allbery@uunet.UU.NET (Brandon S. Allbery - comp.sources.misc) (08/08/89)
Posting-number: Volume 7, Issue 58
Submitted-by: fnf@estinc.UUCP
Archive-name: dbug/part02
This is the latest version of my dbug package, a relatively portable and
machine independent macro based C debugging package. The dbug package
has proven to be a very flexible and useful tool for debugging, testing,
and porting C programs.
All of the features of the dbug package can be enabled or disabled
dynamically at execution time. This means that production programs will
run normally when debugging is not enabled, and eliminates the need to
maintain two separate versions of a program during testing.
Many of the things easily accomplished with conventional debugging tools,
such as symbolic debuggers, are difficult or impossible with this package,
and vice versa. Thus the dbug package should not be thought of as a
replacement or substitute for other debugging tools, but simply as a useful
addition to the program development and maintenance environment.
One of the new features with this version is stack usage accounting. You
can discover the total amount of stack used by your program, and the amount
used by each individual function. You will need to know in which direction
you stack grows (up or down).
-Fred Fish 12-Jun-89
#--------CUT---------CUT---------CUT---------CUT--------#
#########################################################
# #
# This is a shell archive file. To extract files: #
# #
# 1) Make a directory for the files. #
# 2) Write a file, such as "file.shar", containing #
# this archive file into the directory. #
# 3) Type "sh file.shar". Do not use csh. #
# #
#########################################################
#
#
echo Extracting analyze.c:
sed 's/^Z//' >analyze.c <<\STUNKYFLUFF
Z/*
Z * Analyze the profile file (cmon.out) written out by the dbug
Z * routines with profiling enabled.
Z *
Z * Copyright June 1987, Binayak Banerjee
Z * All rights reserved.
Z *
Z * This program may be freely distributed under the same terms and
Z * conditions as Fred Fish's Dbug package.
Z *
Z * Compile with -- cc -O -s -o %s analyze.c
Z *
Z * Analyze will read an trace file created by the dbug package
Z * (when run with traceing enabled). It will then produce a
Z * summary on standard output listing the name of each traced
Z * function, the number of times it was called, the percentage
Z * of total calls, the time spent executing the function, the
Z * proportion of the total time and the 'importance'. The last
Z * is a metric which is obtained by multiplying the proportions
Z * of calls and the proportions of time for each function. The
Z * greater the importance, the more likely it is that a speedup
Z * could be obtained by reducing the time taken by that function.
Z *
Z * Note that the timing values that you obtain are only rough
Z * measures. The overhead of the dbug package is included
Z * within. However, there is no need to link in special profiled
Z * libraries and the like.
Z *
Z * CHANGES:
Z *
Z * 2-Mar-89: fnf
Z * Changes to support tracking of stack usage. This required
Z * reordering the fields in the profile log file to make
Z * parsing of different record types easier. Corresponding
Z * changes made in dbug runtime library. Also used this
Z * opportunity to reformat the code more to my liking (my
Z * apologies to Binayak Banerjee for "uglifying" his code).
Z *
Z * 24-Jul-87: fnf
Z * Because I tend to use functions names like
Z * "ExternalFunctionDoingSomething", I've rearranged the
Z * printout to put the function name last in each line, so
Z * long names don't screw up the formatting unless they are
Z * *very* long and wrap around the screen width...
Z *
Z * 24-Jul-87: fnf
Z * Modified to put out table very similar to Unix profiler
Z * by default, but also puts out original verbose table
Z * if invoked with -v flag.
Z */
Z
Z#include <stdio.h>
Z#include "useful.h"
Z
Zstatic char *my_name;
Zstatic int verbose;
Z
Z/*
Z * Structure of the stack.
Z */
Z
Z#define PRO_FILE "dbugmon.out" /* Default output file name */
Z#define STACKSIZ 100 /* Maximum function nesting */
Z#define MAXPROCS 1000 /* Maximum number of function calls */
Z
Zstruct stack_t {
Z unsigned int pos; /* which function? */
Z unsigned long time; /* Time that this was entered */
Z unsigned long children; /* Time spent in called funcs */
Z};
Z
Zstatic struct stack_t fn_stack[STACKSIZ+1];
Z
Zstatic unsigned int stacktop = 0; /* Lowest stack position is a dummy */
Z
Zstatic unsigned long tot_time = 0;
Zstatic unsigned long tot_calls = 0;
Zstatic unsigned long highstack = 0;
Zstatic unsigned long lowstack = ~0;
Z
Z/*
Z * top() returns a pointer to the top item on the stack.
Z * (was a function, now a macro)
Z */
Z
Z#define top() &fn_stack[stacktop]
Z
Z/*
Z * Push - Push the given record on the stack.
Z */
Z
Zvoid push (name_pos, time_entered)
Zregister unsigned int name_pos;
Zregister unsigned long time_entered;
Z{
Z register struct stack_t *t;
Z
Z DBUG_ENTER("push");
Z if (++stacktop > STACKSIZ) {
Z fprintf (DBUG_FILE,"%s: stack overflow (%s:%d)\n",
Z my_name, __FILE__, __LINE__);
Z exit (EX_SOFTWARE);
Z }
Z DBUG_PRINT ("push", ("%d %ld",name_pos,time_entered));
Z t = &fn_stack[stacktop];
Z t -> pos = name_pos;
Z t -> time = time_entered;
Z t -> children = 0;
Z DBUG_VOID_RETURN;
Z}
Z
Z/*
Z * Pop - pop the top item off the stack, assigning the field values
Z * to the arguments. Returns 0 on stack underflow, or on popping first
Z * item off stack.
Z */
Z
Zunsigned int pop (name_pos, time_entered, child_time)
Zregister unsigned int *name_pos;
Zregister unsigned long *time_entered;
Zregister unsigned long *child_time;
Z{
Z register struct stack_t *temp;
Z register unsigned int rtnval;
Z
Z DBUG_ENTER ("pop");
Z
Z if (stacktop < 1) {
Z rtnval = 0;
Z } else {
Z temp = &fn_stack[stacktop];
Z *name_pos = temp->pos;
Z *time_entered = temp->time;
Z *child_time = temp->children;
Z DBUG_PRINT ("pop", ("%d %d %d",*name_pos,*time_entered,*child_time));
Z rtnval = stacktop--;
Z }
Z DBUG_RETURN (rtnval);
Z}
Z
Z/*
Z * We keep the function info in another array (serves as a simple
Z * symbol table)
Z */
Z
Zstruct module_t {
Z char *name;
Z unsigned long m_time;
Z unsigned long m_calls;
Z unsigned long m_stkuse;
Z};
Z
Zstatic struct module_t modules[MAXPROCS];
Z
Z/*
Z * We keep a binary search tree in order to look up function names
Z * quickly (and sort them at the end.
Z */
Z
Zstruct bnode {
Z unsigned int lchild; /* Index of left subtree */
Z unsigned int rchild; /* Index of right subtree */
Z unsigned int pos; /* Index of module_name entry */
Z};
Z
Zstatic struct bnode s_table[MAXPROCS];
Z
Zstatic unsigned int n_items = 0; /* No. of items in the array so far */
Z
Z/*
Z * Need a function to allocate space for a string and squirrel it away.
Z */
Z
Zchar *strsave (s)
Zchar *s;
Z{
Z register char *retval;
Z register unsigned int len;
Z extern char *malloc ();
Z
Z DBUG_ENTER ("strsave");
Z DBUG_PRINT ("strsave", ("%s",s));
Z if (s == Nil (char) || (len = strlen (s)) == 0) {
Z DBUG_RETURN (Nil (char));
Z }
Z MALLOC (retval, ++len, char);
Z strcpy (retval, s);
Z DBUG_RETURN (retval);
Z}
Z
Z/*
Z * add() - adds m_name to the table (if not already there), and returns
Z * the index of its location in the table. Checks s_table (which is a
Z * binary search tree) to see whether or not it should be added.
