gcc/ada/sinput.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                               S I N P U T                                --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                                                                          --
   9 --          Copyright (C) 1992-2005 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 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.                                                      --
  21 --                                                                          --
  22 -- As a special exception,  if other files  instantiate  generics from this --
  23 -- unit, or you link  this unit with other files  to produce an executable, --
  24 -- this  unit  does not  by itself cause  the resulting  executable  to  be --
  25 -- covered  by the  GNU  General  Public  License.  This exception does not --
  26 -- however invalidate  any other reasons why  the executable file  might be --
  27 -- covered by the  GNU Public License.                                      --
  28 --                                                                          --
  29 -- GNAT was originally developed  by the GNAT team at  New York University. --
  30 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  31 --                                                                          --
  32 ------------------------------------------------------------------------------
  33
  34 --  This package contains the input routines used for reading the
  35 --  input source file. The actual I/O routines are in OS_Interface,
  36 --  with this module containing only the system independent processing.
  37
  38 --  General Note: throughout the compiler, we use the term line or source
  39 --  line to refer to a physical line in the source, terminated by the end of
  40 --  physical line sequence.
  41
  42 --  There are two distinct concepts of line terminator in GNAT
  43
  44 --    A logical line terminator is what corresponds to the "end of a line" as
  45 --    described in RM 2.2 (13). Any of the characters FF, LF, CR or VT or any
  46 --    wide character that is a Line or Paragraph Separator acts as an end of
  47 --    logical line in this sense, and it is essentially irrelevant whether one
  48 --    or more appears in sequence (since if sequence of such characters is
  49 --    regarded as separate ends of line, then the intervening logical lines
  50 --    are null in any case).
  51
  52 --    A physical line terminator is a sequence of format effectors that is
  53 --    treated as ending a physical line. Physical lines have no Ada semantic
  54 --    significance, but they are significant for error reporting purposes,
  55 --    since errors are identified by line and column location.
  56
  57 --  In GNAT, a physical line is ended by any of the sequences LF, CR/LF, CR or
  58 --  LF/CR. LF is used in typical Unix systems, CR/LF in DOS systems, and CR
  59 --  alone in System 7. We don't know of any system using LF/CR, but it seems
  60 --  reasonable to include this case for consistency. In addition, we recognize
  61 --  any of these sequences in any of the operating systems, for better
  62 --  behavior in treating foreign files (e.g. a Unix file with LF terminators
  63 --  transferred to a DOS system). Finally, wide character codes in cagtegories
  64 --  Separator, Line and Separator, Paragraph are considered to be physical
  65 --  line terminators.
  66
  67 with Alloc;
  68 with Casing; use Casing;
  69 with Table;
  70 with Types;  use Types;
  71
  72 package Sinput is
  73
  74    type Type_Of_File is (
  75    --  Indicates type of file being read
  76
  77       Src,
  78       --  Normal Ada source file
  79
  80       Config,
  81       --  Configuration pragma file
  82
  83       Def,
  84       --  Preprocessing definition file
  85
  86       Preproc);
  87       --  Source file with preprocessing commands to be preprocessed
  88
  89    ----------------------------
  90    -- Source License Control --
  91    ----------------------------
  92
  93    --  The following type indicates the license state of a source if it
  94    --  is known.
  95
  96    type License_Type is
  97      (Unknown,
  98       --  Licensing status of this source unit is unknown
  99
 100       Restricted,
 101       --  This is a non-GPL'ed unit that is restricted from depending
 102       --  on GPL'ed units (e.g. proprietary code is in this category)
 103
 104       GPL,
 105       --  This file is licensed under the unmodified GPL. It is not allowed
 106       --  to depend on Non_GPL units, and Non_GPL units may not depend on
 107       --  this source unit.
 108
 109       Modified_GPL,
 110       --  This file is licensed under the GNAT modified GPL (see header of
 111       --  This file for wording of the modification). It may depend on other
 112       --  Modified_GPL units or on unrestricted units.
 113
 114       Unrestricted);
 115       --  The license on this file is permitted to depend on any other
 116       --  units, or have other units depend on it, without violating the
 117       --  license of this unit. Examples are public domain units, and
 118       --  units defined in the RM).
