1------------------------------------------------------------------------------ 2-- -- 3-- GNAT COMPILER COMPONENTS -- 4-- -- 5-- S E M _ C H 1 2 -- 6-- -- 7-- S p e c -- 8-- -- 9-- Copyright (C) 1992-2013, 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------------------------------------------------------------------------------ 25 26with Inline; use Inline; 27with Types; use Types; 28 29package Sem_Ch12 is 30 procedure Analyze_Generic_Package_Declaration (N : Node_Id); 31 procedure Analyze_Generic_Subprogram_Declaration (N : Node_Id); 32 procedure Analyze_Package_Instantiation (N : Node_Id); 33 procedure Analyze_Procedure_Instantiation (N : Node_Id); 34 procedure Analyze_Function_Instantiation (N : Node_Id); 35 procedure Analyze_Formal_Object_Declaration (N : Node_Id); 36 procedure Analyze_Formal_Type_Declaration (N : Node_Id); 37 procedure Analyze_Formal_Subprogram_Declaration (N : Node_Id); 38 procedure Analyze_Formal_Package_Declaration (N : Node_Id); 39 40 procedure Start_Generic; 41 -- Must be invoked before starting to process a generic spec or body 42 43 procedure End_Generic; 44 -- Must be invoked just at the end of the end of the processing of a 45 -- generic spec or body. 46 47 procedure Check_Generic_Child_Unit 48 (Gen_Id : Node_Id; 49 Parent_Installed : in out Boolean); 50 -- If the name of the generic unit in an instantiation or a renaming is a 51 -- selected component, then the prefix may be an instance and the selector 52 -- may designate a child unit. Retrieve the parent generic and search for 53 -- the child unit that must be declared within. Similarly, if this is the 54 -- name of a generic child unit within an instantiation of its own parent, 55 -- retrieve the parent generic. If the parent is installed as a result of 56 -- this call, then Parent_Installed is set True, otherwise Parent_Installed 57 -- is unchanged by the call. 58 59 function Copy_Generic_Node 60 (N : Node_Id; 61 Parent_Id : Node_Id; 62 Instantiating : Boolean) return Node_Id; 63 -- Copy the tree for a generic unit or its body. The unit is copied 64 -- repeatedly: once to produce a copy on which semantic analysis of 65 -- the generic is performed, and once for each instantiation. The tree 66 -- being copied is not semantically analyzed, except that references to 67 -- global entities are marked on terminal nodes. Note that this function 68 -- copies any aspect specifications from the input node N to the returned 69 -- node, as well as the setting of the Has_Aspects flag. 70 71 function Get_Instance_Of (A : Entity_Id) return Entity_Id; 72 -- Retrieve actual associated with given generic parameter. 73 -- If A is uninstantiated or not a generic parameter, return A. 74 75 function Get_Package_Instantiation_Node (A : Entity_Id) return Node_Id; 76 -- Given the entity of a unit that is an instantiation, retrieve the 77 -- original instance node. This is used when loading the instantiations 78 -- of the ancestors of a child generic that is being instantiated. 79 80 procedure Instantiate_Package_Body 81 (Body_Info : Pending_Body_Info; 82 Inlined_Body : Boolean := False; 83 Body_Optional : Boolean := False); 84 -- Called after semantic analysis, to complete the instantiation of 85 -- package instances. The flag Inlined_Body is set if the body is 86 -- being instantiated on the fly for inlined purposes. 87 -- 88 -- The flag Body_Optional indicates that the call is for an instance 89 -- that precedes the current instance in the same declarative part. 90 -- This call is needed when instantiating a nested generic whose body 91 -- is to be found in the body of an instance. Normally we instantiate 92 -- package bodies only when they appear in the main unit, or when their 93 -- contents are needed for a nested generic G. If unit U contains several 94 -- instances I1, I2, etc. and I2 contains a nested generic, then when U 95 -- appears in the context of some other unit P that contains an instance 96 -- of G, we compile the body of I2, but not that of I1. However, when we 97 -- compile U as the main unit, we compile both bodies. This will lead to 98 -- lead to link-time errors if the compilation of I1 generates public 99 -- symbols, because those in I2 will receive different names in both 100 -- cases. This forces us to analyze the body of I1 even when U is not the 101 -- main unit. We don't want this additional mechanism to generate an error 102 -- when the body of the generic for I1 is not present, and this is the 103 -- reason for the presence of the flag Body_Optional, which is exchanged 104 -- between the current procedure and Load_Parent_Of_Generic. 