Z */
Z
Zunsigned int add (m_name)
Zchar *m_name;
Z{
Z register unsigned int ind = 0;
Z register int cmp;
Z
Z DBUG_ENTER ("add");
Z if (n_items == 0) { /* First item to be added */
Z s_table[0].pos = ind;
Z s_table[0].lchild = s_table[0].rchild = MAXPROCS;
Z addit:
Z modules[n_items].name = strsave (m_name);
Z modules[n_items].m_time = 0;
Z modules[n_items].m_calls = 0;
Z modules[n_items].m_stkuse = 0;
Z DBUG_RETURN (n_items++);
Z }
Z while (cmp = strcmp (m_name,modules[ind].name)) {
Z if (cmp < 0) { /* In left subtree */
Z if (s_table[ind].lchild == MAXPROCS) {
Z /* Add as left child */
Z if (n_items >= MAXPROCS) {
Z fprintf (DBUG_FILE,
Z "%s: Too many functions being profiled\n",
Z my_name);
Z exit (EX_SOFTWARE);
Z }
Z s_table[n_items].pos = s_table[ind].lchild = n_items;
Z s_table[n_items].lchild = s_table[n_items].rchild = MAXPROCS;
Z#ifdef notdef
Z modules[n_items].name = strsave (m_name);
Z modules[n_items].m_time = modules[n_items].m_calls = 0;
Z DBUG_RETURN (n_items++);
Z#else
Z goto addit;
Z#endif
Z
Z }
Z ind = s_table[ind].lchild; /* else traverse l-tree */
Z } else {
Z if (s_table[ind].rchild == MAXPROCS) {
Z /* Add as right child */
Z if (n_items >= MAXPROCS) {
Z fprintf (DBUG_FILE,
Z "%s: Too many functions being profiled\n",
Z my_name);
Z exit (EX_SOFTWARE);
Z }
Z s_table[n_items].pos = s_table[ind].rchild = n_items;
Z s_table[n_items].lchild = s_table[n_items].rchild = MAXPROCS;
Z#ifdef notdef
Z modules[n_items].name = strsave (m_name);
Z modules[n_items].m_time = modules[n_items].m_calls = 0;
Z DBUG_RETURN (n_items++);
Z#else
Z goto addit;
Z#endif
Z
Z }
Z ind = s_table[ind].rchild; /* else traverse r-tree */
Z }
Z }
Z DBUG_RETURN (ind);
Z}
Z
Z/*
Z * process() - process the input file, filling in the modules table.
Z */
Z
Zvoid process (inf)
ZFILE *inf;
Z{
Z char buf[BUFSIZ];
Z char fn_name[64]; /* Max length of fn_name */
Z unsigned long fn_time;
Z unsigned long fn_sbot;
Z unsigned long fn_ssz;
Z unsigned long lastuse;
Z unsigned int pos;
Z unsigned long time;
Z unsigned int oldpos;
Z unsigned long oldtime;
Z unsigned long oldchild;
Z struct stack_t *t;
Z
Z DBUG_ENTER ("process");
Z while (fgets (buf,BUFSIZ,inf) != NULL) {
Z switch (buf[0]) {
Z case 'E':
Z sscanf (buf+2, "%ld %64s", &fn_time, fn_name);
Z DBUG_PRINT ("erec", ("%ld %s", fn_time, fn_name));
Z pos = add (fn_name);
Z push (pos, fn_time);
Z break;
Z case 'X':
Z sscanf (buf+2, "%ld %64s", &fn_time, fn_name);
Z DBUG_PRINT ("xrec", ("%ld %s", fn_time, fn_name));
Z pos = add (fn_name);
Z /*
Z * An exited function implies that all stacked
Z * functions are also exited, until the matching
Z * function is found on the stack.
Z */
Z while (pop (&oldpos, &oldtime, &oldchild)) {
Z DBUG_PRINT ("popped", ("%d %d", oldtime, oldchild));
Z time = fn_time - oldtime;
Z t = top ();
Z t -> children += time;
Z DBUG_PRINT ("update", ("%s", modules[t -> pos].name));
Z DBUG_PRINT ("update", ("%d", t -> children));
Z time -= oldchild;
Z modules[oldpos].m_time += time;
Z modules[oldpos].m_calls++;
Z tot_time += time;
Z tot_calls++;
Z if (pos == oldpos) {
Z goto next_line; /* Should be a break2 */
Z }
Z }
Z /*
Z * Assume that item seen started at time 0.
Z * (True for function main). But initialize
Z * it so that it works the next time too.
Z */
Z t = top ();
Z time = fn_time - t -> time - t -> children;
Z t -> time = fn_time; t -> children = 0;
Z modules[pos].m_time += time;
Z modules[pos].m_calls++;
Z tot_time += time;
Z tot_calls++;
Z break;
Z case 'S':
Z sscanf (buf+2, "%lx %lx %64s", &fn_sbot, &fn_ssz, fn_name);
Z DBUG_PRINT ("srec", ("%lx %lx %s", fn_sbot, fn_ssz, fn_name));
Z pos = add (fn_name);
Z lastuse = modules[pos].m_stkuse;
Z#if 0
Z /*
Z * Needs further thought. Stack use is determined by
Z * difference in stack between two functions with DBUG_ENTER
Z * macros. If A calls B calls C, where A and C have the
Z * macros, and B doesn't, then B's stack use will be lumped
Z * in with either A's or C's. If somewhere else A calls
Z * C directly, the stack use will seem to change. Just
Z * take the biggest for now...
Z */
Z if (lastuse > 0 && lastuse != fn_ssz) {
Z fprintf (stderr,
Z "warning - %s stack use changed (%lx to %lx)\n",
Z fn_name, lastuse, fn_ssz);
Z }
Z#endif
Z if (fn_ssz > lastuse) {
Z modules[pos].m_stkuse = fn_ssz;
Z }
Z if (fn_sbot > highstack) {
Z highstack = fn_sbot;
Z } else if (fn_sbot < lowstack) {
Z lowstack = fn_sbot;
Z }
Z break;
Z default:
Z fprintf (stderr, "unknown record type '%s'\n", buf[0]);
Z break;
Z }
Z next_line:;
Z }
Z
Z /*
Z * Now, we've hit eof. If we still have stuff stacked, then we
Z * assume that the user called exit, so give everything the exited
Z * time of fn_time.
Z */
Z while (pop (&oldpos,&oldtime,&oldchild)) {
Z time = fn_time - oldtime;
Z t = top ();
Z t -> children += time;
Z time -= oldchild;
Z modules[oldpos].m_time += time;
Z modules[oldpos].m_calls++;
Z tot_time += time;
Z tot_calls++;
Z }
Z DBUG_VOID_RETURN;
Z}
Z
Z/*
Z * out_header () -- print out the header of the report.
Z */
Z
Zvoid out_header (outf)
ZFILE *outf;
Z{
Z DBUG_ENTER ("out_header");
Z if (verbose) {
Z fprintf (outf, "Profile of Execution\n");
Z fprintf (outf, "Execution times are in milliseconds\n\n");
Z fprintf (outf, " Calls\t\t\t Time\n");
Z fprintf (outf, " -----\t\t\t ----\n");
Z fprintf (outf, "Times\tPercentage\tTime Spent\tPercentage\n");
Z fprintf (outf, "Called\tof total\tin Function\tof total Importance\tFunction\n");
Z fprintf (outf, "======\t==========\t===========\t========== ==========\t========\t\n");
Z } else {
Z fprintf (outf, "%ld bytes of stack used, from %lx down to %lx\n\n",
Z highstack - lowstack, highstack, lowstack);
Z fprintf (outf,
Z " %%time sec #call ms/call %%calls weight stack name\n");
Z }
Z DBUG_VOID_RETURN;
Z}
Z
Z/*
Z * out_trailer () - writes out the summary line of the report.
Z */
Z
Zvoid out_trailer (outf,sum_calls,sum_time)
ZFILE *outf;
Zunsigned long int sum_calls, sum_time;
Z{
Z DBUG_ENTER ("out_trailer");
Z if (verbose) {
Z fprintf (outf, "======\t==========\t===========\t==========\t========\n");
Z fprintf (outf, "%6d\t%10.2f\t%11d\t%10.2f\t\t%-15s\n",
Z sum_calls, 100.0, sum_time, 100.0, "Totals");
Z }
Z DBUG_VOID_RETURN;
Z}
Z
Z/*
Z * out_item () - prints out the output line for a single entry,
Z * and sets the calls and time fields appropriately.
Z */
Z
Zvoid out_item (outf, m,called,timed)
ZFILE *outf;
Zregister struct module_t *m;
Zunsigned long int *called, *timed;
Z{
Z char *name = m -> name;
Z register unsigned int calls = m -> m_calls;
Z register unsigned long time = m -> m_time;
Z register unsigned long stkuse = m -> m_stkuse;
Z unsigned int import;
Z double per_time = 0.0;
Z double per_calls = 0.0;
Z double ms_per_call, ftime;
Z
Z DBUG_ENTER ("out_item");
Z
Z if (tot_time > 0) {
Z per_time = (double) (time * 100) / (double) tot_time;
Z }
Z if (tot_calls > 0) {
Z per_calls = (double) (calls * 100) / (double) tot_calls;
Z }
Z import = (unsigned int) (per_time * per_calls);
Z
Z if (verbose) {
Z fprintf (outf, "%6d\t%10.2f\t%11d\t%10.2f %10d\t%-15s\n",
Z calls, per_calls, time, per_time, import, name);
Z } else {
Z ms_per_call = time;
Z ms_per_call /= calls;
Z ftime = time;
Z ftime /= 1000;
Z fprintf (outf, "%8.2f%8.3f%8u%8.3f%8.2f%8u%8u %-s\n",
Z per_time, ftime, calls, ms_per_call, per_calls, import,
Z stkuse, name);
Z }
Z *called = calls;
Z *timed = time;
Z DBUG_VOID_RETURN;
Z}
Z
Z/*
Z * out_body (outf, root,s_calls,s_time) -- Performs an inorder traversal
Z * on the binary search tree (root). Calls out_item to actually print
Z * the item out.