 119
 120    --  The above license status is checked when the appropriate check is
 121    --  activated and one source depends on another, and the licensing state
 122    --  of both files is known:
 123
 124    --  The prohibited combinations are:
 125
 126    --    Restricted file may not depend on GPL file
 127
 128    --    GPL file may not depend on Restricted file
 129
 130    --    Modified GPL file may not depend on Restricted file
 131    --    Modified_GPL file may not depend on GPL file
 132
 133    --  The reason for the last restriction here is that a client depending
 134    --  on a modified GPL file must be sure that the license condition is
 135    --  correct considered transitively.
 136
 137    --  The licensing status is determined either by the presence of a
 138    --  specific pragma License, or by scanning the header for a predefined
 139    --  file, or any file if compiling in -gnatg mode.
 140
 141    -----------------------
 142    -- Source File Table --
 143    -----------------------
 144
 145    --  The source file table has an entry for each source file read in for
 146    --  this run of the compiler. This table is (default) initialized when
 147    --  the compiler is loaded, and simply accumulates entries as compilation
 148    --  proceeds and various routines in Sinput and its child packages are
 149    --  called to load required source files.
 150
 151    --  Virtual entries are also created for generic templates when they are
 152    --  instantiated, as described in a separate section later on.
 153
 154    --  In the case where there are multiple main units (e.g. in the case of
 155    --  the cross-reference tool), this table is not reset between these units,
 156    --  so that a given source file is only read once if it is used by two
 157    --  separate main units.
 158
 159    --  The entries in the table are accessed using a Source_File_Index that
 160    --  ranges from 1 to Last_Source_File. Each entry has the following fields
 161
 162    --  Note: fields marked read-only are set by Sinput or one of its child
 163    --  packages when a source file table entry is created, and cannot be
 164    --  subsqently modified, or alternatively are set only by very special
 165    --  circumstances, documented in the comments.
 166
 167    --  File_Name : File_Name_Type (read-only)
 168    --    Name of the source file (simple name with no directory information)
 169
 170    --  Full_File_Name : File_Name_Type (read-only)
 171    --    Full file name (full name with directory info), used for generation
 172    --    of error messages, etc.
 173
 174    --  File_Type : Type_Of_File (read-only)
 175    --    Indicates type of file (source file, configuration pragmas file,
 176    --    preprocessor definition file, preprocessor input file).
 177
 178    --  Reference_Name : File_Name_Type (read-only)
 179    --    Name to be used for source file references in error messages where
 180    --    only the simple name of the file is required. Identical to File_Name
 181    --    unless pragma Source_Reference is used to change it. Only processing
 182    --    for the Source_Reference pragma circuit may set this field.
 183
 184    --  Full_Ref_Name : File_Name_Type (read-only)
 185    --    Name to be used for source file references in error messages where
 186    --    the full name of the file is required. Identical to Full_File_Name
 187    --    unless pragma Source_Reference is used to change it. Only processing
 188    --    for the Source_Reference pragma may set this field.
 189
 190    --  Debug_Source_Name : File_Name_Type (read-only)
 191    --    Name to be used for source file references in debugging information
 192    --    where only the simple name of the file is required. Identical to
 193    --    Reference_Name unless the -gnatD (debug source file) switch is used.
 194    --    Only processing in Sprint that generates this file is permitted to
 195    --    set this field.
 196
 197    --  Full_Debug_Name : File_Name_Type (read-only)
 198    --    Name to be used for source file references in debugging information
 199    --    where the full name of the file is required. This is identical to
 200    --    Full_Ref_Name unless the -gnatD (debug source file) switch is used.
 201    --    Only processing in Sprint that generates this file is permitted to
 202    --    set this field.
 203
 204    --  License : License_Type;
 205    --    License status of source file
 206
 207    --  Num_SRef_Pragmas : Nat;
 208    --    Number of source reference pragmas present in source file
 209
 210    --  First_Mapped_Line : Logical_Line_Number;
 211    --    This field stores logical line number of the first line in the
 212    --    file that is not a Source_Reference pragma. If no source reference
 213    --    pragmas are used, then the value is set to No_Line_Number.
 214
 215    --  Source_Text : Source_Buffer_Ptr (read-only)
 216    --    Text of source file. Note that every source file has a distinct set
 217    --    of non-overlapping logical bounds, so it is possible to determine
 218    --    which file is referenced from a given subscript (Source_Ptr) value.
