| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT RUN-TIME COMPONENTS -- |
| -- -- |
| -- S Y S T E M . F I L E _ I O -- |
| -- -- |
| -- B o d y -- |
| -- -- |
| -- Copyright (C) 1992-2003 Free Software Foundation, Inc. -- |
| -- -- |
| -- GNAT is free software; you can redistribute it and/or modify it under -- |
| -- terms of the GNU General Public License as published by the Free Soft- -- |
| -- ware Foundation; either version 2, or (at your option) any later ver- -- |
| -- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- |
| -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- |
| -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- |
| -- for more details. You should have received a copy of the GNU General -- |
| -- Public License distributed with GNAT; see file COPYING. If not, write -- |
| -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, -- |
| -- MA 02111-1307, USA. -- |
| -- -- |
| -- As a special exception, if other files instantiate generics from this -- |
| -- unit, or you link this unit with other files to produce an executable, -- |
| -- this unit does not by itself cause the resulting executable to be -- |
| -- covered by the GNU General Public License. This exception does not -- |
| -- however invalidate any other reasons why the executable file might be -- |
| -- covered by the GNU Public License. -- |
| -- -- |
| -- GNAT was originally developed by the GNAT team at New York University. -- |
| -- Extensive contributions were provided by Ada Core Technologies Inc. -- |
| -- -- |
| ------------------------------------------------------------------------------ |
| |
| with Ada.Finalization; use Ada.Finalization; |
| with Ada.IO_Exceptions; use Ada.IO_Exceptions; |
| with Interfaces.C_Streams; use Interfaces.C_Streams; |
| with System.CRTL; |
| with System.Soft_Links; |
| with Unchecked_Deallocation; |
| |
| package body System.File_IO is |
| |
| use System.File_Control_Block; |
| |
| package SSL renames System.Soft_Links; |
| |
| use type System.CRTL.size_t; |
| |
| ---------------------- |
| -- Global Variables -- |
| ---------------------- |
| |
| Open_Files : AFCB_Ptr; |
| -- This points to a list of AFCB's for all open files. This is a doubly |
| -- linked list, with the Prev pointer of the first entry, and the Next |
| -- pointer of the last entry containing null. Note that this global |
| -- variable must be properly protected to provide thread safety. |
| |
| type Temp_File_Record; |
| type Temp_File_Record_Ptr is access all Temp_File_Record; |
| |
| type Temp_File_Record is record |
| Name : String (1 .. L_tmpnam + 1); |
| Next : Temp_File_Record_Ptr; |
| end record; |
| -- One of these is allocated for each temporary file created |
| |
| Temp_Files : Temp_File_Record_Ptr; |
| -- Points to list of names of temporary files. Note that this global |
| -- variable must be properly protected to provide thread safety. |
| |
| type File_IO_Clean_Up_Type is new Controlled with null record; |
| -- The closing of all open files and deletion of temporary files is an |
| -- action which takes place at the end of execution of the main program. |
| -- This action can be implemented using a library level object which |
| -- gets finalized at the end of the main program execution. The above is |
| -- a controlled type introduced for this purpose. |
| |
| procedure Finalize (V : in out File_IO_Clean_Up_Type); |
| -- This is the finalize operation that is used to do the cleanup. |
| |
| File_IO_Clean_Up_Object : File_IO_Clean_Up_Type; |
| pragma Warnings (Off, File_IO_Clean_Up_Object); |
