le_log.h

    1 /**
    2  * @page c_logging Logging API
    3  *
    4  * @subpage le_log.h "API Reference" <br>
    5  *
    6  * The Legato Logging API provides a toolkit allowing code to be instrumented with error, warning,
    7  * informational, and debugging messages. These messages can be turned on or off remotely and pushed or pulled
    8  * from the device through a secure shell, cloud services interfaces, e-mail, SMS, etc.
    9  *
   10  * @section c_log_logging Logging Basics
   11  *
   12  * Legato's logging can be configured through this API, and there's also a command-line target
   13  * @ref toolsTarget_log tool available.
   14  *
   15  * @subsection c_log_levels Levels
   16  *
   17  * Log messages are categorized according to the severity of the information being logged.
   18  * A log message may be purely informational, describing something that is
   19  * expected to occur from time-to-time during normal operation; or it may be a report of a fault
   20  * that might have a significant negative impact on the operation of the system.  To
   21  * differentiate these, each log entry is associated with one of the following log levels:
   22  *
   23  *  - @ref LE_LOG_DEBUG "DEBUG":
   24  *    Handy for troubleshooting.
   25  *  - @ref LE_LOG_INFO "INFORMATION":
   26  *    Expected to happen; can be interesting even when not troubleshooting.
   27  *  - @ref LE_LOG_WARN "WARNING":
   28  *    Should not normally happen; may not have any real impact on system performance.
   29  *  - @ref LE_LOG_ERR "ERROR":
   30  *    Fault that may result in noticeable short-term system misbehaviour. Needs attention.
   31  *  - @ref LE_LOG_CRIT "CRITICAL":
   32  *    Fault needs urgent attention. Will likely result in system failure.
   33  *  - @ref LE_LOG_EMERG "EMERGENCY":
   34  *    Definite system failure.
   35  *
   36  * @subsection c_log_basic_defaultSyslog Standard Out and Standard Error in Syslog
   37  *
   38  * By default, app processes will have their @c stdout and @c stderr redirected to the @c syslog. Each
   39  * process’s stdout will be logged at INFO severity level; it’s stderr will be logged at
   40  * “ERR” severity level.
   41 
   42  * There are two limitations with this feature:
   43  * - the PID reported in the logs generally refer to the PID of the process that
   44  * generates the stdout/stderr message. If a process forks, then both the parent and
   45  * child processes’ stdout/stderr will share the same connection to the syslog, and the parent’s
   46  * PID will be reported in the logs for both processes.
   47  * - stdout is line buffered when connected to a terminal, which means
   48  * <code>printf(“hello\n”)</code> will be printed to the terminal immediately. If stdout is
   49  * connected to something like a pipe it's bulk buffered, which means a flush doesn't occur until the buffer is full.
   50  *
   51  * To make your process line buffer stdout so that printf will show up in the logs as expected,
   52  * the @c setlinebuf(stdout) system call can be used.  Alternatively, @c fflush(stdout) can be called \
   53  * to force a flush of the stdout buffer.
   54  *
   55  * This issue doesn't exist with stderr as stderr is never buffered.
   56  *
   57  * @subsection c_log_basic_logging Basic Logging
   58  *
   59  * A series of macros are available to make logging easy.
   60  *
   61  * None of them return anything.
   62  *
   63  * All of them accept printf-style arguments, consisting of a format string followed by zero or more
   64  * parameters to be printed (depending on the contents of the format string).
   65  *
   66  * There is a logging macro for each of the log levels:
   67  *
   68  *  - @ref LE_DEBUG(formatString, ...)
   69  *  - @ref LE_INFO(formatString, ...)
   70  *  - @ref LE_WARN(formatString, ...)
   71  *  - @ref LE_ERROR(formatString, ...)
   72  *  - @ref LE_CRIT(formatString, ...)
   73  *  - @ref LE_EMERG(formatString, ...)
   74  *
   75  * For example,
   76  * @code
   77  * LE_INFO("Obtained new IP address %s.", ipAddrStr);
   78  * @endcode
   79  *
   80  * @subsection c_log_conditional_logging Conditional Logging
   81  *
   82  * Similar to the basic macros, but these contain a conditional expression as their first parameter.  If this expression equals
   83  * true, then the macro will generate this log output:
   84  *
   85  *  - @ref LE_DEBUG_IF(expression, formatString, ...)
   86  *  - @ref LE_INFO_IF(expression, formatString, ...)
   87  *  - @ref LE_WARN_IF(expression, formatString, ...)
   88  *  - @ref LE_ERROR_IF(expression, formatString, ...)
   89  *  - @ref LE_CRIT_IF(expression, formatString, ...)
   90  *  - @ref LE_EMERG_IF(expression, formatString, ...)
   91  *
   92  * Instead of writing
   93  * @code
   94  * if (result == -1)
   95  * {
   96  *     LE_WARN("Failed to send message to server.  Errno = %d.", errno);
   97  * }
   98  * @endcode
   99  *
  100  * you could write this:
  101  * @code
  102  * LE_WARN_IF(result == -1, "Failed to send message to server.  Errno = %d.", errno);
  103  * @endcode
  104  *
  105  * @subsection c_log_loging_fatals Fatal Errors
  106  *
  107  * There are some special logging macros intended for fatal errors:
  108  *
  109  *  - @ref LE_FATAL(formatString, ...) \n
  110  *    Always kills the calling process after logging the message at EMERGENCY level (never returns).
  111  *  - @ref LE_FATAL_IF(condition, formatString, ...) \n
  112  *    If the condition is true, kills the calling process after logging the message at EMERGENCY
  113  *    level.
  114  *  - @ref LE_ASSERT(condition) \n
  115  *    If the condition is true, does nothing. If the condition is false, logs the source
  116  *    code text of the condition at EMERGENCY level and kills the calling process.
