variable target in a makefile
I am trying to compile set of targets. However it only seems to do the first one. Below is a cut down of the my makefile that shows the error.
OBJECTS = abc def ghi
SOURCES = abc.c def.c ghi.c
$(OBJECTS): $(SOURCES)
@echo target is $@, source is $<
In shell,
$ touc开发者_C百科h abc.c def.c ghi.c
$ make
When I run make I get the following output:
target is abc, source is abc.c
So it only seems to be running the first target.
If I replace $< with $^, the output is:
target is abc, source is abc.c def.c ghi.c
My question, is it possible to perform expansions on variables like with the (%: %) pattern?
Try this:
OBJECTS = abc def ghi
all: $(OBJECTS)
$(OBJECTS):%:%.c
@echo target is $@, source is $<
The trouble was
- The default target (which is what Make chooses if you just type `make`) is the first target in the makefile, which was `abc`.
- You made all sources prerequisites of every object. That is, all three sources were prerequisites of `abc`. They were also prerequisites of `def` and of `ghi`.
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