RM 11 4 1 19 Exception Information (GNAT Reference Manual)

### 6.14 RM 11.4.1(19): Exception Information ¶

> “`Exception_Message` by default and `Exception_Information` should produce information useful for debugging. `Exception_Message` should be short, about one line. `Exception_Information` can be long. `Exception_Message` should not include the `Exception_Name`. `Exception_Information` should include both the `Exception_Name` and the `Exception_Message`.”

Followed. For each exception that doesn’t have a specified `Exception_Message`, the compiler generates one containing the location of the raise statement. This location has the form ‘file_name:line’, where file_name is the short file name (without path information) and line is the line number in the file. Note that in the case of the Zero Cost Exception mechanism, these messages become redundant with the Exception_Information that contains a full backtrace of the calling sequence, so they are disabled. To disable explicitly the generation of the source location message, use the Pragma `Discard_Names`.