if slicesContains(pass.OtherFiles, filename) ||
		slicesContains(pass.IgnoredFiles, filename) {
		return nil
	}
	for _, f := range pass.Files {
		// TODO(adonovan): use go1.20 f.FileStart
		if pass.Fset.File(f.Pos()).Name() == filename {
			return nil
		}
	}
	return fmt.Errorf("Pass.ReadFile: %s is not among OtherFiles, IgnoredFiles, or names of Files", filename)
}

package being analyzed, and provides operations to the Run function for
reporting diagnostics and other information back to the driver.

	type Pass struct {
		Fset         *token.FileSet
		Files        []*ast.File
		OtherFiles   []string
		IgnoredFiles []string
		Pkg          *types.Package
		TypesInfo    *types.Info
		ResultOf     map[*Analyzer]interface{}
		Report       func(Diagnostic)
		...
	}

			for _, f := range a.FactTypes {
				factFilter[reflect.TypeOf(f)] = true
			}

			pass := &analysis.Pass{
				Analyzer:          a,
				Fset:              fset,
				Files:             files,
				OtherFiles:        cfg.NonGoFiles,
				IgnoredFiles:      cfg.IgnoredFiles,
				Pkg:               pkg,
				TypesInfo:         info,
				TypesSizes:        tc.Sizes,

	abiSuff      = re(`^(.+)<(ABI.+)>$`)
)

func run(pass *analysis.Pass) (interface{}, error) {
	// No work if no assembly files.
	var sfiles []string
	for _, fname := range pass.OtherFiles {
		if strings.HasSuffix(fname, ".s") {
			sfiles = append(sfiles, fname)
		}
	}
	if sfiles == nil {
		return nil, nil
	}

	// Gather declarations. knownFunc[name][arch] is func description.