C++ VarDeclaration::isField方法代码示例

/***************************************
 * Return true if struct is POD (Plain Old Data).
 * This is defined as:
 *      not nested
 *      no postblits, constructors, destructors, or assignment operators
 *      no fields with with any of those
 * The idea being these are compatible with C structs.
 *
 * Note that D struct constructors can mean POD, since there is always default
 * construction with no ctor, but that interferes with OPstrpar which wants it
 * on the stack in memory, not in registers.
 */
bool StructDeclaration::isPOD()
{
    if (enclosing || cpctor || postblit || ctor || dtor)
        return false;

    /* Recursively check any fields have a constructor.
     * We should cache the results of this.
     */
    for (size_t i = 0; i < fields.dim; i++)
    {
        Dsymbol *s = fields[i];
        VarDeclaration *v = s->isVarDeclaration();
        assert(v && v->isField());
        if (v->storage_class & STCref)
            continue;
        Type *tv = v->type->toBasetype();
        while (tv->ty == Tsarray)
        {   TypeSArray *ta = (TypeSArray *)tv;
            tv = tv->nextOf()->toBasetype();
        }
        if (tv->ty == Tstruct)
        {   TypeStruct *ts = (TypeStruct *)tv;
            StructDeclaration *sd = ts->sym;
            if (!sd->isPOD())
                return false;
        }
    }
    return true;
}

int StructDeclaration::needOpEquals()
{
#define X 0
    if (X) printf("StructDeclaration::needOpEquals() %s\n", toChars());

    if (hasIdentityEquals)
        goto Lneed;

#if 0
    if (isUnionDeclaration())
        goto Ldontneed;
#endif

    /* If any of the fields has an opEquals, then we
     * need it too.
     */
    for (size_t i = 0; i < fields.dim; i++)
    {
        Dsymbol *s = fields[i];
        VarDeclaration *v = s->isVarDeclaration();
        assert(v && v->isField());
        if (v->storage_class & STCref)
            continue;
        Type *tv = v->type->toBasetype();
#if 0
        if (tv->isfloating())
            goto Lneed;
        if (tv->ty == Tarray)
            goto Lneed;
        if (tv->ty == Tclass)
            goto Lneed;
#endif
        while (tv->ty == Tsarray)
        {   TypeSArray *ta = (TypeSArray *)tv;
            tv = tv->nextOf()->toBasetype();
        }
        if (tv->ty == Tstruct)
        {   TypeStruct *ts = (TypeStruct *)tv;
            StructDeclaration *sd = ts->sym;
            if (sd->needOpEquals())
                goto Lneed;
        }
    }
Ldontneed:
    if (X) printf("\tdontneed\n");
    return 0;

Lneed:
    if (X) printf("\tneed\n");
    return 1;
#undef X
}

 /* Returns:
  *  0       this member doesn't need further processing to determine struct size
  *  1       this member does
  */
 static int func(Dsymbol *s, void *param)
 {   SV *psv = (SV *)param;
     VarDeclaration *v = s->isVarDeclaration();
     if (v)
     {
         if (v->scope)
             v->semantic(NULL);
         if (v->storage_class & (STCstatic | STCextern | STCtls | STCgshared | STCmanifest | STCctfe | STCtemplateparameter))
             return 0;
         if (v->isField() && v->sem >= SemanticDone)
             return 0;
         return 1;
     }
     return 0;
 }

int StructDeclaration::needOpAssign()
{
#define X 0
    if (X) printf("StructDeclaration::needOpAssign() %s\n", toChars());

    if (hasIdentityAssign)
        goto Lneed;         // because has identity==elaborate opAssign

    if (dtor || postblit)
        goto Lneed;

    /* If any of the fields need an opAssign, then we
     * need it too.
     */
    for (size_t i = 0; i < fields.dim; i++)
    {
        Dsymbol *s = fields[i];
        VarDeclaration *v = s->isVarDeclaration();
        assert(v && v->isField());
        if (v->storage_class & STCref)
            continue;
        Type *tv = v->type->toBasetype();
        while (tv->ty == Tsarray)
        {   TypeSArray *ta = (TypeSArray *)tv;
            tv = tv->nextOf()->toBasetype();
        }
        if (tv->ty == Tstruct)
        {   TypeStruct *ts = (TypeStruct *)tv;
            StructDeclaration *sd = ts->sym;
            if (sd->needOpAssign())
                goto Lneed;
        }
    }
Ldontneed:
    if (X) printf("\tdontneed\n");
    return 0;

