go reader 源码
golang reader 代码
文件路径：/src/cmd/compile/internal/noder/reader.go
// UNREVIEWED
// 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 noder
import (
"bytes"
"fmt"
"go/constant"
"internal/buildcfg"
"internal/pkgbits"
"strings"
"cmd/compile/internal/base"
"cmd/compile/internal/deadcode"
"cmd/compile/internal/dwarfgen"
"cmd/compile/internal/inline"
"cmd/compile/internal/ir"
"cmd/compile/internal/reflectdata"
"cmd/compile/internal/typecheck"
"cmd/compile/internal/types"
"cmd/internal/obj"
"cmd/internal/src"
)
type pkgReader struct {
pkgbits.PkgDecoder
posBases []*src.PosBase
pkgs []*types.Pkg
typs []*types.Type
// offset for rewriting the given index into the output,
// but bitwise inverted so we can detect if we're missing the entry or not.
newindex []pkgbits.Index
}
func newPkgReader(pr pkgbits.PkgDecoder) *pkgReader {
return &pkgReader{
PkgDecoder: pr,
posBases: make([]*src.PosBase, pr.NumElems(pkgbits.RelocPosBase)),
pkgs: make([]*types.Pkg, pr.NumElems(pkgbits.RelocPkg)),
typs: make([]*types.Type, pr.NumElems(pkgbits.RelocType)),
newindex: make([]pkgbits.Index, pr.TotalElems()),
}
}
type pkgReaderIndex struct {
pr *pkgReader
idx pkgbits.Index
dict *readerDict
}
func (pri pkgReaderIndex) asReader(k pkgbits.RelocKind, marker pkgbits.SyncMarker) *reader {
r := pri.pr.newReader(k, pri.idx, marker)
r.dict = pri.dict
return r
}
func (pr *pkgReader) newReader(k pkgbits.RelocKind, idx pkgbits.Index, marker pkgbits.SyncMarker) *reader {
return &reader{
Decoder: pr.NewDecoder(k, idx, marker),
p: pr,
}
}
type reader struct {
pkgbits.Decoder
p *pkgReader
dict *readerDict
// TODO(mdempsky): The state below is all specific to reading
// function bodies. It probably makes sense to split it out
// separately so that it doesn't take up space in every reader
// instance.
curfn *ir.Func
locals []*ir.Name
closureVars []*ir.Name
funarghack bool
// scopeVars is a stack tracking the number of variables declared in
// the current function at the moment each open scope was opened.
scopeVars []int
marker dwarfgen.ScopeMarker
lastCloseScopePos src.XPos
// === details for handling inline body expansion ===
// If we're reading in a function body because of inlining, this is
// the call that we're inlining for.
inlCaller *ir.Func
inlCall *ir.CallExpr
inlFunc *ir.Func
inlTreeIndex int
inlPosBases map[*src.PosBase]*src.PosBase
delayResults bool
// Label to return to.
retlabel *types.Sym
inlvars, retvars ir.Nodes
}
type readerDict struct {
// targs holds the implicit and explicit type arguments in use for
// reading the current object. For example:
//
// func F[T any]() {
// type X[U any] struct { t T; u U }
// var _ X[string]
// }
//
// var _ = F[int]
//
// While instantiating F[int], we need to in turn instantiate
// X[string]. [int] and [string] are explicit type arguments for F
// and X, respectively; but [int] is also the implicit type
// arguments for X.
//
// (As an analogy to function literals, explicits are the function
// literal's formal parameters, while implicits are variables
// captured by the function literal.)
targs []*types.Type
// implicits counts how many of types within targs are implicit type
// arguments; the rest are explicit.
implicits int
derived []derivedInfo // reloc index of the derived type's descriptor
derivedTypes []*types.Type // slice of previously computed derived types
funcs []objInfo
funcsObj []ir.Node
itabs []itabInfo2
}
type itabInfo2 struct {
typ *types.Type
lsym *obj.LSym
}
func setType(n ir.Node, typ *types.Type) {
n.SetType(typ)
n.SetTypecheck(1)
}
func setValue(name *ir.Name, val constant.Value) {
name.SetVal(val)
name.Defn = nil
}
// @@@ Positions
func (r *reader) pos() src.XPos {
return base.Ctxt.PosTable.XPos(r.pos0())
}
func (r *reader) pos0() src.Pos {
r.Sync(pkgbits.SyncPos)
if !r.Bool() {
return src.NoPos
}
posBase := r.posBase()
line := r.Uint()
col := r.Uint()
return src.MakePos(posBase, line, col)
}
func (r *reader) posBase() *src.PosBase {
return r.inlPosBase(r.p.posBaseIdx(r.Reloc(pkgbits.RelocPosBase)))
}
func (pr *pkgReader) posBaseIdx(idx pkgbits.Index) *src.PosBase {
if b := pr.posBases[idx]; b != nil {
return b
}
r := pr.newReader(pkgbits.RelocPosBase, idx, pkgbits.SyncPosBase)
var b *src.PosBase
absFilename := r.String()
filename := absFilename
// For build artifact stability, the export data format only
// contains the "absolute" filename as returned by objabi.AbsFile.
// However, some tests (e.g., test/run.go's asmcheck tests) expect
// to see the full, original filename printed out. Re-expanding
// "$GOROOT" to buildcfg.GOROOT is a close-enough approximation to
// satisfy this.
//
// TODO(mdempsky): De-duplicate this logic with similar logic in
// cmd/link/internal/ld's expandGoroot. However, this will probably
// require being more consistent about when we use native vs UNIX
// file paths.
const dollarGOROOT = "$GOROOT"
if buildcfg.GOROOT != "" && strings.HasPrefix(filename, dollarGOROOT) {
filename = buildcfg.GOROOT + filename[len(dollarGOROOT):]
}
if r.Bool() {
b = src.NewFileBase(filename, absFilename)
} else {
pos := r.pos0()
line := r.Uint()
col := r.Uint()
b = src.NewLinePragmaBase(pos, filename, absFilename, line, col)
}
pr.posBases[idx] = b
return b
}
func (r *reader) inlPosBase(oldBase *src.PosBase) *src.PosBase {
if r.inlCall == nil {
return oldBase
}
if newBase, ok := r.inlPosBases[oldBase]; ok {
return newBase
}
newBase := src.NewInliningBase(oldBase, r.inlTreeIndex)
r.inlPosBases[oldBase] = newBase
return newBase
}
func (r *reader) updatePos(xpos src.XPos) src.XPos {
pos := base.Ctxt.PosTable.Pos(xpos)
pos.SetBase(r.inlPosBase(pos.Base()))
return base.Ctxt.PosTable.XPos(pos)
}
func (r *reader) origPos(xpos src.XPos) src.XPos {
if r.inlCall == nil {
return xpos
}
pos := base.Ctxt.PosTable.Pos(xpos)
for old, new := range r.inlPosBases {
if pos.Base() == new {
pos.SetBase(old)
return base.Ctxt.PosTable.XPos(pos)
}
}
base.FatalfAt(xpos, "pos base missing from inlPosBases")
panic("unreachable")
}
// @@@ Packages
func (r *reader) pkg() *types.Pkg {
r.Sync(pkgbits.SyncPkg)
return r.p.pkgIdx(r.Reloc(pkgbits.RelocPkg))
}
func (pr *pkgReader) pkgIdx(idx pkgbits.Index) *types.Pkg {
if pkg := pr.pkgs[idx]; pkg != nil {
return pkg
}
pkg := pr.newReader(pkgbits.RelocPkg, idx, pkgbits.SyncPkgDef).doPkg()
pr.pkgs[idx] = pkg
return pkg
}
func (r *reader) doPkg() *types.Pkg {
path := r.String()
switch path {
case "":
path = r.p.PkgPath()
case "builtin":
return types.BuiltinPkg
case "unsafe":
return types.UnsafePkg
}
name := r.String()
height := r.Len()
pkg := types.NewPkg(path, "")
if pkg.Name == "" {
pkg.Name = name
} else {
base.Assertf(pkg.Name == name, "package %q has name %q, but want %q", pkg.Path, pkg.Name, name)
}
if pkg.Height == 0 {
pkg.Height = height
} else {
base.Assertf(pkg.Height == height, "package %q has height %v, but want %v", pkg.Path, pkg.Height, height)
}
return pkg
}
// @@@ Types
func (r *reader) typ() *types.Type {
return r.typWrapped(true)
}
// typWrapped is like typ, but allows suppressing generation of
// unnecessary wrappers as a compile-time optimization.
func (r *reader) typWrapped(wrapped bool) *types.Type {
return r.p.typIdx(r.typInfo(), r.dict, wrapped)
}
func (r *reader) typInfo() typeInfo {
r.Sync(pkgbits.SyncType)
if r.Bool() {
return typeInfo{idx: pkgbits.Index(r.Len()), derived: true}
}
return typeInfo{idx: r.Reloc(pkgbits.RelocType), derived: false}
}
func (pr *pkgReader) typIdx(info typeInfo, dict *readerDict, wrapped bool) *types.Type {
idx := info.idx
var where **types.Type
if info.derived {
where = &dict.derivedTypes[idx]
idx = dict.derived[idx].idx
} else {
where = &pr.typs[idx]
}
if typ := *where; typ != nil {
return typ
}
r := pr.newReader(pkgbits.RelocType, idx, pkgbits.SyncTypeIdx)
r.dict = dict
typ := r.doTyp()
assert(typ != nil)
// For recursive type declarations involving interfaces and aliases,
// above r.doTyp() call may have already set pr.typs[idx], so just
// double check and return the type.
