C++ VarDeclaration::toChars方法代码示例

dt_t *StructInitializer::toDt()
{
    Dts dts;
    dt_t *dt;
    dt_t *d;
    dt_t **pdtend;
    unsigned offset;

    //printf("StructInitializer::toDt('%s')\n", toChars());
    dts.setDim(ad->fields.dim);
    dts.zero();

    for (size_t i = 0; i < vars.dim; i++)
    {
        VarDeclaration *v = vars[i];
        Initializer *val = value[i];

        //printf("vars[%d] = %s\n", i, v->toChars());

        for (size_t j = 0; 1; j++)
        {
            assert(j < dts.dim);
            //printf(" adfield[%d] = %s\n", j, (ad->fields[j])->toChars());
            if (ad->fields[j] == v)
            {
                if (dts[j])
                    error(loc, "field %s of %s already initialized", v->toChars(), ad->toChars());
                dts[j] = val->toDt();
                break;
            }
        }
    }

    dt = NULL;
    pdtend = &dt;
    offset = 0;
    for (size_t j = 0; j < dts.dim; j++)
    {
        VarDeclaration *v = ad->fields[j];

        d = dts[j];
        if (!d)
        {   // An instance specific initializer was not provided.
            // Look to see if there's a default initializer from the
            // struct definition
            if (v->init && v->init->isVoidInitializer())
                ;
            else if (v->init)
            {
                d = v->init->toDt();
            }
            else if (v->offset >= offset)
            {
                unsigned k;
                unsigned offset2 = v->offset + v->type->size();
                // Make sure this field does not overlap any explicitly
                // initialized field.
                for (k = j + 1; 1; k++)
                {
                    if (k == dts.dim)           // didn't find any overlap
                    {
                        v->type->toDt(&d);
                        break;
                    }
                    VarDeclaration *v2 = ad->fields[k];

                    if (v2->offset < offset2 && dts[k])
                        break;                  // overlap
                }
            }
        }
        if (d)
        {
            if (v->offset < offset)
                error(loc, "duplicate union initialization for %s", v->toChars());
            else
            {   size_t sz = dt_size(d);
                size_t vsz = v->type->size();
                size_t voffset = v->offset;

                if (sz > vsz)
                {   assert(v->type->ty == Tsarray && vsz == 0);
                    error(loc, "zero length array %s has non-zero length initializer", v->toChars());
                }

                unsigned dim = 1;
                for (Type *vt = v->type->toBasetype();
                     vt->ty == Tsarray;
                     vt = vt->nextOf()->toBasetype())
                {   TypeSArray *tsa = (TypeSArray *)vt;
                    dim *= tsa->dim->toInteger();
                }
                //printf("sz = %d, dim = %d, vsz = %d\n", sz, dim, vsz);
                assert(sz == vsz || sz * dim <= vsz);

                for (size_t i = 0; i < dim; i++)
                {
                    if (offset < voffset)
                        pdtend = dtnzeros(pdtend, voffset - offset);
                    if (!d)
//.........这里部分代码省略.........

void IrAggr::addFieldInitializers(
    llvm::SmallVectorImpl<llvm::Constant*>& constants,
    const VarInitMap& explicitInitializers,
    AggregateDeclaration* decl,
    unsigned& offset,
    bool populateInterfacesWithVtbls
    )
{
    if (ClassDeclaration* cd = decl->isClassDeclaration())
    {
        if (cd->baseClass)
        {
            addFieldInitializers(constants, explicitInitializers,
                cd->baseClass, offset, populateInterfacesWithVtbls);
        }
    }

    // Build up vector with one-to-one mapping to field indices.
    const size_t n = decl->fields.dim;
    llvm::SmallVector<VarInitConst, 16> data(n);

    // Fill in explicit initializers.
    for (size_t i = 0; i < n; ++i)
    {
        VarDeclaration* vd = decl->fields[i];
        VarInitMap::const_iterator expl = explicitInitializers.find(vd);
        if (expl != explicitInitializers.end())
            data[i] = *expl;
    }

    // Fill in implicit initializers
    for (size_t i = 0; i < n; i++)
    {
        if (data[i].first) continue;

        VarDeclaration* vd = decl->fields[i];

        /* Skip void initializers for unions. DMD bug 3991:
            union X
            {
                int   a = void;
                dchar b = 'a';
            }
        */
        if (decl->isUnionDeclaration() && vd->init && vd->init->isVoidInitializer())
            continue;

        unsigned vd_begin = vd->offset;
        unsigned vd_end = vd_begin + vd->type->size();

        /* Skip zero size fields like zero-length static arrays, LDC issue 812:
            class B {
                ubyte[0] test;
            }
        */
        if (vd_begin == vd_end)
            continue;

        // make sure it doesn't overlap any explicit initializers.
        bool overlaps = false;
        if (type->ty == Tstruct)
        {
            // Only structs and unions can have overlapping fields.
            for (size_t j = 0; j < n; ++j)
            {
                if (i == j || !data[j].first)
                    continue;

                VarDeclaration* it = decl->fields[j];
                unsigned f_begin = it->offset;
                unsigned f_end = f_begin + it->type->size();

                if (vd_begin >= f_end || vd_end <= f_begin)
                    continue;

                overlaps = true;
                break;
            }
        }
        // add if no overlap found
        if (!overlaps)
        {
            IF_LOG Logger::println("Implicit initializer: %s @+%u", vd->toChars(), vd->offset);
            LOG_SCOPE;

            data[i].first = vd;
            data[i].second = get_default_initializer(vd, NULL);
        }
    }

