From f258ba2e2403ada7c5c72fb9950637ddea86a014 Mon Sep 17 00:00:00 2001
From: "willchan@chromium.org"
 <willchan@chromium.org@0039d316-1c4b-4281-b951-d872f2087c98>
Date: Wed, 15 Dec 2010 09:31:33 +0000
Subject: Revert 69243 - Reland 69237 - Fix
 raw_scoped_refptr_mismatch_checker.h.

Damn, missed a unittest.

BUG=28083
TEST=none

Review URL: http://codereview.chromium.org/3549010

TBR=willchan@chromium.org
Review URL: http://codereview.chromium.org/5885001

TBR=phajdan.jr@chromium.org
Review URL: http://codereview.chromium.org/5887001

TBR=willchan@chromium.org
Review URL: http://codereview.chromium.org/5888001

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@69244 0039d316-1c4b-4281-b951-d872f2087c98
---
 base/callback.h                           |   5 +-
 base/raw_scoped_refptr_mismatch_checker.h | 225 ++++++++++++++++++------------
 base/task.h                               |  15 +-
 base/template_util.h                      |  47 -------
 4 files changed, 141 insertions(+), 151 deletions(-)

diff --git a/base/callback.h b/base/callback.h
index e5ea771..7f2eb70 100644
--- a/base/callback.h
+++ b/base/callback.h
@@ -206,9 +206,8 @@ template <class T, class Method, class Params>
 class UnboundMethod {
  public:
   UnboundMethod(Method m, const Params& p) : m_(m), p_(p) {
-    COMPILE_ASSERT(
-        (base::internal::ParamsUseScopedRefptrCorrectly<Params>::value),
-        badunboundmethodparams);
+    COMPILE_ASSERT((MethodUsesScopedRefptrCorrectly<Method, Params>::value),
+                   badunboundmethodparams);
   }
   void Run(T* obj) const {
     DispatchToMethod(obj, m_, p_);
diff --git a/base/raw_scoped_refptr_mismatch_checker.h b/base/raw_scoped_refptr_mismatch_checker.h
index b79cfb5..d2913e7 100644
--- a/base/raw_scoped_refptr_mismatch_checker.h
+++ b/base/raw_scoped_refptr_mismatch_checker.h
@@ -7,124 +7,165 @@
 #pragma once
 
 #include "base/ref_counted.h"
-#include "base/template_util.h"
 #include "base/tuple.h"
-#include "build/build_config.h"
 
-// It is dangerous to post a task with a T* argument where T is a subtype of
-// RefCounted(Base|ThreadSafeBase), since by the time the parameter is used, the
-// object may already have been deleted since it was not held with a
-// scoped_refptr. Example: http://crbug.com/27191
+// It is dangerous to post a task with a raw pointer argument to a function
+// that expects a scoped_refptr<>.  The compiler will happily accept the
+// situation, but it will not attempt to increase the refcount until the task
+// runs.  Callers expecting the argument to be refcounted up at post time are
+// in for a nasty surprise!  Example: http://crbug.com/27191
 // The following set of traits are designed to generate a compile error
 // whenever this antipattern is attempted.
-
-namespace base {
-
-// This is a base internal implementation file used by task.h and callback.h.
-// Not for public consumption, so we wrap it in namespace internal.
-namespace internal {
-
-template <typename T>
-struct NeedsScopedRefptrButGetsRawPtr {
-#if defined(OS_WIN)
-  enum {
-    value = base::false_type::value
-  };
-#else
-  enum {
-    // Human readable translation: you needed to be a scoped_refptr if you are a
-    // raw pointer type and are convertible to a RefCounted(Base|ThreadSafeBase)
-    // type.
-    value = (is_pointer<T>::value &&
-             (is_convertible<T, subtle::RefCountedBase*>::value ||
-              is_convertible<T, subtle::RefCountedThreadSafeBase*>::value))
-  };
-#endif
-};
-
-template <typename Params>
-struct ParamsUseScopedRefptrCorrectly {
+template <class A, class B>
+struct ExpectsScopedRefptrButGetsRawPtr {
   enum { value = 0 };
 };
 
-template <>
-struct ParamsUseScopedRefptrCorrectly<Tuple0> {
+template <class A, class B>
+struct ExpectsScopedRefptrButGetsRawPtr<scoped_refptr<A>, B*> {
   enum { value = 1 };
 };
 
