C++ Expression::dyncast方法代码示例

void EnumDeclaration::semantic(Scope *sc)
{
    Type *t;
    Scope *sce;

    //printf("EnumDeclaration::semantic(sd = %p, '%s') %s\n", sc->scopesym, sc->scopesym->toChars(), toChars());
    //printf("EnumDeclaration::semantic() %s\n", toChars());
    if (!members)		// enum ident;
	return;

    if (!memtype && !isAnonymous())
    {	// Set memtype if we can to reduce fwd reference errors
	memtype = Type::tint32;	// case 1)  enum ident { ... }
    }

    if (symtab)			// if already done
    {	if (!scope)
	    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;
    }

    if (sc->stc & STCdeprecated)
	isdeprecated = 1;

    parent = sc->parent;

    /* The separate, and distinct, cases are:
     *  1. enum { ... }
     *  2. enum : memtype { ... }
     *  3. enum ident { ... }
     *  4. enum ident : memtype { ... }
     */

    if (memtype)
    {
	memtype = memtype->semantic(loc, sc);

	/* Check to see if memtype is forward referenced
	 */
	if (memtype->ty == Tenum)
	{   EnumDeclaration *sym = (EnumDeclaration *)memtype->toDsymbol(sc);
	    if (!sym->memtype || !sym->members || !sym->symtab || sym->scope)
	    {	// memtype is forward referenced, so try again later
		scope = scx ? scx : new Scope(*sc);
		scope->setNoFree();
		scope->module->addDeferredSemantic(this);
		printf("\tdeferring %s\n", toChars());
		return;
	    }
	}
#if 0	// Decided to abandon this restriction for D 2.0
	if (!memtype->isintegral())
	{   error("base type must be of integral type, not %s", memtype->toChars());
	    memtype = Type::tint32;
	}
#endif
    }

    type = type->semantic(loc, sc);
    if (isAnonymous())
    	sce = sc;
    else
    {	sce = sc->push(this);
	sce->parent = this;
    }
    if (members->dim == 0)
	error("enum %s must have at least one member", toChars());
    int first = 1;
    Expression *elast = NULL;
    for (int i = 0; i < members->dim; i++)
    {
	EnumMember *em = ((Dsymbol *)members->data[i])->isEnumMember();
	Expression *e;

	if (!em)
	    /* The e->semantic(sce) can insert other symbols, such as
	     * template instances and function literals.
	     */
	    continue;

	//printf("  Enum member '%s'\n",em->toChars());
	if (em->type)
	    em->type = em->type->semantic(em->loc, sce);
	e = em->value;
	if (e)
	{
	    assert(e->dyncast() == DYNCAST_EXPRESSION);
	    e = e->semantic(sce);
	    e = e->optimize(WANTvalue | WANTinterpret);
	    if (memtype)
	    {
		e = e->implicitCastTo(sce, memtype);
//.........这里部分代码省略.........

void EnumMember::semantic(Scope *sc)
{
    //printf("EnumMember::semantic() %s\n", toChars());
    if (errors || semanticRun >= PASSsemanticdone)
        return;
    if (semanticRun == PASSsemantic)
    {
        error("circular reference to enum member");
    Lerrors:
        errors = true;
        semanticRun = PASSsemanticdone;
        return;
    }
    assert(ed);
    ed->semantic(sc);
    if (ed->errors)
        goto Lerrors;

    if (errors || semanticRun >= PASSsemanticdone)
        return;

    semanticRun = PASSsemantic;
    if (scope)
        sc = scope;

