view gen/functions.cpp @ 1650:40bd4a0d4870

Update to work with LLVM 2.7. Removed use of dyn_cast, llvm no compiles without exceptions and rtti by default. We do need exceptions for the libconfig stuff, but rtti isn't necessary (anymore). Debug info needs to be rewritten, as in LLVM 2.7 the format has completely changed. To have something to look at while rewriting, the old code has been wrapped inside #ifndef DISABLE_DEBUG_INFO , this means that you have to define this to compile at the moment. Updated tango 0.99.9 patch to include updated EH runtime code, which is needed for LLVM 2.7 as well.
author Tomas Lindquist Olsen
date Wed, 19 May 2010 12:42:32 +0200
parents 207a8a438dea
children
line wrap: on
line source
#include "gen/llvm.h"
#include "llvm/Support/CFG.h"
#include "llvm/Intrinsics.h"

#include "mtype.h"
#include "aggregate.h"
#include "init.h"
#include "declaration.h"
#include "template.h"
#include "module.h"
#include "statement.h"

#include "gen/irstate.h"
#include "gen/tollvm.h"
#include "gen/llvmhelpers.h"
#include "gen/runtime.h"
#include "gen/arrays.h"
#include "gen/logger.h"
#include "gen/functions.h"
#include "gen/todebug.h"
#include "gen/classes.h"
#include "gen/dvalue.h"
#include "gen/abi.h"
#include "gen/nested.h"

using namespace llvm::Attribute;

const llvm::FunctionType* DtoFunctionType(Type* type, Type* thistype, Type* nesttype, bool ismain)
{
    if (Logger::enabled())
        Logger::println("DtoFunctionType(%s)", type->toChars());
    LOG_SCOPE

    // sanity check
    assert(type->ty == Tfunction);
    TypeFunction* f = (TypeFunction*)type;

    TargetABI* abi = (f->linkage == LINKintrinsic ? TargetABI::getIntrinsic() : gABI);
    // Tell the ABI we're resolving a new function type
    abi->newFunctionType(f);

    // Do not modify f->fty yet; this function may be called recursively if any
    // of the argument types refer to this type.
    IrFuncTy fty;

    // llvm idx counter
    size_t lidx = 0;

    // main needs a little special handling
    if (ismain)
    {
        fty.ret = new IrFuncTyArg(Type::tint32, false);
    }
    // sane return value
    else
    {
        Type* rt = f->next;
        unsigned a = 0;
        // sret return
        if (abi->returnInArg(f))
        {
            fty.arg_sret = new IrFuncTyArg(rt, true, StructRet | NoAlias | NoCapture);
            rt = Type::tvoid;
            lidx++;
        }
        // sext/zext return
        else if (unsigned se = DtoShouldExtend(rt))
        {
            a = se;
        }
        fty.ret = new IrFuncTyArg(rt, false, a);
    }
    lidx++;

    // member functions
    if (thistype)
    {
        bool toref = (thistype->toBasetype()->ty == Tstruct);
        fty.arg_this = new IrFuncTyArg(thistype, toref);
        lidx++;
    }

    // and nested functions
    else if (nesttype)
    {
        fty.arg_nest = new IrFuncTyArg(nesttype, false);
        lidx++;
    }

    // vararg functions are special too
    if (f->varargs)
    {
        if (f->linkage == LINKd)
        {
            // d style with hidden args
            // 2 (array) is handled by the frontend
            if (f->varargs == 1)
            {
                // _arguments
                fty.arg_arguments = new IrFuncTyArg(Type::typeinfo->type->arrayOf(), false);
                lidx++;
                // _argptr
                fty.arg_argptr = new IrFuncTyArg(Type::tvoid->pointerTo(), false, NoAlias | NoCapture);
                lidx++;
            }
        }
        else if (f->linkage == LINKc)
        {
            fty.c_vararg = true;
        }
        else
        {
            type->error(0, "invalid linkage for variadic function");
            fatal();
        }
    }

