[PATCH] D35110: [Analyzer] Constraint Manager Negates Difference

[Artem Dergachev via Phabricator via cfe-commits]

NoQ added inline comments.


================
Comment at: lib/StaticAnalyzer/Core/RangeConstraintManager.cpp:265-276
+      const llvm::APSInt &from = i->From(), &to = i->To();
+      const llvm::APSInt &newFrom = (to.isMinSignedValue() ?
+                                     BV.getMaxValue(to) :
+                                     (to.isMaxSignedValue() ?
+                                      BV.getMinValue(to) :
+                                      BV.getValue(- to)));
+      const llvm::APSInt &newTo = (from.isMinSignedValue() ?
----------------
Hmm, wait a minute, is this actually correct?

For the range [-2³¹, -2³¹ + 1] over a 32-bit integer, the negated range will be [-2³¹, -2³¹] U [2³¹ - 1, 2³¹ - 1].

So there must be a place in the code where we take one range and add two ranges.


https://reviews.llvm.org/D35110