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1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT COMPILER COMPONENTS --
4 -- --
5 -- F R E E Z E --
6 -- --
7 -- B o d y --
8 -- --
9 -- Copyright (C) 1992-2018, 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 3, 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 COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
20 -- --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
23 -- --
24 ------------------------------------------------------------------------------
74 -----------------------
75 -- Local Subprograms --
76 -----------------------
79 -- Typ is a type that is being frozen. If no size clause is given,
80 -- but a default Esize has been computed, then this default Esize is
81 -- adjusted up if necessary to be consistent with a given alignment,
82 -- but never to a value greater than Long_Long_Integer'Size. This
83 -- is used for all discrete types and for fixed-point types.
85 procedure Build_And_Analyze_Renamed_Body
89 -- Build body for a renaming declaration, insert in tree and analyze
92 -- Apply legality checks to address clauses for object declarations,
93 -- at the point the object is frozen. Also ensure any initialization is
94 -- performed only after the object has been frozen.
96 procedure Check_Component_Storage_Order
101 -- For an Encl_Type that has a Scalar_Storage_Order attribute definition
102 -- clause, verify that the component type has an explicit and compatible
103 -- attribute/aspect. For arrays, Comp is Empty; for records, it is the
104 -- entity of the component under consideration. For an Encl_Type that
105 -- does not have a Scalar_Storage_Order attribute definition clause,
106 -- verify that the component also does not have such a clause.
107 -- ADC is the attribute definition clause if present (or Empty). On return,
108 -- Comp_ADC_Present is set True if the component has a Scalar_Storage_Order
109 -- attribute definition clause.
112 -- As each entity is frozen, this routine is called to deal with the
113 -- setting of Debug_Info_Needed for the entity. This flag is set if
114 -- the entity comes from source, or if we are in Debug_Generated_Code
115 -- mode or if the -gnatdV debug flag is set. However, it never sets
116 -- the flag if Debug_Info_Off is set. This procedure also ensures that
117 -- subsidiary entities have the flag set as required.
120 -- When an expression function is frozen by a use of it, the expression
121 -- itself is frozen. Check that the expression does not include references
122 -- to deferred constants without completion. We report this at the freeze
123 -- point of the function, to provide a better error message.
124 --
125 -- In most cases the expression itself is frozen by the time the function
126 -- itself is frozen, because the formals will be frozen by then. However,
127 -- Attribute references to outer types are freeze points for those types;
128 -- this routine generates the required freeze nodes for them.
131 -- For a tagged derived type, create wrappers for inherited operations
132 -- that have a class-wide condition, so it can be properly rewritten if
133 -- it involves calls to other overriding primitives.
136 -- E is a base type. If E is tagged or has a component that is aliased
137 -- or tagged or contains something this is aliased or tagged, set
138 -- Strict_Alignment.
142 -- If E is a fixed-point or discrete type, then all the necessary work
143 -- to freeze it is completed except for possible setting of the flag
144 -- Is_Unsigned_Type, which is done by this procedure. The call has no
145 -- effect if the entity E is not a discrete or fixed-point type.
147 procedure Freeze_And_Append
151 -- Freezes Ent using Freeze_Entity, and appends the resulting list of
152 -- nodes to Result, modifying Result from No_List if necessary. N has
153 -- the same usage as in Freeze_Entity.
156 -- Freeze enumeration type. The Esize field is set as processing
157 -- proceeds (i.e. set by default when the type is declared and then
158 -- adjusted by rep clauses. What this procedure does is to make sure
159 -- that if a foreign convention is specified, and no specific size
160 -- is given, then the size must be at least Integer'Size.
163 -- If an object is frozen which has Is_Statically_Allocated set, then
164 -- all referenced types must also be marked with this flag. This routine
165 -- is in charge of meeting this requirement for the object entity E.
168 -- Perform freezing actions for a subprogram (create extra formals,
169 -- and set proper default mechanism values). Note that this routine
170 -- is not called for internal subprograms, for which neither of these
171 -- actions is needed (or desirable, we do not want for example to have
172 -- these extra formals present in initialization procedures, where they
173 -- would serve no purpose). In this call E is either a subprogram or
174 -- a subprogram type (i.e. an access to a subprogram).
177 -- True if T is not private and has no private components, or has a full
178 -- view. Used to determine whether the designated type of an access type
179 -- should be frozen when the access type is frozen. This is done when an
180 -- allocator is frozen, or an expression that may involve attributes of
181 -- the designated type. Otherwise freezing the access type does not freeze
182 -- the designated type.
184 procedure Process_Default_Expressions
187 -- This procedure is called for each subprogram to complete processing of
188 -- default expressions at the point where all types are known to be frozen.
189 -- The expressions must be analyzed in full, to make sure that all error
190 -- processing is done (they have only been preanalyzed). If the expression
191 -- is not an entity or literal, its analysis may generate code which must
192 -- not be executed. In that case we build a function body to hold that
193 -- code. This wrapper function serves no other purpose (it used to be
194 -- called to evaluate the default, but now the default is inlined at each
195 -- point of call).
198 -- Typ is a record or array type that is being frozen. This routine sets
199 -- the default component alignment from the scope stack values if the
200 -- alignment is otherwise not specified.
203 -- T is a record or array type that is being frozen. If it is a base type,
204 -- and if SSO_Set_Low/High_By_Default is set, then Reverse_Storage order
205 -- will be set appropriately. Note that an explicit occurrence of aspect
206 -- Scalar_Storage_Order or an explicit setting of this aspect with an
207 -- attribute definition clause occurs, then these two flags are reset in
208 -- any case, so call will have no effect.
211 -- T is a type of a component that we know to be an Itype. We don't want
212 -- this to have a Freeze_Node, so ensure it doesn't. Do the same for any
213 -- Full_View or Corresponding_Record_Type.
216 -- Expr is the expression for an address clause for entity Nam whose type
217 -- is Typ. If Typ has a default initialization, and there is no explicit
218 -- initialization in the source declaration, check whether the address
219 -- clause might cause overlaying of an entity, and emit a warning on the
220 -- side effect that the initialization will cause.
222 -------------------------------
223 -- Adjust_Esize_For_Alignment --
224 -------------------------------
229 begin
235 then
241 ------------------------------------
242 -- Build_And_Analyze_Renamed_Body --
243 ------------------------------------
245 procedure Build_And_Analyze_Renamed_Body
249 is
255 begin
256 -- If the renamed subprogram is intrinsic, there is no need for a
257 -- wrapper body: we set the alias that will be called and expanded which
258 -- completes the declaration. This transformation is only legal if the
259 -- renamed entity has already been elaborated.
261 -- Note that it is legal for a renaming_as_body to rename an intrinsic
262 -- subprogram, as long as the renaming occurs before the new entity
263 -- is frozen (RM 8.5.4 (5)).
267 then
269 else
275 and then
279 -- We can make the renaming entity intrinsic if the renamed function
280 -- has an interface name, or if it is one of the shift/rotate
281 -- operations known to the compiler.
283 and then
286 Name_Rotate_Right,
287 Name_Shift_Left,
288 Name_Shift_Right,
289 Name_Shift_Right_Arithmetic))
290 then
295 else
302 else
311 ------------------------
312 -- Build_Renamed_Body --
313 ------------------------
315 function Build_Renamed_Body
318 is
320 -- We use for the source location of the renamed body, the location of
321 -- the spec entity. It might seem more natural to use the location of
322 -- the renaming declaration itself, but that would be wrong, since then
323 -- the body we create would look as though it was created far too late,
324 -- and this could cause problems with elaboration order analysis,
325 -- particularly in connection with instantiations.
340 -- If the renamed entity is a primitive operation given in prefix form,
341 -- the prefix is the target object and it has to be added as the first
342 -- actual in the generated call.
344 begin
345 -- Determine the entity being renamed, which is the target of the call
346 -- statement. If the name is an explicit dereference, this is a renaming
347 -- of a subprogram type rather than a subprogram. The name itself is
348 -- fully analyzed.
359 else
366 else
372 -- If the renamed entity is a predefined operator, retain full name
373 -- to ensure its visibility.
377 then
379 else
383 else
386 and then
389 then
391 -- Retrieve the target object, to be added as a first actual
392 -- in the call.
397 else
401 -- Original name may have been overloaded, but is fully resolved now
406 -- For simple renamings, subsequent calls can be expanded directly as
407 -- calls to the renamed entity. The body must be generated in any case
408 -- for calls that may appear elsewhere. This is not done in the case
409 -- where the subprogram is an instantiation because the actual proper
410 -- body has not been built yet.
415 then
419 -- Check whether the return type is a limited view. If the subprogram
420 -- is already frozen the generated body may have a non-limited view
421 -- of the type, that must be used, because it is the one in the spec
422 -- of the renaming declaration.
426 then
427 declare
429 begin
431 Set_Result_Definition
437 -- The body generated for this renaming is an internal artifact, and
438 -- does not constitute a freeze point for the called entity.
445 declare
449 begin
450 -- The controlling formal may be an access parameter, or the
451 -- actual may be an access value, so adjust accordingly.
455 then
456 Actuals := New_List
461 then
462 Actuals :=
463 New_List (
467 else
475 else
486 -- If the renamed entity is an entry, inherit its profile. For other
487 -- renamings as bodies, both profiles must be subtype conformant, so it
488 -- is not necessary to replace the profile given in the declaration.
489 -- However, default values that are aggregates are rewritten when
490 -- partially analyzed, so we recover the original aggregate to insure
491 -- that subsequent conformity checking works. Similarly, if the default
492 -- expression was constant-folded, recover the original expression.
502 N_Access_Definition
503 then
511 then
522 -- If the renamed entity is a function, the generated body contains a
523 -- return statement. Otherwise, build a procedure call. If the entity is
524 -- an entry, subsequent analysis of the call will transform it into the
525 -- proper entry or protected operation call. If the renamed entity is
526 -- a character literal, return it directly.
532 then
533 Call_Node :=
535 Expression =>
541 Call_Node :=
546 Call_Node :=
549 else
550 Call_Node :=
556 -- Create entities for subprogram body and formals
569 Body_Node :=
573 Handled_Statement_Sequence =>
583 -- Link the body to the entity whose declaration it completes. If
584 -- the body is analyzed when the renamed entity is frozen, it may
585 -- be necessary to restore the proper scope (see package Exp_Ch13).
589 then
591 else
598 --------------------------
599 -- Check_Address_Clause --
600 --------------------------
611 begin
614 -- For a deferred constant, the initialization value is on full view
618 else
627 -- Has_Delayed_Freeze was set on E when the address clause was
628 -- analyzed, and must remain set because we want the address
629 -- clause to be elaborated only after any entity it references
630 -- has been elaborated.
633 -- If Rep_Clauses are to be ignored, remove address clause from
634 -- list attached to entity, because it may be illegal for gigi,
635 -- for example by breaking order of elaboration..
638 declare
641 begin
647 else
650 loop
660 -- And now remove the address clause
666 then
672 -- If a variable, or a non-imported constant, overlays a constant
673 -- object and has an initialization value, then the initialization
674 -- may end up writing into read-only memory. Detect the cases of
675 -- statically identical values and remove the initialization. In
676 -- the other cases, give a warning. We will give other warnings
677 -- later for the variable if it is assigned.
684 then
685 declare
689 begin
695 and then Compile_Time_Compare
699 then
704 and then Address_Clause_Overlay_Warnings
705 then
707 Error_Msg_NE
714 -- Remove side effects from initial expression, except in the case of
715 -- limited build-in-place calls and aggregates, which have their own
716 -- expansion elsewhere. This exception is necessary to avoid copying
717 -- limited objects.
721 -- Capture initialization value at point of declaration, and make
722 -- explicit assignment legal, because object may be a constant.
728 -- Move initialization to freeze actions, once the object has
729 -- been frozen and the address clause alignment check has been
730 -- performed.
739 -- If the object is tagged, check whether the tag must be
740 -- reassigned explicitly.
750 -----------------------------
751 -- Check_Compile_Time_Size --
752 -----------------------------
757 -- Sets the compile time known size (64 bits or less) in the RM_Size
758 -- field of T, checking for a size clause that was given which attempts
759 -- to give a smaller size.
762 -- Recursive function that does all the work
765 -- If T is a constrained subtype, its size is not known if any of its
766 -- discriminant constraints is not static and it is not a null record.
767 -- The test is conservative and doesn't check that the components are
768 -- in fact constrained by non-static discriminant values. Could be made
769 -- more precise ???
771 --------------------
772 -- Set_Small_Size --
773 --------------------
776 begin
780 -- Check for bad size clause given
785 Error_Msg_NE
790 -- Set size if not set already
797 ----------------
798 -- Size_Known --
799 ----------------
808 begin
812 -- Always True for elementary types, even generic formal elementary
813 -- types. We used to return False in the latter case, but the size
814 -- is known at compile time, even in the template, we just do not
815 -- know the exact size but that's not the point of this routine.
820 -- Array types
824 -- String literals always have known size, and we can set it
827 Set_Small_Size
831 -- Unconstrained types never have known at compile time size
836 -- Don't do any recursion on type with error posted, since we may
837 -- have a malformed type that leads us into a loop.
842 -- Otherwise if component size unknown, then array size unknown
848 -- Check for all indexes static, and also compute possible size
849 -- (in case it is not greater than 64 and may be packable).
851 declare
855 begin
864 else
872 then
875 else
880 else
892 -- For non-generic private types, go to underlying type if present
897 then
898 -- Don't do any recursion on type with error posted, since we may
899 -- have a malformed type that leads us into a loop.
903 else
907 -- Record types
911 -- A class-wide type is never considered to have a known size
916 -- A subtype of a variant record must not have non-static
917 -- discriminated components.
921 then
924 -- Don't do any recursion on type with error posted, since we may
925 -- have a malformed type that leads us into a loop.
931 -- Now look at the components of the record
933 declare
934 -- The following two variables are used to keep track of the
935 -- size of packed records if we can tell the size of the packed
936 -- record in the front end. Packed_Size_Known is True if so far
937 -- we can figure out the size. It is initialized to True for a
938 -- packed record, unless the record has discriminants or atomic
939 -- components or independent components.
941 -- The reason we eliminate the discriminated case is that
942 -- we don't know the way the back end lays out discriminated
943 -- packed records. If Packed_Size_Known is True, then
944 -- Packed_Size is the size in bits so far.
953 -- Size in bits so far
955 begin
956 -- Test for variant part present
962 N_Record_Definition
964 and then
965 Present (Variant_Part
967 then
968 -- If variant part is present, and type is unconstrained,
969 -- then we must have defaulted discriminants, or a size
970 -- clause must be present for the type, or else the size
971 -- is definitely not known at compile time.
974 and then
977 then
982 -- Loop through components
988 -- We do not know the packed size if there is a component
989 -- clause present (we possibly could, but this would only
990 -- help in the case of a record with partial rep clauses.
991 -- That's because in the case of full rep clauses, the
992 -- size gets figured out anyway by a different circuit).
998 -- We do not know the packed size for an atomic/VFA type
999 -- or component, or an independent type or component, or a
1000 -- by-reference type or aliased component (because packing
1001 -- does not touch these).
1009 then
1013 -- We need to identify a component that is an array where
1014 -- the index type is an enumeration type with non-standard
1015 -- representation, and some bound of the type depends on a
1016 -- discriminant.
1018 -- This is because gigi computes the size by doing a
1019 -- substitution of the appropriate discriminant value in
1020 -- the size expression for the base type, and gigi is not
1021 -- clever enough to evaluate the resulting expression (which
1022 -- involves a call to rep_to_pos) at compile time.
1024 -- It would be nice if gigi would either recognize that
1025 -- this expression can be computed at compile time, or
1026 -- alternatively figured out the size from the subtype
1027 -- directly, where all the information is at hand ???
1031 then
1032 declare
1040 begin
1047 then
1053 then
1058 then
1068 -- Clearly size of record is not known if the size of one of
1069 -- the components is not known.
1075 -- Accumulate packed size if possible
1079 -- We can deal with elementary types, small packed arrays
1080 -- if the representation is a modular type and also small
1081 -- record types (if the size is not greater than 64, but
1082 -- the condition is checked by Set_Small_Size).
1086 and then Present
1088 and then Is_Modular_Integer_Type
1091 then
1092 -- If RM_Size is known and static, then we can keep
1093 -- accumulating the packed size.
1099 -- If we have a field whose RM_Size is not known then
1100 -- we can't figure out the packed size here.
1102 else
1106 -- For other types we can't figure out the packed size
1108 else
1123 -- All other cases, size not known at compile time
1125 else
1130 -------------------------------------
1131 -- Static_Discriminated_Components --
1132 -------------------------------------
1134 function Static_Discriminated_Components
1136 is
1139 begin
1143 then
1157 -- Start of processing for Check_Compile_Time_Size
1159 begin
1163 -----------------------------------
1164 -- Check_Component_Storage_Order --
1165 -----------------------------------
1167 procedure Check_Component_Storage_Order
1172 is
1181 -- Set for the record case, True if Comp is aligned on byte boundaries
1182 -- (in which case it is allowed to have different storage order).
1185 -- Set True when the component is a nested composite, and it does not
1186 -- have the same scalar storage order as Encl_Type.
1188 begin
1189 -- Record case
1199 else
1200 -- If a component clause is present, check if the component starts
1201 -- and ends on byte boundaries. Otherwise conservatively assume it
1202 -- does so only in the case where the record is not packed.
1205 Comp_Byte_Aligned :=
1207 and then
1209 else
1216 -- Array case
1218 else
1225 -- Note: the Reverse_Storage_Order flag is set on the base type, but
1226 -- the attribute definition clause is attached to the first subtype.
