diff options
Diffstat (limited to 'src/runtime/iface.go')
-rw-r--r-- | src/runtime/iface.go | 686 |
1 files changed, 686 insertions, 0 deletions
diff --git a/src/runtime/iface.go b/src/runtime/iface.go new file mode 100644 index 0000000..bad49a3 --- /dev/null +++ b/src/runtime/iface.go @@ -0,0 +1,686 @@ +// Copyright 2014 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package runtime + +import ( + "internal/abi" + "internal/goarch" + "runtime/internal/atomic" + "runtime/internal/sys" + "unsafe" +) + +const itabInitSize = 512 + +var ( + itabLock mutex // lock for accessing itab table + itabTable = &itabTableInit // pointer to current table + itabTableInit = itabTableType{size: itabInitSize} // starter table +) + +// Note: change the formula in the mallocgc call in itabAdd if you change these fields. +type itabTableType struct { + size uintptr // length of entries array. Always a power of 2. + count uintptr // current number of filled entries. + entries [itabInitSize]*itab // really [size] large +} + +func itabHashFunc(inter *interfacetype, typ *_type) uintptr { + // compiler has provided some good hash codes for us. + return uintptr(inter.Type.Hash ^ typ.Hash) +} + +func getitab(inter *interfacetype, typ *_type, canfail bool) *itab { + if len(inter.Methods) == 0 { + throw("internal error - misuse of itab") + } + + // easy case + if typ.TFlag&abi.TFlagUncommon == 0 { + if canfail { + return nil + } + name := toRType(&inter.Type).nameOff(inter.Methods[0].Name) + panic(&TypeAssertionError{nil, typ, &inter.Type, name.Name()}) + } + + var m *itab + + // First, look in the existing table to see if we can find the itab we need. + // This is by far the most common case, so do it without locks. + // Use atomic to ensure we see any previous writes done by the thread + // that updates the itabTable field (with atomic.Storep in itabAdd). + t := (*itabTableType)(atomic.Loadp(unsafe.Pointer(&itabTable))) + if m = t.find(inter, typ); m != nil { + goto finish + } + + // Not found. Grab the lock and try again. + lock(&itabLock) + if m = itabTable.find(inter, typ); m != nil { + unlock(&itabLock) + goto finish + } + + // Entry doesn't exist yet. Make a new entry & add it. + m = (*itab)(persistentalloc(unsafe.Sizeof(itab{})+uintptr(len(inter.Methods)-1)*goarch.PtrSize, 0, &memstats.other_sys)) + m.inter = inter + m._type = typ + // The hash is used in type switches. However, compiler statically generates itab's + // for all interface/type pairs used in switches (which are added to itabTable + // in itabsinit). The dynamically-generated itab's never participate in type switches, + // and thus the hash is irrelevant. + // Note: m.hash is _not_ the hash used for the runtime itabTable hash table. + m.hash = 0 + m.init() + itabAdd(m) + unlock(&itabLock) +finish: + if m.fun[0] != 0 { + return m + } + if canfail { + return nil + } + // this can only happen if the conversion + // was already done once using the , ok form + // and we have a cached negative result. + // The cached result doesn't record which + // interface function was missing, so initialize + // the itab again to get the missing function name. + panic(&TypeAssertionError{concrete: typ, asserted: &inter.Type, missingMethod: m.init()}) +} + +// find finds the given interface/type pair in t. +// Returns nil if the given interface/type pair isn't present. +func (t *itabTableType) find(inter *interfacetype, typ *_type) *itab { + // Implemented using quadratic probing. + // Probe sequence is h(i) = h0 + i*(i+1)/2 mod 2^k. + // We're guaranteed to hit all table entries using this probe sequence. + mask := t.size - 1 + h := itabHashFunc(inter, typ) & mask + for i := uintptr(1); ; i++ { + p := (**itab)(add(unsafe.Pointer(&t.entries), h*goarch.PtrSize)) + // Use atomic read here so if we see m != nil, we also see + // the initializations of the fields of m. + // m := *p + m := (*itab)(atomic.Loadp(unsafe.Pointer(p))) + if m == nil { + return nil + } + if m.inter == inter && m._type == typ { + return m + } + h += i + h &= mask + } +} + +// itabAdd adds the given itab to the itab hash table. +// itabLock must be held. +func itabAdd(m *itab) { + // Bugs can lead to calling this while mallocing is set, + // typically because this is called while panicking. + // Crash reliably, rather than only when we need to grow + // the hash table. + if getg().m.mallocing != 0 { + throw("malloc deadlock") + } + + t := itabTable + if