[PATCH] D66267: [analyzer] TrackConstraintBRVisitor: Do not track unknown values

[Csaba Dabis via Phabricator via cfe-commits]

Charusso created this revision.
Charusso added a reviewer: NoQ.
Charusso added a project: clang.
Herald added subscribers: cfe-commits, dkrupp, donat.nagy, Szelethus, mikhail.ramalho, a.sidorin, szepet, baloghadamsoftware, xazax.hun.
Charusso added a parent revision: D65889: [analyzer] CastValueChecker: Model castAs(), getAs().

-


Repository:
  rC Clang

https://reviews.llvm.org/D66267

Files:
  clang/lib/StaticAnalyzer/Core/BugReporterVisitors.cpp
  clang/test/Analysis/cast-value.cpp


Index: clang/test/Analysis/cast-value.cpp
===================================================================
--- clang/test/Analysis/cast-value.cpp
+++ clang/test/Analysis/cast-value.cpp
@@ -152,8 +152,7 @@
 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 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 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 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}}
Index: clang/lib/StaticAnalyzer/Core/BugReporterVisitors.cpp
===================================================================
--- clang/lib/StaticAnalyzer/Core/BugReporterVisitors.cpp
+++ clang/lib/StaticAnalyzer/Core/BugReporterVisitors.cpp
@@ -1895,9 +1895,10 @@
       report.markInteresting(V);
       report.addVisitor(llvm::make_unique<UndefOrNullArgVisitor>(R));
 
-      // If the contents are symbolic, find out when they became null.
-      if (V.getAsLocSymbol(/*IncludeBaseRegions*/ true))
-        report.addVisitor(llvm::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(llvm::make_unique<TrackConstraintBRVisitor>(
               V.castAs<DefinedSVal>(), false));
 
       // Add visitor, which will suppress inline defensive checks.


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D66267.215294.patch
Type: text/x-patch
Size: 2864 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20190815/dfcacc4e/attachment-0001.bin>