X-Git-Url: https://git.josue.xyz/?a=blobdiff_plain;f=.config%2Fcoc%2Fextensions%2Fcoc-go-data%2Ftools%2Fpkg%2Fmod%2Fgolang.org%2Fx%2Ftools%40v0.0.0-20201105173854-bc9fc8d8c4bc%2Frefactor%2Frename%2Fcheck.go;fp=.config%2Fcoc%2Fextensions%2Fcoc-go-data%2Ftools%2Fpkg%2Fmod%2Fgolang.org%2Fx%2Ftools%40v0.0.0-20201105173854-bc9fc8d8c4bc%2Frefactor%2Frename%2Fcheck.go;h=0000000000000000000000000000000000000000;hb=3ddadb3c98564791f0ac36cb39771d844a63dc91;hp=838fc7b79e14b2f4d31b5f08fde1a09655180f67;hpb=5f797af6612ed10887189b47a1efc2f915586e59;p=dotfiles%2F.git

diff --git a/.config/coc/extensions/coc-go-data/tools/pkg/mod/golang.org/x/tools@v0.0.0-20201105173854-bc9fc8d8c4bc/refactor/rename/check.go b/.config/coc/extensions/coc-go-data/tools/pkg/mod/golang.org/x/tools@v0.0.0-20201105173854-bc9fc8d8c4bc/refactor/rename/check.go
deleted file mode 100644
index 838fc7b7..00000000
--- a/.config/coc/extensions/coc-go-data/tools/pkg/mod/golang.org/x/tools@v0.0.0-20201105173854-bc9fc8d8c4bc/refactor/rename/check.go
+++ /dev/null
@@ -1,858 +0,0 @@
-// Copyright 2014 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 rename
-
-// This file defines the safety checks for each kind of renaming.
-
-import (
-	"fmt"
-	"go/ast"
-	"go/token"
-	"go/types"
-
-	"golang.org/x/tools/go/loader"
-	"golang.org/x/tools/refactor/satisfy"
-)
-
-// errorf reports an error (e.g. conflict) and prevents file modification.
-func (r *renamer) errorf(pos token.Pos, format string, args ...interface{}) {
-	r.hadConflicts = true
-	reportError(r.iprog.Fset.Position(pos), fmt.Sprintf(format, args...))
-}
-
-// check performs safety checks of the renaming of the 'from' object to r.to.
-func (r *renamer) check(from types.Object) {
-	if r.objsToUpdate[from] {
-		return
-	}
-	r.objsToUpdate[from] = true
-
-	// NB: order of conditions is important.
-	if from_, ok := from.(*types.PkgName); ok {
-		r.checkInFileBlock(from_)
-	} else if from_, ok := from.(*types.Label); ok {
-		r.checkLabel(from_)
-	} else if isPackageLevel(from) {
-		r.checkInPackageBlock(from)
-	} else if v, ok := from.(*types.Var); ok && v.IsField() {
-		r.checkStructField(v)
-	} else if f, ok := from.(*types.Func); ok && recv(f) != nil {
-		r.checkMethod(f)
-	} else if isLocal(from) {
-		r.checkInLocalScope(from)
-	} else {
-		r.errorf(from.Pos(), "unexpected %s object %q (please report a bug)\n",
-			objectKind(from), from)
-	}
-}
-
-// checkInFileBlock performs safety checks for renames of objects in the file block,
-// i.e. imported package names.
-func (r *renamer) checkInFileBlock(from *types.PkgName) {
-	// Check import name is not "init".
-	if r.to == "init" {
-		r.errorf(from.Pos(), "%q is not a valid imported package name", r.to)
-	}
-
-	// Check for conflicts between file and package block.
-	if prev := from.Pkg().Scope().Lookup(r.to); prev != nil {
-		r.errorf(from.Pos(), "renaming this %s %q to %q would conflict",
-			objectKind(from), from.Name(), r.to)
-		r.errorf(prev.Pos(), "\twith this package member %s",
-			objectKind(prev))
-		return // since checkInPackageBlock would report redundant errors
-	}
-
-	// Check for conflicts in lexical scope.
