path: root/Makefile
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authorSam Ravnborg <>2006-08-08 21:35:14 +0200
committerSam Ravnborg <>2006-09-25 09:01:49 +0200
commit45d506bd65e2e35881d8276c111b647807823d19 (patch)
tree8f53e4e58165fc2c7f62e17b31dfb77ef43d7dfc /Makefile
parent12715d20af9fd9179daca7a1cd2cf3db3c2c494f (diff)
kbuild: make V=2 tell why a target is rebuild
tell why a a target got build enabled by make V=2 Output (listed in the order they are checked): (1) - due to target is PHONY (2) - due to target missing (3) - due to: file1.h file2.h (4) - due to command line change (5) - due to missing .cmd file (6) - due to target not in $(targets) (1) We always build PHONY targets (2) No target, so we better build it (3) Prerequisite is newer than target (4) The command line stored in the file named dir/.target.cmd differed from actual command line. This happens when compiler options changes (5) No dir/.target.cmd file (used to store command line) (6) No dir/.target.cmd file and target not listed in $(targets) This is a good hint that there is a bug in the kbuild file This patch is inspired by a patch from: Milton Miller <> Cc: Milton Miller <> Signed-off-by: Sam Ravnborg <>
Diffstat (limited to 'Makefile')
1 files changed, 1 insertions, 0 deletions
diff --git a/Makefile b/Makefile
index 22451c2ac1e..440a1331d88 100644
--- a/Makefile
+++ b/Makefile
@@ -1101,6 +1101,7 @@ help:
echo '')
@echo ' make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
+ @echo ' make V=2 [targets] 2 => give reason for rebuild of target'
@echo ' make O=dir [targets] Locate all output files in "dir", including .config'
@echo ' make C=1 [targets] Check all c source with $$CHECK (sparse by default)'
@echo ' make C=2 [targets] Force check of all c source with $$CHECK'