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33 * @(#)dfn.c 8.1 (Berkeley) 6/6/93
35 * $DragonFly: src/usr.bin/gprof/dfn.c,v 1.4 2006/01/22 03:43:37 swildner Exp $
46 typedef struct dfnstruct dfntype;
48 dfntype dfn_stack[ DFN_DEPTH ];
57 dfn_counter = DFN_NAN;
61 * given this parent, depth first number its children.
68 if ( debug & DFNDEBUG ) {
69 printf( "[dfn] dfn(" );
75 * if we're already numbered, no need to look any furthur.
77 if ( dfn_numbered( parentp ) ) {
81 * if we're already busy, must be a cycle
83 if ( dfn_busy( parentp ) ) {
84 dfn_findcycle( parentp );
88 * visit yourself before your children
90 dfn_pre_visit( parentp );
94 for ( arcp = parentp -> children ; arcp ; arcp = arcp -> arc_childlist ) {
95 if ( arcp -> arc_flags & DEADARC )
97 dfn( arcp -> arc_childp );
100 * visit yourself after your children
102 dfn_post_visit( parentp );
106 * push a parent onto the stack and mark it busy
108 dfn_pre_visit(nltype *parentp)
112 if ( dfn_depth >= DFN_DEPTH ) {
113 fprintf( stderr , "[dfn] out of my depth (dfn_stack overflow)\n" );
116 dfn_stack[ dfn_depth ].nlentryp = parentp;
117 dfn_stack[ dfn_depth ].cycletop = dfn_depth;
118 parentp -> toporder = DFN_BUSY;
120 if ( debug & DFNDEBUG ) {
121 printf( "[dfn_pre_visit]\t\t%d:" , dfn_depth );
122 printname( parentp );
129 * are we already numbered?
132 dfn_numbered(nltype *childp)
135 return ( childp -> toporder != DFN_NAN && childp -> toporder != DFN_BUSY );
139 * are we already busy?
142 dfn_busy(nltype *childp)
145 if ( childp -> toporder == DFN_NAN ) {
152 * MISSING: an explanation
154 dfn_findcycle(nltype *childp)
161 for ( cycletop = dfn_depth ; cycletop > 0 ; cycletop -= 1 ) {
162 cycleheadp = dfn_stack[ cycletop ].nlentryp;
163 if ( childp == cycleheadp ) {
166 if ( childp -> cyclehead != childp &&
167 childp -> cyclehead == cycleheadp ) {
171 if ( cycletop <= 0 ) {
172 fprintf( stderr , "[dfn_findcycle] couldn't find head of cycle\n" );
176 if ( debug & DFNDEBUG ) {
177 printf( "[dfn_findcycle] dfn_depth %d cycletop %d " ,
178 dfn_depth , cycletop );
179 printname( cycleheadp );
183 if ( cycletop == dfn_depth ) {
185 * this is previous function, e.g. this calls itself
188 dfn_self_cycle( childp );
191 * glom intervening functions that aren't already
192 * glommed into this cycle.
193 * things have been glommed when their cyclehead field
194 * points to the head of the cycle they are glommed into.
196 for ( tailp = cycleheadp ; tailp -> cnext ; tailp = tailp -> cnext ) {
197 /* void: chase down to tail of things already glommed */
199 if ( debug & DFNDEBUG ) {
200 printf( "[dfn_findcycle] tail " );
207 * if what we think is the top of the cycle
208 * has a cyclehead field, then it's not really the
209 * head of the cycle, which is really what we want
211 if ( cycleheadp -> cyclehead != cycleheadp ) {
212 cycleheadp = cycleheadp -> cyclehead;
214 if ( debug & DFNDEBUG ) {
215 printf( "[dfn_findcycle] new cyclehead " );
216 printname( cycleheadp );
221 for ( index = cycletop + 1 ; index <= dfn_depth ; index += 1 ) {
222 childp = dfn_stack[ index ].nlentryp;
223 if ( childp -> cyclehead == childp ) {
225 * not yet glommed anywhere, glom it
226 * and fix any children it has glommed
228 tailp -> cnext = childp;
229 childp -> cyclehead = cycleheadp;
231 if ( debug & DFNDEBUG ) {
232 printf( "[dfn_findcycle] glomming " );
235 printname( cycleheadp );
239 for ( tailp = childp ; tailp->cnext ; tailp = tailp->cnext ) {
240 tailp -> cnext -> cyclehead = cycleheadp;
242 if ( debug & DFNDEBUG ) {
243 printf( "[dfn_findcycle] and its tail " );
244 printname( tailp -> cnext );
246 printname( cycleheadp );
251 } else if ( childp -> cyclehead != cycleheadp /* firewall */ ) {
253 "[dfn_busy] glommed, but not to cyclehead\n" );
260 * deal with self-cycles
263 dfn_self_cycle(nltype *parentp)
266 * since we are taking out self-cycles elsewhere
267 * no need for the special case, here.
270 if ( debug & DFNDEBUG ) {
271 printf( "[dfn_self_cycle] " );
272 printname( parentp );
279 * visit a node after all its children
280 * [MISSING: an explanation]
281 * and pop it off the stack
283 dfn_post_visit(nltype *parentp)
288 if ( debug & DFNDEBUG ) {
289 printf( "[dfn_post_visit]\t%d: " , dfn_depth );
290 printname( parentp );
295 * number functions and things in their cycles
296 * unless the function is itself part of a cycle
298 if ( parentp -> cyclehead == parentp ) {
300 for ( memberp = parentp ; memberp ; memberp = memberp -> cnext ) {
301 memberp -> toporder = dfn_counter;
303 if ( debug & DFNDEBUG ) {
304 printf( "[dfn_post_visit]\t\tmember " );
305 printname( memberp );
306 printf( " -> toporder = %d\n" , dfn_counter );
312 if ( debug & DFNDEBUG ) {
313 printf( "[dfn_post_visit]\t\tis part of a cycle\n" );