Annotation of src/usr.bin/gprof/dfn.c, Revision 1.3
1.3 ! mickey 1: /* $OpenBSD: dfn.c,v 1.2 1996/06/26 05:33:49 deraadt Exp $ */
1.1 deraadt 2: /* $NetBSD: dfn.c,v 1.5 1995/04/19 07:15:56 cgd Exp $ */
3:
4: /*
5: * Copyright (c) 1983, 1993
6: * The Regents of the University of California. All rights reserved.
7: *
8: * Redistribution and use in source and binary forms, with or without
9: * modification, are permitted provided that the following conditions
10: * are met:
11: * 1. Redistributions of source code must retain the above copyright
12: * notice, this list of conditions and the following disclaimer.
13: * 2. Redistributions in binary form must reproduce the above copyright
14: * notice, this list of conditions and the following disclaimer in the
15: * documentation and/or other materials provided with the distribution.
16: * 3. All advertising materials mentioning features or use of this software
17: * must display the following acknowledgement:
18: * This product includes software developed by the University of
19: * California, Berkeley and its contributors.
20: * 4. Neither the name of the University nor the names of its contributors
21: * may be used to endorse or promote products derived from this software
22: * without specific prior written permission.
23: *
24: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34: * SUCH DAMAGE.
35: */
36:
37: #ifndef lint
38: #if 0
39: static char sccsid[] = "@(#)dfn.c 8.1 (Berkeley) 6/6/93";
40: #else
1.3 ! mickey 41: static char rcsid[] = "$OpenBSD: dfn.c,v 1.2 1996/06/26 05:33:49 deraadt Exp $";
1.1 deraadt 42: #endif
43: #endif /* not lint */
44:
45: #include <stdio.h>
46: #include "gprof.h"
47:
48: #define DFN_DEPTH 100
49: struct dfnstruct {
50: nltype *nlentryp;
51: int cycletop;
52: };
53: typedef struct dfnstruct dfntype;
54:
55: dfntype dfn_stack[ DFN_DEPTH ];
56: int dfn_depth;
57:
58: int dfn_counter;
59:
1.3 ! mickey 60: void
1.1 deraadt 61: dfn_init()
62: {
63:
64: dfn_depth = 0;
65: dfn_counter = DFN_NAN;
66: }
67:
68: /*
69: * given this parent, depth first number its children.
70: */
1.3 ! mickey 71: void
1.1 deraadt 72: dfn( parentp )
73: nltype *parentp;
74: {
75: arctype *arcp;
76:
77: # ifdef DEBUG
78: if ( debug & DFNDEBUG ) {
79: printf( "[dfn] dfn(" );
80: printname( parentp );
81: printf( ")\n" );
82: }
83: # endif DEBUG
84: /*
85: * if we're already numbered, no need to look any furthur.
86: */
87: if ( dfn_numbered( parentp ) ) {
88: return;
89: }
90: /*
91: * if we're already busy, must be a cycle
92: */
93: if ( dfn_busy( parentp ) ) {
94: dfn_findcycle( parentp );
95: return;
96: }
97: /*
98: * visit yourself before your children
99: */
100: dfn_pre_visit( parentp );
101: /*
102: * visit children
103: */
104: for ( arcp = parentp -> children ; arcp ; arcp = arcp -> arc_childlist ) {
105: if ( arcp -> arc_flags & DEADARC )
106: continue;
107: dfn( arcp -> arc_childp );
108: }
109: /*
110: * visit yourself after your children
111: */
112: dfn_post_visit( parentp );
113: }
114:
115: /*
116: * push a parent onto the stack and mark it busy
117: */
1.3 ! mickey 118: void
1.1 deraadt 119: dfn_pre_visit( parentp )
120: nltype *parentp;
121: {
122:
123: dfn_depth += 1;
1.3 ! mickey 124: if ( dfn_depth >= DFN_DEPTH )
! 125: errx(1, "[dfn] out of my depth (dfn_stack overflow)" );
1.1 deraadt 126: dfn_stack[ dfn_depth ].nlentryp = parentp;
127: dfn_stack[ dfn_depth ].cycletop = dfn_depth;
128: parentp -> toporder = DFN_BUSY;
129: # ifdef DEBUG
130: if ( debug & DFNDEBUG ) {
131: printf( "[dfn_pre_visit]\t\t%d:" , dfn_depth );
132: printname( parentp );
133: printf( "\n" );
134: }
135: # endif DEBUG
136: }
137:
138: /*
139: * are we already numbered?
140: */
141: bool
142: dfn_numbered( childp )
143: nltype *childp;
144: {
145:
146: return ( childp -> toporder != DFN_NAN && childp -> toporder != DFN_BUSY );
147: }
148:
149: /*
150: * are we already busy?
