1------------------------------------------------------------------------------
2--                                                                          --
3--                         GNAT COMPILER COMPONENTS                         --
4--                                                                          --
5--                               O U T P U T                                --
6--                                                                          --
7--                                 S p e c                                  --
8--                                                                          --
9--          Copyright (C) 1992-2001 Free Software Foundation, Inc.          --
10--                                                                          --
11-- GNAT is free software;  you can  redistribute it  and/or modify it under --
12-- terms of the  GNU General Public License as published  by the Free Soft- --
13-- ware  Foundation;  either version 2,  or (at your option) any later ver- --
14-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
15-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
16-- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
17-- for  more details.  You should have  received  a copy of the GNU General --
18-- Public License  distributed with GNAT;  see file COPYING.  If not, write --
19-- to  the Free Software Foundation,  59 Temple Place - Suite 330,  Boston, --
20-- MA 02111-1307, USA.                                                      --
21--                                                                          --
22-- As a special exception,  if other files  instantiate  generics from this --
23-- unit, or you link  this unit with other files  to produce an executable, --
24-- this  unit  does not  by itself cause  the resulting  executable  to  be --
25-- covered  by the  GNU  General  Public  License.  This exception does not --
26-- however invalidate  any other reasons why  the executable file  might be --
27-- covered by the  GNU Public License.                                      --
28--                                                                          --
29-- GNAT was originally developed  by the GNAT team at  New York University. --
30-- Extensive contributions were provided by Ada Core Technologies Inc.      --
31--                                                                          --
32------------------------------------------------------------------------------
33
34--  This package contains low level output routines used by the compiler
35--  for writing error messages and informational output. It is also used
36--  by the debug source file output routines (see Sprintf.Print_Eol).
37
38with Types; use Types;
39
40package Output is
41pragma Elaborate_Body (Output);
42
43   type Output_Proc is access procedure (S : String);
44   --  This type is used for the Set_Special_Output procedure. If this
45   --  procedure is called, then instead of lines being written to
46   --  standard error or standard output, a call is made to the given
47   --  procedure for each line, passing the line with an end of line
48   --  character (which is a single ASCII.LF character, even in systems
49   --  which normally use CR/LF or some other sequence for line end).
50
51   -----------------
52   -- Subprograms --
53   -----------------
54
55   procedure Set_Special_Output (P : Output_Proc);
56   --  Sets subsequent output to call procedure P. If P is null, then
57   --  the call cancels the effect of a previous call, reverting the
58   --  output to standard error or standard output depending on the
59   --  mode at the time of previous call. Any exception generated by
60   --  by calls to P is simply propagated to the caller of the routine
61   --  causing the write operation.
62
63   procedure Cancel_Special_Output;
64   --  Cancels the effect of a call to Set_Special_Output, if any.
65   --  The output is then directed to standard error or standard output
66   --  depending on the last call to Set_Standard_Error or Set_Standard_Output.
67   --  It is never an error to call Cancel_Special_Output. It has the same
68   --  effect as calling Set_Special_Output (null).
69
70   procedure Set_Standard_Error;
71   --  Sets subsequent output to appear on the standard error file (whatever
72   --  that might mean for the host operating system, if anything) when
73   --  no special output is in effect. When a special output is in effect,
74   --  the output will appear on standard error only after special output
75   --  has been cancelled.
76
77   procedure Set_Standard_Output;
78   --  Sets subsequent output to appear on the standard output file (whatever
79   --  that might mean for the host operating system, if anything) when
80   --  no special output is in effect. When a special output is in effect,
81   --  the output will appear on standard output only after special output
82   --  has been cancelled. Output to standard output is the default mode
83   --  before any call to either of the Set procedures.
84
85   procedure Write_Char (C : Character);
86   --  Write one character to the standard output file. Note that the
87   --  character should not be LF or CR (use Write_Eol for end of line)
88
89   procedure Write_Eol;
90   --  Write an end of line (whatever is required by the system in use,
91   --  e.g. CR/LF for DOS, or LF for Unix) to the standard output file.
92   --  This routine also empties the line buffer, actually writing it
93   --  to the file. Note that Write_Eol is the only routine that causes
94   --  any actual output to be written.
95
96   procedure Write_Int (Val : Int);
97   --  Write an integer value with no leading blanks or zeroes. Negative
98   --  values are preceded by a minus sign).
99
100   procedure Write_Str (S : String);
101   --  Write a string of characters to the standard output file. Note that
102   --  end of line is handled separately using WRITE_EOL, so the string
103   --  should not contain either of the characters LF or CR, but it may
104   --  contain horizontal tab characters.
105
106   procedure Write_Line (S : String);
107   --  Equivalent to Write_Str (S) followed by Write_Eol;
108
109   function Column return Nat;
110   pragma Inline (Column);
111   --  Returns the number of the column about to be written (e.g. a value
112   --  of 1 means the current line is empty).
113
114   --------------------------
115   -- Debugging Procedures --
116   --------------------------
117
118   --  The following procedures are intended only for debugging purposes,
119   --  for temporary insertion into the text in environments where a debugger
120   --  is not available. They all have non-standard very short lower case
121   --  names, precisely to make sure that they are only used for debugging!
122
123   procedure w (C : Character);
124   --  Dump quote, character quote, followed by line return
125
126   procedure w (S : String);
127   --  Dump string followed by line return
128
129   procedure w (V : Int);
130   --  Dump integer followed by line return
131
132   procedure w (B : Boolean);
133   --  Dump Boolean followed by line return
134
135   procedure w (L : String; C : Character);
136   --  Dump contents of string followed by blank, quote, character, quote
137
138   procedure w (L : String; S : String);
139   --  Dump two strings separated by blanks, followed by line return
140
141   procedure w (L : String; V : Int);
142   --  Dump contents of string followed by blank, integer, line return
143
144   procedure w (L : String; B : Boolean);
145   --  Dump contents of string followed by blank, Boolean, line return
146
147end Output;
148