Index: clang-tidy/modernize/CMakeLists.txt
===================================================================
--- clang-tidy/modernize/CMakeLists.txt
+++ clang-tidy/modernize/CMakeLists.txt
@@ -4,6 +4,7 @@
   AvoidBindCheck.cpp
   ConcatNestedNamespacesCheck.cpp
   DeprecatedHeadersCheck.cpp
+  DeprecatedIosBaseAliasesCheck.cpp
   LoopConvertCheck.cpp
   LoopConvertUtils.cpp
   MakeSharedCheck.cpp
Index: clang-tidy/modernize/DeprecatedIosBaseAliasesCheck.h
===================================================================
--- clang-tidy/modernize/DeprecatedIosBaseAliasesCheck.h
+++ clang-tidy/modernize/DeprecatedIosBaseAliasesCheck.h
@@ -0,0 +1,36 @@
+//===--- DeprecatedIosBaseAliasesCheck.h - clang-tidy------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MODERNIZE_DEPRECATEDIOSBASEALIASESCHECK_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MODERNIZE_DEPRECATEDIOSBASEALIASESCHECK_H
+
+#include "../ClangTidy.h"
+
+namespace clang {
+namespace tidy {
+namespace modernize {
+
+/// This check warns the uses of the deprecated member types of ``std::ios_base``
+/// and replaces those that have a non-deprecated equivalent.
+///
+/// For the user-facing documentation see:
+/// http://clang.llvm.org/extra/clang-tidy/checks/modernize-deprecated-ios-base-aliases.html
+class DeprecatedIosBaseAliasesCheck : public ClangTidyCheck {
+public:
+  DeprecatedIosBaseAliasesCheck(StringRef Name, ClangTidyContext *Context)
+      : ClangTidyCheck(Name, Context) {}
+  void registerMatchers(ast_matchers::MatchFinder *Finder) override;
+  void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+};
+
+} // namespace modernize
+} // namespace tidy
+} // namespace clang
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MODERNIZE_DEPRECATEDIOSBASEALIASESCHECK_H
Index: clang-tidy/modernize/DeprecatedIosBaseAliasesCheck.cpp
===================================================================
--- clang-tidy/modernize/DeprecatedIosBaseAliasesCheck.cpp
+++ clang-tidy/modernize/DeprecatedIosBaseAliasesCheck.cpp
@@ -0,0 +1,80 @@
+//===--- DeprecatedIosBaseAliasesCheck.cpp - clang-tidy--------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "DeprecatedIosBaseAliasesCheck.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang {
+namespace tidy {
+namespace modernize {
+
+static const std::array<StringRef, 5> DeprecatedTypes = {
+    "::std::ios_base::io_state",  "::std::ios_base::open_mode",
+    "::std::ios_base::seek_dir",  "::std::ios_base::streamoff",
+    "::std::ios_base::streampos",
+};
+
+static const llvm::StringMap<StringRef> ReplacementTypes = {
+    {"io_state", "iostate"},
+    {"open_mode", "openmode"},
+    {"seek_dir", "seekdir"}};
+
+void DeprecatedIosBaseAliasesCheck::registerMatchers(MatchFinder *Finder) {
+  // Only register the matchers for C++; the functionality currently does not
+  // provide any benefit to other languages, despite being benign.
+  if (!getLangOpts().CPlusPlus)
+    return;
+
+  auto IoStateDecl = typedefDecl(hasAnyName(DeprecatedTypes)).bind("TypeDecl");
+  auto IoStateType =
+      qualType(hasDeclaration(IoStateDecl), unless(elaboratedType()));
+
+  Finder->addMatcher(typeLoc(loc(IoStateType)).bind("TypeLoc"), this);
+}
+
+void DeprecatedIosBaseAliasesCheck::check(
+    const MatchFinder::MatchResult &Result) {
+  SourceManager &SM = *Result.SourceManager;
+
+  const auto *Typedef = Result.Nodes.getNodeAs<TypedefDecl>("TypeDecl");
+  StringRef TypeName = Typedef->getName();
+  bool HasReplacement = ReplacementTypes.count(TypeName);
+
+  const auto *TL = Result.Nodes.getNodeAs<TypeLoc>("TypeLoc");
+  SourceLocation IoStateLoc = TL->getBeginLoc();
+
+  // Do not generate fixits for matches depending on template arguments and
+  // macro expansions.
