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1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT COMPILER COMPONENTS --
4 -- --
5 -- S E M _ C H 1 2 --
6 -- --
7 -- B o d y --
8 -- --
9 -- Copyright (C) 1992-2014, 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 ------------------------------------------------------------------------------
85 ----------------------------------------------------------
86 -- Implementation of Generic Analysis and Instantiation --
87 ----------------------------------------------------------
89 -- GNAT implements generics by macro expansion. No attempt is made to share
90 -- generic instantiations (for now). Analysis of a generic definition does
91 -- not perform any expansion action, but the expander must be called on the
92 -- tree for each instantiation, because the expansion may of course depend
93 -- on the generic actuals. All of this is best achieved as follows:
94 --
95 -- a) Semantic analysis of a generic unit is performed on a copy of the
96 -- tree for the generic unit. All tree modifications that follow analysis
97 -- do not affect the original tree. Links are kept between the original
98 -- tree and the copy, in order to recognize non-local references within
99 -- the generic, and propagate them to each instance (recall that name
100 -- resolution is done on the generic declaration: generics are not really
101 -- macros). This is summarized in the following diagram:
103 -- .-----------. .----------.
104 -- | semantic |<--------------| generic |
105 -- | copy | | unit |
106 -- | |==============>| |
107 -- |___________| global |__________|
108 -- references | | |
109 -- | | |
110 -- .-----|--|.
111 -- | .-----|---.
112 -- | | .----------.
113 -- | | | generic |
114 -- |__| | |
115 -- |__| instance |
116 -- |__________|
118 -- b) Each instantiation copies the original tree, and inserts into it a
119 -- series of declarations that describe the mapping between generic formals
120 -- and actuals. For example, a generic In OUT parameter is an object
121 -- renaming of the corresponding actual, etc. Generic IN parameters are
122 -- constant declarations.
124 -- c) In order to give the right visibility for these renamings, we use
125 -- a different scheme for package and subprogram instantiations. For
126 -- packages, the list of renamings is inserted into the package
127 -- specification, before the visible declarations of the package. The
128 -- renamings are analyzed before any of the text of the instance, and are
129 -- thus visible at the right place. Furthermore, outside of the instance,
130 -- the generic parameters are visible and denote their corresponding
131 -- actuals.
133 -- For subprograms, we create a container package to hold the renamings
134 -- and the subprogram instance itself. Analysis of the package makes the
135 -- renaming declarations visible to the subprogram. After analyzing the
136 -- package, the defining entity for the subprogram is touched-up so that
137 -- it appears declared in the current scope, and not inside the container
138 -- package.
140 -- If the instantiation is a compilation unit, the container package is
141 -- given the same name as the subprogram instance. This ensures that
142 -- the elaboration procedure called by the binder, using the compilation
143 -- unit name, calls in fact the elaboration procedure for the package.
145 -- Not surprisingly, private types complicate this approach. By saving in
146 -- the original generic object the non-local references, we guarantee that
147 -- the proper entities are referenced at the point of instantiation.
148 -- However, for private types, this by itself does not insure that the
149 -- proper VIEW of the entity is used (the full type may be visible at the
150 -- point of generic definition, but not at instantiation, or vice-versa).
151 -- In order to reference the proper view, we special-case any reference
152 -- to private types in the generic object, by saving both views, one in
153 -- the generic and one in the semantic copy. At time of instantiation, we
154 -- check whether the two views are consistent, and exchange declarations if
155 -- necessary, in order to restore the correct visibility. Similarly, if
156 -- the instance view is private when the generic view was not, we perform
157 -- the exchange. After completing the instantiation, we restore the
158 -- current visibility. The flag Has_Private_View marks identifiers in the
159 -- the generic unit that require checking.
161 -- Visibility within nested generic units requires special handling.
162 -- Consider the following scheme:
164 -- type Global is ... -- outside of generic unit.
165 -- generic ...
166 -- package Outer is
167 -- ...
168 -- type Semi_Global is ... -- global to inner.
170 -- generic ... -- 1
171 -- procedure inner (X1 : Global; X2 : Semi_Global);
173 -- procedure in2 is new inner (...); -- 4
174 -- end Outer;
176 -- package New_Outer is new Outer (...); -- 2
177 -- procedure New_Inner is new New_Outer.Inner (...); -- 3
179 -- The semantic analysis of Outer captures all occurrences of Global.
180 -- The semantic analysis of Inner (at 1) captures both occurrences of
181 -- Global and Semi_Global.
183 -- At point 2 (instantiation of Outer), we also produce a generic copy
184 -- of Inner, even though Inner is, at that point, not being instantiated.
185 -- (This is just part of the semantic analysis of New_Outer).
187 -- Critically, references to Global within Inner must be preserved, while
188 -- references to Semi_Global should not preserved, because they must now
189 -- resolve to an entity within New_Outer. To distinguish between these, we
190 -- use a global variable, Current_Instantiated_Parent, which is set when
191 -- performing a generic copy during instantiation (at 2). This variable is
192 -- used when performing a generic copy that is not an instantiation, but
193 -- that is nested within one, as the occurrence of 1 within 2. The analysis
194 -- of a nested generic only preserves references that are global to the
195 -- enclosing Current_Instantiated_Parent. We use the Scope_Depth value to
196 -- determine whether a reference is external to the given parent.
198 -- The instantiation at point 3 requires no special treatment. The method
199 -- works as well for further nestings of generic units, but of course the
200 -- variable Current_Instantiated_Parent must be stacked because nested
201 -- instantiations can occur, e.g. the occurrence of 4 within 2.
203 -- The instantiation of package and subprogram bodies is handled in a
204 -- similar manner, except that it is delayed until after semantic
205 -- analysis is complete. In this fashion complex cross-dependencies
206 -- between several package declarations and bodies containing generics
207 -- can be compiled which otherwise would diagnose spurious circularities.
209 -- For example, it is possible to compile two packages A and B that
210 -- have the following structure:
212 -- package A is package B is
213 -- generic ... generic ...
214 -- package G_A is package G_B is
216 -- with B; with A;
217 -- package body A is package body B is
218 -- package N_B is new G_B (..) package N_A is new G_A (..)
220 -- The table Pending_Instantiations in package Inline is used to keep
221 -- track of body instantiations that are delayed in this manner. Inline
222 -- handles the actual calls to do the body instantiations. This activity
223 -- is part of Inline, since the processing occurs at the same point, and
224 -- for essentially the same reason, as the handling of inlined routines.
226 ----------------------------------------------
227 -- Detection of Instantiation Circularities --
228 ----------------------------------------------
230 -- If we have a chain of instantiations that is circular, this is static
231 -- error which must be detected at compile time. The detection of these
232 -- circularities is carried out at the point that we insert a generic
233 -- instance spec or body. If there is a circularity, then the analysis of
234 -- the offending spec or body will eventually result in trying to load the
235 -- same unit again, and we detect this problem as we analyze the package
236 -- instantiation for the second time.
238 -- At least in some cases after we have detected the circularity, we get
239 -- into trouble if we try to keep going. The following flag is set if a
240 -- circularity is detected, and used to abandon compilation after the
241 -- messages have been posted.
244 -- This should really be reset on encountering a new main unit, but in
245 -- practice we are not using multiple main units so it is not critical.
247 --------------------------------------------------
248 -- Formal packages and partial parameterization --
249 --------------------------------------------------
251 -- When compiling a generic, a formal package is a local instantiation. If
252 -- declared with a box, its generic formals are visible in the enclosing
253 -- generic. If declared with a partial list of actuals, those actuals that
254 -- are defaulted (covered by an Others clause, or given an explicit box
255 -- initialization) are also visible in the enclosing generic, while those
256 -- that have a corresponding actual are not.
258 -- In our source model of instantiation, the same visibility must be
259 -- present in the spec and body of an instance: the names of the formals
260 -- that are defaulted must be made visible within the instance, and made
261 -- invisible (hidden) after the instantiation is complete, so that they
262 -- are not accessible outside of the instance.
264 -- In a generic, a formal package is treated like a special instantiation.
265 -- Our Ada 95 compiler handled formals with and without box in different
266 -- ways. With partial parameterization, we use a single model for both.
267 -- We create a package declaration that consists of the specification of
268 -- the generic package, and a set of declarations that map the actuals
269 -- into local renamings, just as we do for bona fide instantiations. For
270 -- defaulted parameters and formals with a box, we copy directly the
271 -- declarations of the formal into this local package. The result is a
272 -- a package whose visible declarations may include generic formals. This
273 -- package is only used for type checking and visibility analysis, and
274 -- never reaches the back-end, so it can freely violate the placement
275 -- rules for generic formal declarations.
277 -- The list of declarations (renamings and copies of formals) is built
278 -- by Analyze_Associations, just as for regular instantiations.
280 -- At the point of instantiation, conformance checking must be applied only
281 -- to those parameters that were specified in the formal. We perform this
282 -- checking by creating another internal instantiation, this one including
283 -- only the renamings and the formals (the rest of the package spec is not
284 -- relevant to conformance checking). We can then traverse two lists: the
285 -- list of actuals in the instance that corresponds to the formal package,
286 -- and the list of actuals produced for this bogus instantiation. We apply
287 -- the conformance rules to those actuals that are not defaulted (i.e.
288 -- which still appear as generic formals.
290 -- When we compile an instance body we must make the right parameters
291 -- visible again. The predicate Is_Generic_Formal indicates which of the
292 -- formals should have its Is_Hidden flag reset.
294 -----------------------
295 -- Local subprograms --
296 -----------------------
300 -- Posts an error message "instantiation abandoned" at the indicated node
301 -- and then raises the exception Instantiation_Error to do it.
303 procedure Analyze_Formal_Array_Type
306 -- A formal array type is treated like an array type declaration, and
307 -- invokes Array_Type_Declaration (sem_ch3) whose first parameter is
308 -- in-out, because in the case of an anonymous type the entity is
309 -- actually created in the procedure.
311 -- The following procedures treat other kinds of formal parameters
313 procedure Analyze_Formal_Derived_Interface_Type
318 procedure Analyze_Formal_Derived_Type
323 procedure Analyze_Formal_Interface_Type
328 -- The following subprograms create abbreviated declarations for formal
329 -- scalar types. We introduce an anonymous base of the proper class for
330 -- each of them, and define the formals as constrained first subtypes of
331 -- their bases. The bounds are expressions that are non-static in the
332 -- generic.
334 procedure Analyze_Formal_Decimal_Fixed_Point_Type
340 procedure Analyze_Formal_Ordinary_Fixed_Point_Type
343 procedure Analyze_Formal_Private_Type
347 -- Creates a new private type, which does not require completion
350 -- Ada 2012: Creates a new incomplete type whose actual does not freeze
353 -- Analyze generic formal part
356 -- Create a new access type with the given designated type
358 function Analyze_Associations
362 -- At instantiation time, build the list of associations between formals
363 -- and actuals. Each association becomes a renaming declaration for the
364 -- formal entity. F_Copy is the analyzed list of formals in the generic
365 -- copy. It is used to apply legality checks to the actuals. I_Node is the
366 -- instantiation node itself.
368 procedure Analyze_Subprogram_Instantiation
372 procedure Build_Instance_Compilation_Unit_Nodes
376 -- This procedure is used in the case where the generic instance of a
377 -- subprogram body or package body is a library unit. In this case, the
378 -- original library unit node for the generic instantiation must be
379 -- replaced by the resulting generic body, and a link made to a new
380 -- compilation unit node for the generic declaration. The argument N is
381 -- the original generic instantiation. Act_Body and Act_Decl are the body
382 -- and declaration of the instance (either package body and declaration
383 -- nodes or subprogram body and declaration nodes depending on the case).
384 -- On return, the node N has been rewritten with the actual body.
387 -- Subsidiary routine to null exclusion processing. Perform an assertion
388 -- check on Ada version and the presence of an access definition in N.
391 -- Apply the following to all formal packages in generic associations
393 procedure Check_Formal_Package_Instance
396 -- Verify that the actuals of the actual instance match the actuals of
397 -- the template for a formal package that is not declared with a box.
400 -- If the generic is a local entity and the corresponding body has not
401 -- been seen yet, flag enclosing packages to indicate that it will be
402 -- elaborated after the generic body. Subprograms declared in the same
403 -- package cannot be inlined by the front-end because front-end inlining
404 -- requires a strict linear order of elaboration.
407 -- Check if some association between formals and actuals requires to make
408 -- visible primitives of a tagged type, and make those primitives visible.
409 -- Return the list of primitives whose visibility is modified (to restore
410 -- their visibility later through Restore_Hidden_Primitives). If no
411 -- candidate is found then return No_Elist.
413 procedure Check_Hidden_Child_Unit
417 -- If the generic unit is an implicit child instance within a parent
418 -- instance, we need to make an explicit test that it is not hidden by
419 -- a child instance of the same name and parent.
421 procedure Check_Generic_Actuals
424 -- Similar to previous one. Check the actuals in the instantiation,
425 -- whose views can change between the point of instantiation and the point
426 -- of instantiation of the body. In addition, mark the generic renamings
427 -- as generic actuals, so that they are not compatible with other actuals.
428 -- Recurse on an actual that is a formal package whose declaration has
429 -- a box.
431 function Contains_Instance_Of
435 -- Inner is instantiated within the generic Outer. Check whether Inner
436 -- directly or indirectly contains an instance of Outer or of one of its
437 -- parents, in the case of a subunit. Each generic unit holds a list of
438 -- the entities instantiated within (at any depth). This procedure
439 -- determines whether the set of such lists contains a cycle, i.e. an
440 -- illegal circular instantiation.
442 function Denotes_Formal_Package
446 -- Returns True if E is a formal package of an enclosing generic, or
447 -- the actual for such a formal in an enclosing instantiation. If such
448 -- a package is used as a formal in an nested generic, or as an actual
449 -- in a nested instantiation, the visibility of ITS formals should not
450 -- be modified. When called from within Restore_Private_Views, the flag
451 -- On_Exit is true, to indicate that the search for a possible enclosing
452 -- instance should ignore the current one. In that case Instance denotes
453 -- the declaration for which this is an actual. This declaration may be
454 -- an instantiation in the source, or the internal instantiation that
455 -- corresponds to the actual for a formal package.
458 -- Yields True if N1 and N2 appear in the same compilation unit,
459 -- ignoring subunits, and if N1 is to the left of N2 in a left-to-right
460 -- traversal of the tree for the unit. Used to determine the placement
461 -- of freeze nodes for instance bodies that may depend on other instances.
463 function Find_Actual_Type
466 -- When validating the actual types of a child instance, check whether
467 -- the formal is a formal type of the parent unit, and retrieve the current
468 -- actual for it. Typ is the entity in the analyzed formal type declaration
469 -- (component or index type of an array type, or designated type of an
470 -- access formal) and Gen_Type is the enclosing analyzed formal array
471 -- or access type. The desired actual may be a formal of a parent, or may
472 -- be declared in a formal package of a parent. In both cases it is a
473 -- generic actual type because it appears within a visible instance.
474 -- Finally, it may be declared in a parent unit without being a formal
475 -- of that unit, in which case it must be retrieved by visibility.
476 -- Ambiguities may still arise if two homonyms are declared in two formal
477 -- packages, and the prefix of the formal type may be needed to resolve
478 -- the ambiguity in the instance ???
480 function In_Same_Declarative_Part
483 -- True if the instantiation Inst and the given freeze_node F_Node appear
484 -- within the same declarative part, ignoring subunits, but with no inter-
485 -- vening subprograms or concurrent units. Used to find the proper plave
486 -- for the freeze node of an instance, when the generic is declared in a
487 -- previous instance. If predicate is true, the freeze node of the instance
488 -- can be placed after the freeze node of the previous instance, Otherwise
489 -- it has to be placed at the end of the current declarative part.
492 -- Check whether an instantiation is in the context of the main unit.
493 -- Used to determine whether its body should be elaborated to allow
494 -- front-end inlining.
496 procedure Set_Instance_Env
499 -- Save current instance on saved environment, to be used to determine
500 -- the global status of entities in nested instances. Part of Save_Env.
501 -- called after verifying that the generic unit is legal for the instance,
502 -- The procedure also examines whether the generic unit is a predefined
503 -- unit, in order to set configuration switches accordingly. As a result
504 -- the procedure must be called after analyzing and freezing the actuals.
507 -- Associate analyzed generic parameter with corresponding
508 -- instance. Used for semantic checks at instantiation time.
511 -- Traverse the Exchanged_Views list to see if a type was private
512 -- and has already been flipped during this phase of instantiation.
515 -- When instantiating a generic child unit, the parent context must be
516 -- present, but the instance and all entities that may be generated
517 -- must be inserted in the current scope. We leave the current scope
518 -- on the stack, but make its entities invisible to avoid visibility
519 -- problems. This is reversed at the end of the instantiation. This is
520 -- not done for the instantiation of the bodies, which only require the
521 -- instances of the generic parents to be in scope.
523 procedure Install_Body
528 -- If the instantiation happens textually before the body of the generic,
529 -- the instantiation of the body must be analyzed after the generic body,
530 -- and not at the point of instantiation. Such early instantiations can
531 -- happen if the generic and the instance appear in a package declaration
532 -- because the generic body can only appear in the corresponding package
533 -- body. Early instantiations can also appear if generic, instance and
534 -- body are all in the declarative part of a subprogram or entry. Entities
535 -- of packages that are early instantiations are delayed, and their freeze
536 -- node appears after the generic body.
538 procedure Insert_Freeze_Node_For_Instance
541 -- N denotes a package or a subprogram instantiation and F_Node is the
542 -- associated freeze node. Insert the freeze node before the first source
543 -- body which follows immediately after N. If no such body is found, the
544 -- freeze node is inserted at the end of the declarative region which
545 -- contains N.
547 procedure Freeze_Subprogram_Body
551 -- The generic body may appear textually after the instance, including
552 -- in the proper body of a stub, or within a different package instance.
553 -- Given that the instance can only be elaborated after the generic, we
554 -- place freeze_nodes for the instance and/or for packages that may enclose
555 -- the instance and the generic, so that the back-end can establish the
556 -- proper order of elaboration.
559 -- Establish environment for subsequent instantiation. Separated from
560 -- Save_Env because data-structures for visibility handling must be
561 -- initialized before call to Check_Generic_Child_Unit.
564 -- Install the visible part of any formal of the parent that is a formal
565 -- package. Note that for the case of a formal package with a box, this
566 -- includes the formal part of the formal package (12.7(10/2)).
569 -- When compiling an instance of a child unit the parent (which is
570 -- itself an instance) is an enclosing scope that must be made
571 -- immediately visible. This procedure is also used to install the non-
572 -- generic parent of a generic child unit when compiling its body, so
573 -- that full views of types in the parent are made visible.
576 -- Reverse effect after instantiation of child is complete
578 procedure Install_Hidden_Primitives
582 -- Remove suffix 'P' from hidden primitives of Act_T to match the
583 -- visibility of primitives of Gen_T. The list of primitives to which
584 -- the suffix is removed is added to Prims_List to restore them later.
587 -- Restore suffix 'P' to primitives of Prims_List and leave Prims_List
588 -- set to No_Elist.
590 procedure Inline_Instance_Body
594 -- If front-end inlining is requested, instantiate the package body,
595 -- and preserve the visibility of its compilation unit, to insure
596 -- that successive instantiations succeed.
598 -- The functions Instantiate_XXX perform various legality checks and build
599 -- the declarations for instantiated generic parameters. In all of these
600 -- Formal is the entity in the generic unit, Actual is the entity of
601 -- expression in the generic associations, and Analyzed_Formal is the
602 -- formal in the generic copy, which contains the semantic information to
603 -- be used to validate the actual.
605 function Instantiate_Object
610 function Instantiate_Type
616 function Instantiate_Formal_Subprogram
621 function Instantiate_Formal_Package
625 -- If the formal package is declared with a box, special visibility rules
626 -- apply to its formals: they are in the visible part of the package. This
627 -- is true in the declarative region of the formal package, that is to say
628 -- in the enclosing generic or instantiation. For an instantiation, the
629 -- parameters of the formal package are made visible in an explicit step.
630 -- Furthermore, if the actual has a visible USE clause, these formals must
631 -- be made potentially use-visible as well. On exit from the enclosing
632 -- instantiation, the reverse must be done.
634 -- For a formal package declared without a box, there are conformance rules
635 -- that apply to the actuals in the generic declaration and the actuals of
636 -- the actual package in the enclosing instantiation. The simplest way to
637 -- apply these rules is to repeat the instantiation of the formal package
638 -- in the context of the enclosing instance, and compare the generic
639 -- associations of this instantiation with those of the actual package.
640 -- This internal instantiation only needs to contain the renamings of the
641 -- formals: the visible and private declarations themselves need not be
642 -- created.
644 -- In Ada 2005, the formal package may be only partially parameterized.
645 -- In that case the visibility step must make visible those actuals whose
646 -- corresponding formals were given with a box. A final complication
647 -- involves inherited operations from formal derived types, which must
648 -- be visible if the type is.
651 -- Test if given node is in the main unit
653 procedure Load_Parent_Of_Generic
657 -- If the generic appears in a separate non-generic library unit, load the
658 -- corresponding body to retrieve the body of the generic. N is the node
659 -- for the generic instantiation, Spec is the generic package declaration.
660 --
661 -- Body_Optional is a flag that indicates that the body is being loaded to
662 -- ensure that temporaries are generated consistently when there are other
663 -- instances in the current declarative part that precede the one being
664 -- loaded. In that case a missing body is acceptable.
667 -- Add the context clause of the unit containing a generic unit to a
668 -- compilation unit that is, or contains, an instantiation.
671 -- In order to propagate semantic information back from the analyzed copy
672 -- to the original generic, we maintain links between selected nodes in the
673 -- generic and their corresponding copies. At the end of generic analysis,
674 -- the routine Save_Global_References traverses the generic tree, examines
675 -- the semantic information, and preserves the links to those nodes that
676 -- contain global information. At instantiation, the information from the
677 -- associated node is placed on the new copy, so that name resolution is
678 -- not repeated.
679 --
680 -- Three kinds of source nodes have associated nodes:
681 --
682 -- a) those that can reference (denote) entities, that is identifiers,
683 -- character literals, expanded_names, operator symbols, operators,
684 -- and attribute reference nodes. These nodes have an Entity field
685 -- and are the set of nodes that are in N_Has_Entity.
686 --
687 -- b) aggregates (N_Aggregate and N_Extension_Aggregate)
688 --
689 -- c) selected components (N_Selected_Component)
690 --
691 -- For the first class, the associated node preserves the entity if it is
692 -- global. If the generic contains nested instantiations, the associated
693 -- node itself has been recopied, and a chain of them must be followed.
694 --
695 -- For aggregates, the associated node allows retrieval of the type, which
696 -- may otherwise not appear in the generic. The view of this type may be
697 -- different between generic and instantiation, and the full view can be
698 -- installed before the instantiation is analyzed. For aggregates of type
699 -- extensions, the same view exchange may have to be performed for some of
700 -- the ancestor types, if their view is private at the point of
701 -- instantiation.
702 --
703 -- Nodes that are selected components in the parse tree may be rewritten
704 -- as expanded names after resolution, and must be treated as potential
705 -- entity holders, which is why they also have an Associated_Node.
706 --
707 -- Nodes that do not come from source, such as freeze nodes, do not appear
708 -- in the generic tree, and need not have an associated node.
709 --
710 -- The associated node is stored in the Associated_Node field. Note that
711 -- this field overlaps Entity, which is fine, because the whole point is
712 -- that we don't need or want the normal Entity field in this situation.
715 -- Within the generic part, entities in the formal package are
716 -- visible. To validate subsequent type declarations, indicate
717 -- the correspondence between the entities in the analyzed formal,
718 -- and the entities in the actual package. There are three packages
719 -- involved in the instantiation of a formal package: the parent
720 -- generic P1 which appears in the generic declaration, the fake
721 -- instantiation P2 which appears in the analyzed generic, and whose
722 -- visible entities may be used in subsequent formals, and the actual
723 -- P3 in the instance. To validate subsequent formals, me indicate
724 -- that the entities in P2 are mapped into those of P3. The mapping of
725 -- entities has to be done recursively for nested packages.
