|
@@ -1,762 +0,0 @@
|
|
-// Copyright 2018 The Go Authors. All rights reserved.
|
|
|
|
-// Use of this source code is governed by a BSD-style
|
|
|
|
-// license that can be found in the LICENSE file.
|
|
|
|
-
|
|
|
|
-// Package objectpath defines a naming scheme for types.Objects
|
|
|
|
-// (that is, named entities in Go programs) relative to their enclosing
|
|
|
|
-// package.
|
|
|
|
-//
|
|
|
|
-// Type-checker objects are canonical, so they are usually identified by
|
|
|
|
-// their address in memory (a pointer), but a pointer has meaning only
|
|
|
|
-// within one address space. By contrast, objectpath names allow the
|
|
|
|
-// identity of an object to be sent from one program to another,
|
|
|
|
-// establishing a correspondence between types.Object variables that are
|
|
|
|
-// distinct but logically equivalent.
|
|
|
|
-//
|
|
|
|
-// A single object may have multiple paths. In this example,
|
|
|
|
-//
|
|
|
|
-// type A struct{ X int }
|
|
|
|
-// type B A
|
|
|
|
-//
|
|
|
|
-// the field X has two paths due to its membership of both A and B.
|
|
|
|
-// The For(obj) function always returns one of these paths, arbitrarily
|
|
|
|
-// but consistently.
|
|
|
|
-package objectpath
|
|
|
|
-
|
|
|
|
-import (
|
|
|
|
- "fmt"
|
|
|
|
- "go/types"
|
|
|
|
- "sort"
|
|
|
|
- "strconv"
|
|
|
|
- "strings"
|
|
|
|
-
|
|
|
|
- "golang.org/x/tools/internal/typeparams"
|
|
|
|
-
|
|
|
|
- _ "unsafe" // for go:linkname
|
|
|
|
-)
|
|
|
|
-
|
|
|
|
-// A Path is an opaque name that identifies a types.Object
|
|
|
|
-// relative to its package. Conceptually, the name consists of a
|
|
|
|
-// sequence of destructuring operations applied to the package scope
|
|
|
|
-// to obtain the original object.
|
|
|
|
-// The name does not include the package itself.
|
|
|
|
-type Path string
|
|
|
|
-
|
|
|
|
-// Encoding
|
|
|
|
-//
|
|
|
|
-// An object path is a textual and (with training) human-readable encoding
|
|
|
|
-// of a sequence of destructuring operators, starting from a types.Package.
|
|
|
|
-// The sequences represent a path through the package/object/type graph.
|
|
|
|
-// We classify these operators by their type:
|
|
|
|
-//
|
|
|
|
-// PO package->object Package.Scope.Lookup
|
|
|
|
-// OT object->type Object.Type
|
|
|
|
-// TT type->type Type.{Elem,Key,Params,Results,Underlying} [EKPRU]
|
|
|
|
-// TO type->object Type.{At,Field,Method,Obj} [AFMO]
|
|
|
|
-//
|
|
|
|
-// All valid paths start with a package and end at an object
|
|
|
|
-// and thus may be defined by the regular language:
|
|
|
|
-//
|
|
|
|
-// objectpath = PO (OT TT* TO)*
|
|
|
|
-//
|
|
|
|
-// The concrete encoding follows directly:
|
|
|
|
-// - The only PO operator is Package.Scope.Lookup, which requires an identifier.
|
|
|
|
-// - The only OT operator is Object.Type,
|
|
|
|
-// which we encode as '.' because dot cannot appear in an identifier.
|
|
|
|
-// - The TT operators are encoded as [EKPRUTC];
|
|
|
|
-// one of these (TypeParam) requires an integer operand,
|
|
|
|
-// which is encoded as a string of decimal digits.
|
|
|
|
-// - The TO operators are encoded as [AFMO];
|
|
|
|
-// three of these (At,Field,Method) require an integer operand,
|
|
|
|
-// which is encoded as a string of decimal digits.
|
|
|
|
-// These indices are stable across different representations
|
|
|
|
-// of the same package, even source and export data.
|
|
|
|
-// The indices used are implementation specific and may not correspond to
|
|
|
|
-// the argument to the go/types function.
|
|
|
|
-//
|
|
|
|
-// In the example below,
|
|
|
|
-//
|
|
|
|
-// package p
|
|
|
|
-//
|
|
|
|
-// type T interface {
|
|
|
|
-// f() (a string, b struct{ X int })
|
|
|
|
-// }
|
|
|
|
-//
|
|
|
|
-// field X has the path "T.UM0.RA1.F0",
|
|
|
|
-// representing the following sequence of operations:
|
|
|
|
-//
|
|
|
|
-// p.Lookup("T") T
|
|
|
|
-// .Type().Underlying().Method(0). f
|
|
|
|
-// .Type().Results().At(1) b
|
|
|
|
-// .Type().Field(0) X
|
|
|
|
-//
|
|
|
|
-// The encoding is not maximally compact---every R or P is
|
|
|
|
-// followed by an A, for example---but this simplifies the
|
|
|
|
-// encoder and decoder.
