keyword-gen.c revision 290001
1/*
2 * keyword-gen.c -- generate keyword scanner finite state machine and
3 *		    keyword_text array.
4 *
5 * This program is run to generate ntp_keyword.h
6 * After making a change here, two output files should be committed at
7 * the same time as keyword-gen.c:
8 *	ntp_keyword.h
9 *	keyword-gen-utd
10 *
11 * keyword-gen-utd is a sentinel used by Makefile.am to avoid compiling
12 * keyword_gen.c and generating ntp_keyword.h if the input keyword-gen.c
13 * has not changed.  This is not solely an optimization, it also breaks
14 * a dependency chain that otherwise would cause programs to be compiled
15 * when running "make dist" or "make distdir".  We want these to package
16 * the existing source without building anything but a tarball.  See
17 * [Bug 1470].
18 */
19#include <config.h>
20#include <stdio.h>
21#include <stdlib.h>
22#include <time.h>
23
24#include <ntp_stdlib.h>
25#include <ntp_config.h>
26#include <lib_strbuf.h>
27#include "ntp_scanner.h"
28#include "ntp_parser.h"
29
30
31/* Define a structure to hold a (keyword, token) pair */
32struct key_tok {
33	char *	key;		/* Keyword */
34	u_short	token;		/* Associated Token */
35	follby	followedby;	/* nonzero indicates the next token(s)
36				   forced to be string(s) */
37};
38
39struct key_tok ntp_keywords[] = {
40{ "...",		T_Ellipsis,		FOLLBY_TOKEN },
41{ "allpeers",		T_Allpeers,		FOLLBY_TOKEN },
42{ "automax",		T_Automax,		FOLLBY_TOKEN },
43{ "broadcast",		T_Broadcast,		FOLLBY_STRING },
44{ "broadcastclient",	T_Broadcastclient,	FOLLBY_TOKEN },
45{ "broadcastdelay",	T_Broadcastdelay,	FOLLBY_TOKEN },
46{ "ctl",		T_Ctl,			FOLLBY_TOKEN },
47{ "disable",		T_Disable,		FOLLBY_TOKEN },
48{ "driftfile",		T_Driftfile,		FOLLBY_STRING },
49{ "dscp",		T_Dscp,			FOLLBY_TOKEN },
50{ "enable",		T_Enable,		FOLLBY_TOKEN },
51{ "end",		T_End,			FOLLBY_TOKEN },
52{ "filegen",		T_Filegen,		FOLLBY_TOKEN },
53{ "fudge",		T_Fudge,		FOLLBY_STRING },
54{ "io",			T_Io,			FOLLBY_TOKEN },
55{ "includefile",	T_Includefile,		FOLLBY_STRING },
56{ "leapfile",		T_Leapfile,		FOLLBY_STRING },
57{ "leapsmearinterval",	T_Leapsmearinterval,	FOLLBY_TOKEN },
58{ "logconfig",		T_Logconfig,		FOLLBY_STRINGS_TO_EOC },
59{ "logfile",		T_Logfile,		FOLLBY_STRING },
60{ "manycastclient",	T_Manycastclient,	FOLLBY_STRING },
61{ "manycastserver",	T_Manycastserver,	FOLLBY_STRINGS_TO_EOC },
62{ "mem",		T_Mem,			FOLLBY_TOKEN },
63{ "multicastclient",	T_Multicastclient,	FOLLBY_STRINGS_TO_EOC },
64{ "peer",		T_Peer,			FOLLBY_STRING },
65{ "phone",		T_Phone,		FOLLBY_STRINGS_TO_EOC },
66{ "pidfile",		T_Pidfile,		FOLLBY_STRING },
67{ "pool",		T_Pool,			FOLLBY_STRING },
68{ "discard",		T_Discard,		FOLLBY_TOKEN },
