From 9e8541553244ee04b5b39e9c060b7fa9e5b44e07 Mon Sep 17 00:00:00 2001
From: Cristian Maglie <c.maglie@bug.st>
Date: Wed, 31 Dec 2014 00:27:28 +0100
Subject: [PATCH] Removed cgo dependency from windows implementation

---
 serial_windows.go  | 82 ++++++++++++++--------------------------------
 syscall_windows.go | 12 ++++++-
 2 files changed, 36 insertions(+), 58 deletions(-)

diff --git a/serial_windows.go b/serial_windows.go
index 2360792..11eebad 100644
--- a/serial_windows.go
+++ b/serial_windows.go
@@ -14,77 +14,45 @@ package serial // import "go.bug.st/serial"
 // Arduino Playground article on serial communication with Windows API:
 // http://playground.arduino.cc/Interfacing/CPPWindows
 
-#include <stdlib.h>
-#include <windows.h>
-
-//HANDLE invalid = INVALID_HANDLE_VALUE;
-
-HKEY INVALID_PORT_LIST = 0;
-
-HKEY openPortList() {
-	HKEY handle;
-	LPCSTR lpSubKey = "HARDWARE\\DEVICEMAP\\SERIALCOMM\\";
-	DWORD res = RegOpenKeyExA(HKEY_LOCAL_MACHINE, lpSubKey, 0, KEY_READ, &handle);
-	if (res != ERROR_SUCCESS)
-		return INVALID_PORT_LIST;
-	else
-		return handle;
-}
-
-int countPortList(HKEY handle) {
-	int count = 0;
-	for (;;) {
-		char name[256];
-		DWORD nameSize = 256;
-		DWORD res = RegEnumValueA(handle, count, name, &nameSize, NULL, NULL, NULL, NULL);
-		if (res != ERROR_SUCCESS)
-			return count;
-		count++;
-	}
-}
-
-char *getInPortList(HKEY handle, int i) {
-	byte *data = (byte *) malloc(256);
-	DWORD dataSize = 256;
-	char name[256];
-	DWORD nameSize = 256;
-	DWORD res = RegEnumValueA(handle, i, name, &nameSize, NULL, NULL, data, &dataSize);
-	if (res != ERROR_SUCCESS) {
-		free(data);
-		return NULL;
-	}
-	return data;
-}
-
-void closePortList(HKEY handle) {
-	CloseHandle(handle);
-}
-
 */
-import "C"
+
 import "syscall"
-import "unsafe"
 
 // opaque type that implements SerialPort interface for Windows
 type windowsSerialPort struct {
 	Handle syscall.Handle
 }
 
+//sys RegEnumValue(key syscall.Handle, index uint32, name *uint16, nameLen *uint32, reserved *uint32, class *uint16, value *uint16, valueLen *uint32) (regerrno error) = advapi32.RegEnumValueW
+
 func GetPortsList() ([]string, error) {
-	portList := C.openPortList()
-	if portList == C.INVALID_PORT_LIST {
+	subKey, err := syscall.UTF16PtrFromString("HARDWARE\\DEVICEMAP\\SERIALCOMM\\")
+	if err != nil {
 		return nil, &SerialPortError{code: ERROR_ENUMERATING_PORTS}
 	}
-	n := C.countPortList(portList)
 
-	list := make([]string, n)
-	for i := range list {
-		portName := C.getInPortList(portList, C.int(i))
-		list[i] = C.GoString(portName)
-		C.free(unsafe.Pointer(portName))
+	var h syscall.Handle
+	if syscall.RegOpenKeyEx(syscall.HKEY_LOCAL_MACHINE, subKey, 0, syscall.KEY_READ, &h) != nil {
+		return nil, &SerialPortError{code: ERROR_ENUMERATING_PORTS}
+	}
+	defer syscall.RegCloseKey(h)
+
+	var valuesCount uint32
+	if syscall.RegQueryInfoKey(h, nil, nil, nil, nil, nil, nil, &valuesCount, nil, nil, nil, nil) != nil {
+		return nil, &SerialPortError{code: ERROR_ENUMERATING_PORTS}
 	}
 
-	C.closePortList(portList)
+	list := make([]string, valuesCount)
+	for i := range list {
+		var data [1024]uint16
+		dataSize := uint32(len(data))
+		var name [1024]uint16
+		nameSize := uint32(len(name))
+		if RegEnumValue(h, uint32(i), &name[0], &nameSize, nil, nil, &data[0], &dataSize) != nil {
+			return nil, &SerialPortError{code: ERROR_ENUMERATING_PORTS}
+		}
+		list[i] = syscall.UTF16ToString(data[:])
+	}
 	return list, nil
 }
 
diff --git a/syscall_windows.go b/syscall_windows.go
index c0065c2..f868cb8 100644
--- a/syscall_windows.go
+++ b/syscall_windows.go
@@ -1,4 +1,4 @@
-// go build mksyscall_windows.go && ./mksyscall_windows native_windows.go
+// go build mksyscall_windows.go && ./mksyscall_windows serial_windows.go
 // MACHINE GENERATED BY THE COMMAND ABOVE; DO NOT EDIT
 
 package serial
@@ -7,13 +7,23 @@ import "unsafe"
 import "syscall"
 
 var (
+	modadvapi32 = syscall.NewLazyDLL("advapi32.dll")
 	modkernel32 = syscall.NewLazyDLL("kernel32.dll")
 
+	procRegEnumValueW   = modadvapi32.NewProc("RegEnumValueW")
 	procGetCommState    = modkernel32.NewProc("GetCommState")
 	procSetCommState    = modkernel32.NewProc("SetCommState")
 	procSetCommTimeouts = modkernel32.NewProc("SetCommTimeouts")
 )
 
+func RegEnumValue(key syscall.Handle, index uint32, name *uint16, nameLen *uint32, reserved *uint32, class *uint16, value *uint16, valueLen *uint32) (regerrno error) {
+	r0, _, _ := syscall.Syscall9(procRegEnumValueW.Addr(), 8, uintptr(key), uintptr(index), uintptr(unsafe.Pointer(name)), uintptr(unsafe.Pointer(nameLen)), uintptr(unsafe.Pointer(reserved)), uintptr(unsafe.Pointer(class)), uintptr(unsafe.Pointer(value)), uintptr(unsafe.Pointer(valueLen)), 0)
+	if r0 != 0 {
+		regerrno = syscall.Errno(r0)
+	}
+	return
+}
+
 func GetCommState(handle syscall.Handle, dcb *DCB) (err error) {
 	r1, _, e1 := syscall.Syscall(procGetCommState.Addr(), 2, uintptr(handle), uintptr(unsafe.Pointer(dcb)), 0)
 	if r1 == 0 {