1------------------------------------------------------------------------------ 2-- -- 3-- GNAT COMPILER COMPONENTS -- 4-- -- 5-- E X P _ T S S -- 6-- -- 7-- S p e c -- 8-- -- 9-- Copyright (C) 1992-2015, 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 26-- Type Support Subprogram (TSS) handling 27 28with Namet; use Namet; 29with Types; use Types; 30 31package Exp_Tss is 32 33 -- A type support subprogram (TSS) is an internally generated function or 34 -- procedure that is associated with a particular type. Examples are the 35 -- implicit initialization procedure, and subprograms for the Input and 36 -- Output attributes. 37 38 -- A given TSS is either generated once at the point of the declaration of 39 -- the type, or it is generated as needed in clients, but only one copy is 40 -- required in any one generated object file. The choice between these two 41 -- possibilities is made on a TSS-by-TSS basis depending on the estimation 42 -- of how likely the TSS is to be used. Initialization procedures fall in 43 -- the first category, for example, since it is likely that any declared 44 -- type will be used in a context requiring initialization, but the stream 45 -- attributes use the second approach, since it is more likely that they 46 -- will not be used at all, or will only be used in one client in any case. 47 48 ------------------------- 49 -- Current Limitations -- 50 ------------------------- 51 52 -- In the current version of this package, only the case of generating a 53 -- TSS at the point of declaration of the type is accommodated. A clear 54 -- improvement would be to follow through with the full implementation 55 -- as described above, and also accommodate the requirement of generating 56 -- only one copy in a given object file. 57 58 -- For now, we deal with the local case by generating duplicate versions 59 -- of the TSS routine, which is clearly rather inefficient in space usage. 60 -- This is done by using Make_TSS_Name_Local to generate unique names 61 -- for the different instances of TSS routines in a given scope. 62 63 ---------------- 64 -- TSS Naming -- 65 ---------------- 66 67 -- A TSS is identified by its Chars name. The name has the form typXY or 68 -- typ_<serial>XY, where typ is the type name, and XY are two characters 69 -- that identify the particular TSS routine. A unique serial number is 70 -- included for the case where several local instances of the same TSS 71 -- must be generated (see discussion under Make_TSS_Name_Local). 72 73 -- The following codes are used to denote TSSs: 74 75 -- Note: When making additions to this list, make the corresponding change 76 -- to the list in snames.adb-tmpl. 77 78 type TSS_Name_Type is new String (1 .. 2); 79 subtype TNT is TSS_Name_Type; 80 81 TSS_Deep_Adjust : constant TNT := "DA"; -- Deep Adjust 82 TSS_Deep_Finalize : constant TNT := "DF"; -- Deep Finalize 83 TSS_Deep_Initialize : constant TNT := "DI"; -- Deep Initialize 84 TSS_Composite_Equality : constant TNT := "EQ"; -- Composite Equality 85 TSS_Finalize_Address : constant TNT := "FD"; -- Finalize Address 86 TSS_From_Any : constant TNT := "FA"; -- PolyORB/DSA From_Any 87 TSS_Init_Proc : constant TNT := "IP"; -- Initialization Procedure 88 TSS_CPP_Init_Proc : constant TNT := "IC"; -- Init C++ dispatch tables 89 TSS_RAS_Access : constant TNT := "RA"; -- RAS type access 90 TSS_RAS_Dereference : constant TNT := "RD"; -- RAS type dereference 91 TSS_Rep_To_Pos : constant TNT := "RP"; -- Rep to Pos conversion 92 TSS_Slice_Assign : constant TNT := "SA"; -- Slice assignment 93 TSS_Stream_Input : constant TNT := "SI"; -- Stream Input attribute 94 TSS_Stream_Output : constant TNT := "SO"; -- Stream Output attribute 95 TSS_Stream_Read : constant TNT := "SR"; -- Stream