[analyzer] [RetainCountChecker] Track input parameters to the top-level function

Track them for ISL/OS objects by default, and for NS/CF under a flag.

rdar://47536377

Differential Revision: https://reviews.llvm.org/D57356

llvm-svn: 352534

1 files changed, 49 insertions, 5 deletions

diff --git a/clang/lib/StaticAnalyzer/Checkers/RetainCountChecker/RetainCountDiagnostics.cpp b/clang/lib/StaticAnalyzer/Checkers/RetainCountChecker/RetainCountDiagnostics.cpp
index dcb5ca85558..8e13ee35f3c 100644
--- a/clang/lib/StaticAnalyzer/Checkers/RetainCountChecker/RetainCountDiagnostics.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/RetainCountChecker/RetainCountDiagnostics.cpp
@@ -418,6 +418,38 @@ annotateConsumedSummaryMismatch(const ExplodedNode *N,
   return std::make_shared<PathDiagnosticEventPiece>(L, os.str());
 }
 
+/// Annotate the parameter at the analysis entry point.
+static std::shared_ptr<PathDiagnosticEventPiece>
+annotateStartParameter(const ExplodedNode *N, SymbolRef Sym,
+                       const SourceManager &SM) {
+  auto PP = N->getLocationAs<BlockEdge>();
+  if (!PP)
+    return nullptr;
+
+  const CFGBlock *Src = PP->getSrc();
+  const RefVal *CurrT = getRefBinding(N->getState(), Sym);
+
+  if (&Src->getParent()->getEntry() != Src || !CurrT ||
+      getRefBinding(N->getFirstPred()->getState(), Sym))
+    return nullptr;
+
+  const auto *VR = cast<VarRegion>(cast<SymbolRegionValue>(Sym)->getRegion());
+  const auto *PVD = cast<ParmVarDecl>(VR->getDecl());
+  PathDiagnosticLocation L = PathDiagnosticLocation(PVD, SM);
+
+  std::string s;
+  llvm::raw_string_ostream os(s);
+  os << "Parameter '" << PVD->getNameAsString()
+    << "' starts at +";
+  if (CurrT->getCount() == 1) {
+    os << "1, as it is marked as consuming";
+  } else {
+    assert(CurrT->getCount() == 0);
+    os << "0";
+  }
+  return std::make_shared<PathDiagnosticEventPiece>(L, os.str());
+}
+
 std::shared_ptr<PathDiagnosticPiece>
 RefCountReportVisitor::VisitNode(const ExplodedNode *N,
                               BugReporterContext &BRC, BugReport &BR) {
@@ -435,6 +467,9 @@ RefCountReportVisitor::VisitNode(const ExplodedNode *N,
     if (auto PD = annotateConsumedSummaryMismatch(N, *CE, SM, CEMgr))
       return PD;
 
+  if (auto PD = annotateStartParameter(N, Sym, SM))
+    return PD;
+
   // FIXME: We will eventually need to handle non-statement-based events
   // (__attribute__((cleanup))).
   if (!N->getLocation().getAs<StmtPoint>())
@@ -673,7 +708,7 @@ static AllocationInfo GetAllocationSite(ProgramStateManager &StateMgr,
 
   if (AllocationNodeInCurrentOrParentContext &&
       AllocationNodeInCurrentOrParentContext->getLocationContext() !=
-          LeakContext)
+      LeakContext)
     FirstBinding = nullptr;
 
   return AllocationInfo(AllocationNodeInCurrentOrParentContext,
@@ -757,10 +792,19 @@ RefLeakReportVisitor::getEndPath(BugReporterContext &BRC,
         }
       } else {
         const FunctionDecl *FD = cast<FunctionDecl>(D);
-        os << "whose name ('" << *FD
-           << "') does not contain 'Copy' or 'Create'.  This violates the naming"
-              " convention rules given in the Memory Management Guide for Core"
-              " Foundation";
+        ObjKind K = RV->getObjKind();
+        if (K == ObjKind::ObjC || K == ObjKind::CF) {
+          os << "whose name ('" << *FD
+             << "') does not contain 'Copy' or 'Create'.  This violates the "
+                "naming"
+                " convention rules given in the Memory Management Guide for "
+                "Core"
+                " Foundation";
+        } else if (RV->getObjKind() == ObjKind::OS) {
+          std::string FuncName = FD->getNameAsString();
+          os << "whose name ('" << FuncName
+            << "') starts with '" << StringRef(FuncName).substr(0, 3) << "'";
+        }
       }
     }
   } else {