    // Sort data array by offset.
    // TODO: Figure out whether this is really necessary, fields should already
    // be in offset order. Not having do do this would mean we could use a plain
    // llvm::Constant* vector for initializers and avoid all the VarInitConst business.
    std::sort(data.begin(), data.end(), struct_init_data_sort);

    // build array of constants and make sure explicit zero padding is inserted when necessary.
    for (size_t i = 0; i < n; i++)
    {
        VarDeclaration* vd = data[i].first;
//.........这里部分代码省略.........

void AliasDeclaration::semantic(Scope *sc)
{
    //printf("AliasDeclaration::semantic() %s\n", toChars());
    if (aliassym)
    {
        if (aliassym->isTemplateInstance())
            aliassym->semantic(sc);
        return;
    }
    this->inSemantic = 1;

#if DMDV1   // don't really know why this is here
    if (storage_class & STCconst)
        error("cannot be const");
#endif

    storage_class |= sc->stc & STCdeprecated;

    // Given:
    //  alias foo.bar.abc def;
    // it is not knowable from the syntax whether this is an alias
    // for a type or an alias for a symbol. It is up to the semantic()
    // pass to distinguish.
    // If it is a type, then type is set and getType() will return that
    // type. If it is a symbol, then aliassym is set and type is NULL -
    // toAlias() will return aliasssym.

    Dsymbol *s;
    Type *t;
    Expression *e;

    /* This section is needed because resolve() will:
     *   const x = 3;
     *   alias x y;
     * try to alias y to 3.
     */
    s = type->toDsymbol(sc);
    if (s
#if DMDV2
`       && ((s->getType() && type->equals(s->getType())) || s->isEnumMember())
#endif
        )
        goto L2;                        // it's a symbolic alias

#if DMDV2
    type = type->addStorageClass(storage_class);
    if (storage_class & (STCref | STCnothrow | STCpure | STCdisable))
    {   // For 'ref' to be attached to function types, and picked
        // up by Type::resolve(), it has to go into sc.
        sc = sc->push();
        sc->stc |= storage_class & (STCref | STCnothrow | STCpure | STCshared | STCdisable);
        type->resolve(loc, sc, &e, &t, &s);
        sc = sc->pop();
    }
    else
#endif
        type->resolve(loc, sc, &e, &t, &s);
    if (s)
    {
        goto L2;
    }
    else if (e)
    {
        // Try to convert Expression to Dsymbol
        if (e->op == TOKvar)
        {   s = ((VarExp *)e)->var;
            goto L2;
        }
        else if (e->op == TOKfunction)
        {   s = ((FuncExp *)e)->fd;
            goto L2;
        }
        else
        {   error("cannot alias an expression %s", e->toChars());
            t = e->type;
        }
    }
    else if (t)
    {
        type = t;
    }
    if (overnext)
        ScopeDsymbol::multiplyDefined(0, this, overnext);
    this->inSemantic = 0;
    return;

  L2:
    //printf("alias is a symbol %s %s\n", s->kind(), s->toChars());
    type = NULL;
    VarDeclaration *v = s->isVarDeclaration();
    if (0 && v && v->linkage == LINKdefault)
    {
        error("forward reference of %s", v->toChars());
        s = NULL;
    }
    else
    {
        FuncDeclaration *f = s->toAlias()->isFuncDeclaration();
        if (f)
        {
//.........这里部分代码省略.........

/***************************************
 * Fit elements[] to the corresponding type of field[].
 * Input:
 *      loc
 *      sc
 *      elements    The explicit arguments that given to construct object.
 *      stype       The constructed object type.
 * Returns false if any errors occur.
 * Otherwise, returns true and elements[] are rewritten for the output.
 */
bool StructDeclaration::fit(Loc loc, Scope *sc, Expressions *elements, Type *stype)
{
    if (!elements)
        return true;

    size_t nfields = fields.dim - isNested();
    size_t offset = 0;
    for (size_t i = 0; i < elements->dim; i++)
    {
        Expression *e = (*elements)[i];
        if (!e)
            continue;

        e = resolveProperties(sc, e);
        if (i >= nfields)
        {
            if (i == fields.dim - 1 && isNested() && e->op == TOKnull)
            {
                // CTFE sometimes creates null as hidden pointer; we'll allow this.
                continue;
            }
            ::error(loc, "more initializers than fields (%d) of %s", nfields, toChars());
            return false;
        }
        VarDeclaration *v = fields[i];
        if (v->offset < offset)
        {
            ::error(loc, "overlapping initialization for %s", v->toChars());
            return false;
        }
        offset = (unsigned)(v->offset + v->type->size());

        Type *t = v->type;
        if (stype)
            t = t->addMod(stype->mod);
        Type *origType = t;
        Type *tb = t->toBasetype();

