1#! [syntax] 2<condition> { 3 <command or definition> 4 ... 5} 6#! [syntax] 7 8#! [0] 9win32 { 10 SOURCES += paintwidget_win.cpp 11} 12#! [0] 13 14#! [1] 15!win32 { 16 SOURCES -= paintwidget_win.cpp 17} 18#! [1] 19 20unix { 21 SOURCES += paintwidget_unix.cpp 22} 23 24#! [2] 25macx { 26 debug { 27 HEADERS += debugging.h 28 } 29} 30#! [2] 31 32#! [3] 33macx:debug { 34 HEADERS += debugging.h 35} 36#! [3] 37 38#! [4] 39win32|macx { 40 HEADERS += debugging.h 41} 42#! [4] 43