Reapply "[analyzer] Introduce a simplified API for adding custom path notes."

This reapplies commit r357323, fixing memory leak found by LSan.

Differential Revision: https://reviews.llvm.org/D58367


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@358781 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 53 insertions, 0 deletions

diff --git a/include/clang/StaticAnalyzer/Core/BugReporter/BugReporter.h b/include/clang/StaticAnalyzer/Core/BugReporter/BugReporter.h
index a53efbbb99..46b15d0c6f 100644
--- a/include/clang/StaticAnalyzer/Core/BugReporter/BugReporter.h
+++ b/include/clang/StaticAnalyzer/Core/BugReporter/BugReporter.h
@@ -592,6 +592,59 @@ public:
   NodeMapClosure& getNodeResolver() { return NMC; }
 };
 
+
+/// The tag upon which the TagVisitor reacts. Add these in order to display
+/// additional PathDiagnosticEventPieces along the path.
+class NoteTag : public ProgramPointTag {
+public:
+  using Callback =
+      std::function<std::string(BugReporterContext &, BugReport &)>;
+
+private:
+  static int Kind;
+
+  const Callback Cb;
+
+  NoteTag(Callback &&Cb) : ProgramPointTag(&Kind), Cb(std::move(Cb)) {}
+
+public:
+  static bool classof(const ProgramPointTag *T) {
+    return T->getTagKind() == &Kind;
+  }
+
+  Optional<std::string> generateMessage(BugReporterContext &BRC,
+                                        BugReport &R) const {
+    std::string Msg = Cb(BRC, R);
+    if (Msg.empty())
+      return None;
+
+    return std::move(Msg);
+  }
+
+  StringRef getTagDescription() const override {
+    // TODO: Remember a few examples of generated messages
+    // and display them in the ExplodedGraph dump by
+    // returning them from this function.
+    return "Note Tag";
+  }
+
+  // Manage memory for NoteTag objects.
+  class Factory {
+    std::vector<std::unique_ptr<NoteTag>> Tags;
+
+  public:
+    const NoteTag *makeNoteTag(Callback &&Cb) {
+      // We cannot use make_unique because we cannot access the private
+      // constructor from inside it.
+      std::unique_ptr<NoteTag> T(new NoteTag(std::move(Cb)));
+      Tags.push_back(std::move(T));
+      return Tags.back().get();
+    }
+  };
+
+  friend class TagVisitor;
+};
+
 } // namespace ento
 
 } // namespace clang