Lneed:
    if (X) printf("\tneed\n");
    return 1;
#undef X
}

            /* Returns:
             *  0       this member doesn't need further processing to determine struct size
             *  1       this member does
             */
            static int func(Dsymbol *s, void *param)
            {
                VarDeclaration *v = s->isVarDeclaration();
                if (v)
                {
                    /* Bugzilla 12799: enum a = ...; is a VarDeclaration and
                     * STCmanifest is already set in parssing stage. So we can
                     * check this before the semantic() call.
                     */
                    if (v->storage_class & STCmanifest)
                        return 0;

                    if (v->scope)
                        v->semantic(NULL);
                    if (v->storage_class & (STCstatic | STCextern | STCtls | STCgshared | STCmanifest | STCctfe | STCtemplateparameter))
                        return 0;
                    if (v->isField() && v->sem >= SemanticDone)
                        return 0;
                    return 1;
                }
                return 0;
            }

FuncDeclaration *AggregateDeclaration::buildDtor(Scope *sc)
{
    //printf("AggregateDeclaration::buildDtor() %s\n", toChars());
    Expression *e = NULL;

#if DMDV2
    for (size_t i = 0; i < fields.dim; i++)
    {
        Dsymbol *s = fields[i];
        VarDeclaration *v = s->isVarDeclaration();
        assert(v && v->isField());
        if (v->storage_class & STCref)
            continue;
        Type *tv = v->type->toBasetype();
        dinteger_t dim = 1;
        while (tv->ty == Tsarray)
        {   TypeSArray *ta = (TypeSArray *)tv;
            dim *= ((TypeSArray *)tv)->dim->toInteger();
            tv = tv->nextOf()->toBasetype();
        }
        if (tv->ty == Tstruct)
        {   TypeStruct *ts = (TypeStruct *)tv;
            StructDeclaration *sd = ts->sym;
            if (sd->dtor && dim)
            {   Expression *ex;

                // this.v
                ex = new ThisExp(0);
                ex = new DotVarExp(0, ex, v, 0);

                if (v->type->toBasetype()->ty == Tstruct)
                {   // this.v.dtor()
                    ex = new DotVarExp(0, ex, sd->dtor, 0);
                    ex = new CallExp(0, ex);
                }
                else
                {
                    // Typeinfo.destroy(cast(void*)&this.v);
                    Expression *ea = new AddrExp(0, ex);
                    ea = new CastExp(0, ea, Type::tvoid->pointerTo());

                    Expression *et = v->type->getTypeInfo(sc);
                    et = new DotIdExp(0, et, Id::destroy);

                    ex = new CallExp(0, et, ea);
                }
                e = Expression::combine(ex, e); // combine in reverse order
            }
        }
    }

    /* Build our own "destructor" which executes e
     */
    if (e)
    {   //printf("Building __fieldDtor()\n");
        DtorDeclaration *dd = new DtorDeclaration(loc, 0, Lexer::idPool("__fieldDtor"));
        dd->fbody = new ExpStatement(0, e);
        dtors.shift(dd);
        members->push(dd);
        dd->semantic(sc);
    }
#endif

    switch (dtors.dim)
    {
        case 0:
            return NULL;

        case 1:
            return dtors[0];

        default:
            e = NULL;
            for (size_t i = 0; i < dtors.dim; i++)
            {   FuncDeclaration *fd = dtors[i];
                Expression *ex = new ThisExp(0);
                ex = new DotVarExp(0, ex, fd, 0);
                ex = new CallExp(0, ex);
                e = Expression::combine(ex, e);
            }
            DtorDeclaration *dd = new DtorDeclaration(loc, 0, Lexer::idPool("__aggrDtor"));
            dd->fbody = new ExpStatement(0, e);
            members->push(dd);
            dd->semantic(sc);
            return dd;
    }
}

FuncDeclaration *StructDeclaration::buildOpEquals(Scope *sc)
{
    Dsymbol *eq = search_function(this, Id::eq);
    if (eq)
    {
        /* check identity opEquals exists
         */
        Type *tthis = type->constOf();
        Expression *er = new NullExp(loc, tthis);       // dummy rvalue
        Expression *el = new IdentifierExp(loc, Id::p); // dummy lvalue
        el->type = tthis;
        Expressions ar;  ar.push(er);
        Expressions al;  al.push(el);
        FuncDeclaration *f = NULL;

        unsigned errors = global.startGagging();    // Do not report errors, even if the
        unsigned oldspec = global.speculativeGag;   // template opAssign fbody makes it.
        global.speculativeGag = global.gag;
        sc = sc->push();
        sc->speculative = true;

                 f = resolveFuncCall(loc, sc, eq, NULL, er, &ar, 1);
        if (!f)  f = resolveFuncCall(loc, sc, eq, NULL, er, &al, 1);

        sc = sc->pop();
        global.speculativeGag = oldspec;
        global.endGagging(errors);

        if (f)
            return (f->storage_class & STCdisable) ? NULL : f;
        return NULL;
    }

    if (!needOpEquals())
        return NULL;

