Initial revision

1 files changed, 302 insertions, 0 deletions

diff --git a/gprof/dfn.c b/gprof/dfn.c
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--- /dev/null
+++ b/gprof/dfn.c
@@ -0,0 +1,302 @@
+/*
+ * 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.
+ */
+
+#ifndef lint
+static char sccsid[] = "@(#)dfn.c	5.4 (Berkeley) 6/1/90";
+#endif /* not lint */
+
+#include <stdio.h>
+#include "gprof.h"
+
+#define	DFN_DEPTH	100
+struct dfnstruct {
+    nltype	*nlentryp;
+    int		cycletop;
+};
+typedef struct dfnstruct	dfntype;
+
+dfntype	dfn_stack[ DFN_DEPTH ];
+int	dfn_depth = 0;
+
+int	dfn_counter = DFN_NAN;
+
+    /*
+     *	given this parent, depth first number its children.
+     */
+dfn( parentp )
+    nltype	*parentp;
+{
+    arctype	*arcp;
+
+#   ifdef DEBUG
+	if ( debug & DFNDEBUG ) {
+	    printf( "[dfn] dfn(" );
+	    printname( parentp );
+	    printf( ")\n" );
+	}
+#   endif DEBUG
+	/*
+	 *	if we're already numbered, no need to look any furthur.
+	 */
+    if ( dfn_numbered( parentp ) ) {
+	return;
+    }
+	/*
+	 *	if we're already busy, must be a cycle
+	 */
+    if ( dfn_busy( parentp ) ) {
+	dfn_findcycle( parentp );
+	return;
+    }
+	/*
+	 *	visit yourself before your children
+	 */
+    dfn_pre_visit( parentp );
+	/*
+	 *	visit children
+	 */
+    for ( arcp = parentp -> children ; arcp ; arcp = arcp -> arc_childlist ) {
+	    dfn( arcp -> arc_childp );
+    }
+	/*
+	 *	visit yourself after your children
+	 */
+    dfn_post_visit( parentp );
+}
+
+    /*
+     *	push a parent onto the stack and mark it busy
+     */
+dfn_pre_visit( parentp )
+    nltype	*parentp;
+{
+
+    dfn_depth += 1;
+    if ( dfn_depth >= DFN_DEPTH ) {
+	fprintf( stderr , "[dfn] out of my depth (dfn_stack overflow)\n" );
+	exit( 1 );
+    }
+    dfn_stack[ dfn_depth ].nlentryp = parentp;
+    dfn_stack[ dfn_depth ].cycletop = dfn_depth;
+    parentp -> toporder = DFN_BUSY;
+#   ifdef DEBUG
+	if ( debug & DFNDEBUG ) {
+	    printf( "[dfn_pre_visit]\t\t%d:" , dfn_depth );
+	    printname( parentp );
+	    printf( "\n" );
+	}
+#   endif DEBUG
+}
+
+    /*
+     *	are we already numbered?
+     */
+bool
+dfn_numbered( childp )
+    nltype	*childp;
+{
+    
+    return ( childp -> toporder != DFN_NAN && childp -> toporder != DFN_BUSY );
+}
+
+    /*
+     *	are we already busy?
