1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2004 Free Software Foundation, Inc. --
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 2, 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 COPYING. If not, write --
19 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
20 -- MA 02111-1307, USA. --
22 -- GNAT was originally developed by the GNAT team at New York University. --
23 -- Extensive contributions were provided by Ada Core Technologies Inc. --
25 ------------------------------------------------------------------------------
27 -- This package contains the routines for writing the library information
31 -----------------------------------
32 -- Format of Library Information --
33 -----------------------------------
35 -- Note: the contents of the ali file are summarized in the GNAT
36 -- user's guide, so if any non-trivial changes are made to this
37 -- section, they should be reflected in the user's guide.
39 -- This section describes the format of the library information that is
40 -- associated with object files. The exact method of this association is
41 -- potentially implementation dependent and is described and implemented
42 -- in package ali. From the point of view of the description here, all we
43 -- need to know is that the information is represented as a string of
44 -- characters that is somehow associated with an object file, and can be
45 -- retrieved. If no library information exists for a given object file,
46 -- then we take this as equivalent to the non-existence of the object
47 -- file, as if source file has not been previously compiled.
49 -- The library information is written as a series of lines of the form:
51 -- Key_Character parameter parameter ...
57 -- The initial header lines in the file give information about the
58 -- compilation environment, and identify other special information
59 -- such as main program parameters.
65 -- V "xxxxxxxxxxxxxxxx"
67 -- This line indicates the library output version, as defined in
68 -- Gnatvsn. It ensures that separate object modules of a program are
69 -- consistent. It has to be changed if anything changes which would
70 -- affect successful binding of separately compiled modules.
71 -- Examples of such changes are modifications in the format of the
72 -- library info described in this package, or modifications to
73 -- calling sequences, or to the way that data is represented.
75 -- ---------------------
76 -- -- M Main Program --
77 -- ---------------------
79 -- M type [priority] [T=time-slice] W=?
81 -- This line appears only if the main unit for this file is
82 -- suitable for use as a main program. The parameters are:
86 -- P for a parameterless procedure
87 -- F for a function returning a value of integral type
88 -- (used for writing a main program returning an exit status)
92 -- Present only if there was a valid pragma Priority in the
93 -- corresponding unit to set the main task priority. It is
94 -- an unsigned decimal integer.
98 -- Present only if there was a valid pragma Time_Slice in the
99 -- corresponding unit. It is an unsigned decimal integer in
100 -- the range 0 .. 10**9 giving the time slice value in units
101 -- of milliseconds. The actual significance of this parameter
102 -- is target dependent.
106 -- This parameter indicates the wide character encoding
107 -- method used when compiling the main program file. The ?
108 -- character is the single character used in the -gnatW?
109 -- switch. This is used to provide the default wide-character
110 -- encoding for Wide_Text_IO files.
118 -- One of these lines appears for each of the arguments present
119 -- in the call to the gnat1 program. This can be used if it is
120 -- necessary to reconstruct this call (e.g. for fix and continue)
122 -- -------------------
123 -- -- P Parameters --
124 -- -------------------
128 -- Indicates various information that applies to the compilation
129 -- of the corresponding source unit. Parameters is a sequence of
130 -- zero or more two letter codes that indicate configuration
131 -- pragmas and other parameters that apply:
133 -- The arguments are as follows:
135 -- CE Compilation errors. If this is present it means that the
136 -- ali file resulted from a compilation with the -gnatQ
137 -- switch set, and illegalities were detected. The ali
138 -- file contents may not be completely reliable, but the
139 -- format will be correct and complete. Note that NO is
140 -- always present if CE is present.
142 -- FD Configuration pragmas apply to all the units in this
143 -- file specifying a possibly non-standard floating point
144 -- format (VAX float with Long_Float using D_Float)
146 -- FG Configuration pragmas apply to all the units in this
147 -- file specifying a possibly non-standard floating point
148 -- format (VAX float with Long_Float using G_Float)
150 -- FI Configuration pragmas apply to all the units in this
151 -- file specifying a possibly non-standard floating point
152 -- format (IEEE Float)
154 -- Lx A valid Locking_Policy pragma applies to all the units
155 -- in this file, where x is the first character (upper case)
156 -- of the policy name (e.g. 'C' for Ceiling_Locking)
158 -- NO No object. This flag indicates that the units in this
159 -- file were not compiled to produce an object. This can
160 -- occur as a result of the use of -gnatc, or if no object
161 -- can be produced (e.g. when a package spec is compiled
162 -- instead of the body, or a subunit on its own).