        /* Look for case of initializing a static array with a too-short
         * string literal, such as:
         *  char[5] foo = "abc";
         * Allow this by doing an explicit cast, which will lengthen the string
         * literal.
         */
        if (e->op == TOKstring && tb->ty == Tsarray)
        {
            StringExp *se = (StringExp *)e;
            Type *typeb = se->type->toBasetype();
            TY tynto = tb->nextOf()->ty;
            if (!se->committed &&
                (typeb->ty == Tarray || typeb->ty == Tsarray) &&
                (tynto == Tchar || tynto == Twchar || tynto == Tdchar) &&
                se->length((int)tb->nextOf()->size()) < ((TypeSArray *)tb)->dim->toInteger())
            {
                e = se->castTo(sc, t);
                goto L1;
            }
        }

        while (!e->implicitConvTo(t) && tb->ty == Tsarray)
        {
            /* Static array initialization, as in:
             *  T[3][5] = e;
             */
            t = tb->nextOf();
            tb = t->toBasetype();
        }
        if (!e->implicitConvTo(t))
            t = origType;  // restore type for better diagnostic

        e = e->implicitCastTo(sc, t);
    L1:
        if (e->op == TOKerror)
            return false;

        (*elements)[i] = e->isLvalue() ? callCpCtor(sc, e) : valueNoDtor(e);
    }
    return true;
}

void DtoCreateNestedContext(FuncDeclaration* fd) {
    Logger::println("DtoCreateNestedContext for %s", fd->toChars());
    LOG_SCOPE

    DtoCreateNestedContextType(fd);

    if (nestedCtx == NCArray) {
        // construct nested variables array
        if (!fd->nestedVars.empty())
        {
            Logger::println("has nested frame");
            // start with adding all enclosing parent frames until a static parent is reached
            int nparelems = 0;
            if (!fd->isStatic())
            {
                Dsymbol* par = fd->toParent2();
                while (par)
                {
                    if (FuncDeclaration* parfd = par->isFuncDeclaration())
                    {
                        nparelems += parfd->nestedVars.size();
                        // stop at first static
                        if (parfd->isStatic())
                            break;
                    }
                    else if (par->isClassDeclaration())
                    {
                        // nothing needed
                    }
                    else
                    {
                        break;
                    }

                    par = par->toParent2();
                }
            }
            int nelems = fd->nestedVars.size() + nparelems;

            // make array type for nested vars
            LLType* nestedVarsTy = LLArrayType::get(getVoidPtrType(), nelems);

            // alloca it
            // FIXME align ?
            LLValue* nestedVars = DtoRawAlloca(nestedVarsTy, 0, ".nested_vars");

            IrFunction* irfunction = fd->ir.irFunc;

            // copy parent frame into beginning
            if (nparelems)
            {
                LLValue* src = irfunction->nestArg;
                if (!src)
                {
                    assert(irfunction->thisArg);
                    assert(fd->isMember2());
                    LLValue* thisval = DtoLoad(irfunction->thisArg);
                    ClassDeclaration* cd = fd->isMember2()->isClassDeclaration();
                    assert(cd);
                    assert(cd->vthis);
                    src = DtoLoad(DtoGEPi(thisval, 0,cd->vthis->ir.irField->index, ".vthis"));
                } else {
                    src = DtoLoad(src);
                }
                DtoMemCpy(nestedVars, src, DtoConstSize_t(nparelems*PTRSIZE),
                    getABITypeAlign(getVoidPtrType()));
            }

            // store in IrFunction
            irfunction->nestedVar = nestedVars;

            // go through all nested vars and assign indices
            int idx = nparelems;
            for (std::set<VarDeclaration*>::iterator i=fd->nestedVars.begin(); i!=fd->nestedVars.end(); ++i)
            {
                VarDeclaration* vd = *i;
                if (!vd->ir.irLocal)
                    vd->ir.irLocal = new IrLocal(vd);

                if (vd->isParameter())
                {
                    Logger::println("nested param: %s", vd->toChars());
                    LLValue* gep = DtoGEPi(nestedVars, 0, idx);
                    LLValue* val = DtoBitCast(vd->ir.irLocal->value, getVoidPtrType());
                    DtoAlignedStore(val, gep);
                }
                else
                {
                    Logger::println("nested var:   %s", vd->toChars());
                }

                vd->ir.irLocal->nestedIndex = idx++;
            }
        }
    }
    else if (nestedCtx == NCHybrid) {
        // construct nested variables array
        if (!fd->nestedVars.empty())
        {
            IrFunction* irfunction = fd->ir.irFunc;
//.........这里部分代码省略.........

void ClassDeclaration::semantic(Scope *sc)
{
    //printf("ClassDeclaration::semantic(%s), type = %p, sizeok = %d, this = %p\n", toChars(), type, sizeok, this);
    //printf("\tparent = %p, '%s'\n", sc->parent, sc->parent ? sc->parent->toChars() : "");
    //printf("sc->stc = %x\n", sc->stc);

    //{ static int n;  if (++n == 20) *(char*)0=0; }

    if (!ident)         // if anonymous class
    {   const char *id = "__anonclass";

        ident = Identifier::generateId(id);
    }

    if (!sc)
        sc = scope;
    if (!parent && sc->parent && !sc->parent->isModule())
        parent = sc->parent;

    type = type->semantic(loc, sc);
    handle = type;

    if (!members)               // if opaque declaration
    {   //printf("\tclass '%s' is forward referenced\n", toChars());
        return;
    }
    if (symtab)
    {   if (sizeok == SIZEOKdone || !scope)
        {   //printf("\tsemantic for '%s' is already completed\n", toChars());
            return;             // semantic() already completed
        }
    }
    else
        symtab = new DsymbolTable();

