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) 1992-2015, 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 GPS and newer versions of the compiler. 60 61 -- If the following guidelines are respected, downward compatibility 62 -- problems (old tools reading new ali files) should be minimized: 63 64 -- The basic key character format must be kept 65 66 -- The V line must be the first line, this is checked by ali.adb even in 67 -- Ignore_Errors mode, and is used to verify that the file at hand is 68 -- indeed likely intended to be an ali file. 69 70 -- The P line must be present, though may be modified in contents 71 -- according to remaining guidelines. Again, ali.adb assumes the P 72 -- line is present even in Ignore_Errors mode. 73 74 -- New modifiers can generally be added (in particular adding new two 75 -- letter modifiers to the P or U lines is always safe) 76 77 -- Adding entirely new lines (with a new key letter) to the ali file is 78 -- always safe, at any point (other than before the V line), since such 79 -- lines will be ignored. 80 81 -- Following the guidelines in this section should ensure that this problem 82 -- is minimized and that old tools will be able to deal successfully with 83 -- new ali formats. Note that this does not apply to the compiler itself, 84 -- which always requires consistency between the ali files and the binder. 85 -- That is because one of the main functions of the binder is to ensure 86 -- consistency of the partition, and this can be compromised if the ali 87 -- files are inconsistent. 88 89 ------------------ 90 -- Header Lines -- 91 ------------------ 92 93 -- The initial header lines in the file give information about the 94 -- compilation environment, and identify other special information such as 95 -- main program parameters. 96 97 -- ---------------- 98 -- -- V Version -- 99 -- ---------------- 100 101 -- V "xxxxxxxxxxxxxxxx" 102 -- 103 -- This line indicates the library output version, as defined in 104 -- Gnatvsn. It ensures that separate object modules of a program are 105 -- consistent. It has to be changed if anything changes which would 106 -- affect successful binding of separately compiled modules. Examples 107 -- of such changes are modifications in the format of the library info 108 -- described in this package, or modifications to calling sequences, or 109 -- to the way that data is represented. 110 111 -- Note: the V line absolutely must be the first line, and no change 112 -- to the ALI format should change this, since even in Ignore_Errors 113 -- mode, Scan_ALI insists on finding a V line. 114 115 -- --------------------- 116 -- -- M Main Program -- 117 -- --------------------- 118 119 -- M type [priority] [T=time-slice] [C=cpu] W=? 120 121 -- This line appears only if the main unit for this file is suitable 122 -- for use as a main program. The parameters are: 123 124 -- type 125 126 -- P for a parameterless procedure 127 -- F for a function returning a value of integral type 128 -- (used for writing a main program returning an exit status) 129 130 -- priority 131 132 -- Present only if there was a valid pragma Priority in the 133 -- corresponding unit to set the main task priority. It is an 134 -- unsigned decimal integer. 135 136 -- T=time-slice 137 138 -- Present only if there was a valid pragma Time_Slice in the 139 -- corresponding unit. It is an unsigned decimal integer in the 140 -- range 0 .. 10**9 giving the time slice value in units of 141 -- milliseconds. The actual significance of this parameter is 142 -- target dependent. 143 144 -- C=cpu 145 146 -- Present only if there was a valid pragma CPU in the 147 -- corresponding unit to set the main task affinity. It is an 148 -- unsigned decimal integer. 149 150 -- W=? 151 152 -- This parameter indicates the wide character encoding method used 153 -- when compiling the main program file. The ? character is the 154 -- single character used in the -gnatW? switch. This is used to 155 -- provide the default wide-character encoding for Wide_Text_IO 156 -- files. 157 158 -- ----------------- 159 -- -- A Argument -- 160 -- ----------------- 161 162 -- A argument 163 164 -- One of these lines appears for each of the arguments present in the 165 -- call to the gnat1 program. This can be used if it is necessary to 166 -- reconstruct this call (e.g. for fix and continue). 167 168 -- ------------------- 169 -- -- P Parameters -- 170 -- ------------------- 171 172 -- P <<parameters>> 173 174 -- Indicates various information that applies to the compilation of the 175 -- corresponding source file. Parameters is a sequence of zero or more 176 -- two letter codes that indicate configuration pragmas and other 177 -- parameters that apply: 178 179 -- The arguments are as follows: 180 181 -- CE Compilation errors. If this is present it means that the ali 182 -- file resulted from a compilation with the -gnatQ switch set, 183 -- and illegalities were detected. The ali file contents may 184 -- not be completely reliable, but the format will be correct 185 -- and complete. Note that NO is always present if CE is 186 -- present. 