    // if this _Dmain() doesn't have an argument, we force it to have one
    int nargs = Parameter::dim(f->parameters);

    if (ismain && nargs == 0)
    {
        Type* mainargs = Type::tchar->arrayOf()->arrayOf();
        fty.args.push_back(new IrFuncTyArg(mainargs, false));
        lidx++;
    }
    // add explicit parameters
    else for (int i = 0; i < nargs; i++)
    {
        // get argument
        Parameter* arg = Parameter::getNth(f->parameters, i);

        // reference semantics? ref, out and static arrays are
        bool byref = (arg->storageClass & (STCref|STCout)) || (arg->type->toBasetype()->ty == Tsarray);

        Type* argtype = arg->type;
        unsigned a = 0;

        // handle lazy args
        if (arg->storageClass & STClazy)
        {
            Logger::println("lazy param");
            TypeFunction *ltf = new TypeFunction(NULL, arg->type, 0, LINKd);
            TypeDelegate *ltd = new TypeDelegate(ltf);
            argtype = ltd;
        }
        // byval
        else if (abi->passByVal(byref ? argtype->pointerTo() : argtype))
        {
            if (!byref) a |= llvm::Attribute::ByVal;
            byref = true;
        }
        // sext/zext
        else if (!byref)
        {
            a |= DtoShouldExtend(argtype);
        }

        fty.args.push_back(new IrFuncTyArg(argtype, byref, a));
        lidx++;
    }

    // Now we can modify f->fty safely.
    f->fty = fty;

    // let the abi rewrite the types as necesary
    abi->rewriteFunctionType(f);

    // Tell the ABI we're done with this function type
    abi->doneWithFunctionType();

    // build the function type
    std::vector<const LLType*> argtypes;
    argtypes.reserve(lidx);

    if (f->fty.arg_sret) argtypes.push_back(f->fty.arg_sret->ltype);
    if (f->fty.arg_this) argtypes.push_back(f->fty.arg_this->ltype);
    if (f->fty.arg_nest) argtypes.push_back(f->fty.arg_nest->ltype);
    if (f->fty.arg_arguments) argtypes.push_back(f->fty.arg_arguments->ltype);
    if (f->fty.arg_argptr) argtypes.push_back(f->fty.arg_argptr->ltype);

    size_t beg = argtypes.size();
    size_t nargs2 = f->fty.args.size();
    for (size_t i = 0; i < nargs2; i++)
    {
        argtypes.push_back(f->fty.args[i]->ltype);
    }

    // reverse params?
    if (f->fty.reverseParams && nargs2 > 1)
    {
        std::reverse(argtypes.begin() + beg, argtypes.end());
    }

    llvm::FunctionType* functype = llvm::FunctionType::get(f->fty.ret->ltype, argtypes, f->fty.c_vararg);

    Logger::cout() << "Final function type: " << *functype << "\n";

    return functype;
}

//////////////////////////////////////////////////////////////////////////////////////////

static const llvm::FunctionType* DtoVaFunctionType(FuncDeclaration* fdecl)
{
    TypeFunction* f = (TypeFunction*)fdecl->type;
    const llvm::FunctionType* fty = 0;

    // create new ir funcTy
    f->fty.reset();
    f->fty.ret = new IrFuncTyArg(Type::tvoid, false);

    f->fty.args.push_back(new IrFuncTyArg(Type::tvoid->pointerTo(), false));

    if (fdecl->llvmInternal == LLVMva_start)
        fty = GET_INTRINSIC_DECL(vastart)->getFunctionType();
    else if (fdecl->llvmInternal == LLVMva_copy) {
        fty = GET_INTRINSIC_DECL(vacopy)->getFunctionType();
        f->fty.args.push_back(new IrFuncTyArg(Type::tvoid->pointerTo(), false));
    }
    else if (fdecl->llvmInternal == LLVMva_end)
        fty = GET_INTRINSIC_DECL(vaend)->getFunctionType();
    assert(fty);

    return fty;
}

//////////////////////////////////////////////////////////////////////////////////////////

const llvm::FunctionType* DtoFunctionType(FuncDeclaration* fdecl)
{
    // handle for C vararg intrinsics
    if (fdecl->isVaIntrinsic())
        return DtoVaFunctionType(fdecl);

