from tests/aslts/README:

   ACPICA ASL grammar validation Test Suite (ASLTS)


   ASLTS verifies, in "hardware-independent" mode, conformity of ACPICA
ASL compiler and interpreter to the ACPI ASL grammar specification. The
more common task of ASLTS is to check, in "hardware-independent" mode also,
all the functionality of ACPICA which can be initiated and then verified
from inside the test modules coded in ASL. The first local task is performed
by the test collection named 'functional', to achieve the second one the tests
of other collections are intended: complex, exceptions, etc. The conditional
difference between the tests of 'functional' and 'complex' collections is that
the tests of 'functional' collection checks specific functionality of the
particular ASL operator while the tests of 'complex' collection verify the
more common functionality.

   The testing is performed in "hardware-independent" mode without any
access to ACPI subsystem hardware. In this purpose the AcpiExec utility
is used which includes the entire ACPICA subsystem and allows to execute
the AML code and thus verify functionality of ACPICA subsystem.

   The ASL source code is compiled to AML code and then passed to
AcpiExec utility. In this relation one more type tests are provided,
so called ASL-compilation control test collection, which check ability
of ASL compiler to reveal and report incorrect ASL code.

   The tests of the exceptional conditions test collection
initiate and verify exceptional conditions, check that the
exceptions occur (or not occur) in the expected specified way.

   The testing is provided in both 32-bit and 64-bit modes
(option -r of ASL compiler) as well both normal and slack
modes (option -s of AcpiExec).