multiple targets from one recipe and parallel execution

Question

I have a project which includes a code generator which generates several .c and .h files from one input file with just one invocation of the code generator. I have a rule w

Answer 1

Answer by Ivan Zaentsev almost worked for me, with exception of the following issue. Only when running parallel make (-j2 or above), when a prerequisite of the generated file was changed, the generated file was regenerated successfully, however, the subsequent targets that depend on the generated file were not rebuilt.

The workaround I found was to provide a recipe for the generated files (the trivial copy command), besides the dependency on the intermediate target (d):

d: i1 i2
    cat i1 i2 > a.gen 
    cat i1 i2 > b.gen
    cat i1 i2 > c.gen
.INTERMEDIATE: d
a.gen : d
b.gen : d
c.gen : d

a: a.gen d
    cp $< $@
b: b.gen d
    cp $< $@
c: c.gen d
    cp $< $@

e: a b c
    some_command $@ $^

The clue was this debug output from make when running without the workaround (where 'e' was not rebuilt with make -j2, despite a,b,c being rebuilt):

       Finished prerequisites of target file `a'.
       Prerequisite `d' of target `a' does not exist.
      No recipe for `a' and no prerequisites actually changed.
      No need to remake target `a'.