| blob | adf1d35744bd9d9d3bfe3f0df1ac90bc76f43bf9 |
1 /****************************************************************************
2 * *
3 * GNAT COMPILER COMPONENTS *
4 * *
5 * D E C L *
6 * *
7 * C Implementation File *
8 * *
9 * *
10 * Copyright (C) 1992-2002, Free Software Foundation, Inc. *
11 * *
12 * GNAT is free software; you can redistribute it and/or modify it under *
13 * terms of the GNU General Public License as published by the Free Soft- *
14 * ware Foundation; either version 2, or (at your option) any later ver- *
15 * sion. GNAT is distributed in the hope that it will be useful, but WITH- *
16 * OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY *
17 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License *
18 * for more details. You should have received a copy of the GNU General *
19 * Public License distributed with GNAT; see file COPYING. If not, write *
20 * to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, *
21 * MA 02111-1307, USA. *
22 * *
23 * GNAT was originally developed by the GNAT team at New York University. *
24 * It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). *
25 * *
26 ****************************************************************************/
53 /* Setting this to 1 suppresses hashing of types. */
56 /* Provide default values for the macros controlling stack checking.
57 This is copied from GCC's expr.h. */
59 #ifndef STACK_CHECK_BUILTIN
60 #define STACK_CHECK_BUILTIN 0
61 #endif
62 #ifndef STACK_CHECK_PROBE_INTERVAL
63 #define STACK_CHECK_PROBE_INTERVAL 4096
64 #endif
65 #ifndef STACK_CHECK_MAX_FRAME_SIZE
66 #define STACK_CHECK_MAX_FRAME_SIZE \
67 (STACK_CHECK_PROBE_INTERVAL - UNITS_PER_WORD)
68 #endif
69 #ifndef STACK_CHECK_MAX_VAR_SIZE
70 #define STACK_CHECK_MAX_VAR_SIZE (STACK_CHECK_MAX_FRAME_SIZE / 100)
71 #endif
73 /* These two variables are used to defer recursively expanding incomplete
74 types while we are processing a record or subprogram type. */
77 static struct incomplete
78 {
80 tree old_type;
81 Entity_Id full_type;
111 \f
112 /* Given GNAT_ENTITY, an entity in the incoming GNAT tree, return a
113 GCC type corresponding to that entity. GNAT_ENTITY is assumed to
114 refer to an Ada type. */
116 tree
118 Entity_Id gnat_entity;
119 {
120 tree gnu_decl;
122 /* Convert the ada entity type into a GCC TYPE_DECL node. */
128 }
129 \f
130 /* Given GNAT_ENTITY, a GNAT defining identifier node, which denotes some Ada
131 entity, this routine returns the equivalent GCC tree for that entity
132 (an ..._DECL node) and associates the ..._DECL node with the input GNAT
133 defining identifier.
135 If GNAT_ENTITY is a variable or a constant declaration, GNU_EXPR gives its
136 initial value (in GCC tree form). This is optional for variables.
137 For renamed entities, GNU_EXPR gives the object being renamed.
139 DEFINITION is nonzero if this call is intended for a definition. This is
140 used for separate compilation where it necessary to know whether an
141 external declaration or a definition should be created if the GCC equivalent
142 was not created previously. The value of 1 is normally used for a non-zero
143 DEFINITION, but a value of 2 is used in special circumstances, defined in
144 the code. */
146 tree
148 Entity_Id gnat_entity;
149 tree gnu_expr;
151 {
152 tree gnu_entity_id;
154 /* Contains the gnu XXXX_DECL tree node which is equivalent to the input
155 GNAT tree. This node will be associated with the GNAT node by calling
156 the save_gnu_tree routine at the end of the `switch' statement. */
158 /* Nonzero if we have already saved gnu_decl as a gnat association. */
160 /* Nonzero if we incremented defer_incomplete_level. */
162 /* Nonzero if we incremented force_global. */
164 /* Nonzero if we should check to see if elaborated during processing. */
166 /* Nonzero if we made GNU_DECL and its type here. */
172 Entity_Id gnat_temp;
173 unsigned int esize
178 ? LONG_DOUBLE_TYPE_SIZE
183 int imported_p
188 /* Since a use of an Itype is a definition, process it as such if it
189 is not in a with'ed unit. */
194 {
195 /* Ensure that we are in a subprogram mentioned in the Scope
196 chain of this entity, our current scope is global,
197 or that we encountered a task or entry (where we can't currently
198 accurately check scoping). */
201 {
204 }
208 {
213 gnat_temp
225 && (current_function_decl
227 {
230 }
231 }
233 /* gigi abort 122 means that the entity "gnat_entity" has an incorrect
234 scope, i.e. that its scope does not correspond to the subprogram
235 in which it is declared */
237 }
239 /* If this is entity 0, something went badly wrong. */
243 /* If we've already processed this entity, return what we got last time.
244 If we are defining the node, we should not have already processed it.
245 In that case, we will abort below when we try to save a new GCC tree for
246 this object. We also need to handle the case of getting a dummy type
247 when a Full_View exists. */
250 && (! definition
252 {
259 {
265 }
268 }
270 /* If this is a numeric or enumeral type, or an access type, a nonzero
271 Esize must be specified unless it was specified by the programmer. */
280 /* Likewise, RM_Size must be specified for all discrete and fixed-point
281 types. */
286 /* Get the name of the entity and set up the line number and filename of
287 the original definition for use in any decl we make. */
292 /* If we get here, it means we have not yet done anything with this
293 entity. If we are not defining it here, it must be external,
294 otherwise we should have defined it already. */
296 && ! type_annotate_only
300 #if 1
302 #endif
303 )
306 /* For cases when we are not defining (i.e., we are referencing from
307 another compilation unit) Public entities, show we are at global level
308 for the purpose of computing sizes. Don't do this for components or
309 discriminants since the relevant test is whether or not the record is
310 being defined. */
316 /* Handle any attributes. */
321 {
323 /* If this is a use of a deferred constant, get its full
324 declaration. */
326 {
331 }
333 /* If we have an external constant that we are not defining,
334 get the expression that is was defined to represent. We
335 may throw that expression away later if it is not a
336 constant. */
342 /* Ignore deferred constant definitions; they are processed fully in the
343 front-end. For deferred constant references, get the full
344 definition. On the other hand, constants that are renamings are
345 handled like variable renamings. If No_Initialization is set, this is
346 not a deferred constant but a constant whose value is built
347 manually. */
352 {
356 }
359 {
364 }
369 /* If this is not a VMS exception, treat it as a normal object.
370 Otherwise, make an object at the specific address of character
371 type, point to it, and convert it to integer, and mask off
372 the lower 3 bits. */
376 /* Allocate the global object that we use to get the value of the
377 exception. */
385 /* Now return the expression giving the desired value. */
386 gnu_decl
390 gnu_decl)),
400 {
401 /* The GNAT record where the component was defined. */
404 /* If the variable is an inherited record component (in the case of
405 extended record types), just return the inherited entity, which
406 must be a FIELD_DECL. Likewise for discriminants.
407 For discriminants of untagged records which have explicit
408 girder discriminants, return the entity for the corresponding
409 girder discriminant. Also use Original_Record_Component
410 if the record has a private extension. */
417 {
418 gnu_decl
423 }
425 /* If the enclosing record has explicit girder discriminants,
426 then it is an untagged record. If the Corresponding_Discriminant
427 is not empty then this must be a renamed discriminant and its
428 Original_Record_Component must point to the corresponding explicit
429 girder discriminant (i.e., we should have taken the previous
430 branch). */
434 {
435 /* A tagged record has no explicit girder discriminants. */
441 gnu_decl
446 }
448 /* If the enclosing record has explicit girder discriminants,
449 then it is an untagged record. If the Corresponding_Discriminant
450 is not empty then this must be a renamed discriminant and its
451 Original_Record_Component must point to the corresponding explicit
452 girder discriminant (i.e., we should have taken the first
453 branch). */
460 /* Otherwise, if we are not defining this and we have no GCC type
461 for the containing record, make one for it. Then we should
462 have made our own equivalent. */
464 {
465 /* ??? If this is in a record whose scope is a protected
466 type and we have an Original_Record_Component, use it.
467 This is a workaround for major problems in protected type
468 handling. */
471 {
472 gnu_decl
478 }
484 }
486 /* Here we have no GCC type and this is a reference rather than a
487 definition. This should never happen. Most likely the cause is a
488 reference before declaration in the gnat tree for gnat_entity. */
489 else
491 }
497 /* Simple variables, loop variables, OUT parameters, and exceptions. */
498 object:
499 {
501 int const_flag
514 {
518 else
520 }
522 /* Get the type after elaborating the renamed object. */
525 /* If this is a loop variable, its type should be the base type.
526 This is because the code for processing a loop determines whether
527 a normal loop end test can be done by comparing the bounds of the
528 loop against those of the base type, which is presumed to be the
529 size used for computation. But this is not correct when the size
530 of the subtype is smaller than the type. */
534 /* Reject non-renamed objects whose types are unconstrained arrays or
535 any object whose type is a dummy type or VOID_TYPE. */
541 {
544 else
546 }
548 /* If we are defining the object, see if it has a Size value and
549 validate it if so. Then get the new type, if any. */
556 {
557 gnu_type
563 }
565 /* If this object has self-referential size, it must be a record with
566 a default value. We are supposed to allocate an object of the
567 maximum size in this case unless it is a constant with an
568 initializing expression, in which case we can get the size from
569 that. Note that the resulting size may still be a variable, so
570 this may end up with an indirect allocation. */
575 {
577 {
581 {
587 }
588 }
590 /* We may have no GNU_EXPR because No_Initialization is
591 set even though there's an Expression. */
596 gnu_size
598 (Etype
600 else
602 }
604 /* If the size is zero bytes, make it one byte since some linkers
605 have trouble with zero-sized objects. But if this will have a
606 template, that will make it nonzero. */
614 /* If an alignment is specified, use it if valid. Note that
615 exceptions are objects but don't have alignments. */
617 {
621 align
624 }
626 /* If this is an atomic object with no specified size and alignment,
627 but where the size of the type is a constant, set the alignment to
628 the lowest power of two greater than the size, or to the
629 biggest meaningful alignment, whichever is smaller. */
633 {
636 BIGGEST_ALIGNMENT))
638 else
643 }
645 #ifdef MINIMUM_ATOMIC_ALIGNMENT
646 /* If the size is a constant and no alignment is specified, force
647 the alignment to be the minimum valid atomic alignment. The
648 restriction on constant size avoids problems with variable-size
649 temporaries; if the size is variable, there's no issue with
650 atomic access. Also don't do this for a constant, since it isn't
651 necessary and can interfere with constant replacement. Finally,
652 do not do it for Out parameters since that creates an
653 size inconsistency with In parameters. */
662 #endif
664 /* If the object is set to have atomic components, find the component
665 type and validate it.