727 procedure Move_Freeze_Nodes
731 -- Freeze nodes can be generated in the analysis of a generic unit, but
732 -- will not be seen by the back-end. It is necessary to move those nodes
733 -- to the enclosing scope if they freeze an outer entity. We place them
734 -- at the end of the enclosing generic package, which is semantically
735 -- neutral.
738 -- Analyze actuals to perform name resolution. Full resolution is done
739 -- later, when the expected types are known, but names have to be captured
740 -- before installing parents of generics, that are not visible for the
741 -- actuals themselves.
744 -- For a subunit, return parent of corresponding stub, else return
745 -- parent of node.
748 -- Verify that an attribute that appears as the default for a formal
749 -- subprogram is a function or procedure with the correct profile.
751 -------------------------------------------
752 -- Data Structures for Generic Renamings --
753 -------------------------------------------
755 -- The map Generic_Renamings associates generic entities with their
756 -- corresponding actuals. Currently used to validate type instances. It
757 -- will eventually be used for all generic parameters to eliminate the
758 -- need for overload resolution in the instance.
778 -- Variable to hold enclosing instantiation. When the environment is
779 -- saved for a subprogram inlining, the corresponding Act_Id is empty.
783 -- Hash table for associations
806 -- This list holds the private views that have been exchanged during
807 -- instantiation to restore the visibility of the generic declaration.
808 -- (see comments above). After instantiation, the current visibility is
809 -- reestablished by means of a traversal of this list.
812 -- This list holds the entities of the current scope that are removed
813 -- from immediate visibility when instantiating a child unit. Their
814 -- visibility is restored in Remove_Parent.
816 -- Because instantiations can be recursive, the following must be saved
817 -- on entry and restored on exit from an instantiation (spec or body).
818 -- This is done by the two procedures Save_Env and Restore_Env. For
819 -- package and subprogram instantiations (but not for the body instances)
820 -- the action of Save_Env is done in two steps: Init_Env is called before
821 -- Check_Generic_Child_Unit, because setting the parent instances requires
822 -- that the visibility data structures be properly initialized. Once the
823 -- generic is unit is validated, Set_Instance_Env completes Save_Env.
826 -- Parent_Unit_Visible is used when the generic is a child unit, and
827 -- indicates whether the ultimate parent of the generic is visible in the
828 -- instantiation environment. It is used to reset the visibility of the
829 -- parent at the end of the instantiation (see Remove_Parent).
832 -- This records the ultimate parent unit of an instance of a generic
833 -- child unit and is used in conjunction with Parent_Unit_Visible to
834 -- indicate the unit to which the Parent_Unit_Visible flag corresponds.
854 procedure Restore_Private_Views
857 -- Restore the private views of external types, and unmark the generic
858 -- renamings of actuals, so that they become compatible subtypes again.
859 -- For subprograms, Pack_Id is the package constructed to hold the
860 -- renamings.
863 -- Switch the partial and full views of a type and its private
864 -- dependents (i.e. its subtypes and derived types).
866 ------------------------------------
867 -- Structures for Error Reporting --
868 ------------------------------------
871 -- Used by subprograms that validate instantiation of formal parameters
872 -- where there might be no actual on which to place the error message.
873 -- Also used to locate the instantiation node for generic subunits.
876 -- When there is a semantic error in the generic parameter matching,
877 -- there is no point in continuing the instantiation, because the
878 -- number of cascaded errors is unpredictable. This exception aborts
879 -- the instantiation process altogether.
882 -- Offset created for each node in an instantiation, in order to keep
883 -- track of the source position of the instantiation in each of its nodes.
884 -- A subsequent semantic error or warning on a construct of the instance
885 -- points to both places: the original generic node, and the point of
886 -- instantiation. See Sinput and Sinput.L for additional details.
888 ------------------------------------------------------------
889 -- Data structure for keeping track when inside a Generic --
890 ------------------------------------------------------------
892 -- The following table is used to save values of the Inside_A_Generic
893 -- flag (see spec of Sem) when they are saved by Start_Generic.
903 ---------------------------
904 -- Abandon_Instantiation --
905 ---------------------------
908 begin
913 --------------------------
914 -- Analyze_Associations --
915 --------------------------
917 function Analyze_Associations
921 is
938 -- If an Others_Choice is present, some of the formals may be defaulted.
939 -- To simplify the treatment of visibility in an instance, we introduce
940 -- individual defaults for each such formal. These defaults are
941 -- appended to the list of associations and replace the Others_Choice.
944 -- Association for the current formal being match. Empty if there are
945 -- no remaining actuals, or if there is no named association with the
946 -- name of the formal.
954 -- In Ada 2005, indicates partial parameterization of a formal
955 -- package. As usual an other association must be last in the list.
957 function Build_Function_Wrapper
960 -- In GNATprove mode, create a wrapper function for actuals that are
961 -- functions with any number of formal parameters, in order to propagate
962 -- their contract to the renaming declarations generated for them.
963 -- If the actual is absent, the formal has a default, and the name of
964 -- the function is that of the formal.
966 function Build_Operator_Wrapper
969 -- In GNATprove mode, create a wrapper function for actuals that are
970 -- operators, in order to propagate their contract to the renaming
971 -- declarations generated for them. If the actual is absent, this is
972 -- a formal with a default, and the name of the operator is that of the
973 -- formal.
976 -- Apply RM 12.3 (9): if a formal subprogram is overloaded, the instance
977 -- cannot have a named association for it. AI05-0025 extends this rule
978 -- to formals of formal packages by AI05-0025, and it also applies to
979 -- box-initialized formals.
982 -- Determine whether the parameter types and the return type of Subp
983 -- are fully defined at the point of instantiation.
985 function Matching_Actual
988 -- Find actual that corresponds to a given a formal parameter. If the
989 -- actuals are positional, return the next one, if any. If the actuals
990 -- are named, scan the parameter associations to find the right one.
991 -- A_F is the corresponding entity in the analyzed generic,which is
992 -- placed on the selector name for ASIS use.
993 --
994 -- In Ada 2005, a named association may be given with a box, in which
995 -- case Matching_Actual sets Found_Assoc to the generic association,
996 -- but return Empty for the actual itself. In this case the code below
997 -- creates a corresponding declaration for the formal.
1000 -- Ada 2005: if no match is found for a given formal, check if the
1001 -- association for it includes a box, or whether the associations
1002 -- include an Others clause.
1005 -- Add a copy of the declaration of generic formal F to the list of
1006 -- associations, and add an explicit box association for F if there
1007 -- is none yet, and the default comes from an Others_Choice.
1010 -- Determine whether Subp renames one of the subprograms defined in the
1011 -- generated package Standard.
1014 -- Find the node in the generic copy that corresponds to a given formal.
1015 -- The semantic information on this node is used to perform legality
1016 -- checks on the actuals. Because semantic analysis can introduce some
1017 -- anonymous entities or modify the declaration node itself, the
1018 -- correspondence between the two lists is not one-one. In addition to
1019 -- anonymous types, the presence a formal equality will introduce an
1020 -- implicit declaration for the corresponding inequality.
1022 ----------------------------
1023 -- Build_Function_Wrapper --
1024 ----------------------------
1026 function Build_Function_Wrapper
1029 is
1042 begin
1043 -- If there is no actual, the formal has a default and is retrieved
1044 -- by name. Otherwise the wrapper encloses a call to the actual.
1048 else
1061 else
1068 -- Create new formal for profile of wrapper, and add a reference
1069 -- to it in the list of actuals for the enclosing call. The name
1070 -- must be that of the formal in the formal subprogram, because
1071 -- calls to it in the generic body may use named associations.
1077 -- If formal has a class-wide type rewrite as the corresponding
1078 -- attribute, because the class-wide type is not retrievable by
1079 -- visbility.
1082 Parm_Type :=
1085 Prefix =>
1088 else
1089 Parm_Type :=
1093 -- If actual is present, use the type of its own formal
1095 else
1112 Spec :=
1116 Result_Definition =>
1119 Decl :=
1122 Expression =>
1130 ----------------------------
1131 -- Build_Operator_Wrapper --
1132 ----------------------------
1134 function Build_Operator_Wrapper
1137 is
1151 begin
1154 else
1158 -- Create entities for wrapper function and its formals
1169 Spec :=
1175 Parameter_Type =>
1184 Parameter_Type =>
1189 -- Build expression as a function call, or as an operator node
1190 -- that corresponds to the name of the actual, starting with binary
1191 -- operators.
1194 Expr :=
1196 Name =>
1204 -- Binary operators
1243 -- Unary operators
1245 else
1257 -- Propagate visible entity to operator node, either from a
1258 -- given actual or from a default.
1264 Decl :=
1272 ----------------------------------------
1273 -- Check_Overloaded_Formal_Subprogram --
1274 ----------------------------------------
1279 begin
1284 and then
1287 then
1289 Error_Msg_N
1291 Found_Assoc);
1293 else
1294 Error_Msg_N
1296 Others_Choice);
1306 -------------------------------
1307 -- Has_Fully_Defined_Profile --
1308 -------------------------------
1312 -- Determine whethet type Typ is fully defined
1314 ---------------------------
1315 -- Is_Fully_Defined_Type --
1316 ---------------------------
1319 begin
1320 -- A private type without a full view is not fully defined
1324 then
1327 -- An incomplete type is never fully defined
1332 -- All other types are fully defined
1334 else
1339 -- Local declarations
1343 -- Start of processing for Has_Fully_Defined_Profile
1345 begin
1346 -- Check the parameters
1357 -- Check the return type
1362 ---------------------
1363 -- Matching_Actual --
1364 ---------------------
1366 function Matching_Actual
1369 is
1373 begin
1376 -- End of list of purely positional parameters
1382 -- Case of positional parameter corresponding to current formal
1390 -- Otherwise scan list of named actuals to find the one with the
1391 -- desired name. All remaining actuals have explicit names.
1393 else
1414 -- Reset for subsequent searches. In most cases the named
1415 -- associations are in order. If they are not, we reorder them
1416 -- to avoid scanning twice the same actual. This is not just a
1417 -- question of efficiency: there may be multiple defaults with
1418 -- boxes that have the same name. In a nested instantiation we
1419 -- insert actuals for those defaults, and cannot rely on their
1420 -- names to disambiguate them.
1439 ------------------------------
1440 -- Partial_Parameterization --
1441 ------------------------------
1444 begin
1445 return Others_Present
1449 ---------------------
1450 -- Process_Default --
1451 ---------------------
1460 begin
1461 -- Append copy of formal declaration to associations, and create new
1462 -- defining identifier for it.
1470 else
1477 Default :=
1486 ---------------------------------
1487 -- Renames_Standard_Subprogram --
1488 ---------------------------------
1493 begin
1506 -------------------------
1507 -- Set_Analyzed_Formal --
1508 -------------------------
1513 begin
1521 and then
1522 Chars
1524 Chars
1529 N_Generic_Package_Declaration,
1530 N_Package_Declaration);
1536 -- Skip freeze nodes, and nodes inserted to replace
1537 -- unrecognized pragmas.
1539 exit when
1540 Kind not in N_Formal_Subprogram_Declaration
1542 N_Freeze_Entity,
1543 N_Null_Statement,
1544 N_Itype_Reference)
1553 -- Start of processing for Analyze_Associations
1555 begin
1560 -- Check for an Others choice, indicating a partial parameterization
1561 -- for a formal package.
1573 -- This subprogram is used both for formal packages and for
1574 -- instantiations. For the latter, associations must all be
1575 -- explicit.
1579 then
1580 Error_Msg_N
1582 Actual);
1585 -- In any case, nothing to do after the others association
1592 then
1593 Error_Msg_N
1600 -- If named associations are present, save first named association
1601 -- (it may of course be Empty) to facilitate subsequent name search.
1607 loop
1617 then
1622 -- A named association may lack an actual parameter, if it was
1623 -- introduced for a default subprogram that turns out to be local
1624 -- to the outer instantiation.
1628 then
1642 -- All formals should have default values
1644 else
1649 Set_Analyzed_Formal;
1654 Match :=
1655 Matching_Actual (
1661 else
1662 Append_List
1664 Assoc);
1667 -- If the object is a call to an expression function, this
1668 -- is a freezing point for it.
1672 and then Nkind
1674 = N_Expression_Function
1675 then
1680 Match :=
1681 Matching_Actual (
1689 else
1691 Error_Msg_NE
1693 Instantiation_Node,
1700 else
1702 Append_List
1703 (Instantiate_Type
1705 Assoc);
1707 -- An instantiation is a freeze point for the actuals,
1708 -- unless this is a rewritten formal package, or the
1709 -- formal is an Ada 2012 formal incomplete type.
1712 or else
1714 and then
1716 E_Incomplete_Type)
1717 then
1720 else
1725 -- A remote access-to-class-wide type is not a legal actual
1726 -- for a generic formal of an access type (E.2.2(17/2)).
1727 -- In GNAT an exception to this rule is introduced when
1728 -- the formal is marked as remote using implementation
1729 -- defined aspect/pragma Remote_Access_Type. In that case
1730 -- the actual must be remote as well.
1732 -- If the current instantiation is the construction of a
1733 -- local copy for a formal package the actuals may be
1734 -- defaulted, and there is no matching actual to check.
1737 and then
1739 N_Access_To_Object_Definition
1741 then
1742 declare
1745 begin
1748 then
1749 -- Remoteness of formal and actual match
1755 -- Remote formal, non-remote actual
1757 Error_Msg_NE
1760 else
1761 -- Non-remote formal, remote actual
1763 Error_Msg_NE
1771 Match :=
1772 Matching_Actual
1776 -- If the formal subprogram has the same name as another
1777 -- formal subprogram of the generic, then a named
1778 -- association is illegal (12.3(9)). Exclude named
1779 -- associations that are generated for a nested instance.
1782 and then Is_Named_Assoc
1784 then
1788 -- If there is no corresponding actual, this may be case
1789 -- of partial parameterization, or else the formal has a
1790 -- default or a box.
1799 else
1800 if GNATprove_Mode
1801 and then Present
1802 (Containing_Package_With_Ext_Axioms
1805 E_Function
1806 then
1807 -- If actual is an entity (function or operator),
1808 -- build wrapper for it.
1813 -- If the name is a default, find its visible
1814 -- entity at the point of instantiation.
1818 then
1822 Append_To
1824 Build_Operator_Wrapper
1827 else
1829 Build_Function_Wrapper
1833 -- Ditto if formal is an operator with a default.
1837 N_Defining_Operator_Symbol
1838 then
1840 Build_Operator_Wrapper
1843 -- Otherwise create renaming declaration.
1845 else
1847 Build_Function_Wrapper
1851 else
1853 Instantiate_Formal_Subprogram
1857 -- An instantiation is a freeze point for the actuals,
1858 -- unless this is a rewritten formal package.
1864 -- The actual subprogram may rename a routine defined
1865 -- in Standard. Avoid freezing such renamings because
1866 -- subprograms coming from Standard cannot be frozen.
1868 and then
1871 -- If the actual subprogram comes from a different
1872 -- unit, it is already frozen, either by a body in
1873 -- that unit or by the end of the declarative part
1874 -- of the unit. This check avoids the freezing of
1875 -- subprograms defined in Standard which are used
1876 -- as generic actuals.
1880 then
1881 -- Mark the subprogram as having a delayed freeze
1882 -- since this may be an out-of-order action.
1889 -- If this is a nested generic, preserve default for later
1890 -- instantiations.
1893 Append_Elmt
1895 Default_Actuals);
1899 Match :=
1900 Matching_Actual (
1908 else
1910 Error_Msg_NE
1919 else
1921 Append_List
1922 (Instantiate_Formal_Package
1924 Assoc);
1927 -- For use type and use package appearing in the generic part,
1928 -- we have already copied them, so we can just move them where
1929 -- they belong (we mustn't recopy them since this would mess up
1930 -- the Sloc values).
1932 when N_Use_Package_Clause |
1933 N_Use_Type_Clause =>
1935 N_Formal_Package_Declaration
1936 then
1938 else
1956 Error_Msg_NE
1961 else
1962 Error_Msg_NE
1969 Error_Msg_N
1973 -- An instantiation freezes all generic actuals. The only exceptions
1974 -- to this are incomplete types and subprograms which are not fully
1975 -- defined at the point of instantiation.
1977 declare
1979 begin
1986 -- If there are default subprograms, normalize the tree by adding
1987 -- explicit associations for them. This is required if the instance
1988 -- appears within a generic.
1990 declare
1995 begin
2004 New_D :=
2007 Explicit_Generic_Actual_Parameter =>
2015 -- If this is a formal package, normalize the parameter list by adding
2016 -- explicit box associations for the formals that are covered by an
2017 -- Others_Choice.
2026 -------------------------------
2027 -- Analyze_Formal_Array_Type --
2028 -------------------------------
2030 procedure Analyze_Formal_Array_Type
2033 is
2036 begin
2037 -- Treated like a non-generic array declaration, with additional
2038 -- semantic checks.
2046 N_Range,
2047 N_Attribute_Reference)
2048 then
2061 then
2064 -- Check that range constraint is not allowed on the component type
2065 -- of a generic formal array type (AARM 12.5.3(3))
2071 N_Subtype_Indication
2072 then
2073 Error_Msg_N
2081 ---------------------------------------------
2082 -- Analyze_Formal_Decimal_Fixed_Point_Type --
2083 ---------------------------------------------
2085 -- As for other generic types, we create a valid type representation with
2086 -- legal but arbitrary attributes, whose values are never considered
2087 -- static. For all scalar types we introduce an anonymous base type, with
2088 -- the same attributes. We choose the corresponding integer type to be
2089 -- Standard_Integer.
2090 -- Here and in other similar routines, the Sloc of the generated internal
2091 -- type must be the same as the sloc of the defining identifier of the
2092 -- formal type declaration, to provide proper source navigation.
2094 procedure Analyze_Formal_Decimal_Fixed_Point_Type
2097 is
2101 New_Internal_Entity
2103 Current_Scope,
2111 -- Return a properly typed universal real literal to use as a bound
2113 ----------------------
2114 -- Make_Dummy_Bound --
2115 ----------------------
2119 begin
2124 -- Start of processing for Analyze_Formal_Decimal_Fixed_Point_Type
2126 begin
2158 -------------------------------------------
2159 -- Analyze_Formal_Derived_Interface_Type --
2160 -------------------------------------------
2162 procedure Analyze_Formal_Derived_Interface_Type
2166 is
2169 begin
2170 -- Rewrite as a type declaration of a derived type. This ensures that
2171 -- the interface list and primitive operations are properly captured.
2181 ---------------------------------
2182 -- Analyze_Formal_Derived_Type --
2183 ---------------------------------
2185 procedure Analyze_Formal_Derived_Type
2189 is
2194 begin
2198 New_N :=
2210 else
2211 New_N :=
2214 Discriminant_Specifications =>
2216 Type_Definition =>
2220 Set_Abstract_Present
2222 Set_Limited_Present
2231 Error_Msg_N
2233 else
2239 -- If the parent type has a known size, so does the formal, which makes
2240 -- legal representation clauses that involve the formal.
2242 Set_Size_Known_At_Compile_Time
2246 ----------------------------------
2247 -- Analyze_Formal_Discrete_Type --
2248 ----------------------------------
2250 -- The operations defined for a discrete types are those of an enumeration
2251 -- type. The size is set to an arbitrary value, for use in analyzing the
2252 -- generic unit.
2260 New_Internal_Entity
2264 begin
2273 -- For semantic analysis, the bounds of the type must be set to some
2274 -- non-static value. The simplest is to create attribute nodes for those
2275 -- bounds, that refer to the type itself. These bounds are never
2276 -- analyzed but serve as place-holders.
2278 Lo :=
2284 Hi :=
2304 ----------------------------------
2305 -- Analyze_Formal_Floating_Type --
2306 ---------------------------------
2310 New_Internal_Entity
2314 begin
2315 -- The various semantic attributes are taken from the predefined type
2316 -- Float, just so that all of them are initialized. Their values are
2317 -- never used because no constant folding or expansion takes place in
2318 -- the generic itself.
2340 -----------------------------------
2341 -- Analyze_Formal_Interface_Type;--
2342 -----------------------------------
2344 procedure Analyze_Formal_Interface_Type
2348 is
2352 begin
2353 New_N :=
2363 ---------------------------------
2364 -- Analyze_Formal_Modular_Type --
2365 ---------------------------------
2368 begin
2369 -- Apart from their entity kind, generic modular types are treated like
2370 -- signed integer types, and have the same attributes.
2378 ---------------------------------------
2379 -- Analyze_Formal_Object_Declaration --
2380 ---------------------------------------
2388 begin
2391 -- Determine the mode of the formal object
2400 else
2408 -- Verify that there is no redundant null exclusion
2412 Error_Msg_N
2416 Error_Msg_NE
2422 -- Ada 2005 (AI-423): Formal object with an access definition
2424 else
2426 T := Access_Definition
2432 declare
2435 begin
2438 else
2449 -- Ada 2005 (AI-287): Limited aggregates allowed in generic formals
2452 Error_Msg_N
2458 Error_Msg_N
2466 Error_Msg_N
2475 -- Case of generic IN OUT parameter
2477 else
2478 -- If the formal has an unconstrained type, construct its actual
2479 -- subtype, as is done for subprogram formals. In this fashion, all
2480 -- its uses can refer to specific bounds.
2487 then
2488 declare
2493 begin
2494 -- Make sure the actual subtype doesn't generate bogus freezing
2501 else
2506 Error_Msg_N
2516 ----------------------------------------------
2517 -- Analyze_Formal_Ordinary_Fixed_Point_Type --
2518 ----------------------------------------------
2520 procedure Analyze_Formal_Ordinary_Fixed_Point_Type
2523 is
2526 New_Internal_Entity
2530 begin
2531 -- The semantic attributes are set for completeness only, their values
2532 -- will never be used, since all properties of the type are non-static.
2559 ----------------------------------------
2560 -- Analyze_Formal_Package_Declaration --
2561 ----------------------------------------
2578 -- List of primitives made temporarily visible in the instantiation
2579 -- to match the visibility of the formal type
2582 -- The formal package is rewritten so that its parameters are replaced
2583 -- with corresponding declarations. For parameters with bona fide
2584 -- associations these declarations are created by Analyze_Associations
2585 -- as for a regular instantiation. For boxed parameters, we preserve
2586 -- the formal declarations and analyze them, in order to introduce
2587 -- entities of the right kind in the environment of the formal.
2589 -------------------------
2590 -- Build_Local_Package --
2591 -------------------------
2597 begin
2598 -- Within the formal, the name of the generic package is a renaming
2599 -- of the formal (as for a regular instantiation).
2601 Pack_Decl :=
2603 Specification =>
2604 Copy_Generic_Node
2609 Defining_Unit_Name =>
2615 then
2616 Error_Msg_NE
2620 -- If the formal is declared with a box, or with an others choice,
2621 -- create corresponding declarations for all entities in the formal
2622 -- part, so that names with the proper types are available in the
2623 -- specification of the formal package.
2625 -- On the other hand, if there are no associations, then all the
2626 -- formals must have defaults, and this will be checked by the
2627 -- call to Analyze_Associations.
2631 then
2632 declare
2635 begin
2636 -- TBA : for a formal package, need to recurse ???
2639 Formal_Decl :=
2640 First
2643 Append_To
2649 -- If generic associations are present, use Analyze_Associations to
2650 -- create the proper renaming declarations.
2652 else
2653 declare
2655 Copy_Generic_Node
2659 begin
2664 Decls :=
2665 Analyze_Associations
2676 -- Add generated declarations ahead of local declarations in
2677 -- the package.
2681 else
2682 Insert_List_Before
2684 Decls);
2690 -- Start of processing for Analyze_Formal_Package_Declaration
2692 begin
2695 Init_Env;
2699 -- Check for a formal package that is a package renaming
2703 -- Indicate that unit is used, before replacing it with renamed
2704 -- entity for use below.
2716 Restore_Env;
2720 Error_Msg_N
2722 Gen_Id);
2723 Restore_Env;
2729 then
2730 -- Special-case the error when the formal is a parent, and
2731 -- continue analysis to minimize cascaded errors.
2733 Error_Msg_N
2736 Gen_Id);
2738 else
2739 Error_Msg_N
2742 Gen_Id);
2743 Restore_Env;
2748 -- Check that name of formal package does not hide name of generic,
2749 -- or its leading prefix. This check must be done separately because
2750 -- the name of the generic has already been analyzed.