Z */
Z
Zvoid out_body (outf, root,s_calls,s_time)
ZFILE *outf;
Zregister unsigned int root;
Zregister unsigned long int *s_calls, *s_time;
Z{
Z unsigned long int calls, time;
Z
Z DBUG_ENTER ("out_body");
Z DBUG_PRINT ("out_body", ("%d,%d",*s_calls,*s_time));
Z if (root == MAXPROCS) {
Z DBUG_PRINT ("out_body", ("%d,%d",*s_calls,*s_time));
Z } else {
Z while (root != MAXPROCS) {
Z out_body (outf, s_table[root].lchild,s_calls,s_time);
Z out_item (outf, &modules[s_table[root].pos],&calls,&time);
Z DBUG_PRINT ("out_body", ("-- %d -- %d --", calls, time));
Z *s_calls += calls;
Z *s_time += time;
Z root = s_table[root].rchild;
Z }
Z DBUG_PRINT ("out_body", ("%d,%d", *s_calls, *s_time));
Z }
Z DBUG_VOID_RETURN;
Z}
Z
Z/*
Z * output () - print out a nice sorted output report on outf.
Z */
Z
Zvoid output (outf)
ZFILE *outf;
Z{
Z unsigned long int sum_calls = 0;
Z unsigned long int sum_time = 0;
Z
Z DBUG_ENTER ("output");
Z if (n_items == 0) {
Z fprintf (outf, "%s: No functions to trace\n", my_name);
Z exit (EX_DATAERR);
Z }
Z out_header (outf);
Z out_body (outf, 0,&sum_calls,&sum_time);
Z out_trailer (outf, sum_calls,sum_time);
Z DBUG_VOID_RETURN;
Z}
Z
Z
Z#define usage() fprintf (DBUG_FILE,"Usage: %s [-v] [prof-file]\n",my_name)
Z
Zmain (argc, argv, environ)
Zint argc;
Zchar *argv[], *environ[];
Z{
Z extern int optind, getopt ();
Z extern char *optarg;
Z register int c;
Z int badflg = 0;
Z FILE *infile;
Z FILE *outfile = {stdout};
Z
Z DBUG_ENTER ("main");
Z DBUG_PROCESS (argv[0]);
Z my_name = argv[0];
Z while ((c = getopt (argc,argv,"#:v")) != EOF) {
Z switch (c) {
Z case '#': /* Debugging Macro enable */
Z DBUG_PUSH (optarg);
Z break;
Z case 'v': /* Verbose mode */
Z verbose++;
Z break;
Z default:
Z badflg++;
Z break;
Z }
Z }
Z if (badflg) {
Z usage ();
Z DBUG_RETURN (EX_USAGE);
Z }
Z if (optind < argc) {
Z FILEOPEN (infile, argv[optind], "r");
Z } else {
Z FILEOPEN (infile, PRO_FILE, "r");
Z }
Z process (infile);
Z output (outfile);
Z DBUG_RETURN (EX_OK);
Z}
STUNKYFLUFF
set `sum analyze.c`
if test 37177 != $1
then
echo analyze.c: Checksum error. Is: $1, should be: 37177.
fi
#
#
echo Extracting doinstall.sh:
sed 's/^Z//' >doinstall.sh <<\STUNKYFLUFF
Z
Z# Warning - first line left blank for sh/csh/ksh compatibility. Do not
Z# remove it. fnf@Unisoft
Z
Z# doinstall.sh --- figure out environment and do recursive make with
Z# appropriate pathnames. Works under SV or BSD.
Z
Zif [ -r /usr/include/search.h ]
Zthen
Z # System V
Z $* LLIB=/usr/lib
Zelse
Z # 4.2 BSD
Z $* LLIB=/usr/lib/lint
Zfi
STUNKYFLUFF
set `sum doinstall.sh`
if test 27205 != $1
then
echo doinstall.sh: Checksum error. Is: $1, should be: 27205.
fi
#
#
echo Extracting example1.c:
sed 's/^Z//' >example1.c <<\STUNKYFLUFF
Z#include <stdio.h>
Z
Zmain (argc, argv)
Zint argc;
Zchar *argv[];
Z{
Z printf ("argv[0] = %d\n", argv[0]);
Z /*
Z * Rest of program
Z */
Z printf ("== done ==\n");
Z}
STUNKYFLUFF
set `sum example1.c`
if test 12484 != $1
then
echo example1.c: Checksum error. Is: $1, should be: 12484.
fi
#
#
echo Extracting example2.c:
sed 's/^Z//' >example2.c <<\STUNKYFLUFF
Z#include <stdio.h>
Z
Zint debug = 0;
Z
Zmain (argc, argv)
Zint argc;
Zchar *argv[];
Z{
Z /* printf ("argv = %x\n", argv) */
Z if (debug) printf ("argv[0] = %d\n", argv[0]);
Z /*
Z * Rest of program
Z */
Z#ifdef DEBUG
Z printf ("== done ==\n");
Z#endif
Z}
STUNKYFLUFF
set `sum example2.c`
if test 18642 != $1
then
echo example2.c: Checksum error. Is: $1, should be: 18642.
fi
#
#
echo Extracting example3.c:
sed 's/^Z//' >example3.c <<\STUNKYFLUFF
Z#include <stdio.h>
Z
Zmain (argc, argv)
Zint argc;
Zchar *argv[];
Z{
Z# ifdef DEBUG
Z printf ("argv[0] = %d\n", argv[0]);
Z# endif
Z /*
Z * Rest of program
Z */
Z# ifdef DEBUG
Z printf ("== done ==\n");
Z# endif
Z}
STUNKYFLUFF
set `sum example3.c`
if test 15886 != $1
then
echo example3.c: Checksum error. Is: $1, should be: 15886.
fi
#
#
echo Extracting factorial.c:
sed 's/^Z//' >factorial.c <<\STUNKYFLUFF
Z#include <stdio.h>
Z/* User programs should use <local/dbug.h> */
Z#include "dbug.h"
Z
Zint factorial (value)
Zregister int value;
Z{
Z DBUG_ENTER ("factorial");
Z DBUG_PRINT ("find", ("find %d factorial", value));
Z if (value > 1) {
Z value *= factorial (value - 1);
Z }
Z DBUG_PRINT ("result", ("result is %d", value));
Z DBUG_RETURN (value);
Z}
STUNKYFLUFF
set `sum factorial.c`
if test 27082 != $1
then
echo factorial.c: Checksum error. Is: $1, should be: 27082.
fi
#
#
echo Extracting install.sh:
sed 's/^Z//' >install.sh <<\STUNKYFLUFF
Z
Z# WARNING -- first line intentionally left blank for sh/csh/ksh
Z# compatibility. Do not remove it! FNF, UniSoft Systems.
Z#
Z# Usage is:
Z# install <from> <to>
Z#
Z# The file <to> is replaced with the file <from>, after first
Z# moving <to> to a backup file. The backup file name is created
Z# by prepending the filename (after removing any leading pathname
Z# components) with "OLD".
Z#
Z# This script is currently not real robust in the face of signals
Z# or permission problems. It also does not do (by intention) all
Z# the things that the System V or BSD install scripts try to do
Z#
Z
Zif [ $# -ne 2 ]
Zthen
Z echo "usage: $0 <from> <to>"
Z exit 1
Zfi
Z
Z# Now extract the dirname and basename components. Unfortunately, BSD does
Z# not have dirname, so we do it the hard way.
Z
Zfd=`expr $1'/' : '\(/\)[^/]*/$' \| $1'/' : '\(.*[^/]\)//*[^/][^/]*//*$' \| .`
Zff=`basename $1`
Ztd=`expr $2'/' : '\(/\)[^/]*/$' \| $2'/' : '\(.*[^/]\)//*[^/][^/]*//*$' \| .`
Ztf=`basename $2`
Z
Z# Now test to make sure that they are not the same files.
Z
Zif [ $fd/$ff = $td/$tf ]
Zthen
Z echo "install: input and output are same files"
Z exit 2
Zfi
Z
Z# Save a copy of the "to" file as a backup.
Z
Zif test -f $td/$tf
Zthen
Z if test -f $td/OLD$tf
Z then
Z rm -f $td/OLD$tf
Z fi
Z mv $td/$tf $td/OLD$tf
Z if [ $? != 0 ]
Z then
Z exit 3
Z fi
Zfi
Z
Z# Now do the copy and return appropriate status
Z
Zcp $fd/$ff $td/$tf
Zif [ $? != 0 ]
Zthen
Z exit 4
Zelse
Z exit 0
Zfi
Z
STUNKYFLUFF
set `sum install.sh`
if test 46271 != $1
then
echo install.sh: Checksum error. Is: $1, should be: 46271.
fi
#
#
echo Extracting llib-ldbug:
sed 's/^Z//' >llib-ldbug <<\STUNKYFLUFF
Z/*
Z ******************************************************************************
Z * *
Z * N O T I C E *
Z * *
Z * Copyright Abandoned, 1987, Fred Fish *
Z * *
Z * *
Z * This previously copyrighted work has been placed into the public *
Z * domain by the author and may be freely used for any purpose, *
Z * private or commercial. *
Z * *
Z * Because of the number of inquiries I was receiving about the use *
Z * of this product in commercially developed works I have decided to *
Z * simply make it public domain to further its unrestricted use. I *
Z * specifically would be most happy to see this material become a *
Z * part of the standard Unix distributions by AT&T and the Berkeley *
Z * Computer Science Research Group, and a standard part of the GNU *
Z * system from the Free Software Foundation. *
Z * *
Z * I would appreciate it, as a courtesy, if this notice is left in *
Z * all copies and derivative works. Thank you. *
Z * *
Z * The author makes no warranty of any kind with respect to this *
Z * product and explicitly disclaims any implied warranties of mer- *
Z * chantability or fitness for any particular purpose. *
Z * *
Z ******************************************************************************
Z */
Z
Z
Z/*
Z * FILE
Z *
Z * llib-ldbug lint library source for debugging package
Z *
Z * SCCS ID
Z *
Z * @(#)llib-ldbug 1.9 6/12/89
Z *
Z * DESCRIPTION
Z *
Z * Function definitions for use in building lint library.
