1 ------------------------------------------------------------------------------
3 -- GNAT RUN-TIME COMPONENTS --
5 -- A D A . T E X T _ I O --
9 -- Copyright (C) 1992-2009, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 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. --
18 -- As a special exception under Section 7 of GPL version 3, you are granted --
19 -- additional permissions described in the GCC Runtime Library Exception, --
20 -- version 3.1, as published by the Free Software Foundation. --
22 -- You should have received a copy of the GNU General Public License and --
23 -- a copy of the GCC Runtime Library Exception along with this program; --
24 -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
25 -- <http://www.gnu.org/licenses/>. --
27 -- GNAT was originally developed by the GNAT team at New York University. --
28 -- Extensive contributions were provided by Ada Core Technologies Inc. --
30 ------------------------------------------------------------------------------
32 with Ada.Streams; use Ada.Streams;
33 with Interfaces.C_Streams; use Interfaces.C_Streams;
37 with System.WCh_Cnv; use System.WCh_Cnv;
38 with System.WCh_Con; use System.WCh_Con;
40 with Ada.Unchecked_Conversion;
41 with Ada.Unchecked_Deallocation;
43 pragma Elaborate_All (System.File_IO);
44 -- Needed because of calls to Chain_File in package body elaboration
46 package body Ada.Text_IO is
48 package FIO renames System.File_IO;
50 subtype AP is FCB.AFCB_Ptr;
52 function To_FCB is new Ada.Unchecked_Conversion (File_Mode, FCB.File_Mode);
53 function To_TIO is new Ada.Unchecked_Conversion (FCB.File_Mode, File_Mode);
54 use type FCB.File_Mode;
56 use type System.CRTL.size_t;
58 WC_Encoding : Character;
59 pragma Import (C, WC_Encoding, "__gl_wc_encoding");
60 -- Default wide character encoding
62 Err_Name : aliased String := "*stderr" & ASCII.NUL;
63 In_Name : aliased String := "*stdin" & ASCII.NUL;
64 Out_Name : aliased String := "*stdout" & ASCII.NUL;
65 -- Names of standard files
67 -- Use "preallocated" strings to avoid calling "new" during the elaboration
68 -- of the run time. This is needed in the tasking case to avoid calling
69 -- Task_Lock too early. A filename is expected to end with a null character
70 -- in the runtime, here the null characters are added just to have a
71 -- correct filename length.
73 -- Note: the names for these files are bogus, and probably it would be
74 -- better for these files to have no names, but the ACVC tests insist!
75 -- We use names that are bound to fail in open etc.
77 Null_Str : aliased constant String := "";
78 -- Used as form string for standard files
80 -----------------------
81 -- Local Subprograms --
82 -----------------------
84 function Get_Upper_Half_Char
86 File : File_Type) return Character;
87 -- This function is shared by Get and Get_Immediate to extract an encoded
88 -- upper half character value from the given File. The first byte has
89 -- already been read and is passed in C. The character value is returned as
90 -- the result, and the file pointer is bumped past the character.
91 -- Constraint_Error is raised if the encoded value is outside the bounds of
94 function Get_Upper_Half_Char_Immed
96 File : File_Type) return Character;
97 -- This routine is identical to Get_Upper_Half_Char, except that the reads
98 -- are done in Get_Immediate mode (i.e. without waiting for a line return).
100 function Getc (File : File_Type) return int;
101 -- Gets next character from file, which has already been checked for being
102 -- in read status, and returns the character read if no error occurs. The
103 -- result is EOF if the end of file was read.
105 function Getc_Immed (File : File_Type) return int;
106 -- This routine is identical to Getc, except that the read is done in
107 -- Get_Immediate mode (i.e. without waiting for a line return).
109 function Has_Upper_Half_Character (Item : String) return Boolean;
110 -- Returns True if any of the characters is in the range 16#80#-16#FF#
112 function Nextc (File : File_Type) return int;
113 -- Returns next character from file without skipping past it (i.e. it is a
114 -- combination of Getc followed by an Ungetc).
116 procedure Put_Encoded (File : File_Type; Char : Character);
117 -- Called to output a character Char to the given File, when the encoding
118 -- method for the file is other than brackets, and Char is upper half.
120 procedure Putc (ch : int; File : File_Type);
121 -- Outputs the given character to the file, which has already been checked
122 -- for being in output status. Device_Error is raised if the character
123 -- cannot be written.
125 procedure Set_WCEM (File : in out File_Type);
126 -- Called by Open and Create to set the wide character encoding method for
127 -- the file, processing a WCEM form parameter if one is present. File is
128 -- IN OUT because it may be closed in case of an error.
130 procedure Terminate_Line (File : File_Type);
131 -- If the file is in Write_File or Append_File mode, and the current line
132 -- is not terminated, then a line terminator is written using New_Line.
133 -- Note that there is no Terminate_Page routine, because the page mark at
134 -- the end of the file is implied if necessary.
136 procedure Ungetc (ch : int; File : File_Type);
137 -- Pushes back character into stream, using ungetc. The caller has checked
138 -- that the file is in read status. Device_Error is raised if the character
139 -- cannot be pushed back. An attempt to push back and end of file character
146 function AFCB_Allocate (Control_Block : Text_AFCB) return FCB.AFCB_Ptr is
147 pragma Unreferenced (Control_Block);
149 return new Text_AFCB;
156 procedure AFCB_Close (File : not null access Text_AFCB) is
158 -- If the file being closed is one of the current files, then close
159 -- the corresponding current file. It is not clear that this action
160 -- is required (RM A.10.3(23)) but it seems reasonable, and besides
161 -- ACVC test CE3208A expects this behavior.