  117  *  - @ref LE_ASSERT_OK(condition) \n
  118  *    If the condition is LE_OK (0), does nothing. If the condition is anything else, logs the
  119  *    a message at EMERGENCY level, containing the source code text of the condition, indicating
  120  *    that it did not evaluate to LE_OK, and kills the calling process.
  121  *
  122  * For example,
  123  * @code
  124  * if (NULL == objPtr)
  125  * {
  126  *     LE_FATAL("Object pointer is NULL!");
  127  * }
  128  *
  129  * // Now I can go ahead and use objPtr, knowing that if it was NULL then LE_FATAL() would have
  130  * // been called and LE_FATAL() never returns.
  131  * @endcode
  132  *
  133  * or,
  134  *
  135  * @code
  136  * LE_FATAL_IF(NULL == objPtr, "Object pointer is NULL!");
  137  *
  138  * // Now I can go ahead and use objPtr, knowing that if it was NULL then LE_FATAL_IF() would not
  139  * // have returned.
  140  * @endcode
  141  *
  142  * or,
  143  *
  144  * @code
  145  * LE_ASSERT(NULL != objPtr);
  146  *
  147  * // Now I can go ahead and use objPtr, knowing that if it was NULL then LE_ASSERT() would not
  148  * // have returned.
  149  * @endcode
  150  *
  151  * @subsection c_log_tracing Tracing
  152  *
  153  * Finally, a macro is provided for tracing:
  154  *
  155  *  - @ref LE_TRACE(traceRef, string, ...)
  156  *
  157  * This macro is special because it's independent of log level.  Instead, trace messages are
  158  * associated with a trace keyword.  Tracing can be enabled and disabled based on these keywords.
  159  *
  160  * If a developer wanted to trace the creation of "shape"
  161  * objects in their GUI package, they could add trace statements like the following:
  162  *
  163  * @code
  164  * LE_TRACE(NewShapeTraceRef, "Created %p with position (%d,%d).", shapePtr, shapePtr->x, shapePtr->y);
  165  * @endcode
  166  *
  167  * The reference to the trace is obtained at start-up as follows:
  168  *
  169  * @code
  170  * NewShapeTraceRef = le_log_GetTraceRef("newShape");
  171  * @endcode
  172  *
  173  * This allows enabling and disabling these LE_TRACE() calls using the "newShape" keyword
  174  * through configuration settings and runtime log control tools.  See @ref c_log_controlling below.
  175  *
  176  * Applications can use @ref LE_IS_TRACE_ENABLED(NewShapeTraceRef) to query whether
  177  * a trace keyword is enabled.
  178  *
  179  * These allow apps to hook into the trace management system to use it to implement
  180  * sophisticated, app-specific tracing or profiling features.
  181  *
  182  * @subsection c_log_resultTxt Result Code Text
  183  *
  184  * The @ref le_result_t macro supports printing an error condition in a human-readable text string.
  185  *
  186  * @code
  187  * result = le_foo_DoSomething();
  188  *
  189  * if (result != LE_OK)
  190  * {
  191  *     LE_ERROR("Failed to do something. Result = %d (%s).", result, LE_RESULT_TXT(result));
  192  * }
  193  * @endcode
  194  *
  195  *
  196  * @section c_log_controlling Log Controls
  197  *
  198  * Log level filtering and tracing can be controlled at runtime using:
  199  *  - the command-line Log Control Tool (@ref toolsTarget_log)
  200  *  - configuration settings
  201  *  - environment variables
  202  *  - function calls.
  203  *
  204  * @subsection c_log_control_tool Log Control Tool
  205  *
  206  * The log control tool is used from the command-line to control the log
  207  * level filtering, log output location (syslog/stderr), and tracing for different components
  208  * within a running system.
  209  *
  210  * Online documentation can be accessed from the log control tool by running "log help".
  211  *
  212  * Here are some code samples.
  213  *
  214  * To set the log level to INFO for a component "myComp" running in all processes with the
  215  * name "myProc":
  216  * @verbatim
  217 $ log level INFO myProc/myComp
  218 @endverbatim
  219  *
  220  * To set the log level to DEBUG for a component "myComp" running in a process with PID 1234:
  221  * @verbatim
  222 $ log level DEBUG 1234/myComp
  223 @endverbatim
  224  *
  225  * To enable all LE_TRACE statements tagged with the keyword "foo" in a component called "myComp"
  226  * running in all processes called "myProc":
  227  * @verbatim
  228 $ log trace foo myProc/myComp
  229 @endverbatim
  230  *
  231  * To disable the trace statements tagged with "foo" in the component "myComp" in processes
  232  * called "myProc":
  233  * @verbatim
  234 $ log stoptrace foo myProc/myComp
  235 @endverbatim
  236  *
  237  * With all of the above examples "*" can be used in place of the process name or a component
  238  * name (or both) to mean "all processes" and/or "all components".
  239  *
  240  * @subsection c_log_control_config Log Control Configuration Settings
  241  *
  242  * @note The configuration settings haven't been implemented yet.
  243  *
  244  * @todo Write @ref c_log_control_config section.
  245  *
  246  * @subsection c_log_control_environment_vars Environment Variables
  247  *
  248  * Environment variables can be used to control the default log settings, taking effect immediately
  249  * at process start-up; even before the Log Control Daemon has been connected to.
  250  *
  251  * Settings in the Log Control Daemon (applied through configuration and/or the log control tool)
  252  * will override the environment variable settings when the process connects to the Log
  253  * Control Daemon.