667 ??? Note that we ignore Has_Volatile_Components on objects; it's
668 not at all clear what to do in that case. */
671 {
672 tree gnu_inner
681 }
683 /* Now check if the type of the object allows atomic access. Note
684 that we must test the type, even if this object has size and
685 alignment to allow such access, because we will be going
686 inside the padded record to assign to the object. We could fix
687 this by always copying via an intermediate value, but it's not
688 clear it's worth the effort. */
692 /* Make a new type with the desired size and alignment, if needed. */
696 /* Make a volatile version of this object's type if we are to
697 make the object volatile. Note that 13.3(19) says that we
698 should treat other types of objects as volatile as well. */
708 /* If this is an aliased object with an unconstrained nominal subtype,
709 make a type that includes the template. */
713 {
714 tree gnu_fat
716 tree gnu_temp_type
719 gnu_type
723 }
725 /* Convert the expression to the type of the object except in the
726 case where the object's type is unconstrained or the object's type
727 is a padded record whose field is of self-referential size. In
728 the former case, converting will generate unnecessary evaluations
729 of the CONSTRUCTOR to compute the size and in the latter case, we
730 want to only copy the actual data. */
737 && (contains_placeholder_p
741 /* See if this is a renaming. If this is a constant renaming,
742 treat it as a normal variable whose initial value is what
743 is being renamed. We cannot do this if the type is
744 unconstrained or class-wide.
746 Otherwise, if what we are renaming is a reference, we can simply
747 return a stabilized version of that reference, after forcing
748 any SAVE_EXPRs to be evaluated. But, if this is at global level,
749 we can only do this if we know no SAVE_EXPRs will be made.
750 Otherwise, make this into a constant pointer to the object we are
751 to rename. */
754 {
755 /* If the renamed object had padding, strip off the reference
756 to the inner object and reset our type. */
760 && (TYPE_IS_PADDING_P
762 {
765 }
772 ;
774 /* If this is a declaration or reference, we can just use that
775 declaration or reference as this entity. */
782 {
790 gnu_decl));
792 }
793 else
794 {
801 }
802 }
804 /* If this is an aliased object whose nominal subtype is unconstrained,
805 the object is a record that contains both the template and
806 the object. If there is an initializer, it will have already
807 been converted to the right type, but we need to create the
808 template if there is no initializer. */
812 gnu_expr
813 = build_constructor
815 tree_cons
817 build_template
820 NULL_TREE),
821 NULL_TREE));
823 /* If this is a pointer and it does not have an initializing
824 expression, initialize it to NULL. */
830 /* If we are defining the object and it has an Address clause we must
831 get the address expression from the saved GCC tree for the
832 object if the object has a Freeze_Node. Otherwise, we elaborate
833 the address expression here since the front-end has guaranteed
834 in that case that the elaboration has no effects. Note that
835 only the latter mechanism is currently in use. */
837 {
838 tree gnu_address
844 /* Ignore the size. It's either meaningless or was handled
845 above. */
852 /* If we don't have an initializing expression for the underlying
853 variable, the initializing expression for the pointer is the
854 specified address. Otherwise, we have to make a COMPOUND_EXPR
855 to assign both the address and the initial value. */
858 else
859 gnu_expr
861 build_binary_op
864 gnu_address),
865 gnu_expr),
866 gnu_address);
867 }
869 /* If it has an address clause and we are not defining it, mark it
870 as an indirect object. Likewise for Stdcall objects that are
871 imported. */
875 {
879 }
881 /* If we are at top level and this object is of variable size,
882 make the actual type a hidden pointer to the real type and
883 make the initializer be a memory allocation and initialization.
884 Likewise for objects we aren't defining (presumed to be
885 external references from other packages), but there we do
886 not set up an initialization.
888 If the object's size overflows, make an allocator too, so that
889 Storage_Error gets raised. Note that we will never free
890 such memory, so we presume it never will get allocated. */
899 {
905 /* Get the data part of GNU_EXPR in case this was a
906 aliased object whose nominal subtype is unconstrained.
907 In that case the pointer above will be a thin pointer and
908 build_allocator will automatically make the template and
909 constructor already made above. */
912 {
917 {
918 gnu_alloc_type
920 gnu_expr
921 = build_component_ref
924 }
930 gnat_entity);
934 }
935 else
936 {
939 }
940 }
942 /* If this object would go into the stack and has an alignment
943 larger than the default largest alignment, make a variable
944 to hold the "aligning type" with a modified initial value,
945 if any, then point to it and make that the value of this
946 variable, which is now indirect. */
950 {
951 tree gnu_new_type
954 tree gnu_new_var;
957 gnu_expr
962 gnu_new_var
968 gnu_expr
969 = build_unary_op
977 }
979 /* Convert the expression to the type of the object except in the
980 case where the object's type is unconstrained or the object's type
981 is a padded record whose field is of self-referential size. In
982 the former case, converting will generate unnecessary evaluations
983 of the CONSTRUCTOR to compute the size and in the latter case, we
984 want to only copy the actual data. */
991 && (contains_placeholder_p
995 /* This name is external or there was a name specified, use it.
996 Don't use the Interface_Name if there is an address clause.
997 (see CD30005). */
1008 /* If this is constant initialized to a static constant and the
1009 object has an aggregrate type, force it to be statically
1010 allocated. */
1034 STACK_CHECK_MAX_VAR_SIZE))))
1037 /* If this is a public constant or we're not optimizing and we're not
1038 making a VAR_DECL for it, make one just for export or debugger
1039 use. Likewise if the address is taken or if the object or type is
1040 aliased. */
1052 /* If this is declared in a block that contains an block with an
1053 exception handler, we must force this variable in memory to
1054 suppress an invalid optimization. */
1057 {
1060 }
1062 /* Back-annotate the Alignment of the object if not already in the
1063 tree. Likewise for Esize if the object is of a constant size.
1064 But if the "object" is actually a pointer to an object, the
1065 alignment and size are the same as teh type, so don't back-annotate
1066 the values for the pointer. */
1073 {
1078 gnu_back_size
1083 }
1084 }
1088 /* Return a TYPE_DECL for "void" that we previously made. */
1093 /* A special case, for the types Character and Wide_Character in
1094 Standard, we do not list all the literals. So if the literals
1095 are not specified, make this an unsigned type. */
1097 {
1100 }
1102 /* Normal case of non-character type, or non-Standard character type */
1103 {
1104 /* Here we have a list of enumeral constants in First_Literal.
1105 We make a CONST_DECL for each and build into GNU_LITERAL_LIST
1106 the list to be places into TYPE_FIELDS. Each node in the list
1107 is a TREE_LIST node whose TREE_VALUE is the literal name
1108 and whose TREE_PURPOSE is the value of the literal.
1110 Esize contains the number of bits needed to represent the enumeral
1111 type, Type_Low_Bound also points to the first literal and
1112 Type_High_Bound points to the last literal. */
1114 Entity_Id gnat_literal;
1119 else
1127 {
1129 gnu_type);
1130 tree gnu_literal
1137 }
1141 /* Note that the bounds are updated at the end of this function
1142 because to avoid an infinite recursion when we get the bounds of
1143 this type, since those bounds are objects of this type. */
1144 }
1150 /* For integer types, just make a signed type the appropriate number
1151 of bits. */
1156 /* For modular types, make the unsigned type of the proper number of
1157 bits and then set up the modulus, if required. */
1158 {
1160 tree gnu_modulus;
1166 /* Find the smallest mode at least ESIZE bits wide and make a class
1167 using that mode. */
1172 ;
1178 /* Get the modulus in this type. If it overflows, assume it is because
1179 it is equal to 2**Esize. Note that there is no overflow checking
1180 done on unsigned type, so we detect the overflow by looking for
1181 a modulus of zero, which is otherwise invalid. */
1185 {
1190 }
1192 /* If we have to set TYPE_PRECISION different from its natural value,
1193 make a subtype to do do. Likewise if there is a modulus and
1194 it is not one greater than TYPE_MAX_VALUE. */
1198 {
1215 }
1216 }
1225 /* For integral subtypes, we make a new INTEGER_TYPE. Note
1226 that we do not want to call build_range_type since we would
1227 like each subtype node to be distinct. This will be important
1228 when memory aliasing is implemented.
1230 The TREE_TYPE field of the INTEGER_TYPE we make points to the
1231 parent type; this fact is used by the arithmetic conversion
1232 functions.
1234 We elaborate the Ancestor_Subtype if it is not in the current
1235 unit and one of our bounds is non-static. We do this to ensure
1236 consistent naming in the case where several subtypes share the same
1237 bounds by always elaborating the first such subtype first, thus
1238 using its name. */
1250 {
1254 }
1262 gnat_entity,
1269 gnat_entity,
1273 /* One of the above calls might have caused us to be elaborated,
1274 so don't blow up if so. */
1276 {
1279 }
1284 /* This should be an unsigned type if the lower bound is constant
1285 and non-negative or if the base type is unsigned; a signed type
1286 otherwise. */
1297 {
1299 tree gnu_field;
1312 }
1317 /* If this is a VAX floating-point type, use an integer of the proper
1318 size. All the operations will be handled with ASM statements. */
1320 {
1326 }
1328 /* The type of the Low and High bounds can be our type if this is
1329 a type from Standard, so set them at the end of the function. */
1337 {
1340 }
1342 {
1357 ;
1377 /* One of the above calls might have caused us to be elaborated,
1378 so don't blow up if so. */
1380 {
1383 }
1386 }
1389 /* Array and String Types and Subtypes
1391 Unconstrained array types are represented by E_Array_Type and
1392 constrained array types are represented by E_Array_Subtype. There
1393 are no actual objects of an unconstrained array type; all we have
1394 are pointers to that type.
