1------------------------------------------------------------------------------ 2-- -- 3-- GNAT COMPILER COMPONENTS -- 4-- -- 5-- S E M _ C H 6 -- 6-- -- 7-- S p e c -- 8-- -- 9-- Copyright (C) 1992-2021, 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; 27package Sem_Ch6 is 28 29 type Conformance_Type is 30 (Type_Conformant, Mode_Conformant, Subtype_Conformant, Fully_Conformant); 31 pragma Ordered (Conformance_Type); 32 -- Conformance type used in conformance checks between specs and bodies, 33 -- and for overriding. The literals match the RM definitions of the 34 -- corresponding terms. This is an ordered type, since each conformance 35 -- type is stronger than the ones preceding it. 36 37 procedure Analyze_Abstract_Subprogram_Declaration (N : Node_Id); 38 procedure Analyze_Expression_Function (N : Node_Id); 39 procedure Analyze_Extended_Return_Statement (N : Node_Id); 40 procedure Analyze_Function_Call (N : Node_Id); 41 procedure Analyze_Operator_Symbol (N : Node_Id); 42 procedure Analyze_Parameter_Association (N : Node_Id); 43 procedure Analyze_Procedure_Call (N : Node_Id); 44 procedure Analyze_Return_When_Statement (N : Node_Id); 45 procedure Analyze_Simple_Return_Statement (N : Node_Id); 46 procedure Analyze_Subprogram_Declaration (N : Node_Id); 47 procedure Analyze_Subprogram_Body (N : Node_Id); 48 49 function Analyze_Subprogram_Specification (N : Node_Id) return Entity_Id; 50 -- Analyze subprogram specification in both subprogram declarations 51 -- and body declarations. Returns the defining entity for the 52 -- specification N. 53 54 function Can_Override_Operator (Subp : Entity_Id) return Boolean; 55 -- Returns true if Subp can override a predefined operator 56 57 procedure Check_Conventions (Typ : Entity_Id); 58 -- Ada 2005 (AI-430): Check that the conventions of all inherited and 59 -- overridden dispatching operations of type Typ are consistent with their 60 -- respective counterparts. 61 62 procedure Check_Delayed_Subprogram (Designator : Entity_Id); 63 -- Designator can be a E_Subprogram_Type, E_Procedure or E_Function. If a 64 -- type in its profile depends on a private type without a full 65 -- declaration, indicate that the subprogram or type is delayed. 66 67 procedure Check_Discriminant_Conformance 68 (N : Node_Id; 69 Prev : Entity_Id; 70 Prev_Loc : Node_Id); 71 -- Check that the discriminants of a full type N fully conform to the 72 -- discriminants of the corresponding partial view Prev. Prev_Loc indicates 73 -- the source location of the partial view, which may be different than 74 -- Prev in the case of private types. 75 76 procedure Check_Formal_Subprogram_Conformance 77 (New_Id : Entity_Id; 78 Old_Id : Entity_Id; 79 Err_Loc : Node_Id := Empty); 80 -- Check RM 6.3.1(17/3): the profile of a generic formal subprogram is not 81 -- subtype conformant with any other profile and post an error message if 82 -- either New_Id or Old_Id denotes a formal subprogram, with the flag being 83 -- placed on the Err_Loc node if it is specified, and on New_Id if not. See 84 -- also spec of Check_Fully_Conformant below for New_Id and Old_Id usage. 85 86 procedure Check_Fully_Conformant 87 (New_Id : Entity_Id; 88 Old_Id : Entity_Id; 89 Err_Loc : Node_Id := Empty); 90 -- Check that two callable entities (subprograms, entries, literals) 91 -- are fully conformant, post error message if not (RM 6.3.1(17)) with 92 -- the flag being placed on the Err_Loc node if it is specified, and 93 -- on the appropriate component of the New_Id construct if not. Note: 94 -- when checking spec/body conformance, New_Id must be the body entity 95 -- and Old_Id is the spec entity (the code in the implementation relies 96 -- on this ordering, and in any case, this makes sense, since if flags 97 -- are to be placed on the construct, they clearly belong on the body. 98 99 procedure Check_Mode_Conformant 100 (New_Id : Entity_Id; 101 Old_Id : Entity_Id; 102 Err_Loc : Node_Id := Empty; 103 Get_Inst : Boolean := False); 104 -- Check that two callable entities (subprograms, entries, literals) 105 -- are mode conformant, post error message if not (RM 6.3.1(15)) with 106 -- the flag being placed on the Err_Loc node if it is specified, and 107 -- on the appropriate component of the New_Id construct if not. The 108 -- argument Get_Inst is set to True when this is a check against a 109 -- formal access-to-subprogram type, indicating that mapping of types 110 -- is needed. 