view dmd2/struct.c @ 1479:4f7d50c744ed

Rewrite `StructLiteralExp::toElem` to store individual fields instead of generating a constant to fill the entire struct with a single `store`. This is much more efficient at compile time (fixing #320) and vastly reduces the size of the emitted code. Since LLVM no longer needs to keep the data for all fields in "registers" until the store happens, it should also be more efficient at run time in cases where the fields aren't assigned with constants. There's also some code clean-up by removing duplicated logic.
author Frits van Bommel <fvbommel wxs.nl>
date Sat, 06 Jun 2009 20:16:13 +0200
parents 638d16625da2
children f62347c22d81
line wrap: on
line source


// Compiler implementation of the D programming language
// Copyright (c) 1999-2009 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 "aggregate.h"
#include "scope.h"
#include "mtype.h"
#include "declaration.h"
#include "module.h"
#include "id.h"
#include "statement.h"
#include "template.h"

/********************************* AggregateDeclaration ****************************/

AggregateDeclaration::AggregateDeclaration(Loc loc, Identifier *id)
    : ScopeDsymbol(id)
{
    this->loc = loc;

    storage_class = 0;
    protection = PROTpublic;
    type = NULL;
    handle = NULL;
    structsize = 0;		// size of struct
    alignsize = 0;		// size of struct for alignment purposes
    structalign = 0;		// struct member alignment in effect
    hasUnions = 0;
    sizeok = 0;			// size not determined yet
    isdeprecated = 0;
    inv = NULL;
    aggNew = NULL;
    aggDelete = NULL;

#if IN_DMD
    stag = NULL;
    sinit = NULL;
#endif
    scope = NULL;
    isnested = 0;
    vthis = NULL;

#if DMDV2
    ctor = NULL;
    defaultCtor = NULL;
    aliasthis = NULL;
#endif
    dtor = NULL;
}

enum PROT AggregateDeclaration::prot()
{
    return protection;
}

void AggregateDeclaration::semantic2(Scope *sc)
{
    //printf("AggregateDeclaration::semantic2(%s)\n", toChars());
    if (scope)
    {	error("has forward references");
	return;
    }
    if (members)
    {
	sc = sc->push(this);
	for (size_t i = 0; i < members->dim; i++)
	{
	    Dsymbol *s = (Dsymbol *)members->data[i];
	    s->semantic2(sc);
	}
	sc->pop();
    }
}

void AggregateDeclaration::semantic3(Scope *sc)
{   int i;

    //printf("AggregateDeclaration::semantic3(%s)\n", toChars());
    if (members)
    {
	sc = sc->push(this);
	for (i = 0; i < members->dim; i++)
	{
	    Dsymbol *s = (Dsymbol *)members->data[i];
	    s->semantic3(sc);
	}
	sc->pop();
    }
}

void AggregateDeclaration::inlineScan()
{   int i;

    //printf("AggregateDeclaration::inlineScan(%s)\n", toChars());
    if (members)
    {
	for (i = 0; i < members->dim; i++)
	{
	    Dsymbol *s = (Dsymbol *)members->data[i];
	    //printf("inline scan aggregate symbol '%s'\n", s->toChars());
	    s->inlineScan();
	}
    }
}

unsigned AggregateDeclaration::size(Loc loc)
{
    //printf("AggregateDeclaration::size() = %d\n", structsize);
    if (!members)
	error(loc, "unknown size");
    if (sizeok != 1)
    {	error(loc, "no size yet for forward reference");
	//*(char*)0=0;
    }
    return structsize;
}

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

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

/****************************
 * Do byte or word alignment as necessary.
 * Align sizes of 0, as we may not know array sizes yet.
 */

void AggregateDeclaration::alignmember(
	unsigned salign,	// struct alignment that is in effect
	unsigned size,		// alignment requirement of field
	unsigned *poffset)
{
    //printf("salign = %d, size = %d, offset = %d\n",salign,size,offset);
    if (salign > 1)
    {
	assert(size != 3);
	int sa = size;
	if (sa == 0 || salign < sa)
	    sa = salign;
	*poffset = (*poffset + sa - 1) & ~(sa - 1);
    }
    //printf("result = %d\n",offset);
}


void AggregateDeclaration::addField(Scope *sc, VarDeclaration *v)
{
    unsigned memsize;		// size of member
    unsigned memalignsize;	// size of member for alignment purposes
    unsigned xalign;		// alignment boundaries