| -- This is the single object of the type that triggers the finalization |
| -- call. Since it is at the library level, this happens just before the |
| -- environment task is finalized. |
| |
| text_translation_required : Boolean; |
| pragma Import |
| (C, text_translation_required, "__gnat_text_translation_required"); |
| -- If true, add appropriate suffix to control string for Open. |
| |
| ----------------------- |
| -- Local Subprograms -- |
| ----------------------- |
| |
| procedure Free_String is new Unchecked_Deallocation (String, Pstring); |
| |
| subtype Fopen_String is String (1 .. 4); |
| -- Holds open string (longest is "w+b" & nul) |
| |
| procedure Fopen_Mode |
| (Mode : File_Mode; |
| Text : Boolean; |
| Creat : Boolean; |
| Amethod : Character; |
| Fopstr : out Fopen_String); |
| -- Determines proper open mode for a file to be opened in the given |
| -- Ada mode. Text is true for a text file and false otherwise, and |
| -- Creat is true for a create call, and False for an open call. The |
| -- value stored in Fopstr is a nul-terminated string suitable for a |
| -- call to fopen or freopen. Amethod is the character designating |
| -- the access method from the Access_Method field of the FCB. |
| |
| ---------------- |
| -- Append_Set -- |
| ---------------- |
| |
| procedure Append_Set (File : AFCB_Ptr) is |
| begin |
| if File.Mode = Append_File then |
| if fseek (File.Stream, 0, SEEK_END) /= 0 then |
| raise Device_Error; |
| end if; |
| end if; |
| end Append_Set; |
| |
| ---------------- |
| -- Chain_File -- |
| ---------------- |
| |
| procedure Chain_File (File : AFCB_Ptr) is |
| begin |
| -- Take a task lock, to protect the global data value Open_Files |
| |
| SSL.Lock_Task.all; |
| |
| -- Do the chaining operation locked |
| |
| File.Next := Open_Files; |
| File.Prev := null; |
| Open_Files := File; |
| |
| if File.Next /= null then |
| File.Next.Prev := File; |
| end if; |
| |
| SSL.Unlock_Task.all; |
| |
| exception |
| when others => |
| SSL.Unlock_Task.all; |
| raise; |
| end Chain_File; |
| |
| --------------------- |
| -- Check_File_Open -- |
| --------------------- |
| |
| procedure Check_File_Open (File : AFCB_Ptr) is |
| begin |
| if File = null then |
| raise Status_Error; |
| end if; |
| end Check_File_Open; |
| |
| ----------------------- |
| -- Check_Read_Status -- |
| ----------------------- |
| |
| procedure Check_Read_Status (File : AFCB_Ptr) is |
| begin |
| if File = null then |
| raise Status_Error; |
| elsif File.Mode > Inout_File then |
| raise Mode_Error; |
| end if; |
| end Check_Read_Status; |
| |
| ------------------------ |
| -- Check_Write_Status -- |
| ------------------------ |
| |
| procedure Check_Write_Status (File : AFCB_Ptr) is |
| begin |
| if File = null then |
| raise Status_Error; |
| elsif File.Mode = In_File then |
| raise Mode_Error; |
| end if; |
| end Check_Write_Status; |
| |
| ----------- |
| -- Close -- |
| ----------- |
| |
| procedure Close (File : in out AFCB_Ptr) is |
| Close_Status : int := 0; |
| Dup_Strm : Boolean := False; |
| |
| begin |
| Check_File_Open (File); |
| AFCB_Close (File); |
| |
| -- Take a task lock, to protect the global data value Open_Files |
| |
| SSL.Lock_Task.all; |
| |
| -- Sever the association between the given file and its associated |
| -- external file. The given file is left closed. Do not perform system |
| -- closes on the standard input, output and error files and also do |
| -- not attempt to close a stream that does not exist (signalled by a |
| -- null stream value -- happens in some error situations). |
