1------------------------------------------------------------------------------ 2-- -- 3-- GNAT COMPILER COMPONENTS -- 4-- -- 5-- L I B . W R I T -- 6-- -- 7-- S p e c -- 8-- -- 9-- Copyright (C) 1992-2020, 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 for writing the library information 27 28package Lib.Writ is 29 30 ----------------------------------- 31 -- Format of Library Information -- 32 ----------------------------------- 33 34 -- This section describes the format of the library information that is 35 -- associated with object files. The exact method of this association is 36 -- potentially implementation dependent and is described and implemented in 37 -- package ali. From the point of view of the description here, all we need 38 -- to know is that the information is represented as a string of characters 39 -- that is somehow associated with an object file, and can be retrieved. If 40 -- no library information exists for a given object file, then we take this 41 -- as equivalent to the non-existence of the object file, as if source file 42 -- has not been previously compiled. 43 44 -- The library information is written as a series of lines of the form: 45 46 -- Key_Character parameter parameter ... 47 48 -- The following sections describe the format of these lines in detail 49 50 -------------------------------------- 51 -- Making Changes to the ALI Format -- 52 -------------------------------------- 53 54 -- A number of tools use ali.adb to parse ali files. This means that 55 -- changes to this format can cause old versions of these tools to be 56 -- incompatible with new versions of the compiler. Any changes to ali file 57 -- formats must be carefully evaluated to understand any such possible 58 -- conflicts, and in particular, it is very undesirable to create conflicts 59 -- between older versions of GNAT Studio and newer versions of the 60 -- compiler. 61 62 -- If the following guidelines are respected, downward compatibility 63 -- problems (old tools reading new ali files) should be minimized: 64 65 -- The basic key character format must be kept 66 67 -- The V line must be the first line, this is checked by ali.adb even in 68 -- Ignore_Errors mode, and is used to verify that the file at hand is 69 -- indeed likely intended to be an ali file. 70 71 -- The P line must be present, though may be modified in contents 72 -- according to remaining guidelines. Again, ali.adb assumes the P 73 -- line is present even in Ignore_Errors mode. 74 75 -- New modifiers can generally be added (in particular adding new two 76 -- letter modifiers to the P or U lines is always safe) 77 78 -- Adding entirely new lines (with a new key letter) to the ali file is 79 -- always safe, at any point (other than before the V line), since such 80 -- lines will be ignored. 81 82 -- Following the guidelines in this section should ensure that this problem 83 -- is minimized and that old tools will be able to deal successfully with 84 -- new ali formats. Note that this does not apply to the compiler itself, 85 -- which always requires consistency between the ali files and the binder. 86 -- That is because one of the main functions of the binder is to ensure 87 -- consistency of the partition, and this can be compromised if the ali 88 -- files are inconsistent. 89 90 ------------------ 91 -- Header Lines -- 92 ------------------ 93 94 -- The initial header lines in the file give information about the 95 -- compilation environment, and identify other special information such as 96 -- main program parameters. 97 98 -- ---------------- 99 -- -- V Version -- 100 -- ---------------- 101 102 -- V "xxxxxxxxxxxxxxxx" 103 -- 104 -- This line indicates the library output version, as defined in 105 -- Gnatvsn. It ensures that separate object modules of a program are 106 -- consistent. It has to be changed if anything changes which would 107 -- affect successful binding of separately compiled modules. Examples 108 -- of such changes are modifications in the format of the library info 109 -- described in this package, or modifications to calling sequences, or 110 -- to the way that data is represented. 111 112 -- Note: the V line absolutely must be the first line, and no change 113 -- to the ALI format should change this, since even in Ignore_Errors 114 -- mode, Scan_ALI insists on finding a V line. 115 116 -- --------------------- 117 -- -- M Main Program -- 118 -- --------------------- 119 120 -- M type [priority] [T=time-slice] [C=cpu] W=? 121 122 -- This line appears only if the main unit for this file is suitable 123 -- for use as a main program. The parameters are: 124 125 -- type 126 127 -- P for a parameterless procedure 128 -- F for a function returning a value of integral type 129 -- (used for writing a main program returning an exit status) 130 131 -- priority 132 133 -- Present only if there was a valid pragma Priority in the 134 -- corresponding unit to set the main task priority. It is an 135 -- unsigned decimal integer. 136 137 -- T=time-slice 138 139 -- Present only if there was a valid pragma Time_Slice in the 140 -- corresponding unit. It is an unsigned decimal integer in the 141 -- range 0 .. 10**9 giving the time slice value in units of 142 -- milliseconds. The actual significance of this parameter is 143 -- target dependent. 144 145 -- C=cpu 146 147 -- Present only if there was a valid pragma CPU in the 148 -- corresponding unit to set the main task affinity. It is an 149 -- unsigned decimal integer. 150 151 -- W=? 152 153 -- This parameter indicates the wide character encoding method used 154 -- when compiling the main program file. The ? character is the 155 -- single character used in the -gnatW? switch. This is used to 156 -- provide the default wide-character encoding for Wide_Text_IO 157 -- files. 