//
// Example:
//
// type F = func(I)
//
// type I interface {
// m(F)
// }
//
// The writer writes data types in following index order:
//
// 0: func(I)
// 1: I
// 2: interface{m(func(I))}
//
// The reader resolves it in following index order:
//
// 0 -> 1 -> 2 -> 0 -> 1
//
// and can divide in logically 2 steps:
//
// - 0 -> 1 : first time the reader reach type I,
// it creates new named type with symbol I.
//
// - 2 -> 0 -> 1: the reader ends up reaching symbol I again,
// now the symbol I was setup in above step, so
// the reader just return the named type.
//
// Now, the functions called return, the pr.typs looks like below:
//
// - 0 -> 1 -> 2 -> 0 : [<T> I <T>]
// - 0 -> 1 -> 2 : [func(I) I <T>]
// - 0 -> 1 : [func(I) I interface { "".m(func("".I)) }]
//
// The idx 1, corresponding with type I was resolved successfully
// after r.doTyp() call.
if prev := *where; prev != nil {
return prev
}
if wrapped {
// Only cache if we're adding wrappers, so that other callers that
// find a cached type know it was wrapped.
*where = typ
r.needWrapper(typ)
}
if !typ.IsUntyped() {
types.CheckSize(typ)
}
return typ
}
func (r *reader) doTyp() *types.Type {
switch tag := pkgbits.CodeType(r.Code(pkgbits.SyncType)); tag {
default:
panic(fmt.Sprintf("unexpected type: %v", tag))
case pkgbits.TypeBasic:
return *basics[r.Len()]
case pkgbits.TypeNamed:
obj := r.obj()
assert(obj.Op() == ir.OTYPE)
return obj.Type()
case pkgbits.TypeTypeParam:
return r.dict.targs[r.Len()]
case pkgbits.TypeArray:
len := int64(r.Uint64())
return types.NewArray(r.typ(), len)
case pkgbits.TypeChan:
dir := dirs[r.Len()]
return types.NewChan(r.typ(), dir)
case pkgbits.TypeMap:
return types.NewMap(r.typ(), r.typ())
case pkgbits.TypePointer:
return types.NewPtr(r.typ())
case pkgbits.TypeSignature:
return r.signature(types.LocalPkg, nil)
case pkgbits.TypeSlice:
return types.NewSlice(r.typ())
case pkgbits.TypeStruct:
return r.structType()
case pkgbits.TypeInterface:
return r.interfaceType()
case pkgbits.TypeUnion:
return r.unionType()
}
}
func (r *reader) unionType() *types.Type {
terms := make([]*types.Type, r.Len())
tildes := make([]bool, len(terms))
for i := range terms {
tildes[i] = r.Bool()
terms[i] = r.typ()
}
return types.NewUnion(terms, tildes)
}
func (r *reader) interfaceType() *types.Type {
tpkg := types.LocalPkg // TODO(mdempsky): Remove after iexport is gone.
nmethods, nembeddeds := r.Len(), r.Len()
implicit := nmethods == 0 && nembeddeds == 1 && r.Bool()
assert(!implicit) // implicit interfaces only appear in constraints
fields := make([]*types.Field, nmethods+nembeddeds)
methods, embeddeds := fields[:nmethods], fields[nmethods:]
for i := range methods {
pos := r.pos()
pkg, sym := r.selector()
tpkg = pkg
mtyp := r.signature(pkg, types.FakeRecv())
methods[i] = types.NewField(pos, sym, mtyp)
}
for i := range embeddeds {
embeddeds[i] = types.NewField(src.NoXPos, nil, r.typ())
}
if len(fields) == 0 {
return types.Types[types.TINTER] // empty interface
}
return types.NewInterface(tpkg, fields, false)
}
func (r *reader) structType() *types.Type {
tpkg := types.LocalPkg // TODO(mdempsky): Remove after iexport is gone.
fields := make([]*types.Field, r.Len())
for i := range fields {
pos := r.pos()
pkg, sym := r.selector()
tpkg = pkg
ftyp := r.typ()
tag := r.String()
embedded := r.Bool()
f := types.NewField(pos, sym, ftyp)
f.Note = tag
if embedded {
f.Embedded = 1
}
fields[i] = f
}
return types.NewStruct(tpkg, fields)
}
func (r *reader) signature(tpkg *types.Pkg, recv *types.Field) *types.Type {
r.Sync(pkgbits.SyncSignature)
params := r.params(&tpkg)
results := r.params(&tpkg)
if r.Bool() { // variadic
params[len(params)-1].SetIsDDD(true)
}
return types.NewSignature(tpkg, recv, nil, params, results)
}
func (r *reader) params(tpkg **types.Pkg) []*types.Field {
r.Sync(pkgbits.SyncParams)
fields := make([]*types.Field, r.Len())
for i := range fields {
*tpkg, fields[i] = r.param()
}
return fields
}
func (r *reader) param() (*types.Pkg, *types.Field) {
r.Sync(pkgbits.SyncParam)
pos := r.pos()
pkg, sym := r.localIdent()
typ := r.typ()
return pkg, types.NewField(pos, sym, typ)
}
// @@@ Objects
var objReader = map[*types.Sym]pkgReaderIndex{}
func (r *reader) obj() ir.Node {
r.Sync(pkgbits.SyncObject)
if r.Bool() {
idx := r.Len()
obj := r.dict.funcsObj[idx]
if obj == nil {
fn := r.dict.funcs[idx]
targs := make([]*types.Type, len(fn.explicits))
for i, targ := range fn.explicits {
targs[i] = r.p.typIdx(targ, r.dict, true)
}
obj = r.p.objIdx(fn.idx, nil, targs)
assert(r.dict.funcsObj[idx] == nil)
r.dict.funcsObj[idx] = obj
}
return obj
}
idx := r.Reloc(pkgbits.RelocObj)
explicits := make([]*types.Type, r.Len())
for i := range explicits {
explicits[i] = r.typ()
}
var implicits []*types.Type
if r.dict != nil {
implicits = r.dict.targs
}
return r.p.objIdx(idx, implicits, explicits)
}
func (pr *pkgReader) objIdx(idx pkgbits.Index, implicits, explicits []*types.Type) ir.Node {
rname := pr.newReader(pkgbits.RelocName, idx, pkgbits.SyncObject1)
_, sym := rname.qualifiedIdent()
tag := pkgbits.CodeObj(rname.Code(pkgbits.SyncCodeObj))
if tag == pkgbits.ObjStub {
assert(!sym.IsBlank())
switch sym.Pkg {
case types.BuiltinPkg, types.UnsafePkg:
return sym.Def.(ir.Node)
}
if pri, ok := objReader[sym]; ok {
return pri.pr.objIdx(pri.idx, nil, explicits)
}
base.Fatalf("unresolved stub: %v", sym)
}
dict := pr.objDictIdx(sym, idx, implicits, explicits)
r := pr.newReader(pkgbits.RelocObj, idx, pkgbits.SyncObject1)
rext := pr.newReader(pkgbits.RelocObjExt, idx, pkgbits.SyncObject1)
r.dict = dict
rext.dict = dict
sym = r.mangle(sym)
if !sym.IsBlank() && sym.Def != nil {
return sym.Def.(*ir.Name)
}
do := func(op ir.Op, hasTParams bool) *ir.Name {
pos := r.pos()
if hasTParams {
r.typeParamNames()
}
name := ir.NewDeclNameAt(pos, op, sym)
name.Class = ir.PEXTERN // may be overridden later
if !sym.IsBlank() {
if sym.Def != nil {
base.FatalfAt(name.Pos(), "already have a definition for %v", name)
}
assert(sym.Def == nil)
sym.Def = name
}
return name
}
switch tag {
default:
panic("unexpected object")
case pkgbits.ObjAlias:
name := do(ir.OTYPE, false)
setType(name, r.typ())
name.SetAlias(true)
return name
case pkgbits.ObjConst:
name := do(ir.OLITERAL, false)
typ := r.typ()
val := FixValue(typ, r.Value())
setType(name, typ)
setValue(name, val)
return name
case pkgbits.ObjFunc:
if sym.Name == "init" {
sym = Renameinit()
}
name := do(ir.ONAME, true)
setType(name, r.signature(sym.Pkg, nil))
name.Func = ir.NewFunc(r.pos())
name.Func.Nname = name
if r.hasTypeParams() {
name.Func.SetDupok(true)
}
rext.funcExt(name)
return name
case pkgbits.ObjType:
name := do(ir.OTYPE, true)
typ := types.NewNamed(name)
setType(name, typ)
// Important: We need to do this before SetUnderlying.
