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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- L I B . W R I T --
-- --
-- S p e c --
-- --
-- Copyright (C) 1992-2015, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 3, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
-- Public License distributed with GNAT; see file COPYING3. If not, go to --
-- http://www.gnu.org/licenses for a complete copy of the license. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
-- This package contains the routines for writing the library information
package Lib.Writ is
-----------------------------------
-- Format of Library Information --
-----------------------------------
-- This section describes the format of the library information that is
-- associated with object files. The exact method of this association is
-- potentially implementation dependent and is described and implemented in
-- package ali. From the point of view of the description here, all we need
-- to know is that the information is represented as a string of characters
-- that is somehow associated with an object file, and can be retrieved. If
-- no library information exists for a given object file, then we take this
-- as equivalent to the non-existence of the object file, as if source file
-- has not been previously compiled.
-- The library information is written as a series of lines of the form:
-- Key_Character parameter parameter ...
-- The following sections describe the format of these lines in detail
--------------------------------------
-- Making Changes to the ALI Format --
--------------------------------------
-- A number of tools use ali.adb to parse ali files. This means that
-- changes to this format can cause old versions of these tools to be
-- incompatible with new versions of the compiler. Any changes to ali file
-- formats must be carefully evaluated to understand any such possible
-- conflicts, and in particular, it is very undesirable to create conflicts
-- between older versions of GPS and newer versions of the compiler.
-- If the following guidelines are respected, downward compatibility
-- problems (old tools reading new ali files) should be minimized:
-- The basic key character format must be kept
-- The V line must be the first line, this is checked by ali.adb even in
-- Ignore_Errors mode, and is used to verify that the file at hand is
-- indeed likely intended to be an ali file.
-- The P line must be present, though may be modified in contents
-- according to remaining guidelines. Again, ali.adb assumes the P
-- line is present even in Ignore_Errors mode.
-- New modifiers can generally be added (in particular adding new two
-- letter modifiers to the P or U lines is always safe)
-- Adding entirely new lines (with a new key letter) to the ali file is
-- always safe, at any point (other than before the V line), since such
-- lines will be ignored.
-- Following the guidelines in this section should ensure that this problem
-- is minimized and that old tools will be able to deal successfully with
-- new ali formats. Note that this does not apply to the compiler itself,
-- which always requires consistency between the ali files and the binder.
-- That is because one of the main functions of the binder is to ensure
-- consistency of the partition, and this can be compromised if the ali
-- files are inconsistent.
------------------
-- Header Lines --
------------------
-- The initial header lines in the file give information about the
-- compilation environment, and identify other special information such as
-- main program parameters.
-- ----------------
-- -- V Version --
-- ----------------
-- V "xxxxxxxxxxxxxxxx"
--
-- This line indicates the library output version, as defined in
-- Gnatvsn. It ensures that separate object modules of a program are
-- consistent. It has to be changed if anything changes which would
-- affect successful binding of separately compiled modules. Examples
-- of such changes are modifications in the format of the library info
-- described in this package, or modifications to calling sequences, or
-- to the way that data is represented.
-- Note: the V line absolutely must be the first line, and no change
-- to the ALI format should change this, since even in Ignore_Errors
-- mode, Scan_ALI insists on finding a V line.
-- ---------------------
-- -- M Main Program --
-- ---------------------
-- M type [priority] [T=time-slice] [C=cpu] W=?
-- This line appears only if the main unit for this file is suitable
-- for use as a main program. The parameters are:
-- type
-- P for a parameterless procedure
-- F for a function returning a value of integral type
-- (used for writing a main program returning an exit status)
-- priority
-- Present only if there was a valid pragma Priority in the
-- corresponding unit to set the main task priority. It is an
-- unsigned decimal integer.
-- T=time-slice
-- Present only if there was a valid pragma Time_Slice in the
-- corresponding unit. It is an unsigned decimal integer in the
-- range 0 .. 10**9 giving the time slice value in units of
-- milliseconds. The actual significance of this parameter is
-- target dependent.
-- C=cpu
-- Present only if there was a valid pragma CPU in the
-- corresponding unit to set the main task affinity. It is an
-- unsigned decimal integer.
