/*
 * Copyright (c) 2015 Andrew Kelley
 *
 * This file is part of zig, which is MIT licensed.
 * See http://opensource.org/licenses/MIT
 */

#include "zig_llvm.hpp"

/*
 * The point of this file is to contain all the LLVM C++ API interaction so that:
 * 1. The compile time of other files is kept under control.
 * 2. Provide a C interface to the LLVM functions we need for self-hosting purposes.
 * 3. Prevent C++ from infecting the rest of the project.
 */

#include <llvm/InitializePasses.h>
#include <llvm/PassRegistry.h>
#include <llvm/MC/SubtargetFeature.h>
#include <llvm/Support/raw_ostream.h>
#include <llvm/Support/FileSystem.h>
#include <llvm/Target/TargetMachine.h>
#include <llvm/IR/LegacyPassManager.h>
#include <llvm/IR/Module.h>
#include <llvm/IR/Verifier.h>
#include <llvm/IR/Instructions.h>
#include <llvm/IR/IRBuilder.h>
#include <llvm/IR/DIBuilder.h>
#include <llvm/IR/DiagnosticInfo.h>
#include <llvm/Analysis/TargetLibraryInfo.h>
#include <llvm/Analysis/TargetTransformInfo.h>
#include <llvm/Transforms/IPO.h>
#include <llvm/Transforms/IPO/PassManagerBuilder.h>
#include <llvm/Transforms/Scalar.h>

using namespace llvm;

void LLVMZigInitializeLoopStrengthReducePass(LLVMPassRegistryRef R) {
    initializeLoopStrengthReducePass(*unwrap(R));
}

void LLVMZigInitializeLowerIntrinsicsPass(LLVMPassRegistryRef R) {
    initializeLowerIntrinsicsPass(*unwrap(R));
}

void LLVMZigInitializeUnreachableBlockElimPass(LLVMPassRegistryRef R) {
    initializeUnreachableBlockElimPass(*unwrap(R));
}

char *LLVMZigGetHostCPUName(void) {
    std::string str = sys::getHostCPUName();
    return strdup(str.c_str());
}

char *LLVMZigGetNativeFeatures(void) {
    SubtargetFeatures features;

    StringMap<bool> host_features;
    if (sys::getHostCPUFeatures(host_features)) {
        for (auto &F : host_features)
            features.AddFeature(F.first(), F.second);
    }

    return strdup(features.getString().c_str());
}

static void addAddDiscriminatorsPass(const PassManagerBuilder &Builder, legacy::PassManagerBase &PM) {
  PM.add(createAddDiscriminatorsPass());
}


void LLVMZigOptimizeModule(LLVMTargetMachineRef targ_machine_ref, LLVMModuleRef module_ref) {
    TargetMachine* target_machine = reinterpret_cast<TargetMachine*>(targ_machine_ref);
    Module* module = unwrap(module_ref);
    TargetLibraryInfoImpl tlii(Triple(module->getTargetTriple()));

    PassManagerBuilder *PMBuilder = new PassManagerBuilder();
    PMBuilder->OptLevel = target_machine->getOptLevel();
    PMBuilder->SizeLevel = 0;
    PMBuilder->BBVectorize = true;
    PMBuilder->SLPVectorize = true;
    PMBuilder->LoopVectorize = true;

    PMBuilder->DisableUnitAtATime = false;
    PMBuilder->DisableUnrollLoops = false;
    PMBuilder->MergeFunctions = true;
    PMBuilder->PrepareForLTO = true;
    PMBuilder->RerollLoops = true;

    PMBuilder->addExtension(PassManagerBuilder::EP_EarlyAsPossible, addAddDiscriminatorsPass);

    PMBuilder->LibraryInfo = &tlii;

    PMBuilder->Inliner = createFunctionInliningPass(PMBuilder->OptLevel, PMBuilder->SizeLevel);

    // Set up the per-function pass manager.
    legacy::FunctionPassManager *FPM = new legacy::FunctionPassManager(module);
    FPM->add(createTargetTransformInfoWrapperPass(target_machine->getTargetIRAnalysis()));
#ifndef NDEBUG
    bool verify_module = true;
#else
    bool verify_module = false;
#endif
    if (verify_module) {
        FPM->add(createVerifierPass());
    }
    PMBuilder->populateFunctionPassManager(*FPM);

    // Set up the per-module pass manager.
    legacy::PassManager *MPM = new legacy::PassManager();
    MPM->add(createTargetTransformInfoWrapperPass(target_machine->getTargetIRAnalysis()));

    PMBuilder->populateModulePassManager(*MPM);


    // run per function optimization passes
    FPM->doInitialization();
    for (Function &F : *module)
      if (!F.isDeclaration())
        FPM->run(F);
    FPM->doFinalization();

    // run per module optimization passes
    MPM->run(*module);
}

LLVMValueRef LLVMZigBuildCall(LLVMBuilderRef B, LLVMValueRef Fn, LLVMValueRef *Args,
        unsigned NumArgs, unsigned CC, const char *Name)
{
    CallInst *call_inst = CallInst::Create(unwrap(Fn), makeArrayRef(unwrap(Args), NumArgs), Name);
    call_inst->setCallingConv(CC);
    return wrap(unwrap(B)->Insert(call_inst));
}

LLVMZigDIType *LLVMZigCreateDebugPointerType(LLVMZigDIBuilder *dibuilder, LLVMZigDIType *pointee_type,
        uint64_t size_in_bits, uint64_t align_in_bits, const char *name)
{
    DIType *di_type = reinterpret_cast<DIBuilder*>(dibuilder)->createPointerType(
            reinterpret_cast<DIType*>(pointee_type), size_in_bits, align_in_bits, name);
    return reinterpret_cast<LLVMZigDIType*>(di_type);
}