|
|
|
|
-const (
|
|
|
|
- // object->type operators
|
|
|
|
- opType = '.' // .Type() (Object)
|
|
|
|
-
|
|
|
|
- // type->type operators
|
|
|
|
- opElem = 'E' // .Elem() (Pointer, Slice, Array, Chan, Map)
|
|
|
|
- opKey = 'K' // .Key() (Map)
|
|
|
|
- opParams = 'P' // .Params() (Signature)
|
|
|
|
- opResults = 'R' // .Results() (Signature)
|
|
|
|
- opUnderlying = 'U' // .Underlying() (Named)
|
|
|
|
- opTypeParam = 'T' // .TypeParams.At(i) (Named, Signature)
|
|
|
|
- opConstraint = 'C' // .Constraint() (TypeParam)
|
|
|
|
-
|
|
|
|
- // type->object operators
|
|
|
|
- opAt = 'A' // .At(i) (Tuple)
|
|
|
|
- opField = 'F' // .Field(i) (Struct)
|
|
|
|
- opMethod = 'M' // .Method(i) (Named or Interface; not Struct: "promoted" names are ignored)
|
|
|
|
- opObj = 'O' // .Obj() (Named, TypeParam)
|
|
|
|
-)
|
|
|
|
-
|
|
|
|
-// For returns the path to an object relative to its package,
|
|
|
|
-// or an error if the object is not accessible from the package's Scope.
|
|
|
|
-//
|
|
|
|
-// The For function guarantees to return a path only for the following objects:
|
|
|
|
-// - package-level types
|
|
|
|
-// - exported package-level non-types
|
|
|
|
-// - methods
|
|
|
|
-// - parameter and result variables
|
|
|
|
-// - struct fields
|
|
|
|
-// These objects are sufficient to define the API of their package.
|
|
|
|
-// The objects described by a package's export data are drawn from this set.
|
|
|
|
-//
|
|
|
|
-// For does not return a path for predeclared names, imported package
|
|
|
|
-// names, local names, and unexported package-level names (except
|
|
|
|
-// types).
|
|
|
|
-//
|
|
|
|
-// Example: given this definition,
|
|
|
|
-//
|
|
|
|
-// package p
|
|
|
|
-//
|
|
|
|
-// type T interface {
|
|
|
|
-// f() (a string, b struct{ X int })
|
|
|
|
-// }
|
|
|
|
-//
|
|
|
|
-// For(X) would return a path that denotes the following sequence of operations:
|
|
|
|
-//
|
|
|
|
-// p.Scope().Lookup("T") (TypeName T)
|
|
|
|
-// .Type().Underlying().Method(0). (method Func f)
|
|
|
|
-// .Type().Results().At(1) (field Var b)
|
|
|
|
-// .Type().Field(0) (field Var X)
|
|
|
|
-//
|
|
|
|
-// where p is the package (*types.Package) to which X belongs.
|
|
|
|
-func For(obj types.Object) (Path, error) {
|
|
|
|
- return newEncoderFor()(obj)
|
|
|
|
-}
|
|
|
|
-
|
|
|
|
-// An encoder amortizes the cost of encoding the paths of multiple objects.
|
|
|
|
-// Nonexported pending approval of proposal 58668.
|
|
|
|
-type encoder struct {
|
|
|
|
- scopeNamesMemo map[*types.Scope][]string // memoization of Scope.Names()
|
|
|
|
- namedMethodsMemo map[*types.Named][]*types.Func // memoization of namedMethods()
|
|
|
|
-}
|
|
|
|
-
|
|
|
|
-// Exposed to gopls via golang.org/x/tools/internal/typesinternal
|
|
|
|
-// pending approval of proposal 58668.
|
|
|
|
-//
|
|
|
|
-//go:linkname newEncoderFor
|
|
|
|
-func newEncoderFor() func(types.Object) (Path, error) { return new(encoder).For }
|
|
|
|
-
|
|
|
|
-func (enc *encoder) For(obj types.Object) (Path, error) {
|
|
|
|
- pkg := obj.Pkg()
|
|
|
|
-
|
|
|
|
- // This table lists the cases of interest.
|
|
|
|
- //
|
|
|
|
- // Object Action
|
|
|
|
- // ------ ------
|
|
|
|
- // nil reject
|
|
|
|
- // builtin reject
|
|
|
|
- // pkgname reject
|
|
|
|
- // label reject
|
|
|
|
- // var
|
|
|
|
- // package-level accept
|
|
|
|
- // func param/result accept
|
|
|
|
- // local reject
|
|
|
|
- // struct field accept
|
|
|
|
- // const
|
|
|
|
- // package-level accept
|
|
|
|
- // local reject
|
|
|
|
- // func
|
|
|
|
- // package-level accept
|
|
|
|
- // init functions reject
|
|
|
|
- // concrete method accept
|
|
|
|
- // interface method accept
|
|
|
|
- // type
|
|
|
|
- // package-level accept
|
|
|
|
- // local reject
|
|
|
|
- //
|
|
|
|
- // The only accessible package-level objects are members of pkg itself.
