| // 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_test |
| |
| import ( |
| "bytes" |
| "runtime" |
| "testing" |
| ) |
| |
| // TestGCInfo tests that various objects in heap, data and bss receive correct GC pointer type info. |
| func TestGCInfo(t *testing.T) { |
| verifyGCInfo(t, "bss ScalarPtr", &bssScalarPtr, infoScalarPtr) |
| verifyGCInfo(t, "bss PtrScalar", &bssPtrScalar, infoPtrScalar) |
| verifyGCInfo(t, "bss BigStruct", &bssBigStruct, infoBigStruct()) |
| verifyGCInfo(t, "bss string", &bssString, infoString) |
| verifyGCInfo(t, "bss slice", &bssSlice, infoSlice) |
| verifyGCInfo(t, "bss eface", &bssEface, infoEface) |
| verifyGCInfo(t, "bss iface", &bssIface, infoIface) |
| |
| verifyGCInfo(t, "data ScalarPtr", &dataScalarPtr, infoScalarPtr) |
| verifyGCInfo(t, "data PtrScalar", &dataPtrScalar, infoPtrScalar) |
| verifyGCInfo(t, "data BigStruct", &dataBigStruct, infoBigStruct()) |
| verifyGCInfo(t, "data string", &dataString, infoString) |
| verifyGCInfo(t, "data slice", &dataSlice, infoSlice) |
| verifyGCInfo(t, "data eface", &dataEface, infoEface) |
| verifyGCInfo(t, "data iface", &dataIface, infoIface) |
| |
| verifyGCInfo(t, "stack ScalarPtr", new(ScalarPtr), infoScalarPtr) |
| verifyGCInfo(t, "stack PtrScalar", new(PtrScalar), infoPtrScalar) |
| verifyGCInfo(t, "stack BigStruct", new(BigStruct), infoBigStruct()) |
| verifyGCInfo(t, "stack string", new(string), infoString) |
| verifyGCInfo(t, "stack slice", new([]string), infoSlice) |
| verifyGCInfo(t, "stack eface", new(interface{}), infoEface) |
| verifyGCInfo(t, "stack iface", new(Iface), infoIface) |
| |
| for i := 0; i < 10; i++ { |
| verifyGCInfo(t, "heap ScalarPtr", escape(new(ScalarPtr)), infoScalarPtr) |
| verifyGCInfo(t, "heap PtrScalar", escape(new(PtrScalar)), infoPtrScalar) |
| verifyGCInfo(t, "heap BigStruct", escape(new(BigStruct)), infoBigStruct()) |
| verifyGCInfo(t, "heap string", escape(new(string)), infoString) |
| verifyGCInfo(t, "heap eface", escape(new(interface{})), infoEface) |
| verifyGCInfo(t, "heap iface", escape(new(Iface)), infoIface) |
| } |
| |
| } |
| |
| func verifyGCInfo(t *testing.T, name string, p interface{}, mask0 []byte) { |
| mask := runtime.GCMask(p) |
| if len(mask) > len(mask0) { |
| mask0 = append(mask0, typeDead) |
| mask = mask[:len(mask0)] |
| } |
| if bytes.Compare(mask, mask0) != 0 { |
| t.Errorf("bad GC program for %v:\nwant %+v\ngot %+v", name, mask0, mask) |
| return |
| } |
| } |
| |
| func nonStackInfo(mask []byte) []byte { |
| // typeDead is replaced with typeScalar everywhere except stacks. |
| mask1 := make([]byte, len(mask)) |
| for i, v := range mask { |
| if v == typeDead { |
| v = typeScalar |
| } |
| mask1[i] = v |
| } |
| return mask1 |
| } |
| |
| var gcinfoSink interface{} |
| |
| func escape(p interface{}) interface{} { |
| gcinfoSink = p |
| return p |
| } |
| |
| const ( |
| typeDead = iota |
| typeScalar |
| typePointer |
| ) |
| |
| const ( |
| BitsString = iota // unused |
| BitsSlice // unused |
| BitsIface |
| BitsEface |
| ) |
| |
| type ScalarPtr struct { |
| q int |
| w *int |
| e int |
| r *int |
| t int |
| y *int |
| } |
| |
| var infoScalarPtr = []byte{typeScalar, typePointer, typeScalar, typePointer, typeScalar, typePointer} |
| |
| type PtrScalar struct { |
| q *int |
| w int |
| e *int |
| r int |
| t *int |
| y int |
| } |
| |
| var infoPtrScalar = []byte{typePointer, typeScalar, typePointer, typeScalar, typePointer, typeScalar} |
| |
| type BigStruct struct { |
| q *int |
| w byte |
| e [17]byte |
| r []byte |
| t int |
| y uint16 |
| u uint64 |
| i string |
| } |
| |
| func infoBigStruct() []byte { |
| switch runtime.GOARCH { |
| case "386", "arm": |
| return []byte{ |
| typePointer, // q *int |
| typeScalar, typeScalar, typeScalar, typeScalar, typeScalar, // w byte; e [17]byte |
| typePointer, typeScalar, typeScalar, // r []byte |
| typeScalar, typeScalar, typeScalar, typeScalar, // t int; y uint16; u uint64 |
| typePointer, typeScalar, // i string |
| } |
| case "arm64", "amd64", "ppc64", "ppc64le": |
| return []byte{ |
| typePointer, // q *int |
| typeScalar, typeScalar, typeScalar, // w byte; e [17]byte |
| typePointer, typeScalar, typeScalar, // r []byte |
| typeScalar, typeScalar, typeScalar, // t int; y uint16; u uint64 |
| typePointer, typeScalar, // i string |
| } |
| case "amd64p32": |
| return []byte{ |
| typePointer, // q *int |
| typeScalar, typeScalar, typeScalar, typeScalar, typeScalar, // w byte; e [17]byte |
| typePointer, typeScalar, typeScalar, // r []byte |
| typeScalar, typeScalar, typeScalar, typeScalar, typeScalar, // t int; y uint16; u uint64 |
| typePointer, typeScalar, // i string |
| } |
| default: |
| panic("unknown arch") |
| } |
| } |
| |
| type Iface interface { |
| f() |
| } |
| |
| type IfaceImpl int |
| |
| func (IfaceImpl) f() { |
| } |
| |
| var ( |
| // BSS |
| bssScalarPtr ScalarPtr |
| bssPtrScalar PtrScalar |
| bssBigStruct BigStruct |
| bssString string |
| bssSlice []string |
| bssEface interface{} |
| bssIface Iface |
| |
| // DATA |
| dataScalarPtr = ScalarPtr{q: 1} |
| dataPtrScalar = PtrScalar{w: 1} |
| dataBigStruct = BigStruct{w: 1} |
| dataString = "foo" |
| dataSlice = []string{"foo"} |
| dataEface interface{} = 42 |
| dataIface Iface = IfaceImpl(42) |
| |
| infoString = []byte{typePointer, typeScalar} |
| infoSlice = []byte{typePointer, typeScalar, typeScalar} |
| infoEface = []byte{typePointer, typePointer} |
| infoIface = []byte{typePointer, typePointer} |
| ) |