Golang Var.Anonymous方法代码示例

func (p *exporter) field(f *types.Var) {
	// anonymous fields have "" name
	name := ""
	if !f.Anonymous() {
		name = f.Name()
	}

	// qualifiedName will always emit the field package for
	// anonymous fields because "" is not an exported name.
	p.qualifiedName(f.Pkg(), name)
	p.typ(f.Type())
}

// checkStructField checks that the field renaming will not cause
// conflicts at its declaration, or ambiguity or changes to any selection.
func (e *Export) checkStructField(from *types.Var, to string) {
	// Check that the struct declaration is free of field conflicts,
	// and field/method conflicts.
	t := getEnclosingStruct(from)
	if t != t.Underlying() {
		// This struct is also a named type.
		// We must check for direct (non-promoted) field/field
		// and method/field conflicts.
		_, indices, _ := types.LookupFieldOrMethod(t, true, e.u.pkgInfo.Pkg, to)
		if len(indices) == 1 {
			e.Conflicting = true
			return
		}
	} else {
		// This struct is not a named type.
		// We need only check for direct (non-promoted) field/field conflicts.
		T := t.Underlying().(*types.Struct)
		for i := 0; i < T.NumFields(); i++ {
			if prev := T.Field(i); prev.Name() == to {
				e.Conflicting = true
				return
			}
		}
	}

	// Renaming an anonymous field requires renaming the type too. e.g.
	// 	print(s.T)       // if we rename T to U,
	// 	type T int       // this and
	// 	var s struct {T} // this must change too.
	if from.Anonymous() {
		if named, ok := from.Type().(*types.Named); ok {
			e.check(named.Obj(), to)
		} else if named, ok := deref(from.Type()).(*types.Named); ok {
			e.check(named.Obj(), to)
		}
	}

	// Check integrity of existing (field and method) selections.
	e.checkSelections(from, to)
}

// checkStructField checks that the field renaming will not cause
// conflicts at its declaration, or ambiguity or changes to any selection.
func (r *Unexporter) checkStructField(objsToUpdate map[types.Object]string, from *types.Var, to string) {
	// Check that the struct declaration is free of field conflicts,
	// and field/method conflicts.

	// go/types offers no easy way to get from a field (or interface
	// method) to its declaring struct (or interface), so we must
	// ascend the AST.
	info, path, _ := r.iprog.PathEnclosingInterval(from.Pos(), from.Pos())
	// path matches this pattern:
	// [Ident SelectorExpr? StarExpr? Field FieldList StructType ParenExpr* ... File]

	// Ascend to FieldList.
	var i int
	for {
		if _, ok := path[i].(*ast.FieldList); ok {
			break
		}
		i++
	}
	i++
	tStruct := path[i].(*ast.StructType)
	i++
	// Ascend past parens (unlikely).
	for {
		_, ok := path[i].(*ast.ParenExpr)
		if !ok {
			break
		}
		i++
	}
	if spec, ok := path[i].(*ast.TypeSpec); ok {
		// This struct is also a named type.
		// We must check for direct (non-promoted) field/field
		// and method/field conflicts.
		named := info.Defs[spec.Name].Type()
		prev, indices, _ := types.LookupFieldOrMethod(named, true, info.Pkg, to)
		if len(indices) == 1 {
			r.warn(from,
				r.errorf(from.Pos(), "renaming this field %q to %q",
					from.Name(), to),
				r.errorf(prev.Pos(), "\twould conflict with this %s",
					objectKind(prev)))
			return // skip checkSelections to avoid redundant errors
		}
	} else {
		// This struct is not a named type.
		// We need only check for direct (non-promoted) field/field conflicts.
		t := info.Types[tStruct].Type.Underlying().(*types.Struct)
		for i := 0; i < t.NumFields(); i++ {
			if prev := t.Field(i); prev.Name() == to {
				r.warn(from,
					r.errorf(from.Pos(), "renaming this field %q to %q",
						from.Name(), to),
					r.errorf(prev.Pos(), "\twould conflict with this field"))
				return // skip checkSelections to avoid redundant errors
			}
		}
	}

	// Renaming an anonymous field requires renaming the type too. e.g.
	// 	print(s.T)       // if we rename T to U,
	// 	type T int       // this and
	// 	var s struct {T} // this must change too.
	if from.Anonymous() {
		if named, ok := from.Type().(*types.Named); ok {
			r.check(objsToUpdate, named.Obj(), to)
		} else if named, ok := deref(from.Type()).(*types.Named); ok {
			r.check(objsToUpdate, named.Obj(), to)
		}
	}

	// Check integrity of existing (field and method) selections.
	r.checkSelections(objsToUpdate, from, to)
}