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[Qemu-devel] [PATCH] configure: make source tree build more robust
From: |
Michael S. Tsirkin |
Subject: |
[Qemu-devel] [PATCH] configure: make source tree build more robust |
Date: |
Mon, 28 Apr 2014 15:21:15 +0300 |
When source directory can be arrived at by two paths,
configure might misdetect an out of tree build.
The simplest way to trigger the problem is running
configure using a full path. E.g. (<firstpath> refers to qemu source
tree):
ln -s <firstpath> <secondpath>
cd <firstpath>
<secondpath>/configure
A more practical way is when make runs configure automatically:
1. cd <firstpath>/; ./configure
SRC_PATH=<firstpath>/ is written into config_host.mak
2. cd <secondpath>/; touch configure; make
make now runs <firstpath>/configure, so configure
assumes it's an out of tree build
When this happens configure overwrites parts of
the current tree with symlinks.
Make the test more robust: create a canary file under
the build tree, then look for it in the source tree.
If there - we know it's a source build!
Signed-off-by: Michael S. Tsirkin <address@hidden>
---
configure | 20 ++++++++++++++++++--
1 file changed, 18 insertions(+), 2 deletions(-)
diff --git a/configure b/configure
index b08afc3..4a59cb7 100755
--- a/configure
+++ b/configure
@@ -404,6 +404,22 @@ fi
# make source path absolute
source_path=`cd "$source_path"; pwd`
+# running configure in the source tree? create a temporary file
+# under pwd, check for it in source tree. Use .o suffix so that
+# make clean will blow it away if
+canary_path=`pwd`
+canary_fullpath=`mktemp "$canary_path/canary.XXXXXXXXXX.o"`
+if test -z "$canary_fullpath"; then
+ error_exit "Current directory $canary_path/ does not appear to be
writeable"
+fi
+canary_basename=`basename "$canary_fullpath"`
+if test -e "$source_path/$canary_basename"; then
+ pwd_is_source_path="y"
+else
+ pwd_is_source_path="n"
+fi
+rm -f -- "$canary_fullpath"
+
check_define() {
cat > $TMPC <<EOF
#if !defined($1)
@@ -2940,7 +2956,7 @@ EOF
fdt=yes
dtc_internal="yes"
mkdir -p dtc
- if [ "$source_path" != `pwd` ] ; then
+ if [ "$pwd_is_source_path" != "y" ] ; then
symlink "$source_path/dtc/Makefile" "dtc/Makefile"
symlink "$source_path/dtc/scripts" "dtc/scripts"
fi
@@ -5178,7 +5194,7 @@ do
done
mkdir -p $DIRS
for f in $FILES ; do
- if [ -e "$source_path/$f" ] && [ "$source_path" != `pwd` ]; then
+ if [ -e "$source_path/$f" ] && [ "$pwd_is_source_path" != "y" ]; then
symlink "$source_path/$f" "$f"
fi
done
--
MST
- [Qemu-devel] [PATCH] configure: make source tree build more robust,
Michael S. Tsirkin <=