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) 1992-2003 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 2, 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 COPYING. If not, write -- 19-- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, -- 20-- MA 02111-1307, USA. -- 21-- -- 22-- GNAT was originally developed by the GNAT team at New York University. -- 23-- Extensive contributions were provided by Ada Core Technologies Inc. -- 24-- -- 25------------------------------------------------------------------------------ 26 27with Atree; use Atree; 28with Checks; use Checks; 29with Einfo; use Einfo; 30with Elists; use Elists; 31with Errout; use Errout; 32with Exp_Tss; use Exp_Tss; 33with Exp_Util; use Exp_Util; 34with Freeze; use Freeze; 35with Itypes; use Itypes; 36with Lib.Xref; use Lib.Xref; 37with Namet; use Namet; 38with Nmake; use Nmake; 39with Nlists; use Nlists; 40with Opt; use Opt; 41with Sem; use Sem; 42with Sem_Cat; use Sem_Cat; 43with Sem_Ch8; use Sem_Ch8; 44with Sem_Ch13; use Sem_Ch13; 45with Sem_Eval; use Sem_Eval; 46with Sem_Res; use Sem_Res; 47with Sem_Util; use Sem_Util; 48with Sem_Type; use Sem_Type; 49with Sem_Warn; use Sem_Warn; 50with Sinfo; use Sinfo; 51with Snames; use Snames; 52with Stringt; use Stringt; 53with Stand; use Stand; 54with Targparm; use Targparm; 55with Tbuild; use Tbuild; 56with Uintp; use Uintp; 57 58with GNAT.Spelling_Checker; use GNAT.Spelling_Checker; 59 60package body Sem_Aggr is 61 62 type Case_Bounds is record 63 Choice_Lo : Node_Id; 64 Choice_Hi : Node_Id; 65 Choice_Node : Node_Id; 66 end record; 67 68 type Case_Table_Type is array (Nat range <>) of Case_Bounds; 69 -- Table type used by Check_Case_Choices procedure 70 71 ----------------------- 72 -- Local Subprograms -- 73 ----------------------- 74 75 procedure Sort_Case_Table (Case_Table : in out Case_Table_Type); 76 -- Sort the Case Table using the Lower Bound of each Choice as the key. 77 -- A simple insertion sort is used since the number of choices in a case 78 -- statement of variant part will usually be small and probably in near 79 -- sorted order. 80 81 ------------------------------------------------------ 82 -- Subprograms used for RECORD AGGREGATE Processing -- 83 ------------------------------------------------------ 84 85 procedure Resolve_Record_Aggregate (N : Node_Id; Typ : Entity_Id); 86 -- This procedure performs all the semantic checks required for record 87 -- aggregates. Note that for aggregates analysis and resolution go 88 -- hand in hand. Aggregate analysis has been delayed up to here and 89 -- it is done while resolving the aggregate. 90 -- 91 -- N is the N_Aggregate node. 92 -- Typ is the record type for the aggregate resolution 93 -- 94 -- While performing the semantic checks, this procedure 95 -- builds a new Component_Association_List where each record field 96 -- appears alone in a Component_Choice_List along with its corresponding 97 -- expression. The record fields in the Component_Association_List 98 -- appear in the same order in which they appear in the record type Typ. 99 -- 100 -- Once this new Component_Association_List is built and all the 101 -- semantic checks performed, the original aggregate subtree is replaced 102 -- with the new named record aggregate just built. Note that the subtree 103 -- substitution is performed with Rewrite so as to be 104 -- able to retrieve the original aggregate. 105 -- 106 -- The aggregate subtree manipulation performed by Resolve_Record_Aggregate 107 -- yields the aggregate format expected by Gigi. Typically, this kind of 108 -- tree manipulations are done in the expander. However, because the 109 -- semantic checks that need to be performed on record aggregates really 110 -- go hand in hand with the record aggregate normalization, the aggregate 111 -- subtree transformation is performed during resolution rather than 112 -- expansion. Had we decided otherwise we would have had to duplicate 113 -- most of the code in the expansion procedure Expand_Record_Aggregate. 114 -- Note, however, that all the expansion concerning aggegates for tagged 115 -- records is done in Expand_Record_Aggregate. 116 -- 117 -- The algorithm of Resolve_Record_Aggregate proceeds as follows: 118 -- 119 -- 1. Make sure that the record type against which the record aggregate 120 -- has to be resolved is not abstract. Furthermore if the type is 121 -- a null aggregate make sure the input aggregate N is also null. 122 -- 123 -- 2. Verify that the structure of the aggregate is that of a record 124 -- aggregate. Specifically, look for component associations and ensure 125 -- that each choice list only has identifiers or the N_Others_Choice 126 -- node. Also make sure that if present, the N_Others_Choice occurs 127 -- last and by itself. 128 -- 129 -- 3. If Typ contains discriminants, the values for each discriminant 130 -- is looked for. If the record type Typ has variants, we check 131 -- that the expressions corresponding to each discriminant ruling 132 -- the (possibly nested) variant parts of Typ, are static. This 133 -- allows us to determine the variant parts to which the rest of 134 -- the aggregate must conform. The names of discriminants with their 135 -- values are saved in a new association list, New_Assoc_List which 136 -- is later augmented with the names and values of the remaining 137 -- components in the record type. 138 -- 139 -- During this phase we also make sure that every discriminant is 140 -- assigned exactly one value. Note that when several values 141 -- for a given discriminant are found, semantic processing continues 142 -- looking for further errors. In this case it's the first 143 -- discriminant value found which we will be recorded. 144 -- 145 -- IMPORTANT NOTE: For derived tagged types this procedure expects 146 -- First_Discriminant and Next_Discriminant to give the correct list 147 -- of discriminants, in the correct order. 148 -- 149 -- 4. After all the discriminant values have been gathered, we can 150 -- set the Etype of the record aggregate. If Typ contains no 151 -- discriminants this is straightforward: the Etype of N is just 152 -- Typ, otherwise a new implicit constrained subtype of Typ is 153 -- built to be the Etype of N. 154 -- 155 -- 5. Gather the remaining record components according to the discriminant 156 -- values. This involves recursively traversing the record type 157 -- structure to see what variants are selected by the given discriminant 158 -- values. This processing is a little more convoluted if Typ is a 159 -- derived tagged types since we need to retrieve the record structure 160 -- of all the ancestors of Typ. 161 -- 162 -- 6. After gathering the record components we look for their values 163 -- in the record aggregate and emit appropriate error messages 164 -- should we not find such values or should they be duplicated. 165 -- 166 -- 7. We then make sure no illegal component names appear in the 167 -- record aggegate and make sure that the type of the record 168 -- components appearing in a same choice list is the same. 169 -- Finally we ensure that the others choice, if present, is 170 -- used to provide the value of at least a record component. 171 -- 172 -- 8. The original aggregate node is replaced with the new named 173 -- aggregate built in steps 3 through 6, as explained earlier. 174 -- 175 -- Given the complexity of record aggregate resolution, the primary 176 -- goal of this routine is clarity and simplicity rather than execution 177 -- and storage efficiency. If there are only positional components in the 178 -- aggregate the running time is linear. If there are associations 179 -- the running time is still linear as long as the order of the 180 -- associations is not too far off the order of the components in the 181 -- record type. If this is not the case the running time is at worst 182 -- quadratic in the size of the association list. 183 184 procedure Check_Misspelled_Component 185 (Elements : Elist_Id; 186 Component : Node_Id); 187 -- Give possible misspelling diagnostic if Component is likely to be 188 -- a misspelling of one of the components of the Assoc_List. 189 -- This is called by Resolv_Aggr_Expr after producing 190 -- an invalid component error message. 191 192 procedure Check_Static_Discriminated_Subtype (T : Entity_Id; V : Node_Id); 193 -- An optimization: determine whether a discriminated subtype has a 194 -- static constraint, and contains array components whose length is also 195 -- static, either because they are constrained by the discriminant, or 196 -- because the original component bounds are static. 197 198 ----------------------------------------------------- 199 -- Subprograms used for ARRAY AGGREGATE Processing -- 200 ----------------------------------------------------- 201 202 function Resolve_Array_Aggregate 203 (N : Node_Id; 204 Index : Node_Id; 205 Index_Constr : Node_Id; 206 Component_Typ : Entity_Id; 207 Others_Allowed : Boolean) 208 return Boolean; 209 -- This procedure performs the semantic checks for an array aggregate. 210 -- True is returned if the aggregate resolution succeeds. 211 -- The procedure works by recursively checking each nested aggregate. 212 -- Specifically, after checking a sub-aggreate nested at the i-th level 213 -- we recursively check all the subaggregates at the i+1-st level (if any). 214 -- Note that for aggregates analysis and resolution go hand in hand. 215 -- Aggregate analysis has been delayed up to here and it is done while 216 -- resolving the aggregate. 217 -- 218 -- N is the current N_Aggregate node to be checked. 219 -- 220 -- Index is the index node corresponding to the array sub-aggregate that 221 -- we are currently checking (RM 4.3.3 (8)). Its Etype is the 222 -- corresponding index type (or subtype). 223 -- 224 -- Index_Constr is the node giving the applicable index constraint if 225 -- any (RM 4.3.3 (10)). It "is a constraint provided by certain 226 -- contexts [...] that can be used to determine the bounds of the array 227 -- value specified by the aggregate". If Others_Allowed below is False 228 -- there is no applicable index constraint and this node is set to Index. 229 -- 230 -- Component_Typ is the array component type. 231 -- 232 -- Others_Allowed indicates whether an others choice is allowed 233 -- in the context where the top-level aggregate appeared. 234 -- 235 -- The algorithm of Resolve_Array_Aggregate proceeds as follows: 236 -- 237 -- 1. Make sure that the others choice, if present, is by itself and 238 -- appears last in the sub-aggregate. Check that we do not have 239 -- positional and named components in the array sub-aggregate (unless 240 -- the named association is an others choice). Finally if an others 241 -- choice is present, make sure it is allowed in the aggregate contex. 242 -- 243 -- 2. If the array sub-aggregate contains discrete_choices: 244 -- 245 -- (A) Verify their validity. Specifically verify that: 246 -- 247 -- (a) If a null range is present it must be the only possible 248 -- choice in the array aggregate. 249 -- 250 -- (b) Ditto for a non static range. 251 -- 252 -- (c) Ditto for a non static expression. 253 -- 254 -- In addition this step analyzes and resolves each discrete_choice, 255 -- making sure that its type is the type of the corresponding Index. 256 -- If we are not at the lowest array aggregate level (in the case of 257 -- multi-dimensional aggregates) then invoke Resolve_Array_Aggregate 258 -- recursively on each component expression. Otherwise, resolve the 259 -- bottom level component expressions against the expected component 260 -- type ONLY IF the component corresponds to a single discrete choice 261 -- which is not an others choice (to see why read the DELAYED 262 -- COMPONENT RESOLUTION below). 263 -- 264 -- (B) Determine the bounds of the sub-aggregate and lowest and 265 -- highest choice values. 266 -- 267 -- 3. For positional aggregates: 268 -- 269 -- (A) Loop over the component expressions either recursively invoking 270 -- Resolve_Array_Aggregate on each of these for multi-dimensional 271 -- array aggregates or resolving the bottom level component 272 -- expressions against the expected component type. 273 -- 274 -- (B) Determine the bounds of the positional sub-aggregates. 