1 files changed, 223 insertions, 0 deletions
diff --git a/vendor/github.com/ebitengine/purego/syscall_sysv.go b/vendor/github.com/ebitengine/purego/syscall_sysv.go
new file mode 100644
index 0000000..cce171c
--- /dev/null
+++ b/vendor/github.com/ebitengine/purego/syscall_sysv.go
@@ -0,0 +1,223 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2022 The Ebitengine Authors
+
+//go:build darwin || freebsd || (linux && (amd64 || arm64))
+
+package purego
+
+import (
+	"reflect"
+	"runtime"
+	"sync"
+	"unsafe"
+)
+
+var syscall15XABI0 uintptr
+
+//go:nosplit
+func syscall_syscall15X(fn, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12, a13, a14, a15 uintptr) (r1, r2, err uintptr) {
+	args := syscall15Args{
+		fn, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12, a13, a14, a15,
+		a1, a2, a3, a4, a5, a6, a7, a8,
+		0,
+	}
+	runtime_cgocall(syscall15XABI0, unsafe.Pointer(&args))
+	return args.a1, args.a2, 0
+}
+
+// NewCallback converts a Go function to a function pointer conforming to the C calling convention.
+// This is useful when interoperating with C code requiring callbacks. The argument is expected to be a
+// function with zero or one uintptr-sized result. The function must not have arguments with size larger than the size
+// of uintptr. Only a limited number of callbacks may be created in a single Go process, and any memory allocated
+// for these callbacks is never released. At least 2000 callbacks can always be created. Although this function
+// provides similar functionality to windows.NewCallback it is distinct.
+func NewCallback(fn interface{}) uintptr {
+	ty := reflect.TypeOf(fn)
+	for i := 0; i < ty.NumIn(); i++ {
+		in := ty.In(i)
+		if !in.AssignableTo(reflect.TypeOf(CDecl{})) {
+			continue
+		}
+		if i != 0 {
+			panic("purego: CDecl must be the first argument")
+		}
+	}
+	return compileCallback(fn)
+}
+
+// maxCb is the maximum number of callbacks
+// only increase this if you have added more to the callbackasm function
+const maxCB = 2000
+
+var cbs struct {
+	lock  sync.Mutex
+	numFn int                  // the number of functions currently in cbs.funcs
+	funcs [maxCB]reflect.Value // the saved callbacks
+}
+
+type callbackArgs struct {
+	index uintptr
+	// args points to the argument block.
+	//
+	// The structure of the arguments goes
+	// float registers followed by the
+	// integer registers followed by the stack.
+	//
+	// This variable is treated as a continuous
+	// block of memory containing all of the arguments
+	// for this callback.
+	args unsafe.Pointer
+	// Below are out-args from callbackWrap
+	result uintptr
+}
+
+func compileCallback(fn interface{}) uintptr {
+	val := reflect.ValueOf(fn)
+	if val.Kind() != reflect.Func {
+		panic("purego: the type must be a function but was not")
+	}
+	if val.IsNil() {
+		panic("purego: function must not be nil")
+	}
+	ty := val.Type()
+	for i := 0; i < ty.NumIn(); i++ {
+		in := ty.In(i)
+		switch in.Kind() {
+		case reflect.Struct:
+			if i == 0 && in.AssignableTo(reflect.TypeOf(CDecl{})) {
+				continue
+			}
+			fallthrough
+		case reflect.Interface, reflect.Func, reflect.Slice,
+			reflect.Chan, reflect.Complex64, reflect.Complex128,
+			reflect.String, reflect.Map, reflect.Invalid:
+			panic("purego: unsupported argument type: " + in.Kind().String())
+		}
+	}
+output:
+	switch {
+	case ty.NumOut() == 1:
+		switch ty.Out(0).Kind() {
+		case reflect.Pointer, reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64,
+			reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr,
+			reflect.Bool, reflect.UnsafePointer:
+			break output
+		}
+		panic("purego: unsupported return type: " + ty.String())
+	case ty.NumOut() > 1:
+		panic("purego: callbacks can only have one return")
+	}
+	cbs.lock.Lock()
+	defer cbs.lock.Unlock()
+	if cbs.numFn >= maxCB {
+		panic("purego: the maximum number of callbacks has been reached")
+	}
+	cbs.funcs[cbs.numFn] = val
+	cbs.numFn++
+	return callbackasmAddr(cbs.numFn - 1)
+}
+
+const ptrSize = unsafe.Sizeof((*int)(nil))
+
+const callbackMaxFrame = 64 * ptrSize
+
+// callbackasm is implemented in zcallback_GOOS_GOARCH.s
+//
+//go:linkname __callbackasm callbackasm
+var __callbackasm byte
+var callbackasmABI0 = uintptr(unsafe.Pointer(&__callbackasm))
+
+// callbackWrap_call allows the calling of the ABIInternal wrapper
+// which is required for runtime.cgocallback without the
+// <ABIInternal> tag which is only allowed in the runtime.
