gcc/ada/gnatchop.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                             G N A T C H O P                              --
   6 --                                                                          --
   7 --                                 B o d y                                  --
   8 --                                                                          --
   9 --          Copyright (C) 1998-2019, Free Software Foundation, Inc.         --
  10 --                                                                          --
  11 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  12 -- terms of the  GNU General Public License as published  by the Free Soft- --
  13 -- ware  Foundation;  either version 3,  or (at your option) any later ver- --
  14 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  15 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  16 -- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
  17 -- for  more details.  You should have  received  a copy of the GNU General --
  18 -- Public License  distributed with GNAT; see file COPYING3.  If not, go to --
  19 -- http://www.gnu.org/licenses for a complete copy of the license.          --
  20 --                                                                          --
  21 -- GNAT was originally developed  by the GNAT team at  New York University. --
  22 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  23 --                                                                          --
  24 ------------------------------------------------------------------------------
  25
  26 with Ada.Characters.Conversions; use Ada.Characters.Conversions;
  27 with Ada.Command_Line;           use Ada.Command_Line;
  28 with Ada.Directories;            use Ada.Directories;
  29 with Ada.Streams.Stream_IO;      use Ada.Streams;
  30 with Ada.Text_IO;                use Ada.Text_IO;
  31 with System.CRTL;                use System; use System.CRTL;
  32
  33 with GNAT.Byte_Order_Mark;       use GNAT.Byte_Order_Mark;
  34 with GNAT.Command_Line;          use GNAT.Command_Line;
  35 with GNAT.OS_Lib;                use GNAT.OS_Lib;
  36 with GNAT.Heap_Sort_G;
  37 with GNAT.Table;
  38
  39 with Switch;                     use Switch;
  40 with Types;
  41
  42 procedure Gnatchop is
  43
  44    Config_File_Name : constant String_Access := new String'("gnat.adc");
  45    --  The name of the file holding the GNAT configuration pragmas
  46
  47    Gcc : String_Access := new String'("gcc");
  48    --  May be modified by switch --GCC=
  49
  50    Gcc_Set : Boolean := False;
  51    --  True if a switch --GCC= is used
  52
  53    Gnat_Cmd : String_Access;
  54    --  Command to execute the GNAT compiler
  55
  56    Gnat_Args : Argument_List_Access :=
  57                  new Argument_List'
  58                    (new String'("-c"),
  59                     new String'("-x"),
  60                     new String'("ada"),
  61                     new String'("-gnats"),
  62                     new String'("-gnatu"));
  63    --  Arguments used in Gnat_Cmd call
  64
  65    EOF : constant Character := Character'Val (26);
  66    --  Special character to signal end of file. Not required in input files,
  67    --  but properly treated if present. Not generated in output files except
  68    --  as a result of copying input file.
  69
  70    BOM_Length : Natural := 0;
  71    --  Reset to non-zero value if BOM detected at start of file
  72
  73    --------------------
  74    -- File arguments --
  75    --------------------
  76
  77    subtype File_Num is Natural;
  78    subtype File_Offset is Natural;
  79
  80    type File_Entry is record
  81       Name : String_Access;
  82       --  Name of chop file or directory
  83
  84       SR_Name : String_Access;
  85       --  Null unless the chop file starts with a source reference pragma
  86       --  in which case this field points to the file name from this pragma.
  87    end record;
  88
  89    package File is new GNAT.Table
  90      (Table_Component_Type => File_Entry,
  91       Table_Index_Type     => File_Num,
  92       Table_Low_Bound      => 1,
  93       Table_Initial        => 100,
  94       Table_Increment      => 100);
  95
  96    Directory : String_Access;
  97    --  Record name of directory, or a null string if no directory given
  98
  99    Compilation_Mode  : Boolean := False;
 100    Overwrite_Files   : Boolean := False;
 101    Preserve_Mode     : Boolean := False;
 102    Quiet_Mode        : Boolean := False;
 103    Source_References : Boolean := False;
 104    Verbose_Mode      : Boolean := False;
 105    Exit_On_Error     : Boolean := False;
 106    --  Global options
 107
 108    Write_gnat_adc : Boolean := False;
 109    --  Gets set true if we append to gnat.adc or create a new gnat.adc.
 110    --  Used to inhibit complaint about no units generated.
 111
 112    ---------------
 113    -- Unit list --
 114    ---------------
 115
 116    type Line_Num is new Natural;
 117    --  Line number (for source reference pragmas)
 118
 119    type Unit_Count_Type  is new Integer;
 120    subtype Unit_Num      is Unit_Count_Type range 1 .. Unit_Count_Type'Last;
 121    --  Used to refer to unit number in unit table
 122
 123    type SUnit_Num is new Integer;
 124    --  Used to refer to entry in sorted units table. Note that entry
 125    --  zero is only for use by Heapsort, and is not otherwise referenced.
 126
 127    type Unit_Kind is (Unit_Spec, Unit_Body, Config_Pragmas);
 128
 129    --  Structure to contain all necessary information for one unit.
 130    --  Entries are also temporarily used to record config pragma sequences.
 131
 132    type Unit_Info is record
 133       File_Name : String_Access;
 134       --  File name from GNAT output line
 135
 136       Chop_File : File_Num;
 137       --  File number in chop file sequence
 138
 139       Start_Line : Line_Num;
 140       --  Line number from GNAT output line
 141
 142       Offset : File_Offset;
 143       --  Offset name from GNAT output line
 144
 145       SR_Present : Boolean;
 146       --  Set True if SR parameter present
 147
 148       Length : File_Offset;
 149       --  A length of 0 means that the Unit is the last one in the file
 150
 151       Kind : Unit_Kind;
 152       --  Indicates kind of unit
 153
 154       Sorted_Index : SUnit_Num;
 155       --  Index of unit in sorted unit list
 156
 157       Bufferg : String_Access;
 158       --  Pointer to buffer containing configuration pragmas to be prepended.
 159       --  Null if no pragmas to be prepended.
 160    end record;
 161
 162    --  The following table stores the unit offset information
 163
 164    package Unit is new GNAT.Table
 165      (Table_Component_Type => Unit_Info,
 166       Table_Index_Type     => Unit_Count_Type,
 167       Table_Low_Bound      => 1,
 168       Table_Initial        => 500,
 169       Table_Increment      => 100);
 170
 171    --  The following table is used as a sorted index to the Unit.Table.
 172    --  The entries in Unit.Table are not moved, instead we just shuffle
 173    --  the entries in Sorted_Units. Note that the zeroeth entry in this
 174    --  table is used by GNAT.Heap_Sort_G.
 175
 176    package Sorted_Units is new GNAT.Table
 177      (Table_Component_Type => Unit_Num,
 178       Table_Index_Type     => SUnit_Num,
 179       Table_Low_Bound      => 0,
 180       Table_Initial        => 500,
 181       Table_Increment      => 100);
 182
 183    function Is_Duplicated (U : SUnit_Num) return Boolean;
 184    --  Returns true if U is duplicated by a later unit.
 185    --  Note that this function returns false for the last entry.
