1------------------------------------------------------------------------------ 2-- -- 3-- GNAT COMPILER COMPONENTS -- 4-- -- 5-- E R R O U T -- 6-- -- 7-- S p e c -- 8-- -- 9-- Copyright (C) 1992-2021, Free Software Foundation, Inc. -- 10-- -- 11-- GNAT is free software; you can redistribute it and/or modify it under -- 12-- terms of the GNU General Public License as published by the Free Soft- -- 13-- ware Foundation; either version 3, or (at your option) any later ver- -- 14-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- 15-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- 16-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- 17-- for more details. You should have received a copy of the GNU General -- 18-- Public License distributed with GNAT; see file COPYING3. If not, go to -- 19-- http://www.gnu.org/licenses for a complete copy of the license. -- 20-- -- 21-- GNAT was originally developed by the GNAT team at New York University. -- 22-- Extensive contributions were provided by Ada Core Technologies Inc. -- 23-- -- 24------------------------------------------------------------------------------ 25 26-- This package contains the routines to output error messages. They are 27-- basically system independent, however in some environments, e.g. when the 28-- parser is embedded into an editor, it may be appropriate to replace the 29-- implementation of this package. 30 31with Err_Vars; 32with Erroutc; 33with Namet; use Namet; 34with Table; 35with Types; use Types; 36with Uintp; use Uintp; 37 38with System; 39 40package Errout is 41 42 Current_Error_Source_File : Source_File_Index 43 renames Err_Vars.Current_Error_Source_File; 44 -- Id of current messages. Used to post file name when unit changes. This 45 -- is initialized to Main_Source_File at the start of a compilation, which 46 -- means that no file names will be output unless there are errors in 47 -- units other than the main unit. However, if the main unit has a pragma 48 -- Source_Reference line, then this is initialized to No_Source_File, to 49 -- force an initial reference to the real source file name. 50 51 Raise_Exception_On_Error : Nat renames Err_Vars.Raise_Exception_On_Error; 52 -- If this value is non-zero, then any attempt to generate an error 53 -- message raises the exception Error_Msg_Exception, and the error message 54 -- is not output. This is used for defending against junk resulting from 55 -- illegalities, and also for substitution of more appropriate error 56 -- messages from higher semantic levels. It is a counter so that the 57 -- increment/decrement protocol nests neatly. 58 59 Error_Msg_Exception : exception renames Err_Vars.Error_Msg_Exception; 60 -- Exception raised if Raise_Exception_On_Error is true 61 62 Warning_Doc_Switch : Boolean renames Err_Vars.Warning_Doc_Switch; 63 -- If this is set True, then the ??/?*?/?$?/?x?/?.x?/?_x? insertion 64 -- sequences in error messages generate appropriate tags for the output 65 -- error messages. If this switch is False, then these sequences are still 66 -- recognized (for the purposes of implementing the pattern matching in 67 -- pragmas Warnings (Off,..) and Warning_As_Pragma(...) but do not result 68 -- in adding the error message tag. The -gnatw.d switch sets this flag 69 -- True, -gnatw.D sets this flag False. 70 71 Current_Node : Node_Id := Empty; 72 -- Used by Error_Msg as a default Node_Id. 73 -- Relevant only when Opt.Include_Subprogram_In_Messages is set. 74 75 ----------------------------------- 76 -- Suppression of Error Messages -- 77 ----------------------------------- 78 79 -- In an effort to reduce the impact of redundant error messages, the 80 -- error output routines in this package normally suppress certain 81 -- classes of messages as follows: 82 83 -- 1. Identical messages placed at the same point in the text. Such 84 -- duplicate error message result for example from rescanning 85 -- sections of the text that contain lexical errors. Only one of 86 -- such a set of duplicate messages is output, and the rest are 87 -- suppressed. 88 89 -- 2. If more than one parser message is generated for a single source 90 -- line, then only the first message is output, the remaining 91 -- messages on the same line are suppressed. 92 93 -- 3. If a message is posted on a node for which a message has been 94 -- previously posted, then only the first message is retained. The 95 -- Error_Posted flag is used to detect such multiple postings. Note 96 -- that this only applies to semantic messages, since otherwise 97 -- for parser messages, this would be a special case of case 2. 98 99 -- 4. If a message is posted on a node whose Etype or Entity 100 -- fields reference entities on which an error message has 101 -- already been placed, as indicated by the Error_Posted flag 102 -- being set on these entities, then the message is suppressed. 103 104 -- 5. If a message attempts to insert an Error node, or a direct 105 -- reference to the Any_Type node, then the message is suppressed. 106 107 -- 6. Note that cases 2-5 only apply to error messages, not warning 108 -- messages. Warning messages are only suppressed for case 1, and 109 -- when they come from other than the main extended unit. 110 111 -- 7. If an error or warning references an internal name, and we have 112 -- already placed an error (not warning) message at that location, 113 -- then we assume this is cascaded junk and delete the message. 114 115 -- This normal suppression action may be overridden in cases 2-5 (but 116 -- not in case 1 or 7) by setting All_Errors mode, or by setting the 117 -- unconditional message insertion character (!) as described below. 118 119 --------------------------------------------------------- 120 -- Error Message Text and Message Insertion Characters -- 121 --------------------------------------------------------- 122 123 -- Error message text strings are composed of lower case letters, digits 124 -- and the special characters space, comma, period, colon and semicolon, 125 -- apostrophe and parentheses. Special insertion characters can also 126 -- appear which cause the error message circuit to modify the given 127 -- string as follows: 128 129 -- Insertion character % (Percent: insert name from Names table) 130 -- The character % is replaced by the text for the name specified by 131 -- the Name_Id value stored in Error_Msg_Name_1. A blank precedes the 132 -- name if it is preceded by a non-blank character other than left 133 -- parenthesis. The name is enclosed in quotes unless manual quotation 134 -- mode is set. If the Name_Id is set to No_Name, then no insertion 135 -- occurs; if the Name_Id is set to Error_Name, then the string 136 -- <error> is inserted. A second and third % may appear in a single 137 -- message, similarly replaced by the names which are specified by the 138 -- Name_Id values stored in Error_Msg_Name_2 and Error_Msg_Name_3. The 139 -- names are decoded and cased according to the current identifier 140 -- casing mode. Note: if a unit name ending with %b or %s is passed 141 -- for this kind of insertion, this suffix is simply stripped. Use a 142 -- unit name insertion ($) to process the suffix. 