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-rw-r--r--src/cmd/compile/internal/reflectdata/reflect.go2120
1 files changed, 2120 insertions, 0 deletions
diff --git a/src/cmd/compile/internal/reflectdata/reflect.go b/src/cmd/compile/internal/reflectdata/reflect.go
new file mode 100644
index 0000000..4ee9830
--- /dev/null
+++ b/src/cmd/compile/internal/reflectdata/reflect.go
@@ -0,0 +1,2120 @@
+// Copyright 2009 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 reflectdata
+
+import (
+ "encoding/binary"
+ "fmt"
+ "os"
+ "sort"
+ "strings"
+ "sync"
+
+ "cmd/compile/internal/base"
+ "cmd/compile/internal/bitvec"
+ "cmd/compile/internal/escape"
+ "cmd/compile/internal/inline"
+ "cmd/compile/internal/ir"
+ "cmd/compile/internal/objw"
+ "cmd/compile/internal/staticdata"
+ "cmd/compile/internal/typebits"
+ "cmd/compile/internal/typecheck"
+ "cmd/compile/internal/types"
+ "cmd/internal/gcprog"
+ "cmd/internal/obj"
+ "cmd/internal/objabi"
+ "cmd/internal/src"
+)
+
+type ptabEntry struct {
+ s *types.Sym
+ t *types.Type
+}
+
+func CountPTabs() int {
+ return len(ptabs)
+}
+
+// runtime interface and reflection data structures
+var (
+ // protects signatset and signatslice
+ signatmu sync.Mutex
+ // Tracking which types need runtime type descriptor
+ signatset = make(map[*types.Type]struct{})
+ // Queue of types wait to be generated runtime type descriptor
+ signatslice []typeAndStr
+
+ gcsymmu sync.Mutex // protects gcsymset and gcsymslice
+ gcsymset = make(map[*types.Type]struct{})
+
+ ptabs []*ir.Name
+)
+
+type typeSig struct {
+ name *types.Sym
+ isym *obj.LSym
+ tsym *obj.LSym
+ type_ *types.Type
+ mtype *types.Type
+}
+
+// Builds a type representing a Bucket structure for
+// the given map type. This type is not visible to users -
+// we include only enough information to generate a correct GC
+// program for it.
+// Make sure this stays in sync with runtime/map.go.
+const (
+ BUCKETSIZE = 8
+ MAXKEYSIZE = 128
+ MAXELEMSIZE = 128
+)
+
+func structfieldSize() int { return 3 * types.PtrSize } // Sizeof(runtime.structfield{})
+func imethodSize() int { return 4 + 4 } // Sizeof(runtime.imethod{})
+func commonSize() int { return 4*types.PtrSize + 8 + 8 } // Sizeof(runtime._type{})
+
+func uncommonSize(t *types.Type) int { // Sizeof(runtime.uncommontype{})
+ if t.Sym() == nil && len(methods(t)) == 0 {
+ return 0
+ }
+ return 4 + 2 + 2 + 4 + 4
+}
+
+func makefield(name string, t *types.Type) *types.Field {
+ sym := (*types.Pkg)(nil).Lookup(name)
+ return types.NewField(src.NoXPos, sym, t)
+}
+
+// MapBucketType makes the map bucket type given the type of the map.
+func MapBucketType(t *types.Type) *types.Type {
+ if t.MapType().Bucket != nil {
+ return t.MapType().Bucket
+ }
+
+ keytype := t.Key()
+ elemtype := t.Elem()
+ types.CalcSize(keytype)
+ types.CalcSize(elemtype)
+ if keytype.Size() > MAXKEYSIZE {
+ keytype = types.NewPtr(keytype)
+ }
+ if elemtype.Size() > MAXELEMSIZE {
+ elemtype = types.NewPtr(elemtype)
+ }
+
+ field := make([]*types.Field, 0, 5)
+
+ // The first field is: uint8 topbits[BUCKETSIZE].
+ arr := types.NewArray(types.Types[types.TUINT8], BUCKETSIZE)
+ field = append(field, makefield("topbits", arr))
+
+ arr = types.NewArray(keytype, BUCKETSIZE)
+ arr.SetNoalg(true)
+ keys := makefield("keys", arr)
+ field = append(field, keys)
+
+ arr = types.NewArray(elemtype, BUCKETSIZE)
+ arr.SetNoalg(true)
+ elems := makefield("elems", arr)
+ field = append(field, elems)
+
+ // If keys and elems have no pointers, the map implementation
+ // can keep a list of overflow pointers on the side so that
+ // buckets can be marked as having no pointers.
+ // Arrange for the bucket to have no pointers by changing
+ // the type of the overflow field to uintptr in this case.
+ // See comment on hmap.overflow in runtime/map.go.
+ otyp := types.Types[types.TUNSAFEPTR]
+ if !elemtype.HasPointers() && !keytype.HasPointers() {
+ otyp = types.Types[types.TUINTPTR]
+ }
+ overflow := makefield("overflow", otyp)
+ field = append(field, overflow)
+
+ // link up fields
+ bucket := types.NewStruct(types.NoPkg, field[:])
+ bucket.SetNoalg(true)
+ types.CalcSize(bucket)
+
+ // Check invariants that map code depends on.
+ if !types.IsComparable(t.Key()) {
+ base.Fatalf("unsupported map key type for %v", t)
+ }
+ if BUCKETSIZE < 8 {
+ base.Fatalf("bucket size too small for proper alignment")
+ }
+ if uint8(keytype.Alignment()) > BUCKETSIZE {
+ base.Fatalf("key align too big for %v", t)
+ }
+ if uint8(elemtype.Alignment()) > BUCKETSIZE {
+ base.Fatalf("elem align too big for %v", t)
+ }
+ if keytype.Size() > MAXKEYSIZE {
+ base.Fatalf("key size to large for %v", t)
+ }
+ if elemtype.Size() > MAXELEMSIZE {
+ base.Fatalf("elem size to large for %v", t)
+ }
+ if t.Key().Size() > MAXKEYSIZE && !keytype.IsPtr() {
+ base.Fatalf("key indirect incorrect for %v", t)
+ }
+ if t.Elem().Size() > MAXELEMSIZE && !elemtype.IsPtr() {
+ base.Fatalf("elem indirect incorrect for %v", t)
+ }
+ if keytype.Size()%keytype.Alignment() != 0 {
+ base.Fatalf("key size not a multiple of key align for %v", t)
+ }
+ if elemtype.Size()%elemtype.Alignment() != 0 {
+ base.Fatalf("elem size not a multiple of elem align for %v", t)
+ }
+ if uint8(bucket.Alignment())%uint8(keytype.Alignment()) != 0 {
+ base.Fatalf("bucket align not multiple of key align %v", t)
+ }
+ if uint8(bucket.Alignment())%uint8(elemtype.Alignment()) != 0 {
+ base.Fatalf("bucket align not multiple of elem align %v", t)
+ }
+ if keys.Offset%keytype.Alignment() != 0 {
+ base.Fatalf("bad alignment of keys in bmap for %v", t)
+ }
+ if elems.Offset%elemtype.Alignment() != 0 {
+ base.Fatalf("bad alignment of elems in bmap for %v", t)
+ }
+
+ // Double-check that overflow field is final memory in struct,
+ // with no padding at end.
+ if overflow.Offset != bucket.Size()-int64(types.PtrSize) {
+ base.Fatalf("bad offset of overflow in bmap for %v", t)
+ }
+
+ t.MapType().Bucket = bucket
+
+ bucket.StructType().Map = t
+ return bucket
+}
+
+// MapType builds a type representing a Hmap structure for the given map type.
+// Make sure this stays in sync with runtime/map.go.
+func MapType(t *types.Type) *types.Type {
+ if t.MapType().Hmap != nil {
+ return t.MapType().Hmap
+ }
+
+ bmap := MapBucketType(t)
+
+ // build a struct:
+ // type hmap struct {
+ // count int
+ // flags uint8
+ // B uint8
+ // noverflow uint16
+ // hash0 uint32
+ // buckets *bmap
+ // oldbuckets *bmap
+ // nevacuate uintptr
+ // extra unsafe.Pointer // *mapextra
+ // }
+ // must match runtime/map.go:hmap.
+ fields := []*types.Field{
+ makefield("count", types.Types[types.TINT]),
+ makefield("flags", types.Types[types.TUINT8]),
+ makefield("B", types.Types[types.TUINT8]),
+ makefield("noverflow", types.Types[types.TUINT16]),
+ makefield("hash0", types.Types[types.TUINT32]), // Used in walk.go for OMAKEMAP.
+ makefield("buckets", types.NewPtr(bmap)), // Used in walk.go for OMAKEMAP.
+ makefield("oldbuckets", types.NewPtr(bmap)),
+ makefield("nevacuate", types.Types[types.TUINTPTR]),
+ makefield("extra", types.Types[types.TUNSAFEPTR]),
+ }
+
+ hmap := types.NewStruct(types.NoPkg, fields)
+ hmap.SetNoalg(true)
+ types.CalcSize(hmap)
+
+ // The size of hmap should be 48 bytes on 64 bit
+ // and 28 bytes on 32 bit platforms.
+ if size := int64(8 + 5*types.PtrSize); hmap.Size() != size {
+ base.Fatalf("hmap size not correct: got %d, want %d", hmap.Size(), size)
+ }
+
+ t.MapType().Hmap = hmap
+ hmap.StructType().Map = t
+ return hmap
+}
+
+// MapIterType builds a type representing an Hiter structure for the given map type.
+// Make sure this stays in sync with runtime/map.go.
+func MapIterType(t *types.Type) *types.Type {
+ if t.MapType().Hiter != nil {
+ return t.MapType().Hiter
+ }
+
+ hmap := MapType(t)
+ bmap := MapBucketType(t)
+
+ // build a struct:
+ // type hiter struct {
+ // key *Key
+ // elem *Elem
+ // t unsafe.Pointer // *MapType
+ // h *hmap
+ // buckets *bmap
+ // bptr *bmap
+ // overflow unsafe.Pointer // *[]*bmap
+ // oldoverflow unsafe.Pointer // *[]*bmap
+ // startBucket uintptr
+ // offset uint8
+ // wrapped bool
+ // B uint8
+ // i uint8
+ // bucket uintptr
+ // checkBucket uintptr
+ // }
+ // must match runtime/map.go:hiter.
