1------------------------------------------------------------------------------ 2-- -- 3-- GNAT COMPILER COMPONENTS -- 4-- -- 5-- S E M _ C H 3 -- 6-- -- 7-- S p e c -- 8-- -- 9-- Copyright (C) 1992-2020, 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 Types; use Types; 27 28package Sem_Ch3 is 29 procedure Analyze_Component_Declaration (N : Node_Id); 30 procedure Analyze_Full_Type_Declaration (N : Node_Id); 31 procedure Analyze_Incomplete_Type_Decl (N : Node_Id); 32 procedure Analyze_Itype_Reference (N : Node_Id); 33 procedure Analyze_Number_Declaration (N : Node_Id); 34 procedure Analyze_Object_Declaration (N : Node_Id); 35 procedure Analyze_Others_Choice (N : Node_Id); 36 procedure Analyze_Private_Extension_Declaration (N : Node_Id); 37 procedure Analyze_Subtype_Indication (N : Node_Id); 38 procedure Analyze_Variant_Part (N : Node_Id); 39 40 procedure Analyze_Subtype_Declaration 41 (N : Node_Id; 42 Skip : Boolean := False); 43 -- Called to analyze a subtype declaration. The parameter Skip is used for 44 -- Ada 2005 (AI-412). We set to True in order to avoid reentering the 45 -- defining identifier of N when analyzing a rewritten incomplete subtype 46 -- declaration. 47 48 function Access_Definition 49 (Related_Nod : Node_Id; 50 N : Node_Id) return Entity_Id; 51 -- An access definition defines a general access type for a formal 52 -- parameter. The procedure is called when processing formals, when the 53 -- current scope is the subprogram. The Implicit type is attached to the 54 -- Related_Nod put into the enclosing scope, so that the only entities 55 -- defined in the spec are the formals themselves. 56 57 procedure Access_Subprogram_Declaration 58 (T_Name : Entity_Id; 59 T_Def : Node_Id); 60 -- The subprogram specification yields the signature of an implicit 61 -- type, whose Ekind is Access_Subprogram_Type. This implicit type is the 62 -- designated type of the declared access type. In subprogram calls, the 63 -- signature of the implicit type works like the profile of a regular 64 -- subprogram. 65 66 procedure Add_Internal_Interface_Entities (Tagged_Type : Entity_Id); 67 -- Add to the list of primitives of Tagged_Type the internal entities 68 -- associated with covered interface primitives. These entities link the 69 -- interface primitives with the tagged type primitives that cover them. 70 71 procedure Analyze_Declarations (L : List_Id); 72 -- Called to analyze a list of declarations (in what context ???). Also 73 -- performs necessary freezing actions (more description needed ???) 74 75 procedure Analyze_Interface_Declaration (T : Entity_Id; Def : Node_Id); 76 -- Analyze an interface declaration or a formal interface declaration 77 78 procedure Array_Type_Declaration (T : in out Entity_Id; Def : Node_Id); 79 -- Process an array type declaration. If the array is constrained, we 80 -- create an implicit parent array type, with the same index types and 81 -- component type. 82 83 procedure Access_Type_Declaration (T : Entity_Id; Def : Node_Id); 84 -- Process an access type declaration 85 86 procedure Build_Itype_Reference (Ityp : Entity_Id; Nod : Node_Id); 87 -- Create a reference to an internal type, for use by Gigi. The back-end 88 -- elaborates itypes on demand, i.e. when their first use is seen. This can 89 -- lead to scope anomalies if the first use is within a scope that is 90 -- nested within the scope that contains the point of definition of the 91 -- itype. The Itype_Reference node forces the elaboration of the itype 92 -- in the proper scope. The node is inserted after Nod, which is the 93 -- enclosing declaration that generated Ityp. 94 -- 95 -- A related mechanism is used during expansion, for itypes created in 96 -- branches of conditionals. See Ensure_Defined in exp_util. Could both 97 -- mechanisms be merged ??? 98 99 procedure Check_Abstract_Overriding (T : Entity_Id); 100 -- Check that all abstract subprograms inherited from T's parent type have 101 -- been overridden as required, and that nonabstract subprograms have not 102 -- been incorrectly overridden with an abstract subprogram. 103 104 procedure Check_Aliased_Component_Types (T : Entity_Id); 105 -- Given an array type or record type T, check that if the type is 106 -- nonlimited, then the nominal subtype of any components of T that 107 -- have discriminants must be constrained. 108 109 procedure Check_Completion (Body_Id : Node_Id := Empty); 110 -- At the end of a declarative part, verify that all entities that require 111 -- completion have received one. If Body_Id is absent, the error indicating 112 -- a missing completion is placed on the declaration that needs completion. 113 -- If Body_Id is present, it is the defining identifier of a package body, 114 -- and errors are posted on that node, rather than on the declarations that 115 -- require completion in the package declaration. 