1227 -- Also, if the base type is incomplete or private, go to full view
1228 -- if known
1240 Comp_ADC :=
1241 Get_Attribute_Definition_Clause
1245 -- Case of record or array component: check storage order compatibility.
1246 -- But, if the record has Complex_Representation, then it is treated as
1247 -- a scalar in the back end so the storage order is irrelevant.
1252 then
1253 Comp_SSO_Differs :=
1257 -- Parent and extension must have same storage order
1261 Error_Msg_N
1266 -- If component and composite SSO differs, check that component
1267 -- falls on byte boundaries and isn't bit packed.
1271 -- Component SSO differs from enclosing composite:
1273 -- Reject if composite is a bit-packed array, as it is rewritten
1274 -- into an array of scalars.
1277 Error_Msg_N
1281 -- Reject if not byte aligned
1284 and then not Comp_Byte_Aligned
1285 then
1286 Error_Msg_N
1290 -- Warn if specified only for the outer composite
1293 Error_Msg_NE
1299 -- Enclosing type has explicit SSO: non-composite component must not
1300 -- be aliased.
1303 Error_Msg_N
1309 -----------------------------
1310 -- Check_Debug_Info_Needed --
1311 -----------------------------
1314 begin
1319 or else Debug_Generated_Code
1320 or else Debug_Flag_VV
1322 then
1327 -------------------------------
1328 -- Check_Expression_Function --
1329 -------------------------------
1333 -- Function to search for deferred constant
1335 -------------------
1336 -- Find_Constant --
1337 -------------------
1340 begin
1341 -- When a constant is initialized with the result of a dispatching
1342 -- call, the constant declaration is rewritten as a renaming of the
1343 -- displaced function result. This scenario is not a premature use of
1344 -- a constant even though the Has_Completion flag is not set.
1351 N_Object_Declaration
1355 then
1356 Error_Msg_NE
1364 then
1374 -- Local variables
1378 -- Start of processing for Check_Expression_Function
1380 begin
1383 -- The subprogram body created for the expression function is not
1384 -- itself a freeze point.
1389 then
1394 --------------------------------
1395 -- Check_Inherited_Conditions --
1396 --------------------------------
1407 -- Build corresponding pragmas for an operation whose ancestor has
1408 -- class-wide pre/postconditions. If the operation is inherited, the
1409 -- pragmas force the creation of a wrapper for the inherited operation.
1410 -- If the ancestor is being overridden, the pragmas are constructed only
1411 -- to verify their legality, in case they contain calls to other
1412 -- primitives that may haven been overridden.
1414 ---------------------------------------
1415 -- Build_Inherited_Condition_Pragmas --
1416 ---------------------------------------
1423 begin
1428 Build_Class_Wide_Expression
1435 if Needs_Wrapper
1437 and then Expander_Active
1438 then
1447 Build_Class_Wide_Expression
1454 if Needs_Wrapper
1456 and then Expander_Active
1457 then
1463 -- Start of processing for Check_Inherited_Conditions
1465 begin
1470 -- Map the overridden primitive to the overriding one. This takes
1471 -- care of all overridings and is done only once.
1475 then
1483 -- Perform validity checks on the inherited conditions of overriding
1484 -- operations, for conformance with LSP, and apply SPARK-specific
1485 -- restrictions on inherited conditions.
1493 then
1496 -- Analyze the contract items of the overridden operation, before
1497 -- they are rewritten as pragmas.
1501 -- In GNATprove mode this is where we can collect the inherited
1502 -- conditions, because we do not create the Check pragmas that
1503 -- normally convey the the modified class-wide conditions on
1504 -- overriding operations.
1509 -- Otherwise build the corresponding pragmas to check for legality
1510 -- of the inherited condition.
1512 else
1520 -- Now examine the inherited operations to check whether they require
1521 -- a wrapper to handle inherited conditions that call other primitives,
1522 -- so that LSP can be verified/enforced.
1534 -- Analyze the contract items of the parent operation, and
1535 -- determine whether a wrapper is needed. This is determined
1536 -- when the condition is rewritten in sem_prag, using the
1537 -- mapping between overridden and overriding operations built
1538 -- in the loop above.
1544 if Needs_Wrapper
1546 and then Expander_Active
1547 then
1548 -- We need to build a new primitive that overrides the inherited
1549 -- one, and whose inherited expression has been updated above.
1550 -- These expressions are the arguments of pragmas that are part
1551 -- of the declarations of the wrapper. The wrapper holds a single
1552 -- statement that is a call to the class-wide clone, where the
1553 -- controlling actuals are conversions to the corresponding type
1554 -- in the parent primitive:
1556 -- procedure New_Prim (F1 : T1; ...);
1557 -- procedure New_Prim (F1 : T1; ...) is
1558 -- pragma Check (Precondition, Expr);
1559 -- begin
1560 -- Par_Prim_Clone (Par_Type (F1), ...);
1561 -- end;
1563 -- If the primitive is a function the statement is a return
1564 -- statement with a call.
1566 declare
1573 begin
1575 New_Decl :=
1579 -- Insert the declaration and the body of the wrapper after
1580 -- type declaration that generates inherited operation. For
1581 -- a null procedure, the declaration implies a null body.
1585 then
1588 else
1589 -- Build body as wrapper to a call to the already built
1590 -- class-wide clone.
1592 New_Body :=
1593 Build_Class_Wide_Clone_Call
1596 Insert_List_After_And_Analyze
1608 ----------------------------
1609 -- Check_Strict_Alignment --
1610 ----------------------------
1615 begin
1633 then
1643 -------------------------
1644 -- Check_Unsigned_Type --
1645 -------------------------
1652 begin
1657 -- Do not attempt to analyze case where range was in error
1663 -- The situation that is nontrivial is something like:
1665 -- subtype x1 is integer range -10 .. +10;
1666 -- subtype x2 is x1 range 0 .. V1;
1667 -- subtype x3 is x2 range V2 .. V3;
1668 -- subtype x4 is x3 range V4 .. V5;
1670 -- where Vn are variables. Here the base type is signed, but we still
1671 -- know that x4 is unsigned because of the lower bound of x2.
1673 -- The only way to deal with this is to look up the ancestor chain
1676 loop
1690 else
1693 -- If no ancestor had a static lower bound, go to base type
1697 -- Note: the reason we still check for a compile time known
1698 -- value for the base type is that at least in the case of
1699 -- generic formals, we can have bounds that fail this test,
1700 -- and there may be other cases in error situations.
1712 then
1722 -----------------------------
1723 -- Is_Atomic_VFA_Aggregate --
1724 -----------------------------
1733 begin
1736 -- Array may be qualified, so find outer context
1753 then
1762 then
1771 New_N :=
1783 -----------------------------------------------
1784 -- Explode_Initialization_Compound_Statement --
1785 -----------------------------------------------
1790 begin
1793 then
1796 -- Note that we rewrite Init_Stmts into a NULL statement, rather than
1797 -- just removing it, because Freeze_All may rely on this particular
1798 -- Node_Id still being present in the enclosing list to know where to
1799 -- stop freezing.
1807 ----------------
1808 -- Freeze_All --
1809 ----------------
1811 -- Note: the easy coding for this procedure would be to just build a
1812 -- single list of freeze nodes and then insert them and analyze them
1813 -- all at once. This won't work, because the analysis of earlier freeze
1814 -- nodes may recursively freeze types which would otherwise appear later
1815 -- on in the freeze list. So we must analyze and expand the freeze nodes
1816 -- as they are generated.
1820 -- This is the internal recursive routine that does freezing of entities
1821 -- (but NOT the analysis of default expressions, which should not be
1822 -- recursive, we don't want to analyze those till we are sure that ALL
1823 -- the types are frozen).
1825 --------------------
1826 -- Freeze_All_Ent --
1827 --------------------
1835 -- If freeze nodes are present, insert and analyze, and reset cursor
1836 -- for next insertion.
1838 -------------------
1839 -- Process_Flist --
1840 -------------------
1843 begin
1850 else
1856 -- Start of processing for Freeze_All_Ent
1858 begin
1862 -- If the entity is an inner package which is not a package
1863 -- renaming, then its entities must be frozen at this point. Note
1864 -- that such entities do NOT get frozen at the end of the nested
1865 -- package itself (only library packages freeze).
1867 -- Same is true for task declarations, where anonymous records
1868 -- created for entry parameters must be frozen.
1874 then
1885 then
1892 N_Task_Type_Declaration)
1893 then
1896 End_Scope;
1898 -- For a derived tagged type, we must ensure that all the
1899 -- primitive operations of the parent have been frozen, so that
1900 -- their addresses will be in the parent's dispatch table at the
1901 -- point it is inherited.
1907 then
1908 declare
1915 begin
1922 then
1924 Process_Flist;
1934 Process_Flist;
1936 -- If already frozen, and there are delayed aspects, this is where
1937 -- we do the visibility check for these aspects (see Sem_Ch13 spec
1938 -- for a description of how we handle aspect visibility).
1942 -- Retrieve the visibility to the discriminants in order to
1943 -- analyze properly the aspects.
1947 declare
1950 begin
1956 then
1967 -- If an incomplete type is still not frozen, this may be a
1968 -- premature freezing because of a body declaration that follows.
1969 -- Indicate where the freezing took place. Freezing will happen
1970 -- if the body comes from source, but not if it is internally
1971 -- generated, for example as the body of a type invariant.
1973 -- If the freezing is caused by the end of the current declarative
1974 -- part, it is a Taft Amendment type, and there is no error.
1978 then
1979 declare
1982 begin
1983 -- The presence of a body freezes all entities previously
1984 -- declared in the current list of declarations, but this
1985 -- does not apply if the body does not come from source.
1986 -- A type invariant is transformed into a subprogram body
1987 -- which is placed at the end of the private part of the
1988 -- current package, but this body does not freeze incomplete
1989 -- types that may be declared in this private part.
1992 N_Package_Body,
1993 N_Protected_Body,
1994 N_Subprogram_Body,
1995 N_Task_Body)
1997 and then
2000 then
2002 Error_Msg_NE
2013 -- Local variables
2019 -- Start of processing for Freeze_All
2021 begin
2024 -- Now that all types are frozen, we can deal with default expressions
2025 -- that require us to build a default expression functions. This is the
2026 -- point at which such functions are constructed (after all types that
2027 -- might be used in such expressions have been frozen).
2029 -- For subprograms that are renaming_as_body, we create the wrapper
2030 -- bodies as needed.
2032 -- We also add finalization chains to access types whose designated
2033 -- types are controlled. This is normally done when freezing the type,
2034 -- but this misses recursive type definitions where the later members
2035 -- of the recursion introduce controlled components.
2037 -- Loop through entities
2052 else
2058 and then
2060 N_Subprogram_Renaming_Declaration
2061 then
2062 Build_And_Analyze_Renamed_Body
2067 -- Freeze the default expressions of entries, entry families, and
2068 -- protected subprograms.
2075 then
2083 -- Historical note: We used to create a finalization master for an
2084 -- access type whose designated type is not controlled, but contains
2085 -- private controlled compoments. This form of postprocessing is no
2086 -- longer needed because the finalization master is now created when
2087 -- the access type is frozen (see Exp_Ch3.Freeze_Type).
2093 -----------------------
2094 -- Freeze_And_Append --
2095 -----------------------
2097 procedure Freeze_And_Append
2101 is
2103 begin
2107 else
2113 -------------------
2114 -- Freeze_Before --
2115 -------------------
2117 procedure Freeze_Before
2121 is
2122 -- Freeze T, then insert the generated Freeze nodes before the node N.
2123 -- Flag Freeze_Profile is used when T is an overloadable entity, and
2124 -- indicates whether its profile should be frozen at the same time.
2130 begin
2137 -- If the entity is a type declared in an inner package, it may be
2138 -- frozen by an outer declaration before the package itself is
2139 -- frozen. Install the package scope to analyze the freeze nodes,
2140 -- which may include generated subprograms such as predicate
2141 -- functions, etc.
2150 else
2156 -------------------
2157 -- Freeze_Entity --
2158 -------------------
2160 -- WARNING: This routine manages Ghost regions. Return statements must be
2161 -- replaced by gotos which jump to the end of the routine and restore the
2162 -- Ghost mode.
2164 function Freeze_Entity
2168 is
2173 -- Save the Ghost-related attributes to restore on exit
2182 -- This flag gets set to true for a variable with default initialization
2185 -- List of freezing actions, left at No_List if none
2188 -- This could use a comment ???
2191 -- Add freeze action Fnod to list Result
2194 -- If Loc is a freeze_entity that appears after the last declaration
2195 -- in the scope, inhibit error messages on late completion.
2198 -- Check that an Access or Unchecked_Access attribute with a prefix
2199 -- which is the current instance type can only be applied when the type
2200 -- is limited.
2203 -- Give a warning for pragma Convention with language C or C++ applied
2204 -- to a discriminated record type. This is suppressed for the unchecked
2205 -- union case, since the whole point in this case is interface C. We
2206 -- also do not generate this within instantiations, since we will have
2207 -- generated a message on the template.
2210 -- Give warning for modulus of 8, 16, 32, or 64 given as an explicit
2211 -- integer literal without an explicit corresponding size clause. The
2212 -- caller has checked that Utype is a modular integer type.
2215 -- Freeze array type, including freezing index and component types
2218 -- Perform checks and generate freeze node if needed for a constant or
2219 -- variable declared by an object declaration.
2222 -- Create Freeze_Generic_Entity nodes for types declared in a generic
2223 -- package. Recurse on inner generic packages.
2226 -- Freeze formals and return type of subprogram. If some type in the
2227 -- profile is incomplete and we are in an instance, freezing of the
2228 -- entity will take place elsewhere, and the function returns False.
2231 -- Freeze record type, including freezing component types, and freezing
2232 -- primitive operations if this is a tagged type.
2235 -- Determine whether an arbitrary entity is subject to Boolean aspect
2236 -- Import and its value is specified as True.
2238 procedure Inherit_Freeze_Node
2241 -- Set type Typ's freeze node to refer to Fnode. This routine ensures
2242 -- that any attributes attached to Typ's original node are preserved.
2245 -- If E is an entity for an imported subprogram with pre/post-conditions
2246 -- then this procedure will create a wrapper to ensure that proper run-
2247 -- time checking of the pre/postconditions. See body for details.
2249 -------------------
2250 -- Add_To_Result --
2251 -------------------
2254 begin
2255 -- The Ghost mode of the enclosing context is ignored, while the
2256 -- entity being frozen is living. Insert the freezing action prior
2257 -- to the start of the enclosing ignored Ghost region. As a result
2258 -- the freezeing action will be preserved when the ignored Ghost
2259 -- context is eliminated.
2264 then
2267 -- Otherwise add the freezing action to the result list
2269 else
2274 ----------------------------
2275 -- After_Last_Declaration --
2276 ----------------------------
2281 begin
2287 else
2291 else
2296 ----------------------------
2297 -- Check_Current_Instance --
2298 ----------------------------
2303 -- Determine whether Typ is compatible with the rules for aliased
2304 -- views of types as defined in RM 3.10 in the various dialects.
2307 -- Process routine to apply check to given node
2309 -----------------------------
2310 -- Is_Aliased_View_Of_Type --
2311 -----------------------------
2316 begin
2317 -- Common case
2321 then
2324 -- The following paragraphs describe what a legal aliased view of
2325 -- a type is in the various dialects of Ada.
2327 -- Ada 95
2329 -- The current instance of a limited type, and a formal parameter
2330 -- or generic formal object of a tagged type.
2332 -- Ada 95 limited type
2333 -- * Type with reserved word "limited"
2334 -- * A protected or task type
2335 -- * A composite type with limited component
2340 -- Ada 2005
2342 -- The current instance of a limited tagged type, a protected
2343 -- type, a task type, or a type that has the reserved word
2344 -- "limited" in its full definition ... a formal parameter or
2345 -- generic formal object of a tagged type.
2347 -- Ada 2005 limited type
2348 -- * Type with reserved word "limited", "synchronized", "task"
2349 -- or "protected"
2350 -- * A composite type with limited component
2351 -- * A derived type whose parent is a non-interface limited type
2354 return
2356 or else
2361 -- Ada 2012 and beyond
2363 -- The current instance of an immutably limited type ... a formal
2364 -- parameter or generic formal object of a tagged type.
2366 -- Ada 2012 limited type
2367 -- * Type with reserved word "limited", "synchronized", "task"
2368 -- or "protected"
2369 -- * A composite type with limited component
2370 -- * A derived type whose parent is a non-interface limited type
2371 -- * An incomplete view
2373 -- Ada 2012 immutably limited type
2374 -- * Explicitly limited record type
2375 -- * Record extension with "limited" present
2376 -- * Non-formal limited private type that is either tagged
2377 -- or has at least one access discriminant with a default
2378 -- expression
2379 -- * Task type, protected type or synchronized interface
2380 -- * Type derived from immutably limited type
2382 else
2383 return
2389 -------------
2390 -- Process --
2391 -------------
2394 begin
2398 Name_Unchecked_Access)
2402 then
2404 Error_Msg_N
2407 else
2408 Error_Msg_N
2415 else
2426 -- Local variables
2431 -- Start of processing for Check_Current_Instance
2433 begin
2439 ---------------------------------
2440 -- Check_Suspicious_Convention --
2441 ---------------------------------
2444 begin
2449 or else
2452 and then not In_Instance
2454 then
2455 declare
2460 begin
2465 Error_Msg_N
2468 else
2469 Error_Msg_N
2474 Error_Msg_NE
2482 ------------------------------
2483 -- Check_Suspicious_Modulus --
2484 ------------------------------
2489 begin
2495 declare
2498 begin
2500 declare
2504 begin
2506 declare
2510 begin
2511 -- First case, modulus and size are the same. This
2512 -- happens if you have something like mod 32, with
2513 -- an explicit size of 32, this is for sure a case
2514 -- where the warning is given, since it is seems
2515 -- very unlikely that someone would want e.g. a
2516 -- five bit type stored in 32 bits. It is much
2517 -- more likely they wanted a 32-bit type.