187 188 -- DB Detect_Blocking pragma is in effect for all units in this 189 -- file. 190 191 -- Ex A valid Partition_Elaboration_Policy pragma applies to all 192 -- the units in this file, where x is the first character 193 -- (upper case) of the policy name (e.g. 'C' for Concurrent). 194 195 -- FX Units in this file use front-end exceptions, with explicit 196 -- handlers to trigger AT-END actions on exception paths. 197 198 -- GP Set if this compilation was done in GNATprove mode, either 199 -- from direct use of GNATprove, or from use of -gnatdF. 200 201 -- Lx A valid Locking_Policy pragma applies to all the units in 202 -- this file, where x is the first character (upper case) of 203 -- the policy name (e.g. 'C' for Ceiling_Locking). 204 205 -- NO No object. This flag indicates that the units in this file 206 -- were not compiled to produce an object. This can occur as a 207 -- result of the use of -gnatc, or if no object can be produced 208 -- (e.g. when a package spec is compiled instead of the body, 209 -- or a subunit on its own). Note that in GNATprove mode, we 210 -- do produce an object. The object is not suitable for binding 211 -- and linking, but we do not set NO, instead we set GP. 212 213 -- NR No_Run_Time. Indicates that a pragma No_Run_Time applies 214 -- to all units in the file. 215 216 -- NS Normalize_Scalars pragma in effect for all units in 217 -- this file. 218 219 -- OH Pragma Default_Scalar_Storage_Order (High_Order_First) is 220 -- present in a configuration pragma file that applies. 221 222 -- OL Pragma Default_Scalar_Storage_Order (Low_Order_First) is 223 -- present in a configuration pragma file that applies. 224 225 -- Qx A valid Queueing_Policy pragma applies to all the units 226 -- in this file, where x is the first character (upper case) 227 -- of the policy name (e.g. 'P' for Priority_Queueing). 228 229 -- SL Indicates that the unit is an Interface to a Standalone 230 -- Library. Note that this indication is never given by the 231 -- compiler, but is added by the Project Manager in gnatmake 232 -- when an Interface ALI file is copied to the library 233 -- directory. 234 235 -- SS This unit references System.Secondary_Stack (that is, 236 -- the unit makes use of the secondary stack facilities). 237 238 -- Tx A valid Task_Dispatching_Policy pragma applies to all 239 -- the units in this file, where x is the first character 240 -- (upper case) of the corresponding policy name (e.g. 'F' 241 -- for FIFO_Within_Priorities). 242 243 -- UA Unreserve_All_Interrupts pragma was processed in one or 244 -- more units in this file 245 246 -- ZX Units in this file use zero-cost exceptions and have 247 -- generated exception tables. If ZX is not present, the 248 -- longjmp/setjmp exception scheme is in use. 249 250 -- Note that language defined units never output policy (Lx, Tx, Qx) 251 -- parameters. Language defined units must correctly handle all 252 -- possible cases. These values are checked for consistency by the 253 -- binder and then copied to the generated binder output file. 254 255 -- Note: The P line must be present. Even in Ignore_Errors mode, Scan_ALI 256 -- insists on finding a P line. So if changes are made to the ALI format, 257 -- they should not include removing the P line. 258 259 -- --------------------- 260 -- -- R Restrictions -- 261 -- --------------------- 262 263 -- There are two forms for R lines, positional and named. The positional 264 -- notation is now considered obsolescent, it is not generated by the most 265 -- recent versions of the compiler except under control of the debug switch 266 -- -gnatdR, but is still recognized by the binder. 267 268 -- The recognition by the binder is to ease the transition, and better deal 269 -- with some cases of inconsistent builds using incompatible versions of 270 -- the compiler and binder. The named notation is the current preferred 271 -- approach. 272 273 -- Note that R lines are generated using the information in unit Rident, 274 -- and intepreted by the binder using the information in System.Rident. 275 -- Normally these two units should be effectively identical. However in 276 -- some cases of inconsistent builds, they may be different. This may lead 277 -- to binder diagnostics, which can be suppressed using the -C switch for 278 -- the binder, which results in ignoring unrecognized restrictions in the 279 -- ali files. 280 281 -- --------------------------------------- 282 -- -- R Restrictions (Positional Form) -- 283 -- --------------------------------------- 284 285 -- The first R line records the status of restrictions generated by pragma 286 -- Restrictions encountered, as well as information on what the compiler 287 -- has been able to determine with respect to restrictions violations. 