WindowsSdk: Fix every registry key being opened with KEY_WOW64_32KEY

Now, an options struct is used to determine whether or not KEY_WOW64_32KEY should be set when opening a registry key.

Author: squeek502

lib/std/zig/WindowsSdk.zig

@@ -23,7 +23,7 @@ pub fn find(allocator: std.mem.Allocator) error{ OutOfMemory, NotFound, PathTooL
     if (builtin.os.tag != .windows) return error.NotFound;
 
     //note(dimenus): If this key doesn't exist, neither the Win 8 SDK nor the Win 10 SDK is installed
-    const roots_key = RegistryWtf8.openKey(windows.HKEY_LOCAL_MACHINE, windows_kits_reg_key) catch |err| switch (err) {
+    const roots_key = RegistryWtf8.openKey(windows.HKEY_LOCAL_MACHINE, windows_kits_reg_key, .{ .wow64_32 = true }) catch |err| switch (err) {
         error.KeyNotFound => return error.NotFound,
     };
     defer roots_key.closeKey();
@@ -137,11 +137,17 @@ fn iterateAndFilterByVersion(
     return dirs.toOwnedSlice();
 }
 
+const OpenOptions = struct {
+    /// Sets the KEY_WOW64_32KEY access flag.
+    /// https://learn.microsoft.com/en-us/windows/win32/winprog64/accessing-an-alternate-registry-view
+    wow64_32: bool = false,
+};
+
 const RegistryWtf8 = struct {
     key: windows.HKEY,
 
     /// Assert that `key` is valid WTF-8 string
-    pub fn openKey(hkey: windows.HKEY, key: []const u8) error{KeyNotFound}!RegistryWtf8 {
+    pub fn openKey(hkey: windows.HKEY, key: []const u8, options: OpenOptions) error{KeyNotFound}!RegistryWtf8 {
         const key_wtf16le: [:0]const u16 = key_wtf16le: {
             var key_wtf16le_buf: [RegistryWtf16Le.key_name_max_len]u16 = undefined;
             const key_wtf16le_len: usize = std.unicode.wtf8ToWtf16Le(key_wtf16le_buf[0..], key) catch |err| switch (err) {
@@ -151,7 +157,7 @@ const RegistryWtf8 = struct {
             break :key_wtf16le key_wtf16le_buf[0..key_wtf16le_len :0];
         };
 
-        const registry_wtf16le = try RegistryWtf16Le.openKey(hkey, key_wtf16le);
+        const registry_wtf16le = try RegistryWtf16Le.openKey(hkey, key_wtf16le, options);
         return .{ .key = registry_wtf16le.key };
     }
 
@@ -239,15 +245,17 @@ const RegistryWtf16Le = struct {
     pub const value_name_max_len = 16_383;
 
