738e5c3f28
Sorry for the late email regarding the gcov code coverage information for udev. For those of you who have not yet noticed, udev can now be compiled with gcov support and provide code coverage analysis. All pertinent scripts and information can be found in the udev tree. Please refer to "README-gcov_for_udev" for detailed information on compiling gcov into udev and obtaining code coverage analysis. I've enclosed a patch that updates the README-gcov_for_udev. Also, "udev-test.pl" in udev/test/ was expanded to test symlinks, permissions, and some lack of node creation a little more thoroughly. All comments and feedback would be greatly welcomed. Also, any extra testing would be appreciated. Thanks,
109 lines
4 KiB
Plaintext
109 lines
4 KiB
Plaintext
################################################
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Using GCC's code coverage tool, gcov, with udev
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################################################
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For more information on using gcov please see:
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http://gcc.gnu.org/onlinedocs/gcc/Gcov.html
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With that said, here is how to get code coverage analysis for udev files.
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Note that this was developed with udev version 024.
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- Make sure you've installed udev and that it is working properly.
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If you are having problems, refer to the README and HOWTO-udev_for_dev
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documents in udev tarball. I've also compiled a udev_for_dev
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toubleshooting document for Red Hat which can be found in:
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docs/rh_udev_for_dev.txt
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- execute make_gcov.sh from udev top level directory
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./make_gcov.sh
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This will compile udev with gcov support. Basically make_gcov.sh will
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run make but override the CFLAGS. It strips any optimization from
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CFLAGS in order for gcov to get correct code coverage analysis. It will
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also add the -fprofile-arcs and -ftest-coverage options which are the
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necessary flags needed to use gcov.
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make_gcov.sh will assume the same default parameters as the regular
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make but also accepts the same parameters. For example if you want
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to get code coverage analysis for udev with the DEBUG flag turned
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on, you would just execute:
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./make_gcov.sh DEBUG=true
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There is one exception, gcov will not work with klibc as it does not
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compile cleanly with the -fprofile-arcs and -ftest-coverage flags.
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With this said it is pretty much useless to set the KERNEL_DIR flag
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when using make_gcov.sh as well.
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Don't be alarmed if you look into your udev directory and see that it
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has been polluted with a bunch of *.bb, *.bbg, *.da, and *.gcov files.
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gcov creates and uses these files to extract the code coverage info.
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- After running make_gcov.sh you need to install udev again. So basically,
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su to root
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make install
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- Then execute some udev tasks. You can run some udev tests, reboot, or
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do anything your little udev heart desires. Once you are satisfied, you
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can now see how much udev code was covered. I personally recommend just
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running test/udev-test.pl for starters.
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- To get the udev code coverage analysis, execute run_gcov.sh from udev top
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level directory. You need to be root to do this.
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su to root
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./run_gcov.sh
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- This creates udev_gcov.txt in the udev top level directory which holds all
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the code coverage information. To see an example of the code coverage info
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after executing the udev-test.pl test, please see:
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http://developer.osdl.org/ogasawara/gcov_for_udev/udev_gcov.txt
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- Also, after having executed gcov on udev (ie executing run_gcov.sh) a
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*.gcov file is created for every file which contained code that was
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used. Looking at the *.gcov files, one will see what lines of code
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were hit, and what lines were missed. For, example if code in udev-add.c
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were executed, gcov then created a file called udev-add.c.gcov. And a
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portion of udev-add.c.gov might look like:
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static int get_major_minor(struct sysfs_class_device *class_dev, struct udevice *udev)
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95 {
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95 struct sysfs_attribute *attr = NULL;
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95 attr = sysfs_get_classdev_attr(class_dev, "dev");
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95 if (attr == NULL)
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###### goto error;
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dbg("dev='%s'", attr->value);
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95 if (sscanf(attr->value, "%u:%u", &udev->major, &udev->minor) != 2)
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###### goto error;
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dbg("found major=%d, minor=%d", udev->major, udev->minor);
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95 return 0;
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error:
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###### return -1;
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}
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Any line of code that is preceded by a "######" implies that the code
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was never hit during execution.
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- Once you are done with using gcov for udev and want to return to your
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normal use of udev. Simply,
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./make_gcov.sh clean
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This will clean out all the *.bb, *.bbg, *.da, *.gcov files produced by gcov.
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It will also run a regular make clean on your udev directory. Then just run
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a regular make and make install and you are back to normal:
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make
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su to root
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make isntall
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