[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 <blaisorblade@yahoo.it>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

1 files changed, 6 insertions, 0 deletions

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.