163 if File_Type (File) = Current_In then
165 elsif File_Type (File) = Current_Out then
167 elsif File_Type (File) = Current_Err then
171 Terminate_Line (File_Type (File));
178 procedure AFCB_Free (File : not null access Text_AFCB) is
179 type FCB_Ptr is access all Text_AFCB;
180 FT : FCB_Ptr := FCB_Ptr (File);
182 procedure Free is new Ada.Unchecked_Deallocation (Text_AFCB, FCB_Ptr);
192 procedure Close (File : in out File_Type) is
194 FIO.Close (AP (File)'Unrestricted_Access);
201 -- Note: we assume that it is impossible in practice for the column
202 -- to exceed the value of Count'Last, i.e. no check is required for
203 -- overflow raising layout error.
205 function Col (File : File_Type) return Positive_Count is
207 FIO.Check_File_Open (AP (File));
211 function Col return Positive_Count is
213 return Col (Current_Out);
221 (File : in out File_Type;
222 Mode : File_Mode := Out_File;
226 Dummy_File_Control_Block : Text_AFCB;
227 pragma Warnings (Off, Dummy_File_Control_Block);
228 -- Yes, we know this is never assigned a value, only the tag
229 -- is used for dispatching purposes, so that's expected.
232 FIO.Open (File_Ptr => AP (File),
233 Dummy_FCB => Dummy_File_Control_Block,
234 Mode => To_FCB (Mode),
249 function Current_Error return File_Type is
254 function Current_Error return File_Access is
256 return Current_Err.Self'Access;
263 function Current_Input return File_Type is
268 function Current_Input return File_Access is
270 return Current_In.Self'Access;
277 function Current_Output return File_Type is
282 function Current_Output return File_Access is
284 return Current_Out.Self'Access;
291 procedure Delete (File : in out File_Type) is
293 FIO.Delete (AP (File)'Unrestricted_Access);
300 function End_Of_File (File : File_Type) return Boolean is
304 FIO.Check_Read_Status (AP (File));
306 if File.Before_Upper_Half_Character then
309 elsif File.Before_LM then
310 if File.Before_LM_PM then
311 return Nextc (File) = EOF;
325 File.Before_LM := True;
329 -- Here we are just past the line mark with Before_LM set so that we
330 -- do not have to try to back up past the LM, thus avoiding the need
331 -- to back up more than one character.
338 elsif ch = PM and then File.Is_Regular_File then
339 File.Before_LM_PM := True;
340 return Nextc (File) = EOF;
342 -- Here if neither EOF nor PM followed end of line
351 function End_Of_File return Boolean is
353 return End_Of_File (Current_In);
360 function End_Of_Line (File : File_Type) return Boolean is
364 FIO.Check_Read_Status (AP (File));
366 if File.Before_Upper_Half_Character then
369 elsif File.Before_LM then
385 function End_Of_Line return Boolean is
387 return End_Of_Line (Current_In);
394 function End_Of_Page (File : File_Type) return Boolean is
398 FIO.Check_Read_Status (AP (File));
400 if not File.Is_Regular_File then
403 elsif File.Before_Upper_Half_Character then
406 elsif File.Before_LM then
407 if File.Before_LM_PM then
422 File.Before_LM := True;
426 -- Here we are just past the line mark with Before_LM set so that we
427 -- do not have to try to back up past the LM, thus avoiding the need
428 -- to back up more than one character.
432 return ch = PM or else ch = EOF;
435 function End_Of_Page return Boolean is
437 return End_Of_Page (Current_In);
444 function EOF_Char return Integer is
453 procedure Flush (File : File_Type) is
455 FIO.Flush (AP (File));
467 function Form (File : File_Type) return String is
469 return FIO.Form (AP (File));
478 Item : out Character)
483 FIO.Check_Read_Status (AP (File));
485 if File.Before_Upper_Half_Character then
486 File.Before_Upper_Half_Character := False;
487 Item := File.Saved_Upper_Half_Character;
489 elsif File.Before_LM then
490 File.Before_LM := False;
493 if File.Before_LM_PM then
495 File.Page := File.Page + 1;
496 File.Before_LM_PM := False;
498 File.Line := File.Line + 1;
509 File.Line := File.Line + 1;
512 elsif ch = PM and then File.Is_Regular_File then
513 File.Page := File.Page + 1;
517 Item := Character'Val (ch);
518 File.Col := File.Col + 1;
524 procedure Get (Item : out Character) is
526 Get (Current_In, Item);
537 FIO.Check_Read_Status (AP (File));
539 if File.Before_LM then
540 File.Before_LM := False;
541 File.Before_LM_PM := False;
544 if File.Before_LM_PM then
546 File.Page := File.Page + 1;
547 File.Before_LM_PM := False;
550 File.Line := File.Line + 1;
555 while J <= Item'Last loop
562 File.Line := File.Line + 1;
565 elsif ch = PM and then File.Is_Regular_File then
566 File.Page := File.Page + 1;
570 Item (J) := Character'Val (ch);
572 File.Col := File.Col + 1;
577 procedure Get (Item : out String) is
579 Get (Current_In, Item);
586 procedure Get_Immediate
588 Item : out Character)
593 FIO.Check_Read_Status (AP (File));
595 if File.Before_Upper_Half_Character then
596 File.Before_Upper_Half_Character := False;
597 Item := File.Saved_Upper_Half_Character;
599 elsif File.Before_LM then
600 File.Before_LM := False;
601 File.Before_LM_PM := False;
602 Item := Character'Val (LM);
605 ch := Getc_Immed (File);
611 (if not Is_Start_Of_Encoding (Character'Val (ch), File.WC_Method)
612 then Character'Val (ch)
613 else Get_Upper_Half_Char_Immed (Character'Val (ch), File));
618 procedure Get_Immediate
619 (Item : out Character)
622 Get_Immediate (Current_In, Item);
625 procedure Get_Immediate
627 Item : out Character;
628 Available : out Boolean)
634 procedure getc_immediate_nowait
637 end_of_file : out int;
639 pragma Import (C, getc_immediate_nowait, "getc_immediate_nowait");
642 FIO.Check_Read_Status (AP (File));
645 if File.Before_Upper_Half_Character then
646 File.Before_Upper_Half_Character := False;
647 Item := File.Saved_Upper_Half_Character;
649 elsif File.Before_LM then
650 File.Before_LM := False;
651 File.Before_LM_PM := False;
652 Item := Character'Val (LM);
655 getc_immediate_nowait (File.Stream, ch, end_of_file, avail);
657 if ferror (File.Stream) /= 0 then
660 elsif end_of_file /= 0 then
671 (if Is_Start_Of_Encoding (Character'Val (ch), File.WC_Method)
672 then Character'Val (ch)
673 else Get_Upper_Half_Char_Immed (Character'Val (ch), File));
679 procedure Get_Immediate
680 (Item : out Character;
681 Available : out Boolean)
684 Get_Immediate (Current_In, Item, Available);
699 FIO.Check_Read_Status (AP (File));
700 Last := Item'First - 1;
702 -- Immediate exit for null string, this is a case in which we do not
703 -- need to test for end of file and we do not skip a line mark under
704 -- any circumstances.