    //printf("AggregateDeclaration::addField('%s') %s\n", v->toChars(), toChars());
    assert(!(v->storage_class & (STCstatic | STCextern | STCparameter | STCtls)));

    // Check for forward referenced types which will fail the size() call
    Type *t = v->type->toBasetype();
    if (v->storage_class & STCref)
    {	// References are the size of a pointer
	t = Type::tvoidptr;
    }
    if (t->ty == Tstruct /*&& isStructDeclaration()*/)
    {	TypeStruct *ts = (TypeStruct *)t;
#if DMDV2
	if (ts->sym == this)
	{
	    error("cannot have field %s with same struct type", v->toChars());
	}
#endif

	if (ts->sym->sizeok != 1)
	{
	    sizeok = 2;		// cannot finish; flag as forward referenced
	    return;
	}
    }
    if (t->ty == Tident)
    {
	sizeok = 2;		// cannot finish; flag as forward referenced
	return;
    }

    memsize = t->size(loc);
    memalignsize = t->alignsize();
    xalign = t->memalign(sc->structalign);
    alignmember(xalign, memalignsize, &sc->offset);
    v->offset = sc->offset;
    sc->offset += memsize;
    if (sc->offset > structsize)
	structsize = sc->offset;
    if (sc->structalign < memalignsize)
	memalignsize = sc->structalign;
    if (alignsize < memalignsize)
	alignsize = memalignsize;
    //printf("\talignsize = %d\n", alignsize);

    v->storage_class |= STCfield;
    //printf(" addField '%s' to '%s' at offset %d, size = %d\n", v->toChars(), toChars(), v->offset, memsize);
    fields.push(v);
}


/****************************************
 * Returns !=0 if there's an extra member which is the 'this'
 * pointer to the enclosing context (enclosing aggregate or function)
 */

int AggregateDeclaration::isNested()
{
    return isnested;
}


/********************************* StructDeclaration ****************************/

StructDeclaration::StructDeclaration(Loc loc, Identifier *id)
    : AggregateDeclaration(loc, id)
{
    zeroInit = 0;	// assume false until we do semantic processing
#if DMDV2
    hasIdentityAssign = 0;
    cpctor = NULL;
    postblit = NULL;
#endif

    // For forward references
    type = new TypeStruct(this);
}

Dsymbol *StructDeclaration::syntaxCopy(Dsymbol *s)
{
    StructDeclaration *sd;

    if (s)
	sd = (StructDeclaration *)s;
    else
	sd = new StructDeclaration(loc, ident);
    ScopeDsymbol::syntaxCopy(sd);
    return sd;
}

void StructDeclaration::semantic(Scope *sc)
{   int i;
    Scope *sc2;

    //printf("+StructDeclaration::semantic(this=%p, '%s')\n", this, toChars());

    //static int count; if (++count == 20) *(char*)0=0;

    assert(type);
    if (!members)			// if forward reference
	return;

    if (symtab)
    {   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;
    }

    parent = sc->parent;
#if STRUCTTHISREF
    handle = type;
#else
    handle = type->pointerTo();
#endif
    structalign = sc->structalign;
    protection = sc->protection;
    storage_class |= sc->stc;
    if (sc->stc & STCdeprecated)
	isdeprecated = 1;
    assert(!isAnonymous());
    if (sc->stc & STCabstract)
	error("structs, unions cannot be abstract");
#if DMDV2
    if (storage_class & STCimmutable)
        type = type->invariantOf();
    else if (storage_class & STCconst)
        type = type->constOf();
    else if (storage_class & STCshared)
        type = type->sharedOf();
#endif

    if (sizeok == 0)		// if not already done the addMember step
    {
	int hasfunctions = 0;
	for (i = 0; i < members->dim; i++)
	{
	    Dsymbol *s = (Dsymbol *)members->data[i];
	    //printf("adding member '%s' to '%s'\n", s->toChars(), this->toChars());
	    s->addMember(sc, this, 1);
	    if (s->isFuncDeclaration())
		hasfunctions = 1;
	}