 186
 187    procedure Sort_Units;
 188    --  Sort units and set up sorted unit table
 189
 190    ----------------------
 191    -- File_Descriptors --
 192    ----------------------
 193
 194    function dup  (handle   : File_Descriptor) return File_Descriptor;
 195    function dup2 (from, to : File_Descriptor) return File_Descriptor;
 196
 197    ---------------------
 198    -- Local variables --
 199    ---------------------
 200
 201    Warning_Count : Natural := 0;
 202    --  Count of warnings issued so far
 203
 204    -----------------------
 205    -- Local subprograms --
 206    -----------------------
 207
 208    procedure Error_Msg (Message : String; Warning : Boolean := False);
 209    --  Produce an error message on standard error output
 210
 211    function Files_Exist return Boolean;
 212    --  Check Unit.Table for possible file names that already exist
 213    --  in the file system. Returns true if files exist, False otherwise
 214
 215    function Get_Maximum_File_Name_Length return Integer;
 216    pragma Import (C, Get_Maximum_File_Name_Length,
 217                  "__gnat_get_maximum_file_name_length");
 218    --  Function to get maximum file name length for system
 219
 220    Maximum_File_Name_Length : constant Integer := Get_Maximum_File_Name_Length;
 221    Maximum_File_Name_Length_String : constant String :=
 222                                        Integer'Image
 223                                          (Maximum_File_Name_Length);
 224
 225    function Locate_Executable
 226      (Program_Name    : String;
 227       Look_For_Prefix : Boolean := True) return String_Access;
 228    --  Locate executable for given program name. This takes into account
 229    --  the target-prefix of the current command, if Look_For_Prefix is True.
 230
 231    subtype EOL_Length is Natural range 0 .. 2;
 232    --  Possible lengths of end of line sequence
 233
 234    type EOL_String (Len : EOL_Length := 0) is record
 235       Str : String (1 .. Len);
 236    end record;
 237
 238    function Get_EOL
 239      (Source : not null access String;
 240       Start  : Positive) return EOL_String;
 241    --  Return the line terminator used in the passed string
 242
 243    procedure Parse_EOL
 244      (Source : not null access String;
 245       Ptr    : in out Positive);
 246    --  On return Source (Ptr) is the first character of the next line
 247    --  or EOF. Source.all must be terminated by EOF.
 248
 249    function Parse_File (Num : File_Num) return Boolean;
 250    --  Calls the GNAT compiler to parse the given source file and parses the
 251    --  output using Parse_Offset_Info. Returns True if parse operation
 252    --  completes, False if some system error (e.g. failure to read the
 253    --  offset information) occurs.
 254
 255    procedure Parse_Offset_Info
 256      (Chop_File : File_Num;
 257       Source    : not null access String);
 258    --  Parses the output of the compiler indicating the offsets and names of
 259    --  the compilation units in Chop_File.
 260
 261    procedure Parse_Token
 262      (Source    : not null access String;
 263       Ptr       : in out Positive;
 264       Token_Ptr : out Positive);
 265    --  Skips any separators and stores the start of the token in Token_Ptr.
 266    --  Then stores the position of the next separator in Ptr. On return
 267    --  Source (Token_Ptr .. Ptr - 1) is the token.
 268
 269    procedure Read_File
 270      (FD       : File_Descriptor;
 271       Contents : out String_Access;
 272       Success  : out Boolean);
 273    --  Reads file associated with FS into the newly allocated string Contents.
 274    --  Success is true iff the number of bytes read is equal to the file size.
 275
 276    function Report_Duplicate_Units return Boolean;
 277    --  Output messages about duplicate units in the input files in Unit.Table
 278    --  Returns True if any duplicates found, False if no duplicates found.
 279
 280    function Scan_Arguments return Boolean;
 281    --  Scan command line options and set global variables accordingly.
 282    --  Also scan out file and directory arguments. Returns True if scan
 283    --  was successful, and False if the scan fails for any reason.
 284
 285    procedure Usage;
 286    --  Output message on standard output describing syntax of gnatchop command
 287
 288    procedure Warning_Msg (Message : String);
 289    --  Output a warning message on standard error and update warning count
 290
 291    function Write_Chopped_Files (Input : File_Num) return Boolean;
 292    --  Write all units that result from chopping the Input file
 293
 294    procedure Write_Config_File (Input : File_Num; U : Unit_Num);
 295    --  Call to write configuration pragmas (append them to gnat.adc). Input is
 296    --  the file number for the chop file and U identifies the unit entry for
 297    --  the configuration pragmas.
 298
 299    function Get_Config_Pragmas
 300      (Input : File_Num;
 301       U     : Unit_Num) return String_Access;
 302    --  Call to read configuration pragmas from given unit entry, and return a
 303    --  buffer containing the pragmas to be appended to following units. Input
 304    --  is the file number for the chop file and U identifies the unit entry for
 305    --  the configuration pragmas.
 306
 307    procedure Write_Source_Reference_Pragma
 308      (Info    : Unit_Info;
 309       Line    : Line_Num;
 310       File    : Stream_IO.File_Type;
 311       EOL     : EOL_String;
 312       Success : in out Boolean);
 313    --  If Success is True on entry, writes a source reference pragma using
 314    --  the chop file from Info, and the given line number. On return Success
 315    --  indicates whether the write succeeded. If Success is False on entry,
 316    --  or if the global flag Source_References is False, then the call to
 317    --  Write_Source_Reference_Pragma has no effect. EOL indicates the end
 318    --  of line sequence to be written at the end of the pragma.
 319
 320    procedure Write_Unit
 321      (Source    : not null access String;
 322       Num       : Unit_Num;
 323       TS_Time   : OS_Time;
 324       Write_BOM : Boolean;
 325       Success   : out Boolean);
 326    --  Write one compilation unit of the source to file. Source is the pointer
 327    --  to the input string, Num is the unit number, TS_Time is the timestamp,
 328    --  Write_BOM is set True to write a UTF-8 BOM at the start of the file.
 329    --  Success is set True unless the write attempt fails.
 330
 331    ---------
 332    -- dup --
 333    ---------
 334
 335    function dup (handle : File_Descriptor) return File_Descriptor is
 336    begin
 337       return File_Descriptor (System.CRTL.dup (int (handle)));
 338    end dup;
 339
 340    ----------
 341    -- dup2 --
 342    ----------
 343
 344    function dup2 (from, to : File_Descriptor) return File_Descriptor is
 345    begin
 346       return File_Descriptor (System.CRTL.dup2 (int (from), int (to)));
 347    end dup2;
 348
 349    ---------------
 350    -- Error_Msg --
 351    ---------------
 352
 353    procedure Error_Msg (Message : String; Warning : Boolean := False) is
 354    begin
 355       Put_Line (Standard_Error, Message);
 356
 357       if not Warning then
 358          Set_Exit_Status (Failure);
 359
 360          if Exit_On_Error then
 361             raise Types.Terminate_Program;
 362          end if;
 363       end if;
 364    end Error_Msg;
 365
 366    -----------------
 367    -- Files_Exist --
 368    -----------------
 369
 370    function Files_Exist return Boolean is
 371       Exists : Boolean := False;
 372
 373    begin
 374       for SNum in 1 .. SUnit_Num (Unit.Last) loop
 375
 376          --  Only check and report for the last instance of duplicated files
 377
 378          if not Is_Duplicated (SNum) then
 379             declare
 380                Info : constant Unit_Info :=
 381                         Unit.Table (Sorted_Units.Table (SNum));
 382
 383             begin
 384                if Is_Writable_File (Info.File_Name.all) then
 385                   Error_Msg (Info.File_Name.all
 386                               & " already exists, use -w to overwrite");
 387                   Exists := True;
 388                end if;
 389             end;
 390          end if;
 391       end loop;
 392
 393       return Exists;
 394    end Files_Exist;
 395
 396    ------------------------
 397    -- Get_Config_Pragmas --
 398    ------------------------
 399
 400    function Get_Config_Pragmas
 401      (Input : File_Num;
 402       U     : Unit_Num) return String_Access
 403    is
 404       Info    : Unit_Info renames Unit.Table (U);
 405       FD      : File_Descriptor;
 406       Name    : aliased constant String :=
 407                   File.Table (Input).Name.all & ASCII.NUL;
 408       Length  : File_Offset;
 409       Buffer  : String_Access;
 410       Result  : String_Access;
 411
 412       Success : Boolean;
 413       pragma Warnings (Off, Success);
 414
 415    begin
 416       FD := Open_Read (Name'Address, Binary);
 417
 418       if FD = Invalid_FD then
 419          Error_Msg ("cannot open " & File.Table (Input).Name.all);
 420          return null;
 421       end if;
 422
 423       Read_File (FD, Buffer, Success);
 424
 425       --  A length of 0 indicates that the rest of the file belongs to
 426       --  this unit. The actual length must be calculated now. Take into
 427       --  account that the last character (EOF) must not be written.