143 -- 144 -- Note: the special names _xxx (xxx = Pre/Post/Invariant) are changed 145 -- to insert the string xxx'Class into the message. 146 147 -- Insertion character %% (Double percent: insert literal name) 148 -- The character sequence %% acts as described above for %, except 149 -- that the name is simply obtained with Get_Name_String and is not 150 -- decoded or cased, it is inserted literally from the names table. 151 -- A trailing %b or %s is not treated specially. 152 -- 153 -- Note: the special names _xxx (xxx = Pre/Post/Invariant) are changed 154 -- to insert the string xxx'Class into the message. 155 156 -- Insertion character $ (Dollar: insert unit name from Names table) 157 -- The character $ is treated similarly to %, except that the name is 158 -- obtained from the Unit_Name_Type value in Error_Msg_Unit_1 and 159 -- Error_Msg_Unit_2, as provided by Get_Unit_Name_String in package 160 -- Uname. Note that this name includes the postfix (spec) or (body) 161 -- strings. If this postfix is not required, use the normal % insertion 162 -- for the unit name. 163 164 -- Insertion character { (Left brace: insert file name from names table) 165 -- The character { is treated similarly to %, except that the input 166 -- value is a File_Name_Type value stored in Error_Msg_File_1 or 167 -- Error_Msg_File_2 or Error_Msg_File_3. The value is output literally, 168 -- enclosed in quotes as for %, but the case is not modified, the 169 -- insertion is the exact string stored in the names table without 170 -- adjusting the casing. 171 172 -- Insertion character * (Asterisk: insert reserved word name) 173 -- The insertion character * is treated exactly like % except that the 174 -- resulting name is cased according to the default conventions for 175 -- reserved words (see package Scans). 176 177 -- Insertion character & (Ampersand: insert name from node) 178 -- The insertion character & is treated similarly to %, except that 179 -- the name is taken from the Chars field of the given node, and may 180 -- refer to a child unit name, or a selected component. The casing is, 181 -- if possible, taken from the original source reference, which is 182 -- obtained from the Sloc field of the given node or nodes. If no Sloc 183 -- is available (happens e.g. for nodes in package Standard), then the 184 -- default case (see Scans spec) is used. The nodes to be used are 185 -- stored in Error_Msg_Node_1, Error_Msg_Node_2. No insertion occurs 186 -- for the Empty node, and the Error node results in the insertion of 187 -- the characters <error>. In addition, if the special global variable 188 -- Error_Msg_Qual_Level is non-zero, then the reference will include 189 -- up to the given number of levels of qualification, using the scope 190 -- chain. 191 -- 192 -- Note: the special names _xxx (xxx = Pre/Post/Invariant) are changed 193 -- to insert the string xxx'Class into the message. 194 195 -- Insertion character # (Pound: insert line number reference) 196 -- The character # is replaced by the string indicating the source 197 -- position stored in Error_Msg_Sloc. There are three cases: 198 -- 199 -- for package Standard: in package Standard 200 -- for locations in current file: at line nnn:ccc 201 -- for locations in other files: at filename:nnn:ccc 202 -- 203 -- By convention, the # insertion character is only used at the end of 204 -- an error message, so the above strings only appear as the last 205 -- characters of an error message. The only exceptions to this rule 206 -- are that an RM reference may follow in the form (RM .....) and a 207 -- right parenthesis may immediately follow the #. In the case of 208 -- continued messages, # can only appear at the end of a group of 209 -- continuation messages, except that \\ messages which always start 210 -- a new line end the sequence from the point of view of this rule. 211 -- The idea is that for any use of -gnatj, it will still be the case 212 -- that a location reference appears only at the end of a line. 213 214 -- Note: the output of the string "at " is suppressed if the string 215 -- " from" or " from " immediately precedes the insertion character #. 216 -- Certain messages read better with from than at. 217 218 -- Insertion character } (Right brace: insert type reference) 219 -- The character } is replaced by a string describing the type 220 -- referenced by the entity whose Id is stored in Error_Msg_Node_1. 221 -- The string gives the name or description of the type, and also 222 -- where appropriate the location of its declaration. Special cases 223 -- like "some integer type" are handled appropriately. Only one } is 224 -- allowed in a message, since there is not enough room for two (the 225 -- insertion can be quite long, including a file name). In addition, if 226 -- the special global variable Error_Msg_Qual_Level is non-zero, then 227 -- the reference will include up to the given number of levels of 228 -- qualification, using the scope chain. 229 230 -- Insertion character @ (At: insert column number reference) 231 -- The character @ is replaced by null if the RM_Column_Check mode is 232 -- off (False). If the switch is on (True), then @ is replaced by the 233 -- text string " in column nnn" where nnn is the decimal 234 -- representation of the column number stored in Error_Msg_Col plus 235 -- one (the plus one is because the number is stored 0-origin and 236 -- displayed 1-origin). 237 238 -- Insertion character ^ (Caret: insert integer value) 239 -- The character ^ is replaced by the decimal conversion of the Uint 240 -- value stored in Error_Msg_Uint_1, with a possible leading minus. 241 -- A second ^ may occur in the message, in which case it is replaced 242 -- by the decimal conversion of the Uint value in Error_Msg_Uint_2. 