|
|
|
|
- //
|
|
|
|
- // The cases are handled in four steps:
|
|
|
|
- //
|
|
|
|
- // 1. reject nil and builtin
|
|
|
|
- // 2. accept package-level objects
|
|
|
|
- // 3. reject obviously invalid objects
|
|
|
|
- // 4. search the API for the path to the param/result/field/method.
|
|
|
|
-
|
|
|
|
- // 1. reference to nil or builtin?
|
|
|
|
- if pkg == nil {
|
|
|
|
- return "", fmt.Errorf("predeclared %s has no path", obj)
|
|
|
|
- }
|
|
|
|
- scope := pkg.Scope()
|
|
|
|
-
|
|
|
|
- // 2. package-level object?
|
|
|
|
- if scope.Lookup(obj.Name()) == obj {
|
|
|
|
- // Only exported objects (and non-exported types) have a path.
|
|
|
|
- // Non-exported types may be referenced by other objects.
|
|
|
|
- if _, ok := obj.(*types.TypeName); !ok && !obj.Exported() {
|
|
|
|
- return "", fmt.Errorf("no path for non-exported %v", obj)
|
|
|
|
- }
|
|
|
|
- return Path(obj.Name()), nil
|
|
|
|
- }
|
|
|
|
-
|
|
|
|
- // 3. Not a package-level object.
|
|
|
|
- // Reject obviously non-viable cases.
|
|
|
|
- switch obj := obj.(type) {
|
|
|
|
- case *types.TypeName:
|
|
|
|
- if _, ok := obj.Type().(*typeparams.TypeParam); !ok {
|
|
|
|
- // With the exception of type parameters, only package-level type names
|
|
|
|
- // have a path.
|
|
|
|
- return "", fmt.Errorf("no path for %v", obj)
|
|
|
|
- }
|
|
|
|
- case *types.Const, // Only package-level constants have a path.
|
|
|
|
- *types.Label, // Labels are function-local.
|
|
|
|
- *types.PkgName: // PkgNames are file-local.
|
|
|
|
- return "", fmt.Errorf("no path for %v", obj)
|
|
|
|
-
|
|
|
|
- case *types.Var:
|
|
|
|
- // Could be:
|
|
|
|
- // - a field (obj.IsField())
|
|
|
|
- // - a func parameter or result
|
|
|
|
- // - a local var.
|
|
|
|
- // Sadly there is no way to distinguish
|
|
|
|
- // a param/result from a local
|
|
|
|
- // so we must proceed to the find.
|
|
|
|
-
|
|
|
|
- case *types.Func:
|
|
|
|
- // A func, if not package-level, must be a method.
|
|
|
|
- if recv := obj.Type().(*types.Signature).Recv(); recv == nil {
|
|
|
|
- return "", fmt.Errorf("func is not a method: %v", obj)
|
|
|
|
- }
|
|
|
|
-
|
|
|
|
- if path, ok := enc.concreteMethod(obj); ok {
|
|
|
|
- // Fast path for concrete methods that avoids looping over scope.
|
|
|
|
- return path, nil
|
|
|
|
- }
|
|
|
|
-
|
|
|
|
- default:
|
|
|
|
- panic(obj)
|
|
|
|
- }
|
|
|
|
-
|
|
|
|
- // 4. Search the API for the path to the var (field/param/result) or method.
|
|
|
|
-
|
|
|
|
- // First inspect package-level named types.
|
|
|
|
- // In the presence of path aliases, these give
|
|
|
|
- // the best paths because non-types may
|
|
|
|
- // refer to types, but not the reverse.
|
|
|
|
- empty := make([]byte, 0, 48) // initial space
|
|
|
|
- names := enc.scopeNames(scope)
|
|
|
|
- for _, name := range names {
|
|
|
|
- o := scope.Lookup(name)
|
|
|
|
- tname, ok := o.(*types.TypeName)
|
|
|
|
- if !ok {
|
|
|
|
- continue // handle non-types in second pass
|
|
|
|
- }
|
|
|
|
-
|
|
|
|
- path := append(empty, name...)
|
|
|
|
- path = append(path, opType)
|
|
|
|
-
|
|
|
|
- T := o.Type()
|
|
|
|
-
|
|
|
|
- if tname.IsAlias() {
|
|
|
|
- // type alias
|
|
|
|
- if r := find(obj, T, path, nil); r != nil {
|
|
|
|
- return Path(r), nil
|
|
|
|
- }
|
|
|
|
- } else {
|
|
|
|
- if named, _ := T.(*types.Named); named != nil {
|
|
|
|
- if r := findTypeParam(obj, typeparams.ForNamed(named), path, nil); r != nil {
|
|
|
|
- // generic named type
|
|
|
|
- return Path(r), nil
|
|
|
|
- }
|
|
|
|
- }
|
|
|
|
- // defined (named) type
|
|
|
|
- if r := find(obj, T.Underlying(), append(path, opUnderlying), nil); r != nil {
|
|
|
|
- return Path(r), nil
|
|
|
|
- }
|
|
|
|
- }
|
|
|
|
- }
|
|
|
|
-
|
|
|
|
- // Then inspect everything else:
|
|
|
|
- // non-types, and declared methods of defined types.
