GoToSocial/vendor/modernc.org/ccgo/v3/lib/init.go

554 lines
15 KiB
Go

// Copyright 2020 The CCGO 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 ccgo // import "modernc.org/ccgo/v3/lib"
import (
"fmt"
"sort"
"strings"
"modernc.org/cc/v3"
)
func isAggregateTypeOrUnion(t cc.Type) bool {
switch t.Kind() {
case cc.Struct, cc.Union, cc.Array:
return true
}
return false
}
// 6.7.8 Initialization
func (p *project) initializer(f *function, n *cc.Initializer, t cc.Type, sc cc.StorageClass, tld *tld) {
lm := map[*cc.Initializer][]cc.StringID{}
tm := map[*cc.Initializer][]cc.StringID{}
s := p.initializerFlatten(n, lm, tm)
sort.Slice(s, func(i, j int) bool {
a := s[i]
b := s[j]
if a.Offset < b.Offset {
return true
}
if a.Offset > b.Offset {
return false
}
if a.Field == nil || b.Field == nil || !a.Field.IsBitField() || !b.Field.IsBitField() {
panic(todo("%v: internal error: off %#x, %v: off %#x, t %v", a.Position(), a.Offset, b.Position(), b.Offset, t))
}
return a.Field.BitFieldOffset() < b.Field.BitFieldOffset()
})
p.initializerInner("", 0, f, s, t, sc, tld, nil, lm, tm)
}
func (p *project) initializerInner(tag string, off uintptr, f *function, s []*cc.Initializer, t cc.Type, sc cc.StorageClass, tld *tld, patchField cc.Field, lm, tm map[*cc.Initializer][]cc.StringID) {
// 11: The initializer for a scalar shall be a single expression, optionally
// enclosed in braces. The initial value of the object is that of the
// expression (after conversion); the same type constraints and conversions as
// for simple assignment apply, taking the type of the scalar to be the
// unqualified version of its declared type.
if t.IsScalarType() && len(s) == 1 {
p.w("%s%s", tidyComment("", s[0]), tag)
switch {
case tld != nil && t.Kind() == cc.Ptr && s[0].AssignmentExpression.Operand.Value() == nil:
tld.patches = append(tld.patches, initPatch{t, s[0], patchField})
p.w(" 0 ")
default:
p.assignmentExpression(f, s[0].AssignmentExpression, t, exprValue, 0)
}
return
}
// 12: The rest of this subclause deals with initializers for objects that have
// aggregate or union type.
k := t.Kind()
// 13: The initializer for a structure or union object that has automatic
// storage duration shall be either an initializer list as described below, or
// a single expression that has compatible structure or union type. In the
// latter case, the initial value of the object, including unnamed members, is
// that of the expression.
if sc == cc.Automatic && len(s) == 1 {
switch k {
case cc.Struct, cc.Union:
if compatibleStructOrUnion(t, s[0].AssignmentExpression.Operand.Type()) {
p.w("%s%s", tidyComment("", s[0]), tag)
p.assignmentExpression(f, s[0].AssignmentExpression, t, exprValue, 0)
return
}
}
}
if k == cc.Array && len(s) == 1 {
et := t.Elem()
switch {
case isCharType(et):
// 14: An array of character type may be initialized by a character string
// literal, optionally enclosed in braces. Successive characters of the
// character string literal (including the terminating null character if there
// is room or if the array is of unknown size) initialize the elements of the
// array.
if x, ok := s[0].AssignmentExpression.Operand.Value().(cc.StringValue); ok {
p.w("%s%s", tidyComment("", s[0]), tag)
str := cc.StringID(x).String()
slen := uintptr(len(str)) + 1
alen := t.Len()
switch {
case alen < slen-1:
p.w("*(*%s)(unsafe.Pointer(%s))", p.typ(s[0], t), p.stringLiteralString(str[:alen]))
case alen < slen:
p.w("*(*%s)(unsafe.Pointer(%s))", p.typ(s[0], t), p.stringLiteralString(str))
default: // alen >= slen
p.w("*(*%s)(unsafe.Pointer(%s))", p.typ(s[0], t), p.stringLiteralString(str+strings.Repeat("\x00", int(alen-slen))))
}
return
}
case p.isWCharType(et):
// 15: An array with element type compatible with wchar_t may be initialized by
// a wide string literal, optionally enclosed in braces. Successive wide
// characters of the wide string literal (including the terminating null wide
// character if there is room or if the array is of unknown size) initialize
// the elements of the array.