  254  *
  255  * @subsubsection c_log_control_env_level LE_LOG_LEVEL
  256  *
  257  * @c LE_LOG_LEVEL can be used to set the default log filter level for all components
  258  * in the process.  Valid values are:
  259  *
  260  * - @c EMERGENCY
  261  * - @c CRITICAL
  262  * - @c ERROR
  263  * - @c WARNING
  264  * - @c INFO
  265  * - @c DEBUG
  266  *
  267  * For example,
  268  * @verbatim
  269 $ export LE_LOG_LEVEL=DEBUG
  270 @endverbatim
  271  *
  272  * @subsubsection c_log_control_env_trace LE_LOG_TRACE
  273  *
  274  * @c LE_LOG_TRACE allows trace keywords to be enabled by default.  The contents of this
  275  * variable is a colon-separated list of keywords that should be enabled. Each keyword
  276  * must be prefixed with a component name followed by a slash ('/').
  277  *
  278  * For example,
  279  * @verbatim
  280 $ export LE_LOG_TRACE=framework/fdMonitor:framework/logControl
  281 @endverbatim
  282  *
  283  * @subsection c_log_control_functions Programmatic Log Control
  284  *
  285  * Normally, configuration settings and the log control tool should suffice for controlling
  286  * logging functionality.  In some situations, it can be convenient
  287  * to control logging programmatically in C.
  288  *
  289  * le_log_SetFilterLevel() sets the log filter level.
  290  *
  291  * le_log_GetFilterLevel() gets the log filter level.
  292  *
  293  * Trace keywords can be enabled and disabled programmatically by calling
  294  * @subpage le_log_EnableTrace() and @ref le_log_DisableTrace().
  295  *
  296  *
  297  * @section c_log_format Log Formats
  298  *
  299  * Log entries can also contain any of these:
  300  *  - timestamp (century, year, month, day, hours, minutes, seconds, milliseconds, microseconds)
  301  *  - level (debug, info, warning, etc.) @b or trace keyword
  302  *  - process ID
  303  *  - component name
  304  *  - thread name
  305  *  - source code file name
  306  *  - function name
  307  *  - source code line number
  308  *
  309  * Log messages have the following format:
  310  *
  311  * @verbatim
  312 Jan  3 02:37:56  INFO  | processName[pid]/componentName T=threadName | fileName.c funcName() lineNum | Message
  313 @endverbatim
  314  *
  315  * @section c_log_debugFiles App Crash Logs
  316 
  317 * When a process within an app faults or exits in error, a copy of the current syslog buffer
  318 * is captured along with a core file of the process crash (if generated).
  319 
  320 * The core file maximum size is determined by the process settings @c maxCoreDumpFileBytes and
  321 * @c maxFileBytes found in the processes section of your app's @c .adef file.  By default, the
  322 * @c maxCoreDumpFileBytes is set to 0, do not create a core file.
  323 
  324 * To help save the target from flash burnout, the syslog and core files are stored in the RAM
  325 * FS under /tmp.  When a crash occurs, this directory is created:
  326 
  327  @verbatim
  328  /tmp/legato_logs/
  329  @endverbatim
  330 
  331 * The files in that directory look like this:
  332 
  333  @verbatim
  334  core-myProc-1418694851
  335  syslog-myApp-myProc-1418694851
  336  @endverbatim
  337 
  338 * To save on RAM space, only the most recent 4 copies of each file are preserved.
  339 
  340 * If the fault action for that app's process is to reboot the target, the output location is changed to
  341 * this (and the most recent files in RAM space are preserved across reboots):
  342 
  343  @verbatim
  344  /mnt/flash/legato_logs/
  345  @endverbatim
  346 
  347 *
  348  * @todo May need to support log format configuration through command-line arguments or a
  349  *       configuration file.
  350  *
  351  * @todo Write @ref c_log_retrieving section
  352  *
  353  * <HR>
  354  *
  355  * Copyright (C) Sierra Wireless Inc.
  356  */
  357 
  358 
  359 /** @file le_log.h
  360  *
  361  * Legato @ref c_logging include file.
  362  *
  363  * Copyright (C) Sierra Wireless Inc.
  364  */
  365 
  366 #ifndef LEGATO_LOG_INCLUDE_GUARD
  367 #define LEGATO_LOG_INCLUDE_GUARD
  368 
  369 //--------------------------------------------------------------------------------------------------
  370 /**
  371  * Local definitions that should not be used directly.
  372  */
  373 //--------------------------------------------------------------------------------------------------
  374 typedef enum _le_log_Level_t
  375 {
  376     LE_LOG_DEBUG,   ///< Debug message.
  377     LE_LOG_INFO,    ///< Informational message.  Normally expected.
  378     LE_LOG_WARN,    ///< Warning.  Possibly indicates a problem.  Should be addressed.
  379     LE_LOG_ERR,     ///< Error.  Definitely indicates a  fault that needs to be addressed.
  380                     ///  Possibly resulted in a system failure.
  381     LE_LOG_CRIT,    ///< Critical error.  Fault that almost certainly has or will result in a
  382                     ///  system failure.
  383     LE_LOG_EMERG,   ///< Emergency.  A fatal error has occurred.  A process is being terminated.
  384     LE_LOG_MAX      ///< One beyond maximum log level
  385 }
  386 le_log_Level_t;
  387 
  388 //--------------------------------------------------------------------------------------------------
  389 /**
  390  * Compile-time filtering level.
  391  *
  392  * @note Logs below this filter level will be removed at compile-time and cannot be enabled
  393  *       at runtime.
