update to latest golang.org/x dependencies

vendor/golang.org/x/tools/internal/gcimporter/iexport.go

@@ -21,6 +21,7 @@ import (
 	"sort"
 	"strconv"
 	"strings"
+	"unsafe"
 
 	"golang.org/x/tools/go/types/objectpath"
 	"golang.org/x/tools/internal/aliases"
@@ -464,7 +465,7 @@ func (p *iexporter) doDecl(obj types.Object) {
 
 	switch obj := obj.(type) {
 	case *types.Var:
-		w.tag('V')
+		w.tag(varTag)
 		w.pos(obj.Pos())
 		w.typ(obj.Type(), obj.Pkg())
 
@@ -482,9 +483,9 @@ func (p *iexporter) doDecl(obj types.Object) {
 
 		// Function.
 		if sig.TypeParams().Len() == 0 {
-			w.tag('F')
+			w.tag(funcTag)
 		} else {
-			w.tag('G')
+			w.tag(genericFuncTag)
 		}
 		w.pos(obj.Pos())
 		// The tparam list of the function type is the declaration of the type
@@ -500,7 +501,7 @@ func (p *iexporter) doDecl(obj types.Object) {
 		w.signature(sig)
 
 	case *types.Const:
-		w.tag('C')
+		w.tag(constTag)
 		w.pos(obj.Pos())
 		w.value(obj.Type(), obj.Val())
 
@@ -508,7 +509,7 @@ func (p *iexporter) doDecl(obj types.Object) {
 		t := obj.Type()
 
 		if tparam, ok := aliases.Unalias(t).(*types.TypeParam); ok {
-			w.tag('P')
+			w.tag(typeParamTag)
 			w.pos(obj.Pos())
 			constraint := tparam.Constraint()
 			if p.version >= iexportVersionGo1_18 {
@@ -523,8 +524,13 @@ func (p *iexporter) doDecl(obj types.Object) {
 		}
 
 		if obj.IsAlias() {
-			w.tag('A')
+			w.tag(aliasTag)
 			w.pos(obj.Pos())
+			if alias, ok := t.(*aliases.Alias); ok {
+				// Preserve materialized aliases,
+				// even of non-exported types.
+				t = aliasRHS(alias)
+			}
 			w.typ(t, obj.Pkg())
 			break
 		}
@@ -536,9 +542,9 @@ func (p *iexporter) doDecl(obj types.Object) {
 		}
 
 		if named.TypeParams().Len() == 0 {
-			w.tag('T')
+			w.tag(typeTag)
 		} else {
-			w.tag('U')
+			w.tag(genericTypeTag)
 		}
 		w.pos(obj.Pos())
 
@@ -548,7 +554,7 @@ func (p *iexporter) doDecl(obj types.Object) {
 			w.tparamList(obj.Name(), named.TypeParams(), obj.Pkg())
 		}
 
-		underlying := obj.Type().Underlying()
+		underlying := named.Underlying()
 		w.typ(underlying, obj.Pkg())
 
 		if types.IsInterface(t) {
@@ -739,7 +745,10 @@ func (w *exportWriter) doTyp(t types.Type, pkg *types.Package) {
 		}()
 	}
 	switch t := t.(type) {
-	// TODO(adonovan): support types.Alias.
+	case *aliases.Alias:
+		// TODO(adonovan): support parameterized aliases, following *types.Named.
+		w.startType(aliasType)
+		w.qualifiedType(t.Obj())
 
 	case *types.Named:
 		if targs := t.TypeArgs(); targs.Len() > 0 {
@@ -1322,3 +1331,19 @@ func (e internalError) Error() string { return "gcimporter: " + string(e) }
 func internalErrorf(format string, args ...interface{}) error {
 	return internalError(fmt.Sprintf(format, args...))
 }
+
+// aliasRHS removes exactly one Alias constructor.
+func aliasRHS(alias *aliases.Alias) types.Type {
+	// TODO(adonovan): if proposal #66559 is accepted, this will
+	// become Alias.RHS(alias). In the meantime, we must punch
+	// through the drywall.
+	type go123Alias struct {
+		_   *types.TypeName
+		_   *types.TypeParamList
+		RHS types.Type
+		_   types.Type
+	}
+	var raw *go123Alias
+	*(**aliases.Alias)(unsafe.Pointer(&raw)) = alias
+	return raw.RHS
+}

vendor/golang.org/x/tools/internal/gcimporter/iimport.go

@@ -80,6 +80,20 @@ const (
 	typeParamType
 	instanceType
 	unionType
+	aliasType
+)
+
+// Object tags
+const (
+	varTag          = 'V'
+	funcTag         = 'F'
+	genericFuncTag  = 'G'
+	constTag        = 'C'
+	aliasTag        = 'A'
+	genericAliasTag = 'B'
+	typeParamTag    = 'P'
+	typeTag         = 'T'
+	genericTypeTag  = 'U'
 )
 
 // IImportData imports a package from the serialized package data
@@ -324,7 +338,7 @@ func iimportCommon(fset *token.FileSet, getPackages GetPackagesFunc, data []byte
 	}
 
 	// SetConstraint can't be called if the constraint type is not yet complete.
-	// When type params are created in the 'P' case of (*importReader).obj(),
+	// When type params are created in the typeParamTag case of (*importReader).obj(),
 	// the associated constraint type may not be complete due to recursion.
 	// Therefore, we defer calling SetConstraint there, and call it here instead
 	// after all types are complete.
@@ -546,25 +560,29 @@ func (r *importReader) obj(name string) {
 	pos := r.pos()
 
 	switch tag {
-	case 'A':
+	case aliasTag:
 		typ := r.typ()
+		// TODO(adonovan): support generic aliases:
+		// if tag == genericAliasTag {
+		// 	tparams := r.tparamList()
+		// 	alias.SetTypeParams(tparams)
+		// }
+		r.declare(aliases.NewAlias(pos, r.currPkg, name, typ))
 
