Port: Add Cygwin tid support to logging

[babeltrace.git] / logging / log.c

/*
 * This is zf_log.c, modified with Babeltrace prefixes.
 * See <https://github.com/wonder-mice/zf_log/>.
 * See LICENSE.
 */

#include <babeltrace/babeltrace-internal.h>
#include <babeltrace/common-internal.h>

#ifdef __CYGWIN__
extern unsigned long pthread_getsequence_np(pthread_t *);
#endif

/* When defined, Android log (android/log.h) will be used by default instead of
 * stderr (ignored on non-Android platforms). Date, time, pid and tid (context)
 * will be provided by Android log. Android log features will be used to output
 * log level and tag.
 */
#ifdef BT_LOG_USE_ANDROID_LOG
        #undef BT_LOG_USE_ANDROID_LOG
        #if defined(__ANDROID__)
                #define BT_LOG_USE_ANDROID_LOG 1
        #else
                #define BT_LOG_USE_ANDROID_LOG 0
        #endif
#else
        #define BT_LOG_USE_ANDROID_LOG 0
#endif
/* When defined, NSLog (uses Apple System Log) will be used instead of stderr
 * (ignored on non-Apple platforms). Date, time, pid and tid (context) will be
 * provided by NSLog. Curiously, doesn't use NSLog() directly, but piggybacks on
 * non-public CFLog() function. Both use Apple System Log internally, but it's
 * easier to call CFLog() from C than NSLog(). Current implementation doesn't
 * support "%@" format specifier.
 */
#ifdef BT_LOG_USE_NSLOG
        #undef BT_LOG_USE_NSLOG
        #if defined(__APPLE__) && defined(__MACH__)
                #define BT_LOG_USE_NSLOG 1
        #else
                #define BT_LOG_USE_NSLOG 0
        #endif
#else
        #define BT_LOG_USE_NSLOG 0
#endif
/* When defined, OutputDebugString() will be used instead of stderr (ignored on
 * non-Windows platforms). Uses OutputDebugStringA() variant and feeds it with
 * UTF-8 data.
 */
#ifdef BT_LOG_USE_DEBUGSTRING
        #undef BT_LOG_USE_DEBUGSTRING
        #if defined(_WIN32) || defined(_WIN64)
                #define BT_LOG_USE_DEBUGSTRING 1
        #else
                #define BT_LOG_USE_DEBUGSTRING 0
        #endif
#else
        #define BT_LOG_USE_DEBUGSTRING 0
#endif
/* When defined, bt_log library will not contain definition of tag prefix
 * variable. In that case it must be defined elsewhere using
 * BT_LOG_DEFINE_TAG_PREFIX macro, for example:
 *
 *   BT_LOG_DEFINE_TAG_PREFIX = "ProcessName";
 *
 * This allows to specify custom value for static initialization and avoid
 * overhead of setting this value in runtime.
 */
#ifdef BT_LOG_EXTERN_TAG_PREFIX
        #undef BT_LOG_EXTERN_TAG_PREFIX
        #define BT_LOG_EXTERN_TAG_PREFIX 1
#else
        #define BT_LOG_EXTERN_TAG_PREFIX 0
#endif
/* When defined, bt_log library will not contain definition of global format
 * variable. In that case it must be defined elsewhere using
 * BT_LOG_DEFINE_GLOBAL_FORMAT macro, for example:
 *
 *   BT_LOG_DEFINE_GLOBAL_FORMAT = {MEM_WIDTH};
 *
 * This allows to specify custom value for static initialization and avoid
 * overhead of setting this value in runtime.
 */
#ifdef BT_LOG_EXTERN_GLOBAL_FORMAT
        #undef BT_LOG_EXTERN_GLOBAL_FORMAT
        #define BT_LOG_EXTERN_GLOBAL_FORMAT 1
#else
        #define BT_LOG_EXTERN_GLOBAL_FORMAT 0
#endif
/* When defined, bt_log library will not contain definition of global output
 * variable. In that case it must be defined elsewhere using
 * BT_LOG_DEFINE_GLOBAL_OUTPUT macro, for example:
 *
 *   BT_LOG_DEFINE_GLOBAL_OUTPUT = {BT_LOG_PUT_STD, custom_output_callback};
 *
 * This allows to specify custom value for static initialization and avoid
 * overhead of setting this value in runtime.
 */
#ifdef BT_LOG_EXTERN_GLOBAL_OUTPUT
        #undef BT_LOG_EXTERN_GLOBAL_OUTPUT
        #define BT_LOG_EXTERN_GLOBAL_OUTPUT 1
#else
        #define BT_LOG_EXTERN_GLOBAL_OUTPUT 0
#endif
/* When defined, bt_log library will not contain definition of global output
 * level variable. In that case it must be defined elsewhere using
 * BT_LOG_DEFINE_GLOBAL_OUTPUT_LEVEL macro, for example:
 *
 *   BT_LOG_DEFINE_GLOBAL_OUTPUT_LEVEL = BT_LOG_WARN;
 *
 * This allows to specify custom value for static initialization and avoid
 * overhead of setting this value in runtime.
 */
#ifdef BT_LOG_EXTERN_GLOBAL_OUTPUT_LEVEL
        #undef BT_LOG_EXTERN_GLOBAL_OUTPUT_LEVEL
        #define BT_LOG_EXTERN_GLOBAL_OUTPUT_LEVEL 1
#else
        #define BT_LOG_EXTERN_GLOBAL_OUTPUT_LEVEL 0
#endif
/* When defined, implementation will prefer smaller code size over speed.
 * Very rough estimate is that code will be up to 2x smaller and up to 2x
 * slower. Disabled by default.
 */
#ifdef BT_LOG_OPTIMIZE_SIZE
        #undef BT_LOG_OPTIMIZE_SIZE
        #define BT_LOG_OPTIMIZE_SIZE 1
#else
        #define BT_LOG_OPTIMIZE_SIZE 0
#endif
/* Size of the log line buffer. The buffer is allocated on stack. It limits
 * maximum length of a log line.
 */
#ifndef BT_LOG_BUF_SZ
        #define BT_LOG_BUF_SZ 512
#endif
/* Default number of bytes in one line of memory output. For large values
 * BT_LOG_BUF_SZ also must be increased.
 */
#ifndef BT_LOG_MEM_WIDTH
        #define BT_LOG_MEM_WIDTH 32
#endif
/* String to put in the end of each log line (can be empty). Its value used by
 * stderr output callback. Its size used as a default value for BT_LOG_EOL_SZ.
 */
#ifndef BT_LOG_EOL
        #define BT_LOG_EOL "\n"
#endif
/* Default delimiter that separates parts of log message. Can NOT contain '%'
 * or '\0'.
 *
 * Log message format specifications can override (or ignore) this value. For
 * more details see BT_LOG_MESSAGE_CTX_FORMAT, BT_LOG_MESSAGE_SRC_FORMAT and
 * BT_LOG_MESSAGE_TAG_FORMAT.
 */
#ifndef BT_LOG_DEF_DELIMITER
        #define BT_LOG_DEF_DELIMITER " "
#endif
/* Specifies log message context format. Log message context includes date,
 * time, process id, thread id and message's log level. Custom information can
 * be added as well. Supported fields: YEAR, MONTH, DAY, HOUR, MINUTE, SECOND,
 * MILLISECOND, PID, TID, LEVEL, S(str), F_INIT(statements),
 * F_UINT(width, value).
 *
 * Must be defined as a tuple, for example:
 *
 *   #define BT_LOG_MESSAGE_CTX_FORMAT (YEAR, S("."), MONTH, S("."), DAY, S(" > "))
 *
 * In that case, resulting log message will be:
 *
 *   2016.12.22 > TAG function@filename.c:line Message text
 *
 * Note, that tag, source location and message text are not impacted by
 * this setting. See BT_LOG_MESSAGE_TAG_FORMAT and BT_LOG_MESSAGE_SRC_FORMAT.
 *
 * If message context must be visually separated from the rest of the message,
 * it must be reflected in context format (notice trailing S(" > ") in the
 * example above).
 *
 * S(str) adds constant string str. String can NOT contain '%' or '\0'.
 *
 * F_INIT(statements) adds initialization statement(s) that will be evaluated
 * once for each log message. All statements are evaluated in specified order.
 * Several F_INIT() fields can be used in every log message format
 * specification. Fields, like F_UINT(width, value), are allowed to use results
 * of initialization statements. If statement introduces variables (or other
 * names, like structures) they must be prefixed with "f_". Statements  must be
 * enclosed into additional "()". Example:
 *
 *   #define BT_LOG_MESSAGE_CTX_FORMAT \
 *       (F_INIT(( struct rusage f_ru; getrusage(RUSAGE_SELF, &f_ru); )), \
 *        YEAR, S("."), MONTH, S("."), DAY, S(" "), \
 *        F_UINT(5, f_ru.ru_nsignals), \
 *        S(" "))
 *
 * F_UINT(width, value) adds unsigned integer value extended with up to width
 * spaces (for alignment purposes). Value can be any expression that evaluates
 * to unsigned integer. If expression contains non-standard functions, they
 * must be declared with F_INIT(). Example:
 *
 *   #define BT_LOG_MESSAGE_CTX_FORMAT \
 *        (YEAR, S("."), MONTH, S("."), DAY, S(" "), \
 *        F_INIT(( unsigned tickcount(); )), \
 *        F_UINT(5, tickcount()), \
 *        S(" "))
 *
 * Other log message format specifications follow same rules, but have a
 * different set of supported fields.
 */
#ifndef BT_LOG_MESSAGE_CTX_FORMAT
        #define BT_LOG_MESSAGE_CTX_FORMAT \
                (MONTH, S("-"), DAY, S(BT_LOG_DEF_DELIMITER), \
                 HOUR, S(":"), MINUTE, S(":"), SECOND, S("."), MILLISECOND, S(BT_LOG_DEF_DELIMITER), \
                 PID, S(BT_LOG_DEF_DELIMITER), TID, S(BT_LOG_DEF_DELIMITER), \
                 LEVEL, S(BT_LOG_DEF_DELIMITER))
#endif
/* Example:
 */
/* Specifies log message tag format. It includes tag prefix and tag. Custom
 * information can be added as well. Supported fields:
 * TAG(prefix_delimiter, tag_delimiter), S(str), F_INIT(statements),
 * F_UINT(width, value).
 *
 * TAG(prefix_delimiter, tag_delimiter) adds following string to log message:
 *
 *   PREFIX<prefix_delimiter>TAG<tag_delimiter>
 *
 * Prefix delimiter will be used only when prefix is not empty. Tag delimiter
 * will be used only when prefixed tag is not empty. Example:
 *
 *   #define BT_LOG_TAG_FORMAT (S("["), TAG(".", ""), S("] "))
 *
 * See BT_LOG_MESSAGE_CTX_FORMAT for details.
 */
#ifndef BT_LOG_MESSAGE_TAG_FORMAT
        #define BT_LOG_MESSAGE_TAG_FORMAT \
                (TAG(".", BT_LOG_DEF_DELIMITER))
#endif
/* Specifies log message source location format. It includes function name,
 * file name and file line. Custom information can be added as well. Supported
 * fields: FUNCTION, FILENAME, FILELINE, S(str), F_INIT(statements),
 * F_UINT(width, value).
 *
 * See BT_LOG_MESSAGE_CTX_FORMAT for details.
 */
#ifndef BT_LOG_MESSAGE_SRC_FORMAT
        #define BT_LOG_MESSAGE_SRC_FORMAT \
                (FUNCTION, S("@"), FILENAME, S(":"), FILELINE, S(BT_LOG_DEF_DELIMITER))
#endif
/* Fields that can be used in log message format specifications (see above).
 * Mentioning them here explicitly, so we know that nobody else defined them
 * before us. See BT_LOG_MESSAGE_CTX_FORMAT for details.
 */
#define YEAR YEAR
#define MONTH MONTH
#define DAY DAY
#define MINUTE MINUTE
#define SECOND SECOND
#define MILLISECOND MILLISECOND
#define PID PID
#define TID TID
#define LEVEL LEVEL
#define TAG(prefix_delim, tag_delim) TAG(prefix_delim, tag_delim)
#define FUNCTION FUNCTION
#define FILENAME FILENAME
#define FILELINE FILELINE
#define S(str) S(str)
#define F_INIT(statements) F_INIT(statements)
#define F_UINT(width, value) F_UINT(width, value)
/* Number of bytes to reserve for EOL in the log line buffer (must be >0).
 * Must be larger than or equal to length of BT_LOG_EOL with terminating null.
 */
#ifndef BT_LOG_EOL_SZ
        #define BT_LOG_EOL_SZ sizeof(BT_LOG_EOL)
#endif
/* Compile instrumented version of the library to facilitate unit testing.
 */
#ifndef BT_LOG_INSTRUMENTED
        #define BT_LOG_INSTRUMENTED 0
#endif