-- W=?
-- This parameter indicates the wide character encoding method used
-- when compiling the main program file. The ? character is the
-- single character used in the -gnatW? switch. This is used to
-- provide the default wide-character encoding for Wide_Text_IO
-- files.
-- -----------------
-- -- A Argument --
-- -----------------
-- A argument
-- One of these lines appears for each of the arguments present in the
-- call to the gnat1 program. This can be used if it is necessary to
-- reconstruct this call (e.g. for fix and continue).
-- -------------------
-- -- P Parameters --
-- -------------------
-- P <<parameters>>
-- Indicates various information that applies to the compilation of the
-- corresponding source file. Parameters is a sequence of zero or more
-- two letter codes that indicate configuration pragmas and other
-- parameters that apply:
-- The arguments are as follows:
-- CE Compilation errors. If this is present it means that the ali
-- file resulted from a compilation with the -gnatQ switch set,
-- and illegalities were detected. The ali file contents may
-- not be completely reliable, but the format will be correct
-- and complete. Note that NO is always present if CE is
-- present.
-- DB Detect_Blocking pragma is in effect for all units in this
-- file.
-- Ex A valid Partition_Elaboration_Policy pragma applies to all
-- the units in this file, where x is the first character
-- (upper case) of the policy name (e.g. 'C' for Concurrent).
-- GP Set if this compilation was done in GNATprove mode, either
-- from direct use of GNATprove, or from use of -gnatdF.
-- Lx A valid Locking_Policy pragma applies to all the units in
-- this file, where x is the first character (upper case) of
-- the policy name (e.g. 'C' for Ceiling_Locking).
-- NO No object. This flag indicates that the units in this file
-- were not compiled to produce an object. This can occur as a
-- result of the use of -gnatc, or if no object can be produced
-- (e.g. when a package spec is compiled instead of the body,
-- or a subunit on its own). Note that in GNATprove mode, we
-- do produce an object. The object is not suitable for binding
-- and linking, but we do not set NO, instead we set GP.
-- NR No_Run_Time. Indicates that a pragma No_Run_Time applies
-- to all units in the file.
-- NS Normalize_Scalars pragma in effect for all units in
-- this file.
-- OH Pragma Default_Scalar_Storage_Order (High_Order_First) is
-- present in a configuration pragma file that applies.
-- OL Pragma Default_Scalar_Storage_Order (Low_Order_First) is
-- present in a configuration pragma file that applies.
-- Qx A valid Queueing_Policy pragma applies to all the units
-- in this file, where x is the first character (upper case)
-- of the policy name (e.g. 'P' for Priority_Queueing).
-- SL Indicates that the unit is an Interface to a Standalone
-- Library. Note that this indication is never given by the
-- compiler, but is added by the Project Manager in gnatmake
-- when an Interface ALI file is copied to the library
-- directory.
-- SS This unit references System.Secondary_Stack (that is,
-- the unit makes use of the secondary stack facilities).
-- Tx A valid Task_Dispatching_Policy pragma applies to all
-- the units in this file, where x is the first character
-- (upper case) of the corresponding policy name (e.g. 'F'
-- for FIFO_Within_Priorities).
-- UA Unreserve_All_Interrupts pragma was processed in one or
-- more units in this file
-- ZX Units in this file use zero-cost exceptions and have
-- generated exception tables. If ZX is not present, the
-- longjmp/setjmp exception scheme is in use.
-- Note that language defined units never output policy (Lx, Tx, Qx)
-- parameters. Language defined units must correctly handle all
-- possible cases. These values are checked for consistency by the
-- binder and then copied to the generated binder output file.
-- Note: The P line must be present. Even in Ignore_Errors mode, Scan_ALI
-- insists on finding a P line. So if changes are made to the ALI format,
-- they should not include removing the P line.
-- ---------------------
-- -- R Restrictions --
-- ---------------------
-- There are two forms for R lines, positional and named. The positional
-- notation is now considered obsolescent, it is not generated by the most
-- recent versions of the compiler except under control of the debug switch
-- -gnatdR, but is still recognized by the binder.