rext.typeExt(name)
// We need to defer CheckSize until we've called SetUnderlying to
// handle recursive types.
types.DeferCheckSize()
typ.SetUnderlying(r.typWrapped(false))
types.ResumeCheckSize()
methods := make([]*types.Field, r.Len())
for i := range methods {
methods[i] = r.method(rext)
}
if len(methods) != 0 {
typ.Methods().Set(methods)
}
r.needWrapper(typ)
return name
case pkgbits.ObjVar:
name := do(ir.ONAME, false)
setType(name, r.typ())
rext.varExt(name)
return name
}
}
func (r *reader) mangle(sym *types.Sym) *types.Sym {
if !r.hasTypeParams() {
return sym
}
var buf bytes.Buffer
buf.WriteString(sym.Name)
buf.WriteByte('[')
for i, targ := range r.dict.targs {
if i > 0 {
if i == r.dict.implicits {
buf.WriteByte(';')
} else {
buf.WriteByte(',')
}
}
buf.WriteString(targ.LinkString())
}
buf.WriteByte(']')
return sym.Pkg.Lookup(buf.String())
}
func (pr *pkgReader) objDictIdx(sym *types.Sym, idx pkgbits.Index, implicits, explicits []*types.Type) *readerDict {
r := pr.newReader(pkgbits.RelocObjDict, idx, pkgbits.SyncObject1)
var dict readerDict
nimplicits := r.Len()
nexplicits := r.Len()
if nimplicits > len(implicits) || nexplicits != len(explicits) {
base.Fatalf("%v has %v+%v params, but instantiated with %v+%v args", sym, nimplicits, nexplicits, len(implicits), len(explicits))
}
dict.targs = append(implicits[:nimplicits:nimplicits], explicits...)
dict.implicits = nimplicits
// For stenciling, we can just skip over the type parameters.
for range dict.targs[dict.implicits:] {
// Skip past bounds without actually evaluating them.
r.Sync(pkgbits.SyncType)
if r.Bool() {
r.Len()
} else {
r.Reloc(pkgbits.RelocType)
}
}
dict.derived = make([]derivedInfo, r.Len())
dict.derivedTypes = make([]*types.Type, len(dict.derived))
for i := range dict.derived {
dict.derived[i] = derivedInfo{r.Reloc(pkgbits.RelocType), r.Bool()}
}
dict.funcs = make([]objInfo, r.Len())
dict.funcsObj = make([]ir.Node, len(dict.funcs))
for i := range dict.funcs {
objIdx := r.Reloc(pkgbits.RelocObj)
targs := make([]typeInfo, r.Len())
for j := range targs {
targs[j] = r.typInfo()
}
dict.funcs[i] = objInfo{idx: objIdx, explicits: targs}
}
dict.itabs = make([]itabInfo2, r.Len())
for i := range dict.itabs {
typ := pr.typIdx(typeInfo{idx: pkgbits.Index(r.Len()), derived: true}, &dict, true)
ifaceInfo := r.typInfo()
var lsym *obj.LSym
if typ.IsInterface() {
lsym = reflectdata.TypeLinksym(typ)
} else {
iface := pr.typIdx(ifaceInfo, &dict, true)
lsym = reflectdata.ITabLsym(typ, iface)
}
dict.itabs[i] = itabInfo2{typ: typ, lsym: lsym}
}
return &dict
}
func (r *reader) typeParamNames() {
r.Sync(pkgbits.SyncTypeParamNames)
for range r.dict.targs[r.dict.implicits:] {
r.pos()
r.localIdent()
}
}
func (r *reader) method(rext *reader) *types.Field {
r.Sync(pkgbits.SyncMethod)
pos := r.pos()
pkg, sym := r.selector()
r.typeParamNames()
_, recv := r.param()
typ := r.signature(pkg, recv)
fnsym := sym
fnsym = ir.MethodSym(recv.Type, fnsym)
name := ir.NewNameAt(pos, fnsym)
setType(name, typ)
name.Func = ir.NewFunc(r.pos())
name.Func.Nname = name
if r.hasTypeParams() {
name.Func.SetDupok(true)
}
rext.funcExt(name)
meth := types.NewField(name.Func.Pos(), sym, typ)
meth.Nname = name
meth.SetNointerface(name.Func.Pragma&ir.Nointerface != 0)
return meth
}
func (r *reader) qualifiedIdent() (pkg *types.Pkg, sym *types.Sym) {
r.Sync(pkgbits.SyncSym)
pkg = r.pkg()
if name := r.String(); name != "" {
sym = pkg.Lookup(name)
}
return
}
func (r *reader) localIdent() (pkg *types.Pkg, sym *types.Sym) {
r.Sync(pkgbits.SyncLocalIdent)
pkg = r.pkg()
if name := r.String(); name != "" {
sym = pkg.Lookup(name)
}
return
}
func (r *reader) selector() (origPkg *types.Pkg, sym *types.Sym) {
r.Sync(pkgbits.SyncSelector)
origPkg = r.pkg()
name := r.String()
pkg := origPkg
if types.IsExported(name) {
pkg = types.LocalPkg
}
sym = pkg.Lookup(name)
return
}
func (r *reader) hasTypeParams() bool {
return r.dict.hasTypeParams()
}
func (dict *readerDict) hasTypeParams() bool {
return dict != nil && len(dict.targs) != 0
}
// @@@ Compiler extensions
func (r *reader) funcExt(name *ir.Name) {
r.Sync(pkgbits.SyncFuncExt)
name.Class = 0 // so MarkFunc doesn't complain
ir.MarkFunc(name)
fn := name.Func
// XXX: Workaround because linker doesn't know how to copy Pos.
if !fn.Pos().IsKnown() {
fn.SetPos(name.Pos())
}
// Normally, we only compile local functions, which saves redundant compilation work.
// n.Defn is not nil for local functions, and is nil for imported function. But for
// generic functions, we might have an instantiation that no other package has seen before.
// So we need to be conservative and compile it again.
//
// That's why name.Defn is set here, so ir.VisitFuncsBottomUp can analyze function.
// TODO(mdempsky,cuonglm): find a cleaner way to handle this.
if name.Sym().Pkg == types.LocalPkg || r.hasTypeParams() {
name.Defn = fn
}
fn.Pragma = r.pragmaFlag()
r.linkname(name)
typecheck.Func(fn)
if r.Bool() {
fn.ABI = obj.ABI(r.Uint64())
// Escape analysis.
for _, fs := range &types.RecvsParams {
for _, f := range fs(name.Type()).FieldSlice() {
f.Note = r.String()
}
}
if r.Bool() {
fn.Inl = &ir.Inline{
Cost: int32(r.Len()),
CanDelayResults: r.Bool(),
}
r.addBody(name.Func)
}
} else {
r.addBody(name.Func)
}
r.Sync(pkgbits.SyncEOF)
}
func (r *reader) typeExt(name *ir.Name) {
r.Sync(pkgbits.SyncTypeExt)
typ := name.Type()
if r.hasTypeParams() {
// Set "RParams" (really type arguments here, not parameters) so
// this type is treated as "fully instantiated". This ensures the
// type descriptor is written out as DUPOK and method wrappers are
// generated even for imported types.
var targs []*types.Type
targs = append(targs, r.dict.targs...)
typ.SetRParams(targs)
}
name.SetPragma(r.pragmaFlag())
if name.Pragma()&ir.NotInHeap != 0 {
typ.SetNotInHeap(true)
}
typecheck.SetBaseTypeIndex(typ, r.Int64(), r.Int64())
}
func (r *reader) varExt(name *ir.Name) {
r.Sync(pkgbits.SyncVarExt)
r.linkname(name)
}
func (r *reader) linkname(name *ir.Name) {
assert(name.Op() == ir.ONAME)
r.Sync(pkgbits.SyncLinkname)
if idx := r.Int64(); idx >= 0 {
lsym := name.Linksym()
lsym.SymIdx = int32(idx)
lsym.Set(obj.AttrIndexed, true)
} else {
name.Sym().Linkname = r.String()
}
}
func (r *reader) pragmaFlag() ir.PragmaFlag {
r.Sync(pkgbits.SyncPragma)
return ir.PragmaFlag(r.Int())
}
// @@@ Function bodies
// bodyReader tracks where the serialized IR for a function's body can
// be found.
var bodyReader = map[*ir.Func]pkgReaderIndex{}
// todoBodies holds the list of function bodies that still need to be
// constructed.
var todoBodies []*ir.Func
func (r *reader) addBody(fn *ir.Func) {
pri := pkgReaderIndex{r.p, r.Reloc(pkgbits.RelocBody), r.dict}
bodyReader[fn] = pri
if fn.Nname.Defn == nil {
// Don't read in function body for imported functions.