158 159 -- ----------------- 160 -- -- A Argument -- 161 -- ----------------- 162 163 -- A argument 164 165 -- One of these lines appears for each of the arguments present in the 166 -- call to the gnat1 program. This can be used if it is necessary to 167 -- reconstruct this call (e.g. for fix and continue). 168 169 -- ------------------- 170 -- -- P Parameters -- 171 -- ------------------- 172 173 -- P <<parameters>> 174 175 -- Indicates various information that applies to the compilation of the 176 -- corresponding source file. Parameters is a sequence of zero or more 177 -- two letter codes that indicate configuration pragmas and other 178 -- parameters that apply: 179 180 -- The arguments are as follows: 181 182 -- CE Compilation errors. If this is present it means that the ali 183 -- file resulted from a compilation with the -gnatQ switch set, 184 -- and illegalities were detected. The ali file contents may 185 -- not be completely reliable, but the format will be correct 186 -- and complete. Note that NO is always present if CE is 187 -- present. 188 189 -- DB Detect_Blocking pragma is in effect for all units in this 190 -- file. 191 192 -- Ex A valid Partition_Elaboration_Policy pragma applies to all 193 -- the units in this file, where x is the first character 194 -- (upper case) of the policy name (e.g. 'C' for Concurrent). 195 196 -- FX Units in this file use front-end exceptions, with explicit 197 -- handlers to trigger AT-END actions on exception paths. 198 199 -- GP Set if this compilation was done in GNATprove mode, either 200 -- from direct use of GNATprove, or from use of -gnatdF. 201 202 -- Lx A valid Locking_Policy pragma applies to all the units in 203 -- this file, where x is the first character (upper case) of 204 -- the policy name (e.g. 'C' for Ceiling_Locking). 205 206 -- NO No object. This flag indicates that the units in this file 207 -- were not compiled to produce an object. This can occur as a 208 -- result of the use of -gnatc, or if no object can be produced 209 -- (e.g. when a package spec is compiled instead of the body, 210 -- or a subunit on its own). Note that in GNATprove mode, we 211 -- do produce an object. The object is not suitable for binding 212 -- and linking, but we do not set NO, instead we set GP. 213 214 -- NR No_Run_Time. Indicates that a pragma No_Run_Time applies 215 -- to all units in the file. 216 217 -- NS Normalize_Scalars pragma in effect for all units in 218 -- this file. 219 220 -- OH Pragma Default_Scalar_Storage_Order (High_Order_First) is 221 -- present in a configuration pragma file that applies. 222 223 -- OL Pragma Default_Scalar_Storage_Order (Low_Order_First) is 224 -- present in a configuration pragma file that applies. 225 226 -- Qx A valid Queueing_Policy pragma applies to all the units 227 -- in this file, where x is the first character (upper case) 228 -- of the policy name (e.g. 'P' for Priority_Queueing). 229 230 -- SL Indicates that the unit is an Interface to a Standalone 231 -- Library. Note that this indication is never given by the 232 -- compiler, but is added by the Project Manager in gnatmake 233 -- when an Interface ALI file is copied to the library 234 -- directory. 235 236 -- SS This unit references System.Secondary_Stack (that is, 237 -- the unit makes use of the secondary stack facilities). 238 239 -- Tx A valid Task_Dispatching_Policy pragma applies to all 240 -- the units in this file, where x is the first character 241 -- (upper case) of the corresponding policy name (e.g. 'F' 242 -- for FIFO_Within_Priorities). 243 244 -- UA Unreserve_All_Interrupts pragma was processed in one or 245 -- more units in this file 246 247 -- ZX Units in this file use zero-cost exceptions and have 248 -- generated exception tables. If ZX is not present, the 249 -- longjmp/setjmp exception scheme is in use. 250 251 -- Note that language defined units never output policy (Lx, Tx, Qx) 252 -- parameters. Language defined units must correctly handle all 253 -- possible cases. These values are checked for consistency by the 254 -- binder and then copied to the generated binder output file. 255 256 -- Note: The P line must be present. Even in Ignore_Errors mode, Scan_ALI 257 -- insists on finding a P line. So if changes are made to the ALI format, 258 -- they should not include removing the P line. 259 260 -- --------------------- 261 -- -- R Restrictions -- 262 -- --------------------- 263 264 -- There are two forms for R lines, positional and named. The positional 265 -- notation is now considered obsolescent, it is not generated by the most 266 -- recent versions of the compiler except under control of the debug switch 267 -- -gnatdR, but is still recognized by the binder. 268 269 -- The recognition by the binder is to ease the transition, and better deal 270 -- with some cases of inconsistent builds using incompatible versions of 271 -- the compiler and binder. The named notation is the current preferred 272 -- approach. 273 274 -- Note that R lines are generated using the information in unit Rident, 275 -- and intepreted by the binder using the information in System.Rident. 276 -- Normally these two units should be effectively identical. However in 277 -- some cases of inconsistent builds, they may be different. This may lead 278 -- to binder diagnostics, which can be suppressed using the -C switch for 279 -- the binder, which results in ignoring unrecognized restrictions in the 280 -- ali files. 281 282 -- --------------------------------------- 283 -- -- R Restrictions (Positional Form) -- 284 -- --------------------------------------- 285 286 -- The first R line records the status of restrictions generated by pragma 287 -- Restrictions encountered, as well as information on what the compiler 288 -- has been able to determine with respect to restrictions violations. 