objc: add Ivar support and Objc Tests (#15)

commit: 8c4da10ed8047992d54be93b4c25a9af73ac8d88
author: TotallyGamerJet · 4y ago · 2022-08-11 02:21 UTC
committer: GitHub · 4y ago · 2022-08-11 02:21 UTC
parent: 0f3e4f8
signature: GPG Unverified4AEE18F83AFDEB23 The key is unknown

3 files · +127 -12

M objc/objc_runtime_darwin.go +52 -11


@@ -7,6 +7,7 @@ package objc
7	7
8	8		import (
9	9		"fmt"
	10	+	"math"
10	11		"reflect"
11	12		"runtime"
12	13		"unsafe"

@@ -21,15 +22,18 @@ import (
21	22		var (
22	23		objc = purego.Dlopen("/usr/lib/libobjc.A.dylib", purego.RTLD_GLOBAL)
23	24
24		-	objc_msgSend = purego.Dlsym(objc, "objc_msgSend")
25		-	objc_msgSendSuper2 = purego.Dlsym(objc, "objc_msgSendSuper2")
26		-	objc_getClass = purego.Dlsym(objc, "objc_getClass")
27		-	objc_allocateClassPair = purego.Dlsym(objc, "objc_allocateClassPair")
28		-	objc_registerClassPair = purego.Dlsym(objc, "objc_registerClassPair")
29		-	sel_registerName = purego.Dlsym(objc, "sel_registerName")
30		-	class_getSuperclass = purego.Dlsym(objc, "class_getSuperclass")
31		-	class_addMethod = purego.Dlsym(objc, "class_addMethod")
32		-	object_getClass = purego.Dlsym(objc, "object_getClass")
	25	+	objc_msgSend = purego.Dlsym(objc, "objc_msgSend")
	26	+	objc_msgSendSuper2 = purego.Dlsym(objc, "objc_msgSendSuper2")
	27	+	objc_getClass = purego.Dlsym(objc, "objc_getClass")
	28	+	objc_allocateClassPair = purego.Dlsym(objc, "objc_allocateClassPair")
	29	+	objc_registerClassPair = purego.Dlsym(objc, "objc_registerClassPair")
	30	+	sel_registerName = purego.Dlsym(objc, "sel_registerName")
	31	+	class_getSuperclass = purego.Dlsym(objc, "class_getSuperclass")
	32	+	class_getInstanceVariable = purego.Dlsym(objc, "class_getInstanceVariable")
	33	+	class_addMethod = purego.Dlsym(objc, "class_addMethod")
	34	+	class_addIvar = purego.Dlsym(objc, "class_addIvar")
	35	+	ivar_getOffset = purego.Dlsym(objc, "ivar_getOffset")
	36	+	object_getClass = purego.Dlsym(objc, "object_getClass")
33	37		)
34	38
35	39		// ID is an opaque pointer to some Objective-C object

