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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 ------------------------------------------------------------------------------
73 -----------------------
74 -- Local Subprograms --
75 -----------------------
78 -- Typ is a type that is being frozen. If no size clause is given,
79 -- but a default Esize has been computed, then this default Esize is
80 -- adjusted up if necessary to be consistent with a given alignment,
81 -- but never to a value greater than Long_Long_Integer'Size. This
82 -- is used for all discrete types and for fixed-point types.
84 procedure Build_And_Analyze_Renamed_Body
88 -- Build body for a renaming declaration, insert in tree and analyze
91 -- Apply legality checks to address clauses for object declarations,
92 -- at the point the object is frozen. Also ensure any initialization is
93 -- performed only after the object has been frozen.
95 procedure Check_Component_Storage_Order
100 -- For an Encl_Type that has a Scalar_Storage_Order attribute definition
101 -- clause, verify that the component type has an explicit and compatible
102 -- attribute/aspect. For arrays, Comp is Empty; for records, it is the
103 -- entity of the component under consideration. For an Encl_Type that
104 -- does not have a Scalar_Storage_Order attribute definition clause,
105 -- verify that the component also does not have such a clause.
106 -- ADC is the attribute definition clause if present (or Empty). On return,
107 -- Comp_ADC_Present is set True if the component has a Scalar_Storage_Order
108 -- attribute definition clause.
111 -- As each entity is frozen, this routine is called to deal with the
112 -- setting of Debug_Info_Needed for the entity. This flag is set if
113 -- the entity comes from source, or if we are in Debug_Generated_Code
114 -- mode or if the -gnatdV debug flag is set. However, it never sets
115 -- the flag if Debug_Info_Off is set. This procedure also ensures that
116 -- subsidiary entities have the flag set as required.
119 -- When an expression function is frozen by a use of it, the expression
120 -- itself is frozen. Check that the expression does not include references
121 -- to deferred constants without completion. We report this at the freeze
122 -- point of the function, to provide a better error message.
123 --
124 -- In most cases the expression itself is frozen by the time the function
125 -- itself is frozen, because the formals will be frozen by then. However,
126 -- Attribute references to outer types are freeze points for those types;
127 -- this routine generates the required freeze nodes for them.
130 -- For a tagged derived type, create wrappers for inherited operations
131 -- that have a class-wide condition, so it can be properly rewritten if
132 -- it involves calls to other overriding primitives.
135 -- E is a base type. If E is tagged or has a component that is aliased
136 -- or tagged or contains something this is aliased or tagged, set
137 -- Strict_Alignment.
141 -- If E is a fixed-point or discrete type, then all the necessary work
142 -- to freeze it is completed except for possible setting of the flag
143 -- Is_Unsigned_Type, which is done by this procedure. The call has no
144 -- effect if the entity E is not a discrete or fixed-point type.
146 procedure Freeze_And_Append
150 -- Freezes Ent using Freeze_Entity, and appends the resulting list of
151 -- nodes to Result, modifying Result from No_List if necessary. N has
152 -- the same usage as in Freeze_Entity.
155 -- Freeze enumeration type. The Esize field is set as processing
156 -- proceeds (i.e. set by default when the type is declared and then
157 -- adjusted by rep clauses. What this procedure does is to make sure
158 -- that if a foreign convention is specified, and no specific size
159 -- is given, then the size must be at least Integer'Size.
162 -- If an object is frozen which has Is_Statically_Allocated set, then
163 -- all referenced types must also be marked with this flag. This routine
164 -- is in charge of meeting this requirement for the object entity E.
167 -- Perform freezing actions for a subprogram (create extra formals,
168 -- and set proper default mechanism values). Note that this routine
169 -- is not called for internal subprograms, for which neither of these
170 -- actions is needed (or desirable, we do not want for example to have
171 -- these extra formals present in initialization procedures, where they
172 -- would serve no purpose). In this call E is either a subprogram or
173 -- a subprogram type (i.e. an access to a subprogram).
176 -- True if T is not private and has no private components, or has a full
177 -- view. Used to determine whether the designated type of an access type
178 -- should be frozen when the access type is frozen. This is done when an
179 -- allocator is frozen, or an expression that may involve attributes of
180 -- the designated type. Otherwise freezing the access type does not freeze
181 -- the designated type.
183 procedure Process_Default_Expressions
186 -- This procedure is called for each subprogram to complete processing of
187 -- default expressions at the point where all types are known to be frozen.
188 -- The expressions must be analyzed in full, to make sure that all error
189 -- processing is done (they have only been pre-analyzed). If the expression
190 -- is not an entity or literal, its analysis may generate code which must
191 -- not be executed. In that case we build a function body to hold that
192 -- code. This wrapper function serves no other purpose (it used to be
193 -- called to evaluate the default, but now the default is inlined at each
194 -- point of call).
197 -- Typ is a record or array type that is being frozen. This routine sets
198 -- the default component alignment from the scope stack values if the
199 -- alignment is otherwise not specified.
202 -- T is a record or array type that is being frozen. If it is a base type,
203 -- and if SSO_Set_Low/High_By_Default is set, then Reverse_Storage order
204 -- will be set appropriately. Note that an explicit occurrence of aspect
205 -- Scalar_Storage_Order or an explicit setting of this aspect with an
206 -- attribute definition clause occurs, then these two flags are reset in
207 -- any case, so call will have no effect.
210 -- T is a type of a component that we know to be an Itype. We don't want
211 -- this to have a Freeze_Node, so ensure it doesn't. Do the same for any
212 -- Full_View or Corresponding_Record_Type.
215 -- Expr is the expression for an address clause for entity Nam whose type
216 -- is Typ. If Typ has a default initialization, and there is no explicit
217 -- initialization in the source declaration, check whether the address
218 -- clause might cause overlaying of an entity, and emit a warning on the
219 -- side effect that the initialization will cause.
221 -------------------------------
222 -- Adjust_Esize_For_Alignment --
223 -------------------------------
228 begin
234 then
240 ------------------------------------
241 -- Build_And_Analyze_Renamed_Body --
242 ------------------------------------
244 procedure Build_And_Analyze_Renamed_Body
248 is
254 begin
255 -- If the renamed subprogram is intrinsic, there is no need for a
256 -- wrapper body: we set the alias that will be called and expanded which
257 -- completes the declaration. This transformation is only legal if the
258 -- renamed entity has already been elaborated.
260 -- Note that it is legal for a renaming_as_body to rename an intrinsic
261 -- subprogram, as long as the renaming occurs before the new entity
262 -- is frozen (RM 8.5.4 (5)).
266 then
268 else
274 and then
278 -- We can make the renaming entity intrinsic if the renamed function
279 -- has an interface name, or if it is one of the shift/rotate
280 -- operations known to the compiler.
282 and then
285 Name_Rotate_Right,
286 Name_Shift_Left,
287 Name_Shift_Right,
288 Name_Shift_Right_Arithmetic))
289 then
294 else
301 else
310 ------------------------
311 -- Build_Renamed_Body --
312 ------------------------
314 function Build_Renamed_Body
317 is
319 -- We use for the source location of the renamed body, the location of
320 -- the spec entity. It might seem more natural to use the location of
321 -- the renaming declaration itself, but that would be wrong, since then
322 -- the body we create would look as though it was created far too late,
323 -- and this could cause problems with elaboration order analysis,
324 -- particularly in connection with instantiations.
339 -- If the renamed entity is a primitive operation given in prefix form,
340 -- the prefix is the target object and it has to be added as the first
341 -- actual in the generated call.
343 begin
344 -- Determine the entity being renamed, which is the target of the call
345 -- statement. If the name is an explicit dereference, this is a renaming
346 -- of a subprogram type rather than a subprogram. The name itself is
347 -- fully analyzed.
358 else
365 else
371 -- If the renamed entity is a predefined operator, retain full name
372 -- to ensure its visibility.
376 then
378 else
382 else
385 and then
388 then
390 -- Retrieve the target object, to be added as a first actual
391 -- in the call.
396 else
400 -- Original name may have been overloaded, but is fully resolved now
405 -- For simple renamings, subsequent calls can be expanded directly as
406 -- calls to the renamed entity. The body must be generated in any case
407 -- for calls that may appear elsewhere. This is not done in the case
408 -- where the subprogram is an instantiation because the actual proper
409 -- body has not been built yet.
414 then
418 -- Check whether the return type is a limited view. If the subprogram
419 -- is already frozen the generated body may have a non-limited view
420 -- of the type, that must be used, because it is the one in the spec
421 -- of the renaming declaration.
425 then
426 declare
428 begin
430 Set_Result_Definition
436 -- The body generated for this renaming is an internal artifact, and
437 -- does not constitute a freeze point for the called entity.
444 declare
448 begin
449 -- The controlling formal may be an access parameter, or the
450 -- actual may be an access value, so adjust accordingly.
454 then
455 Actuals := New_List
460 then
461 Actuals :=
462 New_List (
466 else
474 else
485 -- If the renamed entity is an entry, inherit its profile. For other
486 -- renamings as bodies, both profiles must be subtype conformant, so it
487 -- is not necessary to replace the profile given in the declaration.
488 -- However, default values that are aggregates are rewritten when
489 -- partially analyzed, so we recover the original aggregate to insure
490 -- that subsequent conformity checking works. Similarly, if the default
491 -- expression was constant-folded, recover the original expression.
501 N_Access_Definition
502 then
510 then
521 -- If the renamed entity is a function, the generated body contains a
522 -- return statement. Otherwise, build a procedure call. If the entity is
523 -- an entry, subsequent analysis of the call will transform it into the
524 -- proper entry or protected operation call. If the renamed entity is
525 -- a character literal, return it directly.
531 then
532 Call_Node :=
534 Expression =>
540 Call_Node :=
545 Call_Node :=
548 else
549 Call_Node :=
555 -- Create entities for subprogram body and formals
568 Body_Node :=
572 Handled_Statement_Sequence =>
582 -- Link the body to the entity whose declaration it completes. If
583 -- the body is analyzed when the renamed entity is frozen, it may
584 -- be necessary to restore the proper scope (see package Exp_Ch13).
588 then
590 else
597 --------------------------
598 -- Check_Address_Clause --
599 --------------------------
610 begin
613 -- For a deferred constant, the initialization value is on full view
617 else
626 -- Has_Delayed_Freeze was set on E when the address clause was
627 -- analyzed, and must remain set because we want the address
628 -- clause to be elaborated only after any entity it references
629 -- has been elaborated.
632 -- If Rep_Clauses are to be ignored, remove address clause from
633 -- list attached to entity, because it may be illegal for gigi,
634 -- for example by breaking order of elaboration..
637 declare
640 begin
646 else
649 loop
659 -- And now remove the address clause
665 then
671 -- If a variable, or a non-imported constant, overlays a constant
672 -- object and has an initialization value, then the initialization
673 -- may end up writing into read-only memory. Detect the cases of
674 -- statically identical values and remove the initialization. In
675 -- the other cases, give a warning. We will give other warnings
676 -- later for the variable if it is assigned.
683 then
684 declare
688 begin
694 and then Compile_Time_Compare
698 then
703 and then Address_Clause_Overlay_Warnings
704 then
706 Error_Msg_NE
713 -- Remove side effects from initial expression, except in the case
714 -- of a build-in-place call, which has its own later expansion.
719 then
720 -- Capture initialization value at point of declaration, and make
721 -- explicit assignment legal, because object may be a constant.
727 -- Move initialization to freeze actions, once the object has
728 -- been frozen and the address clause alignment check has been
729 -- performed.
738 -- If the objet is tagged, check whether the tag must be
739 -- reassigned explicitly.
749 -----------------------------
750 -- Check_Compile_Time_Size --
751 -----------------------------
756 -- Sets the compile time known size (64 bits or less) in the RM_Size
757 -- field of T, checking for a size clause that was given which attempts
758 -- to give a smaller size.
761 -- Recursive function that does all the work
764 -- If T is a constrained subtype, its size is not known if any of its
765 -- discriminant constraints is not static and it is not a null record.
766 -- The test is conservative and doesn't check that the components are
767 -- in fact constrained by non-static discriminant values. Could be made
768 -- more precise ???
770 --------------------
771 -- Set_Small_Size --
772 --------------------
775 begin
779 -- Check for bad size clause given
784 Error_Msg_NE
789 -- Set size if not set already
796 ----------------
797 -- Size_Known --
798 ----------------
807 begin
811 -- Always True for elementary types, even generic formal elementary
812 -- types. We used to return False in the latter case, but the size
813 -- is known at compile time, even in the template, we just do not
814 -- know the exact size but that's not the point of this routine.
819 -- Array types
823 -- String literals always have known size, and we can set it
826 Set_Small_Size
830 -- Unconstrained types never have known at compile time size
835 -- Don't do any recursion on type with error posted, since we may
836 -- have a malformed type that leads us into a loop.
841 -- Otherwise if component size unknown, then array size unknown
847 -- Check for all indexes static, and also compute possible size
848 -- (in case it is not greater than 64 and may be packable).
850 declare
854 begin
863 else
871 then
874 else
879 else
891 -- For non-generic private types, go to underlying type if present
896 then
897 -- Don't do any recursion on type with error posted, since we may
898 -- have a malformed type that leads us into a loop.
902 else
906 -- Record types
910 -- A class-wide type is never considered to have a known size
915 -- A subtype of a variant record must not have non-static
916 -- discriminated components.
920 then
923 -- Don't do any recursion on type with error posted, since we may
924 -- have a malformed type that leads us into a loop.
930 -- Now look at the components of the record
932 declare
933 -- The following two variables are used to keep track of the
934 -- size of packed records if we can tell the size of the packed
935 -- record in the front end. Packed_Size_Known is True if so far
936 -- we can figure out the size. It is initialized to True for a
937 -- packed record, unless the record has discriminants or atomic
938 -- components or independent components.
940 -- The reason we eliminate the discriminated case is that
941 -- we don't know the way the back end lays out discriminated
942 -- packed records. If Packed_Size_Known is True, then
943 -- Packed_Size is the size in bits so far.
952 -- Size in bits so far
954 begin
955 -- Test for variant part present
961 N_Record_Definition
963 and then
964 Present (Variant_Part
966 then
967 -- If variant part is present, and type is unconstrained,
968 -- then we must have defaulted discriminants, or a size
969 -- clause must be present for the type, or else the size
970 -- is definitely not known at compile time.
973 and then
976 then
981 -- Loop through components
987 -- We do not know the packed size if there is a component
988 -- clause present (we possibly could, but this would only
989 -- help in the case of a record with partial rep clauses.
990 -- That's because in the case of full rep clauses, the
991 -- size gets figured out anyway by a different circuit).
997 -- We do not know the packed size for an atomic/VFA type
998 -- or component, or an independent type or component, or a
999 -- by-reference type or aliased component (because packing
1000 -- does not touch these).
1008 then
1012 -- We need to identify a component that is an array where
1013 -- the index type is an enumeration type with non-standard
1014 -- representation, and some bound of the type depends on a
1015 -- discriminant.
1017 -- This is because gigi computes the size by doing a
1018 -- substitution of the appropriate discriminant value in
1019 -- the size expression for the base type, and gigi is not
1020 -- clever enough to evaluate the resulting expression (which
1021 -- involves a call to rep_to_pos) at compile time.
1023 -- It would be nice if gigi would either recognize that
1024 -- this expression can be computed at compile time, or
1025 -- alternatively figured out the size from the subtype
1026 -- directly, where all the information is at hand ???
1030 then
1031 declare
1039 begin
1046 then
1052 then
1057 then
1067 -- Clearly size of record is not known if the size of one of
1068 -- the components is not known.
1074 -- Accumulate packed size if possible
1078 -- We can deal with elementary types, small packed arrays
1079 -- if the representation is a modular type and also small
1080 -- record types (if the size is not greater than 64, but
1081 -- the condition is checked by Set_Small_Size).
1085 and then Present
1087 and then Is_Modular_Integer_Type
1090 then
1091 -- If RM_Size is known and static, then we can keep
1092 -- accumulating the packed size.
1098 -- If we have a field whose RM_Size is not known then
1099 -- we can't figure out the packed size here.
1101 else
1105 -- For other types we can't figure out the packed size
1107 else
1122 -- All other cases, size not known at compile time
1124 else
1129 -------------------------------------
1130 -- Static_Discriminated_Components --
1131 -------------------------------------
1133 function Static_Discriminated_Components
1135 is
1138 begin
1142 then
1156 -- Start of processing for Check_Compile_Time_Size
1158 begin
1162 -----------------------------------
1163 -- Check_Component_Storage_Order --
1164 -----------------------------------
1166 procedure Check_Component_Storage_Order
1171 is
1180 -- Set for the record case, True if Comp is aligned on byte boundaries
1181 -- (in which case it is allowed to have different storage order).