  394  */
  395 //--------------------------------------------------------------------------------------------------
  396 #if LE_CONFIG_LOG_STATIC_FILTER_NO_LOG
  397 #   define LE_LOG_LEVEL_STATIC_FILTER   LE_LOG_MAX
  398 #elif LE_CONFIG_LOG_STATIC_FILTER_EMERG
  399 #   define LE_LOG_LEVEL_STATIC_FILTER   LE_LOG_EMERG
  400 #elif LE_CONFIG_LOG_STATIC_FILTER_CRIT
  401 #   define LE_LOG_LEVEL_STATIC_FILTER   LE_LOG_CRIT
  402 #elif LE_CONFIG_LOG_STATIC_FILTER_ERR
  403 #   define LE_LOG_LEVEL_STATIC_FILTER   LE_LOG_ERR
  404 #elif LE_CONFIG_LOG_STATIC_FILTER_WARN
  405 #   define LE_LOG_LEVEL_STATIC_FILTER   LE_LOG_WARN
  406 #elif LE_CONFIG_LOG_STATIC_FILTER_INFO
  407 #   define LE_LOG_LEVEL_STATIC_FILTER   LE_LOG_INFO
  408 #else /* default to LE_DEBUG */
  409 #   define LE_LOG_LEVEL_STATIC_FILTER   LE_LOG_DEBUG
  410 #endif
  411 
  412 //--------------------------------------------------------------------------------------------------
  413 /// @cond HIDDEN_IN_USER_DOCS
  414 
  415 typedef struct le_log_Session* le_log_SessionRef_t;
  416 
  417 typedef struct le_log_Trace* le_log_TraceRef_t;
  418 
  419 #if !defined(LE_DEBUG) && \
  420     !defined(LE_DUMP) && \
  421     !defined(LE_LOG_DUMP) && \
  422     !defined(LE_INFO) && \
  423     !defined(LE_WARN) && \
  424     !defined(LE_ERROR) && \
  425     !defined(LE_CRIT) && \
  426     !defined(LE_EMERG)
  427 
  428 /// Default log implementation is in use.
  429 #   define LE_LOG_DEFAULT_IMPL 1
  430 
  431 //--------------------------------------------------------------------------------------------------
  432 /**
  433  * Send a message to the logging target.
  434  **/
  435 //--------------------------------------------------------------------------------------------------
  436 void _le_log_Send
  437 (
  438     const le_log_Level_t     level,             ///< Log level.
  439     const le_log_TraceRef_t  traceRef,          ///< Trace reference.  May be NULL.
  440     le_log_SessionRef_t      logSession,        ///< Log session.  May be NULL.
  441     const char              *filenamePtr,       ///< File name.
  442     const char              *functionNamePtr,   ///< Function name.  May be NULL.
  443     const unsigned int       lineNumber,        ///< Line number.
  444     const char              *formatPtr,         ///< Format string.
  445     ...                                         ///< Positional parameters.
  446 ) __attribute__((format (printf, 7, 8)));
  447 
  448 //--------------------------------------------------------------------------------------------------
  449 /**
  450  * Log data block.  Provides a hex dump for debug.
  451  */
  452 //--------------------------------------------------------------------------------------------------
  453 void _le_LogData
  454 (
  455     le_log_Level_t       level,             ///< Log level.
  456     const uint8_t       *dataPtr,           ///< The buffer address to be dumped.
  457     int                  dataLength,        ///< The data length of buffer.
  458     const char          *filenamePtr,       ///< The name of the source file that logged the
  459                                             ///< message.
  460     const char          *functionNamePtr,   ///< The name of the function that logged the message.
  461     const unsigned int   lineNumber         ///< The line number in the source file that logged the
  462                                             ///< message.
  463 );
  464 
  465 //--------------------------------------------------------------------------------------------------
  466 /**
  467  * Gets a reference to a trace keyword's settings.
  468  *
  469  * @return  Trace reference.
  470  **/
  471 //--------------------------------------------------------------------------------------------------
  472 le_log_TraceRef_t _le_log_GetTraceRef
  473 (
  474     le_log_SessionRef_t  logSession,    ///< Log session.
  475     const char          *keyword        ///< Trace keyword.
  476 );
  477 
  478 //--------------------------------------------------------------------------------------------------
  479 /**
  480  * Sets the log filter level for the calling component.
  481  **/
  482 //--------------------------------------------------------------------------------------------------
  483 void _le_log_SetFilterLevel
  484 (
  485     le_log_SessionRef_t logSession, ///< Log session.
  486     le_log_Level_t      level       ///< Log level to apply.
  487 );
  488 
  489 //--------------------------------------------------------------------------------------------------
  490 /**
  491  * Filtering session reference for the current source file.
  492  *
  493  * @note The real name of this is passed in by the build system. This way it can be a unique
  494  *       variable for each component.
  495  */
  496 //--------------------------------------------------------------------------------------------------
  497 extern LE_SHARED le_log_SessionRef_t LE_LOG_SESSION;
  498 
  499 //--------------------------------------------------------------------------------------------------
  500 /**
  501  * Filtering level for the current source file.
  502  *
  503  * @note The real name of this is passed in by the build system. This way it can be a unique
  504  *       variable for each component.
  505  */
  506 //--------------------------------------------------------------------------------------------------
  507 extern LE_SHARED le_log_Level_t* LE_LOG_LEVEL_FILTER_PTR;
  508 
  509 //--------------------------------------------------------------------------------------------------
  510 /**
  511  * Internal macro to set whether the function name is displayed with log messages.
  512  */
  513 //--------------------------------------------------------------------------------------------------
  514 #if LE_CONFIG_LOG_FUNCTION_NAMES
  515 #   define _LE_LOG_FUNCTION_NAME __func__
  516 #else
  517 #   define _LE_LOG_FUNCTION_NAME NULL
  518 #endif
  519 
  520 /// @endcond
  521 //--------------------------------------------------------------------------------------------------
  522 
  523 //--------------------------------------------------------------------------------------------------
  524 /**
  525  * Internal macro to filter out messages that do not meet the current filtering level.