+  bool Fix = HasReplacement && !TL->getType()->isDependentType();
+  if (IoStateLoc.isMacroID()) {
+    IoStateLoc = SM.getSpellingLoc(IoStateLoc);
+    Fix = false;
+  }
+
+  SourceLocation EndLoc = IoStateLoc.getLocWithOffset(TypeName.size() - 1);
+
+  if (HasReplacement) {
+    auto FixName = ReplacementTypes.lookup(TypeName);
+    auto Builder = diag(IoStateLoc, "'std::ios_base::%0' is deprecated; use "
+                                    "'std::ios_base::%1' instead")
+                   << TypeName << FixName;
+
+    if (Fix)
+      Builder << FixItHint::CreateReplacement(SourceRange(IoStateLoc, EndLoc),
+                                              FixName);
+  } else
+    diag(IoStateLoc, "'std::ios_base::%0' is deprecated") << TypeName;
+}
+
+} // namespace modernize
+} // namespace tidy
+} // namespace clang
Index: clang-tidy/modernize/ModernizeTidyModule.cpp
===================================================================
--- clang-tidy/modernize/ModernizeTidyModule.cpp
+++ clang-tidy/modernize/ModernizeTidyModule.cpp
@@ -13,6 +13,7 @@
 #include "AvoidBindCheck.h"
 #include "ConcatNestedNamespacesCheck.h"
 #include "DeprecatedHeadersCheck.h"
+#include "DeprecatedIosBaseAliasesCheck.h"
 #include "LoopConvertCheck.h"
 #include "MakeSharedCheck.h"
 #include "MakeUniqueCheck.h"
@@ -51,6 +52,8 @@
         "modernize-concat-nested-namespaces");
     CheckFactories.registerCheck<DeprecatedHeadersCheck>(
         "modernize-deprecated-headers");
+    CheckFactories.registerCheck<DeprecatedIosBaseAliasesCheck>(
+        "modernize-deprecated-ios-base-aliases");
     CheckFactories.registerCheck<LoopConvertCheck>("modernize-loop-convert");
     CheckFactories.registerCheck<MakeSharedCheck>("modernize-make-shared");
     CheckFactories.registerCheck<MakeUniqueCheck>("modernize-make-unique");
Index: docs/ReleaseNotes.rst
===================================================================
--- docs/ReleaseNotes.rst
+++ docs/ReleaseNotes.rst
@@ -99,6 +99,12 @@
   Checks for uses of nested namespaces in the form of
   ``namespace a { namespace b { ... }}`` and offers change to
   syntax introduced in C++17 standard: ``namespace a::b { ... }``.
+  
+- New :doc:`modernize-deprecated-ios-base-aliases
+  <clang-tidy/checks/modernize-deprecated-ios-base-aliases>` check.
+
+  This check warns the uses of the deprecated member types of ``std::ios_base``
+  and replaces those that have a non-deprecated equivalent.
 
 - New :doc:`readability-magic-numbers
   <clang-tidy/checks/readability-magic-numbers>` check.