    Scope *scx = NULL;
    if (scope)
    {   sc = scope;
        scx = scope;            // save so we don't make redundant copies
        scope = NULL;
    }
    unsigned dprogress_save = Module::dprogress;
    int errors = global.errors;

    if (sc->stc & STCdeprecated)
    {
        isdeprecated = true;
    }
    userAttributes = sc->userAttributes;

    if (sc->linkage == LINKcpp)
        error("cannot create C++ classes");

    // Expand any tuples in baseclasses[]
    for (size_t i = 0; i < baseclasses->dim; )
    {
        BaseClass *b = (*baseclasses)[i];

        unsigned oldgag = global.gag;
        if (global.isSpeculativeGagging() && !isSpeculative())
            global.gag = 0;
        b->type = b->type->semantic(loc, sc);
        global.gag = oldgag;

        Type *tb = b->type->toBasetype();

        if (tb->ty == Ttuple)
        {   TypeTuple *tup = (TypeTuple *)tb;
            PROT protection = b->protection;
            baseclasses->remove(i);
            size_t dim = Parameter::dim(tup->arguments);
            for (size_t j = 0; j < dim; j++)
            {   Parameter *arg = Parameter::getNth(tup->arguments, j);
                b = new BaseClass(arg->type, protection);
                baseclasses->insert(i + j, b);
            }
        }
        else
            i++;
    }

    // See if there's a base class as first in baseclasses[]
    if (baseclasses->dim)
    {   TypeClass *tc;
        BaseClass *b;
        Type *tb;

        b = (*baseclasses)[0];
        //b->type = b->type->semantic(loc, sc);
        tb = b->type->toBasetype();
        if (tb->ty != Tclass)
        {   if (b->type != Type::terror)
                error("base type must be class or interface, not %s", b->type->toChars());
            baseclasses->remove(0);
        }
        else
        {
            tc = (TypeClass *)(tb);

            if (tc->sym->isDeprecated())
//.........这里部分代码省略.........

Expression *StructInitializer::fill(Scope *sc, Type *t, NeedInterpret needInterpret)
{
    //printf("StructInitializer::fill(sc = %p, '%s')\n", sc, toChars());
    assert(t->ty == Tstruct);
    StructDeclaration *sd = ((TypeStruct *)t)->sym;
    sd->size(loc);
    if (sd->sizeok != SIZEOKdone)
        return new ErrorExp();
    size_t nfields = sd->fields.dim - sd->isNested();

    Expressions *elements = new Expressions();
    elements->setDim(nfields);
    for (size_t i = 0; i < elements->dim; i++)
        (*elements)[i] = NULL;

    // Run semantic for explicitly given initializers
    bool errors = false;
    for (size_t fieldi = 0, i = 0; i < field.dim; i++)
    {
        if (Identifier *id = field[i])
        {
            Dsymbol *s = sd->search(loc, id, 0);
            if (!s)
            {
                s = sd->search_correct(id);
                if (s)
                    error(loc, "'%s' is not a member of '%s', did you mean '%s %s'?",
                          id->toChars(), sd->toChars(), s->kind(), s->toChars());
                else
                    error(loc, "'%s' is not a member of '%s'", id->toChars(), sd->toChars());
                return new ErrorExp();
            }
            s = s->toAlias();

            // Find out which field index it is
            for (fieldi = 0; 1; fieldi++)
            {
                if (fieldi >= nfields)
                {
                    error(loc, "%s.%s is not a per-instance initializable field",
                        sd->toChars(), s->toChars());
                    return new ErrorExp();
                }
                if (s == sd->fields[fieldi])
                    break;
            }
        }
        else if (fieldi >= nfields)
        {
            error(loc, "too many initializers for %s", sd->toChars());
            return new ErrorExp();
        }

        VarDeclaration *vd = sd->fields[fieldi];
        if ((*elements)[fieldi])
        {
            error(loc, "duplicate initializer for field '%s'", vd->toChars());
            errors = true;
            continue;
        }
        for (size_t j = 0; j < nfields; j++)
        {
            VarDeclaration *v2 = sd->fields[j];
            bool overlap = (vd->offset < v2->offset + v2->type->size() &&
                            v2->offset < vd->offset + vd->type->size());
            if (overlap && (*elements)[j])
            {
                error(loc, "overlapping initialization for field %s and %s",
                    v2->toChars(), vd->toChars());
                errors = true;
                continue;
            }
        }

        assert(sc);
        Initializer *iz = value[i];
        iz = iz->semantic(sc, vd->type->addMod(t->mod), needInterpret);
        Expression *ex = iz->toExpression();
        if (ex->op == TOKerror)
        {
            errors = true;
            continue;
        }
        value[i] = iz;
        (*elements)[fieldi] = ex;
        ++fieldi;
    }
    if (errors)
        return new ErrorExp();

    // Fill in missing any elements with default initializers
    for (size_t i = 0; i < elements->dim; i++)
    {
        if ((*elements)[i])
            continue;
        VarDeclaration *vd = sd->fields[i];
        VarDeclaration *vx = vd;
        if (vd->init && vd->init->isVoidInitializer())
            vx = NULL;
        // Find overlapped fields with the hole [vd->offset .. vd->offset->size()].
//.........这里部分代码省略.........