2752 declare
2755 begin
2762 Error_Msg_NE
2771 then
2775 -- If there are no generic associations, the generic parameters appear
2776 -- as local entities and are instantiated like them. We copy the generic
2777 -- package declaration as if it were an instantiation, and analyze it
2778 -- like a regular package, except that we treat the formals as
2779 -- additional visible components.
2791 begin
2792 -- Make local generic without formals. The formals will be replaced
2793 -- with internal declarations.
2797 -- If there are errors in the parameter list, Analyze_Associations
2798 -- raises Instantiation_Error. Patch the declaration to prevent
2799 -- further exception propagation.
2801 exception
2810 Remove_Parent;
2829 and then Parent_Installed
2830 then
2831 -- Similarly, we have to make the name of the formal visible in the
2832 -- parent instance, to resolve properly fully qualified names that
2833 -- may appear in the generic unit. The parent instance has been
2834 -- placed on the scope stack ahead of the current scope.
2838 Renaming_In_Par :=
2850 -- The formals for which associations are provided are not visible
2851 -- outside of the formal package. The others are still declared by a
2852 -- formal parameter declaration.
2854 -- If there are no associations, the only local entity to hide is the
2855 -- generated package renaming itself.
2857 declare
2860 begin
2863 if Associations
2865 then
2871 then
2884 Remove_Parent;
2887 Restore_Env;
2889 -- Inside the generic unit, the formal package is a regular package, but
2890 -- no body is needed for it. Note that after instantiation, the defining
2891 -- unit name we need is in the new tree and not in the original (see
2892 -- Package_Instantiation). A generic formal package is an instance, and
2893 -- can be used as an actual for an inner instance.
2897 -- Add semantic information to the original defining identifier.
2898 -- for ASIS use.
2911 ---------------------------------
2912 -- Analyze_Formal_Private_Type --
2913 ---------------------------------
2915 procedure Analyze_Formal_Private_Type
2919 is
2920 begin
2923 -- Set the size to an arbitrary but legal value
2929 ------------------------------------
2930 -- Analyze_Formal_Incomplete_Type --
2931 ------------------------------------
2933 procedure Analyze_Formal_Incomplete_Type
2936 is
2937 begin
2950 ----------------------------------------
2951 -- Analyze_Formal_Signed_Integer_Type --
2952 ----------------------------------------
2954 procedure Analyze_Formal_Signed_Integer_Type
2957 is
2959 New_Internal_Entity
2961 Current_Scope,
2964 begin
2982 -------------------------------------------
2983 -- Analyze_Formal_Subprogram_Declaration --
2984 -------------------------------------------
2992 begin
3010 declare
3012 begin
3014 Error_Msg_N
3016 N);
3020 then
3021 Error_Msg_NE
3025 else
3031 -- Default name is resolved at the point of instantiation
3036 -- Else default is bound at the point of generic declaration
3045 else
3046 -- For an attribute reference, analyze the prefix and verify
3047 -- that it has the proper profile for the subprogram.
3054 -- Default name may be overloaded, in which case the interpretation
3055 -- with the correct profile must be selected, as for a renaming.
3056 -- If the definition is an indexed component, it must denote a
3057 -- member of an entry family. If it is a selected component, it
3058 -- can be a protected operation.
3076 E_Entry_Family
3077 then
3081 else
3088 -- Needs some type checks: subprogram should be parameterless???
3094 then
3108 -- More than one interpretation, so disambiguate as for a renaming
3110 else
3111 declare
3117 begin
3127 else
3133 else
3145 -- Subprogram found, generate reference to it
3157 else
3170 -------------------------------------
3171 -- Analyze_Formal_Type_Declaration --
3172 -------------------------------------
3178 begin
3183 then
3184 Error_Msg_N
3188 -- Enter the new name, and branch to specific routine
3221 when N_Access_To_Object_Definition |
3222 N_Access_Function_Definition |
3223 N_Access_Procedure_Definition =>
3226 -- Ada 2005: a interface declaration is encoded as an abstract
3227 -- record declaration or a abstract type derivation.
3250 ------------------------------------
3251 -- Analyze_Function_Instantiation --
3252 ------------------------------------
3255 begin
3259 ---------------------------------
3260 -- Analyze_Generic_Access_Type --
3261 ---------------------------------
3264 begin
3273 then
3277 Error_Msg_N
3281 else
3286 ---------------------------------
3287 -- Analyze_Generic_Formal_Part --
3288 ---------------------------------
3293 begin
3294 -- The generic formals are processed in the scope of the generic unit,
3295 -- where they are immediately visible. The scope is installed by the
3296 -- caller.
3308 ------------------------------------------
3309 -- Analyze_Generic_Package_Declaration --
3310 ------------------------------------------
3322 begin
3325 -- We introduce a renaming of the enclosing package, to have a usable
3326 -- entity as the prefix of an expanded name for a local entity of the
3327 -- form Par.P.Q, where P is the generic package. This is because a local
3328 -- entity named P may hide it, so that the usual visibility rules in
3329 -- the instance will not resolve properly.
3331 Renaming :=
3333 Defining_Unit_Name =>
3342 loop
3348 else
3352 else
3356 -- Create copy of generic unit, and save for instantiation. If the unit
3357 -- is a child unit, do not copy the specifications for the parent, which
3358 -- are not part of the generic tree.
3367 -- Once the contents of the generic copy and the template are swapped,
3368 -- do the same for their respective aspect specifications.
3374 -- Expansion is not applied to generic units
3376 Start_Generic;
3383 -- A generic package declared within a Ghost scope is rendered Ghost
3384 -- (SPARK RM 6.9(2)).
3390 -- Analyze aspects now, so that generated pragmas appear in the
3391 -- declarations before building and analyzing the generic copy.
3404 -- Link the declaration of the generic homonym in the generic copy to
3405 -- the package it renames, so that it is always resolved properly.
3410 -- For a library unit, we have reconstructed the entity for the unit,
3411 -- and must reset it in the library tables.
3419 -- After processing the generic formals, analysis proceeds as for a
3420 -- non-generic package.
3426 End_Generic;
3436 else
3440 -- If this is a spec without a body, check that generic parameters
3441 -- are referenced.
3448 -- If there is a specified storage pool in the context, create an
3449 -- aspect on the package declaration, so that it is used in any
3450 -- instance that does not override it.
3453 declare
3456 begin
3457 ASN :=
3464 else
3471 --------------------------------------------
3472 -- Analyze_Generic_Subprogram_Declaration --
3473 --------------------------------------------
3484 begin
3487 -- Create copy of generic unit, and save for instantiation. If the unit
3488 -- is a child unit, do not copy the specifications for the parent, which
3489 -- are not part of the generic tree.
3498 -- Once the contents of the generic copy and the template are swapped,
3499 -- do the same for their respective aspect specifications.
3509 Error_Msg_N
3513 Start_Generic;
3518 -- Analyze the aspects of the generic copy to ensure that all generated
3519 -- pragmas (if any) perform their semantic effects.
3545 -- Check restriction imposed by AI05-073: a generic function
3546 -- cannot return an abstract type or an access to such.
3548 -- This is a binding interpretation should it apply to earlier
3549 -- versions of Ada as well as Ada 2012???
3553 then
3558 else
3564 then
3565 Error_Msg_N
3569 -- If a null exclusion is imposed on the result type, then create
3570 -- a null-excluding itype (an access subtype) and use it as the
3571 -- function's Etype.
3575 then
3577 Create_Null_Excluding_Itype
3581 else
3586 else
3591 -- A generic subprogram declared within a Ghost scope is rendered Ghost
3592 -- (SPARK RM 6.9(2)).
3598 -- For a library unit, we have reconstructed the entity for the unit,
3599 -- and must reset it in the library tables. We also make sure that
3600 -- Body_Required is set properly in the original compilation unit node.
3612 -- For ASIS purposes, convert any postcondition, precondition pragmas
3613 -- into aspects, if N is not a compilation unit by itself, in order to
3614 -- enable the analysis of expressions inside the corresponding PPC
3615 -- pragmas.
3621 End_Generic;
3622 End_Scope;
3629 -----------------------------------
3630 -- Analyze_Package_Instantiation --
3631 -----------------------------------
3658 -- Save flag Ignore_Pragma_SPARK_Mode for restore on exit
3662 -- Save the SPARK_Mode-related data for restore on exit
3665 -- Save style check mode for restore on exit
3668 -- Delay generation of subprogram descriptors for given entity
3671 -- If inlining is active and the generic contains inlined subprograms,
3672 -- we instantiate the body. This may cause superfluous instantiations,
3673 -- but it is simpler than detecting the need for the body at the point
3674 -- of inlining, when the context of the instance is not available.
3676 -----------------------
3677 -- Delay_Descriptors --
3678 -----------------------
3681 begin
3688 -----------------------
3689 -- Might_Inline_Subp --
3690 -----------------------
3695 begin
3699 else
3713 -- Local declarations
3716 -- List of primitives made temporarily visible in the instantiation
3717 -- to match the visibility of the formal type
3719 -- Start of processing for Analyze_Package_Instantiation
3721 begin
3724 -- Very first thing: check for Text_IO sp[ecial unit in case we are
3725 -- instantiating one of the children of [[Wide_]Wide_]Text_IO.
3729 -- Make node global for error reporting
3733 -- Turn off style checking in instances. If the check is enabled on the
3734 -- generic unit, a warning in an instance would just be noise. If not
3735 -- enabled on the generic, then a warning in an instance is just wrong.
3739 -- Case of instantiation of a generic package
3746 Act_Decl_Name :=
3750 else
3754 -- Case of instantiation of a formal package
3756 else
3764 Init_Env;
3767 -- Reset renaming map for formal types. The mapping is established
3768 -- when analyzing the generic associations, but some mappings are
3769 -- inherited from formal packages of parent units, and these are
3770 -- constructed when the parents are installed.
3778 -- Verify that it is the name of a generic package
3780 -- A visibility glitch: if the instance is a child unit and the generic
3781 -- is the generic unit of a parent instance (i.e. both the parent and
3782 -- the child units are instances of the same package) the name now
3783 -- denotes the renaming within the parent, not the intended generic
3784 -- unit. See if there is a homonym that is the desired generic. The
3785 -- renaming declaration must be visible inside the instance of the
3786 -- child, but not when analyzing the name in the instantiation itself.
3793 then
3798 Restore_Env;
3803 -- Ada 2005 (AI-50217): Cannot use instance in limited with_clause
3806 Error_Msg_N
3808 else
3809 Error_Msg_NE
3813 Restore_Env;
3829 then
3830 Error_Msg_NE
3837 then
3838 Error_Msg_N
3844 -- If generic is a renaming, get original generic unit
3848 then
3852 -- Verify that there are no circular instantiations
3856 Restore_Env;
3861 Error_Msg_NE
3864 Restore_Env;
3867 else
3868 -- If the context of the instance is subject to SPARK_Mode "off",
3869 -- set the global flag which signals Analyze_Pragma to ignore all
3870 -- SPARK_Mode pragmas within the instance.
3879 -- Initialize renamings map, for error checking, and the list that
3880 -- holds private entities whose views have changed between generic
3881 -- definition and instantiation. If this is the instance created to
3882 -- validate an actual package, the instantiation environment is that
3883 -- of the enclosing instance.
3887 -- Copy original generic tree, to produce text for instantiation
3889 Act_Tree :=
3890 Copy_Generic_Node
3895 -- If this is the instance created to validate an actual package,
3896 -- only the formals matter, do not examine the package spec itself.
3903 Renaming_List :=
3904 Analyze_Associations
3916 -- References to the generic in its own declaration or its body are
3917 -- references to the instance. Add a renaming declaration for the
3918 -- generic unit itself. This declaration, as well as the renaming
3919 -- declarations for the generic formals, must remain private to the
3920 -- unit: the formals, because this is the language semantics, and
3921 -- the unit because its use is an artifact of the implementation.
3923 Unit_Renaming :=
3925 Defining_Unit_Name =>
3931 -- The renaming declarations are the first local declarations of the
3932 -- new unit.
3935 Insert_List_Before
3937 else
3943 -- Propagate the aspect specifications from the package declaration
3944 -- template to the instantiated version of the package declaration.
3951 -- The generic may have a generated Default_Storage_Pool aspect,
3952 -- set at the point of generic declaration. If the instance has
3953 -- that aspect, it overrides the one inherited from the generic.
3958 (New_Copy_List_Tree
3961 else
3962 declare
3965 begin
3969 = Name_Default_Storage_Pool
3970 then
3971 -- If generic carries a default storage pool, remove
3972 -- it in favor of the instance one.
3977 Name_Default_Storage_Pool
3978 then
3991 (New_Copy_List_Tree
3997 -- Save the instantiation node, for subsequent instantiation of the
3998 -- body, if there is one and we are generating code for the current
3999 -- unit. Mark unit as having a body (avoids premature error message).
4001 -- We instantiate the body if we are generating code, if we are
4002 -- generating cross-reference information, or if we are building
4003 -- trees for ASIS use or GNATprove use.
4005 declare
4007 -- If the generic unit is not a compilation unit, then a body may
4008 -- be present in its parent even if none is required. We create a
4009 -- tentative pending instantiation for the body, which will be
4010 -- discarded if none is actually present.
4014 begin
4017 then
4022 loop
4029 then
4039 -- If front-end inlining is enabled, and this is a unit for which
4040 -- code will be generated, we instantiate the body at once.
4042 -- This is done if the instance is not the main unit, and if the
4043 -- generic is not a child unit of another generic, to avoid scope
4044 -- problems and the reinstallation of parent instances.
4046 if Expander_Active
4049 and then Might_Inline_Subp
4050 and then not Is_Actual_Pack
4051 then
4052 if not Back_End_Inlining
4053 and then Front_End_Inlining
4057 then
4060 -- In configurable_run_time mode we force the inlining of
4061 -- predefined subprograms marked Inline_Always, to minimize
4062 -- the use of the run-time library.
4064 elsif Is_Predefined_File_Name
4066 and then Configurable_Run_Time_Mode
4068 then
4072 -- If the current scope is itself an instance within a child
4073 -- unit, there will be duplications in the scope stack, and the
4074 -- unstacking mechanism in Inline_Instance_Body will fail.
4075 -- This loses some rare cases of optimization, and might be
4076 -- improved some day, if we can find a proper abstraction for
4077 -- "the complete compilation context" that can be saved and
4078 -- restored. ???
4081 declare
4084 begin
4087 then
4094 Needs_Body :=
4096 or else Enclosing_Body_Present
4099 and then not Is_Actual_Pack
4100 and then not Inline_Now
4103 -- Need comment for this check ???
4108 -- If front_end_inlining is enabled, do not instantiate body if
4109 -- within a generic context.
4113 then
4117 -- If the current context is generic, and the package being
4118 -- instantiated is declared within a formal package, there is no
4119 -- body to instantiate until the enclosing generic is instantiated
4120 -- and there is an actual for the formal package. If the formal
4121 -- package has parameters, we build a regular package instance for
4122 -- it, that precedes the original formal package declaration.
4125 declare
4127 Original_Node
4129 begin
4134 and then
4136 N_Formal_Package_Declaration)
4137 then
4144 -- For RCI unit calling stubs, we omit the instance body if the
4145 -- instance is the RCI library unit itself.
4147 -- However there is a special case for nested instances: in this case
4148 -- we do generate the instance body, as it might be required, e.g.
4149 -- because it provides stream attributes for some type used in the
4150 -- profile of a remote subprogram. This is consistent with 12.3(12),
4151 -- which indicates that the instance body occurs at the place of the
4152 -- instantiation, and thus is part of the RCI declaration, which is
4153 -- present on all client partitions (this is E.2.3(18)).
4155 -- Note that AI12-0002 may make it illegal at some point to have
4156 -- stream attributes defined in an RCI unit, in which case this
4157 -- special case will become unnecessary. In the meantime, there
4158 -- is known application code in production that depends on this
4159 -- being possible, so we definitely cannot eliminate the body in
4160 -- the case of nested instances for the time being.
4162 -- When we generate a nested instance body, calling stubs for any
4163 -- relevant subprogram will be be inserted immediately after the
4164 -- subprogram declarations, and will take precedence over the
4165 -- subsequent (original) body. (The stub and original body will be
4166 -- complete homographs, but this is permitted in an instance).
4167 -- (Could we do better and remove the original body???)
4172 then
4178 -- Here is a defence against a ludicrous number of instantiations
4179 -- caused by a circular set of instantiation attempts.
4188 -- Indicate that the enclosing scopes contain an instantiation,
4189 -- and that cleanup actions should be delayed until after the
4190 -- instance body is expanded.
4194 declare
4197 begin
4198 -- Loop to search enclosing masters
4205 Delay_Descriptors
4207 else
4208 Delay_Descriptors
4214 else
4220 then
4221 -- Cleanup actions will eventually be performed on the
4222 -- enclosing subprogram or package instance, if any.
4223 -- Enclosing scope is void in the formal part of a
4224 -- generic subprogram.
4228 else
4230 and then
4232 then
4235 else
4236 Enclosing_Master :=
4251 declare
4253 Get_Task_Body_Procedure
4255 begin
4268 -- Make entry in table
4270 Pending_Instantiations.Append
4288 Hide_Current_Scope;
4293 -- If not a compilation unit, insert the package declaration before
4294 -- the original instantiation node.
4303 -- The pragma created for a Default_Storage_Pool aspect must
4304 -- appear ahead of the declarations in the instance spec.
4305 -- Analysis has placed it after the instance node, so remove
4306 -- it and reinsert it properly now.
4308 declare
4313 begin
4335 -- For an instantiation that is a compilation unit, place
4336 -- declaration on current node so context is complete for analysis
4337 -- (including nested instantiations). If this is the main unit,
4338 -- the declaration eventually replaces the instantiation node.
4339 -- If the instance body is created later, it replaces the
4340 -- instance node, and the declaration is attached to it
4341 -- (see Build_Instance_Compilation_Unit_Nodes).
4343 else
4346 -- The entity for the current unit is the newly created one,
4347 -- and all semantic information is attached to it.
4351 -- If this is the main unit, replace the main entity as well
4362 -- Process aspect specifications of the instance node, if any, to
4363 -- take into account categorization pragmas before analyzing the
4364 -- instance.
4374 -- We never need elaboration checks on instantiations, since by
4375 -- definition, the body instantiation is elaborated at the same
4376 -- time as the spec instantiation.
4393 -- If the instantiation will receive a body, the unit will be
4394 -- transformed into a package body, and receive its own elaboration
4395 -- entity. Otherwise, the nature of the unit is now a package
4396 -- declaration.
4399 and then not Needs_Body
4400 then
4406 then
4418 Remove_Parent;
4421 Restore_Env;
4427 -- There used to be a check here to prevent instantiations in local
4428 -- contexts if the No_Local_Allocators restriction was active. This
4429 -- check was removed by a binding interpretation in AI-95-00130/07,
4430 -- but we retain the code for documentation purposes.
4432 -- if Ekind (Act_Decl_Id) /= E_Void
4433 -- and then not Is_Library_Level_Entity (Act_Decl_Id)
4434 -- then
4435 -- Check_Restriction (No_Local_Allocators, N);
4436 -- end if;
4442 -- The following is a tree patch for ASIS: ASIS needs separate nodes to
4443 -- be used as defining identifiers for a formal package and for the
4444 -- corresponding expanded package.
4458 -- Check that if N is an instantiation of System.Dim_Float_IO or
4459 -- System.Dim_Integer_IO, the formal type has a dimension system.
4463 then
4464 declare
4466 begin
4467 if not Has_Dimension_System
4469 then
4480 exception
4483 Remove_Parent;
4487 Restore_Env;
4496 --------------------------
4497 -- Inline_Instance_Body --
4498 --------------------------
4500 procedure Inline_Instance_Body
4504 is
4512 -- Save all SPARK_Mode-related attributes as removing enclosing scopes
4513 -- to provide a clean environment for analysis of the inlined body will
4514 -- eliminate any previously set SPARK_Mode.
4531 begin
4532 -- Case of generic unit defined in another unit. We must remove the
4533 -- complete context of the current unit to install that of the generic.
4537 -- Add some comments for the following two loops ???
4541 loop
4547 First_Use_Clause);
4564 -- Find and save all enclosing instances
4570 loop
4581 -- Remove context of current compilation unit, unless we are within a
4582 -- nested package instantiation, in which case the context has been
4583 -- removed previously.
4585 -- If current scope is the body of a child unit, remove context of
4586 -- spec as well. If an enclosing scope is an instance body, the
4587 -- context has already been removed, but the entities in the body
4588 -- must be made invisible as well.
4594 loop
4598 then
4599 -- We still have to remove the entities of the enclosing
4600 -- instance from direct visibility.
4602 declare
4604 begin
4620 Corresponding_Spec
4622 then
4625 -- Remove entities in current scopes from visibility, so that
4626 -- instance body is compiled in a clean environment.
4632 -- Remove child unit from stack, as well as inner scopes.
4633 -- Removing the context of a child unit removes parent units
4634 -- as well.
4639 Pop_Scope;
4642 Pop_Scope;
4646 else
4660 -- The inlined package body must be analyzed with the SPARK_Mode of
4661 -- the enclosing context, otherwise the body may cause bogus errors
4662 -- if a configuration SPARK_Mode pragma in in effect.
4666 Instantiate_Package_Body
4681 Pop_Scope;
4683 -- Restore context
4687 -- Reset Generic_Instance flag so that use clauses can be installed
4688 -- in the proper order. (See Use_One_Package for effect of enclosing
4689 -- instances on processing of use clauses).
4700 then
4704 -- Finally, restore inner scopes as well
4714 and then
4717 then
4718 -- Install private declaration of ancestor units, which are
4719 -- currently available. Restore_Scope_Stack and Install_Context
4720 -- only install the visible part of parents.
4722 declare
4724 begin
4728 loop
4736 -- Restore use clauses. For a child unit, use clauses in the parents
4737 -- are restored when installing the context, so only those in inner
4738 -- scopes (and those local to the child unit itself) need to be
4739 -- installed explicitly.
4742 and then Removed
4743 then
4750 else
4758 -- Restore status of instances. If one of them is a body, make its
4759 -- local entities visible again.
4761 declare
4765 begin
4772 then
4782 -- If generic unit is in current unit, current context is correct. Note
4783 -- that the context is guaranteed to carry the correct SPARK_Mode as no
4784 -- enclosing scopes were removed.
4786 else
4787 Instantiate_Package_Body
4804 -------------------------------------
4805 -- Analyze_Procedure_Instantiation --
4806 -------------------------------------
4809 begin
4813 -----------------------------------
4814 -- Need_Subprogram_Instance_Body --
4815 -----------------------------------
4817 function Need_Subprogram_Instance_Body
4820 is
4821 begin
4822 -- Must be inlined (or inlined renaming)
4828 -- Must be generating code or analyzing code in ASIS/GNATprove mode
4834 -- The body is needed when generating code (full expansion), in ASIS
4835 -- mode for other tools, and in GNATprove mode (special expansion) for
4836 -- formal verification of the body itself.
4840 -- No point in inlining if ABE is inevitable
4844 -- Or if subprogram is eliminated
4847 then
4848 Pending_Instantiations.Append
4862 -- Here if not inlined, or we ignore the inlining
4864 else
4869 --------------------------------------
4870 -- Analyze_Subprogram_Instantiation --
4871 --------------------------------------
4873 procedure Analyze_Subprogram_Instantiation
4876 is
4882 Chars => New_External_Name
4898 -- The instance must be analyzed in a context that includes the mappings
4899 -- of generic parameters into actuals. We create a package declaration
4900 -- for this purpose, and a subprogram with an internal name within the
4901 -- package. The subprogram instance is simply an alias for the internal
4902 -- subprogram, declared in the current scope.
4904 ------------------------------------
4905 -- Analyze_Instance_And_Renamings --
4906 ------------------------------------
4912 begin
4915 -- For the case of a compilation unit, the container package has
4916 -- the same name as the instantiation, to insure that the binder
4917 -- calls the elaboration procedure with the right name. Copy the
4918 -- entity of the instance, which may have compilation level flags
4919 -- (e.g. Is_Child_Unit) set.
4923 else
4924 -- Otherwise we use the name of the instantiation concatenated
4925 -- with its source position to ensure uniqueness if there are
4926 -- several instantiations with the same name.