69{ "reset",		T_Reset,		FOLLBY_TOKEN },
70{ "restrict",		T_Restrict,		FOLLBY_TOKEN },
71{ "rlimit",		T_Rlimit,		FOLLBY_TOKEN },
72{ "server",		T_Server,		FOLLBY_STRING },
73{ "setvar",		T_Setvar,		FOLLBY_STRING },
74{ "statistics",		T_Statistics,		FOLLBY_TOKEN },
75{ "statsdir",		T_Statsdir,		FOLLBY_STRING },
76{ "sys",		T_Sys,			FOLLBY_TOKEN },
77{ "tick",		T_Tick,			FOLLBY_TOKEN },
78{ "timer",		T_Timer,		FOLLBY_TOKEN },
79{ "tinker",		T_Tinker,		FOLLBY_TOKEN },
80{ "tos",		T_Tos,			FOLLBY_TOKEN },
81{ "trap",		T_Trap,			FOLLBY_STRING },
82{ "unconfig",		T_Unconfig,		FOLLBY_STRING },
83{ "unpeer",		T_Unpeer,		FOLLBY_STRING },
84/* authentication_command */
85{ "controlkey",		T_ControlKey,		FOLLBY_TOKEN },
86{ "crypto",		T_Crypto,		FOLLBY_TOKEN },
87{ "keys",		T_Keys,			FOLLBY_STRING },
88{ "keysdir",		T_Keysdir,		FOLLBY_STRING },
89{ "ntpsigndsocket",	T_NtpSignDsocket,	FOLLBY_STRING },
90{ "requestkey",		T_Requestkey,		FOLLBY_TOKEN },
91{ "revoke",		T_Revoke,		FOLLBY_TOKEN },
92{ "trustedkey",		T_Trustedkey,		FOLLBY_TOKEN },
93/* IPv4/IPv6 protocol override flag */
94{ "-4",			T_Ipv4_flag,		FOLLBY_TOKEN },
95{ "-6",			T_Ipv6_flag,		FOLLBY_TOKEN },
96/* option */
97{ "autokey",		T_Autokey,		FOLLBY_TOKEN },
98{ "burst",		T_Burst,		FOLLBY_TOKEN },
99{ "iburst",		T_Iburst,		FOLLBY_TOKEN },
100{ "key",		T_Key,			FOLLBY_TOKEN },
101{ "maxpoll",		T_Maxpoll,		FOLLBY_TOKEN },
102{ "mdnstries",		T_Mdnstries,		FOLLBY_TOKEN },
103{ "minpoll",		T_Minpoll,		FOLLBY_TOKEN },
104{ "mode",		T_Mode,			FOLLBY_TOKEN },
105{ "noselect",		T_Noselect,		FOLLBY_TOKEN },
106{ "preempt",		T_Preempt,		FOLLBY_TOKEN },
107{ "true",		T_True,			FOLLBY_TOKEN },
108{ "prefer",		T_Prefer,		FOLLBY_TOKEN },
109{ "ttl",		T_Ttl,			FOLLBY_TOKEN },
110{ "version",		T_Version,		FOLLBY_TOKEN },
111{ "xleave",		T_Xleave,		FOLLBY_TOKEN },
112/* crypto_command */
113{ "host",		T_Host,			FOLLBY_STRING },
114{ "ident",		T_Ident,		FOLLBY_STRING },
115{ "pw",			T_Pw,			FOLLBY_STRING },
116{ "randfile",		T_Randfile,		FOLLBY_STRING },
117{ "digest",		T_Digest,		FOLLBY_STRING },
118/*** MONITORING COMMANDS ***/
119/* stat */
120{ "clockstats",		T_Clockstats,		FOLLBY_TOKEN },
121{ "cryptostats",	T_Cryptostats,		FOLLBY_TOKEN },
122{ "loopstats",		T_Loopstats,		FOLLBY_TOKEN },
123{ "peerstats",		T_Peerstats,		FOLLBY_TOKEN },
124{ "rawstats",		T_Rawstats,		FOLLBY_TOKEN },
125{ "sysstats", 		T_Sysstats,		FOLLBY_TOKEN },
126{ "protostats",		T_Protostats,		FOLLBY_TOKEN },
127{ "timingstats",	T_Timingstats,		FOLLBY_TOKEN },
128/* filegen_option */
129{ "file",		T_File,			FOLLBY_STRING },
130{ "link",		T_Link,			FOLLBY_TOKEN },
131{ "nolink",		T_Nolink,		FOLLBY_TOKEN },
132{ "type",		T_Type,			FOLLBY_TOKEN },
133/* filegen_type */
