SDL2 exporting fix (#5945)

* add a test for sdl2 title changing

* export things for SDL2 in the get() method, which runs at link time, as opposed to process_args which is just for compiling to bitcode. add a test for sdl2 usage with intermediate bitcode

Author: kripken

tests/sdl2_misc.c

@@ -0,0 +1,48 @@
+#include "SDL2/SDL.h"
+
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+
+#include <emscripten.h>
+
+int main(int argc, char *argv[])
+{
+    SDL_Window *window;
+    SDL_Surface *surface;
+    SDL_Cursor *cursor;
+
+    if ( SDL_Init(SDL_INIT_VIDEO) != 0 ) {
+        printf("Unable to initialize SDL: %s\n", SDL_GetError());
+        return 1;
+    }
+
+    window = SDL_CreateWindow(
+        "sdl2_misc",
+        SDL_WINDOWPOS_UNDEFINED,
+        SDL_WINDOWPOS_UNDEFINED,
+        100,
+        100,
+        0
+    );
+
+    EM_ASM({
+      assert(document.title === 'sdl2_misc');
+    });
+    const char* intended = "a custom window title";
+    SDL_SetWindowTitle(window, intended);
+    const char* seen = SDL_GetWindowTitle(window);
+    if (strcmp(intended, seen) != 0) {
+        printf("Got a weird title back: %s\n", seen);
+        return 1;
+    }
+    EM_ASM({
+      assert(document.title === 'a custom window title');
+    });
+
+    SDL_DestroyWindow(window);
+    SDL_Quit();
+    REPORT_RESULT(1);
+
+    return 0;
+}

tests/test_browser.py

@@ -2835,6 +2835,15 @@ def test_sdl2_custom_cursor(self):
     shutil.copyfile(path_from_root('tests', 'cursor.bmp'), os.path.join(self.get_dir(), 'cursor.bmp'))
     self.btest('sdl2_custom_cursor.c', expected='1', args=['--preload-file', 'cursor.bmp', '-s', 'USE_SDL=2'])
 
+  def test_sdl2_misc(self):
+    self.btest('sdl2_misc.c', expected='1', args=['-s', 'USE_SDL=2'])
+    print('also test building to object files first')
+    src = open(path_from_root('tests', 'sdl2_misc.c')).read()
+    open('test.c', 'w').write(self.with_report_result(src))
+    Popen([PYTHON, EMCC, 'test.c', '-s', 'USE_SDL=2', '-o', 'test.o']).communicate()
+    Popen([PYTHON, EMCC, 'test.o', '-s', 'USE_SDL=2', '-o', 'test.html']).communicate()
+    self.run_browser('test.html', '...', '/report_result?1')
+
   def test_cocos2d_hello(self):
     from tools import system_libs
     cocos2d_root = os.path.join(system_libs.Ports.get_build_dir(), 'Cocos2d')

tools/ports/sdl.py

@@ -20,6 +20,9 @@ def setup_includes():
 
 def get(ports, settings, shared):
   if settings.USE_SDL == 2:
+    # SDL2 uses some things on the Module object, make sure they are exported
+    settings.EXPORTED_RUNTIME_METHODS.append('Pointer_stringify')
+    # get the port
     ports.fetch_project('sdl2', 'https://github.com/emscripten-ports/SDL2/archive/' + TAG + '.zip', 'SDL2-' + TAG)
     def create():
       # we are rebuilding SDL, clear dependant projects so they copy in their includes to ours properly
@@ -56,7 +59,6 @@ def process_args(ports, args, settings, shared):
   elif settings.USE_SDL == 2:
     get(ports, settings, shared)
     args += ['-Xclang', '-isystem' + os.path.join(shared.Cache.get_path('ports-builds'), 'sdl2', 'include')]
-    settings.EXPORTED_RUNTIME_METHODS.append('Pointer_stringify')
   return args
 
 def show():