@DavidSiegel is right, but I'd like to add:
The whole copyleft issue hinges basically on the question whether the "utilizing" tightly integrates that copyleft code/program/library (with the exception of system libraries). If the project links or intimately integrates the copyleft program/library/code (think: it cannot work without that) then copyleft would kick in.
This is not the case with using a GPLed tool processes (a part of) your project and which is not further required for using the product of this processing. The GPL FAQ actually answers the very question on
Can I use GPL-covered editors such as GNU Emacs to develop nonfree programs? Can I use GPL-covered tools such as GCC to compile them?
Yes, because the copyright on the editors and tools does not cover the code you write. Using them does not place any restrictions, legally, on the license you use for your code.
[... snip: there's more there on the more complicated case of tools that copy parts of their own GPLed code into the product ...]
There are other ways of "utilizing" non-free software, also covered in those FAQ, e.g.:
If a programming language interpreter is released under the GPL, does that mean programs written to be interpreted by it must be under GPL-compatible licenses?
When the interpreter just interprets a language, the answer is no. The interpreted program, to the interpreter, is just data; a free software license like the GPL, based on copyright law, cannot limit what data you use the interpreter on. You can run it on any data (interpreted program), any way you like, and there are no requirements about licensing that data to anyone.
However, when the interpreter is extended to provide “bindings” to other facilities (often, but not necessarily, libraries), the interpreted program is effectively linked to the facilities it uses through these bindings. So if these facilities are released under the GPL, the interpreted program that uses them must be released in a GPL-compatible way. The JNI or Java Native Interface is an example of such a binding mechanism; libraries that are accessed in this way are linked dynamically with the Java programs that call them. These libraries are also linked with the interpreter. If the interpreter is linked statically with these libraries, or if it is designed to link dynamically with these specific libraries, then it too needs to be released in a GPL-compatible way.
Another similar and very common case is to provide libraries with the interpreter which are themselves interpreted. For instance, Perl comes with many Perl modules, and a Java implementation comes with many Java classes. These libraries and the programs that call them are always dynamically linked together.
A consequence is that if you choose to use GPLed Perl modules or Java classes in your program, you must release the program in a GPL-compatible way, regardless of the license used in the Perl or Java interpreter that the combined Perl or Java program will run on.