| 1 | /* |
| 2 | * Copyright (c) 1983, 1993 |
| 3 | * The Regents of the University of California. All rights reserved. |
| 4 | * |
| 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. |
| 16 | * |
| 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. |
| 28 | */ |
| 29 | #include "gprof.h" |
| 30 | #include "libiberty.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" |
| 37 | |
| 38 | #define DFN_INCR_DEPTH (128) |
| 39 | |
| 40 | typedef struct |
| 41 | { |
| 42 | Sym *sym; |
| 43 | int cycle_top; |
| 44 | } |
| 45 | DFN_Stack; |
| 46 | |
| 47 | static bfd_boolean is_numbered (Sym *); |
| 48 | static bfd_boolean is_busy (Sym *); |
| 49 | static void find_cycle (Sym *); |
| 50 | static void pre_visit (Sym *); |
| 51 | static void post_visit (Sym *); |
| 52 | |
| 53 | DFN_Stack *dfn_stack = NULL; |
| 54 | int dfn_maxdepth = 0; |
| 55 | int dfn_depth = 0; |
| 56 | int dfn_counter = DFN_NAN; |
| 57 | |
| 58 | |
| 59 | /* |
| 60 | * Is CHILD already numbered? |
| 61 | */ |
| 62 | static bfd_boolean |
| 63 | is_numbered (Sym *child) |
| 64 | { |
| 65 | return child->cg.top_order != DFN_NAN && child->cg.top_order != DFN_BUSY; |
| 66 | } |
| 67 | |
| 68 | |
| 69 | /* |
| 70 | * Is CHILD already busy? |
| 71 | */ |
| 72 | static bfd_boolean |
| 73 | is_busy (Sym *child) |
| 74 | { |
| 75 | if (child->cg.top_order == DFN_NAN) |
| 76 | { |
| 77 | return FALSE; |
| 78 | } |
| 79 | return TRUE; |
| 80 | } |
| 81 | |
| 82 | |
| 83 | /* |
| 84 | * CHILD is part of a cycle. Find the top caller into this cycle |
| 85 | * that is not part of the cycle and make all functions in cycle |
| 86 | * members of that cycle (top caller == caller with smallest |
| 87 | * depth-first number). |
| 88 | */ |
| 89 | static void |
| 90 | find_cycle (Sym *child) |
| 91 | { |
| 92 | Sym *head = 0; |
| 93 | Sym *tail; |
| 94 | int cycle_top; |
| 95 | int cycle_index; |
| 96 | |
| 97 | for (cycle_top = dfn_depth; cycle_top > 0; --cycle_top) |
| 98 | { |
| 99 | head = dfn_stack[cycle_top].sym; |
| 100 | if (child == head) |
| 101 | { |
| 102 | break; |
| 103 | } |
| 104 | if (child->cg.cyc.head != child && child->cg.cyc.head == head) |
| 105 | { |
| 106 | break; |
| 107 | } |
| 108 | } |
| 109 | if (cycle_top <= 0) |
| 110 | { |
| 111 | fprintf (stderr, "[find_cycle] couldn't find head of cycle\n"); |
| 112 | done (1); |
| 113 | } |
| 114 | #ifdef DEBUG |
| 115 | if (debug_level & DFNDEBUG) |
| 116 | { |
| 117 | printf ("[find_cycle] dfn_depth %d cycle_top %d ", |
| 118 | dfn_depth, cycle_top); |
| 119 | if (head) |
| 120 | { |
| 121 | print_name (head); |
| 122 | } |
| 123 | else |
| 124 | { |
| 125 | printf ("<unknown>"); |
| 126 | } |
| 127 | printf ("\n"); |
| 128 | } |
| 129 | #endif |
| 130 | if (cycle_top == dfn_depth) |
| 131 | { |
| 132 | /* |
| 133 | * This is previous function, e.g. this calls itself. Sort of |
| 134 | * boring. |
| 135 | * |
| 136 | * Since we are taking out self-cycles elsewhere no need for |
| 137 | * the special case, here. |
| 138 | */ |
| 139 | DBG (DFNDEBUG, |
| 140 | printf ("[find_cycle] "); |
| 141 | print_name (child); |
| 142 | printf ("\n")); |
| 143 | } |
| 144 | else |
| 145 | { |
| 146 | /* |
| 147 | * Glom intervening functions that aren't already glommed into |
| 148 | * this cycle. Things have been glommed when their cyclehead |
| 149 | * field points to the head of the cycle they are glommed |
| 150 | * into. |
| 151 | */ |
| 152 | for (tail = head; tail->cg.cyc.next; tail = tail->cg.cyc.next) |
| 153 | { |
| 154 | /* void: chase down to tail of things already glommed */ |
| 155 | DBG (DFNDEBUG, |
| 156 | printf ("[find_cycle] tail "); |
| 157 | print_name (tail); |
| 158 | printf ("\n")); |
| 159 | } |
| 160 | /* |
| 161 | * If what we think is the top of the cycle has a cyclehead |
| 162 | * field, then it's not really the head of the cycle, which is |
| 163 | * really what we want. |
| 164 | */ |
| 165 | if (head->cg.cyc.head != head) |
| 166 | { |
| 167 | head = head->cg.cyc.head; |
