view gen/llvmhelpers.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 8f121883bce8
children
line wrap: on
line source
#include "gen/llvmhelpers.h"
#include "gen/llvm.h"

#include "mars.h"
#include "init.h"
#include "id.h"
#include "expression.h"
#include "template.h"
#include "module.h"

#include "gen/tollvm.h"
#include "gen/irstate.h"
#include "gen/runtime.h"
#include "gen/logger.h"
#include "gen/arrays.h"
#include "gen/dvalue.h"
#include "gen/complex.h"
#include "gen/classes.h"
#include "gen/functions.h"
#include "gen/typeinf.h"
#include "gen/todebug.h"
#include "gen/cl_options.h"
#include "gen/nested.h"
#include "ir/irmodule.h"

#include <stack>

/****************************************************************************************/
/*////////////////////////////////////////////////////////////////////////////////////////
// DYNAMIC MEMORY HELPERS
////////////////////////////////////////////////////////////////////////////////////////*/

LLValue* DtoNew(Type* newtype)
{
    // get runtime function
    llvm::Function* fn = LLVM_D_GetRuntimeFunction(gIR->module, "_d_allocmemoryT");
    // get type info
    LLConstant* ti = DtoTypeInfoOf(newtype);
    assert(isaPointer(ti));
    // call runtime allocator
    LLValue* mem = gIR->CreateCallOrInvoke(fn, ti, ".gc_mem").getInstruction();
    // cast
    return DtoBitCast(mem, getPtrToType(DtoType(newtype)), ".gc_mem");
}

void DtoDeleteMemory(LLValue* ptr)
{
    // get runtime function
    llvm::Function* fn = LLVM_D_GetRuntimeFunction(gIR->module, "_d_delmemory");
    // build args
    LLSmallVector<LLValue*,1> arg;
    arg.push_back(DtoBitCast(ptr, getVoidPtrType(), ".tmp"));
    // call
    gIR->CreateCallOrInvoke(fn, arg.begin(), arg.end());
}

void DtoDeleteClass(LLValue* inst)
{
    // get runtime function
    llvm::Function* fn = LLVM_D_GetRuntimeFunction(gIR->module, "_d_delclass");
    // build args
    LLSmallVector<LLValue*,1> arg;
    arg.push_back(DtoBitCast(inst, fn->getFunctionType()->getParamType(0), ".tmp"));
    // call
    gIR->CreateCallOrInvoke(fn, arg.begin(), arg.end());
}

void DtoDeleteInterface(LLValue* inst)
{
    // get runtime function
    llvm::Function* fn = LLVM_D_GetRuntimeFunction(gIR->module, "_d_delinterface");
    // build args
    LLSmallVector<LLValue*,1> arg;
    arg.push_back(DtoBitCast(inst, fn->getFunctionType()->getParamType(0), ".tmp"));
    // call
    gIR->CreateCallOrInvoke(fn, arg.begin(), arg.end());
}

void DtoDeleteArray(DValue* arr)
{
    // get runtime function
    llvm::Function* fn = LLVM_D_GetRuntimeFunction(gIR->module, "_d_delarray");
    // build args
    LLSmallVector<LLValue*,2> arg;
    arg.push_back(DtoArrayLen(arr));
    arg.push_back(DtoBitCast(DtoArrayPtr(arr), getVoidPtrType(), ".tmp"));
    // call
    gIR->CreateCallOrInvoke(fn, arg.begin(), arg.end());
}

/****************************************************************************************/
/*////////////////////////////////////////////////////////////////////////////////////////
// ALLOCA HELPERS
////////////////////////////////////////////////////////////////////////////////////////*/


llvm::AllocaInst* DtoAlloca(Type* type, const char* name)
{
    const llvm::Type* lltype = DtoType(type);
    llvm::AllocaInst* ai = new llvm::AllocaInst(lltype, name, gIR->topallocapoint());
    ai->setAlignment(type->alignsize());
    return ai;
}

llvm::AllocaInst* DtoArrayAlloca(Type* type, unsigned arraysize, const char* name)
{
    const llvm::Type* lltype = DtoType(type);
    llvm::AllocaInst* ai = new llvm::AllocaInst(
        lltype, DtoConstUint(arraysize), name, gIR->topallocapoint());
    ai->setAlignment(type->alignsize());
    return ai;
}

llvm::AllocaInst* DtoRawAlloca(const llvm::Type* lltype, size_t alignment, const char* name)
{
    llvm::AllocaInst* ai = new llvm::AllocaInst(lltype, name, gIR->topallocapoint());
    if (alignment)
        ai->setAlignment(alignment);
    return ai;
}


/****************************************************************************************/
/*////////////////////////////////////////////////////////////////////////////////////////
// ASSERT HELPER
////////////////////////////////////////////////////////////////////////////////////////*/

void DtoAssert(Module* M, Loc loc, DValue* msg)
{
    std::vector<LLValue*> args;

    // func
    const char* fname = msg ? "_d_assert_msg" : "_d_assert";
    llvm::Function* fn = LLVM_D_GetRuntimeFunction(gIR->module, fname);

    // msg param
    if (msg)
    {
        args.push_back(msg->getRVal());
    }

    // file param

    // we might be generating for an imported template function
    const char* cur_file = M->srcfile->name->toChars();
    if (loc.filename && strcmp(loc.filename, cur_file) != 0)
    {
        args.push_back(DtoConstString(loc.filename));
    }
    else
    {
        IrModule* irmod = getIrModule(M);
        args.push_back(DtoLoad(irmod->fileName));
    }

    // line param
    LLConstant* c = DtoConstUint(loc.linnum);
    args.push_back(c);

    // call
    gIR->CreateCallOrInvoke(fn, args.begin(), args.end());

    #ifndef DISABLE_DEBUG_INFO
    // end debug info
    if (global.params.symdebug)
        DtoDwarfFuncEnd(gIR->func()->decl);
    #endif

    // after assert is always unreachable
    gIR->ir->CreateUnreachable();
}


/****************************************************************************************/
/*////////////////////////////////////////////////////////////////////////////////////////
// LABEL HELPER
////////////////////////////////////////////////////////////////////////////////////////*/
LabelStatement* DtoLabelStatement(Identifier* ident)
{
    FuncDeclaration* fd = gIR->func()->decl;
    FuncDeclaration::LabelMap::iterator iter = fd->labmap.find(ident->toChars());
    if (iter == fd->labmap.end())
    {
        if (fd->returnLabel && fd->returnLabel->ident->equals(ident))
        {
            assert(fd->returnLabel->statement);
            return fd->returnLabel->statement;
        }
        return NULL;
    }
    return iter->second;
}

