newf.Dcl = make([]*ir.Name, len(gf.Dcl))
for i, n := range gf.Dcl {
- newf.Dcl[i] = subst.node(n).(*ir.Name)
+ newf.Dcl[i] = subst.localvar(n)
}
// Replace the types in the function signature.
return newf
}
-// node is like DeepCopy(), but creates distinct ONAME nodes, and also descends
-// into closures. It substitutes type arguments for type parameters in all the new
-// nodes.
+// localvar creates a new name node for the specified local variable and enters it
+// in subst.vars. It substitutes type arguments for type parameters in the type of
+// name as needed.
+func (subst *subster) localvar(name *ir.Name) *ir.Name {
+ m := ir.NewNameAt(name.Pos(), name.Sym())
+ if name.IsClosureVar() {
+ m.SetIsClosureVar(true)
+ }
+ m.SetType(subst.typ(name.Type()))
+ m.BuiltinOp = name.BuiltinOp
+ m.Curfn = subst.newf
+ m.Class = name.Class
+ assert(name.Class != ir.PEXTERN && name.Class != ir.PFUNC)
+ m.Func = name.Func
+ subst.vars[name] = m
+ m.SetTypecheck(1)
+ return m
+}
+
+// node is like DeepCopy(), but substitutes ONAME nodes based on subst.vars, and
+// also descends into closures. It substitutes type arguments for type parameters
+// in all the new nodes.
func (subst *subster) node(n ir.Node) ir.Node {
// Use closure to capture all state needed by the ir.EditChildren argument.
var edit func(ir.Node) ir.Node
return ir.TypeNode(subst.typ(x.Type()))
case ir.ONAME:
- name := x.(*ir.Name)
- if v := subst.vars[name]; v != nil {
+ if v := subst.vars[x.(*ir.Name)]; v != nil {
return v
}
- m := ir.NewNameAt(name.Pos(), name.Sym())
- if name.IsClosureVar() {
- m.SetIsClosureVar(true)
- }
- t := x.Type()
- if t == nil {
- assert(name.BuiltinOp != 0)
- } else {
- newt := subst.typ(t)
- m.SetType(newt)
- }
- m.BuiltinOp = name.BuiltinOp
- m.Curfn = subst.newf
- m.Class = name.Class
- m.Func = name.Func
- subst.vars[name] = m
- m.SetTypecheck(1)
- return m
+ return x
case ir.OLITERAL, ir.ONIL:
if x.Sym() != nil {
return x
func (subst *subster) namelist(l []*ir.Name) []*ir.Name {
s := make([]*ir.Name, len(l))
for i, n := range l {
- s[i] = subst.node(n).(*ir.Name)
+ s[i] = subst.localvar(n)
if n.Defn != nil {
s[i].Defn = subst.node(n.Defn)
}
func main() {
TestList()
+ TestExtending()
+ TestRemove()
+ TestIssue4103()
+ TestIssue6349()
+ TestMove()
+ TestZeroList()
+ TestInsertBeforeUnknownMark()
+ TestInsertAfterUnknownMark()
+ TestTransform()
}
--- /dev/null
+// 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 a
+
+import (
+ "fmt"
+)
+
+// Element is an element of a linked list.
+type Element[T any] struct {
+ // Next and previous pointers in the doubly-linked list of elements.
+ // To simplify the implementation, internally a list l is implemented
+ // as a ring, such that &l.root is both the next element of the last
+ // list element (l.Back()) and the previous element of the first list
+ // element (l.Front()).
+ next, prev *Element[T]
+
+ // The list to which this element belongs.
+ list *List[T]
+
+ // The value stored with this element.
+ Value T
+}
+
+// Next returns the next list element or nil.
+func (e *Element[T]) Next() *Element[T] {
+ if p := e.next; e.list != nil && p != &e.list.root {
+ return p
+ }
+ return nil
+}
+
+// Prev returns the previous list element or nil.
+func (e *Element[T]) Prev() *Element[T] {
+ if p := e.prev; e.list != nil && p != &e.list.root {
+ return p
+ }
+ return nil
+}
+
+// List represents a doubly linked list.