#if defined(__linux__)
        #if !defined(__ANDROID__) && !defined(_GNU_SOURCE)
                #define _GNU_SOURCE
        #endif
#endif
#if defined(__MINGW32__)
        #ifdef __STRICT_ANSI__
                #undef __STRICT_ANSI__
        #endif
#endif
#include <assert.h>
#include <ctype.h>
#include <string.h>
#include <time.h>
#include <stdarg.h>
#include <stddef.h>
#include <stdlib.h>
#include <stdio.h>

#define BT_LOG_OUTPUT_LEVEL dummy

#include <babeltrace/logging-internal.h>
#include <babeltrace/logging.h>

#if defined(_WIN32) || defined(_WIN64)
        #include <windows.h>
#else
        #include <unistd.h>
        #include <sys/time.h>
        #if defined(__linux__)
                #include <linux/limits.h>
        #else
                #include <sys/syslimits.h>
        #endif
#endif

#if defined(__linux__)
        #include <sys/prctl.h>
        #include <sys/types.h>
        #if !defined(__ANDROID__)
                #include <sys/syscall.h>
        #endif
#endif
#if defined(__MACH__)
        #include <pthread.h>
#endif

#define INLINE _BT_LOG_INLINE
#define VAR_UNUSED(var) (void)var
#define RETVAL_UNUSED(expr) do { while(expr) break; } while(0)
#define STATIC_ASSERT(name, cond) \
        typedef char assert_##name[(cond)? 1: -1]
#define ASSERT_UNREACHABLE(why) assert(!sizeof(why))
#ifndef _countof
        #define _countof(xs) (sizeof(xs) / sizeof((xs)[0]))
#endif

#if BT_LOG_INSTRUMENTED
        #define INSTRUMENTED_CONST
#else
        #define INSTRUMENTED_CONST const
#endif

#define _PP_PASTE_2(a, b) a ## b
#define _PP_CONCAT_2(a, b) _PP_PASTE_2(a, b)

#define _PP_PASTE_3(a, b, c) a ## b ## c
#define _PP_CONCAT_3(a, b, c) _PP_PASTE_3(a, b, c)

/* Microsoft C preprocessor is a piece of shit. This moron treats __VA_ARGS__
 * as a single token and requires additional expansion to realize that it's
 * actually a list. If not for it, there would be no need in this extra
 * expansion.
 */
#define _PP_ID(x) x
#define _PP_NARGS_N(_0,_1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12,_13,_14,_15,_16,_17,_18,_19,_20,_21,_22,_23,_24,...) _24
#define _PP_NARGS(...) _PP_ID(_PP_NARGS_N(__VA_ARGS__,24,23,22,21,20,19,18,17,16,15,14,13,12,11,10,9,8,7,6,5,4,3,2,1,0))

/* There is a more efficient way to implement this, but it requires
 * working C preprocessor. Unfortunately, Microsoft Visual Studio doesn't
 * have one.
 */
#define _PP_HEAD__(x, ...) x
#define _PP_HEAD_(...) _PP_ID(_PP_HEAD__(__VA_ARGS__, ~))
#define _PP_HEAD(xs) _PP_HEAD_ xs
#define _PP_TAIL_(x, ...) (__VA_ARGS__)
#define _PP_TAIL(xs) _PP_TAIL_ xs
#define _PP_UNTUPLE_(...) __VA_ARGS__
#define _PP_UNTUPLE(xs) _PP_UNTUPLE_ xs

