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d9fcf2fb | 1 | /* UI_FILE - a generic STDIO like output stream. |
e2882c85 | 2 | Copyright (C) 1999-2018 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 PA |
22 | #include <string> |
23 | ||
d7e74731 PA |
24 | /* The abstract ui_file base class. */ |
25 | ||
26 | class ui_file | |
27 | { | |
28 | public: | |
29 | ui_file (); | |
30 | virtual ~ui_file () = 0; | |
d9fcf2fb | 31 | |
d7e74731 | 32 | /* Public non-virtual API. */ |
d9fcf2fb | 33 | |
d7e74731 | 34 | void printf (const char *, ...) ATTRIBUTE_PRINTF (2, 3); |
d9fcf2fb | 35 | |
d7e74731 PA |
36 | /* Print a string whose delimiter is QUOTER. Note that these |
37 | routines should only be called for printing things which are | |
38 | independent of the language of the program being debugged. */ | |
39 | void putstr (const char *str, int quoter); | |
d9fcf2fb | 40 | |
d7e74731 | 41 | void putstrn (const char *str, int n, int quoter); |
3e43a32a | 42 | |
d7e74731 | 43 | int putc (int c); |
3e43a32a | 44 | |
d7e74731 | 45 | void vprintf (const char *, va_list) ATTRIBUTE_PRINTF (2, 0); |
01124a23 | 46 | |
d7e74731 PA |
47 | /* Methods below are both public, and overridable by ui_file |
48 | subclasses. */ | |
3e43a32a | 49 | |
d7e74731 | 50 | virtual void write (const char *buf, long length_buf) = 0; |
3e43a32a | 51 | |
d7e74731 PA |
52 | /* This version of "write" is safe for use in signal handlers. It's |
53 | not guaranteed that all existing output will have been flushed | |
54 | first. Implementations are also free to ignore some or all of | |
55 | the request. puts_async is not provided as the async versions | |
56 | are rarely used, no point in having both for a rarely used | |
57 | interface. */ | |
58 | virtual void write_async_safe (const char *buf, long length_buf) | |
59 | { gdb_assert_not_reached ("write_async_safe"); } | |
3e43a32a | 60 | |
d7e74731 PA |
61 | /* Some ui_files override this to provide a efficient implementation |
62 | that avoids a strlen. */ | |
63 | virtual void puts (const char *str) | |
64 | { this->write (str, strlen (str)); } | |
d9fcf2fb | 65 | |
d7e74731 PA |
66 | virtual long read (char *buf, long length_buf) |
67 | { gdb_assert_not_reached ("can't read from this file type"); } | |
d9fcf2fb | 68 | |
d7e74731 PA |
69 | virtual bool isatty () |
70 | { return false; } | |
2a9d5ccf | 71 | |
d7e74731 PA |
72 | virtual void flush () |
73 | {} | |
74 | }; | |
d9fcf2fb | 75 | |
d7e74731 | 76 | typedef std::unique_ptr<ui_file> ui_file_up; |
d9fcf2fb | 77 | |
d7e74731 | 78 | /* A ui_file that writes to nowhere. */ |
d9fcf2fb | 79 | |
d7e74731 PA |
80 | class null_file : public ui_file |
81 | { | |
82 | public: | |
83 | void write (const char *buf, long length_buf) override; | |
84 | void write_async_safe (const char *buf, long sizeof_buf) override; | |
85 | void puts (const char *str) override; | |
86 | }; | |
d9fcf2fb | 87 | |
d7e74731 PA |
88 | /* A preallocated null_file stream. */ |
89 | extern null_file null_stream; | |
90 | ||
91 | extern void gdb_flush (ui_file *); | |
d9fcf2fb JM |
92 | |
93 | extern int ui_file_isatty (struct ui_file *); | |
94 | ||
3e43a32a MS |
95 | extern void ui_file_write (struct ui_file *file, const char *buf, |
96 | long length_buf); | |
d9fcf2fb | 97 | |
01124a23 DE |
98 | extern void ui_file_write_async_safe (struct ui_file *file, const char *buf, |
99 | long length_buf); | |
100 | ||
d7e74731 PA |
101 | extern long ui_file_read (struct ui_file *file, char *buf, long length_buf); |
102 | ||
103 | /* A std::string-based ui_file. Can be used as a scratch buffer for | |
104 | collecting output. */ | |
d9fcf2fb | 105 | |
d7e74731 PA |
106 | class string_file : public ui_file |
107 | { | |
108 | public: | |
109 | string_file () {} | |
110 | ~string_file () override; | |
d9fcf2fb | 111 | |
d7e74731 | 112 | /* Override ui_file methods. */ |
8de00631 | 113 | |
d7e74731 | 114 | void write (const char *buf, long length_buf) override; |
d9fcf2fb | 115 | |
d7e74731 PA |
116 | long read (char *buf, long length_buf) override |
117 | { gdb_assert_not_reached ("a string_file is not readable"); } | |
118 | ||
119 | /* string_file-specific public API. */ | |
120 | ||
121 | /* Accesses the std::string containing the entire output collected | |
122 | so far. | |
123 | ||
124 | Returns a non-const reference so that it's easy to move the | |
125 | string contents out of the string_file. E.g.: | |
126 | ||
127 | string_file buf; | |
128 | buf.printf (....); | |
129 | buf.printf (....); | |
130 | return std::move (buf.string ()); | |
131 | */ | |
132 | std::string &string () { return m_string; } | |
133 | ||
134 | /* Provide a few convenience methods with the same API as the | |
135 | underlying std::string. */ | |
136 | const char *data () const { return m_string.data (); } | |
137 | const char *c_str () const { return m_string.c_str (); } | |
138 | size_t size () const { return m_string.size (); } | |
139 | bool empty () const { return m_string.empty (); } | |