+// The zero value for List is an empty list ready to use.
+type List[T any] struct {
+ root Element[T] // sentinel list element, only &root, root.prev, and root.next are used
+ len int // current list length excluding (this) sentinel element
+}
+
+// Init initializes or clears list l.
+func (l *List[T]) Init() *List[T] {
+ l.root.next = &l.root
+ l.root.prev = &l.root
+ l.len = 0
+ return l
+}
+
+// New returns an initialized list.
+func New[T any]() *List[T] { return new(List[T]).Init() }
+
+// Len returns the number of elements of list l.
+// The complexity is O(1).
+func (l *List[_]) Len() int { return l.len }
+
+// Front returns the first element of list l or nil if the list is empty.
+func (l *List[T]) Front() *Element[T] {
+ if l.len == 0 {
+ return nil
+ }
+ return l.root.next
+}
+
+// Back returns the last element of list l or nil if the list is empty.
+func (l *List[T]) Back() *Element[T] {
+ if l.len == 0 {
+ return nil
+ }
+ return l.root.prev
+}
+
+// lazyInit lazily initializes a zero List value.
+func (l *List[_]) lazyInit() {
+ if l.root.next == nil {
+ l.Init()
+ }
+}
+
+// insert inserts e after at, increments l.len, and returns e.
+func (l *List[T]) insert(e, at *Element[T]) *Element[T] {
+ e.prev = at
+ e.next = at.next
+ e.prev.next = e
+ e.next.prev = e
+ e.list = l
+ l.len++
+ return e
+}
+
+// insertValue is a convenience wrapper for insert(&Element[T]{Value: v}, at).
+func (l *List[T]) insertValue(v T, at *Element[T]) *Element[T] {
+ return l.insert(&Element[T]{Value: v}, at)
+}
+
+// remove removes e from its list, decrements l.len, and returns e.
+func (l *List[T]) remove(e *Element[T]) *Element[T] {
+ e.prev.next = e.next
+ e.next.prev = e.prev
+ e.next = nil // avoid memory leaks
+ e.prev = nil // avoid memory leaks
+ e.list = nil
+ l.len--
+ return e
+}
+
+// move moves e to next to at and returns e.
+func (l *List[T]) move(e, at *Element[T]) *Element[T] {
+ if e == at {
+ return e
+ }
+ e.prev.next = e.next
+ e.next.prev = e.prev
+
+ e.prev = at
+ e.next = at.next
+ e.prev.next = e
+ e.next.prev = e
+
+ return e
+}
+
+// Remove removes e from l if e is an element of list l.
+// It returns the element value e.Value.
+// The element must not be nil.
+func (l *List[T]) Remove(e *Element[T]) T {
+ if e.list == l {
+ // if e.list == l, l must have been initialized when e was inserted
+ // in l or l == nil (e is a zero Element) and l.remove will crash
+ l.remove(e)
+ }
+ return e.Value
+}
+
+// PushFront inserts a new element e with value v at the front of list l and returns e.
+func (l *List[T]) PushFront(v T) *Element[T] {
+ l.lazyInit()
+ return l.insertValue(v, &l.root)
+}
+
+// PushBack inserts a new element e with value v at the back of list l and returns e.
+func (l *List[T]) PushBack(v T) *Element[T] {
+ l.lazyInit()
+ return l.insertValue(v, l.root.prev)
+}
+
+// InsertBefore inserts a new element e with value v immediately before mark and returns e.
+// If mark is not an element of l, the list is not modified.
+// The mark must not be nil.
+func (l *List[T]) InsertBefore(v T, mark *Element[T]) *Element[T] {
+ if mark.list != l {
+ return nil
+ }
+ // see comment in List.Remove about initialization of l
+ return l.insertValue(v, mark.prev)
+}
+
+// InsertAfter inserts a new element e with value v immediately after mark and returns e.
+// If mark is not an element of l, the list is not modified.
+// The mark must not be nil.
+func (l *List[T]) InsertAfter(v T, mark *Element[T]) *Element[T] {
+ if mark.list != l {
+ return nil
+ }
+ // see comment in List.Remove about initialization of l
+ return l.insertValue(v, mark)
+}
+
+// MoveToFront moves element e to the front of list l.
