C++ LLGlobalVariable类代码示例

void DtoDeclareTypeInfo(TypeInfoDeclaration* tid)
{
    DtoResolveTypeInfo(tid);

    if (tid->ir.declared) return;
    tid->ir.declared = true;

    Logger::println("DtoDeclareTypeInfo(%s)", tid->toChars());
    LOG_SCOPE;

    if (Logger::enabled())
    {
        std::string mangled(tid->mangle());
        Logger::println("type = '%s'", tid->tinfo->toChars());
        Logger::println("typeinfo mangle: %s", mangled.c_str());
    }

    IrGlobal* irg = tid->ir.irGlobal;
    assert(irg->value != NULL);

    // this is a declaration of a builtin __initZ var
    if (tid->tinfo->builtinTypeInfo()) {
        LLGlobalVariable* g = isaGlobalVar(irg->value);
        g->setLinkage(llvm::GlobalValue::ExternalLinkage);
        return;
    }

    // define custom typedef
    tid->llvmDefine();
}

llvm::GlobalVariable* LLVM_D_GetRuntimeGlobal(llvm::Module* target, const char* name)
{
    LLGlobalVariable* gv = target->getNamedGlobal(name);
    if (gv) {
        return gv;
    }

    if (noruntime) {
        error("No implicit runtime calls allowed with -noruntime option enabled");
        fatal();
    }

    if (!M) {
        LLVM_D_InitRuntime();
    }

    LLGlobalVariable* g = M->getNamedGlobal(name);
    if (!g) {
        error("Runtime global '%s' was not found", name);
        fatal();
        //return NULL;
    }

    LLPointerType* t = g->getType();
    return new LLGlobalVariable(*target, t->getElementType(), g->isConstant(),
                                g->getLinkage(), NULL, g->getName());
}

void DtoResolveStruct(StructDeclaration* sd)
{
    // Make sure to resolve each struct type exactly once.
    if (sd->ir.resolved) return;
    sd->ir.resolved = true;

    Logger::println("Resolving struct type: %s (%s)", sd->toChars(), sd->loc.toChars());
    LOG_SCOPE;

    // make sure type exists
    DtoType(sd->type);

    // if it's a forward declaration, all bets are off. The type should be enough
    if (sd->sizeok != 1)
        return;

    // create the IrAggr
    IrAggr* irstruct = new IrAggr(sd);
    sd->ir.irStruct = irstruct;

    // Set up our field metadata.
    for (ArrayIter<VarDeclaration> it(sd->fields); !it.done(); it.next())
    {
        VarDeclaration* vd = it.get();
        assert(!vd->ir.irField);
        (void)new IrField(vd);
    }

    // perform definition
    bool emitGlobalData = mustDefineSymbol(sd);
    if (emitGlobalData)
    {
        // emit the initZ symbol
        LLGlobalVariable* initZ = irstruct->getInitSymbol();

        // set initZ initializer
        initZ->setInitializer(irstruct->getDefaultInit());
    }

    // emit members
    if (sd->members)
    {
        for (ArrayIter<Dsymbol> it(sd->members); !it.done(); it.next())
        {
            it.get()->codegen(Type::sir);
        }
    }

    if (emitGlobalData)
    {
        // emit typeinfo
        DtoTypeInfoOf(sd->type);
    }
}

void RTTIBuilder::push_void_array(llvm::Constant* CI, Type* valtype, Dsymbol* mangle_sym)
{
    std::string initname(mangle_sym->mangle());
    initname.append(".rtti.voidarr.data");

    LLGlobalVariable* G = new llvm::GlobalVariable(
        *gIR->module, CI->getType(), true, TYPEINFO_LINKAGE_TYPE, CI, initname);
    G->setAlignment(valtype->alignsize());

    push_void_array(getTypePaddedSize(CI->getType()), G);
}

void TypeInfoDeclaration_codegen(TypeInfoDeclaration *decl, IRState *p) {
  IF_LOG Logger::println("TypeInfoDeclaration::codegen(%s)",
                         decl->toPrettyChars());
  LOG_SCOPE;

  if (decl->ir.isDefined()) {
    return;
  }
  decl->ir.setDefined();

  std::string mangled(mangle(decl));
  IF_LOG {
    Logger::println("type = '%s'", decl->tinfo->toChars());
    Logger::println("typeinfo mangle: %s", mangled.c_str());
  }

