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compiler: remove unused packages

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This commit is contained in:
Li Jie
2025-01-08 23:02:46 +08:00
parent 2bc96ade33
commit 591dac8b41
9 changed files with 0 additions and 1359 deletions
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32
compiler/internal/aliases/aliases.go
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@@ -1,32 +0,0 @@
// 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 aliases
import (
"go/token"
"go/types"
)
// Package aliases defines backward compatible shims
// for the types.Alias type representation added in 1.22.
// This defines placeholders for x/tools until 1.26.
// NewAlias creates a new TypeName in Package pkg that
// is an alias for the type rhs.
//
// The enabled parameter determines whether the resulting [TypeName]'s
// type is an [types.Alias]. Its value must be the result of a call to
// [Enabled], which computes the effective value of
// GODEBUG=gotypesalias=... by invoking the type checker. The Enabled
// function is expensive and should be called once per task (e.g.
// package import), not once per call to NewAlias.
func NewAlias(enabled bool, pos token.Pos, pkg *types.Package, name string, rhs types.Type) *types.TypeName {
if enabled {
tname := types.NewTypeName(pos, pkg, name, nil)
newAlias(tname, rhs)
return tname
}
return types.NewTypeName(pos, pkg, name, rhs)
}

31
compiler/internal/aliases/aliases_go121.go
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@@ -1,31 +0,0 @@
// 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.
//go:build !go1.22
// +build !go1.22
package aliases
import (
"go/types"
)
// Alias is a placeholder for a go/types.Alias for <=1.21.
// It will never be created by go/types.
type Alias struct{}
func (*Alias) String() string { panic("unreachable") }
func (*Alias) Underlying() types.Type { panic("unreachable") }
func (*Alias) Obj() *types.TypeName { panic("unreachable") }
func Rhs(alias *Alias) types.Type { panic("unreachable") }
// Unalias returns the type t for go <=1.21.
func Unalias(t types.Type) types.Type { return t }
func newAlias(name *types.TypeName, rhs types.Type) *Alias { panic("unreachable") }
// Enabled reports whether [NewAlias] should create [types.Alias] types.
//
// Before go1.22, this function always returns false.
func Enabled() bool { return false }

63
compiler/internal/aliases/aliases_go122.go
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@@ -1,63 +0,0 @@
// 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.
//go:build go1.22
// +build go1.22
package aliases
import (
"go/ast"
"go/parser"
"go/token"
"go/types"
)
// Alias is an alias of types.Alias.
type Alias = types.Alias
// Rhs returns the type on the right-hand side of the alias declaration.
func Rhs(alias *Alias) types.Type {
if alias, ok := any(alias).(interface{ Rhs() types.Type }); ok {
return alias.Rhs() // go1.23+
}
// go1.22's Alias didn't have the Rhs method,
// so Unalias is the best we can do.
return Unalias(alias)
}
// Unalias is a wrapper of types.Unalias.
func Unalias(t types.Type) types.Type { return types.Unalias(t) }
// newAlias is an internal alias around types.NewAlias.
// Direct usage is discouraged as the moment.
// Try to use NewAlias instead.
func newAlias(tname *types.TypeName, rhs types.Type) *Alias {
a := types.NewAlias(tname, rhs)
// TODO(go.dev/issue/65455): Remove kludgy workaround to set a.actual as a side-effect.
Unalias(a)
return a
}
// Enabled reports whether [NewAlias] should create [types.Alias] types.
//
// This function is expensive! Call it sparingly.
func Enabled() bool {
// The only reliable way to compute the answer is to invoke go/types.
// We don't parse the GODEBUG environment variable, because
// (a) it's tricky to do so in a manner that is consistent
// with the godebug package; in particular, a simple
// substring check is not good enough. The value is a
// rightmost-wins list of options. But more importantly:
// (b) it is impossible to detect changes to the effective
// setting caused by os.Setenv("GODEBUG"), as happens in
// many tests. Therefore any attempt to cache the result
// is just incorrect.
fset := token.NewFileSet()
f, _ := parser.ParseFile(fset, "a.go", "package p; type A = int", 0)
pkg, _ := new(types.Config).Check("p", fset, []*ast.File{f}, nil)
_, enabled := pkg.Scope().Lookup("A").Type().(*types.Alias)
return enabled
}

