When I usually work on a C++ project, one of the first things I do is setting up the "treat warning as errors" on my compiler.
When using Qt, qmake generates the Makefile for you and doesn't include this option on the compilation commands. I'm pretty sure there is a way to add such an option (and others) into the generated Makefile but I couldn't figure it out.
How would I do that ?
I'm using the open-source version of Qt with g++ as the compiler.
You can use QMAKE_CXXFLAGS in pro file to specify compiler flags:
QMAKE_CXXFLAGS += -Werror The solution above is for GCC only. For both compillers (VS and gcc) use:
win32-g++ { QMAKE_CXXFLAGS += -Werror } win32-msvc*{ QMAKE_CXXFLAGS += /WX } 
There is a QMake variable called QMAKE_CXXFLAGS_WARN_ON which is included into CXXFLAGS whenever CONFIG contains warn_on.
So my project files all include a common.pri which contains:
CONFIG += warn_on dirty_build: CONFIG += noopt !dirty_build: WARNINGS += -Werror # Turn on warnings, except for code that is Qt-generated WARNINGS += -Wextra WARNINGS += -Wunknown-pragmas -Wundef WARNINGS += -Wold-style-cast WARNINGS += -Wdisabled-optimization -Wstrict-overflow=4 WARNINGS += -Weffc++ -Wuseless-cast WARNINGS += -Winit-self -Wpointer-arith WARNINGS += -Wlogical-op WARNINGS += -Wunsafe-loop-optimizations -Wno-error=unsafe-loop-optimizations QMAKE_CXXFLAGS_WARN_ON += $(and $(filter-out moc_% qrc_%, $@),$${WARNINGS}) The filter-out exists to disable the warnings for Qt-generated meta-object and resource files.
I also have
# Override the C and C++ targets to selectively replace -I with -isystem for include paths QMAKE_RUN_CC = $(CC) -o $obj -c $(CFLAGS) $(subst -I/usr/include,-isystem /usr/include,$(INCPATH)) $src QMAKE_RUN_CC_IMP = $(CC) -o $@ -c $(CFLAGS) $(subst -I/usr/include,-isystem /usr/include,$(INCPATH)) $< QMAKE_RUN_CXX = $(CXX) -o $obj -c $(CXXFLAGS) $(subst -I/usr/include,-isystem /usr/include,$(INCPATH)) $src QMAKE_RUN_CXX_IMP = $(CXX) -o $@ -c $(CXXFLAGS) $(subst -I/usr/include,-isystem /usr/include,$(INCPATH)) $< That allows me to enable -Weffc++ and others without incurring lots of messages from installed header files.