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) 1992-2012, 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] [AB] [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 -- AB 145 146 -- Present if there is an allocator in the body of the procedure 147 -- after the BEGIN. This will be a violation of the restriction 148 -- No_Allocators_After_Elaboration if it is present, and this 149 -- unit is used as a main program (only the binder can find the 150 -- violation, since only the binder knows the main program). 151 152 -- C=cpu 153 154 -- Present only if there was a valid pragma CPU in the 155 -- corresponding unit to set the main task affinity. It is an 156 -- unsigned decimal integer. 157 158 -- W=? 159 160 -- This parameter indicates the wide character encoding method used 161 -- when compiling the main program file. The ? character is the 162 -- single character used in the -gnatW? switch. This is used to 163 -- provide the default wide-character encoding for Wide_Text_IO 164 -- files. 165 166 -- ----------------- 167 -- -- A Argument -- 168 -- ----------------- 169 170 -- A argument 171 172 -- One of these lines appears for each of the arguments present in the 173 -- call to the gnat1 program. This can be used if it is necessary to 174 -- reconstruct this call (e.g. for fix and continue). 175 176 -- ------------------- 177 -- -- P Parameters -- 178 -- ------------------- 179 180 -- P <<parameters>> 181 182 -- Indicates various information that applies to the compilation of the 183 -- corresponding source file. Parameters is a sequence of zero or more 184 -- two letter codes that indicate configuration pragmas and other 185 -- parameters that apply: 186 -- 187 -- The arguments are as follows: 188 -- 189 -- CE Compilation errors. If this is present it means that the ali 190 -- file resulted from a compilation with the -gnatQ switch set, 191 -- and illegalities were detected. The ali file contents may 192 -- not be completely reliable, but the format will be correct 193 -- and complete. Note that NO is always present if CE is 194 -- present. 195 -- 196 -- DB Detect_Blocking pragma is in effect for all units in this 197 -- file. 198 -- 199 -- Ex A valid Partition_Elaboration_Policy pragma applies to all 200 -- the units in this file, where x is the first character 201 -- (upper case) of the policy name (e.g. 'C' for Concurrent). 202 -- 203 -- FD Configuration pragmas apply to all the units in this file 204 -- specifying a possibly non-standard floating point format 205 -- (VAX float with Long_Float using D_Float). 206 -- 207 -- FG Configuration pragmas apply to all the units in this file 208 -- specifying a possibly non-standard floating point format 209 -- (VAX float with Long_Float using G_Float). 210 -- 211 -- FI Configuration pragmas apply to all the units in this file 212 -- specifying a possibly non-standard floating point format 213 -- (IEEE Float). 214 -- 215 -- Lx A valid Locking_Policy pragma applies to all the units in 216 -- this file, where x is the first character (upper case) of 217 -- the policy name (e.g. 'C' for Ceiling_Locking). 218 -- 219 -- NO No object. This flag indicates that the units in this file 220 -- were not compiled to produce an object. This can occur as a 221 -- result of the use of -gnatc, or if no object can be produced 222 -- (e.g. when a package spec is compiled instead of the body, 223 -- or a subunit on its own). 224 -- 225 -- NR No_Run_Time. Indicates that a pragma No_Run_Time applies 226 -- to all units in the file. 227 -- 228 -- NS Normalize_Scalars pragma in effect for all units in 229 -- this file. 230 -- 231 -- Qx A valid Queueing_Policy pragma applies to all the units 232 -- in this file, where x is the first character (upper case) 233 -- of the policy name (e.g. 'P' for Priority_Queueing). 234 -- 235 -- SL Indicates that the unit is an Interface to a Standalone 236 -- Library. Note that this indication is never given by the 237 -- compiler, but is added by the Project Manager in gnatmake 238 -- when an Interface ALI file is copied to the library 239 -- directory. 240 241 -- SS This unit references System.Secondary_Stack (that is, 242 -- the unit makes use of the secondary stack facilities). 243 -- 244 -- Tx A valid Task_Dispatching_Policy pragma applies to all 245 -- the units in this file, where x is the first character 246 -- (upper case) of the corresponding policy name (e.g. 'F' 247 -- for FIFO_Within_Priorities). 