r369604 - [analyzer] TrackConstraintBRVisitor: Do not track unknown values

[Csaba Dabis via cfe-commits]

Author: charusso
Date: Wed Aug 21 17:06:58 2019
New Revision: 369604

URL: http://llvm.org/viewvc/llvm-project?rev=369604&view=rev
Log:
[analyzer] TrackConstraintBRVisitor: Do not track unknown values

Summary: -

Reviewers: NoQ, Szelethus

Reviewed By: NoQ, Szelethus

Differential Revision: https://reviews.llvm.org/D66267

Modified:
    cfe/trunk/lib/StaticAnalyzer/Core/BugReporterVisitors.cpp
    cfe/trunk/test/Analysis/cast-value.cpp

Modified: cfe/trunk/lib/StaticAnalyzer/Core/BugReporterVisitors.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/StaticAnalyzer/Core/BugReporterVisitors.cpp?rev=369604&r1=369603&r2=369604&view=diff
==============================================================================
--- cfe/trunk/lib/StaticAnalyzer/Core/BugReporterVisitors.cpp (original)
+++ cfe/trunk/lib/StaticAnalyzer/Core/BugReporterVisitors.cpp Wed Aug 21 17:06:58 2019
@@ -1992,9 +1992,10 @@ bool bugreporter::trackExpressionValue(c
       report.markInteresting(V, TKind);
       report.addVisitor(std::make_unique<UndefOrNullArgVisitor>(R));
 
-      // If the contents are symbolic, find out when they became null.
-      if (V.getAsLocSymbol(/*IncludeBaseRegions*/ true))
-        report.addVisitor(std::make_unique<TrackConstraintBRVisitor>(
+      // If the contents are symbolic and null, find out when they became null.
+      if (V.getAsLocSymbol(/*IncludeBaseRegions=*/true))
+        if (LVState->isNull(V).isConstrainedTrue())
+          report.addVisitor(std::make_unique<TrackConstraintBRVisitor>(
               V.castAs<DefinedSVal>(), false));
 
       // Add visitor, which will suppress inline defensive checks.

Modified: cfe/trunk/test/Analysis/cast-value.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Analysis/cast-value.cpp?rev=369604&r1=369603&r2=369604&view=diff
==============================================================================
--- cfe/trunk/test/Analysis/cast-value.cpp (original)
+++ cfe/trunk/test/Analysis/cast-value.cpp Wed Aug 21 17:06:58 2019
@@ -152,8 +152,7 @@ void evalReferences(const Shape &S) {
 void evalNonNullParamNonNullReturnReference(const Shape &S) {
   const auto *C = dyn_cast_or_null<Circle>(S);
   // expected-note at -1 {{Assuming dynamic cast from 'Shape' to 'Circle' succeeds}}
-  // expected-note at -2 {{Assuming pointer value is null}}
-  // expected-note at -3 {{'C' initialized here}}
+  // expected-note at -2 {{'C' initialized here}}
 
   (void)(1 / !(bool)C);
   // expected-note at -1 {{'C' is non-null}}
@@ -165,8 +164,7 @@ void evalNonNullParamNonNullReturnRefere
 void evalNonNullParamNonNullReturn(const Shape *S) {
   const auto *C = cast<Circle>(S);
   // expected-note at -1 {{Checked cast from 'Shape' to 'Circle' succeeds}}
-  // expected-note at -2 {{Assuming pointer value is null}}
-  // expected-note at -3 {{'C' initialized here}}
+  // expected-note at -2 {{'C' initialized here}}
 
   (void)(1 / !(bool)C);
   // expected-note at -1 {{'C' is non-null}}
@@ -178,7 +176,6 @@ void evalNonNullParamNonNullReturn(const
 void evalNonNullParamNullReturn(const Shape *S) {
   const auto *C = dyn_cast_or_null<Circle>(S);
   // expected-note at -1 {{Assuming dynamic cast from 'Shape' to 'Circle' fails}}
-  // expected-note at -2 {{Assuming pointer value is null}}
 
   if (const auto *T = dyn_cast_or_null<Triangle>(S)) {
     // expected-note at -1 {{Assuming dynamic cast from 'Shape' to 'Triangle' succeeds}}
@@ -207,9 +204,8 @@ void evalNullParamNullReturn(const Shape
 
 void evalZeroParamNonNullReturnPointer(const Shape *S) {
   const auto *C = S->castAs<Circle>();
-  // expected-note at -1 {{Assuming pointer value is null}}
-  // expected-note at -2 {{Checked cast to 'Circle' succeeds}}
-  // expected-note at -3 {{'C' initialized here}}
+  // expected-note at -1 {{Checked cast to 'Circle' succeeds}}
+  // expected-note at -2 {{'C' initialized here}}
 
   (void)(1 / !(bool)C);
   // expected-note at -1 {{'C' is non-null}}