Z * Note that these must stay in syncronization with actual
Z * declarations in "dbug.c".
Z *
Z */
Z
Z
Z/*LINTLIBRARY*/
Z
Z#include <stdio.h>
Z
Z#define VOID void
Ztypedef int BOOLEAN;
Z#define FALSE 0
Z#define ARGLIST a0,a1,a2,a3,a4,a5,a6,a7,a8,a9,a10,a11,a12,a13,a14,a15
Z
Zint _db_on_ = FALSE;
Zint _db_pon_ = FALSE;
ZFILE *_db_fp_ = stderr;
ZFILE *_db_pfp_ = stderr;
Zchar *_db_process_ = "dbug";
Z
ZVOID _db_push_ (control)
Zchar *control;
Z{
Z}
Z
ZVOID _db_pop_ ()
Z{
Z}
Z
ZVOID _db_enter_ (_func_, _file_, _line_, _sfunc_, _sfile_, _slevel_, _sframep_)
Zchar *_func_;
Zchar *_file_;
Zint _line_;
Zchar **_sfunc_;
Zchar **_sfile_;
Zint *_slevel_;
Zchar ***_sframep_;
Z{
Z}
Z
ZVOID _db_return_ (_line_, _sfunc_, _sfile_, _slevel_)
Zint _line_;
Zchar **_sfunc_;
Zchar **_sfile_;
Zint *_slevel_;
Z{
Z}
Z
ZVOID _db_pargs_ (_line_, keyword)
Zint _line_;
Zchar *keyword;
Z{
Z}
Z
Z/*VARARGS1*/
ZVOID _db_doprnt_ (format, ARGLIST)
Zchar *format;
Zlong ARGLIST;
Z{
Z}
Z
Z/* WARNING -- the following function is obsolete and may not be supported */
Z/* in future releases... */
Z
Z/*VARARGS3*/
ZVOID _db_printf_ (_line_, keyword, format, ARGLIST)
Zint _line_;
Zchar *keyword, *format;
Zlong ARGLIST;
Z{
Z}
Z
ZBOOLEAN _db_keyword_ (keyword)
Zchar *keyword;
Z{
Z return (0);
Z}
Z
ZVOID _db_longjmp_ ()
Z{
Z}
Z
ZVOID _db_setjmp_ ()
Z{
Z}
STUNKYFLUFF
set `sum llib-ldbug`
if test 20072 != $1
then
echo llib-ldbug: Checksum error. Is: $1, should be: 20072.
fi
#
#
echo Extracting main.c:
sed 's/^Z//' >main.c <<\STUNKYFLUFF
Z#include <stdio.h>
Z/* User programs should use <local/dbug.h> */
Z#include "dbug.h"
Z
Zmain (argc, argv)
Zint argc;
Zchar *argv[];
Z{
Z register int result, ix;
Z extern int factorial (), atoi ();
Z
Z DBUG_ENTER ("main");
Z DBUG_PROCESS (argv[0]);
Z for (ix = 1; ix < argc && argv[ix][0] == '-'; ix++) {
Z switch (argv[ix][1]) {
Z case '#':
Z DBUG_PUSH (&(argv[ix][2]));
Z break;
Z }
Z }
Z for (; ix < argc; ix++) {
Z DBUG_PRINT ("args", ("argv[%d] = %s", ix, argv[ix]));
Z result = factorial (atoi (argv[ix]));
Z printf ("%d\n", result);
Z }
Z DBUG_RETURN (0);
Z}
STUNKYFLUFF
set `sum main.c`
if test 42153 != $1
then
echo main.c: Checksum error. Is: $1, should be: 42153.
fi
#
#
echo Extracting mklintlib.sh:
sed 's/^Z//' >mklintlib.sh <<\STUNKYFLUFF
Z
Z# Warning - first line left blank for sh/csh/ksh compatibility. Do not
Z# remove it. fnf@Unisoft
Z
Z# mklintlib --- make a lint library, under either System V or 4.2 BSD
Z#
Z# usage: mklintlib <infile> <outfile>
Z#
Z
Zif test $# -ne 2
Zthen
Z echo "usage: mklintlib <infile> <outfile>"
Z exit 1
Zfi
Z
Zif grep SIGTSTP /usr/include/signal.h >/dev/null
Zthen # BSD
Z if test -r /usr/include/whoami.h # 4.1
Z then
Z /lib/cpp -C -Dlint $1 >hlint
Z (/usr/lib/lint/lint1 <hlint >$2) 2>&1 | grep -v warning
Z else # 4.2
Z lint -Cxxxx $1
Z mv llib-lxxxx.ln $2
Z fi
Zelse # USG
Z cc -E -C -Dlint $1 | /usr/lib/lint1 -vx -Hhlint >$2
Z rm -f hlint
Zfi
Zexit 0 # don't kill make
STUNKYFLUFF
set `sum mklintlib.sh`
if test 51376 != $1
then
echo mklintlib.sh: Checksum error. Is: $1, should be: 51376.
fi
#
#
echo Extracting ranlib.sh:
sed 's/^Z//' >ranlib.sh <<\STUNKYFLUFF
Z
Z# Warning - first line left blank for sh/csh/ksh compatibility. Do not
Z# remove it. fnf@Unisoft
Z
Z# ranlib --- do a ranlib if necessary
Z
Zif [ -x /usr/bin/ranlib ]
Zthen
Z /usr/bin/ranlib $*
Zelif [ -x /bin/ranlib ]
Zthen
Z /bin/ranlib $*
Zelse
Z :
Zfi
STUNKYFLUFF
set `sum ranlib.sh`
if test 20181 != $1
then
echo ranlib.sh: Checksum error. Is: $1, should be: 20181.
fi
#
#
echo Extracting useful.h:
sed 's/^Z//' >useful.h <<\STUNKYFLUFF
Z/*
Z * Copyright June 1987, Binayak Banerjee
Z * All rights reserved.
Z *
Z * This program may be freely distributed under the same terms and
Z * conditions as Fred Fish's Dbug package.
Z *
Z * Useful macros which I use a lot.
Z *
Z * Conditionally include some useful files.
Z */
Z
Z# ifndef EOF
Z# include <stdio.h>
Z# endif
Z
Z/*
Z * For BSD systems, you can include <sysexits.h> for more detailed
Z * exit information. For non-BSD systems (which also includes
Z * non-unix systems) just map everything to "failure" = 1 and
Z * "success" = 0. -Fred Fish 9-Sep-87
Z */
Z
Z# ifdef BSD
Z# include <sysexits.h>
Z# else
Z# define EX_SOFTWARE 1
Z# define EX_DATAERR 1
Z# define EX_USAGE 1
Z# define EX_OSERR 1
Z# define EX_IOERR 1
Z# define EX_OK 0
Z# endif
Z
Z
Z/*
Z * Fred Fish's debugging stuff. Define DBUG_OFF in order to disable if
Z * you don't have these.
