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git.ipfire.org Git - thirdparty/binutils-gdb.git/blob - gprof/cg_dfn.c
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.
33 DFN_Stack dfn_stack
[DFN_DEPTH
];
35 int dfn_counter
= DFN_NAN
;
39 * Is CHILD already numbered?
42 DEFUN(is_numbered
, (child
), Sym
*child
)
44 return child
->cg
.top_order
!= DFN_NAN
&& child
->cg
.top_order
!= DFN_BUSY
;
49 * Is CHILD already busy?
52 DEFUN(is_busy
, (child
), Sym
*child
)
54 if (child
->cg
.top_order
== DFN_NAN
) {
62 * CHILD is part of a cycle. Find the top caller into this cycle
63 * that is not part of the cycle and make all functions in cycle
64 * members of that cycle (top caller == caller with smallest
65 * depth-first number).
68 DEFUN(find_cycle
, (child
), Sym
*child
)
75 for (cycle_top
= dfn_depth
; cycle_top
> 0; --cycle_top
) {
76 head
= dfn_stack
[cycle_top
].sym
;
80 if (child
->cg
.cyc
.head
!= child
&& child
->cg
.cyc
.head
== head
) {
85 fprintf(stderr
, "[find_cycle] couldn't find head of cycle\n");
88 DBG(DFNDEBUG
, printf("[find_cycle] dfn_depth %d cycle_top %d ",
89 dfn_depth
, cycle_top
);
96 if (cycle_top
== dfn_depth
) {
98 * This is previous function, e.g. this calls itself. Sort of
101 * Since we are taking out self-cycles elsewhere no need for
102 * the special case, here.
105 printf("[find_cycle] "); print_name(child
); printf("\n"));
108 * Glom intervening functions that aren't already glommed into
109 * this cycle. Things have been glommed when their cyclehead
110 * field points to the head of the cycle they are glommed
113 for (tail
= head
; tail
->cg
.cyc
.next
; tail
= tail
->cg
.cyc
.next
) {
114 /* void: chase down to tail of things already glommed */
116 printf("[find_cycle] tail "); print_name(tail
); printf("\n"));
119 * If what we think is the top of the cycle has a cyclehead
120 * field, then it's not really the head of the cycle, which is
121 * really what we want.
123 if (head
->cg
.cyc
.head
!= head
) {
124 head
= head
->cg
.cyc
.head
;
125 DBG(DFNDEBUG
, printf("[find_cycle] new cyclehead ");
126 print_name(head
); printf("\n"));
128 for (index
= cycle_top
+ 1; index
<= dfn_depth
; ++index
) {
129 child
= dfn_stack
[index
].sym
;
130 if (child
->cg
.cyc
.head
== child
) {
132 * Not yet glommed anywhere, glom it and fix any
133 * children it has glommed.
135 tail
->cg
.cyc
.next
= child
;
136 child
->cg
.cyc
.head
= head
;
137 DBG(DFNDEBUG
, printf("[find_cycle] glomming ");
138 print_name(child
); printf(" onto "); print_name(head
);
140 for (tail
= child
; tail
->cg
.cyc
.next
; tail
= tail
->cg
.cyc
.next
)
142 tail
->cg
.cyc
.next
->cg
.cyc
.head
= head
;
143 DBG(DFNDEBUG
, printf("[find_cycle] and its tail ");
144 print_name(tail
->cg
.cyc
.next
); printf(" onto ");
145 print_name(head
); printf("\n"));
147 } else if (child
->cg
.cyc
.head
!= head
/* firewall */) {
148 fprintf(stderr
, "[find_cycle] glommed, but not to head\n");
157 * Prepare for visiting the children of PARENT. Push a parent onto
158 * the stack and mark it busy.
161 DEFUN(pre_visit
, (parent
), Sym
*parent
)
164 if (dfn_depth
>= DFN_DEPTH
) {
165 fprintf(stderr
, "[pre_visit] dfn_stack overflow\n");
168 dfn_stack
[dfn_depth
].sym
= parent
;
169 dfn_stack
[dfn_depth
].cycle_top
= dfn_depth
;
170 parent
->cg
.top_order
= DFN_BUSY
;
171 DBG(DFNDEBUG
, printf("[pre_visit]\t\t%d:", dfn_depth
); print_name(parent
);
177 * Done with visiting node PARENT. Pop PARENT off dfn_stack
178 * and number functions if PARENT is head of a cycle.
181 DEFUN(post_visit
, (parent
), Sym
*parent
)
185 DBG(DFNDEBUG
, printf("[post_visit]\t%d: ", dfn_depth
);
186 print_name(parent
); printf("\n"));
188 * Number functions and things in their cycles unless the function
189 * is itself part of a cycle:
191 if (parent
->cg
.cyc
.head
== parent
) {
193 for (member
= parent
; member
; member
= member
->cg
.cyc
.next
) {
194 member
->cg
.top_order
= dfn_counter
;
195 DBG(DFNDEBUG
, printf("[post_visit]\t\tmember ");
197 printf("-> cg.top_order = %d\n", dfn_counter
));
200 DBG(DFNDEBUG
, printf("[post_visit]\t\tis part of a cycle\n"));
207 * Given this PARENT, depth first number its children.
210 DEFUN(cg_dfn
, (parent
), Sym
*parent
)
214 DBG(DFNDEBUG
, printf("[dfn] dfn( "); print_name(parent
); printf(")\n"));
216 * If we're already numbered, no need to look any further:
218 if (is_numbered(parent
)) {
222 * If we're already busy, must be a cycle:
224 if (is_busy(parent
)) {
230 * Recursively visit children:
232 for (arc
= parent
->cg
.children
; arc
; arc
= arc
->next_child
) {
238 /*** end of cg_dfn.c ***/