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d9fcf2fb | 1 | /* UI_FILE - a generic STDIO like output stream. |
42a4f53d | 2 | Copyright (C) 1999-2019 Free Software Foundation, Inc. |
d9fcf2fb JM |
3 | |
4 | This file is part of GDB. | |
5 | ||
6 | This program is free software; you can redistribute it and/or modify | |
7 | it under the terms of the GNU General Public License as published by | |
a9762ec7 | 8 | the Free Software Foundation; either version 3 of the License, or |
d9fcf2fb JM |
9 | (at your option) any later version. |
10 | ||
11 | This program is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
a9762ec7 | 17 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
d9fcf2fb JM |
18 | |
19 | #ifndef UI_FILE_H | |
20 | #define UI_FILE_H | |
21 | ||
8de00631 | 22 | #include <string> |
eedeedd2 | 23 | #include "ui-style.h" |
8de00631 | 24 | |
d7e74731 PA |
25 | /* The abstract ui_file base class. */ |
26 | ||
27 | class ui_file | |
28 | { | |
29 | public: | |
30 | ui_file (); | |
31 | virtual ~ui_file () = 0; | |
d9fcf2fb | 32 | |
d7e74731 | 33 | /* Public non-virtual API. */ |
d9fcf2fb | 34 | |
d7e74731 | 35 | void printf (const char *, ...) ATTRIBUTE_PRINTF (2, 3); |
d9fcf2fb | 36 | |
d7e74731 PA |
37 | /* Print a string whose delimiter is QUOTER. Note that these |
38 | routines should only be called for printing things which are | |
39 | independent of the language of the program being debugged. */ | |
40 | void putstr (const char *str, int quoter); | |
d9fcf2fb | 41 | |
d7e74731 | 42 | void putstrn (const char *str, int n, int quoter); |
3e43a32a | 43 | |
d7e74731 | 44 | int putc (int c); |
3e43a32a | 45 | |
d7e74731 | 46 | void vprintf (const char *, va_list) ATTRIBUTE_PRINTF (2, 0); |
01124a23 | 47 | |
d7e74731 PA |
48 | /* Methods below are both public, and overridable by ui_file |
49 | subclasses. */ | |
3e43a32a | 50 | |
d7e74731 | 51 | virtual void write (const char *buf, long length_buf) = 0; |
3e43a32a | 52 | |
d7e74731 PA |
53 | /* This version of "write" is safe for use in signal handlers. It's |
54 | not guaranteed that all existing output will have been flushed | |
55 | first. Implementations are also free to ignore some or all of | |
56 | the request. puts_async is not provided as the async versions | |
57 | are rarely used, no point in having both for a rarely used | |
58 | interface. */ | |
59 | virtual void write_async_safe (const char *buf, long length_buf) | |
60 | { gdb_assert_not_reached ("write_async_safe"); } | |
3e43a32a | 61 | |
d7e74731 PA |
62 | /* Some ui_files override this to provide a efficient implementation |
63 | that avoids a strlen. */ | |
64 | virtual void puts (const char *str) | |
65 | { this->write (str, strlen (str)); } | |
d9fcf2fb | 66 | |
d7e74731 PA |
67 | virtual long read (char *buf, long length_buf) |
68 | { gdb_assert_not_reached ("can't read from this file type"); } | |
d9fcf2fb | 69 | |
d7e74731 PA |
70 | virtual bool isatty () |
71 | { return false; } | |
2a9d5ccf | 72 | |
d7e74731 PA |
73 | virtual void flush () |
74 | {} | |
75 | }; | |
d9fcf2fb | 76 | |
d7e74731 | 77 | typedef std::unique_ptr<ui_file> ui_file_up; |
d9fcf2fb | 78 | |
d7e74731 | 79 | /* A ui_file that writes to nowhere. */ |
d9fcf2fb | 80 | |
d7e74731 PA |
81 | class null_file : public ui_file |
82 | { | |
83 | public: | |
84 | void write (const char *buf, long length_buf) override; | |
85 | void write_async_safe (const char *buf, long sizeof_buf) override; | |
86 | void puts (const char *str) override; | |
87 | }; | |
d9fcf2fb | 88 | |
