Logging

WOLF uses the spdlog library for logging. On top of it, we have implemented a custom logger macros that allow us to log messages with different levels of severity:

WOLF_TRACE(...): Displayed (in white) unless compiled with -D_WOLF_TRACE=FALSE
WOLF_DEBUG(...): Only displayed (in cyan) if compiled in debug mode.
WOLF_INFO(...): Displayed in green.
WOLF_WARN(...): Displayed in yellow.
WOLF_ERROR(...): Displayed in red.

All logging macros accept several inputs of type string and other types with defined stream (int, floats, Eigen objects, YAML::Nodes, etc.) At the begining of the message, the logger will print:

[severity][file_name Lline_number] function_name: message

The following code:

WOLF_TRACE("test trace ", 5, " ", 0.123);
WOLF_DEBUG("test debug ", 5, " ", 0.123);
WOLF_INFO("test info ", 5, " ", 0.123);
WOLF_WARN("test warn ", 5, " ", 0.123);
WOLF_ERROR("test error ", 5, " ", 0.123);

compiled in debug mode without disabling trace will output:

[trace][gtest_logging.cpp L45] TestBody: test trace 5 0.123
[debug][gtest_logging.cpp L52] TestBody: test debug 5 0.123
[info][gtest_logging.cpp L24] TestBody: test info 5 0.123
[warning][gtest_logging.cpp L31] TestBody: test warn 5 0.123
[error][gtest_logging.cpp L38] TestBody: test error 5 0.123

Conditional macros

For all levels, we also defined the conditional macros WOLF_xxxx_COND(condition, ...) that only log the message if the condition is evaluated to true. We recommend to use them, specially for debug and trace.

Warning

The WOLF_TRACE and WOLF_DEBUG macros may expand to nothing depending on the compiling options. For example, note that the following code:

if (some_condition)
    WOLF_DEBUG("Some message here", some_variable, "and more text");

next_instruction;

in case of compiling in release mode, will expand to an undesired implementation:

if (some_condition)
    next_instruction;

Always wrap logging macros in braces {} or use the conditional logging macros WOLF_DEBUG_COND and WOLF_TRACE_COND, to prevent these compilation issues.

The following code:

WOLF_TRACE_COND(true, "This message should appear!");
WOLF_TRACE_COND(false, "This message should NOT appear!");

WOLF_DEBUG_COND(true, "This message should appear!");
WOLF_DEBUG_COND(false, "This message should NOT appear!");

WOLF_INFO_COND(true, "This message should appear!");
WOLF_INFO_COND(false, "This message should NOT appear!");

WOLF_WARN_COND(true, "This message should appear!");
WOLF_WARN_COND(false, "This message should NOT appear!");

WOLF_ERROR_COND(true, "This message should appear!");
WOLF_ERROR_COND(false, "This message should NOT appear!");

compiled in debug mode and without disabling trace will output:

[trace][gtest_logging.cpp L46] TestBody: This message should appear!
[debug][gtest_logging.cpp L53] TestBody: This message should appear!
[info][gtest_logging.cpp L25] TestBody: This message should appear!
[warning][gtest_logging.cpp L32] TestBody: This message should appear!
[error][gtest_logging.cpp L39] TestBody: This message should appear!

Macros for processors

There is an implementation of WOLF_DEBUG to be used in processors code. Instead of enabling/disabling according to the build type, WOLF_PROC_DEBUG can be enabled and disabled by the user via YAML. Each processor has the parameter debug_verbose_level to control which WOLF_PROC_DEBUG are displayed to the console:

If compiled in debug mode, all messages are displayed.
If compiled in release mode, logging depends on the value of debug_verbose_level:
- none: No messages are displayed.
- derived: only the WOLF_PROC_DEBUG(...) placed in the derived processor are displayed.
- base: only the WOLF_PROC_DEBUG(...) placed in the base processor classes are displayed.
- all: All messages are displayed.

Analogously to the other macros, there is the WOLF_PROC_DEBUG_COND(condition, ...).

Note

This implementation requires Boost >= 1.73. If not found or earlier version, derived and base will behave like all.