From a23bf59c46dae7aa25c4763c6122d0822c88abc7 Mon Sep 17 00:00:00 2001
From: Josh Blum
Date: Thu, 1 Aug 2013 01:12:24 -0700
Subject: gras: jit factory api + unit tests

---
 lib/jit_factory.cpp | 158 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 158 insertions(+)
 create mode 100644 lib/jit_factory.cpp

(limited to 'lib/jit_factory.cpp')

diff --git a/lib/jit_factory.cpp b/lib/jit_factory.cpp
new file mode 100644
index 0000000..cdcfc03
--- /dev/null
+++ b/lib/jit_factory.cpp
@@ -0,0 +1,158 @@
+// Copyright (C) by Josh Blum. See LICENSE.txt for licensing information.
+
+#include <gras/factory.hpp>
+#include <stdexcept>
+
+#ifdef CLANG_EXECUTABLE
+
+#include <llvm/LLVMContext.h>
+#include <llvm/Support/TargetSelect.h>
+#include <llvm/Bitcode/ReaderWriter.h>
+#include <llvm/ExecutionEngine/ExecutionEngine.h>
+#include <llvm/Support/MemoryBuffer.h>
+#include <llvm/ExecutionEngine/JIT.h>
+#include <llvm/Support/system_error.h>
+#include <llvm/Module.h>
+
+#include <boost/foreach.hpp>
+#include <boost/format.hpp>
+#include <boost/thread/mutex.hpp>
+#include <stdexcept>
+#include <iostream>
+#include <cstdio>
+#include <fstream>
+#include <map>
+
+/***********************************************************************
+ * Helper function to call a clang compliation
+ **********************************************************************/
+static std::string call_clang(const std::string &source, const std::vector<std::string> &flags)
+{
+    //make up bitcode file path
+    char bitcode_file[L_tmpnam];
+    std::tmpnam(bitcode_file);
+
+    //write source to tmp file
+    char source_file[L_tmpnam];
+    std::tmpnam(source_file);
+    std::ofstream source_fstream(source_file);
+    source_fstream << source;
+    source_fstream.close();
+
+    //begin command setup
+    std::vector<std::string> cmd;
+    cmd.push_back(BOOST_STRINGIZE(CLANG_EXECUTABLE));
+    cmd.push_back("-emit-llvm");
+
+    //inject source
+    cmd.push_back("-c");
+    cmd.push_back("-x");
+    cmd.push_back("c++");
+    cmd.push_back(source_file);
+
+    //inject output
+    cmd.push_back("-o");
+    cmd.push_back(bitcode_file);
+
+    //inject args...
+    BOOST_FOREACH(const std::string &flag, flags)
+    {
+        cmd.push_back(flag.c_str());
+    }
+
+    //format command string
+    std::string command;
+    BOOST_FOREACH(const std::string &c, cmd)
+    {
+        command += c + " ";
+    }
+    std::cout << "  " << command << std::endl;
+    const int ret = system(command.c_str());
+    if (ret != 0)
+    {
+        throw std::runtime_error("GRAS compiler: error system exec clang");
+    }
+
+    //readback bitcode for result
+    std::ifstream bitcode_fstream(bitcode_file);
+    return std::string((std::istreambuf_iterator<char>(bitcode_fstream)), std::istreambuf_iterator<char>());
+}
+
+/***********************************************************************
+ * Storage for execution engines
+ **********************************************************************/
+struct ExecutionEngineMonitor
+{
+    ExecutionEngineMonitor(void)
+    {
+        boost::mutex::scoped_lock l(mutex);
+    }
+
+    ~ExecutionEngineMonitor(void)
+    {
+        boost::mutex::scoped_lock l(mutex);
+        for (size_t i = 0; i < ees.size(); i++)
+        {
+            ees[i]->runStaticConstructorsDestructors(true);
+            ees[i].reset();
+        }
+        ees.clear();
+    }
+
+    void add(boost::shared_ptr<llvm::ExecutionEngine> ee)
+    {
+        boost::mutex::scoped_lock l(mutex);
+        ee->runStaticConstructorsDestructors(false);
+        ees.push_back(ee);
+    }
+
+    llvm::LLVMContext &get_context(void)
+    {
+        return context;
+    }
+
+    boost::mutex mutex;
+    llvm::LLVMContext context;
+    std::vector<boost::shared_ptr<llvm::ExecutionEngine> > ees;
+};
+
+static ExecutionEngineMonitor &get_eemon(void)
+{
+    static ExecutionEngineMonitor eemon;
+    return eemon;
+}
+
+/***********************************************************************
+ * factory compile implementation
+ **********************************************************************/
+void gras::jit_factory(const std::string &source, const std::vector<std::string> &flags)
+{
+    std::cout << "GRAS compiler: compile source into bitcode..." << std::endl;
+    const std::string bitcode = call_clang(source, flags);
+
+    llvm::InitializeNativeTarget();
+    llvm::llvm_start_multithreaded();
+    std::string error;
+
+    //create a memory buffer from the bitcode
+    boost::shared_ptr<llvm::MemoryBuffer> buffer(llvm::MemoryBuffer::getMemBuffer(bitcode));
+
+    //parse the bitcode into a module
+    llvm::Module *module = llvm::ParseBitcodeFile(buffer.get(), get_eemon().get_context(), &error);
+    if (not error.empty()) throw std::runtime_error("GRAS compiler: ParseBitcodeFile " + error);
+
+    //create execution engine
+    boost::shared_ptr<llvm::ExecutionEngine> ee(llvm::ExecutionEngine::create(module, false, &error));
+    if (not error.empty()) throw std::runtime_error("GRAS compiler: ExecutionEngine " + error);
+    std::cout << "GRAS compiler: execute static constructors..." << std::endl;
+    get_eemon().add(ee);
+}
+
+#else //CLANG_EXECUTABLE
+
+void Factory::compile(const std::string &, const std::vector<std::string> &)
+{
+    throw std::runtime_error("GRAS compiler not built with Clang support!");
+}
+
+#endif //CLANG_EXECUTABLE
-- 
cgit