706 if Last >= Item'Last then
710 -- Here we have at least one character, if we are immediately before
711 -- a line mark, then we will just skip past it storing no characters.
713 if File.Before_LM then
714 File.Before_LM := False;
715 File.Before_LM_PM := False;
717 -- Otherwise we need to read some characters
722 -- If we are at the end of file now, it means we are trying to
723 -- skip a file terminator and we raise End_Error (RM A.10.7(20))
729 -- Loop through characters. Don't bother if we hit a page mark,
730 -- since in normal files, page marks can only follow line marks
731 -- in any case and we only promise to treat the page nonsense
732 -- correctly in the absense of such rogue page marks.
735 -- Exit the loop if read is terminated by encountering line mark
739 -- Otherwise store the character, note that we know that ch is
740 -- something other than LM or EOF. It could possibly be a page
741 -- mark if there is a stray page mark in the middle of a line,
742 -- but this is not an official page mark in any case, since
743 -- official page marks can only follow a line mark. The whole
744 -- page business is pretty much nonsense anyway, so we do not
745 -- want to waste time trying to make sense out of non-standard
746 -- page marks in the file! This means that the behavior of
747 -- Get_Line is different from repeated Get of a character, but
748 -- that's too bad. We only promise that page numbers etc make
749 -- sense if the file is formatted in a standard manner.
751 -- Note: we do not adjust the column number because it is quicker
752 -- to adjust it once at the end of the operation than incrementing
753 -- it each time around the loop.
756 Item (Last) := Character'Val (ch);
758 -- All done if the string is full, this is the case in which
759 -- we do not skip the following line mark. We need to adjust
760 -- the column number in this case.
762 if Last = Item'Last then
763 File.Col := File.Col + Count (Item'Length);
767 -- Otherwise read next character. We also exit from the loop if
768 -- we read an end of file. This is the case where the last line
769 -- is not terminated with a line mark, and we consider that there
770 -- is an implied line mark in this case (this is a non-standard
771 -- file, but it is nice to treat it reasonably).
778 -- We have skipped past, but not stored, a line mark. Skip following
779 -- page mark if one follows, but do not do this for a non-regular
780 -- file (since otherwise we get annoying wait for an extra character)
782 File.Line := File.Line + 1;
785 if File.Before_LM_PM then
787 File.Before_LM_PM := False;
788 File.Page := File.Page + 1;
790 elsif File.Is_Regular_File then
793 if ch = PM and then File.Is_Regular_File then
795 File.Page := File.Page + 1;
807 Get_Line (Current_In, Item, Last);
810 function Get_Line (File : File_Type) return String is
811 Buffer : String (1 .. 500);
814 function Get_Rest (S : String) return String;
815 -- This is a recursive function that reads the rest of the line and
816 -- returns it. S is the part read so far.
822 function Get_Rest (S : String) return String is
824 -- Each time we allocate a buffer the same size as what we have
825 -- read so far. This limits us to a logarithmic number of calls
826 -- to Get_Rest and also ensures only a linear use of stack space.
828 Buffer : String (1 .. S'Length);
832 Get_Line (File, Buffer, Last);
835 R : constant String := S & Buffer (1 .. Last);
837 if Last < Buffer'Last then
845 -- Start of processing for Get_Line
848 Get_Line (File, Buffer, Last);
850 if Last < Buffer'Last then
851 return Buffer (1 .. Last);
853 return Get_Rest (Buffer (1 .. Last));
857 function Get_Line return String is
859 return Get_Line (Current_In);
862 -------------------------
863 -- Get_Upper_Half_Char --
864 -------------------------
866 function Get_Upper_Half_Char
868 File : File_Type) return Character
870 Result : Wide_Character;
872 function In_Char return Character;
873 -- Function used to obtain additional characters it the wide character
874 -- sequence is more than one character long.
876 function WC_In is new Char_Sequence_To_Wide_Char (In_Char);
882 function In_Char return Character is
883 ch : constant Integer := Getc (File);
888 return Character'Val (ch);
892 -- Start of processing for Get_Upper_Half_Char
895 Result := WC_In (C, File.WC_Method);
897 if Wide_Character'Pos (Result) > 16#FF# then
898 raise Constraint_Error with
899 "invalid wide character in Text_'I'O input";
901 return Character'Val (Wide_Character'Pos (Result));
903 end Get_Upper_Half_Char;
905 -------------------------------
906 -- Get_Upper_Half_Char_Immed --
907 -------------------------------
909 function Get_Upper_Half_Char_Immed
911 File : File_Type) return Character
913 Result : Wide_Character;
915 function In_Char return Character;
916 -- Function used to obtain additional characters it the wide character
917 -- sequence is more than one character long.