// See comment in funcExt.
return
}
if r.curfn == nil {
todoBodies = append(todoBodies, fn)
return
}
pri.funcBody(fn)
}
func (pri pkgReaderIndex) funcBody(fn *ir.Func) {
r := pri.asReader(pkgbits.RelocBody, pkgbits.SyncFuncBody)
r.funcBody(fn)
}
func (r *reader) funcBody(fn *ir.Func) {
r.curfn = fn
r.closureVars = fn.ClosureVars
ir.WithFunc(fn, func() {
r.funcargs(fn)
if !r.Bool() {
return
}
body := r.stmts()
if body == nil {
body = []ir.Node{typecheck.Stmt(ir.NewBlockStmt(src.NoXPos, nil))}
}
fn.Body = body
fn.Endlineno = r.pos()
})
r.marker.WriteTo(fn)
}
func (r *reader) funcargs(fn *ir.Func) {
sig := fn.Nname.Type()
if recv := sig.Recv(); recv != nil {
r.funcarg(recv, recv.Sym, ir.PPARAM)
}
for _, param := range sig.Params().FieldSlice() {
r.funcarg(param, param.Sym, ir.PPARAM)
}
for i, param := range sig.Results().FieldSlice() {
sym := types.OrigSym(param.Sym)
if sym == nil || sym.IsBlank() {
prefix := "~r"
if r.inlCall != nil {
prefix = "~R"
} else if sym != nil {
prefix = "~b"
}
sym = typecheck.LookupNum(prefix, i)
}
r.funcarg(param, sym, ir.PPARAMOUT)
}
}
func (r *reader) funcarg(param *types.Field, sym *types.Sym, ctxt ir.Class) {
if sym == nil {
assert(ctxt == ir.PPARAM)
if r.inlCall != nil {
r.inlvars.Append(ir.BlankNode)
}
return
}
name := ir.NewNameAt(r.updatePos(param.Pos), sym)
setType(name, param.Type)
r.addLocal(name, ctxt)
if r.inlCall == nil {
if !r.funarghack {
param.Sym = sym
param.Nname = name
}
} else {
if ctxt == ir.PPARAMOUT {
r.retvars.Append(name)
} else {
r.inlvars.Append(name)
}
}
}
func (r *reader) addLocal(name *ir.Name, ctxt ir.Class) {
assert(ctxt == ir.PAUTO || ctxt == ir.PPARAM || ctxt == ir.PPARAMOUT)
r.Sync(pkgbits.SyncAddLocal)
if pkgbits.EnableSync {
want := r.Int()
if have := len(r.locals); have != want {
base.FatalfAt(name.Pos(), "locals table has desynced")
}
}
name.SetUsed(true)
r.locals = append(r.locals, name)
// TODO(mdempsky): Move earlier.
if ir.IsBlank(name) {
return
}
if r.inlCall != nil {
if ctxt == ir.PAUTO {
name.SetInlLocal(true)
} else {
name.SetInlFormal(true)
ctxt = ir.PAUTO
}
// TODO(mdempsky): Rethink this hack.
if strings.HasPrefix(name.Sym().Name, "~") || base.Flag.GenDwarfInl == 0 {
name.SetPos(r.inlCall.Pos())
name.SetInlFormal(false)
name.SetInlLocal(false)
}
}
name.Class = ctxt
name.Curfn = r.curfn
r.curfn.Dcl = append(r.curfn.Dcl, name)
if ctxt == ir.PAUTO {
name.SetFrameOffset(0)
}
}
func (r *reader) useLocal() *ir.Name {
r.Sync(pkgbits.SyncUseObjLocal)
if r.Bool() {
return r.locals[r.Len()]
}
return r.closureVars[r.Len()]
}
func (r *reader) openScope() {
r.Sync(pkgbits.SyncOpenScope)
pos := r.pos()
if base.Flag.Dwarf {
r.scopeVars = append(r.scopeVars, len(r.curfn.Dcl))
r.marker.Push(pos)
}
}
func (r *reader) closeScope() {
r.Sync(pkgbits.SyncCloseScope)
r.lastCloseScopePos = r.pos()
r.closeAnotherScope()
}
// closeAnotherScope is like closeScope, but it reuses the same mark
// position as the last closeScope call. This is useful for "for" and
// "if" statements, as their implicit blocks always end at the same
// position as an explicit block.
func (r *reader) closeAnotherScope() {
r.Sync(pkgbits.SyncCloseAnotherScope)
if base.Flag.Dwarf {
scopeVars := r.scopeVars[len(r.scopeVars)-1]
r.scopeVars = r.scopeVars[:len(r.scopeVars)-1]
// Quirkish: noder decides which scopes to keep before
// typechecking, whereas incremental typechecking during IR
// construction can result in new autotemps being allocated. To
// produce identical output, we ignore autotemps here for the
// purpose of deciding whether to retract the scope.
//
// This is important for net/http/fcgi, because it contains:
//
// var body io.ReadCloser
// if len(content) > 0 {
// body, req.pw = io.Pipe()
// } else { … }
//
// Notably, io.Pipe is inlinable, and inlining it introduces a ~R0
// variable at the call site.
//
// Noder does not preserve the scope where the io.Pipe() call
// resides, because it doesn't contain any declared variables in
// source. So the ~R0 variable ends up being assigned to the
// enclosing scope instead.
//
// However, typechecking this assignment also introduces
// autotemps, because io.Pipe's results need conversion before
// they can be assigned to their respective destination variables.
//
// TODO(mdempsky): We should probably just keep all scopes, and
// let dwarfgen take care of pruning them instead.
retract := true
for _, n := range r.curfn.Dcl[scopeVars:] {
if !n.AutoTemp() {
retract = false
break
}
}
if retract {
// no variables were declared in this scope, so we can retract it.
r.marker.Unpush()
} else {
r.marker.Pop(r.lastCloseScopePos)
}
}
}
// @@@ Statements
func (r *reader) stmt() ir.Node {
switch stmts := r.stmts(); len(stmts) {
case 0:
return nil
case 1:
return stmts[0]
default:
return ir.NewBlockStmt(stmts[0].Pos(), stmts)
}
}
func (r *reader) stmts() []ir.Node {
assert(ir.CurFunc == r.curfn)
var res ir.Nodes
r.Sync(pkgbits.SyncStmts)
for {
tag := codeStmt(r.Code(pkgbits.SyncStmt1))
if tag == stmtEnd {
r.Sync(pkgbits.SyncStmtsEnd)
return res
}
if n := r.stmt1(tag, &res); n != nil {
res.Append(typecheck.Stmt(n))
}
}
}
func (r *reader) stmt1(tag codeStmt, out *ir.Nodes) ir.Node {
var label *types.Sym
if n := len(*out); n > 0 {
if ls, ok := (*out)[n-1].(*ir.LabelStmt); ok {
label = ls.Label
}
}
switch tag {
default:
panic("unexpected statement")
case stmtAssign:
pos := r.pos()
// TODO(mdempsky): After quirks mode is gone, swap these
// statements so we visit LHS before RHS again.
rhs := r.exprList()
names, lhs := r.assignList()
if len(rhs) == 0 {
for _, name := range names {
as := ir.NewAssignStmt(pos, name, nil)
as.PtrInit().Append(ir.NewDecl(pos, ir.ODCL, name))
out.Append(typecheck.Stmt(as))
}
return nil
}
if len(lhs) == 1 && len(rhs) == 1 {
n := ir.NewAssignStmt(pos, lhs[0], rhs[0])
n.Def = r.initDefn(n, names)
return n
}
n := ir.NewAssignListStmt(pos, ir.OAS2, lhs, rhs)
n.Def = r.initDefn(n, names)
return n
case stmtAssignOp:
op := r.op()
lhs := r.expr()
pos := r.pos()
rhs := r.expr()
return ir.NewAssignOpStmt(pos, op, lhs, rhs)
case stmtIncDec:
op := r.op()
lhs := r.expr()
pos := r.pos()
n := ir.NewAssignOpStmt(pos, op, lhs, ir.NewBasicLit(pos, one))
n.IncDec = true
return n
case stmtBlock:
out.Append(r.blockStmt()...)