164 -- NR No_Run_Time. Indicates that a pragma No_Run_Time applies
165 -- to all units in the file.
167 -- NS Normalize_Scalars pragma in effect for all units in
170 -- Qx A valid Queueing_Policy pragma applies to all the units
171 -- in this file, where x is the first character (upper case)
172 -- of the policy name (e.g. 'P' for Priority_Queueing).
174 -- SL Indicates that the unit is an Interface to a Standalone
175 -- Library. Note that this indication is never given by the
176 -- compiler, but is added by the Project Manager in gnatmake
177 -- when an Interface ALI file is copied to the library
180 -- SS This unit references System.Secondary_Stack (that is,
181 -- the unit makes use of the secondary stack facilities).
183 -- Tx A valid Task_Dispatching_Policy pragma applies to all
184 -- the units in this file, where x is the first character
185 -- (upper case) of the corresponding policy name (e.g. 'F'
186 -- for FIFO_Within_Priorities).
188 -- UA Unreserve_All_Interrupts pragma was processed in one or
189 -- more units in this file
191 -- UX Generated code contains unit exception table pointer
192 -- (i.e. it uses zero-cost exceptions, and there is at
193 -- least one subprogram present).
195 -- ZX Units in this file use zero-cost exceptions and have
196 -- generated exception tables. If ZX is not present, the
197 -- longjmp/setjmp exception scheme is in use.
199 -- Note that language defined units never output policy (Lx,Tx,Qx)
200 -- parameters. Language defined units must correctly handle all
201 -- possible cases. These values are checked for consistency by the
202 -- binder and then copied to the generated binder output file.
204 -- ---------------------
205 -- -- R Restrictions --
206 -- ---------------------
208 -- Two lines are generated to record the status of restrictions that can
209 -- be specified by pragma Restrictions. The first of these lines refers
210 -- to Restriction_Id values:
212 -- R <<restriction-characters>>
214 -- This line records information regarding restrictions that do
215 -- not take parameter values. Here "restriction-characters is a
216 -- string of characters, one for each value (in order) defined
217 -- in Restrict.All_Boolean_Restrictions. There are three possible
218 -- settings for each restriction:
220 -- r Restricted. Unit was compiled under control of a pragma
221 -- Restrictions for the corresponding restriction. In
222 -- this case the unit certainly does not violate the
223 -- Restriction, since this would have been detected by
226 -- n Not used. The unit was not compiled under control of a
227 -- pragma Restrictions for the corresponding restriction,
228 -- and does not make any use of the referenced feature.
230 -- v Violated. The unit was not compiled under control of a
231 -- pragma Restrictions for the corresponding restriction,
232 -- and it does indeed use the referenced feature.
234 -- This information is used in the binder to check consistency,
235 -- i.e. to detect cases where one unit has "r" and another unit
236 -- has "v", which is not permitted, since these restrictions
237 -- are partition-wide.
239 -- The second R line refers to parameter restrictions:
241 -- R <<restriction-parameter-id-entries>>
243 -- The parameter is a string of entries, one for each value in
244 -- Restrict.All_Parameter_Restrictions. Each entry has two
245 -- components in sequence, the first indicating whether or not
246 -- there is a restriction, and the second indicating whether
247 -- or not the compiler detected violations. In the boolean case
248 -- it is not necessary to separate these, since if a restriction
249 -- is set, and violated, that is an error. But in the parameter
250 -- case, this is not true. For example, we can have a unit with
251 -- a pragma Restrictions (Max_Tasks => 4), where the compiler
252 -- can detect that there are exactly three tasks declared. Both
253 -- of these pieces of information must be passed to the binder.
254 -- The parameter of 4 is important in case the total number of
255 -- tasks in the partition is greater than 4. The parameter of
256 -- 3 is important in case some other unit has a restrictions
257 -- pragma with Max_Tasks=>2.
