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authorKristian Schuster <116557017+KriSchu@users.noreply.github.com>2023-02-19 22:49:18 (GMT)
committerKristian Schuster <116557017+KriSchu@users.noreply.github.com>2023-02-19 22:49:18 (GMT)
commita0d42777217296c0a7bdb1e1be8d8f6de1b24dd7 (patch)
tree8effe94c57b2f9796ba36090b07551baa8f1e1cb /gl/verify.h
parentca3d59cd6918c9e2739e783b721d4c1122640fd3 (diff)
parentc07206f2ccc2356aa74bc6813a94c2190017d44e (diff)
downloadmonitoring-plugins-a0d42777217296c0a7bdb1e1be8d8f6de1b24dd7.tar.gz
Merge remote-tracking branch 'origin/master' into feature_check_disk_add_ignore_missing_option
Diffstat (limited to 'gl/verify.h')
-rw-r--r--gl/verify.h191
1 files changed, 143 insertions, 48 deletions
diff --git a/gl/verify.h b/gl/verify.h
index d42d075..b63cb26 100644
--- a/gl/verify.h
+++ b/gl/verify.h
@@ -1,19 +1,19 @@
1/* Compile-time assert-like macros. 1/* Compile-time assert-like macros.
2 2
3 Copyright (C) 2005-2006, 2009-2013 Free Software Foundation, Inc. 3 Copyright (C) 2005-2006, 2009-2023 Free Software Foundation, Inc.
4 4
5 This program is free software: you can redistribute it and/or modify 5 This file is free software: you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by 6 it under the terms of the GNU Lesser General Public License as
7 the Free Software Foundation; either version 3 of the License, or 7 published by the Free Software Foundation; either version 2.1 of the
8 (at your option) any later version. 8 License, or (at your option) any later version.
9 9
10 This program is distributed in the hope that it will be useful, 10 This file is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of 11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details. 13 GNU Lesser General Public License for more details.
14 14
15 You should have received a copy of the GNU General Public License 15 You should have received a copy of the GNU Lesser General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 16 along with this program. If not, see <https://www.gnu.org/licenses/>. */
17 17
18/* Written by Paul Eggert, Bruno Haible, and Jim Meyering. */ 18/* Written by Paul Eggert, Bruno Haible, and Jim Meyering. */
19 19
@@ -21,31 +21,32 @@
21#define _GL_VERIFY_H 21#define _GL_VERIFY_H
22 22
23 23
24/* Define _GL_HAVE__STATIC_ASSERT to 1 if _Static_assert works as per C11. 24/* Define _GL_HAVE__STATIC_ASSERT to 1 if _Static_assert (R, DIAGNOSTIC)
25 This is supported by GCC 4.6.0 and later, in C mode, and its use 25 works as per C11. This is supported by GCC 4.6.0+ and by clang 4+.
26 here generates easier-to-read diagnostics when verify (R) fails.
27 26
28 Define _GL_HAVE_STATIC_ASSERT to 1 if static_assert works as per C++11. 27 Define _GL_HAVE__STATIC_ASSERT1 to 1 if _Static_assert (R) works as
