1------------------------------------------------------------------------------ 2-- -- 3-- GNAT COMPILER COMPONENTS -- 4-- -- 5-- S E M _ A G G R -- 6-- -- 7-- B o d y -- 8-- -- 9-- Copyright (C) 1992-2019, 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 Aspects; use Aspects; 27with Atree; use Atree; 28with Checks; use Checks; 29with Einfo; use Einfo; 30with Elists; use Elists; 31with Errout; use Errout; 32with Expander; use Expander; 33with Exp_Ch6; use Exp_Ch6; 34with Exp_Tss; use Exp_Tss; 35with Exp_Util; use Exp_Util; 36with Freeze; use Freeze; 37with Itypes; use Itypes; 38with Lib; use Lib; 39with Lib.Xref; use Lib.Xref; 40with Namet; use Namet; 41with Namet.Sp; use Namet.Sp; 42with Nmake; use Nmake; 43with Nlists; use Nlists; 44with Opt; use Opt; 45with Restrict; use Restrict; 46with Rident; use Rident; 47with Sem; use Sem; 48with Sem_Aux; use Sem_Aux; 49with Sem_Cat; use Sem_Cat; 50with Sem_Ch3; use Sem_Ch3; 51with Sem_Ch8; use Sem_Ch8; 52with Sem_Ch13; use Sem_Ch13; 53with Sem_Dim; use Sem_Dim; 54with Sem_Eval; use Sem_Eval; 55with Sem_Res; use Sem_Res; 56with Sem_Util; use Sem_Util; 57with Sem_Type; use Sem_Type; 58with Sem_Warn; use Sem_Warn; 59with Sinfo; use Sinfo; 60with Snames; use Snames; 61with Stringt; use Stringt; 62with Stand; use Stand; 63with Style; use Style; 64with Targparm; use Targparm; 65with Tbuild; use Tbuild; 66with Uintp; use Uintp; 67 68package body Sem_Aggr is 69 70 type Case_Bounds is record 71 Lo : Node_Id; 72 -- Low bound of choice. Once we sort the Case_Table, then entries 73 -- will be in order of ascending Choice_Lo values. 74 75 Hi : Node_Id; 76 -- High Bound of choice. The sort does not pay any attention to the 77 -- high bound, so choices 1 .. 4 and 1 .. 5 could be in either order. 78 79 Highest : Uint; 80 -- If there are duplicates or missing entries, then in the sorted 81 -- table, this records the highest value among Choice_Hi values 82 -- seen so far, including this entry. 83 84 Choice : Node_Id; 85 -- The node of the choice 86 end record; 87 88 type Case_Table_Type is array (Nat range <>) of Case_Bounds; 89 -- Table type used by Check_Case_Choices procedure. Entry zero is not 90 -- used (reserved for the sort). Real entries start at one. 91 92 ----------------------- 93 -- Local Subprograms -- 94 ----------------------- 95 96 procedure Sort_Case_Table (Case_Table : in out Case_Table_Type); 97 -- Sort the Case Table using the Lower Bound of each Choice as the key. A 98 -- simple insertion sort is used since the choices in a case statement will 99 -- usually be in near sorted order. 100 101 procedure Check_Can_Never_Be_Null (Typ : Entity_Id; Expr : Node_Id); 102 -- Ada 2005 (AI-231): Check bad usage of null for a component for which 103 -- null exclusion (NOT NULL) is specified. Typ can be an E_Array_Type for 104 -- the array case (the component type of the array will be used) or an 105 -- E_Component/E_Discriminant entity in the record case, in which case the 106 -- type of the component will be used for the test. If Typ is any other 107 -- kind of entity, the call is ignored. Expr is the component node in the 108 -- aggregate which is known to have a null value. A warning message will be 109 -- issued if the component is null excluding. 110 -- 111 -- It would be better to pass the proper type for Typ ??? 112 113 procedure Check_Expr_OK_In_Limited_Aggregate (Expr : Node_Id); 114 -- Check that Expr is either not limited or else is one of the cases of 115 -- expressions allowed for a limited component association (namely, an 116 -- aggregate, function call, or <> notation). Report error for violations. 117 -- Expression is also OK in an instance or inlining context, because we 118 -- have already preanalyzed and it is known to be type correct. 119 120 procedure Check_Qualified_Aggregate (Level : Nat; Expr : Node_Id); 121 -- Given aggregate Expr, check that sub-aggregates of Expr that are nested 122 -- at Level are qualified. If Level = 0, this applies to Expr directly. 123 -- Only issue errors in formal verification mode. 124 125 function Is_Top_Level_Aggregate (Expr : Node_Id) return Boolean; 126 -- Return True of Expr is an aggregate not contained directly in another 127 -- aggregate. 128 129 ------------------------------------------------------ 130 -- Subprograms used for RECORD AGGREGATE Processing -- 131 ------------------------------------------------------ 132 133 procedure Resolve_Record_Aggregate (N : Node_Id; Typ : Entity_Id); 134 -- This procedure performs all the semantic checks required for record 135 -- aggregates. Note that for aggregates analysis and resolution go 136 -- hand in hand. Aggregate analysis has been delayed up to here and 137 -- it is done while resolving the aggregate. 138 -- 139 -- N is the N_Aggregate node. 140 -- Typ is the record type for the aggregate resolution 141 -- 142 -- While performing the semantic checks, this procedure builds a new 143 -- Component_Association_List where each record field appears alone in a 144 -- Component_Choice_List along with its corresponding expression. The 145 -- record fields in the Component_Association_List appear in the same order 146 -- in which they appear in the record type Typ. 147 -- 148 -- Once this new Component_Association_List is built and all the semantic 149 -- checks performed, the original aggregate subtree is replaced with the 150 -- new named record aggregate just built. Note that subtree substitution is 151 -- performed with Rewrite so as to be able to retrieve the original 152 -- aggregate. 153 -- 154 -- The aggregate subtree manipulation performed by Resolve_Record_Aggregate 155 -- yields the aggregate format expected by Gigi. Typically, this kind of 156 -- tree manipulations are done in the expander. However, because the 157 -- semantic checks that need to be performed on record aggregates really go 158 -- hand in hand with the record aggregate normalization, the aggregate 159 -- subtree transformation is performed during resolution rather than 160 -- expansion. Had we decided otherwise we would have had to duplicate most 161 -- of the code in the expansion procedure Expand_Record_Aggregate. Note, 162 -- however, that all the expansion concerning aggregates for tagged records 163 -- is done in Expand_Record_Aggregate. 164 -- 165 -- The algorithm of Resolve_Record_Aggregate proceeds as follows: 166 -- 167 -- 1. Make sure that the record type against which the record aggregate 168 -- has to be resolved is not abstract. Furthermore if the type is a 169 -- null aggregate make sure the input aggregate N is also null. 170 -- 171 -- 2. Verify that the structure of the aggregate is that of a record 172 -- aggregate. Specifically, look for component associations and ensure 173 -- that each choice list only has identifiers or the N_Others_Choice 174 -- node. Also make sure that if present, the N_Others_Choice occurs 175 -- last and by itself. 176 -- 177 -- 3. If Typ contains discriminants, the values for each discriminant is 178 -- looked for. If the record type Typ has variants, we check that the 179 -- expressions corresponding to each discriminant ruling the (possibly 180 -- nested) variant parts of Typ, are static. This allows us to determine 181 -- the variant parts to which the rest of the aggregate must conform. 182 -- The names of discriminants with their values are saved in a new 183 -- association list, New_Assoc_List which is later augmented with the 184 -- names and values of the remaining components in the record type. 185 -- 186 -- During this phase we also make sure that every discriminant is 187 -- assigned exactly one value. Note that when several values for a given 188 -- discriminant are found, semantic processing continues looking for 189 -- further errors. In this case it's the first discriminant value found 190 -- which we will be recorded. 191 -- 192 -- IMPORTANT NOTE: For derived tagged types this procedure expects 193 -- First_Discriminant and Next_Discriminant to give the correct list 194 -- of discriminants, in the correct order. 195 -- 196 -- 4. After all the discriminant values have been gathered, we can set the 197 -- Etype of the record aggregate. If Typ contains no discriminants this 198 -- is straightforward: the Etype of N is just Typ, otherwise a new 199 -- implicit constrained subtype of Typ is built to be the Etype of N. 200 -- 201 -- 5. Gather the remaining record components according to the discriminant 202 -- values. This involves recursively traversing the record type 203 -- structure to see what variants are selected by the given discriminant 204 -- values. This processing is a little more convoluted if Typ is a 205 -- derived tagged types since we need to retrieve the record structure 206 -- of all the ancestors of Typ. 207 -- 208 -- 6. After gathering the record components we look for their values in the 209 -- record aggregate and emit appropriate error messages should we not 210 -- find such values or should they be duplicated. 211 -- 212 -- 7. We then make sure no illegal component names appear in the record 213 -- aggregate and make sure that the type of the record components 214 -- appearing in a same choice list is the same. Finally we ensure that 215 -- the others choice, if present, is used to provide the value of at 216 -- least a record component. 217 -- 218 -- 8. The original aggregate node is replaced with the new named aggregate 219 -- built in steps 3 through 6, as explained earlier. 220 -- 221 -- Given the complexity of record aggregate resolution, the primary goal of 222 -- this routine is clarity and simplicity rather than execution and storage 223 -- efficiency. If there are only positional components in the aggregate the 224 -- running time is linear. If there are associations the running time is 225 -- still linear as long as the order of the associations is not too far off 226 -- the order of the components in the record type. If this is not the case 227 -- the running time is at worst quadratic in the size of the association 228 -- list. 229 230 procedure Check_Misspelled_Component 231 (Elements : Elist_Id; 232 Component : Node_Id); 233 -- Give possible misspelling diagnostic if Component is likely to be a 234 -- misspelling of one of the components of the Assoc_List. This is called 235 -- by Resolve_Aggr_Expr after producing an invalid component error message. 236 237 procedure Check_Static_Discriminated_Subtype (T : Entity_Id; V : Node_Id); 238 -- An optimization: determine whether a discriminated subtype has a static 239 -- constraint, and contains array components whose length is also static, 240 -- either because they are constrained by the discriminant, or because the 241 -- original component bounds are static. 242 243 ----------------------------------------------------- 244 -- Subprograms used for ARRAY AGGREGATE Processing -- 245 ----------------------------------------------------- 246 247 function Resolve_Array_Aggregate 248 (N : Node_Id; 249 Index : Node_Id; 250 Index_Constr : Node_Id; 251 Component_Typ : Entity_Id; 252 Others_Allowed : Boolean) return Boolean; 253 -- This procedure performs the semantic checks for an array aggregate. 254 -- True is returned if the aggregate resolution succeeds. 255 -- 256 -- The procedure works by recursively checking each nested aggregate. 257 -- Specifically, after checking a sub-aggregate nested at the i-th level 258 -- we recursively check all the subaggregates at the i+1-st level (if any). 259 -- Note that for aggregates analysis and resolution go hand in hand. 260 -- Aggregate analysis has been delayed up to here and it is done while 261 -- resolving the aggregate. 262 -- 263 -- N is the current N_Aggregate node to be checked. 264 -- 265 -- Index is the index node corresponding to the array sub-aggregate that 266 -- we are currently checking (RM 4.3.3 (8)). Its Etype is the 267 -- corresponding index type (or subtype). 268 -- 269 -- Index_Constr is the node giving the applicable index constraint if 270 -- any (RM 4.3.3 (10)). It "is a constraint provided by certain 271 -- contexts [...] that can be used to determine the bounds of the array 272 -- value specified by the aggregate". If Others_Allowed below is False 273 -- there is no applicable index constraint and this node is set to Index. 274 -- 275 -- Component_Typ is the array component type. 276 -- 277 -- Others_Allowed indicates whether an others choice is allowed 278 -- in the context where the top-level aggregate appeared. 279 -- 280 -- The algorithm of Resolve_Array_Aggregate proceeds as follows: 281 -- 282 -- 1. Make sure that the others choice, if present, is by itself and 283 -- appears last in the sub-aggregate. Check that we do not have 284 -- positional and named components in the array sub-aggregate (unless 285 -- the named association is an others choice). Finally if an others 286 -- choice is present, make sure it is allowed in the aggregate context. 287 -- 288 -- 2. If the array sub-aggregate contains discrete_choices: 289 -- 290 -- (A) Verify their validity. Specifically verify that: 291 -- 292 -- (a) If a null range is present it must be the only possible 293 -- choice in the array aggregate. 294 -- 295 -- (b) Ditto for a non static range. 296 -- 297 -- (c) Ditto for a non static expression. 298 -- 299 -- In addition this step analyzes and resolves each discrete_choice, 300 -- making sure that its type is the type of the corresponding Index. 301 -- If we are not at the lowest array aggregate level (in the case of 302 -- multi-dimensional aggregates) then invoke Resolve_Array_Aggregate 303 -- recursively on each component expression. Otherwise, resolve the 304 -- bottom level component expressions against the expected component 305 -- type ONLY IF the component corresponds to a single discrete choice 306 -- which is not an others choice (to see why read the DELAYED 307 -- COMPONENT RESOLUTION below). 308 -- 309 -- (B) Determine the bounds of the sub-aggregate and lowest and 310 -- highest choice values. 311 -- 312 -- 3. For positional aggregates: 313 -- 314 -- (A) Loop over the component expressions either recursively invoking 315 -- Resolve_Array_Aggregate on each of these for multi-dimensional 316 -- array aggregates or resolving the bottom level component 317 -- expressions against the expected component type. 318 -- 319 -- (B) Determine the bounds of the positional sub-aggregates. 320 -- 321 -- 4. Try to determine statically whether the evaluation of the array 322 -- sub-aggregate raises Constraint_Error. If yes emit proper 323 -- warnings. The precise checks are the following: 324 -- 325 -- (A) Check that the index range defined by aggregate bounds is 326 -- compatible with corresponding index subtype. 327 -- We also check against the base type. In fact it could be that 328 -- Low/High bounds of the base type are static whereas those of 329 -- the index subtype are not. Thus if we can statically catch 330 -- a problem with respect to the base type we are guaranteed 331 -- that the same problem will arise with the index subtype 332 -- 333 -- (B) If we are dealing with a named aggregate containing an others 334 -- choice and at least one discrete choice then make sure the range 335 -- specified by the discrete choices does not overflow the 336 -- aggregate bounds. We also check against the index type and base 337 -- type bounds for the same reasons given in (A). 338 -- 339 -- (C) If we are dealing with a positional aggregate with an others 340 -- choice make sure the number of positional elements specified 341 -- does not overflow the aggregate bounds. We also check against 342 -- the index type and base type bounds as mentioned in (A). 343 -- 344 -- Finally construct an N_Range node giving the sub-aggregate bounds. 345 -- Set the Aggregate_Bounds field of the sub-aggregate to be this 346 -- N_Range. The routine Array_Aggr_Subtype below uses such N_Ranges 347 -- to build the appropriate aggregate subtype. Aggregate_Bounds 348 -- information is needed during expansion. 349 -- 350 -- DELAYED COMPONENT RESOLUTION: The resolution of bottom level component 351 -- expressions in an array aggregate may call Duplicate_Subexpr or some 352 -- other routine that inserts code just outside the outermost aggregate. 353 -- If the array aggregate contains discrete choices or an others choice, 354 -- this may be wrong. Consider for instance the following example. 355 -- 356 -- type Rec is record 357 -- V : Integer := 0; 358 -- end record; 359 -- 360 -- type Acc_Rec is access Rec; 361 -- Arr : array (1..3) of Acc_Rec := (1 .. 3 => new Rec); 362 -- 363 -- Then the transformation of "new Rec" that occurs during resolution 364 -- entails the following code modifications 365 -- 366 -- P7b : constant Acc_Rec := new Rec; 367 -- RecIP (P7b.all); 368 -- Arr : array (1..3) of Acc_Rec := (1 .. 3 => P7b); 369 -- 370 -- This code transformation is clearly wrong, since we need to call 371 -- "new Rec" for each of the 3 array elements. To avoid this problem we 372 -- delay resolution of the components of non positional array aggregates 373 -- to the expansion phase. As an optimization, if the discrete choice 374 -- specifies a single value we do not delay resolution. 375 376 function Array_Aggr_Subtype (N : Node_Id; Typ : Node_Id) return Entity_Id; 377 -- This routine returns the type or subtype of an array aggregate. 378 -- 379 -- N is the array aggregate node whose type we return. 380 -- 381 -- Typ is the context type in which N occurs. 382 -- 383 -- This routine creates an implicit array subtype whose bounds are 384 -- those defined by the aggregate. When this routine is invoked 385 -- Resolve_Array_Aggregate has already processed aggregate N. Thus the 386 -- Aggregate_Bounds of each sub-aggregate, is an N_Range node giving the 387 -- sub-aggregate bounds. When building the aggregate itype, this function 388 -- traverses the array aggregate N collecting such Aggregate_Bounds and 389 -- constructs the proper array aggregate itype. 390 -- 391 -- Note that in the case of multidimensional aggregates each inner 392 -- sub-aggregate corresponding to a given array dimension, may provide a 393 -- different bounds. If it is possible to determine statically that 394 -- some sub-aggregates corresponding to the same index do not have the 395 -- same bounds, then a warning is emitted. If such check is not possible 396 -- statically (because some sub-aggregate bounds are dynamic expressions) 397 -- then this job is left to the expander. In all cases the particular 398 -- bounds that this function will chose for a given dimension is the first 399 -- N_Range node for a sub-aggregate corresponding to that dimension. 400 -- 401 -- Note that the Raises_Constraint_Error flag of an array aggregate 402 -- whose evaluation is determined to raise CE by Resolve_Array_Aggregate, 403 -- is set in Resolve_Array_Aggregate but the aggregate is not 404 -- immediately replaced with a raise CE. In fact, Array_Aggr_Subtype must 405 -- first construct the proper itype for the aggregate (Gigi needs 406 -- this). After constructing the proper itype we will eventually replace 407 -- the top-level aggregate with a raise CE (done in Resolve_Aggregate). 408 -- Of course in cases such as: 409 -- 410 -- type Arr is array (integer range <>) of Integer; 411 -- A : Arr := (positive range -1 .. 2 => 0); 412 -- 413 -- The bounds of the aggregate itype are cooked up to look reasonable 414 -- (in this particular case the bounds will be 1 .. 2). 415 416 procedure Make_String_Into_Aggregate (N : Node_Id); 417 -- A string literal can appear in a context in which a one dimensional 418 -- array of characters is expected. This procedure simply rewrites the 419 -- string as an aggregate, prior to resolution. 420 421 --------------------------------- 422 -- Delta aggregate processing -- 423 --------------------------------- 424 425 procedure Resolve_Delta_Array_Aggregate (N : Node_Id; Typ : Entity_Id); 426 procedure Resolve_Delta_Record_Aggregate (N : Node_Id; Typ : Entity_Id); 427 428 ------------------------ 429 -- Array_Aggr_Subtype -- 430 ------------------------ 431 432 function Array_Aggr_Subtype 433 (N : Node_Id; 434 Typ : Entity_Id) return Entity_Id 435 is 436 Aggr_Dimension : constant Pos := Number_Dimensions (Typ); 437 -- Number of aggregate index dimensions 438 439 Aggr_Range : array (1 .. Aggr_Dimension) of Node_Id := (others => Empty); 440 -- Constrained N_Range of each index dimension in our aggregate itype 441 442 Aggr_Low : array (1 .. Aggr_Dimension) of Node_Id := (others => Empty); 443 Aggr_High : array (1 .. Aggr_Dimension) of Node_Id := (others => Empty); 444 -- Low and High bounds for each index dimension in our aggregate itype 445 446 Is_Fully_Positional : Boolean := True; 447 448 procedure Collect_Aggr_Bounds (N : Node_Id; Dim : Pos); 449 -- N is an array (sub-)aggregate. Dim is the dimension corresponding 450 -- to (sub-)aggregate N. This procedure collects and removes the side 451 -- effects of the constrained N_Range nodes corresponding to each index 452 -- dimension of our aggregate itype. These N_Range nodes are collected 453 -- in Aggr_Range above. 454 -- 455 -- Likewise collect in Aggr_Low & Aggr_High above the low and high 456 -- bounds of each index dimension. If, when collecting, two bounds 457 -- corresponding to the same dimension are static and found to differ, 458 -- then emit a warning, and mark N as raising Constraint_Error. 