@@ -152,17 +156,54 @@ func (c Class) AddMethod(name SEL, imp _IMP, types string) bool {
152	156		return byte(ret) != 0
153	157		}
154	158
155		-	// Register registers a class that was allocated using objc_allocateClassPair.
	159	+	// AddIvar adds a new instance variable to a class.
	160	+	// It may only be called after AllocateClassPair and before Register.
	161	+	// Adding an instance variable to an existing class is not supported.
	162	+	// The class must not be a metaclass. Adding an instance variable to a metaclass is not supported.
	163	+	// It takes the instance of the type of the Ivar and a string representing the type.
	164	+	func (c Class) AddIvar(name string, ty interface{}, types string) bool {
	165	+	n := strings.CString(name)
	166	+	t := strings.CString(types)
	167	+	typeOf := reflect.TypeOf(ty)
	168	+	size := typeOf.Size()
	169	+	alignment := uint8(math.Log2(float64(typeOf.Align())))
	170	+	ret, _, _ := purego.SyscallN(class_addIvar, uintptr(c), uintptr(unsafe.Pointer(n)), size, uintptr(alignment), uintptr(unsafe.Pointer(t)))
	171	+	runtime.KeepAlive(n)
	172	+	runtime.KeepAlive(t)
	173	+	return byte(ret) != 0
	174	+	}
	175	+
	176	+	// InstanceVariable returns an Ivar data structure containing information about the instance variable specified by name.
	177	+	func (c Class) InstanceVariable(name string) Ivar {
	178	+	n := strings.CString(name)
	179	+	ret, _, _ := purego.SyscallN(class_getInstanceVariable, uintptr(c), uintptr(unsafe.Pointer(n)))
	180	+	runtime.KeepAlive(n)
	181	+	return Ivar(ret)
	182	+	}
	183	+
	184	+	// Register registers a class that was allocated using AllocateClassPair.
156	185		// It can now be used to make objects by sending it either alloc and init or new.
157	186		func (c Class) Register() {
158	187		purego.SyscallN(objc_registerClassPair, uintptr(c))
159	188		}
160	189
	190	+	// Ivar an opaque type that represents an instance variable.
	191	+	type Ivar uintptr
	192	+
	193	+	// Offset returns the offset of an instance variable that can be used to assign and read the Ivar's value.
	194	+	//
	195	+	// For instance variables of type id or other object types, call Ivar and SetIvar instead
	196	+	// of using this offset to access the instance variable data directly.
	197	+	func (i Ivar) Offset() uintptr {
	198	+	ret, _, _ := purego.SyscallN(ivar_getOffset, uintptr(i))
	199	+	return ret
	200	+	}
	201	+
161	202		// _IMP is unexported so that the only way to make this type is by providing a Go function and casting
162	203		// it with the IMP function
163	204		type _IMP uintptr
164	205
165		-	// IMP takes a Go function that takes (id, SEL) as its first two arguments. It returns an _IMP function
	206	+	// IMP takes a Go function that takes (ID, SEL) as its first two arguments. It returns an _IMP function
166	207		// pointer that can be called by Objective-C code. The function pointer is never deallocated.
167	208		func IMP(fn interface{}) _IMP {
168	209		// this is only here so that it is easier to port C code to Go.


@@ -7,6 +7,7 @@ package objc
7			7
8		import (	8		import (
9		"fmt"	9		"fmt"
			10	+	"math"
10		"reflect"	11		"reflect"
11		"runtime"	12		"runtime"
12		"unsafe"	13		"unsafe"

@@ -21,15 +22,18 @@ import (
21		var (	22		var (
22		objc = purego.Dlopen("/usr/lib/libobjc.A.dylib", purego.RTLD_GLOBAL)	23		objc = purego.Dlopen("/usr/lib/libobjc.A.dylib", purego.RTLD_GLOBAL)
23			24
24	-	objc_msgSend = purego.Dlsym(objc, "objc_msgSend")	25	+	objc_msgSend = purego.Dlsym(objc, "objc_msgSend")
25	-	objc_msgSendSuper2 = purego.Dlsym(objc, "objc_msgSendSuper2")	26	+	objc_msgSendSuper2 = purego.Dlsym(objc, "objc_msgSendSuper2")
26	-	objc_getClass = purego.Dlsym(objc, "objc_getClass")	27	+	objc_getClass = purego.Dlsym(objc, "objc_getClass")
27	-	objc_allocateClassPair = purego.Dlsym(objc, "objc_allocateClassPair")	28	+	objc_allocateClassPair = purego.Dlsym(objc, "objc_allocateClassPair")
28	-	objc_registerClassPair = purego.Dlsym(objc, "objc_registerClassPair")	29	+	objc_registerClassPair = purego.Dlsym(objc, "objc_registerClassPair")
29	-	sel_registerName = purego.Dlsym(objc, "sel_registerName")	30	+	sel_registerName = purego.Dlsym(objc, "sel_registerName")
30	-	class_getSuperclass = purego.Dlsym(objc, "class_getSuperclass")	31	+	class_getSuperclass = purego.Dlsym(objc, "class_getSuperclass")
31	-	class_addMethod = purego.Dlsym(objc, "class_addMethod")	32	+	class_getInstanceVariable = purego.Dlsym(objc, "class_getInstanceVariable")
32	-	object_getClass = purego.Dlsym(objc, "object_getClass")	33	+	class_addMethod = purego.Dlsym(objc, "class_addMethod")
			34	+	class_addIvar = purego.Dlsym(objc, "class_addIvar")
			35	+	ivar_getOffset = purego.Dlsym(objc, "ivar_getOffset")
			36	+	object_getClass = purego.Dlsym(objc, "object_getClass")
33		)	37		)
34			38
35		// ID is an opaque pointer to some Objective-C object	39		// ID is an opaque pointer to some Objective-C object