259 -- The component for the presence of restriction has one of two
262 -- n No pragma for this restriction is present in the
263 -- set of units for this ali file.
265 -- rN At least one pragma for this restriction is present
266 -- in the set of units for this ali file. The value N
267 -- is the minimum parameter value encountered in any
268 -- such pragma. N is in the range of Integer (a value
269 -- larger than N'Last causes the pragma to be ignored).
271 -- The component for the violation detection has one of three
274 -- n No violations were detected by the compiler
276 -- vN A violation was detected. N is either the maximum or total
277 -- count of violations (depending on the checking type) in
278 -- all the units represented by the ali file). Note that
279 -- this setting is only allowed for restrictions that are
280 -- in Checked_[Max|Sum]_Parameter_Restrictions. The value
281 -- here is known to be exact by the compiler and is in the
284 -- vN+ A violation was detected. The compiler cannot determine
285 -- the exact count of violations, but it is at least N.
287 -- There are no spaces in the line, so the entry for the example
288 -- in the header of this section for Max_Tasks would appear as
291 -- ------------------------
292 -- -- I Interrupt States --
293 -- ------------------------
295 -- I interrupt-number interrupt-state line-number
297 -- This line records information from an Interrupt_State pragma.
298 -- There is one line for each separate pragma, and if no such
299 -- pragmas are used, then no I lines are present.
301 -- The interrupt-number is an unsigned positive integer giving
302 -- the value of the interrupt as defined in Ada.Interrupts.Names.
304 -- The interrupt-state is one of r/s/u for Runtime/System/User
306 -- The line number is an unsigned decimal integer giving the
307 -- line number of the corresponding Interrupt_State pragma.
308 -- This is used in consistency messages.
310 ----------------------------
311 -- Compilation Unit Lines --
312 ----------------------------
314 -- Following these header lines, a set of information lines appears for
315 -- each compilation unit that appears in the corresponding object file.
316 -- In particular, when a package body or subprogram body is compiled,
317 -- there will be two sets of information, one for the spec and one for
318 -- the body. with the entry for the body appearing first. This is the
319 -- only case in which a single ALI file contains more than one unit (in
320 -- particular note that subunits do *not* count as compilation units for
321 -- this purpose, and generate no library information, since they are
324 -- --------------------
325 -- -- U Unit Header --
326 -- --------------------
328 -- The lines for each compilation unit have the following form.
330 -- U unit-name source-name version <<attributes>>
332 -- This line identifies the unit to which this section of the
333 -- library information file applies. The first three parameters are
334 -- the unit name in internal format, as described in package Uname,
335 -- and the name of the source file containing the unit.
337 -- Version is the version given as eight hexadecimal characters
338 -- with upper case letters. This value is the exclusive or of the
339 -- source checksums of the unit and all its semantically dependent
342 -- The <<attributes>> are a series of two letter codes indicating
343 -- information about the unit:
345 -- DE Dynamic Elaboration. This unit was compiled with the
346 -- dynamic elaboration model, as set by either the -gnatE
347 -- switch or pragma Elaboration_Checks (Dynamic).
349 -- EB Unit has pragma Elaborate_Body
351 -- EE Elaboration entity is present which must be set true when
352 -- the unit is elaborated. The name of the elaboration entity
353 -- is formed from the unit name in the usual way. If EE is
354 -- present, then this boolean must be set True as part of the
355 -- elaboration processing routine generated by the binder.
356 -- Note that EE can be set even if NE is set. This happens
357 -- when the boolean is needed solely for checking for the
358 -- case of access before elaboration.
360 -- GE Unit is a generic declaration, or corresponding body
362 -- IL Unit source uses a style with identifiers in all lower
363 -- IU case (IL) or all upper case (IU). If the standard mixed-
364 -- case usage is detected, or the compiler cannot determine
365 -- the style, then no I parameter will appear.
367 -- IS Initialize_Scalars pragma applies to this unit
369 -- KM Unit source uses a style with keywords in mixed case
370 -- KU (KM) or all upper case (KU). If the standard lower-case
371 -- usage is detected, or the compiler cannot determine the
372 -- style, then no K parameter will appear.
