[Qt-interest] qt creator can't evaluate expression when debugging?

[Thiago Macieira]

On Tuesday, 13 de September de 2011 23.41.07, Li Li wrote:
> hi all,
>     I am using qt creator to debug. I have a QUrl local variable. I want to
> view it's value. But  Locals and Expressions view don't show anything. And I
> add a line:   QString ss=qurl.toString(); the locals and expressions view
> can display local variable ss. So I Insert NewWatch Item qurl.toString().
> but it says <no such values>. I also tried QString::number(1). it can't
> even evaluate this! What's wrong with it? I am using qt sdk 1.1.2 in
> ubuntu.

Calling C++ methods that allocate objects is very unstable in gdb. And you 
shouldn't try, because the destructor is never run, so you're just going to 
leak memory forever in gdb.

I'm actually surprised that I *could* call the method at all. Calling a method 
that returns a non-trivial object (in the ABI's definition of "non-trivial") 
requires the caller allocating space and passing an implicit first parameter.

-- 
Thiago Macieira - thiago (AT) macieira.info - thiago (AT) kde.org
   Software Architect - Intel Open Source Technology Center
      PGP/GPG: 0x6EF45358; fingerprint:
      E067 918B B660 DBD1 105C  966C 33F5 F005 6EF4 5358
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