Index: docs/clang-tidy/checks/list.rst
===================================================================
--- docs/clang-tidy/checks/list.rst
+++ docs/clang-tidy/checks/list.rst
@@ -174,6 +174,7 @@
    modernize-avoid-bind
    modernize-concat-nested-namespaces
    modernize-deprecated-headers
+   modernize-deprecated-ios-base-aliases
    modernize-loop-convert
    modernize-make-shared
    modernize-make-unique
Index: docs/clang-tidy/checks/modernize-deprecated-ios-base-aliases.rst
===================================================================
--- docs/clang-tidy/checks/modernize-deprecated-ios-base-aliases.rst
+++ docs/clang-tidy/checks/modernize-deprecated-ios-base-aliases.rst
@@ -0,0 +1,17 @@
+.. title:: clang-tidy - modernize-deprecated-ios-base-aliases
+
+modernize-deprecated-ios-base-aliases
+=====================================
+
+This check warns the uses of the deprecated member types of ``std::ios_base``
+and replaces those that have a non-deprecated equivalent.
+
+===================================  ===========================
+Deprecated member type               Replacement
+===================================  ===========================
+``std::ios_base::io_state``          ``std::ios_base::iostate``
+``std::ios_base::open_mode``         ``std::ios_base::openmode``
+``std::ios_base::seek_dir``          ``std::ios_base::seekdir``
+``std::ios_base::streamoff``          
+``std::ios_base::streampos``         
+===================================  ===========================
Index: test/clang-tidy/modernize-deprecated-ios-base-aliases.cpp
===================================================================
--- test/clang-tidy/modernize-deprecated-ios-base-aliases.cpp
+++ test/clang-tidy/modernize-deprecated-ios-base-aliases.cpp
@@ -0,0 +1,239 @@
+// RUN: %check_clang_tidy %s modernize-deprecated-ios-base-aliases %t
+
+namespace std {
+class ios_base {
+public:
+  typedef int io_state;
+  typedef int open_mode;
+  typedef int seek_dir;
+
+  typedef int streampos;
+  typedef int streamoff;
+};
+
+template <class CharT>
+class basic_ios : public ios_base {
+};
+} // namespace std
+
+// Test function return values (declaration)
+std::ios_base::io_state f_5();
+// CHECK-MESSAGES: :[[@LINE-1]]:16: warning: 'std::ios_base::io_state' is deprecated; use 'std::ios_base::iostate' instead [modernize-deprecated-ios-base-aliases]
+// CHECK-FIXES: std::ios_base::iostate f_5();
+
+// Test function parameters.
+void f_6(std::ios_base::open_mode);
+// CHECK-MESSAGES: :[[@LINE-1]]:25: warning: 'std::ios_base::open_mode' is deprecated
+// CHECK-FIXES: void f_6(std::ios_base::openmode);
+void f_7(const std::ios_base::seek_dir &);
+// CHECK-MESSAGES: :[[@LINE-1]]:31: warning: 'std::ios_base::seek_dir' is deprecated
+// CHECK-FIXES: void f_7(const std::ios_base::seekdir &);
+
+// Test on record type fields.
+struct A {
+  std::ios_base::io_state field;
+  // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: 'std::ios_base::io_state' is deprecated
+  // CHECK-FIXES: std::ios_base::iostate field;
+
+  typedef std::ios_base::io_state int_ptr_type;
+  // CHECK-MESSAGES: :[[@LINE-1]]:26: warning: 'std::ios_base::io_state' is deprecated
+  // CHECK-FIXES: typedef std::ios_base::iostate int_ptr_type;
+};
+
+struct B : public std::ios_base {
+  io_state a;
+  // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: 'std::ios_base::io_state' is deprecated
+  // CHECK-FIXES: iostate a;
+};
+
+struct C : public std::basic_ios<char> {
+  io_state a;
+  // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: 'std::ios_base::io_state' is deprecated
+  // CHECK-FIXES: iostate a;
+};
+
+void f_1() {
+  std::ios_base::io_state a;
+  // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: 'std::ios_base::io_state' is deprecated
+  // CHECK-FIXES: std::ios_base::iostate a;
+
+  // Check that spaces aren't modified unnecessarily.