134{ "age",		T_Age,			FOLLBY_TOKEN },
135{ "day",		T_Day,			FOLLBY_TOKEN },
136{ "month",		T_Month,		FOLLBY_TOKEN },
137{ "none",		T_None,			FOLLBY_TOKEN },
138{ "pid",		T_Pid,			FOLLBY_TOKEN },
139{ "week",		T_Week,			FOLLBY_TOKEN },
140{ "year",		T_Year,			FOLLBY_TOKEN },
141/*** ORPHAN MODE COMMANDS ***/
142/* tos_option */
143{ "minclock",		T_Minclock,		FOLLBY_TOKEN },
144{ "maxclock",		T_Maxclock,		FOLLBY_TOKEN },
145{ "minsane",		T_Minsane,		FOLLBY_TOKEN },
146{ "floor",		T_Floor,		FOLLBY_TOKEN },
147{ "ceiling",		T_Ceiling,		FOLLBY_TOKEN },
148{ "cohort",		T_Cohort,		FOLLBY_TOKEN },
149{ "mindist",		T_Mindist,		FOLLBY_TOKEN },
150{ "maxdist",		T_Maxdist,		FOLLBY_TOKEN },
151{ "beacon",		T_Beacon,		FOLLBY_TOKEN },
152{ "orphan",		T_Orphan,		FOLLBY_TOKEN },
153{ "orphanwait",		T_Orphanwait,		FOLLBY_TOKEN },
154{ "nonvolatile",	T_Nonvolatile,		FOLLBY_TOKEN },
155/* access_control_flag */
156{ "default",		T_Default,		FOLLBY_TOKEN },
157{ "source",		T_Source,		FOLLBY_TOKEN },
158{ "flake",		T_Flake,		FOLLBY_TOKEN },
159{ "ignore",		T_Ignore,		FOLLBY_TOKEN },
160{ "limited",		T_Limited,		FOLLBY_TOKEN },
161{ "mssntp",		T_Mssntp,		FOLLBY_TOKEN },
162{ "kod",		T_Kod,			FOLLBY_TOKEN },
163{ "lowpriotrap",	T_Lowpriotrap,		FOLLBY_TOKEN },
164{ "mask",		T_Mask,			FOLLBY_TOKEN },
165{ "nomodify",		T_Nomodify,		FOLLBY_TOKEN },
166{ "nomrulist",		T_Nomrulist,		FOLLBY_TOKEN },
167{ "nopeer",		T_Nopeer,		FOLLBY_TOKEN },
168{ "noquery",		T_Noquery,		FOLLBY_TOKEN },
169{ "noserve",		T_Noserve,		FOLLBY_TOKEN },
170{ "notrap",		T_Notrap,		FOLLBY_TOKEN },
171{ "notrust",		T_Notrust,		FOLLBY_TOKEN },
172{ "ntpport",		T_Ntpport,		FOLLBY_TOKEN },
173/* discard_option */
174{ "average",		T_Average,		FOLLBY_TOKEN },
175{ "minimum",		T_Minimum,		FOLLBY_TOKEN },
176{ "monitor",		T_Monitor,		FOLLBY_TOKEN },
177/* mru_option */
178{ "incalloc",		T_Incalloc,		FOLLBY_TOKEN },
179{ "incmem",		T_Incmem,		FOLLBY_TOKEN },
180{ "initalloc",		T_Initalloc,		FOLLBY_TOKEN },
181{ "initmem",		T_Initmem,		FOLLBY_TOKEN },
182{ "mindepth",		T_Mindepth,		FOLLBY_TOKEN },
183{ "maxage",		T_Maxage,		FOLLBY_TOKEN },
184{ "maxdepth",		T_Maxdepth,		FOLLBY_TOKEN },
185{ "maxmem",		T_Maxmem,		FOLLBY_TOKEN },
186{ "mru",		T_Mru,			FOLLBY_TOKEN },
187/* fudge_factor */
188{ "abbrev",		T_Abbrev,		FOLLBY_STRING },
189{ "flag1",		T_Flag1,		FOLLBY_TOKEN },
190{ "flag2",		T_Flag2,		FOLLBY_TOKEN },
191{ "flag3",		T_Flag3,		FOLLBY_TOKEN },
192{ "flag4",		T_Flag4,		FOLLBY_TOKEN },
193{ "refid",		T_Refid,		FOLLBY_STRING },
194{ "stratum",		T_Stratum,		FOLLBY_TOKEN },
195{ "time1",		T_Time1,		FOLLBY_TOKEN },
196{ "time2",		T_Time2,		FOLLBY_TOKEN },
197/* system_option */
198{ "auth",		T_Auth,			FOLLBY_TOKEN },
