x/tools/gopls: "diagnostic location is not among files of package: %s" assertion is unjustified for Diagnostic.Related

[adonovan]

#!stacks
"bug.Errorf" && "cache.(*action).exec.func2:+48"

Issue created by stacks.

if mapper == nil {
			// The start position was not among the package's parsed
			// Go files, indicating that the analyzer added new files
			// to the FileSet.
			//
			// For example, the cgocall analyzer re-parses and
			// type-checks some of the files in a special environment;
			// and asmdecl and other low-level runtime analyzers call
			// ReadFile to parse non-Go files.
			// (This is a supported feature, documented at go/analysis.)
			//
			// In principle these files could be:
			//
			// - OtherFiles (non-Go files such as asm).
			//   However, we set Pass.OtherFiles=[] because
			//   gopls won't service "diagnose" requests
			//   for non-Go files, so there's no point
			//   reporting diagnostics in them.
			//
			// - IgnoredFiles (files tagged for other configs).
			//   However, we set Pass.IgnoredFiles=[] because,
			//   in most cases, zero-config gopls should create
			//   another view that covers these files.
			//
			// - Referents of //line directives, as in cgo packages.
			//   The file names in this case are not known a priori.
			//   gopls generally tries to avoid honoring line directives,
			//   but analyzers such as cgocall may honor them.
			//
			// In short, it's unclear how this can be reached
			// other than due to an analyzer bug.
			return protocol.Location{}, bug.Errorf("diagnostic location is not among files of package: %s", tokFile.Name())
}

The analyzer that reported the diagnostic is staticcheck's SA4023, but all its calls to Report look fine.

This stack dlmz3w was reported by telemetry:

• gopls/bug
• golang.org/x/tools/gopls/internal/util/bug.report:+35
• golang.org/x/tools/gopls/internal/util/bug.Errorf:+2
• golang.org/x/tools/gopls/internal/cache.(*action).exec.func2:+48
• golang.org/x/tools/gopls/internal/cache.toGobDiagnostic:+22
• golang.org/x/tools/gopls/internal/cache.(*action).exec.func3:+1
• honnef.co/go/tools/analysis/report.Report:+40
• honnef.co/go/tools/staticcheck/sa4023.run:+100
• golang.org/x/tools/gopls/internal/cache.(*action).exec.func7:+31
• golang.org/x/tools/gopls/internal/cache.(*action).exec:+277
• golang.org/x/tools/gopls/internal/cache.execActions.func1.1:+2
• sync.(*Once).doSlow:+5
• sync.(*Once).Do:=67
• golang.org/x/tools/gopls/internal/cache.execActions.func1:+2
• runtime.goexit:+0

golang.org/x/tools/[email protected] go1.23.2 linux/amd64 vscode (1)

Dups: ARI9LQ xuqd0A UM4FBg

[gabyhelp]

Related Issues

• x/tools/gopls: "internal error converting diagnostic" (bug reported by telemetry) #64547 (closed)
• x/tools/gopls: cgocall analyzer: "token.Pos not within package" bug (reported by telemetry) #66911 (closed)
• x/tools/gopls: toGobDiagnostic bug reported by telemetry #65695 (closed)
• x/tools/gopls: Analyze bug reported by telemetry #64238 (closed)
• x/tools/gopls: bug in analysis importer reported by telemetry #64236 (closed)
• x/tools/gopls: "could not locate file for primary type checker error" bug reported by telemetry #66765
• x/tools/gopls/internal/regtest/diagnostics: TestErrorsThatPreventAnalysis failures #58899 (closed)
• x/tools/gopls: strange output with gopls >= 0.3.0, no actual errors detected #37046 (closed)
• x/tools/gopls: crash when primary diagnostics have invalid positions #66731 (closed)
• x/tools/gopls: initial diagnostic run "overwrites" subsequent file-open diagnostics #36452 (closed)

_{(Emoji vote if this was helpful or unhelpful; more detailed feedback welcome in this discussion.)}

[adonovan]

This stack ARI9LQ was reported by telemetry:

• gopls/bug
• golang.org/x/tools/gopls/internal/util/bug.report:+35
• golang.org/x/tools/gopls/internal/util/bug.Errorf:+2
• golang.org/x/tools/gopls/internal/cache.(*action).exec.func2:+48
• golang.org/x/tools/gopls/internal/cache.toGobDiagnostic:+22
• golang.org/x/tools/gopls/internal/cache.(*action).exec.func3:+1
• honnef.co/go/tools/analysis/report.Report:+40
• honnef.co/go/tools/staticcheck/sa4023.run:+100
• golang.org/x/tools/gopls/internal/cache.(*action).exec.func7:+31
• golang.org/x/tools/gopls/internal/cache.(*action).exec:+277
• golang.org/x/tools/gopls/internal/cache.execActions.func1.1:+2
• sync.(*Once).doSlow:+5
• sync.(*Once).Do:=69
• golang.org/x/tools/gopls/internal/cache.execActions.func1:+2
• runtime.goexit:+0

golang.org/x/tools/[email protected] go1.24.0 darwin/arm64 neovim (1)

[adonovan]

This stack xuqd0A was reported by telemetry:

• gopls/bug
• golang.org/x/tools/gopls/internal/util/bug.report:+35
• golang.org/x/tools/gopls/internal/util/bug.Errorf:+2
• golang.org/x/tools/gopls/internal/cache.(*action).exec.func2:+48
• golang.org/x/tools/gopls/internal/cache.toGobDiagnostic:+22
• golang.org/x/tools/gopls/internal/cache.(*action).exec.func3:+6
• honnef.co/go/tools/analysis/report.Report:+40
• honnef.co/go/tools/staticcheck/sa4023.run:+100
• golang.org/x/tools/gopls/internal/cache.(*action).exec.func7:+31
• golang.org/x/tools/gopls/internal/cache.(*action).exec:+282
• golang.org/x/tools/gopls/internal/cache.execActions.func1.1:+2
• sync.(*Once).doSlow:+5
• sync.(*Once).Do:=69
• golang.org/x/tools/gopls/internal/cache.execActions.func1:+2
• runtime.goexit:+0

golang.org/x/tools/[email protected] go1.24.0 darwin/arm64 neovim (1)

[adonovan]

This stack UM4FBg was reported by telemetry:

• gopls/bug
• golang.org/x/tools/gopls/internal/util/bug.report:+35
• golang.org/x/tools/gopls/internal/util/bug.Errorf:+2
• golang.org/x/tools/gopls/internal/cache.(*action).exec.func2:+48
• golang.org/x/tools/gopls/internal/cache.toGobDiagnostic:+22
• golang.org/x/tools/gopls/internal/cache.(*action).exec.func3:+6
• honnef.co/go/tools/analysis/report.Report:+40
• honnef.co/go/tools/staticcheck/sa4023.run:+100
• golang.org/x/tools/gopls/internal/cache.(*action).exec.func7:+31
• golang.org/x/tools/gopls/internal/cache.(*action).exec:+282
• golang.org/x/tools/gopls/internal/cache.execActions.func1.1:+2
• sync.(*Once).doSlow:+5
• sync.(*Once).Do:=67
• golang.org/x/tools/gopls/internal/cache.execActions.func1:+2
• runtime.goexit:+0

golang.org/x/tools/[email protected] go1.23.6 darwin/arm64 vscode (2)
golang.org/x/tools/[email protected] go1.23.5 darwin/arm64 other (2)

[adonovan]

Ah! The stack frame in toGobDiagnostic clearly implicates the Related field of Diagnostic, and sure enough, SA4023 supplies Related information, one element of which uses the position of a *types.Func from a dependency, so it is unsurprising that the assertion fails to find the location among the source files of the current package. I think SA4023 is unimpeachable: the go/analysis API doesn't say Related positions must be in the current package (as it does for SuggestedFixes), and it is natural that they would not be. So I think the assertion in gopls is simply wrong.

[gopherbot]

Change https://go.dev/cl/667517 mentions this issue: gopls/internal/cache: fix bug in toGobDiagnostic(Related)