xref: /freebsd/sys/dev/aic7xxx/aicasm/aicasm.c (revision 17d6c636720d00f77e5d098daf4c278f89d84f7b)
1 /*
2  * Aic7xxx SCSI host adapter firmware asssembler
3  *
4  * Copyright (c) 1997, 1998, 2000 Justin T. Gibbs.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions, and the following disclaimer,
12  *    without modification, immediately at the beginning of the file.
13  * 2. The name of the author may not be used to endorse or promote products
14  *    derived from this software without specific prior written permission.
15  *
16  * Alternatively, this software may be distributed under the terms of the
17  * GNU Public License ("GPL").
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
23  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  * $Id: //depot/src/aic7xxx/aicasm/aicasm.c#8 $
32  *
33  * $FreeBSD$
34  */
35 #include <sys/types.h>
36 #include <sys/mman.h>
37 
38 #include <ctype.h>
39 #include <inttypes.h>
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <string.h>
43 #include <sysexits.h>
44 #include <unistd.h>
45 
46 #include "aicasm.h"
47 #include "aicasm_symbol.h"
48 #include "aicasm_insformat.h"
49 
50 typedef struct patch {
51 	STAILQ_ENTRY(patch) links;
52 	int		patch_func;
53 	u_int		begin;
54 	u_int		skip_instr;
55 	u_int		skip_patch;
56 } patch_t;
57 
58 STAILQ_HEAD(patch_list, patch) patches;
59 
60 static void usage(void);
61 static void back_patch(void);
62 static void output_code(void);
63 static void output_listing(char *ifilename);
64 static void dump_scope(scope_t *scope);
65 static void emit_patch(scope_t *scope, int patch);
66 static int check_patch(patch_t **start_patch, int start_instr,
67 		       int *skip_addr, int *func_vals);
68 
69 struct path_list search_path;
70 int includes_search_curdir;
71 char *appname;
72 FILE *ofile;
73 char *ofilename;
74 char *regfilename;
75 FILE *regfile;
76 char *listfilename;
77 FILE *listfile;
78 
79 static STAILQ_HEAD(,instruction) seq_program;
80 struct cs_tailq cs_tailq;
81 struct scope_list scope_stack;
82 symlist_t patch_functions;
83 
84 #if DEBUG
85 extern int yy_flex_debug;
86 extern int yydebug;
87 #endif
88 extern FILE *yyin;
89 extern int yyparse(void);
90 
91 int main(int argc, char *argv[]);
92 
93 int
94 main(int argc, char *argv[])
95 {
96 	extern char *optarg;
97 	extern int optind;
98 	int  ch;
99 	int  retval;
100 	char *inputfilename;
101 	scope_t *sentinal;
102 
103 	STAILQ_INIT(&patches);
104 	SLIST_INIT(&search_path);
105 	STAILQ_INIT(&seq_program);
106 	TAILQ_INIT(&cs_tailq);
107 	SLIST_INIT(&scope_stack);
108 
109 	/* Set Sentinal scope node */
110 	sentinal = scope_alloc();
111 	sentinal->type = SCOPE_ROOT;
112 
113 	includes_search_curdir = 1;
114 	appname = *argv;
115 	regfile = NULL;
116 	listfile = NULL;
117 #if DEBUG
118 	yy_flex_debug = 0;
119 	yydebug = 0;
120 #endif
121 	while ((ch = getopt(argc, argv, "d:l:n:o:r:I:O:")) != -1) {
122 		switch(ch) {
123 		case 'd':
124 #if DEBUG
125 			if (strcmp(optarg, "s") == 0) {
126 				yy_flex_debug = 1;
127 			} else if (strcmp(optarg, "p") == 0) {
128 				yydebug = 1;
129 			} else {
