log.Fatalf("pkg %q, dir %q: ScanDir: %v", name, dir, err)
	}

	// Save tags list first time we see a directory.
	if usePkgCache {
		if _, ok := pkgTags[dir]; !ok {
			pkgTags[dir] = info.AllTags
			key = tagKey(dir, context, info.AllTags)
		}
	}

	filenames := append(append([]string{}, info.GoFiles...), info.CgoFiles...)

	// Parse package files.
	var files []*ast.File
	for _, file := range filenames {

pkg go/ast, type TypeAssertExpr struct, Lparen token.Pos
pkg go/ast, type TypeAssertExpr struct, Rparen token.Pos
pkg go/build, method (*Context) MatchFile(string, string) (bool, error)
pkg go/build, type Package struct, AllTags []string
pkg go/build, type Package struct, CXXFiles []string
pkg go/build, type Package struct, CgoCPPFLAGS []string
pkg go/build, type Package struct, CgoCXXFLAGS []string
pkg go/build, type Package struct, ConflictDir string