LibWasm: Let the interpreter itself manage the call frame

Author: https://github.com/alimpfard
Commit: https://github.com/SerenityOS/serenity/commit/477ab6dc4cc
Pull-request: https://github.com/SerenityOS/serenity/pull/7482
Reviewed-by: https://github.com/ADKaster

Userland/Libraries/LibWasm/AbstractMachine/Interpreter.cpp

@@ -128,7 +128,7 @@ void BytecodeInterpreter::call_address(Configuration& configuration, FunctionAdd
 
     Result result { Trap {} };
     {
-        Configuration::CallFrameHandle handle { configuration };
+        CallFrameHandle handle { *this, configuration };
         result = configuration.call(*this, address, move(args));
     }
 
@@ -437,7 +437,10 @@ void BytecodeInterpreter::interpret(Configuration& configuration, InstructionPoi
         for (size_t i = 0; i < frame.arity(); ++i)
             results.prepend(configuration.stack().pop());
         // drop all locals
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
         Optional<Label> last_label;
+#pragma GCC diagnostic pop
         for (; !configuration.stack().is_empty();) {
             auto entry = configuration.stack().pop();
             if (entry.has<Label>()) {

Userland/Libraries/LibWasm/AbstractMachine/Interpreter.h

@@ -23,6 +23,19 @@ struct BytecodeInterpreter : public Interpreter {
     virtual bool did_trap() const override { return m_do_trap; }
     virtual void clear_trap() override { m_do_trap = false; }
 
+    struct CallFrameHandle {
+        explicit CallFrameHandle(BytecodeInterpreter& interpreter, Configuration& configuration)
+            : m_configuration_handle(configuration)
+            , m_interpreter(interpreter)
+        {
+        }
+
+        ~CallFrameHandle() = default;
+
+        Configuration::CallFrameHandle m_configuration_handle;
+        BytecodeInterpreter& m_interpreter;
+    };
+
 protected:
     virtual void interpret(Configuration&, InstructionPointer&, const Instruction&);
     void branch_to_label(Configuration&, LabelIndex);

Userland/Utilities/wasm.cpp

@@ -193,7 +193,7 @@ static bool pre_interpret_hook(Wasm::Configuration& config, Wasm::InstructionPoi
 
             Wasm::Result result { Wasm::Trap {} };
             {
-                Wasm::Configuration::CallFrameHandle handle { config };
+                Wasm::BytecodeInterpreter::CallFrameHandle handle { g_interpreter, config };
                 result = config.call(g_interpreter, *address, move(values));
             }
             if (result.is_trap())