-template <typename A>
-struct ParamsUseScopedRefptrCorrectly<Tuple1<A> > {
-  enum { value = !NeedsScopedRefptrButGetsRawPtr<A>::value };
+template <class Function, class Params>
+struct FunctionUsesScopedRefptrCorrectly {
+  enum { value = 1 };
 };
 
-template <typename A, typename B>
-struct ParamsUseScopedRefptrCorrectly<Tuple2<A, B> > {
-  enum { value = !(NeedsScopedRefptrButGetsRawPtr<A>::value ||
-                   NeedsScopedRefptrButGetsRawPtr<B>::value) };
+template <class A1, class A2>
+struct FunctionUsesScopedRefptrCorrectly<void (*)(A1), Tuple1<A2> > {
+  enum { value = !ExpectsScopedRefptrButGetsRawPtr<A1, A2>::value };
 };
 
-template <typename A, typename B, typename C>
-struct ParamsUseScopedRefptrCorrectly<Tuple3<A, B, C> > {
-  enum { value = !(NeedsScopedRefptrButGetsRawPtr<A>::value ||
-                   NeedsScopedRefptrButGetsRawPtr<B>::value ||
-                   NeedsScopedRefptrButGetsRawPtr<C>::value) };
+template <class A1, class B1, class A2, class B2>
+struct FunctionUsesScopedRefptrCorrectly<void (*)(A1, B1), Tuple2<A2, B2> > {
+  enum { value = !(ExpectsScopedRefptrButGetsRawPtr<A1, A2>::value ||
+                   ExpectsScopedRefptrButGetsRawPtr<B1, B2>::value) };
 };
 
-template <typename A, typename B, typename C, typename D>
-struct ParamsUseScopedRefptrCorrectly<Tuple4<A, B, C, D> > {
-  enum { value = !(NeedsScopedRefptrButGetsRawPtr<A>::value ||
-                   NeedsScopedRefptrButGetsRawPtr<B>::value ||
-                   NeedsScopedRefptrButGetsRawPtr<C>::value ||
-                   NeedsScopedRefptrButGetsRawPtr<D>::value) };
+template <class A1, class B1, class C1, class A2, class B2, class C2>
+struct FunctionUsesScopedRefptrCorrectly<void (*)(A1, B1, C1),
+                                         Tuple3<A2, B2, C2> > {
+  enum { value = !(ExpectsScopedRefptrButGetsRawPtr<A1, A2>::value ||
+                   ExpectsScopedRefptrButGetsRawPtr<B1, B2>::value ||
+                   ExpectsScopedRefptrButGetsRawPtr<C1, C2>::value) };
 };
 
-template <typename A, typename B, typename C, typename D, typename E>
-struct ParamsUseScopedRefptrCorrectly<Tuple5<A, B, C, D, E> > {
-  enum { value = !(NeedsScopedRefptrButGetsRawPtr<A>::value ||
-                   NeedsScopedRefptrButGetsRawPtr<B>::value ||
-                   NeedsScopedRefptrButGetsRawPtr<C>::value ||
-                   NeedsScopedRefptrButGetsRawPtr<D>::value ||
-                   NeedsScopedRefptrButGetsRawPtr<E>::value) };
+template <class A1, class B1, class C1, class D1,
+          class A2, class B2, class C2, class D2>
+struct FunctionUsesScopedRefptrCorrectly<void (*)(A1, B1, C1, D1),
+                                         Tuple4<A2, B2, C2, D2> > {
+  enum { value = !(ExpectsScopedRefptrButGetsRawPtr<A1, A2>::value ||
+                   ExpectsScopedRefptrButGetsRawPtr<B1, B2>::value ||
+                   ExpectsScopedRefptrButGetsRawPtr<C1, C2>::value ||
+                   ExpectsScopedRefptrButGetsRawPtr<D1, D2>::value) };
 };
 