275 -- 276 -- 4. Try to determine statically whether the evaluation of the array 277 -- sub-aggregate raises Constraint_Error. If yes emit proper 278 -- warnings. The precise checks are the following: 279 -- 280 -- (A) Check that the index range defined by aggregate bounds is 281 -- compatible with corresponding index subtype. 282 -- We also check against the base type. In fact it could be that 283 -- Low/High bounds of the base type are static whereas those of 284 -- the index subtype are not. Thus if we can statically catch 285 -- a problem with respect to the base type we are guaranteed 286 -- that the same problem will arise with the index subtype 287 -- 288 -- (B) If we are dealing with a named aggregate containing an others 289 -- choice and at least one discrete choice then make sure the range 290 -- specified by the discrete choices does not overflow the 291 -- aggregate bounds. We also check against the index type and base 292 -- type bounds for the same reasons given in (A). 293 -- 294 -- (C) If we are dealing with a positional aggregate with an others 295 -- choice make sure the number of positional elements specified 296 -- does not overflow the aggregate bounds. We also check against 297 -- the index type and base type bounds as mentioned in (A). 298 -- 299 -- Finally construct an N_Range node giving the sub-aggregate bounds. 300 -- Set the Aggregate_Bounds field of the sub-aggregate to be this 301 -- N_Range. The routine Array_Aggr_Subtype below uses such N_Ranges 302 -- to build the appropriate aggregate subtype. Aggregate_Bounds 303 -- information is needed during expansion. 304 -- 305 -- DELAYED COMPONENT RESOLUTION: The resolution of bottom level component 306 -- expressions in an array aggregate may call Duplicate_Subexpr or some 307 -- other routine that inserts code just outside the outermost aggregate. 308 -- If the array aggregate contains discrete choices or an others choice, 309 -- this may be wrong. Consider for instance the following example. 310 -- 311 -- type Rec is record 312 -- V : Integer := 0; 313 -- end record; 314 -- 315 -- type Acc_Rec is access Rec; 316 -- Arr : array (1..3) of Acc_Rec := (1 .. 3 => new Rec); 317 -- 318 -- Then the transformation of "new Rec" that occurs during resolution 319 -- entails the following code modifications 320 -- 321 -- P7b : constant Acc_Rec := new Rec; 322 -- RecIP (P7b.all); 323 -- Arr : array (1..3) of Acc_Rec := (1 .. 3 => P7b); 324 -- 325 -- This code transformation is clearly wrong, since we need to call 326 -- "new Rec" for each of the 3 array elements. To avoid this problem we 327 -- delay resolution of the components of non positional array aggregates 328 -- to the expansion phase. As an optimization, if the discrete choice 329 -- specifies a single value we do not delay resolution. 330 331 function Array_Aggr_Subtype (N : Node_Id; Typ : Node_Id) return Entity_Id; 332 -- This routine returns the type or subtype of an array aggregate. 333 -- 334 -- N is the array aggregate node whose type we return. 335 -- 336 -- Typ is the context type in which N occurs. 337 -- 338 -- This routine creates an implicit array subtype whose bounds are 339 -- those defined by the aggregate. When this routine is invoked 340 -- Resolve_Array_Aggregate has already processed aggregate N. Thus the 341 -- Aggregate_Bounds of each sub-aggregate, is an N_Range node giving the 342 -- sub-aggregate bounds. When building the aggegate itype, this function 343 -- traverses the array aggregate N collecting such Aggregate_Bounds and 344 -- constructs the proper array aggregate itype. 345 -- 346 -- Note that in the case of multidimensional aggregates each inner 347 -- sub-aggregate corresponding to a given array dimension, may provide a 348 -- different bounds. If it is possible to determine statically that 349 -- some sub-aggregates corresponding to the same index do not have the 350 -- same bounds, then a warning is emitted. If such check is not possible 351 -- statically (because some sub-aggregate bounds are dynamic expressions) 352 -- then this job is left to the expander. In all cases the particular 353 -- bounds that this function will chose for a given dimension is the first 354 -- N_Range node for a sub-aggregate corresponding to that dimension. 355 -- 356 -- Note that the Raises_Constraint_Error flag of an array aggregate 357 -- whose evaluation is determined to raise CE by Resolve_Array_Aggregate, 358 -- is set in Resolve_Array_Aggregate but the aggregate is not 359 -- immediately replaced with a raise CE. In fact, Array_Aggr_Subtype must 360 -- first construct the proper itype for the aggregate (Gigi needs 361 -- this). After constructing the proper itype we will eventually replace 362 -- the top-level aggregate with a raise CE (done in Resolve_Aggregate). 363 -- Of course in cases such as: 364 -- 365 -- type Arr is array (integer range <>) of Integer; 366 -- A : Arr := (positive range -1 .. 2 => 0); 367 -- 368 -- The bounds of the aggregate itype are cooked up to look reasonable 369 -- (in this particular case the bounds will be 1 .. 2). 370 371 procedure Aggregate_Constraint_Checks 372 (Exp : Node_Id; 373 Check_Typ : Entity_Id); 374 -- Checks expression Exp against subtype Check_Typ. If Exp is an 375 -- aggregate and Check_Typ a constrained record type with discriminants, 376 -- we generate the appropriate discriminant checks. If Exp is an array 377 -- aggregate then emit the appropriate length checks. If Exp is a scalar 378 -- type, or a string literal, Exp is changed into Check_Typ'(Exp) to 379 -- ensure that range checks are performed at run time. 380 381 procedure Make_String_Into_Aggregate (N : Node_Id); 382 -- A string literal can appear in a context in which a one dimensional 383 -- array of characters is expected. This procedure simply rewrites the 384 -- string as an aggregate, prior to resolution. 385 386 --------------------------------- 387 -- Aggregate_Constraint_Checks -- 388 --------------------------------- 389 390 procedure Aggregate_Constraint_Checks 391 (Exp : Node_Id; 392 Check_Typ : Entity_Id) 393 is 394 Exp_Typ : constant Entity_Id := Etype (Exp); 395 396 begin 397 if Raises_Constraint_Error (Exp) then 398 return; 399 end if; 400 401 -- This is really expansion activity, so make sure that expansion 402 -- is on and is allowed. 403 404 if not Expander_Active or else In_Default_Expression then 405 return; 406 end if; 407 408 -- First check if we have to insert discriminant checks 409 410 if Has_Discriminants (Exp_Typ) then 411 Apply_Discriminant_Check (Exp, Check_Typ); 412 413 -- Next emit length checks for array aggregates 414 415 elsif Is_Array_Type (Exp_Typ) then 416 Apply_Length_Check (Exp, Check_Typ); 417 418 -- Finally emit scalar and string checks. If we are dealing with a 419 -- scalar literal we need to check by hand because the Etype of 420 -- literals is not necessarily correct. 421 422 elsif Is_Scalar_Type (Exp_Typ) 423 and then Compile_Time_Known_Value (Exp) 424 then 425 if Is_Out_Of_Range (Exp, Base_Type (Check_Typ)) then 426 Apply_Compile_Time_Constraint_Error 427 (Exp, "value not in range of}?", CE_Range_Check_Failed, 428 Ent => Base_Type (Check_Typ), 429 Typ => Base_Type (Check_Typ)); 430 431 elsif Is_Out_Of_Range (Exp, Check_Typ) then 432 Apply_Compile_Time_Constraint_Error 433 (Exp, "value not in range of}?", CE_Range_Check_Failed, 434 Ent => Check_Typ, 435 Typ => Check_Typ); 436 437 elsif not Range_Checks_Suppressed (Check_Typ) then 438 Apply_Scalar_Range_Check (Exp, Check_Typ); 439 end if; 440 441 elsif (Is_Scalar_Type (Exp_Typ) 442 or else Nkind (Exp) = N_String_Literal) 443 and then Exp_Typ /= Check_Typ 444 then 445 if Is_Entity_Name (Exp) 446 and then Ekind (Entity (Exp)) = E_Constant 447 then 448 -- If expression is a constant, it is worthwhile checking whether 449 -- it is a bound of the type. 450 451 if (Is_Entity_Name (Type_Low_Bound (Check_Typ)) 452 and then Entity (Exp) = Entity (Type_Low_Bound (Check_Typ))) 453 or else (Is_Entity_Name (Type_High_Bound (Check_Typ)) 454 and then Entity (Exp) = Entity (Type_High_Bound (Check_Typ))) 455 then 456 return; 457 458 else 459 Rewrite (Exp, Convert_To (Check_Typ, Relocate_Node (Exp))); 460 Analyze_And_Resolve (Exp, Check_Typ); 461 Check_Unset_Reference (Exp); 462 end if; 463 else 464 Rewrite (Exp, Convert_To (Check_Typ, Relocate_Node (Exp))); 465 Analyze_And_Resolve (Exp, Check_Typ); 466 Check_Unset_Reference (Exp); 467 end if; 468 end if; 469 end Aggregate_Constraint_Checks; 470 471 ------------------------ 472 -- Array_Aggr_Subtype -- 473 ------------------------ 474 475 function Array_Aggr_Subtype 476 (N : Node_Id; 477 Typ : Entity_Id) 478 return Entity_Id 479 is 480 Aggr_Dimension : constant Pos := Number_Dimensions (Typ); 481 -- Number of aggregate index dimensions. 482 483 Aggr_Range : array (1 .. Aggr_Dimension) of Node_Id := (others => Empty); 484 -- Constrained N_Range of each index dimension in our aggregate itype. 485 486 Aggr_Low : array (1 .. Aggr_Dimension) of Node_Id := (others => Empty); 487 Aggr_High : array (1 .. Aggr_Dimension) of Node_Id := (others => Empty); 488 -- Low and High bounds for each index dimension in our aggregate itype. 489 490 Is_Fully_Positional : Boolean := True; 491 492 procedure Collect_Aggr_Bounds (N : Node_Id; Dim : Pos); 493 -- N is an array (sub-)aggregate. Dim is the dimension corresponding to 494 -- (sub-)aggregate N. This procedure collects the constrained N_Range 495 -- nodes corresponding to each index dimension of our aggregate itype. 496 -- These N_Range nodes are collected in Aggr_Range above. 497 -- Likewise collect in Aggr_Low & Aggr_High above the low and high 498 -- bounds of each index dimension. If, when collecting, two bounds 499 -- corresponding to the same dimension are static and found to differ, 500 -- then emit a warning, and mark N as raising Constraint_Error. 501 502 ------------------------- 503 -- Collect_Aggr_Bounds -- 504 ------------------------- 505 506 procedure Collect_Aggr_Bounds (N : Node_Id; Dim : Pos) is 507 This_Range : constant Node_Id := Aggregate_Bounds (N); 508 -- The aggregate range node of this specific sub-aggregate. 509 510 This_Low : constant Node_Id := Low_Bound (Aggregate_Bounds (N)); 511 This_High : constant Node_Id := High_Bound (Aggregate_Bounds (N)); 512 -- The aggregate bounds of this specific sub-aggregate. 513 514 Assoc : Node_Id; 515 Expr : Node_Id; 516 517 begin 518 -- Collect the first N_Range for a given dimension that you find. 519 -- For a given dimension they must be all equal anyway. 520 521 if No (Aggr_Range (Dim)) then 522 Aggr_Low (Dim) := This_Low; 523 Aggr_High (Dim) := This_High; 524 Aggr_Range (Dim) := This_Range; 525 526 else 527 if Compile_Time_Known_Value (This_Low) then 528 if not Compile_Time_Known_Value (Aggr_Low (Dim)) then 529 Aggr_Low (Dim) := This_Low; 530 531 elsif Expr_Value (This_Low) /= Expr_Value (Aggr_Low (Dim)) then 532 Set_Raises_Constraint_Error (N); 533 Error_Msg_N ("Sub-aggregate low bound mismatch?", N); 534 Error_Msg_N ("Constraint_Error will be raised at run-time?", 535 N); 536 end if; 537 end if; 538 539 if Compile_Time_Known_Value (This_High) then 540 if not Compile_Time_Known_Value (Aggr_High (Dim)) then 541 Aggr_High (Dim) := This_High; 542 543 elsif 544 Expr_Value (This_High) /= Expr_Value (Aggr_High (Dim)) 545 then 546 Set_Raises_Constraint_Error (N); 547 Error_Msg_N ("Sub-aggregate high bound mismatch?", N); 548 Error_Msg_N ("Constraint_Error will be raised at run-time?", 549 N); 550 end if; 551 end if; 552 end if; 553 554 if Dim < Aggr_Dimension then 555 556 -- Process positional components 557 558 if Present (Expressions (N)) then 559 Expr := First (Expressions (N)); 560 while Present (Expr) loop 561 Collect_Aggr_Bounds (Expr, Dim + 1); 562 Next (Expr); 563 end loop; 564 end if; 565 566 -- Process component associations 567 568 if Present (Component_Associations (N)) then 569 Is_Fully_Positional := False; 570 571 Assoc := First (Component_Associations (N)); 572 while Present (Assoc) loop 573 Expr := Expression (Assoc); 574 Collect_Aggr_Bounds (Expr, Dim + 1); 575 Next (Assoc); 576 end loop; 577 end if; 578 end if; 579 end Collect_Aggr_Bounds; 580 581 -- Array_Aggr_Subtype variables 582 583 Itype : Entity_Id; 584 -- the final itype of the overall aggregate 585 586 Index_Constraints : constant List_Id := New_List; 587 -- The list of index constraints of the aggregate itype. 588 589 -- Start of processing for Array_Aggr_Subtype 590 591 begin 592 -- Make sure that the list of index constraints is properly attached 593 -- to the tree, and then collect the aggregate bounds. 