243 244 -- Insertion character > (Greater Than: run time name) 245 -- The character > is replaced by a string of the form (name) if 246 -- Targparm scanned out a Run_Time_Name (see package Targparm for 247 -- details). The name is enclosed in parentheses and output in mixed 248 -- case mode (upper case after any space in the name). If no run time 249 -- name is defined, this insertion character has no effect. 250 251 -- Insertion character ! (Exclamation: unconditional message) 252 -- The character ! appearing anywhere in the text of a message makes 253 -- the message unconditional which means that it is output even if it 254 -- would normally be suppressed. See section above for a description 255 -- of the cases in which messages are normally suppressed. Note that 256 -- in the case of warnings, the meaning is that the warning should not 257 -- be removed in dead code (that's the only time that the use of ! 258 -- has any effect for a warning). 259 -- 260 -- Note: the presence of ! is ignored in continuation messages (i.e. 261 -- messages starting with the \ insertion character). The effect of the 262 -- use of ! in a parent message automatically applies to all of its 263 -- continuation messages (since we clearly don't want any case in which 264 -- continuations are separated from the main message). It is allowable 265 -- to put ! in continuation messages, and the usual style is to include 266 -- it, since it makes it clear that the continuation is part of an 267 -- unconditional message. 268 269 -- Insertion character !! (Double exclamation: unconditional warning) 270 -- Normally warning messages issued in other than the main unit are 271 -- suppressed. If the message contains !! then this suppression is 272 -- avoided. This is currently used by the Compile_Time_Warning pragma 273 -- to ensure the message for a with'ed unit is output, and for warnings 274 -- on ineffective back-end inlining, which is detected in units that 275 -- contain subprograms to be inlined in the main program. It is also 276 -- used by the Compiler_Unit_Warning pragma for similar reasons. 277 278 -- Insertion character ? (Question: warning message -- OBSOLETE) 279 -- The character ? appearing anywhere in a message makes the message 280 -- warning instead of a normal error message, and the text of the 281 -- message will be preceded by "warning:" in the normal case. The 282 -- handling of warnings is further controlled by the Warning_Mode 283 -- option (-w switch), see package Opt for further details, and also by 284 -- the current setting from pragma Warnings. This pragma applies only 285 -- to warnings issued from the semantic phase (not the parser), but 286 -- currently all relevant warnings are posted by the semantic phase 287 -- anyway. Messages starting with (style) are also treated as warning 288 -- messages. 289 -- 290 -- Note: when a warning message is output, the text of the message is 291 -- preceded by "warning: " in the normal case. An exception to this 292 -- rule occurs when the text of the message starts with "info: " in 293 -- which case this string is not prepended. This allows callers to 294 -- label certain warnings as informational messages, rather than as 295 -- warning messages requiring some action. 296 -- 297 -- Note: the presence of ? is ignored in continuation messages (i.e. 298 -- messages starting with the \ insertion character). The warning 299 -- status of continuations is determined only by the parent message 300 -- which is being continued. It is allowable to put ? in continuation 301 -- messages, and the usual style is to include it, since it makes it 302 -- clear that the continuation is part of a warning message, but it is 303 -- not necessary to go through any computational effort to include it. 304 -- 305 -- Note: this usage is obsolete; use ?? ?*? ?$? ?x? ?.x? ?_x? to 306 -- specify the string to be added when Warn_Doc_Switch is set to True. 307 -- If this switch is True, then for simple ? messages it has no effect. 308 -- This simple form is to ease transition and may be removed later 309 -- except for GNATprove-specific messages (info and warnings) which are 310 -- not subject to the same GNAT warning switches. 311 312 -- Insertion character ?? (Two question marks: default warning) 313 -- Like ?, but if the flag Warn_Doc_Switch is True, adds the string 314 -- "[enabled by default]" at the end of the warning message. For 315 -- continuations, use this in each continuation message. 316 317 -- Insertion character ?x? ?.x? ?_x? (warning with switch) 318 -- Like ?, but if the flag Warn_Doc_Switch is True, adds the string 319 -- "[-gnatwx]", "[-gnatw.x]", or "[-gnatw_x]", at the end of the 320 -- warning message. x must be lower case. For continuations, use this 321 -- on each continuation message. 322 323 -- Insertion character ?*? (restriction warning) 324 -- Like ?, but if the flag Warn_Doc_Switch is True, adds the string 325 -- "[restriction warning]" at the end of the warning message. For 326 -- continuations, use this on each continuation message. 327 328 -- Insertion character ?$? (elaboration informational messages) 329 -- Like ?, but if the flag Warn_Doc_Switch is True, adds the string 330 -- "[-gnatel]" at the end of the info message. This is used for the 331 -- messages generated by the switch -gnatel. For continuations, use 332 -- this on each continuation message. 333 334 -- Insertion character < (Less Than: conditional warning message) 335 -- The character < appearing anywhere in a message is used for a 336 -- conditional error message. If Error_Msg_Warn is True, then the 337 -- effect is the same as ? described above, and in particular << <x< 338 -- <$< <*< have the effect of ?? ?x? ?$? ?*? respectively. If 339 -- Error_Msg_Warn is False, then the < << or <X< sequence is ignored 340 -- and the message is treated as a error rather than a warning. 341 342 -- Insertion character A-Z (Upper case letter: Ada reserved word) 343 -- If two or more upper case letters appear in the message, they are 344 -- taken as an Ada reserved word, and are converted to the default 345 -- case for reserved words (see Scans package spec). Surrounding 346 -- quotes are added unless manual quotation mode is currently set. 347 -- RM and SPARK are special exceptions, they are never treated as 348 -- keywords, and just appear verbatim, with no surrounding quotes. 349 -- As a special case, 'R'M is used instead of RM (which is not treated 350 -- as a keyword) to indicate when the reference to the RM is possibly 351 -- not useful anymore, and could possibly be replaced by a comment 352 -- in the source. 