Debianized way to add -O2 to CFLAGS without using CDBS in Qt project

What is the standard mechanism to deliver compiler optimization level information in debianized source using qmake without using cdbs?

For example, if DEB_BUILD_OPTIONS doesn't have noopt defined, -O2 should go into CFLAGS. Everytime I try to specify CFLAGS myself in debian/rules, it gets overwritten by Makefile that was generated by qmake system.

Any help is a开发者_StackOverflow社区ppreciated!

Do you have control over the qmake .pro file? If yes, you could use qmake's $$() or $() syntax to use the value of the environment variable either during Makefile generation or evaluation.

Another (more involved) option might be to set the QMAKESPEC environment variable to make qmake use another base configuration.