    //printf("StructDeclaration::buildOpEquals() %s\n", toChars());

    Parameters *parameters = new Parameters;
    parameters->push(new Parameter(STCin, type, Id::p, NULL));
    TypeFunction *tf = new TypeFunction(parameters, Type::tbool, 0, LINKd);
    tf->mod = MODconst;
    tf = (TypeFunction *)tf->semantic(loc, sc);

    FuncDeclaration *fop = new FuncDeclaration(loc, 0, Id::eq, STCundefined, tf);

    Expression *e = NULL;
    /* Do memberwise compare
     */
    //printf("\tmemberwise compare\n");
    for (size_t i = 0; i < fields.dim; i++)
    {
        Dsymbol *s = fields[i];
        VarDeclaration *v = s->isVarDeclaration();
        assert(v && v->isField());
        if (v->storage_class & STCref)
            assert(0);                  // what should we do with this?
        // this.v == s.v;
        EqualExp *ec = new EqualExp(TOKequal, loc,
            new DotVarExp(loc, new ThisExp(loc), v, 0),
            new DotVarExp(loc, new IdentifierExp(loc, Id::p), v, 0));
        if (e)
            e = new AndAndExp(loc, e, ec);
        else
            e = ec;
    }
    if (!e)
        e = new IntegerExp(loc, 1, Type::tbool);
    fop->fbody = new ReturnStatement(loc, e);

    members->push(fop);
    fop->addMember(sc, this, 1);

    sc = sc->push();
    sc->stc = 0;
    sc->linkage = LINKd;

    fop->semantic(sc);

    sc->pop();

    //printf("-StructDeclaration::buildOpEquals() %s\n", toChars());

    return fop;
}

FuncDeclaration *StructDeclaration::buildOpAssign(Scope *sc)
{
    Dsymbol *assign = search_function(this, Id::assign);
    if (assign)
    {
        if (FuncDeclaration *f = hasIdentityOpAssign(sc, assign))
            return f;
        // Even if non-identity opAssign is defined, built-in identity opAssign
        // will be defined. (Is this an exception of operator overloading rule?)
    }

    if (!needOpAssign())
        return NULL;

    //printf("StructDeclaration::buildOpAssign() %s\n", toChars());

    Parameters *fparams = new Parameters;
    fparams->push(new Parameter(STCnodtor, type, Id::p, NULL));
    Type *ftype = new TypeFunction(fparams, handle, FALSE, LINKd);
    ((TypeFunction *)ftype)->isref = 1;

    FuncDeclaration *fop = new FuncDeclaration(loc, 0, Id::assign, STCundefined, ftype);

    Expression *e = NULL;
    if (postblit)
    {   /* Swap:
         *    tmp = *this; *this = s; tmp.dtor();
         */
        //printf("\tswap copy\n");
        Identifier *idtmp = Lexer::uniqueId("__tmp");
        VarDeclaration *tmp;
        AssignExp *ec = NULL;
        if (dtor)
        {
            tmp = new VarDeclaration(0, type, idtmp, new VoidInitializer(0));
            tmp->noscope = 1;
            tmp->storage_class |= STCctfe;
            e = new DeclarationExp(0, tmp);
            ec = new AssignExp(0,
                new VarExp(0, tmp),
                new ThisExp(0)
                );
            ec->op = TOKblit;
            e = Expression::combine(e, ec);
        }
        ec = new AssignExp(0,
                new ThisExp(0),
                new IdentifierExp(0, Id::p));
        ec->op = TOKblit;
        e = Expression::combine(e, ec);
        if (dtor)
        {
            /* Instead of running the destructor on s, run it
             * on tmp. This avoids needing to copy tmp back in to s.
             */
            Expression *ec2 = new DotVarExp(0, new VarExp(0, tmp), dtor, 0);
            ec2 = new CallExp(0, ec2);
            e = Expression::combine(e, ec2);
        }
    }
    else
    {   /* Do memberwise copy
         */
        //printf("\tmemberwise copy\n");
        for (size_t i = 0; i < fields.dim; i++)
        {
            Dsymbol *s = fields[i];
            VarDeclaration *v = s->isVarDeclaration();
            assert(v && v->isField());
            // this.v = s.v;
            AssignExp *ec = new AssignExp(0,
                new DotVarExp(0, new ThisExp(0), v, 0),
                new DotVarExp(0, new IdentifierExp(0, Id::p), v, 0));
            e = Expression::combine(e, ec);
        }
    }
    Statement *s1 = new ExpStatement(0, e);