/****************************************************************************************/
/*////////////////////////////////////////////////////////////////////////////////////////
// GOTO HELPER
////////////////////////////////////////////////////////////////////////////////////////*/
void DtoGoto(Loc loc, Identifier* target, TryFinallyStatement* sourceFinally)
{
    assert(!gIR->scopereturned());

    LabelStatement* lblstmt = DtoLabelStatement(target);
    if(!lblstmt) {
        error(loc, "the label %s does not exist", target->toChars());
        fatal();
    }

    // if the target label is inside inline asm, error
    if(lblstmt->asmLabel) {
        error(loc, "cannot goto to label %s inside an inline asm block", target->toChars());
        fatal();
    }

    // find target basic block
    std::string labelname = gIR->func()->gen->getScopedLabelName(target->toChars());
    llvm::BasicBlock*& targetBB = gIR->func()->gen->labelToBB[labelname];
    if (targetBB == NULL)
        targetBB = llvm::BasicBlock::Create(gIR->context(), "label_" + labelname, gIR->topfunc());

    // emit code for finallys between goto and label
    DtoEnclosingHandlers(loc, lblstmt);

    // goto into finally blocks is forbidden by the spec
    // but should work fine
    if(lblstmt->enclosingFinally != sourceFinally) {
        error(loc, "spec disallows goto into or out of finally block");
        fatal();
    }

    llvm::BranchInst::Create(targetBB, gIR->scopebb());
}

/****************************************************************************************/
/*////////////////////////////////////////////////////////////////////////////////////////
// TRY-FINALLY, VOLATILE AND SYNCHRONIZED HELPER
////////////////////////////////////////////////////////////////////////////////////////*/

void EnclosingSynchro::emitCode(IRState * p)
{
    if (s->exp)
        DtoLeaveMonitor(s->exp->toElem(p)->getRVal());
    else
        DtoLeaveCritical(s->llsync);
}

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

void EnclosingVolatile::emitCode(IRState * p)
{
    // store-load barrier
    DtoMemoryBarrier(false, false, true, false);
}

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

void EnclosingTryFinally::emitCode(IRState * p)
{
    if (tf->finalbody)
    {
        llvm::BasicBlock* oldpad = p->func()->gen->landingPad;
        p->func()->gen->landingPad = landingPad;
        tf->finalbody->toIR(p);
        p->func()->gen->landingPad = oldpad;
    }
}

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

void DtoEnclosingHandlers(Loc loc, Statement* target)
{
    // labels are a special case: they are not required to enclose the current scope
    // for them we use the enclosing scope handler as a reference point
    LabelStatement* lblstmt = target ? target->isLabelStatement() : 0;
    if (lblstmt)
        target = lblstmt->enclosingScopeExit;

    // figure out up until what handler we need to emit
    FuncGen::TargetScopeVec::reverse_iterator targetit = gIR->func()->gen->targetScopes.rbegin();
    FuncGen::TargetScopeVec::reverse_iterator it_end = gIR->func()->gen->targetScopes.rend();
    while(targetit != it_end) {
        if (targetit->s == target) {
            break;
        }
        ++targetit;
    }

    if (target && targetit == it_end) {
        if (lblstmt)
            error(loc, "cannot goto into try, volatile or synchronized statement at %s", target->loc.toChars());
        else
            error(loc, "internal error, cannot find jump path to statement at %s", target->loc.toChars());
        return;
    }

    //
    // emit code for enclosing handlers
    //

    // since the labelstatements possibly inside are private
    // and might already exist push a label scope
    gIR->func()->gen->pushUniqueLabelScope("enclosing");
    FuncGen::TargetScopeVec::reverse_iterator it = gIR->func()->gen->targetScopes.rbegin();
    while (it != targetit) {
        if (it->enclosinghandler)
            it->enclosinghandler->emitCode(gIR);
        ++it;
    }
    gIR->func()->gen->popLabelScope();
}

/****************************************************************************************/
/*////////////////////////////////////////////////////////////////////////////////////////
// SYNCHRONIZED SECTION HELPERS
////////////////////////////////////////////////////////////////////////////////////////*/

void DtoEnterCritical(LLValue* g)
{
    LLFunction* fn = LLVM_D_GetRuntimeFunction(gIR->module, "_d_criticalenter");
    gIR->CreateCallOrInvoke(fn, g);
}

void DtoLeaveCritical(LLValue* g)
{
    LLFunction* fn = LLVM_D_GetRuntimeFunction(gIR->module, "_d_criticalexit");
    gIR->CreateCallOrInvoke(fn, g);
}

void DtoEnterMonitor(LLValue* v)
{
    LLFunction* fn = LLVM_D_GetRuntimeFunction(gIR->module, "_d_monitorenter");
    v = DtoBitCast(v, fn->getFunctionType()->getParamType(0));
    gIR->CreateCallOrInvoke(fn, v);
}

void DtoLeaveMonitor(LLValue* v)
{
    LLFunction* fn = LLVM_D_GetRuntimeFunction(gIR->module, "_d_monitorexit");
    v = DtoBitCast(v, fn->getFunctionType()->getParamType(0));
    gIR->CreateCallOrInvoke(fn, v);
}

/****************************************************************************************/
/*////////////////////////////////////////////////////////////////////////////////////////
// ASSIGNMENT HELPER (store this in that)
////////////////////////////////////////////////////////////////////////////////////////*/

// is this a good approach at all ?

void DtoAssign(Loc& loc, DValue* lhs, DValue* rhs)
{
    Logger::println("DtoAssign(...);\n");
    LOG_SCOPE;