248 -- 249 -- UA Unreserve_All_Interrupts pragma was processed in one or 250 -- more units in this file 251 -- 252 -- ZX Units in this file use zero-cost exceptions and have 253 -- generated exception tables. If ZX is not present, the 254 -- longjmp/setjmp exception scheme is in use. 255 -- 256 -- Note that language defined units never output policy (Lx, Tx, Qx) 257 -- parameters. Language defined units must correctly handle all 258 -- possible cases. These values are checked for consistency by the 259 -- binder and then copied to the generated binder output file. 260 261 -- Note: The P line must be present. Even in Ignore_Errors mode, Scan_ALI 262 -- insists on finding a P line. So if changes are made to the ALI format, 263 -- they should not include removing the P line! 264 265 -- --------------------- 266 -- -- R Restrictions -- 267 -- --------------------- 268 269 -- There are two forms for R lines, positional and named. The positional 270 -- notation is now considered obsolescent, it is not generated by the most 271 -- recent versions of the compiler except under control of the debug switch 272 -- -gnatdR, but is still recognized by the binder. 273 274 -- The recognition by the binder is to ease the transition, and better deal 275 -- with some cases of inconsistent builds using incompatible versions of 276 -- the compiler and binder. The named notation is the current preferred 277 -- approach. 278 279 -- Note that R lines are generated using the information in unit Rident, 280 -- and intepreted by the binder using the information in System.Rident. 281 -- Normally these two units should be effectively identical. However in 282 -- some cases of inconsistent builds, they may be different. This may lead 283 -- to binder diagnostics, which can be suppressed using the -C switch for 284 -- the binder, which results in ignoring unrecognized restrictions in the 285 -- ali files. 286 287 -- --------------------------------------- 288 -- -- R Restrictions (Positional Form) -- 289 -- --------------------------------------- 290 291 -- The first R line records the status of restrictions generated by pragma 292 -- Restrictions encountered, as well as information on what the compiler 293 -- has been able to determine with respect to restrictions violations. 294 -- The format is: 295 296 -- R <<restriction-characters>> <<restriction-param-id-entries>> 297 298 -- The first parameter is a string of characters that records 299 -- information regarding restrictions that do not take parameter not 300 -- take parameter values. It is a string of characters, one character 301 -- for each value (in order) in All_Boolean_Restrictions. There are 302 -- three possible settings for each restriction: 303 304 -- r Restricted. Unit was compiled under control of a pragma 305 -- Restrictions for the corresponding restriction. In this case 306 -- the unit certainly does not violate the Restriction, since 307 -- this would have been detected by the compiler. 308 309 -- n Not used. The unit was not compiled under control of a pragma 310 -- Restrictions for the corresponding restriction, and does not 311 -- make any use of the referenced feature. 312 313 -- v Violated. The unit was not compiled under control of a pragma 314 -- Restrictions for the corresponding restriction, and it does 315 -- indeed use the referenced feature. 316 317 -- This information is used in the binder to check consistency, i.e. to 318 -- detect cases where one unit has "r" and another unit has "v", which 319 -- is not permitted, since these restrictions are partition-wide. 320 321 -- The second parameter, which immediately follows the first (with no 322 -- separating space) gives restriction information for identifiers for 323 -- which a parameter is given. 324 325 -- The parameter is a string of entries, one for each value in 326 -- Restrict.All_Parameter_Restrictions. Each entry has two components 327 -- in sequence, the first indicating whether or not there is a 328 -- restriction, and the second indicating whether or not the compiler 329 -- detected violations. In the boolean case it is not necessary to 330 -- separate these, since if a restriction is set, and violated, that is 331 -- an error. But in the parameter case, this is not true. For example, 332 -- we can have a unit with a pragma Restrictions (Max_Tasks => 4), 333 -- where the compiler can detect that there are exactly three tasks 334 -- declared. Both of these pieces of information must be passed to the 335 -- binder. The parameter of 4 is important in case the total number of 336 -- tasks in the partition is greater than 4. The parameter of 3 is 337 -- important in case some other unit has a restrictions pragma with 338 -- Max_Tasks=>2. 