1 ------------------------------------------------------------------------------
3 -- GNAT RUN-TIME COMPONENTS --
5 -- A D A . T E X T _ I O --
9 -- Copyright (C) 1992-2010, 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);
694 Last : out Natural) is separate;
695 -- The implementation of Ada.Text_IO.Get_Line is split into a subunit so
696 -- that different implementations can be used on different systems. In
697 -- particular the standard implementation uses low level stuff that is
698 -- not appropriate for the JVM and .NET implementations.
705 Get_Line (Current_In, Item, Last);
708 function Get_Line (File : File_Type) return String is
709 Buffer : String (1 .. 500);
712 function Get_Rest (S : String) return String;
713 -- This is a recursive function that reads the rest of the line and
714 -- returns it. S is the part read so far.
720 function Get_Rest (S : String) return String is
722 -- Each time we allocate a buffer the same size as what we have
723 -- read so far. This limits us to a logarithmic number of calls
724 -- to Get_Rest and also ensures only a linear use of stack space.
726 Buffer : String (1 .. S'Length);
730 Get_Line (File, Buffer, Last);
733 R : constant String := S & Buffer (1 .. Last);
735 if Last < Buffer'Last then
743 -- Start of processing for Get_Line
746 Get_Line (File, Buffer, Last);
748 if Last < Buffer'Last then
749 return Buffer (1 .. Last);
751 return Get_Rest (Buffer (1 .. Last));
755 function Get_Line return String is
757 return Get_Line (Current_In);
760 -------------------------
761 -- Get_Upper_Half_Char --
762 -------------------------
764 function Get_Upper_Half_Char
766 File : File_Type) return Character
768 Result : Wide_Character;
770 function In_Char return Character;
771 -- Function used to obtain additional characters it the wide character
772 -- sequence is more than one character long.
774 function WC_In is new Char_Sequence_To_Wide_Char (In_Char);
780 function In_Char return Character is
781 ch : constant Integer := Getc (File);
786 return Character'Val (ch);
790 -- Start of processing for Get_Upper_Half_Char
793 Result := WC_In (C, File.WC_Method);
795 if Wide_Character'Pos (Result) > 16#FF# then
796 raise Constraint_Error with
797 "invalid wide character in Text_'I'O input";
799 return Character'Val (Wide_Character'Pos (Result));
801 end Get_Upper_Half_Char;
803 -------------------------------
804 -- Get_Upper_Half_Char_Immed --
805 -------------------------------
807 function Get_Upper_Half_Char_Immed
809 File : File_Type) return Character
811 Result : Wide_Character;
813 function In_Char return Character;
814 -- Function used to obtain additional characters it the wide character
815 -- sequence is more than one character long.
817 function WC_In is new Char_Sequence_To_Wide_Char (In_Char);
823 function In_Char return Character is
824 ch : constant Integer := Getc_Immed (File);
829 return Character'Val (ch);
833 -- Start of processing for Get_Upper_Half_Char_Immed
836 Result := WC_In (C, File.WC_Method);
838 if Wide_Character'Pos (Result) > 16#FF# then
839 raise Constraint_Error with
840 "invalid wide character in Text_'I'O input";
842 return Character'Val (Wide_Character'Pos (Result));
844 end Get_Upper_Half_Char_Immed;
850 function Getc (File : File_Type) return int is
854 ch := fgetc (File.Stream);
856 if ch = EOF and then ferror (File.Stream) /= 0 then
867 function Getc_Immed (File : File_Type) return int is
871 procedure getc_immediate