288 -- The format is: 289 290 -- R <<restriction-characters>> <<restriction-param-id-entries>> 291 292 -- The first parameter is a string of characters that records 293 -- information regarding restrictions that do not take parameter not 294 -- take parameter values. It is a string of characters, one character 295 -- for each value (in order) in All_Boolean_Restrictions. There are 296 -- three possible settings for each restriction: 297 298 -- r Restricted. Unit was compiled under control of a pragma 299 -- Restrictions for the corresponding restriction. In this case 300 -- the unit certainly does not violate the Restriction, since 301 -- this would have been detected by the compiler. 302 303 -- n Not used. The unit was not compiled under control of a pragma 304 -- Restrictions for the corresponding restriction, and does not 305 -- make any use of the referenced feature. 306 307 -- v Violated. The unit was not compiled under control of a pragma 308 -- Restrictions for the corresponding restriction, and it does 309 -- indeed use the referenced feature. 310 311 -- This information is used in the binder to check consistency, i.e. to 312 -- detect cases where one unit has "r" and another unit has "v", which 313 -- is not permitted, since these restrictions are partition-wide. 314 315 -- The second parameter, which immediately follows the first (with no 316 -- separating space) gives restriction information for identifiers for 317 -- which a parameter is given. 318 319 -- The parameter is a string of entries, one for each value in 320 -- Restrict.All_Parameter_Restrictions. Each entry has two components 321 -- in sequence, the first indicating whether or not there is a 322 -- restriction, and the second indicating whether or not the compiler 323 -- detected violations. In the boolean case it is not necessary to 324 -- separate these, since if a restriction is set, and violated, that is 325 -- an error. But in the parameter case, this is not true. For example, 326 -- we can have a unit with a pragma Restrictions (Max_Tasks => 4), 327 -- where the compiler can detect that there are exactly three tasks 328 -- declared. Both of these pieces of information must be passed to the 329 -- binder. The parameter of 4 is important in case the total number of 330 -- tasks in the partition is greater than 4. The parameter of 3 is 331 -- important in case some other unit has a restrictions pragma with 332 -- Max_Tasks=>2. 333 334 -- The component for the presence of restriction has one of two 335 -- possible forms: 336 337 -- n No pragma for this restriction is present in the set of units 338 -- for this ali file. 339 340 -- rN At least one pragma for this restriction is present in the 341 -- set of units for this ali file. The value N is the minimum 342 -- parameter value encountered in any such pragma. N is in the 343 -- range of Integer (a value larger than N'Last causes the 344 -- pragma to be ignored). 345 346 -- The component for the violation detection has one of three 347 -- possible forms: 348 349 -- n No violations were detected by the compiler 350 351 -- vN A violation was detected. N is either the maximum or total 352 -- count of violations (depending on the checking type) in all 353 -- the units represented by the ali file). Note that this 354 -- setting is only allowed for restrictions that are in 355 -- Checked_[Max|Sum]_Parameter_Restrictions. The value here is 356 -- known to be exact by the compiler and is in the range of 357 -- Natural. 358 359 -- vN+ A violation was detected. The compiler cannot determine 360 -- the exact count of violations, but it is at least N. 361 362 -- There are no spaces within the parameter string, so the entry 363 -- described above in the header of this section for Max_Tasks would 364 -- appear as the string r4v3. 365 366 -- Note: The restrictions line is required to be present. Even in 367 -- Ignore_Errors mode, Scan_ALI expects to find an R line and will 368 -- signal a fatal error if it is missing. This means that future 369 -- changes to the ALI file format must retain the R line. 370 371 -- ---------------------------------- 372 -- -- R Restrictions (Named Form) -- 373 -- ---------------------------------- 374 375 -- The first R line for named form announces that named notation will be 376 -- used, and also assures that there is at least one R line present, which 377 -- makes parsing of ali files simpler. A blank line preceds the RN line. 378 379 -- RN 380 381 -- In named notation, the restrictions are given as a series of lines, 382 -- one per restrictions that is specified or violated (no information is 383 -- present for restrictions that are not specified or violated). In the 384 -- following name is the name of the restriction in all upper case. 385 386 -- For boolean restrictions, we have only two possibilities. A restrictions 387 -- pragma is present, or a violation is detected: 388 389 -- RR name 390 391 -- A restriction pragma is present for the named boolean restriction. 392 -- No violations were detected by the compiler (or the unit in question 393 -- would have been found to be illegal). 