Build from paths containing spaces on Windows

Editor/Core/ShortPath.cs

@@ -0,0 +1,87 @@
+using System.Runtime.InteropServices;
+using System.Text;
+using UnityEngine;
+
+namespace SplashEdit.EditorCode
+{
+    /// <summary>
+    /// Resolves filesystem paths for safe use as a make working directory.
+    /// GNU make and the psyqo makefiles derive their own root via
+    /// $(abspath $(lastword $(MAKEFILE_LIST))) resolved against make's CWD, and neither
+    /// handles a space in that path correctly. On Windows we can usually dodge the
+    /// problem with the legacy 8.3 short path; everywhere else a space is fatal.
+    /// </summary>
+    public static class ShortPath
+    {
+        [DllImport("kernel32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
+        private static extern uint GetShortPathNameW(string lpszLongPath, StringBuilder lpszShortPath, uint cchBuffer);
+
+        /// <summary>
+        /// Resolves <paramref name="dir"/> into a path make can safely use as its working
+        /// directory. On Windows, a path containing spaces is converted to its 8.3 short
+        /// path. Returns false with a descriptive <paramref name="error"/> if the path
+        /// contains a space and cannot be made safe (non-Windows, or 8.3 names disabled).
+        /// </summary>
+        public static bool TryResolveForMake(string dir, out string resolvedDir, out string error)
+        {
+            if (Application.platform != RuntimePlatform.WindowsEditor)
+            {
+                if (dir.IndexOf(' ') >= 0)
+                {
+                    resolvedDir = null;
+                    error = SpacesInPathError(dir);
+                    return false;
+                }
+
+                resolvedDir = dir;
+                error = null;
+                return true;
+            }
+
+            if (dir.IndexOf(' ') < 0)
+            {
+                resolvedDir = dir;
+                error = null;
+                return true;
+            }
+
+            string shortPath = GetShortPath(dir);
+            if (string.IsNullOrEmpty(shortPath) || shortPath.IndexOf(' ') >= 0)
+            {
+                resolvedDir = null;
+                error = SpacesInPathError(dir) +
+                    " On Windows this can usually be fixed by enabling 8.3 short names on the " +
+                    "drive (run `fsutil 8dot3name set <drive>: 0` as Administrator - this only " +
+                    "affects files created afterwards, so the project may need to be recreated " +
+                    "at its current path once enabled).";
+                return false;
+            }
+
+            resolvedDir = shortPath;
+            error = null;
+            return true;
+        }
+
+        private static string SpacesInPathError(string dir) =>
+            $"The project path contains spaces (\"{dir}\"), which GNU make and the psyqo " +
+            "makefiles cannot handle. Move the project to a path without spaces.";
+
+        private static string GetShortPath(string longPath)
+        {
+            var buffer = new StringBuilder(260);
+            uint length = GetShortPathNameW(longPath, buffer, (uint)buffer.Capacity);
+            if (length == 0)
+                return null;
+
+            if (length > buffer.Capacity)
+            {
+                buffer = new StringBuilder((int)length);
+                length = GetShortPathNameW(longPath, buffer, (uint)buffer.Capacity);
+                if (length == 0)
+                    return null;
+            }
+
+            return buffer.ToString();
+        }
+    }
+}

Editor/Core/SplashControlPanel.cs

@@ -1907,14 +1907,20 @@ private async Task<Dictionary<string, byte[]>> CompileLuaAsync(Dictionary<LuaFil
         /// </summary>
         private async Task<bool> BuildLuacPsxAsync(string luacDir)
         {
+            if (!ShortPath.TryResolveForMake(luacDir, out string luacWorkDir, out string pathError))
+            {
+                Log(pathError, LogType.Error);
+                return false;
+            }
+
             int jobCount = Math.Max(1, SystemInfo.processorCount - 1);
             string makeCmd = $"make -j{jobCount}";
 
             var psi = new ProcessStartInfo
             {
                 FileName = Application.platform == RuntimePlatform.WindowsEditor ? "cmd.exe" : "/bin/bash",
-                Arguments = WrapCommandForMacOS(luacDir, makeCmd),
-                WorkingDirectory = luacDir,
+                Arguments = WrapCommandForMacOS(luacWorkDir, makeCmd),
+                WorkingDirectory = luacWorkDir,
                 RedirectStandardOutput = true,
                 RedirectStandardError = true,
                 UseShellExecute = false,
@@ -1993,6 +1999,12 @@ private async Task<bool> CompileNativeAsync()
                 return false;
             }
 
+            if (!ShortPath.TryResolveForMake(nativeDir, out string nativeWorkDir, out string pathError))
+            {
+                Log(pathError, LogType.Error);
+                return false;
+            }
+
             string buildArg = SplashSettings.Mode == BuildMode.Debug ? "BUILD=Debug" : "";
 
             if (SplashSettings.Target == BuildTarget.ISO)
@@ -2029,8 +2041,8 @@ private async Task<bool> CompileNativeAsync()
             var psi = new ProcessStartInfo
             {
                 FileName = Application.platform == RuntimePlatform.WindowsEditor ? "cmd.exe" : "/bin/bash",
-                Arguments = WrapCommandForMacOS(nativeDir, makeCmd),
-                WorkingDirectory = nativeDir,
+                Arguments = WrapCommandForMacOS(nativeWorkDir, makeCmd),
+                WorkingDirectory = nativeWorkDir,
                 RedirectStandardOutput = true,
                 RedirectStandardError = true,
                 UseShellExecute = false,