t.count >= 3*(t.size/4) { // 75% load factor + // Grow hash table. + // t2 = new(itabTableType) + some additional entries + // We lie and tell malloc we want pointer-free memory because + // all the pointed-to values are not in the heap. + t2 := (*itabTableType)(mallocgc((2+2*t.size)*goarch.PtrSize, nil, true)) + t2.size = t.size * 2 + + // Copy over entries. + // Note: while copying, other threads may look for an itab and + // fail to find it. That's ok, they will then try to get the itab lock + // and as a consequence wait until this copying is complete. + iterate_itabs(t2.add) + if t2.count != t.count { + throw("mismatched count during itab table copy") + } + // Publish new hash table. Use an atomic write: see comment in getitab. + atomicstorep(unsafe.Pointer(&itabTable), unsafe.Pointer(t2)) + // Adopt the new table as our own. + t = itabTable + // Note: the old table can be GC'ed here. + } + t.add(m) +} + +// add adds the given itab to itab table t. +// itabLock must be held. +func (t *itabTableType) add(m *itab) { + // See comment in find about the probe sequence. + // Insert new itab in the first empty spot in the probe sequence. + mask := t.size - 1 + h := itabHashFunc(m.inter, m._type) & mask + for i := uintptr(1); ; i++ { + p := (**itab)(add(unsafe.Pointer(&t.entries), h*goarch.PtrSize)) + m2 := *p + if m2 == m { + // A given itab may be used in more than one module + // and thanks to the way global symbol resolution works, the + // pointed-to itab may already have been inserted into the + // global 'hash'. + return + } + if m2 == nil { + // Use atomic write here so if a reader sees m, it also + // sees the correctly initialized fields of m. + // NoWB is ok because m is not in heap memory. + // *p = m + atomic.StorepNoWB(unsafe.Pointer(p), unsafe.Pointer(m)) + t.count++ + return + } + h += i + h &= mask + } +} + +// init fills in the m.fun array with all the code pointers for +// the m.inter/m._type pair. If the type does not implement the interface, +// it sets m.fun[0] to 0 and returns the name of an interface function that is missing. +// It is ok to call this multiple times on the same m, even concurrently. +func (m *itab) init() string { + inter := m.inter + typ := m._type + x := typ.Uncommon() + + // both inter and typ have method sorted by name, + // and interface names are unique, + // so can iterate over both in lock step; + // the loop is O(ni+nt) not O(ni*nt). + ni := len(inter.Methods) + nt := int(x.Mcount) + xmhdr := (*[1 << 16]abi.Method)(add(unsafe.Pointer(x), uintptr(x.Moff)))[:nt:nt] + j := 0 + methods := (*[1 << 16]unsafe.Pointer)(unsafe.Pointer(&m.fun[0]))[:ni:ni] + var fun0 unsafe.Pointer +imethods: + for k := 0; k < ni; k++ { + i := &inter.Methods[k] + itype := toRType(&inter.Type).typeOff(i.Typ) + name := toRType(&inter.Type).nameOff(i.Name) + iname := name.Name() + ipkg := pkgPath(name) + if ipkg == "" { + ipkg = inter.PkgPath.Name() + } + for ; j < nt; j++ { + t := &xmhdr[j] + rtyp := toRType(typ) + tname := rtyp.nameOff(t.Name) + if rtyp.typeOff(t.Mtyp) == itype && tname.Name() == iname { + pkgPath := pkgPath(tname) + if pkgPath == "" { + pkgPath = rtyp.nameOff(x.PkgPath).Name() + } + if tname.IsExported() || pkgPath == ipkg { + ifn := rtyp.textOff(t.Ifn) + if k == 0 { + fun0 = ifn // we'll set m.fun[0] at the end + } else { + methods[k] = ifn + } + continue imethods + } + } + } + // didn't find method + m.fun[0] = 0 + return iname + } + m.fun[0] = uintptr(fun0) + return "" +} + +func itabsinit() { + lockInit(&itabLock, lockRankItab) + lock(&itabLock) + for _, md := range activeModules() { + for _, i := range md.itablinks { + itabAdd(i) + } + } + unlock(&itabLock) +} + +// panicdottypeE is called when doing an e.(T) conversion and the conversion fails. +// have = the dynamic type we have. +// want = the static type we're trying to convert to. +// iface = the static type we're converting from. +func panicdottypeE(have, want, iface *_type) { + panic(&TypeAssertionError{iface, have, want, ""}) +} + +// panicdottypeI is called when doing an i.(T) conversion and the conversion fails. +// Same args as panicdottypeE, but "have" is the dynamic itab we have. +func panicdottypeI(have *itab, want, iface *_type) { + var t *_type + if have != nil { + t = have._type + } + panicdottypeE(t, want, iface) +} + +// panicnildottype is called when doing an i.