2522 -- Second case, the modulus is 32 or 64 and no
2523 -- size clause is present. This is a less clear
2524 -- case for giving the warning, but in the case
2525 -- of 32/64 (5-bit or 6-bit types) these seem rare
2526 -- enough that it is a likely error (and in any
2527 -- case using 2**5 or 2**6 in these cases seems
2528 -- clearer. We don't include 8 or 16 here, simply
2529 -- because in practice 3-bit and 4-bit types are
2530 -- more common and too many false positives if
2531 -- we warn in these cases.
2535 then
2538 -- No warning needed
2540 else
2544 -- If we fall through, give warning
2547 Error_Msg_N
2549 Modulus);
2558 -----------------------
2559 -- Freeze_Array_Type --
2560 -----------------------
2568 -- Set true if any of the index types is an enumeration type with a
2569 -- non-standard representation.
2571 begin
2580 then
2587 -- Processing that is done only for base types
2591 -- Deal with default setting of reverse storage order
2595 -- Propagate flags for component type
2599 then
2607 -- The array type requires its own invariant procedure in order to
2608 -- verify the component invariant over all elements. In GNATprove
2609 -- mode, the component invariants are checked by other means. They
2610 -- should not be added to the array type invariant procedure, so
2611 -- that the procedure can be used to check the array type
2612 -- invariants if any.
2615 and then not GNATprove_Mode
2616 then
2619 -- The array type is an implementation base type. Propagate the
2620 -- same property to the first subtype.
2627 -- Warn for pragma Pack overriding foreign convention
2631 then
2632 declare
2637 begin
2641 Error_Msg_N
2644 Error_Msg_N
2651 -- If packing was requested or if the component size was
2652 -- set explicitly, then see if bit packing is required. This
2653 -- processing is only done for base types, since all of the
2654 -- representation aspects involved are type-related.
2656 -- This is not just an optimization, if we start processing the
2657 -- subtypes, they interfere with the settings on the base type
2658 -- (this is because Is_Packed has a slightly different meaning
2659 -- before and after freezing).
2661 declare
2665 begin
2669 then
2678 else
2681 -- We can set the component size if it is less than 16,
2682 -- rounding it up to the next storage unit size.
2688 else
2692 -- Set component size up to match alignment if it would
2693 -- otherwise be less than the alignment. This deals with
2694 -- cases of types whose alignment exceeds their size (the
2695 -- padded type cases).
2698 declare
2700 begin
2708 -- Case of component size that may result in bit packing
2711 declare
2717 Get_Attribute_Definition_Clause
2720 begin
2721 -- Warn if we have pack and component size so that the
2722 -- pack is ignored.
2724 -- Note: here we must check for the presence of a
2725 -- component size before checking for a Pack pragma to
2726 -- deal with the case where the array type is a derived
2727 -- type whose parent is currently private.
2731 and then Warn_On_Redundant_Constructs
2732 then
2734 Error_Msg_NE
2736 Error_Msg_N
2742 -- Set component size if not already set by a component
2743 -- size clause.
2749 -- Check for base type of 8, 16, 32 bits, where an
2750 -- unsigned subtype has a length one less than the
2751 -- base type (e.g. Natural subtype of Integer).
2753 -- In such cases, if a component size was not set
2754 -- explicitly, then generate a warning.
2760 then
2764 Error_Msg_N
2766 Pack_Pragma);
2767 Error_Msg_N
2769 Pack_Pragma);
2773 -- Bit packing is never needed for 8, 16, 32, 64
2777 -- If the Esize of the component is known and equal to
2778 -- the component size then even packing is not needed.
2782 then
2783 -- Here the array was requested to be packed, but
2784 -- the packing request had no effect whatsoever,
2785 -- so flag Is_Packed is reset.
2787 -- Note: semantically this means that we lose track
2788 -- of the fact that a derived type inherited pragma
2789 -- Pack that was non-effective, but that is fine.
2791 -- We regard a Pack pragma as a request to set a
2792 -- representation characteristic, and this request
2793 -- may be ignored.
2797 else
2804 -- Bit packing is not needed for multiples of the storage
2805 -- unit if the type is composite because the back end can
2806 -- byte pack composite types.
2810 then
2815 -- In all other cases, bit packing is needed
2817 else
2826 -- Check for Aliased or Atomic_Components/Atomic/VFA with
2827 -- unsuitable packing or explicit component size clause given.
2832 and then
2834 then
2838 -- Outputs error messages for incorrect CS clause or pragma
2839 -- Pack for aliased or atomic/VFA components (T is "aliased"
2840 -- or "atomic/vfa");
2842 -----------------
2843 -- Complain_CS --
2844 -----------------
2847 begin
2849 Clause :=
2850 Get_Attribute_Definition_Clause
2853 Error_Msg_N
2857 Error_Msg_N
2860 else
2861 Error_Msg_N
2867 -- Start of processing for Alias_Atomic_Check
2869 begin
2870 -- If object size of component type isn't known, we cannot
2871 -- be sure so we defer to the back end.
2876 -- Case where component size has no effect. First check for
2877 -- object size of component type multiple of the storage
2878 -- unit size.
2882 -- OK in both packing case and component size case if RM
2883 -- size is known and static and same as the object size.
2885 and then
2889 -- Or if we have an explicit component size clause and
2890 -- the component size and object size are equal.
2892 or else
2895 then
2903 then
2912 -- Check for Independent_Components/Independent with unsuitable
2913 -- packing or explicit component size clause given.
2916 and then
2918 then
2919 begin
2920 -- If object size of component type isn't known, we cannot
2921 -- be sure so we defer to the back end.
2926 -- Case where component size has no effect. First check for
2927 -- object size of component type multiple of the storage
2928 -- unit size.
2932 -- OK in both packing case and component size case if RM
2933 -- size is known and multiple of the storage unit size.
2935 and then
2939 -- Or if we have an explicit component size clause and
2940 -- the component size is larger than the object size.
2942 or else
2945 then
2948 else
2950 Clause :=
2951 Get_Attribute_Definition_Clause
2954 Error_Msg_N
2958 Error_Msg_N
2961 else
2962 Error_Msg_N
2970 -- Warn for case of atomic type
2976 then
2977 Error_Msg_NE
2992 -- Check for scalar storage order
2994 declare
2996 begin
2997 Check_Component_Storage_Order
3000 ADC => Get_Attribute_Definition_Clause
3002 Attribute_Scalar_Storage_Order),
3006 -- Processing that is done only for subtypes
3008 else
3009 -- Acquire alignment from base type
3017 -- Specific checks for bit-packed arrays
3021 -- Check number of elements for bit-packed arrays that come from
3022 -- source and have compile time known ranges. The bit-packed
3023 -- arrays circuitry does not support arrays with more than
3024 -- Integer'Last + 1 elements, and when this restriction is
3025 -- violated, causes incorrect data access.
3027 -- For the case where this is not compile time known, a run-time
3028 -- check should be generated???
3031 declare
3037 begin
3043 -- Never generate an error if any index is of a generic
3044 -- type. We will check this in instances.
3051 Ilen :=
3057 -- No attempt is made to check number of elements if not
3058 -- compile time known.
3071 then
3072 Error_Msg_N
3079 -- Check size
3082 declare
3086 begin
3087 -- It is not clear if it is possible to have no size clause
3088 -- at this stage, but it is not worth worrying about. Post
3089 -- error on the entity name in the size clause if present,
3090 -- else on the type entity itself.
3094 else
3101 -- If any of the index types was an enumeration type with a non-
3102 -- standard rep clause, then we indicate that the array type is
3103 -- always packed (even if it is not bit-packed).
3112 -- If the array is packed and bit-packed or packed to eliminate holes
3113 -- in the non-contiguous enumeration index types, we must create the
3114 -- packed array type to be used to actually implement the type. This
3115 -- is only needed for real array types (not for string literal types,
3116 -- since they are present only for the front end).
3121 then
3125 -- Make sure that we have the necessary routines to implement the
3126 -- packing, and complain now if not. Note that we only test this
3127 -- for constrained array types.
3133 then
3134 declare
3138 begin
3141 then
3142 Error_Msg_CRT
3146 -- Cancel the packing
3156 -- Size information of packed array type is copied to the array
3157 -- type, since this is really the representation. But do not
3158 -- override explicit existing size values. If the ancestor subtype
3159 -- is constrained the Packed_Array_Impl_Type will be inherited
3160 -- from it, but the size may have been provided already, and
3161 -- must not be overridden either.
3164 and then
3167 then
3179 -- For non-packed arrays set the alignment of the array to the
3180 -- alignment of the component type if it is unknown. Skip this
3181 -- in atomic/VFA case (atomic/VFA arrays may need larger alignments).
3190 then
3194 -- A Ghost type cannot have a component of protected or task type
3195 -- (SPARK RM 6.9(19)).
3198 Error_Msg_N
3200 Arr);
3204 -------------------------------
3205 -- Freeze_Object_Declaration --
3206 -------------------------------
3210 -- Check that the size of array type Typ can be computed without
3211 -- overflow, and generates a Storage_Error otherwise. This is only
3212 -- relevant for array types whose index is a (mod 2**64) type, where
3213 -- wrap-around arithmetic might yield a meaningless value for the
3214 -- length of the array, or its corresponding attribute.
3216 -------------------------------
3217 -- Check_Large_Modular_Array --
3218 -------------------------------
3224 begin
3225 -- Nothing to do when expansion is disabled because this routine
3226 -- generates a runtime check.
3231 -- Nothing to do for String literal subtypes because their index
3232 -- cannot be a modular type.
3237 -- Nothing to do for an imported object because the object will
3238 -- be created on the exporting side.
3243 -- Nothing to do for unconstrained array types. This case arises
3244 -- when the object declaration is illegal.
3252 -- To prevent arithmetic overflow with large values, we raise
3253 -- Storage_Error under the following guard:
3254 --
3255 -- (Arr'Last / 2 - Arr'First / 2) > (2 ** 30)
3256 --
3257 -- This takes care of the boundary case, but it is preferable to
3258 -- use a smaller limit, because even on 64-bit architectures an
3259 -- array of more than 2 ** 30 bytes is likely to raise
3260 -- Storage_Error.
3264 then
3267 Condition =>
3269 Left_Opnd =>
3271 Left_Opnd =>
3273 Left_Opnd =>
3275 Prefix =>
3278 Right_Opnd =>
3280 Right_Opnd =>
3282 Left_Opnd =>
3284 Prefix =>
3287 Right_Opnd =>
3289 Right_Opnd =>
3295 -- Local variables
3300 -- Start of processing for Freeze_Object_Declaration
3302 begin
3303 -- Abstract type allowed only for C++ imported variables or constants
3305 -- Note: we inhibit this check for objects that do not come from
3306 -- source because there is at least one case (the expansion of
3307 -- x'Class'Input where x is abstract) where we legitimately
3308 -- generate an abstract object.
3313 then
3322 Error_Msg_N -- CODEFIX
3327 -- For object created by object declaration, perform required
3328 -- categorization (preelaborate and pure) checks. Defer these
3329 -- checks to freeze time since pragma Import inhibits default
3330 -- initialization and thus pragma Import affects these checks.
3334 -- If there is an address clause, check that it is valid and if need
3335 -- be move initialization to the freeze node.
3339 -- Similar processing is needed for aspects that may affect object
3340 -- layout, like Alignment, if there is an initialization expression.
3341 -- We don't do this if there is a pragma Linker_Section, because it
3342 -- would prevent the back end from statically initializing the
3343 -- object; we don't want elaboration code in that case.
3346 and then Expander_Active
3350 then
3351 declare
3355 begin
3356 -- Capture initialization value at point of declaration, and
3357 -- make explicit assignment legal, because object may be a
3358 -- constant.
3363 -- Move initialization to freeze actions
3371 -- Set_Is_Frozen (E, False);
3375 -- Reset Is_True_Constant for non-constant aliased object. We
3376 -- consider that the fact that a non-constant object is aliased may
3377 -- indicate that some funny business is going on, e.g. an aliased
3378 -- object is passed by reference to a procedure which captures the
3379 -- address of the object, which is later used to assign a new value,
3380 -- even though the compiler thinks that it is not modified. Such
3381 -- code is highly dubious, but we choose to make it "work" for
3382 -- non-constant aliased objects.
3384 -- Note that we used to do this for all aliased objects, whether or
3385 -- not constant, but this caused anomalies down the line because we
3386 -- ended up with static objects that were not Is_True_Constant. Not
3387 -- resetting Is_True_Constant for (aliased) constant objects ensures
3388 -- that this anomaly never occurs.
3390 -- However, we don't do that for internal entities. We figure that if
3391 -- we deliberately set Is_True_Constant for an internal entity, e.g.
3392 -- a dispatch table entry, then we mean it.
3397 then
3401 -- If the object needs any kind of default initialization, an error
3402 -- must be issued if No_Default_Initialization applies. The check
3403 -- doesn't apply to imported objects, which are not ever default
3404 -- initialized, and is why the check is deferred until freezing, at
3405 -- which point we know if Import applies. Deferred constants are also
3406 -- exempted from this test because their completion is explicit, or
3407 -- through an import pragma.
3415 and then
3419 or else
3422 then
3424 Check_Restriction
3428 -- Check that a Thread_Local_Storage variable does not have default
3429 -- initialization, and any explicit initialization must either be the
3430 -- null constant or a static constant.
3433 declare
3435 begin
3436 if Has_Default_Initialization
3437 or else
3439 and then
3441 or else not
3444 then
3447 then
3449 else
3450 Error_Msg_NE
3453 Error_Msg_NE
3461 -- For imported objects, set Is_Public unless there is also an
3462 -- address clause, which means that there is no external symbol
3463 -- needed for the Import (Is_Public may still be set for other
3464 -- unrelated reasons). Note that we delayed this processing
3465 -- till freeze time so that we can be sure not to set the flag
3466 -- if there is an address clause. If there is such a clause,
3467 -- then the only purpose of the Import pragma is to suppress
3468 -- implicit initialization.
3474 -- For source objects that are not Imported and are library level, if
3475 -- no linker section pragma was given inherit the appropriate linker
3476 -- section from the corresponding type.
3482 then
3486 -- For convention C objects of an enumeration type, warn if the size
3487 -- is not integer size and no explicit size given. Skip warning for
3488 -- Boolean and Character, and assume programmer expects 8-bit sizes
3489 -- for these cases.
3492 or else
3499 then
3501 Error_Msg_N
3511 -----------------------------
3512 -- Freeze_Generic_Entities --
3513 -----------------------------
3520 begin
3539 --------------------
3540 -- Freeze_Profile --
3541 --------------------
3548 begin
3549 -- Loop through formals
3555 -- AI05-0151: incomplete types can appear in a profile. By the
3556 -- time the entity is frozen, the full view must be available,
3557 -- unless it is a limited view.
3562 then
3576 then
3577 -- If the type of a formal is incomplete, subprogram is being
3578 -- frozen prematurely. Within an instance (but not within a
3579 -- wrapper package) this is an artifact of our need to regard
3580 -- the end of an instantiation as a freeze point. Otherwise it
3581 -- is a definite error.
3588 elsif not After_Last_Declaration
3589 and then not Freezing_Library_Level_Tagged_Type
3590 then
3592 Error_Msg
3597 -- Check suspicious parameter for C function. These tests apply
3598 -- only to exported/imported subprograms.
3600 if Warn_On_Export_Import
3603 or else
3610 then
3611 -- Qualify mention of formals with subprogram name
3615 -- Check suspicious use of fat C pointer, but do not emit
3616 -- a warning on an access to subprogram when unnesting is
3617 -- active.
3623 then
3624 Error_Msg_N
3627 -- Check suspicious return of boolean
3633 then
3634 Error_Msg_N
3636 Error_Msg_N
3640 -- Check suspicious tagged type
3643 or else
3647 then
3648 Error_Msg_N
3652 -- Check wrong convention subprogram pointer
3656 then
3657 Error_Msg_N
3661 Error_Msg_NE
3666 -- Turn off name qualification after message output
3671 -- Check for unconstrained array in exported foreign convention
3672 -- case.
3678 and then Warn_On_Export_Import
3679 then
3682 -- If this is an inherited operation, place the warning on
3683 -- the derived type declaration, rather than on the original
3684 -- subprogram.
3687 then
3693 else
3709 -- If the formal is an anonymous_access_to_subprogram
3710 -- freeze the subprogram type as well, to prevent
3711 -- scope anomalies in gigi, because there is no other
3712 -- clear point at which it could be frozen.
3716 then
3724 -- Case of function: similar checks on return type
3728 -- Freeze return type
3732 -- AI05-0151: the return type may have been incomplete at the
3733 -- point of declaration. Replace it with the full view, unless the
3734 -- current type is a limited view. In that case the full view is
3735 -- in a different unit, and gigi finds the non-limited view after
3736 -- the other unit is elaborated.
3741 then
3748 -- Check suspicious return type for C function
3750 if Warn_On_Export_Import
3752 or else
3755 then
3756 -- Check suspicious return of fat C pointer
3762 then
3763 Error_Msg_N
3765 E);
3767 -- Check suspicious return of boolean
3774 then
3775 declare
3778 begin
3779 Error_Msg_NE
3781 Error_Msg_NE
3786 -- Check suspicious return tagged type
3790 and then
3791 Is_Tagged_Type
3796 then
3800 -- Check return of wrong convention subprogram pointer
3806 then
3810 Error_Msg_NE
3816 -- Give warning for suspicious return of a result of an
3817 -- unconstrained array type in a foreign convention function.
