gopls/internal/analysis: noresultvalues diagnostic triggers "end > end of file + 1" bug (via telemetry)

[adonovan]

#!stacks
"bug.Reportf" && "cache.(*action).exec.func2:+78"

		if end > fileEnd+1 {
			if !fixed {
				bug.Reportf("end > end of file + 1")
			}
			end = fileEnd
		}

This stack lMZltw was reported by telemetry:

noresultvalues reports a diagnostic with an End position well beyond EOF:

			pass.Report(analysis.Diagnostic{
				Pos:     err.Pos,
				End:     analysisinternal.TypeErrorEndPos(pass.Fset, buf.Bytes(), err.Pos),
				Message: err.Msg,
				SuggestedFixes: []analysis.SuggestedFix{{
					Message: "Delete return values",
					TextEdits: []analysis.TextEdit{{
						Pos:     retStmt.Pos(),
						End:     retStmt.End(),
						NewText: []byte("return"),
					}},
				}},
			})

The file was not "fixed", i.e. it is unmodified parser output.

gopls/bug
golang.org/x/tools/gopls/internal/util/bug.report:+35
golang.org/x/tools/gopls/internal/util/bug.Reportf:+1
golang.org/x/tools/gopls/internal/cache.(*action).exec.func2:+78
golang.org/x/tools/gopls/internal/cache.toGobDiagnostic:+32
golang.org/x/tools/gopls/internal/cache.(*action).exec.func3:+1
golang.org/x/tools/gopls/internal/analysis/noresultvalues.run.func1:+25
golang.org/x/tools/go/ast/inspector.(*Inspector).Preorder:+11
golang.org/x/tools/gopls/internal/analysis/noresultvalues.run:+7
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:=65
golang.org/x/tools/gopls/internal/cache.execActions.func1:+2
runtime.goexit:+0

golang.org/x/tools/gopls@v0.16.0-pre.1 go1.22.4 darwin/arm64 vscode (1)

Issue created by golang.org/x/tools/gopls/internal/telemetry/cmd/stacks.
Dups: PFz3wQ uU3LXw

[gabyhelp]

Similar Issues

• x/tools/gopls: "internal error converting diagnostic" (bug reported by telemetry) #64547
• x/tools/gopls: off-by-one in diagnostic results? #35116
• x/tools/gopls: toGobDiagnostic bug reported by telemetry #65695
• x/tools/gopls: Analyze bug reported by telemetry #64238
• x/tools/gopls: out-of-bounds index in "stub methods" code action #64087
• x/tools/gopls: "could not compute pos to range for %v: %v" bug (reported by telemetry) #65960
• x/tools/gopls: span.FromUTF16Column should handle positions beyond end of line #31883
• x/tools/gopls: "internal error reading (shared cache|typerefs data)" bug report (via telemetry) #67433
• x/tools/gopls: diagnostic doesn't go away #54777
• x/tools/gopls: initial diagnostic run "overwrites" subsequent file-open diagnostics #36452

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

[adonovan]

This stack PFz3wQ was reported by telemetry:

• gopls/bug
• golang.org/x/tools/gopls/internal/util/bug.report:+35
• golang.org/x/tools/gopls/internal/util/bug.Reportf:+1
• golang.org/x/tools/gopls/internal/cache.(*action).exec.func2:+78
• golang.org/x/tools/gopls/internal/cache.toGobDiagnostic:+32
• golang.org/x/tools/gopls/internal/cache.(*action).exec.func3:+1
• golang.org/x/tools/gopls/internal/analysis/noresultvalues.run.func1:+25
• golang.org/x/tools/go/ast/inspector.(*Inspector).Preorder:+11
• golang.org/x/tools/gopls/internal/analysis/noresultvalues.run:+7
• 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/gopls@v0.16.2 go1.23.2 linux/amd64 other,vscode (1)
golang.org/x/tools/gopls@v0.16.2 go1.23.1 linux/amd64 vscode (1)

[adonovan]

This stack uU3LXw was reported by telemetry:

• gopls/bug
• golang.org/x/tools/gopls/internal/util/bug.report:+35
• golang.org/x/tools/gopls/internal/util/bug.Reportf:+1
• golang.org/x/tools/gopls/internal/cache.(*action).exec.func2:+78
• golang.org/x/tools/gopls/internal/cache.toGobDiagnostic:+32
• golang.org/x/tools/gopls/internal/cache.(*action).exec.func3:+1
• golang.org/x/tools/gopls/internal/analysis/nonewvars.run.func1:+29
• golang.org/x/tools/go/ast/inspector.(*Inspector).Preorder:+11
• golang.org/x/tools/gopls/internal/analysis/nonewvars.run:+7
• 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/gopls@v0.16.2 go1.23.0 linux/amd64 vscode (1)

[findleyr]

This is probably a bit gnarly to track down, though surely it's a go/parser bug. Bumping to v0.18, when hopefully we can fix go/parser.