SGX Code Coverage Support

Prerequisite:

1. lcov. Install via sudo apt-get install lcov

2. Either of gcov <= 7, or llvm-cov >= 11

• gcov <= 7. Install gcc sudo apt-get install gcc. For more information around managing multiple gcc/toolchains, please refer to this article.
• llvm-cov >= 11. You can either install using apt/yum/dnf, or the official LLVM installation script:

wget https://apt.llvm.org/llvm.sh
chmod +x llvm.sh
sudo ./llvm.sh 11

If your platform cannot install either of them, you can use another platform to analyze the generated gcno and gcda files. Ubuntu 18.04 has gcc-7 by default, and can install llvm 11 using the above script.

One shot

$ COV=1 make run
$ make gen_cov_report

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

sgx_cov supports cargo-std-aware as well:

$ BUILD_STD=cargo COV=1 make run
$ BUILD_STD=cargo make gen_cov_report

sgx_cov supports xargo as well:

$ BUILD_STD=xargo COV=1 make run
$ BUILD_STD=xargo make gen_cov_report

The Magic

• Inject an on exit function using global_dtor macro, and invoke sgx_cov::cov_writeout()
• .gcno would be generated during compile time at RustEnclave_Out_Path
• .gcna would be generated during run time at RustEnclave_Out_Path
• make gen_cov_report would process .gcno and .gcna and generate html results.

More about the magic

To be continued ...