void IrStruct::addBaseClassInits(
    std::vector<llvm::Constant*>& constants,
    ClassDeclaration* base,
    size_t& offset,
    size_t& field_index)
{
    if (base->baseClass)
    {
        addBaseClassInits(constants, base->baseClass, offset, field_index);
    }

    IrTypeClass* tc = stripModifiers(base->type)->irtype->isClass();
    assert(tc);

    // go through fields
    IrTypeAggr::iterator it;
    for (it = tc->def_begin(); it != tc->def_end(); ++it)
    {
        VarDeclaration* vd = *it;

        IF_LOG Logger::println("Adding default field %s %s (+%u)", vd->type->toChars(), vd->toChars(), vd->offset);
        LOG_SCOPE;

        assert(vd->offset >= offset && "default fields not sorted by offset");

        // get next aligned offset for this type
        size_t alignedoffset = realignOffset(offset, vd->type);

        // insert explicit padding?
        if (alignedoffset < vd->offset)
        {
            add_zeros(constants, vd->offset - alignedoffset);
        }

        // add default type
        constants.push_back(get_default_initializer(vd, vd->init));

        // advance offset to right past this field
        offset = vd->offset + vd->type->size();
    }

    // has interface vtbls?
    if (base->vtblInterfaces && base->vtblInterfaces->dim > 0)
    {
        // false when it's not okay to use functions from super classes
        bool newinsts = (base == aggrdecl->isClassDeclaration());

        size_t inter_idx = interfacesWithVtbls.size();

        offset = (offset + PTRSIZE - 1) & ~(PTRSIZE - 1);

        ArrayIter<BaseClass> it2(*base->vtblInterfaces);
        for (; !it2.done(); it2.next())
        {
            BaseClass* b = it2.get();
            constants.push_back(getInterfaceVtbl(b, newinsts, inter_idx));
            offset += PTRSIZE;

            // add to the interface list
            interfacesWithVtbls.push_back(b);
            inter_idx++;
        }
    }
}

/***************************************
 * Fill out remainder of elements[] with default initializers for fields[].
 * Input:
 *      loc
 *      elements    explicit arguments which given to construct object.
 *      ctorinit    true if the elements will be used for default initialization.
 * Returns false if any errors occur.
 * Otherwise, returns true and the missing arguments will be pushed in elements[].
 */
bool StructDeclaration::fill(Loc loc, Expressions *elements, bool ctorinit)
{
    assert(sizeok == SIZEOKdone);
    size_t nfields = fields.dim - isNested();

    if (elements)
    {
        size_t dim = elements->dim;
        elements->setDim(nfields);
        for (size_t i = dim; i < nfields; i++)
            (*elements)[i] = NULL;
    }

    // Fill in missing any elements with default initializers
    for (size_t i = 0; i < nfields; i++)
    {
        if (elements && (*elements)[i])
            continue;
        VarDeclaration *vd = fields[i];
        VarDeclaration *vx = vd;
        if (vd->init && vd->init->isVoidInitializer())
            vx = NULL;
        // Find overlapped fields with the hole [vd->offset .. vd->offset->size()].
        size_t fieldi = i;
        for (size_t j = 0; j < nfields; j++)
        {
            if (i == j)
                continue;
            VarDeclaration *v2 = fields[j];
            bool overlap = (vd->offset < v2->offset + v2->type->size() &&
                            v2->offset < vd->offset + vd->type->size());
            if (!overlap)
                continue;

            if (elements)
            {
                if ((*elements)[j])
                {
                    vx = NULL;
                    break;
                }
            }
            else
            {
                vd->overlapped = true;
            }
            if (v2->init && v2->init->isVoidInitializer())
                continue;

            if (elements)
            {
                /* Prefer first found non-void-initialized field
                 * union U { int a; int b = 2; }
                 * U u;    // Error: overlapping initialization for field a and b
                 */
                if (!vx)
                    vx = v2, fieldi = j;
                else if (v2->init)
                {
                    ::error(loc, "overlapping initialization for field %s and %s",
                        v2->toChars(), vd->toChars());
                }
            }
            else
            {
                // Will fix Bugzilla 1432 by enabling this path always

                /* Prefer explicitly initialized field
                 * union U { int a; int b = 2; }
                 * U u;    // OK (u.b == 2)
                 */
                if (!vx || !vx->init && v2->init)
                    vx = v2, fieldi = j;
                else if (vx != vd &&
                    !(vx->offset < v2->offset + v2->type->size() &&
                      v2->offset < vx->offset + vx->type->size()))
                {
                    // Both vx and v2 fills vd, but vx and v2 does not overlap
                }
                else if (vx->init && v2->init)
                {
                    ::error(loc, "overlapping default initialization for field %s and %s",
                        v2->toChars(), vd->toChars());
                }
                else
                    assert(vx->init || !vx->init && !v2->init);
            }
        }
        if (elements && vx)
        {
            Expression *e;
//.........这里部分代码省略.........

void AggrTypeBuilder::addAggregate(AggregateDeclaration *ad)
{
    // mirror the ad->fields array but only fill in contributors
    const size_t n = ad->fields.dim;
    LLSmallVector<VarDeclaration*, 16> data(n, NULL);

    unsigned int errors = global.errors;