289 -- The format is: 290 291 -- R <<restriction-characters>> <<restriction-param-id-entries>> 292 293 -- The first parameter is a string of characters that records 294 -- information regarding restrictions that do not take parameter not 295 -- take parameter values. It is a string of characters, one character 296 -- for each value (in order) in All_Boolean_Restrictions. There are 297 -- three possible settings for each restriction: 298 299 -- r Restricted. Unit was compiled under control of a pragma 300 -- Restrictions for the corresponding restriction. In this case 301 -- the unit certainly does not violate the Restriction, since 302 -- this would have been detected by the compiler. 303 304 -- n Not used. The unit was not compiled under control of a pragma 305 -- Restrictions for the corresponding restriction, and does not 306 -- make any use of the referenced feature. 307 308 -- v Violated. The unit was not compiled under control of a pragma 309 -- Restrictions for the corresponding restriction, and it does 310 -- indeed use the referenced feature. 311 312 -- This information is used in the binder to check consistency, i.e. to 313 -- detect cases where one unit has "r" and another unit has "v", which 314 -- is not permitted, since these restrictions are partition-wide. 315 316 -- The second parameter, which immediately follows the first (with no 317 -- separating space) gives restriction information for identifiers for 318 -- which a parameter is given. 319 320 -- The parameter is a string of entries, one for each value in 321 -- Restrict.All_Parameter_Restrictions. Each entry has two components 322 -- in sequence, the first indicating whether or not there is a 323 -- restriction, and the second indicating whether or not the compiler 324 -- detected violations. In the boolean case it is not necessary to 325 -- separate these, since if a restriction is set, and violated, that is 326 -- an error. But in the parameter case, this is not true. For example, 327 -- we can have a unit with a pragma Restrictions (Max_Tasks => 4), 328 -- where the compiler can detect that there are exactly three tasks 329 -- declared. Both of these pieces of information must be passed to the 330 -- binder. The parameter of 4 is important in case the total number of 331 -- tasks in the partition is greater than 4. The parameter of 3 is 332 -- important in case some other unit has a restrictions pragma with 333 -- Max_Tasks=>2. 334 335 -- The component for the presence of restriction has one of two 336 -- possible forms: 337 338 -- n No pragma for this restriction is present in the set of units 339 -- for this ali file. 340 341 -- rN At least one pragma for this restriction is present in the 342 -- set of units for this ali file. The value N is the minimum 343 -- parameter value encountered in any such pragma. N is in the 344 -- range of Integer (a value larger than N'Last causes the 345 -- pragma to be ignored). 346 347 -- The component for the violation detection has one of three 348 -- possible forms: 349 350 -- n No violations were detected by the compiler 351 352 -- vN A violation was detected. N is either the maximum or total 353 -- count of violations (depending on the checking type) in all 354 -- the units represented by the ali file). Note that this 355 -- setting is only allowed for restrictions that are in 356 -- Checked_[Max|Sum]_Parameter_Restrictions. The value here is 357 -- known to be exact by the compiler and is in the range of 358 -- Natural. 359 360 -- vN+ A violation was detected. The compiler cannot determine 361 -- the exact count of violations, but it is at least N. 362 363 -- There are no spaces within the parameter string, so the entry 364 -- described above in the header of this section for Max_Tasks would 365 -- appear as the string r4v3. 366 367 -- Note: The restrictions line is required to be present. Even in 368 -- Ignore_Errors mode, Scan_ALI expects to find an R line and will 369 -- signal a fatal error if it is missing. This means that future 370 -- changes to the ALI file format must retain the R line. 371 372 -- ---------------------------------- 373 -- -- R Restrictions (Named Form) -- 374 -- ---------------------------------- 375 376 -- The first R line for named form announces that named notation will be 377 -- used, and also assures that there is at least one R line present, which 378 -- makes parsing of ali files simpler. A blank line preceds the RN line. 379 380 -- RN 381 382 -- In named notation, the restrictions are given as a series of lines, 383 -- one per restrictions that is specified or violated (no information is 384 -- present for restrictions that are not specified or violated). In the 385 -- following name is the name of the restriction in all upper case. 386 387 -- For boolean restrictions, we have only two possibilities. A restrictions 388 -- pragma is present, or a violation is detected: 389 390 -- RR name 391 392 -- A restriction pragma is present for the named boolean restriction. 393 -- No violations were detected by the compiler (or the unit in question 394 -- would have been found to be illegal). 395 396 -- RV name 397 398 -- No restriction pragma is present for the named boolean restriction. 399 -- However, the compiler did detect one or more violations of this 400 -- restriction, which may require a binder consistency check. Note that 401 -- one case of a violation is the use of a Restriction_Set attribute for 402 -- the restriction that yielded False. 403 404 -- For the case of restrictions that take a parameter, we need both the 405 -- information from pragma if present, and the actual information about 406 -- what possible violations occur. For example, we can have a unit with 407 -- a pragma Restrictions (Max_Tasks => 4), where the compiler can detect 408 -- that there are exactly three tasks declared. Both of these pieces 409 -- of information must be passed to the binder. The parameter of 4 is 410 -- important in case the total number of tasks in the partition is greater 411 -- than 4. The parameter of 3 is important in case some other unit has a 412 -- restrictions pragma with Max_Tasks=>2. 