594 595 Set_Parent (Index_Constraints, N); 596 Collect_Aggr_Bounds (N, 1); 597 598 -- Build the list of constrained indices of our aggregate itype. 599 600 for J in 1 .. Aggr_Dimension loop 601 Create_Index : declare 602 Index_Base : constant Entity_Id := 603 Base_Type (Etype (Aggr_Range (J))); 604 Index_Typ : Entity_Id; 605 606 begin 607 -- Construct the Index subtype 608 609 Index_Typ := Create_Itype (Subtype_Kind (Ekind (Index_Base)), N); 610 611 Set_Etype (Index_Typ, Index_Base); 612 613 if Is_Character_Type (Index_Base) then 614 Set_Is_Character_Type (Index_Typ); 615 end if; 616 617 Set_Size_Info (Index_Typ, (Index_Base)); 618 Set_RM_Size (Index_Typ, RM_Size (Index_Base)); 619 Set_First_Rep_Item (Index_Typ, First_Rep_Item (Index_Base)); 620 Set_Scalar_Range (Index_Typ, Aggr_Range (J)); 621 622 if Is_Discrete_Or_Fixed_Point_Type (Index_Typ) then 623 Set_RM_Size (Index_Typ, UI_From_Int (Minimum_Size (Index_Typ))); 624 end if; 625 626 Set_Etype (Aggr_Range (J), Index_Typ); 627 628 Append (Aggr_Range (J), To => Index_Constraints); 629 end Create_Index; 630 end loop; 631 632 -- Now build the Itype 633 634 Itype := Create_Itype (E_Array_Subtype, N); 635 636 Set_First_Rep_Item (Itype, First_Rep_Item (Typ)); 637 Set_Convention (Itype, Convention (Typ)); 638 Set_Depends_On_Private (Itype, Has_Private_Component (Typ)); 639 Set_Etype (Itype, Base_Type (Typ)); 640 Set_Has_Alignment_Clause (Itype, Has_Alignment_Clause (Typ)); 641 Set_Is_Aliased (Itype, Is_Aliased (Typ)); 642 Set_Depends_On_Private (Itype, Depends_On_Private (Typ)); 643 644 Copy_Suppress_Status (Index_Check, Typ, Itype); 645 Copy_Suppress_Status (Length_Check, Typ, Itype); 646 647 Set_First_Index (Itype, First (Index_Constraints)); 648 Set_Is_Constrained (Itype, True); 649 Set_Is_Internal (Itype, True); 650 Init_Size_Align (Itype); 651 652 -- A simple optimization: purely positional aggregates of static 653 -- components should be passed to gigi unexpanded whenever possible, 654 -- and regardless of the staticness of the bounds themselves. Subse- 655 -- quent checks in exp_aggr verify that type is not packed, etc. 656 657 Set_Size_Known_At_Compile_Time (Itype, 658 Is_Fully_Positional 659 and then Comes_From_Source (N) 660 and then Size_Known_At_Compile_Time (Component_Type (Typ))); 661 662 -- We always need a freeze node for a packed array subtype, so that 663 -- we can build the Packed_Array_Type corresponding to the subtype. 664 -- If expansion is disabled, the packed array subtype is not built, 665 -- and we must not generate a freeze node for the type, or else it 666 -- will appear incomplete to gigi. 667 668 if Is_Packed (Itype) and then not In_Default_Expression 669 and then Expander_Active 670 then 671 Freeze_Itype (Itype, N); 672 end if; 673 674 return Itype; 675 end Array_Aggr_Subtype; 676 677 -------------------------------- 678 -- Check_Misspelled_Component -- 679 -------------------------------- 680 681 procedure Check_Misspelled_Component 682 (Elements : Elist_Id; 683 Component : Node_Id) 684 is 685 Max_Suggestions : constant := 2; 686 687 Nr_Of_Suggestions : Natural := 0; 688 Suggestion_1 : Entity_Id := Empty; 689 Suggestion_2 : Entity_Id := Empty; 690 Component_Elmt : Elmt_Id; 691 692 begin 693 -- All the components of List are matched against Component and 694 -- a count is maintained of possible misspellings. When at the 695 -- end of the analysis there are one or two (not more!) possible 696 -- misspellings, these misspellings will be suggested as 697 -- possible correction. 698 699 Get_Name_String (Chars (Component)); 700 701 declare 702 S : constant String (1 .. Name_Len) := 703 Name_Buffer (1 .. Name_Len); 704 705 begin 706 707 Component_Elmt := First_Elmt (Elements); 708 709 while Nr_Of_Suggestions <= Max_Suggestions 710 and then Present (Component_Elmt) 711 loop 712 713 Get_Name_String (Chars (Node (Component_Elmt))); 714 715 if Is_Bad_Spelling_Of (Name_Buffer (1 .. Name_Len), S) then 716 Nr_Of_Suggestions := Nr_Of_Suggestions + 1; 717 718 case Nr_Of_Suggestions is 719 when 1 => Suggestion_1 := Node (Component_Elmt); 720 when 2 => Suggestion_2 := Node (Component_Elmt); 721 when others => exit; 722 end case; 723 end if; 724 725 Next_Elmt (Component_Elmt); 726 end loop; 727 728 -- Report at most two suggestions 729 730 if Nr_Of_Suggestions = 1 then 731 Error_Msg_NE ("\possible misspelling of&", 732 Component, Suggestion_1); 733 734 elsif Nr_Of_Suggestions = 2 then 735 Error_Msg_Node_2 := Suggestion_2; 736 Error_Msg_NE ("\possible misspelling of& or&", 737 Component, Suggestion_1); 738 end if; 739 end; 740 end Check_Misspelled_Component; 741 742 ---------------------------------------- 743 -- Check_Static_Discriminated_Subtype -- 744 ---------------------------------------- 745 746 procedure Check_Static_Discriminated_Subtype (T : Entity_Id; V : Node_Id) is 747 Disc : constant Entity_Id := First_Discriminant (T); 748 Comp : Entity_Id; 749 Ind : Entity_Id; 750 751 begin 752 if Has_Record_Rep_Clause (T) then 753 return; 754 755 elsif Present (Next_Discriminant (Disc)) then 756 return; 757 758 elsif Nkind (V) /= N_Integer_Literal then 759 return; 760 end if; 761 762 Comp := First_Component (T); 763 764 while Present (Comp) loop 765 766 if Is_Scalar_Type (Etype (Comp)) then 767 null; 768 769 elsif Is_Private_Type (Etype (Comp)) 770 and then Present (Full_View (Etype (Comp))) 771 and then Is_Scalar_Type (Full_View (Etype (Comp))) 772 then 773 null; 774 775 elsif Is_Array_Type (Etype (Comp)) then 776 777 if Is_Bit_Packed_Array (Etype (Comp)) then 778 return; 779 end if; 780 781 Ind := First_Index (Etype (Comp)); 782 783 while Present (Ind) loop 784 785 if Nkind (Ind) /= N_Range 786 or else Nkind (Low_Bound (Ind)) /= N_Integer_Literal 787 or else Nkind (High_Bound (Ind)) /= N_Integer_Literal 788 then 789 return; 790 end if; 791 792 Next_Index (Ind); 793 end loop; 794 795 else 796 return; 797 end if; 798 799 Next_Component (Comp); 800 end loop; 801 802 -- On exit, all components have statically known sizes. 803 804 Set_Size_Known_At_Compile_Time (T); 805 end Check_Static_Discriminated_Subtype; 806 807 -------------------------------- 808 -- Make_String_Into_Aggregate -- 809 -------------------------------- 810 811 procedure Make_String_Into_Aggregate (N : Node_Id) is 812 Exprs : constant List_Id := New_List; 813 Loc : constant Source_Ptr := Sloc (N); 814 Str : constant String_Id := Strval (N); 815 Strlen : constant Nat := String_Length (Str); 816 C : Char_Code; 817 C_Node : Node_Id; 818 New_N : Node_Id; 819 P : Source_Ptr; 820 821 begin 822 P := Loc + 1; 823 for J in 1 .. Strlen loop 824 C := Get_String_Char (Str, J); 825 Set_Character_Literal_Name (C); 826 827 C_Node := Make_Character_Literal (P, Name_Find, C); 828 Set_Etype (C_Node, Any_Character); 829 Append_To (Exprs, C_Node); 830 831 P := P + 1; 832 -- something special for wide strings ??? 833 end loop; 834 835 New_N := Make_Aggregate (Loc, Expressions => Exprs); 836 Set_Analyzed (New_N); 837 Set_Etype (New_N, Any_Composite); 838 839 Rewrite (N, New_N); 840 end Make_String_Into_Aggregate; 841 842 ----------------------- 843 -- Resolve_Aggregate -- 844 ----------------------- 845 846 procedure Resolve_Aggregate (N : Node_Id; Typ : Entity_Id) is 847 Pkind : constant Node_Kind := Nkind (Parent (N)); 848 849 Aggr_Subtyp : Entity_Id; 850 -- The actual aggregate subtype. This is not necessarily the same as Typ 851 -- which is the subtype of the context in which the aggregate was found. 852 853 begin 854 -- Check for aggregates not allowed in configurable run-time mode. 855 -- We allow all cases of aggregates that do not come from source, 856 -- since these are all assumed to be small (e.g. bounds of a string 857 -- literal). We also allow aggregates of types we know to be small. 858 859 if not Support_Aggregates_On_Target 860 and then Comes_From_Source (N) 861 and then (not Known_Static_Esize (Typ) or else Esize (Typ) > 64) 862 then 863 Error_Msg_CRT ("aggregate", N); 864 end if; 865 866 if Is_Limited_Composite (Typ) then 867 Error_Msg_N ("aggregate type cannot have limited component", N); 868 Explain_Limited_Type (Typ, N); 869 870 -- Ada0Y (AI-287): Limited aggregates allowed 871 872 elsif Is_Limited_Type (Typ) 873 and not Extensions_Allowed 874 then 875 Error_Msg_N ("aggregate type cannot be limited", N); 876 Explain_Limited_Type (Typ, N); 877 878 elsif Is_Class_Wide_Type (Typ) then 879 Error_Msg_N ("type of aggregate cannot be class-wide", N); 880 881 elsif Typ = Any_String 882 or else Typ = Any_Composite 883 then 884 Error_Msg_N ("no unique type for aggregate", N); 885 Set_Etype (N, Any_Composite); 886 887 elsif Is_Array_Type (Typ) and then Null_Record_Present (N) then 888 Error_Msg_N ("null record forbidden in array aggregate", N); 889 890 elsif Is_Record_Type (Typ) then 891 Resolve_Record_Aggregate (N, Typ); 892 893 elsif Is_Array_Type (Typ) then 894 895 -- First a special test, for the case of a positional aggregate 896 -- of characters which can be replaced by a string literal. 897 -- Do not perform this transformation if this was a string literal 898 -- to start with, whose components needed constraint checks, or if 899 -- the component type is non-static, because it will require those 900 -- checks and be transformed back into an aggregate. 901 902 if Number_Dimensions (Typ) = 1 903 and then 904 (Root_Type (Component_Type (Typ)) = Standard_Character 905 or else 906 Root_Type (Component_Type (Typ)) = Standard_Wide_Character) 907 and then No (Component_Associations (N)) 908 and then not Is_Limited_Composite (Typ) 909 and then not Is_Private_Composite (Typ) 910 and then not Is_Bit_Packed_Array (Typ) 911 and then Nkind (Original_Node (Parent (N))) /= N_String_Literal 912 and then Is_Static_Subtype (Component_Type (Typ)) 913 then 914 declare 915 Expr : Node_Id; 916 917 begin 918 Expr := First (Expressions (N)); 919 while Present (Expr) loop 920 exit when Nkind (Expr) /= N_Character_Literal; 921 Next (Expr); 922 end loop; 923 924 if No (Expr) then 925 Start_String; 926 927 Expr := First (Expressions (N)); 928 while Present (Expr) loop 929 Store_String_Char (Char_Literal_Value (Expr)); 930 Next (Expr); 931 end loop; 932 933 Rewrite (N, 934 Make_String_Literal (Sloc (N), End_String)); 935 936 Analyze_And_Resolve (N, Typ); 937 return; 938 end if; 939 end; 940 end if; 941 942 -- Here if we have a real aggregate to deal with 943 944 Array_Aggregate : declare 945 Aggr_Resolved : Boolean; 946 947 Aggr_Typ : constant Entity_Id := Etype (Typ); 948 -- This is the unconstrained array type, which is the type 949 -- against which the aggregate is to be resoved. Typ itself 950 -- is the array type of the context which may not be the same 951 -- subtype as the subtype for the final aggregate. 952 953 begin 954 -- In the following we determine whether an others choice is 955 -- allowed inside the array aggregate. The test checks the context 956 -- in which the array aggregate occurs. If the context does not 957 -- permit it, or the aggregate type is unconstrained, an others 958 -- choice is not allowed. 959 -- 960 -- Note that there is no node for Explicit_Actual_Parameter. 