    /* Add:
     *   return this;
     */
    e = new ThisExp(0);
    Statement *s2 = new ReturnStatement(0, e);

    fop->fbody = new CompoundStatement(0, s1, s2);

    Dsymbol *s = fop;
    if (assign && assign->isTemplateDeclaration())
    {
        // Wrap a template around the function declaration
        TemplateParameters *tpl = new TemplateParameters();
        Dsymbols *decldefs = new Dsymbols();
        decldefs->push(s);
        TemplateDeclaration *tempdecl =
            new TemplateDeclaration(assign->loc, fop->ident, tpl, NULL, decldefs, 0);
        s = tempdecl;
    }
    members->push(s);
    s->addMember(sc, this, 1);
    this->hasIdentityAssign = 1;        // temporary mark identity assignable
//.........这里部分代码省略.........

FuncDeclaration *StructDeclaration::buildOpAssign(Scope *sc)
{
    if (FuncDeclaration *f = hasIdentityOpAssign(sc))
    {
        hasIdentityAssign = 1;
        return f;
    }
    // Even if non-identity opAssign is defined, built-in identity opAssign
    // will be defined.

    if (!needOpAssign())
        return NULL;

    //printf("StructDeclaration::buildOpAssign() %s\n", toChars());
    StorageClass stc = STCsafe | STCnothrow | STCpure;
    Loc declLoc = this->loc;
    Loc loc = Loc();    // internal code should have no loc to prevent coverage

    if (dtor || postblit)
    {
        if (dtor)
            stc = mergeFuncAttrs(stc, dtor->storage_class);
    }
    else
    {
        for (size_t i = 0; i < fields.dim; i++)
        {
            Dsymbol *s = fields[i];
            VarDeclaration *v = s->isVarDeclaration();
            assert(v && v->isField());
            if (v->storage_class & STCref)
                continue;
            Type *tv = v->type->toBasetype();
            while (tv->ty == Tsarray)
            {   TypeSArray *ta = (TypeSArray *)tv;
                tv = tv->nextOf()->toBasetype();
            }
            if (tv->ty == Tstruct)
            {   TypeStruct *ts = (TypeStruct *)tv;
                StructDeclaration *sd = ts->sym;
                if (FuncDeclaration *f = sd->hasIdentityOpAssign(sc))
                    stc = mergeFuncAttrs(stc, f->storage_class);
            }
        }
    }

    Parameters *fparams = new Parameters;
    fparams->push(new Parameter(STCnodtor, type, Id::p, NULL));
    Type *tf = new TypeFunction(fparams, handle, 0, LINKd, stc | STCref);

    FuncDeclaration *fop = new FuncDeclaration(declLoc, Loc(), Id::assign, stc, tf);

    Expression *e = NULL;
    if (stc & STCdisable)
    {
    }
    else if (dtor || postblit)
    {
        /* Do swap this and rhs
         *    tmp = this; this = s; tmp.dtor();
         */
        //printf("\tswap copy\n");
        Identifier *idtmp = Lexer::uniqueId("__tmp");
        VarDeclaration *tmp;
        AssignExp *ec = NULL;
        if (dtor)
        {
            tmp = new VarDeclaration(loc, type, idtmp, new VoidInitializer(loc));
            tmp->noscope = 1;
            tmp->storage_class |= STCctfe;
            e = new DeclarationExp(loc, tmp);
            ec = new AssignExp(loc,
                new VarExp(loc, tmp),
                new ThisExp(loc)
                );
            ec->op = TOKblit;
            e = Expression::combine(e, ec);
        }
        ec = new AssignExp(loc,
                new ThisExp(loc),
                new IdentifierExp(loc, Id::p));
        ec->op = TOKblit;
        e = Expression::combine(e, ec);
        if (dtor)
        {
            /* Instead of running the destructor on s, run it
             * on tmp. This avoids needing to copy tmp back in to s.
             */
            Expression *ec2 = new DotVarExp(loc, new VarExp(loc, tmp), dtor, 0);
            ec2 = new CallExp(loc, ec2);
            e = Expression::combine(e, ec2);
        }
    }
    else
    {
        /* Do memberwise copy
         */
        //printf("\tmemberwise copy\n");
        for (size_t i = 0; i < fields.dim; i++)
        {
//.........这里部分代码省略.........