    Type *dthis=0, *dnest=0;

    if (fdecl->needThis()) {
        if (AggregateDeclaration* ad = fdecl->isMember2()) {
            Logger::println("isMember = this is: %s", ad->type->toChars());
            dthis = ad->type;
            const LLType* thisty = DtoType(dthis);
            //Logger::cout() << "this llvm type: " << *thisty << '\n';
            if (ad->isStructDeclaration())
                thisty = getPtrToType(thisty);
        }
        else {
            Logger::println("chars: %s type: %s kind: %s", fdecl->toChars(), fdecl->type->toChars(), fdecl->kind());
            assert(0);
        }
    }
    else if (fdecl->isNested()) {
        dnest = Type::tvoid->pointerTo();
    }

    const llvm::FunctionType* functype = DtoFunctionType(fdecl->type, dthis, dnest, fdecl->isMain());

    return functype;
}

//////////////////////////////////////////////////////////////////////////////////////////

static llvm::Function* DtoDeclareVaFunction(FuncDeclaration* fdecl)
{
    TypeFunction* f = (TypeFunction*)fdecl->type->toBasetype();
    const llvm::FunctionType* fty = DtoVaFunctionType(fdecl);
    llvm::Function* func = 0;

    if (fdecl->llvmInternal == LLVMva_start)
        func = GET_INTRINSIC_DECL(vastart);
    else if (fdecl->llvmInternal == LLVMva_copy)
        func = GET_INTRINSIC_DECL(vacopy);
    else if (fdecl->llvmInternal == LLVMva_end)
        func = GET_INTRINSIC_DECL(vaend);
    assert(func);

    fdecl->ir.irFunc->func = func;
    return func;
}

//////////////////////////////////////////////////////////////////////////////////////////

void DtoResolveFunction(FuncDeclaration* fdecl)
{
    if (!global.params.useUnitTests && fdecl->isUnitTestDeclaration()) {
        Logger::println("Ignoring unittest %s", fdecl->toPrettyChars());
        return; // ignore declaration completely
    }

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

    //printf("resolve function: %s\n", fdecl->toPrettyChars());

    if (fdecl->parent)
    if (TemplateInstance* tinst = fdecl->parent->isTemplateInstance())
    {
        TemplateDeclaration* tempdecl = tinst->tempdecl;
        if (tempdecl->llvmInternal == LLVMva_arg)
        {
            Logger::println("magic va_arg found");
            fdecl->llvmInternal = LLVMva_arg;
            fdecl->ir.resolved = true;
            fdecl->ir.declared = true;
            fdecl->ir.initialized = true;
            fdecl->ir.defined = true;
            return; // this gets mapped to an instruction so a declaration makes no sence
        }
        else if (tempdecl->llvmInternal == LLVMva_start)
        {
            Logger::println("magic va_start found");
            fdecl->llvmInternal = LLVMva_start;
        }
        else if (tempdecl->llvmInternal == LLVMintrinsic)
        {
            Logger::println("overloaded intrinsic found");
            fdecl->llvmInternal = LLVMintrinsic;
            DtoOverloadedIntrinsicName(tinst, tempdecl, fdecl->intrinsicName);
            fdecl->linkage = LINKintrinsic;
            ((TypeFunction*)fdecl->type)->linkage = LINKintrinsic;
        }
        else if (tempdecl->llvmInternal == LLVMinline_asm)
        {
            Logger::println("magic inline asm found");
            TypeFunction* tf = (TypeFunction*)fdecl->type;
            if (tf->varargs != 1 || (fdecl->parameters && fdecl->parameters->dim != 0))
            {
                error("invalid __asm declaration, must be a D style variadic with no explicit parameters");
                fatal();
            }
            fdecl->llvmInternal = LLVMinline_asm;
            fdecl->ir.resolved = true;
            fdecl->ir.declared = true;
            fdecl->ir.initialized = true;
            fdecl->ir.defined = true;
            return; // this gets mapped to a special inline asm call, no point in going on.
        }
    }