353 354 -- Insertion character ` (Backquote: set manual quotation mode) 355 -- The backquote character always appears in pairs. Each backquote of 356 -- the pair is replaced by a double quote character. In addition, any 357 -- reserved keywords, or name insertions between these backquotes are 358 -- not surrounded by the usual automatic double quotes. See the 359 -- section below on manual quotation mode for further details. 360 361 -- Insertion character ' (Quote: literal character) 362 -- Precedes a character which is placed literally into the message. 363 -- Used to insert characters into messages that are one of the 364 -- insertion characters defined here. Also used for insertion of 365 -- upper case letter sequences not to be treated as keywords. 366 367 -- Insertion character \ (Backslash: continuation message) 368 -- Indicates that the message is a continuation of a message 369 -- previously posted. This is used to ensure that such groups of 370 -- messages are treated as a unit. The \ character must be the first 371 -- character of the message text. 372 373 -- Insertion character \\ (Two backslashes: continuation with new line) 374 -- This differs from \ only in -gnatjnn mode (Error_Message_Line_Length 375 -- set non-zero). This sequence forces a new line to start even when 376 -- continuations are being gathered into a single message. 377 378 -- Insertion character | (Vertical bar: non-serious error) 379 -- By default, error messages (but not warning messages) are considered 380 -- to be fatal error messages, which prevent expansion and generation 381 -- of code. If the insertion character | appears, the message is 382 -- considered to be nonserious, and Serious_Errors_Detected is not 383 -- incremented, so expansion is not prevented by such a msg. This 384 -- insertion character is ignored in continuation messages. 385 386 -- Insertion character ~ (Tilde: insert string) 387 -- Indicates that Error_Msg_String (1 .. Error_Msg_Strlen) is to be 388 -- inserted to replace the ~ character. The string is inserted in the 389 -- literal form it appears, without any action on special characters. 390 391 -- Insertion character [ (Left bracket: will/would be raised at run time) 392 -- This is used in messages about exceptions being raised at run-time. 393 -- If the current message is a warning message, then if the code is 394 -- executed, the exception will be raised, and [ inserts: 395 -- 396 -- will be raised at run time 397 -- 398 -- If the current message is an error message, then it is an error 399 -- because the exception would have been raised and [ inserts: 400 -- 401 -- would have been raised at run time 402 -- 403 -- Typically the message contains a < insertion which means that the 404 -- message is a warning or error depending on Error_Msg_Warn. This is 405 -- most typically used in the context of messages which are normally 406 -- warnings, but are errors in GNATprove mode, corresponding to the 407 -- permission in the definition of SPARK that allows an implementation 408 -- to reject a program as illegal if a situation arises in which the 409 -- compiler can determine that it is certain that a run-time check 410 -- would have fail if the statement was executed. 411 412 -- Insertion character ] (Right bracket: may/might be raised at run time) 413 -- This is like [ except that the insertion messages say may/might, 414 -- instead of will/would. 415 416 -- Insertion sequence "(style)" (style message) 417 -- This appears only at the start of the message (and not any of its 418 -- continuations, if any), and indicates that the message is a style 419 -- message. Style messages are also considered to be warnings, but 420 -- they do not get a tag. 421 422 -- Insertion sequence "info: " (informational message) 423 -- This appears only at the start of the message (and not any of its 424 -- continuations, if any), and indicates that the message is an info 425 -- message. The message will be output with this prefix, and if there 426 -- are continuations that are not printed using the -gnatj switch they 427 -- will also have this prefix. Informational messages are usually also 428 -- warnings, but they don't have to be. 429 430 -- Insertion sequence "low: " or "medium: " or "high: " (check message) 431 -- This appears only at the start of the message (and not any of its 432 -- continuations, if any), and indicates that the message is a check 433 -- message. The message will be output with this prefix. Check 434 -- messages are not fatal (so are like info messages in that respect) 435 -- and are not controlled by pragma Warnings. 436 437 ----------------------------------------------------- 438 -- Global Values Used for Error Message Insertions -- 439 ----------------------------------------------------- 440 441 -- The following global variables are essentially additional parameters 442 -- passed to the error message routine for insertion sequences described 443 -- above. The reason these are passed globally is that the insertion 444 -- mechanism is essentially an untyped one in which the appropriate 445 -- variables are set depending on the specific insertion characters used. 446 447 -- Note that is mandatory that the caller ensure that global variables 448 -- are set before the Error_Msg call, otherwise the result is undefined. 449 450 -- Also note that calls to Error_Msg and its variants destroy the value of 451 -- these global variables, as a way to support the inclusion of multiple 452 -- insertion characters of the same type. For example, support for 453 -- multiple characters % for a name in the message (up to 3) is 454 -- implemented by unconditionally shifting the value for Error_Msg_Nam_2 455 -- to Error_Msg_Nam_1 and from Error_Msg_Nam_3 to Error_Msg_Nam_2 after 456 -- dealing with insertion character %. The caller should ensure that all 457 -- global variables are restored if needed prior to calling Error_Msg. 458 459 Error_Msg_Col : Column_Number renames Err_Vars.Error_Msg_Col; 460 -- Column for @ insertion character in message 461 462 Error_Msg_Uint_1 : Uint renames Err_Vars.Error_Msg_Uint_1; 463 Error_Msg_Uint_2 : Uint renames Err_Vars.Error_Msg_Uint_2; 464 -- Uint values for ^ insertion characters in message 465 466 Error_Msg_Sloc : Source_Ptr renames Err_Vars.Error_Msg_Sloc; 467 -- Source location for # insertion character in message 468 469 Error_Msg_Name_1 : Name_Id renames Err_Vars.Error_Msg_Name_1; 470 Error_Msg_Name_2 : Name_Id renames Err_Vars.Error_Msg_Name_2; 471 Error_Msg_Name_3 : Name_Id renames Err_Vars.Error_Msg_Name_3; 472 -- Name_Id values for % insertion characters in message 473 474 