Question

Can someone explain how to use if-then statements and for loops in Makefiles? I can’t seem to find any good documentation with examples.

Answer 1

Conditional Forms

Simple

conditional-directive text-if-true endif 

Moderately Complex

conditional-directive text-if-true else text-if-false endif 

More Complex

conditional-directive text-if-one-is-true else conditional-directive text-if-true else text-if-false endif endif 

Conditional Directives

If Equal Syntax

ifeq (arg1, arg2) ifeq 'arg1' 'arg2' ifeq 'arg1' 'arg2' ifeq 'arg1' 'arg2' ifeq 'arg1' 'arg2' 

If Not Equal Syntax

ifneq (arg1, arg2) ifneq 'arg1' 'arg2' ifneq 'arg1' 'arg2' ifneq 'arg1' 'arg2' ifneq 'arg1' 'arg2' 

If Defined Syntax

ifdef variable-name 

If Not Defined Syntax

ifndef variable-name   

foreach Function

foreach Function Syntax

$(foreach var, list, text)   

foreach Semantics
For each whitespace separated word in ‘list’, the variable named by ‘var’ is set to that word and text is executed.