872 (stream : FILEs; ch : out int; end_of_file : out int);
873 pragma Import (C, getc_immediate, "getc_immediate");
876 FIO.Check_Read_Status (AP (File));
878 if File.Before_LM then
879 File.Before_LM := False;
880 File.Before_LM_PM := False;
884 getc_immediate (File.Stream, ch, end_of_file);
886 if ferror (File.Stream) /= 0 then
888 elsif end_of_file /= 0 then
896 ------------------------------
897 -- Has_Upper_Half_Character --
898 ------------------------------
900 function Has_Upper_Half_Character (Item : String) return Boolean is
902 for J in Item'Range loop
903 if Character'Pos (Item (J)) >= 16#80# then
909 end Has_Upper_Half_Character;
911 -------------------------------
912 -- Initialize_Standard_Files --
913 -------------------------------
915 procedure Initialize_Standard_Files is
917 Standard_Err.Stream := stderr;
918 Standard_Err.Name := Err_Name'Access;
919 Standard_Err.Form := Null_Str'Unrestricted_Access;
920 Standard_Err.Mode := FCB.Out_File;
921 Standard_Err.Is_Regular_File := is_regular_file (fileno (stderr)) /= 0;
922 Standard_Err.Is_Temporary_File := False;
923 Standard_Err.Is_System_File := True;
924 Standard_Err.Is_Text_File := True;
925 Standard_Err.Access_Method := 'T';
926 Standard_Err.Self := Standard_Err;
927 Standard_Err.WC_Method := Default_WCEM;
929 Standard_In.Stream := stdin;
930 Standard_In.Name := In_Name'Access;
931 Standard_In.Form := Null_Str'Unrestricted_Access;
932 Standard_In.Mode := FCB.In_File;
933 Standard_In.Is_Regular_File := is_regular_file (fileno (stdin)) /= 0;
934 Standard_In.Is_Temporary_File := False;
935 Standard_In.Is_System_File := True;
936 Standard_In.Is_Text_File := True;
937 Standard_In.Access_Method := 'T';
938 Standard_In.Self := Standard_In;
939 Standard_In.WC_Method := Default_WCEM;
941 Standard_Out.Stream := stdout;
942 Standard_Out.Name := Out_Name'Access;
943 Standard_Out.Form := Null_Str'Unrestricted_Access;
944 Standard_Out.Mode := FCB.Out_File;
945 Standard_Out.Is_Regular_File := is_regular_file (fileno (stdout)) /= 0;
946 Standard_Out.Is_Temporary_File := False;
947 Standard_Out.Is_System_File := True;
948 Standard_Out.Is_Text_File := True;
949 Standard_Out.Access_Method := 'T';
950 Standard_Out.Self := Standard_Out;
951 Standard_Out.WC_Method := Default_WCEM;
953 FIO.Make_Unbuffered (AP (Standard_Out));
954 FIO.Make_Unbuffered (AP (Standard_Err));
955 end Initialize_Standard_Files;
961 function Is_Open (File : File_Type) return Boolean is
963 return FIO.Is_Open (AP (File));
970 -- Note: we assume that it is impossible in practice for the line
971 -- to exceed the value of Count'Last, i.e. no check is required for
972 -- overflow raising layout error.
974 function Line (File : File_Type) return Positive_Count is
976 FIO.Check_File_Open (AP (File));
980 function Line return Positive_Count is
982 return Line (Current_Out);
989 function Line_Length (File : File_Type) return Count is
991 FIO.Check_Write_Status (AP (File));
992 return File.Line_Length;
995 function Line_Length return Count is
997 return Line_Length (Current_Out);
1004 procedure Look_Ahead
1006 Item : out Character;
1007 End_Of_Line : out Boolean)
1012 FIO.Check_Read_Status (AP (File));
1014 -- If we are logically before a line mark, we can return immediately
1016 if File.Before_LM then
1017 End_Of_Line := True;
1020 -- If we are before an upper half character just return it (this can
1021 -- happen if there are two calls to Look_Ahead in a row).
