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Diffstat (limited to 'lib/assert/assert.h')
| -rw-r--r-- | lib/assert/assert.h | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/lib/assert/assert.h b/lib/assert/assert.h new file mode 100644 index 0000000..fbdbd52 --- /dev/null +++ b/lib/assert/assert.h @@ -0,0 +1,98 @@ +/* + * Copyright (c) 2021 David Lamparter, for NetDEF, Inc. + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +/* WARNING: this file is "special" in that it overrides the system-provided + * assert.h by being on the include path before it. That means it should + * provide the functional equivalent. + * + * This is intentional because FRR extends assert() to write to the log and + * add backtraces. Overriding the entire file is the simplest and most + * reliable way to get this to work; there were problems previously with the + * system assert.h getting included afterwards and redefining assert() back to + * the system variant. + */ + +#ifndef _FRR_ASSERT_H +#define _FRR_ASSERT_H + +#include "xref.h" + +#ifdef __cplusplus +extern "C" { +#endif + +#ifndef __cplusplus +/* C++ has this built-in, but C provides it in assert.h for >=C11. Since we + * replace assert.h entirely, we need to provide it here too. + */ +#define static_assert _Static_assert +#endif + +struct xref_assert { + struct xref xref; + + const char *expr; + const char *extra, *args; +}; + +extern void _zlog_assert_failed(const struct xref_assert *xref, + const char *extra, ...) PRINTFRR(2, 3) + __attribute__((noreturn)); + +/* the "do { } while (expr_)" is there to get a warning for assignments inside + * the assert expression aka "assert(x = 1)". The (necessary) braces around + * expr_ in the if () statement would suppress these warnings. Since + * _zlog_assert_failed() is noreturn, the while condition will never be + * checked. + */ +#define assert(expr_) \ + ({ \ + static const struct xref_assert _xref __attribute__( \ + (used)) = { \ + .xref = XREF_INIT(XREFT_ASSERT, NULL, __func__), \ + .expr = #expr_, \ + }; \ + XREF_LINK(_xref.xref); \ + if (__builtin_expect((expr_) ? 0 : 1, 0)) \ + do { \ + _zlog_assert_failed(&_xref, NULL); \ + } while (expr_); \ + }) + +#define assertf(expr_, extra_, ...) \ + ({ \ + static const struct xref_assert _xref __attribute__( \ + (used)) = { \ + .xref = XREF_INIT(XREFT_ASSERT, NULL, __func__), \ + .expr = #expr_, \ + .extra = extra_, \ + .args = #__VA_ARGS__, \ + }; \ + XREF_LINK(_xref.xref); \ + if (__builtin_expect((expr_) ? 0 : 1, 0)) \ + do { \ + _zlog_assert_failed(&_xref, extra_, \ + ##__VA_ARGS__); \ + } while (expr_); \ + }) + +#define zassert assert + +#ifdef __cplusplus +} +#endif + +#endif /* _FRR_ASSERT_H */ |