build: use our own main() wrapper in addition to SDL's, and only

in that case. Currently only works with GCC.

configure.ac

@@ -197,7 +197,8 @@ AC_MSG_CHECKING(for -mwindows -mwin32)
 AC_TRY_LINK([], [],
  [AC_MSG_RESULT(yes)
   CXXFLAGS="${CXXFLAGS} -mwindows -mwin32"
-  LOL_LIBS="${LOL_LIBS} -uWinMain -u_WinMain@16"],
+  dnl  If we come across these symbols, try to link them
+  LOL_LIBS="${LOL_LIBS} -uWinMain -u_WinMain@16 -u_SDL_main"],
  [AC_MSG_RESULT(no)])
 LIBS="$LIBS_save"
 

src/core.h

@@ -68,9 +68,14 @@ static inline int isnan(float f)
 #   define main lol_android_main
 #endif
 
-/* If using SDL on Windows or OS X, let it override main() */
-#if defined USE_SDL && (defined _WIN32 || defined __APPLE__)
+/* If using SDL, let it override main() but immediately replace
+ * the override with ours. */
+#if defined USE_SDL
 #   include <SDL_main.h>
+#   if defined main && !LOL_DONT_DIVERT_MAIN
+#       undef main
+#       define main lol_sdl_main
+#   endif
 #endif
 
 // Base types

src/platform/sdl/sdlapp.cpp

@@ -12,6 +12,10 @@
 #   include "config.h"
 #endif
 
+/* This instructs our headers to let SDL override the "main"
+ * symbol using its macros. */
+#define LOL_DONT_DIVERT_MAIN 1
+
 #if defined USE_SDL
 #   if defined HAVE_SDL_SDL_H
 #      include <SDL/SDL.h>
@@ -37,6 +41,33 @@ HWND g_hwnd = NULL;
 extern IDirect3DDevice9 *g_d3ddevice;
 #endif
 
+#if defined main
+#   if defined _MSC_VER
+#       pragma comment(linker, "/alternatename:_lol_sdl_main=_lol_sdl_main_msvc")
+#       define WRAPPER lol_sdl_main_msvc
+#   else
+int lol_sdl_main() __attribute__((weak));
+int lol_sdl_main(int argc, char **argv) __attribute__((weak));
+int lol_sdl_main(int argc, char **argv, char **envp) __attribute__((weak));
+#       define WRAPPER lol_sdl_main
+#   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);
+    ret += lol_sdl_main(argc, argv, NULL);
+    return ret;
+}
+#endif
+
 namespace lol
 {
 

test/math/Makefile.am

@@ -9,7 +9,7 @@ noinst_PROGRAMS = pi poly remez
 
 pi_SOURCES = pi.cpp
 pi_CPPFLAGS = @LOL_CFLAGS@
-pi_LDFLAGS = $(top_builddir)/src/liblol.a @LOL_LIBS@
+pi_LDFLAGS = -u_SDL_main -uSDL_main $(top_builddir)/src/liblol.a @LOL_LIBS@
 pi_DEPENDENCIES = $(top_builddir)/src/liblol.a
 
 poly_SOURCES = poly.cpp