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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- O U T P U T --
-- --
-- S p e c --
-- --
-- Copyright (C) 1992-2021, 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 3, 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 COPYING3. If not, go to --
-- http://www.gnu.org/licenses for a complete copy of the license. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
-- This package contains low level output routines used by the compiler for
-- writing error messages and informational output. It is also used by the
-- debug source file output routines (see Sprint.Print_Debug_Line).
with Hostparm;
with Types; use Types;
pragma Warnings (Off);
-- This package is used also by gnatcoll
with System.OS_Lib; use System.OS_Lib;
pragma Warnings (On);
package Output is
pragma Elaborate_Body;
type Output_Proc is access procedure (S : String);
-- This type is used for the Set_Special_Output procedure. If Output_Proc
-- is called, then instead of lines being written to standard error or
-- standard output, a call is made to the given procedure for each line,
-- passing the line with an end of line character (which is a single
-- ASCII.LF character, even in systems which normally use CR/LF or some
-- other sequence for line end).
-----------------
-- Subprograms --
-----------------
procedure Set_Special_Output (P : Output_Proc);
-- Sets subsequent output to call procedure P. If P is null, then the call
-- cancels the effect of a previous call, reverting the output to standard
-- error or standard output depending on the mode at the time of previous
-- call. Any exception generated by calls to P is simply propagated to
-- the caller of the routine causing the write operation.
procedure Cancel_Special_Output;
-- Cancels the effect of a call to Set_Special_Output, if any. The output
-- is then directed to standard error or standard output depending on the
-- last call to Set_Standard_Error or Set_Standard_Output. It is never an
-- error to call Cancel_Special_Output. It has the same effect as calling
-- Set_Special_Output (null).
procedure Ignore_Output (S : String);
-- Does nothing. To disable output, pass Ignore_Output'Access to
-- Set_Special_Output.
procedure Set_Standard_Error;
-- Sets subsequent output to appear on the standard error file (whatever
-- that might mean for the host operating system, if anything) when
-- no special output is in effect. When a special output is in effect,
-- the output will appear on standard error only after special output
-- has been cancelled.
procedure Set_Standard_Output;
-- Sets subsequent output to appear on the standard output file (whatever
-- that might mean for the host operating system, if anything) when no
-- special output is in effect. When a special output is in effect, the
-- output will appear on standard output only after special output has been
-- cancelled. Output to standard output is the default mode before any call
-- to either of the Set procedures.
procedure Set_Output (FD : File_Descriptor);
-- Sets subsequent output to appear on the given file descriptor when no
-- special output is in effect. When a special output is in effect, the
-- output will appear on the given file descriptor only after special
-- output has been cancelled.
procedure Push_Output;
-- Saves the current output destination on a stack, but leaves it
-- unchanged. This subprogram only supports a small stack and is normally
-- used with a depth of one.
procedure Pop_Output;
-- Changes the current output destination to be the last output destination
-- popped using Push_Output.
procedure Indent;
-- Increases the current indentation level. Whenever a line is written
-- (triggered by Eol), an appropriate amount of whitespace is added to the
-- beginning of the line, wrapping around if it gets too long.
procedure Outdent;
-- Decreases the current indentation level
procedure Write_Char (C : Character);
-- Write one character to the standard output file. If the character is LF,
-- this is equivalent to Write_Eol.
procedure Write_Erase_Char (C : Character);
-- If last character in buffer matches C, erase it, otherwise no effect
procedure Write_Eol;
-- Write an end of line (whatever is required by the system in use, e.g.
-- CR/LF for DOS, or LF for Unix) to the standard output file. This routine
-- also empties the line buffer, actually writing it to the file. Note that
-- Write_Eol is the only routine that causes any actual output to be
-- written. Trailing spaces are removed.
procedure Write_Eol_Keep_Blanks;
-- Similar as Write_Eol, except that trailing spaces are not removed
procedure Write_Int (Val : Int);
-- Write an integer value with no leading blanks or zeroes. Negative values
-- are preceded by a minus sign).
procedure Write_Spaces (N : Nat);
-- Write N spaces
procedure Write_Str (S : String);
-- Write a string of characters to the standard output file. Note that
-- end of line is normally handled separately using WRITE_EOL, but it is
-- allowable for the string to contain LF (but not CR) characters, which
-- are properly interpreted as end of line characters. The string may also
-- contain horizontal tab characters.
procedure Write_Line (S : String);
-- Equivalent to Write_Str (S) followed by Write_Eol;
function Last_Char return Character;
-- Returns last character written on the current line, or null if the
-- current line is (so far) empty.
procedure Delete_Last_Char;
-- Deletes last character written on the current line, no effect if the
-- current line is (so far) empty.
function Column return Pos;
pragma Inline (Column);
-- Returns the number of the column about to be written (e.g. a value of 1
-- means the current line is empty).
-------------------------
-- Buffer Save/Restore --
-------------------------
-- This facility allows the current line buffer to be saved and restored
type Saved_Output_Buffer is private;
-- Type used for Save/Restore_Buffer
Buffer_Max : constant := Hostparm.Max_Line_Length;
-- Maximal size of a buffered output line
function Save_Output_Buffer return Saved_Output_Buffer;
-- Save current line buffer and reset line buffer to empty
procedure Restore_Output_Buffer (S : Saved_Output_Buffer);
-- Restore previously saved output buffer. The value in S is not affected
-- so it is legitimate to restore a buffer more than once.
--------------------------
-- Debugging Procedures --
--------------------------
-- The following procedures are intended only for debugging purposes,
-- for temporary insertion into the text in environments where a debugger
-- is not available. They all have non-standard very short lower case
-- names, precisely to make sure that they are only used for debugging.
procedure w (C : Character);
-- Dump quote, character, quote, followed by line return
procedure w (S : String);
-- Dump string followed by line return
procedure w (V : Int);
-- Dump integer followed by line return
procedure w (B : Boolean);
-- Dump Boolean followed by line return
procedure w (L : String; C : Character);
-- Dump contents of string followed by blank, quote, character, quote
procedure w (L : String; S : String);
-- Dump two strings separated by blanks, followed by line return
procedure w (L : String; V : Int);
-- Dump contents of string followed by blank, integer, line return
procedure w (L : String; B : Boolean);
-- Dump contents of string followed by blank, Boolean, line return
private
type Saved_Output_Buffer is record
Buffer : String (1 .. Buffer_Max + 1);
Next_Col : Positive;
Cur_Indentation : Natural;
end record;
end Output;
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