Parallel iteration over lists in makefile or CMake file

Question

Is there a way to loop over multiple lists in parallel in a makefile or CMake file?

I would like to do something like the following in CMake, except AFAICT this syntax i

Answer 1

In make you can use the GNUmake table toolkit to achieve this by handling the two lists as 1-column tables:

include gmtt/gmtt.mk

# declare the lists as tables with one column
list_a := 1 a0 a1 a2 a3 a4 a5
list_b := 1 b0 b1 b2

# note: list_b is shorter and will be filled up with a default value
joined_list := $(call join-tbl,$(list_a),$(list_b), /*nil*/)

$(info $(joined_list))

# Apply a function (simply output "") on each table row, i.e. tuple
$(info $(call map-tbl,$(joined_list),))

Output:

2 a0 b0 a1 b1 a2 b2 a3 /*nil*/ a4 /*nil*/ a5 /*nil*/