1184 -- Set True when the component is a nested composite, and it does not
1185 -- have the same scalar storage order as Encl_Type.
1187 begin
1188 -- Record case
1198 else
1199 -- If a component clause is present, check if the component starts
1200 -- and ends on byte boundaries. Otherwise conservatively assume it
1201 -- does so only in the case where the record is not packed.
1204 Comp_Byte_Aligned :=
1206 and then
1208 else
1215 -- Array case
1217 else
1224 -- Note: the Reverse_Storage_Order flag is set on the base type, but
1225 -- the attribute definition clause is attached to the first subtype.
1226 -- Also, if the base type is incomplete or private, go to full view
1227 -- if known
1239 Comp_ADC :=
1240 Get_Attribute_Definition_Clause
1244 -- Case of record or array component: check storage order compatibility.
1245 -- But, if the record has Complex_Representation, then it is treated as
1246 -- a scalar in the back end so the storage order is irrelevant.
1251 then
1252 Comp_SSO_Differs :=
1256 -- Parent and extension must have same storage order
1260 Error_Msg_N
1265 -- If component and composite SSO differs, check that component
1266 -- falls on byte boundaries and isn't bit packed.
1270 -- Component SSO differs from enclosing composite:
1272 -- Reject if composite is a bit-packed array, as it is rewritten
1273 -- into an array of scalars.
1276 Error_Msg_N
1280 -- Reject if not byte aligned
1283 and then not Comp_Byte_Aligned
1284 then
1285 Error_Msg_N
1289 -- Warn if specified only for the outer composite
1292 Error_Msg_NE
1298 -- Enclosing type has explicit SSO: non-composite component must not
1299 -- be aliased.
1302 Error_Msg_N
1308 -----------------------------
1309 -- Check_Debug_Info_Needed --
1310 -----------------------------
1313 begin
1318 or else Debug_Generated_Code
1319 or else Debug_Flag_VV
1321 then
1326 -------------------------------
1327 -- Check_Expression_Function --
1328 -------------------------------
1332 -- Function to search for deferred constant
1334 -------------------
1335 -- Find_Constant --
1336 -------------------
1339 begin
1340 -- When a constant is initialized with the result of a dispatching
1341 -- call, the constant declaration is rewritten as a renaming of the
1342 -- displaced function result. This scenario is not a premature use of
1343 -- a constant even though the Has_Completion flag is not set.
1350 N_Object_Declaration
1354 then
1355 Error_Msg_NE
1363 then
1373 -- Local variables
1377 -- Start of processing for Check_Expression_Function
1379 begin
1382 -- The subprogram body created for the expression function is not
1383 -- itself a freeze point.
1388 then
1393 --------------------------------
1394 -- Check_Inherited_Conditions --
1395 --------------------------------
1406 -- Build corresponding pragmas for an operation whose ancestor has
1407 -- class-wide pre/postconditions. If the operation is inherited, the
1408 -- pragmas force the creation of a wrapper for the inherited operation.
1409 -- If the ancestor is being overridden, the pragmas are constructed only
1410 -- to verify their legality, in case they contain calls to other
1411 -- primitives that may haven been overridden.
1413 ---------------------------------------
1414 -- Build_Inherited_Condition_Pragmas --
1415 ---------------------------------------
1422 begin
1427 Build_Class_Wide_Expression
1434 if Needs_Wrapper
1436 and then Expander_Active
1437 then
1446 Build_Class_Wide_Expression
1453 if Needs_Wrapper
1455 and then Expander_Active
1456 then
1462 -- Start of processing for Check_Inherited_Conditions
1464 begin
1469 -- Map the overridden primitive to the overriding one. This takes
1470 -- care of all overridings and is done only once.
1474 then
1482 -- Perform validity checks on the inherited conditions of overriding
1483 -- operations, for conformance with LSP, and apply SPARK-specific
1484 -- restrictions on inherited conditions.
1492 then
1495 -- Analyze the contract items of the overridden operation, before
1496 -- they are rewritten as pragmas.
1500 -- In GNATprove mode this is where we can collect the inherited
1501 -- conditions, because we do not create the Check pragmas that
1502 -- normally convey the the modified class-wide conditions on
1503 -- overriding operations.
1508 -- Otherwise build the corresponding pragmas to check for legality
1509 -- of the inherited condition.
1511 else
1519 -- Now examine the inherited operations to check whether they require
1520 -- a wrapper to handle inherited conditions that call other primitives,
1521 -- so that LSP can be verified/enforced.
1533 -- Analyze the contract items of the parent operation, and
1534 -- determine whether a wrapper is needed. This is determined
1535 -- when the condition is rewritten in sem_prag, using the
1536 -- mapping between overridden and overriding operations built
1537 -- in the loop above.
1543 if Needs_Wrapper
1545 and then Expander_Active
1546 then
1547 -- We need to build a new primitive that overrides the inherited
1548 -- one, and whose inherited expression has been updated above.
1549 -- These expressions are the arguments of pragmas that are part
1550 -- of the declarations of the wrapper. The wrapper holds a single
1551 -- statement that is a call to the class-wide clone, where the
1552 -- controlling actuals are conversions to the corresponding type
1553 -- in the parent primitive:
1555 -- procedure New_Prim (F1 : T1; ...);
1556 -- procedure New_Prim (F1 : T1; ...) is
1557 -- pragma Check (Precondition, Expr);
1558 -- begin
1559 -- Par_Prim_Clone (Par_Type (F1), ...);
1560 -- end;
1562 -- If the primitive is a function the statement is a return
1563 -- statement with a call.
1565 declare
1572 begin
1574 New_Decl :=
1578 -- Insert the declaration and the body of the wrapper after
1579 -- type declaration that generates inherited operation. For
1580 -- a null procedure, the declaration implies a null body.
1584 then
1587 else
1588 -- Build body as wrapper to a call to the already built
1589 -- class-wide clone.
1591 New_Body :=
1592 Build_Class_Wide_Clone_Call
1595 Insert_List_After_And_Analyze
1607 ----------------------------
1608 -- Check_Strict_Alignment --
1609 ----------------------------
1614 begin
1632 then
1642 -------------------------
1643 -- Check_Unsigned_Type --
1644 -------------------------
1651 begin
1656 -- Do not attempt to analyze case where range was in error
1662 -- The situation that is nontrivial is something like:
1664 -- subtype x1 is integer range -10 .. +10;
1665 -- subtype x2 is x1 range 0 .. V1;
1666 -- subtype x3 is x2 range V2 .. V3;
1667 -- subtype x4 is x3 range V4 .. V5;
1669 -- where Vn are variables. Here the base type is signed, but we still
1670 -- know that x4 is unsigned because of the lower bound of x2.
1672 -- The only way to deal with this is to look up the ancestor chain
1675 loop
1689 else
1692 -- If no ancestor had a static lower bound, go to base type
1696 -- Note: the reason we still check for a compile time known
1697 -- value for the base type is that at least in the case of
1698 -- generic formals, we can have bounds that fail this test,
1699 -- and there may be other cases in error situations.
1711 then
1721 -----------------------------
1722 -- Is_Atomic_VFA_Aggregate --
1723 -----------------------------
1732 begin
1735 -- Array may be qualified, so find outer context
1752 then
1761 then
1770 New_N :=
1782 -----------------------------------------------
1783 -- Explode_Initialization_Compound_Statement --
1784 -----------------------------------------------
1789 begin
1792 then
1795 -- Note that we rewrite Init_Stmts into a NULL statement, rather than
1796 -- just removing it, because Freeze_All may rely on this particular
1797 -- Node_Id still being present in the enclosing list to know where to
1798 -- stop freezing.
1806 ----------------
1807 -- Freeze_All --
1808 ----------------
1810 -- Note: the easy coding for this procedure would be to just build a
1811 -- single list of freeze nodes and then insert them and analyze them
1812 -- all at once. This won't work, because the analysis of earlier freeze
1813 -- nodes may recursively freeze types which would otherwise appear later
1814 -- on in the freeze list. So we must analyze and expand the freeze nodes
1815 -- as they are generated.
1819 -- This is the internal recursive routine that does freezing of entities
1820 -- (but NOT the analysis of default expressions, which should not be
1821 -- recursive, we don't want to analyze those till we are sure that ALL
1822 -- the types are frozen).
1824 --------------------
1825 -- Freeze_All_Ent --
1826 --------------------
1834 -- If freeze nodes are present, insert and analyze, and reset cursor
1835 -- for next insertion.
1837 -------------------
1838 -- Process_Flist --
1839 -------------------
1842 begin
1849 else
1855 -- Start of processing for Freeze_All_Ent
1857 begin
1861 -- If the entity is an inner package which is not a package
1862 -- renaming, then its entities must be frozen at this point. Note
1863 -- that such entities do NOT get frozen at the end of the nested
1864 -- package itself (only library packages freeze).
1866 -- Same is true for task declarations, where anonymous records
1867 -- created for entry parameters must be frozen.
1873 then
1884 then
1891 N_Task_Type_Declaration)
1892 then
1895 End_Scope;
1897 -- For a derived tagged type, we must ensure that all the
1898 -- primitive operations of the parent have been frozen, so that
1899 -- their addresses will be in the parent's dispatch table at the
1900 -- point it is inherited.
1906 then
1907 declare
1914 begin
1921 then
1923 Process_Flist;
1933 Process_Flist;
1935 -- If already frozen, and there are delayed aspects, this is where
1936 -- we do the visibility check for these aspects (see Sem_Ch13 spec
1937 -- for a description of how we handle aspect visibility).
1941 -- Retrieve the visibility to the discriminants in order to
1942 -- analyze properly the aspects.
1946 declare
1949 begin
1955 then
1966 -- If an incomplete type is still not frozen, this may be a
1967 -- premature freezing because of a body declaration that follows.
1968 -- Indicate where the freezing took place. Freezing will happen
1969 -- if the body comes from source, but not if it is internally
1970 -- generated, for example as the body of a type invariant.
1972 -- If the freezing is caused by the end of the current declarative
1973 -- part, it is a Taft Amendment type, and there is no error.
1977 then
1978 declare
1981 begin
1982 -- The presence of a body freezes all entities previously
1983 -- declared in the current list of declarations, but this
1984 -- does not apply if the body does not come from source.
1985 -- A type invariant is transformed into a subprogram body
1986 -- which is placed at the end of the private part of the
1987 -- current package, but this body does not freeze incomplete
1988 -- types that may be declared in this private part.
1991 N_Package_Body,
1992 N_Protected_Body,
1993 N_Subprogram_Body,
1994 N_Task_Body)
1996 and then
1999 then
2001 Error_Msg_NE
2012 -- Local variables
2018 -- Start of processing for Freeze_All
2020 begin
2023 -- Now that all types are frozen, we can deal with default expressions
2024 -- that require us to build a default expression functions. This is the
2025 -- point at which such functions are constructed (after all types that
2026 -- might be used in such expressions have been frozen).
2028 -- For subprograms that are renaming_as_body, we create the wrapper
2029 -- bodies as needed.
2031 -- We also add finalization chains to access types whose designated
2032 -- types are controlled. This is normally done when freezing the type,
2033 -- but this misses recursive type definitions where the later members
2034 -- of the recursion introduce controlled components.
2036 -- Loop through entities
2051 else
2057 and then
2059 N_Subprogram_Renaming_Declaration
2060 then
2061 Build_And_Analyze_Renamed_Body
2066 -- Freeze the default expressions of entries, entry families, and
2067 -- protected subprograms.
2074 then
2082 -- Historical note: We used to create a finalization master for an
2083 -- access type whose designated type is not controlled, but contains
2084 -- private controlled compoments. This form of postprocessing is no
2085 -- longer needed because the finalization master is now created when
2086 -- the access type is frozen (see Exp_Ch3.Freeze_Type).
2092 -----------------------
2093 -- Freeze_And_Append --
2094 -----------------------
2096 procedure Freeze_And_Append
2100 is
2102 begin
2106 else
2112 -------------------
2113 -- Freeze_Before --
2114 -------------------
2116 procedure Freeze_Before
2120 is
2121 -- Freeze T, then insert the generated Freeze nodes before the node N.
2122 -- Flag Freeze_Profile is used when T is an overloadable entity, and
2123 -- indicates whether its profile should be frozen at the same time.
2129 begin
2136 -- If the entity is a type declared in an inner package, it may be
2137 -- frozen by an outer declaration before the package itself is
2138 -- frozen. Install the package scope to analyze the freeze nodes,
2139 -- which may include generated subprograms such as predicate
2140 -- functions, etc.
2149 else
2155 -------------------
2156 -- Freeze_Entity --
2157 -------------------
2159 -- WARNING: This routine manages Ghost regions. Return statements must be
2160 -- replaced by gotos which jump to the end of the routine and restore the
2161 -- Ghost mode.
2163 function Freeze_Entity
2167 is
2176 -- This flag gets set to true for a variable with default initialization
2179 -- List of freezing actions, left at No_List if none
2182 -- This could use a comment ???
2185 -- N is a freezing action to be appended to the Result
2188 -- If Loc is a freeze_entity that appears after the last declaration
2189 -- in the scope, inhibit error messages on late completion.
2192 -- Check that an Access or Unchecked_Access attribute with a prefix
2193 -- which is the current instance type can only be applied when the type
2194 -- is limited.
2197 -- Give a warning for pragma Convention with language C or C++ applied
2198 -- to a discriminated record type. This is suppressed for the unchecked
2199 -- union case, since the whole point in this case is interface C. We
2200 -- also do not generate this within instantiations, since we will have
2201 -- generated a message on the template.
2204 -- Give warning for modulus of 8, 16, 32, or 64 given as an explicit
2205 -- integer literal without an explicit corresponding size clause. The
2206 -- caller has checked that Utype is a modular integer type.
2209 -- Freeze array type, including freezing index and component types
2212 -- Perform checks and generate freeze node if needed for a constant or
2213 -- variable declared by an object declaration.
2216 -- Create Freeze_Generic_Entity nodes for types declared in a generic
2217 -- package. Recurse on inner generic packages.
2220 -- Freeze formals and return type of subprogram. If some type in the
2221 -- profile is incomplete and we are in an instance, freezing of the
2222 -- entity will take place elsewhere, and the function returns False.
2225 -- Freeze record type, including freezing component types, and freezing
2226 -- primitive operations if this is a tagged type.
2229 -- Determine whether an arbitrary entity is subject to Boolean aspect
2230 -- Import and its value is specified as True.
2232 procedure Inherit_Freeze_Node
2235 -- Set type Typ's freeze node to refer to Fnode. This routine ensures
2236 -- that any attributes attached to Typ's original node are preserved.
2239 -- If E is an entity for an imported subprogram with pre/post-conditions
2240 -- then this procedure will create a wrapper to ensure that proper run-
2241 -- time checking of the pre/postconditions. See body for details.
2243 -------------------
2244 -- Add_To_Result --
2245 -------------------
2248 begin
2251 else
2256 ----------------------------
2257 -- After_Last_Declaration --
2258 ----------------------------
2263 begin
2269 else
2273 else
2278 ----------------------------
2279 -- Check_Current_Instance --
2280 ----------------------------
2285 -- Determine whether Typ is compatible with the rules for aliased
2286 -- views of types as defined in RM 3.10 in the various dialects.
2289 -- Process routine to apply check to given node
2291 -----------------------------
2292 -- Is_Aliased_View_Of_Type --
2293 -----------------------------
2298 begin
2299 -- Common case
2303 then
2306 -- The following paragraphs describe what a legal aliased view of
2307 -- a type is in the various dialects of Ada.
2309 -- Ada 95
2311 -- The current instance of a limited type, and a formal parameter
2312 -- or generic formal object of a tagged type.
2314 -- Ada 95 limited type
2315 -- * Type with reserved word "limited"
2316 -- * A protected or task type
2317 -- * A composite type with limited component
2322 -- Ada 2005
2324 -- The current instance of a limited tagged type, a protected
2325 -- type, a task type, or a type that has the reserved word
2326 -- "limited" in its full definition ... a formal parameter or
2327 -- generic formal object of a tagged type.
2329 -- Ada 2005 limited type
2330 -- * Type with reserved word "limited", "synchronized", "task"
2331 -- or "protected"
2332 -- * A composite type with limited component
2333 -- * A derived type whose parent is a non-interface limited type
2336 return
2338 or else
2343 -- Ada 2012 and beyond
2345 -- The current instance of an immutably limited type ... a formal
2346 -- parameter or generic formal object of a tagged type.
