[PATCH] D85752: [Analyzer] Store the pointed/referenced type for dynamic casts

[Artem Dergachev via Phabricator via cfe-commits]

NoQ accepted this revision.
NoQ added inline comments.
This revision is now accepted and ready to land.


================
Comment at: clang/lib/StaticAnalyzer/Core/DynamicType.cpp:73
+    Ty = STTPTy->getReplacementType();
+  if (Ty->isPointerType())
+    Ty = Ty->getPointeeType();
----------------
baloghadamsoftware wrote:
> xazax.hun wrote:
> > Is this doing what you intended? What about a reference to a pointer? Wouldn't you do too much unboxing? 
> > 
> > Also, I think a function returning a value would be more conventional. 
> > 
> > Other sugars like typedefs cannot interfere? I think this patch might benefit from additional test coverage. I also see no tests for template substitutions.
> Reference to pointer cast using //LLVM//'s cast functions are syntactically invalid, they do not compile.
> 
> For `QualType` in-place modification is usual, since we use it by value.
> 
> I see no test coverage for this particular part of the analyzer specifically, it seems that its is only tested indirectly in the tests for `CastValueChecker`.
The usual idiom is
```lang=c++
if (Ty->isPointerType() || Ty->isReferenceType())
  Ty = Ty->getPointeeType();
```
It makes sure that you don't unwrap things twice. Also there's no need to canonicalize before unwrapping the pointee type; all these methods automatically operate over the canonical type.

You might want to add tests for typedefs.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D85752/new/

https://reviews.llvm.org/D85752