Add basic support for Windows with mingw-w64

Interop/Indexer/build.gradle

@@ -29,9 +29,6 @@ apply plugin: org.jetbrains.kotlin.NativeInteropPlugin
 
 apply plugin: 'c'
 
-def javaHome = System.getProperty('java.home')
-def compilerArgsForJniIncludes = ["", "linux", "darwin"].collect { "-I$javaHome/../include/$it" } as String[]
-
 model {
     components {
         clangstubs(NativeLibrarySpec) {
@@ -40,12 +37,18 @@ model {
             }
 
             binaries.all {
-                cCompiler.args compilerArgsForJniIncludes
+                cCompiler.args hostCompilerArgsForJni
                 cCompiler.args "-I$llvmDir/include"
             }
 
             binaries.withType(SharedLibraryBinarySpec) {
-                linker.args "$llvmDir/lib/${System.mapLibraryName("clang")}"
+                final String libclang
+                if (isWindows()) {
+                    libclang = "bin/libclang.dll"
+                } else {
+                    libclang = "lib/${System.mapLibraryName("clang")}"
+                }
+                linker.args "$llvmDir/$libclang"
             }
         }
    }

Interop/Runtime/build.gradle

@@ -27,9 +27,6 @@ buildscript {
 apply plugin: 'kotlin'
 apply plugin: 'c'
 
-def javaHome = System.getProperty('java.home')
-def compilerArgsForJniIncludes = ["", "linux", "darwin"].collect { "-I$javaHome/../include/$it" } as String[]
-
 model {
     components {
         callbacks(NativeLibrarySpec) {
@@ -41,7 +38,7 @@ model {
                 def host = rootProject.ext.host
                 def hostLibffiDir = rootProject.ext.get("${host}LibffiDir")
 
-                cCompiler.args compilerArgsForJniIncludes
+                cCompiler.args hostCompilerArgsForJni
                 cCompiler.args "-I$hostLibffiDir/include"
 
                 linker.args "$hostLibffiDir/lib/libffi.a"

Interop/Runtime/src/callbacks/c/callbacks.c

@@ -147,7 +147,7 @@ static JNIEnv* getCurrentEnv() {
     return env;
 }
 
-jint JNI_OnLoad(JavaVM *vm_, void *reserved) {
+JNIEXPORT jint JNICALL JNI_OnLoad(JavaVM *vm_, void *reserved) {
     vm = vm_;
     return JNI_VERSION_1_1;
 }

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

@@ -1277,7 +1277,7 @@ class StubGenerator(
             },
 
             compilerArgs = configuration.library.compilerArgs + when (platform) {
-                KotlinPlatform.JVM -> listOf("", "linux", "darwin").map {
+                KotlinPlatform.JVM -> listOf("", "linux", "darwin", "win32").map {
                     val javaHome = System.getProperty("java.home")
                     "-I$javaHome/../include/$it"
                 }

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

@@ -61,11 +61,11 @@ private fun parseArgs(args: Array<String>): Map<String, List<String>> {
 
 private val host: String by lazy {
     val os = System.getProperty("os.name")
-    when (os) {
-        "Linux" -> "linux"
-        "Windows" -> "win"
-        "Mac OS X" -> "osx"
-        "FreeBSD" -> "freebsd"
+    when {
+        os == "Linux" -> "linux"
+        os.startsWith("Windows") -> "mingw"
+        os == "Mac OS X" -> "osx"
+        os == "FreeBSD" -> "freebsd"
         else -> {
             throw IllegalArgumentException("we don't know ${os} value")
         }
@@ -87,7 +87,8 @@ private val knownTargets = mapOf(
         "iphone_sim" to "ios_sim",
         "ios_sim" to "ios_sim",
         "raspberrypi" to "raspberrypi",
-        "android_arm32" to "android_arm32"
+        "android_arm32" to "android_arm32",
+        "mingw" to "mingw"
 )
 
 
@@ -205,9 +206,13 @@ private fun Properties.defaultCompilerOpts(target: String, dependencies: String)
     val llvmHomeDir = getHostSpecific("llvmHome")!!
     val llvmHome = "$dependencies/$llvmHomeDir"
 
-    System.load("$llvmHome/lib/${System.mapLibraryName("clang")}")
+    val libclang = when (host) {
+        "mingw" -> "$llvmHome/bin/libclang.dll"
+        else -> "$llvmHome/lib/${System.mapLibraryName("clang")}"
+    }
+    System.load(libclang)
 
-    val llvmVersion = getProperty("llvmVersion")!!
+    val llvmVersion = getHostSpecific("llvmVersion")!!
 
     // StubGenerator passes the arguments to libclang which
     // works not exactly the same way as the clang binary and
@@ -234,6 +239,9 @@ private fun Properties.defaultCompilerOpts(target: String, dependencies: String)
             return archSelector + commonArgs + listOf(
                     "-B$binDir", "--gcc-toolchain=$targetToolchain")
         }
+        "mingw" -> {
+            return archSelector + commonArgs + listOf("-B$targetSysRoot/bin")
+        }
         else -> error("Unexpected target: ${target}")
     }
 }