Author: delphij Date: Mon Jul 27 19:21:23 2015 New Revision: 285923 URL: https://svnweb.freebsd.org/changeset/base/285923
Log: Rewrite scan procedure with a FSM. This improves code readability by making clear transits between different states, and avoids bug with handling repeated $'s. Reviewed by: bapt Differential Revision: https://reviews.freebsd.org/D3221 Modified: head/usr.bin/ident/ident.c Modified: head/usr.bin/ident/ident.c ============================================================================== --- head/usr.bin/ident/ident.c Mon Jul 27 17:53:11 2015 (r285922) +++ head/usr.bin/ident/ident.c Mon Jul 27 19:21:23 2015 (r285923) @@ -1,5 +1,6 @@ /*- * Copyright (c) 2015 Baptiste Daroussin <[email protected]> + * Copyright (c) 2015 Xin LI <[email protected]> * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -38,68 +39,23 @@ __FBSDID("$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 qu 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); _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "[email protected]"
