view dmd2/init.c @ 1047:6bb04dbee21f

Some calling convention work for x86-64: - Implement x86-64 extern(C), hopefully correctly. - Tried to be a bit smarter about extern(D) while I was there. Interestingly, this code seems to be generating more efficient code than gcc and llvm-gcc in some edge cases, like returning a `{ [7 x i8] }` loaded from a stack slot from an extern(C) function. (gcc generates 7 1-byte loads, while this code generates a 4-byte, a 2-byte and a 1-byte load) I also added some changes to make sure structs being returned from functions or passed in as parameters are stored in memory where the rest of the backend seems to expect them to be. These should be removed when support for first-class aggregates improves.
author Frits van Bommel <fvbommel wxs.nl>
date Fri, 06 Mar 2009 16:00:47 +0100
parents 356e65836fb5
children 638d16625da2
line wrap: on
line source


// Compiler implementation of the D programming language
// Copyright (c) 1999-2007 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 "mars.h"
#include "init.h"
#include "expression.h"
#include "statement.h"
#include "identifier.h"
#include "declaration.h"
#include "aggregate.h"
#include "scope.h"
#include "mtype.h"
#include "hdrgen.h"

/********************************** Initializer *******************************/

Initializer::Initializer(Loc loc)
{
    this->loc = loc;
}

Initializer *Initializer::syntaxCopy()
{
    return this;
}

Initializer *Initializer::semantic(Scope *sc, Type *t)
{
    return this;
}

Type *Initializer::inferType(Scope *sc)
{
    error(loc, "cannot infer type from initializer");
    return Type::terror;
}

Initializers *Initializer::arraySyntaxCopy(Initializers *ai)
{   Initializers *a = NULL;

    if (ai)
    {
	a = new Initializers();
	a->setDim(ai->dim);
	for (int i = 0; i < a->dim; i++)
	{   Initializer *e = (Initializer *)ai->data[i];

	    e = e->syntaxCopy();
	    a->data[i] = e;
	}
    }
    return a;
}

char *Initializer::toChars()
{   OutBuffer *buf;
    HdrGenState hgs;

    memset(&hgs, 0, sizeof(hgs));
    buf = new OutBuffer();
    toCBuffer(buf, &hgs);
    return buf->toChars();
}

/********************************** VoidInitializer ***************************/

VoidInitializer::VoidInitializer(Loc loc)
    : Initializer(loc)
{
    type = NULL;
}


Initializer *VoidInitializer::syntaxCopy()
{
    return new VoidInitializer(loc);
}


Initializer *VoidInitializer::semantic(Scope *sc, Type *t)
{
    //printf("VoidInitializer::semantic(t = %p)\n", t);
    type = t;
    return this;
}


Expression *VoidInitializer::toExpression()
{
    error(loc, "void initializer has no value");
    return new IntegerExp(0);
}


void VoidInitializer::toCBuffer(OutBuffer *buf, HdrGenState *hgs)
{
    buf->writestring("void");
}


/********************************** StructInitializer *************************/

StructInitializer::StructInitializer(Loc loc)
    : Initializer(loc)
{
    ad = NULL;
}

Initializer *StructInitializer::syntaxCopy()
{
    StructInitializer *ai = new StructInitializer(loc);

    assert(field.dim == value.dim);
    ai->field.setDim(field.dim);
    ai->value.setDim(value.dim);
    for (int i = 0; i < field.dim; i++)
    {    
	ai->field.data[i] = field.data[i];

	Initializer *init = (Initializer *)value.data[i];
	init = init->syntaxCopy();
	ai->value.data[i] = init;
    }
    return ai;
}

void StructInitializer::addInit(Identifier *field, Initializer *value)
{
    //printf("StructInitializer::addInit(field = %p, value = %p)\n", field, value);
    this->field.push(field);
    this->value.push(value);
}

Initializer *StructInitializer::semantic(Scope *sc, Type *t)
{
    TypeStruct *ts;
    int errors = 0;

