Fix ProjectCracker, optimize Filename.checkPathForIllegalChars

[vasily-kirichenko]

This function popped up in a profiler as one of hot paths. With this PR it disappears.

Path.GetInvalidPathChars() returns 36 chars and checking, say, 200 chars path, means 7200 array accesses and char comparisons. It seems this function is called very often.

[dsyme]

CI is failing because on .NET Core 1.0 we have

error FS0039: The field, constructor or member 'InvariantCultureIgnoreCase' is not defined

[vasily-kirichenko]

@dsyme Thanks!

[dsyme]

Hmmm On both Travis and AppVeyor:

Errors and Failures:
1) Test Failure : FSharp.Compiler.Service.Tests.ExprTests.Check use of type provider that provides calls to F# code
     Expected: 0
Actual: 3
  Expected: 0
  But was:  3

at FsUnit.shouldEqual[a] (a x, a y) <0x40e11900 + 0x0018b> in <filename unknown>:0
at FSharp.Compiler.Service.Tests.ExprTests.Check use of type provider that provides calls to F# code () <0x40324800 + 0x001c8> in <filename unknown>:0

[vasily-kirichenko]

Yeah, same failure on my machine...

[vasily-kirichenko]

So, ProjectFileNames and OtherOptions are in a mess. Before this PR ProjectFileNames was always empty and files names were in OtherOptions. And this worked somehow. I thought the proper way was to copy files names to ProjectFileNames from OtherOptions. But it messed things up since some code combines files names from those two lists. So, in the last commit I removed file names from OtherOptions, but it seems some other code uses OtherOptions and ignores ProjectFileNames :(

[vasily-kirichenko]

OK, I fixed the tests according to this behavior:

• source files go to ProjectFileNames only

[dsyme]

@vasily-kirichenko We should really merge the perf fix into Microsoft\visuafsharp too

[dsyme]

@vasily-kirichenko Thanks for the contribution!

[vasily-kirichenko]

@dsyme I ported the perf fix to visualfsharp repo and tested it on FCS project. Absolutely no improvements: 43 seconds on F# 4.0/4.1(master)/this perf fix. So I don't think it's worth to make this change in VFT.

[dsyme]

@vasily-kirichenko It might be that the fix applies primarily in the IDE tools - endless rechecking of fie names while preparing project options or doing incremental building. So perhaps the fix would apply specifically to the Visual F# IDE Tools. Anyway, it's ok - we can back port at some point, or perhaps we eventually work out how to merge repos.

[vasily-kirichenko]

Ah, I see. It's very easy to port it, so I'll make a PR in a minute or two.

[vasily-kirichenko]

dotnet/fsharp#1662