Add analysis support for blocks. This includes a few key changes:

- Refactor the MemRegion hierarchy to distinguish between different StackSpaceRegions for locals and parameters.
- VarRegions for "captured" variables now have the BlockDataRegion as their super region (except those passed by reference)
- Add transfer function support to GRExprEngine for BlockDeclRefExprs.

This change also supports analyzing blocks as an analysis entry point
(top-of-the-stack), which required pushing more context-sensitivity
around in the MemRegion hierarchy via the use of LocationContext
objects.  Functionally almost everything is the same, except we track
LocationContexts in a few more areas and StackSpaceRegions now refer
to a StackFrameContext object.  In the future we will need to modify
MemRegionManager to allow multiple StackSpaceRegions in flight at once
(for the analysis of multiple stack frames).


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@90809 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 18 insertions, 1 deletions

diff --git a/lib/Analysis/CFRefCount.cpp b/lib/Analysis/CFRefCount.cpp
index 288645d227..1df4f7cb51 100644
--- a/lib/Analysis/CFRefCount.cpp
+++ b/lib/Analysis/CFRefCount.cpp
@@ -3681,7 +3681,24 @@ void RetainReleaseChecker::PostVisitBlockExpr(CheckerContext &C,
   if (I == E)
     return;
   
-  state = state->scanReachableSymbols<StopTrackingCallback>(I, E).getState();
+  // FIXME: For now we invalidate the tracking of all symbols passed to blocks
+  // via captured variables, even though captured variables result in a copy
+  // and in implicit increment/decrement of a retain count.
+  llvm::SmallVector<const MemRegion*, 10> Regions;
+  const LocationContext *LC = C.getPredecessor()->getLocationContext();
+  MemRegionManager &MemMgr = C.getValueManager().getRegionManager();
+  
+  for ( ; I != E; ++I) {
+    const VarRegion *VR = *I;
+    if (VR->getSuperRegion() == R) {
+      VR = MemMgr.getVarRegion(VR->getDecl(), LC);
+    }
+    Regions.push_back(VR);
+  }
+  
+  state =
+    state->scanReachableSymbols<StopTrackingCallback>(Regions.data(),
+                                    Regions.data() + Regions.size()).getState();
   C.addTransition(state);
 }