@@ -152,17 +156,54 @@ func (c Class) AddMethod(name SEL, imp _IMP, types string) bool {
152		return byte(ret) != 0	156		return byte(ret) != 0
153		}	157		}
154			158
155	-	// Register registers a class that was allocated using objc_allocateClassPair.	159	+	// AddIvar adds a new instance variable to a class.
			160	+	// It may only be called after AllocateClassPair and before Register.
			161	+	// Adding an instance variable to an existing class is not supported.
			162	+	// The class must not be a metaclass. Adding an instance variable to a metaclass is not supported.
			163	+	// It takes the instance of the type of the Ivar and a string representing the type.
			164	+	func (c Class) AddIvar(name string, ty interface{}, types string) bool {
			165	+	n := strings.CString(name)
			166	+	t := strings.CString(types)
			167	+	typeOf := reflect.TypeOf(ty)
			168	+	size := typeOf.Size()
			169	+	alignment := uint8(math.Log2(float64(typeOf.Align())))
			170	+	ret, _, _ := purego.SyscallN(class_addIvar, uintptr(c), uintptr(unsafe.Pointer(n)), size, uintptr(alignment), uintptr(unsafe.Pointer(t)))
			171	+	runtime.KeepAlive(n)
			172	+	runtime.KeepAlive(t)
			173	+	return byte(ret) != 0
			174	+	}
			175	+
			176	+	// InstanceVariable returns an Ivar data structure containing information about the instance variable specified by name.
			177	+	func (c Class) InstanceVariable(name string) Ivar {
			178	+	n := strings.CString(name)
			179	+	ret, _, _ := purego.SyscallN(class_getInstanceVariable, uintptr(c), uintptr(unsafe.Pointer(n)))
			180	+	runtime.KeepAlive(n)
			181	+	return Ivar(ret)
			182	+	}
			183	+
			184	+	// Register registers a class that was allocated using AllocateClassPair.
156		// It can now be used to make objects by sending it either alloc and init or new.	185		// It can now be used to make objects by sending it either alloc and init or new.
157		func (c Class) Register() {	186		func (c Class) Register() {
158		purego.SyscallN(objc_registerClassPair, uintptr(c))	187		purego.SyscallN(objc_registerClassPair, uintptr(c))
159		}	188		}
160			189
			190	+	// Ivar an opaque type that represents an instance variable.
			191	+	type Ivar uintptr
			192	+
			193	+	// Offset returns the offset of an instance variable that can be used to assign and read the Ivar's value.
			194	+	//
			195	+	// For instance variables of type id or other object types, call Ivar and SetIvar instead
			196	+	// of using this offset to access the instance variable data directly.
			197	+	func (i Ivar) Offset() uintptr {
			198	+	ret, _, _ := purego.SyscallN(ivar_getOffset, uintptr(i))
			199	+	return ret
			200	+	}
			201	+
161		// _IMP is unexported so that the only way to make this type is by providing a Go function and casting	202		// _IMP is unexported so that the only way to make this type is by providing a Go function and casting
162		// it with the IMP function	203		// it with the IMP function
163		type _IMP uintptr	204		type _IMP uintptr
164			205
165	-	// IMP takes a Go function that takes (id, SEL) as its first two arguments. It returns an _IMP function	206	+	// IMP takes a Go function that takes (ID, SEL) as its first two arguments. It returns an _IMP function
166		// pointer that can be called by Objective-C code. The function pointer is never deallocated.	207		// pointer that can be called by Objective-C code. The function pointer is never deallocated.
167		func IMP(fn interface{}) _IMP {	208		func IMP(fn interface{}) _IMP {
168		// this is only here so that it is easier to port C code to Go.	209		// this is only here so that it is easier to port C code to Go.