+  std :: ios_base :: io_state b;
+  // CHECK-MESSAGES: :[[@LINE-1]]:22: warning: 'std::ios_base::io_state' is deprecated
+  // CHECK-FIXES: std :: ios_base :: iostate b;
+
+  // Test construction from a temporary.
+  std::ios_base::io_state c = std::ios_base::io_state{};
+  // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: 'std::ios_base::io_state' is deprecated
+  // CHECK-MESSAGES: :[[@LINE-2]]:46: warning: 'std::ios_base::io_state' is deprecated
+  // CHECK-FIXES: std::ios_base::iostate c = std::ios_base::iostate{};
+
+  typedef std::ios_base::io_state alias1;
+  // CHECK-MESSAGES: :[[@LINE-1]]:26: warning: 'std::ios_base::io_state' is deprecated
+  // CHECK-FIXES: typedef std::ios_base::iostate alias1;
+  alias1 d(a);
+
+  using alias2 = std::ios_base::io_state;
+  // CHECK-MESSAGES: :[[@LINE-1]]:33: warning: 'std::ios_base::io_state' is deprecated
+  // CHECK-FIXES: using alias2 = std::ios_base::iostate;
+  alias2 e;
+
+  // Test pointers.
+  std::ios_base::io_state *f;
+  // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: 'std::ios_base::io_state' is deprecated
+  // CHECK-FIXES: std::ios_base::iostate *f;
+
+  // Test 'static' declarations.
+  static std::ios_base::io_state g;
+  // CHECK-MESSAGES: :[[@LINE-1]]:25: warning: 'std::ios_base::io_state' is deprecated
+  // CHECK-FIXES: static std::ios_base::iostate g;
+
+  // Test with cv-qualifiers.
+  const std::ios_base::io_state h(0);
+  // CHECK-MESSAGES: :[[@LINE-1]]:24: warning: 'std::ios_base::io_state' is deprecated
+  // CHECK-FIXES: const std::ios_base::iostate h(0);
+  volatile std::ios_base::io_state i;
+  // CHECK-MESSAGES: :[[@LINE-1]]:27: warning: 'std::ios_base::io_state' is deprecated
+  // CHECK-FIXES: volatile std::ios_base::iostate i;
+  const volatile std::ios_base::io_state j(0);
+  // CHECK-MESSAGES: :[[@LINE-1]]:33: warning: 'std::ios_base::io_state' is deprecated
+  // CHECK-FIXES: const volatile std::ios_base::iostate j(0);
+
+  // Test auto and initializer-list.
+  auto k = std::ios_base::io_state{};
+  // CHECK-MESSAGES: :[[@LINE-1]]:27: warning: 'std::ios_base::io_state' is deprecated
+  // CHECK-FIXES: auto k = std::ios_base::iostate{};
+
+  std::ios_base::io_state l{std::ios_base::io_state()};
+  // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: 'std::ios_base::io_state' is deprecated
+  // CHECK-MESSAGES: :[[@LINE-2]]:44: warning: 'std::ios_base::io_state' is deprecated
+  // CHECK-FIXES: std::ios_base::iostate l{std::ios_base::iostate()};
+
+  // Test temporaries.
+  std::ios_base::io_state();
+  // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: 'std::ios_base::io_state' is deprecated
+  // CHECK-FIXES: std::ios_base::iostate();
+
+  // Test inherited type usage
+  std::basic_ios<char>::io_state m;
+  // CHECK-MESSAGES: :[[@LINE-1]]:25: warning: 'std::ios_base::io_state' is deprecated
+  // CHECK-FIXES: std::basic_ios<char>::iostate m;
+
+  std::ios_base::streampos n;
+  // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: 'std::ios_base::streampos' is deprecated [modernize-deprecated-ios-base-aliases]
+
+  std::ios_base::streamoff o;
+  // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: 'std::ios_base::streamoff' is deprecated [modernize-deprecated-ios-base-aliases]
+}
+
+// Test without the nested name specifiers.