4928 Pack_Id :=
4930 Chars => New_External_Name
4946 -- Case of not a compilation unit
4953 -- Case of an instantiation that is a compilation unit
4955 -- Place declaration on current node so context is complete for
4956 -- analysis (including nested instantiations), and for use in a
4957 -- context_clause (see Analyze_With_Clause).
4959 else
4968 -- Why do we clear Is_Generic_Instance??? We set it 20 lines
4969 -- above???
4971 -- Body of the enclosing package is supplied when instantiating the
4972 -- subprogram body, after semantic analysis is completed.
4976 -- Remove package itself from visibility, so it does not
4977 -- conflict with subprogram.
4981 -- Set name and scope of internal subprogram so that the proper
4982 -- external name will be generated. The proper scope is the scope
4983 -- of the wrapper package. We need to generate debugging info for
4984 -- the internal subprogram, so set flag accordingly.
4989 -- Mark wrapper package as referenced, to avoid spurious warnings
4990 -- if the instantiation appears in various with_ clauses of
4991 -- subunits of the main unit.
5005 -- The signature may involve types that are not frozen yet, but the
5006 -- subprogram will be frozen at the point the wrapper package is
5007 -- frozen, so it does not need its own freeze node. In fact, if one
5008 -- is created, it might conflict with the freezing actions from the
5009 -- wrapper package.
5013 -- If the instance is a child unit, mark the Id accordingly. Mark
5014 -- the anonymous entity as well, which is the real subprogram and
5015 -- which is used when the instance appears in a context clause.
5016 -- Similarly, propagate the Is_Eliminated flag to handle properly
5017 -- nested eliminated subprograms.
5025 -- In compilation unit case, kill elaboration checks on the
5026 -- instantiation, since they are never needed -- the body is
5027 -- instantiated at the same point as the spec.
5037 -- The instance is not a freezing point for the new subprogram
5055 -- Local variables
5058 -- Save flag Ignore_Pragma_SPARK_Mode for restore on exit
5062 -- Save the SPARK_Mode-related data for restore on exit
5065 -- List of primitives made temporarily visible in the instantiation
5066 -- to match the visibility of the formal type
5068 -- Start of processing for Analyze_Subprogram_Instantiation
5070 begin
5073 -- Very first thing: check for special Text_IO unit in case we are
5074 -- instantiating one of the children of [[Wide_]Wide_]Text_IO. Of course
5075 -- such an instantiation is bogus (these are packages, not subprograms),
5076 -- but we get a better error message if we do this.
5080 -- Make node global for error reporting
5084 -- For package instantiations we turn off style checks, because they
5085 -- will have been emitted in the generic. For subprogram instantiations
5086 -- we want to apply at least the check on overriding indicators so we
5087 -- do not modify the style check status.
5089 -- The renaming declarations for the actuals do not come from source and
5090 -- will not generate spurious warnings.
5094 Init_Env;
5103 then
5104 Error_Msg_NE
5109 Restore_Env;
5113 -- Verify that it is a generic subprogram of the right kind, and that
5114 -- it does not lead to a circular instantiation.
5117 Error_Msg_NE
5121 Error_Msg_NE
5127 else
5128 -- If the context of the instance is subject to SPARK_Mode "off",
5129 -- set the global flag which signals Analyze_Pragma to ignore all
5130 -- SPARK_Mode pragmas within the instance.
5143 -- If renaming, get original unit
5147 E_Generic_Function)
5148 then
5156 Error_Msg_NE
5165 -- Initialize renamings map, for error checking
5172 -- Copy original generic tree, to produce text for instantiation
5174 Act_Tree :=
5175 Copy_Generic_Node
5178 -- Inherit overriding indicator from instance node
5184 Renaming_List :=
5185 Analyze_Associations
5192 -- The subprogram itself cannot contain a nested instance, so the
5193 -- current parent is left empty.
5197 -- Build the subprogram declaration, which does not appear in the
5198 -- generic template, and give it a sloc consistent with that of the
5199 -- template.
5203 Act_Decl :=
5207 -- The aspects have been copied previously, but they have to be
5208 -- linked explicitly to the new subprogram declaration. Explicit
5209 -- pre/postconditions on the instance are analyzed below, in a
5210 -- separate step.
5216 Hide_Current_Scope;
5220 Analyze_Instance_And_Renamings;
5222 -- If the generic is marked Import (Intrinsic), then so is the
5223 -- instance. This indicates that there is no body to instantiate. If
5224 -- generic is marked inline, so it the instance, and the anonymous
5225 -- subprogram it renames. If inlined, or else if inlining is enabled
5226 -- for the compilation, we generate the instance body even if it is
5227 -- not within the main unit.
5238 -- Inherit convention from generic unit. Intrinsic convention, as for
5239 -- an instance of unchecked conversion, is not inherited because an
5240 -- explicit Ada instance has been created.
5244 then
5250 -- Set_Contract (Anon_Id, Make_Contract (Sloc (Anon_Id)));
5251 -- ??? needed?
5254 -- Inherit all inlining-related flags which apply to the generic in
5255 -- the subprogram and its declaration.
5263 Set_Has_Pragma_Inline_Always
5265 Set_Has_Pragma_Inline_Always
5274 then
5275 declare
5278 begin
5284 then
5287 Error_Msg_NE
5306 -- If the context requires a full instantiation, mark node for
5307 -- subsequent construction of the body.
5312 -- The wrapper package is always delayed, because it does not
5313 -- constitute a freeze point, but to insure that the freeze
5314 -- node is placed properly, it is created directly when
5315 -- instantiating the body (otherwise the freeze node might
5316 -- appear to early for nested instantiations).
5320 -- For ASIS purposes, indicate that the wrapper package has
5321 -- replaced the instantiation node.
5329 -- Replace instance node for library-level instantiations of
5330 -- intrinsic subprograms, for ASIS use.
5337 Remove_Parent;
5341 Restore_Env;
5356 exception
5359 Remove_Parent;
5363 Restore_Env;
5371 -------------------------
5372 -- Get_Associated_Node --
5373 -------------------------
5378 begin
5387 else
5388 -- If the node is part of an inner generic, it may itself have been
5389 -- remapped into a further generic copy. Associated_Node is otherwise
5390 -- used for the entity of the node, and will be of a different node
5391 -- kind, or else N has been rewritten as a literal or function call.
5395 loop
5399 -- Follow and additional link in case the final node was rewritten.
5400 -- This can only happen with nested generic units.
5405 N_Explicit_Dereference,
5406 N_Integer_Literal,
5407 N_Real_Literal,
5408 N_String_Literal))
5409 then
5413 -- An additional special case: an unconstrained type in an object
5414 -- declaration may have been rewritten as a local subtype constrained
5415 -- by the expression in the declaration. We need to recover the
5416 -- original entity which may be global.
5420 then
5428 -------------------------------------------
5429 -- Build_Instance_Compilation_Unit_Nodes --
5430 -------------------------------------------
5432 procedure Build_Instance_Compilation_Unit_Nodes
5436 is
5443 begin
5444 -- A new compilation unit node is built for the instance declaration
5446 Decl_Cunit :=
5454 -- The new compilation unit is linked to its body, but both share the
5455 -- same file, so we do not set Body_Required on the new unit so as not
5456 -- to create a spurious dependency on a non-existent body in the ali.
5457 -- This simplifies CodePeer unit traversal.
5459 -- We use the original instantiation compilation unit as the resulting
5460 -- compilation unit of the instance, since this is the main unit.
5464 -- Propagate the aspect specifications from the package body template to
5465 -- the instantiated version of the package body.
5468 Set_Aspect_Specifications
5474 -- The two compilation unit nodes are linked by the Library_Unit field
5479 -- Preserve the private nature of the package if needed
5483 -- If the instance is not the main unit, its context, categorization
5484 -- and elaboration entity are not relevant to the compilation.
5491 -- The context clause items on the instantiation, which are now attached
5492 -- to the body compilation unit (since the body overwrote the original
5493 -- instantiation node), semantically belong on the spec, so copy them
5494 -- there. It's harmless to leave them on the body as well. In fact one
5495 -- could argue that they belong in both places.
5503 -- Propagate categorization flags on packages, so that they appear in
5504 -- the ali file for the spec of the unit.
5511 Set_Is_Remote_Call_Interface
5515 -- Make entry in Units table, so that binder can generate call to
5516 -- elaboration procedure for body, if any.
5522 -- Build elaboration entity, since the instance may certainly generate
5523 -- elaboration code requiring a flag for protection.
5528 -----------------------------
5529 -- Check_Access_Definition --
5530 -----------------------------
5533 begin
5534 pragma Assert
5539 -----------------------------------
5540 -- Check_Formal_Package_Instance --
5541 -----------------------------------
5543 -- If the formal has specific parameters, they must match those of the
5544 -- actual. Both of them are instances, and the renaming declarations for
5545 -- their formal parameters appear in the same order in both. The analyzed
5546 -- formal has been analyzed in the context of the current instance.
5548 procedure Check_Formal_Package_Instance
5551 is
5559 -- Common error routine for mismatch between the parameters of the
5560 -- actual instance and those of the formal package.
5563 -- The formal may come from a nested formal package, and the actual may
5564 -- have been constant-folded. To determine whether the two denote the
5565 -- same entity we may have to traverse several definitions to recover
5566 -- the ultimate entity that they refer to.
5569 -- Similarly, if the formal comes from a nested formal package, the
5570 -- actual may designate the formal through multiple renamings, which
5571 -- have to be followed to determine the original variable in question.
5573 --------------------
5574 -- Check_Mismatch --
5575 --------------------
5580 begin
5585 N_Formal_Package_Declaration)
5587 then
5591 Error_Msg_NE
5597 --------------------------------
5598 -- Same_Instantiated_Constant --
5599 --------------------------------
5601 function Same_Instantiated_Constant
5603 is
5606 begin
5618 else
5622 -- The actual may be a constant that has been folded. Recover
5623 -- original name.
5627 else
5635 --------------------------------
5636 -- Same_Instantiated_Variable --
5637 --------------------------------
5639 function Same_Instantiated_Variable
5641 is
5643 -- Follow chain of renamings to the ultimate ancestor
5645 ---------------------
5646 -- Original_Entity --
5647 ---------------------
5652 begin
5657 loop
5664 -- Start of processing for Same_Instantiated_Variable
5666 begin
5671 -- Start of processing for Check_Formal_Package_Instance
5673 begin
5676 loop
5680 -- If the formal is the renaming of the formal package, this
5681 -- is the end of its formal part, which may occur before the
5682 -- end of the formal part in the actual in the presence of
5683 -- defaulted parameters in the formal package.
5688 -- The analysis of the actual may generate additional internal
5689 -- entities. If the formal is defaulted, there is no corresponding
5690 -- analysis and the internal entities must be skipped, until we
5691 -- find corresponding entities again.
5696 then
5699 loop
5707 -- If the formal entity comes from a formal declaration, it was
5708 -- defaulted in the formal package, and no check is needed on it.
5713 -- Ditto for defaulted formal subprograms.
5717 N_Formal_Subprogram_Declaration
5718 then
5723 -- Subtypes must statically match. E1, E2 are the local entities
5724 -- that are subtypes of the actuals. Itypes generated for other
5725 -- parameters need not be checked, the check will be performed
5726 -- on the parameters themselves.
5728 -- If E2 is a formal type declaration, it is a defaulted parameter
5729 -- and needs no checking.
5733 then
5734 Check_Mismatch
5742 -- IN parameters must denote the same static value, or the same
5743 -- constant, or the literal null.
5750 else
5759 declare
5762 begin
5767 declare
5770 begin
5776 then
5779 else
5780 Check_Mismatch
5789 else
5790 Check_Mismatch
5794 else
5800 and then
5801 Same_Instantiated_Constant
5803 then
5809 else
5817 Check_Mismatch
5823 -- Verify that the actual subprograms match. Note that actuals
5824 -- that are attributes are rewritten as subprograms. If the
5825 -- subprogram in the formal package is defaulted, no check is
5826 -- needed. Note that this can only happen in Ada 2005 when the
5827 -- formal package can be partially parameterized.
5830 N_Subprogram_Renaming_Declaration
5832 then
5835 -- If the formal package has an "others" box association that
5836 -- covers this formal, there is no need for a check either.
5839 N_Formal_Subprogram_Declaration
5841 then
5844 -- No check needed if subprogram is a defaulted null procedure
5848 and then
5850 then
5853 -- Otherwise the actual in the formal and the actual in the
5854 -- instantiation of the formal must match, up to renamings.
5856 else
5857 Check_Mismatch
5861 else
5871 ---------------------------
5872 -- Check_Formal_Packages --
5873 ---------------------------
5879 begin
5880 -- Iterate through the declarations in the instance, looking for package
5881 -- renaming declarations that denote instances of formal packages. Stop
5882 -- when we find the renaming of the current package itself. The
5883 -- declaration for a formal package without a box is followed by an
5884 -- internal entity that repeats the instantiation.
5899 -- After checking, remove the internal validating package. It
5900 -- is only needed for semantic checks, and as it may contain
5901 -- generic formal declarations it should not reach gigi.
5911 ---------------------------------
5912 -- Check_Forward_Instantiation --
5913 ---------------------------------
5919 begin
5920 -- The instantiation appears before the generic body if we are in the
5921 -- scope of the unit containing the generic, either in its spec or in
5922 -- the package body, and before the generic body.
5930 then
5936 loop
5946 ---------------------------
5947 -- Check_Generic_Actuals --
5948 ---------------------------
5950 -- The visibility of the actuals may be different between the point of
5951 -- generic instantiation and the instantiation of the body.
5953 procedure Check_Generic_Actuals
5956 is
5961 -- For a formal that is an array type, the component type is often a
5962 -- previous formal in the same unit. The privacy status of the component
5963 -- type will have been examined earlier in the traversal of the
5964 -- corresponding actuals, and this status should not be modified for
5965 -- the array (sub)type itself. However, if the base type of the array
5966 -- (sub)type is private, its full view must be restored in the body to
5967 -- be consistent with subsequent index subtypes, etc.
5968 --
5969 -- To detect this case we have to rescan the list of formals, which is
5970 -- usually short enough to ignore the resulting inefficiency.
5972 -----------------------------
5973 -- Denotes_Previous_Actual --
5974 -----------------------------
5979 begin
5986 then
5992 else
6000 -- Start of processing for Check_Generic_Actuals
6002 begin
6009 then
6013 then
6015 else
6024 -- We constructed the generic actual type as a subtype of the
6025 -- supplied type. This means that it normally would not inherit
6026 -- subtype specific attributes of the actual, which is wrong for
6027 -- the generic case.
6033 -- This can happen when E is an itype that is the full view of
6034 -- a private type completed, e.g. with a constrained array. In
6035 -- that case, use the first subtype, which will carry size
6036 -- information. The base type itself is unconstrained and will
6037 -- not carry it.
6049 -- In nested instances, the base type of an access actual may
6050 -- itself be private, and need to be exchanged.
6054 then
6055 Check_Private_View
6061 -- If this is the renaming for the current instance, we're done.
6062 -- Otherwise it is a formal package. If the corresponding formal
6063 -- was declared with a box, the (instantiations of the) generic
6064 -- formal part are also visible. Otherwise, ignore the entity
6065 -- created to validate the actuals.
6073 -- The visibility of a formal of an enclosing generic is already
6074 -- correct.
6081 then
6085 else
6092 -- If this is a subprogram instance (in a wrapper package) the
6093 -- actual is fully visible.
6098 -- If the formal package is declared with a box, or if the formal
6099 -- parameter is defaulted, it is visible in the body.
6107 -- If the type of the actual is a private type declared in the
6108 -- enclosing scope of the generic unit, the body of the generic
6109 -- sees the full view of the type (because it has to appear in
6110 -- the corresponding package body). If the type is private now,
6111 -- exchange views to restore the proper visiblity in the instance.
6113 declare
6115 -- The type of the actual
6118 -- The generic unit
6121 -- The enclosing scope of the generic unit
6123 begin
6125 Gen_Id :=
6126 Generic_Parent
6127 (Specification
6128 (Unit_Declaration_Node
6130 else
6131 Gen_Id :=
6137 -- The exchange is only needed if the generic is defined
6138 -- within a package which is not a common ancestor of the
6139 -- scope of the instance, and is not already in scope.
6146 then
6149 -- If the type of the entity is a subtype, it may also have
6150 -- to be made visible, together with the base type of its
6151 -- full view, after exchange.
6165 ------------------------------
6166 -- Check_Generic_Child_Unit --
6167 ------------------------------
6169 procedure Check_Generic_Child_Unit
6172 is
6179 function Find_Generic_Child
6182 -- Search generic parent for possible child unit with the given name
6185 -- Within an instance of the parent, the child unit may be denoted by
6186 -- a simple name, or an abbreviated expanded name. Examine enclosing
6187 -- scopes to locate a possible parent instantiation.
6189 ------------------------
6190 -- Find_Generic_Child --
6191 ------------------------
6193 function Find_Generic_Child
6196 is
6199 begin
6200 -- If entity of name is already set, instance has already been
6201 -- resolved, e.g. in an enclosing instantiation.
6206 else
6210 else
6215 then
6218 then
6219 Error_Msg_NE
6234 ---------------------------
6235 -- In_Enclosing_Instance --
6236 ---------------------------
6242 begin
6243 -- We do not inline any call that contains instantiations, except
6244 -- for instantiations of Unchecked_Conversion, so if we are within
6245 -- an inlined body the current instance does not require parents.
6252 -- Loop to check enclosing scopes
6260 and then Present
6262 then
6263 -- Check whether the generic we are looking for is a child of
6264 -- this instance.
6266 E := Find_Generic_Child
6270 else
6279 -- Not a child unit
6284 else
6298 -- Start of processing for Check_Generic_Child_Unit
6300 begin
6301 -- If the name of the generic is given by a selected component, it may
6302 -- be the name of a generic child unit, and the prefix is the name of an
6303 -- instance of the parent, in which case the child unit must be visible.
6304 -- If this instance is not in scope, it must be placed there and removed
6305 -- after instantiation, because what is being instantiated is not the
6306 -- original child, but the corresponding child present in the instance
6307 -- of the parent.
6309 -- If the child is instantiated within the parent, it can be given by
6310 -- a simple name. In this case the instance is already in scope, but
6311 -- the child generic must be recovered from the generic parent as well.
6320 then
6329 and then
6331 then
6337 then
6338 -- A formal package may be a real child package, and not the
6339 -- implicit instance within a parent. In this case the child is
6340 -- not visible and has to be retrieved explicitly as well.
6347 -- The prefix denotes an instantiation. The entity itself may be a
6348 -- nested generic, or a child unit.
6359 -- Indicate that this is a reference to the parent
6365 -- A common mistake is to replicate the naming scheme of a
6366 -- hierarchy by instantiating a generic child directly, rather
6367 -- than the implicit child in a parent instance:
6369 -- generic .. package Gpar is ..
6370 -- generic .. package Gpar.Child is ..
6371 -- package Par is new Gpar ();
6373 -- with Gpar.Child;
6374 -- package Par.Child is new Gpar.Child ();
6375 -- rather than Par.Child
6377 -- In this case the instantiation is within Par, which is an
6378 -- instance, but Gpar does not denote Par because we are not IN
6379 -- the instance of Gpar, so this is illegal. The test below
6380 -- recognizes this particular case.
6386 N_Compilation_Unit)
6387 then
6388 Error_Msg_N
6390 Gen_Id);
6395 N_Generic_Renaming_Declaration
6396 then
6402 -- If the parent is already installed, install the actuals
6403 -- for its formal packages. This is necessary when the child
6404 -- instance is a child of the parent instance: in this case,
6405 -- the parent is placed on the scope stack but the formal
6406 -- packages are not made visible.
6411 else
6412 -- If the generic parent does not contain an entity that
6413 -- corresponds to the selector, the instance doesn't either.
6414 -- Analyzing the node will yield the appropriate error message.
6415 -- If the entity is not a child unit, then it is an inner
6416 -- generic in the parent.
6421 else
6425 and then
6428 then
6432 -- The generic unit may be the renaming of the implicit child
6433 -- present in an instance. In that case the parent instance is
6434 -- obtained from the name of the renamed entity.
6439 then
6440 declare
6443 begin
6455 -- Entity already present, analyze prefix, whose meaning may be
6456 -- an instance in the current context. If it is an instance of
6457 -- a relative within another, the proper parent may still have
6458 -- to be installed, if they are not of the same generation.
6462 -- In the unlikely case that a local declaration hides the name
6463 -- of the parent package, locate it on the homonym chain. If the
6464 -- context is an instance of the parent, the renaming entity is
6465 -- flagged as such.
6470 loop
6483 then
6490 -- The child unit is found in some enclosing scope
6494 else
6497 -- If this is the renaming of the implicit child in a parent
6498 -- instance, recover the parent name and install it.
6508 then
6518 -- If it is a child unit of a non-generic parent, it may be
6519 -- use-visible and given by a direct name. Install parent as
6520 -- for other cases.
6524 and then
6527 then
6537 -----------------------------
6538 -- Check_Hidden_Child_Unit --
6539 -----------------------------
6541 procedure Check_Hidden_Child_Unit
6545 is
6548 begin
6554 then
6556 Error_Msg_NE
6564 ------------------------
6565 -- Check_Private_View --
6566 ------------------------
6572 begin
6573 -- Exchange views if the type was not private in the generic but is
6574 -- private at the point of instantiation. Do not exchange views if
6575 -- the scope of the type is in scope. This can happen if both generic
6576 -- and instance are sibling units, or if type is defined in a parent.
6577 -- In this case the visibility of the type will be correct for all
6578 -- semantic checks.
6587 then
6588 -- In the generic, the full type was visible. Save the private
6589 -- entity, for subsequent exchange.
6597 then
6598 -- Only the private declaration was visible in the generic. If
6599 -- the type appears in a subtype declaration, the subtype in the
6600 -- instance must have a view compatible with that of its parent,
6601 -- which must be exchanged (see corresponding code in Restore_
6602 -- Private_Views). Otherwise, if the type is defined in a parent
6603 -- unit, leave full visibility within instance, which is safe.
6608 then
6613 then
6618 -- For composite types with inconsistent representation exchange
6619 -- component types accordingly.
6625 then
6632 then
6636 -- The normal exchange mechanism relies on the setting of a
6637 -- flag on the reference in the generic. However, an additional
6638 -- mechanism is needed for types that are not explicitly
6639 -- mentioned in the generic, but may be needed in expanded code
6640 -- in the instance. This includes component types of arrays and
6641 -- designated types of access types. This processing must also
6642 -- include the index types of arrays which we take care of here.
6644 declare
6648 begin
6655 then
6667 then
6670 -- Finally, a non-private subtype may have a private base type, which
6671 -- must be exchanged for consistency. This can happen when a package
6672 -- body is instantiated, when the scope stack is empty but in fact
6673 -- the subtype and the base type are declared in an enclosing scope.
6675 -- Note that in this case we introduce an inconsistency in the view
6676 -- set, because we switch the base type BT, but there could be some
6677 -- private dependent subtypes of BT which remain unswitched. Such
6678 -- subtypes might need to be switched at a later point (see specific
6679 -- provision for that case in Switch_View).
6687 then
6694 -----------------------------
6695 -- Check_Hidden_Primitives --
6696 -----------------------------
6703 begin
6708 -- Traverse the list of associations between formals and actuals
6709 -- searching for renamings of tagged types
6718 then
6719 -- Traverse the list of primitives of the actual types
6720 -- searching for hidden primitives that are visible in the
6721 -- corresponding generic formal; leave them visible and
6722 -- append them to Result to restore their decoration later.
6724 Install_Hidden_Primitives
6737 --------------------------
6738 -- Contains_Instance_Of --
6739 --------------------------
6741 function Contains_Instance_Of
6745 is
6749 begin
6752 -- Verify that there are no circular instantiations. We check whether
6753 -- the unit contains an instance of the current scope or some enclosing
6754 -- scope (in case one of the instances appears in a subunit). Longer
6755 -- circularities involving subunits might seem too pathological to
6756 -- consider, but they were not too pathological for the authors of
6757 -- DEC bc30vsq, so we loop over all enclosing scopes, and mark all
6758 -- enclosing generic scopes as containing an instance.
6760 loop
6761 -- Within a generic subprogram body, the scope is not generic, to
6762 -- allow for recursive subprograms. Use the declaration to determine
6763 -- whether this is a generic unit.