if x, ok := s[0].AssignmentExpression.Operand.Value().(cc.WideStringValue); ok {
p.w("%s%s", tidyComment("", s[0]), tag)
str := []rune(cc.StringID(x).String())
slen := uintptr(len(str)) + 1
alen := t.Len()
switch {
case alen < slen-1:
panic(todo("", p.pos(s[0])))
case alen < slen:
p.w("*(*%s)(unsafe.Pointer(%s))", p.typ(s[0], t), p.wideStringLiteral(x, 0))
default: // alen >= slen
p.w("*(*%s)(unsafe.Pointer(%s))", p.typ(s[0], t), p.wideStringLiteral(x, int(alen-slen)))
}
return
}
}
}
// 16: Otherwise, the initializer for an object that has aggregate or union
// type shall be a brace-enclosed list of initializers for the elements or
// named members.
switch k {
case cc.Array:
p.initializerArray(tag, off, f, s, t, sc, tld, lm, tm)
case cc.Struct:
p.initializerStruct(tag, off, f, s, t, sc, tld, lm, tm)
case cc.Union:
p.initializerUnion(tag, off, f, s, t, sc, tld, lm, tm)
default:
panic(todo("%v: internal error: %v alias %v %v", s[0].Position(), t, t.Alias(), len(s)))
}
}
func (p *project) initializerArray(tag string, off uintptr, f *function, s []*cc.Initializer, t cc.Type, sc cc.StorageClass, tld *tld, lm, tm map[*cc.Initializer][]cc.StringID) {
if len(s) == 0 {
p.w("%s%s{}", tag, p.typ(nil, t))
return
}
et := t.Elem()
esz := et.Size()
s0 := s[0]
p.w("%s%s%s{", initComment(s0, lm), tag, p.typ(s0, t))
var a [][]*cc.Initializer
for len(s) != 0 {
s2, parts, _ := p.initializerArrayElement(off, s, esz)
s = s2
a = append(a, parts)
}
mustIndex := uintptr(len(a)) != t.Len()
var parts []*cc.Initializer
for _, parts = range a {
var comma *cc.Token
comma = parts[len(parts)-1].TrailingComma()
elemOff := (parts[0].Offset - off) / esz * esz
tag = ""
if mustIndex {
tag = fmt.Sprintf("%d:", elemOff/esz)
}
p.initializerInner(tag, off+elemOff, f, parts, et, sc, tld, nil, lm, tm)
p.preCommaSep(comma)
p.w(",")
}
p.w("%s}", initComment(parts[len(parts)-1], tm))
}
func initComment(n *cc.Initializer, m map[*cc.Initializer][]cc.StringID) string {
a := m[n]
if len(a) == 0 {
return ""
}
m[n] = a[1:]
return tidyCommentString(a[0].String())
}
func (p *project) initializerArrayElement(off uintptr, s []*cc.Initializer, elemSize uintptr) (r []*cc.Initializer, parts []*cc.Initializer, isZero bool) {
r = s
isZero = true
valueOff := s[0].Offset - off
elemOff := valueOff - valueOff%elemSize
nextOff := elemOff + elemSize
for len(s) != 0 {
if v := s[0]; v.Offset-off < nextOff {
s = s[1:]
parts = append(parts, v)
if !v.AssignmentExpression.Operand.IsZero() {
isZero = false
}
continue
}
break
}
return r[len(parts):], parts, isZero
}
func (p *project) initializerStruct(tag string, off uintptr, f *function, s []*cc.Initializer, t cc.Type, sc cc.StorageClass, tld *tld, lm, tm map[*cc.Initializer][]cc.StringID) {
if len(s) == 0 {
p.w("%s%s{}", tag, p.typ(nil, t))
return
}
if t.HasFlexibleMember() {
p.err(s[0], "flexible array members not supported")
return
}
p.w("%s%s%s{", initComment(s[0], lm), tag, p.typ(s[0], t))
var parts []*cc.Initializer
var isZero bool
var fld cc.Field
for len(s) != 0 {
var comma *cc.Token
s, fld, parts, isZero = p.structInitializerParts(off, s, t)
if isZero {
continue
}
if fld.Type().IsIncomplete() {
panic(todo(""))
}
comma = parts[len(parts)-1].TrailingComma()
tag = fmt.Sprintf("%s:", p.fieldName2(parts[0], fld))
ft := fld.Type()
switch {
case fld.IsBitField():
bft := p.bitFileType(parts[0], fld.BitFieldBlockWidth())
off0 := fld.Offset()
first := true
for _, v := range parts {
if v.AssignmentExpression.Operand.IsZero() {
continue
}
if !first {
p.w("|")
}
