how-to add "warnings as error" rule to Qt .pro file?

When I usually work on a C++ project, one of the first things I do is setting up the "treat开发者_StackOverflow中文版 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.