6768 N_Generic_Subprogram_Declaration)
6769 then
6775 Error_Msg_NE
6785 Error_Msg_NE
6794 -- Indicate that Inner is being instantiated within Scop
6801 else
6809 -----------------------
6810 -- Copy_Generic_Node --
6811 -----------------------
6813 function Copy_Generic_Node
6817 is
6822 -- Check the given value of one of the Fields referenced by the current
6823 -- node to determine whether to copy it recursively. The field may hold
6824 -- a Node_Id, a List_Id, or an Elist_Id, or a plain value (Sloc, Uint,
6825 -- Char) in which case it need not be copied.
6828 -- Common utility for various nodes
6831 -- Make copy of element list
6833 function Copy_Generic_List
6836 -- Apply Copy_Node recursively to the members of a node list
6839 -- True if an identifier is part of the defining program unit name of
6840 -- a child unit. The entity of such an identifier must be kept (for
6841 -- ASIS use) even though as the name of an enclosing generic it would
6842 -- otherwise not be preserved in the generic tree.
6844 ----------------------
6845 -- Copy_Descendants --
6846 ----------------------
6851 -- This code section is part of the implementation of an untyped
6852 -- tree traversal, so it needs direct access to node fields.
6854 begin
6862 -----------------------------
6863 -- Copy_Generic_Descendant --
6864 -----------------------------
6867 begin
6872 return Union_Id
6881 -- Nothing else is copyable (e.g. Uint values), return as is
6883 else
6888 ------------------------
6889 -- Copy_Generic_Elist --
6890 ------------------------
6896 begin
6901 Append_Elmt
6908 else
6913 -----------------------
6914 -- Copy_Generic_List --
6915 -----------------------
6917 function Copy_Generic_List
6920 is
6924 begin
6937 else
6942 ---------------------------
6943 -- In_Defining_Unit_Name --
6944 ---------------------------
6947 begin
6950 or else
6955 -- Start of processing for Copy_Generic_Node
6957 begin
6964 -- Copy aspects if present
6968 Set_Aspect_Specifications
6980 -- If defining identifier, then all fields have been copied already
6985 -- Special casing for identifiers and other entity names and operators
6988 N_Character_Literal,
6989 N_Expanded_Name,
6990 N_Operator_Symbol)
6992 then
6995 -- Link both nodes in order to assign subsequently the entity of
6996 -- the copy to the original node, in case this is a global
6997 -- reference.
7001 -- If we are within an instantiation, this is a nested generic
7002 -- that has already been analyzed at the point of definition.
7003 -- We must preserve references that were global to the enclosing
7004 -- parent at that point. Other occurrences, whether global or
7005 -- local to the current generic, must be resolved anew, so we
7006 -- reset the entity in the generic copy. A global reference has a
7007 -- smaller depth than the parent, or else the same depth in case
7008 -- both are distinct compilation units.
7010 -- A child unit is implicitly declared within the enclosing parent
7011 -- but is in fact global to it, and must be preserved.
7013 -- It is also possible for Current_Instantiated_Parent to be
7014 -- defined, and for this not to be a nested generic, namely if
7015 -- the unit is loaded through Rtsfind. In that case, the entity of
7016 -- New_N is only a link to the associated node, and not a defining
7017 -- occurrence.
7019 -- The entities for parent units in the defining_program_unit of a
7020 -- generic child unit are established when the context of the unit
7021 -- is first analyzed, before the generic copy is made. They are
7022 -- preserved in the copy for use in ASIS queries.
7030 then
7035 or else
7037 N_Defining_Character_Literal,
7038 N_Defining_Operator_Symbol)
7040 or else
7043 or else
7046 and then
7049 then
7053 -- Case of instantiating identifier or some other name or operator
7055 else
7056 -- If the associated node is still defined, the entity in it
7057 -- is global, and must be copied to the instance. If this copy
7058 -- is being made for a body to inline, it is applied to an
7059 -- instantiated tree, and the entity is already present and
7060 -- must be also preserved.
7062 declare
7065 begin
7071 -- The name in the call may be a selected component if the
7072 -- call has not been analyzed yet, as may be the case for
7073 -- pre/post conditions in a generic unit.
7077 then
7081 N_Defining_Character_Literal,
7082 N_Defining_Operator_Symbol)
7083 and then Expander_Active
7084 then
7085 -- Inlining case: we are copying a tree that contains
7086 -- global entities, which are preserved in the copy to be
7087 -- used for subsequent inlining.
7091 else
7098 -- For expanded name, we must copy the Prefix and Selector_Name
7101 Set_Prefix
7107 -- For operators, we must copy the right operand
7113 -- And for binary operators, the left operand as well
7121 -- Special casing for stubs
7125 -- In any case, we must copy the specification or defining
7126 -- identifier as appropriate.
7132 else
7134 Copy_Generic_Node
7138 -- If we are not instantiating, then this is where we load and
7139 -- analyze subunits, i.e. at the point where the stub occurs. A
7140 -- more permissive system might defer this analysis to the point
7141 -- of instantiation, but this seems too complicated for now.
7144 declare
7150 begin
7151 -- Make sure that, if it is a subunit of the main unit that is
7152 -- preprocessed and if -gnateG is specified, the preprocessed
7153 -- file will be written.
7157 Unum :=
7158 Load_Unit
7165 -- If the proper body is not found, a warning message will be
7166 -- emitted when analyzing the stub, or later at the point of
7167 -- instantiation. Here we just leave the stub as is.
7177 Error_Msg_N
7179 Subunit);
7185 -- We must create a generic copy of the subunit, in order to
7186 -- perform semantic analysis on it, and we must replace the
7187 -- stub in the original generic unit with the subunit, in order
7188 -- to preserve non-local references within.
7190 -- Only the proper body needs to be copied. Library_Unit and
7191 -- context clause are simply inherited by the generic copy.
7192 -- Note that the copy (which may be recursive if there are
7193 -- nested subunits) must be done first, before attaching it to
7194 -- the enclosing generic.
7196 New_Body :=
7197 Copy_Generic_Node
7201 -- Now place the original proper body in the original generic
7202 -- unit. This is a body, not a compilation unit.
7208 -- Finally replace the body of the subunit with its copy, and
7209 -- make this new subunit into the library unit of the generic
7210 -- copy, which does not have stubs any longer.
7217 -- If we are instantiating, this must be an error case, since
7218 -- otherwise we would have replaced the stub node by the proper body
7219 -- that corresponds. So just ignore it in the copy (i.e. we have
7220 -- copied it, and that is good enough).
7222 else
7228 -- If the node is a compilation unit, it is the subunit of a stub, which
7229 -- has been loaded already (see code below). In this case, the library
7230 -- unit field of N points to the parent unit (which is a compilation
7231 -- unit) and need not (and cannot) be copied.
7233 -- When the proper body of the stub is analyzed, the library_unit link
7234 -- is used to establish the proper context (see sem_ch10).
7236 -- The other fields of a compilation unit are copied as usual
7240 -- This code can only be executed when not instantiating, because in
7241 -- the copy made for an instantiation, the compilation unit node has
7242 -- disappeared at the point that a stub is replaced by its proper
7243 -- body.
7254 Copy_Generic_Node
7260 -- For an assignment node, the assignment is known to be semantically
7261 -- legal if we are instantiating the template. This avoids incorrect
7262 -- diagnostics in generated code.
7266 -- Copy name and expression fields in usual manner
7282 else
7285 then
7286 -- In the generic the aggregate has some composite type. If at
7287 -- the point of instantiation the type has a private view,
7288 -- install the full view (and that of its ancestors, if any).
7290 declare
7294 begin
7297 then
7304 then
7307 loop
7321 -- Do not copy the associated node, which points to the generic copy
7322 -- of the aggregate.
7324 declare
7326 -- This code section is part of the implementation of an untyped
7327 -- tree traversal, so it needs direct access to node fields.
7329 begin
7336 -- Allocators do not have an identifier denoting the access type, so we
7337 -- must locate it through the expression to check whether the views are
7338 -- consistent.
7343 and then Instantiating
7344 then
7345 declare
7350 begin
7353 -- Retrieve the allocator node in the generic copy
7358 then
7363 Copy_Descendants;
7366 -- For a proper body, we must catch the case of a proper body that
7367 -- replaces a stub. This represents the point at which a separate
7368 -- compilation unit, and hence template file, may be referenced, so we
7369 -- must make a new source instantiation entry for the template of the
7370 -- subunit, and ensure that all nodes in the subunit are adjusted using
7371 -- this new source instantiation entry.
7374 declare
7377 begin
7379 Create_Instantiation_Source
7383 S_Adjustment);
7386 -- Now copy the fields of the proper body, using the new
7387 -- adjustment factor if one was needed as per test above.
7389 Copy_Descendants;
7391 -- Restore the original adjustment factor in case changed
7396 -- Don't copy Ident or Comment pragmas, since the comment belongs to the
7397 -- generic unit, not to the instantiating unit.
7400 declare
7402 begin
7405 else
7406 Copy_Descendants;
7412 -- No descendant fields need traversing
7418 and then Instantiating
7419 then
7420 -- If the string is declared in an outer scope, the string_literal
7421 -- subtype created for it may have the wrong scope. We force the
7422 -- reanalysis of the constant to generate a new itype in the proper
7423 -- context.
7428 -- For the remaining nodes, copy their descendants recursively
7430 else
7431 Copy_Descendants;
7436 -- Should preserve Corresponding_Spec??? (12.3(14))
7443 ----------------------------
7444 -- Denotes_Formal_Package --
7445 ----------------------------
7447 function Denotes_Formal_Package
7451 is
7457 -- The package in question may be an actual for a previous formal
7458 -- package P of the current instance, so examine its actuals as well.
7459 -- This must be recursive over other formal packages.
7461 ----------------------------------
7462 -- Is_Actual_Of_Previous_Formal --
7463 ----------------------------------
7468 begin
7473 then
7491 -- Start of processing for Denotes_Formal_Package
7493 begin
7495 Par :=
7496 Instance_Envs.Table
7498 else
7504 N_Generic_Subprogram_Declaration
7505 then
7509 N_Formal_Package_Declaration
7510 then
7516 else
7517 -- Check whether this package is associated with a formal package of
7518 -- the enclosing instantiation. Iterate over the list of renamings.
7524 then
7545 -----------------
7546 -- End_Generic --
7547 -----------------
7550 begin
7551 -- ??? More things could be factored out in this routine. Should
7552 -- probably be done at a later stage.
7557 Expander_Mode_Restore;
7560 -------------
7561 -- Earlier --
7562 -------------
7566 -- Find distance from given node to enclosing compilation unit
7568 ----------------
7569 -- Find_Depth --
7570 ----------------
7573 begin
7576 loop
7582 -- Local declarations
7591 -- Start of processing for Earlier
7593 begin
7599 else
7614 -- At this point P1 and P2 are at the same distance from the root.
7615 -- We examine their parents until we find a common declarative list.
7616 -- If we reach the root, N1 and N2 do not descend from the same
7617 -- declarative list (e.g. one is nested in the declarative part and
7618 -- the other is in a block in the statement part) and the earlier
7619 -- one is already frozen.
7624 loop
7641 -- Expanded code usually shares the source location of the original
7642 -- construct it was generated for. This however may not necessarely
7643 -- reflect the true location of the code within the tree.
7645 -- Before comparing the slocs of the two nodes, make sure that we are
7646 -- working with correct source locations. Assume that P1 is to the left
7647 -- of P2. If either one does not come from source, traverse the common
7648 -- list heading towards the other node and locate the first source
7649 -- statement.
7651 -- P1 P2
7652 -- ----+===+===+--------------+===+===+----
7653 -- expanded code expanded code
7658 -- Neither P2 nor a source statement were located during the
7659 -- search. If we reach the end of the list, then P1 does not
7660 -- occur earlier than P2.
7662 -- ---->
7663 -- start --- P2 ----- P1 --- end
7668 -- We encounter P2 while going to the right of the list. This
7669 -- means that P1 does indeed appear earlier.
7671 -- ---->
7672 -- start --- P1 ===== P2 --- end
7673 -- expanded code in between
7678 -- No need to look any further since we have located a source
7679 -- statement.
7685 -- Keep going right
7694 -- Neither P1 nor a source statement were located during the
7695 -- search. If we reach the start of the list, then P1 does not
7696 -- occur earlier than P2.
7698 -- <----
7699 -- start --- P2 --- P1 --- end
7704 -- We encounter P1 while going to the left of the list. This
7705 -- means that P1 does indeed appear earlier.
7707 -- <----
7708 -- start --- P1 ===== P2 --- end
7709 -- expanded code in between
7714 -- No need to look any further since we have located a source
7715 -- statement.
7721 -- Keep going left
7727 -- At this point either both nodes came from source or we approximated
7728 -- their source locations through neighbouring source statements.
7733 -- When two nodes come from the same instance, they have identical top
7734 -- level locations. To determine proper relation within the tree, check
7735 -- their locations within the template.
7740 -- The two nodes either come from unrelated instances or do not come
7741 -- from instantiated code at all.
7743 else
7748 ----------------------
7749 -- Find_Actual_Type --
7750 ----------------------
7752 function Find_Actual_Type
7755 is
7759 begin
7760 -- Special processing only applies to child units
7765 -- If designated or component type is itself a formal of the child unit,
7766 -- its instance is available.
7771 -- If the array or access type is not declared in the parent unit,
7772 -- no special processing needed.
7776 then
7779 -- Otherwise, retrieve designated or component type by visibility
7781 else
7798 ----------------------------
7799 -- Freeze_Subprogram_Body --
7800 ----------------------------
7802 procedure Freeze_Subprogram_Body
7806 is
7815 -- Find innermost package body that encloses the given node, and which
7816 -- is not a compilation unit. Freeze nodes for the instance, or for its
7817 -- enclosing body, may be inserted after the enclosing_body of the
7818 -- generic unit. Used to determine proper placement of freeze node for
7819 -- both package and subprogram instances.
7822 -- Find entity for given package body, and locate or create a freeze
7823 -- node for it.
7825 ----------------------------
7826 -- Enclosing_Package_Body --
7827 ----------------------------
7832 begin
7836 loop
7840 else
7851 -------------------------
7852 -- Package_Freeze_Node --
7853 -------------------------
7858 begin
7869 -- Start of processing of Freeze_Subprogram_Body
7871 begin
7872 -- If the instance and the generic body appear within the same unit, and
7873 -- the instance precedes the generic, the freeze node for the instance
7874 -- must appear after that of the generic. If the generic is nested
7875 -- within another instance I2, then current instance must be frozen
7876 -- after I2. In both cases, the freeze nodes are those of enclosing
7877 -- packages. Otherwise, the freeze node is placed at the end of the
7878 -- current declarative part.
7888 then
7889 -- The parent was a premature instantiation. Insert freeze node at
7890 -- the end the current declarative part.
7895 -- Handle the following case:
7896 --
7897 -- package Parent_Inst is new ...
7898 -- Parent_Inst []
7899 --
7900 -- procedure P ... -- this body freezes Parent_Inst
7901 --
7902 -- package Inst is new ...
7903 --
7904 -- In this particular scenario, the freeze node for Inst must be
7905 -- inserted in the same manner as that of Parent_Inst - before the
7906 -- next source body or at the end of the declarative list (body not
7907 -- available). If body P did not exist and Parent_Inst was frozen
7908 -- after Inst, either by a body following Inst or at the end of the
7909 -- declarative region, the freeze node for Inst must be inserted
7910 -- after that of Parent_Inst. This relation is established by
7911 -- comparing the Slocs of Parent_Inst freeze node and Inst.
7916 then
7919 else
7923 -- The body enclosing the instance should be frozen after the body that
7924 -- includes the generic, because the body of the instance may make
7925 -- references to entities therein. If the two are not in the same
7926 -- declarative part, or if the one enclosing the instance is frozen
7927 -- already, freeze the instance at the end of the current declarative
7928 -- part.
7933 then
7935 or else
7937 and then
7939 then
7940 -- The enclosing package may contain several instances. Rather
7941 -- than computing the earliest point at which to insert its freeze
7942 -- node, we place it at the end of the declarative part of the
7943 -- parent of the generic.
7945 Insert_Freeze_Node_For_Instance
7955 then
7959 E_G_Id :=
7963 -- Freeze package that encloses instance, and place node after the
7964 -- package that encloses generic. If enclosing package is already
7965 -- frozen we have to assume it is at the proper place. This may be a
7966 -- potential ABE that requires dynamic checking. Do not add a freeze
7967 -- node if the package that encloses the generic is inside the body
7968 -- that encloses the instance, because the freeze node would be in
7969 -- the wrong scope. Additional contortions needed if the bodies are
7970 -- within a subunit.
7972 declare
7975 begin
7978 else
7983 Insert_Freeze_Node_For_Instance
7988 -- Freeze enclosing subunit before instance
7998 else
7999 -- If none of the above, insert freeze node at the end of the current
8000 -- declarative part.
8006 ----------------
8007 -- Get_Gen_Id --
8008 ----------------
8011 begin
8015 ---------------------
8016 -- Get_Instance_Of --
8017 ---------------------
8022 begin
8025 else
8026 -- On exit, entity is not instantiated: not a generic parameter, or
8027 -- else parameter of an inner generic unit.
8033 ------------------------------------
8034 -- Get_Package_Instantiation_Node --
8035 ------------------------------------
8041 begin
8042 -- If the Package_Instantiation attribute has been set on the package
8043 -- entity, then use it directly when it (or its Original_Node) refers
8044 -- to an N_Package_Instantiation node. In principle it should be
8045 -- possible to have this field set in all cases, which should be
8046 -- investigated, and would allow this function to be significantly
8047 -- simplified. ???
8060 -- If the instantiation is a compilation unit that does not need body
8061 -- then the instantiation node has been rewritten as a package
8062 -- declaration for the instance, and we return the original node.
8064 -- If it is a compilation unit and the instance node has not been
8065 -- rewritten, then it is still the unit of the compilation. Finally, if
8066 -- a body is present, this is a parent of the main unit whose body has
8067 -- been compiled for inlining purposes, and the instantiation node has
8068 -- been rewritten with the instance body.
8070 -- Otherwise the instantiation node appears after the declaration. If
8071 -- the entity is a formal package, the declaration may have been
8072 -- rewritten as a generic declaration (in the case of a formal with box)
8073 -- or left as a formal package declaration if it has actuals, and is
8074 -- found with a forward search.
8079 then
8085 else
8091 then
8094 else
8097 N_Formal_Package_Declaration)
8098 loop
8106 ------------------------
8107 -- Has_Been_Exchanged --
8108 ------------------------
8113 begin
8126 ----------
8127 -- Hash --
8128 ----------
8131 begin
8135 ------------------------
8136 -- Hide_Current_Scope --
8137 ------------------------
8143 begin
8156 -- Make the scope name invisible as well. This is necessary, but might
8157 -- conflict with calls to Rtsfind later on, in case the scope is a
8158 -- predefined one. There is no clean solution to this problem, so for
8159 -- now we depend on the user not redefining Standard itself in one of
8160 -- the parent units.
8169 --------------
8170 -- Init_Env --
8171 --------------
8176 begin
8184 -- Save configuration switches. These may be reset if the unit is a
8185 -- predefined unit, and the current mode is not Ada 2005.
8194 -- Make dummy entry for Instantiated parent. If generic unit is legal,
8195 -- this is set properly in Set_Instance_Env.
8197 Current_Instantiated_Parent :=
8201 ------------------------------
8202 -- In_Same_Declarative_Part --
8203 ------------------------------
8205 function In_Same_Declarative_Part
8208 is
8212 begin
8218 N_Package_Body,
8219 N_Package_Declaration,
8220 N_Task_Body,
8221 N_Protected_Body,
8222 N_Block_Statement)
8223 then
8232 else
8240 ---------------------
8241 -- In_Main_Context --
8242 ---------------------
8249 begin
8253 then
8264 -- If the current scope is part of the context of the main unit,
8265 -- analysis of the corresponding with_clause is not complete, and
8266 -- the entity is not set. We use the Chars field directly, which
8267 -- might produce false positives in rare cases, but guarantees
8268 -- that we produce all the instance bodies we will need.
8273 then
8284 ---------------------
8285 -- Inherit_Context --
8286 ---------------------
8298 begin
8301 -- The inherited context is attached to the enclosing compilation
8302 -- unit. This is either the main unit, or the declaration for the
8303 -- main unit (in case the instantiation appears within the package
8304 -- declaration and the main unit is its body).
8309 loop
8320 -- Take care to prevent direct cyclic with's
8324 -- Do not add a unit if it is already in the context
8331 then
8353 ----------------
8354 -- Initialize --
8355 ----------------
8358 begin
8368 -------------------------------------
8369 -- Insert_Freeze_Node_For_Instance --
8370 -------------------------------------
8372 procedure Insert_Freeze_Node_For_Instance
8375 is
8382 -- Find enclosing package or subprogram body, if any. Freeze node may
8383 -- be placed at end of current declarative list if previous instance
8384 -- and current one have different enclosing bodies.
8387 -- Find the local instance, if any, that declares the generic that is
8388 -- being instantiated. If present, the freeze node for this instance
8389 -- must follow the freeze node for the previous instance.
8391 --------------------
8392 -- Enclosing_Body --
8393 --------------------
8398 begin
8402 loop
8406 else
8417 -----------------------
8418 -- Previous_Instance --
8419 -----------------------
8424 begin
8428 loop
8431 then
8441 -- Start of processing for Insert_Freeze_Node_For_Instance
8443 begin
8450 -- When processing a subprogram instantiation, utilize the actual
8451 -- subprogram instantiation rather than its package wrapper as it
8452 -- carries all the context information.
8458 -- If this is a package instance, check whether the generic is
8459 -- declared in a previous instance and the current instance is
8460 -- not within the previous one.
8464 then
8465 declare
8468 Previous_Instance
8472 begin
8475 then
8478 -- If the current instance is within the one that contains
8479 -- the generic, the freeze node for the current one must
8480 -- appear in the current declarative part. Ditto, if the
8481 -- current instance is within another package instance or
8482 -- within a body that does not enclose the current instance.
8483 -- In these three cases the freeze node of the previous
8484 -- instance is not relevant.
8488 loop
8490 or else
8496 -- Previous instance encloses current instance
8501 -- If the next node is a source body we must freeze in
8502 -- the current scope as well.
8508 then
8511 -- Current instance is within an unrelated instance
8516 -- Current instance is within an unrelated body
8520 then
8523 else
8531 -- When the instantiation occurs in a package declaration, append the
8532 -- freeze node to the private declarations (if any).
8538 then
8543 -- Determine the proper freeze point of a package instantiation. We
8544 -- adhere to the general rule of a package or subprogram body causing
8545 -- freezing of anything before it in the same declarative region. In
8546 -- this case, the proper freeze point of a package instantiation is
8547 -- before the first source body which follows, or before a stub. This
8548 -- ensures that entities coming from the instance are already frozen
8549 -- and usable in source bodies.
8554 and then
8556 then
8559 or else
8562 then
8571 -- In a package declaration, or if no previous body, insert at end
8572 -- of list.
8579 ------------------
8580 -- Install_Body --
8581 ------------------
8583 procedure Install_Body
8588 is
8602 -- Check whether instance and generic body are within same subprogram.
8605 -- If the instance is nested inside a generic unit, the Sloc of the
8606 -- instance indicates the place of the original definition, not the
8607 -- point of the current enclosing instance. Pending a better usage of
8608 -- Slocs to indicate instantiation places, we determine the place of
8609 -- origin of a node by finding the maximum sloc of any ancestor node.
8610 -- Why is this not equivalent to Top_Level_Location ???
8612 ----------------------------
8613 -- In_Same_Enclosing_Subp --
8614 ----------------------------
8620 begin
8624 loop
8630 else
8638 else
8646 ---------------
8647 -- True_Sloc --
8648 ---------------
8654 begin
8668 -- Start of processing for Install_Body
8670 begin
8671 -- If the body is a subunit, the freeze point is the corresponding stub
8672 -- in the current compilation, not the subunit itself.
8676 else
8682 -- If the instantiation and the generic definition appear in the same
8683 -- package declaration, this is an early instantiation. If they appear
8684 -- in the same declarative part, it is an early instantiation only if
8685 -- the generic body appears textually later, and the generic body is
8686 -- also in the main unit.
