Re: GNU Make: Add something to CXXFLAGS when invoking make

[James]

Eric Lilja wrote:
> Hello, can you do what the topic says?
> I tried:
> hivemind@mindcooler
> ~/jobb/example_programs/overloaded_comparison_operators
> $ make CXXFLAGS+='-DFRIEND
> but instead of adding -DFRIEND to CXXFLAGS, it replaced it...the
> Makefile itself is:
> CXX =g++
> CXXFLAGS = -Wall -Wextra -std=c++98 -pedantic -g -c
> LDFLAGS = -o $(EXEC)
> EXEC = overloaded_comparison_operators.exe
> OBJECTS = overloaded_comparison_operators.o
>
> all: $(OBJECTS)
>       $(CXX) $^ $(LDFLAGS)
>
> overloaded_comparison_operators.o: overloaded_comparison_operators.cpp
>       $(CXX) $(CXXFLAGS) $<
>
> clean:
>       rm -f $(OBJECTS) $(EXEC) *~ *.stackdump
>
> I'm trying to avoid writing several Makefiles or having to specify the
> other CXXFLAGS on the command line other than the defines I want at the
> moment.
>
> / E

CXXFLAGS = -Wall -Wextra -std=c++98 -pedantic -g -c $(EXTRA_CXXFLAGS)

make EXTRA_CXXFLAGS=-DFRIEND

James