961 -- To test for this context we therefore have to test for node 962 -- N_Parameter_Association which itself appears only if there is a 963 -- formal parameter. Consequently we also need to test for 964 -- N_Procedure_Call_Statement or N_Function_Call. 965 966 Set_Etype (N, Aggr_Typ); -- may be overridden later on. 967 968 if Is_Constrained (Typ) and then 969 (Pkind = N_Assignment_Statement or else 970 Pkind = N_Parameter_Association or else 971 Pkind = N_Function_Call or else 972 Pkind = N_Procedure_Call_Statement or else 973 Pkind = N_Generic_Association or else 974 Pkind = N_Formal_Object_Declaration or else 975 Pkind = N_Return_Statement or else 976 Pkind = N_Object_Declaration or else 977 Pkind = N_Component_Declaration or else 978 Pkind = N_Parameter_Specification or else 979 Pkind = N_Qualified_Expression or else 980 Pkind = N_Aggregate or else 981 Pkind = N_Extension_Aggregate or else 982 Pkind = N_Component_Association) 983 then 984 Aggr_Resolved := 985 Resolve_Array_Aggregate 986 (N, 987 Index => First_Index (Aggr_Typ), 988 Index_Constr => First_Index (Typ), 989 Component_Typ => Component_Type (Typ), 990 Others_Allowed => True); 991 992 else 993 Aggr_Resolved := 994 Resolve_Array_Aggregate 995 (N, 996 Index => First_Index (Aggr_Typ), 997 Index_Constr => First_Index (Aggr_Typ), 998 Component_Typ => Component_Type (Typ), 999 Others_Allowed => False); 1000 end if; 1001 1002 if not Aggr_Resolved then 1003 Aggr_Subtyp := Any_Composite; 1004 else 1005 Aggr_Subtyp := Array_Aggr_Subtype (N, Typ); 1006 end if; 1007 1008 Set_Etype (N, Aggr_Subtyp); 1009 end Array_Aggregate; 1010 1011 else 1012 Error_Msg_N ("illegal context for aggregate", N); 1013 1014 end if; 1015 1016 -- If we can determine statically that the evaluation of the 1017 -- aggregate raises Constraint_Error, then replace the 1018 -- aggregate with an N_Raise_Constraint_Error node, but set the 1019 -- Etype to the right aggregate subtype. Gigi needs this. 1020 1021 if Raises_Constraint_Error (N) then 1022 Aggr_Subtyp := Etype (N); 1023 Rewrite (N, 1024 Make_Raise_Constraint_Error (Sloc (N), 1025 Reason => CE_Range_Check_Failed)); 1026 Set_Raises_Constraint_Error (N); 1027 Set_Etype (N, Aggr_Subtyp); 1028 Set_Analyzed (N); 1029 end if; 1030 end Resolve_Aggregate; 1031 1032 ----------------------------- 1033 -- Resolve_Array_Aggregate -- 1034 ----------------------------- 1035 1036 function Resolve_Array_Aggregate 1037 (N : Node_Id; 1038 Index : Node_Id; 1039 Index_Constr : Node_Id; 1040 Component_Typ : Entity_Id; 1041 Others_Allowed : Boolean) 1042 return Boolean 1043 is 1044 Loc : constant Source_Ptr := Sloc (N); 1045 1046 Failure : constant Boolean := False; 1047 Success : constant Boolean := True; 1048 1049 Index_Typ : constant Entity_Id := Etype (Index); 1050 Index_Typ_Low : constant Node_Id := Type_Low_Bound (Index_Typ); 1051 Index_Typ_High : constant Node_Id := Type_High_Bound (Index_Typ); 1052 -- The type of the index corresponding to the array sub-aggregate 1053 -- along with its low and upper bounds 1054 1055 Index_Base : constant Entity_Id := Base_Type (Index_Typ); 1056 Index_Base_Low : constant Node_Id := Type_Low_Bound (Index_Base); 1057 Index_Base_High : constant Node_Id := Type_High_Bound (Index_Base); 1058 -- ditto for the base type 1059 1060 function Add (Val : Uint; To : Node_Id) return Node_Id; 1061 -- Creates a new expression node where Val is added to expression To. 1062 -- Tries to constant fold whenever possible. To must be an already 1063 -- analyzed expression. 1064 1065 procedure Check_Bound (BH : Node_Id; AH : in out Node_Id); 1066 -- Checks that AH (the upper bound of an array aggregate) is <= BH 1067 -- (the upper bound of the index base type). If the check fails a 1068 -- warning is emitted, the Raises_Constraint_Error Flag of N is set, 1069 -- and AH is replaced with a duplicate of BH. 1070 1071 procedure Check_Bounds (L, H : Node_Id; AL, AH : Node_Id); 1072 -- Checks that range AL .. AH is compatible with range L .. H. Emits a 1073 -- warning if not and sets the Raises_Constraint_Error Flag in N. 1074 1075 procedure Check_Length (L, H : Node_Id; Len : Uint); 1076 -- Checks that range L .. H contains at least Len elements. Emits a 1077 -- warning if not and sets the Raises_Constraint_Error Flag in N. 1078 1079 function Dynamic_Or_Null_Range (L, H : Node_Id) return Boolean; 1080 -- Returns True if range L .. H is dynamic or null. 1081 1082 procedure Get (Value : out Uint; From : Node_Id; OK : out Boolean); 1083 -- Given expression node From, this routine sets OK to False if it 1084 -- cannot statically evaluate From. Otherwise it stores this static 1085 -- value into Value. 1086 1087 function Resolve_Aggr_Expr 1088 (Expr : Node_Id; 1089 Single_Elmt : Boolean) 1090 return Boolean; 1091 -- Resolves aggregate expression Expr. Returs False if resolution 1092 -- fails. If Single_Elmt is set to False, the expression Expr may be 1093 -- used to initialize several array aggregate elements (this can 1094 -- happen for discrete choices such as "L .. H => Expr" or the others 1095 -- choice). In this event we do not resolve Expr unless expansion is 1096 -- disabled. To know why, see the DELAYED COMPONENT RESOLUTION 1097 -- note above. 1098 1099 --------- 1100 -- Add -- 1101 --------- 1102 1103 function Add (Val : Uint; To : Node_Id) return Node_Id is 1104 Expr_Pos : Node_Id; 1105 Expr : Node_Id; 1106 To_Pos : Node_Id; 1107 1108 begin 1109 if Raises_Constraint_Error (To) then 1110 return To; 1111 end if; 1112 1113 -- First test if we can do constant folding 1114 1115 if Compile_Time_Known_Value (To) 1116 or else Nkind (To) = N_Integer_Literal 1117 then 1118 Expr_Pos := Make_Integer_Literal (Loc, Expr_Value (To) + Val); 1119 Set_Is_Static_Expression (Expr_Pos); 1120 Set_Etype (Expr_Pos, Etype (To)); 1121 Set_Analyzed (Expr_Pos, Analyzed (To)); 1122 1123 if not Is_Enumeration_Type (Index_Typ) then 1124 Expr := Expr_Pos; 1125 1126 -- If we are dealing with enumeration return 1127 -- Index_Typ'Val (Expr_Pos) 1128 1129 else 1130 Expr := 1131 Make_Attribute_Reference 1132 (Loc, 1133 Prefix => New_Reference_To (Index_Typ, Loc), 1134 Attribute_Name => Name_Val, 1135 Expressions => New_List (Expr_Pos)); 1136 end if; 1137 1138 return Expr; 1139 end if; 1140 1141 -- If we are here no constant folding possible 1142 1143 if not Is_Enumeration_Type (Index_Base) then 1144 Expr := 1145 Make_Op_Add (Loc, 1146 Left_Opnd => Duplicate_Subexpr (To), 1147 Right_Opnd => Make_Integer_Literal (Loc, Val)); 1148 1149 -- If we are dealing with enumeration return 1150 -- Index_Typ'Val (Index_Typ'Pos (To) + Val) 1151 1152 else 1153 To_Pos := 1154 Make_Attribute_Reference 1155 (Loc, 1156 Prefix => New_Reference_To (Index_Typ, Loc), 1157 Attribute_Name => Name_Pos, 1158 Expressions => New_List (Duplicate_Subexpr (To))); 1159 1160 Expr_Pos := 1161 Make_Op_Add (Loc, 1162 Left_Opnd => To_Pos, 1163 Right_Opnd => Make_Integer_Literal (Loc, Val)); 1164 1165 Expr := 1166 Make_Attribute_Reference 1167 (Loc, 1168 Prefix => New_Reference_To (Index_Typ, Loc), 1169 Attribute_Name => Name_Val, 1170 Expressions => New_List (Expr_Pos)); 1171 end if; 1172 1173 return Expr; 1174 end Add; 1175 1176 ----------------- 1177 -- Check_Bound -- 1178 ----------------- 1179 1180 procedure Check_Bound (BH : Node_Id; AH : in out Node_Id) is 1181 Val_BH : Uint; 1182 Val_AH : Uint; 1183 1184 OK_BH : Boolean; 1185 OK_AH : Boolean; 1186 1187 begin 1188 Get (Value => Val_BH, From => BH, OK => OK_BH); 1189 Get (Value => Val_AH, From => AH, OK => OK_AH); 1190 1191 if OK_BH and then OK_AH and then Val_BH < Val_AH then 1192 Set_Raises_Constraint_Error (N); 1193 Error_Msg_N ("upper bound out of range?", AH); 1194 Error_Msg_N ("Constraint_Error will be raised at run-time?", AH); 1195 1196 -- You need to set AH to BH or else in the case of enumerations 1197 -- indices we will not be able to resolve the aggregate bounds. 1198 1199 AH := Duplicate_Subexpr (BH); 1200 end if; 1201 end Check_Bound; 1202 1203 ------------------ 1204 -- Check_Bounds -- 1205 ------------------ 1206 1207 procedure Check_Bounds (L, H : Node_Id; AL, AH : Node_Id) is 1208 Val_L : Uint; 1209 Val_H : Uint; 1210 Val_AL : Uint; 1211 Val_AH : Uint; 1212 1213 OK_L : Boolean; 1214 OK_H : Boolean; 1215 OK_AL : Boolean; 1216 OK_AH : Boolean; 1217 1218 begin 1219 if Raises_Constraint_Error (N) 1220 or else Dynamic_Or_Null_Range (AL, AH) 1221 then 1222 return; 1223 end if; 1224 1225 Get (Value => Val_L, From => L, OK => OK_L); 1226 Get (Value => Val_H, From => H, OK => OK_H); 1227 1228 Get (Value => Val_AL, From => AL, OK => OK_AL); 1229 Get (Value => Val_AH, From => AH, OK => OK_AH); 1230 1231 if OK_L and then Val_L > Val_AL then 1232 Set_Raises_Constraint_Error (N); 1233 Error_Msg_N ("lower bound of aggregate out of range?", N); 1234 Error_Msg_N ("\Constraint_Error will be raised at run-time?", N); 1235 end if; 1236 1237 if OK_H and then Val_H < Val_AH then 1238 Set_Raises_Constraint_Error (N); 1239 Error_Msg_N ("upper bound of aggregate out of range?", N); 1240 Error_Msg_N ("\Constraint_Error will be raised at run-time?", N); 1241 end if; 1242 end Check_Bounds; 1243 1244 ------------------ 1245 -- Check_Length -- 1246 ------------------ 1247 1248 procedure Check_Length (L, H : Node_Id; Len : Uint) is 1249 Val_L : Uint; 1250 Val_H : Uint; 1251 1252 OK_L : Boolean; 1253 OK_H : Boolean; 1254 1255 Range_Len : Uint; 1256 1257 begin 1258 if Raises_Constraint_Error (N) then 1259 return; 1260 end if; 1261 1262 Get (Value => Val_L, From => L, OK => OK_L); 1263 Get (Value => Val_H, From => H, OK => OK_H); 1264 1265 if not OK_L or else not OK_H then 1266 return; 1267 end if; 1268 1269 -- If null range length is zero 1270 1271 if Val_L > Val_H then 1272 Range_Len := Uint_0; 1273 else 1274 Range_Len := Val_H - Val_L + 1; 1275 end if; 1276 1277 if Range_Len < Len then 1278 Set_Raises_Constraint_Error (N); 1279 Error_Msg_N ("Too many elements?", N); 1280 Error_Msg_N ("Constraint_Error will be raised at run-time?", N); 1281 end if; 1282 end Check_Length; 1283 1284 --------------------------- 1285 -- Dynamic_Or_Null_Range -- 1286 --------------------------- 1287 1288 function Dynamic_Or_Null_Range (L, H : Node_Id) return Boolean is 1289 Val_L : Uint; 1290 Val_H : Uint; 1291 1292 OK_L : Boolean; 1293 OK_H : Boolean; 1294 1295 begin 1296 Get (Value => Val_L, From => L, OK => OK_L); 1297 Get (Value => Val_H, From => H, OK => OK_H); 1298 1299 return not OK_L or else not OK_H 1300 or else not Is_OK_Static_Expression (L) 1301 or else not Is_OK_Static_Expression (H) 1302 or else Val_L > Val_H; 1303 end Dynamic_Or_Null_Range; 1304 1305 --------- 1306 -- Get -- 1307 --------- 1308 1309 procedure Get (Value : out Uint; From : Node_Id; OK : out Boolean) is 1310 begin 1311 OK := True; 1312 1313 if Compile_Time_Known_Value (From) then 1314 Value := Expr_Value (From); 1315 1316 -- If expression From is something like Some_Type'Val (10) then 1317 -- Value = 10 1318 1319 elsif Nkind (From) = N_Attribute_Reference 1320 and then Attribute_Name (From) = Name_Val 1321 and then Compile_Time_Known_Value (First (Expressions (From))) 1322 then 1323 Value := Expr_Value (First (Expressions (From))); 1324 1325 else 1326 Value := Uint_0; 1327 OK := False; 1328 end if; 1329 end Get; 1330 1331 ----------------------- 1332 -- Resolve_Aggr_Expr -- 1333 ----------------------- 1334 1335 function Resolve_Aggr_Expr 1336 (Expr : Node_Id; 1337 Single_Elmt : Boolean) 1338 return Boolean 1339 is 1340 Nxt_Ind : constant Node_Id := Next_Index (Index); 1341 Nxt_Ind_Constr : constant Node_Id := Next_Index (Index_Constr); 1342 -- Index is the current index corresponding to the expresion. 1343 1344 Resolution_OK : Boolean := True; 1345 -- Set to False if resolution of the expression failed. 1346 1347 begin 1348 -- If the array type against which we are resolving the aggregate 1349 -- has several dimensions, the expressions nested inside the 1350 -- aggregate must be further aggregates (or strings). 1351 1352 if Present (Nxt_Ind) then 1353 if Nkind (Expr) /= N_Aggregate then 1354 1355 -- A string literal can appear where a one-dimensional array 1356 -- of characters is expected. If the literal looks like an 1357 -- operator, it is still an operator symbol, which will be 1358 -- transformed into a string when analyzed. 1359 1360 if Is_Character_Type (Component_Typ) 1361 and then No (Next_Index (Nxt_Ind)) 1362 and then (Nkind (Expr) = N_String_Literal 1363 or else Nkind (Expr) = N_Operator_Symbol) 1364 then 1365 -- A string literal used in a multidimensional array 1366 -- aggregate in place of the final one-dimensional 1367 -- aggregate must not be enclosed in parentheses. 1368 1369 if Paren_Count (Expr) /= 0 then 1370 Error_Msg_N ("No parenthesis allowed here", Expr); 1371 end if; 1372 1373 Make_String_Into_Aggregate (Expr); 1374 1375 else 1376 Error_Msg_N ("nested array aggregate expected", Expr); 1377 return Failure; 1378 end if; 1379 end if; 1380 1381 Resolution_OK := Resolve_Array_Aggregate 1382 (Expr, Nxt_Ind, Nxt_Ind_Constr, Component_Typ, Others_Allowed); 1383 1384 -- Do not resolve the expressions of discrete or others choices 1385 -- unless the expression covers a single component, or the expander 1386 -- is inactive. 