/* Apply function macro to each element in tuple. Output is not
 * enforced to be a tuple.
 */
#define _PP_MAP_1(f, xs) f(_PP_HEAD(xs))
#define _PP_MAP_2(f, xs) f(_PP_HEAD(xs)) _PP_MAP_1(f, _PP_TAIL(xs))
#define _PP_MAP_3(f, xs) f(_PP_HEAD(xs)) _PP_MAP_2(f, _PP_TAIL(xs))
#define _PP_MAP_4(f, xs) f(_PP_HEAD(xs)) _PP_MAP_3(f, _PP_TAIL(xs))
#define _PP_MAP_5(f, xs) f(_PP_HEAD(xs)) _PP_MAP_4(f, _PP_TAIL(xs))
#define _PP_MAP_6(f, xs) f(_PP_HEAD(xs)) _PP_MAP_5(f, _PP_TAIL(xs))
#define _PP_MAP_7(f, xs) f(_PP_HEAD(xs)) _PP_MAP_6(f, _PP_TAIL(xs))
#define _PP_MAP_8(f, xs) f(_PP_HEAD(xs)) _PP_MAP_7(f, _PP_TAIL(xs))
#define _PP_MAP_9(f, xs) f(_PP_HEAD(xs)) _PP_MAP_8(f, _PP_TAIL(xs))
#define _PP_MAP_10(f, xs) f(_PP_HEAD(xs)) _PP_MAP_9(f, _PP_TAIL(xs))
#define _PP_MAP_11(f, xs) f(_PP_HEAD(xs)) _PP_MAP_10(f, _PP_TAIL(xs))
#define _PP_MAP_12(f, xs) f(_PP_HEAD(xs)) _PP_MAP_11(f, _PP_TAIL(xs))
#define _PP_MAP_13(f, xs) f(_PP_HEAD(xs)) _PP_MAP_12(f, _PP_TAIL(xs))
#define _PP_MAP_14(f, xs) f(_PP_HEAD(xs)) _PP_MAP_13(f, _PP_TAIL(xs))
#define _PP_MAP_15(f, xs) f(_PP_HEAD(xs)) _PP_MAP_14(f, _PP_TAIL(xs))
#define _PP_MAP_16(f, xs) f(_PP_HEAD(xs)) _PP_MAP_15(f, _PP_TAIL(xs))
#define _PP_MAP_17(f, xs) f(_PP_HEAD(xs)) _PP_MAP_16(f, _PP_TAIL(xs))
#define _PP_MAP_18(f, xs) f(_PP_HEAD(xs)) _PP_MAP_17(f, _PP_TAIL(xs))
#define _PP_MAP_19(f, xs) f(_PP_HEAD(xs)) _PP_MAP_18(f, _PP_TAIL(xs))
#define _PP_MAP_20(f, xs) f(_PP_HEAD(xs)) _PP_MAP_19(f, _PP_TAIL(xs))
#define _PP_MAP_21(f, xs) f(_PP_HEAD(xs)) _PP_MAP_20(f, _PP_TAIL(xs))
#define _PP_MAP_22(f, xs) f(_PP_HEAD(xs)) _PP_MAP_21(f, _PP_TAIL(xs))
#define _PP_MAP_23(f, xs) f(_PP_HEAD(xs)) _PP_MAP_22(f, _PP_TAIL(xs))
#define _PP_MAP_24(f, xs) f(_PP_HEAD(xs)) _PP_MAP_23(f, _PP_TAIL(xs))
#define _PP_MAP(f, xs) _PP_CONCAT_2(_PP_MAP_, _PP_NARGS xs) (f, xs)

/* Apply function macro to each element in tuple in reverse order.
 * Output is not enforced to be a tuple.
 */
#define _PP_RMAP_1(f, xs) f(_PP_HEAD(xs))
#define _PP_RMAP_2(f, xs) _PP_RMAP_1(f, _PP_TAIL(xs)) f(_PP_HEAD(xs))
#define _PP_RMAP_3(f, xs) _PP_RMAP_2(f, _PP_TAIL(xs)) f(_PP_HEAD(xs))
#define _PP_RMAP_4(f, xs) _PP_RMAP_3(f, _PP_TAIL(xs)) f(_PP_HEAD(xs))
#define _PP_RMAP_5(f, xs) _PP_RMAP_4(f, _PP_TAIL(xs)) f(_PP_HEAD(xs))
#define _PP_RMAP_6(f, xs) _PP_RMAP_5(f, _PP_TAIL(xs)) f(_PP_HEAD(xs))
#define _PP_RMAP_7(f, xs) _PP_RMAP_6(f, _PP_TAIL(xs)) f(_PP_HEAD(xs))
#define _PP_RMAP_8(f, xs) _PP_RMAP_7(f, _PP_TAIL(xs)) f(_PP_HEAD(xs))
#define _PP_RMAP_9(f, xs) _PP_RMAP_8(f, _PP_TAIL(xs)) f(_PP_HEAD(xs))
#define _PP_RMAP_10(f, xs) _PP_RMAP_9(f, _PP_TAIL(xs)) f(_PP_HEAD(xs))
#define _PP_RMAP_11(f, xs) _PP_RMAP_10(f, _PP_TAIL(xs)) f(_PP_HEAD(xs))
#define _PP_RMAP_12(f, xs) _PP_RMAP_11(f, _PP_TAIL(xs)) f(_PP_HEAD(xs))
#define _PP_RMAP_13(f, xs) _PP_RMAP_12(f, _PP_TAIL(xs)) f(_PP_HEAD(xs))
#define _PP_RMAP_14(f, xs) _PP_RMAP_13(f, _PP_TAIL(xs)) f(_PP_HEAD(xs))
#define _PP_RMAP_15(f, xs) _PP_RMAP_14(f, _PP_TAIL(xs)) f(_PP_HEAD(xs))
#define _PP_RMAP_16(f, xs) _PP_RMAP_15(f, _PP_TAIL(xs)) f(_PP_HEAD(xs))
#define _PP_RMAP_17(f, xs) _PP_RMAP_16(f, _PP_TAIL(xs)) f(_PP_HEAD(xs))
#define _PP_RMAP_18(f, xs) _PP_RMAP_17(f, _PP_TAIL(xs)) f(_PP_HEAD(xs))
#define _PP_RMAP_19(f, xs) _PP_RMAP_18(f, _PP_TAIL(xs)) f(_PP_HEAD(xs))
#define _PP_RMAP_20(f, xs) _PP_RMAP_19(f, _PP_TAIL(xs)) f(_PP_HEAD(xs))
#define _PP_RMAP_21(f, xs) _PP_RMAP_20(f, _PP_TAIL(xs)) f(_PP_HEAD(xs))
#define _PP_RMAP_22(f, xs) _PP_RMAP_21(f, _PP_TAIL(xs)) f(_PP_HEAD(xs))
#define _PP_RMAP_23(f, xs) _PP_RMAP_22(f, _PP_TAIL(xs)) f(_PP_HEAD(xs))
#define _PP_RMAP_24(f, xs) _PP_RMAP_23(f, _PP_TAIL(xs)) f(_PP_HEAD(xs))
#define _PP_RMAP(f, xs) _PP_CONCAT_2(_PP_RMAP_, _PP_NARGS xs) (f, xs)

/* Used to implement _BT_LOG_MESSAGE_FORMAT_CONTAINS() macro. All possible
 * fields must be mentioned here. Not counting F_INIT() here because it's
 * somewhat special and is handled spearatly (at least for now).
 */
#define _BT_LOG_MESSAGE_FORMAT_MASK__             (0<<0)
#define _BT_LOG_MESSAGE_FORMAT_MASK__YEAR         (1<<1)
#define _BT_LOG_MESSAGE_FORMAT_MASK__MONTH        (1<<2)
#define _BT_LOG_MESSAGE_FORMAT_MASK__DAY          (1<<3)
#define _BT_LOG_MESSAGE_FORMAT_MASK__HOUR         (1<<4)
#define _BT_LOG_MESSAGE_FORMAT_MASK__MINUTE       (1<<5)
#define _BT_LOG_MESSAGE_FORMAT_MASK__SECOND       (1<<6)
#define _BT_LOG_MESSAGE_FORMAT_MASK__MILLISECOND  (1<<7)
#define _BT_LOG_MESSAGE_FORMAT_MASK__PID          (1<<8)
#define _BT_LOG_MESSAGE_FORMAT_MASK__TID          (1<<9)
#define _BT_LOG_MESSAGE_FORMAT_MASK__LEVEL        (1<<10)
#define _BT_LOG_MESSAGE_FORMAT_MASK__TAG(ps, ts)  (1<<11)
#define _BT_LOG_MESSAGE_FORMAT_MASK__FUNCTION     (1<<12)
#define _BT_LOG_MESSAGE_FORMAT_MASK__FILENAME     (1<<13)
#define _BT_LOG_MESSAGE_FORMAT_MASK__FILELINE     (1<<14)
#define _BT_LOG_MESSAGE_FORMAT_MASK__S(s)         (1<<15)
#define _BT_LOG_MESSAGE_FORMAT_MASK__F_INIT(expr) (0<<16)
#define _BT_LOG_MESSAGE_FORMAT_MASK__F_UINT(w, v) (1<<17)
#define _BT_LOG_MESSAGE_FORMAT_MASK(field) \
        _PP_CONCAT_3(_BT_LOG_MESSAGE_FORMAT_MASK_, _, field)

/* Logical "or" of masks of fields used in specified format specification.
 */
#define _BT_LOG_MESSAGE_FORMAT_FIELDS(format) \
        (0 _PP_MAP(| _BT_LOG_MESSAGE_FORMAT_MASK, format))

/* Expands to expressions that evaluates to true if field is used in
 * specified format specification. Example:
 *
 *   #if _BT_LOG_MESSAGE_FORMAT_CONTAINS(F_UINT, BT_LOG_MESSAGE_CTX_FORMAT)
 *       ...
 *   #endif
 */
#define _BT_LOG_MESSAGE_FORMAT_CONTAINS(field, format) \
        (_BT_LOG_MESSAGE_FORMAT_MASK(field) & _BT_LOG_MESSAGE_FORMAT_FIELDS(format))