 219
 220    --  Source_First : Source_Ptr; (read-only)
 221    --    Subscript of first character in Source_Text. Note that this cannot
 222    --    be obtained as Source_Text'First, because we use virtual origin
 223    --    addressing.
 224
 225    --  Source_Last : Source_Ptr; (read-only)
 226    --    Subscript of last character in Source_Text. Note that this cannot
 227    --    be obtained as Source_Text'Last, because we use virtual origin
 228    --    addressing, so this value is always Source_Ptr'Last.
 229
 230    --  Time_Stamp : Time_Stamp_Type; (read-only)
 231    --    Time stamp of the source file
 232
 233    --  Source_Checksum : Word;
 234    --    Computed checksum for contents of source file. See separate section
 235    --    later on in this spec for a description of the checksum algorithm.
 236
 237    --  Last_Source_Line : Physical_Line_Number;
 238    --    Physical line number of last source line. Whlie a file is being
 239    --    read, this refers to the last line scanned. Once a file has been
 240    --    completely scanned, it is the number of the last line in the file,
 241    --    and hence also gives the number of source lines in the file.
 242
 243    --  Keyword_Casing : Casing_Type;
 244    --    Casing style used in file for keyword casing. This is initialized
 245    --    to Unknown, and then set from the first occurrence of a keyword.
 246    --    This value is used only for formatting of error messages.
 247
 248    --  Identifier_Casing : Casing_Type;
 249    --    Casing style used in file for identifier casing. This is initialized
 250    --    to Unknown, and then set from an identifier in the program as soon as
 251    --    one is found whose casing is sufficiently clear to make a decision.
 252    --    This value is used for formatting of error messages, and also is used
 253    --    in the detection of keywords misused as identifiers.
 254
 255    --  Instantiation : Source_Ptr;
 256    --    Source file location of the instantiation if this source file entry
 257    --    represents a generic instantiation. Set to No_Location for the case
 258    --    of a normal non-instantiation entry. See section below for details.
 259    --    This field is read-only for clients.
 260
 261    --  Inlined_Body : Boolean;
 262    --    This can only be set True if Instantiation has a value other than
 263    --    No_Location. If true it indicates that the instantiation is actually
 264    --    an instance of an inlined body.
 265
 266    --  Template : Source_File_Index; (read-only)
 267    --    Source file index of the source file containing the template if this
 268    --    is a generic instantiation. Set to No_Source_File for the normal case
 269    --    of a non-instantiation entry. See Sinput-L for details.
 270
 271    --  The source file table is accessed by clients using the following
 272    --  subprogram interface:
 273
 274    subtype SFI is Source_File_Index;
 275
 276    System_Source_File_Index : SFI;
 277    --  The file system.ads is always read by the compiler to determine the
 278    --  settings of the target parameters in the private part of System. This
 279    --  variable records the source file index of system.ads. Typically this
 280    --  will be 1 since system.ads is read first.
 281
 282    function Debug_Source_Name (S : SFI) return File_Name_Type;
 283    function File_Name         (S : SFI) return File_Name_Type;
 284    function File_Type         (S : SFI) return Type_Of_File;
 285    function First_Mapped_Line (S : SFI) return Logical_Line_Number;
 286    function Full_Debug_Name   (S : SFI) return File_Name_Type;
 287    function Full_File_Name    (S : SFI) return File_Name_Type;
 288    function Full_Ref_Name     (S : SFI) return File_Name_Type;
 289    function Identifier_Casing (S : SFI) return Casing_Type;
 290    function Inlined_Body      (S : SFI) return Boolean;
 291    function Instantiation     (S : SFI) return Source_Ptr;
 292    function Keyword_Casing    (S : SFI) return Casing_Type;
 293    function Last_Source_Line  (S : SFI) return Physical_Line_Number;
 294    function License           (S : SFI) return License_Type;
 295    function Num_SRef_Pragmas  (S : SFI) return Nat;
 296    function Reference_Name    (S : SFI) return File_Name_Type;
 297    function Source_Checksum   (S : SFI) return Word;
 298    function Source_First      (S : SFI) return Source_Ptr;
 299    function Source_Last       (S : SFI) return Source_Ptr;
 300    function Source_Text       (S : SFI) return Source_Buffer_Ptr;
 301    function Template          (S : SFI) return Source_File_Index;