-	r.checkInLexicalScope(from, r.packages[from.Pkg()])
-
-	// Finally, modify ImportSpec syntax to add or remove the Name as needed.
-	info, path, _ := r.iprog.PathEnclosingInterval(from.Pos(), from.Pos())
-	if from.Imported().Name() == r.to {
-		// ImportSpec.Name not needed
-		path[1].(*ast.ImportSpec).Name = nil
-	} else {
-		// ImportSpec.Name needed
-		if spec := path[1].(*ast.ImportSpec); spec.Name == nil {
-			spec.Name = &ast.Ident{NamePos: spec.Path.Pos(), Name: r.to}
-			info.Defs[spec.Name] = from
-		}
-	}
-}
-
-// 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)
-	}
-}
-
-func (r *renamer) checkInLocalScope(from types.Object) {
-	info := r.packages[from.Pkg()]
-
-	// Is this object an implicit local var for a type switch?
-	// Each case has its own var, whose position is the decl of y,
-	// but Ident in that decl does not appear in the Uses map.
-	//
-	//   switch y := x.(type) {	 // Defs[Ident(y)] is undefined
-	//   case int:    print(y)       // Implicits[CaseClause(int)]    = Var(y_int)
-	//   case string: print(y)       // Implicits[CaseClause(string)] = Var(y_string)
-	//   }
-	//
-	var isCaseVar bool
-	for syntax, obj := range info.Implicits {
-		if _, ok := syntax.(*ast.CaseClause); ok && obj.Pos() == from.Pos() {
-			isCaseVar = true
-			r.check(obj)
-		}
-	}
-
-	r.checkInLexicalScope(from, info)
-
-	// Finally, if this was a type switch, change the variable y.
-	if isCaseVar {
-		_, path, _ := r.iprog.PathEnclosingInterval(from.Pos(), from.Pos())
-		path[0].(*ast.Ident).Name = r.to // path is [Ident AssignStmt TypeSwitchStmt...]
-	}
-}
-
-// checkInLexicalScope performs safety checks that a renaming does not
-// change the lexical reference structure of the specified package.
-//
-// For objects in lexical scope, there are three kinds of conflicts:
-// same-, sub-, and super-block conflicts.  We will illustrate all three
-// using this example:
-//
-//	var x int
-//	var z int
-//
-//	func f(y int) {
-//		print(x)
-//		print(y)
-//	}
-//
-// Renaming x to z encounters a SAME-BLOCK CONFLICT, because an object
-// with the new name already exists, defined in the same lexical block
-// as the old object.
-//
-// Renaming x to y encounters a SUB-BLOCK CONFLICT, because there exists
-// a reference to x from within (what would become) a hole in its scope.
-// The definition of y in an (inner) sub-block would cast a shadow in
-// the scope of the renamed variable.
-//
-// Renaming y to x encounters a SUPER-BLOCK CONFLICT.  This is the
-// converse situation: there is an existing definition of the new name
-// (x) in an (enclosing) super-block, and the renaming would create a
-// hole in its scope, within which there exist references to it.  The
-// new name casts a shadow in scope of the existing definition of x in
-// the super-block.
-//
-// Removing the old name (and all references to it) is always safe, and
-// requires no checks.
-//
-func (r *renamer) checkInLexicalScope(from types.Object, info *loader.PackageInfo) {
-	b := from.Parent() // the block defining the 'from' object
-	if b != nil {
-		toBlock, to := b.LookupParent(r.to, from.Parent().End())
-		if toBlock == b {
-			// same-block conflict
-			r.errorf(from.Pos(), "renaming this %s %q to %q",
-				objectKind(from), from.Name(), r.to)
-			r.errorf(to.Pos(), "\tconflicts with %s in same block",
-				objectKind(to))
-			return
-		} else if toBlock != nil {
-			// Check for super-block conflict.
-			// The name r.to is defined in a superblock.
-			// Is that name referenced from within this block?
