Have divide-by-zero checker not handled undefined denominators. This is handled by the generic checking for undefined operands for BinaryOperators.

llvm-svn: 82019

3 files changed, 22 insertions, 30 deletions

diff --git a/clang/lib/Analysis/GRExprEngineInternalChecks.cpp b/clang/lib/Analysis/GRExprEngineInternalChecks.cpp
index 21f14652047..2eb5589117f 100644
--- a/clang/lib/Analysis/GRExprEngineInternalChecks.cpp
+++ b/clang/lib/Analysis/GRExprEngineInternalChecks.cpp
@@ -194,8 +194,7 @@ public:
 class VISIBILITY_HIDDEN DivZero : public BuiltinBug {
 public:
   DivZero(GRExprEngine* eng = 0)
-    : BuiltinBug(eng,"Division-by-zero",
-                 "Division by zero or undefined value.") {}
+    : BuiltinBug(eng,"Division by zero") {}
 
   void registerInitialVisitors(BugReporterContext& BRC,
                                const ExplodedNode* N,
@@ -222,24 +221,26 @@ public:
         llvm::SmallString<256> sbuf;
         llvm::raw_svector_ostream OS(sbuf);
         const GRState *ST = N->getState();
-        const Expr *Ex = NULL; 
+        const Expr *Ex = NULL;
+        bool isLeft = true;
 
         if (ST->getSVal(B->getLHS()).isUndef()) {
           Ex = B->getLHS()->IgnoreParenCasts();
-          OS << "The left operand of the '";
+          isLeft = true;
         }
         else if (ST->getSVal(B->getRHS()).isUndef()) {
           Ex = B->getRHS()->IgnoreParenCasts();
-          OS << "The right operand of the '";
+          isLeft = false;
         }
-      
-        if (Ex) {                  
-          OS << BinaryOperator::getOpcodeStr(B->getOpcode())
-             << "' expression is an undefined "
-                "or otherwise garbage value";
+                
+        if (Ex) {
+          OS << "The " << (isLeft ? "left" : "right")
+             << " operand of the '"
+             << BinaryOperator::getOpcodeStr(B->getOpcode())
+             << "' expression is a garbage value";
         }          
         else {
-          // We KNOW that the result was undefined.
+          // Neither operand was undefined, but the result is undefined.
           OS << "The result of the '"
              << BinaryOperator::getOpcodeStr(B->getOpcode())
              << "' expression is undefined";
@@ -268,8 +269,10 @@ public:
     
     if (const BinaryOperator *B = dyn_cast<BinaryOperator>(S)) {
       const GRState *ST = N->getState();
-      X = ST->getSVal(B->getLHS()).isUndef()
-          ? B->getLHS()->IgnoreParenCasts() : B->getRHS()->IgnoreParenCasts();
+      if (ST->getSVal(B->getLHS()).isUndef())
+        X = B->getLHS();
+      else if (ST->getSVal(B->getRHS()).isUndef())
+        X = B->getRHS();
     }
     
     registerTrackNullOrUndefValue(BRC, X, N);
@@ -766,22 +769,11 @@ void CheckBadDiv::PreVisitBinaryOperator(CheckerContext &C,
       !B->getRHS()->getType()->isScalarType())
     return;
 
-  // Check for divide by undefined.
   SVal Denom = C.getState()->getSVal(B->getRHS());
-
-  if (Denom.isUndef()) {
-    if (ExplodedNode *N = C.GenerateNode(B, true)) {
-      if (!BT)
-        BT = new DivZero();
-
-      C.EmitReport(new BuiltinBugReport(*BT, BT->getDescription().c_str(), N));
-    }
-    return;
-  }
-
-  // Handle the case where 'Denom' is UnknownVal.
   const DefinedSVal *DV = dyn_cast<DefinedSVal>(&Denom);
 
+  // Divide-by-undefined handled in the generic checking for uses of
+  // undefined values.
   if (!DV)
     return;
 
diff --git a/clang/test/Analysis/uninit-vals-ps-region.c b/clang/test/Analysis/uninit-vals-ps-region.c
index d16200743c4..716b7c920fa 100644
--- a/clang/test/Analysis/uninit-vals-ps-region.c
+++ b/clang/test/Analysis/uninit-vals-ps-region.c
@@ -25,7 +25,7 @@ void test_uninit_pos() {
   struct TestUninit v2 = test_uninit_aux();
   int z;
   v1.y = z;
-  test_unit_aux2(v2.x + v1.y);  // expected-warning{{The right operand of the '+' expression is an undefined or otherwise garbage value}}
+  test_unit_aux2(v2.x + v1.y);  // expected-warning{{The right operand of the '+' expression is a garbage value}}
 }
 void test_uninit_neg() {
   struct TestUninit v1 = { 0, 0 };
diff --git a/clang/test/Analysis/uninit-vals-ps.c b/clang/test/Analysis/uninit-vals-ps.c
index ac0e7b2f327..32b4324a7da 100644
--- a/clang/test/Analysis/uninit-vals-ps.c
+++ b/clang/test/Analysis/uninit-vals-ps.c
@@ -22,7 +22,7 @@ int f2() {
   
   int x;
   
-  if (x+1)  // expected-warning{{The left operand of the '+' expression is an undefined or otherwise garbage value}}
+  if (x+1)  // expected-warning{{The left operand of the '+' expression is a garbage value}}
     return 1;
     
   return 2;  
@@ -31,13 +31,13 @@ int f2() {
 int f2_b() {
   int x;
   
-  return ((1+x)+2+((x))) + 1 ? 1 : 2; // expected-warning{{The right operand of the '+' expression is an undefined or otherwise garbage value}}
+  return ((1+x)+2+((x))) + 1 ? 1 : 2; // expected-warning{{The right operand of the '+' expression is a garbage value}}
 }
 
 int f3(void) {
   int i;
   int *p = &i;
-  if (*p > 0) // expected-warning{{The left operand of the '>' expression is an undefined or otherwise garbage value}}
+  if (*p > 0) // expected-warning{{The left operand of the '>' expression is a garbage value}}
     return 0;
   else
     return 1;