 302    function Time_Stamp        (S : SFI) return Time_Stamp_Type;
 303
 304    procedure Set_Keyword_Casing    (S : SFI; C : Casing_Type);
 305    procedure Set_Identifier_Casing (S : SFI; C : Casing_Type);
 306    procedure Set_License           (S : SFI; L : License_Type);
 307
 308    function Last_Source_File return Source_File_Index;
 309    --  Index of last source file table entry
 310
 311    function Num_Source_Files return Nat;
 312    --  Number of source file table entries
 313
 314    procedure Initialize;
 315    --  Initialize internal tables
 316
 317    procedure Lock;
 318    --  Lock internal tables
 319
 320    Main_Source_File : Source_File_Index := No_Source_File;
 321    --  This is set to the source file index of the main unit
 322
 323    -----------------------------
 324    -- Source_File_Index_Table --
 325    -----------------------------
 326
 327    --  The Get_Source_File_Index function is called very frequently. Earlier
 328    --  versions cached a single entry, but then reverted to a serial search,
 329    --  and this proved to be a significant source of inefficiency. To get
 330    --  around this, we use the following directly indexed array. The space
 331    --  of possible input values is a value of type Source_Ptr which is simply
 332    --  an Int value. The values in this space are allocated sequentially as
 333    --  new units are loaded.
 334
 335    --  The following table has an entry for each 4K range of possible
 336    --  Source_Ptr values. The value in the table is the lowest value
 337    --  Source_File_Index whose Source_Ptr range contains value in the
 338    --  range.
 339
 340    --  For example, the entry with index 4 in this table represents Source_Ptr
 341    --  values in the range 4*4096 .. 5*4096-1. The Source_File_Index value
 342    --  stored would be the lowest numbered source file with at least one byte
 343    --  in this range.
 344
 345    --  The algorithm used in Get_Source_File_Index is simply to access this
 346    --  table and then do a serial search starting at the given position. This
 347    --  will almost always terminate with one or two checks.
 348
 349    --  Note that this array is pretty large, but in most operating systems
 350    --  it will not be allocated in physical memory unless it is actually used.
 351
 352    Chunk_Power : constant := 12;
 353    Chunk_Size  : constant := 2 ** Chunk_Power;
 354    --  Change comments above if value changed. Note that Chunk_Size must
 355    --  be a power of 2 (to allow for efficient access to the table).
 356
 357    Source_File_Index_Table :
 358      array (Int range 0 .. Int'Last / Chunk_Size) of Source_File_Index;
 359
 360    procedure Set_Source_File_Index_Table (Xnew : Source_File_Index);
 361    --  Sets entries in the Source_File_Index_Table for the newly created
 362    --  Source_File table entry whose index is Xnew. The Source_First and
 363    --  Source_Last fields of this entry must be set before the call.
 364
 365    -----------------------
 366    -- Checksum Handling --
 367    -----------------------
 368
 369    --  As a source file is scanned, a checksum is computed by taking all the
 370    --  non-blank characters in the file, excluding comment characters, the
 371    --  minus-minus sequence starting a comment, and all control characters
 372    --  except ESC.
 373
 374    --  The checksum algorithm used is the standard CRC-32 algorithm, as
 375    --  implemented by System.CRC32, except that we do not bother with the
 376    --  final XOR with all 1 bits.
 377
 378    --  This algorithm ensures that the checksum includes all semantically
 379    --  significant aspects of the program represented by the source file,
 380    --  but is insensitive to layout, presence or contents of comments, wide
 381    --  character representation method, or casing conventions outside strings.
 382
 383    --  Scans.Checksum is initialized appropriately at the start of scanning
 384    --  a file, and copied into the Source_Checksum field of the file table
 385    --  entry when the end of file is encountered.
 386
 387    -------------------------------------
 388    -- Handling Generic Instantiations --
 389    -------------------------------------
 390
 391    --  As described in Sem_Ch12, a generic instantiation involves making a
 392    --  copy of the tree of the generic template. The source locations in
 393    --  this tree directly reference the source of the template. However it
 394    --  is also possible to find the location of the instantiation.
