linking Qt Creator plugin editor / highlighter

Question

I'm working on a qt creator plugin that adds support for certain types of files by supplying customized editors, etc. Right now it registers a new IEditorFactory which produces editors that I based off of the TextEditor::BaseTextEditor and TextEditor::BaseTextEditorWidget.

Eventually I will be creating and using specialized highlighters and other things, but for now I want to utilize things from other qt creator plugins, and this is where I run into trouble.

In particular I want to use the TextEditor::Internal::Highlighter, which can load and utilize kate files. I'm already using other classes from the TextEditor plugin so I have

include($$QTCREATOR_SOURCES/src/plugins/texteditor/texteditor.pri)

added to my project file. Inside texteditor.pri everything seems good

include(texteditor_dependencies.pri)
LIBS *= -l$$qtLibraryName(TextEditor)

and, indeed, I'm able to compile my editor (which is dependent on things inside the texteditor plugin).

The only difference with the TextEditor::Internal::Highlighter -as far as I can tell- is that it's in a subfolder of the texteditor plugin. This should be fine, and the object files seem to all land in the same directory, but when I say

new TextEditor::Internal::Highlighter()

(just as is done in texteditor/plaintexteditor.cpp) I get a linker error

Undefined symbols for architecture x86_64:
  "TextEditor::Internal::Highlighter::Highlighter(QTextDocument*)", referenced from:
      MyPlugin::MyEditorWidget::MyEditorWidget(QWidget*)in myeditor.o
      MyPlugin::MyEditorWidget::MyEditorWidget(QWidget*)in myeditor.o
ld: symbol(s) not found for architecture x86_64
collect2: ld returned 1 exit status

What am I doing wrong? Are there more dependencies I have to declare? Is there a command I can use to force a folder of object files to be in my path while compiling?

Thnaks!

Answer 1

The classes and methods in the "Internal" namespace tend to not be exported, so they are not available outside the plugin that provides them. Check the class definition: Does it have "SOMETHING_EXPORT" between the class keyword and the class name? If not, then you are out of luck.

By default as few symbols as possible are exported: That leaves us a chance to actually change things around without worrying about breaking code outside the plugin. It also reduces load times a bit. If you have a use-case for the symbol to be exported: Feel free to ask on the Qt Creator mailing list or -- better yet -- provide a patch to codereview.qt-project.org which moves the class out of the Internal namespace and exports the symbol.

A better place to get questions like this answered is the Qt Creator mailing list and the #qt-creator IRC channel on freenode network.