    // first fill in the fields with explicit initializers
    for (size_t index = 0; index < n; ++index)
    {
        VarDeclaration *field = ad->fields[index];

        // init is !null for explicit inits
        if (field->init != NULL && !field->init->isVoidInitializer())
        {
            IF_LOG Logger::println("adding explicit initializer for struct field %s",
                field->toChars());

            size_t f_size = field->type->size();
            size_t f_begin = field->offset;
            size_t f_end = f_begin + f_size;
            if (f_size == 0)
                continue;

            data[index] = field;

            // make sure there is no overlap
            for (size_t i = 0; i < index; i++)
            {
                if (data[i] != NULL)
                {
                    VarDeclaration* vd = data[i];
                    size_t v_begin = vd->offset;
                    size_t v_end = v_begin + vd->type->size();

                    if (v_begin >= f_end || v_end <= f_begin)
                        continue;

                    ad->error(vd->loc, "has overlapping initialization for %s and %s",
                        field->toChars(), vd->toChars());
                }
            }
        }
    }

    if (errors != global.errors)
    {
        // There was an overlapping initialization.
        // Return if errors are gagged otherwise abort.
        if (global.gag) return;
        fatal();
    }

    // fill in default initializers
    for (size_t index = 0; index < n; ++index)
    {
        if (data[index])
            continue;
        VarDeclaration *field = ad->fields[index];

        size_t f_size = field->type->size();
        size_t f_begin = field->offset;
        size_t f_end = f_begin + f_size;
        if (f_size == 0)
            continue;

        // make sure it doesn't overlap anything explicit
        bool overlaps = false;
        for (size_t i = 0; i < n; i++)
        {
            if (data[i])
            {
                size_t v_begin = data[i]->offset;
                size_t v_end = v_begin + data[i]->type->size();

                if (v_begin >= f_end || v_end <= f_begin)
                    continue;

                overlaps = true;
                break;
            }
        }

        // if no overlap was found, add the default initializer
        if (!overlaps)
        {
            IF_LOG Logger::println("adding default initializer for struct field %s",
                field->toChars());
            data[index] = field;
        }
    }

    //
    // ok. now we can build a list of llvm types. and make sure zeros are inserted if necessary.
    //

    // first we sort the list by offset
    std::sort(data.begin(), data.end(), var_offset_sort_cb);

//.........这里部分代码省略.........

/***************************************
 * Fill out remainder of elements[] with default initializers for fields[].
 * Input:
 *      loc
 *      elements    explicit arguments which given to construct object.
 *      ctorinit    true if the elements will be used for default initialization.
 * Returns false if any errors occur.
 * Otherwise, returns true and the missing arguments will be pushed in elements[].
 */
bool StructDeclaration::fill(Loc loc, Expressions *elements, bool ctorinit)
{
    //printf("StructDeclaration::fill() %s\n", toChars());
    assert(sizeok == SIZEOKdone);
    size_t nfields = fields.dim - isNested();
    bool errors = false;

    if (elements)
    {
        size_t dim = elements->dim;
        elements->setDim(nfields);
        for (size_t i = dim; i < nfields; i++)
            (*elements)[i] = NULL;
    }

    // Fill in missing any elements with default initializers
    for (size_t i = 0; i < nfields; i++)
    {
        if (elements && (*elements)[i])
            continue;
        VarDeclaration *vd = fields[i];
        VarDeclaration *vx = vd;
        if (vd->init && vd->init->isVoidInitializer())
            vx = NULL;
        // Find overlapped fields with the hole [vd->offset .. vd->offset->size()].
        size_t fieldi = i;
        for (size_t j = 0; j < nfields; j++)
        {
            if (i == j)
                continue;
            VarDeclaration *v2 = fields[j];
            bool overlap = (vd->offset < v2->offset + v2->type->size() &&
                            v2->offset < vd->offset + vd->type->size());
            if (!overlap)
                continue;

            // vd and v2 are overlapping. If either has destructors, postblits, etc., then error
            //printf("overlapping fields %s and %s\n", vd->toChars(), v2->toChars());

            VarDeclaration *v = vd;
            for (int k = 0; k < 2; ++k, v = v2)
            {
                Type *tv = v->type->baseElemOf();
                Dsymbol *sv = tv->toDsymbol(NULL);
                if (sv && !errors)
                {
                    StructDeclaration *sd = sv->isStructDeclaration();
                    if (sd && (sd->dtor || sd->inv || sd->postblit))
                    {
                        error("destructors, postblits and invariants are not allowed in overlapping fields %s and %s", vd->toChars(), v2->toChars());
                        errors = true;
                        break;
                    }
                }
            }

            if (elements)
            {
                if ((*elements)[j])
                {
                    vx = NULL;
                    break;
                }
            }
            else
            {
                vd->overlapped = true;
            }
            if (v2->init && v2->init->isVoidInitializer())
                continue;

            if (elements)
            {
                /* Prefer first found non-void-initialized field
                 * union U { int a; int b = 2; }
                 * U u;    // Error: overlapping initialization for field a and b
                 */
                if (!vx)
                    vx = v2, fieldi = j;
                else if (v2->init)
                {
                    ::error(loc, "overlapping initialization for field %s and %s",
                        v2->toChars(), vd->toChars());
                }
            }
            else
            {
                // Will fix Bugzilla 1432 by enabling this path always

