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bind9/lib/isc/include/isc/util.h
2024-04-23 13:11:52 +02:00

412 lines
15 KiB
C

/*
* Copyright (C) Internet Systems Consortium, Inc. ("ISC")
*
* SPDX-License-Identifier: MPL-2.0
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, you can obtain one at https://mozilla.org/MPL/2.0/.
*
* See the COPYRIGHT file distributed with this work for additional
* information regarding copyright ownership.
*/
#pragma once
#include <inttypes.h>
/*! \file isc/util.h
* NOTE:
*
* This file is not to be included from any <isc/???.h> (or other) library
* files.
*
* \brief
* Including this file puts several macros in your name space that are
* not protected (as all the other ISC functions/macros do) by prepending
* ISC_ or isc_ to the name.
*/
#include <isc/attributes.h>
/***
*** Clang Compatibility Macros
***/
#if !defined(__has_feature)
#define __has_feature(x) 0
#endif /* if !defined(__has_feature) */
/***
*** General Macros.
***/
/*%
* Legacy way how to hide unused function arguments, don't use in
* the new code, rather use the ISC_ATTR_UNUSED macro that expands
* to either C23's [[maybe_unused]] or __attribute__((__unused__)).
*
* \code
* int
* foo(ISC_ATTR_UNUSED char *bar) {
* ...;
* }
* \endcode
*/
#define UNUSED(x) (void)(x)
#if __GNUC__ >= 8 && !defined(__clang__)
#define ISC_NONSTRING __attribute__((nonstring))
#else /* if __GNUC__ >= 8 && !defined(__clang__) */
#define ISC_NONSTRING
#endif /* __GNUC__ */
#if HAVE_FUNC_ATTRIBUTE_CONSTRUCTOR && HAVE_FUNC_ATTRIBUTE_DESTRUCTOR
#define ISC_CONSTRUCTOR __attribute__((constructor))
#define ISC_DESTRUCTOR __attribute__((destructor))
#else
#define ISC_CONSTRUCTOR
#define ISC_DESTRUCTOR
#endif
/*%
* The opposite: silent warnings about stored values which are never read.
*/
#define POST(x) (void)(x)
#define ISC_MAX(a, b) ((a) > (b) ? (a) : (b))
#define ISC_MIN(a, b) ((a) < (b) ? (a) : (b))
#define ISC_CLAMP(v, x, y) ((v) < (x) ? (x) : ((v) > (y) ? (y) : (v)))
/*%
* The UNCONST() macro can be used to omit warnings produced by certain
* compilers when operating with pointers declared with the const type qual-
* ifier in a context without such qualifier. Examples include passing a
* pointer declared with the const qualifier to a function without such
* qualifier, and variable assignment from a const pointer to a non-const
* pointer.
*
* As the macro may hide valid errors, their usage is not recommended
* unless there is a well-thought reason for a cast. A typical use case for
* __UNCONST() involve an API that does not follow the so-called ``const
* correctness'' even if it would be appropriate.
*/
#define UNCONST(ptr) ((void *)(uintptr_t)(ptr))
#define ARRAY_SIZE(x) (sizeof(x) / sizeof(x[0]))
/*
* Optional return values, or out-arguments
*/
#define SET_IF_NOT_NULL(obj, val) \
if ((obj) != NULL) { \
*(obj) = (val); \
}
/*%
* Get the allocation size for a struct with a flexible array member
* containing `count` elements. The struct is identified by a pointer,
* typically the one that points to (or will point to) the allocation.
*/
#define STRUCT_FLEX_SIZE(pointer, member, count) \
(sizeof(*(pointer)) + sizeof(*(pointer)->member) * (count))
/*%
* Use this in translation units that would otherwise be empty, to
* suppress compiler warnings.
*/
#define EMPTY_TRANSLATION_UNIT extern int isc__empty;
/*%
* We use macros instead of calling the routines directly because
* the capital letters make the locking stand out.