    DtoType(fdecl->type);

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

    // queue declaration unless the function is abstract without body
    if (!fdecl->isAbstract() || fdecl->fbody)
    {
        DtoDeclareFunction(fdecl);
    }
}

//////////////////////////////////////////////////////////////////////////////////////////

static void set_param_attrs(TypeFunction* f, llvm::Function* func, FuncDeclaration* fdecl)
{
    int funcNumArgs = func->getArgumentList().size();

    LLSmallVector<llvm::AttributeWithIndex, 9> attrs;
    llvm::AttributeWithIndex PAWI;

    int idx = 0;

    // handle implicit args
    #define ADD_PA(X) \
    if (f->fty.X) { \
        if (f->fty.X->attrs) { \
            PAWI.Index = idx; \
            PAWI.Attrs = f->fty.X->attrs; \
            attrs.push_back(PAWI); \
        } \
        idx++; \
    }

    ADD_PA(ret)
    ADD_PA(arg_sret)
    ADD_PA(arg_this)
    ADD_PA(arg_nest)
    ADD_PA(arg_arguments)
    ADD_PA(arg_argptr)

    #undef ADD_PA

    // set attrs on the rest of the arguments
    size_t n = Parameter::dim(f->parameters);
    LLSmallVector<unsigned,8> attrptr(n, 0);

    for (size_t k = 0; k < n; ++k)
    {
        Parameter* fnarg = Parameter::getNth(f->parameters, k);
        assert(fnarg);

        attrptr[k] = f->fty.args[k]->attrs;
    }

    // reverse params?
    if (f->fty.reverseParams)
    {
        std::reverse(attrptr.begin(), attrptr.end());
    }

    // build rest of attrs list
    for (int i = 0; i < n; i++)
    {
        if (attrptr[i])
        {
            PAWI.Index = idx+i;
            PAWI.Attrs = attrptr[i];
            attrs.push_back(PAWI);
        }
    }

    llvm::AttrListPtr attrlist = llvm::AttrListPtr::get(attrs.begin(), attrs.end());
    func->setAttributes(attrlist);
}

//////////////////////////////////////////////////////////////////////////////////////////

void DtoDeclareFunction(FuncDeclaration* fdecl)
{
    DtoResolveFunction(fdecl);

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

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

    //printf("declare function: %s\n", fdecl->toPrettyChars());

    // intrinsic sanity check
    if (fdecl->llvmInternal == LLVMintrinsic && fdecl->fbody) {
        error(fdecl->loc, "intrinsics cannot have function bodies");
        fatal();
    }

    // get TypeFunction*
    Type* t = fdecl->type->toBasetype();
    TypeFunction* f = (TypeFunction*)t;

    bool declareOnly = !mustDefineSymbol(fdecl);

    if (fdecl->llvmInternal == LLVMva_start)
        declareOnly = true;

    if (!fdecl->ir.irFunc) {
        fdecl->ir.irFunc = new IrFunction(fdecl);
    }

    // mangled name
    const char* mangled_name;
    if (fdecl->llvmInternal == LLVMintrinsic)
        mangled_name = fdecl->intrinsicName.c_str();
    else
        mangled_name = fdecl->mangle();

    llvm::Function* vafunc = 0;
    if (fdecl->isVaIntrinsic())
        vafunc = DtoDeclareVaFunction(fdecl);

