view dmd/version.c @ 1117:4c20fcc4252b

Fun with parameter attributes: For several of the "synthetic" parameters added to D functions, we can apply noalias and nocapture. They are sret parameters, 'nest' pointers passed to nested functions, and _argptr: Nocapture: - Sret and nest are nocapture because they don't represent D-level variables, and thus the callee can't (validly) obtain a pointer to them, let alone keep it around after it returns. - _argptr is nocapture because although the callee has access to it as a pointer, that pointer is invalidated when it returns. All three are noalias because they're function-local variables - Sret and _argptr are noalias because they're freshly alloca'd memory only used for a single function call that's not allowed to keep an aliasing pointer to it around (since the parameter is nocapture). - 'Nest' is noalias because the callee only ever has access to one such pointer per parent function, and every parent function has a different one. This commit also ensures attributes set on sret, _arguments and _argptr are propagated to calls to such functions. It also adds one exception to the general rule that attributes on function types should propagate to calls: the type of a delegate's function pointer has a 'nest' parameter, but this can either be a true 'nest' (for delegates to nested functions) or a 'this' (for delegates to member functions). Since 'this' is neither noalias nor nocapture, and there's generally no way to tell which one it is, we remove these attributes at the call site if the callee is a delegate.
author Frits van Bommel <fvbommel wxs.nl>
date Sat, 14 Mar 2009 22:15:31 +0100
parents aaade6ded589
children
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// Copyright (c) 1999-2005 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 "identifier.h"
#include "dsymbol.h"
#include "cond.h"
#include "version.h"
#include "module.h"

/* ================================================== */

/* DebugSymbol's happen for statements like:
 *	debug = identifier;
 *	debug = integer;
 */

DebugSymbol::DebugSymbol(Loc loc, Identifier *ident)
    : Dsymbol(ident)
{
    this->loc = loc;
}

DebugSymbol::DebugSymbol(Loc loc, unsigned level)
    : Dsymbol()
{
    this->level = level;
    this->loc = loc;
}

Dsymbol *DebugSymbol::syntaxCopy(Dsymbol *s)
{
    assert(!s);
    DebugSymbol *ds = new DebugSymbol(loc, ident);
    ds->level = level;
    return ds;
}

int DebugSymbol::addMember(Scope *sc, ScopeDsymbol *sd, int memnum)
{
    //printf("DebugSymbol::addMember('%s') %s\n", sd->toChars(), toChars());
    Module *m;

    // Do not add the member to the symbol table,
    // just make sure subsequent debug declarations work.
    m = sd->isModule();
    if (ident)
    {
	if (!m)
	    error("declaration must be at module level");
	else
	{
	    if (findCondition(m->debugidsNot, ident))
		error("defined after use");
	    if (!m->debugids)
		m->debugids = new Array();
	    m->debugids->push(ident->toChars());
	}
    }
    else
    {
	if (!m)
	    error("level declaration must be at module level");
	else
	    m->debuglevel = level;
    }
    return 0;
}

void DebugSymbol::semantic(Scope *sc)
{
    //printf("DebugSymbol::semantic() %s\n", toChars());
}

void DebugSymbol::toCBuffer(OutBuffer *buf, HdrGenState *hgs)
{
    buf->writestring("debug = ");
    if (ident)
	buf->writestring(ident->toChars());
    else
	buf->printf("%u", level);
    buf->writestring(";");
    buf->writenl();
}

const char *DebugSymbol::kind()
{
    return "debug";
}

/* ================================================== */

/* VersionSymbol's happen for statements like:
 *	version = identifier;
 *	version = integer;
 */

VersionSymbol::VersionSymbol(Loc loc, Identifier *ident)
    : Dsymbol(ident)
{
    this->loc = loc;
}

VersionSymbol::VersionSymbol(Loc loc, unsigned level)
    : Dsymbol()
{
    this->level = level;
    this->loc = loc;
}

Dsymbol *VersionSymbol::syntaxCopy(Dsymbol *s)
{
    assert(!s);
    VersionSymbol *ds = new VersionSymbol(loc, ident);
    ds->level = level;
    return ds;
}

int VersionSymbol::addMember(Scope *sc, ScopeDsymbol *sd, int memnum)
{
    //printf("VersionSymbol::addMember('%s') %s\n", sd->toChars(), toChars());
    Module *m;

    // Do not add the member to the symbol table,
    // just make sure subsequent debug declarations work.
    m = sd->isModule();
    if (ident)
    {
	VersionCondition::checkPredefined(loc, ident->toChars());
	if (!m)
	    error("declaration must be at module level");
	else
	{
	    if (findCondition(m->versionidsNot, ident))
		error("defined after use");
	    if (!m->versionids)
		m->versionids = new Array();
	    m->versionids->push(ident->toChars());
	}
    }
    else
    {
	if (!m)
	    error("level declaration must be at module level");
	else
	    m->versionlevel = level;
    }
    return 0;
}

void VersionSymbol::semantic(Scope *sc)
{
}

void VersionSymbol::toCBuffer(OutBuffer *buf, HdrGenState *hgs)
{
    buf->writestring("version = ");
    if (ident)
	buf->writestring(ident->toChars());
    else
	buf->printf("%u", level);
    buf->writestring(";");
    buf->writenl();
}

const char *VersionSymbol::kind()
{
    return "version";
}