+ fields := []*types.Field{
+ makefield("key", types.NewPtr(t.Key())), // Used in range.go for TMAP.
+ makefield("elem", types.NewPtr(t.Elem())), // Used in range.go for TMAP.
+ makefield("t", types.Types[types.TUNSAFEPTR]),
+ makefield("h", types.NewPtr(hmap)),
+ makefield("buckets", types.NewPtr(bmap)),
+ makefield("bptr", types.NewPtr(bmap)),
+ makefield("overflow", types.Types[types.TUNSAFEPTR]),
+ makefield("oldoverflow", types.Types[types.TUNSAFEPTR]),
+ makefield("startBucket", types.Types[types.TUINTPTR]),
+ makefield("offset", types.Types[types.TUINT8]),
+ makefield("wrapped", types.Types[types.TBOOL]),
+ makefield("B", types.Types[types.TUINT8]),
+ makefield("i", types.Types[types.TUINT8]),
+ makefield("bucket", types.Types[types.TUINTPTR]),
+ makefield("checkBucket", types.Types[types.TUINTPTR]),
+ }
+
+ // build iterator struct holding the above fields
+ hiter := types.NewStruct(types.NoPkg, fields)
+ hiter.SetNoalg(true)
+ types.CalcSize(hiter)
+ if hiter.Size() != int64(12*types.PtrSize) {
+ base.Fatalf("hash_iter size not correct %d %d", hiter.Size(), 12*types.PtrSize)
+ }
+ t.MapType().Hiter = hiter
+ hiter.StructType().Map = t
+ return hiter
+}
+
+// methods returns the methods of the non-interface type t, sorted by name.
+// Generates stub functions as needed.
+func methods(t *types.Type) []*typeSig {
+ if t.HasShape() {
+ // Shape types have no methods.
+ return nil
+ }
+ // method type
+ mt := types.ReceiverBaseType(t)
+
+ if mt == nil {
+ return nil
+ }
+ typecheck.CalcMethods(mt)
+
+ // make list of methods for t,
+ // generating code if necessary.
+ var ms []*typeSig
+ for _, f := range mt.AllMethods().Slice() {
+ if f.Sym == nil {
+ base.Fatalf("method with no sym on %v", mt)
+ }
+ if !f.IsMethod() {
+ base.Fatalf("non-method on %v method %v %v", mt, f.Sym, f)
+ }
+ if f.Type.Recv() == nil {
+ base.Fatalf("receiver with no type on %v method %v %v", mt, f.Sym, f)
+ }
+ if f.Nointerface() && !t.IsFullyInstantiated() {
+ // Skip creating method wrappers if f is nointerface. But, if
+ // t is an instantiated type, we still have to call
+ // methodWrapper, because methodWrapper generates the actual
+ // generic method on the type as well.
+ continue
+ }
+
+ // get receiver type for this particular method.
+ // if pointer receiver but non-pointer t and
+ // this is not an embedded pointer inside a struct,
+ // method does not apply.
+ if !types.IsMethodApplicable(t, f) {
+ continue
+ }
+
+ sig := &typeSig{
+ name: f.Sym,
+ isym: methodWrapper(t, f, true),
+ tsym: methodWrapper(t, f, false),
+ type_: typecheck.NewMethodType(f.Type, t),
+ mtype: typecheck.NewMethodType(f.Type, nil),
+ }
+ if f.Nointerface() {
+ // In the case of a nointerface method on an instantiated
+ // type, don't actually apppend the typeSig.
+ continue
+ }
+ ms = append(ms, sig)
+ }
+
+ return ms
+}
+
+// imethods returns the methods of the interface type t, sorted by name.
+func imethods(t *types.Type) []*typeSig {
+ var methods []*typeSig
+ for _, f := range t.AllMethods().Slice() {
+ if f.Type.Kind() != types.TFUNC || f.Sym == nil {
+ continue
+ }
+ if f.Sym.IsBlank() {
+ base.Fatalf("unexpected blank symbol in interface method set")
+ }
+ if n := len(methods); n > 0 {
+ last := methods[n-1]
+ if !last.name.Less(f.Sym) {
+ base.Fatalf("sigcmp vs sortinter %v %v", last.name, f.Sym)
+ }
+ }
+
+ sig := &typeSig{
+ name: f.Sym,
+ mtype: f.Type,
+ type_: typecheck.NewMethodType(f.Type, nil),
+ }
+ methods = append(methods, sig)
+
+ // NOTE(rsc): Perhaps an oversight that
+ // IfaceType.Method is not in the reflect data.
+ // Generate the method body, so that compiled
+ // code can refer to it.
+ methodWrapper(t, f, false)
+ }
+
+ return methods
+}
+
+func dimportpath(p *types.Pkg) {
+ if p.Pathsym != nil {
+ return
+ }
+
+ // If we are compiling the runtime package, there are two runtime packages around
+ // -- localpkg and Pkgs.Runtime. We don't want to produce import path symbols for
+ // both of them, so just produce one for localpkg.
+ if base.Ctxt.Pkgpath == "runtime" && p == ir.Pkgs.Runtime {
+ return
+ }
+
+ str := p.Path
+ if p == types.LocalPkg {
+ // Note: myimportpath != "", or else dgopkgpath won't call dimportpath.
+ str = base.Ctxt.Pkgpath
+ }
+
+ s := base.Ctxt.Lookup("type..importpath." + p.Prefix + ".")
+ ot := dnameData(s, 0, str, "", nil, false)
+ objw.Global(s, int32(ot), obj.DUPOK|obj.RODATA)
+ s.Set(obj.AttrContentAddressable, true)
+ p.Pathsym = s
+}
+
+func dgopkgpath(s *obj.LSym, ot int, pkg *types.Pkg) int {
+ if pkg == nil {
+ return objw.Uintptr(s, ot, 0)
+ }
+
+ if pkg == types.LocalPkg && base.Ctxt.Pkgpath == "" {
+ // If we don't know the full import path of the package being compiled
+ // (i.e. -p was not passed on the compiler command line), emit a reference to
+ // type..importpath.""., which the linker will rewrite using the correct import path.
+ // Every package that imports this one directly defines the symbol.
+ // See also https://groups.google.com/forum/#!topic/golang-dev/myb9s53HxGQ.
+ ns := base.Ctxt.Lookup(`type..importpath."".`)
+ return objw.SymPtr(s, ot, ns, 0)
+ }
+
+ dimportpath(pkg)
+ return objw.SymPtr(s, ot, pkg.Pathsym, 0)
+}
+
+// dgopkgpathOff writes an offset relocation in s at offset ot to the pkg path symbol.
+func dgopkgpathOff(s *obj.LSym, ot int, pkg *types.Pkg) int {
+ if pkg == nil {
+ return objw.Uint32(s, ot, 0)
+ }
+ if pkg == types.LocalPkg && base.Ctxt.Pkgpath == "" {
+ // If we don't know the full import path of the package being compiled
+ // (i.e. -p was not passed on the compiler command line), emit a reference to
+ // type..importpath.""., which the linker will rewrite using the correct import path.
+ // Every package that imports this one directly defines the symbol.
+ // See also https://groups.google.com/forum/#!topic/golang-dev/myb9s53HxGQ.
+ ns := base.Ctxt.Lookup(`type..importpath."".`)
+ return objw.SymPtrOff(s, ot, ns)
+ }
+
+ dimportpath(pkg)
+ return objw.SymPtrOff(s, ot, pkg.Pathsym)
+}
+
+// dnameField dumps a reflect.name for a struct field.
+func dnameField(lsym *obj.LSym, ot int, spkg *types.Pkg, ft *types.Field) int {
+ if !types.IsExported(ft.Sym.Name) && ft.Sym.Pkg != spkg {
+ base.Fatalf("package mismatch for %v", ft.Sym)
+ }
+ nsym := dname(ft.Sym.Name, ft.Note, nil, types.IsExported(ft.Sym.Name))
+ return objw.SymPtr(lsym, ot, nsym, 0)
+}
+
+// dnameData writes the contents of a reflect.name into s at offset ot.
+func dnameData(s *obj.LSym, ot int, name, tag string, pkg *types.Pkg, exported bool) int {
+ if len(name) >= 1<<29 {
+ base.Fatalf("name too long: %d %s...", len(name), name[:1024])
+ }
+ if len(tag) >= 1<<29 {
+ base.Fatalf("tag too long: %d %s...", len(tag), tag[:1024])
+ }
+ var nameLen [binary.MaxVarintLen64]byte
+ nameLenLen := binary.PutUvarint(nameLen[:], uint64(len(name)))
+ var tagLen [binary.MaxVarintLen64]byte
+ tagLenLen := binary.PutUvarint(tagLen[:], uint64(len(tag)))
+
+ // Encode name and tag. See reflect/type.go for details.
+ var bits byte
+ l := 1 + nameLenLen + len(name)
+ if exported {
+ bits |= 1 << 0
+ }
+ if len(tag) > 0 {
+ l += tagLenLen + len(tag)
+ bits |= 1 << 1
+ }
+ if pkg != nil {
+ bits |= 1 << 2
+ }
+ b := make([]byte, l)
+ b[0] = bits
+ copy(b[1:], nameLen[:nameLenLen])
+ copy(b[1+nameLenLen:], name)
+ if len(tag) > 0 {
+ tb := b[1+nameLenLen+len(name):]
+ copy(tb, tagLen[:tagLenLen])
+ copy(tb[tagLenLen:], tag)
+ }
+
+ ot = int(s.WriteBytes(base.Ctxt, int64(ot), b))
+
+ if pkg != nil {
+ ot = dgopkgpathOff(s, ot, pkg)
+ }
+
+ return ot
+}
+
+var dnameCount int
+
+// dname creates a reflect.name for a struct field or method.
+func dname(name, tag string, pkg *types.Pkg, exported bool) *obj.LSym {
+ // Write out data as "type.." to signal two things to the
+ // linker, first that when dynamically linking, the symbol
+ // should be moved to a relro section, and second that the
+ // contents should not be decoded as a type.
+ sname := "type..namedata."
+ if pkg == nil {
+ // In the common case, share data with other packages.