    Type* t = lhs->getType()->toBasetype();
    Type* t2 = rhs->getType()->toBasetype();

    if (t->ty == Tstruct) {
        if (!t->equals(t2)) {
            // FIXME: use 'rhs' for something !?!
            DtoAggrZeroInit(lhs->getLVal());
        }
        else {
            DtoAggrCopy(lhs->getLVal(), rhs->getRVal());
        }
    }
    else if (t->ty == Tarray) {
        // lhs is slice
        if (DSliceValue* s = lhs->isSlice()) {
            if (DSliceValue* s2 = rhs->isSlice()) {
                DtoArrayCopySlices(s, s2);
            }
            else if (t->nextOf()->toBasetype()->equals(t2)) {
                DtoArrayInit(loc, s, rhs);
            }
            else {
                DtoArrayCopyToSlice(s, rhs);
            }
        }
        // rhs is slice
        else if (DSliceValue* s = rhs->isSlice()) {
            assert(s->getType()->toBasetype() == lhs->getType()->toBasetype());
            DtoSetArray(lhs->getLVal(),DtoArrayLen(s),DtoArrayPtr(s));
        }
        // null
        else if (rhs->isNull()) {
            DtoSetArrayToNull(lhs->getLVal());
        }
        // reference assignment
        else if (t2->ty == Tarray) {
            DtoStore(rhs->getRVal(), lhs->getLVal());
        }
        // some implicitly converting ref assignment
        else {
            DtoSetArray(lhs->getLVal(), DtoArrayLen(rhs), DtoArrayPtr(rhs));
        }
    }
    else if (t->ty == Tsarray) {
        // T[n] = T[n]
        if (DtoType(lhs->getType()) == DtoType(rhs->getType())) {
            DtoStaticArrayCopy(lhs->getLVal(), rhs->getRVal());
        }
        // T[n] = T
        else if (t->nextOf()->toBasetype()->equals(t2)) {
            DtoArrayInit(loc, lhs, rhs);
        }
        // T[n] = T[] - generally only generated by frontend in rare cases
        else if (t2->ty == Tarray && t->nextOf()->toBasetype()->equals(t2->nextOf()->toBasetype())) {
            DtoMemCpy(lhs->getLVal(), DtoArrayPtr(rhs), DtoArrayLen(rhs));
        } else {
            assert(0 && "Unimplemented static array assign!");
        }
    }
    else if (t->ty == Tdelegate) {
        LLValue* l = lhs->getLVal();
        LLValue* r = rhs->getRVal();
        if (Logger::enabled())
            Logger::cout() << "assign\nlhs: " << *l << "rhs: " << *r << '\n';
        DtoStore(r, l);
    }
    else if (t->ty == Tclass) {
        assert(t2->ty == Tclass);
        LLValue* l = lhs->getLVal();
        LLValue* r = rhs->getRVal();
        if (Logger::enabled())
        {
            Logger::cout() << "l : " << *l << '\n';
            Logger::cout() << "r : " << *r << '\n';
        }
        r = DtoBitCast(r, l->getType()->getContainedType(0));
        DtoStore(r, l);
    }
    else if (t->iscomplex()) {
        LLValue* dst = lhs->getLVal();
        LLValue* src = DtoCast(loc, rhs, lhs->getType())->getRVal();
        DtoStore(src, dst);
    }
    else {
        LLValue* l = lhs->getLVal();
        LLValue* r = rhs->getRVal();
        if (Logger::enabled())
            Logger::cout() << "assign\nlhs: " << *l << "rhs: " << *r << '\n';
        const LLType* lit = l->getType()->getContainedType(0);
        if (r->getType() != lit) {
            r = DtoCast(loc, rhs, lhs->getType())->getRVal();
            if (Logger::enabled())
                Logger::cout() << "really assign\nlhs: " << *l << "rhs: " << *r << '\n';
            assert(r->getType() == l->getType()->getContainedType(0));
        }
        gIR->ir->CreateStore(r, l);
    }
}

/****************************************************************************************/
/*////////////////////////////////////////////////////////////////////////////////////////
//      NULL VALUE HELPER
////////////////////////////////////////////////////////////////////////////////////////*/

DValue* DtoNullValue(Type* type)
{
    Type* basetype = type->toBasetype();
    TY basety = basetype->ty;
    const LLType* lltype = DtoType(basetype);

    // complex, needs to be first since complex are also floating
    if (basetype->iscomplex())
    {
        const LLType* basefp = DtoComplexBaseType(basetype);
        LLValue* res = DtoAggrPair(DtoType(type), LLConstant::getNullValue(basefp), LLConstant::getNullValue(basefp));
        return new DImValue(type, res);
    }
    // integer, floating, pointer and class have no special representation
    else if (basetype->isintegral() || basetype->isfloating() || basety == Tpointer || basety == Tclass)
    {
        return new DConstValue(type, LLConstant::getNullValue(lltype));
    }
    // dynamic array
    else if (basety == Tarray)
    {
        LLValue* len = DtoConstSize_t(0);
        LLValue* ptr = getNullPtr(getPtrToType(DtoType(basetype->nextOf())));
        return new DSliceValue(type, len, ptr);
    }
    // delegate
    else if (basety == Tdelegate)
    {
        return new DNullValue(type, LLConstant::getNullValue(lltype));
    }

    // unknown
    error("unsupported: null value for %s", type->toChars());
    assert(0);
    return 0;

}


/****************************************************************************************/
/*////////////////////////////////////////////////////////////////////////////////////////
//      CASTING HELPERS
////////////////////////////////////////////////////////////////////////////////////////*/

DValue* DtoCastInt(Loc& loc, DValue* val, Type* _to)
{
    const LLType* tolltype = DtoType(_to);

    Type* to = _to->toBasetype();
    Type* from = val->getType()->toBasetype();
    assert(from->isintegral());

    size_t fromsz = from->size();
    size_t tosz = to->size();

    LLValue* rval = val->getRVal();
    if (rval->getType() == tolltype) {
        return new DImValue(_to, rval);
    }

    if (to->ty == Tbool) {
        LLValue* zero = LLConstantInt::get(rval->getType(), 0, false);
        rval = gIR->ir->CreateICmpNE(rval, zero, "tmp");
    }
    else if (to->isintegral()) {
        if (fromsz < tosz || from->ty == Tbool) {
            if (Logger::enabled())
                Logger::cout() << "cast to: " << *tolltype << '\n';
            if (from->isunsigned() || from->ty == Tbool) {
                rval = new llvm::ZExtInst(rval, tolltype, "tmp", gIR->scopebb());
            } else {
                rval = new llvm::SExtInst(rval, tolltype, "tmp", gIR->scopebb());
            }
        }
        else if (fromsz > tosz) {
            rval = new llvm::TruncInst(rval, tolltype, "tmp", gIR->scopebb());
        }
        else {
            rval = DtoBitCast(rval, tolltype);
        }
    }
    else if (to->iscomplex()) {
        return DtoComplex(loc, to, val);
    }
    else if (to->isfloating()) {
        if (from->isunsigned()) {
            rval = new llvm::UIToFPInst(rval, tolltype, "tmp", gIR->scopebb());
        }
        else {
            rval = new llvm::SIToFPInst(rval, tolltype, "tmp", gIR->scopebb());
        }
    }
    else if (to->ty == Tpointer) {
        if (Logger::enabled())
            Logger::cout() << "cast pointer: " << *tolltype << '\n';
        rval = gIR->ir->CreateIntToPtr(rval, tolltype, "tmp");
    }
    else {
        error(loc, "invalid cast from '%s' to '%s'", val->getType()->toChars(), _to->toChars());
        fatal();
    }

    return new DImValue(_to, rval);
}

DValue* DtoCastPtr(Loc& loc, DValue* val, Type* to)
{
    const LLType* tolltype = DtoType(to);