| 168 | DBG (DFNDEBUG, printf ("[find_cycle] new cyclehead "); |
| 169 | print_name (head); |
| 170 | printf ("\n")); |
| 171 | } |
| 172 | for (cycle_index = cycle_top + 1; cycle_index <= dfn_depth; ++cycle_index) |
| 173 | { |
| 174 | child = dfn_stack[cycle_index].sym; |
| 175 | if (child->cg.cyc.head == child) |
| 176 | { |
| 177 | /* |
| 178 | * Not yet glommed anywhere, glom it and fix any |
| 179 | * children it has glommed. |
| 180 | */ |
| 181 | tail->cg.cyc.next = child; |
| 182 | child->cg.cyc.head = head; |
| 183 | DBG (DFNDEBUG, printf ("[find_cycle] glomming "); |
| 184 | print_name (child); |
| 185 | printf (" onto "); |
| 186 | print_name (head); |
| 187 | printf ("\n")); |
| 188 | for (tail = child; tail->cg.cyc.next; tail = tail->cg.cyc.next) |
| 189 | { |
| 190 | tail->cg.cyc.next->cg.cyc.head = head; |
| 191 | DBG (DFNDEBUG, printf ("[find_cycle] and its tail "); |
| 192 | print_name (tail->cg.cyc.next); |
| 193 | printf (" onto "); |
| 194 | print_name (head); |
| 195 | printf ("\n")); |
| 196 | } |
| 197 | } |
| 198 | else if (child->cg.cyc.head != head /* firewall */ ) |
| 199 | { |
| 200 | fprintf (stderr, "[find_cycle] glommed, but not to head\n"); |
| 201 | done (1); |
| 202 | } |
| 203 | } |
| 204 | } |
| 205 | } |
| 206 | |
| 207 | |
| 208 | /* |
| 209 | * Prepare for visiting the children of PARENT. Push a parent onto |
| 210 | * the stack and mark it busy. |
| 211 | */ |
| 212 | static void |
| 213 | pre_visit (Sym *parent) |
| 214 | { |
| 215 | ++dfn_depth; |
| 216 | |
| 217 | if (dfn_depth >= dfn_maxdepth) |
| 218 | { |
| 219 | dfn_maxdepth += DFN_INCR_DEPTH; |
| 220 | dfn_stack = (DFN_Stack *) xrealloc (dfn_stack, |
| 221 | dfn_maxdepth * sizeof *dfn_stack); |
| 222 | } |
| 223 | |
| 224 | dfn_stack[dfn_depth].sym = parent; |
| 225 | dfn_stack[dfn_depth].cycle_top = dfn_depth; |
| 226 | parent->cg.top_order = DFN_BUSY; |
| 227 | DBG (DFNDEBUG, printf ("[pre_visit]\t\t%d:", dfn_depth); |
| 228 | print_name (parent); |
| 229 | printf ("\n")); |
| 230 | } |
| 231 | |
| 232 | |
| 233 | /* |
| 234 | * Done with visiting node PARENT. Pop PARENT off dfn_stack |
| 235 | * and number functions if PARENT is head of a cycle. |
| 236 | */ |
| 237 | static void |
| 238 | post_visit (Sym *parent) |
| 239 | { |
| 240 | Sym *member; |
| 241 | |
| 242 | DBG (DFNDEBUG, printf ("[post_visit]\t%d: ", dfn_depth); |
| 243 | print_name (parent); |
| 244 | printf ("\n")); |
| 245 | /* |
| 246 | * Number functions and things in their cycles unless the function |
| 247 | * is itself part of a cycle: |
| 248 | */ |
| 249 | if (parent->cg.cyc.head == parent) |
| 250 | { |
| 251 | ++dfn_counter; |
| 252 | for (member = parent; member; member = member->cg.cyc.next) |
| 253 | { |
| 254 | member->cg.top_order = dfn_counter; |
| 255 | DBG (DFNDEBUG, printf ("[post_visit]\t\tmember "); |
| 256 | print_name (member); |
| 257 | printf ("-> cg.top_order = %d\n", dfn_counter)); |
| 258 | } |
| 259 | } |
| 260 | else |
| 261 | { |
| 262 | DBG (DFNDEBUG, printf ("[post_visit]\t\tis part of a cycle\n")); |
| 263 | } |
| 264 | --dfn_depth; |
| 265 | } |
| 266 | |
| 267 | |
| 268 | /* |
| 269 | * Given this PARENT, depth first number its children. |
| 270 | */ |
| 271 | void |
| 272 | cg_dfn (Sym *parent) |
| 273 | { |
| 274 | Arc *arc; |
| 275 | |
| 276 | DBG (DFNDEBUG, printf ("[dfn] dfn( "); |
| 277 | print_name (parent); |
| 278 | printf (")\n")); |
| 279 | /* |
| 280 | * If we're already numbered, no need to look any further: |
| 281 | */ |
| 282 | if (is_numbered (parent)) |
| 283 | { |
| 284 | return; |
| 285 | } |
| 286 | /* |
| 287 | * If we're already busy, must be a cycle: |
| 288 | */ |
| 289 | if (is_busy (parent)) |
| 290 | { |
| 291 | find_cycle (parent); |
| 292 | return; |
| 293 | } |
| 294 | pre_visit (parent); |
| 295 | /* |
| 296 | * Recursively visit children: |
| 297 | */ |
| 298 | for (arc = parent->cg.children; arc; arc = arc->next_child) |
| 299 | { |
| 300 | cg_dfn (arc->child); |
| 301 | } |
| 302 | post_visit (parent); |
| 303 | } |