|
|
|
|
- for _, name := range names {
|
|
|
|
- o := scope.Lookup(name)
|
|
|
|
- path := append(empty, name...)
|
|
|
|
- if _, ok := o.(*types.TypeName); !ok {
|
|
|
|
- if o.Exported() {
|
|
|
|
- // exported non-type (const, var, func)
|
|
|
|
- if r := find(obj, o.Type(), append(path, opType), nil); r != nil {
|
|
|
|
- return Path(r), nil
|
|
|
|
- }
|
|
|
|
- }
|
|
|
|
- continue
|
|
|
|
- }
|
|
|
|
-
|
|
|
|
- // Inspect declared methods of defined types.
|
|
|
|
- if T, ok := o.Type().(*types.Named); ok {
|
|
|
|
- path = append(path, opType)
|
|
|
|
- // Note that method index here is always with respect
|
|
|
|
- // to canonical ordering of methods, regardless of how
|
|
|
|
- // they appear in the underlying type.
|
|
|
|
- for i, m := range enc.namedMethods(T) {
|
|
|
|
- path2 := appendOpArg(path, opMethod, i)
|
|
|
|
- if m == obj {
|
|
|
|
- return Path(path2), nil // found declared method
|
|
|
|
- }
|
|
|
|
- if r := find(obj, m.Type(), append(path2, opType), nil); r != nil {
|
|
|
|
- return Path(r), nil
|
|
|
|
- }
|
|
|
|
- }
|
|
|
|
- }
|
|
|
|
- }
|
|
|
|
-
|
|
|
|
- return "", fmt.Errorf("can't find path for %v in %s", obj, pkg.Path())
|
|
|
|
-}
|
|
|
|
-
|
|
|
|
-func appendOpArg(path []byte, op byte, arg int) []byte {
|
|
|
|
- path = append(path, op)
|
|
|
|
- path = strconv.AppendInt(path, int64(arg), 10)
|
|
|
|
- return path
|
|
|
|
-}
|
|
|
|
-
|
|
|
|
-// concreteMethod returns the path for meth, which must have a non-nil receiver.
|
|
|
|
-// The second return value indicates success and may be false if the method is
|
|
|
|
-// an interface method or if it is an instantiated method.
|
|
|
|
-//
|
|
|
|
-// This function is just an optimization that avoids the general scope walking
|
|
|
|
-// approach. You are expected to fall back to the general approach if this
|
|
|
|
-// function fails.
|
|
|
|
-func (enc *encoder) concreteMethod(meth *types.Func) (Path, bool) {
|
|
|
|
- // Concrete methods can only be declared on package-scoped named types. For
|
|
|
|
- // that reason we can skip the expensive walk over the package scope: the
|
|
|
|
- // path will always be package -> named type -> method. We can trivially get
|
|
|
|
- // the type name from the receiver, and only have to look over the type's
|
|
|
|
- // methods to find the method index.
|
|
|
|
- //
|
|
|
|
- // Methods on generic types require special consideration, however. Consider
|
|
|
|
- // the following package:
|
|
|
|
- //
|
|
|
|
- // L1: type S[T any] struct{}
|
|
|
|
- // L2: func (recv S[A]) Foo() { recv.Bar() }
|
|
|
|
- // L3: func (recv S[B]) Bar() { }
|
|
|
|
- // L4: type Alias = S[int]
|
|
|
|
- // L5: func _[T any]() { var s S[int]; s.Foo() }
|
|
|
|
- //
|
|
|
|
- // The receivers of methods on generic types are instantiations. L2 and L3
|
|
|
|
- // instantiate S with the type-parameters A and B, which are scoped to the
|
|
|
|
- // respective methods. L4 and L5 each instantiate S with int. Each of these
|
|
|
|
- // instantiations has its own method set, full of methods (and thus objects)
|
|
|
|
- // with receivers whose types are the respective instantiations. In other
|
|
|
|
- // words, we have
|
|
|
|
- //
|
|
|
|
- // S[A].Foo, S[A].Bar
|
|
|
|
- // S[B].Foo, S[B].Bar
|
|
|
|
- // S[int].Foo, S[int].Bar
|
|
|
|
- //
|
|
|
|
- // We may thus be trying to produce object paths for any of these objects.
|
|
|
|
- //
|
|
|
|
- // S[A].Foo and S[B].Bar are the origin methods, and their paths are S.Foo
|
|
|
|
- // and S.Bar, which are the paths that this function naturally produces.
|
|
|
|
- //
|
|
|
|
- // S[A].Bar, S[B].Foo, and both methods on S[int] are instantiations that
|
|
|
|
- // don't correspond to the origin methods. For S[int], this is significant.