-template <typename A, typename B, typename C, typename D, typename E,
-          typename F>
-struct ParamsUseScopedRefptrCorrectly<Tuple6<A, B, C, D, E, F> > {
-  enum { value = !(NeedsScopedRefptrButGetsRawPtr<A>::value ||
-                   NeedsScopedRefptrButGetsRawPtr<B>::value ||
-                   NeedsScopedRefptrButGetsRawPtr<C>::value ||
-                   NeedsScopedRefptrButGetsRawPtr<D>::value ||
-                   NeedsScopedRefptrButGetsRawPtr<E>::value ||
-                   NeedsScopedRefptrButGetsRawPtr<F>::value) };
+template <class A1, class B1, class C1, class D1, class E1,
+          class A2, class B2, class C2, class D2, class E2>
+struct FunctionUsesScopedRefptrCorrectly<void (*)(A1, B1, C1, D1, E1),
+                                         Tuple5<A2, B2, C2, D2, E2> > {
+  enum { value = !(ExpectsScopedRefptrButGetsRawPtr<A1, A2>::value ||
+                   ExpectsScopedRefptrButGetsRawPtr<B1, B2>::value ||
+                   ExpectsScopedRefptrButGetsRawPtr<C1, C2>::value ||
+                   ExpectsScopedRefptrButGetsRawPtr<D1, D2>::value ||
+                   ExpectsScopedRefptrButGetsRawPtr<E1, E2>::value) };
 };
 
-template <typename A, typename B, typename C, typename D, typename E,
-          typename F, typename G>
-struct ParamsUseScopedRefptrCorrectly<Tuple7<A, B, C, D, E, F, G> > {
-  enum { value = !(NeedsScopedRefptrButGetsRawPtr<A>::value ||
-                   NeedsScopedRefptrButGetsRawPtr<B>::value ||
-                   NeedsScopedRefptrButGetsRawPtr<C>::value ||
-                   NeedsScopedRefptrButGetsRawPtr<D>::value ||
-                   NeedsScopedRefptrButGetsRawPtr<E>::value ||
-                   NeedsScopedRefptrButGetsRawPtr<F>::value ||
-                   NeedsScopedRefptrButGetsRawPtr<G>::value) };
+template <class A1, class B1, class C1, class D1, class E1, class F1,
+          class A2, class B2, class C2, class D2, class E2, class F2>
+struct FunctionUsesScopedRefptrCorrectly<void (*)(A1, B1, C1, D1, E1, F1),
+                                         Tuple6<A2, B2, C2, D2, E2, F2> > {
+  enum { value = !(ExpectsScopedRefptrButGetsRawPtr<A1, A2>::value ||
+                   ExpectsScopedRefptrButGetsRawPtr<B1, B2>::value ||
+                   ExpectsScopedRefptrButGetsRawPtr<C1, C2>::value ||
+                   ExpectsScopedRefptrButGetsRawPtr<D1, D2>::value ||
+                   ExpectsScopedRefptrButGetsRawPtr<E1, E2>::value ||
+                   ExpectsScopedRefptrButGetsRawPtr<F1, F2>::value) };
 };
 
-template <typename A, typename B, typename C, typename D, typename E,
-          typename F, typename G, typename H>
-struct ParamsUseScopedRefptrCorrectly<Tuple8<A, B, C, D, E, F, G, H> > {
-  enum { value = !(NeedsScopedRefptrButGetsRawPtr<A>::value ||
-                   NeedsScopedRefptrButGetsRawPtr<B>::value ||
-                   NeedsScopedRefptrButGetsRawPtr<C>::value ||
-                   NeedsScopedRefptrButGetsRawPtr<D>::value ||
-                   NeedsScopedRefptrButGetsRawPtr<E>::value ||
-                   NeedsScopedRefptrButGetsRawPtr<F>::value ||
-                   NeedsScopedRefptrButGetsRawPtr<G>::value ||
-                   NeedsScopedRefptrButGetsRawPtr<H>::value) };
+template <class A1, class B1, class C1, class D1, class E1, class F1, class G1,
+          class A2, class B2, class C2, class D2, class E2, class F2, class G2>
+struct FunctionUsesScopedRefptrCorrectly<void (*)(A1, B1, C1, D1, E1, F1, G1),
+                                         Tuple7<A2, B2, C2, D2, E2, F2, G2> > {
+  enum { value = !(ExpectsScopedRefptrButGetsRawPtr<A1, A2>::value ||
+                   ExpectsScopedRefptrButGetsRawPtr<B1, B2>::value ||
+                   ExpectsScopedRefptrButGetsRawPtr<C1, C2>::value ||
+                   ExpectsScopedRefptrButGetsRawPtr<D1, D2>::value ||
+                   ExpectsScopedRefptrButGetsRawPtr<E1, E2>::value ||
+                   ExpectsScopedRefptrButGetsRawPtr<F1, F2>::value ||
+                   ExpectsScopedRefptrButGetsRawPtr<G1, G2>::value) };
 };
 