8688 -- If instance is nested within a subprogram, and the generic body
8689 -- is not, the instance is delayed because the enclosing body is. If
8690 -- instance and body are within the same scope, or the same subprogram
8691 -- body, indicate explicitly that the instance is delayed.
8693 Must_Delay :=
8696 N_Generic_Package_Declaration)
8703 -- If this is an early instantiation, the freeze node is placed after
8704 -- the generic body. Otherwise, if the generic appears in an instance,
8705 -- we cannot freeze the current instance until the outer one is frozen.
8706 -- This is only relevant if the current instance is nested within some
8707 -- inner scope not itself within the outer instance. If this scope is
8708 -- a package body in the same declarative part as the outer instance,
8709 -- then that body needs to be frozen after the outer instance. Finally,
8710 -- if no delay is needed, we place the freeze node at the end of the
8711 -- current declarative part.
8723 then
8724 -- Freeze instance of inner generic after instance of enclosing
8725 -- generic.
8729 -- Handle the following case:
8731 -- package Parent_Inst is new ...
8732 -- Parent_Inst []
8734 -- procedure P ... -- this body freezes Parent_Inst
8736 -- package Inst is new ...
8738 -- In this particular scenario, the freeze node for Inst must
8739 -- be inserted in the same manner as that of Parent_Inst,
8740 -- before the next source body or at the end of the declarative
8741 -- list (body not available). If body P did not exist and
8742 -- Parent_Inst was frozen after Inst, either by a body
8743 -- following Inst or at the end of the declarative region,
8744 -- the freeze node for Inst must be inserted after that of
8745 -- Parent_Inst. This relation is established by comparing
8746 -- the Slocs of Parent_Inst freeze node and Inst.
8751 then
8753 else
8757 -- Freeze package enclosing instance of inner generic after
8758 -- instance of enclosing generic.
8762 then
8763 declare
8766 begin
8778 -- The enclosing context is a subunit, insert the freeze
8779 -- node after the stub.
8782 Insert_Freeze_Node_For_Instance
8786 -- The enclosing context is a package with a stub body
8787 -- which has already been replaced by the real body.
8788 -- Insert the freeze node after the actual body.
8792 and then Was_Originally_Stub
8794 then
8795 Insert_Freeze_Node_For_Instance
8799 -- The parent instance has been frozen before the body of
8800 -- the enclosing package, insert the freeze node after
8801 -- the body.
8806 then
8807 Insert_Freeze_Node_For_Instance
8810 else
8811 Insert_After
8817 else
8821 else
8831 -----------------------------
8832 -- Install_Formal_Packages --
8833 -----------------------------
8840 begin
8843 -- If we are installing an instance parent, locate the formal packages
8844 -- of its generic parent.
8854 then
8855 -- If this is the renaming for the parent instance, done
8860 -- The visibility of a formal of an enclosing generic is already
8861 -- correct.
8870 -- Find formal package in generic unit that corresponds to
8871 -- (instance of) formal package in instance.
8890 --------------------
8891 -- Install_Parent --
8892 --------------------
8905 -- Install the scopes of noninstance parent units ending with Par
8908 -- The child unit is within the declarative part of the parent, so the
8909 -- declarations within the parent are immediately visible.
8911 -------------------------------
8912 -- Install_Noninstance_Specs --
8913 -------------------------------
8916 begin
8920 then
8926 ------------------
8927 -- Install_Spec --
8928 ------------------
8933 begin
8934 -- If this parent of the child instance is a top-level unit,
8935 -- then record the unit and its visibility for later resetting in
8936 -- Remove_Parent. We exclude units that are generic instances, as we
8937 -- only want to record this information for the ultimate top-level
8938 -- noninstance parent (is that always correct???).
8942 then
8947 -- Open the parent scope and make it and its declarations visible.
8948 -- If this point is not within a body, then only the visible
8949 -- declarations should be made visible, and installation of the
8950 -- private declarations is deferred until the appropriate point
8951 -- within analysis of the spec being instantiated (see the handling
8952 -- of parent visibility in Analyze_Package_Specification). This is
8953 -- relaxed in the case where the parent unit is Ada.Tags, to avoid
8954 -- private view problems that occur when compiling instantiations of
8955 -- a generic child of that package (Generic_Dispatching_Constructor).
8956 -- If the instance freezes a tagged type, inlinings of operations
8957 -- from Ada.Tags may need the full view of type Tag. If inlining took
8958 -- proper account of establishing visibility of inlined subprograms'
8959 -- parents then it should be possible to remove this
8960 -- special check. ???
8973 -- Start of processing for Install_Parent
8975 begin
8976 -- We need to install the parent instance to compile the instantiation
8977 -- of the child, but the child instance must appear in the current
8978 -- scope. Given that we cannot place the parent above the current scope
8979 -- in the scope stack, we duplicate the current scope and unstack both
8980 -- after the instantiation is complete.
8982 -- If the parent is itself the instantiation of a child unit, we must
8983 -- also stack the instantiation of its parent, and so on. Each such
8984 -- ancestor is the prefix of the name in a prior instantiation.
8986 -- If this is a nested instance, the parent unit itself resolves to
8987 -- a renaming of the parent instance, whose declaration we need.
8989 -- Finally, the parent may be a generic (not an instance) when the
8990 -- child unit appears as a formal package.
9006 loop
9007 -- Load grandparent instance as well
9023 else
9024 -- Parent is not the name of an instantiation
9030 else
9031 -- Previous error
9039 else
9057 -------------------------------
9058 -- Install_Hidden_Primitives --
9059 -------------------------------
9061 procedure Install_Hidden_Primitives
9065 is
9073 begin
9074 -- No action needed in case of serious errors because we cannot trust
9075 -- in the order of primitives
9080 -- No action possible if we don't have available the list of primitive
9081 -- operations
9088 then
9091 -- There is no need to handle interface types since their primitives
9092 -- cannot be hidden
9102 else
9106 loop
9107 -- Skip predefined primitives in the generic formal
9111 loop
9115 -- Skip predefined primitives in the generic actual
9119 loop
9128 -- There is no need to handle interface primitives because their
9129 -- primitives are not hidden
9133 -- Here we install one hidden primitive
9138 then
9147 -- Append the elements to the list of temporarily visible primitives
9148 -- avoiding duplicates.
9163 -------------------------------
9164 -- Restore_Hidden_Primitives --
9165 -------------------------------
9171 begin
9184 --------------------------------
9185 -- Instantiate_Formal_Package --
9186 --------------------------------
9188 function Instantiate_Formal_Package
9192 is
9201 procedure Find_Matching_Actual
9204 -- We need to associate each formal entity in the formal package with
9205 -- the corresponding entity in the actual package. The actual package
9206 -- has been analyzed and possibly expanded, and as a result there is
9207 -- no one-to-one correspondence between the two lists (for example,
9208 -- the actual may include subtypes, itypes, and inherited primitive
9209 -- operations, interspersed among the renaming declarations for the
9210 -- actuals) . We retrieve the corresponding actual by name because each
9211 -- actual has the same name as the formal, and they do appear in the
9212 -- same order.
9215 -- Retrieve entity of defining entity of generic formal parameter.
9216 -- Only the declarations of formals need to be considered when
9217 -- linking them to actuals, but the declarative list may include
9218 -- internal entities generated during analysis, and those are ignored.
9220 procedure Match_Formal_Entity
9224 -- Associates the formal entity with the actual. In the case where
9225 -- Formal_Ent is a formal package, this procedure iterates through all
9226 -- of its formals and enters associations between the actuals occurring
9227 -- in the formal package's corresponding actual package (given by
9228 -- Actual_Ent) and the formal package's formal parameters. This
9229 -- procedure recurses if any of the parameters is itself a package.
9231 function Is_Instance_Of
9234 -- The actual can be an instantiation of a generic within another
9235 -- instance, in which case there is no direct link from it to the
9236 -- original generic ancestor. In that case, we recognize that the
9237 -- ultimate ancestor is the same by examining names and scopes.
9240 -- If the current formal is declared with a box, its own formals are
9241 -- visible in the instance, as they were in the generic, and their
9242 -- Hidden flag must be reset. If some of these formals are themselves
9243 -- packages declared with a box, the processing must be recursive.
9245 --------------------------
9246 -- Find_Matching_Actual --
9247 --------------------------
9249 procedure Find_Matching_Actual
9252 is
9255 begin
9257 when N_Formal_Object_Declaration |
9258 N_Formal_Type_Declaration =>
9265 when N_Formal_Subprogram_Declaration |
9266 N_Formal_Package_Declaration |
9267 N_Package_Declaration |
9268 N_Generic_Package_Declaration =>
9280 -------------------------
9281 -- Match_Formal_Entity --
9282 -------------------------
9284 procedure Match_Formal_Entity
9288 is
9291 begin
9296 -- Record associations for each parameter
9300 declare
9309 begin
9310 -- Retrieve the actual given in the formal package declaration
9314 -- The actual in the formal package declaration may be a
9315 -- renamed generic package, in which case we want to retrieve
9316 -- the original generic in order to traverse its formal part.
9320 else
9328 else
9335 loop
9340 -- This is a formal of the original package. Record
9341 -- association and recurse.
9354 -----------------------
9355 -- Get_Formal_Entity --
9356 -----------------------
9360 begin
9377 -- All other declarations are introduced by semantic analysis and
9378 -- have no match in the actual.
9385 --------------------
9386 -- Is_Instance_Of --
9387 --------------------
9389 function Is_Instance_Of
9392 is
9395 begin
9399 -- Simplest case: the generic parent of the actual is the formal
9407 -- The actual may be obtained through several instantiations. Its
9408 -- scope must itself be an instance of a generic declared in the
9409 -- same scope as the formal. Any other case is detected above.
9414 else
9419 ---------------------------
9420 -- Process_Nested_Formal --
9421 ---------------------------
9426 begin
9429 then
9434 Set_Is_Potentially_Use_Visible
9447 -- Start of processing for Instantiate_Formal_Package
9449 begin
9454 then
9455 Error_Msg_N
9460 else
9464 -- The actual may be a renamed package, or an outer generic formal
9465 -- package whose instantiation is converted into a renaming.
9474 else
9475 Gen_Parent :=
9477 Formal_Pack :=
9483 else
9488 Error_Msg_N
9492 elsif
9494 then
9497 else
9498 Error_Msg_NE
9506 Nod :=
9515 -- If the formal F has a box, then the generic declarations are
9516 -- visible in the generic G. In an instance of G, the corresponding
9517 -- entities in the actual for F (which are the actuals for the
9518 -- instantiation of the generic that F denotes) must also be made
9519 -- visible for analysis of the current instance. On exit from the
9520 -- current instance, those entities are made private again. If the
9521 -- actual is currently in use, these entities are also use-visible.
9523 -- The loop through the actual entities also steps through the formal
9524 -- entities and enters associations from formals to actuals into the
9525 -- renaming map. This is necessary to properly handle checking of
9526 -- actual parameter associations for later formals that depend on
9527 -- actuals declared in the formal package.
9529 -- In Ada 2005, partial parameterization requires that we make
9530 -- visible the actuals corresponding to formals that were defaulted
9531 -- in the formal package. There formals are identified because they
9532 -- remain formal generics within the formal package, rather than
9533 -- being renamings of the actuals supplied.
9535 declare
9546 begin
9549 else
9554 Actual_Of_Formal :=
9558 loop
9564 Match_Formal_Entity
9567 -- We iterate at the same time over the actuals of the
9568 -- local package created for the formal, to determine
9569 -- which one of the formals of the original generic were
9570 -- defaulted in the formal. The corresponding actual
9571 -- entities are visible in the enclosing instance.
9574 or else
9576 and then
9577 Is_Generic_Formal
9579 then
9582 Set_Is_Potentially_Use_Visible
9589 else
9598 else
9599 -- No further formals to match, but the generic part may
9600 -- contain inherited operation that are not hidden in the
9601 -- enclosing instance.
9607 -- Inherited subprograms generated by formal derived types are
9608 -- also visible if the types are.
9613 loop
9615 and then
9617 and then
9619 then
9621 Set_Is_Potentially_Use_Visible
9629 -- If the formal is not declared with a box, reanalyze it as an
9630 -- abbreviated instantiation, to verify the matching rules of 12.7.
9631 -- The actual checks are performed after the generic associations
9632 -- have been analyzed, to guarantee the same visibility for this
9633 -- instantiation and for the actuals.
9635 -- In Ada 2005, the generic associations for the formal can include
9636 -- defaulted parameters. These are ignored during check. This
9637 -- internal instantiation is removed from the tree after conformance
9638 -- checking, because it contains formal declarations for those
9639 -- defaulted parameters, and those should not reach the back-end.
9642 declare
9646 begin
9652 Name =>
9653 New_Occurrence_Of
9655 Generic_Associations =>
9664 -----------------------------------
9665 -- Instantiate_Formal_Subprogram --
9666 -----------------------------------
9668 function Instantiate_Formal_Subprogram
9672 is
9679 -- If the generic is a child unit, the parent has been installed on the
9680 -- scope stack, but a default subprogram cannot resolve to something
9681 -- on the parent because that parent is not really part of the visible
9682 -- context (it is there to resolve explicit local entities). If the
9683 -- default has resolved in this way, we remove the entity from immediate
9684 -- visibility and analyze the node again to emit an error message or
9685 -- find another visible candidate.
9688 -- Perform legality check and raise exception on failure
9690 -----------------------
9691 -- From_Parent_Scope --
9692 -----------------------
9697 begin
9710 -----------------------------
9711 -- Valid_Actual_Subprogram --
9712 -----------------------------
9717 begin
9723 then
9726 else
9732 N_Indexed_Component,
9733 N_Character_Literal,
9734 N_Explicit_Dereference)
9735 then
9739 Error_Msg_NE
9745 -- Local variables
9752 -- Start of processing for Instantiate_Formal_Subprogram
9754 begin
9757 -- The tree copy has created the proper instantiation sloc for the
9758 -- new specification. Use this location for all other constructed
9759 -- declarations.
9763 -- Create new entity for the actual (New_Copy_Tree does not), and
9764 -- indicate that it is an actual.
9766 Set_Defining_Unit_Name
9771 -- Create new entities for the each of the formals in the specification
9772 -- of the renaming declaration built for the actual.
9775 declare
9779 begin
9791 -- Find entity of actual. If the actual is an attribute reference, it
9792 -- cannot be resolved here (its formal is missing) but is handled
9793 -- instead in Attribute_Renaming. If the actual is overloaded, it is
9794 -- fully resolved subsequently, when the renaming declaration for the
9795 -- formal is analyzed. If it is an explicit dereference, resolve the
9796 -- prefix but not the actual itself, to prevent interpretation as call.
9817 N_Selected_Component,
9818 N_Indexed_Component,
9819 N_Character_Literal)
9821 then
9823 else
9830 -- Actual is resolved at the point of instantiation. Create an
9831 -- identifier or operator with the same name as the formal.
9834 Nam :=
9838 else
9844 then
9845 -- Generate null body for procedure, for use in the instance
9847 Decl_Node :=
9851 Handled_Statement_Sequence =>
9858 else
9860 Error_Msg_NE
9862 Error_Msg_NE
9868 Decl_Node :=
9873 -- If we do not have an actual and the formal specified <> then set to
9874 -- get proper default.
9880 -- Gather possible interpretations for the actual before analyzing the
9881 -- instance. If overloaded, it will be resolved when analyzing the
9882 -- renaming declaration.
9889 then
9900 else
9901 declare
9905 begin
9919 -- The generic instantiation freezes the actual. This can only be done
9920 -- once the actual is resolved, in the analysis of the renaming
9921 -- declaration. To make the formal subprogram entity available, we set
9922 -- Corresponding_Formal_Spec to point to the formal subprogram entity.
9923 -- This is also needed in Analyze_Subprogram_Renaming for the processing
9924 -- of formal abstract subprograms.
9928 -- We cannot analyze the renaming declaration, and thus find the actual,
9929 -- until all the actuals are assembled in the instance. For subsequent
9930 -- checks of other actuals, indicate the node that will hold the
9931 -- instance of this formal.
9938 then
9939 -- The renaming declaration will create a body, which must appear
9940 -- outside of the instantiation, We move the renaming declaration
9941 -- out of the instance, and create an additional renaming inside,
9942 -- to prevent freezing anomalies.
9944 declare
9947 begin
9952 -- Now create renaming within the instance
9954 Decl_Node :=
9967 ------------------------
9968 -- Instantiate_Object --
9969 ------------------------
9971 function Instantiate_Object
9975 is
9991 begin
9994 else
9999 -- Sloc for error message on missing actual
10009 -- OUT present
10013 -- An IN OUT generic actual must be a name. The instantiation is a
10014 -- renaming declaration. The actual is the name being renamed. We
10015 -- use the actual directly, rather than a copy, because it is not
10016 -- used further in the list of actuals, and because a copy or a use
10017 -- of relocate_node is incorrect if the instance is nested within a
10018 -- generic. In order to simplify ASIS searches, the Generic_Parent
10019 -- field links the declaration to the generic association.
10022 Error_Msg_NE
10025 Error_Msg_NE
10032 Decl_Node :=
10039 Decl_Node :=
10048 -- The analysis of the actual may produce Insert_Action nodes, so
10049 -- the declaration must have a context in which to attach them.
10054 -- Return if the analysis of the actual reported some error
10060 -- This check is performed here because Analyze_Object_Renaming will
10061 -- not check it when Comes_From_Source is False. Note though that the
10062 -- check for the actual being the name of an object will be performed
10063 -- in Analyze_Object_Renaming.
10067 then
10068 Error_Msg_N
10070 Actual);
10073 -- The actual has to be resolved in order to check that it is a
10074 -- variable (due to cases such as F (1), where F returns access to
10075 -- an array, and for overloaded prefixes).
10079 -- If the type of the formal is not itself a formal, and the current
10080 -- unit is a child unit, the formal type must be declared in a
10081 -- parent, and must be retrieved by visibility.
10086 then
10087 declare
10090 begin
10101 then
10102 -- If the actual has the type of the full view of the formal, or
10103 -- else a non-private subtype of the formal, then the visibility
10104 -- of the formal type has changed. Add to the actuals a subtype
10105 -- declaration that will force the exchange of views in the body
10106 -- of the instance as well.
10108 Subt_Decl :=
10122 Error_Msg_NE
10127 -- Ada 2005 (AI-423): For a generic formal object of mode in out,
10128 -- the type of the actual shall resolve to a specific anonymous
10129 -- access type.
10133 E_Anonymous_Access_Type
10135 E_Anonymous_Access_Type
10136 then
10137 Error_Msg_NE
10144 -- Check for instantiation of atomic/volatile actual for
10145 -- non-atomic/volatile formal (RM C.6 (12)).
10148 Error_Msg_N
10153 then
10154 Error_Msg_N
10159 -- Formal in-parameter
10161 else
10162 -- The instantiation of a generic formal in-parameter is constant
10163 -- declaration. The actual is the expression for that declaration.
10172 Decl_Node :=
10182 -- A generic formal object of a tagged type is defined to be
10183 -- aliased so the new constant must also be treated as aliased.
10191 -- No need to repeat (pre-)analysis of some expression nodes
10192 -- already handled in Preanalyze_Actuals.
10197 -- Return if the analysis of the actual reported some error
10204 declare
10208 begin
10213 -- If the actual is an aggregate, perform name resolution on
10214 -- its components (the analysis of an aggregate does not do it)
10215 -- to capture local names that may be hidden if the generic is
10216 -- a child unit.
10224 then
10225 Error_Msg_N
10233 -- Use default to construct declaration
10241 Decl_Node :=
10247 Expression => New_Copy_Tree
10253 else
10254 Error_Msg_NE
10262 -- Create dummy constant declaration so that instance can be
10263 -- analyzed, to minimize cascaded visibility errors.
10271 Decl_Node :=
10277 Expression =>
10284 else
10294 -- Ada 2005 (AI-423): For a formal object declaration with a null
10295 -- exclusion or an access definition that has a null exclusion: If the
10296 -- actual matching the formal object declaration denotes a generic
10297 -- formal object of another generic unit G, and the instantiation
10298 -- containing the actual occurs within the body of G or within the body
10299 -- of a generic unit declared within the declarative region of G, then
10300 -- the declaration of the formal object of G must have a null exclusion.
10301 -- Otherwise, the subtype of the actual matching the formal object
10302 -- declaration shall exclude null.
10306 and then
10308 N_Object_Declaration)
10312 then
10314 Error_Msg_N
10318 -- An effectively volatile object cannot be used as an actual in
10319 -- a generic instance. The following check is only relevant when
10320 -- SPARK_Mode is on as it is not a standard Ada legality rule.
10325 then
10326 Error_Msg_N
10334 ------------------------------
10335 -- Instantiate_Package_Body --
10336 ------------------------------
10338 procedure Instantiate_Package_Body
10342 is
10366 -- List of primitives made temporarily visible in the instantiation
10367 -- to match the visibility of the formal type
10370 -- In a generic package body, an entity of a generic private type may
10371 -- appear uninitialized. This is suspicious, unless the actual is a
10372 -- fully initialized type.
10374 -----------------------------
10375 -- Check_Initialized_Types --
10376 -----------------------------
10384 begin
10394 N_Formal_Private_Type_Definition
10395 then
10396 Uninit_Var :=
10404 -- For each formal there is a subtype declaration that renames
10405 -- the actual and has the same name as the formal. Locate the
10406 -- formal for warning message about uninitialized variables
10407 -- in the generic, for which the actual type should be a fully
10408 -- initialized type.
10417 and then Warn_On_No_Value_Assigned
10418 then
10420 Error_Msg_NE
10423 Error_Msg_NE
10437 -- Start of processing for Instantiate_Package_Body
10439 begin
10442 -- The instance body may already have been processed, as the parent of
10443 -- another instance that is inlined (Load_Parent_Of_Generic).
10451 -- Re-establish the state of information on which checks are suppressed.
10452 -- This information was set in Body_Info at the point of instantiation,
10453 -- and now we restore it so that the instance is compiled using the
10454 -- check status at the instantiation (RM 11.5 (7.2/2), AI95-00224-01).
10466 -- Do not look for parent of generic body if none is required.
10467 -- This may happen when the routine is called as part of the
10468 -- Pending_Instantiations processing, when nested instances
10469 -- may precede the one generated from the main unit.
10472 and then Body_Optional
10473 then
10475 else
10476 Load_Parent_Of_Generic
10482 -- Establish global variable for sloc adjustment and for error recovery
10493 Create_Instantiation_Source
10496 Act_Body :=
10497 Copy_Generic_Node
10500 -- Build new name (possibly qualified) for body declaration
10504 -- Some attributes of spec entity are not inherited by body entity
10509 N_Defining_Program_Unit_Name
10510 then
10511 Act_Body_Name :=
10515 else
10523 Check_Initialized_Types;
10525 -- Install primitives hidden at the point of the instantiation but
10526 -- visible when processing the generic formals
10528 declare
10531 begin
10537 then
10538 Install_Hidden_Primitives
10548 -- If it is a child unit, make the parent instance (which is an
10549 -- instance of the parent of the generic) visible. The parent
10550 -- instance is the prefix of the name of the generic unit.
10554 then
10567 -- If the instantiation is a library unit, and this is the main unit,
10568 -- then build the resulting compilation unit nodes for the instance.
10569 -- If this is a compilation unit but it is not the main unit, then it
10570 -- is the body of a unit in the context, that is being compiled
10571 -- because it is encloses some inlined unit or another generic unit
10572 -- being instantiated. In that case, this body is not part of the
10573 -- current compilation, and is not attached to the tree, but its
10574 -- parent must be set for analysis.
10578 -- Replace instance node with body of instance, and create new
10579 -- node for corresponding instance declaration.
10581 Build_Instance_Compilation_Unit_Nodes
10587 -- If the instance is a child unit itself, then set the scope
10588 -- of the expanded body to be the parent of the instantiation
10589 -- (ensuring that the fully qualified name will be generated
10590 -- for the elaboration subprogram).
10593 N_Defining_Program_Unit_Name
10594 then
10595 Set_Scope
10600 -- Case where instantiation is not a library unit
10602 else
10603 -- If this is an early instantiation, i.e. appears textually
10604 -- before the corresponding body and must be elaborated first,
10605 -- indicate that the body instance is to be delayed.
