and the
1017 object has an aggregrate type, force it to be statically
1018 allocated. */
1036 /* If we have an address clause and we've made this indirect, it's
1037 not enough to merely mark the type as volatile since volatile
1038 references only conflict with other volatile references while this
1039 reference must conflict with all other references. So ensure that
1040 the dereferenced value has alias set 0. */
1050 STACK_CHECK_MAX_VAR_SIZE))))
1053 /* If this is a public constant or we're not optimizing and we're not
1054 making a VAR_DECL for it, make one just for export or debugger
1055 use. Likewise if the address is taken or if the object or type is
1056 aliased. */
1068 /* If this is declared in a block that contains an block with an
1069 exception handler, we must force this variable in memory to
1070 suppress an invalid optimization. */
1073 {
1076 }
1078 /* Back-annotate the Alignment of the object if not already in the
1079 tree. Likewise for Esize if the object is of a constant size.
1080 But if the "object" is actually a pointer to an object, the
1081 alignment and size are the same as teh type, so don't back-annotate
1082 the values for the pointer. */
1089 {
1094 gnu_back_size
1099 }
1100 }
1104 /* Return a TYPE_DECL for "void" that we previously made. */
1109 /* A special case, for the types Character and Wide_Character in
1110 Standard, we do not list all the literals. So if the literals
1111 are not specified, make this an unsigned type. */
1113 {
1116 }
1118 /* Normal case of non-character type, or non-Standard character type */
1119 {
1120 /* Here we have a list of enumeral constants in First_Literal.
1121 We make a CONST_DECL for each and build into GNU_LITERAL_LIST
1122 the list to be places into TYPE_FIELDS. Each node in the list
1123 is a TREE_LIST node whose TREE_VALUE is the literal name
1124 and whose TREE_PURPOSE is the value of the literal.
1126 Esize contains the number of bits needed to represent the enumeral
1127 type, Type_Low_Bound also points to the first literal and
1128 Type_High_Bound points to the last literal. */
1130 Entity_Id gnat_literal;
1135 else
1143 {
1145 gnu_type);
1146 tree gnu_literal
1153 }
1157 /* Note that the bounds are updated at the end of this function
1158 because to avoid an infinite recursion when we get the bounds of
1159 this type, since those bounds are objects of this type. */
1160 }
1166 /* For integer types, just make a signed type the appropriate number
1167 of bits. */
1172 /* For modular types, make the unsigned type of the proper number of
1173 bits and then set up the modulus, if required. */
1174 {
1176 tree gnu_modulus;
1182 /* Find the smallest mode at least ESIZE bits wide and make a class
1183 using that mode. */
1188 ;
1194 /* Get the modulus in this type. If it overflows, assume it is because
1195 it is equal to 2**Esize. Note that there is no overflow checking
1196 done on unsigned type, so we detect the overflow by looking for
1197 a modulus of zero, which is otherwise invalid. */
1201 {
1206 }
1208 /* If we have to set TYPE_PRECISION different from its natural value,
1209 make a subtype to do do. Likewise if there is a modulus and
1210 it is not one greater than TYPE_MAX_VALUE. */
1214 {
1231 }
1232 }
1241 /* For integral subtypes, we make a new INTEGER_TYPE. Note
1242 that we do not want to call build_range_type since we would
1243 like each subtype node to be distinct. This will be important
1244 when memory aliasing is implemented.
1246 The TREE_TYPE field of the INTEGER_TYPE we make points to the
1247 parent type; this fact is used by the arithmetic conversion
1248 functions.
1250 We elaborate the Ancestor_Subtype if it is not in the current
1251 unit and one of our bounds is non-static. We do this to ensure
1252 consistent naming in the case where several subtypes share the same
1253 bounds by always elaborating the first such subtype first, thus
1254 using its name. */
1266 {
1269 }
1277 gnat_entity,
1284 gnat_entity,
1288 /* One of the above calls might have caused us to be elaborated,
1289 so don't blow up if so. */
1291 {
1294 }
1299 /* This should be an unsigned type if the lower bound is constant
1300 and non-negative or if the base type is unsigned; a signed type
1301 otherwise. */
1311 /* If the type we are dealing with is to represent a packed array,
1312 we need to have the bits left justified on big-endian targets
1313 (see exp_packd.ads). We build a record with a bitfield of the
1314 appropriate size to achieve this. */
1316 {
1318 tree gnu_field;
1327 /* Don't notify the field as "addressable", since we won't be taking
1328 it's address and it would prevent create_field_decl from making a
1329 bitfield. */
1336 }
1341 /* If this is a VAX floating-point type, use an integer of the proper
1342 size. All the operations will be handled with ASM statements. */
1344 {
1349 sizetype));
1351 }
1353 /* The type of the Low and High bounds can be our type if this is
1354 a type from Standard, so set them at the end of the function. */
1362 {
1365 }
1367 {
1394 /* One of the above calls might have caused us to be elaborated,
1395 so don't blow up if so. */
1397 {
1400 }
1403 }
1406 /* Array and String Types and Subtypes
1408 Unconstrained array types are represented by E_Array_Type and
1409 constrained array types are represented by E_Array_Subtype. There
1410 are no actual objects of an unconstrained array type; all we have
1411 are pointers to that type.
1413 The following fields are defined on array types and subtypes:
1415 Component_Type Component type of the array.
1416 Number_Dimensions Number of dimensions (an int).
1417 First_Index Type of first index. */
1421 {
1427 int firstdim
1429 int nextdim
1435 tree gnu_max_size_unit;
1437 Entity_Id gnat_ind_subtype;
1438 Entity_Id gnat_ind_base_subtype;
1439 tree gnu_template_reference;
1440 tree tem;
1448 /* Make a node for the array. If we are not defining the array
1449 suppress expanding incomplete types and save the node as the type
1450 for GNAT_ENTITY. */
1453 {
1454 defer_incomplete_level++;
1458 debug_info_p);
1461 }
1463 /* Build the fat pointer type. Use a "void *" object instead of
1464 a pointer to the array type since we don't have the array type
1465 yet (it will reference the fat pointer via the bounds). */
1468 ptr_void_type_node,
1471 gnu_ptr_template,
1474 /* Make sure we can put this into a register. */
1478 /* Build a reference to the template from a PLACEHOLDER_EXPR that
1479 is the fat pointer. This will be used to access the individual
1480 fields once we build them. */
1484 gnu_template_reference
1488 /* Now create the GCC type for each index and add the fields for
1489 that index to the template. */
1491 gnat_ind_base_subtype
1497 {
1499 tree gnu_ind_subtype
1501 tree gnu_base_subtype
1503 tree gnu_base_min
1505 tree gnu_base_max
1509 /* Make the FIELD_DECLs for the minimum and maximum of this
1510 type and then make extractions of that field from the
1511 template. */
1515 gnu_ind_subtype,
1519 gnu_ind_subtype,
1524 /* We can't use build_component_ref here since the template
1525 type isn't complete yet. */
1532 /* Make a range type with the new ranges, but using
1533 the Ada subtype. Then we convert to sizetype. */
1539 /* Update the maximum size of the array, in elements. */
1540 gnu_max_size
1544 gnu_base_min)));
1548 }
1551 gnu_template_fields
1554 /* Install all the fields into the template. */
1558 /* Now make the array of arrays and update the pointer to the array
1559 in the fat pointer. Note that it is the first field. */
1563 /* Get and validate any specified Component_Size, but if Packed,
1564 ignore it since the front end will have taken care of it. */
1565 gnu_comp_size
1567 gnat_entity,
1575 /* If the component type is a RECORD_TYPE that has a self-referential
1576 size, use the maxium size. */
1582 {
1586 }
1592 /* If Component_Size is not already specified, annotate it with the
1593 size of the component. */
1603 gnu_max_size),
1607 {
1611 /* If the type below this an multi-array type, then this
1612 does not not have aliased components.
1614 ??? Otherwise, for now, we say that any component of aggregate
1615 type is addressable because the front end may take 'Reference
1616 of it. But we have to make it addressable if it must be passed
1617 by reference or it that is the default. */
1623 }
1625 /* If an alignment is specified, use it if valid. But ignore it for
1626 types that represent the unpacked base type for packed arrays. */
1629 {
1636 }
1642 /* The result type is an UNCONSTRAINED_ARRAY_TYPE that indicates the
1643 corresponding fat pointer. */
1650 /* If the maximum size doesn't overflow, use it. */
1663 debug_info_p);
1666 /* Create a record type for the object and its template and
1667 set the template at a negative offset. */
1679 /* Give the thin pointer type a name. */
1683 }
1689 /* This is the actual data type for array variables. Multidimensional
1690 arrays are implemented in the gnu tree as arrays of arrays. Note
1691 that for the moment arrays which have sparse enumeration subtypes as
1692 index components create sparse arrays, which is obviously space
1693 inefficient but so much easier to code for now.
1695 Also note that the subtype never refers to the unconstrained
1696 array type, which is somewhat at variance with Ada semantics.
