go writer 源码
golang writer 代码
文件路径：/src/cmd/compile/internal/noder/writer.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 (
"fmt"
"internal/pkgbits"
"cmd/compile/internal/base"
"cmd/compile/internal/ir"
"cmd/compile/internal/syntax"
"cmd/compile/internal/types2"
)
type pkgWriter struct {
pkgbits.PkgEncoder
m posMap
curpkg *types2.Package
info *types2.Info
posBasesIdx map[*syntax.PosBase]pkgbits.Index
pkgsIdx map[*types2.Package]pkgbits.Index
typsIdx map[types2.Type]pkgbits.Index
globalsIdx map[types2.Object]pkgbits.Index
funDecls map[*types2.Func]*syntax.FuncDecl
typDecls map[*types2.TypeName]typeDeclGen
linknames map[types2.Object]string
cgoPragmas [][]string
}
func newPkgWriter(m posMap, pkg *types2.Package, info *types2.Info) *pkgWriter {
return &pkgWriter{
PkgEncoder: pkgbits.NewPkgEncoder(base.Debug.SyncFrames),
m: m,
curpkg: pkg,
info: info,
pkgsIdx: make(map[*types2.Package]pkgbits.Index),
globalsIdx: make(map[types2.Object]pkgbits.Index),
typsIdx: make(map[types2.Type]pkgbits.Index),
posBasesIdx: make(map[*syntax.PosBase]pkgbits.Index),
funDecls: make(map[*types2.Func]*syntax.FuncDecl),
typDecls: make(map[*types2.TypeName]typeDeclGen),
linknames: make(map[types2.Object]string),
}
}
func (pw *pkgWriter) errorf(p poser, msg string, args ...interface{}) {
base.ErrorfAt(pw.m.pos(p), msg, args...)
}
func (pw *pkgWriter) fatalf(p poser, msg string, args ...interface{}) {
base.FatalfAt(pw.m.pos(p), msg, args...)
}
func (pw *pkgWriter) unexpected(what string, p poser) {
pw.fatalf(p, "unexpected %s: %v (%T)", what, p, p)
}
type writer struct {
p *pkgWriter
pkgbits.Encoder
// TODO(mdempsky): We should be able to prune localsIdx whenever a
// scope closes, and then maybe we can just use the same map for
// storing the TypeParams too (as their TypeName instead).
// variables declared within this function
localsIdx map[*types2.Var]int
closureVars []posObj
closureVarsIdx map[*types2.Var]int
dict *writerDict
derived bool
}
// A writerDict tracks types and objects that are used by a declaration.
type writerDict struct {
implicits []*types2.TypeName
// derived is a slice of type indices for computing derived types
// (i.e., types that depend on the declaration's type parameters).
derived []derivedInfo
// derivedIdx maps a Type to its corresponding index within the
// derived slice, if present.
derivedIdx map[types2.Type]pkgbits.Index
// funcs lists references to generic functions that were
// instantiated with derived types (i.e., that require
// sub-dictionaries when called at run time).
funcs []objInfo
// itabs lists itabs that are needed for dynamic type assertions
// (including type switches).
itabs []itabInfo
}
// A derivedInfo represents a reference to an encoded generic Go type.
type derivedInfo struct {
idx pkgbits.Index
needed bool
}
// A typeInfo represents a reference to an encoded Go type.
//
// If derived is true, then the typeInfo represents a generic Go type
// that contains type parameters. In this case, idx is an index into
// the readerDict.derived{,Types} arrays.
//
// Otherwise, the typeInfo represents a non-generic Go type, and idx
// is an index into the reader.typs array instead.
type typeInfo struct {
idx pkgbits.Index
derived bool
}
type objInfo struct {
idx pkgbits.Index // index for the generic function declaration
explicits []typeInfo // info for the type arguments
}
type itabInfo struct {
typIdx pkgbits.Index // always a derived type index
iface typeInfo // always a non-empty interface type
}
func (info objInfo) anyDerived() bool {
for _, explicit := range info.explicits {
if explicit.derived {
return true
}
}
return false
}
func (info objInfo) equals(other objInfo) bool {
if info.idx != other.idx {
return false
}
assert(len(info.explicits) == len(other.explicits))
for i, targ := range info.explicits {
if targ != other.explicits[i] {
return false
}
}
return true
}
func (pw *pkgWriter) newWriter(k pkgbits.RelocKind, marker pkgbits.SyncMarker) *writer {
return &writer{
Encoder: pw.NewEncoder(k, marker),
p: pw,
}
}
// @@@ Positions
func (w *writer) pos(p poser) {
w.Sync(pkgbits.SyncPos)
pos := p.Pos()
// TODO(mdempsky): Track down the remaining cases here and fix them.
if !w.Bool(pos.IsKnown()) {
return
}
// TODO(mdempsky): Delta encoding. Also, if there's a b-side, update
// its position base too (but not vice versa!).
w.posBase(pos.Base())
w.Uint(pos.Line())
w.Uint(pos.Col())
}
func (w *writer) posBase(b *syntax.PosBase) {
w.Reloc(pkgbits.RelocPosBase, w.p.posBaseIdx(b))
}
func (pw *pkgWriter) posBaseIdx(b *syntax.PosBase) pkgbits.Index {
if idx, ok := pw.posBasesIdx[b]; ok {
return idx
}
w := pw.newWriter(pkgbits.RelocPosBase, pkgbits.SyncPosBase)
w.p.posBasesIdx[b] = w.Idx
w.String(trimFilename(b))
if !w.Bool(b.IsFileBase()) {
w.pos(b)
w.Uint(b.Line())
w.Uint(b.Col())
}
return w.Flush()
}
// @@@ Packages
func (w *writer) pkg(pkg *types2.Package) {
w.Sync(pkgbits.SyncPkg)
w.Reloc(pkgbits.RelocPkg, w.p.pkgIdx(pkg))
}
func (pw *pkgWriter) pkgIdx(pkg *types2.Package) pkgbits.Index {
if idx, ok := pw.pkgsIdx[pkg]; ok {
return idx
}
w := pw.newWriter(pkgbits.RelocPkg, pkgbits.SyncPkgDef)
pw.pkgsIdx[pkg] = w.Idx
// The universe and package unsafe need to be handled specially by
// importers anyway, so we serialize them using just their package
// path. This ensures that readers don't confuse them for
// user-defined packages.
switch pkg {
case nil: // universe
w.String("builtin") // same package path used by godoc
case types2.Unsafe:
w.String("unsafe")
default:
// TODO(mdempsky): Write out pkg.Path() for curpkg too.
