runtime,reflect: clean duplicate definitions itab

For #65355

Change-Id: If676bffe28ae3f20e4ed15a56993811bee05ef22

Author: qiulaidongfeng

src/cmd/internal/objabi/pkgspecial.go

@@ -57,6 +57,8 @@ var runtimePkgs = []string{
 	"internal/godebugs",
 	"internal/goexperiment",
 	"internal/goos",
+
+	"internal/runtime/itab",
 }
 
 // extraNoInstrumentPkgs is the set of packages in addition to runtimePkgs that

src/cmd/link/internal/ld/dwarf.go

@@ -1786,7 +1786,7 @@ func dwarfGenerateDebugInfo(ctxt *Link) {
 		"type:internal/abi.SliceType",
 		"type:internal/abi.StructType",
 		"type:internal/abi.InterfaceType",
-		"type:runtime.itab",
+		"type:internal/runtime/itab.Itab",
 		"type:internal/abi.Imethod"} {
 		d.defgotype(d.lookupOrDiag(typ))
 	}

src/cmd/link/internal/ld/dwarf_test.go

@@ -65,7 +65,7 @@ func TestRuntimeTypesPresent(t *testing.T) {
 		"internal/abi.SliceType":     true,
 		"internal/abi.StructType":    true,
 		"internal/abi.InterfaceType": true,
-		"runtime.itab":               true,
+		"internal/runtime/itab.Itab": true,
 	}
 
 	found := findTypes(t, dwarf, want)

src/go/build/deps_test.go

@@ -56,6 +56,8 @@ var depsRules = `
 
 	unsafe < maps;
 
+	internal/abi < internal/runtime/itab;
+
 	# RUNTIME is the core runtime group of packages, all of them very light-weight.
 	internal/abi,
 	internal/chacha8rand,
@@ -64,7 +66,8 @@ var depsRules = `
 	internal/goarch,
 	internal/godebugs,
 	internal/goexperiment,
-	internal/goos
+	internal/goos,
+	internal/runtime/itab
 	< internal/bytealg
 	< internal/itoa
 	< internal/unsafeheader
@@ -189,7 +192,7 @@ var depsRules = `
 
 	# FMT is OS (which includes string routines) plus reflect and fmt.
 	# It does not include package log, which should be avoided in core packages.
-	arena, strconv, unicode
+	arena, strconv, unicode, internal/runtime/itab
 	< reflect;
 
 	os, reflect

src/internal/runtime/itab/itab.go

@@ -0,0 +1,19 @@
+// Copyright 2024 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 itab
+
+import "internal/abi"
+
+// layout of Itab known to compilers
+// allocated in non-garbage-collected memory
+// Needs to be in sync with
+// ../cmd/compile/internal/reflectdata/reflect.go:/^func.WritePluginTable.
+type Itab struct {
+	Inter *abi.InterfaceType
+	Type  *abi.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.
+}

src/reflect/value.go

@@ -9,6 +9,7 @@ import (
 	"internal/abi"
 	"internal/goarch"
 	"internal/itoa"
+	"internal/runtime/itab"
 	"internal/unsafeheader"
 	"math"
 	"runtime"
@@ -208,14 +209,7 @@ type emptyInterface struct {
 
 // nonEmptyInterface is the header for an interface value with methods.
 type nonEmptyInterface struct {
-	// see ../runtime/iface.go:/Itab
-	itab *struct {
-		ityp *abi.Type // static interface type
-		typ  *abi.Type // dynamic concrete type
-		hash uint32    // copy of typ.hash
-		_    [4]byte
-		fun  [100000]unsafe.Pointer // method table
-	}
+	itab *itab.Itab
 	word unsafe.Pointer
 }
 
@@ -883,7 +877,7 @@ func callReflect(ctxt *makeFuncImpl, frame unsafe.Pointer, retValid *bool, regs
 // The return value t gives the method type signature (without the receiver).
 // The return value fn is a pointer to the method code.
 func methodReceiver(op string, v Value, methodIndex int) (rcvrtype *abi.Type, t *funcType, fn unsafe.Pointer) {
-	i := methodIndex
+	i := uintptr(methodIndex)
 	if v.typ().Kind() == abi.Interface {
 		tt := (*interfaceType)(unsafe.Pointer(v.typ()))
 		if uint(i) >= uint(len(tt.Methods)) {
@@ -897,8 +891,8 @@ func methodReceiver(op string, v Value, methodIndex int) (rcvrtype *abi.Type, t
 		if iface.itab == nil {
 			panic("reflect: " + op + " of method on nil interface value")
 		}
-		rcvrtype = iface.itab.typ
-		fn = unsafe.Pointer(&iface.itab.fun[i])
+		rcvrtype = iface.itab.Type
+		fn = unsafe.Add(unsafe.Pointer(&iface.itab.Fun[0]), unsafe.Sizeof(iface.itab.Fun[0])*i)
 		t = (*funcType)(unsafe.Pointer(tt.typeOff(m.Typ)))
 	} else {
 		rcvrtype = v.typ()

src/runtime/alg.go

@@ -8,6 +8,7 @@ import (
 	"internal/abi"
 	"internal/cpu"
 	"internal/goarch"
+	"internal/runtime/itab"
 	"unsafe"
 )
 
@@ -100,7 +101,7 @@ func interhash(p unsafe.Pointer, h uintptr) uintptr {
 	if tab == nil {
 		return h
 	}
-	t := tab._type
+	t := tab.Type
 	if t.Equal == nil {
 		// Check hashability here. We could do this check inside
 		// typehash, but we want to report the topmost type in
@@ -223,7 +224,7 @@ func mapKeyError2(t *_type, p unsafe.Pointer) error {
 			if a.tab == nil {
 				return nil
 			}
-			t = a.tab._type
+			t = a.tab.Type
 			pdata = &a.data
 		}
 
@@ -325,11 +326,11 @@ func efaceeq(t *_type, x, y unsafe.Pointer) bool {
 	}
 	return eq(x, y)
 }
-func ifaceeq(tab *itab, x, y unsafe.Pointer) bool {
+func ifaceeq(tab *itab.Itab, x, y unsafe.Pointer) bool {
 	if tab == nil {
 		return true
 	}
-	t := tab._type
+	t := tab.Type
 	eq := t.Equal
 	if eq == nil {
 		panic(errorString("comparing uncomparable type " + toRType(t).string()))

src/runtime/heapdump.go

@@ -15,6 +15,7 @@ import (
 	"internal/abi"
 	"internal/goarch"
 	"internal/goexperiment"
+	"internal/runtime/itab"
 	"unsafe"
 )
 
@@ -539,8 +540,8 @@ func dumpparams() {
 	dumpint(uint64(ncpu))
 }
 
-func itab_callback(tab *itab) {
-	t := tab._type
+func itab_callback(tab *itab.Itab) {
+	t := tab.Type
 	dumptype(t)
 	dumpint(tagItab)
 	dumpint(uint64(uintptr(unsafe.Pointer(tab))))