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mirror of https://gitlab.nic.cz/labs/bird.git synced 2024-12-23 02:01:55 +00:00
bird/lib/birdlib.h
Maria Matejka 980ef11016 C Compiler Attribute Cleanup Test
There is a long-known CC attribute cleanup which allows to call a custom
cleanup function when an auto-storage variable ceases to exist. We're
gonna use it for end-of-loop and leave-locked-block macros.

This commit adds a static unit test for this compiler feature to be sure
that it really does what we want. We're looking forward to the next ISO
C norm where this may finally get a nice syntax and standardization.
2023-11-09 23:08:21 +01:00

234 lines
6.0 KiB
C

/*
* BIRD Library
*
* (c) 1998--2004 Martin Mares <mj@ucw.cz>
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
#ifndef _BIRD_BIRDLIB_H_
#define _BIRD_BIRDLIB_H_
#include "lib/alloca.h"
/* Ugly structure offset handling macros */
struct align_probe { char x; long int y; };
#define OFFSETOF(s, i) ((size_t) &((s *)0)->i)
#define SKIP_BACK(s, i, p) ((s *)((char *)p - OFFSETOF(s, i)))
#define BIRD_ALIGN(s, a) (((s)+a-1)&~(a-1))
#define CPU_STRUCT_ALIGN (sizeof(struct align_probe))
/* Utility macros */
#define MIN_(a,b) (((a)<(b))?(a):(b))
#define MAX_(a,b) (((a)>(b))?(a):(b))
#ifndef PARSER
#undef MIN
#undef MAX
#define MIN(a,b) MIN_(a,b)
#define MAX(a,b) MAX_(a,b)
#endif
#define ROUND_DOWN_POW2(a,b) ((a) & ~((b)-1))
#define ROUND_UP_POW2(a,b) (((a)+((b)-1)) & ~((b)-1))
#define U64(c) UINT64_C(c)
#define ABS(a) ((a)>=0 ? (a) : -(a))
#define DELTA(a,b) (((a)>=(b))?(a)-(b):(b)-(a))
#define ARRAY_SIZE(a) (sizeof(a)/sizeof(*(a)))
#define BYTES(n) ((((uint) (n)) + 7) / 8)
#define CALL(fn, args...) ({ if (fn) fn(args); })
#define ADVANCE(w, r, l) ({ r -= (l); w += (l); })
static inline int uint_cmp(uint i1, uint i2)
{ return (int)(i1 > i2) - (int)(i1 < i2); }
static inline int u64_cmp(u64 i1, u64 i2)
{ return (int)(i1 > i2) - (int)(i1 < i2); }
/* Bitfield macros */
/* b is u32 array (or ptr), l is size of it in bits (multiple of 32), p is 0..(l-1) */
#define BIT32_VAL(p) (((u32) 1) << ((p) % 32))
#define BIT32_TEST(b,p) ((b)[(p)/32] & BIT32_VAL(p))
#define BIT32_SET(b,p) ((b)[(p)/32] |= BIT32_VAL(p))
#define BIT32_CLR(b,p) ((b)[(p)/32] &= ~BIT32_VAL(p))
#define BIT32_ZERO(b,l) memset((b), 0, (l)/8)
/* The same, but counting bits from MSB */
#define BIT32R_VAL(p) ((((u32) 1) << 31) >> ((p) % 32))
#define BIT32R_TEST(b,p) ((b)[(p)/32] & BIT32R_VAL(p))
#define BIT32R_SET(b,p) ((b)[(p)/32] |= BIT32R_VAL(p))
#define BIT32R_CLR(b,p) ((b)[(p)/32] &= ~BIT32R_VAL(p))
#define BIT32R_ZERO(b,l) memset((b), 0, (l)/8)
#ifndef NULL
#define NULL ((void *) 0)
#endif
/* Macros for gcc attributes */
#define NORET __attribute__((noreturn))
#define UNUSED __attribute__((unused))
#define PACKED __attribute__((packed))
#define NONNULL(...) __attribute__((nonnull((__VA_ARGS__))))
#define CLEANUP(fun) __attribute__((cleanup(fun)))
#define STATIC_ASSERT(EXP) _Static_assert(EXP, #EXP)
#define STATIC_ASSERT_MSG(EXP,MSG) _Static_assert(EXP, MSG)
#ifndef HAVE_THREAD_LOCAL
#define _Thread_local
#endif
/* Microsecond time */
typedef s64 btime;
//typedef s64 bird_clock_t;
#define S_ * (btime) 1000000
#define MS_ * (btime) 1000
#define US_ * (btime) 1
#define TO_S /1000000
#define TO_MS /1000
#define TO_US /1
#ifndef PARSER