413 414 -- RR name=N 415 416 -- A restriction pragma is present for the named restriction which is 417 -- one of the restrictions taking a parameter. The value N (a decimal 418 -- integer) is the value given in the restriction pragma. 419 420 -- RV name=N 421 422 -- A restriction pragma may or may not be present for the restriction 423 -- given by name (one of the restrictions taking a parameter). But in 424 -- either case, the compiler detected possible violations. N (a decimal 425 -- integer) is the maximum or total count of violations (depending 426 -- on the checking type) in all the units represented by the ali file). 427 -- The value here is known to be exact by the compiler and is in the 428 -- range of Natural. Note that if an RR line is present for the same 429 -- restriction, then the value in the RV line cannot exceed the value 430 -- in the RR line (since otherwise the compiler would have detected a 431 -- violation of the restriction). 432 433 -- RV name=N+ 434 435 -- Similar to the above, but the compiler cannot determine the exact 436 -- count of violations, but it is at least N. 437 438 -- ------------------------------------------------- 439 -- -- R Restrictions (No_Dependence Information) -- 440 -- ------------------------------------------------- 441 442 -- Subsequent R lines are present only if pragma Restriction No_Dependence 443 -- is used. There is one such line for each such pragma appearing in the 444 -- extended main unit. The format is: 445 446 -- R unit_name 447 448 -- Here the unit name is in all lower case. The components of the unit 449 -- name are separated by periods. The names themselves are in encoded 450 -- form, as documented in Namet. 451 452 -- ------------------------- 453 -- -- I Interrupt States -- 454 -- ------------------------- 455 456 -- I interrupt-number interrupt-state line-number 457 458 -- This line records information from an Interrupt_State pragma. There 459 -- is one line for each separate pragma, and if no such pragmas are 460 -- used, then no I lines are present. 461 462 -- The interrupt-number is an unsigned positive integer giving the 463 -- value of the interrupt as defined in Ada.Interrupts.Names. 464 465 -- The interrupt-state is one of r/s/u for Runtime/System/User 466 467 -- The line number is an unsigned decimal integer giving the line 468 -- number of the corresponding Interrupt_State pragma. This is used 469 -- in consistency messages. 470 471 -- -------------------------------------- 472 -- -- S Priority Specific Dispatching -- 473 -- -------------------------------------- 474 475 -- S policy_identifier first_priority last_priority line-number 476 477 -- This line records information from a Priority_Specific_Dispatching 478 -- pragma. There is one line for each separate pragma, and if no such 479 -- pragmas are used, then no S lines are present. 480 481 -- The policy_identifier is the first character (upper case) of the 482 -- corresponding policy name (e.g. 'F' for FIFO_Within_Priorities). 483 484 -- The first_priority and last_priority fields define the range of 485 -- priorities to which the specified dispatching policy apply. 486 487 -- The line number is an unsigned decimal integer giving the line 488 -- number of the corresponding Priority_Specific_Dispatching pragma. 489 -- This is used in consistency messages. 490 491 ---------------------------- 492 -- Compilation Unit Lines -- 493 ---------------------------- 494 495 -- Following these header lines, a set of information lines appears for 496 -- each compilation unit that appears in the corresponding object file. In 497 -- particular, when a package body or subprogram body is compiled, there 498 -- will be two sets of information, one for the spec and one for the body, 499 -- with the entry for the body appearing first. This is the only case in 500 -- which a single ALI file contains more than one unit (in particular note 501 -- that subunits do *not* count as compilation units for this purpose, and 502 -- generate no library information, since they are inlined). 503 504 -- -------------------- 505 -- -- U Unit Header -- 506 -- -------------------- 507 508 -- The lines for each compilation unit have the following form 509 510 -- U unit-name source-name version <<attributes>> 511 512 -- This line identifies the unit to which this section of the library 513 -- information file applies. The first three parameters are the unit 514 -- name in internal format, as described in package Uname, and the name 515 -- of the source file containing the unit. 516 517 -- Version is the version given as eight hexadecimal characters with 518 -- upper case letters. This value is the exclusive or of the source 519 -- checksums of the unit and all its semantically dependent units. 520 521 -- The <<attributes>> are a series of two letter codes indicating 522 -- information about the unit: 523 524 -- BD Unit does not have pragma Elaborate_Body, but the elaboration 525 -- circuit has determined that it would be a good idea if this 526 -- pragma were present, since the body of the package contains 527 -- elaboration code that modifies one or more variables in the 528 -- visible part of the package. The binder will try, but does 529 -- not promise, to keep the elaboration of the body close to 530 -- the elaboration of the spec. 531 532 -- DE Dynamic Elaboration. This unit was compiled with the dynamic 533 -- elaboration model, as set by either the -gnatE switch or 534 -- pragma Elaboration_Checks (Dynamic). 