/* Same, but checks all supported format specifications.
 */
#define _BT_LOG_MESSAGE_FORMAT_FIELD_USED(field) \
        (_BT_LOG_MESSAGE_FORMAT_CONTAINS(field, BT_LOG_MESSAGE_CTX_FORMAT) || \
         _BT_LOG_MESSAGE_FORMAT_CONTAINS(field, BT_LOG_MESSAGE_TAG_FORMAT) || \
         _BT_LOG_MESSAGE_FORMAT_CONTAINS(field, BT_LOG_MESSAGE_SRC_FORMAT))

#define _BT_LOG_MESSAGE_FORMAT_DATETIME_USED \
        (_BT_LOG_MESSAGE_FORMAT_CONTAINS(YEAR, BT_LOG_MESSAGE_CTX_FORMAT) || \
         _BT_LOG_MESSAGE_FORMAT_CONTAINS(MONTH, BT_LOG_MESSAGE_CTX_FORMAT) || \
         _BT_LOG_MESSAGE_FORMAT_CONTAINS(DAY, BT_LOG_MESSAGE_CTX_FORMAT) || \
         _BT_LOG_MESSAGE_FORMAT_CONTAINS(HOUR, BT_LOG_MESSAGE_CTX_FORMAT) || \
         _BT_LOG_MESSAGE_FORMAT_CONTAINS(MINUTE, BT_LOG_MESSAGE_CTX_FORMAT) || \
         _BT_LOG_MESSAGE_FORMAT_CONTAINS(SECOND, BT_LOG_MESSAGE_CTX_FORMAT) || \
         _BT_LOG_MESSAGE_FORMAT_CONTAINS(MILLISECOND, BT_LOG_MESSAGE_CTX_FORMAT))

#if defined(_MSC_VER) && !defined(__INTEL_COMPILER)
        #pragma warning(disable:4204) /* nonstandard extension used: non-constant aggregate initializer */
        #define memccpy _memccpy
#endif

#if (defined(_MSC_VER) && !defined(__INTEL_COMPILER)) || defined(__MINGW64__)
        #define vsnprintf(s, sz, fmt, va) fake_vsnprintf(s, sz, fmt, va)
        static int fake_vsnprintf(char *s, size_t sz, const char *fmt, va_list ap)
        {
                const int n = vsnprintf_s(s, sz, _TRUNCATE, fmt, ap);
                return 0 < n? n: (int)sz + 1; /* no need in _vscprintf() for now */
        }
        #if BT_LOG_OPTIMIZE_SIZE
        #define snprintf(s, sz, ...) fake_snprintf(s, sz, __VA_ARGS__)
        static int fake_snprintf(char *s, size_t sz, const char *fmt, ...)
        {
                va_list va;
                va_start(va, fmt);
                const int n = fake_vsnprintf(s, sz, fmt, va);
                va_end(va);
                return n;
        }
        #endif
#endif

typedef void (*time_cb)(struct tm *const tm, unsigned *const usec);
typedef void (*pid_cb)(int *const pid, int *const tid);
typedef void (*buffer_cb)(bt_log_message *msg, char *buf);

typedef struct src_location
{
        const char *const func;
        const char *const file;
        const unsigned line;
}
src_location;

typedef struct mem_block
{
        const void *const d;
        const unsigned d_sz;
}
mem_block;

static void time_callback(struct tm *const tm, unsigned *const usec);
static void pid_callback(int *const pid, int *const tid);
static void buffer_callback(bt_log_message *msg, char *buf);

STATIC_ASSERT(eol_fits_eol_sz, sizeof(BT_LOG_EOL) <= BT_LOG_EOL_SZ);
STATIC_ASSERT(eol_sz_greater_than_zero, 0 < BT_LOG_EOL_SZ);
STATIC_ASSERT(eol_sz_less_than_buf_sz, BT_LOG_EOL_SZ < BT_LOG_BUF_SZ);
#if !defined(_WIN32) && !defined(_WIN64)
        STATIC_ASSERT(buf_sz_less_than_pipe_buf, BT_LOG_BUF_SZ <= PIPE_BUF);
#endif
static const char c_hex[] = "0123456789abcdef";

static INSTRUMENTED_CONST unsigned g_buf_sz = BT_LOG_BUF_SZ - BT_LOG_EOL_SZ;
static INSTRUMENTED_CONST time_cb g_time_cb = time_callback;
static INSTRUMENTED_CONST pid_cb g_pid_cb = pid_callback;
static INSTRUMENTED_CONST buffer_cb g_buffer_cb = buffer_callback;

#if BT_LOG_USE_ANDROID_LOG
        #include <android/log.h>

        static INLINE int android_lvl(const int lvl)
        {
                switch (lvl)
                {
                case BT_LOG_VERBOSE:
                        return ANDROID_LOG_VERBOSE;
                case BT_LOG_DEBUG:
                        return ANDROID_LOG_DEBUG;
                case BT_LOG_INFO:
                        return ANDROID_LOG_INFO;
                case BT_LOG_WARN:
                        return ANDROID_LOG_WARN;
                case BT_LOG_ERROR:
                        return ANDROID_LOG_ERROR;
                case BT_LOG_FATAL:
                        return ANDROID_LOG_FATAL;
                default:
                        ASSERT_UNREACHABLE("Bad log level");
                        return ANDROID_LOG_UNKNOWN;
                }
        }

        static void out_android_callback(const bt_log_message *const msg, void *arg)
        {
                VAR_UNUSED(arg);
                *msg->p = 0;
                const char *tag = msg->p;
                if (msg->tag_e != msg->tag_b)
                {
                        tag = msg->tag_b;
                        *msg->tag_e = 0;
                }
                __android_log_print(android_lvl(msg->lvl), tag, "%s", msg->msg_b);
        }

        enum { OUT_ANDROID_MASK = BT_LOG_PUT_STD & ~BT_LOG_PUT_CTX };
        #define OUT_ANDROID OUT_ANDROID_MASK, 0, out_android_callback
#endif

#if BT_LOG_USE_NSLOG
        #include <CoreFoundation/CoreFoundation.h>
        CF_EXPORT void CFLog(int32_t level, CFStringRef format, ...);

        static INLINE int apple_lvl(const int lvl)
        {
                switch (lvl)
                {
                case BT_LOG_VERBOSE:
                        return 7; /* ASL_LEVEL_DEBUG / kCFLogLevelDebug */;
                case BT_LOG_DEBUG:
                        return 7; /* ASL_LEVEL_DEBUG / kCFLogLevelDebug */;
                case BT_LOG_INFO:
                        return 6; /* ASL_LEVEL_INFO / kCFLogLevelInfo */;
                case BT_LOG_WARN:
                        return 4; /* ASL_LEVEL_WARNING / kCFLogLevelWarning */;
                case BT_LOG_ERROR:
                        return 3; /* ASL_LEVEL_ERR / kCFLogLevelError */;
                case BT_LOG_FATAL:
                        return 0; /* ASL_LEVEL_EMERG / kCFLogLevelEmergency */;
                default:
                        ASSERT_UNREACHABLE("Bad log level");
                        return 0; /* ASL_LEVEL_EMERG / kCFLogLevelEmergency */;
                }
        }

        static void out_nslog_callback(const bt_log_message *const msg, void *arg)
        {
                VAR_UNUSED(arg);
                *msg->p = 0;
                CFLog(apple_lvl(msg->lvl), CFSTR("%s"), msg->tag_b);
        }

        enum { OUT_NSLOG_MASK = BT_LOG_PUT_STD & ~BT_LOG_PUT_CTX };
        #define OUT_NSLOG OUT_NSLOG_MASK, 0, out_nslog_callback
#endif

#if BT_LOG_USE_DEBUGSTRING
        #include <windows.h>

        static void out_debugstring_callback(const bt_log_message *const msg, void *arg)
        {
                VAR_UNUSED(arg);
                msg->p[0] = '\n';
                msg->p[1] = '\0';
                OutputDebugStringA(msg->buf);
        }

        enum { OUT_DEBUGSTRING_MASK = BT_LOG_PUT_STD };
        #define OUT_DEBUGSTRING OUT_DEBUGSTRING_MASK, 0, out_debugstring_callback
#endif

BT_HIDDEN
void bt_log_out_stderr_callback(const bt_log_message *const msg, void *arg)
{
        VAR_UNUSED(arg);
        const size_t eol_len = sizeof(BT_LOG_EOL) - 1;
        memcpy(msg->p, BT_LOG_EOL, eol_len);
#if defined(_WIN32) || defined(_WIN64)
        /* WriteFile() is atomic for local files opened with FILE_APPEND_DATA and
           without FILE_WRITE_DATA */
        WriteFile(GetStdHandle(STD_ERROR_HANDLE), msg->buf,
                          (DWORD)(msg->p - msg->buf + eol_len), 0, 0);
#else
        /* write() is atomic for buffers less than or equal to PIPE_BUF. */
        RETVAL_UNUSED(write(STDERR_FILENO, msg->buf,
                                                (size_t)(msg->p - msg->buf) + eol_len));
#endif
}

static const bt_log_output out_stderr = {BT_LOG_OUT_STDERR};

