Remove exceptions from the sandbox implementation in libretro builds

binding-sandbox/binding-base.cpp

@@ -83,7 +83,7 @@ wasm_ptr_t binding_base::sandbox_malloc(wasm_size_t size) {
 
     // Verify that the entire allocated buffer is in valid memory
     wasm_ptr_t buf_end;
-    if (buf == 0 || __builtin_add_overflow(buf, size, &buf_end) || buf_end >= instance().w2c_memory.size) {
+    if (buf == 0 || (buf_end = buf + size) < buf || buf_end >= instance().w2c_memory.size) {
         return 0;
     }
 

binding-sandbox/sandbox.cpp

@@ -46,8 +46,8 @@ usize sandbox::sandbox_malloc(usize size) {
 
     // Verify that the returned pointer is non-null and the entire allocated buffer is in valid memory
     usize buf_end;
-    if (buf == WASM_NULL || __builtin_add_overflow(buf, size, &buf_end) || buf_end >= ruby->w2c_memory.size) {
-        throw SandboxOutOfMemoryException();
+    if (buf == WASM_NULL || (buf_end = buf + size) < buf || buf_end >= ruby->w2c_memory.size) {
+        throw std::bad_alloc();
     }
 
     return buf;
@@ -58,7 +58,6 @@ void sandbox::sandbox_free(usize ptr) {
 }
 
 sandbox::sandbox() : ruby(new struct w2c_ruby), wasi(new wasi_t(ruby)), bindings(ruby), yielding(false), transitioning(false) {
-    try {
     // Initialize the sandbox
     wasm2c_ruby_instantiate(RB, wasi.get());
     w2c_ruby_mkxp_sandbox_init(
@@ -120,7 +119,7 @@ sandbox::sandbox() : ruby(new struct w2c_ruby), wasi(new wasi_t(ruby)), bindings
         AWAIT(state = w2c_ruby_ruby_exec_node(RB, node));
     }
     if (!valid || state) {
-            throw SandboxNodeException();
+        std::abort();
     }
     sandbox_free(state_buf);
 
@@ -131,10 +130,6 @@ sandbox::sandbox() : ruby(new struct w2c_ruby), wasi(new wasi_t(ruby)), bindings
     AWAIT(enc = w2c_ruby_rb_enc_from_encoding(RB, encoding));
     AWAIT(w2c_ruby_rb_enc_set_default_internal(RB, enc));
     AWAIT(w2c_ruby_rb_enc_set_default_external(RB, enc));
-    } catch (SandboxException &) {
-        wasm2c_ruby_free(RB);
-        throw;
-    }
 }
 
 sandbox::~sandbox() {

binding-sandbox/types.h

@@ -53,12 +53,4 @@ typedef float f32;
 typedef double f64;
 #endif // WASM_RT_CORE_TYPES_DEFINED
 
-struct SandboxException {};
-// The call to `ruby_executable_node()` or `ruby_exec_node()` failed when initializing Ruby.
-struct SandboxNodeException : SandboxException {};
-// Failed to allocate memory.
-struct SandboxOutOfMemoryException : SandboxException {};
-// An exception occurred inside of Ruby and was not caught.
-struct SandboxTrapException : SandboxException {};
-
 #endif // MKXPZ_SANDBOX_TYPES_H

binding-sandbox/wasi.cpp

@@ -805,7 +805,7 @@ extern "C" u32 w2c_wasi__snapshot__preview1_poll_oneoff(wasi_t *wasi, usize in,
 
 extern "C" void w2c_wasi__snapshot__preview1_proc_exit(wasi_t *wasi, u32 rval) {
     WASI_DEBUG("proc_exit(%u)\n", rval);
-    throw SandboxTrapException();
+    std::abort();
 }
 
 extern "C" u32 w2c_wasi__snapshot__preview1_random_get(wasi_t *wasi, usize buf, u32 buf_len) {

libretro/sandbox-bindgen.rb

@@ -291,7 +291,7 @@ PRELUDE = <<~HEREDOC
   bindings::rb_data_type::rb_data_type(wasm_ptr_t ptr) : ptr(ptr) {}
 
   wasm_ptr_t bindings::rb_data_type::get() const {
-      if (ptr == 0) throw SandboxTrapException();
+      if (ptr == 0) std::abort();
       return ptr;
   }
 