-- The recognition by the binder is to ease the transition, and better deal
-- with some cases of inconsistent builds using incompatible versions of
-- the compiler and binder. The named notation is the current preferred
-- approach.
-- Note that R lines are generated using the information in unit Rident,
-- and intepreted by the binder using the information in System.Rident.
-- Normally these two units should be effectively identical. However in
-- some cases of inconsistent builds, they may be different. This may lead
-- to binder diagnostics, which can be suppressed using the -C switch for
-- the binder, which results in ignoring unrecognized restrictions in the
-- ali files.
-- ---------------------------------------
-- -- R Restrictions (Positional Form) --
-- ---------------------------------------
-- The first R line records the status of restrictions generated by pragma
-- Restrictions encountered, as well as information on what the compiler
-- has been able to determine with respect to restrictions violations.
-- The format is:
-- R <<restriction-characters>> <<restriction-param-id-entries>>
-- The first parameter is a string of characters that records
-- information regarding restrictions that do not take parameter not
-- take parameter values. It is a string of characters, one character
-- for each value (in order) in All_Boolean_Restrictions. There are
-- three possible settings for each restriction:
-- r Restricted. Unit was compiled under control of a pragma
-- Restrictions for the corresponding restriction. In this case
-- the unit certainly does not violate the Restriction, since
-- this would have been detected by the compiler.
-- n Not used. The unit was not compiled under control of a pragma
-- Restrictions for the corresponding restriction, and does not
-- make any use of the referenced feature.
-- v Violated. The unit was not compiled under control of a pragma
-- Restrictions for the corresponding restriction, and it does
-- indeed use the referenced feature.
-- This information is used in the binder to check consistency, i.e. to
-- detect cases where one unit has "r" and another unit has "v", which
-- is not permitted, since these restrictions are partition-wide.
-- The second parameter, which immediately follows the first (with no
-- separating space) gives restriction information for identifiers for
-- which a parameter is given.
-- The parameter is a string of entries, one for each value in
-- Restrict.All_Parameter_Restrictions. Each entry has two components
-- in sequence, the first indicating whether or not there is a
-- restriction, and the second indicating whether or not the compiler
-- detected violations. In the boolean case it is not necessary to
-- separate these, since if a restriction is set, and violated, that is
-- an error. But in the parameter case, this is not true. For example,
-- we can have a unit with a pragma Restrictions (Max_Tasks => 4),
-- where the compiler can detect that there are exactly three tasks
-- declared. Both of these pieces of information must be passed to the
-- binder. The parameter of 4 is important in case the total number of
-- tasks in the partition is greater than 4. The parameter of 3 is
-- important in case some other unit has a restrictions pragma with
-- Max_Tasks=>2.
-- The component for the presence of restriction has one of two
-- possible forms:
-- n No pragma for this restriction is present in the set of units
-- for this ali file.
-- rN At least one pragma for this restriction is present in the
-- set of units for this ali file. The value N is the minimum
-- parameter value encountered in any such pragma. N is in the
-- range of Integer (a value larger than N'Last causes the
-- pragma to be ignored).
-- The component for the violation detection has one of three
-- possible forms:
-- n No violations were detected by the compiler
-- vN A violation was detected. N is either the maximum or total
-- count of violations (depending on the checking type) in all
-- the units represented by the ali file). Note that this
-- setting is only allowed for restrictions that are in
-- Checked_[Max|Sum]_Parameter_Restrictions. The value here is
-- known to be exact by the compiler and is in the range of
-- Natural.
-- vN+ A violation was detected. The compiler cannot determine
-- the exact count of violations, but it is at least N.
-- There are no spaces within the parameter string, so the entry
-- described above in the header of this section for Max_Tasks would
-- appear as the string r4v3.
-- Note: The restrictions line is required to be present. Even in
-- Ignore_Errors mode, Scan_ALI expects to find an R line and will
-- signal a fatal error if it is missing. This means that future
-- changes to the ALI file format must retain the R line.