                /* Prefer explicitly initialized field
                 * union U { int a; int b = 2; }
//.........这里部分代码省略.........

void StructDeclaration::toDt(dt_t **pdt)
{
    if (zeroInit)
    {
        dtnzeros(pdt, structsize);
        return;
    }

    unsigned offset;
    dt_t *dt;
    dt_t *sdt = NULL;

    //printf("StructDeclaration::toDt(), this='%s'\n", toChars());
    offset = 0;

    // Note equivalence of this loop to class's
    for (size_t i = 0; i < fields.dim; i++)
    {
        VarDeclaration *v = fields[i];
        //printf("\tfield '%s' voffset %d, offset = %d\n", v->toChars(), v->offset, offset);
        dt = NULL;
        int sz;

        if (v->storage_class & STCref)
        {
            sz = PTRSIZE;
            if (v->offset >= offset)
                dtnzeros(&dt, sz);
        }
        else
        {
            sz = v->type->size();
            Initializer *init = v->init;
            if (init)
            {   //printf("\t\thas initializer %s\n", init->toChars());
                ExpInitializer *ei = init->isExpInitializer();
                Type *tb = v->type->toBasetype();
                if (init->isVoidInitializer())
                    ;
                else if (ei && tb->ty == Tsarray)
                    ((TypeSArray *)tb)->toDtElem(&dt, ei->exp);
                else
                    dt = init->toDt();
            }
            else if (v->offset >= offset)
                v->type->toDt(&dt);
        }
        if (dt)
        {
            if (v->offset < offset)
                error("overlapping initialization for struct %s.%s", toChars(), v->toChars());
            else
            {
                if (offset < v->offset)
                    dtnzeros(&sdt, v->offset - offset);
                dtcat(&sdt, dt);
                offset = v->offset + sz;
            }
        }
    }

    if (offset < structsize)
        dtnzeros(&sdt, structsize - offset);
#ifdef IN_GCC
    dtcontainer(pdt, type, sdt);
#else
    dtcat(pdt, sdt);
#endif
    dt_optimize(*pdt);
}

static void DtoCreateNestedContextType(FuncDeclaration* fd) {
    Logger::println("DtoCreateNestedContextType for %s", fd->toChars());
    LOG_SCOPE

    DtoDeclareFunction(fd);

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

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

    // construct nested variables array
    if (!fd->nestedVars.empty())
    {
        Logger::println("has nested frame");
        // start with adding all enclosing parent frames until a static parent is reached

        LLStructType* innerFrameType = NULL;
        unsigned depth = -1;
        if (!fd->isStatic()) {
            if (FuncDeclaration* parfd = getParentFunc(fd, true)) {
                // Make sure the parent has already been analyzed.
                DtoCreateNestedContextType(parfd);

                innerFrameType = parfd->ir.irFunc->frameType;
                if (innerFrameType)
                    depth = parfd->ir.irFunc->depth;
            }
        }
        fd->ir.irFunc->depth = ++depth;

        Logger::cout() << "Function " << fd->toChars() << " has depth " << depth << '\n';

        typedef std::vector<LLType*> TypeVec;
        TypeVec types;
        if (depth != 0) {
            assert(innerFrameType);
            // Add frame pointer types for all but last frame
            if (depth > 1) {
                for (unsigned i = 0; i < (depth - 1); ++i) {
                    types.push_back(innerFrameType->getElementType(i));
                }
            }
            // Add frame pointer type for last frame
            types.push_back(LLPointerType::getUnqual(innerFrameType));
        }

        if (Logger::enabled() && depth != 0) {
            Logger::println("Frame types: ");
            LOG_SCOPE;
            for (TypeVec::iterator i = types.begin(); i != types.end(); ++i)
                Logger::cout() << **i << '\n';
        }

        // Add the direct nested variables of this function, and update their indices to match.
        // TODO: optimize ordering for minimal space usage?
        for (std::set<VarDeclaration*>::iterator i=fd->nestedVars.begin(); i!=fd->nestedVars.end(); ++i)
        {
            VarDeclaration* vd = *i;
            if (!vd->ir.irLocal)
                vd->ir.irLocal = new IrLocal(vd);

            vd->ir.irLocal->nestedIndex = types.size();
            vd->ir.irLocal->nestedDepth = depth;
            if (vd->isParameter()) {
                // Parameters will have storage associated with them (to handle byref etc.),
                // so handle those cases specially by storing a pointer instead of a value.
                const IrParameter* irparam = vd->ir.irParam;
                const bool refout = vd->storage_class & (STCref | STCout);
                const bool lazy = vd->storage_class & STClazy;
                const bool byref = irparam->arg->byref;
                const bool isVthisPtr = irparam->isVthis && !byref;
                if (!(refout || (byref && !lazy)) || isVthisPtr) {
                    // This will be copied to the nesting frame.
                    if (lazy)
                        types.push_back(irparam->value->getType()->getContainedType(0));
                    else
                        types.push_back(DtoType(vd->type));
                } else {
                    types.push_back(irparam->value->getType());
                }
            } else if (isSpecialRefVar(vd)) {
                types.push_back(DtoType(vd->type->pointerTo()));
            } else {
                types.push_back(DtoType(vd->type));
            }
            if (Logger::enabled()) {
                Logger::cout() << "Nested var '" << vd->toChars() <<
                    "' of type " << *types.back() << "\n";
            }
        }
//.........这里部分代码省略.........

