diff --git a/Documentation/kbuild/makefiles.txt b/Documentation/kbuild/makefiles.txt index 2616a58a5a4b829a3fb951e305cf6af37aee4cfa..9a1586590d827fcb11943247362c527dbe419105 100644 --- a/Documentation/kbuild/makefiles.txt +++ b/Documentation/kbuild/makefiles.txt @@ -872,7 +872,13 @@ When kbuild executes the following steps are followed (roughly): Assignments to $(targets) are without $(obj)/ prefix. if_changed may be used in conjunction with custom commands as defined in 6.7 "Custom kbuild commands". + Note: It is a typical mistake to forget the FORCE prerequisite. + Another common pitfall is that whitespace is sometimes + significant; for instance, the below will fail (note the extra space + after the comma): + target: source(s) FORCE + #WRONG!# $(call if_changed, ld/objcopy/gzip) ld Link target. Often LDFLAGS_$@ is used to set specific options to ld.