//
// mini-llvm-cpp.cpp: C++ support classes for the mono LLVM integration
//
// (C) 2009 Novell, Inc.
//

//
// We need to override some stuff in LLVM, but this cannot be done using the C
// interface, so we have to use some C++ code here.
// The things which we override are:
// - the default JIT code manager used by LLVM doesn't allocate memory using
//   MAP_32BIT, we require it.
// - add some callbacks so we can obtain the size of methods and their exception
//   tables.
//

//
// Mono's internal header files are not C++ clean, so avoid including them if 
// possible
//

#include <stdint.h>

#include <llvm/Support/raw_ostream.h>
#include <llvm/PassManager.h>
#include <llvm/ExecutionEngine/ExecutionEngine.h>
#include <llvm/ExecutionEngine/JITMemoryManager.h>
#include <llvm/ExecutionEngine/JITEventListener.h>
#include <llvm/Target/TargetOptions.h>
#include <llvm/Target/TargetData.h>
#include <llvm/Target/TargetRegisterInfo.h>
#include <llvm/Analysis/Verifier.h>
#include <llvm/Transforms/Scalar.h>
#include <llvm/Support/CommandLine.h>
#include "llvm/Support/PassNameParser.h"
#include "llvm/Support/PrettyStackTrace.h"
#include <llvm/CodeGen/Passes.h>
#include <llvm/CodeGen/MachineFunctionPass.h>
#include <llvm/CodeGen/MachineFunction.h>
#include <llvm/CodeGen/MachineFrameInfo.h>
#include <llvm/Support/StandardPasses.h>
//#include <llvm/LinkAllPasses.h>

#include "llvm-c/Core.h"
#include "llvm-c/ExecutionEngine.h"

#include "mini-llvm-cpp.h"

#define LLVM_CHECK_VERSION(major,minor) \
	((LLVM_MAJOR_VERSION > (major)) ||									\
	 ((LLVM_MAJOR_VERSION == (major)) && (LLVM_MINOR_VERSION >= (minor))))

extern "C" void LLVMInitializeX86TargetInfo();

using namespace llvm;

class MonoJITMemoryManager : public JITMemoryManager
{
private:
	JITMemoryManager *mm;

public:
	/* Callbacks installed by mono */
	AllocCodeMemoryCb *alloc_cb;

	MonoJITMemoryManager ();
	~MonoJITMemoryManager ();

	void setMemoryWritable (void);

	void setMemoryExecutable (void);

	void AllocateGOT();

    unsigned char *getGOTBase() const {
		return mm->getGOTBase ();
    }

#if LLVM_MAJOR_VERSION == 2 && LLVM_MINOR_VERSION < 7
    void *getDlsymTable() const {
		return mm->getDlsymTable ();
    }

	void SetDlsymTable(void *ptr);
#endif

	void setPoisonMemory(bool) {
	}

	unsigned char *startFunctionBody(const Function *F, 
									 uintptr_t &ActualSize);
  
	unsigned char *allocateStub(const GlobalValue* F, unsigned StubSize,
								 unsigned Alignment);
  
	void endFunctionBody(const Function *F, unsigned char *FunctionStart,
						 unsigned char *FunctionEnd);

	unsigned char *allocateSpace(intptr_t Size, unsigned Alignment);

	uint8_t *allocateGlobal(uintptr_t Size, unsigned Alignment);
  
	void deallocateMemForFunction(const Function *F);
  
	unsigned char*startExceptionTable(const Function* F,
									  uintptr_t &ActualSize);
  
	void endExceptionTable(const Function *F, unsigned char *TableStart,
						   unsigned char *TableEnd, 
						   unsigned char* FrameRegister);

#if LLVM_MAJOR_VERSION == 2 && LLVM_MINOR_VERSION >= 7
	virtual void deallocateFunctionBody(void*) {
	}

	virtual void deallocateExceptionTable(void*) {
	}
#endif
};