459 460 ------------------------- 461 -- Collect_Aggr_Bounds -- 462 ------------------------- 463 464 procedure Collect_Aggr_Bounds (N : Node_Id; Dim : Pos) is 465 This_Range : constant Node_Id := Aggregate_Bounds (N); 466 -- The aggregate range node of this specific sub-aggregate 467 468 This_Low : constant Node_Id := Low_Bound (Aggregate_Bounds (N)); 469 This_High : constant Node_Id := High_Bound (Aggregate_Bounds (N)); 470 -- The aggregate bounds of this specific sub-aggregate 471 472 Assoc : Node_Id; 473 Expr : Node_Id; 474 475 begin 476 Remove_Side_Effects (This_Low, Variable_Ref => True); 477 Remove_Side_Effects (This_High, Variable_Ref => True); 478 479 -- Collect the first N_Range for a given dimension that you find. 480 -- For a given dimension they must be all equal anyway. 481 482 if No (Aggr_Range (Dim)) then 483 Aggr_Low (Dim) := This_Low; 484 Aggr_High (Dim) := This_High; 485 Aggr_Range (Dim) := This_Range; 486 487 else 488 if Compile_Time_Known_Value (This_Low) then 489 if not Compile_Time_Known_Value (Aggr_Low (Dim)) then 490 Aggr_Low (Dim) := This_Low; 491 492 elsif Expr_Value (This_Low) /= Expr_Value (Aggr_Low (Dim)) then 493 Set_Raises_Constraint_Error (N); 494 Error_Msg_Warn := SPARK_Mode /= On; 495 Error_Msg_N ("sub-aggregate low bound mismatch<<", N); 496 Error_Msg_N ("\Constraint_Error [<<", N); 497 end if; 498 end if; 499 500 if Compile_Time_Known_Value (This_High) then 501 if not Compile_Time_Known_Value (Aggr_High (Dim)) then 502 Aggr_High (Dim) := This_High; 503 504 elsif 505 Expr_Value (This_High) /= Expr_Value (Aggr_High (Dim)) 506 then 507 Set_Raises_Constraint_Error (N); 508 Error_Msg_Warn := SPARK_Mode /= On; 509 Error_Msg_N ("sub-aggregate high bound mismatch<<", N); 510 Error_Msg_N ("\Constraint_Error [<<", N); 511 end if; 512 end if; 513 end if; 514 515 if Dim < Aggr_Dimension then 516 517 -- Process positional components 518 519 if Present (Expressions (N)) then 520 Expr := First (Expressions (N)); 521 while Present (Expr) loop 522 Collect_Aggr_Bounds (Expr, Dim + 1); 523 Next (Expr); 524 end loop; 525 end if; 526 527 -- Process component associations 528 529 if Present (Component_Associations (N)) then 530 Is_Fully_Positional := False; 531 532 Assoc := First (Component_Associations (N)); 533 while Present (Assoc) loop 534 Expr := Expression (Assoc); 535 Collect_Aggr_Bounds (Expr, Dim + 1); 536 Next (Assoc); 537 end loop; 538 end if; 539 end if; 540 end Collect_Aggr_Bounds; 541 542 -- Array_Aggr_Subtype variables 543 544 Itype : Entity_Id; 545 -- The final itype of the overall aggregate 546 547 Index_Constraints : constant List_Id := New_List; 548 -- The list of index constraints of the aggregate itype 549 550 -- Start of processing for Array_Aggr_Subtype 551 552 begin 553 -- Make sure that the list of index constraints is properly attached to 554 -- the tree, and then collect the aggregate bounds. 555 556 Set_Parent (Index_Constraints, N); 557 Collect_Aggr_Bounds (N, 1); 558 559 -- Build the list of constrained indexes of our aggregate itype 560 561 for J in 1 .. Aggr_Dimension loop 562 Create_Index : declare 563 Index_Base : constant Entity_Id := 564 Base_Type (Etype (Aggr_Range (J))); 565 Index_Typ : Entity_Id; 566 567 begin 568 -- Construct the Index subtype, and associate it with the range 569 -- construct that generates it. 570 571 Index_Typ := 572 Create_Itype (Subtype_Kind (Ekind (Index_Base)), Aggr_Range (J)); 573 574 Set_Etype (Index_Typ, Index_Base); 575 576 if Is_Character_Type (Index_Base) then 577 Set_Is_Character_Type (Index_Typ); 578 end if; 579 580 Set_Size_Info (Index_Typ, (Index_Base)); 581 Set_RM_Size (Index_Typ, RM_Size (Index_Base)); 582 Set_First_Rep_Item (Index_Typ, First_Rep_Item (Index_Base)); 583 Set_Scalar_Range (Index_Typ, Aggr_Range (J)); 584 585 if Is_Discrete_Or_Fixed_Point_Type (Index_Typ) then 586 Set_RM_Size (Index_Typ, UI_From_Int (Minimum_Size (Index_Typ))); 587 end if; 588 589 Set_Etype (Aggr_Range (J), Index_Typ); 590 591 Append (Aggr_Range (J), To => Index_Constraints); 592 end Create_Index; 593 end loop; 594 595 -- Now build the Itype 596 597 Itype := Create_Itype (E_Array_Subtype, N); 598 599 Set_First_Rep_Item (Itype, First_Rep_Item (Typ)); 600 Set_Convention (Itype, Convention (Typ)); 601 Set_Depends_On_Private (Itype, Has_Private_Component (Typ)); 602 Set_Etype (Itype, Base_Type (Typ)); 603 Set_Has_Alignment_Clause (Itype, Has_Alignment_Clause (Typ)); 604 Set_Is_Aliased (Itype, Is_Aliased (Typ)); 605 Set_Depends_On_Private (Itype, Depends_On_Private (Typ)); 606 607 Copy_Suppress_Status (Index_Check, Typ, Itype); 608 Copy_Suppress_Status (Length_Check, Typ, Itype); 609 610 Set_First_Index (Itype, First (Index_Constraints)); 611 Set_Is_Constrained (Itype, True); 612 Set_Is_Internal (Itype, True); 613 614 if Has_Predicates (Typ) then 615 Set_Has_Predicates (Itype); 616 617 if Present (Predicate_Function (Typ)) then 618 Set_Predicate_Function (Itype, Predicate_Function (Typ)); 619 else 620 Set_Predicated_Parent (Itype, Predicated_Parent (Typ)); 621 end if; 622 end if; 623 624 -- A simple optimization: purely positional aggregates of static 625 -- components should be passed to gigi unexpanded whenever possible, and 626 -- regardless of the staticness of the bounds themselves. Subsequent 627 -- checks in exp_aggr verify that type is not packed, etc. 628 629 Set_Size_Known_At_Compile_Time 630 (Itype, 631 Is_Fully_Positional 632 and then Comes_From_Source (N) 633 and then Size_Known_At_Compile_Time (Component_Type (Typ))); 634 635 -- We always need a freeze node for a packed array subtype, so that we 636 -- can build the Packed_Array_Impl_Type corresponding to the subtype. If 637 -- expansion is disabled, the packed array subtype is not built, and we 638 -- must not generate a freeze node for the type, or else it will appear 639 -- incomplete to gigi. 640 641 if Is_Packed (Itype) 642 and then not In_Spec_Expression 643 and then Expander_Active 644 then 645 Freeze_Itype (Itype, N); 646 end if; 647 648 return Itype; 649 end Array_Aggr_Subtype; 650 651 -------------------------------- 652 -- Check_Misspelled_Component -- 653 -------------------------------- 654 655 procedure Check_Misspelled_Component 656 (Elements : Elist_Id; 657 Component : Node_Id) 658 is 659 Max_Suggestions : constant := 2; 660 661 Nr_Of_Suggestions : Natural := 0; 662 Suggestion_1 : Entity_Id := Empty; 663 Suggestion_2 : Entity_Id := Empty; 664 Component_Elmt : Elmt_Id; 665 666 begin 667 -- All the components of List are matched against Component and a count 668 -- is maintained of possible misspellings. When at the end of the 669 -- analysis there are one or two (not more) possible misspellings, 670 -- these misspellings will be suggested as possible corrections. 671 672 Component_Elmt := First_Elmt (Elements); 673 while Nr_Of_Suggestions <= Max_Suggestions 674 and then Present (Component_Elmt) 675 loop 676 if Is_Bad_Spelling_Of 677 (Chars (Node (Component_Elmt)), 678 Chars (Component)) 679 then 680 Nr_Of_Suggestions := Nr_Of_Suggestions + 1; 681 682 case Nr_Of_Suggestions is 683 when 1 => Suggestion_1 := Node (Component_Elmt); 684 when 2 => Suggestion_2 := Node (Component_Elmt); 685 when others => null; 686 end case; 687 end if; 688 689 Next_Elmt (Component_Elmt); 690 end loop; 691 692 -- Report at most two suggestions 693 694 if Nr_Of_Suggestions = 1 then 695 Error_Msg_NE -- CODEFIX 696 ("\possible misspelling of&", Component, Suggestion_1); 697 698 elsif Nr_Of_Suggestions = 2 then 699 Error_Msg_Node_2 := Suggestion_2; 700 Error_Msg_NE -- CODEFIX 701 ("\possible misspelling of& or&", Component, Suggestion_1); 702 end if; 703 end Check_Misspelled_Component; 704 705 ---------------------------------------- 706 -- Check_Expr_OK_In_Limited_Aggregate -- 707 ---------------------------------------- 708 709 procedure Check_Expr_OK_In_Limited_Aggregate (Expr : Node_Id) is 710 begin 711 if Is_Limited_Type (Etype (Expr)) 712 and then Comes_From_Source (Expr) 713 then 714 if In_Instance_Body or else In_Inlined_Body then 715 null; 716 717 elsif not OK_For_Limited_Init (Etype (Expr), Expr) then 718 Error_Msg_N 719 ("initialization not allowed for limited types", Expr); 720 Explain_Limited_Type (Etype (Expr), Expr); 721 end if; 722 end if; 723 end Check_Expr_OK_In_Limited_Aggregate; 724 725 ------------------------------- 726 -- Check_Qualified_Aggregate -- 727 ------------------------------- 728 729 procedure Check_Qualified_Aggregate (Level : Nat; Expr : Node_Id) is 730 Comp_Expr : Node_Id; 731 Comp_Assn : Node_Id; 732 733 begin 734 if Level = 0 then 735 if Nkind (Parent (Expr)) /= N_Qualified_Expression then 736 Check_SPARK_05_Restriction ("aggregate should be qualified", Expr); 737 end if; 738 739 else 740 Comp_Expr := First (Expressions (Expr)); 741 while Present (Comp_Expr) loop 742 if Nkind (Comp_Expr) = N_Aggregate then 743 Check_Qualified_Aggregate (Level - 1, Comp_Expr); 744 end if; 745 746 Comp_Expr := Next (Comp_Expr); 747 end loop; 748 749 Comp_Assn := First (Component_Associations (Expr)); 750 while Present (Comp_Assn) loop 751 Comp_Expr := Expression (Comp_Assn); 752 753 if Nkind (Comp_Expr) = N_Aggregate then 754 Check_Qualified_Aggregate (Level - 1, Comp_Expr); 755 end if; 756 757 Comp_Assn := Next (Comp_Assn); 758 end loop; 759 end if; 760 end Check_Qualified_Aggregate; 761 762 ---------------------------------------- 763 -- Check_Static_Discriminated_Subtype -- 764 ---------------------------------------- 765 766 procedure Check_Static_Discriminated_Subtype (T : Entity_Id; V : Node_Id) is 767 Disc : constant Entity_Id := First_Discriminant (T); 768 Comp : Entity_Id; 769 Ind : Entity_Id; 770 771 begin 772 if Has_Record_Rep_Clause (T) then 773 return; 774 775 elsif Present (Next_Discriminant (Disc)) then 776 return; 777 778 elsif Nkind (V) /= N_Integer_Literal then 779 return; 780 end if; 781 782 Comp := First_Component (T); 783 while Present (Comp) loop 784 if Is_Scalar_Type (Etype (Comp)) then 785 null; 786 787 elsif Is_Private_Type (Etype (Comp)) 788 and then Present (Full_View (Etype (Comp))) 789 and then Is_Scalar_Type (Full_View (Etype (Comp))) 790 then 791 null; 792 793 elsif Is_Array_Type (Etype (Comp)) then 794 if Is_Bit_Packed_Array (Etype (Comp)) then 795 return; 796 end if; 797 798 Ind := First_Index (Etype (Comp)); 799 while Present (Ind) loop 800 if Nkind (Ind) /= N_Range 801 or else Nkind (Low_Bound (Ind)) /= N_Integer_Literal 802 or else Nkind (High_Bound (Ind)) /= N_Integer_Literal 803 then 804 return; 805 end if; 806 807 Next_Index (Ind); 808 end loop; 809 810 else 811 return; 812 end if; 813 814 Next_Component (Comp); 815 end loop; 816 817 -- On exit, all components have statically known sizes 818 819 Set_Size_Known_At_Compile_Time (T); 820 end Check_Static_Discriminated_Subtype; 821 822 ------------------------- 823 -- Is_Others_Aggregate -- 824 ------------------------- 825 826 function Is_Others_Aggregate (Aggr : Node_Id) return Boolean is 827 begin 828 return No (Expressions (Aggr)) 829 and then 830 Nkind (First (Choice_List (First (Component_Associations (Aggr))))) = 831 N_Others_Choice; 832 end Is_Others_Aggregate; 833 834 ---------------------------- 835 -- Is_Top_Level_Aggregate -- 836 ---------------------------- 837 838 function Is_Top_Level_Aggregate (Expr : Node_Id) return Boolean is 839 begin 840 return Nkind (Parent (Expr)) /= N_Aggregate 841 and then (Nkind (Parent (Expr)) /= N_Component_Association 842 or else Nkind (Parent (Parent (Expr))) /= N_Aggregate); 843 end Is_Top_Level_Aggregate; 844 845 -------------------------------- 846 -- Make_String_Into_Aggregate -- 847 -------------------------------- 848 849 procedure Make_String_Into_Aggregate (N : Node_Id) is 850 Exprs : constant List_Id := New_List; 851 Loc : constant Source_Ptr := Sloc (N); 852 Str : constant String_Id := Strval (N); 853 Strlen : constant Nat := String_Length (Str); 854 C : Char_Code; 855 C_Node : Node_Id; 856 New_N : Node_Id; 857 P : Source_Ptr; 858 859 begin 860 P := Loc + 1; 861 for J in 1 .. Strlen loop 862 C := Get_String_Char (Str, J); 863 Set_Character_Literal_Name (C); 864 865 C_Node := 866 Make_Character_Literal (P, 867 Chars => Name_Find, 868 Char_Literal_Value => UI_From_CC (C)); 869 Set_Etype (C_Node, Any_Character); 870 Append_To (Exprs, C_Node); 871 872 P := P + 1; 873 -- Something special for wide strings??? 874 end loop; 875 876 New_N := Make_Aggregate (Loc, Expressions => Exprs); 877 Set_Analyzed (New_N); 878 Set_Etype (New_N, Any_Composite); 879 880 Rewrite (N, New_N); 881 end Make_String_Into_Aggregate; 882 883 ----------------------- 884 -- Resolve_Aggregate -- 885 ----------------------- 886 887 procedure Resolve_Aggregate (N : Node_Id; Typ : Entity_Id) is 888 Loc : constant Source_Ptr := Sloc (N); 889 Pkind : constant Node_Kind := Nkind (Parent (N)); 890 891 Aggr_Subtyp : Entity_Id; 892 -- The actual aggregate subtype. This is not necessarily the same as Typ 893 -- which is the subtype of the context in which the aggregate was found. 894 895 begin 896 -- Ignore junk empty aggregate resulting from parser error 897 898 if No (Expressions (N)) 899 and then No (Component_Associations (N)) 900 and then not Null_Record_Present (N) 901 then 902 return; 903 end if; 904 905 -- If the aggregate has box-initialized components, its type must be 906 -- frozen so that initialization procedures can properly be called 907 -- in the resolution that follows. The replacement of boxes with 908 -- initialization calls is properly an expansion activity but it must 909 -- be done during resolution. 910 911 if Expander_Active 912 and then Present (Component_Associations (N)) 913 then 914 declare 915 Comp : Node_Id; 916 917 begin 918 Comp := First (Component_Associations (N)); 919 while Present (Comp) loop 920 if Box_Present (Comp) then 921 Insert_Actions (N, Freeze_Entity (Typ, N)); 922 exit; 923 end if; 924 925 Next (Comp); 926 end loop; 927 end; 928 end if; 929 930 -- An unqualified aggregate is restricted in SPARK to: 931 932 -- An aggregate item inside an aggregate for a multi-dimensional array 933 934 -- An expression being assigned to an unconstrained array, but only if 935 -- the aggregate specifies a value for OTHERS only. 936 937 if Nkind (Parent (N)) = N_Qualified_Expression then 938 if Is_Array_Type (Typ) then 939 Check_Qualified_Aggregate (Number_Dimensions (Typ), N); 940 else 941 Check_Qualified_Aggregate (1, N); 942 end if; 943 else 944 if Is_Array_Type (Typ) 945 and then Nkind (Parent (N)) = N_Assignment_Statement 946 and then not Is_Constrained (Etype (Name (Parent (N)))) 947 then 948 if not Is_Others_Aggregate (N) then 949 Check_SPARK_05_Restriction 950 ("array aggregate should have only OTHERS", N); 951 end if; 952 953 elsif Is_Top_Level_Aggregate (N) then 954 Check_SPARK_05_Restriction ("aggregate should be qualified", N); 955 956 -- The legality of this unqualified aggregate is checked by calling 957 -- Check_Qualified_Aggregate from one of its enclosing aggregate, 958 -- unless one of these already causes an error to be issued. 959 960 else 961 null; 962 end if; 963 end if; 964 965 -- Check for aggregates not allowed in configurable run-time mode. 966 -- We allow all cases of aggregates that do not come from source, since 967 -- these are all assumed to be small (e.g. bounds of a string literal). 968 -- We also allow aggregates of types we know to be small. 969 970 if not Support_Aggregates_On_Target 971 and then Comes_From_Source (N) 972 and then (not Known_Static_Esize (Typ) or else Esize (Typ) > 64) 973 then 974 Error_Msg_CRT ("aggregate", N); 975 end if; 976 977 -- Ada 2005 (AI-287): Limited aggregates allowed 978 979 -- In an instance, ignore aggregate subcomponents tnat may be limited, 980 -- because they originate in view conflicts. If the original aggregate 981 -- is legal and the actuals are legal, the aggregate itself is legal. 982 983 if Is_Limited_Type (Typ) 984 and then Ada_Version < Ada_2005 985 and then not In_Instance 986 then 987 Error_Msg_N ("aggregate type cannot be limited", N); 988 Explain_Limited_Type (Typ, N); 989 990 elsif Is_Class_Wide_Type (Typ) then 991 Error_Msg_N ("type of aggregate cannot be class-wide", N); 992 993 elsif Typ = Any_String 994 or else Typ = Any_Composite 995 then 996 Error_Msg_N ("no unique type for aggregate", N); 997 Set_Etype (N, Any_Composite); 998 999 elsif Is_Array_Type (Typ) and then Null_Record_Present (N) then 1000 Error_Msg_N ("null record forbidden in array aggregate", N); 1001 1002 elsif Is_Record_Type (Typ) then 1003 Resolve_Record_Aggregate (N, Typ); 1004 1005 elsif Is_Array_Type (Typ) then 1006 1007 -- First a special test, for the case of a positional aggregate of 1008 -- characters which can be replaced by a string literal. 1009 1010 -- Do not perform this transformation if this was a string literal 1011 -- to start with, whose components needed constraint checks, or if 1012 -- the component type is non-static, because it will require those 1013 -- checks and be transformed back into an aggregate. If the index 1014 -- type is not Integer the aggregate may represent a user-defined 1015 -- string type but the context might need the original type so we 1016 -- do not perform the transformation at this point. 1017 1018 if Number_Dimensions (Typ) = 1 1019 and then Is_Standard_Character_Type (Component_Type (Typ)) 1020 and then No (Component_Associations (N)) 1021 and then not Is_Limited_Composite (Typ) 1022 and then not Is_Private_Composite (Typ) 1023 and then not Is_Bit_Packed_Array (Typ) 1024 and then Nkind (Original_Node (Parent (N))) /= N_String_Literal 1025 and then Is_OK_Static_Subtype (Component_Type (Typ)) 1026 and then Base_Type (Etype (First_Index (Typ))) = 1027 Base_Type (Standard_Integer) 1028 then 1029 declare 1030 Expr : Node_Id; 1031 1032 begin 1033 Expr := First (Expressions (N)); 1034 while Present (Expr) loop 1035 exit when Nkind (Expr) /= N_Character_Literal; 1036 Next (Expr); 1037 end loop; 1038 1039 if No (Expr) then 1040 Start_String; 1041 1042 Expr := First (Expressions (N)); 1043 while Present (Expr) loop 1044 Store_String_Char (UI_To_CC (Char_Literal_Value (Expr))); 1045 Next (Expr); 1046 end loop; 1047 1048 Rewrite (N, Make_String_Literal (Loc, End_String)); 1049 1050 Analyze_And_Resolve (N, Typ); 1051 return; 1052 end if; 1053 end; 1054 end if; 1055 1056 -- Here if we have a real aggregate to deal with 1057 1058 Array_Aggregate : declare 1059 Aggr_Resolved : Boolean; 1060 1061 Aggr_Typ : constant Entity_Id := Etype (Typ); 1062 -- This is the unconstrained array type, which is the type against 1063 -- which the aggregate is to be resolved. Typ itself is the array 1064 -- type of the context which may not be the same subtype as the 1065 -- subtype for the final aggregate. 1066 1067 begin 1068 -- In the following we determine whether an OTHERS choice is 1069 -- allowed inside the array aggregate. The test checks the context 1070 -- in which the array aggregate occurs. If the context does not 1071 -- permit it, or the aggregate type is unconstrained, an OTHERS 1072 -- choice is not allowed (except that it is always allowed on the 1073 -- right-hand side of an assignment statement; in this case the 1074 -- constrainedness of the type doesn't matter). 1075 1076 -- If expansion is disabled (generic context, or semantics-only 1077 -- mode) actual subtypes cannot be constructed, and the type of an 1078 -- object may be its unconstrained nominal type. However, if the 1079 -- context is an assignment, we assume that OTHERS is allowed, 1080 -- because the target of the assignment will have a constrained 1081 -- subtype when fully compiled. Ditto if the context is an 1082 -- initialization procedure where a component may have a predicate 1083 -- function that carries the base type. 1084 1085 -- Note that there is no node for Explicit_Actual_Parameter. 1086 -- To test for this context we therefore have to test for node 1087 -- N_Parameter_Association which itself appears only if there is a 1088 -- formal parameter. Consequently we also need to test for 1089 -- N_Procedure_Call_Statement or N_Function_Call. 1090 1091 -- The context may be an N_Reference node, created by expansion. 1092 -- Legality of the others clause was established in the source, 1093 -- so the context is legal. 1094 1095 Set_Etype (N, Aggr_Typ); -- May be overridden later on 1096 1097 if Pkind = N_Assignment_Statement 1098 or else Inside_Init_Proc 1099 or else (Is_Constrained (Typ) 1100 and then 1101 (Pkind = N_Parameter_Association or else 1102 Pkind = N_Function_Call or else 1103 Pkind = N_Procedure_Call_Statement or else 1104 Pkind = N_Generic_Association or else 1105 Pkind = N_Formal_Object_Declaration or else 1106 Pkind = N_Simple_Return_Statement or else 1107 Pkind = N_Object_Declaration or else 1108 Pkind = N_Component_Declaration or else 1109 Pkind = N_Parameter_Specification or else 1110 Pkind = N_Qualified_Expression or else 1111 Pkind = N_Reference or else 1112 Pkind = N_Aggregate or else 1113 Pkind = N_Extension_Aggregate or else 1114 Pkind = N_Component_Association)) 1115 then 1116 Aggr_Resolved := 1117 Resolve_Array_Aggregate 1118 (N, 1119 Index => First_Index (Aggr_Typ), 1120 Index_Constr => First_Index (Typ), 1121 Component_Typ => Component_Type (Typ), 1122 Others_Allowed => True); 1123 else 1124 Aggr_Resolved := 1125 Resolve_Array_Aggregate 1126 (N, 1127 Index => First_Index (Aggr_Typ), 1128 Index_Constr => First_Index (Aggr_Typ), 1129 Component_Typ => Component_Type (Typ), 1130 Others_Allowed => False); 1131 end if; 1132 1133 if not Aggr_Resolved then 1134 1135 -- A parenthesized expression may have been intended as an 1136 -- aggregate, leading to a type error when analyzing the 1137 -- component. This can also happen for a nested component 1138 -- (see Analyze_Aggr_Expr). 