+// This closure is used inside sys_darwin_GOARCH.s
+var callbackWrap_call = callbackWrap
+
+// callbackWrap is called by assembly code which determines which Go function to call.
+// This function takes the arguments and passes them to the Go function and returns the result.
+func callbackWrap(a *callbackArgs) {
+	cbs.lock.Lock()
+	fn := cbs.funcs[a.index]
+	cbs.lock.Unlock()
+	fnType := fn.Type()
+	args := make([]reflect.Value, fnType.NumIn())
+	frame := (*[callbackMaxFrame]uintptr)(a.args)
+	var floatsN int // floatsN represents the number of float arguments processed
+	var intsN int   // intsN represents the number of integer arguments processed
+	// stack points to the index into frame of the current stack element.
+	// The stack begins after the float and integer registers.
+	stack := numOfIntegerRegisters() + numOfFloats
+	for i := range args {
+		var pos int
+		switch fnType.In(i).Kind() {
+		case reflect.Float32, reflect.Float64:
+			if floatsN >= numOfFloats {
+				pos = stack
+				stack++
+			} else {
+				pos = floatsN
+			}
+			floatsN++
+		case reflect.Struct:
+			// This is the CDecl field
+			args[i] = reflect.Zero(fnType.In(i))
+			continue
+		default:
+
+			if intsN >= numOfIntegerRegisters() {
+				pos = stack
+				stack++
+			} else {
+				// the integers begin after the floats in frame
+				pos = intsN + numOfFloats
+			}
+			intsN++
+		}
+		args[i] = reflect.NewAt(fnType.In(i), unsafe.Pointer(&frame[pos])).Elem()
+	}
+	ret := fn.Call(args)
+	if len(ret) > 0 {
+		switch k := ret[0].Kind(); k {
+		case reflect.Uint, reflect.Uint64, reflect.Uint32, reflect.Uint16, reflect.Uint8, reflect.Uintptr:
+			a.result = uintptr(ret[0].Uint())
+		case reflect.Int, reflect.Int64, reflect.Int32, reflect.Int16, reflect.Int8:
+			a.result = uintptr(ret[0].Int())
+		case reflect.Bool:
+			if ret[0].Bool() {
+				a.result = 1
+			} else {
+				a.result = 0
+			}
+		case reflect.Pointer:
+			a.result = ret[0].Pointer()
+		case reflect.UnsafePointer:
+			a.result = ret[0].Pointer()
+		default:
+			panic("purego: unsupported kind: " + k.String())
+		}
+	}
+}
+
+// callbackasmAddr returns address of runtime.callbackasm
+// function adjusted by i.
+// On x86 and amd64, runtime.callbackasm is a series of CALL instructions,
+// and we want callback to arrive at
+// correspondent call instruction instead of start of
+// runtime.callbackasm.
+// On ARM, runtime.callbackasm is a series of mov and branch instructions.
+// R12 is loaded with the callback index. Each entry is two instructions,
+// hence 8 bytes.
+func callbackasmAddr(i int) uintptr {
+	var entrySize int
+	switch runtime.GOARCH {
+	default:
+		panic("purego: unsupported architecture")
+	case "386", "amd64":
+		entrySize = 5
+	case "arm", "arm64":
+		// On ARM and ARM64, each entry is a MOV instruction
+		// followed by a branch instruction
+		entrySize = 8
+	}
+	return callbackasmABI0 + uintptr(i*entrySize)
+}