MonoJITMemoryManager::MonoJITMemoryManager ()
{
#if LLVM_MAJOR_VERSION == 2 && LLVM_MINOR_VERSION <= 7
	SizeRequired = true;
#endif
	mm = JITMemoryManager::CreateDefaultMemManager ();
}

MonoJITMemoryManager::~MonoJITMemoryManager ()
{
	delete mm;
}

void
MonoJITMemoryManager::setMemoryWritable (void)
{
}

void
MonoJITMemoryManager::setMemoryExecutable (void)
{
}

void
MonoJITMemoryManager::AllocateGOT()
{
	mm->AllocateGOT ();
}

#if LLVM_MAJOR_VERSION == 2 && LLVM_MINOR_VERSION < 7  
void
MonoJITMemoryManager::SetDlsymTable(void *ptr)
{
	mm->SetDlsymTable (ptr);
}
#endif

unsigned char *
MonoJITMemoryManager::startFunctionBody(const Function *F, 
					uintptr_t &ActualSize)
{
	// FIXME: This leaks memory
	if (ActualSize == 0)
		ActualSize = 128;
	return alloc_cb (wrap (F), ActualSize);
}
  
unsigned char *
MonoJITMemoryManager::allocateStub(const GlobalValue* F, unsigned StubSize,
			   unsigned Alignment)
{
	return alloc_cb (wrap (F), StubSize);
}
  
void
MonoJITMemoryManager::endFunctionBody(const Function *F, unsigned char *FunctionStart,
				  unsigned char *FunctionEnd)
{
}

unsigned char *
MonoJITMemoryManager::allocateSpace(intptr_t Size, unsigned Alignment)
{
	return new unsigned char [Size];
}

uint8_t *
MonoJITMemoryManager::allocateGlobal(uintptr_t Size, unsigned Alignment)
{
	return new unsigned char [Size];
}

void
MonoJITMemoryManager::deallocateMemForFunction(const Function *F)
{
}
  
unsigned char*
MonoJITMemoryManager::startExceptionTable(const Function* F,
					  uintptr_t &ActualSize)
{
	return startFunctionBody(F, ActualSize);
}
  
void
MonoJITMemoryManager::endExceptionTable(const Function *F, unsigned char *TableStart,
					unsigned char *TableEnd, 
					unsigned char* FrameRegister)
{
}

class MonoJITEventListener : public JITEventListener {

public:
	FunctionEmittedCb *emitted_cb;

	MonoJITEventListener (FunctionEmittedCb *cb) {
		emitted_cb = cb;
	}

	virtual void NotifyFunctionEmitted(const Function &F,
									   void *Code, size_t Size,
									   const EmittedFunctionDetails &Details) {
		/*
		 * X86TargetMachine::setCodeModelForJIT() sets the code model to Large on amd64,
		 * which means the JIT will generate calls of the form
		 * mov reg, <imm>
		 * call *reg
		 * Our trampoline code can't patch this. Passing CodeModel::Small to createJIT
		 * doesn't seem to work, we need Default. A discussion is here:
		 * http://lists.cs.uiuc.edu/pipermail/llvmdev/2009-December/027999.html
		 * There seems to no way to get the TargeMachine used by an EE either, so we
		 * install a profiler hook and reset the code model here.
		 * This should be inside an ifdef, but we can't include our config.h either,
		 * since its definitions conflict with LLVM's config.h.
		 *
		 */
		//#if defined(TARGET_X86) || defined(TARGET_AMD64)
#ifndef LLVM_MONO_BRANCH
		/* The LLVM mono branch contains a workaround, so this is not needed */
		if (Details.MF->getTarget ().getCodeModel () == CodeModel::Large) {
			Details.MF->getTarget ().setCodeModel (CodeModel::Default);
		}
#endif
		//#endif

		emitted_cb (wrap (&F), Code, (char*)Code + Size);
	}
};

static MonoJITMemoryManager *mono_mm;
static MonoJITEventListener *mono_event_listener;

static FunctionPassManager *fpm;

void
mono_llvm_optimize_method (LLVMValueRef method)
{
	verifyFunction (*(unwrap<Function> (method)));
	fpm->run (*unwrap<Function> (method));
}

void
mono_llvm_dump_value (LLVMValueRef value)
{
	/* Same as LLVMDumpValue (), but print to stdout */
	fflush (stdout);
	outs () << (*unwrap<Value> (value));
}