130 				fprintf(stderr, "%s: -d Requires either an "
131 					"'s' or 'p' argument\n", appname);
132 				usage();
133 			}
134 #else
135 			stop("-d: Assembler not built with debugging "
136 			     "information", EX_SOFTWARE);
137 #endif
138 			break;
139 		case 'l':
140 			/* Create a program listing */
141 			if ((listfile = fopen(optarg, "w")) == NULL) {
142 				perror(optarg);
143 				stop(NULL, EX_CANTCREAT);
144 			}
145 			listfilename = optarg;
146 			break;
147 		case 'n':
148 			/* Don't complain about the -nostdinc directrive */
149 			if (strcmp(optarg, "ostdinc")) {
150 				fprintf(stderr, "%s: Unknown option -%c%s\n",
151 					appname, ch, optarg);
152 				usage();
153 				/* NOTREACHED */
154 			}
155 			break;
156 		case 'o':
157 			if ((ofile = fopen(optarg, "w")) == NULL) {
158 				perror(optarg);
159 				stop(NULL, EX_CANTCREAT);
160 			}
161 			ofilename = optarg;
162 			break;
163 		case 'r':
164 			if ((regfile = fopen(optarg, "w")) == NULL) {
165 				perror(optarg);
166 				stop(NULL, EX_CANTCREAT);
167 			}
168 			regfilename = optarg;
169 			break;
170 		case 'I':
171 		{
172 			path_entry_t include_dir;
173 
174 			if (strcmp(optarg, "-") == 0) {
175 				if (includes_search_curdir == 0) {
176 					fprintf(stderr, "%s: Warning - '-I-' "
177 							"specified multiple "
178 							"times\n", appname);
179 				}
180 				includes_search_curdir = 0;
181 				for (include_dir = SLIST_FIRST(&search_path);
182 				     include_dir != NULL;
183 				     include_dir = SLIST_NEXT(include_dir,
184 							      links))
185 					/*
186 					 * All entries before a '-I-' only
187 					 * apply to includes specified with
188 					 * quotes instead of "<>".
189 					 */
190 					include_dir->quoted_includes_only = 1;
191 			} else {
192 				include_dir =
193 				    (path_entry_t)malloc(sizeof(*include_dir));
194 				if (include_dir == NULL) {
195 					perror(optarg);
196 					stop(NULL, EX_OSERR);
197 				}
198 				include_dir->directory = strdup(optarg);
199 				if (include_dir->directory == NULL) {
200 					perror(optarg);
201 					stop(NULL, EX_OSERR);
202 				}
203 				include_dir->quoted_includes_only = 0;
204 				SLIST_INSERT_HEAD(&search_path, include_dir,
205 						  links);
206 			}
207 			break;
208 		}
209 		case '?':
210 		default:
211 			usage();
212 			/* NOTREACHED */
213 		}
214 	}
215 	argc -= optind;
216 	argv += optind;
217 
218 	if (argc != 1) {
219 		fprintf(stderr, "%s: No input file specifiled\n", appname);
220 		usage();
221 		/* NOTREACHED */
222 	}
223 
224 	symtable_open();
225 	inputfilename = *argv;
226 	include_file(*argv, SOURCE_FILE);
227 	retval = yyparse();
228 	if (retval == 0) {
229 		if (SLIST_FIRST(&scope_stack) == NULL
230 		 || SLIST_FIRST(&scope_stack)->type != SCOPE_ROOT) {
231 			stop("Unterminated conditional expression",
232 			     EX_DATAERR);
233 			/* NOTREACHED */
234 		}
235 
236 		/* Process outmost scope */
237 		process_scope(SLIST_FIRST(&scope_stack));
238 		/*
239 		 * Decend the tree of scopes and insert/emit
240 		 * patches as appropriate.  We perform a depth first
241 		 * tranversal, recursively handling each scope.
