[erlang-questions] Multiple dialyzer PLTs?

[Kostis Sagonas]

Michael Radford wrote:
> I'm wondering how difficult (or even possible) it would be for dialyzer
> to support either reading multiple PLT files at startup, or a way to
> merge multiple PLT files that were produced separately.

Reading multiple PLT files at startup and merging the information in 
them is possible, but the end result is not as good as you would expect 
it to be whenever there are dependencies between functions in the 
different PLTs.  To do a good job one needs to essentially re-analyze 
the code of these functions/modules.

> We make debian packages containing compiled .beam files, and it would be
> great if these could ship with corresponding PLT files for people
> compiling other packages that depend on them.
> 
> I'd be grateful for any other suggestions on how to achieve this too.
> The next best thing seems to be using --add_to_plt and --output_plt to
> build incrementally, but we'd prefer a more packaging-friendly approach
> that doesn't make everyone wait for the same analysis over and over.

Currently, the --add_to_plt option is the only available alternative to 
what you want to do.  In case there are no mutual dependencies between 
the stuff that is already in the PLT and the new application, the 
analysis takes as much time as it takes to analyze the new application.

Kostis