-}  // namespace internal
+template <class Method, class Params>
+struct MethodUsesScopedRefptrCorrectly {
+  enum { value = 1 };
+};
 
-}  // namespace base
+template <class T, class A1, class A2>
+struct MethodUsesScopedRefptrCorrectly<void (T::*)(A1), Tuple1<A2> > {
+  enum { value = !ExpectsScopedRefptrButGetsRawPtr<A1, A2>::value };
+};
+
+template <class T, class A1, class B1, class A2, class B2>
+struct MethodUsesScopedRefptrCorrectly<void (T::*)(A1, B1), Tuple2<A2, B2> > {
+  enum { value = !(ExpectsScopedRefptrButGetsRawPtr<A1, A2>::value ||
+                   ExpectsScopedRefptrButGetsRawPtr<B1, B2>::value) };
+};
+
+template <class T, class A1, class B1, class C1,
+                   class A2, class B2, class C2>
+struct MethodUsesScopedRefptrCorrectly<void (T::*)(A1, B1, C1),
+                                       Tuple3<A2, B2, C2> > {
+  enum { value = !(ExpectsScopedRefptrButGetsRawPtr<A1, A2>::value ||
+                   ExpectsScopedRefptrButGetsRawPtr<B1, B2>::value ||
+                   ExpectsScopedRefptrButGetsRawPtr<C1, C2>::value) };
+};
+
+template <class T, class A1, class B1, class C1, class D1,
+          class A2, class B2, class C2, class D2>
+struct MethodUsesScopedRefptrCorrectly<void (T::*)(A1, B1, C1, D1),
+                                       Tuple4<A2, B2, C2, D2> > {
+  enum { value = !(ExpectsScopedRefptrButGetsRawPtr<A1, A2>::value ||
+                   ExpectsScopedRefptrButGetsRawPtr<B1, B2>::value ||
+                   ExpectsScopedRefptrButGetsRawPtr<C1, C2>::value ||
+                   ExpectsScopedRefptrButGetsRawPtr<D1, D2>::value) };
+};
+
+template <class T, class A1, class B1, class C1, class D1, class E1,
+                   class A2, class B2, class C2, class D2, class E2>
+struct MethodUsesScopedRefptrCorrectly<void (T::*)(A1, B1, C1, D1, E1),
+                                       Tuple5<A2, B2, C2, D2, E2> > {
+  enum { value = !(ExpectsScopedRefptrButGetsRawPtr<A1, A2>::value ||
+                   ExpectsScopedRefptrButGetsRawPtr<B1, B2>::value ||
+                   ExpectsScopedRefptrButGetsRawPtr<C1, C2>::value ||
+                   ExpectsScopedRefptrButGetsRawPtr<D1, D2>::value ||
+                   ExpectsScopedRefptrButGetsRawPtr<E1, E2>::value) };
+};
+
+template <class T, class A1, class B1, class C1, class D1, class E1, class F1,
+                   class A2, class B2, class C2, class D2, class E2, class F2>
+struct MethodUsesScopedRefptrCorrectly<void (T::*)(A1, B1, C1, D1, E1, F1),
+                                       Tuple6<A2, B2, C2, D2, E2, F2> > {
+  enum { value = !(ExpectsScopedRefptrButGetsRawPtr<A1, A2>::value ||
+                   ExpectsScopedRefptrButGetsRawPtr<B1, B2>::value ||
+                   ExpectsScopedRefptrButGetsRawPtr<C1, C2>::value ||
+                   ExpectsScopedRefptrButGetsRawPtr<D1, D2>::value ||
+                   ExpectsScopedRefptrButGetsRawPtr<E1, E2>::value ||
+                   ExpectsScopedRefptrButGetsRawPtr<F1, F2>::value) };
+};
+
+template <class T,
+          class A1, class B1, class C1, class D1, class E1, class F1, class G1,
+          class A2, class B2, class C2, class D2, class E2, class F2, class G2>
+struct MethodUsesScopedRefptrCorrectly<void (T::*)(A1, B1, C1, D1, E1, F1, G1),
+                                       Tuple7<A2, B2, C2, D2, E2, F2, G2> > {
+  enum { value = !(ExpectsScopedRefptrButGetsRawPtr<A1, A2>::value ||
+                   ExpectsScopedRefptrButGetsRawPtr<B1, B2>::value ||
+                   ExpectsScopedRefptrButGetsRawPtr<C1, C2>::value ||
+                   ExpectsScopedRefptrButGetsRawPtr<D1, D2>::value ||
+                   ExpectsScopedRefptrButGetsRawPtr<E1, E2>::value ||
+                   ExpectsScopedRefptrButGetsRawPtr<F1, F2>::value ||
+                   ExpectsScopedRefptrButGetsRawPtr<G1, G2>::value) };
+};
 