    //printf("StructInitializer::semantic(t = %s) %s\n", t->toChars(), toChars());
    vars.setDim(field.dim);
    t = t->toBasetype();
    if (t->ty == Tstruct)
    {	unsigned i;
	unsigned fieldi = 0;

	ts = (TypeStruct *)t;
	ad = ts->sym;
	for (i = 0; i < field.dim; i++)
	{
	    Identifier *id = (Identifier *)field.data[i];
	    Initializer *val = (Initializer *)value.data[i];
	    Dsymbol *s;
	    VarDeclaration *v;

	    if (id == NULL)
	    {
		if (fieldi >= ad->fields.dim)
		{   error(loc, "too many initializers for %s", ad->toChars());
		    field.remove(i);
		    i--;
		    continue;
		}
		else
		{
		    s = (Dsymbol *)ad->fields.data[fieldi];
		}
	    }
	    else
	    {
		//s = ad->symtab->lookup(id);
		s = ad->search(loc, id, 0);
		if (!s)
		{
		    error(loc, "'%s' is not a member of '%s'", id->toChars(), t->toChars());
		    continue;
		}

		// Find out which field index it is
		for (fieldi = 0; 1; fieldi++)
		{
		    if (fieldi >= ad->fields.dim)
		    {
			s->error("is not a per-instance initializable field");
			break;
		    }
		    if (s == (Dsymbol *)ad->fields.data[fieldi])
			break;
		}
	    }
	    if (s && (v = s->isVarDeclaration()) != NULL)
	    {
		val = val->semantic(sc, v->type);
		value.data[i] = (void *)val;
		vars.data[i] = (void *)v;
	    }
	    else
	    {	error(loc, "%s is not a field of %s", id ? id->toChars() : s->toChars(), ad->toChars());
		errors = 1;
	    }
	    fieldi++;
	}
    }
    else if (t->ty == Tdelegate && value.dim == 0)
    {	/* Rewrite as empty delegate literal { }
	 */
	Arguments *arguments = new Arguments;
	Type *tf = new TypeFunction(arguments, NULL, 0, LINKd);
	FuncLiteralDeclaration *fd = new FuncLiteralDeclaration(loc, 0, tf, TOKdelegate, NULL);
	fd->fbody = new CompoundStatement(loc, new Statements());
	fd->endloc = loc;
	Expression *e = new FuncExp(loc, fd);
	ExpInitializer *ie = new ExpInitializer(loc, e);
	return ie->semantic(sc, t);
    }
    else
    {
	error(loc, "a struct is not a valid initializer for a %s", t->toChars());
	errors = 1;
    }
    if (errors)
    {
	field.setDim(0);
	value.setDim(0);
	vars.setDim(0);
    }
    return this;
}


/***************************************
 * This works by transforming a struct initializer into
 * a struct literal. In the future, the two should be the
 * same thing.
 */
Expression *StructInitializer::toExpression()
{   Expression *e;

    //printf("StructInitializer::toExpression() %s\n", toChars());
    if (!ad)				// if fwd referenced
    {
	return NULL;
    }
    StructDeclaration *sd = ad->isStructDeclaration();
    if (!sd)
	return NULL;
    Expressions *elements = new Expressions();
    for (size_t i = 0; i < value.dim; i++)
    {
	if (field.data[i])
	    goto Lno;
	Initializer *iz = (Initializer *)value.data[i];
	if (!iz)
	    goto Lno;
	Expression *ex = iz->toExpression();
	if (!ex)
	    goto Lno;
	elements->push(ex);
    }
    e = new StructLiteralExp(loc, sd, elements);
    e->type = sd->type;
    return e;

Lno:
    delete elements;
    //error(loc, "struct initializers as expressions are not allowed");
    return NULL;
}


void StructInitializer::toCBuffer(OutBuffer *buf, HdrGenState *hgs)
{
    //printf("StructInitializer::toCBuffer()\n");
    buf->writebyte('{');
    for (int i = 0; i < field.dim; i++)
    {
        if (i > 0)
	    buf->writebyte(',');
        Identifier *id = (Identifier *)field.data[i];
        if (id)
        {
            buf->writestring(id->toChars());
            buf->writebyte(':');
        }
        Initializer *iz = (Initializer *)value.data[i];
        if (iz)
            iz->toCBuffer(buf, hgs);
    }
    buf->writebyte('}');
}