-			forEachLexicalRef(info, to, func(id *ast.Ident, block *types.Scope) bool {
-				_, obj := lexicalLookup(block, from.Name(), id.Pos())
-				if obj == from {
-					// super-block conflict
-					r.errorf(from.Pos(), "renaming this %s %q to %q",
-						objectKind(from), from.Name(), r.to)
-					r.errorf(id.Pos(), "\twould shadow this reference")
-					r.errorf(to.Pos(), "\tto the %s declared here",
-						objectKind(to))
-					return false // stop
-				}
-				return true
-			})
-		}
-	}
-
-	// Check for sub-block conflict.
-	// Is there an intervening definition of r.to between
-	// the block defining 'from' and some reference to it?
-	forEachLexicalRef(info, from, func(id *ast.Ident, block *types.Scope) bool {
-		// Find the block that defines the found reference.
-		// It may be an ancestor.
-		fromBlock, _ := lexicalLookup(block, from.Name(), id.Pos())
-
-		// See what r.to would resolve to in the same scope.
-		toBlock, to := lexicalLookup(block, r.to, id.Pos())
-		if to != nil {
-			// sub-block conflict
-			if deeper(toBlock, fromBlock) {
-				r.errorf(from.Pos(), "renaming this %s %q to %q",
-					objectKind(from), from.Name(), r.to)
-				r.errorf(id.Pos(), "\twould cause this reference to become shadowed")
-				r.errorf(to.Pos(), "\tby this intervening %s definition",
-					objectKind(to))
-				return false // stop
-			}
-		}
-		return true
-	})
-
-	// Renaming a type that is used as an embedded field
-	// requires renaming the field too. e.g.
-	// 	type T int // if we rename this to U..
-	// 	var s struct {T}
-	// 	print(s.T) // ...this must change too
-	if _, ok := from.(*types.TypeName); ok {
-		for id, obj := range info.Uses {
-			if obj == from {
-				if field := info.Defs[id]; field != nil {
-					r.check(field)
-				}
-			}
-		}
-	}
-}
-
-// lexicalLookup is like (*types.Scope).LookupParent but respects the
-// environment visible at pos.  It assumes the relative position
-// information is correct with each file.
-func lexicalLookup(block *types.Scope, name string, pos token.Pos) (*types.Scope, types.Object) {
-	for b := block; b != nil; b = b.Parent() {
-		obj := b.Lookup(name)
-		// The scope of a package-level object is the entire package,
-		// so ignore pos in that case.
-		// No analogous clause is needed for file-level objects
-		// since no reference can appear before an import decl.
-		if obj != nil && (b == obj.Pkg().Scope() || obj.Pos() < pos) {
-			return b, obj
-		}
-	}
-	return nil, nil
-}
-
-// deeper reports whether block x is lexically deeper than y.
-func deeper(x, y *types.Scope) bool {
-	if x == y || x == nil {
-		return false
-	} else if y == nil {
-		return true
-	} else {
-		return deeper(x.Parent(), y.Parent())
-	}
-}
-
-// forEachLexicalRef calls fn(id, block) for each identifier id in package
-// info that is a reference to obj in lexical scope.  block is the
-// lexical block enclosing the reference.  If fn returns false the
-// iteration is terminated and findLexicalRefs returns false.
-func forEachLexicalRef(info *loader.PackageInfo, obj types.Object, fn func(id *ast.Ident, block *types.Scope) bool) bool {
-	ok := true
-	var stack []ast.Node
-
-	var visit func(n ast.Node) bool
-	visit = func(n ast.Node) bool {
-		if n == nil {
-			stack = stack[:len(stack)-1] // pop
-			return false
-		}
-		if !ok {
-			return false // bail out
-		}
-
-		stack = append(stack, n) // push
-		switch n := n.(type) {
-		case *ast.Ident:
-			if info.Uses[n] == obj {
-				block := enclosingBlock(&info.Info, stack)
-				if !fn(n, block) {
-					ok = false
-				}
-			}
-			return visit(nil) // pop stack
-
-		case *ast.SelectorExpr:
-			// don't visit n.Sel
-			ast.Inspect(n.X, visit)
-			return visit(nil) // pop stack, don't descend
-
-		case *ast.CompositeLit:
-			// Handle recursion ourselves for struct literals
-			// so we don't visit field identifiers.
