1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2020, 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. 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 COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 -- This package contains low level output routines used by the compiler for
27 -- writing error messages and informational output. It is also used by the
28 -- debug source file output routines (see Sprint.Print_Debug_Line).
31 with Types
; use Types
;
33 pragma Warnings
(Off
);
34 -- This package is used also by gnatcoll
35 with System
.OS_Lib
; use System
.OS_Lib
;
39 pragma Elaborate_Body
;
41 type Output_Proc
is access procedure (S
: String);
42 -- This type is used for the Set_Special_Output procedure. If Output_Proc
43 -- is called, then instead of lines being written to standard error or
44 -- standard output, a call is made to the given procedure for each line,
45 -- passing the line with an end of line character (which is a single
46 -- ASCII.LF character, even in systems which normally use CR/LF or some
47 -- other sequence for line end).
53 procedure Set_Special_Output
(P
: Output_Proc
);
54 -- Sets subsequent output to call procedure P. If P is null, then the call
55 -- cancels the effect of a previous call, reverting the output to standard
56 -- error or standard output depending on the mode at the time of previous
57 -- call. Any exception generated by calls to P is simply propagated to
58 -- the caller of the routine causing the write operation.
60 procedure Cancel_Special_Output
;
61 -- Cancels the effect of a call to Set_Special_Output, if any. The output
62 -- is then directed to standard error or standard output depending on the
63 -- last call to Set_Standard_Error or Set_Standard_Output. It is never an
64 -- error to call Cancel_Special_Output. It has the same effect as calling
65 -- Set_Special_Output (null).
67 procedure Ignore_Output
(S
: String);
68 -- Does nothing. To disable output, pass Ignore_Output'Access to
69 -- Set_Special_Output.
71 procedure Set_Standard_Error
;
72 -- Sets subsequent output to appear on the standard error file (whatever
73 -- that might mean for the host operating system, if anything) when
74 -- no special output is in effect. When a special output is in effect,
75 -- the output will appear on standard error only after special output
76 -- has been cancelled.
78 procedure Set_Standard_Output
;
79 -- Sets subsequent output to appear on the standard output file (whatever
80 -- that might mean for the host operating system, if anything) when no
81 -- special output is in effect. When a special output is in effect, the
82 -- output will appear on standard output only after special output has been
83 -- cancelled. Output to standard output is the default mode before any call
84 -- to either of the Set procedures.
86 procedure Set_Output
(FD
: File_Descriptor
);
87 -- Sets subsequent output to appear on the given file descriptor when no
88 -- special output is in effect. When a special output is in effect, the
89 -- output will appear on the given file descriptor only after special
90 -- output has been cancelled.
92 procedure Push_Output
;
93 -- Saves the current output destination on a stack, but leaves it
94 -- unchanged. This subprogram only supports a small stack and is normally
95 -- used with a depth of one.
98 -- Changes the current output destination to be the last output destination
99 -- popped using Push_Output.
102 -- Increases the current indentation level. Whenever a line is written
103 -- (triggered by Eol), an appropriate amount of whitespace is added to the
104 -- beginning of the line, wrapping around if it gets too long.
107 -- Decreases the current indentation level
109 procedure Write_Char
(C
: Character);
110 -- Write one character to the standard output file. If the character is LF,
111 -- this is equivalent to Write_Eol.
113 procedure Write_Erase_Char
(C
: Character);
114 -- If last character in buffer matches C, erase it, otherwise no effect
117 -- Write an end of line (whatever is required by the system in use, e.g.
118 -- CR/LF for DOS, or LF for Unix) to the standard output file. This routine
119 -- also empties the line buffer, actually writing it to the file. Note that
120 -- Write_Eol is the only routine that causes any actual output to be
121 -- written. Trailing spaces are removed.
123 procedure Write_Eol_Keep_Blanks
;
124 -- Similar as Write_Eol, except that trailing spaces are not removed
126 procedure Write_Int
(Val
: Int
);
127 -- Write an integer value with no leading blanks or zeroes. Negative values
128 -- are preceded by a minus sign).
130 procedure Write_Spaces
(N
: Nat
);
133 procedure Write_Str
(S
: String);
134 -- Write a string of characters to the standard output file. Note that
135 -- end of line is normally handled separately using WRITE_EOL, but it is
136 -- allowable for the string to contain LF (but not CR) characters, which
137 -- are properly interpreted as end of line characters. The string may also
138 -- contain horizontal tab characters.
140 procedure Write_Line
(S
: String);
141 -- Equivalent to Write_Str (S) followed by Write_Eol;
143 function Last_Char
return Character;
144 -- Returns last character written on the current line, or null if the
145 -- current line is (so far) empty.
147 procedure Delete_Last_Char
;
148 -- Deletes last character written on the current line, no effect if the
149 -- current line is (so far) empty.
151 function Column
return Pos
;
152 pragma Inline
(Column
);
153 -- Returns the number of the column about to be written (e.g. a value of 1
154 -- means the current line is empty).
156 -------------------------
157 -- Buffer Save/Restore --
158 -------------------------
160 -- This facility allows the current line buffer to be saved and restored
162 type Saved_Output_Buffer
is private;
163 -- Type used for Save/Restore_Buffer
165 Buffer_Max
: constant := Hostparm
.Max_Line_Length
;
166 -- Maximal size of a buffered output line
168 function Save_Output_Buffer
return Saved_Output_Buffer
;
169 -- Save current line buffer and reset line buffer to empty
171 procedure Restore_Output_Buffer
(S
: Saved_Output_Buffer
);
172 -- Restore previously saved output buffer. The value in S is not affected
173 -- so it is legitimate to restore a buffer more than once.
175 --------------------------
176 -- Debugging Procedures --
177 --------------------------
179 -- The following procedures are intended only for debugging purposes,
180 -- for temporary insertion into the text in environments where a debugger
181 -- is not available. They all have non-standard very short lower case
182 -- names, precisely to make sure that they are only used for debugging.
184 procedure w
(C
: Character);
185 -- Dump quote, character, quote, followed by line return
187 procedure w
(S
: String);
188 -- Dump string followed by line return
190 procedure w
(V
: Int
);
191 -- Dump integer followed by line return
193 procedure w
(B
: Boolean);
194 -- Dump Boolean followed by line return
196 procedure w
(L
: String; C
: Character);
197 -- Dump contents of string followed by blank, quote, character, quote
199 procedure w
(L
: String; S
: String);
200 -- Dump two strings separated by blanks, followed by line return
202 procedure w
(L
: String; V
: Int
);
203 -- Dump contents of string followed by blank, integer, line return
205 procedure w
(L
: String; B
: Boolean);
206 -- Dump contents of string followed by blank, Boolean, line return
210 type Saved_Output_Buffer
is record
211 Buffer
: String (1 .. Buffer_Max
+ 1);
213 Cur_Indentation
: Natural;