919 function WC_In is new Char_Sequence_To_Wide_Char (In_Char);
925 function In_Char return Character is
926 ch : constant Integer := Getc_Immed (File);
931 return Character'Val (ch);
935 -- Start of processing for Get_Upper_Half_Char_Immed
938 Result := WC_In (C, File.WC_Method);
940 if Wide_Character'Pos (Result) > 16#FF# then
941 raise Constraint_Error with
942 "invalid wide character in Text_'I'O input";
944 return Character'Val (Wide_Character'Pos (Result));
946 end Get_Upper_Half_Char_Immed;
952 function Getc (File : File_Type) return int is
956 ch := fgetc (File.Stream);
958 if ch = EOF and then ferror (File.Stream) /= 0 then
969 function Getc_Immed (File : File_Type) return int is
973 procedure getc_immediate
974 (stream : FILEs; ch : out int; end_of_file : out int);
975 pragma Import (C, getc_immediate, "getc_immediate");
978 FIO.Check_Read_Status (AP (File));
980 if File.Before_LM then
981 File.Before_LM := False;
982 File.Before_LM_PM := False;
986 getc_immediate (File.Stream, ch, end_of_file);
988 if ferror (File.Stream) /= 0 then
990 elsif end_of_file /= 0 then
998 ------------------------------
999 -- Has_Upper_Half_Character --
1000 ------------------------------
1002 function Has_Upper_Half_Character (Item : String) return Boolean is
1004 for J in Item'Range loop
1005 if Character'Pos (Item (J)) >= 16#80# then
1011 end Has_Upper_Half_Character;
1013 -------------------------------
1014 -- Initialize_Standard_Files --
1015 -------------------------------
1017 procedure Initialize_Standard_Files is
1019 Standard_Err.Stream := stderr;
1020 Standard_Err.Name := Err_Name'Access;
1021 Standard_Err.Form := Null_Str'Unrestricted_Access;
1022 Standard_Err.Mode := FCB.Out_File;
1023 Standard_Err.Is_Regular_File := is_regular_file (fileno (stderr)) /= 0;
1024 Standard_Err.Is_Temporary_File := False;
1025 Standard_Err.Is_System_File := True;
1026 Standard_Err.Is_Text_File := True;
1027 Standard_Err.Access_Method := 'T';
1028 Standard_Err.Self := Standard_Err;
1029 Standard_Err.WC_Method := Default_WCEM;
1031 Standard_In.Stream := stdin;
1032 Standard_In.Name := In_Name'Access;
1033 Standard_In.Form := Null_Str'Unrestricted_Access;
1034 Standard_In.Mode := FCB.In_File;
1035 Standard_In.Is_Regular_File := is_regular_file (fileno (stdin)) /= 0;
1036 Standard_In.Is_Temporary_File := False;
1037 Standard_In.Is_System_File := True;
1038 Standard_In.Is_Text_File := True;
1039 Standard_In.Access_Method := 'T';
1040 Standard_In.Self := Standard_In;
1041 Standard_In.WC_Method := Default_WCEM;
1043 Standard_Out.Stream := stdout;
1044 Standard_Out.Name := Out_Name'Access;
1045 Standard_Out.Form := Null_Str'Unrestricted_Access;
1046 Standard_Out.Mode := FCB.Out_File;
1047 Standard_Out.Is_Regular_File := is_regular_file (fileno (stdout)) /= 0;
1048 Standard_Out.Is_Temporary_File := False;
1049 Standard_Out.Is_System_File := True;
1050 Standard_Out.Is_Text_File := True;
1051 Standard_Out.Access_Method := 'T';
1052 Standard_Out.Self := Standard_Out;
1053 Standard_Out.WC_Method := Default_WCEM;
1055 FIO.Make_Unbuffered (AP (Standard_Out));
1056 FIO.Make_Unbuffered (AP (Standard_Err));
1057 end Initialize_Standard_Files;
1063 function Is_Open (File : File_Type) return Boolean is
1065 return FIO.Is_Open (AP (File));
1072 -- Note: we assume that it is impossible in practice for the line
1073 -- to exceed the value of Count'Last, i.e. no check is required for
1074 -- overflow raising layout error.
1076 function Line (File : File_Type) return Positive_Count is
1078 FIO.Check_File_Open (AP (File));
1082 function Line return Positive_Count is
1084 return Line (Current_Out);
1091 function Line_Length (File : File_Type) return Count is
1093 FIO.Check_Write_Status (AP (File));
1094 return File.Line_Length;
1097 function Line_Length return Count is
1099 return Line_Length (Current_Out);
1106 procedure Look_Ahead
1108 Item : out Character;
1109 End_Of_Line : out Boolean)
1114 FIO.Check_Read_Status (AP (File));
1116 -- If we are logically before a line mark, we can return immediately
1118 if File.Before_LM then
1119 End_Of_Line := True;
1122 -- If we are before an upper half character just return it (this can
1123 -- happen if there are two calls to Look_Ahead in a row).
1125 elsif File.Before_Upper_Half_Character then
1126 End_Of_Line := False;
1127 Item := File.Saved_Upper_Half_Character;
1129 -- Otherwise we must read a character from the input stream
1136 or else (ch = PM and then File.Is_Regular_File)
1138 End_Of_Line := True;
1142 -- Case where character obtained does not represent the start of an
1143 -- encoded sequence so it stands for itself and we can unget it with
1146 elsif not Is_Start_Of_Encoding
1147 (Character'Val (ch), File.WC_Method)
1149 End_Of_Line := False;
1151 Item := Character'Val (ch);
1153 -- For the start of an encoding, we read the character using the
1154 -- Get_Upper_Half_Char routine. It will occupy more than one byte
1155 -- so we can't put it back with ungetc. Instead we save it in the
1156 -- control block, setting a flag that everyone interested in reading
1157 -- characters must test before reading the stream.