-			tv := info.Types[n]
-			if _, ok := deref(tv.Type).Underlying().(*types.Struct); ok {
-				if n.Type != nil {
-					ast.Inspect(n.Type, visit)
-				}
-				for _, elt := range n.Elts {
-					if kv, ok := elt.(*ast.KeyValueExpr); ok {
-						ast.Inspect(kv.Value, visit)
-					} else {
-						ast.Inspect(elt, visit)
-					}
-				}
-				return visit(nil) // pop stack, don't descend
-			}
-		}
-		return true
-	}
-
-	for _, f := range info.Files {
-		ast.Inspect(f, visit)
-		if len(stack) != 0 {
-			panic(stack)
-		}
-		if !ok {
-			break
-		}
-	}
-	return ok
-}
-
-// enclosingBlock returns the innermost block enclosing the specified
-// AST node, specified in the form of a path from the root of the file,
-// [file...n].
-func enclosingBlock(info *types.Info, stack []ast.Node) *types.Scope {
-	for i := range stack {
-		n := stack[len(stack)-1-i]
-		// For some reason, go/types always associates a
-		// function's scope with its FuncType.
-		// TODO(adonovan): feature or a bug?
-		switch f := n.(type) {
-		case *ast.FuncDecl:
-			n = f.Type
-		case *ast.FuncLit:
-			n = f.Type
-		}
-		if b := info.Scopes[n]; b != nil {
-			return b
-		}
-	}
-	panic("no Scope for *ast.File")
-}
-
-func (r *renamer) checkLabel(label *types.Label) {
-	// Check there are no identical labels in the function's label block.
-	// (Label blocks don't nest, so this is easy.)
-	if prev := label.Parent().Lookup(r.to); prev != nil {
-		r.errorf(label.Pos(), "renaming this label %q to %q", label.Name(), prev.Name())
-		r.errorf(prev.Pos(), "\twould conflict with this one")
-	}
-}
-
-// checkStructField checks that the field renaming will not cause
-// conflicts at its declaration, or ambiguity or changes to any selection.
-func (r *renamer) checkStructField(from *types.Var) {
-	// 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, r.to)
-		if len(indices) == 1 {
-			r.errorf(from.Pos(), "renaming this field %q to %q",
-				from.Name(), r.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() == r.to {
-				r.errorf(from.Pos(), "renaming this field %q to %q",
-					from.Name(), r.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(named.Obj())
-		} else if named, ok := deref(from.Type()).(*types.Named); ok {
-			r.check(named.Obj())
-		}
-	}
-
-	// Check integrity of existing (field and method) selections.
-	r.checkSelections(from)
-}
-
-// checkSelection checks that all uses and selections that resolve to
-// the specified object would continue to do so after the renaming.
-func (r *renamer) checkSelections(from types.Object) {
-	for pkg, info := range r.packages {
-		if id := someUse(info, from); id != nil {
-			if !r.checkExport(id, pkg, from) {
-				return
-			}
-		}
-
-		for syntax, sel := range info.Selections {
-			// There may be extant selections of only the old
-			// name or only the new name, so we must check both.
-			// (If neither, the renaming is sound.)
-			//
-			// In both cases, we wish to compare the lengths
-			// of the implicit field path (Selection.Index)
-			// to see if the renaming would change it.
-			//
-			// If a selection that resolves to 'from', when renamed,
-			// would yield a path of the same or shorter length,
-			// this indicates ambiguity or a changed referent,
-			// analogous to same- or sub-block lexical conflict.
-			//
-			// If a selection using the name 'to' would
-			// yield a path of the same or shorter length,
-			// this indicates ambiguity or shadowing,
-			// analogous to same- or super-block lexical conflict.
-
-			// TODO(adonovan): fix: derive from Types[syntax.X].Mode
-			// TODO(adonovan): test with pointer, value, addressable value.
-			isAddressable := true
-
-			if sel.Obj() == from {
-				if obj, indices, _ := types.LookupFieldOrMethod(sel.Recv(), isAddressable, from.Pkg(), r.to); obj != nil {
-					// Renaming this existing selection of
-					// 'from' may block access to an existing
-					// type member named 'to'.
