Jafar debug tools

Overview

Module kernel defines a debug stream in class jafar::debug::DebugStream. The use of a singleton class ensures that a single instance of this stream is created. A debug message has two characteristics:

• the name of the module which sends the message,
• the debug level of the message.

Sending a message to the debug stream

To send a message to the debug stream, one has to use the macros JFR_WARNING, JFR_DEBUG, JFR_VDEBUG, JFR_VVDEBUG defined in jafarMacro.hpp. Each macro sends a message with the corresponding level, the name of the current module is automatically added.

#include "kernel/jafarDebug.hpp"

int i = 2;
JFR_DEBUG("The value of i is " << i); 
 
output:
  D:pipo/test.cpp:55: The value of i is 2

Sending message from tcl

Module kernel defines kernel::putsDbg to send a message to the debug stream from the interactive shell. The message is sent with module value shell and with default level DebugStream::Debug.

jafar% set i 12
12
jafar% kernel::putsDbg "i=$i"
D:shell: i=12
jafar% kernel::putsDbg "i=$i" $::kernel::DebugStream_VeryVerboseDebug
jafar%

Here the debug level for pseudo module shell is DebugStream::Debug

Controlling the debug output

Controlling at compile time

At compile time, debug messages are disabled with the flag JFR_NDEBUG (Customize the compilation process: Jafar specific flags).

Usually, warning messages are also sent to the debug stream. When the flag JFR_NDEBUG is defined, warning messages are still active and sent to the std::cerr stream. To disable all outputs, you can define the flag JFR_QUIET (Customize the compilation process: Jafar specific flags).

Controlling at runtime

Based on the debugging level and the name of the sending module, debugging messages can be enabled or disabled. When a message is disabled, c++ stream mechanism allows the operation to be very low cost. Moreover, the stream can be sent to a file. The debug stream is configured via static methods of the jafar::debug::DebugStream class. These methods are wrapped by swig and can therefore be used from the interactive shell.