151: */
152: bool
153: dfn_busy( childp )
154: nltype *childp;
155: {
156:
157: if ( childp -> toporder == DFN_NAN ) {
158: return FALSE;
159: }
160: return TRUE;
161: }
162:
163: /*
164: * MISSING: an explanation
165: */
1.3 ! mickey 166: void
1.1 deraadt 167: dfn_findcycle( childp )
168: nltype *childp;
169: {
170: int cycletop;
171: nltype *cycleheadp;
172: nltype *tailp;
173: int index;
174:
175: for ( cycletop = dfn_depth ; cycletop > 0 ; cycletop -= 1 ) {
176: cycleheadp = dfn_stack[ cycletop ].nlentryp;
177: if ( childp == cycleheadp ) {
178: break;
179: }
180: if ( childp -> cyclehead != childp &&
181: childp -> cyclehead == cycleheadp ) {
182: break;
183: }
184: }
1.3 ! mickey 185: if ( cycletop <= 0 )
! 186: errx( 1, "[dfn_findcycle] couldn't find head of cycle");
1.1 deraadt 187: # ifdef DEBUG
188: if ( debug & DFNDEBUG ) {
189: printf( "[dfn_findcycle] dfn_depth %d cycletop %d " ,
190: dfn_depth , cycletop );
191: printname( cycleheadp );
192: printf( "\n" );
193: }
194: # endif DEBUG
195: if ( cycletop == dfn_depth ) {
196: /*
197: * this is previous function, e.g. this calls itself
198: * sort of boring
199: */
200: dfn_self_cycle( childp );
201: } else {
202: /*
203: * glom intervening functions that aren't already
204: * glommed into this cycle.
205: * things have been glommed when their cyclehead field
206: * points to the head of the cycle they are glommed into.
207: */
208: for ( tailp = cycleheadp ; tailp -> cnext ; tailp = tailp -> cnext ) {
209: /* void: chase down to tail of things already glommed */
210: # ifdef DEBUG
211: if ( debug & DFNDEBUG ) {
212: printf( "[dfn_findcycle] tail " );
213: printname( tailp );
214: printf( "\n" );
215: }
216: # endif DEBUG
217: }
218: /*
219: * if what we think is the top of the cycle
220: * has a cyclehead field, then it's not really the
221: * head of the cycle, which is really what we want
222: */
223: if ( cycleheadp -> cyclehead != cycleheadp ) {
224: cycleheadp = cycleheadp -> cyclehead;
225: # ifdef DEBUG
226: if ( debug & DFNDEBUG ) {
227: printf( "[dfn_findcycle] new cyclehead " );
228: printname( cycleheadp );
229: printf( "\n" );
230: }
231: # endif DEBUG
232: }
233: for ( index = cycletop + 1 ; index <= dfn_depth ; index += 1 ) {
234: childp = dfn_stack[ index ].nlentryp;
235: if ( childp -> cyclehead == childp ) {
236: /*
237: * not yet glommed anywhere, glom it
238: * and fix any children it has glommed
239: */
240: tailp -> cnext = childp;
241: childp -> cyclehead = cycleheadp;
242: # ifdef DEBUG
243: if ( debug & DFNDEBUG ) {
244: printf( "[dfn_findcycle] glomming " );
245: printname( childp );
246: printf( " onto " );
247: printname( cycleheadp );
248: printf( "\n" );
249: }
250: # endif DEBUG
251: for ( tailp = childp ; tailp->cnext ; tailp = tailp->cnext ) {
252: tailp -> cnext -> cyclehead = cycleheadp;
253: # ifdef DEBUG
254: if ( debug & DFNDEBUG ) {
255: printf( "[dfn_findcycle] and its tail " );
256: printname( tailp -> cnext );
257: printf( " onto " );
258: printname( cycleheadp );
259: printf( "\n" );
260: }
261: # endif DEBUG
262: }
1.3 ! mickey 263: } else if ( childp -> cyclehead != cycleheadp /* firewall */ )
! 264: warnx("[dfn_busy] glommed, but not to cyclehead");
1.1 deraadt 265: }
266: }
267: }
268:
269: /*
270: * deal with self-cycles
271: * for lint: ARGSUSED
272: */
1.3 ! mickey 273: void
1.1 deraadt 274: dfn_self_cycle( parentp )
275: nltype *parentp;
276: {
277: /*
278: * since we are taking out self-cycles elsewhere
279: * no need for the special case, here.
280: */
281: # ifdef DEBUG
282: if ( debug & DFNDEBUG ) {
283: printf( "[dfn_self_cycle] " );
284: printname( parentp );
285: printf( "\n" );
286: }
287: # endif DEBUG
288: }
289:
290: /*
291: * visit a node after all its children
292: * [MISSING: an explanation]
293: * and pop it off the stack
294: */
1.3 ! mickey 295: void
1.1 deraadt 296: dfn_post_visit( parentp )
297: nltype *parentp;
298: {
299: nltype *memberp;
300:
301: # ifdef DEBUG
302: if ( debug & DFNDEBUG ) {
303: printf( "[dfn_post_visit]\t%d: " , dfn_depth );
304: printname( parentp );
305: printf( "\n" );
306: }
307: # endif DEBUG
308: /*
309: * number functions and things in their cycles
310: * unless the function is itself part of a cycle
311: */
312: if ( parentp -> cyclehead == parentp ) {
313: dfn_counter += 1;
314: for ( memberp = parentp ; memberp ; memberp = memberp -> cnext ) {
315: memberp -> toporder = dfn_counter;
316: # ifdef DEBUG
317: if ( debug & DFNDEBUG ) {
318: printf( "[dfn_post_visit]\t\tmember " );
319: printname( memberp );
320: printf( " -> toporder = %d\n" , dfn_counter );
321: }
322: # endif DEBUG
323: }
324: } else {
325: # ifdef DEBUG
326: if ( debug & DFNDEBUG ) {
327: printf( "[dfn_post_visit]\t\tis part of a cycle\n" );
328: }
329: # endif DEBUG
330: }
331: dfn_depth -= 1;
332: }
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