1------------------------------------------------------------------------------ 2-- -- 3-- GNAT COMPILER COMPONENTS -- 4-- -- 5-- S E M _ C H 3 -- 6-- -- 7-- S p e c -- 8-- -- 9-- Copyright (C) 1992-2013, 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 Nlists; use Nlists; 27with Types; use Types; 28 29package Sem_Ch3 is 30 procedure Analyze_Component_Declaration (N : Node_Id); 31 procedure Analyze_Full_Type_Declaration (N : Node_Id); 32 procedure Analyze_Incomplete_Type_Decl (N : Node_Id); 33 procedure Analyze_Itype_Reference (N : Node_Id); 34 procedure Analyze_Number_Declaration (N : Node_Id); 35 procedure Analyze_Object_Declaration (N : Node_Id); 36 procedure Analyze_Others_Choice (N : Node_Id); 37 procedure Analyze_Private_Extension_Declaration (N : Node_Id); 38 procedure Analyze_Subtype_Indication (N : Node_Id); 39 procedure Analyze_Variant_Part (N : Node_Id); 40 41 procedure Analyze_Subtype_Declaration 42 (N : Node_Id; 43 Skip : Boolean := False); 44 -- Called to analyze a subtype declaration. The parameter Skip is used for 45 -- Ada 2005 (AI-412). We set to True in order to avoid reentering the 46 -- defining identifier of N when analyzing a rewritten incomplete subtype 47 -- declaration. 48 49 function Access_Definition 50 (Related_Nod : Node_Id; 51 N : Node_Id) return Entity_Id; 52 -- An access definition defines a general access type for a formal 53 -- parameter. The procedure is called when processing formals, when 54 -- the current scope is the subprogram. The Implicit type is attached 55 -- to the Related_Nod put into the enclosing scope, so that the only 56 -- entities defined in the spec are the formals themselves. 57 58 procedure Access_Subprogram_Declaration 59 (T_Name : Entity_Id; 60 T_Def : Node_Id); 61 -- The subprogram specification yields the signature of an implicit 62 -- type, whose Ekind is Access_Subprogram_Type. This implicit type is 63 -- the designated type of the declared access type. In subprogram calls, 64 -- the signature of the implicit type works like the profile of a regular 65 -- subprogram. 66 67 procedure Add_Internal_Interface_Entities (Tagged_Type : Entity_Id); 68 -- Add to the list of primitives of Tagged_Type the internal entities 69 -- associated with covered interface primitives. These entities link the 70 -- interface primitives with the tagged type primitives that cover them. 71 72 procedure Analyze_Declarations (L : List_Id); 73 -- Called to analyze a list of declarations (in what context ???). Also 74 -- performs necessary freezing actions (more description needed ???) 75 76 procedure Analyze_Interface_Declaration (T : Entity_Id; Def : Node_Id); 77 -- Analyze an interface declaration or a formal interface declaration 78 79 procedure Array_Type_Declaration (T : in out Entity_Id; Def : Node_Id); 80 -- Process an array type declaration. If the array is constrained, we 81 -- create an implicit parent array type, with the same index types and 82 -- component type. 83 84 procedure Access_Type_Declaration (T : Entity_Id; Def : Node_Id); 85 -- Process an access type declaration 86 87 procedure Build_Itype_Reference (Ityp : Entity_Id; Nod : Node_Id); 88 -- Create a reference to an internal type, for use by Gigi. The back-end 89 -- elaborates itypes on demand, i.e. when their first use is seen. This can 90 -- lead to scope anomalies if the first use is within a scope that is 91 -- nested within the scope that contains the point of definition of the 92 -- itype. The Itype_Reference node forces the elaboration of the itype 93 -- in the proper scope. The node is inserted after Nod, which is the 94 -- enclosing declaration that generated Ityp. 95 -- 96 -- A related mechanism is used during expansion, for itypes created in 97 -- branches of conditionals. See Ensure_Defined in exp_util. 98 -- Could both mechanisms be merged ??? 99 100 procedure Check_Abstract_Overriding (T : Entity_Id); 101 -- Check that all abstract subprograms inherited from T's parent type have 102 -- been overridden as required, and that nonabstract subprograms have not 103 -- been incorrectly overridden with an abstract subprogram. 104 105 procedure Check_Aliased_Component_Types (T : Entity_Id); 106 -- Given an array type or record type T, check that if the type is 107 -- nonlimited, then the nominal subtype of any components of T that 108 -- have discriminants must be constrained. 109 110 procedure Check_Completion (Body_Id : Node_Id := Empty); 111 -- At the end of a declarative part, verify that all entities that require 112 -- completion have received one. If Body_Id is absent, the error indicating 113 -- a missing completion is placed on the declaration that needs completion. 114 -- If Body_Id is present, it is the defining identifier of a package body, 115 -- and errors are posted on that node, rather than on the declarations that 116 -- require completion in the package declaration. 