+// If e is not an element of l, the list is not modified.
+// The element must not be nil.
+func (l *List[T]) MoveToFront(e *Element[T]) {
+ if e.list != l || l.root.next == e {
+ return
+ }
+ // see comment in List.Remove about initialization of l
+ l.move(e, &l.root)
+}
+
+// MoveToBack moves element e to the back of list l.
+// If e is not an element of l, the list is not modified.
+// The element must not be nil.
+func (l *List[T]) MoveToBack(e *Element[T]) {
+ if e.list != l || l.root.prev == e {
+ return
+ }
+ // see comment in List.Remove about initialization of l
+ l.move(e, l.root.prev)
+}
+
+// MoveBefore moves element e to its new position before mark.
+// If e or mark is not an element of l, or e == mark, the list is not modified.
+// The element and mark must not be nil.
+func (l *List[T]) MoveBefore(e, mark *Element[T]) {
+ if e.list != l || e == mark || mark.list != l {
+ return
+ }
+ l.move(e, mark.prev)
+}
+
+// MoveAfter moves element e to its new position after mark.
+// If e or mark is not an element of l, or e == mark, the list is not modified.
+// The element and mark must not be nil.
+func (l *List[T]) MoveAfter(e, mark *Element[T]) {
+ if e.list != l || e == mark || mark.list != l {
+ return
+ }
+ l.move(e, mark)
+}
+
+// PushBackList inserts a copy of an other list at the back of list l.
+// The lists l and other may be the same. They must not be nil.
+func (l *List[T]) PushBackList(other *List[T]) {
+ l.lazyInit()
+ for i, e := other.Len(), other.Front(); i > 0; i, e = i-1, e.Next() {
+ l.insertValue(e.Value, l.root.prev)
+ }
+}
+
+// PushFrontList inserts a copy of an other list at the front of list l.
+// The lists l and other may be the same. They must not be nil.
+func (l *List[T]) PushFrontList(other *List[T]) {
+ l.lazyInit()
+ for i, e := other.Len(), other.Back(); i > 0; i, e = i-1, e.Prev() {
+ l.insertValue(e.Value, &l.root)
+ }
+}
+
+// Transform runs a transform function on a list returning a new list.
+func Transform[TElem1, TElem2 any](lst *List[TElem1], f func(TElem1) TElem2) *List[TElem2] {
+ ret := New[TElem2]()
+ for p := lst.Front(); p != nil; p = p.Next() {
+ ret.PushBack(f(p.Value))
+ }
+ return ret
+}
+
+func CheckListLen[T any](l *List[T], len int) bool {
+ if n := l.Len(); n != len {
+ panic(fmt.Sprintf("l.Len() = %d, want %d", n, len))
+ return false
+ }
+ return true
+}
+
+func CheckListPointers[T any](l *List[T], es []*Element[T]) {
+ root := &l.root
+
+ if !CheckListLen(l, len(es)) {
+ return
+ }
+
+ // zero length lists must be the zero value or properly initialized (sentinel circle)
+ if len(es) == 0 {
+ if l.root.next != nil && l.root.next != root || l.root.prev != nil && l.root.prev != root {
+ panic(fmt.Sprintf("l.root.next = %p, l.root.prev = %p; both should both be nil or %p", l.root.next, l.root.prev, root))
+ }
+ return
+ }
+ // len(es) > 0
+
+ // check internal and external prev/next connections