| |
| if not File.Is_System_File |
| and then File.Stream /= NULL_Stream |
| then |
| -- Do not do an fclose if this is a shared file and there is |
| -- at least one other instance of the stream that is open. |
| |
| if File.Shared_Status = Yes then |
| declare |
| P : AFCB_Ptr; |
| |
| begin |
| P := Open_Files; |
| while P /= null loop |
| if P /= File |
| and then File.Stream = P.Stream |
| then |
| Dup_Strm := True; |
| exit; |
| end if; |
| |
| P := P.Next; |
| end loop; |
| end; |
| end if; |
| |
| -- Do the fclose unless this was a duplicate in the shared case |
| |
| if not Dup_Strm then |
| Close_Status := fclose (File.Stream); |
| end if; |
| end if; |
| |
| -- Dechain file from list of open files and then free the storage |
| |
| if File.Prev = null then |
| Open_Files := File.Next; |
| else |
| File.Prev.Next := File.Next; |
| end if; |
| |
| if File.Next /= null then |
| File.Next.Prev := File.Prev; |
| end if; |
| |
| -- Deallocate some parts of the file structure that were kept in heap |
| -- storage with the exception of system files (standard input, output |
| -- and error) since they had some information allocated in the stack. |
| |
| if not File.Is_System_File then |
| Free_String (File.Name); |
| Free_String (File.Form); |
| AFCB_Free (File); |
| end if; |
| |
| File := null; |
| |
| if Close_Status /= 0 then |
| raise Device_Error; |
| end if; |
| |
| SSL.Unlock_Task.all; |
| |
| exception |
| when others => |
| SSL.Unlock_Task.all; |
| raise; |
| end Close; |
| |
| ------------ |
| -- Delete -- |
| ------------ |
| |
| procedure Delete (File : in out AFCB_Ptr) is |
| begin |
| Check_File_Open (File); |
| |
| if not File.Is_Regular_File then |
| raise Use_Error; |
| end if; |
| |
| declare |
| Filename : aliased constant String := File.Name.all; |
| |
| begin |
| Close (File); |
| |
| -- Now unlink the external file. Note that we use the full name |
| -- in this unlink, because the working directory may have changed |
| -- since we did the open, and we want to unlink the right file! |
| |
| if unlink (Filename'Address) = -1 then |
| raise Use_Error; |
| end if; |
| end; |
| end Delete; |
| |
| ----------------- |
| -- End_Of_File -- |
| ----------------- |
| |
| function End_Of_File (File : AFCB_Ptr) return Boolean is |
| begin |
| Check_File_Open (File); |
| |
| if feof (File.Stream) /= 0 then |
| return True; |
| |
| else |
| Check_Read_Status (File); |
| |
| if ungetc (fgetc (File.Stream), File.Stream) = EOF then |
| clearerr (File.Stream); |
| return True; |
| else |
| return False; |
| end if; |
| end if; |
| end End_Of_File; |
| |
| -------------- |
| -- Finalize -- |
| -------------- |
| |
| -- Note: we do not need to worry about locking against multiple task |
| -- access in this routine, since it is called only from the environment |
| -- task just before terminating execution. |
| |
| procedure Finalize (V : in out File_IO_Clean_Up_Type) is |
| pragma Warnings (Off, V); |
| |
| Fptr1 : AFCB_Ptr; |
| Fptr2 : AFCB_Ptr; |
| |
| Discard : int; |
| pragma Unreferenced (Discard); |
| |
| begin |
| -- Take a lock to protect global Open_Files data structure |
| |
| SSL.Lock_Task.all; |
| |
| -- First close all open files (the slightly complex form of this loop |
| -- is required because Close as a side effect nulls out its argument) |
| |
| Fptr1 := Open_Files; |
| while Fptr1 /= null loop |
| Fptr2 := Fptr1.Next; |
| Close (Fptr1); |
| Fptr1 := Fptr2; |
| end loop; |
| |
| -- Now unlink all temporary files. We do not bother to free the |