1160 Item := Get_Upper_Half_Char (Character'Val (ch), File);
1161 End_Of_Line := False;
1162 File.Saved_Upper_Half_Character := Item;
1163 File.Before_Upper_Half_Character := True;
1168 procedure Look_Ahead
1169 (Item : out Character;
1170 End_Of_Line : out Boolean)
1173 Look_Ahead (Current_In, Item, End_Of_Line);
1180 function Mode (File : File_Type) return File_Mode is
1182 return To_TIO (FIO.Mode (AP (File)));
1189 function Name (File : File_Type) return String is
1191 return FIO.Name (AP (File));
1200 Spacing : Positive_Count := 1)
1203 -- Raise Constraint_Error if out of range value. The reason for this
1204 -- explicit test is that we don't want junk values around, even if
1205 -- checks are off in the caller.
1207 if not Spacing'Valid then
1208 raise Constraint_Error;
1211 FIO.Check_Write_Status (AP (File));
1213 for K in 1 .. Spacing loop
1215 File.Line := File.Line + 1;
1217 if File.Page_Length /= 0
1218 and then File.Line > File.Page_Length
1222 File.Page := File.Page + 1;
1229 procedure New_Line (Spacing : Positive_Count := 1) is
1231 New_Line (Current_Out, Spacing);
1238 procedure New_Page (File : File_Type) is
1240 FIO.Check_Write_Status (AP (File));
1242 if File.Col /= 1 or else File.Line = 1 then
1247 File.Page := File.Page + 1;
1252 procedure New_Page is
1254 New_Page (Current_Out);
1261 function Nextc (File : File_Type) return int is
1265 ch := fgetc (File.Stream);
1268 if ferror (File.Stream) /= 0 then
1273 if ungetc (ch, File.Stream) = EOF then
1286 (File : in out File_Type;
1289 Form : String := "")
1291 Dummy_File_Control_Block : Text_AFCB;
1292 pragma Warnings (Off, Dummy_File_Control_Block);
1293 -- Yes, we know this is never assigned a value, only the tag
1294 -- is used for dispatching purposes, so that's expected.
1297 FIO.Open (File_Ptr => AP (File),
1298 Dummy_FCB => Dummy_File_Control_Block,
1299 Mode => To_FCB (Mode),
1314 -- Note: we assume that it is impossible in practice for the page
1315 -- to exceed the value of Count'Last, i.e. no check is required for
1316 -- overflow raising layout error.
1318 function Page (File : File_Type) return Positive_Count is
1320 FIO.Check_File_Open (AP (File));
1324 function Page return Positive_Count is
1326 return Page (Current_Out);
1333 function Page_Length (File : File_Type) return Count is
1335 FIO.Check_Write_Status (AP (File));
1336 return File.Page_Length;
1339 function Page_Length return Count is
1341 return Page_Length (Current_Out);
1353 FIO.Check_Write_Status (AP (File));
1355 if File.Line_Length /= 0 and then File.Col > File.Line_Length then
1359 -- If lower half character, or brackets encoding, output directly
1361 if Character'Pos (Item) < 16#80#
1362 or else File.WC_Method = WCEM_Brackets
1364 if fputc (Character'Pos (Item), File.Stream) = EOF then
1368 -- Case of upper half character with non-brackets encoding
1371 Put_Encoded (File, Item);
1374 File.Col := File.Col + 1;
1377 procedure Put (Item : Character) is
1379 FIO.Check_Write_Status (AP (Current_Out));
1381 if Current_Out.Line_Length /= 0
1382 and then Current_Out.Col > Current_Out.Line_Length
1384 New_Line (Current_Out);
1387 -- If lower half character, or brackets encoding, output directly
1389 if Character'Pos (Item) < 16#80#
1390 or else Default_WCEM = WCEM_Brackets
1392 if fputc (Character'Pos (Item), Current_Out.Stream) = EOF then
1396 -- Case of upper half character with non-brackets encoding
1399 Put_Encoded (Current_Out, Item);
1402 Current_Out.Col := Current_Out.Col + 1;
1414 FIO.Check_Write_Status (AP (File));
1416 -- Only have something to do if string is non-null
1418 if Item'Length > 0 then
1420 -- If we have bounded lines, or if the file encoding is other than
1421 -- Brackets and the string has at least one upper half character,
1422 -- then output the string character by character.
1424 if File.Line_Length /= 0
1425 or else (File.WC_Method /= WCEM_Brackets
1426 and then Has_Upper_Half_Character (Item))
1428 for J in Item'Range loop
1429 Put (File, Item (J));
1432 -- Otherwise we can output the entire string at once. Note that if
1433 -- there are LF or FF characters in the string, we do not bother to
1434 -- count them as line or page terminators.
1437 FIO.Write_Buf (AP (File), Item'Address, Item'Length);
1438 File.Col := File.Col + Item'Length;
1443 procedure Put (Item : String) is
1445 Put (Current_Out, Item);
1452 procedure Put_Encoded (File : File_Type; Char : Character) is
1453 procedure Out_Char (C : Character);
1454 -- Procedure to output one character of an upper half encoded sequence
1456 procedure WC_Out is new Wide_Char_To_Char_Sequence (Out_Char);
1462 procedure Out_Char (C : Character) is
1464 Putc (Character'Pos (C), File);
1467 -- Start of processing for Put_Encoded
1470 WC_Out (Wide_Character'Val (Character'Pos (Char)), File.WC_Method);
1481 Ilen : Natural := Item'Length;
1482 Istart : Natural := Item'First;
1485 FIO.Check_Write_Status (AP (File));
1487 -- If we have bounded lines, or if the file encoding is other than
1488 -- Brackets and the string has at least one upper half character, then
1489 -- output the string character by character.