1139 1140 if Paren_Count (N) > 0 then 1141 Error_Msg_N 1142 ("positional aggregate cannot have one component", N); 1143 end if; 1144 1145 Aggr_Subtyp := Any_Composite; 1146 1147 else 1148 Aggr_Subtyp := Array_Aggr_Subtype (N, Typ); 1149 end if; 1150 1151 Set_Etype (N, Aggr_Subtyp); 1152 end Array_Aggregate; 1153 1154 elsif Is_Private_Type (Typ) 1155 and then Present (Full_View (Typ)) 1156 and then (In_Inlined_Body or In_Instance_Body) 1157 and then Is_Composite_Type (Full_View (Typ)) 1158 then 1159 Resolve (N, Full_View (Typ)); 1160 1161 else 1162 Error_Msg_N ("illegal context for aggregate", N); 1163 end if; 1164 1165 -- If we can determine statically that the evaluation of the aggregate 1166 -- raises Constraint_Error, then replace the aggregate with an 1167 -- N_Raise_Constraint_Error node, but set the Etype to the right 1168 -- aggregate subtype. Gigi needs this. 1169 1170 if Raises_Constraint_Error (N) then 1171 Aggr_Subtyp := Etype (N); 1172 Rewrite (N, 1173 Make_Raise_Constraint_Error (Loc, Reason => CE_Range_Check_Failed)); 1174 Set_Raises_Constraint_Error (N); 1175 Set_Etype (N, Aggr_Subtyp); 1176 Set_Analyzed (N); 1177 end if; 1178 1179 Check_Function_Writable_Actuals (N); 1180 end Resolve_Aggregate; 1181 1182 ----------------------------- 1183 -- Resolve_Array_Aggregate -- 1184 ----------------------------- 1185 1186 function Resolve_Array_Aggregate 1187 (N : Node_Id; 1188 Index : Node_Id; 1189 Index_Constr : Node_Id; 1190 Component_Typ : Entity_Id; 1191 Others_Allowed : Boolean) return Boolean 1192 is 1193 Loc : constant Source_Ptr := Sloc (N); 1194 1195 Failure : constant Boolean := False; 1196 Success : constant Boolean := True; 1197 1198 Index_Typ : constant Entity_Id := Etype (Index); 1199 Index_Typ_Low : constant Node_Id := Type_Low_Bound (Index_Typ); 1200 Index_Typ_High : constant Node_Id := Type_High_Bound (Index_Typ); 1201 -- The type of the index corresponding to the array sub-aggregate along 1202 -- with its low and upper bounds. 1203 1204 Index_Base : constant Entity_Id := Base_Type (Index_Typ); 1205 Index_Base_Low : constant Node_Id := Type_Low_Bound (Index_Base); 1206 Index_Base_High : constant Node_Id := Type_High_Bound (Index_Base); 1207 -- Ditto for the base type 1208 1209 Others_Present : Boolean := False; 1210 1211 Nb_Choices : Nat := 0; 1212 -- Contains the overall number of named choices in this sub-aggregate 1213 1214 function Add (Val : Uint; To : Node_Id) return Node_Id; 1215 -- Creates a new expression node where Val is added to expression To. 1216 -- Tries to constant fold whenever possible. To must be an already 1217 -- analyzed expression. 1218 1219 procedure Check_Bound (BH : Node_Id; AH : in out Node_Id); 1220 -- Checks that AH (the upper bound of an array aggregate) is less than 1221 -- or equal to BH (the upper bound of the index base type). If the check 1222 -- fails, a warning is emitted, the Raises_Constraint_Error flag of N is 1223 -- set, and AH is replaced with a duplicate of BH. 1224 1225 procedure Check_Bounds (L, H : Node_Id; AL, AH : Node_Id); 1226 -- Checks that range AL .. AH is compatible with range L .. H. Emits a 1227 -- warning if not and sets the Raises_Constraint_Error flag in N. 1228 1229 procedure Check_Length (L, H : Node_Id; Len : Uint); 1230 -- Checks that range L .. H contains at least Len elements. Emits a 1231 -- warning if not and sets the Raises_Constraint_Error flag in N. 1232 1233 function Dynamic_Or_Null_Range (L, H : Node_Id) return Boolean; 1234 -- Returns True if range L .. H is dynamic or null 1235 1236 procedure Get (Value : out Uint; From : Node_Id; OK : out Boolean); 1237 -- Given expression node From, this routine sets OK to False if it 1238 -- cannot statically evaluate From. Otherwise it stores this static 1239 -- value into Value. 1240 1241 function Resolve_Aggr_Expr 1242 (Expr : Node_Id; 1243 Single_Elmt : Boolean) return Boolean; 1244 -- Resolves aggregate expression Expr. Returns False if resolution 1245 -- fails. If Single_Elmt is set to False, the expression Expr may be 1246 -- used to initialize several array aggregate elements (this can happen 1247 -- for discrete choices such as "L .. H => Expr" or the OTHERS choice). 1248 -- In this event we do not resolve Expr unless expansion is disabled. 1249 -- To know why, see the DELAYED COMPONENT RESOLUTION note above. 1250 -- 1251 -- NOTE: In the case of "... => <>", we pass the in the 1252 -- N_Component_Association node as Expr, since there is no Expression in 1253 -- that case, and we need a Sloc for the error message. 1254 1255 procedure Resolve_Iterated_Component_Association 1256 (N : Node_Id; 1257 Index_Typ : Entity_Id); 1258 -- For AI12-061 1259 1260 --------- 1261 -- Add -- 1262 --------- 1263 1264 function Add (Val : Uint; To : Node_Id) return Node_Id is 1265 Expr_Pos : Node_Id; 1266 Expr : Node_Id; 1267 To_Pos : Node_Id; 1268 1269 begin 1270 if Raises_Constraint_Error (To) then 1271 return To; 1272 end if; 1273 1274 -- First test if we can do constant folding 1275 1276 if Compile_Time_Known_Value (To) 1277 or else Nkind (To) = N_Integer_Literal 1278 then 1279 Expr_Pos := Make_Integer_Literal (Loc, Expr_Value (To) + Val); 1280 Set_Is_Static_Expression (Expr_Pos); 1281 Set_Etype (Expr_Pos, Etype (To)); 1282 Set_Analyzed (Expr_Pos, Analyzed (To)); 1283 1284 if not Is_Enumeration_Type (Index_Typ) then 1285 Expr := Expr_Pos; 1286 1287 -- If we are dealing with enumeration return 1288 -- Index_Typ'Val (Expr_Pos) 1289 1290 else 1291 Expr := 1292 Make_Attribute_Reference 1293 (Loc, 1294 Prefix => New_Occurrence_Of (Index_Typ, Loc), 1295 Attribute_Name => Name_Val, 1296 Expressions => New_List (Expr_Pos)); 1297 end if; 1298 1299 return Expr; 1300 end if; 1301 1302 -- If we are here no constant folding possible 1303 1304 if not Is_Enumeration_Type (Index_Base) then 1305 Expr := 1306 Make_Op_Add (Loc, 1307 Left_Opnd => Duplicate_Subexpr (To), 1308 Right_Opnd => Make_Integer_Literal (Loc, Val)); 1309 1310 -- If we are dealing with enumeration return 1311 -- Index_Typ'Val (Index_Typ'Pos (To) + Val) 1312 1313 else 1314 To_Pos := 1315 Make_Attribute_Reference 1316 (Loc, 1317 Prefix => New_Occurrence_Of (Index_Typ, Loc), 1318 Attribute_Name => Name_Pos, 1319 Expressions => New_List (Duplicate_Subexpr (To))); 1320 1321 Expr_Pos := 1322 Make_Op_Add (Loc, 1323 Left_Opnd => To_Pos, 1324 Right_Opnd => Make_Integer_Literal (Loc, Val)); 1325 1326 Expr := 1327 Make_Attribute_Reference 1328 (Loc, 1329 Prefix => New_Occurrence_Of (Index_Typ, Loc), 1330 Attribute_Name => Name_Val, 1331 Expressions => New_List (Expr_Pos)); 1332 1333 -- If the index type has a non standard representation, the 1334 -- attributes 'Val and 'Pos expand into function calls and the 1335 -- resulting expression is considered non-safe for reevaluation 1336 -- by the backend. Relocate it into a constant temporary in order 1337 -- to make it safe for reevaluation. 1338 1339 if Has_Non_Standard_Rep (Etype (N)) then 1340 declare 1341 Def_Id : Entity_Id; 1342 1343 begin 1344 Def_Id := Make_Temporary (Loc, 'R', Expr); 1345 Set_Etype (Def_Id, Index_Typ); 1346 Insert_Action (N, 1347 Make_Object_Declaration (Loc, 1348 Defining_Identifier => Def_Id, 1349 Object_Definition => 1350 New_Occurrence_Of (Index_Typ, Loc), 1351 Constant_Present => True, 1352 Expression => Relocate_Node (Expr))); 1353 1354 Expr := New_Occurrence_Of (Def_Id, Loc); 1355 end; 1356 end if; 1357 end if; 1358 1359 return Expr; 1360 end Add; 1361 1362 ----------------- 1363 -- Check_Bound -- 1364 ----------------- 1365 1366 procedure Check_Bound (BH : Node_Id; AH : in out Node_Id) is 1367 Val_BH : Uint; 1368 Val_AH : Uint; 1369 1370 OK_BH : Boolean; 1371 OK_AH : Boolean; 1372 1373 begin 1374 Get (Value => Val_BH, From => BH, OK => OK_BH); 1375 Get (Value => Val_AH, From => AH, OK => OK_AH); 1376 1377 if OK_BH and then OK_AH and then Val_BH < Val_AH then 1378 Set_Raises_Constraint_Error (N); 1379 Error_Msg_Warn := SPARK_Mode /= On; 1380 Error_Msg_N ("upper bound out of range<<", AH); 1381 Error_Msg_N ("\Constraint_Error [<<", AH); 1382 1383 -- You need to set AH to BH or else in the case of enumerations 1384 -- indexes we will not be able to resolve the aggregate bounds. 1385 1386 AH := Duplicate_Subexpr (BH); 1387 end if; 1388 end Check_Bound; 1389 1390 ------------------ 1391 -- Check_Bounds -- 1392 ------------------ 1393 1394 procedure Check_Bounds (L, H : Node_Id; AL, AH : Node_Id) is 1395 Val_L : Uint; 1396 Val_H : Uint; 1397 Val_AL : Uint; 1398 Val_AH : Uint; 1399 1400 OK_L : Boolean; 1401 OK_H : Boolean; 1402 1403 OK_AL : Boolean; 1404 OK_AH : Boolean; 1405 pragma Warnings (Off, OK_AL); 1406 pragma Warnings (Off, OK_AH); 1407 1408 begin 1409 if Raises_Constraint_Error (N) 1410 or else Dynamic_Or_Null_Range (AL, AH) 1411 then 1412 return; 1413 end if; 1414 1415 Get (Value => Val_L, From => L, OK => OK_L); 1416 Get (Value => Val_H, From => H, OK => OK_H); 1417 1418 Get (Value => Val_AL, From => AL, OK => OK_AL); 1419 Get (Value => Val_AH, From => AH, OK => OK_AH); 1420 1421 if OK_L and then Val_L > Val_AL then 1422 Set_Raises_Constraint_Error (N); 1423 Error_Msg_Warn := SPARK_Mode /= On; 1424 Error_Msg_N ("lower bound of aggregate out of range<<", N); 1425 Error_Msg_N ("\Constraint_Error [<<", N); 1426 end if; 1427 1428 if OK_H and then Val_H < Val_AH then 1429 Set_Raises_Constraint_Error (N); 1430 Error_Msg_Warn := SPARK_Mode /= On; 1431 Error_Msg_N ("upper bound of aggregate out of range<<", N); 1432 Error_Msg_N ("\Constraint_Error [<<", N); 1433 end if; 1434 end Check_Bounds; 1435 1436 ------------------ 1437 -- Check_Length -- 1438 ------------------ 1439 1440 procedure Check_Length (L, H : Node_Id; Len : Uint) is 1441 Val_L : Uint; 1442 Val_H : Uint; 1443 1444 OK_L : Boolean; 1445 OK_H : Boolean; 1446 1447 Range_Len : Uint; 1448 1449 begin 1450 if Raises_Constraint_Error (N) then 1451 return; 1452 end if; 1453 1454 Get (Value => Val_L, From => L, OK => OK_L); 1455 Get (Value => Val_H, From => H, OK => OK_H); 1456 1457 if not OK_L or else not OK_H then 1458 return; 1459 end if; 1460 1461 -- If null range length is zero 1462 1463 if Val_L > Val_H then 1464 Range_Len := Uint_0; 1465 else 1466 Range_Len := Val_H - Val_L + 1; 1467 end if; 1468 1469 if Range_Len < Len then 1470 Set_Raises_Constraint_Error (N); 1471 Error_Msg_Warn := SPARK_Mode /= On; 1472 Error_Msg_N ("too many elements<<", N); 1473 Error_Msg_N ("\Constraint_Error [<<", N); 1474 end if; 1475 end Check_Length; 1476 1477 --------------------------- 1478 -- Dynamic_Or_Null_Range -- 1479 --------------------------- 1480 1481 function Dynamic_Or_Null_Range (L, H : Node_Id) return Boolean is 1482 Val_L : Uint; 1483 Val_H : Uint; 1484 1485 OK_L : Boolean; 1486 OK_H : Boolean; 1487 1488 begin 1489 Get (Value => Val_L, From => L, OK => OK_L); 1490 Get (Value => Val_H, From => H, OK => OK_H); 1491 1492 return not OK_L or else not OK_H 1493 or else not Is_OK_Static_Expression (L) 1494 or else not Is_OK_Static_Expression (H) 1495 or else Val_L > Val_H; 1496 end Dynamic_Or_Null_Range; 1497 1498 --------- 1499 -- Get -- 1500 --------- 1501 1502 procedure Get (Value : out Uint; From : Node_Id; OK : out Boolean) is 1503 begin 1504 OK := True; 1505 1506 if Compile_Time_Known_Value (From) then 1507 Value := Expr_Value (From); 1508 1509 -- If expression From is something like Some_Type'Val (10) then 1510 -- Value = 10. 1511 1512 elsif Nkind (From) = N_Attribute_Reference 1513 and then Attribute_Name (From) = Name_Val 1514 and then Compile_Time_Known_Value (First (Expressions (From))) 1515 then 1516 Value := Expr_Value (First (Expressions (From))); 1517 else 1518 Value := Uint_0; 1519 OK := False; 1520 end if; 1521 end Get; 1522 1523 ----------------------- 1524 -- Resolve_Aggr_Expr -- 1525 ----------------------- 1526 1527 function Resolve_Aggr_Expr 1528 (Expr : Node_Id; 1529 Single_Elmt : Boolean) return Boolean 1530 is 1531 Nxt_Ind : constant Node_Id := Next_Index (Index); 1532 Nxt_Ind_Constr : constant Node_Id := Next_Index (Index_Constr); 1533 -- Index is the current index corresponding to the expression 1534 1535 Resolution_OK : Boolean := True; 1536 -- Set to False if resolution of the expression failed 1537 1538 begin 1539 -- Defend against previous errors 1540 1541 if Nkind (Expr) = N_Error 1542 or else Error_Posted (Expr) 1543 then 1544 return True; 1545 end if; 1546 1547 -- If the array type against which we are resolving the aggregate 1548 -- has several dimensions, the expressions nested inside the 1549 -- aggregate must be further aggregates (or strings). 1550 1551 if Present (Nxt_Ind) then 1552 if Nkind (Expr) /= N_Aggregate then 1553 1554 -- A string literal can appear where a one-dimensional array 1555 -- of characters is expected. If the literal looks like an 1556 -- operator, it is still an operator symbol, which will be 1557 -- transformed into a string when analyzed. 1558 1559 if Is_Character_Type (Component_Typ) 1560 and then No (Next_Index (Nxt_Ind)) 1561 and then Nkind_In (Expr, N_String_Literal, N_Operator_Symbol) 1562 then 1563 -- A string literal used in a multidimensional array 1564 -- aggregate in place of the final one-dimensional 1565 -- aggregate must not be enclosed in parentheses. 1566 1567 if Paren_Count (Expr) /= 0 then 1568 Error_Msg_N ("no parenthesis allowed here", Expr); 1569 end if; 1570 1571 Make_String_Into_Aggregate (Expr); 1572 1573 else 1574 Error_Msg_N ("nested array aggregate expected", Expr); 1575 1576 -- If the expression is parenthesized, this may be 1577 -- a missing component association for a 1-aggregate. 1578 1579 if Paren_Count (Expr) > 0 then 1580 Error_Msg_N 1581 ("\if single-component aggregate is intended, " 1582 & "write e.g. (1 ='> ...)", Expr); 1583 end if; 1584 1585 return Failure; 1586 end if; 1587 end if; 1588 1589 -- If it's "... => <>", nothing to resolve 1590 1591 if Nkind (Expr) = N_Component_Association then 1592 pragma Assert (Box_Present (Expr)); 1593 return Success; 1594 end if; 1595 1596 -- Ada 2005 (AI-231): Propagate the type to the nested aggregate. 1597 -- Required to check the null-exclusion attribute (if present). 1598 -- This value may be overridden later on. 1599 1600 Set_Etype (Expr, Etype (N)); 1601 1602 Resolution_OK := Resolve_Array_Aggregate 1603 (Expr, Nxt_Ind, Nxt_Ind_Constr, Component_Typ, Others_Allowed); 1604 1605 else 1606 -- If it's "... => <>", nothing to resolve 1607 1608 if Nkind (Expr) = N_Component_Association then 1609 pragma Assert (Box_Present (Expr)); 1610 return Success; 1611 end if; 1612 1613 -- Do not resolve the expressions of discrete or others choices 1614 -- unless the expression covers a single component, or the 1615 -- expander is inactive. 1616 1617 -- In SPARK mode, expressions that can perform side effects will 1618 -- be recognized by the gnat2why back-end, and the whole 1619 -- subprogram will be ignored. So semantic analysis can be 1620 -- performed safely. 1621 1622 if Single_Elmt 1623 or else not Expander_Active 1624 or else In_Spec_Expression 1625 then 1626 Analyze_And_Resolve (Expr, Component_Typ); 1627 Check_Expr_OK_In_Limited_Aggregate (Expr); 1628 Check_Non_Static_Context (Expr); 1629 Aggregate_Constraint_Checks (Expr, Component_Typ); 1630 Check_Unset_Reference (Expr); 1631 end if; 1632 end if; 1633 1634 -- If an aggregate component has a type with predicates, an explicit 1635 -- predicate check must be applied, as for an assignment statement, 1636 -- because the aggegate might not be expanded into individual 1637 -- component assignments. If the expression covers several components 1638 -- the analysis and the predicate check take place later. 1639 1640 if Has_Predicates (Component_Typ) 1641 and then Analyzed (Expr) 1642 then 1643 Apply_Predicate_Check (Expr, Component_Typ); 1644 end if; 1645 1646 if Raises_Constraint_Error (Expr) 1647 and then Nkind (Parent (Expr)) /= N_Component_Association 1648 then 1649 Set_Raises_Constraint_Error (N); 1650 end if; 1651 1652 -- If the expression has been marked as requiring a range check, 1653 -- then generate it here. It's a bit odd to be generating such 1654 -- checks in the analyzer, but harmless since Generate_Range_Check 1655 -- does nothing (other than making sure Do_Range_Check is set) if 1656 -- the expander is not active. 1657 1658 if Do_Range_Check (Expr) then 1659 Generate_Range_Check (Expr, Component_Typ, CE_Range_Check_Failed); 1660 end if; 1661 1662 return Resolution_OK; 1663 end Resolve_Aggr_Expr; 1664 1665 -------------------------------------------- 1666 -- Resolve_Iterated_Component_Association -- 1667 -------------------------------------------- 1668 1669 procedure Resolve_Iterated_Component_Association 1670 (N : Node_Id; 1671 Index_Typ : Entity_Id) 1672 is 1673 Loc : constant Source_Ptr := Sloc (N); 1674 1675 Choice : Node_Id; 1676 Dummy : Boolean; 1677 Ent : Entity_Id; 1678 Expr : Node_Id; 1679 Id : Entity_Id; 1680 1681 begin 1682 Choice := First (Discrete_Choices (N)); 1683 1684 while Present (Choice) loop 1685 if Nkind (Choice) = N_Others_Choice then 1686 Others_Present := True; 1687 1688 else 1689 Analyze (Choice); 1690 1691 -- Choice can be a subtype name, a range, or an expression 1692 1693 if Is_Entity_Name (Choice) 1694 and then Is_Type (Entity (Choice)) 1695 and then Base_Type (Entity (Choice)) = Base_Type (Index_Typ) 1696 then 1697 null; 1698 1699 else 1700 Analyze_And_Resolve (Choice, Index_Typ); 1701 end if; 1702 end if; 1703 1704 Next (Choice); 1705 end loop; 1706 1707 -- Create a scope in which to introduce an index, which is usually 1708 -- visible in the expression for the component, and needed for its 1709 -- analysis. 1710 1711 Ent := New_Internal_Entity (E_Loop, Current_Scope, Loc, 'L'); 1712 Set_Etype (Ent, Standard_Void_Type); 1713 Set_Parent (Ent, Parent (N)); 1714 Push_Scope (Ent); 1715 Id := 1716 Make_Defining_Identifier (Loc, 1717 Chars => Chars (Defining_Identifier (N))); 1718 1719 -- Insert and decorate the index variable in the current scope. 1720 -- The expression has to be analyzed once the index variable is 1721 -- directly visible. Mark the variable as referenced to prevent 1722 -- spurious warnings, given that subsequent uses of its name in the 1723 -- expression will reference the internal (synonym) loop variable. 1724 1725 Enter_Name (Id); 1726 Set_Etype (Id, Index_Typ); 1727 Set_Ekind (Id, E_Variable); 1728 Set_Scope (Id, Ent); 1729 Set_Referenced (Id); 1730 1731 -- Analyze a copy of the expression, to verify legality. We use 1732 -- a copy because the expression will be analyzed anew when the 1733 -- enclosing aggregate is expanded, and the construct is rewritten 1734 -- as a loop with a new index variable. 1735 1736 Expr := New_Copy_Tree (Expression (N)); 1737 Dummy := Resolve_Aggr_Expr (Expr, False); 1738 1739 -- An iterated_component_association may appear in a nested 1740 -- aggregate for a multidimensional structure: preserve the bounds 1741 -- computed for the expression, as well as the anonymous array 1742 -- type generated for it; both are needed during array expansion. 1743 -- This does not work for more than two levels of nesting. ??? 1744 1745 if Nkind (Expr) = N_Aggregate then 1746 Set_Aggregate_Bounds (Expression (N), Aggregate_Bounds (Expr)); 1747 Set_Etype (Expression (N), Etype (Expr)); 1748 end if; 1749 1750 End_Scope; 1751 end Resolve_Iterated_Component_Association; 1752 1753 -- Local variables 1754 1755 Assoc : Node_Id; 1756 Choice : Node_Id; 1757 Expr : Node_Id; 1758 Discard : Node_Id; 1759 1760 Aggr_Low : Node_Id := Empty; 1761 Aggr_High : Node_Id := Empty; 1762 -- The actual low and high bounds of this sub-aggregate 1763 1764 Case_Table_Size : Nat; 1765 -- Contains the size of the case table needed to sort aggregate choices 1766 1767 Choices_Low : Node_Id := Empty; 1768 Choices_High : Node_Id := Empty; 1769 -- The lowest and highest discrete choices values for a named aggregate 1770 1771 Delete_Choice : Boolean; 1772 -- Used when replacing a subtype choice with predicate by a list 1773 1774 Nb_Elements : Uint := Uint_0; 1775 -- The number of elements in a positional aggregate 1776 1777 Nb_Discrete_Choices : Nat := 0; 1778 -- The overall number of discrete choices (not counting others choice) 1779 1780 -- Start of processing for Resolve_Array_Aggregate 1781 1782 begin 1783 -- Ignore junk empty aggregate resulting from parser error 1784 1785 if No (Expressions (N)) 1786 and then No (Component_Associations (N)) 1787 and then not Null_Record_Present (N) 1788 then 1789 return False; 1790 end if; 1791 1792 -- STEP 1: make sure the aggregate is correctly formatted 1793 1794 if Present (Component_Associations (N)) then 1795 Assoc := First (Component_Associations (N)); 1796 while Present (Assoc) loop 1797 if Nkind (Assoc) = N_Iterated_Component_Association then 1798 Resolve_Iterated_Component_Association (Assoc, Index_Typ); 1799 end if; 1800 1801 Choice := First (Choice_List (Assoc)); 1802 Delete_Choice := False; 1803 while Present (Choice) loop 1804 if Nkind (Choice) = N_Others_Choice then 1805 Others_Present := True; 1806 1807 if Choice /= First (Choice_List (Assoc)) 1808 or else Present (Next (Choice)) 1809 then 1810 Error_Msg_N 1811 ("OTHERS must appear alone in a choice list", Choice); 1812 return Failure; 1813 end if; 1814 1815 if Present (Next (Assoc)) then 1816 Error_Msg_N 1817 ("OTHERS must appear last in an aggregate", Choice); 1818 return Failure; 1819 end if; 1820 1821 if Ada_Version = Ada_83 1822 and then Assoc /= First (Component_Associations (N)) 1823 and then Nkind_In (Parent (N), N_Assignment_Statement, 1824 N_Object_Declaration) 1825 then 1826 Error_Msg_N 1827 ("(Ada 83) illegal context for OTHERS choice", N); 1828 end if; 1829 1830 elsif Is_Entity_Name (Choice) then 1831 Analyze (Choice); 1832 1833 declare 1834 E : constant Entity_Id := Entity (Choice); 1835 New_Cs : List_Id; 1836 P : Node_Id; 1837 C : Node_Id; 1838 1839 begin 1840 if Is_Type (E) and then Has_Predicates (E) then 1841 Freeze_Before (N, E); 1842 1843 if Has_Dynamic_Predicate_Aspect (E) then 1844 Error_Msg_NE 1845 ("subtype& has dynamic predicate, not allowed " 1846 & "in aggregate choice", Choice, E); 1847 1848 elsif not Is_OK_Static_Subtype (E) then 1849 Error_Msg_NE 1850 ("non-static subtype& has predicate, not allowed " 1851 & "in aggregate choice", Choice, E); 1852 end if; 1853 1854 -- If the subtype has a static predicate, replace the 1855 -- original choice with the list of individual values 1856 -- covered by the predicate. Do not perform this 1857 -- transformation if we need to preserve the source 1858 -- for ASIS use. 1859 -- This should be deferred to expansion time ??? 