535 -- 536 -- EB Unit has pragma Elaborate_Body, or is a generic instance that 537 -- has a body. Set for instances because RM 12.3(20) requires 538 -- that the body be immediately elaborated after the spec (we 539 -- would normally do that anyway, because elaborate spec and 540 -- body together whenever possible, and for an instance it is 541 -- always possible; however setting EB ensures that this is done 542 -- even when using the -p gnatbind switch). 543 544 -- EE Elaboration entity is present which must be set true when 545 -- the unit is elaborated. The name of the elaboration entity is 546 -- formed from the unit name in the usual way. If EE is present, 547 -- then this boolean must be set True as part of the elaboration 548 -- processing routine generated by the binder. Note that EE can 549 -- be set even if NE is set. This happens when the boolean is 550 -- needed solely for checking for the case of access before 551 -- elaboration. 552 553 -- GE Unit is a generic declaration, or corresponding body 554 -- 555 -- IL Unit source uses a style with identifiers in all lower-case 556 -- IU (IL) or all upper case (IU). If the standard mixed-case usage 557 -- is detected, or the compiler cannot determine the style, then 558 -- no I parameter will appear. 559 560 -- IS Initialize_Scalars pragma applies to this unit, or else there 561 -- is at least one use of the Invalid_Value attribute. 562 563 -- KM Unit source uses a style with keywords in mixed case (KM) 564 -- KU or all upper case (KU). If the standard lower-case usage is 565 -- is detected, or the compiler cannot determine the style, then 566 -- no K parameter will appear. 567 568 -- NE Unit has no elaboration routine. All subprogram bodies and 569 -- specs are in this category. Package bodies and specs may or 570 -- may not have NE set, depending on whether or not elaboration 571 -- code is required. Set if N_Compilation_Unit node has flag 572 -- Has_No_Elaboration_Code set. 573 574 -- OL The units in this file are compiled with a local pragma 575 -- Optimize_Alignment, so no consistency requirement applies 576 -- to these units. All internal units have this status since 577 -- they have an automatic default of Optimize_Alignment (Off). 578 -- 579 -- OO Optimize_Alignment (Off) is the default setting for all 580 -- units in this file. All files in the partition that specify 581 -- a default must specify the same default. 582 583 -- OS Optimize_Alignment (Space) is the default setting for all 584 -- units in this file. All files in the partition that specify 585 -- a default must specify the same default. 586 587 -- OT Optimize_Alignment (Time) is the default setting for all 588 -- units in this file. All files in the partition that specify 589 -- a default must specify the same default. 590 591 -- PF The unit has a library-level (package) finalizer 592 593 -- PK Unit is package, rather than a subprogram 594 595 -- PU Unit has pragma Pure 596 597 -- PR Unit has pragma Preelaborate 598 599 -- RA Unit declares a Remote Access to Class-Wide (RACW) type 600 601 -- RC Unit has pragma Remote_Call_Interface 602 603 -- RT Unit has pragma Remote_Types 604 605 -- SE Compilation of unit encountered one or more serious errors. 606 -- Normally the generation of an ALI file is suppressed if there 607 -- is a serious error, but this can be overridden with -gnatQ. 608 609 -- SP Unit has pragma Shared_Passive 610 611 -- SU Unit is a subprogram, rather than a package 612 613 -- The attributes may appear in any order, separated by spaces 614 615 -- ----------------------------- 616 -- -- W, Y and Z Withed Units -- 617 -- ----------------------------- 618 619 -- Following each U line, is a series of lines of the form 620 621 -- W unit-name [source-name lib-name] [E] [EA] [ED] [AD] 622 -- or 623 -- Y unit-name [source-name lib-name] [E] [EA] [ED] [AD] 624 -- or 625 -- Z unit-name [source-name lib-name] [E] [EA] [ED] [AD] 626 627 -- One W line is present for each unit that is mentioned in an explicit 628 -- nonlimited with clause by the current unit. One Y line is present 629 -- for each unit that is mentioned in an explicit limited with clause 630 -- by the current unit. One Z line is present for each unit that is 631 -- only implicitly withed by the current unit. The first parameter is 632 -- the unit name in internal format. The second parameter is the file 633 -- name of the file that must be compiled to compile this unit. It is 634 -- usually the file for the body, except for packages which have no 635 -- body. For units that need a body, if the source file for the body 636 -- cannot be found, the file name of the spec is used instead. The 637 -- third parameter is the file name of the library information file 638 -- that contains the results of compiling this unit. The optional 639 -- modifiers are used as follows: 640 641 -- E pragma Elaborate applies to this unit 642 643 -- EA pragma Elaborate_All applies to this unit 644 645 -- ED Elaborate_Desirable set for this unit, which means that there 646 -- is no Elaborate, but the analysis suggests that Program_Error 647 -- may be raised if the Elaborate conditions cannot be satisfied. 648 -- The binder will attempt to treat ED as E if it can. 649 650 -- AD Elaborate_All_Desirable set for this unit, which means that 651 -- there is no Elaborate_All, but the analysis suggests that 652 -- Program_Error may be raised if the Elaborate_All conditions 653 -- cannot be satisfied. The binder will attempt to treat AD as 654 -- EA if it can. 655 656 -- The parameter source-name and lib-name are omitted for the case of a 657 -- generic unit compiled with earlier versions of GNAT which did not 658 -- generate object or ali files for generics. For compatibility in the 659 -- bootstrap path we continue to omit these entries for predefined 660 -- generic units, even though we do now generate object and ali files. 