1396 The following fields are defined on array types and subtypes:
1398 Component_Type Component type of the array.
1399 Number_Dimensions Number of dimensions (an int).
1400 First_Index Type of first index. */
1404 {
1410 int firstdim
1412 int nextdim
1418 tree gnu_max_size_unit;
1420 Entity_Id gnat_ind_subtype;
1421 Entity_Id gnat_ind_base_subtype;
1422 tree gnu_template_reference;
1423 tree tem;
1431 /* Make a node for the array. If we are not defining the array
1432 suppress expanding incomplete types and save the node as the type
1433 for GNAT_ENTITY. */
1436 {
1437 defer_incomplete_level++;
1441 debug_info_p);
1444 }
1446 /* Build the fat pointer type. Use a "void *" object instead of
1447 a pointer to the array type since we don't have the array type
1448 yet (it will reference the fat pointer via the bounds). */
1451 ptr_void_type_node,
1454 gnu_ptr_template,
1457 /* Make sure we can put this into a register. */
1461 /* Build a reference to the template from a PLACEHOLDER_EXPR that
1462 is the fat pointer. This will be used to access the individual
1463 fields once we build them. */
1467 gnu_template_reference
1471 /* Now create the GCC type for each index and add the fields for
1472 that index to the template. */
1474 gnat_ind_base_subtype
1480 {
1482 tree gnu_ind_subtype
1484 tree gnu_base_subtype
1486 tree gnu_base_min
1488 tree gnu_base_max
1492 /* Make the FIELD_DECLs for the minimum and maximum of this
1493 type and then make extractions of that field from the
1494 template. */
1498 gnu_ind_subtype,
1502 gnu_ind_subtype,
1507 /* We can't use build_component_ref here since the template
1508 type isn't complete yet. */
1515 /* Make a range type with the new ranges, but using
1516 the Ada subtype. Then we convert to sizetype. */
1522 /* Update the maximum size of the array, in elements. */
1523 gnu_max_size
1527 gnu_base_min)));
1531 }
1534 gnu_template_fields
1537 /* Install all the fields into the template. */
1541 /* Now make the array of arrays and update the pointer to the array
1542 in the fat pointer. Note that it is the first field. */
1546 /* Get and validate any specified Component_Size, but if Packed,
1547 ignore it since the front end will have taken care of it. Also,
1548 allow sizes not a multiple of Storage_Unit if packed. */
1549 gnu_comp_size
1551 gnat_entity,
1559 /* If the component type is a RECORD_TYPE that has a self-referential
1560 size, use the maxium size. */
1567 {
1571 }
1577 /* If Component_Size is not already specified, annotate it with the
1578 size of the component. */
1588 gnu_max_size),
1592 {
1597 }
1599 /* If an alignment is specified, use it if valid. But ignore it for
1600 types that represent the unpacked base type for packed arrays. */
1603 {
1610 }
1616 /* The result type is an UNCONSTRAINED_ARRAY_TYPE that indicates the
1617 corresponding fat pointer. */
1624 /* If the maximum size doesn't overflow, use it. */
1637 debug_info_p);
1640 /* Create a record type for the object and its template and
1641 set the template at a negative offset. */
1653 /* Give the thin pointer type a name. */
1657 }
1663 /* This is the actual data type for array variables. Multidimensional
1664 arrays are implemented in the gnu tree as arrays of arrays. Note
1665 that for the moment arrays which have sparse enumeration subtypes as
1666 index components create sparse arrays, which is obviously space
1667 inefficient but so much easier to code for now.
1669 Also note that the subtype never refers to the unconstrained
1670 array type, which is somewhat at variance with Ada semantics.
1672 First check to see if this is simply a renaming of the array
1673 type. If so, the result is the array type. */
1678 else
1679 {
1682 int first_dim
1685 int next_dim
1687 Entity_Id gnat_ind_subtype;
1688 Entity_Id gnat_ind_base_subtype;
1693 tree gnu_max_size_unit;
1697 /* First create the gnu types for each index. Create types for
1698 debugging information to point to the index types if the
1699 are not integer types, have variable bounds, or are
1700 wider than sizetype. */
1703 gnat_ind_base_subtype
1709 {
1710 tree gnu_index_subtype
1712 tree gnu_min
1714 tree gnu_max
1716 tree gnu_base_subtype
1718 tree gnu_base_min
1720 tree gnu_base_max
1723 tree gnu_base_base_min
1725 tree gnu_base_base_max
1727 tree gnu_high;
1728 tree gnu_this_max;
1730 /* If the minimum and maximum values both overflow in
1731 SIZETYPE, but the difference in the original type
1732 does not overflow in SIZETYPE, ignore the overflow
1733 indications. */
1739 && (! TREE_OVERFLOW
1747 /* Similarly, if the range is null, use bounds of 1..0 for
1748 the sizetype bounds. */
1758 /* Now compute the size of this bound. We need to provide
1759 GCC with an upper bound to use but have to deal with the
1760 "superflat" case. There are three ways to do this. If we
1761 can prove that the array can never be superflat, we can
1762 just use the high bound of the index subtype. If we can
1763 prove that the low bound minus one can't overflow, we
1764 can do this as MAX (hb, lb - 1). Otherwise, we have to use
1765 the expression hb >= lb ? hb : lb - 1. */
1768 /* See if the base array type is already flat. If it is, we
1769 are probably compiling an ACVC test, but it will cause the
1770 code below to malfunction if we don't handle it specially. */
1778 /* If gnu_high is now an integer which overflowed, the array
1779 cannot be superflat. */
1786 else
1787 gnu_high
1788 = build_cond_expr
1796 /* Also compute the maximum size of the array. Here we
1797 see if any constraint on the index type of the base type
1798 can be used in the case of self-referential bound on
1799 the index type of the subtype. We look for a non-"infinite"
1800 and non-self-referential bound from any type involved and
1801 handle each bound separately. */
1828 gnu_this_max
1832 gnu_base_min)),
1833 size_zero_node);
1839 gnu_max_size
1853 }
1855 /* Then flatten: create the array of arrays. */
1859 /* One of the above calls might have caused us to be elaborated,
1860 so don't blow up if so. */
1862 {
1865 }
1867 /* Get and validate any specified Component_Size, but if Packed,
1868 ignore it since the front end will have taken care of it. Also,
1869 allow sizes not a multiple of Storage_Unit if packed. */
1870 gnu_comp_size
1872 gnat_entity,
1877 /* If the component type is a RECORD_TYPE that has a self-referential
1878 size, use the maxium size. */
1885 {
1890 }
1903 /* We don't want any array types shared for two reasons: first,
1904 we want to keep differently-named types distinct; second,
1905 setting TYPE_MULTI_ARRAY_TYPE of one type can clobber
1906 another. */
1909 {
1914 }
1916 /* If we are at file level and this is a multi-dimensional array, we
1917 need to make a variable corresponding to the stride of the
1918 inner dimensions. */
1920 {
1922 tree gnu_arr_type;
1928 {
1934 = elaborate_expression_1
1937 }
1938 }
1940 /* If we need to write out a record type giving the names of
1941 the bounds, do it now. */
1943 {
1946 tree gnu_field;
1952 {
1953 tree gnu_type_name
1960 integer_type_node,
1961 gnu_bound_rec_type,
1965 }
1968 }
1974 /* If our size depends on a placeholder and the maximum size doesn't
1975 overflow, use it. */
1983 {
1989 }
1991 /* Set our alias set to that of our base type. This gives all
1992 array subtypes the same alias set. */
1995 }
1997 /* If this is a packed type, make this type the same as the packed
1998 array type, but do some adjusting in the type first. */
2001 {
2002 Entity_Id gnat_index;
2003 tree gnu_inner_type;
2005 /* First finish the type we had been making so that we output
2006 debugging information for it */
2009 | (TYPE_QUAL_VOLATILE
2014 debug_info_p);
2018 /* Save it as our equivalent in case the call below elaborates
2019 this type again. */
2033 /* We need to point the type we just made to our index type so
2034 the actual bounds can be put into a template. */
2040 {
2042 {
2043 /* The TYPE_ACTUAL_BOUNDS field is also used for the modulus.
2044 If it is, we need to make another type. */
2046 {
2047 tree gnu_subtype;
2064 }
2067 }
2085 }
2086 }
2088 /* Abort if packed array with no packed array type field set. */
2095 /* Create the type for a string literal. */
2096 {
2097 Entity_Id gnat_full_type
2102 tree gnu_string_array_type
2104 tree gnu_string_index_type
2106 tree gnu_lower_bound
2111 tree gnu_upper_bound
2113 gnu_lower_bound,
2115 tree gnu_range_type
2118 tree gnu_index_type
2123 gnu_range_type);
2125 gnu_type
2127 gnu_index_type);
2128 }
2131 /* Record Types and Subtypes
2133 The following fields are defined on record types:
2135 Has_Discriminants True if the record has discriminants
2136 First_Discriminant Points to head of list of discriminants
2137 First_Entity Points to head of list of fields
2138 Is_Tagged_Type True if the record is tagged
2140 Implementation of Ada records and discriminated records:
2142 A record type definition is transformed into the equivalent of a C
2143 struct definition. The fields that are the discriminants which are
2144 found in the Full_Type_Declaration node and the elements of the
2145 Component_List found in the Record_Type_Definition node. The
2146 Component_List can be a recursive structure since each Variant of
2147 the Variant_Part of the Component_List has a Component_List.
2149 Processing of a record type definition comprises starting the list of
2150 field declarations here from the discriminants and the calling the
2151 function components_to_record to add the rest of the fields from the
2152 component list and return the gnu type node. The function
2153 components_to_record will call itself recursively as it traverses
2154 the tree. */
2158 {
2159 gnu_type
2160 = build_complex_type
2161 (get_unpadded_type
2164 (Component_List
2165 (Type_Definition
2170 }
2172 {
2175 Entity_Id gnat_field;
2176 tree gnu_field;
2178 tree gnu_get_parent;
2185 int is_extension
2189 /* See if all fields have a rep clause. Stop when we find one
2190 that doesn't. */
2199 /* If this is a record extension, go a level further to find the
2200 record definition. Also, verify we have a Parent_Subtype. */
2202 {
2209 }
2211 /* Make a node for the record. If we are not defining the record,
2212 suppress expanding incomplete types and save the node as the type
2213 for GNAT_ENTITY. We use the same RECORD_TYPE as was made
2214 for a dummy type and then show it's no longer a dummy. */
2224 {
2225 defer_incomplete_level++;
2230 debug_info_p);
2233 }
2235 /* If both a size and rep clause was specified, put the size in
2236 the record type now so that it can get the proper mode. */
2240 /* Always set the alignment here so that it can be used to
2241 set the mode, if it is making the alignment stricter. If
2242 it is invalid, it will be checked again below. If this is to
2243 be Atomic, choose a default alignment of a word. */
2251 /* If we have a Parent_Subtype, make a field for the parent. If
2252 this record has rep clauses, force the position to zero. */
2254 {
2255 tree gnu_parent;
2257 /* A major complexity here is that the parent subtype will
2258 reference our discriminants. But those must reference
2259 the parent component of this record. So here we will
2260 initialize each of those components to a COMPONENT_REF.
