Refactor static analyzer to use simpler interface to constant expression evaluation.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@141983 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 17 insertions, 42 deletions

diff --git a/lib/Analysis/CFG.cpp b/lib/Analysis/CFG.cpp
index 0b2577dec4..83c7384db0 100644
--- a/lib/Analysis/CFG.cpp
+++ b/lib/Analysis/CFG.cpp
@@ -437,20 +437,12 @@ private:
   /// tryEvaluateBool - Try and evaluate the Stmt and return 0 or 1
   /// if we can evaluate to a known value, otherwise return -1.
   TryResult tryEvaluateBool(Expr *S) {
-    Expr::EvalResult Result;
-    if (!tryEvaluate(S, Result))
+    bool Result;
+    if (!BuildOpts.PruneTriviallyFalseEdges ||
+        S->isTypeDependent() || S->isValueDependent() ||
+        !S->EvaluateAsBooleanCondition(Result, *Context))
       return TryResult();
-    
-    if (Result.Val.isInt())
-      return Result.Val.getInt().getBoolValue();
-
-    if (Result.Val.isLValue()) {
-      const Expr *e = Result.Val.getLValueBase();
-      const CharUnits &c = Result.Val.getLValueOffset();        
-      if (!e && c.isZero())
-        return false;        
-    }
-    return TryResult();
+    return Result;
   }
   
 };
@@ -2343,11 +2335,8 @@ static bool shouldAddCase(bool &switchExclusivelyCovered,
   if (!switchExclusivelyCovered) {
     if (switchCond->Val.isInt()) {
       // Evaluate the LHS of the case value.
-      Expr::EvalResult V1;
-      CS->getLHS()->Evaluate(V1, Ctx);
-      assert(V1.Val.isInt());
+      const llvm::APSInt &lhsInt = CS->getLHS()->EvaluateKnownConstInt(Ctx);
       const llvm::APSInt &condInt = switchCond->Val.getInt();
-      const llvm::APSInt &lhsInt = V1.Val.getInt();
       
       if (condInt == lhsInt) {
         addCase = true;
@@ -2356,10 +2345,8 @@ static bool shouldAddCase(bool &switchExclusivelyCovered,
       else if (condInt < lhsInt) {
         if (const Expr *RHS = CS->getRHS()) {
           // Evaluate the RHS of the case value.
-          Expr::EvalResult V2;
-          RHS->Evaluate(V2, Ctx);
-          assert(V2.Val.isInt());
-          if (V2.Val.getInt() <= condInt) {
+          const llvm::APSInt &V2 = RHS->EvaluateKnownConstInt(Ctx);
+          if (V2 <= condInt) {
             addCase = true;
             switchExclusivelyCovered = true;
           }
diff --git a/lib/StaticAnalyzer/Core/ExprEngine.cpp b/lib/StaticAnalyzer/Core/ExprEngine.cpp
index 5489c10bba..ac9cf0b08d 100644
--- a/lib/StaticAnalyzer/Core/ExprEngine.cpp
+++ b/lib/StaticAnalyzer/Core/ExprEngine.cpp
@@ -1086,25 +1086,13 @@ void ExprEngine::processSwitch(SwitchNodeBuilder& builder) {
     const CaseStmt *Case = I.getCase();
 
     // Evaluate the LHS of the case value.
-    Expr::EvalResult V1;
-    bool b = Case->getLHS()->Evaluate(V1, getContext());
-
-    // Sanity checks.  These go away in Release builds.
-    assert(b && V1.Val.isInt() && !V1.HasSideEffects
-             && "Case condition must evaluate to an integer constant.");
-    (void)b; // silence unused variable warning
-    assert(V1.Val.getInt().getBitWidth() ==
-           getContext().getTypeSize(CondE->getType()));
+    llvm::APSInt V1 = Case->getLHS()->EvaluateKnownConstInt(getContext());
+    assert(V1.getBitWidth() == getContext().getTypeSize(CondE->getType()));
 
     // Get the RHS of the case, if it exists.
-    Expr::EvalResult V2;
-
-    if (const Expr *E = Case->getRHS()) {
-      b = E->Evaluate(V2, getContext());
-      assert(b && V2.Val.isInt() && !V2.HasSideEffects
-             && "Case condition must evaluate to an integer constant.");
-      (void)b; // silence unused variable warning
-    }
+    llvm::APSInt V2;
+    if (const Expr *E = Case->getRHS())
+      V2 = E->EvaluateKnownConstInt(getContext());
     else
       V2 = V1;
 
@@ -1113,7 +1101,7 @@ void ExprEngine::processSwitch(SwitchNodeBuilder& builder) {
     //  This should be easy once we have "ranges" for NonLVals.
 
     do {
-      nonloc::ConcreteInt CaseVal(getBasicVals().getValue(V1.Val.getInt()));
+      nonloc::ConcreteInt CaseVal(getBasicVals().getValue(V1));
       DefinedOrUnknownSVal Res = svalBuilder.evalEQ(DefaultSt ? DefaultSt : state,
                                                CondV, CaseVal);
 
@@ -1142,11 +1130,11 @@ void ExprEngine::processSwitch(SwitchNodeBuilder& builder) {
       }
 
       // Concretize the next value in the range.
-      if (V1.Val.getInt() == V2.Val.getInt())
+      if (V1 == V2)
         break;
 
-      ++V1.Val.getInt();
-      assert (V1.Val.getInt() <= V2.Val.getInt());
+      ++V1;
+      assert (V1 <= V2);
 
     } while (true);
   }