661 662 -- However, in SPARK mode, we always generate source-name and lib-name 663 -- parameters. Bootstrap issues do not apply there, and we need this 664 -- information to properly compute frame conditions of subprograms. 665 666 -- The parameter source-name and lib-name are also omitted for the W 667 -- lines that result from use of a Restriction_Set attribute which gets 668 -- a result of False from a No_Dependence check, in the case where the 669 -- unit is not in the semantic closure. In such a case, the bare W 670 -- line is generated, but no D (dependency) line. This will make the 671 -- binder do the consistency check, but not include the unit in the 672 -- partition closure (unless it is properly With'ed somewhere). 673 674 -- -------------------- 675 -- -- T Task Stacks -- 676 -- -------------------- 677 678 -- Following the W lines (if any, or the U line if not), is an optional 679 -- line that identifies the number of default-sized primary and secondary 680 -- stacks that the binder needs to create for the tasks declared within the 681 -- unit. For each compilation unit, a line is present in the form: 682 683 -- T primary-stack-quantity secondary-stack-quantity 684 685 -- The first parameter of T defines the number of task objects declared 686 -- in the unit that have no Storage_Size specified. The second parameter 687 -- defines the number of task objects declared in the unit that have no 688 -- Secondary_Stack_Size specified. These values are non-zero only if 689 -- the restrictions No_Implicit_Heap_Allocations or 690 -- No_Implicit_Task_Allocations are active. 691 692 -- ----------------------- 693 -- -- L Linker_Options -- 694 -- ----------------------- 695 696 -- Following the T and W lines (if any, or the U line if not), are 697 -- an optional series of lines that indicates the usage of the pragma 698 -- Linker_Options in the associated unit. For each appearance of a pragma 699 -- Linker_Options (or Link_With) in the unit, a line is present with the 700 -- form: 701 702 -- L "string" 703 704 -- where string is the string from the unit line enclosed in quotes. 705 -- Within the quotes the following can occur: 706 707 -- c graphic characters in range 20-7E other than " or { 708 -- "" indicating a single " character 709 -- {hh} indicating a character whose code is hex hh (0-9,A-F) 710 -- {00} [ASCII.NUL] is used as a separator character 711 -- to separate multiple arguments of a single 712 -- Linker_Options pragma. 713 714 -- For further details, see Stringt.Write_String_Table_Entry. Note that 715 -- wide characters in the form {hhhh} cannot be produced, since pragma 716 -- Linker_Option accepts only String, not Wide_String. 717 718 -- The L lines are required to appear in the same order as the 719 -- corresponding Linker_Options (or Link_With) pragmas appear in the 720 -- source file, so that this order is preserved by the binder in 721 -- constructing the set of linker arguments. 722 723 -- Note: Linker_Options lines never appear in the ALI file generated for 724 -- a predefined generic unit, and there is cicuitry in Sem_Prag to enforce 725 -- this restriction, which is needed because of not generating source name 726 -- and lib name parameters on the with lines for such files, as explained 727 -- above in the section on with lines. 728 729 -- -------------- 730 -- -- N Notes -- 731 -- -------------- 732 733 -- The final section of unit-specific lines contains notes which record 734 -- annotations inserted in source code for processing by external tools 735 -- using pragmas. For each occurrence of any of these pragmas, a line is 736 -- generated with the following syntax: 737 738 -- N x<sloc> [<arg_id>:]<arg> ... 739 740 -- x is one of: 741 -- A pragma Annotate 742 -- C pragma Comment 743 -- I pragma Ident 744 -- T pragma Title 745 -- S pragma Subtitle 746 747 -- <sloc> is the source location of the pragma in line:col[:filename] 748 -- format. The file name is omitted if it is the same as the current 749 -- unit (it therefore appears explicitly in the case of pragmas 750 -- occurring in subunits, which do not have U sections of their own). 751 752 -- Successive entries record the pragma_argument_associations. 753 754 -- If a pragma argument identifier is present, the entry is prefixed 755 -- with the pragma argument identifier <arg_id> followed by a colon. 756 757 -- <arg> represents the pragma argument, and has the following 758 -- conventions: 759 760 -- - identifiers are output verbatim 761 -- - static string expressions are output as literals encoded as 762 -- for L lines 763 -- - static integer expressions are output as decimal literals 764 -- - any other expression is replaced by the placeholder "<expr>" 765 766 --------------------- 767 -- Reference Lines -- 768 --------------------- 769 770 -- The reference lines contain information about references from any of the 771 -- units in the compilation (including body version and version attributes, 772 -- linker options pragmas and source dependencies). 773 774 -- ------------------------------------ 775 -- -- E External Version References -- 776 -- ------------------------------------ 777 778 -- One of these lines is present for each use of 'Body_Version or 'Version 779 -- in any of the units of the compilation. These are used by the linker to 780 -- determine which version symbols must be output. The format is simply: 781 782 -- E name 783 784 -- where name is the external name, i.e. the unit name with either a S or a 785 -- B for spec or body version referenced (Body_Version always references 786 -- the body, Version references the Spec, except in the case of a reference 787 -- to a subprogram with no separate spec). Upper half and wide character 788 -- codes are encoded using the same method as in Namet (Uhh for upper half, 789 -- Whhhh for wide character, where hh are hex digits). 