C++11 class member initialization for strings

[Hendrik_S_1]

Hello,

I am having an issue, I really can't find an answer to. With the following code, I get a segmentation fault. But only for -O2 / -O3. -O0 and -O1 are fine.

The fault does occur with the C++11 initialization of the string member additionalMessage = ""; If this is not pre-set, it works just fine.

When I replace the member with char*, the code works as expected.

Since the same error occurs with GCC, I guess it is working as intended - but as stated before, I don't come up with the explenation... I could just set  additionalMessage to "" in the constructor, but I just want to know what is happening.

For any clues, I am thankful!

Greetings from Germany,

Hendrik

---------

#include <cstdlib>
#include <iostream>
#include <string>
#include <exception>

using namespace std;


class genericException : public std::exception{
public:  
  
  genericException(){
  }
  
  virtual char const* what(int lang) const throw () = 0;

  
protected:  
  int additionalId = 0;
  std::string additionalMessage = ""; // does not work
} ;

class ecTest01 : public genericException{
public:
  const char* message[2] = {"Message EN 111", "Message DE 111"};
   
  ecTest01() : genericException(){ 
  }
  
  char const* what() const throw(){     
      return message[0];   
  }   

  char const* what(int lang) const throw(){  
      return message[lang]; 
  } 
};

int main(int argc, char** argv){
  
  try{
    throw ecTest01();
  }catch(genericException& e){
    
    std::cout << e.what(0) << std::endl;
  }

  return 0;
}

[Shenghong_G_Intel]

I cannot reproduce this issue with gcc and icc. which GCC version you are using? (as you mentioned it also crash with gcc). I guess it is something wrong with your gcc? I've tried with both gcc 4.9.0 and gcc 4.8.2.

$ g++ temp.cpp -O2 -std=c++11
$ ./a.out
Message EN 111
$ g++ temp.cpp -O1 -std=c++11
$ ./a.out
Message EN 111
$ g++ temp.cpp -O3 -std=c++11
$ ./a.out
Message EN 111
$ g++ -v
Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/opt/gcc/gcc-4.9.0/libexec/gcc/x86_64-unknown-linux-gnu/4.9.0/lto-wrapper
Target: x86_64-unknown-linux-gnu
Configured with: ../gcc-4.9.0/configure --prefix=/opt/gcc/gcc-4.9.0 --disable-nls --enable-languages=c,c++
Thread model: posix
gcc version 4.9.0 (GCC)
$

Thanks,

Shenghong

[Hendrik_S_1]

Hello Shenghong,

Thank you for helping me out so quick, too bad there is no conclusive answer.

I am using G++ 4.8.3 (Red Hat 4.8.3-9). But this was just a cross test. My main problem was it not working on the icpc.

But if it works for you, I am really out of clues again... since the error occurs only for strings it might be the stringfwd.h which is broken?! But again, my C++ lib folder 4.8.3 in /usr/include/c++ just is a link to 4.8.2 which is the version it worked for you.

Regards,

Hendrik