1860 1861 if Present (Static_Discrete_Predicate (E)) 1862 and then not ASIS_Mode 1863 then 1864 Delete_Choice := True; 1865 1866 New_Cs := New_List; 1867 P := First (Static_Discrete_Predicate (E)); 1868 while Present (P) loop 1869 C := New_Copy (P); 1870 Set_Sloc (C, Sloc (Choice)); 1871 Append_To (New_Cs, C); 1872 Next (P); 1873 end loop; 1874 1875 Insert_List_After (Choice, New_Cs); 1876 end if; 1877 end if; 1878 end; 1879 end if; 1880 1881 Nb_Choices := Nb_Choices + 1; 1882 1883 declare 1884 C : constant Node_Id := Choice; 1885 1886 begin 1887 Next (Choice); 1888 1889 if Delete_Choice then 1890 Remove (C); 1891 Nb_Choices := Nb_Choices - 1; 1892 Delete_Choice := False; 1893 end if; 1894 end; 1895 end loop; 1896 1897 Next (Assoc); 1898 end loop; 1899 end if; 1900 1901 -- At this point we know that the others choice, if present, is by 1902 -- itself and appears last in the aggregate. Check if we have mixed 1903 -- positional and discrete associations (other than the others choice). 1904 1905 if Present (Expressions (N)) 1906 and then (Nb_Choices > 1 1907 or else (Nb_Choices = 1 and then not Others_Present)) 1908 then 1909 Error_Msg_N 1910 ("named association cannot follow positional association", 1911 First (Choice_List (First (Component_Associations (N))))); 1912 return Failure; 1913 end if; 1914 1915 -- Test for the validity of an others choice if present 1916 1917 if Others_Present and then not Others_Allowed then 1918 Error_Msg_N 1919 ("OTHERS choice not allowed here", 1920 First (Choices (First (Component_Associations (N))))); 1921 return Failure; 1922 end if; 1923 1924 -- Protect against cascaded errors 1925 1926 if Etype (Index_Typ) = Any_Type then 1927 return Failure; 1928 end if; 1929 1930 -- STEP 2: Process named components 1931 1932 if No (Expressions (N)) then 1933 if Others_Present then 1934 Case_Table_Size := Nb_Choices - 1; 1935 else 1936 Case_Table_Size := Nb_Choices; 1937 end if; 1938 1939 Step_2 : declare 1940 function Empty_Range (A : Node_Id) return Boolean; 1941 -- If an association covers an empty range, some warnings on the 1942 -- expression of the association can be disabled. 1943 1944 ----------------- 1945 -- Empty_Range -- 1946 ----------------- 1947 1948 function Empty_Range (A : Node_Id) return Boolean is 1949 R : constant Node_Id := First (Choices (A)); 1950 begin 1951 return No (Next (R)) 1952 and then Nkind (R) = N_Range 1953 and then Compile_Time_Compare 1954 (Low_Bound (R), High_Bound (R), False) = GT; 1955 end Empty_Range; 1956 1957 -- Local variables 1958 1959 Low : Node_Id; 1960 High : Node_Id; 1961 -- Denote the lowest and highest values in an aggregate choice 1962 1963 S_Low : Node_Id := Empty; 1964 S_High : Node_Id := Empty; 1965 -- if a choice in an aggregate is a subtype indication these 1966 -- denote the lowest and highest values of the subtype 1967 1968 Table : Case_Table_Type (0 .. Case_Table_Size); 1969 -- Used to sort all the different choice values. Entry zero is 1970 -- reserved for sorting purposes. 1971 1972 Single_Choice : Boolean; 1973 -- Set to true every time there is a single discrete choice in a 1974 -- discrete association 1975 1976 Prev_Nb_Discrete_Choices : Nat; 1977 -- Used to keep track of the number of discrete choices in the 1978 -- current association. 1979 1980 Errors_Posted_On_Choices : Boolean := False; 1981 -- Keeps track of whether any choices have semantic errors 1982 1983 -- Start of processing for Step_2 1984 1985 begin 1986 -- STEP 2 (A): Check discrete choices validity 1987 1988 Assoc := First (Component_Associations (N)); 1989 while Present (Assoc) loop 1990 Prev_Nb_Discrete_Choices := Nb_Discrete_Choices; 1991 Choice := First (Choice_List (Assoc)); 1992 1993 loop 1994 Analyze (Choice); 1995 1996 if Nkind (Choice) = N_Others_Choice then 1997 Single_Choice := False; 1998 exit; 1999 2000 -- Test for subtype mark without constraint 2001 2002 elsif Is_Entity_Name (Choice) and then 2003 Is_Type (Entity (Choice)) 2004 then 2005 if Base_Type (Entity (Choice)) /= Index_Base then 2006 Error_Msg_N 2007 ("invalid subtype mark in aggregate choice", 2008 Choice); 2009 return Failure; 2010 end if; 2011 2012 -- Case of subtype indication 2013 2014 elsif Nkind (Choice) = N_Subtype_Indication then 2015 Resolve_Discrete_Subtype_Indication (Choice, Index_Base); 2016 2017 if Has_Dynamic_Predicate_Aspect 2018 (Entity (Subtype_Mark (Choice))) 2019 then 2020 Error_Msg_NE 2021 ("subtype& has dynamic predicate, " 2022 & "not allowed in aggregate choice", 2023 Choice, Entity (Subtype_Mark (Choice))); 2024 end if; 2025 2026 -- Does the subtype indication evaluation raise CE? 2027 2028 Get_Index_Bounds (Subtype_Mark (Choice), S_Low, S_High); 2029 Get_Index_Bounds (Choice, Low, High); 2030 Check_Bounds (S_Low, S_High, Low, High); 2031 2032 -- Case of range or expression 2033 2034 else 2035 Resolve (Choice, Index_Base); 2036 Check_Unset_Reference (Choice); 2037 Check_Non_Static_Context (Choice); 2038 2039 -- If semantic errors were posted on the choice, then 2040 -- record that for possible early return from later 2041 -- processing (see handling of enumeration choices). 2042 2043 if Error_Posted (Choice) then 2044 Errors_Posted_On_Choices := True; 2045 end if; 2046 2047 -- Do not range check a choice. This check is redundant 2048 -- since this test is already done when we check that the 2049 -- bounds of the array aggregate are within range. 2050 2051 Set_Do_Range_Check (Choice, False); 2052 2053 -- In SPARK, the choice must be static 2054 2055 if not (Is_OK_Static_Expression (Choice) 2056 or else (Nkind (Choice) = N_Range 2057 and then Is_OK_Static_Range (Choice))) 2058 then 2059 Check_SPARK_05_Restriction 2060 ("choice should be static", Choice); 2061 end if; 2062 end if; 2063 2064 -- If we could not resolve the discrete choice stop here 2065 2066 if Etype (Choice) = Any_Type then 2067 return Failure; 2068 2069 -- If the discrete choice raises CE get its original bounds 2070 2071 elsif Nkind (Choice) = N_Raise_Constraint_Error then 2072 Set_Raises_Constraint_Error (N); 2073 Get_Index_Bounds (Original_Node (Choice), Low, High); 2074 2075 -- Otherwise get its bounds as usual 2076 2077 else 2078 Get_Index_Bounds (Choice, Low, High); 2079 end if; 2080 2081 if (Dynamic_Or_Null_Range (Low, High) 2082 or else (Nkind (Choice) = N_Subtype_Indication 2083 and then 2084 Dynamic_Or_Null_Range (S_Low, S_High))) 2085 and then Nb_Choices /= 1 2086 then 2087 Error_Msg_N 2088 ("dynamic or empty choice in aggregate " 2089 & "must be the only choice", Choice); 2090 return Failure; 2091 end if; 2092 2093 if not (All_Composite_Constraints_Static (Low) 2094 and then All_Composite_Constraints_Static (High) 2095 and then All_Composite_Constraints_Static (S_Low) 2096 and then All_Composite_Constraints_Static (S_High)) 2097 then 2098 Check_Restriction (No_Dynamic_Sized_Objects, Choice); 2099 end if; 2100 2101 Nb_Discrete_Choices := Nb_Discrete_Choices + 1; 2102 Table (Nb_Discrete_Choices).Lo := Low; 2103 Table (Nb_Discrete_Choices).Hi := High; 2104 Table (Nb_Discrete_Choices).Choice := Choice; 2105 2106 Next (Choice); 2107 2108 if No (Choice) then 2109 2110 -- Check if we have a single discrete choice and whether 2111 -- this discrete choice specifies a single value. 2112 2113 Single_Choice := 2114 (Nb_Discrete_Choices = Prev_Nb_Discrete_Choices + 1) 2115 and then (Low = High); 2116 2117 exit; 2118 end if; 2119 end loop; 2120 2121 -- Ada 2005 (AI-231) 2122 2123 if Ada_Version >= Ada_2005 2124 and then Known_Null (Expression (Assoc)) 2125 and then not Empty_Range (Assoc) 2126 then 2127 Check_Can_Never_Be_Null (Etype (N), Expression (Assoc)); 2128 end if; 2129 2130 -- Ada 2005 (AI-287): In case of default initialized component 2131 -- we delay the resolution to the expansion phase. 2132 2133 if Box_Present (Assoc) then 2134 2135 -- Ada 2005 (AI-287): In case of default initialization of a 2136 -- component the expander will generate calls to the 2137 -- corresponding initialization subprogram. We need to call 2138 -- Resolve_Aggr_Expr to check the rules about 2139 -- dimensionality. 2140 2141 if not Resolve_Aggr_Expr 2142 (Assoc, Single_Elmt => Single_Choice) 2143 then 2144 return Failure; 2145 end if; 2146 2147 elsif Nkind (Assoc) = N_Iterated_Component_Association then 2148 null; -- handled above, in a loop context. 2149 2150 elsif not Resolve_Aggr_Expr 2151 (Expression (Assoc), Single_Elmt => Single_Choice) 2152 then 2153 return Failure; 2154 2155 -- Check incorrect use of dynamically tagged expression 2156 2157 -- We differentiate here two cases because the expression may 2158 -- not be decorated. For example, the analysis and resolution 2159 -- of the expression associated with the others choice will be 2160 -- done later with the full aggregate. In such case we 2161 -- duplicate the expression tree to analyze the copy and 2162 -- perform the required check. 2163 2164 elsif not Present (Etype (Expression (Assoc))) then 2165 declare 2166 Save_Analysis : constant Boolean := Full_Analysis; 2167 Expr : constant Node_Id := 2168 New_Copy_Tree (Expression (Assoc)); 2169 2170 begin 2171 Expander_Mode_Save_And_Set (False); 2172 Full_Analysis := False; 2173 2174 -- Analyze the expression, making sure it is properly 2175 -- attached to the tree before we do the analysis. 2176 2177 Set_Parent (Expr, Parent (Expression (Assoc))); 2178 Analyze (Expr); 2179 2180 -- Compute its dimensions now, rather than at the end of 2181 -- resolution, because in the case of multidimensional 2182 -- aggregates subsequent expansion may lead to spurious 2183 -- errors. 2184 2185 Check_Expression_Dimensions (Expr, Component_Typ); 2186 2187 -- If the expression is a literal, propagate this info 2188 -- to the expression in the association, to enable some 2189 -- optimizations downstream. 2190 2191 if Is_Entity_Name (Expr) 2192 and then Present (Entity (Expr)) 2193 and then Ekind (Entity (Expr)) = E_Enumeration_Literal 2194 then 2195 Analyze_And_Resolve 2196 (Expression (Assoc), Component_Typ); 2197 end if; 2198 2199 Full_Analysis := Save_Analysis; 2200 Expander_Mode_Restore; 2201 2202 if Is_Tagged_Type (Etype (Expr)) then 2203 Check_Dynamically_Tagged_Expression 2204 (Expr => Expr, 2205 Typ => Component_Type (Etype (N)), 2206 Related_Nod => N); 2207 end if; 2208 end; 2209 2210 elsif Is_Tagged_Type (Etype (Expression (Assoc))) then 2211 Check_Dynamically_Tagged_Expression 2212 (Expr => Expression (Assoc), 2213 Typ => Component_Type (Etype (N)), 2214 Related_Nod => N); 2215 end if; 2216 2217 Next (Assoc); 2218 end loop; 2219 2220 -- If aggregate contains more than one choice then these must be 2221 -- static. Check for duplicate and missing values. 2222 2223 -- Note: there is duplicated code here wrt Check_Choice_Set in 2224 -- the body of Sem_Case, and it is possible we could just reuse 2225 -- that procedure. To be checked ??? 2226 2227 if Nb_Discrete_Choices > 1 then 2228 Check_Choices : declare 2229 Choice : Node_Id; 2230 -- Location of choice for messages 2231 2232 Hi_Val : Uint; 2233 Lo_Val : Uint; 2234 -- High end of one range and Low end of the next. Should be 2235 -- contiguous if there is no hole in the list of values. 2236 2237 Lo_Dup : Uint; 2238 Hi_Dup : Uint; 2239 -- End points of duplicated range 2240 2241 Missing_Or_Duplicates : Boolean := False; 2242 -- Set True if missing or duplicate choices found 2243 2244 procedure Output_Bad_Choices (Lo, Hi : Uint; C : Node_Id); 2245 -- Output continuation message with a representation of the 2246 -- bounds (just Lo if Lo = Hi, else Lo .. Hi). C is the 2247 -- choice node where the message is to be posted. 2248 2249 ------------------------ 2250 -- Output_Bad_Choices -- 2251 ------------------------ 2252 2253 procedure Output_Bad_Choices (Lo, Hi : Uint; C : Node_Id) is 2254 begin 2255 -- Enumeration type case 2256 2257 if Is_Enumeration_Type (Index_Typ) then 2258 Error_Msg_Name_1 := 2259 Chars (Get_Enum_Lit_From_Pos (Index_Typ, Lo, Loc)); 2260 Error_Msg_Name_2 := 2261 Chars (Get_Enum_Lit_From_Pos (Index_Typ, Hi, Loc)); 2262 2263 if Lo = Hi then 2264 Error_Msg_N ("\\ %!", C); 2265 else 2266 Error_Msg_N ("\\ % .. %!", C); 2267 end if; 2268 2269 -- Integer types case 2270 2271 else 2272 Error_Msg_Uint_1 := Lo; 2273 Error_Msg_Uint_2 := Hi; 2274 2275 if Lo = Hi then 2276 Error_Msg_N ("\\ ^!", C); 2277 else 2278 Error_Msg_N ("\\ ^ .. ^!", C); 2279 end if; 2280 end if; 2281 end Output_Bad_Choices; 2282 2283 -- Start of processing for Check_Choices 2284 2285 begin 2286 Sort_Case_Table (Table); 2287 2288 -- First we do a quick linear loop to find out if we have 2289 -- any duplicates or missing entries (usually we have a 2290 -- legal aggregate, so this will get us out quickly). 2291 2292 for J in 1 .. Nb_Discrete_Choices - 1 loop 2293 Hi_Val := Expr_Value (Table (J).Hi); 2294 Lo_Val := Expr_Value (Table (J + 1).Lo); 2295 2296 if Lo_Val <= Hi_Val 2297 or else (Lo_Val > Hi_Val + 1 2298 and then not Others_Present) 2299 then 2300 Missing_Or_Duplicates := True; 2301 exit; 2302 end if; 2303 end loop; 2304 2305 -- If we have missing or duplicate entries, first fill in 2306 -- the Highest entries to make life easier in the following 2307 -- loops to detect bad entries. 2308 2309 if Missing_Or_Duplicates then 2310 Table (1).Highest := Expr_Value (Table (1).Hi); 2311 2312 for J in 2 .. Nb_Discrete_Choices loop 2313 Table (J).Highest := 2314 UI_Max 2315 (Table (J - 1).Highest, Expr_Value (Table (J).Hi)); 2316 end loop; 2317 2318 -- Loop through table entries to find duplicate indexes 2319 2320 for J in 2 .. Nb_Discrete_Choices loop 2321 Lo_Val := Expr_Value (Table (J).Lo); 2322 Hi_Val := Expr_Value (Table (J).Hi); 2323 2324 -- Case where we have duplicates (the lower bound of 2325 -- this choice is less than or equal to the highest 2326 -- high bound found so far). 2327 2328 if Lo_Val <= Table (J - 1).Highest then 2329 2330 -- We move backwards looking for duplicates. We can 2331 -- abandon this loop as soon as we reach a choice 2332 -- highest value that is less than Lo_Val. 2333 2334 for K in reverse 1 .. J - 1 loop 2335 exit when Table (K).Highest < Lo_Val; 2336 2337 -- Here we may have duplicates between entries 2338 -- for K and J. Get range of duplicates. 2339 2340 Lo_Dup := 2341 UI_Max (Lo_Val, Expr_Value (Table (K).Lo)); 2342 Hi_Dup := 2343 UI_Min (Hi_Val, Expr_Value (Table (K).Hi)); 2344 2345 -- Nothing to do if duplicate range is null 2346 2347 if Lo_Dup > Hi_Dup then 2348 null; 2349 2350 -- Otherwise place proper message. Because 2351 -- of the missing expansion of subtypes with 2352 -- predicates in ASIS mode, do not report 2353 -- spurious overlap errors. 2354 2355 elsif ASIS_Mode 2356 and then 2357 ((Is_Type (Entity (Table (J).Choice)) 2358 and then Has_Predicates 2359 (Entity (Table (J).Choice))) 2360 or else 2361 (Is_Type (Entity (Table (K).Choice)) 2362 and then Has_Predicates 2363 (Entity (Table (K).Choice)))) 2364 then 2365 null; 2366 2367 else 2368 -- We place message on later choice, with a 2369 -- line reference to the earlier choice. 2370 2371 if Sloc (Table (J).Choice) < 2372 Sloc (Table (K).Choice) 2373 then 2374 Choice := Table (K).Choice; 2375 Error_Msg_Sloc := Sloc (Table (J).Choice); 2376 else 2377 Choice := Table (J).Choice; 2378 Error_Msg_Sloc := Sloc (Table (K).Choice); 2379 end if; 2380 2381 if Lo_Dup = Hi_Dup then 2382 Error_Msg_N 2383 ("index value in array aggregate " 2384 & "duplicates the one given#!", Choice); 2385 else 2386 Error_Msg_N 2387 ("index values in array aggregate " 2388 & "duplicate those given#!", Choice); 2389 end if; 2390 2391 Output_Bad_Choices (Lo_Dup, Hi_Dup, Choice); 2392 end if; 2393 end loop; 2394 end if; 2395 end loop; 2396 2397 -- Loop through entries in table to find missing indexes. 2398 -- Not needed if others, since missing impossible. 2399 2400 if not Others_Present then 2401 for J in 2 .. Nb_Discrete_Choices loop 2402 Lo_Val := Expr_Value (Table (J).Lo); 2403 Hi_Val := Table (J - 1).Highest; 2404 2405 if Lo_Val > Hi_Val + 1 then 2406 2407 declare 2408 Error_Node : Node_Id; 2409 2410 begin 2411 -- If the choice is the bound of a range in 2412 -- a subtype indication, it is not in the 2413 -- source lists for the aggregate itself, so 2414 -- post the error on the aggregate. Otherwise 2415 -- post it on choice itself. 2416 2417 Choice := Table (J).Choice; 2418 2419 if Is_List_Member (Choice) then 2420 Error_Node := Choice; 2421 else 2422 Error_Node := N; 2423 end if; 2424 2425 if Hi_Val + 1 = Lo_Val - 1 then 2426 Error_Msg_N 2427 ("missing index value " 2428 & "in array aggregate!", Error_Node); 2429 else 2430 Error_Msg_N 2431 ("missing index values " 2432 & "in array aggregate!", Error_Node); 2433 end if; 2434 2435 Output_Bad_Choices 2436 (Hi_Val + 1, Lo_Val - 1, Error_Node); 2437 end; 2438 end if; 2439 end loop; 2440 end if; 2441 2442 -- If either missing or duplicate values, return failure 2443 2444 Set_Etype (N, Any_Composite); 2445 return Failure; 2446 end if; 2447 end Check_Choices; 2448 end if; 2449 2450 -- STEP 2 (B): Compute aggregate bounds and min/max choices values 2451 2452 if Nb_Discrete_Choices > 0 then 2453 Choices_Low := Table (1).Lo; 2454 Choices_High := Table (Nb_Discrete_Choices).Hi; 2455 end if; 2456 2457 -- If Others is present, then bounds of aggregate come from the 2458 -- index constraint (not the choices in the aggregate itself). 2459 2460 if Others_Present then 2461 Get_Index_Bounds (Index_Constr, Aggr_Low, Aggr_High); 2462 2463 -- Abandon processing if either bound is already signalled as 2464 -- an error (prevents junk cascaded messages and blow ups). 2465 2466 if Nkind (Aggr_Low) = N_Error 2467 or else 2468 Nkind (Aggr_High) = N_Error 2469 then 2470 return False; 2471 end if; 2472 2473 -- No others clause present 2474 2475 else 2476 -- Special processing if others allowed and not present. This 2477 -- means that the bounds of the aggregate come from the index 2478 -- constraint (and the length must match). 2479 2480 if Others_Allowed then 2481 Get_Index_Bounds (Index_Constr, Aggr_Low, Aggr_High); 2482 2483 -- Abandon processing if either bound is already signalled 2484 -- as an error (stop junk cascaded messages and blow ups). 2485 2486 if Nkind (Aggr_Low) = N_Error 2487 or else 2488 Nkind (Aggr_High) = N_Error 2489 then 2490 return False; 2491 end if; 2492 2493 -- If others allowed, and no others present, then the array 2494 -- should cover all index values. If it does not, we will 2495 -- get a length check warning, but there is two cases where 2496 -- an additional warning is useful: 2497 2498 -- If we have no positional components, and the length is 2499 -- wrong (which we can tell by others being allowed with 2500 -- missing components), and the index type is an enumeration 2501 -- type, then issue appropriate warnings about these missing 2502 -- components. They are only warnings, since the aggregate 2503 -- is fine, it's just the wrong length. We skip this check 2504 -- for standard character types (since there are no literals 2505 -- and it is too much trouble to concoct them), and also if 2506 -- any of the bounds have values that are not known at 2507 -- compile time. 2508 2509 -- Another case warranting a warning is when the length 2510 -- is right, but as above we have an index type that is 2511 -- an enumeration, and the bounds do not match. This is a 2512 -- case where dubious sliding is allowed and we generate a 2513 -- warning that the bounds do not match. 2514 2515 if No (Expressions (N)) 2516 and then Nkind (Index) = N_Range 2517 and then Is_Enumeration_Type (Etype (Index)) 2518 and then not Is_Standard_Character_Type (Etype (Index)) 2519 and then Compile_Time_Known_Value (Aggr_Low) 2520 and then Compile_Time_Known_Value (Aggr_High) 2521 and then Compile_Time_Known_Value (Choices_Low) 2522 and then Compile_Time_Known_Value (Choices_High) 2523 then 2524 -- If any of the expressions or range bounds in choices 2525 -- have semantic errors, then do not attempt further 2526 -- resolution, to prevent cascaded errors. 2527 2528 if Errors_Posted_On_Choices then 2529 return Failure; 2530 end if; 2531 2532 declare 2533 ALo : constant Node_Id := Expr_Value_E (Aggr_Low); 2534 AHi : constant Node_Id := Expr_Value_E (Aggr_High); 2535 CLo : constant Node_Id := Expr_Value_E (Choices_Low); 2536 CHi : constant Node_Id := Expr_Value_E (Choices_High); 2537 2538 Ent : Entity_Id; 2539 2540 begin 2541 -- Warning case 1, missing values at start/end. Only 2542 -- do the check if the number of entries is too small. 2543 2544 if (Enumeration_Pos (CHi) - Enumeration_Pos (CLo)) 2545 < 2546 (Enumeration_Pos (AHi) - Enumeration_Pos (ALo)) 2547 then 2548 Error_Msg_N 2549 ("missing index value(s) in array aggregate??", 2550 N); 2551 2552 -- Output missing value(s) at start 2553 2554 if Chars (ALo) /= Chars (CLo) then 2555 Ent := Prev (CLo); 2556 2557 if Chars (ALo) = Chars (Ent) then 2558 Error_Msg_Name_1 := Chars (ALo); 2559 Error_Msg_N ("\ %??", N); 2560 else 2561 Error_Msg_Name_1 := Chars (ALo); 2562 Error_Msg_Name_2 := Chars (Ent); 2563 Error_Msg_N ("\ % .. %??", N); 2564 end if; 2565 end if; 2566 2567 -- Output missing value(s) at end 2568 2569 if Chars (AHi) /= Chars (CHi) then 2570 Ent := Next (CHi); 2571 2572 if Chars (AHi) = Chars (Ent) then 2573 Error_Msg_Name_1 := Chars (Ent); 2574 Error_Msg_N ("\ %??", N); 2575 else 2576 Error_Msg_Name_1 := Chars (Ent); 2577 Error_Msg_Name_2 := Chars (AHi); 2578 Error_Msg_N ("\ % .. %??", N); 2579 end if; 2580 end if; 2581 2582 -- Warning case 2, dubious sliding. The First_Subtype 2583 -- test distinguishes between a constrained type where 2584 -- sliding is not allowed (so we will get a warning 2585 -- later that Constraint_Error will be raised), and 2586 -- the unconstrained case where sliding is permitted. 