1698 First check to see if this is simply a renaming of the array
1699 type. If so, the result is the array type. */
1704 else
1705 {
1708 int first_dim
1711 int next_dim
1713 Entity_Id gnat_ind_subtype;
1714 Entity_Id gnat_ind_base_subtype;
1719 tree gnu_max_size_unit;
1723 /* First create the gnu types for each index. Create types for
1724 debugging information to point to the index types if the
1725 are not integer types, have variable bounds, or are
1726 wider than sizetype. */
1729 gnat_ind_base_subtype
1735 {
1736 tree gnu_index_subtype
1738 tree gnu_min
1740 tree gnu_max
1742 tree gnu_base_subtype
1744 tree gnu_base_min
1746 tree gnu_base_max
1749 tree gnu_base_base_min
1751 tree gnu_base_base_max
1753 tree gnu_high;
1754 tree gnu_this_max;
1756 /* If the minimum and maximum values both overflow in
1757 SIZETYPE, but the difference in the original type
1758 does not overflow in SIZETYPE, ignore the overflow
1759 indications. */
1765 && (! TREE_OVERFLOW
1773 /* Similarly, if the range is null, use bounds of 1..0 for
1774 the sizetype bounds. */
1784 /* Now compute the size of this bound. We need to provide
1785 GCC with an upper bound to use but have to deal with the
1786 "superflat" case. There are three ways to do this. If we
1787 can prove that the array can never be superflat, we can
1788 just use the high bound of the index subtype. If we can
1789 prove that the low bound minus one can't overflow, we
1790 can do this as MAX (hb, lb - 1). Otherwise, we have to use
1791 the expression hb >= lb ? hb : lb - 1. */
1794 /* See if the base array type is already flat. If it is, we
1795 are probably compiling an ACVC test, but it will cause the
1796 code below to malfunction if we don't handle it specially. */
1804 /* If gnu_high is now an integer which overflowed, the array
1805 cannot be superflat. */
1812 else
1813 gnu_high
1814 = build_cond_expr
1822 /* Also compute the maximum size of the array. Here we
1823 see if any constraint on the index type of the base type
1824 can be used in the case of self-referential bound on
1825 the index type of the subtype. We look for a non-"infinite"
1826 and non-self-referential bound from any type involved and
1827 handle each bound separately. */
1852 gnu_this_max
1856 gnu_base_min)),
1857 size_zero_node);
1863 gnu_max_size
1877 }
1879 /* Then flatten: create the array of arrays. */
1883 /* One of the above calls might have caused us to be elaborated,
1884 so don't blow up if so. */
1886 {
1889 }
1891 /* Get and validate any specified Component_Size, but if Packed,
1892 ignore it since the front end will have taken care of it. */
1893 gnu_comp_size
1895 gnat_entity,
1900 /* If the component type is a RECORD_TYPE that has a self-referential
1901 size, use the maxium size. */
1907 {
1912 }
1926 {
1929 /* If the type below this an multi-array type, then this
1930 does not not have aliased components.
1932 ??? Otherwise, for now, we say that any component of aggregate
1933 type is addressable because the front end may take 'Reference
1934 of it. But we have to make it addressable if it must be passed
1935 by reference or it that is the default. */
1941 }
1943 /* If we are at file level and this is a multi-dimensional array, we
1944 need to make a variable corresponding to the stride of the
1945 inner dimensions. */
1947 {
1949 tree gnu_arr_type;
1955 {
1961 = elaborate_expression_1
1964 }
1965 }
1967 /* If we need to write out a record type giving the names of
1968 the bounds, do it now. */
1970 {
1973 tree gnu_field;
1979 {
1980 tree gnu_type_name
1987 integer_type_node,
1988 gnu_bound_rec_type,
1992 }
1995 }
2002 /* If our size depends on a placeholder and the maximum size doesn't
2003 overflow, use it. */
2010 {
2016 }
2018 /* Set our alias set to that of our base type. This gives all
2019 array subtypes the same alias set. */
2021 }
2023 /* If this is a packed type, make this type the same as the packed
2024 array type, but do some adjusting in the type first. */
2027 {
2028 Entity_Id gnat_index;
2029 tree gnu_inner_type;
2031 /* First finish the type we had been making so that we output
2032 debugging information for it */
2035 | (TYPE_QUAL_VOLATILE
2040 debug_info_p);
2044 /* Save it as our equivalent in case the call below elaborates
2045 this type again. */
2059 /* We need to point the type we just made to our index type so
2060 the actual bounds can be put into a template. */
2066 {
2068 {
2069 /* The TYPE_ACTUAL_BOUNDS field is also used for the modulus.
2070 If it is, we need to make another type. */
2072 {
2073 tree gnu_subtype;
2090 }
2093 }
2111 }
2112 }
2114 /* Abort if packed array with no packed array type field set. */
2121 /* Create the type for a string literal. */
2122 {
2123 Entity_Id gnat_full_type
2128 tree gnu_string_array_type
2130 tree gnu_string_index_type
2133 tree gnu_lower_bound
2138 tree gnu_upper_bound
2140 gnu_lower_bound,
2142 tree gnu_range_type
2145 tree gnu_index_type
2150 gnu_range_type);
2152 gnu_type
2154 gnu_index_type);
2155 }
2158 /* Record Types and Subtypes
2160 The following fields are defined on record types:
2162 Has_Discriminants True if the record has discriminants
2163 First_Discriminant Points to head of list of discriminants
2164 First_Entity Points to head of list of fields
2165 Is_Tagged_Type True if the record is tagged
2167 Implementation of Ada records and discriminated records:
2169 A record type definition is transformed into the equivalent of a C
2170 struct definition. The fields that are the discriminants which are
2171 found in the Full_Type_Declaration node and the elements of the
2172 Component_List found in the Record_Type_Definition node. The
2173 Component_List can be a recursive structure since each Variant of
2174 the Variant_Part of the Component_List has a Component_List.
2176 Processing of a record type definition comprises starting the list of
2177 field declarations here from the discriminants and the calling the
2178 function components_to_record to add the rest of the fields from the
2179 component list and return the gnu type node. The function
2180 components_to_record will call itself recursively as it traverses
2181 the tree. */
2185 {
2186 gnu_type
2187 = build_complex_type
2188 (get_unpadded_type
2191 (Component_List
2192 (Type_Definition
2196 }
2198 {
2201 Entity_Id gnat_field;
2202 tree gnu_field;
2204 tree gnu_get_parent;
2211 int is_extension
2215 /* See if all fields have a rep clause. Stop when we find one
2216 that doesn't. */
2225 /* If this is a record extension, go a level further to find the
2226 record definition. Also, verify we have a Parent_Subtype. */
2228 {
2235 }
2237 /* Make a node for the record. If we are not defining the record,
2238 suppress expanding incomplete types and save the node as the type
2239 for GNAT_ENTITY. We use the same RECORD_TYPE as for a dummy type
2240 and reset TYPE_DUMMY_P to show it's no longer a dummy.
2242 It is very tempting to delay resetting this bit until we are done
2243 with completing the type, e.g. to let possible intermediate
2244 elaboration of access types designating the record know it is not
2245 complete and arrange for update_pointer_to to fix things up later.
2247 It would be wrong, however, because dummy types are expected only
2248 to be created for Ada incomplete or private types, which is not
2249 what we have here. Doing so would make other parts of gigi think
2250 we are dealing with a really incomplete or private type, and have
2251 nasty side effects, typically on the generation of the associated
2252 debugging information. */
2263 {
2264 defer_incomplete_level++;
2269 debug_info_p);
2272 }
2274 /* If both a size and rep clause was specified, put the size in
2275 the record type now so that it can get the proper mode. */
2279 /* Always set the alignment here so that it can be used to
2280 set the mode, if it is making the alignment stricter. If
2281 it is invalid, it will be checked again below. If this is to
2282 be Atomic, choose a default alignment of a word unless we know
2283 the size and it's smaller. */
2292 /* If we have a Parent_Subtype, make a field for the parent. If
2293 this record has rep clauses, force the position to zero. */
2295 {
2296 tree gnu_parent;
2298 /* A major complexity here is that the parent subtype will
2299 reference our discriminants. But those must reference
2300 the parent component of this record. So here we will
2301 initialize each of those components to a COMPONENT_REF.
2302 The first operand of that COMPONENT_REF is another
2303 COMPONENT_REF which will be filled in below, once
2304 the parent type can be safely built. */
2309 NULL_TREE));
2316 save_gnu_tree
2320 gnu_get_parent,
2328 gnu_field_list
2338 }
2340 /* Add the fields for the discriminants into the record. */
2346 {
2347 /* If this is a record extension and this discriminant
2348 is the renaming of another discriminant, we've already
2349 handled the discriminant above. */
2354 gnu_field
2357 /* Make an expression using a PLACEHOLDER_EXPR from the
2358 FIELD_DECL node just created and link that with the
2359 corresponding GNAT defining identifier. Then add to the
2360 list of fields. */
2365 gnu_field),
2370 }
2372 /* Put the discriminants into the record (backwards), so we can
2373 know the appropriate discriminant to use for the names of the
2374 variants. */
2377 /* Add the listed fields into the record and finish up. */
2385 /* If this is an extension type, reset the tree for any
2386 inherited discriminants. Also remove the PLACEHOLDER_EXPR
2387 for non-inherited discriminants. */
2393 {
2397 else
2398 {
2402 }
2403 }
2405 /* If it is a tagged record force the type to BLKmode to insure
2406 that these objects will always be placed in memory. Do the
2407 same thing for limited record types. */
2411 /* If this is a derived type, we must make the alias set of this type
2412 the same as that of the type we are derived from. We assume here
2413 that the other type is already frozen. */
2419 /* Fill in locations of fields. */
2422 /* If there are any entities in the chain corresponding to
2423 components that we did not elaborate, ensure we elaborate their
2424 types if they are Itypes. */
2432 }
2436 /* If an equivalent type is present, that is what we should use.