	// If nested struct, add in hidden 'this' pointer to outer scope
	if (hasfunctions && !(storage_class & STCstatic))
        {   Dsymbol *s = toParent2();
            if (s)
            {
                AggregateDeclaration *ad = s->isAggregateDeclaration();
                FuncDeclaration *fd = s->isFuncDeclaration();

		TemplateInstance *ti;
                if (ad && (ti = ad->parent->isTemplateInstance()) != NULL && ti->isnested || fd)
                {   isnested = 1;
                    Type *t;
                    if (ad)
                        t = ad->handle;
                    else if (fd)
                    {   AggregateDeclaration *ad = fd->isMember2();
                        if (ad)
                            t = ad->handle;
                        else
			    t = Type::tvoidptr;
                    }
                    else
                        assert(0);
		    if (t->ty == Tstruct)
			t = Type::tvoidptr;	// t should not be a ref type
                    assert(!vthis);
                    vthis = new ThisDeclaration(loc, t);
		    //vthis->storage_class |= STCref;
                    members->push(vthis);
                }
            }
        }
    }

    sizeok = 0;
    sc2 = sc->push(this);
    sc2->stc &= storage_class & STC_TYPECTOR;
    sc2->parent = this;
    if (isUnionDeclaration())
	sc2->inunion = 1;
    sc2->protection = PROTpublic;
    sc2->explicitProtection = 0;

    int members_dim = members->dim;
    for (i = 0; i < members_dim; i++)
    {
	Dsymbol *s = (Dsymbol *)members->data[i];
	s->semantic(sc2);
	if (isUnionDeclaration())
	    sc2->offset = 0;
#if 0
	if (sizeok == 2)
	{   //printf("forward reference\n");
	    break;
	}
#endif
	Type *t;
	if (s->isDeclaration() &&
	    (t = s->isDeclaration()->type) != NULL &&
	    t->toBasetype()->ty == Tstruct)
	{   StructDeclaration *sd = (StructDeclaration *)t->toDsymbol(sc);
	    if (sd->isnested)
		error("inner struct %s cannot be a field", sd->toChars());
	}
    }

    /* The TypeInfo_Struct is expecting an opEquals and opCmp with
     * a parameter that is a pointer to the struct. But if there
     * isn't one, but is an opEquals or opCmp with a value, write
     * another that is a shell around the value:
     *	int opCmp(struct *p) { return opCmp(*p); }
     */

    TypeFunction *tfeqptr;
    {
	Arguments *arguments = new Arguments;
	Argument *arg = new Argument(STCin, handle, Id::p, NULL);

	arguments->push(arg);
	tfeqptr = new TypeFunction(arguments, Type::tint32, 0, LINKd);
	tfeqptr = (TypeFunction *)tfeqptr->semantic(0, sc);
    }

    TypeFunction *tfeq;
    {
	Arguments *arguments = new Arguments;
	Argument *arg = new Argument(STCin, type, NULL, NULL);

	arguments->push(arg);
	tfeq = new TypeFunction(arguments, Type::tint32, 0, LINKd);
	tfeq = (TypeFunction *)tfeq->semantic(0, sc);
    }

    Identifier *id = Id::eq;
    for (int i = 0; i < 2; i++)
    {
	Dsymbol *s = search_function(this, id);
	FuncDeclaration *fdx = s ? s->isFuncDeclaration() : NULL;
	if (fdx)
	{   FuncDeclaration *fd = fdx->overloadExactMatch(tfeqptr, getModule());
	    if (!fd)
	    {	fd = fdx->overloadExactMatch(tfeq, getModule());
		if (fd)
		{   // Create the thunk, fdptr
		    FuncDeclaration *fdptr = new FuncDeclaration(loc, loc, fdx->ident, STCundefined, tfeqptr);
		    Expression *e = new IdentifierExp(loc, Id::p);
		    e = new PtrExp(loc, e);
		    Expressions *args = new Expressions();
		    args->push(e);
		    e = new IdentifierExp(loc, id);
		    e = new CallExp(loc, e, args);
		    fdptr->fbody = new ReturnStatement(loc, e);
		    ScopeDsymbol *s = fdx->parent->isScopeDsymbol();
		    assert(s);
		    s->members->push(fdptr);
		    fdptr->addMember(sc, s, 1);
		    fdptr->semantic(sc2);
		}
	    }
	}

