windows: add console ConPTY API

Add Windows ConPTY API, specifically CreatePseudoConsole, ClosePseudoConsole, and ResizePseudoConsole.

See https://devblogs.microsoft.com/commandline/windows-command-line-introducing-the-windows-pseudo-console-conpty/
See https://learn.microsoft.com/en-us/windows/console/creating-a-pseudoconsole-session
Updates #62708

Change-Id: I433c4d9d8716dd75fa44291ab0cf6ef3c5f6a913
GitHub-Last-Rev: 21cda7e
GitHub-Pull-Request: #175
Reviewed-on: https://go-review.googlesource.com/c/sys/+/528915
Run-TryBot: Quim Muntal <quimmuntal@gmail.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Bryan Mills <bcmills@google.com>
Reviewed-by: Quim Muntal <quimmuntal@gmail.com>
Reviewed-by: Than McIntosh <thanm@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

windows/syscall_windows.go

@@ -297,12 +297,15 @@ func NewCallbackCDecl(fn interface{}) uintptr {
 //sys	RegNotifyChangeKeyValue(key Handle, watchSubtree bool, notifyFilter uint32, event Handle, asynchronous bool) (regerrno error) = advapi32.RegNotifyChangeKeyValue
 //sys	GetCurrentProcessId() (pid uint32) = kernel32.GetCurrentProcessId
 //sys	ProcessIdToSessionId(pid uint32, sessionid *uint32) (err error) = kernel32.ProcessIdToSessionId
+//sys	ClosePseudoConsole(console Handle) = kernel32.ClosePseudoConsole
+//sys	createPseudoConsole(size uint32, in Handle, out Handle, flags uint32, pconsole *Handle) (hr error) = kernel32.CreatePseudoConsole
 //sys	GetConsoleMode(console Handle, mode *uint32) (err error) = kernel32.GetConsoleMode
 //sys	SetConsoleMode(console Handle, mode uint32) (err error) = kernel32.SetConsoleMode
 //sys	GetConsoleScreenBufferInfo(console Handle, info *ConsoleScreenBufferInfo) (err error) = kernel32.GetConsoleScreenBufferInfo
 //sys	setConsoleCursorPosition(console Handle, position uint32) (err error) = kernel32.SetConsoleCursorPosition
 //sys	WriteConsole(console Handle, buf *uint16, towrite uint32, written *uint32, reserved *byte) (err error) = kernel32.WriteConsoleW
 //sys	ReadConsole(console Handle, buf *uint16, toread uint32, read *uint32, inputControl *byte) (err error) = kernel32.ReadConsoleW
+//sys	resizePseudoConsole(pconsole Handle, size uint32) (hr error) = kernel32.ResizePseudoConsole
 //sys	CreateToolhelp32Snapshot(flags uint32, processId uint32) (handle Handle, err error) [failretval==InvalidHandle] = kernel32.CreateToolhelp32Snapshot
 //sys	Module32First(snapshot Handle, moduleEntry *ModuleEntry32) (err error) = kernel32.Module32FirstW
 //sys	Module32Next(snapshot Handle, moduleEntry *ModuleEntry32) (err error) = kernel32.Module32NextW
@@ -1813,3 +1816,17 @@ type PSAPI_WORKING_SET_EX_INFORMATION struct {
 	// A PSAPI_WORKING_SET_EX_BLOCK union that indicates the attributes of the page at VirtualAddress.
 	VirtualAttributes PSAPI_WORKING_SET_EX_BLOCK
 }
+
+// CreatePseudoConsole creates a windows pseudo console.
+func CreatePseudoConsole(size Coord, in Handle, out Handle, flags uint32, pconsole *Handle) error {
+	// We need this wrapper to manually cast Coord to uint32. The autogenerated wrappers only
+	// accept arguments that can be casted to uintptr, and Coord can't.
+	return createPseudoConsole(*((*uint32)(unsafe.Pointer(&size))), in, out, flags, pconsole)
+}
+
+// ResizePseudoConsole resizes the internal buffers of the pseudo console to the width and height specified in `size`.
+func ResizePseudoConsole(pconsole Handle, size Coord) error {
+	// We need this wrapper to manually cast Coord to uint32. The autogenerated wrappers only
+	// accept arguments that can be casted to uintptr, and Coord can't.
+	return resizePseudoConsole(pconsole, *((*uint32)(unsafe.Pointer(&size))))
+}

windows/types_windows.go

@@ -247,6 +247,7 @@ const (
 	PROC_THREAD_ATTRIBUTE_MITIGATION_POLICY = 0x00020007
 	PROC_THREAD_ATTRIBUTE_UMS_THREAD        = 0x00030006
 	PROC_THREAD_ATTRIBUTE_PROTECTION_LEVEL  = 0x0002000b
+	PROC_THREAD_ATTRIBUTE_PSEUDOCONSOLE     = 0x00020016
 )
 
 const (
@@ -2139,6 +2140,12 @@ const (
 	ENABLE_LVB_GRID_WORLDWIDE          = 0x10
 )
 
+// Pseudo console related constants used for the flags parameter to
+// CreatePseudoConsole. See: https://learn.microsoft.com/en-us/windows/console/createpseudoconsole
+const (
+	PSEUDOCONSOLE_INHERIT_CURSOR = 0x1
+)
+
 type Coord struct {
 	X int16
 	Y int16