1023 elsif File.Before_Upper_Half_Character then
1024 End_Of_Line := False;
1025 Item := File.Saved_Upper_Half_Character;
1027 -- Otherwise we must read a character from the input stream
1034 or else (ch = PM and then File.Is_Regular_File)
1036 End_Of_Line := True;
1040 -- Case where character obtained does not represent the start of an
1041 -- encoded sequence so it stands for itself and we can unget it with
1044 elsif not Is_Start_Of_Encoding
1045 (Character'Val (ch), File.WC_Method)
1047 End_Of_Line := False;
1049 Item := Character'Val (ch);
1051 -- For the start of an encoding, we read the character using the
1052 -- Get_Upper_Half_Char routine. It will occupy more than one byte
1053 -- so we can't put it back with ungetc. Instead we save it in the
1054 -- control block, setting a flag that everyone interested in reading
1055 -- characters must test before reading the stream.
1058 Item := Get_Upper_Half_Char (Character'Val (ch), File);
1059 End_Of_Line := False;
1060 File.Saved_Upper_Half_Character := Item;
1061 File.Before_Upper_Half_Character := True;
1066 procedure Look_Ahead
1067 (Item : out Character;
1068 End_Of_Line : out Boolean)
1071 Look_Ahead (Current_In, Item, End_Of_Line);
1078 function Mode (File : File_Type) return File_Mode is
1080 return To_TIO (FIO.Mode (AP (File)));
1087 function Name (File : File_Type) return String is
1089 return FIO.Name (AP (File));
1098 Spacing : Positive_Count := 1)
1101 -- Raise Constraint_Error if out of range value. The reason for this
1102 -- explicit test is that we don't want junk values around, even if
1103 -- checks are off in the caller.
1105 if not Spacing'Valid then
1106 raise Constraint_Error;
1109 FIO.Check_Write_Status (AP (File));
1111 for K in 1 .. Spacing loop
1113 File.Line := File.Line + 1;
1115 if File.Page_Length /= 0
1116 and then File.Line > File.Page_Length
1120 File.Page := File.Page + 1;
1127 procedure New_Line (Spacing : Positive_Count := 1) is
1129 New_Line (Current_Out, Spacing);
1136 procedure New_Page (File : File_Type) is
1138 FIO.Check_Write_Status (AP (File));
1140 if File.Col /= 1 or else File.Line = 1 then
1145 File.Page := File.Page + 1;
1150 procedure New_Page is
1152 New_Page (Current_Out);
1159 function Nextc (File : File_Type) return int is
1163 ch := fgetc (File.Stream);
1166 if ferror (File.Stream) /= 0 then
1171 if ungetc (ch, File.Stream) = EOF then
1184 (File : in out File_Type;
1187 Form : String := "")
1189 Dummy_File_Control_Block : Text_AFCB;
1190 pragma Warnings (Off, Dummy_File_Control_Block);
1191 -- Yes, we know this is never assigned a value, only the tag
1192 -- is used for dispatching purposes, so that's expected.
1195 FIO.Open (File_Ptr => AP (File),
1196 Dummy_FCB => Dummy_File_Control_Block,
1197 Mode => To_FCB (Mode),
1212 -- Note: we assume that it is impossible in practice for the page
1213 -- to exceed the value of Count'Last, i.e. no check is required for
1214 -- overflow raising layout error.
1216 function Page (File : File_Type) return Positive_Count is
1218 FIO.Check_File_Open (AP (File));
1222 function Page return Positive_Count is
1224 return Page (Current_Out);
1231 function Page_Length (File : File_Type) return Count is
1233 FIO.Check_Write_Status (AP (File));
1234 return File.Page_Length;
1237 function Page_Length return Count is
1239 return Page_Length (Current_Out);
1251 FIO.Check_Write_Status (AP (File));
1253 if File.Line_Length /= 0 and then File.Col > File.Line_Length then
1257 -- If lower half character, or brackets encoding, output directly
1259 if Character'Pos (Item) < 16#80#
1260 or else File.WC_Method = WCEM_Brackets
1262 if fputc (Character'Pos (Item), File.Stream) = EOF then
1266 -- Case of upper half character with non-brackets encoding
1269 Put_Encoded (File, Item);
1272 File.Col := File.Col + 1;
1275 procedure Put (Item : Character) is
1277 FIO.Check_Write_Status (AP (Current_Out));
1279 if Current_Out.Line_Length /= 0
1280 and then Current_Out.Col > Current_Out.Line_Length
1282 New_Line (Current_Out);
1285 -- If lower half character, or brackets encoding, output directly
1287 if Character'Pos (Item) < 16#80#
1288 or else Default_WCEM = WCEM_Brackets
1290 if fputc (Character'Pos (Item), Current_Out.Stream) = EOF then
1294 -- Case of upper half character with non-brackets encoding
1297 Put_Encoded (Current_Out, Item);
1300 Current_Out.Col := Current_Out.Col + 1;
1312 FIO.Check_Write_Status (AP (File));
1314 -- Only have something to do if string is non-null
1316 if Item'Length > 0 then
1318 -- If we have bounded lines, or if the file encoding is other than
1319 -- Brackets and the string has at least one upper half character,
1320 -- then output the string character by character.