339 340 -- The component for the presence of restriction has one of two 341 -- possible forms: 342 343 -- n No pragma for this restriction is present in the set of units 344 -- for this ali file. 345 346 -- rN At least one pragma for this restriction is present in the 347 -- set of units for this ali file. The value N is the minimum 348 -- parameter value encountered in any such pragma. N is in the 349 -- range of Integer (a value larger than N'Last causes the 350 -- pragma to be ignored). 351 352 -- The component for the violation detection has one of three 353 -- possible forms: 354 355 -- n No violations were detected by the compiler 356 357 -- vN A violation was detected. N is either the maximum or total 358 -- count of violations (depending on the checking type) in all 359 -- the units represented by the ali file). Note that this 360 -- setting is only allowed for restrictions that are in 361 -- Checked_[Max|Sum]_Parameter_Restrictions. The value here is 362 -- known to be exact by the compiler and is in the range of 363 -- Natural. 364 365 -- vN+ A violation was detected. The compiler cannot determine 366 -- the exact count of violations, but it is at least N. 367 368 -- There are no spaces within the parameter string, so the entry 369 -- described above in the header of this section for Max_Tasks would 370 -- appear as the string r4v3. 371 372 -- Note: The restrictions line is required to be present. Even in 373 -- Ignore_Errors mode, Scan_ALI expects to find an R line and will 374 -- signal a fatal error if it is missing. This means that future 375 -- changes to the ALI file format must retain the R line. 376 377 -- ---------------------------------- 378 -- -- R Restrictions (Named Form) -- 379 -- ---------------------------------- 380 381 -- The first R line for named form announces that named notation will be 382 -- used, and also assures that there is at least one R line present, which 383 -- makes parsing of ali files simpler. A blank line preceds the RN line. 384 385 -- RN 386 387 -- In named notation, the restrictions are given as a series of lines, one 388 -- per retrictions that is specified or violated (no information is present 389 -- for restrictions that are not specified or violated). In the following 390 -- name is the name of the restriction in all upper case. 391 392 -- For boolean restrictions, we have only two possibilities. A restrictions 393 -- pragma is present, or a violation is detected: 394 395 -- RR name 396 397 -- A restriction pragma is present for the named boolean restriction. 398 -- No violations were detected by the compiler (or the unit in question 399 -- would have been found to be illegal). 400 401 -- RV name 402 403 -- No restriction pragma is present for the named boolean restriction. 404 -- However, the compiler did detect one or more violations of this 405 -- restriction, which may require a binder consistency check. 406 407 -- For the case of restrictions that take a parameter, we need both the 408 -- information from pragma if present, and the actual information about 409 -- what possible violations occur. For example, we can have a unit with 410 -- a pragma Restrictions (Max_Tasks => 4), where the compiler can detect 411 -- that there are exactly three tasks declared. Both of these pieces 412 -- of information must be passed to the binder. The parameter of 4 is 413 -- important in case the total number of tasks in the partition is greater 414 -- than 4. The parameter of 3 is important in case some other unit has a 415 -- restrictions pragma with Max_Tasks=>2. 416 417 -- RR name=N 418 419 -- A restriction pragma is present for the named restriction which is 420 -- one of the restrictions taking a parameter. The value N (a decimal 421 -- integer) is the value given in the restriction pragma. 422 423 -- RV name=N 424 425 -- A restriction pragma may or may not be present for the restriction 426 -- given by name (one of the restrictions taking a parameter). But in 427 -- either case, the compiler detected possible violations. N (a decimal 428 -- integer) is the maximum or total count of violations (depending 429 -- on the checking type) in all the units represented by the ali file). 430 -- The value here is known to be exact by the compiler and is in the 431 -- range of Natural. Note that if an RR line is present for the same 432 -- restriction, then the value in the RV line cannot exceed the value 433 -- in the RR line (since otherwise the compiler would have detected a 434 -- violation of the restriction). 