2348 -- Ada 2012 limited type
2349 -- * Type with reserved word "limited", "synchronized", "task"
2350 -- or "protected"
2351 -- * A composite type with limited component
2352 -- * A derived type whose parent is a non-interface limited type
2353 -- * An incomplete view
2355 -- Ada 2012 immutably limited type
2356 -- * Explicitly limited record type
2357 -- * Record extension with "limited" present
2358 -- * Non-formal limited private type that is either tagged
2359 -- or has at least one access discriminant with a default
2360 -- expression
2361 -- * Task type, protected type or synchronized interface
2362 -- * Type derived from immutably limited type
2364 else
2365 return
2371 -------------
2372 -- Process --
2373 -------------
2376 begin
2380 Name_Unchecked_Access)
2384 then
2386 Error_Msg_N
2389 else
2390 Error_Msg_N
2397 else
2408 -- Local variables
2413 -- Start of processing for Check_Current_Instance
2415 begin
2421 ---------------------------------
2422 -- Check_Suspicious_Convention --
2423 ---------------------------------
2426 begin
2431 or else
2434 and then not In_Instance
2436 then
2437 declare
2442 begin
2447 Error_Msg_N
2450 else
2451 Error_Msg_N
2456 Error_Msg_NE
2464 ------------------------------
2465 -- Check_Suspicious_Modulus --
2466 ------------------------------
2471 begin
2477 declare
2480 begin
2482 declare
2486 begin
2488 declare
2492 begin
2493 -- First case, modulus and size are the same. This
2494 -- happens if you have something like mod 32, with
2495 -- an explicit size of 32, this is for sure a case
2496 -- where the warning is given, since it is seems
2497 -- very unlikely that someone would want e.g. a
2498 -- five bit type stored in 32 bits. It is much
2499 -- more likely they wanted a 32-bit type.
2504 -- Second case, the modulus is 32 or 64 and no
2505 -- size clause is present. This is a less clear
2506 -- case for giving the warning, but in the case
2507 -- of 32/64 (5-bit or 6-bit types) these seem rare
2508 -- enough that it is a likely error (and in any
2509 -- case using 2**5 or 2**6 in these cases seems
2510 -- clearer. We don't include 8 or 16 here, simply
2511 -- because in practice 3-bit and 4-bit types are
2512 -- more common and too many false positives if
2513 -- we warn in these cases.
2517 then
2520 -- No warning needed
2522 else
2526 -- If we fall through, give warning
2529 Error_Msg_N
2531 Modulus);
2540 -----------------------
2541 -- Freeze_Array_Type --
2542 -----------------------
2550 -- Set true if any of the index types is an enumeration type with a
2551 -- non-standard representation.
2553 begin
2562 then
2569 -- Processing that is done only for base types
2573 -- Deal with default setting of reverse storage order
2577 -- Propagate flags for component type
2581 then
2589 -- The array type requires its own invariant procedure in order to
2590 -- verify the component invariant over all elements. In GNATprove
2591 -- mode, the component invariants are checked by other means. They
2592 -- should not be added to the array type invariant procedure, so
2593 -- that the procedure can be used to check the array type
2594 -- invariants if any.
2597 and then not GNATprove_Mode
2598 then
2601 -- The array type is an implementation base type. Propagate the
2602 -- same property to the first subtype.
2609 -- Warn for pragma Pack overriding foreign convention
2613 then
2614 declare
2619 begin
2623 Error_Msg_N
2626 Error_Msg_N
2633 -- If packing was requested or if the component size was
2634 -- set explicitly, then see if bit packing is required. This
2635 -- processing is only done for base types, since all of the
2636 -- representation aspects involved are type-related.
2638 -- This is not just an optimization, if we start processing the
2639 -- subtypes, they interfere with the settings on the base type
2640 -- (this is because Is_Packed has a slightly different meaning
2641 -- before and after freezing).
2643 declare
2647 begin
2651 then
2660 else
2663 -- We can set the component size if it is less than 16,
2664 -- rounding it up to the next storage unit size.
2670 else
2674 -- Set component size up to match alignment if it would
2675 -- otherwise be less than the alignment. This deals with
2676 -- cases of types whose alignment exceeds their size (the
2677 -- padded type cases).
2680 declare
2682 begin
2690 -- Case of component size that may result in bit packing
2693 declare
2699 Get_Attribute_Definition_Clause
2702 begin
2703 -- Warn if we have pack and component size so that the
2704 -- pack is ignored.
2706 -- Note: here we must check for the presence of a
2707 -- component size before checking for a Pack pragma to
2708 -- deal with the case where the array type is a derived
2709 -- type whose parent is currently private.
2713 and then Warn_On_Redundant_Constructs
2714 then
2716 Error_Msg_NE
2718 Error_Msg_N
2724 -- Set component size if not already set by a component
2725 -- size clause.
2731 -- Check for base type of 8, 16, 32 bits, where an
2732 -- unsigned subtype has a length one less than the
2733 -- base type (e.g. Natural subtype of Integer).
2735 -- In such cases, if a component size was not set
2736 -- explicitly, then generate a warning.
2742 then
2746 Error_Msg_N
2748 Pack_Pragma);
2749 Error_Msg_N
2751 Pack_Pragma);
2755 -- Bit packing is never needed for 8, 16, 32, 64
2759 -- If the Esize of the component is known and equal to
2760 -- the component size then even packing is not needed.
2764 then
2765 -- Here the array was requested to be packed, but
2766 -- the packing request had no effect whatsoever,
2767 -- so flag Is_Packed is reset.
2769 -- Note: semantically this means that we lose track
2770 -- of the fact that a derived type inherited pragma
2771 -- Pack that was non-effective, but that is fine.
2773 -- We regard a Pack pragma as a request to set a
2774 -- representation characteristic, and this request
2775 -- may be ignored.
2779 else
2786 -- Bit packing is not needed for multiples of the storage
2787 -- unit if the type is composite because the back end can
2788 -- byte pack composite types.
2792 then
2797 -- In all other cases, bit packing is needed
2799 else
2808 -- Check for Aliased or Atomic_Components/Atomic/VFA with
2809 -- unsuitable packing or explicit component size clause given.
2814 and then
2816 then
2820 -- Outputs error messages for incorrect CS clause or pragma
2821 -- Pack for aliased or atomic/VFA components (T is "aliased"
2822 -- or "atomic/vfa");
2824 -----------------
2825 -- Complain_CS --
2826 -----------------
2829 begin
2831 Clause :=
2832 Get_Attribute_Definition_Clause
2835 Error_Msg_N
2839 Error_Msg_N
2842 else
2843 Error_Msg_N
2849 -- Start of processing for Alias_Atomic_Check
2851 begin
2852 -- If object size of component type isn't known, we cannot
2853 -- be sure so we defer to the back end.
2858 -- Case where component size has no effect. First check for
2859 -- object size of component type multiple of the storage
2860 -- unit size.
2864 -- OK in both packing case and component size case if RM
2865 -- size is known and static and same as the object size.
2867 and then
2871 -- Or if we have an explicit component size clause and
2872 -- the component size and object size are equal.
2874 or else
2877 then
2885 then
2894 -- Check for Independent_Components/Independent with unsuitable
2895 -- packing or explicit component size clause given.
2898 and then
2900 then
2901 begin
2902 -- If object size of component type isn't known, we cannot
2903 -- be sure so we defer to the back end.
2908 -- Case where component size has no effect. First check for
2909 -- object size of component type multiple of the storage
2910 -- unit size.
2914 -- OK in both packing case and component size case if RM
2915 -- size is known and multiple of the storage unit size.
2917 and then
2921 -- Or if we have an explicit component size clause and
2922 -- the component size is larger than the object size.
2924 or else
2927 then
2930 else
2932 Clause :=
2933 Get_Attribute_Definition_Clause
2936 Error_Msg_N
2940 Error_Msg_N
2943 else
2944 Error_Msg_N
2952 -- Warn for case of atomic type
2958 then
2959 Error_Msg_NE
2974 -- Check for scalar storage order
2976 declare
2978 begin
2979 Check_Component_Storage_Order
2982 ADC => Get_Attribute_Definition_Clause
2984 Attribute_Scalar_Storage_Order),
2988 -- Processing that is done only for subtypes
2990 else
2991 -- Acquire alignment from base type
2999 -- Specific checks for bit-packed arrays
3003 -- Check number of elements for bit-packed arrays that come from
3004 -- source and have compile time known ranges. The bit-packed
3005 -- arrays circuitry does not support arrays with more than
3006 -- Integer'Last + 1 elements, and when this restriction is
3007 -- violated, causes incorrect data access.
3009 -- For the case where this is not compile time known, a run-time
3010 -- check should be generated???
3013 declare
3019 begin
3025 -- Never generate an error if any index is of a generic
3026 -- type. We will check this in instances.
3033 Ilen :=
3039 -- No attempt is made to check number of elements if not
3040 -- compile time known.
3053 then
3054 Error_Msg_N
3061 -- Check size
3064 declare
3068 begin
3069 -- It is not clear if it is possible to have no size clause
3070 -- at this stage, but it is not worth worrying about. Post
3071 -- error on the entity name in the size clause if present,
3072 -- else on the type entity itself.
3076 else
3083 -- If any of the index types was an enumeration type with a non-
3084 -- standard rep clause, then we indicate that the array type is
3085 -- always packed (even if it is not bit-packed).
3094 -- If the array is packed and bit-packed or packed to eliminate holes
3095 -- in the non-contiguous enumeration index types, we must create the
3096 -- packed array type to be used to actually implement the type. This
3097 -- is only needed for real array types (not for string literal types,
3098 -- since they are present only for the front end).
3103 then
3107 -- Make sure that we have the necessary routines to implement the
3108 -- packing, and complain now if not. Note that we only test this
3109 -- for constrained array types.
3115 then
3116 declare
3120 begin
3123 then
3124 Error_Msg_CRT
3128 -- Cancel the packing
3138 -- Size information of packed array type is copied to the array
3139 -- type, since this is really the representation. But do not
3140 -- override explicit existing size values. If the ancestor subtype
3141 -- is constrained the Packed_Array_Impl_Type will be inherited
3142 -- from it, but the size may have been provided already, and
3143 -- must not be overridden either.
3146 and then
3149 then
3161 -- For non-packed arrays set the alignment of the array to the
3162 -- alignment of the component type if it is unknown. Skip this
3163 -- in atomic/VFA case (atomic/VFA arrays may need larger alignments).
3172 then
3176 -- A Ghost type cannot have a component of protected or task type
3177 -- (SPARK RM 6.9(19)).
3180 Error_Msg_N
3182 Arr);
3186 -------------------------------
3187 -- Freeze_Object_Declaration --
3188 -------------------------------
3191 begin
3192 -- Abstract type allowed only for C++ imported variables or constants
3194 -- Note: we inhibit this check for objects that do not come from
3195 -- source because there is at least one case (the expansion of
3196 -- x'Class'Input where x is abstract) where we legitimately
3197 -- generate an abstract object.
3202 then
3207 Error_Msg_NE
3212 Error_Msg_N -- CODEFIX
3218 -- For object created by object declaration, perform required
3219 -- categorization (preelaborate and pure) checks. Defer these
3220 -- checks to freeze time since pragma Import inhibits default
3221 -- initialization and thus pragma Import affects these checks.
3225 -- If there is an address clause, check that it is valid
3226 -- and if need be move initialization to the freeze node.
3230 -- Similar processing is needed for aspects that may affect
3231 -- object layout, like Alignment, if there is an initialization
3232 -- expression. We don't do this if there is a pragma Linker_Section,
3233 -- because it would prevent the back end from statically initializing
3234 -- the object; we don't want elaboration code in that case.
3237 and then Expander_Active
3241 then
3242 declare
3246 begin
3248 -- Capture initialization value at point of declaration, and
3249 -- make explicit assignment legal, because object may be a
3250 -- constant.
3255 -- Move initialization to freeze actions.
3263 -- Set_Is_Frozen (E, False);
3267 -- Reset Is_True_Constant for non-constant aliased object. We
3268 -- consider that the fact that a non-constant object is aliased may
3269 -- indicate that some funny business is going on, e.g. an aliased
3270 -- object is passed by reference to a procedure which captures the
3271 -- address of the object, which is later used to assign a new value,
3272 -- even though the compiler thinks that it is not modified. Such
3273 -- code is highly dubious, but we choose to make it "work" for
3274 -- non-constant aliased objects.
3276 -- Note that we used to do this for all aliased objects, whether or
3277 -- not constant, but this caused anomalies down the line because we
3278 -- ended up with static objects that were not Is_True_Constant. Not
3279 -- resetting Is_True_Constant for (aliased) constant objects ensures
3280 -- that this anomaly never occurs.
3282 -- However, we don't do that for internal entities. We figure that if
3283 -- we deliberately set Is_True_Constant for an internal entity, e.g.
3284 -- a dispatch table entry, then we mean it.
3289 then
3293 -- If the object needs any kind of default initialization, an error
3294 -- must be issued if No_Default_Initialization applies. The check
3295 -- doesn't apply to imported objects, which are not ever default
3296 -- initialized, and is why the check is deferred until freezing, at
3297 -- which point we know if Import applies. Deferred constants are also
3298 -- exempted from this test because their completion is explicit, or
3299 -- through an import pragma.
3307 and then
3311 or else
3314 then
3316 Check_Restriction
3320 -- Check that a Thread_Local_Storage variable does not have
3321 -- default initialization, and any explicit initialization must
3322 -- either be the null constant or a static constant.
3325 declare
3327 begin
3328 if Has_Default_Initialization
3329 or else
3331 and then
3333 or else not
3336 then
3337 Error_Msg_NE
3340 Error_Msg_NE
3347 -- For imported objects, set Is_Public unless there is also an
3348 -- address clause, which means that there is no external symbol
3349 -- needed for the Import (Is_Public may still be set for other
3350 -- unrelated reasons). Note that we delayed this processing
3351 -- till freeze time so that we can be sure not to set the flag
3352 -- if there is an address clause. If there is such a clause,
3353 -- then the only purpose of the Import pragma is to suppress
3354 -- implicit initialization.
3360 -- For source objects that are not Imported and are library
3361 -- level, if no linker section pragma was given inherit the
3362 -- appropriate linker section from the corresponding type.
3368 then
3369 Set_Linker_Section_Pragma
3373 -- For convention C objects of an enumeration type, warn if the
3374 -- size is not integer size and no explicit size given. Skip
3375 -- warning for Boolean, and Character, assume programmer expects
3376 -- 8-bit sizes for these cases.
3379 or else
3386 then
3388 Error_Msg_N
3394 -----------------------------
3395 -- Freeze_Generic_Entities --
3396 -----------------------------
3403 begin
3422 --------------------
3423 -- Freeze_Profile --
3424 --------------------
3431 begin
3432 -- Loop through formals
3438 -- AI05-0151: incomplete types can appear in a profile. By the
3439 -- time the entity is frozen, the full view must be available,
3440 -- unless it is a limited view.
3445 then
3459 then
3460 -- If the type of a formal is incomplete, subprogram is being
3461 -- frozen prematurely. Within an instance (but not within a
3462 -- wrapper package) this is an artifact of our need to regard
3463 -- the end of an instantiation as a freeze point. Otherwise it
3464 -- is a definite error.
3471 elsif not After_Last_Declaration
3472 and then not Freezing_Library_Level_Tagged_Type
3473 then
3475 Error_Msg
3480 -- Check suspicious parameter for C function. These tests apply
3481 -- only to exported/imported subprograms.
3483 if Warn_On_Export_Import
3486 or else
3493 then
3494 -- Qualify mention of formals with subprogram name
3498 -- Check suspicious use of fat C pointer
3502 then
3503 Error_Msg_N
3506 -- Check suspicious return of boolean
3512 then
3513 Error_Msg_N
3515 Error_Msg_N
3519 -- Check suspicious tagged type
3522 or else
3526 then
3527 Error_Msg_N
3531 -- Check wrong convention subprogram pointer
3535 then
3536 Error_Msg_N
3540 Error_Msg_NE
3545 -- Turn off name qualification after message output
3550 -- Check for unconstrained array in exported foreign convention
3551 -- case.
3557 and then Warn_On_Export_Import
3558 then
3561 -- If this is an inherited operation, place the warning on
3562 -- the derived type declaration, rather than on the original
3563 -- subprogram.
3566 then
3572 else
3588 -- If the formal is an anonymous_access_to_subprogram
3589 -- freeze the subprogram type as well, to prevent
3590 -- scope anomalies in gigi, because there is no other
3591 -- clear point at which it could be frozen.
3595 then
3603 -- Case of function: similar checks on return type
3607 -- Freeze return type
3611 -- AI05-0151: the return type may have been incomplete at the
3612 -- point of declaration. Replace it with the full view, unless the
3613 -- current type is a limited view. In that case the full view is
3614 -- in a different unit, and gigi finds the non-limited view after
3615 -- the other unit is elaborated.