1322 if File.Line_Length /= 0
1323 or else (File.WC_Method /= WCEM_Brackets
1324 and then Has_Upper_Half_Character (Item))
1326 for J in Item'Range loop
1327 Put (File, Item (J));
1330 -- Otherwise we can output the entire string at once. Note that if
1331 -- there are LF or FF characters in the string, we do not bother to
1332 -- count them as line or page terminators.
1335 FIO.Write_Buf (AP (File), Item'Address, Item'Length);
1336 File.Col := File.Col + Item'Length;
1341 procedure Put (Item : String) is
1343 Put (Current_Out, Item);
1350 procedure Put_Encoded (File : File_Type; Char : Character) is
1351 procedure Out_Char (C : Character);
1352 -- Procedure to output one character of an upper half encoded sequence
1354 procedure WC_Out is new Wide_Char_To_Char_Sequence (Out_Char);
1360 procedure Out_Char (C : Character) is
1362 Putc (Character'Pos (C), File);
1365 -- Start of processing for Put_Encoded
1368 WC_Out (Wide_Character'Val (Character'Pos (Char)), File.WC_Method);
1379 Ilen : Natural := Item'Length;
1380 Istart : Natural := Item'First;
1383 FIO.Check_Write_Status (AP (File));
1385 -- If we have bounded lines, or if the file encoding is other than
1386 -- Brackets and the string has at least one upper half character, then
1387 -- output the string character by character.
1389 if File.Line_Length /= 0
1390 or else (File.WC_Method /= WCEM_Brackets
1391 and then Has_Upper_Half_Character (Item))
1393 for J in Item'Range loop
1394 Put (File, Item (J));
1401 -- Normal case where we do not need to output character by character
1403 -- We setup a single string that has the necessary terminators and
1404 -- then write it with a single call. The reason for doing this is
1405 -- that it gives better behavior for the use of Put_Line in multi-
1406 -- tasking programs, since often the OS will treat the entire put
1407 -- operation as an atomic operation.
1409 -- We only do this if the message is 512 characters or less in length,
1410 -- since otherwise Put_Line would use an unbounded amount of stack
1411 -- space and could cause undetected stack overflow. If we have a
1412 -- longer string, then output the first part separately to avoid this.
1415 FIO.Write_Buf (AP (File), Item'Address, size_t (Ilen - 512));
1416 Istart := Istart + Ilen - 512;
1420 -- Now prepare the string with its terminator
1423 Buffer : String (1 .. Ilen + 2);
1427 Buffer (1 .. Ilen) := Item (Istart .. Item'Last);
1428 Buffer (Ilen + 1) := Character'Val (LM);
1430 if File.Page_Length /= 0
1431 and then File.Line > File.Page_Length
1433 Buffer (Ilen + 2) := Character'Val (PM);
1434 Plen := size_t (Ilen) + 2;
1436 File.Page := File.Page + 1;
1439 Plen := size_t (Ilen) + 1;
1440 File.Line := File.Line + 1;
1443 FIO.Write_Buf (AP (File), Buffer'Address, Plen);
1449 procedure Put_Line (Item : String) is
1451 Put_Line (Current_Out, Item);
1458 procedure Putc (ch : int; File : File_Type) is
1460 if fputc (ch, File.Stream) = EOF then
1469 -- This is the primitive Stream Read routine, used when a Text_IO file
1470 -- is treated directly as a stream using Text_IO.Streams.Stream.
