diff options
Diffstat (limited to 'src/go/types/object.go')
| -rw-r--r-- | src/go/types/object.go | 105 |
1 files changed, 56 insertions, 49 deletions
diff --git a/src/go/types/object.go b/src/go/types/object.go index 6c0c5c4a24..3c44348696 100644 --- a/src/go/types/object.go +++ b/src/go/types/object.go @@ -25,7 +25,7 @@ type Object interface { Name() string // package local object name Type() Type // object type Exported() bool // reports whether the name starts with a capital letter - Id() string // object id (see Id below) + Id() string // object name if exported, qualified name if not exported (see func Id) // String returns a human-readable string of the object. String() string @@ -64,15 +64,10 @@ func Id(pkg *Package, name string) string { // inside a package and outside a package - which breaks some // tests) path := "_" - // TODO(gri): shouldn't !ast.IsExported(name) => pkg != nil be an precondition? - // if pkg == nil { - // panic("nil package in lookup of unexported name") - // } - if pkg != nil { + // pkg is nil for objects in Universe scope and possibly types + // introduced via Eval (see also comment in object.sameId) + if pkg != nil && pkg.path != "" { path = pkg.path - if path == "" { - path = "_" - } } return path + "." + name } @@ -154,7 +149,7 @@ func NewConst(pos token.Pos, pkg *Package, name string, typ Type, val constant.V func (obj *Const) Val() constant.Value { return obj.val } func (*Const) isDependency() {} // a constant may be a dependency of an initialization expression -// A TypeName represents a declared type. +// A TypeName represents a name for a (named or alias) type. type TypeName struct { object } @@ -163,6 +158,26 @@ func NewTypeName(pos token.Pos, pkg *Package, name string, typ Type) *TypeName { return &TypeName{object{nil, pos, pkg, name, typ, 0, token.NoPos}} } +// IsAlias reports whether obj is an alias name for a type. +func (obj *TypeName) IsAlias() bool { + switch t := obj.typ.(type) { + case nil: + return false + case *Basic: + // Any user-defined type name for a basic type is an alias for a + // basic type (because basic types are pre-declared in the Universe + // scope, outside any package scope), and so is any type name with + // a different name than the name of the basic type it refers to. + // Additionaly, we need to look for "byte" and "rune" because they + // are aliases but have the same names (for better error messages). + return obj.pkg != nil || t.name != obj.name || t == universeByte || t == universeRune + case *Named: + return obj != t.obj + default: + return true + } +} + // A Variable represents a declared variable (including function parameters and results, and struct fields). type Var struct { object @@ -215,28 +230,6 @@ func (obj *Func) FullName() string { func (obj *Func) Scope() *Scope { return obj.typ.(*Signature).scope } func (*Func) isDependency() {} // a function may be a dependency of an initialization expression -// An Alias represents a declared alias. -type disabledAlias struct { - object - orig Object // aliased constant, type, variable, or function; never an alias - kind token.Token // token.CONST, token.TYPE, token.VAR, or token.FUNC (only needed during resolve phase) -} - -func disabledNewAlias(pos token.Pos, pkg *Package, name string, orig Object) *disabledAlias { - var typ Type = Typ[Invalid] - if orig != nil { - typ = orig.Type() - } - // No need to set a valid Alias.kind - that field is only used during identifier - // resolution (1st type-checker pass). We could store the field outside but it's - // easier to keep it here. - return &disabledAlias{object{nil, pos, pkg, name, typ, 0, token.NoPos}, orig, token.ILLEGAL} -} - -// Orig returns the aliased object, or nil if there was an error. -// The returned object is never an Alias. -func (obj *disabledAlias) disabledOrig() Object { return obj.orig } - // A Label represents a declared label. type Label struct { object @@ -264,7 +257,9 @@ type Nil struct { } func writeObject(buf *bytes.Buffer, obj Object, qf Qualifier) { + var tname *TypeName typ := obj.Type() + switch obj := obj.(type) { case *PkgName: fmt.Fprintf(buf, "package %s", obj.Name()) @@ -277,8 +272,8 @@ func writeObject(buf *bytes.Buffer, obj Object, qf Qualifier) { buf.WriteString("const") case *TypeName: + tname = obj buf.WriteString("type") - typ = typ.Underlying() case *Var: if obj.isField { @@ -295,10 +290,6 @@ func writeObject(buf *bytes.Buffer, obj Object, qf Qualifier) { } return - // Alias-related code. Keep for now. - // case *Alias: - // buf.WriteString("alias") - case *Label: buf.WriteString("label") typ = nil @@ -322,10 +313,27 @@ func writeObject(buf *bytes.Buffer, obj Object, qf Qualifier) { writePackage(buf, obj.Pkg(), qf) } buf.WriteString(obj.Name()) - if typ != nil { - buf.WriteByte(' ') - WriteType(buf, typ, qf) + + if typ == nil { + return + } + + if tname != nil { + // We have a type object: Don't print anything more for + // basic types since there's no more information (names + // are the same; see also comment in TypeName.IsAlias). + if _, ok := typ.(*Basic); ok { + return + } + if tname.IsAlias() { + buf.WriteString(" =") + } else { + typ = typ.Underlying() + } } + + buf.WriteByte(' ') + WriteType(buf, typ, qf) } func writePackage(buf *bytes.Buffer, pkg *Package, qf Qualifier) { @@ -353,15 +361,14 @@ func ObjectString(obj Object, qf Qualifier) string { return buf.String() } -func (obj *PkgName) String() string { return ObjectString(obj, nil) } -func (obj *Const) String() string { return ObjectString(obj, nil) } -func (obj *TypeName) String() string { return ObjectString(obj, nil) } -func (obj *Var) String() string { return ObjectString(obj, nil) } -func (obj *Func) String() string { return ObjectString(obj, nil) } -func (obj *disabledAlias) String() string { return ObjectString(obj, nil) } -func (obj *Label) String() string { return ObjectString(obj, nil) } -func (obj *Builtin) String() string { return ObjectString(obj, nil) } -func (obj *Nil) String() string { return ObjectString(obj, nil) } +func (obj *PkgName) String() string { return ObjectString(obj, nil) } +func (obj *Const) String() string { return ObjectString(obj, nil) } +func (obj *TypeName) String() string { return ObjectString(obj, nil) } +func (obj *Var) String() string { return ObjectString(obj, nil) } +func (obj *Func) String() string { return ObjectString(obj, nil) } +func (obj *Label) String() string { return ObjectString(obj, nil) } +func (obj *Builtin) String() string { return ObjectString(obj, nil) } +func (obj *Nil) String() string { return ObjectString(obj, nil) } func writeFuncName(buf *bytes.Buffer, f *Func, qf Qualifier) { if f.typ != nil { |