On test-suite coverage

[Hugo Lefeuvre]

Hello!

As part of a research project, I measured the coverage achieved by Nginx's
test-suite using gcov. Taking a look at the results, my colleagues and
myself were somewhat surprised to realize that the coverage capped at about
70% line coverage and 81% function coverage; we expected something closer
to 90% line coverage.  core/nginx.c for example only gets 268 lines / 584
covered. Similarly, more than half of core/ngx_resover.c (1042 lines /
2138) is not covered.

I was wondering if I did something wrong in my measurements, if this is a
known weakness of the test-suite, and in the latter case, if this is
something that the Nginx project is open to receiving contributions on.

For the record, I built the Nginx server (version 1.20.1) with the
following configure:

./configure --sbin-path=$(pwd)/nginx --conf-path=$(pwd)/conf/nginx.conf
--pid-path=$(pwd)/nginx.pid --with-http_ssl_module
--with-http_realip_module --with-http_addition_module
--with-http_xslt_module --with-http_image_filter_module
--with-http_geoip_module --with-http_sub_module --with-http_dav_module
--with-http_flv_module --with-http_mp4_module
--with-http_gzip_static_module --with-http_gunzip_module
--with-http_random_index_module --with-http_secure_link_module
--with-http_stub_status_module --with-cc-opt="-fprofile-arcs
-ftest-coverage"  --with-ld-opt="-lgcov" --with-http_auth_request_module
--with-http_v2_module

Thanks for your work!

Cheers,
Hugo

-- 
                Hugo Lefeuvre (hle)    |    www.owl.eu.com
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