435 436 -- RV name=N+ 437 438 -- Similar to the above, but the compiler cannot determine the exact 439 -- count of violations, but it is at least N. 440 441 -- ------------------------------------------------- 442 -- -- R Restrictions (No_Dependence Information) -- 443 -- ------------------------------------------------- 444 445 -- Subsequent R lines are present only if pragma Restriction No_Dependence 446 -- is used. There is one such line for each such pragma appearing in the 447 -- extended main unit. The format is: 448 449 -- R unit_name 450 451 -- Here the unit name is in all lower case. The components of the unit 452 -- name are separated by periods. The names themselves are in encoded 453 -- form, as documented in Namet. 454 455 -- ------------------------- 456 -- -- I Interrupt States -- 457 -- ------------------------- 458 459 -- I interrupt-number interrupt-state line-number 460 461 -- This line records information from an Interrupt_State pragma. There 462 -- is one line for each separate pragma, and if no such pragmas are 463 -- used, then no I lines are present. 464 465 -- The interrupt-number is an unsigned positive integer giving the 466 -- value of the interrupt as defined in Ada.Interrupts.Names. 467 468 -- The interrupt-state is one of r/s/u for Runtime/System/User 469 470 -- The line number is an unsigned decimal integer giving the line 471 -- number of the corresponding Interrupt_State pragma. This is used 472 -- in consistency messages. 473 474 -- -------------------------------------- 475 -- -- S Priority Specific Dispatching -- 476 -- -------------------------------------- 477 478 -- S policy_identifier first_priority last_priority line-number 479 480 -- This line records information from a Priority_Specific_Dispatching 481 -- pragma. There is one line for each separate pragma, and if no such 482 -- pragmas are used, then no S lines are present. 483 484 -- The policy_identifier is the first character (upper case) of the 485 -- corresponding policy name (e.g. 'F' for FIFO_Within_Priorities). 486 487 -- The first_priority and last_priority fields define the range of 488 -- priorities to which the specified dispatching policy apply. 489 490 -- The line number is an unsigned decimal integer giving the line 491 -- number of the corresponding Priority_Specific_Dispatching pragma. 492 -- This is used in consistency messages. 493 494 ---------------------------- 495 -- Compilation Unit Lines -- 496 ---------------------------- 497 498 -- Following these header lines, a set of information lines appears for 499 -- each compilation unit that appears in the corresponding object file. In 500 -- particular, when a package body or subprogram body is compiled, there 501 -- will be two sets of information, one for the spec and one for the body, 502 -- with the entry for the body appearing first. This is the only case in 503 -- which a single ALI file contains more than one unit (in particular note 504 -- that subunits do *not* count as compilation units for this purpose, and 505 -- generate no library information, since they are inlined). 506 507 -- -------------------- 508 -- -- U Unit Header -- 509 -- -------------------- 510 511 -- The lines for each compilation unit have the following form 512 513 -- U unit-name source-name version <<attributes>> 514 -- 515 -- This line identifies the unit to which this section of the library 516 -- information file applies. The first three parameters are the unit 517 -- name in internal format, as described in package Uname, and the name 518 -- of the source file containing the unit. 519 -- 520 -- Version is the version given as eight hexadecimal characters with 521 -- upper case letters. This value is the exclusive or of the source 522 -- checksums of the unit and all its semantically dependent units. 523 -- 524 -- The <<attributes>> are a series of two letter codes indicating 525 -- information about the unit: 526 -- 527 -- BD Unit does not have pragma Elaborate_Body, but the elaboration 528 -- circuit has determined that it would be a good idea if this 529 -- pragma were present, since the body of the package contains 530 -- elaboration code that modifies one or more variables in the 531 -- visible part of the package. The binder will try, but does 532 -- not promise, to keep the elaboration of the body close to 533 -- the elaboration of the spec. 534 -- 535 -- DE Dynamic Elaboration. This unit was compiled with the dynamic 536 -- elaboration model, as set by either the -gnatE switch or 537 -- pragma Elaboration_Checks (Dynamic). 