    Type* totype = to->toBasetype();
    Type* fromtype = val->getType()->toBasetype();
    assert(fromtype->ty == Tpointer || fromtype->ty == Tfunction);

    LLValue* rval;

    if (totype->ty == Tpointer || totype->ty == Tclass) {
        LLValue* src = val->getRVal();
        if (Logger::enabled())
            Logger::cout() << "src: " << *src << "to type: " << *tolltype << '\n';
        rval = DtoBitCast(src, tolltype);
    }
    else if (totype->ty == Tbool) {
        LLValue* src = val->getRVal();
        LLValue* zero = LLConstant::getNullValue(src->getType());
        rval = gIR->ir->CreateICmpNE(src, zero, "tmp");
    }
    else if (totype->isintegral()) {
        rval = new llvm::PtrToIntInst(val->getRVal(), tolltype, "tmp", gIR->scopebb());
    }
    else {
        error(loc, "invalid cast from '%s' to '%s'", val->getType()->toChars(), to->toChars());
        fatal();
    }

    return new DImValue(to, rval);
}

DValue* DtoCastFloat(Loc& loc, DValue* val, Type* to)
{
    if (val->getType() == to)
        return val;

    const LLType* tolltype = DtoType(to);

    Type* totype = to->toBasetype();
    Type* fromtype = val->getType()->toBasetype();
    assert(fromtype->isfloating());

    size_t fromsz = fromtype->size();
    size_t tosz = totype->size();

    LLValue* rval;

    if (totype->ty == Tbool) {
        rval = val->getRVal();
        LLValue* zero = LLConstant::getNullValue(rval->getType());
        rval = gIR->ir->CreateFCmpUNE(rval, zero, "tmp");
    }
    else if (totype->iscomplex()) {
        return DtoComplex(loc, to, val);
    }
    else if (totype->isfloating()) {
        if (fromsz == tosz) {
            rval = val->getRVal();
            assert(rval->getType() == tolltype);
        }
        else if (fromsz < tosz) {
            rval = new llvm::FPExtInst(val->getRVal(), tolltype, "tmp", gIR->scopebb());
        }
        else if (fromsz > tosz) {
            rval = new llvm::FPTruncInst(val->getRVal(), tolltype, "tmp", gIR->scopebb());
        }
        else {
            error(loc, "invalid cast from '%s' to '%s'", val->getType()->toChars(), to->toChars());
            fatal();
        }
    }
    else if (totype->isintegral()) {
        if (totype->isunsigned()) {
            rval = new llvm::FPToUIInst(val->getRVal(), tolltype, "tmp", gIR->scopebb());
        }
        else {
            rval = new llvm::FPToSIInst(val->getRVal(), tolltype, "tmp", gIR->scopebb());
        }
    }
    else {
        error(loc, "invalid cast from '%s' to '%s'", val->getType()->toChars(), to->toChars());
        fatal();
    }

    return new DImValue(to, rval);
}

DValue* DtoCastDelegate(Loc& loc, DValue* val, Type* to)
{
    if (to->toBasetype()->ty == Tdelegate)
    {
        return DtoPaintType(loc, val, to);
    }
    else if (to->toBasetype()->ty == Tbool)
    {
        return new DImValue(to, DtoDelegateEquals(TOKnotequal, val->getRVal(), NULL));
    }
    else
    {
        error(loc, "invalid cast from '%s' to '%s'", val->getType()->toChars(), to->toChars());
        fatal();
    }
}

DValue* DtoCast(Loc& loc, DValue* val, Type* to)
{
    Type* fromtype = val->getType()->toBasetype();
    Type* totype = to->toBasetype();
    if (fromtype->equals(totype))
        return val;

    Logger::println("Casting from '%s' to '%s'", fromtype->toChars(), to->toChars());
    LOG_SCOPE;

    if (fromtype->isintegral()) {
        return DtoCastInt(loc, val, to);
    }
    else if (fromtype->iscomplex()) {
        return DtoCastComplex(loc, val, to);
    }
    else if (fromtype->isfloating()) {
        return DtoCastFloat(loc, val, to);
    }
    else if (fromtype->ty == Tclass) {
        return DtoCastClass(val, to);
    }
    else if (fromtype->ty == Tarray || fromtype->ty == Tsarray) {
        return DtoCastArray(loc, val, to);
    }
    else if (fromtype->ty == Tpointer || fromtype->ty == Tfunction) {
        return DtoCastPtr(loc, val, to);
    }
    else if (fromtype->ty == Tdelegate) {
        return DtoCastDelegate(loc, val, to);
    }
    else {
        error(loc, "invalid cast from '%s' to '%s'", val->getType()->toChars(), to->toChars());
        fatal();
    }
}

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

DValue* DtoPaintType(Loc& loc, DValue* val, Type* to)
{
    Type* from = val->getType()->toBasetype();
    Logger::println("repainting from '%s' to '%s'", from->toChars(), to->toChars());

    if (from->ty == Tarray)
    {
        Type* at = to->toBasetype();
        assert(at->ty == Tarray);
        Type* elem = at->nextOf()->pointerTo();
        if (DSliceValue* slice = val->isSlice())
        {
            return new DSliceValue(to, slice->len, DtoBitCast(slice->ptr, DtoType(elem)));
        }
        else if (val->isLVal())
        {
            LLValue* ptr = val->getLVal();
            ptr = DtoBitCast(ptr, DtoType(at->pointerTo()));
            return new DVarValue(to, ptr);
        }
        else
        {
            LLValue *len, *ptr;
            len = DtoArrayLen(val);
            ptr = DtoArrayPtr(val);
            ptr = DtoBitCast(ptr, DtoType(elem));
            return new DImValue(to, DtoAggrPair(len, ptr, "tmp"));
        }
    }
    else if (from->ty == Tdelegate)
    {
        Type* dgty = to->toBasetype();
        assert(dgty->ty == Tdelegate);
        if (val->isLVal())
        {
            LLValue* ptr = val->getLVal();
            assert(isaPointer(ptr));
            ptr = DtoBitCast(ptr, getPtrToType(DtoType(dgty)));
            if (Logger::enabled())
                Logger::cout() << "dg ptr: " << *ptr << '\n';
            return new DVarValue(to, ptr);
        }
        else
        {
            LLValue* dg = val->getRVal();
            LLValue* context = gIR->ir->CreateExtractValue(dg, 0, ".context");
            LLValue* funcptr = gIR->ir->CreateExtractValue(dg, 1, ".funcptr");
            funcptr = DtoBitCast(funcptr, DtoType(dgty)->getContainedType(1));
            LLValue* aggr = DtoAggrPair(context, funcptr, "tmp");
            if (Logger::enabled())
                Logger::cout() << "dg: " << *aggr << '\n';
            return new DImValue(to, aggr);
        }
    }
    else if (from->ty == Tpointer || from->ty == Tclass || from->ty == Taarray)
    {
        Type* b = to->toBasetype();
        assert(b->ty == Tpointer || b->ty == Tclass || b->ty == Taarray);
        LLValue* ptr = DtoBitCast(val->getRVal(), DtoType(b));
        return new DImValue(to, ptr);
    }
    else
    {
        assert(!val->isLVal());
        assert(DtoType(to) == DtoType(to));
        return new DImValue(to, val->getRVal());
    }
}