2437 Otherwise, fall through to handle this like a record subtype
2438 since it may have constraints. */
2441 {
2446 }
2448 /* ... fall through ... */
2452 /* If Cloned_Subtype is Present it means this record subtype has
2453 identical layout to that type or subtype and we should use
2454 that GCC type for this one. The front end guarantees that
2455 the component list is shared. */
2457 {
2461 }
2463 /* Otherwise, first ensure the base type is elaborated. Then, if we are
2464 changing the type, make a new type with each field having the
2465 type of the field in the new subtype but having the position
2466 computed by transforming every discriminant reference according
2467 to the constraints. We don't see any difference between
2468 private and nonprivate type here since derivations from types should
2469 have been deferred until the completion of the private type. */
2470 else
2471 {
2473 tree gnu_base_type;
2474 tree gnu_orig_type;
2479 /* Get the base type initially for its alignment and sizes. But
2480 if it is a padded type, we do all the other work with the
2481 unpadded type. */
2490 {
2493 }
2495 /* When the type has discriminants, and these discriminants
2496 affect the shape of what it built, factor them in.
2498 If we are making a subtype of an Unchecked_Union (must be an
2499 Itype), just return the type.
2501 We can't just use Is_Constrained because private subtypes without
2502 discriminants of full types with discriminants with default
2503 expressions are Is_Constrained but aren't constrained! */
2511 {
2512 Entity_Id gnat_field;
2513 Entity_Id gnat_root_type;
2515 tree gnu_pos_list
2518 BIGGEST_ALIGNMENT);
2519 tree gnu_subst_list
2521 definition);
2522 tree gnu_temp;
2524 /* If this is a derived type, we may be seeing fields from any
2525 original records, so add those positions and discriminant
2526 substitutions to our lists. */
2530 {
2531 gnu_pos_list
2532 = compute_field_positions
2535 BIGGEST_ALIGNMENT);
2538 gnu_subst_list
2541 }
2553 {
2554 tree gnu_old_field
2555 = gnat_to_gnu_entity
2557 tree gnu_offset
2559 gnu_pos_list));
2562 tree gnu_field_type
2566 unsigned int offset_align
2569 tree gnu_field;
2571 /* If there was a component clause, the field types must be
2572 the same for the type and subtype, so copy the data from
2573 the old field to avoid recomputation here. */
2576 {
2579 }
2581 /* If this was a bitfield, get the size from the old field.
2582 Also ensure the type can be placed into a bitfield. */
2584 {
2590 }
2599 /* If the size is now a constant, we can set it as the
2600 size of the field when we make it. Otherwise, we need
2601 to deal with it specially. */
2605 gnu_field
2606 = create_field_decl
2612 {
2621 bitsize_unit_node));
2623 }
2638 }
2642 /* Now set the size, alignment and alias set of the new type to
2643 match that of the old one, doing any substitutions, as
2644 above. */
2676 /* Recompute the mode of this record type now that we know its
2677 actual size. */
2680 /* Fill in locations of fields. */
2682 }
2684 /* If we've made a new type, record it and make an XVS type to show
2685 what this is a subtype of. Some debuggers require the XVS
2686 type to be output first, so do it in that order. */
2688 {
2690 {
2701 integer_type_node,
2702 gnu_subtype_marker,
2706 }
2712 gnu_type));
2716 }
2718 /* Otherwise, go down all the components in the new type and
2719 make them equivalent to those in the base type. */
2720 else
2727 get_gnu_tree
2729 }
2733 /* If we are not defining this entity, and we have incomplete
2734 entities being processed above us, make a dummy type and
2735 fill it in later. */
2737 {
2741 gnu_type
2742 = build_pointer_type
2746 debug_info_p);
2755 }
2757 /* ... fall through ... */
2764 {
2766 Entity_Id gnat_desig_full
2768 Incomplete_Or_Private_Kind))
2770 /* We want to know if we'll be seeing the freeze node for any
2771 incomplete type we may be pointing to. */
2772 int in_main_unit
2788 {
2790 {
2794 }
2796 Incomplete_Or_Private_Kind))
2798 }
2803 /* If either the designated type or its full view is an
2804 unconstrained array subtype, replace it with the type it's a
2805 subtype of. This avoids problems with multiple copies of
2806 unconstrained array types. */
2815 /* If the designated type is a subtype of an incomplete record type,
2816 use the parent type to avoid order of elaboration issues. This
2817 can lose some code efficiency, but there is no alternative. */
2823 /* If we are pointing to an incomplete type whose completion is an
2824 unconstrained array, make a fat pointer type instead of a pointer
2825 to VOID. The two types in our fields will be pointers to VOID and
2826 will be replaced in update_pointer_to. Similiarly, if the type
2827 itself is a dummy type or an unconstrained array. Also make
2828 a dummy TYPE_OBJECT_RECORD_TYPE in case we have any thin
2829 pointers to it. */
2850 {
2851 tree gnu_old
2855 tree fields;
2857 /* Show the dummy we get will be a fat pointer. */
2860 /* If the call above got something that has a pointer, that
2861 pointer is our type. This could have happened either
2862 because the type was elaborated or because somebody
2863 else executed the code below. */
2866 {
2872 fields
2874 create_field_decl
2879 ptr_void_type_node,
2882 /* Make sure we can place this into a register. */
2893 }
2894 }
2896 /* If we already know what the full type is, use it. */
2901 /* Get the type of the thing we are to point to and build a pointer
2902 to it. If it is a reference to an incomplete or private type with a
2903 full view that is a record, make a dummy type node and get the
2904 actual type later when we have verified it is safe. */
2910 {
2913 }
2915 /* Likewise if we are pointing to a record or array and we are to defer
2916 elaborating incomplete types. We do this since this access type
2917 may be the full view of some private type. Note that the
2918 unconstrained array case is handled above. */
2926 {
2929 }
2931 {
2932 gnu_type
2934 p_mode,
2937 }
2938 else
2941 /* It is possible that the above call to gnat_to_gnu_type resolved our
2942 type. If so, just return it. */
2944 {
2947 }
2949 /* If we have a GCC type for the designated type, possibly modify it
2950 if we are pointing only to constant objects and then make a pointer
2951 to it. Don't do this for unconstrained arrays. */
2953 {
2956 {
2957 gnu_desig_type
2958 = build_qualified_type
2962 /* Some extra processing is required if we are building a
2963 pointer to an incomplete type (in the GCC sense). We might
2964 have such a type if we just made a dummy, or directly out
2965 of the call to gnat_to_gnu_type above if we are processing
2966 an access type for a record component designating the
2967 record type itself. */
2969 {
2970 /* We must ensure that the pointer to variant we make will
2971 be processed by update_pointer_to when the initial type
2972 is completed. Pretend we made a dummy and let further
2973 processing act as usual. */
2976 /* We must ensure that update_pointer_to will not retrieve
2977 the dummy variant when building a properly qualified
2978 version of the complete type. We take advantage of the
2979 fact that get_qualified_type is requiring TYPE_NAMEs to
2980 match to influence build_qualified_type and then also
2981 update_pointer_to here. */
2984 }
2985 }
2987 gnu_type
2990 }
2992 /* If we are not defining this object and we made a dummy pointer,
2993 save our current definition, evaluate the actual type, and replace
2994 the tentative type we made with the actual one. If we are to defer
2995 actually looking up the actual type, make an entry in the
2996 deferred list. */
2999 {
3000 tree gnu_old_type
3006 gnu_type
3007 = build_pointer_type
3008 (TYPE_OBJECT_RECORD_TYPE
3013 debug_info_p);
3018 {
3021 /* Note that the call to gnat_to_gnu_type here might have
3022 updated gnu_old_type directly, in which case it is not a
3023 dummy type any more when we get into update_pointer_to.
3025 This may happen for instance when the designated type is a
3026 record type, because their elaboration starts with an
3027 initial node from make_dummy_type, which may yield the same
3028 node as the one we got.
3030 Besides, variants of this non-dummy type might have been
3031 created along the way. update_pointer_to is expected to
3032 properly take care of those situations. */
3033 }
3034 else
3035 {
3043 }
3044 }
3045 }
3051 else
3052 /* The runtime representation is the equivalent type. */
3066 /* We treat this as identical to its base type; any constraint is
3067 meaningful only to the front end.