538 -- 539 -- EB Unit has pragma Elaborate_Body, or is a generic instance that 540 -- has a body. Set for instances because RM 12.3(20) requires 541 -- that the body be immediately elaborated after the spec (we 542 -- would normally do that anyway, because elaborate spec and 543 -- body together whenever possible, and for an instance it is 544 -- always possible; however setting EB ensures that this is done 545 -- even when using the -p gnatbind switch). 546 -- 547 -- EE Elaboration entity is present which must be set true when 548 -- the unit is elaborated. The name of the elaboration entity is 549 -- formed from the unit name in the usual way. If EE is present, 550 -- then this boolean must be set True as part of the elaboration 551 -- processing routine generated by the binder. Note that EE can 552 -- be set even if NE is set. This happens when the boolean is 553 -- needed solely for checking for the case of access before 554 -- elaboration. 555 -- 556 -- GE Unit is a generic declaration, or corresponding body 557 -- 558 -- IL Unit source uses a style with identifiers in all lower-case 559 -- IU (IL) or all upper case (IU). If the standard mixed-case usage 560 -- is detected, or the compiler cannot determine the style, then 561 -- no I parameter will appear. 562 -- 563 -- IS Initialize_Scalars pragma applies to this unit, or else there 564 -- is at least one use of the Invalid_Value attribute. 565 -- 566 -- KM Unit source uses a style with keywords in mixed case (KM) 567 -- KU or all upper case (KU). If the standard lower-case usage is 568 -- is detected, or the compiler cannot determine the style, then 569 -- no K parameter will appear. 570 -- 571 -- NE Unit has no elaboration routine. All subprogram bodies and 572 -- specs are in this category. Package bodies and specs may or 573 -- may not have NE set, depending on whether or not elaboration 574 -- code is required. Set if N_Compilation_Unit node has flag 575 -- Has_No_Elaboration_Code set. 576 -- 577 -- OL The units in this file are compiled with a local pragma 578 -- Optimize_Alignment, so no consistency requirement applies 579 -- to these units. All internal units have this status since 580 -- they have an automatic default of Optimize_Alignment (Off). 581 -- 582 -- OO Optimize_Alignment (Off) 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 -- OS Optimize_Alignment (Space) 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 -- OT Optimize_Alignment (Time) is the default setting for all 591 -- units in this file. All files in the partition that specify 592 -- a default must specify the same default. 593 -- 594 -- PF The unit has a library-level (package) finalizer 595 -- 596 -- PK Unit is package, rather than a subprogram 597 -- 598 -- PU Unit has pragma Pure 599 -- 600 -- PR Unit has pragma Preelaborate 601 -- 602 -- RA Unit declares a Remote Access to Class-Wide (RACW) type 603 -- 604 -- RC Unit has pragma Remote_Call_Interface 605 -- 606 -- RT Unit has pragma Remote_Types 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. 658 659 -- ----------------------- 660 -- -- L Linker_Options -- 661 -- ----------------------- 662 663 -- Following the W lines (if any, or the U line if not), are an optional 664 -- series of lines that indicates the usage of the pragma Linker_Options in 665 -- the associated unit. For each appearance of a pragma Linker_Options (or 666 -- Link_With) in the unit, a line is present with the form: 667 668 -- L "string" 669 670 -- where string is the string from the unit line enclosed in quotes. 671 -- Within the quotes the following can occur: 672 673 -- c graphic characters in range 20-7E other than " or { 674 -- "" indicating a single " character 675 -- {hh} indicating a character whose code is hex hh (0-9,A-F) 676 -- {00} [ASCII.NUL] is used as a separator character 677 -- to separate multiple arguments of a single 678 -- Linker_Options pragma. 679 680 -- For further details, see Stringt.Write_String_Table_Entry. Note that 681 -- wide characters in the form {hhhh} cannot be produced, since pragma 682 -- Linker_Option accepts only String, not Wide_String. 683 684 -- The L lines are required to appear in the same order as the 685 -- corresponding Linker_Options (or Link_With) pragmas appear in the 686 -- source file, so that this order is preserved by the binder in 687 -- constructing the set of linker arguments. 688 689 -- -------------- 690 -- -- N Notes -- 691 -- -------------- 692 693 -- The final section of unit-specific lines contains notes which record 694 -- annotations inserted in source code for processing by external tools 695 -- using pragmas. For each occurrence of any of these pragmas, a line is 696 -- generated with the following syntax: 697 698 -- N x<sloc> [<arg_id>:]<arg> ... 