tools/vsymlink: use the win32 api to update the system environment

cmd/tools/vsymlink.v

@@ -1,6 +1,11 @@
 import os
 import v.pref
 
+const (
+	hkey_local_machine = voidptr(0x80000002)
+	hwnd_broadcast = voidptr(0xffff)
+)
+
 fn main(){
 	$if windows {
 		setup_symlink_on_windows()
@@ -34,6 +39,7 @@ fn setup_symlink_on_unix(){
 }
 
 fn setup_symlink_on_windows(){
+	$if windows {
 		vexe := pref.vexe_path()
 		// NB: Putting $vdir directly into PATH will also result in
 		// make.bat being global, which is NOT what we want.
@@ -41,7 +47,7 @@ fn setup_symlink_on_windows(){
 		// Instead, we create a small launcher v.bat, in a new local
 		// folder .symlink/ . That .symlink/ folder can then be put
 		// in PATH without poluting it with anything else - just a
-	// `v` command will be available, simillar to unix.
+		// `v` command will be available, similar to unix.
 		//
 		// Creating a real NTFS symlink to the real executable was also
 		// tried, but then os.real_path( os.executable() ) returns the
@@ -50,40 +56,124 @@ fn setup_symlink_on_windows(){
 		vdir := os.real_path(os.dir(vexe))
 		vsymlinkdir := os.join_path(vdir, '.symlink')
 		vsymlinkbat := os.join_path(vsymlinkdir, 'v.bat')
+		if os.exists(vsymlinkbat) {
+			print('Batch script $vsymlinkbat already exists, checking system %PATH%...')
+		}
+		else {
 			os.rmdir_all(vsymlinkdir)
 			os.mkdir_all(vsymlinkdir)
 			os.write_file(vsymlinkbat, '@echo off\n${vexe} %*')
-	if !os.exists( vsymlinkbat ) {
+			if !os.exists(vsymlinkbat) {
 				eprintln('Could not create $vsymlinkbat')
 				exit(1)
 			}
-	println('Created $vsymlinkbat .')
-	current_paths := os.getenv('PATH').split(';').map(it.trim('/\\'))
-	if vsymlinkdir in current_paths {
-		println('$vsymlinkdir is already on your PATH')
-		println('Try running `v version`')
-		exit(0)
+			else {
+				print('Created $vsymlinkbat, checking system %PATH%...')
 			}
-	// put vsymlinkdir first, prevent duplicates:
+		}
+
+		reg_sys_env_handle  := get_reg_sys_env_handle() or {
+			warn_and_exit(err)
+			return
+		}
+		defer {
+			C.RegCloseKey(reg_sys_env_handle)
+		}
+
+		sys_env_path := get_reg_value(reg_sys_env_handle, 'Path') or {
+			warn_and_exit(err)
+			return
+		}
+
+		current_sys_paths := sys_env_path.split(os.path_delimiter).map(it.trim('/$os.path_separator'))
 		mut new_paths := [ vsymlinkdir ]
-	for p in current_paths {
+		for p in current_sys_paths {
 			if p !in new_paths {
 				new_paths << p
 			}
 		}
-	//
-	change_path_cmd := 'setx /M PATH "' + new_paths.join(';') +'"'
-	println('Changing global PATH with:')
-	println(change_path_cmd)
-	res := os.system(change_path_cmd)
-	if res == 0 {
-		println('')
-		println('$vsymlinkdir has been prepended to PATH.')
-		println('Try running `v version`.')
-		exit(0)
-	} else {
-		println('Could not run `setx`, probably you are not an administrator.')
-		println('`v symlink` should be launched with admin privileges.')
-		exit(1)
+
+		new_sys_env_path := new_paths.join(';')
+
+		if new_sys_env_path == sys_env_path {
+			println('configured.')
+		}
+		else {
+			print('not configured.\nSetting system %PATH%...')
+			set_reg_value(reg_sys_env_handle, 'Path', new_sys_env_path) or {
+				warn_and_exit(err)
+				return
+			}
+			println('done.')
+		}
+
+		print('Letting running process know to update their Environment...')
+		send_setting_change_msg('Environment') or {
+			eprintln('\n' + err)
+			warn_and_exit('You might need to run this again to have `v` in your %PATH%')
+			return
+		}
+
+		println('finished.\n\nNote: restart your shell/IDE to load the new %PATH%.')
+		println('\nAfter restarting your shell/IDE, give `v version` a try in another dir!')
 	}
 }
+
+fn warn_and_exit(err string) {
+	eprintln(err)
+	exit(1)
+}
+
+// get the system environment registry handle
+fn get_reg_sys_env_handle() ?voidptr {
+	$if windows {
+		// open the registry key
+		reg_key_path   := 'SYSTEM\\CurrentControlSet\\Control\\Session Manager\\Environment'
+		reg_env_key    := voidptr(0) // or HKEY (HANDLE)
+		if C.RegOpenKeyEx(hkey_local_machine, reg_key_path.to_wide(), 0, 1 | 2, &reg_env_key) != 0 {
+			return error('Could not open "$reg_key_path" in the registry')
+		}
+
+		return reg_env_key
+	}
+	return error('not on windows')
+}
+
+// get a value from a given $key
+fn get_reg_value(reg_env_key voidptr, key string) ?string {
+	$if windows {
+		// query the value (shortcut the sizing step)
+		reg_value_size := 4095 // this is the max length (not for the registry, but for the system %PATH%)
+		mut reg_value  := &u16(malloc(reg_value_size))
+		if C.RegQueryValueEx(reg_env_key, key.to_wide(), 0, 0, reg_value, &reg_value_size) != 0 {
+			return error('Unable to get registry value for "$key", are you running as an Administrator?')
+		}
+
+		return string_from_wide(reg_value)
+	}
+	return error('not on windows')
+}
+
+// sets the value for the given $key to the given  $value
+fn set_reg_value(reg_key voidptr, key string, value string) ?bool {
+	$if windows {
+		if C.RegSetValueEx(reg_key, key.to_wide(), 0, 1, value.to_wide(), 4095) != 0 {
+			return error('Unable to set registry value for "$key", are you running as an Administrator?')
+		}
+
+		return true
+	}
+	return error('not on windows')
+}
+
+// broadcasts a message to all listening windows (explorer.exe in particular)
+// letting them know that the system environment has changed and should be reloaded
+fn send_setting_change_msg(message_data string) ?bool {
+	$if windows {
+		if C.SendMessageTimeout(hwnd_broadcast, 0x001A, 0, message_data.to_wide(), 2, 5000, 0) == 0 {
+			return error('Could not broadcast WM_SETTINGCHANGE')
+		}
+		return true
+	}
+	return error('not on windows')
+}