  IrGlobal *irg = getIrGlobal(decl, true);
  irg->value = gIR->module.getGlobalVariable(mangled);
  if (irg->value) {
    irg->type = irg->value->getType()->getContainedType(0);
    assert(irg->type->isStructTy());
  } else {
    if (builtinTypeInfo(
            decl->tinfo)) { // this is a declaration of a builtin __initZ var
      irg->type = Type::dtypeinfo->type->ctype->isClass()->getMemoryLLType();
    } else {
      irg->type = LLStructType::create(gIR->context(), decl->toPrettyChars());
    }
    irg->value = new llvm::GlobalVariable(gIR->module, irg->type, true,
                                          llvm::GlobalValue::ExternalLinkage,
                                          nullptr, mangled);
  }

  emitTypeMetadata(decl);

  // this is a declaration of a builtin __initZ var
  if (builtinTypeInfo(decl->tinfo)) {
    LLGlobalVariable *g = isaGlobalVar(irg->value);
    g->setLinkage(llvm::GlobalValue::ExternalLinkage);
    return;
  }

  // define custom typedef
  LLVMDefineVisitor v;
  decl->accept(&v);
}

void RTTIBuilder::push_array(llvm::Constant * CI, uint64_t dim, Type* valtype, Dsymbol * mangle_sym)
{
	std::string tmpStr(valtype->arrayOf()->toChars());
	tmpStr.erase( remove( tmpStr.begin(), tmpStr.end(), '[' ), tmpStr.end() );
	tmpStr.erase( remove( tmpStr.begin(), tmpStr.end(), ']' ), tmpStr.end() );
	tmpStr.append("arr");

	std::string initname(mangle_sym?mangle_sym->mangle():".ldc");
    initname.append(".rtti.");
    initname.append(tmpStr);
    initname.append(".data");

    LLGlobalVariable* G = new llvm::GlobalVariable(
        *gIR->module, CI->getType(), true, TYPEINFO_LINKAGE_TYPE, CI, initname);
    G->setAlignment(valtype->alignsize());

    push_array(dim, DtoBitCast(G, DtoType(valtype->pointerTo())));
}

llvm::GlobalVariable *getRuntimeGlobal(Loc &loc, llvm::Module &target,
                                       const char *name) {
  LLGlobalVariable *gv = target.getNamedGlobal(name);
  if (gv) {
    return gv;
  }

  checkForImplicitGCCall(loc, name);

  if (!M) {
    initRuntime();
  }

  LLGlobalVariable *g = M->getNamedGlobal(name);
  if (!g) {
    error(loc, "Runtime global '%s' was not found", name);
    fatal();
    // return NULL;
  }

  LLPointerType *t = g->getType();
  return getOrCreateGlobal(loc, target, t->getElementType(), g->isConstant(),
                           g->getLinkage(), nullptr, g->getName());
}

  void visit(VarDeclaration *decl) override {
    IF_LOG Logger::println("VarDeclaration::codegen(): '%s'",
                           decl->toPrettyChars());
    LOG_SCOPE;

    if (decl->ir->isDefined()) {
      return;
    }

    if (decl->type->ty == Terror) {
      error(decl->loc, "had semantic errors when compiling");
      decl->ir->setDefined();
      return;
    }

    DtoResolveVariable(decl);
    decl->ir->setDefined();

    // just forward aliases
    if (decl->aliassym) {
      Logger::println("alias sym");
      decl->toAlias()->accept(this);
      return;
    }

    // global variable
    if (decl->isDataseg()) {
      Logger::println("data segment");

      assert(!(decl->storage_class & STCmanifest) &&
             "manifest constant being codegen'd!");
      assert(!irs->dcomputetarget);

