19990502 sourceware importbinu_ss_19990502

1 files changed, 281 insertions, 0 deletions

diff --git a/gprof/cg_dfn.c b/gprof/cg_dfn.c
new file mode 100644
index 0000000..c9e37ab
--- /dev/null
+++ b/gprof/cg_dfn.c
@@ -0,0 +1,281 @@
+/*
+ * 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 "gprof.h"
+#include "cg_arcs.h"
+#include "cg_dfn.h"
+#include "symtab.h"
+#include "utils.h"
+
+#define	DFN_DEPTH	100
+
+typedef struct
+  {
+    Sym *sym;
+    int cycle_top;
+  }
+DFN_Stack;
+
+DFN_Stack dfn_stack[DFN_DEPTH];
+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_DEPTH)
+    {
+      fprintf (stderr, "[pre_visit] dfn_stack overflow\n");
+      done (1);
+    }
+  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);
+}