[PATCH] D84316: [analyzer][NFC] Split CStringChecker to modeling and reporting

[19n07u5 via Phabricator via cfe-commits]

19n07u5 added a comment.

The title is a little bit confusing because only the C-string size model is going to be separated and be accessible. Other than that as @NoQ pointed out we need lot more of these common-API-separation patches. It is a great starting point for the `CStringChecker`.



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Comment at: clang/lib/StaticAnalyzer/Checkers/CMakeLists.txt:146
+  CStringChecker
+  )
----------------
Other common checker functionality folders and headers do not require extra CMake support long ago. I think when we need such support, we could define it later, so that you could revert this.


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Comment at: clang/lib/StaticAnalyzer/Checkers/CStringChecker/CStringLength.h:43
+                                     ProgramStateRef &State, const Expr *Ex,
+                                     SVal Buf, bool Hypothetical = false);
+
----------------
steakhal wrote:
> steakhal wrote:
> > steakhal wrote:
> > > balazske wrote:
> > > > I do not like that the //get// and //set// (CStringLength) functions are not symmetrical. I (and other developers) would think that the get function returns a stored value and the set function sets it. The `getCStringLength` is more a `computeCStringLength` and additionally may manipulate the `State` too. In this form it is usable mostly only for CStringChecker. (A separate function to get the value stored in the length map should exist instead of this `Hypothetical` thing.)
> > > > [...] get function returns a stored value and the set function sets it.
> > > Certainly a burden to understand. It would be more appealing, but more useful?
> > > The user would have to check and create if necessary regardless. So fusing these two functions is more like a feature.
> > > What use case do you think of using only the query function? In other words, how can you guarantee that you will find a length for a symbol?
> > > 
> > > > In this form it is usable mostly only for CStringChecker. (A separate function to get the value stored in the length map should exist instead of this Hypothetical thing.)
> > > You are right. However, I want to focus on splitting parts without modifying the already existing API reducing the risk of breaking things.
> > > You should expect such a change in an upcoming patch.
> > On second thought, It probably worth having a cleaner API to a slight inconvenience. If he feels like, still can wrap them.
> > I will investigate it tomorrow.
> I made a separate patch for cleansing this API.
> In the D84979 now these API functions will behave as expected.
> I (and other developers) would think that the get function returns a stored value and the set function sets it.
Developers should not believe the getters are pure getters. As a checker-writer point of view, you do not care whether the C-string already exist or the checker creates it during symbolic execution, you only want to get the C-string.

Think about all the Static Analyzer getters as factory functions, that is the de facto standard now. For example, when you are trying to get a symbolic value with `getSVal()`, for the first occurrence of an expression no `SVal` exist, so it also creates it.

With that in mind, @steakhal, could you partially revert the renaming related refactors of D84979, please?


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  https://reviews.llvm.org/D84316/new/

https://reviews.llvm.org/D84316