 395
 396    --  This is achieved as follows. When an instantiation occurs, a new entry
 397    --  is made in the source file table. This entry points to the same source
 398    --  text, i.e. the file that contains the instantiation, but has a distinct
 399    --  set of Source_Ptr index values. The separate range of Sloc values avoids
 400    --  confusion, and means that the Sloc values can still be used to uniquely
 401    --  identify the source file table entry. It is possible for both entries
 402    --  to point to the same text, because of the virtual origin pointers used
 403    --  in the source table.
 404
 405    --  The Instantiation field of this source file index entry, usually set
 406    --  to No_Source_File, instead contains the Sloc of the instantiation. In
 407    --  the case of nested instantiations, this Sloc may itself refer to an
 408    --  instantiation, so the complete chain can be traced.
 409
 410    --  Two routines are used to build these special entries in the source
 411    --  file table. Create_Instantiation_Source is first called to build
 412    --  the virtual source table entry for the instantiation, and then the
 413    --  Sloc values in the copy are adjusted using Adjust_Instantiation_Sloc.
 414    --  See child unit Sinput.L for details on these two routines.
 415
 416    -----------------
 417    -- Global Data --
 418    -----------------
 419
 420    Current_Source_File : Source_File_Index;
 421    --  Source_File table index of source file currently being scanned
 422
 423    Current_Source_Unit : Unit_Number_Type;
 424    --  Unit number of source file currently being scanned. The special value
 425    --  of No_Unit indicates that the configuration pragma file is currently
 426    --  being scanned (this has no entry in the unit table).
 427
 428    Source_gnat_adc : Source_File_Index := No_Source_File;
 429    --  This is set if a gnat.adc file is present to reference this file
 430
 431    Source : Source_Buffer_Ptr;
 432    --  Current source (copy of Source_File.Table (Current_Source_Unit).Source)
 433
 434    Internal_Source : aliased Source_Buffer (1 .. 81);
 435    --  This buffer is used internally in the compiler when the lexical analyzer
 436    --  is used to scan a string from within the compiler. The procedure is to
 437    --  establish Internal_Source_Ptr as the value of Source, set the string to
 438    --  be scanned, appropriately terminated, in this buffer, and set Scan_Ptr
 439    --  to point to the start of the buffer. It is a fatal error if the scanner
 440    --  signals an error while scanning a token in this internal buffer.
 441
 442    Internal_Source_Ptr : constant Source_Buffer_Ptr :=
 443                            Internal_Source'Unrestricted_Access;
 444    --  Pointer to internal source buffer
 445
 446    -----------------
 447    -- Subprograms --
 448    -----------------
 449
 450    procedure Backup_Line (P : in out Source_Ptr);
 451    --  Back up the argument pointer to the start of the previous line. On
 452    --  entry, P points to the start of a physical line in the source buffer.
 453    --  On return, P is updated to point to the start of the previous line.
 454    --  The caller has checked that a Line_Terminator character precedes P so
 455    --  that there definitely is a previous line in the source buffer.
 456
 457    procedure Build_Location_String (Loc : Source_Ptr);
 458    --  This function builds a string literal of the form "name:line",
 459    --  where name is the file name corresponding to Loc, and line is
 460    --  the line number. In the event that instantiations are involved,
 461    --  additional suffixes of the same form are appended after the
 462    --  separating string " instantiated at ". The returned string is
 463    --  stored in Name_Buffer, terminated by ASCII.Nul, with Name_Length
 464    --  indicating the length not including the terminating Nul.
 465
 466    function Get_Column_Number (P : Source_Ptr) return Column_Number;
 467    --  The ones-origin column number of the specified Source_Ptr value is
 468    --  determined and returned. Tab characters if present are assumed to
 469    --  represent the standard 1,9,17.. spacing pattern.
 470
 471    function Get_Logical_Line_Number
 472      (P : Source_Ptr) return Logical_Line_Number;
 473    --  The line number of the specified source position is obtained by
 474    --  doing a binary search on the source positions in the lines table
 475    --  for the unit containing the given source position. The returned
 476    --  value is the logical line number, already adjusted for the effect
 477    --  of source reference pragmas. If P refers to the line of a source
 478    --  reference pragma itself, then No_Line is returned. If no source
 479    --  reference pragmas have been encountered, the value returned is
 480    --  the same as the physical line number.
