------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- S E M _ C H 1 2 -- -- -- -- S p e c -- -- -- -- Copyright (C) 1992-2024, Free Software Foundation, Inc. -- -- -- -- GNAT is free software; you can redistribute it and/or modify it under -- -- terms of the GNU General Public License as published by the Free Soft- -- -- ware Foundation; either version 3, or (at your option) any later ver- -- -- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- -- for more details. You should have received a copy of the GNU General -- -- Public License distributed with GNAT; see file COPYING3. If not, go to -- -- http://www.gnu.org/licenses for a complete copy of the license. -- -- -- -- GNAT was originally developed by the GNAT team at New York University. -- -- Extensive contributions were provided by Ada Core Technologies Inc. -- -- -- ------------------------------------------------------------------------------ with Inline; use Inline; with Types; use Types; package Sem_Ch12 is procedure Analyze_Generic_Package_Declaration (N : Node_Id); procedure Analyze_Generic_Subprogram_Declaration (N : Node_Id); procedure Analyze_Package_Instantiation (N : Node_Id); procedure Analyze_Procedure_Instantiation (N : Node_Id); procedure Analyze_Function_Instantiation (N : Node_Id); procedure Analyze_Formal_Object_Declaration (N : Node_Id); procedure Analyze_Formal_Type_Declaration (N : Node_Id); procedure Analyze_Formal_Subprogram_Declaration (N : Node_Id); procedure Analyze_Formal_Package_Declaration (N : Node_Id); procedure Start_Generic; -- Must be invoked before starting to process a generic spec or body procedure End_Generic; -- Must be invoked just at the end of the end of the processing of a -- generic spec or body. procedure Check_Generic_Child_Unit (Gen_Id : Node_Id; Parent_Installed : in out Boolean); -- If the name of the generic unit in an instantiation or a renaming is a -- selected component, then the prefix may be an instance and the selector -- may designate a child unit. Retrieve the parent generic and search for -- the child unit that must be declared within. Similarly, if this is the -- name of a generic child unit within an instantiation of its own parent, -- retrieve the parent generic. If the parent is installed as a result of -- this call, then Parent_Installed is set True, otherwise Parent_Installed -- is unchanged by the call. function Copy_Generic_Node (N : Node_Id; Parent_Id : Node_Id; Instantiating : Boolean) return Node_Id; -- Copy the tree for a generic unit or its body. The unit is copied -- repeatedly: once to produce a copy on which semantic analysis of -- the generic is performed, and once for each instantiation. The tree -- being copied is not semantically analyzed, except that references to -- global entities are marked on terminal nodes. Note that this function -- copies any aspect specifications from the input node N to the returned -- node, as well as the setting of the Has_Aspects flag. function Get_Instance_Of (A : Entity_Id) return Entity_Id; -- Retrieve actual associated with given generic parameter. -- If A is uninstantiated or not a generic parameter, return A. function Get_Unit_Instantiation_Node (A : Entity_Id) return Node_Id; -- Given the entity of a unit that is an instantiation, retrieve the -- original instance node. This is used when loading the instantiations -- of the ancestors of a child generic that is being instantiated. procedure Instantiate_Package_Body (Body_Info : Pending_Body_Info; Inlined_Body : Boolean := False; Body_Optional : Boolean := False); -- Called after semantic analysis, to complete the instantiation of -- package instances. The flag Inlined_Body is set if the body is -- being instantiated on the fly for inlining purposes. -- -- The flag Body_Optional indicates that the call is for an instance -- that precedes the current instance in the same declarative part. -- This call is needed when instantiating a nested generic whose body -- is to be found in the body of an instance. Normally we instantiate -- package bodies only when they appear in the main unit, or when their -- contents are needed for a nested generic G. If unit U contains several -- instances I1, I2, etc. and I2 contains a nested generic, then when U -- appears in the context of some other unit P that contains an instance -- of G, we compile the body of I2, but not that of I1. However, when we -- compile U as the main unit, we compile both bodies. This will lead to -- link-time errors if the compilation of I1 generates public symbols, -- because those in I2 will receive different names in both cases. This -- forces us to analyze the body of I1 even when U is not the main unit. -- We don't want this additional mechanism to generate an error when the -- body of the generic for I1 is not present, and this is the reason for -- the presence of the flag Body_Optional, which is exchanged between the -- current procedure and Load_Parent_Of_Generic. procedure Instantiate_Subprogram_Body (Body_Info : Pending_Body_Info; Body_Optional : Boolean := False); -- Called after semantic analysis, to complete the instantiation of -- function and procedure instances. The flag Body_Optional has the -- same purpose as described for Instantiate_Package_Body. function Is_Abbreviated_Instance (E : Entity_Id) return Boolean; -- Return true if E is a package created for an abbreviated instantiation -- to check conformance between formal package and corresponding actual. function Need_Subprogram_Instance_Body (N : Node_Id; Subp : Entity_Id) return Boolean; -- If a subprogram instance is inlined, indicate that the body of it -- must be created, to be used in inlined calls by the back-end. The -- subprogram may be inlined because the generic itself carries the -- pragma, or because a pragma appears for the instance in the scope. -- of the instance. procedure Save_Global_References (Templ : Node_Id); -- Traverse the original generic unit, and capture all references to -- entities that are defined outside of the generic in the analyzed tree -- for the template. These references are copied into the original tree, -- so that they appear automatically in every instantiation. A critical -- invariant in this approach is that if an id in the generic resolves to -- a local entity, the corresponding id in the instance will resolve to -- the homologous entity in the instance, even though the enclosing context -- for resolution is different, as long as the global references have been -- captured as described here. -- Because instantiations can be nested, the environment of the instance, -- involving the actuals and other data structures, must be saved and -- restored in stack-like fashion. Front-end inlining also uses these -- structures for the management of private/full views. procedure Save_Global_References_In_Aspects (N : Node_Id); -- Save all global references found within the expressions of all aspects -- that appear on node N. procedure Set_Copied_Sloc_For_Inlined_Body (N : Node_Id; E : Entity_Id); -- This procedure is used when a subprogram body is inlined. This process -- shares the same circuitry as the creation of an instantiated copy of -- a generic template. The call to this procedure establishes a new source -- file entry representing the inlined body as an instantiation, marked as -- an inlined body (so that errout can distinguish cases for generating -- error messages, otherwise the treatment is identical). In this call -- N is the subprogram body and E is the defining identifier of the -- subprogram in question. The resulting Sloc adjustment factor is -- saved as part of the internal state of the Sem_Ch12 package for use -- in subsequent calls to copy nodes. procedure Set_Copied_Sloc_For_Inherited_Pragma (N : Node_Id; E : Entity_Id); -- This procedure is used when a class-wide pre- or postcondition is -- inherited. This process shares the same circuitry as the creation of -- an instantiated copy of a generic template. The call to this procedure -- establishes a new source file entry representing the inherited pragma -- as an instantiation, marked as an inherited pragma (so that errout can -- distinguish cases for generating error messages, otherwise the treatment -- is identical). In this call, N is the subprogram declaration from -- which the pragma is inherited and E is the defining identifier of -- the overriding subprogram (when the subprogram is redefined) or the -- defining identifier of the extension type (when the subprogram is -- inherited). The resulting Sloc adjustment factor is saved as part of the -- internal state of the Sem_Ch12 package for use in subsequent calls to -- copy nodes. procedure Adjust_Inherited_Pragma_Sloc (N : Node_Id); -- This procedure is used when a class-wide pre- or postcondition -- is inherited. It is called on each node of the pragma expression -- to adjust its sloc. These call should be preceded by a call to -- Set_Copied_Sloc_For_Inherited_Pragma that sets the required sloc -- adjustment. This is done directly, instead of using Copy_Generic_Node -- to copy nodes and adjust slocs, as Copy_Generic_Node expects a specific -- structure to be in place, which is not the case for inherited pragmas. procedure Save_Env (Gen_Unit : Entity_Id; Act_Unit : Entity_Id); -- Because instantiations can be nested, the compiler maintains a stack -- of environments that holds variables relevant to the current instance: -- most importantly Instantiated_Parent, Exchanged_Views, Hidden_Entities, -- and others (see full list in Instance_Env). procedure Restore_Env; -- After processing an instantiation, or aborting one because of semantic -- errors, remove the current Instantiation_Env from Instantation_Envs. package Instance_Context is -- If an entirely new context is entered (e.g., when Rtsfind invokes -- semantics on a new compilation unit), then the current contents of -- the generic renamings table must be saved and later restored. type Context (<>) is private; function Save_And_Reset return Context; -- Save the current context information, then reinitialize -- the current context, and finally return the saved value. procedure Restore (Saved : Context); -- Restore the context that was saved earlier. private type Binding_Pair is record Formal_Id : Entity_Id; Actual_Id : Entity_Id; end record; type Context is array (Natural range <>) of Binding_Pair; end Instance_Context; procedure Initialize; -- Initializes internal data structures procedure Check_Private_View (N : Node_Id); -- Check whether the type of a generic entity has a different view between -- the point of generic analysis and the point of instantiation. If the -- view has changed, then at the point of instantiation we restore the -- correct view to perform semantic analysis of the instance, and reset -- the current view after instantiation. The processing is driven by the -- current private status of the type of the node, and Has_Private_View, -- a flag that is set at the point of generic compilation. If view and -- flag are inconsistent then the type is updated appropriately. A second -- flag Has_Secondary_Private_View is used to update a second type related -- to this type if need be. -- -- This subprogram is used in Check_Generic_Actuals and Copy_Generic_Node, -- and is exported here for the purpose of front-end inlining (see Exp_Ch6. -- Expand_Inlined_Call.Process_Formals). end Sem_Ch12;