*/
#ifdef ISC_UTIL_TRACEON
#define ISC_UTIL_TRACE(a) a
#include <stdio.h> /* Required for fprintf/stderr when tracing. */
#else /* ifdef ISC_UTIL_TRACEON */
#define ISC_UTIL_TRACE(a)
#endif /* ifdef ISC_UTIL_TRACEON */
#include <isc/result.h> /* Contractual promise. */
#define SPINLOCK(sp) \
{ \
ISC_UTIL_TRACE(fprintf(stderr, "SPINLOCKING %p %s %d\n", (sp), \
__FILE__, __LINE__)); \
isc_spinlock_lock((sp)); \
ISC_UTIL_TRACE(fprintf(stderr, "SPINLOCKED %p %s %d\n", (sp), \
__FILE__, __LINE__)); \
}
#define SPINUNLOCK(sp) \
{ \
isc_spinlock_unlock((sp)); \
ISC_UTIL_TRACE(fprintf(stderr, "SPINUNLOCKED %p %s %d\n", \
(sp), __FILE__, __LINE__)); \
}
#define LOCK(lp) \
{ \
ISC_UTIL_TRACE(fprintf(stderr, "LOCKING %p %s %d\n", (lp), \
__FILE__, __LINE__)); \
isc_mutex_lock((lp)); \
ISC_UTIL_TRACE(fprintf(stderr, "LOCKED %p %s %d\n", (lp), \
__FILE__, __LINE__)); \
}
#define UNLOCK(lp) \
{ \
isc_mutex_unlock((lp)); \
ISC_UTIL_TRACE(fprintf(stderr, "UNLOCKED %p %s %d\n", (lp), \
__FILE__, __LINE__)); \
}
#define BROADCAST(cvp) \
{ \
ISC_UTIL_TRACE(fprintf(stderr, "BROADCAST %p %s %d\n", (cvp), \
__FILE__, __LINE__)); \
isc_condition_broadcast((cvp)); \
}
#define SIGNAL(cvp) \
{ \
ISC_UTIL_TRACE(fprintf(stderr, "SIGNAL %p %s %d\n", (cvp), \
__FILE__, __LINE__)); \
isc_condition_signal((cvp)); \
}
#define WAIT(cvp, lp) \
{ \
ISC_UTIL_TRACE(fprintf(stderr, "WAIT %p LOCK %p %s %d\n", \
(cvp), (lp), __FILE__, __LINE__)); \
isc_condition_wait((cvp), (lp)); \
ISC_UTIL_TRACE(fprintf(stderr, "WAITED %p LOCKED %p %s %d\n", \
(cvp), (lp), __FILE__, __LINE__)); \
}
/*
* isc_condition_waituntil can return ISC_R_TIMEDOUT, so we
* don't RUNTIME_CHECK the result.
*
* XXX Also, can't really debug this then...
*/
#define WAITUNTIL(cvp, lp, tp) isc_condition_waituntil((cvp), (lp), (tp))
#define RWLOCK(lp, t) \
{ \
ISC_UTIL_TRACE(fprintf(stderr, "RWLOCK %p, %d %s %d\n", (lp), \
(t), __FILE__, __LINE__)); \
isc_rwlock_lock((lp), (t)); \
ISC_UTIL_TRACE(fprintf(stderr, "RWLOCKED %p, %d %s %d\n", \
(lp), (t), __FILE__, __LINE__)); \
}
#define RWUNLOCK(lp, t) \
{ \
ISC_UTIL_TRACE(fprintf(stderr, "RWUNLOCK %p, %d %s %d\n", \
(lp), (t), __FILE__, __LINE__)); \
isc_rwlock_unlock((lp), (t)); \
}
#define RDLOCK(lp) RWLOCK(lp, isc_rwlocktype_read)
#define RDUNLOCK(lp) RWUNLOCK(lp, isc_rwlocktype_read)
#define WRLOCK(lp) RWLOCK(lp, isc_rwlocktype_write)
#define WRUNLOCK(lp) RWUNLOCK(lp, isc_rwlocktype_write)
#define UPGRADELOCK(lock, locktype) \
{ \
if (locktype == isc_rwlocktype_read) { \
if (isc_rwlock_tryupgrade(lock) == ISC_R_SUCCESS) { \
locktype = isc_rwlocktype_write; \
} else { \
RWUNLOCK(lock, locktype); \
locktype = isc_rwlocktype_write; \
RWLOCK(lock, locktype); \
} \
} \
INSIST(locktype == isc_rwlocktype_write); \
}
/*
* List Macros.