10609 -- Now analyze the body. We turn off all checks if this is an
10610 -- internal unit, since there is no reason to have checks on for
10611 -- any predefined run-time library code. All such code is designed
10612 -- to be compiled with checks off.
10614 -- Note that we do NOT apply this criterion to children of GNAT
10615 -- The latter units must suppress checks explicitly if needed.
10617 if Is_Predefined_File_Name
10619 then
10621 else
10628 -- Remove the parent instances if they have been placed on the scope
10629 -- stack to compile the body.
10634 -- Restore the previous visibility of the parent
10642 -- Remove the current unit from visibility if this is an instance
10643 -- that is not elaborated on the fly for inlining purposes.
10649 Restore_Env;
10652 -- If we have no body, and the unit requires a body, then complain. This
10653 -- complaint is suppressed if we have detected other errors (since a
10654 -- common reason for missing the body is that it had errors).
10655 -- In CodePeer mode, a warning has been emitted already, no need for
10656 -- further messages.
10659 and then not Body_Optional
10660 then
10665 Error_Msg_NE
10668 -- Don't attempt to perform any cleanup actions if some other error
10669 -- was already detected, since this can cause blowups.
10671 else
10675 -- Case of package that does not need a body
10677 else
10678 -- If the instantiation of the declaration is a library unit, rewrite
10679 -- the original package instantiation as a package declaration in the
10680 -- compilation unit node.
10686 -- Generate elaboration entity, in case spec has elaboration code.
10687 -- This cannot be done when the instance is analyzed, because it
10688 -- is not known yet whether the body exists.
10693 -- If the instantiation is not a library unit, then append the
10694 -- declaration to the list of implicitly generated entities, unless
10695 -- it is already a list member which means that it was already
10696 -- processed
10704 Expander_Mode_Restore;
10707 ---------------------------------
10708 -- Instantiate_Subprogram_Body --
10709 ---------------------------------
10711 procedure Instantiate_Subprogram_Body
10714 is
10742 begin
10745 -- Subprogram body may have been created already because of an inline
10746 -- pragma, or because of multiple elaborations of the enclosing package
10747 -- when several instances of the subprogram appear in the main unit.
10755 -- Re-establish the state of information on which checks are suppressed.
10756 -- This information was set in Body_Info at the point of instantiation,
10757 -- and now we restore it so that the instance is compiled using the
10758 -- check status at the instantiation (RM 11.5 (7.2/2), AI95-00224-01).
10770 -- For imported generic subprogram, no body to compile, complete
10771 -- the spec entity appropriately.
10781 -- For other cases, compile the body
10783 else
10784 Load_Parent_Of_Generic
10797 -- Either body is not present, or context is non-expanding, as
10798 -- when compiling a subunit. Mark the instance as completed, and
10799 -- diagnose a missing body when needed.
10801 if Expander_Active
10803 then
10804 Error_Msg_N
10815 Create_Instantiation_Source
10817 Gen_Body_Id,
10819 S_Adjustment);
10821 Act_Body :=
10822 Copy_Generic_Node
10825 -- Create proper defining name for the body, to correspond to
10826 -- the one in the spec.
10829 Make_Defining_Identifier
10835 -- Generate a reference to link the visible subprogram instance to
10836 -- the generic body, which for navigation purposes is the only
10837 -- available source for the instance.
10839 Generate_Reference
10843 -- If it is a child unit, make the parent instance (which is an
10844 -- instance of the parent of the generic) visible. The parent
10845 -- instance is the prefix of the name of the generic unit.
10849 then
10862 -- Inside its body, a reference to the generic unit is a reference
10863 -- to the instance. The corresponding renaming is the first
10864 -- declaration in the body.
10866 Unit_Renaming :=
10868 Specification =>
10869 Copy_Generic_Node (
10871 Empty,
10875 -- If there is a formal subprogram with the same name as the unit
10876 -- itself, do not add this renaming declaration. This is a temporary
10877 -- fix for one ACVC test. ???
10883 then
10892 else
10896 -- The subprogram body is placed in the body of a dummy package body,
10897 -- whose spec contains the subprogram declaration as well as the
10898 -- renaming declarations for the generic parameters.
10906 -- If the instantiation is a library unit, then build resulting
10907 -- compilation unit nodes for the instance. The declaration of
10908 -- the enclosing package is the grandparent of the subprogram
10909 -- declaration. First replace the instantiation node as the unit
10910 -- of the corresponding compilation.
10915 Build_Instance_Compilation_Unit_Nodes
10918 else
10923 else
10940 -- Restore the previous visibility of the parent
10945 Restore_Env;
10949 -- Body not found. Error was emitted already. If there were no previous
10950 -- errors, this may be an instance whose scope is a premature instance.
10951 -- In that case we must insure that the (legal) program does raise
10952 -- program error if executed. We generate a subprogram body for this
10953 -- purpose. See DEC ac30vso.
10955 -- Should not reference proprietary DEC tests in comments ???
10959 then
10964 Act_Body :=
10966 Specification =>
10968 Defining_Unit_Name =>
10970 Parameter_Specifications =>
10971 New_Copy_List
10975 Handled_Statement_Sequence =>
10977 Statements =>
10978 New_List (
10980 Reason =>
10981 PE_Access_Before_Elaboration))));
10983 else
10984 Ret_Expr :=
10991 Act_Body :=
10993 Specification =>
10995 Defining_Unit_Name =>
10997 Parameter_Specifications =>
10998 New_Copy_List
11000 Result_Definition =>
11004 Handled_Statement_Sequence =>
11006 Statements =>
11007 New_List
11020 Expander_Mode_Restore;
11023 ----------------------
11024 -- Instantiate_Type --
11025 ----------------------
11027 function Instantiate_Type
11032 is
11045 -- There are a number of constructs in which a discrete type with
11046 -- predicates is illegal, e.g. as an index in an array type declaration.
11047 -- If a generic type is used is such a construct in a generic package
11048 -- declaration, it carries the flag No_Predicate_On_Actual. it is part
11049 -- of the generic contract that the actual cannot have predicates.
11060 -- These procedures perform validation tests for the named case.
11061 -- Validate_Discriminated_Formal_Type is shared by formal private
11062 -- types and Ada 2012 formal incomplete types.
11065 -- Check that base types are the same and that the subtypes match
11066 -- statically. Used in several of the above.
11068 ---------------------------------
11069 -- Diagnose_Predicated_Actual --
11070 ---------------------------------
11073 begin
11076 then
11077 Error_Msg_NE
11084 then
11085 Error_Msg_NE
11091 --------------------
11092 -- Subtypes_Match --
11093 --------------------
11098 begin
11099 -- Some detailed comments would be useful here ???
11107 and then Subtypes_Match
11111 or else
11113 E_Anonymous_Access_Type)
11115 and then Subtypes_Statically_Match
11119 -----------------------------------------
11120 -- Validate_Access_Subprogram_Instance --
11121 -----------------------------------------
11124 begin
11127 then
11128 Error_Msg_NE
11133 -- According to AI05-288, actuals for access_to_subprograms must be
11134 -- subtype conformant with the generic formal. Previous to AI05-288
11135 -- only mode conformance was required.
11137 -- This is a binding interpretation that applies to previous versions
11138 -- of the language, no need to maintain previous weaker checks.
11140 Check_Subtype_Conformant
11143 Actual,
11148 Error_Msg_NE
11154 Error_Msg_NE
11160 -----------------------------------
11161 -- Validate_Access_Type_Instance --
11162 -----------------------------------
11169 begin
11171 Error_Msg_NE
11178 Error_Msg_N
11182 else
11184 Error_Msg_N
11190 then
11191 Error_Msg_N -- CODEFIX
11193 Error_Msg_NE -- CODEFIX
11199 -- The designated subtypes, that is to say the subtypes introduced
11200 -- by an access type declaration (and not by a subtype declaration)
11201 -- must match.
11205 -- The designated type may have been introduced through a limited_
11206 -- with clause, in which case retrieve the non-limited view. This
11207 -- applies to incomplete types as well as to class-wide types.
11214 Error_Msg_NE
11226 /=
11228 then
11229 Error_Msg_NE
11240 -- Ada 2005: null-exclusion indicators of the two types must agree
11243 Error_Msg_NE
11249 ----------------------------------
11250 -- Validate_Array_Type_Instance --
11251 ----------------------------------
11259 -- Count number of dimensions in array type formal
11261 -----------------------
11262 -- Formal_Dimensions --
11263 -----------------------
11269 begin
11272 else
11284 -- Start of processing for Validate_Array_Type_Instance
11286 begin
11288 Error_Msg_NE
11294 Error_Msg_NE
11300 else
11302 Error_Msg_NE
11310 Error_Msg_NE
11319 -- If the indexes of the actual were given by a subtype_mark,
11320 -- the index was transformed into a range attribute. Retrieve
11321 -- the original type mark for checking.
11325 else
11329 if not Subtypes_Match
11331 then
11332 Error_Msg_NE
11342 -- Check matching subtypes. Note that there are complex visibility
11343 -- issues when the generic is a child unit and some aspect of the
11344 -- generic type is declared in a parent unit of the generic. We do
11345 -- the test to handle this special case only after a direct check
11346 -- for static matching has failed. The case where both the component
11347 -- type and the array type are separate formals, and the component
11348 -- type is a private view may also require special checking in
11349 -- Subtypes_Match.
11351 if Subtypes_Match
11353 or else
11354 Subtypes_Match
11357 then
11359 else
11360 Error_Msg_NE
11368 then
11369 Error_Msg_NE
11375 -----------------------------------------------
11376 -- Validate_Derived_Interface_Type_Instance --
11377 -----------------------------------------------
11383 begin
11384 -- First apply interface instance checks
11386 Validate_Interface_Type_Instance;
11388 -- Verify that immediate parent interface is an ancestor of
11389 -- the actual.
11393 then
11394 Error_Msg_NE
11398 -- Now verify that the actual includes all other ancestors of
11399 -- the formal.
11403 if not Interface_Present_In_Ancestor
11405 then
11406 Error_Msg_NE
11415 ------------------------------------
11416 -- Validate_Derived_Type_Instance --
11417 ------------------------------------
11423 begin
11424 -- If the parent type in the generic declaration is itself a previous
11425 -- formal type, then it is local to the generic and absent from the
11426 -- analyzed generic definition. In that case the ancestor is the
11427 -- instance of the formal (which must have been instantiated
11428 -- previously), unless the ancestor is itself a formal derived type.
11429 -- In this latter case (which is the subject of Corrigendum 8652/0038
11430 -- (AI-202) the ancestor of the formals is the ancestor of its
11431 -- parent. Otherwise, the analyzed generic carries the parent type.
11432 -- If the parent type is defined in a previous formal package, then
11433 -- the scope of that formal package is that of the generic type
11434 -- itself, and it has already been mapped into the corresponding type
11435 -- in the actual package.
11437 -- Common case: parent type defined outside of the generic
11441 then
11444 -- Check whether parent is defined in a previous formal package
11446 elsif
11448 then
11449 Ancestor :=
11452 -- The type may be a local derivation, or a type extension of a
11453 -- previous formal, or of a formal of a parent package.
11456 or else
11458 then
11459 -- Check whether the parent is another derived formal type in the
11460 -- same generic unit.
11466 then
11467 -- Locate ancestor of parent from the subtype declaration
11468 -- created for the actual.
11470 declare
11473 begin
11479 then
11482 else
11490 -- The ancestor itself may be a previous formal that has been
11491 -- instantiated.
11495 else
11496 Ancestor :=
11500 -- An unusual case: the actual is a type declared in a parent unit,
11501 -- but is not a formal type so there is no instance_of for it.
11502 -- Retrieve it by analyzing the record extension.
11507 then
11511 else
11515 -- If the formal derived type has pragma Preelaborable_Initialization
11516 -- then the actual type must have preelaborable initialization.
11520 then
11521 Error_Msg_NE
11526 -- Ada 2005 (AI-251)
11530 Error_Msg_NE
11536 Error_Msg_NE
11542 -- Ada 2005 (AI-443): Synchronized formal derived type checks. Note
11543 -- that the formal type declaration has been rewritten as a private
11544 -- extension.
11549 then
11550 -- The actual must be a synchronized tagged type
11553 Error_Msg_N
11559 N_Derived_Type_Definition
11562 then
11563 Error_Msg_N
11569 -- Perform atomic/volatile checks (RM C.6(12)). Note that AI05-0218-1
11570 -- removes the second instance of the phrase "or allow pass by copy".
11573 Error_Msg_N
11575 Actual);
11578 Error_Msg_N
11580 Actual);
11583 -- It should not be necessary to check for unknown discriminants on
11584 -- Formal, but for some reason Has_Unknown_Discriminants is false for
11585 -- A_Gen_T, so Is_Indefinite_Subtype incorrectly returns False. This
11586 -- needs fixing. ???
11591 then
11592 Error_Msg_N
11600 Error_Msg_N
11605 -- Ancestor is unconstrained, Check if generic formal and actual
11606 -- agree on constrainedness. The check only applies to array types
11607 -- and discriminated types.
11613 then
11618 -- A class-wide type is only allowed if the formal has unknown
11619 -- discriminants.
11623 then
11624 Error_Msg_NE
11628 -- Otherwise, the formal and actual must have the same number
11629 -- of discriminants and each discriminant of the actual must
11630 -- correspond to a discriminant of the formal.
11635 then
11640 loop
11643 then
11644 Error_Msg_NE
11655 Error_Msg_NE
11661 -- This case should be caught by the earlier check for
11662 -- constrainedness, but the check here is added for completeness.
11666 then
11667 Error_Msg_NE
11672 Error_Msg_NE
11677 if not Subtypes_Statically_Compatible
11679 then
11680 Error_Msg_N
11686 -- If the formal and actual types are abstract, check that there
11687 -- are no abstract primitives of the actual type that correspond to
11688 -- nonabstract primitives of the formal type (second sentence of
11689 -- RM95-3.9.3(9)).
11710 -- Returns true if T2 is derived directly or indirectly from
11711 -- T1, including derivations from interfaces. T1 and T2 are
11712 -- required to be specific tagged base types.
11714 ------------------------
11715 -- Is_Tagged_Ancestor --
11716 ------------------------
11719 is
11722 begin
11723 -- The predicate is satisfied if the types are the same
11728 -- If we've reached the top of the derivation chain then
11729 -- we know that T1 is not an ancestor of T2.
11734 -- Proceed to check T2's immediate parent
11739 -- Finally, check to see if T1 is an ancestor of any of T2's
11740 -- progenitors.
11742 else
11756 -- Start of processing for Check_Abstract_Primitives
11758 begin
11759 -- Loop over all of the formal derived type's primitives
11765 -- If the primitive of the formal is not abstract, then
11766 -- determine whether there is a corresponding primitive of
11767 -- the actual type that's abstract.
11774 -- If we find an abstract primitive of the actual,
11775 -- then we need to test whether it corresponds to the
11776 -- subprogram from which the generic formal primitive
11777 -- is inherited.
11782 -- Test whether we have a corresponding primitive
11783 -- by comparing names, kinds, formal types, and
11784 -- result types.
11788 then
11793 loop
11798 = E_Anonymous_Access_Type
11799 then
11803 = E_Anonymous_Access_Type
11804 then
11805 Act_F_Type :=
11807 else
11811 elsif
11813 then
11820 -- If the formal is controlling, then the
11821 -- the type of the actual primitive's formal
11822 -- must be derived directly or indirectly
11823 -- from the type of the ancestor primitive's
11824 -- formal.
11827 if not Is_Tagged_Ancestor
11829 then
11833 -- Otherwise the types of the formals must
11834 -- be the same.
11844 -- If we traversed through all of the formals
11845 -- then so far the subprograms correspond, so
11846 -- now check that any result types correspond.
11856 = E_Anonymous_Access_Type
11857 then
11858 Anc_F_Type :=
11862 = E_Anonymous_Access_Type
11863 then
11864 Act_F_Type :=
11866 else
11870 elsif
11872 = E_Anonymous_Access_Type
11873 then
11880 -- Now either the result types must be
11881 -- the same or, if the result type is
11882 -- controlling, the result type of the
11883 -- actual primitive must descend from the
11884 -- result type of the ancestor primitive.
11886 if Subprograms_Correspond
11888 and then
11890 and then
11891 not Is_Tagged_Ancestor
11893 then
11898 -- Found a matching subprogram belonging to
11899 -- formal ancestor type, so actual subprogram
11900 -- corresponds and this violates 3.9.3(9).
11903 Error_Msg_NE
11906 Actual,
11907 Act_Subp);
11922 -- Verify that limitedness matches. If parent is a limited
11923 -- interface then the generic formal is not unless declared
11924 -- explicitly so. If not declared limited, the actual cannot be
11925 -- limited (see AI05-0087).
11927 -- Even though this AI is a binding interpretation, we enable the
11928 -- check only in Ada 2012 mode, because this improper construct
11929 -- shows up in user code and in existing B-tests.
11934 then
11937 else
11938 Error_Msg_NE
11940 Gen_T);
11947 ----------------------------------------
11948 -- Validate_Discriminated_Formal_Type --
11949 ----------------------------------------
11956 begin
11959 Error_Msg_NE
11964 Error_Msg_NE
11968 else
11973 Error_Msg_NE
11981 -- Access discriminants match if designated types do
11985 E_Anonymous_Access_Type
11986 and then
11987 Get_Instance_Of
11990 then
11995 then
11996 Error_Msg_NE
12001 elsif not Subtypes_Statically_Match
12004 then
12005 Error_Msg_NE
12016 Error_Msg_NE
12025 ---------------------------------------
12026 -- Validate_Incomplete_Type_Instance --
12027 ---------------------------------------
12030 begin
12033 then
12034 Error_Msg_NE
12038 Validate_Discriminated_Formal_Type;
12041 --------------------------------------
12042 -- Validate_Interface_Type_Instance --
12043 --------------------------------------
12046 begin
12048 Error_Msg_NE
12058 then
12059 Error_Msg_NE
12065 ------------------------------------
12066 -- Validate_Private_Type_Instance --
12067 ------------------------------------
12070 begin
12073 then
12076 else
12077 Error_Msg_NE
12079 Gen_T);
12086 then
12087 Error_Msg_NE
12089 Gen_T);
12094 then
12095 Error_Msg_NE
12100 then
12101 Error_Msg_NE
12105 Validate_Discriminated_Formal_Type;
12109 -- Start of processing for Instantiate_Type
12111 begin
12118 then
12119 Error_Msg_NE
12123 else
12126 -- Ada 2005 (AI-216): An Unchecked_Union subtype shall only be passed
12127 -- as a generic actual parameter if the corresponding formal type
12128 -- does not have a known_discriminant_part, or is a formal derived
12129 -- type that is an Unchecked_Union type.
12135 then
12137 else
12144 -- Deal with fixed/floating restrictions
12152 -- Deal with error of using incomplete type as generic actual.
12153 -- This includes limited views of a type, even if the non-limited
12154 -- view may be available.
12159 then
12160 -- If the formal is an incomplete type, the actual can be
12161 -- incomplete as well.
12168 then
12171 else
12176 Error_Msg_N
12181 -- Deal with error of premature use of private type as generic actual
12188 then
12189 -- If the formal is an incomplete type, the actual can be
12190 -- private or incomplete as well.
12194 else
12199 Error_Msg_N
12205 -- If the type is generic, the class-wide type may also be used
12210 then
12217 then
12218 Error_Msg_N
12222 -- A generic scalar type is a first subtype for which we generate
12223 -- an anonymous base type. Indicate that the instance of this base
12224 -- is the base type of the actual.
12233 else
12236 Validate_Private_Type_Instance;
12239 Validate_Incomplete_Type_Instance;
12242 Validate_Derived_Type_Instance;
12246 Error_Msg_NE
12252 Diagnose_Predicated_Actual;
12256 Error_Msg_NE
12262 Diagnose_Predicated_Actual;
12266 Error_Msg_NE
12272 Diagnose_Predicated_Actual;
12276 Error_Msg_NE
12283 Error_Msg_NE
12291 Error_Msg_NE
12298 Validate_Array_Type_Instance;
12301 Validate_Access_Type_Instance;
12303 when N_Access_Function_Definition |
12304 N_Access_Procedure_Definition =>
12305 Validate_Access_Subprogram_Instance;
12308 Validate_Interface_Type_Instance;
12311 Validate_Derived_Interface_Type_Instance;
12321 -- Use adjusted sloc of subtype name as the location for other nodes in
12322 -- the subtype declaration.
12326 Decl_Node :=
12336 then
12342 -- Flag actual derived types so their elaboration produces the
12343 -- appropriate renamings for the primitive operations of the ancestor.
12344 -- Flag actual for formal private types as well, to determine whether
12345 -- operations in the private part may override inherited operations.
12346 -- If the formal has an interface list, the ancestor is not the
12347 -- parent, but the analyzed formal that includes the interface
12348 -- operations of all its progenitors.
12350 -- Same treatment for formal private types, so we can check whether the
12351 -- type is tagged limited when validating derivations in the private
12352 -- part. (See AI05-096).
12357 else
12362 N_Formal_Private_Type_Definition,
12363 N_Formal_Incomplete_Type_Definition)
12364 then
12368 -- If the actual is a synchronized type that implements an interface,
12369 -- the primitive operations are attached to the corresponding record,
12370 -- and we have to treat it as an additional generic actual, so that its
12371 -- primitive operations become visible in the instance. The task or
12372 -- protected type itself does not carry primitive operations.
12379 then
12380 declare
12386 begin
12388 Corr_Decl :=
12391 Subtype_Indication =>
12397 else
12410 ---------------------
12411 -- Is_In_Main_Unit --
12412 ---------------------
12418 begin
12422 -- If the current unit is a subunit then it is either the main unit or
12423 -- is being compiled as part of the main unit.
12432 loop
12436 -- The instantiation node is in the main unit, or else the current node
12437 -- (perhaps as the result of nested instantiations) is in the main unit,
12438 -- or in the declaration of the main unit, which in this last case must
12439 -- be a body.
12448 ----------------------------
12449 -- Load_Parent_Of_Generic --
12450 ----------------------------
12452 procedure Load_Parent_Of_Generic
12456 is
12466 -- Collect all instantiations in the given list of declarations, that
12467 -- precede the generic that we need to load. If the bodies of these
12468 -- instantiations are available, we must analyze them, to ensure that
12469 -- the public symbols generated are the same when the unit is compiled
12470 -- to generate code, and when it is compiled in the context of a unit
12471 -- that needs a particular nested instance. This process is applied to
12472 -- both package and subprogram instances.
12474 --------------------------------
12475 -- Collect_Previous_Instances --
12476 --------------------------------
12481 begin
12487 -- If Decl is an instantiation, then record it as requiring
12488 -- instantiation of the corresponding body, except if it is an
12489 -- abbreviated instantiation generated internally for conformance
12490 -- checking purposes only for the case of a formal package
12491 -- declared without a box (see Instantiate_Formal_Package). Such
12492 -- an instantiation does not generate any code (the actual code
12493 -- comes from actual) and thus does not need to be analyzed here.
12494 -- If the instantiation appears with a generic package body it is
12495 -- not analyzed here either.
12499 then
12502 -- For a subprogram instantiation, omit instantiations intrinsic
12503 -- operations (Unchecked_Conversions, etc.) that have no bodies.
12506 N_Procedure_Instantiation)
12508 then
12512 Collect_Previous_Instances
12514 Collect_Previous_Instances
12517 -- Previous non-generic bodies may contain instances as well
12521 then
12527 then
12535 -- Start of processing for Load_Parent_Of_Generic
12537 begin
12542 then
12543 -- Find body of parent of spec, and analyze it. A special case arises
12544 -- when the parent is an instantiation, that is to say when we are
12545 -- currently instantiating a nested generic. In that case, there is
12546 -- no separate file for the body of the enclosing instance. Instead,
12547 -- the enclosing body must be instantiated as if it were a pending
12548 -- instantiation, in order to produce the body for the nested generic
12549 -- we require now. Note that in that case the generic may be defined
12550 -- in a package body, the instance defined in the same package body,
12551 -- and the original enclosing body may not be in the main unit.
12558 loop
12560 and then
12562 then
12563 -- Parent is a compilation unit that is an instantiation.
12564 -- Instantiation node has been replaced with package decl.