242 		 */
243 		/* start at the root scope */
244 		dump_scope(SLIST_FIRST(&scope_stack));
245 
246 		/* Patch up forward jump addresses */
247 		back_patch();
248 
249 		if (ofile != NULL)
250 			output_code();
251 		if (regfile != NULL) {
252 			symtable_dump(regfile);
253 		}
254 		if (listfile != NULL)
255 			output_listing(inputfilename);
256 	}
257 
258 	stop(NULL, 0);
259 	/* NOTREACHED */
260 	return (0);
261 }
262 
263 static void
264 usage()
265 {
266 
267 	(void)fprintf(stderr,
268 "usage: %-16s [-nostdinc] [-I-] [-I directory] [-o output_file]
269 			[-r register_output_file] [-l program_list_file]
270 			input_file\n",
271 			appname);
272 	exit(EX_USAGE);
273 }
274 
275 static void
276 back_patch()
277 {
278 	struct instruction *cur_instr;
279 
280 	for (cur_instr = STAILQ_FIRST(&seq_program);
281 	     cur_instr != NULL;
282 	     cur_instr = STAILQ_NEXT(cur_instr, links)) {
283 		if (cur_instr->patch_label != NULL) {
284 			struct ins_format3 *f3_instr;
285 			u_int address;
286 
287 			if (cur_instr->patch_label->type != LABEL) {
288 				char buf[255];
289 
290 				snprintf(buf, sizeof(buf),
291 					 "Undefined label %s",
292 					 cur_instr->patch_label->name);
293 				stop(buf, EX_DATAERR);
294 				/* NOTREACHED */
295 			}
296 			f3_instr = &cur_instr->format.format3;
297 			address = f3_instr->address;
298 			address += cur_instr->patch_label->info.linfo->address;
299 			f3_instr->address = address;
300 		}
301 	}
302 }
303 
304 static void
305 output_code()
306 {
307 	struct instruction *cur_instr;
308 	patch_t *cur_patch;
309 	critical_section_t *cs;
310 	symbol_node_t *cur_node;
311 	int instrcount;
312 
313 	instrcount = 0;
314 	fprintf(ofile,
315 "/*
316  * DO NOT EDIT - This file is automatically generated
317  *		 from the following source files:
318  *
319 %s */\n", versions);
320 
321 	fprintf(ofile, "static uint8_t seqprog[] = {\n");
322 	for (cur_instr = STAILQ_FIRST(&seq_program);
323 	     cur_instr != NULL;
324 	     cur_instr = STAILQ_NEXT(cur_instr, links)) {
325 
326 		fprintf(ofile, "%s\t0x%02x, 0x%02x, 0x%02x, 0x%02x",
327 			cur_instr == STAILQ_FIRST(&seq_program) ? "" : ",\n",
328 #if BYTE_ORDER == LITTLE_ENDIAN
329 			cur_instr->format.bytes[0],
330 			cur_instr->format.bytes[1],
331 			cur_instr->format.bytes[2],
332 			cur_instr->format.bytes[3]);
333 #else
334 			cur_instr->format.bytes[3],
335 			cur_instr->format.bytes[2],
336 			cur_instr->format.bytes[1],
337 			cur_instr->format.bytes[0]);
338 #endif
339 		instrcount++;
340 	}
341 	fprintf(ofile, "\n};\n\n");
342 
343 	/*
344 	 *  Output patch information.  Patch functions first.
345 	 */
346 	for (cur_node = SLIST_FIRST(&patch_functions);
347 	     cur_node != NULL;
348 	     cur_node = SLIST_NEXT(cur_node,links)) {
349 		fprintf(ofile,
350 "static int ahc_patch%d_func(struct ahc_softc *ahc);
351 
352 static int
353 ahc_patch%d_func(struct ahc_softc *ahc)
354 {
355 	return (%s);
356 }\n\n",
357 			cur_node->symbol->info.condinfo->func_num,
358 			cur_node->symbol->info.condinfo->func_num,
359 			cur_node->symbol->name);
360 	}
361 
362 	fprintf(ofile,
363 "typedef int patch_func_t (struct ahc_softc *);
364 struct patch {
365 	patch_func_t	*patch_func;
366 	uint32_t	begin	   :10,
367 			skip_instr :10,
368 			skip_patch :12;
369 } patches[] = {\n");
370 
371 	for(cur_patch = STAILQ_FIRST(&patches);
372 	    cur_patch != NULL;
373 	    cur_patch = STAILQ_NEXT(cur_patch,links)) {
374 		fprintf(ofile, "%s\t{ ahc_patch%d_func, %d, %d, %d }",
375 			cur_patch == STAILQ_FIRST(&patches) ? "" : ",\n",
376 			cur_patch->patch_func, cur_patch->begin,
377 			cur_patch->skip_instr, cur_patch->skip_patch);
378 	}
379 
380 	fprintf(ofile, "\n};\n");
381 
382 	fprintf(ofile,
383 "struct cs {
384 	u_int16_t	begin;
385 	u_int16_t	end;
386 } critical_sections[] = {\n");
387 
388 	for(cs = TAILQ_FIRST(&cs_tailq);
389 	    cs != NULL;
390 	    cs = TAILQ_NEXT(cs, links)) {
391 		fprintf(ofile, "%s\t{ %d, %d }",
392 			cs == TAILQ_FIRST(&cs_tailq) ? "" : ",\n",
393 			cs->begin_addr, cs->end_addr);
394 	}
395 
396 	fprintf(ofile, "\n};\n");
397 
398 	fprintf(ofile,
399 "const int num_critical_sections = sizeof(critical_sections)
400 				 / sizeof(*critical_sections);\n");
401 
402 	fprintf(stderr, "%s: %d instructions used\n", appname, instrcount);
403 }
404 
405 static void
406 dump_scope(scope_t *scope)
407 {
408 	scope_t *cur_scope;
409 
410 	/*
411 	 * Emit the first patch for this scope
412 	 */
413 	emit_patch(scope, 0);
414 
415 	/*
416 	 * Dump each scope within this one.