-		r.declare(types.NewTypeName(pos, r.currPkg, name, typ))
-
-	case 'C':
+	case constTag:
 		typ, val := r.value()
 
 		r.declare(types.NewConst(pos, r.currPkg, name, typ, val))
 
-	case 'F', 'G':
+	case funcTag, genericFuncTag:
 		var tparams []*types.TypeParam
-		if tag == 'G' {
+		if tag == genericFuncTag {
 			tparams = r.tparamList()
 		}
 		sig := r.signature(nil, nil, tparams)
 		r.declare(types.NewFunc(pos, r.currPkg, name, sig))
 
-	case 'T', 'U':
+	case typeTag, genericTypeTag:
 		// Types can be recursive. We need to setup a stub
 		// declaration before recursing.
 		obj := types.NewTypeName(pos, r.currPkg, name, nil)
@@ -572,7 +590,7 @@ func (r *importReader) obj(name string) {
 		// Declare obj before calling r.tparamList, so the new type name is recognized
 		// if used in the constraint of one of its own typeparams (see #48280).
 		r.declare(obj)
-		if tag == 'U' {
+		if tag == genericTypeTag {
 			tparams := r.tparamList()
 			named.SetTypeParams(tparams)
 		}
@@ -604,7 +622,7 @@ func (r *importReader) obj(name string) {
 			}
 		}
 
-	case 'P':
+	case typeParamTag:
 		// We need to "declare" a typeparam in order to have a name that
 		// can be referenced recursively (if needed) in the type param's
 		// bound.
@@ -637,7 +655,7 @@ func (r *importReader) obj(name string) {
 		// completely set up all types in ImportData.
 		r.p.later = append(r.p.later, setConstraintArgs{t: t, constraint: constraint})
 
-	case 'V':
+	case varTag:
 		typ := r.typ()
 
 		r.declare(types.NewVar(pos, r.currPkg, name, typ))
@@ -854,7 +872,7 @@ func (r *importReader) doType(base *types.Named) (res types.Type) {
 		errorf("unexpected kind tag in %q: %v", r.p.ipath, k)
 		return nil
 
-	case definedType:
+	case aliasType, definedType:
 		pkg, name := r.qualifiedIdent()
 		r.p.doDecl(pkg, name)
 		return pkg.Scope().Lookup(name).(*types.TypeName).Type()

vendor/golang.org/x/tools/internal/gcimporter/ureader_yes.go

@@ -524,7 +524,7 @@ func (pr *pkgReader) objIdx(idx pkgbits.Index) (*types.Package, string) {
 		case pkgbits.ObjAlias:
 			pos := r.pos()
 			typ := r.typ()
-			declare(types.NewTypeName(pos, objPkg, objName, typ))
+			declare(aliases.NewAlias(pos, objPkg, objName, typ))
 
 		case pkgbits.ObjConst:
 			pos := r.pos()

vendor/golang.org/x/tools/internal/gocommand/invoke.go

@@ -158,12 +158,15 @@ type Invocation struct {
 	BuildFlags []string
 
 	// If ModFlag is set, the go command is invoked with -mod=ModFlag.
+	// TODO(rfindley): remove, in favor of Args.
 	ModFlag string
 
 	// If ModFile is set, the go command is invoked with -modfile=ModFile.
+	// TODO(rfindley): remove, in favor of Args.
 	ModFile string
 
 	// If Overlay is set, the go command is invoked with -overlay=Overlay.
+	// TODO(rfindley): remove, in favor of Args.
 	Overlay string
 
 	// If CleanEnv is set, the invocation will run only with the environment

vendor/golang.org/x/tools/internal/stdlib/stdlib.go

@@ -0,0 +1,97 @@
+// Copyright 2022 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.
+
+//go:generate go run generate.go
+
+// Package stdlib provides a table of all exported symbols in the
+// standard library, along with the version at which they first
+// appeared.
+package stdlib
+
+import (
+	"fmt"
+	"strings"
+)
+
+type Symbol struct {
+	Name    string
+	Kind    Kind
+	Version Version // Go version that first included the symbol
+}
+
+// A Kind indicates the kind of a symbol:
+// function, variable, constant, type, and so on.
+type Kind int8
+
+const (
+	Invalid Kind = iota // Example name:
+	Type                // "Buffer"
+	Func                // "Println"
+	Var                 // "EOF"
+	Const               // "Pi"
+	Field               // "Point.X"
+	Method              // "(*Buffer).Grow"
+)
+
+func (kind Kind) String() string {
+	return [...]string{
+		Invalid: "invalid",
+		Type:    "type",
+		Func:    "func",
+		Var:     "var",
+		Const:   "const",
+		Field:   "field",
+		Method:  "method",
+	}[kind]
+}
+
+// A Version represents a version of Go of the form "go1.%d".
+type Version int8
+
+// String returns a version string of the form "go1.23", without allocating.
+func (v Version) String() string { return versions[v] }
+
+var versions [30]string // (increase constant as needed)
+
+func init() {
+	for i := range versions {
+		versions[i] = fmt.Sprintf("go1.%d", i)
+	}
+}
+
+// HasPackage reports whether the specified package path is part of
+// the standard library's public API.
+func HasPackage(path string) bool {
+	_, ok := PackageSymbols[path]
+	return ok
+}
+
+// SplitField splits the field symbol name into type and field
+// components. It must be called only on Field symbols.
+//
+// Example: "File.Package" -> ("File", "Package")
+func (sym *Symbol) SplitField() (typename, name string) {
+	if sym.Kind != Field {
+		panic("not a field")
+	}
+	typename, name, _ = strings.Cut(sym.Name, ".")
+	return
+}
+
+// SplitMethod splits the method symbol name into pointer, receiver,
+// and method components. It must be called only on Method symbols.
+//
+// Example: "(*Buffer).Grow" -> (true, "Buffer", "Grow")
+func (sym *Symbol) SplitMethod() (ptr bool, recv, name string) {
+	if sym.Kind != Method {
+		panic("not a method")
+	}
+	recv, name, _ = strings.Cut(sym.Name, ".")
+	recv = recv[len("(") : len(recv)-len(")")]
+	ptr = recv[0] == '*'
+	if ptr {
+		recv = recv[len("*"):]
+	}
+	return
+}