var path string
if pkg != w.p.curpkg {
path = pkg.Path()
}
base.Assertf(path != "builtin" && path != "unsafe", "unexpected path for user-defined package: %q", path)
w.String(path)
w.String(pkg.Name())
w.Len(pkg.Height())
w.Len(len(pkg.Imports()))
for _, imp := range pkg.Imports() {
w.pkg(imp)
}
}
return w.Flush()
}
// @@@ Types
var anyTypeName = types2.Universe.Lookup("any").(*types2.TypeName)
func (w *writer) typ(typ types2.Type) {
w.typInfo(w.p.typIdx(typ, w.dict))
}
func (w *writer) typInfo(info typeInfo) {
w.Sync(pkgbits.SyncType)
if w.Bool(info.derived) {
w.Len(int(info.idx))
w.derived = true
} else {
w.Reloc(pkgbits.RelocType, info.idx)
}
}
// typIdx returns the index where the export data description of type
// can be read back in. If no such index exists yet, it's created.
//
// typIdx also reports whether typ is a derived type; that is, whether
// its identity depends on type parameters.
func (pw *pkgWriter) typIdx(typ types2.Type, dict *writerDict) typeInfo {
if idx, ok := pw.typsIdx[typ]; ok {
return typeInfo{idx: idx, derived: false}
}
if dict != nil {
if idx, ok := dict.derivedIdx[typ]; ok {
return typeInfo{idx: idx, derived: true}
}
}
w := pw.newWriter(pkgbits.RelocType, pkgbits.SyncTypeIdx)
w.dict = dict
switch typ := typ.(type) {
default:
base.Fatalf("unexpected type: %v (%T)", typ, typ)
case *types2.Basic:
switch kind := typ.Kind(); {
case kind == types2.Invalid:
base.Fatalf("unexpected types2.Invalid")
case types2.Typ[kind] == typ:
w.Code(pkgbits.TypeBasic)
w.Len(int(kind))
default:
// Handle "byte" and "rune" as references to their TypeName.
obj := types2.Universe.Lookup(typ.Name())
assert(obj.Type() == typ)
w.Code(pkgbits.TypeNamed)
w.obj(obj, nil)
}
case *types2.Named:
assert(typ.TypeParams().Len() == typ.TypeArgs().Len())
// TODO(mdempsky): Why do we need to loop here?
orig := typ
for orig.TypeArgs() != nil {
orig = orig.Origin()
}
w.Code(pkgbits.TypeNamed)
w.obj(orig.Obj(), typ.TypeArgs())
case *types2.TypeParam:
index := func() int {
for idx, name := range w.dict.implicits {
if name.Type().(*types2.TypeParam) == typ {
return idx
}
}
return len(w.dict.implicits) + typ.Index()
}()
w.derived = true
w.Code(pkgbits.TypeTypeParam)
w.Len(index)
case *types2.Array:
w.Code(pkgbits.TypeArray)
w.Uint64(uint64(typ.Len()))
w.typ(typ.Elem())
case *types2.Chan:
w.Code(pkgbits.TypeChan)
w.Len(int(typ.Dir()))
w.typ(typ.Elem())
case *types2.Map:
w.Code(pkgbits.TypeMap)
w.typ(typ.Key())
w.typ(typ.Elem())
case *types2.Pointer:
w.Code(pkgbits.TypePointer)
w.typ(typ.Elem())
case *types2.Signature:
base.Assertf(typ.TypeParams() == nil, "unexpected type params: %v", typ)
w.Code(pkgbits.TypeSignature)
w.signature(typ)
case *types2.Slice:
w.Code(pkgbits.TypeSlice)
w.typ(typ.Elem())
case *types2.Struct:
w.Code(pkgbits.TypeStruct)
w.structType(typ)
case *types2.Interface:
if typ == anyTypeName.Type() {
w.Code(pkgbits.TypeNamed)
w.obj(anyTypeName, nil)
break
}
w.Code(pkgbits.TypeInterface)
w.interfaceType(typ)
case *types2.Union:
w.Code(pkgbits.TypeUnion)
w.unionType(typ)
}
if w.derived {
idx := pkgbits.Index(len(dict.derived))
dict.derived = append(dict.derived, derivedInfo{idx: w.Flush()})
dict.derivedIdx[typ] = idx
return typeInfo{idx: idx, derived: true}
}
pw.typsIdx[typ] = w.Idx
return typeInfo{idx: w.Flush(), derived: false}
}
func (w *writer) structType(typ *types2.Struct) {
w.Len(typ.NumFields())
for i := 0; i < typ.NumFields(); i++ {
f := typ.Field(i)
w.pos(f)
w.selector(f)
w.typ(f.Type())
w.String(typ.Tag(i))
w.Bool(f.Embedded())
}
}
func (w *writer) unionType(typ *types2.Union) {
w.Len(typ.Len())
for i := 0; i < typ.Len(); i++ {
t := typ.Term(i)
w.Bool(t.Tilde())
w.typ(t.Type())
}
}
func (w *writer) interfaceType(typ *types2.Interface) {
w.Len(typ.NumExplicitMethods())
w.Len(typ.NumEmbeddeds())
if typ.NumExplicitMethods() == 0 && typ.NumEmbeddeds() == 1 {
w.Bool(typ.IsImplicit())
} else {
// Implicit interfaces always have 0 explicit methods and 1
// embedded type, so we skip writing out the implicit flag
// otherwise as a space optimization.
assert(!typ.IsImplicit())
}
for i := 0; i < typ.NumExplicitMethods(); i++ {
m := typ.ExplicitMethod(i)
sig := m.Type().(*types2.Signature)
assert(sig.TypeParams() == nil)
w.pos(m)
w.selector(m)
w.signature(sig)
}
for i := 0; i < typ.NumEmbeddeds(); i++ {
w.typ(typ.EmbeddedType(i))
}
}
func (w *writer) signature(sig *types2.Signature) {
w.Sync(pkgbits.SyncSignature)
w.params(sig.Params())
w.params(sig.Results())
w.Bool(sig.Variadic())
}
func (w *writer) params(typ *types2.Tuple) {
w.Sync(pkgbits.SyncParams)
w.Len(typ.Len())
for i := 0; i < typ.Len(); i++ {
w.param(typ.At(i))
}
}
func (w *writer) param(param *types2.Var) {
w.Sync(pkgbits.SyncParam)
w.pos(param)
w.localIdent(param)
w.typ(param.Type())
}
// @@@ Objects
func (w *writer) obj(obj types2.Object, explicits *types2.TypeList) {
explicitInfos := make([]typeInfo, explicits.Len())
for i := range explicitInfos {
explicitInfos[i] = w.p.typIdx(explicits.At(i), w.dict)
}
info := objInfo{idx: w.p.objIdx(obj), explicits: explicitInfos}
if _, ok := obj.(*types2.Func); ok && info.anyDerived() {
idx := -1
for i, prev := range w.dict.funcs {
if prev.equals(info) {
idx = i
}
}
if idx < 0 {
idx = len(w.dict.funcs)
w.dict.funcs = append(w.dict.funcs, info)
}
// TODO(mdempsky): Push up into expr; this shouldn't appear
// outside of expression context.