48
compiler/internal/mod/mod.go
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@@ -1,48 +0,0 @@
/*
* Copyright (c) 2024 The GoPlus Authors (goplus.org). All rights reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package mod
import (
"path"
"path/filepath"
"github.com/goplus/mod"
"github.com/goplus/mod/gopmod"
)
// Module represents a Go module.
type Module = gopmod.Module
// Load loads a Go module from a directory.
func Load(dir string) (ret *Module, pkgPath string, err error) {
if dir, err = filepath.Abs(dir); err != nil {
return
}
_, gomod, err := mod.FindGoMod(dir)
if err != nil {
return
}
if ret, err = gopmod.LoadFrom(gomod, ""); err != nil {
return
}
relPath, err := filepath.Rel(ret.Root(), dir)
if err != nil {
return
}
pkgPath = path.Join(ret.Path(), filepath.ToSlash(relPath))
return
}

110
compiler/internal/projs/proj.go
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@@ -1,110 +0,0 @@
/*
* Copyright (c) 2024 The GoPlus Authors (goplus.org). All rights reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package projs
import (
"errors"
"path/filepath"
"syscall"
)
// -----------------------------------------------------------------------------
type Proj = interface {
projObj()
}
type FilesProj struct {
Files []string
}
type PkgPathProj struct {
Path string
}
type DirProj struct {
Dir string
}
func (p *FilesProj) projObj() {}
func (p *PkgPathProj) projObj() {}
func (p *DirProj) projObj() {}
// -----------------------------------------------------------------------------
func ParseOne(args ...string) (proj Proj, next []string, err error) {
if len(args) == 0 {
return nil, nil, syscall.ENOENT
}
arg := args[0]
if isFile(arg) {
n := 1
for n < len(args) && isFile(args[n]) {
n++
}
return &FilesProj{Files: args[:n]}, args[n:], nil
}
if isLocal(arg) {
return &DirProj{Dir: arg}, args[1:], nil
}
return &PkgPathProj{Path: arg}, args[1:], nil
}
func isFile(fname string) bool {
n := len(filepath.Ext(fname))
return n > 1
}
func isLocal(ns string) bool {
if len(ns) > 0 {
switch c := ns[0]; c {
case '/', '\\', '.':
return true
default:
return len(ns) >= 2 && ns[1] == ':' && ('A' <= c && c <= 'Z' || 'a' <= c && c <= 'z')
}
}
return false
}
// -----------------------------------------------------------------------------
func ParseAll(args ...string) (projs []Proj, err error) {
var hasFiles, hasNotFiles bool
for {
proj, next, e := ParseOne(args...)
if e != nil {
if hasFiles && hasNotFiles {
return nil, ErrMixedFilesProj
}
return
}
if _, ok := proj.(*FilesProj); ok {
hasFiles = true
} else {
hasNotFiles = true
}
projs = append(projs, proj)
args = next
}
}
var (
ErrMixedFilesProj = errors.New("mixed files project")
)
// -----------------------------------------------------------------------------

218
compiler/internal/typeparams/normalize.go
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@@ -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()
}

163
compiler/internal/typeparams/termlist.go
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@@ -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
}

169
compiler/internal/typeparams/typeterm.go
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@@ -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)
}