+ if name == "" {
+ if exported {
+ sname += "-noname-exported." + tag
+ } else {
+ sname += "-noname-unexported." + tag
+ }
+ } else {
+ if exported {
+ sname += name + "." + tag
+ } else {
+ sname += name + "-" + tag
+ }
+ }
+ } else {
+ sname = fmt.Sprintf(`%s"".%d`, sname, dnameCount)
+ dnameCount++
+ }
+ s := base.Ctxt.Lookup(sname)
+ if len(s.P) > 0 {
+ return s
+ }
+ ot := dnameData(s, 0, name, tag, pkg, exported)
+ objw.Global(s, int32(ot), obj.DUPOK|obj.RODATA)
+ s.Set(obj.AttrContentAddressable, true)
+ return s
+}
+
+// dextratype dumps the fields of a runtime.uncommontype.
+// dataAdd is the offset in bytes after the header where the
+// backing array of the []method field is written (by dextratypeData).
+func dextratype(lsym *obj.LSym, ot int, t *types.Type, dataAdd int) int {
+ m := methods(t)
+ if t.Sym() == nil && len(m) == 0 {
+ return ot
+ }
+ noff := int(types.Rnd(int64(ot), int64(types.PtrSize)))
+ if noff != ot {
+ base.Fatalf("unexpected alignment in dextratype for %v", t)
+ }
+
+ for _, a := range m {
+ writeType(a.type_)
+ }
+
+ ot = dgopkgpathOff(lsym, ot, typePkg(t))
+
+ dataAdd += uncommonSize(t)
+ mcount := len(m)
+ if mcount != int(uint16(mcount)) {
+ base.Fatalf("too many methods on %v: %d", t, mcount)
+ }
+ xcount := sort.Search(mcount, func(i int) bool { return !types.IsExported(m[i].name.Name) })
+ if dataAdd != int(uint32(dataAdd)) {
+ base.Fatalf("methods are too far away on %v: %d", t, dataAdd)
+ }
+
+ ot = objw.Uint16(lsym, ot, uint16(mcount))
+ ot = objw.Uint16(lsym, ot, uint16(xcount))
+ ot = objw.Uint32(lsym, ot, uint32(dataAdd))
+ ot = objw.Uint32(lsym, ot, 0)
+ return ot
+}
+
+func typePkg(t *types.Type) *types.Pkg {
+ tsym := t.Sym()
+ if tsym == nil {
+ switch t.Kind() {
+ case types.TARRAY, types.TSLICE, types.TPTR, types.TCHAN:
+ if t.Elem() != nil {
+ tsym = t.Elem().Sym()
+ }
+ }
+ }
+ if tsym != nil && tsym.Pkg != types.BuiltinPkg {
+ return tsym.Pkg
+ }
+ return nil
+}
+
+// dextratypeData dumps the backing array for the []method field of
+// runtime.uncommontype.
+func dextratypeData(lsym *obj.LSym, ot int, t *types.Type) int {
+ for _, a := range methods(t) {
+ // ../../../../runtime/type.go:/method
+ exported := types.IsExported(a.name.Name)
+ var pkg *types.Pkg
+ if !exported && a.name.Pkg != typePkg(t) {
+ pkg = a.name.Pkg
+ }
+ nsym := dname(a.name.Name, "", pkg, exported)
+
+ ot = objw.SymPtrOff(lsym, ot, nsym)
+ ot = dmethodptrOff(lsym, ot, writeType(a.mtype))
+ ot = dmethodptrOff(lsym, ot, a.isym)
+ ot = dmethodptrOff(lsym, ot, a.tsym)
+ }
+ return ot
+}
+
+func dmethodptrOff(s *obj.LSym, ot int, x *obj.LSym) int {
+ objw.Uint32(s, ot, 0)
+ r := obj.Addrel(s)
+ r.Off = int32(ot)
+ r.Siz = 4
+ r.Sym = x
+ r.Type = objabi.R_METHODOFF
+ return ot + 4
+}
+
+var kinds = []int{
+ types.TINT: objabi.KindInt,
+ types.TUINT: objabi.KindUint,
+ types.TINT8: objabi.KindInt8,
+ types.TUINT8: objabi.KindUint8,
+ types.TINT16: objabi.KindInt16,
+ types.TUINT16: objabi.KindUint16,
+ types.TINT32: objabi.KindInt32,
+ types.TUINT32: objabi.KindUint32,
+ types.TINT64: objabi.KindInt64,
+ types.TUINT64: objabi.KindUint64,
+ types.TUINTPTR: objabi.KindUintptr,
+ types.TFLOAT32: objabi.KindFloat32,
+ types.TFLOAT64: objabi.KindFloat64,
+ types.TBOOL: objabi.KindBool,
+ types.TSTRING: objabi.KindString,
+ types.TPTR: objabi.KindPtr,
+ types.TSTRUCT: objabi.KindStruct,
+ types.TINTER: objabi.KindInterface,
+ types.TCHAN: objabi.KindChan,
+ types.TMAP: objabi.KindMap,
+ types.TARRAY: objabi.KindArray,
+ types.TSLICE: objabi.KindSlice,
+ types.TFUNC: objabi.KindFunc,
+ types.TCOMPLEX64: objabi.KindComplex64,
+ types.TCOMPLEX128: objabi.KindComplex128,
+ types.TUNSAFEPTR: objabi.KindUnsafePointer,
+}
+
+// tflag is documented in reflect/type.go.
+//
+// tflag values must be kept in sync with copies in:
+// cmd/compile/internal/reflectdata/reflect.go
+// cmd/link/internal/ld/decodesym.go
+// reflect/type.go
+// runtime/type.go
+const (
+ tflagUncommon = 1 << 0
+ tflagExtraStar = 1 << 1
+ tflagNamed = 1 << 2
+ tflagRegularMemory = 1 << 3
+)
+
+var (
+ memhashvarlen *obj.LSym
+ memequalvarlen *obj.LSym
+)
+
+// dcommontype dumps the contents of a reflect.rtype (runtime._type).
+func dcommontype(lsym *obj.LSym, t *types.Type) int {
+ types.CalcSize(t)
+ eqfunc := geneq(t)
+
+ sptrWeak := true
+ var sptr *obj.LSym
+ if !t.IsPtr() || t.IsPtrElem() {
+ tptr := types.NewPtr(t)
+ if t.Sym() != nil || methods(tptr) != nil {
+ sptrWeak = false
+ }
+ sptr = writeType(tptr)
+ }
+
+ gcsym, useGCProg, ptrdata := dgcsym(t, true)
+ delete(gcsymset, t)
+
+ // ../../../../reflect/type.go:/^type.rtype
+ // actual type structure
+ // type rtype struct {
+ // size uintptr
+ // ptrdata uintptr
+ // hash uint32
+ // tflag tflag
+ // align uint8
+ // fieldAlign uint8
+ // kind uint8
+ // equal func(unsafe.Pointer, unsafe.Pointer) bool
+ // gcdata *byte
+ // str nameOff
+ // ptrToThis typeOff
+ // }
+ ot := 0
+ ot = objw.Uintptr(lsym, ot, uint64(t.Size()))
+ ot = objw.Uintptr(lsym, ot, uint64(ptrdata))
+ ot = objw.Uint32(lsym, ot, types.TypeHash(t))
+
+ var tflag uint8
+ if uncommonSize(t) != 0 {
+ tflag |= tflagUncommon
+ }
+ if t.Sym() != nil && t.Sym().Name != "" {
+ tflag |= tflagNamed
+ }
+ if isRegularMemory(t) {
+ tflag |= tflagRegularMemory
+ }
+
+ exported := false
+ p := t.NameString()
+ // If we're writing out type T,
+ // we are very likely to write out type *T as well.
+ // Use the string "*T"[1:] for "T", so that the two
+ // share storage. This is a cheap way to reduce the
+ // amount of space taken up by reflect strings.
+ if !strings.HasPrefix(p, "*") {
+ p = "*" + p
+ tflag |= tflagExtraStar
+ if t.Sym() != nil {
+ exported = types.IsExported(t.Sym().Name)
+ }
+ } else {
+ if t.Elem() != nil && t.Elem().Sym() != nil {
+ exported = types.IsExported(t.Elem().Sym().Name)
+ }
+ }
+
+ ot = objw.Uint8(lsym, ot, tflag)
+
+ // runtime (and common sense) expects alignment to be a power of two.
+ i := int(uint8(t.Alignment()))
+
+ if i == 0 {
+ i = 1
+ }
+ if i&(i-1) != 0 {
+ base.Fatalf("invalid alignment %d for %v", uint8(t.Alignment()), t)
+ }
+ ot = objw.Uint8(lsym, ot, uint8(t.Alignment())) // align
+ ot = objw.Uint8(lsym, ot, uint8(t.Alignment())) // fieldAlign
+
+ i = kinds[t.Kind()]
+ if types.IsDirectIface(t) {
+ i |= objabi.KindDirectIface
+ }
+ if useGCProg {
+ i |= objabi.KindGCProg
+ }
+ ot = objw.Uint8(lsym, ot, uint8(i)) // kind
+ if eqfunc != nil {
+ ot = objw.SymPtr(lsym, ot, eqfunc, 0) // equality function
+ } else {
+ ot = objw.Uintptr(lsym, ot, 0) // type we can't do == with
+ }
+ ot = objw.SymPtr(lsym, ot, gcsym, 0) // gcdata
+
+ nsym := dname(p, "", nil, exported)
+ ot = objw.SymPtrOff(lsym, ot, nsym) // str
+ // ptrToThis
+ if sptr == nil {
+ ot = objw.Uint32(lsym, ot, 0)
+ } else if sptrWeak {
+ ot = objw.SymPtrWeakOff(lsym, ot, sptr)
+ } else {
+ ot = objw.SymPtrOff(lsym, ot, sptr)
+ }
+
+ return ot
+}
+
+// TrackSym returns the symbol for tracking use of field/method f, assumed
+// to be a member of struct/interface type t.
+func TrackSym(t *types.Type, f *types.Field) *obj.LSym {
+ return base.PkgLinksym("go.track", t.LinkString()+"."+f.Sym.Name, obj.ABI0)
+}
+
+func TypeSymPrefix(prefix string, t *types.Type) *types.Sym {
+ p := prefix + "." + t.LinkString()
+ s := types.TypeSymLookup(p)
+
+ // This function is for looking up type-related generated functions
+ // (e.g. eq and hash). Make sure they are indeed generated.
