1------------------------------------------------------------------------------ 2-- -- 3-- GNAT COMPILER COMPONENTS -- 4-- -- 5-- P A R . U T I L -- 6-- -- 7-- B o d y -- 8-- -- 9-- Copyright (C) 1992-2013, Free Software Foundation, Inc. -- 10-- -- 11-- GNAT is free software; you can redistribute it and/or modify it under -- 12-- terms of the GNU General Public License as published by the Free Soft- -- 13-- ware Foundation; either version 3, or (at your option) any later ver- -- 14-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- 15-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- 16-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- 17-- for more details. You should have received a copy of the GNU General -- 18-- Public License distributed with GNAT; see file COPYING3. If not, go to -- 19-- http://www.gnu.org/licenses for a complete copy of the license. -- 20-- -- 21-- GNAT was originally developed by the GNAT team at New York University. -- 22-- Extensive contributions were provided by Ada Core Technologies Inc. -- 23-- -- 24------------------------------------------------------------------------------ 25 26with Csets; use Csets; 27with Namet.Sp; use Namet.Sp; 28with Stylesw; use Stylesw; 29with Uintp; use Uintp; 30with Warnsw; use Warnsw; 31 32with GNAT.Spelling_Checker; use GNAT.Spelling_Checker; 33 34separate (Par) 35package body Util is 36 37 --------------------- 38 -- Bad_Spelling_Of -- 39 --------------------- 40 41 function Bad_Spelling_Of (T : Token_Type) return Boolean is 42 Tname : constant String := Token_Type'Image (T); 43 -- Characters of token name 44 45 S : String (1 .. Tname'Last - 4); 46 -- Characters of token name folded to lower case, omitting TOK_ at start 47 48 M1 : String (1 .. 42) := "incorrect spelling of keyword ************"; 49 M2 : String (1 .. 44) := "illegal abbreviation of keyword ************"; 50 -- Buffers used to construct error message 51 52 P1 : constant := 30; 53 P2 : constant := 32; 54 -- Starting subscripts in M1, M2 for keyword name 55 56 SL : constant Natural := S'Length; 57 -- Length of expected token name excluding TOK_ at start 58 59 begin 60 if Token /= Tok_Identifier then 61 return False; 62 end if; 63 64 for J in S'Range loop 65 S (J) := Fold_Lower (Tname (J + 4)); 66 end loop; 67 68 Get_Name_String (Token_Name); 69 70 -- A special check for case of PROGRAM used for PROCEDURE 71 72 if T = Tok_Procedure 73 and then Name_Len = 7 74 and then Name_Buffer (1 .. 7) = "program" 75 then 76 Error_Msg_SC -- CODEFIX 77 ("PROCEDURE expected"); 78 Token := T; 79 return True; 80 81 -- A special check for an illegal abbreviation 82 83 elsif Name_Len < S'Length 84 and then Name_Len >= 4 85 and then Name_Buffer (1 .. Name_Len) = S (1 .. Name_Len) 86 then 87 for J in 1 .. S'Last loop 88 M2 (P2 + J - 1) := Fold_Upper (S (J)); 89 end loop; 90 91 Error_Msg_SC (M2 (1 .. P2 - 1 + S'Last)); 92 Token := T; 93 return True; 94 end if; 95 96 -- Now we go into the full circuit to check for a misspelling 97 98 -- Never consider something a misspelling if either the actual or 99 -- expected string is less than 3 characters (before this check we 100 -- used to consider i to be a misspelled if in some cases). 101 102 if SL < 3 or else Name_Len < 3 then 103 return False; 104 105 -- Special case: prefix matches, i.e. the leading characters of the 106 -- token that we have exactly match the required keyword. If there 107 -- are at least two characters left over, assume that we have a case 108 -- of two keywords joined together which should not be joined. 