build: provide weak symbols for lol_sdl_main on Visual Studio.

src/core.h

@@ -69,12 +69,27 @@ static inline int isnan(float f)
 #endif
 
 /* If using SDL, let it override main() but immediately replace
- * the override with ours. */
+ * the override with ours, then declare weak symbols to ensure one
+ * of our dummy functions gets replaced by the user's main(). */
 #if defined USE_SDL
 #   include <SDL_main.h>
 #   if defined main && !LOL_DONT_DIVERT_MAIN
 #       undef main
 #       define main lol_sdl_main
+#       if defined _MSC_VER
+int lol_sdl_main();
+int lol_sdl_main_msvc();
+#pragma comment(linker, "/alternatename:?lol_sdl_main@@YAHXZ" \
+                                      "=?lol_sdl_main_msvc@@YAHXZ")
+int lol_sdl_main(int argc, char **argv);
+int lol_sdl_main_msvc(int argc, char **argv);
+#pragma comment(linker, "/alternatename:?lol_sdl_main@@YAHHPEAPEAD@Z" \
+                                      "=?lol_sdl_main_msvc@@YAHHPEAPEAD@Z")
+int lol_sdl_main(int argc, char **argv, char **envp);
+int lol_sdl_main_msvc(int argc, char **argv, char **envp);
+#pragma comment(linker, "/alternatename:?lol_sdl_main@@YAHHPEAPEAD0@Z" \
+                                      "=?lol_sdl_main_msvc@@YAHHPEAPEAD0@Z")
+#       endif
 #   endif
 #endif
 

src/platform/sdl/sdlapp.cpp

@@ -43,7 +43,9 @@ extern IDirect3DDevice9 *g_d3ddevice;
 
 #if defined main
 #   if defined _MSC_VER
-#       pragma comment(linker, "/alternatename:_lol_sdl_main=_lol_sdl_main_msvc")
+int lol_sdl_main();
+int lol_sdl_main(int argc, char **argv);
+int lol_sdl_main(int argc, char **argv, char **envp);
 #       define WRAPPER lol_sdl_main_msvc
 #   else
 int lol_sdl_main() __attribute__((weak));
@@ -53,13 +55,13 @@ int lol_sdl_main(int argc, char **argv, char **envp) __attribute__((weak));
 #   endif
 
 /* One of these wrappers will be overridden by the user's version */
+
 int WRAPPER() { return 0; }
 int WRAPPER(int argc, char **argv) { return 0; }
 int WRAPPER(int argc, char **argv, char **envp) { return 0; }
 
 int main(int argc, char *argv[])
 {
-printf("LOL OK\n");
     int ret = 0;
     ret += lol_sdl_main();
     ret += lol_sdl_main(argc, argv);

test/testsuite.cpp

@@ -19,7 +19,7 @@
 
 #include <lol/unit.h>
 
-int main(int argc, char **argv)
+int main()
 {
     lol::TextTestRunner runner;
     bool success = runner.Run();