d/freebsd-skq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Rewrite scan procedure with a FSM. This improves code readability by

Browse Source 
making clear transits between different states, and avoids bug with
handling repeated $'s.

Reviewed by:	bapt
Differential Revision: https://reviews.freebsd.org/D3221
This commit is contained in:
Xin LI 2015-07-27 19:21:23 +00:00
parent 43bc87c459
commit 7d477dc35a
1 changed files with 129 additions and 60 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

189
usr.bin/ident/ident.c
View File

@ -1,5 +1,6 @@
/*-
* Copyright (c) 2015 Baptiste Daroussin <bapt@FreeBSD.org>
* Copyright (c) 2015 Xin LI <delphij@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
@ -38,68 +39,23 @@ __FBSDID("$FreeBSD$");
#include <unistd.h>
#include <xlocale.h>
static bool
parse_id(FILE *fp, struct sbuf *buf, locale_t l)
{
int c;
bool isid = false;
bool subversion = false;
sbuf_putc(buf, '$');
while ((c = fgetc(fp)) != EOF) {
sbuf_putc(buf, c);
if (!isid) {
if (c == '$') {
sbuf_clear(buf);
sbuf_putc(buf, '$');
continue;
}
if (c == ':') {
c = fgetc(fp);
/* accept :: for subversion compatibility */
if (c == ':') {
subversion = true;
sbuf_putc(buf, c);
c = fgetc(fp);
}
if (c == ' ') {
sbuf_putc(buf, c);
isid = true;
continue;
}
return (false);
}
if (!isalpha_l(c, l))
return (false);
} else {
if (c == '\n')
return (false);
if (c == '$') {
sbuf_finish(buf);
/* should end with a space */
c = sbuf_data(buf)[sbuf_len(buf) - 2];
if (!subversion) {
if (c != ' ')
return (0);
} else if (subversion) {
if (c != ' ' && c != '#')
return (0);
}
printf(" %s\n", sbuf_data(buf));
return (true);
}
}
}
return (false);
}
typedef enum {
/* state condition to transit to next state */
INIT, /* '$' */
DELIM_SEEN, /* letter */
KEYWORD, /* punctuation mark */
PUNC_SEEN, /* ':' -> _SVN; space -> TEXT */
PUNC_SEEN_SVN, /* space */
TEXT
} analyzer_states;
static int
scan(FILE *fp, const char *name, bool quiet)
{
int c;
bool hasid = false;
bool subversion = false;
analyzer_states state = INIT;
struct sbuf *id = sbuf_new_auto();
locale_t l;
@ -109,10 +65,123 @@ scan(FILE *fp, const char *name, bool quiet)
printf("%s:\n", name);
while ((c = fgetc(fp)) != EOF) {
if (c == '$') {
sbuf_clear(id);
if (parse_id(fp, id, l))
hasid = true;
switch (state) {
case INIT:
if (c == '$') {
/* Transit to DELIM_SEEN if we see $ */
state = DELIM_SEEN;
} else {
/* Otherwise, stay in INIT state */
continue;
}
break;
case DELIM_SEEN:
if (isalpha_l(c, l)) {
/* Transit to KEYWORD if we see letter */
sbuf_clear(id);
sbuf_putc(id, '$');
sbuf_putc(id, c);
state = KEYWORD;
continue;
} else if (c == '$') {
/* Or, stay in DELIM_SEEN if more $ */
continue;
} else {
/* Otherwise, transit back to INIT */
state = INIT;
}
break;
case KEYWORD:
sbuf_putc(id, c);
if (isalpha_l(c, l)) {
/*
* Stay in KEYWORD if additional letter is seen
*/
continue;
} else if (c == ':') {
/*
* See ':' for the first time, transit to
* PUNC_SEEN.
*/
state = PUNC_SEEN;
subversion = false;
} else if (c == '$') {
/*
* Incomplete ident. Go back to DELIM_SEEN
* state because we see a '$' which could be
* the beginning of a keyword.
*/
state = DELIM_SEEN;
} else {
/*
* Go back to INIT state otherwise.
*/
state = INIT;
}
break;
case PUNC_SEEN:
case PUNC_SEEN_SVN:
sbuf_putc(id, c);
switch (c) {
case ':':
/*
* If we see '::' (seen : in PUNC_SEEN),
* activate subversion treatment and transit
* to PUNC_SEEN_SVN state.
*
* If more than two :'s were seen, the ident
* is invalid and we would therefore go back
* to INIT state.
*/
if (state == PUNC_SEEN) {
state = PUNC_SEEN_SVN;
subversion = true;
} else {
state = INIT;
}
break;
case ' ':
/*
* A space after ':' or '::' indicates we are at the
* last component of potential ident.
*/
state = TEXT;
break;
default:
/* All other characters are invalid */
state = INIT;
break;
}
break;
case TEXT:
sbuf_putc(id, c);
if (iscntrl_l(c, l)) {
/* Control characters are not allowed in this state */
state = INIT;
} else if (c == '$') {
sbuf_finish(id);
/*
* valid ident should end with a space.
*
* subversion extension uses '#' to indicate that
* the keyword expansion have exceeded the fixed
* width, so it is also permitted if we are in
* subversion mode. No length check is enforced
* because GNU RCS ident(1) does not do it either.
*/
c = sbuf_data(id)[sbuf_len(id) - 2];
if (c == ' ' || (subversion && c == '#')) {
printf(" %s\n", sbuf_data(id));
hasid = true;
}
state = INIT;
}
/* Other characters: stay in the state */
break;
}
}
sbuf_delete(id);