//
// mini-llvm-cpp.cpp: C++ support classes for the mono LLVM integration
//
// (C) 2009-2011 Novell, Inc.
// Copyright 2011 Xamarin, Inc (http://www.xamarin.com)
//

//
// 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 "config.h"

#include <stdint.h>

#include <llvm/Support/raw_ostream.h>
#include <llvm/Support/Host.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/TargetRegisterInfo.h>
#include <llvm/IR/Verifier.h>
#include <llvm/Analysis/Passes.h>
#include <llvm/Transforms/Scalar.h>
#include <llvm/Support/CommandLine.h>
#include "llvm/IR/LegacyPassNameParser.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/IR/Function.h>
#include <llvm/IR/IRBuilder.h>
#include <llvm/IR/Module.h>
//#include <llvm/LinkAllPasses.h>

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

#include "mini-llvm-cpp.h"

// extern "C" void LLVMInitializeARMTargetInfo();
// extern "C" void LLVMInitializeARMTarget ();
// extern "C" void LLVMInitializeARMTargetMC ();

using namespace llvm;

#ifndef MONO_CROSS_COMPILE

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

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

	MonoJITMemoryManager ();
	~MonoJITMemoryManager ();

	void setMemoryWritable (void);

	void setMemoryExecutable (void);

	void AllocateGOT();

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

	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);

	virtual void deallocateFunctionBody(void*) {
	}

	virtual void deallocateExceptionTable(void*) {
	}

	virtual uint8_t *allocateCodeSection(uintptr_t Size, unsigned Alignment, unsigned SectionID,
										 StringRef SectionName) {
		// FIXME:
		assert(0);
		return NULL;
	}

	virtual uint8_t *allocateDataSection(uintptr_t Size, unsigned Alignment, unsigned SectionID,
										 StringRef SectionName, bool IsReadOnly) {
		// FIXME:
		assert(0);
		return NULL;
	}

	virtual bool applyPermissions(std::string*) {
		// FIXME:
		assert(0);
		return false;
	}

	virtual bool finalizeMemory(std::string *ErrMsg = 0) {
		// FIXME:
		assert(0);
		return false;
	}

	virtual void* getPointerToNamedFunction(const std::string &Name, bool AbortOnFailure) {
		void *res;
		char *err;

		err = dlsym_cb (Name.c_str (), &res);
		if (err) {
			outs () << "Unable to resolve: " << Name << ": " << err << "\n";
			assert(0);
			return NULL;
		}
		return res;
	}
};

MonoJITMemoryManager::MonoJITMemoryManager ()
{
	mm = JITMemoryManager::CreateDefaultMemManager ();
}

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

void
MonoJITMemoryManager::setMemoryWritable (void)
{
}

void
MonoJITMemoryManager::setMemoryExecutable (void)
{
}

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

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)
{
}

#else

class MonoJITMemoryManager {
};

#endif /* !MONO_CROSS_COMPILE */

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.
		 * The LLVM mono branch contains a workaround.
		 */
		emitted_cb (wrap (&F), Code, (char*)Code + Size);
	}
};

class MonoEE {
public:
	ExecutionEngine *EE;
	MonoJITMemoryManager *mm;
	MonoJITEventListener *listener;
	FunctionPassManager *fpm;
};

void
mono_llvm_optimize_method (MonoEERef eeref, LLVMValueRef method)
{
	MonoEE *mono_ee = (MonoEE*)eeref;

	/*
	 * The verifier does some checks on the whole module, leading to quadratic behavior.
	 */
	//verifyFunction (*(unwrap<Function> (method)));
	mono_ee->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, BarrierKind barrier)
{
	LoadInst *ins = unwrap(builder)->CreateLoad(unwrap(PointerVal), is_volatile, Name);

	switch (barrier) {
	case LLVM_BARRIER_NONE:
		break;
	case LLVM_BARRIER_ACQ:
		ins->setOrdering(Acquire);
		break;
	case LLVM_BARRIER_SEQ:
		ins->setOrdering(SequentiallyConsistent);
		break;
	default:
		g_assert_not_reached ();
		break;
	}

	return wrap(ins);
}

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, BarrierKind barrier)
{
	StoreInst *ins = unwrap(builder)->CreateStore(unwrap(Val), unwrap(PointerVal), is_volatile);

	switch (barrier) {
	case LLVM_BARRIER_NONE:
		break;
	case LLVM_BARRIER_REL:
		ins->setOrdering(Release);
		break;
	case LLVM_BARRIER_SEQ:
		ins->setOrdering(SequentiallyConsistent);
		break;
	default:
		g_assert_not_reached ();
		break;
	}

	return wrap(ins);
}

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);
}

LLVMValueRef
mono_llvm_build_cmpxchg (LLVMBuilderRef builder, LLVMValueRef ptr, LLVMValueRef cmp, LLVMValueRef val)
{
	AtomicCmpXchgInst *ins;

	ins = unwrap(builder)->CreateAtomicCmpXchg (unwrap(ptr), unwrap (cmp), unwrap (val), SequentiallyConsistent, SequentiallyConsistent);
	return wrap (ins);
}

LLVMValueRef
mono_llvm_build_atomic_rmw (LLVMBuilderRef builder, AtomicRMWOp op, LLVMValueRef ptr, LLVMValueRef val)
{
	AtomicRMWInst::BinOp aop = AtomicRMWInst::Xchg;
	AtomicRMWInst *ins;

	switch (op) {
	case LLVM_ATOMICRMW_OP_XCHG:
		aop = AtomicRMWInst::Xchg;
		break;
	case LLVM_ATOMICRMW_OP_ADD:
		aop = AtomicRMWInst::Add;
		break;
	default:
		g_assert_not_reached ();
		break;
	}

	ins = unwrap (builder)->CreateAtomicRMW (aop, unwrap (ptr), unwrap (val), SequentiallyConsistent);
	return wrap (ins);
}