2587 2588 elsif (Enumeration_Pos (CHi) - Enumeration_Pos (CLo)) 2589 = 2590 (Enumeration_Pos (AHi) - Enumeration_Pos (ALo)) 2591 and then Chars (ALo) /= Chars (CLo) 2592 and then 2593 not Is_Constrained (First_Subtype (Etype (N))) 2594 then 2595 Error_Msg_N 2596 ("bounds of aggregate do not match target??", N); 2597 end if; 2598 end; 2599 end if; 2600 end if; 2601 2602 -- If no others, aggregate bounds come from aggregate 2603 2604 Aggr_Low := Choices_Low; 2605 Aggr_High := Choices_High; 2606 end if; 2607 end Step_2; 2608 2609 -- STEP 3: Process positional components 2610 2611 else 2612 -- STEP 3 (A): Process positional elements 2613 2614 Expr := First (Expressions (N)); 2615 Nb_Elements := Uint_0; 2616 while Present (Expr) loop 2617 Nb_Elements := Nb_Elements + 1; 2618 2619 -- Ada 2005 (AI-231) 2620 2621 if Ada_Version >= Ada_2005 and then Known_Null (Expr) then 2622 Check_Can_Never_Be_Null (Etype (N), Expr); 2623 end if; 2624 2625 if not Resolve_Aggr_Expr (Expr, Single_Elmt => True) then 2626 return Failure; 2627 end if; 2628 2629 -- Check incorrect use of dynamically tagged expression 2630 2631 if Is_Tagged_Type (Etype (Expr)) then 2632 Check_Dynamically_Tagged_Expression 2633 (Expr => Expr, 2634 Typ => Component_Type (Etype (N)), 2635 Related_Nod => N); 2636 end if; 2637 2638 Next (Expr); 2639 end loop; 2640 2641 if Others_Present then 2642 Assoc := Last (Component_Associations (N)); 2643 2644 -- Ada 2005 (AI-231) 2645 2646 if Ada_Version >= Ada_2005 and then Known_Null (Assoc) then 2647 Check_Can_Never_Be_Null (Etype (N), Expression (Assoc)); 2648 end if; 2649 2650 -- Ada 2005 (AI-287): In case of default initialized component, 2651 -- we delay the resolution to the expansion phase. 2652 2653 if Box_Present (Assoc) then 2654 2655 -- Ada 2005 (AI-287): In case of default initialization of a 2656 -- component the expander will generate calls to the 2657 -- corresponding initialization subprogram. We need to call 2658 -- Resolve_Aggr_Expr to check the rules about 2659 -- dimensionality. 2660 2661 if not Resolve_Aggr_Expr (Assoc, Single_Elmt => False) then 2662 return Failure; 2663 end if; 2664 2665 elsif not Resolve_Aggr_Expr (Expression (Assoc), 2666 Single_Elmt => False) 2667 then 2668 return Failure; 2669 2670 -- Check incorrect use of dynamically tagged expression. The 2671 -- expression of the others choice has not been resolved yet. 2672 -- In order to diagnose the semantic error we create a duplicate 2673 -- tree to analyze it and perform the check. 2674 2675 else 2676 declare 2677 Save_Analysis : constant Boolean := Full_Analysis; 2678 Expr : constant Node_Id := 2679 New_Copy_Tree (Expression (Assoc)); 2680 2681 begin 2682 Expander_Mode_Save_And_Set (False); 2683 Full_Analysis := False; 2684 Analyze (Expr); 2685 Full_Analysis := Save_Analysis; 2686 Expander_Mode_Restore; 2687 2688 if Is_Tagged_Type (Etype (Expr)) then 2689 Check_Dynamically_Tagged_Expression 2690 (Expr => Expr, 2691 Typ => Component_Type (Etype (N)), 2692 Related_Nod => N); 2693 end if; 2694 end; 2695 end if; 2696 end if; 2697 2698 -- STEP 3 (B): Compute the aggregate bounds 2699 2700 if Others_Present then 2701 Get_Index_Bounds (Index_Constr, Aggr_Low, Aggr_High); 2702 2703 else 2704 if Others_Allowed then 2705 Get_Index_Bounds (Index_Constr, Aggr_Low, Discard); 2706 else 2707 Aggr_Low := Index_Typ_Low; 2708 end if; 2709 2710 Aggr_High := Add (Nb_Elements - 1, To => Aggr_Low); 2711 Check_Bound (Index_Base_High, Aggr_High); 2712 end if; 2713 end if; 2714 2715 -- STEP 4: Perform static aggregate checks and save the bounds 2716 2717 -- Check (A) 2718 2719 Check_Bounds (Index_Typ_Low, Index_Typ_High, Aggr_Low, Aggr_High); 2720 Check_Bounds (Index_Base_Low, Index_Base_High, Aggr_Low, Aggr_High); 2721 2722 -- Check (B) 2723 2724 if Others_Present and then Nb_Discrete_Choices > 0 then 2725 Check_Bounds (Aggr_Low, Aggr_High, Choices_Low, Choices_High); 2726 Check_Bounds (Index_Typ_Low, Index_Typ_High, 2727 Choices_Low, Choices_High); 2728 Check_Bounds (Index_Base_Low, Index_Base_High, 2729 Choices_Low, Choices_High); 2730 2731 -- Check (C) 2732 2733 elsif Others_Present and then Nb_Elements > 0 then 2734 Check_Length (Aggr_Low, Aggr_High, Nb_Elements); 2735 Check_Length (Index_Typ_Low, Index_Typ_High, Nb_Elements); 2736 Check_Length (Index_Base_Low, Index_Base_High, Nb_Elements); 2737 end if; 2738 2739 if Raises_Constraint_Error (Aggr_Low) 2740 or else Raises_Constraint_Error (Aggr_High) 2741 then 2742 Set_Raises_Constraint_Error (N); 2743 end if; 2744 2745 Aggr_Low := Duplicate_Subexpr (Aggr_Low); 2746 2747 -- Do not duplicate Aggr_High if Aggr_High = Aggr_Low + Nb_Elements 2748 -- since the addition node returned by Add is not yet analyzed. Attach 2749 -- to tree and analyze first. Reset analyzed flag to ensure it will get 2750 -- analyzed when it is a literal bound whose type must be properly set. 2751 2752 if Others_Present or else Nb_Discrete_Choices > 0 then 2753 Aggr_High := Duplicate_Subexpr (Aggr_High); 2754 2755 if Etype (Aggr_High) = Universal_Integer then 2756 Set_Analyzed (Aggr_High, False); 2757 end if; 2758 end if; 2759 2760 -- If the aggregate already has bounds attached to it, it means this is 2761 -- a positional aggregate created as an optimization by 2762 -- Exp_Aggr.Convert_To_Positional, so we don't want to change those 2763 -- bounds. 2764 2765 if Present (Aggregate_Bounds (N)) and then not Others_Allowed then 2766 Aggr_Low := Low_Bound (Aggregate_Bounds (N)); 2767 Aggr_High := High_Bound (Aggregate_Bounds (N)); 2768 end if; 2769 2770 Set_Aggregate_Bounds 2771 (N, Make_Range (Loc, Low_Bound => Aggr_Low, High_Bound => Aggr_High)); 2772 2773 -- The bounds may contain expressions that must be inserted upwards. 2774 -- Attach them fully to the tree. After analysis, remove side effects 2775 -- from upper bound, if still needed. 2776 2777 Set_Parent (Aggregate_Bounds (N), N); 2778 Analyze_And_Resolve (Aggregate_Bounds (N), Index_Typ); 2779 Check_Unset_Reference (Aggregate_Bounds (N)); 2780 2781 if not Others_Present and then Nb_Discrete_Choices = 0 then 2782 Set_High_Bound 2783 (Aggregate_Bounds (N), 2784 Duplicate_Subexpr (High_Bound (Aggregate_Bounds (N)))); 2785 end if; 2786 2787 -- Check the dimensions of each component in the array aggregate 2788 2789 Analyze_Dimension_Array_Aggregate (N, Component_Typ); 2790 2791 return Success; 2792 end Resolve_Array_Aggregate; 2793 2794 ----------------------------- 2795 -- Resolve_Delta_Aggregate -- 2796 ----------------------------- 2797 2798 procedure Resolve_Delta_Aggregate (N : Node_Id; Typ : Entity_Id) is 2799 Base : constant Node_Id := Expression (N); 2800 2801 begin 2802 if not Is_Composite_Type (Typ) then 2803 Error_Msg_N ("not a composite type", N); 2804 end if; 2805 2806 Analyze_And_Resolve (Base, Typ); 2807 2808 if Is_Array_Type (Typ) then 2809 Resolve_Delta_Array_Aggregate (N, Typ); 2810 else 2811 Resolve_Delta_Record_Aggregate (N, Typ); 2812 end if; 2813 2814 Set_Etype (N, Typ); 2815 end Resolve_Delta_Aggregate; 2816 2817 ----------------------------------- 2818 -- Resolve_Delta_Array_Aggregate -- 2819 ----------------------------------- 2820 2821 procedure Resolve_Delta_Array_Aggregate (N : Node_Id; Typ : Entity_Id) is 2822 Deltas : constant List_Id := Component_Associations (N); 2823 2824 Assoc : Node_Id; 2825 Choice : Node_Id; 2826 Index_Type : Entity_Id; 2827 2828 begin 2829 Index_Type := Etype (First_Index (Typ)); 2830 2831 Assoc := First (Deltas); 2832 while Present (Assoc) loop 2833 if Nkind (Assoc) = N_Iterated_Component_Association then 2834 Choice := First (Choice_List (Assoc)); 2835 while Present (Choice) loop 2836 if Nkind (Choice) = N_Others_Choice then 2837 Error_Msg_N 2838 ("others not allowed in delta aggregate", Choice); 2839 2840 else 2841 Analyze_And_Resolve (Choice, Index_Type); 2842 end if; 2843 2844 Next (Choice); 2845 end loop; 2846 2847 declare 2848 Id : constant Entity_Id := Defining_Identifier (Assoc); 2849 Ent : constant Entity_Id := 2850 New_Internal_Entity 2851 (E_Loop, Current_Scope, Sloc (Assoc), 'L'); 2852 2853 begin 2854 Set_Etype (Ent, Standard_Void_Type); 2855 Set_Parent (Ent, Assoc); 2856 2857 if No (Scope (Id)) then 2858 Enter_Name (Id); 2859 Set_Etype (Id, Index_Type); 2860 Set_Ekind (Id, E_Variable); 2861 Set_Scope (Id, Ent); 2862 end if; 2863 2864 Push_Scope (Ent); 2865 Analyze_And_Resolve 2866 (New_Copy_Tree (Expression (Assoc)), Component_Type (Typ)); 2867 End_Scope; 2868 end; 2869 2870 else 2871 Choice := First (Choice_List (Assoc)); 2872 while Present (Choice) loop 2873 if Nkind (Choice) = N_Others_Choice then 2874 Error_Msg_N 2875 ("others not allowed in delta aggregate", Choice); 2876 2877 else 2878 Analyze (Choice); 2879 2880 if Is_Entity_Name (Choice) 2881 and then Is_Type (Entity (Choice)) 2882 then 2883 -- Choice covers a range of values 2884 2885 if Base_Type (Entity (Choice)) /= 2886 Base_Type (Index_Type) 2887 then 2888 Error_Msg_NE 2889 ("choice does mat match index type of", 2890 Choice, Typ); 2891 end if; 2892 else 2893 Resolve (Choice, Index_Type); 2894 end if; 2895 end if; 2896 2897 Next (Choice); 2898 end loop; 2899 2900 Analyze_And_Resolve (Expression (Assoc), Component_Type (Typ)); 2901 end if; 2902 2903 Next (Assoc); 2904 end loop; 2905 end Resolve_Delta_Array_Aggregate; 2906 2907 ------------------------------------ 2908 -- Resolve_Delta_Record_Aggregate -- 2909 ------------------------------------ 2910 2911 procedure Resolve_Delta_Record_Aggregate (N : Node_Id; Typ : Entity_Id) is 2912 2913 -- Variables used to verify that discriminant-dependent components 2914 -- appear in the same variant. 2915 2916 Comp_Ref : Entity_Id := Empty; -- init to avoid warning 2917 Variant : Node_Id; 2918 2919 procedure Check_Variant (Id : Entity_Id); 2920 -- If a given component of the delta aggregate appears in a variant 2921 -- part, verify that it is within the same variant as that of previous 2922 -- specified variant components of the delta. 2923 2924 function Get_Component_Type (Nam : Node_Id) return Entity_Id; 2925 -- Locate component with a given name and return its type. If none found 2926 -- report error. 2927 2928 function Nested_In (V1 : Node_Id; V2 : Node_Id) return Boolean; 2929 -- Determine whether variant V1 is within variant V2 2930 2931 function Variant_Depth (N : Node_Id) return Integer; 2932 -- Determine the distance of a variant to the enclosing type 2933 -- declaration. 2934 2935 -------------------- 2936 -- Check_Variant -- 2937 -------------------- 2938 2939 procedure Check_Variant (Id : Entity_Id) is 2940 Comp : Entity_Id; 2941 Comp_Variant : Node_Id; 2942 2943 begin 2944 if not Has_Discriminants (Typ) then 2945 return; 2946 end if; 2947 2948 Comp := First_Entity (Typ); 2949 while Present (Comp) loop 2950 exit when Chars (Comp) = Chars (Id); 2951 Next_Component (Comp); 2952 end loop; 2953 2954 -- Find the variant, if any, whose component list includes the 2955 -- component declaration. 2956 2957 Comp_Variant := Parent (Parent (List_Containing (Parent (Comp)))); 2958 if Nkind (Comp_Variant) = N_Variant then 2959 if No (Variant) then 2960 Variant := Comp_Variant; 2961 Comp_Ref := Comp; 2962 2963 elsif Variant /= Comp_Variant then 2964 declare 2965 D1 : constant Integer := Variant_Depth (Variant); 2966 D2 : constant Integer := Variant_Depth (Comp_Variant); 2967 2968 begin 2969 if D1 = D2 2970 or else 2971 (D1 > D2 and then not Nested_In (Variant, Comp_Variant)) 2972 or else 2973 (D2 > D1 and then not Nested_In (Comp_Variant, Variant)) 2974 then 2975 pragma Assert (Present (Comp_Ref)); 2976 Error_Msg_Node_2 := Comp_Ref; 2977 Error_Msg_NE 2978 ("& and & appear in different variants", Id, Comp); 2979 2980 -- Otherwise retain the deeper variant for subsequent tests 2981 2982 elsif D2 > D1 then 2983 Variant := Comp_Variant; 2984 end if; 2985 end; 2986 end if; 2987 end if; 2988 end Check_Variant; 2989 2990 ------------------------ 2991 -- Get_Component_Type -- 2992 ------------------------ 2993 2994 function Get_Component_Type (Nam : Node_Id) return Entity_Id is 2995 Comp : Entity_Id; 2996 2997 begin 2998 Comp := First_Entity (Typ); 2999 while Present (Comp) loop 3000 if Chars (Comp) = Chars (Nam) then 3001 if Ekind (Comp) = E_Discriminant then 3002 Error_Msg_N ("delta cannot apply to discriminant", Nam); 3003 end if; 3004 3005 return Etype (Comp); 3006 end if; 3007 3008 Comp := Next_Entity (Comp); 3009 end loop; 3010 3011 Error_Msg_NE ("type& has no component with this name", Nam, Typ); 3012 return Any_Type; 3013 end Get_Component_Type; 3014 3015 --------------- 3016 -- Nested_In -- 3017 --------------- 3018 3019 function Nested_In (V1, V2 : Node_Id) return Boolean is 3020 Par : Node_Id; 3021 3022 begin 3023 Par := Parent (V1); 3024 while Nkind (Par) /= N_Full_Type_Declaration loop 3025 if Par = V2 then 3026 return True; 3027 end if; 3028 3029 Par := Parent (Par); 3030 end loop; 3031 3032 return False; 3033 end Nested_In; 3034 3035 ------------------- 3036 -- Variant_Depth -- 3037 ------------------- 3038 3039 function Variant_Depth (N : Node_Id) return Integer is 3040 Depth : Integer; 3041 Par : Node_Id; 3042 3043 begin 3044 Depth := 0; 3045 Par := Parent (N); 3046 while Nkind (Par) /= N_Full_Type_Declaration loop 3047 Depth := Depth + 1; 3048 Par := Parent (Par); 3049 end loop; 3050 3051 return Depth; 3052 end Variant_Depth; 3053 3054 -- Local variables 3055 3056 Deltas : constant List_Id := Component_Associations (N); 3057 3058 Assoc : Node_Id; 3059 Choice : Node_Id; 3060 Comp_Type : Entity_Id := Empty; -- init to avoid warning 3061 3062 -- Start of processing for Resolve_Delta_Record_Aggregate 3063 3064 begin 3065 Variant := Empty; 3066 3067 Assoc := First (Deltas); 3068 while Present (Assoc) loop 3069 Choice := First (Choice_List (Assoc)); 3070 while Present (Choice) loop 3071 Comp_Type := Get_Component_Type (Choice); 3072 3073 if Comp_Type /= Any_Type then 3074 Check_Variant (Choice); 3075 end if; 3076 3077 Next (Choice); 3078 end loop; 3079 3080 pragma Assert (Present (Comp_Type)); 3081 Analyze_And_Resolve (Expression (Assoc), Comp_Type); 3082 Next (Assoc); 3083 end loop; 3084 end Resolve_Delta_Record_Aggregate; 3085 3086 --------------------------------- 3087 -- Resolve_Extension_Aggregate -- 3088 --------------------------------- 3089 3090 -- There are two cases to consider: 3091 3092 -- a) If the ancestor part is a type mark, the components needed are the 3093 -- difference between the components of the expected type and the 3094 -- components of the given type mark. 3095 3096 -- b) If the ancestor part is an expression, it must be unambiguous, and 3097 -- once we have its type we can also compute the needed components as in 3098 -- the previous case. In both cases, if the ancestor type is not the 3099 -- immediate ancestor, we have to build this ancestor recursively. 3100 3101 -- In both cases, discriminants of the ancestor type do not play a role in 3102 -- the resolution of the needed components, because inherited discriminants 3103 -- cannot be used in a type extension. As a result we can compute 3104 -- independently the list of components of the ancestor type and of the 3105 -- expected type. 3106 3107 procedure Resolve_Extension_Aggregate (N : Node_Id; Typ : Entity_Id) is 3108 A : constant Node_Id := Ancestor_Part (N); 3109 A_Type : Entity_Id; 3110 I : Interp_Index; 3111 It : Interp; 3112 3113 function Valid_Limited_Ancestor (Anc : Node_Id) return Boolean; 3114 -- If the type is limited, verify that the ancestor part is a legal 3115 -- expression (aggregate or function call, including 'Input)) that does 3116 -- not require a copy, as specified in 7.5(2). 3117 3118 function Valid_Ancestor_Type return Boolean; 3119 -- Verify that the type of the ancestor part is a non-private ancestor 3120 -- of the expected type, which must be a type extension. 3121 3122 procedure Transform_BIP_Assignment (Typ : Entity_Id); 3123 -- For an extension aggregate whose ancestor part is a build-in-place 3124 -- call returning a nonlimited type, this is used to transform the 3125 -- assignment to the ancestor part to use a temp. 3126 3127 ---------------------------- 3128 -- Valid_Limited_Ancestor -- 3129 ---------------------------- 3130 3131 function Valid_Limited_Ancestor (Anc : Node_Id) return Boolean is 3132 begin 3133 if Is_Entity_Name (Anc) and then Is_Type (Entity (Anc)) then 3134 return True; 3135 3136 -- The ancestor must be a call or an aggregate, but a call may 3137 -- have been expanded into a temporary, so check original node. 3138 3139 elsif Nkind_In (Anc, N_Aggregate, 3140 N_Extension_Aggregate, 3141 N_Function_Call) 3142 then 3143 return True; 3144 3145 elsif Nkind (Original_Node (Anc)) = N_Function_Call then 3146 return True; 3147 3148 elsif Nkind (Anc) = N_Attribute_Reference 3149 and then Attribute_Name (Anc) = Name_Input 3150 then 3151 return True; 3152 3153 elsif Nkind (Anc) = N_Qualified_Expression then 3154 return Valid_Limited_Ancestor (Expression (Anc)); 3155 3156 else 3157 return False; 3158 end if; 3159 end Valid_Limited_Ancestor; 3160 3161 ------------------------- 3162 -- Valid_Ancestor_Type -- 3163 ------------------------- 3164 3165 function Valid_Ancestor_Type return Boolean is 3166 Imm_Type : Entity_Id; 3167 3168 begin 3169 Imm_Type := Base_Type (Typ); 3170 while Is_Derived_Type (Imm_Type) loop 3171 if Etype (Imm_Type) = Base_Type (A_Type) then 3172 return True; 3173 3174 -- The base type of the parent type may appear as a private 3175 -- extension if it is declared as such in a parent unit of the 3176 -- current one. For consistency of the subsequent analysis use 3177 -- the partial view for the ancestor part. 3178 3179 elsif Is_Private_Type (Etype (Imm_Type)) 3180 and then Present (Full_View (Etype (Imm_Type))) 3181 and then Base_Type (A_Type) = Full_View (Etype (Imm_Type)) 3182 then 3183 A_Type := Etype (Imm_Type); 3184 return True; 3185 3186 -- The parent type may be a private extension. The aggregate is 3187 -- legal if the type of the aggregate is an extension of it that 3188 -- is not a private extension. 3189 3190 elsif Is_Private_Type (A_Type) 3191 and then not Is_Private_Type (Imm_Type) 3192 and then Present (Full_View (A_Type)) 3193 and then Base_Type (Full_View (A_Type)) = Etype (Imm_Type) 3194 then 3195 return True; 3196 3197 else 3198 Imm_Type := Etype (Base_Type (Imm_Type)); 3199 end if; 3200 end loop; 3201 3202 -- If previous loop did not find a proper ancestor, report error 3203 3204 Error_Msg_NE ("expect ancestor type of &", A, Typ); 3205 return False; 3206 end Valid_Ancestor_Type; 3207 3208 ------------------------------ 3209 -- Transform_BIP_Assignment -- 3210 ------------------------------ 3211 3212 procedure Transform_BIP_Assignment (Typ : Entity_Id) is 3213 Loc : constant Source_Ptr := Sloc (N); 3214 Def_Id : constant Entity_Id := Make_Temporary (Loc, 'Y', A); 3215 Obj_Decl : constant Node_Id := 3216 Make_Object_Declaration (Loc, 3217 Defining_Identifier => Def_Id, 3218 Constant_Present => True, 3219 Object_Definition => New_Occurrence_Of (Typ, Loc), 3220 Expression => A, 3221 Has_Init_Expression => True); 3222 begin 3223 Set_Etype (Def_Id, Typ); 3224 Set_Ancestor_Part (N, New_Occurrence_Of (Def_Id, Loc)); 3225 Insert_Action (N, Obj_Decl); 3226 end Transform_BIP_Assignment; 3227 3228 -- Start of processing for Resolve_Extension_Aggregate 3229 3230 begin 3231 -- Analyze the ancestor part and account for the case where it is a 3232 -- parameterless function call. 3233 3234 Analyze (A); 3235 Check_Parameterless_Call (A); 3236 3237 -- In SPARK, the ancestor part cannot be a type mark 3238 3239 if Is_Entity_Name (A) and then Is_Type (Entity (A)) then 3240 Check_SPARK_05_Restriction ("ancestor part cannot be a type mark", A); 3241 3242 -- AI05-0115: if the ancestor part is a subtype mark, the ancestor 3243 -- must not have unknown discriminants. 3244 3245 if Has_Unknown_Discriminants (Root_Type (Typ)) then 3246 Error_Msg_NE 3247 ("aggregate not available for type& whose ancestor " 3248 & "has unknown discriminants", N, Typ); 3249 end if; 3250 end if; 3251 3252 if not Is_Tagged_Type (Typ) then 3253 Error_Msg_N ("type of extension aggregate must be tagged", N); 3254 return; 3255 3256 elsif Is_Limited_Type (Typ) then 3257 3258 -- Ada 2005 (AI-287): Limited aggregates are allowed 3259 3260 if Ada_Version < Ada_2005 then 3261 Error_Msg_N ("aggregate type cannot be limited", N); 3262 Explain_Limited_Type (Typ, N); 3263 return; 3264 3265 elsif Valid_Limited_Ancestor (A) then 3266 null; 3267 3268 else 3269 Error_Msg_N 3270 ("limited ancestor part must be aggregate or function call", A); 3271 end if; 3272 3273 elsif Is_Class_Wide_Type (Typ) then 3274 Error_Msg_N ("aggregate cannot be of a class-wide type", N); 3275 return; 3276 end if; 3277 3278 if Is_Entity_Name (A) and then Is_Type (Entity (A)) then 3279 A_Type := Get_Full_View (Entity (A)); 3280 3281 if Valid_Ancestor_Type then 3282 Set_Entity (A, A_Type); 3283 Set_Etype (A, A_Type); 3284 3285 Validate_Ancestor_Part (N); 3286 Resolve_Record_Aggregate (N, Typ); 3287 end if; 3288 3289 elsif Nkind (A) /= N_Aggregate then 3290 if Is_Overloaded (A) then 3291 A_Type := Any_Type; 3292 3293 Get_First_Interp (A, I, It); 3294 while Present (It.Typ) loop 3295 3296 -- Consider limited interpretations if Ada 2005 or higher 3297 3298 if Is_Tagged_Type (It.Typ) 3299 and then (Ada_Version >= Ada_2005 3300 or else not Is_Limited_Type (It.Typ)) 3301 then 3302 if A_Type /= Any_Type then 3303 Error_Msg_N ("cannot resolve expression", A); 3304 return; 3305 else 3306 A_Type := It.Typ; 3307 end if; 3308 end if; 3309 3310 Get_Next_Interp (I, It); 3311 end loop; 3312 3313 if A_Type = Any_Type then 3314 if Ada_Version >= Ada_2005 then 3315 Error_Msg_N 3316 ("ancestor part must be of a tagged type", A); 3317 else 3318 Error_Msg_N 3319 ("ancestor part must be of a nonlimited tagged type", A); 3320 end if; 3321 3322 return; 3323 end if; 3324 3325 else 3326 A_Type := Etype (A); 3327 end if; 3328 3329 if Valid_Ancestor_Type then 3330 Resolve (A, A_Type); 3331 Check_Unset_Reference (A); 3332 Check_Non_Static_Context (A); 3333 3334 -- The aggregate is illegal if the ancestor expression is a call 3335 -- to a function with a limited unconstrained result, unless the 3336 -- type of the aggregate is a null extension. This restriction 3337 -- was added in AI05-67 to simplify implementation. 