116 117 procedure Check_CPP_Type_Has_No_Defaults (T : Entity_Id); 118 -- Check that components of imported CPP type T do not have default 119 -- expressions because the constructor (if any) is on the C++ side. 120 121 procedure Derive_Subprogram 122 (New_Subp : out Entity_Id; 123 Parent_Subp : Entity_Id; 124 Derived_Type : Entity_Id; 125 Parent_Type : Entity_Id; 126 Actual_Subp : Entity_Id := Empty); 127 -- Derive the subprogram Parent_Subp from Parent_Type, and replace the 128 -- subsidiary subtypes with the derived type to build the specification of 129 -- the inherited subprogram (returned in New_Subp). For tagged types, the 130 -- derived subprogram is aliased to that of the actual (in the case where 131 -- Actual_Subp is nonempty) rather than to the corresponding subprogram of 132 -- the parent type. 133 134 procedure Derive_Subprograms 135 (Parent_Type : Entity_Id; 136 Derived_Type : Entity_Id; 137 Generic_Actual : Entity_Id := Empty); 138 -- To complete type derivation, collect/retrieve the primitive operations 139 -- of the parent type, and replace the subsidiary subtypes with the derived 140 -- type, to build the specs of the inherited ops. For generic actuals, the 141 -- mapping of the primitive operations to those of the parent type is also 142 -- done by rederiving the operations within the instance. For tagged types, 143 -- the derived subprograms are aliased to those of the actual, not those of 144 -- the ancestor. 145 -- 146 -- Note: one might expect this to be private to the package body, but there 147 -- is one rather unusual usage in package Exp_Dist. 148 149 function Find_Hidden_Interface 150 (Src : Elist_Id; 151 Dest : Elist_Id) return Entity_Id; 152 -- Ada 2005: Determine whether the interfaces in list Src are all present 153 -- in the list Dest. Return the first differing interface, or Empty 154 -- otherwise. 155 156 function Find_Type_Of_Subtype_Indic (S : Node_Id) return Entity_Id; 157 -- Given a subtype indication S (which is really an N_Subtype_Indication 158 -- node or a plain N_Identifier), find the type of the subtype mark. 159 160 function Find_Type_Name (N : Node_Id) return Entity_Id; 161 -- Enter the identifier in a type definition, or find the entity already 162 -- declared, in the case of the full declaration of an incomplete or 163 -- private type. If the previous declaration is tagged then the class-wide 164 -- entity is propagated to the identifier to prevent multiple incompatible 165 -- class-wide types that may be created for self-referential anonymous 166 -- access components. 167 168 function Get_Discriminant_Value 169 (Discriminant : Entity_Id; 170 Typ_For_Constraint : Entity_Id; 171 Constraint : Elist_Id) return Node_Id; 172 -- ??? MORE DOCUMENTATION 173 -- Given a discriminant somewhere in the Typ_For_Constraint tree and a 174 -- Constraint, return the value of that discriminant. 175 176 function Is_Null_Extension (T : Entity_Id) return Boolean; 177 -- Returns True if the tagged type T has an N_Full_Type_Declaration that 178 -- is a null extension, meaning that it has an extension part without any 179 -- components and does not have a known discriminant part. 180 181 function Is_Visible_Component 182 (C : Entity_Id; 183 N : Node_Id := Empty) return Boolean; 184 -- Determines if a record component C is visible in the present context. 185 -- Note that even though component C could appear in the entity chain of a 186 -- record type, C may not be visible in the current context. For instance, 187 -- C may be a component inherited in the full view of a private extension 188 -- which is not visible in the current context. 189 -- 190 -- If present, N is the selected component of which C is the selector. If 191 -- the prefix of N is a type conversion inserted for a discriminant check, 192 -- C is automatically visible. 193 194 procedure Make_Index 195 (N : Node_Id; 196 Related_Nod : Node_Id; 197 Related_Id : Entity_Id := Empty; 198 Suffix_Index : Pos := 1); 199 -- Process an index that is given in an array declaration, an entry 200 -- family declaration or a loop iteration. The index is given by an index 201 -- declaration (a 'box'), or by a discrete range. The later can be the name 202 -- of a discrete type, or a subtype indication. 203 -- 204 -- Related_Nod is the node where the potential generated implicit types 205 -- will be inserted. The next last parameters are used for creating the 206 -- name. 207 208 procedure Make_Class_Wide_Type (T : Entity_Id); 209 -- A Class_Wide_Type is created for each tagged type definition. The 210 -- attributes of a class-wide type are inherited from those of the type T. 211 -- If T is introduced by a private declaration, the corresponding class 212 -- wide type is created at the same time, and therefore there is a private 213 -- and a full declaration for the class-wide type as well. 214 215 function OK_For_Limited_Init_In_05 216 (Typ : Entity_Id; 217 Exp : Node_Id) return Boolean; 218 -- Presuming Exp is an expression of an inherently limited type Typ, 219 -- returns True if the expression is allowed in an initialization context 220 -- by the rules of Ada 2005. We use the rule in RM-7.5(2.1/2), "...it is an 221 -- aggregate, a function_call, or a parenthesized expression or qualified 222 -- expression whose operand is permitted...". Note that in Ada 95 mode, 223 -- we sometimes wish to give warnings based on whether the program _would_ 224 -- be legal in Ada 2005. Note that Exp must already have been resolved, 225 -- so we can know whether it's a function call (as opposed to an indexed 226 -- component, for example). In the case where Typ is a limited interface's 227 -- class-wide type, then the expression is allowed to be of any kind if its 228 -- type is a nonlimited descendant of the interface. 