1491 if File.Line_Length /= 0
1492 or else (File.WC_Method /= WCEM_Brackets
1493 and then Has_Upper_Half_Character (Item))
1495 for J in Item'Range loop
1496 Put (File, Item (J));
1503 -- Normal case where we do not need to output character by character
1505 -- We setup a single string that has the necessary terminators and
1506 -- then write it with a single call. The reason for doing this is
1507 -- that it gives better behavior for the use of Put_Line in multi-
1508 -- tasking programs, since often the OS will treat the entire put
1509 -- operation as an atomic operation.
1511 -- We only do this if the message is 512 characters or less in length,
1512 -- since otherwise Put_Line would use an unbounded amount of stack
1513 -- space and could cause undetected stack overflow. If we have a
1514 -- longer string, then output the first part separately to avoid this.
1517 FIO.Write_Buf (AP (File), Item'Address, size_t (Ilen - 512));
1518 Istart := Istart + Ilen - 512;
1522 -- Now prepare the string with its terminator
1525 Buffer : String (1 .. Ilen + 2);
1529 Buffer (1 .. Ilen) := Item (Istart .. Item'Last);
1530 Buffer (Ilen + 1) := Character'Val (LM);
1532 if File.Page_Length /= 0
1533 and then File.Line > File.Page_Length
1535 Buffer (Ilen + 2) := Character'Val (PM);
1536 Plen := size_t (Ilen) + 2;
1538 File.Page := File.Page + 1;
1541 Plen := size_t (Ilen) + 1;
1542 File.Line := File.Line + 1;
1545 FIO.Write_Buf (AP (File), Buffer'Address, Plen);
1551 procedure Put_Line (Item : String) is
1553 Put_Line (Current_Out, Item);
1560 procedure Putc (ch : int; File : File_Type) is
1562 if fputc (ch, File.Stream) = EOF then
1571 -- This is the primitive Stream Read routine, used when a Text_IO file
1572 -- is treated directly as a stream using Text_IO.Streams.Stream.
1575 (File : in out Text_AFCB;
1576 Item : out Stream_Element_Array;
1577 Last : out Stream_Element_Offset)
1580 pragma Warnings (Off, Discard_ch);
1583 -- Need to deal with Before_Upper_Half_Character ???
1585 if File.Mode /= FCB.In_File then
1589 -- Deal with case where our logical and physical position do not match
1590 -- because of being after an LM or LM-PM sequence when in fact we are
1591 -- logically positioned before it.
1593 if File.Before_LM then
1595 -- If we are before a PM, then it is possible for a stream read
1596 -- to leave us after the LM and before the PM, which is a bit
1597 -- odd. The easiest way to deal with this is to unget the PM,
1598 -- so we are indeed positioned between the characters. This way
1599 -- further stream read operations will work correctly, and the
1600 -- effect on text processing is a little weird, but what can
1601 -- be expected if stream and text input are mixed this way?
1603 if File.Before_LM_PM then
1604 Discard_ch := ungetc (PM, File.Stream);
1605 File.Before_LM_PM := False;
1608 File.Before_LM := False;
1610 Item (Item'First) := Stream_Element (Character'Pos (ASCII.LF));
1612 if Item'Length = 1 then
1618 Stream_Element_Offset
1619 (fread (buffer => Item'Address,
1620 index => size_t (Item'First + 1),
1622 count => Item'Length - 1,
1623 stream => File.Stream));
1629 -- Now we do the read. Since this is a text file, it is normally in
1630 -- text mode, but stream data must be read in binary mode, so we
1631 -- temporarily set binary mode for the read, resetting it after.
1632 -- These calls have no effect in a system (like Unix) where there is
1633 -- no distinction between text and binary files.
1635 set_binary_mode (fileno (File.Stream));
1639 Stream_Element_Offset
1640 (fread (Item'Address, 1, Item'Length, File.Stream)) - 1;
1642 if Last < Item'Last then
1643 if ferror (File.Stream) /= 0 then
1648 set_text_mode (fileno (File.Stream));
1656 (File : in out File_Type;
1660 -- Don't allow change of mode for current file (RM A.10.2(5))
1662 if (File = Current_In or else
1663 File = Current_Out or else
1664 File = Current_Error)
1665 and then To_FCB (Mode) /= File.Mode
1670 Terminate_Line (File);
1671 FIO.Reset (AP (File)'Unrestricted_Access, To_FCB (Mode));
1675 File.Line_Length := 0;
1676 File.Page_Length := 0;
1677 File.Before_LM := False;
1678 File.Before_LM_PM := False;
1681 procedure Reset (File : in out File_Type) is
1683 Terminate_Line (File);
1684 FIO.Reset (AP (File)'Unrestricted_Access);
1688 File.Line_Length := 0;
1689 File.Page_Length := 0;
1690 File.Before_LM := False;
1691 File.Before_LM_PM := False;
1700 To : Positive_Count)
1705 -- Raise Constraint_Error if out of range value. The reason for this
1706 -- explicit test is that we don't want junk values around, even if
1707 -- checks are off in the caller.
1709 if not To'Valid then
1710 raise Constraint_Error;
1713 FIO.Check_File_Open (AP (File));
1717 if Mode (File) >= Out_File then
1719 -- Error if we attempt to set Col to a value greater than the
1720 -- maximum permissible line length.
1722 if File.Line_Length /= 0 and then To > File.Line_Length then
1726 -- If we are behind current position, then go to start of new line
1728 if To < File.Col then
1732 -- Loop to output blanks till we are at the required column
1734 while File.Col < To loop
1741 -- If we are logically before a LM, but physically after it, the
1742 -- file position still reflects the position before the LM, so eat
1743 -- it now and adjust the file position appropriately.