      IrGlobal *irGlobal = getIrGlobal(decl);
      LLGlobalVariable *gvar = llvm::cast<LLGlobalVariable>(irGlobal->value);
      assert(gvar && "DtoResolveVariable should have created value");

      if (global.params.vtls && gvar->isThreadLocal() &&
          !(decl->storage_class & STCtemp)) {
        const char *p = decl->loc.toChars();
        fprintf(global.stdmsg, "%s: %s is thread local\n", p, decl->toChars());
      }

      // Check if we are defining or just declaring the global in this module.
      // If we reach here during codegen of an available_externally function,
      // new variable declarations should stay external and therefore must not
      // have an initializer.
      if (!(decl->storage_class & STCextern) && !decl->inNonRoot()) {
        // Build the initializer. Might use irGlobal->value!
        LLConstant *initVal =
            DtoConstInitializer(decl->loc, decl->type, decl->_init);

        // Cache it.
        assert(!irGlobal->constInit);
        irGlobal->constInit = initVal;

        // Set the initializer, swapping out the variable if the types do not
        // match.
        irGlobal->value = irs->setGlobalVarInitializer(gvar, initVal);

        // Finalize linkage & DLL storage class.
        const auto lwc = DtoLinkage(decl);
        setLinkage(lwc, gvar);
        if (gvar->hasDLLImportStorageClass()) {
          gvar->setDLLStorageClass(LLGlobalValue::DLLExportStorageClass);
        }

        // Also set up the debug info.
        irs->DBuilder.EmitGlobalVariable(gvar, decl);
      }

      // If this global is used from a naked function, we need to create an
      // artificial "use" for it, or it could be removed by the optimizer if
      // the only reference to it is in inline asm.
      if (irGlobal->nakedUse) {
        irs->usedArray.push_back(gvar);
      }

      IF_LOG Logger::cout() << *gvar << '\n';
    }
  }

void VarDeclaration::codegen(Ir* p)
{
    Logger::print("VarDeclaration::codegen(): %s | %s\n", toChars(), type->toChars());
    LOG_SCOPE;

    if (type->ty == Terror)
    {   error("had semantic errors when compiling");
        return;
    }

    // just forward aliases
    if (aliassym)
    {
        Logger::println("alias sym");
        toAlias()->codegen(p);
        return;
    }

    // output the parent aggregate first
    if (AggregateDeclaration* ad = isMember())
        ad->codegen(p);

    // global variable
    // taken from dmd2/structs
    if (isDataseg() || (storage_class & (STCconst | STCimmutable) && init))
    {
        Logger::println("data segment");

    #if 0 // TODO:
        assert(!(storage_class & STCmanifest) &&
            "manifest constant being codegen'd!");
    #endif

        // don't duplicate work
        if (this->ir.resolved) return;
        this->ir.resolved = true;
        this->ir.declared = true;

        this->ir.irGlobal = new IrGlobal(this);

        Logger::println("parent: %s (%s)", parent->toChars(), parent->kind());

        // not sure why this is only needed for d2
        bool _isconst = isConst() && init;

        Logger::println("Creating global variable");

        assert(!ir.initialized);
        ir.initialized = gIR->dmodule;
        std::string _name(mangle());

        LLType *_type = DtoConstInitializerType(type, init);

        // create the global variable
#if LDC_LLVM_VER >= 302
        // FIXME: clang uses a command line option for the thread model
        LLGlobalVariable* gvar = new LLGlobalVariable(*gIR->module, _type, _isconst,
                                                      DtoLinkage(this), NULL, _name, 0,
                                                      isThreadlocal() ? LLGlobalVariable::GeneralDynamicTLSModel
                                                                      : LLGlobalVariable::NotThreadLocal);
#else
        LLGlobalVariable* gvar = new LLGlobalVariable(*gIR->module, _type, _isconst,
                                                      DtoLinkage(this), NULL, _name, 0, isThreadlocal());
#endif
        this->ir.irGlobal->value = gvar;

        // Set the alignment (it is important not to use type->alignsize because
        // VarDeclarations can have an align() attribute independent of the type
        // as well).
        if (alignment != STRUCTALIGN_DEFAULT)
            gvar->setAlignment(alignment);

        if (Logger::enabled())
            Logger::cout() << *gvar << '\n';

