[analyzer] Be less pessimistic about invalidation of global variables

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)

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@147569 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 5 insertions, 5 deletions

diff --git a/include/clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h b/include/clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h
index 700a26505b..e9d6d6ec96 100644
--- a/include/clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h
+++ b/include/clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h
@@ -34,8 +34,8 @@ class ASTContext;
 
 namespace ento {
 
+class CallOrObjCMessage;
 class ProgramStateManager;
-
 typedef ConstraintManager* (*ConstraintManagerCreator)(ProgramStateManager&,
                                                        SubEngine&);
 typedef StoreManager* (*StoreManagerCreator)(ProgramStateManager&);
@@ -219,9 +219,9 @@ public:
   ///  cleared from the store. The regions are provided as a continuous array
   ///  from Begin to End. Optionally invalidates global regions as well.
   const ProgramState *invalidateRegions(ArrayRef<const MemRegion *> Regions,
-                                   const Expr *E, unsigned BlockCount,
-                                   StoreManager::InvalidatedSymbols *IS = 0,
-                                   bool invalidateGlobals = false) const;
+                               const Expr *E, unsigned BlockCount,
+                               StoreManager::InvalidatedSymbols *IS = 0,
+                               const CallOrObjCMessage *Call = 0) const;
 
   /// enterStackFrame - Returns the state for entry to the given stack frame,
   ///  preserving the current state.
@@ -384,7 +384,7 @@ private:
   invalidateRegionsImpl(ArrayRef<const MemRegion *> Regions,
                         const Expr *E, unsigned BlockCount,
                         StoreManager::InvalidatedSymbols &IS,
-                        bool invalidateGlobals) const;
+                        const CallOrObjCMessage *Call) const;
 };
 
 class ProgramStateSet {