3338 3339 if Nkind (A) = N_Function_Call 3340 and then Is_Limited_Type (A_Type) 3341 and then not Is_Null_Extension (Typ) 3342 and then not Is_Constrained (A_Type) 3343 then 3344 Error_Msg_N 3345 ("type of limited ancestor part must be constrained", A); 3346 3347 -- Reject the use of CPP constructors that leave objects partially 3348 -- initialized. For example: 3349 3350 -- type CPP_Root is tagged limited record ... 3351 -- pragma Import (CPP, CPP_Root); 3352 3353 -- type CPP_DT is new CPP_Root and Iface ... 3354 -- pragma Import (CPP, CPP_DT); 3355 3356 -- type Ada_DT is new CPP_DT with ... 3357 3358 -- Obj : Ada_DT := Ada_DT'(New_CPP_Root with others => <>); 3359 3360 -- Using the constructor of CPP_Root the slots of the dispatch 3361 -- table of CPP_DT cannot be set, and the secondary tag of 3362 -- CPP_DT is unknown. 3363 3364 elsif Nkind (A) = N_Function_Call 3365 and then Is_CPP_Constructor_Call (A) 3366 and then Enclosing_CPP_Parent (Typ) /= A_Type 3367 then 3368 Error_Msg_NE 3369 ("??must use 'C'P'P constructor for type &", A, 3370 Enclosing_CPP_Parent (Typ)); 3371 3372 -- The following call is not needed if the previous warning 3373 -- is promoted to an error. 3374 3375 Resolve_Record_Aggregate (N, Typ); 3376 3377 elsif Is_Class_Wide_Type (Etype (A)) 3378 and then Nkind (Original_Node (A)) = N_Function_Call 3379 then 3380 -- If the ancestor part is a dispatching call, it appears 3381 -- statically to be a legal ancestor, but it yields any member 3382 -- of the class, and it is not possible to determine whether 3383 -- it is an ancestor of the extension aggregate (much less 3384 -- which ancestor). It is not possible to determine the 3385 -- components of the extension part. 3386 3387 -- This check implements AI-306, which in fact was motivated by 3388 -- an AdaCore query to the ARG after this test was added. 3389 3390 Error_Msg_N ("ancestor part must be statically tagged", A); 3391 else 3392 -- We are using the build-in-place protocol, but we can't build 3393 -- in place, because we need to call the function before 3394 -- allocating the aggregate. Could do better for null 3395 -- extensions, and maybe for nondiscriminated types. 3396 -- This is wrong for limited, but those were wrong already. 3397 3398 if not Is_Limited_View (A_Type) 3399 and then Is_Build_In_Place_Function_Call (A) 3400 then 3401 Transform_BIP_Assignment (A_Type); 3402 end if; 3403 3404 Resolve_Record_Aggregate (N, Typ); 3405 end if; 3406 end if; 3407 3408 else 3409 Error_Msg_N ("no unique type for this aggregate", A); 3410 end if; 3411 3412 Check_Function_Writable_Actuals (N); 3413 end Resolve_Extension_Aggregate; 3414 3415 ------------------------------ 3416 -- Resolve_Record_Aggregate -- 3417 ------------------------------ 3418 3419 procedure Resolve_Record_Aggregate (N : Node_Id; Typ : Entity_Id) is 3420 New_Assoc_List : constant List_Id := New_List; 3421 -- New_Assoc_List is the newly built list of N_Component_Association 3422 -- nodes. 3423 3424 Others_Etype : Entity_Id := Empty; 3425 -- This variable is used to save the Etype of the last record component 3426 -- that takes its value from the others choice. Its purpose is: 3427 -- 3428 -- (a) make sure the others choice is useful 3429 -- 3430 -- (b) make sure the type of all the components whose value is 3431 -- subsumed by the others choice are the same. 3432 -- 3433 -- This variable is updated as a side effect of function Get_Value. 3434 3435 Box_Node : Node_Id := Empty; 3436 Is_Box_Present : Boolean := False; 3437 Others_Box : Integer := 0; 3438 -- Ada 2005 (AI-287): Variables used in case of default initialization 3439 -- to provide a functionality similar to Others_Etype. Box_Present 3440 -- indicates that the component takes its default initialization; 3441 -- Others_Box counts the number of components of the current aggregate 3442 -- (which may be a sub-aggregate of a larger one) that are default- 3443 -- initialized. A value of One indicates that an others_box is present. 3444 -- Any larger value indicates that the others_box is not redundant. 3445 -- These variables, similar to Others_Etype, are also updated as a side 3446 -- effect of function Get_Value. Box_Node is used to place a warning on 3447 -- a redundant others_box. 3448 3449 procedure Add_Association 3450 (Component : Entity_Id; 3451 Expr : Node_Id; 3452 Assoc_List : List_Id; 3453 Is_Box_Present : Boolean := False); 3454 -- Builds a new N_Component_Association node which associates Component 3455 -- to expression Expr and adds it to the association list being built, 3456 -- either New_Assoc_List, or the association being built for an inner 3457 -- aggregate. 3458 3459 procedure Add_Discriminant_Values 3460 (New_Aggr : Node_Id; 3461 Assoc_List : List_Id); 3462 -- The constraint to a component may be given by a discriminant of the 3463 -- enclosing type, in which case we have to retrieve its value, which is 3464 -- part of the enclosing aggregate. Assoc_List provides the discriminant 3465 -- associations of the current type or of some enclosing record. 3466 3467 function Discriminant_Present (Input_Discr : Entity_Id) return Boolean; 3468 -- If aggregate N is a regular aggregate this routine will return True. 3469 -- Otherwise, if N is an extension aggregate, then Input_Discr denotes 3470 -- a discriminant whose value may already have been specified by N's 3471 -- ancestor part. This routine checks whether this is indeed the case 3472 -- and if so returns False, signaling that no value for Input_Discr 3473 -- should appear in N's aggregate part. Also, in this case, the routine 3474 -- appends to New_Assoc_List the discriminant value specified in the 3475 -- ancestor part. 3476 -- 3477 -- If the aggregate is in a context with expansion delayed, it will be 3478 -- reanalyzed. The inherited discriminant values must not be reinserted 3479 -- in the component list to prevent spurious errors, but they must be 3480 -- present on first analysis to build the proper subtype indications. 3481 -- The flag Inherited_Discriminant is used to prevent the re-insertion. 3482 3483 function Find_Private_Ancestor (Typ : Entity_Id) return Entity_Id; 3484 -- AI05-0115: Find earlier ancestor in the derivation chain that is 3485 -- derived from private view Typ. Whether the aggregate is legal depends 3486 -- on the current visibility of the type as well as that of the parent 3487 -- of the ancestor. 3488 3489 function Get_Value 3490 (Compon : Node_Id; 3491 From : List_Id; 3492 Consider_Others_Choice : Boolean := False) return Node_Id; 3493 -- Given a record component stored in parameter Compon, this function 3494 -- returns its value as it appears in the list From, which is a list 3495 -- of N_Component_Association nodes. 3496 -- 3497 -- If no component association has a choice for the searched component, 3498 -- the value provided by the others choice is returned, if there is one, 3499 -- and Consider_Others_Choice is set to true. Otherwise Empty is 3500 -- returned. If there is more than one component association giving a 3501 -- value for the searched record component, an error message is emitted 3502 -- and the first found value is returned. 3503 -- 3504 -- If Consider_Others_Choice is set and the returned expression comes 3505 -- from the others choice, then Others_Etype is set as a side effect. 3506 -- An error message is emitted if the components taking their value from 3507 -- the others choice do not have same type. 3508 3509 procedure Propagate_Discriminants 3510 (Aggr : Node_Id; 3511 Assoc_List : List_Id); 3512 -- Nested components may themselves be discriminated types constrained 3513 -- by outer discriminants, whose values must be captured before the 3514 -- aggregate is expanded into assignments. 3515 3516 procedure Resolve_Aggr_Expr (Expr : Node_Id; Component : Entity_Id); 3517 -- Analyzes and resolves expression Expr against the Etype of the 3518 -- Component. This routine also applies all appropriate checks to Expr. 3519 -- It finally saves a Expr in the newly created association list that 3520 -- will be attached to the final record aggregate. Note that if the 3521 -- Parent pointer of Expr is not set then Expr was produced with a 3522 -- New_Copy_Tree or some such. 3523 3524 procedure Rewrite_Range (Root_Type : Entity_Id; Rge : Node_Id); 3525 -- Rewrite a range node Rge when its bounds refer to non-stored 3526 -- discriminants from Root_Type, to replace them with the stored 3527 -- discriminant values. This is required in GNATprove mode, and is 3528 -- adopted in all modes to avoid special-casing GNATprove mode. 3529 3530 --------------------- 3531 -- Add_Association -- 3532 --------------------- 3533 3534 procedure Add_Association 3535 (Component : Entity_Id; 3536 Expr : Node_Id; 3537 Assoc_List : List_Id; 3538 Is_Box_Present : Boolean := False) 3539 is 3540 Choice_List : constant List_Id := New_List; 3541 Loc : Source_Ptr; 3542 3543 begin 3544 -- If this is a box association the expression is missing, so use the 3545 -- Sloc of the aggregate itself for the new association. 3546 3547 if Present (Expr) then 3548 Loc := Sloc (Expr); 3549 else 3550 Loc := Sloc (N); 3551 end if; 3552 3553 Append_To (Choice_List, New_Occurrence_Of (Component, Loc)); 3554 3555 Append_To (Assoc_List, 3556 Make_Component_Association (Loc, 3557 Choices => Choice_List, 3558 Expression => Expr, 3559 Box_Present => Is_Box_Present)); 3560 end Add_Association; 3561 3562 ----------------------------- 3563 -- Add_Discriminant_Values -- 3564 ----------------------------- 3565 3566 procedure Add_Discriminant_Values 3567 (New_Aggr : Node_Id; 3568 Assoc_List : List_Id) 3569 is 3570 Assoc : Node_Id; 3571 Discr : Entity_Id; 3572 Discr_Elmt : Elmt_Id; 3573 Discr_Val : Node_Id; 3574 Val : Entity_Id; 3575 3576 begin 3577 Discr := First_Discriminant (Etype (New_Aggr)); 3578 Discr_Elmt := First_Elmt (Discriminant_Constraint (Etype (New_Aggr))); 3579 while Present (Discr_Elmt) loop 3580 Discr_Val := Node (Discr_Elmt); 3581 3582 -- If the constraint is given by a discriminant then it is a 3583 -- discriminant of an enclosing record, and its value has already 3584 -- been placed in the association list. 3585 3586 if Is_Entity_Name (Discr_Val) 3587 and then Ekind (Entity (Discr_Val)) = E_Discriminant 3588 then 3589 Val := Entity (Discr_Val); 3590 3591 Assoc := First (Assoc_List); 3592 while Present (Assoc) loop 3593 if Present (Entity (First (Choices (Assoc)))) 3594 and then Entity (First (Choices (Assoc))) = Val 3595 then 3596 Discr_Val := Expression (Assoc); 3597 exit; 3598 end if; 3599 3600 Next (Assoc); 3601 end loop; 3602 end if; 3603 3604 Add_Association 3605 (Discr, New_Copy_Tree (Discr_Val), 3606 Component_Associations (New_Aggr)); 3607 3608 -- If the discriminant constraint is a current instance, mark the 3609 -- current aggregate so that the self-reference can be expanded 3610 -- later. The constraint may refer to the subtype of aggregate, so 3611 -- use base type for comparison. 3612 3613 if Nkind (Discr_Val) = N_Attribute_Reference 3614 and then Is_Entity_Name (Prefix (Discr_Val)) 3615 and then Is_Type (Entity (Prefix (Discr_Val))) 3616 and then Base_Type (Etype (N)) = Entity (Prefix (Discr_Val)) 3617 then 3618 Set_Has_Self_Reference (N); 3619 end if; 3620 3621 Next_Elmt (Discr_Elmt); 3622 Next_Discriminant (Discr); 3623 end loop; 3624 end Add_Discriminant_Values; 3625 3626 -------------------------- 3627 -- Discriminant_Present -- 3628 -------------------------- 3629 3630 function Discriminant_Present (Input_Discr : Entity_Id) return Boolean is 3631 Regular_Aggr : constant Boolean := Nkind (N) /= N_Extension_Aggregate; 3632 3633 Ancestor_Is_Subtyp : Boolean; 3634 3635 Loc : Source_Ptr; 3636 3637 Ancestor : Node_Id; 3638 Ancestor_Typ : Entity_Id; 3639 Comp_Assoc : Node_Id; 3640 Discr : Entity_Id; 3641 Discr_Expr : Node_Id; 3642 Discr_Val : Elmt_Id := No_Elmt; 3643 Orig_Discr : Entity_Id; 3644 3645 begin 3646 if Regular_Aggr then 3647 return True; 3648 end if; 3649 3650 -- Check whether inherited discriminant values have already been 3651 -- inserted in the aggregate. This will be the case if we are 3652 -- re-analyzing an aggregate whose expansion was delayed. 3653 3654 if Present (Component_Associations (N)) then 3655 Comp_Assoc := First (Component_Associations (N)); 3656 while Present (Comp_Assoc) loop 3657 if Inherited_Discriminant (Comp_Assoc) then 3658 return True; 3659 end if; 3660 3661 Next (Comp_Assoc); 3662 end loop; 3663 end if; 3664 3665 Ancestor := Ancestor_Part (N); 3666 Ancestor_Typ := Etype (Ancestor); 3667 Loc := Sloc (Ancestor); 3668 3669 -- For a private type with unknown discriminants, use the underlying 3670 -- record view if it is available. 3671 3672 if Has_Unknown_Discriminants (Ancestor_Typ) 3673 and then Present (Full_View (Ancestor_Typ)) 3674 and then Present (Underlying_Record_View (Full_View (Ancestor_Typ))) 3675 then 3676 Ancestor_Typ := Underlying_Record_View (Full_View (Ancestor_Typ)); 3677 end if; 3678 3679 Ancestor_Is_Subtyp := 3680 Is_Entity_Name (Ancestor) and then Is_Type (Entity (Ancestor)); 3681 3682 -- If the ancestor part has no discriminants clearly N's aggregate 3683 -- part must provide a value for Discr. 3684 3685 if not Has_Discriminants (Ancestor_Typ) then 3686 return True; 3687 3688 -- If the ancestor part is an unconstrained subtype mark then the 3689 -- Discr must be present in N's aggregate part. 3690 3691 elsif Ancestor_Is_Subtyp 3692 and then not Is_Constrained (Entity (Ancestor)) 3693 then 3694 return True; 3695 end if; 3696 3697 -- Now look to see if Discr was specified in the ancestor part 3698 3699 if Ancestor_Is_Subtyp then 3700 Discr_Val := 3701 First_Elmt (Discriminant_Constraint (Entity (Ancestor))); 3702 end if; 3703 3704 Orig_Discr := Original_Record_Component (Input_Discr); 3705 3706 Discr := First_Discriminant (Ancestor_Typ); 3707 while Present (Discr) loop 3708 3709 -- If Ancestor has already specified Disc value then insert its 3710 -- value in the final aggregate. 3711 3712 if Original_Record_Component (Discr) = Orig_Discr then 3713 if Ancestor_Is_Subtyp then 3714 Discr_Expr := New_Copy_Tree (Node (Discr_Val)); 3715 else 3716 Discr_Expr := 3717 Make_Selected_Component (Loc, 3718 Prefix => Duplicate_Subexpr (Ancestor), 3719 Selector_Name => New_Occurrence_Of (Input_Discr, Loc)); 3720 end if; 3721 3722 Resolve_Aggr_Expr (Discr_Expr, Input_Discr); 3723 Set_Inherited_Discriminant (Last (New_Assoc_List)); 3724 return False; 3725 end if; 3726 3727 Next_Discriminant (Discr); 3728 3729 if Ancestor_Is_Subtyp then 3730 Next_Elmt (Discr_Val); 3731 end if; 3732 end loop; 3733 3734 return True; 3735 end Discriminant_Present; 3736 3737 --------------------------- 3738 -- Find_Private_Ancestor -- 3739 --------------------------- 3740 3741 function Find_Private_Ancestor (Typ : Entity_Id) return Entity_Id is 3742 Par : Entity_Id; 3743 3744 begin 3745 Par := Typ; 3746 loop 3747 if Has_Private_Ancestor (Par) 3748 and then not Has_Private_Ancestor (Etype (Base_Type (Par))) 3749 then 3750 return Par; 3751 3752 elsif not Is_Derived_Type (Par) then 3753 return Empty; 3754 3755 else 3756 Par := Etype (Base_Type (Par)); 3757 end if; 3758 end loop; 3759 end Find_Private_Ancestor; 3760 3761 --------------- 3762 -- Get_Value -- 3763 --------------- 3764 3765 function Get_Value 3766 (Compon : Node_Id; 3767 From : List_Id; 3768 Consider_Others_Choice : Boolean := False) return Node_Id 3769 is 3770 Typ : constant Entity_Id := Etype (Compon); 3771 Assoc : Node_Id; 3772 Expr : Node_Id := Empty; 3773 Selector_Name : Node_Id; 3774 3775 begin 3776 Is_Box_Present := False; 3777 3778 if No (From) then 3779 return Empty; 3780 end if; 3781 3782 Assoc := First (From); 3783 while Present (Assoc) loop 3784 Selector_Name := First (Choices (Assoc)); 3785 while Present (Selector_Name) loop 3786 if Nkind (Selector_Name) = N_Others_Choice then 3787 if Consider_Others_Choice and then No (Expr) then 3788 3789 -- We need to duplicate the expression for each 3790 -- successive component covered by the others choice. 3791 -- This is redundant if the others_choice covers only 3792 -- one component (small optimization possible???), but 3793 -- indispensable otherwise, because each one must be 3794 -- expanded individually to preserve side effects. 3795 3796 -- Ada 2005 (AI-287): In case of default initialization 3797 -- of components, we duplicate the corresponding default 3798 -- expression (from the record type declaration). The 3799 -- copy must carry the sloc of the association (not the 3800 -- original expression) to prevent spurious elaboration 3801 -- checks when the default includes function calls. 3802 3803 if Box_Present (Assoc) then 3804 Others_Box := Others_Box + 1; 3805 Is_Box_Present := True; 3806 3807 if Expander_Active then 3808 return 3809 New_Copy_Tree_And_Copy_Dimensions 3810 (Expression (Parent (Compon)), 3811 New_Sloc => Sloc (Assoc)); 3812 else 3813 return Expression (Parent (Compon)); 3814 end if; 3815 3816 else 3817 if Present (Others_Etype) 3818 and then Base_Type (Others_Etype) /= Base_Type (Typ) 3819 then 3820 -- If the components are of an anonymous access 3821 -- type they are distinct, but this is legal in 3822 -- Ada 2012 as long as designated types match. 3823 3824 if (Ekind (Typ) = E_Anonymous_Access_Type 3825 or else Ekind (Typ) = 3826 E_Anonymous_Access_Subprogram_Type) 3827 and then Designated_Type (Typ) = 3828 Designated_Type (Others_Etype) 3829 then 3830 null; 3831 else 3832 Error_Msg_N 3833 ("components in OTHERS choice must have same " 3834 & "type", Selector_Name); 3835 end if; 3836 end if; 3837 3838 Others_Etype := Typ; 3839 3840 -- Copy the expression so that it is resolved 3841 -- independently for each component, This is needed 3842 -- for accessibility checks on compoents of anonymous 3843 -- access types, even in compile_only mode. 3844 3845 if not Inside_A_Generic then 3846 3847 -- In ASIS mode, preanalyze the expression in an 3848 -- others association before making copies for 3849 -- separate resolution and accessibility checks. 3850 -- This ensures that the type of the expression is 3851 -- available to ASIS in all cases, in particular if 3852 -- the expression is itself an aggregate. 3853 3854 if ASIS_Mode then 3855 Preanalyze_And_Resolve (Expression (Assoc), Typ); 3856 end if; 3857 3858 return 3859 New_Copy_Tree_And_Copy_Dimensions 3860 (Expression (Assoc)); 3861 3862 else 3863 return Expression (Assoc); 3864 end if; 3865 end if; 3866 end if; 3867 3868 elsif Chars (Compon) = Chars (Selector_Name) then 3869 if No (Expr) then 3870 3871 -- Ada 2005 (AI-231) 3872 3873 if Ada_Version >= Ada_2005 3874 and then Known_Null (Expression (Assoc)) 3875 then 3876 Check_Can_Never_Be_Null (Compon, Expression (Assoc)); 3877 end if; 3878 3879 -- We need to duplicate the expression when several 3880 -- components are grouped together with a "|" choice. 3881 -- For instance "filed1 | filed2 => Expr" 3882 3883 -- Ada 2005 (AI-287) 3884 3885 if Box_Present (Assoc) then 3886 Is_Box_Present := True; 3887 3888 -- Duplicate the default expression of the component 3889 -- from the record type declaration, so a new copy 3890 -- can be attached to the association. 3891 3892 -- Note that we always copy the default expression, 3893 -- even when the association has a single choice, in 3894 -- order to create a proper association for the 3895 -- expanded aggregate. 3896 3897 -- Component may have no default, in which case the 3898 -- expression is empty and the component is default- 3899 -- initialized, but an association for the component 3900 -- exists, and it is not covered by an others clause. 3901 3902 -- Scalar and private types have no initialization 3903 -- procedure, so they remain uninitialized. If the 3904 -- target of the aggregate is a constant this 3905 -- deserves a warning. 3906 3907 if No (Expression (Parent (Compon))) 3908 and then not Has_Non_Null_Base_Init_Proc (Typ) 3909 and then not Has_Aspect (Typ, Aspect_Default_Value) 3910 and then not Is_Concurrent_Type (Typ) 3911 and then Nkind (Parent (N)) = N_Object_Declaration 3912 and then Constant_Present (Parent (N)) 3913 then 3914 Error_Msg_Node_2 := Typ; 3915 Error_Msg_NE 3916 ("component&? of type& is uninitialized", 3917 Assoc, Selector_Name); 3918 3919 -- An additional reminder if the component type 3920 -- is a generic formal. 