[CMake] Linking and CMakelists.txt

[Steve Johns]

Hi.

I have a project that links to an external library that I've build 
successfully (in MSVC 7.1) using

LINK_LIBRARIES()    and    LINK_DIRECTORIES()

in my CMakelists.txt file.

When I delete one or both of these directives, the project still builds!   I 
don't see how it can, without the info on how to find the library.

Then, if I futz around enough with it (imprecise term, I know), eventually 
the project will cease to build.

Then, if I futz some more, restoring  LINK_LIBRARIES()    and 
LINK_DIRECTORIES() it will build again (eventually).

I was under the impression that edits to the CMakelists.txt file were 
detected by CMake, which would then "start over" and act in accord with the 
current definitions (or lack of) in the CMakelists.txt file.

It is clear that my understanding requires correction or qualification, and 
I'd be much obliged if anyone can surmise what's occurring here and clue me 
in.

- Steve