View source for Testing removal of ifdef or configure checks

=#ifdef removal is risky=

Large-scale removal of "unused" ifdef or the configure checks that produce #defines is an important, but risky task.  

It is difficult (and time consuming) to prove that the code is unused and that there is no change to the compiled output.

==A script to help==

[[File:Gcc-E.py.txt]] is a Python script that wraps gcc -E to attempt to solve this dilemma, so as to provide a result that can be reasoned with via tools like [https://www.samba.org/ftp/paulus/ dirdiff]

===Getting the results===

 git checkout origin/master
 git clean -x -f -d
 CC="gcc -E" ./configure.developer && make -j
 mv bin /tmp/master-bin
 
 git checkout newbranch
 git clean -x -f -d
 CC="gcc -E" ./configure.developer && make -j

===Reading the results===
 dirdiff /tmp/master-bin bin
or
 diff -ur --ignore-matching-lines="^#" /tmp/master-bin/ bin> /tmp/diff