first = false
bitFld := v.Field
p.w("%s%s", tidyComment("", v.AssignmentExpression), tag)
tag = ""
p.assignmentExpression(f, v.AssignmentExpression, bft, exprValue, 0)
p.w("&%#x", uint64(1)<<uint64(bitFld.BitFieldWidth())-1)
if o := bitFld.BitFieldOffset() + 8*int((bitFld.Offset()-off0)); o != 0 {
p.w("<<%d", o)
}
}
default:
p.initializerInner(tag, off+fld.Offset(), f, parts, ft, sc, tld, fld, lm, tm)
}
p.preCommaSep(comma)
p.w(",")
}
p.w("%s}", initComment(parts[len(parts)-1], tm))
}
func (p *project) preCommaSep(comma *cc.Token) {
if comma == nil {
return
}
p.w("%s", strings.TrimSpace(comma.Sep.String()))
}
func (p *project) structInitializerParts(off uintptr, s []*cc.Initializer, t cc.Type) (r []*cc.Initializer, fld cc.Field, parts []*cc.Initializer, isZero bool) {
if len(s) == 0 {
return nil, nil, nil, true
}
part := s[0]
isZero = part.AssignmentExpression.Operand.IsZero()
parts = append(parts, part)
s = s[1:]
fld, _, fNext := p.containingStructField(part, off, t)
for len(s) != 0 {
part = s[0]
vOff := part.Offset
if vOff >= fNext {
break
}
isZero = isZero && part.AssignmentExpression.Operand.IsZero()
parts = append(parts, part)
s = s[1:]
}
return s, fld, parts, isZero
}
func (p *project) containingStructField(part *cc.Initializer, off uintptr, t cc.Type) (f cc.Field, fOff, fNext uintptr) {
nf := t.NumField()
vOff := part.Offset
for i := []int{0}; i[0] < nf; i[0]++ {
f = t.FieldByIndex(i)
if f.IsBitField() && f.Name() == 0 { // Anonymous bit fields cannot be initialized.
continue
}
fOff = off + f.Offset()
switch {
case f.IsBitField():
fNext = fOff + uintptr(f.BitFieldBlockWidth())>>3
default:
fNext = fOff + f.Type().Size()
}
if vOff >= fOff && vOff < fNext {
return f, fOff, fNext
}
}
panic(todo("%v: internal error", p.pos(part)))
}
func (p *project) initializerUnion(tag string, off uintptr, f *function, s []*cc.Initializer, t cc.Type, sc cc.StorageClass, tld *tld, lm, tm map[*cc.Initializer][]cc.StringID) {
if len(s) == 0 {
p.w("%s%s{}", tag, p.typ(nil, t))
return
}
if t.HasFlexibleMember() {
p.err(s[0], "flexible array members not supported")
return
}
parts, isZero := p.initializerUnionField(off, s, t)
if len(parts) == 0 || isZero {
p.w("%s%s%s{", initComment(s[0], lm), tag, p.typ(s[0], t))
p.w("%s}", initComment(parts[len(parts)-1], tm))
return
}
p.w("%sfunc() (r %s) {", tag, p.typ(parts[0], t))
for _, part := range parts {
var ft cc.Type
fld := part.Field
if fld != nil && fld.IsBitField() {
}
if ft == nil {
ft = part.Type()
}
if ft.Kind() == cc.Array {
et := ft.Elem()
switch {
case isCharType(et):
switch x := part.AssignmentExpression.Operand.Value().(type) {
case cc.StringValue:
str := cc.StringID(x).String()
slen := uintptr(len(str)) + 1
alen := ft.Len()
switch {
case alen < slen-1:
p.w("copy(((*[%d]byte)(unsafe.Pointer(uintptr(unsafe.Pointer(&r))+%d)))[:], (*[%d]byte)(unsafe.Pointer(%s))[:])\n", alen, part.Offset-off, alen, p.stringLiteralString(str[:alen]))
case alen < slen:
p.w("copy(((*[%d]byte)(unsafe.Pointer(uintptr(unsafe.Pointer(&r))+%d)))[:], (*[%d]byte)(unsafe.Pointer(%s))[:])\n", alen, part.Offset-off, alen, p.stringLiteralString(str))
default: // alen >= slen
p.w("copy(((*[%d]byte)(unsafe.Pointer(uintptr(unsafe.Pointer(&r))+%d)))[:], (*[%d]byte)(unsafe.Pointer(%s))[:])\n", alen, part.Offset-off, alen, p.stringLiteralString(str+strings.Repeat("\x00", int(alen-slen))))
}
continue
default:
panic(todo("%v: %v <- %T", p.pos(part), et, x))
}
case p.isWCharType(et):
panic(todo(""))
}
ft = et
}
switch {
case fld != nil && fld.IsBitField():
