[analyzer] Re-apply r283093 "Add extra notes to ObjCDeallocChecker"

The parent commit (r283092) was reverted before and now finally landed.

llvm-svn: 283660

1 files changed, 29 insertions, 3 deletions

diff --git a/clang/lib/StaticAnalyzer/Checkers/CheckObjCDealloc.cpp b/clang/lib/StaticAnalyzer/Checkers/CheckObjCDealloc.cpp
index ffb0adc8d63..8fd36b82866 100644
--- a/clang/lib/StaticAnalyzer/Checkers/CheckObjCDealloc.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/CheckObjCDealloc.cpp
@@ -107,6 +107,9 @@ class ObjCDeallocChecker
   std::unique_ptr<BugType> ExtraReleaseBugType;
   std::unique_ptr<BugType> MistakenDeallocBugType;
 
+  static constexpr const char *MsgDeclared = "Property is declared here";
+  static constexpr const char *MsgSynthesized = "Property is synthesized here";
+
 public:
   ObjCDeallocChecker();
 
@@ -128,6 +131,9 @@ public:
   void checkEndFunction(CheckerContext &Ctx) const;
 
 private:
+  void addNoteForDecl(std::unique_ptr<BugReport> &BR, StringRef Msg,
+                           const Decl *D) const;
+
   void diagnoseMissingReleases(CheckerContext &C) const;
 
   bool diagnoseExtraRelease(SymbolRef ReleasedValue, const ObjCMethodCall &M,
@@ -489,6 +495,18 @@ ProgramStateRef ObjCDeallocChecker::checkPointerEscape(
   return State;
 }
 
+/// Add an extra note piece describing a declaration that is important
+/// for understanding the bug report.
+void ObjCDeallocChecker::addNoteForDecl(std::unique_ptr<BugReport> &BR,
+                                             StringRef Msg,
+                                             const Decl *D) const {
+  ASTContext &ACtx = D->getASTContext();
+  SourceManager &SM = ACtx.getSourceManager();
+  PathDiagnosticLocation Pos = PathDiagnosticLocation::createBegin(D, SM);
+  if (Pos.isValid() && Pos.asLocation().isValid())
+    BR->addNote(Msg, Pos, D->getSourceRange());
+}
+
 /// Report any unreleased instance variables for the current instance being
 /// dealloced.
 void ObjCDeallocChecker::diagnoseMissingReleases(CheckerContext &C) const {
@@ -586,6 +604,9 @@ void ObjCDeallocChecker::diagnoseMissingReleases(CheckerContext &C) const {
     std::unique_ptr<BugReport> BR(
         new BugReport(*MissingReleaseBugType, OS.str(), ErrNode));
 
+    addNoteForDecl(BR, MsgDeclared, PropDecl);
+    addNoteForDecl(BR, MsgSynthesized, PropImpl);
+
     C.emitReport(std::move(BR));
   }
 
@@ -689,11 +710,12 @@ bool ObjCDeallocChecker::diagnoseExtraRelease(SymbolRef ReleasedValue,
          );
 
   const ObjCImplDecl *Container = getContainingObjCImpl(C.getLocationContext());
-  OS << "The '" << *PropImpl->getPropertyIvarDecl()
-     << "' ivar in '" << *Container;
+  const ObjCIvarDecl *IvarDecl = PropImpl->getPropertyIvarDecl();
+  OS << "The '" << *IvarDecl << "' ivar in '" << *Container;
 
+  bool ReleasedByCIFilterDealloc = isReleasedByCIFilterDealloc(PropImpl);
 
-  if (isReleasedByCIFilterDealloc(PropImpl)) {
+  if (ReleasedByCIFilterDealloc) {
     OS << "' will be released by '-[CIFilter dealloc]' but also released here";
   } else {
     OS << "' was synthesized for ";
@@ -710,6 +732,10 @@ bool ObjCDeallocChecker::diagnoseExtraRelease(SymbolRef ReleasedValue,
       new BugReport(*ExtraReleaseBugType, OS.str(), ErrNode));
   BR->addRange(M.getOriginExpr()->getSourceRange());
 
+  addNoteForDecl(BR, MsgDeclared, PropDecl);
+  if (!ReleasedByCIFilterDealloc)
+    addNoteForDecl(BR, MsgSynthesized, PropImpl);
+
   C.emitReport(std::move(BR));
 
   return true;