|
|
|
|
- // The most precise object path for S[int].Foo, for example, is Alias.Foo,
|
|
|
|
- // not S.Foo. Our function, however, would produce S.Foo, which would
|
|
|
|
- // resolve to a different object.
|
|
|
|
- //
|
|
|
|
- // For S[A].Bar and S[B].Foo it could be argued that S.Bar and S.Foo are
|
|
|
|
- // still the correct paths, since only the origin methods have meaningful
|
|
|
|
- // paths. But this is likely only true for trivial cases and has edge cases.
|
|
|
|
- // Since this function is only an optimization, we err on the side of giving
|
|
|
|
- // up, deferring to the slower but definitely correct algorithm. Most users
|
|
|
|
- // of objectpath will only be giving us origin methods, anyway, as referring
|
|
|
|
- // to instantiated methods is usually not useful.
|
|
|
|
-
|
|
|
|
- if typeparams.OriginMethod(meth) != meth {
|
|
|
|
- return "", false
|
|
|
|
- }
|
|
|
|
-
|
|
|
|
- recvT := meth.Type().(*types.Signature).Recv().Type()
|
|
|
|
- if ptr, ok := recvT.(*types.Pointer); ok {
|
|
|
|
- recvT = ptr.Elem()
|
|
|
|
- }
|
|
|
|
-
|
|
|
|
- named, ok := recvT.(*types.Named)
|
|
|
|
- if !ok {
|
|
|
|
- return "", false
|
|
|
|
- }
|
|
|
|
-
|
|
|
|
- if types.IsInterface(named) {
|
|
|
|
- // Named interfaces don't have to be package-scoped
|
|
|
|
- //
|
|
|
|
- // TODO(dominikh): opt: if scope.Lookup(name) == named, then we can apply this optimization to interface
|
|
|
|
- // methods, too, I think.
|
|
|
|
- return "", false
|
|
|
|
- }
|
|
|
|
-
|
|
|
|
- // Preallocate space for the name, opType, opMethod, and some digits.
|
|
|
|
- name := named.Obj().Name()
|
|
|
|
- path := make([]byte, 0, len(name)+8)
|
|
|
|
- path = append(path, name...)
|
|
|
|
- path = append(path, opType)
|
|
|
|
- for i, m := range enc.namedMethods(named) {
|
|
|
|
- if m == meth {
|
|
|
|
- path = appendOpArg(path, opMethod, i)
|
|
|
|
- return Path(path), true
|
|
|
|
- }
|
|
|
|
- }
|
|
|
|
-
|
|
|
|
- panic(fmt.Sprintf("couldn't find method %s on type %s", meth, named))
|
|
|
|
-}
|
|
|
|
-
|
|
|
|
-// find finds obj within type T, returning the path to it, or nil if not found.
|
|
|
|
-//
|
|
|
|
-// The seen map is used to short circuit cycles through type parameters. If
|
|
|
|
-// nil, it will be allocated as necessary.
|
|
|
|
-func find(obj types.Object, T types.Type, path []byte, seen map[*types.TypeName]bool) []byte {
|
|
|
|
- switch T := T.(type) {
|
|
|
|
- case *types.Basic, *types.Named:
|
|
|
|
- // Named types belonging to pkg were handled already,
|
|
|
|
- // so T must belong to another package. No path.
|
|
|
|
- return nil
|
|
|
|
- case *types.Pointer:
|
|
|
|
- return find(obj, T.Elem(), append(path, opElem), seen)
|
|
|
|
- case *types.Slice:
|
|
|
|
- return find(obj, T.Elem(), append(path, opElem), seen)
|
|
|
|
- case *types.Array:
|
|
|
|
- return find(obj, T.Elem(), append(path, opElem), seen)
|
|
|
|
- case *types.Chan:
|
|
|
|
- return find(obj, T.Elem(), append(path, opElem), seen)
|
|
|
|
- case *types.Map:
|
|
|
|
- if r := find(obj, T.Key(), append(path, opKey), seen); r != nil {
|
|
|
|
- return r
|
|
|
|
- }
|
|
|
|
- return find(obj, T.Elem(), append(path, opElem), seen)
|
|
|
|
- case *types.Signature:
|
|
|
|
- if r := findTypeParam(obj, typeparams.ForSignature(T), path, seen); r != nil {
|
|
|
|
- return r
|
|
|
|
- }
|
|
|
|
- if r := find(obj, T.Params(), append(path, opParams), seen); r != nil {
|
|
|
|
- return r
|
|
|
|
- }
|
|
|
|
- return find(obj, T.Results(), append(path, opResults), seen)
|
|
|
|
- case *types.Struct:
|
|
|
|
- for i := 0; i < T.NumFields(); i++ {
|
|
|
|