1473 (File : in out Text_AFCB;
1474 Item : out Stream_Element_Array;
1475 Last : out Stream_Element_Offset)
1478 pragma Warnings (Off, Discard_ch);
1481 -- Need to deal with Before_Upper_Half_Character ???
1483 if File.Mode /= FCB.In_File then
1487 -- Deal with case where our logical and physical position do not match
1488 -- because of being after an LM or LM-PM sequence when in fact we are
1489 -- logically positioned before it.
1491 if File.Before_LM then
1493 -- If we are before a PM, then it is possible for a stream read
1494 -- to leave us after the LM and before the PM, which is a bit
1495 -- odd. The easiest way to deal with this is to unget the PM,
1496 -- so we are indeed positioned between the characters. This way
1497 -- further stream read operations will work correctly, and the
1498 -- effect on text processing is a little weird, but what can
1499 -- be expected if stream and text input are mixed this way?
1501 if File.Before_LM_PM then
1502 Discard_ch := ungetc (PM, File.Stream);
1503 File.Before_LM_PM := False;
1506 File.Before_LM := False;
1508 Item (Item'First) := Stream_Element (Character'Pos (ASCII.LF));
1510 if Item'Length = 1 then
1516 Stream_Element_Offset
1517 (fread (buffer => Item'Address,
1518 index => size_t (Item'First + 1),
1520 count => Item'Length - 1,
1521 stream => File.Stream));
1527 -- Now we do the read. Since this is a text file, it is normally in
1528 -- text mode, but stream data must be read in binary mode, so we
1529 -- temporarily set binary mode for the read, resetting it after.
1530 -- These calls have no effect in a system (like Unix) where there is
1531 -- no distinction between text and binary files.
1533 set_binary_mode (fileno (File.Stream));
1537 Stream_Element_Offset
1538 (fread (Item'Address, 1, Item'Length, File.Stream)) - 1;
1540 if Last < Item'Last then
1541 if ferror (File.Stream) /= 0 then
1546 set_text_mode (fileno (File.Stream));
1554 (File : in out File_Type;
1558 -- Don't allow change of mode for current file (RM A.10.2(5))
1560 if (File = Current_In or else
1561 File = Current_Out or else
1562 File = Current_Error)
1563 and then To_FCB (Mode) /= File.Mode
1568 Terminate_Line (File);
1569 FIO.Reset (AP (File)'Unrestricted_Access, To_FCB (Mode));
1573 File.Line_Length := 0;
1574 File.Page_Length := 0;
1575 File.Before_LM := False;
1576 File.Before_LM_PM := False;
1579 procedure Reset (File : in out File_Type) is
1581 Terminate_Line (File);
1582 FIO.Reset (AP (File)'Unrestricted_Access);
1586 File.Line_Length := 0;
1587 File.Page_Length := 0;
1588 File.Before_LM := False;
1589 File.Before_LM_PM := False;
1598 To : Positive_Count)
1603 -- Raise Constraint_Error if out of range value. The reason for this
1604 -- explicit test is that we don't want junk values around, even if
1605 -- checks are off in the caller.
1607 if not To'Valid then
1608 raise Constraint_Error;
1611 FIO.Check_File_Open (AP (File));
1615 if Mode (File) >= Out_File then
1617 -- Error if we attempt to set Col to a value greater than the
1618 -- maximum permissible line length.
1620 if File.Line_Length /= 0 and then To > File.Line_Length then
1624 -- If we are behind current position, then go to start of new line
1626 if To < File.Col then
1630 -- Loop to output blanks till we are at the required column
1632 while File.Col < To loop
1639 -- If we are logically before a LM, but physically after it, the
1640 -- file position still reflects the position before the LM, so eat
1641 -- it now and adjust the file position appropriately.