2261 The first operand of that COMPONENT_REF is another
2262 COMPONENT_REF which will be filled in below, once
2263 the parent type can be safely built. */
2268 NULL_TREE));
2275 save_gnu_tree
2279 gnu_get_parent,
2287 gnu_field_list
2297 }
2299 /* Add the fields for the discriminants into the record. */
2305 {
2306 /* If this is a record extension and this discriminant
2307 is the renaming of another discriminant, we've already
2308 handled the discriminant above. */
2313 gnu_field
2316 /* Make an expression using a PLACEHOLDER_EXPR from the
2317 FIELD_DECL node just created and link that with the
2318 corresponding GNAT defining identifier. Then add to the
2319 list of fields. */
2324 gnu_field),
2329 }
2331 /* Put the discriminants into the record (backwards), so we can
2332 know the appropriate discriminant to use for the names of the
2333 variants. */
2336 /* Add the listed fields into the record and finish up. */
2345 /* If this is an extension type, reset the tree for any
2346 inherited discriminants. Also remove the PLACEHOLDER_EXPR
2347 for non-inherited discriminants. */
2353 {
2357 else
2358 {
2362 }
2363 }
2365 /* If it is a tagged record force the type to BLKmode to insure
2366 that these objects will always be placed in memory. Do the
2367 same thing for limited record types. */
2372 /* Fill in locations of fields. */
2375 /* If there are any entities in the chain corresponding to
2376 components that we did not elaborate, ensure we elaborate their
2377 types if they are Itypes. */
2385 }
2389 /* If an equivalent type is present, that is what we should use.
2390 Otherwise, fall through to handle this like a record subtype
2391 since it may have constraints. */
2394 {
2398 }
2400 /* ... fall through ... */
2404 /* If Cloned_Subtype is Present it means this record subtype has
2405 identical layout to that type or subtype and we should use
2406 that GCC type for this one. The front end guarantees that
2407 the component list is shared. */
2409 {
2413 }
2415 /* Otherwise, first ensure the base type is elaborated. Then, if we are
2416 changing the type, make a new type with each field having the
2417 type of the field in the new subtype but having the position
2418 computed by transforming every discriminant reference according
2419 to the constraints. We don't see any difference between
2420 private and nonprivate type here since derivations from types should
2421 have been deferred until the completion of the private type. */
2422 else
2423 {
2425 tree gnu_base_type;
2426 tree gnu_orig_type;
2431 /* Get the base type initially for its alignment and sizes. But
2432 if it is a padded type, we do all the other work with the
2433 unpadded type. */
2442 {
2445 }
2447 /* When the type has discriminants, and these discriminants
2448 affect the shape of what it built, factor them in.
2450 If we are making a subtype of an Unchecked_Union (must be an
2451 Itype), just return the type.
2453 We can't just use Is_Constrained because private subtypes without
2454 discriminants of full types with discriminants with default
2455 expressions are Is_Constrained but aren't constrained! */
2463 {
2464 Entity_Id gnat_field;
2465 Entity_Id gnat_root_type;
2467 tree gnu_pos_list
2470 BIGGEST_ALIGNMENT);
2471 tree gnu_subst_list
2473 definition);
2474 tree gnu_temp;
2476 /* If this is a derived type, we may be seeing fields from any
2477 original records, so add those positions and discriminant
2478 substitutions to our lists. */
2482 {
2483 gnu_pos_list
2484 = compute_field_positions
2487 BIGGEST_ALIGNMENT);
2490 gnu_subst_list
2493 }
2505 {
2506 tree gnu_old_field
2507 = gnat_to_gnu_entity
2509 tree gnu_offset
2511 gnu_pos_list));
2514 tree gnu_field_type
2518 unsigned int offset_align
2521 tree gnu_field;
2523 /* If there was a component clause, the field types must be
2524 the same for the type and subtype, so copy the data from
2525 the old field to avoid recomputation here. */
2528 {
2531 }
2533 /* If this was a bitfield, get the size from the old field.
2534 Also ensure the type can be placed into a bitfield. */
2536 {
2542 }
2552 /* If the size is now a constant, we can set it as the
2553 size of the field when we make it. Otherwise, we need
2554 to deal with it specially. */
2558 gnu_field
2559 = create_field_decl
2565 {
2574 bitsize_unit_node));
2576 }
2590 }
2594 /* Now set the size, alignment and alias set of the new type to
2595 match that of the old one, doing any substitutions, as
2596 above. */
2631 /* Recompute the mode of this record type now that we know its
2632 actual size. */
2635 /* Fill in locations of fields. */
2637 }
2639 /* If we've made a new type, record it and make an XVS type to show
2640 what this is a subtype of. Some debuggers require the XVS
2641 type to be output first, so do it in that order. */
2643 {
2645 {
2656 integer_type_node,
2657 gnu_subtype_marker,
2661 }
2667 gnu_type));
2671 }
2673 /* Otherwise, go down all the components in the new type and
2674 make them equivalent to those in the base type. */
2675 else
2682 get_gnu_tree
2684 }
2688 /* If we are not defining this entity, and we have incomplete
2689 entities being processed above us, make a dummy type and
2690 fill it in later. */
2692 {
2696 gnu_type
2697 = build_pointer_type
2701 debug_info_p);
2710 }
2712 /* ... fall through ... */
2719 {
2721 Entity_Id gnat_desig_full
2723 Incomplete_Or_Private_Kind))
2725 /* We want to know if we'll be seeing the freeze node for any
2726 incomplete type we may be pointing to. */
2727 int in_main_unit
2739 {
2741 {
2745 }
2747 Incomplete_Or_Private_Kind))
2749 }
2754 /* If either the designated type or its full view is an
2755 unconstrained array subtype, replace it with the type it's a
2756 subtype of. This avoids problems with multiple copies of
2757 unconstrained array types. */
2766 /* If the designated type is a subtype of an incomplete record type,
2767 use the parent type to avoid order of elaboration issues. This
2768 can lose some code efficiency, but there is no alternative. */
2774 /* If we are pointing to an incomplete type whose completion is an
2775 unconstrained array, make a fat pointer type instead of a pointer
2776 to VOID. The two types in our fields will be pointers to VOID and
2777 will be replaced in update_pointer_to. Similiarly, if the type
2778 itself is a dummy type or an unconstrained array. Also make
2779 a dummy TYPE_OBJECT_RECORD_TYPE in case we have any thin
2780 pointers to it. */
2801 {
2802 tree gnu_old
2806 tree fields;
2808 /* Show the dummy we get will be a fat pointer. */
2811 /* If the call above got something that has a pointer, that
2812 pointer is our type. This could have happened either
2813 because the type was elaborated or because somebody
2814 else executed the code below. */
2817 {
2823 fields
2825 create_field_decl
2830 ptr_void_type_node,
2833 /* Make sure we can place this into a register. */
2844 }
2845 }
2847 /* If we already know what the full type is, use it. */
2852 /* Get the type of the thing we are to point to and build a pointer
2853 to it. If it is a reference to an incomplete or private type with a
2854 full view that is a record, make a dummy type node and get the
2855 actual type later when we have verified it is safe. */
2861 {
2864 }
2866 /* Likewise if we are pointing to a record or array and we are to defer
2867 elaborating incomplete types. We do this since this access type
2868 may be the full view of some private type. Note that the
2869 unconstrained array case is handled above. */
2877 {
2880 }
2882 {
2885 }
2886 else
2889 /* It is possible that the above call to gnat_to_gnu_type resolved our
2890 type. If so, just return it. */
2892 {
2895 }
2897 /* If we have a GCC type for the designated type, possibly
2898 modify it if we are pointing only to constant objects and then
2899 make a pointer to it. Don't do this for unconstrained arrays. */
2901 {
2904 gnu_desig_type
2910 }
2912 /* If we are not defining this object and we made a dummy pointer,
2913 save our current definition, evaluate the actual type, and replace
2914 the tentative type we made with the actual one. If we are to defer
2915 actually looking up the actual type, make an entry in the
2916 deferred list. */
2919 {
2920 tree gnu_old_type
2926 gnu_type
2927 = build_pointer_type
2928 (TYPE_OBJECT_RECORD_TYPE
2933 debug_info_p);
2940 else
2941 {
2949 }
2950 }
2951 }
2957 else
2958 /* The runtime representation is the equivalent type. */
2972 /* We treat this as identical to its base type; any constraint is
2973 meaningful only to the front end.
2975 The designated type must be elaborated as well, if it does
2976 not have its own freeze node. Designated (sub)types created
2977 for constrained components of records with discriminants are
2978 not frozen by the front end and thus not elaborated by gigi,
2979 because their use may appear before the base type is frozen,
2980 and because it is not clear that they are needed anywhere in
2981 Gigi. With the current model, there is no correct place where
2982 they could be elaborated. */
2989 {
2990 /* If we are not defining this entity, and we have incomplete
2991 entities being processed above us, make a dummy type and
2992 elaborate it later. */
2994 {
2997 tree gnu_ptr_type
2998 = build_pointer_type
3005 }
3006 else
3009 }
3014 /* Subprogram Entities
3016 The following access functions are defined for subprograms (functions
3017 or procedures):
3019 First_Formal The first formal parameter.
3020 Is_Imported Indicates that the subprogram has appeared in
3021 an INTERFACE or IMPORT pragma. For now we
3022 assume that the external language is C.
3023 Is_Inlined True if the subprogram is to be inlined.
3025 In addition for function subprograms we have:
3027 Etype Return type of the function.
3029 Each parameter is first checked by calling must_pass_by_ref on its
3030 type to determine if it is passed by reference. For parameters which
3031 are copied in, if they are Ada IN OUT or OUT parameters, their return
3032 value becomes part of a record which becomes the return type of the
3033 function (C function - note that this applies only to Ada procedures
3034 so there is no Ada return type). Additional code to store back the
3035 parameters will be generated on the caller side. This transformation
3036 is done here, not in the front-end.
3038 The intended result of the transformation can be seen from the
3039 equivalent source rewritings that follow:
3041 struct temp {int a,b};
3042 procedure P (A,B: IN OUT ...) is temp P (int A,B) {
3043 .. ..