-- ----------------------------------
-- -- R Restrictions (Named Form) --
-- ----------------------------------
-- The first R line for named form announces that named notation will be
-- used, and also assures that there is at least one R line present, which
-- makes parsing of ali files simpler. A blank line preceds the RN line.
-- RN
-- In named notation, the restrictions are given as a series of lines,
-- one per restrictions that is specified or violated (no information is
-- present for restrictions that are not specified or violated). In the
-- following name is the name of the restriction in all upper case.
-- For boolean restrictions, we have only two possibilities. A restrictions
-- pragma is present, or a violation is detected:
-- RR name
-- A restriction pragma is present for the named boolean restriction.
-- No violations were detected by the compiler (or the unit in question
-- would have been found to be illegal).
-- RV name
-- No restriction pragma is present for the named boolean restriction.
-- However, the compiler did detect one or more violations of this
-- restriction, which may require a binder consistency check. Note that
-- one case of a violation is the use of a Restriction_Set attribute for
-- the restriction that yielded False.
-- For the case of restrictions that take a parameter, we need both the
-- information from pragma if present, and the actual information about
-- what possible violations occur. For example, we can have a unit with
-- a pragma Restrictions (Max_Tasks => 4), where the compiler can detect
-- that there are exactly three tasks declared. Both of these pieces
-- of information must be passed to the binder. The parameter of 4 is
-- important in case the total number of tasks in the partition is greater
-- than 4. The parameter of 3 is important in case some other unit has a
-- restrictions pragma with Max_Tasks=>2.
-- RR name=N
-- A restriction pragma is present for the named restriction which is
-- one of the restrictions taking a parameter. The value N (a decimal
-- integer) is the value given in the restriction pragma.
-- RV name=N
-- A restriction pragma may or may not be present for the restriction
-- given by name (one of the restrictions taking a parameter). But in
-- either case, the compiler detected possible violations. N (a decimal
-- integer) is the maximum or total count of violations (depending
-- on the checking type) in all the units represented by the ali file).
-- The value here is known to be exact by the compiler and is in the
-- range of Natural. Note that if an RR line is present for the same
-- restriction, then the value in the RV line cannot exceed the value
-- in the RR line (since otherwise the compiler would have detected a
-- violation of the restriction).
-- RV name=N+
-- Similar to the above, but the compiler cannot determine the exact
-- count of violations, but it is at least N.
-- -------------------------------------------------
-- -- R Restrictions (No_Dependence Information) --
-- -------------------------------------------------
-- Subsequent R lines are present only if pragma Restriction No_Dependence
-- is used. There is one such line for each such pragma appearing in the
-- extended main unit. The format is:
-- R unit_name
-- Here the unit name is in all lower case. The components of the unit
-- name are separated by periods. The names themselves are in encoded
-- form, as documented in Namet.
-- -------------------------
-- -- I Interrupt States --
-- -------------------------
-- I interrupt-number interrupt-state line-number
-- This line records information from an Interrupt_State pragma. There
-- is one line for each separate pragma, and if no such pragmas are
-- used, then no I lines are present.
-- The interrupt-number is an unsigned positive integer giving the
-- value of the interrupt as defined in Ada.Interrupts.Names.
-- The interrupt-state is one of r/s/u for Runtime/System/User
-- The line number is an unsigned decimal integer giving the line
-- number of the corresponding Interrupt_State pragma. This is used
-- in consistency messages.
-- --------------------------------------
-- -- S Priority Specific Dispatching --
-- --------------------------------------
-- S policy_identifier first_priority last_priority line-number
-- This line records information from a Priority_Specific_Dispatching
-- pragma. There is one line for each separate pragma, and if no such
-- pragmas are used, then no S lines are present.
-- The policy_identifier is the first character (upper case) of the
-- corresponding policy name (e.g. 'F' for FIFO_Within_Priorities).
-- The first_priority and last_priority fields define the range of
-- priorities to which the specified dispatching policy apply.
-- The line number is an unsigned decimal integer giving the line
-- number of the corresponding Priority_Specific_Dispatching pragma.
-- This is used in consistency messages.