 481
 482    function Get_Physical_Line_Number
 483      (P : Source_Ptr) return Physical_Line_Number;
 484    --  The line number of the specified source position is obtained by
 485    --  doing a binary search on the source positions in the lines table
 486    --  for the unit containing the given source position. The returned
 487    --  value is the physical line number in the source being compiled.
 488
 489    function Get_Source_File_Index (S : Source_Ptr) return Source_File_Index;
 490    --  Return file table index of file identified by given source pointer
 491    --  value. This call must always succeed, since any valid source pointer
 492    --  value belongs to some previously loaded source file.
 493
 494    function Instantiation_Depth (S : Source_Ptr) return Nat;
 495    --  Determine instantiation depth for given Sloc value. A value of
 496    --  zero means that the given Sloc is not in an instantiation.
 497
 498    function Line_Start (P : Source_Ptr) return Source_Ptr;
 499    --  Finds the source position of the start of the line containing the
 500    --  given source location.
 501
 502    function Line_Start
 503      (L : Physical_Line_Number;
 504       S : Source_File_Index) return Source_Ptr;
 505    --  Finds the source position of the start of the given line in the
 506    --  given source file, using a physical line number to identify the line.
 507
 508    function Num_Source_Lines (S : Source_File_Index) return Nat;
 509    --  Returns the number of source lines (this is equivalent to reading
 510    --  the value of Last_Source_Line, but returns Nat rathern than a
 511    --  physical line number.
 512
 513    procedure Register_Source_Ref_Pragma
 514      (File_Name          : Name_Id;
 515       Stripped_File_Name : Name_Id;
 516       Mapped_Line        : Nat;
 517       Line_After_Pragma  : Physical_Line_Number);
 518    --  Register a source reference pragma, the parameter File_Name is the
 519    --  file name from the pragma, and Stripped_File_Name is this name with
 520    --  the directory information stripped. Both these parameters are set
 521    --  to No_Name if no file name parameter was given in the pragma.
 522    --  (which can only happen for the second and subsequent pragmas).
 523    --  Mapped_Line is the line number parameter from the pragma, and
 524    --  Line_After_Pragma is the physical line number of the line that
 525    --  follows the line containing the Source_Reference pragma.
 526
 527    function Original_Location (S : Source_Ptr) return Source_Ptr;
 528    --  Given a source pointer S, returns the corresponding source pointer
 529    --  value ignoring instantiation copies. For locations that do not
 530    --  correspond to instantiation copies of templates, the argument is
 531    --  returned unchanged. For locations that do correspond to copies of
 532    --  templates from instantiations, the location within the original
 533    --  template is returned. This is useful in canonicalizing locations.
 534
 535    function Instantiation_Location (S : Source_Ptr) return Source_Ptr;
 536    pragma Inline (Instantiation_Location);
 537    --  Given a source pointer S, returns the corresponding source pointer
 538    --  value of the instantiation if this location is within an instance.
 539    --  If S is not within an instance, then this returns No_Location.
 540
 541    function Top_Level_Location (S : Source_Ptr) return Source_Ptr;
 542    --  Given a source pointer S, returns the argument unchanged if it is
 543    --  not in an instantiation. If S is in an instantiation, then it returns
 544    --  the location of the top level instantiation, i.e. the outer level
 545    --  instantiation in the nested case.
 546
 547    function Physical_To_Logical
 548      (Line : Physical_Line_Number;
 549       S    : Source_File_Index) return Logical_Line_Number;
 550    --  Given a physical line number in source file whose source index is S,
 551    --  return the corresponding logical line number. If the physical line
 552    --  number is one containing a Source_Reference pragma, the result will
 553    --  be No_Line_Number.