#if !BT_LOG_EXTERN_TAG_PREFIX
        BT_LOG_DEFINE_TAG_PREFIX = 0;
#endif

#if !BT_LOG_EXTERN_GLOBAL_FORMAT
        BT_LOG_DEFINE_GLOBAL_FORMAT = {BT_LOG_MEM_WIDTH};
#endif

#if !BT_LOG_EXTERN_GLOBAL_OUTPUT
        #if BT_LOG_USE_ANDROID_LOG
                BT_LOG_DEFINE_GLOBAL_OUTPUT = {OUT_ANDROID};
        #elif BT_LOG_USE_NSLOG
                BT_LOG_DEFINE_GLOBAL_OUTPUT = {OUT_NSLOG};
        #elif BT_LOG_USE_DEBUGSTRING
                BT_LOG_DEFINE_GLOBAL_OUTPUT = {OUT_DEBUGSTRING};
        #else
                BT_LOG_DEFINE_GLOBAL_OUTPUT = {BT_LOG_OUT_STDERR};
        #endif
#endif

#if !BT_LOG_EXTERN_GLOBAL_OUTPUT_LEVEL
        BT_LOG_DEFINE_GLOBAL_OUTPUT_LEVEL = 0;
#endif

const bt_log_spec _bt_log_stderr_spec =
{
        BT_LOG_GLOBAL_FORMAT,
        &out_stderr,
};

static const bt_log_spec global_spec =
{
        BT_LOG_GLOBAL_FORMAT,
        BT_LOG_GLOBAL_OUTPUT,
};

#if _BT_LOG_MESSAGE_FORMAT_CONTAINS(LEVEL, BT_LOG_MESSAGE_CTX_FORMAT)
static char lvl_char(const int lvl)
{
        switch (lvl)
        {
        case BT_LOG_VERBOSE:
                return 'V';
        case BT_LOG_DEBUG:
                return 'D';
        case BT_LOG_INFO:
                return 'I';
        case BT_LOG_WARN:
                return 'W';
        case BT_LOG_ERROR:
                return 'E';
        case BT_LOG_FATAL:
                return 'F';
        default:
                ASSERT_UNREACHABLE("Bad log level");
                return '?';
        }
}
#endif

#define GCCVER_LESS(MAJOR, MINOR, PATCH) \
        (__GNUC__ < MAJOR || \
                (__GNUC__ == MAJOR && (__GNUC_MINOR__ < MINOR || \
                        (__GNUC_MINOR__ == MINOR && __GNUC_PATCHLEVEL__ < PATCH))))

#if !defined(__clang__) && defined(__GNUC__) && GCCVER_LESS(4,7,0)
        #define __atomic_load_n(vp, model) __sync_fetch_and_add(vp, 0)
        #define __atomic_fetch_add(vp, n, model) __sync_fetch_and_add(vp, n)
        #define __atomic_sub_fetch(vp, n, model) __sync_sub_and_fetch(vp, n)
        #define __atomic_or_fetch(vp, n, model) __sync_or_and_fetch(vp, n)
        #define __atomic_and_fetch(vp, n, model) __sync_and_and_fetch(vp, n)
        /* Note: will not store old value of *vp in *ep (non-standard behaviour) */
        #define __atomic_compare_exchange_n(vp, ep, d, weak, smodel, fmodel) \
                __sync_bool_compare_and_swap(vp, *(ep), d)
#endif

#if !BT_LOG_OPTIMIZE_SIZE && !defined(_WIN32) && !defined(_WIN64)
#define TCACHE
#define TCACHE_STALE (0x40000000)
#define TCACHE_FLUID (0x40000000 | 0x80000000)
static unsigned g_tcache_mode = TCACHE_STALE;
static struct timeval g_tcache_tv = {0, 0};
static struct tm g_tcache_tm = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};

static INLINE int tcache_get(const struct timeval *const tv, struct tm *const tm)
{
        unsigned mode;
        mode = __atomic_load_n(&g_tcache_mode, __ATOMIC_RELAXED);
        if (0 == (mode & TCACHE_FLUID))
        {
                mode = __atomic_fetch_add(&g_tcache_mode, 1, __ATOMIC_ACQUIRE);
                if (0 == (mode & TCACHE_FLUID))
                {
                        if (g_tcache_tv.tv_sec == tv->tv_sec)
                        {
                                *tm = g_tcache_tm;
                                __atomic_sub_fetch(&g_tcache_mode, 1, __ATOMIC_RELEASE);
                                return !0;
                        }
                        __atomic_or_fetch(&g_tcache_mode, TCACHE_STALE, __ATOMIC_RELAXED);
                }
                __atomic_sub_fetch(&g_tcache_mode, 1, __ATOMIC_RELEASE);
        }
        return 0;
}

static INLINE void tcache_set(const struct timeval *const tv, struct tm *const tm)
{
        unsigned stale = TCACHE_STALE;
        if (__atomic_compare_exchange_n(&g_tcache_mode, &stale, TCACHE_FLUID,
                                                                        0, __ATOMIC_ACQUIRE, __ATOMIC_RELAXED))
        {
                g_tcache_tv = *tv;
                g_tcache_tm = *tm;
                __atomic_and_fetch(&g_tcache_mode, ~TCACHE_FLUID, __ATOMIC_RELEASE);
        }
}
#endif

static void time_callback(struct tm *const tm, unsigned *const msec)
{
#if !_BT_LOG_MESSAGE_FORMAT_DATETIME_USED
        VAR_UNUSED(tm);
        VAR_UNUSED(msec);
#else
        #if defined(_WIN32) || defined(_WIN64)
        SYSTEMTIME st;
        GetLocalTime(&st);
        tm->tm_year = st.wYear;
        tm->tm_mon = st.wMonth;
        tm->tm_mday = st.wDay;
        tm->tm_wday = st.wDayOfWeek;
        tm->tm_hour = st.wHour;
        tm->tm_min = st.wMinute;
        tm->tm_sec = st.wSecond;
        *msec = st.wMilliseconds;
        #else
        struct timeval tv;
        gettimeofday(&tv, 0);
                #ifndef TCACHE
                localtime_r(&tv.tv_sec, tm);
                #else
                if (!tcache_get(&tv, tm))
                {
                        localtime_r(&tv.tv_sec, tm);
                        tcache_set(&tv, tm);
                }
                #endif
        *msec = (unsigned)tv.tv_usec / 1000;
        #endif
#endif
}

static void pid_callback(int *const pid, int *const tid)
{
#if !_BT_LOG_MESSAGE_FORMAT_CONTAINS(PID, BT_LOG_MESSAGE_CTX_FORMAT)
        VAR_UNUSED(pid);
#else
        #if defined(_WIN32) || defined(_WIN64)
        *pid = GetCurrentProcessId();
        #else
        *pid = getpid();
        #endif
#endif

#if !_BT_LOG_MESSAGE_FORMAT_CONTAINS(TID, BT_LOG_MESSAGE_CTX_FORMAT)
        VAR_UNUSED(tid);
#else
        #if defined(_WIN32) || defined(_WIN64)
        *tid = GetCurrentThreadId();
        #elif defined(__CYGWIN__)
        pthread_t thr = pthread_self();
        *tid = (int)pthread_getsequence_np(&thr);
        #elif defined(__ANDROID__)
        *tid = gettid();
        #elif defined(__linux__)
        *tid = syscall(SYS_gettid);
        #elif defined(__MACH__)
        *tid = (int)pthread_mach_thread_np(pthread_self());
        #else
                #define Platform not supported
        #endif
#endif
}

static void buffer_callback(bt_log_message *msg, char *buf)
{
        msg->e = (msg->p = msg->buf = buf) + g_buf_sz;
}

#if _BT_LOG_MESSAGE_FORMAT_CONTAINS(FUNCTION, BT_LOG_MESSAGE_SRC_FORMAT)
static const char *funcname(const char *func)
{
        return func? func: "";
}
#endif