//.........这里部分代码省略.........
    }

    if (vthis)
    {
        assert(!vthis->csym);
        sthis = vthis->toSymbol();
        irs.sthis = sthis;
        if (!(f->Fflags3 & Fnested))
            f->Fflags3 |= Fmember;
    }

    Symbol **params;

    // Estimate number of parameters, pi
    size_t pi = (v_arguments != NULL);
    if (parameters)
        pi += parameters->dim;
    // Allow extra 2 for sthis and shidden
    params = (Symbol **)alloca((pi + 2) * sizeof(Symbol *));

    // Get the actual number of parameters, pi, and fill in the params[]
    pi = 0;
    if (v_arguments)
    {
        params[pi] = v_arguments->toSymbol();
        pi += 1;
    }
    if (parameters)
    {
        for (size_t i = 0; i < parameters->dim; i++)
        {   VarDeclaration *v = (*parameters)[i];
            if (v->csym)
            {
                error("compiler error, parameter '%s', bugzilla 2962?", v->toChars());
                assert(0);
            }
            params[pi + i] = v->toSymbol();
        }
        pi += parameters->dim;
    }

    if (reverse)
    {   // Reverse params[] entries
        for (size_t i = 0; i < pi/2; i++)
        {
            Symbol *sptmp = params[i];
            params[i] = params[pi - 1 - i];
            params[pi - 1 - i] = sptmp;
        }
    }

    if (shidden)
    {
#if 0
        // shidden becomes last parameter
        params[pi] = shidden;
#else
        // shidden becomes first parameter
        memmove(params + 1, params, pi * sizeof(params[0]));
        params[0] = shidden;
#endif
        pi++;
    }


    if (sthis)

void DtoCreateNestedContext(FuncDeclaration* fd) {
    Logger::println("DtoCreateNestedContext for %s", fd->toChars());
    LOG_SCOPE

    DtoCreateNestedContextType(fd);

    // construct nested variables array
    if (!fd->nestedVars.empty())
    {
        IrFunction* irfunction = fd->ir.irFunc;
        unsigned depth = irfunction->depth;
        LLStructType *frameType = irfunction->frameType;
        // Create frame for current function and append to frames list
        // FIXME: alignment ?
        LLValue* frame = 0;
        if (fd->needsClosure())
            frame = DtoGcMalloc(frameType, ".frame");
        else
            frame = DtoRawAlloca(frameType, 0, ".frame");

        // copy parent frames into beginning
        if (depth != 0) {
            LLValue* src = irfunction->nestArg;
            if (!src) {
                assert(irfunction->thisArg);
                assert(fd->isMember2());
                LLValue* thisval = DtoLoad(irfunction->thisArg);
                AggregateDeclaration* cd = fd->isMember2();
                assert(cd);
                assert(cd->vthis);
                Logger::println("Indexing to 'this'");
                if (cd->isStructDeclaration())
                    src = DtoExtractValue(thisval, cd->vthis->ir.irField->index, ".vthis");
                else
                    src = DtoLoad(DtoGEPi(thisval, 0, cd->vthis->ir.irField->index, ".vthis"));
            } else {
                src = DtoLoad(src);
            }
            if (depth > 1) {
                src = DtoBitCast(src, getVoidPtrType());
                LLValue* dst = DtoBitCast(frame, getVoidPtrType());
                DtoMemCpy(dst, src, DtoConstSize_t((depth-1) * PTRSIZE),
                    getABITypeAlign(getVoidPtrType()));
            }
            // Copy nestArg into framelist; the outer frame is not in the list of pointers
            src = DtoBitCast(src, frameType->getContainedType(depth-1));
            LLValue* gep = DtoGEPi(frame, 0, depth-1);
            DtoAlignedStore(src, gep);
        }

        // store context in IrFunction
        irfunction->nestedVar = frame;

        // go through all nested vars and assign addresses where possible.
        for (std::set<VarDeclaration*>::iterator i=fd->nestedVars.begin(); i!=fd->nestedVars.end(); ++i)
        {
            VarDeclaration* vd = *i;

            LLValue* gep = DtoGEPi(frame, 0, vd->ir.irLocal->nestedIndex, vd->toChars());
            if (vd->isParameter()) {
                Logger::println("nested param: %s", vd->toChars());
                LOG_SCOPE
                IrParameter* parm = vd->ir.irParam;

                if (parm->arg->byref)
                {
                    storeVariable(vd, gep);
                }
                else
                {
                    Logger::println("Copying to nested frame");
                    // The parameter value is an alloca'd stack slot.
                    // Copy to the nesting frame and leave the alloca for
                    // the optimizers to clean up.
                    DtoStore(DtoLoad(parm->value), gep);
                    gep->takeName(parm->value);
                    parm->value = gep;
                }
            } else {
                Logger::println("nested var:   %s", vd->toChars());
                assert(!vd->ir.irLocal->value);
                vd->ir.irLocal->value = gep;
            }

            if (global.params.symdebug) {
                LLSmallVector<LLValue*, 2> addr;
                dwarfOpOffset(addr, frameType, vd->ir.irLocal->nestedIndex);
                DtoDwarfLocalVariable(frame, vd, addr);
            }
        }
    }
}