The <cxxVariableDeclarationFile> element is defined within <cxxVariableAPIItemLocation>. <cxxVariableDeclarationFile> specifies the file in which the API declaration is present.
The element <cxxVariableDeclarationFile> is empty but for the required attributes name and value. Name is always "filePath" and value is the path to the declaration file.
<cxxVariableAPIItemLocation>
<cxxVariableDeclarationFile name="filePath" value="C:/src/include/e32base.h"/>
<cxxVariableDeclarationFileLine name="lineNumber" value="1664"/>
</cxxVariableAPIItemLocation>