#if _BT_LOG_MESSAGE_FORMAT_CONTAINS(FILENAME, BT_LOG_MESSAGE_SRC_FORMAT)
static const char *filename(const char *file)
{
        const char *f = file;
        for (const char *p = file; 0 != *p; ++p)
        {
                if ('/' == *p || '\\' == *p)
                {
                        f = p + 1;
                }
        }
        return f;
}
#endif

static INLINE size_t nprintf_size(bt_log_message *const msg)
{
        // *nprintf() always puts 0 in the end when input buffer is not empty. This
        // 0 is not desired because its presence sets (ctx->p) to (ctx->e - 1) which
        // leaves space for one more character. Some put_xxx() functions don't use
        // *nprintf() and could use that last character. In that case log line will
        // have multiple (two) half-written parts which is confusing. To workaround
        // that we allow *nprintf() to write its 0 in the eol area (which is always
        // not empty).
        return (size_t)(msg->e - msg->p + 1);
}

static INLINE void put_nprintf(bt_log_message *const msg, const int n)
{
        if (0 < n)
        {
                msg->p = n < msg->e - msg->p? msg->p + n: msg->e;
        }
}

static INLINE char *put_padding_r(const unsigned w, const char wc,
                                                                  char *p, char *e)
{
        for (char *const b = e - w; b < p; *--p = wc) {}
        return p;
}

static char *put_integer_r(unsigned v, const int sign,
                                                   const unsigned w, const char wc, char *const e)
{
        static const char _signs[] = {'-', '0', '+'};
        static const char *const signs = _signs + 1;
        char *p = e;
        do { *--p = '0' + v % 10; } while (0 != (v /= 10));
        if (0 == sign) return put_padding_r(w, wc, p, e);
        if ('0' != wc)
        {
                *--p = signs[sign];
                return put_padding_r(w, wc, p, e);
        }
        p = put_padding_r(w, wc, p, e + 1);
        *--p = signs[sign];
        return p;
}

static INLINE char *put_uint_r(const unsigned v, const unsigned w, const char wc,
                                                           char *const e)
{
        return put_integer_r(v, 0, w, wc, e);
}

static INLINE char *put_int_r(const int v, const unsigned w, const char wc,
                                                          char *const e)
{
        return 0 <= v? put_integer_r((unsigned)v, 0, w, wc, e)
                                 : put_integer_r((unsigned)-v, -1, w, wc, e);
}

static INLINE char *put_stringn(const char *const s_p, const char *const s_e,
                                                                char *const p, char *const e)
{
        const ptrdiff_t m = e - p;
        ptrdiff_t n = s_e - s_p;
        if (n > m)
        {
                n = m;
        }
        memcpy(p, s_p, n);
        return p + n;
}

static INLINE char *put_string(const char *s, char *p, char *const e)
{
        const ptrdiff_t n = e - p;
        char *const c = (char *)memccpy(p, s, '\0', n);
        return 0 != c? c - 1: e;
}

static INLINE char *put_uint(unsigned v, const unsigned w, const char wc,
                                                         char *const p, char *const e)
{
        char buf[16];
        char *const se = buf + _countof(buf);
        char *sp = put_uint_r(v, w, wc, se);
        return put_stringn(sp, se, p, e);
}

#define PUT_CSTR_R(p, STR) \
        do { \
                for (unsigned i = sizeof(STR) - 1; 0 < i--;) { \
                        *--(p) = (STR)[i]; \
                } \
        } _BT_LOG_ONCE

#define PUT_CSTR_CHECKED(p, e, STR) \
        do { \
                for (unsigned i = 0; (e) > (p) && (sizeof(STR) - 1) > i; ++i) { \
                        *(p)++ = (STR)[i]; \
                } \
        } _BT_LOG_ONCE

/* F_INIT field support.
 */
#define _BT_LOG_MESSAGE_FORMAT_INIT__
#define _BT_LOG_MESSAGE_FORMAT_INIT__YEAR
#define _BT_LOG_MESSAGE_FORMAT_INIT__MONTH
#define _BT_LOG_MESSAGE_FORMAT_INIT__DAY
#define _BT_LOG_MESSAGE_FORMAT_INIT__HOUR
#define _BT_LOG_MESSAGE_FORMAT_INIT__MINUTE
#define _BT_LOG_MESSAGE_FORMAT_INIT__SECOND
#define _BT_LOG_MESSAGE_FORMAT_INIT__MILLISECOND
#define _BT_LOG_MESSAGE_FORMAT_INIT__PID
#define _BT_LOG_MESSAGE_FORMAT_INIT__TID
#define _BT_LOG_MESSAGE_FORMAT_INIT__LEVEL
#define _BT_LOG_MESSAGE_FORMAT_INIT__TAG(ps, ts)
#define _BT_LOG_MESSAGE_FORMAT_INIT__FUNCTION
#define _BT_LOG_MESSAGE_FORMAT_INIT__FILENAME
#define _BT_LOG_MESSAGE_FORMAT_INIT__FILELINE
#define _BT_LOG_MESSAGE_FORMAT_INIT__S(s)
#define _BT_LOG_MESSAGE_FORMAT_INIT__F_INIT(expr) _PP_UNTUPLE(expr);
#define _BT_LOG_MESSAGE_FORMAT_INIT__F_UINT(w, v)
#define _BT_LOG_MESSAGE_FORMAT_INIT(field) \
        _PP_CONCAT_3(_BT_LOG_MESSAGE_FORMAT_INIT_, _, field)

/* Implements generation of printf-like format string for log message
 * format specification.
 */
#define _BT_LOG_MESSAGE_FORMAT_PRINTF_FMT__             ""
#define _BT_LOG_MESSAGE_FORMAT_PRINTF_FMT__YEAR         "%04u"
#define _BT_LOG_MESSAGE_FORMAT_PRINTF_FMT__MONTH        "%02u"
#define _BT_LOG_MESSAGE_FORMAT_PRINTF_FMT__DAY          "%02u"
#define _BT_LOG_MESSAGE_FORMAT_PRINTF_FMT__HOUR         "%02u"
#define _BT_LOG_MESSAGE_FORMAT_PRINTF_FMT__MINUTE       "%02u"
#define _BT_LOG_MESSAGE_FORMAT_PRINTF_FMT__SECOND       "%02u"
#define _BT_LOG_MESSAGE_FORMAT_PRINTF_FMT__MILLISECOND  "%03u"
#define _BT_LOG_MESSAGE_FORMAT_PRINTF_FMT__PID          "%5i"
#define _BT_LOG_MESSAGE_FORMAT_PRINTF_FMT__TID          "%5i"
#define _BT_LOG_MESSAGE_FORMAT_PRINTF_FMT__LEVEL        "%c"
#define _BT_LOG_MESSAGE_FORMAT_PRINTF_FMT__TAG          UNDEFINED
#define _BT_LOG_MESSAGE_FORMAT_PRINTF_FMT__FUNCTION     "%s"
#define _BT_LOG_MESSAGE_FORMAT_PRINTF_FMT__FILENAME     "%s"
#define _BT_LOG_MESSAGE_FORMAT_PRINTF_FMT__FILELINE     "%u"
#define _BT_LOG_MESSAGE_FORMAT_PRINTF_FMT__S(s)         s
#define _BT_LOG_MESSAGE_FORMAT_PRINTF_FMT__F_INIT(expr) ""
#define _BT_LOG_MESSAGE_FORMAT_PRINTF_FMT__F_UINT(w, v) "%" #w "u"
#define _BT_LOG_MESSAGE_FORMAT_PRINTF_FMT(field) \
        _PP_CONCAT_3(_BT_LOG_MESSAGE_FORMAT_PRINTF_FMT_, _, field)

/* Implements generation of printf-like format parameters for log message
 * format specification.
 */
#define _BT_LOG_MESSAGE_FORMAT_PRINTF_VAL__
#define _BT_LOG_MESSAGE_FORMAT_PRINTF_VAL__YEAR         ,(unsigned)(tm.tm_year + 1900)
#define _BT_LOG_MESSAGE_FORMAT_PRINTF_VAL__MONTH        ,(unsigned)(tm.tm_mon + 1)
#define _BT_LOG_MESSAGE_FORMAT_PRINTF_VAL__DAY          ,(unsigned)tm.tm_mday
#define _BT_LOG_MESSAGE_FORMAT_PRINTF_VAL__HOUR         ,(unsigned)tm.tm_hour
#define _BT_LOG_MESSAGE_FORMAT_PRINTF_VAL__MINUTE       ,(unsigned)tm.tm_min
#define _BT_LOG_MESSAGE_FORMAT_PRINTF_VAL__SECOND       ,(unsigned)tm.tm_sec
#define _BT_LOG_MESSAGE_FORMAT_PRINTF_VAL__MILLISECOND  ,(unsigned)msec
#define _BT_LOG_MESSAGE_FORMAT_PRINTF_VAL__PID          ,pid
#define _BT_LOG_MESSAGE_FORMAT_PRINTF_VAL__TID          ,tid
#define _BT_LOG_MESSAGE_FORMAT_PRINTF_VAL__LEVEL        ,(char)lvl_char(msg->lvl)
#define _BT_LOG_MESSAGE_FORMAT_PRINTF_VAL__TAG          UNDEFINED
#define _BT_LOG_MESSAGE_FORMAT_PRINTF_VAL__FUNCTION     ,funcname(src->func)
#define _BT_LOG_MESSAGE_FORMAT_PRINTF_VAL__FILENAME     ,filename(src->file)
#define _BT_LOG_MESSAGE_FORMAT_PRINTF_VAL__FILELINE     ,src->line
#define _BT_LOG_MESSAGE_FORMAT_PRINTF_VAL__S(s)
#define _BT_LOG_MESSAGE_FORMAT_PRINTF_VAL__F_INIT(expr)
#define _BT_LOG_MESSAGE_FORMAT_PRINTF_VAL__F_UINT(w, v) ,v
#define _BT_LOG_MESSAGE_FORMAT_PRINTF_VAL(field) \
        _PP_CONCAT_3(_BT_LOG_MESSAGE_FORMAT_PRINTF_VAL_, _, field)

