added ToadKing libco support that fixes emscripten build (#90)

Author: gitGalu

libretro/libretro-common/libco/emscripten_fiber.c

@@ -0,0 +1,85 @@
+#define LIBCO_C
+#include "libco.h"
+
+#define _BSD_SOURCE
+#define _XOPEN_SOURCE 500
+#include <stdlib.h>
+#include <emscripten/fiber.h>
+#include <stdio.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef void (*thread_cb)();
+
+// Todo: dynamic stack size
+typedef struct {
+    emscripten_fiber_t context;
+    char *asyncify_stack;
+    char *c_stack;
+} Fiber;
+
+static inline void thread_entry(void *entrypoint) {
+  ((thread_cb)entrypoint)();
+}
+
+static Fiber main_fiber;
+static Fiber* running_fiber = 0;
+
+void init_main_fiber() {
+  main_fiber.asyncify_stack = (char*)malloc(16385 * sizeof(char));
+  emscripten_fiber_init_from_current_context(&main_fiber.context, main_fiber.asyncify_stack, 16385);
+  running_fiber = &main_fiber;
+}
+
+cothread_t co_active() {
+  if(!running_fiber) init_main_fiber();
+
+  return (cothread_t)running_fiber;
+}
+
+cothread_t co_derive(void* memory, unsigned int heapsize, void (*coentry)(void)) {
+  if(!running_fiber) init_main_fiber();
+
+  Fiber* fiber = malloc(sizeof(Fiber));
+  fiber->c_stack = (char*) memory;
+  fiber->asyncify_stack = (char*) malloc(heapsize * sizeof(char));
+
+  emscripten_fiber_init(&fiber->context, thread_entry, coentry, fiber->c_stack, heapsize, fiber->asyncify_stack, heapsize);
+
+  return (cothread_t)fiber;
+}
+
+cothread_t co_create(unsigned int heapsize, void (*coentry)(void)) {
+  if(!running_fiber) init_main_fiber();
+
+  Fiber* fiber = malloc(sizeof(Fiber));
+  fiber->c_stack = (char*)malloc(heapsize * sizeof(char));
+  fiber->asyncify_stack = (char*)malloc(heapsize * sizeof(char));
+
+  emscripten_fiber_init(&fiber->context, thread_entry, coentry, fiber->c_stack, heapsize, fiber->asyncify_stack, heapsize);
+
+  return (cothread_t)fiber;
+}
+
+void co_delete(cothread_t cothread) {
+  if(cothread) {
+    free(cothread);
+  }
+}
+
+void co_switch(cothread_t cothread) {
+  Fiber* old_fiber = running_fiber;
+  running_fiber = (Fiber*)cothread;
+  
+  emscripten_fiber_swap(&old_fiber->context, &running_fiber->context);
+}
+
+int co_serializable() {
+  return 0;
+}
+
+#ifdef __cplusplus
+}
+#endif

libretro/libretro-common/libco/libco.c

@@ -9,7 +9,9 @@ void *genode_alloc_secondary_stack(unsigned long stack_size);
 void genode_free_secondary_stack(void *stack);
 #endif
 
-#if defined _MSC_VER
+#if defined(EMSCRIPTEN)
+  #include "emscripten_fiber.c"
+#elif defined _MSC_VER
   #include <Windows.h>
   #if WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_APP)
     #include "fiber.c"

libretro/libretro-core.c

@@ -1171,7 +1171,7 @@ void retro_audio_cb(short l, short r)
 
 /* Forward declarations */
 void retro_sound_update(void);
-void Retro_PollEvent(void);
+int Retro_PollEvent(void);
 
 void retro_run(void)
 {