/********************************** ArrayInitializer ************************************/

ArrayInitializer::ArrayInitializer(Loc loc)
    : Initializer(loc)
{
    dim = 0;
    type = NULL;
    sem = 0;
}

Initializer *ArrayInitializer::syntaxCopy()
{
    //printf("ArrayInitializer::syntaxCopy()\n");

    ArrayInitializer *ai = new ArrayInitializer(loc);

    assert(index.dim == value.dim);
    ai->index.setDim(index.dim);
    ai->value.setDim(value.dim);
    for (int i = 0; i < ai->value.dim; i++)
    {	Expression *e = (Expression *)index.data[i];
	if (e)
	    e = e->syntaxCopy();
	ai->index.data[i] = e;

	Initializer *init = (Initializer *)value.data[i];
	init = init->syntaxCopy();
	ai->value.data[i] = init;
    }
    return ai;
}

void ArrayInitializer::addInit(Expression *index, Initializer *value)
{
    this->index.push(index);
    this->value.push(value);
    dim = 0;
    type = NULL;
}

Initializer *ArrayInitializer::semantic(Scope *sc, Type *t)
{   unsigned i;
    unsigned length;

    //printf("ArrayInitializer::semantic(%s)\n", t->toChars());
    if (sem)				// if semantic() already run
	return this;
    sem = 1;
    type = t;
    t = t->toBasetype();
    switch (t->ty)
    {
	case Tpointer:
	case Tsarray:
	case Tarray:
	    break;

	default:
	    error(loc, "cannot use array to initialize %s", type->toChars());
	    return this;
    }

    length = 0;
    for (i = 0; i < index.dim; i++)
    {	Expression *idx;
	Initializer *val;

	idx = (Expression *)index.data[i];
	if (idx)
	{   idx = idx->semantic(sc);
	    idx = idx->optimize(WANTvalue | WANTinterpret);
	    index.data[i] = (void *)idx;
	    length = idx->toInteger();
	}

	val = (Initializer *)value.data[i];
	val = val->semantic(sc, t->nextOf());
	value.data[i] = (void *)val;
	length++;
	if (length == 0)
	    error(loc, "array dimension overflow");
	if (length > dim)
	    dim = length;
    }
    unsigned long amax = 0x80000000;
    if ((unsigned long) dim * t->nextOf()->size() >= amax)
	error(loc, "array dimension %u exceeds max of %ju", dim, amax / t->nextOf()->size());
    return this;
}

/********************************
 * If possible, convert array initializer to array literal.
 */

Expression *ArrayInitializer::toExpression()
{   Expressions *elements;
    Expression *e;

    //printf("ArrayInitializer::toExpression()\n");
    //static int i; if (++i == 2) halt();
    elements = new Expressions();
    for (size_t i = 0; i < value.dim; i++)
    {
	if (index.data[i])
	    goto Lno;
	Initializer *iz = (Initializer *)value.data[i];
	if (!iz)
	    goto Lno;
	Expression *ex = iz->toExpression();
	if (!ex)
	    goto Lno;
	elements->push(ex);
    }
    e = new ArrayLiteralExp(loc, elements);
    e->type = type;
    return e;

Lno:
    delete elements;
    error(loc, "array initializers as expressions are not allowed");
    return NULL;
}


/********************************
 * If possible, convert array initializer to associative array initializer.
 */

Initializer *ArrayInitializer::toAssocArrayInitializer()
{   Expressions *keys;
    Expressions *values;
    Expression *e;

    //printf("ArrayInitializer::toAssocArrayInitializer()\n");
    //static int i; if (++i == 2) halt();
    keys = new Expressions();
    keys->setDim(value.dim);
    values = new Expressions();
    values->setDim(value.dim);

    for (size_t i = 0; i < value.dim; i++)
    {
	e = (Expression *)index.data[i];
	if (!e)
	    goto Lno;
	keys->data[i] = (void *)e;