699 700 -- x is one of: 701 -- A pragma Annotate 702 -- C pragma Comment 703 -- I pragma Ident 704 -- T pragma Title 705 -- S pragma Subtitle 706 707 -- <sloc> is the source location of the pragma in line:col format 708 709 -- Successive entries record the pragma_argument_associations. 710 711 -- If a pragma argument identifier is present, the entry is prefixed 712 -- with the pragma argument identifier <arg_id> followed by a colon. 713 714 -- <arg> represents the pragma argument, and has the following 715 -- conventions: 716 717 -- - identifiers are output verbatim 718 -- - static string expressions are output as literals encoded as 719 -- for L lines 720 -- - static integer expressions are output as decimal literals 721 -- - any other expression is replaced by the placeholder "<expr>" 722 723 --------------------- 724 -- Reference Lines -- 725 --------------------- 726 727 -- The reference lines contain information about references from any of the 728 -- units in the compilation (including body version and version attributes, 729 -- linker options pragmas and source dependencies). 730 731 -- ------------------------------------ 732 -- -- E External Version References -- 733 -- ------------------------------------ 734 735 -- One of these lines is present for each use of 'Body_Version or 'Version 736 -- in any of the units of the compilation. These are used by the linker to 737 -- determine which version symbols must be output. The format is simply: 738 739 -- E name 740 741 -- where name is the external name, i.e. the unit name with either a S or a 742 -- B for spec or body version referenced (Body_Version always references 743 -- the body, Version references the Spec, except in the case of a reference 744 -- to a subprogram with no separate spec). Upper half and wide character 745 -- codes are encoded using the same method as in Namet (Uhh for upper half, 746 -- Whhhh for wide character, where hh are hex digits). 747 748 -- --------------------- 749 -- -- D Dependencies -- 750 -- --------------------- 751 752 -- The dependency lines indicate the source files on which the compiled 753 -- units depend. This is used by the binder for consistency checking. 754 -- These lines are also referenced by the cross-reference information. 755 756 -- D source-name time-stamp checksum [subunit-name] line:file-name 757 758 -- The time-stamp field contains the time stamp of the corresponding 759 -- source file. See types.ads for details on time stamp representation. 760 761 -- The checksum is an 8-hex digit representation of the source file 762 -- checksum, with letters given in lower case. 763 764 -- The subunit name is present only if the dependency line is for a 765 -- subunit. It contains the fully qualified name of the subunit in all 766 -- lower case letters. 767 768 -- The line:file-name entry is present only if a Source_Reference 769 -- pragma appeared in the source file identified by source-name. In 770 -- this case, it gives the information from this pragma. Note that this 771 -- allows cross-reference information to be related back to the 772 -- original file. Note: the reason the line number comes first is that 773 -- a leading digit immediately identifies this as a Source_Reference 774 -- entry, rather than a subunit-name. 775 776 -- A line number of zero for line: in this entry indicates that there 777 -- is more than one source reference pragma. In this case, the line 778 -- numbers in the cross-reference are correct, and refer to the 779 -- original line number, but there is no information that allows a 780 -- reader of the ALI file to determine the exact mapping of physical 781 -- line numbers back to the original source. 782 783 -- Files with a zero checksum and a non-zero time stamp are in general 784 -- files on which the compilation depends but which are not Ada files 785 -- with further dependencies. This includes preprocessor data files 786 -- and preprocessor definition files. 787 788 -- Note: blank lines are ignored when the library information is read, 789 -- and separate sections of the file are separated by blank lines to 790 -- ease readability. Blanks between fields are also ignored. 