525
compiler/internal/typeutil/map.go
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@@ -1,525 +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 typeutil defines various utilities for types, such as Map,
// a mapping from types.Type to interface{} values.
package typeutil
import (
"bytes"
"fmt"
"go/types"
"reflect"
"github.com/goplus/llgo/compiler/internal/aliases"
"github.com/goplus/llgo/compiler/internal/typeparams"
)
// Map is a hash-table-based mapping from types (types.Type) to
// arbitrary interface{} values. The concrete types that implement
// the Type interface are pointers. Since they are not canonicalized,
// == cannot be used to check for equivalence, and thus we cannot
// simply use a Go map.
//
// Just as with map[K]V, a nil *Map is a valid empty map.
//
// Not thread-safe.
type Map struct {
hasher Hasher // shared by many Maps
table map[uint32][]entry // maps hash to bucket; entry.key==nil means unused
length int // number of map entries
}
// entry is an entry (key/value association) in a hash bucket.
type entry struct {
key types.Type
value interface{}
}
// SetHasher sets the hasher used by Map.
//
// All Hashers are functionally equivalent but contain internal state
// used to cache the results of hashing previously seen types.
//
// A single Hasher created by MakeHasher() may be shared among many
// Maps. This is recommended if the instances have many keys in
// common, as it will amortize the cost of hash computation.
//
// A Hasher may grow without bound as new types are seen. Even when a
// type is deleted from the map, the Hasher never shrinks, since other
// types in the map may reference the deleted type indirectly.
//
// Hashers are not thread-safe, and read-only operations such as
// Map.Lookup require updates to the hasher, so a full Mutex lock (not a
// read-lock) is require around all Map operations if a shared
// hasher is accessed from multiple threads.
//
// If SetHasher is not called, the Map will create a private hasher at
// the first call to Insert.
func (m *Map) SetHasher(hasher Hasher) {
m.hasher = hasher
}
// Delete removes the entry with the given key, if any.
// It returns true if the entry was found.
func (m *Map) Delete(key types.Type) bool {
if m != nil && m.table != nil {
hash := m.hasher.Hash(key)
bucket := m.table[hash]
for i, e := range bucket {
if e.key != nil && types.Identical(key, e.key) {
// We can't compact the bucket as it
// would disturb iterators.
bucket[i] = entry{}
m.length--
return true
}
}
}
return false
}
// At returns the map entry for the given key.
// The result is nil if the entry is not present.
func (m *Map) At(key types.Type) interface{} {
if m != nil && m.table != nil {
for _, e := range m.table[m.hasher.Hash(key)] {
if e.key != nil && types.Identical(key, e.key) {
return e.value
}
}
}
return nil
}
// Set sets the map entry for key to val,
// and returns the previous entry, if any.
func (m *Map) Set(key types.Type, value interface{}) (prev interface{}) {
if m.table != nil {
hash := m.hasher.Hash(key)
bucket := m.table[hash]
var hole *entry
for i, e := range bucket {
if e.key == nil {
hole = &bucket[i]
} else if types.Identical(key, e.key) {
prev = e.value
bucket[i].value = value
return
}
}
if hole != nil {
*hole = entry{key, value} // overwrite deleted entry
} else {
m.table[hash] = append(bucket, entry{key, value})
}
} else {
if m.hasher.memo == nil {
m.hasher = MakeHasher()
}
hash := m.hasher.Hash(key)
m.table = map[uint32][]entry{hash: {entry{key, value}}}
}
m.length++
return
}
// Len returns the number of map entries.
func (m *Map) Len() int {
if m != nil {
return m.length
}
return 0
}
// Iterate calls function f on each entry in the map in unspecified order.
//
// If f should mutate the map, Iterate provides the same guarantees as
// Go maps: if f deletes a map entry that Iterate has not yet reached,
// f will not be invoked for it, but if f inserts a map entry that
// Iterate has not yet reached, whether or not f will be invoked for
// it is unspecified.
func (m *Map) Iterate(f func(key types.Type, value interface{})) {
if m != nil {
for _, bucket := range m.table {
for _, e := range bucket {
if e.key != nil {
f(e.key, e.value)
}
}
}
}
}
// Keys returns a new slice containing the set of map keys.
// The order is unspecified.
func (m *Map) Keys() []types.Type {
keys := make([]types.Type, 0, m.Len())
m.Iterate(func(key types.Type, _ interface{}) {
keys = append(keys, key)
})
return keys
}
func (m *Map) toString(values bool) string {
if m == nil {
return "{}"
}
var buf bytes.Buffer
fmt.Fprint(&buf, "{")