    // construct function
    const llvm::FunctionType* functype = DtoFunctionType(fdecl);
    llvm::Function* func = vafunc ? vafunc : gIR->module->getFunction(mangled_name);
    if (!func)
        func = llvm::Function::Create(functype, DtoLinkage(fdecl), mangled_name, gIR->module);

    if (Logger::enabled())
        Logger::cout() << "func = " << *func << std::endl;

    // add func to IRFunc
    fdecl->ir.irFunc->func = func;

    // calling convention
    if (!vafunc && fdecl->llvmInternal != LLVMintrinsic)
        func->setCallingConv(DtoCallingConv(fdecl->loc, f->linkage));
    else // fall back to C, it should be the right thing to do
        func->setCallingConv(llvm::CallingConv::C);

    fdecl->ir.irFunc->func = func;

    // parameter attributes
    if (!fdecl->isIntrinsic()) {
        set_param_attrs(f, func, fdecl);
    }

    // main
    if (fdecl->isMain()) {
        gIR->mainFunc = func;
    }

    // static ctor
    if (fdecl->isStaticCtorDeclaration()) {
        if (mustDefineSymbol(fdecl)) {
            gIR->ctors.push_back(fdecl);
        }
    }
    // static dtor
    else if (fdecl->isStaticDtorDeclaration()) {
        if (mustDefineSymbol(fdecl)) {
            gIR->dtors.push_back(fdecl);
        }
    }

    // we never reference parameters of function prototypes
    std::string str;
    if (!declareOnly)
    {
        // name parameters
        llvm::Function::arg_iterator iarg = func->arg_begin();

        if (f->fty.arg_sret) {
            iarg->setName(".sret_arg");
            fdecl->ir.irFunc->retArg = iarg;
            ++iarg;
        }

        if (f->fty.arg_this) {
            iarg->setName(".this_arg");
            fdecl->ir.irFunc->thisArg = iarg;
            assert(fdecl->ir.irFunc->thisArg);
            ++iarg;
        }
        else if (f->fty.arg_nest) {
            iarg->setName(".nest_arg");
            fdecl->ir.irFunc->nestArg = iarg;
            assert(fdecl->ir.irFunc->nestArg);
            ++iarg;
        }

        if (f->fty.arg_argptr) {
            iarg->setName("._arguments");
            fdecl->ir.irFunc->_arguments = iarg;
            ++iarg;
            iarg->setName("._argptr");
            fdecl->ir.irFunc->_argptr = iarg;
            ++iarg;
        }

        int k = 0;

        for (; iarg != func->arg_end(); ++iarg)
        {
            if (fdecl->parameters && fdecl->parameters->dim > k)
            {
                Dsymbol* argsym;
                if (f->fty.reverseParams)
                    argsym = (Dsymbol*)fdecl->parameters->data[fdecl->parameters->dim-k-1];
                else
                    argsym = (Dsymbol*)fdecl->parameters->data[k];

                VarDeclaration* argvd = argsym->isVarDeclaration();
                assert(argvd);
                assert(!argvd->ir.irLocal);
                argvd->ir.irLocal = new IrLocal(argvd);
                argvd->ir.irLocal->value = iarg;

                str = argvd->ident->toChars();
                str.append("_arg");
                iarg->setName(str);

                k++;
            }
            else
            {
                iarg->setName("unnamed");
            }
        }
    }

    if (fdecl->isUnitTestDeclaration() && !declareOnly)
        gIR->unitTests.push_back(fdecl);

    if (!declareOnly)
        Type::sir->addFunctionBody(fdecl->ir.irFunc);
    else
        assert(func->getLinkage() != llvm::GlobalValue::InternalLinkage);
}

//////////////////////////////////////////////////////////////////////////////////////////

// FIXME: this isn't too pretty!