bft := p.bitFileType(part, fld.BitFieldBlockWidth())
p.w("*(*%s)(unsafe.Pointer(uintptr(unsafe.Pointer(&r))+%d)) |= ", p.typ(part, bft), part.Offset-off)
p.assignmentExpression(f, part.AssignmentExpression, bft, exprValue, 0)
p.w("&%#x", uint64(1)<<uint64(fld.BitFieldWidth())-1)
if o := fld.BitFieldOffset(); o != 0 {
p.w("<<%d", o)
}
default:
p.w("*(*%s)(unsafe.Pointer(uintptr(unsafe.Pointer(&r))+%d)) = ", p.typ(part, ft), part.Offset-off)
p.assignmentExpression(f, part.AssignmentExpression, ft, exprValue, 0)
}
p.w("\n")
}
p.w("return r\n")
p.w("}()")
}
func (p *project) initializerUnionField(off uintptr, s []*cc.Initializer, t cc.Type) (parts []*cc.Initializer, isZero bool) {
isZero = true
nextOff := off + t.Size()
for len(s) != 0 {
if v := s[0]; v.Offset < nextOff {
s = s[1:]
parts = append(parts, v)
isZero = isZero && v.AssignmentExpression.Operand.IsZero()
continue
}
break
}
return parts, isZero
}
func compatibleStructOrUnion(t1, t2 cc.Type) bool {
switch t1.Kind() {
case cc.Struct:
if t2.Kind() != cc.Struct {
return false
}
case cc.Union:
if t2.Kind() != cc.Union {
return false
}
default:
return false
}
if tag := t1.Tag(); tag != 0 && t2.Tag() != tag {
return false
}
nf := t1.NumField()
if t2.NumField() != nf {
return false
}
for i := []int{0}; i[0] < nf; i[0]++ {
f1 := t1.FieldByIndex(i)
f2 := t2.FieldByIndex(i)
nm := f1.Name()
if f2.Name() != nm {
return false
}
ft1 := f1.Type()
ft2 := f2.Type()
if ft1.Size() != ft2.Size() ||
f1.IsBitField() != f2.IsBitField() ||
f1.BitFieldOffset() != f2.BitFieldOffset() ||
f1.BitFieldWidth() != f2.BitFieldWidth() {
return false
}
if !compatibleType(ft1, ft2) {
return false
}
}
return true
}
func compatibleType(t1, t2 cc.Type) bool {
if t1.Kind() != t2.Kind() {
return false
}
switch t1.Kind() {
case cc.Array:
if t1.Len() != t2.Len() || !compatibleType(t1.Elem(), t2.Elem()) {
return false
}
case cc.Struct, cc.Union:
if !compatibleStructOrUnion(t1, t2) {
return false
}
}
return true
}
func (p *project) bitFileType(n cc.Node, bits int) cc.Type {
switch bits {
case 8:
return p.task.cfg.ABI.Type(cc.UChar)
case 16:
return p.task.cfg.ABI.Type(cc.UShort)
case 32:
return p.task.cfg.ABI.Type(cc.UInt)
case 64:
return p.task.cfg.ABI.Type(cc.ULongLong)
default:
panic(todo("%v: internal error: %v", n.Position(), bits))
}
}
func (p *project) isWCharType(t cc.Type) bool {
if t.IsAliasType() {
if id := t.AliasDeclarator().Name(); id == idWcharT ||
p.task.goos == "windows" && id == idWinWchar {
return true
}
}
return false
}
func isCharType(t cc.Type) bool {
switch t.Kind() {
case cc.Char, cc.SChar, cc.UChar:
return true
}
return false
}
func (p *project) initializerFlatten(n *cc.Initializer, lm, tm map[*cc.Initializer][]cc.StringID) (s []*cc.Initializer) {
switch n.Case {
case cc.InitializerExpr: // AssignmentExpression
return append(s, n)
case cc.InitializerInitList: // '{' InitializerList ',' '}'
first := true
for list := n.InitializerList; list != nil; list = list.InitializerList {
in := list.Initializer
k := in
if in.Case != cc.InitializerExpr {
k = nil
}
if first {
lm[k] = append(lm[k], append(lm[nil], n.Token.Sep)...)
if k != nil {
delete(lm, nil)
}
first = false
}
if list.InitializerList == nil {
tm[k] = append([]cc.StringID{n.Token3.Sep}, append(tm[nil], tm[k]...)...)
tm[k] = append(tm[k], append(tm[nil], n.Token3.Sep)...)
if k != nil {
delete(tm, nil)
}
}
s = append(s, p.initializerFlatten(in, lm, tm)...)
}
return s
default:
panic(todo("%v: internal error: %v", n.Position(), n.Case))
}
}