subsonic-tui/vendor/github.com/ebitengine/purego/syscall_sysv.go
Sagi Dayan a3923cf42c initial commit
Signed-off-by: Sagi Dayan <sagidayan@gmail.com>
2024-03-29 17:56:39 +03:00

209 lines
6.6 KiB
Go

// 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
type syscall15Args struct {
fn, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12, a13, a14, a15 uintptr
f1, f2, f3, f4, f5, f6, f7, f8 uintptr
r1, r2, err 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,
r1, r2, err,
}
runtime_cgocall(syscall15XABI0, unsafe.Pointer(&args))
return args.r1, args.r2, args.err
}
// 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 {
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, 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++
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)
}