Remove java.io in FileUtils

[sinofp]

1. Add getPath to turn a String to os.Path.
2. Replace java.io.File methods with os-lib functions.

Contributor Checklist

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• Did you add at least one test demonstrating the PR?
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Type of Improvement

• code refactoring

• new feature/API
• deprecation

API Impact

Backend Code Generation Impact

Desired Merge Strategy

• Rebase: You will rebase the PR onto master and it will be merged with a merge commit.

Release Notes

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[sequencer]

Generally LGMT, just need deprecation annotations.

[sequencer]

LGTM, this is the first step to remove complex Java.IO.

[sequencer]

See you in your next PR @sinofp 👍

[jackkoenig]

I'm a bit late here, but it seems this is enshrining use of absolute paths which I understand is convenient but is actually generally not a great thing to do since it makes runs not relocatable (eg. if I emit files with absolute paths in them, then the one in my workspace is different than the one in your work space).

To be fair, I'm not sure if the existing APIs are already very "absolutely path centric" but it's generally something we should move away from rather than encouraging.

[mwachs5]

@sinofp , @sequencer what do I need to upgrade to get this os. variable? Bumping from 3.4 branch to master I am getting a bunch of FileUtils.scala: not found: value os... is this assuming a certain Scala version? I'm on 2.12.13

[sequencer]

@sinofp , @sequencer what do I need to upgrade to get this os. variable? Bumping from 3.4 branch to master I am getting a bunch of FileUtils.scala: not found: value os... is this assuming a certain Scala version? I'm on 2.12.13

Form these lines:

firrtl/build.sbt

Line 39 in de56a19

"com.lihaoyi" %% "os-lib" % "0.7.8",

firrtl/build.sc

Line 51 in de56a19

ivy"com.lihaoyi::os-lib:0.7.8",

I think os-lib is available in the latest SNAPSHOT(master), can you DM me your build flow?

[mwachs5]

I got past that by adding the com:lihayi library to my build, thanks! On to the next thing...

[sequencer]

I got past that by adding the com:lihayi library to my build, thanks! On to the next thing...

haha, I guess it blames to ivydependencies.json ;p