I'm going to learn how to debug GLSL on mobile devices today.
Of course, for the Adreno profiler to work, you have to install some framework, and X Windowing. It's not enough install the latest version, you have to install an older version.. 2.10.5 to be specific. Follow the links to the right version, https://developer.qualcomm.com/forum/qdn-forums/maximize-hardware/adreno-gpu-profiler/28484
But! Of course, for some reason either my version of Android, the particular build doesn't support the profiler. This link (https://developer.qualcomm.com/forum/qdevnet-forums/mobile-gaming-graphi...) explains the way to find out if you have the right drivers on your phone. The Samsung Note 4 does not. But, I'll check my other devices to see if I get lucky, later on.
For now, I'm going to continue trying to debug this shader. Following the instructions that Xoppa gave above. I found the bit of code in a test program that I decided to use, which does exactly as he says, but writes the vertex and fragment shaders, along with the prefix, to seperate files.
Though, since I'm using the adreno profiler, just as he suggests. I doubt I'll get much feedback. Another possibility that I'll try, I'll run the same code, and generate the aforementioned vert/frag files on mobile and see if they are any different.
I'm stuck again. The profiler isn't compiling the shader. But, not only is it not compiling the shader, it's not telling me why.. oh WHY... OH WHY WON'T THE BLEEPIN SHADER COMPILE!?!