 554
 555    procedure Skip_Line_Terminators
 556      (P        : in out Source_Ptr;
 557       Physical : out Boolean);
 558    --  On entry, P points to a line terminator that has been encountered,
 559    --  which is one of FF,LF,VT,CR or a wide character sequence whose value is
 560    --  in category Separator,Line or Separator,Paragraph. The purpose of this
 561    --  P points just past the character that was scanned. The purpose of this
 562    --  routine is to distinguish physical and logical line endings. A physical
 563    --  line ending is one of:
 564    --
 565    --     CR on its own (MAC System 7)
 566    --     LF on its own (Unix and unix-like systems)
 567    --     CR/LF (DOS, Windows)
 568    --     LF/CR (not used, but recognized in any case)
 569    --     Wide character in Separator,Line or Separator,Paragraph category
 570    --
 571    --  A logical line ending (that is not a physical line ending) is one of:
 572    --
 573    --     VT on its own
 574    --     FF on its own
 575    --
 576    --  On return, P is bumped past the line ending sequence (one of the above
 577    --  seven possibilities). Physical is set to True to indicate that a
 578    --  physical end of line was encountered, in which case this routine also
 579    --  makes sure that the lines table for the current source file has an
 580    --  appropriate entry for the start of the new physical line.
 581
 582    function Source_Offset (S : Source_Ptr) return Nat;
 583    --  Returns the zero-origin offset of the given source location from the
 584    --  start of its corresponding unit. This is used for creating canonical
 585    --  names in some situations.
 586
 587    procedure Write_Location (P : Source_Ptr);
 588    --  Writes out a string of the form fff:nn:cc, where fff, nn, cc are the
 589    --  file name, line number and column corresponding to the given source
 590    --  location. No_Location and Standard_Location appear as the strings
 591    --  <no location> and <standard location>. If the location is within an
 592    --  instantiation, then the instance location is appended, enclosed in
 593    --  square brackets (which can nest if necessary). Note that this routine
 594    --  is used only for internal compiler debugging output purposes (which
 595    --  is why the somewhat cryptic use of brackets is acceptable).
 596
 597    procedure wl (P : Source_Ptr);
 598    pragma Export (Ada, wl);
 599    --  Equivalent to Write_Location (P); Write_Eol; for calls from GDB
 600
 601    procedure Write_Time_Stamp (S : Source_File_Index);
 602    --  Writes time stamp of specified file in YY-MM-DD HH:MM.SS format
 603
 604    procedure Tree_Read;
 605    --  Initializes internal tables from current tree file using the relevant
 606    --  Table.Tree_Read routines.
 607
 608    procedure Tree_Write;
 609    --  Writes out internal tables to current tree file using the relevant
 610    --  Table.Tree_Write routines.
 611
 612 private
 613    pragma Inline (File_Name);
 614    pragma Inline (First_Mapped_Line);
 615    pragma Inline (Full_File_Name);
 616    pragma Inline (Identifier_Casing);
 617    pragma Inline (Instantiation);
 618    pragma Inline (Keyword_Casing);
 619    pragma Inline (Last_Source_Line);
 620    pragma Inline (Last_Source_File);
 621    pragma Inline (License);
 622    pragma Inline (Num_SRef_Pragmas);
 623    pragma Inline (Num_Source_Files);
 624    pragma Inline (Num_Source_Lines);
 625    pragma Inline (Reference_Name);
 626    pragma Inline (Set_Keyword_Casing);
 627    pragma Inline (Set_Identifier_Casing);
 628    pragma Inline (Source_First);
 629    pragma Inline (Source_Last);
 630    pragma Inline (Source_Text);
 631    pragma Inline (Template);
 632    pragma Inline (Time_Stamp);
 633
 634    -------------------------
 635    -- Source_Lines Tables --
 636    -------------------------
 637
 638    type Lines_Table_Type is
 639      array (Physical_Line_Number) of Source_Ptr;
 640    --  Type used for lines table. The entries are indexed by physical line
 641    --  numbers. The values are the starting Source_Ptr values for the start
 642    --  of the corresponding physical line. Note that we make this a bogus
 643    --  big array, sized as required, so that we avoid the use of fat pointers.
 644
 645    type Lines_Table_Ptr is access all Lines_Table_Type;
 646    --  Type used for pointers to line tables
 647
 648    type Logical_Lines_Table_Type is
 649      array (Physical_Line_Number) of Logical_Line_Number;
 650    --  Type used for logical lines table. This table is used if a source
 651    --  reference pragma is present. It is indexed by physical line numbers,
 652    --  and contains the corresponding logical line numbers. An entry that
 653    --  corresponds to a source reference pragma is set to No_Line_Number.
 654    --  Note that we make this a bogus big array, sized as required, so that
 655    --  we avoid the use of fat pointers.