Z */
Z
Z# ifndef DBUG_OFF
Z# include "dbug.h" /* Use local version */
Z# else
Z# define DBUG_ENTER(a1)
Z# define DBUG_RETURN(a1) return(a1)
Z# define DBUG_VOID_RETURN return
Z# define DBUG_EXECUTE(keyword,a1)
Z# define DBUG_2(keyword,format)
Z# define DBUG_3(keyword,format,a1)
Z# define DBUG_4(keyword,format,a1,a2)
Z# define DBUG_5(keyword,format,a1,a2,a3)
Z# define DBUG_PUSH(a1)
Z# define DBUG_POP()
Z# define DBUG_PROCESS(a1)
Z# define DBUG_PRINT(x,y)
Z# define DBUG_FILE (stderr)
Z# endif
Z
Z#define __MERF_OO_ "%s: Malloc Failed in %s: %d\n"
Z
Z#define Nil(Typ) ((Typ *) 0) /* Make Lint happy */
Z
Z#define MALLOC(Ptr,Num,Typ) do /* Malloc w/error checking & exit */ \
Z if ((Ptr = (Typ *)malloc((Num)*(sizeof(Typ)))) == Nil(Typ)) \
Z {fprintf(stderr,__MERF_OO_,my_name,__FILE__,__LINE__);\
Z exit(EX_OSERR);} while(0)
Z
Z#define Malloc(Ptr,Num,Typ) do /* Weaker version of above */\
Z if ((Ptr = (Typ *)malloc((Num)*(sizeof(Typ)))) == Nil(Typ)) \
Z fprintf(stderr,__MERF_OO_,my_name,__FILE__,__LINE__);\
Z while(0)
Z
Z#define FILEOPEN(Fp,Fn,Mod) do /* File open with error exit */ \
Z if((Fp = fopen(Fn,Mod)) == Nil(FILE))\
Z {fprintf(stderr,"%s: Couldn't open %s\n",my_name,Fn);\
Z exit(EX_IOERR);} while(0)
Z
Z#define Fileopen(Fp,Fn,Mod) do /* Weaker version of above */ \
Z if((Fp = fopen(Fn,Mod)) == Nil(FILE)) \
Z fprintf(stderr,"%s: Couldn't open %s\n",my_name,Fn);\
Z while(0)
Z
Z
Zextern char *my_name; /* The name that this was called as */
STUNKYFLUFF
set `sum useful.h`
if test 45206 != $1
then
echo useful.h: Checksum error. Is: $1, should be: 45206.
fi
#
#
echo Extracting user.r:
sed 's/^Z//' >user.r <<\STUNKYFLUFF
Z.\" @(#)user.r 1.16 8/7/88
Z.\"
Z.\" DBUG (Macro Debugger Package) nroff source
Z.\"
Z.\" nroff -mm user.r >user.t
Z.\"
Z.\" ===================================================
Z.\"
Z.\" === Some sort of black magic, but I forget...
Z.tr ~
Z.\" === Hyphenation control (1 = on)
Z.\".nr Hy 1
Z.\" === Force all first level headings to start on new page
Z.nr Ej 1
Z.\" === Set for breaks after headings for levels 1-3
Z.nr Hb 3
Z.\" === Set for space after headings for levels 1-3
Z.nr Hs 3
Z.\" === Set standard indent for one/half inch
Z.nr Si 10
Z.\" === Set page header
Z.PH "/DBUG User Manual//\*(DT/"
Z.\" === Set page footer
Z.PF "// - % - //"
Z.\" === Set page offset
Z.\".po 0.60i
Z.\" === Set line length
Z.\".ll 6.5i
Z.TL
ZD B U G
Z.P 0
ZC Program Debugging Package
Z.P 0
Zby
Z.AU "Fred Fish"
Z.AF ""
Z.SA 1
Z.\" === All paragraphs indented.
Z.nr Pt 1
Z.AS 1
ZThis document introduces
Z.I dbug ,
Za macro based C debugging
Zpackage which has proven to be a very flexible and useful tool
Zfor debugging, testing, and porting C programs.
Z
Z.P
ZAll of the features of the
Z.I dbug
Zpackage can be enabled or disabled dynamically at execution time.
ZThis means that production programs will run normally when
Zdebugging is not enabled, and eliminates the need to maintain two
Zseparate versions of a program.
Z
Z.P
ZMany of the things easily accomplished with conventional debugging
Ztools, such as symbolic debuggers, are difficult or impossible with this
Zpackage, and vice versa.
ZThus the
Z.I dbug
Zpackage should
Z.I not
Zbe thought of as a replacement or substitute for
Zother debugging tools, but simply as a useful
Z.I addition
Zto the
Zprogram development and maintenance environment.
Z
Z.AE
Z.MT 4
Z.SK
Z.B
ZINTRODUCTION
Z.R
Z
Z.P
ZAlmost every program development environment worthy of the name
Zprovides some sort of debugging facility.
ZUsually this takes the form of a program which is capable of
Zcontrolling execution of other programs and examining the internal
Zstate of other executing programs.
ZThese types of programs will be referred to as external debuggers
Zsince the debugger is not part of the executing program.
ZExamples of this type of debugger include the
Z.B adb
Zand
Z.B sdb
Zdebuggers provided with the
Z.B UNIX\*F
Z.FS
ZUNIX is a trademark of AT&T Bell Laboratories.
Z.FE
Zoperating system.
Z
Z.P
ZOne of the problems associated with developing programs in an environment
Zwith good external debuggers is that developed programs tend to have
Zlittle or no internal instrumentation.
ZThis is usually not a problem for the developer since he is,
Zor at least should be, intimately familiar with the internal organization,
Zdata structures, and control flow of the program being debugged.
ZIt is a serious problem for maintenance programmers, who
Zare unlikely to have such familiarity with the program being
Zmaintained, modified, or ported to another environment.
ZIt is also a problem, even for the developer, when the program is
Zmoved to an environment with a primitive or unfamiliar debugger,
Zor even no debugger.
Z
Z.P
ZOn the other hand,
Z.I dbug
Zis an example of an internal debugger.
ZBecause it requires internal instrumentation of a program,
Zand its usage does not depend on any special capabilities of
Zthe execution environment, it is always available and will
Zexecute in any environment that the program itself will
Zexecute in.
ZIn addition, since it is a complete package with a specific
Zuser interface, all programs which use it will be provided
Zwith similar debugging capabilities.
ZThis is in sharp contrast to other forms of internal instrumentation
Zwhere each developer has their own, usually less capable, form
Zof internal debugger.
ZIn summary,
Zbecause
Z.I dbug
Zis an internal debugger it provides consistency across operating
Zenvironments,
Zand because it is available to all developers it provides
Zconsistency across all programs in the same environment.
Z
Z.P
ZThe
Z.I dbug
Zpackage imposes only a slight speed penalty on executing
Zprograms, typically much less than 10 percent, and a modest size
Zpenalty, typically 10 to 20 percent.
ZBy defining a specific C preprocessor symbol both of these
Zcan be reduced to zero with no changes required to the
Zsource code.
Z
Z.P
ZThe following list is a quick summary of the capabilities
Zof the
Z.I dbug
Zpackage.
ZEach capability can be individually enabled or disabled
Zat the time a program is invoked by specifying the appropriate
Zcommand line arguments.
Z.SP 1
Z.ML o 1i
Z.LI
ZExecution trace showing function level control flow in a
Zsemi-graphically manner using indentation to indicate nesting
Zdepth.
Z.LI
ZOutput the values of all, or any subset of, key internal variables.
Z.LI
ZLimit actions to a specific set of named functions.
Z.LI
ZLimit function trace to a specified nesting depth.
Z.LI
ZLabel each output line with source file name and line number.
Z.LI
ZLabel each output line with name of current process.
Z.LI
ZPush or pop internal debugging state to allow execution with
Zbuilt in debugging defaults.
Z.LI
ZRedirect the debug output stream to standard output (stdout)
Zor a named file.
ZThe default output stream is standard error (stderr).
ZThe redirection mechanism is completely independent of
Znormal command line redirection to avoid output conflicts.
Z.LE
Z
Z.SK
Z.B
ZPRIMITIVE DEBUGGING TECHNIQUES
Z.R
Z
Z.P
ZInternal instrumentation is already a familiar concept
Zto most programmers, since it is usually the first debugging
Ztechnique learned.
ZTypically, "print\ statements" are inserted in the source
Zcode at interesting points, the code is recompiled and executed,
Zand the resulting output is examined in an attempt to determine
Zwhere the problem is.
Z
ZThe procedure is iterative, with each iteration yielding more
Zand more output, and hopefully the source of the problem is
Zdiscovered before the output becomes too large to deal with
Zor previously inserted statements need to be removed.
ZFigure 1 is an example of this type of primitive debugging
Ztechnique.
Z.DS I N
Z.SP 2
Z.so example1.r
Z.SP 2
Z.ll -5
Z.ce
ZFigure 1
Z.ce
ZPrimitive Debugging Technique
Z.ll +5
Z.SP 2
Z.DE
Z
Z.P
ZEventually, and usually after at least several iterations, the
Zproblem will be found and corrected.
ZAt this point, the newly inserted print statements must be
Zdealt with.
ZOne obvious solution is to simply delete them all.
ZBeginners usually do this a few times until they have to
Zrepeat the entire process every time a new bug pops up.
ZThe second most obvious solution is to somehow disable
Zthe output, either through the source code comment facility,
Zcreation of a debug variable to be switched on or off, or by using the
ZC preprocessor.
ZFigure 2 is an example of all three techniques.
Z.DS I N
Z.SP 2
Z.so example2.r
Z.SP 2
Z.ll -5
Z.ce
ZFigure 2
Z.ce
ZDebug Disable Techniques
Z.ll +5
Z.SP 2
Z.DE
Z
Z.P
ZEach technique has its advantages and disadvantages with respect
Zto dynamic vs static activation, source code overhead, recompilation
Zrequirements, ease of use, program readability, etc.
ZOveruse of the preprocessor solution quickly leads to problems with
Zsource code readability and maintainability when multiple
Z.B #ifdef
Zsymbols are to be defined or undefined based on specific types
Zof debug desired.
ZThe source code can be made slightly more readable by suitable indentation
Zof the
Z.B #ifdef
Zarguments to match the indentation of the code, but
Znot all C preprocessors allow this.
ZThe only requirement for the standard
Z.B UNIX
ZC preprocessor is for the '#' character to appear
Zin the first column, but even this seems
Zlike an arbitrary and unreasonable restriction.