vendor/golang.org/x/tools/internal/typeparams/common.go

@@ -1,195 +0,0 @@
-// Copyright 2021 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 typeparams contains common utilities for writing tools that
-// interact with generic Go code, as introduced with Go 1.18. It
-// supplements the standard library APIs. Notably, the StructuralTerms
-// API computes a minimal representation of the structural
-// restrictions on a type parameter.
-//
-// An external version of these APIs is available in the
-// golang.org/x/exp/typeparams module.
-package typeparams
-
-import (
-	"fmt"
-	"go/ast"
-	"go/token"
-	"go/types"
-
-	"golang.org/x/tools/internal/aliases"
-	"golang.org/x/tools/internal/typesinternal"
-)
-
-// UnpackIndexExpr extracts data from AST nodes that represent index
-// expressions.
-//
-// For an ast.IndexExpr, the resulting indices slice will contain exactly one
-// index expression. For an ast.IndexListExpr (go1.18+), it may have a variable
-// number of index expressions.
-//
-// For nodes that don't represent index expressions, the first return value of
-// UnpackIndexExpr will be nil.
-func UnpackIndexExpr(n ast.Node) (x ast.Expr, lbrack token.Pos, indices []ast.Expr, rbrack token.Pos) {
-	switch e := n.(type) {
-	case *ast.IndexExpr:
-		return e.X, e.Lbrack, []ast.Expr{e.Index}, e.Rbrack
-	case *ast.IndexListExpr:
-		return e.X, e.Lbrack, e.Indices, e.Rbrack
-	}
-	return nil, token.NoPos, nil, token.NoPos
-}
-
-// PackIndexExpr returns an *ast.IndexExpr or *ast.IndexListExpr, depending on
-// the cardinality of indices. Calling PackIndexExpr with len(indices) == 0
-// will panic.
-func PackIndexExpr(x ast.Expr, lbrack token.Pos, indices []ast.Expr, rbrack token.Pos) ast.Expr {
-	switch len(indices) {
-	case 0:
-		panic("empty indices")
-	case 1:
-		return &ast.IndexExpr{
-			X:      x,
-			Lbrack: lbrack,
-			Index:  indices[0],
-			Rbrack: rbrack,
-		}
-	default:
-		return &ast.IndexListExpr{
-			X:       x,
-			Lbrack:  lbrack,
-			Indices: indices,
-			Rbrack:  rbrack,
-		}
-	}
-}
-
-// IsTypeParam reports whether t is a type parameter (or an alias of one).
-func IsTypeParam(t types.Type) bool {
-	_, ok := aliases.Unalias(t).(*types.TypeParam)
-	return ok
-}
-
-// OriginMethod returns the origin method associated with the method fn.
-// For methods on a non-generic receiver base type, this is just
-// fn. However, for methods with a generic receiver, OriginMethod returns the
-// corresponding method in the method set of the origin type.
-//
-// As a special case, if fn is not a method (has no receiver), OriginMethod
-// returns fn.
-func OriginMethod(fn *types.Func) *types.Func {
-	recv := fn.Type().(*types.Signature).Recv()
-	if recv == nil {
-		return fn
-	}
-	_, named := typesinternal.ReceiverNamed(recv)
-	if named == nil {
-		// Receiver is a *types.Interface.
-		return fn
-	}
-	if named.TypeParams().Len() == 0 {
-		// Receiver base has no type parameters, so we can avoid the lookup below.
-		return fn
-	}
-	orig := named.Origin()
-	gfn, _, _ := types.LookupFieldOrMethod(orig, true, fn.Pkg(), fn.Name())
-
-	// This is a fix for a gopls crash (#60628) due to a go/types bug (#60634). In:
-	// 	package p
-	//      type T *int
-	//      func (*T) f() {}
-	// LookupFieldOrMethod(T, true, p, f)=nil, but NewMethodSet(*T)={(*T).f}.
-	// Here we make them consistent by force.
-	// (The go/types bug is general, but this workaround is reached only
-	// for generic T thanks to the early return above.)
-	if gfn == nil {
-		mset := types.NewMethodSet(types.NewPointer(orig))
-		for i := 0; i < mset.Len(); i++ {
-			m := mset.At(i)
-			if m.Obj().Id() == fn.Id() {
-				gfn = m.Obj()
-				break
-			}
-		}
-	}
-
-	// In golang/go#61196, we observe another crash, this time inexplicable.
-	if gfn == nil {
-		panic(fmt.Sprintf("missing origin method for %s.%s; named == origin: %t, named.NumMethods(): %d, origin.NumMethods(): %d", named, fn, named == orig, named.NumMethods(), orig.NumMethods()))
-	}
-
-	return gfn.(*types.Func)
-}
-
-// GenericAssignableTo is a generalization of types.AssignableTo that
-// implements the following rule for uninstantiated generic types:
-//
-// If V and T are generic named types, then V is considered assignable to T if,
-// for every possible instantation of V[A_1, ..., A_N], the instantiation
-// T[A_1, ..., A_N] is valid and V[A_1, ..., A_N] implements T[A_1, ..., A_N].
-//
-// If T has structural constraints, they must be satisfied by V.
-//
-// For example, consider the following type declarations:
-//
-//	type Interface[T any] interface {
-//		Accept(T)
-//	}
-//
-//	type Container[T any] struct {
-//		Element T
-//	}
-//
-//	func (c Container[T]) Accept(t T) { c.Element = t }
-//
-// In this case, GenericAssignableTo reports that instantiations of Container
-// are assignable to the corresponding instantiation of Interface.
-func GenericAssignableTo(ctxt *types.Context, V, T types.Type) bool {
-	V = aliases.Unalias(V)
-	T = aliases.Unalias(T)
-
-	// If V and T are not both named, or do not have matching non-empty type
-	// parameter lists, fall back on types.AssignableTo.
-
-	VN, Vnamed := V.(*types.Named)
-	TN, Tnamed := T.(*types.Named)
-	if !Vnamed || !Tnamed {
-		return types.AssignableTo(V, T)
-	}
-
-	vtparams := VN.TypeParams()
-	ttparams := TN.TypeParams()
-	if vtparams.Len() == 0 || vtparams.Len() != ttparams.Len() || VN.TypeArgs().Len() != 0 || TN.TypeArgs().Len() != 0 {
-		return types.AssignableTo(V, T)
-	}
-
-	// V and T have the same (non-zero) number of type params. Instantiate both
-	// with the type parameters of V. This must always succeed for V, and will
-	// succeed for T if and only if the type set of each type parameter of V is a
-	// subset of the type set of the corresponding type parameter of T, meaning
-	// that every instantiation of V corresponds to a valid instantiation of T.
-
-	// Minor optimization: ensure we share a context across the two
-	// instantiations below.
-	if ctxt == nil {
-		ctxt = types.NewContext()
-	}
-
-	var targs []types.Type
-	for i := 0; i < vtparams.Len(); i++ {
-		targs = append(targs, vtparams.At(i))
-	}
-
-	vinst, err := types.Instantiate(ctxt, V, targs, true)
-	if err != nil {
-		panic("type parameters should satisfy their own constraints")
-	}
-
-	tinst, err := types.Instantiate(ctxt, T, targs, true)
-	if err != nil {
-		return false
-	}
-
-	return types.AssignableTo(vinst, tinst)
-}

