Message-ID:	<3AD0B992.44D0D3C3@jps.net>
From:	Dennis Yelle <dennis51 AT jps DOT net>
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Newsgroups:	comp.os.msdos.djgpp
Subject:	gdb still doesn't work for me
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Date:	Sun, 08 Apr 2001 12:18:42 -0700
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To:	djgpp AT delorie DOT com
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Reply-To:	djgpp AT delorie DOT com

I have been using the DJGPP C++ compiler for some time now.
I like it a lot.

But I have never been able to get gdb to work properly for me.
Does anyone actually use it?

Yesterday, I noticed that there was a new version of gdb available,
so I used the zip picker to select the whole package
of files and downloaded and installed them.

The compiler works fine, but still gdb fails me.
It seems to work a little better than before, so
I started experimenting with it.

I have a program that is only one file, about 560 lines long,
plus the included standard headers.
I compiled it with this:
    redir -eo -t gxx -g -Os -Wall test.cpp -o test.exe
I got no errors and no warnings.

I ran the program, like this:
    test > z
It finished in less than 1 second.

I ran gdb like this:
  gdb test.exe
  break main
  n
  n
  n
  n
  n
  n
  n
At this point, the program produces about 64 lines of
output to the screen, but I noticed a significant pause
every 4th line.  The total of all of the pauses was
far more than 1 second.  So, it seems to me that the 
program is running significantly slower under gdb than
when run alone.
Then I typed:
  n
At this point the program produced two lines of output
to the screen, and then started "running" very slowly.

Is it a known problem that programs run very slowly when
run under gdb?

I tried to simplify the problem in several ways:

1. The program contains about 50 lines that have been
   "commented out" with
      #if 0
      // ...
      #endif
   If I completely remove most of those lines from the program,
   the problem goes away.
   Does gdb have problems with programs that are more than 
   512 lines long?

2. I removed the -Os from the compile line.
   The problem went away.
   Does gdb have problems with -Os ?

If anyone wants to try to reproduce this problem on another
machine, the source for the program is here:
  http://www2.jps.net/~vert/test.cpp
the short input file named 'in' is here:
  http://www2.jps.net/~vert/in

Thank you all for any help you can give me about this problem.

Dennis Yelle
-- 
I am a computer programmer and I am looking for a job.
There is a link to my resume here:  
http://table.jps.net/~vert/

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