From 9c244ed08eb0f674637b6f0a103059de6b8534cf Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Pawe=C5=82=20Bylica?= <pawel.bylica@imapp.pl>
Date: Fri, 9 Jan 2015 16:14:45 +0100
Subject: [PATCH] Load cached object without compiling LLVM module

---
 libevmjit/Cache.cpp           | 40 ++++++++++++++++++++++++++---------
 libevmjit/Cache.h             |  1 +
 libevmjit/ExecutionEngine.cpp | 11 ++++++++--
 3 files changed, 40 insertions(+), 12 deletions(-)

diff --git a/libevmjit/Cache.cpp b/libevmjit/Cache.cpp
index a887d91e9..2311c0496 100644
--- a/libevmjit/Cache.cpp
+++ b/libevmjit/Cache.cpp
@@ -3,6 +3,7 @@
 #include <cassert>
 #include <iostream>
 #include <llvm/IR/Module.h>
+#include <llvm/IR/LLVMContext.h>
 #include <llvm/Support/Path.h>
 #include <llvm/Support/FileSystem.h>
 #include <llvm/Support/raw_os_ostream.h>
@@ -23,6 +24,32 @@ ObjectCache* Cache::getObjectCache()
 	return &objectCache;
 }
 
+namespace
+{
+	llvm::MemoryBuffer* lastObject;
+}
+
+std::unique_ptr<llvm::Module> Cache::getObject(std::string const& id)
+{
+	assert(!lastObject);
+	llvm::SmallString<256> cachePath;
+	llvm::sys::path::system_temp_directory(false, cachePath);
+	llvm::sys::path::append(cachePath, "evm_objs", id);
+
+	if (auto r = llvm::MemoryBuffer::getFile(cachePath.str(), -1, false))
+		lastObject = llvm::MemoryBuffer::getMemBufferCopy(r.get()->getBuffer());
+	else if (r.getError() != std::make_error_code(std::errc::no_such_file_or_directory))
+		std::cerr << r.getError().message(); // TODO: Add log
+
+	if (lastObject)  // if object found create fake module
+	{
+		auto module = std::unique_ptr<llvm::Module>(new llvm::Module(id, llvm::getGlobalContext()));
+		auto mainFuncType = llvm::FunctionType::get(llvm::IntegerType::get(llvm::getGlobalContext(), 32), {}, false);
+		auto func = llvm::Function::Create(mainFuncType, llvm::Function::ExternalLinkage, id, module.get());
+	}
+	return nullptr;
+}
+
 
 void ObjectCache::notifyObjectCompiled(llvm::Module const* _module, llvm::MemoryBuffer const* _object)
 {
@@ -43,16 +70,9 @@ void ObjectCache::notifyObjectCompiled(llvm::Module const* _module, llvm::Memory
 
 llvm::MemoryBuffer* ObjectCache::getObject(llvm::Module const* _module)
 {
-	auto&& id = _module->getModuleIdentifier();
-	llvm::SmallString<256> cachePath;
-	llvm::sys::path::system_temp_directory(false, cachePath);
-	llvm::sys::path::append(cachePath, "evm_objs", id);
-
-	if (auto r = llvm::MemoryBuffer::getFile(cachePath.str(), -1, false))
-		return llvm::MemoryBuffer::getMemBufferCopy(r.get()->getBuffer());
-	else if (r.getError() != std::make_error_code(std::errc::no_such_file_or_directory))
-		std::cerr << r.getError().message(); // TODO: Add log
-	return nullptr;
+	auto o = lastObject;
+	lastObject = nullptr;
+	return o;
 }
 
 }
diff --git a/libevmjit/Cache.h b/libevmjit/Cache.h
index d1027288e..1cad537cd 100644
--- a/libevmjit/Cache.h
+++ b/libevmjit/Cache.h
@@ -33,6 +33,7 @@ class Cache
 {
 public:
 	static ObjectCache* getObjectCache();
+	static std::unique_ptr<llvm::Module> getObject(std::string const& id);
 };
 
 }
diff --git a/libevmjit/ExecutionEngine.cpp b/libevmjit/ExecutionEngine.cpp
index 499312b38..7e99932c3 100644
--- a/libevmjit/ExecutionEngine.cpp
+++ b/libevmjit/ExecutionEngine.cpp
@@ -74,7 +74,13 @@ ReturnCode ExecutionEngine::run(bytes const& _code, RuntimeData* _data, Env* _en
 	}
 	else
 	{
-		auto module = Compiler({}).compile(_code, mainFuncName);
+		bool objectCacheEnabled = true;
+		auto objectCache = objectCacheEnabled ? Cache::getObjectCache() : nullptr;
+		std::unique_ptr<llvm::Module> module;
+		if (objectCache)
+			module = Cache::getObject(mainFuncName);
+		if (!module)
+			module = Compiler({}).compile(_code, mainFuncName);
 		//module->dump();
 		if (!ee)
 		{
@@ -100,7 +106,8 @@ ReturnCode ExecutionEngine::run(bytes const& _code, RuntimeData* _data, Env* _en
 			module.release();         // Successfully created llvm::ExecutionEngine takes ownership of the module
 			memoryManager.release();  // and memory manager
 
-			ee->setObjectCache(Cache::getObjectCache());
+			if (objectCache)
+				ee->setObjectCache(objectCache);
 			entryFuncPtr = (EntryFuncPtr)ee->getFunctionAddress(mainFuncName);
 		}
 		else