----------------------------
-- Compilation Unit Lines --
----------------------------
-- Following these header lines, a set of information lines appears for
-- each compilation unit that appears in the corresponding object file. In
-- particular, when a package body or subprogram body is compiled, there
-- will be two sets of information, one for the spec and one for the body,
-- with the entry for the body appearing first. This is the only case in
-- which a single ALI file contains more than one unit (in particular note
-- that subunits do *not* count as compilation units for this purpose, and
-- generate no library information, since they are inlined).
-- --------------------
-- -- U Unit Header --
-- --------------------
-- The lines for each compilation unit have the following form
-- U unit-name source-name version <<attributes>>
-- This line identifies the unit to which this section of the library
-- information file applies. The first three parameters are the unit
-- name in internal format, as described in package Uname, and the name
-- of the source file containing the unit.
-- Version is the version given as eight hexadecimal characters with
-- upper case letters. This value is the exclusive or of the source
-- checksums of the unit and all its semantically dependent units.
-- The <<attributes>> are a series of two letter codes indicating
-- information about the unit:
-- BD Unit does not have pragma Elaborate_Body, but the elaboration
-- circuit has determined that it would be a good idea if this
-- pragma were present, since the body of the package contains
-- elaboration code that modifies one or more variables in the
-- visible part of the package. The binder will try, but does
-- not promise, to keep the elaboration of the body close to
-- the elaboration of the spec.
-- DE Dynamic Elaboration. This unit was compiled with the dynamic
-- elaboration model, as set by either the -gnatE switch or
-- pragma Elaboration_Checks (Dynamic).
--
-- EB Unit has pragma Elaborate_Body, or is a generic instance that
-- has a body. Set for instances because RM 12.3(20) requires
-- that the body be immediately elaborated after the spec (we
-- would normally do that anyway, because elaborate spec and
-- body together whenever possible, and for an instance it is
-- always possible; however setting EB ensures that this is done
-- even when using the -p gnatbind switch).
-- EE Elaboration entity is present which must be set true when
-- the unit is elaborated. The name of the elaboration entity is
-- formed from the unit name in the usual way. If EE is present,
-- then this boolean must be set True as part of the elaboration
-- processing routine generated by the binder. Note that EE can
-- be set even if NE is set. This happens when the boolean is
-- needed solely for checking for the case of access before
-- elaboration.
-- GE Unit is a generic declaration, or corresponding body
--
-- IL Unit source uses a style with identifiers in all lower-case
-- IU (IL) or all upper case (IU). If the standard mixed-case usage
-- is detected, or the compiler cannot determine the style, then
-- no I parameter will appear.
-- IS Initialize_Scalars pragma applies to this unit, or else there
-- is at least one use of the Invalid_Value attribute.
-- KM Unit source uses a style with keywords in mixed case (KM)
-- KU or all upper case (KU). If the standard lower-case usage is
-- is detected, or the compiler cannot determine the style, then
-- no K parameter will appear.
-- NE Unit has no elaboration routine. All subprogram bodies and
-- specs are in this category. Package bodies and specs may or
-- may not have NE set, depending on whether or not elaboration
-- code is required. Set if N_Compilation_Unit node has flag
-- Has_No_Elaboration_Code set.
-- OL The units in this file are compiled with a local pragma
-- Optimize_Alignment, so no consistency requirement applies
-- to these units. All internal units have this status since
-- they have an automatic default of Optimize_Alignment (Off).
--
-- OO Optimize_Alignment (Off) is the default setting for all
-- units in this file. All files in the partition that specify
-- a default must specify the same default.
-- OS Optimize_Alignment (Space) is the default setting for all
-- units in this file. All files in the partition that specify
-- a default must specify the same default.
-- OT Optimize_Alignment (Time) is the default setting for all
-- units in this file. All files in the partition that specify
-- a default must specify the same default.
-- PF The unit has a library-level (package) finalizer
-- PK Unit is package, rather than a subprogram
-- PU Unit has pragma Pure
-- PR Unit has pragma Preelaborate
-- RA Unit declares a Remote Access to Class-Wide (RACW) type
-- RC Unit has pragma Remote_Call_Interface
-- RT Unit has pragma Remote_Types
-- SE Compilation of unit encountered one or more serious errors.
