164 lines
4.8 KiB
C
164 lines
4.8 KiB
C
/*
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Expression Evaluator Library (NS-EEL)
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Copyright (C) 2004-2008 Cockos Incorporated
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Copyright (C) 1999-2003 Nullsoft, Inc.
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nseel-yylex.c
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This software is provided 'as-is', without any express or implied
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warranty. In no event will the authors be held liable for any damages
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arising from the use of this software.
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Permission is granted to anyone to use this software for any purpose,
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including commercial applications, and to alter it and redistribute it
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freely, subject to the following restrictions:
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1. The origin of this software must not be misrepresented; you must not
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claim that you wrote the original software. If you use this software
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in a product, an acknowledgment in the product documentation would be
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appreciated but is not required.
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2. Altered source versions must be plainly marked as such, and must not be
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misrepresented as being the original software.
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3. This notice may not be removed or altered from any source distribution.
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*/
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#include "ns-eel-int.h"
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#define NBPW 16
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#define EOF (-1)
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#define YYERRORVAL 256 /* yacc's value */
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static int llset(compileContext *ctx);
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static int llinp(compileContext *ctx, char **exp);
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static int lexgetc(char **exp)
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{
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char c= **exp;
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if (c) (*exp)++;
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return( c != 0 ? c : -1);
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}
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static int tst__b(register int c, char tab[])
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{
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return (tab[(c >> 3) & 037] & (1 << (c & 07)) );
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}
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int nseel_gettoken(compileContext *ctx, char *lltb, int lltbsiz)
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{
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register char *lp, *tp, *ep;
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tp = lltb;
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ep = tp+lltbsiz-1;
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for (lp = ctx->llbuf; lp < ctx->llend && tp < ep;)
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*tp++ = *lp++;
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*tp = 0;
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return(tp-lltb);
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}
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int nseel_yylex(compileContext *ctx, char **exp)
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{
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register int c, st;
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int final, l, llk, i;
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register struct lextab *lp;
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char *cp;
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while (1)
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{
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llk = 0;
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if (llset(ctx)) return(0);
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st = 0;
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final = -1;
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lp = &nseel_lextab;
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do {
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if (lp->lllook && (l = lp->lllook[st])) {
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for (c=0; c<NBPW; c++)
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if (l&(1<<c))
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ctx->llsave[c] = ctx->llp1;
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llk++;
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}
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if ((i = lp->llfinal[st]) != -1) {
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final = i;
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ctx->llend = ctx->llp1;
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}
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if ((c = llinp(ctx,exp)) < 0)
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break;
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if ((cp = lp->llbrk) && llk==0 && tst__b(c, cp)) {
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ctx->llp1--;
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break;
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}
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} while ((st = (*lp->llmove)(lp, c, st)) != -1);
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if (ctx->llp2 < ctx->llp1)
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ctx->llp2 = ctx->llp1;
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if (final == -1) {
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ctx->llend = ctx->llp1;
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if (st == 0 && c < 0)
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return(0);
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if ((cp = lp->llill) && tst__b(c, cp)) {
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continue;
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}
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return(YYERRORVAL);
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}
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if ((c = (final >> 11) & 037))
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ctx->llend = ctx->llsave[c-1];
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if ((c = (*lp->llactr)(ctx,final&03777)) >= 0)
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return(c);
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}
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}
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void nseel_llinit(compileContext *ctx)
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{
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ctx->llp1 = ctx->llp2 = ctx->llend = ctx->llbuf;
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ctx->llebuf = ctx->llbuf + sizeof(ctx->llbuf);
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ctx->lleof = ctx->yyline = 0;
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}
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static int llinp(compileContext *ctx, char **exp)
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{
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register int c;
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register struct lextab *lp;
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register char *cp;
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lp = &nseel_lextab;
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cp = lp->llign; /* Ignore class */
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for (;;) {
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/*
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* Get the next character from the save buffer (if possible)
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* If the save buffer's empty, then return EOF or the next
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* input character. Ignore the character if it's in the
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* ignore class.
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*/
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c = (ctx->llp1 < ctx->llp2) ? *ctx->llp1 & 0377 : (ctx->lleof) ? EOF : lexgetc(exp);
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if (c >= 0) { /* Got a character? */
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if (cp && tst__b(c, cp))
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continue; /* Ignore it */
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if (ctx->llp1 >= ctx->llebuf) { /* No, is there room? */
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return -1;
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}
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*ctx->llp1++ = c; /* Store in token buff */
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} else
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ctx->lleof = 1; /* Set EOF signal */
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return(c);
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}
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}
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static int llset(compileContext *ctx)
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/*
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* Return TRUE if EOF and nothing was moved in the look-ahead buffer
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*/
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{
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register char *lp1, *lp2;
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for (lp1 = ctx->llbuf, lp2 = ctx->llend; lp2 < ctx->llp2;)
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*lp1++ = *lp2++;
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ctx->llend = ctx->llp1 = ctx->llbuf;
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ctx->llp2 = lp1;
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return(ctx->lleof && lp1 == ctx->llbuf);
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}
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