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RCSLEX.C
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1991-01-30
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/*
* RCS file input
*/
/*********************************************************************************
* Lexical Analysis.
* hashtable, Lexinit, nextlex, getlex, getkey,
* getid, getnum, readstring, printstring, savestring,
* checkid, fatserror, error, faterror, warn, diagnose
* Testprogram: define LEXDB
*********************************************************************************
*/
/* Copyright (C) 1982, 1988, 1989 Walter Tichy
Copyright 1990 by Paul Eggert
Distributed under license by the Free Software Foundation, Inc.
This file is part of RCS.
RCS is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 1, or (at your option)
any later version.
RCS is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with RCS; see the file COPYING. If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
Report problems and direct all questions to:
rcs-bugs@cs.purdue.edu
*/
/* $Log: rcslex.c,v $
* Revision 5.6 1991/01/30 14:21:32 apratt
* CI with RCS version 5
*
* Revision 5.5 90/12/04 05:18:47 eggert
* checked in with -k by apratt at 91.01.10.13.15.22.
*
* Revision 5.5 1990/12/04 05:18:47 eggert
* Use -I for prompts and -q for diagnostics.
*
* Revision 5.4 1990/11/19 20:05:28 hammer
* no longer gives warning about unknown keywords if -q is specified
*
* Revision 5.3 1990/11/01 05:03:48 eggert
* When ignoring unknown phrases, copy them to the output RCS file.
*
* Revision 5.2 1990/09/04 08:02:27 eggert
* Count RCS lines better.
*
* Revision 5.1 1990/08/29 07:14:03 eggert
* Work around buggy compilers with defective argument promotion.
*
* Revision 5.0 1990/08/22 08:12:55 eggert
* Remove compile-time limits; use malloc instead.
* Report errno-related errors with perror().
* Ansify and Posixate. Add support for ISO 8859.
* Use better hash function.
*
* Revision 4.6 89/05/01 15:13:07 narten
* changed copyright header to reflect current distribution rules
*
* Revision 4.5 88/08/28 15:01:12 eggert
* Don't loop when writing error messages to a full filesystem.
* Flush stderr/stdout when mixing output.
* Yield exit status compatible with diff(1).
* Shrink stdio code size; allow cc -R; remove lint.
*
* Revision 4.4 87/12/18 11:44:47 narten
* fixed to use "varargs" in "fprintf"; this is required if it is to
* work on a SPARC machine such as a Sun-4
*
* Revision 4.3 87/10/18 10:37:18 narten
* Updating version numbers. Changes relative to 1.1 actually relative
* to version 4.1
*
* Revision 1.3 87/09/24 14:00:17 narten
* Sources now pass through lint (if you ignore printf/sprintf/fprintf
* warnings)
*
* Revision 1.2 87/03/27 14:22:33 jenkins
* Port to suns
*
* Revision 4.1 83/03/25 18:12:51 wft
* Only changed $Header to $Id.
*
* Revision 3.3 82/12/10 16:22:37 wft
* Improved error messages, changed exit status on error to 1.
*
* Revision 3.2 82/11/28 21:27:10 wft
* Renamed ctab to map and included EOFILE; ctab is now a macro in rcsbase.h.
* Added fflsbuf(), fputs(), and fprintf(), which abort the RCS operations
* properly in case there is an IO-error (e.g., file system full).
*
* Revision 3.1 82/10/11 19:43:56 wft
* removed unused label out:;
* made sure all calls to getc() return into an integer, not a char.
*/
/*
#define LEXDB
*/
/* version LEXDB is for testing the lexical analyzer. The testprogram
* reads a stream of lexemes, enters the revision numbers into the
* hashtable, and prints the recognized tokens. Keywords are recognized
* as identifiers.
*/
#include "rcsbase.h"
libId(lexId, "$Id: rcslex.c,v 5.6 1991/01/30 14:21:32 apratt Exp $")
static struct hshentry *nexthsh; /*pointer to next hash entry, set by lookup*/
enum tokens nexttok; /*next token, set by nextlex */
int hshenter; /*if true, next suitable lexeme will be entered */
/*into the symbol table. Handle with care. */
int nextc; /*next input character, initialized by Lexinit */
unsigned long rcsline; /*current line-number of input */
int nerror; /*counter for errors */
int quietflag; /*indicates quiet mode */
FILE * finptr; /*input file descriptor */
FILE * frewrite; /*file descriptor for echoing input */
FILE * foutptr; /* copy of frewrite, but NULL to suppress echo */
static struct buf tokbuf; /* token buffer */
const char * NextString; /* next token */
/*
* Our hash algorithm is h[0] = 0, h[i+1] = 4*h[i] + c,
* so hshsize should be odd.
* See B J McKenzie, R Harries & T Bell, Selecting a hashing algorithm,
* Software--practice & experience 20, 2 (Feb 1990), 209-224.
*/
#ifndef hshsize
# define hshsize 511
#endif
static struct hshentry *hshtab[hshsize]; /*hashtable */
static int ignored_phrases; /* have we ignored phrases in this RCS file? */
void
warnignore()
{
if (! (ignored_phrases|quietflag)) {
ignored_phrases = true;
warn("Unknown phrases like `%s ...;' are in the RCS file.", NextString);
}
}
static void
lookup(str)
const char *str;
/* Function: Looks up the character string pointed to by str in the
* hashtable. If the string is not present, a new entry for it is created.
* In any case, the address of the corresponding hashtable entry is placed
* into nexthsh.
*/
{
register unsigned ihash; /* index into hashtable */
register const char *sp;
register struct hshentry *n, **p;
/* calculate hash code */
sp = str;
ihash = 0;
while (*sp)
ihash = (ihash<<2) + *sp++;
ihash %= hshsize;
for (p = &hshtab[ihash]; ; p = &n->nexthsh)
if (!(n = *p)) {
/* empty slot found */
*p = n = ftalloc(struct hshentry);
n->num = fstrsave(str);
n->nexthsh = nil;
# ifdef LEXDB
VOID printf("\nEntered: %s at %u ", str, ihash);
# endif
break;
} else if (strcmp(str, n->num) == 0)
/* match found */
break;
nexthsh = n;
NextString = n->num;
}
void
Lexinit()
/* Function: Initialization of lexical analyzer:
* initializes the hashtable,
* initializes nextc, nexttok if finptr != NULL
*/
{ register int c;
for (c = hshsize; 0 <= --c; ) {
hshtab[c] = nil;
}
hshenter=true; rcsline=1; nerror=0;
ignored_phrases = false;
bufrealloc(&tokbuf, 2);
if (finptr) {
GETC(finptr,foutptr,c);
nextc = c; /*initial character*/
nexttok = DELIM; /* anything but EOFILE */
nextlex(); /*initial token*/
} else {
nextc = '\0';
nexttok=EOFILE;
}
}
static exiting void
unexpectedEOF()
{
fatserror("unexpected EOF");
}
void
nextlex()
/* Function: Reads the next token and sets nexttok to the next token code.
* Only if hshenter is set, a revision number is entered into the
* hashtable and a pointer to it is placed into nexthsh.
* This is useful for avoiding that dates are placed into the hashtable.
* For ID's and NUM's, NextString is set to the character string.
* Assumption: nextc contains the next character.
*/
{ register c;
register FILE * fin, * frew;
register char * sp;
const char *lim;
register enum tokens d;
if (nexttok == EOFILE)
unexpectedEOF();
fin=finptr; frew=foutptr;