gnu make: How to concat two strings

Question

Given the line:

program_OBJS := ${program_SRCS:.cpp=.o}

I would like to append .o to each filename instead of replacing .cpp with .o.

How do I do that?

Answer 1

Just a guess program_OBJS := ${program_SRCS:.cpp=.cpp.o}

Answer 2

To just append something to a list of space separated items you can use:

program_OBJS := $(foreach program,$(program_SRCS),$(program).o)

To use the substitution method (like you show in your question):

program_OBJS := $(program_SRCS:.cpp=.cpp.o)

but for that the list must contain the .cpp suffices, or the substitutions will not occur.

Answer 3

there is also addsuffix function

Answer 4

Shorter alternative, using a pattern substitution: program_OBJS := ${program_SRCS:%=%.o}