3921 3922 if Is_Generic_Type (Base_Type (Typ)) then 3923 Error_Msg_NE 3924 ("\instance should provide actual type with " 3925 & "initialization for&", Assoc, Typ); 3926 end if; 3927 end if; 3928 3929 return 3930 New_Copy_Tree_And_Copy_Dimensions 3931 (Expression (Parent (Compon))); 3932 3933 else 3934 if Present (Next (Selector_Name)) then 3935 Expr := New_Copy_Tree_And_Copy_Dimensions 3936 (Expression (Assoc)); 3937 else 3938 Expr := Expression (Assoc); 3939 end if; 3940 end if; 3941 3942 Generate_Reference (Compon, Selector_Name, 'm'); 3943 3944 else 3945 Error_Msg_NE 3946 ("more than one value supplied for &", 3947 Selector_Name, Compon); 3948 3949 end if; 3950 end if; 3951 3952 Next (Selector_Name); 3953 end loop; 3954 3955 Next (Assoc); 3956 end loop; 3957 3958 return Expr; 3959 end Get_Value; 3960 3961 ----------------------------- 3962 -- Propagate_Discriminants -- 3963 ----------------------------- 3964 3965 procedure Propagate_Discriminants 3966 (Aggr : Node_Id; 3967 Assoc_List : List_Id) 3968 is 3969 Loc : constant Source_Ptr := Sloc (N); 3970 3971 Needs_Box : Boolean := False; 3972 3973 procedure Process_Component (Comp : Entity_Id); 3974 -- Add one component with a box association to the inner aggregate, 3975 -- and recurse if component is itself composite. 3976 3977 ----------------------- 3978 -- Process_Component -- 3979 ----------------------- 3980 3981 procedure Process_Component (Comp : Entity_Id) is 3982 T : constant Entity_Id := Etype (Comp); 3983 New_Aggr : Node_Id; 3984 3985 begin 3986 if Is_Record_Type (T) and then Has_Discriminants (T) then 3987 New_Aggr := Make_Aggregate (Loc, New_List, New_List); 3988 Set_Etype (New_Aggr, T); 3989 3990 Add_Association 3991 (Comp, New_Aggr, Component_Associations (Aggr)); 3992 3993 -- Collect discriminant values and recurse 3994 3995 Add_Discriminant_Values (New_Aggr, Assoc_List); 3996 Propagate_Discriminants (New_Aggr, Assoc_List); 3997 3998 else 3999 Needs_Box := True; 4000 end if; 4001 end Process_Component; 4002 4003 -- Local variables 4004 4005 Aggr_Type : constant Entity_Id := Base_Type (Etype (Aggr)); 4006 Components : constant Elist_Id := New_Elmt_List; 4007 Def_Node : constant Node_Id := 4008 Type_Definition (Declaration_Node (Aggr_Type)); 4009 4010 Comp : Node_Id; 4011 Comp_Elmt : Elmt_Id; 4012 Errors : Boolean; 4013 4014 -- Start of processing for Propagate_Discriminants 4015 4016 begin 4017 -- The component type may be a variant type. Collect the components 4018 -- that are ruled by the known values of the discriminants. Their 4019 -- values have already been inserted into the component list of the 4020 -- current aggregate. 4021 4022 if Nkind (Def_Node) = N_Record_Definition 4023 and then Present (Component_List (Def_Node)) 4024 and then Present (Variant_Part (Component_List (Def_Node))) 4025 then 4026 Gather_Components (Aggr_Type, 4027 Component_List (Def_Node), 4028 Governed_By => Component_Associations (Aggr), 4029 Into => Components, 4030 Report_Errors => Errors); 4031 4032 Comp_Elmt := First_Elmt (Components); 4033 while Present (Comp_Elmt) loop 4034 if Ekind (Node (Comp_Elmt)) /= E_Discriminant then 4035 Process_Component (Node (Comp_Elmt)); 4036 end if; 4037 4038 Next_Elmt (Comp_Elmt); 4039 end loop; 4040 4041 -- No variant part, iterate over all components 4042 4043 else 4044 Comp := First_Component (Etype (Aggr)); 4045 while Present (Comp) loop 4046 Process_Component (Comp); 4047 Next_Component (Comp); 4048 end loop; 4049 end if; 4050 4051 if Needs_Box then 4052 Append_To (Component_Associations (Aggr), 4053 Make_Component_Association (Loc, 4054 Choices => New_List (Make_Others_Choice (Loc)), 4055 Expression => Empty, 4056 Box_Present => True)); 4057 end if; 4058 end Propagate_Discriminants; 4059 4060 ----------------------- 4061 -- Resolve_Aggr_Expr -- 4062 ----------------------- 4063 4064 procedure Resolve_Aggr_Expr (Expr : Node_Id; Component : Entity_Id) is 4065 function Has_Expansion_Delayed (Expr : Node_Id) return Boolean; 4066 -- If the expression is an aggregate (possibly qualified) then its 4067 -- expansion is delayed until the enclosing aggregate is expanded 4068 -- into assignments. In that case, do not generate checks on the 4069 -- expression, because they will be generated later, and will other- 4070 -- wise force a copy (to remove side effects) that would leave a 4071 -- dynamic-sized aggregate in the code, something that gigi cannot 4072 -- handle. 4073 4074 --------------------------- 4075 -- Has_Expansion_Delayed -- 4076 --------------------------- 4077 4078 function Has_Expansion_Delayed (Expr : Node_Id) return Boolean is 4079 begin 4080 return 4081 (Nkind_In (Expr, N_Aggregate, N_Extension_Aggregate) 4082 and then Present (Etype (Expr)) 4083 and then Is_Record_Type (Etype (Expr)) 4084 and then Expansion_Delayed (Expr)) 4085 or else 4086 (Nkind (Expr) = N_Qualified_Expression 4087 and then Has_Expansion_Delayed (Expression (Expr))); 4088 end Has_Expansion_Delayed; 4089 4090 -- Local variables 4091 4092 Expr_Type : Entity_Id := Empty; 4093 New_C : Entity_Id := Component; 4094 New_Expr : Node_Id; 4095 4096 Relocate : Boolean; 4097 -- Set to True if the resolved Expr node needs to be relocated when 4098 -- attached to the newly created association list. This node need not 4099 -- be relocated if its parent pointer is not set. In fact in this 4100 -- case Expr is the output of a New_Copy_Tree call. If Relocate is 4101 -- True then we have analyzed the expression node in the original 4102 -- aggregate and hence it needs to be relocated when moved over to 4103 -- the new association list. 4104 4105 -- Start of processing for Resolve_Aggr_Expr 4106 4107 begin 4108 -- If the type of the component is elementary or the type of the 4109 -- aggregate does not contain discriminants, use the type of the 4110 -- component to resolve Expr. 4111 4112 if Is_Elementary_Type (Etype (Component)) 4113 or else not Has_Discriminants (Etype (N)) 4114 then 4115 Expr_Type := Etype (Component); 4116 4117 -- Otherwise we have to pick up the new type of the component from 4118 -- the new constrained subtype of the aggregate. In fact components 4119 -- which are of a composite type might be constrained by a 4120 -- discriminant, and we want to resolve Expr against the subtype were 4121 -- all discriminant occurrences are replaced with their actual value. 4122 4123 else 4124 New_C := First_Component (Etype (N)); 4125 while Present (New_C) loop 4126 if Chars (New_C) = Chars (Component) then 4127 Expr_Type := Etype (New_C); 4128 exit; 4129 end if; 4130 4131 Next_Component (New_C); 4132 end loop; 4133 4134 pragma Assert (Present (Expr_Type)); 4135 4136 -- For each range in an array type where a discriminant has been 4137 -- replaced with the constraint, check that this range is within 4138 -- the range of the base type. This checks is done in the init 4139 -- proc for regular objects, but has to be done here for 4140 -- aggregates since no init proc is called for them. 4141 4142 if Is_Array_Type (Expr_Type) then 4143 declare 4144 Index : Node_Id; 4145 -- Range of the current constrained index in the array 4146 4147 Orig_Index : Node_Id := First_Index (Etype (Component)); 4148 -- Range corresponding to the range Index above in the 4149 -- original unconstrained record type. The bounds of this 4150 -- range may be governed by discriminants. 4151 4152 Unconstr_Index : Node_Id := First_Index (Etype (Expr_Type)); 4153 -- Range corresponding to the range Index above for the 4154 -- unconstrained array type. This range is needed to apply 4155 -- range checks. 4156 4157 begin 4158 Index := First_Index (Expr_Type); 4159 while Present (Index) loop 4160 if Depends_On_Discriminant (Orig_Index) then 4161 Apply_Range_Check (Index, Etype (Unconstr_Index)); 4162 end if; 4163 4164 Next_Index (Index); 4165 Next_Index (Orig_Index); 4166 Next_Index (Unconstr_Index); 4167 end loop; 4168 end; 4169 end if; 4170 end if; 4171 4172 -- If the Parent pointer of Expr is not set, Expr is an expression 4173 -- duplicated by New_Tree_Copy (this happens for record aggregates 4174 -- that look like (Field1 | Filed2 => Expr) or (others => Expr)). 4175 -- Such a duplicated expression must be attached to the tree 4176 -- before analysis and resolution to enforce the rule that a tree 4177 -- fragment should never be analyzed or resolved unless it is 4178 -- attached to the current compilation unit. 4179 4180 if No (Parent (Expr)) then 4181 Set_Parent (Expr, N); 4182 Relocate := False; 4183 else 4184 Relocate := True; 4185 end if; 4186 4187 Analyze_And_Resolve (Expr, Expr_Type); 4188 Check_Expr_OK_In_Limited_Aggregate (Expr); 4189 Check_Non_Static_Context (Expr); 4190 Check_Unset_Reference (Expr); 4191 4192 -- Check wrong use of class-wide types 4193 4194 if Is_Class_Wide_Type (Etype (Expr)) then 4195 Error_Msg_N ("dynamically tagged expression not allowed", Expr); 4196 end if; 4197 4198 if not Has_Expansion_Delayed (Expr) then 4199 Aggregate_Constraint_Checks (Expr, Expr_Type); 4200 end if; 4201 4202 -- If an aggregate component has a type with predicates, an explicit 4203 -- predicate check must be applied, as for an assignment statement, 4204 -- because the aggegate might not be expanded into individual 4205 -- component assignments. 4206 4207 if Has_Predicates (Expr_Type) 4208 and then Analyzed (Expr) 4209 then 4210 Apply_Predicate_Check (Expr, Expr_Type); 4211 end if; 4212 4213 if Raises_Constraint_Error (Expr) then 4214 Set_Raises_Constraint_Error (N); 4215 end if; 4216 4217 -- If the expression has been marked as requiring a range check, then 4218 -- generate it here. It's a bit odd to be generating such checks in 4219 -- the analyzer, but harmless since Generate_Range_Check does nothing 4220 -- (other than making sure Do_Range_Check is set) if the expander is 4221 -- not active. 4222 4223 if Do_Range_Check (Expr) then 4224 Generate_Range_Check (Expr, Expr_Type, CE_Range_Check_Failed); 4225 end if; 4226 4227 -- Add association Component => Expr if the caller requests it 4228 4229 if Relocate then 4230 New_Expr := Relocate_Node (Expr); 4231 4232 -- Since New_Expr is not gonna be analyzed later on, we need to 4233 -- propagate here the dimensions form Expr to New_Expr. 4234 4235 Copy_Dimensions (Expr, New_Expr); 4236 4237 else 4238 New_Expr := Expr; 4239 end if; 4240 4241 Add_Association (New_C, New_Expr, New_Assoc_List); 4242 end Resolve_Aggr_Expr; 4243 4244 ------------------- 4245 -- Rewrite_Range -- 4246 ------------------- 4247 4248 procedure Rewrite_Range (Root_Type : Entity_Id; Rge : Node_Id) is 4249 procedure Rewrite_Bound 4250 (Bound : Node_Id; 4251 Disc : Entity_Id; 4252 Expr_Disc : Node_Id); 4253 -- Rewrite a bound of the range Bound, when it is equal to the 4254 -- non-stored discriminant Disc, into the stored discriminant 4255 -- value Expr_Disc. 4256 4257 ------------------- 4258 -- Rewrite_Bound -- 4259 ------------------- 4260 4261 procedure Rewrite_Bound 4262 (Bound : Node_Id; 4263 Disc : Entity_Id; 4264 Expr_Disc : Node_Id) 4265 is 4266 begin 4267 if Nkind (Bound) = N_Identifier 4268 and then Entity (Bound) = Disc 4269 then 4270 Rewrite (Bound, New_Copy_Tree (Expr_Disc)); 4271 end if; 4272 end Rewrite_Bound; 4273 4274 -- Local variables 4275 4276 Low, High : Node_Id; 4277 Disc : Entity_Id; 4278 Expr_Disc : Elmt_Id; 4279 4280 -- Start of processing for Rewrite_Range 4281 4282 begin 4283 if Has_Discriminants (Root_Type) 4284 and then Nkind (Rge) = N_Range 4285 then 4286 Low := Low_Bound (Rge); 4287 High := High_Bound (Rge); 4288 4289 Disc := First_Discriminant (Root_Type); 4290 Expr_Disc := First_Elmt (Stored_Constraint (Etype (N))); 4291 while Present (Disc) loop 4292 Rewrite_Bound (Low, Disc, Node (Expr_Disc)); 4293 Rewrite_Bound (High, Disc, Node (Expr_Disc)); 4294 Next_Discriminant (Disc); 4295 Next_Elmt (Expr_Disc); 4296 end loop; 4297 end if; 4298 end Rewrite_Range; 4299 4300 -- Local variables 4301 4302 Components : constant Elist_Id := New_Elmt_List; 4303 -- Components is the list of the record components whose value must be 4304 -- provided in the aggregate. This list does include discriminants. 4305 4306 Component : Entity_Id; 4307 Component_Elmt : Elmt_Id; 4308 Expr : Node_Id; 4309 Positional_Expr : Node_Id; 4310 4311 -- Start of processing for Resolve_Record_Aggregate 4312 4313 begin 4314 -- A record aggregate is restricted in SPARK: 4315 4316 -- Each named association can have only a single choice. 4317 -- OTHERS cannot be used. 4318 -- Positional and named associations cannot be mixed. 4319 4320 if Present (Component_Associations (N)) 4321 and then Present (First (Component_Associations (N))) 4322 then 4323 if Present (Expressions (N)) then 4324 Check_SPARK_05_Restriction 4325 ("named association cannot follow positional one", 4326 First (Choices (First (Component_Associations (N))))); 4327 end if; 4328 4329 declare 4330 Assoc : Node_Id; 4331 4332 begin 4333 Assoc := First (Component_Associations (N)); 4334 while Present (Assoc) loop 4335 if Nkind (Assoc) = N_Iterated_Component_Association then 4336 Error_Msg_N 4337 ("iterated component association can only appear in an " 4338 & "array aggregate", N); 4339 raise Unrecoverable_Error; 4340 4341 else 4342 if List_Length (Choices (Assoc)) > 1 then 4343 Check_SPARK_05_Restriction 4344 ("component association in record aggregate must " 4345 & "contain a single choice", Assoc); 4346 end if; 4347 4348 if Nkind (First (Choices (Assoc))) = N_Others_Choice then 4349 Check_SPARK_05_Restriction 4350 ("record aggregate cannot contain OTHERS", Assoc); 4351 end if; 4352 end if; 4353 4354 Assoc := Next (Assoc); 4355 end loop; 4356 end; 4357 end if; 4358 4359 -- We may end up calling Duplicate_Subexpr on expressions that are 4360 -- attached to New_Assoc_List. For this reason we need to attach it 4361 -- to the tree by setting its parent pointer to N. This parent point 4362 -- will change in STEP 8 below. 4363 4364 Set_Parent (New_Assoc_List, N); 4365 4366 -- STEP 1: abstract type and null record verification 4367 4368 if Is_Abstract_Type (Typ) then 4369 Error_Msg_N ("type of aggregate cannot be abstract", N); 4370 end if; 4371 4372 if No (First_Entity (Typ)) and then Null_Record_Present (N) then 4373 Set_Etype (N, Typ); 4374 return; 4375 4376 elsif Present (First_Entity (Typ)) 4377 and then Null_Record_Present (N) 4378 and then not Is_Tagged_Type (Typ) 4379 then 4380 Error_Msg_N ("record aggregate cannot be null", N); 4381 return; 4382 4383 -- If the type has no components, then the aggregate should either 4384 -- have "null record", or in Ada 2005 it could instead have a single 4385 -- component association given by "others => <>". For Ada 95 we flag an 4386 -- error at this point, but for Ada 2005 we proceed with checking the 4387 -- associations below, which will catch the case where it's not an 4388 -- aggregate with "others => <>". Note that the legality of a <> 4389 -- aggregate for a null record type was established by AI05-016. 4390 4391 elsif No (First_Entity (Typ)) 4392 and then Ada_Version < Ada_2005 4393 then 4394 Error_Msg_N ("record aggregate must be null", N); 4395 return; 4396 end if; 4397 4398 -- STEP 2: Verify aggregate structure 4399 4400 Step_2 : declare 4401 Assoc : Node_Id; 4402 Bad_Aggregate : Boolean := False; 4403 Selector_Name : Node_Id; 4404 4405 begin 4406 if Present (Component_Associations (N)) then 4407 Assoc := First (Component_Associations (N)); 4408 else 4409 Assoc := Empty; 4410 end if; 4411 4412 while Present (Assoc) loop 4413 Selector_Name := First (Choices (Assoc)); 4414 while Present (Selector_Name) loop 4415 if Nkind (Selector_Name) = N_Identifier then 4416 null; 4417 4418 elsif Nkind (Selector_Name) = N_Others_Choice then 4419 if Selector_Name /= First (Choices (Assoc)) 4420 or else Present (Next (Selector_Name)) 4421 then 4422 Error_Msg_N 4423 ("OTHERS must appear alone in a choice list", 4424 Selector_Name); 4425 return; 4426 4427 elsif Present (Next (Assoc)) then 4428 Error_Msg_N 4429 ("OTHERS must appear last in an aggregate", 4430 Selector_Name); 4431 return; 4432 4433 -- (Ada 2005): If this is an association with a box, 4434 -- indicate that the association need not represent 4435 -- any component. 4436 4437 elsif Box_Present (Assoc) then 4438 Others_Box := 1; 4439 Box_Node := Assoc; 4440 end if; 4441 4442 else 4443 Error_Msg_N 4444 ("selector name should be identifier or OTHERS", 4445 Selector_Name); 4446 Bad_Aggregate := True; 4447 end if; 4448 4449 Next (Selector_Name); 4450 end loop; 4451 4452 Next (Assoc); 4453 end loop; 4454 4455 if Bad_Aggregate then 4456 return; 4457 end if; 4458 end Step_2; 4459 4460 -- STEP 3: Find discriminant Values 4461 4462 Step_3 : declare 4463 Discrim : Entity_Id; 4464 Missing_Discriminants : Boolean := False; 4465 4466 begin 4467 if Present (Expressions (N)) then 4468 Positional_Expr := First (Expressions (N)); 4469 else 4470 Positional_Expr := Empty; 4471 end if; 4472 4473 -- AI05-0115: if the ancestor part is a subtype mark, the ancestor 4474 -- must not have unknown discriminants. 4475 4476 if Is_Derived_Type (Typ) 4477 and then Has_Unknown_Discriminants (Root_Type (Typ)) 4478 and then Nkind (N) /= N_Extension_Aggregate 4479 then 4480 Error_Msg_NE 4481 ("aggregate not available for type& whose ancestor " 4482 & "has unknown discriminants ", N, Typ); 4483 end if; 4484 4485 if Has_Unknown_Discriminants (Typ) 4486 and then Present (Underlying_Record_View (Typ)) 4487 then 4488 Discrim := First_Discriminant (Underlying_Record_View (Typ)); 4489 elsif Has_Discriminants (Typ) then 4490 Discrim := First_Discriminant (Typ); 4491 else 4492 Discrim := Empty; 4493 end if; 4494 4495 -- First find the discriminant values in the positional components 4496 4497 while Present (Discrim) and then Present (Positional_Expr) loop 4498 if Discriminant_Present (Discrim) then 4499 Resolve_Aggr_Expr (Positional_Expr, Discrim); 4500 4501 -- Ada 2005 (AI-231) 4502 4503 if Ada_Version >= Ada_2005 4504 and then Known_Null (Positional_Expr) 4505 then 4506 Check_Can_Never_Be_Null (Discrim, Positional_Expr); 4507 end if; 4508 4509 Next (Positional_Expr); 4510 end if; 4511 4512 if Present (Get_Value (Discrim, Component_Associations (N))) then 4513 Error_Msg_NE 4514 ("more than one value supplied for discriminant&", 4515 N, Discrim); 4516 end if; 4517 4518 Next_Discriminant (Discrim); 4519 end loop; 4520 4521 -- Find remaining discriminant values if any among named components 4522 4523 while Present (Discrim) loop 4524 Expr := Get_Value (Discrim, Component_Associations (N), True); 4525 4526 if not Discriminant_Present (Discrim) then 4527 if Present (Expr) then 4528 Error_Msg_NE 4529 ("more than one value supplied for discriminant &", 4530 N, Discrim); 4531 end if; 4532 4533 elsif No (Expr) then 4534 Error_Msg_NE 4535 ("no value supplied for discriminant &", N, Discrim); 4536 Missing_Discriminants := True; 4537 4538 else 4539 Resolve_Aggr_Expr (Expr, Discrim); 4540 end if; 4541 4542 Next_Discriminant (Discrim); 4543 end loop; 4544 4545 if Missing_Discriminants then 4546 return; 4547 end if; 4548 4549 -- At this point and until the beginning of STEP 6, New_Assoc_List 4550 -- contains only the discriminants and their values. 4551 4552 end Step_3; 4553 4554 -- STEP 4: Set the Etype of the record aggregate 4555 4556 -- ??? This code is pretty much a copy of Sem_Ch3.Build_Subtype. That 4557 -- routine should really be exported in sem_util or some such and used 4558 -- in sem_ch3 and here rather than have a copy of the code which is a 4559 -- maintenance nightmare. 4560 4561 -- ??? Performance WARNING. The current implementation creates a new 4562 -- itype for all aggregates whose base type is discriminated. This means 4563 -- that for record aggregates nested inside an array aggregate we will 4564 -- create a new itype for each record aggregate if the array component 4565 -- type has discriminants. For large aggregates this may be a problem. 4566 -- What should be done in this case is to reuse itypes as much as 4567 -- possible. 4568 4569 if Has_Discriminants (Typ) 4570 or else (Has_Unknown_Discriminants (Typ) 4571 and then Present (Underlying_Record_View (Typ))) 4572 then 4573 Build_Constrained_Itype : declare 4574 Constrs : constant List_Id := New_List; 4575 Loc : constant Source_Ptr := Sloc (N); 4576 Def_Id : Entity_Id; 4577 Indic : Node_Id; 4578 New_Assoc : Node_Id; 4579 Subtyp_Decl : Node_Id; 4580 4581 begin 4582 New_Assoc := First (New_Assoc_List); 4583 while Present (New_Assoc) loop 4584 Append_To (Constrs, Duplicate_Subexpr (Expression (New_Assoc))); 4585 Next (New_Assoc); 4586 end loop; 4587 4588 if Has_Unknown_Discriminants (Typ) 4589 and then Present (Underlying_Record_View (Typ)) 4590 then 4591 Indic := 4592 Make_Subtype_Indication (Loc, 4593 Subtype_Mark => 4594 New_Occurrence_Of (Underlying_Record_View (Typ), Loc), 4595 Constraint => 4596 Make_Index_Or_Discriminant_Constraint (Loc, 4597 Constraints => Constrs)); 4598 else 4599 Indic := 4600 Make_Subtype_Indication (Loc, 4601 Subtype_Mark => 4602 New_Occurrence_Of (Base_Type (Typ), Loc), 4603 Constraint => 4604 Make_Index_Or_Discriminant_Constraint (Loc, 4605 Constraints => Constrs)); 4606 end if; 4607 4608 Def_Id := Create_Itype (Ekind (Typ), N); 4609 4610 Subtyp_Decl := 4611 Make_Subtype_Declaration (Loc, 4612 Defining_Identifier => Def_Id, 4613 Subtype_Indication => Indic); 4614 Set_Parent (Subtyp_Decl, Parent (N)); 4615 4616 -- Itypes must be analyzed with checks off (see itypes.ads) 4617 4618 Analyze (Subtyp_Decl, Suppress => All_Checks); 4619 4620 Set_Etype (N, Def_Id); 4621 Check_Static_Discriminated_Subtype 4622 (Def_Id, Expression (First (New_Assoc_List))); 4623 end Build_Constrained_Itype; 4624 4625 else 4626 Set_Etype (N, Typ); 4627 end if; 4628 4629 -- STEP 5: Get remaining components according to discriminant values 4630 4631 Step_5 : declare 4632 Dnode : Node_Id; 4633 Errors_Found : Boolean := False; 4634 Record_Def : Node_Id; 4635 Parent_Typ : Entity_Id; 4636 Parent_Typ_List : Elist_Id; 4637 Parent_Elmt : Elmt_Id; 4638 Root_Typ : Entity_Id; 4639 4640 begin 4641 if Is_Derived_Type (Typ) and then Is_Tagged_Type (Typ) then 4642 Parent_Typ_List := New_Elmt_List; 4643 4644 -- If this is an extension aggregate, the component list must 4645 -- include all components that are not in the given ancestor type. 4646 -- Otherwise, the component list must include components of all 4647 -- ancestors, starting with the root. 4648 4649 if Nkind (N) = N_Extension_Aggregate then 4650 Root_Typ := Base_Type (Etype (Ancestor_Part (N))); 4651 4652 else 4653 -- AI05-0115: check legality of aggregate for type with a 4654 -- private ancestor. 