3620 then
3627 -- Check suspicious return type for C function
3629 if Warn_On_Export_Import
3631 or else
3634 then
3635 -- Check suspicious return of fat C pointer
3641 then
3642 Error_Msg_N
3644 E);
3646 -- Check suspicious return of boolean
3653 then
3654 declare
3657 begin
3658 Error_Msg_NE
3660 Error_Msg_NE
3665 -- Check suspicious return tagged type
3669 and then
3670 Is_Tagged_Type
3675 then
3679 -- Check return of wrong convention subprogram pointer
3685 then
3689 Error_Msg_NE
3695 -- Give warning for suspicious return of a result of an
3696 -- unconstrained array type in a foreign convention function.
3700 -- We are looking for a return of unconstrained array
3705 -- Exclude imported routines, the warning does not belong on
3706 -- the import, but rather on the routine definition.
3710 -- Check that general warning is enabled, and that it is not
3711 -- suppressed for this particular case.
3713 and then Warn_On_Export_Import
3716 then
3717 Error_Msg_N
3723 -- Check suspicious use of Import in pure unit (cases where the RM
3724 -- allows calls to be omitted).
3728 -- It might be suspicious if the compilation unit has the Pure
3729 -- aspect/pragma.
3733 -- The RM allows omission of calls only in the case of
3734 -- library-level subprograms (see RM-10.2.1(18)).
3738 -- Ignore internally generated entity. This happens in some cases
3739 -- of subprograms in specs, where we generate an implied body.
3743 -- Assume run-time knows what it is doing
3745 and then not GNAT_Mode
3747 -- Assume explicit Pure_Function means import is pure
3751 -- Don't need warning in relaxed semantics mode
3753 and then not Relaxed_RM_Semantics
3755 -- Assume convention Intrinsic is OK, since this is specialized.
3756 -- This deals with the DEC unit current_exception.ads
3760 -- Assume that ASM interface knows what it is doing. This deals
3761 -- with e.g. unsigned.ads in the AAMP back end.
3764 then
3765 Error_Msg_N
3767 Error_Msg_NE
3775 ------------------------
3776 -- Freeze_Record_Type --
3777 ------------------------
3789 -- Set True if we find at least one component which is aliased. This
3790 -- is used to prevent Implicit_Packing of the record, since packing
3791 -- cannot modify the size of alignment of an aliased component.
3794 -- True if all components are of a type whose underlying type is
3795 -- elementary.
3798 -- True if all components have a known RM_Size
3801 -- True if all components have an RM_Size that is a multiple of the
3802 -- storage unit.
3805 -- Accumulates total Esize values of all elementary components. Used
3806 -- for processing of Implicit_Packing.
3809 -- Set True if we find at least one component with a component
3810 -- clause (used to warn about useless Bit_Order pragmas, and also
3811 -- to detect cases where Implicit_Packing may have an effect).
3814 -- Set True if the record type scope Rec has been pushed on the scope
3815 -- stack. Needed for the analysis of delayed aspects specified to the
3816 -- components of Rec.
3819 -- Accumulates total RM_Size values of all sized components. Used
3820 -- for processing of Implicit_Packing.
3823 -- Accumulates total RM_Size values of all sized components, rounded
3824 -- individually to a multiple of the storage unit.
3827 -- Scalar_Storage_Order attribute definition clause for the record
3830 -- Set True if we find at least one component whose type has a
3831 -- Scalar_Storage_Order attribute definition clause.
3834 -- Set True if we find at least one component with no component
3835 -- clause (used to warn about useless Pack pragmas).
3838 -- If N is an allocator, possibly wrapped in one or more level of
3839 -- qualified expression(s), return the inner allocator node, else
3840 -- return Empty.
3843 -- If the component subtype is an access to a constrained subtype of
3844 -- an already frozen type, make the subtype frozen as well. It might
3845 -- otherwise be frozen in the wrong scope, and a freeze node on
3846 -- subtype has no effect. Similarly, if the component subtype is a
3847 -- regular (not protected) access to subprogram, set the anonymous
3848 -- subprogram type to frozen as well, to prevent an out-of-scope
3849 -- freeze node at some eventual point of call. Protected operations
3850 -- are handled elsewhere.
3853 -- Make sure that all types mentioned in Discrete_Choices of the
3854 -- variants referenceed by the Variant_Part VP are frozen. This is
3855 -- a recursive routine to deal with nested variants.
3857 ---------------------
3858 -- Check_Allocator --
3859 ---------------------
3863 begin
3865 loop
3870 else
3876 -----------------
3877 -- Check_Itype --
3878 -----------------
3883 begin
3886 then
3889 -- In addition, add an Itype_Reference to ensure that the
3890 -- access subtype is elaborated early enough. This cannot be
3891 -- done if the subtype may depend on discriminants.
3896 then
3904 then
3909 ------------------------------------
3910 -- Freeze_Choices_In_Variant_Part --
3911 ------------------------------------
3920 begin
3921 -- Loop through variants
3926 -- Loop through choices, checking that all types are frozen
3932 then
3939 -- Check for nested variant part to process
3953 -- Start of processing for Freeze_Record_Type
3955 begin
3956 -- Deal with delayed aspect specifications for components. The
3957 -- analysis of the aspect is required to be delayed to the freeze
3958 -- point, thus we analyze the pragma or attribute definition
3959 -- clause in the tree at this point. We also analyze the aspect
3960 -- specification node at the freeze point when the aspect doesn't
3961 -- correspond to pragma/attribute definition clause.
3967 then
3972 -- The visibility to the discriminants must be restored in
3973 -- order to properly analyze the aspects.
3986 -- Pop the scope if Rec scope has been pushed on the scope stack
3987 -- during the delayed aspect analysis process.
3994 Pop_Scope;
3997 -- Freeze components and embedded subtypes
4006 -- Handle the component and discriminant case
4009 declare
4012 begin
4013 -- Freezing a record type freezes the type of each of its
4014 -- components. However, if the type of the component is
4015 -- part of this record, we do not want or need a separate
4016 -- Freeze_Node. Note that Is_Itype is wrong because that's
4017 -- also set in private type cases. We also can't check for
4018 -- the Scope being exactly Rec because of private types and
4019 -- record extensions.
4024 then
4030 -- Warn for pragma Pack overriding foreign convention
4035 -- Don't warn for aliased components, since override
4036 -- cannot happen in that case.
4039 then
4040 declare
4045 begin
4049 Error_Msg_N
4051 PP);
4053 Error_Msg_NE
4060 -- Check for error of component clause given for variable
4061 -- sized type. We have to delay this test till this point,
4062 -- since the component type has to be frozen for us to know
4063 -- if it is variable length.
4068 -- We omit this test in a generic context, it will be
4069 -- applied at instantiation time.
4074 -- Also omit this test in CodePeer mode, since we do not
4075 -- have sufficient info on size and rep clauses.
4080 -- Omit check if component has a generic type. This can
4081 -- happen in an instantiation within a generic in ASIS
4082 -- mode, where we force freeze actions without full
4083 -- expansion.
4088 -- Do the check
4090 elsif not
4091 Size_Known_At_Compile_Time
4093 then
4094 Error_Msg_N
4099 else
4103 -- Case of component requires byte alignment
4107 -- Set the enclosing record to also require byte align
4111 -- Check for component clause that is inconsistent with
4112 -- the required byte boundary alignment.
4117 then
4118 Error_Msg_N
4126 -- Gather data for possible Implicit_Packing later. Note that at
4127 -- this stage we might be dealing with a real component, or with
4128 -- an implicit subtype declaration.
4131 declare
4136 begin
4137 Sized_Component_Total_RM_Size :=
4140 Sized_Component_Total_Round_RM_Size :=
4141 Sized_Component_Total_Round_RM_Size +
4146 then
4147 Elem_Component_Total_Esize :=
4149 else
4157 else
4161 -- If the component is an Itype with Delayed_Freeze and is either
4162 -- a record or array subtype and its base type has not yet been
4163 -- frozen, we must remove this from the entity list of this record
4164 -- and put it on the entity list of the scope of its base type.
4165 -- Note that we know that this is not the type of a component
4166 -- since we cleared Has_Delayed_Freeze for it in the previous
4167 -- loop. Thus this must be the Designated_Type of an access type,
4168 -- which is the type of a component.
4176 then
4177 declare
4181 begin
4182 -- We have a difficult case to handle here. Suppose Rec is
4183 -- subtype being defined in a subprogram that's created as
4184 -- part of the freezing of Rec'Base. In that case, we know
4185 -- that Comp'Base must have already been frozen by the time
4186 -- we get to elaborate this because Gigi doesn't elaborate
4187 -- any bodies until it has elaborated all of the declarative
4188 -- part. But Is_Frozen will not be set at this point because
4189 -- we are processing code in lexical order.
4191 -- We detect this case by going up the Scope chain of Rec
4192 -- and seeing if we have a subprogram scope before reaching
4193 -- the top of the scope chain or that of Comp'Base. If we
4194 -- do, then mark that Comp'Base will actually be frozen. If
4195 -- so, we merely undelay it.
4212 else
4215 else
4219 -- Insert in entity list of scope of base type (which
4220 -- must be an enclosing scope, because still unfrozen).
4226 -- If the component is an access type with an allocator as default
4227 -- value, the designated type will be frozen by the corresponding
4228 -- expression in init_proc. In order to place the freeze node for
4229 -- the designated type before that for the current record type,
4230 -- freeze it now.
4232 -- Same process if the component is an array of access types,
4233 -- initialized with an aggregate. If the designated type is
4234 -- private, it cannot contain allocators, and it is premature
4235 -- to freeze the type, so we check for this as well.
4240 then
4241 declare
4245 begin
4248 -- If component is pointer to a class-wide type, freeze
4249 -- the specific type in the expression being allocated.
4250 -- The expression may be a subtype indication, in which
4251 -- case freeze the subtype mark.
4253 if Is_Class_Wide_Type
4255 then
4257 Freeze_And_Append
4261 then
4262 Freeze_And_Append
4270 else
4271 Freeze_And_Append
4279 then
4282 -- Freeze the designated type when initializing a component with
4283 -- an aggregate in case the aggregate contains allocators.
4285 -- type T is ...;
4286 -- type T_Ptr is access all T;
4287 -- type T_Array is array ... of T_Ptr;
4289 -- type Rec is record
4290 -- Comp : T_Array := (others => ...);
4291 -- end record;
4295 then
4296 declare
4299 Designated_Type
4302 begin
4303 -- The only case when this sort of freezing is not done is
4304 -- when the designated type is class-wide and the root type
4305 -- is the record owning the component. This scenario results
4306 -- in a circularity because the class-wide type requires
4307 -- primitives that have not been created yet as the root
4308 -- type is in the process of being frozen.
4310 -- type Rec is tagged;
4311 -- type Rec_Ptr is access all Rec'Class;
4312 -- type Rec_Array is array ... of Rec_Ptr;
4314 -- type Rec is record
4315 -- Comp : Rec_Array := (others => ...);
4316 -- end record;
4320 then
4328 then
4338 SSO_ADC :=
4339 Get_Attribute_Definition_Clause
4342 -- If the record type has Complex_Representation, then it is treated
4343 -- as a scalar in the back end so the storage order is irrelevant.
4347 Error_Msg_N
4349 SSO_ADC);
4352 else
4353 -- Deal with default setting of reverse storage order
4357 -- Check consistent attribute setting on component types
4359 declare
4361 begin
4364 Check_Component_Storage_Order
4374 -- Now deal with reverse storage order/bit order issues
4378 -- Check compatibility of Scalar_Storage_Order with Bit_Order,
4379 -- if the former is specified.
4383 -- Note: report error on Rec, not on SSO_ADC, as ADC may
4384 -- apply to some ancestor type.
4387 Error_Msg_N
4392 -- Warn if there is a Scalar_Storage_Order attribute definition
4393 -- clause but no component clause, no component that itself has
4394 -- such an attribute definition, and no pragma Pack.
4397 or else
4398 SSO_ADC_Component
4399 or else
4401 then
4402 Error_Msg_N
4409 -- Deal with Bit_Order aspect
4417 then
4418 -- Warn if clause has no effect when no component clause is
4419 -- present, but suppress warning if the Bit_Order is required
4420 -- due to the presence of a Scalar_Storage_Order attribute.
4422 Error_Msg_N
4424 Error_Msg_N
4427 -- Here is where we do the processing to adjust component clauses
4428 -- for reversed bit order, when not using reverse SSO. If an error
4429 -- has been reported on Rec already (such as SSO incompatible with
4430 -- bit order), don't bother adjusting as this may generate extra
4431 -- noise.
4436 then
4439 -- Case where we have both an explicit Bit_Order and the same
4440 -- Scalar_Storage_Order: leave record untouched, the back-end
4441 -- will take care of required layout conversions.
4443 else
4449 -- Complete error checking on record representation clause (e.g.
4450 -- overlap of components). This is called after adjusting the
4451 -- record for reverse bit order.
4453 declare
4455 begin
4461 -- Check for useless pragma Pack when all components placed. We only
4462 -- do this check for record types, not subtypes, since a subtype may
4463 -- have all its components placed, and it still makes perfectly good
4464 -- sense to pack other subtypes or the parent type. We do not give
4465 -- this warning if Optimize_Alignment is set to Space, since the
4466 -- pragma Pack does have an effect in this case (it always resets
4467 -- the alignment to one).
4471 and then not Unplaced_Component
4473 then
4474 -- Reset packed status. Probably not necessary, but we do it so
4475 -- that there is no chance of the back end doing something strange
4476 -- with this redundant indication of packing.
4480 -- Give warning if redundant constructs warnings on
4483 Error_Msg_N -- CODEFIX
4489 -- If this is the record corresponding to a remote type, freeze the
4490 -- remote type here since that is what we are semantically freezing.
4491 -- This prevents the freeze node for that type in an inner scope.
4498 -- Check for controlled components, unchecked unions, and type
4499 -- invariants.
4504 -- Do not set Has_Controlled_Component on a class-wide
4505 -- equivalent type. See Make_CW_Equivalent_Type.
4508 and then
4510 or else
4513 or else
4515 and then
4517 and then
4518 Has_Controlled_Component
4520 then
4528 -- The record type requires its own invariant procedure in
4529 -- order to verify the invariant of each individual component.
4530 -- Do not consider internal components such as _parent because
4531 -- parent class-wide invariants are always inherited.
4532 -- In GNATprove mode, the component invariants are checked by
4533 -- other means. They should not be added to the record type
4534 -- invariant procedure, so that the procedure can be used to
4535 -- check the recordy type invariants if any.
4539 and then not GNATprove_Mode
4540 then
4544 -- Scan component declaration for likely misuses of current
4545 -- instance, either in a constraint or a default expression.
4555 -- Enforce the restriction that access attributes with a current
4556 -- instance prefix can only apply to limited types. This comment
4557 -- is floating here, but does not seem to belong here???
4559 -- Set component alignment if not otherwise already set
4563 -- For first subtypes, check if there are any fixed-point fields with
4564 -- component clauses, where we must check the size. This is not done
4565 -- till the freeze point since for fixed-point types, we do not know
4566 -- the size until the type is frozen. Similar processing applies to
4567 -- bit-packed arrays.
4575 then
4576 Check_Size
4580 Junk);
4587 -- See if Size is too small as is (and implicit packing might help)
4591 -- No implicit packing if even one component is explicitly placed
4593 and then not Placed_Component
4595 -- Or even one component is aliased
4597 and then not Aliased_Component
4599 -- Must have size clause and all sized components
4602 and then All_Sized_Components
4604 -- Do not try implicit packing on records with discriminants, too
4605 -- complicated, especially in the variant record case.
4609 -- We want to implicitly pack if the specified size of the record
4610 -- is less than the sum of the object sizes (no point in packing
4611 -- if this is not the case), if we can compute it, i.e. if we have
4612 -- only elementary components. Otherwise, we have at least one
4613 -- composite component and we want to implicitly pack only if bit
4614 -- packing is required for it, as we are sure in this case that
4615 -- the back end cannot do the expected layout without packing.
4617 and then
4618 ((All_Elem_Components
4620 or else
4622 and then not All_Storage_Unit_Components
4625 -- And the total RM size cannot be greater than the specified size
4626 -- since otherwise packing will not get us where we have to be.
4630 -- Never do implicit packing in CodePeer or SPARK modes since
4631 -- we don't do any packing in these modes, since this generates
4632 -- over-complex code that confuses static analysis, and in
4633 -- general, neither CodePeer not GNATprove care about the
4634 -- internal representation of objects.