199{ "bclient",		T_Bclient,		FOLLBY_TOKEN },
200{ "calibrate",		T_Calibrate,		FOLLBY_TOKEN },
201{ "kernel",		T_Kernel,		FOLLBY_TOKEN },
202{ "ntp",		T_Ntp,			FOLLBY_TOKEN },
203{ "mode7",		T_Mode7,		FOLLBY_TOKEN },
204{ "stats",		T_Stats,		FOLLBY_TOKEN },
205/* rlimit_option */
206{ "memlock",		T_Memlock,		FOLLBY_TOKEN },
207{ "stacksize",		T_Stacksize,		FOLLBY_TOKEN },
208{ "filenum",		T_Filenum,		FOLLBY_TOKEN },
209/* tinker_option */
210{ "step",		T_Step,			FOLLBY_TOKEN },
211{ "stepback",		T_Stepback,		FOLLBY_TOKEN },
212{ "stepfwd",		T_Stepfwd,		FOLLBY_TOKEN },
213{ "panic",		T_Panic,		FOLLBY_TOKEN },
214{ "dispersion",		T_Dispersion,		FOLLBY_TOKEN },
215{ "stepout",		T_Stepout,		FOLLBY_TOKEN },
216{ "allan",		T_Allan,		FOLLBY_TOKEN },
217{ "huffpuff",		T_Huffpuff,		FOLLBY_TOKEN },
218{ "freq",		T_Freq,			FOLLBY_TOKEN },
219/* miscellaneous_command */
220{ "port",		T_Port,			FOLLBY_TOKEN },
221{ "interface",		T_Interface,		FOLLBY_TOKEN },
222{ "saveconfigdir",	T_Saveconfigdir,	FOLLBY_STRING },
223/* interface_command (ignore and interface already defined) */
224{ "nic",		T_Nic,			FOLLBY_TOKEN },
225{ "all",		T_All,			FOLLBY_TOKEN },
226{ "ipv4",		T_Ipv4,			FOLLBY_TOKEN },
227{ "ipv6",		T_Ipv6,			FOLLBY_TOKEN },
228{ "wildcard",		T_Wildcard,		FOLLBY_TOKEN },
229{ "listen",		T_Listen,		FOLLBY_TOKEN },
230{ "drop",		T_Drop,			FOLLBY_TOKEN },
231/* simulator commands */
232{ "simulate",		T_Simulate,		FOLLBY_TOKEN },
233{ "simulation_duration",T_Sim_Duration,		FOLLBY_TOKEN },
234{ "beep_delay",		T_Beep_Delay,		FOLLBY_TOKEN },
235{ "duration",		T_Duration,		FOLLBY_TOKEN },
236{ "server_offset",	T_Server_Offset,	FOLLBY_TOKEN },
237{ "freq_offset",	T_Freq_Offset,		FOLLBY_TOKEN },
238{ "wander",		T_Wander,		FOLLBY_TOKEN },
239{ "jitter",		T_Jitter,		FOLLBY_TOKEN },
240{ "prop_delay",		T_Prop_Delay,		FOLLBY_TOKEN },
241{ "proc_delay",		T_Proc_Delay,		FOLLBY_TOKEN },
242};
243
244typedef struct big_scan_state_tag {
245	char	ch;		/* Character this state matches on */
246	char	followedby;	/* Forces next token(s) to T_String */
247	u_short	finishes_token;	/* nonzero ID if last keyword char */
248	u_short	match_next_s;	/* next state to check matching ch */
249	u_short	other_next_s;	/* next state to check if not ch */
250} big_scan_state;
251
252/*
253 * Note: to increase MAXSTATES beyond 2048, be aware it is currently
254 * crammed into 11 bits in scan_state form.  Raising to 4096 would be
255 * relatively easy by storing the followedby value in a separate
256 * array with one entry per token, and shrinking the char value to
257 * 7 bits to free a bit for accepting/non-accepting.  More than 4096
258 * states will require expanding scan_state beyond 32 bits each.