(T) conversion and the interface i is nil. +// want = the static type we're trying to convert to. +func panicnildottype(want *_type) { + panic(&TypeAssertionError{nil, nil, want, ""}) + // TODO: Add the static type we're converting from as well. + // It might generate a better error message. + // Just to match other nil conversion errors, we don't for now. +} + +// The specialized convTx routines need a type descriptor to use when calling mallocgc. +// We don't need the type to be exact, just to have the correct size, alignment, and pointer-ness. +// However, when debugging, it'd be nice to have some indication in mallocgc where the types came from, +// so we use named types here. +// We then construct interface values of these types, +// and then extract the type word to use as needed. +type ( + uint16InterfacePtr uint16 + uint32InterfacePtr uint32 + uint64InterfacePtr uint64 + stringInterfacePtr string + sliceInterfacePtr []byte +) + +var ( + uint16Eface any = uint16InterfacePtr(0) + uint32Eface any = uint32InterfacePtr(0) + uint64Eface any = uint64InterfacePtr(0) + stringEface any = stringInterfacePtr("") + sliceEface any = sliceInterfacePtr(nil) + + uint16Type *_type = efaceOf(&uint16Eface)._type + uint32Type *_type = efaceOf(&uint32Eface)._type + uint64Type *_type = efaceOf(&uint64Eface)._type + stringType *_type = efaceOf(&stringEface)._type + sliceType *_type = efaceOf(&sliceEface)._type +) + +// The conv and assert functions below do very similar things. +// The convXXX functions are guaranteed by the compiler to succeed. +// The assertXXX functions may fail (either panicking or returning false, +// depending on whether they are 1-result or 2-result). +// The convXXX functions succeed on a nil input, whereas the assertXXX +// functions fail on a nil input. + +// convT converts a value of type t, which is pointed to by v, to a pointer that can +// be used as the second word of an interface value. +func convT(t *_type, v unsafe.Pointer) unsafe.Pointer { + if raceenabled { + raceReadObjectPC(t, v, getcallerpc(), abi.FuncPCABIInternal(convT)) + } + if msanenabled { + msanread(v, t.Size_) + } + if asanenabled { + asanread(v, t.Size_) + } + x := mallocgc(t.Size_, t, true) + typedmemmove(t, x, v) + return x +} +func convTnoptr(t *_type, v unsafe.Pointer) unsafe.Pointer { + // TODO: maybe take size instead of type? + if raceenabled { + raceReadObjectPC(t, v, getcallerpc(), abi.FuncPCABIInternal(convTnoptr)) + } + if msanenabled { + msanread(v, t.Size_) + } + if asanenabled { + asanread(v, t.Size_) + } + + x := mallocgc(t.Size_, t, false) + memmove(x, v, t.Size_) + return x +} + +func convT16(val uint16) (x unsafe.Pointer) { + if val < uint16(len(staticuint64s)) { + x = unsafe.Pointer(&staticuint64s[val]) + if goarch.BigEndian { + x = add(x, 6) + } + } else { + x = mallocgc(2, uint16Type, false) + *(*uint16)(x) = val + } + return +} + +func convT32(val uint32) (x unsafe.Pointer) { + if val < uint32(len(staticuint64s)) { + x = unsafe.Pointer(&staticuint64s[val]) + if goarch.BigEndian { + x = add(x, 4) + } + } else { + x = mallocgc(4, uint32Type, false) + *(*uint32)(x) = val + } + return +} + +func convT64(val uint64) (x unsafe.Pointer) { + if val < uint64(len(staticuint64s)) { + x = unsafe.Pointer(&staticuint64s[val]) + } else { + x = mallocgc(8, uint64Type, false) + *(*uint64)(x) = val + } + return +} + +func convTstring(val string) (x unsafe.Pointer) { + if val == "" { + x = unsafe.Pointer(&zeroVal[0]) + } else { + x = mallocgc(unsafe.Sizeof(val), stringType, true) + *(*string)(x) = val + } + return +} + +func convTslice(val []byte) (x unsafe.Pointer) { + // Note: this must work for any element type, not just byte. + if (*slice)(unsafe.Pointer(&val)).array == nil { + x = unsafe.Pointer(&zeroVal[0]) + } else { + x = mallocgc(unsafe.Sizeof(val), sliceType, true) + *(*[]byte)(x) = val + } + return +} + +func assertE2I(inter *interfacetype, t *_type) *itab { + if t == nil { + // explicit conversions require non-nil interface value. + panic(&TypeAssertionError{nil, nil, &inter.Type, ""}) + } + return getitab(inter, t, false) +} + +func assertE2I2(inter *interfacetype, t *_type) *itab { + if t == nil { + return nil + } + return getitab(inter, t, true) +} + +// typeAssert builds an itab for the concrete type t and the +// interface type s.Inter. If the conversion is not possible it +// panics if s.CanFail is false and returns nil if s.CanFail is true. +func typeAssert(s *abi.TypeAssert, t *_type) *itab { + var tab *itab + if t == nil { + if !s.CanFail { + panic(&TypeAssertionError{nil, nil, &s.Inter.Type, ""}) + } + } else { + tab = getitab(s.Inter, t, s.CanFail) + } + + if !abi.UseInterfaceSwitchCache(GOARCH) { + return tab + } + + // Maybe update the cache, so the next time the generated code + // doesn't need to call into the runtime. + if cheaprand()&1023 != 0 { + // Only bother updating the cache ~1 in 1000 times. + return tab + } + // Load the current cache. + oldC := (*abi.TypeAssertCache)(atomic.Loadp(unsafe.Pointer(&s.Cache))) + + if cheaprand()&uint32(oldC.Mask) != 0 { + // As cache gets larger, choose to update it less often + // so we can amortize the cost of building a new cache. + return tab + } + + // Make a new cache. + newC := buildTypeAssertCache(oldC, t, tab) + + // Update cache. Use compare-and-swap so if multiple threads + // are fighting to update the cache, at least one of their + // updates will stick. + atomic_casPointer((*unsafe.Pointer)(unsafe.Pointer(&s.Cache)), unsafe.Pointer(oldC), unsafe.Pointer(newC)) + + return tab +} + +func buildTypeAssertCache(oldC *abi.TypeAssertCache, typ *_type, tab *itab) *abi.TypeAssertCache { + oldEntries := unsafe.Slice(&oldC.Entries[0], oldC.Mask+1) + + // Count the number of entries we need. + n := 1 + for _, e := range oldEntries { + if e.Typ != 0 { + n++ + } + } + + // Figure out how big a table we need. + // We need at least one more slot than the number of entries + // so that we are guaranteed an empty slot (for termination). + newN := n * 2 // make it at most 50% full + newN = 1 << sys.Len64(uint64(newN-1)) // round up to a power of 2 + + // Allocate the new table. + newSize := unsafe.Sizeof(abi.TypeAssertCache{}) + uintptr(newN-1)*unsafe.Sizeof(abi.TypeAssertCacheEntry{}) + newC := (*abi.TypeAssertCache)(mallocgc(newSize, nil, true)) + newC.Mask = uintptr(newN - 1) + newEntries := unsafe.Slice(&newC.Entries[0], newN) + + // Fill the new table. + addEntry := func(typ *_type, tab *itab) { + h := int(typ.Hash) & (newN - 1) + for { + if newEntries[h].Typ == 0 { + newEntries[h].Typ = uintptr(unsafe.Pointer(typ)) + newEntries[h].Itab = uintptr(unsafe.Pointer(tab)) + return + } + h = (h + 1) & (newN - 1) + } + } + for _, e := range oldEntries { + if e.Typ != 0 { + addEntry((*_type)(unsafe.Pointer(e.Typ)), (*itab)(unsafe.Pointer(e.Itab))) + } + } + addEntry(typ, tab) + + return newC +} + +// Empty type assert cache. Contains one entry with a nil Typ (which +// causes a cache lookup to fail immediately.) +var emptyTypeAssertCache = abi.TypeAssertCache{Mask: 0} + +// interfaceSwitch compares t against the list of cases in s. +// If t matches case i, interfaceSwitch returns the case index i and +// an itab for the pair <t, s.Cases[i]>. +// If there is no match, return N,nil, where N is the number +// of cases. +func interfaceSwitch(s *abi.InterfaceSwitch, t *_type) (int, *itab) { + cases := unsafe.Slice(&s.Cases[0], s.NCases) + + // Results if we don't find a match. + case_ := len(cases) + var tab *itab + + // Look through each case in order. + for i, c := range cases { + tab = getitab(c, t, true) + if tab != nil { + case_ = i + break + } + } + + if !abi.UseInterfaceSwitchCache(GOARCH) { + return case_, tab + } + + // Maybe update the cache, so the next time the generated code + // doesn't need to call into the runtime. + if cheaprand()&1023 != 0 { + // Only bother updating the cache ~1 in 1000 times. + // This ensures we don't waste memory on switches, or + // switch arguments, that only happen a few times. + return case_, tab + } + // Load the current cache. + oldC := (*abi.InterfaceSwitchCache)(atomic.Loadp(unsafe.Pointer(&s.Cache))) + + if cheaprand()&uint32(oldC.Mask) != 0 { + // As cache gets larger, choose to update it less often + // so we can amortize the cost of building a new cache + // (that cost is linear in oldc.Mask). + return case_, tab + } + + // Make a new cache. + newC := buildInterfaceSwitchCache(oldC, t, case_, tab) + + // Update cache. Use compare-and-swap so if multiple threads + // are fighting to update the cache, at least one of their + // updates will stick. + atomic_casPointer((*unsafe.Pointer)(unsafe.Pointer(&s.Cache)), unsafe.Pointer(oldC), unsafe.Pointer(newC)) + + return case_, tab +} + +// buildInterfaceSwitchCache constructs an interface switch cache +// containing all the entries from oldC plus the new entry +// (typ,case_,tab). +func buildInterfaceSwitchCache(oldC *abi.InterfaceSwitchCache, typ *_type, case_ int, tab *itab) *abi.InterfaceSwitchCache { + oldEntries := unsafe.Slice(&oldC.Entries[0], oldC.Mask+1) + + // Count the number of entries we need. + n := 1 + for _, e := range oldEntries { + if e.Typ != 0 { + n++ + } + } + + // Figure out how big a table we need. + // We need at least one more slot than the number of entries + // so that we are guaranteed an empty slot (for termination). + newN := n * 2 // make it at most 50% full + newN = 1 << sys.Len64(uint64(newN-1)) // round up to a power of 2 + + // Allocate the new table. + newSize := unsafe.Sizeof(abi.InterfaceSwitchCache{}) + uintptr(newN-1)*unsafe.Sizeof(abi.InterfaceSwitchCacheEntry{}) + newC := (*abi.InterfaceSwitchCache)(mallocgc(newSize, nil, true)) + newC.Mask = uintptr(newN - 1) + newEntries := unsafe.Slice(&newC.Entries[0], newN) + + // Fill the new table. + addEntry := func(typ *_type, case_ int, tab *itab) { + h := int(typ.Hash) & (newN - 1) + for { + if newEntries[h].Typ == 0 { + newEntries[h].Typ = uintptr(unsafe.Pointer(typ)) + newEntries[h].Case = case_ + newEntries[h].Itab = uintptr(unsafe.Pointer(tab)) + return + } + h = (h + 1) & (newN - 1) + } + } + for _, e := range oldEntries { + if e.Typ != 0 { + addEntry((*_type)(unsafe.Pointer(e.Typ)), e.Case, (*itab)(unsafe.Pointer(e.Itab))) + } + } + addEntry(typ, case_, tab) + + return newC +} + +// Empty interface switch cache. Contains one entry with a nil Typ (which +// causes a cache lookup to fail immediately.) +var emptyInterfaceSwitchCache = abi.InterfaceSwitchCache{Mask: 0} + +//go:linkname reflect_ifaceE2I reflect.ifaceE2I +func reflect_ifaceE2I(inter *interfacetype, e eface, dst *iface) { + *dst = iface{assertE2I(inter, e._type), e.data} +} + +//go:linkname reflectlite_ifaceE2I internal/reflectlite.ifaceE2I +func reflectlite_ifaceE2I(inter *interfacetype, e eface, dst *iface) { + *dst = iface{assertE2I(inter, e._type), e.data} +} + +func iterate_itabs(fn func(*itab)) { + // Note: only runs during stop the world or with itabLock held, + // so no other locks/atomics needed. + t := itabTable + for i := uintptr(0); i < t.size; i++ { + m := *(**itab)(add(unsafe.Pointer(&t.entries), i*goarch.PtrSize)) + if m != nil { + fn(m) + } + } +} + +// staticuint64s is used to avoid allocating in convTx for small integer values. +var staticuint64s = [...]uint64{ + 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, + 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, + 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, + 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, + 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, + 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, + 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, + 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, + 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, + 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, + 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, + 0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f, + 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, + 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, + 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, + 0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f, + 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, + 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, + 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, + 0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f, + 0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, + 0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf, + 0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7, + 0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf, + 0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7, + 0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf, + 0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, + 0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf, + 0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, + 0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef, + 0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, + 0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff, +} + +// The linker redirects a reference of a method that it determined +// unreachable to a reference to this function, so it will throw if +// ever called. +func unreachableMethod() { + throw("unreachable method called. linker bug?") +} |