790 791 -- --------------------- 792 -- -- D Dependencies -- 793 -- --------------------- 794 795 -- The dependency lines indicate the source files on which the compiled 796 -- units depend. This is used by the binder for consistency checking. 797 -- These lines are also referenced by the cross-reference information. 798 799 -- D source-name time-stamp checksum (sub)unit-name line:file-name 800 801 -- source-name also includes preprocessing data file and preprocessing 802 -- definition file. These preprocessing files may be given as full 803 -- path names instead of simple file names. If a full path name 804 -- includes a directory with spaces, the path name is quoted (quote 805 -- characters (") added at start and end, and any internal quotes are 806 -- doubled). 807 808 -- The time-stamp field contains the time stamp of the corresponding 809 -- source file. See types.ads for details on time stamp representation. 810 811 -- The checksum is an 8-hex digit representation of the source file 812 -- checksum, with letters given in lower case. 813 814 -- If the unit is not a subunit, the (sub)unit name is the unit name in 815 -- internal format, as described in package Uname. If the unit is a 816 -- subunit, the (sub)unit name is the fully qualified name of the 817 -- subunit in all lower case letters. 818 819 -- The line:file-name entry is present only if a Source_Reference 820 -- pragma appeared in the source file identified by source-name. In 821 -- this case, it gives the information from this pragma. Note that this 822 -- allows cross-reference information to be related back to the 823 -- original file. Note: the reason the line number comes first is that 824 -- a leading digit immediately identifies this as a Source_Reference 825 -- entry, rather than a subunit-name. 826 827 -- A line number of zero for line: in this entry indicates that there 828 -- is more than one source reference pragma. In this case, the line 829 -- numbers in the cross-reference are correct, and refer to the 830 -- original line number, but there is no information that allows a 831 -- reader of the ALI file to determine the exact mapping of physical 832 -- line numbers back to the original source. 833 834 -- Files with a zero checksum and a non-zero time stamp are in general 835 -- files on which the compilation depends but which are not Ada files 836 -- with further dependencies. This includes preprocessor data files 837 -- and preprocessor definition files. 838 839 -- Note: blank lines are ignored when the library information is read, 840 -- and separate sections of the file are separated by blank lines to 841 -- ease readability. Blanks between fields are also ignored. 842 843 -- For entries corresponding to files that were not present (and thus 844 -- resulted in error messages), or for files that are not part of the 845 -- dependency set, both the time stamp and checksum are set to all zero 846 -- characters. These dummy entries are ignored by the binder in 847 -- dependency checking, but must be present for proper interpretation 848 -- of the cross-reference data. 849 850 -- ------------------------- 851 -- -- G Invocation Graph -- 852 -- ------------------------- 853 854 -- An invocation graph line has the following format: 855 -- 856 -- G line-kind line-attributes 857 -- 858 -- Attribute line-kind is a Character which denotes the nature of the 859 -- line. Table ALI.Invocation_Graph_Line_Codes lists all legal values. 860 -- 861 -- Attribute line-attributes depends on the value of line-kind, and is 862 -- contents are described further below. 863 -- 864 -- An invocation signature uniquely identifies an invocation construct in 865 -- the ALI file namespace, and has the following format: 866 -- 867 -- [ name scope line column (locations | "none") ] 868 -- 869 -- Attribute name is a String which denotes the name of the construct 870 -- 871 -- Attribute scope is a String which denotes the qualified name of the 872 -- scope where the construct is declared. 873 -- 874 -- Attribute line is a Positive which denotes the line number where the 875 -- initial declaration of the construct appears. 876 -- 877 -- Attribute column is a Positive which denotes the column number where 878 -- the initial declaration of the construct appears. 879 -- 880 -- Attribute locations is a String which denotes the line and column 881 -- locations of all instances where the initial declaration of the 882 -- construct appears. 883 -- 884 -- When the line-kind denotes invocation graph attributes, line-attributes 885 -- are set as follows: 886 -- 887 -- encoding-kind 888 -- 889 -- Attribute encoding-kind is a Character which specifies the encoding 890 -- kind used when collecting invocation constructs and relations. Table 891 -- ALI.Invocation_Graph_Encoding_Codes lists all legal values. 892 -- 893 -- When the line-kind denotes an invocation construct, line-attributes are 894 -- set as follows: 895 -- 896 -- construct-kind construct-spec-placement construct-body-placement 897 -- construct-signature 898 -- 899 -- Attribute construct-kind is a Character which denotes the nature of 900 -- the construct. Table ALI.Invocation_Construct_Codes lists all legal 901 -- values. 902 -- 903 -- Attribute construct-spec-placement is a Character which denotes the 904 -- placement of the construct's spec within the unit. All legal values 905 -- are listed in table ALI.Spec_And_Body_Placement_Codes. 906 -- 907 -- Attribute construct-body-placement is a Character which denotes the 908 -- placement of the construct's body within the unit. All legal values 909 -- are listed in table ALI.Spec_And_Body_Placement_Codes. 910 -- 911 -- Attribute construct-signature is the invocation signature of the 912 -- construct. 