3069 The designated type must be elaborated as well, if it does
3070 not have its own freeze node. Designated (sub)types created
3071 for constrained components of records with discriminants are
3072 not frozen by the front end and thus not elaborated by gigi,
3073 because their use may appear before the base type is frozen,
3074 and because it is not clear that they are needed anywhere in
3075 Gigi. With the current model, there is no correct place where
3076 they could be elaborated. */
3083 {
3084 /* If we are not defining this entity, and we have incomplete
3085 entities being processed above us, make a dummy type and
3086 elaborate it later. */
3088 {
3091 tree gnu_ptr_type
3092 = build_pointer_type
3099 }
3100 else if
3102 Incomplete_Or_Private_Kind))
3103 { ;}
3104 else
3107 }
3112 /* Subprogram Entities
3114 The following access functions are defined for subprograms (functions
3115 or procedures):
3117 First_Formal The first formal parameter.
3118 Is_Imported Indicates that the subprogram has appeared in
3119 an INTERFACE or IMPORT pragma. For now we
3120 assume that the external language is C.
3121 Is_Inlined True if the subprogram is to be inlined.
3123 In addition for function subprograms we have:
3125 Etype Return type of the function.
3127 Each parameter is first checked by calling must_pass_by_ref on its
3128 type to determine if it is passed by reference. For parameters which
3129 are copied in, if they are Ada IN OUT or OUT parameters, their return
3130 value becomes part of a record which becomes the return type of the
3131 function (C function - note that this applies only to Ada procedures
3132 so there is no Ada return type). Additional code to store back the
3133 parameters will be generated on the caller side. This transformation
3134 is done here, not in the front-end.
3136 The intended result of the transformation can be seen from the
3137 equivalent source rewritings that follow:
3139 struct temp {int a,b};
3140 procedure P (A,B: IN OUT ...) is temp P (int A,B) {
3141 .. ..
3142 end P; return {A,B};
3143 }
3144 procedure call
3146 {
3147 temp t;
3148 P(X,Y); t = P(X,Y);
3149 X = t.a , Y = t.b;
3150 }
3152 For subprogram types we need to perform mainly the same conversions to
3153 GCC form that are needed for procedures and function declarations. The
3154 only difference is that at the end, we make a type declaration instead
3155 of a function declaration. */
3160 {
3161 /* The first GCC parameter declaration (a PARM_DECL node). The
3162 PARM_DECL nodes are chained through the TREE_CHAIN field, so this
3163 actually is the head of this parameter list. */
3165 /* The type returned by a function. If the subprogram is a procedure
3166 this type should be void_type_node. */
3168 /* List of fields in return type of procedure with copy in copy out
3169 parameters. */
3171 /* Non-null for subprograms containing parameters passed by copy in
3172 copy out (Ada IN OUT or OUT parameters not passed by reference),
3173 in which case it is the list of nodes used to specify the values of
3174 the in out/out parameters that are returned as a record upon
3175 procedure return. The TREE_PURPOSE of an element of this list is
3176 a field of the record and the TREE_VALUE is the PARM_DECL
3177 corresponding to that field. This list will be saved in the
3178 TYPE_CI_CO_LIST field of the FUNCTION_TYPE node we create. */
3180 Entity_Id gnat_param;
3183 int extern_flag
3194 /* A parameter may refer to this type, so defer completion
3195 of any incomplete types. */
3198 /* If the subprogram has an alias, it is probably inherited, so
3199 we can use the original one. If the original "subprogram"
3200 is actually an enumeration literal, it may be the first use
3201 of its type, so we must elaborate that type now. */
3203 {
3210 /* Elaborate any Itypes in the parameters of this entity. */
3218 }
3223 /* If this function returns by reference, make the actual
3224 return type of this function the pointer and mark the decl. */
3226 {
3229 }
3231 /* If the Mechanism is By_Reference, ensure the return type uses
3232 the machine's by-reference mechanism, which may not the same
3233 as above (e.g., it might be by passing a fake parameter). */
3236 {
3239 }
3241 /* If we are supposed to return an unconstrained array,
3242 actually return a fat pointer and make a note of that. Return
3243 a pointer to an unconstrained record of variable size. */
3245 {
3248 }
3250 /* If the type requires a transient scope, the result is allocated
3251 on the secondary stack, so the result type of the function is
3252 just a pointer. */
3254 {
3257 }
3259 /* If the type is a padded type and the underlying type would not
3260 be passed by reference or this function has a foreign convention,
3261 return the underlying type. */
3269 /* Look at all our parameters and get the type of
3270 each. While doing this, build a copy-out structure if
3271 we need one. */
3273 /* If the return type has a size that overflows, we cannot have
3274 a function that returns that type. This usage doesn't make
3275 sense anyway, so give an error here. */
3278 {
3280 gnat_entity);
3286 }
3291 {
3301 /* See if a Mechanism was supplied that forced this
3302 parameter to be passed one way or another. */
3306 ;
3314 {
3320 else
3322 }
3323 else
3326 /* If this is either a foreign function or if the
3327 underlying type won't be passed by refererence, strip off
3328 possible padding type. */
3336 /* If this is an IN parameter it is read-only, so make a variant
3337 of the type that is read-only.
3339 ??? However, if this is an unconstrained array, that type can
3340 be very complex. So skip it for now. Likewise for any other
3341 self-referential type. */
3346 gnu_param_type
3351 /* For foreign conventions, pass arrays as a pointer to the
3352 underlying type. First check for unconstrained array and get
3353 the underlying array. Then get the component type and build
3354 a pointer to it. */
3357 gnu_param_type
3362 gnu_param_type
3363 = build_pointer_type
3366 gnat_entity));
3369 && ! req_by_copy
3371 {
3372 /* Strip off any multi-dimensional entries, then strip
3373 off the last array to get the component type. */
3382 gnu_param_type
3388 }
3390 /* Fat pointers are passed as thin pointers for foreign
3391 conventions. */
3394 gnu_param_type
3398 /* If we must pass or were requested to pass by reference, do so.
3399 If we were requested to pass by copy, do so.
3400 Otherwise, for foreign conventions, pass all in out parameters
3401 or aggregates by reference. For COBOL and Fortran, pass
3402 all integer and FP types that way too. For Convention Ada,
3403 use the standard Ada default. */
3405 || (! req_by_copy
3415 /* For convention Ada, see if we pass by reference
3416 by default. */
3419 {
3422 }
3430 /* If this is an OUT parameter that isn't passed by reference
3431 and isn't a pointer or aggregate, we don't make a PARM_DECL
3432 for it. Instead, it will be a VAR_DECL created when we process
3433 the procedure. For the special parameter of Valued_Procedure,
3434 never pass it in.
3436 An exception is made to cover the RM-6.4.1 rule requiring "by
3437 copy" out parameters with discriminants or implicit initial
3438 values to be handled like in out parameters. These type are
3439 normally built as aggregates, and hence passed by reference,
3440 except for some packed arrays which end up encoded in special
3441 integer types.
3443 The exception we need to make is then for packed arrays of
3444 records with discriminants or implicit initial values. We have
3445 no light/easy way to check for the latter case, so we merely
3446 check for packed arrays of records. This may lead to useless
3447 copy-in operations, but in very rare cases only, as these would
3448 be exceptions in a set of already exceptional situations. */
3451 || (! by_descr_p
3459 else
3460 {
3462 gnu_param
3463 = create_param_decl
3465 by_ref_p || by_component_ptr_p
3477 /* If a parameter is a pointer, this function may modify
3478 memory through it and thus shouldn't be considered
3479 a pure function. Also, the memory may be modified
3480 between two calls, so they can't be CSE'ed. The latter
3481 case also handles by-ref parameters. */
3485 }
3488 {
3490 {
3497 }
3505 gnu_return_list);
3506 }
3507 }
3509 /* Do not compute record for out parameters if subprogram is
3510 stubbed since structures are incomplete for the back-end. */
3516 /* If we have a CICO list but it has only one entry, we convert
3517 this function into a function that simply returns that one
3518 object. */
3522 #ifdef _WIN32
3524 {
3534 }
3535 #endif
3537 /* Both lists ware built in reverse. */
3541 gnu_type
3544 returns_by_ref,
3547 /* ??? For now, don't consider nested functions pure. */
3551 /* A subprogram (something that doesn't return anything) shouldn't
3552 be considered Pure since there would be no reason for such a
3553 subprogram. Note that procedures with Out (or In Out) parameters
3554 have already been converted into a function with a return type. */
3558 gnu_type
3566 /* If there was no specified Interface_Name and the external and
3567 internal names of the subprogram are the same, only use the
3568 internal name to allow disambiguation of nested subprograms. */
3572 /* If we are defining the subprogram and it has an Address clause
3573 we must get the address expression from the saved GCC tree for the
3574 subprogram if it has a Freeze_Node. Otherwise, we elaborate
3575 the address expression here since the front-end has guaranteed
3576 in that case that the elaboration has no effects. If there is
3577 an Address clause and we are not defining the object, just
3578 make it a constant. */
3580 {
3584 gnu_address
3595 gnu_decl
3600 }
3605 debug_info_p);
3606 else
3607 {
3614 }
3615 }
3626 /* If this type does not have a full view in the unit we are
3627 compiling, then just get the type from its Etype. */
3629 {
3630 /* If this is an incomplete type with no full view, it must
3631 be a Taft Amendement type, so just return a dummy type. */
3638 else
3639 {
3643 }
3646 }
3648 /* Otherwise, if we are not defining the type now, get the
3649 type from the full view. But always get the type from the full
3650 view for define on use types, since otherwise we won't see them! */
3657 {
3662 }
3664 /* For incomplete types, make a dummy type entry which will be
3665 replaced later. */
3668 /* Save this type as the full declaration's type so we can do any needed
3669 updates when we see it. */
3673 debug_info_p);
3677 /* Simple class_wide types are always viewed as their root_type
3678 by Gigi unless an Equivalent_Type is specified. */
3682 else
3694 else
3706 /* Nothing at all to do here, so just return an ERROR_MARK and claim
3707 we've already saved it, so we don't try to. */
3714 }
3716 /* If we had a case where we evaluated another type and it might have
3717 defined this one, handle it here. */
3719 {
3722 }
3724 /* If we are processing a type and there is either no decl for it or
3725 we just made one, do some common processing for the type, such as
3726 handling alignment and possible padding. */
3729 {
3737 /* ??? Don't set the size for a String_Literal since it is either
3738 confirming or we don't handle it properly (if the low bound is
3739 non-constant). */
3744 /* If a size was specified, see if we can make a new type of that size
3745 by rearranging the type, for example from a fat to a thin pointer. */
3747 {
3748 gnu_type
3755 }
3757 /* If the alignment hasn't already been processed and this is
3758 not an unconstrained array, see if an alignment is specified.
