makefile只为头文件生成文件对象吗？

Question

im having probleme in makefile . when i execute make commande in the terminal it has to generate header.o and main.o and then combine them to generate the excutable kmeans.o file,but it did not, it only generate header.o which is km.o and stop without any error message.

this is my make file :

CFLAGS = -ggdb
DEFINES = -DDEBUGGA
INCLUDES = 
LIBS = -lstdc++
EXAMPLE = kmeans.o
CC=g++

.cpp.o:
    $(CC) -c $(CFLAGS) $(DEFINES) $(INCLUDES) $<

all::   km.o kmeans.o 

km.o:   km.cpp km.hpp
gnuplot_i.o:    gnuplot_i.hpp
kmeans.o:   main.cpp

kmeans: $(EXAMPLE)
    $(CC) -o $@ $(CFLAGS) $(EXAMPLE) $(LIBS)

clean: 
    rm -f $(EXAMPLE) kmeans

The km.cpp and km.hpp is the header file and it implementation. gnuplot_i.hpp is header with its implementation. main.cpp file the file which links all these libries.

Answer 1

The default target in this makefile is all: km.o kmeans.o .

So when you run make that is what will run. So make will create those two .o files and stop.

If you want make to be the same as make kmeans then you need all: kmeans as your default rule or to move the kmeans target above the all target (since the first target is the default one).