return nil
case stmtBranch:
pos := r.pos()
op := r.op()
sym := r.optLabel()
return ir.NewBranchStmt(pos, op, sym)
case stmtCall:
pos := r.pos()
op := r.op()
call := r.expr()
return ir.NewGoDeferStmt(pos, op, call)
case stmtExpr:
return r.expr()
case stmtFor:
return r.forStmt(label)
case stmtIf:
return r.ifStmt()
case stmtLabel:
pos := r.pos()
sym := r.label()
return ir.NewLabelStmt(pos, sym)
case stmtReturn:
pos := r.pos()
results := r.exprList()
return ir.NewReturnStmt(pos, results)
case stmtSelect:
return r.selectStmt(label)
case stmtSend:
pos := r.pos()
ch := r.expr()
value := r.expr()
return ir.NewSendStmt(pos, ch, value)
case stmtSwitch:
return r.switchStmt(label)
}
}
func (r *reader) assignList() ([]*ir.Name, []ir.Node) {
lhs := make([]ir.Node, r.Len())
var names []*ir.Name
for i := range lhs {
if r.Bool() {
pos := r.pos()
_, sym := r.localIdent()
typ := r.typ()
name := ir.NewNameAt(pos, sym)
lhs[i] = name
names = append(names, name)
setType(name, typ)
r.addLocal(name, ir.PAUTO)
continue
}
lhs[i] = r.expr()
}
return names, lhs
}
func (r *reader) blockStmt() []ir.Node {
r.Sync(pkgbits.SyncBlockStmt)
r.openScope()
stmts := r.stmts()
r.closeScope()
return stmts
}
func (r *reader) forStmt(label *types.Sym) ir.Node {
r.Sync(pkgbits.SyncForStmt)
r.openScope()
if r.Bool() {
pos := r.pos()
// TODO(mdempsky): After quirks mode is gone, swap these
// statements so we read LHS before X again.
x := r.expr()
names, lhs := r.assignList()
body := r.blockStmt()
r.closeAnotherScope()
rang := ir.NewRangeStmt(pos, nil, nil, x, body)
if len(lhs) >= 1 {
rang.Key = lhs[0]
if len(lhs) >= 2 {
rang.Value = lhs[1]
}
}
rang.Def = r.initDefn(rang, names)
rang.Label = label
return rang
}
pos := r.pos()
init := r.stmt()
cond := r.expr()
post := r.stmt()
body := r.blockStmt()
r.closeAnotherScope()
stmt := ir.NewForStmt(pos, init, cond, post, body)
stmt.Label = label
return stmt
}
func (r *reader) ifStmt() ir.Node {
r.Sync(pkgbits.SyncIfStmt)
r.openScope()
pos := r.pos()
init := r.stmts()
cond := r.expr()
then := r.blockStmt()
els := r.stmts()
n := ir.NewIfStmt(pos, cond, then, els)
n.SetInit(init)
r.closeAnotherScope()
return n
}
func (r *reader) selectStmt(label *types.Sym) ir.Node {
r.Sync(pkgbits.SyncSelectStmt)
pos := r.pos()
clauses := make([]*ir.CommClause, r.Len())
for i := range clauses {
if i > 0 {
r.closeScope()
}
r.openScope()
pos := r.pos()
comm := r.stmt()
body := r.stmts()
clauses[i] = ir.NewCommStmt(pos, comm, body)
}
if len(clauses) > 0 {
r.closeScope()
}
n := ir.NewSelectStmt(pos, clauses)
n.Label = label
return n
}
func (r *reader) switchStmt(label *types.Sym) ir.Node {
r.Sync(pkgbits.SyncSwitchStmt)
r.openScope()
pos := r.pos()
init := r.stmt()
var tag ir.Node
var ident *ir.Ident
var iface *types.Type
if r.Bool() {
pos := r.pos()
if r.Bool() {
pos := r.pos()
sym := typecheck.Lookup(r.String())
ident = ir.NewIdent(pos, sym)
}
x := r.expr()
iface = x.Type()
tag = ir.NewTypeSwitchGuard(pos, ident, x)
} else {
tag = r.expr()
}
clauses := make([]*ir.CaseClause, r.Len())
for i := range clauses {
if i > 0 {
r.closeScope()
}
r.openScope()
pos := r.pos()
var cases []ir.Node
if iface != nil {
cases = make([]ir.Node, r.Len())
if len(cases) == 0 {
cases = nil // TODO(mdempsky): Unclear if this matters.
}
for i := range cases {
cases[i] = r.exprType(true)
}
} else {
cases = r.exprList()
}
clause := ir.NewCaseStmt(pos, cases, nil)
if ident != nil {
pos := r.pos()
typ := r.typ()
name := ir.NewNameAt(pos, ident.Sym())
setType(name, typ)
r.addLocal(name, ir.PAUTO)
clause.Var = name
name.Defn = tag
}
clause.Body = r.stmts()
clauses[i] = clause
}
if len(clauses) > 0 {
r.closeScope()
}
r.closeScope()
n := ir.NewSwitchStmt(pos, tag, clauses)
n.Label = label
if init != nil {
n.SetInit([]ir.Node{init})
}
return n
}
func (r *reader) label() *types.Sym {
r.Sync(pkgbits.SyncLabel)
name := r.String()
if r.inlCall != nil {
name = fmt.Sprintf("~%s·%d", name, inlgen)
}
return typecheck.Lookup(name)
}
func (r *reader) optLabel() *types.Sym {
r.Sync(pkgbits.SyncOptLabel)
if r.Bool() {
return r.label()
}
return nil
}
// initDefn marks the given names as declared by defn and populates
// its Init field with ODCL nodes. It then reports whether any names
// were so declared, which can be used to initialize defn.Def.
func (r *reader) initDefn(defn ir.InitNode, names []*ir.Name) bool {
if len(names) == 0 {
return false
}
init := make([]ir.Node, len(names))
for i, name := range names {
name.Defn = defn
init[i] = ir.NewDecl(name.Pos(), ir.ODCL, name)
}
defn.SetInit(init)
return true
}
// @@@ Expressions
// expr reads and returns a typechecked expression.
func (r *reader) expr() (res ir.Node) {
defer func() {
if res != nil && res.Typecheck() == 0 {
base.FatalfAt(res.Pos(), "%v missed typecheck", res)
}
}()
switch tag := codeExpr(r.Code(pkgbits.SyncExpr)); tag {
default:
panic("unhandled expression")
case exprNone:
return nil
case exprBlank:
// blank only allowed in LHS of assignments
// TODO(mdempsky): Handle directly in assignList instead?
return typecheck.AssignExpr(ir.BlankNode)
case exprLocal:
return typecheck.Expr(r.useLocal())
case exprName:
// Callee instead of Expr allows builtins
// TODO(mdempsky): Handle builtins directly in exprCall, like method calls?
return typecheck.Callee(r.obj())
case exprType:
return r.exprType(false)
case exprConst:
pos := r.pos()
typ := r.typ()
val := FixValue(typ, r.Value())
op := r.op()
orig := r.String()
return typecheck.Expr(OrigConst(pos, typ, val, op, orig))
case exprCompLit:
return r.compLit()
case exprFuncLit:
return r.funcLit()
case exprSelector:
x := r.expr()
pos := r.pos()
_, sym := r.selector()
// Method expression with derived receiver type.
if x.Op() == ir.ODYNAMICTYPE {
// TODO(mdempsky): Handle with runtime dictionary lookup.
n := ir.TypeNode(x.Type())
n.SetTypecheck(1)
x = n
}
n := typecheck.Expr(ir.NewSelectorExpr(pos, ir.OXDOT, x, sym)).(*ir.SelectorExpr)
if n.Op() == ir.OMETHVALUE {
wrapper := methodValueWrapper{
rcvr: n.X.Type(),
method: n.Selection,
}
if r.importedDef() {
haveMethodValueWrappers = append(haveMethodValueWrappers, wrapper)
} else {
needMethodValueWrappers = append(needMethodValueWrappers, wrapper)
}
}
return n
case exprIndex:
x := r.expr()
pos := r.pos()
index := r.expr()
return typecheck.Expr(ir.NewIndexExpr(pos, x, index))
case exprSlice:
x := r.expr()
pos := r.pos()
var index [3]ir.Node
for i := range index {
index[i] = r.expr()
}
op := ir.OSLICE
if index[2] != nil {
op = ir.OSLICE3
}
return typecheck.Expr(ir.NewSliceExpr(pos, op, x, index[0], index[1], index[2]))
case exprAssert:
x := r.expr()
pos := r.pos()
typ := r.exprType(false)
if typ, ok := typ.(*ir.DynamicType); ok && typ.Op() == ir.ODYNAMICTYPE {
assert := ir.NewDynamicTypeAssertExpr(pos, ir.ODYNAMICDOTTYPE, x, typ.RType)
assert.ITab = typ.ITab
return typed(typ.Type(), assert)
}
return typecheck.Expr(ir.NewTypeAssertExpr(pos, x, typ.Type()))
case exprUnaryOp:
op := r.op()
pos := r.pos()
x := r.expr()
switch op {
case ir.OADDR:
return typecheck.Expr(typecheck.NodAddrAt(pos, x))
case ir.ODEREF:
return typecheck.Expr(ir.NewStarExpr(pos, x))
}
return typecheck.Expr(ir.NewUnaryExpr(pos, op, x))
case exprBinaryOp:
op := r.op()
x := r.expr()
pos := r.pos()
y := r.expr()
switch op {
case ir.OANDAND, ir.OOROR:
return typecheck.Expr(ir.NewLogicalExpr(pos, op, x, y))
}
return typecheck.Expr(ir.NewBinaryExpr(pos, op, x, y))
case exprCall:
fun := r.expr()
if r.Bool() { // method call
pos := r.pos()
_, sym := r.selector()
fun = typecheck.Callee(ir.NewSelectorExpr(pos, ir.OXDOT, fun, sym))
}
pos := r.pos()
args := r.exprs()
dots := r.Bool()
return typecheck.Call(pos, fun, args, dots)
case exprConvert:
typ := r.typ()
pos := r.pos()
x := r.expr()
// TODO(mdempsky): Stop constructing expressions of untyped type.