-					delta := len(indices) - len(sel.Index())
-					if delta > 0 {
-						continue // no ambiguity
-					}
-					r.selectionConflict(from, delta, syntax, obj)
-					return
-				}
-
-			} else if sel.Obj().Name() == r.to {
-				if obj, indices, _ := types.LookupFieldOrMethod(sel.Recv(), isAddressable, from.Pkg(), from.Name()); obj == from {
-					// Renaming 'from' may cause this existing
-					// selection of the name 'to' to change
-					// its meaning.
-					delta := len(indices) - len(sel.Index())
-					if delta > 0 {
-						continue //  no ambiguity
-					}
-					r.selectionConflict(from, -delta, syntax, sel.Obj())
-					return
-				}
-			}
-		}
-	}
-}
-
-func (r *renamer) selectionConflict(from types.Object, delta int, syntax *ast.SelectorExpr, obj types.Object) {
-	r.errorf(from.Pos(), "renaming this %s %q to %q",
-		objectKind(from), from.Name(), r.to)
-
-	switch {
-	case delta < 0:
-		// analogous to sub-block conflict
-		r.errorf(syntax.Sel.Pos(),
-			"\twould change the referent of this selection")
-		r.errorf(obj.Pos(), "\tof this %s", objectKind(obj))
-	case delta == 0:
-		// analogous to same-block conflict
-		r.errorf(syntax.Sel.Pos(),
-			"\twould make this reference ambiguous")
-		r.errorf(obj.Pos(), "\twith this %s", objectKind(obj))
-	case delta > 0:
-		// analogous to super-block conflict
-		r.errorf(syntax.Sel.Pos(),
-			"\twould shadow this selection")
-		r.errorf(obj.Pos(), "\tof the %s declared here",
-			objectKind(obj))
-	}
-}
-
-// checkMethod performs safety checks for renaming a method.
-// There are three hazards:
-// - declaration conflicts
-// - selection ambiguity/changes
-// - entailed renamings of assignable concrete/interface types.
-//   We reject renamings initiated at concrete methods if it would
-//   change the assignability relation.  For renamings of abstract
-//   methods, we rename all methods transitively coupled to it via
-//   assignability.
-func (r *renamer) checkMethod(from *types.Func) {
-	// e.g. error.Error
-	if from.Pkg() == nil {
-		r.errorf(from.Pos(), "you cannot rename built-in method %s", from)
-		return
-	}
-
-	// ASSIGNABILITY: We reject renamings of concrete methods that
-	// would break a 'satisfy' constraint; but renamings of abstract
-	// methods are allowed to proceed, and we rename affected
-	// concrete and abstract methods as necessary.  It is the
-	// initial method that determines the policy.
-
-	// Check for conflict at point of declaration.
-	// Check to ensure preservation of assignability requirements.
-	R := recv(from).Type()
-	if isInterface(R) {
-		// Abstract method
-
-		// declaration
-		prev, _, _ := types.LookupFieldOrMethod(R, false, from.Pkg(), r.to)
-		if prev != nil {
-			r.errorf(from.Pos(), "renaming this interface method %q to %q",
-				from.Name(), r.to)
-			r.errorf(prev.Pos(), "\twould conflict with this method")
-			return
-		}
-
-		// Check all interfaces that embed this one for
-		// declaration conflicts too.
-		for _, info := range r.packages {
-			// Start with named interface types (better errors)
-			for _, obj := range info.Defs {
-				if obj, ok := obj.(*types.TypeName); ok && isInterface(obj.Type()) {
-					f, _, _ := types.LookupFieldOrMethod(
-						obj.Type(), false, from.Pkg(), from.Name())
-					if f == nil {
-						continue
-					}
-					t, _, _ := types.LookupFieldOrMethod(
-						obj.Type(), false, from.Pkg(), r.to)
-					if t == nil {
-						continue
-					}
-					r.errorf(from.Pos(), "renaming this interface method %q to %q",
-						from.Name(), r.to)
-					r.errorf(t.Pos(), "\twould conflict with this method")
-					r.errorf(obj.Pos(), "\tin named interface type %q", obj.Name())
-				}
-			}
-
-			// Now look at all literal interface types (includes named ones again).