/* Implements generation of put_xxx_t statements for log message specification.
 */
#define _BT_LOG_MESSAGE_FORMAT_PUT_R__
#define _BT_LOG_MESSAGE_FORMAT_PUT_R__YEAR         p = put_uint_r(tm.tm_year + 1900, 4, '0', p);
#define _BT_LOG_MESSAGE_FORMAT_PUT_R__MONTH        p = put_uint_r((unsigned)tm.tm_mon + 1, 2, '0', p);
#define _BT_LOG_MESSAGE_FORMAT_PUT_R__DAY          p = put_uint_r((unsigned)tm.tm_mday, 2, '0', p);
#define _BT_LOG_MESSAGE_FORMAT_PUT_R__HOUR         p = put_uint_r((unsigned)tm.tm_hour, 2, '0', p);
#define _BT_LOG_MESSAGE_FORMAT_PUT_R__MINUTE       p = put_uint_r((unsigned)tm.tm_min, 2, '0', p);
#define _BT_LOG_MESSAGE_FORMAT_PUT_R__SECOND       p = put_uint_r((unsigned)tm.tm_sec, 2, '0', p);
#define _BT_LOG_MESSAGE_FORMAT_PUT_R__MILLISECOND  p = put_uint_r(msec, 3, '0', p);
#define _BT_LOG_MESSAGE_FORMAT_PUT_R__PID          p = put_int_r(pid, 5, ' ', p);
#define _BT_LOG_MESSAGE_FORMAT_PUT_R__TID          p = put_int_r(tid, 5, ' ', p);
#define _BT_LOG_MESSAGE_FORMAT_PUT_R__LEVEL        *--p = lvl_char(msg->lvl);
#define _BT_LOG_MESSAGE_FORMAT_PUT_R__TAG          UNDEFINED
#define _BT_LOG_MESSAGE_FORMAT_PUT_R__FUNCTION     UNDEFINED
#define _BT_LOG_MESSAGE_FORMAT_PUT_R__FILENAME     UNDEFINED
#define _BT_LOG_MESSAGE_FORMAT_PUT_R__FILELINE     UNDEFINED
#define _BT_LOG_MESSAGE_FORMAT_PUT_R__S(s)         PUT_CSTR_R(p, s);
#define _BT_LOG_MESSAGE_FORMAT_PUT_R__F_INIT(expr)
#define _BT_LOG_MESSAGE_FORMAT_PUT_R__F_UINT(w, v) p = put_uint_r(v, w, ' ', p);
#define _BT_LOG_MESSAGE_FORMAT_PUT_R(field) \
        _PP_CONCAT_3(_BT_LOG_MESSAGE_FORMAT_PUT_R_, _, field)

static void put_ctx(bt_log_message *const msg)
{
        _PP_MAP(_BT_LOG_MESSAGE_FORMAT_INIT, BT_LOG_MESSAGE_CTX_FORMAT)
#if !_BT_LOG_MESSAGE_FORMAT_FIELDS(BT_LOG_MESSAGE_CTX_FORMAT)
        VAR_UNUSED(msg);
#else
        #if _BT_LOG_MESSAGE_FORMAT_DATETIME_USED
        struct tm tm;
        unsigned msec;
        g_time_cb(&tm, &msec);
        #endif
        #if _BT_LOG_MESSAGE_FORMAT_CONTAINS(PID, BT_LOG_MESSAGE_CTX_FORMAT) || \
                _BT_LOG_MESSAGE_FORMAT_CONTAINS(TID, BT_LOG_MESSAGE_CTX_FORMAT)
        int pid, tid;
        g_pid_cb(&pid, &tid);
        #endif

        #if BT_LOG_OPTIMIZE_SIZE
        int n;
        n = snprintf(msg->p, nprintf_size(msg),
                                 _PP_MAP(_BT_LOG_MESSAGE_FORMAT_PRINTF_FMT, BT_LOG_MESSAGE_CTX_FORMAT)
                 _PP_MAP(_BT_LOG_MESSAGE_FORMAT_PRINTF_VAL, BT_LOG_MESSAGE_CTX_FORMAT));
        put_nprintf(msg, n);
        #else
        char buf[64];
        char *const e = buf + sizeof(buf);
        char *p = e;
        _PP_RMAP(_BT_LOG_MESSAGE_FORMAT_PUT_R, BT_LOG_MESSAGE_CTX_FORMAT)
        msg->p = put_stringn(p, e, msg->p, msg->e);
        #endif
#endif
}

#define PUT_TAG(msg, tag, prefix_delim, tag_delim) \
        do { \
                const char *ch; \
                msg->tag_b = msg->p; \
                if (0 != (ch = _bt_log_tag_prefix)) { \
                        for (;msg->e != msg->p && 0 != (*msg->p = *ch); ++msg->p, ++ch) {} \
                } \
                if (0 != (ch = tag) && 0 != tag[0]) { \
                        if (msg->tag_b != msg->p) { \
                                PUT_CSTR_CHECKED(msg->p, msg->e, prefix_delim); \
                        } \
                        for (;msg->e != msg->p && 0 != (*msg->p = *ch); ++msg->p, ++ch) {} \
                } \
                msg->tag_e = msg->p; \
                if (msg->tag_b != msg->p) { \
                        PUT_CSTR_CHECKED(msg->p, msg->e, tag_delim); \
                } \
        } _BT_LOG_ONCE

/* Implements simple put statements for log message specification.
 */
#define _BT_LOG_MESSAGE_FORMAT_PUT__
#define _BT_LOG_MESSAGE_FORMAT_PUT__YEAR         UNDEFINED
#define _BT_LOG_MESSAGE_FORMAT_PUT__MONTH        UNDEFINED
#define _BT_LOG_MESSAGE_FORMAT_PUT__DAY          UNDEFINED
#define _BT_LOG_MESSAGE_FORMAT_PUT__HOUR         UNDEFINED
#define _BT_LOG_MESSAGE_FORMAT_PUT__MINUTE       UNDEFINED
#define _BT_LOG_MESSAGE_FORMAT_PUT__SECOND       UNDEFINED
#define _BT_LOG_MESSAGE_FORMAT_PUT__MILLISECOND  UNDEFINED
#define _BT_LOG_MESSAGE_FORMAT_PUT__PID          UNDEFINED
#define _BT_LOG_MESSAGE_FORMAT_PUT__TID          UNDEFINED
#define _BT_LOG_MESSAGE_FORMAT_PUT__LEVEL        UNDEFINED
#define _BT_LOG_MESSAGE_FORMAT_PUT__TAG(pd, td)  PUT_TAG(msg, tag, pd, td);
#define _BT_LOG_MESSAGE_FORMAT_PUT__FUNCTION     msg->p = put_string(funcname(src->func), msg->p, msg->e);
#define _BT_LOG_MESSAGE_FORMAT_PUT__FILENAME     msg->p = put_string(filename(src->file), msg->p, msg->e);
#define _BT_LOG_MESSAGE_FORMAT_PUT__FILELINE     msg->p = put_uint(src->line, 0, '\0', msg->p, msg->e);
#define _BT_LOG_MESSAGE_FORMAT_PUT__S(s)         PUT_CSTR_CHECKED(msg->p, msg->e, s);
#define _BT_LOG_MESSAGE_FORMAT_PUT__F_INIT(expr)
#define _BT_LOG_MESSAGE_FORMAT_PUT__F_UINT(w, v) msg->p = put_uint(v, w, ' ', msg->p, msg->e);
#define _BT_LOG_MESSAGE_FORMAT_PUT(field) \
        _PP_CONCAT_3(_BT_LOG_MESSAGE_FORMAT_PUT_, _, field)

static void put_tag(bt_log_message *const msg, const char *const tag)
{
        _PP_MAP(_BT_LOG_MESSAGE_FORMAT_INIT, BT_LOG_MESSAGE_TAG_FORMAT)
#if !_BT_LOG_MESSAGE_FORMAT_CONTAINS(TAG, BT_LOG_MESSAGE_TAG_FORMAT)
        VAR_UNUSED(tag);
#endif
#if !_BT_LOG_MESSAGE_FORMAT_FIELDS(BT_LOG_MESSAGE_TAG_FORMAT)
        VAR_UNUSED(msg);
#else
        _PP_MAP(_BT_LOG_MESSAGE_FORMAT_PUT, BT_LOG_MESSAGE_TAG_FORMAT)
#endif
}