109 110 elsif Name_Len > SL + 1 111 and then S = Name_Buffer (1 .. SL) 112 then 113 Scan_Ptr := Token_Ptr + S'Length; 114 Error_Msg_S ("|missing space"); 115 Token := T; 116 return True; 117 end if; 118 119 if Is_Bad_Spelling_Of (Name_Buffer (1 .. Name_Len), S) then 120 for J in 1 .. S'Last loop 121 M1 (P1 + J - 1) := Fold_Upper (S (J)); 122 end loop; 123 124 Error_Msg_SC -- CODFIX 125 (M1 (1 .. P1 - 1 + S'Last)); 126 Token := T; 127 return True; 128 129 else 130 return False; 131 end if; 132 end Bad_Spelling_Of; 133 134 ---------------------- 135 -- Check_95_Keyword -- 136 ---------------------- 137 138 -- On entry, the caller has checked that current token is an identifier 139 -- whose name matches the name of the 95 keyword New_Tok. 140 141 procedure Check_95_Keyword (Token_95, Next : Token_Type) is 142 Scan_State : Saved_Scan_State; 143 144 begin 145 Save_Scan_State (Scan_State); -- at identifier/keyword 146 Scan; -- past identifier/keyword 147 148 if Token = Next then 149 Restore_Scan_State (Scan_State); -- to identifier 150 Error_Msg_Name_1 := Token_Name; 151 Error_Msg_SC ("(Ada 83) keyword* cannot be used!"); 152 Token := Token_95; 153 else 154 Restore_Scan_State (Scan_State); -- to identifier 155 end if; 156 end Check_95_Keyword; 157 158 ---------------------- 159 -- Check_Bad_Layout -- 160 ---------------------- 161 162 procedure Check_Bad_Layout is 163 begin 164 if RM_Column_Check and then Token_Is_At_Start_Of_Line 165 and then Start_Column <= Scope.Table (Scope.Last).Ecol 166 then 167 Error_Msg_BC -- CODEFIX 168 ("(style) incorrect layout"); 169 end if; 170 end Check_Bad_Layout; 171 172 -------------------------- 173 -- Check_Future_Keyword -- 174 -------------------------- 175 176 procedure Check_Future_Keyword is 177 begin 178 -- Ada 2005 (AI-284): Compiling in Ada 95 mode we warn that INTERFACE, 179 -- OVERRIDING, and SYNCHRONIZED are new reserved words. 180 181 if Ada_Version = Ada_95 182 and then Warn_On_Ada_2005_Compatibility 183 then 184 if Nam_In (Token_Name, Name_Overriding, Name_Synchronized) 185 or else (Token_Name = Name_Interface 186 and then Prev_Token /= Tok_Pragma) 187 then 188 Error_Msg_N ("& is a reserved word in Ada 2005?y?", Token_Node); 189 end if; 190 end if; 191 192 -- Similarly, warn about Ada 2012 reserved words 193 194 if Ada_Version in Ada_95 .. Ada_2005 195 and then Warn_On_Ada_2012_Compatibility 196 then 197 if Token_Name = Name_Some then 198 Error_Msg_N ("& is a reserved word in Ada 2012?y?", Token_Node); 199 end if; 200 end if; 201 202 -- Note: we deliberately do not emit these warnings when operating in 203 -- Ada 83 mode because in that case we assume the user is building 204 -- legacy code anyway and is not interested in updating Ada versions. 205 206 end Check_Future_Keyword; 207 208 -------------------------- 209 -- Check_Misspelling_Of -- 210 -------------------------- 211 212 procedure Check_Misspelling_Of (T : Token_Type) is 213 begin 214 if Bad_Spelling_Of (T) then 215 null; 216 end if; 217 end Check_Misspelling_Of; 218 219 ----------------------------- 220 -- Check_Simple_Expression -- 221 ----------------------------- 222 223 procedure Check_Simple_Expression (E : Node_Id) is 224 begin 225 if Expr_Form = EF_Non_Simple then 226 Error_Msg_N ("this expression must be parenthesized", E); 227 end if; 228 end Check_Simple_Expression; 229 230 --------------------------------------- 231 -- Check_Simple_Expression_In_Ada_83 -- 232 --------------------------------------- 233 234 procedure Check_Simple_Expression_In_Ada_83 (E : Node_Id) is 235 begin 236 if Expr_Form = EF_Non_Simple then 237 if Ada_Version = Ada_83 then 238 Error_Msg_N ("(Ada 83) this expression must be parenthesized!", E); 239 end if; 240 end if; 241 end Check_Simple_Expression_In_Ada_83; 242 243 ------------------------ 244 -- Check_Subtype_Mark -- 245 ------------------------ 246 247 function Check_Subtype_Mark (Mark : Node_Id) return Node_Id is 248 begin 249 if Nkind (Mark) = N_Identifier 250 or else Nkind (Mark) = N_Selected_Component 251 or else (Nkind (Mark) = N_Attribute_Reference 252 and then Is_Type_Attribute_Name (Attribute_Name (Mark))) 253 or else Mark = Error 254 then 255 return Mark; 256 else 257 Error_Msg ("subtype mark expected", Sloc (Mark)); 258 return Error; 259 end if; 260 end Check_Subtype_Mark; 261 262 ------------------- 263 -- Comma_Present -- 264 ------------------- 265 266 function Comma_Present return Boolean is 267 Scan_State : Saved_Scan_State; 268 Paren_Count : Nat; 269 270 begin 271 -- First check, if a comma is present, then a comma is present 272 273 if Token = Tok_Comma then 274 T_Comma; 275 return True; 276 277 -- If we have a right paren, then that is taken as ending the list 278 -- i.e. no comma is present. 279 280 elsif Token = Tok_Right_Paren then 281 return False; 282 283 -- If pragmas, then get rid of them and make a recursive call 284 -- to process what follows these pragmas. 285 286 elsif Token = Tok_Pragma then 287 P_Pragmas_Misplaced; 288 return Comma_Present; 289 290 -- At this stage we have an error, and the goal is to decide on whether 291 -- or not we should diagnose an error and report a (non-existent) 292 -- comma as being present, or simply to report no comma is present 293 294 -- If we are a semicolon, then the question is whether we have a missing 295 -- right paren, or whether the semicolon should have been a comma. To 296 -- guess the right answer, we scan ahead keeping track of the paren 297 -- level, looking for a clue that helps us make the right decision. 298 299 -- This approach is highly accurate in the single error case, and does 300 -- not make bad mistakes in the multiple error case (indeed we can't 301 -- really make a very bad decision at this point in any case). 302 303 elsif Token = Tok_Semicolon then 304 Save_Scan_State (Scan_State); 305 Scan; -- past semicolon 306 307 -- Check for being followed by identifier => which almost certainly 308 -- means we are still in a parameter list and the comma should have 309 -- been a semicolon (such a sequence could not follow a semicolon) 310 311 if Token = Tok_Identifier then 312 Scan; 313 314 if Token = Tok_Arrow then 315 goto Assume_Comma; 316 end if; 317 end if; 318 319 -- If that test didn't work, loop ahead looking for a comma or 320 -- semicolon at the same parenthesis level. Always remember that 321 -- we can't go badly wrong in an error situation like this. 322 323 Paren_Count := 0; 324 325 -- Here is the look ahead loop, Paren_Count tells us whether the 326 -- token we are looking at is at the same paren level as the 327 -- suspicious semicolon that we are trying to figure out. 328 329 loop 330 331 -- If we hit another semicolon or an end of file, and we have 332 -- not seen a right paren or another comma on the way, then 333 -- probably the semicolon did end the list. Indeed that is 334 -- certainly the only single error correction possible here. 335 336 if Token = Tok_Semicolon or else Token = Tok_EOF then 337 Restore_Scan_State (Scan_State); 338 return False; 339 340 -- A comma at the same paren level as the semicolon is a strong 341 -- indicator that the semicolon should have been a comma, indeed 342 -- again this is the only possible single error correction. 343 344 elsif Token = Tok_Comma then 345 exit when Paren_Count = 0; 346 347 -- A left paren just bumps the paren count 348 349 elsif Token = Tok_Left_Paren then 350 Paren_Count := Paren_Count + 1; 351 352 -- A right paren that is at the same paren level as the semicolon 353 -- also means that the only possible single error correction is 354 -- to assume that the semicolon should have been a comma. If we 355 -- are not at the same paren level, then adjust the paren level. 