std: win: Don't use GetUserProfileDirectoryW on UWP

Author: chouquette

src/libstd/sys/windows/c.rs

@@ -143,7 +143,6 @@ pub const WSAECONNREFUSED: c_int = 10061;
 
 pub const MAX_PROTOCOL_CHAIN: DWORD = 7;
 
-pub const TOKEN_READ: DWORD = 0x20008;
 pub const MAXIMUM_REPARSE_DATA_BUFFER_SIZE: usize = 16 * 1024;
 pub const FSCTL_GET_REPARSE_POINT: DWORD = 0x900a8;
 pub const IO_REPARSE_TAG_SYMLINK: DWORD = 0xa000000c;
@@ -660,10 +659,19 @@ cfg_if::cfg_if! {
 if #[cfg(not(target_vendor = "uwp"))] {
     pub const HANDLE_FLAG_INHERIT: DWORD = 0x00000001;
 
+    pub const TOKEN_READ: DWORD = 0x20008;
+
     extern "system" {
         #[link_name = "SystemFunction036"]
         pub fn RtlGenRandom(RandomBuffer: *mut u8, RandomBufferLength: ULONG) -> BOOLEAN;
 
+        // Allowed but unused by UWP
+        pub fn OpenProcessToken(ProcessHandle: HANDLE,
+                                DesiredAccess: DWORD,
+                                TokenHandle: *mut HANDLE) -> BOOL;
+        pub fn GetUserProfileDirectoryW(hToken: HANDLE,
+                                        lpProfileDir: LPWSTR,
+                                        lpcchSize: *mut DWORD) -> BOOL;
         pub fn SetHandleInformation(hObject: HANDLE,
                                     dwMask: DWORD,
                                     dwFlags: DWORD) -> BOOL;
@@ -752,9 +760,6 @@ extern "system" {
     pub fn GetCommandLineW() -> *mut LPCWSTR;
     pub fn GetTempPathW(nBufferLength: DWORD,
                         lpBuffer: LPCWSTR) -> DWORD;
-    pub fn OpenProcessToken(ProcessHandle: HANDLE,
-                            DesiredAccess: DWORD,
-                            TokenHandle: *mut HANDLE) -> BOOL;
     pub fn GetCurrentProcess() -> HANDLE;
     pub fn GetCurrentThread() -> HANDLE;
     pub fn GetStdHandle(which: DWORD) -> HANDLE;
@@ -779,9 +784,6 @@ extern "system" {
     pub fn SwitchToThread() -> BOOL;
     pub fn Sleep(dwMilliseconds: DWORD);
     pub fn GetProcessId(handle: HANDLE) -> DWORD;
-    pub fn GetUserProfileDirectoryW(hToken: HANDLE,
-                                    lpProfileDir: LPWSTR,
-                                    lpcchSize: *mut DWORD) -> BOOL;
     pub fn CopyFileExW(lpExistingFileName: LPCWSTR,
                        lpNewFileName: LPCWSTR,
                        lpProgressRoutine: LPPROGRESS_ROUTINE,

src/libstd/sys/windows/os.rs

@@ -13,7 +13,6 @@ use crate::path::{self, PathBuf};
 use crate::ptr;
 use crate::slice;
 use crate::sys::{c, cvt};
-use crate::sys::handle::Handle;
 
 use super::to_u16s;
 
@@ -284,10 +283,11 @@ pub fn temp_dir() -> PathBuf {
     }, super::os2path).unwrap()
 }
 
-pub fn home_dir() -> Option<PathBuf> {
-    crate::env::var_os("HOME").or_else(|| {
-        crate::env::var_os("USERPROFILE")
-    }).map(PathBuf::from).or_else(|| unsafe {
+#[cfg(not(target_vendor = "uwp"))]
+fn home_dir_crt() -> Option<PathBuf> {
+    unsafe {
+        use crate::sys::handle::Handle;
+
         let me = c::GetCurrentProcess();
         let mut token = ptr::null_mut();
         if c::OpenProcessToken(me, c::TOKEN_READ, &mut token) == 0 {
@@ -301,7 +301,18 @@ pub fn home_dir() -> Option<PathBuf> {
                 _ => sz - 1, // sz includes the null terminator
             }
         }, super::os2path).ok()
-    })
+    }
+}
+
+#[cfg(target_vendor = "uwp")]
+fn home_dir_crt() -> Option<PathBuf> {
+    None
+}
+
+pub fn home_dir() -> Option<PathBuf> {
+    crate::env::var_os("HOME").or_else(|| {
+        crate::env::var_os("USERPROFILE")
+    }).map(PathBuf::from).or_else(|| home_dir_crt())
 }
 
 pub fn exit(code: i32) -> ! {