add support for response file to fsc

[enricosada]

like roslyn. it's not because is roslyn, i think is useful

add @file argument to fsc

ref https://msdn.microsoft.com/en-us/library/8a1fs1tb.aspx

Long story short:

A file that lists compiler options or source code files to compile, instead of pass compiler arguments.

Goodies:

• Response files can have comments that begin with the # symbol.
• Combine multiple options. @file1.rsp @file2.rsp
• command line arguments can override previously listed options in response files.
• options in a response file will override options listed previously on the command line or in other response files

it's nice to have a base configuration, and two files, for example debug, test or perf as additional
more easy to track in source control ( it's a text file ) instead of concat argument list in script

[mexx]

👍

[KevinRansom]

Yes, this is a long time missing feature from F#, I have been figuring I would add it at some point, however, nothing fails to work because it is missing, so it has seemed like a very low priority feature to me.
If we do this, we should also consider adding response files for FSI.

I would certainly eagerly consider accepting a PR for this feature.

[enricosada]

i'll try to add it, it's really useful for dotnet cli development.

About this feature, @ is really wierd, it's like a special case of source file.
Should we use @ or a normal (short) argument like --rsp for consistency ? /cc @dsyme

I'll start with @, is not difficult to change after it's done

[smoothdeveloper]

I've encountered response files in the past and it was always using @ prefix, though I don't remember which compiler it was.

https://gcc.gnu.org/wiki/Response_Files

I'd vouch to keep the same convention as others compilers, especially if roslyn uses the same.

[enricosada]

ah nice @smoothdeveloper , good that is a shared command line option, thx for feedback

llvm too http://llvm.org/docs/CommandLine.html#response-files nice.

no more open questions so 😄

[dsyme]

Fixed in #831