vendor/golang.org/x/tools/internal/typeparams/coretype.go

@@ -1,137 +0,0 @@
-// Copyright 2022 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 typeparams
-
-import (
-	"fmt"
-	"go/types"
-
-	"golang.org/x/tools/internal/aliases"
-)
-
-// CoreType returns the core type of T or nil if T does not have a core type.
-//
-// See https://go.dev/ref/spec#Core_types for the definition of a core type.
-func CoreType(T types.Type) types.Type {
-	U := T.Underlying()
-	if _, ok := U.(*types.Interface); !ok {
-		return U // for non-interface types,
-	}
-
-	terms, err := _NormalTerms(U)
-	if len(terms) == 0 || err != nil {
-		// len(terms) -> empty type set of interface.
-		// err != nil => U is invalid, exceeds complexity bounds, or has an empty type set.
-		return nil // no core type.
-	}
-
-	U = terms[0].Type().Underlying()
-	var identical int // i in [0,identical) => Identical(U, terms[i].Type().Underlying())
-	for identical = 1; identical < len(terms); identical++ {
-		if !types.Identical(U, terms[identical].Type().Underlying()) {
-			break
-		}
-	}
-
-	if identical == len(terms) {
-		// https://go.dev/ref/spec#Core_types
-		// "There is a single type U which is the underlying type of all types in the type set of T"
-		return U
-	}
-	ch, ok := U.(*types.Chan)
-	if !ok {
-		return nil // no core type as identical < len(terms) and U is not a channel.
-	}
-	// https://go.dev/ref/spec#Core_types
-	// "the type chan E if T contains only bidirectional channels, or the type chan<- E or
-	// <-chan E depending on the direction of the directional channels present."
-	for chans := identical; chans < len(terms); chans++ {
-		curr, ok := terms[chans].Type().Underlying().(*types.Chan)
-		if !ok {
-			return nil
-		}
-		if !types.Identical(ch.Elem(), curr.Elem()) {
-			return nil // channel elements are not identical.
-		}
-		if ch.Dir() == types.SendRecv {
-			// ch is bidirectional. We can safely always use curr's direction.
-			ch = curr
-		} else if curr.Dir() != types.SendRecv && ch.Dir() != curr.Dir() {
-			// ch and curr are not bidirectional and not the same direction.
-			return nil
-		}
-	}
-	return ch
-}
-
-// _NormalTerms returns a slice of terms representing the normalized structural
-// type restrictions of a type, if any.
-//
-// For all types other than *types.TypeParam, *types.Interface, and
-// *types.Union, this is just a single term with Tilde() == false and
-// Type() == typ. For *types.TypeParam, *types.Interface, and *types.Union, see
-// below.
-//
-// Structural type restrictions of a type parameter are created via
-// non-interface types embedded in its constraint interface (directly, or via a
-// chain of interface embeddings). For example, in the declaration type
-// T[P interface{~int; m()}] int the structural restriction of the type
-// parameter P is ~int.
-//
-// With interface embedding and unions, the specification of structural type
-// restrictions may be arbitrarily complex. For example, consider the
-// following:
-//
-//	type A interface{ ~string|~[]byte }
-//
-//	type B interface{ int|string }
-//
-//	type C interface { ~string|~int }
-//
-//	type T[P interface{ A|B; C }] int
-//
-// In this example, the structural type restriction of P is ~string|int: A|B
-// expands to ~string|~[]byte|int|string, which reduces to ~string|~[]byte|int,
-// which when intersected with C (~string|~int) yields ~string|int.
-//
-// _NormalTerms computes these expansions and reductions, producing a
-// "normalized" form of the embeddings. A structural restriction is normalized
-// if it is a single union containing no interface terms, and is minimal in the
-// sense that removing any term changes the set of types satisfying the
-// constraint. It is left as a proof for the reader that, modulo sorting, there
-// is exactly one such normalized form.
-//
-// Because the minimal representation always takes this form, _NormalTerms
-// returns a slice of tilde terms corresponding to the terms of the union in
-// the normalized structural restriction. An error is returned if the type is
-// invalid, exceeds complexity bounds, or has an empty type set. In the latter
-// case, _NormalTerms returns ErrEmptyTypeSet.
-//
-// _NormalTerms makes no guarantees about the order of terms, except that it
-// is deterministic.
-func _NormalTerms(typ types.Type) ([]*types.Term, error) {
-	switch typ := aliases.Unalias(typ).(type) {
-	case *types.TypeParam:
-		return StructuralTerms(typ)
-	case *types.Union:
-		return UnionTermSet(typ)
-	case *types.Interface:
-		return InterfaceTermSet(typ)
-	default:
-		return []*types.Term{types.NewTerm(false, typ)}, nil
-	}
-}
-
-// MustDeref returns the type of the variable pointed to by t.
-// It panics if t's core type is not a pointer.
-//
-// TODO(adonovan): ideally this would live in typesinternal, but that
-// creates an import cycle. Move there when we melt this package down.
-func MustDeref(t types.Type) types.Type {
-	if ptr, ok := CoreType(t).(*types.Pointer); ok {
-		return ptr.Elem()
-	}
-	panic(fmt.Sprintf("%v is not a pointer", t))
-}

