value by scanning the path, rather than assuming we have visited the '?:' operator
as a terminator (which sets a value indicating which expression to grab the
final ternary expression value from).
llvm-svn: 160760
as a result of a call.
Problem:
Global variables, which come in from system libraries should not be
invalidated by all calls. Also, non-system globals should not be
invalidated by system calls.
Solution:
The following solution to invalidation of globals seems flexible enough
for taint (does not invalidate stdin) and should not lead to too
many false positives. We split globals into 3 classes:
* immutable - values are preserved by calls (unless the specific
global is passed in as a parameter):
A : Most system globals and const scalars
* invalidated by functions defined in system headers:
B: errno
* invalidated by all other functions (note, these functions may in
turn contain system calls):
B: errno
C: all other globals (which are not in A nor B)
llvm-svn: 147569
Also, have Environment stop looking through NoOp casts; it didn't match the behavior of LiveVariables. And once that's gone, the whole cast block of that switch is unnecessary.
llvm-svn: 132840