 428
 429       if Info.Length = 0 then
 430          Length := Buffer'Last - (Buffer'First + Info.Offset);
 431       else
 432          Length := Info.Length;
 433       end if;
 434
 435       Result := new String'(Buffer (1 .. Length));
 436       Close (FD);
 437       return Result;
 438    end Get_Config_Pragmas;
 439
 440    -------------
 441    -- Get_EOL --
 442    -------------
 443
 444    function Get_EOL
 445      (Source : not null access String;
 446       Start  : Positive) return EOL_String
 447    is
 448       Ptr   : Positive := Start;
 449       First : Positive;
 450       Last  : Natural;
 451
 452    begin
 453       --  Skip to end of line
 454
 455       while Source (Ptr) /= ASCII.CR and then
 456             Source (Ptr) /= ASCII.LF and then
 457             Source (Ptr) /= EOF
 458       loop
 459          Ptr := Ptr + 1;
 460       end loop;
 461
 462       Last  := Ptr;
 463
 464       if Source (Ptr) /= EOF then
 465
 466          --  Found CR or LF
 467
 468          First := Ptr;
 469
 470       else
 471          First := Ptr + 1;
 472       end if;
 473
 474       --  Recognize CR/LF
 475
 476       if Source (Ptr) = ASCII.CR and then Source (Ptr + 1) = ASCII.LF then
 477          Last := First + 1;
 478       end if;
 479
 480       return (Len => Last + 1 - First, Str => Source (First .. Last));
 481    end Get_EOL;
 482
 483    -------------------
 484    -- Is_Duplicated --
 485    -------------------
 486
 487    function Is_Duplicated (U : SUnit_Num) return Boolean is
 488    begin
 489       return U < SUnit_Num (Unit.Last)
 490         and then
 491           Unit.Table (Sorted_Units.Table (U)).File_Name.all =
 492           Unit.Table (Sorted_Units.Table (U + 1)).File_Name.all;
 493    end Is_Duplicated;
 494
 495    -----------------------
 496    -- Locate_Executable --
 497    -----------------------
 498
 499    function Locate_Executable
 500      (Program_Name    : String;
 501       Look_For_Prefix : Boolean := True) return String_Access
 502    is
 503       Gnatchop_Str    : constant String := "gnatchop";
 504       Current_Command : constant String := Normalize_Pathname (Command_Name);
 505       End_Of_Prefix   : Natural;
 506       Start_Of_Prefix : Positive;
 507       Start_Of_Suffix : Positive;
 508       Result          : String_Access;
 509
 510    begin
 511       Start_Of_Prefix := Current_Command'First;
 512       Start_Of_Suffix := Current_Command'Last + 1;
 513       End_Of_Prefix   := Start_Of_Prefix - 1;
 514
 515       if Look_For_Prefix then
 516
 517          --  Find Start_Of_Prefix
 518
 519          for J in reverse Current_Command'Range loop
 520             if Current_Command (J) = '/'                 or else
 521                Current_Command (J) = Directory_Separator or else
 522                Current_Command (J) = ':'
 523             then
 524                Start_Of_Prefix := J + 1;
 525                exit;
 526             end if;
 527          end loop;
 528
 529          --  Find End_Of_Prefix
 530
 531          for J in Start_Of_Prefix ..
 532                   Current_Command'Last - Gnatchop_Str'Length + 1
 533          loop
 534             if Current_Command (J .. J + Gnatchop_Str'Length - 1) =
 535                                                                   Gnatchop_Str
 536             then
 537                End_Of_Prefix := J - 1;
 538                exit;
 539             end if;
 540          end loop;
 541       end if;
 542
 543       if End_Of_Prefix > Current_Command'First then
 544          Start_Of_Suffix := End_Of_Prefix + Gnatchop_Str'Length + 1;
 545       end if;
 546
 547       declare
 548          Command : constant String :=
 549                      Current_Command (Start_Of_Prefix .. End_Of_Prefix)
 550                        & Program_Name
 551                        & Current_Command (Start_Of_Suffix ..
 552                                           Current_Command'Last);
 553       begin
 554          Result := Locate_Exec_On_Path (Command);
 555
 556          if Result = null then
 557             Error_Msg
 558               (Command & ": installation problem, executable not found");
 559          end if;
 560       end;
 561
 562       return Result;
 563    end Locate_Executable;
 564
 565    ---------------
 566    -- Parse_EOL --
 567    ---------------
 568
 569    procedure Parse_EOL
 570      (Source : not null access String;
 571       Ptr    : in out Positive) is
 572    begin
 573       --  Skip to end of line
 574
 575       while Source (Ptr) /= ASCII.CR and then Source (Ptr) /= ASCII.LF
 576         and then Source (Ptr) /= EOF
 577       loop
 578          Ptr := Ptr + 1;
 579       end loop;
 580
 581       if Source (Ptr) /= EOF then
 582          Ptr := Ptr + 1;      -- skip CR or LF
 583       end if;
 584
 585       --  Skip past CR/LF or LF/CR combination
 586
 587       if (Source (Ptr) = ASCII.CR or else Source (Ptr) = ASCII.LF)
 588          and then Source (Ptr) /= Source (Ptr - 1)
 589       then
 590          Ptr := Ptr + 1;
 591       end if;
 592    end Parse_EOL;
 593
 594    ----------------
 595    -- Parse_File --
 596    ----------------
 597
 598    function Parse_File (Num : File_Num) return Boolean is
 599       Chop_Name   : constant String_Access   := File.Table (Num).Name;
 600       Save_Stdout : constant File_Descriptor := dup (Standout);
 601       Offset_Name : Temp_File_Name;
 602       Offset_FD   : File_Descriptor := Invalid_FD;
 603       Buffer      : String_Access;
 604       Success     : Boolean;
 605       Failure     : exception;
 606
 607    begin
 608       --  Display copy of GNAT command if verbose mode
 609
 610       if Verbose_Mode then
 611          Put (Gnat_Cmd.all);
 612
 613          for J in 1 .. Gnat_Args'Length loop
 614             Put (' ');
 615             Put (Gnat_Args (J).all);
 616          end loop;
 617
 618          Put (' ');
 619          Put_Line (Chop_Name.all);
 620       end if;
 621
 622       --  Create temporary file
 623
 624       Create_Temp_File (Offset_FD, Offset_Name);
 625
 626       if Offset_FD = Invalid_FD then
 627          Error_Msg ("gnatchop: cannot create temporary file");
 628          Close (Save_Stdout);
 629          return False;
 630       end if;
 631
 632       --  Redirect Stdout to this temporary file in the Unix way
 633
 634       if dup2 (Offset_FD, Standout) = Invalid_FD then
 635          Error_Msg ("gnatchop: cannot redirect stdout to temporary file");
 636          Close (Save_Stdout);
 637          Close (Offset_FD);
 638          return False;
 639       end if;
 640
 641       --  Call Gnat on the source filename argument with special options
 642       --  to generate offset information. If this special compilation completes
 643       --  successfully then we can do the actual gnatchop operation.
