[CMake] CMake integration in Gradle (Android Studio)

[Robert Dailey]

I'm at a bit of a loss on finding more information. Can anyone at
least confirm that this isn't a reliable place to find the answers I'm
looking for? Does anyone have real experience with android + gradle +
cmake integration and can provide some pointers?

On Tue, Oct 25, 2016 at 8:48 AM, Robert Dailey <rcdailey.lists at gmail.com> wrote:
> I'm not sure if the CMake mailing lists are the right place to ask
> this question but I thought I'd ask just in case someone has gone down
> this path or has experience with what Google/Gradle is actually trying
> to accomplish with what seems to be a hand-built version of CMake with
> custom patches that are not in upstream repositories.
>
> Prior to switching to Android Studio / Gradle, I was using Eclipse /
> Ant. The way I did CMake integration was not really integration at
> all: I generated Ninja build scripts using CMake and implemented
> custom targets to run "ant release" after all the C++ projects were
> built. I made sure that CMake copied relevant *.so files to
> appropriate directories in the Ant structure so they are packaged with
> built APKs. That's how I did my Android development.
>
> Now that I'm integrating CMake into Gradle, first annoyance I noticed
> is that I can't use CMake 3.7 (or any external installation of CMake)
> with Android Studio. It requires a version of CMake installed through
> SDK Manager. This means I can't use the new Android toolchain
> functionality built into CMake 3.7 (sad face). But this is something I
> can work around...
>
> Next I found out that stuff I'm setting in my CMake scripts, such as
> CPP flags like `-std=c++14` and `-fexceptions` was not being applied.
> For whatever reason, Gradle is overriding these from the command line
> (I'm guessing?). So this requires me to duplicate the toolchain /
> compiler flag setup I already do in my CMake scripts now in the Gradle
> build scripts. This seems completely unnecessary and a maintenance
> burden.
>
> What I was expecting Gradle to do was essentially provide me some
> toolchain file so that CMake can find the compiler and linker to use
> and then the rest would be determined by CMake itself.
>
> Is there a way I can tell Gradle to not take so much control over
> compiler flags? I want my CMake scripts to do this. I can't imagine
> they had a good reason to do this. What have others done in this
> situation with their own Gradle + CMake integration? Looking for
> advice here, since information is sparse, especially since the Android
> Studio 2.2 CMake integration is relatively new stuff.