If we try to do an out-of-tree build but the source tree we're building from has been used in the past for an in-tree build then things will go confusingly wrong. Specifically, some parts of the build process will pull in generated files from the old in-tree build (because SRC_PATH is on the vpath). Diagnose this situation so we can produce a useful error message and tell the user how to fix it (run distclean in the source tree).
Signed-off-by: Peter Maydell <peter.mayd...@linaro.org> --- I got bitten by this again the other day so I figured it was worth adding a molly-guard. The check is not perfect (it won't notice if you did a distclean but didn't delete the *-softmmu &c directories, for instance) but it should catch most cases of this user error. Makefile | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/Makefile b/Makefile index a9c22bf..5094a08 100644 --- a/Makefile +++ b/Makefile @@ -8,6 +8,17 @@ ifneq ($(wildcard config-host.mak),) # Put the all: rule here so that config-host.mak can contain dependencies. all: include config-host.mak + +# Check that we're not trying to do an out-of-tree build from +# a tree that's been used for an in-tree build. +ifneq ($(realpath $(SRC_PATH)),$(realpath .)) +ifneq ($(wildcard $(SRC_PATH)/config-host.mak),) +$(error This is an out of tree build but your source tree ($(SRC_PATH)) \ +seems to have been used for an in-tree build. You can fix this by running \ +"make distclean && rm -rf *-linux-user *-softmmu" in your source tree) +endif +endif + include $(SRC_PATH)/rules.mak config-host.mak: $(SRC_PATH)/configure @echo $@ is out-of-date, running configure -- 1.7.9.5