3
votes

I'm porting for AIX a pretty stable code wich already runs in Windows, Linux (both 32 and 64 bits) and Solaris SPARC and x86. The code throws exceptions across shared libraries:

Environment: IBM AIX 5.3 64 Bits
Compiler: GCC 4.6.1

Note: The issue occurs either with code compiled in 32 or 64 bits

The architecture is a little bit complicated, but basically we have: CoreModules.a: Static library which contais all core functions, objects and structures used by the shared libraries. The exception class is defined here and exceptions are thrown by classes defined here. Generated with $(AR).

libConfig.so: Shared library which contains config info. Linked against CoreModules.a. Exceptions are thrown by classes defined here.

libHostServices.so: Shared library which contains the business rules. Linked against CoreModules.a and libConfig.so. Exceptions are thrown by classes defined here.

Here goes my compiling and linking options:

export CXX=g++
export MODE=debug
if [ "$OBJECT_MODE" -eq 64 ]
then 
    export CXXFLAGS="-g -v -W -Wall -fPIC -O2 -mminimal-toc -fpermissive -fexceptions -Wmissing-field-initializers -Wwrite-strings -Wformat -maix64"
else 
    export CXXFLAGS="-g -v -W -Wall -fPIC -O2 -mminimal-toc -fpermissive -fexceptions -Wmissing-field-initializers -Wwrite-strings -Wformat"
export LDFLAGS=-Wl,-G -Wl,-bexpall
export AR=ar -q -X32_64

The examples below were generated with OBJECT_MODE=64

My GCC generation options are

Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/opt/freeware/libexec/gcc/powerpc-ibm-aix5.3.0.0/4.6.1/lto-wrapper
Target: powerpc-ibm-aix5.3.0.0
Configured with: ../gcc-4.6.1/configure --with-as=/usr/bin/as --with-ld=/usr/bin/ld --enable-languages=c,c++,fortran --prefix=/opt/freeware --mandir=/opt/freeware/man --infodir=/opt/freeware/info --enable-threads --enable-version-specific-runtime-libs --disable-nls --enable-decimal-float=dpd --host=powerpc-ibm-aix5.3.0.0
Thread model: aix
gcc version 4.6.1 (GCC)
COLLECT_GCC_OPTIONS='-g' '-v' '-Wextra' '-Wall' '-fPIC' '-O2' '-mminimal-toc' '-fpermissive' '-fexceptions' '-Wmissing-field-initializers' '-Wwrite-strings' '-Wformat' '-maix64' '-c' '-I' '.' '-I' '../../../src/HostServices' '-I' '../../../src/InterfaceCTest' '-D' '_LOG' '-D' '_LOGSTDOUT' '-D' '_DEBUG' '-shared-libgcc'
 /opt/freeware/libexec/gcc/powerpc-ibm-aix5.3.0.0/4.6.1/cc1plus -quiet -v -I . -I ../../../src/HostServices -I ../../../src/InterfaceCTest -imultilib ppc64 -D_ALL_SOURCE -D__64BIT__ -D _LOG -D _LOGSTDOUT -D _DEBUG ../../../src/InterfaceCTest/InterfaceCTest.c -quiet -dumpbase InterfaceCTest.c -mminimal-toc -maix64 -auxbase InterfaceCTest -g -O2 -Wextra -Wall -Wmissing-field-initializers -Wwrite-strings -Wformat -version -fPIC -fpermissive -fexceptions -o /u01/ceibo/desen/tmp/ccQYtChL.s

All my modules are linked to shared gcc (as they have to be to throw exception across shared libraries):


libConfig.so needs:
         /opt/freeware/lib/gcc/powerpc-ibm-aix5.3.0.0/4.6.1/ppc64/libstdc++.a(libstdc++.so.6)
         /opt/freeware/lib/gcc/powerpc-ibm-aix5.3.0.0/4.6.1/ppc64/libgcc_s.a(shr.o)
         /usr/lib/libc.a(shr_64.o)
         /unix
         /usr/lib/libcrypt.a(shr_64.o)

libHostServices.so needs:
         ../../../bin/aix/debug/libConfig.so
         /opt/freeware/lib/gcc/powerpc-ibm-aix5.3.0.0/4.6.1/ppc64/libstdc++.a(libstdc++.so.6)
         /opt/freeware/lib/gcc/powerpc-ibm-aix5.3.0.0/4.6.1/ppc64/libgcc_s.a(shr.o)
         /usr/lib/libc.a(shr_64.o)
         /unix
         /usr/lib/libcrypt.a(shr_64.o)