/****************************************************************************************/
/*////////////////////////////////////////////////////////////////////////////////////////
//      TEMPLATE HELPERS
////////////////////////////////////////////////////////////////////////////////////////*/

TemplateInstance* DtoIsTemplateInstance(Dsymbol* s)
{
    if (!s) return NULL;
    if (s->isTemplateInstance() && !s->isTemplateMixin())
        return s->isTemplateInstance();
    else if (s->parent)
        return DtoIsTemplateInstance(s->parent);
    return NULL;
}

/****************************************************************************************/
/*////////////////////////////////////////////////////////////////////////////////////////
//      PROCESSING QUEUE HELPERS
////////////////////////////////////////////////////////////////////////////////////////*/

void DtoResolveDsymbol(Dsymbol* dsym)
{
    if (StructDeclaration* sd = dsym->isStructDeclaration()) {
        DtoResolveStruct(sd);
    }
    else if (ClassDeclaration* cd = dsym->isClassDeclaration()) {
        DtoResolveClass(cd);
    }
    else if (FuncDeclaration* fd = dsym->isFuncDeclaration()) {
        DtoResolveFunction(fd);
    }
    else if (TypeInfoDeclaration* fd = dsym->isTypeInfoDeclaration()) {
        DtoResolveTypeInfo(fd);
    }
    else {
    error(dsym->loc, "unsupported dsymbol: %s", dsym->toChars());
    assert(0 && "unsupported dsymbol for DtoResolveDsymbol");
    }
}

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

void DtoConstInitGlobal(VarDeclaration* vd)
{
    vd->codegen(Type::sir);

    if (vd->ir.initialized) return;
    vd->ir.initialized = gIR->dmodule;

    Logger::println("DtoConstInitGlobal(%s) @ %s", vd->toChars(), vd->loc.toChars());
    LOG_SCOPE;

    Dsymbol* par = vd->toParent();

    // build the initializer
    LLConstant* initVal = DtoConstInitializer(vd->loc, vd->type, vd->init);

    // set the initializer if appropriate
    IrGlobal* glob = vd->ir.irGlobal;
    llvm::GlobalVariable* gvar = llvm::cast<llvm::GlobalVariable>(glob->value);

    // refine the global's opaque type to the type of the initializer
    llvm::cast<LLOpaqueType>(glob->type.get())->refineAbstractTypeTo(initVal->getType());

    assert(!glob->constInit);
    glob->constInit = initVal;

    // assign the initializer
    llvm::GlobalVariable* globalvar = llvm::cast<llvm::GlobalVariable>(glob->value);

    if (!(vd->storage_class & STCextern) && mustDefineSymbol(vd))
    {
        if (Logger::enabled())
        {
            Logger::println("setting initializer");
            Logger::cout() << "global: " << *gvar << '\n';
#if 0
            Logger::cout() << "init:   " << *initVal << '\n';
#endif
        }

        gvar->setInitializer(initVal);

        #ifndef DISABLE_DEBUG_INFO
        // do debug info
        if (global.params.symdebug)
        {
            LLGlobalVariable* gv = DtoDwarfGlobalVariable(gvar, vd).getGV();
            // keep a reference so GDCE doesn't delete it !
            gIR->usedArray.push_back(llvm::ConstantExpr::getBitCast(gv, getVoidPtrType()));
        }
        #endif
    }
}

/****************************************************************************************/
/*////////////////////////////////////////////////////////////////////////////////////////
//      DECLARATION EXP HELPER
////////////////////////////////////////////////////////////////////////////////////////*/
DValue* DtoDeclarationExp(Dsymbol* declaration)
{
    Logger::print("DtoDeclarationExp: %s\n", declaration->toChars());
    LOG_SCOPE;

    // variable declaration
    if (VarDeclaration* vd = declaration->isVarDeclaration())
    {
        Logger::println("VarDeclaration");

        // if aliassym is set, this VarDecl is redone as an alias to another symbol
        // this seems to be done to rewrite Tuple!(...) v;
        // as a TupleDecl that contains a bunch of individual VarDecls
        if (vd->aliassym)
            return DtoDeclarationExp(vd->aliassym);

        // static
        if (vd->isDataseg())
        {
            vd->codegen(Type::sir);
        }
        else
        {
            if (global.params.llvmAnnotate)
                DtoAnnotation(declaration->toChars());

            Logger::println("vdtype = %s", vd->type->toChars());

            // ref vardecls are generated when DMD lowers foreach to a for statement,
            // and this is a hack to support them for this case only
            if(vd->isRef())
            {
                if (!vd->ir.irLocal)
                    vd->ir.irLocal = new IrLocal(vd);

                ExpInitializer* ex = vd->init->isExpInitializer();
                assert(ex && "ref vars must have expression initializer");
                assert(ex->exp);
                AssignExp* as = ex->exp->isAssignExp();
                assert(as && "ref vars must be initialized by an assign exp");
                vd->ir.irLocal->value = as->e2->toElem(gIR)->getLVal();
            }

            // referenced by nested delegate?
        #if DMDV2
            if (vd->nestedrefs.dim) {
        #else
            if (vd->nestedref) {
        #endif
                Logger::println("has nestedref set");
                assert(vd->ir.irLocal);

                DtoNestedInit(vd);
            }
            // normal stack variable, allocate storage on the stack if it has not already been done
            else if(!vd->ir.irLocal && !vd->isRef()) {
                vd->ir.irLocal = new IrLocal(vd);

                const LLType* lltype = DtoType(vd->type);

                llvm::Value* allocainst;
                if(gTargetData->getTypeSizeInBits(lltype) == 0)
                    allocainst = llvm::ConstantPointerNull::get(getPtrToType(lltype));
                else
                    allocainst = DtoAlloca(vd->type, vd->toChars());

