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 <[email protected]>

Cc: Milton Miller <[email protected]>
Signed-off-by: Sam Ravnborg <[email protected]>
This commit is contained in:
Sam Ravnborg 2006-08-08 21:35:14 +02:00 • committed by Sam Ravnborg
commit 45d506bd65
2 changed files with 41 additions and 1 deletions

View file

@ -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'