d7e74731 PA |
89 | /* A preallocated null_file stream. */ |
90 | extern null_file null_stream; | |
91 | ||
92 | extern void gdb_flush (ui_file *); | |
d9fcf2fb JM |
93 | |
94 | extern int ui_file_isatty (struct ui_file *); | |
95 | ||
3e43a32a MS |
96 | extern void ui_file_write (struct ui_file *file, const char *buf, |
97 | long length_buf); | |
d9fcf2fb | 98 | |
01124a23 DE |
99 | extern void ui_file_write_async_safe (struct ui_file *file, const char *buf, |
100 | long length_buf); | |
101 | ||
d7e74731 PA |
102 | extern long ui_file_read (struct ui_file *file, char *buf, long length_buf); |
103 | ||
104 | /* A std::string-based ui_file. Can be used as a scratch buffer for | |
105 | collecting output. */ | |
d9fcf2fb | 106 | |
d7e74731 PA |
107 | class string_file : public ui_file |
108 | { | |
109 | public: | |
110 | string_file () {} | |
111 | ~string_file () override; | |
d9fcf2fb | 112 | |
d7e74731 | 113 | /* Override ui_file methods. */ |
8de00631 | 114 | |
d7e74731 | 115 | void write (const char *buf, long length_buf) override; |
d9fcf2fb | 116 | |
d7e74731 PA |
117 | long read (char *buf, long length_buf) override |
118 | { gdb_assert_not_reached ("a string_file is not readable"); } | |
119 | ||
120 | /* string_file-specific public API. */ | |
121 | ||
122 | /* Accesses the std::string containing the entire output collected | |
123 | so far. | |
124 | ||
125 | Returns a non-const reference so that it's easy to move the | |
126 | string contents out of the string_file. E.g.: | |
127 | ||
128 | string_file buf; | |
129 | buf.printf (....); | |
130 | buf.printf (....); | |
131 | return std::move (buf.string ()); | |
132 | */ | |
133 | std::string &string () { return m_string; } | |
134 | ||
135 | /* Provide a few convenience methods with the same API as the | |
136 | underlying std::string. */ | |
137 | const char *data () const { return m_string.data (); } | |
138 | const char *c_str () const { return m_string.c_str (); } | |
139 | size_t size () const { return m_string.size (); } | |
140 | bool empty () const { return m_string.empty (); } | |
141 | void clear () { return m_string.clear (); } | |
142 | ||
143 | private: | |
144 | /* The internal buffer. */ | |
145 | std::string m_string; | |
146 | }; | |
147 | ||
148 | /* A ui_file implementation that maps directly onto <stdio.h>'s FILE. | |
149 | A stdio_file can either own its underlying file, or not. If it | |
150 | owns the file, then destroying the stdio_file closes the underlying | |
151 | file, otherwise it is left open. */ | |
152 | ||
153 | class stdio_file : public ui_file | |
154 | { | |
155 | public: | |
156 | /* Create a ui_file from a previously opened FILE. CLOSE_P | |
157 | indicates whether the underlying file should be closed when the | |
158 | stdio_file is destroyed. */ | |
159 | explicit stdio_file (FILE *file, bool close_p = false); | |
160 | ||
161 | /* Create an stdio_file that is not managing any file yet. Call | |
162 | open to actually open something. */ | |
163 | stdio_file (); | |
164 | ||
165 | ~stdio_file () override; | |
166 | ||
167 | /* Open NAME in mode MODE, and own the resulting file. Returns true | |
168 | on success, false otherwise. If the stdio_file previously owned | |
169 | a file, it is closed. */ | |
170 | bool open (const char *name, const char *mode); | |
171 | ||
172 | void flush () override; | |
173 | ||
174 | void write (const char *buf, long length_buf) override; | |
175 | ||
176 | void write_async_safe (const char *buf, long length_buf) override; | |
177 | ||
