GDB watchpoint does not detect change of the value of variable

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Hi, i am newly to c++ and debugging with gdb. I tryed to debug my program where the value of global variable gets empty in some part of the code . I compile the program with -g , then run gdb command and set the variable to be watched with watch [variable_name]. Than run command , and the program stop at the line of assigning, but after continue-command, program did not stops on any line till the end..My program has many files respectively translation units. This is all I think.. Do I miss something?

What I have tried:

I saw, that the address of that variable which value I am interested in did not change from the moment of its creation, but somehow its value does.

Posted 2-Dec-22 3:55am

Деян Цонев

Updated 2-Dec-22 4:03am

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Richard MacCutchan 2-Dec-22 10:12am

Can you show the code, and explain where you set the watchpoint?

Деян Цонев 3-Dec-22 2:16am

code part ******************************
else
{
system_config.outboundHost = pSockOutboundConfigElement->Attribute(SOCKET_CONFIG_XML_OUTBOUND_HOST_ATTR); // on the line //of assignment I set the watchpoint, and the next line is the line where stops, and after c //command program don't stop any more, but the value get's changed somewhere
if ( system_config.outboundHost == nullptr )
throw MISSING_ATTRIBUTE SOCKET_CONFIG_XML_OUTBOUND_HOST_ATTR;

code part*****************************

Richard MacCutchan 3-Dec-22 3:19am

Exactly which address do you set in the watchpoint, and where does the referenced item get changed? Please use the Improve question link above, and add the details to your question.

Деян Цонев 2-Dec-22 12:53pm

I set it after running the gdb command. Where should it be set? I thought the watch command can be use this way, but even if I set it right before the assignment of the variable which I watch , again the result is only one stop on line, when the first assignment is set by me and the second where I am debbuging is not shown.

Richard MacCutchan 2-Dec-22 13:53pm

If you wish to reply to a comment then please use the Reply button above the message. As it stands I was not alerted to your comments.

Деян Цонев 2-Dec-22 14:15pm

Ok, sorry. I will use button for now on .

Richard MacCutchan 3-Dec-22 6:51am

I have just tried a simple test, and gdb stopped every time my watched variable changed.

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