-- Normally the generation of an ALI file is suppressed if there
-- is a serious error, but this can be overridden with -gnatQ.
-- SP Unit has pragma Shared_Passive
-- SU Unit is a subprogram, rather than a package
-- The attributes may appear in any order, separated by spaces
-- -----------------------------
-- -- W, Y and Z Withed Units --
-- -----------------------------
-- Following each U line, is a series of lines of the form
-- W unit-name [source-name lib-name] [E] [EA] [ED] [AD]
-- or
-- Y unit-name [source-name lib-name] [E] [EA] [ED] [AD]
-- or
-- Z unit-name [source-name lib-name] [E] [EA] [ED] [AD]
-- One W line is present for each unit that is mentioned in an explicit
-- non-limited with clause by the current unit. One Y line is present
-- for each unit that is mentioned in an explicit limited with clause
-- by the current unit. One Z line is present for each unit that is
-- only implicitly withed by the current unit. The first parameter is
-- the unit name in internal format. The second parameter is the file
-- name of the file that must be compiled to compile this unit. It is
-- usually the file for the body, except for packages which have no
-- body. For units that need a body, if the source file for the body
-- cannot be found, the file name of the spec is used instead. The
-- third parameter is the file name of the library information file
-- that contains the results of compiling this unit. The optional
-- modifiers are used as follows:
-- E pragma Elaborate applies to this unit
-- EA pragma Elaborate_All applies to this unit
-- ED Elaborate_Desirable set for this unit, which means that there
-- is no Elaborate, but the analysis suggests that Program_Error
-- may be raised if the Elaborate conditions cannot be satisfied.
-- The binder will attempt to treat ED as E if it can.
-- AD Elaborate_All_Desirable set for this unit, which means that
-- there is no Elaborate_All, but the analysis suggests that
-- Program_Error may be raised if the Elaborate_All conditions
-- cannot be satisfied. The binder will attempt to treat AD as
-- EA if it can.
-- The parameter source-name and lib-name are omitted for the case of a
-- generic unit compiled with earlier versions of GNAT which did not
-- generate object or ali files for generics. For compatibility in the
-- bootstrap path we continue to omit these entries for predefined
-- generic units, even though we do now generate object and ali files.
-- However, in SPARK mode, we always generate source-name and lib-name
-- parameters. Bootstrap issues do not apply there, and we need this
-- information to properly compute frame conditions of subprograms.
-- The parameter source-name and lib-name are also omitted for the W
-- lines that result from use of a Restriction_Set attribute which gets
-- a result of False from a No_Dependence check, in the case where the
-- unit is not in the semantic closure. In such a case, the bare W
-- line is generated, but no D (dependency) line. This will make the
-- binder do the consistency check, but not include the unit in the
-- partition closure (unless it is properly With'ed somewhere).
-- -----------------------
-- -- L Linker_Options --
-- -----------------------
-- Following the W lines (if any, or the U line if not), are an optional
-- series of lines that indicates the usage of the pragma Linker_Options in
-- the associated unit. For each appearance of a pragma Linker_Options (or
-- Link_With) in the unit, a line is present with the form:
-- L "string"
-- where string is the string from the unit line enclosed in quotes.
-- Within the quotes the following can occur:
-- c graphic characters in range 20-7E other than " or {
-- "" indicating a single " character
-- {hh} indicating a character whose code is hex hh (0-9,A-F)
-- {00} [ASCII.NUL] is used as a separator character
-- to separate multiple arguments of a single
-- Linker_Options pragma.
-- For further details, see Stringt.Write_String_Table_Entry. Note that
-- wide characters in the form {hhhh} cannot be produced, since pragma
-- Linker_Option accepts only String, not Wide_String.
-- The L lines are required to appear in the same order as the
-- corresponding Linker_Options (or Link_With) pragmas appear in the
-- source file, so that this order is preserved by the binder in
-- constructing the set of linker arguments.
