[PATCH] D103440: [WIP][analyzer] Introduce range-based reasoning for addition operator

[Manas Gupta via Phabricator via cfe-commits]

manas added inline comments.


================
Comment at: clang/lib/StaticAnalyzer/Core/RangeConstraintManager.cpp:1400
+  if (ResultType.isUnsigned()) {
+    LHS.From().uadd_ov(RHS.From(), HasMinOverflowed);
+    LHS.To().uadd_ov(RHS.To(), HasMaxOverflowed);
----------------
Using `uadd_ov` (and `sadd_ov`), we can get the added value as well as whether overflow occurred or not. A point is that these functions return `APInt` instead of `APSInt`.

But when I tried just using:
  Min = LHS.From().uadd_ov(RHS.From(), HasMinOverflowed);
  Max = LHS.To().uadd_ov(RHS.From(), HasMaxOverflowed);

instead of
  Min = LHS.From() + RHS.From();
  Max = LHS.To() + RHS.To();

just for the added value, then the following tests failed (//these tests and all other tests pass when I use the latter method to get Min/Max//):                                                            
  Clang :: Analysis/PR3991.m
  Clang :: Analysis/global-region-invalidation.c
  Clang :: Analysis/malloc-overflow2.c
  Clang :: Analysis/out-of-bounds-new.cpp
  Clang :: Analysis/taint-generic.c

I am working on fixing this part.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D103440/new/

https://reviews.llvm.org/D103440