Read attribute 96 TSS_Stream_Write : constant TNT := "SW"; -- Stream Write attribute 97 TSS_To_Any : constant TNT := "TA"; -- PolyORB/DSA To_Any 98 TSS_TypeCode : constant TNT := "TC"; -- PolyORB/DSA TypeCode 99 100 -- The array below contains all valid TSS names 101 102 TSS_Names : constant array (Natural range <>) of TSS_Name_Type := 103 (TSS_Deep_Adjust, 104 TSS_Deep_Finalize, 105 TSS_Deep_Initialize, 106 TSS_Composite_Equality, 107 TSS_Finalize_Address, 108 TSS_From_Any, 109 TSS_Init_Proc, 110 TSS_CPP_Init_Proc, 111 TSS_RAS_Access, 112 TSS_RAS_Dereference, 113 TSS_Rep_To_Pos, 114 TSS_Slice_Assign, 115 TSS_Stream_Input, 116 TSS_Stream_Output, 117 TSS_Stream_Read, 118 TSS_Stream_Write, 119 TSS_To_Any, 120 TSS_TypeCode); 121 122 TSS_Null : constant TNT := " "; 123 -- Dummy entry used to indicated that this is not really a TSS 124 125 function Get_TSS_Name (E : Entity_Id) return TSS_Name_Type; 126 -- Given an entity, if it is a TSS, then return the corresponding TSS 127 -- name type, otherwise return TSS_Null. 128 129 function Make_TSS_Name 130 (Typ : Entity_Id; 131 Nam : TSS_Name_Type) return Name_Id; 132 -- Construct the name as described above for the given TSS routine 133 -- identified by Nam for the type identified by Typ. 134 135 function Make_TSS_Name_Local 136 (Typ : Entity_Id; 137 Nam : TSS_Name_Type) return Name_Id; 138 -- Similar to the above call, but a string of the form _nnn is inserted 139 -- before the TSS code suffix, where nnn is a unique serial number. This 140 -- is used when multiple instances of the same TSS routine may be 141 -- generated in the same scope (see also discussion above of current 142 -- limitations). 143 144 function Make_Init_Proc_Name (Typ : Entity_Id) return Name_Id; 145 -- Version for init procs, same as Make_TSS_Name (Typ, TSS_Init_Proc) 146 147 function Is_CPP_Init_Proc (E : Entity_Id) return Boolean; 148 -- Version for CPP init procs, same as Is_TSS (E, TSS_CPP_Init_Proc); 149 150 function Is_Init_Proc (E : Entity_Id) return Boolean; 151 -- Version for init procs, same as Is_TSS (E, TSS_Init_Proc); 152 153 function Is_TSS (E : Entity_Id; Nam : TSS_Name_Type) return Boolean; 154 -- Determines if given entity (E) is the name of a TSS identified by Nam 155 156 function Is_TSS (N : Name_Id; Nam : TSS_Name_Type) return Boolean; 157 -- Same test applied directly to a Name_Id value 158 159 ----------------------------------------- 160 -- TSS Data structures and Subprograms -- 161 ----------------------------------------- 162 163 -- The TSS's for a given type are stored in an element list associated with 164 -- the type, and referenced from the TSS_Elist field of the N_Freeze_Entity 165 -- node associated with the type (all types that need TSS's always need to 166 -- be explicitly frozen, so the N_Freeze_Entity node always exists). 167 168 function TSS (Typ : Entity_Id; Nam : TSS_Name_Type) return Entity_Id; 169 -- Finds the TSS with the given name associated with the given type 170 -- If no such TSS exists, then Empty is returned; 171 172 function TSS (Typ : Entity_Id; Nam : Name_Id) return Entity_Id; 173 -- Finds the TSS with the given name associated with the given type. If 174 -- no such TSS exists, then Empty is returned. 175 176 function Same_TSS (E1, E2 : Entity_Id) return Boolean; 177 -- Returns True if E1 and E2 are the same kind of TSS, even if the names 178 -- are different (i.e. if the names of E1 and E2 end with two upper case 179 -- letters that are the same). 