140 | void clear () { return m_string.clear (); } | |
141 | ||
142 | private: | |
143 | /* The internal buffer. */ | |
144 | std::string m_string; | |
145 | }; | |
146 | ||
147 | /* A ui_file implementation that maps directly onto <stdio.h>'s FILE. | |
148 | A stdio_file can either own its underlying file, or not. If it | |
149 | owns the file, then destroying the stdio_file closes the underlying | |
150 | file, otherwise it is left open. */ | |
151 | ||
152 | class stdio_file : public ui_file | |
153 | { | |
154 | public: | |
155 | /* Create a ui_file from a previously opened FILE. CLOSE_P | |
156 | indicates whether the underlying file should be closed when the | |
157 | stdio_file is destroyed. */ | |
158 | explicit stdio_file (FILE *file, bool close_p = false); | |
159 | ||
160 | /* Create an stdio_file that is not managing any file yet. Call | |
161 | open to actually open something. */ | |
162 | stdio_file (); | |
163 | ||
164 | ~stdio_file () override; | |
165 | ||
166 | /* Open NAME in mode MODE, and own the resulting file. Returns true | |
167 | on success, false otherwise. If the stdio_file previously owned | |
168 | a file, it is closed. */ | |
169 | bool open (const char *name, const char *mode); | |
170 | ||
171 | void flush () override; | |
172 | ||
173 | void write (const char *buf, long length_buf) override; | |
174 | ||
175 | void write_async_safe (const char *buf, long length_buf) override; | |
176 | ||
177 | void puts (const char *) override; | |
178 | ||
179 | long read (char *buf, long length_buf) override; | |
180 | ||
181 | bool isatty () override; | |
182 | ||
183 | private: | |
184 | /* Sets the internal stream to FILE, and saves the FILE's file | |
185 | descriptor in M_FD. */ | |
186 | void set_stream (FILE *file); | |
187 | ||
188 | /* The file. */ | |
189 | FILE *m_file; | |
190 | ||
191 | /* The associated file descriptor is extracted ahead of time for | |
192 | stdio_file::write_async_safe's benefit, in case fileno isn't | |
193 | async-safe. */ | |
194 | int m_fd; | |
195 | ||
196 | /* If true, M_FILE is closed on destruction. */ | |
197 | bool m_close_p; | |
198 | }; | |
199 | ||
200 | typedef std::unique_ptr<stdio_file> stdio_file_up; | |
201 | ||
202 | /* Like stdio_file, but specifically for stderr. | |
203 | ||
204 | This exists because there is no real line-buffering on Windows, see | |
205 | <http://msdn.microsoft.com/en-us/library/86cebhfs%28v=vs.71%29.aspx> | |
206 | so the stdout is either fully-buffered or non-buffered. We can't | |
207 | make stdout non-buffered, because of two concerns: | |
449092f6 | 208 | |
d7e74731 PA |
209 | 1. Non-buffering hurts performance. |
210 | 2. Non-buffering may change GDB's behavior when it is interacting | |
211 | with a front-end, such as Emacs. | |
2a9d5ccf | 212 | |
d7e74731 PA |
213 | We leave stdout as fully buffered, but flush it first when |
214 | something is written to stderr. | |
d9fcf2fb | 215 | |
d7e74731 PA |
216 | Note that the 'write_async_safe' method is not overridden, because |
217 | there's no way to flush a stream in an async-safe manner. | |
218 | Fortunately, it doesn't really matter, because: | |
219 | ||
220 | 1. That method is only used for printing internal debug output | |
221 | from signal handlers. | |
222 | ||
223 | 2. Windows hosts don't have a concept of async-safeness. Signal | |
224 | handlers run in a separate thread, so they can call the regular | |
225 | non-async-safe output routines freely. | |
226 | */ | |
227 | class stderr_file : public stdio_file | |
228 | { | |
229 | public: | |
230 | explicit stderr_file (FILE *stream); | |
231 | ||
232 | /* Override the output routines to flush gdb_stdout before deferring | |
233 | to stdio_file for the actual outputting. */ | |
234 | void write (const char *buf, long length_buf) override; | |
235 | void puts (const char *linebuffer) override; | |
236 | }; | |
d9fcf2fb | 237 | |
d7e74731 | 238 | /* A ui_file implementation that maps onto two ui-file objects. */ |
d9fcf2fb | 239 | |
d7e74731 PA |
240 | class tee_file : public ui_file |
241 | { | |
242 | public: | |
243 | /* Create a file which writes to both ONE and TWO. CLOSE_ONE and | |
244 | CLOSE_TWO indicate whether the original files should be closed | |
245 | when the new file is closed. */ | |
246 | tee_file (ui_file *one, bool close_one, | |
247 | ui_file *two, bool close_two); | |
248 | ~tee_file () override; | |
d9fcf2fb | 249 | |
d7e74731 PA |
250 | void write (const char *buf, long length_buf) override; |
251 | void write_async_safe (const char *buf, long length_buf) override; | |
252 | void puts (const char *) override; | |
ffa4ac95 | 253 | |
d7e74731 PA |
254 | bool isatty () override; |
255 | void flush () override; | |
ffa4ac95 | 256 | |
d7e74731 PA |
257 | private: |
258 | /* The two underlying ui_files, and whether they should each be | |
259 | closed on destruction. */ | |
260 | ui_file *m_one, *m_two; | |
261 | bool m_close_one, m_close_two; | |
262 | }; | |
d9fcf2fb JM |
263 | |
264 | #endif |