Signature data embedded in executable contains absolute source file path

[marklam]

The FSharpSignatureData resource embedded in the assembly contains absolute paths to the source files. This could include a user's real name etc.
I know this info is in the pdb, but shipping that with an executable is optional.
Executables produced from C# compiler don't contain file paths

Repro steps

Provide the steps required to reproduce the problem

1. Create a simple test.fs containing, say, let main argv = 1
2. fsc test.fs
3. strings test.exe
4. observe the full path to test.fs

Expected behavior

No source paths in the exe

Actual behavior

Absolute paths are embedded in the FSharpSignatureData resource

Known workarounds

Provide a description of any known workarounds.

Related information

Provide any related information

• Windows
• Microsoft (R) F# Compiler version 10.1.0 for F# 4.1
• .NET Runtime

[dsyme]

I believe this is the only place where the file names are stored:

• https://github.com/Microsoft/visualfsharp/blob/master/src/fsharp/TastPickle.fs#L1225

Before we just set this to "null", I should add that these file names are utilised by the F# IDE Tools to allow goto-definition and other things to work when

1. in-memory cross-project references are off and
2. you're referencing DLL components compiled on your machine.

This means go-to-definition will start failing for these cases if the file name information is just removed.

Alternatives might be

1. add a compiler option to suppress the generation of this information
2. add a compiler option to opt-in to include this information which is set when compiling from visual studio, or only set for Debug code
3. ??

[cartermp]

or only set for Debug code

Seems like the right call to me. Though we'll also want to make sure this doesn't negatively affect other editors (@auduchinok / @Krzysztof-Cieslak / @nosami FYI)

[dsyme]

or only set for Debug code

I think it would be really odd if GTD only worked across compiled assembly boundaries for Debug mode.... No other design-time tooling depends on this like this....

Though we'll also want to make sure this doesn't negatively affect other editors (@auduchinok / @Krzysztof-Cieslak / @nosami FYI)

I think it would.

[nosami]

VSMac can't turn off in-memory cross-project references. I would like to add this feature soon though.

[cartermp]

Hmmm. Well I think that from a tooling perspective there's no issue in having this info. What I think I'd prefer is a way to specify a default where this info is not present when building, and have things like design-time builds kick with that feature turned on.

[cartermp]

Here's what should happen:

1. Ensure that in release builds with the F# compiler, this is OFF by default.
2. In a tooling environment, this is ON by default.
3. Tools can detect when this is off and can offer to turn them on somehow.
4. Docs, etc. so that people know about the switch and can configure it for their environments.

I've labeled this as Urgency-Soon for now, but this is arguably Urgency-Now.

[0x53A]

Are you sure the c# compiler doesn't embed any absolute paths?

As far as I know the exe contains an absolute path to the pdb, unless you specifically set a few flags.

Edit: this is built with VS2017, C# dll, all options the default ones:

[marklam]

For a file test.cs, containing
class test { public static int Main(string[] args) { return 1; } }
Compile with csc test.cs
Opening test.exe in the binary editor shows no pathnames.

[0x53A]

yes, F# is a little bit worse. C# only embeds the absolute path if you generate a pdb, F# does it always.

You can try it with -pdb, then you should also see a path in C#. (-pdb is the default for a csproj)

I see value in having a way to suppress this (mostly for deterministic builds), but I don't think it should be enabled by default (even in release) if tooling suffers.

Edit:

C# allows you to map paths with -pathmap.

I edited my csproj and added <PathMap>C:\temp\KoalaTest=/</PathMap>.

Result:

So instead of blindly and in a hurry nulling out the value, please consider implementing the proper c# solution

[saul]

Linking #3812

[NinoFloris]

@saul I think F# should do deterministic paths by default when compiling with pdb, like C#. Is PathMap implementation the first step towards doing that or, should it be a native compiler feature?

[7sharp9]

I just looked in a release build and found this and others:

...
Map`2�TypeKindTypeResolvergetShortName�fullName	allScopes�seq`1
discoverTypes	ProtoFile�file
resolveScalar�option`1�_arg1
ptypeToString�resolveNonScalar
targetType�resolveresolvePTypeA/Users/dave.thomas/Documents/GitHub/falanx/Falanx.Proto.Generator

[NinoFloris]

Yeah it's everywhere in F# ecosystem, taskbuilder, saturn, giraffe all have (fun localized) user paths in there.

[cartermp]

Re-opening as this is not resolved in VS