🚀 go-pugleaf

Witam,

Ponizej jest prosty program, ktory, przynajmniej na moich komputerach, nie
da sie porzadnie debugoac - nie mozna wejsc do funkcji 'fun' (polecenie
's'). Od razu wyswietla wynik dziala 'fun' i to od razu dwoch wywolan.

Co ciekawsze, jesli sie cokolwiek w programie zmieni, np. f=1 to nie ma tego
problemu. PRzy f=0 lub nieinicjwowanym w ogole - jest.

Czy u Was tez tak jest? Co tego moze byc przyczna? Jakies magiczene,
domyslne opcje 'optymalizacyjne'? Jak to zmienic?

Zapis dzialan:
-----------------------------------------------------------------------------------
laser@ml-linux-1:~$ cc -g -o xxx xxx.c
laser@ml-linux-1:~$ gdb xxx

warning: Can not parse XML syscalls information; XML support was disabled at compile time.
GNU gdb (GDB) 7.0.1-debian
Copyright (C) 2009 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "i486-linux-gnu".
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>...
Reading symbols from /mnt/sdb1/home/users/laser/xxx...done.
(gdb) b main
Breakpoint 1 at 0x80483ef: file xxx.c, line 37.
(gdb) r
Starting program: /mnt/sdb1/home/users/laser/xxx

Breakpoint 1, main (argc=1, argv=0xbffff6c4) at xxx.c:37
37	  fun(f, &o, &q, &r);
(gdb) p f
$1 = -1073744408
(gdb) s
aaa
aaa

Program exited normally.
(gdb) quit
--------------------------------------------------------------------------------------------------
Skrypt wykonany pią, 11 lis 2011, 15:13:31


Moj kompilator:
laser@ml-dom:~/laser/c/sms-1.0$ gcc -v
Using built-in specs.
Target: i486-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Debian 4.4.5-8'
--with-bugurl=file:///usr/share/doc/gcc-4.4/README.Bugs
--enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr
--program-suffix=-4.4 --enable-shared --enable-multiarch
--enable-linker-build-id --with-system-zlib --libexecdir=/usr/lib
--without-included-gettext --enable-threads=posix
--with-gxx-include-dir=/usr/include/c++/4.4 --libdir=/usr/lib
--enable-nls --enable-clocale=gnu --enable-libstdcxx-debug
--enable-objc-gc --enable-targets=all --with-arch-32=i586
--with-tune=generic
--enable-checking=release --build=i486-linux-gnu --host=i486-linux-gnu
--target=i486-linux-gnu
Thread model: posix
gcc version 4.4.5 (Debian 4.4.5-8)

Program 'xxx.c':
-------------------------------------------------------------
#include <stdlib.h>
#include <stdio.h>
#include <string.h>

int fun(int f, unsigned char * a, unsigned * b, unsigned * c)
{
  while(1)
  {
    puts("aaa");
    if(f <= 0)
      return 0;
  }

  return 0;
}

int main(int argc, const char * argv[])
{
  int			f/* = 0*/;
/*  int			f = 1;*/
  int			a;
  int			b;
  const char *		c;
  char			d;
  int			e;
  unsigned char		g;
  int			h;
  unsigned char		i;
  FILE *		j;
  const char *		k;
  time_t		l;
  const char *		m;
  const char *		n;
  unsigned char		o;
  unsigned		q, r;

  fun(f, &o, &q, &r);
  fun(f, &o, &q, &r);

  return 0;
}
------------------------------------------------------------


-- 
ml

http://www.archimedes.eu.org/