111 112 procedure Check_Overriding_Indicator 113 (Subp : Entity_Id; 114 Overridden_Subp : Entity_Id; 115 Is_Primitive : Boolean); 116 -- Verify the consistency of an overriding_indicator given for subprogram 117 -- declaration, body, renaming, or instantiation. Overridden_Subp is set 118 -- if the scope where we are introducing the subprogram contains a 119 -- type-conformant subprogram that becomes hidden by the new subprogram. 120 -- Is_Primitive indicates whether the subprogram is primitive. 121 122 procedure Check_Subtype_Conformant 123 (New_Id : Entity_Id; 124 Old_Id : Entity_Id; 125 Err_Loc : Node_Id := Empty; 126 Skip_Controlling_Formals : Boolean := False; 127 Get_Inst : Boolean := False); 128 -- Check that two callable entities (subprograms, entries, literals) 129 -- are subtype conformant, post error message if not (RM 6.3.1(16)), 130 -- the flag being placed on the Err_Loc node if it is specified, and 131 -- on the appropriate component of the New_Id construct if not. 132 -- Skip_Controlling_Formals is True when checking the conformance of 133 -- a subprogram that implements an interface operation. In that case, 134 -- only the non-controlling formals can (and must) be examined. The 135 -- argument Get_Inst is set to True when this is a check against a 136 -- formal access-to-subprogram type, indicating that mapping of types 137 -- is needed. 138 139 procedure Check_Synchronized_Overriding 140 (Def_Id : Entity_Id; 141 Overridden_Subp : out Entity_Id); 142 -- First determine if Def_Id is an entry or a subprogram either defined in 143 -- the scope of a task or protected type, or that is a primitive of such 144 -- a type. Check whether Def_Id overrides a subprogram of an interface 145 -- implemented by the synchronized type, returning the overridden entity 146 -- or Empty. 147 148 procedure Check_Type_Conformant 149 (New_Id : Entity_Id; 150 Old_Id : Entity_Id; 151 Err_Loc : Node_Id := Empty); 152 -- Check that two callable entities (subprograms, entries, literals) 153 -- are type conformant, post error message if not (RM 6.3.1(14)) with 154 -- the flag being placed on the Err_Loc node if it is specified, and 155 -- on the appropriate component of the New_Id construct if not. 156 157 function Conforming_Types 158 (T1 : Entity_Id; 159 T2 : Entity_Id; 160 Ctype : Conformance_Type; 161 Get_Inst : Boolean := False) return Boolean; 162 -- Check that the types of two formal parameters are conforming. In most 163 -- cases this is just a name comparison, but within an instance it involves 164 -- generic actual types, and in the presence of anonymous access types 165 -- it must examine the designated types. The argument Get_Inst is set to 166 -- True when this is a check against a formal access-to-subprogram type, 167 -- indicating that mapping of types is needed. 168 169 procedure Create_Extra_Formals (E : Entity_Id); 170 -- For each parameter of a subprogram or entry that requires an additional 171 -- formal (such as for access parameters and indefinite discriminated 172 -- parameters), creates the appropriate formal and attach it to its 173 -- associated parameter. Each extra formal will also be appended to 174 -- the end of Subp's parameter list (with each subsequent extra formal 175 -- being attached to the preceding extra formal). 176 177 function Find_Corresponding_Spec 178 (N : Node_Id; 179 Post_Error : Boolean := True) return Entity_Id; 180 -- Use the subprogram specification in the body to retrieve the previous 181 -- subprogram declaration, if any. 182 183 function Fully_Conformant (New_Id, Old_Id : Entity_Id) return Boolean; 184 -- Determine whether two callable entities (subprograms, entries, 185 -- literals) are fully conformant (RM 6.3.1(17)) 186 187 function Fully_Conformant_Expressions 188 (Given_E1 : Node_Id; 189 Given_E2 : Node_Id; 190 Report : Boolean := False) return Boolean; 191 -- Determines if two (non-empty) expressions are fully conformant 192 -- as defined by (RM 6.3.1(18-21)) 193 194 function Fully_Conformant_Discrete_Subtypes 195 (Given_S1 : Node_Id; 196 Given_S2 : Node_Id) return Boolean; 197 -- Determines if two subtype definitions are fully conformant. Used 198 -- for entry family conformance checks (RM 6.3.1 (24)). 