2 * Copyright (c) 1983 Regents of the University of California.
5 * Redistribution and use in source and binary forms are permitted
6 * provided that: (1) source distributions retain this entire copyright
7 * notice and comment, and (2) distributions including binaries display
8 * the following acknowledgement: ``This product includes software
9 * developed by the University of California, Berkeley and its contributors''
10 * in the documentation or other materials provided with the distribution
11 * and in all advertising materials mentioning features or use of this
12 * software. Neither the name of the University nor the names of its
13 * contributors may be used to endorse or promote products derived
14 * from this software without specific prior written permission.
15 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
17 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
20 #include "libiberty.h"
27 #define DFN_INCR_DEPTH (128)
36 DFN_Stack *dfn_stack = NULL;
39 int dfn_counter = DFN_NAN;
43 * Is CHILD already numbered?
46 DEFUN (is_numbered, (child), Sym * child)
48 return child->cg.top_order != DFN_NAN && child->cg.top_order != DFN_BUSY;
53 * Is CHILD already busy?
56 DEFUN (is_busy, (child), Sym * child)
58 if (child->cg.top_order == DFN_NAN)
67 * CHILD is part of a cycle. Find the top caller into this cycle
68 * that is not part of the cycle and make all functions in cycle
69 * members of that cycle (top caller == caller with smallest
70 * depth-first number).
73 DEFUN (find_cycle, (child), Sym * child)
80 for (cycle_top = dfn_depth; cycle_top > 0; --cycle_top)
82 head = dfn_stack[cycle_top].sym;
87 if (child->cg.cyc.head != child && child->cg.cyc.head == head)
94 fprintf (stderr, "[find_cycle] couldn't find head of cycle\n");
98 if (debug_level & DFNDEBUG)
100 printf ("[find_cycle] dfn_depth %d cycle_top %d ",
101 dfn_depth, cycle_top);
108 printf ("<unknown>");
113 if (cycle_top == dfn_depth)
116 * This is previous function, e.g. this calls itself. Sort of
119 * Since we are taking out self-cycles elsewhere no need for
120 * the special case, here.
123 printf ("[find_cycle] ");
130 * Glom intervening functions that aren't already glommed into
131 * this cycle. Things have been glommed when their cyclehead
132 * field points to the head of the cycle they are glommed
135 for (tail = head; tail->cg.cyc.next; tail = tail->cg.cyc.next)
137 /* void: chase down to tail of things already glommed */
139 printf ("[find_cycle] tail ");
144 * If what we think is the top of the cycle has a cyclehead
145 * field, then it's not really the head of the cycle, which is
146 * really what we want.
148 if (head->cg.cyc.head != head)
150 head = head->cg.cyc.head;
151 DBG (DFNDEBUG, printf ("[find_cycle] new cyclehead ");
155 for (index = cycle_top + 1; index <= dfn_depth; ++index)
157 child = dfn_stack[index].sym;
158 if (child->cg.cyc.head == child)
161 * Not yet glommed anywhere, glom it and fix any
162 * children it has glommed.
164 tail->cg.cyc.next = child;
165 child->cg.cyc.head = head;
166 DBG (DFNDEBUG, printf ("[find_cycle] glomming ");
171 for (tail = child; tail->cg.cyc.next; tail = tail->cg.cyc.next)
173 tail->cg.cyc.next->cg.cyc.head = head;
174 DBG (DFNDEBUG, printf ("[find_cycle] and its tail ");
175 print_name (tail->cg.cyc.next);
181 else if (child->cg.cyc.head != head /* firewall */ )
183 fprintf (stderr, "[find_cycle] glommed, but not to head\n");
192 * Prepare for visiting the children of PARENT. Push a parent onto
193 * the stack and mark it busy.
196 DEFUN (pre_visit, (parent), Sym * parent)
200 if (dfn_depth >= dfn_maxdepth)
202 dfn_maxdepth += DFN_INCR_DEPTH;
203 dfn_stack = xrealloc (dfn_stack, dfn_maxdepth * sizeof *dfn_stack);
206 dfn_stack[dfn_depth].sym = parent;
207 dfn_stack[dfn_depth].cycle_top = dfn_depth;
208 parent->cg.top_order = DFN_BUSY;
209 DBG (DFNDEBUG, printf ("[pre_visit]\t\t%d:", dfn_depth);
216 * Done with visiting node PARENT. Pop PARENT off dfn_stack
217 * and number functions if PARENT is head of a cycle.
220 DEFUN (post_visit, (parent), Sym * parent)
224 DBG (DFNDEBUG, printf ("[post_visit]\t%d: ", dfn_depth);
228 * Number functions and things in their cycles unless the function
229 * is itself part of a cycle:
231 if (parent->cg.cyc.head == parent)
234 for (member = parent; member; member = member->cg.cyc.next)
236 member->cg.top_order = dfn_counter;
237 DBG (DFNDEBUG, printf ("[post_visit]\t\tmember ");
239 printf ("-> cg.top_order = %d\n", dfn_counter));
244 DBG (DFNDEBUG, printf ("[post_visit]\t\tis part of a cycle\n"));
251 * Given this PARENT, depth first number its children.
254 DEFUN (cg_dfn, (parent), Sym * parent)
258 DBG (DFNDEBUG, printf ("[dfn] dfn( ");
262 * If we're already numbered, no need to look any further:
264 if (is_numbered (parent))
269 * If we're already busy, must be a cycle:
271 if (is_busy (parent))
278 * Recursively visit children:
280 for (arc = parent->cg.children; arc; arc = arc->next_child)