InterfaceCTest needs:
         /usr/lib/libc.a(shr_64.o)
         ../../../bin/aix/debug/libHostServices.so
         ../../../bin/aix/debug/libConfig.so
         /opt/freeware/lib/gcc/powerpc-ibm-aix5.3.0.0/4.6.1/ppc64/libgcc_s.a(shr.o)
         /unix
         /usr/lib/libcrypt.a(shr_64.o)
         /opt/freeware/lib/gcc/powerpc-ibm-aix5.3.0.0/4.6.1/ppc64/libstdc++.a(libstdc++.so.6)

When I execute the executable InterfaceCTest, I get:


GNU gdb 6.0
Copyright 2003 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB.  Type "show warranty" for details.
This GDB was configured as "powerpc-ibm-aix5.1.0.0"...
(gdb) run
...
Program received signal SIGABRT, Aborted.
0x090000000005ca8c in raise () from /usr/lib/libc.a(shr_64.o)
(gdb) where
#0  0x090000000005ca8c in raise () from /usr/lib/libc.a(shr_64.o)
#1  0x0900000000088008 in abort () from /usr/lib/libc.a(shr_64.o)
#2  0x090000000f16a704 in __gnu_cxx::__verbose_terminate_handler() () at  _start_ :95
#3  0x090000000f173b34 in __cxxabiv1::__terminate(void (*)()) (handler=
findvar.c:706: internal-error: value_from_register: Value not stored anywhere!
A problem internal to GDB has been detected,
further debugging may prove unreliable.
Quit this debugging session? (y or n) findvar.c:706: internal-error: value_from_register: Value not stored anywhere!
IOT/Abort trap(coredump)
A problem internal to GDB has been detected,
further debugging may prove unreliable.
Create a core file of GDB? (y or n) 

I've passed the last three days googling anything I could be doing wrong but I got nothing untill now. The link AIX: Why does throwing an exception abort multithreaded code? works fine for me, so I'm sure the issue is due to exceptions being thrown across shared libraries.

Does anyone have any idea of what I might be doing wrong?

Thanks


I've done a pretty simple test and now I'm pretty sure It is something related to my environment:

Library libCore.a:

Header Core.h:

#ifdef __cplusplus
extern "C" {
#endif

void ThrowException();

#ifdef __cplusplus
} //extern "C"
#endif

Body:

#include "Core.h"

void ThrowException()
{
    try
    {
    throw new int;
    }
    catch(int * e)
    {
       printf("Exception int caught\n");
    }
    catch(...)
    {
       printf("Exception ... caught\n");
    }   
}

Executable CoreCTest:

#include "Core.h"

int main()
{

    ThrowException();

    return 1;
}

And when I execute my executable, I get:

./CoreCTest
terminate called after throwing an instance of 'int*'
IOT/Abort trap(coredump)

The ldd returns:

CoreCTest needs:
         /usr/lib/libc.a(shr_64.o)
         /usr/lib/libpthreads.a(shr_xpg5_64.o)
         ../../../bin/aix/debug/libCore.a
         /opt/freeware/lib/gcc/powerpc-ibm-aix5.3.0.0/4.6.1/pthread/ppc64/libgcc_s.a(shr.o)
         /unix
         /usr/lib/libcrypt.a(shr_64.o)
         /opt/freeware/lib/gcc/powerpc-ibm-aix5.3.0.0/4.6.1/pthread/ppc64/libstdc++.a(libstdc++.so.6)

Does anyone have ANY idea of what is going on? Any help would be really appreciated!

Thanks

1
Just wondering, isn't your libCore.a a shared library? Why the .a suffix?n. 1.8e9-where's-my-share m.
N.m., IBM AIX uses a different concept of shared libraries than the other unix systems. Shared libraries have .a extension and run time linkable binaries have .so (it's a mess hehe).Cadu
Solved!!!!!! Two tips for the ones dealing with the same issue: 1 - Use BASH as your shell - other shells will give you messy duplicated symbols (unbelievable, I know - gcc.gnu.org/bugzilla/show_bug.cgi?id=13391) 2 - Missing -shared on my LDFLAGS; 3 - LDFLAGS was allowing unresolved symbols. New LDFLAGS=-shared -Wl,-G,-bernotok -Wl,-bnoentry -Wl,-bexpallCadu

1 Answers

1
votes

I could resolve this issue by supplying the linker with the "-lsupc++" option which links this library.