LLVMZigDIType *LLVMZigCreateDebugBasicType(LLVMZigDIBuilder *dibuilder, const char *name,
        uint64_t size_in_bits, uint64_t align_in_bits, unsigned encoding)
{
    DIType *di_type = reinterpret_cast<DIBuilder*>(dibuilder)->createBasicType(
            name, size_in_bits, align_in_bits, encoding);
    return reinterpret_cast<LLVMZigDIType*>(di_type);
}

unsigned LLVMZigEncoding_DW_ATE_unsigned(void) {
    return dwarf::DW_ATE_unsigned;
}

unsigned LLVMZigEncoding_DW_ATE_signed(void) {
    return dwarf::DW_ATE_signed;
}

unsigned LLVMZigLang_DW_LANG_C99(void) {
    return dwarf::DW_LANG_C99;
}

LLVMZigDIBuilder *LLVMZigCreateDIBuilder(LLVMModuleRef module, bool allow_unresolved) {
    DIBuilder *di_builder = new DIBuilder(*llvm::unwrap(module), allow_unresolved);
    return reinterpret_cast<LLVMZigDIBuilder *>(di_builder);
}

void LLVMZigSetCurrentDebugLocation(LLVMBuilderRef builder, int line, int column, LLVMZigDIScope *scope) {
    unwrap(builder)->SetCurrentDebugLocation(llvm::DebugLoc::get(
                line, column, reinterpret_cast<DIScope*>(scope)));
}


LLVMZigDILexicalBlock *LLVMZigCreateLexicalBlock(LLVMZigDIBuilder *dbuilder, LLVMZigDIScope *scope,
        LLVMZigDIFile *file, unsigned line, unsigned col)
{
    DILexicalBlock *result = reinterpret_cast<DIBuilder*>(dbuilder)->createLexicalBlock(
            reinterpret_cast<DIScope*>(scope),
            reinterpret_cast<DIFile*>(file),
            line,
            col);
    return reinterpret_cast<LLVMZigDILexicalBlock*>(result);
}

LLVMZigDIScope *LLVMZigLexicalBlockToScope(LLVMZigDILexicalBlock *lexical_block) {
    DIScope *scope = reinterpret_cast<DILexicalBlock*>(lexical_block);
    return reinterpret_cast<LLVMZigDIScope*>(scope);
}

LLVMZigDIScope *LLVMZigCompileUnitToScope(LLVMZigDICompileUnit *compile_unit) {
    DIScope *scope = reinterpret_cast<DICompileUnit*>(compile_unit);
    return reinterpret_cast<LLVMZigDIScope*>(scope);
}

LLVMZigDIScope *LLVMZigFileToScope(LLVMZigDIFile *difile) {
    DIScope *scope = reinterpret_cast<DIFile*>(difile);
    return reinterpret_cast<LLVMZigDIScope*>(scope);
}

LLVMZigDIScope *LLVMZigSubprogramToScope(LLVMZigDISubprogram *subprogram) {
    DIScope *scope = reinterpret_cast<DISubprogram*>(subprogram);
    return reinterpret_cast<LLVMZigDIScope*>(scope);
}

LLVMZigDICompileUnit *LLVMZigCreateCompileUnit(LLVMZigDIBuilder *dibuilder,
        unsigned lang, const char *file, const char *dir, const char *producer,
        bool is_optimized, const char *flags, unsigned runtime_version, const char *split_name,
        uint64_t dwo_id, bool emit_debug_info)
{
    DICompileUnit *result = reinterpret_cast<DIBuilder*>(dibuilder)->createCompileUnit(
            lang, file, dir, producer, is_optimized, flags, runtime_version, split_name,
            DIBuilder::FullDebug, dwo_id, emit_debug_info);
    return reinterpret_cast<LLVMZigDICompileUnit*>(result);
}

LLVMZigDIFile *LLVMZigCreateFile(LLVMZigDIBuilder *dibuilder, const char *filename, const char *directory) {
    DIFile *result = reinterpret_cast<DIBuilder*>(dibuilder)->createFile(filename, directory);
    return reinterpret_cast<LLVMZigDIFile*>(result);
}

LLVMZigDISubprogram *LLVMZigCreateFunction(LLVMZigDIBuilder *dibuilder, LLVMZigDIScope *scope,
        const char *name, const char *linkage_name, LLVMZigDIFile *file, unsigned lineno,
        LLVMZigDISubroutineType *ty, bool is_local_to_unit, bool is_definition, unsigned scope_line,
        unsigned flags, bool is_optimized, LLVMValueRef function)
{
    llvm::Function *unwrapped_function = reinterpret_cast<llvm::Function*>(unwrap(function));
    DISubprogram *result = reinterpret_cast<DIBuilder*>(dibuilder)->createFunction(
            reinterpret_cast<DIScope*>(scope),
            name, linkage_name,
            reinterpret_cast<DIFile*>(file),
            lineno,
            reinterpret_cast<DISubroutineType*>(ty),
            is_local_to_unit, is_definition, scope_line, flags, is_optimized, unwrapped_function);
    return reinterpret_cast<LLVMZigDISubprogram*>(result);
}

void LLVMZigDIBuilderFinalize(LLVMZigDIBuilder *dibuilder) {
    reinterpret_cast<DIBuilder*>(dibuilder)->finalize();
}