                //allocainst->setAlignment(vd->type->alignsize()); // TODO
                vd->ir.irLocal->value = allocainst;

                #ifndef DISABLE_DEBUG_INFO
                if (global.params.symdebug)
                    DtoDwarfLocalVariable(allocainst, vd);
                #endif
            }
            else
            {
                assert(vd->ir.irLocal->value);
            }

            if (Logger::enabled())
                Logger::cout() << "llvm value for decl: " << *vd->ir.irLocal->value << '\n';
            if (!vd->isRef())
                DValue* ie = DtoInitializer(vd->ir.irLocal->value, vd->init);
        }

        return new DVarValue(vd->type, vd, vd->ir.getIrValue());
    }
    // struct declaration
    else if (StructDeclaration* s = declaration->isStructDeclaration())
    {
        Logger::println("StructDeclaration");
        s->codegen(Type::sir);
    }
    // function declaration
    else if (FuncDeclaration* f = declaration->isFuncDeclaration())
    {
        Logger::println("FuncDeclaration");
        f->codegen(Type::sir);
    }
    // alias declaration
    else if (AliasDeclaration* a = declaration->isAliasDeclaration())
    {
        Logger::println("AliasDeclaration - no work");
        // do nothing
    }
    // enum
    else if (EnumDeclaration* e = declaration->isEnumDeclaration())
    {
        Logger::println("EnumDeclaration - no work");
        // do nothing
    }
    // class
    else if (ClassDeclaration* e = declaration->isClassDeclaration())
    {
        Logger::println("ClassDeclaration");
        e->codegen(Type::sir);
    }
    // typedef
    else if (TypedefDeclaration* tdef = declaration->isTypedefDeclaration())
    {
        Logger::println("TypedefDeclaration");
        DtoTypeInfoOf(tdef->type, false);
    }
    // attribute declaration
    else if (AttribDeclaration* a = declaration->isAttribDeclaration())
    {
        Logger::println("AttribDeclaration");
        // choose the right set in case this is a conditional declaration
        Array *d = a->include(NULL, NULL);
        if (d)
            for (int i=0; i < d->dim; ++i)
            {
                DtoDeclarationExp((Dsymbol*)d->data[i]);
            }
    }
    // mixin declaration
    else if (TemplateMixin* m = declaration->isTemplateMixin())
    {
        Logger::println("TemplateMixin");
        for (int i=0; i < m->members->dim; ++i)
        {
            Dsymbol* mdsym = (Dsymbol*)m->members->data[i];
            DtoDeclarationExp(mdsym);
        }
    }
    // tuple declaration
    else if (TupleDeclaration* tupled = declaration->isTupleDeclaration())
    {
        Logger::println("TupleDeclaration");
        if(!tupled->isexp) {
            error(declaration->loc, "don't know how to handle non-expression tuple decls yet");
            assert(0);
        }

        assert(tupled->objects);
        for (int i=0; i < tupled->objects->dim; ++i)
        {
            DsymbolExp* exp = (DsymbolExp*)tupled->objects->data[i];
            DtoDeclarationExp(exp->s);
        }
    }
    // unsupported declaration
    else
    {
        error(declaration->loc, "Unimplemented Declaration type for DeclarationExp. kind: %s", declaration->kind());
        assert(0);
    }
    return NULL;
}

// does pretty much the same as DtoDeclarationExp, except it doesn't initialize, and only handles var declarations
LLValue* DtoRawVarDeclaration(VarDeclaration* var, LLValue* addr)
{
    // we don't handle globals with this one
    assert(!var->isDataseg());

    // we don't handle aliases either
    assert(!var->aliassym);

    // alloca if necessary
    LLValue* allocaval = NULL;
    if (!addr && (!var->ir.irLocal || !var->ir.irLocal->value))
    {
        addr = DtoAlloca(var->type, var->toChars());

        #ifndef DISABLE_DEBUG_INFO
        // add debug info
        if (global.params.symdebug)
            DtoDwarfLocalVariable(addr, var);
        #endif
    }

    // referenced by nested function?
#if DMDV2
    if (var->nestedrefs.dim)
#else
    if (var->nestedref)
#endif
    {
        assert(var->ir.irLocal);
        if(!var->ir.irLocal->value)
        {
            assert(addr);
            var->ir.irLocal->value = addr;
        }
        else
            assert(!addr || addr == var->ir.irLocal->value);

        DtoNestedInit(var);
    }
    // normal local variable
    else
    {
        // if this already has storage, it must've been handled already
        if (var->ir.irLocal && var->ir.irLocal->value) {
            if (addr && addr != var->ir.irLocal->value) {
                // This can happen, for example, in scope(exit) blocks which
                // are translated to IR multiple times.
                // That *should* only happen after the first one is completely done
                // though, so just set the address.
                IF_LOG {
                    Logger::println("Replacing LLVM address of %s", var->toChars());
                    LOG_SCOPE;
                    Logger::cout() << "Old val: " << *var->ir.irLocal->value << '\n';
                    Logger::cout() << "New val: " << *addr << '\n';
                }
                var->ir.irLocal->value = addr;
            }
            return addr;
        }

        assert(!var->ir.isSet());
        assert(addr);
        var->ir.irLocal = new IrLocal(var);
        var->ir.irLocal->value = addr;
    }

    // return the alloca
    return var->ir.irLocal->value;
}

/****************************************************************************************/
/*////////////////////////////////////////////////////////////////////////////////////////
//      INITIALIZER HELPERS
////////////////////////////////////////////////////////////////////////////////////////*/

LLConstant* DtoConstInitializer(Loc loc, Type* type, Initializer* init)
{
    LLConstant* _init = 0; // may return zero
    if (!init)
    {
        Logger::println("const default initializer for %s", type->toChars());
        _init = DtoConstExpInit(loc, type, type->defaultInit());
    }
    else if (ExpInitializer* ex = init->isExpInitializer())
    {
        Logger::println("const expression initializer");
        _init = DtoConstExpInit(loc, type, ex->exp);;
    }
    else if (StructInitializer* si = init->isStructInitializer())
    {
        Logger::println("const struct initializer");
        si->ad->codegen(Type::sir);
        return si->ad->ir.irStruct->createStructInitializer(si);
    }
    else if (ArrayInitializer* ai = init->isArrayInitializer())
    {
        Logger::println("const array initializer");
        _init = DtoConstArrayInitializer(ai);
    }
    else if (init->isVoidInitializer())
    {
        Logger::println("const void initializer");
        const LLType* ty = DtoType(type);
        _init = LLConstant::getNullValue(ty);
    }
    else {
        Logger::println("unsupported const initializer: %s", init->toChars());
    }
    return _init;
}