*/
#include <isc/list.h> /* Contractual promise. */
#define LIST(type) ISC_LIST(type)
#define INIT_LIST(type) ISC_LIST_INIT(type)
#define LINK(type) ISC_LINK(type)
#define INIT_LINK(elt, link) ISC_LINK_INIT(elt, link)
#define HEAD(list) ISC_LIST_HEAD(list)
#define TAIL(list) ISC_LIST_TAIL(list)
#define EMPTY(list) ISC_LIST_EMPTY(list)
#define PREV(elt, link) ISC_LIST_PREV(elt, link)
#define NEXT(elt, link) ISC_LIST_NEXT(elt, link)
#define APPEND(list, elt, link) ISC_LIST_APPEND(list, elt, link)
#define PREPEND(list, elt, link) ISC_LIST_PREPEND(list, elt, link)
#define UNLINK(list, elt, link) ISC_LIST_UNLINK(list, elt, link)
#define ENQUEUE(list, elt, link) ISC_LIST_APPEND(list, elt, link)
#define DEQUEUE(list, elt, link) ISC_LIST_UNLINK(list, elt, link)
#define INSERTBEFORE(li, b, e, ln) ISC_LIST_INSERTBEFORE(li, b, e, ln)
#define INSERTAFTER(li, a, e, ln) ISC_LIST_INSERTAFTER(li, a, e, ln)
#define APPENDLIST(list1, list2, link) ISC_LIST_APPENDLIST(list1, list2, link)
/*%
* Performance
*/
/* GCC defines __SANITIZE_ADDRESS__, so reuse the macro for clang */
#if __has_feature(address_sanitizer)
#define __SANITIZE_ADDRESS__ 1
#endif /* if __has_feature(address_sanitizer) */
#if __SANITIZE_ADDRESS__
#define ISC_NO_SANITIZE_ADDRESS __attribute__((no_sanitize("address")))
#else /* if __SANITIZE_ADDRESS__ */
#define ISC_NO_SANITIZE_ADDRESS
#endif /* if __SANITIZE_ADDRESS__ */
#if __has_feature(thread_sanitizer)
#define __SANITIZE_THREAD__ 1
#endif /* if __has_feature(thread_sanitizer) */
#if __SANITIZE_THREAD__
#define ISC_NO_SANITIZE_THREAD __attribute__((no_sanitize("thread")))
#else /* if __SANITIZE_THREAD__ */
#define ISC_NO_SANITIZE_THREAD
#endif /* if __SANITIZE_THREAD__ */
#if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR >= 6)
#define STATIC_ASSERT(cond, msg) _Static_assert(cond, msg)
#elif __has_feature(c_static_assert)
#define STATIC_ASSERT(cond, msg) _Static_assert(cond, msg)
#else /* if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR >= 6) */
/* Courtesy of Joseph Quinsey: https://godbolt.org/z/K9RvWS */
#define TOKENPASTE(a, b) a##b /* "##" is the "Token Pasting Operator" */
#define EXPAND_THEN_PASTE(a, b) TOKENPASTE(a, b) /* expand then paste */
#define STATIC_ASSERT(x, msg) \
enum { EXPAND_THEN_PASTE(ASSERT_line_, __LINE__) = 1 / ((msg) && (x)) }
#endif /* if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR >= 6) */
#ifdef UNIT_TESTING
extern void
mock_assert(const int result, const char *const expression,
const char *const file, const int line);
/*
* Allow clang to determine that the following code is not reached
* by calling abort() if the condition fails. The abort() will
* never be executed as mock_assert() and _assert_true() longjmp
* or exit if the condition is false.
