Automatic regression tests: --------------------------- The Valgrind gdbserver automatic tests are by default executed as part of the Valgrind test suite: make regtest By default, these tests are running with the gdb found at Valgrind configure time. If you want to test with another gdb version, you can do: make regtest GDB=/path/to/another/gdb or (to just run the gdbserver tests with another gdb): cd gdbserver_tests make check cd .. gdbserver_tests/make_local_links /path/to/another/gdb perl tests/vg_regtest gdbserver_tests The minimum version to run the tests is gdb >= 6.5. Previous versions do not have the 'target remote |' command. It would be possible to use an older version by using the option --port of vgdb, and using the tcp/ip variant of the 'target remote' GDB command. The tests have been run on various platforms using gdb versions >= 7.2 and on some platforms gdb 7.0 and 7.1. Some gdb tests implies a gdb >= 7.2. (these are automatically disabled if testing with a lower version). Test behaviour with gdb < 7.0 is unknown: some might fail, some might block or loop for a very long time. Some tests implies to have a vgdb "ptrace invoker" capable. The prerequisite are established during make regtest (using marker files). Each test verifies the prerequisite using the prereq: line. In case of failing tests ------------------------ When executed with a new gdb version and/or depending on the OS version, gdbserver tests might often fail due to (irrelevant) differences. Such irrelevant differences have to be filtered by gdbserver_tests/filter_gdb. You are welcome to fix such bugs by enhancing filter_gdb. Alternatively, to report such problems, the best is to re-run the gdbserver tests the following way: perl tests/vg_regtest --keep-unfiltered gdbserver_tests Then file a bug in bugzilla, giving the following information: output of gdbserver_tests/gdb --version uname -a cat /etc/issue valgrind --version (and/or svn version) and attach a tar file containing all the *.out and *.diff files in gdbserver_tests directory If a gdbserver test fails for other reasons, you can run the test manually in two windows: In one window, the valgrind In another window, you launch gdb yourself, and you copy paste the command from xxxx.stdinB.gdb. This might help to see what is wrong. Another good trick is also to execute the same kind of actions using a gdb connected to the gdbserver part of gdb. You can examine what is happening by enabling the trace of the packets being sent using the gdb command: set debug remote 1 Note however that the packets might be different (e.g. the Valgrind gdbserver understands the 'P' packet, which might not be understood by the gdbserver of gdb). Naming conventions: ------------------- The gdbserver tests are done with various Valgrind tools. A gdbserver test using a tool xxxxxx should have its name starting with the 'short two letters code' of this tool. For example, the test mcvabits.vgtest is using Memcheck tool, while the test mssnapshot.vgtest is using massif tool. Typically, a gdbserver test implies to launch two programs: prog: a program running under valgrind progB: another program (typically, either gdb or vgdb standalone) The conventions about how to specify the 2nd program in a .vgtest are explained in the file ../tests/vg_regtest.in Many tests are using gdb as progB. The input for gdb is named xxxxxx.stdinB.gdb. One day, we might imagine to run tests in parallel. So, each test gets its own '--vgdb-prefix' argument. This also help to avoid interactions between two successive tests: if a previous test stayed blocked, the vgdb of the next test will not report an error due to multiple possible FIFOs. Rational for test approach -------------------------- Two approaches have been looked at: V: use the 'vg_regtest' approach used by the rest of Valgrind tests G: use the gdb Dejagnu test framework. Advantages of V: much simpler that G, known by Valgrind developers, no additional dependency for the Valgrind build and test. Disadvantages of V: not well suited to testing of interactive tools, very unflexible way to test the results (everything is in "template" files), templates contains often irrelevant data for the test but it can make the test fail. After writing 13 tests, it looks like the template diff approach is quite fragile (e.g. changing the gdb version and/or the OS version influences the output of irrelevant things which are part of the template). A more flexible template filtering is needed. Maybe something like: The program under test is outputting its instructions to be filtered in special markers e.g. #pushf filter_addresses | filter_messages ... some output #pushf an_additional_filter ... some other output, filtered by both the first and second push #popf ... here output filtered only by the first pushf #popf Advantages of G: much more powerful, well suited to test a gdb with a gdbserver, tests can verify specifically some output without being impacted by other output, allow to test Valgrind gdbserver with the all of the gdb test suite (but a lot of tests will rather test gdb than Valgrind gdbserver). Disadvantages: not an easy beast to understand and master, running the whole gdb testsuite with Valgrind gdbserver looks to be a challenge. Currently, tests are written with vg_regtest. Approach G will be looked at it again (e.g. to complement V) once a basic set of tests are available. Manual tests still to automate: ------------------------------- Validate monitor commands abbreviation recognition *************************************************** mo v.info all_errors # to show all errors recorded so far mo v.i a # the same mo v # must give an error: v can match v.set v.info mo v # the same v mo v. # the same v. test of gdb detaching or dying ****************************** valgrind --vgdb=yes --vgdb-error=0 --vgdb-poll=500 ./t in another window gdb ./t set remotetimeout 100 target remote|vgdb detach valgrind continues target remote|vgdb reattach detach valgrind continues target remote|vgdb reattach monitor v.wait no effect test of valgrind/gdb output redirection *************************************** valgrind --vgdb=yes --vgdb-error=1 --vgdb-poll=500 ./t in another window **** command to type*** ****** expected behaviour gdb ./t set remotetimeout 1000 target remote | vgdb mo v.set vgdb-error 1000 # so that valgrind does stop only at error 1000 and after mo v.set gdb_output # to have further valgrind errors output in gdb c # continue, some errors will appear C-c # interrupt program mo v.set log_output # to set back the valgrind output to normal process log output mo l # leak output to appear in log of process mo v.set mixed_output mo l # leak output to appear in gdb test with a big executable: firefox *********************************** valgrind --vgdb=yes --vgdb-error=1000 --vgdb-poll=50000 --trace-children=yes firefox 2>&1 | tee f.out wait for some messages from the "big" firefox executable to appear. Then: gdb /usr/lib/firefox-3.5/firefox target remote | vgdb ... then you can do various next/print/bt/bt full/break/... to see it is working bulk test with the above ************************ to verify there is no race condition/no reentrance problem between gdbserver code and valgrind: start firefox like in the previous test. In another window, do: while true do vgdb leak sleep 1 done NB: this will make firefox run extremely slow, as it will do a leak search every second. Test of "jump" functionality ---------------------------- ... to be done : put two breaks, jump over one. ... same but when error is encountered * test with --max-invoke-ms=0 ----------------------------- valgrind --vgdb=yes ./t ... wait till you see "petachounok sleeping 4 of 15 then try to gdb it !!!! this often causes gdb to report a protocol timeout. use gdb set remotetimeout to avoid that. The symptoms of a timeout are: (gdb) tar rem|vgdb --max-invoke-ms=0 Remote debugging using |vgdb --max-invoke-ms=0 relaying data between gdb and process 2930 Ignoring packet error, continuing... warning: unrecognized item "timeout" in "qSupported" response * tests of shadow registers ---------------------------- Show/modify shadow registers