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

DValue* DtoInitializer(LLValue* target, Initializer* init)
{
    if (!init)
        return 0;
    else if (ExpInitializer* ex = init->isExpInitializer())
    {
        Logger::println("expression initializer");
        assert(ex->exp);
        return ex->exp->toElem(gIR);
    }
    else if (init->isVoidInitializer())
    {
        // do nothing
    }
    else {
        Logger::println("unsupported initializer: %s", init->toChars());
        assert(0);
    }
    return 0;
}

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

static LLConstant* expand_to_sarray(Type *base, Expression* exp)
{
    Logger::println("building type %s from expression (%s) of type %s", base->toChars(), exp->toChars(), exp->type->toChars());
    const LLType* dstTy = DtoType(base);
    if (Logger::enabled())
        Logger::cout() << "final llvm type requested: " << *dstTy << '\n';

    LLConstant* val = exp->toConstElem(gIR);

    Type* expbase = exp->type->toBasetype();
    Logger::println("expbase: %s", expbase->toChars());
    Type* t = base->toBasetype();

    LLSmallVector<size_t, 4> dims;

    while(1)
    {
        Logger::println("t: %s", t->toChars());
        if (t->equals(expbase))
            break;
        assert(t->ty == Tsarray);
        TypeSArray* tsa = (TypeSArray*)t;
        dims.push_back(tsa->dim->toInteger());
        assert(t->nextOf());
        t = t->nextOf()->toBasetype();
    }

    size_t i = dims.size();
    assert(i);

    std::vector<LLConstant*> inits;
    while (i--)
    {
        const LLArrayType* arrty = LLArrayType::get(val->getType(), dims[i]);
        inits.clear();
        inits.insert(inits.end(), dims[i], val);
        val = LLConstantArray::get(arrty, inits);
    }

    return val;
}

LLConstant* DtoConstExpInit(Loc loc, Type* type, Expression* exp)
{
    Type* expbase = exp->type->toBasetype();
    Type* base = type->toBasetype();

    // if not the same basetypes, we won't get the same llvm types either
    if (!expbase->equals(base))
    {
        if (base->ty == Tsarray)
        {
            if (base->nextOf()->toBasetype()->ty == Tvoid) {
                error(loc, "static arrays of voids have no default initializer");
                fatal();
            }
            Logger::println("type is a static array, building constant array initializer to single value");
            return expand_to_sarray(base, exp);
        }
        else
        {
            error("cannot yet convert default initializer %s to type %s to %s", exp->toChars(), exp->type->toChars(), type->toChars());
            fatal();
        }
        assert(0);
    }

    return exp->toConstElem(gIR);
}

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

void DtoAnnotation(const char* str)
{
    std::string s("CODE: ");
    s.append(str);
    char* p = &s[0];
    while (*p)
    {
        if (*p == '"')
            *p = '\'';
        ++p;
    }
    // create a noop with the code as the result name!
    // FIXME: this is const folded and eliminated immediately ... :/
    gIR->ir->CreateAnd(DtoConstSize_t(0),DtoConstSize_t(0),s.c_str());
}

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

LLConstant* DtoTypeInfoOf(Type* type, bool base)
{
#if DMDV2
    // FIXME: this is probably wrong, but it makes druntime's genobj.d compile!
    type = type->mutableOf()->merge(); // needed.. getTypeInfo does the same
#else
    type = type->merge(); // needed.. getTypeInfo does the same
#endif
    type->getTypeInfo(NULL);
    TypeInfoDeclaration* tidecl = type->vtinfo;
    assert(tidecl);
    tidecl->codegen(Type::sir);
    assert(tidecl->ir.irGlobal != NULL);
    assert(tidecl->ir.irGlobal->value != NULL);
    LLConstant* c = isaConstant(tidecl->ir.irGlobal->value);
    assert(c != NULL);
    if (base)
        return llvm::ConstantExpr::getBitCast(c, DtoType(Type::typeinfo->type));
    return c;
}

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

void DtoOverloadedIntrinsicName(TemplateInstance* ti, TemplateDeclaration* td, std::string& name)
{
    Logger::println("DtoOverloadedIntrinsicName");
    LOG_SCOPE;

    Logger::println("template instance: %s", ti->toChars());
    Logger::println("template declaration: %s", td->toChars());
    Logger::println("intrinsic name: %s", td->intrinsicName.c_str());

    // for now use the size in bits of the first template param in the instance
    assert(ti->tdtypes.dim == 1);
    Type* T = (Type*)ti->tdtypes.data[0];

    char prefix = T->isreal() ? 'f' : T->isintegral() ? 'i' : 0;
    if (!prefix) {
        ti->error("has invalid template parameter for intrinsic: %s", T->toChars());
        fatal(); // or LLVM asserts
    }

    char tmp[21]; // probably excessive, but covers a uint64_t
    sprintf(tmp, "%lu", (unsigned long) gTargetData->getTypeSizeInBits(DtoType(T)));

    // replace # in name with bitsize
    name = td->intrinsicName;

    std::string needle("#");
    size_t pos;
    while(std::string::npos != (pos = name.find(needle))) {
        if (pos > 0 && name[pos-1] == prefix) {
            // Properly prefixed, insert bitwidth.
            name.replace(pos, 1, tmp);
        } else {
            if (pos && (name[pos-1] == 'i' || name[pos-1] == 'f')) {
                // Wrong type character.
                ti->error("has invalid parameter type for intrinsic %s: %s is not a%s type",
                    name.c_str(), T->toChars(),
                    (name[pos-1] == 'i' ? "n integral" : " floating-point"));
            } else {
                // Just plain wrong. (Error in declaration, not instantiation)
                td->error("has an invalid intrinsic name: %s", name.c_str());
            }
            fatal(); // or LLVM asserts
        }
    }

    Logger::println("final intrinsic name: %s", name.c_str());
}

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

bool mustDefineSymbol(Dsymbol* s)
{
    if (FuncDeclaration* fd = s->isFuncDeclaration())
    {
        // we can't (and probably shouldn't?) define functions
        // that weren't semantic3'ed
        if (fd->semanticRun < 4)
            return false;

	if (fd->isArrayOp)
            return true;

        if (global.params.useAvailableExternally && fd->availableExternally) {
            // Emit extra functions if we're inlining.
            // These will get available_externally linkage,
            // so they shouldn't end up in object code.