4637 then
4638 -- If implicit packing enabled, do it
4643 -- Otherwise flag the size clause
4645 else
4646 declare
4648 begin
4649 Error_Msg_NE -- CODEFIX
4651 Error_Msg_N -- CODEFIX
4658 -- The following checks are relevant only when SPARK_Mode is on as
4659 -- they are not standard Ada legality rules.
4663 -- A discriminated type cannot be effectively volatile
4664 -- (SPARK RM 7.1.3(5)).
4671 -- A non-effectively volatile record type cannot contain
4672 -- effectively volatile components (SPARK RM 7.1.3(6)).
4674 else
4679 then
4681 Error_Msg_N
4690 -- A type which does not yield a synchronized object cannot have
4691 -- a component that yields a synchronized object (SPARK RM 9.5).
4698 then
4700 Error_Msg_N
4709 -- A Ghost type cannot have a component of protected or task type
4710 -- (SPARK RM 6.9(19)).
4717 then
4719 Error_Msg_N
4721 Comp);
4729 -- Make sure that if we have an iterator aspect, then we have
4730 -- either Constant_Indexing or Variable_Indexing.
4732 declare
4735 begin
4744 or else
4746 then
4748 else
4749 Error_Msg_N
4751 Iterator_Aspect);
4756 -- All done if not a full record definition
4762 -- Finally we need to check the variant part to make sure that
4763 -- all types within choices are properly frozen as part of the
4764 -- freezing of the record type.
4771 begin
4772 -- Find component list
4784 then
4789 -- Case of variant part present
4795 -- Note: we used to call Check_Choices here, but it is too early,
4796 -- since predicated subtypes are frozen here, but their freezing
4797 -- actions are in Analyze_Freeze_Entity, which has not been called
4798 -- yet for entities frozen within this procedure, so we moved that
4799 -- call to the Analyze_Freeze_Entity for the record type.
4803 -- Check that all the primitives of an interface type are abstract
4804 -- or null procedures.
4808 then
4809 declare
4813 begin
4820 -- Avoid reporting the error on inherited primitives
4823 then
4828 Error_Msg_N
4832 else
4833 Error_Msg_N
4844 -- For a derived tagged type, check whether inherited primitives
4845 -- might require a wrapper to handle class-wide conditions.
4852 -------------------------------
4853 -- Has_Boolean_Aspect_Import --
4854 -------------------------------
4861 begin
4867 -- The value of aspect Import is True when the expression is
4868 -- either missing or it is explicitly set to True.
4874 then
4885 -------------------------
4886 -- Inherit_Freeze_Node --
4887 -------------------------
4889 procedure Inherit_Freeze_Node
4892 is
4895 begin
4899 -- The input type had an existing node. Propagate relevant attributes
4900 -- from the old freeze node to the inherited freeze node.
4902 -- ??? if both freeze nodes have attributes, would they differ?
4906 -- Attribute Access_Types_To_Process
4910 then
4915 -- Attribute Actions
4921 -- Attribute First_Subtype_Link
4925 then
4929 -- Attribute TSS_Elist
4933 then
4939 ------------------------------
4940 -- Wrap_Imported_Subprogram --
4941 ------------------------------
4943 -- The issue here is that our normal approach of checking preconditions
4944 -- and postconditions does not work for imported procedures, since we
4945 -- are not generating code for the body. To get around this we create
4946 -- a wrapper, as shown by the following example:
4948 -- procedure K (A : Integer);
4949 -- pragma Import (C, K);
4951 -- The spec is rewritten by removing the effects of pragma Import, but
4952 -- leaving the convention unchanged, as though the source had said:
4954 -- procedure K (A : Integer);
4955 -- pragma Convention (C, K);
4957 -- and we create a body, added to the entity K freeze actions, which
4958 -- looks like:
4960 -- procedure K (A : Integer) is
4961 -- procedure K (A : Integer);
4962 -- pragma Import (C, K);
4963 -- begin
4964 -- K (A);
4965 -- end K;
4967 -- Now the contract applies in the normal way to the outer procedure,
4968 -- and the inner procedure has no contracts, so there is no problem
4969 -- in just calling it to get the original effect.
4971 -- In the case of a function, we create an appropriate return statement
4972 -- for the subprogram body that calls the inner procedure.
4976 -- Obtain a copy of the Import_Pragma which belongs to subprogram E
4978 ------------------------
4979 -- Copy_Import_Pragma --
4980 ------------------------
4984 -- The subprogram should have an import pragma, otherwise it does
4985 -- need a wrapper.
4990 -- Save all semantic fields of the pragma
4999 begin
5000 -- Reset all semantic fields. This avoids a potential infinite
5001 -- loop when the pragma comes from an aspect as the duplication
5002 -- will copy the aspect, then copy the corresponding pragma and
5003 -- so on.
5012 -- Restore the original semantic fields
5022 -- Local variables
5033 -- Start of processing for Wrap_Imported_Subprogram
5035 begin
5036 -- Nothing to do if not imported
5041 -- Test enabling conditions for wrapping
5046 and then not GNATprove_Mode
5047 then
5048 -- Here we do the wrap
5050 -- Note on calls to Copy_Separate_Tree. The trees we are copying
5051 -- here are fully analyzed, but we definitely want fully syntactic
5052 -- unanalyzed trees in the body we construct, so that the analysis
5053 -- generates the right visibility, and that is exactly what the
5054 -- calls to Copy_Separate_Tree give us.
5058 -- Fix up spec so it is no longer imported and has convention Ada
5066 -- Grab the subprogram declaration and specification
5070 -- Build parameter list that we need
5079 -- Build the call
5082 Stmt :=
5084 Expression =>
5089 else
5090 Stmt :=
5096 -- Now build the body
5098 Bod :=
5100 Specification =>
5105 Prag),
5106 Handled_Statement_Sequence =>
5111 -- Append the body to freeze result
5116 -- Case of imported subprogram that does not get wrapped
5118 else
5119 -- Set Is_Public. All imported entities need an external symbol
5120 -- created for them since they are always referenced from another
5121 -- object file. Note this used to be set when we set Is_Imported
5122 -- back in Sem_Prag, but now we delay it to this point, since we
5123 -- don't want to set this flag if we wrap an imported subprogram.
5129 -- Local variables
5132 -- Save the Ghost mode to restore on exit
5134 -- Start of processing for Freeze_Entity
5136 begin
5137 -- The entity being frozen may be subject to pragma Ghost. Set the mode
5138 -- now to ensure that any nodes generated during freezing are properly
5139 -- flagged as Ghost.
5143 -- We are going to test for various reasons why this entity need not be
5144 -- frozen here, but in the case of an Itype that's defined within a
5145 -- record, that test actually applies to the record.
5151 then
5155 -- Do not freeze if already frozen since we only need one freeze node
5165 -- It is improper to freeze an external entity within a generic because
5166 -- its freeze node will appear in a non-valid context. The entity will
5167 -- be frozen in the proper scope after the current generic is analyzed.
5168 -- However, aspects must be analyzed because they may be queried later
5169 -- within the generic itself, and the corresponding pragma or attribute
5170 -- definition has not been analyzed yet.
5180 -- AI05-0213: A formal incomplete type does not freeze the actual. In
5181 -- the instance, the same applies to the subtype renaming the actual.
5187 then
5191 -- Formal subprograms are never frozen
5197 -- Generic types are never frozen as they lack delayed semantic checks
5203 -- Do not freeze a global entity within an inner scope created during
5204 -- expansion. A call to subprogram E within some internal procedure
5205 -- (a stream attribute for example) might require freezing E, but the
5206 -- freeze node must appear in the same declarative part as E itself.
5207 -- The two-pass elaboration mechanism in gigi guarantees that E will
5208 -- be frozen before the inner call is elaborated. We exclude constants
5209 -- from this test, because deferred constants may be frozen early, and
5210 -- must be diagnosed (e.g. in the case of a deferred constant being used
5211 -- in a default expression). If the enclosing subprogram comes from
5212 -- source, or is a generic instance, then the freeze point is the one
5213 -- mandated by the language, and we freeze the entity. A subprogram that
5214 -- is a child unit body that acts as a spec does not have a spec that
5215 -- comes from source, but can only come from source.
5220 then
5221 declare
5224 begin
5231 then
5233 else
5243 -- Similarly, an inlined instance body may make reference to global
5244 -- entities, but these references cannot be the proper freezing point
5245 -- for them, and in the absence of inlining freezing will take place in
5246 -- their own scope. Normally instance bodies are analyzed after the
5247 -- enclosing compilation, and everything has been frozen at the proper
5248 -- place, but with front-end inlining an instance body is compiled
5249 -- before the end of the enclosing scope, and as a result out-of-order
5250 -- freezing must be prevented.
5252 elsif Front_End_Inlining
5253 and then In_Instance_Body
5255 then
5256 declare
5259 begin
5264 else
5276 -- Add checks to detect proper initialization of scalars that may appear
5277 -- as subprogram parameters.
5283 -- Deal with delayed aspect specifications. The analysis of the aspect
5284 -- is required to be delayed to the freeze point, thus we analyze the
5285 -- pragma or attribute definition clause in the tree at this point. We
5286 -- also analyze the aspect specification node at the freeze point when
5287 -- the aspect doesn't correspond to pragma/attribute definition clause.
5288 -- In addition, a derived type may have inherited aspects that were
5289 -- delayed in the parent, so these must also be captured now.
5293 then
5297 -- Here to freeze the entity
5301 -- Case of entity being frozen is other than a type
5305 -- If entity is exported or imported and does not have an external
5306 -- name, now is the time to provide the appropriate default name.
5307 -- Skip this if the entity is stubbed, since we don't need a name
5308 -- for any stubbed routine. For the case on intrinsics, if no
5309 -- external name is specified, then calls will be handled in
5310 -- Exp_Intr.Expand_Intrinsic_Call, and no name is needed. If an
5311 -- external name is provided, then Expand_Intrinsic_Call leaves
5312 -- calls in place for expansion by GIGI.
5318 then
5319 Set_Encoded_Interface_Name
5322 -- If entity is an atomic object appearing in a declaration and
5323 -- the expression is an aggregate, assign it to a temporary to
5324 -- ensure that the actual assignment is done atomically rather
5325 -- than component-wise (the assignment to the temp may be done
5326 -- component-wise, but that is harmless).
5333 then
5337 -- Subprogram case
5341 -- Check for needing to wrap imported subprogram
5345 -- Freeze all parameter types and the return type (RM 13.14(14)).
5346 -- However skip this for internal subprograms. This is also where
5347 -- any extra formal parameters are created since we now know
5348 -- whether the subprogram will use a foreign convention.
5350 -- In Ada 2012, freezing a subprogram does not always freeze the
5351 -- corresponding profile (see AI05-019). An attribute reference
5352 -- is not a freezing point of the profile. Flag Do_Freeze_Profile
5353 -- indicates whether the profile should be frozen now.
5354 -- Other constructs that should not freeze ???
5356 -- This processing doesn't apply to internal entities (see below)
5364 -- Must freeze its parent first if it is a derived subprogram
5370 -- We don't freeze internal subprograms, because we don't normally
5371 -- want addition of extra formals or mechanism setting to happen
5372 -- for those. However we do pass through predefined dispatching
5373 -- cases, since extra formals may be needed in some cases, such as
5374 -- for the stream 'Input function (build-in-place formals).
5378 then
5382 -- If warning on suspicious contracts then check for the case of
5383 -- a postcondition other than False for a No_Return subprogram.
5386 and then Warn_On_Suspicious_Contract
5388 then
5389 declare
5393 begin
5396 Name_Post,
5397 Name_Postcondition,
5398 Name_Refined_Post)
5399 then
5400 Exp :=
5401 Expression
5406 then
5407 Error_Msg_NE
5418 -- Here for other than a subprogram or type
5420 else
5421 -- If entity has a type, and it is not a generic unit, then
5422 -- freeze it first (RM 13.14(10)).
5426 then
5429 -- For an object of an anonymous array type, aspects on the
5430 -- object declaration apply to the type itself. This is the
5431 -- case for Atomic_Components, Volatile_Components, and
5432 -- Independent_Components. In these cases analysis of the
5433 -- generated pragma will mark the anonymous types accordingly,
5434 -- and the object itself does not require a freeze node.
5440 then
5447 -- Special processing for objects created by object declaration
5453 -- Check that a constant which has a pragma Volatile[_Components]
5454 -- or Atomic[_Components] also has a pragma Import (RM C.6(13)).
5456 -- Note: Atomic[_Components] also sets Volatile[_Components]
5462 then
5463 -- Make sure we actually have a pragma, and have not merely
5464 -- inherited the indication from elsewhere (e.g. an address
5465 -- clause, which is not good enough in RM terms).
5468 or else
5470 then
5471 Error_Msg_N
5476 or else
5478 then
5479 Error_Msg_N
5485 -- Static objects require special handling
5489 then
5493 -- Remaining step is to layout objects
5497 then
5501 -- For an object that does not have delayed freezing, and whose
5502 -- initialization actions have been captured in a compound
5503 -- statement, move them back now directly within the enclosing
5504 -- statement sequence.
5508 then
5512 -- Do not generate a freeze node for a generic unit
5520 -- Case of a type or subtype being frozen
5522 else
5523 -- Verify several SPARK legality rules related to Ghost types now
5524 -- that the type is frozen.
5528 -- We used to check here that a full type must have preelaborable
5529 -- initialization if it completes a private type specified with
5530 -- pragma Preelaborable_Initialization, but that missed cases where
5531 -- the types occur within a generic package, since the freezing
5532 -- that occurs within a containing scope generally skips traversal
5533 -- of a generic unit's declarations (those will be frozen within
5534 -- instances). This check was moved to Analyze_Package_Specification.
5536 -- The type may be defined in a generic unit. This can occur when
5537 -- freezing a generic function that returns the type (which is
5538 -- defined in a parent unit). It is clearly meaningless to freeze
5539 -- this type. However, if it is a subtype, its size may be determi-
5540 -- nable and used in subsequent checks, so might as well try to
5541 -- compute it.
5543 -- In Ada 2012, Freeze_Entities is also used in the front end to
5544 -- trigger the analysis of aspect expressions, so in this case we
5545 -- want to continue the freezing process.
5547 -- Is_Generic_Unit (Scope (E)) is dubious here, do we want instead
5548 -- In_Generic_Scope (E)???
5552 and then
5555 then
5561 -- Check for error of Type_Invariant'Class applied to an untagged
5562 -- type (check delayed to freeze time when full type is available).
5564 declare
5566 begin
5570 then
5571 Error_Msg_NE
5573 Error_Msg_N
5578 -- Deal with special cases of freezing for subtype
5582 -- Before we do anything else, a specific test for the case of a
5583 -- size given for an array where the array would need to be packed
5584 -- in order for the size to be honored, but is not. This is the
5585 -- case where implicit packing may apply. The reason we do this so
5586 -- early is that, if we have implicit packing, the layout of the
5587 -- base type is affected, so we must do this before we freeze the
5588 -- base type.
5590 -- We could do this processing only if implicit packing is enabled
5591 -- since in all other cases, the error would be caught by the back
5592 -- end. However, we choose to do the check even if we do not have
5593 -- implicit packing enabled, since this allows us to give a more
5594 -- useful error message (advising use of pragma Implicit_Packing
5595 -- or pragma Pack).
5598 declare
5610 -- Number of elements in array
5612 begin
5613 -- Check enabling conditions. These are straightforward
5614 -- except for the test for a limited composite type. This
5615 -- eliminates the rare case of a array of limited components
5616 -- where there are issues of whether or not we can go ahead
5617 -- and pack the array (since we can't freely pack and unpack
5618 -- arrays if they are limited).
5620 -- Note that we check the root type explicitly because the
5621 -- whole point is we are doing this test before we have had
5622 -- a chance to freeze the base type (and it is that freeze
5623 -- action that causes stuff to be inherited).
5625 -- The conditions on the size are identical to those used in
5626 -- Freeze_Array_Type to set the Is_Packed flag.
5644 then
5645 -- Compute number of elements in array
5652 and then
5654 then
5662 else
5669 -- What we are looking for here is the situation where
5670 -- the RM_Size given would be exactly right if there was
5671 -- a pragma Pack, resulting in the component size being
5672 -- the RM_Size of the component type.
5676 -- For implicit packing mode, just set the component
5677 -- size and Freeze_Array_Type will do the rest.
5682 -- Otherwise give an error message
5684 else
5685 Error_Msg_NE
5687 Error_Msg_N -- CODEFIX
5698 -- If ancestor subtype present, freeze that first. Note that this
5699 -- will also get the base type frozen. Need RM reference ???
5706 -- No ancestor subtype present
5708 else
5709 -- See if we have a nearest ancestor that has a predicate.