1387 1388 elsif Single_Elmt 1389 or else not Expander_Active 1390 or else In_Default_Expression 1391 then 1392 Analyze_And_Resolve (Expr, Component_Typ); 1393 Check_Non_Static_Context (Expr); 1394 Aggregate_Constraint_Checks (Expr, Component_Typ); 1395 Check_Unset_Reference (Expr); 1396 end if; 1397 1398 if Raises_Constraint_Error (Expr) 1399 and then Nkind (Parent (Expr)) /= N_Component_Association 1400 then 1401 Set_Raises_Constraint_Error (N); 1402 end if; 1403 1404 return Resolution_OK; 1405 end Resolve_Aggr_Expr; 1406 1407 -- Variables local to Resolve_Array_Aggregate 1408 1409 Assoc : Node_Id; 1410 Choice : Node_Id; 1411 Expr : Node_Id; 1412 1413 Who_Cares : Node_Id; 1414 1415 Aggr_Low : Node_Id := Empty; 1416 Aggr_High : Node_Id := Empty; 1417 -- The actual low and high bounds of this sub-aggegate 1418 1419 Choices_Low : Node_Id := Empty; 1420 Choices_High : Node_Id := Empty; 1421 -- The lowest and highest discrete choices values for a named aggregate 1422 1423 Nb_Elements : Uint := Uint_0; 1424 -- The number of elements in a positional aggegate 1425 1426 Others_Present : Boolean := False; 1427 1428 Nb_Choices : Nat := 0; 1429 -- Contains the overall number of named choices in this sub-aggregate 1430 1431 Nb_Discrete_Choices : Nat := 0; 1432 -- The overall number of discrete choices (not counting others choice) 1433 1434 Case_Table_Size : Nat; 1435 -- Contains the size of the case table needed to sort aggregate choices 1436 1437 -- Start of processing for Resolve_Array_Aggregate 1438 1439 begin 1440 -- STEP 1: make sure the aggregate is correctly formatted 1441 1442 if Present (Component_Associations (N)) then 1443 Assoc := First (Component_Associations (N)); 1444 while Present (Assoc) loop 1445 Choice := First (Choices (Assoc)); 1446 while Present (Choice) loop 1447 if Nkind (Choice) = N_Others_Choice then 1448 Others_Present := True; 1449 1450 if Choice /= First (Choices (Assoc)) 1451 or else Present (Next (Choice)) 1452 then 1453 Error_Msg_N 1454 ("OTHERS must appear alone in a choice list", Choice); 1455 return Failure; 1456 end if; 1457 1458 if Present (Next (Assoc)) then 1459 Error_Msg_N 1460 ("OTHERS must appear last in an aggregate", Choice); 1461 return Failure; 1462 end if; 1463 1464 if Ada_83 1465 and then Assoc /= First (Component_Associations (N)) 1466 and then (Nkind (Parent (N)) = N_Assignment_Statement 1467 or else 1468 Nkind (Parent (N)) = N_Object_Declaration) 1469 then 1470 Error_Msg_N 1471 ("(Ada 83) illegal context for OTHERS choice", N); 1472 end if; 1473 end if; 1474 1475 Nb_Choices := Nb_Choices + 1; 1476 Next (Choice); 1477 end loop; 1478 1479 Next (Assoc); 1480 end loop; 1481 end if; 1482 1483 -- At this point we know that the others choice, if present, is by 1484 -- itself and appears last in the aggregate. Check if we have mixed 1485 -- positional and discrete associations (other than the others choice). 1486 1487 if Present (Expressions (N)) 1488 and then (Nb_Choices > 1 1489 or else (Nb_Choices = 1 and then not Others_Present)) 1490 then 1491 Error_Msg_N 1492 ("named association cannot follow positional association", 1493 First (Choices (First (Component_Associations (N))))); 1494 return Failure; 1495 end if; 1496 1497 -- Test for the validity of an others choice if present 1498 1499 if Others_Present and then not Others_Allowed then 1500 Error_Msg_N 1501 ("OTHERS choice not allowed here", 1502 First (Choices (First (Component_Associations (N))))); 1503 return Failure; 1504 end if; 1505 1506 -- Protect against cascaded errors 1507 1508 if Etype (Index_Typ) = Any_Type then 1509 return Failure; 1510 end if; 1511 1512 -- STEP 2: Process named components 1513 1514 if No (Expressions (N)) then 1515 1516 if Others_Present then 1517 Case_Table_Size := Nb_Choices - 1; 1518 else 1519 Case_Table_Size := Nb_Choices; 1520 end if; 1521 1522 Step_2 : declare 1523 Low : Node_Id; 1524 High : Node_Id; 1525 -- Denote the lowest and highest values in an aggregate choice 1526 1527 Hi_Val : Uint; 1528 Lo_Val : Uint; 1529 -- High end of one range and Low end of the next. Should be 1530 -- contiguous if there is no hole in the list of values. 1531 1532 Missing_Values : Boolean; 1533 -- Set True if missing index values 1534 1535 S_Low : Node_Id := Empty; 1536 S_High : Node_Id := Empty; 1537 -- if a choice in an aggregate is a subtype indication these 1538 -- denote the lowest and highest values of the subtype 1539 1540 Table : Case_Table_Type (1 .. Case_Table_Size); 1541 -- Used to sort all the different choice values 1542 1543 Single_Choice : Boolean; 1544 -- Set to true every time there is a single discrete choice in a 1545 -- discrete association 1546 1547 Prev_Nb_Discrete_Choices : Nat; 1548 -- Used to keep track of the number of discrete choices 1549 -- in the current association. 1550 1551 begin 1552 -- STEP 2 (A): Check discrete choices validity. 1553 1554 Assoc := First (Component_Associations (N)); 1555 while Present (Assoc) loop 1556 1557 Prev_Nb_Discrete_Choices := Nb_Discrete_Choices; 1558 Choice := First (Choices (Assoc)); 1559 loop 1560 Analyze (Choice); 1561 1562 if Nkind (Choice) = N_Others_Choice then 1563 Single_Choice := False; 1564 exit; 1565 1566 -- Test for subtype mark without constraint 1567 1568 elsif Is_Entity_Name (Choice) and then 1569 Is_Type (Entity (Choice)) 1570 then 1571 if Base_Type (Entity (Choice)) /= Index_Base then 1572 Error_Msg_N 1573 ("invalid subtype mark in aggregate choice", 1574 Choice); 1575 return Failure; 1576 end if; 1577 1578 elsif Nkind (Choice) = N_Subtype_Indication then 1579 Resolve_Discrete_Subtype_Indication (Choice, Index_Base); 1580 1581 -- Does the subtype indication evaluation raise CE ? 1582 1583 Get_Index_Bounds (Subtype_Mark (Choice), S_Low, S_High); 1584 Get_Index_Bounds (Choice, Low, High); 1585 Check_Bounds (S_Low, S_High, Low, High); 1586 1587 else -- Choice is a range or an expression 1588 Resolve (Choice, Index_Base); 1589 Check_Unset_Reference (Choice); 1590 Check_Non_Static_Context (Choice); 1591 1592 -- Do not range check a choice. This check is redundant 1593 -- since this test is already performed when we check 1594 -- that the bounds of the array aggregate are within 1595 -- range. 1596 1597 Set_Do_Range_Check (Choice, False); 1598 end if; 1599 1600 -- If we could not resolve the discrete choice stop here 1601 1602 if Etype (Choice) = Any_Type then 1603 return Failure; 1604 1605 -- If the discrete choice raises CE get its original bounds. 1606 1607 elsif Nkind (Choice) = N_Raise_Constraint_Error then 1608 Set_Raises_Constraint_Error (N); 1609 Get_Index_Bounds (Original_Node (Choice), Low, High); 1610 1611 -- Otherwise get its bounds as usual 1612 1613 else 1614 Get_Index_Bounds (Choice, Low, High); 1615 end if; 1616 1617 if (Dynamic_Or_Null_Range (Low, High) 1618 or else (Nkind (Choice) = N_Subtype_Indication 1619 and then 1620 Dynamic_Or_Null_Range (S_Low, S_High))) 1621 and then Nb_Choices /= 1 1622 then 1623 Error_Msg_N 1624 ("dynamic or empty choice in aggregate " & 1625 "must be the only choice", Choice); 1626 return Failure; 1627 end if; 1628 1629 Nb_Discrete_Choices := Nb_Discrete_Choices + 1; 1630 Table (Nb_Discrete_Choices).Choice_Lo := Low; 1631 Table (Nb_Discrete_Choices).Choice_Hi := High; 1632 1633 Next (Choice); 1634 1635 if No (Choice) then 1636 -- Check if we have a single discrete choice and whether 1637 -- this discrete choice specifies a single value. 1638 1639 Single_Choice := 1640 (Nb_Discrete_Choices = Prev_Nb_Discrete_Choices + 1) 1641 and then (Low = High); 1642 1643 exit; 1644 end if; 1645 end loop; 1646 1647 -- Ada0Y (AI-287): In case of default initialized component 1648 -- we delay the resolution to the expansion phase 1649 1650 if Box_Present (Assoc) then 1651 1652 -- Ada0Y (AI-287): In case of default initialization of a 1653 -- component the expander will generate calls to the 1654 -- corresponding initialization subprogram. 1655 1656 if Present (Base_Init_Proc (Etype (Component_Typ))) 1657 or else Has_Task (Base_Type (Component_Typ)) 1658 then 1659 null; 1660 else 1661 Error_Msg_N 1662 ("(Ada 0Y): no value supplied for this component", 1663 Assoc); 1664 end if; 1665 1666 elsif not Resolve_Aggr_Expr (Expression (Assoc), 1667 Single_Elmt => Single_Choice) 1668 then 1669 return Failure; 1670 end if; 1671 1672 Next (Assoc); 1673 end loop; 1674 1675 -- If aggregate contains more than one choice then these must be 1676 -- static. Sort them and check that they are contiguous 1677 1678 if Nb_Discrete_Choices > 1 then 1679 Sort_Case_Table (Table); 1680 Missing_Values := False; 1681 1682 Outer : for J in 1 .. Nb_Discrete_Choices - 1 loop 1683 if Expr_Value (Table (J).Choice_Hi) >= 1684 Expr_Value (Table (J + 1).Choice_Lo) 1685 then 1686 Error_Msg_N 1687 ("duplicate choice values in array aggregate", 1688 Table (J).Choice_Hi); 1689 return Failure; 1690 1691 elsif not Others_Present then 1692 1693 Hi_Val := Expr_Value (Table (J).Choice_Hi); 1694 Lo_Val := Expr_Value (Table (J + 1).Choice_Lo); 1695 1696 -- If missing values, output error messages 1697 1698 if Lo_Val - Hi_Val > 1 then 1699 1700 -- Header message if not first missing value 1701 1702 if not Missing_Values then 1703 Error_Msg_N 1704 ("missing index value(s) in array aggregate", N); 1705 Missing_Values := True; 1706 end if; 1707 1708 -- Output values of missing indexes 1709 1710 Lo_Val := Lo_Val - 1; 1711 Hi_Val := Hi_Val + 1; 1712 1713 -- Enumeration type case 1714 1715 if Is_Enumeration_Type (Index_Typ) then 1716 Error_Msg_Name_1 := 1717 Chars 1718 (Get_Enum_Lit_From_Pos 1719 (Index_Typ, Hi_Val, Loc)); 1720 1721 if Lo_Val = Hi_Val then 1722 Error_Msg_N ("\ %", N); 1723 else 1724 Error_Msg_Name_2 := 1725 Chars 1726 (Get_Enum_Lit_From_Pos 1727 (Index_Typ, Lo_Val, Loc)); 1728 Error_Msg_N ("\ % .. %", N); 1729 end if; 1730 1731 -- Integer types case 1732 1733 else 1734 Error_Msg_Uint_1 := Hi_Val; 1735 1736 if Lo_Val = Hi_Val then 1737 Error_Msg_N ("\ ^", N); 1738 else 1739 Error_Msg_Uint_2 := Lo_Val; 1740 Error_Msg_N ("\ ^ .. ^", N); 1741 end if; 1742 end if; 1743 end if; 1744 end if; 1745 end loop Outer; 1746 1747 if Missing_Values then 1748 Set_Etype (N, Any_Composite); 1749 return Failure; 1750 end if; 1751 end if; 1752 1753 -- STEP 2 (B): Compute aggregate bounds and min/max choices values 1754 1755 if Nb_Discrete_Choices > 0 then 1756 Choices_Low := Table (1).Choice_Lo; 1757 Choices_High := Table (Nb_Discrete_Choices).Choice_Hi; 1758 end if; 1759 1760 if Others_Present then 1761 Get_Index_Bounds (Index_Constr, Aggr_Low, Aggr_High); 1762 1763 else 1764 Aggr_Low := Choices_Low; 1765 Aggr_High := Choices_High; 1766 end if; 1767 end Step_2; 1768 1769 -- STEP 3: Process positional components 1770 1771 else 1772 -- STEP 3 (A): Process positional elements 1773 1774 Expr := First (Expressions (N)); 1775 Nb_Elements := Uint_0; 1776 while Present (Expr) loop 1777 Nb_Elements := Nb_Elements + 1; 1778 1779 if not Resolve_Aggr_Expr (Expr, Single_Elmt => True) then 1780 return Failure; 1781 end if; 1782 1783 Next (Expr); 1784 end loop; 1785 1786 if Others_Present then 1787 Assoc := Last (Component_Associations (N)); 1788 1789 -- Ada0Y (AI-287): In case of default initialized component 1790 -- we delay the resolution to the expansion phase. 1791 1792 if Box_Present (Assoc) then 1793 1794 -- Ada0Y (AI-287): In case of default initialization of a 1795 -- component the expander will generate calls to the 1796 -- corresponding initialization subprogram. 1797 1798 if Present (Base_Init_Proc (Etype (Component_Typ))) then 1799 null; 1800 else 1801 Error_Msg_N 1802 ("(Ada 0Y): no value supplied for these components", 1803 Assoc); 1804 end if; 1805 1806 elsif not Resolve_Aggr_Expr (Expression (Assoc), 1807 Single_Elmt => False) 1808 then 1809 return Failure; 1810 end if; 1811 end if; 1812 1813 -- STEP 3 (B): Compute the aggregate bounds 1814 1815 if Others_Present then 1816 Get_Index_Bounds (Index_Constr, Aggr_Low, Aggr_High); 1817 1818 else 1819 if Others_Allowed then 1820 Get_Index_Bounds (Index_Constr, Aggr_Low, Who_Cares); 1821 else 1822 Aggr_Low := Index_Typ_Low; 1823 end if; 1824 1825 Aggr_High := Add (Nb_Elements - 1, To => Aggr_Low); 1826 Check_Bound (Index_Base_High, Aggr_High); 1827 end if; 1828 end if; 1829 1830 -- STEP 4: Perform static aggregate checks and save the bounds 1831 1832 -- Check (A) 1833 1834 Check_Bounds (Index_Typ_Low, Index_Typ_High, Aggr_Low, Aggr_High); 1835 Check_Bounds (Index_Base_Low, Index_Base_High, Aggr_Low, Aggr_High); 1836 1837 -- Check (B) 1838 1839 if Others_Present and then Nb_Discrete_Choices > 0 then 1840 Check_Bounds (Aggr_Low, Aggr_High, Choices_Low, Choices_High); 1841 Check_Bounds (Index_Typ_Low, Index_Typ_High, 1842 Choices_Low, Choices_High); 1843 Check_Bounds (Index_Base_Low, Index_Base_High, 1844 Choices_Low, Choices_High); 1845 1846 -- Check (C) 1847 1848 elsif Others_Present and then Nb_Elements > 0 then 1849 Check_Length (Aggr_Low, Aggr_High, Nb_Elements); 1850 Check_Length (Index_Typ_Low, Index_Typ_High, Nb_Elements); 1851 Check_Length (Index_Base_Low, Index_Base_High, Nb_Elements); 1852 1853 end if; 1854 1855 if Raises_Constraint_Error (Aggr_Low) 1856 or else Raises_Constraint_Error (Aggr_High) 1857 then 1858 Set_Raises_Constraint_Error (N); 1859 end if; 1860 1861 Aggr_Low := Duplicate_Subexpr (Aggr_Low); 1862 1863 -- Do not duplicate Aggr_High if Aggr_High = Aggr_Low + Nb_Elements 1864 -- since the addition node returned by Add is not yet analyzed. Attach 1865 -- to tree and analyze first. Reset analyzed flag to insure it will get 1866 -- analyzed when it is a literal bound whose type must be properly 1867 -- set. 1868 1869 if Others_Present or else Nb_Discrete_Choices > 0 then 1870 Aggr_High := Duplicate_Subexpr (Aggr_High); 1871 1872 if Etype (Aggr_High) = Universal_Integer then 1873 Set_Analyzed (Aggr_High, False); 1874 end if; 1875 end if; 1876 1877 Set_Aggregate_Bounds 1878 (N, Make_Range (Loc, Low_Bound => Aggr_Low, High_Bound => Aggr_High)); 1879 1880 -- The bounds may contain expressions that must be inserted upwards. 