            assert(fd->type->ty == Tfunction);
            TypeFunction* tf = (TypeFunction*) fd->type;
            // * If we define extra static constructors, static destructors
            //   and unittests they'll get registered to run, and we won't
            //   be calling them directly anyway.
            // * If it's a large function, don't emit it unnecessarily.
            //   Use DMD's canInline() to determine whether it's large.
            //   inlineCost() members have been changed to pay less attention
            //   to DMDs limitations, but still have some issues. The most glaring
            //   offenders are any kind of control flow statements other than
            //   'if' and 'return'.
            if (   !fd->isStaticCtorDeclaration()
                && !fd->isStaticDtorDeclaration()
                && !fd->isUnitTestDeclaration()
                && fd->canInline(true))
            {
                return true;
            }

            // This was only semantic'ed for inlining checks.
            // We won't be inlining this, so we only need to emit a declaration.
            return false;
        }
    }

    // Inlining checks may create some variable and class declarations
    // we don't need to emit.
    if (global.params.useAvailableExternally)
    {
        if (VarDeclaration* vd = s->isVarDeclaration())
            if (vd->availableExternally)
                return false;

        if (ClassDeclaration* cd = s->isClassDeclaration())
            if (cd->availableExternally)
                return false;
    }

    TemplateInstance* tinst = DtoIsTemplateInstance(s);
    if (tinst)
    {
        if (!opts::singleObj)
            return true;

        if (!tinst->emittedInModule)
        {
            gIR->seenTemplateInstances.insert(tinst);
            tinst->emittedInModule = gIR->dmodule;
        }
        return tinst->emittedInModule == gIR->dmodule;
    }

    return s->getModule() == gIR->dmodule;
}

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

bool needsTemplateLinkage(Dsymbol* s)
{
    return DtoIsTemplateInstance(s) && mustDefineSymbol(s);
}

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

bool hasUnalignedFields(Type* t)
{
    t = t->toBasetype();
    if (t->ty == Tsarray) {
        assert(t->nextOf()->size() % t->nextOf()->alignsize() == 0);
        return hasUnalignedFields(t->nextOf());
    } else if (t->ty != Tstruct)
        return false;

    TypeStruct* ts = (TypeStruct*)t;
    if (ts->unaligned)
        return (ts->unaligned == 2);

    StructDeclaration* sym = ts->sym;

    // go through all the fields and try to find something unaligned
    ts->unaligned = 2;
    for (int i = 0; i < sym->fields.dim; i++)
    {
        VarDeclaration* f = (VarDeclaration*)sym->fields.data[i];
        unsigned a = f->type->alignsize() - 1;
        if (((f->offset + a) & ~a) != f->offset)
            return true;
        else if (f->type->toBasetype()->ty == Tstruct && hasUnalignedFields(f->type))
            return true;
    }

    ts->unaligned = 1;
    return false;
}

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

IrModule * getIrModule(Module * M)
{
    if (M == NULL)
        M = gIR->func()->decl->getModule();
    assert(M && "null module");
    if (!M->ir.irModule)
        M->ir.irModule = new IrModule(M, M->srcfile->toChars());
    return M->ir.irModule;
}

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

size_t realignOffset(size_t offset, Type* type)
{
    size_t alignsize = type->alignsize();
    size_t alignedoffset = (offset + alignsize - 1) & ~(alignsize - 1);

    // if the aligned offset already matches the input offset
    // don't waste time checking things are ok!
    if (alignedoffset == offset)
        return alignedoffset;

    // we cannot get the llvm alignment if the type is still opaque, this can happen in some
    // forward reference situations, so when this happens we fall back to manual padding.
    // also handle arbitrary "by-value" opaques nested inside aggregates.
    const llvm::Type* T = DtoType(type);
    if (!T->isSized())
    {
        return offset;
    }

    // then we check against the llvm alignment
    size_t alignsize2 = gTargetData->getABITypeAlignment(T);

    // if it differs we need to insert manual padding as well
    if (alignsize != alignsize2)
    {
        assert(alignsize > alignsize2 && "this is not good, the D and LLVM "
            "type alignments differ, but LLVM's is bigger! This will break "
            "aggregate type mapping");
        // don't try and align the offset, and let the mappers pad 100% manually
        return offset;
    }

    // ok, we're good, llvm will align properly!
    return alignedoffset;
}

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

Type * stripModifiers( Type * type )
{
#if DMDV2
	Type *t = type;
	while (t->mod)
	{
		switch (t->mod)
		{
			case MODconst:
				t = type->cto;
				break;
			case MODshared:
				t = type->sto;
				break;
			case MODinvariant:
				t = type->ito;
				break;
			case MODshared | MODconst:
				t = type->scto;
				break;
			default:
				assert(0 && "Unhandled type modifier");
		}

		if (!t)
		{
			unsigned sz = type->sizeTy[type->ty];
			t = (Type *)malloc(sz);
			memcpy(t, type, sz);
			t->mod = 0;
			t->deco = NULL;
			t->arrayof = NULL;
			t->pto = NULL;
			t->rto = NULL;
			t->cto = NULL;
			t->ito = NULL;
			t->sto = NULL;
			t->scto = NULL;
			t->vtinfo = NULL;
			t = t->merge();

			t->fixTo(type);
			switch (type->mod)
			{
			    case MODconst:
				t->cto = type;
				break;

			    case MODinvariant:
				t->ito = type;
				break;

			    case MODshared:
				t->sto = type;
				break;

			    case MODshared | MODconst:
				t->scto = type;
				break;

			    default:
				assert(0);
			}
		}
	}
	return t;
#else
	return type;
#endif
}

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

LLValue* makeLValue(Loc& loc, DValue* value)
{
    Type* valueType = value->getType();
    bool needsMemory;
    LLValue* valuePointer;
    if (value->isIm()) {
        valuePointer = value->getRVal();
        needsMemory = !DtoIsPassedByRef(valueType);
    }
    else if (DVarValue* var = value->isVar()) {
        valuePointer = value->getLVal();
        needsMemory = false;
    }
    else if (value->isConst()) {
        valuePointer = value->getRVal();
        needsMemory = true;
    }
    else {
        valuePointer = DtoAlloca(valueType, ".makelvaluetmp");
        DVarValue var(valueType, valuePointer);
        DtoAssign(loc, &var, value);
        needsMemory = false;
    }

    if (needsMemory) {
        LLValue* tmp = DtoAlloca(valueType, ".makelvaluetmp");
        DtoStore(valuePointer, tmp);
        valuePointer = tmp;
    }

    return valuePointer;
}