Error_Msg_File_1 : File_Name_Type renames Err_Vars.Error_Msg_File_1; 475 Error_Msg_File_2 : File_Name_Type renames Err_Vars.Error_Msg_File_2; 476 Error_Msg_File_3 : File_Name_Type renames Err_Vars.Error_Msg_File_3; 477 -- File_Name_Type values for { insertion characters in message 478 479 Error_Msg_Unit_1 : Unit_Name_Type renames Err_Vars.Error_Msg_Unit_1; 480 Error_Msg_Unit_2 : Unit_Name_Type renames Err_Vars.Error_Msg_Unit_2; 481 -- Unit_Name_Type values for $ insertion characters in message 482 483 Error_Msg_Node_1 : Node_Id renames Err_Vars.Error_Msg_Node_1; 484 Error_Msg_Node_2 : Node_Id renames Err_Vars.Error_Msg_Node_2; 485 -- Node_Id values for & insertion characters in message 486 487 Error_Msg_Qual_Level : Nat renames Err_Vars.Error_Msg_Qual_Level; 488 -- Number of levels of qualification required for type name (see the 489 -- description of the } insertion character). Note that this value does 490 -- not get reset by any Error_Msg call, so the caller is responsible 491 -- for resetting it. 492 493 Error_Msg_Warn : Boolean renames Err_Vars.Error_Msg_Warn; 494 -- Used if current message contains a < insertion character to indicate 495 -- if the current message is a warning message. Must be set appropriately 496 -- before any call to Error_Msg_xxx with a < insertion character present. 497 -- Setting is irrelevant if no < insertion character is present. 498 499 Error_Msg_String : String renames Err_Vars.Error_Msg_String; 500 Error_Msg_Strlen : Natural renames Err_Vars.Error_Msg_Strlen; 501 -- Used if current message contains a ~ insertion character to indicate 502 -- insertion of the string Error_Msg_String (1 .. Error_Msg_Strlen). 503 504 ----------------------------------------------------- 505 -- Format of Messages and Manual Quotation Control -- 506 ----------------------------------------------------- 507 508 -- Messages are generally all in lower case, except for inserted names 509 -- and appear in one of the following three forms: 510 511 -- error: text 512 -- warning: text 513 514 -- The prefixes error and warning are supplied automatically (depending 515 -- on the use of the ? insertion character), and the call to the error 516 -- message routine supplies the text. The "error: " prefix is omitted 517 -- if -gnatd_U is among the options given to gnat. 518 519 -- Reserved Ada keywords in the message are in the default keyword case 520 -- (determined from the given source program), surrounded by quotation 521 -- marks. This is achieved by spelling the reserved word in upper case 522 -- letters, which is recognized as a request for insertion of quotation 523 -- marks by the error text processor. Thus for example: 524 525 -- Error_Msg_AP ("IS expected"); 526 527 -- would result in the output of one of the following: 528 529 -- error: "is" expected 530 -- error: "IS" expected 531 -- error: "Is" expected 532 533 -- the choice between these being made by looking at the casing convention 534 -- used for keywords (actually the first compilation unit keyword) in the 535 -- source file. 536 537 -- Note: a special exception is that RM is never treated as a keyword 538 -- but instead is copied literally into the message, this avoids the 539 -- need for writing 'R'M for all reference manual quotes. A similar 540 -- exception is applied to the occurrence of the string SPARK used in 541 -- error messages about the SPARK subset of Ada. 542 543 -- In the case of names, the default mode for the error text processor 544 -- is to surround the name by quotation marks automatically. The case 545 -- used for the identifier names is taken from the source program where 546 -- possible, and otherwise is the default casing convention taken from 547 -- the source file usage. 548 549 -- In some cases, better control over the placement of quote marks is 550 -- required. This is achieved using manual quotation mode. In this mode, 551 -- one or more insertion sequences is surrounded by backquote characters. 552 -- The backquote characters are output as double quote marks, and normal 553 -- automatic insertion of quotes is suppressed between the double quotes. 554 -- For example: 555 556 -- Error_Msg_AP ("`END &;` expected"); 557 558 -- generates a message like 559 560 -- error: "end Open_Scope;" expected 561 562 -- where the node specifying the name Open_Scope has been stored in 563 -- Error_Msg_Node_1 prior to the call. The great majority of error 564 -- messages operates in normal quotation mode. 565 566 -- Note: the normal automatic insertion of spaces before insertion 567 -- sequences (such as those that come from & and %) is suppressed in 568 -- manual quotation mode, so blanks, if needed as in the above example, 569 -- must be explicitly present. 570 571 ---------------------------- 572 -- Message ID Definitions -- 573 ---------------------------- 574 575 subtype Error_Msg_Id is Erroutc.Error_Msg_Id; 576 function "=" (Left, Right : Error_Msg_Id) return Boolean 577 renames Erroutc."="; 578 -- A type used to represent specific error messages. Used by the clients 579 -- of this package only in the context of the Get_Error_Id and 580 -- Change_Error_Text subprograms. 581 582 No_Error_Msg : constant Error_Msg_Id := Erroutc.No_Error_Msg; 583 -- A constant which is different from any value returned by Get_Error_Id. 584 -- Typically used by a client to indicate absense of a saved Id value. 585 586 Warning_Msg : Error_Msg_Id := No_Error_Msg; 587 -- This is set if a warning message is generated to the ID of the resulting 588 -- message. Continuation messages have no effect. It is legitimate for the 589 -- client to set this to No_Error_Msg and then test it to see if a warning 590 -- message has been issued. 591 592 procedure Delete_Warning_And_Continuations (Msg : Error_Msg_Id); 593 -- Deletes the given warning message and all its continuations. This is 594 -- typically used in conjunction with reading the value of Warning_Msg. 595 596 function Get_Msg_Id return Error_Msg_Id renames Erroutc.Get_Msg_Id; 597 -- Returns the Id of the message most recently posted using one of the 598 -- Error_Msg routines. 