problem with exception handling

problem with exception handling

[Heinrich Roder]

[-- Attachment #1: Type: text/plain, Size: 3180 bytes --]

Why do I get a dumped core in this program. I use
the newest snapshot installed, ( test.C is attached)

gdb gives the following
Breakpoint 1 at 0x4002aba4
-- main starts --
-- f1 starts -- 
L TraceLifetime constructed for a.
-- f2 starts -- 
LL TraceLifetime constructed for c.
LD TraceLifetime destroyed for c.

Breakpoint 1, 0x4002aba4 in abort ()
(gdb) where
#0  0x4002aba4 in abort ()
#1  0x8050029 in copy_reg (reg=16, udata=0xbffff894, target_udata=0xbffff824)
#2  0x80502b1 in __throw ()
#3  0x804a304 in f1 () at /home/hro/C++/test.C:58
#4  0x804a3e9 in main () at /home/hro/C++/test.C:66
#5  0x804a02b in _start ()
--------------------------



1067> g++ -v -o ff ~/C++/test.C          
Reading specs from /usr/local/lib/gcc-lib/i586-pc-linux-gnulibc1/egcs-2.90.13/specs
gcc version egcs-2.90.13 971016 (gcc2-970802 experimental)
 /usr/local/lib/gcc-lib/i586-pc-linux-gnulibc1/egcs-2.90.13/cpp -lang-c++ -v -undef -D__GNUC__=2 -D__GNUG__=2 -D__cplusplus -D__GNUC_MINOR__=90 -D__ELF__ -Dunix -Dlinux -D__ELF__ -D__unix__ -D__linux__ -D__unix -D__linux -Asystem(posix) -D__EXCEPTIONS -Di386 -Di586 -Asystem(unix) -Acpu(i386) -Amachine(i386) -D__i386__ -D__i586__ -Asystem(unix) -Acpu(i386) -Amachine(i386) /home/hro/C++/test.C /tmp/cca21366.ii
GNU CPP version egcs-2.90.13 971016 (gcc2-970802 experimental) (i386 Linux/ELF)
#include "..." search starts here:
#include <...> search starts here:
 /usr/local/include/g++
 /usr/local/include
 /usr/local/i586-pc-linux-gnulibc1/include
 /usr/local/lib/gcc-lib/i586-pc-linux-gnulibc1/egcs-2.90.13/include
 /usr/include
End of search list.
/usr/local/lib/gcc-lib/i586-pc-linux-gnulibc1/egcs-2.90.13/cc1plus /tmp/cca21366.ii -quiet -dumpbase test.cc -version -o /tmp/cca21366.s
GNU C++ version egcs-2.90.13 971016 (gcc2-970802 experimental) (i586-pc-linux-gnulibc1) compiled by GNU C version 2.7.2.3.f.1.
/usr/local/include/g++/iostream.h: In method `int ostream::opfx()':
In file included from /home/hro/C++/test.C:18:
/usr/local/include/g++/iostream.h:53: warning: implicit declaration of function `int _IO_flockfile(...)'
/usr/local/include/g++/iostream.h: In method `void ostream::osfx()':
/usr/local/include/g++/iostream.h:54: warning: implicit declaration of function `int _IO_funlockfile(...)'
 as -V -Qy -o /tmp/cca213661.o /tmp/cca21366.s
GNU assembler version 2.7 (i586-unknown-linux), using BFD version 2.7.0.2
 /usr/local/lib/gcc-lib/i586-pc-linux-gnulibc1/egcs-2.90.13/ld -m elf_i386 -dynamic-linker /lib/ld-linux.so.1 -o ff /usr/lib/crt1.o /usr/lib/crti.o /usr/local/lib/gcc-lib/i586-pc-linux-gnulibc1/egcs-2.90.13/crtbegin.o -L/usr/local/lib/gcc-lib/i586-pc-linux-gnulibc1/egcs-2.90.13 -L/usr/local/i586-pc-linux-gnulibc1/lib -L/usr/local/lib /tmp/cca213661.o -lstdc++ -lm -lgcc -lc -lgcc /usr/local/lib/gcc-lib/i586-pc-linux-gnulibc1/egcs-2.90.13/crtend.o /usr/lib/crtn.o
|11:51:08 :hro at barney> , ~/oldhome/scratch/egcs-971016/gcc :
 1068> ff
-- main starts --
-- f1 starts -- 
L TraceLifetime constructed for a.
-- f2 starts -- 
LL TraceLifetime constructed for c.
LD TraceLifetime destroyed for c.
LD TraceLifetime destroyed for c.
IOT trap/Abort (core dumped)

thanks for any help.
    HEinrich


-- 
test.C


[-- Attachment #2: test.C --]
[-- Type: text/x-c++, Size: 2145 bytes --]


class TraceLifetime {
public:

    TraceLifetime(const char* variable_name);              // Create and print message.
    ~TraceLifetime();                                      // Destroy and print message.
private:
    enum { max_objects_to_trace = 100 };                   // Maximum number of objects to trace
    static char existing_objects[1+max_objects_to_trace];  // L = live; D = destroyed.
    static int total_created;
    int instance_number;                                   // Creation sequence number.
    char var_name[21];                                     // Name of variable (first 20 chars + null)
    // This should be String, but I get an internal compiler error message when using String

};

#include <string.h>
#include <iostream.h>


int  TraceLifetime::total_created = 0;
char TraceLifetime::existing_objects[1+TraceLifetime::max_objects_to_trace] = "";


TraceLifetime::TraceLifetime(const char* variable_name) : 
    instance_number(total_created++) {
    // Copy first 20 characters of variable name
    strncpy(var_name, variable_name, 20);
    var_name[20] = '\0';

    if (total_created <= max_objects_to_trace) {

        existing_objects[total_created-1] = 'L';
        existing_objects[total_created]   = '\0';

        cout << existing_objects << " TraceLifetime constructed for " << var_name << "." << endl;
    }
}
 
TraceLifetime::~TraceLifetime() {
    if (instance_number < max_objects_to_trace) {
        existing_objects[instance_number] = 'D';
        cout << existing_objects << " TraceLifetime destroyed for " << var_name << "." << endl;
    }
}

//main routines start here
void f2() {
    cout << "-- f2 starts -- " << endl;
    TraceLifetime c("c");
    throw "exception";
    cout << "-- f2 ends -- " << endl;
}

void f1() {
    cout << "-- f1 starts -- " << endl;
    TraceLifetime a("a");
    f2();
    TraceLifetime b("b");
    cout << "-- f1 ends -- " << endl;
}

int main() {
    cout << "-- main starts --" << endl;
    try { 
        f1();
    }
    catch(const char* dd) {
      cout << "Exception caught." <<dd<< endl;
    }
    cout << "-- main ends --" << endl;
    return 0;
}

Re: problem with exception handling

[H.J. Lu]

> 
> 
> --C0X6iWwYi9OgoVx8GtiA8gVni+RCEOFHDcBlzx9W
> Content-Type: text/plain; charset=us-ascii
> Content-Transfer-Encoding: 7bit
> 
> Why do I get a dumped core in this program. I use
> the newest snapshot installed, ( test.C is attached)
> 
> gdb gives the following
> Breakpoint 1 at 0x4002aba4
> -- main starts --
> -- f1 starts -- 
> L TraceLifetime constructed for a.
> -- f2 starts -- 
> LL TraceLifetime constructed for c.
> LD TraceLifetime destroyed for c.
> 
> Breakpoint 1, 0x4002aba4 in abort ()

I have no problems on linux/x86 libc 5.4.39.

H.J.

Re: problem with exception handling

[Jeffrey A Law]

  In message <199710171756.LAA21622@barney.lanl.gov>you write:
  > 
  > --C0X6iWwYi9OgoVx8GtiA8gVni+RCEOFHDcBlzx9W
  > Content-Type: text/plain; charset=us-ascii
  > Content-Transfer-Encoding: 7bit
  > 
  > Why do I get a dumped core in this program. I use
  > the newest snapshot installed, ( test.C is attached)
  > 
  > gdb gives the following
  > Breakpoint 1 at 0x4002aba4
  > -- main starts --
  > -- f1 starts -- 
  > L TraceLifetime constructed for a.
  > -- f2 starts -- 
  > LL TraceLifetime constructed for c.
  > LD TraceLifetime destroyed for c.
  > 
  > Breakpoint 1, 0x4002aba4 in abort ()
  > (gdb) where
  > #0  0x4002aba4 in abort ()
  > #1  0x8050029 in copy_reg (reg=16, udata=0xbffff894, target_udata=0xbffff82
  > 4)
  > #2  0x80502b1 in __throw ()
  > #3  0x804a304 in f1 () at /home/hro/C++/test.C:58
  > #4  0x804a3e9 in main () at /home/hro/C++/test.C:66
  > #5  0x804a02b in _start ()
  > --------------------------
Your testcase works for me using the current sources; you should
try it after I make the next snapshot.

jeff