1881 -- Attach them fully to the tree. After analysis, remove side effects 1882 -- from upper bound, if still needed. 1883 1884 Set_Parent (Aggregate_Bounds (N), N); 1885 Analyze_And_Resolve (Aggregate_Bounds (N), Index_Typ); 1886 Check_Unset_Reference (Aggregate_Bounds (N)); 1887 1888 if not Others_Present and then Nb_Discrete_Choices = 0 then 1889 Set_High_Bound (Aggregate_Bounds (N), 1890 Duplicate_Subexpr (High_Bound (Aggregate_Bounds (N)))); 1891 end if; 1892 1893 return Success; 1894 end Resolve_Array_Aggregate; 1895 1896 --------------------------------- 1897 -- Resolve_Extension_Aggregate -- 1898 --------------------------------- 1899 1900 -- There are two cases to consider: 1901 1902 -- a) If the ancestor part is a type mark, the components needed are 1903 -- the difference between the components of the expected type and the 1904 -- components of the given type mark. 1905 1906 -- b) If the ancestor part is an expression, it must be unambiguous, 1907 -- and once we have its type we can also compute the needed components 1908 -- as in the previous case. In both cases, if the ancestor type is not 1909 -- the immediate ancestor, we have to build this ancestor recursively. 1910 1911 -- In both cases discriminants of the ancestor type do not play a 1912 -- role in the resolution of the needed components, because inherited 1913 -- discriminants cannot be used in a type extension. As a result we can 1914 -- compute independently the list of components of the ancestor type and 1915 -- of the expected type. 1916 1917 procedure Resolve_Extension_Aggregate (N : Node_Id; Typ : Entity_Id) is 1918 A : constant Node_Id := Ancestor_Part (N); 1919 A_Type : Entity_Id; 1920 I : Interp_Index; 1921 It : Interp; 1922 1923 function Valid_Ancestor_Type return Boolean; 1924 -- Verify that the type of the ancestor part is a non-private ancestor 1925 -- of the expected type. 1926 1927 ------------------------- 1928 -- Valid_Ancestor_Type -- 1929 ------------------------- 1930 1931 function Valid_Ancestor_Type return Boolean is 1932 Imm_Type : Entity_Id; 1933 1934 begin 1935 Imm_Type := Base_Type (Typ); 1936 while Is_Derived_Type (Imm_Type) 1937 and then Etype (Imm_Type) /= Base_Type (A_Type) 1938 loop 1939 Imm_Type := Etype (Base_Type (Imm_Type)); 1940 end loop; 1941 1942 if Etype (Imm_Type) /= Base_Type (A_Type) then 1943 Error_Msg_NE ("expect ancestor type of &", A, Typ); 1944 return False; 1945 else 1946 return True; 1947 end if; 1948 end Valid_Ancestor_Type; 1949 1950 -- Start of processing for Resolve_Extension_Aggregate 1951 1952 begin 1953 Analyze (A); 1954 1955 if not Is_Tagged_Type (Typ) then 1956 Error_Msg_N ("type of extension aggregate must be tagged", N); 1957 return; 1958 1959 elsif Is_Limited_Type (Typ) then 1960 1961 -- Ada0Y (AI-287): Limited aggregates are allowed 1962 1963 if Extensions_Allowed then 1964 null; 1965 else 1966 Error_Msg_N ("aggregate type cannot be limited", N); 1967 Explain_Limited_Type (Typ, N); 1968 return; 1969 end if; 1970 1971 elsif Is_Class_Wide_Type (Typ) then 1972 Error_Msg_N ("aggregate cannot be of a class-wide type", N); 1973 return; 1974 end if; 1975 1976 if Is_Entity_Name (A) 1977 and then Is_Type (Entity (A)) 1978 then 1979 A_Type := Get_Full_View (Entity (A)); 1980 1981 if Valid_Ancestor_Type then 1982 Set_Entity (A, A_Type); 1983 Set_Etype (A, A_Type); 1984 1985 Validate_Ancestor_Part (N); 1986 Resolve_Record_Aggregate (N, Typ); 1987 end if; 1988 1989 elsif Nkind (A) /= N_Aggregate then 1990 if Is_Overloaded (A) then 1991 A_Type := Any_Type; 1992 Get_First_Interp (A, I, It); 1993 1994 while Present (It.Typ) loop 1995 1996 if Is_Tagged_Type (It.Typ) 1997 and then not Is_Limited_Type (It.Typ) 1998 then 1999 if A_Type /= Any_Type then 2000 Error_Msg_N ("cannot resolve expression", A); 2001 return; 2002 else 2003 A_Type := It.Typ; 2004 end if; 2005 end if; 2006 2007 Get_Next_Interp (I, It); 2008 end loop; 2009 2010 if A_Type = Any_Type then 2011 Error_Msg_N 2012 ("ancestor part must be non-limited tagged type", A); 2013 return; 2014 end if; 2015 2016 else 2017 A_Type := Etype (A); 2018 end if; 2019 2020 if Valid_Ancestor_Type then 2021 Resolve (A, A_Type); 2022 Check_Unset_Reference (A); 2023 Check_Non_Static_Context (A); 2024 2025 if Is_Class_Wide_Type (Etype (A)) 2026 and then Nkind (Original_Node (A)) = N_Function_Call 2027 then 2028 -- If the ancestor part is a dispatching call, it appears 2029 -- statically to be a legal ancestor, but it yields any 2030 -- member of the class, and it is not possible to determine 2031 -- whether it is an ancestor of the extension aggregate (much 2032 -- less which ancestor). It is not possible to determine the 2033 -- required components of the extension part. 2034 2035 Error_Msg_N ("ancestor part must be statically tagged", A); 2036 else 2037 Resolve_Record_Aggregate (N, Typ); 2038 end if; 2039 end if; 2040 2041 else 2042 Error_Msg_N (" No unique type for this aggregate", A); 2043 end if; 2044 end Resolve_Extension_Aggregate; 2045 2046 ------------------------------ 2047 -- Resolve_Record_Aggregate -- 2048 ------------------------------ 2049 2050 procedure Resolve_Record_Aggregate (N : Node_Id; Typ : Entity_Id) is 2051 New_Assoc_List : constant List_Id := New_List; 2052 New_Assoc : Node_Id; 2053 -- New_Assoc_List is the newly built list of N_Component_Association 2054 -- nodes. New_Assoc is one such N_Component_Association node in it. 2055 -- Please note that while Assoc and New_Assoc contain the same 2056 -- kind of nodes, they are used to iterate over two different 2057 -- N_Component_Association lists. 2058 2059 Others_Etype : Entity_Id := Empty; 2060 -- This variable is used to save the Etype of the last record component 2061 -- that takes its value from the others choice. Its purpose is: 2062 -- 2063 -- (a) make sure the others choice is useful 2064 -- 2065 -- (b) make sure the type of all the components whose value is 2066 -- subsumed by the others choice are the same. 2067 -- 2068 -- This variable is updated as a side effect of function Get_Value 2069 2070 Mbox_Present : Boolean := False; 2071 Others_Mbox : Boolean := False; 2072 -- Ada0Y (AI-287): Variables used in case of default initialization to 2073 -- provide a functionality similar to Others_Etype. Mbox_Present 2074 -- indicates that the component takes its default initialization; 2075 -- Others_Mbox indicates that at least one component takes its default 2076 -- initialization. Similar to Others_Etype, they are also updated as a 2077 -- side effect of function Get_Value. 2078 2079 procedure Add_Association 2080 (Component : Entity_Id; 2081 Expr : Node_Id; 2082 Box_Present : Boolean := False); 2083 -- Builds a new N_Component_Association node which associates 2084 -- Component to expression Expr and adds it to the new association 2085 -- list New_Assoc_List being built. 2086 2087 function Discr_Present (Discr : Entity_Id) return Boolean; 2088 -- If aggregate N is a regular aggregate this routine will return True. 2089 -- Otherwise, if N is an extension aggregate, Discr is a discriminant 2090 -- whose value may already have been specified by N's ancestor part, 2091 -- this routine checks whether this is indeed the case and if so 2092 -- returns False, signaling that no value for Discr should appear in the 2093 -- N's aggregate part. Also, in this case, the routine appends to 2094 -- New_Assoc_List Discr the discriminant value specified in the ancestor 2095 -- part. 2096 2097 function Get_Value 2098 (Compon : Node_Id; 2099 From : List_Id; 2100 Consider_Others_Choice : Boolean := False) 2101 return Node_Id; 2102 -- Given a record component stored in parameter Compon, the 2103 -- following function returns its value as it appears in the list 2104 -- From, which is a list of N_Component_Association nodes. If no 2105 -- component association has a choice for the searched component, 2106 -- the value provided by the others choice is returned, if there 2107 -- is one and Consider_Others_Choice is set to true. Otherwise 2108 -- Empty is returned. If there is more than one component association 2109 -- giving a value for the searched record component, an error message 2110 -- is emitted and the first found value is returned. 2111 -- 2112 -- If Consider_Others_Choice is set and the returned expression comes 2113 -- from the others choice, then Others_Etype is set as a side effect. 2114 -- An error message is emitted if the components taking their value 2115 -- from the others choice do not have same type. 2116 2117 procedure Resolve_Aggr_Expr (Expr : Node_Id; Component : Node_Id); 2118 -- Analyzes and resolves expression Expr against the Etype of the 2119 -- Component. This routine also applies all appropriate checks to Expr. 2120 -- It finally saves a Expr in the newly created association list that 2121 -- will be attached to the final record aggregate. Note that if the 2122 -- Parent pointer of Expr is not set then Expr was produced with a 2123 -- New_Copy_Tree or some such. 2124 2125 --------------------- 2126 -- Add_Association -- 2127 --------------------- 2128 2129 procedure Add_Association 2130 (Component : Entity_Id; 2131 Expr : Node_Id; 2132 Box_Present : Boolean := False) 2133 is 2134 Choice_List : constant List_Id := New_List; 2135 New_Assoc : Node_Id; 2136 2137 begin 2138 Append (New_Occurrence_Of (Component, Sloc (Expr)), Choice_List); 2139 New_Assoc := 2140 Make_Component_Association (Sloc (Expr), 2141 Choices => Choice_List, 2142 Expression => Expr, 2143 Box_Present => Box_Present); 2144 Append (New_Assoc, New_Assoc_List); 2145 end Add_Association; 2146 2147 ------------------- 2148 -- Discr_Present -- 2149 ------------------- 2150 2151 function Discr_Present (Discr : Entity_Id) return Boolean is 2152 Regular_Aggr : constant Boolean := Nkind (N) /= N_Extension_Aggregate; 2153 2154 Loc : Source_Ptr; 2155 2156 Ancestor : Node_Id; 2157 Discr_Expr : Node_Id; 2158 2159 Ancestor_Typ : Entity_Id; 2160 Orig_Discr : Entity_Id; 2161 D : Entity_Id; 2162 D_Val : Elmt_Id := No_Elmt; -- stop junk warning 2163 2164 Ancestor_Is_Subtyp : Boolean; 2165 2166 begin 2167 if Regular_Aggr then 2168 return True; 2169 end if; 2170 2171 Ancestor := Ancestor_Part (N); 2172 Ancestor_Typ := Etype (Ancestor); 2173 Loc := Sloc (Ancestor); 2174 2175 Ancestor_Is_Subtyp := 2176 Is_Entity_Name (Ancestor) and then Is_Type (Entity (Ancestor)); 2177 2178 -- If the ancestor part has no discriminants clearly N's aggregate 2179 -- part must provide a value for Discr. 2180 2181 if not Has_Discriminants (Ancestor_Typ) then 2182 return True; 2183 2184 -- If the ancestor part is an unconstrained subtype mark then the 2185 -- Discr must be present in N's aggregate part. 2186 2187 elsif Ancestor_Is_Subtyp 2188 and then not Is_Constrained (Entity (Ancestor)) 2189 then 2190 return True; 2191 end if; 2192 2193 -- Now look to see if Discr was specified in the ancestor part. 2194 2195 Orig_Discr := Original_Record_Component (Discr); 2196 D := First_Discriminant (Ancestor_Typ); 2197 2198 if Ancestor_Is_Subtyp then 2199 D_Val := First_Elmt (Discriminant_Constraint (Entity (Ancestor))); 2200 end if; 2201 2202 while Present (D) loop 2203 -- If Ancestor has already specified Disc value than 2204 -- insert its value in the final aggregate. 