Re: [Qemu-devel] [PATCH v2] configure: make source tree build more robust

[Paolo Bonzini]

Il 28/04/2014 16:23, Michael S. Tsirkin ha scritto:

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. ( refers to qemu source
tree):
ln -s  
cd 
/configure

A more practical way is when make runs configure automatically:

1. cd /; ./configure
SRC_PATH=/ is written into config_host.mak
2. cd /; touch configure; make
make now runs /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: look for configure
in the current directory.
If there - we know it's a source build!

Signed-off-by: Michael S. Tsirkin 
---

changes from v1: simpler, more portable heuristic
for detecting out of tree builds.

 configure | 12 ++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/configure b/configure
index 69b9f56..dd36e54 100755
--- a/configure
+++ b/configure
@@ -404,6 +404,14 @@ fi
 # make source path absolute
 source_path=`cd "$source_path"; pwd`

+# running configure in the source tree?
+# we know that's the case if configure is there.
+if test -f "./configure"; then
+pwd_is_source_path="y"
+else
+pwd_is_source_path="n"
+fi
+
 check_define() {
 cat > $TMPC <

I'll take care of sending a pull request for this.  Thanks!

Paolo

Re: [Qemu-devel] [PATCH v2] configure: make source tree build more robust

[Peter Maydell]

On 28 April 2014 15:23, Michael S. Tsirkin  wrote:
> @@ -5179,7 +5187,7 @@ 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

It seems a bit silly to do the "are we in the source
directory?" check for every file rather than just once
outside the loop, but that's a separate bug so we should
address it in a separate patch (or ignore it ;-))

thanks
-- PMM

Re: [Qemu-devel] [PATCH v2] configure: make source tree build more robust

[Paolo Bonzini]

Il 28/04/2014 16:23, Michael S. Tsirkin ha scritto:

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. ( refers to qemu source
tree):
ln -s  
cd 
/configure

A more practical way is when make runs configure automatically:

1. cd /; ./configure
SRC_PATH=/ is written into config_host.mak
2. cd /; touch configure; make
make now runs /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: look for configure
in the current directory.
If there - we know it's a source build!

Signed-off-by: Michael S. Tsirkin 
---

changes from v1: simpler, more portable heuristic
for detecting out of tree builds.

 configure | 12 ++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/configure b/configure
index 69b9f56..dd36e54 100755
--- a/configure
+++ b/configure
@@ -404,6 +404,14 @@ fi
 # make source path absolute
 source_path=`cd "$source_path"; pwd`

+# running configure in the source tree?
+# we know that's the case if configure is there.
+if test -f "./configure"; then
+pwd_is_source_path="y"
+else
+pwd_is_source_path="n"
+fi
+
 check_define() {
 cat > $TMPC <

Reviewed-by: Paolo Bonzini 

Paolo