105 106 procedure Instantiate_Subprogram_Body 107 (Body_Info : Pending_Body_Info; 108 Body_Optional : Boolean := False); 109 -- Called after semantic analysis, to complete the instantiation of 110 -- function and procedure instances. The flag Body_Optional has the 111 -- same purpose as described for Instantiate_Package_Body. 112 113 function Need_Subprogram_Instance_Body 114 (N : Node_Id; 115 Subp : Entity_Id) return Boolean; 116 -- If a subprogram instance is inlined, indicate that the body of it 117 -- must be created, to be used in inlined calls by the back-end. The 118 -- subprogram may be inlined because the generic itself carries the 119 -- pragma, or because a pragma appears for the instance in the scope. 120 -- of the instance. 121 122 procedure Save_Global_References (N : Node_Id); 123 -- Traverse the original generic unit, and capture all references to 124 -- entities that are defined outside of the generic in the analyzed 125 -- tree for the template. These references are copied into the original 126 -- tree, so that they appear automatically in every instantiation. 127 -- A critical invariant in this approach is that if an id in the generic 128 -- resolves to a local entity, the corresponding id in the instance 129 -- will resolve to the homologous entity in the instance, even though 130 -- the enclosing context for resolution is different, as long as the 131 -- global references have been captured as described here. 132 133 -- Because instantiations can be nested, the environment of the instance, 134 -- involving the actuals and other data-structures, must be saved and 135 -- restored in stack-like fashion. Front-end inlining also uses these 136 -- structures for the management of private/full views. 137 138 procedure Set_Copied_Sloc_For_Inlined_Body (N : Node_Id; E : Entity_Id); 139 -- This procedure is used when a subprogram body is inlined. This process 140 -- shares the same circuitry as the creation of an instantiated copy of 141 -- a generic template. The call to this procedure establishes a new source 142 -- file entry representing the inlined body as an instantiation, marked as 143 -- an inlined body (so that errout can distinguish cases for generating 144 -- error messages, otherwise the treatment is identical). In this call 145 -- N is the subprogram body and E is the defining identifier of the 146 -- subprogram in question. The resulting Sloc adjustment factor is 147 -- saved as part of the internal state of the Sem_Ch12 package for use 148 -- in subsequent calls to copy nodes. 149 150 procedure Save_Env 151 (Gen_Unit : Entity_Id; 152 Act_Unit : Entity_Id); 153 -- Because instantiations can be nested, the compiler maintains a stack 154 -- of environments that holds variables relevant to the current instance: 155 -- most importanty Instantiated_Parent, Exchanged_Views, Hidden_Entities, 156 -- and others (see full list in Instance_Env). 157 158 procedure Restore_Env; 159 -- After processing an instantiation, or aborting one because of semantic 160 -- errors, remove the current Instantiation_Env from Instantation_Envs. 161 162 procedure Initialize; 163 -- Initializes internal data structures 164 165 procedure Check_Private_View (N : Node_Id); 166 -- Check whether the type of a generic entity has a different view between 167 -- the point of generic analysis and the point of instantiation. If the 168 -- view has changed, then at the point of instantiation we restore the 169 -- correct view to perform semantic analysis of the instance, and reset 170 -- the current view after instantiation. The processing is driven by the 171 -- current private status of the type of the node, and Has_Private_View, 172 -- a flag that is set at the point of generic compilation. If view and 173 -- flag are inconsistent then the type is updated appropriately. 174 -- 175 -- This subprogram is used in Check_Generic_Actuals and Copy_Generic_Node, 176 -- and is exported here for the purpose of front-end inlining (see Exp_Ch6. 177 -- Expand_Inlined_Call.Process_Formals). 178 179end Sem_Ch12; 180