Check for flags in Makefile

How to ch开发者_开发技巧eck for flags in Makefile ? Suppose I run make -a, I need to be able to do certain things, How do I detect if the flag is set inside a Makefile ?

If you're using GNUMake, you can check MAKEFLAGS, like this:

someTarget: 
    ifneq (,$(findstring a,$(MAKEFLAGS)))
      do something
    else
      do something else
    endif