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scan.l
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scan.l
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/* $Id$ $Revision$ */
/* vim:set shiftwidth=4 ts=8: */
/*************************************************************************
* Copyright (c) 2011 AT&T Intellectual Property
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors: See CVS logs. Details at http://www.graphviz.org/
*************************************************************************/
/* requires flex (i.e. not lex) */
%{
#include <grammar.h>
#include <cghdr.h>
#include <agxbuf.h>
#include <ctype.h>
#define GRAPH_EOF_TOKEN '@' /* lex class must be defined below */
/* this is a workaround for linux flex */
static int line_num = 1;
static int html_nest = 0; /* nesting level for html strings */
static char* InputFile;
static Agdisc_t *Disc;
static void *Ifile;
static int graphType;
/* Reset line number */
void agreadline(int n) { line_num = n; }
/* (Re)set file:
*/
void agsetfile(char* f) { InputFile = f; line_num = 1; }
/* There is a hole here, because switching channels
* requires pushing back whatever was previously read.
* There probably is a right way of doing this.
*/
void aglexinit(Agdisc_t *disc, void *ifile) { Disc = disc; Ifile = ifile; graphType = 0;}
#define isatty(x) 0
#ifndef YY_INPUT
#define YY_INPUT(buf,result,max_size) \
if ((result = Disc->io->afread(Ifile, buf, max_size)) < 0) \
YY_FATAL_ERROR( "input in flex scanner failed" )
#endif
/* buffer for arbitrary length strings (longer than BUFSIZ) */
static char *Sbuf,*Sptr,*Send;
static void beginstr(void) {
if (Sbuf == NIL(char*)) {
Sbuf = malloc(BUFSIZ);
Send = Sbuf + BUFSIZ;
}
Sptr = Sbuf;
*Sptr = 0;
}
static void addstr(char *src) {
char c;
if (Sptr > Sbuf) Sptr--;
do {
do {c = *Sptr++ = *src++;} while (c && (Sptr < Send));
if (c) {
long sz = Send - Sbuf;
long off = Sptr - Sbuf;
sz *= 2;
Sbuf = (char*)realloc(Sbuf,sz);
Send = Sbuf + sz;
Sptr = Sbuf + off;
}
} while (c);
}
static void endstr(void) {
yylval.str = (char*)agstrdup(Ag_G_global,Sbuf);
*Sbuf = 0;
}
static void endstr_html(void) {
yylval.str = (char*)agstrdup_html(Ag_G_global,Sbuf);
*Sbuf = 0;
}
static void
storeFileName (char* fname, int len)
{
static int cnt;
static char* buf;
if (len > cnt) {
if (cnt) buf = (char*)realloc (buf, len+1);
else buf = (char*)malloc (len+1);
cnt = len;
}
strcpy (buf, fname);
InputFile = buf;
}
/* ppDirective:
* Process a possible preprocessor line directive.
* yytext = #.*
*/
static void ppDirective (void)
{
int r, cnt, lineno;
char buf[2];
char* s = yytext + 1; /* skip initial # */
if (strncmp(s, "line", 4) == 0) s += 4;
r = sscanf(s, "%d %1[\"]%n", &lineno, buf, &cnt);
if (r > 0) { /* got line number */
line_num = lineno - 1;
if (r > 1) { /* saw quote */
char* p = s + cnt;
char* e = p;
while (*e && (*e != '"')) e++;
if (e != p) {
*e = '\0';
storeFileName (p, e-p);
}
}
}
}
/* twoDots:
* Return true if token has more than one '.';
* we know the last character is a '.'.
*/
static int twoDots(void)
{
int i;
for (i = yyleng-2; i >= 0; i--) {
if (((unsigned char)yytext[i]) == '.')
return 1;
}
return 0;
}
/* chkNum:
* The regexp for NUMBER allows a terminating letter or '.'.
* This way we can catch a number immediately followed by a name
* or something like 123.456.78, and report this to the user.
*/
static int chkNum(void) {
unsigned char c = (unsigned char)yytext[yyleng-1]; /* last character */
if ((!isdigit(c) && (c != '.')) || ((c == '.') && twoDots())) { /* c is letter */
unsigned char xbuf[BUFSIZ];
char buf[BUFSIZ];
agxbuf xb;
char* fname;
if (InputFile)
fname = InputFile;
else
fname = "input";
agxbinit(&xb, BUFSIZ, xbuf);
agxbput(&xb,"syntax ambiguity - badly delimited number '");
agxbput(&xb,yytext);
sprintf(buf,"' in line %d of ", line_num);
agxbput(&xb,buf);
agxbput(&xb,fname);
agxbput(&xb, " splits into two tokens\n");
agerr(AGWARN,agxbuse(&xb));
agxbfree(&xb);
return 1;
}
else return 0;
}
/* The LETTER class below consists of ascii letters, underscore, all non-ascii
* characters. This allows identifiers to have characters from any
* character set independent of locale. The downside is that, for certain
* character sets, non-letter and, in fact, undefined characters will be
* accepted. This is not likely and, from dot's stand, shouldn't do any
* harm. (Presumably undefined characters will be ignored in display.) And,
* it allows a greater wealth of names. */
%}
GRAPH_EOF_TOKEN [@]
LETTER [A-Za-z_\200-\377]
DIGIT [0-9]
NAME {LETTER}({LETTER}|{DIGIT})*
NUMBER [-]?(({DIGIT}+(\.{DIGIT}*)?)|(\.{DIGIT}+))(\.|{LETTER})?