 #endif  // BASE_RAW_SCOPED_REFPTR_MISMATCH_CHECKER_H_
diff --git a/base/task.h b/base/task.h
index 1949e74..b21ccd8 100644
--- a/base/task.h
+++ b/base/task.h
@@ -149,9 +149,8 @@ class ScopedRunnableMethodFactory {
         : obj_(obj),
           meth_(meth),
           params_(params) {
-      COMPILE_ASSERT(
-          (base::internal::ParamsUseScopedRefptrCorrectly<Params>::value),
-          badscopedrunnablemethodparams);
+      COMPILE_ASSERT((MethodUsesScopedRefptrCorrectly<Method, Params>::value),
+                     badscopedrunnablemethodparams);
     }
 
     virtual void Run() {
@@ -318,9 +317,8 @@ class RunnableMethod : public CancelableTask {
   RunnableMethod(T* obj, Method meth, const Params& params)
       : obj_(obj), meth_(meth), params_(params) {
     traits_.RetainCallee(obj_);
-    COMPILE_ASSERT(
-        (base::internal::ParamsUseScopedRefptrCorrectly<Params>::value),
-        badrunnablemethodparams);
+    COMPILE_ASSERT((MethodUsesScopedRefptrCorrectly<Method, Params>::value),
+                   badrunnablemethodparams);
   }
 
   ~RunnableMethod() {
@@ -431,9 +429,8 @@ class RunnableFunction : public CancelableTask {
  public:
   RunnableFunction(Function function, const Params& params)
       : function_(function), params_(params) {
-    COMPILE_ASSERT(
-        (base::internal::ParamsUseScopedRefptrCorrectly<Params>::value),
-        badrunnablefunctionparams);
+    COMPILE_ASSERT((FunctionUsesScopedRefptrCorrectly<Function, Params>::value),
+                   badrunnablefunctionparams);
   }
 
   ~RunnableFunction() {
diff --git a/base/template_util.h b/base/template_util.h
index 27bdb73..2cfe04c 100644
--- a/base/template_util.h
+++ b/base/template_util.h
@@ -6,8 +6,6 @@
 #define BASE_TEMPLATE_UTIL_H_
 #pragma once
 
-#include "build/build_config.h"
-
 namespace base {
 
 // template definitions from tr1
@@ -27,51 +25,6 @@ typedef integral_constant<bool, false> false_type;
 template <class T> struct is_pointer : false_type {};
 template <class T> struct is_pointer<T*> : true_type {};
 
-namespace internal {
-
-// Types small_ and big_ are guaranteed such that sizeof(small_) <
-// sizeof(big_)
-typedef char small_;
-
-struct big_ {
-  small_ dummy[2];
-};
-
-#if !defined(OS_WIN)
-
-// This class is an implementation detail for is_convertible, and you
-// don't need to know how it works to use is_convertible. For those
-// who care: we declare two different functions, one whose argument is
-// of type To and one with a variadic argument list. We give them
-// return types of different size, so we can use sizeof to trick the
-// compiler into telling us which function it would have chosen if we
-// had called it with an argument of type From.  See Alexandrescu's
-// _Modern C++ Design_ for more details on this sort of trick.
-
-template <typename From, typename To>
-struct ConvertHelper {
-  static small_ Test(To);
-  static big_ Test(...);
-  static From Create();
-};
-
-#endif  // !defined(OS_WIN)
-
-}  // namespace internal
-
-#if !defined(OS_WIN)
-
-// Inherits from true_type if From is convertible to To, false_type otherwise.
-template <typename From, typename To>
-struct is_convertible
-    : integral_constant<bool,
-                        sizeof(internal::ConvertHelper<From, To>::Test(
-                                  internal::ConvertHelper<From, To>::Create()))
-                        == sizeof(internal::small_)> {
-};
-
-#endif  // !defined(OS_WIN)
-
 }  // namespace base
 
 #endif  // BASE_TEMPLATE_UTIL_H_
-- 
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