417 	 */
418 	cur_scope = TAILQ_FIRST(&scope->inner_scope);
419 
420 	while (cur_scope != NULL) {
421 
422 		dump_scope(cur_scope);
423 
424 		cur_scope = TAILQ_NEXT(cur_scope, scope_links);
425 	}
426 
427 	/*
428 	 * Emit the second, closing, patch for this scope
429 	 */
430 	emit_patch(scope, 1);
431 }
432 
433 void
434 emit_patch(scope_t *scope, int patch)
435 {
436 	patch_info_t *pinfo;
437 	patch_t *new_patch;
438 
439 	pinfo = &scope->patches[patch];
440 
441 	if (pinfo->skip_instr == 0)
442 		/* No-Op patch */
443 		return;
444 
445 	new_patch = (patch_t *)malloc(sizeof(*new_patch));
446 
447 	if (new_patch == NULL)
448 		stop("Could not malloc patch structure", EX_OSERR);
449 
450 	memset(new_patch, 0, sizeof(*new_patch));
451 
452 	if (patch == 0) {
453 		new_patch->patch_func = scope->func_num;
454 		new_patch->begin = scope->begin_addr;
455 	} else {
456 		new_patch->patch_func = 0;
457 		new_patch->begin = scope->end_addr;
458 	}
459 	new_patch->skip_instr = pinfo->skip_instr;
460 	new_patch->skip_patch = pinfo->skip_patch;
461 	STAILQ_INSERT_TAIL(&patches, new_patch, links);
462 }
463 
464 void
465 output_listing(char *ifilename)
466 {
467 	char buf[1024];
468 	FILE *ifile;
469 	struct instruction *cur_instr;
470 	patch_t *cur_patch;
471 	symbol_node_t *cur_func;
472 	int *func_values;
473 	int instrcount;
474 	int instrptr;
475 	int line;
476 	int func_count;
477 	int skip_addr;
478 
479 	instrcount = 0;
480 	instrptr = 0;
481 	line = 1;
482 	skip_addr = 0;
483 	if ((ifile = fopen(ifilename, "r")) == NULL) {
484 		perror(ifilename);
485 		stop(NULL, EX_DATAERR);
486 	}
487 
488 	/*
489 	 * Determine which options to apply to this listing.
490 	 */
491 	for (func_count = 0, cur_func = SLIST_FIRST(&patch_functions);
492 	    cur_func != NULL;
493 	    cur_func = SLIST_NEXT(cur_func, links))
494 		func_count++;
495 
496 	func_values = NULL;
497 	if (func_count != 0) {
498 		func_values = (int *)malloc(func_count * sizeof(int));
499 
500 		if (func_values == NULL)
501 			stop("Could not malloc", EX_OSERR);
502 
503 		func_values[0] = 0; /* FALSE func */
504 		func_count--;
505 
506 		/*
507 		 * Ask the user to fill in the return values for
508 		 * the rest of the functions.
509 		 */
510 
511 
512 		for (cur_func = SLIST_FIRST(&patch_functions);
513 		     cur_func != NULL && SLIST_NEXT(cur_func, links) != NULL;
514 		     cur_func = SLIST_NEXT(cur_func, links), func_count--) {
515 			int input;
516 
517 			fprintf(stdout, "\n(%s)\n", cur_func->symbol->name);
518 			fprintf(stdout,
519 				"Enter the return value for "
520 				"this expression[T/F]:");
521 
522 			while (1) {
523 
524 				input = getchar();
525 				input = toupper(input);
526 
527 				if (input == 'T') {
528 					func_values[func_count] = 1;
529 					break;
530 				} else if (input == 'F') {
531 					func_values[func_count] = 0;
532 					break;
533 				}
534 			}
535 			if (isatty(fileno(stdin)) == 0)
536 				putchar(input);
537 		}
538 		fprintf(stdout, "\nThanks!\n");
539 	}
540 
541 	/* Now output the listing */
542 	cur_patch = STAILQ_FIRST(&patches);
543 	for(cur_instr = STAILQ_FIRST(&seq_program);
544 	    cur_instr != NULL;
545 	    cur_instr = STAILQ_NEXT(cur_instr, links), instrcount++) {
546 
547 		if (check_patch(&cur_patch, instrcount,
548 				&skip_addr, func_values) == 0) {
549 			/* Don't count this instruction as it is in a patch
550 			 * that was removed.
