[PATCH] D110927: [analyzer] Access stored value of a constant array through a pointer to another type

Fri Oct 1 08:21:17 PDT 2021

ASDenysPetrov added a comment.

In D110927#3036436 <https://reviews.llvm.org/D110927#3036436>, @steakhal wrote:

> I'm pretty sure that `int x4 = ((char*)arr)[1];` is supposed to be valid in your summary.
> I think it's allowed by the standard to access any valid object via a `char*` - according to the strict aliasing rule.
> @shafik WDYT?

As I found we can legaly treat `char*` as the object of type `char` but not as an array of objects. This is mentioned in http://eel.is/c++draft/basic.compound#3.4 //For purposes of pointer arithmetic ... an object of type T that is not an array element is considered to belong to an array with one element of type T.// That means that we can get only the first element of `char*`, otherwise it would be an UB.

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