*/
#define REQUIRE(expression) \
((!(expression)) \
? (mock_assert(0, #expression, __FILE__, __LINE__), abort()) \
: (void)0)
#define ENSURE(expression) \
((!(int)(expression)) \
? (mock_assert(0, #expression, __FILE__, __LINE__), abort()) \
: (void)0)
#define INSIST(expression) \
((!(expression)) \
? (mock_assert(0, #expression, __FILE__, __LINE__), abort()) \
: (void)0)
#define INVARIANT(expression) \
((!(expression)) \
? (mock_assert(0, #expression, __FILE__, __LINE__), abort()) \
: (void)0)
#define UNREACHABLE() \
(mock_assert(0, "unreachable", __FILE__, __LINE__), abort())
#define _assert_true(c, e, f, l) \
((c) ? (void)0 : (_assert_true(0, e, f, l), abort()))
#define _assert_int_equal(a, b, f, l) \
(((a) == (b)) ? (void)0 : (_assert_int_equal(a, b, f, l), abort()))
#define _assert_int_not_equal(a, b, f, l) \
(((a) != (b)) ? (void)0 : (_assert_int_not_equal(a, b, f, l), abort()))
#else /* UNIT_TESTING */
/*
* Assertions
*/
#include <isc/assertions.h> /* Contractual promise. */
/*% Require Assertion */
#define REQUIRE(e) ISC_REQUIRE(e)
/*% Ensure Assertion */
#define ENSURE(e) ISC_ENSURE(e)
/*% Insist Assertion */
#define INSIST(e) ISC_INSIST(e)
/*% Invariant Assertion */
#define INVARIANT(e) ISC_INVARIANT(e)
#define UNREACHABLE() ISC_UNREACHABLE()
#endif /* UNIT_TESTING */
/*
* Errors
*/
#include <errno.h> /* for errno */
#include <isc/error.h> /* Contractual promise. */
#include <isc/strerr.h> /* for ISC_STRERRORSIZE */
#define UNEXPECTED_ERROR(...) \
isc_error_unexpected(__FILE__, __LINE__, __func__, __VA_ARGS__)
#define FATAL_ERROR(...) \
isc_error_fatal(__FILE__, __LINE__, __func__, __VA_ARGS__)
#define REPORT_SYSERROR(report, err, fmt, ...) \
{ \
char strerr[ISC_STRERRORSIZE]; \
strerror_r(err, strerr, sizeof(strerr)); \
report(__FILE__, __LINE__, __func__, fmt ": %s (%d)", \
##__VA_ARGS__, strerr, err); \
}
#define UNEXPECTED_SYSERROR(err, ...) \
REPORT_SYSERROR(isc_error_unexpected, err, __VA_ARGS__)
#define FATAL_SYSERROR(err, ...) \
REPORT_SYSERROR(isc_error_fatal, err, __VA_ARGS__)
#ifdef UNIT_TESTING
#define RUNTIME_CHECK(cond) \
((cond) ? (void)0 \
: (mock_assert(0, #cond, __FILE__, __LINE__), abort()))
#else /* UNIT_TESTING */
#define RUNTIME_CHECK(cond) \
((cond) ? (void)0 : FATAL_ERROR("RUNTIME_CHECK(%s) failed", #cond))
#endif /* UNIT_TESTING */
/*%
* Runtime check which logs the error value returned by a POSIX Threads
* function and the error string that corresponds to it
*/
#define PTHREADS_RUNTIME_CHECK(func, ret) \
if ((ret) != 0) { \
FATAL_SYSERROR(ret, "%s()", #func); \
}
/*%
* Alignment
*/
#ifdef __GNUC__
#define ISC_ALIGN(x, a) (((x) + (a) - 1) & ~((typeof(x))(a) - 1))
#else /* ifdef __GNUC__ */
#define ISC_ALIGN(x, a) (((x) + (a) - 1) & ~((uintmax_t)(a) - 1))
#endif /* ifdef __GNUC__ */
/*%
* Swap
*/
#define ISC_SWAP(a, b) \
{ \
typeof(a) __tmp_swap = a; \
a = b; \
b = __tmp_swap; \
}