https://www.tessapower.co/back-to-basics/

[tessapower]

Back to basics: using GoogleTest without CMake for C++ projects

[clo64]

Hello. I'm trying to make this work and have a question. What directory are you running clang in? I see that you're using the argument **/*.cc. Are you compiling the googletest/src files?
I trying to work this out and getting a long list of undefined references.

[tessapower]

Thanks for your question! In general, I’d run this command from the root folder of the project. The **/*.cc part of this original command indicates that clang++ will compile any .cc file it finds in the current directory or any subdirectories. We're not compiling the googletest/src files, we're only linking against them. This could be troublesome if you have a main.cc or app.cc file that contains a main function, as this clashes with GTest’s main function (insert there-can-be-only-one.jpg 😛). What you basically want to do is link your headers and source files against only GTest’s main, which you do by using the -lgtest_main and -lgtest flags.

Since writing this post, I’ve refined my usage of GTest and how I lay out small projects. The command has evolved into this:

clang++ \
-fcolor-diagnostics \
-pthread \
-lgtest_main \
-lgtest \
-Iinclude \
-o ./dist/main_tests \
./tests/*.cc ./src/*.cc \
2>&1 \
&& ./dist/main_tests \
--gtest_color=yes

What this command does is look for any .cc files in the test and srcdirectories, compile them (including any necessary headers from the include directory), link against -lgtest_main and -lgtest and then create an object (main_tests) in the dist directory which is then run to execute the tests. The extra flags for color just make things prettier in your terminal.

You’ll notice there are a few assumptions about the structure of the project directory. Here’s what my typical project directory structure looks like:

.
├── Makefile
├── bin
│   └── main.cc
├── dist
│   ├── main
│   └── main_tests
├── include
│   ├── Factorial.h
│   └── Prime.h
├── src
│   ├── Factorial.cc
│   └── Prime.cc
└── tests
    ├── factorial_tests.cc
    └── prime_tests.cc

Hopefully this answers your questions. If not, please feel free to send screenshots and the structure of your project and I'll try to help as best I can.

[clo64]

Oi!!
You saved my life; I've got it working. I spent all of yesterday on this. I'm trying to integrate Gtest into a legacy embedded project that doesn't use CMake, hence landing on this page.
Many thanks from the US and safe software engineering travels.

[tessapower]

I'm so glad I could help! All the best with the legacy project 😄