vendor/golang.org/x/tools/internal/typeparams/normalize.go

@@ -1,218 +0,0 @@
-// Copyright 2021 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 typeparams
-
-import (
-	"errors"
-	"fmt"
-	"go/types"
-	"os"
-	"strings"
-)
-
-//go:generate go run copytermlist.go
-
-const debug = false
-
-var ErrEmptyTypeSet = errors.New("empty type set")
-
-// StructuralTerms returns a slice of terms representing the normalized
-// structural type restrictions of a type parameter, if any.
-//
-// Structural type restrictions of a type parameter are created via
-// non-interface types embedded in its constraint interface (directly, or via a
-// chain of interface embeddings). For example, in the declaration
-//
-//	type T[P interface{~int; m()}] int
-//
-// the structural restriction of the type parameter P is ~int.
-//
-// With interface embedding and unions, the specification of structural type
-// restrictions may be arbitrarily complex. For example, consider the
-// following:
-//
-//	type A interface{ ~string|~[]byte }
-//
-//	type B interface{ int|string }
-//
-//	type C interface { ~string|~int }
-//
-//	type T[P interface{ A|B; C }] int
-//
-// In this example, the structural type restriction of P is ~string|int: A|B
-// expands to ~string|~[]byte|int|string, which reduces to ~string|~[]byte|int,
-// which when intersected with C (~string|~int) yields ~string|int.
-//
-// StructuralTerms computes these expansions and reductions, producing a
-// "normalized" form of the embeddings. A structural restriction is normalized
-// if it is a single union containing no interface terms, and is minimal in the
-// sense that removing any term changes the set of types satisfying the
-// constraint. It is left as a proof for the reader that, modulo sorting, there
-// is exactly one such normalized form.
-//
-// Because the minimal representation always takes this form, StructuralTerms
-// returns a slice of tilde terms corresponding to the terms of the union in
-// the normalized structural restriction. An error is returned if the
-// constraint interface is invalid, exceeds complexity bounds, or has an empty
-// type set. In the latter case, StructuralTerms returns ErrEmptyTypeSet.
-//
-// StructuralTerms makes no guarantees about the order of terms, except that it
-// is deterministic.
-func StructuralTerms(tparam *types.TypeParam) ([]*types.Term, error) {
-	constraint := tparam.Constraint()
-	if constraint == nil {
-		return nil, fmt.Errorf("%s has nil constraint", tparam)
-	}
-	iface, _ := constraint.Underlying().(*types.Interface)
-	if iface == nil {
-		return nil, fmt.Errorf("constraint is %T, not *types.Interface", constraint.Underlying())
-	}
-	return InterfaceTermSet(iface)
-}
-
-// InterfaceTermSet computes the normalized terms for a constraint interface,
-// returning an error if the term set cannot be computed or is empty. In the
-// latter case, the error will be ErrEmptyTypeSet.
-//
-// See the documentation of StructuralTerms for more information on
-// normalization.
-func InterfaceTermSet(iface *types.Interface) ([]*types.Term, error) {
-	return computeTermSet(iface)
-}
-
-// UnionTermSet computes the normalized terms for a union, returning an error
-// if the term set cannot be computed or is empty. In the latter case, the
-// error will be ErrEmptyTypeSet.
-//
-// See the documentation of StructuralTerms for more information on
-// normalization.
-func UnionTermSet(union *types.Union) ([]*types.Term, error) {
-	return computeTermSet(union)
-}
-
-func computeTermSet(typ types.Type) ([]*types.Term, error) {
-	tset, err := computeTermSetInternal(typ, make(map[types.Type]*termSet), 0)
-	if err != nil {
-		return nil, err
-	}
-	if tset.terms.isEmpty() {
-		return nil, ErrEmptyTypeSet
-	}
-	if tset.terms.isAll() {
-		return nil, nil
-	}
-	var terms []*types.Term
-	for _, term := range tset.terms {
-		terms = append(terms, types.NewTerm(term.tilde, term.typ))
-	}
-	return terms, nil
-}
-
-// A termSet holds the normalized set of terms for a given type.
-//
-// The name termSet is intentionally distinct from 'type set': a type set is
-// all types that implement a type (and includes method restrictions), whereas
-// a term set just represents the structural restrictions on a type.
-type termSet struct {
-	complete bool
-	terms    termlist
-}
-
-func indentf(depth int, format string, args ...interface{}) {
-	fmt.Fprintf(os.Stderr, strings.Repeat(".", depth)+format+"\n", args...)
-}
-
-func computeTermSetInternal(t types.Type, seen map[types.Type]*termSet, depth int) (res *termSet, err error) {
-	if t == nil {
-		panic("nil type")
-	}
-
-	if debug {
-		indentf(depth, "%s", t.String())
-		defer func() {
-			if err != nil {
-				indentf(depth, "=> %s", err)
-			} else {
-				indentf(depth, "=> %s", res.terms.String())
-			}
-		}()
-	}
-
-	const maxTermCount = 100
-	if tset, ok := seen[t]; ok {
-		if !tset.complete {
-			return nil, fmt.Errorf("cycle detected in the declaration of %s", t)
-		}
-		return tset, nil
-	}
-
-	// Mark the current type as seen to avoid infinite recursion.
-	tset := new(termSet)
-	defer func() {
-		tset.complete = true
-	}()
-	seen[t] = tset
-
-	switch u := t.Underlying().(type) {
-	case *types.Interface:
-		// The term set of an interface is the intersection of the term sets of its
-		// embedded types.
-		tset.terms = allTermlist
-		for i := 0; i < u.NumEmbeddeds(); i++ {
-			embedded := u.EmbeddedType(i)
-			if _, ok := embedded.Underlying().(*types.TypeParam); ok {
-				return nil, fmt.Errorf("invalid embedded type %T", embedded)
-			}
-			tset2, err := computeTermSetInternal(embedded, seen, depth+1)
-			if err != nil {
-				return nil, err
-			}
-			tset.terms = tset.terms.intersect(tset2.terms)
-		}
-	case *types.Union:
-		// The term set of a union is the union of term sets of its terms.
-		tset.terms = nil
-		for i := 0; i < u.Len(); i++ {
-			t := u.Term(i)
-			var terms termlist
-			switch t.Type().Underlying().(type) {
-			case *types.Interface:
-				tset2, err := computeTermSetInternal(t.Type(), seen, depth+1)
-				if err != nil {
-					return nil, err
-				}
-				terms = tset2.terms
-			case *types.TypeParam, *types.Union:
-				// A stand-alone type parameter or union is not permitted as union
-				// term.
-				return nil, fmt.Errorf("invalid union term %T", t)
-			default:
-				if t.Type() == types.Typ[types.Invalid] {
-					continue
-				}
-				terms = termlist{{t.Tilde(), t.Type()}}
-			}
-			tset.terms = tset.terms.union(terms)
-			if len(tset.terms) > maxTermCount {
-				return nil, fmt.Errorf("exceeded max term count %d", maxTermCount)
-			}
-		}
-	case *types.TypeParam:
-		panic("unreachable")
-	default:
-		// For all other types, the term set is just a single non-tilde term
-		// holding the type itself.
-		if u != types.Typ[types.Invalid] {
-			tset.terms = termlist{{false, t}}
-		}
-	}
-	return tset, nil
-}
-
-// under is a facade for the go/types internal function of the same name. It is
-// used by typeterm.go.
-func under(t types.Type) types.Type {
-	return t.Underlying()
-}