  526  */
  527 //--------------------------------------------------------------------------------------------------
  528 #define _LE_LOG_MSG(level, formatString, ...) \
  529     do { \
  530         if ((level >= LE_LOG_LEVEL_STATIC_FILTER) &&                        \
  531             ((LE_LOG_LEVEL_FILTER_PTR == NULL) || (level >= *LE_LOG_LEVEL_FILTER_PTR))) \
  532             _le_log_Send(level, NULL, LE_LOG_SESSION, __FILE__, _LE_LOG_FUNCTION_NAME, __LINE__, \
  533                     formatString, ##__VA_ARGS__); \
  534     } while(0)
  535 
  536 
  537 //--------------------------------------------------------------------------------------------------
  538 /** @internal
  539  * The following macros are used to send log messages at different severity levels:
  540  *
  541  * Accepts printf-style arguments, consisting of a format string followed by zero or more parameters
  542  * to be printed (depending on the contents of the format string).
  543  */
  544 //--------------------------------------------------------------------------------------------------
  545 
  546 /** @copydoc LE_LOG_DEBUG */
  547 #define LE_DEBUG(formatString, ...)     _LE_LOG_MSG(LE_LOG_DEBUG, formatString, ##__VA_ARGS__)
  548 
  549 //--------------------------------------------------------------------------------------------------
  550 /**
  551  * Dump a buffer of data as hexadecimal to the log at debug level.
  552  *
  553  *  @param  dataPtr     Binary data to dump.
  554  *  @param  dataLength  Length og the buffer.
  555  */
  556 //--------------------------------------------------------------------------------------------------
  557 #define LE_DUMP(dataPtr, dataLength)                                                              \
  558     _le_LogData(LE_LOG_DEBUG, dataPtr, dataLength, STRINGIZE(LE_FILENAME), _LE_LOG_FUNCTION_NAME, \
  559         __LINE__)
  560 
  561 //--------------------------------------------------------------------------------------------------
  562 /**
  563  * Dump a buffer of data as hexadecimal to the log at the specified level.
  564  *
  565  *  @param  level       Log level.
  566  *  @param  dataPtr     Binary data to dump.
  567  *  @param  dataLength  Length of the buffer.
  568  */
  569 //--------------------------------------------------------------------------------------------------
  570 #define LE_LOG_DUMP(level, dataPtr, dataLength) \
  571     _le_LogData(level, dataPtr, dataLength, STRINGIZE(LE_FILENAME), _LE_LOG_FUNCTION_NAME, __LINE__)
  572 /** @copydoc LE_LOG_INFO */
  573 #define LE_INFO(formatString, ...)      _LE_LOG_MSG(LE_LOG_INFO, formatString, ##__VA_ARGS__)
  574 /** @copydoc LE_LOG_WARN */
  575 #define LE_WARN(formatString, ...)      _LE_LOG_MSG(LE_LOG_WARN, formatString, ##__VA_ARGS__)
  576 /** @copydoc LE_LOG_ERR */
  577 #define LE_ERROR(formatString, ...)     _LE_LOG_MSG(LE_LOG_ERR, formatString, ##__VA_ARGS__)
  578 /** @copydoc LE_LOG_CRIT */
  579 #define LE_CRIT(formatString, ...)      _LE_LOG_MSG(LE_LOG_CRIT, formatString, ##__VA_ARGS__)
  580 /** @copydoc LE_LOG_EMERG */
  581 #define LE_EMERG(formatString, ...)     _LE_LOG_MSG(LE_LOG_EMERG, formatString, ##__VA_ARGS__)
  582 
  583 
  584 //--------------------------------------------------------------------------------------------------
  585 /**
  586  * Mark tracing as used, so trace-related code can be compiled in.
  587  */
  588 //--------------------------------------------------------------------------------------------------
  589 #define LE_LOG_CAN_TRACE        1
  590 
  591 
  592 //--------------------------------------------------------------------------------------------------
  593 /**
  594  * Queries whether or not a trace keyword is enabled.
  595  *
  596  * @return
  597  *      true if the keyword is enabled.
  598  *      false otherwise.
  599  */
  600 //--------------------------------------------------------------------------------------------------
  601 #define LE_IS_TRACE_ENABLED(traceRef)  (le_log_IsTraceEnabled(traceRef))
  602 
  603 
  604 //--------------------------------------------------------------------------------------------------
  605 /**
  606  * Logs the string if the keyword has been enabled by a runtime tool or configuration setting.
  607  */
  608 //--------------------------------------------------------------------------------------------------
  609 #define LE_TRACE(traceRef, string, ...)         \
  610         if (le_log_IsTraceEnabled(traceRef))    \
  611         {                                       \
  612             _le_log_Send((le_log_Level_t)-1,    \
  613                     traceRef,                   \
  614                     LE_LOG_SESSION,             \
  615                     STRINGIZE(LE_FILENAME),     \
  616                     _LE_LOG_FUNCTION_NAME,      \
  617                     __LINE__,                   \
  618                     string,                     \
  619                     ##__VA_ARGS__);             \
  620         }
  621 
  622 
  623 //--------------------------------------------------------------------------------------------------
  624 /**
  625  * Gets a reference to a trace keyword's settings.
  626  *
  627  * @param keywordPtr   [IN] Pointer to the keyword string.
  628  *
  629  * @return  Trace reference.
  630  **/
  631 //--------------------------------------------------------------------------------------------------
  632 #define le_log_GetTraceRef(keywordPtr)                  \
  633     _le_log_GetTraceRef(LE_LOG_SESSION, (keywordPtr))
  634 
  635 
  636 //--------------------------------------------------------------------------------------------------
  637 /**
  638  * Determines if a trace is currently enabled.
  639  *
  640  * @param traceRef    [IN] Trace reference obtained from le_log_GetTraceRef()
  641  *
  642  * @return  true if enabled, false if not.
