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From: "icegood1980 at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/55148] New: wrong compilation of chars: overlapped memory areas
Date: Wed, 31 Oct 2012 12:10:00 -0000	[thread overview]
Message-ID: <bug-55148-4@http.gcc.gnu.org/bugzilla/> (raw)


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55148

             Bug #: 55148
           Summary: wrong compilation of chars: overlapped memory areas
    Classification: Unclassified
           Product: gcc
           Version: 4.7.2
            Status: UNCONFIRMED
          Severity: major
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: icegood1980@gmail.com


if one uses a stringification operation then problems could be obtained on
stack:

brackets.cpp : 

#include <iostream>
#include <cstring>
#define GLOBAL_str_intermediate(s)                                            \
({                                                                            \
  char GLOBAL_str_intermediate_buf[1024];                                     \
  strcpy(GLOBAL_str_intermediate_buf, #s);                                    \
  GLOBAL_str_intermediate_buf[strlen(GLOBAL_str_intermediate_buf)-1]='\0';    \
  GLOBAL_str_intermediate_buf+1;                                              \
})

#define GLOBAL_str(s) GLOBAL_str_intermediate((s))
#define s_one_arg a,b,c

int main(int argc, const char **argv)
{
  char PairPotentialName[70], *p=GLOBAL_str(s_one_arg);
  //
  std::cerr<<p-PairPotentialName<<std::endl;
  std::cerr<<PairPotentialName+1<<std::endl;
  return 0;
}

g++ brackets.cpp 
./a.out:
1
a,b,c
so PairPotentialName and p are overlapped!


             reply	other threads:[~2012-10-31 12:10 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-10-31 12:10 icegood1980 at gmail dot com [this message]
2012-10-31 12:17 ` [Bug c++/55148] " redi at gcc dot gnu.org
2012-10-31 12:23 ` redi at gcc dot gnu.org
2012-10-31 12:40 ` icegood1980 at gmail dot com
2012-10-31 12:43 ` icegood1980 at gmail dot com

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