|
2982
|
1 /* |
|
|
2 |
|
|
3 Copyright (C) 1996, 1997 John W. Eaton |
|
|
4 |
|
|
5 This file is part of Octave. |
|
|
6 |
|
|
7 Octave is free software; you can redistribute it and/or modify it |
|
|
8 under the terms of the GNU General Public License as published by the |
|
7016
|
9 Free Software Foundation; either version 3 of the License, or (at your |
|
|
10 option) any later version. |
|
2982
|
11 |
|
|
12 Octave is distributed in the hope that it will be useful, but WITHOUT |
|
|
13 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
|
|
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
|
|
15 for more details. |
|
|
16 |
|
|
17 You should have received a copy of the GNU General Public License |
|
7016
|
18 along with Octave; see the file COPYING. If not, see |
|
|
19 <http://www.gnu.org/licenses/>. |
|
2982
|
20 |
|
|
21 */ |
|
|
22 |
|
|
23 #ifdef HAVE_CONFIG_H |
|
|
24 #include <config.h> |
|
|
25 #endif |
|
|
26 |
|
4429
|
27 #include "quit.h" |
|
|
28 |
|
2982
|
29 #include "error.h" |
|
|
30 #include "oct-lvalue.h" |
|
|
31 #include "ov.h" |
|
3770
|
32 #include "pt-bp.h" |
|
2982
|
33 #include "pt-cmd.h" |
|
|
34 #include "pt-except.h" |
|
|
35 #include "pt-exp.h" |
|
2985
|
36 #include "pt-jump.h" |
|
2982
|
37 #include "pt-stmt.h" |
|
|
38 #include "pt-walk.h" |
|
|
39 #include "unwind-prot.h" |
|
|
40 #include "variables.h" |
|
|
41 |
|
|
42 // Simple exception handling. |
|
|
43 |
|
|
44 tree_try_catch_command::~tree_try_catch_command (void) |
|
|
45 { |
|
|
46 delete try_code; |
|
|
47 delete catch_code; |
|
3665
|
48 delete lead_comm; |
|
|
49 delete mid_comm; |
|
|
50 delete trail_comm; |
|
2982
|
51 } |
|
|
52 |
|
|
53 static void |
|
|
54 do_catch_code (void *ptr) |
|
|
55 { |
|
4793
|
56 // Is it safe to call OCTAVE_QUIT here? We are already running |
|
|
57 // something on the unwind_protect stack, but the element for this |
|
|
58 // action would have already been popped from the top of the stack, |
|
|
59 // so we should not be attempting to run it again. |
|
|
60 |
|
|
61 OCTAVE_QUIT; |
|
|
62 |
|
|
63 // If we are interrupting immediately, or if an interrupt is in |
|
|
64 // progress (octave_interrupt_state < 0), then we don't want to run |
|
|
65 // the catch code (it should only run on errors, not interrupts). |
|
|
66 |
|
|
67 // If octave_interrupt_state is positive, an interrupt is pending. |
|
|
68 // The only way that could happen would be for the interrupt to |
|
|
69 // come in after the OCTAVE_QUIT above and before the if statement |
|
|
70 // below -- it's possible, but unlikely. In any case, we should |
|
|
71 // probably let the catch code throw the exception because we don't |
|
|
72 // want to skip that and potentially run some other code. For |
|
|
73 // example, an error may have originally brought us here for some |
|
|
74 // cleanup operation and we shouldn't skip that. |
|
|
75 |
|
|
76 if (octave_interrupt_immediately || octave_interrupt_state < 0) |
|
4429
|
77 return; |
|
|
78 |
|
2982
|
79 tree_statement_list *list = static_cast<tree_statement_list *> (ptr); |
|
|
80 |
|
|
81 // Set up for letting the user print any messages from errors that |
|
|
82 // occurred in the body of the try_catch statement. |
|
|