        // if this global is used from a nested function, this is necessary or
        // optimization could potentially remove the global (if it's the only use)
        if (nakedUse)
            gIR->usedArray.push_back(DtoBitCast(gvar, getVoidPtrType()));

        // assign the initializer
        if (!(storage_class & STCextern) && mustDefineSymbol(this))
        {
            if (Logger::enabled())
            {
                Logger::println("setting initializer");
                Logger::cout() << "global: " << *gvar << '\n';
    #if 0
                Logger::cout() << "init:   " << *initVal << '\n';
    #endif
            }
            // build the initializer
            LLConstant *initVal = DtoConstInitializer(loc, type, init);

            // set the initializer
            assert(!ir.irGlobal->constInit);
            ir.irGlobal->constInit = initVal;
            gvar->setInitializer(initVal);

            // do debug info
//.........这里部分代码省略.........

void DtoResolveStruct(StructDeclaration* sd)
{
    // don't do anything if already been here
    if (sd->ir.resolved) return;
    // make sure above works :P
    sd->ir.resolved = true;

    // log what we're doing
    Logger::println("Resolving struct type: %s (%s)", sd->toChars(), sd->loc.toChars());
    LOG_SCOPE;

    // make sure type exists
    DtoType(sd->type);

    // if it's a forward declaration, all bets are off. The type should be enough
    if (sd->sizeok != 1)
        return;

    // create the IrStruct
    IrStruct* irstruct = new IrStruct(sd);
    sd->ir.irStruct = irstruct;

    // make sure all fields really get their ir field
    ArrayIter<VarDeclaration> it(sd->fields);
    for (; !it.done(); it.next())
    {
        VarDeclaration* vd = it.get();
        if (vd->ir.irField == NULL) {
            new IrField(vd);
        } else {
            IF_LOG Logger::println("struct field already exists!!!");
        }
    }

    // perform definition
    bool needs_def = mustDefineSymbol(sd);
    if (needs_def)
    {
        // emit the initZ symbol
        LLGlobalVariable* initZ = irstruct->getInitSymbol();

        // set initZ initializer
        initZ->setInitializer(irstruct->getDefaultInit());
    }

    // emit members
    if (sd->members)
    {
        ArrayIter<Dsymbol> it(*sd->members);
        while (!it.done())
        {
            Dsymbol* member = it.get();
            if (member)
                member->codegen(Type::sir);
            it.next();
        }
    }

    if (needs_def)
    {
        // emit typeinfo
        DtoTypeInfoOf(sd->type);
    }
}

void DtoResolveClass(ClassDeclaration* cd)
{
    // make sure the base classes are processed first
    ArrayIter<BaseClass> base_iter(cd->baseclasses);
    while (base_iter.more())
    {
        BaseClass* bc = base_iter.get();
        if (bc)
        {
            bc->base->codegen(Type::sir);
        }
        base_iter.next();
    }

    if (cd->ir.resolved) return;
    cd->ir.resolved = true;

    Logger::println("DtoResolveClass(%s): %s", cd->toPrettyChars(), cd->loc.toChars());
    LOG_SCOPE;

    // make sure type exists
    DtoType(cd->type);

    // create IrStruct
    assert(cd->ir.irStruct == NULL);
    IrStruct* irstruct = new IrStruct(cd);
    cd->ir.irStruct = irstruct;

    // make sure all fields really get their ir field
    ArrayIter<VarDeclaration> it(cd->fields);
    for (; !it.done(); it.next())
    {
        VarDeclaration* vd = it.get();
        if (vd->ir.irField == NULL) {
            new IrField(vd);
        } else {
            IF_LOG Logger::println("class field already exists!!!");
        }
    }

    bool needs_def = mustDefineSymbol(cd);

    // emit the ClassZ symbol
    LLGlobalVariable* ClassZ = irstruct->getClassInfoSymbol();

    // emit the interfaceInfosZ symbol if necessary
    if (cd->vtblInterfaces && cd->vtblInterfaces->dim > 0)
        irstruct->getInterfaceArraySymbol(); // initializer is applied when it's built