2205 2206 if Original_Record_Component (D) = Orig_Discr then 2207 if Ancestor_Is_Subtyp then 2208 Discr_Expr := New_Copy_Tree (Node (D_Val)); 2209 else 2210 Discr_Expr := 2211 Make_Selected_Component (Loc, 2212 Prefix => Duplicate_Subexpr (Ancestor), 2213 Selector_Name => New_Occurrence_Of (Discr, Loc)); 2214 end if; 2215 2216 Resolve_Aggr_Expr (Discr_Expr, Discr); 2217 return False; 2218 end if; 2219 2220 Next_Discriminant (D); 2221 2222 if Ancestor_Is_Subtyp then 2223 Next_Elmt (D_Val); 2224 end if; 2225 end loop; 2226 2227 return True; 2228 end Discr_Present; 2229 2230 --------------- 2231 -- Get_Value -- 2232 --------------- 2233 2234 function Get_Value 2235 (Compon : Node_Id; 2236 From : List_Id; 2237 Consider_Others_Choice : Boolean := False) 2238 return Node_Id 2239 is 2240 Assoc : Node_Id; 2241 Expr : Node_Id := Empty; 2242 Selector_Name : Node_Id; 2243 2244 procedure Check_Non_Limited_Type; 2245 -- Relax check to allow the default initialization of limited types. 2246 -- For example: 2247 -- record 2248 -- C : Lim := (..., others => <>); 2249 -- end record; 2250 2251 ---------------------------- 2252 -- Check_Non_Limited_Type -- 2253 ---------------------------- 2254 2255 procedure Check_Non_Limited_Type is 2256 begin 2257 if Is_Limited_Type (Etype (Compon)) 2258 and then Comes_From_Source (Compon) 2259 and then not In_Instance_Body 2260 then 2261 -- Ada0Y (AI-287): Limited aggregates are allowed 2262 2263 if Extensions_Allowed 2264 and then Present (Expression (Assoc)) 2265 and then Nkind (Expression (Assoc)) = N_Aggregate 2266 then 2267 null; 2268 else 2269 Error_Msg_N 2270 ("initialization not allowed for limited types", N); 2271 Explain_Limited_Type (Etype (Compon), Compon); 2272 end if; 2273 2274 end if; 2275 end Check_Non_Limited_Type; 2276 2277 -- Start of processing for Get_Value 2278 2279 begin 2280 Mbox_Present := False; 2281 2282 if Present (From) then 2283 Assoc := First (From); 2284 else 2285 return Empty; 2286 end if; 2287 2288 while Present (Assoc) loop 2289 Selector_Name := First (Choices (Assoc)); 2290 while Present (Selector_Name) loop 2291 if Nkind (Selector_Name) = N_Others_Choice then 2292 if Consider_Others_Choice and then No (Expr) then 2293 2294 -- We need to duplicate the expression for each 2295 -- successive component covered by the others choice. 2296 -- This is redundant if the others_choice covers only 2297 -- one component (small optimization possible???), but 2298 -- indispensable otherwise, because each one must be 2299 -- expanded individually to preserve side-effects. 2300 2301 -- Ada0Y (AI-287): In case of default initialization of 2302 -- components, we duplicate the corresponding default 2303 -- expression (from the record type declaration). 2304 2305 if Box_Present (Assoc) then 2306 Others_Mbox := True; 2307 Mbox_Present := True; 2308 2309 if Expander_Active then 2310 return New_Copy_Tree (Expression (Parent (Compon))); 2311 else 2312 return Expression (Parent (Compon)); 2313 end if; 2314 2315 else 2316 Check_Non_Limited_Type; 2317 2318 if Present (Others_Etype) and then 2319 Base_Type (Others_Etype) /= Base_Type (Etype 2320 (Compon)) 2321 then 2322 Error_Msg_N ("components in OTHERS choice must " & 2323 "have same type", Selector_Name); 2324 end if; 2325 2326 Others_Etype := Etype (Compon); 2327 2328 if Expander_Active then 2329 return New_Copy_Tree (Expression (Assoc)); 2330 else 2331 return Expression (Assoc); 2332 end if; 2333 end if; 2334 end if; 2335 2336 elsif Chars (Compon) = Chars (Selector_Name) then 2337 if No (Expr) then 2338 2339 -- We need to duplicate the expression when several 2340 -- components are grouped together with a "|" choice. 2341 -- For instance "filed1 | filed2 => Expr" 2342 2343 if Box_Present (Assoc) then 2344 Mbox_Present := True; 2345 2346 -- Duplicate the default expression of the component 2347 -- from the record type declaration 2348 2349 if Present (Next (Selector_Name)) then 2350 Expr := New_Copy_Tree 2351 (Expression (Parent (Compon))); 2352 else 2353 Expr := Expression (Parent (Compon)); 2354 end if; 2355 2356 else 2357 Check_Non_Limited_Type; 2358 2359 if Present (Next (Selector_Name)) then 2360 Expr := New_Copy_Tree (Expression (Assoc)); 2361 else 2362 Expr := Expression (Assoc); 2363 end if; 2364 end if; 2365 2366 Generate_Reference (Compon, Selector_Name); 2367 2368 else 2369 Error_Msg_NE 2370 ("more than one value supplied for &", 2371 Selector_Name, Compon); 2372 2373 end if; 2374 end if; 2375 2376 Next (Selector_Name); 2377 end loop; 2378 2379 Next (Assoc); 2380 end loop; 2381 2382 return Expr; 2383 end Get_Value; 2384 2385 ----------------------- 2386 -- Resolve_Aggr_Expr -- 2387 ----------------------- 2388 2389 procedure Resolve_Aggr_Expr (Expr : Node_Id; Component : Node_Id) is 2390 New_C : Entity_Id := Component; 2391 Expr_Type : Entity_Id := Empty; 2392 2393 function Has_Expansion_Delayed (Expr : Node_Id) return Boolean; 2394 -- If the expression is an aggregate (possibly qualified) then its 2395 -- expansion is delayed until the enclosing aggregate is expanded 2396 -- into assignments. In that case, do not generate checks on the 2397 -- expression, because they will be generated later, and will other- 2398 -- wise force a copy (to remove side-effects) that would leave a 2399 -- dynamic-sized aggregate in the code, something that gigi cannot 2400 -- handle. 2401 2402 Relocate : Boolean; 2403 -- Set to True if the resolved Expr node needs to be relocated 2404 -- when attached to the newly created association list. This node 2405 -- need not be relocated if its parent pointer is not set. 2406 -- In fact in this case Expr is the output of a New_Copy_Tree call. 2407 -- if Relocate is True then we have analyzed the expression node 2408 -- in the original aggregate and hence it needs to be relocated 2409 -- when moved over the new association list. 2410 2411 function Has_Expansion_Delayed (Expr : Node_Id) return Boolean is 2412 Kind : constant Node_Kind := Nkind (Expr); 2413 2414 begin 2415 return ((Kind = N_Aggregate 2416 or else Kind = N_Extension_Aggregate) 2417 and then Present (Etype (Expr)) 2418 and then Is_Record_Type (Etype (Expr)) 2419 and then Expansion_Delayed (Expr)) 2420 2421 or else (Kind = N_Qualified_Expression 2422 and then Has_Expansion_Delayed (Expression (Expr))); 2423 end Has_Expansion_Delayed; 2424 2425 -- Start of processing for Resolve_Aggr_Expr 2426 2427 begin 2428 -- If the type of the component is elementary or the type of the 2429 -- aggregate does not contain discriminants, use the type of the 2430 -- component to resolve Expr. 2431 2432 if Is_Elementary_Type (Etype (Component)) 2433 or else not Has_Discriminants (Etype (N)) 2434 then 2435 Expr_Type := Etype (Component); 2436 2437 -- Otherwise we have to pick up the new type of the component from 2438 -- the new costrained subtype of the aggregate. In fact components 2439 -- which are of a composite type might be constrained by a 2440 -- discriminant, and we want to resolve Expr against the subtype were 2441 -- all discriminant occurrences are replaced with their actual value. 2442 2443 else 2444 New_C := First_Component (Etype (N)); 2445 while Present (New_C) loop 2446 if Chars (New_C) = Chars (Component) then 2447 Expr_Type := Etype (New_C); 2448 exit; 2449 end if; 2450 2451 Next_Component (New_C); 2452 end loop; 2453 2454 pragma Assert (Present (Expr_Type)); 2455 2456 -- For each range in an array type where a discriminant has been 2457 -- replaced with the constraint, check that this range is within 2458 -- the range of the base type. This checks is done in the 2459 -- init proc for regular objects, but has to be done here for 2460 -- aggregates since no init proc is called for them. 2461 2462 if Is_Array_Type (Expr_Type) then 2463 declare 2464 Index : Node_Id := First_Index (Expr_Type); 2465 -- Range of the current constrained index in the array. 2466 2467 Orig_Index : Node_Id := First_Index (Etype (Component)); 2468 -- Range corresponding to the range Index above in the 2469 -- original unconstrained record type. The bounds of this 2470 -- range may be governed by discriminants. 2471 2472 Unconstr_Index : Node_Id := First_Index (Etype (Expr_Type)); 2473 -- Range corresponding to the range Index above for the 2474 -- unconstrained array type. This range is needed to apply 2475 -- range checks. 2476 2477 begin 2478 while Present (Index) loop 2479 if Depends_On_Discriminant (Orig_Index) then 2480 Apply_Range_Check (Index, Etype (Unconstr_Index)); 2481 end if; 2482 2483 Next_Index (Index); 2484 Next_Index (Orig_Index); 2485 Next_Index (Unconstr_Index); 2486 end loop; 2487 end; 2488 end if; 2489 end if; 2490 2491 -- If the Parent pointer of Expr is not set, Expr is an expression 2492 -- duplicated by New_Tree_Copy (this happens for record aggregates 2493 -- that look like (Field1 | Filed2 => Expr) or (others => Expr)). 2494 -- Such a duplicated expression must be attached to the tree 2495 -- before analysis and resolution to enforce the rule that a tree 2496 -- fragment should never be analyzed or resolved unless it is 2497 -- attached to the current compilation unit. 2498 2499 if No (Parent (Expr)) then 2500 Set_Parent (Expr, N); 2501 Relocate := False; 2502 else 2503 Relocate := True; 2504 end if; 2505 2506 Analyze_And_Resolve (Expr, Expr_Type); 2507 Check_Non_Static_Context (Expr); 2508 Check_Unset_Reference (Expr); 2509 2510 if not Has_Expansion_Delayed (Expr) then 2511 Aggregate_Constraint_Checks (Expr, Expr_Type); 2512 end if; 2513 2514 if Raises_Constraint_Error (Expr) then 2515 Set_Raises_Constraint_Error (N); 2516 end if; 2517 2518 if Relocate then 2519 Add_Association (New_C, Relocate_Node (Expr)); 2520 else 2521 Add_Association (New_C, Expr); 2522 end if; 2523 end Resolve_Aggr_Expr; 2524 2525 -- Resolve_Record_Aggregate local variables 2526 2527 Assoc : Node_Id; 2528 -- N_Component_Association node belonging to the input aggregate N 2529 2530 Expr : Node_Id; 2531 Positional_Expr : Node_Id; 2532 Component : Entity_Id; 2533 Component_Elmt : Elmt_Id; 2534 2535 Components : constant Elist_Id := New_Elmt_List; 2536 -- Components is the list of the record components whose value must 2537 -- be provided in the aggregate. This list does include discriminants. 2538 2539 -- Start of processing for Resolve_Record_Aggregate 2540 2541 begin 2542 -- We may end up calling Duplicate_Subexpr on expressions that are 2543 -- attached to New_Assoc_List. For this reason we need to attach it 2544 -- to the tree by setting its parent pointer to N. This parent point 2545 -- will change in STEP 8 below. 2546 2547 Set_Parent (New_Assoc_List, N); 2548 2549 -- STEP 1: abstract type and null record verification 2550 2551 if Is_Abstract (Typ) then 2552 Error_Msg_N ("type of aggregate cannot be abstract", N); 2553 end if; 2554 2555 if No (First_Entity (Typ)) and then Null_Record_Present (N) then 2556 Set_Etype (N, Typ); 2557 return; 2558 2559 elsif Present (First_Entity (Typ)) 2560 and then Null_Record_Present (N) 2561 and then not Is_Tagged_Type (Typ) 2562 then 2563 Error_Msg_N ("record aggregate cannot be null", N); 2564 return; 2565 2566 elsif No (First_Entity (Typ)) then 2567 Error_Msg_N ("record aggregate must be null", N); 2568 return; 2569 end if; 2570 2571 -- STEP 2: Verify aggregate structure 2572 2573 Step_2 : declare 2574 Selector_Name : Node_Id; 2575 Bad_Aggregate : Boolean := False; 2576 2577 begin 2578 if Present (Component_Associations (N)) then 2579 Assoc := First (Component_Associations (N)); 2580 else 2581 Assoc := Empty; 2582 end if; 2583 2584 while Present (Assoc) loop 2585 Selector_Name := First (Choices (Assoc)); 2586 while Present (Selector_Name) loop 2587 if Nkind (Selector_Name) = N_Identifier then 2588 null; 2589 2590 elsif Nkind (Selector_Name) = N_Others_Choice then 2591 if Selector_Name /= First (Choices (Assoc)) 2592 or else Present (Next (Selector_Name)) 2593 then 2594 Error_Msg_N ("OTHERS must appear alone in a choice list", 2595 Selector_Name); 2596 return; 2597 2598 elsif Present (Next (Assoc)) then 2599 Error_Msg_N ("OTHERS must appear last in an aggregate", 2600 Selector_Name); 2601 return; 2602 end if; 2603 2604 else 2605 Error_Msg_N 2606 ("selector name should be identifier or OTHERS", 2607 Selector_Name); 2608 Bad_Aggregate := True; 2609 end if; 2610 2611 Next (Selector_Name); 2612 end loop; 2613 2614 Next (Assoc); 2615 end loop; 2616 2617 if Bad_Aggregate then 2618 return; 2619 end if; 2620 end Step_2; 2621 2622 -- STEP 3: Find discriminant Values 2623 2624 Step_3 : declare 2625 Discrim : Entity_Id; 2626 Missing_Discriminants : Boolean := False; 2627 2628 begin 2629 if Present (Expressions (N)) then 2630 Positional_Expr := First (Expressions (N)); 2631 else 2632 Positional_Expr := Empty; 2633 end if; 2634 2635 if Has_Discriminants (Typ) then 2636 Discrim := First_Discriminant (Typ); 2637 else 2638 Discrim := Empty; 2639 end if; 2640 2641 -- First find the discriminant values in the positional components 2642 2643 while Present (Discrim) and then Present (Positional_Expr) loop 2644 if Discr_Present (Discrim) then 2645 Resolve_Aggr_Expr (Positional_Expr, Discrim); 2646 Next (Positional_Expr); 2647 end if; 2648 2649 if Present (Get_Value (Discrim, Component_Associations (N))) then 2650 Error_Msg_NE 2651 ("more than one value supplied for discriminant&", 2652 N, Discrim); 2653 end if; 2654 2655 Next_Discriminant (Discrim); 2656 end loop; 2657 2658 -- Find remaining discriminant values, if any, among named components 2659 2660 while Present (Discrim) loop 2661 Expr := Get_Value (Discrim, Component_Associations (N), True); 2662 2663 if not Discr_Present (Discrim) then 2664 if Present (Expr) then 2665 Error_Msg_NE 2666 ("more than one value supplied for discriminant&", 2667 N, Discrim); 2668 end if; 2669 2670 elsif No (Expr) then 2671 Error_Msg_NE 2672 ("no value supplied for discriminant &", N, Discrim); 2673 Missing_Discriminants := True; 2674 2675 else 2676 Resolve_Aggr_Expr (Expr, Discrim); 2677 end if; 2678 2679 Next_Discriminant (Discrim); 2680 end loop; 2681 2682 if Missing_Discriminants then 2683 return; 2684 end if; 2685 2686 -- At this point and until the beginning of STEP 6, New_Assoc_List 2687 -- contains only the discriminants and their values. 