3044 end P; return {A,B};
3045 }
3046 procedure call
3048 {
3049 temp t;
3050 P(X,Y); t = P(X,Y);
3051 X = t.a , Y = t.b;
3052 }
3054 For subprogram types we need to perform mainly the same conversions to
3055 GCC form that are needed for procedures and function declarations. The
3056 only difference is that at the end, we make a type declaration instead
3057 of a function declaration. */
3062 {
3063 /* The first GCC parameter declaration (a PARM_DECL node). The
3064 PARM_DECL nodes are chained through the TREE_CHAIN field, so this
3065 actually is the head of this parameter list. */
3067 /* The type returned by a function. If the subprogram is a procedure
3068 this type should be void_type_node. */
3070 /* List of fields in return type of procedure with copy in copy out
3071 parameters. */
3073 /* Non-null for subprograms containing parameters passed by copy in
3074 copy out (Ada IN OUT or OUT parameters not passed by reference),
3075 in which case it is the list of nodes used to specify the values of
3076 the in out/out parameters that are returned as a record upon
3077 procedure return. The TREE_PURPOSE of an element of this list is
3078 a field of the record and the TREE_VALUE is the PARM_DECL
3079 corresponding to that field. This list will be saved in the
3080 TYPE_CI_CO_LIST field of the FUNCTION_TYPE node we create. */
3082 Entity_Id gnat_param;
3085 int extern_flag
3096 /* A parameter may refer to this type, so defer completion
3097 of any incomplete types. */
3100 /* If the subprogram has an alias, it is probably inherited, so
3101 we can use the original one. If the original "subprogram"
3102 is actually an enumeration literal, it may be the first use
3103 of its type, so we must elaborate that type now. */
3105 {
3112 /* Elaborate any Itypes in the parameters of this entity. */
3120 }
3125 /* If this function returns by reference, make the actual
3126 return type of this function the pointer and mark the decl. */
3128 {
3132 }
3134 /* If we are supposed to return an unconstrained array,
3135 actually return a fat pointer and make a note of that. Return
3136 a pointer to an unconstrained record of variable size. */
3138 {
3141 }
3143 /* If the type requires a transient scope, the result is allocated
3144 on the secondary stack, so the result type of the function is
3145 just a pointer. */
3147 {
3150 }
3152 /* If the type is a padded type and the underlying type would not
3153 be passed by reference or this function has a foreign convention,
3154 return the underlying type. */
3162 /* Look at all our parameters and get the type of
3163 each. While doing this, build a copy-out structure if
3164 we need one. */
3169 {
3179 /* See if a Mechanism was supplied that forced this
3180 parameter to be passed one way or another. */
3184 ;
3192 {
3198 else
3200 }
3201 else
3204 /* If this is either a foreign function or if the
3205 underlying type won't be passed by refererence, strip off
3206 possible padding type. */
3214 /* If this is an IN parameter it is read-only, so make a variant
3215 of the type that is read-only.
3217 ??? However, if this is an unconstrained array, that type can
3218 be very complex. So skip it for now. Likewise for any other
3219 self-referential type. */
3225 gnu_param_type
3230 /* For foreign conventions, pass arrays as a pointer to the
3231 underlying type. First check for unconstrained array and get
3232 the underlying array. Then get the component type and build
3233 a pointer to it. */
3236 gnu_param_type
3241 gnu_param_type
3242 = build_pointer_type
3245 gnat_entity));
3248 && ! req_by_copy
3250 {
3251 /* Strip off any multi-dimensional entries, then strip
3252 off the last array to get the component type. */
3261 gnu_param_type
3267 }
3269 /* Fat pointers are passed as thin pointers for foreign
3270 conventions. */
3273 gnu_param_type
3277 /* If we must pass or were requested to pass by reference, do so.
3278 If we were requested to pass by copy, do so.
3279 Otherwise, for foreign conventions, pass all in out parameters
3280 or aggregates by reference. For COBOL and Fortran, pass
3281 all integer and FP types that way too. For Convention Ada,
3282 use the standard Ada default. */
3284 || (! req_by_copy
3294 /* For convention Ada, see if we pass by reference
3295 by default. */
3298 {
3301 }
3309 /* If this is an OUT parameter that isn't passed by reference
3310 and isn't a pointer or aggregate, we don't make a PARM_DECL
3311 for it. Instead, it will be a VAR_DECL created when we process
3312 the procedure. For the special parameter of Valued_Procedure,
3313 never pass it in. */
3316 || (! by_descr_p
3320 else
3321 {
3323 gnu_param
3324 = create_param_decl
3326 by_ref_p || by_component_ptr_p
3338 /* If a parameter is a pointer, this function may modify
3339 memory through it and thus shouldn't be considered
3340 a pure function. Also, the memory may be modified
3341 between two calls, so they can't be CSE'ed. The latter
3342 case also handles by-ref parameters. */
3346 }
3349 {
3351 {
3358 }
3366 gnu_return_list);
3367 }
3368 }
3370 /* Do not compute record for out parameters if subprogram is
3371 stubbed since structures are incomplete for the back-end. */
3377 /* If we have a CICO list but it has only one entry, we convert
3378 this function into a function that simply returns that one
3379 object. */
3384 {
3394 }
3396 /* Both lists ware built in reverse. */
3400 gnu_type
3403 returns_by_ref,
3406 /* ??? For now, don't consider nested functions pure. */
3410 gnu_type
3416 /* Top-level or external functions need to have an assembler name.
3417 This is passed to create_subprog_decl through the ext_name argument.
3418 For Pragma Interface subprograms with no Pragma Interface_Name, the
3419 simple name already in entity_name is correct, and this is what is
3420 gotten when ext_name is NULL. If Interface_Name is specified, then
3421 the name is extracted from the N_String_Literal node containing the
3422 string specified in the Pragma. If there is no Pragma Interface,
3423 then the Ada fully qualified name is created. */
3427 {
3430 /* If there wasn't a specified Interface_Name, use this for the
3431 main name of the entity. This will cause GCC to allow
3432 qualification of a nested subprogram with a unique ID. We
3433 need this in case there is an overloaded subprogram somewhere
3434 up the scope chain.
3436 ??? This may be a kludge. */
3439 }
3443 /* If we are defining the subprogram and it has an Address clause
3444 we must get the address expression from the saved GCC tree for the
3445 subprogram if it has a Freeze_Node. Otherwise, we elaborate
3446 the address expression here since the front-end has guaranteed
3447 in that case that the elaboration has no effects. If there is
3448 an Address clause and we are not defining the object, just
3449 make it a constant. */
3451 {
3455 gnu_address
3466 gnu_decl
3471 }
3476 debug_info_p);
3477 else
3478 {
3485 }
3486 }
3497 /* If this type does not have a full view in the unit we are
3498 compiling, then just get the type from its Etype. */
3500 {
3501 /* If this is an incomplete type with no full view, it must
3502 be a Taft Amendement type, so just return a dummy type. */
3509 else
3510 {
3514 }
3517 }
3519 /* Otherwise, if we are not defining the type now, get the
3520 type from the full view. But always get the type from the full
3521 view for define on use types, since otherwise we won't see them! */
3528 {
3533 }
3535 /* For incomplete types, make a dummy type entry which will be
3536 replaced later. */
3539 /* Save this type as the full declaration's type so we can do any needed
3540 updates when we see it. */
3544 debug_info_p);
3548 /* Simple class_wide types are always viewed as their root_type
3549 by Gigi unless an Equivalent_Type is specified. */
3553 else
3565 else
3577 /* Nothing at all to do here, so just return an ERROR_MARK and claim
3578 we've already saved it, so we don't try to. */
3585 }
3587 /* If we had a case where we evaluated another type and it might have
3588 defined this one, handle it here. */
3590 {
3593 }
3595 /* If we are processing a type and there is either no decl for it or
3596 we just made one, do some common processing for the type, such as
3597 handling alignment and possible padding. */
3600 {
3607 /* ??? Don't set the size for a String_Literal since it is either
3608 confirming or we don't handle it properly (if the low bound is
3609 non-constant). */
3614 /* If a size was specified, see if we can make a new type of that size
3615 by rearranging the type, for example from a fat to a thin pointer. */
3617 {
3618 gnu_type
3625 }
3627 /* If the alignment hasn't already been processed and this is
3628 not an unconstrained array, see if an alignment is specified.
3629 If not, we pick a default alignment for atomic objects. */
3631 ;
3645 /* See if we need to pad the type. If we did, and made a record,
3646 the name of the new type may be changed. So get it back for
3647 us when we make the new TYPE_DECL below. */
3652 {
3656 }
3660 /* If we are at global level, GCC will have applied variable_size to
3661 the type, but that won't have done anything. So, if it's not
3662 a constant or self-referential, call elaborate_expression_1 to
3663 make a variable for the size rather than calculating it each time.
3664 Handle both the RM size and the actual size. */
3669 {
3678 else
3679 {
3686 /* ??? For now, store the size as a multiple of the alignment
3687 in bytes so that we can see the alignment from the tree. */
3689 = build_binary_op
3691 elaborate_expression_1
3707 }
3708 }
3710 /* If this is a record type or subtype, call elaborate_expression_1 on
3711 any field position. Do this for both global and local types.
3712 Skip any fields that we haven't made trees for to avoid problems with
3713 class wide types. */
3718 {
3721 /* ??? Unfortunately, GCC needs to be able to prove the
3722 alignment of this offset and if it's a variable, it can't.
3723 In GCC 3.2, we'll use DECL_OFFSET_ALIGN in some way, but
3724 right now, we have to put in an explicit multiply and
3725 divide by that value. */
3729 = build_binary_op
3731 elaborate_expression_1
3740 }
3744 | (TYPE_QUAL_VOLATILE
3754 {
3758 debug_info_p);
3759 }
3760 else
3762 }
3765 {
3768 /* Back-annotate the Alignment of the type if not already in the
3769 tree. Likewise for sizes. */
3775 {
3776 /* If the size is self-referential, we annotate the maximum
3777 value of that size. */
3784 }
3788 }
3797 /* If this decl is really indirect, adjust it. */
3801 /* If we haven't already, associate the ..._DECL node that we just made with
3802 the input GNAT entity node. */
3806 /* If this is an enumeral or floating-point type, we were not able to set
3807 the bounds since they refer to the type. These bounds are always static.