 644
 645       Spawn (Gnat_Cmd.all, Gnat_Args.all & Chop_Name, Success);
 646
 647       if not Success then
 648          Error_Msg (Chop_Name.all & ": parse errors detected");
 649          Error_Msg (Chop_Name.all & ": chop may not be successful");
 650       end if;
 651
 652       --  Restore stdout
 653
 654       if dup2 (Save_Stdout, Standout) = Invalid_FD then
 655          Error_Msg ("gnatchop: cannot restore stdout");
 656       end if;
 657
 658       --  Reopen the file to start reading from the beginning
 659
 660       Close (Offset_FD);
 661       Close (Save_Stdout);
 662       Offset_FD := Open_Read (Offset_Name'Address, Binary);
 663
 664       if Offset_FD = Invalid_FD then
 665          Error_Msg ("gnatchop: cannot access offset info");
 666          raise Failure;
 667       end if;
 668
 669       Read_File (Offset_FD, Buffer, Success);
 670
 671       if not Success then
 672          Error_Msg ("gnatchop: error reading offset info");
 673          Close (Offset_FD);
 674          raise Failure;
 675       else
 676          Parse_Offset_Info (Num, Buffer);
 677       end if;
 678
 679       --  Close and delete temporary file
 680
 681       Close (Offset_FD);
 682       Delete_File (Offset_Name'Address, Success);
 683
 684       return Success;
 685
 686    exception
 687       when Failure | Types.Terminate_Program =>
 688          if Offset_FD /= Invalid_FD then
 689             Close (Offset_FD);
 690          end if;
 691
 692          Delete_File (Offset_Name'Address, Success);
 693          return False;
 694    end Parse_File;
 695
 696    -----------------------
 697    -- Parse_Offset_Info --
 698    -----------------------
 699
 700    procedure Parse_Offset_Info
 701      (Chop_File : File_Num;
 702       Source    : not null access String)
 703    is
 704       First_Unit : constant Unit_Num := Unit.Last + 1;
 705       Bufferg    : String_Access     := null;
 706       Parse_Ptr  : File_Offset       := Source'First;
 707       Token_Ptr  : File_Offset;
 708       Info       : Unit_Info;
 709
 710       function Match (Literal : String) return Boolean;
 711       --  Checks if given string appears at the current Token_Ptr location
 712       --  and if so, bumps Parse_Ptr past the token and returns True. If
 713       --  the string is not present, sets Parse_Ptr to Token_Ptr and
 714       --  returns False.
 715
 716       -----------
 717       -- Match --
 718       -----------
 719
 720       function Match (Literal : String) return Boolean is
 721       begin
 722          Parse_Token (Source, Parse_Ptr, Token_Ptr);
 723
 724          if Source'Last  + 1 - Token_Ptr < Literal'Length
 725            or else
 726              Source (Token_Ptr .. Token_Ptr + Literal'Length - 1) /= Literal
 727          then
 728             Parse_Ptr := Token_Ptr;
 729             return False;
 730          end if;
 731
 732          Parse_Ptr := Token_Ptr + Literal'Length;
 733          return True;
 734       end Match;
 735
 736    --  Start of processing for Parse_Offset_Info
 737
 738    begin
 739       loop
 740          --  Set default values, should get changed for all
 741          --  units/pragmas except for the last
 742
 743          Info.Chop_File := Chop_File;
 744          Info.Length := 0;
 745
 746          --  Parse the current line of offset information into Info
 747          --  and exit the loop if there are any errors or on EOF.
 748
 749          --  First case, parse a line in the following format:
 750
 751          --  Unit x (spec) line 7, file offset 142, [SR, ]file name x.ads
 752
 753          --  Note that the unit name can be an operator name in quotes.
 754          --  This is of course illegal, but both GNAT and gnatchop handle
 755          --  the case so that this error does not interfere with chopping.
 756
 757          --  The SR ir present indicates that a source reference pragma
 758          --  was processed as part of this unit (and that therefore no
 759          --  Source_Reference pragma should be generated.
 760
 761          if Match ("Unit") then
 762             Parse_Token (Source, Parse_Ptr, Token_Ptr);
 763
 764             if Match ("(body)") then
 765                Info.Kind := Unit_Body;
 766             elsif Match ("(spec)") then
 767                Info.Kind := Unit_Spec;
 768             else
 769                exit;
 770             end if;
 771
 772             exit when not Match ("line");
 773             Parse_Token (Source, Parse_Ptr, Token_Ptr);
 774             Info.Start_Line := Line_Num'Value
 775               (Source (Token_Ptr .. Parse_Ptr - 1));
 776
 777             exit when not Match ("file offset");
 778             Parse_Token (Source, Parse_Ptr, Token_Ptr);
 779             Info.Offset := File_Offset'Value
 780               (Source (Token_Ptr .. Parse_Ptr - 1));
 781
 782             Info.SR_Present := Match ("SR, ");
 783
 784             exit when not Match ("file name");
 785             Parse_Token (Source, Parse_Ptr, Token_Ptr);
 786             Info.File_Name := new String'
 787               (Directory.all & Source (Token_Ptr .. Parse_Ptr - 1));
 788             Parse_EOL (Source, Parse_Ptr);
 789
 790          --  Second case, parse a line of the following form
 791
 792          --  Configuration pragmas at line 10, file offset 223
 793
 794          elsif Match ("Configuration pragmas at") then
 795             Info.Kind := Config_Pragmas;
 796             Info.File_Name := Config_File_Name;
 797
 798             exit when not Match ("line");
 799             Parse_Token (Source, Parse_Ptr, Token_Ptr);
 800             Info.Start_Line := Line_Num'Value
 801               (Source (Token_Ptr .. Parse_Ptr - 1));
 802
 803             exit when not Match ("file offset");
 804             Parse_Token (Source, Parse_Ptr, Token_Ptr);
 805             Info.Offset := File_Offset'Value
 806               (Source (Token_Ptr .. Parse_Ptr - 1));
 807
 808             Parse_EOL (Source, Parse_Ptr);
 809
 810          --  Third case, parse a line of the following form
 811
 812          --    Source_Reference pragma for file "filename"
 813
 814          --  This appears at the start of the file only, and indicates
 815          --  the name to be used on any generated Source_Reference pragmas.
 816
 817          elsif Match ("Source_Reference pragma for file ") then
 818             Parse_Token (Source, Parse_Ptr, Token_Ptr);
 819             File.Table (Chop_File).SR_Name :=
 820               new String'(Source (Token_Ptr + 1 .. Parse_Ptr - 2));
 821             Parse_EOL (Source, Parse_Ptr);
 822             goto Continue;
 823
 824          --  Unrecognized keyword or end of file
 825
 826          else
 827             exit;
 828          end if;
 829
 830          --  Store the data in the Info record in the Unit.Table
 831
 832          Unit.Increment_Last;
 833          Unit.Table (Unit.Last) := Info;
 834
 835          --  If this is not the first unit from the file, calculate
 836          --  the length of the previous unit as difference of the offsets
 837
 838          if Unit.Last > First_Unit then
 839             Unit.Table (Unit.Last - 1).Length :=
 840               Info.Offset - Unit.Table (Unit.Last - 1).Offset;
 841          end if;
 842
 843          --  If not in compilation mode combine current unit with any
 844          --  preceding configuration pragmas.
 845
 846          if not Compilation_Mode
 847            and then Unit.Last > First_Unit
 848            and then Unit.Table (Unit.Last - 1).Kind = Config_Pragmas
 849          then
 850             Info.Start_Line := Unit.Table (Unit.Last - 1).Start_Line;
 851             Info.Offset := Unit.Table (Unit.Last - 1).Offset;
 852
 853             --  Delete the configuration pragma entry
 854
 855             Unit.Table (Unit.Last - 1) := Info;
 856             Unit.Decrement_Last;
 857          end if;
 858
 859          --  If in compilation mode, and previous entry is the initial
 860          --  entry for the file and is for configuration pragmas, then
 861          --  they are to be appended to every unit in the file.