	Initializer *iz = (Initializer *)value.data[i];
	if (!iz)
	    goto Lno;
	e = iz->toExpression();
	if (!e)
	    goto Lno;
	values->data[i] = (void *)e;
    }
    e = new AssocArrayLiteralExp(loc, keys, values);
    return new ExpInitializer(loc, e);

Lno:
    delete keys;
    delete values;
    error(loc, "not an associative array initializer");
    return this;
}


Type *ArrayInitializer::inferType(Scope *sc)
{
    for (size_t i = 0; i < value.dim; i++)
    {
	if (index.data[i])
	    goto Lno;
    }
    if (value.dim)
    {
	Initializer *iz = (Initializer *)value.data[0];
	if (iz)
	{   Type *t = iz->inferType(sc);
	    t = new TypeSArray(t, new IntegerExp(value.dim));
	    t = t->semantic(loc, sc);
	    return t;
	}
    }

Lno:
    error(loc, "cannot infer type from this array initializer");
    return Type::terror;
}


void ArrayInitializer::toCBuffer(OutBuffer *buf, HdrGenState *hgs)
{
    buf->writebyte('[');
    for (int i = 0; i < index.dim; i++)
    {
        if (i > 0)
	    buf->writebyte(',');
        Expression *ex = (Expression *)index.data[i];
        if (ex)
        {
            ex->toCBuffer(buf, hgs);
            buf->writebyte(':');
        }
        Initializer *iz = (Initializer *)value.data[i];
        if (iz)
            iz->toCBuffer(buf, hgs);
    }
    buf->writebyte(']');
}


/********************************** ExpInitializer ************************************/

ExpInitializer::ExpInitializer(Loc loc, Expression *exp)
    : Initializer(loc)
{
    this->exp = exp;
}

Initializer *ExpInitializer::syntaxCopy()
{
    return new ExpInitializer(loc, exp->syntaxCopy());
}

Initializer *ExpInitializer::semantic(Scope *sc, Type *t)
{
    //printf("ExpInitializer::semantic(%s), type = %s\n", exp->toChars(), t->toChars());
    exp = exp->semantic(sc);
    exp = resolveProperties(sc, exp);
    exp = exp->optimize(WANTvalue | WANTinterpret);
    Type *tb = t->toBasetype();

    /* Look for case of initializing a static array with a too-short
     * string literal, such as:
     *	char[5] foo = "abc";
     * Allow this by doing an explicit cast, which will lengthen the string
     * literal.
     */
    if (exp->op == TOKstring && tb->ty == Tsarray && exp->type->ty == Tsarray)
    {	StringExp *se = (StringExp *)exp;

	if (!se->committed && se->type->ty == Tsarray &&
	    ((TypeSArray *)se->type)->dim->toInteger() <
	    ((TypeSArray *)t)->dim->toInteger())
	{
	    exp = se->castTo(sc, t);
	    goto L1;
	}
    }

    // Look for the case of statically initializing an array
    // with a single member.
    if (tb->ty == Tsarray &&
	!tb->nextOf()->equals(exp->type->toBasetype()->nextOf()) &&
	exp->implicitConvTo(tb->nextOf())
       )
    {
	t = tb->nextOf();
    }

    exp = exp->implicitCastTo(sc, t);
L1:
    exp = exp->optimize(WANTvalue | WANTinterpret);
    //printf("-ExpInitializer::semantic(): "); exp->print();
    return this;
}

Type *ExpInitializer::inferType(Scope *sc)
{
    //printf("ExpInitializer::inferType() %s\n", toChars());
    exp = exp->semantic(sc);
    exp = resolveProperties(sc, exp);

    // Give error for overloaded function addresses
    if (exp->op == TOKsymoff)
    {   SymOffExp *se = (SymOffExp *)exp;
	if (se->hasOverloads && !se->var->isFuncDeclaration()->isUnique())
	    exp->error("cannot infer type from overloaded function symbol %s", exp->toChars());
    }

    Type *t = exp->type;
    return t;
    //return t->ty == Tsarray ? t : t->toHeadMutable();
}

Expression *ExpInitializer::toExpression()
{
    return exp;
}


void ExpInitializer::toCBuffer(OutBuffer *buf, HdrGenState *hgs)
{
    exp->toCBuffer(buf, hgs);
}