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diff --git a/README-gcov_for_udev b/README-gcov_for_udev new file mode 100644 index 0000000000..fa377bc4af --- /dev/null +++ b/README-gcov_for_udev @@ -0,0 +1,116 @@ +################################################ + +Using GCC's code coverage tool, gcov, with udev + +################################################ + +For more information on using gcov please see: + +http://gcc.gnu.org/onlinedocs/gcc/Gcov.html + +With that said, here is how to get code coverage analysis for udev files. +Note that this was developed with udev version 024. + +- Make sure you've installed udev and that it is working properly. + If you are having problems, refer to the README and HOWTO-udev_for_dev + documents in udev tarball. I've also compiled a udev_for_dev + toubleshooting document for Red Hat which can be found at: + + http://developer.osdl.org/ogasawara/gcov_for_udev/rh_udev_for_dev.txt + +- Get the following files: + make_gcov.sh + run_gcov.sh + + These can be found at http://developer.osdl.org/ogasawara/gcov_for_udev/ + +- After grabbing these files, copy both make_gcov.sh and run_gcov.sh + into the top level of your udev directory. + +- execute make_gcov.sh + + ./make_gcov.sh + + This will compile udev with gcov support. Basically make_gcov.sh will + run make but override the CFLAGS. It strips any optimization from + CFLAGS in order for gcov to get correct code coverage analysis. It will + also add the -fprofile-arcs and -ftest-coverage options which are the + necessary flags needed to use gcov. + + make_gcov.sh will assume the same default parameters as the regular + make but also accepts the same parameters. For example if you want + to get code coverage analysis for udev with the DEBUG flag turned + on, you would just execute: + + ./make_gcov.sh DEBUG=true + + There is one exception, gcov will not work with klibc as it does not + compile cleanly with the -fprofile-arcs and -ftest-coverage flags. + With this said it is pretty much useless to set the KERNEL_DIR flag + when using make_gcov.sh as well. + + Don't be alarmed if you look into your udev directory and see that it + has been polluted with a bunch of *.bb, *.bbg, *.da, and *.gcov files. + gcov creates and uses these files to extract the code coverage info. + +- After running make_gcov.sh you need to install udev again. So basically, + + su to root + make install + +- Then execute some udev tasks. You can run some udev tests, reboot, or + do anything your little udev heart desires. Once you are satisfied, you + can now see how much udev code was covered. + +- To get the udev code coverage analysis, execute run_gcov.sh. You need to + be root to do this. + + su to root + ./run_gcov.sh + +- This creates udev_gcov.txt which holds all the code coverage information. + To see an example of the code coverage info after executing the udev-test.pl + test, please see: + + http://developer.osdl.org/ogasawara/gcov_for_udev/udev_gcov.txt + +- Also, after having executed gcov on udev (ie executing run_gcov.sh) a + *.gcov file is created for every file which contained code that was + used. Looking at the *.gcov files, one will see what lines of code + were hit, and what lines were missed. For, example if code in udev-add.c + were executed, gcov then created a file called udev-add.c.gcov. And a + portion of udev-add.c.gov might look like: + + static int get_major_minor(struct sysfs_class_device *class_dev, struct udevice *udev) + 95 { + 95 struct sysfs_attribute *attr = NULL; + + 95 attr = sysfs_get_classdev_attr(class_dev, "dev"); + 95 if (attr == NULL) + ###### goto error; + dbg("dev='%s'", attr->value); + + 95 if (sscanf(attr->value, "%u:%u", &udev->major, &udev->minor) != 2) + ###### goto error; + dbg("found major=%d, minor=%d", udev->major, udev->minor); + + 95 return 0; + error: + ###### return -1; + } + + Any line of code that is preceded by a "######" implies that the code + was never hit during execution. + +- Once you are done with using gcov for udev and want to return to your + normal use of udev. Simply, + + ./make_gcov.sh clean + + This will clean out all the *.bb, *.bbg, *.da, *.gcov files produced by gcov. + It will also run a regular make clean on your udev directory. Then just run + a regular make and make install and you are back to normal: + + make + su to root + make isntall |