356 357 elsif Token = Tok_Right_Paren then 358 exit when Paren_Count = 0; 359 Paren_Count := Paren_Count - 1; 360 end if; 361 362 -- Keep going, we haven't made a decision yet 363 364 Scan; 365 end loop; 366 367 -- If we fall through the loop, it means that we found a terminating 368 -- right paren or another comma. In either case it is reasonable to 369 -- assume that the semicolon was really intended to be a comma. Also 370 -- come here for the identifier arrow case. 371 372 <<Assume_Comma>> 373 Restore_Scan_State (Scan_State); 374 Error_Msg_SC -- CODEFIX 375 ("|"";"" should be "","""); 376 Scan; -- past the semicolon 377 return True; 378 379 -- If we are not at semicolon or a right paren, then we base the 380 -- decision on whether or not the next token can be part of an 381 -- expression. If not, then decide that no comma is present (the 382 -- caller will eventually generate a missing right parent message) 383 384 elsif Token in Token_Class_Eterm then 385 return False; 386 387 -- Otherwise we assume a comma is present, even if none is present, 388 -- since the next token must be part of an expression, so if we were 389 -- at the end of the list, then there is more than one error present. 390 391 else 392 T_Comma; -- to give error 393 return True; 394 end if; 395 end Comma_Present; 396 397 ----------------------- 398 -- Discard_Junk_List -- 399 ----------------------- 400 401 procedure Discard_Junk_List (L : List_Id) is 402 pragma Warnings (Off, L); 403 begin 404 null; 405 end Discard_Junk_List; 406 407 ----------------------- 408 -- Discard_Junk_Node -- 409 ----------------------- 410 411 procedure Discard_Junk_Node (N : Node_Id) is 412 pragma Warnings (Off, N); 413 begin 414 null; 415 end Discard_Junk_Node; 416 417 ------------ 418 -- Ignore -- 419 ------------ 420 421 procedure Ignore (T : Token_Type) is 422 begin 423 while Token = T loop 424 if T = Tok_Comma then 425 Error_Msg_SC -- CODEFIX 426 ("|extra "","" ignored"); 427 428 elsif T = Tok_Left_Paren then 429 Error_Msg_SC -- CODEFIX 430 ("|extra ""("" ignored"); 431 432 -- Note: the following error used to be labeled as a non-serious 433 -- error like the other similar messages here (with a | at the start 434 -- of the message). But this caused some annoying cascaded errors 435 -- that were confusing, as shown by this example: 436 437 -- A : array (1 .. 9) of Integer := 438 -- ((1 .. 2) => 0, 439 -- 1 2 3 440 -- >>> positional aggregate cannot have one component 441 -- >>> named association cannot follow positional association 442 -- >>> extra ")" ignored 443 444 -- So we decided to label it as serious after all 445 446 elsif T = Tok_Right_Paren then 447 Error_Msg_SC -- CODEFIX 448 ("extra "")"" ignored"); 449 450 elsif T = Tok_Semicolon then 451 Error_Msg_SC -- CODEFIX 452 ("|extra "";"" ignored"); 453 454 elsif T = Tok_Colon then 455 Error_Msg_SC -- CODEFIX 456 ("|extra "":"" ignored"); 457 458 else 459 declare 460 Tname : constant String := Token_Type'Image (Token); 461 begin 462 Error_Msg_SC ("|extra " & Tname (5 .. Tname'Last) & "ignored"); 463 end; 464 end if; 465 466 Scan; -- Scan past ignored token 467 end loop; 468 end Ignore; 469 470 ---------------------------- 471 -- Is_Reserved_Identifier -- 472 ---------------------------- 473 474 function Is_Reserved_Identifier (C : Id_Check := None) return Boolean is 475 begin 476 if not Is_Reserved_Keyword (Token) then 477 return False; 478 479 else 480 declare 481 Ident_Casing : constant Casing_Type := 482 Identifier_Casing (Current_Source_File); 483 Key_Casing : constant Casing_Type := 484 Keyword_Casing (Current_Source_File); 485 486 begin 487 -- If the casing of identifiers and keywords is different in 488 -- this source file, and the casing of this token matches the 489 -- keyword casing, then we return False, since it is pretty 490 -- clearly intended to be a keyword. 