Add "KnownSVal" to represent SVals that cannot be UnknownSVal.

This provides a few sundry cleanups, and allows us to provide
a compile-time check for a case that was a runtime assertion.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@175987 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 19 insertions, 9 deletions

diff --git a/include/clang/StaticAnalyzer/Core/BugReporter/BugReporterVisitor.h b/include/clang/StaticAnalyzer/Core/BugReporter/BugReporterVisitor.h
index 75bf9613e2..bef4b30a35 100644
--- a/include/clang/StaticAnalyzer/Core/BugReporter/BugReporterVisitor.h
+++ b/include/clang/StaticAnalyzer/Core/BugReporter/BugReporterVisitor.h
@@ -99,7 +99,7 @@ class FindLastStoreBRVisitor
 {
   const MemRegion *R;
   SVal V;
-  bool satisfied;
+  bool Satisfied;
 
 public:
   /// \brief Convenience method to create a visitor given only the MemRegion.
@@ -112,13 +112,10 @@ public:
   /// the BugReport.
   static void registerStatementVarDecls(BugReport &BR, const Stmt *S);
 
-  FindLastStoreBRVisitor(SVal v, const MemRegion *r)
-  : R(r), V(v), satisfied(false) {
-    assert (!V.isUnknown() && "Cannot track unknown value.");
-
-    // TODO: Does it make sense to allow undef values here?
-    // (If not, also see UndefCapturedBlockVarChecker)?
-  }
+  FindLastStoreBRVisitor(KnownSVal V, const MemRegion *R)
+  : R(R),
+    V(V),
+    Satisfied(false) {}
 
   void Profile(llvm::FoldingSetNodeID &ID) const;
 
diff --git a/include/clang/StaticAnalyzer/Core/PathSensitive/SVals.h b/include/clang/StaticAnalyzer/Core/PathSensitive/SVals.h
index 31d02f51ea..03e84447e7 100644
--- a/include/clang/StaticAnalyzer/Core/PathSensitive/SVals.h
+++ b/include/clang/StaticAnalyzer/Core/PathSensitive/SVals.h
@@ -219,7 +219,7 @@ public:
   
 private:
   friend class SVal;
-  static bool isKind(const SVal& V) {
+  static bool isKind(const SVal &V) {
     return V.getBaseKind() == UnknownKind;
   }
 };
@@ -242,6 +242,19 @@ private:
   }
 };
 
+
+/// \brief Represents an SVal that is guaranteed to not be UnknownVal.
+class KnownSVal : public SVal {
+  KnownSVal() {}
+  friend class SVal;
+  static bool isKind(const SVal &V) {
+    return !V.isUnknown();
+  }
+public:
+  KnownSVal(const DefinedSVal &V) : SVal(V) {}
+  KnownSVal(const UndefinedVal &V) : SVal(V) {}
+};
+
 class NonLoc : public DefinedSVal {
 protected:
   NonLoc() {}