3821 -- We are looking for a return of unconstrained array
3826 -- Exclude imported routines, the warning does not belong on
3827 -- the import, but rather on the routine definition.
3831 -- Check that general warning is enabled, and that it is not
3832 -- suppressed for this particular case.
3834 and then Warn_On_Export_Import
3837 then
3838 Error_Msg_N
3844 -- Check suspicious use of Import in pure unit (cases where the RM
3845 -- allows calls to be omitted).
3849 -- It might be suspicious if the compilation unit has the Pure
3850 -- aspect/pragma.
3854 -- The RM allows omission of calls only in the case of
3855 -- library-level subprograms (see RM-10.2.1(18)).
3859 -- Ignore internally generated entity. This happens in some cases
3860 -- of subprograms in specs, where we generate an implied body.
3864 -- Assume run-time knows what it is doing
3866 and then not GNAT_Mode
3868 -- Assume explicit Pure_Function means import is pure
3872 -- Don't need warning in relaxed semantics mode
3874 and then not Relaxed_RM_Semantics
3876 -- Assume convention Intrinsic is OK, since this is specialized.
3877 -- This deals with the DEC unit current_exception.ads
3881 -- Assume that ASM interface knows what it is doing. This deals
3882 -- with e.g. unsigned.ads in the AAMP back end.
3885 then
3886 Error_Msg_N
3888 Error_Msg_NE
3896 ------------------------
3897 -- Freeze_Record_Type --
3898 ------------------------
3910 -- Set True if we find at least one component which is aliased. This
3911 -- is used to prevent Implicit_Packing of the record, since packing
3912 -- cannot modify the size of alignment of an aliased component.
3915 -- True if all components are of a type whose underlying type is
3916 -- elementary.
3919 -- True if all components have a known RM_Size
3922 -- True if all components have an RM_Size that is a multiple of the
3923 -- storage unit.
3926 -- Accumulates total Esize values of all elementary components. Used
3927 -- for processing of Implicit_Packing.
3930 -- Set True if we find at least one component with a component
3931 -- clause (used to warn about useless Bit_Order pragmas, and also
3932 -- to detect cases where Implicit_Packing may have an effect).
3935 -- Set True if the record type scope Rec has been pushed on the scope
3936 -- stack. Needed for the analysis of delayed aspects specified to the
3937 -- components of Rec.
3940 -- Accumulates total RM_Size values of all sized components. Used
3941 -- for processing of Implicit_Packing.
3944 -- Accumulates total RM_Size values of all sized components, rounded
3945 -- individually to a multiple of the storage unit.
3948 -- Scalar_Storage_Order attribute definition clause for the record
3951 -- Set True if we find at least one component whose type has a
3952 -- Scalar_Storage_Order attribute definition clause.
3955 -- Set True if we find at least one component with no component
3956 -- clause (used to warn about useless Pack pragmas).
3959 -- If N is an allocator, possibly wrapped in one or more level of
3960 -- qualified expression(s), return the inner allocator node, else
3961 -- return Empty.
3964 -- If the component subtype is an access to a constrained subtype of
3965 -- an already frozen type, make the subtype frozen as well. It might
3966 -- otherwise be frozen in the wrong scope, and a freeze node on
3967 -- subtype has no effect. Similarly, if the component subtype is a
3968 -- regular (not protected) access to subprogram, set the anonymous
3969 -- subprogram type to frozen as well, to prevent an out-of-scope
3970 -- freeze node at some eventual point of call. Protected operations
3971 -- are handled elsewhere.
3974 -- Make sure that all types mentioned in Discrete_Choices of the
3975 -- variants referenceed by the Variant_Part VP are frozen. This is
3976 -- a recursive routine to deal with nested variants.
3978 ---------------------
3979 -- Check_Allocator --
3980 ---------------------
3984 begin
3986 loop
3991 else
3997 -----------------
3998 -- Check_Itype --
3999 -----------------
4004 begin
4007 then
4010 -- In addition, add an Itype_Reference to ensure that the
4011 -- access subtype is elaborated early enough. This cannot be
4012 -- done if the subtype may depend on discriminants.
4017 then
4025 then
4030 ------------------------------------
4031 -- Freeze_Choices_In_Variant_Part --
4032 ------------------------------------
4041 begin
4042 -- Loop through variants
4047 -- Loop through choices, checking that all types are frozen
4053 then
4060 -- Check for nested variant part to process
4074 -- Start of processing for Freeze_Record_Type
4076 begin
4077 -- Deal with delayed aspect specifications for components. The
4078 -- analysis of the aspect is required to be delayed to the freeze
4079 -- point, thus we analyze the pragma or attribute definition
4080 -- clause in the tree at this point. We also analyze the aspect
4081 -- specification node at the freeze point when the aspect doesn't
4082 -- correspond to pragma/attribute definition clause.
4088 then
4093 -- The visibility to the discriminants must be restored in
4094 -- order to properly analyze the aspects.
4107 -- Pop the scope if Rec scope has been pushed on the scope stack
4108 -- during the delayed aspect analysis process.
4115 Pop_Scope;
4118 -- Freeze components and embedded subtypes
4127 -- Handle the component and discriminant case
4130 declare
4133 begin
4134 -- Freezing a record type freezes the type of each of its
4135 -- components. However, if the type of the component is
4136 -- part of this record, we do not want or need a separate
4137 -- Freeze_Node. Note that Is_Itype is wrong because that's
4138 -- also set in private type cases. We also can't check for
4139 -- the Scope being exactly Rec because of private types and
4140 -- record extensions.
4145 then
4151 -- Warn for pragma Pack overriding foreign convention
4156 -- Don't warn for aliased components, since override
4157 -- cannot happen in that case.
4160 then
4161 declare
4166 begin
4170 Error_Msg_N
4172 PP);
4174 Error_Msg_NE
4181 -- Check for error of component clause given for variable
4182 -- sized type. We have to delay this test till this point,
4183 -- since the component type has to be frozen for us to know
4184 -- if it is variable length.
4189 -- We omit this test in a generic context, it will be
4190 -- applied at instantiation time.
4195 -- Also omit this test in CodePeer mode, since we do not
4196 -- have sufficient info on size and rep clauses.
4201 -- Omit check if component has a generic type. This can
4202 -- happen in an instantiation within a generic in ASIS
4203 -- mode, where we force freeze actions without full
4204 -- expansion.
4209 -- Do the check
4211 elsif not
4212 Size_Known_At_Compile_Time
4214 then
4215 Error_Msg_N
4220 else
4224 -- Case of component requires byte alignment
4228 -- Set the enclosing record to also require byte align
4232 -- Check for component clause that is inconsistent with
4233 -- the required byte boundary alignment.
4238 then
4239 Error_Msg_N
4247 -- Gather data for possible Implicit_Packing later. Note that at
4248 -- this stage we might be dealing with a real component, or with
4249 -- an implicit subtype declaration.
4252 declare
4257 begin
4258 Sized_Component_Total_RM_Size :=
4261 Sized_Component_Total_Round_RM_Size :=
4262 Sized_Component_Total_Round_RM_Size +
4267 then
4268 Elem_Component_Total_Esize :=
4270 else
4278 else
4282 -- If the component is an Itype with Delayed_Freeze and is either
4283 -- a record or array subtype and its base type has not yet been
4284 -- frozen, we must remove this from the entity list of this record
4285 -- and put it on the entity list of the scope of its base type.
4286 -- Note that we know that this is not the type of a component
4287 -- since we cleared Has_Delayed_Freeze for it in the previous
4288 -- loop. Thus this must be the Designated_Type of an access type,
4289 -- which is the type of a component.
4297 then
4298 declare
4302 begin
4303 -- We have a difficult case to handle here. Suppose Rec is
4304 -- subtype being defined in a subprogram that's created as
4305 -- part of the freezing of Rec'Base. In that case, we know
4306 -- that Comp'Base must have already been frozen by the time
4307 -- we get to elaborate this because Gigi doesn't elaborate
4308 -- any bodies until it has elaborated all of the declarative
4309 -- part. But Is_Frozen will not be set at this point because
4310 -- we are processing code in lexical order.
4312 -- We detect this case by going up the Scope chain of Rec
4313 -- and seeing if we have a subprogram scope before reaching
4314 -- the top of the scope chain or that of Comp'Base. If we
4315 -- do, then mark that Comp'Base will actually be frozen. If
4316 -- so, we merely undelay it.
4333 else
4336 else
4340 -- Insert in entity list of scope of base type (which
4341 -- must be an enclosing scope, because still unfrozen).
4347 -- If the component is an access type with an allocator as default
4348 -- value, the designated type will be frozen by the corresponding
4349 -- expression in init_proc. In order to place the freeze node for
4350 -- the designated type before that for the current record type,
4351 -- freeze it now.
4353 -- Same process if the component is an array of access types,
4354 -- initialized with an aggregate. If the designated type is
4355 -- private, it cannot contain allocators, and it is premature
4356 -- to freeze the type, so we check for this as well.
4361 then
4362 declare
4366 begin
4369 -- If component is pointer to a class-wide type, freeze
4370 -- the specific type in the expression being allocated.
4371 -- The expression may be a subtype indication, in which
4372 -- case freeze the subtype mark.
4374 if Is_Class_Wide_Type
4376 then
4378 Freeze_And_Append
4382 then
4383 Freeze_And_Append
4391 else
4392 Freeze_And_Append
4400 then
4403 -- Freeze the designated type when initializing a component with
4404 -- an aggregate in case the aggregate contains allocators.
4406 -- type T is ...;
4407 -- type T_Ptr is access all T;
4408 -- type T_Array is array ... of T_Ptr;
4410 -- type Rec is record
4411 -- Comp : T_Array := (others => ...);
4412 -- end record;
4416 then
4417 declare
4420 Designated_Type
4423 begin
4424 -- The only case when this sort of freezing is not done is
4425 -- when the designated type is class-wide and the root type
4426 -- is the record owning the component. This scenario results
4427 -- in a circularity because the class-wide type requires
4428 -- primitives that have not been created yet as the root
4429 -- type is in the process of being frozen.
4431 -- type Rec is tagged;
4432 -- type Rec_Ptr is access all Rec'Class;
4433 -- type Rec_Array is array ... of Rec_Ptr;
4435 -- type Rec is record
4436 -- Comp : Rec_Array := (others => ...);
4437 -- end record;
4441 then
4449 then
4459 SSO_ADC :=
4460 Get_Attribute_Definition_Clause
4463 -- If the record type has Complex_Representation, then it is treated
4464 -- as a scalar in the back end so the storage order is irrelevant.
4468 Error_Msg_N
4470 SSO_ADC);
4473 else
4474 -- Deal with default setting of reverse storage order
4478 -- Check consistent attribute setting on component types
4480 declare
4482 begin
4485 Check_Component_Storage_Order
4495 -- Now deal with reverse storage order/bit order issues
4499 -- Check compatibility of Scalar_Storage_Order with Bit_Order,
4500 -- if the former is specified.
4504 -- Note: report error on Rec, not on SSO_ADC, as ADC may
4505 -- apply to some ancestor type.
4508 Error_Msg_N
4513 -- Warn if there is a Scalar_Storage_Order attribute definition
4514 -- clause but no component clause, no component that itself has
4515 -- such an attribute definition, and no pragma Pack.
4518 or else
4519 SSO_ADC_Component
4520 or else
4522 then
4523 Error_Msg_N
4530 -- Deal with Bit_Order aspect
4538 then
4539 -- Warn if clause has no effect when no component clause is
4540 -- present, but suppress warning if the Bit_Order is required
4541 -- due to the presence of a Scalar_Storage_Order attribute.
4543 Error_Msg_N
4545 Error_Msg_N
4548 -- Here is where we do the processing to adjust component clauses
4549 -- for reversed bit order, when not using reverse SSO. If an error
4550 -- has been reported on Rec already (such as SSO incompatible with
4551 -- bit order), don't bother adjusting as this may generate extra
4552 -- noise.
4557 then
4560 -- Case where we have both an explicit Bit_Order and the same
4561 -- Scalar_Storage_Order: leave record untouched, the back-end
4562 -- will take care of required layout conversions.
4564 else
4570 -- Complete error checking on record representation clause (e.g.
4571 -- overlap of components). This is called after adjusting the
4572 -- record for reverse bit order.
4574 declare
4576 begin
4582 -- Check for useless pragma Pack when all components placed. We only
4583 -- do this check for record types, not subtypes, since a subtype may
4584 -- have all its components placed, and it still makes perfectly good
4585 -- sense to pack other subtypes or the parent type. We do not give
4586 -- this warning if Optimize_Alignment is set to Space, since the
4587 -- pragma Pack does have an effect in this case (it always resets
4588 -- the alignment to one).
4592 and then not Unplaced_Component
4594 then
4595 -- Reset packed status. Probably not necessary, but we do it so
4596 -- that there is no chance of the back end doing something strange
4597 -- with this redundant indication of packing.
4601 -- Give warning if redundant constructs warnings on
4604 Error_Msg_N -- CODEFIX
4610 -- If this is the record corresponding to a remote type, freeze the
4611 -- remote type here since that is what we are semantically freezing.
4612 -- This prevents the freeze node for that type in an inner scope.
4619 -- Check for controlled components, unchecked unions, and type
4620 -- invariants.
4625 -- Do not set Has_Controlled_Component on a class-wide
4626 -- equivalent type. See Make_CW_Equivalent_Type.
4629 and then
4631 or else
4634 or else
4636 and then
4638 and then
4639 Has_Controlled_Component
4641 then
4649 -- The record type requires its own invariant procedure in
4650 -- order to verify the invariant of each individual component.
4651 -- Do not consider internal components such as _parent because
4652 -- parent class-wide invariants are always inherited.
4653 -- In GNATprove mode, the component invariants are checked by
4654 -- other means. They should not be added to the record type
4655 -- invariant procedure, so that the procedure can be used to
4656 -- check the recordy type invariants if any.
4660 and then not GNATprove_Mode
4661 then
4665 -- Scan component declaration for likely misuses of current
4666 -- instance, either in a constraint or a default expression.
4676 -- Enforce the restriction that access attributes with a current
4677 -- instance prefix can only apply to limited types. This comment
4678 -- is floating here, but does not seem to belong here???
4680 -- Set component alignment if not otherwise already set
4684 -- For first subtypes, check if there are any fixed-point fields with
4685 -- component clauses, where we must check the size. This is not done
4686 -- till the freeze point since for fixed-point types, we do not know
4687 -- the size until the type is frozen. Similar processing applies to
4688 -- bit-packed arrays.
4696 then
4697 Check_Size
4701 Junk);
4708 -- See if Size is too small as is (and implicit packing might help)
4712 -- No implicit packing if even one component is explicitly placed
4714 and then not Placed_Component
4716 -- Or even one component is aliased
4718 and then not Aliased_Component
4720 -- Must have size clause and all sized components
4723 and then All_Sized_Components
4725 -- Do not try implicit packing on records with discriminants, too
4726 -- complicated, especially in the variant record case.
4730 -- We want to implicitly pack if the specified size of the record
4731 -- is less than the sum of the object sizes (no point in packing
4732 -- if this is not the case), if we can compute it, i.e. if we have
4733 -- only elementary components. Otherwise, we have at least one
4734 -- composite component and we want to implicitly pack only if bit
4735 -- packing is required for it, as we are sure in this case that
4736 -- the back end cannot do the expected layout without packing.
4738 and then
4739 ((All_Elem_Components
4741 or else
4743 and then not All_Storage_Unit_Components
4746 -- And the total RM size cannot be greater than the specified size
4747 -- since otherwise packing will not get us where we have to be.
4751 -- Never do implicit packing in CodePeer or SPARK modes since
4752 -- we don't do any packing in these modes, since this generates
4753 -- over-complex code that confuses static analysis, and in
4754 -- general, neither CodePeer not GNATprove care about the
4755 -- internal representation of objects.
4758 then
4759 -- If implicit packing enabled, do it
4764 -- Otherwise flag the size clause
4766 else
4767 declare
4769 begin
4770 Error_Msg_NE -- CODEFIX
4772 Error_Msg_N -- CODEFIX
4779 -- The following checks are relevant only when SPARK_Mode is on as
4780 -- they are not standard Ada legality rules.
4784 -- A discriminated type cannot be effectively volatile
4785 -- (SPARK RM 7.1.3(5)).
4792 -- A non-effectively volatile record type cannot contain
4793 -- effectively volatile components (SPARK RM 7.1.3(6)).
4795 else
4800 then
4802 Error_Msg_N
4811 -- A type which does not yield a synchronized object cannot have
4812 -- a component that yields a synchronized object (SPARK RM 9.5).
4819 then
4821 Error_Msg_N
4830 -- A Ghost type cannot have a component of protected or task type
4831 -- (SPARK RM 6.9(19)).
4838 then
4840 Error_Msg_N
4842 Comp);
4850 -- Make sure that if we have an iterator aspect, then we have
4851 -- either Constant_Indexing or Variable_Indexing.
4853 declare
4856 begin
4865 or else
4867 then
4869 else
4870 Error_Msg_N
4872 Iterator_Aspect);
4877 -- All done if not a full record definition
4883 -- Finally we need to check the variant part to make sure that
4884 -- all types within choices are properly frozen as part of the
4885 -- freezing of the record type.
4892 begin
4893 -- Find component list
4905 then
4910 -- Case of variant part present
4916 -- Note: we used to call Check_Choices here, but it is too early,
4917 -- since predicated subtypes are frozen here, but their freezing
4918 -- actions are in Analyze_Freeze_Entity, which has not been called
4919 -- yet for entities frozen within this procedure, so we moved that
4920 -- call to the Analyze_Freeze_Entity for the record type.
