Clicking on an entity in a source file and selecting the
Refactoring/Rename menu will open a dialog asking for the new name
of the entity. GPS will rename all instances of the entity in your application.
This includes the definition of the entity, its body, all calls to it, etc...
Of course, no comment is updated, and you should probably check manually that
the comment for the entity still applies.
GPS will handle primitive operations by also renaming the operations it overrides or that overrides it. This means that any dispatching call to that operation will also be renamed, and the application should still work as before. If you are renaming a parameter to a subprogram, GPS can also rename parameters with similar names in overriding or overridden subprograms.
The behavior when handling read-only files can be specified: by default, GPS will not do any refactoring in these files, and will display a dialog listing all of them; but you can also choose to make them writable just as if you had clicked on the "Read-Only" button in the status bar of the editor and then have GPS perform the renaming in them as well.