 862
 863          if Compilation_Mode
 864            and then Unit.Last = First_Unit + 1
 865            and then Unit.Table (First_Unit).Kind = Config_Pragmas
 866          then
 867             Bufferg :=
 868               Get_Config_Pragmas
 869                 (Unit.Table (Unit.Last - 1).Chop_File, First_Unit);
 870             Unit.Table (Unit.Last - 1) := Info;
 871             Unit.Decrement_Last;
 872          end if;
 873
 874          Unit.Table (Unit.Last).Bufferg := Bufferg;
 875
 876          --  If in compilation mode, and this is not the first item,
 877          --  combine configuration pragmas with previous unit, which
 878          --  will cause an error message to be generated when the unit
 879          --  is compiled.
 880
 881          if Compilation_Mode
 882            and then Unit.Last > First_Unit
 883            and then Unit.Table (Unit.Last).Kind = Config_Pragmas
 884          then
 885             Unit.Decrement_Last;
 886          end if;
 887
 888       <<Continue>>
 889          null;
 890
 891       end loop;
 892
 893       --  Find out if the loop was exited prematurely because of
 894       --  an error or if the EOF marker was found.
 895
 896       if Source (Parse_Ptr) /= EOF then
 897          Error_Msg
 898            (File.Table (Chop_File).Name.all & ": error parsing offset info");
 899          return;
 900       end if;
 901
 902       --  Handle case of a chop file consisting only of config pragmas
 903
 904       if Unit.Last = First_Unit
 905         and then Unit.Table (Unit.Last).Kind = Config_Pragmas
 906       then
 907          --  In compilation mode, we append such a file to gnat.adc
 908
 909          if Compilation_Mode then
 910             Write_Config_File (Unit.Table (Unit.Last).Chop_File, First_Unit);
 911             Unit.Decrement_Last;
 912
 913          --  In default (non-compilation) mode, this is invalid
 914
 915          else
 916             Error_Msg
 917               (File.Table (Chop_File).Name.all &
 918                ": no units found (only pragmas)");
 919             Unit.Decrement_Last;
 920          end if;
 921       end if;
 922
 923       --  Handle case of a chop file ending with config pragmas. This can
 924       --  happen only in default non-compilation mode, since in compilation
 925       --  mode such configuration pragmas are part of the preceding unit.
 926       --  We simply concatenate such pragmas to the previous file which
 927       --  will cause a compilation error, which is appropriate.
 928
 929       if Unit.Last > First_Unit
 930         and then Unit.Table (Unit.Last).Kind = Config_Pragmas
 931       then
 932          Unit.Decrement_Last;
 933       end if;
 934    end Parse_Offset_Info;
 935
 936    -----------------
 937    -- Parse_Token --
 938    -----------------
 939
 940    procedure Parse_Token
 941      (Source    : not null access String;
 942       Ptr       : in out Positive;
 943       Token_Ptr : out Positive)
 944    is
 945       In_Quotes : Boolean := False;
 946
 947    begin
 948       --  Skip separators
 949
 950       while Source (Ptr) = ' ' or else Source (Ptr) = ',' loop
 951          Ptr := Ptr + 1;
 952       end loop;
 953
 954       Token_Ptr := Ptr;
 955
 956       --  Find end-of-token
 957
 958       while (In_Quotes
 959               or else not (Source (Ptr) = ' ' or else Source (Ptr) = ','))
 960         and then Source (Ptr) >= ' '
 961       loop
 962          if Source (Ptr) = '"' then
 963             In_Quotes := not In_Quotes;
 964          end if;
 965
 966          Ptr := Ptr + 1;
 967       end loop;
 968    end Parse_Token;
 969
 970    ---------------
 971    -- Read_File --
 972    ---------------
 973
 974    procedure Read_File
 975      (FD       : File_Descriptor;
 976       Contents : out String_Access;
 977       Success  : out Boolean)
 978    is
 979       Length      : constant File_Offset := File_Offset (File_Length (FD));
 980       --  Include room for EOF char
 981       Buffer      : String_Access := new String (1 .. Length + 1);
 982
 983       This_Read   : Integer;
 984       Read_Ptr    : File_Offset := 1;
 985
 986    begin
 987
 988       loop
 989          This_Read := Read (FD,
 990            A => Buffer (Read_Ptr)'Address,
 991            N => Length + 1 - Read_Ptr);
 992          Read_Ptr := Read_Ptr + Integer'Max (This_Read, 0);
 993          exit when This_Read <= 0;
 994       end loop;
 995
 996       Buffer (Read_Ptr) := EOF;
 997
 998       --  Comment needed for the following ???
 999       --  Under what circumstances can the test fail ???
1000       --  What is copy doing in that case???
1001
1002       if Read_Ptr = Length then
1003          Contents := Buffer;
1004
1005       else
1006          Contents := new String (1 .. Read_Ptr);
1007          Contents.all := Buffer (1 .. Read_Ptr);
1008          Free (Buffer);
1009       end if;
1010
1011       Success := Read_Ptr = Length + 1;
1012    end Read_File;
1013
1014    ----------------------------
1015    -- Report_Duplicate_Units --
1016    ----------------------------
1017
1018    function Report_Duplicate_Units return Boolean is
1019       US : SUnit_Num;
1020       U  : Unit_Num;
1021
1022       Duplicates : Boolean  := False;
1023
1024    begin
1025       US := 1;
1026       while US < SUnit_Num (Unit.Last) loop
1027          U := Sorted_Units.Table (US);
1028
1029          if Is_Duplicated (US) then
1030             Duplicates := True;
1031
1032             --  Move to last two versions of duplicated file to make it clearer
1033             --  to understand which file is retained in case of overwriting.
1034
1035             while US + 1 < SUnit_Num (Unit.Last) loop
1036                exit when not Is_Duplicated (US + 1);
1037                US := US + 1;
1038             end loop;
1039
1040             U := Sorted_Units.Table (US);
1041
1042             if Overwrite_Files then
1043                Warning_Msg (Unit.Table (U).File_Name.all
1044                  & " is duplicated (all but last will be skipped)");
1045
1046             elsif Unit.Table (U).Chop_File =
1047                     Unit.Table (Sorted_Units.Table (US + 1)).Chop_File
1048             then
1049                Error_Msg (Unit.Table (U).File_Name.all
1050                  & " is duplicated in "
1051                  & File.Table (Unit.Table (U).Chop_File).Name.all);
1052
1053             else
1054                Error_Msg (Unit.Table (U).File_Name.all
1055                   & " in "
1056                   & File.Table (Unit.Table (U).Chop_File).Name.all
1057                   & " is duplicated in "
1058                   & File.Table
1059                       (Unit.Table
1060                         (Sorted_Units.Table (US + 1)).Chop_File).Name.all);
1061             end if;
1062          end if;
1063
1064          US := US + 1;
1065       end loop;
1066
1067       if Duplicates and not Overwrite_Files then
1068          Put_Line ("use -w to overwrite files and keep last version");
1069       end if;
1070
1071       return Duplicates;
1072    end Report_Duplicate_Units;
1073
1074    --------------------
1075    -- Scan_Arguments --
1076    --------------------
1077
1078    function Scan_Arguments return Boolean is
1079       Kset : Boolean := False;
1080       --  Set true if -k switch found
1081
1082    begin
1083       Initialize_Option_Scan;
1084
1085       --  Scan options first
1086
1087       loop
1088          case Getopt ("c gnat? h k? p q r v w x -GCC=!") is
1089             when ASCII.NUL =>
1090                exit;
1091
1092             when '-' =>
1093                Gcc     := new String'(Parameter);
1094                Gcc_Set := True;
1095
1096             when 'c' =>
1097                Compilation_Mode := True;
1098
1099             when 'g' =>
1100                Gnat_Args :=
1101                  new Argument_List'(Gnat_Args.all &
1102                                       new String'("-gnat" & Parameter));
1103
1104             when 'h' =>
1105                Usage;
1106                raise Types.Terminate_Program;
1107
1108             when 'k' =>
1109                declare
1110                   Param : String_Access := new String'(Parameter);
1111
1112                begin
1113                   if Param.all /= "" then
1114                      for J in Param'Range loop
1115                         if Param (J) not in '0' .. '9' then
1116                            Error_Msg ("-k# requires numeric parameter");
1117                            return False;
1118                         end if;
1119                      end loop;
1120
1121                   else
1122                      Param := new String'("8");
1123                   end if;
1124
1125                   Gnat_Args :=
1126                     new Argument_List'(Gnat_Args.all &
1127                                          new String'("-gnatk" & Param.all));
1128                   Kset := True;
1129                end;
1130
1131             when 'p' =>
1132                Preserve_Mode := True;
1133
1134             when 'q' =>
1135                Quiet_Mode := True;
1136
1137             when 'r' =>
1138                Source_References := True;
1139
1140             when 'v' =>
1141                Verbose_Mode := True;
1142                Display_Version ("GNATCHOP", "1998");
1143
1144             when 'w' =>
1145                Overwrite_Files := True;
1146
1147             when 'x' =>
1148                Exit_On_Error := True;
1149
1150             when others =>
1151                null;
1152          end case;
1153       end loop;
1154
1155       if not Kset and then Maximum_File_Name_Length > 0 then
1156
1157          --  If this system has restricted filename lengths, tell gnat1
1158          --  about them, removing the leading blank from the image string.
