From 477ab6dc4cc91225b334cc550f8d6b79b997d536 Mon Sep 17 00:00:00 2001
From: Ali Mohammad Pur <ali.mpfard@gmail.com>
Date: Mon, 24 May 2021 21:24:28 +0430
Subject: [PATCH] LibWasm: Let the interpreter itself manage the call frame

---
 .../LibWasm/AbstractMachine/Interpreter.cpp         |  5 ++++-
 .../Libraries/LibWasm/AbstractMachine/Interpreter.h | 13 +++++++++++++
 Userland/Utilities/wasm.cpp                         |  2 +-
 3 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/Userland/Libraries/LibWasm/AbstractMachine/Interpreter.cpp b/Userland/Libraries/LibWasm/AbstractMachine/Interpreter.cpp
index 45942f4dc0..5fee8c1aa7 100644
--- a/Userland/Libraries/LibWasm/AbstractMachine/Interpreter.cpp
+++ b/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>()) {
diff --git a/Userland/Libraries/LibWasm/AbstractMachine/Interpreter.h b/Userland/Libraries/LibWasm/AbstractMachine/Interpreter.h
index cbe37862a8..73ab26c1ff 100644
--- a/Userland/Libraries/LibWasm/AbstractMachine/Interpreter.h
+++ b/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);
diff --git a/Userland/Utilities/wasm.cpp b/Userland/Utilities/wasm.cpp
index 5ca2d8e79b..0362774bff 100644
--- a/Userland/Utilities/wasm.cpp
+++ b/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())