Add support for configurable hashing for source checksums

[KevinRansom]

Internal thread:

From: Mike Lai
Sent: Monday, May 23, 2016 3:44 PM
To: Kevin Ransom [email protected]
Cc: Michael Fanning (DEVDIV) [email protected]; Tomas Matousek [email protected]
Subject: RE: F# Compiler (fsc.exe)

I see, Kevin. Would you mind to consider our request to make SHA256 as one of available sections, please?

All the following compilers support SHA256 today.

Thanks
Mike

• cl.exe /ZH:SHA_256
• ml.exe /ZH:SHA_256
• ml64.exe /ZH:SHA_256
• armasm.exe -gh:SHA_256
• armasm64.exe -gh:SHA_256
• csc.exe /checksumalgorithm:SHA256

From: Kevin Ransom
Sent: Monday, May 23, 2016 3:40 PM
To: Mike Lai [email protected]
Cc: Michael Fanning (DEVDIV) [email protected]; Tomas Matousek [email protected]
Subject: Re: F# Compiler (fsc.exe)

Not selectable and MD5

https://github.com/Microsoft/visualfsharp/blob/master/src/absil/ilwritepdb.fs#L126

Kevin
From: Mike Lai [email protected]
Date: Monday, May 23, 2016 at 3:30 PM
To: Kevin Ransom [email protected]
Cc: "Michael Fanning (DEVDIV)" [email protected], Tomas Matousek [email protected]
Subject: RE: F# Compiler (fsc.exe)

Hi Kevin -- It is about the hashes of compiled source files being written by the compiler to the pdb files?

What kind (SHA1 or SHA256) of hashes does the F# Compiler (fsc.exe) put in the pdb files ?

CSC.exe can put either based on the “/checksumalgorithm:” switch. I am wondering if fsc.exe can support the same please?

Thanks

Mike

From: Kevin Ransom
Sent: Monday, May 23, 2016 3:26 PM
To: Mike Lai [email protected]
Cc: Michael Fanning (DEVDIV) [email protected]; Tomas Matousek [email protected]
Subject: Re: F# Compiler (fsc.exe)

Hey Mike,

Can you let me know what this is about?

Thanks

Kevin

From: Mike Lai [email protected]
Date: Monday, May 23, 2016 at 2:10 PM
To: Kevin Ransom [email protected]
Cc: "Michael Fanning (DEVDIV)" [email protected], Tomas Matousek [email protected]
Subject: RE: F# Compiler (fsc.exe)

Thanks Tomas for the introduction! Hi Kevin – please find enclosed the background information on why we are driving this. Please feel free to let me know if you have additional questions.

Thanks
Mike

From: Tomas Matousek
Sent: Monday, May 23, 2016 1:56 PM
To: Kevin Ransom [email protected]
Cc: Michael Fanning (DEVDIV) [email protected]; Mike Lai [email protected]
Subject: RE: F# Compiler (fsc.exe)

Kevin, F# needs “/checksumalgorithm:” command line switch to set the algorithm to calculate document hash saved to PDB.
Mike is driving the effort to get the option to all compilers.

Thanks,
Tomas

[tmat]

This switch determines the algorithm used to calculate source file checksums stored in PDB.

The corresponding MSBuild task property is ChecksumAlgorithm.

Supported values should include SHA1 and SHA256. See Roslyn for details:

http://source.roslyn.io/#Microsoft.CodeAnalysis.CSharp/CommandLine/CSharpCommandLineParser.cs,286

The default in Roslyn is currently SHA1. We are considering switching to SHA256:

dotnet/roslyn#24820

[tmat]

@KevinRansom Can we do this work for 15.7?

[KevinRansom]

@tmat I will add it to my list

[tmat]

The default in Roslyn is currently SHA1. We are considering switching to SHA256.

We did switch Roslyn to SHA256. F# should also default to SHA256.