[Qemu-devel] [PATCH v2] configure: Don't create symlinks to nonexistent targets

[Qemu-devel] [PATCH v2] configure: Don't create symlinks to nonexistent targets

[Peter Maydell]

When we create the symlinks to source tree files, don't create them
if the file is not actually present in the source tree; this will
happen if the file is in a git submodule that wasn't checked out.

This also avoids the odd effect where an in-source-tree configure
will end up creating the missing file as a symlink to itself.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
v2: Remove the debug printing. Oops.

 configure |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/configure b/configure
index a318d37..a648f3d 100755
--- a/configure
+++ b/configure
@@ -3564,7 +3564,9 @@ for bios_file in $source_path/pc-bios/*.bin $source_path/pc-bios/*.rom $source_p
 done
 mkdir -p $DIRS
 for f in $FILES ; do
-    test -e $f || symlink $source_path/$f $f
+    if [ -e "$source_path/$f" -a ! -e "$f" ]; then
+        symlink "$source_path/$f" "$f"
+    fi
 done
 
 # temporary config to build submodules
-- 
1.7.1

Re: [Qemu-devel] [PATCH v2] configure: Don't create symlinks to nonexistent targets

[Stefan Weil]

Am 25.05.2011 19:30, schrieb Peter Maydell:
> When we create the symlinks to source tree files, don't create them
> if the file is not actually present in the source tree; this will
> happen if the file is in a git submodule that wasn't checked out.
>
> This also avoids the odd effect where an in-source-tree configure
> will end up creating the missing file as a symlink to itself.
>
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
> v2: Remove the debug printing. Oops.
>
> configure | 4 +++-
> 1 files changed, 3 insertions(+), 1 deletions(-)
>
> diff --git a/configure b/configure
> index a318d37..a648f3d 100755
> --- a/configure
> +++ b/configure
> @@ -3564,7 +3564,9 @@ for bios_file in $source_path/pc-bios/*.bin 
> $source_path/pc-bios/*.rom $source_p
> done
> mkdir -p $DIRS
> for f in $FILES ; do
> - test -e $f || symlink $source_path/$f $f
> + if [ -e "$source_path/$f" -a ! -e "$f" ]; then
> + symlink "$source_path/$f" "$f"
> + fi
> done
>
> # temporary config to build submodules


Hi,

very good, those bad links which we get today are really annoying,
so for most developers this is an improvement.

Let me add some additional thoughts nevertheless.

* What happens if a git submodule is checked out after configure
   was done? Then the link is missing (until configure is called again).
   Maybe the links should be created from Makefile* instead from
   configure.

* On some restricted hosts which don't create symbolic links (w32),
   the copies which are created instead of links are not updated
   when the original file changes. This is not directly related to
   your change, but could be fixed, too, when the link creation is
   moved to Makefile*.

Cheers,
Stefan W.

Re: [Qemu-devel] [PATCH v2] configure: Don't create symlinks to nonexistent targets

[Paolo Bonzini]

On 05/25/2011 07:49 PM, Stefan Weil wrote:
>
> + if [ -e "$source_path/$f" -a ! -e "$f" ]; then
> + symlink "$source_path/$f" "$f"
> + fi

Please use && instead of -a, and "! [" instead of "[ !".

Paolo