913 -- 914 -- When the line-kind denotes an invocation relation, line-attributes are 915 -- set as follows: 916 -- 917 -- relation-kind (extra-name | "none") invoker-signature 918 -- target-signature 919 -- 920 -- Attribute relation-kind is a Character which denotes the nature of 921 -- the relation. All legal values are listed in ALI.Invocation_Codes. 922 -- 923 -- Attribute extra-name is a String which denotes the name of an extra 924 -- entity used for error diagnostics. The value of extra-name depends 925 -- on the relation-kind as follows: 926 -- 927 -- Accept_Alternative - related entry 928 -- Access_Taken - related subprogram 929 -- Call - not present 930 -- Controlled_Adjustment - related controlled type 931 -- Controlled_Finalization - related controlled type 932 -- Controlled_Initialization - related controlled type 933 -- Default_Initial_Condition_Verification - related private type 934 -- Initial_Condition_Verification - not present 935 -- Instantiation - not present 936 -- Internal_Controlled_Adjustment - related controlled type 937 -- Internal_Controlled_Finalization - related controlled type 938 -- Internal_Controlled_Initialization - related controlled type 939 -- Invariant_Verification - related private type 940 -- Postcondition_Verification - related routine 941 -- Protected_Entry_Call - not present 942 -- Protected_Subprogram_Call - not present 943 -- Task_Activation - not present 944 -- Task_Entry_Call - not present 945 -- Type_Initialization - related type 946 -- 947 -- Attribute invoker-signature is the invocation signature of the 948 -- invoker. 949 -- 950 -- Attribute target-signature is the invocation signature of the target 951 952 -------------------------- 953 -- Cross-Reference Data -- 954 -------------------------- 955 956 -- The cross-reference data follows the dependency lines. See the spec of 957 -- Lib.Xref in file lib-xref.ads for details on the format of this data. 958 959 --------------------------------- 960 -- Source Coverage Obligations -- 961 --------------------------------- 962 963 -- The Source Coverage Obligation (SCO) information follows the cross- 964 -- reference data. See the spec of Par_SCO in file par_sco.ads for full 965 -- details of the format. 966 967 --------------------------------------- 968 -- SPARK Cross-Reference Information -- 969 --------------------------------------- 970 971 -- The SPARK cross-reference information follows the SCO information. See 972 -- the spec of SPARK_Xrefs in file spark_xrefs.ads for full details of the 973 -- format. 974 975 ------------------------------- 976 -- ALI File Generation for C -- 977 ------------------------------- 978 979 -- The C compiler can also generate ALI files for use by the IDE's in 980 -- providing navigation services in C. These ALI files are a subset of 981 -- the specification above, lacking all Ada-specific output. Primarily 982 -- the IDE uses the cross-reference sections of such files. 983 984 ---------------------- 985 -- Global Variables -- 986 ---------------------- 987 988 -- The table defined here stores one entry for each Interrupt_State pragma 989 -- encountered either in the main source or in an ancillary with'ed source. 990 -- Since interrupt state values have to be consistent across all units in a 991 -- partition, we detect inconsistencies at compile time when we can. 992 993 type Interrupt_State_Entry is record 994 Interrupt_Number : Pos; 995 -- Interrupt number value 996 997 Interrupt_State : Character; 998 -- Set to r/s/u for Runtime/System/User 999 1000 Pragma_Loc : Source_Ptr; 1001 -- Location of pragma setting this value in place 1002 end record; 1003 1004 package Interrupt_States is new Table.Table ( 1005 Table_Component_Type => Interrupt_State_Entry, 1006 Table_Index_Type => Nat, 1007 Table_Low_Bound => 1, 1008 Table_Initial => 30, 1009 Table_Increment => 200, 1010 Table_Name => "Name_Interrupt_States"); 1011 1012 -- The table structure defined here stores one entry for each 1013 -- Priority_Specific_Dispatching pragma encountered either in the main 1014 -- source or in an ancillary with'ed source. Since have to be consistent 1015 -- across all units in a partition, we may as well detect inconsistencies 1016 -- at compile time when we can. 1017 1018 type Specific_Dispatching_Entry is record 1019 Dispatching_Policy : Character; 1020 -- First character (upper case) of the corresponding policy name 1021 1022 First_Priority : Nat; 1023 -- Lower bound of the priority range to which the specified dispatching 1024 -- policy applies. 1025 1026 Last_Priority : Nat; 1027 -- Upper bound of the priority range to which the specified dispatching 1028 -- policy applies. 1029 1030 Pragma_Loc : Source_Ptr; 1031 -- Location of pragma setting this value in place 1032 end record; 1033 1034 package Specific_Dispatching is new Table.Table ( 1035 Table_Component_Type => Specific_Dispatching_Entry, 1036 Table_Index_Type => Nat, 1037 Table_Low_Bound => 1, 1038 Table_Initial => 10, 1039 Table_Increment => 100, 1040 Table_Name => "Name_Priority_Specific_Dispatching"); 1041 1042 ----------------- 1043 -- Subprograms -- 1044 ----------------- 1045 1046 procedure Ensure_System_Dependency; 1047 -- This procedure ensures that a dependency is created on system.ads. Even 1048 -- if there is no semantic dependency, Targparm has read the file to 1049 -- acquire target parameters, so we need a source dependency. 1050 1051 procedure Write_ALI (Object : Boolean); 1052 -- This procedure writes the library information for the current main unit 1053 -- The Object parameter is true if an object file is created, and false 1054 -- otherwise. Note that the pseudo-object file generated in GNATprove mode 1055 -- does count as an object file from this point of view. 1056 1057 procedure Add_Preprocessing_Dependency (S : Source_File_Index); 1058 -- Indicate that there is a dependency to be added on a preprocessing data 1059 -- file or on a preprocessing definition file. 1060 1061end Lib.Writ; 1062