+ signatmu.Lock()
+ NeedRuntimeType(t)
+ signatmu.Unlock()
+
+ //print("algsym: %s -> %+S\n", p, s);
+
+ return s
+}
+
+func TypeSym(t *types.Type) *types.Sym {
+ if t == nil || (t.IsPtr() && t.Elem() == nil) || t.IsUntyped() {
+ base.Fatalf("TypeSym %v", t)
+ }
+ if t.Kind() == types.TFUNC && t.Recv() != nil {
+ base.Fatalf("misuse of method type: %v", t)
+ }
+ s := types.TypeSym(t)
+ signatmu.Lock()
+ NeedRuntimeType(t)
+ signatmu.Unlock()
+ return s
+}
+
+func TypeLinksymPrefix(prefix string, t *types.Type) *obj.LSym {
+ return TypeSymPrefix(prefix, t).Linksym()
+}
+
+func TypeLinksymLookup(name string) *obj.LSym {
+ return types.TypeSymLookup(name).Linksym()
+}
+
+func TypeLinksym(t *types.Type) *obj.LSym {
+ return TypeSym(t).Linksym()
+}
+
+func TypePtr(t *types.Type) *ir.AddrExpr {
+ n := ir.NewLinksymExpr(base.Pos, TypeLinksym(t), types.Types[types.TUINT8])
+ return typecheck.Expr(typecheck.NodAddr(n)).(*ir.AddrExpr)
+}
+
+// ITabLsym returns the LSym representing the itab for concrete type typ implementing
+// interface iface. A dummy tab will be created in the unusual case where typ doesn't
+// implement iface. Normally, this wouldn't happen, because the typechecker would
+// have reported a compile-time error. This situation can only happen when the
+// destination type of a type assert or a type in a type switch is parameterized, so
+// it may sometimes, but not always, be a type that can't implement the specified
+// interface.
+func ITabLsym(typ, iface *types.Type) *obj.LSym {
+ s, existed := ir.Pkgs.Itab.LookupOK(typ.LinkString() + "," + iface.LinkString())
+ lsym := s.Linksym()
+
+ if !existed {
+ writeITab(lsym, typ, iface, true)
+ }
+ return lsym
+}
+
+// ITabAddr returns an expression representing a pointer to the itab
+// for concrete type typ implementing interface iface.
+func ITabAddr(typ, iface *types.Type) *ir.AddrExpr {
+ s, existed := ir.Pkgs.Itab.LookupOK(typ.LinkString() + "," + iface.LinkString())
+ lsym := s.Linksym()
+
+ if !existed {
+ writeITab(lsym, typ, iface, false)
+ }
+
+ n := ir.NewLinksymExpr(base.Pos, lsym, types.Types[types.TUINT8])
+ return typecheck.Expr(typecheck.NodAddr(n)).(*ir.AddrExpr)
+}
+
+// needkeyupdate reports whether map updates with t as a key
+// need the key to be updated.
+func needkeyupdate(t *types.Type) bool {
+ switch t.Kind() {
+ case types.TBOOL, types.TINT, types.TUINT, types.TINT8, types.TUINT8, types.TINT16, types.TUINT16, types.TINT32, types.TUINT32,
+ types.TINT64, types.TUINT64, types.TUINTPTR, types.TPTR, types.TUNSAFEPTR, types.TCHAN:
+ return false
+
+ case types.TFLOAT32, types.TFLOAT64, types.TCOMPLEX64, types.TCOMPLEX128, // floats and complex can be +0/-0
+ types.TINTER,
+ types.TSTRING: // strings might have smaller backing stores
+ return true
+
+ case types.TARRAY:
+ return needkeyupdate(t.Elem())
+
+ case types.TSTRUCT:
+ for _, t1 := range t.Fields().Slice() {
+ if needkeyupdate(t1.Type) {
+ return true
+ }
+ }
+ return false
+
+ default:
+ base.Fatalf("bad type for map key: %v", t)
+ return true
+ }
+}
+
+// hashMightPanic reports whether the hash of a map key of type t might panic.
+func hashMightPanic(t *types.Type) bool {
+ switch t.Kind() {
+ case types.TINTER:
+ return true
+
+ case types.TARRAY:
+ return hashMightPanic(t.Elem())
+
+ case types.TSTRUCT:
+ for _, t1 := range t.Fields().Slice() {
+ if hashMightPanic(t1.Type) {
+ return true
+ }
+ }
+ return false
+
+ default:
+ return false
+ }
+}
+
+// formalType replaces predeclared aliases with real types.
+// They've been separate internally to make error messages
+// better, but we have to merge them in the reflect tables.
+func formalType(t *types.Type) *types.Type {
+ switch t {
+ case types.AnyType, types.ByteType, types.RuneType:
+ return types.Types[t.Kind()]
+ }
+ return t
+}
+
+func writeType(t *types.Type) *obj.LSym {
+ t = formalType(t)
+ if t.IsUntyped() || t.HasTParam() {
+ base.Fatalf("writeType %v", t)
+ }
+
+ s := types.TypeSym(t)
+ lsym := s.Linksym()
+ if s.Siggen() {
+ return lsym
+ }
+ s.SetSiggen(true)
+
+ // special case (look for runtime below):
+ // when compiling package runtime,
+ // emit the type structures for int, float, etc.
+ tbase := t
+
+ if t.IsPtr() && t.Sym() == nil && t.Elem().Sym() != nil {
+ tbase = t.Elem()
+ }
+ if tbase.Kind() == types.TFORW {
+ base.Fatalf("unresolved defined type: %v", tbase)
+ }
+
+ if !NeedEmit(tbase) {
+ if i := typecheck.BaseTypeIndex(t); i >= 0 {
+ lsym.Pkg = tbase.Sym().Pkg.Prefix
+ lsym.SymIdx = int32(i)
+ lsym.Set(obj.AttrIndexed, true)
+ }
+
+ // TODO(mdempsky): Investigate whether this still happens.
+ // If we know we don't need to emit code for a type,
+ // we should have a link-symbol index for it.
+ // See also TODO in NeedEmit.
+ return lsym
+ }
+
+ ot := 0
+ switch t.Kind() {
+ default:
+ ot = dcommontype(lsym, t)
+ ot = dextratype(lsym, ot, t, 0)
+
+ case types.TARRAY:
+ // ../../../../runtime/type.go:/arrayType
+ s1 := writeType(t.Elem())
+ t2 := types.NewSlice(t.Elem())
+ s2 := writeType(t2)
+ ot = dcommontype(lsym, t)
+ ot = objw.SymPtr(lsym, ot, s1, 0)
+ ot = objw.SymPtr(lsym, ot, s2, 0)
+ ot = objw.Uintptr(lsym, ot, uint64(t.NumElem()))
+ ot = dextratype(lsym, ot, t, 0)
+
+ case types.TSLICE:
+ // ../../../../runtime/type.go:/sliceType
+ s1 := writeType(t.Elem())
+ ot = dcommontype(lsym, t)
+ ot = objw.SymPtr(lsym, ot, s1, 0)
+ ot = dextratype(lsym, ot, t, 0)
+
+ case types.TCHAN:
+ // ../../../../runtime/type.go:/chanType
+ s1 := writeType(t.Elem())
+ ot = dcommontype(lsym, t)
+ ot = objw.SymPtr(lsym, ot, s1, 0)
+ ot = objw.Uintptr(lsym, ot, uint64(t.ChanDir()))
+ ot = dextratype(lsym, ot, t, 0)
+
+ case types.TFUNC:
+ for _, t1 := range t.Recvs().Fields().Slice() {
+ writeType(t1.Type)
+ }
+ isddd := false
+ for _, t1 := range t.Params().Fields().Slice() {
+ isddd = t1.IsDDD()
+ writeType(t1.Type)
+ }
+ for _, t1 := range t.Results().Fields().Slice() {
+ writeType(t1.Type)
+ }
+
+ ot = dcommontype(lsym, t)
+ inCount := t.NumRecvs() + t.NumParams()
+ outCount := t.NumResults()
+ if isddd {
+ outCount |= 1 << 15
+ }
+ ot = objw.Uint16(lsym, ot, uint16(inCount))
+ ot = objw.Uint16(lsym, ot, uint16(outCount))
+ if types.PtrSize == 8 {
+ ot += 4 // align for *rtype
+ }
+
+ dataAdd := (inCount + t.NumResults()) * types.PtrSize
+ ot = dextratype(lsym, ot, t, dataAdd)
+
+ // Array of rtype pointers follows funcType.
+ for _, t1 := range t.Recvs().Fields().Slice() {
+ ot = objw.SymPtr(lsym, ot, writeType(t1.Type), 0)
+ }
+ for _, t1 := range t.Params().Fields().Slice() {
+ ot = objw.SymPtr(lsym, ot, writeType(t1.Type), 0)
+ }
+ for _, t1 := range t.Results().Fields().Slice() {
+ ot = objw.SymPtr(lsym, ot, writeType(t1.Type), 0)
+ }
+
+ case types.TINTER:
+ m := imethods(t)
+ n := len(m)
+ for _, a := range m {
+ writeType(a.type_)
+ }
+
+ // ../../../../runtime/type.go:/interfaceType
+ ot = dcommontype(lsym, t)
+
+ var tpkg *types.Pkg
+ if t.Sym() != nil && t != types.Types[t.Kind()] && t != types.ErrorType {
+ tpkg = t.Sym().Pkg
+ }
+ ot = dgopkgpath(lsym, ot, tpkg)
+
+ ot = objw.SymPtr(lsym, ot, lsym, ot+3*types.PtrSize+uncommonSize(t))
+ ot = objw.Uintptr(lsym, ot, uint64(n))
+ ot = objw.Uintptr(lsym, ot, uint64(n))
+ dataAdd := imethodSize() * n
+ ot = dextratype(lsym, ot, t, dataAdd)
+
+ for _, a := range m {
+ // ../../../../runtime/type.go:/imethod
+ exported := types.IsExported(a.name.Name)
+ var pkg *types.Pkg
+ if !exported && a.name.Pkg != tpkg {
+ pkg = a.name.Pkg
+ }
+ nsym := dname(a.name.Name, "", pkg, exported)
+
+ ot = objw.SymPtrOff(lsym, ot, nsym)
+ ot = objw.SymPtrOff(lsym, ot, writeType(a.type_))
+ }
+
+ // ../../../../runtime/type.go:/mapType
+ case types.TMAP:
+ s1 := writeType(t.Key())
+ s2 := writeType(t.Elem())
+ s3 := writeType(MapBucketType(t))
+ hasher := genhash(t.Key())
+
+ ot = dcommontype(lsym, t)
+ ot = objw.SymPtr(lsym, ot, s1, 0)
+ ot = objw.SymPtr(lsym, ot, s2, 0)
+ ot = objw.SymPtr(lsym, ot, s3, 0)
+ ot = objw.SymPtr(lsym, ot, hasher, 0)
+ var flags uint32
+ // Note: flags must match maptype accessors in ../../../../runtime/type.go
+ // and maptype builder in ../../../../reflect/type.go:MapOf.