199 200 procedure Install_Entity (E : Entity_Id); 201 -- Place a single entity on the visibility chain 202 203 procedure Install_Formals (Id : Entity_Id); 204 -- On entry to a subprogram body, make the formals visible. Note that 205 -- simply placing the subprogram on the scope stack is not sufficient: 206 -- the formals must become the current entities for their names. This 207 -- procedure is also used to get visibility to the formals when analyzing 208 -- preconditions and postconditions appearing in the spec. 209 210 function Is_Interface_Conformant 211 (Tagged_Type : Entity_Id; 212 Iface_Prim : Entity_Id; 213 Prim : Entity_Id) return Boolean; 214 -- Returns true if both primitives have a matching name (including support 215 -- for names of inherited private primitives --which have suffix 'P'), they 216 -- are type conformant, and Prim is defined in the scope of Tagged_Type. 217 -- Special management is done for functions returning interfaces. 218 219 procedure List_Inherited_Pre_Post_Aspects (E : Entity_Id); 220 -- E is the entity for a subprogram or generic subprogram spec. This call 221 -- lists all inherited Pre/Post aspects if List_Inherited_Pre_Post is True. 222 223 procedure May_Need_Actuals (Fun : Entity_Id); 224 -- Flag functions that can be called without parameters, i.e. those that 225 -- have no parameters, or those for which defaults exist for all parameters 226 -- Used for subprogram declarations and for access subprogram declarations, 227 -- where they apply to the anonymous designated type. On return the flag 228 -- Set_Needs_No_Actuals is set appropriately in Fun. 229 230 function Mode_Conformant (New_Id, Old_Id : Entity_Id) return Boolean; 231 -- Determine whether two callable entities (subprograms, entries, 232 -- literals) are mode conformant (RM 6.3.1(15)) 233 234 procedure New_Overloaded_Entity 235 (S : Entity_Id; 236 Derived_Type : Entity_Id := Empty); 237 -- Process new overloaded entity. Overloaded entities are created by 238 -- enumeration type declarations, subprogram specifications, entry 239 -- declarations, and (implicitly) by type derivations. If Derived_Type 240 -- is non-empty then this is a subprogram derived for that type. 241 242 procedure Process_Formals (T : List_Id; Related_Nod : Node_Id); 243 -- Enter the formals in the scope of the subprogram or entry, and 244 -- analyze default expressions if any. The implicit types created for 245 -- access parameter are attached to the Related_Nod which comes from the 246 -- context. 247 248 procedure Reference_Body_Formals (Spec : Entity_Id; Bod : Entity_Id); 249 -- If there is a separate spec for a subprogram or generic subprogram, the 250 -- formals of the body are treated as references to the corresponding 251 -- formals of the spec. This reference does not count as an actual use of 252 -- the formal, in order to diagnose formals that are unused in the body. 253 -- This procedure is also used in renaming_as_body declarations, where 254 -- the formals of the specification must be treated as body formals that 255 -- correspond to the previous subprogram declaration, and not as new 256 -- entities with their defining entry in the cross-reference information. 257 258 procedure Set_Actual_Subtypes (N : Node_Id; Subp : Entity_Id); 259 -- If the formals of a subprogram are unconstrained, build a subtype 260 -- declaration that uses the bounds or discriminants of the actual to 261 -- construct an actual subtype for them. This is an optimization that 262 -- is done only in some cases where the actual subtype cannot change 263 -- during execution of the subprogram. By setting the actual subtype 264 -- once, we avoid recomputing it unnecessarily. 265 266 procedure Set_Formal_Mode (Formal_Id : Entity_Id); 267 -- Set proper Ekind to reflect formal mode (in, out, in out) 268 269 function Subtype_Conformant 270 (New_Id : Entity_Id; 271 Old_Id : Entity_Id; 272 Skip_Controlling_Formals : Boolean := False) return Boolean; 273 -- Determine whether two callable entities (subprograms, entries, literals) 274 -- are subtype conformant (RM 6.3.1(16)). Skip_Controlling_Formals is True 275 -- when checking the conformance of a subprogram that implements an 276 -- interface operation. In that case, only the non-controlling formals 277 -- can (and must) be examined. 278 279 function Type_Conformant 280 (New_Id : Entity_Id; 281 Old_Id : Entity_Id; 282 Skip_Controlling_Formals : Boolean := False) return Boolean; 283 -- Determine whether two callable entities (subprograms, entries, literals) 284 -- are type conformant (RM 6.3.1(14)). Skip_Controlling_Formals is True 285 -- when checking the conformance of a subprogram that implements an 286 -- interface operation. In that case, only the non-controlling formals 287 -- can (and must) be examined. 288 289 procedure Valid_Operator_Definition (Designator : Entity_Id); 290 -- Verify that an operator definition has the proper number of formals 291 292end Sem_Ch6; 293