29 This will likely be supported by future GCC versions, in C++ mode. 28 per C23. This is supported by GCC 9.1+.
30 29
31 Use this only with GCC. If we were willing to slow 'configure' 30 Support compilers claiming conformance to the relevant standard,
32 down we could also use it with other compilers, but since this 31 and also support GCC when not pedantic. If we were willing to slow
33 affects only the quality of diagnostics, why bother? */ 32 'configure' down we could also use it with other compilers, but
34#if (4 < __GNUC__ + (6 <= __GNUC_MINOR__) \ 33 since this affects only the quality of diagnostics, why bother? */
35 && (201112L <= __STDC_VERSION__ || !defined __STRICT_ANSI__) \ 34#ifndef __cplusplus
36 && !defined __cplusplus) 35# if (201112 <= __STDC_VERSION__ \
37# define _GL_HAVE__STATIC_ASSERT 1 36 || (!defined __STRICT_ANSI__ \
38#endif 37 && (4 < __GNUC__ + (6 <= __GNUC_MINOR__) || 5 <= __clang_major__)))
39/* The condition (99 < __GNUC__) is temporary, until we know about the 38# define _GL_HAVE__STATIC_ASSERT 1
40 first G++ release that supports static_assert. */ 39# endif
41#if (99 < __GNUC__) && defined __cplusplus 40# if (202311 <= __STDC_VERSION__ \
42# define _GL_HAVE_STATIC_ASSERT 1 41 || (!defined __STRICT_ANSI__ && 9 <= __GNUC__))
42# define _GL_HAVE__STATIC_ASSERT1 1
43# endif
43#endif 44#endif
44 45
45/* FreeBSD 9.1 <sys/cdefs.h>, included by <stddef.h> and lots of other 46/* FreeBSD 9.1 <sys/cdefs.h>, included by <stddef.h> and lots of other
46 system headers, defines a conflicting _Static_assert that is no 47 system headers, defines a conflicting _Static_assert that is no
47 better than ours; override it. */ 48 better than ours; override it. */
48#ifndef _GL_HAVE_STATIC_ASSERT 49#ifndef _GL_HAVE__STATIC_ASSERT
49# include <stddef.h> 50# include <stddef.h>
50# undef _Static_assert 51# undef _Static_assert
51#endif 52#endif
@@ -143,9 +144,9 @@
143 which do not support _Static_assert, also do not warn about the 144 which do not support _Static_assert, also do not warn about the
144 last declaration mentioned above. 145 last declaration mentioned above.
145 146
146 * GCC warns if -Wnested-externs is enabled and verify() is used 147 * GCC warns if -Wnested-externs is enabled and 'verify' is used
147 within a function body; but inside a function, you can always 148 within a function body; but inside a function, you can always
148 arrange to use verify_expr() instead. 149 arrange to use verify_expr instead.
149 150
150 * In C++, any struct definition inside sizeof is invalid. 151 * In C++, any struct definition inside sizeof is invalid.
151 Use a template type to work around the problem. */ 152 Use a template type to work around the problem. */
@@ -197,48 +198,95 @@ template <int w>
197#endif 198#endif
198 199
199/* Verify requirement R at compile-time, as a declaration without a 200/* Verify requirement R at compile-time, as a declaration without a
200 trailing ';'. If R is false, fail at compile-time, preferably 201 trailing ';'. If R is false, fail at compile-time.
201 with a diagnostic that includes the string-literal DIAGNOSTIC. 202
203 This macro requires three or more arguments but uses at most the first
204 two, so that the _Static_assert macro optionally defined below supports
205 both the C11 two-argument syntax and the C23 one-argument syntax.
202 206
203 Unfortunately, unlike C11, this implementation must appear as an 207 Unfortunately, unlike C11, this implementation must appear as an
204 ordinary declaration, and cannot appear inside struct { ... }. */ 208 ordinary declaration, and cannot appear inside struct { ... }. */
205 209
206#ifdef _GL_HAVE__STATIC_ASSERT 210#if 202311 <= __STDC_VERSION__ || 200410 <= __cpp_static_assert