#define S S_
#define MS MS_
#define US US_
#define NS /1000
#endif
#define TIME_INFINITY ((s64) 0x7fffffffffffffff)
/* Rate limiting */
struct tbf {
btime timestamp; /* Last update */
u64 count; /* Available micro-tokens */
u16 burst; /* Max number of tokens */
u16 rate; /* Rate of replenishment (tokens / sec) */
u32 drop; /* Number of failed request since last successful */
};
/* Default TBF values for rate limiting log messages */
#define TBF_DEFAULT_LOG_LIMITS { .rate = 1, .burst = 5 }
int tbf_limit(struct tbf *f);
/* Logging and dying */
typedef struct buffer {
byte *start;
byte *pos;
byte *end;
} buffer;
#define STACK_BUFFER_INIT(buf,size) \
do { \
buf.start = alloca(size); \
buf.pos = buf.start; \
buf.end = buf.start + size; \
} while(0)
#define LOG_BUFFER_INIT(buf) \
STACK_BUFFER_INIT(buf, LOG_BUFFER_SIZE)
#define LOG_BUFFER_SIZE 1024
#define log log_msg
void log_commit(int class, buffer *buf);
void log_msg(const char *msg, ...);
void log_rl(struct tbf *rl, const char *msg, ...);
void die(const char *msg, ...) NORET;
void bug(const char *msg, ...) NORET;
#define L_DEBUG "\001" /* Debugging messages */
#define L_TRACE "\002" /* Protocol tracing */
#define L_INFO "\003" /* Informational messages */
#define L_REMOTE "\004" /* Remote protocol errors */
#define L_WARN "\005" /* Local warnings */
#define L_ERR "\006" /* Local errors */
#define L_AUTH "\007" /* Authorization failed etc. */
#define L_FATAL "\010" /* Fatal errors */
#define L_BUG "\011" /* BIRD bugs */
void debug(const char *msg, ...); /* Printf to debug output */
void debug_safe(const char *msg); /* Printf to debug output, async-safe */
/* Debugging */
#if defined(LOCAL_DEBUG) || defined(GLOBAL_DEBUG)
#define DBG(x, y...) debug(x, ##y)
#else
#define DBG(x, y...) do { } while(0)
#endif
#define ASSERT_DIE(x) do { if (!(x)) bug("Assertion '%s' failed at %s:%d", #x, __FILE__, __LINE__); } while(0)
#define EXPENSIVE_CHECK(x) /* intentionally left blank */
#ifdef DEBUGGING
#define ASSERT(x) ASSERT_DIE(x)
#define ASSUME(x) ASSERT_DIE(x)
#ifdef ENABLE_EXPENSIVE_CHECKS
#undef EXPENSIVE_CHECK
#define EXPENSIVE_CHECK(x) ASSERT_DIE(x)
#endif
#else
#define ASSERT(x) do { if (!(x)) log(L_BUG "Assertion '%s' failed at %s:%d", #x, __FILE__, __LINE__); } while(0)
#define ASSUME(x) /* intentionally left blank */
#endif
#ifdef DEBUGGING
asm(
".pushsection \".debug_gdb_scripts\", \"MS\",@progbits,1\n"
".byte 1\n" /* Python */
".asciz \"bird-gdb.py\"\n"
".popsection\n"
);
#endif
/* Pseudorandom numbers */
u32 random_u32(void);
void random_init(void);
void random_bytes(void *buf, size_t size);
/* Hashing */
/* Constant parameter for non-parametrized hashes */
#define HASH_PARAM 2902958171u
/* Precomputed powers of HASH_PARAM */
#define HASH_PARAM1 ((u64) HASH_PARAM)
#define HASH_PARAM2 (HASH_PARAM1 * HASH_PARAM)
#define HASH_PARAM3 (HASH_PARAM2 * HASH_PARAM)
#define HASH_PARAM4 (HASH_PARAM3 * HASH_PARAM)
/* Reduce intermediate 64-bit value to final 32-bit value */
static inline u32 hash_value(u64 a)
{ return ((u32) a) ^ ((u32) (a >> 32)); }
static inline u64 u32_hash0(u32 v, u32 p, u64 acc)
{ return (acc + v) * p; }
static inline u64 u64_hash0(u64 v, u32 p, u64 acc)
{ return u32_hash0(v >> 32, p, u32_hash0(v, p, acc)); }
static inline u32 u64_hash(u64 v)
{ return hash_value(u64_hash0(v, HASH_PARAM, 0)); }
#endif