How to see Qt5 QString contents while debugging on Visual Studio 2015

Question

I'm using visual studio 2015 and Qt5.

I'have already added qt5.natvis on Vislaualizers folders. I have set the "Use Native Compatibility Mode" option in Tools > Options > Debugging > General menu.

Even so, QString value does not appear correctly when debugging. Only memory direction appears on Locals/Autos/Watch windows. Any idea?

I have set Verbose option for Native diagnostic messages and this is what I get:

Natvis: Parsing natvis xml file: D:\<user_name>\Documents\Visual Studio 2015\Visualizers\qt5.natvis.
Natvis: Fatal error: 
Natvis: Parsing natvis xml file: C:\PROGRAM FILES (X86)\MICROSOFT VISUAL STUDIO 14.0\COMMON7\IDE\EXTENSIONS\MICROSOFT\PYTHON TOOLS FOR VISUAL STUDIO\2.2\PythonDkm.natvis.
Natvis: Fatal error: 
Natvis: C:\Program Files (x86)\Microsoft Visual Studio 14.0\Common7\Packages\Debugger\Visualizers\qt.natvis(128,25): Error: a pointer to a bound function may only be used to call the function
Error while evaluating 'd->data,sub' in the context of type '<executable>!QString'.
Natvis: C:\Program Files (x86)\Microsoft Visual Studio 14.0\Common7\Packages\Debugger\Visualizers\qt.natvis(127,6): Ignoring visualizer for type 'QString' labeled as 'QString' because one or more sub-expressions was invalid.

Answer 1

You need to use older natvis files. The ones you're using appear to use functionality that wasn't available in VS 2015.

The natvis file comes from the qt-labs/vstools repository. GitHub's online browser shows two revisions for src/qtvstools/qt5.natvis.xml, one from 2018, another from 2020.

The the 2018 revision also renamed the file from src/qtvisualizer/qt5.natvis.xml, with one prior revision.

Since the oldest revision is from 2016, maybe that'd work for you with VS 2015.

Answer 2

Original qt5.natvis from qt plugin for MSVS contains some strange problem. I use alternative natvis. I'm not sure if this will work correctly on MSVS 2015, if so, you can ask the author to help you