3809 For enumeration types, also write debugging information and declare the
3810 enumeration literal table, if needed. */
3814 {
3817 /* If this is a padded type, we need to use the underlying type. */
3822 /* If this is a floating point type and we haven't set a floating
3823 point type yet, use this in the evaluation of the bounds. */
3833 {
3836 /* Since this has both a typedef and a tag, avoid outputting
3837 the name twice. */
3840 }
3841 }
3843 /* If we deferred processing of incomplete types, re-enable it. If there
3844 were no other disables and we have some to process, do so. */
3847 {
3853 {
3860 }
3861 }
3863 /* If we are not defining this type, see if it's in the incomplete list.
3864 If so, handle that list entry now. */
3866 {
3871 {
3875 }
3876 }
3879 force_global--;
3888 }
3889 \f
3890 /* Given GNAT_ENTITY, elaborate all expressions that are required to
3891 be elaborated at the point of its definition, but do nothing else. */
3893 void
3895 Entity_Id gnat_entity;
3896 {
3898 {
3905 {
3909 /* ??? Tests for avoiding static constaint error expression
3910 is needed until the front stops generating bogus conversions
3911 on bounds of real types. */
3920 }
3923 {
3927 /* If this is a record extension, go a level further to find the
3928 record definition. */
3931 }
3941 {
3942 Node_Id gnat_discriminant_expr;
3943 Entity_Id gnat_field;
3946 gnat_discriminant_expr
3951 /* ??? For now, ignore access discriminants. */
3954 gnat_entity,
3956 }
3959 }
3960 }
3961 \f
3962 /* Mark GNAT_ENTITY as going out of scope at this point. Recursively mark
3963 any entities on its entity chain similarly. */
3965 void
3967 Entity_Id gnat_entity;
3968 {
3969 Entity_Id gnat_sub_entity;
3972 /* If this has an entity list, process all in the list. */
3989 /* Now clear this if it has been defined, but only do so if it isn't
3990 a subprogram or parameter. We could refine this, but it isn't
3991 worth it. If this is statically allocated, it is supposed to
3992 hang around out of cope. */
3995 {
3998 }
3999 }
4000 \f
4001 /* Return a TREE_LIST describing the substitutions needed to reflect
4002 discriminant substitutions from GNAT_SUBTYPE to GNAT_TYPE and add
4003 them to GNU_LIST. If GNAT_TYPE is not specified, use the base type
4004 of GNAT_SUBTYPE. The substitions can be in any order. TREE_PURPOSE
4005 gives the tree for the discriminant and TREE_VALUES is the replacement
4006 value. They are in the form of operands to substitute_in_expr.
4007 DEFINITION is as in gnat_to_gnu_entity. */
4009 static tree
4011 Entity_Id gnat_subtype;
4012 Entity_Id gnat_type;
4013 tree gnu_list;
4015 {
4016 Entity_Id gnat_discrim;
4017 Node_Id gnat_value;
4028 /* Ignore access discriminants. */
4031 elaborate_expression
4035 gnu_list);
4038 }
4039 \f
4040 /* For the following two functions: for each GNAT entity, the GCC
4041 tree node used as a dummy for that entity, if any. */
4045 /* Initialize the above table. */
4047 void
4049 {
4050 Node_Id gnat_node;
4059 }
4061 /* Make a dummy type corresponding to GNAT_TYPE. */
4063 tree
4065 Entity_Id gnat_type;
4066 {
4067 Entity_Id gnat_underlying;
4068 tree gnu_type;
4070 /* Find a full type for GNAT_TYPE, taking into account any class wide
4071 types. */
4081 ;
4083 /* If it there already a dummy type, use that one. Else make one. */
4087 /* If this is a record, make this a RECORD_TYPE or UNION_TYPE; else make
4088 it a VOID_TYPE. */
4092 else
4104 }
4105 \f
4106 /* Return 1 if the size represented by GNU_SIZE can be handled by an
4107 allocation. If STATIC_P is non-zero, consider only what can be
4108 done with a static allocation. */
4110 static int
4112 tree gnu_size;
4114 {
4115 /* If this is not a static allocation, the only case we want to forbid
4116 is an overflowing size. That will be converted into a raise a
4117 Storage_Error. */
4122 /* Otherwise, we need to deal with both variable sizes and constant
4123 sizes that won't fit in a host int. */
4125 }
4126 \f
4127 /* Return a list of attributes for GNAT_ENTITY, if any. */
4131 Entity_Id gnat_entity;
4132 {
4134 Node_Id gnat_temp;
4139 {
4149 {
4151 (gnat_to_gnu
4158 (gnat_to_gnu
4159 (Expression
4162 }
4165 {
4184 }
4191 attr->error_point
4195 }
4198 }
4199 \f
4200 /* Get the unpadded version of a GNAT type. */
4202 tree
4204 Entity_Id gnat_entity;
4205 {
4212 }
4213 \f
4214 /* Called when we need to protect a variable object using a save_expr. */
4216 tree
4218 tree gnu_operand;
4219 Node_Id gnat_node;
4220 {
4226 /* If we will be generating code, make sure we are at the proper
4227 line number. */
4235 else
4237 }
4238 \f
4239 /* Given a GNAT tree GNAT_EXPR, for an expression which is a value within a
4240 type definition (either a bound or a discriminant value) for GNAT_ENTITY,
4241 return the GCC tree to use for that expression. GNU_NAME is the
4242 qualification to use if an external name is appropriate and DEFINITION is
4243 nonzero if this is a definition of GNAT_ENTITY. If NEED_VALUE is nonzero,
4244 we need a result. Otherwise, we are just elaborating this for
4245 side-effects. If NEED_DEBUG is nonzero we need the symbol for debugging
4246 purposes even if it isn't needed for code generation. */
4248 static tree
4251 Node_Id gnat_expr;
4252 Entity_Id gnat_entity;
4253 tree gnu_name;
4257 {
4258 tree gnu_expr;
4260 /* If we already elaborated this expression (e.g., it was involved
4261 in the definition of a private type), use the old value. */
4265 /* If we don't need a value and this is static or a discriment, we
4266 don't need to do anything. */
4273 /* Otherwise, convert this tree to its GCC equivalant. */
4274 gnu_expr
4278 /* Save the expression in case we try to elaborate this entity again.
4279 Since this is not a DECL, don't check it. If this is a constant,
4280 don't save it since GNAT_EXPR might be used more than once. Also,
4281 don't save if it's a discriminant. */
4286 }
4288 /* Similar, but take a GNU expression. */
4290 static tree
4292 need_debug)
4293 Node_Id gnat_expr;
4294 Entity_Id gnat_entity;
4295 tree gnu_expr;
4296 tree gnu_name;
4299 {
4301 /* Strip any conversions to see if the expression is a readonly variable.
4302 ??? This really should remain readonly, but we have to think about
4303 the typing of the tree here. */
4308 /* In most cases, we won't see a naked FIELD_DECL here because a
4309 discriminant reference will have been replaced with a COMPONENT_REF
4310 when the type is being elaborated. However, there are some cases
4311 involving child types where we will. So convert it to a COMPONENT_REF
4312 here. We have to hope it will be at the highest level of the
4313 expression in these cases. */
4317 gnu_expr);
4319 /* If GNU_EXPR is neither a placeholder nor a constant, nor a variable
4320 that is a constant, make a variable that is initialized to contain the
4321 bound when the package containing the definition is elaborated. If
4322 this entity is defined at top level and a bound or discriminant value
4323 isn't a constant or a reference to a discriminant, replace the bound
4324 by the variable; otherwise use a SAVE_EXPR if needed. Note that we
4325 rely here on the fact that an expression cannot contain both the
4326 discriminant and some other variable. */
4333 /* If this is a static expression or contains a discriminant, we don't
4334 need the variable for debugging (and can't elaborate anyway if a
4335 discriminant). */
4341 /* Now create the variable if we need it. */
4343 {
4345 gnu_decl
4350 }
4352 /* We only need to use this variable if we are in global context since GCC
4353 can do the right thing in the local case. */
4358 else
4360 }
4361 \f
4362 /* Create a record type that contains a field of TYPE with a starting bit
4363 position so that it is aligned to ALIGN bits and is SIZE bytes long. */
4365 tree
4367 tree type;
4369 tree size;
4370 {
4375 place));
4384 /* The bit position is obtained by "and"ing the alignment minus 1
4385 with the two's complement of the address and multiplying
4386 by the number of bits per unit. Do all this in sizetype. */
4392 size_addr_place),
4395 bitsize_unit_node);
4406 bitsize_unit_node),
4412 }
4413 \f
4414 /* TYPE is a RECORD_TYPE with BLKmode that's being used as the field
4415 type of a packed record. See if we can rewrite it as a record that has
4416 a non-BLKmode type, which we can pack tighter. If so, return the
4417 new type. If not, return the original type. */
4419 static tree
4421 tree type;
4422 {
4425 tree old_field;
4427 /* Copy the name and flags from the old type to that of the new and set
4428 the alignment to try for an integral type. */
4438 /* Now copy the fields, keeping the position and size. */
4441 {
4442 tree new_field
4455 }
4459 }
4460 \f
4461 /* Ensure that TYPE has SIZE and ALIGN. Make and return a new padded type
4462 if needed. We have already verified that SIZE and TYPE are large enough.
4464 GNAT_ENTITY and NAME_TRAILER are used to name the resulting record and
4465 to issue a warning.