178 | void puts (const char *) override; | |
179 | ||
180 | long read (char *buf, long length_buf) override; | |
181 | ||
182 | bool isatty () override; | |
183 | ||
184 | private: | |
185 | /* Sets the internal stream to FILE, and saves the FILE's file | |
186 | descriptor in M_FD. */ | |
187 | void set_stream (FILE *file); | |
188 | ||
189 | /* The file. */ | |
190 | FILE *m_file; | |
191 | ||
192 | /* The associated file descriptor is extracted ahead of time for | |
193 | stdio_file::write_async_safe's benefit, in case fileno isn't | |
194 | async-safe. */ | |
195 | int m_fd; | |
196 | ||
197 | /* If true, M_FILE is closed on destruction. */ | |
198 | bool m_close_p; | |
199 | }; | |
200 | ||
201 | typedef std::unique_ptr<stdio_file> stdio_file_up; | |
202 | ||
203 | /* Like stdio_file, but specifically for stderr. | |
204 | ||
205 | This exists because there is no real line-buffering on Windows, see | |
206 | <http://msdn.microsoft.com/en-us/library/86cebhfs%28v=vs.71%29.aspx> | |
207 | so the stdout is either fully-buffered or non-buffered. We can't | |
208 | make stdout non-buffered, because of two concerns: | |
449092f6 | 209 | |
d7e74731 PA |
210 | 1. Non-buffering hurts performance. |
211 | 2. Non-buffering may change GDB's behavior when it is interacting | |
212 | with a front-end, such as Emacs. | |
2a9d5ccf | 213 | |
d7e74731 PA |
214 | We leave stdout as fully buffered, but flush it first when |
215 | something is written to stderr. | |
d9fcf2fb | 216 | |
d7e74731 PA |
217 | Note that the 'write_async_safe' method is not overridden, because |
218 | there's no way to flush a stream in an async-safe manner. | |
219 | Fortunately, it doesn't really matter, because: | |
220 | ||
221 | 1. That method is only used for printing internal debug output | |
222 | from signal handlers. | |
223 | ||
224 | 2. Windows hosts don't have a concept of async-safeness. Signal | |
225 | handlers run in a separate thread, so they can call the regular | |
226 | non-async-safe output routines freely. | |
227 | */ | |
228 | class stderr_file : public stdio_file | |
229 | { | |
230 | public: | |
231 | explicit stderr_file (FILE *stream); | |
232 | ||
233 | /* Override the output routines to flush gdb_stdout before deferring | |
234 | to stdio_file for the actual outputting. */ | |
235 | void write (const char *buf, long length_buf) override; | |
236 | void puts (const char *linebuffer) override; | |
237 | }; | |
d9fcf2fb | 238 | |
d7e74731 | 239 | /* A ui_file implementation that maps onto two ui-file objects. */ |
d9fcf2fb | 240 | |
d7e74731 PA |
241 | class tee_file : public ui_file |
242 | { | |
243 | public: | |
244 | /* Create a file which writes to both ONE and TWO. CLOSE_ONE and | |
245 | CLOSE_TWO indicate whether the original files should be closed | |
246 | when the new file is closed. */ | |
247 | tee_file (ui_file *one, bool close_one, | |
248 | ui_file *two, bool close_two); | |
249 | ~tee_file () override; | |
d9fcf2fb | 250 | |
d7e74731 PA |
251 | void write (const char *buf, long length_buf) override; |
252 | void write_async_safe (const char *buf, long length_buf) override; | |
253 | void puts (const char *) override; | |
ffa4ac95 | 254 | |
d7e74731 PA |
255 | bool isatty () override; |
256 | void flush () override; | |
ffa4ac95 | 257 | |
d7e74731 PA |
258 | private: |
259 | /* The two underlying ui_files, and whether they should each be | |
260 | closed on destruction. */ | |
261 | ui_file *m_one, *m_two; | |
262 | bool m_close_one, m_close_two; | |
263 | }; | |
d9fcf2fb JM |
264 | |
265 | #endif |