1643 if File.Before_LM then
1644 File.Before_LM := False;
1645 File.Before_LM_PM := False;
1646 File.Line := File.Line + 1;
1650 -- Loop reading characters till we get one at the required Col value
1653 -- Read next character. The reason we have to read ahead is to
1654 -- skip formatting characters, the effect of Set_Col is to set
1655 -- us to a real character with the right Col value, and format
1656 -- characters don't count.
1660 -- Error if we hit an end of file
1665 -- If line mark, eat it and adjust file position
1668 File.Line := File.Line + 1;
1671 -- If recognized page mark, eat it, and adjust file position
1673 elsif ch = PM and then File.Is_Regular_File then
1674 File.Page := File.Page + 1;
1678 -- Otherwise this is the character we are looking for, so put it
1679 -- back in the input stream (we have not adjusted the file
1680 -- position yet, so everything is set right after this ungetc).
1682 elsif To = File.Col then
1686 -- Keep skipping characters if we are not there yet, updating the
1687 -- file position past the skipped character.
1690 File.Col := File.Col + 1;
1696 procedure Set_Col (To : Positive_Count) is
1698 Set_Col (Current_Out, To);
1705 procedure Set_Error (File : File_Type) is
1707 FIO.Check_Write_Status (AP (File));
1708 Current_Err := File;
1715 procedure Set_Input (File : File_Type) is
1717 FIO.Check_Read_Status (AP (File));
1727 To : Positive_Count)
1730 -- Raise Constraint_Error if out of range value. The reason for this
1731 -- explicit test is that we don't want junk values around, even if
1732 -- checks are off in the caller.
1734 if not To'Valid then
1735 raise Constraint_Error;
1738 FIO.Check_File_Open (AP (File));
1740 if To = File.Line then
1744 if Mode (File) >= Out_File then
1745 if File.Page_Length /= 0 and then To > File.Page_Length then
1749 if To < File.Line then
1753 while File.Line < To loop
1758 while To /= File.Line loop
1764 procedure Set_Line (To : Positive_Count) is
1766 Set_Line (Current_Out, To);
1769 ---------------------
1770 -- Set_Line_Length --
1771 ---------------------
1773 procedure Set_Line_Length (File : File_Type; To : Count) is
1775 -- Raise Constraint_Error if out of range value. The reason for this
1776 -- explicit test is that we don't want junk values around, even if
1777 -- checks are off in the caller.
1779 if not To'Valid then
1780 raise Constraint_Error;
1783 FIO.Check_Write_Status (AP (File));
1784 File.Line_Length := To;
1785 end Set_Line_Length;
1787 procedure Set_Line_Length (To : Count) is
1789 Set_Line_Length (Current_Out, To);
1790 end Set_Line_Length;
1796 procedure Set_Output (File : File_Type) is
1798 FIO.Check_Write_Status (AP (File));
1799 Current_Out := File;
1802 ---------------------
1803 -- Set_Page_Length --
1804 ---------------------
1806 procedure Set_Page_Length (File : File_Type; To : Count) is
1808 -- Raise Constraint_Error if out of range value. The reason for this
1809 -- explicit test is that we don't want junk values around, even if
1810 -- checks are off in the caller.
1812 if not To'Valid then
1813 raise Constraint_Error;
1816 FIO.Check_Write_Status (AP (File));
1817 File.Page_Length := To;
1818 end Set_Page_Length;
1820 procedure Set_Page_Length (To : Count) is
1822 Set_Page_Length (Current_Out, To);
1823 end Set_Page_Length;
1829 procedure Set_WCEM (File : in out File_Type) is
1834 File.WC_Method := WCEM_Brackets;
1835 FIO.Form_Parameter (File.Form.all, "wcem", Start, Stop);
1838 File.WC_Method := WCEM_Brackets;
1841 if Stop = Start then
1842 for J in WC_Encoding_Letters'Range loop
1843 if File.Form (Start) = WC_Encoding_Letters (J) then
1844 File.WC_Method := J;
1851 raise Use_Error with "invalid WCEM form parameter";
1861 Spacing : Positive_Count := 1)
1866 -- Raise Constraint_Error if out of range value. The reason for this
1867 -- explicit test is that we don't want junk values around, even if
1868 -- checks are off in the caller.