599 600 function Get_Location (E : Error_Msg_Id) return Source_Ptr 601 renames Erroutc.Get_Location; 602 -- Returns the flag location of the error message with the given id E 603 604 ------------------------ 605 -- List Pragmas Table -- 606 ------------------------ 607 608 -- When a pragma Page or pragma List is encountered by the parser, an 609 -- entry is made in the following table. This table is then used to 610 -- control the full listing if one is being generated. Note that the 611 -- reason we do the processing in the parser is so that we get proper 612 -- listing control even in syntax check only mode. 613 614 type List_Pragma_Type is (List_On, List_Off, Page); 615 616 type List_Pragma_Record is record 617 Ptyp : List_Pragma_Type; 618 Ploc : Source_Ptr; 619 end record; 620 621 -- Note: Ploc points to the terminating semicolon in the List_Off and Page 622 -- cases, and to the pragma keyword for List_On. In the case of a pragma 623 -- List_Off, a List_On entry is also made in the table, pointing to the 624 -- pragma keyword. This ensures that, as required, a List (Off) pragma is 625 -- listed even in list off mode. 626 627 package List_Pragmas is new Table.Table ( 628 Table_Component_Type => List_Pragma_Record, 629 Table_Index_Type => Int, 630 Table_Low_Bound => 1, 631 Table_Initial => 50, 632 Table_Increment => 200, 633 Table_Name => "List_Pragmas"); 634 635 --------------------------- 636 -- Ignore_Errors Feature -- 637 --------------------------- 638 639 -- In certain cases, notably for optional subunits, the compiler operates 640 -- in a mode where errors are to be ignored, and the whole unit is to be 641 -- considered as not present. To implement this we provide the following 642 -- flag to enable special handling, where error messages are suppressed, 643 -- but the Fatal_Error flag will still be set in the normal manner. 644 645 Ignore_Errors_Enable : Nat := 0; 646 -- Triggering switch. If non-zero, then ignore errors mode is activated. 647 -- This is a counter to allow convenient nesting of enable/disable. 648 649 ----------------------- 650 -- CODEFIX Facility -- 651 ----------------------- 652 653 -- The GNAT Studio and GNATBench IDE's have a codefix facility that allows 654 -- for automatic correction of a subset of the errors and warnings issued 655 -- by the compiler. This is done by recognizing the text of specific 656 -- messages using appropriate matching patterns. 657 658 -- The text of such messages should not be altered without coordinating 659 -- with the codefix code. All such messages are marked by a specific 660 -- style of comments, as shown by the following example: 661 662 -- Error_Msg_N -- CODEFIX 663 -- (parameters ....) 664 665 -- Any message marked with this -- CODEFIX comment should not be modified 666 -- without appropriate coordination. 667 668 ------------------------------ 669 -- Error Output Subprograms -- 670 ------------------------------ 671 672 procedure Initialize; 673 -- Initializes for output of error messages. Must be called for each 674 -- source file before using any of the other routines in the package. 675 676 procedure Finalize (Last_Call : Boolean); 677 -- Finalize processing of error message list. Includes processing for 678 -- duplicated error messages, and other similar final adjustment of the 679 -- list of error messages. Note that this procedure must be called before 680 -- calling Compilation_Errors to determine if there were any errors. It 681 -- is perfectly fine to call Finalize more than once, providing that the 682 -- parameter Last_Call is set False for every call except the last call. 683 684 -- This multiple call capability is used to do some processing that may 685 -- generate messages. Call Finalize to eliminate duplicates and remove 686 -- deleted warnings. Test for compilation errors using Compilation_Errors, 687 -- then generate some more errors/warnings, call Finalize again to make 688 -- sure that all duplicates in these new messages are dealt with, then 689 -- finally call Output_Messages to output the final list of messages. The 690 -- argument Last_Call must be set False on all calls except the last call, 691 -- and must be set True on the last call (a value of True activates some 692 -- processing that must only be done after all messages are posted). 693 694 procedure Output_Messages; 695 -- Output list of messages, including messages giving number of detected 696 -- errors and warnings. 697 698 procedure Error_Msg 699 (Msg : String; Flag_Location : Source_Ptr); 700 procedure Error_Msg 701 (Msg : String; Flag_Span : Source_Span); 702 procedure Error_Msg 703 (Msg : String; Flag_Location : Source_Ptr; N : Node_Id); 704 procedure Error_Msg 705 (Msg : String; Flag_Span : Source_Span; N : Node_Id); 706 -- Output a message at specified location. Can be called from the parser 707 -- or the semantic analyzer. If N is set, points to the relevant node for 708 -- this message. The version with a span is preferred whenever possible, 709 -- in other cases the version with a location can still be used. 710 711 procedure Error_Msg 712 (Msg : String; 713 Flag_Location : Source_Ptr; 714 Is_Compile_Time_Pragma : Boolean); 715 -- Same as Error_Msg (String, Source_Ptr) except Is_Compile_Time_Pragma 716 -- lets the caller specify whether this is a Compile_Time_Warning or 717 -- Compile_Time_Error pragma. 718 719 procedure Error_Msg_S (Msg : String); 720 -- Output a message at current scan pointer location. This routine can be 721 -- called only from the parser, since it references Scan_Ptr. 722 723 procedure Error_Msg_AP (Msg : String); 724 -- Output a message just after the previous token. This routine can be 725 -- called only from the parser, since it references Prev_Token_Ptr. 726 727 procedure Error_Msg_BC (Msg : String); 728 -- Output a message just before the current token. Note that the important 729 -- difference between this and the previous routine is that the BC case 730 -- posts a flag on the current line, whereas AP can post a flag at the 731 -- end of the preceding line. This routine can be called only from the 732 -- parser, since it references Token_Ptr. 733 734 procedure Error_Msg_SC (Msg : String); 735 -- Output a message at the start of the current token, unless we are at 736 -- the end of file, in which case we always output the message after the 737 -- last real token in the file. This routine can be called only from the 738 -- parser, since it references Token_Ptr. 739 740 procedure Error_Msg_SP (Msg : String); 741 -- Output a message at the start of the previous token. This routine can 742 -- be called only from the parser, since it references Prev_Token_Ptr. 743 744 procedure Error_Msg_N (Msg : String; N : Node_Or_Entity_Id); 745 -- Output a message at the Sloc of the given node. This routine can be 746 -- called from the parser or the semantic analyzer, although the call from 747 -- the latter is much more common (and is the most usual way of generating 748 -- error messages from the analyzer). The message text may contain a 749 -- single & insertion, which will reference the given node. The message is 750 -- suppressed if the node N already has a message posted, or if it is a 751 -- warning and N is an entity node for which warnings are suppressed. 