view dmd2/lstring.h @ 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 f04dde6e882c
children
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// lstring.h
// length-prefixed strings

// Copyright (c) 1999-2002 by Digital Mars
// All Rights Reserved
// written by Walter Bright
// 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.

#ifndef LSTRING_H
#define LSTRING_H 1

#include "dchar.h"

struct Lstring
{
    unsigned length;

    // Disable warning about nonstandard extension
    #pragma warning (disable : 4200)
    dchar string[];

    static Lstring zero;	// 0 length string

    // No constructors because we want to be able to statically
    // initialize Lstring's, and Lstrings are of variable size.

    #if M_UNICODE
    #define LSTRING(p,length) { length, L##p }
    #else
    #define LSTRING(p,length) { length, p }
    #endif

#if __GNUC__
    #define LSTRING_EMPTY() { 0 }
#else
    #define LSTRING_EMPTY() LSTRING("", 0)
#endif

    static Lstring *ctor(const dchar *p) { return ctor(p, Dchar::len(p)); }
    static Lstring *ctor(const dchar *p, unsigned length);
    static unsigned size(unsigned length) { return sizeof(Lstring) + (length + 1) * sizeof(dchar); }
    static Lstring *alloc(unsigned length);
    Lstring *clone();

    unsigned len() { return length; }

    dchar *toDchars() { return string; }

    hash_t hash() { return Dchar::calcHash(string, length); }
    hash_t ihash() { return Dchar::icalcHash(string, length); }

    static int cmp(const Lstring *s1, const Lstring *s2)
    {
	int c = s2->length - s1->length;
	return c ? c : Dchar::memcmp(s1->string, s2->string, s1->length);
    }

    static int icmp(const Lstring *s1, const Lstring *s2)
    {
	int c = s2->length - s1->length;
	return c ? c : Dchar::memicmp(s1->string, s2->string, s1->length);
    }

    Lstring *append(const Lstring *s);
    Lstring *substring(int start, int end);
};

#endif