When the solver and SValBuilder cannot reason about symbolic expressions (ex: (x+1)*y ), the analyzer conjures a new symbol with no ties to the past. This helps it to recover some path-sensitivity. However, this breaks the taint propagation.
With this commit, we are going to construct the expression even if we cannot reason about it later on if an operand is tainted.
Also added some comments and asserts.
llvm-svn: 144932
Change the ArrayBoundCheckerV2 to be more aggressive in reporting buffer overflows
when the offset is tainted. Previously, we did not report bugs when the state was
underconstrained (not enough information about the bound to determine if there is
an overflow) to avoid false positives. However, if we know that the buffer
offset is tainted - comes in from the user space and can be anything, we should
report it as a bug.
+ The very first example of us catching a taint related bug.
This is the only example we can currently handle. More to come...
llvm-svn: 144826
Anna Zaks