x = typecheck.DefaultLit(x, typ)
if op, why := typecheck.Convertop(x.Op() == ir.OLITERAL, x.Type(), typ); op == ir.OXXX {
// types2 ensured that x is convertable to typ under standard Go
// semantics, but cmd/compile also disallows some conversions
// involving //go:notinheap.
//
// TODO(mdempsky): This can be removed after #46731 is implemented.
base.ErrorfAt(pos, "cannot convert %L to type %v%v", x, typ, why)
base.ErrorExit() // harsh, but prevents constructing invalid IR
}
return typecheck.Expr(ir.NewConvExpr(pos, ir.OCONV, typ, x))
}
}
func (r *reader) compLit() ir.Node {
r.Sync(pkgbits.SyncCompLit)
pos := r.pos()
typ0 := r.typ()
typ := typ0
if typ.IsPtr() {
typ = typ.Elem()
}
if typ.Kind() == types.TFORW {
base.FatalfAt(pos, "unresolved composite literal type: %v", typ)
}
isStruct := typ.Kind() == types.TSTRUCT
elems := make([]ir.Node, r.Len())
for i := range elems {
elemp := &elems[i]
if isStruct {
sk := ir.NewStructKeyExpr(r.pos(), typ.Field(r.Len()), nil)
*elemp, elemp = sk, &sk.Value
} else if r.Bool() {
kv := ir.NewKeyExpr(r.pos(), r.expr(), nil)
*elemp, elemp = kv, &kv.Value
}
*elemp = wrapName(r.pos(), r.expr())
}
lit := typecheck.Expr(ir.NewCompLitExpr(pos, ir.OCOMPLIT, typ, elems))
if typ0.IsPtr() {
lit = typecheck.Expr(typecheck.NodAddrAt(pos, lit))
lit.SetType(typ0)
}
return lit
}
func wrapName(pos src.XPos, x ir.Node) ir.Node {
// These nodes do not carry line numbers.
// Introduce a wrapper node to give them the correct line.
switch ir.Orig(x).Op() {
case ir.OTYPE, ir.OLITERAL:
if x.Sym() == nil {
break
}
fallthrough
case ir.ONAME, ir.ONONAME, ir.ONIL:
p := ir.NewParenExpr(pos, x)
p.SetImplicit(true)
return p
}
return x
}
func (r *reader) funcLit() ir.Node {
r.Sync(pkgbits.SyncFuncLit)
pos := r.pos()
xtype2 := r.signature(types.LocalPkg, nil)
opos := pos
fn := ir.NewClosureFunc(opos, r.curfn != nil)
clo := fn.OClosure
ir.NameClosure(clo, r.curfn)
setType(fn.Nname, xtype2)
typecheck.Func(fn)
setType(clo, fn.Type())
fn.ClosureVars = make([]*ir.Name, 0, r.Len())
for len(fn.ClosureVars) < cap(fn.ClosureVars) {
ir.NewClosureVar(r.pos(), fn, r.useLocal())
}
r.addBody(fn)
// TODO(mdempsky): Remove hard-coding of typecheck.Target.
return ir.UseClosure(clo, typecheck.Target)
}
func (r *reader) exprList() []ir.Node {
r.Sync(pkgbits.SyncExprList)
return r.exprs()
}
func (r *reader) exprs() []ir.Node {
r.Sync(pkgbits.SyncExprs)
nodes := make([]ir.Node, r.Len())
if len(nodes) == 0 {
return nil // TODO(mdempsky): Unclear if this matters.
}
for i := range nodes {
nodes[i] = r.expr()
}
return nodes
}
func (r *reader) exprType(nilOK bool) ir.Node {
r.Sync(pkgbits.SyncExprType)
if nilOK && r.Bool() {
return typecheck.Expr(types.BuiltinPkg.Lookup("nil").Def.(*ir.NilExpr))
}
pos := r.pos()
lsymPtr := func(lsym *obj.LSym) ir.Node {
return typecheck.Expr(typecheck.NodAddr(ir.NewLinksymExpr(pos, lsym, types.Types[types.TUINT8])))
}
var typ *types.Type
var rtype, itab ir.Node
if r.Bool() {
info := r.dict.itabs[r.Len()]
typ = info.typ
// TODO(mdempsky): Populate rtype unconditionally?
if typ.IsInterface() {
rtype = lsymPtr(info.lsym)
} else {
itab = lsymPtr(info.lsym)
}
} else {
info := r.typInfo()
typ = r.p.typIdx(info, r.dict, true)
if !info.derived {
// TODO(mdempsky): ir.TypeNode should probably return a typecheck'd node.
n := ir.TypeNode(typ)
n.SetTypecheck(1)
return n
}
rtype = lsymPtr(reflectdata.TypeLinksym(typ))
}
dt := ir.NewDynamicType(pos, rtype)
dt.ITab = itab
return typed(typ, dt)
}
func (r *reader) op() ir.Op {
r.Sync(pkgbits.SyncOp)
return ir.Op(r.Len())
}
// @@@ Package initialization
func (r *reader) pkgInit(self *types.Pkg, target *ir.Package) {
cgoPragmas := make([][]string, r.Len())
for i := range cgoPragmas {
cgoPragmas[i] = r.Strings()
}
target.CgoPragmas = cgoPragmas
r.pkgDecls(target)
r.Sync(pkgbits.SyncEOF)
}
func (r *reader) pkgDecls(target *ir.Package) {
r.Sync(pkgbits.SyncDecls)
for {
switch code := codeDecl(r.Code(pkgbits.SyncDecl)); code {
default:
panic(fmt.Sprintf("unhandled decl: %v", code))
case declEnd:
return
case declFunc:
names := r.pkgObjs(target)
assert(len(names) == 1)
target.Decls = append(target.Decls, names[0].Func)
case declMethod:
typ := r.typ()
_, sym := r.selector()
method := typecheck.Lookdot1(nil, sym, typ, typ.Methods(), 0)
target.Decls = append(target.Decls, method.Nname.(*ir.Name).Func)
case declVar:
pos := r.pos()
names := r.pkgObjs(target)
values := r.exprList()
if len(names) > 1 && len(values) == 1 {
as := ir.NewAssignListStmt(pos, ir.OAS2, nil, values)
for _, name := range names {
as.Lhs.Append(name)
name.Defn = as
}
target.Decls = append(target.Decls, as)
} else {
for i, name := range names {
as := ir.NewAssignStmt(pos, name, nil)
if i < len(values) {
as.Y = values[i]
}
name.Defn = as
target.Decls = append(target.Decls, as)
}
}
if n := r.Len(); n > 0 {
assert(len(names) == 1)
embeds := make([]ir.Embed, n)
for i := range embeds {
embeds[i] = ir.Embed{Pos: r.pos(), Patterns: r.Strings()}
}
names[0].Embed = &embeds
target.Embeds = append(target.Embeds, names[0])
}
case declOther:
r.pkgObjs(target)
}
}
}
func (r *reader) pkgObjs(target *ir.Package) []*ir.Name {
r.Sync(pkgbits.SyncDeclNames)
nodes := make([]*ir.Name, r.Len())
for i := range nodes {
r.Sync(pkgbits.SyncDeclName)
name := r.obj().(*ir.Name)
nodes[i] = name
sym := name.Sym()
if sym.IsBlank() {
continue
}
switch name.Class {
default:
base.FatalfAt(name.Pos(), "unexpected class: %v", name.Class)
case ir.PEXTERN:
target.Externs = append(target.Externs, name)
case ir.PFUNC:
assert(name.Type().Recv() == nil)
// TODO(mdempsky): Cleaner way to recognize init?