  643  **/
  644 //--------------------------------------------------------------------------------------------------
  645 #define le_log_IsTraceEnabled(traceRef) ((traceRef) == NULL ? false : *((bool *) (traceRef)))
  646 
  647 
  648 //--------------------------------------------------------------------------------------------------
  649 /**
  650  * Sets the log filter level for the calling component.
  651  *
  652  * @note    Normally not necessary as the log filter level can be controlled at
  653  *          runtime using the log control tool, and can be persistently configured.
  654  *          See @ref c_log_controlling.
  655  *
  656  * @param level   [IN] Log filter level to apply to the current log session.
  657  **/
  658 //--------------------------------------------------------------------------------------------------
  659 #define le_log_SetFilterLevel(level)                    \
  660     _le_log_SetFilterLevel(LE_LOG_SESSION, (level))
  661 
  662 
  663 //--------------------------------------------------------------------------------------------------
  664 /**
  665  * Gets the log filter level for the calling component.
  666  **/
  667 //--------------------------------------------------------------------------------------------------
  668 #define le_log_GetFilterLevel()                 \
  669     ((LE_LOG_LEVEL_FILTER_PTR != NULL)?(*LE_LOG_LEVEL_FILTER_PTR):(LE_LOG_INFO))
  670 
  671 
  672 //--------------------------------------------------------------------------------------------------
  673 /**
  674  * Enables a trace.
  675  *
  676  * @note    Normally, this is not necessary, since traces can be enabled at runtime using the
  677  *          log control tool and can be persistently configured.  See @ref c_log_controlling.
  678  *
  679  * @param traceRef    [IN] Trace reference obtained from le_log_GetTraceRef()
  680  *
  681  **/
  682 //--------------------------------------------------------------------------------------------------
  683 #define le_log_EnableTrace(traceRef)            \
  684     ((void)(*((bool*)(traceRef)) = true))
  685 
  686 
  687 //--------------------------------------------------------------------------------------------------
  688 /**
  689  * Disables a trace.
  690  *
  691  * @note    Normally, this is not necessary, since traces can be enabled at runtime using the
  692  *          log control tool and can be persistently configured.  See @ref c_log_controlling.
  693  *
  694  * @param traceRef    [IN] Trace reference obtained from le_log_GetTraceRef()
  695  *
  696  **/
  697 //--------------------------------------------------------------------------------------------------
  698 #define le_log_DisableTrace(traceRef)           \
  699     ((void)(*((bool*)(traceRef)) = false))
  700 
  701 #else
  702 
  703 // If any logging macro is overridden, all logging macros must be overridden.
  704 #if !defined(LE_DEBUG)
  705 #  error "Logging are overridden, but LE_DEBUG not defined.  Define LE_DEBUG."
  706 #endif
  707 
  708 #if !defined(LE_DUMP)
  709 #  error "Logging are overridden, but LE_DUMP not defined.  Define LE_DUMP."
  710 #endif
  711 
  712 #if !defined(LE_LOG_DUMP)
  713 #  error "Logging are overridden, but LE_LOG_DUMP not defined.  Define LE_LOG_DUMP."
  714 #endif
  715 
  716 #if !defined(LE_INFO)
  717 #  error "Logging are overridden, but LE_INFO not defined.  Define LE_INFO."
  718 #endif
  719 
  720 #if !defined(LE_WARN)
  721 #  error "Logging are overridden, but LE_WARN not defined.  Define LE_WARN."
  722 #endif
  723 
  724 #if !defined(LE_ERROR)
  725 #  error "Logging are overridden, but LE_ERROR not defined.  Define LE_ERROR."
  726 #endif
  727 
  728 #if !defined(LE_CRIT)
  729 #  error "Logging are overridden, but LE_CRIT not defined.  Define LE_CRIT."
  730 #endif
  731 
  732 #if !defined(LE_EMERG)
  733 #  error "Logging are overridden, but LE_EMERG not defined.  Define LE_EMERG."
  734 #endif
  735 
  736 // If SetFilterLevel is not defined when logging is overridden,
  737 // assume it cannot be set programatically
  738 #ifndef le_log_SetFilterLevel
  739 //--------------------------------------------------------------------------------------------------
  740 /**
  741  * Sets the log filter level for the calling component.
  742  *
  743  * @note    Normally not necessary as the log filter level can be controlled at
  744  *          runtime using the log control tool, and can be persistently configured.
  745  *          See @ref c_log_controlling.
  746  *
  747  * @param level   [IN] Log filter level to apply to the current log session.
  748  **/
  749 //--------------------------------------------------------------------------------------------------
  750 #define le_log_SetFilterLevel(level) ((void)(level))
  751 #endif
  752 
  753 
  754 // If le_log_GetFilterLevel is not defined when logging is overridden, assume it
  755 // cannot be obtained programatically.  In this case code should assume filter level
  756 // is equal to static filter level
  757 #ifndef le_log_GetFilterLevel
  758 //--------------------------------------------------------------------------------------------------
  759 /**
  760  * Gets the log filter level for the calling component.
  761  **/
  762 //--------------------------------------------------------------------------------------------------
  763 #define le_log_GetFilterLevel()  (LE_LOG_LEVEL_STATIC_FILTER)
  764 #endif
  765 
  766 //--------------------------------------------------------------------------------------------------
  767 /*
  768  * If logging is overridden, disable Legato tracing mechanism.  Tracing is noisy and should
  769  * not be put into general logs.
  770  */
  771 //--------------------------------------------------------------------------------------------------
  772 
  773 //--------------------------------------------------------------------------------------------------
  774 /**
  775  * Queries whether or not a trace keyword is enabled.
  776  *
  777  * @return
  778  *      true if the keyword is enabled.
  779  *      false otherwise.
  780  */
  781 //--------------------------------------------------------------------------------------------------
  782 #define LE_IS_TRACE_ENABLED(traceRef)  (false)
  783 
  784 
  785 //--------------------------------------------------------------------------------------------------
  786 /**
  787  * Logs the string if the keyword has been enabled by a runtime tool or configuration setting.