4924 -- Check that all the primitives of an interface type are abstract
4925 -- or null procedures.
4929 then
4930 declare
4934 begin
4941 -- Avoid reporting the error on inherited primitives
4944 then
4949 Error_Msg_N
4953 else
4954 Error_Msg_N
4965 -- For a derived tagged type, check whether inherited primitives
4966 -- might require a wrapper to handle class-wide conditions.
4973 -------------------------------
4974 -- Has_Boolean_Aspect_Import --
4975 -------------------------------
4982 begin
4988 -- The value of aspect Import is True when the expression is
4989 -- either missing or it is explicitly set to True.
4995 then
5006 -------------------------
5007 -- Inherit_Freeze_Node --
5008 -------------------------
5010 procedure Inherit_Freeze_Node
5013 is
5016 begin
5020 -- The input type had an existing node. Propagate relevant attributes
5021 -- from the old freeze node to the inherited freeze node.
5023 -- ??? if both freeze nodes have attributes, would they differ?
5027 -- Attribute Access_Types_To_Process
5031 then
5036 -- Attribute Actions
5042 -- Attribute First_Subtype_Link
5046 then
5050 -- Attribute TSS_Elist
5054 then
5060 ------------------------------
5061 -- Wrap_Imported_Subprogram --
5062 ------------------------------
5064 -- The issue here is that our normal approach of checking preconditions
5065 -- and postconditions does not work for imported procedures, since we
5066 -- are not generating code for the body. To get around this we create
5067 -- a wrapper, as shown by the following example:
5069 -- procedure K (A : Integer);
5070 -- pragma Import (C, K);
5072 -- The spec is rewritten by removing the effects of pragma Import, but
5073 -- leaving the convention unchanged, as though the source had said:
5075 -- procedure K (A : Integer);
5076 -- pragma Convention (C, K);
5078 -- and we create a body, added to the entity K freeze actions, which
5079 -- looks like:
5081 -- procedure K (A : Integer) is
5082 -- procedure K (A : Integer);
5083 -- pragma Import (C, K);
5084 -- begin
5085 -- K (A);
5086 -- end K;
5088 -- Now the contract applies in the normal way to the outer procedure,
5089 -- and the inner procedure has no contracts, so there is no problem
5090 -- in just calling it to get the original effect.
5092 -- In the case of a function, we create an appropriate return statement
5093 -- for the subprogram body that calls the inner procedure.
5097 -- Obtain a copy of the Import_Pragma which belongs to subprogram E
5099 ------------------------
5100 -- Copy_Import_Pragma --
5101 ------------------------
5105 -- The subprogram should have an import pragma, otherwise it does
5106 -- need a wrapper.
5111 -- Save all semantic fields of the pragma
5120 begin
5121 -- Reset all semantic fields. This avoids a potential infinite
5122 -- loop when the pragma comes from an aspect as the duplication
5123 -- will copy the aspect, then copy the corresponding pragma and
5124 -- so on.
5133 -- Restore the original semantic fields
5143 -- Local variables
5154 -- Start of processing for Wrap_Imported_Subprogram
5156 begin
5157 -- Nothing to do if not imported
5162 -- Test enabling conditions for wrapping
5167 and then not GNATprove_Mode
5168 then
5169 -- Here we do the wrap
5171 -- Note on calls to Copy_Separate_Tree. The trees we are copying
5172 -- here are fully analyzed, but we definitely want fully syntactic
5173 -- unanalyzed trees in the body we construct, so that the analysis
5174 -- generates the right visibility, and that is exactly what the
5175 -- calls to Copy_Separate_Tree give us.
5179 -- Fix up spec so it is no longer imported and has convention Ada
5187 -- Grab the subprogram declaration and specification
5191 -- Build parameter list that we need
5200 -- Build the call
5202 -- An imported function whose result type is anonymous access
5203 -- creates a new anonymous access type when it is relocated into
5204 -- the declarations of the body generated below. As a result, the
5205 -- accessibility level of these two anonymous access types may not
5206 -- be compatible even though they are essentially the same type.
5207 -- Use an unchecked type conversion to reconcile this case. Note
5208 -- that the conversion is safe because in the named access type
5209 -- case, both the body and imported function utilize the same
5210 -- type.
5213 Stmt :=
5215 Expression =>
5221 else
5222 Stmt :=
5228 -- Now build the body
5230 Bod :=
5232 Specification =>
5237 Prag),
5238 Handled_Statement_Sequence =>
5243 -- Append the body to freeze result
5248 -- Case of imported subprogram that does not get wrapped
5250 else
5251 -- Set Is_Public. All imported entities need an external symbol
5252 -- created for them since they are always referenced from another
5253 -- object file. Note this used to be set when we set Is_Imported
5254 -- back in Sem_Prag, but now we delay it to this point, since we
5255 -- don't want to set this flag if we wrap an imported subprogram.
5261 -- Start of processing for Freeze_Entity
5263 begin
5264 -- The entity being frozen may be subject to pragma Ghost. Set the mode
5265 -- now to ensure that any nodes generated during freezing are properly
5266 -- flagged as Ghost.
5270 -- We are going to test for various reasons why this entity need not be
5271 -- frozen here, but in the case of an Itype that's defined within a
5272 -- record, that test actually applies to the record.
5278 then
5282 -- Do not freeze if already frozen since we only need one freeze node
5288 -- Do not freeze if we are preanalyzing without freezing
5298 -- It is improper to freeze an external entity within a generic because
5299 -- its freeze node will appear in a non-valid context. The entity will
5300 -- be frozen in the proper scope after the current generic is analyzed.
5301 -- However, aspects must be analyzed because they may be queried later
5302 -- within the generic itself, and the corresponding pragma or attribute
5303 -- definition has not been analyzed yet. After this, indicate that the
5304 -- entity has no further delayed aspects, to prevent a later aspect
5305 -- analysis out of the scope of the generic.
5316 -- AI05-0213: A formal incomplete type does not freeze the actual. In
5317 -- the instance, the same applies to the subtype renaming the actual.
5323 then
5327 -- Formal subprograms are never frozen
5333 -- Generic types are never frozen as they lack delayed semantic checks
5339 -- Do not freeze a global entity within an inner scope created during
5340 -- expansion. A call to subprogram E within some internal procedure
5341 -- (a stream attribute for example) might require freezing E, but the
5342 -- freeze node must appear in the same declarative part as E itself.
5343 -- The two-pass elaboration mechanism in gigi guarantees that E will
5344 -- be frozen before the inner call is elaborated. We exclude constants
5345 -- from this test, because deferred constants may be frozen early, and
5346 -- must be diagnosed (e.g. in the case of a deferred constant being used
5347 -- in a default expression). If the enclosing subprogram comes from
5348 -- source, or is a generic instance, then the freeze point is the one
5349 -- mandated by the language, and we freeze the entity. A subprogram that
5350 -- is a child unit body that acts as a spec does not have a spec that
5351 -- comes from source, but can only come from source.
5356 then
5357 declare
5360 begin
5367 then
5369 else
5379 -- Similarly, an inlined instance body may make reference to global
5380 -- entities, but these references cannot be the proper freezing point
5381 -- for them, and in the absence of inlining freezing will take place in
5382 -- their own scope. Normally instance bodies are analyzed after the
5383 -- enclosing compilation, and everything has been frozen at the proper
5384 -- place, but with front-end inlining an instance body is compiled
5385 -- before the end of the enclosing scope, and as a result out-of-order
5386 -- freezing must be prevented.
5388 elsif Front_End_Inlining
5389 and then In_Instance_Body
5391 then
5392 declare
5395 begin
5400 else
5412 -- Add checks to detect proper initialization of scalars that may appear
5413 -- as subprogram parameters.
5419 -- Deal with delayed aspect specifications. The analysis of the aspect
5420 -- is required to be delayed to the freeze point, thus we analyze the
5421 -- pragma or attribute definition clause in the tree at this point. We
5422 -- also analyze the aspect specification node at the freeze point when
5423 -- the aspect doesn't correspond to pragma/attribute definition clause.
5424 -- In addition, a derived type may have inherited aspects that were
5425 -- delayed in the parent, so these must also be captured now.
5429 then
5433 -- Here to freeze the entity
5437 -- Case of entity being frozen is other than a type
5441 -- If entity is exported or imported and does not have an external
5442 -- name, now is the time to provide the appropriate default name.
5443 -- Skip this if the entity is stubbed, since we don't need a name
5444 -- for any stubbed routine. For the case on intrinsics, if no
5445 -- external name is specified, then calls will be handled in
5446 -- Exp_Intr.Expand_Intrinsic_Call, and no name is needed. If an
5447 -- external name is provided, then Expand_Intrinsic_Call leaves
5448 -- calls in place for expansion by GIGI.
5454 then
5455 Set_Encoded_Interface_Name
5458 -- If entity is an atomic object appearing in a declaration and
5459 -- the expression is an aggregate, assign it to a temporary to
5460 -- ensure that the actual assignment is done atomically rather
5461 -- than component-wise (the assignment to the temp may be done
5462 -- component-wise, but that is harmless).
5469 then
5473 -- Subprogram case
5477 -- Check for needing to wrap imported subprogram
5481 -- Freeze all parameter types and the return type (RM 13.14(14)).
5482 -- However skip this for internal subprograms. This is also where
5483 -- any extra formal parameters are created since we now know
5484 -- whether the subprogram will use a foreign convention.
5486 -- In Ada 2012, freezing a subprogram does not always freeze the
5487 -- corresponding profile (see AI05-019). An attribute reference
5488 -- is not a freezing point of the profile. Flag Do_Freeze_Profile
5489 -- indicates whether the profile should be frozen now.
5490 -- Other constructs that should not freeze ???
5492 -- This processing doesn't apply to internal entities (see below)
5500 -- Must freeze its parent first if it is a derived subprogram
5506 -- We don't freeze internal subprograms, because we don't normally
5507 -- want addition of extra formals or mechanism setting to happen
5508 -- for those. However we do pass through predefined dispatching
5509 -- cases, since extra formals may be needed in some cases, such as
5510 -- for the stream 'Input function (build-in-place formals).
5514 then
5518 -- If warning on suspicious contracts then check for the case of
5519 -- a postcondition other than False for a No_Return subprogram.
5522 and then Warn_On_Suspicious_Contract
5524 then
5525 declare
5529 begin
5532 Name_Post,
5533 Name_Postcondition,
5534 Name_Refined_Post)
5535 then
5536 Exp :=
5537 Expression
5542 then
5543 Error_Msg_NE
5554 -- Here for other than a subprogram or type
5556 else
5557 -- If entity has a type, and it is not a generic unit, then
5558 -- freeze it first (RM 13.14(10)).
5562 then
5565 -- For an object of an anonymous array type, aspects on the
5566 -- object declaration apply to the type itself. This is the
5567 -- case for Atomic_Components, Volatile_Components, and
5568 -- Independent_Components. In these cases analysis of the
5569 -- generated pragma will mark the anonymous types accordingly,
5570 -- and the object itself does not require a freeze node.
5576 then
5583 -- Special processing for objects created by object declaration
5589 -- Check that a constant which has a pragma Volatile[_Components]
5590 -- or Atomic[_Components] also has a pragma Import (RM C.6(13)).
5592 -- Note: Atomic[_Components] also sets Volatile[_Components]
5598 then
5599 -- Make sure we actually have a pragma, and have not merely
5600 -- inherited the indication from elsewhere (e.g. an address
5601 -- clause, which is not good enough in RM terms).
5604 or else
5606 then
5607 Error_Msg_N
5612 or else
5614 then
5615 Error_Msg_N
5621 -- Static objects require special handling
5625 then
5629 -- Remaining step is to layout objects
5633 then
5637 -- For an object that does not have delayed freezing, and whose
5638 -- initialization actions have been captured in a compound
5639 -- statement, move them back now directly within the enclosing
5640 -- statement sequence.
5644 then
5648 -- Do not generate a freeze node for a generic unit
5656 -- Case of a type or subtype being frozen
5658 else
5659 -- Verify several SPARK legality rules related to Ghost types now
5660 -- that the type is frozen.
5664 -- We used to check here that a full type must have preelaborable
5665 -- initialization if it completes a private type specified with
5666 -- pragma Preelaborable_Initialization, but that missed cases where
5667 -- the types occur within a generic package, since the freezing
5668 -- that occurs within a containing scope generally skips traversal
5669 -- of a generic unit's declarations (those will be frozen within
5670 -- instances). This check was moved to Analyze_Package_Specification.
5672 -- The type may be defined in a generic unit. This can occur when
5673 -- freezing a generic function that returns the type (which is
5674 -- defined in a parent unit). It is clearly meaningless to freeze
5675 -- this type. However, if it is a subtype, its size may be determi-
5676 -- nable and used in subsequent checks, so might as well try to
5677 -- compute it.
5679 -- In Ada 2012, Freeze_Entities is also used in the front end to
5680 -- trigger the analysis of aspect expressions, so in this case we
5681 -- want to continue the freezing process.
5683 -- Is_Generic_Unit (Scope (E)) is dubious here, do we want instead
5684 -- In_Generic_Scope (E)???
5688 and then
5691 then
5697 -- Check for error of Type_Invariant'Class applied to an untagged
5698 -- type (check delayed to freeze time when full type is available).
5700 declare
5702 begin
5706 then
5707 Error_Msg_NE
5709 Error_Msg_N
5714 -- Deal with special cases of freezing for subtype
5718 -- Before we do anything else, a specific test for the case of a
5719 -- size given for an array where the array would need to be packed
5720 -- in order for the size to be honored, but is not. This is the
5721 -- case where implicit packing may apply. The reason we do this so
5722 -- early is that, if we have implicit packing, the layout of the
5723 -- base type is affected, so we must do this before we freeze the
5724 -- base type.
5726 -- We could do this processing only if implicit packing is enabled
5727 -- since in all other cases, the error would be caught by the back
5728 -- end. However, we choose to do the check even if we do not have
5729 -- implicit packing enabled, since this allows us to give a more
5730 -- useful error message (advising use of pragma Implicit_Packing
5731 -- or pragma Pack).
5734 declare
5746 -- Number of elements in array
5748 begin
5749 -- Check enabling conditions. These are straightforward
5750 -- except for the test for a limited composite type. This
5751 -- eliminates the rare case of a array of limited components
5752 -- where there are issues of whether or not we can go ahead
5753 -- and pack the array (since we can't freely pack and unpack
5754 -- arrays if they are limited).
5756 -- Note that we check the root type explicitly because the
5757 -- whole point is we are doing this test before we have had
5758 -- a chance to freeze the base type (and it is that freeze
5759 -- action that causes stuff to be inherited).
5761 -- The conditions on the size are identical to those used in
5762 -- Freeze_Array_Type to set the Is_Packed flag.
5780 then
5781 -- Compute number of elements in array
5788 and then
5790 then
5798 else
5805 -- What we are looking for here is the situation where
5806 -- the RM_Size given would be exactly right if there was
5807 -- a pragma Pack, resulting in the component size being
5808 -- the RM_Size of the component type.
5812 -- For implicit packing mode, just set the component
5813 -- size and Freeze_Array_Type will do the rest.
5818 -- Otherwise give an error message
5820 else
5821 Error_Msg_NE
5823 Error_Msg_N -- CODEFIX
5834 -- If ancestor subtype present, freeze that first. Note that this
5835 -- will also get the base type frozen. Need RM reference ???
5842 -- No ancestor subtype present
5844 else
5845 -- See if we have a nearest ancestor that has a predicate.
5846 -- That catches the case of derived type with a predicate.
5847 -- Need RM reference here ???
5855 -- Freeze base type before freezing the entity (RM 13.14(15))
5862 -- A subtype inherits all the type-related representation aspects
5863 -- from its parents (RM 13.1(8)).
5867 -- For a derived type, freeze its parent type first (RM 13.14(15))
5873 -- A derived type inherits each type-related representation aspect
5874 -- of its parent type that was directly specified before the
5875 -- declaration of the derived type (RM 13.1(15)).
5880 -- Check for incompatible size and alignment for record type
5882 if Warn_On_Size_Alignment
5886 -- If explicit Object_Size clause given assume that the programmer
5887 -- knows what he is doing, and expects the compiler behavior.
5891 -- Check for size not a multiple of alignment
5894 then
5895 declare
5901 begin
5904 -- Give a warning
5908 Error_Msg_NE
5915 else
5917 Error_Msg_NE
5931 -- Array type
5936 -- For a class-wide type, the corresponding specific type is
5937 -- frozen as well (RM 13.14(15))
5942 -- If the base type of the class-wide type is still incomplete,
5943 -- the class-wide remains unfrozen as well. This is legal when
5944 -- E is the formal of a primitive operation of some other type
5945 -- which is being frozen.
5952 -- The equivalent type associated with a class-wide subtype needs
5953 -- to be frozen to ensure that its layout is done.
5957 then
5961 -- Generate an itype reference for a library-level class-wide type
5962 -- at the freeze point. Otherwise the first explicit reference to
5963 -- the type may appear in an inner scope which will be rejected by
5964 -- the back-end.
5968 then
5969 declare
5972 begin
5975 -- From a gigi point of view, a class-wide subtype derives
5976 -- from its record equivalent type. As a result, the itype
5977 -- reference must appear after the freeze node of the
5978 -- equivalent type or gigi will reject the reference.
5982 then
5984 else
5990 -- For a record type or record subtype, freeze all component types
5991 -- (RM 13.14(15)). We test for E_Record_(sub)Type here, rather than
5992 -- using Is_Record_Type, because we don't want to attempt the freeze
5993 -- for the case of a private type with record extension (we will do
5994 -- that later when the full type is frozen).