1159
1160          Gnat_Args :=
1161            new Argument_List'(Gnat_Args.all
1162              & new String'("-gnatk"
1163                & Maximum_File_Name_Length_String
1164                  (Maximum_File_Name_Length_String'First + 1
1165                   .. Maximum_File_Name_Length_String'Last)));
1166       end if;
1167
1168       --  Scan file names
1169
1170       loop
1171          declare
1172             S : constant String := Get_Argument (Do_Expansion => True);
1173
1174          begin
1175             exit when S = "";
1176             File.Increment_Last;
1177             File.Table (File.Last).Name    := new String'(S);
1178             File.Table (File.Last).SR_Name := null;
1179          end;
1180       end loop;
1181
1182       --  Case of more than one file where last file is a directory
1183
1184       if File.Last > 1
1185         and then Is_Directory (File.Table (File.Last).Name.all)
1186       then
1187          Directory := File.Table (File.Last).Name;
1188          File.Decrement_Last;
1189
1190          --  Make sure Directory is terminated with a directory separator,
1191          --  so we can generate the output by just appending a filename.
1192
1193          if Directory (Directory'Last) /= Directory_Separator
1194             and then Directory (Directory'Last) /= '/'
1195          then
1196             Directory := new String'(Directory.all & Directory_Separator);
1197          end if;
1198
1199       --  At least one filename must be given
1200
1201       elsif File.Last = 0 then
1202          if Argument_Count = 0 then
1203             Usage;
1204          else
1205             Try_Help;
1206          end if;
1207
1208          return False;
1209
1210       --  No directory given, set directory to null, so that we can just
1211       --  concatenate the directory name to the file name unconditionally.
1212
1213       else
1214          Directory := new String'("");
1215       end if;
1216
1217       --  Finally check all filename arguments
1218
1219       for File_Num in 1 .. File.Last loop
1220          declare
1221             F : constant String := File.Table (File_Num).Name.all;
1222
1223          begin
1224             if Is_Directory (F) then
1225                Error_Msg (F & " is a directory, cannot be chopped");
1226                return False;
1227
1228             elsif not Is_Regular_File (F) then
1229                Error_Msg (F & " not found");
1230                return False;
1231             end if;
1232          end;
1233       end loop;
1234
1235       return True;
1236
1237    exception
1238       when Invalid_Switch =>
1239          Error_Msg ("invalid switch " & Full_Switch);
1240          return False;
1241
1242       when Invalid_Parameter =>
1243          Error_Msg ("-k switch requires numeric parameter");
1244          return False;
1245    end Scan_Arguments;
1246
1247    ----------------
1248    -- Sort_Units --
1249    ----------------
1250
1251    procedure Sort_Units is
1252
1253       procedure Move (From : Natural; To : Natural);
1254       --  Procedure used to sort the unit list
1255       --  Unit.Table (To) := Unit_List (From); used by sort
1256
1257       function Lt (Left, Right : Natural) return Boolean;
1258       --  Compares Left and Right units based on file name (first),
1259       --  Chop_File (second) and Offset (third). This ordering is
1260       --  important to keep the last version in case of duplicate files.
1261
1262       package Unit_Sort is new GNAT.Heap_Sort_G (Move, Lt);
1263       --  Used for sorting on filename to detect duplicates
1264
1265       --------
1266       -- Lt --
1267       --------
1268
1269       function Lt (Left, Right : Natural) return Boolean is
1270          L : Unit_Info renames
1271                Unit.Table (Sorted_Units.Table (SUnit_Num (Left)));
1272
1273          R : Unit_Info renames
1274                Unit.Table (Sorted_Units.Table (SUnit_Num (Right)));
1275
1276       begin
1277          return L.File_Name.all < R.File_Name.all
1278            or else (L.File_Name.all = R.File_Name.all
1279                      and then (L.Chop_File < R.Chop_File
1280                                  or else (L.Chop_File = R.Chop_File
1281                                             and then L.Offset < R.Offset)));
1282       end Lt;
1283
1284       ----------
1285       -- Move --
1286       ----------
1287
1288       procedure Move (From : Natural; To : Natural) is
1289       begin
1290          Sorted_Units.Table (SUnit_Num (To)) :=
1291            Sorted_Units.Table (SUnit_Num (From));
1292       end Move;
1293
1294    --  Start of processing for Sort_Units
1295
1296    begin
1297       Sorted_Units.Set_Last (SUnit_Num (Unit.Last));
1298
1299       for J in 1 .. Unit.Last loop
1300          Sorted_Units.Table (SUnit_Num (J)) := J;
1301       end loop;
1302
1303       --  Sort Unit.Table, using Sorted_Units.Table (0) as scratch
1304
1305       Unit_Sort.Sort (Natural (Unit.Last));
1306
1307       --  Set the Sorted_Index fields in the unit tables
1308
1309       for J in 1 .. SUnit_Num (Unit.Last) loop
1310          Unit.Table (Sorted_Units.Table (J)).Sorted_Index := J;
1311       end loop;
1312    end Sort_Units;
1313
1314    -----------
1315    -- Usage --
1316    -----------
1317
1318    procedure Usage is
1319    begin
1320       Put_Line
1321         ("Usage: gnatchop [-c] [-h] [-k#] " &
1322          "[-r] [-p] [-q] [-v] [-w] [-x] [--GCC=xx] file [file ...] [dir]");
1323
1324       New_Line;
1325
1326       Display_Usage_Version_And_Help;
1327
1328       Put_Line
1329         ("  -c       compilation mode, configuration pragmas " &
1330          "follow RM rules");
1331
1332       Put_Line
1333         ("  -gnatxxx passes the -gnatxxx switch to gnat parser");
1334
1335       Put_Line
1336         ("  -h       help: output this usage information");
1337
1338       Put_Line
1339         ("  -k#      krunch file names of generated files to " &
1340          "no more than # characters");
1341
1342       Put_Line
1343         ("  -k       krunch file names of generated files to " &
1344          "no more than 8 characters");
1345
1346       Put_Line
1347         ("  -p       preserve time stamp, output files will " &
1348          "have same stamp as input");
1349
1350       Put_Line
1351         ("  -q       quiet mode, no output of generated file " &
1352          "names");
1353
1354       Put_Line
1355         ("  -r       generate Source_Reference pragmas refer" &
1356          "encing original source file");
1357
1358       Put_Line
1359         ("  -v       verbose mode, output version and generat" &
1360          "ed commands");
1361
1362       Put_Line
1363         ("  -w       overwrite existing filenames");
1364
1365       Put_Line
1366         ("  -x       exit on error");
1367
1368       Put_Line
1369         ("  --GCC=xx specify the path of the gnat parser to be used");
1370
1371       New_Line;
1372       Put_Line
1373         ("  file...  list of source files to be chopped");
1374
1375       Put_Line
1376         ("  dir      directory location for split files (defa" &
1377          "ult = current directory)");
1378    end Usage;
1379
1380    -----------------
1381    -- Warning_Msg --
1382    -----------------
1383
1384    procedure Warning_Msg (Message : String) is
1385    begin
1386       Warning_Count := Warning_Count + 1;
1387       Put_Line (Standard_Error, "warning: " & Message);
1388    end Warning_Msg;
1389
1390    -------------------------
1391    -- Write_Chopped_Files --