394 395 -- RV name 396 397 -- No restriction pragma is present for the named boolean restriction. 398 -- However, the compiler did detect one or more violations of this 399 -- restriction, which may require a binder consistency check. Note that 400 -- one case of a violation is the use of a Restriction_Set attribute for 401 -- the restriction that yielded False. 402 403 -- For the case of restrictions that take a parameter, we need both the 404 -- information from pragma if present, and the actual information about 405 -- what possible violations occur. For example, we can have a unit with 406 -- a pragma Restrictions (Max_Tasks => 4), where the compiler can detect 407 -- that there are exactly three tasks declared. Both of these pieces 408 -- of information must be passed to the binder. The parameter of 4 is 409 -- important in case the total number of tasks in the partition is greater 410 -- than 4. The parameter of 3 is important in case some other unit has a 411 -- restrictions pragma with Max_Tasks=>2. 412 413 -- RR name=N 414 415 -- A restriction pragma is present for the named restriction which is 416 -- one of the restrictions taking a parameter. The value N (a decimal 417 -- integer) is the value given in the restriction pragma. 418 419 -- RV name=N 420 421 -- A restriction pragma may or may not be present for the restriction 422 -- given by name (one of the restrictions taking a parameter). But in 423 -- either case, the compiler detected possible violations. N (a decimal 424 -- integer) is the maximum or total count of violations (depending 425 -- on the checking type) in all the units represented by the ali file). 426 -- The value here is known to be exact by the compiler and is in the 427 -- range of Natural. Note that if an RR line is present for the same 428 -- restriction, then the value in the RV line cannot exceed the value 429 -- in the RR line (since otherwise the compiler would have detected a 430 -- violation of the restriction). 431 432 -- RV name=N+ 433 434 -- Similar to the above, but the compiler cannot determine the exact 435 -- count of violations, but it is at least N. 436 437 -- ------------------------------------------------- 438 -- -- R Restrictions (No_Dependence Information) -- 439 -- ------------------------------------------------- 440 441 -- Subsequent R lines are present only if pragma Restriction No_Dependence 442 -- is used. There is one such line for each such pragma appearing in the 443 -- extended main unit. The format is: 444 445 -- R unit_name 446 447 -- Here the unit name is in all lower case. The components of the unit 448 -- name are separated by periods. The names themselves are in encoded 449 -- form, as documented in Namet. 450 451 -- ------------------------- 452 -- -- I Interrupt States -- 453 -- ------------------------- 454 455 -- I interrupt-number interrupt-state line-number 456 457 -- This line records information from an Interrupt_State pragma. There 458 -- is one line for each separate pragma, and if no such pragmas are 459 -- used, then no I lines are present. 460 461 -- The interrupt-number is an unsigned positive integer giving the 462 -- value of the interrupt as defined in Ada.Interrupts.Names. 463 464 -- The interrupt-state is one of r/s/u for Runtime/System/User 465 466 -- The line number is an unsigned decimal integer giving the line 467 -- number of the corresponding Interrupt_State pragma. This is used 468 -- in consistency messages. 469 470 -- -------------------------------------- 471 -- -- S Priority Specific Dispatching -- 472 -- -------------------------------------- 473 474 -- S policy_identifier first_priority last_priority line-number 475 476 -- This line records information from a Priority_Specific_Dispatching 477 -- pragma. There is one line for each separate pragma, and if no such 478 -- pragmas are used, then no S lines are present. 479 480 -- The policy_identifier is the first character (upper case) of the 481 -- corresponding policy name (e.g. 'F' for FIFO_Within_Priorities). 482 483 -- The first_priority and last_priority fields define the range of 484 -- priorities to which the specified dispatching policy apply. 485 486 -- The line number is an unsigned decimal integer giving the line 487 -- number of the corresponding Priority_Specific_Dispatching pragma. 488 -- This is used in consistency messages. 489 490 ---------------------------- 491 -- Compilation Unit Lines -- 492 ---------------------------- 493 494 -- Following these header lines, a set of information lines appears for 495 -- each compilation unit that appears in the corresponding object file. In 496 -- particular, when a package body or subprogram body is compiled, there 497 -- will be two sets of information, one for the spec and one for the body, 498 -- with the entry for the body appearing first. This is the only case in 499 -- which a single ALI file contains more than one unit (in particular note 500 -- that subunits do *not* count as compilation units for this purpose, and 501 -- generate no library information, since they are inlined). 