  788  */
  789 //--------------------------------------------------------------------------------------------------
  790 #define LE_TRACE(traceRef, string, ...) ((void)(traceRef))
  791 
  792 
  793 //--------------------------------------------------------------------------------------------------
  794 /**
  795  * Gets a reference to a trace keyword's settings.
  796  *
  797  * @param keywordPtr   [IN] Pointer to the keyword string.
  798  *
  799  * @return  Trace reference.
  800  **/
  801 //--------------------------------------------------------------------------------------------------
  802 #define le_log_GetTraceRef(keywordPtr) ((le_log_TraceRef_t)NULL)
  803 
  804 
  805 //--------------------------------------------------------------------------------------------------
  806 /**
  807  * Determines if a trace is currently enabled.
  808  *
  809  * @param traceRef    [IN] Trace reference obtained from le_log_GetTraceRef()
  810  *
  811  * @return  true if enabled, false if not.
  812  **/
  813 //--------------------------------------------------------------------------------------------------
  814 #define le_log_IsTraceEnabled(traceRef) (false)
  815 
  816 
  817 //--------------------------------------------------------------------------------------------------
  818 /**
  819  * Enables a trace.
  820  *
  821  * @note    Normally, this is not necessary, since traces can be enabled at runtime using the
  822  *          log control tool and can be persistently configured.  See @ref c_log_controlling.
  823  *
  824  * @param traceRef    [IN] Trace reference obtained from le_log_GetTraceRef()
  825  *
  826  **/
  827 //--------------------------------------------------------------------------------------------------
  828 #define le_log_EnableTrace(traceRef) ((void)(0))
  829 
  830 
  831 //--------------------------------------------------------------------------------------------------
  832 /**
  833  * Disables a trace.
  834  *
  835  * @note    Normally, this is not necessary, since traces can be enabled at runtime using the
  836  *          log control tool and can be persistently configured.  See @ref c_log_controlling.
  837  *
  838  * @param traceRef    [IN] Trace reference obtained from le_log_GetTraceRef()
  839  *
  840  **/
  841 //--------------------------------------------------------------------------------------------------
  842 #define le_log_DisableTrace(traceRef) ((void)(0))
  843 
  844 #endif /* Logging macro override */
  845 
  846 /// Function that does the real work of translating result codes.  See @ref LE_RESULT_TXT.
  847 const char* _le_log_GetResultCodeString
  848 (
  849     le_result_t resultCode  ///< [in] Result code value to be translated.
  850 );
  851 
  852 /// Function that does the real work of translating result codes.  See @ref LE_RESULT_TXT.
  853 const char* _le_log_GetErrnoCodeString
  854 (
  855     int errnoCode  ///< [in] errno value to be translated.
  856 );
  857 
  858 /// Function that exits in a race-free manner -- work around glibc BZ#14333
  859 __attribute__((noreturn))
  860 void _le_log_ExitFatal
  861 (
  862     void
  863 );
  864 
  865 //--------------------------------------------------------------------------------------------------
  866 /** @internal
  867  * The following macros are used to send log messages at different severity levels conditionally.
  868  * If the condition is true the message is logged.  If the condition is false the message is not
  869  * logged.
  870  *
  871  * Accepts printf-style arguments, consisting of a format string followed by zero or more parameters
  872  * to be printed (depending on the contents of the format string).
  873  */
  874 //--------------------------------------------------------------------------------------------------
  875 
  876 /** @ref LE_DEBUG if condition is met. */
  877 #define LE_DEBUG_IF(condition, formatString, ...) \
  878         if (condition) { LE_DEBUG(formatString, ##__VA_ARGS__); }
  879 /** @ref LE_INFO if condition is met. */
  880 #define LE_INFO_IF(condition, formatString, ...) \
  881         if (condition) { LE_INFO(formatString, ##__VA_ARGS__); }
  882 /** @ref LE_WARN if condition is met. */
  883 #define LE_WARN_IF(condition, formatString, ...) \
  884         if (condition) { LE_WARN(formatString, ##__VA_ARGS__); }
  885 /** @ref LE_ERROR if condition is met. */
  886 #define LE_ERROR_IF(condition, formatString, ...) \
  887         if (condition) { LE_ERROR(formatString, ##__VA_ARGS__); }
  888 /** @ref LE_CRIT if condition is met. */
  889 #define LE_CRIT_IF(condition, formatString, ...) \
  890         if (condition) { LE_CRIT(formatString, ##__VA_ARGS__); }
  891 /** @ref LE_EMERG if condition is met. */
  892 #define LE_EMERG_IF(condition, formatString, ...) \
  893         if (condition) { LE_EMERG(formatString, ##__VA_ARGS__); }
  894 
  895 
  896 //--------------------------------------------------------------------------------------------------
  897 /**
  898  * Log fatal errors by killing the calling process after logging the message at EMERGENCY
  899  * level.  This macro never returns.
  900  *
  901  * Accepts printf-style arguments, consisting of a format string followed by zero or more parameters
  902  * to be printed (depending on the contents of the format string).
  903  */
  904 //--------------------------------------------------------------------------------------------------
  905 #ifndef LE_FATAL
  906 #   if !LE_CONFIG_DEBUG
  907 #       define LE_FATAL(formatString, ...) \
  908         { LE_EMERG(formatString, ##__VA_ARGS__); _le_log_ExitFatal(); }
  909 #   else
  910 #       define LE_FATAL(formatString, ...) \
  911         { LE_EMERG(formatString, ##__VA_ARGS__); abort(); }
  912 #   endif
  913 #endif
  914 
  915 
  916 //--------------------------------------------------------------------------------------------------
  917 /**
  918  * This macro does nothing if the condition is false, otherwise it logs the message at EMERGENCY
  919  * level and then kills the calling process.