12572 then
12573 -- Parent is an instantiation within another specification.
12574 -- Declaration for instance has been inserted before original
12575 -- instantiation node. A direct link would be preferable?
12580 loop
12584 -- If the instance appears within a generic, and the generic
12585 -- unit is defined within a formal package of the enclosing
12586 -- generic, there is no generic body available, and none
12587 -- needed. A more precise test should be used ???
12595 else
12600 -- Case where we are currently instantiating a nested generic
12605 -- Instantiation node and declaration of instantiated package
12606 -- were exchanged when only the declaration was needed.
12607 -- Restore instantiation node before proceeding with body.
12612 -- Now complete instantiation of enclosing body, if it appears in
12613 -- some other unit. If it appears in the current unit, the body
12614 -- will have been instantiated already.
12618 -- We need to determine the expander mode to instantiate the
12619 -- enclosing body. Because the generic body we need may use
12620 -- global entities declared in the enclosing package (including
12621 -- aggregates) it is in general necessary to compile this body
12622 -- with expansion enabled, except if we are within a generic
12623 -- package, in which case the usual generic rule applies.
12625 declare
12629 begin
12630 -- Loop through scopes looking for generic package
12635 loop
12644 -- Collect previous instantiations in the unit that contains
12645 -- the desired generic.
12648 and then not Body_Optional
12649 then
12650 declare
12655 begin
12668 Collect_Previous_Instances
12670 Collect_Previous_Instances
12673 else
12674 -- Enclosing unit is a subprogram body. In this
12675 -- case all instance bodies are processed in order
12676 -- and there is no need to collect them separately.
12683 Info :=
12685 Act_Decl =>
12688 Current_Sem_Unit =>
12691 Local_Suppress_Stack_Top =>
12692 Local_Suppress_Stack_Top,
12699 -- Package instance
12701 if
12703 then
12704 Instantiate_Package_Body
12707 -- Subprogram instance
12709 else
12710 -- The instance_spec is the wrapper package,
12711 -- and the subprogram declaration is the last
12712 -- declaration in the wrapper.
12715 Last
12716 (Visible_Declarations
12719 Instantiate_Subprogram_Body
12728 Instantiate_Package_Body
12733 Current_Sem_Unit => Get_Code_Unit
12746 -- Case where we are not instantiating a nested generic
12748 else
12754 Expander_Mode_Restore;
12756 if not OK
12758 and then not Body_Optional
12759 then
12760 declare
12764 begin
12765 -- In CodePeer mode, the missing body may make the analysis
12766 -- incomplete, but we do not treat it as fatal.
12771 else
12774 Error_Msg_File_1 :=
12784 -- If loading parent of the generic caused an instantiation circularity,
12785 -- we abandon compilation at this point, because otherwise in some cases
12786 -- we get into trouble with infinite recursions after this point.
12793 ---------------------------------
12794 -- Map_Formal_Package_Entities --
12795 ---------------------------------
12801 begin
12804 -- Traverse formal and actual package to map the corresponding entities.
12805 -- We skip over internal entities that may be generated during semantic
12806 -- analysis, and find the matching entities by name, given that they
12807 -- must appear in the same order.
12812 -- Could this test be a single condition??? Seems like it could, and
12813 -- isn't FPE (Form) a constant anyway???
12819 then
12826 else
12847 -----------------------
12848 -- Move_Freeze_Nodes --
12849 -----------------------
12851 procedure Move_Freeze_Nodes
12855 is
12862 -- Check whether entity is declared in a scope external to that of the
12863 -- generic unit.
12865 -------------------
12866 -- Is_Outer_Type --
12867 -------------------
12872 begin
12876 else
12880 else
12889 -- Start of processing for Move_Freeze_Nodes
12891 begin
12896 -- First remove the freeze nodes that may appear before all other
12897 -- declarations.
12903 loop
12911 -- Next scan the list of declarations and remove each freeze node that
12912 -- appears ahead of the current node.
12918 loop
12925 -- If the declaration is a nested package or concurrent type, then
12926 -- recurse. Nested generic packages will have been processed from the
12927 -- inside out.
12952 ----------------
12953 -- Next_Assoc --
12954 ----------------
12957 begin
12961 ------------------------
12962 -- Preanalyze_Actuals --
12963 ------------------------
12971 -- Current homograph of the instance name
12974 -- Saved visibility status of the current homograph
12976 begin
12979 -- If the instance is a child unit, its name may hide an outer homonym,
12980 -- so make it invisible to perform name resolution on the actuals.
12983 and then Present
12985 then
12991 else
13000 -- Within a nested instantiation, a defaulted actual is an empty
13001 -- association, so nothing to analyze. If the subprogram actual
13002 -- is an attribute, analyze prefix only, because actual is not a
13003 -- complete attribute reference.
13005 -- If actual is an allocator, analyze expression only. The full
13006 -- analysis can generate code, and if instance is a compilation
13007 -- unit we have to wait until the package instance is installed
13008 -- to have a proper place to insert this code.
13010 -- String literals may be operators, but at this point we do not
13011 -- know whether the actual is a formal subprogram or a string.
13023 declare
13026 begin
13030 -- Analyze separately each discriminant constraint, when
13031 -- given with a named association.
13033 declare
13036 begin
13041 else
13049 else
13060 -- Do a minimal analysis of the generic, to prevent spurious
13061 -- warnings complaining about the generic being unreferenced,
13062 -- before abandoning the instantiation.
13068 then
13075 -- For the case of a child instance hiding an outer homonym,
13076 -- provide additional warning which might explain the error.
13095 -------------------
13096 -- Remove_Parent --
13097 -------------------
13101 -- S is the scope containing the instantiation just completed. The scope
13102 -- stack contains the parent instances of the instantiation, followed by
13103 -- the original S.
13110 begin
13111 -- After child instantiation is complete, remove from scope stack the
13112 -- extra copy of the current scope, and then remove parent instances.
13115 Pop_Scope;
13128 -- If instantiation is declared in a block, it is the enclosing
13129 -- scope that might be a parent instance. Note that only one
13130 -- block can be involved, because the parent instances have
13131 -- been installed within it.
13135 else
13140 -- We are within an instance of some sibling. Retain
13141 -- visibility of parent, for proper subsequent cleanup, and
13142 -- reinstall private declarations as well.
13148 -- If the ultimate parent is a top-level unit recorded in
13149 -- Instance_Parent_Unit, then reset its visibility to what it was
13150 -- before instantiation. (It's not clear what the purpose is of
13151 -- testing whether Scope (P) is In_Open_Scopes, but that test was
13152 -- present before the ultimate parent test was added.???)
13157 then
13160 -- If the current scope is itself an instantiation of a generic
13161 -- nested within P, and we are in the private part of body of this
13162 -- instantiation, restore the full views of P, that were removed
13163 -- in End_Package_Scope above. This obscure case can occur when a
13164 -- subunit of a generic contains an instance of a child unit of
13165 -- its generic parent unit.
13168 declare
13171 begin
13175 then
13183 -- Reset visibility of entities in the enclosing scope
13193 else
13194 -- Each body is analyzed separately, and there is no context that
13195 -- needs preserving from one body instance to the next, so remove all
13196 -- parent scopes that have been installed.
13207 -----------------
13208 -- Restore_Env --
13209 -----------------
13214 begin
13216 -- Restore environment after subprogram inlining
13233 ---------------------------
13234 -- Restore_Private_Views --
13235 ---------------------------
13237 procedure Restore_Private_Views
13240 is
13248 -- Hide the generic formals of formal packages declared with box which
13249 -- were reachable in the current instantiation.
13251 ---------------------------
13252 -- Restore_Nested_Formal --
13253 ---------------------------
13258 begin
13261 then
13273 -- If package, then recurse
13284 -- Start of processing for Restore_Private_Views
13286 begin
13291 -- Subtypes of types whose views have been exchanged, and that are
13292 -- defined within the instance, were not on the Private_Dependents
13293 -- list on entry to the instance, so they have to be exchanged
13294 -- explicitly now, in order to remain consistent with the view of the
13295 -- parent type.
13298 E_Limited_Private_Type,
13299 E_Record_Type_With_Private)
13300 then
13307 then
13324 -- Make the generic formal parameters private, and make the formal types
13325 -- into subtypes of the actuals again.
13333 then
13334 -- If the actual for E is itself a generic actual type from
13335 -- an enclosing instance, E is still a generic actual type
13336 -- outside of the current instance. This matter when resolving
13337 -- an overloaded call that may be ambiguous in the enclosing
13338 -- instance, when two of its actuals coincide.
13341 and then Is_Generic_Actual_Type
13343 then
13345 else
13349 -- An unusual case of aliasing: the actual may also be directly
13350 -- visible in the generic, and be private there, while it is fully
13351 -- visible in the context of the instance. The internal subtype
13352 -- is private in the instance but has full visibility like its
13353 -- parent in the enclosing scope. This enforces the invariant that
13354 -- the privacy status of all private dependents of a type coincide
13355 -- with that of the parent type. This can only happen when a
13356 -- generic child unit is instantiated within a sibling.
13360 then
13366 -- The end of the renaming list is the renaming of the generic
13367 -- package itself. If the instance is a subprogram, all entities
13368 -- in the corresponding package are renamings. If this entity is
13369 -- a formal package, make its own formals private as well. The
13370 -- actual in this case is itself the renaming of an instantiation.
13371 -- If the entity is not a package renaming, it is the entity
13372 -- created to validate formal package actuals: ignore it.
13374 -- If the actual is itself a formal package for the enclosing
13375 -- generic, or the actual for such a formal package, it remains
13376 -- visible on exit from the instance, and therefore nothing needs
13377 -- to be done either, except to keep it accessible.
13385 elsif
13387 then
13390 else
13391 declare
13395 begin
13399 loop
13420 --------------
13421 -- Save_Env --
13422 --------------
13424 procedure Save_Env
13427 is
13428 begin
13429 Init_Env;
13433 ----------------------------
13434 -- Save_Global_References --
13435 ----------------------------
13443 -- Check whether entity is defined outside of generic unit. Examine the
13444 -- scope of an entity, and the scope of the scope, etc, until we find
13445 -- either Standard, in which case the entity is global, or the generic
13446 -- unit itself, which indicates that the entity is local. If the entity
13447 -- is the generic unit itself, as in the case of a recursive call, or
13448 -- the enclosing generic unit, if different from the current scope, then
13449 -- it is local as well, because it will be replaced at the point of
13450 -- instantiation. On the other hand, if it is a reference to a child
13451 -- unit of a common ancestor, which appears in an instantiation, it is
13452 -- global because it is used to denote a specific compilation unit at
13453 -- the time the instantiations will be analyzed.
13456 -- Save semantic information on global entity so that it is not resolved
13457 -- again at instantiation time.
13460 -- Apply Save_Global_References to the two syntactic descendants of
13461 -- non-terminal nodes that carry an Associated_Node and are processed
13462 -- through Reset_Entity. Once the global entity (if any) has been
13463 -- captured together with its type, only two syntactic descendants need
13464 -- to be traversed to complete the processing of the tree rooted at N.
13465 -- This applies to Selected_Components, Expanded_Names, and to Operator
13466 -- nodes. N can also be a character literal, identifier, or operator
13467 -- symbol node, but the call has no effect in these cases.
13470 -- Default actuals in nested instances must be handled specially
13471 -- because there is no link to them from the original tree. When an
13472 -- actual subprogram is given by a default, we add an explicit generic
13473 -- association for it in the instantiation node. When we save the
13474 -- global references on the name of the instance, we recover the list
13475 -- of generic associations, and add an explicit one to the original
13476 -- generic tree, through which a global actual can be preserved.
13477 -- Similarly, if a child unit is instantiated within a sibling, in the
13478 -- context of the parent, we must preserve the identifier of the parent
13479 -- so that it can be properly resolved in a subsequent instantiation.
13482 -- Apply Save_Global_References recursively to the descendents of the
13483 -- current node.
13486 -- This is the recursive procedure that does the work, once the
13487 -- enclosing generic scope has been established.
13489 ---------------
13490 -- Is_Global --
13491 ---------------
13497 -- Determine whether the parent node of a reference to a child unit
13498 -- denotes an instantiation or a formal package, in which case the
13499 -- reference to the child unit is global, even if it appears within
13500 -- the current scope (e.g. when the instance appears within the body
13501 -- of an ancestor).
13503 ----------------------
13504 -- Is_Instance_Node --
13505 ----------------------
13508 begin
13510 or else
13514 -- Start of processing for Is_Global
13516 begin
13527 and then
13529 then
13532 else
13537 else
13546 ------------------
13547 -- Reset_Entity --
13548 ------------------
13553 -- If the type of N2 is global to the generic unit, save the type in
13554 -- the generic node. Just as we perform name capture for explicit
13555 -- references within the generic, we must capture the global types
13556 -- of local entities because they may participate in resolution in
13557 -- the instance.
13560 -- Find the ultimate ancestor of the current unit. If it is not a
13561 -- generic unit, then the name of the current unit in the prefix of
13562 -- an expanded name must be replaced with its generic homonym to
13563 -- ensure that it will be properly resolved in an instance.
13565 ---------------------
13566 -- Set_Global_Type --
13567 ---------------------
13572 begin
13577 then
13578 -- If the entity of N is not the associated node, this is a
13579 -- nested generic and it has an associated node as well, whose
13580 -- type is already the full view (see below). Indicate that the
13581 -- original node has a private view.
13586 -- If not a private type, nothing else to do
13591 then
13595 -- If it is a derivation of a private type in a context where no
13596 -- full view is needed, nothing to do either.
13601 -- Otherwise mark the type for flipping and use the full view when
13602 -- available.
13604 else
13613 ------------------
13614 -- Top_Ancestor --
13615 ------------------
13620 begin
13629 -- Start of processing for Reset_Entity
13631 begin
13637 -- If the node is an entry call to an entry in an enclosing task,
13638 -- it is rewritten as a selected component. No global entity to
13639 -- preserve in this case, since the expansion will be redone in
13640 -- the instance.
13643 N_Defining_Character_Literal,
13644 N_Defining_Operator_Symbol)
13645 then
13651 -- If the entity is an itype created as a subtype of an access
13652 -- type with a null exclusion restore source entity for proper
13653 -- visibility. The itype will be created anew in the instance.
13659 then
13667 -- If the entity is a package renaming that is the prefix of
13668 -- an expanded name, it has been rewritten as the renamed
13669 -- package, which is necessary semantically but complicates
13670 -- ASIS tree traversal, so we recover the original entity to
13671 -- expose the renaming. Take into account that the context may
13672 -- be a nested generic, that the original node may itself have
13673 -- an associated node that had better be an entity, and that
13674 -- the current node is still a selected component.
13682 then
13688 else
13689 -- Renaming is local, and will be resolved in instance
13695 else
13702 or else
13705 then
13708 else
13709 -- Entity is local. Mark generic node as unresolved.
13710 -- Note that now it does not have an entity.
13718 then
13724 then
13731 -- If this is a reference to the current generic entity, replace
13732 -- by the name of the generic homonym of the current package. This
13733 -- is because in an instantiation Par.P.Q will not resolve to the
13734 -- name of the instance, whose enclosing scope is not necessarily
13735 -- Par. We use the generic homonym rather that the name of the
13736 -- generic itself because it may be hidden by a local declaration.
13739 and then not
13741 then
13745 Chars =>
13747 else
13756 then
13757 Save_Global_Defaults
13761 -- A selected component may denote a static constant that has been
13762 -- folded. If the static constant is global to the generic, capture
13763 -- its value. Otherwise the folding will happen in any instantiation.
13767 then
13770 then
13774 else
13778 -- A selected component may be transformed into a parameterless
13779 -- function call. If the called entity is global, rewrite the node
13780 -- appropriately, i.e. as an extended name for the global entity.
13785 then
13793 else
13799 -- In Ada 2005, X.F may be a call to a primitive operation,
13800 -- rewritten as F (X). This rewriting will be done again in an
13801 -- instance, so keep the original node. Global entities will be
13802 -- captured as for other constructs. Indicate that this must
13803 -- resolve as a call, to prevent accidental overloading in the
13804 -- instance, if both a component and a primitive operation appear
13805 -- as candidates.
13807 else
13811 -- Entity is local. Reset in generic unit, so that node is resolved
13812 -- anew at the point of instantiation.
13814 else
13820 -----------------------------
13821 -- Save_Entity_Descendants --
13822 -----------------------------
13825 begin
13846 --------------------------
13847 -- Save_Global_Defaults --
13848 --------------------------
13862 begin
13867 else
13875 else
13884 -- Find the associations added for default subprograms
13890 loop
13894 -- Add a similar association if the default is global. The
13895 -- renaming declaration for the actual has been analyzed, and
13896 -- its alias is the program it renames. Link the actual in the
13897 -- original generic tree with the node in the analyzed tree.
13903 -- Following test is defence against rubbish errors
13909 -- Retrieve the resolved actual from the renaming declaration
13910 -- created for the instantiated formal.
13917 Ndec :=
13920 Explicit_Generic_Actual_Parameter =>
13923 Set_Associated_Node
13928 -- If there are other defaults, add a dummy association in case
13929 -- there are other defaulted formals with the same name.
13932 Ndec :=
13949 then
13950 -- This is an instantiation of a child unit within a sibling, so
13951 -- that the generic parent is in scope. An eventual instance must
13952 -- occur within the scope of an instance of the parent. Make name
13953 -- in instance into an expanded name, to preserve the identifier
13954 -- of the parent, so it can be resolved subsequently.
13971 Set_Associated_Node
13978 ----------------------------
13979 -- Save_Global_Descendant --
13980 ----------------------------
13985 begin
13998 else
14006 -- Element list or other non-node field, nothing to do
14008 else
14013 ---------------------
14014 -- Save_References --
14015 ---------------------
14017 -- This is the recursive procedure that does the work once the enclosing
14018 -- generic scope has been established. We have to treat specially a
14019 -- number of node rewritings that are required by semantic processing
14020 -- and which change the kind of nodes in the generic copy: typically
14021 -- constant-folding, replacing an operator node by a string literal, or
14022 -- a selected component by an expanded name. In each of those cases, the
14023 -- transformation is propagated to the generic unit.
14028 begin
14038 then
14054 else
14055 -- Node may be transformed into call to a user-defined operator
14064 then
14066 else
14072 N_Real_Literal,
14073 N_String_Literal)
14074 then
14077 then
14079 -- Operation was constant-folded. Whenever possible,
14080 -- recover semantic information from unfolded node,
14081 -- for ASIS use.
14094 else
14095 -- If original node is already modified, propagate
14096 -- constant-folding to template.
14104 then
14105 -- Same if call was folded into a literal, but in this case
14106 -- retain the entity to avoid spurious ambiguities if it is
14107 -- overloaded at the point of instantiation or inlining.
14114 -- Complete operands check if node has not been constant-folded
14123 -- If this is a discriminant reference, always save it. It is
14124 -- used in the instance to find the corresponding discriminant
14125 -- positionally rather than by name.
14127 Set_Original_Discriminant
14131 else
14137 -- Name resolves to a call to parameterless function. If
14138 -- original entity is global, mark node as resolved.
14142 then
14144 else
14151 then
14152 -- Name resolves to named number that is constant-folded,
14153 -- We must preserve the original name for ASIS use, and
14154 -- undo the constant-folding, which will be repeated in
14155 -- each instance.
14162 -- Name resolves to string literal. Perform the same
14163 -- replacement in generic.
14169 -- An identifier is rewritten as a dereference if it is the
14170 -- prefix in an implicit dereference (call or attribute).
14171 -- The analysis of an instantiation will expand the node
14172 -- again, so we preserve the original tree but link it to
14173 -- the resolved entity in case it is global.
14178 then
14183 then
14187 Name =>
14189 Loc))));
14191 else
14196 -- The subtype mark of a nominally unconstrained object is
14197 -- rewritten as a subtype indication using the bounds of the
14198 -- expression. Recover the original subtype mark.
14202 then
14206 else
14214 else
14215 declare
14221 -- This code section is part of implementing an untyped tree
14222 -- traversal, so it needs direct access to node fields.
14224 begin
14230 else
14233 -- In an instance within a generic, use the name of the
14234 -- actual and not the original generic parameter. If the
14235 -- actual is global in the current generic it must be
14236 -- preserved for its instantiation.
14239 and then
14241 then
14250 -- If the aggregate is an actual in a call, it has been
14251 -- resolved in the current context, to some local type.
14252 -- The enclosing call may have been disambiguated by the
14253 -- aggregate, and this disambiguation might fail at
14254 -- instantiation time because the type to which the
14255 -- aggregate did resolve is not preserved. In order to
14256 -- preserve some of this information, we wrap the
14257 -- aggregate in a qualified expression, using the id of
14258 -- its type. For further disambiguation we qualify the
14259 -- type name with its scope (if visible) because both
14260 -- id's will have corresponding entities in an instance.
14261 -- This resolves most of the problems with missing type
14262 -- information on aggregates in instances.
14267 then
14270 Prefix =>
14272 Selector_Name =>
14274 else
14278 Qual :=
14294 -- All other cases than aggregates
14296 else
14306 -- If a node has aspects, references within their expressions must
14307 -- be saved separately, given they are not directly in the tree.
14310 declare
14313 begin
14326 -- Start of processing for Save_Global_References
14328 begin
14331 -- If the generic unit is a child unit, references to entities in the
14332 -- parent are treated as local, because they will be resolved anew in
14333 -- the context of the instance of the parent.
14337 loop
14344 --------------------------------------
14345 -- Set_Copied_Sloc_For_Inlined_Body --
14346 --------------------------------------
14349 begin
14353 ---------------------
14354 -- Set_Instance_Of --
14355 ---------------------
14358 begin
14364 --------------------
14365 -- Set_Next_Assoc --
14366 --------------------
14369 begin
14373 -------------------
14374 -- Start_Generic --
14375 -------------------
14378 begin
14379 -- ??? More things could be factored out in this routine.
14380 -- Should probably be done at a later stage.
14388 ----------------------
14389 -- Set_Instance_Env --
14390 ----------------------
14392 procedure Set_Instance_Env
14395 is
14400 begin
14401 -- Regardless of the current mode, predefined units are analyzed in the
14402 -- most current Ada mode, and earlier version Ada checks do not apply
14403 -- to predefined units. Nothing needs to be done for non-internal units.
14404 -- These are always analyzed in the current mode.
14406 if Is_Internal_File_Name
14409 then
14412 -- In Ada2012 we may want to enable assertions in an instance of a
14413 -- predefined unit, in which case we need to preserve the current
14414 -- setting for the Assertions_Enabled flag. This will become more
14415 -- critical when pre/postconditions are added to predefined units,
14416 -- as is already the case for some numeric libraries.
14422 -- SPARK_Mode for an instance is the one applicable at the point of
14423 -- instantiation.
14429 Current_Instantiated_Parent :=
14435 -----------------
14436 -- Switch_View --
14437 -----------------
14444 begin
14445 -- T may be private but its base type may have been exchanged through
14446 -- some other occurrence, in which case there is nothing to switch
14447 -- besides T itself. Note that a private dependent subtype of a private
14448 -- type might not have been switched even if the base type has been,
14449 -- because of the last branch of Check_Private_View (see comment there).
14467 -- We avoid flipping the subtype if the Etype of its full view is
14468 -- private because this would result in a malformed subtype. This
14469 -- occurs when the Etype of the subtype full view is the full view of
14470 -- the base type (and since the base types were just switched, the
14471 -- subtype is pointing to the wrong view). This is currently the case
14472 -- for tagged record types, access types (maybe more?) and needs to
14473 -- be resolved. ???
14477 then
14486 -----------------
14487 -- True_Parent --
14488 -----------------
14491 begin
14494 else
14499 -----------------------------
14500 -- Valid_Default_Attribute --
14501 -----------------------------
14512 begin
14525 when Attribute_Adjacent | Attribute_Ceiling | Attribute_Copy_Sign |
14526 Attribute_Floor | Attribute_Fraction | Attribute_Machine |
14527 Attribute_Model | Attribute_Remainder | Attribute_Rounding |
14528 Attribute_Unbiased_Rounding =>
14529 OK := Is_Fun
14533 when Attribute_Image | Attribute_Pred | Attribute_Succ |
14534 Attribute_Value | Attribute_Wide_Image |
14535 Attribute_Wide_Value =>
14553 Def);