Display code in appropriate #ifdef block according to the value of identifier

Question

I have a C codebase with source files using #ifdef blocks all over. There are multiple identifiers and corresponding ifdefs (with the ifdefs nested to multiple levels). While viewing the code in vim, is there a way for me to define multiple identifiers and view/highlight my code such that I see only those ifdef blocks which are applicable when an identifier is defined.

#if defined(ID1) && (ID1 == 1)
// code 1
#elif defined(ID1) && (ID1 == 2)
// code 2

When set ID=1, my view should only display/highlight code 1, when ID=2 my view should only display/highlight code 2, otherwise if ID is not defined, both code 1 and code 2 should not be highlighted or displayed.

Answer 1

DISCLAIMER

This is generally a bad idea. You never want to hide text in a source file. 
Compiling different code branches based on flags set at compile time is a 
different story. But viewing the code, you should always see what you ask 
the compiler to build

That said, if you want to hide code when reading, there are a couple ways you can achieve that

1. Fold it: See :help fold for more details
2. Syntax: junegunn/limelight.vim is a good tool to selectively turn off syntax highlighting for code spaces outside the region your cursor is in.