3759 If not, we pick a default alignment for atomic objects. */
3761 ;
3775 /* See if we need to pad the type. If we did, and made a record,
3776 the name of the new type may be changed. So get it back for
3777 us when we make the new TYPE_DECL below. */
3782 {
3786 }
3790 /* If we are at global level, GCC will have applied variable_size to
3791 the type, but that won't have done anything. So, if it's not
3792 a constant or self-referential, call elaborate_expression_1 to
3793 make a variable for the size rather than calculating it each time.
3794 Handle both the RM size and the actual size. */
3799 {
3803 {
3810 }
3811 else
3812 {
3819 /* ??? For now, store the size as a multiple of the alignment
3820 in bytes so that we can see the alignment from the tree. */
3822 = build_binary_op
3824 elaborate_expression_1
3840 }
3841 }
3843 /* If this is a record type or subtype, call elaborate_expression_1 on
3844 any field position. Do this for both global and local types.
3845 Skip any fields that we haven't made trees for to avoid problems with
3846 class wide types. */
3851 {
3854 /* ??? Unfortunately, GCC needs to be able to prove the
3855 alignment of this offset and if it's a variable, it can't.
3856 In GCC 3.4, we'll use DECL_OFFSET_ALIGN in some way, but
3857 right now, we have to put in an explicit multiply and
3858 divide by that value. */
3861 = build_binary_op
3863 elaborate_expression_1
3872 }
3876 | (TYPE_QUAL_VOLATILE
3886 {
3890 debug_info_p);
3891 }
3892 else
3894 }
3897 {
3900 /* Back-annotate the Alignment of the type if not already in the
3901 tree. Likewise for sizes. */
3907 {
3908 /* If the size is self-referential, we annotate the maximum
3909 value of that size. */
3918 {
3919 /* In this mode the tag and the parent components are not
3920 generated by the front-end, so the sizes must be adjusted
3921 explicitly now. */
3927 {
3928 size_offset
3932 }
3933 else
3941 }
3942 }
3946 }
3955 /* If this decl is really indirect, adjust it. */
3959 /* If we haven't already, associate the ..._DECL node that we just made with
3960 the input GNAT entity node. */
3964 /* If this is an enumeral or floating-point type, we were not able to set
3965 the bounds since they refer to the type. These bounds are always static.
3967 For enumeration types, also write debugging information and declare the
3968 enumeration literal table, if needed. */
3972 {
3975 /* If this is a padded type, we need to use the underlying type. */
3980 /* If this is a floating point type and we haven't set a floating
3981 point type yet, use this in the evaluation of the bounds. */
3991 {
3994 /* Since this has both a typedef and a tag, avoid outputting
3995 the name twice. */
3998 }
3999 }
4001 /* If we deferred processing of incomplete types, re-enable it. If there
4002 were no other disables and we have some to process, do so. */
4005 {
4011 {
4018 }
4019 }
4021 /* If we are not defining this type, see if it's in the incomplete list.
4022 If so, handle that list entry now. */
4024 {
4029 {
4033 }
4034 }
4037 force_global--;
4046 }
4047 \f
4048 /* Given GNAT_ENTITY, elaborate all expressions that are required to
4049 be elaborated at the point of its definition, but do nothing else. */
4051 void
4053 {
4055 {
4062 {
4066 /* ??? Tests for avoiding static constaint error expression
4067 is needed until the front stops generating bogus conversions
4068 on bounds of real types. */
4077 }
4080 {
4084 /* If this is a record extension, go a level further to find the
4085 record definition. */
4088 }
4098 {
4099 Node_Id gnat_discriminant_expr;
4100 Entity_Id gnat_field;
4103 gnat_discriminant_expr
4108 /* ??? For now, ignore access discriminants. */
4111 gnat_entity,
4113 }
4116 }
4117 }
4118 \f
4119 /* Mark GNAT_ENTITY as going out of scope at this point. Recursively mark
4120 any entities on its entity chain similarly. */
4122 void
4124 {
4125 Entity_Id gnat_sub_entity;
4128 /* If this has an entity list, process all in the list. */
4145 /* Now clear this if it has been defined, but only do so if it isn't
4146 a subprogram or parameter. We could refine this, but it isn't
4147 worth it. If this is statically allocated, it is supposed to
4148 hang around out of cope. */
4151 {
4154 }
4155 }
4156 \f
4157 /* Set the alias set of GNU_NEW_TYPE to be that of GNU_OLD_TYPE. If this
4158 is a multi-dimensional array type, do this recursively. */
4160 static void
4162 {
4166 {
4167 /* We need to be careful here in case GNU_OLD_TYPE is an unconstrained
4168 array. In that case, it doesn't have the same shape as GNU_NEW_TYPE,
4169 so we need to go down to what does. */
4171 gnu_old_type
4175 }
4179 }
4180 \f
4181 /* Return a TREE_LIST describing the substitutions needed to reflect
4182 discriminant substitutions from GNAT_SUBTYPE to GNAT_TYPE and add
4183 them to GNU_LIST. If GNAT_TYPE is not specified, use the base type
4184 of GNAT_SUBTYPE. The substitions can be in any order. TREE_PURPOSE
4185 gives the tree for the discriminant and TREE_VALUES is the replacement
4186 value. They are in the form of operands to substitute_in_expr.
4187 DEFINITION is as in gnat_to_gnu_entity. */
4189 static tree
4191 Entity_Id gnat_type,
4192 tree gnu_list,
4194 {
4195 Entity_Id gnat_discrim;
4196 Node_Id gnat_value;
4207 /* Ignore access discriminants. */
4210 elaborate_expression
4214 gnu_list);
4217 }
4218 \f
4219 /* For the following two functions: for each GNAT entity, the GCC
4220 tree node used as a dummy for that entity, if any. */
4224 /* Initialize the above table. */
4226 void
4228 {
4229 Node_Id gnat_node;
4237 }
4239 /* Make a dummy type corresponding to GNAT_TYPE. */
4241 tree
4243 {
4244 Entity_Id gnat_underlying;
4245 tree gnu_type;
4247 /* Find a full type for GNAT_TYPE, taking into account any class wide
4248 types. */
4258 ;
4260 /* If it there already a dummy type, use that one. Else make one. */
4264 /* If this is a record, make this a RECORD_TYPE or UNION_TYPE; else make
4265 it a VOID_TYPE. */
4269 else
4281 }
4282 \f
4283 /* Return 1 if the size represented by GNU_SIZE can be handled by an
4284 allocation. If STATIC_P is non-zero, consider only what can be
4285 done with a static allocation. */
4287 static int
4289 {
4290 HOST_WIDE_INT our_size;
4292 /* If this is not a static allocation, the only case we want to forbid
4293 is an overflowing size. That will be converted into a raise a
4294 Storage_Error. */
4299 /* Otherwise, we need to deal with both variable sizes and constant
4300 sizes that won't fit in a host int. We use int instead of HOST_WIDE_INT
4301 since assemblers may not like very large sizes. */
4307 }
4308 \f
4309 /* Return a list of attributes for GNAT_ENTITY, if any. */
4313 {
4315 Node_Id gnat_temp;
4320 {
4330 {
4332 (gnat_to_gnu
4339 (gnat_to_gnu
4340 (Expression
4343 }
4346 {
4365 }
4372 attr->error_point
4376 }
4379 }
4380 \f
4381 /* Get the unpadded version of a GNAT type. */
4383 tree
4385 {
4392 }
4393 \f
4394 /* Called when we need to protect a variable object using a save_expr. */
4396 tree
4398 {
4404 /* If we will be generating code, make sure we are at the proper
4405 line number. */
4412 else
4414 }
4415 \f
4416 /* Given a GNAT tree GNAT_EXPR, for an expression which is a value within a
4417 type definition (either a bound or a discriminant value) for GNAT_ENTITY,
4418 return the GCC tree to use for that expression. GNU_NAME is the
4419 qualification to use if an external name is appropriate and DEFINITION is
4420 nonzero if this is a definition of GNAT_ENTITY. If NEED_VALUE is nonzero,
4421 we need a result. Otherwise, we are just elaborating this for
4422 side-effects. If NEED_DEBUG is nonzero we need the symbol for debugging
4423 purposes even if it isn't needed for code generation. */
4425 static tree
4427 Entity_Id gnat_entity,
4428 tree gnu_name,
4432 {
4433 tree gnu_expr;
4435 /* If we already elaborated this expression (e.g., it was involved
4436 in the definition of a private type), use the old value. */
4440 /* If we don't need a value and this is static or a discriment, we
4441 don't need to do anything. */
4448 /* Otherwise, convert this tree to its GCC equivalant. */
4449 gnu_expr
4453 /* Save the expression in case we try to elaborate this entity again.