sep := ""
m.Iterate(func(key types.Type, value interface{}) {
fmt.Fprint(&buf, sep)
sep = ", "
fmt.Fprint(&buf, key)
if values {
fmt.Fprintf(&buf, ": %q", value)
}
})
fmt.Fprint(&buf, "}")
return buf.String()
}
// String returns a string representation of the map's entries.
// Values are printed using fmt.Sprintf("%v", v).
// Order is unspecified.
func (m *Map) String() string {
return m.toString(true)
}
// KeysString returns a string representation of the map's key set.
// Order is unspecified.
func (m *Map) KeysString() string {
return m.toString(false)
}
////////////////////////////////////////////////////////////////////////
// Hasher
// A Hasher maps each type to its hash value.
// For efficiency, a hasher uses memoization; thus its memory
// footprint grows monotonically over time.
// Hashers are not thread-safe.
// Hashers have reference semantics.
// Call MakeHasher to create a Hasher.
type Hasher struct {
memo map[types.Type]uint32
// ptrMap records pointer identity.
ptrMap map[interface{}]uint32
// sigTParams holds type parameters from the signature being hashed.
// Signatures are considered identical modulo renaming of type parameters, so
// within the scope of a signature type the identity of the signature's type
// parameters is just their index.
//
// Since the language does not currently support referring to uninstantiated
// generic types or functions, and instantiated signatures do not have type
// parameter lists, we should never encounter a second non-empty type
// parameter list when hashing a generic signature.
sigTParams *types.TypeParamList
}
// MakeHasher returns a new Hasher instance.
func MakeHasher() Hasher {
return Hasher{
memo: make(map[types.Type]uint32),
ptrMap: make(map[interface{}]uint32),
sigTParams: nil,
}
}
// Hash computes a hash value for the given type t such that
// Identical(t, t') => Hash(t) == Hash(t').
func (h Hasher) Hash(t types.Type) uint32 {
hash, ok := h.memo[t]
if !ok {
hash = h.hashFor(t)
h.memo[t] = hash
}
return hash
}
// hashString computes the Fowler–Noll–Vo hash of s.
func hashString(s string) uint32 {
var h uint32
for i := 0; i < len(s); i++ {
h ^= uint32(s[i])
h *= 16777619
}
return h
}
func HashSig(h Hasher, t *types.Signature) uint32 {
var hash uint32 = 9091
if t.Variadic() {
hash *= 8863
}
// Use a separate hasher for types inside of the signature, where type
// parameter identity is modified to be (index, constraint). We must use a
// new memo for this hasher as type identity may be affected by this
// masking. For example, in func[T any](*T), the identity of *T depends on
// whether we are mapping the argument in isolation, or recursively as part
// of hashing the signature.
//
// We should never encounter a generic signature while hashing another
// generic signature, but defensively set sigTParams only if h.mask is
// unset.
tparams := t.TypeParams()
if h.sigTParams == nil && tparams.Len() != 0 {
h = Hasher{
// There may be something more efficient than discarding the existing
// memo, but it would require detecting whether types are 'tainted' by
// references to type parameters.
memo: make(map[types.Type]uint32),
// Re-using ptrMap ensures that pointer identity is preserved in this
// hasher.
ptrMap: h.ptrMap,
sigTParams: tparams,
}
}
for i := 0; i < tparams.Len(); i++ {
tparam := tparams.At(i)
hash += 7 * h.Hash(tparam.Constraint())
}
return hash + 3*h.hashTuple(t.Params()) + 5*h.hashTuple(t.Results())
}
// hashFor computes the hash of t.
func (h Hasher) hashFor(t types.Type) uint32 {
// See Identical for rationale.
switch t := t.(type) {
case *types.Basic:
return uint32(t.Kind())
case *aliases.Alias:
return h.Hash(t.Underlying())
case *types.Array:
return 9043 + 2*uint32(t.Len()) + 3*h.Hash(t.Elem())
case *types.Slice:
return 9049 + 2*h.Hash(t.Elem())
case *types.Struct:
var hash uint32 = 9059
for i, n := 0, t.NumFields(); i < n; i++ {
f := t.Field(i)
if f.Anonymous() {
hash += 8861
}
hash += hashString(t.Tag(i))
hash += hashString(f.Name()) // (ignore f.Pkg)
hash += h.Hash(f.Type())
}
return hash
case *types.Pointer:
return 9067 + 2*h.Hash(t.Elem())
case *types.Signature:
return HashSig(h, t)
case *types.Union:
return h.hashUnion(t)
case *types.Interface:
// Interfaces are identical if they have the same set of methods, with
// identical names and types, and they have the same set of type
// restrictions. See go/types.identical for more details.
var hash uint32 = 9103
// Hash methods.
for i, n := 0, t.NumMethods(); i < n; i++ {
// Method order is not significant.
// Ignore m.Pkg().
m := t.Method(i)