static void put_src(bt_log_message *const msg, const src_location *const src)
{
        _PP_MAP(_BT_LOG_MESSAGE_FORMAT_INIT, BT_LOG_MESSAGE_SRC_FORMAT)
#if !_BT_LOG_MESSAGE_FORMAT_CONTAINS(FUNCTION, BT_LOG_MESSAGE_SRC_FORMAT) && \
        !_BT_LOG_MESSAGE_FORMAT_CONTAINS(FILENAME, BT_LOG_MESSAGE_SRC_FORMAT) && \
        !_BT_LOG_MESSAGE_FORMAT_CONTAINS(FILELINE, BT_LOG_MESSAGE_SRC_FORMAT)
        VAR_UNUSED(src);
#endif
#if !_BT_LOG_MESSAGE_FORMAT_FIELDS(BT_LOG_MESSAGE_SRC_FORMAT)
        VAR_UNUSED(msg);
#else
        #if BT_LOG_OPTIMIZE_SIZE
        int n;
        n = snprintf(msg->p, nprintf_size(msg),
                                 _PP_MAP(_BT_LOG_MESSAGE_FORMAT_PRINTF_FMT, BT_LOG_MESSAGE_SRC_FORMAT)
                 _PP_MAP(_BT_LOG_MESSAGE_FORMAT_PRINTF_VAL, BT_LOG_MESSAGE_SRC_FORMAT));
        put_nprintf(msg, n);
        #else
        _PP_MAP(_BT_LOG_MESSAGE_FORMAT_PUT, BT_LOG_MESSAGE_SRC_FORMAT)
        #endif
#endif
}

static void put_msg(bt_log_message *const msg,
                                        const char *const fmt, va_list va)
{
        int n;
        msg->msg_b = msg->p;
        n = vsnprintf(msg->p, nprintf_size(msg), fmt, va);
        put_nprintf(msg, n);
}

static void output_mem(const bt_log_spec *log, bt_log_message *const msg,
                                           const mem_block *const mem)
{
        if (0 == mem->d || 0 == mem->d_sz)
        {
                return;
        }
        const unsigned char *mem_p = (const unsigned char *)mem->d;
        const unsigned char *const mem_e = mem_p + mem->d_sz;
        const unsigned char *mem_cut;
        const ptrdiff_t mem_width = (ptrdiff_t)log->format->mem_width;
        char *const hex_b = msg->msg_b;
        char *const ascii_b = hex_b + 2 * mem_width + 2;
        char *const ascii_e = ascii_b + mem_width;
        if (msg->e < ascii_e)
        {
                return;
        }
        while (mem_p != mem_e)
        {
                char *hex = hex_b;
                char *ascii = ascii_b;
                for (mem_cut = mem_width < mem_e - mem_p? mem_p + mem_width: mem_e;
                         mem_cut != mem_p; ++mem_p)
                {
                        const unsigned char ch = *mem_p;
                        *hex++ = c_hex[(0xf0 & ch) >> 4];
                        *hex++ = c_hex[(0x0f & ch)];
                        *ascii++ = isprint(ch)? (char)ch: '?';
                }
                while (hex != ascii_b)
                {
                        *hex++ = ' ';
                }
                msg->p = ascii;
                log->output->callback(msg, log->output->arg);
        }
}

BT_HIDDEN
void bt_log_set_tag_prefix(const char *const prefix)
{
        _bt_log_tag_prefix = prefix;
}

BT_HIDDEN
void bt_log_set_mem_width(const unsigned w)
{
        _bt_log_global_format.mem_width = w;
}

BT_HIDDEN
void bt_log_set_output_level(const int lvl)
{
        _bt_log_global_output_lvl = lvl;
}

BT_HIDDEN
void bt_log_set_output_v(const unsigned mask, void *const arg,
                                                 const bt_log_output_cb callback)
{
        _bt_log_global_output.mask = mask;
        _bt_log_global_output.arg = arg;
        _bt_log_global_output.callback = callback;
}

static void _bt_log_write_imp(
                const bt_log_spec *log,
                const src_location *const src, const mem_block *const mem,
                const int lvl, const char *const tag, const char *const fmt, va_list va)
{
        bt_log_message msg;
        char buf[BT_LOG_BUF_SZ];
        const unsigned mask = log->output->mask;
        msg.lvl = lvl;
        msg.tag = tag;
        g_buffer_cb(&msg, buf);
        const char *rst_color_p = bt_common_color_reset();
        const char *rst_color_e = rst_color_p + strlen(rst_color_p);
        const char *color_p = "";
        const char *color_e = color_p;

        switch (lvl) {
        case BT_LOG_INFO:
                color_p = bt_common_color_fg_blue();
                color_e = color_p + strlen(color_p);
                break;
        case BT_LOG_WARN:
                color_p = bt_common_color_fg_yellow();
                color_e = color_p + strlen(color_p);
                break;
        case BT_LOG_ERROR:
        case BT_LOG_FATAL:
                color_p = bt_common_color_fg_red();
                color_e = color_p + strlen(color_p);
                break;
        default:
                break;
        }

        msg.p = put_stringn(color_p, color_e, msg.p, msg.e);

        if (BT_LOG_PUT_CTX & mask)
        {
                put_ctx(&msg);
        }
        if (BT_LOG_PUT_TAG & mask)
        {
                put_tag(&msg, tag);
        }
        if (0 != src && BT_LOG_PUT_SRC & mask)
        {
                put_src(&msg, src);
        }
        if (BT_LOG_PUT_MSG & mask)
        {
                put_msg(&msg, fmt, va);
        }
        msg.p = put_stringn(rst_color_p, rst_color_e, msg.p, msg.e);
        log->output->callback(&msg, log->output->arg);
        if (0 != mem && BT_LOG_PUT_MSG & mask)
        {
                output_mem(log, &msg, mem);
        }
}

BT_HIDDEN
void _bt_log_write_d(
                const char *const func, const char *const file, const unsigned line,
                const int lvl, const char *const tag,
                const char *const fmt, ...)
{
        const src_location src = {func, file, line};
        va_list va;
        va_start(va, fmt);
        _bt_log_write_imp(&global_spec, &src, 0, lvl, tag, fmt, va);
        va_end(va);
}

BT_HIDDEN
void _bt_log_write_aux_d(
                const char *const func, const char *const file, const unsigned line,
                const bt_log_spec *const log, const int lvl, const char *const tag,
                const char *const fmt, ...)
{
        const src_location src = {func, file, line};
        va_list va;
        va_start(va, fmt);
        _bt_log_write_imp(log, &src, 0, lvl, tag, fmt, va);
        va_end(va);
}

BT_HIDDEN
void _bt_log_write(const int lvl, const char *const tag,
                                   const char *const fmt, ...)
{
        va_list va;
        va_start(va, fmt);
        _bt_log_write_imp(&global_spec, 0, 0, lvl, tag, fmt, va);
        va_end(va);
}

BT_HIDDEN
void _bt_log_write_aux(
                const bt_log_spec *const log, const int lvl, const char *const tag,
                const char *const fmt, ...)
{
        va_list va;
        va_start(va, fmt);
        _bt_log_write_imp(log, 0, 0, lvl, tag, fmt, va);
        va_end(va);
}

BT_HIDDEN
void _bt_log_write_mem_d(
                const char *const func, const char *const file, const unsigned line,
                const int lvl, const char *const tag,
                const void *const d, const unsigned d_sz,
                const char *const fmt, ...)
{
        const src_location src = {func, file, line};
        const mem_block mem = {d, d_sz};
        va_list va;
        va_start(va, fmt);
        _bt_log_write_imp(&global_spec, &src, &mem, lvl, tag, fmt, va);
        va_end(va);
}

BT_HIDDEN
void _bt_log_write_mem_aux_d(
                const char *const func, const char *const file, const unsigned line,
                const bt_log_spec *const log, const int lvl, const char *const tag,
                const void *const d, const unsigned d_sz,
                const char *const fmt, ...)
{
        const src_location src = {func, file, line};
        const mem_block mem = {d, d_sz};
        va_list va;
        va_start(va, fmt);
        _bt_log_write_imp(log, &src, &mem, lvl, tag, fmt, va);
        va_end(va);
}

BT_HIDDEN
void _bt_log_write_mem(const int lvl, const char *const tag,
                                           const void *const d, const unsigned d_sz,
                                           const char *const fmt, ...)
{
        const mem_block mem = {d, d_sz};
        va_list va;
        va_start(va, fmt);
        _bt_log_write_imp(&global_spec, 0, &mem, lvl, tag, fmt, va);
        va_end(va);
}

BT_HIDDEN
void _bt_log_write_mem_aux(
                const bt_log_spec *const log, const int lvl, const char *const tag,
                const void *const d, const unsigned d_sz,
                const char *const fmt, ...)
{
        const mem_block mem = {d, d_sz};
        va_list va;
        va_start(va, fmt);
        _bt_log_write_imp(log, 0, &mem, lvl, tag, fmt, va);
        va_end(va);
}