Custom testsuite drivers are declared by defining the make variables
LOG_DRIVER or ext_LOG_DRIVER (where ext must
be declared in TEST_EXTENSIONS). They must be defined to
programs or scripts that will be used to drive the execution, logging,
and outcome report of the tests with corresponding extensions (or of
those with no registered extension in the case of LOG_DRIVER).
Clearly, multiple distinct test drivers can be declared in the same
Makefile.am. Note moreover that the LOG_DRIVER variables
are not a substitute for the LOG_COMPILER variables: the
two sets of variables can, and often do, usefully and legitimately
coexist.
The developer-reserved variable AM_LOG_DRIVER_FLAGS and the
user-reserved variable LOG_DRIVER_FLAGS can be used to define
flags that will be passed to each invocation of LOG_DRIVER,
with the user-defined flags obviously taking precedence over the
developer-reserved ones. Similarly, for each extension ext
declared in TEST_EXTENSIONS, flags listed in
AM_ext_LOG_DRIVER_FLAGS and
ext_LOG_DRIVER_FLAGS will be passed to
invocations of ext_LOG_DRIVER.