752 753 -- WARNING: There is a matching C declaration of this subprogram in fe.h 754 755 procedure Error_Msg_F (Msg : String; N : Node_Id); 756 -- Similar to Error_Msg_N except that the message is placed on the first 757 -- node of the construct N (First_Node (N)). Note that this procedure uses 758 -- Original_Node to look at the original source tree, since that's what we 759 -- want for placing an error message flag in the right place. 760 761 procedure Error_Msg_NE 762 (Msg : String; 763 N : Node_Or_Entity_Id; 764 E : Node_Or_Entity_Id); 765 -- Output a message at the Sloc of the given node N, with an insertion of 766 -- the name from the given entity node E. This is used by the semantic 767 -- routines, where this is a common error message situation. The Msg text 768 -- will contain a & or } as usual to mark the insertion point. This 769 -- routine can be called from the parser or the analyzer. 770 771 -- WARNING: There is a matching C declaration of this subprogram in fe.h 772 773 procedure Error_Msg_FE 774 (Msg : String; 775 N : Node_Id; 776 E : Node_Or_Entity_Id); 777 -- Same as Error_Msg_NE, except that the message is placed on the first 778 -- node of the construct N (First_Node (N)). 779 780 procedure Error_Msg_NEL 781 (Msg : String; 782 N : Node_Or_Entity_Id; 783 E : Node_Or_Entity_Id; 784 Flag_Location : Source_Ptr); 785 procedure Error_Msg_NEL 786 (Msg : String; 787 N : Node_Or_Entity_Id; 788 E : Node_Or_Entity_Id; 789 Flag_Span : Source_Span); 790 -- Exactly the same as Error_Msg_NE, except that the flag is placed at 791 -- the specified Flag_Location/Flag_Span instead of at Sloc (N). 792 793 procedure Error_Msg_NW 794 (Eflag : Boolean; 795 Msg : String; 796 N : Node_Or_Entity_Id); 797 -- This routine is used for posting a message conditionally. The message 798 -- is posted (with the same effect as Error_Msg_N (Msg, N) if and only 799 -- if Eflag is True and if the node N is within the main extended source 800 -- unit and comes from source. Typically this is a warning mode flag. 801 -- This routine can only be called during semantic analysis. It may not 802 -- be called during parsing. 803 804 procedure Change_Error_Text (Error_Id : Error_Msg_Id; New_Msg : String); 805 -- The error message text of the message identified by Id is replaced by 806 -- the given text. This text may contain insertion characters in the 807 -- usual manner, and need not be the same length as the original text. 808 809 procedure First_And_Last_Nodes 810 (C : Node_Id; 811 First_Node, Last_Node : out Node_Id); 812 -- Given a construct C, finds the first and last node in the construct, 813 -- i.e. the ones with the lowest and highest Sloc value. This is useful in 814 -- placing error msgs. Note that this procedure uses Original_Node to look 815 -- at the original source tree, since that's what we want for placing an 816 -- error message flag in the right place. 817 818 function First_Node (C : Node_Id) return Node_Id; 819 -- Return the first output of First_And_Last_Nodes 820 821 function First_Sloc (N : Node_Id) return Source_Ptr; 822 -- Given the node for an expression, return a source pointer value that 823 -- points to the start of the first token in the expression. In the case 824 -- where the expression is parenthesized, an attempt is made to include 825 -- the parentheses (i.e. to return the location of the initial paren). 826 827 function Get_Ignore_Errors return Boolean; 828 -- Return True if all error calls are ignored. 829 830 function Last_Node (C : Node_Id) return Node_Id; 831 -- Return the last output of First_And_Last_Nodes 832 833 function Last_Sloc (N : Node_Id) return Source_Ptr; 834 -- Given the node for an expression, return a source pointer value that 835 -- points to the end of the last token in the expression. In the case 836 -- where the expression is parenthesized, an attempt is made to include 837 -- the parentheses (i.e. to return the location of the final paren). 838 839 procedure Purge_Messages (From : Source_Ptr; To : Source_Ptr) 840 renames Erroutc.Purge_Messages; 841 -- All error messages whose location is in the range From .. To (not 842 -- including the end points) will be deleted from the error listing. 843 844 procedure Remove_Warning_Messages (N : Node_Id); 845 -- Remove any warning messages corresponding to the Sloc of N or any 846 -- of its descendant nodes. No effect if no such warnings. Note that 847 -- style messages (identified by the fact that they start with "(style)") 848 -- are not removed by this call. Basically the idea behind this procedure 849 -- is to remove warnings about execution conditions from known dead code. 850 851 procedure Remove_Warning_Messages (L : List_Id); 852 -- Remove warnings on all elements of a list (Calls Remove_Warning_Messages 853 -- on each element of the list, see above). 854 855 procedure Reset_Warnings; 856 -- Reset the counts related to warnings. This is used both to initialize 857 -- these counts and to reset them after each phase of analysis for a given 858 -- value of Opt.Warning_Mode in gnat2why. 859 860 procedure Set_Ignore_Errors (To : Boolean); 861 -- Following a call to this procedure with To=True, all error calls are 862 -- ignored. A call with To=False restores the default treatment in which 863 -- error calls are treated as usual (and as described in this spec). 864 865 procedure Set_Warnings_Mode_Off (Loc : Source_Ptr; Reason : String_Id) 866 renames Erroutc.Set_Warnings_Mode_Off; 867 -- Called in response to a pragma Warnings (Off) to record the source 868 -- location from which warnings are to be turned off. Reason is the 869 -- Reason from the pragma, or the null string if none is given. 870 871 procedure Set_Warnings_Mode_On (Loc : Source_Ptr) 872 renames Erroutc.Set_Warnings_Mode_On; 873 -- Called in response to a pragma Warnings (On) to record the source 874 -- location from which warnings are to be turned back on. 875 876 procedure Set_Specific_Warning_Off 877 (Loc : Source_Ptr; 878 Msg : String; 879 Reason : String_Id; 880 Config : Boolean; 881 Used : Boolean := False) 882 renames Erroutc.Set_Specific_Warning_Off; 883 -- This is called in response to the two argument form of pragma Warnings 884 -- where the first argument is OFF, and the second argument is a string 885 -- which identifies a specific warning to be suppressed. The first argument 886 -- is the start of the suppression range, and the second argument is the 887 -- string from the pragma. Loc is the location of the pragma (which is the 888 -- start of the range to suppress). Reason is the reason string from the 889 -- pragma, or the null string if no reason is given. Config is True for the 890 -- configuration pragma case (where there is no requirement for a matching 891 -- OFF pragma). Used is set True to disable the check that the warning 892 -- actually has the effect of suppressing a warning. 