how to methodically generate a set of rules?

[Robert P. J. Day]

  i know i can do the following using one big pattern rule but it
would be cumbersome so can this be done with something approximating a
loop?

  i have a fixed set of C source files, each of which, when compiled,
will generate a small set of individual object files, and i'd like to
somehow automate the rule generation for this.

  e.g., if i have the source file s1.c which generates fred.o and
barney.o, and the source file s2.c which generates wilma.o and
betty.o, i want the rules (in simplified form):

fred.o barney.o : s1.c
        ... commands ...

wilma.o betty.o : s2.c
        ... comands ...

  now, from each source file i'm given, i can *calculate* from its
contents the object files that will be generated so being able to
loop through the set of source files and generate each rule one at a
time would be terrific.

  i don't *think* i can use "foreach" for this but i'd love to be
proven wrong.  thanks for any pointers.

rday