[analyzer] This patch removes passing around of const-invalidation vs regular-invalidation info by passing around a datastructure that maps regions and symbols to the type of invalidation they experience. This simplifies the code and would allow to associate more different invalidation types in the future.

With this patch things like preserving contents of regions (either hi- or low-level ones) or processing of the only top-level region can be implemented easily without passing around extra parameters.

This patch is a first step towards adequate modeling of memcpy() by the CStringChecker checker and towards eliminating of majority of false-positives produced by the NewDeleteLeaks checker.

llvm-svn: 191342

1 files changed, 8 insertions, 5 deletions

diff --git a/clang/lib/StaticAnalyzer/Core/CallEvent.cpp b/clang/lib/StaticAnalyzer/Core/CallEvent.cpp
index 64a4f8d69e2..556f93b7cfb 100644
--- a/clang/lib/StaticAnalyzer/Core/CallEvent.cpp
+++ b/clang/lib/StaticAnalyzer/Core/CallEvent.cpp
@@ -140,8 +140,8 @@ ProgramStateRef CallEvent::invalidateRegions(unsigned BlockCount,
                                              ProgramStateRef Orig) const {
   ProgramStateRef Result = (Orig ? Orig : getState());
 
-  SmallVector<SVal, 8> ConstValues;
   SmallVector<SVal, 8> ValuesToInvalidate;
+  RegionAndSymbolInvalidationTraits ETraits;
 
   getExtraInvalidatedValues(ValuesToInvalidate);
 
@@ -154,9 +154,12 @@ ProgramStateRef CallEvent::invalidateRegions(unsigned BlockCount,
     // Mark this region for invalidation.  We batch invalidate regions
     // below for efficiency.
     if (PreserveArgs.count(Idx))
-      ConstValues.push_back(getArgSVal(Idx));
-    else
-      ValuesToInvalidate.push_back(getArgSVal(Idx));
+      if (const MemRegion *MR = getArgSVal(Idx).getAsRegion())
+        ETraits.setTrait(MR->StripCasts(), 
+                        RegionAndSymbolInvalidationTraits::TK_PreserveContents);
+        // TODO: Factor this out + handle the lower level const pointers.
+
+    ValuesToInvalidate.push_back(getArgSVal(Idx));
   }
 
   // Invalidate designated regions using the batch invalidation API.
@@ -165,7 +168,7 @@ ProgramStateRef CallEvent::invalidateRegions(unsigned BlockCount,
   return Result->invalidateRegions(ValuesToInvalidate, getOriginExpr(),
                                    BlockCount, getLocationContext(),
                                    /*CausedByPointerEscape*/ true,
-                                   /*Symbols=*/0, this, ConstValues);
+                                   /*Symbols=*/0, this, &ETraits);
 }
 
 ProgramPoint CallEvent::getProgramPoint(bool IsPreVisit,