[Swig-user] Fw: PHP callback with arguments via SWIG generates uninitialised values in valgrind
john paul
The previous didn't come out right.
I'm trying to understand why valgrind complains about 'Conditional jump or move depends on uninitialised value(s)' in the code below. I took the callback example in swig 2.0.4 and added an argument to the callback.
Can anyone help me understand why this is happening?
In example.h
/* File : example.h */
#include <iostream>
class Callback {
public:
virtual ~Callback() { std::cout << "Callback::~Callback()" << std:: endl; }
virtual void run(const std::string &s) { std::cout << s << std::endl; }
};
class Caller {
private:
Callback *_callback;
public:
Caller(): _callback(0) {}
~Caller() { delCallback(); }
void delCallback() { delete _callback; _callback = 0; }
void setCallback(Callback *cb) { delCallback(); _callback = cb; }
void call(const std::string &s) { if (_callback) _callback->run(s); }
};
In example.i
/* File : example.i */
%module(directors="1") example
%{
#include "example.h"
%}
%include "std_string.i"
/* turn on director wrapping Callback */
%feature("director") Callback;
%include "example.h"
In runme.php
# This file illustrates the cross language polymorphism using directors.
require("example.php");
# Class, which overwrites Callback::run().
class PhpCallback extends Callback {
function run($msg) {
//print "PhpCallback.run()\n";
print "PhpCallback ".$msg.PHP_EOL;
}
};
# Create an Caller instance
$caller = new Caller();
print "\n";
print "Adding and calling a PHP callback\n";
print "------------------------------------\n";
# Add a PHP callback.
$callback = new PhpCallback();
$callback->thisown = 0;
$caller->setCallback($callback);
$caller->call("hello");
$caller->delCallback();
# All done.
print "php exit\n";
Output
$php runme.php
Adding and calling a PHP callback
------------------------------------
PhpCallback hello
Callback::~Callback()
php exit
Valgrind output
$valgrind --leak-check=full --track-origins=yes php runme.php
==6660== Memcheck, a memory error detector
==6660== Copyright (C) 2002-2011, and GNU GPL'd, by Julian Seward et al.
==6660== Using Valgrind-3.7.0 and LibVEX; rerun with -h for copyright info
==6660== Command: php runme.php
==6660==
Adding and calling a PHP callback
------------------------------------
PhpCallback hello
==6660== Conditional jump or move depends on uninitialised value(s)
==6660== at 0x5F93AF: _zval_ptr_dtor (in /usr/bin/php)
==6660== by 0x631D4D: ??? (in /usr/bin/php)
==6660== by 0x62D59A: execute (in /usr/bin/php)
==6660== by 0x5FB09B: zend_call_function (in /usr/bin/php)
==6660== by 0x5FB40F: call_user_function_ex (in /usr/bin/php)
==6660== by 0x5FB461: call_user_function (in /usr/bin/php)
==6660== by 0xA7D0D25: SwigDirector_Callback::run(std::string const&) (example_wrap.cxx:1353)
==6660== by 0xA7D20D7: Caller::call(std::string const&) (in /home/xvf/downloads/swig-2.0.4/Examples/php/callback/example.so)
==6660== by 0xA7D17E4: _wrap_Caller_call (example_wrap.cxx:1563)
==6660== by 0x68CE4C: ??? (in /usr/bin/php)
==6660== by 0x62D59A: execute (in /usr/bin/php)
==6660== by 0x6090A8: zend_execute_scripts (in /usr/bin/php)
==6660== Uninitialised value was created by a stack allocation
==6660== at 0xA7D0BF2: SwigDirector_Callback::run(std::string const&) (example_wrap.cxx:1338)
==6660==
==6660== Conditional jump or move depends on uninitialised value(s)
==6660== at 0x5F93F5: _zval_ptr_dtor (in /usr/bin/php)
==6660== by 0x631D4D: ??? (in /usr/bin/php)
==6660== by 0x62D59A: execute (in /usr/bin/php)
==6660== by 0x5FB09B: zend_call_function (in /usr/bin/php)
==6660== by 0x5FB40F: call_user_function_ex (in /usr/bin/php)
==6660== by 0x5FB461: call_user_function (in /usr/bin/php)
==6660== by 0xA7D0D25: SwigDirector_Callback::run(std::string const&) (example_wrap.cxx:1353)
==6660== by 0xA7D20D7: Caller::call(std::string const&) (in /home/xvf/downloads/swig-2.0.4/Examples/php/callback/example.so)
==6660== by 0xA7D17E4: _wrap_Caller_call (example_wrap.cxx:1563)