- fld := T.Field(i)
|
|
|
|
- path2 := appendOpArg(path, opField, i)
|
|
|
|
- if fld == obj {
|
|
|
|
- return path2 // found field var
|
|
|
|
- }
|
|
|
|
- if r := find(obj, fld.Type(), append(path2, opType), seen); r != nil {
|
|
|
|
- return r
|
|
|
|
- }
|
|
|
|
- }
|
|
|
|
- return nil
|
|
|
|
- case *types.Tuple:
|
|
|
|
- for i := 0; i < T.Len(); i++ {
|
|
|
|
- v := T.At(i)
|
|
|
|
- path2 := appendOpArg(path, opAt, i)
|
|
|
|
- if v == obj {
|
|
|
|
- return path2 // found param/result var
|
|
|
|
- }
|
|
|
|
- if r := find(obj, v.Type(), append(path2, opType), seen); r != nil {
|
|
|
|
- return r
|
|
|
|
- }
|
|
|
|
- }
|
|
|
|
- return nil
|
|
|
|
- case *types.Interface:
|
|
|
|
- for i := 0; i < T.NumMethods(); i++ {
|
|
|
|
- m := T.Method(i)
|
|
|
|
- path2 := appendOpArg(path, opMethod, i)
|
|
|
|
- if m == obj {
|
|
|
|
- return path2 // found interface method
|
|
|
|
- }
|
|
|
|
- if r := find(obj, m.Type(), append(path2, opType), seen); r != nil {
|
|
|
|
- return r
|
|
|
|
- }
|
|
|
|
- }
|
|
|
|
- return nil
|
|
|
|
- case *typeparams.TypeParam:
|
|
|
|
- name := T.Obj()
|
|
|
|
- if name == obj {
|
|
|
|
- return append(path, opObj)
|
|
|
|
- }
|
|
|
|
- if seen[name] {
|
|
|
|
- return nil
|
|
|
|
- }
|
|
|
|
- if seen == nil {
|
|
|
|
- seen = make(map[*types.TypeName]bool)
|
|
|
|
- }
|
|
|
|
- seen[name] = true
|
|
|
|
- if r := find(obj, T.Constraint(), append(path, opConstraint), seen); r != nil {
|
|
|
|
- return r
|
|
|
|
- }
|
|
|
|
- return nil
|
|
|
|
- }
|
|
|
|
- panic(T)
|
|
|
|
-}
|
|
|
|
-
|
|
|
|
-func findTypeParam(obj types.Object, list *typeparams.TypeParamList, path []byte, seen map[*types.TypeName]bool) []byte {
|
|
|
|
- for i := 0; i < list.Len(); i++ {
|
|
|
|
- tparam := list.At(i)
|
|
|
|
- path2 := appendOpArg(path, opTypeParam, i)
|
|
|
|
- if r := find(obj, tparam, path2, seen); r != nil {
|
|
|
|
- return r
|
|
|
|
- }
|
|
|
|
- }
|
|
|
|
- return nil
|
|
|
|
-}
|
|
|
|
-
|
|
|
|
-// Object returns the object denoted by path p within the package pkg.
|
|
|
|
-func Object(pkg *types.Package, p Path) (types.Object, error) {
|
|
|
|
- if p == "" {
|
|
|
|
- return nil, fmt.Errorf("empty path")
|
|
|
|
- }
|
|
|
|
-
|
|
|
|
- pathstr := string(p)
|
|
|
|
- var pkgobj, suffix string
|
|
|
|
- if dot := strings.IndexByte(pathstr, opType); dot < 0 {
|
|
|
|
- pkgobj = pathstr
|
|
|
|
- } else {
|
|
|
|
- pkgobj = pathstr[:dot]
|
|
|
|
- suffix = pathstr[dot:] // suffix starts with "."
|
|
|
|
- }
|
|
|
|
-
|
|
|
|
- obj := pkg.Scope().Lookup(pkgobj)
|
|
|
|
- if obj == nil {
|
|
|
|
- return nil, fmt.Errorf("package %s does not contain %q", pkg.Path(), pkgobj)
|
|
|
|
- }
|
|
|
|
-
|
|
|
|
- // abstraction of *types.{Pointer,Slice,Array,Chan,Map}
|
|
|
|
- type hasElem interface {
|
|
|
|
- Elem() types.Type
|
|
|
|
- }
|
|
|
|
- // abstraction of *types.{Named,Signature}
|
|
|
|
- type hasTypeParams interface {
|
|
|
|
- TypeParams() *typeparams.TypeParamList
|
|
|
|
- }
|
|
|
|
- // abstraction of *types.{Named,TypeParam}
|
|
|
|
- type hasObj interface {
|
|
|
|
- Obj() *types.TypeName
|
|
|
|
- }
|
|
|
|
-
|
|
|
|
- // The loop state is the pair (t, obj),
|
|
|
|
- // exactly one of which is non-nil, initially obj.
|
|
|
|
- // All suffixes start with '.' (the only object->type operation),
|
|
|
|
- // followed by optional type->type operations,
|
|
|
|
- // then a type->object operation.
|
|
|
|
- // The cycle then repeats.
|
|
|
|
- var t types.Type
|
|
|
|
- for suffix != "" {
|
|
|
|
- code := suffix[0]
|
|
|
|
- suffix = suffix[1:]
|
|
|
|
-
|
|
|
|
- // Codes [AFM] have an integer operand.