void DtoDefineFunction(FuncDeclaration* fd)
{
    DtoDeclareFunction(fd);

    if (fd->ir.defined) return;
    fd->ir.defined = true;

    assert(fd->ir.declared);

    if (Logger::enabled())
        Logger::println("DtoDefineFunc(%s): %s", fd->toPrettyChars(), fd->loc.toChars());
    LOG_SCOPE;

    // if this function is naked, we take over right away! no standard processing!
    if (fd->naked)
    {
        DtoDefineNakedFunction(fd);
        return;
    }

    #ifndef DISABLE_DEBUG_INFO
    // debug info
    if (global.params.symdebug)
        fd->ir.irFunc->diSubprogram = DtoDwarfSubProgram(fd);
    #endif

    Type* t = fd->type->toBasetype();
    TypeFunction* f = (TypeFunction*)t;
    assert(f->irtype);

    llvm::Function* func = fd->ir.irFunc->func;
    const llvm::FunctionType* functype = func->getFunctionType();

    // sanity check
    assert(mustDefineSymbol(fd));

    // set module owner
    fd->ir.DModule = gIR->dmodule;

    // is there a body?
    if (fd->fbody == NULL)
        return;

    Logger::println("Doing function body for: %s", fd->toChars());
    assert(fd->ir.irFunc);
    IrFunction* irfunction = fd->ir.irFunc;
    gIR->functions.push_back(irfunction);

    if (fd->isMain())
        gIR->emitMain = true;

    std::string entryname("entry");

    llvm::BasicBlock* beginbb = llvm::BasicBlock::Create(gIR->context(), entryname,func);
    llvm::BasicBlock* endbb = llvm::BasicBlock::Create(gIR->context(), "endentry",func);

    //assert(gIR->scopes.empty());
    gIR->scopes.push_back(IRScope(beginbb, endbb));

    // create alloca point
    // this gets erased when the function is complete, so alignment etc does not matter at all
    llvm::Instruction* allocaPoint = new llvm::AllocaInst(LLType::getInt32Ty(gIR->context()), "alloca point", beginbb);
    irfunction->allocapoint = allocaPoint;

    #ifndef DISABLE_DEBUG_INFO
    // debug info - after all allocas, but before any llvm.dbg.declare etc
    if (global.params.symdebug) DtoDwarfFuncStart(fd);
    #endif

    // this hack makes sure the frame pointer elimination optimization is disabled.
    // this this eliminates a bunch of inline asm related issues.
    if (fd->inlineAsm)
    {
        // emit a call to llvm_eh_unwind_init
        LLFunction* hack = GET_INTRINSIC_DECL(eh_unwind_init);
        gIR->ir->CreateCall(hack, "");
    }

    // give the 'this' argument storage and debug info
    if (f->fty.arg_this)
    {
        LLValue* thisvar = irfunction->thisArg;
        assert(thisvar);

        LLValue* thismem = DtoRawAlloca(thisvar->getType(), 0, "this"); // FIXME: align?
        DtoStore(thisvar, thismem);
        irfunction->thisArg = thismem;

        assert(!fd->vthis->ir.irLocal);
        fd->vthis->ir.irLocal = new IrLocal(fd->vthis);
        fd->vthis->ir.irLocal->value = thismem;

        #ifndef DISABLE_DEBUG_INFO
        if (global.params.symdebug)
            DtoDwarfLocalVariable(thismem, fd->vthis);
        #endif

    #if DMDV1
        if (fd->vthis->nestedref)
        {
            fd->nestedVars.insert(fd->vthis);
        }
    #endif
    }

    // give arguments storage
    // and debug info
    if (fd->parameters)
    {
        size_t n = f->fty.args.size();
        assert(n == fd->parameters->dim);
        for (int i=0; i < n; ++i)
        {
            Dsymbol* argsym = (Dsymbol*)fd->parameters->data[i];
            VarDeclaration* vd = argsym->isVarDeclaration();
            assert(vd);

            IrLocal* irloc = vd->ir.irLocal;
            assert(irloc);