4655 4656 Root_Typ := Root_Type (Typ); 4657 if Has_Private_Ancestor (Typ) then 4658 declare 4659 Ancestor : constant Entity_Id := 4660 Find_Private_Ancestor (Typ); 4661 Ancestor_Unit : constant Entity_Id := 4662 Cunit_Entity 4663 (Get_Source_Unit (Ancestor)); 4664 Parent_Unit : constant Entity_Id := 4665 Cunit_Entity (Get_Source_Unit 4666 (Base_Type (Etype (Ancestor)))); 4667 begin 4668 -- Check whether we are in a scope that has full view 4669 -- over the private ancestor and its parent. This can 4670 -- only happen if the derivation takes place in a child 4671 -- unit of the unit that declares the parent, and we are 4672 -- in the private part or body of that child unit, else 4673 -- the aggregate is illegal. 4674 4675 if Is_Child_Unit (Ancestor_Unit) 4676 and then Scope (Ancestor_Unit) = Parent_Unit 4677 and then In_Open_Scopes (Scope (Ancestor)) 4678 and then 4679 (In_Private_Part (Scope (Ancestor)) 4680 or else In_Package_Body (Scope (Ancestor))) 4681 then 4682 null; 4683 4684 else 4685 Error_Msg_NE 4686 ("type of aggregate has private ancestor&!", 4687 N, Root_Typ); 4688 Error_Msg_N ("must use extension aggregate!", N); 4689 return; 4690 end if; 4691 end; 4692 end if; 4693 4694 Dnode := Declaration_Node (Base_Type (Root_Typ)); 4695 4696 -- If we don't get a full declaration, then we have some error 4697 -- which will get signalled later so skip this part. Otherwise 4698 -- gather components of root that apply to the aggregate type. 4699 -- We use the base type in case there is an applicable stored 4700 -- constraint that renames the discriminants of the root. 4701 4702 if Nkind (Dnode) = N_Full_Type_Declaration then 4703 Record_Def := Type_Definition (Dnode); 4704 Gather_Components 4705 (Base_Type (Typ), 4706 Component_List (Record_Def), 4707 Governed_By => New_Assoc_List, 4708 Into => Components, 4709 Report_Errors => Errors_Found); 4710 4711 if Errors_Found then 4712 Error_Msg_N 4713 ("discriminant controlling variant part is not static", 4714 N); 4715 return; 4716 end if; 4717 end if; 4718 end if; 4719 4720 Parent_Typ := Base_Type (Typ); 4721 while Parent_Typ /= Root_Typ loop 4722 Prepend_Elmt (Parent_Typ, To => Parent_Typ_List); 4723 Parent_Typ := Etype (Parent_Typ); 4724 4725 if Nkind (Parent (Base_Type (Parent_Typ))) = 4726 N_Private_Type_Declaration 4727 or else Nkind (Parent (Base_Type (Parent_Typ))) = 4728 N_Private_Extension_Declaration 4729 then 4730 if Nkind (N) /= N_Extension_Aggregate then 4731 Error_Msg_NE 4732 ("type of aggregate has private ancestor&!", 4733 N, Parent_Typ); 4734 Error_Msg_N ("must use extension aggregate!", N); 4735 return; 4736 4737 elsif Parent_Typ /= Root_Typ then 4738 Error_Msg_NE 4739 ("ancestor part of aggregate must be private type&", 4740 Ancestor_Part (N), Parent_Typ); 4741 return; 4742 end if; 4743 4744 -- The current view of ancestor part may be a private type, 4745 -- while the context type is always non-private. 4746 4747 elsif Is_Private_Type (Root_Typ) 4748 and then Present (Full_View (Root_Typ)) 4749 and then Nkind (N) = N_Extension_Aggregate 4750 then 4751 exit when Base_Type (Full_View (Root_Typ)) = Parent_Typ; 4752 end if; 4753 end loop; 4754 4755 -- Now collect components from all other ancestors, beginning 4756 -- with the current type. If the type has unknown discriminants 4757 -- use the component list of the Underlying_Record_View, which 4758 -- needs to be used for the subsequent expansion of the aggregate 4759 -- into assignments. 4760 4761 Parent_Elmt := First_Elmt (Parent_Typ_List); 4762 while Present (Parent_Elmt) loop 4763 Parent_Typ := Node (Parent_Elmt); 4764 4765 if Has_Unknown_Discriminants (Parent_Typ) 4766 and then Present (Underlying_Record_View (Typ)) 4767 then 4768 Parent_Typ := Underlying_Record_View (Parent_Typ); 4769 end if; 4770 4771 Record_Def := Type_Definition (Parent (Base_Type (Parent_Typ))); 4772 Gather_Components (Empty, 4773 Component_List (Record_Extension_Part (Record_Def)), 4774 Governed_By => New_Assoc_List, 4775 Into => Components, 4776 Report_Errors => Errors_Found); 4777 4778 Next_Elmt (Parent_Elmt); 4779 end loop; 4780 4781 -- Typ is not a derived tagged type 4782 4783 else 4784 Record_Def := Type_Definition (Parent (Base_Type (Typ))); 4785 4786 if Null_Present (Record_Def) then 4787 null; 4788 4789 elsif not Has_Unknown_Discriminants (Typ) then 4790 Gather_Components 4791 (Base_Type (Typ), 4792 Component_List (Record_Def), 4793 Governed_By => New_Assoc_List, 4794 Into => Components, 4795 Report_Errors => Errors_Found); 4796 4797 else 4798 Gather_Components 4799 (Base_Type (Underlying_Record_View (Typ)), 4800 Component_List (Record_Def), 4801 Governed_By => New_Assoc_List, 4802 Into => Components, 4803 Report_Errors => Errors_Found); 4804 end if; 4805 end if; 4806 4807 if Errors_Found then 4808 return; 4809 end if; 4810 end Step_5; 4811 4812 -- STEP 6: Find component Values 4813 4814 Component := Empty; 4815 Component_Elmt := First_Elmt (Components); 4816 4817 -- First scan the remaining positional associations in the aggregate. 4818 -- Remember that at this point Positional_Expr contains the current 4819 -- positional association if any is left after looking for discriminant 4820 -- values in step 3. 4821 4822 while Present (Positional_Expr) and then Present (Component_Elmt) loop 4823 Component := Node (Component_Elmt); 4824 Resolve_Aggr_Expr (Positional_Expr, Component); 4825 4826 -- Ada 2005 (AI-231) 4827 4828 if Ada_Version >= Ada_2005 and then Known_Null (Positional_Expr) then 4829 Check_Can_Never_Be_Null (Component, Positional_Expr); 4830 end if; 4831 4832 if Present (Get_Value (Component, Component_Associations (N))) then 4833 Error_Msg_NE 4834 ("more than one value supplied for Component &", N, Component); 4835 end if; 4836 4837 Next (Positional_Expr); 4838 Next_Elmt (Component_Elmt); 4839 end loop; 4840 4841 if Present (Positional_Expr) then 4842 Error_Msg_N 4843 ("too many components for record aggregate", Positional_Expr); 4844 end if; 4845 4846 -- Now scan for the named arguments of the aggregate 4847 4848 while Present (Component_Elmt) loop 4849 Component := Node (Component_Elmt); 4850 Expr := Get_Value (Component, Component_Associations (N), True); 4851 4852 -- Note: The previous call to Get_Value sets the value of the 4853 -- variable Is_Box_Present. 4854 4855 -- Ada 2005 (AI-287): Handle components with default initialization. 4856 -- Note: This feature was originally added to Ada 2005 for limited 4857 -- but it was finally allowed with any type. 4858 4859 if Is_Box_Present then 4860 Check_Box_Component : declare 4861 Ctyp : constant Entity_Id := Etype (Component); 4862 4863 begin 4864 -- If there is a default expression for the aggregate, copy 4865 -- it into a new association. This copy must modify the scopes 4866 -- of internal types that may be attached to the expression 4867 -- (e.g. index subtypes of arrays) because in general the type 4868 -- declaration and the aggregate appear in different scopes, 4869 -- and the backend requires the scope of the type to match the 4870 -- point at which it is elaborated. 4871 4872 -- If the component has an initialization procedure (IP) we 4873 -- pass the component to the expander, which will generate 4874 -- the call to such IP. 4875 4876 -- If the component has discriminants, their values must 4877 -- be taken from their subtype. This is indispensable for 4878 -- constraints that are given by the current instance of an 4879 -- enclosing type, to allow the expansion of the aggregate to 4880 -- replace the reference to the current instance by the target 4881 -- object of the aggregate. 4882 4883 if Present (Parent (Component)) 4884 and then Nkind (Parent (Component)) = N_Component_Declaration 4885 and then Present (Expression (Parent (Component))) 4886 then 4887 Expr := 4888 New_Copy_Tree_And_Copy_Dimensions 4889 (Expression (Parent (Component)), 4890 New_Scope => Current_Scope, 4891 New_Sloc => Sloc (N)); 4892 4893 -- As the type of the copied default expression may refer 4894 -- to discriminants of the record type declaration, these 4895 -- non-stored discriminants need to be rewritten into stored 4896 -- discriminant values for the aggregate. This is required 4897 -- in GNATprove mode, and is adopted in all modes to avoid 4898 -- special-casing GNATprove mode. 4899 4900 if Is_Array_Type (Etype (Expr)) then 4901 declare 4902 Rec_Typ : constant Entity_Id := Scope (Component); 4903 -- Root record type whose discriminants may be used as 4904 -- bounds in range nodes. 4905 4906 Index : Node_Id; 4907 4908 begin 4909 -- Rewrite the range nodes occurring in the indexes 4910 -- and their types. 4911 4912 Index := First_Index (Etype (Expr)); 4913 while Present (Index) loop 4914 Rewrite_Range (Rec_Typ, Index); 4915 Rewrite_Range 4916 (Rec_Typ, Scalar_Range (Etype (Index))); 4917 4918 Next_Index (Index); 4919 end loop; 4920 4921 -- Rewrite the range nodes occurring as aggregate 4922 -- bounds. 4923 4924 if Nkind (Expr) = N_Aggregate 4925 and then Present (Aggregate_Bounds (Expr)) 4926 then 4927 Rewrite_Range (Rec_Typ, Aggregate_Bounds (Expr)); 4928 end if; 4929 end; 4930 end if; 4931 4932 Add_Association 4933 (Component => Component, 4934 Expr => Expr, 4935 Assoc_List => New_Assoc_List); 4936 Set_Has_Self_Reference (N); 4937 4938 -- A box-defaulted access component gets the value null. Also 4939 -- included are components of private types whose underlying 4940 -- type is an access type. In either case set the type of the 4941 -- literal, for subsequent use in semantic checks. 4942 4943 elsif Present (Underlying_Type (Ctyp)) 4944 and then Is_Access_Type (Underlying_Type (Ctyp)) 4945 then 4946 -- If the component's type is private with an access type as 4947 -- its underlying type then we have to create an unchecked 4948 -- conversion to satisfy type checking. 4949 4950 if Is_Private_Type (Ctyp) then 4951 declare 4952 Qual_Null : constant Node_Id := 4953 Make_Qualified_Expression (Sloc (N), 4954 Subtype_Mark => 4955 New_Occurrence_Of 4956 (Underlying_Type (Ctyp), Sloc (N)), 4957 Expression => Make_Null (Sloc (N))); 4958 4959 Convert_Null : constant Node_Id := 4960 Unchecked_Convert_To 4961 (Ctyp, Qual_Null); 4962 4963 begin 4964 Analyze_And_Resolve (Convert_Null, Ctyp); 4965 Add_Association 4966 (Component => Component, 4967 Expr => Convert_Null, 4968 Assoc_List => New_Assoc_List); 4969 end; 4970 4971 -- Otherwise the component type is non-private 4972 4973 else 4974 Expr := Make_Null (Sloc (N)); 4975 Set_Etype (Expr, Ctyp); 4976 4977 Add_Association 4978 (Component => Component, 4979 Expr => Expr, 4980 Assoc_List => New_Assoc_List); 4981 end if; 4982 4983 -- Ada 2012: If component is scalar with default value, use it 4984 4985 elsif Is_Scalar_Type (Ctyp) 4986 and then Has_Default_Aspect (Ctyp) 4987 then 4988 Add_Association 4989 (Component => Component, 4990 Expr => 4991 Default_Aspect_Value 4992 (First_Subtype (Underlying_Type (Ctyp))), 4993 Assoc_List => New_Assoc_List); 4994 4995 elsif Has_Non_Null_Base_Init_Proc (Ctyp) 4996 or else not Expander_Active 4997 then 4998 if Is_Record_Type (Ctyp) 4999 and then Has_Discriminants (Ctyp) 5000 and then not Is_Private_Type (Ctyp) 5001 then 5002 -- We build a partially initialized aggregate with the 5003 -- values of the discriminants and box initialization 5004 -- for the rest, if other components are present. 5005 5006 -- The type of the aggregate is the known subtype of 5007 -- the component. The capture of discriminants must be 5008 -- recursive because subcomponents may be constrained 5009 -- (transitively) by discriminants of enclosing types. 5010 -- For a private type with discriminants, a call to the 5011 -- initialization procedure will be generated, and no 5012 -- subaggregate is needed. 5013 5014 Capture_Discriminants : declare 5015 Loc : constant Source_Ptr := Sloc (N); 5016 Expr : Node_Id; 5017 5018 begin 5019 Expr := Make_Aggregate (Loc, New_List, New_List); 5020 Set_Etype (Expr, Ctyp); 5021 5022 -- If the enclosing type has discriminants, they have 5023 -- been collected in the aggregate earlier, and they 5024 -- may appear as constraints of subcomponents. 5025 5026 -- Similarly if this component has discriminants, they 5027 -- might in turn be propagated to their components. 5028 5029 if Has_Discriminants (Typ) then 5030 Add_Discriminant_Values (Expr, New_Assoc_List); 5031 Propagate_Discriminants (Expr, New_Assoc_List); 5032 5033 elsif Has_Discriminants (Ctyp) then 5034 Add_Discriminant_Values 5035 (Expr, Component_Associations (Expr)); 5036 Propagate_Discriminants 5037 (Expr, Component_Associations (Expr)); 5038 5039 else 5040 declare 5041 Comp : Entity_Id; 5042 5043 begin 5044 -- If the type has additional components, create 5045 -- an OTHERS box association for them. 5046 5047 Comp := First_Component (Ctyp); 5048 while Present (Comp) loop 5049 if Ekind (Comp) = E_Component then 5050 if not Is_Record_Type (Etype (Comp)) then 5051 Append_To 5052 (Component_Associations (Expr), 5053 Make_Component_Association (Loc, 5054 Choices => 5055 New_List ( 5056 Make_Others_Choice (Loc)), 5057 Expression => Empty, 5058 Box_Present => True)); 5059 end if; 5060 5061 exit; 5062 end if; 5063 5064 Next_Component (Comp); 5065 end loop; 5066 end; 5067 end if; 5068 5069 Add_Association 5070 (Component => Component, 5071 Expr => Expr, 5072 Assoc_List => New_Assoc_List); 5073 end Capture_Discriminants; 5074 5075 -- Otherwise the component type is not a record, or it has 5076 -- not discriminants, or it is private. 5077 5078 else 5079 Add_Association 5080 (Component => Component, 5081 Expr => Empty, 5082 Assoc_List => New_Assoc_List, 5083 Is_Box_Present => True); 5084 end if; 5085 5086 -- Otherwise we only need to resolve the expression if the 5087 -- component has partially initialized values (required to 5088 -- expand the corresponding assignments and run-time checks). 5089 5090 elsif Present (Expr) 5091 and then Is_Partially_Initialized_Type (Ctyp) 5092 then 5093 Resolve_Aggr_Expr (Expr, Component); 5094 end if; 5095 end Check_Box_Component; 5096 5097 elsif No (Expr) then 5098 5099 -- Ignore hidden components associated with the position of the 5100 -- interface tags: these are initialized dynamically. 5101 5102 if not Present (Related_Type (Component)) then 5103 Error_Msg_NE 5104 ("no value supplied for component &!", N, Component); 5105 end if; 5106 5107 else 5108 Resolve_Aggr_Expr (Expr, Component); 5109 end if; 5110 5111 Next_Elmt (Component_Elmt); 5112 end loop; 5113 5114 -- STEP 7: check for invalid components + check type in choice list 5115 5116 Step_7 : declare 5117 Assoc : Node_Id; 5118 New_Assoc : Node_Id; 5119 5120 Selectr : Node_Id; 5121 -- Selector name 5122 5123 Typech : Entity_Id; 5124 -- Type of first component in choice list 5125 5126 begin 5127 if Present (Component_Associations (N)) then 5128 Assoc := First (Component_Associations (N)); 5129 else 5130 Assoc := Empty; 5131 end if; 5132 5133 Verification : while Present (Assoc) loop 5134 Selectr := First (Choices (Assoc)); 5135 Typech := Empty; 5136 5137 if Nkind (Selectr) = N_Others_Choice then 5138 5139 -- Ada 2005 (AI-287): others choice may have expression or box 5140 5141 if No (Others_Etype) and then Others_Box = 0 then 5142 Error_Msg_N 5143 ("OTHERS must represent at least one component", Selectr); 5144 5145 elsif Others_Box = 1 and then Warn_On_Redundant_Constructs then 5146 Error_Msg_N ("others choice is redundant?", Box_Node); 5147 Error_Msg_N 5148 ("\previous choices cover all components?", Box_Node); 5149 end if; 5150 5151 exit Verification; 5152 end if; 5153 5154 while Present (Selectr) loop 5155 New_Assoc := First (New_Assoc_List); 5156 while Present (New_Assoc) loop 5157 Component := First (Choices (New_Assoc)); 5158 5159 if Chars (Selectr) = Chars (Component) then 5160 if Style_Check then 5161 Check_Identifier (Selectr, Entity (Component)); 5162 end if; 5163 5164 exit; 5165 end if; 5166 5167 Next (New_Assoc); 5168 end loop; 5169 5170 -- If no association, this is not a legal component of the type 5171 -- in question, unless its association is provided with a box. 5172 5173 if No (New_Assoc) then 5174 if Box_Present (Parent (Selectr)) then 5175 5176 -- This may still be a bogus component with a box. Scan 5177 -- list of components to verify that a component with 5178 -- that name exists. 5179 5180 declare 5181 C : Entity_Id; 5182 5183 begin 5184 C := First_Component (Typ); 5185 while Present (C) loop 5186 if Chars (C) = Chars (Selectr) then 5187 5188 -- If the context is an extension aggregate, 5189 -- the component must not be inherited from 5190 -- the ancestor part of the aggregate. 5191 5192 if Nkind (N) /= N_Extension_Aggregate 5193 or else 5194 Scope (Original_Record_Component (C)) /= 5195 Etype (Ancestor_Part (N)) 5196 then 5197 exit; 5198 end if; 5199 end if; 5200 5201 Next_Component (C); 5202 end loop; 5203 5204 if No (C) then 5205 Error_Msg_Node_2 := Typ; 5206 Error_Msg_N ("& is not a component of}", Selectr); 5207 end if; 5208 end; 5209 5210 elsif Chars (Selectr) /= Name_uTag 5211 and then Chars (Selectr) /= Name_uParent 5212 then 5213 if not Has_Discriminants (Typ) then 5214 Error_Msg_Node_2 := Typ; 5215 Error_Msg_N ("& is not a component of}", Selectr); 5216 else 5217 Error_Msg_N 5218 ("& is not a component of the aggregate subtype", 5219 Selectr); 5220 end if; 5221 5222 Check_Misspelled_Component (Components, Selectr); 5223 end if; 5224 5225 elsif No (Typech) then 5226 Typech := Base_Type (Etype (Component)); 5227 5228 -- AI05-0199: In Ada 2012, several components of anonymous 5229 -- access types can appear in a choice list, as long as the 5230 -- designated types match. 5231 5232 elsif Typech /= Base_Type (Etype (Component)) then 5233 if Ada_Version >= Ada_2012 5234 and then Ekind (Typech) = E_Anonymous_Access_Type 5235 and then 5236 Ekind (Etype (Component)) = E_Anonymous_Access_Type 5237 and then Base_Type (Designated_Type (Typech)) = 5238 Base_Type (Designated_Type (Etype (Component))) 5239 and then 5240 Subtypes_Statically_Match (Typech, (Etype (Component))) 5241 then 5242 null; 5243 5244 elsif not Box_Present (Parent (Selectr)) then 5245 Error_Msg_N 5246 ("components in choice list must have same type", 5247 Selectr); 5248 end if; 5249 end if; 5250 5251 Next (Selectr); 5252 end loop; 5253 5254 Next (Assoc); 5255 end loop Verification; 5256 end Step_7; 5257 5258 -- STEP 8: replace the original aggregate 5259 5260 Step_8 : declare 5261 New_Aggregate : constant Node_Id := New_Copy (N); 5262 5263 begin 5264 Set_Expressions (New_Aggregate, No_List); 5265 Set_Etype (New_Aggregate, Etype (N)); 5266 Set_Component_Associations (New_Aggregate, New_Assoc_List); 5267 Set_Check_Actuals (New_Aggregate, Check_Actuals (N)); 5268 5269 Rewrite (N, New_Aggregate); 5270 end Step_8; 5271 5272 -- Check the dimensions of the components in the record aggregate 5273 5274 Analyze_Dimension_Extension_Or_Record_Aggregate (N); 5275 end Resolve_Record_Aggregate; 5276 5277 ----------------------------- 5278 -- Check_Can_Never_Be_Null -- 5279 ----------------------------- 5280 5281 procedure Check_Can_Never_Be_Null (Typ : Entity_Id; Expr : Node_Id) is 5282 Comp_Typ : Entity_Id; 5283 5284 begin 5285 pragma Assert 5286 (Ada_Version >= Ada_2005 5287 and then Present (Expr) 5288 and then Known_Null (Expr)); 5289 5290 case Ekind (Typ) is 5291 when E_Array_Type => 5292 Comp_Typ := Component_Type (Typ); 5293 5294 when E_Component 5295 | E_Discriminant 5296 => 5297 Comp_Typ := Etype (Typ); 5298 5299 when others => 5300 return; 5301 end case; 5302 5303 if Can_Never_Be_Null (Comp_Typ) then 5304 5305 -- Here we know we have a constraint error. Note that we do not use 5306 -- Apply_Compile_Time_Constraint_Error here to the Expr, which might 5307 -- seem the more natural approach. That's because in some cases the 5308 -- components are rewritten, and the replacement would be missed. 5309 -- We do not mark the whole aggregate as raising a constraint error, 5310 -- because the association may be a null array range. 5311 5312 Error_Msg_N 5313 ("(Ada 2005) null not allowed in null-excluding component??", Expr); 5314 Error_Msg_N 5315 ("\Constraint_Error will be raised at run time??", Expr); 5316 5317 Rewrite (Expr, 5318 Make_Raise_Constraint_Error 5319 (Sloc (Expr), Reason => CE_Access_Check_Failed)); 5320 Set_Etype (Expr, Comp_Typ); 5321 Set_Analyzed (Expr); 5322 end if; 5323 end Check_Can_Never_Be_Null; 5324 5325 --------------------- 5326 -- Sort_Case_Table -- 5327 --------------------- 5328 5329 procedure Sort_Case_Table (Case_Table : in out Case_Table_Type) is 5330 U : constant Int := Case_Table'Last; 5331 K : Int; 5332 J : Int; 5333 T : Case_Bounds; 5334 5335 begin 5336 K := 1; 5337 while K < U loop 5338 T := Case_Table (K + 1); 5339 5340 J := K + 1; 5341 while J > 1 5342 and then Expr_Value (Case_Table (J - 1).Lo) > Expr_Value (T.Lo) 5343 loop 5344 Case_Table (J) := Case_Table (J - 1); 5345 J := J - 1; 5346 end loop; 5347 5348 Case_Table (J) := T; 5349 K := K + 1; 5350 end loop; 5351 end Sort_Case_Table; 5352 5353end Sem_Aggr; 5354