[CMake] CMake integration in Gradle (Android Studio)

[Robert Dailey]

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.