w.Sync(pkgbits.SyncObject)
w.Bool(true)
w.Len(idx)
return
}
// TODO(mdempsky): Push up into typIdx; this shouldn't be needed
// except while writing out types.
if isDefinedType(obj) && obj.Pkg() == w.p.curpkg {
decl, ok := w.p.typDecls[obj.(*types2.TypeName)]
assert(ok)
if len(decl.implicits) != 0 {
w.derived = true
}
}
w.Sync(pkgbits.SyncObject)
w.Bool(false)
w.Reloc(pkgbits.RelocObj, info.idx)
w.Len(len(info.explicits))
for _, info := range info.explicits {
w.typInfo(info)
}
}
func (pw *pkgWriter) objIdx(obj types2.Object) pkgbits.Index {
if idx, ok := pw.globalsIdx[obj]; ok {
return idx
}
dict := &writerDict{
derivedIdx: make(map[types2.Type]pkgbits.Index),
}
if isDefinedType(obj) && obj.Pkg() == pw.curpkg {
decl, ok := pw.typDecls[obj.(*types2.TypeName)]
assert(ok)
dict.implicits = decl.implicits
}
w := pw.newWriter(pkgbits.RelocObj, pkgbits.SyncObject1)
wext := pw.newWriter(pkgbits.RelocObjExt, pkgbits.SyncObject1)
wname := pw.newWriter(pkgbits.RelocName, pkgbits.SyncObject1)
wdict := pw.newWriter(pkgbits.RelocObjDict, pkgbits.SyncObject1)
pw.globalsIdx[obj] = w.Idx // break cycles
assert(wext.Idx == w.Idx)
assert(wname.Idx == w.Idx)
assert(wdict.Idx == w.Idx)
w.dict = dict
wext.dict = dict
code := w.doObj(wext, obj)
w.Flush()
wext.Flush()
wname.qualifiedIdent(obj)
wname.Code(code)
wname.Flush()
wdict.objDict(obj, w.dict)
wdict.Flush()
return w.Idx
}
func (w *writer) doObj(wext *writer, obj types2.Object) pkgbits.CodeObj {
if obj.Pkg() != w.p.curpkg {
return pkgbits.ObjStub
}
switch obj := obj.(type) {
default:
w.p.unexpected("object", obj)
panic("unreachable")
case *types2.Const:
w.pos(obj)
w.typ(obj.Type())
w.Value(obj.Val())
return pkgbits.ObjConst
case *types2.Func:
decl, ok := w.p.funDecls[obj]
assert(ok)
sig := obj.Type().(*types2.Signature)
w.pos(obj)
w.typeParamNames(sig.TypeParams())
w.signature(sig)
w.pos(decl)
wext.funcExt(obj)
return pkgbits.ObjFunc
case *types2.TypeName:
decl, ok := w.p.typDecls[obj]
assert(ok)
if obj.IsAlias() {
w.pos(obj)
w.typ(obj.Type())
return pkgbits.ObjAlias
}
named := obj.Type().(*types2.Named)
assert(named.TypeArgs() == nil)
w.pos(obj)
w.typeParamNames(named.TypeParams())
wext.typeExt(obj)
w.typExpr(decl.Type)
w.Len(named.NumMethods())
for i := 0; i < named.NumMethods(); i++ {
w.method(wext, named.Method(i))
}
return pkgbits.ObjType
case *types2.Var:
w.pos(obj)
w.typ(obj.Type())
wext.varExt(obj)
return pkgbits.ObjVar
}
}
// typExpr writes the type represented by the given expression.
func (w *writer) typExpr(expr syntax.Expr) {
tv, ok := w.p.info.Types[expr]
assert(ok)
assert(tv.IsType())
w.typ(tv.Type)
}
// objDict writes the dictionary needed for reading the given object.
func (w *writer) objDict(obj types2.Object, dict *writerDict) {
// TODO(mdempsky): Split objDict into multiple entries? reader.go
// doesn't care about the type parameter bounds, and reader2.go
// doesn't care about referenced functions.
w.dict = dict // TODO(mdempsky): This is a bit sketchy.
w.Len(len(dict.implicits))
tparams := objTypeParams(obj)
ntparams := tparams.Len()
w.Len(ntparams)
for i := 0; i < ntparams; i++ {
w.typ(tparams.At(i).Constraint())
}
nderived := len(dict.derived)
w.Len(nderived)
for _, typ := range dict.derived {
w.Reloc(pkgbits.RelocType, typ.idx)
w.Bool(typ.needed)
}
nfuncs := len(dict.funcs)
w.Len(nfuncs)
for _, fn := range dict.funcs {
w.Reloc(pkgbits.RelocObj, fn.idx)
w.Len(len(fn.explicits))
for _, targ := range fn.explicits {
w.typInfo(targ)
}
}
nitabs := len(dict.itabs)
w.Len(nitabs)
for _, itab := range dict.itabs {
w.Len(int(itab.typIdx))
w.typInfo(itab.iface)
}
assert(len(dict.derived) == nderived)
assert(len(dict.funcs) == nfuncs)
}
func (w *writer) typeParamNames(tparams *types2.TypeParamList) {
w.Sync(pkgbits.SyncTypeParamNames)
ntparams := tparams.Len()
for i := 0; i < ntparams; i++ {
tparam := tparams.At(i).Obj()
w.pos(tparam)
w.localIdent(tparam)
}
}
func (w *writer) method(wext *writer, meth *types2.Func) {
decl, ok := w.p.funDecls[meth]
assert(ok)
sig := meth.Type().(*types2.Signature)
w.Sync(pkgbits.SyncMethod)
w.pos(meth)
w.selector(meth)
w.typeParamNames(sig.RecvTypeParams())
w.param(sig.Recv())
w.signature(sig)
w.pos(decl) // XXX: Hack to workaround linker limitations.
wext.funcExt(meth)
}
// qualifiedIdent writes out the name of an object declared at package
// scope. (For now, it's also used to refer to local defined types.)
func (w *writer) qualifiedIdent(obj types2.Object) {
w.Sync(pkgbits.SyncSym)
name := obj.Name()
if isDefinedType(obj) && obj.Pkg() == w.p.curpkg {
decl, ok := w.p.typDecls[obj.(*types2.TypeName)]
assert(ok)
if decl.gen != 0 {
// TODO(mdempsky): Find a better solution than embedding middle
// dot in the symbol name; this is terrible.
name = fmt.Sprintf("%s·%v", name, decl.gen)
}
}
w.pkg(obj.Pkg())
w.String(name)
}
// TODO(mdempsky): We should be able to omit pkg from both localIdent
// and selector, because they should always be known from context.