if strings.HasPrefix(sym.Name, "init.") {
target.Inits = append(target.Inits, name.Func)
}
}
if types.IsExported(sym.Name) {
assert(!sym.OnExportList())
target.Exports = append(target.Exports, name)
sym.SetOnExportList(true)
}
if base.Flag.AsmHdr != "" {
assert(!sym.Asm())
target.Asms = append(target.Asms, name)
sym.SetAsm(true)
}
}
return nodes
}
// @@@ Inlining
var inlgen = 0
func InlineCall(call *ir.CallExpr, fn *ir.Func, inlIndex int) *ir.InlinedCallExpr {
// TODO(mdempsky): Turn callerfn into an explicit parameter.
callerfn := ir.CurFunc
pri, ok := bodyReader[fn]
if !ok {
base.FatalfAt(call.Pos(), "missing function body for call to %v", fn)
}
if fn.Inl.Body == nil {
expandInline(fn, pri)
}
r := pri.asReader(pkgbits.RelocBody, pkgbits.SyncFuncBody)
// TODO(mdempsky): This still feels clumsy. Can we do better?
tmpfn := ir.NewFunc(fn.Pos())
tmpfn.Nname = ir.NewNameAt(fn.Nname.Pos(), callerfn.Sym())
tmpfn.Closgen = callerfn.Closgen
defer func() { callerfn.Closgen = tmpfn.Closgen }()
setType(tmpfn.Nname, fn.Type())
r.curfn = tmpfn
r.inlCaller = callerfn
r.inlCall = call
r.inlFunc = fn
r.inlTreeIndex = inlIndex
r.inlPosBases = make(map[*src.PosBase]*src.PosBase)
r.closureVars = make([]*ir.Name, len(r.inlFunc.ClosureVars))
for i, cv := range r.inlFunc.ClosureVars {
r.closureVars[i] = cv.Outer
}
r.funcargs(fn)
assert(r.Bool()) // have body
r.delayResults = fn.Inl.CanDelayResults
r.retlabel = typecheck.AutoLabel(".i")
inlgen++
init := ir.TakeInit(call)
// For normal function calls, the function callee expression
// may contain side effects. Make sure to preserve these,
// if necessary (#42703).
if call.Op() == ir.OCALLFUNC {
inline.CalleeEffects(&init, call.X)
}
var args ir.Nodes
if call.Op() == ir.OCALLMETH {
base.FatalfAt(call.Pos(), "OCALLMETH missed by typecheck")
}
args.Append(call.Args...)
// Create assignment to declare and initialize inlvars.
as2 := ir.NewAssignListStmt(call.Pos(), ir.OAS2, r.inlvars, args)
as2.Def = true
var as2init ir.Nodes
for _, name := range r.inlvars {
if ir.IsBlank(name) {
continue
}
// TODO(mdempsky): Use inlined position of name.Pos() instead?
name := name.(*ir.Name)
as2init.Append(ir.NewDecl(call.Pos(), ir.ODCL, name))
name.Defn = as2
}
as2.SetInit(as2init)
init.Append(typecheck.Stmt(as2))
if !r.delayResults {
// If not delaying retvars, declare and zero initialize the
// result variables now.
for _, name := range r.retvars {
// TODO(mdempsky): Use inlined position of name.Pos() instead?
name := name.(*ir.Name)
init.Append(ir.NewDecl(call.Pos(), ir.ODCL, name))
ras := ir.NewAssignStmt(call.Pos(), name, nil)
init.Append(typecheck.Stmt(ras))
}
}
// Add an inline mark just before the inlined body.
// This mark is inline in the code so that it's a reasonable spot
// to put a breakpoint. Not sure if that's really necessary or not
// (in which case it could go at the end of the function instead).
// Note issue 28603.
init.Append(ir.NewInlineMarkStmt(call.Pos().WithIsStmt(), int64(r.inlTreeIndex)))
nparams := len(r.curfn.Dcl)
ir.WithFunc(r.curfn, func() {
r.curfn.Body = r.stmts()
r.curfn.Endlineno = r.pos()
// TODO(mdempsky): This shouldn't be necessary. Inlining might
// read in new function/method declarations, which could
// potentially be recursively inlined themselves; but we shouldn't
// need to read in the non-inlined bodies for the declarations
// themselves. But currently it's an easy fix to #50552.
readBodies(typecheck.Target)
deadcode.Func(r.curfn)
// Replace any "return" statements within the function body.
var edit func(ir.Node) ir.Node
edit = func(n ir.Node) ir.Node {
if ret, ok := n.(*ir.ReturnStmt); ok {
n = typecheck.Stmt(r.inlReturn(ret))
}
ir.EditChildren(n, edit)
return n
}
edit(r.curfn)
})
body := ir.Nodes(r.curfn.Body)
// Quirkish: We need to eagerly prune variables added during
// inlining, but removed by deadcode.FuncBody above. Unused
// variables will get removed during stack frame layout anyway, but
// len(fn.Dcl) ends up influencing things like autotmp naming.
used := usedLocals(body)
for i, name := range r.curfn.Dcl {
if i < nparams || used.Has(name) {
name.Curfn = callerfn
callerfn.Dcl = append(callerfn.Dcl, name)
// Quirkish. TODO(mdempsky): Document why.
if name.AutoTemp() {
name.SetEsc(ir.EscUnknown)
if base.Flag.GenDwarfInl != 0 {
name.SetInlLocal(true)
} else {
name.SetPos(r.inlCall.Pos())
}
}
}
}
body.Append(ir.NewLabelStmt(call.Pos(), r.retlabel))
res := ir.NewInlinedCallExpr(call.Pos(), body, append([]ir.Node(nil), r.retvars...))
res.SetInit(init)
res.SetType(call.Type())
res.SetTypecheck(1)
// Inlining shouldn't add any functions to todoBodies.
assert(len(todoBodies) == 0)
return res
}
// inlReturn returns a statement that can substitute for the given
// return statement when inlining.
func (r *reader) inlReturn(ret *ir.ReturnStmt) *ir.BlockStmt {
pos := r.inlCall.Pos()
block := ir.TakeInit(ret)
if results := ret.Results; len(results) != 0 {
assert(len(r.retvars) == len(results))
as2 := ir.NewAssignListStmt(pos, ir.OAS2, append([]ir.Node(nil), r.retvars...), ret.Results)
if r.delayResults {
for _, name := range r.retvars {
// TODO(mdempsky): Use inlined position of name.Pos() instead?
name := name.(*ir.Name)
block.Append(ir.NewDecl(pos, ir.ODCL, name))
name.Defn = as2
}
}
block.Append(as2)
}
block.Append(ir.NewBranchStmt(pos, ir.OGOTO, r.retlabel))
return ir.NewBlockStmt(pos, block)
}
// expandInline reads in an extra copy of IR to populate
// fn.Inl.{Dcl,Body}.
func expandInline(fn *ir.Func, pri pkgReaderIndex) {
// TODO(mdempsky): Remove this function. It's currently needed by
// dwarfgen/dwarf.go:preInliningDcls, which requires fn.Inl.Dcl to
// create abstract function DIEs. But we should be able to provide it
// with the same information some other way.
fndcls := len(fn.Dcl)
topdcls := len(typecheck.Target.Decls)
tmpfn := ir.NewFunc(fn.Pos())
tmpfn.Nname = ir.NewNameAt(fn.Nname.Pos(), fn.Sym())
tmpfn.ClosureVars = fn.ClosureVars
{
r := pri.asReader(pkgbits.RelocBody, pkgbits.SyncFuncBody)
setType(tmpfn.Nname, fn.Type())
// Don't change parameter's Sym/Nname fields.
r.funarghack = true
r.funcBody(tmpfn)
ir.WithFunc(tmpfn, func() {
deadcode.Func(tmpfn)
})
}
used := usedLocals(tmpfn.Body)
for _, name := range tmpfn.Dcl {
if name.Class != ir.PAUTO || used.Has(name) {
name.Curfn = fn
fn.Inl.Dcl = append(fn.Inl.Dcl, name)
}
}
fn.Inl.Body = tmpfn.Body
// Double check that we didn't change fn.Dcl by accident.
assert(fndcls == len(fn.Dcl))
// typecheck.Stmts may have added function literals to
// typecheck.Target.Decls. Remove them again so we don't risk trying
// to compile them multiple times.
typecheck.Target.Decls = typecheck.Target.Decls[:topdcls]
}
// usedLocals returns a set of local variables that are used within body.
func usedLocals(body []ir.Node) ir.NameSet {
var used ir.NameSet
ir.VisitList(body, func(n ir.Node) {
if n, ok := n.(*ir.Name); ok && n.Op() == ir.ONAME && n.Class == ir.PAUTO {
used.Add(n)
}
})
return used
}
// @@@ Method wrappers
// needWrapperTypes lists types for which we may need to generate
// method wrappers.
var needWrapperTypes []*types.Type
// haveWrapperTypes lists types for which we know we already have
// method wrappers, because we found the type in an imported package.
var haveWrapperTypes []*types.Type
// needMethodValueWrappers lists methods for which we may need to
// generate method value wrappers.
var needMethodValueWrappers []methodValueWrapper
// haveMethodValueWrappers lists methods for which we know we already
// have method value wrappers, because we found it in an imported
// package.
var haveMethodValueWrappers []methodValueWrapper
type methodValueWrapper struct {
rcvr *types.Type
method *types.Field
}
func (r *reader) needWrapper(typ *types.Type) {
if typ.IsPtr() {
return
}
// If a type was found in an imported package, then we can assume
// that package (or one of its transitive dependencies) already
// generated method wrappers for it.
if r.importedDef() {
haveWrapperTypes = append(haveWrapperTypes, typ)
} else {
needWrapperTypes = append(needWrapperTypes, typ)
}
}
func (r *reader) importedDef() bool {
// If a type was found in an imported package, then we can assume
// that package (or one of its transitive dependencies) already
// generated method wrappers for it.
