For -xprofile=tcov

By default the profile bucket is called <argv[0]>.profile in the current directory.

If you set SUN_PROFDATA, the profile bucket is called $SUN_PROFDATA, wherever it is located.

If you set SUN_PROFDATA_DIR, the profile bucket is placed in the specified directory.

SUN_PROFDATA and SUN_PROFDATA_DIR are independent. If both are specified, the profile bucket name is generated by using SUN_PROFDATA_DIR to find the profile bucket and, SUN_PROFDATA is used to name the profile bucket in that directory.

A UNIX process can change its current working directory during the execution of a program. The current working directory used to generate the profile bucket is the current working directory of the program at exit. In the rare case where a program actually does change its current working directory during execution, you can use the environment variables to control where the profile bucket is generated.