Don't clobber symlinks to build directories

Don't clobber symlinks to build directories

Background: in order to use multiple build directories without the
cognitive or scripting overhead of figuring out which one is currently
in use, I keep a symlink "out/cur" pointing to the current one.

When the clobber script runs, it detects that out/cur is a build
directory (because out/cur/args.gn exists) but shutil.rmtree() fails
when applied to a symlink. This change skips the clobber when a link is
detected and leaves out/cur pointing to the real build dir. There's no
need to remove the symlink, since the original has been clobbered.

Review-Url: https://codereview.chromium.org/2642833002
Cr-Commit-Position: refs/heads/master@{#444777}
Committed: https://chromium.googlesource.com/chromium/src/+/29acddfbe7b3c92cd85d99e416f920849d011ec1

[sfiera, 2017-01-18 16:38:06]

sfiera@chromium.org changed reviewers:
+ dpranke@chromium.org

[Dirk Pranke, 2017-01-18 21:04:16]

How are you using this script that you're running into this problem?

I don't even know if or where this script is still used.

@thakis - do you know?

I'd probably vote for just deleting it.

[Nico, 2017-01-18 21:29:41]

thakis@chromium.org changed reviewers:
+ thakis@chromium.org

[Nico, 2017-01-18 21:29:41]

i think src/build/landmines.py uses this

[Dirk Pranke, 2017-01-19 02:00:20]

On 2017/01/18 21:29:41, Nico wrote:
> i think src/build/landmines.py uses this

Ah, you're right. 

At any rate, os.path.islink() works the same on windows, so you should just call
that generically.

[sfiera, 2017-01-19 10:17:24]

On 2017/01/18 21:29:41, Nico wrote:
> i think src/build/landmines.py uses this

Yep. I got one while building iOS.

On 2017/01/19 02:00:20, Dirk Pranke wrote:
> At any rate, os.path.islink() works the same on windows, so you should just
call
> that generically.

Done.

[sfiera, 2017-01-19 10:17:38]

The CQ bit was checked by sfiera@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-01-19 10:17:50]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-01-19 10:24:14]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-01-19 10:24:14]

Dry run: This issue passed the CQ dry run.

[Dirk Pranke, 2017-01-19 17:33:15]

lgtm

[sfiera, 2017-01-19 17:35:32]

Description was changed from

==========
Don't clobber symlinks to build directories

Background: in order to use multiple build directories without the
cognitive or scripting overhead of figuring out which one is currently
in use, I keep a symlink "out/cur" pointing to the current one.

When the clobber script runs, it detects that out/cur is a build
directory (because out/cur/args.gn exists) but shutil.rmtree() fails
when applied to a symlink. This change skips the clobber when a link is
detected and leaves out/cur pointing to the real build dir. There's no
need to remove the symlink, since the original has been clobbered.

This change isn't applied to Windows, because I'm not familiar enough
with Windows to know what os.path.islink() means there (if anything).
==========

to

==========
Don't clobber symlinks to build directories

Background: in order to use multiple build directories without the
cognitive or scripting overhead of figuring out which one is currently
in use, I keep a symlink "out/cur" pointing to the current one.

When the clobber script runs, it detects that out/cur is a build
directory (because out/cur/args.gn exists) but shutil.rmtree() fails
when applied to a symlink. This change skips the clobber when a link is
detected and leaves out/cur pointing to the real build dir. There's no
need to remove the symlink, since the original has been clobbered.
==========

[sfiera, 2017-01-19 17:35:42]

The CQ bit was checked by sfiera@chromium.org

[commit-bot: I haz the power, 2017-01-19 17:36:23]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-01-19 17:43:01]

CQ is committing da patch.

Bot data: {"patchset_id": 20001, "attempt_start_ts": 1484847342719770,
"parent_rev": "151d7ef2a6bb9d6106aa4f3cfc658b9916371ef1", "commit_rev":
"29acddfbe7b3c92cd85d99e416f920849d011ec1"}

[commit-bot: I haz the power, 2017-01-19 17:43:33]

Description was changed from

==========
Don't clobber symlinks to build directories

Background: in order to use multiple build directories without the
cognitive or scripting overhead of figuring out which one is currently
in use, I keep a symlink "out/cur" pointing to the current one.

When the clobber script runs, it detects that out/cur is a build
directory (because out/cur/args.gn exists) but shutil.rmtree() fails
when applied to a symlink. This change skips the clobber when a link is
detected and leaves out/cur pointing to the real build dir. There's no
need to remove the symlink, since the original has been clobbered.
==========

to

==========
Don't clobber symlinks to build directories

Background: in order to use multiple build directories without the
cognitive or scripting overhead of figuring out which one is currently
in use, I keep a symlink "out/cur" pointing to the current one.

When the clobber script runs, it detects that out/cur is a build
directory (because out/cur/args.gn exists) but shutil.rmtree() fails
when applied to a symlink. This change skips the clobber when a link is
detected and leaves out/cur pointing to the real build dir. There's no
need to remove the symlink, since the original has been clobbered.

Review-Url: https://codereview.chromium.org/2642833002
Cr-Commit-Position: refs/heads/master@{#444777}
Committed:
https://chromium.googlesource.com/chromium/src/+/29acddfbe7b3c92cd85d99e416f9...
==========

[commit-bot: I haz the power, 2017-01-19 17:43:34]

Committed patchset #2 (id:20001) as
https://chromium.googlesource.com/chromium/src/+/29acddfbe7b3c92cd85d99e416f9...