[PATCH] D27091: Add the way to extract SVals of arguments used in a call for a given StackFrameCtx

[Anna Zaks via Phabricator via cfe-commits]

zaks.anna added a comment.

> Hmm, i'm thinking of just the opposite - refactor the CallEvent methods to use the respective new  ProgramState methods.
> 
> This way we'd avoid touching the CallEvent allocator for a simple Environment lookup, while still avoiding code duplication.

I see what you are suggesting, but I still have the concerns I've mentioned in my first comment. **The whole purpose of CallEvent is to allow an easy and lightweight way of dealing with all the different types of calls**, which is exactly what we are doing in this checker. CallEvent is used for this exact purpose elsewhere throughout the analyzer. What do you mean by "touching  the CallEvent allocator" and why would you want to discourage that?

CallEventManager::getCaller contains logic to dispatch to different CallEvent types depending on what call we are dealing with. The argument lookup will depend on type of the call. The method added in this PR does not deal with all call types, but only with CallExpr, so you'd need to duplicate the code from CallEvent construction to here.

As I've mentioned before, I do not think that Call dispatch logic and API for looking up arguments SVals should belong to ProgramState as it is a higher abstraction and should not reason about LocationContexts or Calls (which are part of Program Location and AST respectively). In addition, using CallEven to look up argument values is much simpler to understand for API users.


https://reviews.llvm.org/D27091