4454 Since this is not a DECL, don't check it. If this is a constant,
4455 don't save it since GNAT_EXPR might be used more than once. Also,
4456 don't save if it's a discriminant. */
4461 }
4463 /* Similar, but take a GNU expression. */
4465 static tree
4467 Entity_Id gnat_entity,
4468 tree gnu_expr,
4469 tree gnu_name,
4472 {
4474 /* Strip any conversions to see if the expression is a readonly variable.
4475 ??? This really should remain readonly, but we have to think about
4476 the typing of the tree here. */
4481 /* In most cases, we won't see a naked FIELD_DECL here because a
4482 discriminant reference will have been replaced with a COMPONENT_REF
4483 when the type is being elaborated. However, there are some cases
4484 involving child types where we will. So convert it to a COMPONENT_REF
4485 here. We have to hope it will be at the highest level of the
4486 expression in these cases. */
4490 gnu_expr);
4492 /* If GNU_EXPR is neither a placeholder nor a constant, nor a variable
4493 that is a constant, make a variable that is initialized to contain the
4494 bound when the package containing the definition is elaborated. If
4495 this entity is defined at top level and a bound or discriminant value
4496 isn't a constant or a reference to a discriminant, replace the bound
4497 by the variable; otherwise use a SAVE_EXPR if needed. Note that we
4498 rely here on the fact that an expression cannot contain both the
4499 discriminant and some other variable. */
4506 /* If this is a static expression or contains a discriminant, we don't
4507 need the variable for debugging (and can't elaborate anyway if a
4508 discriminant). */
4514 /* Now create the variable if we need it. */
4516 {
4518 gnu_decl
4523 }
4525 /* We only need to use this variable if we are in global context since GCC
4526 can do the right thing in the local case. */
4531 else
4533 }
4534 \f
4535 /* Create a record type that contains a field of TYPE with a starting bit
4536 position so that it is aligned to ALIGN bits and is SIZE bytes long. */
4538 tree
4540 {
4545 place));
4554 /* The bit position is obtained by "and"ing the alignment minus 1
4555 with the two's complement of the address and multiplying
4556 by the number of bits per unit. Do all this in sizetype. */
4562 size_addr_place),
4565 bitsize_unit_node);
4576 bitsize_unit_node),
4582 }
4583 \f
4584 /* TYPE is a RECORD_TYPE, UNION_TYPE, or QUAL_UNION_TYPE, with BLKmode that's
4585 being used as the field type of a packed record. See if we can rewrite it
4586 as a record that has a non-BLKmode type, which we can pack tighter. If so,
4587 return the new type. If not, return the original type. */
4589 static tree
4591 {
4594 tree old_field;
4596 /* Copy the name and flags from the old type to that of the new and set
4597 the alignment to try for an integral type. For QUAL_UNION_TYPE,
4598 also copy the size. */
4605 {
4608 }
4614 /* Now copy the fields, keeping the position and size. */
4617 {
4619 tree new_field;
4644 }
4649 }
4650 \f
4651 /* Ensure that TYPE has SIZE and ALIGN. Make and return a new padded type
4652 if needed. We have already verified that SIZE and TYPE are large enough.
4654 GNAT_ENTITY and NAME_TRAILER are used to name the resulting record and
4655 to issue a warning.
4657 IS_USER_TYPE is nonzero if we must be sure we complete the original type.
4659 DEFINITION is nonzero if this type is being defined.
4661 SAME_RM_SIZE is nonzero if the RM_Size of the resulting type is to be
4662 set to its TYPE_SIZE; otherwise, it's set to the RM_Size of the original
4663 type. */
4665 static tree
4667 tree size,
4669 Entity_Id gnat_entity,
4674 {
4676 tree record;
4677 tree field;
4679 /* If TYPE is a padded type, see if it agrees with any size and alignment
4680 we were given. If so, return the original type. Otherwise, strip
4681 off the padding, since we will either be returning the inner type
4682 or repadding it. If no size or alignment is specified, use that of
4683 the original padded type. */
4686 {
4703 }
4705 /* If the size is either not being changed or is being made smaller (which
4706 is not done here (and is only valid for bitfields anyway), show the size
4707 isn't changing. Likewise, clear the alignment if it isn't being
4708 changed. Then return if we aren't doing anything. */
4722 /* We used to modify the record in place in some cases, but that could
4723 generate incorrect debugging information. So make a new record
4724 type and name. */
4730 /* If we were making a type, complete the original type and give it a
4731 name. */
4739 /* If we are changing the alignment and the input type is a record with
4740 BLKmode and a small constant size, try to make a form that has an
4741 integral mode. That might allow this record to have an integral mode,
4742 which will be much more efficient. There is no point in doing this if a
4743 size is specified unless it is also smaller than the biggest alignment
4744 and it is incorrect to do this if the size of the original type is not a
4745 multiple of the alignment. */
4765 bitsize_unit_node));
4772 /* Keep the RM_Size of the padded record as that of the old record
4773 if requested. */
4776 /* Unless debugging information isn't being written for the input type,
4777 write a record that shows what we are a subtype of and also make a
4778 variable that indicates our size, if variable. */
4783 {
4802 }
4809 /* If the size was widened explicitly, maybe give a warning. */
4815 {
4828 /* Generate message only for entities that come from source, since
4829 if we have an entity created by expansion, the message will be
4830 generated for some other corresponding source entity. */
4833 gnat_entity,
4840 }
4843 }
4844 \f
4845 /* Given a GNU tree and a GNAT list of choices, generate an expression to test
4846 the value passed against the list of choices. */
4848 tree
4850 {
4851 Node_Id choice;
4852 Node_Id gnat_temp;
4857 {
4859 {
4864 /* There's no good type to use here, so we might as well use
4865 integer_type_node. */
4866 this_test
4880 this_test
4890 /* This represents either a subtype range, an enumeration
4891 literal, or a constant Ekind says which. If an enumeration
4892 literal or constant, fall through to the next case. */
4895 {
4901 this_test
4908 }
4909 /* ... fall through ... */
4914 single);
4923 }
4927 }
4930 }
4931 \f
4932 /* Return a GCC tree for a field corresponding to GNAT_FIELD to be
4933 placed in GNU_RECORD_TYPE.
4935 PACKED is 1 if the enclosing record is packed and -1 if the enclosing
4936 record has a Component_Alignment of Storage_Unit.
4938 DEFINITION is nonzero if this field is for a record being defined. */
4940 static tree
4942 tree gnu_record_type,
4945 {
4951 tree gnu_field;
4952 int needs_strict_alignment
4956 /* If this field requires strict alignment or contains an item of
4957 variable sized, pretend it isn't packed. */
4961 /* For packed records, this is one of the few occasions on which we use
4962 the official RM size for discrete or fixed-point components, instead
4963 of the normal GNAT size stored in Esize. See description in Einfo:
4964 "Handling of Type'Size Values" for further details. */
4974 /* If the field's type is left-justified modular, the wrapper can prevent
4975 packing so we make the field the type of the inner object unless the
4976 situation forbids it. We may not do that when the field is addressable_p,
4977 typically because in that case this field may later be passed by-ref for
4978 a formal argument expecting the left justification. The condition below
4979 is then matching the addressable_p code for COMPONENT_REF. */
4985 /* If we are packing this record or we have a specified size that's
4986 smaller than that of the field type and the field type is also a record
4987 that's BLKmode and with a small constant size, see if we can get a
4988 better form of the type that allows more packing. If we can, show
4989 a size was specified for it if there wasn't one so we know to
4990 make this a bitfield and avoid making things wider. */
4995 && (packed
4998 {
5003 }
5005 /* If we are packing the record and the field is BLKmode, round the
5006 size up to a byte boundary. */
5011 {
5016 /* Ensure the position does not overlap with the parent subtype,
5017 if there is one. */
5019 {
5020 tree gnu_parent
5026 {
5027 post_error_ne_tree
5031 }
5032 }
5034 /* If this field needs strict alignment, ensure the record is
5035 sufficiently aligned and that that position and size are
5036 consistent with the alignment. */
5038 {
5045 /* If Atomic, the size must match exactly and if aliased, the size
5046 must not be less than the rounded size. */
5049 {
5050 post_error_ne_tree
5056 }
5061 {
5062 post_error_ne_tree
5065 gnu_min_size);
5067 }
5072 {
5074 post_error_ne_num
5080 post_error_ne_num
5086 post_error_ne_num
5090 else
5094 }
5096 /* If an error set the size to zero, show we have no position
5097 either. */
5100 }
5104 }
5106 /* If the record has rep clauses and this is the tag field, make a rep
5107 clause for it as well. */
5110 {
5113 }
5115 /* We need to make the size the maximum for the type if it is
5116 self-referential and an unconstrained type. In that case, we can't
5117 pack the field since we can't make a copy to align it. */
5122 {
5125 }
5127 /* If no size is specified (or if there was an error), don't specify a
5128 position. */
5131 else
5132 {
5133 /* Unless this field is aliased, we can remove any left-justified
5134 modular type since it's only needed in the unchecked conversion
5135 case, which doesn't apply here. */
5141 gnu_field_type
5146 }
5152 /* Now create the decl for the field. */
5165 }
5166 \f
5167 /* Return 1 if TYPE is a type with variable size, a padding type with a field
5168 of variable size or is a record that has a field such a field. */
5170 static int
5172 {
5173 tree field;
5175 /* We need not be concerned about this at all if we don't have
5176 strict alignment. */
5194 }
5195 \f
5196 /* Return a GCC tree for a record type given a GNAT Component_List and a chain
5197 of GCC trees for fields that are in the record and have already been
5198 processed. When called from gnat_to_gnu_entity during the processing of a
5199 record type definition, the GCC nodes for the discriminants will be on
5200 the chain. The other calls to this function are recursive calls from
5201 itself for the Component_List of a variant and the chain is empty.