791 792 -- For entries corresponding to files that were not present (and thus 793 -- resulted in error messages), or for files that are not part of the 794 -- dependency set, both the time stamp and checksum are set to all zero 795 -- characters. These dummy entries are ignored by the binder in 796 -- dependency checking, but must be present for proper interpretation 797 -- of the cross-reference data. 798 799 -------------------------- 800 -- Cross-Reference Data -- 801 -------------------------- 802 803 -- The cross-reference data follows the dependency lines. See the spec of 804 -- Lib.Xref in file lib-xref.ads for details on the format of this data. 805 806 --------------------------------- 807 -- Source Coverage Obligations -- 808 --------------------------------- 809 810 -- The Source Coverage Obligation (SCO) information follows the cross- 811 -- reference data. See the spec of Par_SCO in file par_sco.ads for full 812 -- details of the format. 813 814 ---------------------- 815 -- Alfa Information -- 816 ---------------------- 817 818 -- The Alfa information follows the SCO information. See the spec of Alfa 819 -- in file alfa.ads for full details of the format. 820 821 ------------------------------------- 822 -- T Target Dependent Information -- 823 ------------------------------------- 824 825 -- This section is present if the option to generate target dependent 826 -- information is present (this flag is set by the -gnatT switch). The 827 -- format of T lines is: 828 829 -- T key val 830 831 -- There is one line for each constant declared in the Ttypes package 832 833 -- key is the four letter code (which can be found as a comment on each 834 -- of the constant declarations in Ttypes). 835 836 -- val is the value of the constant, which is either a non-negative 837 -- decimal constant, or TRUE or FALSE for a Boolean value. 838 839 ---------------------- 840 -- Global Variables -- 841 ---------------------- 842 843 -- The table defined here stores one entry for each Interrupt_State pragma 844 -- encountered either in the main source or in an ancillary with'ed source. 845 -- Since interrupt state values have to be consistent across all units in a 846 -- partition, we detect inconsistencies at compile time when we can. 847 848 type Interrupt_State_Entry is record 849 Interrupt_Number : Pos; 850 -- Interrupt number value 851 852 Interrupt_State : Character; 853 -- Set to r/s/u for Runtime/System/User 854 855 Pragma_Loc : Source_Ptr; 856 -- Location of pragma setting this value in place 857 end record; 858 859 package Interrupt_States is new Table.Table ( 860 Table_Component_Type => Interrupt_State_Entry, 861 Table_Index_Type => Nat, 862 Table_Low_Bound => 1, 863 Table_Initial => 30, 864 Table_Increment => 200, 865 Table_Name => "Name_Interrupt_States"); 866 867 -- The table structure defined here stores one entry for each 868 -- Priority_Specific_Dispatching pragma encountered either in the main 869 -- source or in an ancillary with'ed source. Since have to be consistent 870 -- across all units in a partition, we may as well detect inconsistencies 871 -- at compile time when we can. 872 873 type Specific_Dispatching_Entry is record 874 Dispatching_Policy : Character; 875 -- First character (upper case) of the corresponding policy name 876 877 First_Priority : Nat; 878 -- Lower bound of the priority range to which the specified dispatching 879 -- policy applies. 880 881 Last_Priority : Nat; 882 -- Upper bound of the priority range to which the specified dispatching 883 -- policy applies. 884 885 Pragma_Loc : Source_Ptr; 886 -- Location of pragma setting this value in place 887 end record; 888 889 package Specific_Dispatching is new Table.Table ( 890 Table_Component_Type => Specific_Dispatching_Entry, 891 Table_Index_Type => Nat, 892 Table_Low_Bound => 1, 893 Table_Initial => 10, 894 Table_Increment => 100, 895 Table_Name => "Name_Priority_Specific_Dispatching"); 896 897 ----------------- 898 -- Subprograms -- 899 ----------------- 900 901 procedure Ensure_System_Dependency; 902 -- This procedure ensures that a dependency is created on system.ads. Even 903 -- if there is no semantic dependency, Targparm has read the file to 904 -- acquire target parameters, so we need a source dependency. 905 906 procedure Write_ALI (Object : Boolean); 907 -- This procedure writes the library information for the current main unit 908 -- The Object parameter is true if an object file is created, and false 909 -- otherwise. 910 -- 911 -- Note: in the case where we are not generating code (-gnatc mode), this 912 -- routine only writes an ALI file if it cannot find an existing up to 913 -- date ALI file. If it *can* find an existing up to date ALI file, then 914 -- it reads this file and sets the Lib.Compilation_Arguments table from 915 -- the A lines in this file. 916 917 procedure Add_Preprocessing_Dependency (S : Source_File_Index); 918 -- Indicate that there is a dependency to be added on a preprocessing data 919 -- file or on a preprocessing definition file. 920 921end Lib.Writ; 922