6001 -- Report a warning if a discriminated record base type has a
6002 -- convention with language C or C++ applied to it. This check is
6003 -- done even within generic scopes (but not in instantiations),
6004 -- which is why we don't do it as part of Freeze_Record_Type.
6008 -- For a concurrent type, freeze corresponding record type. This does
6009 -- not correspond to any specific rule in the RM, but the record type
6010 -- is essentially part of the concurrent type. Also freeze all local
6011 -- entities. This includes record types created for entry parameter
6012 -- blocks and whatever local entities may appear in the private part.
6026 -- The guard on the presence of the Etype seems to be needed
6027 -- for some CodePeer (-gnatcC) cases, but not clear why???
6032 then
6043 -- Private types are required to point to the same freeze node as
6044 -- their corresponding full views. The freeze node itself has to
6045 -- point to the partial view of the entity (because from the partial
6046 -- view, we can retrieve the full view, but not the reverse).
6047 -- However, in order to freeze correctly, we need to freeze the full
6048 -- view. If we are freezing at the end of a scope (or within the
6049 -- scope) of the private type, the partial and full views will have
6050 -- been swapped, the full view appears first in the entity chain and
6051 -- the swapping mechanism ensures that the pointers are properly set
6052 -- (on scope exit).
6054 -- If we encounter the partial view before the full view (e.g. when
6055 -- freezing from another scope), we freeze the full view, and then
6056 -- set the pointers appropriately since we cannot rely on swapping to
6057 -- fix things up (subtypes in an outer scope might not get swapped).
6059 -- If the full view is itself private, the above requirements apply
6060 -- to the underlying full view instead of the full view. But there is
6061 -- no swapping mechanism for the underlying full view so we need to
6062 -- set the pointers appropriately in both cases.
6066 then
6067 -- The construction of the dispatch table associated with library
6068 -- level tagged types forces freezing of all the primitives of the
6069 -- type, which may cause premature freezing of the partial view.
6070 -- For example:
6072 -- package Pkg is
6073 -- type T is tagged private;
6074 -- type DT is new T with private;
6075 -- procedure Prim (X : in out T; Y : in out DT'Class);
6076 -- private
6077 -- type T is tagged null record;
6078 -- Obj : T;
6079 -- type DT is new T with null record;
6080 -- end;
6082 -- In this case the type will be frozen later by the usual
6083 -- mechanism: an object declaration, an instantiation, or the
6084 -- end of a declarative part.
6088 then
6092 -- Case of full view present
6096 -- If full view has already been frozen, then no further
6097 -- processing is required
6103 -- Otherwise freeze full view and patch the pointers so that
6104 -- the freeze node will elaborate both views in the back end.
6105 -- However, if full view is itself private, freeze underlying
6106 -- full view instead and patch the pointers so that the freeze
6107 -- node will elaborate the three views in the back end.
6109 else
6110 declare
6113 begin
6116 then
6124 then
6128 Inherit_Freeze_Node
6131 else
6141 Inherit_Freeze_Node
6144 else
6145 -- {Incomplete,Private}_Subtypes with Full_Views
6146 -- constrained by discriminants.
6157 -- AI-117 requires that the convention of a partial view be the
6158 -- same as the convention of the full view. Note that this is a
6159 -- recognized breach of privacy, but it's essential for logical
6160 -- consistency of representation, and the lack of a rule in
6161 -- RM95 was an oversight.
6168 -- Size information is copied from the full view to the
6169 -- incomplete or private view for consistency.
6171 -- We skip this is the full view is not a type. This is very
6172 -- strange of course, and can only happen as a result of
6173 -- certain illegalities, such as a premature attempt to derive
6174 -- from an incomplete type.
6183 -- Case of underlying full view present
6187 then
6192 -- Patch the pointers so that the freeze node will elaborate
6193 -- both views in the back end.
6199 Inherit_Freeze_Node
6202 else
6212 -- Case of no full view present. If entity is derived or subtype,
6213 -- it is safe to freeze, correctness depends on the frozen status
6214 -- of parent. Otherwise it is either premature usage, or a Taft
6215 -- amendment type, so diagnosis is at the point of use and the
6216 -- type might be frozen later.
6221 else
6227 -- For access subprogram, freeze types of all formals, the return
6228 -- type was already frozen, since it is the Etype of the function.
6229 -- Formal types can be tagged Taft amendment types, but otherwise
6230 -- they cannot be incomplete.
6237 then
6241 -- AI05-151: Incomplete types are allowed in access to
6242 -- subprogram specifications.
6245 Error_Msg_NE
6256 -- For access to a protected subprogram, freeze the equivalent type
6257 -- (however this is not set if we are not generating code or if this
6258 -- is an anonymous type used just for resolution).
6266 -- Generic types are never seen by the back-end, and are also not
6267 -- processed by the expander (since the expander is turned off for
6268 -- generic processing), so we never need freeze nodes for them.
6274 -- Some special processing for non-generic types to complete
6275 -- representation details not known till the freeze point.
6280 -- Some error checks required for ordinary fixed-point type. Defer
6281 -- these till the freeze-point since we need the small and range
6282 -- values. We only do these checks for base types
6287 Error_Msg_N
6292 Error_Msg_N
6298 Error_Msg_N
6304 Error_Msg_N
6316 and then Warn_On_Suspicious_Modulus_Value
6317 then
6321 -- The pool applies to named and anonymous access types, but not
6322 -- to subprogram and to internal types generated for 'Access
6323 -- references.
6328 then
6329 -- If a pragma Default_Storage_Pool applies, and this type has no
6330 -- Storage_Pool or Storage_Size clause (which must have occurred
6331 -- before the freezing point), then use the default. This applies
6332 -- only to base types.
6334 -- None of this applies to access to subprograms, for which there
6335 -- are clearly no pools.
6341 then
6342 -- Case of pragma Default_Storage_Pool (null)
6347 -- Case of pragma Default_Storage_Pool (storage_pool_NAME)
6349 else
6354 -- Check restriction for standard storage pool
6360 -- Deal with error message for pure access type. This is not an
6361 -- error in Ada 2005 if there is no pool (see AI-366).
6367 then
6371 Error_Msg_N
6375 Error_Msg_N
6378 else
6379 Error_Msg_N
6386 -- Case of composite types
6390 -- AI-117 requires that all new primitives of a tagged type must
6391 -- inherit the convention of the full view of the type. Inherited
6392 -- and overriding operations are defined to inherit the convention
6393 -- of their parent or overridden subprogram (also specified in
6394 -- AI-117), which will have occurred earlier (in Derive_Subprogram
6395 -- and New_Overloaded_Entity). Here we set the convention of
6396 -- primitives that are still convention Ada, which will ensure
6397 -- that any new primitives inherit the type's convention. Class-
6398 -- wide types can have a foreign convention inherited from their
6399 -- specific type, but are excluded from this since they don't have
6400 -- any associated primitives.
6405 then
6406 declare
6410 begin
6422 -- If the type is a simple storage pool type, then this is where
6423 -- we attempt to locate and validate its Allocate, Deallocate, and
6424 -- Storage_Size operations (the first is required, and the latter
6425 -- two are optional). We also verify that the full type for a
6426 -- private type is allowed to be a simple storage pool type.
6430 then
6431 -- If the type is marked Has_Private_Declaration, then this is
6432 -- a full type for a private type that was specified with the
6433 -- pragma Simple_Storage_Pool_Type, and here we ensure that the
6434 -- pragma is allowed for the full type (for example, it can't
6435 -- be an array type, or a nonlimited record type).
6440 then
6442 Error_Msg_N
6453 procedure Validate_Simple_Pool_Op_Formal
6460 -- Validate one formal Pool_Op_Formal of the candidate pool
6461 -- operation Pool_Op. The formal must be of Expected_Type
6462 -- and have mode Expected_Mode. OK_Formal will be set to
6463 -- False if the formal doesn't match. If OK_Formal is False
6464 -- on entry, then the formal will effectively be ignored
6465 -- (because validation of the pool op has already failed).
6466 -- Upon return, Pool_Op_Formal will be updated to the next
6467 -- formal, if any.
6469 procedure Validate_Simple_Pool_Operation
6471 -- Search for and validate a simple pool operation with the
6472 -- name Op_Name. If the name is Allocate, then there must be
6473 -- exactly one such primitive operation for the simple pool
6474 -- type. If the name is Deallocate or Storage_Size, then
6475 -- there can be at most one such primitive operation. The
6476 -- profile of the located primitive must conform to what
6477 -- is expected for each operation.
6479 ------------------------------------
6480 -- Validate_Simple_Pool_Op_Formal --
6481 ------------------------------------
6483 procedure Validate_Simple_Pool_Op_Formal
6490 is
6491 begin
6492 -- If OK_Formal is False on entry, then simply ignore
6493 -- the formal, because an earlier formal has already
6494 -- been flagged.
6499 -- If no formal is passed in, then issue an error for a
6500 -- missing formal.
6503 Error_Msg_NE
6513 -- If the pool type was expected for this formal, then
6514 -- this will not be considered a candidate operation
6515 -- for the simple pool, so we unset OK_Formal so that
6516 -- the op and any later formals will be ignored.
6523 else
6524 Error_Msg_NE
6531 -- Issue error if formal's mode is not the expected one
6534 Error_Msg_N
6536 Pool_Op_Formal);
6539 -- Advance to the next formal
6544 ------------------------------------
6545 -- Validate_Simple_Pool_Operation --
6546 ------------------------------------
6548 procedure Validate_Simple_Pool_Operation
6550 is
6556 begin
6557 pragma Assert
6559 Name_Deallocate,
6560 Name_Storage_Size));
6564 -- For each homonym declared immediately in the scope
6565 -- of the simple storage pool type, determine whether
6566 -- the homonym is an operation of the pool type, and,
6567 -- if so, check that its profile is as expected for
6568 -- a simple pool operation of that name.
6574 then
6579 -- The first parameter must be of the pool type
6580 -- in order for the operation to qualify.
6583 Validate_Simple_Pool_Op_Formal
6586 else
6587 Validate_Simple_Pool_Op_Formal
6592 -- If another operation with this name has already
6593 -- been located for the type, then flag an error,
6594 -- since we only allow the type to have a single
6595 -- such primitive.
6598 Error_Msg_NE
6603 -- In the case of Allocate and Deallocate, a formal
6604 -- of type System.Address is required.
6607 Validate_Simple_Pool_Op_Formal
6612 Validate_Simple_Pool_Op_Formal
6617 -- In the case of Allocate and Deallocate, formals
6618 -- of type Storage_Count are required as the third
6619 -- and fourth parameters.
6622 Validate_Simple_Pool_Op_Formal
6625 Validate_Simple_Pool_Op_Formal
6630 -- If no mismatched formals have been found (Is_OK)
6631 -- and no excess formals are present, then this
6632 -- operation has been validated, so record it.
6642 -- There must be a valid Allocate operation for the type,
6643 -- so issue an error if none was found.
6647 then
6653 -- Simple pool operations can't be abstract
6656 Error_Msg_N
6661 -- The Storage_Size operation must be a function with
6662 -- Storage_Count as its result type.
6666 Error_Msg_N
6670 Error_Msg_NE
6675 -- Allocate and Deallocate must be procedures
6678 Error_Msg_N
6684 -- Start of processing for Validate_Simple_Pool_Ops
6686 begin
6694 -- Now that all types from which E may depend are frozen, see if the
6695 -- size is known at compile time, if it must be unsigned, or if
6696 -- strict alignment is required
6705 -- Do not allow a size clause for a type which does not have a size
6706 -- that is known at compile time
6710 then
6711 -- Suppress this message if errors posted on E, even if we are
6712 -- in all errors mode, since this is often a junk message
6715 Error_Msg_N
6721 -- Now we set/verify the representation information, in particular
6722 -- the size and alignment values. This processing is not required for
6723 -- generic types, since generic types do not play any part in code
6724 -- generation, and so the size and alignment values for such types
6725 -- are irrelevant. Ditto for types declared within a generic unit,
6726 -- which may have components that depend on generic parameters, and
6727 -- that will be recreated in an instance.
6732 -- Otherwise we call the layout procedure
6734 else
6738 -- If this is an access to subprogram whose designated type is itself
6739 -- a subprogram type, the return type of this anonymous subprogram
6740 -- type must be decorated as well.
6744 then
6748 -- If the type has a Defaut_Value/Default_Component_Value aspect,
6749 -- this is where we analye the expression (after the type is frozen,
6750 -- since in the case of Default_Value, we are analyzing with the
6751 -- type itself, and we treat Default_Component_Value similarly for
6752 -- the sake of uniformity).
6755 declare
6760 begin
6765 else
6776 Flag_Non_Static_Expr
6783 -- End of freeze processing for type entities
6786 -- Here is where we logically freeze the current entity. If it has a
6787 -- freeze node, then this is the point at which the freeze node is
6788 -- linked into the result list.
6792 -- If a freeze node is already allocated, use it, otherwise allocate
6793 -- a new one. The preallocation happens in the case of anonymous base
6794 -- types, where we preallocate so that we can set First_Subtype_Link.
6795 -- Note that we reset the Sloc to the current freeze location.
6801 else
6812 -- A final pass over record types with discriminants. If the type
6813 -- has an incomplete declaration, there may be constrained access
6814 -- subtypes declared elsewhere, which do not depend on the discrimi-
6815 -- nants of the type, and which are used as component types (i.e.
6816 -- the full view is a recursive type). The designated types of these
6817 -- subtypes can only be elaborated after the type itself, and they
6818 -- need an itype reference.
6821 declare
6826 begin
6836 then
6848 -- When a type is frozen, the first subtype of the type is frozen as
6849 -- well (RM 13.14(15)). This has to be done after freezing the type,
6850 -- since obviously the first subtype depends on its own base type.
6855 -- If we just froze a tagged non-class wide record, then freeze the
6856 -- corresponding class-wide type. This must be done after the tagged
6857 -- type itself is frozen, because the class-wide type refers to the
6858 -- tagged type which generates the class.
6863 then
6870 -- Special handling for subprograms
6874 -- If subprogram has address clause then reset Is_Public flag, since
6875 -- we do not want the backend to generate external references.
6879 then
6890 -----------------------------
6891 -- Freeze_Enumeration_Type --
6892 -----------------------------
6895 begin
6896 -- By default, if no size clause is present, an enumeration type with
6897 -- Convention C is assumed to interface to a C enum and has integer
6898 -- size, except for a boolean type because it is assumed to interface
6899 -- to _Bool introduced in C99. This applies to types. For subtypes,
6900 -- verify that its base type has no size clause either. Treat other
6901 -- foreign conventions in the same way, and also make sure alignment
6902 -- is set right.
6910 -- Don't do this if Short_Enums on target
6912 and then not Target_Short_Enums
6913 then
6917 -- Normal Ada case or size clause present or not Long_C_Enums on target
6919 else
6920 -- If the enumeration type interfaces to C, and it has a size clause
6921 -- that specifies less than int size, it warrants a warning. The
6922 -- user may intend the C type to be an enum or a char, so this is
6923 -- not by itself an error that the Ada compiler can detect, but it
6924 -- it is a worth a heads-up. For Boolean and Character types we
6925 -- assume that the programmer has the proper C type in mind.
6933 -- Don't do this if Short_Enums on target
6935 and then not Target_Short_Enums
6936 then
6937 Error_Msg_N
6945 -----------------------
6946 -- Freeze_Expression --
6947 -----------------------
6952 -- If the expression is an array aggregate, the type of the component
6953 -- expressions is also frozen. If the component type is an access type
6954 -- and the expressions include allocators, the designed type is frozen
6955 -- as well.
6958 -- Given an N_Handled_Sequence_Of_Statements node N, determines whether
6959 -- it is the handled statement sequence of an expander-generated
6960 -- subprogram (init proc, stream subprogram, or renaming as body).
6961 -- If so, this is not a freezing context.
6963 -----------------------------------------
6964 -- Find_Aggregate_Component_Desig_Type --
6965 -----------------------------------------
6971 begin
6997 ----------------------
6998 -- In_Expanded_Body --
6999 ----------------------
7005 begin
7008 else
7015 else
7018 -- The following are expander-created bodies, or bodies that
7019 -- are not freeze points.
7028 N_Subprogram_Renaming_Declaration,
7029 N_Expression_Function))
7030 then
7032 else
7038 -- Local variables
7049 -- This flag is set true if the entity must be frozen outside the
7050 -- current subprogram. This happens in the case of expander generated
7051 -- subprograms (_Init_Proc, _Input, _Output, _Read, _Write) which do
7052 -- not freeze all entities like other bodies, but which nevertheless
7053 -- may reference entities that have to be frozen before the body and
7054 -- obviously cannot be frozen inside the body.
7057 -- This entity is set if we are inside a subprogram body and the frozen
7058 -- entity is defined in the enclosing scope of this subprogram. In such
7059 -- case we must skip the subprogram body when climbing the parents chain
7060 -- to locate the correct placement for the freezing node.
7062 -- Start of processing for Freeze_Expression
7064 begin
7065 -- Immediate return if freezing is inhibited. This flag is set by the
7066 -- analyzer to stop freezing on generated expressions that would cause
7067 -- freezing if they were in the source program, but which are not
7068 -- supposed to freeze, since they are created.
7074 -- If expression is non-static, then it does not freeze in a default
7075 -- expression, see section "Handling of Default Expressions" in the
7076 -- spec of package Sem for further details. Note that we have to make
7077 -- sure that we actually have a real expression (if we have a subtype
7078 -- indication, we can't test Is_OK_Static_Expression). However, we
7079 -- exclude the case of the prefix of an attribute of a static scalar
7080 -- subtype from this early return, because static subtype attributes
7081 -- should always cause freezing, even in default expressions, but
7082 -- the attribute may not have been marked as static yet (because in
7083 -- Resolve_Attribute, the call to Eval_Attribute follows the call of
7084 -- Freeze_Expression on the prefix).