  920  *
  921  * Accepts printf-style arguments, consisting of a format string followed by zero or more parameters
  922  * to be printed (depending on the contents of the format string).
  923  */
  924 //--------------------------------------------------------------------------------------------------
  925 #define LE_FATAL_IF(condition, formatString, ...) \
  926         if (condition) { LE_FATAL(formatString, ##__VA_ARGS__) }
  927 
  928 
  929 //--------------------------------------------------------------------------------------------------
  930 /**
  931  * This macro does nothing if the condition is true, otherwise it logs the condition expression as
  932  * a message at EMERGENCY level and then kills the calling process.
  933  */
  934 //--------------------------------------------------------------------------------------------------
  935 #define LE_ASSERT(condition)                            \
  936     LE_FATAL_IF(!(condition), "Assert Failed: '%s'", #condition)
  937 
  938 
  939 //--------------------------------------------------------------------------------------------------
  940 /**
  941  * This macro does nothing if the condition is LE_OK (0), otherwise it logs that the expression did
  942  * not evaluate to LE_OK (0) in a message at EMERGENCY level and then kills the calling process.
  943  */
  944 //--------------------------------------------------------------------------------------------------
  945 #define LE_ASSERT_OK(condition)                                         \
  946     LE_FATAL_IF((condition) != LE_OK, "Assert Failed: '%s' is not LE_OK (0)", #condition)
  947 
  948 
  949 //--------------------------------------------------------------------------------------------------
  950 /**
  951  * Get a null-terminated, printable string representing an le_result_t value.
  952  *
  953  * For example, LE_RESULT_TXT(LE_NOT_PERMITTED) would return a pointer to a string containing
  954  * "LE_NOT_PERMITTED".
  955  *
  956  * "(unknown)" will be returned if the value given is out of range.
  957  *
  958  * @return Pointer to a string constant.
  959  */
  960 //--------------------------------------------------------------------------------------------------
  961 #define LE_RESULT_TXT(v) _le_log_GetResultCodeString(v)
  962 
  963 //--------------------------------------------------------------------------------------------------
  964 /**
  965  * Get a null-terminated, printable string representing an errno value.
  966  *
  967  * Use this instead of strerror() or strerror_r() since those have
  968  * incompatible implementations on different platforms.
  969  *
  970  * @return Pointer to a string constant.
  971  */
  972 //--------------------------------------------------------------------------------------------------
  973 #ifndef LE_ERRNO_TXT
  974 #  define LE_ERRNO_TXT(v) _le_log_GetErrnoCodeString(v)
  975 #  define LE_LOG_NEED_GET_ERRNO_STRING 1
  976 
  977 const char *_le_log_GetErrnoCodeString(int error);
  978 #endif
  979 
  980 
  981 //--------------------------------------------------------------------------------------------------
  982 /**
  983  * Connects to the Log Control Daemon.  This must not be done until after the Messaging system
  984  * is initialized, but must be done before the main thread's Event Loop starts to ensure that
  985  * all log settings are received from the Log Control Daemon and applied to sessions in the local
  986  * process before any component initialization functions are run.
  987  */
  988 //--------------------------------------------------------------------------------------------------
  989 LE_FULL_API void le_log_ConnectToControlDaemon
  990 (
  991     void
  992 );
  993 
  994 //--------------------------------------------------------------------------------------------------
  995 /**
  996  * Registers a named component with the logging system.
  997  *
  998  * @return
  999  *      A log session reference.  This reference must be kept by the component and accessible
 1000  *      through a local macro with the name LE_LOG_SESSION.
 1001  */
 1002 //--------------------------------------------------------------------------------------------------
 1003 LE_FULL_API le_log_SessionRef_t le_log_RegComponent
 1004 (
 1005     const char       *componentNamePtr, ///< [IN] A pointer to the component's name.
 1006     le_log_Level_t  **levelFilterPtrPtr ///< [OUT] Set to point to the component's level filter.
 1007 );
 1008 
 1009 #endif // LEGATO_LOG_INCLUDE_GUARD
le_log_RegComponent
LE_FULL_API le_log_SessionRef_t le_log_RegComponent(const char *componentNamePtr, le_log_Level_t **levelFilterPtrPtr)
LE_SHARED
#define LE_SHARED
Definition: le_basics.h:297
le_result_t
le_result_t
Definition: le_basics.h:45
LE_LOG_WARN
Warning. Possibly indicates a problem. Should be addressed. 
Definition: le_log.h:378
le_log_Level_t
le_log_Level_t
Definition: le_log.h:374
LE_LOG_DEBUG
Debug message. 
Definition: le_log.h:376
LE_LOG_ERR
Definition: le_log.h:379
_le_log_GetErrnoCodeString
const char * _le_log_GetErrnoCodeString(int errnoCode)
Function that does the real work of translating result codes. See LE_RESULT_TXT. 
_le_log_GetResultCodeString
const char * _le_log_GetResultCodeString(le_result_t resultCode)
Function that does the real work of translating result codes. See LE_RESULT_TXT. 
le_log_ConnectToControlDaemon
LE_FULL_API void le_log_ConnectToControlDaemon(void)
LE_LOG_CRIT
Definition: le_log.h:381
LE_FULL_API
#define LE_FULL_API
Definition: le_apiFeatures.h:40
LE_LOG_INFO
Informational message. Normally expected. 
Definition: le_log.h:377
LE_LOG_EMERG
Emergency. A fatal error has occurred. A process is being terminated. 
Definition: le_log.h:383
_le_log_ExitFatal
void _le_log_ExitFatal(void)
Function that exits in a race-free manner -- work around glibc BZ#14333. 
LE_LOG_MAX
One beyond maximum log level. 
Definition: le_log.h:384