5203 PACKED is 1 if this is for a record with "pragma pack" and -1 is this is
5204 for a record type with "pragma component_alignment (storage_unit)".
5206 FINISH_RECORD is nonzero if this call will supply all of the remaining
5207 fields of the record.
5209 P_GNU_REP_LIST, if nonzero, is a pointer to a list to which each field
5210 with a rep clause is to be added. If it is nonzero, that is all that
5211 should be done with such fields.
5213 CANCEL_ALIGNMENT, if nonzero, means the alignment should be zeroed
5214 before laying out the record. This means the alignment only serves
5215 to force fields to be bitfields, but not require the record to be
5216 that aligned. This is used for variants.
5218 ALL_REP, if nonzero, means that a rep clause was found for all the
5219 fields. This simplifies the logic since we know we're not in the mixed
5220 case.
5222 The processing of the component list fills in the chain with all of the
5223 fields of the record and then the record type is finished. */
5225 static void
5227 Node_Id component_list,
5228 tree gnu_field_list,
5234 {
5235 Node_Id component_decl;
5236 Entity_Id gnat_field;
5237 Node_Id variant_part;
5238 Node_Id variant;
5244 /* For each variable within each component declaration create a GCC field
5245 and add it to the list, skipping any pragmas in the list. */
5251 {
5256 else
5257 {
5261 /* If this is the _Tag field, put it before any discriminants,
5262 instead of after them as is the case for all other fields.
5263 Ignore field of void type if only annotating. */
5266 else
5267 {
5270 }
5271 }
5274 }
5276 /* At the end of the component list there may be a variant part. */
5279 /* If this is an unchecked union, each variant must have exactly one
5280 component, each of which becomes one component of this union. */
5285 {
5286 component_decl
5290 definition);
5294 }
5296 /* We create a QUAL_UNION_TYPE for the variant part since the variants are
5297 mutually exclusive and should go in the same memory. To do this we need
5298 to treat each variant as a record whose elements are created from the
5299 component list for the variant. So here we create the records from the
5300 lists for the variants and put them all into the QUAL_UNION_TYPE. */
5302 {
5304 Node_Id variant;
5306 tree gnu_union_field;
5309 tree gnu_var_name
5310 = concat_id_with_name
5324 {
5326 tree gnu_inner_name;
5327 tree gnu_qual;
5335 /* Set the alignment of the inner type in case we need to make
5336 inner objects into bitfields, but then clear it out
5337 so the record actually gets only the alignment required. */
5341 /* Similarly, if the outer record has a size specified and all fields
5342 have record rep clauses, we can propagate the size into the
5343 variant part. */
5345 {
5349 }
5361 (all_rep_and_size
5363 (all_rep_and_size
5371 }
5373 /* We use to delete the empty variants from the end. However,
5374 we no longer do that because we need them to generate complete
5375 debugging information for the variant record. Otherwise,
5376 the union type definition will be missing the fields associated
5377 to these empty variants. */
5379 /* Only make the QUAL_UNION_TYPE if there are any non-empty variants. */
5381 {
5383 {
5387 }
5392 gnu_union_field
5394 packed,
5401 }
5402 }
5404 /* Scan GNU_FIELD_LIST and see if any fields have rep clauses. If they
5405 do, pull them out and put them into GNU_OUR_REP_LIST. We have to do this
5406 in a separate pass since we want to handle the discriminants but can't
5407 play with them until we've used them in debugging data above.
5409 ??? Note: if we then reorder them, debugging information will be wrong,
5410 but there's nothing that can be done about this at the moment. */
5413 {
5415 {
5420 else
5426 }
5427 else
5428 {
5431 }
5432 }
5434 /* If we have any items in our rep'ed field list, it is not the case that all
5435 the fields in the record have rep clauses, and P_REP_LIST is nonzero,
5436 set it and ignore the items. Otherwise, sort the fields by bit position
5437 and put them into their own record if we have any fields without
5438 rep clauses. */
5442 {
5443 tree gnu_rep_type
5449 /* Set DECL_SECTION_NAME to increasing integers so we have a
5450 stable sort. */
5453 {
5456 }
5460 /* Put the fields in the list in order of increasing position, which
5461 means we start from the end. */
5464 {
5469 }
5472 {
5478 }
5479 else
5480 {
5483 }
5484 }
5491 }
5492 \f
5493 /* Called via qsort from the above. Returns -1, 1, depending on the
5494 bit positions and ordinals of the two fields. */
5496 static int
5498 {
5503 return
5508 else
5510 }
5511 \f
5512 /* Given GNU_SIZE, a GCC tree representing a size, return a Uint to be
5513 placed into an Esize, Component_Bit_Offset, or Component_Size value
5514 in the GNAT tree. */
5516 static Uint
5518 {
5520 TCode tcode;
5525 /* If back annotation is suppressed by the front end, return No_Uint */
5529 /* See if we've already saved the value for this node. */
5534 /* If we do not return inside this switch, TCODE will be set to the
5535 code to use for a Create_Node operand and LEN (set above) will be
5536 the number of recursive calls for us to make. */
5539 {
5544 /* This may have come from a conversion from some smaller type,
5545 so ensure this is in bitsizetype. */
5548 /* For negative values, use NEGATE_EXPR of the supplied value. */
5550 {
5551 /* The rediculous code below is to handle the case of the largest
5552 negative integer. */
5555 tree temp;
5558 {
5559 negative_size
5562 bitsize_one_node));
5564 }
5571 }
5578 /* This peculiar test is to make sure that the size fits in an int
5579 on machines where HOST_WIDE_INT is not "int". */
5582 else
5586 /* The only case we handle here is a simple discriminant reference. */
5594 else
5600 /* Now just list the operations we handle. */
5631 }
5633 /* Now get each of the operands that's relevant for this code. If any
5634 cannot be expressed as a repinfo node, say we can't. */
5639 {
5643 }
5648 }
5650 /* Given GNAT_ENTITY, a record type, and GNU_TYPE, its corresponding
5651 GCC type, set Component_Bit_Offset and Esize to the position and size
5652 used by Gigi. */
5654 static void
5656 {
5657 tree gnu_list;
5658 tree gnu_entry;
5659 Entity_Id gnat_field;
5661 /* We operate by first making a list of all field and their positions
5662 (we can get the sizes easily at any time) by a recursive call
5663 and then update all the sizes into the tree. */
5666 BIGGEST_ALIGNMENT);
5673 {
5676 gnu_entry
5678 gnu_list);
5681 {
5683 {
5684 /* In this mode the tag and parent components have not been
5685 generated, so we add the appropriate offset to each
5686 component. For a component appearing in the current
5687 extension, the offset is the size of the parent. */
5690 parent_offset
5692 bitsizetype);
5693 else
5695 }
5697 Set_Component_Bit_Offset
5699 annotate_value
5704 parent_offset)));
5708 }
5712 {
5713 /* If there is no gnu_entry, this is an inherited component whose
5714 position is the same as in the parent type. */
5715 Set_Component_Bit_Offset
5720 }
5721 }
5722 }
5724 /* Scan all fields in GNU_TYPE and build entries where TREE_PURPOSE is the
5725 FIELD_DECL and TREE_VALUE a TREE_LIST with TREE_PURPOSE being the byte
5726 position and TREE_VALUE being a TREE_LIST with TREE_PURPOSE the value to be
5727 placed into DECL_OFFSET_ALIGN and TREE_VALUE the bit position. GNU_POS is
5728 to be added to the position, GNU_BITPOS to the bit position, OFFSET_ALIGN is
5729 the present value of DECL_OFFSET_ALIGN and GNU_LIST is a list of the entries
5730 so far. */
5732 static tree
5734 tree gnu_list,
5735 tree gnu_pos,
5736 tree gnu_bitpos,
5738 {
5739 tree gnu_field;
5744 {
5749 unsigned int our_offset_align
5752 gnu_result
5757 NULL_TREE),
5758 gnu_result);
5761 gnu_result
5764 our_offset_align);
5765 }
5768 }
5769 \f
5770 /* UINT_SIZE is a Uint giving the specified size for an object of GNU_TYPE
5771 corresponding to GNAT_OBJECT. If size is valid, return a tree corresponding
5772 to its value. Otherwise return 0. KIND is VAR_DECL is we are specifying
5773 the size for an object, TYPE_DECL for the size of a type, and FIELD_DECL
5774 for the size of a field. COMPONENT_P is true if we are being called
5775 to process the Component_Size of GNAT_OBJECT. This is used for error
5776 message handling and to indicate to use the object size of GNU_TYPE.