vendor/golang.org/x/tools/internal/typeparams/termlist.go

@@ -1,163 +0,0 @@
-// Copyright 2021 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.
-
-// Code generated by copytermlist.go DO NOT EDIT.
-
-package typeparams
-
-import (
-	"bytes"
-	"go/types"
-)
-
-// A termlist represents the type set represented by the union
-// t1 ∪ y2 ∪ ... tn of the type sets of the terms t1 to tn.
-// A termlist is in normal form if all terms are disjoint.
-// termlist operations don't require the operands to be in
-// normal form.
-type termlist []*term
-
-// allTermlist represents the set of all types.
-// It is in normal form.
-var allTermlist = termlist{new(term)}
-
-// String prints the termlist exactly (without normalization).
-func (xl termlist) String() string {
-	if len(xl) == 0 {
-		return "∅"
-	}
-	var buf bytes.Buffer
-	for i, x := range xl {
-		if i > 0 {
-			buf.WriteString(" | ")
-		}
-		buf.WriteString(x.String())
-	}
-	return buf.String()
-}
-
-// isEmpty reports whether the termlist xl represents the empty set of types.
-func (xl termlist) isEmpty() bool {
-	// If there's a non-nil term, the entire list is not empty.
-	// If the termlist is in normal form, this requires at most
-	// one iteration.
-	for _, x := range xl {
-		if x != nil {
-			return false
-		}
-	}
-	return true
-}
-
-// isAll reports whether the termlist xl represents the set of all types.
-func (xl termlist) isAll() bool {
-	// If there's a 𝓤 term, the entire list is 𝓤.
-	// If the termlist is in normal form, this requires at most
-	// one iteration.
-	for _, x := range xl {
-		if x != nil && x.typ == nil {
-			return true
-		}
-	}
-	return false
-}
-
-// norm returns the normal form of xl.
-func (xl termlist) norm() termlist {
-	// Quadratic algorithm, but good enough for now.
-	// TODO(gri) fix asymptotic performance
-	used := make([]bool, len(xl))
-	var rl termlist
-	for i, xi := range xl {
-		if xi == nil || used[i] {
-			continue
-		}
-		for j := i + 1; j < len(xl); j++ {
-			xj := xl[j]
-			if xj == nil || used[j] {
-				continue
-			}
-			if u1, u2 := xi.union(xj); u2 == nil {
-				// If we encounter a 𝓤 term, the entire list is 𝓤.
-				// Exit early.
-				// (Note that this is not just an optimization;
-				// if we continue, we may end up with a 𝓤 term
-				// and other terms and the result would not be
-				// in normal form.)
-				if u1.typ == nil {
-					return allTermlist
-				}
-				xi = u1
-				used[j] = true // xj is now unioned into xi - ignore it in future iterations
-			}
-		}
-		rl = append(rl, xi)
-	}
-	return rl
-}
-
-// union returns the union xl ∪ yl.
-func (xl termlist) union(yl termlist) termlist {
-	return append(xl, yl...).norm()
-}
-
-// intersect returns the intersection xl ∩ yl.
-func (xl termlist) intersect(yl termlist) termlist {
-	if xl.isEmpty() || yl.isEmpty() {
-		return nil
-	}
-
-	// Quadratic algorithm, but good enough for now.
-	// TODO(gri) fix asymptotic performance
-	var rl termlist
-	for _, x := range xl {
-		for _, y := range yl {
-			if r := x.intersect(y); r != nil {
-				rl = append(rl, r)
-			}
-		}
-	}
-	return rl.norm()
-}
-
-// equal reports whether xl and yl represent the same type set.
-func (xl termlist) equal(yl termlist) bool {
-	// TODO(gri) this should be more efficient
-	return xl.subsetOf(yl) && yl.subsetOf(xl)
-}
-
-// includes reports whether t ∈ xl.
-func (xl termlist) includes(t types.Type) bool {
-	for _, x := range xl {
-		if x.includes(t) {
-			return true
-		}
-	}
-	return false
-}
-
-// supersetOf reports whether y ⊆ xl.
-func (xl termlist) supersetOf(y *term) bool {
-	for _, x := range xl {
-		if y.subsetOf(x) {
-			return true
-		}
-	}
-	return false
-}
-
-// subsetOf reports whether xl ⊆ yl.
-func (xl termlist) subsetOf(yl termlist) bool {
-	if yl.isEmpty() {
-		return xl.isEmpty()
-	}
-
-	// each term x of xl must be a subset of yl
-	for _, x := range xl {
-		if !yl.supersetOf(x) {
-			return false // x is not a subset yl
-		}
-	}
-	return true
-}