/* Missing overload for building an alloca with an alignment */
LLVMValueRef
mono_llvm_build_alloca (LLVMBuilderRef builder, LLVMTypeRef Ty, 
						LLVMValueRef ArraySize,
						int alignment, const char *Name)
{
	return wrap (unwrap (builder)->Insert (new AllocaInst (unwrap (Ty), unwrap (ArraySize), alignment), Name));
}

LLVMValueRef 
mono_llvm_build_load (LLVMBuilderRef builder, LLVMValueRef PointerVal,
					  const char *Name, gboolean is_volatile)
{
	return wrap(unwrap(builder)->CreateLoad(unwrap(PointerVal), is_volatile, Name));
}

LLVMValueRef 
mono_llvm_build_aligned_load (LLVMBuilderRef builder, LLVMValueRef PointerVal,
							  const char *Name, gboolean is_volatile, int alignment)
{
	LoadInst *ins;

	ins = unwrap(builder)->CreateLoad(unwrap(PointerVal), is_volatile, Name);
	ins->setAlignment (alignment);

	return wrap(ins);
}

LLVMValueRef 
mono_llvm_build_store (LLVMBuilderRef builder, LLVMValueRef Val, LLVMValueRef PointerVal,
					  gboolean is_volatile)
{
	return wrap(unwrap(builder)->CreateStore(unwrap(Val), unwrap(PointerVal), is_volatile));
}

LLVMValueRef 
mono_llvm_build_aligned_store (LLVMBuilderRef builder, LLVMValueRef Val, LLVMValueRef PointerVal,
							   gboolean is_volatile, int alignment)
{
	StoreInst *ins;

	ins = unwrap(builder)->CreateStore(unwrap(Val), unwrap(PointerVal), is_volatile);
	ins->setAlignment (alignment);

	return wrap (ins);
}

void
mono_llvm_replace_uses_of (LLVMValueRef var, LLVMValueRef v)
{
	Value *V = ConstantExpr::getTruncOrBitCast (unwrap<Constant> (v), unwrap (var)->getType ());
	unwrap (var)->replaceAllUsesWith (V);
}

static cl::list<const PassInfo*, bool, PassNameParser>
PassList(cl::desc("Optimizations available:"));

static void
force_pass_linking (void)
{
	// Make sure the rest is linked in, but never executed
	if (getenv ("FOO") != (char*)-1)
		return;

	// This is a subset of the passes in LinkAllPasses.h
	// The utility passes and the interprocedural passes are commented out