 656
 657    type Logical_Lines_Table_Ptr is access all Logical_Lines_Table_Type;
 658    --  Type used for pointers to logical line tables.
 659
 660    -----------------------
 661    -- Source_File Table --
 662    -----------------------
 663
 664    --  See earlier descriptions for meanings of public fields
 665
 666    type Source_File_Record is record
 667
 668       File_Name         : File_Name_Type;
 669       File_Type         : Type_Of_File;
 670       Reference_Name    : File_Name_Type;
 671       Debug_Source_Name : File_Name_Type;
 672       Full_Debug_Name   : File_Name_Type;
 673       Full_File_Name    : File_Name_Type;
 674       Full_Ref_Name     : File_Name_Type;
 675       Inlined_Body      : Boolean;
 676       License           : License_Type;
 677       Num_SRef_Pragmas  : Nat;
 678       First_Mapped_Line : Logical_Line_Number;
 679       Source_Text       : Source_Buffer_Ptr;
 680       Source_First      : Source_Ptr;
 681       Source_Last       : Source_Ptr;
 682       Time_Stamp        : Time_Stamp_Type;
 683       Source_Checksum   : Word;
 684       Last_Source_Line  : Physical_Line_Number;
 685       Keyword_Casing    : Casing_Type;
 686       Identifier_Casing : Casing_Type;
 687       Instantiation     : Source_Ptr;
 688       Template          : Source_File_Index;
 689
 690       --  The following fields are for internal use only (i.e. only in the
 691       --  body of Sinput or its children, with no direct access by clients).
 692
 693       Sloc_Adjust : Source_Ptr;
 694       --  A value to be added to Sloc values for this file to reference the
 695       --  corresponding lines table. This is zero for the non-instantiation
 696       --  case, and set so that the adition references the ultimate template
 697       --  for the instantiation case. See Sinput-L for further details.
 698
 699       Lines_Table : Lines_Table_Ptr;
 700       --  Pointer to lines table for this source. Updated as additional
 701       --  lines are accessed using the Skip_Line_Terminators procedure.
 702       --  Note: the lines table for an instantiation entry refers to the
 703       --  original line numbers of the template see Sinput-L for details.
 704
 705       Logical_Lines_Table : Logical_Lines_Table_Ptr;
 706       --  Pointer to logical lines table for this source. Non-null only if
 707       --  a source reference pragma has been processed. Updated as lines
 708       --  are accessed using the Skip_Line_Terminators procedure.
 709
 710       Lines_Table_Max : Physical_Line_Number;
 711       --  Maximum subscript values for currently allocated Lines_Table
 712       --  and (if present) the allocated Logical_Lines_Table. The value
 713       --  Max_Source_Line gives the maximum used value, this gives the
 714       --  maximum allocated value.
 715
 716    end record;
 717
 718    package Source_File is new Table.Table (
 719      Table_Component_Type => Source_File_Record,
 720      Table_Index_Type     => Source_File_Index,
 721      Table_Low_Bound      => 1,
 722      Table_Initial        => Alloc.Source_File_Initial,
 723      Table_Increment      => Alloc.Source_File_Increment,
 724      Table_Name           => "Source_File");
 725
 726    -----------------
 727    -- Subprograms --
 728    -----------------
 729
 730    procedure Alloc_Line_Tables
 731      (S       : in out Source_File_Record;
 732       New_Max : Nat);
 733    --  Allocate or reallocate the lines table for the given source file so
 734    --  that it can accommodate at least New_Max lines. Also allocates or
 735    --  reallocates logical lines table if source ref pragmas are present.
 736
 737    procedure Add_Line_Tables_Entry
 738      (S : in out Source_File_Record;
 739       P : Source_Ptr);
 740    --  Increment line table size by one (reallocating the lines table if
 741    --  needed) and set the new entry to contain the value P. Also bumps
 742    --  the Source_Line_Count field. If source reference pragmas are
 743    --  present, also increments logical lines table size by one, and
 744    --  sets new entry.
 745
 746    procedure Trim_Lines_Table (S : Source_File_Index);
 747    --  Set lines table size for entry S in the source file table to
 748    --  correspond to the current value of Num_Source_Lines, releasing
 749    --  any unused storage. This is used by Sinput.L and Sinput.D.
 750
 751 end Sinput;