+ if t.Key().Size() > MAXKEYSIZE {
+ ot = objw.Uint8(lsym, ot, uint8(types.PtrSize))
+ flags |= 1 // indirect key
+ } else {
+ ot = objw.Uint8(lsym, ot, uint8(t.Key().Size()))
+ }
+
+ if t.Elem().Size() > MAXELEMSIZE {
+ ot = objw.Uint8(lsym, ot, uint8(types.PtrSize))
+ flags |= 2 // indirect value
+ } else {
+ ot = objw.Uint8(lsym, ot, uint8(t.Elem().Size()))
+ }
+ ot = objw.Uint16(lsym, ot, uint16(MapBucketType(t).Size()))
+ if types.IsReflexive(t.Key()) {
+ flags |= 4 // reflexive key
+ }
+ if needkeyupdate(t.Key()) {
+ flags |= 8 // need key update
+ }
+ if hashMightPanic(t.Key()) {
+ flags |= 16 // hash might panic
+ }
+ ot = objw.Uint32(lsym, ot, flags)
+ ot = dextratype(lsym, ot, t, 0)
+ if u := t.Underlying(); u != t {
+ // If t is a named map type, also keep the underlying map
+ // type live in the binary. This is important to make sure that
+ // a named map and that same map cast to its underlying type via
+ // reflection, use the same hash function. See issue 37716.
+ r := obj.Addrel(lsym)
+ r.Sym = writeType(u)
+ r.Type = objabi.R_KEEP
+ }
+
+ case types.TPTR:
+ if t.Elem().Kind() == types.TANY {
+ // ../../../../runtime/type.go:/UnsafePointerType
+ ot = dcommontype(lsym, t)
+ ot = dextratype(lsym, ot, t, 0)
+
+ break
+ }
+
+ // ../../../../runtime/type.go:/ptrType
+ s1 := writeType(t.Elem())
+
+ ot = dcommontype(lsym, t)
+ ot = objw.SymPtr(lsym, ot, s1, 0)
+ ot = dextratype(lsym, ot, t, 0)
+
+ // ../../../../runtime/type.go:/structType
+ // for security, only the exported fields.
+ case types.TSTRUCT:
+ fields := t.Fields().Slice()
+ for _, t1 := range fields {
+ writeType(t1.Type)
+ }
+
+ // All non-exported struct field names within a struct
+ // type must originate from a single package. By
+ // identifying and recording that package within the
+ // struct type descriptor, we can omit that
+ // information from the field descriptors.
+ var spkg *types.Pkg
+ for _, f := range fields {
+ if !types.IsExported(f.Sym.Name) {
+ spkg = f.Sym.Pkg
+ break
+ }
+ }
+
+ ot = dcommontype(lsym, t)
+ ot = dgopkgpath(lsym, ot, spkg)
+ ot = objw.SymPtr(lsym, ot, lsym, ot+3*types.PtrSize+uncommonSize(t))
+ ot = objw.Uintptr(lsym, ot, uint64(len(fields)))
+ ot = objw.Uintptr(lsym, ot, uint64(len(fields)))
+
+ dataAdd := len(fields) * structfieldSize()
+ ot = dextratype(lsym, ot, t, dataAdd)
+
+ for _, f := range fields {
+ // ../../../../runtime/type.go:/structField
+ ot = dnameField(lsym, ot, spkg, f)
+ ot = objw.SymPtr(lsym, ot, writeType(f.Type), 0)
+ offsetAnon := uint64(f.Offset) << 1
+ if offsetAnon>>1 != uint64(f.Offset) {
+ base.Fatalf("%v: bad field offset for %s", t, f.Sym.Name)
+ }
+ if f.Embedded != 0 {
+ offsetAnon |= 1
+ }
+ ot = objw.Uintptr(lsym, ot, offsetAnon)
+ }
+ }
+
+ ot = dextratypeData(lsym, ot, t)
+ objw.Global(lsym, int32(ot), int16(obj.DUPOK|obj.RODATA))
+ // Note: DUPOK is required to ensure that we don't end up with more
+ // than one type descriptor for a given type.
+
+ // The linker will leave a table of all the typelinks for
+ // types in the binary, so the runtime can find them.
+ //
+ // When buildmode=shared, all types are in typelinks so the
+ // runtime can deduplicate type pointers.
+ keep := base.Ctxt.Flag_dynlink
+ if !keep && t.Sym() == nil {
+ // For an unnamed type, we only need the link if the type can
+ // be created at run time by reflect.PtrTo and similar
+ // functions. If the type exists in the program, those
+ // functions must return the existing type structure rather
+ // than creating a new one.
+ switch t.Kind() {
+ case types.TPTR, types.TARRAY, types.TCHAN, types.TFUNC, types.TMAP, types.TSLICE, types.TSTRUCT:
+ keep = true
+ }
+ }
+ // Do not put Noalg types in typelinks. See issue #22605.
+ if types.TypeHasNoAlg(t) {
+ keep = false
+ }
+ lsym.Set(obj.AttrMakeTypelink, keep)
+
+ return lsym
+}
+
+// InterfaceMethodOffset returns the offset of the i-th method in the interface
+// type descriptor, ityp.
+func InterfaceMethodOffset(ityp *types.Type, i int64) int64 {
+ // interface type descriptor layout is struct {
+ // _type // commonSize
+ // pkgpath // 1 word
+ // []imethod // 3 words (pointing to [...]imethod below)
+ // uncommontype // uncommonSize
+ // [...]imethod
+ // }
+ // The size of imethod is 8.
+ return int64(commonSize()+4*types.PtrSize+uncommonSize(ityp)) + i*8
+}
+
+// NeedRuntimeType ensures that a runtime type descriptor is emitted for t.
+func NeedRuntimeType(t *types.Type) {
+ if t.HasTParam() {
+ // Generic types don't really exist at run-time and have no runtime
+ // type descriptor. But we do write out shape types.
+ return
+ }
+ if _, ok := signatset[t]; !ok {
+ signatset[t] = struct{}{}
+ signatslice = append(signatslice, typeAndStr{t: t, short: types.TypeSymName(t), regular: t.String()})
+ }
+}
+
+func WriteRuntimeTypes() {
+ // Process signatslice. Use a loop, as writeType adds
+ // entries to signatslice while it is being processed.
+ for len(signatslice) > 0 {
+ signats := signatslice
+ // Sort for reproducible builds.
+ sort.Sort(typesByString(signats))
+ for _, ts := range signats {
+ t := ts.t
+ writeType(t)
+ if t.Sym() != nil {
+ writeType(types.NewPtr(t))
+ }
+ }
+ signatslice = signatslice[len(signats):]
+ }
+
+ // Emit GC data symbols.
+ gcsyms := make([]typeAndStr, 0, len(gcsymset))
+ for t := range gcsymset {
+ gcsyms = append(gcsyms, typeAndStr{t: t, short: types.TypeSymName(t), regular: t.String()})
+ }
+ sort.Sort(typesByString(gcsyms))
+ for _, ts := range gcsyms {
+ dgcsym(ts.t, true)
+ }
+}
+
+// writeITab writes the itab for concrete type typ implementing interface iface. If
+// allowNonImplement is true, allow the case where typ does not implement iface, and just
+// create a dummy itab with zeroed-out method entries.
+func writeITab(lsym *obj.LSym, typ, iface *types.Type, allowNonImplement bool) {
+ // TODO(mdempsky): Fix methodWrapper, geneq, and genhash (and maybe
+ // others) to stop clobbering these.
+ oldpos, oldfn := base.Pos, ir.CurFunc
+ defer func() { base.Pos, ir.CurFunc = oldpos, oldfn }()
+
+ if typ == nil || (typ.IsPtr() && typ.Elem() == nil) || typ.IsUntyped() || iface == nil || !iface.IsInterface() || iface.IsEmptyInterface() {
+ base.Fatalf("writeITab(%v, %v)", typ, iface)
+ }
+
+ sigs := iface.AllMethods().Slice()
+ entries := make([]*obj.LSym, 0, len(sigs))
+
+ // both sigs and methods are sorted by name,
+ // so we can find the intersection in a single pass
+ for _, m := range methods(typ) {
+ if m.name == sigs[0].Sym {
+ entries = append(entries, m.isym)
+ if m.isym == nil {
+ panic("NO ISYM")
+ }
+ sigs = sigs[1:]
+ if len(sigs) == 0 {
+ break
+ }
+ }
+ }
+ completeItab := len(sigs) == 0
+ if !allowNonImplement && !completeItab {
+ base.Fatalf("incomplete itab")
+ }
+
+ // dump empty itab symbol into i.sym
+ // type itab struct {
+ // inter *interfacetype
+ // _type *_type
+ // hash uint32 // copy of _type.hash. Used for type switches.
+ // _ [4]byte
+ // fun [1]uintptr // variable sized. fun[0]==0 means _type does not implement inter.
+ // }
+ o := objw.SymPtr(lsym, 0, writeType(iface), 0)
+ o = objw.SymPtr(lsym, o, writeType(typ), 0)
+ o = objw.Uint32(lsym, o, types.TypeHash(typ)) // copy of type hash
+ o += 4 // skip unused field
+ if !completeItab {
+ // If typ doesn't implement iface, make method entries be zero.
+ o = objw.Uintptr(lsym, o, 0)
+ entries = entries[:0]
+ }
+ for _, fn := range entries {
+ o = objw.SymPtrWeak(lsym, o, fn, 0) // method pointer for each method
+ }
+ // Nothing writes static itabs, so they are read only.