1392    -------------------------
1393
1394    function Write_Chopped_Files (Input : File_Num) return Boolean is
1395       Name    : aliased constant String :=
1396                   File.Table (Input).Name.all & ASCII.NUL;
1397       FD      : File_Descriptor;
1398       Buffer  : String_Access;
1399       Success : Boolean;
1400       TS_Time : OS_Time;
1401
1402       BOM_Present : Boolean;
1403       BOM         : BOM_Kind;
1404       --  Record presence of UTF8 BOM in input
1405
1406    begin
1407       FD := Open_Read (Name'Address, Binary);
1408       TS_Time := File_Time_Stamp (FD);
1409
1410       if FD = Invalid_FD then
1411          Error_Msg ("cannot open " & File.Table (Input).Name.all);
1412          return False;
1413       end if;
1414
1415       Read_File (FD, Buffer, Success);
1416
1417       if not Success then
1418          Error_Msg ("cannot read " & File.Table (Input).Name.all);
1419          Close (FD);
1420          return False;
1421       end if;
1422
1423       if not Quiet_Mode then
1424          Put_Line ("splitting " & File.Table (Input).Name.all & " into:");
1425       end if;
1426
1427       --  Test for presence of BOM
1428
1429       Read_BOM (Buffer.all, BOM_Length, BOM, XML_Support => False);
1430       BOM_Present := BOM /= Unknown;
1431
1432       --  Only chop those units that come from this file
1433
1434       for Unit_Number in 1 .. Unit.Last loop
1435          if Unit.Table (Unit_Number).Chop_File = Input then
1436             Write_Unit
1437               (Source    => Buffer,
1438                Num       => Unit_Number,
1439                TS_Time   => TS_Time,
1440                Write_BOM => BOM_Present and then Unit_Number /= 1,
1441                Success   => Success);
1442             exit when not Success;
1443          end if;
1444       end loop;
1445
1446       Close (FD);
1447       return Success;
1448    end Write_Chopped_Files;
1449
1450    -----------------------
1451    -- Write_Config_File --
1452    -----------------------
1453
1454    procedure Write_Config_File (Input : File_Num; U : Unit_Num) is
1455       FD      : File_Descriptor;
1456       Name    : aliased constant String := "gnat.adc" & ASCII.NUL;
1457       Buffer  : String_Access;
1458       Success : Boolean;
1459       Append  : Boolean;
1460       Buffera : String_Access;
1461       Bufferl : Natural;
1462
1463    begin
1464       Write_gnat_adc := True;
1465       FD := Open_Read_Write (Name'Address, Binary);
1466
1467       if FD = Invalid_FD then
1468          FD := Create_File (Name'Address, Binary);
1469          Append := False;
1470
1471          if not Quiet_Mode then
1472             Put_Line ("writing configuration pragmas from " &
1473                File.Table (Input).Name.all & " to gnat.adc");
1474          end if;
1475
1476       else
1477          Append := True;
1478
1479          if not Quiet_Mode then
1480             Put_Line
1481               ("appending configuration pragmas from " &
1482                File.Table (Input).Name.all & " to gnat.adc");
1483          end if;
1484       end if;
1485
1486       Success := FD /= Invalid_FD;
1487
1488       if not Success then
1489          Error_Msg ("cannot create gnat.adc");
1490          return;
1491       end if;
1492
1493       --  In append mode, acquire existing gnat.adc file
1494
1495       if Append then
1496          Read_File (FD, Buffera, Success);
1497
1498          if not Success then
1499             Error_Msg ("cannot read gnat.adc");
1500             return;
1501          end if;
1502
1503          --  Find location of EOF byte if any to exclude from append
1504
1505          Bufferl := 1;
1506          while Bufferl <= Buffera'Last
1507            and then Buffera (Bufferl) /= EOF
1508          loop
1509             Bufferl := Bufferl + 1;
1510          end loop;
1511
1512          Bufferl := Bufferl - 1;
1513          Close (FD);
1514
1515          --  Write existing gnat.adc to new gnat.adc file
1516
1517          FD := Create_File (Name'Address, Binary);
1518          Success := Write (FD, Buffera (1)'Address, Bufferl) = Bufferl;
1519
1520          if not Success then
1521             Error_Msg ("error writing gnat.adc");
1522             return;
1523          end if;
1524       end if;
1525
1526       Buffer := Get_Config_Pragmas  (Input, U);
1527
1528       if Buffer /= null then
1529          Success := Write (FD, Buffer.all'Address, Buffer'Length) =
1530                                  Buffer'Length;
1531
1532          if not Success then
1533             Error_Msg ("disk full writing gnat.adc");
1534             return;
1535          end if;
1536       end if;
1537
1538       Close (FD);
1539    end Write_Config_File;
1540
1541    -----------------------------------
1542    -- Write_Source_Reference_Pragma --
1543    -----------------------------------
1544
1545    procedure Write_Source_Reference_Pragma
1546      (Info    : Unit_Info;
1547       Line    : Line_Num;
1548       File    : Stream_IO.File_Type;
1549       EOL     : EOL_String;
1550       Success : in out Boolean)
1551    is
1552       FTE : File_Entry renames Gnatchop.File.Table (Info.Chop_File);
1553       Nam : String_Access;
1554
1555    begin
1556       if Success and then Source_References and then not Info.SR_Present then
1557          if FTE.SR_Name /= null then
1558             Nam := FTE.SR_Name;
1559          else
1560             Nam := FTE.Name;
1561          end if;
1562
1563          declare
1564             Reference : String :=
1565                           "pragma Source_Reference (000000, """
1566                             & Nam.all & """);" & EOL.Str;
1567
1568             Pos : Positive := Reference'First;
1569             Lin : Line_Num := Line;
1570
1571          begin
1572             while Reference (Pos + 1) /= ',' loop
1573                Pos := Pos + 1;
1574             end loop;
1575
1576             while Reference (Pos) = '0' loop
1577                Reference (Pos) := Character'Val
1578                  (Character'Pos ('0') + Lin mod 10);
1579                Lin := Lin / 10;
1580                Pos := Pos - 1;
1581             end loop;
1582
1583             --  Assume there are enough zeroes for any program length
1584
1585             pragma Assert (Lin = 0);
1586
1587             begin
1588                String'Write (Stream_IO.Stream (File), Reference);
1589                Success := True;
1590             exception
1591                when others =>
1592                   Success := False;
1593             end;
1594          end;
1595       end if;
1596    end Write_Source_Reference_Pragma;
1597
1598    ----------------
1599    -- Write_Unit --
1600    ----------------
1601
1602    procedure Write_Unit
1603      (Source    : not null access String;
1604       Num       : Unit_Num;
1605       TS_Time   : OS_Time;
1606       Write_BOM : Boolean;
1607       Success   : out Boolean)
1608    is
1609
1610       procedure OS_Filename
1611         (Name     : String;
1612          W_Name   : Wide_String;
1613          OS_Name  : Address;
1614          N_Length : access Natural;
1615          Encoding : Address;
1616          E_Length : access Natural);
1617       pragma Import (C, OS_Filename, "__gnat_os_filename");
1618       --  Returns in OS_Name the proper name for the OS when used with the
1619       --  returned Encoding value. For example on Windows this will return the
1620       --  UTF-8 encoded name into OS_Name and set Encoding to encoding=utf8
1621       --  (the form parameter for Stream_IO).