551 			 */
552                         continue;
553 		}
554 
555 		while (line < cur_instr->srcline) {
556 			fgets(buf, sizeof(buf), ifile);
557 				fprintf(listfile, "\t\t%s", buf);
558 				line++;
559 		}
560 		fprintf(listfile, "%03x %02x%02x%02x%02x", instrptr,
561 #if BYTE_ORDER == LITTLE_ENDIAN
562 			cur_instr->format.bytes[0],
563 			cur_instr->format.bytes[1],
564 			cur_instr->format.bytes[2],
565 			cur_instr->format.bytes[3]);
566 #else
567 			cur_instr->format.bytes[3],
568 			cur_instr->format.bytes[2],
569 			cur_instr->format.bytes[1],
570 			cur_instr->format.bytes[0]);
571 #endif
572 		fgets(buf, sizeof(buf), ifile);
573 		fprintf(listfile, "\t%s", buf);
574 		line++;
575 		instrptr++;
576 	}
577 	/* Dump the remainder of the file */
578 	while(fgets(buf, sizeof(buf), ifile) != NULL)
579 		fprintf(listfile, "\t\t%s", buf);
580 
581 	fclose(ifile);
582 }
583 
584 static int
585 check_patch(patch_t **start_patch, int start_instr,
586 	    int *skip_addr, int *func_vals)
587 {
588 	patch_t *cur_patch;
589 
590 	cur_patch = *start_patch;
591 
592 	while (cur_patch != NULL && start_instr == cur_patch->begin) {
593 		if (func_vals[cur_patch->patch_func] == 0) {
594 			int skip;
595 
596 			/* Start rejecting code */
597 			*skip_addr = start_instr + cur_patch->skip_instr;
598 			for (skip = cur_patch->skip_patch;
599 			     skip > 0 && cur_patch != NULL;
600 			     skip--)
601 				cur_patch = STAILQ_NEXT(cur_patch, links);
602 		} else {
603 			/* Accepted this patch.  Advance to the next
604 			 * one and wait for our intruction pointer to
605 			 * hit this point.
606 			 */
607 			cur_patch = STAILQ_NEXT(cur_patch, links);
608 		}
609 	}
610 
611 	*start_patch = cur_patch;
612 	if (start_instr < *skip_addr)
613 		/* Still skipping */
614 		return (0);
615 
616 	return (1);
617 }
618 
619 /*
620  * Print out error information if appropriate, and clean up before
621  * terminating the program.
