CODEWITHSUNDEEP
phpc++corbaomniorb
thanassis
thanassis

Reputation: 691

PHP extension CORBA client with omniORB libraries gives runtime error with "undefined symbol "

We are trying to create a PHP extension in C++ that will operate as a CORBA client.

The server side is written in Java. Our runtime environment is CentOS 6.6.

We have used omniORB to compile the IDL and create the C++ skeleton code for the client. Our first step was to create a client program that works correctly. We then included the functionality in a PHP extension that compiles and links without any errors.

When however our extension library is installed and tested in PHP we get the following error:

PHP Warning: PHP Startup: Unable to load dynamic library '/usr/lib64/php/modules/php_midas.so' - /usr/lib64/php/modules/php_midas.so: undefined symbol: _ZTv0ortableServer11ServantBase9_downcastEv in Unknown on line 0.

Upvotes: 3

Views: 406

Answers (2)

thanassis
thanassis

Reputation: 691

The solution to the problem was to change the config.m4 file used for setting up the php extension, so that it included references to the omniORB libraries using the PHP_ADD_LIBRARY_WITH_PATH macro instead of the PHP_ADD_LIBRARY one, although the libraries were in the default /usr/lib64 folder.

I am including the entire file as a working reference.

dnl PHP extension definition written in C++ that uses the omniORB libraries
PHP_ARG_ENABLE(php_midas, whether to enable midas extension, [  --enable-php-midas   Enable PHP Midas extension])

if test "$PHP_MIDAS" != "no"; then    

    dnl -- Add support for standard C++ runtime    
    PHP_ADD_LIBRARY_WITH_PATH( stdc++, /usr/lib64/, PHP_MIDAS_SHARED_LIBADD)

    dnl -- Incldue the omniORB libraries
    PHP_ADD_LIBRARY_WITH_PATH(omniCodeSets4, /usr/lib64/, PHP_MIDAS_SHARED_LIBADD)
    PHP_ADD_LIBRARY_WITH_PATH(omniConnectionMgmt4, /usr/lib64/, PHP_MIDAS_SHARED_LIBADD)
    PHP_ADD_LIBRARY_WITH_PATH(omniDynamic4, /usr/lib64/, PHP_MIDAS_SHARED_LIBADD)
    PHP_ADD_LIBRARY_WITH_PATH(omniORB4, /usr/lib64/, PHP_MIDAS_SHARED_LIBADD)    
    PHP_ADD_LIBRARY_WITH_PATH(omnithread, /usr/lib64/, PHP_MIDAS_SHARED_LIBADD)

    dnl -- Our extension consists of two cpp files            
    PHP_NEW_EXTENSION(php_midas, php_midas.cpp coordinatesConverterSK.cpp, $ext_shared)

    PHP_SUBST(PHP_MIDAS_SHARED_LIBADD)

    dnl -- Declare C++ extension
    PHP_REQUIRE_CXX()
fi

Upvotes: 1

A. Abramov
A. Abramov

Reputation: 1865

Altered from Source:

There are many different reasons which could cause such a problem with the DLLs. First - Ensure all the files are in place - does the midas module exist there? is there a proper referance to it in the enviroment?

Make sure the extension is set -Make sure you have the SO module, and then that your configuration file has the SO type as the extension type, or in other words, this line exists:

extension=module.so

If this didn't help, consider dynamically checking the linker - is the error in the loading, or some of the headers didnt fit?

Let me know what happened.

EDIT: It seems like the error is in the loading beacuse of undefined syntax. Well then, here is a similar case I will base my answer on.

Your error means, that ZTv0ortableServer11ServantBase9_downcastEv symbol cannot be found in shared libraries used by the module. It is probably provided by a library which is not a defualt - not php-gd, probably omniORB.

readelf -s <path to SO file>

and

nm -D <path to SO file>

will list symbols and I'm very sure, that you won't find it there.

There's probably an unupdated library from the omniORB type interfering with the referance - for example Remi could be one. If you have it in your code, or any other one which might do this, you could reset them;

For example, if you think the remi files are interfering, you can reset them by Removing all remi packages (rpm -qa|grep remi), delete remi-release package and install last available php/gg/etc packages from EPEL repository (you may need to downgrade them with rpm -Uvh package.rpm --oldversion). Then upgrade all packages.

Some more links with similar questions can be found here, here, here, and even here.

Let me know if this helped you.

Upvotes: 0

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