Defining OpenGL Feedback Completely Inside a Shader

Question

I am trying to run my conversion feedback. I wanted to fully specify the layout of the buffer from the shaders using the 4.4 kernel or the GL_ARB_enhanced_layouts extension using layout declarations (xfb_offset = xx). I suggested that after declaring them in the vertex shader, I can call

GLint iTransformFeedbackVars;
glGetProgramiv(m_uProgramID, GL_TRANSFORM_FEEDBACK_VARYINGS, &iTransformFeedbackVars);

to get the number of potential variables that need to be written to the conversion feedback buffer. But my opengl keeps returning 0 for "iTransformFeedbackVars". I tried to call the above command BEFORE and AFTER linking the program.

Is something missing for me, or can I even let the shader specify the variables that it wants to write, and my code creates a buffer after the shader wishes?