    // interface only emit typeinfo and classinfo
    if (cd->isInterfaceDeclaration())
    {
        irstruct->initializeInterface();
    }
    else
    {
        // emit the initZ symbol
        LLGlobalVariable* initZ = irstruct->getInitSymbol();
        // emit the vtblZ symbol
        LLGlobalVariable* vtblZ = irstruct->getVtblSymbol();

        // perform definition
        if (needs_def)
        {
            // set symbol initializers
            initZ->setInitializer(irstruct->getDefaultInit());
            vtblZ->setInitializer(irstruct->getVtblInit());
        }
    }

    // emit members
    if (cd->members)
    {
        ArrayIter<Dsymbol> it(*cd->members);
        while (!it.done())
        {
            Dsymbol* member = it.get();
            if (member)
                member->codegen(Type::sir);
            it.next();
        }
    }

    if (needs_def)
    {
        // emit typeinfo
        DtoTypeInfoOf(cd->type);

        // define classinfo
        ClassZ->setInitializer(irstruct->getClassInfoInit());
    }
}

//.........这里部分代码省略.........
    }
    // has class array?
    if (!classInits.empty())
    {
        localClassesTy = llvm::ArrayType::get(classinfoTy, classInits.size());
        localClasses = LLConstantArray::get(localClassesTy, classInits);
    }

    // These must match the values in druntime/src/object_.d
    #define MIstandalone      4
    #define MItlsctor         8
    #define MItlsdtor         0x10
    #define MIctor            0x20
    #define MIdtor            0x40
    #define MIxgetMembers     0x80
    #define MIictor           0x100
    #define MIunitTest        0x200
    #define MIimportedModules 0x400
    #define MIlocalClasses    0x800
    #define MInew             0x80000000   // it's the "new" layout

    llvm::Function* fsharedctor = build_module_shared_ctor();
    llvm::Function* fshareddtor = build_module_shared_dtor();
    llvm::Function* funittest = build_module_unittest();
    llvm::Function* fctor = build_module_ctor();
    llvm::Function* fdtor = build_module_dtor();

    unsigned flags = MInew;
    if (fctor)
        flags |= MItlsctor;
    if (fdtor)
        flags |= MItlsdtor;
    if (fsharedctor)
        flags |= MIctor;
    if (fshareddtor)
        flags |= MIdtor;
#if 0
    if (fgetmembers)
        flags |= MIxgetMembers;
    if (fictor)
        flags |= MIictor;
#endif
    if (funittest)
        flags |= MIunitTest;
    if (importedModules)
        flags |= MIimportedModules;
    if (localClasses)
        flags |= MIlocalClasses;

    if (!needmoduleinfo)
        flags |= MIstandalone;

    b.push_uint(flags); // flags
    b.push_uint(0);     // index

    if (fctor)
        b.push(fctor);
    if (fdtor)
        b.push(fdtor);
    if (fsharedctor)
        b.push(fsharedctor);
    if (fshareddtor)
        b.push(fshareddtor);
#if 0
    if (fgetmembers)
        b.push(fgetmembers);
    if (fictor)
        b.push(fictor);
#endif
    if (funittest)
        b.push(funittest);
    if (importedModules) {
        b.push_size(importInits.size());
        b.push(importedModules);
    }
    if (localClasses) {
        b.push_size(classInits.size());
        b.push(localClasses);
    }

    // Put out module name as a 0-terminated string.
    const char *name = toPrettyChars();
    const size_t len = strlen(name) + 1;
    llvm::IntegerType *it = llvm::IntegerType::getInt8Ty(gIR->context());
    llvm::ArrayType *at = llvm::ArrayType::get(it, len);
    b.push(toConstantArray(it, at, name, len, false));

    // create and set initializer
    LLGlobalVariable *moduleInfoSym = moduleInfoSymbol();
    b.finalize(moduleInfoSym->getType()->getPointerElementType(), moduleInfoSym);
    moduleInfoSym->setLinkage(llvm::GlobalValue::ExternalLinkage);

    if (global.params.isLinux) {
        build_dso_registry_calls(moduleInfoSym);
    } else {
        // build the modulereference and ctor for registering it
        LLFunction* mictor = build_module_reference_and_ctor(moduleInfoSym);
        AppendFunctionToLLVMGlobalCtorsDtors(mictor, 65535, true);
    }
}