374 -- NE Unit has no elaboration routine. All subprogram bodies
375 -- and specs are in this category. Package bodies and specs
376 -- may or may not have NE set, depending on whether or not
377 -- elaboration code is required. Set if N_Compilation_Unit
378 -- node has flag Has_No_Elaboration_Code set.
380 -- PK Unit is package, rather than a subprogram
382 -- PU Unit has pragma Pure
384 -- PR Unit has pragma Preelaborate
386 -- RA Unit declares a Remote Access to Class-Wide (RACW) type
388 -- RC Unit has pragma Remote_Call_Interface
390 -- RT Unit has pragma Remote_Types
392 -- SP Unit has pragma Shared_Passive.
394 -- SU Unit is a subprogram, rather than a package
396 -- The attributes may appear in any order, separated by spaces.
398 -- ---------------------
399 -- -- W Withed Units --
400 -- ---------------------
402 -- Following each U line, is a series of lines of the form
404 -- W unit-name [source-name lib-name] [E] [EA] [ED]
406 -- One of these lines is present for each unit that is mentioned in
407 -- an explicit with clause by the current unit. The first parameter
408 -- is the unit name in internal format. The second parameter is the
409 -- file name of the file that must be compiled to compile this unit.
410 -- It is usually the file for the body, except for packages
411 -- which have no body; for units that need a body, if the source file
412 -- for the body cannot be found, the file name of the spec is used
413 -- instead. The third parameter is the file name of the library
414 -- information file that contains the results of compiling this unit.
415 -- The optional modifiers are used as follows:
417 -- E pragma Elaborate applies to this unit
419 -- EA pragma Elaborate_All applies to this unit
421 -- ED Elaborate_All_Desirable set for this unit, which means
422 -- that there is no Elaborate_All, but the analysis suggests
423 -- that Program_Error may be raised if the Elaborate_All
424 -- conditions cannot be satisfied. The binder will attempt
425 -- to treat ED as EA if it can.
427 -- The parameter source-name and lib-name are omitted for the case
428 -- of a generic unit compiled with earlier versions of GNAT which
429 -- did not generate object or ali files for generics.
431 -- -----------------------
432 -- -- L Linker_Options --
433 -- -----------------------
435 -- Following the W lines (if any, or the U line if not), are an
436 -- optional series of lines that indicates the usage of the pragma
437 -- Linker_Options in the associated unit. For each appearence of a
438 -- pragma Linker_Options (or Link_With) in the unit, a line is
439 -- present with the form:
443 -- where string is the string from the unit line enclosed in quotes.
444 -- Within the quotes the following can occur:
446 -- c graphic characters in range 20-7E other than " or {
447 -- "" indicating a single " character
448 -- {hh} indicating a character whose code is hex hh (0-9,A-F)
449 -- {00} [ASCII.NUL] is used as a separator character
450 -- to separate multiple arguments of a single
451 -- Linker_Options pragma.
453 -- For further details, see Stringt.Write_String_Table_Entry. Note
454 -- that wide characters in the form {hhhh} cannot be produced, since
455 -- pragma Linker_Option accepts only String, not Wide_String.
457 -- The L lines are required to appear in the same order as the
458 -- corresponding Linker_Options (or Link_With) pragmas appear in
459 -- the source file, so that this order is preserved by the binder
460 -- in constructing the set of linker arguments.
462 ---------------------
463 -- Reference Lines --
464 ---------------------
466 -- The reference lines contain information about references from
467 -- any of the units in the compilation (including, body version
468 -- and version attributes, linker options pragmas and source
471 -- ------------------------------------
472 -- -- E External Version References --
473 -- ------------------------------------
475 -- One of these lines is present for each use of 'Body_Version or
476 -- 'Version in any of the units of the compilation. These are used
477 -- by the linker to determine which version symbols must be output.
478 -- The format is simply:
482 -- where name is the external name, i.e. the unit name with either
483 -- a S or a B for spec or body version referenced (Body_Version
484 -- always references the body, Version references the Spec, except
485 -- in the case of a reference to a subprogram with no separate spec).
486 -- Upper half and wide character codes are encoded using the same
487 -- method as in Namet (Uhh for upper half, Whhhh for wide character,
488 -- where hh are hex digits).