+     */
+bool
+dfn_busy( childp )
+    nltype	*childp;
+{
+
+    if ( childp -> toporder == DFN_NAN ) {
+	return FALSE;
+    }
+    return TRUE;
+}
+
+    /*
+     *	MISSING: an explanation
+     */
+dfn_findcycle( childp )
+    nltype	*childp;
+{
+    int		cycletop;
+    nltype	*cycleheadp;
+    nltype	*tailp;
+    int		index;
+
+    for ( cycletop = dfn_depth ; cycletop > 0 ; cycletop -= 1 ) {
+	cycleheadp = dfn_stack[ cycletop ].nlentryp;
+	if ( childp == cycleheadp ) {
+	    break;
+	}
+	if ( childp -> cyclehead != childp &&
+	    childp -> cyclehead == cycleheadp ) {
+	    break;
+	}
+    }
+    if ( cycletop <= 0 ) {
+	fprintf( stderr , "[dfn_findcycle] couldn't find head of cycle\n" );
+	exit( 1 );
+    }
+#   ifdef DEBUG
+	if ( debug & DFNDEBUG ) {
+	    printf( "[dfn_findcycle] dfn_depth %d cycletop %d " ,
+		    dfn_depth , cycletop  );
+	    printname( cycleheadp );
+	    printf( "\n" );
+	}
+#   endif DEBUG
+    if ( cycletop == dfn_depth ) {
+	    /*
+	     *	this is previous function, e.g. this calls itself
+	     *	sort of boring
+	     */
+	dfn_self_cycle( childp );
+    } 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 ( tailp = cycleheadp ; tailp -> cnext ; tailp = tailp -> cnext ) {
+	    /* void: chase down to tail of things already glommed */
+#	    ifdef DEBUG
+		if ( debug & DFNDEBUG ) {
+		    printf( "[dfn_findcycle] tail " );
+		    printname( tailp );
+		    printf( "\n" );
+		}
+#	    endif DEBUG
+	}
+	    /*
+	     *	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 ( cycleheadp -> cyclehead != cycleheadp ) {
+	    cycleheadp = cycleheadp -> cyclehead;
+#	    ifdef DEBUG
+		if ( debug & DFNDEBUG ) {
+		    printf( "[dfn_findcycle] new cyclehead " );
+		    printname( cycleheadp );
+		    printf( "\n" );
+		}
+#	    endif DEBUG
+	}
+	for ( index = cycletop + 1 ; index <= dfn_depth ; index += 1 ) {
+	    childp = dfn_stack[ index ].nlentryp;
+	    if ( childp -> cyclehead == childp ) {
+		    /*
+		     *	not yet glommed anywhere, glom it
+		     *	and fix any children it has glommed
+		     */
+		tailp -> cnext = childp;
+		childp -> cyclehead = cycleheadp;
+#		ifdef DEBUG
+		    if ( debug & DFNDEBUG ) {
+			printf( "[dfn_findcycle] glomming " );
+			printname( childp );
+			printf( " onto " );
+			printname( cycleheadp );
+			printf( "\n" );
+		    }
+#		endif DEBUG
+		for ( tailp = childp ; tailp->cnext ; tailp = tailp->cnext ) {
+		    tailp -> cnext -> cyclehead = cycleheadp;
+#		    ifdef DEBUG
+			if ( debug & DFNDEBUG ) {
+			    printf( "[dfn_findcycle] and its tail " );
+			    printname( tailp -> cnext );
+			    printf( " onto " );
+			    printname( cycleheadp );
+			    printf( "\n" );
+			}
+#		    endif DEBUG
+		}
+	    } else if ( childp -> cyclehead != cycleheadp /* firewall */ ) {
+		fprintf( stderr ,
+			"[dfn_busy] glommed, but not to cyclehead\n" );
+	    }
+	}
+    }
+}
+
+    /*
+     *	deal with self-cycles
+     *	for lint: ARGSUSED
+     */
+dfn_self_cycle( parentp )
+    nltype	*parentp;
+{
+	/*
+	 *	since we are taking out self-cycles elsewhere
+	 *	no need for the special case, here.
+	 */
+#   ifdef DEBUG
+	if ( debug & DFNDEBUG ) {
+	    printf( "[dfn_self_cycle] " );
+	    printname( parentp );
+	    printf( "\n" );
+	}
+#   endif DEBUG
+}
+
+    /*
+     *	visit a node after all its children
+     *	[MISSING: an explanation]
+     *	and pop it off the stack
+     */
+dfn_post_visit( parentp )
+    nltype	*parentp;
+{
+    nltype	*memberp;
+
+#   ifdef DEBUG
+	if ( debug & DFNDEBUG ) {
+	    printf( "[dfn_post_visit]\t%d: " , dfn_depth );
+	    printname( parentp );
+	    printf( "\n" );
+	}
+#   endif DEBUG
+	/*
+	 *	number functions and things in their cycles
+	 *	unless the function is itself part of a cycle
+	 */
+    if ( parentp -> cyclehead == parentp ) {
+	dfn_counter += 1;
+	for ( memberp = parentp ; memberp ; memberp = memberp -> cnext ) {
+	    memberp -> toporder = dfn_counter;
+#	    ifdef DEBUG
+		if ( debug & DFNDEBUG ) {
+		    printf( "[dfn_post_visit]\t\tmember " );
+		    printname( memberp );
+		    printf( " -> toporder = %d\n" , dfn_counter );
+		}
+#	    endif DEBUG
+	}
+    } else {
+#	ifdef DEBUG
+	    if ( debug & DFNDEBUG ) {
+		printf( "[dfn_post_visit]\t\tis part of a cycle\n" );
+	    }
+#	endif DEBUG
+    }
+    dfn_depth -= 1;
+}