+ objw.Global(lsym, int32(o), int16(obj.DUPOK|obj.RODATA))
+ lsym.Set(obj.AttrContentAddressable, true)
+}
+
+func WriteTabs() {
+ // process ptabs
+ if types.LocalPkg.Name == "main" && len(ptabs) > 0 {
+ ot := 0
+ s := base.Ctxt.Lookup("go.plugin.tabs")
+ for _, p := range ptabs {
+ // Dump ptab symbol into go.pluginsym package.
+ //
+ // type ptab struct {
+ // name nameOff
+ // typ typeOff // pointer to symbol
+ // }
+ nsym := dname(p.Sym().Name, "", nil, true)
+ t := p.Type()
+ if p.Class != ir.PFUNC {
+ t = types.NewPtr(t)
+ }
+ tsym := writeType(t)
+ ot = objw.SymPtrOff(s, ot, nsym)
+ ot = objw.SymPtrOff(s, ot, tsym)
+ // Plugin exports symbols as interfaces. Mark their types
+ // as UsedInIface.
+ tsym.Set(obj.AttrUsedInIface, true)
+ }
+ objw.Global(s, int32(ot), int16(obj.RODATA))
+
+ ot = 0
+ s = base.Ctxt.Lookup("go.plugin.exports")
+ for _, p := range ptabs {
+ ot = objw.SymPtr(s, ot, p.Linksym(), 0)
+ }
+ objw.Global(s, int32(ot), int16(obj.RODATA))
+ }
+}
+
+func WriteImportStrings() {
+ // generate import strings for imported packages
+ for _, p := range types.ImportedPkgList() {
+ dimportpath(p)
+ }
+}
+
+func WriteBasicTypes() {
+ // do basic types if compiling package runtime.
+ // they have to be in at least one package,
+ // and runtime is always loaded implicitly,
+ // so this is as good as any.
+ // another possible choice would be package main,
+ // but using runtime means fewer copies in object files.
+ if base.Ctxt.Pkgpath == "runtime" {
+ for i := types.Kind(1); i <= types.TBOOL; i++ {
+ writeType(types.NewPtr(types.Types[i]))
+ }
+ writeType(types.NewPtr(types.Types[types.TSTRING]))
+ writeType(types.NewPtr(types.Types[types.TUNSAFEPTR]))
+ if base.Flag.G > 0 {
+ writeType(types.AnyType)
+ }
+
+ // emit type structs for error and func(error) string.
+ // The latter is the type of an auto-generated wrapper.
+ writeType(types.NewPtr(types.ErrorType))
+
+ writeType(types.NewSignature(types.NoPkg, nil, nil, []*types.Field{
+ types.NewField(base.Pos, nil, types.ErrorType),
+ }, []*types.Field{
+ types.NewField(base.Pos, nil, types.Types[types.TSTRING]),
+ }))
+
+ // add paths for runtime and main, which 6l imports implicitly.
+ dimportpath(ir.Pkgs.Runtime)
+
+ if base.Flag.Race {
+ dimportpath(types.NewPkg("runtime/race", ""))
+ }
+ if base.Flag.MSan {
+ dimportpath(types.NewPkg("runtime/msan", ""))
+ }
+ if base.Flag.ASan {
+ dimportpath(types.NewPkg("runtime/asan", ""))
+ }
+
+ dimportpath(types.NewPkg("main", ""))
+ }
+}
+
+type typeAndStr struct {
+ t *types.Type
+ short string // "short" here means TypeSymName
+ regular string
+}
+
+type typesByString []typeAndStr
+
+func (a typesByString) Len() int { return len(a) }
+func (a typesByString) Less(i, j int) bool {
+ if a[i].short != a[j].short {
+ return a[i].short < a[j].short
+ }
+ // When the only difference between the types is whether
+ // they refer to byte or uint8, such as **byte vs **uint8,
+ // the types' NameStrings can be identical.
+ // To preserve deterministic sort ordering, sort these by String().
+ //
+ // TODO(mdempsky): This all seems suspect. Using LinkString would
+ // avoid naming collisions, and there shouldn't be a reason to care
+ // about "byte" vs "uint8": they share the same runtime type
+ // descriptor anyway.
+ if a[i].regular != a[j].regular {
+ return a[i].regular < a[j].regular
+ }
+ // Identical anonymous interfaces defined in different locations
+ // will be equal for the above checks, but different in DWARF output.
+ // Sort by source position to ensure deterministic order.
+ // See issues 27013 and 30202.
+ if a[i].t.Kind() == types.TINTER && a[i].t.AllMethods().Len() > 0 {
+ return a[i].t.AllMethods().Index(0).Pos.Before(a[j].t.AllMethods().Index(0).Pos)
+ }
+ return false
+}
+func (a typesByString) Swap(i, j int) { a[i], a[j] = a[j], a[i] }
+
+// maxPtrmaskBytes is the maximum length of a GC ptrmask bitmap,
+// which holds 1-bit entries describing where pointers are in a given type.
+// Above this length, the GC information is recorded as a GC program,
+// which can express repetition compactly. In either form, the
+// information is used by the runtime to initialize the heap bitmap,
+// and for large types (like 128 or more words), they are roughly the
+// same speed. GC programs are never much larger and often more
+// compact. (If large arrays are involved, they can be arbitrarily
+// more compact.)
+//
+// The cutoff must be large enough that any allocation large enough to
+// use a GC program is large enough that it does not share heap bitmap
+// bytes with any other objects, allowing the GC program execution to
+// assume an aligned start and not use atomic operations. In the current
+// runtime, this means all malloc size classes larger than the cutoff must
+// be multiples of four words. On 32-bit systems that's 16 bytes, and
+// all size classes >= 16 bytes are 16-byte aligned, so no real constraint.
+// On 64-bit systems, that's 32 bytes, and 32-byte alignment is guaranteed
+// for size classes >= 256 bytes. On a 64-bit system, 256 bytes allocated
+// is 32 pointers, the bits for which fit in 4 bytes. So maxPtrmaskBytes
+// must be >= 4.
+//
+// We used to use 16 because the GC programs do have some constant overhead
+// to get started, and processing 128 pointers seems to be enough to
+// amortize that overhead well.
+//
+// To make sure that the runtime's chansend can call typeBitsBulkBarrier,
+// we raised the limit to 2048, so that even 32-bit systems are guaranteed to
+// use bitmaps for objects up to 64 kB in size.
+//
+// Also known to reflect/type.go.
+//
+const maxPtrmaskBytes = 2048
+
+// GCSym returns a data symbol containing GC information for type t, along
+// with a boolean reporting whether the UseGCProg bit should be set in the
+// type kind, and the ptrdata field to record in the reflect type information.
+// GCSym may be called in concurrent backend, so it does not emit the symbol
+// content.
+func GCSym(t *types.Type) (lsym *obj.LSym, useGCProg bool, ptrdata int64) {
+ // Record that we need to emit the GC symbol.
+ gcsymmu.Lock()
+ if _, ok := gcsymset[t]; !ok {
+ gcsymset[t] = struct{}{}
+ }
+ gcsymmu.Unlock()
+
+ return dgcsym(t, false)
+}
+
+// dgcsym returns a data symbol containing GC information for type t, along
+// with a boolean reporting whether the UseGCProg bit should be set in the
+// type kind, and the ptrdata field to record in the reflect type information.
+// When write is true, it writes the symbol data.
+func dgcsym(t *types.Type, write bool) (lsym *obj.LSym, useGCProg bool, ptrdata int64) {
+ ptrdata = types.PtrDataSize(t)
+ if ptrdata/int64(types.PtrSize) <= maxPtrmaskBytes*8 {
+ lsym = dgcptrmask(t, write)
+ return
+ }
+
+ useGCProg = true
+ lsym, ptrdata = dgcprog(t, write)
+ return
+}
+
+// dgcptrmask emits and returns the symbol containing a pointer mask for type t.
+func dgcptrmask(t *types.Type, write bool) *obj.LSym {
+ ptrmask := make([]byte, (types.PtrDataSize(t)/int64(types.PtrSize)+7)/8)
+ fillptrmask(t, ptrmask)
+ p := fmt.Sprintf("runtime.gcbits.%x", ptrmask)
+
+ lsym := base.Ctxt.Lookup(p)
+ if write && !lsym.OnList() {
+ for i, x := range ptrmask {
+ objw.Uint8(lsym, i, x)
+ }
+ objw.Global(lsym, int32(len(ptrmask)), obj.DUPOK|obj.RODATA|obj.LOCAL)
+ lsym.Set(obj.AttrContentAddressable, true)
+ }
+ return lsym
+}
+
+// fillptrmask fills in ptrmask with 1s corresponding to the
+// word offsets in t that hold pointers.
+// ptrmask is assumed to fit at least types.PtrDataSize(t)/PtrSize bits.
+func fillptrmask(t *types.Type, ptrmask []byte) {
+ for i := range ptrmask {
+ ptrmask[i] = 0
+ }
+ if !t.HasPointers() {
+ return
+ }
+
+ vec := bitvec.New(8 * int32(len(ptrmask)))
+ typebits.Set(t, 0, vec)
+
+ nptr := types.PtrDataSize(t) / int64(types.PtrSize)
+ for i := int64(0); i < nptr; i++ {
+ if vec.Get(int32(i)) {
+ ptrmask[i/8] |= 1 << (uint(i) % 8)
+ }
+ }
+}
+
+// dgcprog emits and returns the symbol containing a GC program for type t
+// along with the size of the data described by the program (in the range
+// [types.PtrDataSize(t), t.Width]).
+// In practice, the size is types.PtrDataSize(t) except for non-trivial arrays.
+// For non-trivial arrays, the program describes the full t.Width size.