A objc/objc_runtime_darwin_test.go +61 -0

@@ -0,0 +1,61 @@
	1	+	// SPDX-License-Identifier: Apache-2.0
	2	+	// SPDX-FileCopyrightText: 2022 The Ebitengine Authors
	3	+
	4	+	package objc
	5	+
	6	+	import (
	7	+	"fmt"
	8	+	"runtime"
	9	+	"unsafe"
	10	+
	11	+	"github.com/ebitengine/purego"
	12	+	)
	13	+
	14	+	func init() {
	15	+	// this is here so that the program doesn't crash with:
	16	+	// fatal error: schedule: in cgo
	17	+	// this can be removed after purego#12 is solved.
	18	+	// this is due to moving goroutines to different threads while in C code
	19	+	runtime.LockOSThread()
	20	+	}
	21	+
	22	+	func ExampleAllocateClassPair() {
	23	+	var class = AllocateClassPair(GetClass("NSObject\x00"), "FooObject\x00", 0)
	24	+	class.AddMethod(RegisterName("run\x00"), IMP(func(self ID, _cmd SEL) {
	25	+	fmt.Println("Hello World!")
	26	+	}), "v@:\x00")
	27	+	class.Register()
	28	+
	29	+	var fooObject = ID(class).Send(RegisterName("new\x00"))
	30	+	fooObject.Send(RegisterName("run\x00"))
	31	+	// Output: Hello World!
	32	+	}
	33	+
	34	+	func ExampleClass_AddIvar() {
	35	+	var class = AllocateClassPair(GetClass("NSObject\x00"), "BarObject\x00", 0)
	36	+	class.AddIvar("bar\x00", int(0), "q\x00")
	37	+	var barOffset = class.InstanceVariable("bar\x00").Offset()
	38	+	class.AddMethod(RegisterName("bar\x00"), IMP(func(self ID, _cmd SEL) int {
	39	+	return (int)(unsafe.Pointer(uintptr(unsafe.Pointer(self)) + barOffset))
	40	+	}), "q@:\x00")
	41	+	class.AddMethod(RegisterName("setBar:\x00"), IMP(func(self ID, _cmd SEL, bar int) {
	42	+	(int)(unsafe.Pointer(uintptr(unsafe.Pointer(self)) + barOffset)) = bar
	43	+	}), "v@:q\x00")
	44	+	class.Register()
	45	+
	46	+	var barObject = ID(class).Send(RegisterName("new\x00"))
	47	+	barObject.Send(RegisterName("setBar:\x00"), 123)
	48	+	var bar = int(barObject.Send(RegisterName("bar\x00")))
	49	+	fmt.Println(bar)
	50	+	// Output: 123
	51	+	}
	52	+
	53	+	func ExampleIMP() {
	54	+	imp := IMP(func(self ID, _cmd SEL) {
	55	+	fmt.Println("IMP:", self, _cmd)
	56	+	})
	57	+
	58	+	purego.SyscallN(uintptr(imp), 105, 567)
	59	+
	60	+	// Output: IMP: 105 567
	61	+	}