4467 IS_USER_TYPE is nonzero if we must be sure we complete the original type.
4469 DEFINITION is nonzero if this type is being defined.
4471 SAME_RM_SIZE is nonzero if the RM_Size of the resulting type is to be
4472 set to its TYPE_SIZE; otherwise, it's set to the RM_Size of the original
4473 type. */
4475 static tree
4478 tree type;
4479 tree size;
4481 Entity_Id gnat_entity;
4486 {
4488 tree record;
4489 tree field;
4491 /* If TYPE is a padded type, see if it agrees with any size and alignment
4492 we were given. If so, return the original type. Otherwise, strip
4493 off the padding, since we will either be returning the inner type
4494 or repadding it. If no size or alignment is specified, use that of
4495 the original padded type. */
4498 {
4515 }
4517 /* If the size is either not being changed or is being made smaller (which
4518 is not done here (and is only valid for bitfields anyway), show the size
4519 isn't changing. Likewise, clear the alignment if it isn't being
4520 changed. Then return if we aren't doing anything. */
4534 /* We used to modify the record in place in some cases, but that could
4535 generate incorrect debugging information. So make a new record
4536 type and name. */
4542 /* If we were making a type, complete the original type and give it a
4543 name. */
4551 /* If we are changing the alignment and the input type is a record with
4552 BLKmode and a small constant size, try to make a form that has an
4553 integral mode. That might allow this record to have an integral mode,
4554 which will be much more efficient. There is no point in doing this if a
4555 size is specified unless it is also smaller than the biggest alignment
4556 and it is incorrect to do this if the size of the original type is not a
4557 multiple of the alignment. */
4577 bitsize_unit_node));
4584 /* Keep the RM_Size of the padded record as that of the old record
4585 if requested. */
4588 /* Unless debugging information isn't being written for the input type,
4589 write a record that shows what we are a subtype of and also make a
4590 variable that indicates our size, if variable. */
4595 {
4614 }
4622 /* If the size was widened explicitly, maybe give a warning. */
4628 {
4641 /* Generate message only for entities that come from source, since
4642 if we have an entity created by expansion, the message will be
4643 generated for some other corresponding source entity. */
4646 gnat_entity,
4653 }
4656 }
4657 \f
4658 /* Given a GNU tree and a GNAT list of choices, generate an expression to test
4659 the value passed against the list of choices. */
4661 tree
4663 tree operand;
4664 Node_Id choices;
4665 {
4666 Node_Id choice;
4667 Node_Id gnat_temp;
4672 {
4674 {
4679 /* There's no good type to use here, so we might as well use
4680 integer_type_node. */
4681 this_test
4695 this_test
4705 /* This represents either a subtype range, an enumeration
4706 literal, or a constant Ekind says which. If an enumeration
4707 literal or constant, fall through to the next case. */
4710 {
4716 this_test
4723 }
4724 /* ... fall through ... */
4729 single);
4738 }
4742 }
4745 }
4746 \f
4747 /* Return a GCC tree for a field corresponding to GNAT_FIELD to be
4748 placed in GNU_RECORD_TYPE.
4750 PACKED is 1 if the enclosing record is packed and -1 if the enclosing
4751 record has a Component_Alignment of Storage_Unit.
4753 DEFINITION is nonzero if this field is for a record being defined. */
4755 static tree
4757 Entity_Id gnat_field;
4758 tree gnu_record_type;
4761 {
4767 tree gnu_field;
4768 int needs_strict_alignment
4772 /* If this field requires strict alignment pretend it isn't packed. */
4776 /* For packed records, this is one of the few occasions on which we use
4777 the official RM size for discrete or fixed-point components, instead
4778 of the normal GNAT size stored in Esize. See description in Einfo:
4779 "Handling of Type'Size Values" for further details. */
4789 /* If the field's type is a left-justified modular type, make the field
4790 the type of the inner object unless it is aliases. We don't need
4791 the the wrapper here and it can prevent packing. */
4796 /* If we are packing this record or we have a specified size that's
4797 smaller than that of the field type and the field type is also a record
4798 that's BLKmode and with a small constant size, see if we can get a
4799 better form of the type that allows more packing. If we can, show
4800 a size was specified for it if there wasn't one so we know to
4801 make this a bitfield and avoid making things wider. */
4806 && (packed
4809 {
4814 }
4817 {
4822 /* Ensure the position does not overlap with the parent subtype,
4823 if there is one. */
4825 {
4826 tree gnu_parent
4832 {
4833 post_error_ne_tree
4837 }
4838 }
4840 /* If this field needs strict alignment, ensure the record is
4841 sufficiently aligned and that that position and size are
4842 consistent with the alignment. */
4844 {
4851 /* If Atomic, the size must match exactly and if aliased, the size
4852 must not be less than the rounded size. */
4855 {
4856 post_error_ne_tree
4862 }
4867 {
4868 post_error_ne_tree
4871 gnu_min_size);
4873 }
4878 {
4880 post_error_ne_num
4886 post_error_ne_num
4892 post_error_ne_num
4896 else
4900 }
4902 /* If an error set the size to zero, show we have no position
4903 either. */
4906 }
4913 bitsize_unit_node))))
4914 {
4915 /* Try to see if we can make this a packable type. If we
4916 can, it's OK. */
4921 {
4926 }
4927 }
4928 }
4930 /* If the record has rep clauses and this is the tag field, make a rep
4931 clause for it as well. */
4934 {
4937 }
4939 /* We need to make the size the maximum for the type if it is
4940 self-referential and an unconstrained type. In that case, we can't
4941 pack the field since we can't make a copy to align it. */
4947 {
4950 }
4952 /* If no size is specified (or if there was an error), don't specify a
4953 position. */
4956 else
4957 {
4958 /* Unless this field is aliased, we can remove any left-justified
4959 modular type since it's only needed in the unchecked conversion
4960 case, which doesn't apply here. */
4966 gnu_field_type
4971 }
4989 }
4990 \f
4991 /* Return a GCC tree for a record type given a GNAT Component_List and a chain
4992 of GCC trees for fields that are in the record and have already been
4993 processed. When called from gnat_to_gnu_entity during the processing of a
4994 record type definition, the GCC nodes for the discriminants will be on
4995 the chain. The other calls to this function are recursive calls from
4996 itself for the Component_List of a variant and the chain is empty.
4998 PACKED is 1 if this is for a record with "pragma pack" and -1 is this is
4999 for a record type with "pragma component_alignment (storage_unit)".
5001 FINISH_RECORD is nonzero if this call will supply all of the remaining
5002 fields of the record.
5004 P_GNU_REP_LIST, if nonzero, is a pointer to a list to which each field
5005 with a rep clause is to be added. If it is nonzero, that is all that
5006 should be done with such fields.
5008 CANCEL_ALIGNMENT, if nonzero, means the alignment should be zeroed
5009 before laying out the record. This means the alignment only serves
5010 to force fields to be bitfields, but not require the record to be
5011 that aligned. This is used for variants.
5013 ALL_REP, if nonzero, means that a rep clause was found for all the
5014 fields. This simplifies the logic since we know we're not in the mixed
5015 case.
5017 The processing of the component list fills in the chain with all of the
5018 fields of the record and then the record type is finished. */
5020 static void
5023 tree gnu_record_type;
5024 Node_Id component_list;
5025 tree gnu_field_list;
5031 {
5032 Node_Id component_decl;
5033 Entity_Id gnat_field;
5034 Node_Id variant_part;
5035 Node_Id variant;
5040 /* For each variable within each component declaration create a GCC field
5041 and add it to the list, skipping any pragmas in the list. */
5047 {
5052 else
5053 {
5057 /* If this is the _Tag field, put it before any discriminants,
5058 instead of after them as is the case for all other fields. */
5061 else
5062 {
5065 }
5066 }
5069 }
5071 /* At the end of the component list there may be a variant part. */
5074 /* If this is an unchecked union, each variant must have exactly one
5075 component, each of which becomes one component of this union. */
5080 {
5081 component_decl
5085 definition);
5089 }
5091 /* We create a QUAL_UNION_TYPE for the variant part since the variants are
5092 mutually exclusive and should go in the same memory. To do this we need
5093 to treat each variant as a record whose elements are created from the
5094 component list for the variant. So here we create the records from the
5095 lists for the variants and put them all into the QUAL_UNION_TYPE. */
5097 {
5099 Node_Id variant;
5101 tree gnu_union_field;
5104 tree gnu_var_name
5105 = concat_id_with_name
5119 {
5121 tree gnu_inner_name;
5122 tree gnu_qual;
5130 /* Set the alignment of the inner type in case we need to make
5131 inner objects into bitfields, but then clear it out
5132 so the record actually gets only the alignment required. */
5149 }
5151 /* We can delete any empty variants from the end. This may leave none
5152 left. Note we cannot delete variants from anywhere else. */
5157 /* Only make the QUAL_UNION_TYPE if there are any non-empty variants. */
5159 {
5163 gnu_union_field
5165 packed,
5172 }
5173 }
5175 /* Scan GNU_FIELD_LIST and see if any fields have rep clauses. If they
5176 do, pull them out and put them into GNU_OUR_REP_LIST. We have to do this
5177 in a separate pass since we want to handle the discriminants but can't
5178 play with them until we've used them in debugging data above.
5180 ??? Note: if we then reorder them, debugging information will be wrong,
5181 but there's nothing that can be done about this at the moment. */
5184 {
5186 {
5191 else
5197 }
5198 else
5199 {
5202 }
5203 }
5205 /* If we have any items in our rep'ed field list, it is not the case that all
5206 the fields in the record have rep clauses, and P_REP_LIST is nonzero,
5207 set it and ignore the items. Otherwise, sort the fields by bit position
5208 and put them into their own record if we have any fields without
5209 rep clauses. */
5213 {
5214 tree gnu_rep_type
5220 /* Set DECL_SECTION_NAME to increasing integers so we have a
5221 stable sort. */
5224 {
5227 }
5231 /* Put the fields in the list in order of increasing position, which
5232 means we start from the end. */
5235 {
5240 }
5243 {
5249 }
5250 else
5251 {
5254 }
5255 }
5262 }
5263 \f
5264 /* Called via qsort from the above. Returns -1, 1, depending on the
5265 bit positions and ordinals of the two fields. */
5267 static int
5271 {
5276 return
5281 else
5283 }
5284 \f
5285 /* Given GNU_SIZE, a GCC tree representing a size, return a Uint to be
5286 placed into an Esize, Component_Bit_Offset, or Component_Size value
5287 in the GNAT tree. */
5289 static Uint
5291 tree gnu_size;
5292 {
5294 TCode tcode;
5299 /* If we do not return inside this switch, TCODE will be set to the
5300 code to use for a Create_Node operand and LEN (set above) will be
5301 the number of recursive calls for us to make. */
5304 {
5309 /* This may have come from a conversion from some smaller type,
5310 so ensure this is in bitsizetype. */
5313 /* For negative values, use NEGATE_EXPR of the supplied value. */
5315 {
5316 /* The rediculous code below is to handle the case of the largest
5317 negative integer. */
5320 tree temp;
5323 {
5324 negative_size
5327 bitsize_one_node));
5329 }
5336 }
5343 /* This peculiar test is to make sure that the size fits in an int
5344 on machines where HOST_WIDE_INT is not "int". */
5347 else
5351 /* The only case we handle here is a simple discriminant reference. */
5359 else
5365 /* Now just list the operations we handle. */
5396 }
5398 /* Now get each of the operands that's relevant for this code. If any
5399 cannot be expressed as a repinfo node, say we can't. */
5404 {
5408 }
5411 }
5413 /* Given GNAT_ENTITY, a record type, and GNU_TYPE, its corresponding
5414 GCC type, set Component_Bit_Offset and Esize to the position and size
5415 used by Gigi. */
5417 static void
5419 Entity_Id gnat_entity;
5420 tree gnu_type;
5421 {
5422 tree gnu_list;
5423 tree gnu_entry;
5424 Entity_Id gnat_field;
5426 /* We operate by first making a list of all field and their positions
5427 (we can get the sizes easily at any time) by a recursive call
5428 and then update all the sizes into the tree. */
5431 BIGGEST_ALIGNMENT);
5440 gnu_list)))
5441 {
5442 Set_Component_Bit_Offset
5451 }
5452 }
5454 /* Scan all fields in GNU_TYPE and build entries where TREE_PURPOSE is the
5455 FIELD_DECL and TREE_VALUE a TREE_LIST with TREE_PURPOSE being the byte
5456 position and TREE_VALUE being a TREE_LIST with TREE_PURPOSE the value to be
5457 placed into DECL_OFFSET_ALIGN and TREE_VALUE the bit position. GNU_POS is
5458 to be added to the position, GNU_BITPOS to the bit position, OFFSET_ALIGN is
5459 the present value of DECL_OFFSET_ALIGN and GNU_LIST is a list of the entries
5460 so far. */
5462 static tree
5464 tree gnu_type;
5465 tree gnu_list;
5466 tree gnu_pos;
5467 tree gnu_bitpos;
5469 {
5470 tree gnu_field;
5475 {
5480 unsigned int our_offset_align
5483 gnu_result
5488 NULL_TREE),
5489 gnu_result);
5492 gnu_result
5495 our_offset_align);
5496 }
5499 }
5500 \f
5501 /* UINT_SIZE is a Uint giving the specified size for an object of GNU_TYPE
5502 corresponding to GNAT_OBJECT. If size is valid, return a tree corresponding
5503 to its value. Otherwise return 0. KIND is VAR_DECL is we are specifying
5504 the size for an object, TYPE_DECL for the size of a type, and FIELD_DECL
5505 for the size of a field. COMPONENT_P is true if we are being called
5506 to process the Component_Size of GNAT_OBJECT. This is used for error
5507 message handling and to indicate to use the object size of GNU_TYPE.