+func dgcprog(t *types.Type, write bool) (*obj.LSym, int64) {
+ types.CalcSize(t)
+ if t.Size() == types.BADWIDTH {
+ base.Fatalf("dgcprog: %v badwidth", t)
+ }
+ lsym := TypeLinksymPrefix(".gcprog", t)
+ var p gcProg
+ p.init(lsym, write)
+ p.emit(t, 0)
+ offset := p.w.BitIndex() * int64(types.PtrSize)
+ p.end()
+ if ptrdata := types.PtrDataSize(t); offset < ptrdata || offset > t.Size() {
+ base.Fatalf("dgcprog: %v: offset=%d but ptrdata=%d size=%d", t, offset, ptrdata, t.Size())
+ }
+ return lsym, offset
+}
+
+type gcProg struct {
+ lsym *obj.LSym
+ symoff int
+ w gcprog.Writer
+ write bool
+}
+
+func (p *gcProg) init(lsym *obj.LSym, write bool) {
+ p.lsym = lsym
+ p.write = write && !lsym.OnList()
+ p.symoff = 4 // first 4 bytes hold program length
+ if !write {
+ p.w.Init(func(byte) {})
+ return
+ }
+ p.w.Init(p.writeByte)
+ if base.Debug.GCProg > 0 {
+ fmt.Fprintf(os.Stderr, "compile: start GCProg for %v\n", lsym)
+ p.w.Debug(os.Stderr)
+ }
+}
+
+func (p *gcProg) writeByte(x byte) {
+ p.symoff = objw.Uint8(p.lsym, p.symoff, x)
+}
+
+func (p *gcProg) end() {
+ p.w.End()
+ if !p.write {
+ return
+ }
+ objw.Uint32(p.lsym, 0, uint32(p.symoff-4))
+ objw.Global(p.lsym, int32(p.symoff), obj.DUPOK|obj.RODATA|obj.LOCAL)
+ p.lsym.Set(obj.AttrContentAddressable, true)
+ if base.Debug.GCProg > 0 {
+ fmt.Fprintf(os.Stderr, "compile: end GCProg for %v\n", p.lsym)
+ }
+}
+
+func (p *gcProg) emit(t *types.Type, offset int64) {
+ types.CalcSize(t)
+ if !t.HasPointers() {
+ return
+ }
+ if t.Size() == int64(types.PtrSize) {
+ p.w.Ptr(offset / int64(types.PtrSize))
+ return
+ }
+ switch t.Kind() {
+ default:
+ base.Fatalf("gcProg.emit: unexpected type %v", t)
+
+ case types.TSTRING:
+ p.w.Ptr(offset / int64(types.PtrSize))
+
+ case types.TINTER:
+ // Note: the first word isn't a pointer. See comment in typebits.Set
+ p.w.Ptr(offset/int64(types.PtrSize) + 1)
+
+ case types.TSLICE:
+ p.w.Ptr(offset / int64(types.PtrSize))
+
+ case types.TARRAY:
+ if t.NumElem() == 0 {
+ // should have been handled by haspointers check above
+ base.Fatalf("gcProg.emit: empty array")
+ }
+
+ // Flatten array-of-array-of-array to just a big array by multiplying counts.
+ count := t.NumElem()
+ elem := t.Elem()
+ for elem.IsArray() {
+ count *= elem.NumElem()
+ elem = elem.Elem()
+ }
+
+ if !p.w.ShouldRepeat(elem.Size()/int64(types.PtrSize), count) {
+ // Cheaper to just emit the bits.
+ for i := int64(0); i < count; i++ {
+ p.emit(elem, offset+i*elem.Size())
+ }
+ return
+ }
+ p.emit(elem, offset)
+ p.w.ZeroUntil((offset + elem.Size()) / int64(types.PtrSize))
+ p.w.Repeat(elem.Size()/int64(types.PtrSize), count-1)
+
+ case types.TSTRUCT:
+ for _, t1 := range t.Fields().Slice() {
+ p.emit(t1.Type, offset+t1.Offset)
+ }
+ }
+}
+
+// ZeroAddr returns the address of a symbol with at least
+// size bytes of zeros.
+func ZeroAddr(size int64) ir.Node {
+ if size >= 1<<31 {
+ base.Fatalf("map elem too big %d", size)
+ }
+ if ZeroSize < size {
+ ZeroSize = size
+ }
+ lsym := base.PkgLinksym("go.map", "zero", obj.ABI0)
+ x := ir.NewLinksymExpr(base.Pos, lsym, types.Types[types.TUINT8])
+ return typecheck.Expr(typecheck.NodAddr(x))
+}
+
+func CollectPTabs() {
+ if !base.Ctxt.Flag_dynlink || types.LocalPkg.Name != "main" {
+ return
+ }
+ for _, exportn := range typecheck.Target.Exports {
+ s := exportn.Sym()
+ nn := ir.AsNode(s.Def)
+ if nn == nil {
+ continue
+ }
+ if nn.Op() != ir.ONAME {
+ continue
+ }
+ n := nn.(*ir.Name)
+ if !types.IsExported(s.Name) {
+ continue
+ }
+ if s.Pkg.Name != "main" {
+ continue
+ }
+ ptabs = append(ptabs, n)
+ }
+}
+
+// NeedEmit reports whether typ is a type that we need to emit code
+// for (e.g., runtime type descriptors, method wrappers).
+func NeedEmit(typ *types.Type) bool {
+ // TODO(mdempsky): Export data should keep track of which anonymous
+ // and instantiated types were emitted, so at least downstream
+ // packages can skip re-emitting them.
+ //
+ // Perhaps we can just generalize the linker-symbol indexing to
+ // track the index of arbitrary types, not just defined types, and
+ // use its presence to detect this. The same idea would work for
+ // instantiated generic functions too.
+
+ switch sym := typ.Sym(); {
+ case sym == nil:
+ // Anonymous type; possibly never seen before or ever again.
+ // Need to emit to be safe (however, see TODO above).
+ return true
+
+ case sym.Pkg == types.LocalPkg:
+ // Local defined type; our responsibility.
+ return true
+
+ case base.Ctxt.Pkgpath == "runtime" && (sym.Pkg == types.BuiltinPkg || sym.Pkg == types.UnsafePkg):
+ // Package runtime is responsible for including code for builtin
+ // types (predeclared and package unsafe).
+ return true
+
+ case typ.IsFullyInstantiated():
+ // Instantiated type; possibly instantiated with unique type arguments.
+ // Need to emit to be safe (however, see TODO above).
+ return true
+
+ case typ.HasShape():
+ // Shape type; need to emit even though it lives in the .shape package.
+ // TODO: make sure the linker deduplicates them (see dupok in writeType above).
+ return true
+
+ default:
+ // Should have been emitted by an imported package.
+ return false
+ }
+}
+
+// Generate a wrapper function to convert from
+// a receiver of type T to a receiver of type U.
+// That is,
+//
+// func (t T) M() {
+// ...
+// }
+//
+// already exists; this function generates
+//
+// func (u U) M() {
+// u.M()
+// }
+//
+// where the types T and U are such that u.M() is valid
+// and calls the T.M method.
+// The resulting function is for use in method tables.
+//
+// rcvr - U
+// method - M func (t T)(), a TFIELD type struct
+//
+// Also wraps methods on instantiated generic types for use in itab entries.
+// For an instantiated generic type G[int], we generate wrappers like:
+// G[int] pointer shaped:
+// func (x G[int]) f(arg) {
+// .inst.G[int].f(dictionary, x, arg)
+// }
+// G[int] not pointer shaped:
+// func (x *G[int]) f(arg) {
+// .inst.G[int].f(dictionary, *x, arg)
+// }
+// These wrappers are always fully stenciled.
+func methodWrapper(rcvr *types.Type, method *types.Field, forItab bool) *obj.LSym {
+ orig := rcvr
+ if forItab && !types.IsDirectIface(rcvr) {
+ rcvr = rcvr.PtrTo()
+ }
+
+ generic := false
+ // We don't need a dictionary if we are reaching a method (possibly via an
+ // embedded field) which is an interface method.
+ if !types.IsInterfaceMethod(method.Type) {
+ rcvr1 := deref(rcvr)
+ if len(rcvr1.RParams()) > 0 {
+ // If rcvr has rparams, remember method as generic, which
+ // means we need to add a dictionary to the wrapper.
+ generic = true
+ if rcvr.HasShape() {
+ base.Fatalf("method on type instantiated with shapes, rcvr:%+v", rcvr)
+ }
+ }
+ }
+
+ newnam := ir.MethodSym(rcvr, method.Sym)
+ lsym := newnam.Linksym()
+ if newnam.Siggen() {
+ return lsym
+ }
+ newnam.SetSiggen(true)
+
+ // Except in quirks mode, unified IR creates its own wrappers.
+ if base.Debug.Unified != 0 && base.Debug.UnifiedQuirks == 0 {
+ return lsym
+ }
+
+ methodrcvr := method.Type.Recv().Type
+ // For generic methods, we need to generate the wrapper even if the receiver
+ // types are identical, because we want to add the dictionary.
+ if !generic && types.Identical(rcvr, methodrcvr) {
+ return lsym
+ }
+
+ if !NeedEmit(rcvr) || rcvr.IsPtr() && !NeedEmit(rcvr.Elem()) {
+ return lsym
+ }
+
+ base.Pos = base.AutogeneratedPos
+ typecheck.DeclContext = ir.PEXTERN
+
+ tfn := ir.NewFuncType(base.Pos,
+ ir.NewField(base.Pos, typecheck.Lookup(".this"), nil, rcvr),
+ typecheck.NewFuncParams(method.Type.Params(), true),
+ typecheck.NewFuncParams(method.Type.Results(), false))
+
+ // TODO(austin): SelectorExpr may have created one or more
+ // ir.Names for these already with a nil Func field. We should
+ // consolidate these and always attach a Func to the Name.
+ fn := typecheck.DeclFunc(newnam, tfn)
+ fn.SetDupok(true)
+
+ nthis := ir.AsNode(tfn.Type().Recv().Nname)
+
+ indirect := rcvr.IsPtr() && rcvr.Elem() == methodrcvr
+
+ // generate nil pointer check for better error
+ if indirect {
+ // generating wrapper from *T to T.
+ n := ir.NewIfStmt(base.Pos, nil, nil, nil)
+ n.Cond = ir.NewBinaryExpr(base.Pos, ir.OEQ, nthis, typecheck.NodNil())
+ call := ir.NewCallExpr(base.Pos, ir.OCALL, typecheck.LookupRuntime("panicwrap"), nil)
+ n.Body = []ir.Node{call}
+ fn.Body.Append(n)
+ }
+
+ dot := typecheck.AddImplicitDots(ir.NewSelectorExpr(base.Pos, ir.OXDOT, nthis, method.Sym))
+ // generate call
+ // It's not possible to use a tail call when dynamic linking on ppc64le. The
+ // bad scenario is when a local call is made to the wrapper: the wrapper will
+ // call the implementation, which might be in a different module and so set
+ // the TOC to the appropriate value for that module. But if it returns
+ // directly to the wrapper's caller, nothing will reset it to the correct
+ // value for that function.