+ for i, e := range es {
+ prev := root
+ Prev := (*Element[T])(nil)
+ if i > 0 {
+ prev = es[i-1]
+ Prev = prev
+ }
+ if p := e.prev; p != prev {
+ panic(fmt.Sprintf("elt[%d](%p).prev = %p, want %p", i, e, p, prev))
+ }
+ if p := e.Prev(); p != Prev {
+ panic(fmt.Sprintf("elt[%d](%p).Prev() = %p, want %p", i, e, p, Prev))
+ }
+
+ next := root
+ Next := (*Element[T])(nil)
+ if i < len(es)-1 {
+ next = es[i+1]
+ Next = next
+ }
+ if n := e.next; n != next {
+ panic(fmt.Sprintf("elt[%d](%p).next = %p, want %p", i, e, n, next))
+ }
+ if n := e.Next(); n != Next {
+ panic(fmt.Sprintf("elt[%d](%p).Next() = %p, want %p", i, e, n, Next))
+ }
+ }
+}
--- /dev/null
+// 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 main
+
+import (
+ "a"
+ "fmt"
+ "strconv"
+)
+
+func TestList() {
+ l := a.New[string]()
+ a.CheckListPointers(l, []*(a.Element[string]){})
+
+ // Single element list
+ e := l.PushFront("a")
+ a.CheckListPointers(l, []*(a.Element[string]){e})
+ l.MoveToFront(e)
+ a.CheckListPointers(l, []*(a.Element[string]){e})
+ l.MoveToBack(e)
+ a.CheckListPointers(l, []*(a.Element[string]){e})
+ l.Remove(e)
+ a.CheckListPointers(l, []*(a.Element[string]){})
+
+ // Bigger list
+ l2 := a.New[int]()
+ e2 := l2.PushFront(2)
+ e1 := l2.PushFront(1)
+ e3 := l2.PushBack(3)
+ e4 := l2.PushBack(600)
+ a.CheckListPointers(l2, []*(a.Element[int]){e1, e2, e3, e4})
+
+ l2.Remove(e2)
+ a.CheckListPointers(l2, []*(a.Element[int]){e1, e3, e4})
+
+ l2.MoveToFront(e3) // move from middle
+ a.CheckListPointers(l2, []*(a.Element[int]){e3, e1, e4})
+
+ l2.MoveToFront(e1)
+ l2.MoveToBack(e3) // move from middle
+ a.CheckListPointers(l2, []*(a.Element[int]){e1, e4, e3})
+
+ l2.MoveToFront(e3) // move from back
+ a.CheckListPointers(l2, []*(a.Element[int]){e3, e1, e4})
+ l2.MoveToFront(e3) // should be no-op
+ a.CheckListPointers(l2, []*(a.Element[int]){e3, e1, e4})
+
+ l2.MoveToBack(e3) // move from front
+ a.CheckListPointers(l2, []*(a.Element[int]){e1, e4, e3})
+ l2.MoveToBack(e3) // should be no-op
+ a.CheckListPointers(l2, []*(a.Element[int]){e1, e4, e3})
+
+ e2 = l2.InsertBefore(2, e1) // insert before front
+ a.CheckListPointers(l2, []*(a.Element[int]){e2, e1, e4, e3})
+ l2.Remove(e2)
+ e2 = l2.InsertBefore(2, e4) // insert before middle
+ a.CheckListPointers(l2, []*(a.Element[int]){e1, e2, e4, e3})
+ l2.Remove(e2)
+ e2 = l2.InsertBefore(2, e3) // insert before back
+ a.CheckListPointers(l2, []*(a.Element[int]){e1, e4, e2, e3})
+ l2.Remove(e2)
+
+ e2 = l2.InsertAfter(2, e1) // insert after front
+ a.CheckListPointers(l2, []*(a.Element[int]){e1, e2, e4, e3})
+ l2.Remove(e2)
+ e2 = l2.InsertAfter(2, e4) // insert after middle
+ a.CheckListPointers(l2, []*(a.Element[int]){e1, e4, e2, e3})
+ l2.Remove(e2)
+ e2 = l2.InsertAfter(2, e3) // insert after back
+ a.CheckListPointers(l2, []*(a.Element[int]){e1, e4, e3, e2})
+ l2.Remove(e2)
+
+ // Check standard iteration.
