[analyzer] Make the entries in 'Environment' context-sensitive by making entries map from

(Stmt*,LocationContext*) pairs to SVals instead of Stmt* to SVals.

This is needed to support basic IPA via inlining.  Without this, we cannot tell
if a Stmt* binding is part of the current analysis scope (StackFrameContext) or
part of a parent context.

This change introduces an uglification of the use of getSVal(), and thus takes
two steps forward and one step back.  There are also potential performance implications
of enlarging the Environment.  Both can be addressed going forward by refactoring the
APIs and optimizing the internal representation of Environment.  This patch
mainly introduces the functionality upon when we want to build upon (and clean up).

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@147688 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 8 insertions, 4 deletions

diff --git a/lib/StaticAnalyzer/Checkers/UndefBranchChecker.cpp b/lib/StaticAnalyzer/Checkers/UndefBranchChecker.cpp
index afb79b5d16..fc0b9c2ec6 100644
--- a/lib/StaticAnalyzer/Checkers/UndefBranchChecker.cpp
+++ b/lib/StaticAnalyzer/Checkers/UndefBranchChecker.cpp
@@ -28,8 +28,10 @@ class UndefBranchChecker : public Checker<check::BranchCondition> {
 
   struct FindUndefExpr {
     const ProgramState *St;
+    const LocationContext *LCtx;
 
-    FindUndefExpr(const ProgramState *S) : St(S) {}
+    FindUndefExpr(const ProgramState *S, const LocationContext *L) 
+      : St(S), LCtx(L) {}
 
     const Expr *FindExpr(const Expr *Ex) {
       if (!MatchesCriteria(Ex))
@@ -45,7 +47,9 @@ class UndefBranchChecker : public Checker<check::BranchCondition> {
       return Ex;
     }
 
-    bool MatchesCriteria(const Expr *Ex) { return St->getSVal(Ex).isUndef(); }
+    bool MatchesCriteria(const Expr *Ex) { 
+      return St->getSVal(Ex, LCtx).isUndef();
+    }
   };
 
 public:
@@ -56,7 +60,7 @@ public:
 
 void UndefBranchChecker::checkBranchCondition(const Stmt *Condition,
                                               CheckerContext &Ctx) const {
-  SVal X = Ctx.getState()->getSVal(Condition);
+  SVal X = Ctx.getState()->getSVal(Condition, Ctx.getLocationContext());
   if (X.isUndef()) {
     // Generate a sink node, which implicitly marks both outgoing branches as
     // infeasible.
@@ -90,7 +94,7 @@ void UndefBranchChecker::checkBranchCondition(const Stmt *Condition,
         if (PS->getStmt() == Ex)
           St = PrevN->getState();
 
-      FindUndefExpr FindIt(St);
+      FindUndefExpr FindIt(St, Ctx.getLocationContext());
       Ex = FindIt.FindExpr(Ex);
 
       // Emit the bug report.