5710 -- That catches the case of derived type with a predicate.
5711 -- Need RM reference here ???
5719 -- Freeze base type before freezing the entity (RM 13.14(15))
5726 -- A subtype inherits all the type-related representation aspects
5727 -- from its parents (RM 13.1(8)).
5731 -- For a derived type, freeze its parent type first (RM 13.14(15))
5737 -- A derived type inherits each type-related representation aspect
5738 -- of its parent type that was directly specified before the
5739 -- declaration of the derived type (RM 13.1(15)).
5744 -- Check for incompatible size and alignment for record type
5746 if Warn_On_Size_Alignment
5750 -- If explicit Object_Size clause given assume that the programmer
5751 -- knows what he is doing, and expects the compiler behavior.
5755 -- Check for size not a multiple of alignment
5758 then
5759 declare
5765 begin
5768 -- Give a warning
5772 Error_Msg_NE
5779 else
5781 Error_Msg_NE
5795 -- Array type
5800 -- For a class-wide type, the corresponding specific type is
5801 -- frozen as well (RM 13.14(15))
5806 -- If the base type of the class-wide type is still incomplete,
5807 -- the class-wide remains unfrozen as well. This is legal when
5808 -- E is the formal of a primitive operation of some other type
5809 -- which is being frozen.
5816 -- The equivalent type associated with a class-wide subtype needs
5817 -- to be frozen to ensure that its layout is done.
5821 then
5825 -- Generate an itype reference for a library-level class-wide type
5826 -- at the freeze point. Otherwise the first explicit reference to
5827 -- the type may appear in an inner scope which will be rejected by
5828 -- the back-end.
5832 then
5833 declare
5836 begin
5839 -- From a gigi point of view, a class-wide subtype derives
5840 -- from its record equivalent type. As a result, the itype
5841 -- reference must appear after the freeze node of the
5842 -- equivalent type or gigi will reject the reference.
5846 then
5848 else
5854 -- For a record type or record subtype, freeze all component types
5855 -- (RM 13.14(15)). We test for E_Record_(sub)Type here, rather than
5856 -- using Is_Record_Type, because we don't want to attempt the freeze
5857 -- for the case of a private type with record extension (we will do
5858 -- that later when the full type is frozen).
5865 -- Report a warning if a discriminated record base type has a
5866 -- convention with language C or C++ applied to it. This check is
5867 -- done even within generic scopes (but not in instantiations),
5868 -- which is why we don't do it as part of Freeze_Record_Type.
5872 -- For a concurrent type, freeze corresponding record type. This does
5873 -- not correspond to any specific rule in the RM, but the record type
5874 -- is essentially part of the concurrent type. Also freeze all local
5875 -- entities. This includes record types created for entry parameter
5876 -- blocks and whatever local entities may appear in the private part.
5890 -- The guard on the presence of the Etype seems to be needed
5891 -- for some CodePeer (-gnatcC) cases, but not clear why???
5896 then
5907 -- Private types are required to point to the same freeze node as
5908 -- their corresponding full views. The freeze node itself has to
5909 -- point to the partial view of the entity (because from the partial
5910 -- view, we can retrieve the full view, but not the reverse).
5911 -- However, in order to freeze correctly, we need to freeze the full
5912 -- view. If we are freezing at the end of a scope (or within the
5913 -- scope) of the private type, the partial and full views will have
5914 -- been swapped, the full view appears first in the entity chain and
5915 -- the swapping mechanism ensures that the pointers are properly set
5916 -- (on scope exit).
5918 -- If we encounter the partial view before the full view (e.g. when
5919 -- freezing from another scope), we freeze the full view, and then
5920 -- set the pointers appropriately since we cannot rely on swapping to
5921 -- fix things up (subtypes in an outer scope might not get swapped).
5923 -- If the full view is itself private, the above requirements apply
5924 -- to the underlying full view instead of the full view. But there is
5925 -- no swapping mechanism for the underlying full view so we need to
5926 -- set the pointers appropriately in both cases.
5930 then
5931 -- The construction of the dispatch table associated with library
5932 -- level tagged types forces freezing of all the primitives of the
5933 -- type, which may cause premature freezing of the partial view.
5934 -- For example:
5936 -- package Pkg is
5937 -- type T is tagged private;
5938 -- type DT is new T with private;
5939 -- procedure Prim (X : in out T; Y : in out DT'Class);
5940 -- private
5941 -- type T is tagged null record;
5942 -- Obj : T;
5943 -- type DT is new T with null record;
5944 -- end;
5946 -- In this case the type will be frozen later by the usual
5947 -- mechanism: an object declaration, an instantiation, or the
5948 -- end of a declarative part.
5952 then
5956 -- Case of full view present
5960 -- If full view has already been frozen, then no further
5961 -- processing is required
5967 -- Otherwise freeze full view and patch the pointers so that
5968 -- the freeze node will elaborate both views in the back end.
5969 -- However, if full view is itself private, freeze underlying
5970 -- full view instead and patch the pointers so that the freeze
5971 -- node will elaborate the three views in the back end.
5973 else
5974 declare
5977 begin
5980 then
5988 then
5992 Inherit_Freeze_Node
5995 else
6005 Inherit_Freeze_Node
6008 else
6009 -- {Incomplete,Private}_Subtypes with Full_Views
6010 -- constrained by discriminants.
6021 -- AI-117 requires that the convention of a partial view be the
6022 -- same as the convention of the full view. Note that this is a
6023 -- recognized breach of privacy, but it's essential for logical
6024 -- consistency of representation, and the lack of a rule in
6025 -- RM95 was an oversight.
6032 -- Size information is copied from the full view to the
6033 -- incomplete or private view for consistency.
6035 -- We skip this is the full view is not a type. This is very
6036 -- strange of course, and can only happen as a result of
6037 -- certain illegalities, such as a premature attempt to derive
6038 -- from an incomplete type.
6047 -- Case of underlying full view present
6051 then
6056 -- Patch the pointers so that the freeze node will elaborate
6057 -- both views in the back end.
6063 Inherit_Freeze_Node
6066 else
6076 -- Case of no full view present. If entity is derived or subtype,
6077 -- it is safe to freeze, correctness depends on the frozen status
6078 -- of parent. Otherwise it is either premature usage, or a Taft
6079 -- amendment type, so diagnosis is at the point of use and the
6080 -- type might be frozen later.
6085 else
6091 -- For access subprogram, freeze types of all formals, the return
6092 -- type was already frozen, since it is the Etype of the function.
6093 -- Formal types can be tagged Taft amendment types, but otherwise
6094 -- they cannot be incomplete.
6101 then
6105 -- AI05-151: Incomplete types are allowed in access to
6106 -- subprogram specifications.
6109 Error_Msg_NE
6120 -- For access to a protected subprogram, freeze the equivalent type
6121 -- (however this is not set if we are not generating code or if this
6122 -- is an anonymous type used just for resolution).
6130 -- Generic types are never seen by the back-end, and are also not
6131 -- processed by the expander (since the expander is turned off for
6132 -- generic processing), so we never need freeze nodes for them.
6138 -- Some special processing for non-generic types to complete
6139 -- representation details not known till the freeze point.
6144 -- Some error checks required for ordinary fixed-point type. Defer
6145 -- these till the freeze-point since we need the small and range
6146 -- values. We only do these checks for base types
6151 Error_Msg_N
6156 Error_Msg_N
6162 Error_Msg_N
6168 Error_Msg_N
6180 and then Warn_On_Suspicious_Modulus_Value
6181 then
6185 -- The pool applies to named and anonymous access types, but not
6186 -- to subprogram and to internal types generated for 'Access
6187 -- references.
6192 then
6193 -- If a pragma Default_Storage_Pool applies, and this type has no
6194 -- Storage_Pool or Storage_Size clause (which must have occurred
6195 -- before the freezing point), then use the default. This applies
6196 -- only to base types.
6198 -- None of this applies to access to subprograms, for which there
6199 -- are clearly no pools.
6205 then
6206 -- Case of pragma Default_Storage_Pool (null)
6211 -- Case of pragma Default_Storage_Pool (storage_pool_NAME)
6213 else
6218 -- Check restriction for standard storage pool
6224 -- Deal with error message for pure access type. This is not an
6225 -- error in Ada 2005 if there is no pool (see AI-366).
6231 then
6235 Error_Msg_N
6239 Error_Msg_N
6242 else
6243 Error_Msg_N
6250 -- Case of composite types
6254 -- AI-117 requires that all new primitives of a tagged type must
6255 -- inherit the convention of the full view of the type. Inherited
6256 -- and overriding operations are defined to inherit the convention
6257 -- of their parent or overridden subprogram (also specified in
6258 -- AI-117), which will have occurred earlier (in Derive_Subprogram
6259 -- and New_Overloaded_Entity). Here we set the convention of
6260 -- primitives that are still convention Ada, which will ensure
6261 -- that any new primitives inherit the type's convention. Class-
6262 -- wide types can have a foreign convention inherited from their
6263 -- specific type, but are excluded from this since they don't have
6264 -- any associated primitives.
6269 then
6270 declare
6274 begin
6286 -- If the type is a simple storage pool type, then this is where
6287 -- we attempt to locate and validate its Allocate, Deallocate, and
6288 -- Storage_Size operations (the first is required, and the latter
6289 -- two are optional). We also verify that the full type for a
6290 -- private type is allowed to be a simple storage pool type.
6294 then
6295 -- If the type is marked Has_Private_Declaration, then this is
6296 -- a full type for a private type that was specified with the
6297 -- pragma Simple_Storage_Pool_Type, and here we ensure that the
6298 -- pragma is allowed for the full type (for example, it can't
6299 -- be an array type, or a nonlimited record type).
6304 then
6306 Error_Msg_N
6317 procedure Validate_Simple_Pool_Op_Formal
6324 -- Validate one formal Pool_Op_Formal of the candidate pool
6325 -- operation Pool_Op. The formal must be of Expected_Type
6326 -- and have mode Expected_Mode. OK_Formal will be set to
6327 -- False if the formal doesn't match. If OK_Formal is False
6328 -- on entry, then the formal will effectively be ignored
6329 -- (because validation of the pool op has already failed).
6330 -- Upon return, Pool_Op_Formal will be updated to the next
6331 -- formal, if any.
6333 procedure Validate_Simple_Pool_Operation
6335 -- Search for and validate a simple pool operation with the
6336 -- name Op_Name. If the name is Allocate, then there must be
6337 -- exactly one such primitive operation for the simple pool
6338 -- type. If the name is Deallocate or Storage_Size, then
6339 -- there can be at most one such primitive operation. The
6340 -- profile of the located primitive must conform to what
6341 -- is expected for each operation.
6343 ------------------------------------
6344 -- Validate_Simple_Pool_Op_Formal --
6345 ------------------------------------
6347 procedure Validate_Simple_Pool_Op_Formal
6354 is
6355 begin
6356 -- If OK_Formal is False on entry, then simply ignore
6357 -- the formal, because an earlier formal has already
6358 -- been flagged.
6363 -- If no formal is passed in, then issue an error for a
6364 -- missing formal.
6367 Error_Msg_NE
6377 -- If the pool type was expected for this formal, then
6378 -- this will not be considered a candidate operation
6379 -- for the simple pool, so we unset OK_Formal so that
6380 -- the op and any later formals will be ignored.
6387 else
6388 Error_Msg_NE
6395 -- Issue error if formal's mode is not the expected one
6398 Error_Msg_N
6400 Pool_Op_Formal);
6403 -- Advance to the next formal
6408 ------------------------------------
6409 -- Validate_Simple_Pool_Operation --
6410 ------------------------------------
6412 procedure Validate_Simple_Pool_Operation
6414 is
6420 begin
6421 pragma Assert
6423 Name_Deallocate,
6424 Name_Storage_Size));
6428 -- For each homonym declared immediately in the scope
6429 -- of the simple storage pool type, determine whether
6430 -- the homonym is an operation of the pool type, and,
6431 -- if so, check that its profile is as expected for
6432 -- a simple pool operation of that name.
6438 then
6443 -- The first parameter must be of the pool type
6444 -- in order for the operation to qualify.
6447 Validate_Simple_Pool_Op_Formal
6450 else
6451 Validate_Simple_Pool_Op_Formal
6456 -- If another operation with this name has already
6457 -- been located for the type, then flag an error,
6458 -- since we only allow the type to have a single
6459 -- such primitive.
6462 Error_Msg_NE
6467 -- In the case of Allocate and Deallocate, a formal
6468 -- of type System.Address is required.
6471 Validate_Simple_Pool_Op_Formal
6476 Validate_Simple_Pool_Op_Formal
6481 -- In the case of Allocate and Deallocate, formals
6482 -- of type Storage_Count are required as the third
6483 -- and fourth parameters.
6486 Validate_Simple_Pool_Op_Formal
6489 Validate_Simple_Pool_Op_Formal
6494 -- If no mismatched formals have been found (Is_OK)
6495 -- and no excess formals are present, then this
6496 -- operation has been validated, so record it.
6506 -- There must be a valid Allocate operation for the type,
6507 -- so issue an error if none was found.
6511 then
6517 -- Simple pool operations can't be abstract
6520 Error_Msg_N
6525 -- The Storage_Size operation must be a function with
6526 -- Storage_Count as its result type.
6530 Error_Msg_N
6534 Error_Msg_NE
6539 -- Allocate and Deallocate must be procedures
6542 Error_Msg_N
6548 -- Start of processing for Validate_Simple_Pool_Ops
6550 begin
6558 -- Now that all types from which E may depend are frozen, see if the
6559 -- size is known at compile time, if it must be unsigned, or if
6560 -- strict alignment is required
6569 -- Do not allow a size clause for a type which does not have a size
6570 -- that is known at compile time
6574 then
6575 -- Suppress this message if errors posted on E, even if we are
6576 -- in all errors mode, since this is often a junk message
6579 Error_Msg_N
6585 -- Now we set/verify the representation information, in particular
6586 -- the size and alignment values. This processing is not required for
6587 -- generic types, since generic types do not play any part in code
6588 -- generation, and so the size and alignment values for such types
6589 -- are irrelevant. Ditto for types declared within a generic unit,
6590 -- which may have components that depend on generic parameters, and
6591 -- that will be recreated in an instance.
6596 -- Otherwise we call the layout procedure
6598 else
6602 -- If this is an access to subprogram whose designated type is itself
6603 -- a subprogram type, the return type of this anonymous subprogram
6604 -- type must be decorated as well.
6608 then
6612 -- If the type has a Defaut_Value/Default_Component_Value aspect,
6613 -- this is where we analye the expression (after the type is frozen,
6614 -- since in the case of Default_Value, we are analyzing with the
6615 -- type itself, and we treat Default_Component_Value similarly for
6616 -- the sake of uniformity).
6619 declare
6624 begin
6629 else
6640 Flag_Non_Static_Expr
6647 -- End of freeze processing for type entities
6650 -- Here is where we logically freeze the current entity. If it has a
6651 -- freeze node, then this is the point at which the freeze node is
6652 -- linked into the result list.
6656 -- If a freeze node is already allocated, use it, otherwise allocate
6657 -- a new one. The preallocation happens in the case of anonymous base
6658 -- types, where we preallocate so that we can set First_Subtype_Link.
6659 -- Note that we reset the Sloc to the current freeze location.
6665 else
6676 -- A final pass over record types with discriminants. If the type
6677 -- has an incomplete declaration, there may be constrained access
6678 -- subtypes declared elsewhere, which do not depend on the discrimi-
6679 -- nants of the type, and which are used as component types (i.e.
6680 -- the full view is a recursive type). The designated types of these
6681 -- subtypes can only be elaborated after the type itself, and they
6682 -- need an itype reference.
6685 declare
6690 begin
6700 then
6712 -- When a type is frozen, the first subtype of the type is frozen as
6713 -- well (RM 13.14(15)). This has to be done after freezing the type,
6714 -- since obviously the first subtype depends on its own base type.
6719 -- If we just froze a tagged non-class wide record, then freeze the
6720 -- corresponding class-wide type. This must be done after the tagged
6721 -- type itself is frozen, because the class-wide type refers to the
6722 -- tagged type which generates the class.
6727 then
6734 -- Special handling for subprograms
6738 -- If subprogram has address clause then reset Is_Public flag, since
6739 -- we do not want the backend to generate external references.
6743 then
6754 -----------------------------
6755 -- Freeze_Enumeration_Type --
6756 -----------------------------
6759 begin
6760 -- By default, if no size clause is present, an enumeration type with
6761 -- Convention C is assumed to interface to a C enum, and has integer
6762 -- size. This applies to types. For subtypes, verify that its base
6763 -- type has no size clause either. Treat other foreign conventions
6764 -- in the same way, and also make sure alignment is set right.