| -- blocks because we are just about to terminate the program. We |
| -- also ignore any errors while attempting these unlink operations. |
| |
| while Temp_Files /= null loop |
| Discard := unlink (Temp_Files.Name'Address); |
| Temp_Files := Temp_Files.Next; |
| end loop; |
| |
| SSL.Unlock_Task.all; |
| |
| exception |
| when others => |
| SSL.Unlock_Task.all; |
| raise; |
| end Finalize; |
| |
| ----------- |
| -- Flush -- |
| ----------- |
| |
| procedure Flush (File : AFCB_Ptr) is |
| begin |
| Check_Write_Status (File); |
| |
| if fflush (File.Stream) = 0 then |
| return; |
| else |
| raise Device_Error; |
| end if; |
| end Flush; |
| |
| ---------------- |
| -- Fopen_Mode -- |
| ---------------- |
| |
| -- The fopen mode to be used is shown by the following table: |
| |
| -- OPEN CREATE |
| -- Append_File "r+" "w+" |
| -- In_File "r" "w+" |
| -- Out_File (Direct_IO) "r+" "w" |
| -- Out_File (all others) "w" "w" |
| -- Inout_File "r+" "w+" |
| |
| -- Note: we do not use "a" or "a+" for Append_File, since this would not |
| -- work in the case of stream files, where even if in append file mode, |
| -- you can reset to earlier points in the file. The caller must use the |
| -- Append_Set routine to deal with the necessary positioning. |
| |
| -- Note: in several cases, the fopen mode used allows reading and |
| -- writing, but the setting of the Ada mode is more restrictive. For |
| -- instance, Create in In_File mode uses "w+" which allows writing, |
| -- but the Ada mode In_File will cause any write operations to be |
| -- rejected with Mode_Error in any case. |
| |
| -- Note: for the Out_File/Open cases for other than the Direct_IO case, |
| -- an initial call will be made by the caller to first open the file in |
| -- "r" mode to be sure that it exists. The real open, in "w" mode, will |
| -- then destroy this file. This is peculiar, but that's what Ada semantics |
| -- require and the ACVT tests insist on! |
| |
| -- If text file translation is required, then either b or t is |
| -- added to the mode, depending on the setting of Text. |
| |
| procedure Fopen_Mode |
| (Mode : File_Mode; |
| Text : Boolean; |
| Creat : Boolean; |
| Amethod : Character; |
| Fopstr : out Fopen_String) |
| is |
| Fptr : Positive; |
| |
| begin |
| case Mode is |
| when In_File => |
| if Creat then |
| Fopstr (1) := 'w'; |
| Fopstr (2) := '+'; |
| Fptr := 3; |
| else |
| Fopstr (1) := 'r'; |
| Fptr := 2; |
| end if; |
| |
| when Out_File => |
| if Amethod = 'D' and not Creat then |
| Fopstr (1) := 'r'; |
| Fopstr (2) := '+'; |
| Fptr := 3; |
| else |
| Fopstr (1) := 'w'; |
| Fptr := 2; |
| end if; |
| |
| when Inout_File | Append_File => |
| if Creat then |
| Fopstr (1) := 'w'; |
| else |
| Fopstr (1) := 'r'; |
| end if; |
| |
| Fopstr (2) := '+'; |
| Fptr := 3; |
| |
| end case; |
| |
| -- If text_translation_required is true then we need to append |
| -- either a t or b to the string to get the right mode |
| |
| if text_translation_required then |
| if Text then |
| Fopstr (Fptr) := 't'; |
| else |
| Fopstr (Fptr) := 'b'; |
| end if; |
| |
| Fptr := Fptr + 1; |
| end if; |
| |
| Fopstr (Fptr) := ASCII.NUL; |
| end Fopen_Mode; |
| |
| ---------- |
| -- Form -- |
| ---------- |
| |
| function Form (File : in AFCB_Ptr) return String is |
| begin |
| if File = null then |
| raise Status_Error; |
| else |
| return File.Form.all (1 .. File.Form'Length - 1); |
| end if; |
| end Form; |
| |
| ------------------ |
| -- Form_Boolean -- |
| ------------------ |
| |
| function Form_Boolean |
| (Form : String; |
| Keyword : String; |
| Default : Boolean) |