//
// Exception: If we're instantiating an imported generic type or
// function, we might be instantiating it with type arguments not
// previously seen before.
//
// TODO(mdempsky): Distinguish when a generic function or type was
// instantiated in an imported package so that we can add types to
// haveWrapperTypes instead.
return r.p != localPkgReader && !r.hasTypeParams()
}
func MakeWrappers(target *ir.Package) {
// Only unified IR emits its own wrappers.
if base.Debug.Unified == 0 {
return
}
// always generate a wrapper for error.Error (#29304)
needWrapperTypes = append(needWrapperTypes, types.ErrorType)
seen := make(map[string]*types.Type)
for _, typ := range haveWrapperTypes {
wrapType(typ, target, seen, false)
}
haveWrapperTypes = nil
for _, typ := range needWrapperTypes {
wrapType(typ, target, seen, true)
}
needWrapperTypes = nil
for _, wrapper := range haveMethodValueWrappers {
wrapMethodValue(wrapper.rcvr, wrapper.method, target, false)
}
haveMethodValueWrappers = nil
for _, wrapper := range needMethodValueWrappers {
wrapMethodValue(wrapper.rcvr, wrapper.method, target, true)
}
needMethodValueWrappers = nil
}
func wrapType(typ *types.Type, target *ir.Package, seen map[string]*types.Type, needed bool) {
key := typ.LinkString()
if prev := seen[key]; prev != nil {
if !types.Identical(typ, prev) {
base.Fatalf("collision: types %v and %v have link string %q", typ, prev, key)
}
return
}
seen[key] = typ
if !needed {
// Only called to add to 'seen'.
return
}
if !typ.IsInterface() {
typecheck.CalcMethods(typ)
}
for _, meth := range typ.AllMethods().Slice() {
if meth.Sym.IsBlank() || !meth.IsMethod() {
base.FatalfAt(meth.Pos, "invalid method: %v", meth)
}
methodWrapper(0, typ, meth, target)
// For non-interface types, we also want *T wrappers.
if !typ.IsInterface() {
methodWrapper(1, typ, meth, target)
// For not-in-heap types, *T is a scalar, not pointer shaped,
// so the interface wrappers use **T.
if typ.NotInHeap() {
methodWrapper(2, typ, meth, target)
}
}
}
}
func methodWrapper(derefs int, tbase *types.Type, method *types.Field, target *ir.Package) {
wrapper := tbase
for i := 0; i < derefs; i++ {
wrapper = types.NewPtr(wrapper)
}
sym := ir.MethodSym(wrapper, method.Sym)
base.Assertf(!sym.Siggen(), "already generated wrapper %v", sym)
sym.SetSiggen(true)
wrappee := method.Type.Recv().Type
if types.Identical(wrapper, wrappee) ||
!types.IsMethodApplicable(wrapper, method) ||
!reflectdata.NeedEmit(tbase) {
return
}
// TODO(mdempsky): Use method.Pos instead?
pos := base.AutogeneratedPos
fn := newWrapperFunc(pos, sym, wrapper, method)
var recv ir.Node = fn.Nname.Type().Recv().Nname.(*ir.Name)
// For simple *T wrappers around T methods, panicwrap produces a
// nicer panic message.
if wrapper.IsPtr() && types.Identical(wrapper.Elem(), wrappee) {
cond := ir.NewBinaryExpr(pos, ir.OEQ, recv, types.BuiltinPkg.Lookup("nil").Def.(ir.Node))
then := []ir.Node{ir.NewCallExpr(pos, ir.OCALL, typecheck.LookupRuntime("panicwrap"), nil)}
fn.Body.Append(ir.NewIfStmt(pos, cond, then, nil))
}
// typecheck will add one implicit deref, if necessary,
// but not-in-heap types require more for their **T wrappers.
for i := 1; i < derefs; i++ {
recv = Implicit(ir.NewStarExpr(pos, recv))
}
addTailCall(pos, fn, recv, method)
finishWrapperFunc(fn, target)
}
func wrapMethodValue(recvType *types.Type, method *types.Field, target *ir.Package, needed bool) {
sym := ir.MethodSymSuffix(recvType, method.Sym, "-fm")
if sym.Uniq() {
return
}
sym.SetUniq(true)
// TODO(mdempsky): Use method.Pos instead?
pos := base.AutogeneratedPos
fn := newWrapperFunc(pos, sym, nil, method)
sym.Def = fn.Nname
// Declare and initialize variable holding receiver.
recv := ir.NewHiddenParam(pos, fn, typecheck.Lookup(".this"), recvType)
if !needed {
typecheck.Func(fn)
return
}
addTailCall(pos, fn, recv, method)
finishWrapperFunc(fn, target)
}
func newWrapperFunc(pos src.XPos, sym *types.Sym, wrapper *types.Type, method *types.Field) *ir.Func {
fn := ir.NewFunc(pos)
fn.SetDupok(true) // TODO(mdempsky): Leave unset for local, non-generic wrappers?
name := ir.NewNameAt(pos, sym)
ir.MarkFunc(name)
name.Func = fn
name.Defn = fn
fn.Nname = name
sig := newWrapperType(wrapper, method)
setType(name, sig)
// TODO(mdempsky): De-duplicate with similar logic in funcargs.
defParams := func(class ir.Class, params *types.Type) {
for _, param := range params.FieldSlice() {
name := ir.NewNameAt(param.Pos, param.Sym)
name.Class = class
setType(name, param.Type)
name.Curfn = fn
fn.Dcl = append(fn.Dcl, name)
param.Nname = name
}
}
defParams(ir.PPARAM, sig.Recvs())
defParams(ir.PPARAM, sig.Params())
defParams(ir.PPARAMOUT, sig.Results())
return fn
}
func finishWrapperFunc(fn *ir.Func, target *ir.Package) {
typecheck.Func(fn)
ir.WithFunc(fn, func() {
typecheck.Stmts(fn.Body)
})
// We generate wrappers after the global inlining pass,
// so we're responsible for applying inlining ourselves here.
inline.InlineCalls(fn)
target.Decls = append(target.Decls, fn)
}
// newWrapperType returns a copy of the given signature type, but with
// the receiver parameter type substituted with recvType.
// If recvType is nil, newWrapperType returns a signature
// without a receiver parameter.
func newWrapperType(recvType *types.Type, method *types.Field) *types.Type {
clone := func(params []*types.Field) []*types.Field {
res := make([]*types.Field, len(params))
for i, param := range params {
sym := param.Sym
if sym == nil || sym.Name == "_" {
sym = typecheck.LookupNum(".anon", i)
}
res[i] = types.NewField(param.Pos, sym, param.Type)
res[i].SetIsDDD(param.IsDDD())
}
return res
}
sig := method.Type
var recv *types.Field
if recvType != nil {
recv = types.NewField(sig.Recv().Pos, typecheck.Lookup(".this"), recvType)
}
params := clone(sig.Params().FieldSlice())
results := clone(sig.Results().FieldSlice())
return types.NewSignature(types.NoPkg, recv, nil, params, results)
}
func addTailCall(pos src.XPos, fn *ir.Func, recv ir.Node, method *types.Field) {
sig := fn.Nname.Type()
args := make([]ir.Node, sig.NumParams())
for i, param := range sig.Params().FieldSlice() {
args[i] = param.Nname.(*ir.Name)
}
// TODO(mdempsky): Support creating OTAILCALL, when possible. See reflectdata.methodWrapper.
// Not urgent though, because tail calls are currently incompatible with regabi anyway.
fn.SetWrapper(true) // TODO(mdempsky): Leave unset for tail calls?
dot := ir.NewSelectorExpr(pos, ir.OXDOT, recv, method.Sym)
call := typecheck.Call(pos, dot, args, method.Type.IsVariadic()).(*ir.CallExpr)
if method.Type.NumResults() == 0 {
fn.Body.Append(call)
return
}
ret := ir.NewReturnStmt(pos, nil)
ret.Results = []ir.Node{call}
fn.Body.Append(ret)
}
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