vendor/golang.org/x/tools/internal/typeparams/typeterm.go

@@ -1,169 +0,0 @@
-// Copyright 2021 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.
-
-// Code generated by copytermlist.go DO NOT EDIT.
-
-package typeparams
-
-import "go/types"
-
-// A term describes elementary type sets:
-//
-//	 ∅:  (*term)(nil)     == ∅                      // set of no types (empty set)
-//	 𝓤:  &term{}          == 𝓤                      // set of all types (𝓤niverse)
-//	 T:  &term{false, T}  == {T}                    // set of type T
-//	~t:  &term{true, t}   == {t' | under(t') == t}  // set of types with underlying type t
-type term struct {
-	tilde bool // valid if typ != nil
-	typ   types.Type
-}
-
-func (x *term) String() string {
-	switch {
-	case x == nil:
-		return "∅"
-	case x.typ == nil:
-		return "𝓤"
-	case x.tilde:
-		return "~" + x.typ.String()
-	default:
-		return x.typ.String()
-	}
-}
-
-// equal reports whether x and y represent the same type set.
-func (x *term) equal(y *term) bool {
-	// easy cases
-	switch {
-	case x == nil || y == nil:
-		return x == y
-	case x.typ == nil || y.typ == nil:
-		return x.typ == y.typ
-	}
-	// ∅ ⊂ x, y ⊂ 𝓤
-
-	return x.tilde == y.tilde && types.Identical(x.typ, y.typ)
-}
-
-// union returns the union x ∪ y: zero, one, or two non-nil terms.
-func (x *term) union(y *term) (_, _ *term) {
-	// easy cases
-	switch {
-	case x == nil && y == nil:
-		return nil, nil // ∅ ∪ ∅ == ∅
-	case x == nil:
-		return y, nil // ∅ ∪ y == y
-	case y == nil:
-		return x, nil // x ∪ ∅ == x
-	case x.typ == nil:
-		return x, nil // 𝓤 ∪ y == 𝓤
-	case y.typ == nil:
-		return y, nil // x ∪ 𝓤 == 𝓤
-	}
-	// ∅ ⊂ x, y ⊂ 𝓤
-
-	if x.disjoint(y) {
-		return x, y // x ∪ y == (x, y) if x ∩ y == ∅
-	}
-	// x.typ == y.typ
-
-	// ~t ∪ ~t == ~t
-	// ~t ∪  T == ~t
-	//  T ∪ ~t == ~t
-	//  T ∪  T ==  T
-	if x.tilde || !y.tilde {
-		return x, nil
-	}
-	return y, nil
-}
-
-// intersect returns the intersection x ∩ y.
-func (x *term) intersect(y *term) *term {
-	// easy cases
-	switch {
-	case x == nil || y == nil:
-		return nil // ∅ ∩ y == ∅ and ∩ ∅ == ∅
-	case x.typ == nil:
-		return y // 𝓤 ∩ y == y
-	case y.typ == nil:
-		return x // x ∩ 𝓤 == x
-	}
-	// ∅ ⊂ x, y ⊂ 𝓤
-
-	if x.disjoint(y) {
-		return nil // x ∩ y == ∅ if x ∩ y == ∅
-	}
-	// x.typ == y.typ
-
-	// ~t ∩ ~t == ~t
-	// ~t ∩  T ==  T
-	//  T ∩ ~t ==  T
-	//  T ∩  T ==  T
-	if !x.tilde || y.tilde {
-		return x
-	}
-	return y
-}
-
-// includes reports whether t ∈ x.
-func (x *term) includes(t types.Type) bool {
-	// easy cases
-	switch {
-	case x == nil:
-		return false // t ∈ ∅ == false
-	case x.typ == nil:
-		return true // t ∈ 𝓤 == true
-	}
-	// ∅ ⊂ x ⊂ 𝓤
-
-	u := t
-	if x.tilde {
-		u = under(u)
-	}
-	return types.Identical(x.typ, u)
-}
-
-// subsetOf reports whether x ⊆ y.
-func (x *term) subsetOf(y *term) bool {
-	// easy cases
-	switch {
-	case x == nil:
-		return true // ∅ ⊆ y == true
-	case y == nil:
-		return false // x ⊆ ∅ == false since x != ∅
-	case y.typ == nil:
-		return true // x ⊆ 𝓤 == true
-	case x.typ == nil:
-		return false // 𝓤 ⊆ y == false since y != 𝓤
-	}
-	// ∅ ⊂ x, y ⊂ 𝓤
-
-	if x.disjoint(y) {
-		return false // x ⊆ y == false if x ∩ y == ∅
-	}
-	// x.typ == y.typ
-
-	// ~t ⊆ ~t == true
-	// ~t ⊆ T == false
-	//  T ⊆ ~t == true
-	//  T ⊆  T == true
-	return !x.tilde || y.tilde
-}
-
-// disjoint reports whether x ∩ y == ∅.
-// x.typ and y.typ must not be nil.
-func (x *term) disjoint(y *term) bool {
-	if debug && (x.typ == nil || y.typ == nil) {
-		panic("invalid argument(s)")
-	}
-	ux := x.typ
-	if y.tilde {
-		ux = under(ux)
-	}
-	uy := y.typ
-	if x.tilde {
-		uy = under(uy)
-	}
-	return !types.Identical(ux, uy)
-}