502 503 -- -------------------- 504 -- -- U Unit Header -- 505 -- -------------------- 506 507 -- The lines for each compilation unit have the following form 508 509 -- U unit-name source-name version <<attributes>> 510 511 -- This line identifies the unit to which this section of the library 512 -- information file applies. The first three parameters are the unit 513 -- name in internal format, as described in package Uname, and the name 514 -- of the source file containing the unit. 515 516 -- Version is the version given as eight hexadecimal characters with 517 -- upper case letters. This value is the exclusive or of the source 518 -- checksums of the unit and all its semantically dependent units. 519 520 -- The <<attributes>> are a series of two letter codes indicating 521 -- information about the unit: 522 523 -- BD Unit does not have pragma Elaborate_Body, but the elaboration 524 -- circuit has determined that it would be a good idea if this 525 -- pragma were present, since the body of the package contains 526 -- elaboration code that modifies one or more variables in the 527 -- visible part of the package. The binder will try, but does 528 -- not promise, to keep the elaboration of the body close to 529 -- the elaboration of the spec. 530 531 -- DE Dynamic Elaboration. This unit was compiled with the dynamic 532 -- elaboration model, as set by either the -gnatE switch or 533 -- pragma Elaboration_Checks (Dynamic). 534 -- 535 -- EB Unit has pragma Elaborate_Body, or is a generic instance that 536 -- has a body. Set for instances because RM 12.3(20) requires 537 -- that the body be immediately elaborated after the spec (we 538 -- would normally do that anyway, because elaborate spec and 539 -- body together whenever possible, and for an instance it is 540 -- always possible; however setting EB ensures that this is done 541 -- even when using the -p gnatbind switch). 542 543 -- EE Elaboration entity is present which must be set true when 544 -- the unit is elaborated. The name of the elaboration entity is 545 -- formed from the unit name in the usual way. If EE is present, 546 -- then this boolean must be set True as part of the elaboration 547 -- processing routine generated by the binder. Note that EE can 548 -- be set even if NE is set. This happens when the boolean is 549 -- needed solely for checking for the case of access before 550 -- elaboration. 551 552 -- GE Unit is a generic declaration, or corresponding body 553 -- 554 -- IL Unit source uses a style with identifiers in all lower-case 555 -- IU (IL) or all upper case (IU). If the standard mixed-case usage 556 -- is detected, or the compiler cannot determine the style, then 557 -- no I parameter will appear. 558 559 -- IS Initialize_Scalars pragma applies to this unit, or else there 560 -- is at least one use of the Invalid_Value attribute. 561 562 -- KM Unit source uses a style with keywords in mixed case (KM) 563 -- KU or all upper case (KU). If the standard lower-case usage is 564 -- is detected, or the compiler cannot determine the style, then 565 -- no K parameter will appear. 566 567 -- NE Unit has no elaboration routine. All subprogram bodies and 568 -- specs are in this category. Package bodies and specs may or 569 -- may not have NE set, depending on whether or not elaboration 570 -- code is required. Set if N_Compilation_Unit node has flag 571 -- Has_No_Elaboration_Code set. 572 573 -- OL The units in this file are compiled with a local pragma 574 -- Optimize_Alignment, so no consistency requirement applies 575 -- to these units. All internal units have this status since 576 -- they have an automatic default of Optimize_Alignment (Off). 577 -- 578 -- OO Optimize_Alignment (Off) is the default setting for all 579 -- units in this file. All files in the partition that specify 580 -- a default must specify the same default. 581 582 -- OS Optimize_Alignment (Space) is the default setting for all 583 -- units in this file. All files in the partition that specify 584 -- a default must specify the same default. 585 586 -- OT Optimize_Alignment (Time) is the default setting for all 587 -- units in this file. All files in the partition that specify 588 -- a default must specify the same default. 589 590 -- PF The unit has a library-level (package) finalizer 591 592 -- PK Unit is package, rather than a subprogram 593 594 -- PU Unit has pragma Pure 595 596 -- PR Unit has pragma Preelaborate 597 598 -- RA Unit declares a Remote Access to Class-Wide (RACW) type 599 600 -- RC Unit has pragma Remote_Call_Interface 601 602 -- RT Unit has pragma Remote_Types 603 604 -- SE Compilation of unit encountered one or more serious errors. 605 -- Normally the generation of an ALI file is suppressed if there 606 -- is a serious error, but this can be overridden with -gnatQ. 