1870 if not Spacing'Valid then
1871 raise Constraint_Error;
1874 FIO.Check_Read_Status (AP (File));
1876 for L in 1 .. Spacing loop
1877 if File.Before_LM then
1878 File.Before_LM := False;
1880 -- Note that if File.Before_LM_PM is currently set, we also have
1881 -- to reset it (because it makes sense for Before_LM_PM to be set
1882 -- only when Before_LM is also set). This is done later on in this
1883 -- subprogram, as soon as Before_LM_PM has been taken into account
1884 -- for the purpose of page and line counts.
1889 -- If at end of file now, then immediately raise End_Error. Note
1890 -- that we can never be positioned between a line mark and a page
1891 -- mark, so if we are at the end of file, we cannot logically be
1892 -- before the implicit page mark that is at the end of the file.
1894 -- For the same reason, we do not need an explicit check for a
1895 -- page mark. If there is a FF in the middle of a line, the file
1896 -- is not in canonical format and we do not care about the page
1897 -- numbers for files other than ones in canonical format.
1903 -- If not at end of file, then loop till we get to an LM or EOF.
1904 -- The latter case happens only in non-canonical files where the
1905 -- last line is not terminated by LM, but we don't want to blow
1906 -- up for such files, so we assume an implicit LM in this case.
1909 exit when ch = LM or else ch = EOF;
1914 -- We have got past a line mark, now, for a regular file only,
1915 -- see if a page mark immediately follows this line mark and
1916 -- if so, skip past the page mark as well. We do not do this
1917 -- for non-regular files, since it would cause an undesirable
1918 -- wait for an additional character.
1921 File.Line := File.Line + 1;
1923 if File.Before_LM_PM then
1924 File.Page := File.Page + 1;
1926 File.Before_LM_PM := False;
1928 elsif File.Is_Regular_File then
1931 -- Page mark can be explicit, or implied at the end of the file
1933 if (ch = PM or else ch = EOF)
1934 and then File.Is_Regular_File
1936 File.Page := File.Page + 1;
1944 File.Before_Upper_Half_Character := False;
1947 procedure Skip_Line (Spacing : Positive_Count := 1) is
1949 Skip_Line (Current_In, Spacing);
1956 procedure Skip_Page (File : File_Type) is
1960 FIO.Check_Read_Status (AP (File));
1962 -- If at page mark already, just skip it
1964 if File.Before_LM_PM then
1965 File.Before_LM := False;
1966 File.Before_LM_PM := False;
1967 File.Page := File.Page + 1;
1973 -- This is a bit tricky, if we are logically before an LM then
1974 -- it is not an error if we are at an end of file now, since we
1975 -- are not really at it.
1977 if File.Before_LM then
1978 File.Before_LM := False;
1979 File.Before_LM_PM := False;
1982 -- Otherwise we do raise End_Error if we are at the end of file now
1992 -- Now we can just rumble along to the next page mark, or to the
1993 -- end of file, if that comes first. The latter case happens when
1994 -- the page mark is implied at the end of file.