vendor/golang.org/x/tools/internal/typesinternal/errorcode.go

@@ -167,7 +167,7 @@ const (
 	UntypedNilUse
 
 	// WrongAssignCount occurs when the number of values on the right-hand side
-	// of an assignment or or initialization expression does not match the number
+	// of an assignment or initialization expression does not match the number
 	// of variables on the left-hand side.
 	//
 	// Example:

vendor/golang.org/x/tools/internal/typesinternal/toonew.go

@@ -0,0 +1,89 @@
+// Copyright 2024 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 typesinternal
+
+import (
+	"go/types"
+
+	"golang.org/x/tools/internal/stdlib"
+	"golang.org/x/tools/internal/versions"
+)
+
+// TooNewStdSymbols computes the set of package-level symbols
+// exported by pkg that are not available at the specified version.
+// The result maps each symbol to its minimum version.
+//
+// The pkg is allowed to contain type errors.
+func TooNewStdSymbols(pkg *types.Package, version string) map[types.Object]string {
+	disallowed := make(map[types.Object]string)
+
+	// Pass 1: package-level symbols.
+	symbols := stdlib.PackageSymbols[pkg.Path()]
+	for _, sym := range symbols {
+		symver := sym.Version.String()
+		if versions.Before(version, symver) {
+			switch sym.Kind {
+			case stdlib.Func, stdlib.Var, stdlib.Const, stdlib.Type:
+				disallowed[pkg.Scope().Lookup(sym.Name)] = symver
+			}
+		}
+	}
+
+	// Pass 2: fields and methods.
+	//
+	// We allow fields and methods if their associated type is
+	// disallowed, as otherwise we would report false positives
+	// for compatibility shims. Consider:
+	//
+	//   //go:build go1.22
+	//   type T struct { F std.Real } // correct new API
+	//
+	//   //go:build !go1.22
+	//   type T struct { F fake } // shim
+	//   type fake struct { ... }
+	//   func (fake) M () {}
+	//
+	// These alternative declarations of T use either the std.Real
+	// type, introduced in go1.22, or a fake type, for the field
+	// F. (The fakery could be arbitrarily deep, involving more
+	// nested fields and methods than are shown here.) Clients
+	// that use the compatibility shim T will compile with any
+	// version of go, whether older or newer than go1.22, but only
+	// the newer version will use the std.Real implementation.
+	//
+	// Now consider a reference to method M in new(T).F.M() in a
+	// module that requires a minimum of go1.21. The analysis may
+	// occur using a version of Go higher than 1.21, selecting the
+	// first version of T, so the method M is Real.M. This would
+	// spuriously cause the analyzer to report a reference to a
+	// too-new symbol even though this expression compiles just
+	// fine (with the fake implementation) using go1.21.
+	for _, sym := range symbols {
+		symVersion := sym.Version.String()
+		if !versions.Before(version, symVersion) {
+			continue // allowed
+		}
+
+		var obj types.Object
+		switch sym.Kind {
+		case stdlib.Field:
+			typename, name := sym.SplitField()
+			if t := pkg.Scope().Lookup(typename); t != nil && disallowed[t] == "" {
+				obj, _, _ = types.LookupFieldOrMethod(t.Type(), false, pkg, name)
+			}
+
+		case stdlib.Method:
+			ptr, recvname, name := sym.SplitMethod()
+			if t := pkg.Scope().Lookup(recvname); t != nil && disallowed[t] == "" {
+				obj, _, _ = types.LookupFieldOrMethod(t.Type(), ptr, pkg, name)
+			}
+		}
+		if obj != nil {
+			disallowed[obj] = symVersion
+		}
+	}
+
+	return disallowed
+}

vendor/golang.org/x/tools/internal/typesinternal/types.go

@@ -48,5 +48,3 @@ func ReadGo116ErrorData(err types.Error) (code ErrorCode, start, end token.Pos,
 	}
 	return ErrorCode(data[0]), token.Pos(data[1]), token.Pos(data[2]), true
 }
-
-var SetGoVersion = func(conf *types.Config, version string) bool { return false }

vendor/golang.org/x/tools/internal/typesinternal/types_118.go

@@ -1,16 +0,0 @@
-// Copyright 2021 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 typesinternal
-
-import (
-	"go/types"
-)
-
-func init() {
-	SetGoVersion = func(conf *types.Config, version string) bool {
-		conf.GoVersion = version
-		return true
-	}
-}