There are two suites of tests in this directory: run-tests and gtests.
The run-tests are identified by directories named with with a numeric prefix and containing an info.txt file. For most run tests, the sources are in the "src" subdirectory. Sources found in the "src2" directory are compiled separately but to the same output directory; this can be used to exercise "API mismatch" situations by replacing class files created in the first pass. The "src-ex" directory is built separately, and is intended for exercising class loaders.
The gtests are in named directories and contain a .java source file.
All tests in either suite can be run using the "art/test.py" script. Additionally, run-tests can be run individidually. All of the tests can be run on the build host, on a USB-attached device, or using the build host "reference implementation".
To see command flags run:
$ art/test.py -h
$ art/test.py --host
$ art/test.py --target
$ art/test.py --host -g
$ art/test.py --target -g
$ art/test.py --host -r
$ art/test.py --target -r
$ art/test.py --host -r -t 001-HelloWorld
$ art/test.py --target -r -t 001-HelloWorld