180 181 procedure Set_TSS (Typ : Entity_Id; TSS : Entity_Id); 182 -- This procedure is used to install a newly created TSS. The second 183 -- argument is the entity for such a new TSS. This entity is placed in the 184 -- TSS list for the type given as the first argument, replacing an old 185 -- entry of the same name if one was present. The tree for the body of this 186 -- TSS, which is not analyzed yet, is placed in the actions field of the 187 -- freeze node for the type. All such bodies are inserted into the main 188 -- tree and analyzed at the point at which the freeze node itself is 189 -- expanded. 190 191 procedure Copy_TSS (TSS : Entity_Id; Typ : Entity_Id); 192 -- Given an existing TSS for another type (which is already installed, 193 -- analyzed and expanded), install it as the corresponding TSS for Typ. 194 -- Note that this just copies a reference, not the tree. This can also be 195 -- used to initially install a TSS in the case where the subprogram for the 196 -- TSS has already been created and its declaration processed. 197 198 function CPP_Init_Proc (Typ : Entity_Id) return Entity_Id; 199 -- Obtains the CPP_Init TSS entity the given type. The CPP_Init TSS is a 200 -- procedure used to initialize the C++ part of the primary and secondary 201 -- dispatch tables of a tagged type derived from CPP types. 202 203 function Init_Proc 204 (Typ : Entity_Id; 205 Ref : Entity_Id := Empty) return Entity_Id; 206 -- Obtains the _init TSS entry for the given type. This function call is 207 -- equivalent to TSS (Typ, Name_uInit). The _init TSS is the procedure 208 -- used to initialize otherwise uninitialized instances of a type. If 209 -- there is no _init TSS, then the type requires no initialization. Note 210 -- that subtypes and implicit types never have an _init TSS since subtype 211 -- objects are always initialized using the initialization procedure for 212 -- the corresponding base type (see Base_Init_Proc function). A special 213 -- case arises for concurrent types. Such types do not themselves have an 214 -- init proc TSS, but initialization is required. The init proc used is 215 -- the one for the corresponding record type (see Base_Init_Proc). If 216 -- Ref is present it is a call to a subprogram whose profile matches the 217 -- profile of the required constructor (this argument is used to handle 218 -- non-default CPP constructors). 219 220 function Base_Init_Proc 221 (Typ : Entity_Id; 222 Ref : Entity_Id := Empty) return Entity_Id; 223 -- Obtains the _Init TSS entry from the base type of the entity, and also 224 -- deals with going indirect through the Corresponding_Record_Type field 225 -- for concurrent objects (which are initialized with the initialization 226 -- routine for the corresponding record type). Returns Empty if there is no 227 -- _Init TSS entry for the base type. If Ref is present it is a call to a 228 -- subprogram whose profile matches the profile of the required constructor 229 -- (this argument is used to handle non-default CPP constructors). 230 231 procedure Set_Init_Proc (Typ : Entity_Id; Init : Entity_Id); 232 pragma Inline (Set_Init_Proc); 233 -- The second argument is the _init TSS to be established for the type 234 -- given as the first argument. Equivalent to Set_TSS (Typ, Init). 235 236 function Has_Non_Null_Base_Init_Proc (Typ : Entity_Id) return Boolean; 237 -- Returns true if the given type has a defined Base_Init_Proc and 238 -- this init proc is not a null init proc (null init procs occur as 239 -- a result of the processing for Initialize_Scalars). This function 240 -- is used to test for the presence of an init proc in cases where 241 -- a null init proc is considered equivalent to no init proc. 242 243 function Find_Inherited_TSS 244 (Typ : Entity_Id; 245 Nam : TSS_Name_Type) return Entity_Id; 246 -- Returns the TSS of name Nam of Typ, or of its closest ancestor defining 247 -- such a TSS. Empty is returned is neither Typ nor any of its ancestors 248 -- have such a TSS. 249 250end Exp_Tss; 251