+ sum := 0
+ for e := l2.Front(); e != nil; e = e.Next() {
+ sum += e.Value
+ }
+ if sum != 604 {
+ panic(fmt.Sprintf("sum over l = %d, want 604", sum))
+ }
+
+ // Clear all elements by iterating
+ var next *a.Element[int]
+ for e := l2.Front(); e != nil; e = next {
+ next = e.Next()
+ l2.Remove(e)
+ }
+ a.CheckListPointers(l2, []*(a.Element[int]){})
+}
+
+func checkList[T comparable](l *a.List[T], es []interface{}) {
+ if !a.CheckListLen(l, len(es)) {
+ return
+ }
+
+ i := 0
+ for e := l.Front(); e != nil; e = e.Next() {
+ le := e.Value
+ // Comparison between a generically-typed variable le and an interface.
+ if le != es[i] {
+ panic(fmt.Sprintf("elt[%d].Value = %v, want %v", i, le, es[i]))
+ }
+ i++
+ }
+}
+
+func TestExtending() {
+ l1 := a.New[int]()
+ l2 := a.New[int]()
+
+ l1.PushBack(1)
+ l1.PushBack(2)
+ l1.PushBack(3)
+
+ l2.PushBack(4)
+ l2.PushBack(5)
+
+ l3 := a.New[int]()
+ l3.PushBackList(l1)
+ checkList(l3, []interface{}{1, 2, 3})
+ l3.PushBackList(l2)
+ checkList(l3, []interface{}{1, 2, 3, 4, 5})
+
+ l3 = a.New[int]()
+ l3.PushFrontList(l2)
+ checkList(l3, []interface{}{4, 5})
+ l3.PushFrontList(l1)
+ checkList(l3, []interface{}{1, 2, 3, 4, 5})
+
+ checkList(l1, []interface{}{1, 2, 3})
+ checkList(l2, []interface{}{4, 5})
+
+ l3 = a.New[int]()
+ l3.PushBackList(l1)
+ checkList(l3, []interface{}{1, 2, 3})
+ l3.PushBackList(l3)
+ checkList(l3, []interface{}{1, 2, 3, 1, 2, 3})
+
+ l3 = a.New[int]()
+ l3.PushFrontList(l1)
+ checkList(l3, []interface{}{1, 2, 3})
+ l3.PushFrontList(l3)
+ checkList(l3, []interface{}{1, 2, 3, 1, 2, 3})
+
+ l3 = a.New[int]()
+ l1.PushBackList(l3)
+ checkList(l1, []interface{}{1, 2, 3})
+ l1.PushFrontList(l3)
+ checkList(l1, []interface{}{1, 2, 3})
+}
+
+func TestRemove() {
+ l := a.New[int]()
+ e1 := l.PushBack(1)
+ e2 := l.PushBack(2)
+ a.CheckListPointers(l, []*(a.Element[int]){e1, e2})
+ e := l.Front()
+ l.Remove(e)
+ a.CheckListPointers(l, []*(a.Element[int]){e2})
+ l.Remove(e)
+ a.CheckListPointers(l, []*(a.Element[int]){e2})
+}
+
+func TestIssue4103() {
+ l1 := a.New[int]()
+ l1.PushBack(1)
+ l1.PushBack(2)
+
+ l2 := a.New[int]()
+ l2.PushBack(3)
+ l2.PushBack(4)
+
+ e := l1.Front()
+ l2.Remove(e) // l2 should not change because e is not an element of l2
+ if n := l2.Len(); n != 2 {
+ panic(fmt.Sprintf("l2.Len() = %d, want 2", n))
+ }
+
+ l1.InsertBefore(8, e)
+ if n := l1.Len(); n != 3 {
+ panic(fmt.Sprintf("l1.Len() = %d, want 3", n))
+ }
+}
+
+func TestIssue6349() {
+ l := a.New[int]()
+ l.PushBack(1)
+ l.PushBack(2)
+
+ e := l.Front()
+ l.Remove(e)
+ if e.Value != 1 {
+ panic(fmt.Sprintf("e.value = %d, want 1", e.Value))
+ }
+ if e.Next() != nil {
+ panic(fmt.Sprintf("e.Next() != nil"))
+ }
+ if e.Prev() != nil {
+ panic(fmt.Sprintf("e.Prev() != nil"))
+ }
+}
+
+func TestMove() {
+ l := a.New[int]()
+ e1 := l.PushBack(1)