|
|
|
|
- var index int
|
|
|
|
- switch code {
|
|
|
|
- case opAt, opField, opMethod, opTypeParam:
|
|
|
|
- rest := strings.TrimLeft(suffix, "0123456789")
|
|
|
|
- numerals := suffix[:len(suffix)-len(rest)]
|
|
|
|
- suffix = rest
|
|
|
|
- i, err := strconv.Atoi(numerals)
|
|
|
|
- if err != nil {
|
|
|
|
- return nil, fmt.Errorf("invalid path: bad numeric operand %q for code %q", numerals, code)
|
|
|
|
- }
|
|
|
|
- index = int(i)
|
|
|
|
- case opObj:
|
|
|
|
- // no operand
|
|
|
|
- default:
|
|
|
|
- // The suffix must end with a type->object operation.
|
|
|
|
- if suffix == "" {
|
|
|
|
- return nil, fmt.Errorf("invalid path: ends with %q, want [AFMO]", code)
|
|
|
|
- }
|
|
|
|
- }
|
|
|
|
-
|
|
|
|
- if code == opType {
|
|
|
|
- if t != nil {
|
|
|
|
- return nil, fmt.Errorf("invalid path: unexpected %q in type context", opType)
|
|
|
|
- }
|
|
|
|
- t = obj.Type()
|
|
|
|
- obj = nil
|
|
|
|
- continue
|
|
|
|
- }
|
|
|
|
-
|
|
|
|
- if t == nil {
|
|
|
|
- return nil, fmt.Errorf("invalid path: code %q in object context", code)
|
|
|
|
- }
|
|
|
|
-
|
|
|
|
- // Inv: t != nil, obj == nil
|
|
|
|
-
|
|
|
|
- switch code {
|
|
|
|
- case opElem:
|
|
|
|
- hasElem, ok := t.(hasElem) // Pointer, Slice, Array, Chan, Map
|
|
|
|
- if !ok {
|
|
|
|
- return nil, fmt.Errorf("cannot apply %q to %s (got %T, want pointer, slice, array, chan or map)", code, t, t)
|
|
|
|
- }
|
|
|
|
- t = hasElem.Elem()
|
|
|
|
-
|
|
|
|
- case opKey:
|
|
|
|
- mapType, ok := t.(*types.Map)
|
|
|
|
- if !ok {
|
|
|
|
- return nil, fmt.Errorf("cannot apply %q to %s (got %T, want map)", code, t, t)
|
|
|
|
- }
|
|
|
|
- t = mapType.Key()
|
|
|
|
-
|
|
|
|
- case opParams:
|
|
|
|
- sig, ok := t.(*types.Signature)
|
|
|
|
- if !ok {
|
|
|
|
- return nil, fmt.Errorf("cannot apply %q to %s (got %T, want signature)", code, t, t)
|
|
|
|
- }
|
|
|
|
- t = sig.Params()
|
|
|
|
-
|
|
|
|
- case opResults:
|
|
|
|
- sig, ok := t.(*types.Signature)
|
|
|
|
- if !ok {
|
|
|
|
- return nil, fmt.Errorf("cannot apply %q to %s (got %T, want signature)", code, t, t)
|
|
|
|
- }
|
|
|
|
- t = sig.Results()
|
|
|
|
-
|
|
|
|
- case opUnderlying:
|
|
|
|
- named, ok := t.(*types.Named)
|
|
|
|
- if !ok {
|
|
|
|
- return nil, fmt.Errorf("cannot apply %q to %s (got %T, want named)", code, t, t)
|
|
|
|
- }
|
|
|
|
- t = named.Underlying()
|
|
|
|
-
|
|
|
|
- case opTypeParam:
|
|
|
|
- hasTypeParams, ok := t.(hasTypeParams) // Named, Signature
|
|
|
|
- if !ok {
|
|
|
|
- return nil, fmt.Errorf("cannot apply %q to %s (got %T, want named or signature)", code, t, t)
|
|
|
|
- }
|
|
|
|
- tparams := hasTypeParams.TypeParams()
|
|
|
|
- if n := tparams.Len(); index >= n {
|
|
|
|
- return nil, fmt.Errorf("tuple index %d out of range [0-%d)", index, n)
|
|
|
|
- }
|
|
|
|
- t = tparams.At(index)
|
|
|
|
-
|
|
|
|
- case opConstraint:
|
|
|
|
- tparam, ok := t.(*typeparams.TypeParam)
|
|
|
|
- if !ok {
|
|
|
|
- return nil, fmt.Errorf("cannot apply %q to %s (got %T, want type parameter)", code, t, t)
|
|
|
|
- }
|
|
|
|
- t = tparam.Constraint()
|
|
|
|
-
|
|
|
|
- case opAt:
|
|
|
|
- tuple, ok := t.(*types.Tuple)
|
|
|
|
- if !ok {
|
|
|
|
- return nil, fmt.Errorf("cannot apply %q to %s (got %T, want tuple)", code, t, t)
|
|
|
|
- }
|
|
|
|
- if n := tuple.Len(); index >= n {
|
|
|
|