-- Note: Linker_Options lines never appear in the ALI file generated for
-- a predefined generic unit, and there is cicuitry in Sem_Prag to enforce
-- this restriction, which is needed because of not generating source name
-- and lib name parameters on the with lines for such files, as explained
-- above in the section on with lines.
-- --------------
-- -- N Notes --
-- --------------
-- The final section of unit-specific lines contains notes which record
-- annotations inserted in source code for processing by external tools
-- using pragmas. For each occurrence of any of these pragmas, a line is
-- generated with the following syntax:
-- N x<sloc> [<arg_id>:]<arg> ...
-- x is one of:
-- A pragma Annotate
-- C pragma Comment
-- I pragma Ident
-- T pragma Title
-- S pragma Subtitle
-- <sloc> is the source location of the pragma in line:col[:filename]
-- format. The file name is omitted if it is the same as the current
-- unit (it therefore appears explicitly in the case of pragmas
-- occurring in subunits, which do not have U sections of their own).
-- Successive entries record the pragma_argument_associations.
-- If a pragma argument identifier is present, the entry is prefixed
-- with the pragma argument identifier <arg_id> followed by a colon.
-- <arg> represents the pragma argument, and has the following
-- conventions:
-- - identifiers are output verbatim
-- - static string expressions are output as literals encoded as
-- for L lines
-- - static integer expressions are output as decimal literals
-- - any other expression is replaced by the placeholder "<expr>"
---------------------
-- Reference Lines --
---------------------
-- The reference lines contain information about references from any of the
-- units in the compilation (including body version and version attributes,
-- linker options pragmas and source dependencies).
-- ------------------------------------
-- -- E External Version References --
-- ------------------------------------
-- One of these lines is present for each use of 'Body_Version or 'Version
-- in any of the units of the compilation. These are used by the linker to
-- determine which version symbols must be output. The format is simply:
-- E name
-- where name is the external name, i.e. the unit name with either a S or a
-- B for spec or body version referenced (Body_Version always references
-- the body, Version references the Spec, except in the case of a reference
-- to a subprogram with no separate spec). Upper half and wide character
-- codes are encoded using the same method as in Namet (Uhh for upper half,
-- Whhhh for wide character, where hh are hex digits).
-- ---------------------
-- -- D Dependencies --
-- ---------------------
-- The dependency lines indicate the source files on which the compiled
-- units depend. This is used by the binder for consistency checking.
-- These lines are also referenced by the cross-reference information.
-- D source-name time-stamp checksum (sub)unit-name line:file-name
-- source-name also includes preprocessing data file and preprocessing
-- definition file. These preprocessing files may be given as full
-- path names instead of simple file names. If a full path name
-- includes a directory with spaces, the path name is quoted (quote
-- characters (") added at start and end, and any internal quotes are
-- doubled).
-- The time-stamp field contains the time stamp of the corresponding
-- source file. See types.ads for details on time stamp representation.
-- The checksum is an 8-hex digit representation of the source file
-- checksum, with letters given in lower case.
-- If the unit is not a subunit, the (sub)unit name is the unit name in
-- internal format, as described in package Uname. If the unit is a
-- subunit, the (sub)unit name is the fully qualified name of the
-- subunit in all lower case letters.
-- The line:file-name entry is present only if a Source_Reference
-- pragma appeared in the source file identified by source-name. In
-- this case, it gives the information from this pragma. Note that this
-- allows cross-reference information to be related back to the
-- original file. Note: the reason the line number comes first is that
-- a leading digit immediately identifies this as a Source_Reference
-- entry, rather than a subunit-name.
-- A line number of zero for line: in this entry indicates that there
-- is more than one source reference pragma. In this case, the line
-- numbers in the cross-reference are correct, and refer to the
-- original line number, but there is no information that allows a
-- reader of the ALI file to determine the exact mapping of physical
-- line numbers back to the original source.
-- Files with a zero checksum and a non-zero time stamp are in general
-- files on which the compilation depends but which are not Ada files
-- with further dependencies. This includes preprocessor data files
-- and preprocessor definition files.
-- Note: blank lines are ignored when the library information is read,
-- and separate sections of the file are separated by blank lines to
-- ease readability. Blanks between fields are also ignored.