5777 ZERO_OK is nonzero if a size of zero is permitted; if ZERO_OK is zero,
5778 it means that a size of zero should be treated as an unspecified size. */
5780 static tree
5783 {
5784 Node_Id gnat_error_node;
5785 tree type_size
5787 tree size;
5789 /* Find the node to use for errors. */
5796 else
5799 /* Return 0 if no size was specified, either because Esize was not Present or
5800 the specified size was zero. */
5804 /* Get the size as a tree. Give an error if a size was specified, but cannot
5805 be represented as in sizetype. */
5808 {
5813 }
5814 /* Ignore a negative size since that corresponds to our back-annotation.
5815 Also ignore a zero size unless a size clause exists. */
5819 /* The size of objects is always a multiple of a byte. */
5822 bitsize_unit_node)))
5823 {
5827 else
5831 }
5833 /* If this is an integral type or a packed array type, the front-end has
5834 verified the size, so we need not do it here (which would entail
5835 checking against the bounds). However, if this is an aliased object, it
5836 may not be smaller than the type of the object. */
5841 /* If the object is a record that contains a template, add the size of
5842 the template to the specified size. */
5847 /* Modify the size of the type to be that of the maximum size if it has a
5848 discriminant or the size of a thin pointer if this is a fat pointer. */
5854 /* If this is an access type, the minimum size is that given by the smallest
5855 integral mode that's valid for pointers. */
5857 {
5863 ;
5866 }
5868 /* If the size of the object is a constant, the new size must not be
5869 smaller. */
5873 {
5875 post_error_ne_tree
5878 else
5885 post_error_ne_tree_2
5895 }
5898 }
5899 \f
5900 /* Similarly, but both validate and process a value of RM_Size. This
5901 routine is only called for types. */
5903 static void
5905 {
5906 /* Only give an error if a Value_Size clause was explicitly given.
5907 Otherwise, we'd be duplicating an error on the Size clause. */
5908 Node_Id gnat_attr_node
5911 tree size;
5913 /* Get the size as a tree. Do nothing if none was specified, either
5914 because RM_Size was not Present or if the specified size was zero.
5915 Give an error if a size was specified, but cannot be represented as
5916 in sizetype. */
5922 {
5925 gnat_entity);
5928 }
5930 /* Ignore a negative size since that corresponds to our back-annotation.
5931 Also ignore a zero size unless a size clause exists, a Value_Size
5932 clause exists, or this is an integer type, in which case the
5933 front end will have always set it. */
5940 /* If the old size is self-referential, get the maximum size. */
5944 /* If the size of the object is a constant, the new size must not be
5945 smaller (the front end checks this for scalar types). */
5950 {
5952 post_error_ne_tree
5957 }
5959 /* Otherwise, set the RM_Size. */
5970 }
5971 \f
5972 /* Given a type TYPE, return a new type whose size is appropriate for SIZE.
5973 If TYPE is the best type, return it. Otherwise, make a new type. We
5974 only support new integral and pointer types. BIASED_P is nonzero if
5975 we are making a biased type. */
5977 static tree
5979 {
5980 tree new_type;
5983 /* If size indicates an error, just return TYPE to avoid propagating the
5984 error. Likewise if it's too large to represent. */
5990 {
5993 /* Only do something if the type is not already the proper size and is
5994 not a packed array type. */
6019 /* Do something if this is a fat pointer, in which case we
6020 may need to return the thin pointer. */
6022 return
6023 build_pointer_type
6028 /* Only do something if this is a thin pointer, in which case we
6029 may need to return the fat pointer. */
6031 return
6038 }
6041 }
6042 \f
6043 /* ALIGNMENT is a Uint giving the alignment specified for GNAT_ENTITY,
6044 a type or object whose present alignment is ALIGN. If this alignment is
6045 valid, return it. Otherwise, give an error and return ALIGN. */
6047 static unsigned int
6049 {
6053 #ifndef MAX_OFILE_ALIGNMENT
6054 #define MAX_OFILE_ALIGNMENT BIGGEST_ALIGNMENT
6055 #endif
6060 /* Don't worry about checking alignment if alignment was not specified
6061 by the source program and we already posted an error for this entity. */
6066 /* Within GCC, an alignment is an integer, so we must make sure a
6067 value is specified that fits in that range. Also, alignments of
6068 more than MAX_OFILE_ALIGNMENT can't be supported. */
6082 else
6086 }
6087 \f
6088 /* Verify that OBJECT, a type or decl, is something we can implement
6089 atomically. If not, give an error for GNAT_ENTITY. COMP_P is nonzero
6090 if we require atomic components. */
6092 static void
6094 {
6096 Node_Id gnat_node;
6099 tree size;
6101 /* There are three case of what OBJECT can be. It can be a type, in which
6102 case we take the size, alignment and mode from the type. It can be a
6103 declaration that was indirect, in which case the relevant values are
6104 that of the type being pointed to, or it can be a normal declaration,
6105 in which case the values are of the decl. The code below assumes that
6106 OBJECT is either a type or a decl. */
6108 {
6112 }
6114 {
6118 }
6119 else
6120 {
6124 }
6126 /* Consider all floating-point types atomic and any types that that are
6127 represented by integers no wider than a machine word. */
6134 /* For the moment, also allow anything that has an alignment equal
6135 to its size and which is smaller than a word. */
6143 {
6151 }
6156 else
6159 }
6160 \f
6161 /* Given a type T, a FIELD_DECL F, and a replacement value R,
6162 return a new type with all size expressions that contain F
6163 updated by replacing F with R. This is identical to GCC's
6164 substitute_in_type except that it knows about TYPE_INDEX_TYPE.
6165 If F is NULL_TREE, always make a new RECORD_TYPE, even if nothing has
6166 changed. */
6168 tree
6170 {
6172 tree tem;
6175 {
6182 {
6194 }
6203 {
6217 }
6233 /* Don't know how to do these yet. */
6237 {
6251 }
6256 {
6257 tree field;
6258 int changed_field
6265 /* Start out with no fields, make new fields, and chain them
6266 in. If we haven't actually changed the type of any field,
6267 discard everything we've done and return the old type. */
6274 {
6285 /* If this is an internal field and the type of this field is
6286 a UNION_TYPE or RECORD_TYPE with no elements, ignore it. If
6287 the type just has one element, treat that as the field.
6288 But don't do this if we are processing a QUAL_UNION_TYPE. */
6293 {
6298 {
6299 tree next_new_field
6302 /* Make sure omitting the union doesn't change
6303 the layout. */
6306 }
6307 }
6314 /* If the size of the old field was set at a constant,
6315 propagate the size in case the type's size was variable.
6316 (This occurs in the case of a variant or discriminated
6317 record with a default size used as a field of another
6318 record.) */
6327 {
6333 /* Do the substitution inside the qualifier and if we find
6334 that this field will not be present, omit it. */
6339 }
6343 else
6348 /* If this is a qualified type and this field will always be
6349 present, we are done. */
6353 }
6355 /* If this used to be a qualified union type, but we now know what
6356 field will be present, make this a normal union. */
6369 /* If the size was originally a constant use it. */
6372 {
6376 }
6379 }
6383 }
6384 }
6385 \f
6386 /* Return the "RM size" of GNU_TYPE. This is the actual number of bits
6387 needed to represent the object. */
6389 tree
6391 {
6392 /* For integer types, this is the precision. For record types, we store
6393 the size explicitly. For other types, this is just the size. */
6399 /* Return the rm_size of the actual data plus the size of the template. */
6400 return
6410 else
6412 }
6413 \f
6414 /* Return an identifier representing the external name to be used for
6415 GNAT_ENTITY. If SUFFIX is specified, the name is followed by "___"
6416 and the specified suffix. */
6418 tree
6420 {
6427 #ifdef _WIN32
6428 /* A variable using the Stdcall convention (meaning we are running
6429 on a Windows box) live in a DLL. Here we adjust its name to use
6430 the jump-table, the _imp__NAME contains the address for the NAME
6431 variable. */
6433 {
6440 {
6445 }
6446 }
6447 #endif
6450 }
6452 /* Return the name to be used for GNAT_ENTITY. If a type, create a
6453 fully-qualified name, possibly with type information encoding.
6454 Otherwise, return the name. */
6456 tree
6458 {
6461 }
6463 /* Given GNU_ID, an IDENTIFIER_NODE containing a name and SUFFIX, a
6464 string, return a new IDENTIFIER_NODE that is the concatenation of
6465 the name in GNU_ID and SUFFIX. */
6467 tree
6469 {
6478 }