117 118 procedure Check_CPP_Type_Has_No_Defaults (T : Entity_Id); 119 -- Check that components of imported CPP type T do not have default 120 -- expressions because the constructor (if any) is on the C++ side. 121 122 procedure Derive_Subprogram 123 (New_Subp : in out Entity_Id; 124 Parent_Subp : Entity_Id; 125 Derived_Type : Entity_Id; 126 Parent_Type : Entity_Id; 127 Actual_Subp : Entity_Id := Empty); 128 -- Derive the subprogram Parent_Subp from Parent_Type, and replace the 129 -- subsidiary subtypes with the derived type to build the specification 130 -- of the inherited subprogram (returned in New_Subp). For tagged types, 131 -- the derived subprogram is aliased to that of the actual (in the 132 -- case where Actual_Subp is nonempty) rather than to the corresponding 133 -- subprogram of the parent type. 134 135 procedure Derive_Subprograms 136 (Parent_Type : Entity_Id; 137 Derived_Type : Entity_Id; 138 Generic_Actual : Entity_Id := Empty); 139 -- To complete type derivation, collect/retrieve the primitive operations 140 -- of the parent type, and replace the subsidiary subtypes with the derived 141 -- type, to build the specs of the inherited ops. For generic actuals, the 142 -- mapping of the primitive operations to those of the parent type is also 143 -- done by rederiving the operations within the instance. For tagged types, 144 -- the derived subprograms are aliased to those of the actual, not those of 145 -- the ancestor. 146 -- 147 -- Note: one might expect this to be private to the package body, but there 148 -- is one rather unusual usage in package Exp_Dist. 149 150 function Find_Hidden_Interface 151 (Src : Elist_Id; 152 Dest : Elist_Id) return Entity_Id; 153 -- Ada 2005: Determine whether the interfaces in list Src are all present 154 -- in the list Dest. Return the first differing interface, or Empty 155 -- otherwise. 156 157 function Find_Type_Of_Subtype_Indic (S : Node_Id) return Entity_Id; 158 -- Given a subtype indication S (which is really an N_Subtype_Indication 159 -- node or a plain N_Identifier), find the type of the subtype mark. 160 161 function Find_Type_Name (N : Node_Id) return Entity_Id; 162 -- Enter the identifier in a type definition, or find the entity already 163 -- declared, in the case of the full declaration of an incomplete or 164 -- private type. If the previous declaration is tagged then the class-wide 165 -- entity is propagated to the identifier to prevent multiple incompatible 166 -- class-wide types that may be created for self-referential anonymous 167 -- access components. 168 169 function Get_Discriminant_Value 170 (Discriminant : Entity_Id; 171 Typ_For_Constraint : Entity_Id; 172 Constraint : Elist_Id) return Node_Id; 173 -- ??? MORE DOCUMENTATION 174 -- Given a discriminant somewhere in the Typ_For_Constraint tree and a 175 -- Constraint, return the value of that discriminant. 176 177 function Is_Null_Extension (T : Entity_Id) return Boolean; 178 -- Returns True if the tagged type T has an N_Full_Type_Declaration that 179 -- is a null extension, meaning that it has an extension part without any 180 -- components and does not have a known discriminant part. 181 182 function Is_Visible_Component 183 (C : Entity_Id; 184 N : Node_Id := Empty) return Boolean; 185 -- Determines if a record component C is visible in the present context. 186 -- Note that even though component C could appear in the entity chain 187 -- of a record type, C may not be visible in the current context. For 188 -- instance, C may be a component inherited in the full view of a private 189 -- extension which is not visible in the current context. 190 -- 191 -- If present, N is the selected component of which C is the selector. If 192 -- the prefix of N is a type conversion inserted for a discriminant check, 193 -- C is automatically visible. 194 195 procedure Make_Index 196 (I : Node_Id; 197 Related_Nod : Node_Id; 198 Related_Id : Entity_Id := Empty; 199 Suffix_Index : Nat := 1; 200 In_Iter_Schm : Boolean := False); 201 -- Process an index that is given in an array declaration, an entry 202 -- family declaration or a loop iteration. The index is given by an 203 -- index declaration (a 'box'), or by a discrete range. The later can 204 -- be the name of a discrete type, or a subtype indication. 205 -- 206 -- Related_Nod is the node where the potential generated implicit types 207 -- will be inserted. The next last parameters are used for creating the 208 -- name. In_Iter_Schm is True if Make_Index is called on the discrete 209 -- subtype definition in an iteration scheme. 210 211 procedure Make_Class_Wide_Type (T : Entity_Id); 212 -- A Class_Wide_Type is created for each tagged type definition. The 213 -- attributes of a class-wide type are inherited from those of the type T. 214 -- If T is introduced by a private declaration, the corresponding class 215 -- wide type is created at the same time, and therefore there is a private 216 -- and a full declaration for the class-wide type as well. 217 218 function OK_For_Limited_Init_In_05 219 (Typ : Entity_Id; 220 Exp : Node_Id) return Boolean; 221 -- Presuming Exp is an expression of an inherently limited type Typ, 222 -- returns True if the expression is allowed in an initialization context 223 -- by the rules of Ada 2005. We use the rule in RM-7.5(2.1/2), "...it is an 224 -- aggregate, a function_call, or a parenthesized expression or qualified 225 -- expression whose operand is permitted...". Note that in Ada 95 mode, 226 -- we sometimes wish to give warnings based on whether the program _would_ 227 -- be legal in Ada 2005. Note that Exp must already have been resolved, 228 -- so we can know whether it's a function call (as opposed to an indexed 229 -- component, for example). In the case where Typ is a limited interface's 230 -- class-wide type, then the expression is allowed to be of any kind if its 231 -- type is a nonlimited descendant of the interface. 