// However, past frustrations with this optimization in iexport make
// me a little nervous to try it again.
// localIdent writes the name of a locally declared object (i.e.,
// objects that can only be accessed by name, within the context of a
// particular function).
func (w *writer) localIdent(obj types2.Object) {
assert(!isGlobal(obj))
w.Sync(pkgbits.SyncLocalIdent)
w.pkg(obj.Pkg())
w.String(obj.Name())
}
// selector writes the name of a field or method (i.e., objects that
// can only be accessed using selector expressions).
func (w *writer) selector(obj types2.Object) {
w.Sync(pkgbits.SyncSelector)
w.pkg(obj.Pkg())
w.String(obj.Name())
}
// @@@ Compiler extensions
func (w *writer) funcExt(obj *types2.Func) {
decl, ok := w.p.funDecls[obj]
assert(ok)
// TODO(mdempsky): Extend these pragma validation flags to account
// for generics. E.g., linkname probably doesn't make sense at
// least.
pragma := asPragmaFlag(decl.Pragma)
if pragma&ir.Systemstack != 0 && pragma&ir.Nosplit != 0 {
w.p.errorf(decl, "go:nosplit and go:systemstack cannot be combined")
}
if decl.Body != nil {
if pragma&ir.Noescape != 0 {
w.p.errorf(decl, "can only use //go:noescape with external func implementations")
}
if (pragma&ir.UintptrKeepAlive != 0 && pragma&ir.UintptrEscapes == 0) && pragma&ir.Nosplit == 0 {
// Stack growth can't handle uintptr arguments that may
// be pointers (as we don't know which are pointers
// when creating the stack map). Thus uintptrkeepalive
// functions (and all transitive callees) must be
// nosplit.
//
// N.B. uintptrescapes implies uintptrkeepalive but it
// is OK since the arguments must escape to the heap.
//
// TODO(prattmic): Add recursive nosplit check of callees.
// TODO(prattmic): Functions with no body (i.e.,
// assembly) must also be nosplit, but we can't check
// that here.
w.p.errorf(decl, "go:uintptrkeepalive requires go:nosplit")
}
} else {
if base.Flag.Complete || decl.Name.Value == "init" {
// Linknamed functions are allowed to have no body. Hopefully
// the linkname target has a body. See issue 23311.
if _, ok := w.p.linknames[obj]; !ok {
w.p.errorf(decl, "missing function body")
}
}
}
sig, block := obj.Type().(*types2.Signature), decl.Body
body, closureVars := w.p.bodyIdx(w.p.curpkg, sig, block, w.dict)
assert(len(closureVars) == 0)
w.Sync(pkgbits.SyncFuncExt)
w.pragmaFlag(pragma)
w.linkname(obj)
w.Bool(false) // stub extension
w.Reloc(pkgbits.RelocBody, body)
w.Sync(pkgbits.SyncEOF)
}
func (w *writer) typeExt(obj *types2.TypeName) {
decl, ok := w.p.typDecls[obj]
assert(ok)
w.Sync(pkgbits.SyncTypeExt)
w.pragmaFlag(asPragmaFlag(decl.Pragma))
// No LSym.SymIdx info yet.
w.Int64(-1)
w.Int64(-1)
}
func (w *writer) varExt(obj *types2.Var) {
w.Sync(pkgbits.SyncVarExt)
w.linkname(obj)
}
func (w *writer) linkname(obj types2.Object) {
w.Sync(pkgbits.SyncLinkname)
w.Int64(-1)
w.String(w.p.linknames[obj])
}
func (w *writer) pragmaFlag(p ir.PragmaFlag) {
w.Sync(pkgbits.SyncPragma)
w.Int(int(p))
}
// @@@ Function bodies
func (pw *pkgWriter) bodyIdx(pkg *types2.Package, sig *types2.Signature, block *syntax.BlockStmt, dict *writerDict) (idx pkgbits.Index, closureVars []posObj) {
w := pw.newWriter(pkgbits.RelocBody, pkgbits.SyncFuncBody)
w.dict = dict
w.funcargs(sig)
if w.Bool(block != nil) {
w.stmts(block.List)
w.pos(block.Rbrace)
}
return w.Flush(), w.closureVars
}
func (w *writer) funcargs(sig *types2.Signature) {
do := func(params *types2.Tuple, result bool) {
for i := 0; i < params.Len(); i++ {
w.funcarg(params.At(i), result)
}
}
if recv := sig.Recv(); recv != nil {
w.funcarg(recv, false)
}
do(sig.Params(), false)
do(sig.Results(), true)
}
func (w *writer) funcarg(param *types2.Var, result bool) {
if param.Name() != "" || result {
w.addLocal(param)
}
}
func (w *writer) addLocal(obj *types2.Var) {
w.Sync(pkgbits.SyncAddLocal)
idx := len(w.localsIdx)
if pkgbits.EnableSync {
w.Int(idx)
}
if w.localsIdx == nil {
w.localsIdx = make(map[*types2.Var]int)
}
w.localsIdx[obj] = idx
}
func (w *writer) useLocal(pos syntax.Pos, obj *types2.Var) {
w.Sync(pkgbits.SyncUseObjLocal)
if idx, ok := w.localsIdx[obj]; w.Bool(ok) {
w.Len(idx)
return
}
idx, ok := w.closureVarsIdx[obj]
if !ok {
if w.closureVarsIdx == nil {
w.closureVarsIdx = make(map[*types2.Var]int)
}
idx = len(w.closureVars)
w.closureVars = append(w.closureVars, posObj{pos, obj})
w.closureVarsIdx[obj] = idx
}
w.Len(idx)
}
func (w *writer) openScope(pos syntax.Pos) {
w.Sync(pkgbits.SyncOpenScope)
w.pos(pos)
}
func (w *writer) closeScope(pos syntax.Pos) {
w.Sync(pkgbits.SyncCloseScope)
w.pos(pos)
w.closeAnotherScope()
}
func (w *writer) closeAnotherScope() {
w.Sync(pkgbits.SyncCloseAnotherScope)
