all: replace unsafe slice operations with unsafe.Slice

Signed-off-by: Elias Naur <mail@eliasnaur.com>

app/internal/windows/windows.go

@@ -619,12 +619,12 @@ func GlobalFree(h syscall.Handle) {
 	_GlobalFree.Call(uintptr(h))
 }
 
-func GlobalLock(h syscall.Handle) (uintptr, error) {
+func GlobalLock(h syscall.Handle) (unsafe.Pointer, error) {
 	r, _, err := _GlobalLock.Call(uintptr(h))
 	if r == 0 {
-		return 0, fmt.Errorf("GlobalLock: %v", err)
+		return nil, fmt.Errorf("GlobalLock: %v", err)
 	}
-	return r, nil
+	return unsafe.Pointer(r), nil
 }
 
 func GlobalUnlock(h syscall.Handle) {

app/os_android.go

@@ -126,7 +126,6 @@ import (
 	"math"
 	"os"
 	"path/filepath"
-	"reflect"
 	"runtime"
 	"runtime/debug"
 	"sync"
@@ -1252,11 +1251,7 @@ func goString(env *C.JNIEnv, str C.jstring) string {
 	}
 	strlen := C.jni_GetStringLength(env, C.jstring(str))
 	chars := C.jni_GetStringChars(env, C.jstring(str))
-	var utf16Chars []uint16
+	utf16Chars := unsafe.Slice((*uint16)(unsafe.Pointer(chars)), strlen)
-	hdr := (*reflect.SliceHeader)(unsafe.Pointer(&utf16Chars))
-	hdr.Data = uintptr(unsafe.Pointer(chars))
-	hdr.Cap = int(strlen)
-	hdr.Len = int(strlen)
 	utf8 := utf16.Decode(utf16Chars)
 	return string(utf8)
 }

app/os_windows.go

@@ -6,7 +6,6 @@ import (
 	"errors"
 	"fmt"
 	"image"
-	"reflect"
 	"runtime"
 	"sort"
 	"strings"
@@ -690,11 +689,7 @@ func (w *window) writeClipboard(s string) error {
 		windows.GlobalFree(mem)
 		return err
 	}
-	var u16v []uint16
+	u16v := unsafe.Slice((*uint16)(ptr), len(u16))
-	hdr := (*reflect.SliceHeader)(unsafe.Pointer(&u16v))
-	hdr.Data = ptr
-	hdr.Cap = len(u16)
-	hdr.Len = len(u16)
 	copy(u16v, u16)
 	windows.GlobalUnlock(mem)
 	if err := windows.SetClipboardData(windows.CF_UNICODETEXT, mem); err != nil {

gpu/gpu.go

@@ -1172,7 +1172,7 @@ func newUniformBuffer(b driver.Device, uniformBlock interface{}) *uniformBuffer
 	// Determine the size of the uniforms structure, *uniforms.
 	size := ref.Elem().Type().Size()
 	// Map the uniforms structure as a byte slice.
-	ptr := (*[1 << 30]byte)(unsafe.Pointer(ref.Pointer()))[:size:size]
+	ptr := unsafe.Slice((*byte)(unsafe.Pointer(ref.Pointer())), size)
 	ubuf, err := b.NewBuffer(driver.BufferBindingUniforms, len(ptr))
 	if err != nil {
 		panic(err)

gpu/internal/d3d11/d3d11_windows.go

@@ -7,7 +7,6 @@ import (
 	"fmt"
 	"image"
 	"math"
-	"reflect"
 	"unsafe"
 
 	"golang.org/x/sys/windows"
@@ -850,10 +849,5 @@ func toBlendFactor(f driver.BlendFactor) (uint32, uint32) {
 
 // sliceOf returns a slice from a (native) pointer.
 func sliceOf(ptr uintptr, cap int) []byte {
-	var data []byte
+	return unsafe.Slice((*byte)(unsafe.Pointer(ptr)), cap)
-	h := (*reflect.SliceHeader)(unsafe.Pointer(&data))
-	h.Data = ptr
-	h.Cap = cap
-	h.Len = cap
-	return data
 }

internal/byteslice/byteslice.go

@@ -11,14 +11,9 @@ import (
 
 // Struct returns a byte slice view of a struct.
 func Struct(s interface{}) []byte {
-	v := reflect.ValueOf(s).Elem()
+	v := reflect.ValueOf(s)
-	sz := int(v.Type().Size())
+	sz := int(v.Elem().Type().Size())
-	var res []byte
+	return unsafe.Slice((*byte)(unsafe.Pointer(v.Pointer())), sz)
-	h := (*reflect.SliceHeader)(unsafe.Pointer(&res))
-	h.Data = uintptr(unsafe.Pointer(v.UnsafeAddr()))
-	h.Cap = sz
-	h.Len = sz
-	return res
 }
 
 // Uint32 returns a byte slice view of a uint32 slice.
@@ -28,7 +23,7 @@ func Uint32(s []uint32) []byte {
 		return nil
 	}
 	blen := n * int(unsafe.Sizeof(s[0]))
-	return (*[1 << 30]byte)(unsafe.Pointer(&s[0]))[:blen:blen]
+	return unsafe.Slice((*byte)(unsafe.Pointer(&s[0])), blen)
 }
 
 // Slice returns a byte slice view of a slice.
@@ -36,10 +31,6 @@ func Slice(s interface{}) []byte {
 	v := reflect.ValueOf(s)
 	first := v.Index(0)
 	sz := int(first.Type().Size())
-	var res []byte
+	res := unsafe.Slice((*byte)(unsafe.Pointer(v.Pointer())), sz*v.Cap())
-	h := (*reflect.SliceHeader)(unsafe.Pointer(&res))
+	return res[:sz*v.Len()]
-	h.Data = first.UnsafeAddr()
-	h.Cap = v.Cap() * sz
-	h.Len = v.Len() * sz
-	return res
 }