Delphi compiler warnings pointing to Delphi's own units

Question

In Delphi 2007, working on a project which includes a custom component, I'm getting this set of warnings as the first four in Messages when I do a full build (but not when I do a straight compile):

[DCC Warning] Dialogs.pas(1426): W1002 Symbol 'TFileOpenDialog' is specific to a platform
[DCC Warning] Dialogs.pas(1446): W1002 Symbol 'TFileSaveDialog' is specific to a platform
[DCC Warning] ComCtrls.pas(6757): W1036 Variable 'Section' might not have been initialized
[DCC Warning] ComCtrls.pas(19268): W1023 Comparing signed and unsigned types - widened both operands

I generally try to eliminate compiler warnings where I can, but these are "stock" Delphi units. Are these warnings the indirect result of something in my code? If so, how do I figure out what/where? If not, what should I do about them?

Answer 1

I believe it is because you have the stock Delphi source in your build path. If you remove the Delphi source directories, then it should build without these warnings.

Answer 2

I spent ages getting these problems (well, your first two anyway) and in my ignorance actually uninstalled Delphi and reinstalled it to no avail. I finally found that it is caused by the lack of project settings. At least atfirst, if you migrate a projects from an earlier Delphi, your existing project settings get converted but for no apparent reason Delphi can start forgetting about this and gives you a 'blank' set of project settings. You can see this by opening Project-Options where you will find Base, Release and Debug. Check out the active one (it is bold in the project manager) and you should see that it has no directory paths as well as all hints and warnings at their defaults. Most of these defaults are fine but 'Platform Symbol' and 'Platform unit' should be disabled (at least for Win32 stuff). Regards, Brian

Answer 3

The reason they show up only when doing a Build is that the compile command only only compiles source which has changed since the previous compile. While the Build command recompiles everything in the project regardless of changes.

The warnings are most likely caused by the Delphi source folder being included in the project search path. Removing it and deleting the dcus in your project's folder will tell you if anything in the project required the Delphi source when you recompile. In my experience you should need the Delphi source if you have found a bug in Delphi's implementation and made a custom copy of a Delphi class to correct the bug. If this is the case when you try to build without the Delphi source you will usually get:

Unit '%s' is compiled with unit '%s' in '%s' but different version '%s' found (F2446)

Where %s will be some low level Delphi class.

If you don't get any error's it didn't really need the Delphi source.

This can also happen if the Delphi source is in the environment search path.

Answer 4

If you want to continue explicitly compiling the VCL source into your project you can make a copy of the units that are raising the compiler hints/warnings and "fix" the hints/warnings in that copy. Put the updated/"fixed" copies of those VCL units in another folder and make sure you add the path to that folder to your project's Search path BEFORE the path to the Delphi VCL source.

E.g. my project search path looks something like this: "C:\Dev\Source\MyFixedVCLUnits;C:\Program Files\CodeGear\RAD Studio\6.0\source"

To give an example of the simple fixes required to remove these warnings, here is one of the functions in the Dialogs.pas that now lives in my "C:\Dev\Source\MyFixedVCLUnits" folder:

{$WARNINGS OFF}
function TFileOpenDialogWrapper.CreateFileDialog: TCustomFileDialog;
begin
Result := TFileOpenDialog.Create(nil);
Result.OnExecute := OnExecuteEvent;
end;
{$WARNINGS ON}

In this case, just add the {$WARNINGS OFF} etc as required.