From 40f9938b80ff4c66abdc9e2595f3a43292068090 Mon Sep 17 00:00:00 2001
From: Alex Beregszaszi <alex@rtfs.hu>
Date: Tue, 16 Jan 2018 13:59:34 +0000
Subject: [PATCH 1/2] EEI: implement getReturnDataSize and returnDataCopy

---
 src/eei.cpp | 33 ++++++++++++++++++++++++++++++---
 src/eei.h   |  1 +
 2 files changed, 31 insertions(+), 3 deletions(-)

diff --git a/src/eei.cpp b/src/eei.cpp
index 0a6a2ec12..63768bfbb 100644
--- a/src/eei.cpp
+++ b/src/eei.cpp
@@ -161,7 +161,7 @@ namespace HeraVM {
 
     if (import->base == Name("getCallDataSize")) {
       HERA_DEBUG << "callDataSize\n";
-      return Literal((uint32_t)msg.input_size);
+      return Literal(static_cast<uint32_t>(msg.input_size));
     }
 
     if (import->base == Name("callDataCopy")) {
@@ -212,7 +212,7 @@ namespace HeraVM {
     if (import->base == Name("getCodeSize")) {
       HERA_DEBUG << "getCodeSize\n";
 
-      return Literal((uint32_t)code.size());
+      return Literal(static_cast<uint32_t>(code.size()));
     }
 
     if (import->base == Name("externalCodeCopy")) {
@@ -243,7 +243,7 @@ namespace HeraVM {
       evm_address address = loadUint160(addressOffset);
       size_t code_size = context->fn_table->get_code(NULL, context, &address);
 
-      return Literal((uint32_t)code_size);
+      return Literal(static_cast<uint32_t>(code_size));
     }
 
     if (import->base == Name("getBlockCoinbase")) {
@@ -405,6 +405,23 @@ namespace HeraVM {
       return Literal();
     }
 
+    if (import->base == Name("getReturnDataSize")) {
+      HERA_DEBUG << "getReturnDataSize\n";
+      return Literal(static_cast<uint32_t>(lastReturnData.size()));
+    }
+
+    if (import->base == Name("returnDataCopy")) {
+      uint32_t dataOffset = arguments[0].geti32();
+      uint32_t offset = arguments[1].geti32();
+      uint32_t size = arguments[2].geti32();
+
+      HERA_DEBUG << "returnDataCopy " << hex << offset << " " << size << dec << "\n";
+
+      storeMemory(lastReturnData, dataOffset, offset, size);
+
+      return Literal();
+    }
+
     if (
       import->base == Name("call") ||
       import->base == Name("callCode") ||
@@ -489,6 +506,10 @@ namespace HeraVM {
         vector<uint8_t> result(call_result.output_data, call_result.output_data + call_result.output_size);
         result.resize(resultLength);
         storeMemory(result, 0, resultOffset, resultLength);
+
+        lastReturnData.assign(call_result.output_data, call_result.output_data + call_result.output_size);
+      } else {
+        lastReturnData.clear();
       }
 
       if (call_result.release)
@@ -535,6 +556,12 @@ namespace HeraVM {
       context->fn_table->call(&create_result, context, &create_message);
       storeUint160(create_result.create_address, resultOffset);
 
+      if (create_result.output_data) {
+        lastReturnData.assign(create_result.output_data, create_result.output_data + create_result.output_size);
+      } else {
+        lastReturnData.clear();
+      }
+
       if (create_result.release)
         create_result.release(&create_result);
 
diff --git a/src/eei.h b/src/eei.h
index 22f625d9b..e98bdb495 100644
--- a/src/eei.h
+++ b/src/eei.h
@@ -111,6 +111,7 @@ struct EthereumInterface : ShellExternalInterface {
   struct evm_context* context = nullptr;
   std::vector<uint8_t> const& code;
   struct evm_message const& msg;
+  std::vector<uint8_t> lastReturnData;
   ExecutionResult & result;
 };
 

From 76db892c5dc5d659585da37dae2acff8c896a085 Mon Sep 17 00:00:00 2001
From: Alex Beregszaszi <alex@rtfs.hu>
Date: Tue, 16 Jan 2018 17:56:17 +0000
Subject: [PATCH 2/2] EEI: on create failure the resultOffset should not be
 written to

---
 src/eei.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/eei.cpp b/src/eei.cpp
index 63768bfbb..1a6223e4a 100644
--- a/src/eei.cpp
+++ b/src/eei.cpp
@@ -554,7 +554,8 @@ namespace HeraVM {
 
       evm_result create_result;
       context->fn_table->call(&create_result, context, &create_message);
-      storeUint160(create_result.create_address, resultOffset);
+      if (create_result.status_code == EVM_SUCCESS)
+        storeUint160(create_result.create_address, resultOffset);
 
       if (create_result.output_data) {
         lastReturnData.assign(create_result.output_data, create_result.output_data + create_result.output_size);