-			for e, tv := range info.Types {
-				if e, ok := e.(*ast.InterfaceType); ok {
-					_ = e
-					_ = tv.Type.(*types.Interface)
-					// TODO(adonovan): implement same check as above.
-				}
-			}
-		}
-
-		// assignability
-		//
-		// Find the set of concrete or abstract methods directly
-		// coupled to abstract method 'from' by some
-		// satisfy.Constraint, and rename them too.
-		for key := range r.satisfy() {
-			// key = (lhs, rhs) where lhs is always an interface.
-
-			lsel := r.msets.MethodSet(key.LHS).Lookup(from.Pkg(), from.Name())
-			if lsel == nil {
-				continue
-			}
-			rmethods := r.msets.MethodSet(key.RHS)
-			rsel := rmethods.Lookup(from.Pkg(), from.Name())
-			if rsel == nil {
-				continue
-			}
-
-			// If both sides have a method of this name,
-			// and one of them is m, the other must be coupled.
-			var coupled *types.Func
-			switch from {
-			case lsel.Obj():
-				coupled = rsel.Obj().(*types.Func)
-			case rsel.Obj():
-				coupled = lsel.Obj().(*types.Func)
-			default:
-				continue
-			}
-
-			// We must treat concrete-to-interface
-			// constraints like an implicit selection C.f of
-			// each interface method I.f, and check that the
-			// renaming leaves the selection unchanged and
-			// unambiguous.
-			//
-			// Fun fact: the implicit selection of C.f
-			// 	type I interface{f()}
-			// 	type C struct{I}
-			// 	func (C) g()
-			//      var _ I = C{} // here
-			// yields abstract method I.f.  This can make error
-			// messages less than obvious.
-			//
-			if !isInterface(key.RHS) {
-				// The logic below was derived from checkSelections.
-
-				rtosel := rmethods.Lookup(from.Pkg(), r.to)
-				if rtosel != nil {
-					rto := rtosel.Obj().(*types.Func)
-					delta := len(rsel.Index()) - len(rtosel.Index())
-					if delta < 0 {
-						continue // no ambiguity
-					}
-
-					// TODO(adonovan): record the constraint's position.
-					keyPos := token.NoPos
-
-					r.errorf(from.Pos(), "renaming this method %q to %q",
-						from.Name(), r.to)
-					if delta == 0 {
-						// analogous to same-block conflict
-						r.errorf(keyPos, "\twould make the %s method of %s invoked via interface %s ambiguous",
-							r.to, key.RHS, key.LHS)
-						r.errorf(rto.Pos(), "\twith (%s).%s",
-							recv(rto).Type(), r.to)
-					} else {
-						// analogous to super-block conflict
-						r.errorf(keyPos, "\twould change the %s method of %s invoked via interface %s",
-							r.to, key.RHS, key.LHS)
-						r.errorf(coupled.Pos(), "\tfrom (%s).%s",
-							recv(coupled).Type(), r.to)
-						r.errorf(rto.Pos(), "\tto (%s).%s",
-							recv(rto).Type(), r.to)
-					}
-					return // one error is enough
-				}
-			}
-
-			if !r.changeMethods {
-				// This should be unreachable.
-				r.errorf(from.Pos(), "internal error: during renaming of abstract method %s", from)
-				r.errorf(coupled.Pos(), "\tchangedMethods=false, coupled method=%s", coupled)
-				r.errorf(from.Pos(), "\tPlease file a bug report")
-				return
-			}
-
-			// Rename the coupled method to preserve assignability.
-			r.check(coupled)
-		}
-	} else {
-		// Concrete method
-
-		// declaration
-		prev, indices, _ := types.LookupFieldOrMethod(R, true, from.Pkg(), r.to)
-		if prev != nil && len(indices) == 1 {
-			r.errorf(from.Pos(), "renaming this method %q to %q",
-				from.Name(), r.to)
-			r.errorf(prev.Pos(), "\twould conflict with this %s",
-				objectKind(prev))
-			return
-		}
-
-		// assignability
-		//
-		// Find the set of abstract methods coupled to concrete
-		// method 'from' by some satisfy.Constraint, and rename
-		// them too.
