[cmake-developers] Work on the graphviz support - compatibility ?

[Alexander Neundorf]

Hi,

in general we keep cmake as backward compatible as possible, so no builds are 
broken.

In a local branch I have a version of cmake with a small improvement to the 
graphviz support in cmake.
It turns the variable GRAPHVIZ_IGNORE_TARGETS from a list of strings into a 
list of regular expressions. I.e. everything which was before in 
GRAPHVIZ_IGNORE_TARGETS and excluded from the dot-files, is now still 
excluded, but now there may be more targets excluded (e.g. for "kio" now not 
only "kio" is excluded, but also "kio_ftp" etc.)
Also, with this change, the variable GRAPHVIZ_TARGET_IGNORE_REGEX is not 
supported anymore, so targets previously excluded from the dot-files via this 
(one) regex are now included.

Both issues can be fixed by, for the first, putting "^...$" around the string, 
and for the second by just putting the regex now into 
GRAPHVIZ_IGNORE_TARGETS .

Strictly speaking, this breaks compatibility regarding the graphviz support.
But, do we care about this ?
* it is and was completely undocumented (will write a wiki page soon)
* the changes don't influence the build itself, so no build can be broken by 
this change

What do you think ?

Alex