C语言 如何在宏定义中使用可变参数
有一个记录日志的函数,想用宏定义进行包装，简化调用方法，但是xlc报如下的错误：
void _log(const int level, char* file, int line, const char* fmt, ...){
va_list ap;
int count;
time_t t;
struct tm* st;
char str_time[255];
memset(str_time, 0x00, sizeof(str_time));
time(&t);
st= localtime(&t);
switch(level){
case DEBUG:
fprintf(stdout, "[DEBUG] ");
break;
case INFO:
fprintf(stdout, "[INFO] ");
break;
case WARNING:
fprintf(stdout, "[WARNING] ");
break;
case ERROR:
fprintf(stdout, "[ERROR] ");
break;
default:
fprintf(stdout, "[INFO] ");
break;
}
strftime( str_time, sizeof(str_time), "%Y-%m-%d %H:%M:%S", st);
fprintf(stdout, "[%s] LINE:[%04d] [%s] ", file, line, str_time);
va_start(ap, fmt);
count = vfprintf(stdout, fmt, ap);
fprintf(stdout, "\n");
fflush(stdout);
va_end(ap);
}
#define log_info(...) _log((INFO), (__FILE__), (__LINE__), "", (#__VA_ARGS__))
#define log_err(...) _log((ERROR), (__FILE__), (__LINE__), "", (#__VA_ARGS__))
Syntax error at line 71, column 18, file RProCrminfo.cp:
Error at line 71, column 18 in file RProCrminfo.cpdefine log_info((aaa), ...) _log((INFO), (__FILE__), (__LINE__), "", (#__VA_ARG
S__))
.................1
PCC-S-02014, Encountered the symbol "(" when expecting one of the following:
) ... an identifier, define, elif, else, endif, error, if,
ifdef, ifndef, include, line, pragma, undef, exec, sql,
begin, end, var, type, oracle,
an immediate preprocessor command, a C token, create,
function, package, procedure, trigger, or, replace,
The symbol ")" was substituted for "(" to continue.
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#define FM_LOG_DEBUG(x...) log_write(LOG_DEBUG, __FILE__, __LINE__, ##x) static void log_write(int level, const char *file, const int line, const char *fmt, ...) { if (log_opened == 0) { fprintf(stderr, "log_open not called yet\n"); exit(1); } static char buffer[log_buffer_size]; static char datetime[100]; static char line_str[20]; static time_t now; now = time(NULL); strftime(datetime, 99, "%Y-%m-%d %H:%M:%S", localtime(&now)); snprintf(line_str, 19, "%d", line); va_list ap; va_start(ap, fmt); vsnprintf(log_buffer, log_buffer_size, fmt, ap); va_end(ap); size_t count = snprintf(buffer, log_buffer_size, "%s\x7 [%s]\x7 [%s:%d]%s\x7 %s\x7\n", LOG_LEVEL_NOTE[level], datetime, file, line, log_extra_info, log_buffer); int log_fd = log_fp->_fileno; //puts(buffer); if (flock(log_fd, LOCK_EX) == 0) { if (write(log_fd, buffer, count) < 0) { perror("write error"); exit(1); } flock(log_fd, LOCK_UN); } else { perror("flock error"); exit(1); } }2019-07-17 19:27:10赞同 展开评论
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