ZFigure 3 is an example of this usage.
Z.DS I N
Z.SP 2
Z.so example3.r
Z.SP 2
Z.ll -5
Z.ce
ZFigure 3
Z.ce
ZMore Readable Preprocessor Usage
Z.ll +5
Z.SP 2
Z.DE
Z
Z.SK
Z.B
ZFUNCTION TRACE EXAMPLE
Z.R
Z
Z.P
ZWe will start off learning about the capabilities of the
Z.I dbug
Zpackage by using a simple minded program which computes the
Zfactorial of a number.
ZIn order to better demonstrate the function trace mechanism, this
Zprogram is implemented recursively.
ZFigure 4 is the main function for this factorial program.
Z.DS I N
Z.SP 2
Z.so main.r
Z.SP 2
Z.ll -5
Z.ce
ZFigure 4
Z.ce
ZFactorial Program Mainline
Z.ll +5
Z.SP 2
Z.DE
Z
Z.P
ZThe
Z.B main
Zfunction is responsible for processing any command line
Zoption arguments and then computing and printing the factorial of
Zeach non-option argument.
Z.P
ZFirst of all, notice that all of the debugger functions are implemented
Zvia preprocessor macros.
ZThis does not detract from the readability of the code and makes disabling
Zall debug compilation trivial (a single preprocessor symbol,
Z.B DBUG_OFF ,
Zforces the macro expansions to be null).
Z.P
ZAlso notice the inclusion of the header file
Z.B dbug.h
Zfrom the local header file directory.
Z(The version included here is the test version in the dbug source
Zdistribution directory).
ZThis file contains all the definitions for the debugger macros, which
Zall have the form
Z.B DBUG_XX...XX .
Z
Z.P
ZThe
Z.B DBUG_ENTER
Zmacro informs that debugger that we have entered the
Zfunction named
Z.B main .
ZIt must be the very first "executable" line in a function, after
Zall declarations and before any other executable line.
ZThe
Z.B DBUG_PROCESS
Zmacro is generally used only once per program to
Zinform the debugger what name the program was invoked with.
ZThe
Z.B DBUG_PUSH
Zmacro modifies the current debugger state by
Zsaving the previous state and setting a new state based on the
Zcontrol string passed as its argument.
ZThe
Z.B DBUG_PRINT
Zmacro is used to print the values of each argument
Zfor which a factorial is to be computed.
ZThe
Z.B DBUG_RETURN
Zmacro tells the debugger that the end of the current
Zfunction has been reached and returns a value to the calling
Zfunction.
ZAll of these macros will be fully explained in subsequent sections.
Z.P
ZTo use the debugger, the factorial program is invoked with a command
Zline of the form:
Z.DS CB N
Zfactorial -#d:t 1 2 3
Z.DE
ZThe
Z.B main
Zfunction recognizes the "-#d:t" string as a debugger control
Zstring, and passes the debugger arguments ("d:t") to the
Z.I dbug
Zruntime support routines via the
Z.B DBUG_PUSH
Zmacro.
ZThis particular string enables output from the
Z.B DBUG_PRINT
Zmacro with the 'd' flag and enables function tracing with the 't' flag.
ZThe factorial function is then called three times, with the arguments
Z"1", "2", and "3".
ZNote that the DBUG_PRINT takes exactly
Z.B two
Zarguments, with the second argument (a format string and list
Zof printable values) enclosed in parenthesis.
Z.P
ZDebug control strings consist of a header, the "-#", followed
Zby a colon separated list of debugger arguments.
ZEach debugger argument is a single character flag followed
Zby an optional comma separated list of arguments specific
Zto the given flag.
ZSome examples are:
Z.DS CB N
Z-#d:t:o
Z-#d,in,out:f,main:F:L
Z.DE
ZNote that previously enabled debugger actions can be disabled by the
Zcontrol string "-#".
Z
Z.P
ZThe definition of the factorial function, symbolized as "N!", is
Zgiven by:
Z.DS CB N
ZN! = N * N-1 * ... 2 * 1
Z.DE
ZFigure 5 is the factorial function which implements this algorithm
Zrecursively.
ZNote that this is not necessarily the best way to do factorials
Zand error conditions are ignored completely.
Z.DS I N
Z.SP 2
Z.so factorial.r
Z.SP 2
Z.ll -5
Z.ce
ZFigure 5
Z.ce
ZFactorial Function
Z.ll +5
Z.SP 2
Z.DE
Z
Z.P
ZOne advantage (some may not consider it so) to using the
Z.I dbug
Zpackage is that it strongly encourages fully structured coding
Zwith only one entry and one exit point in each function.
ZMultiple exit points, such as early returns to escape a loop,
Zmay be used, but each such point requires the use of an
Zappropriate
Z.B DBUG_RETURN
Zor
Z.B DBUG_VOID_RETURN
Zmacro.
Z
Z.P
ZTo build the factorial program on a
Z.B UNIX
Zsystem, compile and
Zlink with the command:
Z.DS CB N
Zcc -o factorial main.c factorial.c -ldbug
Z.DE
ZThe "-ldbug" argument tells the loader to link in the
Zruntime support modules for the
Z.I dbug
Zpackage.
ZExecuting the factorial program with a command of the form:
Z.DS CB N
Zfactorial 1 2 3 4 5
Z.DE
Zgenerates the output shown in figure 6.
Z.DS I N
Z.SP 2
Z.so output1.r
Z.SP 2
Z.ll -5
Z.ce
ZFigure 6
Z.ce
Zfactorial 1 2 3 4 5
Z.ll +5
Z.SP 2
Z.DE
Z
Z.P
ZFunction level tracing is enabled by passing the debugger
Zthe 't' flag in the debug control string.
ZFigure 7 is the output resulting from the command
Z"factorial\ -#t:o\ 3\ 2".
Z.DS I N
Z.SP 2
Z.so output2.r
Z.SP 2
Z.ll -5
Z.ce
ZFigure 7
Z.ce
Zfactorial -#t:o 3 2
Z.ll +5
Z.SP 2
Z.DE
Z
Z.P
ZEach entry to or return from a function is indicated by '>' for the
Zentry point and '<' for the exit point, connected by
Zvertical bars to allow matching points to be easily found
Zwhen separated by large distances.
Z
Z.P
ZThis trace output indicates that there was an initial call
Zto factorial from main (to compute 2!), followed by
Za single recursive call to factorial to compute 1!.
ZThe main program then output the result for 2! and called the
Zfactorial function again with the second argument, 3.
ZFactorial called itself recursively to compute 2! and 1!, then
Zreturned control to main, which output the value for 3! and exited.
Z
Z.P
ZNote that there is no matching entry point "main>" for the
Zreturn point "<main" because at the time the
Z.B DBUG_ENTER
Zmacro was reached in main, tracing was not enabled yet.
ZIt was only after the macro
Z.B DBUG_PUSH
Zwas executing that tracing became enabled.
ZThis implies that the argument list should be processed as early as
Zpossible since all code preceding the first call to
Z.B DBUG_PUSH
Zis
Zessentially invisible to
Z.B dbug
Z(this can be worked around by
Zinserting a temporary
Z.B DBUG_PUSH(argv[1])
Zimmediately after the
Z.B DBUG_ENTER("main")
Zmacro.
Z
Z.P
ZOne last note,
Zthe trace output normally comes out on the standard error.
ZSince the factorial program prints its result on the standard
Zoutput, there is the possibility of the output on the terminal
Zbeing scrambled if the two streams are not synchronized.
ZThus the debugger is told to write its output on the standard
Zoutput instead, via the 'o' flag character.
ZNote that no 'o' implies the default (standard error), a 'o'
Zwith no arguments means standard output, and a 'o'
Zwith an argument means used the named file.
ZI.E, "factorial\ -#t:o,logfile\ 3\ 2" would write the trace
Zoutput in "logfile".
ZBecause of
Z.B UNIX
Zimplementation details, programs usually run
Zfaster when writing to stdout rather than stderr, though this
Zis not a prime consideration in this example.
Z
Z.SK
Z.B
ZUSE OF DBUG_PRINT MACRO
Z.R
Z
Z.P
ZThe mechanism used to produce "printf" style output is the
Z.B DBUG_PRINT
Zmacro.
Z
Z.P
ZTo allow selection of output from specific macros, the first argument
Zto every
Z.B DBUG_PRINT
Zmacro is a
Z.I dbug
Zkeyword.
ZWhen this keyword appears in the argument list of the 'd' flag in
Za debug control string, as in "-#d,keyword1,keyword2,...:t",
Zoutput from the corresponding macro is enabled.
ZThe default when there is no 'd' flag in the control string is to
Zenable output from all
Z.B DBUG_PRINT
Zmacros.
Z
Z.P
ZTypically, a program will be run once, with no keywords specified,
Zto determine what keywords are significant for the current problem
Z(the keywords are printed in the macro output line).
ZThen the program will be run again, with the desired keywords,
Zto examine only specific areas of interest.