	id = Id::cmp;
    }
#if DMDV2
    dtor = buildDtor(sc2);
    postblit = buildPostBlit(sc2);
    cpctor = buildCpCtor(sc2);
    buildOpAssign(sc2);
#endif

    sc2->pop();

    if (sizeok == 2)
    {	// semantic() failed because of forward references.
	// Unwind what we did, and defer it for later
	fields.setDim(0);
	structsize = 0;
	alignsize = 0;
	structalign = 0;

	scope = scx ? scx : new Scope(*sc);
	scope->setNoFree();
	scope->module->addDeferredSemantic(this);
	//printf("\tdeferring %s\n", toChars());
	return;
    }

    // 0 sized struct's are set to 1 byte
    if (structsize == 0)
    {
	structsize = 1;
	alignsize = 1;
    }

    // Round struct size up to next alignsize boundary.
    // This will ensure that arrays of structs will get their internals
    // aligned properly.
    structsize = (structsize + alignsize - 1) & ~(alignsize - 1);

    sizeok = 1;
    Module::dprogress++;

    //printf("-StructDeclaration::semantic(this=%p, '%s')\n", this, toChars());

    // Determine if struct is all zeros or not
    zeroInit = 1;
    for (i = 0; i < fields.dim; i++)
    {
	Dsymbol *s = (Dsymbol *)fields.data[i];
	VarDeclaration *vd = s->isVarDeclaration();
	if (vd && !vd->isDataseg())
	{
	    if (vd->init)
	    {
		// Should examine init to see if it is really all 0's
		zeroInit = 0;
		break;
	    }
	    else
	    {
		if (!vd->type->isZeroInit(loc))
		{
		    zeroInit = 0;
		    break;
		}
	    }
	}
    }

    /* Look for special member functions.
     */
#if DMDV2
    ctor = search(0, Id::ctor, 0);
#endif
    inv =    (InvariantDeclaration *)search(0, Id::classInvariant, 0);
    aggNew =       (NewDeclaration *)search(0, Id::classNew,       0);
    aggDelete = (DeleteDeclaration *)search(0, Id::classDelete,    0);

    if (sc->func)
    {
	semantic2(sc);
	semantic3(sc);
    }
}

void StructDeclaration::toCBuffer(OutBuffer *buf, HdrGenState *hgs)
{   int i;

    buf->printf("%s ", kind());
    if (!isAnonymous())
	buf->writestring(toChars());
    if (!members)
    {
	buf->writeByte(';');
	buf->writenl();
	return;
    }
    buf->writenl();
    buf->writeByte('{');
    buf->writenl();
    for (i = 0; i < members->dim; i++)
    {
	Dsymbol *s = (Dsymbol *)members->data[i];

	buf->writestring("    ");
	s->toCBuffer(buf, hgs);
    }
    buf->writeByte('}');
    buf->writenl();
}


const char *StructDeclaration::kind()
{
    return "struct";
}

/********************************* UnionDeclaration ****************************/

UnionDeclaration::UnionDeclaration(Loc loc, Identifier *id)
    : StructDeclaration(loc, id)
{
}

Dsymbol *UnionDeclaration::syntaxCopy(Dsymbol *s)
{
    UnionDeclaration *ud;

    if (s)
	ud = (UnionDeclaration *)s;
    else
	ud = new UnionDeclaration(loc, ident);
    StructDeclaration::syntaxCopy(ud);
    return ud;
}


const char *UnionDeclaration::kind()
{
    return "union";
}