GNU make - Setting Go to the first , previous , next , last section, table of contents .
See section The Two Flavors of Variables . The variable name may contain function and variable references, which are expanded when the line is read to find the actual variable name to use. There is no limit on the length of the value of a variable except the amount of swapping space on the computer. When a variable definition is long, it is a good idea to break it into several lines by inserting backslash-newline at convenient places in the definition. This will not affect the functioning of make , but it will make the makefile easier to read.