+ e2 := l.PushBack(2)
+ e3 := l.PushBack(3)
+ e4 := l.PushBack(4)
+
+ l.MoveAfter(e3, e3)
+ a.CheckListPointers(l, []*(a.Element[int]){e1, e2, e3, e4})
+ l.MoveBefore(e2, e2)
+ a.CheckListPointers(l, []*(a.Element[int]){e1, e2, e3, e4})
+
+ l.MoveAfter(e3, e2)
+ a.CheckListPointers(l, []*(a.Element[int]){e1, e2, e3, e4})
+ l.MoveBefore(e2, e3)
+ a.CheckListPointers(l, []*(a.Element[int]){e1, e2, e3, e4})
+
+ l.MoveBefore(e2, e4)
+ a.CheckListPointers(l, []*(a.Element[int]){e1, e3, e2, e4})
+ e2, e3 = e3, e2
+
+ l.MoveBefore(e4, e1)
+ a.CheckListPointers(l, []*(a.Element[int]){e4, e1, e2, e3})
+ e1, e2, e3, e4 = e4, e1, e2, e3
+
+ l.MoveAfter(e4, e1)
+ a.CheckListPointers(l, []*(a.Element[int]){e1, e4, e2, e3})
+ e2, e3, e4 = e4, e2, e3
+
+ l.MoveAfter(e2, e3)
+ a.CheckListPointers(l, []*(a.Element[int]){e1, e3, e2, e4})
+ e2, e3 = e3, e2
+}
+
+// Test PushFront, PushBack, PushFrontList, PushBackList with uninitialized a.List
+func TestZeroList() {
+ var l1 = new(a.List[int])
+ l1.PushFront(1)
+ checkList(l1, []interface{}{1})
+
+ var l2 = new(a.List[int])
+ l2.PushBack(1)
+ checkList(l2, []interface{}{1})
+
+ var l3 = new(a.List[int])
+ l3.PushFrontList(l1)
+ checkList(l3, []interface{}{1})
+
+ var l4 = new(a.List[int])
+ l4.PushBackList(l2)
+ checkList(l4, []interface{}{1})
+}
+
+// Test that a list l is not modified when calling InsertBefore with a mark that is not an element of l.
+func TestInsertBeforeUnknownMark() {
+ var l a.List[int]
+ l.PushBack(1)
+ l.PushBack(2)
+ l.PushBack(3)
+ l.InsertBefore(1, new(a.Element[int]))
+ checkList(&l, []interface{}{1, 2, 3})
+}
+
+// Test that a list l is not modified when calling InsertAfter with a mark that is not an element of l.
+func TestInsertAfterUnknownMark() {
+ var l a.List[int]
+ l.PushBack(1)
+ l.PushBack(2)
+ l.PushBack(3)
+ l.InsertAfter(1, new(a.Element[int]))
+ checkList(&l, []interface{}{1, 2, 3})
+}
+
+// Test that a list l is not modified when calling MoveAfter or MoveBefore with a mark that is not an element of l.
+func TestMoveUnknownMark() {
+ var l1 a.List[int]
+ e1 := l1.PushBack(1)
+
+ var l2 a.List[int]
+ e2 := l2.PushBack(2)
+
+ l1.MoveAfter(e1, e2)
+ checkList(&l1, []interface{}{1})
+ checkList(&l2, []interface{}{2})
+
+ l1.MoveBefore(e1, e2)
+ checkList(&l1, []interface{}{1})
+ checkList(&l2, []interface{}{2})
+}
+
+// Test the Transform function.
+func TestTransform() {
+ l1 := a.New[int]()
+ l1.PushBack(1)
+ l1.PushBack(2)
+ l2 := a.Transform(l1, strconv.Itoa)
+ checkList(l2, []interface{}{"1", "2"})
+}
+
+
+func main() {
+ TestList()
+ TestExtending()
+ TestRemove()
+ TestIssue4103()
+ TestIssue6349()
+ TestMove()
+ TestZeroList()
+ TestInsertBeforeUnknownMark()
+ TestInsertAfterUnknownMark()
+ TestTransform()
+}
--- /dev/null
+// rundir -G=3
+
+// 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 ignored