[PATCH] lib/bb/build: create .old symlink for run.do_xx and log.do_xx

[PATCH] lib/bb/build: create .old symlink for run.do_xx and log.do_xx

[Nicolas Dechesne]

When they exist, keep a reference to the 'previous' (or old) build for run.do_xx
and log.do_xx files, which can be useful when debugging. The symlink are created
as run.do_xx.old and log.do_xx.old.

Signed-off-by: Nicolas Dechesne <nicolas.dechesne@linaro.org>
---
 lib/bb/build.py | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/lib/bb/build.py b/lib/bb/build.py
index 310b5c0..7cff578 100644
--- a/lib/bb/build.py
+++ b/lib/bb/build.py
@@ -246,6 +246,16 @@ def exec_func(func, d, dirs = None, pythonexception=False):
     # link won't be created as an exception would be fired.
     if task == func:
         runlink = os.path.join(tempdir, 'run.{0}'.format(task))
+        oldrunlink = os.path.join(tempdir, 'run.{0}.old'.format(task))
+
+        if oldrunlink and os.path.islink(runlink):
+            bb.utils.remove(oldrunlink)
+
+            try:
+                os.symlink(os.readlink(runlink), oldrunlink)
+            except OSError:
+                pass
+
         if runlink:
             bb.utils.remove(runlink)
 
@@ -503,7 +513,17 @@ def _exec_task(fn, task, d, quieterr):
 
     # Setup the courtesy link to the logfn
     loglink = os.path.join(tempdir, 'log.{0}'.format(task))
+    oldloglink = os.path.join(tempdir, 'log.{0}.old'.format(task))
     logfn = os.path.join(tempdir, logbase)
+
+    if oldloglink and os.path.islink(loglink):
+        bb.utils.remove(oldloglink)
+
+        try:
+            os.symlink(os.readlink(loglink), oldloglink)
+        except OSError:
+            pass
+
     if loglink:
         bb.utils.remove(loglink)
 
-- 
2.7.0

Re: [PATCH] lib/bb/build: create .old symlink for run.do_xx and log.do_xx

[Richard Purdie]

On Tue, 2016-09-06 at 12:53 +0100, Nicolas Dechesne wrote:
> When they exist, keep a reference to the 'previous' (or old) build
> for run.do_xx
> and log.do_xx files, which can be useful when debugging. The symlink
> are created
> as run.do_xx.old and log.do_xx.old.
> 
> Signed-off-by: Nicolas Dechesne <nicolas.dechesne@linaro.org>
> ---
>  lib/bb/build.py | 20 ++++++++++++++++++++
>  1 file changed, 20 insertions(+)

We keep the old logfiles around and "ls -t" is comparatively straight
forward. Do we really need this extra complexity?

Cheers,

Richard

Re: [PATCH] lib/bb/build: create .old symlink for run.do_xx and log.do_xx

[Nicolas Dechesne]

On Tue, Sep 6, 2016 at 3:19 PM, Richard Purdie
<richard.purdie@linuxfoundation.org> wrote:
> On Tue, 2016-09-06 at 12:53 +0100, Nicolas Dechesne wrote:
>> When they exist, keep a reference to the 'previous' (or old) build
>> for run.do_xx
>> and log.do_xx files, which can be useful when debugging. The symlink
>> are created
>> as run.do_xx.old and log.do_xx.old.
>>
>> Signed-off-by: Nicolas Dechesne <nicolas.dechesne@linaro.org>
>> ---
>>  lib/bb/build.py | 20 ++++++++++++++++++++
>>  1 file changed, 20 insertions(+)
>
> We keep the old logfiles around and "ls -t" is comparatively straight
> forward. Do we really need this extra complexity?

i can't really say that I *need* them, it is definitely not something
vital, just a convenience. It is often that I compare current and old,
so having convenience symlink for both seemed to be a good idea.