Generating code coverage reports

<p>I have a patch that I will be submitting to add to the build system the capability of reporting on test code
coveragemetrics for the test suite. Actually it can show coverage for any application run against PostgreSQL. Download
<ahref="http://wiki.postgresql.org/wiki/Image:Coverage.tar.gz" title="Image:Coverage.tar.gz">Image:Coverage.tar.gz</a>
tosee an example report. Gunzip and un-tar the file and click on coverage/index.html. I had to delete most of the files
todecrease the file size for upload, so only the links for access work. <p>gcov reports line, branch, and function
coverage,but lcov only reports on line coverage. I've added a link to the html to the gcov output that shows summary
statisticsfor each file for line, branch, and function calls. <p>The report gives a very clear and browseable view of
whatparts of the system might benefit from more extensive testing. It's obviously useful for planning future testing,
butalso can be used in conjunction with debugging to see what lines and functions are being exercised or missed by
existingtests of the functionality under investigation. It could even be helpful to give a static view of lines hit by
abug test case in lieue of using a debugger. Also, when you're writing a unit test for new functionality, it would be
goodto check what you're actually hitting with the test. <p>It uses gcov together with gcc to generate the statistics,
andthe lcov suite to create the html report. Both of these would obviously have to be installed to get a coverage
report,but this would be an optional feature of the build. It only works with gcc. <p>To generate coverage statistics,
yourun configure with --enable-coverage and after building and running tests, you do make coverage. The process
generatesdata files in the same directories as source & object files and produces a coverage directory at the top
levelwith the html files. I've also set it up so a tar file with the html is generated. <p>More information on gcov at
<aclass="external free" href="http://gcc.gnu.org/onlinedocs/gcc/Gcov.html" rel="nofollow"
title="http://gcc.gnu.org/onlinedocs/gcc/Gcov.html">http://gcc.gnu.org/onlinedocs/gcc/Gcov.html</a>,lcov at <a
class="externalfree" href="http://ltp.sourceforge.net/documentation/how-to/ltp.php" rel="nofollow"
title="http://ltp.sourceforge.net/documentation/how-to/ltp.php">http://ltp.sourceforge.net/documentation/how-to/ltp.php</a>
(coverage/lcovtabs).<br /><p>-- Michelle<br /><pre class="moz-signature" cols="72">-- 
 
Michelle Caisse               Sun Microsystems
California, U.S.     <a class="moz-txt-link-freetext" href="http://sun.com/postgresql">http://sun.com/postgresql</a>

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