83 |
|
4699
|
84 buffer_error_messages--; |
|
2982
|
85 |
|
|
86 if (list) |
|
|
87 list->eval (); |
|
|
88 } |
|
|
89 |
|
|
90 void |
|
|
91 tree_try_catch_command::eval (void) |
|
|
92 { |
|
2985
|
93 unwind_protect::begin_frame ("tree_try_catch::eval"); |
|
3770
|
94 |
|
|
95 MAYBE_DO_BREAKPOINT; |
|
2982
|
96 |
|
5344
|
97 unwind_protect_int (buffer_error_messages); |
|
|
98 buffer_error_messages++; |
|
2982
|
99 |
|
3490
|
100 unwind_protect::add (do_catch_code, catch_code); |
|
|
101 |
|
2982
|
102 if (try_code) |
|
|
103 try_code->eval (); |
|
|
104 |
|
|
105 if (catch_code && error_state) |
|
|
106 { |
|
|
107 error_state = 0; |
|
2985
|
108 unwind_protect::run_frame ("tree_try_catch::eval"); |
|
2982
|
109 } |
|
|
110 else |
|
|
111 { |
|
|
112 error_state = 0; |
|
3490
|
113 |
|
4699
|
114 // Unwind stack elements must be cleared or run in the reverse |
|
|
115 // order in which they were added to the stack. |
|
|
116 |
|
3490
|
117 // For clearing the do_catch_code cleanup function. |
|
|
118 unwind_protect::discard (); |
|
|
119 |
|
|
120 // For restoring buffer_error_messages. |
|
5344
|
121 unwind_protect::run (); |
|
3585
|
122 |
|
|
123 // Also clear the frame marker. |
|
|
124 unwind_protect::discard (); |
|
2982
|
125 } |
|
|
126 } |
|
|
127 |
|
5861
|
128 tree_command * |
|
|
129 tree_try_catch_command::dup (symbol_table *sym_tab) |
|
|
130 { |
|
|
131 return new tree_try_catch_command (try_code ? try_code->dup (sym_tab) : 0, |
|
|
132 catch_code ? catch_code->dup (sym_tab) : 0, |
|
|
133 lead_comm ? lead_comm->dup () : 0, |
|
|
134 mid_comm ? mid_comm->dup () : 0, |
|
|
135 trail_comm ? trail_comm->dup () : 0, |
|
|
136 line (), column ()); |
|
|
137 } |
|
|
138 |
|
2982
|
139 void |
|
|
140 tree_try_catch_command::accept (tree_walker& tw) |
|
|
141 { |
|
|
142 tw.visit_try_catch_command (*this); |
|
|
143 } |
|
|
144 |
|
|
145 // Simple exception handling. |
|
|
146 |
|
|
147 tree_unwind_protect_command::~tree_unwind_protect_command (void) |
|
|
148 { |
|
|
149 delete unwind_protect_code; |
|
|
150 delete cleanup_code; |
|
3665
|
151 delete lead_comm; |
|
|
152 delete mid_comm; |
|
|
153 delete trail_comm; |
|
2982
|
154 } |
|
|
155 |
|
|
156 static void |
|
|
157 do_unwind_protect_cleanup_code (void *ptr) |
|
|
158 { |
|
|
159 tree_statement_list *list = static_cast<tree_statement_list *> (ptr); |
|
|
160 |
|
|
161 // We want to run the cleanup code without error_state being set, |
|
|
162 // but we need to restore its value, so that any errors encountered |
|
|
163 // in the first part of the unwind_protect are not completely |
|
|
164 // ignored. |
|
|
165 |
|
|
166 unwind_protect_int (error_state); |
|
|
167 error_state = 0; |
|
|
168 |
|
|
169 // Similarly, if we have seen a return or break statement, allow all |
|
|
170 // the cleanup code to run before returning or handling the break. |
|
|
171 // We don't have to worry about continue statements because they can |
|
|
172 // only occur in loops. |
|
|
173 |
|
4207
|
174 unwind_protect_int (tree_return_command::returning); |
|
|
175 tree_return_command::returning = 0; |
|
2982
|
176 |
|
4207
|
177 unwind_protect_int (tree_break_command::breaking); |
|
|
178 tree_break_command::breaking = 0; |