}
// @@@ Statements
func (w *writer) stmt(stmt syntax.Stmt) {
var stmts []syntax.Stmt
if stmt != nil {
stmts = []syntax.Stmt{stmt}
}
w.stmts(stmts)
}
func (w *writer) stmts(stmts []syntax.Stmt) {
w.Sync(pkgbits.SyncStmts)
for _, stmt := range stmts {
w.stmt1(stmt)
}
w.Code(stmtEnd)
w.Sync(pkgbits.SyncStmtsEnd)
}
func (w *writer) stmt1(stmt syntax.Stmt) {
switch stmt := stmt.(type) {
default:
w.p.unexpected("statement", stmt)
case nil, *syntax.EmptyStmt:
return
case *syntax.AssignStmt:
switch {
case stmt.Rhs == nil:
w.Code(stmtIncDec)
w.op(binOps[stmt.Op])
w.expr(stmt.Lhs)
w.pos(stmt)
case stmt.Op != 0 && stmt.Op != syntax.Def:
w.Code(stmtAssignOp)
w.op(binOps[stmt.Op])
w.expr(stmt.Lhs)
w.pos(stmt)
w.expr(stmt.Rhs)
default:
w.Code(stmtAssign)
w.pos(stmt)
w.exprList(stmt.Rhs)
w.assignList(stmt.Lhs)
}
case *syntax.BlockStmt:
w.Code(stmtBlock)
w.blockStmt(stmt)
case *syntax.BranchStmt:
w.Code(stmtBranch)
w.pos(stmt)
w.op(branchOps[stmt.Tok])
w.optLabel(stmt.Label)
case *syntax.CallStmt:
w.Code(stmtCall)
w.pos(stmt)
w.op(callOps[stmt.Tok])
w.expr(stmt.Call)
case *syntax.DeclStmt:
for _, decl := range stmt.DeclList {
w.declStmt(decl)
}
case *syntax.ExprStmt:
w.Code(stmtExpr)
w.expr(stmt.X)
case *syntax.ForStmt:
w.Code(stmtFor)
w.forStmt(stmt)
case *syntax.IfStmt:
w.Code(stmtIf)
w.ifStmt(stmt)
case *syntax.LabeledStmt:
w.Code(stmtLabel)
w.pos(stmt)
w.label(stmt.Label)
w.stmt1(stmt.Stmt)
case *syntax.ReturnStmt:
w.Code(stmtReturn)
w.pos(stmt)
w.exprList(stmt.Results)
case *syntax.SelectStmt:
w.Code(stmtSelect)
w.selectStmt(stmt)
case *syntax.SendStmt:
w.Code(stmtSend)
w.pos(stmt)
w.expr(stmt.Chan)
w.expr(stmt.Value)
case *syntax.SwitchStmt:
w.Code(stmtSwitch)
w.switchStmt(stmt)
}
}
func (w *writer) assignList(expr syntax.Expr) {
exprs := unpackListExpr(expr)
w.Len(len(exprs))
for _, expr := range exprs {
if name, ok := expr.(*syntax.Name); ok && name.Value != "_" {
if obj, ok := w.p.info.Defs[name]; ok {
obj := obj.(*types2.Var)
w.Bool(true)
w.pos(obj)
w.localIdent(obj)
w.typ(obj.Type())
// TODO(mdempsky): Minimize locals index size by deferring
// this until the variables actually come into scope.
w.addLocal(obj)
continue
}
}
w.Bool(false)
w.expr(expr)
}
}
func (w *writer) declStmt(decl syntax.Decl) {
switch decl := decl.(type) {
default:
w.p.unexpected("declaration", decl)
case *syntax.ConstDecl, *syntax.TypeDecl:
case *syntax.VarDecl:
w.Code(stmtAssign)
w.pos(decl)
w.exprList(decl.Values)
w.assignList(namesAsExpr(decl.NameList))
}
}
func (w *writer) blockStmt(stmt *syntax.BlockStmt) {
w.Sync(pkgbits.SyncBlockStmt)
w.openScope(stmt.Pos())
w.stmts(stmt.List)
w.closeScope(stmt.Rbrace)
}
func (w *writer) forStmt(stmt *syntax.ForStmt) {
w.Sync(pkgbits.SyncForStmt)
w.openScope(stmt.Pos())
if rang, ok := stmt.Init.(*syntax.RangeClause); w.Bool(ok) {
w.pos(rang)
w.expr(rang.X)
w.assignList(rang.Lhs)
} else {
w.pos(stmt)
w.stmt(stmt.Init)
w.expr(stmt.Cond)
w.stmt(stmt.Post)
}
w.blockStmt(stmt.Body)
w.closeAnotherScope()
}
func (w *writer) ifStmt(stmt *syntax.IfStmt) {
w.Sync(pkgbits.SyncIfStmt)
w.openScope(stmt.Pos())
w.pos(stmt)
w.stmt(stmt.Init)
w.expr(stmt.Cond)
w.blockStmt(stmt.Then)
w.stmt(stmt.Else)
w.closeAnotherScope()
}
func (w *writer) selectStmt(stmt *syntax.SelectStmt) {
w.Sync(pkgbits.SyncSelectStmt)
w.pos(stmt)
w.Len(len(stmt.Body))
for i, clause := range stmt.Body {
if i > 0 {
w.closeScope(clause.Pos())
}
w.openScope(clause.Pos())
w.pos(clause)
w.stmt(clause.Comm)
w.stmts(clause.Body)
}
if len(stmt.Body) > 0 {
w.closeScope(stmt.Rbrace)
}
}
func (w *writer) switchStmt(stmt *syntax.SwitchStmt) {
w.Sync(pkgbits.SyncSwitchStmt)
w.openScope(stmt.Pos())
w.pos(stmt)
w.stmt(stmt.Init)
var iface types2.Type
if guard, ok := stmt.Tag.(*syntax.TypeSwitchGuard); w.Bool(ok) {
tv, ok := w.p.info.Types[guard.X]
assert(ok && tv.IsValue())
iface = tv.Type
w.pos(guard)
if tag := guard.Lhs; w.Bool(tag != nil) {
w.pos(tag)
w.String(tag.Value)
}
w.expr(guard.X)
} else {
w.expr(stmt.Tag)
}
w.Len(len(stmt.Body))
for i, clause := range stmt.Body {
if i > 0 {
w.closeScope(clause.Pos())
}
w.openScope(clause.Pos())
w.pos(clause)
if iface != nil {
cases := unpackListExpr(clause.Cases)
w.Len(len(cases))
for _, cas := range cases {
w.exprType(iface, cas, true)
}
} else {
w.exprList(clause.Cases)
}
if obj, ok := w.p.info.Implicits[clause]; ok {
// TODO(mdempsky): These pos details are quirkish, but also
// necessary so the variable's position is correct for DWARF
// scope assignment later. It would probably be better for us to
// instead just set the variable's DWARF scoping info earlier so
// we can give it the correct position information.
