Provide entry point customization (#352)

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

@@ -1148,7 +1148,7 @@ class StubGenerator(
     /**
      * Produces to [out] the contents of C source file to be compiled into JNI lib used for Kotlin bindings impl.
      */
-    fun generateCFile(headerFiles: List<String>) {
+    fun generateCFile(headerFiles: List<String>, entryPoint: String?) {
         out("#include <stdint.h>")
         if (platform == KotlinPlatform.JVM) {
             out("#include <jni.h>")
@@ -1167,6 +1167,14 @@ class StubGenerator(
                 System.err.println("Warning: cannot generate C JNI function definition ${func.name}")
             }
         }
+
+        if (entryPoint != null) {
+            out("extern int Konan_main(int argc, char** argv);")
+            out("")
+            out("int $entryPoint(int argc, char** argv) {")
+            out("  return  Konan_main(argc, argv);")
+            out("}")
+        }
     }
 
     private tailrec fun Type.unwrapTypedefs(): Type = if (this is Typedef) {

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

@@ -238,6 +238,7 @@ private fun processLib(konanHome: String,
         defaultOpts + additionalCompilerOpts 
     val compiler = "clang"
     val language = Language.C
+    val entryPoint = config.getSpaceSeparated("entryPoint").singleOrNull()
     val linkerOpts = 
         config.getSpaceSeparated("linkerOpts").toTypedArray() +
         defaultOpts + additionalLinkerOpts 
@@ -282,7 +283,7 @@ private fun processLib(konanHome: String,
 
     outCFile.bufferedWriter().use { out ->
         gen.withOutput({ out.appendln(it) }) {
-            gen.generateCFile(headerFiles)
+            gen.generateCFile(headerFiles, entryPoint)
         }
     }
 

runtime/src/launcher/cpp/launcher.cpp

@@ -18,9 +18,9 @@ OBJ_GETTER(setupArgs, int argc, char** argv) {
 }
 
 //--- main --------------------------------------------------------------------//
-extern "C" KInt Konan_start(const ObjHeader* );
+extern "C" KInt Konan_start(const ObjHeader*);
 
-int main(int argc, char** argv) {
+extern "C" int Konan_main(int argc, char** argv) {
   RuntimeState* state = InitRuntime();
 
   if (state == nullptr) {

runtime/src/launcher/cpp/main.cpp

@@ -0,0 +1,5 @@
+extern "C" int Konan_main(int argc, char** argv);
+
+int main(int argc, char** argv) {
+  return Konan_main(argc, argv);
+}

samples/tetris/build

@@ -4,6 +4,8 @@ DIR=.
 DIST=../../dist
 OSX_CFLAGS=-I/Library/Frameworks/SDL2.framework/Headers
 OSX_LINKER_ARGS="-F /Library/Frameworks -framework SDL2"
+#OSX_CFLAGS=-I/opt/local/include/SDL2
+#OSX_LINKER_ARGS="-L/opt/local/lib -lSDL2"
 LINUX_CFLAGS=-I/usr/include/SDL2
 LINUX_LINKER_ARGS="-L/usr/lib/x86_64-linux-gnu -lSDL2"
 

samples/tetris/sdl.def

@@ -2,6 +2,7 @@ headers = SDL.h stdio.h string.h unistd.h stdlib.h time.h
 excludedFunctions = _IO_flockfile _IO_funlockfile _IO_ftrylockfile \
     _IO_cleanup_region_start _IO_cleanup_region_end \
     mkstemp_dprotected_np 
+entryPoint = SDL_main
 
 compilerOpts.osx = -D_POSIX_SOURCE -mxsave -mavx -mf16c
 compilerOpts.linux = -D_REENTRANT

samples/tetris/tetris.kt

@@ -491,10 +491,6 @@ class Game(width: Int, height: Int, val visualizer: GameFieldVisualizer, val use
 
 }
 
-fun main(args: Array<String>) {
-    SDL_main(args)
-}
-
 fun get_SDL_Error() = SDL_GetError()!!.asCString().toString()
 
 class SDL_Visualizer(val width: Int, val height: Int): GameFieldVisualizer, UserInput {
@@ -806,8 +802,7 @@ class SDL_Visualizer(val width: Int, val height: Int): GameFieldVisualizer, User
     }
 }
 
-@ExportForCppRuntime("SDL_main")
-fun SDL_main(args: Array<String>) {
+fun main(args: Array<String>) {
     var startLevel = 0
     var width = 10
     var height = 20
@@ -828,4 +823,4 @@ fun SDL_main(args: Array<String>) {
     game.startNewGame(startLevel)
 
     return
-}
+}