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[binutils.git] / gprof / cg_dfn.c
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1 /*
2 * Copyright (c) 1983, 1993
3 * The Regents of the University of California. All rights reserved.
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. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
29 #include "libiberty.h"
30 #include "gprof.h"
31 #include "search_list.h"
32 #include "source.h"
33 #include "symtab.h"
34 #include "cg_arcs.h"
35 #include "cg_dfn.h"
36 #include "utils.h"
38 #define DFN_INCR_DEPTH (128)
40 typedef struct
42 Sym *sym;
43 int cycle_top;
45 DFN_Stack;
47 static bfd_boolean is_numbered PARAMS ((Sym *));
48 static bfd_boolean is_busy PARAMS ((Sym *));
49 static void find_cycle PARAMS ((Sym *));
50 static void pre_visit PARAMS ((Sym *));
51 static void post_visit PARAMS ((Sym *));
53 DFN_Stack *dfn_stack = NULL;
54 int dfn_maxdepth = 0;
55 int dfn_depth = 0;
56 int dfn_counter = DFN_NAN;
60 * Is CHILD already numbered?
62 static bfd_boolean
63 is_numbered (child)
64 Sym *child;
66 return child->cg.top_order != DFN_NAN && child->cg.top_order != DFN_BUSY;
71 * Is CHILD already busy?
73 static bfd_boolean
74 is_busy (child)
75 Sym *child;
77 if (child->cg.top_order == DFN_NAN)
79 return FALSE;
81 return TRUE;
86 * CHILD is part of a cycle. Find the top caller into this cycle
87 * that is not part of the cycle and make all functions in cycle
88 * members of that cycle (top caller == caller with smallest
89 * depth-first number).
91 static void
92 find_cycle (child)
93 Sym *child;
95 Sym *head = 0;
96 Sym *tail;
97 int cycle_top;
98 int index;
100 for (cycle_top = dfn_depth; cycle_top > 0; --cycle_top)
102 head = dfn_stack[cycle_top].sym;
103 if (child == head)
105 break;
107 if (child->cg.cyc.head != child && child->cg.cyc.head == head)
109 break;
112 if (cycle_top <= 0)
114 fprintf (stderr, "[find_cycle] couldn't find head of cycle\n");
115 done (1);
117 #ifdef DEBUG
118 if (debug_level & DFNDEBUG)
120 printf ("[find_cycle] dfn_depth %d cycle_top %d ",
121 dfn_depth, cycle_top);
122 if (head)
124 print_name (head);
126 else
128 printf ("<unknown>");
130 printf ("\n");
132 #endif
133 if (cycle_top == dfn_depth)
136 * This is previous function, e.g. this calls itself. Sort of
137 * boring.
139 * Since we are taking out self-cycles elsewhere no need for
140 * the special case, here.
142 DBG (DFNDEBUG,
143 printf ("[find_cycle] ");
144 print_name (child);
145 printf ("\n"));
147 else
150 * Glom intervening functions that aren't already glommed into
151 * this cycle. Things have been glommed when their cyclehead
152 * field points to the head of the cycle they are glommed
153 * into.
155 for (tail = head; tail->cg.cyc.next; tail = tail->cg.cyc.next)
157 /* void: chase down to tail of things already glommed */
158 DBG (DFNDEBUG,
159 printf ("[find_cycle] tail ");
160 print_name (tail);
161 printf ("\n"));
164 * If what we think is the top of the cycle has a cyclehead
165 * field, then it's not really the head of the cycle, which is
166 * really what we want.
168 if (head->cg.cyc.head != head)
170 head = head->cg.cyc.head;
171 DBG (DFNDEBUG, printf ("[find_cycle] new cyclehead ");
172 print_name (head);
173 printf ("\n"));
175 for (index = cycle_top + 1; index <= dfn_depth; ++index)
177 child = dfn_stack[index].sym;
178 if (child->cg.cyc.head == child)
181 * Not yet glommed anywhere, glom it and fix any
182 * children it has glommed.
184 tail->cg.cyc.next = child;
185 child->cg.cyc.head = head;
186 DBG (DFNDEBUG, printf ("[find_cycle] glomming ");
187 print_name (child);
188 printf (" onto ");
189 print_name (head);
190 printf ("\n"));
191 for (tail = child; tail->cg.cyc.next; tail = tail->cg.cyc.next)
193 tail->cg.cyc.next->cg.cyc.head = head;
194 DBG (DFNDEBUG, printf ("[find_cycle] and its tail ");
195 print_name (tail->cg.cyc.next);
196 printf (" onto ");
197 print_name (head);
198 printf ("\n"));
201 else if (child->cg.cyc.head != head /* firewall */ )
203 fprintf (stderr, "[find_cycle] glommed, but not to head\n");
204 done (1);
212 * Prepare for visiting the children of PARENT. Push a parent onto
213 * the stack and mark it busy.
215 static void
216 pre_visit (parent)
217 Sym *parent;
219 ++dfn_depth;
221 if (dfn_depth >= dfn_maxdepth)
223 dfn_maxdepth += DFN_INCR_DEPTH;
224 dfn_stack = xrealloc (dfn_stack, dfn_maxdepth * sizeof *dfn_stack);
227 dfn_stack[dfn_depth].sym = parent;
228 dfn_stack[dfn_depth].cycle_top = dfn_depth;
229 parent->cg.top_order = DFN_BUSY;
230 DBG (DFNDEBUG, printf ("[pre_visit]\t\t%d:", dfn_depth);
231 print_name (parent);
232 printf ("\n"));
237 * Done with visiting node PARENT. Pop PARENT off dfn_stack
238 * and number functions if PARENT is head of a cycle.
240 static void
241 post_visit (parent)
242 Sym *parent;
244 Sym *member;
246 DBG (DFNDEBUG, printf ("[post_visit]\t%d: ", dfn_depth);
247 print_name (parent);
248 printf ("\n"));
250 * Number functions and things in their cycles unless the function
251 * is itself part of a cycle:
253 if (parent->cg.cyc.head == parent)
255 ++dfn_counter;
256 for (member = parent; member; member = member->cg.cyc.next)
258 member->cg.top_order = dfn_counter;
259 DBG (DFNDEBUG, printf ("[post_visit]\t\tmember ");
260 print_name (member);
261 printf ("-> cg.top_order = %d\n", dfn_counter));
264 else
266 DBG (DFNDEBUG, printf ("[post_visit]\t\tis part of a cycle\n"));
268 --dfn_depth;
273 * Given this PARENT, depth first number its children.
275 void
276 cg_dfn (parent)
277 Sym *parent;
279 Arc *arc;
281 DBG (DFNDEBUG, printf ("[dfn] dfn( ");
282 print_name (parent);
283 printf (")\n"));
285 * If we're already numbered, no need to look any further:
287 if (is_numbered (parent))
289 return;
292 * If we're already busy, must be a cycle:
294 if (is_busy (parent))
296 find_cycle (parent);
297 return;
299 pre_visit (parent);
301 * Recursively visit children:
303 for (arc = parent->cg.children; arc; arc = arc->next_child)
305 cg_dfn (arc->child);
307 post_visit (parent);