232 233 function OK_For_Limited_Init 234 (Typ : Entity_Id; 235 Exp : Node_Id) return Boolean; 236 -- Always False in Ada 95 mode. Equivalent to OK_For_Limited_Init_In_05 in 237 -- Ada 2005 mode. 238 239 procedure Preanalyze_Spec_Expression (N : Node_Id; T : Entity_Id); 240 -- Default and per object expressions do not freeze their components, and 241 -- must be analyzed and resolved accordingly. The analysis is done by 242 -- calling the Preanalyze_And_Resolve routine and setting the global 243 -- In_Default_Expression flag. See the documentation section entitled 244 -- "Handling of Default and Per-Object Expressions" in sem.ads for full 245 -- details. N is the expression to be analyzed, T is the expected type. 246 -- This mechanism is also used for aspect specifications that have an 247 -- expression parameter that needs similar preanalysis. 248 249 procedure Preanalyze_Assert_Expression (N : Node_Id; T : Entity_Id); 250 -- Wrapper on Preanalyze_Spec_Expression for assertion expressions, so that 251 -- In_Assertion_Expr can be properly adjusted. 252 253 procedure Process_Full_View (N : Node_Id; Full_T, Priv_T : Entity_Id); 254 -- Process some semantic actions when the full view of a private type is 255 -- encountered and analyzed. The first action is to create the full views 256 -- of the dependant private subtypes. The second action is to recopy the 257 -- primitive operations of the private view (in the tagged case). 258 -- N is the N_Full_Type_Declaration node. 259 -- 260 -- Full_T is the full view of the type whose full declaration is in N. 261 -- 262 -- Priv_T is the private view of the type whose full declaration is in N. 263 264 procedure Process_Range_Expr_In_Decl 265 (R : Node_Id; 266 T : Entity_Id; 267 Check_List : List_Id := Empty_List; 268 R_Check_Off : Boolean := False; 269 In_Iter_Schm : Boolean := False); 270 -- Process a range expression that appears in a declaration context. The 271 -- range is analyzed and resolved with the base type of the given type, and 272 -- an appropriate check for expressions in non-static contexts made on the 273 -- bounds. R is analyzed and resolved using T, so the caller should if 274 -- necessary link R into the tree before the call, and in particular in the 275 -- case of a subtype declaration, it is appropriate to set the parent 276 -- pointer of R so that the types get properly frozen. Check_List is used 277 -- when the subprogram is called from Build_Record_Init_Proc and is used to 278 -- return a set of constraint checking statements generated by the Checks 279 -- package. R_Check_Off is set to True when the call to Range_Check is to 280 -- be skipped. In_Iter_Schm is True if Process_Range_Expr_In_Decl is called 281 -- on the discrete subtype definition in an iteration scheme. 282 283 function Process_Subtype 284 (S : Node_Id; 285 Related_Nod : Node_Id; 286 Related_Id : Entity_Id := Empty; 287 Suffix : Character := ' ') return Entity_Id; 288 -- Process a subtype indication S and return corresponding entity. 289 -- Related_Nod is the node where the potential generated implicit types 290 -- will be inserted. The Related_Id and Suffix parameters are used to 291 -- build the associated Implicit type name. 292 293 procedure Process_Discriminants 294 (N : Node_Id; 295 Prev : Entity_Id := Empty); 296 -- Process the discriminants contained in an N_Full_Type_Declaration or 297 -- N_Incomplete_Type_Decl node N. If the declaration is a completion, 298 -- Prev is entity on the partial view, on which references are posted. 299 -- However, note that Process_Discriminants is called for a completion only 300 -- if partial view had no discriminants (else we just check conformance 301 -- between the two views and do not call Process_Discriminants again for 302 -- the completion). 303 304 function Replace_Anonymous_Access_To_Protected_Subprogram 305 (N : Node_Id) return Entity_Id; 306 -- Ada 2005 (AI-254): Create and decorate an internal full type declaration 307 -- for an anonymous access to protected subprogram. For a record component 308 -- declaration, the type is created in the enclosing scope, for an array 309 -- type declaration or an object declaration it is simply placed ahead of 310 -- this declaration. 311 312 procedure Set_Completion_Referenced (E : Entity_Id); 313 -- If E is the completion of a private or incomplete type declaration, 314 -- or the completion of a deferred constant declaration, mark the entity 315 -- as referenced. Warnings on unused entities, if needed, go on the 316 -- partial view. 317 318end Sem_Ch3; 319