root/branches/dmdfe-2.0/enum.c

// Copyright (c) 1999-2008 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 "id.h"
#include "expression.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 = NULL;
    minval = NULL;
    defaultval = NULL;
    sinit = NULL;
    scope = NULL;
    isdeprecated = 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::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);
        e = e->optimize(WANTvalue | WANTinterpret);
        if (!isAnonymous())
            e = e->castTo(sce, type);
        t = memtype;
        }
        else if (em->type)
        {
        e = e->implicitCastTo(sce, em->type);
        e = e->optimize(WANTvalue | WANTinterpret);
        assert(isAnonymous());
        t = e->type;
        }
        else
        t = e->type;
    }
    else if (first)
    {
        if (memtype)
        t = memtype;
        else if (em->type)
        t = em->type;
        else
        t = Type::tint32;
        e = new IntegerExp(em->loc, 0, Type::tint32);
        e = e->implicitCastTo(sce, t);
        e = e->optimize(WANTvalue | WANTinterpret);
        if (!isAnonymous())
        e = e->castTo(sce, type);
    }
    else
    {
        // Set value to (elast + 1).
        // But first check that (elast != t.max)
        assert(elast);
        e = new EqualExp(TOKequal, em->loc, elast, t->getProperty(0, Id::max));
        e = e->semantic(sce);
        e = e->optimize(WANTvalue | WANTinterpret);
        if (e->toInteger())
        error("overflow of enum value %s", elast->toChars());

        // Now set e to (elast + 1)
        e = new AddExp(em->loc, elast, new IntegerExp(em->loc, 1, Type::tint32));
        e = e->semantic(sce);
        e = e->castTo(sce, elast->type);
        e = e->optimize(WANTvalue | WANTinterpret);
    }
    elast = e;
    em->value = e;

    // Add to symbol table only after evaluating 'value'
    if (isAnonymous())
    {
        /* Anonymous enum members get added to enclosing scope.
         */
        for (Scope *scx = sce; scx; scx = scx->enclosing)
        {
        if (scx->scopesym)
        {
            if (!scx->scopesym->symtab)
            scx->scopesym->symtab = new DsymbolTable();
            em->addMember(sce, scx->scopesym, 1);
            break;
        }
        }
    }
    else
        em->addMember(sc, this, 1);

    /* Compute .min, .max and .default values.
     * If enum doesn't have a name, we can never identify the enum type,
     * so there is no purpose for a .min, .max or .default
     */
    if (!isAnonymous())
    {
        if (first)
        {   defaultval = e;
        minval = e;
        maxval = e;
        }
        else
        {   Expression *ec;

        /* In order to work successfully with UDTs,
         * build expressions to do the comparisons,
         * and let the semantic analyzer and constant
         * folder give us the result.
         */

        // Compute if(e < minval)
        ec = new CmpExp(TOKlt, em->loc, e, minval);
        ec = ec->semantic(sce);
        ec = ec->optimize(WANTvalue | WANTinterpret);
        if (ec->toInteger())
            minval = e;

        ec = new CmpExp(TOKgt, em->loc, e, maxval);
        ec = ec->semantic(sce);
        ec = ec->optimize(WANTvalue | WANTinterpret);
        if (ec->toInteger())
            maxval = e;
        }
    }
    first = 0;
    }
    //printf("defaultval = %lld\n", defaultval);

    //if (defaultval) printf("defaultval: %s %s\n", defaultval->toChars(), defaultval->type->toChars());
    if (sc != sce)
    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)
{   int i;

    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 (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;
}

Dsymbol *EnumDeclaration::search(Loc loc, Identifier *ident, int flags)
{
    //printf("%s.EnumDeclaration::search('%s')\n", toChars(), ident->toChars());
    if (scope)
    // Try one last time to resolve this enum
        semantic(scope);

    if (!members || !symtab || scope)
    {   error("is forward referenced when looking for '%s'", ident->toChars());
        //*(char*)0=0;
        return NULL;
    }

    Dsymbol *s = ScopeDsymbol::search(loc, ident, flags);
    return s;
}

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

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

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

    Type *t = NULL;
    if (type)
    t = type->syntaxCopy();

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

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

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