607 608 -- SP Unit has pragma Shared_Passive 609 610 -- SU Unit is a subprogram, rather than a package 611 612 -- The attributes may appear in any order, separated by spaces 613 614 -- ----------------------------- 615 -- -- W, Y and Z Withed Units -- 616 -- ----------------------------- 617 618 -- Following each U line, is a series of lines of the form 619 620 -- W unit-name [source-name lib-name] [E] [EA] [ED] [AD] 621 -- or 622 -- Y unit-name [source-name lib-name] [E] [EA] [ED] [AD] 623 -- or 624 -- Z unit-name [source-name lib-name] [E] [EA] [ED] [AD] 625 626 -- One W line is present for each unit that is mentioned in an explicit 627 -- non-limited with clause by the current unit. One Y line is present 628 -- for each unit that is mentioned in an explicit limited with clause 629 -- by the current unit. One Z line is present for each unit that is 630 -- only implicitly withed by the current unit. The first parameter is 631 -- the unit name in internal format. The second parameter is the file 632 -- name of the file that must be compiled to compile this unit. It is 633 -- usually the file for the body, except for packages which have no 634 -- body. For units that need a body, if the source file for the body 635 -- cannot be found, the file name of the spec is used instead. The 636 -- third parameter is the file name of the library information file 637 -- that contains the results of compiling this unit. The optional 638 -- modifiers are used as follows: 639 640 -- E pragma Elaborate applies to this unit 641 642 -- EA pragma Elaborate_All applies to this unit 643 644 -- ED Elaborate_Desirable set for this unit, which means that there 645 -- is no Elaborate, but the analysis suggests that Program_Error 646 -- may be raised if the Elaborate conditions cannot be satisfied. 647 -- The binder will attempt to treat ED as E if it can. 648 649 -- AD Elaborate_All_Desirable set for this unit, which means that 650 -- there is no Elaborate_All, but the analysis suggests that 651 -- Program_Error may be raised if the Elaborate_All conditions 652 -- cannot be satisfied. The binder will attempt to treat AD as 653 -- EA if it can. 654 655 -- The parameter source-name and lib-name are omitted for the case of a 656 -- generic unit compiled with earlier versions of GNAT which did not 657 -- generate object or ali files for generics. For compatibility in the 658 -- bootstrap path we continue to omit these entries for predefined 659 -- generic units, even though we do now generate object and ali files. 660 661 -- However, in SPARK mode, we always generate source-name and lib-name 662 -- parameters. Bootstrap issues do not apply there, and we need this 663 -- information to properly compute frame conditions of subprograms. 664 665 -- The parameter source-name and lib-name are also omitted for the W 666 -- lines that result from use of a Restriction_Set attribute which gets 667 -- a result of False from a No_Dependence check, in the case where the 668 -- unit is not in the semantic closure. In such a case, the bare W 669 -- line is generated, but no D (dependency) line. This will make the 670 -- binder do the consistency check, but not include the unit in the 671 -- partition closure (unless it is properly With'ed somewhere). 672 673 -- ----------------------- 674 -- -- L Linker_Options -- 675 -- ----------------------- 676 677 -- Following the W lines (if any, or the U line if not), are an optional 678 -- series of lines that indicates the usage of the pragma Linker_Options in 679 -- the associated unit. For each appearance of a pragma Linker_Options (or 680 -- Link_With) in the unit, a line is present with the form: 681 682 -- L "string" 683 684 -- where string is the string from the unit line enclosed in quotes. 685 -- Within the quotes the following can occur: 686 687 -- c graphic characters in range 20-7E other than " or { 688 -- "" indicating a single " character 689 -- {hh} indicating a character whose code is hex hh (0-9,A-F) 690 -- {00} [ASCII.NUL] is used as a separator character 691 -- to separate multiple arguments of a single 692 -- Linker_Options pragma. 693 694 -- For further details, see Stringt.Write_String_Table_Entry. Note that 695 -- wide characters in the form {hhhh} cannot be produced, since pragma 696 -- Linker_Option accepts only String, not Wide_String. 697 698 -- The L lines are required to appear in the same order as the 699 -- corresponding Linker_Options (or Link_With) pragmas appear in the 700 -- source file, so that this order is preserved by the binder in 701 -- constructing the set of linker arguments. 702 703 -- Note: Linker_Options lines never appear in the ALI file generated for 704 -- a predefined generic unit, and there is cicuitry in Sem_Prag to enforce 705 -- this restriction, which is needed because of not generating source name 706 -- and lib name parameters on the with lines for such files, as explained 707 -- above in the section on with lines. 708 709 -- -------------- 710 -- -- N Notes -- 711 -- -------------- 712 713 -- The final section of unit-specific lines contains notes which record 714 -- annotations inserted in source code for processing by external tools 715 -- using pragmas. For each occurrence of any of these pragmas, a line is 716 -- generated with the following syntax: 717 718 -- N x<sloc> [<arg_id>:]<arg> ... 