ace8328d1411f0616df11dfdef3ed149574addd6
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.
19 #include "libiberty.h"
21 #include "search_list.h"
28 #define DFN_INCR_DEPTH (128)
37 DFN_Stack
*dfn_stack
= NULL
;
40 int dfn_counter
= DFN_NAN
;
44 * Is CHILD already numbered?
47 DEFUN (is_numbered
, (child
), Sym
* child
)
49 return child
->cg
.top_order
!= DFN_NAN
&& child
->cg
.top_order
!= DFN_BUSY
;
54 * Is CHILD already busy?
57 DEFUN (is_busy
, (child
), Sym
* child
)
59 if (child
->cg
.top_order
== DFN_NAN
)
68 * CHILD is part of a cycle. Find the top caller into this cycle
69 * that is not part of the cycle and make all functions in cycle
70 * members of that cycle (top caller == caller with smallest
71 * depth-first number).
74 DEFUN (find_cycle
, (child
), Sym
* child
)
81 for (cycle_top
= dfn_depth
; cycle_top
> 0; --cycle_top
)
83 head
= dfn_stack
[cycle_top
].sym
;
88 if (child
->cg
.cyc
.head
!= child
&& child
->cg
.cyc
.head
== head
)
95 fprintf (stderr
, "[find_cycle] couldn't find head of cycle\n");
99 if (debug_level
& DFNDEBUG
)
101 printf ("[find_cycle] dfn_depth %d cycle_top %d ",
102 dfn_depth
, cycle_top
);
109 printf ("<unknown>");
114 if (cycle_top
== dfn_depth
)
117 * This is previous function, e.g. this calls itself. Sort of
120 * Since we are taking out self-cycles elsewhere no need for
121 * the special case, here.
124 printf ("[find_cycle] ");
131 * Glom intervening functions that aren't already glommed into
132 * this cycle. Things have been glommed when their cyclehead
133 * field points to the head of the cycle they are glommed
136 for (tail
= head
; tail
->cg
.cyc
.next
; tail
= tail
->cg
.cyc
.next
)
138 /* void: chase down to tail of things already glommed */
140 printf ("[find_cycle] tail ");
145 * If what we think is the top of the cycle has a cyclehead
146 * field, then it's not really the head of the cycle, which is
147 * really what we want.
149 if (head
->cg
.cyc
.head
!= head
)
151 head
= head
->cg
.cyc
.head
;
152 DBG (DFNDEBUG
, printf ("[find_cycle] new cyclehead ");
156 for (index
= cycle_top
+ 1; index
<= dfn_depth
; ++index
)
158 child
= dfn_stack
[index
].sym
;
159 if (child
->cg
.cyc
.head
== child
)
162 * Not yet glommed anywhere, glom it and fix any
163 * children it has glommed.
165 tail
->cg
.cyc
.next
= child
;
166 child
->cg
.cyc
.head
= head
;
167 DBG (DFNDEBUG
, printf ("[find_cycle] glomming ");
172 for (tail
= child
; tail
->cg
.cyc
.next
; tail
= tail
->cg
.cyc
.next
)
174 tail
->cg
.cyc
.next
->cg
.cyc
.head
= head
;
175 DBG (DFNDEBUG
, printf ("[find_cycle] and its tail ");
176 print_name (tail
->cg
.cyc
.next
);
182 else if (child
->cg
.cyc
.head
!= head
/* firewall */ )
184 fprintf (stderr
, "[find_cycle] glommed, but not to head\n");
193 * Prepare for visiting the children of PARENT. Push a parent onto
194 * the stack and mark it busy.
197 DEFUN (pre_visit
, (parent
), Sym
* parent
)
201 if (dfn_depth
>= dfn_maxdepth
)
203 dfn_maxdepth
+= DFN_INCR_DEPTH
;
204 dfn_stack
= xrealloc (dfn_stack
, dfn_maxdepth
* sizeof *dfn_stack
);
207 dfn_stack
[dfn_depth
].sym
= parent
;
208 dfn_stack
[dfn_depth
].cycle_top
= dfn_depth
;
209 parent
->cg
.top_order
= DFN_BUSY
;
210 DBG (DFNDEBUG
, printf ("[pre_visit]\t\t%d:", dfn_depth
);
217 * Done with visiting node PARENT. Pop PARENT off dfn_stack
218 * and number functions if PARENT is head of a cycle.
221 DEFUN (post_visit
, (parent
), Sym
* parent
)
225 DBG (DFNDEBUG
, printf ("[post_visit]\t%d: ", dfn_depth
);
229 * Number functions and things in their cycles unless the function
230 * is itself part of a cycle:
232 if (parent
->cg
.cyc
.head
== parent
)
235 for (member
= parent
; member
; member
= member
->cg
.cyc
.next
)
237 member
->cg
.top_order
= dfn_counter
;
238 DBG (DFNDEBUG
, printf ("[post_visit]\t\tmember ");
240 printf ("-> cg.top_order = %d\n", dfn_counter
));
245 DBG (DFNDEBUG
, printf ("[post_visit]\t\tis part of a cycle\n"));
252 * Given this PARENT, depth first number its children.
255 DEFUN (cg_dfn
, (parent
), Sym
* parent
)
259 DBG (DFNDEBUG
, printf ("[dfn] dfn( ");
263 * If we're already numbered, no need to look any further:
265 if (is_numbered (parent
))
270 * If we're already busy, must be a cycle:
272 if (is_busy (parent
))
279 * Recursively visit children:
281 for (arc
= parent
->cg
.children
; arc
; arc
= arc
->next_child
)
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