@@ -309,12 +309,12 @@ POSTSCRIPT = <<~HEREDOC
 
       buf = sandbox_malloc(9 * sizeof(wasm_ptr_t));
       if (buf == 0) {
-          throw SandboxOutOfMemoryException();
+          throw std::bad_alloc();
       }
       str = sandbox_malloc(std::strlen(wrap_struct_name) + 1);
       if (str == 0) {
           sandbox_free(buf);
-          throw SandboxOutOfMemoryException();
+          throw std::bad_alloc();
       }
 
       std::strcpy((char *)(**this + str), wrap_struct_name);
@@ -480,7 +480,7 @@ File.readlines('tags', chomp: true).each do |line|
         end
         coroutine_initializer += <<~HEREDOC
               default:
-                  throw SandboxTrapException();
+                  std::abort();
           }
         HEREDOC
       else
@@ -498,7 +498,7 @@ File.readlines('tags', chomp: true).each do |line|
     elsif !handler[:buf_size].nil?
       coroutine_initializer += <<~HEREDOC
         f#{i} = bind.sandbox_malloc(#{handler[:buf_size].gsub('PREV_ARG', "a#{i - 1}").gsub('ARG', "a#{i}")});
-        if (f#{i} == 0) throw SandboxOutOfMemoryException();
+        if (f#{i} == 0) throw std::bad_alloc();
       HEREDOC
       coroutine_initializer += handler[:serialize].gsub('PREV_ARG', "a#{i - 1}").gsub('ARG', "a#{i}").gsub('BUF', "f#{i}")
       coroutine_initializer += "\n"
@@ -523,7 +523,7 @@ File.readlines('tags', chomp: true).each do |line|
         fp = w2c_ruby_rb_wasm_get_stack_pointer(&bind.instance());
         sp = fp - CEIL_WASMSTACKALIGN(a#{args.length - 2} * sizeof(VALUE));
         if (sp > fp) {
-            throw SandboxOutOfMemoryException();
+            throw std::bad_alloc();
         }
         w2c_ruby_rb_wasm_set_stack_pointer(&bind.instance(), sp);
         std::va_list a;
@@ -550,7 +550,7 @@ File.readlines('tags', chomp: true).each do |line|
             fp = w2c_ruby_rb_wasm_get_stack_pointer(&bind.instance());
             sp = fp - CEIL_WASMSTACKALIGN(n * sizeof(VALUE));
             if (sp > fp) {
-                throw SandboxOutOfMemoryException();
+                throw std::bad_alloc();
             }
             w2c_ruby_rb_wasm_set_stack_pointer(&bind.instance(), sp);
             for (wasm_size_t i = 0; i < n; ++i) {

src/core.cpp

@@ -320,13 +320,7 @@ static bool init_sandbox() {
 
     audio.emplace(*thread_data);
 
-    try {
     mkxp_retro::sandbox.emplace();
-    } catch (SandboxException) {
-        log_printf(RETRO_LOG_ERROR, "Failed to initialize Ruby\n");
-        deinit_sandbox();
-        return false;
-    }
 
     {
         float refresh_rate;
@@ -467,15 +461,10 @@ extern "C" RETRO_API void retro_run() {
     }
 
     if (should_render) {
-        try {
         if (sb().run<struct main>()) {
             log_printf(RETRO_LOG_INFO, "[Sandbox] Ruby terminated normally\n");
             deinit_sandbox();
         }
-        } catch (SandboxException) {
-            log_printf(RETRO_LOG_ERROR, "[Sandbox] Ruby threw an exception\n");
-            deinit_sandbox();
-        }
     } else if (!dupe_supported && mkxp_retro::sandbox.has_value()) {
         shState->graphics().repaint(sb().transitioning);
     }