259 */
260#define MAXSTATES	2048
261#define MAX_TOK_LEN	63
262
263const char *	current_keyword;/* for error reporting */
264big_scan_state	sst[MAXSTATES];	/* scanner FSM state entries */
265u_short		sst_highwater;	/* next entry index to consider */
266char *		symb[1024];	/* map token ID to symbolic name */
267
268/* for libntp */
269const char *	progname = "keyword-gen";
270
271int		main			(int, char **);
272static void	generate_preamble	(void);
273static void	generate_fsm		(void);
274static void	generate_token_text	(void);
275static u_short	create_keyword_scanner	(void);
276static u_short	create_scan_states	(char *, u_short, follby, u_short);
277int		compare_key_tok_id	(const void *, const void *);
278int		compare_key_tok_text	(const void *, const void *);
279void		populate_symb		(char *);
280const char *	symbname		(u_short);
281
282
283int main(int argc, char **argv)
284{
285	if (argc < 2) {
286		fprintf(stderr, "Usage:\n%s t_header.h\n", argv[0]);
287		exit(1);
288	}
289	debug = 1;
290
291	populate_symb(argv[1]);
292
293	generate_preamble();
294	generate_token_text();
295	generate_fsm();
296
297	return 0;
298}
299
300
301static void
302generate_preamble(void)
303{
304	time_t now;
305	char timestamp[128];
306	char preamble[] =
307"/*\n"
308" * ntp_keyword.h\n"
309" * \n"
310" * NOTE: edit this file with caution, it is generated by keyword-gen.c\n"
311" *\t Generated %s UTC	  diff_ignore_line\n"
312" *\n"
313" */\n"
314"#include \"ntp_scanner.h\"\n"
315"#include \"ntp_parser.h\"\n"
316"\n";
317
318	time(&now);
319	if (!strftime(timestamp, sizeof(timestamp),
320		      "%Y-%m-%d %H:%M:%S", gmtime(&now)))
321		timestamp[0] = '\0';
322
323	printf(preamble, timestamp);
324}
325
326
327static void
328generate_fsm(void)
329{
330	char rprefix[MAX_TOK_LEN + 1];
331	char prefix[MAX_TOK_LEN + 1];
332	char token_id_comment[16 + MAX_TOK_LEN + 1];
333	size_t prefix_len;
334	char *p;
335	char *r;
336	u_short initial_state;
337	u_short this_state;
338	u_short state;
339	u_short i;
340	u_short token;
341
342	/*
343	 * Sort ntp_keywords in alphabetical keyword order.  This is
344	 * not necessary, but minimizes nonfunctional changes in the
345	 * generated finite state machine when keywords are modified.
346	 */
347	qsort(ntp_keywords, COUNTOF(ntp_keywords),
348	      sizeof(ntp_keywords[0]), compare_key_tok_text);
349
350	/*
351	 * To save space, reserve the state array entry matching each
352	 * token number for its terminal state, so the token identifier
353	 * does not need to be stored in each state, but can be
354	 * recovered trivially.  To mark the entry reserved,
355	 * finishes_token is nonzero.
