[dsyme]

This fixes three debugging issues

• For tupled functions it's possible to break/step before the arguments have correct debug display
• Debug tip shows wrong value on variables with same name
• FSharp emitting incorrect sequence point in debug info

There were two other issues fixed along the way

• The body of a let rec did not have a sequence point placed. That is fixed.
• When partial applications were made, such as printfn "..." a b , the allocation of the format string was done prior to the printf. That could cause odd step-through behaviour.

The changes are

• Be more careful about using a FeeFee debug point at the prolog to a method while arguments are being unpacked. This was the cause of For tupled functions it's possible to break/step before the arguments have correct debug display  #92
• Be more careful about using a FeeFee point when local functions are being allocated. This was the cause of [From VSTS] FSharp emitting incorrect sequence point in debug info #3036
• Be more careful about emitting the "start scope" of a let-bound variable only just before the variable is actually assigned. This was the cause of Quick Watch shows wrong value on variables with same name #3141

Testing is mostly through codegen tests - nearly all will need to be updated because along the way a nop instruction has disappeared from the top of most methods, because of the fix to #92 . I've also updated TheBigFileOfDebugStepping.fsx with new examples and manually done step-through for the whole file.

[cartermp]

Oh wow, this is great!

[dsyme]

@cartermp You (or someone else) might want to step the TheBigFileOfDebugStepping.fsx on .NET Core, just to check things are ok. Also in VSCode/Ionide.

I compile using release\net40\bin\fsc.exe --optimize- --debug+ TheBigFileOfDebugStepping.fsx then run devenv /debugexe TheBigFileOfDebugStepping.exe

[dsyme]

A horrible number of test baselines needed updating about 150 files

[cartermp]

Ugh, I can't test anything. Nothing will build on my machine with { 15.3.3, VSSDK, Win10 SDK, F# support }, after a git clean -xdf even.

C:\repos\visualfsharp\packages\Microsoft.VSSDK.BuildTools.15.0.26201\tools\vssdk\Microsoft.VsSDK.targets(966,5): error : CreatePkgDef : error : ReflectionTypeLoadException: Unable to load one or more of the requested types. Retrieve t
he LoaderExceptions property for more information. [C:\repos\visualfsharp\vsintegration\src\FSharp.LanguageService\FSharp.LanguageService.fsproj]

[KevinRansom]

Nice ... you've been busy.

[cartermp]

Okay, I got it to build after uninstalling nightlies and using VS command prompt in admin mode. Not sure which of that fixed it. Argh. Anyways, I can test this this week

[dsyme]

@dotnet-bot test this

[dsyme]

Well, I updated about 250 code generation test files (and simplified the naming of some others).

I took a look through as many of these as I could and basically all seemed to be the 'nop' removal. For example this one clearly has had one opode removed.

It's possible that something is being hidden by such a large test update. But I think it's still ready for merge, there's not a l;ot more we can do here besides staring at the diffs and manual testing.

[dsyme]

@KevinRansom I think we may as well merge this - review welcome for the src\fsharp files

[KevinRansom]

I already looked, I forgot to approve ... sorry.

[dsyme]

@KevinRansom You did approve, I just didn't notice it