==6660== by 0x68CE4C: ??? (in /usr/bin/php)
==6660== by 0x62D59A: execute (in /usr/bin/php)
==6660== by 0x6090A8: zend_execute_scripts (in /usr/bin/php)
==6660== Uninitialised value was created by a stack allocation
==6660== at 0xA7D0BF2: SwigDirector_Callback::run(std::string const&) (example_wrap.cxx:1338)
==6660==
==6660== Conditional jump or move depends on uninitialised value(s)
==6660== at 0x5F93AF: _zval_ptr_dtor (in /usr/bin/php)
==6660== by 0x5FAF2D: zend_call_function (in /usr/bin/php)
==6660== by 0x5FB40F: call_user_function_ex (in /usr/bin/php)
==6660== by 0x5FB461: call_user_function (in /usr/bin/php)
==6660== by 0xA7D0D25: SwigDirector_Callback::run(std::string const&) (example_wrap.cxx:1353)
==6660== by 0xA7D20D7: Caller::call(std::string const&) (in /home/xvf/downloads/swig-2.0.4/Examples/php/callback/example.so)
==6660== by 0xA7D17E4: _wrap_Caller_call (example_wrap.cxx:1563)
==6660== by 0x68CE4C: ??? (in /usr/bin/php)
==6660== by 0x62D59A: execute (in /usr/bin/php)
==6660== by 0x6090A8: zend_execute_scripts (in /usr/bin/php)
==6660== by 0x5B5F52: php_execute_script (in /usr/bin/php)
==6660== by 0x42644D: ??? (in /usr/bin/php)
==6660== Uninitialised value was created by a stack allocation
==6660== at 0xA7D0BF2: SwigDirector_Callback::run(std::string const&) (example_wrap.cxx:1338)
==6660==
==6660== Conditional jump or move depends on uninitialised value(s)
==6660== at 0x5F93F5: _zval_ptr_dtor (in /usr/bin/php)
==6660== by 0x5FAF2D: zend_call_function (in /usr/bin/php)
==6660== by 0x5FB40F: call_user_function_ex (in /usr/bin/php)
==6660== by 0x5FB461: call_user_function (in /usr/bin/php)
==6660== by 0xA7D0D25: SwigDirector_Callback::run(std::string const&) (example_wrap.cxx:1353)
==6660== by 0xA7D20D7: Caller::call(std::string const&) (in /home/xvf/downloads/swig-2.0.4/Examples/php/callback/example.so)
==6660== by 0xA7D17E4: _wrap_Caller_call (example_wrap.cxx:1563)
==6660== by 0x68CE4C: ??? (in /usr/bin/php)
==6660== by 0x62D59A: execute (in /usr/bin/php)
==6660== by 0x6090A8: zend_execute_scripts (in /usr/bin/php)
==6660== by 0x5B5F52: php_execute_script (in /usr/bin/php)
==6660== by 0x42644D: ??? (in /usr/bin/php)
==6660== Uninitialised value was created by a stack allocation
==6660== at 0xA7D0BF2: SwigDirector_Callback::run(std::string const&) (example_wrap.cxx:1338)
==6660==
Callback::~Callback()
php exit
==6660==
==6660== HEAP SUMMARY:
==6660== in use at exit: 15,624 bytes in 27 blocks
==6660== total heap usage: 21,103 allocs, 21,076 frees, 3,672,898 bytes allocated
==6660==
==6660== 88 (32 direct, 56 indirect) bytes in 1 blocks are definitely lost in loss record 5 of 12
==6660== at 0x4C2993D: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==6660== by 0x783B2C3: ???
==6660== by 0x78A804E: ???
==6660== by 0x75BDA99: ???
==6660== by 0x75BF988: ???
==6660== by 0x75C51B4: ???
==6660== by 0x6F17E72: ???
==6660== by 0x6F1F868: ???
==6660== by 0x6CE8127: ???
==6660== by 0x6096AE: zend_startup_module_ex (in /usr/bin/php)
==6660== by 0x615303: zend_hash_apply (in /usr/bin/php)
==6660== by 0x60CF29: zend_startup_modules (in /usr/bin/php)
==6660==
==6660== LEAK SUMMARY:
==6660== definitely lost: 32 bytes in 1 blocks
==6660== indirectly lost: 56 bytes in 2 blocks
==6660== possibly lost: 0 bytes in 0 blocks
==6660== still reachable: 15,536 bytes in 24 blocks
==6660== suppressed: 0 bytes in 0 blocks
==6660== Reachable blocks (those to which a pointer was found) are not shown.
==6660== To see them, rerun with: --leak-check=full --show-reachable=yes
==6660==
==6660== For counts of detected and suppressed errors, rerun with: -v
==6660== ERROR SUMMARY: 5 errors from 5 contexts (suppressed: 2 from 2)
------------------------------------------------------------------------------
This SF email is sponsosred by:
Try Windows Azure free for 90 days Click Here
http://p.sf.net/sfu/sfd2d-msazure
_______________________________________________
Swig-user mailing list
Swig...@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/swig-user