From 9cda4ca6bff42b4afb6a63ce5f81793fcc9a04f3 Mon Sep 17 00:00:00 2001
From: Andrzej Kotulski <akotulski@fb.com>
Date: Mon, 11 Jul 2016 02:23:59 -0700
Subject: [PATCH] Add models of shared_ptr comparison operators

Reviewed By: jvillard

Differential Revision: D3534300

fbshipit-source-id: a95ecf4
---
 .../cpp/include/infer_model/shared_ptr.h      | 96 +++++++++++++++++++
 .../cpp/errors/smart_ptr/shared_ptr_deref.cpp | 20 ++++
 2 files changed, 116 insertions(+)

diff --git a/infer/models/cpp/include/infer_model/shared_ptr.h b/infer/models/cpp/include/infer_model/shared_ptr.h
index ceb7d4c9d..b26f0bbe2 100644
--- a/infer/models/cpp/include/infer_model/shared_ptr.h
+++ b/infer/models/cpp/include/infer_model/shared_ptr.h
@@ -214,6 +214,102 @@ class shared_ptr : public std__shared_ptr<T> {
     return true; /* FIXME - use non-det */
   }
 };
+template <class _Tp, class _Up>
+inline bool operator==(const shared_ptr<_Tp>& __x,
+                       const shared_ptr<_Up>& __y) noexcept {
+  return __x.get() == __y.get();
+}
+
+template <class _Tp, class _Up>
+inline bool operator!=(const shared_ptr<_Tp>& __x,
+                       const shared_ptr<_Up>& __y) noexcept {
+  return !(__x == __y);
+}
+
+template <class _Tp, class _Up>
+inline bool operator<(const shared_ptr<_Tp>& __x,
+                      const shared_ptr<_Up>& __y) noexcept {
+  typedef typename common_type<_Tp*, _Up*>::type _Vp;
+  return less<_Vp>()(__x.get(), __y.get());
+}
+
+template <class _Tp, class _Up>
+inline bool operator>(const shared_ptr<_Tp>& __x,
+                      const shared_ptr<_Up>& __y) noexcept {
+  return __y < __x;
+}
+
+template <class _Tp, class _Up>
+inline bool operator<=(const shared_ptr<_Tp>& __x,
+                       const shared_ptr<_Up>& __y) noexcept {
+  return !(__y < __x);
+}
+
+template <class _Tp, class _Up>
+inline bool operator>=(const shared_ptr<_Tp>& __x,
+                       const shared_ptr<_Up>& __y) noexcept {
+  return !(__x < __y);
+}
+
+template <class _Tp>
+inline bool operator==(const shared_ptr<_Tp>& __x, nullptr_t) noexcept {
+  return !__x;
+}
+
+template <class _Tp>
+inline bool operator==(nullptr_t, const shared_ptr<_Tp>& __x) noexcept {
+  return !__x;
+}
+
+template <class _Tp>
+inline bool operator!=(const shared_ptr<_Tp>& __x, nullptr_t) noexcept {
+  return static_cast<bool>(__x);
+}
+
+template <class _Tp>
+inline bool operator!=(nullptr_t, const shared_ptr<_Tp>& __x) noexcept {
+  return static_cast<bool>(__x);
+}
+
+template <class _Tp>
+inline bool operator<(const shared_ptr<_Tp>& __x, nullptr_t) noexcept {
+  return less<_Tp*>()(__x.get(), nullptr);
+}
+
+template <class _Tp>
+inline bool operator<(nullptr_t, const shared_ptr<_Tp>& __x) noexcept {
+  return less<_Tp*>()(nullptr, __x.get());
+}
+
+template <class _Tp>
+inline bool operator>(const shared_ptr<_Tp>& __x, nullptr_t) noexcept {
+  return nullptr < __x;
+}
+
+template <class _Tp>
+inline bool operator>(nullptr_t, const shared_ptr<_Tp>& __x) noexcept {
+  return __x < nullptr;
+}
+
+template <class _Tp>
+inline bool operator<=(const shared_ptr<_Tp>& __x, nullptr_t) noexcept {
+  return !(nullptr < __x);
+}
+
+template <class _Tp>
+inline bool operator<=(nullptr_t, const shared_ptr<_Tp>& __x) noexcept {
+  return !(__x < nullptr);
+}
+
+template <class _Tp>
+inline bool operator>=(const shared_ptr<_Tp>& __x, nullptr_t) noexcept {
+  return !(__x < nullptr);
+}
+
+template <class _Tp>
+inline bool operator>=(nullptr_t, const shared_ptr<_Tp>& __x) noexcept {
+  return !(nullptr < __x);
+}
 
 template <class T>
 struct hash<shared_ptr<T>> : public hash<std__shared_ptr<T>> {};
diff --git a/infer/tests/codetoanalyze/cpp/errors/smart_ptr/shared_ptr_deref.cpp b/infer/tests/codetoanalyze/cpp/errors/smart_ptr/shared_ptr_deref.cpp
index d90122b7f..228c8a2ad 100644
--- a/infer/tests/codetoanalyze/cpp/errors/smart_ptr/shared_ptr_deref.cpp
+++ b/infer/tests/codetoanalyze/cpp/errors/smart_ptr/shared_ptr_deref.cpp
@@ -107,3 +107,23 @@ int shared_ptr_move_null_deref() {
   std::shared_ptr<int> p2 = std::move(p1);
   return *p1;
 }
+
+int shared_ptr_check_null() {
+  std::shared_ptr<int> p;
+  if (p == nullptr)
+    return 1;
+  return *p;
+}
+
+int shared_ptr_check_notnull() {
+  std::shared_ptr<int> p;
+  if (p != nullptr)
+    return *p;
+  return 1;
+}
+
+int shared_ptr_check_null2(std::shared_ptr<int> p) {
+  if (p == nullptr)
+    return 1;
+  return *p;
+}