[cfe-commits] r170969 - /cfe/trunk/lib/StaticAnalyzer/Checkers/SimpleStreamChecker.cpp
Anna Zaks
ganna at apple.com
Fri Dec 21 16:18:39 PST 2012
Author: zaks
Date: Fri Dec 21 18:18:39 2012
New Revision: 170969
URL: http://llvm.org/viewvc/llvm-project?rev=170969&view=rev
Log:
[analyzer] Convert SimpleStreamChecker to use the PointerEscape callback
The new callback greatly simplifies the checker.
Modified:
cfe/trunk/lib/StaticAnalyzer/Checkers/SimpleStreamChecker.cpp
Modified: cfe/trunk/lib/StaticAnalyzer/Checkers/SimpleStreamChecker.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/StaticAnalyzer/Checkers/SimpleStreamChecker.cpp?rev=170969&r1=170968&r2=170969&view=diff
==============================================================================
--- cfe/trunk/lib/StaticAnalyzer/Checkers/SimpleStreamChecker.cpp (original)
+++ cfe/trunk/lib/StaticAnalyzer/Checkers/SimpleStreamChecker.cpp Fri Dec 21 18:18:39 2012
@@ -50,8 +50,7 @@
class SimpleStreamChecker : public Checker<check::PostCall,
check::PreCall,
check::DeadSymbols,
- check::Bind,
- check::RegionChanges> {
+ check::PointerEscape> {
mutable IdentifierInfo *IIfopen, *IIfclose;
@@ -80,20 +79,10 @@
void checkDeadSymbols(SymbolReaper &SymReaper, CheckerContext &C) const;
- /// Deal with symbol escape as a byproduct of a bind.
- void checkBind(SVal location, SVal val, const Stmt*S,
- CheckerContext &C) const;
-
- /// Deal with symbol escape as a byproduct of a region change.
- ProgramStateRef
- checkRegionChanges(ProgramStateRef state,
- const InvalidatedSymbols *invalidated,
- ArrayRef<const MemRegion *> ExplicitRegions,
- ArrayRef<const MemRegion *> Regions,
- const CallEvent *Call) const;
- bool wantsRegionChangeUpdate(ProgramStateRef state) const {
- return true;
- }
+ /// Stop tracking addresses which escape.
+ ProgramStateRef checkPointerEscape(ProgramStateRef State,
+ const InvalidatedSymbols &Escaped,
+ const CallEvent *Call) const;
};
} // end anonymous namespace
@@ -246,45 +235,6 @@
}
}
-// Check various ways a symbol can be invalidated.
-// Stop tracking symbols when a value escapes as a result of checkBind.
-// A value escapes in three possible cases:
-// (1) We are binding to something that is not a memory region.
-// (2) We are binding to a MemRegion that does not have stack storage
-// (3) We are binding to a MemRegion with stack storage that the store
-// does not understand.
-void SimpleStreamChecker::checkBind(SVal loc, SVal val, const Stmt *S,
- CheckerContext &C) const {
- // Are we storing to something that causes the value to "escape"?
- bool escapes = true;
- ProgramStateRef state = C.getState();
-
- if (loc::MemRegionVal *regionLoc = dyn_cast<loc::MemRegionVal>(&loc)) {
- escapes = !regionLoc->getRegion()->hasStackStorage();
-
- if (!escapes) {
- // To test (3), generate a new state with the binding added. If it is
- // the same state, then it escapes (since the store cannot represent
- // the binding). Do this only if we know that the store is not supposed
- // to generate the same state.
- SVal StoredVal = state->getSVal(regionLoc->getRegion());
- if (StoredVal != val)
- escapes = (state == (state->bindLoc(*regionLoc, val)));
- }
- }
-
- // If our store can represent the binding and we aren't storing to something
- // that doesn't have local storage then just return the state and
- // continue as is.
- if (!escapes)
- return;
-
- // Otherwise, find all symbols referenced by 'val' that we are tracking
- // and stop tracking them.
- state = state->scanReachableSymbols<StopTrackingCallback>(val).getState();
- C.addTransition(state);
-}
-
bool SimpleStreamChecker::guaranteedNotToCloseFile(const CallEvent &Call) const{
// If it's not in a system header, assume it might close a file.
if (!Call.isInSystemHeader())
@@ -300,38 +250,24 @@
return true;
}
-// If the symbol we are tracking is invalidated, do not track the symbol as
+// If the pointer we are tracking escaped, do not track the symbol as
// we cannot reason about it anymore.
ProgramStateRef
-SimpleStreamChecker::checkRegionChanges(ProgramStateRef State,
- const InvalidatedSymbols *invalidated,
- ArrayRef<const MemRegion *> ExplicitRegions,
- ArrayRef<const MemRegion *> Regions,
- const CallEvent *Call) const {
-
- if (!invalidated || invalidated->empty())
+SimpleStreamChecker::checkPointerEscape(ProgramStateRef State,
+ const InvalidatedSymbols &Escaped,
+ const CallEvent *Call) const {
+ // If we know that the call cannot close a file, there is nothing to do.
+ if (Call && guaranteedNotToCloseFile(*Call))
return State;
- // If it's a call which might close the file, we assume that all regions
- // (explicit and implicit) escaped. Otherwise, whitelist explicit pointers
- // (the parameters to the call); we still can track them.
- llvm::SmallPtrSet<SymbolRef, 8> WhitelistedSymbols;
- if (!Call || guaranteedNotToCloseFile(*Call)) {
- for (ArrayRef<const MemRegion *>::iterator I = ExplicitRegions.begin(),
- E = ExplicitRegions.end(); I != E; ++I) {
- if (const SymbolicRegion *R = (*I)->StripCasts()->getAs<SymbolicRegion>())
- WhitelistedSymbols.insert(R->getSymbol());
- }
- }
+ for (InvalidatedSymbols::const_iterator I = Escaped.begin(),
+ E = Escaped.end();
+ I != E; ++I) {
+ SymbolRef Sym = *I;
- for (InvalidatedSymbols::const_iterator I=invalidated->begin(),
- E = invalidated->end(); I!=E; ++I) {
- SymbolRef sym = *I;
- if (WhitelistedSymbols.count(sym))
- continue;
// The symbol escaped. Optimistically, assume that the corresponding file
// handle will be closed somewhere else.
- State = State->remove<StreamMap>(sym);
+ State = State->remove<StreamMap>(Sym);
}
return State;
}
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