893 894 procedure Set_Specific_Warning_On 895 (Loc : Source_Ptr; 896 Msg : String; 897 Err : out Boolean) 898 renames Erroutc.Set_Specific_Warning_On; 899 -- This is called in response to the two argument form of pragma Warnings 900 -- where the first argument is ON, and the second argument is the prefix 901 -- of a specific warning to be suppressed. The first argument is the end 902 -- of the suppression range, and the second argument is the string from 903 -- the pragma. Err is set to True on return to report the error of no 904 -- matching Warnings Off pragma preceding this one. 905 906 function Compilation_Errors return Boolean; 907 -- Returns True if errors have been detected, or warnings in -gnatwe (treat 908 -- warnings as errors) mode. Note that it is mandatory to call Finalize 909 -- before calling this routine. To account for changes to Warning_Mode in 910 -- gnat2why between phases, the past or current presence of an error is 911 -- recorded in a global variable at each call. 912 913 procedure Error_Msg_CRT (Feature : String; N : Node_Id); 914 -- Posts a non-fatal message on node N saying that the feature identified 915 -- by the Feature argument is not supported in either configurable 916 -- run-time mode or no run-time mode (as appropriate). In the former case, 917 -- the name of the library is output if available. 918 919 procedure Error_Msg_PT (E : Entity_Id; Iface_Prim : Entity_Id); 920 -- Posts an error on protected type entry or subprogram E (referencing its 921 -- overridden interface primitive Iface_Prim) indicating wrong mode of the 922 -- first formal (RM 9.4(11.9/3)). 923 924 procedure Error_Msg_Ada_2005_Extension (Extension : String); 925 -- Analogous to Error_Msg_Ada_2012_Feature, but phrase the message using 926 -- "extension" and not "feature". This routine is only used in the parser, 927 -- so the error is always placed at the Token_Ptr. 928 929 procedure Error_Msg_Ada_2012_Feature (Feature : String; Loc : Source_Ptr); 930 -- If not operating in Ada 2012 mode or higher, posts errors complaining 931 -- that Feature is only supported in Ada 2012, with appropriate suggestions 932 -- to fix this. Loc is the location at which the flag is to be posted. 933 -- Feature, which appears at the start of the first generated message, may 934 -- contain error message insertion characters in the normal manner, and in 935 -- particular may start with | to flag a non-serious error. 936 937 procedure Error_Msg_Ada_2022_Feature (Feature : String; Loc : Source_Ptr); 938 -- Analogous to Error_Msg_Ada_2012_Feature, for Ada 2022 939 940 procedure Error_Msg_GNAT_Extension (Extension : String); 941 -- If not operating with extensions allowed, posts errors complaining 942 -- that Extension is only supported when the -gnatX switch is enabled, 943 -- with appropriate suggestions to fix it. 944 945 procedure dmsg (Id : Error_Msg_Id) renames Erroutc.dmsg; 946 -- Debugging routine to dump an error message 947 948 ------------------------------------ 949 -- SPARK Error Output Subprograms -- 950 ------------------------------------ 951 952 -- The following routines are intended to report semantic errors in SPARK 953 -- constructs subject to aspect/pragma SPARK_Mode. Note that syntax errors 954 -- must be reported using the Error_Msg_XXX routines. This allows for the 955 -- partial analysis of SPARK features when they are disabled via SPARK_Mode 956 -- set to "off". 957 958 procedure SPARK_Msg_N (Msg : String; N : Node_Or_Entity_Id); 959 pragma Inline (SPARK_Msg_N); 960 -- Same as Error_Msg_N, but the error is suppressed if SPARK_Mode is Off. 961 -- The routine is inlined because it acts as a simple wrapper. 962 963 procedure SPARK_Msg_NE 964 (Msg : String; 965 N : Node_Or_Entity_Id; 966 E : Node_Or_Entity_Id); 967 pragma Inline (SPARK_Msg_NE); 968 -- Same as Error_Msg_NE, but the error is suppressed if SPARK_Mode is Off. 969 -- The routine is inlined because it acts as a simple wrapper. 970 971 ------------------------------------------ 972 -- Utility Interface for Casing Control -- 973 ------------------------------------------ 974 975 procedure Adjust_Name_Case 976 (Buf : in out Bounded_String; 977 Loc : Source_Ptr); 978 -- Given a name stored in Buf, set proper casing. Loc is an associated 979 -- source position, and if we can find a match between the name in Buf and 980 -- the name at that source location, we copy the casing from the source, 981 -- otherwise we set appropriate default casing. 982 983 procedure Set_Identifier_Casing 984 (Identifier_Name : System.Address; 985 File_Name : System.Address); 986 pragma Convention (C, Set_Identifier_Casing); 987 -- This subprogram can be used by the back end for the purposes of 988 -- concocting error messages that are not output via Errout, e.g. 989 -- the messages generated by the gcc back end. 990 -- 991 -- The identifier is a null terminated string that represents the name of 992 -- an identifier appearing in the source program. File_Name is a null 993 -- terminated string giving the corresponding file name for the identifier 994 -- as obtained from the front end by the use of Full_Debug_Name to the 995 -- source file referenced by the corresponding source location value. On 996 -- return, the name is in Name_Buffer, null terminated with Name_Len set. 997 -- This name is the identifier name as passed, cased according to the 998 -- default identifier casing for the given file. 999 1000 -- WARNING: There is a matching C declaration of this subprogram in fe.h 1001 1002 function Is_Size_Too_Small_Message (S : String) return Boolean; 1003 Size_Too_Small_Message : constant String := 1004 "size for& too small, minimum allowed is ^"; 1005 -- This message is printed in Freeze and Sem_Ch13. We also test for it in 1006 -- the body of this package (see Special_Msg_Delete). 1007 -- Function Is_Size_Too_Small_Message tests for it by testing a prefix. 1008 -- The function and constant should be kept in synch. 1009 1010end Errout; 1011