207# define _GL_VERIFY _Static_assert 211# define _GL_VERIFY(R, DIAGNOSTIC, ...) static_assert (R, DIAGNOSTIC)
212#elif defined _GL_HAVE__STATIC_ASSERT
213# define _GL_VERIFY(R, DIAGNOSTIC, ...) _Static_assert (R, DIAGNOSTIC)
208#else 214#else
209# define _GL_VERIFY(R, DIAGNOSTIC) \ 215# define _GL_VERIFY(R, DIAGNOSTIC, ...) \
210 extern int (*_GL_GENSYM (_gl_verify_function) (void)) \ 216 extern int (*_GL_GENSYM (_gl_verify_function) (void)) \
211 [_GL_VERIFY_TRUE (R, DIAGNOSTIC)] 217 [_GL_VERIFY_TRUE (R, DIAGNOSTIC)]
218# if 4 < __GNUC__ + (6 <= __GNUC_MINOR__)
219# pragma GCC diagnostic ignored "-Wnested-externs"
220# endif
212#endif 221#endif
213 222
214/* _GL_STATIC_ASSERT_H is defined if this code is copied into assert.h. */ 223/* _GL_STATIC_ASSERT_H is defined if this code is copied into assert.h. */
215#ifdef _GL_STATIC_ASSERT_H 224#ifdef _GL_STATIC_ASSERT_H
216# if !defined _GL_HAVE__STATIC_ASSERT && !defined _Static_assert 225# if !defined _GL_HAVE__STATIC_ASSERT1 && !defined _Static_assert
217# define _Static_assert(R, DIAGNOSTIC) _GL_VERIFY (R, DIAGNOSTIC) 226# if !defined _MSC_VER || defined __clang__
227# define _Static_assert(...) \
228 _GL_VERIFY (__VA_ARGS__, "static assertion failed", -)
229# else
230 /* Work around MSVC preprocessor incompatibility with ISO C; see
231 <https://stackoverflow.com/questions/5134523/>. */
232# define _Static_assert(R, ...) \
233 _GL_VERIFY ((R), "static assertion failed", -)
234# endif
218# endif 235# endif
219# if !defined _GL_HAVE_STATIC_ASSERT && !defined static_assert 236# if (!defined static_assert \
220# define static_assert _Static_assert /* C11 requires this #define. */ 237 && __STDC_VERSION__ < 202311 \
238 && (!defined __cplusplus \
239 || (__cpp_static_assert < 201411 \
240 && __GNUG__ < 6 && __clang_major__ < 6)))
241# if defined __cplusplus && _MSC_VER >= 1900 && !defined __clang__
242/* MSVC 14 in C++ mode supports the two-arguments static_assert but not
243 the one-argument static_assert, and it does not support _Static_assert.
244 We have to play preprocessor tricks to distinguish the two cases.
245 Since the MSVC preprocessor is not ISO C compliant (see above),.
246 the solution is specific to MSVC. */
247# define _GL_EXPAND(x) x
248# define _GL_SA1(a1) static_assert ((a1), "static assertion failed")
249# define _GL_SA2 static_assert
250# define _GL_SA3 static_assert
251# define _GL_SA_PICK(x1,x2,x3,x4,...) x4
252# define static_assert(...) _GL_EXPAND(_GL_SA_PICK(__VA_ARGS__,_GL_SA3,_GL_SA2,_GL_SA1)) (__VA_ARGS__)
253# else
254# define static_assert _Static_assert /* C11 requires this #define. */
255# endif
221# endif 256# endif
222#endif 257#endif
223 258
224/* @assert.h omit start@ */ 259/* @assert.h omit start@ */
225 260
261#if defined __clang_major__ && __clang_major__ < 5
262# define _GL_HAS_BUILTIN_TRAP 0
263#elif 3 < __GNUC__ + (3 < __GNUC_MINOR__ + (4 <= __GNUC_PATCHLEVEL__))
264# define _GL_HAS_BUILTIN_TRAP 1
265#elif defined __has_builtin
266# define _GL_HAS_BUILTIN_TRAP __has_builtin (__builtin_trap)
267#else
268# define _GL_HAS_BUILTIN_TRAP 0
269#endif
270
271#if defined __clang_major__ && __clang_major__ < 5
272# define _GL_HAS_BUILTIN_UNREACHABLE 0
273#elif 4 < __GNUC__ + (5 <= __GNUC_MINOR__)
274# define _GL_HAS_BUILTIN_UNREACHABLE 1
275#elif defined __has_builtin
276# define _GL_HAS_BUILTIN_UNREACHABLE __has_builtin (__builtin_unreachable)
277#else
278# define _GL_HAS_BUILTIN_UNREACHABLE 0
279#endif
280
226/* Each of these macros verifies that its argument R is nonzero. To 281/* Each of these macros verifies that its argument R is nonzero. To
227 be portable, R should be an integer constant expression. Unlike 282 be portable, R should be an integer constant expression. Unlike
228 assert (R), there is no run-time overhead. 283 assert (R), there is no run-time overhead.
