GLSL: missing uniform location

I have faced with such a feature of the GLSL compiler. If the variable is not used in the shader, then find its location there would be no possibility, it is simply truncated from the shader.

The search function on behalf of the Uniform position.
int loc = glGetUniformLocationARB ( , );

Moreover, even if caught insidious, like the variable is used, but the result of further calculations is not, and that’s why, again, to find the ancestral variable is not possible.

Graphics, Programming C++, GLSL, OpenGL