| return Boolean |
| is |
| V1, V2 : Natural; |
| |
| begin |
| Form_Parameter (Form, Keyword, V1, V2); |
| |
| if V1 = 0 then |
| return Default; |
| |
| elsif Form (V1) = 'y' then |
| return True; |
| |
| elsif Form (V1) = 'n' then |
| return False; |
| |
| else |
| raise Use_Error; |
| end if; |
| end Form_Boolean; |
| |
| ------------------ |
| -- Form_Integer -- |
| ------------------ |
| |
| function Form_Integer |
| (Form : String; |
| Keyword : String; |
| Default : Integer) |
| return Integer |
| is |
| V1, V2 : Natural; |
| V : Integer; |
| |
| begin |
| Form_Parameter (Form, Keyword, V1, V2); |
| |
| if V1 = 0 then |
| return Default; |
| |
| else |
| V := 0; |
| |
| for J in V1 .. V2 loop |
| if Form (J) not in '0' .. '9' then |
| raise Use_Error; |
| else |
| V := V * 10 + Character'Pos (Form (J)) - Character'Pos ('0'); |
| end if; |
| |
| if V > 999_999 then |
| raise Use_Error; |
| end if; |
| end loop; |
| |
| return V; |
| end if; |
| end Form_Integer; |
| |
| -------------------- |
| -- Form_Parameter -- |
| -------------------- |
| |
| procedure Form_Parameter |
| (Form : String; |
| Keyword : String; |
| Start : out Natural; |
| Stop : out Natural) |
| is |
| Klen : constant Integer := Keyword'Length; |
| |
| -- Start of processing for Form_Parameter |
| |
| begin |
| for J in Form'First + Klen .. Form'Last - 1 loop |
| if Form (J) = '=' |
| and then Form (J - Klen .. J - 1) = Keyword |
| then |
| Start := J + 1; |
| Stop := Start - 1; |
| |
| while Form (Stop + 1) /= ASCII.NUL |
| and then Form (Stop + 1) /= ',' |
| loop |
| Stop := Stop + 1; |
| end loop; |
| |
| return; |
| end if; |
| end loop; |
| |
| Start := 0; |
| Stop := 0; |
| end Form_Parameter; |
| |
| ------------- |
| -- Is_Open -- |
| ------------- |
| |
| function Is_Open (File : in AFCB_Ptr) return Boolean is |
| begin |
| return (File /= null); |
| end Is_Open; |
| |
| ------------------- |
| -- Make_Buffered -- |
| ------------------- |
| |
| procedure Make_Buffered |
| (File : AFCB_Ptr; |
| Buf_Siz : Interfaces.C_Streams.size_t) |
| is |
| status : Integer; |
| pragma Unreferenced (status); |
| |
| begin |
| status := setvbuf (File.Stream, Null_Address, IOFBF, Buf_Siz); |
| end Make_Buffered; |
| |
| ------------------------ |
| -- Make_Line_Buffered -- |
| ------------------------ |
| |
| procedure Make_Line_Buffered |
| (File : AFCB_Ptr; |
| Line_Siz : Interfaces.C_Streams.size_t) |
| is |
| status : Integer; |
| pragma Unreferenced (status); |
| |
| begin |
| status := setvbuf (File.Stream, Null_Address, IOLBF, Line_Siz); |
| end Make_Line_Buffered; |
| |
| --------------------- |
| -- Make_Unbuffered -- |
| --------------------- |
| |
| procedure Make_Unbuffered (File : AFCB_Ptr) is |
| status : Integer; |
| pragma Unreferenced (status); |
| |
| begin |
| status := setvbuf (File.Stream, Null_Address, IONBF, 0); |
| end Make_Unbuffered; |
| |
| ---------- |
| -- Mode -- |
| ---------- |
| |
| function Mode (File : in AFCB_Ptr) return File_Mode is |
| begin |
| if File = null then |
| raise Status_Error; |
| else |
| return File.Mode; |
| end if; |
| end Mode; |
| |
| ---------- |
| -- Name -- |
| ---------- |
| |
| function Name (File : in AFCB_Ptr) return String is |
| begin |
| if File = null then |
| raise Status_Error; |
| else |
| return File.Name.all (1 .. File.Name'Length - 1); |
| end if; |
| end Name; |
| |
| ---------- |
| -- Open -- |
| ---------- |
| |
| procedure Open |
| (File_Ptr : in out AFCB_Ptr; |
| Dummy_FCB : in AFCB'Class; |
| Mode : File_Mode; |
| Name : String; |
| Form : String; |
