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