DragonFly On-Line Manual Pages
KYUA-DEBUG(1) DragonFly General Commands Manual KYUA-DEBUG(1)
NAME
kyua debug - Executes a single test case with facilities for debugging
SYNOPSIS
kyua debug [--build-root path] [--kyuafile file] [--stdout path]
[--stderr path] test_case
DESCRIPTION
The kyua debug command provides a mechanism to execute a single test case
bypassing some of the Kyua infrastructure and allowing the user to poke
into the execution behavior of the test.
The test case to run is selected by providing a test filter, described
below in Test filters, that matches a single test case. The test case is
executed and its result is printed as the last line of the output of the
tool.
The test executed by kyua debug is run under a controlled environment as
described in Test isolation.
At the moment, the kyua debug command allows the following aspects of a
test case execution to be tweaked:
* Redirection of the test case's stdout and stderr to the console (the
default) or to arbitraty files. See the --stdout and --stderr
options below.
The following subcommand options are recognized:
--build-root path
Specifies the build root in which to find the test programs
referenced by the Kyuafile, if different from the Kyuafile's
directory. See Build directories below for more information.
--kyuafile file, -k file
Specifies the Kyuafile to process. Defaults to Kyuafile file in the
current directory.
--stderr path
Specifies the file to which to send the standard error of the test
program's body. The default is /dev/stderr, which is a special that
redirects the output to the console.
--stdout path
Specifies the file to which to send the standard output of the test
program's body. The default is /dev/stdout, which is a special that
redirects the output to the console.
For example, consider the following Kyua session:
$ kyua test
kernel/fs:mkdir -> passed
kernel/fs:rmdir -> failed: Invalid argument
1/2 passed (1 failed)
At this point, we do not have a lot of information regarding the failure
of the `kernel/fs:rmdir' test. We can run this test through the kyua
debug command to inspect its output a bit closer, hoping that the test
case is kind enough to log its progress:
$ kyua debug kernel/fs:rmdir
Trying rmdir('foo')
Trying rmdir(NULL)
kernel/fs:rmdir -> failed: Invalid argument
Luckily, the offending test case was printing status lines as it
progressed, so we could see the last attempted call and we can know match
the failure message to the problem.
Build directories
Build directories (or object directories, target directories, product
directories, etc.) is the concept that allows a developer to keep the
source tree clean from build products by asking the build system to place
such build products under a separate subtree.
Most build systems today support build directories. For example, the GNU
Automake/Autoconf build system exposes such concept when invoked as
follows:
$ cd my-project-1.0
$ mkdir build
$ cd build
$ ../configure
$ make
Under such invocation, all the results of the build are left in the
my-project-1.0/build/ subdirectory while maintaining the contents of
my-project-1.0/ intact.
Because build directories are an integral part of most build systems, and
because they are a tool that developers use frequently, kyua debug
supports build directories too. This manifests in the form of kyua debug
being able to run tests from build directories while reading the (often
immutable) test suite definition from the source tree.
One important property of build directories is that they follow (or need
to follow) the exact same layout as the source tree. For example,
consider the following directory listings:
src/Kyuafile
src/bin/ls/
src/bin/ls/Kyuafile
src/bin/ls/ls.c
src/bin/ls/ls_test.c
src/sbin/su/
src/sbin/su/Kyuafile
src/sbin/su/su.c
src/sbin/su/su_test.c
obj/bin/ls/
obj/bin/ls/ls*
obj/bin/ls/ls_test*
obj/sbin/su/
obj/sbin/su/su*
obj/sbin/su/su_test*
Note how the directory layout within src/ matches that of obj/. The src/
directory contains only source files and the definition of the test suite
(the Kyuafiles), while the obj/ directory contains only the binaries
generated during a build.
All commands that deal with the workspace support the --build-root path
option. When this option is provided, the directory specified by the
option is considered to be the root of the build directory. For example,
considering our previous fake tree layout, we could invoke kyua debug as
any of the following:
$ kyua debug --kyuafile=src/Kyuafile --build-root=obj
$ cd src && kyua debug --build-root=../obj
Test filters
A test filter is a string that is used to match test cases or test
programs in a test suite. Filters have the following form:
test_program_name[:test_case_name]
Where `test_program_name' is the name of a test program or a subdirectory
in the test suite, and `test_case_name' is the name of a test case.
Test isolation
The test programs and test cases run by kyua debug are all executed in a
deterministic environment. This known, clean environment serves to make
the test execution as reproducible as possible and also to prevent
clashes between tests that may, for example, create auxiliary files with
overlapping names.
For plain test programs and for TAP test programs, the whole test program
is run under a single instance of the environment described in this page.
For ATF test programs (see atf(7)), each individual test case and test
cleanup routine are executed in separate environments.
Process space
Each test is executed in an independent processes. Corollary: the
test can do whatever it wants to the current process (such as modify
global variables) without having to undo such changes.
Session and process group
The test is executed in its own session and its own process group.
There is no controlling terminal attached to the session.
Should the test spawn any children, the children should maintain the
same session and process group. Modifying any of these settings
prevents kyua debug from being able to kill any stray subprocess as
part of the cleanup phase. If modifying these settings is necessary,
or if any subprocess started by the test decides to use a different
process group or session, it is the responsibility of the test to
ensure those subprocesses are forcibly terminated during cleanup.
Work directory
The test is executed in a temporary directory automatically created
by the runtime engine. Corollary: the test can write to its current
directory without needing to clean any files and/or directories it
creates. The runtime engine takes care to recursively delete the
temporary directories after the execution of a test case. Any file
systems mounted within the temporary directory are also unmounted.
Home directory
The HOME environment variable is set to the absolute path of the work
directory.
Umask
The value of the umask is set to 0022.
Environment
The LANG, LC_ALL, LC_COLLATE, LC_CTYPE, LC_MESSAGES, LC_MONETARY,
LC_NUMERIC and LC_TIME variables are unset.
The TZ variable is set to `UTC'.
The TMPDIR variable is set to the absolute path of the work
directory. This is to prevent the test from mistakenly using a
temporary directory outside of the automatically-managed work
directory, should the test use the mktemp(3) familiy of functions.
Process limits
The maximum soft core size limit is raised to its corresponding hard
limit. This is a simple, best-effort attempt at allowing tests to
dump core for further diagnostic purposes.
Configuration varibles
The test engine may pass run-time configuration variables to the test
program via the environment. The name of the configuration variable
is prefixed with `TEST_ENV_' so that a configuration variable of the
form `foo=bar' becomes accessible in the environment as
`TEST_ENV_foo=bar'.
EXIT STATUS
The kyua debug command returns 0 if the test case passes or 1 if the test
case fails.
Additional exit codes may be returned as described in kyua(1).
SEE ALSO
kyua(1), kyuafile(5)
DragonFly 6.5-DEVELOPMENT October 13, 2014 DragonFly 6.5-DEVELOPMENT