Z
Z.P
ZThe second argument to a
Z.B DBUG_PRINT
Zmacro is a standard printf style
Zformat string and one or more arguments to print, all
Zenclosed in parenthesis so that they collectively become a single macro
Zargument.
ZThis is how variable numbers of printf arguments are supported.
ZAlso note that no explicit newline is required at the end of the format string.
ZAs a matter of style, two or three small
Z.B DBUG_PRINT
Zmacros are preferable
Zto a single macro with a huge format string.
ZFigure 8 shows the output for default tracing and debug.
Z.DS I N
Z.SP 2
Z.so output3.r
Z.SP 2
Z.ll -5
Z.ce
ZFigure 8
Z.ce
Zfactorial -#d:t:o 3
Z.ll +5
Z.SP 2
Z.DE
Z
Z.P
ZThe output from the
Z.B DBUG_PRINT
Zmacro is indented to match the trace output
Zfor the function in which the macro occurs.
ZWhen debugging is enabled, but not trace, the output starts at the left
Zmargin, without indentation.
Z
Z.P
ZTo demonstrate selection of specific macros for output, figure
Z9 shows the result when the factorial program is invoked with
Zthe debug control string "-#d,result:o".
Z.DS I N
Z.SP 2
Z.so output4.r
Z.SP 2
Z.ll -5
Z.ce
ZFigure 9
Z.ce
Zfactorial -#d,result:o 4
Z.ll +5
Z.SP 2
Z.DE
Z
Z.P
ZIt is sometimes desirable to restrict debugging and trace actions
Zto a specific function or list of functions.
ZThis is accomplished with the 'f' flag character in the debug
Zcontrol string.
ZFigure 10 is the output of the factorial program when run with the
Zcontrol string "-#d:f,factorial:F:L:o".
ZThe 'F' flag enables printing of the source file name and the 'L'
Zflag enables printing of the source file line number.
Z.DS I N
Z.SP 2
Z.so output5.r
Z.SP 2
Z.ll -5
Z.ce
ZFigure 10
Z.ce
Zfactorial -#d:f,factorial:F:L:o 3
Z.ll +5
Z.SP 2
Z.DE
Z
Z.P
ZThe output in figure 10 shows that the "find" macro is in file
Z"factorial.c" at source line 8 and the "result" macro is in the same
Zfile at source line 12.
Z
Z.SK
Z.B
ZSUMMARY OF MACROS
Z.R
Z
Z.P
ZThis section summarizes the usage of all currently defined macros
Zin the
Z.I dbug
Zpackage.
ZThe macros definitions are found in the user include file
Z.B dbug.h
Zfrom the standard include directory.
Z
Z.SP 2
Z.BL 20
Z.LI DBUG_ENTER\
ZUsed to tell the runtime support module the name of the function
Zbeing entered.
ZThe argument must be of type "pointer to character".
ZThe
ZDBUG_ENTER
Zmacro must precede all executable lines in the
Zfunction just entered, and must come after all local declarations.
ZEach
ZDBUG_ENTER
Zmacro must have a matching
ZDBUG_RETURN
Zor
ZDBUG_VOID_RETURN
Zmacro
Zat the function exit points.
ZDBUG_ENTER
Zmacros used without a matching
ZDBUG_RETURN
Zor
ZDBUG_VOID_RETURN
Zmacro
Zwill cause warning messages from the
Z.I dbug
Zpackage runtime support module.
Z.SP 1
ZEX:\ DBUG_ENTER\ ("main");
Z.SP 1
Z.LI DBUG_RETURN\
ZUsed at each exit point of a function containing a
ZDBUG_ENTER
Zmacro
Zat the entry point.
ZThe argument is the value to return.
ZFunctions which return no value (void) should use the
ZDBUG_VOID_RETURN
Zmacro.
ZIt
Zis an error to have a
ZDBUG_RETURN
Zor
ZDBUG_VOID_RETURN
Zmacro in a function
Zwhich has no matching
ZDBUG_ENTER
Zmacro, and the compiler will complain
Zif the macros are actually used (expanded).
Z.SP 1
ZEX:\ DBUG_RETURN\ (value);
Z.br
ZEX:\ DBUG_VOID_RETURN;
Z.SP 1
Z.LI DBUG_PROCESS\
ZUsed to name the current process being executed.
ZA typical argument for this macro is "argv[0]", though
Zit will be perfectly happy with any other string.
Z.SP 1
ZEX:\ DBUG_PROCESS\ (argv[0]);
Z.SP 1
Z.LI DBUG_PUSH\
ZSets a new debugger state by pushing the current
Z.B dbug
Zstate onto an
Zinternal stack and setting up the new state using the debug control
Zstring passed as the macro argument.
ZThe most common usage is to set the state specified by a debug
Zcontrol string retrieved from the argument list.
ZNote that the leading "-#" in a debug control string specified
Zas a command line argument must
Z.B not
Zbe passed as part of the macro argument.
ZThe proper usage is to pass a pointer to the first character
Z.B after
Zthe "-#" string.
Z.SP 1
ZEX:\ DBUG_PUSH\ (\&(argv[i][2]));
Z.br
ZEX:\ DBUG_PUSH\ ("d:t");
Z.br
ZEX:\ DBUG_PUSH\ ("");
Z.SP 1
Z.LI DBUG_POP\
ZRestores the previous debugger state by popping the state stack.
ZAttempting to pop more states than pushed will be ignored and no
Zwarning will be given.
ZThe
ZDBUG_POP
Zmacro has no arguments.
Z.SP 1
ZEX:\ DBUG_POP\ ();
Z.SP 1
Z.LI DBUG_FILE\
ZThe
ZDBUG_FILE
Zmacro is used to do explicit I/O on the debug output
Zstream.
ZIt is used in the same manner as the symbols "stdout" and "stderr"
Zin the standard I/O package.
Z.SP 1
ZEX:\ fprintf\ (DBUG_FILE,\ "Doing my own I/O!\n");
Z.SP 1
Z.LI DBUG_EXECUTE\
ZThe DBUG_EXECUTE macro is used to execute any arbitrary C code.
ZThe first argument is the debug keyword, used to trigger execution
Zof the code specified as the second argument.
ZThis macro must be used cautiously because, like the
ZDBUG_PRINT
Zmacro,
Zit is automatically selected by default whenever the 'd' flag has
Zno argument list (I.E., a "-#d:t" control string).
Z.SP 1
ZEX:\ DBUG_EXECUTE\ ("abort",\ abort\ ());
Z.SP 1
Z.LI DBUG_N\
ZThese macros, where N is in the range 2-5, are currently obsolete
Zand will be removed in a future release.
ZUse the new DBUG_PRINT macro.
Z.LI DBUG_PRINT\
ZUsed to do printing via the "fprintf" library function on the
Zcurrent debug stream,
ZDBUG_FILE.
ZThe first argument is a debug keyword, the second is a format string
Zand the corresponding argument list.
ZNote that the format string and argument list are all one macro argument
Zand
Z.B must
Zbe enclosed in parenthesis.
Z.SP 1
ZEX:\ DBUG_PRINT\ ("eof",\ ("end\ of\ file\ found"));
Z.br
ZEX:\ DBUG_PRINT\ ("type",\ ("type\ is\ %x", type));
Z.br
ZEX:\ DBUG_PRINT\ ("stp",\ ("%x\ ->\ %s", stp, stp\ ->\ name));
Z.LI DBUG_SETJMP\
ZUsed in place of the setjmp() function to first save the current
Zdebugger state and then execute the standard setjmp call.
ZThis allows the debugger to restore its state when the
ZDBUG_LONGJMP macro is used to invoke the standard longjmp() call.
ZCurrently all instances of DBUG_SETJMP must occur within the
Zsame function and at the same function nesting level.
Z.SP 1
ZEX:\ DBUG_SETJMP\ (env);
Z.LI DBUG_LONGJMP\
ZUsed in place of the longjmp() function to first restore the
Zprevious debugger state at the time of the last DBUG_SETJMP
Zand then execute the standard longjmp() call.
ZNote that currently all DBUG_LONGJMP macros restore the state
Zat the time of the last DBUG_SETJMP.
ZIt would be possible to maintain separate DBUG_SETJMP and DBUG_LONGJMP
Zpairs by having the debugger runtime support module use the first
Zargument to differentiate the pairs.
Z.SP 1
ZEX:\ DBUG_LONGJMP\ (env,val);
Z.LE
Z
Z.SK
Z.B
ZDEBUG CONTROL STRING
Z.R
Z
Z.P
ZThe debug control string is used to set the state of the debugger
Zvia the
Z.B DBUG_PUSH
Zmacro.
ZThis section summarizes the currently available debugger options
Zand the flag characters which enable or disable them.
ZArgument lists enclosed in '[' and ']' are optional.
Z.SP 2
Z.BL 22
Z.LI d[,keywords]
ZEnable output from macros with specified keywords.
ZA null list of keywords implies that all keywords are selected.
Z.LI D[,time]
ZDelay for specified time after each output line, to let output drain.
ZTime is given in tenths of a second (value of 10 is one second).
ZDefault is zero.
Z.LI f[,functions]
ZLimit debugger actions to the specified list of functions.