6771 -- Don't do this if Short_Enums on target
6773 and then not Target_Short_Enums
6774 then
6778 -- Normal Ada case or size clause present or not Long_C_Enums on target
6780 else
6781 -- If the enumeration type interfaces to C, and it has a size clause
6782 -- that specifies less than int size, it warrants a warning. The
6783 -- user may intend the C type to be an enum or a char, so this is
6784 -- not by itself an error that the Ada compiler can detect, but it
6785 -- it is a worth a heads-up. For Boolean and Character types we
6786 -- assume that the programmer has the proper C type in mind.
6794 -- Don't do this if Short_Enums on target
6796 and then not Target_Short_Enums
6797 then
6798 Error_Msg_N
6806 -----------------------
6807 -- Freeze_Expression --
6808 -----------------------
6819 -- This flag is set true if the entity must be frozen outside the
6820 -- current subprogram. This happens in the case of expander generated
6821 -- subprograms (_Init_Proc, _Input, _Output, _Read, _Write) which do
6822 -- not freeze all entities like other bodies, but which nevertheless
6823 -- may reference entities that have to be frozen before the body and
6824 -- obviously cannot be frozen inside the body.
6827 -- If the expression is an array aggregate, the type of the component
6828 -- expressions is also frozen. If the component type is an access type
6829 -- and the expressions include allocators, the designed type is frozen
6830 -- as well.
6833 -- Given an N_Handled_Sequence_Of_Statements node N, determines whether
6834 -- it is the handled statement sequence of an expander-generated
6835 -- subprogram (init proc, stream subprogram, or renaming as body).
6836 -- If so, this is not a freezing context.
6838 -----------------------------------------
6839 -- Find_Aggregate_Component_Desig_Type --
6840 -----------------------------------------
6846 begin
6872 ----------------------
6873 -- In_Expanded_Body --
6874 ----------------------
6880 begin
6883 else
6890 else
6893 -- The following are expander-created bodies, or bodies that
6894 -- are not freeze points.
6903 N_Subprogram_Renaming_Declaration,
6904 N_Expression_Function))
6905 then
6907 else
6913 -- Start of processing for Freeze_Expression
6915 begin
6916 -- Immediate return if freezing is inhibited. This flag is set by the
6917 -- analyzer to stop freezing on generated expressions that would cause
6918 -- freezing if they were in the source program, but which are not
6919 -- supposed to freeze, since they are created.
6925 -- If expression is non-static, then it does not freeze in a default
6926 -- expression, see section "Handling of Default Expressions" in the
6927 -- spec of package Sem for further details. Note that we have to make
6928 -- sure that we actually have a real expression (if we have a subtype
6929 -- indication, we can't test Is_OK_Static_Expression). However, we
6930 -- exclude the case of the prefix of an attribute of a static scalar
6931 -- subtype from this early return, because static subtype attributes
6932 -- should always cause freezing, even in default expressions, but
6933 -- the attribute may not have been marked as static yet (because in
6934 -- Resolve_Attribute, the call to Eval_Attribute follows the call of
6935 -- Freeze_Expression on the prefix).
6937 if In_Spec_Exp
6944 then
6948 -- Freeze type of expression if not frozen already
6956 -- Base type may be an derived numeric type that is frozen at
6957 -- the point of declaration, but first_subtype is still unfrozen.
6964 -- For entity name, freeze entity if not frozen already. A special
6965 -- exception occurs for an identifier that did not come from source.
6966 -- We don't let such identifiers freeze a non-internal entity, i.e.
6967 -- an entity that did come from source, since such an identifier was
6968 -- generated by the expander, and cannot have any semantic effect on
6969 -- the freezing semantics. For example, this stops the parameter of
6970 -- an initialization procedure from freezing the variable.
6977 then
6984 else
6988 -- For an allocator freeze designated type if not frozen already
6990 -- For an aggregate whose component type is an access type, freeze the
6991 -- designated type now, so that its freeze does not appear within the
6992 -- loop that might be created in the expansion of the aggregate. If the
6993 -- designated type is a private type without full view, the expression
6994 -- cannot contain an allocator, so the type is not frozen.
6996 -- For a function, we freeze the entity when the subprogram declaration
6997 -- is frozen, but a function call may appear in an initialization proc.
6998 -- before the declaration is frozen. We need to generate the extra
6999 -- formals, if any, to ensure that the expansion of the call includes
7000 -- the proper actuals. This only applies to Ada subprograms, not to
7001 -- imported ones.
7012 then
7014 -- Check whether aggregate includes allocators.
7019 when N_Indexed_Component
7020 | N_Selected_Component
7021 | N_Slice
7022 =>
7032 then
7043 then
7047 -- All done if nothing needs freezing
7052 then
7056 -- Examine the enclosing context by climbing the parent chain. The
7057 -- traversal serves two purposes - to detect scenarios where freezeing
7058 -- is not needed and to find the proper insertion point for the freeze
7059 -- nodes. Although somewhat similar to Insert_Actions, this traversal
7060 -- is freezing semantics-sensitive. Inserting freeze nodes blindly in
7061 -- the tree may result in types being frozen too early.
7064 loop
7067 -- If we don't have a parent, then we are not in a well-formed tree.
7068 -- This is an unusual case, but there are some legitimate situations
7069 -- in which this occurs, notably when the expressions in the range of
7070 -- a type declaration are resolved. We simply ignore the freeze
7071 -- request in this case. Is this right ???
7077 -- See if we have got to an appropriate point in the tree
7081 -- A special test for the exception of (RM 13.14(8)) for the case
7082 -- of per-object expressions (RM 3.8(18)) occurring in component
7083 -- definition or a discrete subtype definition. Note that we test
7084 -- for a component declaration which includes both cases we are
7085 -- interested in, and furthermore the tree does not have explicit
7086 -- nodes for either of these two constructs.
7090 -- The case we want to test for here is an identifier that is
7091 -- a per-object expression, this is either a discriminant that
7092 -- appears in a context other than the component declaration
7093 -- or it is a reference to the type of the enclosing construct.
7095 -- For either of these cases, we skip the freezing
7097 if not In_Spec_Expression
7100 then
7101 -- We recognize the discriminant case by just looking for
7102 -- a reference to a discriminant. It can only be one for
7103 -- the enclosing construct. Skip freezing in this case.
7108 -- For the case of a reference to the enclosing record,
7109 -- (or task or protected type), we look for a type that
7110 -- matches the current scope.
7117 -- If we have an enumeration literal that appears as the choice in
7118 -- the aggregate of an enumeration representation clause, then
7119 -- freezing does not occur (RM 13.14(10)).
7123 -- The case we are looking for is an enumeration literal
7127 then
7128 -- If enumeration literal appears directly as the choice,
7129 -- do not freeze (this is the normal non-overloaded case)
7133 then
7136 -- If enumeration literal appears as the name of function
7137 -- which is the choice, then also do not freeze. This
7138 -- happens in the overloaded literal case, where the
7139 -- enumeration literal is temporarily changed to a function
7140 -- call for overloading analysis purposes.
7143 and then
7145 and then
7147 then
7152 -- Normally if the parent is a handled sequence of statements,
7153 -- then the current node must be a statement, and that is an
7154 -- appropriate place to insert a freeze node.
7158 -- An exception occurs when the sequence of statements is for
7159 -- an expander generated body that did not do the usual freeze
7160 -- all operation. In this case we usually want to freeze
7161 -- outside this body, not inside it, and we skip past the
7162 -- subprogram body that we are inside.
7165 declare
7169 begin
7170 -- Freeze the entity only when it is declared inside the
7171 -- body of the expander generated procedure. This case
7172 -- is recognized by the scope of the entity or its type,
7173 -- which is either the spec for some enclosing body, or
7174 -- (in the case of init_procs, for which there are no
7175 -- separate specs) the current scope.
7181 or else
7183 then
7189 then
7194 -- An expression function may act as a completion of
7195 -- a function declaration. As such, it can reference
7196 -- entities declared between the two views:
7198 -- Hidden []; -- 1
7199 -- function F return ...;
7200 -- private
7201 -- function Hidden return ...;
7202 -- function F return ... is (Hidden); -- 2
7204 -- Refering to the example above, freezing the expression
7205 -- of F (2) would place Hidden's freeze node (1) in the
7206 -- wrong place. Avoid explicit freezing and let the usual
7207 -- scenarios do the job - for example, reaching the end
7208 -- of the private declarations, or a call to F.
7211 N_Expression_Function
7212 then
7215 -- Freeze outside the body
7217 else
7223 -- Here if normal case where we are in handled statement
7224 -- sequence and want to do the insertion right there.
7226 else
7230 -- If parent is a body or a spec or a block, then the current node
7231 -- is a statement or declaration and we can insert the freeze node
7232 -- before it.
7234 when N_Block_Statement
7235 | N_Entry_Body
7236 | N_Package_Body
7237 | N_Package_Specification
7238 | N_Protected_Body
7239 | N_Subprogram_Body
7240 | N_Task_Body
7241 =>
7244 -- The expander is allowed to define types in any statements list,
7245 -- so any of the following parent nodes also mark a freezing point
7246 -- if the actual node is in a list of statements or declarations.
7248 when N_Abortable_Part
7249 | N_Accept_Alternative
7250 | N_And_Then
7251 | N_Case_Statement_Alternative
7252 | N_Compilation_Unit_Aux
7253 | N_Conditional_Entry_Call
7254 | N_Delay_Alternative
7255 | N_Elsif_Part
7256 | N_Entry_Call_Alternative
7257 | N_Exception_Handler
7258 | N_Extended_Return_Statement
7259 | N_Freeze_Entity
7260 | N_If_Statement
7261 | N_Or_Else
7262 | N_Selective_Accept
7263 | N_Triggering_Alternative
7264 =>
7267 -- Freeze nodes produced by an expression coming from the Actions
7268 -- list of a N_Expression_With_Actions node must remain within the
7269 -- Actions list. Inserting the freeze nodes further up the tree
7270 -- may lead to use before declaration issues in the case of array
7271 -- types.
7276 then
7280 -- Note: N_Loop_Statement is a special case. A type that appears
7281 -- in the source can never be frozen in a loop (this occurs only
7282 -- because of a loop expanded by the expander), so we keep on
7283 -- going. Otherwise we terminate the search. Same is true of any
7284 -- entity which comes from source. (if they have predefined type,
7285 -- that type does not appear to come from source, but the entity
7286 -- should not be frozen here).
7292 -- For all other cases, keep looking at parents
7298 -- We fall through the case if we did not yet find the proper
7299 -- place in the free for inserting the freeze node, so climb.
7304 -- If the expression appears in a record or an initialization procedure,
7305 -- the freeze nodes are collected and attached to the current scope, to
7306 -- be inserted and analyzed on exit from the scope, to insure that
7307 -- generated entities appear in the correct scope. If the expression is
7308 -- a default for a discriminant specification, the scope is still void.
7309 -- The expression can also appear in the discriminant part of a private
7310 -- or concurrent type.
7312 -- If the expression appears in a constrained subcomponent of an
7313 -- enclosing record declaration, the freeze nodes must be attached to
7314 -- the outer record type so they can eventually be placed in the
7315 -- enclosing declaration list.
7317 -- The other case requiring this special handling is if we are in a
7318 -- default expression, since in that case we are about to freeze a
7319 -- static type, and the freeze scope needs to be the outer scope, not
7320 -- the scope of the subprogram with the default parameter.
7322 -- For default expressions and other spec expressions in generic units,
7323 -- the Move_Freeze_Nodes mechanism (see sem_ch12.adb) takes care of
7324 -- placing them at the proper place, after the generic unit.
7327 or else Freeze_Outside
7332 then
7333 declare
7338 begin
7351 -- The current scope may be that of a constrained component of
7352 -- an enclosing record declaration, or of a loop of an enclosing
7353 -- quantified expression, which is above the current scope in the
7354 -- scope stack. Indeed in the context of a quantified expression,
7355 -- a scope is created and pushed above the current scope in order
7356 -- to emulate the loop-like behavior of the quantified expression.
7357 -- If the expression is within a top-level pragma, as for a pre-
7358 -- condition on a library-level subprogram, nothing to do.
7363 N_Quantified_Expression)
7364 then
7371 Freeze_Nodes;
7372 else
7382 -- Now we have the right place to do the freezing. First, a special
7383 -- adjustment, if we are in spec-expression analysis mode, these freeze
7384 -- actions must not be thrown away (normally all inserted actions are
7385 -- thrown away in this mode. However, the freeze actions are from static
7386 -- expressions and one of the important reasons we are doing this
7387 -- special analysis is to get these freeze actions. Therefore we turn
7388 -- off the In_Spec_Expression mode to propagate these freeze actions.
7389 -- This also means they get properly analyzed and expanded.
7393 -- Freeze the designated type of an allocator (RM 13.14(13))
7399 -- Freeze type of expression (RM 13.14(10)). Note that we took care of
7400 -- the enumeration representation clause exception in the loop above.
7406 -- Freeze name if one is present (RM 13.14(11))
7412 -- Restore In_Spec_Expression flag
7417 -----------------------------
7418 -- Freeze_Fixed_Point_Type --
7419 -----------------------------
7421 -- Certain fixed-point types and subtypes, including implicit base types
7422 -- and declared first subtypes, have not yet set up a range. This is
7423 -- because the range cannot be set until the Small and Size values are
7424 -- known, and these are not known till the type is frozen.
7426 -- To signal this case, Scalar_Range contains an unanalyzed syntactic range
7427 -- whose bounds are unanalyzed real literals. This routine will recognize
7428 -- this case, and transform this range node into a properly typed range
7429 -- with properly analyzed and resolved values.
7446 -- Save original bounds (for shaving tests)
7449 -- Actual size chosen
7452 -- Returns size of type with given bounds. Also leaves these
7453 -- bounds set as the current bounds of the Typ.
7455 -----------
7456 -- Fsize --
7457 -----------
7460 begin
7466 -- Start of processing for Freeze_Fixed_Point_Type
7468 begin
7469 -- If Esize of a subtype has not previously been set, set it now
7476 else
7481 -- Immediate return if the range is already analyzed. This means that
7482 -- the range is already set, and does not need to be computed by this
7483 -- routine.
7489 -- Immediate return if either of the bounds raises Constraint_Error
7493 then
7503 -- Ordinary fixed-point case
7507 -- For the ordinary fixed-point case, we are allowed to fudge the
7508 -- end-points up or down by small. Generally we prefer to fudge up,
7509 -- i.e. widen the bounds for non-model numbers so that the end points
7510 -- are included. However there are cases in which this cannot be
7511 -- done, and indeed cases in which we may need to narrow the bounds.
7512 -- The following circuit makes the decision.
7514 -- Note: our terminology here is that Incl_EP means that the bounds
7515 -- are widened by Small if necessary to include the end points, and
7516 -- Excl_EP means that the bounds are narrowed by Small to exclude the
7517 -- end-points if this reduces the size.
7519 -- Note that in the Incl case, all we care about is including the
7520 -- end-points. In the Excl case, we want to narrow the bounds as
7521 -- much as permitted by the RM, to give the smallest possible size.
7538 begin
7539 -- First step. Base types are required to be symmetrical. Right
7540 -- now, the base type range is a copy of the first subtype range.
7541 -- This will be corrected before we are done, but right away we
7542 -- need to deal with the case where both bounds are non-negative.
7543 -- In this case, we set the low bound to the negative of the high
7544 -- bound, to make sure that the size is computed to include the
7545 -- required sign. Note that we do not need to worry about the
7546 -- case of both bounds negative, because the sign will be dealt
7547 -- with anyway. Furthermore we can't just go making such a bound
7548 -- symmetrical, since in a twos-complement system, there is an
7549 -- extra negative value which could not be accommodated on the
7550 -- positive side.
7555 then
7560 -- Compute the fudged bounds. If the number is a model number,
7561 -- then we do nothing to include it, but we are allowed to backoff
7562 -- to the next adjacent model number when we exclude it. If it is
7563 -- not a model number then we straddle the two values with the
7564 -- model numbers on either side.
7570 else
7574 -- The low value excluding the end point is Small greater, but
7575 -- we do not do this exclusion if the low value is positive,
7576 -- since it can't help the size and could actually hurt by
7577 -- crossing the high bound.
7582 -- If the value went from negative to zero, then we have the
7583 -- case where Loval_Incl_EP is the model number just below
7584 -- zero, so we want to stick to the negative value for the
7585 -- base type to maintain the condition that the size will
7586 -- include signed values.
