runtime: fix parameter checking in syscall.NewCallback

I have made mistake while converting it to Go (CL 132820043).
Added test as penance for my sin.

LGTM=rsc
R=golang-codereviews, bradfitz, rsc
CC=golang-codereviews
https://golang.org/cl/136560043

diff --git a/src/runtime/syscall_windows.go b/src/runtime/syscall_windows.go
index 959c675f4f240a7e029f7da2b5d49d73356e81ca..efbcab510dad875dc2ee8decd33b96304a5ff43f 100644 (file)
--- a/src/runtime/syscall_windows.go
+++ b/src/runtime/syscall_windows.go
@@ -53,7 +53,7 @@ func compileCallback(fn eface, cleanstack bool) (code uintptr) {
        }
        argsize := uintptr(0)
        for _, t := range (*[1024](*_type))(unsafe.Pointer(&ft.in[0]))[:len(ft.in)] {
-               if (*t).size != uintptrSize {
+               if (*t).size > uintptrSize {
                        panic("compilecallback: input parameter size is wrong")
                }
                argsize += uintptrSize

diff --git a/src/runtime/syscall_windows_test.go b/src/runtime/syscall_windows_test.go
index fabf935d8e246da95f24993bd1a215ec995dc47b..a828512188a89e0c15e73152d0a983ed267261a6 100644 (file)
--- a/src/runtime/syscall_windows_test.go
+++ b/src/runtime/syscall_windows_test.go
@@ -449,3 +449,42 @@ func TestStdcallAndCDeclCallbacks(t *testing.T) {
                }
        }
 }
+
+func TestRegisterClass(t *testing.T) {
+       kernel32 := GetDLL(t, "kernel32.dll")
+       user32 := GetDLL(t, "user32.dll")
+       mh, _, _ := kernel32.Proc("GetModuleHandleW").Call(0)
+       cb := syscall.NewCallback(func(hwnd syscall.Handle, msg uint32, wparam, lparam uintptr) (rc uintptr) {
+               t.Fatal("callback should never get called")
+               return 0
+       })
+       type Wndclassex struct {
+               Size       uint32
+               Style      uint32
+               WndProc    uintptr
+               ClsExtra   int32
+               WndExtra   int32
+               Instance   syscall.Handle
+               Icon       syscall.Handle
+               Cursor     syscall.Handle
+               Background syscall.Handle
+               MenuName   *uint16
+               ClassName  *uint16
+               IconSm     syscall.Handle
+       }
+       name := syscall.StringToUTF16Ptr("test_window")
+       wc := Wndclassex{
+               WndProc:   cb,
+               Instance:  syscall.Handle(mh),
+               ClassName: name,
+       }
+       wc.Size = uint32(unsafe.Sizeof(wc))
+       a, _, err := user32.Proc("RegisterClassExW").Call(uintptr(unsafe.Pointer(&wc)))
+       if a == 0 {
+               t.Fatalf("RegisterClassEx failed: %v", err)
+       }
+       r, _, err := user32.Proc("UnregisterClassW").Call(uintptr(unsafe.Pointer(name)), 0)
+       if r == 0 {
+               t.Fatalf("UnregisterClass failed: %v", err)
+       }
+}