+void f_2() {
+  using namespace std;
+
+  ios_base::io_state a;
+  // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: 'std::ios_base::io_state' is deprecated
+  // CHECK-FIXES: ios_base::iostate a;
+}
+
+// Test messing-up with macros.
+void f_4() {
+#define MACRO_1 std::ios_base::io_state
+  // CHECK-MESSAGES: :[[@LINE-1]]:32: warning: 'std::ios_base::io_state' is deprecated
+  MACRO_1 a;
+
+#define MACRO_2 io_state
+  // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: 'std::ios_base::io_state' is deprecated
+  std::ios_base::MACRO_2 b;
+
+#define MACRO_3 std::ios_base
+  MACRO_3::io_state c;
+  // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: 'std::ios_base::io_state' is deprecated
+
+#define MACRO_4(type) type::io_state
+  // CHECK-MESSAGES: :[[@LINE-1]]:29: warning: 'std::ios_base::io_state' is deprecated
+  MACRO_4(std::ios_base) d;
+
+#undef MACRO_1
+#undef MACRO_2
+#undef MACRO_3
+#undef MACRO_4
+}
+
+// Test function return values (definition).
+std::ios_base::io_state f_5()
+// CHECK-MESSAGES: :[[@LINE-1]]:16: warning: 'std::ios_base::io_state' is deprecated
+// CHECK-FIXES: std::ios_base::iostate f_5()
+{
+  // Test constructor.
+  return std::ios_base::io_state(0);
+  // CHECK-MESSAGES: :[[@LINE-1]]:25: warning: 'std::ios_base::io_state' is deprecated
+  // CHECK-FIXES: return std::ios_base::iostate(0);
+}
+
+// Test that other aliases with same name aren't replaced
+struct my_ios_base {
+  typedef int io_state;
+};
+
+namespace ns_1 {
+struct my_ios_base2 {
+  typedef int io_state;
+};
+} // namespace ns_1
+
+void f_8() {
+  my_ios_base::io_state a;
+
+  ns_1::my_ios_base2::io_state b;
+}
+
+// Test templates
+template <typename X>
+void f_9() {
+  typename std::basic_ios<X>::io_state p;
+  // CHECK-MESSAGES: :[[@LINE-1]]:31: warning: 'std::ios_base::io_state' is deprecated
+  typename std::ios_base::io_state q;
+  // CHECK-MESSAGES: :[[@LINE-1]]:27: warning: 'std::ios_base::io_state' is deprecated
+  // CHECK-FIXES: typename std::ios_base::iostate q;
+}
+
+template <typename T>
+void f_10(T arg) {
+  T x(arg);
+}
+
+template <typename T>
+void f_11() {
+  typename T::io_state x{};
+  // CHECK-MESSAGES: :[[@LINE-1]]:15: warning: 'std::ios_base::io_state' is deprecated
+}
+
+template <typename T>
+struct D : std::ios_base {
+  io_state a;
+  // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: 'std::ios_base::io_state' is deprecated
+  // CHECK-FIXES: iostate a;
+
+  typename std::basic_ios<T>::io_state b;
+  // CHECK-MESSAGES: :[[@LINE-1]]:31: warning: 'std::ios_base::io_state' is deprecated
+};
+
+template <typename T>
+struct E {
+  T t;
+};
+
+void f_12() {
+  f_9<char>();
+
+  f_10<std::ios_base::io_state>(0);
+  // CHECK-MESSAGES: :[[@LINE-1]]:23: warning: 'std::ios_base::io_state' is deprecated
+  // CHECK-FIXES: f_10<std::ios_base::iostate>(0);
+
+  f_11<std::ios_base>();
+  D<char> d;
+
+  E<std::ios_base::io_state> e;
+  // CHECK-MESSAGES: :[[@LINE-1]]:20: warning: 'std::ios_base::io_state' is deprecated
+  // CHECK-FIXES: E<std::ios_base::iostate> e;
+}