1998 or else (ch = PM and then File.Is_Regular_File);
2002 File.Page := File.Page + 1;
2005 File.Before_Upper_Half_Character := False;
2008 procedure Skip_Page is
2010 Skip_Page (Current_In);
2013 --------------------
2014 -- Standard_Error --
2015 --------------------
2017 function Standard_Error return File_Type is
2019 return Standard_Err;
2022 function Standard_Error return File_Access is
2024 return Standard_Err'Access;
2027 --------------------
2028 -- Standard_Input --
2029 --------------------
2031 function Standard_Input return File_Type is
2036 function Standard_Input return File_Access is
2038 return Standard_In'Access;
2041 ---------------------
2042 -- Standard_Output --
2043 ---------------------
2045 function Standard_Output return File_Type is
2047 return Standard_Out;
2048 end Standard_Output;
2050 function Standard_Output return File_Access is
2052 return Standard_Out'Access;
2053 end Standard_Output;
2055 --------------------
2056 -- Terminate_Line --
2057 --------------------
2059 procedure Terminate_Line (File : File_Type) is
2061 FIO.Check_File_Open (AP (File));
2063 -- For file other than In_File, test for needing to terminate last line
2065 if Mode (File) /= In_File then
2067 -- If not at start of line definition need new line
2069 if File.Col /= 1 then
2072 -- For files other than standard error and standard output, we
2073 -- make sure that an empty file has a single line feed, so that
2074 -- it is properly formatted. We avoid this for the standard files
2075 -- because it is too much of a nuisance to have these odd line
2076 -- feeds when nothing has been written to the file.
2078 -- We also avoid this for files opened in append mode, in
2079 -- accordance with (RM A.8.2(10))
2081 elsif (File /= Standard_Err and then File /= Standard_Out)
2082 and then (File.Line = 1 and then File.Page = 1)
2083 and then Mode (File) = Out_File
2094 procedure Ungetc (ch : int; File : File_Type) is
2097 if ungetc (ch, File.Stream) = EOF then
2107 -- This is the primitive Stream Write routine, used when a Text_IO file
2108 -- is treated directly as a stream using Text_IO.Streams.Stream.
2111 (File : in out Text_AFCB;
2112 Item : Stream_Element_Array)
2114 pragma Warnings (Off, File);
2115 -- Because in this implementation we don't need IN OUT, we only read
2117 function Has_Translated_Characters return Boolean;
2118 -- return True if Item array contains a character which will be
2119 -- translated under the text file mode. There is only one such
2120 -- character under DOS based systems which is character 10.
2122 text_translation_required : Boolean;
2123 for text_translation_required'Size use Character'Size;
2124 pragma Import (C, text_translation_required,
2125 "__gnat_text_translation_required");
2127 Siz : constant size_t := Item'Length;
2129 -------------------------------
2130 -- Has_Translated_Characters --
2131 -------------------------------
2133 function Has_Translated_Characters return Boolean is
2135 for K in Item'Range loop
2136 if Item (K) = 10 then
2141 end Has_Translated_Characters;
2143 Needs_Binary_Write : constant Boolean :=
2144 text_translation_required
2145 and then Has_Translated_Characters;
2147 -- Start of processing for Write
2150 if File.Mode = FCB.In_File then
2154 -- Now we do the write. Since this is a text file, it is normally in
2155 -- text mode, but stream data must be written in binary mode, so we
2156 -- temporarily set binary mode for the write, resetting it after. This
2157 -- is done only if needed (i.e. there is some characters in Item which
2158 -- needs to be written using the binary mode).
2159 -- These calls have no effect in a system (like Unix) where there is
2160 -- no distinction between text and binary files.
2162 -- Since the character translation is done at the time the buffer is
2163 -- written (this is true under Windows) we first flush current buffer
2164 -- with text mode if needed.
2166 if Needs_Binary_Write then
2167 if fflush (File.Stream) = -1 then
2171 set_binary_mode (fileno (File.Stream));
2174 if fwrite (Item'Address, 1, Siz, File.Stream) /= Siz then
2178 -- At this point we need to flush the buffer using the binary mode then
2179 -- we reset to text mode.
2181 if Needs_Binary_Write then
2182 if fflush (File.Stream) = -1 then
2186 set_text_mode (fileno (File.Stream));
2191 -- Initialize Standard Files
2193 for J in WC_Encoding_Method loop
2194 if WC_Encoding = WC_Encoding_Letters (J) then
2199 Initialize_Standard_Files;
2201 FIO.Chain_File (AP (Standard_In));
2202 FIO.Chain_File (AP (Standard_Out));
2203 FIO.Chain_File (AP (Standard_Err));