Determining patch impact on a specific config

[Nicholas Mc Guire]

Hi !

 For a given patch I would like to find out if it impacts a
 given configuration or not. Now of course one could compile the
 kernel for the configuration prior to the patch, then apply the
 patch and recompile to find out if there is an impact but I would
 be looking for some smarter solution. Checking files only 
 unfortunately will not do it, due to ifdefs and friends so make
 would detect a change and recompile even if the affeted code 
 area is actualy dropped by the preprocessor.

 What Im trying to do is find out is, how many of the e.g. stable
 fixes of 4.4-4.4.14 would have impacted a given configuration - the
 whole exercise is intended for some statistical analysis of bugs
 in linux-stable.

 Maybe this is a trivial problem - but I did not find any usable solution 
 so any ideas other than brute force compile/patch/recompile/diff *.o ?

thx!
hofrat