NoQ added a comment.

An idea. I believe the safest way to find the bugs you mentioned would be to 
replace extent-as-a-symbol with extent-as-a-trait.

I.e., currently we construct `extent_$3{SymRegion{conj_$1{char *}}}`, assume 
that it is equal to `reg_$0<int X>` (which produces a `SymSymExpr`) and then 
catch more `SymSymExpr`s along the path and compare them to the first one.

Instead, i believe that from the start we should have done something like

  REGISTER_MAP_WITH_PROGRAMSTATE(RegionExtent, const SubRegion *, NonLoc);

Then when the VLA is constructed (or memory is malloc'ed or something like 
that), we just set the `RegionExtent` trait directly to `reg_$0<int X>` and 
later easily compare it to anything. The region's `getExtent()` method would be 
modified to consult this trait instead of (or, at least, before) constructing a 
new symbol.

Ideologically it is the same thing. Technically it produces simpler symbolic 
expressions, and i believe that both RangeConstraintManager and Z3 would 
benefit from simpler symbolic expressions.


Repository:
  rL LLVM

https://reviews.llvm.org/D30489



_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
  • [PATCH] D30489: [analyzer]... Artem Dergachev via Phabricator via cfe-commits

Reply via email to