- return nil, fmt.Errorf("tuple index %d out of range [0-%d)", index, n)
|
|
|
|
- }
|
|
|
|
- obj = tuple.At(index)
|
|
|
|
- t = nil
|
|
|
|
-
|
|
|
|
- case opField:
|
|
|
|
- structType, ok := t.(*types.Struct)
|
|
|
|
- if !ok {
|
|
|
|
- return nil, fmt.Errorf("cannot apply %q to %s (got %T, want struct)", code, t, t)
|
|
|
|
- }
|
|
|
|
- if n := structType.NumFields(); index >= n {
|
|
|
|
- return nil, fmt.Errorf("field index %d out of range [0-%d)", index, n)
|
|
|
|
- }
|
|
|
|
- obj = structType.Field(index)
|
|
|
|
- t = nil
|
|
|
|
-
|
|
|
|
- case opMethod:
|
|
|
|
- switch t := t.(type) {
|
|
|
|
- case *types.Interface:
|
|
|
|
- if index >= t.NumMethods() {
|
|
|
|
- return nil, fmt.Errorf("method index %d out of range [0-%d)", index, t.NumMethods())
|
|
|
|
- }
|
|
|
|
- obj = t.Method(index) // Id-ordered
|
|
|
|
-
|
|
|
|
- case *types.Named:
|
|
|
|
- methods := namedMethods(t) // (unmemoized)
|
|
|
|
- if index >= len(methods) {
|
|
|
|
- return nil, fmt.Errorf("method index %d out of range [0-%d)", index, len(methods))
|
|
|
|
- }
|
|
|
|
- obj = methods[index] // Id-ordered
|
|
|
|
-
|
|
|
|
- default:
|
|
|
|
- return nil, fmt.Errorf("cannot apply %q to %s (got %T, want interface or named)", code, t, t)
|
|
|
|
- }
|
|
|
|
- t = nil
|
|
|
|
-
|
|
|
|
- case opObj:
|
|
|
|
- hasObj, ok := t.(hasObj)
|
|
|
|
- if !ok {
|
|
|
|
- return nil, fmt.Errorf("cannot apply %q to %s (got %T, want named or type param)", code, t, t)
|
|
|
|
- }
|
|
|
|
- obj = hasObj.Obj()
|
|
|
|
- t = nil
|
|
|
|
-
|
|
|
|
- default:
|
|
|
|
- return nil, fmt.Errorf("invalid path: unknown code %q", code)
|
|
|
|
- }
|
|
|
|
- }
|
|
|
|
-
|
|
|
|
- if obj.Pkg() != pkg {
|
|
|
|
- return nil, fmt.Errorf("path denotes %s, which belongs to a different package", obj)
|
|
|
|
- }
|
|
|
|
-
|
|
|
|
- return obj, nil // success
|
|
|
|
-}
|
|
|
|
-
|
|
|
|
-// namedMethods returns the methods of a Named type in ascending Id order.
|
|
|
|
-func namedMethods(named *types.Named) []*types.Func {
|
|
|
|
- methods := make([]*types.Func, named.NumMethods())
|
|
|
|
- for i := range methods {
|
|
|
|
- methods[i] = named.Method(i)
|
|
|
|
- }
|
|
|
|
- sort.Slice(methods, func(i, j int) bool {
|
|
|
|
- return methods[i].Id() < methods[j].Id()
|
|
|
|
- })
|
|
|
|
- return methods
|
|
|
|
-}
|
|
|
|
-
|
|
|
|
-// scopeNames is a memoization of scope.Names. Callers must not modify the result.
|
|
|
|
-func (enc *encoder) scopeNames(scope *types.Scope) []string {
|
|
|
|
- m := enc.scopeNamesMemo
|
|
|
|
- if m == nil {
|
|
|
|
- m = make(map[*types.Scope][]string)
|
|
|
|
- enc.scopeNamesMemo = m
|
|
|
|
- }
|
|
|
|
- names, ok := m[scope]
|
|
|
|
- if !ok {
|
|
|
|
- names = scope.Names() // allocates and sorts
|
|
|
|
- m[scope] = names
|
|
|
|
- }
|
|
|
|
- return names
|
|
|
|
-}
|
|
|
|
-
|
|
|
|
-// namedMethods is a memoization of the namedMethods function. Callers must not modify the result.
|
|
|
|
-func (enc *encoder) namedMethods(named *types.Named) []*types.Func {
|
|
|
|
- m := enc.namedMethodsMemo
|
|
|
|
- if m == nil {
|
|
|
|
- m = make(map[*types.Named][]*types.Func)
|
|
|
|
- enc.namedMethodsMemo = m
|
|
|
|
- }
|
|
|
|
- methods, ok := m[named]
|
|
|
|
- if !ok {
|
|
|
|
- methods = namedMethods(named) // allocates and sorts
|
|
|
|
- m[named] = methods
|
|
|
|
- }
|
|
|
|
- return methods
|
|
|
|
-
|
|
|
|
-}
|
|
|