7590 then
7594 else
7598 -- Similar processing for upper bound and high value
7604 else
7610 else
7614 -- One further adjustment is needed. In the case of subtypes, we
7615 -- cannot go outside the range of the base type, or we get
7616 -- peculiarities, and the base type range is already set. This
7617 -- only applies to the Incl values, since clearly the Excl values
7618 -- are already as restricted as they are allowed to be.
7625 -- Get size including and excluding end points
7630 -- No need to exclude end-points if it does not reduce size
7640 -- Now we set the actual size to be used. We want to use the
7641 -- bounds fudged up to include the end-points but only if this
7642 -- can be done without violating a specifically given size
7643 -- size clause or causing an unacceptable increase in size.
7645 -- Case of size clause given
7649 -- Use the inclusive size only if it is consistent with
7650 -- the explicitly specified size.
7657 -- If the inclusive size is too large, we try excluding
7658 -- the end-points (will be caught later if does not work).
7660 else
7666 -- Case of size clause not given
7668 else
7669 -- If we have a base type whose corresponding first subtype
7670 -- has an explicit size that is large enough to include our
7671 -- end-points, then do so. There is no point in working hard
7672 -- to get a base type whose size is smaller than the specified
7673 -- size of the first subtype.
7679 then
7684 -- If excluding the end-points makes the size smaller and
7685 -- results in a size of 8,16,32,64, then we take the smaller
7686 -- size. For the 64 case, this is compulsory. For the other
7687 -- cases, it seems reasonable. We like to include end points
7688 -- if we can, but not at the expense of moving to the next
7689 -- natural boundary of size.
7693 then
7698 -- Otherwise we can definitely include the end points
7700 else
7706 -- One pathological case: normally we never fudge a low bound
7707 -- down, since it would seem to increase the size (if it has
7708 -- any effect), but for ranges containing single value, or no
7709 -- values, the high bound can be small too large. Consider:
7711 -- type t is delta 2.0**(-14)
7712 -- range 131072.0 .. 0;
7714 -- That lower bound is *just* outside the range of 32 bits, and
7715 -- does need fudging down in this case. Note that the bounds
7716 -- will always have crossed here, since the high bound will be
7717 -- fudged down if necessary, as in the case of:
7719 -- type t is delta 2.0**(-14)
7720 -- range 131072.0 .. 131072.0;
7722 -- So we detect the situation by looking for crossed bounds,
7723 -- and if the bounds are crossed, and the low bound is greater
7724 -- than zero, we will always back it off by small, since this
7725 -- is completely harmless.
7732 -- And of course, we need to do exactly the same parallel
7733 -- fudge for flat ranges in the negative region.
7746 -- For the decimal case, none of this fudging is required, since there
7747 -- are no end-point problems in the decimal case (the end-points are
7748 -- always included).
7750 else
7754 -- At this stage, the actual size has been calculated and the proper
7755 -- required bounds are stored in the low and high bounds.
7759 Error_Msg_N
7761 Typ);
7765 -- Check size against explicit given size
7771 Error_Msg_NE
7775 else
7779 -- Increase size to next natural boundary if no size clause given
7781 else
7788 else
7796 -- If we have a base type, then expand the bounds so that they extend to
7797 -- the full width of the allocated size in bits, to avoid junk range
7798 -- checks on intermediate computations.
7805 -- Final step is to reanalyze the bounds using the proper type
7806 -- and set the Corresponding_Integer_Value fields of the literals.
7812 -- Resolve with universal fixed if the base type, and the base type if
7813 -- it is a subtype. Note we can't resolve the base type with itself,
7814 -- that would be a reference before definition.
7818 else
7822 -- Set corresponding integer value for bound
7824 Set_Corresponding_Integer_Value
7827 -- Similar processing for high bound
7835 else
7839 Set_Corresponding_Integer_Value
7842 -- Set type of range to correspond to bounds
7846 -- Set Esize to calculated size if not set already
7852 -- Set RM_Size if not already set. If already set, check value
7854 declare
7857 begin
7862 Error_Msg_NE
7867 else
7872 -- Check for shaving
7876 -- In SPARK mode the given bounds must be strictly representable
7880 Error_Msg_NE
7886 Error_Msg_NE
7891 else
7893 Error_Msg_N
7895 Error_Msg_N
7900 Error_Msg_N
7902 Typ);
7903 Error_Msg_N
7910 ------------------
7911 -- Freeze_Itype --
7912 ------------------
7917 begin
7926 --------------------------
7927 -- Freeze_Static_Object --
7928 --------------------------
7933 -- Exception raised if the type of a static object cannot be made
7934 -- static. This happens if the type depends on non-global objects.
7937 -- Called to ensure that an expression used as part of a type definition
7938 -- is statically allocatable, which means that the expression type is
7939 -- statically allocatable, and the expression is either static, or a
7940 -- reference to a library level constant.
7943 -- Called to mark a type as static, checking that it is possible
7944 -- to set the type as static. If it is not possible, then the
7945 -- exception Cannot_Be_Static is raised.
7947 -----------------------------
7948 -- Ensure_Expression_Is_SA --
7949 -----------------------------
7954 begin
7966 then
7974 -----------------------
7975 -- Ensure_Type_Is_SA --
7976 -----------------------
7982 begin
7983 -- If type is library level, we are all set
7989 -- We are also OK if the type already marked as statically allocated,
7990 -- which means we processed it before.
7996 -- Mark type as statically allocated
8000 -- Check that it is safe to statically allocate this type
8018 declare
8022 begin
8034 else
8043 then
8062 else
8067 -- Start of processing for Freeze_Static_Object
8069 begin
8072 exception
8075 -- If the object that cannot be static is imported or exported, then
8076 -- issue an error message saying that this object cannot be imported
8077 -- or exported. If it has an address clause it is an overlay in the
8078 -- current partition and the static requirement is not relevant.
8079 -- Do not issue any error message when ignoring rep clauses.
8086 Error_Msg_N
8090 -- Otherwise must be exported, something is wrong if compiler
8091 -- is marking something as statically allocated which cannot be).
8094 Error_Msg_N
8099 -----------------------
8100 -- Freeze_Subprogram --
8101 -----------------------
8105 -- Set the conventions of all anonymous access-to-subprogram formals and
8106 -- result subtype of subprogram Subp_Id to the convention of Subp_Id.
8108 ----------------------------
8109 -- Set_Profile_Convention --
8110 ----------------------------
8116 -- Set the convention of anonymous access-to-subprogram type Typ and
8117 -- its designated type to Conv.
8119 -------------------------
8120 -- Set_Type_Convention --
8121 -------------------------
8124 begin
8125 -- Set the convention on both the anonymous access-to-subprogram
8126 -- type and the subprogram type it points to because both types
8127 -- participate in conformance-related checks.
8135 -- Local variables
8139 -- Start of processing for Set_Profile_Convention
8141 begin
8153 -- Local variables
8158 -- Start of processing for Freeze_Subprogram
8160 begin
8161 -- Subprogram may not have an address clause unless it is imported
8165 Error_Msg_N
8171 -- Reset the Pure indication on an imported subprogram unless an
8172 -- explicit Pure_Function pragma was present or the subprogram is an
8173 -- intrinsic. We do this because otherwise it is an insidious error
8174 -- to call a non-pure function from pure unit and have calls
8175 -- mysteriously optimized away. What happens here is that the Import
8176 -- can bypass the normal check to ensure that pure units call only pure
8177 -- subprograms.
8179 -- The reason for the intrinsic exception is that in general, intrinsic
8180 -- functions (such as shifts) are pure anyway. The only exceptions are
8181 -- the intrinsics in GNAT.Source_Info, and that unit is not marked Pure
8182 -- in any case, so no problem arises.
8188 then
8192 -- We also reset the Pure indication on a subprogram with an Address
8193 -- parameter, because the parameter may be used as a pointer and the
8194 -- referenced data may change even if the address value does not.
8196 -- Note that if the programmer gave an explicit Pure_Function pragma,
8197 -- then we believe the programmer, and leave the subprogram Pure. We
8198 -- also suppress this check on run-time files.
8204 then
8208 -- Ensure that all anonymous access-to-subprogram types inherit the
8209 -- convention of their related subprogram (RM 6.3.1 13.1/3). This is
8210 -- not done for a defaulted convention Ada because those types also
8211 -- default to Ada. Convention Protected must not be propagated when
8212 -- the subprogram is an entry because this would be illegal. The only
8213 -- way to force convention Protected on these kinds of types is to
8214 -- include keyword "protected" in the access definition.
8218 then
8222 -- For non-foreign convention subprograms, this is where we create
8223 -- the extra formals (for accessibility level and constrained bit
8224 -- information). We delay this till the freeze point precisely so
8225 -- that we know the convention.
8234 -- If this is convention Ada and a Valued_Procedure, that's odd
8239 and then Warn_On_Export_Import
8240 then
8241 Error_Msg_N
8246 -- Case of foreign convention
8248 else
8251 -- For foreign conventions, warn about return of unconstrained array
8256 -- If no return type, probably some other error, e.g. a
8257 -- missing full declaration, so ignore.
8262 -- If the return type is generic, we have emitted a warning
8263 -- earlier on, and there is nothing else to check here. Specific
8264 -- instantiations may lead to erroneous behavior.
8269 -- Display warning if returning unconstrained array
8274 -- Check appropriate warning is enabled (should we check for
8275 -- Warnings (Off) on specific entities here, probably so???)
8277 and then Warn_On_Export_Import
8278 then
8279 Error_Msg_N
8286 -- If any of the formals for an exported foreign convention
8287 -- subprogram have defaults, then emit an appropriate warning since
8288 -- this is odd (default cannot be used from non-Ada code)
8293 if Warn_On_Export_Import
8295 then
8296 Error_Msg_N
8306 -- Pragma Inline_Always is disallowed for dispatching subprograms
8307 -- because the address of such subprograms is saved in the dispatch
8308 -- table to support dispatching calls, and dispatching calls cannot
8309 -- be inlined. This is consistent with the restriction against using
8310 -- 'Access or 'Address on an Inline_Always subprogram.
8314 then
8315 Error_Msg_N
8319 -- Because of the implicit representation of inherited predefined
8320 -- operators in the front-end, the overriding status of the operation
8321 -- may be affected when a full view of a type is analyzed, and this is
8322 -- not captured by the analysis of the corresponding type declaration.
8323 -- Therefore the correctness of a not-overriding indicator must be
8324 -- rechecked when the subprogram is frozen.
8328 then
8332 if Modify_Tree_For_C
8338 then
8343 ----------------------
8344 -- Is_Fully_Defined --
8345 ----------------------
8348 begin
8357 then
8358 -- Verify that the record type has no components with private types
8359 -- without completion.
8361 declare
8364 begin
8376 -- For the designated type of an access to subprogram, all types in
8377 -- the profile must be fully defined.
8380 declare
8383 begin
8396 else
8402 ---------------------------------
8403 -- Process_Default_Expressions --
8404 ---------------------------------
8406 procedure Process_Default_Expressions
8409 is
8416 begin
8419 -- A subprogram instance and its associated anonymous subprogram share
8420 -- their signature. The default expression functions are defined in the
8421 -- wrapper packages for the anonymous subprogram, and should not be
8422 -- generated again for the instance.
8427 then
8435 -- We work with a copy of the default expression because we
8436 -- do not want to disturb the original, since this would mess
8437 -- up the conformance checking.
8441 -- The analysis of the expression may generate insert actions,
8442 -- which of course must not be executed. We wrap those actions
8443 -- in a procedure that is not called, and later on eliminated.
8444 -- The following cases have no side effects, and are analyzed
8445 -- directly.
8449 N_Integer_Literal,
8450 N_Character_Literal,
8451 N_String_Literal,
8452 N_Real_Literal)
8456 then
8457 -- If there is no default function, we must still do a full
8458 -- analyze call on the default value, to ensure that all error
8459 -- checks are performed, e.g. those associated with static
8460 -- evaluation. Note: this branch will always be taken if the
8461 -- analyzer is turned off (but we still need the error checks).
8463 -- Note: the setting of parent here is to meet the requirement
8464 -- that we can only analyze the expression while attached to
8465 -- the tree. Really the requirement is that the parent chain
8466 -- be set, we don't actually need to be in the tree.
8471 -- Default expressions are resolved with their own type if the
8472 -- context is generic, to avoid anomalies with private types.
8476 else
8480 -- If that resolved expression will raise constraint error,
8481 -- then flag the default value as raising constraint error.
8482 -- This allows a proper error message on the calls.
8488 -- If the default is a parameterless call, we use the name of
8489 -- the called function directly, and there is no body to build.
8493 then
8496 -- Else construct and analyze the body of a wrapper procedure
8497 -- that contains an object declaration to hold the expression.
8498 -- Given that this is done only to complete the analysis, it is
8499 -- simpler to build a procedure than a function which might
8500 -- involve secondary stack expansion.
8502 else
8505 Dbody :=
8507 Specification =>
8514 Object_Definition =>
8518 Handled_Statement_Sequence =>
8535 ----------------------------------------
8536 -- Set_Component_Alignment_If_Not_Set --
8537 ----------------------------------------
8540 begin
8541 -- Ignore if not base type, subtypes don't need anything
8547 -- Do not override existing representation
8558 else
8559 Set_Component_Alignment
8565 --------------------------
8566 -- Set_SSO_From_Default --
8567 --------------------------
8572 begin
8573 -- Set default SSO for an array or record base type, except in case of
8574 -- a type extension (which always inherits the SSO of its parent type).
8581 then
8582 Reversed :=
8584 or else
8589 -- For a record type, if bit order is specified explicitly,
8590 -- then do not set SSO from default if not consistent. Note that
8591 -- we do not want to look at a Bit_Order attribute definition
8592 -- for a parent: if we were to inherit Bit_Order, then both
8593 -- SSO_Set_*_By_Default flags would have been cleared already
8594 -- (by Inherit_Aspects_At_Freeze_Point).
8596 and then not
8598 and then
8601 then
8602 -- If flags cause reverse storage order, then set the result. Note
8603 -- that we would have ignored the pragma setting the non default
8604 -- storage order in any case, hence the assertion at this point.
8606 pragma Assert
8611 -- For a record type, also set reversed bit order. Note: if a bit
8612 -- order has been specified explicitly, then this is a no-op.
8621 ------------------
8622 -- Undelay_Type --
8623 ------------------
8626 begin
8630 -- Since we don't want T to have a Freeze_Node, we don't want its
8631 -- Full_View or Corresponding_Record_Type to have one either.
8633 -- ??? Fundamentally, this whole handling is unpleasant. What we really
8634 -- want is to be sure that for an Itype that's part of record R and is a
8635 -- subtype of type T, that it's frozen after the later of the freeze
8636 -- points of R and T. We have no way of doing that directly, so what we
8637 -- do is force most such Itypes to be frozen as part of freezing R via
8638 -- this procedure and only delay the ones that need to be delayed
8639 -- (mostly the designated types of access types that are defined as part
8640 -- of the record).
8646 then
8654 then
8659 ------------------
8660 -- Warn_Overlay --
8661 ------------------
8665 -- The object to which the address clause applies
8671 begin
8672 -- No warning if address clause overlay warnings are off
8678 -- No warning if there is an explicit initialization
8686 -- We only give the warning for non-imported entities of a type for
8687 -- which a non-null base init proc is defined, or for objects of access
8688 -- types with implicit null initialization, or when Normalize_Scalars
8689 -- applies and the type is scalar or a string type (the latter being
8690 -- tested for because predefined String types are initialized by inline
8691 -- code rather than by an init_proc). Note that we do not give the
8692 -- warning for Initialize_Scalars, since we suppressed initialization
8693 -- in this case. Also, do not warn if Suppress_Initialization is set
8694 -- either on the type, or on the object via pragma or aspect.
8706 then
8709 then
8714 then
8721 then
8728 -- A function call (most likely to To_Address) is probably not an
8729 -- overlay, so skip warning. Ditto if the function call was inlined
8730 -- and transformed into an entity.
8736 -- If a pragma Import follows, we assume that it is for the current
8737 -- target of the address clause, and skip the warning. There may be
8738 -- a source pragma or an aspect that specifies import and generates
8739 -- the corresponding pragma. These will indicate that the entity is
8740 -- imported and that is checked above so that the spurious warning
8741 -- (generated when the entity is frozen) will be suppressed. The
8742 -- pragma may be attached to the aspect, so it is not yet a list
8743 -- member.
8751 then
8756 -- Otherwise give warning message
8760 Error_Msg_N
8762 Nam);
8763 else
8764 Error_Msg_N
8766 Nam);
8769 -- Add friendly warning if initialization comes from a packed array
8770 -- component.
8773 declare
8776 begin
8781 then
8785 then
8786 Error_Msg_NE
8791 else
8798 Error_Msg_N
8801 Nam);