| /* |
| * Copyright (c) 1983 Regents of the University of California. |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms are permitted |
| * provided that: (1) source distributions retain this entire copyright |
| * notice and comment, and (2) distributions including binaries display |
| * the following acknowledgement: ``This product includes software |
| * developed by the University of California, Berkeley and its contributors'' |
| * in the documentation or other materials provided with the distribution |
| * and in all advertising materials mentioning features or use of this |
| * software. Neither the name of the University nor the names of its |
| * contributors may be used to endorse or promote products derived |
| * from this software without specific prior written permission. |
| * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR |
| * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED |
| * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. |
| */ |
| #include <stdio.h> |
| #include "libiberty.h" |
| #include "gprof.h" |
| #include "cg_arcs.h" |
| #include "cg_dfn.h" |
| #include "symtab.h" |
| #include "utils.h" |
| |
| #define DFN_INCR_DEPTH (128) |
| |
| typedef struct |
| { |
| Sym *sym; |
| int cycle_top; |
| } |
| DFN_Stack; |
| |
| DFN_Stack *dfn_stack = NULL; |
| int dfn_maxdepth = 0; |
| int dfn_depth = 0; |
| int dfn_counter = DFN_NAN; |
| |
| |
| /* |
| * Is CHILD already numbered? |
| */ |
| static bool |
| DEFUN (is_numbered, (child), Sym * child) |
| { |
| return child->cg.top_order != DFN_NAN && child->cg.top_order != DFN_BUSY; |
| } |
| |
| |
| /* |
| * Is CHILD already busy? |
| */ |
| static bool |
| DEFUN (is_busy, (child), Sym * child) |
| { |
| if (child->cg.top_order == DFN_NAN) |
| { |
| return FALSE; |
| } |
| return TRUE; |
| } |
| |
| |
| /* |
| * CHILD is part of a cycle. Find the top caller into this cycle |
| * that is not part of the cycle and make all functions in cycle |
| * members of that cycle (top caller == caller with smallest |
| * depth-first number). |
| */ |
| static void |
| DEFUN (find_cycle, (child), Sym * child) |
| { |
| Sym *head = 0; |
| Sym *tail; |
| int cycle_top; |
| int index; |
| |
| for (cycle_top = dfn_depth; cycle_top > 0; --cycle_top) |
| { |
| head = dfn_stack[cycle_top].sym; |
| if (child == head) |
| { |
| break; |
| } |
| if (child->cg.cyc.head != child && child->cg.cyc.head == head) |
| { |
| break; |
| } |
| } |
| if (cycle_top <= 0) |
| { |
| fprintf (stderr, "[find_cycle] couldn't find head of cycle\n"); |
| done (1); |
| } |
| #ifdef DEBUG |
| if (debug_level & DFNDEBUG) |
| { |
| printf ("[find_cycle] dfn_depth %d cycle_top %d ", |
| dfn_depth, cycle_top); |
| if (head) |
| { |
| print_name (head); |
| } |
| else |
| { |
| printf ("<unknown>"); |
| } |
| printf ("\n"); |
| } |
| #endif |
| if (cycle_top == dfn_depth) |
| { |
| /* |
| * This is previous function, e.g. this calls itself. Sort of |
| * boring. |
| * |
| * Since we are taking out self-cycles elsewhere no need for |
| * the special case, here. |
| */ |
| DBG (DFNDEBUG, |
| printf ("[find_cycle] "); |
| print_name (child); |
| printf ("\n")); |
| } |
| else |
| { |
| /* |
| * Glom intervening functions that aren't already glommed into |
| * this cycle. Things have been glommed when their cyclehead |
| * field points to the head of the cycle they are glommed |
| * into. |
| */ |
| for (tail = head; tail->cg.cyc.next; tail = tail->cg.cyc.next) |
| { |
| /* void: chase down to tail of things already glommed */ |
| DBG (DFNDEBUG, |