| Amethod : Character; |
| Creat : Boolean; |
| Text : Boolean; |
| C_Stream : FILEs := NULL_Stream) |
| is |
| pragma Warnings (Off, Dummy_FCB); |
| -- Yes we know this is never assigned a value. That's intended, since |
| -- all we ever use of this value is the tag for dispatching purposes. |
| |
| procedure Tmp_Name (Buffer : Address); |
| pragma Import (C, Tmp_Name, "__gnat_tmp_name"); |
| -- set buffer (a String address) with a temporary filename. |
| |
| Stream : FILEs := C_Stream; |
| -- Stream which we open in response to this request |
| |
| Shared : Shared_Status_Type; |
| -- Setting of Shared_Status field for file |
| |
| Fopstr : aliased Fopen_String; |
| -- Mode string used in fopen call |
| |
| Formstr : aliased String (1 .. Form'Length + 1); |
| -- Form string with ASCII.NUL appended, folded to lower case |
| |
| Tempfile : constant Boolean := (Name'Length = 0); |
| -- Indicates temporary file case |
| |
| Namelen : constant Integer := max_path_len; |
| -- Length required for file name, not including final ASCII.NUL |
| -- Note that we used to reference L_tmpnam here, which is not |
| -- reliable since __gnat_tmp_name does not always use tmpnam. |
| |
| Namestr : aliased String (1 .. Namelen + 1); |
| -- Name as given or temporary file name with ASCII.NUL appended |
| |
| Fullname : aliased String (1 .. max_path_len + 1); |
| -- Full name (as required for Name function, and as stored in the |
| -- control block in the Name field) with ASCII.NUL appended. |
| |
| Full_Name_Len : Integer; |
| -- Length of name actually stored in Fullname |
| |
| begin |
| if File_Ptr /= null then |
| raise Status_Error; |
| end if; |
| |
| -- Acquire form string, setting required NUL terminator |
| |
| Formstr (1 .. Form'Length) := Form; |
| Formstr (Formstr'Last) := ASCII.NUL; |
| |
| -- Convert form string to lower case |
| |
| for J in Formstr'Range loop |
| if Formstr (J) in 'A' .. 'Z' then |
| Formstr (J) := Character'Val (Character'Pos (Formstr (J)) + 32); |
| end if; |
| end loop; |
| |
| -- Acquire setting of shared parameter |
| |
| declare |
| V1, V2 : Natural; |
| |
| begin |
| Form_Parameter (Formstr, "shared", V1, V2); |
| |
| if V1 = 0 then |
| Shared := None; |
| |
| elsif Formstr (V1 .. V2) = "yes" then |
| Shared := Yes; |
| |
| elsif Formstr (V1 .. V2) = "no" then |
| Shared := No; |
| |
| else |
| raise Use_Error; |
| end if; |
| end; |
| |
| -- If we were given a stream (call from xxx.C_Streams.Open), then set |
| -- full name to null and that is all we have to do in this case so |
| -- skip to end of processing. |
| |
| if Stream /= NULL_Stream then |
| Fullname (1) := ASCII.Nul; |
| Full_Name_Len := 1; |
| |
| -- Normal case of Open or Create |
| |
| else |
| -- If temporary file case, get temporary file name and add |
| -- to the list of temporary files to be deleted on exit. |
| |
| if Tempfile then |
| if not Creat then |
| raise Name_Error; |
| end if; |
| |
| Tmp_Name (Namestr'Address); |
| |
| if Namestr (1) = ASCII.NUL then |
| raise Use_Error; |
| end if; |
| |
| -- Chain to temp file list, ensuring thread safety with a lock |
| |
| begin |
| SSL.Lock_Task.all; |
| Temp_Files := |
| new Temp_File_Record'(Name => Namestr, Next => Temp_Files); |
| SSL.Unlock_Task.all; |
| |
| exception |
| when others => |
| SSL.Unlock_Task.all; |
| raise; |
| end; |
| |
| -- Normal case of non-null name given |
| |
| else |
| if Name'Length > Namelen then |
| raise Name_Error; |
| end if; |
| |
| Namestr (1 .. Name'Length) := Name; |
| Namestr (Name'Length + 1) := ASCII.NUL; |
| end if; |
| |