-		//
-		// Coupling may be indirect, e.g. I.f <-> C.f via type D.
-		//
-		// 	type I interface {f()}
-		//	type C int
-		//	type (C) f()
-		//	type D struct{C}
-		//	var _ I = D{}
-		//
-		for key := range r.satisfy() {
-			// key = (lhs, rhs) where lhs is always an interface.
-			if isInterface(key.RHS) {
-				continue
-			}
-			rsel := r.msets.MethodSet(key.RHS).Lookup(from.Pkg(), from.Name())
-			if rsel == nil || rsel.Obj() != from {
-				continue // rhs does not have the method
-			}
-			lsel := r.msets.MethodSet(key.LHS).Lookup(from.Pkg(), from.Name())
-			if lsel == nil {
-				continue
-			}
-			imeth := lsel.Obj().(*types.Func)
-
-			// imeth is the abstract method (e.g. I.f)
-			// and key.RHS is the concrete coupling type (e.g. D).
-			if !r.changeMethods {
-				r.errorf(from.Pos(), "renaming this method %q to %q",
-					from.Name(), r.to)
-				var pos token.Pos
-				var iface string
-
-				I := recv(imeth).Type()
-				if named, ok := I.(*types.Named); ok {
-					pos = named.Obj().Pos()
-					iface = "interface " + named.Obj().Name()
-				} else {
-					pos = from.Pos()
-					iface = I.String()
-				}
-				r.errorf(pos, "\twould make %s no longer assignable to %s",
-					key.RHS, iface)
-				r.errorf(imeth.Pos(), "\t(rename %s.%s if you intend to change both types)",
-					I, from.Name())
-				return // one error is enough
-			}
-
-			// Rename the coupled interface method to preserve assignability.
-			r.check(imeth)
-		}
-	}
-
-	// Check integrity of existing (field and method) selections.
-	// We skip this if there were errors above, to avoid redundant errors.
-	r.checkSelections(from)
-}
-
-func (r *renamer) checkExport(id *ast.Ident, pkg *types.Package, from types.Object) bool {
-	// Reject cross-package references if r.to is unexported.
-	// (Such references may be qualified identifiers or field/method
-	// selections.)
-	if !ast.IsExported(r.to) && pkg != from.Pkg() {
-		r.errorf(from.Pos(),
-			"renaming this %s %q to %q would make it unexported",
-			objectKind(from), from.Name(), r.to)
-		r.errorf(id.Pos(), "\tbreaking references from packages such as %q",
-			pkg.Path())
-		return false
-	}
-	return true
-}
-
-// satisfy returns the set of interface satisfaction constraints.
-func (r *renamer) satisfy() map[satisfy.Constraint]bool {
-	if r.satisfyConstraints == nil {
-		// Compute on demand: it's expensive.
-		var f satisfy.Finder
-		for _, info := range r.packages {
-			f.Find(&info.Info, info.Files)
-		}
-		r.satisfyConstraints = f.Result
-	}
-	return r.satisfyConstraints
-}
-
-// -- helpers ----------------------------------------------------------
-
-// recv returns the method's receiver.
-func recv(meth *types.Func) *types.Var {
-	return meth.Type().(*types.Signature).Recv()
-}
-
-// someUse returns an arbitrary use of obj within info.
-func someUse(info *loader.PackageInfo, obj types.Object) *ast.Ident {
-	for id, o := range info.Uses {
-		if o == obj {
-			return id
-		}
-	}
-	return nil
-}
-
-// -- Plundered from golang.org/x/tools/go/ssa -----------------
-
-func isInterface(T types.Type) bool { return types.IsInterface(T) }
-
-func deref(typ types.Type) types.Type {
-	if p, _ := typ.(*types.Pointer); p != nil {
-		return p.Elem()
-	}
-	return typ
-}