      (void) llvm::createAAEvalPass();
      (void) llvm::createAggressiveDCEPass();
      (void) llvm::createAliasAnalysisCounterPass();
      (void) llvm::createAliasDebugger();
	  /*
      (void) llvm::createArgumentPromotionPass();
      (void) llvm::createStructRetPromotionPass();
	  */
      (void) llvm::createBasicAliasAnalysisPass();
      (void) llvm::createLibCallAliasAnalysisPass(0);
      (void) llvm::createScalarEvolutionAliasAnalysisPass();
      (void) llvm::createBlockPlacementPass();
      (void) llvm::createBreakCriticalEdgesPass();
      (void) llvm::createCFGSimplificationPass();
	  /*
      (void) llvm::createConstantMergePass();
      (void) llvm::createConstantPropagationPass();
	  */
	  /*
      (void) llvm::createDeadArgEliminationPass();
	  */
      (void) llvm::createDeadCodeEliminationPass();
      (void) llvm::createDeadInstEliminationPass();
      (void) llvm::createDeadStoreEliminationPass();
	  /*
      (void) llvm::createDeadTypeEliminationPass();
      (void) llvm::createDomOnlyPrinterPass();
      (void) llvm::createDomPrinterPass();
      (void) llvm::createDomOnlyViewerPass();
      (void) llvm::createDomViewerPass();
      (void) llvm::createEdgeProfilerPass();
      (void) llvm::createOptimalEdgeProfilerPass();
      (void) llvm::createFunctionInliningPass();
      (void) llvm::createAlwaysInlinerPass();
      (void) llvm::createGlobalDCEPass();
      (void) llvm::createGlobalOptimizerPass();
      (void) llvm::createGlobalsModRefPass();
      (void) llvm::createIPConstantPropagationPass();
      (void) llvm::createIPSCCPPass();
	  */
      (void) llvm::createIndVarSimplifyPass();
      (void) llvm::createInstructionCombiningPass();
	  /*
      (void) llvm::createInternalizePass(false);
	  */
      (void) llvm::createLCSSAPass();
      (void) llvm::createLICMPass();
      (void) llvm::createLazyValueInfoPass();
      (void) llvm::createLoopDependenceAnalysisPass();
	  /*
      (void) llvm::createLoopExtractorPass();
	  */
      (void) llvm::createLoopSimplifyPass();
      (void) llvm::createLoopStrengthReducePass();
      (void) llvm::createLoopUnrollPass();
      (void) llvm::createLoopUnswitchPass();
      (void) llvm::createLoopRotatePass();
      (void) llvm::createLowerInvokePass();
	  /*
      (void) llvm::createLowerSetJmpPass();
	  */
      (void) llvm::createLowerSwitchPass();
      (void) llvm::createNoAAPass();
	  /*
      (void) llvm::createNoProfileInfoPass();
      (void) llvm::createProfileEstimatorPass();
      (void) llvm::createProfileVerifierPass();
      (void) llvm::createProfileLoaderPass();
	  */
      (void) llvm::createPromoteMemoryToRegisterPass();
      (void) llvm::createDemoteRegisterToMemoryPass();
	  /*
      (void) llvm::createPruneEHPass();
      (void) llvm::createPostDomOnlyPrinterPass();
      (void) llvm::createPostDomPrinterPass();
      (void) llvm::createPostDomOnlyViewerPass();
      (void) llvm::createPostDomViewerPass();
	  */
      (void) llvm::createReassociatePass();
      (void) llvm::createSCCPPass();
      (void) llvm::createScalarReplAggregatesPass();
      (void) llvm::createSimplifyLibCallsPass();
	  /*
      (void) llvm::createSingleLoopExtractorPass();
      (void) llvm::createStripSymbolsPass();
      (void) llvm::createStripNonDebugSymbolsPass();
      (void) llvm::createStripDeadDebugInfoPass();
      (void) llvm::createStripDeadPrototypesPass();
      (void) llvm::createTailCallEliminationPass();
      (void) llvm::createTailDuplicationPass();
      (void) llvm::createJumpThreadingPass();
	  */
	  /*
      (void) llvm::createUnifyFunctionExitNodesPass();
	  */
      (void) llvm::createInstCountPass();
      (void) llvm::createCodeGenPreparePass();
      (void) llvm::createGVNPass();
      (void) llvm::createMemCpyOptPass();
      (void) llvm::createLoopDeletionPass();
	  /*
      (void) llvm::createPostDomTree();
      (void) llvm::createPostDomFrontier();
      (void) llvm::createInstructionNamerPass();
      (void) llvm::createPartialSpecializationPass();
      (void) llvm::createFunctionAttrsPass();
      (void) llvm::createMergeFunctionsPass();
      (void) llvm::createPrintModulePass(0);
      (void) llvm::createPrintFunctionPass("", 0);
      (void) llvm::createDbgInfoPrinterPass();
      (void) llvm::createModuleDebugInfoPrinterPass();
      (void) llvm::createPartialInliningPass();
      (void) llvm::createGEPSplitterPass();
      (void) llvm::createLintPass();
	  */
      (void) llvm::createSinkingPass();
}