490 -- ---------------------
491 -- -- D Dependencies --
492 -- ---------------------
494 -- The dependency lines indicate the source files on which the compiled
495 -- units depend. This is used by the binder for consistency checking.
496 -- These lines are also referenced by the cross-reference information.
498 -- D source-name time-stamp checksum [subunit-name] line:file-name
500 -- The time-stamp field contains the time stamp of the
501 -- corresponding source file. See types.ads for details on
502 -- time stamp representation.
504 -- The checksum is an 8-hex digit representation of the source
505 -- file checksum, with letters given in lower case.
507 -- The subunit name is present only if the dependency line is for
508 -- a subunit. It contains the fully qualified name of the subunit
509 -- in all lower case letters.
511 -- The line:file-name entry is present only if a Source_Reference
512 -- pragma appeared in the source file identified by source-name.
513 -- In this case, it gives the information from this pragma. Note
514 -- that this allows cross-reference information to be related back
515 -- to the original file. Note: the reason the line number comes
516 -- first is that a leading digit immediately identifies this as
517 -- a Source_Reference entry, rather than a subunit-name.
519 -- A line number of zero for line: in this entry indicates that
520 -- there is more than one source reference pragma. In this case,
521 -- the line numbers in the cross-reference are correct, and refer
522 -- to the original line number, but there is no information that
523 -- allows a reader of the ALI file to determine the exact mapping
524 -- of physical line numbers back to the original source.
526 -- Files with a zero checksum and a non-zero time stamp are in general
527 -- files on which the compilation depends but which are not Ada files
528 -- with further dependencies. This includes preprocessor data files
529 -- and preprocessor definition files.
531 -- Note: blank lines are ignored when the library information is
532 -- read, and separate sections of the file are separated by blank
533 -- lines to ease readability. Blanks between fields are also
536 -- For entries corresponding to files that were not present (and
537 -- thus resulted in error messages), or for files that are not
538 -- part of the dependency set, both the time stamp and checksum
539 -- are set to all zero characters. These dummy entries are ignored
540 -- by the binder in dependency checking, but must be present for
541 -- proper interpretation of the cross-reference data.
543 --------------------------
544 -- Cross-Reference Data --
545 --------------------------
547 -- The cross-reference data follows the dependency lines. See
548 -- the spec of Lib.Xref for details on the format of this data.
550 ----------------------
551 -- Global_Variables --
552 ----------------------
554 -- The table structure defined here stores one entry for each
555 -- Interrupt_State pragma encountered either in the main source or
556 -- in an ancillary with'ed source. Since interrupt state values
557 -- have to be consistent across all units in a partition, we may
558 -- as well detect inconsistencies at compile time when we can.
560 type Interrupt_State_Entry is record
561 Interrupt_Number : Pos;
562 -- Interrupt number value
564 Interrupt_State : Character;
565 -- Set to r/s/u for Runtime/System/User
567 Pragma_Loc : Source_Ptr;
568 -- Location of pragma setting this value in place
571 package Interrupt_States is new Table.Table (
572 Table_Component_Type => Interrupt_State_Entry,
573 Table_Index_Type => Nat,
574 Table_Low_Bound => 1,
576 Table_Increment => 200,
577 Table_Name => "Name_Interrupt_States");
583 procedure Ensure_System_Dependency;
584 -- This procedure ensures that a dependency is created on system.ads.
585 -- Even if there is no semantic dependency, Targparm has read the
586 -- file to acquire target parameters, so we need a source dependency.
588 procedure Write_ALI (Object : Boolean);
589 -- This procedure writes the library information for the current main unit
590 -- The Object parameter is true if an object file is created, and false
593 -- Note: in the case where we are not generating code (-gnatc mode), this
594 -- routine only writes an ALI file if it cannot find an existing up to
595 -- date ALI file. If it *can* find an existing up to date ALI file, then
596 -- it reads this file and sets the Lib.Compilation_Arguments table from
597 -- the A lines in this file.
599 procedure Add_Preprocessing_Dependency (S : Source_File_Index);
600 -- Indicate that there is a dependency to be added on a preprocessing
601 -- data file or on a preprocessing definition file.