+ var call *ir.CallExpr
+ if !base.Flag.Cfg.Instrumenting && rcvr.IsPtr() && methodrcvr.IsPtr() && method.Embedded != 0 && !types.IsInterfaceMethod(method.Type) && !(base.Ctxt.Arch.Name == "ppc64le" && base.Ctxt.Flag_dynlink) && !generic {
+ call = ir.NewCallExpr(base.Pos, ir.OCALL, dot, nil)
+ call.Args = ir.ParamNames(tfn.Type())
+ call.IsDDD = tfn.Type().IsVariadic()
+ fn.Body.Append(ir.NewTailCallStmt(base.Pos, call))
+ } else {
+ fn.SetWrapper(true) // ignore frame for panic+recover matching
+
+ if generic && dot.X != nthis {
+ // If there is embedding involved, then we should do the
+ // normal non-generic embedding wrapper below, which calls
+ // the wrapper for the real receiver type using dot as an
+ // argument. There is no need for generic processing (adding
+ // a dictionary) for this wrapper.
+ generic = false
+ }
+
+ if generic {
+ targs := deref(rcvr).RParams()
+ // The wrapper for an auto-generated pointer/non-pointer
+ // receiver method should share the same dictionary as the
+ // corresponding original (user-written) method.
+ baseOrig := orig
+ if baseOrig.IsPtr() && !methodrcvr.IsPtr() {
+ baseOrig = baseOrig.Elem()
+ } else if !baseOrig.IsPtr() && methodrcvr.IsPtr() {
+ baseOrig = types.NewPtr(baseOrig)
+ }
+ args := []ir.Node{getDictionary(ir.MethodSym(baseOrig, method.Sym), targs)}
+ if indirect {
+ args = append(args, ir.NewStarExpr(base.Pos, dot.X))
+ } else if methodrcvr.IsPtr() && methodrcvr.Elem() == dot.X.Type() {
+ // Case where method call is via a non-pointer
+ // embedded field with a pointer method.
+ args = append(args, typecheck.NodAddrAt(base.Pos, dot.X))
+ } else {
+ args = append(args, dot.X)
+ }
+ args = append(args, ir.ParamNames(tfn.Type())...)
+
+ // Target method uses shaped names.
+ targs2 := make([]*types.Type, len(targs))
+ origRParams := deref(orig).OrigType().RParams()
+ for i, t := range targs {
+ targs2[i] = typecheck.Shapify(t, i, origRParams[i])
+ }
+ targs = targs2
+
+ sym := typecheck.MakeFuncInstSym(ir.MethodSym(methodrcvr, method.Sym), targs, false, true)
+ if sym.Def == nil {
+ // Currently we make sure that we have all the
+ // instantiations we need by generating them all in
+ // ../noder/stencil.go:instantiateMethods
+ // Extra instantiations because of an inlined function
+ // should have been exported, and so available via
+ // Resolve.
+ in := typecheck.Resolve(ir.NewIdent(src.NoXPos, sym))
+ if in.Op() == ir.ONONAME {
+ base.Fatalf("instantiation %s not found", sym.Name)
+ }
+ sym = in.Sym()
+ }
+ target := ir.AsNode(sym.Def)
+ call = ir.NewCallExpr(base.Pos, ir.OCALL, target, args)
+ // Fill-in the generic method node that was not filled in
+ // in instantiateMethod.
+ method.Nname = fn.Nname
+ } else {
+ call = ir.NewCallExpr(base.Pos, ir.OCALL, dot, nil)
+ call.Args = ir.ParamNames(tfn.Type())
+ }
+ call.IsDDD = tfn.Type().IsVariadic()
+ if method.Type.NumResults() > 0 {
+ ret := ir.NewReturnStmt(base.Pos, nil)
+ ret.Results = []ir.Node{call}
+ fn.Body.Append(ret)
+ } else {
+ fn.Body.Append(call)
+ }
+ }
+
+ typecheck.FinishFuncBody()
+ if base.Debug.DclStack != 0 {
+ types.CheckDclstack()
+ }
+
+ typecheck.Func(fn)
+ ir.CurFunc = fn
+ typecheck.Stmts(fn.Body)
+
+ if AfterGlobalEscapeAnalysis {
+ // Inlining the method may reveal closures, which require walking all function bodies
+ // to decide whether to capture free variables by value or by ref. So we only do inline
+ // if the method do not contain any closures, otherwise, the escape analysis may make
+ // dead variables resurrected, and causing liveness analysis confused, see issue #53702.
+ var canInline bool
+ switch x := call.X.(type) {
+ case *ir.Name:
+ canInline = len(x.Func.Closures) == 0
+ case *ir.SelectorExpr:
+ if x.Op() == ir.OMETHEXPR {
+ canInline = x.FuncName().Func != nil && len(x.FuncName().Func.Closures) == 0
+ }
+ }
+ if canInline {
+ inline.InlineCalls(fn)
+ }
+ escape.Batch([]*ir.Func{fn}, false)
+ }
+
+ ir.CurFunc = nil
+ typecheck.Target.Decls = append(typecheck.Target.Decls, fn)
+
+ return lsym
+}
+
+// AfterGlobalEscapeAnalysis tracks whether package gc has already
+// performed the main, global escape analysis pass. If so,
+// methodWrapper takes responsibility for escape analyzing any
+// generated wrappers.
+var AfterGlobalEscapeAnalysis bool
+
+var ZeroSize int64
+
+// MarkTypeUsedInInterface marks that type t is converted to an interface.
+// This information is used in the linker in dead method elimination.
+func MarkTypeUsedInInterface(t *types.Type, from *obj.LSym) {
+ if t.HasShape() {
+ // Shape types shouldn't be put in interfaces, so we shouldn't ever get here.
+ base.Fatalf("shape types have no methods %+v", t)
+ }
+ tsym := TypeLinksym(t)
+ // Emit a marker relocation. The linker will know the type is converted
+ // to an interface if "from" is reachable.
+ r := obj.Addrel(from)
+ r.Sym = tsym
+ r.Type = objabi.R_USEIFACE
+}
+
+// MarkUsedIfaceMethod marks that an interface method is used in the current
+// function. n is OCALLINTER node.
+func MarkUsedIfaceMethod(n *ir.CallExpr) {
+ // skip unnamed functions (func _())
+ if ir.CurFunc.LSym == nil {
+ return
+ }
+ dot := n.X.(*ir.SelectorExpr)
+ ityp := dot.X.Type()
+ if ityp.HasShape() {
+ // Here we're calling a method on a generic interface. Something like:
+ //
+ // type I[T any] interface { foo() T }
+ // func f[T any](x I[T]) {
+ // ... = x.foo()
+ // }
+ // f[int](...)
+ // f[string](...)
+ //
+ // In this case, in f we're calling foo on a generic interface.
+ // Which method could that be? Normally we could match the method
+ // both by name and by type. But in this case we don't really know
+ // the type of the method we're calling. It could be func()int
+ // or func()string. So we match on just the function name, instead
+ // of both the name and the type used for the non-generic case below.
+ // TODO: instantiations at least know the shape of the instantiated
+ // type, and the linker could do more complicated matching using
+ // some sort of fuzzy shape matching. For now, only use the name
+ // of the method for matching.
+ r := obj.Addrel(ir.CurFunc.LSym)
+ // We use a separate symbol just to tell the linker the method name.
+ // (The symbol itself is not needed in the final binary.)
+ r.Sym = staticdata.StringSym(src.NoXPos, dot.Sel.Name)
+ r.Type = objabi.R_USEGENERICIFACEMETHOD
+ return
+ }
+
+ tsym := TypeLinksym(ityp)
+ r := obj.Addrel(ir.CurFunc.LSym)
+ r.Sym = tsym
+ // dot.Offset() is the method index * PtrSize (the offset of code pointer
+ // in itab).
+ midx := dot.Offset() / int64(types.PtrSize)
+ r.Add = InterfaceMethodOffset(ityp, midx)
+ r.Type = objabi.R_USEIFACEMETHOD
+}
+
+// getDictionary returns the dictionary for the given named generic function
+// or method, with the given type arguments.
+func getDictionary(gf *types.Sym, targs []*types.Type) ir.Node {
+ if len(targs) == 0 {
+ base.Fatalf("%s should have type arguments", gf.Name)
+ }
+ for _, t := range targs {
+ if t.HasShape() {
+ base.Fatalf("dictionary for %s should only use concrete types: %+v", gf.Name, t)
+ }
+ }
+
+ sym := typecheck.MakeDictSym(gf, targs, true)
+
+ // Dictionary should already have been generated by instantiateMethods().
+ // Extra dictionaries needed because of an inlined function should have been
+ // exported, and so available via Resolve.
+ if lsym := sym.Linksym(); len(lsym.P) == 0 {
+ in := typecheck.Resolve(ir.NewIdent(src.NoXPos, sym))
+ if in.Op() == ir.ONONAME {
+ base.Fatalf("Dictionary should have already been generated: %s.%s", sym.Pkg.Path, sym.Name)
+ }
+ sym = in.Sym()
+ }
+
+ // Make (or reuse) a node referencing the dictionary symbol.
+ var n *ir.Name
+ if sym.Def != nil {
+ n = sym.Def.(*ir.Name)
+ } else {
+ n = typecheck.NewName(sym)
+ n.SetType(types.Types[types.TUINTPTR]) // should probably be [...]uintptr, but doesn't really matter
+ n.SetTypecheck(1)
+ n.Class = ir.PEXTERN
+ sym.Def = n
+ }
+
+ // Return the address of the dictionary.
+ np := typecheck.NodAddr(n)
+ // Note: treat dictionary pointers as uintptrs, so they aren't pointers
+ // with respect to GC. That saves on stack scanning work, write barriers, etc.
+ // We can get away with it because dictionaries are global variables.
+ np.SetType(types.Types[types.TUINTPTR])
+ np.SetTypecheck(1)
+ return np
+}
+
+func deref(t *types.Type) *types.Type {
+ if t.IsPtr() {
+ return t.Elem()
+ }
+ return t
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-11 12:01:50 +0000