enum.c

// Copyright (c) 1999-2011 by Digital Mars
// All Rights Reserved
// written by Walter Bright
// http://www.digitalmars.com
// License for redistribution is by either the Artistic License
// in artistic.txt, or the GNU General Public License in gnu.txt.
// See the included readme.txt for details.

#include <stdio.h>
#include <assert.h>

#include "root.h"
#include "enum.h"
#include "mtype.h"
#include "scope.h"
#include "module.h"
#include "declaration.h"

/********************************* EnumDeclaration ****************************/

EnumDeclaration::EnumDeclaration(Loc loc, Identifier *id, Type *memtype)
    : ScopeDsymbol(id)
{
    this->loc = loc;
    type = new TypeEnum(this);
    this->memtype = memtype;
    maxval = 0;
    minval = 0;
    defaultval = 0;
#if IN_DMD
    sinit = NULL;
#endif
    isdeprecated = 0;
    isdone = 0;
}

Dsymbol *EnumDeclaration::syntaxCopy(Dsymbol *s)
{
    Type *t = NULL;
    if (memtype)
        t = memtype->syntaxCopy();

    EnumDeclaration *ed;
    if (s)
    {   ed = (EnumDeclaration *)s;
        ed->memtype = t;
    }
    else
        ed = new EnumDeclaration(loc, ident, t);
    ScopeDsymbol::syntaxCopy(ed);
    return ed;
}

void EnumDeclaration::semantic0(Scope *sc)
{
    /* This function is a hack to get around a significant problem.
     * The members of anonymous enums, like:
     *  enum { A, B, C }
     * don't get installed into the symbol table until after they are
     * semantically analyzed, yet they're supposed to go into the enclosing
     * scope's table. Hence, when forward referenced, they come out as
     * 'undefined'. The real fix is to add them in at addSymbol() time.
     * But to get code to compile, we'll just do this quick hack at the moment
     * to compile it if it doesn't depend on anything else.
     */

    if (isdone || !scope)
        return;
    if (!isAnonymous() || memtype)
        return;
    for (size_t i = 0; i < members->dim; i++)
    {
        EnumMember *em = ((Dsymbol *)members->data[i])->isEnumMember();
        if (em && em->value)
            return;
    }

    // Can do it
    semantic(sc);
}

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;
                        break;

                    case Tchar:
                    case Tuns8:
                        if (number == 256) goto Loverflow;
                        break;

                    case Tint16:
                        if (number == 0x8000) goto Loverflow;
                        break;

                    case Twchar:
                    case Tuns16:
                        if (number == 0x10000) goto Loverflow;
                        break;

                    case Tint32:
                        if (number == 0x80000000) goto Loverflow;
                        break;

                    case Tdchar:
                    case Tuns32:
                        if (number == 0x100000000LL) goto Loverflow;
                        break;

                    case Tint64:
                        if (number == 0x8000000000000000LL) goto Loverflow;
                        break;

                    case Tuns64:
                        if (number == 0) goto Loverflow;
                        break;

                    Loverflow:
                        error("overflow of enum value");
                        break;

                    default:
                        assert(0);
                }
            }
            e = new IntegerExp(em->loc, number, t);
        }
        em->value = e;

        // Add to symbol table only after evaluating 'value'
        if (isAnonymous())
        {
            //sce->enclosing->insert(em);
            for (Scope *sct = sce->enclosing; sct; sct = sct->enclosing)
            {
                if (sct->scopesym)
                {
                    if (!sct->scopesym->symtab)
                        sct->scopesym->symtab = new DsymbolTable();
                    em->addMember(sce, sct->scopesym, 1);
                    break;
                }
            }
        }
        else
            em->addMember(sc, this, 1);

        if (first)
        {   first = 0;
            defaultval = number;
            minval = number;
            maxval = number;
        }
        else if (memtype->isunsigned())
        {
            if (number < minval)
                minval = number;
            if (number > maxval)
                maxval = number;
        }
        else
        {
            if ((sinteger_t)number < (sinteger_t)minval)
                minval = number;
            if ((sinteger_t)number > (sinteger_t)maxval)
                maxval = number;
        }

        number++;
    }
    //printf("defaultval = %lld\n", defaultval);

    sce->pop();
    //members->print();
}

int EnumDeclaration::oneMember(Dsymbol **ps)
{
    if (isAnonymous())
        return Dsymbol::oneMembers(members, ps);
    return Dsymbol::oneMember(ps);
}

void EnumDeclaration::toCBuffer(OutBuffer *buf, HdrGenState *hgs)
{
    buf->writestring("enum ");
    if (ident)
    {   buf->writestring(ident->toChars());
        buf->writeByte(' ');
    }
    if (memtype)
    {
        buf->writestring(": ");
        memtype->toCBuffer(buf, NULL, hgs);
    }
    if (!members)
    {
        buf->writeByte(';');
        buf->writenl();
        return;
    }
    buf->writenl();
    buf->writeByte('{');
    buf->writenl();
    for (size_t i = 0; i < members->dim; i++)
    {
        EnumMember *em = ((Dsymbol *)members->data[i])->isEnumMember();
        if (!em)
            continue;
        //buf->writestring("    ");
        em->toCBuffer(buf, hgs);
        buf->writeByte(',');
        buf->writenl();
    }
    buf->writeByte('}');
    buf->writenl();
}

Type *EnumDeclaration::getType()
{
    return type;
}

const char *EnumDeclaration::kind()
{
    return "enum";
}

int EnumDeclaration::isDeprecated()
{
    return isdeprecated;
}

/********************************* EnumMember ****************************/

EnumMember::EnumMember(Loc loc, Identifier *id, Expression *value)
    : Dsymbol(id)
{
    this->value = value;
    this->loc = loc;
}

Dsymbol *EnumMember::syntaxCopy(Dsymbol *s)
{
    Expression *e = NULL;
    if (value)
        e = value->syntaxCopy();

    EnumMember *em;
    if (s)
    {   em = (EnumMember *)s;
        em->loc = loc;
        em->value = e;
    }
    else
        em = new EnumMember(loc, ident, e);
    return em;
}

void EnumMember::toCBuffer(OutBuffer *buf, HdrGenState *hgs)
{
    buf->writestring(ident->toChars());
    if (value)
    {
        buf->writestring(" = ");
        value->toCBuffer(buf, hgs);
    }
}

const char *EnumMember::kind()
{
    return "enum member";
}