pos := clause.Pos()
if typs := unpackListExpr(clause.Cases); len(typs) != 0 {
pos = typeExprEndPos(typs[len(typs)-1])
}
w.pos(pos)
obj := obj.(*types2.Var)
w.typ(obj.Type())
w.addLocal(obj)
}
w.stmts(clause.Body)
}
if len(stmt.Body) > 0 {
w.closeScope(stmt.Rbrace)
}
w.closeScope(stmt.Rbrace)
}
func (w *writer) label(label *syntax.Name) {
w.Sync(pkgbits.SyncLabel)
// TODO(mdempsky): Replace label strings with dense indices.
w.String(label.Value)
}
func (w *writer) optLabel(label *syntax.Name) {
w.Sync(pkgbits.SyncOptLabel)
if w.Bool(label != nil) {
w.label(label)
}
}
// @@@ Expressions
func (w *writer) expr(expr syntax.Expr) {
expr = unparen(expr) // skip parens; unneeded after typecheck
obj, inst := lookupObj(w.p.info, expr)
targs := inst.TypeArgs
if tv, ok := w.p.info.Types[expr]; ok {
// TODO(mdempsky): Be more judicious about which types are marked as "needed".
if inst.Type != nil {
w.needType(inst.Type)
} else {
w.needType(tv.Type)
}
if tv.IsType() {
w.Code(exprType)
w.exprType(nil, expr, false)
return
}
if tv.Value != nil {
w.Code(exprConst)
w.pos(expr)
w.typ(tv.Type)
w.Value(tv.Value)
// TODO(mdempsky): These details are only important for backend
// diagnostics. Explore writing them out separately.
w.op(constExprOp(expr))
w.String(syntax.String(expr))
return
}
}
if obj != nil {
if isGlobal(obj) {
w.Code(exprName)
w.obj(obj, targs)
return
}
obj := obj.(*types2.Var)
assert(!obj.IsField())
assert(targs.Len() == 0)
w.Code(exprLocal)
w.useLocal(expr.Pos(), obj)
return
}
switch expr := expr.(type) {
default:
w.p.unexpected("expression", expr)
case nil: // absent slice index, for condition, or switch tag
w.Code(exprNone)
case *syntax.Name:
assert(expr.Value == "_")
w.Code(exprBlank)
case *syntax.CompositeLit:
w.Code(exprCompLit)
w.compLit(expr)
case *syntax.FuncLit:
w.Code(exprFuncLit)
w.funcLit(expr)
case *syntax.SelectorExpr:
sel, ok := w.p.info.Selections[expr]
assert(ok)
w.Code(exprSelector)
w.expr(expr.X)
w.pos(expr)
w.selector(sel.Obj())
case *syntax.IndexExpr:
tv, ok := w.p.info.Types[expr.Index]
assert(ok && tv.IsValue())
w.Code(exprIndex)
w.expr(expr.X)
w.pos(expr)
w.expr(expr.Index)
case *syntax.SliceExpr:
w.Code(exprSlice)
w.expr(expr.X)
w.pos(expr)
for _, n := range &expr.Index {
w.expr(n)
}
case *syntax.AssertExpr:
tv, ok := w.p.info.Types[expr.X]
assert(ok && tv.IsValue())
w.Code(exprAssert)
w.expr(expr.X)
w.pos(expr)
w.exprType(tv.Type, expr.Type, false)
case *syntax.Operation:
if expr.Y == nil {
w.Code(exprUnaryOp)
w.op(unOps[expr.Op])
w.pos(expr)
w.expr(expr.X)
break
}
w.Code(exprBinaryOp)
w.op(binOps[expr.Op])
w.expr(expr.X)
w.pos(expr)
w.expr(expr.Y)
case *syntax.CallExpr:
tv, ok := w.p.info.Types[expr.Fun]
assert(ok)
if tv.IsType() {
assert(len(expr.ArgList) == 1)
assert(!expr.HasDots)
w.Code(exprConvert)
w.typ(tv.Type)
w.pos(expr)
w.expr(expr.ArgList[0])
break
}
writeFunExpr := func() {
if selector, ok := unparen(expr.Fun).(*syntax.SelectorExpr); ok {
if sel, ok := w.p.info.Selections[selector]; ok && sel.Kind() == types2.MethodVal {
w.expr(selector.X)
w.Bool(true) // method call
w.pos(selector)
w.selector(sel.Obj())
return
}
}
w.expr(expr.Fun)
w.Bool(false) // not a method call (i.e., normal function call)
}
w.Code(exprCall)
writeFunExpr()
w.pos(expr)
w.exprs(expr.ArgList)
w.Bool(expr.HasDots)
}
}
func (w *writer) compLit(lit *syntax.CompositeLit) {
tv, ok := w.p.info.Types[lit]
assert(ok)
w.Sync(pkgbits.SyncCompLit)
w.pos(lit)
w.typ(tv.Type)
typ := tv.Type
if ptr, ok := types2.CoreType(typ).(*types2.Pointer); ok {
typ = ptr.Elem()
}
str, isStruct := types2.CoreType(typ).(*types2.Struct)
w.Len(len(lit.ElemList))
for i, elem := range lit.ElemList {
if isStruct {
if kv, ok := elem.(*syntax.KeyValueExpr); ok {
// use position of expr.Key rather than of elem (which has position of ':')
w.pos(kv.Key)
w.Len(fieldIndex(w.p.info, str, kv.Key.(*syntax.Name)))
elem = kv.Value
} else {
w.pos(elem)
w.Len(i)
}
} else {
if kv, ok := elem.(*syntax.KeyValueExpr); w.Bool(ok) {
// use position of expr.Key rather than of elem (which has position of ':')
w.pos(kv.Key)
w.expr(kv.Key)
elem = kv.Value
}
}
w.pos(elem)
w.expr(elem)
}
}
func (w *writer) funcLit(expr *syntax.FuncLit) {
tv, ok := w.p.info.Types[expr]
assert(ok)
sig := tv.Type.(*types2.Signature)
body, closureVars := w.p.bodyIdx(w.p.curpkg, sig, expr.Body, w.dict)
w.Sync(pkgbits.SyncFuncLit)
w.pos(expr)
w.signature(sig)
w.Len(len(closureVars))
for _, cv := range closureVars {
w.pos(cv.pos)
w.useLocal(cv.pos, cv.obj)
}
w.Reloc(pkgbits.RelocBody, body)
}
type posObj struct {
pos syntax.Pos
obj *types2.Var
}
func (w *writer) exprList(expr syntax.Expr) {
w.Sync(pkgbits.SyncExprList)
w.exprs(unpackListExpr(expr))
}
func (w *writer) exprs(exprs []syntax.Expr) {
if len(exprs) == 0 {
