GNU Makefile ule

Ming Cheng writes:
 > âs  External Email
 > 
 > Hi Help desk,
 > 
 > I have a xxx.mk file. To this effect there are a couple lines I
 > can't figure out how make command works:
 > 
 > modules := abc
 > abc_type := static_library
 > abc_target := libabc.a
 > 
 > I asked the same question to gcc-help and was given some advices to
 > check your manual; especially chapter 6 and 10. At the same time I
 > was asked to clarify further to the right team.  I checked the PDF
 > file and did not find any description like
 > {module}_type/{module}_target rule. My question is whether there is
 > an implicit rule that make cmd will try to find
 > {module}_type/{module}_target variables according to defined
 > modules?

You have not provided a full example.  Your example simply assigns
three variables, but has no recipes.  Can you provide the smallest
full Makefile that illustrates your misunderstanding and then ask the
question?