ID ({NAME}|{NUMBER})
%x comment
%x qstring
%x hstring
%%
{GRAPH_EOF_TOKEN} return(EOF);
<INITIAL,comment,qstring>\n line_num++;
"/*" BEGIN(comment);
<comment>[^*\n]* /* eat anything not a '*' */
<comment>"*"+[^*/\n]* /* eat up '*'s not followed by '/'s */
<comment>"*"+"/" BEGIN(INITIAL);
"//".* /* ignore C++-style comments */
^"#".* ppDirective ();
"#".* /* ignore shell-like comments */
[ \t\r] /* ignore whitespace */
"\xEF\xBB\xBF" /* ignore BOM */
"node" return(T_node); /* see tokens in agcanonstr */
"edge" return(T_edge);
"graph" if (!graphType) graphType = T_graph; return(T_graph);
"digraph" if (!graphType) graphType = T_digraph; return(T_digraph);
"strict" return(T_strict);
"subgraph" return(T_subgraph);
"->" if (graphType == T_digraph) return(T_edgeop); else return('-');
"--" if (graphType == T_graph) return(T_edgeop); else return('-');
{NAME} { yylval.str = (char*)agstrdup(Ag_G_global,yytext); return(T_atom); }
{NUMBER} { if (chkNum()) yyless(yyleng-1); yylval.str = (char*)agstrdup(Ag_G_global,yytext); return(T_atom); }
["] BEGIN(qstring); beginstr();
<qstring>["] BEGIN(INITIAL); endstr(); return (T_qatom);
<qstring>[\\]["] addstr ("\"");
<qstring>[\\][\\] addstr ("\\\\");
<qstring>[\\][\n] line_num++; /* ignore escaped newlines */
<qstring>([^"\\]*|[\\]) addstr(yytext);
[<] BEGIN(hstring); html_nest = 1; beginstr();
<hstring>[>] html_nest--; if (html_nest) addstr(yytext); else {BEGIN(INITIAL); endstr_html(); return (T_qatom);}
<hstring>[<] html_nest++; addstr(yytext);
<hstring>[\n] addstr(yytext); line_num++; /* add newlines */
<hstring>([^><\n]*) addstr(yytext);
. return (yytext[0]);
%%
void yyerror(char *str)
{
unsigned char xbuf[BUFSIZ];
char buf[BUFSIZ];
agxbuf xb;
agxbinit(&xb, BUFSIZ, xbuf);
if (InputFile) {
agxbput (&xb, InputFile);
agxbput (&xb, ": ");
}
agxbput (&xb, str);
sprintf(buf," in line %d", line_num);
agxbput (&xb, buf);
if (*yytext) {
agxbput(&xb," near '");
agxbput (&xb, yytext);
agxbputc (&xb, '\'');
}
else switch (YYSTATE) {
case qstring :
sprintf(buf, " scanning a quoted string (missing endquote? longer than %d?)", YY_BUF_SIZE);
agxbput (&xb, buf);
if (*Sbuf) {
int len = strlen(Sbuf);
agxbput (&xb, "\nString starting:\"");
if (len > 80)
Sbuf[80] = '\0';
agxbput (&xb, Sbuf);
}
break;
case hstring :
sprintf(buf, " scanning a HTML string (missing '>'? bad nesting? longer than %d?)", YY_BUF_SIZE);
agxbput (&xb, buf);
if (*Sbuf) {
int len = strlen(Sbuf);
agxbput (&xb, "\nString starting:<");
if (len > 80)
Sbuf[80] = '\0';
agxbput (&xb, Sbuf);
}
break;
case comment :
sprintf(buf, " scanning a /*...*/ comment (missing '*/? longer than %d?)", YY_BUF_SIZE);
agxbput (&xb, buf);
break;
}
agxbputc (&xb, '\n');
agerr(AGERR, "%s", agxbuse(&xb));
agxbfree(&xb);
}
/* must be here to see flex's macro defns */
void aglexeof() { unput(GRAPH_EOF_TOKEN); }
void aglexbad() { YY_FLUSH_BUFFER; }
#ifndef YY_CALL_ONLY_ARG
# define YY_CALL_ONLY_ARG void
#endif
int yywrap(YY_CALL_ONLY_ARG)
{
return 1;
}