229 284
230 There are two macros, since no single macro can be used in all 285 There are two macros, since no single macro can be used in all
231 contexts in C. verify_true (R) is for scalar contexts, including 286 contexts in C. verify_expr (R, E) is for scalar contexts, including
232 integer constant expression contexts. verify (R) is for declaration 287 integer constant expression contexts. verify (R) is for declaration
233 contexts, e.g., the top level. */ 288 contexts, e.g., the top level. */
234 289
235/* Verify requirement R at compile-time, as an integer constant expression.
236 Return 1. This is equivalent to verify_expr (R, 1).
237
238 verify_true is obsolescent; please use verify_expr instead. */
239
240#define verify_true(R) _GL_VERIFY_TRUE (R, "verify_true (" #R ")")
241
242/* Verify requirement R at compile-time. Return the value of the 290/* Verify requirement R at compile-time. Return the value of the
243 expression E. */ 291 expression E. */
244 292
@@ -246,9 +294,56 @@ template <int w>
246 (_GL_VERIFY_TRUE (R, "verify_expr (" #R ", " #E ")") ? (E) : (E)) 294 (_GL_VERIFY_TRUE (R, "verify_expr (" #R ", " #E ")") ? (E) : (E))
247 295
248/* Verify requirement R at compile-time, as a declaration without a 296/* Verify requirement R at compile-time, as a declaration without a
249 trailing ';'. */ 297 trailing ';'. verify (R) acts like static_assert (R) except that
298 it is portable to C11/C++14 and earlier, it can issue better
299 diagnostics, and its name is shorter and may be more convenient. */
300
301#ifdef __PGI
302/* PGI barfs if R is long. */
303# define verify(R) _GL_VERIFY (R, "verify (...)", -)
304#else
305# define verify(R) _GL_VERIFY (R, "verify (" #R ")", -)
306#endif
250 307
251#define verify(R) _GL_VERIFY (R, "verify (" #R ")") 308/* Assume that R always holds. Behavior is undefined if R is false,
309 fails to evaluate, or has side effects.
310
311 'assume (R)' is a directive from the programmer telling the
312 compiler that R is true so the compiler needn't generate code to
313 test R. This is why 'assume' is in verify.h: it's related to
314 static checking (in this case, static checking done by the
315 programmer), not dynamic checking.
316
317 'assume (R)' can affect compilation of all the code, not just code
318 that happens to be executed after the assume (R) is "executed".
319 For example, if the code mistakenly does 'assert (R); assume (R);'
320 the compiler is entitled to optimize away the 'assert (R)'.
321
322 Although assuming R can help a compiler generate better code or
323 diagnostics, performance can suffer if R uses hard-to-optimize
324 features such as function calls not inlined by the compiler.
325
326 Avoid Clang's __builtin_assume, as it breaks GNU Emacs master
327 as of 2020-08-23T21:09:49Z!eggert@cs.ucla.edu; see
328 <https://bugs.gnu.org/43152#71>. It's not known whether this breakage
329 is a Clang bug or an Emacs bug; play it safe for now. */
330
331#if _GL_HAS_BUILTIN_UNREACHABLE
332# define assume(R) ((R) ? (void) 0 : __builtin_unreachable ())
333#elif 1200 <= _MSC_VER
334# define assume(R) __assume (R)
335#elif 202311 <= __STDC_VERSION__
336# include <stddef.h>
337# define assume(R) ((R) ? (void) 0 : unreachable ())
338#elif (defined GCC_LINT || defined lint) && _GL_HAS_BUILTIN_TRAP
339 /* Doing it this way helps various packages when configured with
340 --enable-gcc-warnings, which compiles with -Dlint. It's nicer
341 if 'assume' silences warnings with GCC 3.4 through GCC 4.4.7 (2012). */
342# define assume(R) ((R) ? (void) 0 : __builtin_trap ())
343#else
344 /* Some older tools grok NOTREACHED, e.g., Oracle Studio 12.6 (2017). */
345# define assume(R) ((R) ? (void) 0 : /*NOTREACHED*/ (void) 0)
346#endif
252 347
253/* @assert.h omit end@ */ 348/* @assert.h omit end@ */
254 349