Fix library loading from Unicode paths on Windows

Author: pejovica

substratevm/src/com.oracle.svm.core.windows/src/com/oracle/svm/core/windows/WindowsNativeLibrarySupport.java

@@ -26,7 +26,6 @@
 
 import java.io.FileDescriptor;
 
-import org.graalvm.nativeimage.c.type.CCharPointer;
 import org.graalvm.nativeimage.c.type.CTypeConversion;
 import org.graalvm.nativeimage.c.type.CTypeConversion.CCharPointerHolder;
 import org.graalvm.word.PointerBase;
@@ -42,10 +41,12 @@
 import com.oracle.svm.core.jdk.NativeLibrarySupport;
 import com.oracle.svm.core.jdk.PlatformNativeLibrarySupport;
 import com.oracle.svm.core.log.Log;
+import com.oracle.svm.core.windows.WindowsUtils.WCharPointerHolder;
 import com.oracle.svm.core.windows.headers.FileAPI;
 import com.oracle.svm.core.windows.headers.LibLoaderAPI;
 import com.oracle.svm.core.windows.headers.WinBase.HMODULE;
 import com.oracle.svm.core.windows.headers.WinSock;
+import com.oracle.svm.core.windows.headers.WindowsLibC.WCharPointer;
 
 import jdk.graal.compiler.word.Word;
 
@@ -166,13 +167,9 @@ private boolean doLoad() {
                 return true;
             }
             assert dlhandle.isNull();
-            try (CCharPointerHolder dllPathPin = CTypeConversion.toCString(canonicalIdentifier)) {
-                CCharPointer dllPathPtr = dllPathPin.get();
-                /*
-                 * WinBase.SetDllDirectoryA(dllpathPtr); CCharPointerHolder pathPin =
-                 * CTypeConversion.toCString(path); CCharPointer pathPtr = pathPin.get();
-                 */
-                dlhandle = LibLoaderAPI.LoadLibraryA(dllPathPtr);
+            try (WCharPointerHolder dllPathPin = WindowsUtils.toWideCString(canonicalIdentifier)) {
+                WCharPointer dllPathPtr = dllPathPin.get();
+                dlhandle = LibLoaderAPI.LoadLibraryW(dllPathPtr);
             }
             return dlhandle.isNonNull();
         }

substratevm/src/com.oracle.svm.core.windows/src/com/oracle/svm/core/windows/WindowsUtils.java

@@ -47,12 +47,14 @@
 import com.oracle.svm.core.annotate.TargetClass;
 import com.oracle.svm.core.c.function.CEntryPointActions;
 import com.oracle.svm.core.graal.stackvalue.UnsafeStackValue;
+import com.oracle.svm.core.handles.PrimitiveArrayView;
 import com.oracle.svm.core.util.BasedOnJDKFile;
 import com.oracle.svm.core.windows.headers.FileAPI;
 import com.oracle.svm.core.windows.headers.LibLoaderAPI;
 import com.oracle.svm.core.windows.headers.WinBase;
 import com.oracle.svm.core.windows.headers.WinBase.HANDLE;
 import com.oracle.svm.core.windows.headers.WinBase.HMODULE;
+import com.oracle.svm.core.windows.headers.WindowsLibC.WCharPointer;
 
 import jdk.graal.compiler.word.Word;
 
@@ -232,4 +234,43 @@ private static HMODULE getDLLHandle(CCharPointer dllName) {
         }
         return dllHandle;
     }
+
+    /**
+     * Returns a holder that exposes a {@linkplain WCharPointer WCharPointer} to a null-terminated
+     * wide C string created from the given Java String.
+     */
+    public static WCharPointerHolder toWideCString(String javaString) {
+        assert javaString != null;
+        return new WCharPointerHolder(javaString);
+    }
+
+    /**
+     * Holder for a null-terminated wide C string. The exposed {@linkplain WCharPointer
+     * WCharPointer} remains valid only while this holder is open.
+     */
+    public static final class WCharPointerHolder implements AutoCloseable {
+        private final PrimitiveArrayView wideCString;
+
+        private WCharPointerHolder(String javaString) {
+            /*
+             * Windows wide C strings use UTF-16LE, matching Java char[]. So we add a trailing NUL
+             * and then reinterpret the Java char[] as a wchar_t[].
+             */
+            int length = javaString.length();
+            char[] chars = new char[length + 1]; // trailing NUL
+            javaString.getChars(0, length, chars, 0);
+            wideCString = PrimitiveArrayView.createForReading(chars);
+        }
+
+        /** Returns the pointer to the null-terminated wide C string. */
+        public WCharPointer get() {
+            return wideCString.addressOfArrayElement(0);
+        }
+
+        /** Invalidates the pointer. */
+        @Override
+        public void close() {
+            wideCString.close();
+        }
+    }
 }

substratevm/src/com.oracle.svm.core.windows/src/com/oracle/svm/core/windows/headers/LibLoaderAPI.java

@@ -75,9 +75,9 @@ public class LibLoaderAPI {
 
     /** Loads the specified module into the address space of the calling process. */
     @CFunction(transition = NO_TRANSITION)
-    public static native HMODULE LoadLibraryA(CCharPointer lpLibFileName);
+    public static native HMODULE LoadLibraryW(WCharPointer lpLibFileName);
 
     /** Loads the specified module into the address space of the calling process. */
     @CFunction(transition = NO_TRANSITION)
-    public static native HMODULE LoadLibraryExA(CCharPointer lpLibFileName, HANDLE hFile, int dwFlags);
+    public static native HMODULE LoadLibraryExW(WCharPointer lpLibFileName, HANDLE hFile, int dwFlags);
 }

substratevm/src/com.oracle.svm.truffle.nfi.windows/src/com/oracle/svm/truffle/nfi/windows/WindowsTruffleNFIFeature.java

@@ -24,7 +24,6 @@
  */
 package com.oracle.svm.truffle.nfi.windows;
 
-import jdk.graal.compiler.word.Word;
 import org.graalvm.nativeimage.ImageSingletons;
 import org.graalvm.nativeimage.Platform;
 import org.graalvm.nativeimage.c.type.CCharPointer;
@@ -44,6 +43,8 @@
 import com.oracle.truffle.api.CompilerDirectives;
 import com.oracle.truffle.api.exception.AbstractTruffleException;
 
+import jdk.graal.compiler.word.Word;
+
 public final class WindowsTruffleNFIFeature implements InternalFeature {
 
     @Override
@@ -75,8 +76,8 @@ protected CCharPointer strdupImpl(CCharPointer src) {
     protected long loadLibraryImpl(long nativeContext, String name, int flags) {
         String dllPath = name;
         HMODULE dlhandle;
-        try (CTypeConversion.CCharPointerHolder dllpathPin = CTypeConversion.toCString(dllPath)) {
-            dlhandle = LibLoaderAPI.LoadLibraryExA(dllpathPin.get(), Word.nullPointer(), flags);
+        try (WindowsUtils.WCharPointerHolder dllpathPin = WindowsUtils.toWideCString(dllPath)) {
+            dlhandle = LibLoaderAPI.LoadLibraryExW(dllpathPin.get(), Word.nullPointer(), flags);
         }
         if (dlhandle.isNull()) {
             CompilerDirectives.transferToInterpreter();