1622       --
1623       --  Name is the filename and W_Name the same filename in Unicode 16 bits
1624       --  (this corresponds to Win32 Unicode ISO/IEC 10646). N_Length/E_Length
1625       --  are the length returned in OS_Name/Encoding respectively.
1626
1627       Info     : Unit_Info renames Unit.Table (Num);
1628       Name     : aliased constant String := Info.File_Name.all & ASCII.NUL;
1629       W_Name   : aliased constant Wide_String := To_Wide_String (Name);
1630       EOL      : constant EOL_String :=
1631                    Get_EOL (Source, Source'First + Info.Offset);
1632       OS_Name  : aliased String (1 .. Name'Length * 2);
1633       O_Length : aliased Natural := OS_Name'Length;
1634       Encoding : aliased String (1 .. 64);
1635       E_Length : aliased Natural := Encoding'Length;
1636       Length   : File_Offset;
1637
1638    begin
1639       --  Skip duplicated files
1640
1641       if Is_Duplicated (Info.Sorted_Index) then
1642          Put_Line ("   " & Info.File_Name.all & " skipped");
1643          Success := Overwrite_Files;
1644          return;
1645       end if;
1646
1647       --  Get OS filename
1648
1649       OS_Filename
1650         (Name, W_Name,
1651          OS_Name'Address, O_Length'Access,
1652          Encoding'Address, E_Length'Access);
1653
1654       declare
1655          E_Name      : constant String := OS_Name (1 .. O_Length);
1656          OS_Encoding : constant String := Encoding (1 .. E_Length);
1657          File        : Stream_IO.File_Type;
1658
1659       begin
1660          begin
1661             if not Overwrite_Files and then Exists (E_Name) then
1662                raise Stream_IO.Name_Error;
1663             else
1664                Stream_IO.Create
1665                  (File, Stream_IO.Out_File, E_Name, OS_Encoding);
1666                Success := True;
1667             end if;
1668
1669          exception
1670             when Stream_IO.Name_Error | Stream_IO.Use_Error =>
1671                Error_Msg ("cannot create " & Info.File_Name.all);
1672                return;
1673          end;
1674
1675          --  A length of 0 indicates that the rest of the file belongs to
1676          --  this unit. The actual length must be calculated now. Take into
1677          --  account that the last character (EOF) must not be written.
1678
1679          if Info.Length = 0 then
1680             Length := Source'Last - (Source'First + Info.Offset);
1681          else
1682             Length := Info.Length;
1683          end if;
1684
1685          --  Write BOM if required
1686
1687          if Write_BOM then
1688             String'Write
1689               (Stream_IO.Stream (File),
1690                Source.all (Source'First .. Source'First + BOM_Length - 1));
1691          end if;
1692
1693          --  Prepend configuration pragmas if necessary
1694
1695          if Success and then Info.Bufferg /= null then
1696             Write_Source_Reference_Pragma (Info, 1, File, EOL, Success);
1697             String'Write (Stream_IO.Stream (File), Info.Bufferg.all);
1698          end if;
1699
1700          Write_Source_Reference_Pragma
1701            (Info, Info.Start_Line, File, EOL, Success);
1702
1703          if Success then
1704             begin
1705                String'Write
1706                  (Stream_IO.Stream (File),
1707                   Source (Source'First + Info.Offset ..
1708                       Source'First + Info.Offset + Length - 1));
1709             exception
1710                when Stream_IO.Use_Error | Stream_IO.Device_Error =>
1711                   Error_Msg ("disk full writing " & Info.File_Name.all);
1712                   return;
1713             end;
1714          end if;
1715
1716          if not Quiet_Mode then
1717             Put_Line ("   " & Info.File_Name.all);
1718          end if;
1719
1720          Stream_IO.Close (File);
1721
1722          if Preserve_Mode then
1723             Set_File_Last_Modify_Time_Stamp (E_Name, TS_Time);
1724          end if;
1725       end;
1726    end Write_Unit;
1727
1728       procedure Check_Version_And_Help is new Check_Version_And_Help_G (Usage);
1729
1730 --  Start of processing for gnatchop
1731
1732 begin
1733    --  Add the directory where gnatchop is invoked in front of the path, if
1734    --  gnatchop is invoked with directory information.
1735
1736    declare
1737       Command : constant String := Command_Name;
1738
1739    begin
1740       for Index in reverse Command'Range loop
1741          if Command (Index) = Directory_Separator then
1742             declare
1743                Absolute_Dir : constant String :=
1744                                 Normalize_Pathname
1745                                   (Command (Command'First .. Index));
1746                PATH         : constant String :=
1747                                 Absolute_Dir
1748                                 & Path_Separator
1749                                 & Getenv ("PATH").all;
1750             begin
1751                Setenv ("PATH", PATH);
1752             end;
1753
1754             exit;
1755          end if;
1756       end loop;
1757    end;
1758
1759    --  Process command line options and initialize global variables
1760
1761    --  First, scan to detect --version and/or --help
1762
1763    Check_Version_And_Help ("GNATCHOP", "1998");
1764
1765    if not Scan_Arguments then
1766       Set_Exit_Status (Failure);
1767       return;
1768    end if;
1769
1770    --  Check presence of required executables
1771
1772    Gnat_Cmd := Locate_Executable (Gcc.all, not Gcc_Set);
1773
1774    if Gnat_Cmd = null then
1775       goto No_Files_Written;
1776    end if;
1777
1778    --  First parse all files and read offset information
1779
1780    for Num in 1 .. File.Last loop
1781       if not Parse_File (Num) then
1782          goto No_Files_Written;
1783       end if;
1784    end loop;
1785
1786    --  Check if any units have been found (assumes non-empty Unit.Table)
1787
1788    if Unit.Last = 0 then
1789       if not Write_gnat_adc then
1790          Error_Msg ("no compilation units found", Warning => True);
1791       end if;
1792
1793       goto No_Files_Written;
1794    end if;
1795
1796    Sort_Units;
1797
1798    --  Check if any duplicate files would be created. If so, emit a warning if
1799    --  Overwrite_Files is true, otherwise generate an error.
1800
1801    if Report_Duplicate_Units and then not Overwrite_Files then
1802       goto No_Files_Written;
1803    end if;
1804
1805    --  Check if any files exist, if so do not write anything Because all files
1806    --  have been parsed and checked already, there won't be any duplicates
1807
1808    if not Overwrite_Files and then Files_Exist then
1809       goto No_Files_Written;
1810    end if;
1811
1812    --  After this point, all source files are read in succession and chopped
1813    --  into their destination files.
1814
1815    --  Source_File_Name pragmas are handled as logical file 0 so write it first
1816
1817    for F in 1 .. File.Last loop
1818       if not Write_Chopped_Files (F) then
1819          Set_Exit_Status (Failure);
1820          return;
1821       end if;
1822    end loop;
1823
1824    if Warning_Count > 0 then
1825       declare
1826          Warnings_Msg : constant String := Warning_Count'Img & " warning(s)";
1827       begin
1828          Error_Msg (Warnings_Msg (2 .. Warnings_Msg'Last), Warning => True);
1829       end;
1830    end if;
1831
1832    return;
1833
1834 <<No_Files_Written>>
1835
1836    --  Special error exit for all situations where no files have
1837    --  been written.
1838
1839    if not Write_gnat_adc then
1840       Error_Msg ("no source files written", Warning => True);
1841    end if;
1842
1843    return;
1844
1845 exception
1846    when Types.Terminate_Program =>
1847       null;
1848
1849 end Gnatchop;