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1 /* Invalid parameter handler for MSVC runtime libraries.
2 Copyright (C) 2011-2021 Free Software Foundation, Inc.
3
4 This file is free software: you can redistribute it and/or modify
5 it under the terms of the GNU Lesser General Public License as
6 published by the Free Software Foundation; either version 2.1 of the
7 License, or (at your option) any later version.
8
9 This file is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public License
15 along with this program. If not, see <https://www.gnu.org/licenses/>. */
16
17 #ifndef _MSVC_INVAL_H
18 #define _MSVC_INVAL_H
19
20 /* With MSVC runtime libraries with the "invalid parameter handler" concept,
21 functions like fprintf(), dup2(), or close() crash when the caller passes
22 an invalid argument. But POSIX wants error codes (such as EINVAL or EBADF)
23 instead.
24 This file defines macros that turn such an invalid parameter notification
25 into a non-local exit. An error code can then be produced at the target
26 of this exit. You can thus write code like
27
28 TRY_MSVC_INVAL
29 {
30 <Code that can trigger an invalid parameter notification
31 but does not do 'return', 'break', 'continue', nor 'goto'.>
32 }
33 CATCH_MSVC_INVAL
34 {
35 <Code that handles an invalid parameter notification
36 but does not do 'return', 'break', 'continue', nor 'goto'.>
37 }
38 DONE_MSVC_INVAL;
39
40 This entire block expands to a single statement.
41
42 The handling of invalid parameters can be done in three ways:
43
44 * The default way, which is reasonable for programs (not libraries):
45 AC_DEFINE([MSVC_INVALID_PARAMETER_HANDLING], [DEFAULT_HANDLING])
46
47 * The way for libraries that make "hairy" calls (like close(-1), or
48 fclose(fp) where fileno(fp) is closed, or simply getdtablesize()):
49 AC_DEFINE([MSVC_INVALID_PARAMETER_HANDLING], [HAIRY_LIBRARY_HANDLING])
50
51 * The way for libraries that make no "hairy" calls:
52 AC_DEFINE([MSVC_INVALID_PARAMETER_HANDLING], [SANE_LIBRARY_HANDLING])
53 */
54
55 #define DEFAULT_HANDLING 0
56 #define HAIRY_LIBRARY_HANDLING 1
57 #define SANE_LIBRARY_HANDLING 2
58
59 #if HAVE_MSVC_INVALID_PARAMETER_HANDLER \
60 && !(MSVC_INVALID_PARAMETER_HANDLING == SANE_LIBRARY_HANDLING)
61 /* A native Windows platform with the "invalid parameter handler" concept,
62 and either DEFAULT_HANDLING or HAIRY_LIBRARY_HANDLING. */
63
64 # if MSVC_INVALID_PARAMETER_HANDLING == DEFAULT_HANDLING
65 /* Default handling. */
66
67 # ifdef __cplusplus
68 extern "C" {
69 # endif
70
71 /* Ensure that the invalid parameter handler in installed that just returns.
72 Because we assume no other part of the program installs a different
73 invalid parameter handler, this solution is multithread-safe. */
74 extern void gl_msvc_inval_ensure_handler (void);
75
76 # ifdef __cplusplus
77 }
78 # endif
79
80 # define TRY_MSVC_INVAL \
81 do \
82 { \
83 gl_msvc_inval_ensure_handler (); \
84 if (1)
85 # define CATCH_MSVC_INVAL \
86 else
87 # define DONE_MSVC_INVAL \
88 } \
89 while (0)
90
91 # else
92 /* Handling for hairy libraries. */
93
94 # include <excpt.h>
95
96 /* Gnulib can define its own status codes, as described in the page
97 "Raising Software Exceptions" on microsoft.com
98 <https://docs.microsoft.com/en-us/cpp/cpp/raising-software-exceptions>.
99 Our status codes are composed of
100 - 0xE0000000, mandatory for all user-defined status codes,
101 - 0x474E550, a API identifier ("GNU"),
102 - 0, 1, 2, ..., used to distinguish different status codes from the
103 same API. */
104 # define STATUS_GNULIB_INVALID_PARAMETER (0xE0000000 + 0x474E550 + 0)
105
106 # if defined _MSC_VER
107 /* A compiler that supports __try/__except, as described in the page
108 "try-except statement" on microsoft.com
109 <https://docs.microsoft.com/en-us/cpp/cpp/try-except-statement>.
