doc: describe Kbuild pitfall
Subsystems (2)
PATCH 1/1 doc: describe Kbuild pitfall
From: Paolo 'Blaisorblade' Giarrusso <[email protected]>
Cc: Sam Ravnborg <[email protected]>
Whitespace is significant for make, and I just fought against this... so please apply this patch.
Signed-off-by Paolo 'Blaisorblade' Giarrusso <[email protected]>
---
linux-2.6.11-paolo/Documentation/kbuild/makefiles.txt | 6 ++++++ 1 files changed, 6 insertions(+)
Documentation/kbuild/makefiles.txt renamed from Documentation/kbuild/makefiles.txt~doc-add-pitfall +6 -0
@@ -872,7 +872,13 @@ When kbuild executes the following steps 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 pitfall that bit me once is that whitespace is sometimes + significant; for instance, the below will fail (note the extra space + after the comma): + target: source(s) FORCE + $(call if_changed, ld/objcopy/gzip) ld Link target. Often LDFLAGS_$@ is used to set specific options to ld.
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