| printf ("[find_cycle] tail "); |
| print_name (tail); |
| printf ("\n")); |
| } |
| /* |
| * If what we think is the top of the cycle has a cyclehead |
| * field, then it's not really the head of the cycle, which is |
| * really what we want. |
| */ |
| if (head->cg.cyc.head != head) |
| { |
| head = head->cg.cyc.head; |
| DBG (DFNDEBUG, printf ("[find_cycle] new cyclehead "); |
| print_name (head); |
| printf ("\n")); |
| } |
| for (index = cycle_top + 1; index <= dfn_depth; ++index) |
| { |
| child = dfn_stack[index].sym; |
| if (child->cg.cyc.head == child) |
| { |
| /* |
| * Not yet glommed anywhere, glom it and fix any |
| * children it has glommed. |
| */ |
| tail->cg.cyc.next = child; |
| child->cg.cyc.head = head; |
| DBG (DFNDEBUG, printf ("[find_cycle] glomming "); |
| print_name (child); |
| printf (" onto "); |
| print_name (head); |
| printf ("\n")); |
| for (tail = child; tail->cg.cyc.next; tail = tail->cg.cyc.next) |
| { |
| tail->cg.cyc.next->cg.cyc.head = head; |
| DBG (DFNDEBUG, printf ("[find_cycle] and its tail "); |
| print_name (tail->cg.cyc.next); |
| printf (" onto "); |
| print_name (head); |
| printf ("\n")); |
| } |
| } |
| else if (child->cg.cyc.head != head /* firewall */ ) |
| { |
| fprintf (stderr, "[find_cycle] glommed, but not to head\n"); |
| done (1); |
| } |
| } |
| } |
| } |
| |
| |
| /* |
| * Prepare for visiting the children of PARENT. Push a parent onto |
| * the stack and mark it busy. |
| */ |
| static void |
| DEFUN (pre_visit, (parent), Sym * parent) |
| { |
| ++dfn_depth; |
| |
| if (dfn_depth >= dfn_maxdepth) |
| { |
| dfn_maxdepth += DFN_INCR_DEPTH; |
| dfn_stack = xrealloc (dfn_stack, dfn_maxdepth * sizeof *dfn_stack); |
| } |
| |
| dfn_stack[dfn_depth].sym = parent; |
| dfn_stack[dfn_depth].cycle_top = dfn_depth; |
| parent->cg.top_order = DFN_BUSY; |
| DBG (DFNDEBUG, printf ("[pre_visit]\t\t%d:", dfn_depth); |
| print_name (parent); |
| printf ("\n")); |
| } |
| |
| |
| /* |
| * Done with visiting node PARENT. Pop PARENT off dfn_stack |
| * and number functions if PARENT is head of a cycle. |
| */ |
| static void |
| DEFUN (post_visit, (parent), Sym * parent) |
| { |
| Sym *member; |
| |
| DBG (DFNDEBUG, printf ("[post_visit]\t%d: ", dfn_depth); |
| print_name (parent); |
| printf ("\n")); |
| /* |
| * Number functions and things in their cycles unless the function |
| * is itself part of a cycle: |
| */ |
| if (parent->cg.cyc.head == parent) |
| { |
| ++dfn_counter; |
| for (member = parent; member; member = member->cg.cyc.next) |
| { |
| member->cg.top_order = dfn_counter; |
| DBG (DFNDEBUG, printf ("[post_visit]\t\tmember "); |
| print_name (member); |
| printf ("-> cg.top_order = %d\n", dfn_counter)); |
| } |
| } |
| else |
| { |
| DBG (DFNDEBUG, printf ("[post_visit]\t\tis part of a cycle\n")); |
| } |
| --dfn_depth; |
| } |
| |
| |
| /* |
| * Given this PARENT, depth first number its children. |
| */ |
| void |
| DEFUN (cg_dfn, (parent), Sym * parent) |
| { |
| Arc *arc; |
| |
| DBG (DFNDEBUG, printf ("[dfn] dfn( "); |
| print_name (parent); |
| printf (")\n")); |
| /* |
| * If we're already numbered, no need to look any further: |
| */ |
| if (is_numbered (parent)) |
| { |
| return; |
| } |
| /* |
| * If we're already busy, must be a cycle: |
| */ |
| if (is_busy (parent)) |
| { |
| find_cycle (parent); |
| return; |
| } |
| pre_visit (parent); |
| /* |
| * Recursively visit children: |
| */ |
| for (arc = parent->cg.children; arc; arc = arc->next_child) |
| { |
| cg_dfn (arc->child); |
| } |
| post_visit (parent); |
| } |