1745 if File.Before_LM then
1746 File.Before_LM := False;
1747 File.Before_LM_PM := False;
1748 File.Line := File.Line + 1;
1752 -- Loop reading characters till we get one at the required Col value
1755 -- Read next character. The reason we have to read ahead is to
1756 -- skip formatting characters, the effect of Set_Col is to set
1757 -- us to a real character with the right Col value, and format
1758 -- characters don't count.
1762 -- Error if we hit an end of file
1767 -- If line mark, eat it and adjust file position
1770 File.Line := File.Line + 1;
1773 -- If recognized page mark, eat it, and adjust file position
1775 elsif ch = PM and then File.Is_Regular_File then
1776 File.Page := File.Page + 1;
1780 -- Otherwise this is the character we are looking for, so put it
1781 -- back in the input stream (we have not adjusted the file
1782 -- position yet, so everything is set right after this ungetc).
1784 elsif To = File.Col then
1788 -- Keep skipping characters if we are not there yet, updating the
1789 -- file position past the skipped character.
1792 File.Col := File.Col + 1;
1798 procedure Set_Col (To : Positive_Count) is
1800 Set_Col (Current_Out, To);
1807 procedure Set_Error (File : File_Type) is
1809 FIO.Check_Write_Status (AP (File));
1810 Current_Err := File;
1817 procedure Set_Input (File : File_Type) is
1819 FIO.Check_Read_Status (AP (File));
1829 To : Positive_Count)
1832 -- Raise Constraint_Error if out of range value. The reason for this
1833 -- explicit test is that we don't want junk values around, even if
1834 -- checks are off in the caller.
1836 if not To'Valid then
1837 raise Constraint_Error;
1840 FIO.Check_File_Open (AP (File));
1842 if To = File.Line then
1846 if Mode (File) >= Out_File then
1847 if File.Page_Length /= 0 and then To > File.Page_Length then
1851 if To < File.Line then
1855 while File.Line < To loop
1860 while To /= File.Line loop
1866 procedure Set_Line (To : Positive_Count) is
1868 Set_Line (Current_Out, To);
1871 ---------------------
1872 -- Set_Line_Length --
1873 ---------------------
1875 procedure Set_Line_Length (File : File_Type; To : Count) is
1877 -- Raise Constraint_Error if out of range value. The reason for this
1878 -- explicit test is that we don't want junk values around, even if
1879 -- checks are off in the caller.
1881 if not To'Valid then
1882 raise Constraint_Error;
1885 FIO.Check_Write_Status (AP (File));
1886 File.Line_Length := To;
1887 end Set_Line_Length;
1889 procedure Set_Line_Length (To : Count) is
1891 Set_Line_Length (Current_Out, To);
1892 end Set_Line_Length;
1898 procedure Set_Output (File : File_Type) is
1900 FIO.Check_Write_Status (AP (File));
1901 Current_Out := File;
1904 ---------------------
1905 -- Set_Page_Length --
1906 ---------------------
1908 procedure Set_Page_Length (File : File_Type; To : Count) is
1910 -- Raise Constraint_Error if out of range value. The reason for this
1911 -- explicit test is that we don't want junk values around, even if
1912 -- checks are off in the caller.
1914 if not To'Valid then
1915 raise Constraint_Error;
1918 FIO.Check_Write_Status (AP (File));
1919 File.Page_Length := To;
1920 end Set_Page_Length;
1922 procedure Set_Page_Length (To : Count) is
1924 Set_Page_Length (Current_Out, To);
1925 end Set_Page_Length;
1931 procedure Set_WCEM (File : in out File_Type) is
1936 File.WC_Method := WCEM_Brackets;
1937 FIO.Form_Parameter (File.Form.all, "wcem", Start, Stop);
1940 File.WC_Method := WCEM_Brackets;
1943 if Stop = Start then
1944 for J in WC_Encoding_Letters'Range loop
1945 if File.Form (Start) = WC_Encoding_Letters (J) then
1946 File.WC_Method := J;
1953 raise Use_Error with "invalid WCEM form parameter";
1963 Spacing : Positive_Count := 1)
1968 -- Raise Constraint_Error if out of range value. The reason for this
1969 -- explicit test is that we don't want junk values around, even if
1970 -- checks are off in the caller.
1972 if not Spacing'Valid then
1973 raise Constraint_Error;
1976 FIO.Check_Read_Status (AP (File));
1978 for L in 1 .. Spacing loop
1979 if File.Before_LM then
1980 File.Before_LM := False;
1982 -- Note that if File.Before_LM_PM is currently set, we also have
1983 -- to reset it (because it makes sense for Before_LM_PM to be set
1984 -- only when Before_LM is also set). This is done later on in this
1985 -- subprogram, as soon as Before_LM_PM has been taken into account
1986 -- for the purpose of page and line counts.
1991 -- If at end of file now, then immediately raise End_Error. Note
1992 -- that we can never be positioned between a line mark and a page
1993 -- mark, so if we are at the end of file, we cannot logically be
1994 -- before the implicit page mark that is at the end of the file.
1996 -- For the same reason, we do not need an explicit check for a
1997 -- page mark. If there is a FF in the middle of a line, the file
1998 -- is not in canonical format and we do not care about the page
1999 -- numbers for files other than ones in canonical format.
2005 -- If not at end of file, then loop till we get to an LM or EOF.
2006 -- The latter case happens only in non-canonical files where the
2007 -- last line is not terminated by LM, but we don't want to blow
2008 -- up for such files, so we assume an implicit LM in this case.
2011 exit when ch = LM or else ch = EOF;
2016 -- We have got past a line mark, now, for a regular file only,
2017 -- see if a page mark immediately follows this line mark and
2018 -- if so, skip past the page mark as well. We do not do this
2019 -- for non-regular files, since it would cause an undesirable
2020 -- wait for an additional character.