LLVMExecutionEngineRef
mono_llvm_create_ee (LLVMModuleProviderRef MP, AllocCodeMemoryCb *alloc_cb, FunctionEmittedCb *emitted_cb, ExceptionTableCb *exception_cb)
{
  std::string Error;

  force_pass_linking ();

  LLVMInitializeX86Target ();
  LLVMInitializeX86TargetInfo ();

  mono_mm = new MonoJITMemoryManager ();
  mono_mm->alloc_cb = alloc_cb;

#if LLVM_MAJOR_VERSION == 2 && LLVM_MINOR_VERSION < 8
   DwarfExceptionHandling = true;
#else
   JITExceptionHandling = true;
#endif
  // PrettyStackTrace installs signal handlers which trip up libgc
  DisablePrettyStackTrace = true;

  ExecutionEngine *EE = ExecutionEngine::createJIT (unwrap (MP), &Error, mono_mm, CodeGenOpt::Default);
  if (!EE) {
	  errs () << "Unable to create LLVM ExecutionEngine: " << Error << "\n";
	  g_assert_not_reached ();
  }
  EE->InstallExceptionTableRegister (exception_cb);
  mono_event_listener = new MonoJITEventListener (emitted_cb);
  EE->RegisterJITEventListener (mono_event_listener);

  fpm = new FunctionPassManager (unwrap (MP));

  fpm->add(new TargetData(*EE->getTargetData()));

#if LLVM_CHECK_VERSION(2, 9)
  PassRegistry &Registry = *PassRegistry::getPassRegistry();
  initializeCore(Registry);
  initializeScalarOpts(Registry);
  //initializeIPO(Registry);
  initializeAnalysis(Registry);
  initializeIPA(Registry);
  initializeTransformUtils(Registry);
  initializeInstCombine(Registry);
  //initializeInstrumentation(Registry);
  initializeTarget(Registry);
#endif

  llvm::cl::ParseEnvironmentOptions("mono", "MONO_LLVM", "", false);

  if (PassList.size() > 0) {
	  /* Use the passes specified by the env variable */
	  /* Only the passes in force_pass_linking () can be used */
	  for (unsigned i = 0; i < PassList.size(); ++i) {
		  const PassInfo *PassInf = PassList[i];
		  Pass *P = 0;

		  if (PassInf->getNormalCtor())
			  P = PassInf->getNormalCtor()();
		  fpm->add (P);
	  }
  } else {
	  /* Use the same passes used by 'opt' by default, without the ipo passes */
	  const char *opts = "-simplifycfg -domtree -domfrontier -scalarrepl -instcombine -simplifycfg -basiccg -domtree -domfrontier -scalarrepl -simplify-libcalls -instcombine -simplifycfg -instcombine -simplifycfg -reassociate -domtree -loops -loop-simplify -domfrontier -loop-simplify -lcssa -loop-rotate -licm -lcssa -loop-unswitch -instcombine -scalar-evolution -loop-simplify -lcssa -iv-users -indvars -loop-deletion -loop-simplify -lcssa -loop-unroll -instcombine -memdep -gvn -memdep -memcpyopt -sccp -instcombine -domtree -memdep -dse -adce -gvn -simplifycfg -preverify -domtree -verify";
	  char **args;
	  int i;

	  args = g_strsplit (opts, " ", 1000);
	  for (i = 0; args [i]; i++)
		  ;
	  llvm::cl::ParseCommandLineOptions (i, args, "", false);
	  g_strfreev (args);

	  for (unsigned i = 0; i < PassList.size(); ++i) {
		  const PassInfo *PassInf = PassList[i];
		  Pass *P = 0;

		  if (PassInf->getNormalCtor())
			  P = PassInf->getNormalCtor()();
		  fpm->add (P);
	  }

	  /*
	  fpm->add(createInstructionCombiningPass());
	  fpm->add(createReassociatePass());
	  fpm->add(createGVNPass());
	  fpm->add(createCFGSimplificationPass());
	  */
  }

  return wrap(EE);
}

void
mono_llvm_dispose_ee (LLVMExecutionEngineRef ee)
{
	delete unwrap (ee);

	delete fpm;
}