// checkInPackageBlock performs safety checks for renames of
// func/var/const/type objects in the package block.
func (r *renamer) checkInPackageBlock(from types.Object) {
// Check that there are no references to the name from another
// package if the renaming would make it unexported.
if ast.IsExported(from.Name()) && !ast.IsExported(r.to) {
for pkg, info := range r.packages {
if pkg == from.Pkg() {
continue
}
if id := someUse(info, from); id != nil &&
!r.checkExport(id, pkg, from) {
break
}
}
}
info := r.packages[from.Pkg()]
// Check that in the package block, "init" is a function, and never referenced.
if r.to == "init" {
kind := objectKind(from)
if kind == "func" {
// Reject if intra-package references to it exist.
for id, obj := range info.Uses {
if obj == from {
r.errorf(from.Pos(),
"renaming this func %q to %q would make it a package initializer",
from.Name(), r.to)
r.errorf(id.Pos(), "\tbut references to it exist")
break
}
}
} else {
r.errorf(from.Pos(), "you cannot have a %s at package level named %q",
kind, r.to)
}
}
// Check for conflicts between package block and all file blocks.
for _, f := range info.Files {
fileScope := info.Info.Scopes[f]
b, prev := fileScope.LookupParent(r.to, token.NoPos)
if b == fileScope {
r.errorf(from.Pos(), "renaming this %s %q to %q would conflict",
objectKind(from), from.Name(), r.to)
r.errorf(prev.Pos(), "\twith this %s",
objectKind(prev))
return // since checkInPackageBlock would report redundant errors
}
}
// Check for conflicts in lexical scope.
if from.Exported() {
for _, info := range r.packages {
r.checkInLexicalScope(from, info)
}
} else {
r.checkInLexicalScope(from, info)
}
}
// checkInPackageBlock performs safety checks for renames of
// func/var/const/type objects in the package block.
func (r *Unexporter) checkInPackageBlock(objsToUpdate map[types.Object]string, from types.Object, to string) {
// Check that there are no references to the name from another
// package if the renaming would make it unexported.
if ast.IsExported(from.Name()) && !ast.IsExported(to) {
for pkg, info := range r.packages {
if pkg == from.Pkg() {
continue
}
if id := someUse(info, from); id != nil &&
!r.checkExport(id, pkg, from, to) {
break
}
}
}
info := r.packages[from.Pkg()]
lexinfo := r.lexInfo(info)
// Check that in the package block, "init" is a function, and never referenced.
if to == "init" {
kind := objectKind(from)
if kind == "func" {
// Reject if intra-package references to it exist.
if refs := lexinfo.Refs[from]; len(refs) > 0 {
r.warn(from,
r.errorf(from.Pos(),
"renaming this func %q to %q would make it a package initializer",
from.Name(), to),
r.errorf(refs[0].Id.Pos(), "\tbut references to it exist"))
}
} else {
r.warn(from, r.errorf(from.Pos(), "you cannot have a %s at package level named %q",
kind, to))
}
}
// Check for conflicts between package block and all file blocks.
for _, f := range info.Files {
if prev, b := lexinfo.Blocks[f].Lookup(to); b == lexinfo.Blocks[f] {
r.warn(from,
r.errorf(from.Pos(), "renaming this %s %q to %q would conflict",
objectKind(from), from.Name(), to),
r.errorf(prev.Pos(), "\twith this %s",
objectKind(prev)))
return // since checkInPackageBlock would report redundant errors
}
}
// Check for conflicts in lexical scope.
if from.Exported() {
for _, info := range r.packages {
r.checkInLexicalScope(objsToUpdate, from, to, info)
}
} else {
r.checkInLexicalScope(objsToUpdate, from, to, info)
}
}
func (c *funcContext) objectName(o types.Object) string {
if isPkgLevel(o) {
c.p.dependencies[o] = true
if o.Pkg() != c.p.Pkg || (isVarOrConst(o) && o.Exported()) {
return c.pkgVar(o.Pkg()) + "." + o.Name()
}
}
name, ok := c.p.objectNames[o]
if !ok {
name = c.newVariableWithLevel(o.Name(), isPkgLevel(o))
c.p.objectNames[o] = name
}
if v, ok := o.(*types.Var); ok && c.p.escapingVars[v] {
return name + "[0]"
}
return name
}
func isExported(obj types.Object) bool {
// https://golang.org/ref/spec#Exported_identifiers
// An identifier is exported if both:
// the first character of the identifier's name is a Unicode upper case letter (Unicode class "Lu"); and
// the identifier is declared in the package block or it is a field name or method name.
// All other identifiers are not exported.
if !obj.Exported() {
// does not start with an upper case letter
return false
}
if v, ok := obj.(*types.Var); ok && v.IsField() {
// is a field name
return true
}
if sig, ok := obj.Type().(*types.Signature); ok && sig.Recv() != nil {
// is a method name
return true
}
// is declared in the package block
return obj.Parent() == obj.Pkg().Scope()
}
// Referrers reports all identifiers that resolve to the same object
// as the queried identifier, within any package in the analysis scope.
func referrers(q *Query) error {
lconf := loader.Config{Build: q.Build}
allowErrors(&lconf)
if _, err := importQueryPackage(q.Pos, &lconf); err != nil {
return err
}
var id *ast.Ident
var obj types.Object
var lprog *loader.Program
var pass2 bool
var qpos *queryPos
for {
// Load/parse/type-check the program.
var err error
lprog, err = lconf.Load()
if err != nil {
return err
}
q.Fset = lprog.Fset
qpos, err = parseQueryPos(lprog, q.Pos, false)
if err != nil {
return err
}
id, _ = qpos.path[0].(*ast.Ident)
if id == nil {
return fmt.Errorf("no identifier here")
}
obj = qpos.info.ObjectOf(id)
if obj == nil {
// Happens for y in "switch y := x.(type)",
// the package declaration,
// and unresolved identifiers.
if _, ok := qpos.path[1].(*ast.File); ok { // package decl?
pkg := qpos.info.Pkg
obj = types.NewPkgName(id.Pos(), pkg, pkg.Name(), pkg)
} else {
return fmt.Errorf("no object for identifier: %T", qpos.path[1])
}
}
if pass2 {
break
}
// If the identifier is exported, we must load all packages that
// depend transitively upon the package that defines it.
// Treat PkgNames as exported, even though they're lowercase.
if _, isPkg := obj.(*types.PkgName); !(isPkg || obj.Exported()) {
break // not exported
}
// Scan the workspace and build the import graph.
// Ignore broken packages.
_, rev, _ := importgraph.Build(q.Build)
// Re-load the larger program.
// Create a new file set so that ...
// External test packages are never imported,
// so they will never appear in the graph.
// (We must reset the Config here, not just reset the Fset field.)
lconf = loader.Config{
Fset: token.NewFileSet(),
Build: q.Build,
}
allowErrors(&lconf)
for path := range rev.Search(obj.Pkg().Path()) {
lconf.ImportWithTests(path)
}
pass2 = true
}
// Iterate over all go/types' Uses facts for the entire program.
var refs []*ast.Ident
for _, info := range lprog.AllPackages {
for id2, obj2 := range info.Uses {
if sameObj(obj, obj2) {
refs = append(refs, id2)
}
}
}
sort.Sort(byNamePos{q.Fset, refs})
q.result = &referrersResult{
qpos: qpos,
query: id,
obj: obj,
refs: refs,
}
return nil
}
