====== Error Handling ======

In CP2K there exist three convenient macros for error handling. They are defined in [[src>src/base/base_uses.f90]], and are therefore always available. However, these macros can only be used for **short messages** (approximately less than 7 words), because of Fortran's line length limitation.
<code Fortran>
   CPWARN("A short warning message")
   CPABORT("A short error message")
   CPASSERT(2>1) ! For sanity checks only, not for user errors.
</code>

For longer messages one can use these two routines:
<code Fortran>
   CALL cp_warn(__LOCATION__,"A long warning message "//&
                "which can span multiple lines and contains "//&
                "some valuable advice for the user.")

   CALL cp_abort(__LOCATION__,"A long error message "//&
                 "with even more valuable advices.")      
</code>

<note important>
Messages from ''CPWARN'' and ''cp_warn'' are only printed on the first MPI-rank.\\ Warnings issued on other ranks are ignored.
</note>

===== Cheat Sheet =====
If you want to...
  * print a **short warning** message, then you should use:<code Fortran> CPWARN("your short message")</code>
  * print a **longer warning** message, then you should use:<code Fortran> CALL cp_warn(__LOCATION__,"your lengthy message, "//&
              "which can even span multiple lines")</code>

  * **stop** the program with a **short** error message, then you should use:<code Fortran> CPABORT("your short message")</code>
  * **stop** the program with a **longer** error message, then you should use:<code Fortran> CALL cp_abort(__LOCATION__,"your lengthy message, "//&
               "which can even span multiple lines")</code>
  * have a **simple assertion** without a custom error message, then you should use:<code Fortran> CPASSERT(your_logical_expression)</code>
  * have a **simple assertion** with a **short** error message, then you should use:<code Fortran> IF(.NOT.your_logical_expression) CPABORT("your short message")</code>
  * have a **complex assertion** with a **short** error message, then you should use:<code Fortran> IF(.NOT.your_super_complicated_logical_expression_that_takes_alot_of_space)&
    CPABORT("your short message")</code>
  * have a **lengthy assertion** with a **longer** error message, then you should use:<code Fortran> IF(.NOT.your_super_long_logical_expression_that_takes_alot_of_space)&
    CALL cp_abort(__LOCATION__,"your lengthy message"//&
                  "which again can even span multiple lines")</code>