assert(exprs == nil)
}
w.Sync(pkgbits.SyncExprs)
w.Len(len(exprs))
for _, expr := range exprs {
w.expr(expr)
}
}
func (w *writer) exprType(iface types2.Type, typ syntax.Expr, nilOK bool) {
base.Assertf(iface == nil || isInterface(iface), "%v must be nil or an interface type", iface)
tv, ok := w.p.info.Types[typ]
assert(ok)
w.Sync(pkgbits.SyncExprType)
if nilOK && w.Bool(tv.IsNil()) {
return
}
assert(tv.IsType())
info := w.p.typIdx(tv.Type, w.dict)
w.pos(typ)
if w.Bool(info.derived && iface != nil && !iface.Underlying().(*types2.Interface).Empty()) {
ifaceInfo := w.p.typIdx(iface, w.dict)
idx := -1
for i, itab := range w.dict.itabs {
if itab.typIdx == info.idx && itab.iface == ifaceInfo {
idx = i
}
}
if idx < 0 {
idx = len(w.dict.itabs)
w.dict.itabs = append(w.dict.itabs, itabInfo{typIdx: info.idx, iface: ifaceInfo})
}
w.Len(idx)
return
}
w.typInfo(info)
}
func isInterface(typ types2.Type) bool {
if _, ok := typ.(*types2.TypeParam); ok {
// typ is a type parameter and may be instantiated as either a
// concrete or interface type, so the writer can't depend on
// knowing this.
base.Fatalf("%v is a type parameter", typ)
}
_, ok := typ.Underlying().(*types2.Interface)
return ok
}
func (w *writer) op(op ir.Op) {
// TODO(mdempsky): Remove in favor of explicit codes? Would make
// export data more stable against internal refactorings, but low
// priority at the moment.
assert(op != 0)
w.Sync(pkgbits.SyncOp)
w.Len(int(op))
}
func (w *writer) needType(typ types2.Type) {
// Decompose tuple into component element types.
if typ, ok := typ.(*types2.Tuple); ok {
for i := 0; i < typ.Len(); i++ {
w.needType(typ.At(i).Type())
}
return
}
if info := w.p.typIdx(typ, w.dict); info.derived {
w.dict.derived[info.idx].needed = true
}
}
// @@@ Package initialization
// Caution: This code is still clumsy, because toolstash -cmp is
// particularly sensitive to it.
type typeDeclGen struct {
*syntax.TypeDecl
gen int
// Implicit type parameters in scope at this type declaration.
implicits []*types2.TypeName
}
type fileImports struct {
importedEmbed, importedUnsafe bool
}
type declCollector struct {
pw *pkgWriter
typegen *int
file *fileImports
withinFunc bool
implicits []*types2.TypeName
}
func (c *declCollector) withTParams(obj types2.Object) *declCollector {
tparams := objTypeParams(obj)
n := tparams.Len()
if n == 0 {
return c
}
copy := *c
copy.implicits = copy.implicits[:len(copy.implicits):len(copy.implicits)]
for i := 0; i < n; i++ {
copy.implicits = append(copy.implicits, tparams.At(i).Obj())
}
return ©
}
func (c *declCollector) Visit(n syntax.Node) syntax.Visitor {
pw := c.pw
switch n := n.(type) {
case *syntax.File:
pw.checkPragmas(n.Pragma, ir.GoBuildPragma, false)
case *syntax.ImportDecl:
pw.checkPragmas(n.Pragma, 0, false)
switch pkgNameOf(pw.info, n).Imported().Path() {
case "embed":
c.file.importedEmbed = true
case "unsafe":
c.file.importedUnsafe = true
}
case *syntax.ConstDecl:
pw.checkPragmas(n.Pragma, 0, false)
case *syntax.FuncDecl:
pw.checkPragmas(n.Pragma, funcPragmas, false)
obj := pw.info.Defs[n.Name].(*types2.Func)
pw.funDecls[obj] = n
return c.withTParams(obj)
case *syntax.TypeDecl:
obj := pw.info.Defs[n.Name].(*types2.TypeName)
d := typeDeclGen{TypeDecl: n, implicits: c.implicits}
if n.Alias {
pw.checkPragmas(n.Pragma, 0, false)
} else {
pw.checkPragmas(n.Pragma, typePragmas, false)
// Assign a unique ID to function-scoped defined types.
if c.withinFunc {
*c.typegen++
d.gen = *c.typegen
}
}
pw.typDecls[obj] = d
// TODO(mdempsky): Omit? Not strictly necessary; only matters for
// type declarations within function literals within parameterized
// type declarations, but types2 the function literals will be
// constant folded away.
return c.withTParams(obj)
case *syntax.VarDecl:
pw.checkPragmas(n.Pragma, 0, true)
if p, ok := n.Pragma.(*pragmas); ok && len(p.Embeds) > 0 {
if err := checkEmbed(n, c.file.importedEmbed, c.withinFunc); err != nil {
pw.errorf(p.Embeds[0].Pos, "%s", err)
}
}
case *syntax.BlockStmt:
if !c.withinFunc {
copy := *c
copy.withinFunc = true
return ©
}
}
return c
}
func (pw *pkgWriter) collectDecls(noders []*noder) {
var typegen int
for _, p := range noders {
var file fileImports
syntax.Walk(p.file, &declCollector{
pw: pw,
typegen: &typegen,
file: &file,
})
pw.cgoPragmas = append(pw.cgoPragmas, p.pragcgobuf...)
for _, l := range p.linknames {
if !file.importedUnsafe {
pw.errorf(l.pos, "//go:linkname only allowed in Go files that import \"unsafe\"")
continue
}
switch obj := pw.curpkg.Scope().Lookup(l.local).(type) {
case *types2.Func, *types2.Var:
if _, ok := pw.linknames[obj]; !ok {
pw.linknames[obj] = l.remote
} else {
pw.errorf(l.pos, "duplicate //go:linkname for %s", l.local)
}
default:
// TODO(mdempsky): Enable after #42938 is fixed.