| -- Get full name in accordance with the advice of RM A.8.2(22). |
| |
| full_name (Namestr'Address, Fullname'Address); |
| |
| if Fullname (1) = ASCII.NUL then |
| raise Use_Error; |
| end if; |
| |
| Full_Name_Len := 1; |
| while Full_Name_Len < Fullname'Last |
| and then Fullname (Full_Name_Len) /= ASCII.NUL |
| loop |
| Full_Name_Len := Full_Name_Len + 1; |
| end loop; |
| |
| -- If Shared=None or Shared=Yes, then check for the existence |
| -- of another file with exactly the same full name. |
| |
| if Shared /= No then |
| declare |
| P : AFCB_Ptr; |
| |
| begin |
| -- Take a task lock to protect Open_Files |
| |
| SSL.Lock_Task.all; |
| |
| -- Search list of open files |
| |
| P := Open_Files; |
| while P /= null loop |
| if Fullname (1 .. Full_Name_Len) = P.Name.all then |
| |
| -- If we get a match, and either file has Shared=None, |
| -- then raise Use_Error, since we don't allow two |
| -- files of the same name to be opened unless they |
| -- specify the required sharing mode. |
| |
| if Shared = None |
| or else P.Shared_Status = None |
| then |
| raise Use_Error; |
| |
| -- If both files have Shared=Yes, then we acquire the |
| -- stream from the located file to use as our stream. |
| |
| elsif Shared = Yes |
| and then P.Shared_Status = Yes |
| then |
| Stream := P.Stream; |
| exit; |
| |
| -- Otherwise one of the files has Shared=Yes and one |
| -- has Shared=No. If the current file has Shared=No |
| -- then all is well but we don't want to share any |
| -- other file's stream. If the current file has |
| -- Shared=Yes, we would like to share a stream, but |
| -- not from a file that has Shared=No, so in either |
| -- case we just keep going on the search. |
| |
| else |
| null; |
| end if; |
| end if; |
| |
| P := P.Next; |
| end loop; |
| |
| SSL.Unlock_Task.all; |
| |
| exception |
| when others => |
| SSL.Unlock_Task.all; |
| raise; |
| end; |
| end if; |
| |
| -- Open specified file if we did not find an existing stream |
| |
| if Stream = NULL_Stream then |
| Fopen_Mode (Mode, Text, Creat, Amethod, Fopstr); |
| |
| -- A special case, if we are opening (OPEN case) a file and |
| -- the mode returned by Fopen_Mode is not "r" or "r+", then |
| -- we first make sure that the file exists as required by |
| -- Ada semantics. |
| |
| if Creat = False and then Fopstr (1) /= 'r' then |
| if file_exists (Namestr'Address) = 0 then |
| raise Name_Error; |
| end if; |
| end if; |
| |
| -- Now open the file. Note that we use the name as given |
| -- in the original Open call for this purpose, since that |
| -- seems the clearest implementation of the intent. It |
| -- would presumably work to use the full name here, but |
| -- if there is any difference, then we should use the |
| -- name used in the call. |
| |
| -- Note: for a corresponding delete, we will use the |
| -- full name, since by the time of the delete, the |
| -- current working directory may have changed and |
| -- we do not want to delete a different file! |
| |
| Stream := fopen (Namestr'Address, Fopstr'Address); |
| |
| if Stream = NULL_Stream then |
| if file_exists (Namestr'Address) = 0 then |
| raise Name_Error; |
| else |
| raise Use_Error; |
| end if; |
| end if; |
| end if; |
| end if; |
| |
| -- Stream has been successfully located or opened, so now we are |
| -- committed to completing the opening of the file. Allocate block |
| -- on heap and fill in its fields. |
| |
| File_Ptr := AFCB_Allocate (Dummy_FCB); |
| |
| File_Ptr.Is_Regular_File := (is_regular_file |
| (fileno (Stream)) /= 0); |
| File_Ptr.Is_System_File := False; |
