1 /* 2 * Copyright (c) 1983, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #if 0 35 #ifndef lint 36 static char sccsid[] = "@(#)dfn.c 8.1 (Berkeley) 6/6/93"; 37 #endif /* not lint */ 38 #endif 39 40 #include <sys/cdefs.h> 41 __FBSDID("$FreeBSD$"); 42 43 #include <err.h> 44 #include "gprof.h" 45 46 #define DFN_DEPTH 100 47 struct dfnstruct { 48 nltype *nlentryp; 49 int cycletop; 50 }; 51 typedef struct dfnstruct dfntype; 52 53 dfntype dfn_stack[ DFN_DEPTH ]; 54 int dfn_depth; 55 56 int dfn_counter; 57 58 void 59 dfn_init() 60 { 61 62 dfn_depth = 0; 63 dfn_counter = DFN_NAN; 64 } 65 66 /* 67 * given this parent, depth first number its children. 68 */ 69 void 70 dfn( parentp ) 71 nltype *parentp; 72 { 73 arctype *arcp; 74 75 # ifdef DEBUG 76 if ( debug & DFNDEBUG ) { 77 printf( "[dfn] dfn(" ); 78 printname( parentp ); 79 printf( ")\n" ); 80 } 81 # endif /* DEBUG */ 82 /* 83 * if we're already numbered, no need to look any further. 84 */ 85 if ( dfn_numbered( parentp ) ) { 86 return; 87 } 88 /* 89 * if we're already busy, must be a cycle 90 */ 91 if ( dfn_busy( parentp ) ) { 92 dfn_findcycle( parentp ); 93 return; 94 } 95 /* 96 * visit yourself before your children 97 */ 98 dfn_pre_visit( parentp ); 99 /* 100 * visit children 101 */ 102 for ( arcp = parentp -> children ; arcp ; arcp = arcp -> arc_childlist ) { 103 if ( arcp -> arc_flags & DEADARC ) 104 continue; 105 dfn( arcp -> arc_childp ); 106 } 107 /* 108 * visit yourself after your children 109 */ 110 dfn_post_visit( parentp ); 111 } 112 113 /* 114 * push a parent onto the stack and mark it busy 115 */ 116 void 117 dfn_pre_visit( parentp ) 118 nltype *parentp; 119 { 120 121 dfn_depth += 1; 122 if ( dfn_depth >= DFN_DEPTH ) 123 errx( 1 , "[dfn] out of my depth (dfn_stack overflow)" ); 124 dfn_stack[ dfn_depth ].nlentryp = parentp; 125 dfn_stack[ dfn_depth ].cycletop = dfn_depth; 126 parentp -> toporder = DFN_BUSY; 127 # ifdef DEBUG 128 if ( debug & DFNDEBUG ) { 129 printf( "[dfn_pre_visit]\t\t%d:" , dfn_depth ); 130 printname( parentp ); 131 printf( "\n" ); 132 } 133 # endif /* DEBUG */ 134 } 135 136 /* 137 * are we already numbered? 138 */ 139 bool 140 dfn_numbered( childp ) 141 nltype *childp; 142 { 143 144 return ( childp -> toporder != DFN_NAN && childp -> toporder != DFN_BUSY ); 145 } 146 147 /* 148 * are we already busy? 149 */ 150 bool 151 dfn_busy( childp ) 152 nltype *childp; 153 { 154 155 if ( childp -> toporder == DFN_NAN ) { 156 return FALSE; 157 } 158 return TRUE; 159 } 160 161 /* 162 * MISSING: an explanation 163 */ 164 void 165 dfn_findcycle( childp ) 166 nltype *childp; 167 { 168 int cycletop; 169 nltype *cycleheadp; 170 nltype *tailp; 171 int index; 172 173 for ( cycletop = dfn_depth ; cycletop > 0 ; cycletop -= 1 ) { 174 cycleheadp = dfn_stack[ cycletop ].nlentryp; 175 if ( childp == cycleheadp ) { 176 break; 177 } 178 if ( childp -> cyclehead != childp && 179 childp -> cyclehead == cycleheadp ) { 180 break; 181 } 182 } 183 if ( cycletop <= 0 ) 184 errx( 1 , "[dfn_findcycle] couldn't find head of cycle" ); 185 # ifdef DEBUG 186 if ( debug & DFNDEBUG ) { 187 printf( "[dfn_findcycle] dfn_depth %d cycletop %d " , 188 dfn_depth , cycletop ); 189 printname( cycleheadp ); 190 printf( "\n" ); 191 } 192 # endif /* DEBUG */ 193 if ( cycletop == dfn_depth ) { 194 /* 195 * this is previous function, e.g. this calls itself 196 * sort of boring 197 */ 198 dfn_self_cycle( childp ); 199 } else { 200 /* 201 * glom intervening functions that aren't already 202 * glommed into this cycle. 203 * things have been glommed when their cyclehead field 204 * points to the head of the cycle they are glommed into. 205 */ 206 for ( tailp = cycleheadp ; tailp -> cnext ; tailp = tailp -> cnext ) { 207 /* void: chase down to tail of things already glommed */ 208 # ifdef DEBUG 209 if ( debug & DFNDEBUG ) { 210 printf( "[dfn_findcycle] tail " ); 211 printname( tailp ); 212 printf( "\n" ); 213 } 214 # endif /* DEBUG */ 215 } 216 /* 217 * if what we think is the top of the cycle 218 * has a cyclehead field, then it's not really the 219 * head of the cycle, which is really what we want 220 */ 221 if ( cycleheadp -> cyclehead != cycleheadp ) { 222 cycleheadp = cycleheadp -> cyclehead; 223 # ifdef DEBUG 224 if ( debug & DFNDEBUG ) { 225 printf( "[dfn_findcycle] new cyclehead " ); 226 printname( cycleheadp ); 227 printf( "\n" ); 228 } 229 # endif /* DEBUG */ 230 } 231 for ( index = cycletop + 1 ; index <= dfn_depth ; index += 1 ) { 232 childp = dfn_stack[ index ].nlentryp; 233 if ( childp -> cyclehead == childp ) { 234 /* 235 * not yet glommed anywhere, glom it 236 * and fix any children it has glommed 237 */ 238 tailp -> cnext = childp; 239 childp -> cyclehead = cycleheadp; 240 # ifdef DEBUG 241 if ( debug & DFNDEBUG ) { 242 printf( "[dfn_findcycle] glomming " ); 243 printname( childp ); 244 printf( " onto " ); 245 printname( cycleheadp ); 246 printf( "\n" ); 247 } 248 # endif /* DEBUG */ 249 for ( tailp = childp ; tailp->cnext ; tailp = tailp->cnext ) { 250 tailp -> cnext -> cyclehead = cycleheadp; 251 # ifdef DEBUG 252 if ( debug & DFNDEBUG ) { 253 printf( "[dfn_findcycle] and its tail " ); 254 printname( tailp -> cnext ); 255 printf( " onto " ); 256 printname( cycleheadp ); 257 printf( "\n" ); 258 } 259 # endif /* DEBUG */ 260 } 261 } else if ( childp -> cyclehead != cycleheadp /* firewall */ ) { 262 fprintf( stderr , 263 "[dfn_busy] glommed, but not to cyclehead\n" ); 264 } 265 } 266 } 267 } 268 269 /* 270 * deal with self-cycles 271 * for lint: ARGSUSED 272 */ 273 void 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 */ 295 void 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 } 333