719 720 -- x is one of: 721 -- A pragma Annotate 722 -- C pragma Comment 723 -- I pragma Ident 724 -- T pragma Title 725 -- S pragma Subtitle 726 727 -- <sloc> is the source location of the pragma in line:col[:filename] 728 -- format. The file name is omitted if it is the same as the current 729 -- unit (it therefore appears explicitly in the case of pragmas 730 -- occurring in subunits, which do not have U sections of their own). 731 732 -- Successive entries record the pragma_argument_associations. 733 734 -- If a pragma argument identifier is present, the entry is prefixed 735 -- with the pragma argument identifier <arg_id> followed by a colon. 736 737 -- <arg> represents the pragma argument, and has the following 738 -- conventions: 739 740 -- - identifiers are output verbatim 741 -- - static string expressions are output as literals encoded as 742 -- for L lines 743 -- - static integer expressions are output as decimal literals 744 -- - any other expression is replaced by the placeholder "<expr>" 745 746 --------------------- 747 -- Reference Lines -- 748 --------------------- 749 750 -- The reference lines contain information about references from any of the 751 -- units in the compilation (including body version and version attributes, 752 -- linker options pragmas and source dependencies). 753 754 -- ------------------------------------ 755 -- -- E External Version References -- 756 -- ------------------------------------ 757 758 -- One of these lines is present for each use of 'Body_Version or 'Version 759 -- in any of the units of the compilation. These are used by the linker to 760 -- determine which version symbols must be output. The format is simply: 761 762 -- E name 763 764 -- where name is the external name, i.e. the unit name with either a S or a 765 -- B for spec or body version referenced (Body_Version always references 766 -- the body, Version references the Spec, except in the case of a reference 767 -- to a subprogram with no separate spec). Upper half and wide character 768 -- codes are encoded using the same method as in Namet (Uhh for upper half, 769 -- Whhhh for wide character, where hh are hex digits). 770 771 -- --------------------- 772 -- -- D Dependencies -- 773 -- --------------------- 774 775 -- The dependency lines indicate the source files on which the compiled 776 -- units depend. This is used by the binder for consistency checking. 777 -- These lines are also referenced by the cross-reference information. 778 779 -- D source-name time-stamp checksum (sub)unit-name line:file-name 780 781 -- source-name also includes preprocessing data file and preprocessing 782 -- definition file. These preprocessing files may be given as full 783 -- path names instead of simple file names. If a full path name 784 -- includes a directory with spaces, the path name is quoted (quote 785 -- characters (") added at start and end, and any internal quotes are 786 -- doubled). 787 788 -- The time-stamp field contains the time stamp of the corresponding 789 -- source file. See types.ads for details on time stamp representation. 790 791 -- The checksum is an 8-hex digit representation of the source file 792 -- checksum, with letters given in lower case. 793 794 -- If the unit is not a subunit, the (sub)unit name is the unit name in 795 -- internal format, as described in package Uname. If the unit is a 796 -- subunit, the (sub)unit name is the fully qualified name of the 797 -- subunit in all lower case letters. 798 799 -- The line:file-name entry is present only if a Source_Reference 800 -- pragma appeared in the source file identified by source-name. In 801 -- this case, it gives the information from this pragma. Note that this 802 -- allows cross-reference information to be related back to the 803 -- original file. Note: the reason the line number comes first is that 804 -- a leading digit immediately identifies this as a Source_Reference 805 -- entry, rather than a subunit-name. 806 807 -- A line number of zero for line: in this entry indicates that there 808 -- is more than one source reference pragma. In this case, the line 809 -- numbers in the cross-reference are correct, and refer to the 810 -- original line number, but there is no information that allows a 811 -- reader of the ALI file to determine the exact mapping of physical 812 -- line numbers back to the original source. 813 814 -- Files with a zero checksum and a non-zero time stamp are in general 815 -- files on which the compilation depends but which are not Ada files 816 -- with further dependencies. This includes preprocessor data files 817 -- and preprocessor definition files. 818 819 -- Note: blank lines are ignored when the library information is read, 820 -- and separate sections of the file are separated by blank lines to 821 -- ease readability. Blanks between fields are also ignored. 822 823 -- For entries corresponding to files that were not present (and thus 824 -- resulted in error messages), or for files that are not part of the 825 -- dependency set, both the time stamp and checksum are set to all zero 826 -- characters. These dummy entries are ignored by the binder in 827 -- dependency checking, but must be present for proper interpretation 828 -- of the cross-reference data. 829 830 -------------------------- 831 -- Cross-Reference Data -- 832 -------------------------- 833 834 -- The cross-reference data follows the dependency lines. See the spec of 835 -- Lib.Xref in file lib-xref.ads for details on the format of this data. 836 837 --------------------------------- 838 -- Source Coverage Obligations -- 839 --------------------------------- 840 841 -- The Source Coverage Obligation (SCO) information follows the cross- 842 -- reference data. See the spec of Par_SCO in file par_sco.ads for full 843 -- details of the format. 844 845 --------------------------------------- 846 -- SPARK Cross-Reference Information -- 847 --------------------------------------- 848 849 -- The SPARK cross-reference information follows the SCO information. See 850 -- the spec of SPARK_Xrefs in file spark_xrefs.ads for full details of the 851 -- format. 852 853 ------------------------------- 854 -- ALI File Generation for C -- 855 ------------------------------- 856 857 -- The C compiler can also generate ALI files for use by the IDE's in 858 -- providing navigation services in C. These ALI files are a subset of 859 -- the specification above, lacking all Ada-specific output. Primarily 860 -- the IDE uses the cross-reference sections of such files. 861 862 ---------------------- 863 -- Global Variables -- 864 ---------------------- 865 866 -- The table defined here stores one entry for each Interrupt_State pragma 867 -- encountered either in the main source or in an ancillary with'ed source. 868 -- Since interrupt state values have to be consistent across all units in a 869 -- partition, we detect inconsistencies at compile time when we can. 870 871 type Interrupt_State_Entry is record 872 Interrupt_Number : Pos; 873 -- Interrupt number value 874 875 Interrupt_State : Character; 876 -- Set to r/s/u for Runtime/System/User 877 878 Pragma_Loc : Source_Ptr; 879 -- Location of pragma setting this value in place 880 end record; 881 882 package Interrupt_States is new Table.Table ( 883 Table_Component_Type => Interrupt_State_Entry, 884 Table_Index_Type => Nat, 885 Table_Low_Bound => 1, 886 Table_Initial => 30, 887 Table_Increment => 200, 888 Table_Name => "Name_Interrupt_States"); 889 890 -- The table structure defined here stores one entry for each 891 -- Priority_Specific_Dispatching pragma encountered either in the main 892 -- source or in an ancillary with'ed source. Since have to be consistent 893 -- across all units in a partition, we may as well detect inconsistencies 894 -- at compile time when we can. 895 896 type Specific_Dispatching_Entry is record 897 Dispatching_Policy : Character; 898 -- First character (upper case) of the corresponding policy name 899 900 First_Priority : Nat; 901 -- Lower bound of the priority range to which the specified dispatching 902 -- policy applies. 903 904 Last_Priority : Nat; 905 -- Upper bound of the priority range to which the specified dispatching 906 -- policy applies. 907 908 Pragma_Loc : Source_Ptr; 909 -- Location of pragma setting this value in place 910 end record; 911 912 package Specific_Dispatching is new Table.Table ( 913 Table_Component_Type => Specific_Dispatching_Entry, 914 Table_Index_Type => Nat, 915 Table_Low_Bound => 1, 916 Table_Initial => 10, 917 Table_Increment => 100, 918 Table_Name => "Name_Priority_Specific_Dispatching"); 919 920 ----------------- 921 -- Subprograms -- 922 ----------------- 923 924 procedure Ensure_System_Dependency; 925 -- This procedure ensures that a dependency is created on system.ads. Even 926 -- if there is no semantic dependency, Targparm has read the file to 927 -- acquire target parameters, so we need a source dependency. 928 929 procedure Write_ALI (Object : Boolean); 930 -- This procedure writes the library information for the current main unit 931 -- The Object parameter is true if an object file is created, and false 932 -- otherwise. Note that the pseudo-object file generated in GNATProve mode 933 -- does count as an object file from this point of view. 934 -- 935 -- Note: in the case where we are not generating code (-gnatc mode), this 936 -- routine only writes an ALI file if it cannot find an existing up to 937 -- date ALI file. If it *can* find an existing up to date ALI file, then 938 -- it reads this file and sets the Lib.Compilation_Arguments table from 939 -- the A lines in this file. 940 941 procedure Add_Preprocessing_Dependency (S : Source_File_Index); 942 -- Indicate that there is a dependency to be added on a preprocessing data 943 -- file or on a preprocessing definition file. 944 945end Lib.Writ; 946