        #if DMDV1
            if (vd->nestedref)
            {
                fd->nestedVars.insert(vd);
            }
        #endif

            bool refout = vd->storage_class & (STCref | STCout);
            bool lazy = vd->storage_class & STClazy;

            if (!refout && (!f->fty.args[i]->byref || lazy))
            {
                // alloca a stack slot for this first class value arg
                const LLType* argt;
                if (lazy)
                    argt = irloc->value->getType();
                else
                    argt = DtoType(vd->type);
                LLValue* mem = DtoRawAlloca(argt, 0, vd->ident->toChars());

                // let the abi transform the argument back first
                DImValue arg_dval(vd->type, irloc->value);
                f->fty.getParam(vd->type, i, &arg_dval, mem);

                // set the arg var value to the alloca
                irloc->value = mem;
            }

            #ifndef DISABLE_DEBUG_INFO
            if (global.params.symdebug && !(isaArgument(irloc->value) && !isaArgument(irloc->value)->hasByValAttr()) && !refout)
                DtoDwarfLocalVariable(irloc->value, vd);
            #endif
        }
    }

// need result variable? (nested)
#if DMDV1
    if (fd->vresult && fd->vresult->nestedref) {
        Logger::println("nested vresult value: %s", fd->vresult->toChars());
        fd->nestedVars.insert(fd->vresult);
    }
#endif

#if DMDV2
    // fill nestedVars
    size_t nnest = fd->closureVars.dim;
    for (size_t i = 0; i < nnest; ++i)
    {
        VarDeclaration* vd = (VarDeclaration*)fd->closureVars.data[i];
        fd->nestedVars.insert(vd);
    }
#endif

    DtoCreateNestedContext(fd);

#if DMDV2
    if (fd->vresult && fd->vresult->nestedrefs.dim) // FIXME: not sure here :/
#else
    if (fd->vresult && fd->vresult->nestedref)
#endif
    {
        DtoNestedInit(fd->vresult);
    } else if (fd->vresult) {
        fd->vresult->ir.irLocal = new IrLocal(fd->vresult);
        fd->vresult->ir.irLocal->value = DtoAlloca(fd->vresult->type, fd->vresult->toChars());
    }

    // copy _argptr and _arguments to a memory location
    if (f->linkage == LINKd && f->varargs == 1)
    {
        // _argptr
        LLValue* argptrmem = DtoRawAlloca(fd->ir.irFunc->_argptr->getType(), 0, "_argptr_mem");
        new llvm::StoreInst(fd->ir.irFunc->_argptr, argptrmem, gIR->scopebb());
        fd->ir.irFunc->_argptr = argptrmem;

        // _arguments
        LLValue* argumentsmem = DtoRawAlloca(fd->ir.irFunc->_arguments->getType(), 0, "_arguments_mem");
        new llvm::StoreInst(fd->ir.irFunc->_arguments, argumentsmem, gIR->scopebb());
        fd->ir.irFunc->_arguments = argumentsmem;
    }

    // output function body
    {
        FuncGen fg;
        irfunction->gen = &fg;
        fd->fbody->toIR(gIR);
        irfunction->gen = 0;
    }

    // TODO: clean up this mess

//     std::cout << *func << std::endl;

    llvm::BasicBlock* bb = gIR->scopebb();
    if (pred_begin(bb) == pred_end(bb) && bb != &bb->getParent()->getEntryBlock()) {
        // This block is trivially unreachable, so just delete it.
        // (This is a common case because it happens when 'return'
        // is the last statement in a function)
        bb->eraseFromParent();
    } else if (!gIR->scopereturned()) {
        // llvm requires all basic blocks to end with a TerminatorInst but DMD does not put a return statement
        // in automatically, so we do it here.