     /// Under HKEY_LOCAL_MACHINE with flags:
-    /// KEY_QUERY_VALUE, KEY_WOW64_32KEY, and KEY_ENUMERATE_SUB_KEYS.
+    /// KEY_QUERY_VALUE, KEY_ENUMERATE_SUB_KEYS, optionally KEY_WOW64_32KEY.
     /// After finishing work, call `closeKey`.
-    fn openKey(hkey: windows.HKEY, key_wtf16le: [:0]const u16) error{KeyNotFound}!RegistryWtf16Le {
+    fn openKey(hkey: windows.HKEY, key_wtf16le: [:0]const u16, options: OpenOptions) error{KeyNotFound}!RegistryWtf16Le {
         var key: windows.HKEY = undefined;
+        var access: windows.REGSAM = windows.KEY_QUERY_VALUE | windows.KEY_ENUMERATE_SUB_KEYS;
+        if (options.wow64_32) access |= windows.KEY_WOW64_32KEY;
         const return_code_int: windows.HRESULT = windows.advapi32.RegOpenKeyExW(
             hkey,
             key_wtf16le,
             0,
-            windows.KEY_QUERY_VALUE | windows.KEY_WOW64_32KEY | windows.KEY_ENUMERATE_SUB_KEYS,
+            access,
             &key,
         );
         const return_code: windows.Win32Error = @enumFromInt(return_code_int);
@@ -484,13 +492,14 @@ pub const Installation = struct {
         version_key_name: []const u8,
     ) error{ OutOfMemory, InstallationNotFound, PathTooLong, VersionTooLong }!Installation {
         var key_name_buf: [RegistryWtf16Le.key_name_max_len]u8 = undefined;
-        const key = key: for ([_][]const u8{ "\\Wow6432Node", "" }) |wow6432node| {
+        const key_name = std.fmt.bufPrint(
+            &key_name_buf,
+            "SOFTWARE\\Microsoft\\Microsoft SDKs\\Windows\\{s}",
+            .{version_key_name},
+        ) catch unreachable;
+        const key = key: for ([_]bool{ true, false }) |wow6432node| {
             for ([_]windows.HKEY{ windows.HKEY_LOCAL_MACHINE, windows.HKEY_CURRENT_USER }) |hkey| {
-                break :key RegistryWtf8.openKey(hkey, std.fmt.bufPrint(
-                    &key_name_buf,
-                    "SOFTWARE{s}\\Microsoft\\Microsoft SDKs\\Windows\\{s}",
-                    .{ wow6432node, version_key_name },
-                ) catch unreachable) catch |err| switch (err) {
+                break :key RegistryWtf8.openKey(hkey, key_name, .{ .wow64_32 = wow6432node }) catch |err| switch (err) {
                     error.KeyNotFound => return error.InstallationNotFound,
                 };
             }
@@ -563,6 +572,7 @@ pub const Installation = struct {
         const options_key = RegistryWtf8.openKey(
             windows.HKEY_LOCAL_MACHINE,
             reg_query_as_wtf8,
+            .{ .wow64_32 = true },
         ) catch |err| switch (err) {
             error.KeyNotFound => return false,
         };
@@ -589,7 +599,7 @@ pub const Installation = struct {
 const MsvcLibDir = struct {
     fn findInstancesDirViaSetup(allocator: std.mem.Allocator) error{ OutOfMemory, PathNotFound }!std.fs.Dir {
         const vs_setup_key_path = "SOFTWARE\\Microsoft\\VisualStudio\\Setup";
-        const vs_setup_key = RegistryWtf8.openKey(windows.HKEY_LOCAL_MACHINE, vs_setup_key_path) catch |err| switch (err) {
+        const vs_setup_key = RegistryWtf8.openKey(windows.HKEY_LOCAL_MACHINE, vs_setup_key_path, .{}) catch |err| switch (err) {
             error.KeyNotFound => return error.PathNotFound,
         };
         defer vs_setup_key.closeKey();
@@ -614,7 +624,7 @@ const MsvcLibDir = struct {
 
     fn findInstancesDirViaCLSID(allocator: std.mem.Allocator) error{ OutOfMemory, PathNotFound }!std.fs.Dir {
         const setup_configuration_clsid = "{177f0c4a-1cd3-4de7-a32c-71dbbb9fa36d}";
-        const setup_config_key = RegistryWtf8.openKey(windows.HKEY_CLASSES_ROOT, "CLSID\\" ++ setup_configuration_clsid) catch |err| switch (err) {
+        const setup_config_key = RegistryWtf8.openKey(windows.HKEY_CLASSES_ROOT, "CLSID\\" ++ setup_configuration_clsid, .{}) catch |err| switch (err) {
             error.KeyNotFound => return error.PathNotFound,
         };
         defer setup_config_key.closeKey();
@@ -941,7 +951,7 @@ const MsvcLibDir = struct {
                 }
             }
 
-            const vs7_key = RegistryWtf8.openKey(windows.HKEY_LOCAL_MACHINE, "SOFTWARE\\Microsoft\\VisualStudio\\SxS\\VS7") catch return error.PathNotFound;
+            const vs7_key = RegistryWtf8.openKey(windows.HKEY_LOCAL_MACHINE, "SOFTWARE\\Microsoft\\VisualStudio\\SxS\\VS7", .{ .wow64_32 = true }) catch return error.PathNotFound;
             defer vs7_key.closeKey();
             try_vs7_key: {
                 const path_maybe_with_trailing_slash = vs7_key.getString(allocator, "", "14.0") catch |err| switch (err) {