|
2982
|
179 |
|
|
180 if (list) |
|
|
181 list->eval (); |
|
|
182 |
|
3491
|
183 // The unwind_protects are popped off the stack in the reverse of |
|
|
184 // the order they are pushed on. |
|
2982
|
185 |
|
5775
|
186 // FIXME -- these statements say that if we see a break or |
|
3491
|
187 // return statement in the cleanup block, that we want to use the |
|
|
188 // new value of the breaking or returning flag instead of restoring |
|
|
189 // the previous value. Is that the right thing to do? I think so. |
|
|
190 // Consider the case of |
|
|
191 // |
|
|
192 // function foo () |
|
|
193 // unwind_protect |
|
|
194 // stderr << "1: this should always be executed\n"; |
|
|
195 // break; |
|
|
196 // stderr << "1: this should never be executed\n"; |
|
|
197 // unwind_protect_cleanup |
|
|
198 // stderr << "2: this should always be executed\n"; |
|
|
199 // return; |
|
|
200 // stderr << "2: this should never be executed\n"; |
|
|
201 // end_unwind_protect |
|
|
202 // endfunction |
|
|
203 // |
|
|
204 // If we reset the value of the breaking flag, both the returning |
|
|
205 // flag and the breaking flag will be set, and we shouldn't have |
|
|
206 // both. So, use the most recent one. If there is no return or |
|
|
207 // break in the cleanup block, the values should be reset to |
|
|
208 // whatever they were when the cleanup block was entered. |
|
2982
|
209 |
|
4207
|
210 if (tree_break_command::breaking || tree_return_command::returning) |
|
3491
|
211 { |
|
|
212 unwind_protect::discard (); |
|
|
213 unwind_protect::discard (); |
|
|
214 } |
|
2982
|
215 else |
|
3491
|
216 { |
|
|
217 unwind_protect::run (); |
|
|
218 unwind_protect::run (); |
|
|
219 } |
|
2982
|
220 |
|
|
221 // We don't want to ignore errors that occur in the cleanup code, so |
|
|
222 // if an error is encountered there, leave error_state alone. |
|
|
223 // Otherwise, set it back to what it was before. |
|
|
224 |
|
|
225 if (error_state) |
|
2985
|
226 unwind_protect::discard (); |
|
2982
|
227 else |
|
2985
|
228 unwind_protect::run (); |
|
2982
|
229 } |
|
|
230 |
|
|
231 void |
|
|
232 tree_unwind_protect_command::eval (void) |
|
|
233 { |
|
2985
|
234 unwind_protect::add (do_unwind_protect_cleanup_code, cleanup_code); |
|
2982
|
235 |
|
3770
|
236 MAYBE_DO_BREAKPOINT; |
|
|
237 |
|
2982
|
238 if (unwind_protect_code) |
|
|
239 unwind_protect_code->eval (); |
|
|
240 |
|
2985
|
241 unwind_protect::run (); |
|
2982
|
242 } |
|
|
243 |
|
5861
|
244 tree_command * |
|
|
245 tree_unwind_protect_command::dup (symbol_table *sym_tab) |
|
|
246 { |
|
|
247 return new tree_unwind_protect_command |
|
|
248 (unwind_protect_code ? unwind_protect_code->dup (sym_tab) : 0, |
|
|
249 cleanup_code ? cleanup_code->dup (sym_tab) : 0, |
|
|
250 lead_comm ? lead_comm->dup () : 0, |
|
|
251 mid_comm ? mid_comm->dup () : 0, |
|
|
252 trail_comm ? trail_comm->dup () : 0, |
|
|
253 line (), column ()); |
|
|
254 } |
|
|
255 |
|
2982
|
256 void |
|
|
257 tree_unwind_protect_command::accept (tree_walker& tw) |
|
|
258 { |
|
|
259 tw.visit_unwind_protect_command (*this); |
|
|
260 } |
|
|
261 |
|
|
262 /* |
|
|
263 ;;; Local Variables: *** |
|
|
264 ;;; mode: C++ *** |
|
|
265 ;;; End: *** |
|
|
266 */ |