2688 2689 end Step_3; 2690 2691 -- STEP 4: Set the Etype of the record aggregate 2692 2693 -- ??? This code is pretty much a copy of Sem_Ch3.Build_Subtype. That 2694 -- routine should really be exported in sem_util or some such and used 2695 -- in sem_ch3 and here rather than have a copy of the code which is a 2696 -- maintenance nightmare. 2697 2698 -- ??? Performace WARNING. The current implementation creates a new 2699 -- itype for all aggregates whose base type is discriminated. 2700 -- This means that for record aggregates nested inside an array 2701 -- aggregate we will create a new itype for each record aggregate 2702 -- if the array cmponent type has discriminants. For large aggregates 2703 -- this may be a problem. What should be done in this case is 2704 -- to reuse itypes as much as possible. 2705 2706 if Has_Discriminants (Typ) then 2707 Build_Constrained_Itype : declare 2708 Loc : constant Source_Ptr := Sloc (N); 2709 Indic : Node_Id; 2710 Subtyp_Decl : Node_Id; 2711 Def_Id : Entity_Id; 2712 2713 C : constant List_Id := New_List; 2714 2715 begin 2716 New_Assoc := First (New_Assoc_List); 2717 while Present (New_Assoc) loop 2718 Append (Duplicate_Subexpr (Expression (New_Assoc)), To => C); 2719 Next (New_Assoc); 2720 end loop; 2721 2722 Indic := 2723 Make_Subtype_Indication (Loc, 2724 Subtype_Mark => New_Occurrence_Of (Base_Type (Typ), Loc), 2725 Constraint => Make_Index_Or_Discriminant_Constraint (Loc, C)); 2726 2727 Def_Id := Create_Itype (Ekind (Typ), N); 2728 2729 Subtyp_Decl := 2730 Make_Subtype_Declaration (Loc, 2731 Defining_Identifier => Def_Id, 2732 Subtype_Indication => Indic); 2733 Set_Parent (Subtyp_Decl, Parent (N)); 2734 2735 -- Itypes must be analyzed with checks off (see itypes.ads). 2736 2737 Analyze (Subtyp_Decl, Suppress => All_Checks); 2738 2739 Set_Etype (N, Def_Id); 2740 Check_Static_Discriminated_Subtype 2741 (Def_Id, Expression (First (New_Assoc_List))); 2742 end Build_Constrained_Itype; 2743 2744 else 2745 Set_Etype (N, Typ); 2746 end if; 2747 2748 -- STEP 5: Get remaining components according to discriminant values 2749 2750 Step_5 : declare 2751 Record_Def : Node_Id; 2752 Parent_Typ : Entity_Id; 2753 Root_Typ : Entity_Id; 2754 Parent_Typ_List : Elist_Id; 2755 Parent_Elmt : Elmt_Id; 2756 Errors_Found : Boolean := False; 2757 Dnode : Node_Id; 2758 2759 begin 2760 if Is_Derived_Type (Typ) and then Is_Tagged_Type (Typ) then 2761 Parent_Typ_List := New_Elmt_List; 2762 2763 -- If this is an extension aggregate, the component list must 2764 -- include all components that are not in the given ancestor 2765 -- type. Otherwise, the component list must include components 2766 -- of all ancestors, starting with the root. 2767 2768 if Nkind (N) = N_Extension_Aggregate then 2769 Root_Typ := Base_Type (Etype (Ancestor_Part (N))); 2770 else 2771 Root_Typ := Root_Type (Typ); 2772 2773 if Nkind (Parent (Base_Type (Root_Typ))) 2774 = N_Private_Type_Declaration 2775 then 2776 Error_Msg_NE 2777 ("type of aggregate has private ancestor&!", 2778 N, Root_Typ); 2779 Error_Msg_N ("must use extension aggregate!", N); 2780 return; 2781 end if; 2782 2783 Dnode := Declaration_Node (Base_Type (Root_Typ)); 2784 2785 -- If we don't get a full declaration, then we have some 2786 -- error which will get signalled later so skip this part. 2787 -- Otherwise, gather components of root that apply to the 2788 -- aggregate type. We use the base type in case there is an 2789 -- applicable stored constraint that renames the discriminants 2790 -- of the root. 2791 2792 if Nkind (Dnode) = N_Full_Type_Declaration then 2793 Record_Def := Type_Definition (Dnode); 2794 Gather_Components (Base_Type (Typ), 2795 Component_List (Record_Def), 2796 Governed_By => New_Assoc_List, 2797 Into => Components, 2798 Report_Errors => Errors_Found); 2799 end if; 2800 end if; 2801 2802 Parent_Typ := Base_Type (Typ); 2803 while Parent_Typ /= Root_Typ loop 2804 2805 Prepend_Elmt (Parent_Typ, To => Parent_Typ_List); 2806 Parent_Typ := Etype (Parent_Typ); 2807 2808 if Nkind (Parent (Base_Type (Parent_Typ))) = 2809 N_Private_Type_Declaration 2810 or else Nkind (Parent (Base_Type (Parent_Typ))) = 2811 N_Private_Extension_Declaration 2812 then 2813 if Nkind (N) /= N_Extension_Aggregate then 2814 Error_Msg_NE 2815 ("type of aggregate has private ancestor&!", 2816 N, Parent_Typ); 2817 Error_Msg_N ("must use extension aggregate!", N); 2818 return; 2819 2820 elsif Parent_Typ /= Root_Typ then 2821 Error_Msg_NE 2822 ("ancestor part of aggregate must be private type&", 2823 Ancestor_Part (N), Parent_Typ); 2824 return; 2825 end if; 2826 end if; 2827 end loop; 2828 2829 -- Now collect components from all other ancestors. 2830 2831 Parent_Elmt := First_Elmt (Parent_Typ_List); 2832 while Present (Parent_Elmt) loop 2833 Parent_Typ := Node (Parent_Elmt); 2834 Record_Def := Type_Definition (Parent (Base_Type (Parent_Typ))); 2835 Gather_Components (Empty, 2836 Component_List (Record_Extension_Part (Record_Def)), 2837 Governed_By => New_Assoc_List, 2838 Into => Components, 2839 Report_Errors => Errors_Found); 2840 2841 Next_Elmt (Parent_Elmt); 2842 end loop; 2843 2844 else 2845 Record_Def := Type_Definition (Parent (Base_Type (Typ))); 2846 2847 if Null_Present (Record_Def) then 2848 null; 2849 else 2850 Gather_Components (Base_Type (Typ), 2851 Component_List (Record_Def), 2852 Governed_By => New_Assoc_List, 2853 Into => Components, 2854 Report_Errors => Errors_Found); 2855 end if; 2856 end if; 2857 2858 if Errors_Found then 2859 return; 2860 end if; 2861 end Step_5; 2862 2863 -- STEP 6: Find component Values 2864 2865 Component := Empty; 2866 Component_Elmt := First_Elmt (Components); 2867 2868 -- First scan the remaining positional associations in the aggregate. 2869 -- Remember that at this point Positional_Expr contains the current 2870 -- positional association if any is left after looking for discriminant 2871 -- values in step 3. 2872 2873 while Present (Positional_Expr) and then Present (Component_Elmt) loop 2874 Component := Node (Component_Elmt); 2875 Resolve_Aggr_Expr (Positional_Expr, Component); 2876 2877 if Present (Get_Value (Component, Component_Associations (N))) then 2878 Error_Msg_NE 2879 ("more than one value supplied for Component &", N, Component); 2880 end if; 2881 2882 Next (Positional_Expr); 2883 Next_Elmt (Component_Elmt); 2884 end loop; 2885 2886 if Present (Positional_Expr) then 2887 Error_Msg_N 2888 ("too many components for record aggregate", Positional_Expr); 2889 end if; 2890 2891 -- Now scan for the named arguments of the aggregate 2892 2893 while Present (Component_Elmt) loop 2894 Component := Node (Component_Elmt); 2895 Expr := Get_Value (Component, Component_Associations (N), True); 2896 2897 if Mbox_Present and then Is_Limited_Type (Etype (Component)) then 2898 2899 -- Ada0Y (AI-287): In case of default initialization of a limited 2900 -- component we pass the limited component to the expander. The 2901 -- expander will generate calls to the corresponding initiali- 2902 -- zation subprograms. 2903 2904 Add_Association 2905 (Component => Component, 2906 Expr => Empty, 2907 Box_Present => True); 2908 2909 elsif No (Expr) then 2910 Error_Msg_NE ("no value supplied for component &!", N, Component); 2911 else 2912 Resolve_Aggr_Expr (Expr, Component); 2913 end if; 2914 2915 Next_Elmt (Component_Elmt); 2916 end loop; 2917 2918 -- STEP 7: check for invalid components + check type in choice list 2919 2920 Step_7 : declare 2921 Selectr : Node_Id; 2922 -- Selector name 2923 2924 Typech : Entity_Id; 2925 -- Type of first component in choice list 2926 2927 begin 2928 if Present (Component_Associations (N)) then 2929 Assoc := First (Component_Associations (N)); 2930 else 2931 Assoc := Empty; 2932 end if; 2933 2934 Verification : while Present (Assoc) loop 2935 Selectr := First (Choices (Assoc)); 2936 Typech := Empty; 2937 2938 if Nkind (Selectr) = N_Others_Choice then 2939 2940 -- Ada0Y (AI-287): others choice may have expression or mbox 2941 2942 if No (Others_Etype) 2943 and then not Others_Mbox 2944 then 2945 Error_Msg_N 2946 ("OTHERS must represent at least one component", Selectr); 2947 end if; 2948 2949 exit Verification; 2950 end if; 2951 2952 while Present (Selectr) loop 2953 New_Assoc := First (New_Assoc_List); 2954 while Present (New_Assoc) loop 2955 Component := First (Choices (New_Assoc)); 2956 exit when Chars (Selectr) = Chars (Component); 2957 Next (New_Assoc); 2958 end loop; 2959 2960 -- If no association, this is not a legal component of 2961 -- of the type in question, except if this is an internal 2962 -- component supplied by a previous expansion. 2963 2964 if No (New_Assoc) then 2965 if Box_Present (Parent (Selectr)) then 2966 null; 2967 2968 elsif Chars (Selectr) /= Name_uTag 2969 and then Chars (Selectr) /= Name_uParent 2970 and then Chars (Selectr) /= Name_uController 2971 then 2972 if not Has_Discriminants (Typ) then 2973 Error_Msg_Node_2 := Typ; 2974 Error_Msg_N 2975 ("& is not a component of}", 2976 Selectr); 2977 else 2978 Error_Msg_N 2979 ("& is not a component of the aggregate subtype", 2980 Selectr); 2981 end if; 2982 2983 Check_Misspelled_Component (Components, Selectr); 2984 end if; 2985 2986 elsif No (Typech) then 2987 Typech := Base_Type (Etype (Component)); 2988 2989 elsif Typech /= Base_Type (Etype (Component)) then 2990 if not Box_Present (Parent (Selectr)) then 2991 Error_Msg_N 2992 ("components in choice list must have same type", 2993 Selectr); 2994 end if; 2995 end if; 2996 2997 Next (Selectr); 2998 end loop; 2999 3000 Next (Assoc); 3001 end loop Verification; 3002 end Step_7; 3003 3004 -- STEP 8: replace the original aggregate 3005 3006 Step_8 : declare 3007 New_Aggregate : constant Node_Id := New_Copy (N); 3008 3009 begin 3010 Set_Expressions (New_Aggregate, No_List); 3011 Set_Etype (New_Aggregate, Etype (N)); 3012 Set_Component_Associations (New_Aggregate, New_Assoc_List); 3013 3014 Rewrite (N, New_Aggregate); 3015 end Step_8; 3016 end Resolve_Record_Aggregate; 3017 3018 --------------------- 3019 -- Sort_Case_Table -- 3020 --------------------- 3021 3022 procedure Sort_Case_Table (Case_Table : in out Case_Table_Type) is 3023 L : constant Int := Case_Table'First; 3024 U : constant Int := Case_Table'Last; 3025 K : Int; 3026 J : Int; 3027 T : Case_Bounds; 3028 3029 begin 3030 K := L; 3031 3032 while K /= U loop 3033 T := Case_Table (K + 1); 3034 J := K + 1; 3035 3036 while J /= L 3037 and then Expr_Value (Case_Table (J - 1).Choice_Lo) > 3038 Expr_Value (T.Choice_Lo) 3039 loop 3040 Case_Table (J) := Case_Table (J - 1); 3041 J := J - 1; 3042 end loop; 3043 3044 Case_Table (J) := T; 3045 K := K + 1; 3046 end loop; 3047 end Sort_Case_Table; 3048 3049end Sem_Aggr; 3050