7086 if In_Spec_Exp
7093 then
7097 -- Freeze type of expression if not frozen already
7105 -- Base type may be an derived numeric type that is frozen at the
7106 -- point of declaration, but first_subtype is still unfrozen.
7113 -- For entity name, freeze entity if not frozen already. A special
7114 -- exception occurs for an identifier that did not come from source.
7115 -- We don't let such identifiers freeze a non-internal entity, i.e.
7116 -- an entity that did come from source, since such an identifier was
7117 -- generated by the expander, and cannot have any semantic effect on
7118 -- the freezing semantics. For example, this stops the parameter of
7119 -- an initialization procedure from freezing the variable.
7126 then
7133 else
7137 -- For an allocator freeze designated type if not frozen already
7139 -- For an aggregate whose component type is an access type, freeze the
7140 -- designated type now, so that its freeze does not appear within the
7141 -- loop that might be created in the expansion of the aggregate. If the
7142 -- designated type is a private type without full view, the expression
7143 -- cannot contain an allocator, so the type is not frozen.
7145 -- For a function, we freeze the entity when the subprogram declaration
7146 -- is frozen, but a function call may appear in an initialization proc.
7147 -- before the declaration is frozen. We need to generate the extra
7148 -- formals, if any, to ensure that the expansion of the call includes
7149 -- the proper actuals. This only applies to Ada subprograms, not to
7150 -- imported ones.
7161 then
7162 -- Check whether aggregate includes allocators
7167 when N_Indexed_Component
7168 | N_Selected_Component
7169 | N_Slice
7170 =>
7180 then
7191 then
7195 -- All done if nothing needs freezing
7200 then
7204 -- Check if we are inside a subprogram body and the frozen entity is
7205 -- defined in the enclosing scope of this subprogram. In such case we
7206 -- must skip the subprogram when climbing the parents chain to locate
7207 -- the correct placement for the freezing node.
7209 -- This is not needed for default expressions and other spec expressions
7210 -- in generic units since the Move_Freeze_Nodes mechanism (sem_ch12.adb)
7211 -- takes care of placing them at the proper place, after the generic
7212 -- unit.
7217 then
7218 declare
7221 begin
7224 loop
7238 -- Examine the enclosing context by climbing the parent chain
7240 -- If we identified that we must freeze the entity outside of a given
7241 -- subprogram then we just climb up to that subprogram checking if some
7242 -- enclosing node is marked as Must_Not_Freeze (since in such case we
7243 -- must not freeze yet this entity).
7248 loop
7249 -- Do not freeze the current expression if another expression in
7250 -- the chain of parents must not be frozen.
7258 -- If we don't have a parent, then we are not in a well-formed
7259 -- tree. This is an unusual case, but there are some legitimate
7260 -- situations in which this occurs, notably when the expressions
7261 -- in the range of a type declaration are resolved. We simply
7262 -- ignore the freeze request in this case.
7268 exit when
7271 Freeze_Outside_Subp;
7276 -- Otherwise the traversal serves two purposes - to detect scenarios
7277 -- where freezeing is not needed and to find the proper insertion point
7278 -- for the freeze nodes. Although somewhat similar to Insert_Actions,
7279 -- this traversal is freezing semantics-sensitive. Inserting freeze
7280 -- nodes blindly in the tree may result in types being frozen too early.
7282 else
7283 loop
7284 -- Do not freeze the current expression if another expression in
7285 -- the chain of parents must not be frozen.
7293 -- If we don't have a parent, then we are not in a well-formed
7294 -- tree. This is an unusual case, but there are some legitimate
7295 -- situations in which this occurs, notably when the expressions
7296 -- in the range of a type declaration are resolved. We simply
7297 -- ignore the freeze request in this case. Is this right ???
7303 -- See if we have got to an appropriate point in the tree
7307 -- A special test for the exception of (RM 13.14(8)) for the
7308 -- case of per-object expressions (RM 3.8(18)) occurring in
7309 -- component definition or a discrete subtype definition. Note
7310 -- that we test for a component declaration which includes both
7311 -- cases we are interested in, and furthermore the tree does
7312 -- not have explicit nodes for either of these two constructs.
7316 -- The case we want to test for here is an identifier that
7317 -- is a per-object expression, this is either a discriminant
7318 -- that appears in a context other than the component
7319 -- declaration or it is a reference to the type of the
7320 -- enclosing construct.
7322 -- For either of these cases, we skip the freezing
7324 if not In_Spec_Expression
7327 then
7328 -- We recognize the discriminant case by just looking for
7329 -- a reference to a discriminant. It can only be one for
7330 -- the enclosing construct. Skip freezing in this case.
7335 -- For the case of a reference to the enclosing record,
7336 -- (or task or protected type), we look for a type that
7337 -- matches the current scope.
7344 -- If we have an enumeration literal that appears as the choice
7345 -- in the aggregate of an enumeration representation clause,
7346 -- then freezing does not occur (RM 13.14(10)).
7350 -- The case we are looking for is an enumeration literal
7354 then
7355 -- If enumeration literal appears directly as the choice,
7356 -- do not freeze (this is the normal non-overloaded case)
7360 then
7363 -- If enumeration literal appears as the name of function
7364 -- which is the choice, then also do not freeze. This
7365 -- happens in the overloaded literal case, where the
7366 -- enumeration literal is temporarily changed to a
7367 -- function call for overloading analysis purposes.
7371 N_Component_Association
7374 then
7379 -- Normally if the parent is a handled sequence of statements,
7380 -- then the current node must be a statement, and that is an
7381 -- appropriate place to insert a freeze node.
7385 -- An exception occurs when the sequence of statements is
7386 -- for an expander generated body that did not do the usual
7387 -- freeze all operation. In this case we usually want to
7388 -- freeze outside this body, not inside it, and we skip
7389 -- past the subprogram body that we are inside.
7392 declare
7396 begin
7397 -- Freeze the entity only when it is declared inside
7398 -- the body of the expander generated procedure.
7399 -- This case is recognized by the scope of the entity
7400 -- or its type, which is either the spec for some
7401 -- enclosing body, or (in the case of init_procs,
7402 -- for which there are no separate specs) the current
7403 -- scope.
7409 or else
7411 then
7417 then
7422 -- An expression function may act as a completion of
7423 -- a function declaration. As such, it can reference
7424 -- entities declared between the two views:
7426 -- Hidden []; -- 1
7427 -- function F return ...;
7428 -- private
7429 -- function Hidden return ...;
7430 -- function F return ... is (Hidden); -- 2
7432 -- Refering to the example above, freezing the
7433 -- expression of F (2) would place Hidden's freeze
7434 -- node (1) in the wrong place. Avoid explicit
7435 -- freezing and let the usual scenarios do the job
7436 -- (for example, reaching the end of the private
7437 -- declarations, or a call to F.)
7440 then
7443 -- Freeze outside the body
7445 else
7451 -- Here if normal case where we are in handled statement
7452 -- sequence and want to do the insertion right there.
7454 else
7458 -- If parent is a body or a spec or a block, then the current
7459 -- node is a statement or declaration and we can insert the
7460 -- freeze node before it.
7462 when N_Block_Statement
7463 | N_Entry_Body
7464 | N_Package_Body
7465 | N_Package_Specification
7466 | N_Protected_Body
7467 | N_Subprogram_Body
7468 | N_Task_Body
7469 =>
7472 -- The expander is allowed to define types in any statements
7473 -- list, so any of the following parent nodes also mark a
7474 -- freezing point if the actual node is in a list of
7475 -- statements or declarations.
7477 when N_Abortable_Part
7478 | N_Accept_Alternative
7479 | N_And_Then
7480 | N_Case_Statement_Alternative
7481 | N_Compilation_Unit_Aux
7482 | N_Conditional_Entry_Call
7483 | N_Delay_Alternative
7484 | N_Elsif_Part
7485 | N_Entry_Call_Alternative
7486 | N_Exception_Handler
7487 | N_Extended_Return_Statement
7488 | N_Freeze_Entity
7489 | N_If_Statement
7490 | N_Or_Else
7491 | N_Selective_Accept
7492 | N_Triggering_Alternative
7493 =>
7496 -- Freeze nodes produced by an expression coming from the
7497 -- Actions list of a N_Expression_With_Actions node must remain
7498 -- within the Actions list. Inserting the freeze nodes further
7499 -- up the tree may lead to use before declaration issues in the
7500 -- case of array types.
7505 then
7509 -- Note: N_Loop_Statement is a special case. A type that
7510 -- appears in the source can never be frozen in a loop (this
7511 -- occurs only because of a loop expanded by the expander), so
7512 -- we keep on going. Otherwise we terminate the search. Same
7513 -- is true of any entity which comes from source. (if they
7514 -- have predefined type, that type does not appear to come
7515 -- from source, but the entity should not be frozen here).
7521 -- For all other cases, keep looking at parents
7527 -- We fall through the case if we did not yet find the proper
7528 -- place in the free for inserting the freeze node, so climb.
7534 -- If the expression appears in a record or an initialization procedure,
7535 -- the freeze nodes are collected and attached to the current scope, to
7536 -- be inserted and analyzed on exit from the scope, to insure that
7537 -- generated entities appear in the correct scope. If the expression is
7538 -- a default for a discriminant specification, the scope is still void.
7539 -- The expression can also appear in the discriminant part of a private
7540 -- or concurrent type.
7542 -- If the expression appears in a constrained subcomponent of an
7543 -- enclosing record declaration, the freeze nodes must be attached to
7544 -- the outer record type so they can eventually be placed in the
7545 -- enclosing declaration list.
7547 -- The other case requiring this special handling is if we are in a
7548 -- default expression, since in that case we are about to freeze a
7549 -- static type, and the freeze scope needs to be the outer scope, not
7550 -- the scope of the subprogram with the default parameter.
7552 -- For default expressions and other spec expressions in generic units,
7553 -- the Move_Freeze_Nodes mechanism (see sem_ch12.adb) takes care of
7554 -- placing them at the proper place, after the generic unit.
7557 or else Freeze_Outside
7562 then
7563 declare
7568 begin
7581 -- The current scope may be that of a constrained component of
7582 -- an enclosing record declaration, or of a loop of an enclosing
7583 -- quantified expression, which is above the current scope in the
7584 -- scope stack. Indeed in the context of a quantified expression,
7585 -- a scope is created and pushed above the current scope in order
7586 -- to emulate the loop-like behavior of the quantified expression.
7587 -- If the expression is within a top-level pragma, as for a pre-
7588 -- condition on a library-level subprogram, nothing to do.
7593 N_Quantified_Expression)
7594 then
7601 Freeze_Nodes;
7602 else
7612 -- Now we have the right place to do the freezing. First, a special
7613 -- adjustment, if we are in spec-expression analysis mode, these freeze
7614 -- actions must not be thrown away (normally all inserted actions are
7615 -- thrown away in this mode. However, the freeze actions are from static
7616 -- expressions and one of the important reasons we are doing this
7617 -- special analysis is to get these freeze actions. Therefore we turn
7618 -- off the In_Spec_Expression mode to propagate these freeze actions.
7619 -- This also means they get properly analyzed and expanded.
7623 -- Freeze the designated type of an allocator (RM 13.14(13))
7629 -- Freeze type of expression (RM 13.14(10)). Note that we took care of
7630 -- the enumeration representation clause exception in the loop above.
7636 -- Freeze name if one is present (RM 13.14(11))
7642 -- Restore In_Spec_Expression flag
7647 -----------------------
7648 -- Freeze_Expr_Types --
7649 -----------------------
7651 procedure Freeze_Expr_Types
7656 is
7658 -- Build a duplicate of the expression of the return statement that has
7659 -- no defining entities shared with the original expression.
7662 -- Freeze all types referenced in the subtree rooted at Node
7664 -----------------------
7665 -- Cloned_Expression --
7666 -----------------------
7670 -- Tree traversal routine that clones the defining identifier of
7671 -- iterator and loop parameter specification nodes.
7673 --------------
7674 -- Clone_Id --
7675 --------------
7678 begin
7680 N_Loop_Parameter_Specification)
7681 then
7682 Set_Defining_Identifier
7691 -- Local variable
7695 -- Start of processing for Cloned_Expression
7697 begin
7698 -- We must duplicate the expression with semantic information to
7699 -- inherit the decoration of global entities in generic instances.
7700 -- Set the parent of the new node to be the parent of the original
7701 -- to get the proper context, which is needed for complete error
7702 -- reporting and for semantic analysis.
7706 -- Replace the defining identifier of iterators and loop param
7707 -- specifications by a clone to ensure that the cloned expression
7708 -- and the original expression don't have shared identifiers;
7709 -- otherwise, as part of the preanalysis of the expression, these
7710 -- shared identifiers may be left decorated with itypes which
7711 -- will not be available in the tree passed to the backend.
7718 ----------------------
7719 -- Freeze_Type_Refs --
7720 ----------------------
7724 -- Check that Typ is fully declared and freeze it if so
7726 ---------------------------
7727 -- Check_And_Freeze_Type --
7728 ---------------------------
7731 begin
7732 -- Skip Itypes created by the preanalysis, and itypes whose
7733 -- scope is another type (i.e. component subtypes that depend
7734 -- on a discriminant),
7739 then
7743 -- This provides a better error message than generating primitives
7744 -- whose compilation fails much later. Refine the error message if
7745 -- possible.
7752 then
7756 else
7761 -- Start of processing for Freeze_Type_Refs
7763 begin
7764 -- Check that a type referenced by an entity can be frozen
7769 -- Check that the enclosing record type can be frozen
7775 -- Freezing an access type does not freeze the designated type, but
7776 -- freezing conversions between access to interfaces requires that
7777 -- the interface types themselves be frozen, so that dispatch table
7778 -- entities are properly created.
7780 -- Unclear whether a more general rule is needed ???
7785 then
7789 -- An implicit dereference freezes the designated type. In the case
7790 -- of a dispatching call whose controlling argument is an access
7791 -- type, the dereference is not made explicit, so we must check for
7792 -- such a call and freeze the designated type.
7799 then
7803 -- No point in posting several errors on the same expression
7807 else
7814 -- Local variables
7820 -- Start of processing for Freeze_Expr_Types
7822 begin
7823 -- Preanalyze a duplicate of the expression to have available the
7824 -- minimum decoration needed to locate referenced unfrozen types
7825 -- without adding any decoration to the function expression.
7831 End_Scope;
7833 -- Restore certain attributes of Def_Id since the preanalysis may
7834 -- have introduced itypes to this scope, thus modifying attributes
7835 -- First_Entity and Last_Entity.
7844 -- Freeze all types referenced in the expression
7849 -----------------------------
7850 -- Freeze_Fixed_Point_Type --
7851 -----------------------------
7853 -- Certain fixed-point types and subtypes, including implicit base types
7854 -- and declared first subtypes, have not yet set up a range. This is
7855 -- because the range cannot be set until the Small and Size values are
7856 -- known, and these are not known till the type is frozen.
7858 -- To signal this case, Scalar_Range contains an unanalyzed syntactic range
7859 -- whose bounds are unanalyzed real literals. This routine will recognize
7860 -- this case, and transform this range node into a properly typed range
7861 -- with properly analyzed and resolved values.
7878 -- Save original bounds (for shaving tests)
7881 -- Actual size chosen
7884 -- Returns size of type with given bounds. Also leaves these
7885 -- bounds set as the current bounds of the Typ.
7887 -----------
7888 -- Fsize --
7889 -----------
7892 begin
7898 -- Start of processing for Freeze_Fixed_Point_Type
7900 begin
7901 -- The type, or its first subtype if we are freezing the anonymous
7902 -- base, may have a delayed Small aspect. It must be analyzed now,
7903 -- so that all characteristics of the type (size, bounds) can be
7904 -- computed and validated in the call to Minimum_Size that follows.
7911 -- If Esize of a subtype has not previously been set, set it now
7918 else
7923 -- Immediate return if the range is already analyzed. This means that
7924 -- the range is already set, and does not need to be computed by this
7925 -- routine.
7931 -- Immediate return if either of the bounds raises Constraint_Error
7935 then
7945 -- Ordinary fixed-point case
7949 -- For the ordinary fixed-point case, we are allowed to fudge the
7950 -- end-points up or down by small. Generally we prefer to fudge up,
7951 -- i.e. widen the bounds for non-model numbers so that the end points
7952 -- are included. However there are cases in which this cannot be
7953 -- done, and indeed cases in which we may need to narrow the bounds.
7954 -- The following circuit makes the decision.
7956 -- Note: our terminology here is that Incl_EP means that the bounds
7957 -- are widened by Small if necessary to include the end points, and
7958 -- Excl_EP means that the bounds are narrowed by Small to exclude the
7959 -- end-points if this reduces the size.
7961 -- Note that in the Incl case, all we care about is including the
7962 -- end-points. In the Excl case, we want to narrow the bounds as
7963 -- much as permitted by the RM, to give the smallest possible size.
7980 begin
7981 -- First step. Base types are required to be symmetrical. Right
7982 -- now, the base type range is a copy of the first subtype range.
7983 -- This will be corrected before we are done, but right away we
7984 -- need to deal with the case where both bounds are non-negative.
7985 -- In this case, we set the low bound to the negative of the high
7986 -- bound, to make sure that the size is computed to include the
7987 -- required sign. Note that we do not need to worry about the
7988 -- case of both bounds negative, because the sign will be dealt
7989 -- with anyway. Furthermore we can't just go making such a bound
7990 -- symmetrical, since in a twos-complement system, there is an
7991 -- extra negative value which could not be accommodated on the
7992 -- positive side.
