view dmd2/lstring.h @ 1168:ab186e535e72

A different fix to #218 and DMD2682 that does not lead to constant folding regressions. Fixes run/const_15, run/c/const_16_B. The price is removing the lvalueness of struct literals. If it turns out too much code depends on this behavior or we don't want to break with DMD, we could keep struct literals as lvalues and instead convert struct literals used as expression initializers into struct initializers.
author Christian Kamm <kamm incasoftware de>
date Sun, 29 Mar 2009 11:43:45 +0200
parents f04dde6e882c
children
line wrap: on
line source


// 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