From 49490571bcfe24d279a66ba24198e8ba299fe58f Mon Sep 17 00:00:00 2001 From: Paolo 'Blaisorblade' Giarrusso Date: Thu, 28 Jul 2005 17:56:17 +0200 Subject: [PATCH] kbuild: describe Kbuild pitfall Whitespace is significant for make, and I just fought against this... so please apply this patch. Signed-off-by: Paolo 'Blaisorblade' Giarrusso Signed-off-by: Sam Ravnborg --- Documentation/kbuild/makefiles.txt | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'Documentation/kbuild') diff --git a/Documentation/kbuild/makefiles.txt b/Documentation/kbuild/makefiles.txt index 2616a58a5a4b..9a1586590d82 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. -- cgit v1.2.3-58-ga151