From 70d02b1d661b4c057f53bb1c5ca563e289c80dfd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Pawe=C5=82=20Bylica?= <pawel.bylica@imapp.pl>
Date: Thu, 15 Jan 2015 16:27:57 +0100
Subject: [PATCH] RETURN implementation: JIT returns data

---
 libevmjit/interface.cpp | 39 ++++++++++++---------------------------
 libevmjit/interface.h   | 11 ++++++++++-
 2 files changed, 22 insertions(+), 28 deletions(-)

diff --git a/libevmjit/interface.cpp b/libevmjit/interface.cpp
index 6a729f3d0..eef92d00f 100644
--- a/libevmjit/interface.cpp
+++ b/libevmjit/interface.cpp
@@ -5,14 +5,12 @@
 extern "C"
 {
 
-int evmjit_run(void* _data, void* _env)
+evmjit_result evmjit_run(void* _data, void* _env)
 {
 	using namespace dev::eth::jit;
 
 	auto data = static_cast<RuntimeData*>(_data);
 
-	std::cerr << "GAS: " << data->elems[RuntimeData::Gas].a << "\n";
-
 	ExecutionEngine engine;
 
 	auto codePtr = data->code;
@@ -20,30 +18,17 @@ int evmjit_run(void* _data, void* _env)
 	bytes bytecode;
 	bytecode.insert(bytecode.end(), codePtr, codePtr + codeSize);
 
-	auto result = engine.run(bytecode, data, static_cast<Env*>(_env));
-	return static_cast<int>(result);
-}
-
-// Runtime callback functions  - implementations must be provided by external language (Go, C++, Python)
-void evm_jit_rt_sload(evm_jit_rt* _rt, i256* _index, i256* _ret);
-void evm_jit_rt_sstore(evm_jit_rt* _rt, i256* _index, i256* _value);
-void evm_jit_rt_balance(evm_jit_rt* _rt, h256* _address, i256* _ret);
-// And so on...
-
-evm_jit* evm_jit_create(evm_jit_rt*)
-{
-	printf("EVM JIT create");
-
-	int* a = nullptr;
-	*a = 1;
-
-	return nullptr;
+	auto returnCode = engine.run(bytecode, data, static_cast<Env*>(_env));
+	evmjit_result result = {static_cast<int32_t>(returnCode), 0, nullptr};
+	if (returnCode == ReturnCode::Return && !engine.returnData.empty())
+	{
+		// TODO: Optimized returning data. Allocating memory on client side by callback function might be a good idea
+		result.returnDataSize = engine.returnData.size();
+		result.returnData = std::malloc(result.returnDataSize);
+		std::memcpy(result.returnData, engine.returnData.data(), result.returnDataSize);
+	}
+
+	return result;
 }
 
-evm_jit_return_code evm_jit_execute(evm_jit* _jit);
-
-void evm_jit_get_return_data(evm_jit* _jit, char* _return_data_offset, size_t* _return_data_size);
-
-void evm_jit_destroy(evm_jit* _jit);
-
 }
diff --git a/libevmjit/interface.h b/libevmjit/interface.h
index 1515fed86..5d9307ab2 100644
--- a/libevmjit/interface.h
+++ b/libevmjit/interface.h
@@ -1,10 +1,19 @@
 #include <stddef.h>
+#include <stdint.h>
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-int evmjit_run(void* _data, void* _env);
+typedef struct evmjit_result
+{
+	int32_t  returnCode;
+	uint64_t returnDataSize;
+	void*    returnData;
+
+} evmjit_result;
+
+evmjit_result evmjit_run(void* _data, void* _env);
 
 // JIT object opaque type
 typedef struct evm_jit evm_jit;