| File_Ptr.Is_Text_File := Text; |
| File_Ptr.Shared_Status := Shared; |
| File_Ptr.Access_Method := Amethod; |
| File_Ptr.Stream := Stream; |
| File_Ptr.Form := new String'(Formstr); |
| File_Ptr.Name := new String'(Fullname |
| (1 .. Full_Name_Len)); |
| File_Ptr.Mode := Mode; |
| File_Ptr.Is_Temporary_File := Tempfile; |
| |
| Chain_File (File_Ptr); |
| Append_Set (File_Ptr); |
| end Open; |
| |
| -------------- |
| -- Read_Buf -- |
| -------------- |
| |
| procedure Read_Buf (File : AFCB_Ptr; Buf : Address; Siz : size_t) is |
| Nread : size_t; |
| |
| begin |
| Nread := fread (Buf, 1, Siz, File.Stream); |
| |
| if Nread = Siz then |
| return; |
| |
| elsif ferror (File.Stream) /= 0 then |
| raise Device_Error; |
| |
| elsif Nread = 0 then |
| raise End_Error; |
| |
| else -- 0 < Nread < Siz |
| raise Data_Error; |
| end if; |
| |
| end Read_Buf; |
| |
| procedure Read_Buf |
| (File : AFCB_Ptr; |
| Buf : Address; |
| Siz : in Interfaces.C_Streams.size_t; |
| Count : out Interfaces.C_Streams.size_t) |
| is |
| begin |
| Count := fread (Buf, 1, Siz, File.Stream); |
| |
| if Count = 0 and then ferror (File.Stream) /= 0 then |
| raise Device_Error; |
| end if; |
| end Read_Buf; |
| |
| ----------- |
| -- Reset -- |
| ----------- |
| |
| -- The reset which does not change the mode simply does a rewind. |
| |
| procedure Reset (File : in out AFCB_Ptr) is |
| begin |
| Check_File_Open (File); |
| Reset (File, File.Mode); |
| end Reset; |
| |
| -- The reset with a change in mode is done using freopen, and is |
| -- not permitted except for regular files (since otherwise there |
| -- is no name for the freopen, and in any case it seems meaningless) |
| |
| procedure Reset (File : in out AFCB_Ptr; Mode : in File_Mode) is |
| Fopstr : aliased Fopen_String; |
| |
| begin |
| Check_File_Open (File); |
| |
| -- Change of mode not allowed for shared file or file with no name |
| -- or file that is not a regular file, or for a system file. |
| |
| if File.Shared_Status = Yes |
| or else File.Name'Length <= 1 |
| or else File.Is_System_File |
| or else (not File.Is_Regular_File) |
| then |
| raise Use_Error; |
| |
| -- For In_File or Inout_File for a regular file, we can just do a |
| -- rewind if the mode is unchanged, which is more efficient than |
| -- doing a full reopen. |
| |
| elsif Mode = File.Mode |
| and then Mode <= Inout_File |
| then |
| rewind (File.Stream); |
| |
| -- Here the change of mode is permitted, we do it by reopening the |
| -- file in the new mode and replacing the stream with a new stream. |
| |
| else |
| Fopen_Mode |
| (Mode, File.Is_Text_File, False, File.Access_Method, Fopstr); |
| |
| File.Stream := |
| freopen (File.Name.all'Address, Fopstr'Address, File.Stream); |
| |
| if File.Stream = NULL_Stream then |
| Close (File); |
| raise Use_Error; |
| |
| else |
| File.Mode := Mode; |
| Append_Set (File); |
| end if; |
| end if; |
| end Reset; |
| |
| --------------- |
| -- Write_Buf -- |
| --------------- |
| |
| procedure Write_Buf (File : AFCB_Ptr; Buf : Address; Siz : size_t) is |
| begin |
| -- Note: for most purposes, the Siz and 1 parameters in the fwrite |
| -- call could be reversed, but on VMS, this is a better choice, since |
| -- for some file formats, reversing the parameters results in records |
| -- of one byte each. |
| |
| SSL.Abort_Defer.all; |
| |
| if fwrite (Buf, Siz, 1, File.Stream) /= 1 then |
| if Siz /= 0 then |
| SSL.Abort_Undefer.all; |
| raise Device_Error; |
| end if; |
| end if; |
| |
| SSL.Abort_Undefer.all; |
| end Write_Buf; |
| |
| end System.File_IO; |