110 With __try/__except, we can use the multithread-safe exception handling. */
111
112 # ifdef __cplusplus
113 extern "C" {
114 # endif
115
116 /* Ensure that the invalid parameter handler in installed that raises a
117 software exception with code STATUS_GNULIB_INVALID_PARAMETER.
118 Because we assume no other part of the program installs a different
119 invalid parameter handler, this solution is multithread-safe. */
120 extern void gl_msvc_inval_ensure_handler (void);
121
122 # ifdef __cplusplus
123 }
124 # endif
125
126 # define TRY_MSVC_INVAL \
127 do \
128 { \
129 gl_msvc_inval_ensure_handler (); \
130 __try
131 # define CATCH_MSVC_INVAL \
132 __except (GetExceptionCode () == STATUS_GNULIB_INVALID_PARAMETER \
133 ? EXCEPTION_EXECUTE_HANDLER \
134 : EXCEPTION_CONTINUE_SEARCH)
135 # define DONE_MSVC_INVAL \
136 } \
137 while (0)
138
139 # else
140 /* Any compiler.
141 We can only use setjmp/longjmp. */
142
143 # include <setjmp.h>
144
145 # ifdef __cplusplus
146 extern "C" {
147 # endif
148
149 struct gl_msvc_inval_per_thread
150 {
151 /* The restart that will resume execution at the code between
152 CATCH_MSVC_INVAL and DONE_MSVC_INVAL. It is enabled only between
153 TRY_MSVC_INVAL and CATCH_MSVC_INVAL. */
154 jmp_buf restart;
155
156 /* Tells whether the contents of restart is valid. */
157 int restart_valid;
158 };
159
160 /* Ensure that the invalid parameter handler in installed that passes
161 control to the gl_msvc_inval_restart if it is valid, or raises a
162 software exception with code STATUS_GNULIB_INVALID_PARAMETER otherwise.
163 Because we assume no other part of the program installs a different
164 invalid parameter handler, this solution is multithread-safe. */
165 extern void gl_msvc_inval_ensure_handler (void);
166
167 /* Return a pointer to the per-thread data for the current thread. */
168 extern struct gl_msvc_inval_per_thread *gl_msvc_inval_current (void);
169
170 # ifdef __cplusplus
171 }
172 # endif
173
174 # define TRY_MSVC_INVAL \
175 do \
176 { \
177 struct gl_msvc_inval_per_thread *msvc_inval_current; \
178 gl_msvc_inval_ensure_handler (); \
179 msvc_inval_current = gl_msvc_inval_current (); \
180 /* First, initialize gl_msvc_inval_restart. */ \
181 if (setjmp (msvc_inval_current->restart) == 0) \
182 { \
183 /* Then, mark it as valid. */ \
184 msvc_inval_current->restart_valid = 1;
185 # define CATCH_MSVC_INVAL \
186 /* Execution completed. \
187 Mark gl_msvc_inval_restart as invalid. */ \
188 msvc_inval_current->restart_valid = 0; \
189 } \
190 else \
191 { \
192 /* Execution triggered an invalid parameter notification. \
193 Mark gl_msvc_inval_restart as invalid. */ \
194 msvc_inval_current->restart_valid = 0;
195 # define DONE_MSVC_INVAL \
196 } \
197 } \
198 while (0)
199
200 # endif
201
202 # endif
203
204 #else
205 /* A platform that does not need to the invalid parameter handler,
206 or when SANE_LIBRARY_HANDLING is desired. */
207
208 /* The braces here avoid GCC warnings like
209 "warning: suggest explicit braces to avoid ambiguous 'else'". */
210 # define TRY_MSVC_INVAL \
211 do \
212 { \
213 if (1)
214 # define CATCH_MSVC_INVAL \
215 else
216 # define DONE_MSVC_INVAL \
217 } \
218 while (0)
219
220 #endif
221
222 #endif /* _MSVC_INVAL_H */
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