229 230 function OK_For_Limited_Init 231 (Typ : Entity_Id; 232 Exp : Node_Id) return Boolean; 233 -- Always False in Ada 95 mode. Equivalent to OK_For_Limited_Init_In_05 in 234 -- Ada 2005 mode. 235 236 procedure Preanalyze_Assert_Expression (N : Node_Id; T : Entity_Id); 237 -- Wrapper on Preanalyze_Spec_Expression for assertion expressions, so that 238 -- In_Assertion_Expr can be properly adjusted. 239 240 procedure Preanalyze_Spec_Expression (N : Node_Id; T : Entity_Id); 241 -- Default and per object expressions do not freeze their components, and 242 -- must be analyzed and resolved accordingly. The analysis is done by 243 -- calling the Preanalyze_And_Resolve routine and setting the global 244 -- In_Spec_Expression flag. See the documentation section entitled 245 -- "Handling of Default and Per-Object Expressions" in sem.ads for full 246 -- details. N is the expression to be analyzed, T is the expected type. 247 -- This mechanism is also used for aspect specifications that have an 248 -- expression parameter that needs similar preanalysis. 249 250 procedure Process_Full_View (N : Node_Id; Full_T, Priv_T : Entity_Id); 251 -- Process some semantic actions when the full view of a private type is 252 -- encountered and analyzed. The first action is to create the full views 253 -- of the dependant private subtypes. The second action is to recopy the 254 -- primitive operations of the private view (in the tagged case). 255 -- N is the N_Full_Type_Declaration node. 256 -- 257 -- Full_T is the full view of the type whose full declaration is in N. 258 -- 259 -- Priv_T is the private view of the type whose full declaration is in N. 260 261 procedure Process_Range_Expr_In_Decl 262 (R : Node_Id; 263 T : Entity_Id; 264 Subtyp : Entity_Id := Empty; 265 Check_List : List_Id := No_List; 266 R_Check_Off : Boolean := False); 267 -- Process a range expression that appears in a declaration context. The 268 -- range is analyzed and resolved with the base type of the given type, and 269 -- an appropriate check for expressions in non-static contexts made on the 270 -- bounds. R is analyzed and resolved using T, so the caller should if 271 -- necessary link R into the tree before the call, and in particular in the 272 -- case of a subtype declaration, it is appropriate to set the parent 273 -- pointer of R so that the types get properly frozen. Check_List is used 274 -- when the subprogram is called from Build_Record_Init_Proc and is used to 275 -- return a set of constraint checking statements generated by the Checks 276 -- package. R_Check_Off is set to True when the call to Range_Check is to 277 -- be skipped. 278 -- 279 -- If Subtyp is given, then the range is for the named subtype Subtyp, and 280 -- in this case the bounds are captured if necessary using this name. 281 282 function Process_Subtype 283 (S : Node_Id; 284 Related_Nod : Node_Id; 285 Related_Id : Entity_Id := Empty; 286 Suffix : Character := ' ') return Entity_Id; 287 -- Process a subtype indication S and return corresponding entity. 288 -- Related_Nod is the node where the potential generated implicit types 289 -- will be inserted. The Related_Id and Suffix parameters are used to 290 -- build the associated Implicit type name. 291 292 procedure Process_Discriminants 293 (N : Node_Id; 294 Prev : Entity_Id := Empty); 295 -- Process the discriminants contained in an N_Full_Type_Declaration or 296 -- N_Incomplete_Type_Decl node N. If the declaration is a completion, Prev 297 -- is entity on the partial view, on which references are posted. However, 298 -- note that Process_Discriminants is called for a completion only if 299 -- partial view had no discriminants (else we just check conformance 300 -- between the two views and do not call Process_Discriminants again 301 -- for the completion). 302 303 function Replace_Anonymous_Access_To_Protected_Subprogram 304 (N : Node_Id) return Entity_Id; 305 -- Ada 2005 (AI-254): Create and decorate an internal full type declaration 306 -- for an anonymous access to protected subprogram. For a record component 307 -- declaration, the type is created in the enclosing scope, for an array 308 -- type declaration or an object declaration it is simply placed ahead of 309 -- this declaration. 310 311 procedure Set_Completion_Referenced (E : Entity_Id); 312 -- If E is the completion of a private or incomplete type declaration, 313 -- or the completion of a deferred constant declaration, mark the entity 314 -- as referenced. Warnings on unused entities, if needed, go on the 315 -- partial view. 316 317end Sem_Ch3; 318