622  */
623 void
624 stop(const char *string, int err_code)
625 {
626 	if (string != NULL) {
627 		fprintf(stderr, "%s: ", appname);
628 		if (yyfilename != NULL) {
629 			fprintf(stderr, "Stopped at file %s, line %d - ",
630 				yyfilename, yylineno);
631 		}
632 		fprintf(stderr, "%s\n", string);
633 	}
634 
635 	if (ofile != NULL) {
636 		fclose(ofile);
637 		if (err_code != 0) {
638 			fprintf(stderr, "%s: Removing %s due to error\n",
639 				appname, ofilename);
640 			unlink(ofilename);
641 		}
642 	}
643 
644 	if (regfile != NULL) {
645 		fclose(regfile);
646 		if (err_code != 0) {
647 			fprintf(stderr, "%s: Removing %s due to error\n",
648 				appname, regfilename);
649 			unlink(regfilename);
650 		}
651 	}
652 
653 	if (listfile != NULL) {
654 		fclose(listfile);
655 		if (err_code != 0) {
656 			fprintf(stderr, "%s: Removing %s due to error\n",
657 				appname, listfilename);
658 			unlink(listfilename);
659 		}
660 	}
661 
662 	symlist_free(&patch_functions);
663 	symtable_close();
664 
665 	exit(err_code);
666 }
667 
668 struct instruction *
669 seq_alloc()
670 {
671 	struct instruction *new_instr;
672 
673 	new_instr = (struct instruction *)malloc(sizeof(struct instruction));
674 	if (new_instr == NULL)
675 		stop("Unable to malloc instruction object", EX_SOFTWARE);
676 	memset(new_instr, 0, sizeof(*new_instr));
677 	STAILQ_INSERT_TAIL(&seq_program, new_instr, links);
678 	new_instr->srcline = yylineno;
679 	return new_instr;
680 }
681 
682 critical_section_t *
683 cs_alloc()
684 {
685 	critical_section_t *new_cs;
686 
687 	new_cs= (critical_section_t *)malloc(sizeof(critical_section_t));
688 	if (new_cs == NULL)
689 		stop("Unable to malloc critical_section object", EX_SOFTWARE);
690 	memset(new_cs, 0, sizeof(*new_cs));
691 
692 	TAILQ_INSERT_TAIL(&cs_tailq, new_cs, links);
693 	return new_cs;
694 }
695 
696 scope_t *
697 scope_alloc()
698 {
699 	scope_t *new_scope;
700 
701 	new_scope = (scope_t *)malloc(sizeof(scope_t));
702 	if (new_scope == NULL)
703 		stop("Unable to malloc scope object", EX_SOFTWARE);
704 	memset(new_scope, 0, sizeof(*new_scope));
705 	TAILQ_INIT(&new_scope->inner_scope);
706 
707 	if (SLIST_FIRST(&scope_stack) != NULL) {
708 		TAILQ_INSERT_TAIL(&SLIST_FIRST(&scope_stack)->inner_scope,
709 				  new_scope, scope_links);
710 	}
711 	/* This patch is now the current scope */
712 	SLIST_INSERT_HEAD(&scope_stack, new_scope, scope_stack_links);
713 	return new_scope;
714 }
715 
716 void
717 process_scope(scope_t *scope)
718 {
719 	/*
720 	 * We are "leaving" this scope.  We should now have
721 	 * enough information to process the lists of scopes
722 	 * we encapsulate.
723 	 */
724 	scope_t *cur_scope;
725 	u_int skip_patch_count;
726 	u_int skip_instr_count;
727 
728 	cur_scope = TAILQ_LAST(&scope->inner_scope, scope_tailq);
729 	skip_patch_count = 0;
730 	skip_instr_count = 0;
731 	while (cur_scope != NULL) {
732 		u_int patch0_patch_skip;
733 
734 		patch0_patch_skip = 0;
735 		switch (cur_scope->type) {
736 		case SCOPE_IF:
737 		case SCOPE_ELSE_IF:
738 			if (skip_instr_count != 0) {
739 				/* Create a tail patch */
740 				patch0_patch_skip++;
741 				cur_scope->patches[1].skip_patch =
742 				    skip_patch_count + 1;
743 				cur_scope->patches[1].skip_instr =
744 				    skip_instr_count;
745 			}
746 
747 			/* Count Head patch */
748 			patch0_patch_skip++;
749 
750 			/* Count any patches contained in our inner scope */
751 			patch0_patch_skip += cur_scope->inner_scope_patches;
752 
753 			cur_scope->patches[0].skip_patch = patch0_patch_skip;
754 			cur_scope->patches[0].skip_instr =
755 			    cur_scope->end_addr - cur_scope->begin_addr;
756 
757 			skip_instr_count += cur_scope->patches[0].skip_instr;
758 
759 			skip_patch_count += patch0_patch_skip;
760 			if (cur_scope->type == SCOPE_IF) {
761 				scope->inner_scope_patches += skip_patch_count;
762 				skip_patch_count = 0;
763 			        skip_instr_count = 0;
764 			}
765 			break;
766 		case SCOPE_ELSE:
767 			/* Count any patches contained in our innter scope */
768 			skip_patch_count += cur_scope->inner_scope_patches;
769 
770 			skip_instr_count += cur_scope->end_addr
771 					  - cur_scope->begin_addr;
772 			break;
773 		case SCOPE_ROOT:
774 			stop("Unexpected scope type encountered", EX_SOFTWARE);
775 			/* NOTREACHED */
776 		}
777 
778 		cur_scope = TAILQ_PREV(cur_scope, scope_tailq, scope_links);
779 	}
780 }
781