        // pass the previous block into this block
        #ifndef DISABLE_DEBUG_INFO
        if (global.params.symdebug) DtoDwarfFuncEnd(fd);
        #endif
        if (func->getReturnType() == LLType::getVoidTy(gIR->context())) {
            llvm::ReturnInst::Create(gIR->context(), gIR->scopebb());
        }
        else if (!fd->isMain()) {
            AsmBlockStatement* asmb = fd->fbody->endsWithAsm();
            if (asmb) {
                assert(asmb->abiret);
                llvm::ReturnInst::Create(gIR->context(), asmb->abiret, bb);
            }
            else {
                llvm::ReturnInst::Create(gIR->context(), llvm::UndefValue::get(func->getReturnType()), bb);
            }
        }
        else
            llvm::ReturnInst::Create(gIR->context(), LLConstant::getNullValue(func->getReturnType()), bb);
    }

//     std::cout << *func << std::endl;

    // erase alloca point
    allocaPoint->eraseFromParent();
    allocaPoint = 0;
    gIR->func()->allocapoint = 0;

    gIR->scopes.pop_back();

    // get rid of the endentry block, it's never used
    assert(!func->getBasicBlockList().empty());
    func->getBasicBlockList().pop_back();

    gIR->functions.pop_back();

//     std::cout << *func << std::endl;
}

//////////////////////////////////////////////////////////////////////////////////////////

const llvm::FunctionType* DtoBaseFunctionType(FuncDeclaration* fdecl)
{
    Dsymbol* parent = fdecl->toParent();
    ClassDeclaration* cd = parent->isClassDeclaration();
    assert(cd);

    FuncDeclaration* f = fdecl;

    while (cd)
    {
        ClassDeclaration* base = cd->baseClass;
        if (!base)
            break;
        FuncDeclaration* f2 = base->findFunc(fdecl->ident, (TypeFunction*)fdecl->type);
        if (f2) {
            f = f2;
            cd = base;
        }
        else
            break;
    }

    DtoResolveDsymbol(f);
    return llvm::cast<llvm::FunctionType>(DtoType(f->type));
}

//////////////////////////////////////////////////////////////////////////////////////////

DValue* DtoArgument(Parameter* fnarg, Expression* argexp)
{
    Logger::println("DtoArgument");
    LOG_SCOPE;

    DValue* arg = argexp->toElem(gIR);

    // ref/out arg
    if (fnarg && (fnarg->storageClass & (STCref | STCout)))
    {
        if (arg->isVar())
            arg = new DImValue(argexp->type, arg->getLVal());
        else
            arg = new DImValue(argexp->type, arg->getRVal());
    }
    // lazy arg
    else if (fnarg && (fnarg->storageClass & STClazy))
    {
        assert(argexp->type->toBasetype()->ty == Tdelegate);
        assert(!arg->isLVal());
        return arg;
    }
    // byval arg, but expr has no storage yet
    else if (DtoIsPassedByRef(argexp->type) && (arg->isSlice() || arg->isNull()))
    {
        LLValue* alloc = DtoAlloca(argexp->type, ".tmp_arg");
        DVarValue* vv = new DVarValue(argexp->type, alloc);
        DtoAssign(argexp->loc, vv, arg);
        arg = vv;
    }

    return arg;
}

//////////////////////////////////////////////////////////////////////////////////////////

void DtoVariadicArgument(Expression* argexp, LLValue* dst)
{
    Logger::println("DtoVariadicArgument");
    LOG_SCOPE;
    DVarValue vv(argexp->type, dst);
    DtoAssign(argexp->loc, &vv, argexp->toElem(gIR));
}

//////////////////////////////////////////////////////////////////////////////////////////

bool FuncDeclaration::isIntrinsic()
{
    return (llvmInternal == LLVMintrinsic || isVaIntrinsic());
}

bool FuncDeclaration::isVaIntrinsic()
{
    return (llvmInternal == LLVMva_start ||
            llvmInternal == LLVMva_copy ||
            llvmInternal == LLVMva_end);
}