// Use shallow hash on method signature to
// avoid anonymous interface cycles.
hash += 3*hashString(m.Name()) + 5*h.shallowHash(m.Type())
}
// Hash type restrictions.
terms, err := typeparams.InterfaceTermSet(t)
// if err != nil t has invalid type restrictions.
if err == nil {
hash += h.hashTermSet(terms)
}
return hash
case *types.Map:
return 9109 + 2*h.Hash(t.Key()) + 3*h.Hash(t.Elem())
case *types.Chan:
return 9127 + 2*uint32(t.Dir()) + 3*h.Hash(t.Elem())
case *types.Named:
hash := h.hashPtr(t.Obj())
targs := t.TypeArgs()
for i := 0; i < targs.Len(); i++ {
targ := targs.At(i)
hash += 2 * h.Hash(targ)
}
return hash
case *types.TypeParam:
return h.hashTypeParam(t)
case *types.Tuple:
return h.hashTuple(t)
case interface{ Hash(h Hasher) uint32 }:
return t.Hash(h)
}
panic(fmt.Sprintf("%T: %v", t, t))
}
func (h Hasher) hashTuple(tuple *types.Tuple) uint32 {
// See go/types.identicalTypes for rationale.
n := tuple.Len()
hash := 9137 + 2*uint32(n)
for i := 0; i < n; i++ {
hash += 3 * h.Hash(tuple.At(i).Type())
}
return hash
}
func (h Hasher) hashUnion(t *types.Union) uint32 {
// Hash type restrictions.
terms, err := typeparams.UnionTermSet(t)
// if err != nil t has invalid type restrictions. Fall back on a non-zero
// hash.
if err != nil {
return 9151
}
return h.hashTermSet(terms)
}
func (h Hasher) hashTermSet(terms []*types.Term) uint32 {
hash := 9157 + 2*uint32(len(terms))
for _, term := range terms {
// term order is not significant.
termHash := h.Hash(term.Type())
if term.Tilde() {
termHash *= 9161
}
hash += 3 * termHash
}
return hash
}
// hashTypeParam returns a hash of the type parameter t, with a hash value
// depending on whether t is contained in h.sigTParams.
//
// If h.sigTParams is set and contains t, then we are in the process of hashing
// a signature, and the hash value of t must depend only on t's index and
// constraint: signatures are considered identical modulo type parameter
// renaming. To avoid infinite recursion, we only hash the type parameter
// index, and rely on types.Identical to handle signatures where constraints
// are not identical.
//
// Otherwise the hash of t depends only on t's pointer identity.
func (h Hasher) hashTypeParam(t *types.TypeParam) uint32 {
if h.sigTParams != nil {
i := t.Index()
if i >= 0 && i < h.sigTParams.Len() && t == h.sigTParams.At(i) {
return 9173 + 3*uint32(i)
}
}
return h.hashPtr(t.Obj())
}
// hashPtr hashes the pointer identity of ptr. It uses h.ptrMap to ensure that
// pointers values are not dependent on the GC.
func (h Hasher) hashPtr(ptr interface{}) uint32 {
if hash, ok := h.ptrMap[ptr]; ok {
return hash
}
hash := uint32(reflect.ValueOf(ptr).Pointer())
h.ptrMap[ptr] = hash
return hash
}
// shallowHash computes a hash of t without looking at any of its
// element Types, to avoid potential anonymous cycles in the types of
// interface methods.
//
// When an unnamed non-empty interface type appears anywhere among the
// arguments or results of an interface method, there is a potential
// for endless recursion. Consider:
//
// type X interface { m() []*interface { X } }
//
// The problem is that the Methods of the interface in m's result type
// include m itself; there is no mention of the named type X that
// might help us break the cycle.
// (See comment in go/types.identical, case *Interface, for more.)
func (h Hasher) shallowHash(t types.Type) uint32 {
// t is the type of an interface method (Signature),
// its params or results (Tuples), or their immediate
// elements (mostly Slice, Pointer, Basic, Named),
// so there's no need to optimize anything else.
switch t := t.(type) {
case *aliases.Alias:
return h.shallowHash(t.Underlying())
case *types.Signature:
var hash uint32 = 604171
if t.Variadic() {
hash *= 971767
}
// The Signature/Tuple recursion is always finite
// and invariably shallow.
return hash + 1062599*h.shallowHash(t.Params()) + 1282529*h.shallowHash(t.Results())
case *types.Tuple:
n := t.Len()
hash := 9137 + 2*uint32(n)
for i := 0; i < n; i++ {
hash += 53471161 * h.shallowHash(t.At(i).Type())
}
return hash
case *types.Basic:
return 45212177 * uint32(t.Kind())
case *types.Array:
return 1524181 + 2*uint32(t.Len())
case *types.Slice:
return 2690201
case *types.Struct:
return 3326489
case *types.Pointer:
return 4393139
case *types.Union:
return 562448657
case *types.Interface:
return 2124679 // no recursion here
case *types.Map:
return 9109
case *types.Chan:
return 9127
case *types.Named:
return h.hashPtr(t.Obj())
case *types.TypeParam:
return h.hashPtr(t.Obj())
}
panic(fmt.Sprintf("shallowHash: %T: %v", t, t))
}