ZA null list of functions implies that all functions are selected.
Z.LI F
ZMark each debugger output line with the name of the source file
Zcontaining the macro causing the output.
Z.LI g
ZTurn on machine independent profiling.
ZA profiling data collection file, named dbugmon.out, will be written
Zfor postprocessing by the "analyze" program.
ZThe accuracy of this feature is relatively unknown at this time.
Z.LI i
ZIdentify the process emitting each line of debug or trace output
Zwith the process id for that process.
Z.LI L
ZMark each debugger output line with the source file line number of
Zthe macro causing the output.
Z.LI n
ZMark each debugger output line with the current function nesting depth.
Z.LI N
ZSequentially number each debugger output line starting at 1.
ZThis is useful for reference purposes when debugger output is
Zinterspersed with program output.
Z.LI o[,file]
ZRedirect the debugger output stream to the specified file.
ZThe default output stream is stderr.
ZA null argument list causes output to be redirected to stdout.
Z.LI p[,processes]
ZLimit debugger actions to the specified processes.
ZA null list implies all processes.
ZThis is useful for processes which run child processes.
ZNote that each debugger output line can be marked with the name of
Zthe current process via the 'P' flag.
ZThe process name must match the argument passed to the
Z.B DBUG_PROCESS
Zmacro.
Z.LI P
ZMark each debugger output line with the name of the current process
Zfrom argv[0].
ZMost useful when used with a process which runs child processes that
Zare also being debugged.
ZNote that the parent process must arrange for the debugger control
Zstring to be passed to the child processes.
Z.LI r
ZUsed in conjunction with the
Z.B DBUG_PUSH
Zmacro to reset the current
Zindentation level back to zero.
ZMost useful with
Z.B DBUG_PUSH
Zmacros used to temporarily alter the
Zdebugger state.
Z.LI t[,N]
ZEnable function control flow tracing.
ZThe maximum nesting depth is specified by N, and defaults to
Z200.
Z.LE
Z.SK
Z.B
ZHINTS AND MISCELLANEOUS
Z.R
Z
Z.P
ZOne of the most useful capabilities of the
Z.I dbug
Zpackage is to compare the executions of a given program in two
Zdifferent environments.
ZThis is typically done by executing the program in the environment
Zwhere it behaves properly and saving the debugger output in a
Zreference file.
ZThe program is then run with identical inputs in the environment where
Zit misbehaves and the output is again captured in a reference file.
ZThe two reference files can then be differentially compared to
Zdetermine exactly where execution of the two processes diverges.
Z
Z.P
ZA related usage is regression testing where the execution of a current
Zversion is compared against executions of previous versions.
ZThis is most useful when there are only minor changes.
Z
Z.P
ZIt is not difficult to modify an existing compiler to implement
Zsome of the functionality of the
Z.I dbug
Zpackage automatically, without source code changes to the
Zprogram being debugged.
ZIn fact, such changes were implemented in a version of the
ZPortable C Compiler by the author in less than a day.
ZHowever, it is strongly encouraged that all newly
Zdeveloped code continue to use the debugger macros
Zfor the portability reasons noted earlier.
ZThe modified compiler should be used only for testing existing
Zprograms.
Z
Z.SK
Z.B
ZCAVEATS
Z.R
Z
Z.P
ZThe
Z.I dbug
Zpackage works best with programs which have "line\ oriented"
Zoutput, such as text processors, general purpose utilities, etc.
ZIt can be interfaced with screen oriented programs such as
Zvisual editors by redefining the appropriate macros to call
Zspecial functions for displaying the debugger results.
ZOf course, this caveat is not applicable if the debugger output
Zis simply dumped into a file for post-execution examination.
Z
Z.P
ZPrograms which use memory allocation functions other than
Z.B malloc
Zwill usually have problems using the standard
Z.I dbug
Zpackage.
ZThe most common problem is multiply allocated memory.
Z.SP 2
Z.CS
STUNKYFLUFF
set `sum user.r`
if test 9250 != $1
then
echo user.r: Checksum error. Is: $1, should be: 9250.
fi
#
#
echo Extracting vargs.h:
sed 's/^Z//' >vargs.h <<\STUNKYFLUFF
Z/******************************************************************************
Z * *
Z * N O T I C E *
Z * *
Z * Copyright Abandoned, 1987, Fred Fish *
Z * *
Z * *
Z * This previously copyrighted work has been placed into the public *
Z * domain by the author and may be freely used for any purpose, *
Z * private or commercial. *
Z * *
Z * Because of the number of inquiries I was receiving about the use *
Z * of this product in commercially developed works I have decided to *
Z * simply make it public domain to further its unrestricted use. I *
Z * specifically would be most happy to see this material become a *
Z * part of the standard Unix distributions by AT&T and the Berkeley *
Z * Computer Science Research Group, and a standard part of the GNU *
Z * system from the Free Software Foundation. *
Z * *
Z * I would appreciate it, as a courtesy, if this notice is left in *
Z * all copies and derivative works. Thank you. *
Z * *
Z * The author makes no warranty of any kind with respect to this *
Z * product and explicitly disclaims any implied warranties of mer- *
Z * chantability or fitness for any particular purpose. *
Z * *
Z ******************************************************************************
Z */
Z
Z
Z/*
Z * FILE
Z *
Z * vargs.h include file for environments without varargs.h
Z *
Z * SCCS
Z *
Z * @(#)vargs.h 1.2 5/8/88
Z *
Z * SYNOPSIS
Z *
Z * #include "vargs.h"
Z *
Z * DESCRIPTION
Z *
Z * This file implements a varargs macro set for use in those
Z * environments where there is no system supplied varargs. This
Z * generally works because systems which don't supply a varargs
Z * package are precisely those which don't strictly need a varargs
Z * package. Using this one then allows us to minimize source
Z * code changes. So in some sense, this is a "portable" varargs
Z * since it is only used for convenience, when it is not strictly
Z * needed.
Z *
Z */
Z
Z/*
Z * These macros allow us to rebuild an argument list on the stack
Z * given only a va_list. We can use these to fake a function like
Z * vfprintf, which gets a fixed number of arguments, the last of
Z * which is a va_list, by rebuilding a stack and calling the variable
Z * argument form fprintf. Of course this only works when vfprintf
Z * is not available in the host environment, and thus is not available
Z * for fprintf to call (which would give us an infinite loop).
Z *
Z * Note that ARGS_TYPE is a long, which lets us get several bytes
Z * at a time while also preventing lots of "possible pointer alignment
Z * problem" messages from lint. The messages are valid, because this
Z * IS nonportable, but then we should only be using it in very
Z * nonrestrictive environments, and using the real varargs where it
Z * really counts.
Z *
Z */
Z
Z#define ARG0 a0
Z#define ARG1 a1
Z#define ARG2 a2
Z#define ARG3 a3
Z#define ARG4 a4
Z#define ARG5 a5
Z#define ARG6 a6
Z#define ARG7 a7
Z#define ARG8 a8
Z#define ARG9 a9
Z
Z#define ARGS_TYPE long
Z#define ARGS_LIST ARG0,ARG1,ARG2,ARG3,ARG4,ARG5,ARG6,ARG7,ARG8,ARG9
Z#define ARGS_DCL auto ARGS_TYPE ARGS_LIST
Z
Z/*
Z * A pointer of type "va_list" points to a section of memory
Z * containing an array of variable sized arguments of unknown
Z * number. This pointer is initialized by the va_start
Z * macro to point to the first byte of the first argument.
Z * We can then use it to walk through the argument list by
Z * incrementing it by the size of the argument being referenced.
Z */
Z
Ztypedef char *va_list;
Z
Z/*
Z * The first variable argument overlays va_alist, which is
Z * nothing more than a "handle" which allows us to get the
Z * address of the first argument on the stack. Note that
Z * by definition, the va_dcl macro includes the terminating
Z * semicolon, which makes use of va_dcl in the source code
Z * appear to be missing a semicolon.
Z */
Z
Z#define va_dcl ARGS_TYPE va_alist;
Z
Z/*
Z * The va_start macro takes a variable of type "va_list" and
Z * initializes it. In our case, it initializes a local variable
Z * of type "pointer to char" to point to the first argument on
Z * the stack.
Z */
Z
Z#define va_start(list) list = (char *) &va_alist
Z
Z/*
Z * The va_end macro is a null operation for our use.
Z */
Z
Z#define va_end(list)
Z
Z/*
Z * The va_arg macro is the tricky one. This one takes
Z * a va_list as the first argument, and a type as the second
Z * argument, and returns a value of the appropriate type
Z * while advancing the va_list to the following argument.
Z * For our case, we first increment the va_list arg by the
Z * size of the type being recovered, cast the result to
Z * a pointer of the appropriate type, and then dereference
Z * that pointer as an array to get the previous arg (which
Z * is the one we wanted.
Z */
Z
Z#define va_arg(list,type) ((type *) (list += sizeof (type)))[-1]
Z
STUNKYFLUFF
set `sum vargs.h`
if test 1668 != $1
then
echo vargs.h: Checksum error. Is: $1, should be: 1668.
fi
echo ALL DONE BUNKY!
exit 0