Improve Windows interop (#2022)

Interop/Runtime/src/main/kotlin/kotlinx/cinterop/Utils.kt

@@ -375,16 +375,16 @@ fun List<String>.toCStringArray(autofreeScope: AutofreeScope): CPointer<CPointer
 fun Array<String>.toCStringArray(autofreeScope: AutofreeScope): CPointer<CPointerVar<ByteVar>> =
         autofreeScope.allocArrayOf(this.map { it.cstr.getPointer(autofreeScope) })
 
-val String.wcstr: CValues<ShortVar>
+val String.wcstr: CValues<UShortVar>
     get() {
         val chars = CharArray(this.length, { i -> this.get(i)})
-        return object : CValues<ShortVar>() {
+        return object : CValues<UShortVar>() {
             override val size get() = 2 * (chars.size + 1)
 
-            override fun getPointer(scope: AutofreeScope): CPointer<ShortVar> {
-                val result = scope.allocArray<ShortVar>(chars.size + 1)
+            override fun getPointer(scope: AutofreeScope): CPointer<UShortVar> {
+                val result = scope.allocArray<UShortVar>(chars.size + 1)
                 nativeMemUtils.putCharArray(chars, result.pointed, chars.size)
-                result[chars.size] = 0.toShort()
+                result[chars.size] = 0u
                 return result
             }
         }

Interop/Runtime/src/native/kotlin/kotlinx/cinterop/NativeMem.kt

@@ -129,6 +129,21 @@ fun CPointer<ShortVar>.toKString(): String {
     return String(bytes)
 }
 
+fun CPointer<UShortVar>.toKString(): String {
+    val nativeBytes = this
+
+    var length = 0
+    while (nativeBytes[length] != 0.toUShort()) {
+        ++length
+    }
+    val bytes = CharArray(length)
+    var index = 0
+    while (index < length) {
+        bytes[index] = nativeBytes[index].toShort().toChar()
+        ++index
+    }
+    return String(bytes)
+}
 
 @SymbolName("Kotlin_interop_malloc")
 private external fun malloc(size: Long, align: Int): NativePtr

Interop/StubGenerator/src/main/kotlin/org/jetbrains/kotlin/native/interop/gen/jvm/StubGenerator.kt

@@ -323,7 +323,8 @@ class StubGenerator(
     }
 
     // We take this approach as generic 'const short*' shall not be used as String.
-    fun representCFunctionParameterAsWString(type: Type)= type.isAliasOf(platformWStringTypes)
+    fun representCFunctionParameterAsWString(function: FunctionDecl, type: Type) = type.isAliasOf(platformWStringTypes)
+            && !noStringConversion.contains(function.name)
 
     private fun getArrayLength(type: ArrayType): Long {
         val unwrappedElementType = type.elemType.unwrapTypedefs()
@@ -629,7 +630,7 @@ class StubGenerator(
                     kotlinParameters.add(parameterName to KotlinTypes.string.makeNullable())
                     bodyGenerator.pushMemScoped()
                     "$parameterName?.cstr?.getPointer(memScope)"
-                } else if (representCFunctionParameterAsWString(parameter.type)) {
+                } else if (representCFunctionParameterAsWString(func, parameter.type)) {
                     kotlinParameters.add(parameterName to KotlinTypes.string.makeNullable())
                     bodyGenerator.pushMemScoped()
                     "$parameterName?.wcstr?.getPointer(memScope)"

platformLibs/src/platform/mingw/windows.def

@@ -4,5 +4,5 @@ headers = wtypes.h minwindef.h windows.h commctrl.h dwmapi.h shlobj.h shlwapi.h
 compilerOpts = -DUNICODE -DWINVER=0x0601 -D_WIN32_WINNT=0x0601 -DWINAPI_FAMILY=3 -DOEMRESOURCE \
     -Wno-incompatible-pointer-types -Wno-deprecated-declarations
 linkerOpts = -lcomctl32 -lcrypt32 -lshlwapi -lshell32 -limm32 -lusp10 -lwininet -lgdi32 -luser32 -lkernel32
-noStringConversion = LoadCursorA LoadBitmapA
+noStringConversion = LoadCursorA LoadBitmapA LoadIconA LoadImageA LoadCursorW LoadBitmapW LoadIconW LoadImageW
 depends = posix

samples/win32/src/main/kotlin/MessageBox.kt

@@ -2,6 +2,13 @@ import kotlinx.cinterop.*
 import platform.windows.*
 
 fun main(args: Array<String>) {
-    MessageBoxW(null, "Konan говорит:\nЗДРАВСТВУЙ МИР!\n",
+    val message = StringBuilder()
+    memScoped {
+      val buffer = allocArray<UShortVar>(MAX_PATH)
+      GetModuleFileNameW(null, buffer, MAX_PATH)
+      val path = buffer.toKString().split("\\").dropLast(1).joinToString("\\")
+      message.append("Я нахожусь в $path\n")
+    }
+    MessageBoxW(null, "Konan говорит:\nЗДРАВСТВУЙ МИР!\n$message",
             "Заголовок окна", (MB_YESNOCANCEL or MB_ICONQUESTION).convert())
 }