356	 */
357
358	for (i = 0; i < COUNTOF(ntp_keywords); i++) {
359		token = ntp_keywords[i].token;
360		if (1 > token || token >= COUNTOF(sst)) {
361			fprintf(stderr,
362				"keyword-gen sst[%u] too small "
363				"for keyword '%s' id %d\n",
364				(int)COUNTOF(sst),
365				ntp_keywords[i].key,
366				token);
367			exit(4);
368		}
369		sst[token].finishes_token = token;
370	}
371
372	initial_state = create_keyword_scanner();
373
374	fprintf(stderr,
375		"%d keywords consumed %d states of %d max.\n",
376		(int)COUNTOF(ntp_keywords),
377		sst_highwater - 1,
378		(int)COUNTOF(sst) - 1);
379
380	printf("#define SCANNER_INIT_S %d\n\n", initial_state);
381
382	printf("const scan_state sst[%d] = {\n"
383	       "/*SS_T( ch,\tf-by, match, other ),\t\t\t\t */\n"
384	       "  0,\t\t\t\t      /* %5d %-17s */\n",
385	       sst_highwater,
386	       0, "");
387
388	for (i = 1; i < sst_highwater; i++) {
389
390		/* verify fields will fit */
391		if (sst[i].followedby & ~0x3) {
392			fprintf(stderr,
393				"keyword-gen internal error "
394				"sst[%d].followedby %d too big\n",
395				i, sst[i].followedby);
396			exit(7);
397		}
398
399		if (sst_highwater <= sst[i].match_next_s
400		    || sst[i].match_next_s & ~0x7ff) {
401			fprintf(stderr,
402				"keyword-gen internal error "
403				"sst[%d].match_next_s %d too big\n",
404				i, sst[i].match_next_s);
405			exit(8);
406		}
407
408		if (sst_highwater <= sst[i].other_next_s
409		    || sst[i].other_next_s & ~0x7ff) {
410			fprintf(stderr,
411				"keyword-gen internal error "
412				"sst[%d].other_next_s %d too big\n",
413				i, sst[i].other_next_s);
414			exit(9);
415		}
416
417		if (sst[i].finishes_token) {
418			snprintf(token_id_comment,
419				 sizeof(token_id_comment), "%5d %-17s",
420				 i, symbname(sst[i].finishes_token));
421			if (i != sst[i].finishes_token) {
422				fprintf(stderr,
423					"keyword-gen internal error "
424					"entry %d finishes token %d\n",
425					i, sst[i].finishes_token);
426				exit(5);
427			}
428		} else {
429		/*
430		 * Determine the keyword prefix that leads to this
431		 * state.  This is expensive but keyword-gen is run
432		 * only when it changes.  Distributing keyword-gen-utd
433		 * achieves that, which is why it must be committed
434		 * at the same time as keyword-gen.c and ntp_keyword.h.
435		 *
436		 * Scan the state array iteratively looking for a state
437		 * which leads to the current one, collecting matching
438		 * characters along the way.  There is only one such
439		 * path back to the starting state given the way our
440		 * scanner state machine is built and the practice of
441		 * using the spelling of the keyword as its T_* token
442		 * identifier, which results in never having two
443		 * spellings result in the same T_* value.
444		 */
445			prefix_len = 0;
446			this_state = i;
447			do {
448				for (state = 1; state < sst_highwater; state++)
449					if (sst[state].other_next_s == this_state) {
450						this_state = state;
451						break;
452					} else if (sst[state].match_next_s == this_state) {
453						this_state = state;
454						rprefix[prefix_len] = sst[state].ch;
455						prefix_len++;
456						break;
457					}
458			} while (this_state != initial_state);
459
460			if (prefix_len) {
461				/* reverse rprefix into prefix */
462				p = prefix + prefix_len;
463				r = rprefix;
464				while (r < rprefix + prefix_len)
465					*--p = *r++;
466			}
467			prefix[prefix_len] = '\0';
468
469			snprintf(token_id_comment,
470				 sizeof(token_id_comment), "%5d %-17s",
471				 i, (initial_state == i)
472					? "[initial state]"
473					: prefix);
474		}
475
476		printf("  S_ST( '%c',\t%d,    %5u, %5u )%s /* %s */\n",
477		       sst[i].ch,
478		       sst[i].followedby,
479		       sst[i].match_next_s,
480		       sst[i].other_next_s,
481		       (i + 1 < sst_highwater)
482			   ? ","
483			   : " ",
484		       token_id_comment);
485	}
486
487	printf("};\n\n");
488}
489
490
491/* Define a function to create the states of the scanner. This function
492 * is used by the create_keyword_scanner function below.