7997 then
8002 -- Compute the fudged bounds. If the number is a model number,
8003 -- then we do nothing to include it, but we are allowed to backoff
8004 -- to the next adjacent model number when we exclude it. If it is
8005 -- not a model number then we straddle the two values with the
8006 -- model numbers on either side.
8012 else
8016 -- The low value excluding the end point is Small greater, but
8017 -- we do not do this exclusion if the low value is positive,
8018 -- since it can't help the size and could actually hurt by
8019 -- crossing the high bound.
8024 -- If the value went from negative to zero, then we have the
8025 -- case where Loval_Incl_EP is the model number just below
8026 -- zero, so we want to stick to the negative value for the
8027 -- base type to maintain the condition that the size will
8028 -- include signed values.
8032 then
8036 else
8040 -- Similar processing for upper bound and high value
8046 else
8052 else
8056 -- One further adjustment is needed. In the case of subtypes, we
8057 -- cannot go outside the range of the base type, or we get
8058 -- peculiarities, and the base type range is already set. This
8059 -- only applies to the Incl values, since clearly the Excl values
8060 -- are already as restricted as they are allowed to be.
8067 -- Get size including and excluding end points
8072 -- No need to exclude end-points if it does not reduce size
8082 -- Now we set the actual size to be used. We want to use the
8083 -- bounds fudged up to include the end-points but only if this
8084 -- can be done without violating a specifically given size
8085 -- size clause or causing an unacceptable increase in size.
8087 -- Case of size clause given
8091 -- Use the inclusive size only if it is consistent with
8092 -- the explicitly specified size.
8099 -- If the inclusive size is too large, we try excluding
8100 -- the end-points (will be caught later if does not work).
8102 else
8108 -- Case of size clause not given
8110 else
8111 -- If we have a base type whose corresponding first subtype
8112 -- has an explicit size that is large enough to include our
8113 -- end-points, then do so. There is no point in working hard
8114 -- to get a base type whose size is smaller than the specified
8115 -- size of the first subtype.
8121 then
8126 -- If excluding the end-points makes the size smaller and
8127 -- results in a size of 8,16,32,64, then we take the smaller
8128 -- size. For the 64 case, this is compulsory. For the other
8129 -- cases, it seems reasonable. We like to include end points
8130 -- if we can, but not at the expense of moving to the next
8131 -- natural boundary of size.
8135 then
8140 -- Otherwise we can definitely include the end points
8142 else
8148 -- One pathological case: normally we never fudge a low bound
8149 -- down, since it would seem to increase the size (if it has
8150 -- any effect), but for ranges containing single value, or no
8151 -- values, the high bound can be small too large. Consider:
8153 -- type t is delta 2.0**(-14)
8154 -- range 131072.0 .. 0;
8156 -- That lower bound is *just* outside the range of 32 bits, and
8157 -- does need fudging down in this case. Note that the bounds
8158 -- will always have crossed here, since the high bound will be
8159 -- fudged down if necessary, as in the case of:
8161 -- type t is delta 2.0**(-14)
8162 -- range 131072.0 .. 131072.0;
8164 -- So we detect the situation by looking for crossed bounds,
8165 -- and if the bounds are crossed, and the low bound is greater
8166 -- than zero, we will always back it off by small, since this
8167 -- is completely harmless.
8174 -- And of course, we need to do exactly the same parallel
8175 -- fudge for flat ranges in the negative region.
8188 -- For the decimal case, none of this fudging is required, since there
8189 -- are no end-point problems in the decimal case (the end-points are
8190 -- always included).
8192 else
8196 -- At this stage, the actual size has been calculated and the proper
8197 -- required bounds are stored in the low and high bounds.
8201 Error_Msg_N
8203 Typ);
8207 -- Check size against explicit given size
8213 Error_Msg_NE
8217 else
8221 -- Increase size to next natural boundary if no size clause given
8223 else
8230 else
8238 -- If we have a base type, then expand the bounds so that they extend to
8239 -- the full width of the allocated size in bits, to avoid junk range
8240 -- checks on intermediate computations.
8247 -- Final step is to reanalyze the bounds using the proper type
8248 -- and set the Corresponding_Integer_Value fields of the literals.
8254 -- Resolve with universal fixed if the base type, and the base type if
8255 -- it is a subtype. Note we can't resolve the base type with itself,
8256 -- that would be a reference before definition.
8260 else
8264 -- Set corresponding integer value for bound
8266 Set_Corresponding_Integer_Value
8269 -- Similar processing for high bound
8277 else
8281 Set_Corresponding_Integer_Value
8284 -- Set type of range to correspond to bounds
8288 -- Set Esize to calculated size if not set already
8294 -- Set RM_Size if not already set. If already set, check value
8296 declare
8299 begin
8304 Error_Msg_NE
8309 else
8314 -- Check for shaving
8318 -- In SPARK mode the given bounds must be strictly representable
8322 Error_Msg_NE
8328 Error_Msg_NE
8333 else
8335 Error_Msg_N
8337 Error_Msg_N
8342 Error_Msg_N
8344 Typ);
8345 Error_Msg_N
8352 ------------------
8353 -- Freeze_Itype --
8354 ------------------
8359 begin
8368 --------------------------
8369 -- Freeze_Static_Object --
8370 --------------------------
8375 -- Exception raised if the type of a static object cannot be made
8376 -- static. This happens if the type depends on non-global objects.
8379 -- Called to ensure that an expression used as part of a type definition
8380 -- is statically allocatable, which means that the expression type is
8381 -- statically allocatable, and the expression is either static, or a
8382 -- reference to a library level constant.
8385 -- Called to mark a type as static, checking that it is possible
8386 -- to set the type as static. If it is not possible, then the
8387 -- exception Cannot_Be_Static is raised.
8389 -----------------------------
8390 -- Ensure_Expression_Is_SA --
8391 -----------------------------
8396 begin
8408 then
8416 -----------------------
8417 -- Ensure_Type_Is_SA --
8418 -----------------------
8424 begin
8425 -- If type is library level, we are all set
8431 -- We are also OK if the type already marked as statically allocated,
8432 -- which means we processed it before.
8438 -- Mark type as statically allocated
8442 -- Check that it is safe to statically allocate this type
8460 declare
8464 begin
8476 else
8485 then
8504 else
8509 -- Start of processing for Freeze_Static_Object
8511 begin
8514 exception
8517 -- If the object that cannot be static is imported or exported, then
8518 -- issue an error message saying that this object cannot be imported
8519 -- or exported. If it has an address clause it is an overlay in the
8520 -- current partition and the static requirement is not relevant.
8521 -- Do not issue any error message when ignoring rep clauses.
8528 Error_Msg_N
8532 -- Otherwise must be exported, something is wrong if compiler
8533 -- is marking something as statically allocated which cannot be).
8536 Error_Msg_N
8541 -----------------------
8542 -- Freeze_Subprogram --
8543 -----------------------
8547 -- Set the conventions of all anonymous access-to-subprogram formals and
8548 -- result subtype of subprogram Subp_Id to the convention of Subp_Id.
8550 ----------------------------
8551 -- Set_Profile_Convention --
8552 ----------------------------
8558 -- Set the convention of anonymous access-to-subprogram type Typ and
8559 -- its designated type to Conv.
8561 -------------------------
8562 -- Set_Type_Convention --
8563 -------------------------
8566 begin
8567 -- Set the convention on both the anonymous access-to-subprogram
8568 -- type and the subprogram type it points to because both types
8569 -- participate in conformance-related checks.
8577 -- Local variables
8581 -- Start of processing for Set_Profile_Convention
8583 begin
8595 -- Local variables
8600 -- Start of processing for Freeze_Subprogram
8602 begin
8603 -- Subprogram may not have an address clause unless it is imported
8607 Error_Msg_N
8613 -- Reset the Pure indication on an imported subprogram unless an
8614 -- explicit Pure_Function pragma was present or the subprogram is an
8615 -- intrinsic. We do this because otherwise it is an insidious error
8616 -- to call a non-pure function from pure unit and have calls
8617 -- mysteriously optimized away. What happens here is that the Import
8618 -- can bypass the normal check to ensure that pure units call only pure
8619 -- subprograms.
8621 -- The reason for the intrinsic exception is that in general, intrinsic
8622 -- functions (such as shifts) are pure anyway. The only exceptions are
8623 -- the intrinsics in GNAT.Source_Info, and that unit is not marked Pure
8624 -- in any case, so no problem arises.
8630 then
8634 -- We also reset the Pure indication on a subprogram with an Address
8635 -- parameter, because the parameter may be used as a pointer and the
8636 -- referenced data may change even if the address value does not.
8638 -- Note that if the programmer gave an explicit Pure_Function pragma,
8639 -- then we believe the programmer, and leave the subprogram Pure. We
8640 -- also suppress this check on run-time files.
8646 then
8650 -- Ensure that all anonymous access-to-subprogram types inherit the
8651 -- convention of their related subprogram (RM 6.3.1 13.1/3). This is
8652 -- not done for a defaulted convention Ada because those types also
8653 -- default to Ada. Convention Protected must not be propagated when
8654 -- the subprogram is an entry because this would be illegal. The only
8655 -- way to force convention Protected on these kinds of types is to
8656 -- include keyword "protected" in the access definition.
8660 then
8664 -- For non-foreign convention subprograms, this is where we create
8665 -- the extra formals (for accessibility level and constrained bit
8666 -- information). We delay this till the freeze point precisely so
8667 -- that we know the convention.
8676 -- If this is convention Ada and a Valued_Procedure, that's odd
8681 and then Warn_On_Export_Import
8682 then
8683 Error_Msg_N
8688 -- Case of foreign convention
8690 else
8693 -- For foreign conventions, warn about return of unconstrained array
8698 -- If no return type, probably some other error, e.g. a
8699 -- missing full declaration, so ignore.
8704 -- If the return type is generic, we have emitted a warning
8705 -- earlier on, and there is nothing else to check here. Specific
8706 -- instantiations may lead to erroneous behavior.
8711 -- Display warning if returning unconstrained array
8716 -- Check appropriate warning is enabled (should we check for
8717 -- Warnings (Off) on specific entities here, probably so???)
8719 and then Warn_On_Export_Import
8720 then
8721 Error_Msg_N
8728 -- If any of the formals for an exported foreign convention
8729 -- subprogram have defaults, then emit an appropriate warning since
8730 -- this is odd (default cannot be used from non-Ada code)
8735 if Warn_On_Export_Import
8737 then
8738 Error_Msg_N
8748 -- Pragma Inline_Always is disallowed for dispatching subprograms
8749 -- because the address of such subprograms is saved in the dispatch
8750 -- table to support dispatching calls, and dispatching calls cannot
8751 -- be inlined. This is consistent with the restriction against using
8752 -- 'Access or 'Address on an Inline_Always subprogram.
8756 then
8757 Error_Msg_N
8761 -- Because of the implicit representation of inherited predefined
8762 -- operators in the front-end, the overriding status of the operation
8763 -- may be affected when a full view of a type is analyzed, and this is
8764 -- not captured by the analysis of the corresponding type declaration.
8765 -- Therefore the correctness of a not-overriding indicator must be
8766 -- rechecked when the subprogram is frozen.
8770 then
8774 if Modify_Tree_For_C
8780 then
8785 ----------------------
8786 -- Is_Fully_Defined --
8787 ----------------------
8790 begin
8799 then
8800 -- Verify that the record type has no components with private types
8801 -- without completion.
8803 declare
8806 begin
8818 -- For the designated type of an access to subprogram, all types in
8819 -- the profile must be fully defined.
8822 declare
8825 begin
8838 else
8844 ---------------------------------
8845 -- Process_Default_Expressions --
8846 ---------------------------------
8848 procedure Process_Default_Expressions
8851 is
8858 begin
8861 -- A subprogram instance and its associated anonymous subprogram share
8862 -- their signature. The default expression functions are defined in the
8863 -- wrapper packages for the anonymous subprogram, and should not be
8864 -- generated again for the instance.
8869 then
8877 -- We work with a copy of the default expression because we
8878 -- do not want to disturb the original, since this would mess
8879 -- up the conformance checking.
8883 -- The analysis of the expression may generate insert actions,
8884 -- which of course must not be executed. We wrap those actions
8885 -- in a procedure that is not called, and later on eliminated.
8886 -- The following cases have no side effects, and are analyzed
8887 -- directly.
8891 N_Integer_Literal,
8892 N_Character_Literal,
8893 N_String_Literal,
8894 N_Real_Literal)
8898 then
8899 -- If there is no default function, we must still do a full
8900 -- analyze call on the default value, to ensure that all error
8901 -- checks are performed, e.g. those associated with static
8902 -- evaluation. Note: this branch will always be taken if the
8903 -- analyzer is turned off (but we still need the error checks).
8905 -- Note: the setting of parent here is to meet the requirement
8906 -- that we can only analyze the expression while attached to
8907 -- the tree. Really the requirement is that the parent chain
8908 -- be set, we don't actually need to be in the tree.
8913 -- Default expressions are resolved with their own type if the
8914 -- context is generic, to avoid anomalies with private types.
8918 else
8922 -- If that resolved expression will raise constraint error,
8923 -- then flag the default value as raising constraint error.
8924 -- This allows a proper error message on the calls.
8930 -- If the default is a parameterless call, we use the name of
8931 -- the called function directly, and there is no body to build.
8935 then
8938 -- Else construct and analyze the body of a wrapper procedure
8939 -- that contains an object declaration to hold the expression.
8940 -- Given that this is done only to complete the analysis, it is
8941 -- simpler to build a procedure than a function which might
8942 -- involve secondary stack expansion.
8944 else
8947 Dbody :=
8949 Specification =>
8956 Object_Definition =>
8960 Handled_Statement_Sequence =>
8977 ----------------------------------------
8978 -- Set_Component_Alignment_If_Not_Set --
8979 ----------------------------------------
8982 begin
8983 -- Ignore if not base type, subtypes don't need anything
8989 -- Do not override existing representation
9000 else
9001 Set_Component_Alignment
9007 --------------------------
9008 -- Set_SSO_From_Default --
9009 --------------------------
9014 begin
9015 -- Set default SSO for an array or record base type, except in case of
9016 -- a type extension (which always inherits the SSO of its parent type).
9023 then
9024 Reversed :=
9026 or else
9031 -- For a record type, if bit order is specified explicitly,
9032 -- then do not set SSO from default if not consistent. Note that
9033 -- we do not want to look at a Bit_Order attribute definition
9034 -- for a parent: if we were to inherit Bit_Order, then both
9035 -- SSO_Set_*_By_Default flags would have been cleared already
9036 -- (by Inherit_Aspects_At_Freeze_Point).
9038 and then not
9040 and then
9043 then
9044 -- If flags cause reverse storage order, then set the result. Note
9045 -- that we would have ignored the pragma setting the non default
9046 -- storage order in any case, hence the assertion at this point.
9048 pragma Assert
9053 -- For a record type, also set reversed bit order. Note: if a bit
9054 -- order has been specified explicitly, then this is a no-op.
9063 ------------------
9064 -- Undelay_Type --
9065 ------------------
9068 begin
9072 -- Since we don't want T to have a Freeze_Node, we don't want its
9073 -- Full_View or Corresponding_Record_Type to have one either.
9075 -- ??? Fundamentally, this whole handling is unpleasant. What we really
9076 -- want is to be sure that for an Itype that's part of record R and is a
9077 -- subtype of type T, that it's frozen after the later of the freeze
9078 -- points of R and T. We have no way of doing that directly, so what we
9079 -- do is force most such Itypes to be frozen as part of freezing R via
9080 -- this procedure and only delay the ones that need to be delayed
9081 -- (mostly the designated types of access types that are defined as part
9082 -- of the record).
9088 then
9096 then
9101 ------------------
9102 -- Warn_Overlay --
9103 ------------------
9107 -- The object to which the address clause applies
9113 begin
9114 -- No warning if address clause overlay warnings are off
9120 -- No warning if there is an explicit initialization
9128 -- We only give the warning for non-imported entities of a type for
9129 -- which a non-null base init proc is defined, or for objects of access
9130 -- types with implicit null initialization, or when Normalize_Scalars
9131 -- applies and the type is scalar or a string type (the latter being
9132 -- tested for because predefined String types are initialized by inline
9133 -- code rather than by an init_proc). Note that we do not give the
9134 -- warning for Initialize_Scalars, since we suppressed initialization
9135 -- in this case. Also, do not warn if Suppress_Initialization is set
9136 -- either on the type, or on the object via pragma or aspect.
9148 then
9151 then
9156 then
9163 then
9170 -- A function call (most likely to To_Address) is probably not an
9171 -- overlay, so skip warning. Ditto if the function call was inlined
9172 -- and transformed into an entity.
9178 -- If a pragma Import follows, we assume that it is for the current
9179 -- target of the address clause, and skip the warning. There may be
9180 -- a source pragma or an aspect that specifies import and generates
9181 -- the corresponding pragma. These will indicate that the entity is
9182 -- imported and that is checked above so that the spurious warning
9183 -- (generated when the entity is frozen) will be suppressed. The
9184 -- pragma may be attached to the aspect, so it is not yet a list
9185 -- member.
9193 then
9198 -- Otherwise give warning message
9202 Error_Msg_N
9204 Nam);
9205 else
9206 Error_Msg_N
9208 Nam);
9211 -- Add friendly warning if initialization comes from a packed array
9212 -- component.
9215 declare
9218 begin
9223 then
9227 then
9228 Error_Msg_NE
9233 else
9240 Error_Msg_N
9243 Nam);