2023 File.Line := File.Line + 1;
2025 if File.Before_LM_PM then
2026 File.Page := File.Page + 1;
2028 File.Before_LM_PM := False;
2030 elsif File.Is_Regular_File then
2033 -- Page mark can be explicit, or implied at the end of the file
2035 if (ch = PM or else ch = EOF)
2036 and then File.Is_Regular_File
2038 File.Page := File.Page + 1;
2046 File.Before_Upper_Half_Character := False;
2049 procedure Skip_Line (Spacing : Positive_Count := 1) is
2051 Skip_Line (Current_In, Spacing);
2058 procedure Skip_Page (File : File_Type) is
2062 FIO.Check_Read_Status (AP (File));
2064 -- If at page mark already, just skip it
2066 if File.Before_LM_PM then
2067 File.Before_LM := False;
2068 File.Before_LM_PM := False;
2069 File.Page := File.Page + 1;
2075 -- This is a bit tricky, if we are logically before an LM then
2076 -- it is not an error if we are at an end of file now, since we
2077 -- are not really at it.
2079 if File.Before_LM then
2080 File.Before_LM := False;
2081 File.Before_LM_PM := False;
2084 -- Otherwise we do raise End_Error if we are at the end of file now
2094 -- Now we can just rumble along to the next page mark, or to the
2095 -- end of file, if that comes first. The latter case happens when
2096 -- the page mark is implied at the end of file.
2100 or else (ch = PM and then File.Is_Regular_File);
2104 File.Page := File.Page + 1;
2107 File.Before_Upper_Half_Character := False;
2110 procedure Skip_Page is
2112 Skip_Page (Current_In);
2115 --------------------
2116 -- Standard_Error --
2117 --------------------
2119 function Standard_Error return File_Type is
2121 return Standard_Err;
2124 function Standard_Error return File_Access is
2126 return Standard_Err'Access;
2129 --------------------
2130 -- Standard_Input --
2131 --------------------
2133 function Standard_Input return File_Type is
2138 function Standard_Input return File_Access is
2140 return Standard_In'Access;
2143 ---------------------
2144 -- Standard_Output --
2145 ---------------------
2147 function Standard_Output return File_Type is
2149 return Standard_Out;
2150 end Standard_Output;
2152 function Standard_Output return File_Access is
2154 return Standard_Out'Access;
2155 end Standard_Output;
2157 --------------------
2158 -- Terminate_Line --
2159 --------------------
2161 procedure Terminate_Line (File : File_Type) is
2163 FIO.Check_File_Open (AP (File));
2165 -- For file other than In_File, test for needing to terminate last line
2167 if Mode (File) /= In_File then
2169 -- If not at start of line definition need new line
2171 if File.Col /= 1 then
2174 -- For files other than standard error and standard output, we
2175 -- make sure that an empty file has a single line feed, so that
2176 -- it is properly formatted. We avoid this for the standard files
2177 -- because it is too much of a nuisance to have these odd line
2178 -- feeds when nothing has been written to the file.
2180 -- We also avoid this for files opened in append mode, in
2181 -- accordance with (RM A.8.2(10))
2183 elsif (File /= Standard_Err and then File /= Standard_Out)
2184 and then (File.Line = 1 and then File.Page = 1)
2185 and then Mode (File) = Out_File
2196 procedure Ungetc (ch : int; File : File_Type) is
2199 if ungetc (ch, File.Stream) = EOF then
2209 -- This is the primitive Stream Write routine, used when a Text_IO file
2210 -- is treated directly as a stream using Text_IO.Streams.Stream.
2213 (File : in out Text_AFCB;
2214 Item : Stream_Element_Array)
2216 pragma Warnings (Off, File);
2217 -- Because in this implementation we don't need IN OUT, we only read
2219 function Has_Translated_Characters return Boolean;
2220 -- return True if Item array contains a character which will be
2221 -- translated under the text file mode. There is only one such
2222 -- character under DOS based systems which is character 10.
2224 text_translation_required : Boolean;
2225 for text_translation_required'Size use Character'Size;
2226 pragma Import (C, text_translation_required,
2227 "__gnat_text_translation_required");
2229 Siz : constant size_t := Item'Length;
2231 -------------------------------
2232 -- Has_Translated_Characters --
2233 -------------------------------
2235 function Has_Translated_Characters return Boolean is
2237 for K in Item'Range loop
2238 if Item (K) = 10 then
2243 end Has_Translated_Characters;
2245 Needs_Binary_Write : constant Boolean :=
2246 text_translation_required
2247 and then Has_Translated_Characters;
2249 -- Start of processing for Write
2252 if File.Mode = FCB.In_File then
2256 -- Now we do the write. Since this is a text file, it is normally in
2257 -- text mode, but stream data must be written in binary mode, so we
2258 -- temporarily set binary mode for the write, resetting it after. This
2259 -- is done only if needed (i.e. there is some characters in Item which
2260 -- needs to be written using the binary mode).
2261 -- These calls have no effect in a system (like Unix) where there is
2262 -- no distinction between text and binary files.
2264 -- Since the character translation is done at the time the buffer is
2265 -- written (this is true under Windows) we first flush current buffer
2266 -- with text mode if needed.
2268 if Needs_Binary_Write then
2269 if fflush (File.Stream) = -1 then
2273 set_binary_mode (fileno (File.Stream));
2276 if fwrite (Item'Address, 1, Siz, File.Stream) /= Siz then
2280 -- At this point we need to flush the buffer using the binary mode then
2281 -- we reset to text mode.
2283 if Needs_Binary_Write then
2284 if fflush (File.Stream) = -1 then
2288 set_text_mode (fileno (File.Stream));
2293 -- Initialize Standard Files
2295 for J in WC_Encoding_Method loop
2296 if WC_Encoding = WC_Encoding_Letters (J) then
2301 Initialize_Standard_Files;
2303 FIO.Chain_File (AP (Standard_In));
2304 FIO.Chain_File (AP (Standard_Out));
2305 FIO.Chain_File (AP (Standard_Err));