if false {
pw.errorf(l.pos, "//go:linkname must refer to declared function or variable")
}
}
}
}
}
func (pw *pkgWriter) checkPragmas(p syntax.Pragma, allowed ir.PragmaFlag, embedOK bool) {
if p == nil {
return
}
pragma := p.(*pragmas)
for _, pos := range pragma.Pos {
if pos.Flag&^allowed != 0 {
pw.errorf(pos.Pos, "misplaced compiler directive")
}
}
if !embedOK {
for _, e := range pragma.Embeds {
pw.errorf(e.Pos, "misplaced go:embed directive")
}
}
}
func (w *writer) pkgInit(noders []*noder) {
w.Len(len(w.p.cgoPragmas))
for _, cgoPragma := range w.p.cgoPragmas {
w.Strings(cgoPragma)
}
w.Sync(pkgbits.SyncDecls)
for _, p := range noders {
for _, decl := range p.file.DeclList {
w.pkgDecl(decl)
}
}
w.Code(declEnd)
w.Sync(pkgbits.SyncEOF)
}
func (w *writer) pkgDecl(decl syntax.Decl) {
switch decl := decl.(type) {
default:
w.p.unexpected("declaration", decl)
case *syntax.ImportDecl:
case *syntax.ConstDecl:
w.Code(declOther)
w.pkgObjs(decl.NameList...)
case *syntax.FuncDecl:
if decl.Name.Value == "_" {
break // skip blank functions
}
obj := w.p.info.Defs[decl.Name].(*types2.Func)
sig := obj.Type().(*types2.Signature)
if sig.RecvTypeParams() != nil || sig.TypeParams() != nil {
break // skip generic functions
}
if recv := sig.Recv(); recv != nil {
w.Code(declMethod)
w.typ(recvBase(recv))
w.selector(obj)
break
}
w.Code(declFunc)
w.pkgObjs(decl.Name)
case *syntax.TypeDecl:
if len(decl.TParamList) != 0 {
break // skip generic type decls
}
if decl.Name.Value == "_" {
break // skip blank type decls
}
name := w.p.info.Defs[decl.Name].(*types2.TypeName)
// Skip type declarations for interfaces that are only usable as
// type parameter bounds.
if iface, ok := name.Type().Underlying().(*types2.Interface); ok && !iface.IsMethodSet() {
break
}
w.Code(declOther)
w.pkgObjs(decl.Name)
case *syntax.VarDecl:
w.Code(declVar)
w.pos(decl)
w.pkgObjs(decl.NameList...)
w.exprList(decl.Values)
var embeds []pragmaEmbed
if p, ok := decl.Pragma.(*pragmas); ok {
embeds = p.Embeds
}
w.Len(len(embeds))
for _, embed := range embeds {
w.pos(embed.Pos)
w.Strings(embed.Patterns)
}
}
}
func (w *writer) pkgObjs(names ...*syntax.Name) {
w.Sync(pkgbits.SyncDeclNames)
w.Len(len(names))
for _, name := range names {
obj, ok := w.p.info.Defs[name]
assert(ok)
w.Sync(pkgbits.SyncDeclName)
w.obj(obj, nil)
}
}
// @@@ Helpers
// isDefinedType reports whether obj is a defined type.
func isDefinedType(obj types2.Object) bool {
if obj, ok := obj.(*types2.TypeName); ok {
return !obj.IsAlias()
}
return false
}
// isGlobal reports whether obj was declared at package scope.
//
// Caveat: blank objects are not declared.
func isGlobal(obj types2.Object) bool {
return obj.Parent() == obj.Pkg().Scope()
}
// lookupObj returns the object that expr refers to, if any. If expr
// is an explicit instantiation of a generic object, then the instance
// object is returned as well.
func lookupObj(info *types2.Info, expr syntax.Expr) (obj types2.Object, inst types2.Instance) {
if index, ok := expr.(*syntax.IndexExpr); ok {
args := unpackListExpr(index.Index)
if len(args) == 1 {
tv, ok := info.Types[args[0]]
assert(ok)
if tv.IsValue() {
return // normal index expression
}
}
expr = index.X
}
// Strip package qualifier, if present.
if sel, ok := expr.(*syntax.SelectorExpr); ok {
if !isPkgQual(info, sel) {
return // normal selector expression
}
expr = sel.Sel
}
if name, ok := expr.(*syntax.Name); ok {
obj = info.Uses[name]
inst = info.Instances[name]
}
return
}
// isPkgQual reports whether the given selector expression is a
// package-qualified identifier.
func isPkgQual(info *types2.Info, sel *syntax.SelectorExpr) bool {
if name, ok := sel.X.(*syntax.Name); ok {
_, isPkgName := info.Uses[name].(*types2.PkgName)
return isPkgName
}
return false
}
// recvBase returns the base type for the given receiver parameter.
func recvBase(recv *types2.Var) *types2.Named {
typ := recv.Type()
if ptr, ok := typ.(*types2.Pointer); ok {
typ = ptr.Elem()
}
return typ.(*types2.Named)
}
// namesAsExpr returns a list of names as a syntax.Expr.
func namesAsExpr(names []*syntax.Name) syntax.Expr {
if len(names) == 1 {
return names[0]
}
exprs := make([]syntax.Expr, len(names))
for i, name := range names {
exprs[i] = name
}
return &syntax.ListExpr{ElemList: exprs}
}
// fieldIndex returns the index of the struct field named by key.
func fieldIndex(info *types2.Info, str *types2.Struct, key *syntax.Name) int {
field := info.Uses[key].(*types2.Var)
for i := 0; i < str.NumFields(); i++ {
if str.Field(i) == field {
return i
}
}
panic(fmt.Sprintf("%s: %v is not a field of %v", key.Pos(), field, str))
}
// objTypeParams returns the type parameters on the given object.
func objTypeParams(obj types2.Object) *types2.TypeParamList {
switch obj := obj.(type) {
case *types2.Func:
sig := obj.Type().(*types2.Signature)
if sig.Recv() != nil {
return sig.RecvTypeParams()
}
return sig.TypeParams()
case *types2.TypeName:
if !obj.IsAlias() {
return obj.Type().(*types2.Named).TypeParams()
}
}
return nil
}
func asPragmaFlag(p syntax.Pragma) ir.PragmaFlag {
if p == nil {
return 0
}
return p.(*pragmas).Flag
}
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