CODEWITHSUNDEEP
makefile
hetepeperfan
hetepeperfan

Reputation: 4411

makefile doesn't build targets

I've got a makefile, the makefile should create a number of shared object files. These file are going to be python modules. In the all target has the modules as dependencies. The swig wrappers (.cpp) fils are create as I would expect via the swig program, the .cpp are compiled as .o object files, however, the modules aren't created.

My makefile looks like:

CXXFLAGS        :=$(CXXFLAGS) -fpic $(PYTHON3_CFLAGS)
LDLIBS          :=$(LDLIBS) $(PYTHON3_LIBS)

SWIG=swig
SWIG_FLAGS:=-Wall -c++ -python #-DSWIG_TYPE_TABLE=fam #-external-runtime swigpyrun.h

IFACE_FILES += person.i
IFACE_FILES += parent.i
IFACE_FILES += child.i

WRAPPER_FILES = $(IFACE_FILES:.i=_wrap.cpp)
OBJS = $(WRAPPER_FILES:.cpp=.o)
MODULES = $(addprefix _, $(IFACE_FILES:.i=.so))

all:_person.so _child.so _parent.so #$(MODULES)

$(OBJS):$(WRAPPER_FILES)

$(MODULES):$(OBJS)

_%.so:%.cpp
    $(CXX) -shared -o $@ $<

%_wrap.cpp:%.i
    $(SWIG) $(SWIG_FLAGS) -o $@ $< 

clean:
    $(RM) $(WRAPPER_FILES)
    $(RM) $(OBJS)
    $(RM) $(MODULES)

When I run it I obtain:

$ make clean
rm -f person_wrap.cpp parent_wrap.cpp child_wrap.cpp
rm -f person_wrap.o parent_wrap.o child_wrap.o
rm -f _person.so _parent.so _child.so

$ make
swig -Wall -c++ -python  -o person_wrap.cpp person.i 
swig -Wall -c++ -python  -o parent_wrap.cpp parent.i 
swig -Wall -c++ -python  -o child_wrap.cpp child.i 
g++  -fpic `pkg-config --cflags python3`   -c -o person_wrap.o person_wrap.cpp
g++  -fpic `pkg-config --cflags python3`   -c -o parent_wrap.o parent_wrap.cpp
g++  -fpic `pkg-config --cflags python3`   -c -o child_wrap.o child_wrap.cpp

$ make
make: Nothing to be done for 'all'.

So I must be doing something wrong, since the .so files aren't created/linked. But what am I missing?

Upvotes: 1

Views: 75

Answers (2)

Beta
Beta

Reputation: 99094

You intend (I think) that the pipeline should run

person.i => person_wrap.cpp => person.o => _person.so

But look at these two rules:

$(MODULES):$(OBJS)

_%.so:%.cpp
    $(CXX) -shared -o $@ $<

You ask for _person.so, the second rule can build _person.so from person.cpp, but there is no person.cpp and no way to build it. The first rule covers _person.so, and has as its prerequisites person_wrap.o parent_wrap.o child_wrap.o, which can be built, but it has no commands, so Make executes it-- and does nothing.

It's difficult to test, but I think eliminating your $(MODULES) rule and making a slight modification:

_%.so:%_wrap.o
    $(CXX) -shared -o $@ $<

will give you the effect you want.

Upvotes: 1

rveerd
rveerd

Reputation: 4006

You are trying to link your .so from your .cpp files, but you should link from your .o files:

_%.so: wrap_%.o
    $(CXX) -shared -o $@ $<

Upvotes: 1

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