5508 ZERO_OK is nonzero if a size of zero is permitted; if ZERO_OK is zero,
5509 it means that a size of zero should be treated as an unspecified size. */
5511 static tree
5513 Uint uint_size;
5514 tree gnu_type;
5515 Entity_Id gnat_object;
5519 {
5520 Node_Id gnat_error_node;
5521 tree type_size
5523 tree size;
5538 else
5541 /* Don't give errors on packed array types; we'll be giving the error on
5542 the type itself soon enough. */
5546 /* Get the size as a tree. Return 0 if none was specified, either because
5547 Esize was not Present or if the specified size was zero. Give an error
5548 if a size was specified, but cannot be represented as in sizetype. If
5549 the size is negative, it was a back-annotation of a variable size and
5550 should be treated as not specified. */
5556 {
5560 else
5564 }
5566 /* Ignore a negative size since that corresponds to our back-annotation.
5567 Also ignore a zero size unless a size clause exists. */
5571 /* The size of objects is always a multiple of a byte. */
5574 bitsize_unit_node)))
5575 {
5579 else
5583 }
5585 /* If this is an integral type, the front-end has verified the size, so we
5586 need not do it here (which would entail checking against the bounds).
5587 However, if this is an aliased object, it may not be smaller than the
5588 type of the object. */
5593 /* If the object is a record that contains a template, add the size of
5594 the template to the specified size. */
5599 /* If the size of the object is a constant, the new size must not be
5600 smaller. */
5604 {
5606 post_error_ne_tree
5609 else
5616 post_error_ne_tree_2
5626 }
5629 }
5630 \f
5631 /* Similarly, but both validate and process a value of RM_Size. This
5632 routine is only called for types. */
5634 static void
5636 Uint uint_size;
5637 tree gnu_type;
5638 Entity_Id gnat_entity;
5639 {
5640 /* Only give an error if a Value_Size clause was explicitly given.
5641 Otherwise, we'd be duplicating an error on the Size clause. */
5642 Node_Id gnat_attr_node
5645 tree size;
5647 /* Get the size as a tree. Do nothing if none was specified, either
5648 because RM_Size was not Present or if the specified size was zero.
5649 Give an error if a size was specified, but cannot be represented as
5650 in sizetype. */
5656 {
5659 gnat_entity);
5662 }
5664 /* Ignore a negative size since that corresponds to our back-annotation.
5665 Also ignore a zero size unless a size clause exists, a Value_Size
5666 clause exists, or this is an integer type, in which case the
5667 front end will have always set it. */
5674 /* If the old size is self-referential, get the maximum size. */
5679 /* If the size of the object is a constant, the new size must not be
5680 smaller (the front end checks this for scalar types). */
5685 {
5687 post_error_ne_tree
5692 }
5694 /* Otherwise, set the RM_Size. */
5705 }
5706 \f
5707 /* Given a type TYPE, return a new type whose size is appropriate for SIZE.
5708 If TYPE is the best type, return it. Otherwise, make a new type. We
5709 only support new integral and pointer types. BIASED_P is nonzero if
5710 we are making a biased type. */
5712 static tree
5714 tree type;
5715 tree size_tree;
5717 {
5718 tree new_type;
5721 /* If size indicates an error, just return TYPE to avoid propagating the
5722 error. Likewise if it's too large to represent. */
5728 {
5731 /* Only do something if the type is not already the proper size and is
5732 not a packed array type. */
5757 /* Do something if this is a fat pointer, in which case we
5758 may need to return the thin pointer. */
5760 return
5761 build_pointer_type
5766 /* Only do something if this is a thin pointer, in which case we
5767 may need to return the fat pointer. */
5769 return
5776 }
5779 }
5780 \f
5781 /* ALIGNMENT is a Uint giving the alignment specified for GNAT_ENTITY,
5782 a type or object whose present alignment is ALIGN. If this alignment is
5783 valid, return it. Otherwise, give an error and return ALIGN. */
5785 static unsigned int
5787 Uint alignment;
5788 Entity_Id gnat_entity;
5790 {
5794 #ifndef MAX_OFILE_ALIGNMENT
5795 #define MAX_OFILE_ALIGNMENT BIGGEST_ALIGNMENT
5796 #endif
5801 /* Don't worry about checking alignment if alignment was not specified
5802 by the source program and we already posted an error for this entity. */
5807 /* Within GCC, an alignment is an integer, so we must make sure a
5808 value is specified that fits in that range. Also, alignments of
5809 more than MAX_OFILE_ALIGNMENT can't be supported. */
5823 else
5827 }
5828 \f
5829 /* Verify that OBJECT, a type or decl, is something we can implement
5830 atomically. If not, give an error for GNAT_ENTITY. COMP_P is nonzero
5831 if we require atomic components. */
5833 static void
5835 tree object;
5836 Entity_Id gnat_entity;
5838 {
5840 Node_Id gnat_node;
5843 tree size;
5845 /* There are three case of what OBJECT can be. It can be a type, in which
5846 case we take the size, alignment and mode from the type. It can be a
5847 declaration that was indirect, in which case the relevant values are
5848 that of the type being pointed to, or it can be a normal declaration,
5849 in which case the values are of the decl. The code below assumes that
5850 OBJECT is either a type or a decl. */
5852 {
5856 }
5858 {
5862 }
5863 else
5864 {
5868 }
5870 /* Consider all floating-point types atomic and any types that that are
5871 represented by integers no wider than a machine word. */
5878 /* For the moment, also allow anything that has an alignment equal
5879 to its size and which is smaller than a word. */
5887 {
5895 }
5900 else
5903 }
5904 \f
5905 /* Given a type T, a FIELD_DECL F, and a replacement value R,
5906 return a new type with all size expressions that contain F
5907 updated by replacing F with R. This is identical to GCC's
5908 substitute_in_type except that it knows about TYPE_INDEX_TYPE.
5909 If F is NULL_TREE, always make a new RECORD_TYPE, even if nothing has
5910 changed. */
5912 tree
5915 {
5917 tree tem;
5920 {
5929 {
5941 }
5952 {
5966 }
5982 /* Don't know how to do these yet. */
5986 {
6000 }
6005 {
6006 tree field;
6007 int changed_field
6014 /* Start out with no fields, make new fields, and chain them
6015 in. If we haven't actually changed the type of any field,
6016 discard everything we've done and return the old type. */
6023 {
6034 /* If this is an internal field and the type of this field is
6035 a UNION_TYPE or RECORD_TYPE with no elements, ignore it. If
6036 the type just has one element, treat that as the field.
6037 But don't do this if we are processing a QUAL_UNION_TYPE. */
6042 {
6047 {
6048 tree next_new_field
6051 /* Make sure omitting the union doesn't change
6052 the layout. */
6055 }
6056 }
6063 /* If the size of the old field was set at a constant,
6064 propagate the size in case the type's size was variable.
6065 (This occurs in the case of a variant or discriminated
6066 record with a default size used as a field of another
6067 record.) */
6076 {
6082 /* Do the substitution inside the qualifier and if we find
6083 that this field will not be present, omit it. */
6088 }
6092 else
6097 /* If this is a qualified type and this field will always be
6098 present, we are done. */
6102 }
6104 /* If this used to be a qualified union type, but we now know what
6105 field will be present, make this a normal union. */
6118 /* If the size was originally a constant use it. */
6121 {
6125 }
6128 }
6132 }
6133 }
6134 \f
6135 /* Return the "RM size" of GNU_TYPE. This is the actual number of bits
6136 needed to represent the object. */
6138 tree
6140 tree gnu_type;
6141 {
6142 /* For integer types, this is the precision. For record types, we store
6143 the size explicitly. For other types, this is just the size. */
6149 /* Return the rm_size of the actual data plus the size of the template. */
6150 return
6160 else
6162 }
6163 \f
6164 /* Return an identifier representing the external name to be used for
6165 GNAT_ENTITY. If SUFFIX is specified, the name is followed by "___"
6166 and the specified suffix. */
6168 tree
6170 Entity_Id gnat_entity;
6172 {
6180 }
6182 /* Return the name to be used for GNAT_ENTITY. If a type, create a
6183 fully-qualified name, possibly with type information encoding.
6184 Otherwise, return the name. */
6186 tree
6188 Entity_Id gnat_entity;
6189 {
6192 }
6194 /* Given GNU_ID, an IDENTIFIER_NODE containing a name and SUFFIX, a
6195 string, return a new IDENTIFIER_NODE that is the concatenation of
6196 the name in GNU_ID and SUFFIX. */
6198 tree
6200 tree gnu_id;
6202 {
6211 }