491 492 if Ident_Casing = Unknown 493 or else Key_Casing = Unknown 494 or else Ident_Casing = Key_Casing 495 or else Determine_Token_Casing /= Key_Casing 496 then 497 return True; 498 499 -- Here we have a keyword written clearly with keyword casing. 500 -- In default mode, we would not be willing to consider this as 501 -- a reserved identifier, but if C is set, we may still accept it 502 503 elsif C /= None then 504 declare 505 Scan_State : Saved_Scan_State; 506 OK_Next_Tok : Boolean; 507 508 begin 509 Save_Scan_State (Scan_State); 510 Scan; 511 512 if Token_Is_At_Start_Of_Line then 513 return False; 514 end if; 515 516 case C is 517 when None => 518 raise Program_Error; 519 520 when C_Comma_Right_Paren => 521 OK_Next_Tok := 522 Token = Tok_Comma or else Token = Tok_Right_Paren; 523 524 when C_Comma_Colon => 525 OK_Next_Tok := 526 Token = Tok_Comma or else Token = Tok_Colon; 527 528 when C_Do => 529 OK_Next_Tok := 530 Token = Tok_Do; 531 532 when C_Dot => 533 OK_Next_Tok := 534 Token = Tok_Dot; 535 536 when C_Greater_Greater => 537 OK_Next_Tok := 538 Token = Tok_Greater_Greater; 539 540 when C_In => 541 OK_Next_Tok := 542 Token = Tok_In; 543 544 when C_Is => 545 OK_Next_Tok := 546 Token = Tok_Is; 547 548 when C_Left_Paren_Semicolon => 549 OK_Next_Tok := 550 Token = Tok_Left_Paren or else Token = Tok_Semicolon; 551 552 when C_Use => 553 OK_Next_Tok := 554 Token = Tok_Use; 555 556 when C_Vertical_Bar_Arrow => 557 OK_Next_Tok := 558 Token = Tok_Vertical_Bar or else Token = Tok_Arrow; 559 end case; 560 561 Restore_Scan_State (Scan_State); 562 563 if OK_Next_Tok then 564 return True; 565 end if; 566 end; 567 end if; 568 end; 569 end if; 570 571 -- If we fall through it is not a reserved identifier 572 573 return False; 574 end Is_Reserved_Identifier; 575 576 ---------------------- 577 -- Merge_Identifier -- 578 ---------------------- 579 580 procedure Merge_Identifier (Prev : Node_Id; Nxt : Token_Type) is 581 begin 582 if Token /= Tok_Identifier then 583 return; 584 end if; 585 586 declare 587 S : Saved_Scan_State; 588 T : Token_Type; 589 590 begin 591 Save_Scan_State (S); 592 Scan; 593 T := Token; 594 Restore_Scan_State (S); 595 596 if T /= Nxt then 597 return; 598 end if; 599 end; 600 601 -- Check exactly one space between identifiers 602 603 if Source (Token_Ptr - 1) /= ' ' 604 or else Int (Token_Ptr) /= 605 Int (Prev_Token_Ptr) + Length_Of_Name (Chars (Prev)) + 1 606 then 607 return; 608 end if; 609 610 -- Do the merge 611 612 Get_Name_String (Chars (Token_Node)); 613 614 declare 615 Buf : constant String (1 .. Name_Len) := 616 Name_Buffer (1 .. Name_Len); 617 618 begin 619 Get_Name_String (Chars (Prev)); 620 Add_Char_To_Name_Buffer ('_'); 621 Add_Str_To_Name_Buffer (Buf); 622 Set_Chars (Prev, Name_Find); 623 end; 624 625 Error_Msg_Node_1 := Prev; 626 Error_Msg_SC ("unexpected identifier, possibly & was meant here"); 627 Scan; 628 end Merge_Identifier; 629 630 ------------------- 631 -- Next_Token_Is -- 632 ------------------- 633 634 function Next_Token_Is (Tok : Token_Type) return Boolean is 635 Scan_State : Saved_Scan_State; 636 Result : Boolean; 637 begin 638 Save_Scan_State (Scan_State); 639 Scan; 640 Result := (Token = Tok); 641 Restore_Scan_State (Scan_State); 642 return Result; 643 end Next_Token_Is; 644 645 ------------------- 646 -- No_Constraint -- 647 ------------------- 648 649 procedure No_Constraint