SDL creating window corrupts heap when compiled with -g #15489
Description
I am trying to use a singleton pattern in my rendering pipeline. But SDL doesn't like it when I compile without optimizations and it corrupt the heap. Here is the code:
header.h
#ifndef EverythingH
#define EverythingH
#include <emscripten.h>
#include <SDL.h>
#define GL_GLEXT_PROTOTYPES 1
#include <SDL_opengles2.h>
#include <string>
class Everything
{
public:
void init();
void doStuff();
};
extern Everything e;
#endifmain.cpp
#include "header.h"
void MainLoop()
{
e.doStuff();
}
void InitSingletons()
{
e.init();
}
int main()
{
//Init singletons here
InitSingletons();
//main loop is started here
emscripten_set_main_loop( MainLoop, 0, true );
return 0;
}Everything.cpp
#include "header.h"
EMSCRIPTEN_KEEPALIVE SDL_Window *SDLWindow; //I tried it without EMSCRIPTEN_KEEPALIVE
void Everything::init()
{
SDL_CreateWindowAndRenderer(640, 480, 0, &SDLWindow, nullptr);
SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 2);
SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 0);
SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 24);
}
void Everything::doStuff()
{
}
EMSCRIPTEN_KEEPALIVE Everything e; //I tried it without EMSCRIPTEN_KEEPALIVE index.html
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body>
<!-- Create the canvas that the C++ code will draw into -->
<canvas id="canvas" oncontextmenu="event.preventDefault()"></canvas>
<!-- Allow the C++ to access the canvas element -->
<script type='text/javascript'>
var canv = document.getElementById('canvas');
var Module = {
canvas: canv
};
</script>
<!-- Call the javascript glue code (index.js) as generated by Emscripten -->
<script src="index.js"></script>
</body>
</html>compile command
em++ main.cpp Everything.cpp -std=c++11 -g -s WASM=1 -s USE_SDL=2 -o index.js
python server to run
python -m http.server 8080then connect to 127.0.0.1:8080
Errors:
index.js:4384 emscripten_set_main_loop_timing: Cannot set timing mode for main loop since a main loop does not exist! Call emscripten_set_main_loop first to set one up.
Aborted(Runtime error: The application has corrupted its heap memory area (address zero)!)
Uncaught (in promise) RuntimeError: Aborted(Runtime error: The application has corrupted its heap memory area (address zero)!)
Info em++ -v gives
emcc (Emscripten gcc/clang-like replacement + linker emulating GNU ld) 2.0.34 (0d24418f0eac4828f096ee070dae8472d427edaa)
clang version 14.0.0 (https://github.com/llvm/llvm-project 3d39612b3dd3f6b67ee63da305d30606abbe7287)
Target: wasm32-unknown-emscripten
Thread model: posix
InstalledDir: C:/emsdk/upstream/bin
Edit:
in fact just compile the following with -g instead of -O3 to get the error
https://github.com/timhutton/opengl-canvas-wasm