493 *
494 * This function takes a suffix of a keyword, the token to be returned on
495 * recognizing the complete keyword, and any pre-existing state that exists
496 * for some other keyword that has the same prefix as the current one.
497 */
498static u_short
499create_scan_states(
500	char *	text,
501	u_short	token,
502	follby	followedby,
503	u_short	prev_state
504	)
505{
506	u_short my_state;
507	u_short return_state;
508	u_short prev_char_s;
509	u_short curr_char_s;
510
511	return_state = prev_state;
512	curr_char_s = prev_state;
513	prev_char_s = 0;
514
515	/* Find the correct position to insert the state.
516	 * All states should be in alphabetical order
517	 */
518	while (curr_char_s && (text[0] < sst[curr_char_s].ch)) {
519		prev_char_s = curr_char_s;
520		curr_char_s = sst[curr_char_s].other_next_s;
521	}
522
523	/*
524	 * Check if a previously seen keyword has the same prefix as
525	 * the current keyword.  If so, simply use the state for that
526	 * keyword as my_state, otherwise, allocate a new state.
527	 */
528	if (curr_char_s && (text[0] == sst[curr_char_s].ch)) {
529		my_state = curr_char_s;
530		if ('\0' == text[1]) {
531			fprintf(stderr,
532				"Duplicate entries for keyword '%s' in"
533				" keyword_gen.c ntp_keywords[].\n",
534				current_keyword);
535			exit(2);
536		}
537	} else {
538		do
539			my_state = sst_highwater++;
540		while (my_state < COUNTOF(sst)
541		       && sst[my_state].finishes_token);
542		if (my_state >= COUNTOF(sst)) {
543			fprintf(stderr,
544				"fatal, keyword scanner state array "
545				"sst[%d] is too small, modify\n"
546				"keyword-gen.c to increase.\n",
547				(int)COUNTOF(sst));
548			exit(3);
549		}
550		/* Store the next character of the keyword */
551		sst[my_state].ch = text[0];
552		sst[my_state].other_next_s = curr_char_s;
553		sst[my_state].followedby = FOLLBY_NON_ACCEPTING;
554
555		if (prev_char_s)
556			sst[prev_char_s].other_next_s = my_state;
557		else
558			return_state = my_state;
559	}
560
561	/* Check if the next character is '\0'.
562	 * If yes, we are done with the recognition and this is an accepting
563	 * state.
564	 * If not, we need to continue scanning
565	 */
566	if ('\0' == text[1]) {
567		sst[my_state].finishes_token = (u_short)token;
568		sst[my_state].followedby = (char)followedby;
569
570		if (sst[token].finishes_token != (u_short)token) {
571			fprintf(stderr,
572				"fatal, sst[%d] not reserved for %s.\n",
573				token, symbname(token));
574			exit(6);
575		}
576		/* relocate so token id is sst[] index */
577		if (my_state != token) {
578			sst[token] = sst[my_state];
579			ZERO(sst[my_state]);
580			do
581				sst_highwater--;
582			while (sst[sst_highwater].finishes_token);
583			my_state = token;
584			if (prev_char_s)
585				sst[prev_char_s].other_next_s = my_state;
586			else
587				return_state = my_state;
588		}
589	} else
590		sst[my_state].match_next_s =
591		    create_scan_states(
592			&text[1],
593			token,
594			followedby,
595			sst[my_state].match_next_s);
596
597	return return_state;
598}
599
600
601/* Define a function that takes a list of (keyword, token) values and
602 * creates a keywords scanner out of it.
