File: [local] / src / usr.bin / bc / scan.l (download)
Revision 1.12, Tue Nov 11 19:49:02 2003 UTC (20 years, 6 months ago) by otto
Branch: MAIN
Changes since 1.11: +3 -2 lines
Some syntactic sugar (all non-portable extensions):
- a line comment, starting with #
- opening brace of define statement may be on next line
- return expression, equivalent to return (expression)
|
%{
/* $OpenBSD: scan.l,v 1.12 2003/11/11 19:49:02 otto Exp $ */
/*
* Copyright (c) 2003, Otto Moerbeek <otto@drijf.net>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#ifndef lint
static const char rcsid[] = "$OpenBSD: scan.l,v 1.12 2003/11/11 19:49:02 otto Exp $";
#endif /* not lint */
#include <err.h>
#include <stdbool.h>
#include <string.h>
#include "extern.h"
#include "y.tab.h"
int lineno;
static char *strbuf = NULL;
static size_t strbuf_sz = 1;
static bool dot_seen;
static void init_strbuf(void);
static void add_str(const char *);
%}
DIGIT [0-9A-F]
%x comment string number
%%
"/*" BEGIN(comment);
<comment>{
"*/" BEGIN(INITIAL);
\n lineno++;
\* ;
[^*\n]+ ;
<<EOF>> fatal("end of file in comment");
}
\" BEGIN(string); init_strbuf();
<string>{
[^"\n\\\[\]]+ add_str(yytext);
\[ add_str("\\[");
\] add_str("\\]");
\\ add_str("\\\\");
\n add_str("\n"); lineno++;
\" BEGIN(INITIAL); yylval.str = strbuf; return STRING;
<<EOF>> fatal("end of file in string");
}
{DIGIT}+ {
BEGIN(number);
dot_seen = false;
init_strbuf();
add_str(yytext);
}
\. {
BEGIN(number);
dot_seen = true;
init_strbuf();
add_str(".");
}
<number>{
{DIGIT}+ add_str(yytext);
\. {
if (dot_seen) {
BEGIN(INITIAL);
yylval.str = strbuf;
unput('.');
return NUMBER;
} else {
dot_seen = true;
add_str(".");
}
}
\\\n[ \t]* lineno++;
[^0-9A-F\.] {
BEGIN(INITIAL);
unput(yytext[0]);
if (strcmp(strbuf, ".") == 0)
return DOT;
else {
yylval.str = strbuf;
return NUMBER;
}
}
}
"auto" return AUTO;
"break" return BREAK;
"continue" return CONTINUE;
"define" return DEFINE;
"else" return ELSE;
"ibase" return IBASE;
"if" return IF;
"last" return DOT;
"for" return FOR;
"length" return LENGTH;
"obase" return OBASE;
"print" return PRINT;
"quit" return QUIT;
"return" return RETURN;
"scale" return SCALE;
"sqrt" return SQRT;
"while" return WHILE;
"^" return EXPONENT;
"*" return MULTIPLY;
"/" return DIVIDE;
"%" return REMAINDER;
"+" return PLUS;
"-" return MINUS;
"++" return INCR;
"--" return DECR;
"=" yylval.str = ""; return ASSIGN_OP;
"+=" yylval.str = "+"; return ASSIGN_OP;
"-=" yylval.str = "-"; return ASSIGN_OP;
"*=" yylval.str = "*"; return ASSIGN_OP;
"/=" yylval.str = "/"; return ASSIGN_OP;
"%=" yylval.str = "%"; return ASSIGN_OP;
"^=" yylval.str = "^"; return ASSIGN_OP;
"==" return EQUALS;
"<=" return LESS_EQ;
">=" return GREATER_EQ;
"!=" return UNEQUALS;
"<" return LESS;
">" return GREATER;
"," return COMMA;
";" return SEMICOLON;
"(" return LPAR;
")" return RPAR;
"[" return LBRACKET;
"]" return RBRACKET;
"{" return LBRACE;
"}" return RBRACE;
[a-z] yylval.str = yytext; return LETTER;
\\\n lineno++;
\n lineno++; return NEWLINE;
#[^\n]* ;
[ \t] ;
. yyerror("illegal character");
%%
static void
init_strbuf(void)
{
if (strbuf == NULL) {
strbuf = malloc(strbuf_sz);
if (strbuf == NULL)
err(1, NULL);
}
strbuf[0] = '\0';
}
static void
add_str(const char *str)
{
size_t arglen;
arglen = strlen(str);
if (strlen(strbuf) + arglen + 1> strbuf_sz) {
size_t newsize;
char *p;
newsize = strbuf_sz + arglen + 1;
p = realloc(strbuf, newsize);
if (p == NULL) {
free(strbuf);
err(1, NULL);
}
strbuf_sz = newsize;
strbuf = p;
}
strlcat(strbuf, str, strbuf_sz);
}
void
abort_line(int sig)
{
if (isatty(fileno(yyin))) {
YY_FLUSH_BUFFER;
printf("[\n]P\n");
}
}