SGX Code Coverage Support

Prerequisite: lcov. Install via sudo apt-get install lcov

One shot

$ make COV=1
$ cd bin && ./app && cd ..
$ make gen_cov_html

Then open html/index.html, where amazing happens!

sgx_cov supports xargo as well:

$ XARGO_SGX=1 make COV=1
$ cd bin && ./app && cd ..
$ XARGO_SGX=1 make gen_cov_html

Enable feature global_exit for sgx_urts
Inject an on exit function using global_dtors_object! macro, and invoke sgx_cov::cov_writeout()
.gcno would be generated during compile time at Target_Dir
.gcna would be generated during run time at Target_dir
make gen_cov_html would process .gcno and .gcna and generate html results.

To be continued ...