is 650 begin 651 -- If we have a token that could start a constraint on the same line 652 -- then cnsider this an illegal constraint. It seems unlikely it could 653 -- be anything else if it is on the same line. 654 655 if Token in Token_Class_Consk then 656 Error_Msg_SC ("constraint not allowed here"); 657 Discard_Junk_Node (P_Constraint_Opt); 658 end if; 659 end No_Constraint; 660 661 --------------------- 662 -- Pop_Scope_Stack -- 663 --------------------- 664 665 procedure Pop_Scope_Stack is 666 begin 667 pragma Assert (Scope.Last > 0); 668 Scope.Decrement_Last; 669 670 if Debug_Flag_P then 671 Error_Msg_Uint_1 := UI_From_Int (Scope.Last); 672 Error_Msg_SC ("decrement scope stack ptr, new value = ^!"); 673 end if; 674 end Pop_Scope_Stack; 675 676 ---------------------- 677 -- Push_Scope_Stack -- 678 ---------------------- 679 680 procedure Push_Scope_Stack is 681 begin 682 Scope.Increment_Last; 683 684 if Style_Check_Max_Nesting_Level 685 and then Scope.Last = Style_Max_Nesting_Level + 1 686 then 687 Error_Msg 688 ("(style) maximum nesting level exceeded", 689 First_Non_Blank_Location); 690 end if; 691 692 Scope.Table (Scope.Last).Junk := False; 693 Scope.Table (Scope.Last).Node := Empty; 694 695 if Debug_Flag_P then 696 Error_Msg_Uint_1 := UI_From_Int (Scope.Last); 697 Error_Msg_SC ("increment scope stack ptr, new value = ^!"); 698 end if; 699 end Push_Scope_Stack; 700 701 ---------------------- 702 -- Separate_Present -- 703 ---------------------- 704 705 function Separate_Present return Boolean is 706 Scan_State : Saved_Scan_State; 707 708 begin 709 if Token = Tok_Separate then 710 return True; 711 712 elsif Token /= Tok_Identifier then 713 return False; 714 715 else 716 Save_Scan_State (Scan_State); 717 Scan; -- past identifier 718 719 if Token = Tok_Semicolon then 720 Restore_Scan_State (Scan_State); 721 return Bad_Spelling_Of (Tok_Separate); 722 723 else 724 Restore_Scan_State (Scan_State); 725 return False; 726 end if; 727 end if; 728 end Separate_Present; 729 730 -------------------------- 731 -- Signal_Bad_Attribute -- 732 -------------------------- 733 734 procedure Signal_Bad_Attribute is 735 begin 736 Bad_Attribute (Token_Node, Token_Name, Warn => False); 737 end Signal_Bad_Attribute; 738 739 ----------------------------- 740 -- Token_Is_At_End_Of_Line -- 741 ----------------------------- 742 743 function Token_Is_At_End_Of_Line return Boolean is 744 S : Source_Ptr; 745 746 begin 747 -- Skip past blanks and horizontal tabs 748 749 S := Scan_Ptr; 750 while Source (S) = ' ' or else Source (S) = ASCII.HT loop 751 S := S + 1; 752 end loop; 753 754 -- We are at end of line if at a control character (CR/LF/VT/FF/EOF) 755 -- or if we are at the start of an end of line comment sequence. 756 757 return Source (S) < ' ' 758 or else (Source (S) = '-' and then Source (S + 1) = '-'); 759 end Token_Is_At_End_Of_Line; 760 761 ------------------------------- 762 -- Token_Is_At_Start_Of_Line -- 763 ------------------------------- 764 765 function Token_Is_At_Start_Of_Line return Boolean is 766 begin 767 return (Token_Ptr = First_Non_Blank_Location or else Token = Tok_EOF); 768 end Token_Is_At_Start_Of_Line; 769 770 ----------------------------------- 771 -- Warn_If_Standard_Redefinition -- 772 ----------------------------------- 773 774 procedure Warn_If_Standard_Redefinition (N : Node_Id) is 775 begin 776 if Warn_On_Standard_Redefinition then 777 declare 778 C : constant Entity_Id := Current_Entity (N); 779 begin 780 if Present (C) and then Sloc (C) = Standard_Location then 781 Error_Msg_N ("redefinition of entity& in Standard?K?", N); 782 end if; 783 end; 784 end if; 785 end Warn_If_Standard_Redefinition; 786 787end Util; 788