@@ -0,0 +1,61 @@
	1	+	// SPDX-License-Identifier: Apache-2.0
	2	+	// SPDX-FileCopyrightText: 2022 The Ebitengine Authors
	3	+
	4	+	package objc
	5	+
	6	+	import (
	7	+	"fmt"
	8	+	"runtime"
	9	+	"unsafe"
	10	+
	11	+	"github.com/ebitengine/purego"
	12	+	)
	13	+
	14	+	func init() {
	15	+	// this is here so that the program doesn't crash with:
	16	+	// fatal error: schedule: in cgo
	17	+	// this can be removed after purego#12 is solved.
	18	+	// this is due to moving goroutines to different threads while in C code
	19	+	runtime.LockOSThread()
	20	+	}
	21	+
	22	+	func ExampleAllocateClassPair() {
	23	+	var class = AllocateClassPair(GetClass("NSObject\x00"), "FooObject\x00", 0)
	24	+	class.AddMethod(RegisterName("run\x00"), IMP(func(self ID, _cmd SEL) {
	25	+	fmt.Println("Hello World!")
	26	+	}), "v@:\x00")
	27	+	class.Register()
	28	+
	29	+	var fooObject = ID(class).Send(RegisterName("new\x00"))
	30	+	fooObject.Send(RegisterName("run\x00"))
	31	+	// Output: Hello World!
	32	+	}
	33	+
	34	+	func ExampleClass_AddIvar() {
	35	+	var class = AllocateClassPair(GetClass("NSObject\x00"), "BarObject\x00", 0)
	36	+	class.AddIvar("bar\x00", int(0), "q\x00")
	37	+	var barOffset = class.InstanceVariable("bar\x00").Offset()
	38	+	class.AddMethod(RegisterName("bar\x00"), IMP(func(self ID, _cmd SEL) int {
	39	+	return (int)(unsafe.Pointer(uintptr(unsafe.Pointer(self)) + barOffset))
	40	+	}), "q@:\x00")
	41	+	class.AddMethod(RegisterName("setBar:\x00"), IMP(func(self ID, _cmd SEL, bar int) {
	42	+	(int)(unsafe.Pointer(uintptr(unsafe.Pointer(self)) + barOffset)) = bar
	43	+	}), "v@:q\x00")
	44	+	class.Register()
	45	+
	46	+	var barObject = ID(class).Send(RegisterName("new\x00"))
	47	+	barObject.Send(RegisterName("setBar:\x00"), 123)
	48	+	var bar = int(barObject.Send(RegisterName("bar\x00")))
	49	+	fmt.Println(bar)
	50	+	// Output: 123
	51	+	}
	52	+
	53	+	func ExampleIMP() {
	54	+	imp := IMP(func(self ID, _cmd SEL) {
	55	+	fmt.Println("IMP:", self, _cmd)
	56	+	})
	57	+
	58	+	purego.SyscallN(uintptr(imp), 105, 567)
	59	+
	60	+	// Output: IMP: 105 567
	61	+	}

M syscall_darwin.go +14 -1


@@ -116,7 +116,20 @@ func callbackWrap(a *callbackArgs) {
116	116		}
117	117		ret := fn.Call(args)
118	118		if len(ret) > 0 {
119		-	a.result = uintptr(ret[0].Uint())
	119	+	switch k := ret[0].Kind(); k {
	120	+	case reflect.Uint, reflect.Uint64, reflect.Uint32, reflect.Uint16, reflect.Uint8, reflect.Uintptr:
	121	+	a.result = uintptr(ret[0].Uint())
	122	+	case reflect.Int, reflect.Int64, reflect.Int32, reflect.Int16, reflect.Int8:
	123	+	a.result = uintptr(ret[0].Int())
	124	+	case reflect.Bool:
	125	+	if ret[0].Bool() {
	126	+	a.result = 1
	127	+	} else {
	128	+	a.result = 0
	129	+	}
	130	+	default:
	131	+	panic("purego: unsupported kind: " + k.String())
	132	+	}
120	133		}
121	134		}
122	135


@@ -116,7 +116,20 @@ func callbackWrap(a *callbackArgs) {
116		}	116		}
117		ret := fn.Call(args)	117		ret := fn.Call(args)
118		if len(ret) > 0 {	118		if len(ret) > 0 {
119	-	a.result = uintptr(ret[0].Uint())	119	+	switch k := ret[0].Kind(); k {
			120	+	case reflect.Uint, reflect.Uint64, reflect.Uint32, reflect.Uint16, reflect.Uint8, reflect.Uintptr:
			121	+	a.result = uintptr(ret[0].Uint())
			122	+	case reflect.Int, reflect.Int64, reflect.Int32, reflect.Int16, reflect.Int8:
			123	+	a.result = uintptr(ret[0].Int())
			124	+	case reflect.Bool:
			125	+	if ret[0].Bool() {
			126	+	a.result = 1
			127	+	} else {
			128	+	a.result = 0
			129	+	}
			130	+	default:
			131	+	panic("purego: unsupported kind: " + k.String())
			132	+	}
120		}	133		}
121		}	134		}
122			135