Support CallerArgumentExpression

[ijklam]

Description

Implements fsharp/fslang-suggestions#966

Checklist

• Test cases added
• Performance benchmarks added in case of performance changes
• Release notes entry updated:

[github-actions]

❗ Release notes required

@Tangent-90,

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Change path	Release notes path	Description
src/Compiler	docs/release-notes/.FSharp.Compiler.Service/9.0.200.md	No release notes found or release notes format is not correct

---

✅ Found changes and release notes in following paths:

Change path	Release notes path	Description
LanguageFeatures.fsi	docs/release-notes/.Language/preview.md

[ijklam]

Here I encounter a problem about #line. For example, the code is saved in D:\Program.fs:

#1 "C:\\Program.fs"
System.ArgumentNullException.ThrowIfNullOrWhiteSpace("   ")  // will failed to build

// And more complicated case, repeat the file name and line number
#1 "C:\\Program.fs"
System.ArgumentNullException.ThrowIfNullOrWhiteSpace("   ")  // will failed to build

So here I want to get the original range instead of a range modified by #line . Is there anybody know how to do it?

[brianrourkeboll]

I wonder whether it would be possible to use ISourceText.GetSubTextString instead of all of this. I think the ISourceText for a given file will usually already be cached when this functionality is needed.

I think in theory the source text is available on cenv.tcSink.CurrentSink.Value.CurrentSourceText.Value, but maybe there's a better way to get it, or a better way to bring it in scope for this change.

[ijklam]

It seems that this cannot work under dotnet fsi and under dotnet build. It is always None.

[brianrourkeboll]

Maybe it would make sense to pass it in, then, as is done when checking format strings:

fsharp/src/Compiler/Checking/NameResolution.fs

Lines 1777 to 1779 in 0a715a5

	type FormatStringCheckContext =
	{ SourceText: ISourceText
	LineStartPositions: int[] }

fsharp/src/Compiler/Checking/CheckFormatStrings.fs

Lines 67 to 73 in 0a715a5

	let makeFmts (context: FormatStringCheckContext) (fragRanges: range list) (fmt: string) =
	// Splits the string on interpolation holes based on fragment ranges.
	// Returns a list of tuples in the form of: offset * fragment as a string * original range of the fragment
	// where "offset" is the offset between beginning of the original range and where the string content begins
	let numFrags = fragRanges.Length
	let sourceText = context.SourceText

[brianrourkeboll]

Maybe it would make sense to pass it in, then, as is done when checking format strings:

I guess maybe that's the same source text as in the sink... But still, maybe there's somewhere else we could put it.