makefile: how to add a prefix to the basename?

Question

I have a list of file path like that:

FILE_PATH := a1.so a2.so bla/a3.so bla/a3.so bla/blo/a4.so....

I need to add a prefix to the basename

Answer 1

Look at Make's addprefix function.

Here is an example we use with addsuffix to place obj files one directory below the source.

SOURCE += MainThread.cpp
SOURCE += Blah.cpp

OBJ=$(join $(addsuffix ../obj/, $(dir $(SOURCE))), $(notdir $(SOURCE:.cpp=.o)))

From the make manual: http://www.gnu.org/software/make/manual/make.html

$(addprefix prefix,names...)

The argument names is regarded as a series of names, separated by whitespace; 
prefix is used as a unit. The value of prefix is prepended to the front of each 
individual name and the resulting larger names are concatenated with single 
spaces between them. For example,

              $(addprefix src/,foo bar)

produces the result `src/foo src/bar'.