    // The first enum member is special
    bool first = (this == (*ed->members)[0]);

    if (type)
    {
        type = type->semantic(loc, sc);
        assert(value);          // "type id;" is not a valid enum member declaration
    }

    if (value)
    {
        Expression *e = value;
        assert(e->dyncast() == DYNCAST_EXPRESSION);
        e = e->semantic(sc);
        e = resolveProperties(sc, e);
        e = e->ctfeInterpret();
        if (e->op == TOKerror)
            goto Lerrors;
        if (first && !ed->memtype && !ed->isAnonymous())
        {
            ed->memtype = e->type;
            if (ed->memtype->ty == Terror)
            {
                ed->errors = true;
                goto Lerrors;
            }
            if (ed->memtype->ty != Terror)
            {
                /* Bugzilla 11746: All of named enum members should have same type
                 * with the first member. If the following members were referenced
                 * during the first member semantic, their types should be unified.
                 */
                for (size_t i = 0; i < ed->members->dim; i++)
                {
                    EnumMember *em = (*ed->members)[i]->isEnumMember();
                    if (!em || em == this || em->semanticRun < PASSsemanticdone || em->type)
                        continue;

                    //printf("[%d] em = %s, em->semanticRun = %d\n", i, toChars(), em->semanticRun);
                    Expression *e = em->value;
                    e = e->implicitCastTo(sc, ed->memtype);
                    e = e->ctfeInterpret();
                    e = e->castTo(sc, ed->type);
                    if (e->op == TOKerror)
                        ed->errors = true;
                    em->value = e;
                }
                if (ed->errors)
                {
                    ed->memtype = Type::terror;
                    goto Lerrors;
                }
            }
        }

        if (ed->memtype && !type)
        {
            e = e->implicitCastTo(sc, ed->memtype);
            e = e->ctfeInterpret();

            // save origValue for better json output
            origValue = e;

            if (!ed->isAnonymous())
                e = e->castTo(sc, ed->type);
        }
        else if (type)
        {
            e = e->implicitCastTo(sc, type);
            e = e->ctfeInterpret();
            assert(ed->isAnonymous());

            // save origValue for better json output
            origValue = e;
        }
//.........这里部分代码省略.........

void EnumDeclaration::semantic(Scope *sc)
{
    uinteger_t number;
    Type *t;
    Scope *sce;

    //printf("EnumDeclaration::semantic(sd = %p, '%s')\n", sc->scopesym, sc->scopesym->toChars());
    if (!memtype)
        memtype = Type::tint32;

    if (symtab)                 // if already done
    {   if (isdone || !scope)
            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;

    if (sc->stc & STCdeprecated)
        isdeprecated = 1;

    parent = sc->scopesym;
    memtype = memtype->semantic(loc, sc);

    /* Check to see if memtype is forward referenced
     */
    if (memtype->ty == Tenum)
    {   EnumDeclaration *sym = (EnumDeclaration *)memtype->toDsymbol(sc);
        if (!sym->memtype)
        {
            error("base enum %s is forward referenced", sym->toChars());
            memtype = Type::tint32;
        }
    }

    if (!memtype->isintegral())
    {   error("base type must be of integral type, not %s", memtype->toChars());
        memtype = Type::tint32;
    }

    isdone = 1;
    Module::dprogress++;

    t = isAnonymous() ? memtype : type;
    symtab = new DsymbolTable();
    sce = sc->push(this);
    sce->parent = this;
    number = 0;
    if (!members)               // enum ident;
        return;
    if (members->dim == 0)
        error("enum %s must have at least one member", toChars());
    int first = 1;
    for (size_t i = 0; i < members->dim; i++)
    {
        EnumMember *em = ((Dsymbol *)members->data[i])->isEnumMember();
        Expression *e;

        if (!em)
            /* The e->semantic(sce) can insert other symbols, such as
             * template instances and function literals.
             */
            continue;

        //printf("Enum member '%s'\n",em->toChars());
        e = em->value;
        if (e)
        {
            assert(e->dyncast() == DYNCAST_EXPRESSION);
            e = e->semantic(sce);
            e = e->optimize(WANTvalue);
            // Need to copy it because we're going to change the type
            e = e->copy();
            e = e->implicitCastTo(sc, memtype);
            e = e->optimize(WANTvalue);
            number = e->toInteger();
            e->type = t;
        }
        else
        {   // Default is the previous number plus 1

            // Check for overflow
            if (!first)
            {
                switch (t->toBasetype()->ty)
                {
                    case Tbool:
                        if (number == 2)        goto Loverflow;
                        break;

                    case Tint8:
                        if (number == 128) goto Loverflow;
//.........这里部分代码省略.........