LLVMValueRef
mono_llvm_build_fence (LLVMBuilderRef builder, BarrierKind kind)
{
	FenceInst *ins;
	AtomicOrdering ordering;

	g_assert (kind != LLVM_BARRIER_NONE);

	switch (kind) {
	case LLVM_BARRIER_ACQ:
		ordering = Acquire;
		break;
	case LLVM_BARRIER_REL:
		ordering = Release;
		break;
	case LLVM_BARRIER_SEQ:
		ordering = SequentiallyConsistent;
		break;
	default:
		g_assert_not_reached ();
		break;
	}

	ins = unwrap (builder)->CreateFence (ordering);
	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 (g_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();
}

#ifndef MONO_CROSS_COMPILE

static gboolean inited;

static void
init_llvm (void)
{
	if (inited)
		return;

  force_pass_linking ();

#ifdef TARGET_ARM
  LLVMInitializeARMTarget ();
  LLVMInitializeARMTargetInfo ();
  LLVMInitializeARMTargetMC ();
#else
  LLVMInitializeX86Target ();
  LLVMInitializeX86TargetInfo ();
  LLVMInitializeX86TargetMC ();
#endif

  PassRegistry &Registry = *PassRegistry::getPassRegistry();
  initializeCore(Registry);
  initializeScalarOpts(Registry);
  initializeAnalysis(Registry);
  initializeIPA(Registry);
  initializeTransformUtils(Registry);
  initializeInstCombine(Registry);
  initializeTarget(Registry);

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

  inited = true;
}

MonoEERef
mono_llvm_create_ee (LLVMModuleProviderRef MP, AllocCodeMemoryCb *alloc_cb, FunctionEmittedCb *emitted_cb, ExceptionTableCb *exception_cb, DlSymCb *dlsym_cb, LLVMExecutionEngineRef *ee)
{
  std::string Error;
  MonoEE *mono_ee;

  init_llvm ();

  mono_ee = new MonoEE ();

  MonoJITMemoryManager *mono_mm = new MonoJITMemoryManager ();
  mono_mm->alloc_cb = alloc_cb;
  mono_mm->dlsym_cb = dlsym_cb;
  mono_ee->mm = mono_mm;

  /*
   * The Default code model doesn't seem to work on amd64,
   * test_0_fields_with_big_offsets (among others) crashes, because LLVM tries to call
   * memset using a normal pcrel code which is in 32bit memory, while memset isn't.
   */

  TargetOptions opts;
  opts.JITExceptionHandling = 1;

  StringRef cpu_name = sys::getHostCPUName ();

  // EngineBuilder no longer has a copy assignment operator (?)
  std::unique_ptr<Module> Owner(unwrap(MP));
  EngineBuilder b (std::move(Owner));
#ifdef TARGET_AMD64
  ExecutionEngine *EE = b.setJITMemoryManager (mono_mm).setTargetOptions (opts).setAllocateGVsWithCode (true).setMCPU (cpu_name).setCodeModel (CodeModel::Large).create ();
#else
  ExecutionEngine *EE = b.setJITMemoryManager (mono_mm).setTargetOptions (opts).setAllocateGVsWithCode (true).setMCPU (cpu_name).create ();
#endif

  g_assert (EE);
  mono_ee->EE = EE;

  EE->InstallExceptionTableRegister (exception_cb);
  MonoJITEventListener *listener = new MonoJITEventListener (emitted_cb);
  EE->RegisterJITEventListener (listener);
  mono_ee->listener = listener;

  FunctionPassManager *fpm = new FunctionPassManager (unwrap (MP));
  mono_ee->fpm = fpm;

  fpm->add(new DataLayoutPass(*EE->getDataLayout()));

  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 -domtree -domfrontier -scalarrepl -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";
	  char **args;
	  int i;

	  args = g_strsplit (opts, " ", 1000);
	  for (i = 0; args [i]; i++)
		  ;
	  llvm::cl::ParseCommandLineOptions (i, args, "");
	  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()();
		  g_assert (P->getPassKind () == llvm::PT_Function || P->getPassKind () == llvm::PT_Loop);
		  fpm->add (P);
	  }

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

  *ee = wrap (EE);

  return mono_ee;
}

void
mono_llvm_dispose_ee (MonoEERef *eeref)
{
	MonoEE *mono_ee = (MonoEE*)eeref;

	delete mono_ee->EE;
	delete mono_ee->fpm;
	//delete mono_ee->mm;
	delete mono_ee->listener;
	delete mono_ee;
}

#else

MonoEERef
mono_llvm_create_ee (LLVMModuleProviderRef MP, AllocCodeMemoryCb *alloc_cb, FunctionEmittedCb *emitted_cb, ExceptionTableCb *exception_cb, DlSymCb *dlsym_cb, LLVMExecutionEngineRef *ee)
{
	g_assert_not_reached ();
	return NULL;
}

void
mono_llvm_dispose_ee (MonoEERef *eeref)
{
	g_assert_not_reached ();
}

/* Not linked in */
void
LLVMAddGlobalMapping(LLVMExecutionEngineRef EE, LLVMValueRef Global,
					 void* Addr)
{
	g_assert_not_reached ();
}

void*
LLVMGetPointerToGlobal(LLVMExecutionEngineRef EE, LLVMValueRef Global)
{
	g_assert_not_reached ();
	return NULL;
}

#endif /* !MONO_CROSS_COMPILE */