r290415 - Revert changes made by r290413 until regression is fixed.

[Anton Yartsev via cfe-commits]

Author: ayartsev
Date: Thu Dec 22 22:09:18 2016
New Revision: 290415

URL: http://llvm.org/viewvc/llvm-project?rev=290415&view=rev
Log:
Revert changes made by r290413 until regression is fixed.

Modified:
    cfe/trunk/lib/StaticAnalyzer/Core/ExprEngineC.cpp
    cfe/trunk/lib/StaticAnalyzer/Core/SimpleConstraintManager.cpp
    cfe/trunk/test/Analysis/malloc.c
    cfe/trunk/test/Analysis/misc-ps.c

Modified: cfe/trunk/lib/StaticAnalyzer/Core/ExprEngineC.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/StaticAnalyzer/Core/ExprEngineC.cpp?rev=290415&r1=290414&r2=290415&view=diff
==============================================================================
--- cfe/trunk/lib/StaticAnalyzer/Core/ExprEngineC.cpp (original)
+++ cfe/trunk/lib/StaticAnalyzer/Core/ExprEngineC.cpp Thu Dec 22 22:09:18 2016
@@ -665,13 +665,23 @@ void ExprEngine::VisitLogicalExpr(const
     if (RHSVal.isUndef()) {
       X = RHSVal;
     } else {
-      // We evaluate "RHSVal != 0" expression which result in 0 if the value is
-      // known to be false, 1 if the value is known to be true and a new symbol
-      // when the assumption is unknown.
-      nonloc::ConcreteInt Zero(getBasicVals().getValue(0, B->getType()));
-      X = evalBinOp(N->getState(), BO_NE, 
-                    svalBuilder.evalCast(RHSVal, B->getType(), RHS->getType()),
-                    Zero, B->getType());
+      DefinedOrUnknownSVal DefinedRHS = RHSVal.castAs<DefinedOrUnknownSVal>();
+      ProgramStateRef StTrue, StFalse;
+      std::tie(StTrue, StFalse) = N->getState()->assume(DefinedRHS);
+      if (StTrue) {
+        if (StFalse) {
+          // We can't constrain the value to 0 or 1.
+          // The best we can do is a cast.
+          X = getSValBuilder().evalCast(RHSVal, B->getType(), RHS->getType());
+        } else {
+          // The value is known to be true.
+          X = getSValBuilder().makeIntVal(1, B->getType());
+        }
+      } else {
+        // The value is known to be false.
+        assert(StFalse && "Infeasible path!");
+        X = getSValBuilder().makeIntVal(0, B->getType());
+      }
     }
   }
   Bldr.generateNode(B, Pred, state->BindExpr(B, Pred->getLocationContext(), X));

Modified: cfe/trunk/lib/StaticAnalyzer/Core/SimpleConstraintManager.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/StaticAnalyzer/Core/SimpleConstraintManager.cpp?rev=290415&r1=290414&r2=290415&view=diff
==============================================================================
--- cfe/trunk/lib/StaticAnalyzer/Core/SimpleConstraintManager.cpp (original)
+++ cfe/trunk/lib/StaticAnalyzer/Core/SimpleConstraintManager.cpp Thu Dec 22 22:09:18 2016
@@ -254,21 +254,6 @@ ProgramStateRef SimpleConstraintManager:
   assert(BinaryOperator::isComparisonOp(Op) &&
          "Non-comparison ops should be rewritten as comparisons to zero.");
 
-  SymbolRef Sym = LHS;
-
-  // Simplification: translate an assume of a constraint of the form
-  // "(exp comparison_op expr) != 0" to true into an assume of 
-  // "exp comparison_op expr" to true. (And similarly, an assume of the form
-  // "(exp comparison_op expr) == 0" to true into an assume of
-  // "exp comparison_op expr" to false.)
-  if (Int == 0 && (Op == BO_EQ || Op == BO_NE)) {
-    if (const BinarySymExpr *SE = dyn_cast<BinarySymExpr>(Sym)) {
-      BinaryOperator::Opcode Op = SE->getOpcode();
-      if (BinaryOperator::isComparisonOp(Op))
-        return assume(State, nonloc::SymbolVal(Sym), (Op == BO_NE ? true : false));
-    }
-  }
-
   // Get the type used for calculating wraparound.
   BasicValueFactory &BVF = getBasicVals();
   APSIntType WraparoundType = BVF.getAPSIntType(LHS->getType());
@@ -280,6 +265,7 @@ ProgramStateRef SimpleConstraintManager:
   // x < 4 has the solution [0, 3]. x+2 < 4 has the solution [0-2, 3-2], which
   // in modular arithmetic is [0, 1] U [UINT_MAX-1, UINT_MAX]. It's up to
   // the subclasses of SimpleConstraintManager to handle the adjustment.
+  SymbolRef Sym = LHS;
   llvm::APSInt Adjustment = WraparoundType.getZeroValue();
   computeAdjustment(Sym, Adjustment);
 

Modified: cfe/trunk/test/Analysis/malloc.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Analysis/malloc.c?rev=290415&r1=290414&r2=290415&view=diff
==============================================================================
--- cfe/trunk/test/Analysis/malloc.c (original)
+++ cfe/trunk/test/Analysis/malloc.c Thu Dec 22 22:09:18 2016
@@ -1763,17 +1763,6 @@ void testConstEscapeThroughAnotherField(
   constEscape(&(s.x)); // could free s->p!
 } // no-warning
 
-// PR15623
-int testNoCheckerDataPropogationFromLogicalOpOperandToOpResult(void) {
-   char *param = malloc(10);
-   char *value = malloc(10);
-   int ok = (param && value);
-   free(param);
-   free(value);
-   // Previously we ended up with 'Use of memory after it is freed' on return.
-   return ok; // no warning
-}
-
 // ----------------------------------------------------------------------------
 // False negatives.
 

Modified: cfe/trunk/test/Analysis/misc-ps.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Analysis/misc-ps.c?rev=290415&r1=290414&r2=290415&view=diff
==============================================================================
--- cfe/trunk/test/Analysis/misc-ps.c (original)
+++ cfe/trunk/test/Analysis/misc-ps.c Thu Dec 22 22:09:18 2016
@@ -191,13 +191,3 @@ static void PR16131(int x) {
   clang_analyzer_eval(*ip == 42); // expected-warning{{TRUE}}
   clang_analyzer_eval(*(int *)&v == 42); // expected-warning{{TRUE}}
 }
-
-// PR15623: Currently the analyzer doesn't handle symbolic expressions of the
-// form "(exp comparison_op expr) != 0" very well. We perform a simplification
-// translating an assume of a constraint of the form "(exp comparison_op expr)
-// != 0" to true into an assume of "exp comparison_op expr" to true.
-void PR15623(int n) {
-  if ((n == 0) != 0) {
-    clang_analyzer_eval(n == 0); // expected-warning{{TRUE}}
-  }
-}