-- For entries corresponding to files that were not present (and thus
-- resulted in error messages), or for files that are not part of the
-- dependency set, both the time stamp and checksum are set to all zero
-- characters. These dummy entries are ignored by the binder in
-- dependency checking, but must be present for proper interpretation
-- of the cross-reference data.
--------------------------
-- Cross-Reference Data --
--------------------------
-- The cross-reference data follows the dependency lines. See the spec of
-- Lib.Xref in file lib-xref.ads for details on the format of this data.
---------------------------------
-- Source Coverage Obligations --
---------------------------------
-- The Source Coverage Obligation (SCO) information follows the cross-
-- reference data. See the spec of Par_SCO in file par_sco.ads for full
-- details of the format.
---------------------------------------
-- SPARK Cross-Reference Information --
---------------------------------------
-- The SPARK cross-reference information follows the SCO information. See
-- the spec of SPARK_Xrefs in file spark_xrefs.ads for full details of the
-- format.
-------------------------------
-- ALI File Generation for C --
-------------------------------
-- The C compiler can also generate ALI files for use by the IDE's in
-- providing navigation services in C. These ALI files are a subset of
-- the specification above, lacking all Ada-specific output. Primarily
-- the IDE uses the cross-reference sections of such files.
----------------------
-- Global Variables --
----------------------
-- The table defined here stores one entry for each Interrupt_State pragma
-- encountered either in the main source or in an ancillary with'ed source.
-- Since interrupt state values have to be consistent across all units in a
-- partition, we detect inconsistencies at compile time when we can.
type Interrupt_State_Entry is record
Interrupt_Number : Pos;
-- Interrupt number value
Interrupt_State : Character;
-- Set to r/s/u for Runtime/System/User
Pragma_Loc : Source_Ptr;
-- Location of pragma setting this value in place
end record;
package Interrupt_States is new Table.Table (
Table_Component_Type => Interrupt_State_Entry,
Table_Index_Type => Nat,
Table_Low_Bound => 1,
Table_Initial => 30,
Table_Increment => 200,
Table_Name => "Name_Interrupt_States");
-- The table structure defined here stores one entry for each
-- Priority_Specific_Dispatching pragma encountered either in the main
-- source or in an ancillary with'ed source. Since have to be consistent
-- across all units in a partition, we may as well detect inconsistencies
-- at compile time when we can.
type Specific_Dispatching_Entry is record
Dispatching_Policy : Character;
-- First character (upper case) of the corresponding policy name
First_Priority : Nat;
-- Lower bound of the priority range to which the specified dispatching
-- policy applies.
Last_Priority : Nat;
-- Upper bound of the priority range to which the specified dispatching
-- policy applies.
Pragma_Loc : Source_Ptr;
-- Location of pragma setting this value in place
end record;
package Specific_Dispatching is new Table.Table (
Table_Component_Type => Specific_Dispatching_Entry,
Table_Index_Type => Nat,
Table_Low_Bound => 1,
Table_Initial => 10,
Table_Increment => 100,
Table_Name => "Name_Priority_Specific_Dispatching");
-----------------
-- Subprograms --
-----------------
procedure Ensure_System_Dependency;
-- This procedure ensures that a dependency is created on system.ads. Even
-- if there is no semantic dependency, Targparm has read the file to
-- acquire target parameters, so we need a source dependency.
procedure Write_ALI (Object : Boolean);
-- This procedure writes the library information for the current main unit
-- The Object parameter is true if an object file is created, and false
-- otherwise. Note that the pseudo-object file generated in GNATProve mode
-- does count as an object file from this point of view.
--
-- Note: in the case where we are not generating code (-gnatc mode), this
-- routine only writes an ALI file if it cannot find an existing up to
-- date ALI file. If it *can* find an existing up to date ALI file, then
-- it reads this file and sets the Lib.Compilation_Arguments table from
-- the A lines in this file.
procedure Add_Preprocessing_Dependency (S : Source_File_Index);
-- Indicate that there is a dependency to be added on a preprocessing data
-- file or on a preprocessing definition file.
end Lib.Writ;