vlib/builtin/cfns.c.v

@@ -202,6 +202,10 @@ fn C.SetHandleInformation(hObject voidptr, dwMask u32, dw_flags u32) bool
 fn C.ExpandEnvironmentStringsW(lpSrc &u16, lpDst &u16, nSize u32) u32
 
 
+fn C.SendMessageTimeout() u32
+fn C.SendMessageTimeoutW(hWnd voidptr, Msg u32, wParam &u16, lParam &u32, fuFlags u32, uTimeout u32, lpdwResult &u64) u32
+
+
 fn C.CreateProcessW(lpApplicationName &u16, lpCommandLine &u16, lpProcessAttributes voidptr, lpThreadAttributes voidptr, bInheritHandles bool, dwCreationFlags u32, lpEnvironment voidptr, lpCurrentDirectory &u16, lpStartupInfo voidptr, lpProcessInformation voidptr) bool
 
 
@@ -211,18 +215,21 @@ fn C.ReadFile(hFile voidptr, lpBuffer voidptr, nNumberOfBytesToRead u32, lpNumbe
 fn C.GetFileAttributesW(lpFileName byteptr) u32
 
 
+fn C.RegQueryValueEx() voidptr
 fn C.RegQueryValueExW(hKey voidptr, lpValueName &u16, lp_reserved &u32, lpType &u32, lpData byteptr, lpcbData &u32) int
 
 
+fn C.RegOpenKeyEx() voidptr
 fn C.RegOpenKeyExW(hKey voidptr, lpSubKey &u16, ulOptions u32, samDesired u32, phkResult voidptr) int
 
 
+fn C.RegSetValueEx() voidptr
+fn C.RegSetValueExW(hKey voidptr, lpValueName &u16, Reserved u32, dwType u32, lpData byteptr, lpcbData u32) int
+
+
 fn C.RegCloseKey()
 
 
-fn C.RegQueryValueEx() voidptr
-
-
 fn C.RemoveDirectory() int
 
 
@@ -338,7 +345,6 @@ fn C.CloseHandle()
 fn C.GetExitCodeProcess()
 
 
-fn C.RegOpenKeyEx() voidptr
 
 
 fn C.GetTickCount() i64

vlib/v/builder/msvc.v

@@ -118,7 +118,7 @@ fn find_windows_kit_root(host_arch string) ?WindowsKit {
 			shared_include_path: kit_include_highest + '\\shared'
 		}
 	}
-	return error('Host OS does not support funding a windows kit')
+	return error('Host OS does not support finding a windows kit')
 }
 
 struct VsInstallation {
@@ -129,7 +129,7 @@ struct VsInstallation {
 
 fn find_vs(vswhere_dir, host_arch string) ?VsInstallation {
 	$if !windows {
-		return error('Host OS does not support finding a Vs installation')
+		return error('Host OS does not support finding a Visual Studio installation')
 	}
 	// Emily:
 	// VSWhere is guaranteed to be installed at this location now