603 */
604
605static u_short
606create_keyword_scanner(void)
607{
608	u_short scanner;
609	u_short i;
610
611	sst_highwater = 1;	/* index 0 invalid, unused */
612	scanner = 0;
613
614	for (i = 0; i < COUNTOF(ntp_keywords); i++) {
615		current_keyword = ntp_keywords[i].key;
616		scanner =
617		    create_scan_states(
618			ntp_keywords[i].key,
619			ntp_keywords[i].token,
620			ntp_keywords[i].followedby,
621			scanner);
622	}
623
624	return scanner;
625}
626
627
628static void
629generate_token_text(void)
630{
631	u_short lowest_id;
632	u_short highest_id;
633	u_short id_count;
634	u_short id;
635	u_short i;
636
637	/* sort ntp_keywords in token ID order */
638	qsort(ntp_keywords, COUNTOF(ntp_keywords),
639	      sizeof(ntp_keywords[0]), compare_key_tok_id);
640
641	lowest_id = ntp_keywords[0].token;
642	highest_id = ntp_keywords[COUNTOF(ntp_keywords) - 1].token;
643	id_count = highest_id - lowest_id + 1;
644
645	printf("#define LOWEST_KEYWORD_ID %d\n\n", lowest_id);
646
647	printf("const char * const keyword_text[%d] = {", id_count);
648
649	id = lowest_id;
650	i = 0;
651	while (i < COUNTOF(ntp_keywords)) {
652		while (id < ntp_keywords[i].token) {
653			printf(",\n\t/* %-5d %5d %20s */\tNULL",
654			       id - lowest_id, id, symbname(id));
655			id++;
656		}
657		if (i > 0)
658			printf(",");
659		printf("\n\t/* %-5d %5d %20s */\t\"%s\"",
660		       id - lowest_id, id, symbname(id),
661		       ntp_keywords[i].key);
662		i++;
663		id++;
664	}
665
666	printf("\n};\n\n");
667}
668
669
670int
671compare_key_tok_id(
672	const void *a1,
673	const void *a2
674	)
675{
676	const struct key_tok *p1 = a1;
677	const struct key_tok *p2 = a2;
678
679	if (p1->token == p2->token)
680		return 0;
681
682	if (p1->token < p2->token)
683		return -1;
684	else
685		return 1;
686}
687
688
689int
690compare_key_tok_text(
691	const void *a1,
692	const void *a2
693	)
694{
695	const struct key_tok *p1 = a1;
696	const struct key_tok *p2 = a2;
697
698	return strcmp(p1->key, p2->key);
699}
700
701
702/*
703 * populate_symb() - populate symb[] lookup array with symbolic token
704 *		     names such that symb[T_Age] == "T_Age", etc.
705 */
706void
707populate_symb(
708	char *header_file
709	)
710{
711	FILE *	yh;
712	char	line[2 * MAX_TOK_LEN];
713	char	name[2 * MAX_TOK_LEN];
714	int	token;
715
716	yh = fopen(header_file, "r");
717	if (NULL == yh) {
718		perror("unable to open yacc/bison header file");
719		exit(4);
720	}
721
722	while (NULL != fgets(line, sizeof(line), yh))
723		if (2 == sscanf(line, "#define %s %d", name, &token)
724		    && 'T' == name[0] && '_' == name[1] && token >= 0
725		    && token < COUNTOF(symb)) {
726
727			symb[token] = estrdup(name);
728			if (strlen(name) > MAX_TOK_LEN) {
729				fprintf(stderr,
730					"MAX_TOK_LEN %d too small for '%s'\n"
731					"Edit keyword-gen.c to raise.\n",
732					MAX_TOK_LEN, name);
733				exit(10);
734			}
735		}
736	fclose(yh);
737}
738
739
740const char *
741symbname(
742	u_short token
743	)
744{
745	char *name;
746
747	if (token < COUNTOF(symb) && symb[token] != NULL) {
748		name = symb[token];
749	} else {
750		LIB_GETBUF(name);
751		snprintf(name, LIB_BUFLENGTH, "%d", token);
752	}
753
754	return name;
755}
756